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/* Handle parameterized types (templates) for GNU -*- C++ -*-.
Copyright (C) 1992-2019 Free Software Foundation, Inc.
Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
Rewritten by Jason Merrill (jason@cygnus.com).
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* Known bugs or deficiencies include:
all methods must be provided in header files; can't use a source
file that contains only the method templates and "just win". */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "cp-tree.h"
#include "timevar.h"
#include "stringpool.h"
#include "varasm.h"
#include "attribs.h"
#include "stor-layout.h"
#include "intl.h"
#include "c-family/c-objc.h"
#include "cp-objcp-common.h"
#include "toplev.h"
#include "tree-iterator.h"
#include "type-utils.h"
#include "gimplify.h"
#include "gcc-rich-location.h"
#include "selftest.h"
/* The type of functions taking a tree, and some additional data, and
returning an int. */
typedef int (*tree_fn_t) (tree, void*);
/* The PENDING_TEMPLATES is a TREE_LIST of templates whose
instantiations have been deferred, either because their definitions
were not yet available, or because we were putting off doing the work. */
struct GTY ((chain_next ("%h.next"))) pending_template
{
struct pending_template *next;
struct tinst_level *tinst;
};
static GTY(()) struct pending_template *pending_templates;
static GTY(()) struct pending_template *last_pending_template;
int processing_template_parmlist;
static int template_header_count;
static GTY(()) tree saved_trees;
static vec<int> inline_parm_levels;
static GTY(()) struct tinst_level *current_tinst_level;
static GTY(()) tree saved_access_scope;
/* Live only within one (recursive) call to tsubst_expr. We use
this to pass the statement expression node from the STMT_EXPR
to the EXPR_STMT that is its result. */
static tree cur_stmt_expr;
// -------------------------------------------------------------------------- //
// Local Specialization Stack
//
// Implementation of the RAII helper for creating new local
// specializations.
local_specialization_stack::local_specialization_stack (lss_policy policy)
: saved (local_specializations)
{
if (policy == lss_blank || !saved)
local_specializations = new hash_map<tree, tree>;
else
local_specializations = new hash_map<tree, tree>(*saved);
}
local_specialization_stack::~local_specialization_stack ()
{
delete local_specializations;
local_specializations = saved;
}
/* True if we've recursed into fn_type_unification too many times. */
static bool excessive_deduction_depth;
struct GTY((for_user)) spec_entry
{
tree tmpl;
tree args;
tree spec;
};
struct spec_hasher : ggc_ptr_hash<spec_entry>
{
static hashval_t hash (spec_entry *);
static bool equal (spec_entry *, spec_entry *);
};
static GTY (()) hash_table<spec_hasher> *decl_specializations;
static GTY (()) hash_table<spec_hasher> *type_specializations;
/* Contains canonical template parameter types. The vector is indexed by
the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
TREE_LIST, whose TREE_VALUEs contain the canonical template
parameters of various types and levels. */
static GTY(()) vec<tree, va_gc> *canonical_template_parms;
#define UNIFY_ALLOW_NONE 0
#define UNIFY_ALLOW_MORE_CV_QUAL 1
#define UNIFY_ALLOW_LESS_CV_QUAL 2
#define UNIFY_ALLOW_DERIVED 4
#define UNIFY_ALLOW_INTEGER 8
#define UNIFY_ALLOW_OUTER_LEVEL 16
#define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
#define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
enum template_base_result {
tbr_incomplete_type,
tbr_ambiguous_baseclass,
tbr_success
};
static void push_access_scope (tree);
static void pop_access_scope (tree);
static bool resolve_overloaded_unification (tree, tree, tree, tree,
unification_kind_t, int,
bool);
static int try_one_overload (tree, tree, tree, tree, tree,
unification_kind_t, int, bool, bool);
static int unify (tree, tree, tree, tree, int, bool);
static void add_pending_template (tree);
static tree reopen_tinst_level (struct tinst_level *);
static tree tsubst_initializer_list (tree, tree);
static tree get_partial_spec_bindings (tree, tree, tree);
static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
bool, bool);
static tree coerce_innermost_template_parms (tree, tree, tree, tsubst_flags_t,
bool, bool);
static void tsubst_enum (tree, tree, tree);
static tree add_to_template_args (tree, tree);
static tree add_outermost_template_args (tree, tree);
static bool check_instantiated_args (tree, tree, tsubst_flags_t);
static int check_non_deducible_conversion (tree, tree, int, int,
struct conversion **, bool);
static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
tree);
static int type_unification_real (tree, tree, tree, const tree *,
unsigned int, int, unification_kind_t,
vec<deferred_access_check, va_gc> **,
bool);
static void note_template_header (int);
static tree convert_nontype_argument_function (tree, tree, tsubst_flags_t);
static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
static tree convert_template_argument (tree, tree, tree,
tsubst_flags_t, int, tree);
static tree for_each_template_parm (tree, tree_fn_t, void*,
hash_set<tree> *, bool, tree_fn_t = NULL);
static tree expand_template_argument_pack (tree);
static tree build_template_parm_index (int, int, int, tree, tree);
static bool inline_needs_template_parms (tree, bool);
static void push_inline_template_parms_recursive (tree, int);
static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
static int mark_template_parm (tree, void *);
static int template_parm_this_level_p (tree, void *);
static tree tsubst_friend_function (tree, tree);
static tree tsubst_friend_class (tree, tree);
static int can_complete_type_without_circularity (tree);
static tree get_bindings (tree, tree, tree, bool);
static int template_decl_level (tree);
static int check_cv_quals_for_unify (int, tree, tree);
static void template_parm_level_and_index (tree, int*, int*);
static int unify_pack_expansion (tree, tree, tree,
tree, unification_kind_t, bool, bool);
static tree copy_template_args (tree);
static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
static tree most_specialized_partial_spec (tree, tsubst_flags_t);
static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
static tree tsubst_arg_types (tree, tree, tree, tsubst_flags_t, tree);
static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
static bool check_specialization_scope (void);
static tree process_partial_specialization (tree);
static void set_current_access_from_decl (tree);
static enum template_base_result get_template_base (tree, tree, tree, tree,
bool , tree *);
static tree try_class_unification (tree, tree, tree, tree, bool);
static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
tree, tree);
static bool template_template_parm_bindings_ok_p (tree, tree);
static void tsubst_default_arguments (tree, tsubst_flags_t);
static tree for_each_template_parm_r (tree *, int *, void *);
static tree copy_default_args_to_explicit_spec_1 (tree, tree);
static void copy_default_args_to_explicit_spec (tree);
static bool invalid_nontype_parm_type_p (tree, tsubst_flags_t);
static bool dependent_template_arg_p (tree);
static bool any_template_arguments_need_structural_equality_p (tree);
static bool dependent_type_p_r (tree);
static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
static tree tsubst_decl (tree, tree, tsubst_flags_t);
static void perform_typedefs_access_check (tree tmpl, tree targs);
static void append_type_to_template_for_access_check_1 (tree, tree, tree,
location_t);
static tree listify (tree);
static tree listify_autos (tree, tree);
static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
static tree instantiate_alias_template (tree, tree, tsubst_flags_t);
static bool complex_alias_template_p (const_tree tmpl);
static tree tsubst_attributes (tree, tree, tsubst_flags_t, tree);
static tree canonicalize_expr_argument (tree, tsubst_flags_t);
static tree make_argument_pack (tree);
static void register_parameter_specializations (tree, tree);
static tree enclosing_instantiation_of (tree tctx);
/* Make the current scope suitable for access checking when we are
processing T. T can be FUNCTION_DECL for instantiated function
template, VAR_DECL for static member variable, or TYPE_DECL for
alias template (needed by instantiate_decl). */
static void
push_access_scope (tree t)
{
gcc_assert (VAR_OR_FUNCTION_DECL_P (t)
|| TREE_CODE (t) == TYPE_DECL);
if (DECL_FRIEND_CONTEXT (t))
push_nested_class (DECL_FRIEND_CONTEXT (t));
else if (DECL_CLASS_SCOPE_P (t))
push_nested_class (DECL_CONTEXT (t));
else
push_to_top_level ();
if (TREE_CODE (t) == FUNCTION_DECL)
{
saved_access_scope = tree_cons
(NULL_TREE, current_function_decl, saved_access_scope);
current_function_decl = t;
}
}
/* Restore the scope set up by push_access_scope. T is the node we
are processing. */
static void
pop_access_scope (tree t)
{
if (TREE_CODE (t) == FUNCTION_DECL)
{
current_function_decl = TREE_VALUE (saved_access_scope);
saved_access_scope = TREE_CHAIN (saved_access_scope);
}
if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
pop_nested_class ();
else
pop_from_top_level ();
}
/* Do any processing required when DECL (a member template
declaration) is finished. Returns the TEMPLATE_DECL corresponding
to DECL, unless it is a specialization, in which case the DECL
itself is returned. */
tree
finish_member_template_decl (tree decl)
{
if (decl == error_mark_node)
return error_mark_node;
gcc_assert (DECL_P (decl));
if (TREE_CODE (decl) == TYPE_DECL)
{
tree type;
type = TREE_TYPE (decl);
if (type == error_mark_node)
return error_mark_node;
if (MAYBE_CLASS_TYPE_P (type)
&& CLASSTYPE_TEMPLATE_INFO (type)
&& !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
{
tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
check_member_template (tmpl);
return tmpl;
}
return NULL_TREE;
}
else if (TREE_CODE (decl) == FIELD_DECL)
error ("data member %qD cannot be a member template", decl);
else if (DECL_TEMPLATE_INFO (decl))
{
if (!DECL_TEMPLATE_SPECIALIZATION (decl))
{
check_member_template (DECL_TI_TEMPLATE (decl));
return DECL_TI_TEMPLATE (decl);
}
else
return decl;
}
else
error ("invalid member template declaration %qD", decl);
return error_mark_node;
}
/* Create a template info node. */
tree
build_template_info (tree template_decl, tree template_args)
{
tree result = make_node (TEMPLATE_INFO);
TI_TEMPLATE (result) = template_decl;
TI_ARGS (result) = template_args;
return result;
}
/* Return the template info node corresponding to T, whatever T is. */
tree
get_template_info (const_tree t)
{
tree tinfo = NULL_TREE;
if (!t || t == error_mark_node)
return NULL;
if (TREE_CODE (t) == NAMESPACE_DECL
|| TREE_CODE (t) == PARM_DECL)
return NULL;
if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
tinfo = DECL_TEMPLATE_INFO (t);
if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
t = TREE_TYPE (t);
if (OVERLOAD_TYPE_P (t))
tinfo = TYPE_TEMPLATE_INFO (t);
else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
return tinfo;
}
/* Returns the template nesting level of the indicated class TYPE.
For example, in:
template <class T>
struct A
{
template <class U>
struct B {};
};
A<T>::B<U> has depth two, while A<T> has depth one.
Both A<T>::B<int> and A<int>::B<U> have depth one, if
they are instantiations, not specializations.
This function is guaranteed to return 0 if passed NULL_TREE so
that, for example, `template_class_depth (current_class_type)' is
always safe. */
int
template_class_depth (tree type)
{
int depth;
for (depth = 0; type && TREE_CODE (type) != NAMESPACE_DECL; )
{
tree tinfo = get_template_info (type);
if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
&& uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
++depth;
if (DECL_P (type))
type = CP_DECL_CONTEXT (type);
else if (LAMBDA_TYPE_P (type))
type = LAMBDA_TYPE_EXTRA_SCOPE (type);
else
type = CP_TYPE_CONTEXT (type);
}
return depth;
}
/* Return TRUE if NODE instantiates a template that has arguments of
its own, be it directly a primary template or indirectly through a
partial specializations. */
static bool
instantiates_primary_template_p (tree node)
{
tree tinfo = get_template_info (node);
if (!tinfo)
return false;
tree tmpl = TI_TEMPLATE (tinfo);
if (PRIMARY_TEMPLATE_P (tmpl))
return true;
if (!DECL_TEMPLATE_SPECIALIZATION (tmpl))
return false;
/* So now we know we have a specialization, but it could be a full
or a partial specialization. To tell which, compare the depth of
its template arguments with those of its context. */
tree ctxt = DECL_CONTEXT (tmpl);
tree ctinfo = get_template_info (ctxt);
if (!ctinfo)
return true;
return (TMPL_ARGS_DEPTH (TI_ARGS (tinfo))
> TMPL_ARGS_DEPTH (TI_ARGS (ctinfo)));
}
/* Subroutine of maybe_begin_member_template_processing.
Returns true if processing DECL needs us to push template parms. */
static bool
inline_needs_template_parms (tree decl, bool nsdmi)
{
if (!decl || (!nsdmi && ! DECL_TEMPLATE_INFO (decl)))
return false;
return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
> (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
}
/* Subroutine of maybe_begin_member_template_processing.
Push the template parms in PARMS, starting from LEVELS steps into the
chain, and ending at the beginning, since template parms are listed
innermost first. */
static void
push_inline_template_parms_recursive (tree parmlist, int levels)
{
tree parms = TREE_VALUE (parmlist);
int i;
if (levels > 1)
push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
++processing_template_decl;
current_template_parms
= tree_cons (size_int (processing_template_decl),
parms, current_template_parms);
TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
NULL);
for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
{
tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
if (error_operand_p (parm))
continue;
gcc_assert (DECL_P (parm));
switch (TREE_CODE (parm))
{
case TYPE_DECL:
case TEMPLATE_DECL:
pushdecl (parm);
break;
case PARM_DECL:
/* Push the CONST_DECL. */
pushdecl (TEMPLATE_PARM_DECL (DECL_INITIAL (parm)));
break;
default:
gcc_unreachable ();
}
}
}
/* Restore the template parameter context for a member template, a
friend template defined in a class definition, or a non-template
member of template class. */
void
maybe_begin_member_template_processing (tree decl)
{
tree parms;
int levels = 0;
bool nsdmi = TREE_CODE (decl) == FIELD_DECL;
if (nsdmi)
{
tree ctx = DECL_CONTEXT (decl);
decl = (CLASSTYPE_TEMPLATE_INFO (ctx)
/* Disregard full specializations (c++/60999). */
&& uses_template_parms (ctx)
? CLASSTYPE_TI_TEMPLATE (ctx) : NULL_TREE);
}
if (inline_needs_template_parms (decl, nsdmi))
{
parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
if (DECL_TEMPLATE_SPECIALIZATION (decl))
{
--levels;
parms = TREE_CHAIN (parms);
}
push_inline_template_parms_recursive (parms, levels);
}
/* Remember how many levels of template parameters we pushed so that
we can pop them later. */
inline_parm_levels.safe_push (levels);
}
/* Undo the effects of maybe_begin_member_template_processing. */
void
maybe_end_member_template_processing (void)
{
int i;
int last;
if (inline_parm_levels.length () == 0)
return;
last = inline_parm_levels.pop ();
for (i = 0; i < last; ++i)
{
--processing_template_decl;
current_template_parms = TREE_CHAIN (current_template_parms);
poplevel (0, 0, 0);
}
}
/* Return a new template argument vector which contains all of ARGS,
but has as its innermost set of arguments the EXTRA_ARGS. */
static tree
add_to_template_args (tree args, tree extra_args)
{
tree new_args;
int extra_depth;
int i;
int j;
if (args == NULL_TREE || extra_args == error_mark_node)
return extra_args;
extra_depth = TMPL_ARGS_DEPTH (extra_args);
new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
for (j = 1; j <= extra_depth; ++j, ++i)
SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
return new_args;
}
/* Like add_to_template_args, but only the outermost ARGS are added to
the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
(EXTRA_ARGS) levels are added. This function is used to combine
the template arguments from a partial instantiation with the
template arguments used to attain the full instantiation from the
partial instantiation. */
static tree
add_outermost_template_args (tree args, tree extra_args)
{
tree new_args;
/* If there are more levels of EXTRA_ARGS than there are ARGS,
something very fishy is going on. */
gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
/* If *all* the new arguments will be the EXTRA_ARGS, just return
them. */
if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
return extra_args;
/* For the moment, we make ARGS look like it contains fewer levels. */
TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
new_args = add_to_template_args (args, extra_args);
/* Now, we restore ARGS to its full dimensions. */
TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
return new_args;
}
/* Return the N levels of innermost template arguments from the ARGS. */
tree
get_innermost_template_args (tree args, int n)
{
tree new_args;
int extra_levels;
int i;
gcc_assert (n >= 0);
/* If N is 1, just return the innermost set of template arguments. */
if (n == 1)
return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
/* If we're not removing anything, just return the arguments we were
given. */
extra_levels = TMPL_ARGS_DEPTH (args) - n;
gcc_assert (extra_levels >= 0);
if (extra_levels == 0)
return args;
/* Make a new set of arguments, not containing the outer arguments. */
new_args = make_tree_vec (n);
for (i = 1; i <= n; ++i)
SET_TMPL_ARGS_LEVEL (new_args, i,
TMPL_ARGS_LEVEL (args, i + extra_levels));
return new_args;
}
/* The inverse of get_innermost_template_args: Return all but the innermost
EXTRA_LEVELS levels of template arguments from the ARGS. */
static tree
strip_innermost_template_args (tree args, int extra_levels)
{
tree new_args;
int n = TMPL_ARGS_DEPTH (args) - extra_levels;
int i;
gcc_assert (n >= 0);
/* If N is 1, just return the outermost set of template arguments. */
if (n == 1)
return TMPL_ARGS_LEVEL (args, 1);
/* If we're not removing anything, just return the arguments we were
given. */
gcc_assert (extra_levels >= 0);
if (extra_levels == 0)
return args;
/* Make a new set of arguments, not containing the inner arguments. */
new_args = make_tree_vec (n);
for (i = 1; i <= n; ++i)
SET_TMPL_ARGS_LEVEL (new_args, i,
TMPL_ARGS_LEVEL (args, i));
return new_args;
}
/* We've got a template header coming up; push to a new level for storing
the parms. */
void
begin_template_parm_list (void)
{
/* We use a non-tag-transparent scope here, which causes pushtag to
put tags in this scope, rather than in the enclosing class or
namespace scope. This is the right thing, since we want
TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
global template class, push_template_decl handles putting the
TEMPLATE_DECL into top-level scope. For a nested template class,
e.g.:
template <class T> struct S1 {
template <class T> struct S2 {};
};
pushtag contains special code to insert the TEMPLATE_DECL for S2
at the right scope. */
begin_scope (sk_template_parms, NULL);
++processing_template_decl;
++processing_template_parmlist;
note_template_header (0);
/* Add a dummy parameter level while we process the parameter list. */
current_template_parms
= tree_cons (size_int (processing_template_decl),
make_tree_vec (0),
current_template_parms);
}
/* This routine is called when a specialization is declared. If it is
invalid to declare a specialization here, an error is reported and
false is returned, otherwise this routine will return true. */
static bool
check_specialization_scope (void)
{
tree scope = current_scope ();
/* [temp.expl.spec]
An explicit specialization shall be declared in the namespace of
which the template is a member, or, for member templates, in the
namespace of which the enclosing class or enclosing class
template is a member. An explicit specialization of a member
function, member class or static data member of a class template
shall be declared in the namespace of which the class template
is a member. */
if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
{
error ("explicit specialization in non-namespace scope %qD", scope);
return false;
}
/* [temp.expl.spec]
In an explicit specialization declaration for a member of a class
template or a member template that appears in namespace scope,
the member template and some of its enclosing class templates may
remain unspecialized, except that the declaration shall not
explicitly specialize a class member template if its enclosing
class templates are not explicitly specialized as well. */
if (current_template_parms)
{
error ("enclosing class templates are not explicitly specialized");
return false;
}
return true;
}
/* We've just seen template <>. */
bool
begin_specialization (void)
{
begin_scope (sk_template_spec, NULL);
note_template_header (1);
return check_specialization_scope ();
}
/* Called at then end of processing a declaration preceded by
template<>. */
void
end_specialization (void)
{
finish_scope ();
reset_specialization ();
}
/* Any template <>'s that we have seen thus far are not referring to a
function specialization. */
void
reset_specialization (void)
{
processing_specialization = 0;
template_header_count = 0;
}
/* We've just seen a template header. If SPECIALIZATION is nonzero,
it was of the form template <>. */
static void
note_template_header (int specialization)
{
processing_specialization = specialization;
template_header_count++;
}
/* We're beginning an explicit instantiation. */
void
begin_explicit_instantiation (void)
{
gcc_assert (!processing_explicit_instantiation);
processing_explicit_instantiation = true;
}
void
end_explicit_instantiation (void)
{
gcc_assert (processing_explicit_instantiation);
processing_explicit_instantiation = false;
}
/* An explicit specialization or partial specialization of TMPL is being
declared. Check that the namespace in which the specialization is
occurring is permissible. Returns false iff it is invalid to
specialize TMPL in the current namespace. */
static bool
check_specialization_namespace (tree tmpl)
{
tree tpl_ns = decl_namespace_context (tmpl);
/* [tmpl.expl.spec]
An explicit specialization shall be declared in a namespace enclosing the
specialized template. An explicit specialization whose declarator-id is
not qualified shall be declared in the nearest enclosing namespace of the
template, or, if the namespace is inline (7.3.1), any namespace from its
enclosing namespace set. */
if (current_scope() != DECL_CONTEXT (tmpl)
&& !at_namespace_scope_p ())
{
error ("specialization of %qD must appear at namespace scope", tmpl);
return false;
}
if (is_nested_namespace (current_namespace, tpl_ns, cxx_dialect < cxx11))
/* Same or enclosing namespace. */
return true;
else
{
auto_diagnostic_group d;
if (permerror (input_location,
"specialization of %qD in different namespace", tmpl))
inform (DECL_SOURCE_LOCATION (tmpl),
" from definition of %q#D", tmpl);
return false;
}
}
/* SPEC is an explicit instantiation. Check that it is valid to
perform this explicit instantiation in the current namespace. */
static void
check_explicit_instantiation_namespace (tree spec)
{
tree ns;
/* DR 275: An explicit instantiation shall appear in an enclosing
namespace of its template. */
ns = decl_namespace_context (spec);
if (!is_nested_namespace (current_namespace, ns))
permerror (input_location, "explicit instantiation of %qD in namespace %qD "
"(which does not enclose namespace %qD)",
spec, current_namespace, ns);
}
// Returns the type of a template specialization only if that
// specialization needs to be defined. Otherwise (e.g., if the type has
// already been defined), the function returns NULL_TREE.
static tree
maybe_new_partial_specialization (tree type)
{
// An implicit instantiation of an incomplete type implies
// the definition of a new class template.
//
// template<typename T>
// struct S;
//
// template<typename T>
// struct S<T*>;
//
// Here, S<T*> is an implicit instantiation of S whose type
// is incomplete.
if (CLASSTYPE_IMPLICIT_INSTANTIATION (type) && !COMPLETE_TYPE_P (type))
return type;
// It can also be the case that TYPE is a completed specialization.
// Continuing the previous example, suppose we also declare:
//
// template<typename T>
// requires Integral<T>
// struct S<T*>;
//
// Here, S<T*> refers to the specialization S<T*> defined
// above. However, we need to differentiate definitions because
// we intend to define a new partial specialization. In this case,
// we rely on the fact that the constraints are different for
// this declaration than that above.
//
// Note that we also get here for injected class names and
// late-parsed template definitions. We must ensure that we
// do not create new type declarations for those cases.
if (flag_concepts && CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
{
tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
tree args = CLASSTYPE_TI_ARGS (type);
// If there are no template parameters, this cannot be a new
// partial template specializtion?
if (!current_template_parms)
return NULL_TREE;
// The injected-class-name is not a new partial specialization.
if (DECL_SELF_REFERENCE_P (TYPE_NAME (type)))
return NULL_TREE;
// If the constraints are not the same as those of the primary
// then, we can probably create a new specialization.
tree type_constr = current_template_constraints ();
if (type == TREE_TYPE (tmpl))
{
tree main_constr = get_constraints (tmpl);
if (equivalent_constraints (type_constr, main_constr))
return NULL_TREE;
}
// Also, if there's a pre-existing specialization with matching
// constraints, then this also isn't new.
tree specs = DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
while (specs)
{
tree spec_tmpl = TREE_VALUE (specs);
tree spec_args = TREE_PURPOSE (specs);
tree spec_constr = get_constraints (spec_tmpl);
if (comp_template_args (args, spec_args)
&& equivalent_constraints (type_constr, spec_constr))
return NULL_TREE;
specs = TREE_CHAIN (specs);
}
// Create a new type node (and corresponding type decl)
// for the newly declared specialization.
tree t = make_class_type (TREE_CODE (type));
CLASSTYPE_DECLARED_CLASS (t) = CLASSTYPE_DECLARED_CLASS (type);
SET_TYPE_TEMPLATE_INFO (t, build_template_info (tmpl, args));
/* We only need a separate type node for storing the definition of this
partial specialization; uses of S<T*> are unconstrained, so all are
equivalent. So keep TYPE_CANONICAL the same. */
TYPE_CANONICAL (t) = TYPE_CANONICAL (type);
// Build the corresponding type decl.
tree d = create_implicit_typedef (DECL_NAME (tmpl), t);
DECL_CONTEXT (d) = TYPE_CONTEXT (t);
DECL_SOURCE_LOCATION (d) = input_location;
return t;
}
return NULL_TREE;
}
/* The TYPE is being declared. If it is a template type, that means it
is a partial specialization. Do appropriate error-checking. */
tree
maybe_process_partial_specialization (tree type)
{
tree context;
if (type == error_mark_node)
return error_mark_node;
/* A lambda that appears in specialization context is not itself a
specialization. */
if (CLASS_TYPE_P (type) && CLASSTYPE_LAMBDA_EXPR (type))
return type;
/* An injected-class-name is not a specialization. */
if (DECL_SELF_REFERENCE_P (TYPE_NAME (type)))
return type;
if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
{
error ("name of class shadows template template parameter %qD",
TYPE_NAME (type));
return error_mark_node;
}
context = TYPE_CONTEXT (type);
if (TYPE_ALIAS_P (type))
{
tree tinfo = TYPE_ALIAS_TEMPLATE_INFO (type);
if (tinfo && DECL_ALIAS_TEMPLATE_P (TI_TEMPLATE (tinfo)))
error ("specialization of alias template %qD",
TI_TEMPLATE (tinfo));
else
error ("explicit specialization of non-template %qT", type);
return error_mark_node;
}
else if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
{
/* This is for ordinary explicit specialization and partial
specialization of a template class such as:
template <> class C<int>;
or:
template <class T> class C<T*>;
Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
if (tree t = maybe_new_partial_specialization (type))
{
if (!check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (t))
&& !at_namespace_scope_p ())
return error_mark_node;
SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (t);
DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (t)) = input_location;
if (processing_template_decl)
{
tree decl = push_template_decl (TYPE_MAIN_DECL (t));
if (decl == error_mark_node)
return error_mark_node;
return TREE_TYPE (decl);
}
}
else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
error ("specialization of %qT after instantiation", type);
else if (errorcount && !processing_specialization
&& CLASSTYPE_TEMPLATE_SPECIALIZATION (type)
&& !uses_template_parms (CLASSTYPE_TI_ARGS (type)))
/* Trying to define a specialization either without a template<> header
or in an inappropriate place. We've already given an error, so just
bail now so we don't actually define the specialization. */
return error_mark_node;
}
else if (CLASS_TYPE_P (type)
&& !CLASSTYPE_USE_TEMPLATE (type)
&& CLASSTYPE_TEMPLATE_INFO (type)
&& context && CLASS_TYPE_P (context)
&& CLASSTYPE_TEMPLATE_INFO (context))
{
/* This is for an explicit specialization of member class
template according to [temp.expl.spec/18]:
template <> template <class U> class C<int>::D;
The context `C<int>' must be an implicit instantiation.
Otherwise this is just a member class template declared
earlier like:
template <> class C<int> { template <class U> class D; };
template <> template <class U> class C<int>::D;
In the first case, `C<int>::D' is a specialization of `C<T>::D'
while in the second case, `C<int>::D' is a primary template
and `C<T>::D' may not exist. */
if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
&& !COMPLETE_TYPE_P (type))
{
tree t;
tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
if (current_namespace
!= decl_namespace_context (tmpl))
{
permerror (input_location,
"specializing %q#T in different namespace", type);
permerror (DECL_SOURCE_LOCATION (tmpl),
" from definition of %q#D", tmpl);
}
/* Check for invalid specialization after instantiation:
template <> template <> class C<int>::D<int>;
template <> template <class U> class C<int>::D; */
for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
t; t = TREE_CHAIN (t))
{
tree inst = TREE_VALUE (t);
if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst)
|| !COMPLETE_OR_OPEN_TYPE_P (inst))
{
/* We already have a full specialization of this partial
instantiation, or a full specialization has been
looked up but not instantiated. Reassign it to the
new member specialization template. */
spec_entry elt;
spec_entry *entry;
elt.tmpl = most_general_template (tmpl);
elt.args = CLASSTYPE_TI_ARGS (inst);
elt.spec = inst;
type_specializations->remove_elt (&elt);
elt.tmpl = tmpl;
CLASSTYPE_TI_ARGS (inst)
= elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
spec_entry **slot
= type_specializations->find_slot (&elt, INSERT);
entry = ggc_alloc<spec_entry> ();
*entry = elt;
*slot = entry;
}
else
/* But if we've had an implicit instantiation, that's a
problem ([temp.expl.spec]/6). */
error ("specialization %qT after instantiation %qT",
type, inst);
}
/* Mark TYPE as a specialization. And as a result, we only
have one level of template argument for the innermost
class template. */
SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)) = input_location;
CLASSTYPE_TI_ARGS (type)
= INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
}
}
else if (processing_specialization)
{
/* Someday C++0x may allow for enum template specialization. */
if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
&& CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
pedwarn (input_location, OPT_Wpedantic, "template specialization "
"of %qD not allowed by ISO C++", type);
else
{
error ("explicit specialization of non-template %qT", type);
return error_mark_node;
}
}
return type;
}
/* Returns nonzero if we can optimize the retrieval of specializations
for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
static inline bool
optimize_specialization_lookup_p (tree tmpl)
{
return (DECL_FUNCTION_TEMPLATE_P (tmpl)
&& DECL_CLASS_SCOPE_P (tmpl)
/* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
parameter. */
&& CLASS_TYPE_P (DECL_CONTEXT (tmpl))
/* The optimized lookup depends on the fact that the
template arguments for the member function template apply
purely to the containing class, which is not true if the
containing class is an explicit or partial
specialization. */
&& !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
&& !DECL_MEMBER_TEMPLATE_P (tmpl)
&& !DECL_CONV_FN_P (tmpl)
/* It is possible to have a template that is not a member
template and is not a member of a template class:
template <typename T>
struct S { friend A::f(); };
Here, the friend function is a template, but the context does
not have template information. The optimized lookup relies
on having ARGS be the template arguments for both the class
and the function template. */
&& !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
}
/* Make sure ARGS doesn't use any inappropriate typedefs; we should have
gone through coerce_template_parms by now. */
static void
verify_unstripped_args_1 (tree inner)
{
for (int i = 0; i < TREE_VEC_LENGTH (inner); ++i)
{
tree arg = TREE_VEC_ELT (inner, i);
if (TREE_CODE (arg) == TEMPLATE_DECL)
/* OK */;
else if (TYPE_P (arg))
gcc_assert (strip_typedefs (arg, NULL) == arg);
else if (ARGUMENT_PACK_P (arg))
verify_unstripped_args_1 (ARGUMENT_PACK_ARGS (arg));
else if (strip_typedefs (TREE_TYPE (arg), NULL) != TREE_TYPE (arg))
/* Allow typedefs on the type of a non-type argument, since a
parameter can have them. */;
else
gcc_assert (strip_typedefs_expr (arg, NULL) == arg);
}
}
static void
verify_unstripped_args (tree args)
{
++processing_template_decl;
if (!any_dependent_template_arguments_p (args))
verify_unstripped_args_1 (INNERMOST_TEMPLATE_ARGS (args));
--processing_template_decl;
}
/* Retrieve the specialization (in the sense of [temp.spec] - a
specialization is either an instantiation or an explicit
specialization) of TMPL for the given template ARGS. If there is
no such specialization, return NULL_TREE. The ARGS are a vector of
arguments, or a vector of vectors of arguments, in the case of
templates with more than one level of parameters.
If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
then we search for a partial specialization matching ARGS. This
parameter is ignored if TMPL is not a class template.
We can also look up a FIELD_DECL, if it is a lambda capture pack; the
result is a NONTYPE_ARGUMENT_PACK. */
static tree
retrieve_specialization (tree tmpl, tree args, hashval_t hash)
{
if (tmpl == NULL_TREE)
return NULL_TREE;
if (args == error_mark_node)
return NULL_TREE;
gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL
|| TREE_CODE (tmpl) == FIELD_DECL);
/* There should be as many levels of arguments as there are
levels of parameters. */
gcc_assert (TMPL_ARGS_DEPTH (args)
== (TREE_CODE (tmpl) == TEMPLATE_DECL
? TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl))
: template_class_depth (DECL_CONTEXT (tmpl))));
if (flag_checking)
verify_unstripped_args (args);
/* Lambda functions in templates aren't instantiated normally, but through
tsubst_lambda_expr. */
if (lambda_fn_in_template_p (tmpl))
return NULL_TREE;
if (optimize_specialization_lookup_p (tmpl))
{
/* The template arguments actually apply to the containing
class. Find the class specialization with those
arguments. */
tree class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
tree class_specialization
= retrieve_specialization (class_template, args, 0);
if (!class_specialization)
return NULL_TREE;
/* Find the instance of TMPL. */
tree fns = get_class_binding (class_specialization, DECL_NAME (tmpl));
for (ovl_iterator iter (fns); iter; ++iter)
{
tree fn = *iter;
if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
/* using-declarations can add base methods to the method vec,
and we don't want those here. */
&& DECL_CONTEXT (fn) == class_specialization)
return fn;
}
return NULL_TREE;
}
else
{
spec_entry *found;
spec_entry elt;
hash_table<spec_hasher> *specializations;
elt.tmpl = tmpl;
elt.args = args;
elt.spec = NULL_TREE;
if (DECL_CLASS_TEMPLATE_P (tmpl))
specializations = type_specializations;
else
specializations = decl_specializations;
if (hash == 0)
hash = spec_hasher::hash (&elt);
found = specializations->find_with_hash (&elt, hash);
if (found)
return found->spec;
}
return NULL_TREE;
}
/* Like retrieve_specialization, but for local declarations. */
tree
retrieve_local_specialization (tree tmpl)
{
if (local_specializations == NULL)
return NULL_TREE;
tree *slot = local_specializations->get (tmpl);
return slot ? *slot : NULL_TREE;
}
/* Returns nonzero iff DECL is a specialization of TMPL. */
int
is_specialization_of (tree decl, tree tmpl)
{
tree t;
if (TREE_CODE (decl) == FUNCTION_DECL)
{
for (t = decl;
t != NULL_TREE;
t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
if (t == tmpl)
return 1;
}
else
{
gcc_assert (TREE_CODE (decl) == TYPE_DECL);
for (t = TREE_TYPE (decl);
t != NULL_TREE;
t = CLASSTYPE_USE_TEMPLATE (t)
? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
return 1;
}
return 0;
}
/* Returns nonzero iff DECL is a specialization of friend declaration
FRIEND_DECL according to [temp.friend]. */
bool
is_specialization_of_friend (tree decl, tree friend_decl)
{
bool need_template = true;
int template_depth;
gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
|| TREE_CODE (decl) == TYPE_DECL);
/* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
of a template class, we want to check if DECL is a specialization
if this. */
if (TREE_CODE (friend_decl) == FUNCTION_DECL
&& DECL_TEMPLATE_INFO (friend_decl)
&& !DECL_USE_TEMPLATE (friend_decl))
{
/* We want a TEMPLATE_DECL for `is_specialization_of'. */
friend_decl = DECL_TI_TEMPLATE (friend_decl);
need_template = false;
}
else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
&& !PRIMARY_TEMPLATE_P (friend_decl))
need_template = false;
/* There is nothing to do if this is not a template friend. */
if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
return false;
if (is_specialization_of (decl, friend_decl))
return true;
/* [temp.friend/6]
A member of a class template may be declared to be a friend of a
non-template class. In this case, the corresponding member of
every specialization of the class template is a friend of the
class granting friendship.
For example, given a template friend declaration
template <class T> friend void A<T>::f();
the member function below is considered a friend
template <> struct A<int> {
void f();
};
For this type of template friend, TEMPLATE_DEPTH below will be
nonzero. To determine if DECL is a friend of FRIEND, we first
check if the enclosing class is a specialization of another. */
template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
if (template_depth
&& DECL_CLASS_SCOPE_P (decl)
&& is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
{
/* Next, we check the members themselves. In order to handle
a few tricky cases, such as when FRIEND_DECL's are
template <class T> friend void A<T>::g(T t);
template <class T> template <T t> friend void A<T>::h();
and DECL's are
void A<int>::g(int);
template <int> void A<int>::h();
we need to figure out ARGS, the template arguments from
the context of DECL. This is required for template substitution
of `T' in the function parameter of `g' and template parameter
of `h' in the above examples. Here ARGS corresponds to `int'. */
tree context = DECL_CONTEXT (decl);
tree args = NULL_TREE;
int current_depth = 0;
while (current_depth < template_depth)
{
if (CLASSTYPE_TEMPLATE_INFO (context))
{
if (current_depth == 0)
args = TYPE_TI_ARGS (context);
else
args = add_to_template_args (TYPE_TI_ARGS (context), args);
current_depth++;
}
context = TYPE_CONTEXT (context);
}
if (TREE_CODE (decl) == FUNCTION_DECL)
{
bool is_template;
tree friend_type;
tree decl_type;
tree friend_args_type;
tree decl_args_type;
/* Make sure that both DECL and FRIEND_DECL are templates or
non-templates. */
is_template = DECL_TEMPLATE_INFO (decl)
&& PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
if (need_template ^ is_template)
return false;
else if (is_template)
{
/* If both are templates, check template parameter list. */
tree friend_parms
= tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
args, tf_none);
if (!comp_template_parms
(DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
friend_parms))
return false;
decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
}
else
decl_type = TREE_TYPE (decl);
friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
tf_none, NULL_TREE);
if (friend_type == error_mark_node)
return false;
/* Check if return types match. */
if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
return false;
/* Check if function parameter types match, ignoring the
`this' parameter. */
friend_args_type = TYPE_ARG_TYPES (friend_type);
decl_args_type = TYPE_ARG_TYPES (decl_type);
if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
friend_args_type = TREE_CHAIN (friend_args_type);
if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
decl_args_type = TREE_CHAIN (decl_args_type);
return compparms (decl_args_type, friend_args_type);
}
else
{
/* DECL is a TYPE_DECL */
bool is_template;
tree decl_type = TREE_TYPE (decl);
/* Make sure that both DECL and FRIEND_DECL are templates or
non-templates. */
is_template
= CLASSTYPE_TEMPLATE_INFO (decl_type)
&& PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
if (need_template ^ is_template)
return false;
else if (is_template)
{
tree friend_parms;
/* If both are templates, check the name of the two
TEMPLATE_DECL's first because is_friend didn't. */
if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
!= DECL_NAME (friend_decl))
return false;
/* Now check template parameter list. */
friend_parms
= tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
args, tf_none);
return comp_template_parms
(DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
friend_parms);
}
else
return (DECL_NAME (decl)
== DECL_NAME (friend_decl));
}
}
return false;
}
/* Register the specialization SPEC as a specialization of TMPL with
the indicated ARGS. IS_FRIEND indicates whether the specialization
is actually just a friend declaration. ATTRLIST is the list of
attributes that the specialization is declared with or NULL when
it isn't. Returns SPEC, or an equivalent prior declaration, if
available.
We also store instantiations of field packs in the hash table, even
though they are not themselves templates, to make lookup easier. */
static tree
register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
hashval_t hash)
{
tree fn;
spec_entry **slot = NULL;
spec_entry elt;
gcc_assert ((TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec))
|| (TREE_CODE (tmpl) == FIELD_DECL
&& TREE_CODE (spec) == NONTYPE_ARGUMENT_PACK));
if (TREE_CODE (spec) == FUNCTION_DECL
&& uses_template_parms (DECL_TI_ARGS (spec)))
/* This is the FUNCTION_DECL for a partial instantiation. Don't
register it; we want the corresponding TEMPLATE_DECL instead.
We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
the more obvious `uses_template_parms (spec)' to avoid problems
with default function arguments. In particular, given
something like this:
template <class T> void f(T t1, T t = T())
the default argument expression is not substituted for in an
instantiation unless and until it is actually needed. */
return spec;
if (optimize_specialization_lookup_p (tmpl))
/* We don't put these specializations in the hash table, but we might
want to give an error about a mismatch. */
fn = retrieve_specialization (tmpl, args, 0);
else
{
elt.tmpl = tmpl;
elt.args = args;
elt.spec = spec;
if (hash == 0)
hash = spec_hasher::hash (&elt);
slot =
decl_specializations->find_slot_with_hash (&elt, hash, INSERT);
if (*slot)
fn = ((spec_entry *) *slot)->spec;
else
fn = NULL_TREE;
}
/* We can sometimes try to re-register a specialization that we've
already got. In particular, regenerate_decl_from_template calls
duplicate_decls which will update the specialization list. But,
we'll still get called again here anyhow. It's more convenient
to simply allow this than to try to prevent it. */
if (fn == spec)
return spec;
else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
{
if (DECL_TEMPLATE_INSTANTIATION (fn))
{
if (DECL_ODR_USED (fn)
|| DECL_EXPLICIT_INSTANTIATION (fn))
{
error ("specialization of %qD after instantiation",
fn);
return error_mark_node;
}
else
{
tree clone;
/* This situation should occur only if the first
specialization is an implicit instantiation, the
second is an explicit specialization, and the
implicit instantiation has not yet been used. That
situation can occur if we have implicitly
instantiated a member function and then specialized
it later.
We can also wind up here if a friend declaration that
looked like an instantiation turns out to be a
specialization:
template <class T> void foo(T);
class S { friend void foo<>(int) };
template <> void foo(int);
We transform the existing DECL in place so that any
pointers to it become pointers to the updated
declaration.
If there was a definition for the template, but not
for the specialization, we want this to look as if
there were no definition, and vice versa. */
DECL_INITIAL (fn) = NULL_TREE;
duplicate_decls (spec, fn, is_friend);
/* The call to duplicate_decls will have applied
[temp.expl.spec]:
An explicit specialization of a function template
is inline only if it is explicitly declared to be,
and independently of whether its function template
is.
to the primary function; now copy the inline bits to
the various clones. */
FOR_EACH_CLONE (clone, fn)
{
DECL_DECLARED_INLINE_P (clone)
= DECL_DECLARED_INLINE_P (fn);
DECL_SOURCE_LOCATION (clone)
= DECL_SOURCE_LOCATION (fn);
DECL_DELETED_FN (clone)
= DECL_DELETED_FN (fn);
}
check_specialization_namespace (tmpl);
return fn;
}
}
else if (DECL_TEMPLATE_SPECIALIZATION (fn))
{
tree dd = duplicate_decls (spec, fn, is_friend);
if (dd == error_mark_node)
/* We've already complained in duplicate_decls. */
return error_mark_node;
if (dd == NULL_TREE && DECL_INITIAL (spec))
/* Dup decl failed, but this is a new definition. Set the
line number so any errors match this new
definition. */
DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
return fn;
}
}
else if (fn)
return duplicate_decls (spec, fn, is_friend);
/* A specialization must be declared in the same namespace as the
template it is specializing. */
if (DECL_P (spec) && DECL_TEMPLATE_SPECIALIZATION (spec)
&& !check_specialization_namespace (tmpl))
DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
{
spec_entry *entry = ggc_alloc<spec_entry> ();
gcc_assert (tmpl && args && spec);
*entry = elt;
*slot = entry;
if ((TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
&& PRIMARY_TEMPLATE_P (tmpl)
&& DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
|| variable_template_p (tmpl))
/* If TMPL is a forward declaration of a template function, keep a list
of all specializations in case we need to reassign them to a friend
template later in tsubst_friend_function.
Also keep a list of all variable template instantiations so that
process_partial_specialization can check whether a later partial
specialization would have used it. */
DECL_TEMPLATE_INSTANTIATIONS (tmpl)
= tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
}
return spec;
}
/* Returns true iff two spec_entry nodes are equivalent. */
int comparing_specializations;
bool
spec_hasher::equal (spec_entry *e1, spec_entry *e2)
{
int equal;
++comparing_specializations;
equal = (e1->tmpl == e2->tmpl
&& comp_template_args (e1->args, e2->args));
if (equal && flag_concepts
/* tmpl could be a FIELD_DECL for a capture pack. */
&& TREE_CODE (e1->tmpl) == TEMPLATE_DECL
&& VAR_P (DECL_TEMPLATE_RESULT (e1->tmpl))
&& uses_template_parms (e1->args))
{
/* Partial specializations of a variable template can be distinguished by
constraints. */
tree c1 = e1->spec ? get_constraints (e1->spec) : NULL_TREE;
tree c2 = e2->spec ? get_constraints (e2->spec) : NULL_TREE;
equal = equivalent_constraints (c1, c2);
}
--comparing_specializations;
return equal;
}
/* Returns a hash for a template TMPL and template arguments ARGS. */
static hashval_t
hash_tmpl_and_args (tree tmpl, tree args)
{
hashval_t val = iterative_hash_object (DECL_UID (tmpl), 0);
return iterative_hash_template_arg (args, val);
}
/* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
ignoring SPEC. */
hashval_t
spec_hasher::hash (spec_entry *e)
{
return hash_tmpl_and_args (e->tmpl, e->args);
}
/* Recursively calculate a hash value for a template argument ARG, for use
in the hash tables of template specializations. */
hashval_t
iterative_hash_template_arg (tree arg, hashval_t val)
{
unsigned HOST_WIDE_INT i;
enum tree_code code;
char tclass;
if (arg == NULL_TREE)
return iterative_hash_object (arg, val);
if (!TYPE_P (arg))
STRIP_NOPS (arg);
if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
gcc_unreachable ();
code = TREE_CODE (arg);
tclass = TREE_CODE_CLASS (code);
val = iterative_hash_object (code, val);
switch (code)
{
case ERROR_MARK:
return val;
case IDENTIFIER_NODE:
return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
case TREE_VEC:
{
int i, len = TREE_VEC_LENGTH (arg);
for (i = 0; i < len; ++i)
val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
return val;
}
case TYPE_PACK_EXPANSION:
case EXPR_PACK_EXPANSION:
val = iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
return iterative_hash_template_arg (PACK_EXPANSION_EXTRA_ARGS (arg), val);
case TYPE_ARGUMENT_PACK:
case NONTYPE_ARGUMENT_PACK:
return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
case TREE_LIST:
for (; arg; arg = TREE_CHAIN (arg))
val = iterative_hash_template_arg (TREE_VALUE (arg), val);
return val;
case OVERLOAD:
for (lkp_iterator iter (arg); iter; ++iter)
val = iterative_hash_template_arg (*iter, val);
return val;
case CONSTRUCTOR:
{
tree field, value;
iterative_hash_template_arg (TREE_TYPE (arg), val);
FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
{
val = iterative_hash_template_arg (field, val);
val = iterative_hash_template_arg (value, val);
}
return val;
}
case PARM_DECL:
if (!DECL_ARTIFICIAL (arg))
{
val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
}
return iterative_hash_template_arg (TREE_TYPE (arg), val);
case TARGET_EXPR:
return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
case PTRMEM_CST:
val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
case TEMPLATE_PARM_INDEX:
val = iterative_hash_template_arg
(TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
case TRAIT_EXPR:
val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
case BASELINK:
val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
val);
return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
val);
case MODOP_EXPR:
val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
code = TREE_CODE (TREE_OPERAND (arg, 1));
val = iterative_hash_object (code, val);
return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
case LAMBDA_EXPR:
/* [temp.over.link] Two lambda-expressions are never considered
equivalent.
So just hash the closure type. */
return iterative_hash_template_arg (TREE_TYPE (arg), val);
case CAST_EXPR:
case IMPLICIT_CONV_EXPR:
case STATIC_CAST_EXPR:
case REINTERPRET_CAST_EXPR:
case CONST_CAST_EXPR:
case DYNAMIC_CAST_EXPR:
case NEW_EXPR:
val = iterative_hash_template_arg (TREE_TYPE (arg), val);
/* Now hash operands as usual. */
break;
case CALL_EXPR:
{
tree fn = CALL_EXPR_FN (arg);
if (tree name = dependent_name (fn))
{
if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
val = iterative_hash_template_arg (TREE_OPERAND (fn, 1), val);
fn = name;
}
val = iterative_hash_template_arg (fn, val);
call_expr_arg_iterator ai;
for (tree x = first_call_expr_arg (arg, &ai); x;
x = next_call_expr_arg (&ai))
val = iterative_hash_template_arg (x, val);
return val;
}
default:
break;
}
switch (tclass)
{
case tcc_type:
if (alias_template_specialization_p (arg))
{
// We want an alias specialization that survived strip_typedefs
// to hash differently from its TYPE_CANONICAL, to avoid hash
// collisions that compare as different in template_args_equal.
// These could be dependent specializations that strip_typedefs
// left alone, or untouched specializations because
// coerce_template_parms returns the unconverted template
// arguments if it sees incomplete argument packs.
tree ti = TYPE_ALIAS_TEMPLATE_INFO (arg);
return hash_tmpl_and_args (TI_TEMPLATE (ti), TI_ARGS (ti));
}
if (TYPE_CANONICAL (arg))
return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
val);
else if (TREE_CODE (arg) == DECLTYPE_TYPE)
return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
/* Otherwise just compare the types during lookup. */
return val;
case tcc_declaration:
case tcc_constant:
return iterative_hash_expr (arg, val);
default:
gcc_assert (IS_EXPR_CODE_CLASS (tclass));
{
unsigned n = cp_tree_operand_length (arg);
for (i = 0; i < n; ++i)
val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
return val;
}
}
gcc_unreachable ();
return 0;
}
/* Unregister the specialization SPEC as a specialization of TMPL.
Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
if the SPEC was listed as a specialization of TMPL.
Note that SPEC has been ggc_freed, so we can't look inside it. */
bool
reregister_specialization (tree spec, tree tinfo, tree new_spec)
{
spec_entry *entry;
spec_entry elt;
elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
elt.args = TI_ARGS (tinfo);
elt.spec = NULL_TREE;
entry = decl_specializations->find (&elt);
if (entry != NULL)
{
gcc_assert (entry->spec == spec || entry->spec == new_spec);
gcc_assert (new_spec != NULL_TREE);
entry->spec = new_spec;
return 1;
}
return 0;
}
/* Like register_specialization, but for local declarations. We are
registering SPEC, an instantiation of TMPL. */
void
register_local_specialization (tree spec, tree tmpl)
{
gcc_assert (tmpl != spec);
local_specializations->put (tmpl, spec);
}
/* TYPE is a class type. Returns true if TYPE is an explicitly
specialized class. */
bool
explicit_class_specialization_p (tree type)
{
if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
return false;
return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
}
/* Print the list of functions at FNS, going through all the overloads
for each element of the list. Alternatively, FNS cannot be a
TREE_LIST, in which case it will be printed together with all the
overloads.
MORE and *STR should respectively be FALSE and NULL when the function
is called from the outside. They are used internally on recursive
calls. print_candidates manages the two parameters and leaves NULL
in *STR when it ends. */
static void
print_candidates_1 (tree fns, char **str, bool more = false)
{
if (TREE_CODE (fns) == TREE_LIST)
for (; fns; fns = TREE_CHAIN (fns))
print_candidates_1 (TREE_VALUE (fns), str, more || TREE_CHAIN (fns));
else
for (lkp_iterator iter (fns); iter;)
{
tree cand = *iter;
++iter;
const char *pfx = *str;
if (!pfx)
{
if (more || iter)
pfx = _("candidates are:");
else
pfx = _("candidate is:");
*str = get_spaces (pfx);
}
inform (DECL_SOURCE_LOCATION (cand), "%s %#qD", pfx, cand);
}
}
/* Print the list of candidate FNS in an error message. FNS can also
be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
void
print_candidates (tree fns)
{
char *str = NULL;
print_candidates_1 (fns, &str);
free (str);
}
/* Get a (possibly) constrained template declaration for the
purpose of ordering candidates. */
static tree
get_template_for_ordering (tree list)
{
gcc_assert (TREE_CODE (list) == TREE_LIST);
tree f = TREE_VALUE (list);
if (tree ti = DECL_TEMPLATE_INFO (f))
return TI_TEMPLATE (ti);
return f;
}
/* Among candidates having the same signature, return the
most constrained or NULL_TREE if there is no best candidate.
If the signatures of candidates vary (e.g., template
specialization vs. member function), then there can be no
most constrained.
Note that we don't compare constraints on the functions
themselves, but rather those of their templates. */
static tree
most_constrained_function (tree candidates)
{
// Try to find the best candidate in a first pass.
tree champ = candidates;
for (tree c = TREE_CHAIN (champ); c; c = TREE_CHAIN (c))
{
int winner = more_constrained (get_template_for_ordering (champ),
get_template_for_ordering (c));
if (winner == -1)
champ = c; // The candidate is more constrained
else if (winner == 0)
return NULL_TREE; // Neither is more constrained
}
// Verify that the champ is better than previous candidates.
for (tree c = candidates; c != champ; c = TREE_CHAIN (c)) {
if (!more_constrained (get_template_for_ordering (champ),
get_template_for_ordering (c)))
return NULL_TREE;
}
return champ;
}
/* Returns the template (one of the functions given by TEMPLATE_ID)
which can be specialized to match the indicated DECL with the
explicit template args given in TEMPLATE_ID. The DECL may be
NULL_TREE if none is available. In that case, the functions in
TEMPLATE_ID are non-members.
If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
specialization of a member template.
The TEMPLATE_COUNT is the number of references to qualifying
template classes that appeared in the name of the function. See
check_explicit_specialization for a more accurate description.
TSK indicates what kind of template declaration (if any) is being
declared. TSK_TEMPLATE indicates that the declaration given by
DECL, though a FUNCTION_DECL, has template parameters, and is
therefore a template function.
The template args (those explicitly specified and those deduced)
are output in a newly created vector *TARGS_OUT.
If it is impossible to determine the result, an error message is
issued. The error_mark_node is returned to indicate failure. */
static tree
determine_specialization (tree template_id,
tree decl,
tree* targs_out,
int need_member_template,
int template_count,
tmpl_spec_kind tsk)
{
tree fns;
tree targs;
tree explicit_targs;
tree candidates = NULL_TREE;
/* A TREE_LIST of templates of which DECL may be a specialization.
The TREE_VALUE of each node is a TEMPLATE_DECL. The
corresponding TREE_PURPOSE is the set of template arguments that,
when used to instantiate the template, would produce a function
with the signature of DECL. */
tree templates = NULL_TREE;
int header_count;
cp_binding_level *b;
*targs_out = NULL_TREE;
if (template_id == error_mark_node || decl == error_mark_node)
return error_mark_node;
/* We shouldn't be specializing a member template of an
unspecialized class template; we already gave an error in
check_specialization_scope, now avoid crashing. */
if (!VAR_P (decl)
&& template_count && DECL_CLASS_SCOPE_P (decl)
&& template_class_depth (DECL_CONTEXT (decl)) > 0)
{
gcc_assert (errorcount);
return error_mark_node;
}
fns = TREE_OPERAND (template_id, 0);
explicit_targs = TREE_OPERAND (template_id, 1);
if (fns == error_mark_node)
return error_mark_node;
/* Check for baselinks. */
if (BASELINK_P (fns))
fns = BASELINK_FUNCTIONS (fns);
if (TREE_CODE (decl) == FUNCTION_DECL && !is_overloaded_fn (fns))
{
error ("%qD is not a function template", fns);
return error_mark_node;
}
else if (VAR_P (decl) && !variable_template_p (fns))
{
error ("%qD is not a variable template", fns);
return error_mark_node;
}
/* Count the number of template headers specified for this
specialization. */
header_count = 0;
for (b = current_binding_level;
b->kind == sk_template_parms;
b = b->level_chain)
++header_count;
tree orig_fns = fns;
if (variable_template_p (fns))
{
tree parms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (fns));
targs = coerce_template_parms (parms, explicit_targs, fns,
tf_warning_or_error,
/*req_all*/true, /*use_defarg*/true);
if (targs != error_mark_node)
templates = tree_cons (targs, fns, templates);
}
else for (lkp_iterator iter (fns); iter; ++iter)
{
tree fn = *iter;
if (TREE_CODE (fn) == TEMPLATE_DECL)
{
tree decl_arg_types;
tree fn_arg_types;
tree insttype;
/* In case of explicit specialization, we need to check if
the number of template headers appearing in the specialization
is correct. This is usually done in check_explicit_specialization,
but the check done there cannot be exhaustive when specializing
member functions. Consider the following code:
template <> void A<int>::f(int);
template <> template <> void A<int>::f(int);
Assuming that A<int> is not itself an explicit specialization
already, the first line specializes "f" which is a non-template
member function, whilst the second line specializes "f" which
is a template member function. So both lines are syntactically
correct, and check_explicit_specialization does not reject
them.
Here, we can do better, as we are matching the specialization
against the declarations. We count the number of template
headers, and we check if they match TEMPLATE_COUNT + 1
(TEMPLATE_COUNT is the number of qualifying template classes,
plus there must be another header for the member template
itself).
Notice that if header_count is zero, this is not a
specialization but rather a template instantiation, so there
is no check we can perform here. */
if (header_count && header_count != template_count + 1)
continue;
/* Check that the number of template arguments at the
innermost level for DECL is the same as for FN. */
if (current_binding_level->kind == sk_template_parms
&& !current_binding_level->explicit_spec_p
&& (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
!= TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
(current_template_parms))))
continue;
/* DECL might be a specialization of FN. */
decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
/* For a non-static member function, we need to make sure
that the const qualification is the same. Since
get_bindings does not try to merge the "this" parameter,
we must do the comparison explicitly. */
if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
{
if (!same_type_p (TREE_VALUE (fn_arg_types),
TREE_VALUE (decl_arg_types)))
continue;
/* And the ref-qualification. */
if (type_memfn_rqual (TREE_TYPE (decl))
!= type_memfn_rqual (TREE_TYPE (fn)))
continue;
}
/* Skip the "this" parameter and, for constructors of
classes with virtual bases, the VTT parameter. A
full specialization of a constructor will have a VTT
parameter, but a template never will. */
decl_arg_types
= skip_artificial_parms_for (decl, decl_arg_types);
fn_arg_types
= skip_artificial_parms_for (fn, fn_arg_types);
/* Function templates cannot be specializations; there are
no partial specializations of functions. Therefore, if
the type of DECL does not match FN, there is no
match.
Note that it should never be the case that we have both
candidates added here, and for regular member functions
below. */
if (tsk == tsk_template)
{
if (compparms (fn_arg_types, decl_arg_types))
candidates = tree_cons (NULL_TREE, fn, candidates);
continue;
}
/* See whether this function might be a specialization of this
template. Suppress access control because we might be trying
to make this specialization a friend, and we have already done
access control for the declaration of the specialization. */
push_deferring_access_checks (dk_no_check);
targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
pop_deferring_access_checks ();
if (!targs)
/* We cannot deduce template arguments that when used to
specialize TMPL will produce DECL. */
continue;
if (uses_template_parms (targs))
/* We deduced something involving 'auto', which isn't a valid
template argument. */
continue;
/* Remove, from the set of candidates, all those functions
whose constraints are not satisfied. */
if (flag_concepts && !constraints_satisfied_p (fn, targs))
continue;
// Then, try to form the new function type.
insttype = tsubst (TREE_TYPE (fn), targs, tf_fndecl_type, NULL_TREE);
if (insttype == error_mark_node)
continue;
fn_arg_types
= skip_artificial_parms_for (fn, TYPE_ARG_TYPES (insttype));
if (!compparms (fn_arg_types, decl_arg_types))
continue;
/* Save this template, and the arguments deduced. */
templates = tree_cons (targs, fn, templates);
}
else if (need_member_template)
/* FN is an ordinary member function, and we need a
specialization of a member template. */
;
else if (TREE_CODE (fn) != FUNCTION_DECL)
/* We can get IDENTIFIER_NODEs here in certain erroneous
cases. */
;
else if (!DECL_FUNCTION_MEMBER_P (fn))
/* This is just an ordinary non-member function. Nothing can
be a specialization of that. */
;
else if (DECL_ARTIFICIAL (fn))
/* Cannot specialize functions that are created implicitly. */
;
else
{
tree decl_arg_types;
/* This is an ordinary member function. However, since
we're here, we can assume its enclosing class is a
template class. For example,
template <typename T> struct S { void f(); };
template <> void S<int>::f() {}
Here, S<int>::f is a non-template, but S<int> is a
template class. If FN has the same type as DECL, we
might be in business. */
if (!DECL_TEMPLATE_INFO (fn))
/* Its enclosing class is an explicit specialization
of a template class. This is not a candidate. */
continue;
if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
TREE_TYPE (TREE_TYPE (fn))))
/* The return types differ. */
continue;
/* Adjust the type of DECL in case FN is a static member. */
decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
if (DECL_STATIC_FUNCTION_P (fn)
&& DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
decl_arg_types = TREE_CHAIN (decl_arg_types);
if (!compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
decl_arg_types))
continue;
if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
&& (type_memfn_rqual (TREE_TYPE (decl))
!= type_memfn_rqual (TREE_TYPE (fn))))
continue;
// If the deduced arguments do not satisfy the constraints,
// this is not a candidate.
if (flag_concepts && !constraints_satisfied_p (fn))
continue;
// Add the candidate.
candidates = tree_cons (NULL_TREE, fn, candidates);
}
}
if (templates && TREE_CHAIN (templates))
{
/* We have:
[temp.expl.spec]
It is possible for a specialization with a given function
signature to be instantiated from more than one function
template. In such cases, explicit specification of the
template arguments must be used to uniquely identify the
function template specialization being specialized.
Note that here, there's no suggestion that we're supposed to
determine which of the candidate templates is most
specialized. However, we, also have:
[temp.func.order]
Partial ordering of overloaded function template
declarations is used in the following contexts to select
the function template to which a function template
specialization refers:
-- when an explicit specialization refers to a function
template.
So, we do use the partial ordering rules, at least for now.
This extension can only serve to make invalid programs valid,
so it's safe. And, there is strong anecdotal evidence that
the committee intended the partial ordering rules to apply;
the EDG front end has that behavior, and John Spicer claims
that the committee simply forgot to delete the wording in
[temp.expl.spec]. */
tree tmpl = most_specialized_instantiation (templates);
if (tmpl != error_mark_node)
{
templates = tmpl;
TREE_CHAIN (templates) = NULL_TREE;
}
}
// Concepts allows multiple declarations of member functions
// with the same signature. Like above, we need to rely on
// on the partial ordering of those candidates to determine which
// is the best.
if (flag_concepts && candidates && TREE_CHAIN (candidates))
{
if (tree cand = most_constrained_function (candidates))
{
candidates = cand;
TREE_CHAIN (cand) = NULL_TREE;
}
}
if (templates == NULL_TREE && candidates == NULL_TREE)
{
error ("template-id %qD for %q+D does not match any template "
"declaration", template_id, decl);
if (header_count && header_count != template_count + 1)
inform (input_location, "saw %d %<template<>%>, need %d for "
"specializing a member function template",
header_count, template_count + 1);
else
print_candidates (orig_fns);
return error_mark_node;
}
else if ((templates && TREE_CHAIN (templates))
|| (candidates && TREE_CHAIN (candidates))
|| (templates && candidates))
{
error ("ambiguous template specialization %qD for %q+D",
template_id, decl);
candidates = chainon (candidates, templates);
print_candidates (candidates);
return error_mark_node;
}
/* We have one, and exactly one, match. */
if (candidates)
{
tree fn = TREE_VALUE (candidates);
*targs_out = copy_node (DECL_TI_ARGS (fn));
// Propagate the candidate's constraints to the declaration.
set_constraints (decl, get_constraints (fn));
/* DECL is a re-declaration or partial instantiation of a template
function. */
if (TREE_CODE (fn) == TEMPLATE_DECL)
return fn;
/* It was a specialization of an ordinary member function in a
template class. */
return DECL_TI_TEMPLATE (fn);
}
/* It was a specialization of a template. */
targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
{
*targs_out = copy_node (targs);
SET_TMPL_ARGS_LEVEL (*targs_out,
TMPL_ARGS_DEPTH (*targs_out),
TREE_PURPOSE (templates));
}
else
*targs_out = TREE_PURPOSE (templates);
return TREE_VALUE (templates);
}
/* Returns a chain of parameter types, exactly like the SPEC_TYPES,
but with the default argument values filled in from those in the
TMPL_TYPES. */
static tree
copy_default_args_to_explicit_spec_1 (tree spec_types,
tree tmpl_types)
{
tree new_spec_types;
if (!spec_types)
return NULL_TREE;
if (spec_types == void_list_node)
return void_list_node;
/* Substitute into the rest of the list. */
new_spec_types =
copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
TREE_CHAIN (tmpl_types));
/* Add the default argument for this parameter. */
return hash_tree_cons (TREE_PURPOSE (tmpl_types),
TREE_VALUE (spec_types),
new_spec_types);
}
/* DECL is an explicit specialization. Replicate default arguments
from the template it specializes. (That way, code like:
template <class T> void f(T = 3);
template <> void f(double);
void g () { f (); }
works, as required.) An alternative approach would be to look up
the correct default arguments at the call-site, but this approach
is consistent with how implicit instantiations are handled. */
static void
copy_default_args_to_explicit_spec (tree decl)
{
tree tmpl;
tree spec_types;
tree tmpl_types;
tree new_spec_types;
tree old_type;
tree new_type;
tree t;
tree object_type = NULL_TREE;
tree in_charge = NULL_TREE;
tree vtt = NULL_TREE;
/* See if there's anything we need to do. */
tmpl = DECL_TI_TEMPLATE (decl);
tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
for (t = tmpl_types; t; t = TREE_CHAIN (t))
if (TREE_PURPOSE (t))
break;
if (!t)
return;
old_type = TREE_TYPE (decl);
spec_types = TYPE_ARG_TYPES (old_type);
if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
{
/* Remove the this pointer, but remember the object's type for
CV quals. */
object_type = TREE_TYPE (TREE_VALUE (spec_types));
spec_types = TREE_CHAIN (spec_types);
tmpl_types = TREE_CHAIN (tmpl_types);
if (DECL_HAS_IN_CHARGE_PARM_P (decl))
{
/* DECL may contain more parameters than TMPL due to the extra
in-charge parameter in constructors and destructors. */
in_charge = spec_types;
spec_types = TREE_CHAIN (spec_types);
}
if (DECL_HAS_VTT_PARM_P (decl))
{
vtt = spec_types;
spec_types = TREE_CHAIN (spec_types);
}
}
/* Compute the merged default arguments. */
new_spec_types =
copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
/* Compute the new FUNCTION_TYPE. */
if (object_type)
{
if (vtt)
new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
TREE_VALUE (vtt),
new_spec_types);
if (in_charge)
/* Put the in-charge parameter back. */
new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
TREE_VALUE (in_charge),
new_spec_types);
new_type = build_method_type_directly (object_type,
TREE_TYPE (old_type),
new_spec_types);
}
else
new_type = build_function_type (TREE_TYPE (old_type),
new_spec_types);
new_type = cp_build_type_attribute_variant (new_type,
TYPE_ATTRIBUTES (old_type));
new_type = cxx_copy_lang_qualifiers (new_type, old_type);
TREE_TYPE (decl) = new_type;
}
/* Return the number of template headers we expect to see for a definition
or specialization of CTYPE or one of its non-template members. */
int
num_template_headers_for_class (tree ctype)
{
int num_templates = 0;
while (ctype && CLASS_TYPE_P (ctype))
{
/* You're supposed to have one `template <...>' for every
template class, but you don't need one for a full
specialization. For example:
template <class T> struct S{};
template <> struct S<int> { void f(); };
void S<int>::f () {}
is correct; there shouldn't be a `template <>' for the
definition of `S<int>::f'. */
if (!CLASSTYPE_TEMPLATE_INFO (ctype))
/* If CTYPE does not have template information of any
kind, then it is not a template, nor is it nested
within a template. */
break;
if (explicit_class_specialization_p (ctype))
break;
if (PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (ctype)))
++num_templates;
ctype = TYPE_CONTEXT (ctype);
}
return num_templates;
}
/* Do a simple sanity check on the template headers that precede the
variable declaration DECL. */
void
check_template_variable (tree decl)
{
tree ctx = CP_DECL_CONTEXT (decl);
int wanted = num_template_headers_for_class (ctx);
if (DECL_LANG_SPECIFIC (decl) && DECL_TEMPLATE_INFO (decl)
&& PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl)))
{
if (cxx_dialect < cxx14)
pedwarn (DECL_SOURCE_LOCATION (decl), 0,
"variable templates only available with "
"%<-std=c++14%> or %<-std=gnu++14%>");
// Namespace-scope variable templates should have a template header.
++wanted;
}
if (template_header_count > wanted)
{
auto_diagnostic_group d;
bool warned = pedwarn (DECL_SOURCE_LOCATION (decl), 0,
"too many template headers for %qD "
"(should be %d)",
decl, wanted);
if (warned && CLASS_TYPE_P (ctx)
&& CLASSTYPE_TEMPLATE_SPECIALIZATION (ctx))
inform (DECL_SOURCE_LOCATION (decl),
"members of an explicitly specialized class are defined "
"without a template header");
}
}
/* An explicit specialization whose declarator-id or class-head-name is not
qualified shall be declared in the nearest enclosing namespace of the
template, or, if the namespace is inline (7.3.1), any namespace from its
enclosing namespace set.
If the name declared in the explicit instantiation is an unqualified name,
the explicit instantiation shall appear in the namespace where its template
is declared or, if that namespace is inline (7.3.1), any namespace from its
enclosing namespace set. */
void
check_unqualified_spec_or_inst (tree t, location_t loc)
{
tree tmpl = most_general_template (t);
if (DECL_NAMESPACE_SCOPE_P (tmpl)
&& !is_nested_namespace (current_namespace,
CP_DECL_CONTEXT (tmpl), true))
{
if (processing_specialization)
permerror (loc, "explicit specialization of %qD outside its "
"namespace must use a nested-name-specifier", tmpl);
else if (processing_explicit_instantiation
&& cxx_dialect >= cxx11)
/* This was allowed in C++98, so only pedwarn. */
pedwarn (loc, OPT_Wpedantic, "explicit instantiation of %qD "
"outside its namespace must use a nested-name-"
"specifier", tmpl);
}
}
/* Warn for a template specialization SPEC that is missing some of a set
of function or type attributes that the template TEMPL is declared with.
ATTRLIST is a list of additional attributes that SPEC should be taken
to ultimately be declared with. */
static void
warn_spec_missing_attributes (tree tmpl, tree spec, tree attrlist)
{
if (DECL_FUNCTION_TEMPLATE_P (tmpl))
tmpl = DECL_TEMPLATE_RESULT (tmpl);
/* Avoid warning if the difference between the primary and
the specialization is not in one of the attributes below. */
const char* const blacklist[] = {
"alloc_align", "alloc_size", "assume_aligned", "format",
"format_arg", "malloc", "nonnull", NULL
};
/* Put together a list of the black listed attributes that the primary
template is declared with that the specialization is not, in case
it's not apparent from the most recent declaration of the primary. */
pretty_printer str;
unsigned nattrs = decls_mismatched_attributes (tmpl, spec, attrlist,
blacklist, &str);
if (!nattrs)
return;
auto_diagnostic_group d;
if (warning_at (DECL_SOURCE_LOCATION (spec), OPT_Wmissing_attributes,
"explicit specialization %q#D may be missing attributes",
spec))
inform (DECL_SOURCE_LOCATION (tmpl),
nattrs > 1
? G_("missing primary template attributes %s")
: G_("missing primary template attribute %s"),
pp_formatted_text (&str));
}
/* Check to see if the function just declared, as indicated in
DECLARATOR, and in DECL, is a specialization of a function
template. We may also discover that the declaration is an explicit
instantiation at this point.
Returns DECL, or an equivalent declaration that should be used
instead if all goes well. Issues an error message if something is
amiss. Returns error_mark_node if the error is not easily
recoverable.
FLAGS is a bitmask consisting of the following flags:
2: The function has a definition.
4: The function is a friend.
The TEMPLATE_COUNT is the number of references to qualifying
template classes that appeared in the name of the function. For
example, in
template <class T> struct S { void f(); };
void S<int>::f();
the TEMPLATE_COUNT would be 1. However, explicitly specialized
classes are not counted in the TEMPLATE_COUNT, so that in
template <class T> struct S {};
template <> struct S<int> { void f(); }
template <> void S<int>::f();
the TEMPLATE_COUNT would be 0. (Note that this declaration is
invalid; there should be no template <>.)
If the function is a specialization, it is marked as such via
DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
is set up correctly, and it is added to the list of specializations
for that template. */
tree
check_explicit_specialization (tree declarator,
tree decl,
int template_count,
int flags,
tree attrlist)
{
int have_def = flags & 2;
int is_friend = flags & 4;
bool is_concept = flags & 8;
int specialization = 0;
int explicit_instantiation = 0;
int member_specialization = 0;
tree ctype = DECL_CLASS_CONTEXT (decl);
tree dname = DECL_NAME (decl);
tmpl_spec_kind tsk;
if (is_friend)
{
if (!processing_specialization)
tsk = tsk_none;
else
tsk = tsk_excessive_parms;
}
else
tsk = current_tmpl_spec_kind (template_count);
switch (tsk)
{
case tsk_none:
if (processing_specialization && !VAR_P (decl))
{
specialization = 1;
SET_DECL_TEMPLATE_SPECIALIZATION (decl);
}
else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
{
if (is_friend)
/* This could be something like:
template <class T> void f(T);
class S { friend void f<>(int); } */
specialization = 1;
else
{
/* This case handles bogus declarations like template <>
template <class T> void f<int>(); */
error ("template-id %qD in declaration of primary template",
declarator);
return decl;
}
}
break;
case tsk_invalid_member_spec:
/* The error has already been reported in
check_specialization_scope. */
return error_mark_node;
case tsk_invalid_expl_inst:
error ("template parameter list used in explicit instantiation");
/* Fall through. */
case tsk_expl_inst:
if (have_def)
error ("definition provided for explicit instantiation");
explicit_instantiation = 1;
break;
case tsk_excessive_parms:
case tsk_insufficient_parms:
if (tsk == tsk_excessive_parms)
error ("too many template parameter lists in declaration of %qD",
decl);
else if (template_header_count)
error("too few template parameter lists in declaration of %qD", decl);
else
error("explicit specialization of %qD must be introduced by "
"%<template <>%>", decl);
/* Fall through. */
case tsk_expl_spec:
if (is_concept)
error ("explicit specialization declared %<concept%>");
if (VAR_P (decl) && TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
/* In cases like template<> constexpr bool v = true;
We'll give an error in check_template_variable. */
break;
SET_DECL_TEMPLATE_SPECIALIZATION (decl);
if (ctype)
member_specialization = 1;
else
specialization = 1;
break;
case tsk_template:
if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
{
/* This case handles bogus declarations like template <>
template <class T> void f<int>(); */
if (!uses_template_parms (TREE_OPERAND (declarator, 1)))
error ("template-id %qD in declaration of primary template",
declarator);
else if (variable_template_p (TREE_OPERAND (declarator, 0)))
{
/* Partial specialization of variable template. */
SET_DECL_TEMPLATE_SPECIALIZATION (decl);
specialization = 1;
goto ok;
}
else if (cxx_dialect < cxx14)
error ("non-type partial specialization %qD "
"is not allowed", declarator);
else
error ("non-class, non-variable partial specialization %qD "
"is not allowed", declarator);
return decl;
ok:;
}
if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
/* This is a specialization of a member template, without
specialization the containing class. Something like:
template <class T> struct S {
template <class U> void f (U);
};
template <> template <class U> void S<int>::f(U) {}
That's a specialization -- but of the entire template. */
specialization = 1;
break;
default:
gcc_unreachable ();
}
if ((specialization || member_specialization)
/* This doesn't apply to variable templates. */
&& (TREE_CODE (TREE_TYPE (decl)) == FUNCTION_TYPE
|| TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE))
{
tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
for (; t; t = TREE_CHAIN (t))
if (TREE_PURPOSE (t))
{
permerror (input_location,
"default argument specified in explicit specialization");
break;
}
}
if (specialization || member_specialization || explicit_instantiation)
{
tree tmpl = NULL_TREE;
tree targs = NULL_TREE;
bool was_template_id = (TREE_CODE (declarator) == TEMPLATE_ID_EXPR);
/* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
if (!was_template_id)
{
tree fns;
gcc_assert (identifier_p (declarator));
if (ctype)
fns = dname;
else
{
/* If there is no class context, the explicit instantiation
must be at namespace scope. */
gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
/* Find the namespace binding, using the declaration
context. */
fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
false, true);
if (fns == error_mark_node)
/* If lookup fails, look for a friend declaration so we can
give a better diagnostic. */
fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
/*type*/false, /*complain*/true,
/*hidden*/true);
if (fns == error_mark_node || !is_overloaded_fn (fns))
{
error ("%qD is not a template function", dname);
fns = error_mark_node;
}
}
declarator = lookup_template_function (fns, NULL_TREE);
}
if (declarator == error_mark_node)
return error_mark_node;
if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
{
if (!explicit_instantiation)
/* A specialization in class scope. This is invalid,
but the error will already have been flagged by
check_specialization_scope. */
return error_mark_node;
else
{
/* It's not valid to write an explicit instantiation in
class scope, e.g.:
class C { template void f(); }
This case is caught by the parser. However, on
something like:
template class C { void f(); };
(which is invalid) we can get here. The error will be
issued later. */
;
}
return decl;
}
else if (ctype != NULL_TREE
&& (identifier_p (TREE_OPERAND (declarator, 0))))
{
// We'll match variable templates in start_decl.
if (VAR_P (decl))
return decl;
/* Find the list of functions in ctype that have the same
name as the declared function. */
tree name = TREE_OPERAND (declarator, 0);
if (constructor_name_p (name, ctype))
{
if (DECL_CONSTRUCTOR_P (decl)
? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
: !CLASSTYPE_DESTRUCTOR (ctype))
{
/* From [temp.expl.spec]:
If such an explicit specialization for the member
of a class template names an implicitly-declared
special member function (clause _special_), the
program is ill-formed.
Similar language is found in [temp.explicit]. */
error ("specialization of implicitly-declared special member function");
return error_mark_node;
}
name = DECL_NAME (decl);
}
/* For a type-conversion operator, We might be looking for
`operator int' which will be a specialization of
`operator T'. Grab all the conversion operators, and
then select from them. */
tree fns = get_class_binding (ctype, IDENTIFIER_CONV_OP_P (name)
? conv_op_identifier : name);
if (fns == NULL_TREE)
{
error ("no member function %qD declared in %qT", name, ctype);
return error_mark_node;
}
else
TREE_OPERAND (declarator, 0) = fns;
}
/* Figure out what exactly is being specialized at this point.
Note that for an explicit instantiation, even one for a
member function, we cannot tell a priori whether the
instantiation is for a member template, or just a member
function of a template class. Even if a member template is
being instantiated, the member template arguments may be
elided if they can be deduced from the rest of the
declaration. */
tmpl = determine_specialization (declarator, decl,
&targs,
member_specialization,
template_count,
tsk);
if (!tmpl || tmpl == error_mark_node)
/* We couldn't figure out what this declaration was
specializing. */
return error_mark_node;
else
{
if (TREE_CODE (decl) == FUNCTION_DECL
&& DECL_HIDDEN_FRIEND_P (tmpl))
{
auto_diagnostic_group d;
if (pedwarn (DECL_SOURCE_LOCATION (decl), 0,
"friend declaration %qD is not visible to "
"explicit specialization", tmpl))
inform (DECL_SOURCE_LOCATION (tmpl),
"friend declaration here");
}
else if (!ctype && !is_friend
&& CP_DECL_CONTEXT (decl) == current_namespace)
check_unqualified_spec_or_inst (tmpl, DECL_SOURCE_LOCATION (decl));
tree gen_tmpl = most_general_template (tmpl);
if (explicit_instantiation)
{
/* We don't set DECL_EXPLICIT_INSTANTIATION here; that
is done by do_decl_instantiation later. */
int arg_depth = TMPL_ARGS_DEPTH (targs);
int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
if (arg_depth > parm_depth)
{
/* If TMPL is not the most general template (for
example, if TMPL is a friend template that is
injected into namespace scope), then there will
be too many levels of TARGS. Remove some of them
here. */
int i;
tree new_targs;
new_targs = make_tree_vec (parm_depth);
for (i = arg_depth - parm_depth; i < arg_depth; ++i)
TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
= TREE_VEC_ELT (targs, i);
targs = new_targs;
}
return instantiate_template (tmpl, targs, tf_error);
}
/* If we thought that the DECL was a member function, but it
turns out to be specializing a static member function,
make DECL a static member function as well. */
if (DECL_FUNCTION_TEMPLATE_P (tmpl)
&& DECL_STATIC_FUNCTION_P (tmpl)
&& DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
revert_static_member_fn (decl);
/* If this is a specialization of a member template of a
template class, we want to return the TEMPLATE_DECL, not
the specialization of it. */
if (tsk == tsk_template && !was_template_id)
{
tree result = DECL_TEMPLATE_RESULT (tmpl);
SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
DECL_INITIAL (result) = NULL_TREE;
if (have_def)
{
tree parm;
DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
DECL_SOURCE_LOCATION (result)
= DECL_SOURCE_LOCATION (decl);
/* We want to use the argument list specified in the
definition, not in the original declaration. */
DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
for (parm = DECL_ARGUMENTS (result); parm;
parm = DECL_CHAIN (parm))
DECL_CONTEXT (parm) = result;
}
return register_specialization (tmpl, gen_tmpl, targs,
is_friend, 0);
}
/* Set up the DECL_TEMPLATE_INFO for DECL. */
DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
if (was_template_id)
TINFO_USED_TEMPLATE_ID (DECL_TEMPLATE_INFO (decl)) = true;
/* Inherit default function arguments from the template
DECL is specializing. */
if (DECL_FUNCTION_TEMPLATE_P (tmpl))
copy_default_args_to_explicit_spec (decl);
/* This specialization has the same protection as the
template it specializes. */
TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
/* 7.1.1-1 [dcl.stc]
A storage-class-specifier shall not be specified in an
explicit specialization...
The parser rejects these, so unless action is taken here,
explicit function specializations will always appear with
global linkage.
The action recommended by the C++ CWG in response to C++
defect report 605 is to make the storage class and linkage
of the explicit specialization match the templated function:
http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
*/
if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
{
tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
/* A concept cannot be specialized. */
if (DECL_DECLARED_CONCEPT_P (tmpl_func))
{
error ("explicit specialization of function concept %qD",
gen_tmpl);
return error_mark_node;
}
/* This specialization has the same linkage and visibility as
the function template it specializes. */
TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
if (! TREE_PUBLIC (decl))
{
DECL_INTERFACE_KNOWN (decl) = 1;
DECL_NOT_REALLY_EXTERN (decl) = 1;
}
DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
{
DECL_VISIBILITY_SPECIFIED (decl) = 1;
DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
}
}
/* If DECL is a friend declaration, declared using an
unqualified name, the namespace associated with DECL may
have been set incorrectly. For example, in:
template <typename T> void f(T);
namespace N {
struct S { friend void f<int>(int); }
}
we will have set the DECL_CONTEXT for the friend
declaration to N, rather than to the global namespace. */
if (DECL_NAMESPACE_SCOPE_P (decl))
DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
if (is_friend && !have_def)
/* This is not really a declaration of a specialization.
It's just the name of an instantiation. But, it's not
a request for an instantiation, either. */
SET_DECL_IMPLICIT_INSTANTIATION (decl);
else if (TREE_CODE (decl) == FUNCTION_DECL)
/* A specialization is not necessarily COMDAT. */
DECL_COMDAT (decl) = (TREE_PUBLIC (decl)
&& DECL_DECLARED_INLINE_P (decl));
else if (VAR_P (decl))
DECL_COMDAT (decl) = false;
/* If this is a full specialization, register it so that we can find
it again. Partial specializations will be registered in
process_partial_specialization. */
if (!processing_template_decl)
{
warn_spec_missing_attributes (gen_tmpl, decl, attrlist);
decl = register_specialization (decl, gen_tmpl, targs,
is_friend, 0);
}
/* A 'structor should already have clones. */
gcc_assert (decl == error_mark_node
|| variable_template_p (tmpl)
|| !(DECL_CONSTRUCTOR_P (decl)
|| DECL_DESTRUCTOR_P (decl))
|| DECL_CLONED_FUNCTION_P (DECL_CHAIN (decl)));
}
}
return decl;
}
/* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
parameters. These are represented in the same format used for
DECL_TEMPLATE_PARMS. */
int
comp_template_parms (const_tree parms1, const_tree parms2)
{
const_tree p1;
const_tree p2;
if (parms1 == parms2)
return 1;
for (p1 = parms1, p2 = parms2;
p1 != NULL_TREE && p2 != NULL_TREE;
p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
{
tree t1 = TREE_VALUE (p1);
tree t2 = TREE_VALUE (p2);
int i;
gcc_assert (TREE_CODE (t1) == TREE_VEC);
gcc_assert (TREE_CODE (t2) == TREE_VEC);
if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
return 0;
for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
{
tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
/* If either of the template parameters are invalid, assume
they match for the sake of error recovery. */
if (error_operand_p (parm1) || error_operand_p (parm2))
return 1;
if (TREE_CODE (parm1) != TREE_CODE (parm2))
return 0;
if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
&& (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
== TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
continue;
else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
return 0;
}
}
if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
/* One set of parameters has more parameters lists than the
other. */
return 0;
return 1;
}
/* Determine whether PARM is a parameter pack. */
bool
template_parameter_pack_p (const_tree parm)
{
/* Determine if we have a non-type template parameter pack. */
if (TREE_CODE (parm) == PARM_DECL)
return (DECL_TEMPLATE_PARM_P (parm)
&& TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX)
return TEMPLATE_PARM_PARAMETER_PACK (parm);
/* If this is a list of template parameters, we could get a
TYPE_DECL or a TEMPLATE_DECL. */
if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
parm = TREE_TYPE (parm);
/* Otherwise it must be a type template parameter. */
return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
|| TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
&& TEMPLATE_TYPE_PARAMETER_PACK (parm));
}
/* Determine if T is a function parameter pack. */
bool
function_parameter_pack_p (const_tree t)
{
if (t && TREE_CODE (t) == PARM_DECL)
return DECL_PACK_P (t);
return false;
}
/* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
tree
get_function_template_decl (const_tree primary_func_tmpl_inst)
{
if (! primary_func_tmpl_inst
|| TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
|| ! primary_template_specialization_p (primary_func_tmpl_inst))
return NULL;
return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
}
/* Return true iff the function parameter PARAM_DECL was expanded
from the function parameter pack PACK. */
bool
function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
{
if (DECL_ARTIFICIAL (param_decl)
|| !function_parameter_pack_p (pack))
return false;
/* The parameter pack and its pack arguments have the same
DECL_PARM_INDEX. */
return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
}
/* Determine whether ARGS describes a variadic template args list,
i.e., one that is terminated by a template argument pack. */
static bool
template_args_variadic_p (tree args)
{
int nargs;
tree last_parm;
if (args == NULL_TREE)
return false;
args = INNERMOST_TEMPLATE_ARGS (args);
nargs = TREE_VEC_LENGTH (args);
if (nargs == 0)
return false;
last_parm = TREE_VEC_ELT (args, nargs - 1);
return ARGUMENT_PACK_P (last_parm);
}
/* Generate a new name for the parameter pack name NAME (an
IDENTIFIER_NODE) that incorporates its */
static tree
make_ith_pack_parameter_name (tree name, int i)
{
/* Munge the name to include the parameter index. */
#define NUMBUF_LEN 128
char numbuf[NUMBUF_LEN];
char* newname;
int newname_len;
if (name == NULL_TREE)
return name;
snprintf (numbuf, NUMBUF_LEN, "%i", i);
newname_len = IDENTIFIER_LENGTH (name)
+ strlen (numbuf) + 2;
newname = (char*)alloca (newname_len);
snprintf (newname, newname_len,
"%s#%i", IDENTIFIER_POINTER (name), i);
return get_identifier (newname);
}
/* Return true if T is a primary function, class or alias template
specialization, not including the template pattern. */
bool
primary_template_specialization_p (const_tree t)
{
if (!t)
return false;
if (TREE_CODE (t) == FUNCTION_DECL || VAR_P (t))
return (DECL_LANG_SPECIFIC (t)
&& DECL_USE_TEMPLATE (t)
&& DECL_TEMPLATE_INFO (t)
&& PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t)));
else if (CLASS_TYPE_P (t) && !TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
return (CLASSTYPE_TEMPLATE_INFO (t)
&& CLASSTYPE_USE_TEMPLATE (t)
&& PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t)));
else if (alias_template_specialization_p (t))
return true;
return false;
}
/* Return true if PARM is a template template parameter. */
bool
template_template_parameter_p (const_tree parm)
{
return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
}
/* Return true iff PARM is a DECL representing a type template
parameter. */
bool
template_type_parameter_p (const_tree parm)
{
return (parm
&& (TREE_CODE (parm) == TYPE_DECL
|| TREE_CODE (parm) == TEMPLATE_DECL)
&& DECL_TEMPLATE_PARM_P (parm));
}
/* Return the template parameters of T if T is a
primary template instantiation, NULL otherwise. */
tree
get_primary_template_innermost_parameters (const_tree t)
{
tree parms = NULL, template_info = NULL;
if ((template_info = get_template_info (t))
&& primary_template_specialization_p (t))
parms = INNERMOST_TEMPLATE_PARMS
(DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
return parms;
}
/* Return the template parameters of the LEVELth level from the full list
of template parameters PARMS. */
tree
get_template_parms_at_level (tree parms, int level)
{
tree p;
if (!parms
|| TREE_CODE (parms) != TREE_LIST
|| level > TMPL_PARMS_DEPTH (parms))
return NULL_TREE;
for (p = parms; p; p = TREE_CHAIN (p))
if (TMPL_PARMS_DEPTH (p) == level)
return p;
return NULL_TREE;
}
/* Returns the template arguments of T if T is a template instantiation,
NULL otherwise. */
tree
get_template_innermost_arguments (const_tree t)
{
tree args = NULL, template_info = NULL;
if ((template_info = get_template_info (t))
&& TI_ARGS (template_info))
args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
return args;
}
/* Return the argument pack elements of T if T is a template argument pack,
NULL otherwise. */
tree
get_template_argument_pack_elems (const_tree t)
{
if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
&& TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
return NULL;
return ARGUMENT_PACK_ARGS (t);
}
/* In an ARGUMENT_PACK_SELECT, the actual underlying argument that the
ARGUMENT_PACK_SELECT represents. */
static tree
argument_pack_select_arg (tree t)
{
tree args = ARGUMENT_PACK_ARGS (ARGUMENT_PACK_SELECT_FROM_PACK (t));
tree arg = TREE_VEC_ELT (args, ARGUMENT_PACK_SELECT_INDEX (t));
/* If the selected argument is an expansion E, that most likely means we were
called from gen_elem_of_pack_expansion_instantiation during the
substituting of an argument pack (of which the Ith element is a pack
expansion, where I is ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
In this case, the Ith element resulting from this substituting is going to
be a pack expansion, which pattern is the pattern of E. Let's return the
pattern of E, and gen_elem_of_pack_expansion_instantiation will build the
resulting pack expansion from it. */
if (PACK_EXPANSION_P (arg))
{
/* Make sure we aren't throwing away arg info. */
gcc_assert (!PACK_EXPANSION_EXTRA_ARGS (arg));
arg = PACK_EXPANSION_PATTERN (arg);
}
return arg;
}
/* True iff FN is a function representing a built-in variadic parameter
pack. */
bool
builtin_pack_fn_p (tree fn)
{
if (!fn
|| TREE_CODE (fn) != FUNCTION_DECL
|| !DECL_IS_BUILTIN (fn))
return false;
if (id_equal (DECL_NAME (fn), "__integer_pack"))
return true;
return false;
}
/* True iff CALL is a call to a function representing a built-in variadic
parameter pack. */
static bool
builtin_pack_call_p (tree call)
{
if (TREE_CODE (call) != CALL_EXPR)
return false;
return builtin_pack_fn_p (CALL_EXPR_FN (call));
}
/* Return a TREE_VEC for the expansion of __integer_pack(HI). */
static tree
expand_integer_pack (tree call, tree args, tsubst_flags_t complain,
tree in_decl)
{
tree ohi = CALL_EXPR_ARG (call, 0);
tree hi = tsubst_copy_and_build (ohi, args, complain, in_decl,
false/*fn*/, true/*int_cst*/);
if (value_dependent_expression_p (hi))
{
if (hi != ohi)
{
call = copy_node (call);
CALL_EXPR_ARG (call, 0) = hi;
}
tree ex = make_pack_expansion (call, complain);
tree vec = make_tree_vec (1);
TREE_VEC_ELT (vec, 0) = ex;
return vec;
}
else
{
hi = cxx_constant_value (hi);
int len = valid_constant_size_p (hi) ? tree_to_shwi (hi) : -1;
/* Calculate the largest value of len that won't make the size of the vec
overflow an int. The compiler will exceed resource limits long before
this, but it seems a decent place to diagnose. */
int max = ((INT_MAX - sizeof (tree_vec)) / sizeof (tree)) + 1;
if (len < 0 || len > max)
{
if ((complain & tf_error)
&& hi != error_mark_node)
error ("argument to __integer_pack must be between 0 and %d", max);
return error_mark_node;
}
tree vec = make_tree_vec (len);
for (int i = 0; i < len; ++i)
TREE_VEC_ELT (vec, i) = size_int (i);
return vec;
}
}
/* Return a TREE_VEC for the expansion of built-in template parameter pack
CALL. */
static tree
expand_builtin_pack_call (tree call, tree args, tsubst_flags_t complain,
tree in_decl)
{
if (!builtin_pack_call_p (call))
return NULL_TREE;
tree fn = CALL_EXPR_FN (call);
if (id_equal (DECL_NAME (fn), "__integer_pack"))
return expand_integer_pack (call, args, complain, in_decl);
return NULL_TREE;
}
/* Structure used to track the progress of find_parameter_packs_r. */
struct find_parameter_pack_data
{
/* TREE_LIST that will contain all of the parameter packs found by
the traversal. */
tree* parameter_packs;
/* Set of AST nodes that have been visited by the traversal. */
hash_set<tree> *visited;
/* True iff we're making a type pack expansion. */
bool type_pack_expansion_p;
};
/* Identifies all of the argument packs that occur in a template
argument and appends them to the TREE_LIST inside DATA, which is a
find_parameter_pack_data structure. This is a subroutine of
make_pack_expansion and uses_parameter_packs. */
static tree
find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
{
tree t = *tp;
struct find_parameter_pack_data* ppd =
(struct find_parameter_pack_data*)data;
bool parameter_pack_p = false;
/* Handle type aliases/typedefs. */
if (TYPE_ALIAS_P (t))
{
if (tree tinfo = TYPE_ALIAS_TEMPLATE_INFO (t))
cp_walk_tree (&TI_ARGS (tinfo),
&find_parameter_packs_r,
ppd, ppd->visited);
*walk_subtrees = 0;
return NULL_TREE;
}
/* Identify whether this is a parameter pack or not. */
switch (TREE_CODE (t))
{
case TEMPLATE_PARM_INDEX:
if (TEMPLATE_PARM_PARAMETER_PACK (t))
parameter_pack_p = true;
break;
case TEMPLATE_TYPE_PARM:
t = TYPE_MAIN_VARIANT (t);
/* FALLTHRU */
case TEMPLATE_TEMPLATE_PARM:
/* If the placeholder appears in the decl-specifier-seq of a function
parameter pack (14.6.3), or the type-specifier-seq of a type-id that
is a pack expansion, the invented template parameter is a template
parameter pack. */
if (ppd->type_pack_expansion_p && is_auto (t))
TEMPLATE_TYPE_PARAMETER_PACK (t) = true;
if (TEMPLATE_TYPE_PARAMETER_PACK (t))
parameter_pack_p = true;
break;
case FIELD_DECL:
case PARM_DECL:
if (DECL_PACK_P (t))
{
/* We don't want to walk into the type of a PARM_DECL,
because we don't want to see the type parameter pack. */
*walk_subtrees = 0;
parameter_pack_p = true;
}
break;
case VAR_DECL:
if (DECL_PACK_P (t))
{
/* We don't want to walk into the type of a variadic capture proxy,
because we don't want to see the type parameter pack. */
*walk_subtrees = 0;
parameter_pack_p = true;
}
else if (variable_template_specialization_p (t))
{
cp_walk_tree (&DECL_TI_ARGS (t),
find_parameter_packs_r,
ppd, ppd->visited);
*walk_subtrees = 0;
}
break;
case CALL_EXPR:
if (builtin_pack_call_p (t))
parameter_pack_p = true;
break;
case BASES:
parameter_pack_p = true;
break;
default:
/* Not a parameter pack. */
break;
}
if (parameter_pack_p)
{
/* Add this parameter pack to the list. */
*ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
}
if (TYPE_P (t))
cp_walk_tree (&TYPE_CONTEXT (t),
&find_parameter_packs_r, ppd, ppd->visited);
/* This switch statement will return immediately if we don't find a
parameter pack. */
switch (TREE_CODE (t))
{
case TEMPLATE_PARM_INDEX:
return NULL_TREE;
case BOUND_TEMPLATE_TEMPLATE_PARM:
/* Check the template itself. */
cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
&find_parameter_packs_r, ppd, ppd->visited);
/* Check the template arguments. */
cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
ppd->visited);
*walk_subtrees = 0;
return NULL_TREE;
case TEMPLATE_TYPE_PARM:
case TEMPLATE_TEMPLATE_PARM:
return NULL_TREE;
case PARM_DECL:
return NULL_TREE;
case DECL_EXPR:
{
tree decl = DECL_EXPR_DECL (t);
/* Ignore the declaration of a capture proxy for a parameter pack. */
if (is_capture_proxy (decl))
*walk_subtrees = 0;
if (is_typedef_decl (decl) && TYPE_ALIAS_P (TREE_TYPE (decl)))
/* Since we stop at aliases above, we need to look through them at
the point of the DECL_EXPR. */
cp_walk_tree (&DECL_ORIGINAL_TYPE (decl),
&find_parameter_packs_r, ppd, ppd->visited);
return NULL_TREE;
}
case RECORD_TYPE:
if (TYPE_PTRMEMFUNC_P (t))
return NULL_TREE;
/* Fall through. */
case UNION_TYPE:
case ENUMERAL_TYPE:
if (TYPE_TEMPLATE_INFO (t))
cp_walk_tree (&TYPE_TI_ARGS (t),
&find_parameter_packs_r, ppd, ppd->visited);
*walk_subtrees = 0;
return NULL_TREE;
case TEMPLATE_DECL:
if (!DECL_TEMPLATE_TEMPLATE_PARM_P (t))
return NULL_TREE;
gcc_fallthrough();
case CONSTRUCTOR:
cp_walk_tree (&TREE_TYPE (t),
&find_parameter_packs_r, ppd, ppd->visited);
return NULL_TREE;
case TYPENAME_TYPE:
cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
ppd, ppd->visited);
*walk_subtrees = 0;
return NULL_TREE;
case TYPE_PACK_EXPANSION:
case EXPR_PACK_EXPANSION:
*walk_subtrees = 0;
return NULL_TREE;
case INTEGER_TYPE:
cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
ppd, ppd->visited);
*walk_subtrees = 0;
return NULL_TREE;
case IDENTIFIER_NODE:
cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
ppd->visited);
*walk_subtrees = 0;
return NULL_TREE;
case LAMBDA_EXPR:
{
/* Look at explicit captures. */
for (tree cap = LAMBDA_EXPR_CAPTURE_LIST (t);
cap; cap = TREE_CHAIN (cap))
cp_walk_tree (&TREE_VALUE (cap), &find_parameter_packs_r, ppd,
ppd->visited);
/* Since we defer implicit capture, look in the parms and body. */
tree fn = lambda_function (t);
cp_walk_tree (&TREE_TYPE (fn), &find_parameter_packs_r, ppd,
ppd->visited);
cp_walk_tree (&DECL_SAVED_TREE (fn), &find_parameter_packs_r, ppd,
ppd->visited);
*walk_subtrees = 0;
return NULL_TREE;
}
case DECLTYPE_TYPE:
{
/* When traversing a DECLTYPE_TYPE_EXPR, we need to set
type_pack_expansion_p to false so that any placeholders
within the expression don't get marked as parameter packs. */
bool type_pack_expansion_p = ppd->type_pack_expansion_p;
ppd->type_pack_expansion_p = false;
cp_walk_tree (&DECLTYPE_TYPE_EXPR (t), &find_parameter_packs_r,
ppd, ppd->visited);
ppd->type_pack_expansion_p = type_pack_expansion_p;
*walk_subtrees = 0;
return NULL_TREE;
}
case IF_STMT:
cp_walk_tree (&IF_COND (t), &find_parameter_packs_r,
ppd, ppd->visited);
cp_walk_tree (&THEN_CLAUSE (t), &find_parameter_packs_r,
ppd, ppd->visited);
cp_walk_tree (&ELSE_CLAUSE (t), &find_parameter_packs_r,
ppd, ppd->visited);
/* Don't walk into IF_STMT_EXTRA_ARGS. */
*walk_subtrees = 0;
return NULL_TREE;
default:
return NULL_TREE;
}
return NULL_TREE;
}
/* Determines if the expression or type T uses any parameter packs. */
tree
uses_parameter_packs (tree t)
{
tree parameter_packs = NULL_TREE;
struct find_parameter_pack_data ppd;
ppd.parameter_packs = &parameter_packs;
ppd.visited = new hash_set<tree>;
ppd.type_pack_expansion_p = false;
cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
delete ppd.visited;
return parameter_packs;
}
/* Turn ARG, which may be an expression, type, or a TREE_LIST
representation a base-class initializer into a parameter pack
expansion. If all goes well, the resulting node will be an
EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
respectively. */
tree
make_pack_expansion (tree arg, tsubst_flags_t complain)
{
tree result;
tree parameter_packs = NULL_TREE;
bool for_types = false;
struct find_parameter_pack_data ppd;
if (!arg || arg == error_mark_node)
return arg;
if (TREE_CODE (arg) == TREE_LIST && TREE_PURPOSE (arg))
{
/* A TREE_LIST with a non-null TREE_PURPOSE is for a base
class initializer. In this case, the TREE_PURPOSE will be a
_TYPE node (representing the base class expansion we're
initializing) and the TREE_VALUE will be a TREE_LIST
containing the initialization arguments.
The resulting expansion looks somewhat different from most
expansions. Rather than returning just one _EXPANSION, we
return a TREE_LIST whose TREE_PURPOSE is a
TYPE_PACK_EXPANSION containing the bases that will be
initialized. The TREE_VALUE will be identical to the
original TREE_VALUE, which is a list of arguments that will
be passed to each base. We do not introduce any new pack
expansion nodes into the TREE_VALUE (although it is possible
that some already exist), because the TREE_PURPOSE and
TREE_VALUE all need to be expanded together with the same
_EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
resulting TREE_PURPOSE will mention the parameter packs in
both the bases and the arguments to the bases. */
tree purpose;
tree value;
tree parameter_packs = NULL_TREE;
/* Determine which parameter packs will be used by the base
class expansion. */
ppd.visited = new hash_set<tree>;
ppd.parameter_packs = &parameter_packs;
ppd.type_pack_expansion_p = false;
gcc_assert (TYPE_P (TREE_PURPOSE (arg)));
cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
&ppd, ppd.visited);
if (parameter_packs == NULL_TREE)
{
if (complain & tf_error)
error ("base initializer expansion %qT contains no parameter packs",
arg);
delete ppd.visited;
return error_mark_node;
}
if (TREE_VALUE (arg) != void_type_node)
{
/* Collect the sets of parameter packs used in each of the
initialization arguments. */
for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
{
/* Determine which parameter packs will be expanded in this
argument. */
cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
&ppd, ppd.visited);
}
}
delete ppd.visited;
/* Create the pack expansion type for the base type. */
purpose = cxx_make_type (TYPE_PACK_EXPANSION);
SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
PACK_EXPANSION_LOCAL_P (purpose) = at_function_scope_p ();
/* Just use structural equality for these TYPE_PACK_EXPANSIONS;
they will rarely be compared to anything. */
SET_TYPE_STRUCTURAL_EQUALITY (purpose);
return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
}
if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
for_types = true;
/* Build the PACK_EXPANSION_* node. */
result = for_types
? cxx_make_type (TYPE_PACK_EXPANSION)
: make_node (EXPR_PACK_EXPANSION);
SET_PACK_EXPANSION_PATTERN (result, arg);
if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
{
/* Propagate type and const-expression information. */
TREE_TYPE (result) = TREE_TYPE (arg);
TREE_CONSTANT (result) = TREE_CONSTANT (arg);
/* Mark this read now, since the expansion might be length 0. */
mark_exp_read (arg);
}
else
/* Just use structural equality for these TYPE_PACK_EXPANSIONS;
they will rarely be compared to anything. */
SET_TYPE_STRUCTURAL_EQUALITY (result);
/* Determine which parameter packs will be expanded. */
ppd.parameter_packs = &parameter_packs;
ppd.visited = new hash_set<tree>;
ppd.type_pack_expansion_p = TYPE_P (arg);
cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
delete ppd.visited;
/* Make sure we found some parameter packs. */
if (parameter_packs == NULL_TREE)
{
if (complain & tf_error)
{
if (TYPE_P (arg))
error ("expansion pattern %qT contains no parameter packs", arg);
else
error ("expansion pattern %qE contains no parameter packs", arg);
}
return error_mark_node;
}
PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
PACK_EXPANSION_LOCAL_P (result) = at_function_scope_p ();
return result;
}
/* Checks T for any "bare" parameter packs, which have not yet been
expanded, and issues an error if any are found. This operation can
only be done on full expressions or types (e.g., an expression
statement, "if" condition, etc.), because we could have expressions like:
foo(f(g(h(args)))...)
where "args" is a parameter pack. check_for_bare_parameter_packs
should not be called for the subexpressions args, h(args),
g(h(args)), or f(g(h(args))), because we would produce erroneous
error messages.
Returns TRUE and emits an error if there were bare parameter packs,
returns FALSE otherwise. */
bool
check_for_bare_parameter_packs (tree t, location_t loc /* = UNKNOWN_LOCATION */)
{
tree parameter_packs = NULL_TREE;
struct find_parameter_pack_data ppd;
if (!processing_template_decl || !t || t == error_mark_node)
return false;
/* A lambda might use a parameter pack from the containing context. */
if (current_class_type && LAMBDA_TYPE_P (current_class_type)
&& CLASSTYPE_TEMPLATE_INFO (current_class_type))
return false;
if (TREE_CODE (t) == TYPE_DECL)
t = TREE_TYPE (t);
ppd.parameter_packs = &parameter_packs;
ppd.visited = new hash_set<tree>;
ppd.type_pack_expansion_p = false;
cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
delete ppd.visited;
if (parameter_packs)
{
if (loc == UNKNOWN_LOCATION)
loc = cp_expr_loc_or_loc (t, input_location);
error_at (loc, "parameter packs not expanded with %<...%>:");
while (parameter_packs)
{
tree pack = TREE_VALUE (parameter_packs);
tree name = NULL_TREE;
if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
|| TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
name = TYPE_NAME (pack);
else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
else if (TREE_CODE (pack) == CALL_EXPR)
name = DECL_NAME (CALL_EXPR_FN (pack));
else
name = DECL_NAME (pack);
if (name)
inform (loc, " %qD", name);
else
inform (loc, " <anonymous>");
parameter_packs = TREE_CHAIN (parameter_packs);
}
return true;
}
return false;
}
/* Expand any parameter packs that occur in the template arguments in
ARGS. */
tree
expand_template_argument_pack (tree args)
{
if (args == error_mark_node)
return error_mark_node;
tree result_args = NULL_TREE;
int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
int num_result_args = -1;
int non_default_args_count = -1;
/* First, determine if we need to expand anything, and the number of
slots we'll need. */
for (in_arg = 0; in_arg < nargs; ++in_arg)
{
tree arg = TREE_VEC_ELT (args, in_arg);
if (arg == NULL_TREE)
return args;
if (ARGUMENT_PACK_P (arg))
{
int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
if (num_result_args < 0)
num_result_args = in_arg + num_packed;
else
num_result_args += num_packed;
}
else
{
if (num_result_args >= 0)
num_result_args++;
}
}
/* If no expansion is necessary, we're done. */
if (num_result_args < 0)
return args;
/* Expand arguments. */
result_args = make_tree_vec (num_result_args);
if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
non_default_args_count =
GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
for (in_arg = 0; in_arg < nargs; ++in_arg)
{
tree arg = TREE_VEC_ELT (args, in_arg);
if (ARGUMENT_PACK_P (arg))
{
tree packed = ARGUMENT_PACK_ARGS (arg);
int i, num_packed = TREE_VEC_LENGTH (packed);
for (i = 0; i < num_packed; ++i, ++out_arg)
TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
if (non_default_args_count > 0)
non_default_args_count += num_packed - 1;
}
else
{
TREE_VEC_ELT (result_args, out_arg) = arg;
++out_arg;
}
}
if (non_default_args_count >= 0)
SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
return result_args;
}
/* Checks if DECL shadows a template parameter.
[temp.local]: A template-parameter shall not be redeclared within its
scope (including nested scopes).
Emits an error and returns TRUE if the DECL shadows a parameter,
returns FALSE otherwise. */
bool
check_template_shadow (tree decl)
{
tree olddecl;
/* If we're not in a template, we can't possibly shadow a template
parameter. */
if (!current_template_parms)
return true;
/* Figure out what we're shadowing. */
decl = OVL_FIRST (decl);
olddecl = innermost_non_namespace_value (DECL_NAME (decl));
/* If there's no previous binding for this name, we're not shadowing
anything, let alone a template parameter. */
if (!olddecl)
return true;
/* If we're not shadowing a template parameter, we're done. Note
that OLDDECL might be an OVERLOAD (or perhaps even an
ERROR_MARK), so we can't just blithely assume it to be a _DECL
node. */
if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
return true;
/* We check for decl != olddecl to avoid bogus errors for using a
name inside a class. We check TPFI to avoid duplicate errors for
inline member templates. */
if (decl == olddecl
|| (DECL_TEMPLATE_PARM_P (decl)
&& TEMPLATE_PARMS_FOR_INLINE (current_template_parms)))
return true;
/* Don't complain about the injected class name, as we've already
complained about the class itself. */
if (DECL_SELF_REFERENCE_P (decl))
return false;
if (DECL_TEMPLATE_PARM_P (decl))
error ("declaration of template parameter %q+D shadows "
"template parameter", decl);
else
error ("declaration of %q+#D shadows template parameter", decl);
inform (DECL_SOURCE_LOCATION (olddecl),
"template parameter %qD declared here", olddecl);
return false;
}
/* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
ORIG_LEVEL, DECL, and TYPE. */
static tree
build_template_parm_index (int index,
int level,
int orig_level,
tree decl,
tree type)
{
tree t = make_node (TEMPLATE_PARM_INDEX);
TEMPLATE_PARM_IDX (t) = index;
TEMPLATE_PARM_LEVEL (t) = level;
TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
TEMPLATE_PARM_DECL (t) = decl;
TREE_TYPE (t) = type;
TREE_CONSTANT (t) = TREE_CONSTANT (decl);
TREE_READONLY (t) = TREE_READONLY (decl);
return t;
}
/* Find the canonical type parameter for the given template type
parameter. Returns the canonical type parameter, which may be TYPE
if no such parameter existed. */
static tree
canonical_type_parameter (tree type)
{
tree list;
int idx = TEMPLATE_TYPE_IDX (type);
if (!canonical_template_parms)
vec_alloc (canonical_template_parms, idx + 1);
if (canonical_template_parms->length () <= (unsigned) idx)
vec_safe_grow_cleared (canonical_template_parms, idx + 1);
list = (*canonical_template_parms)[idx];
while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
list = TREE_CHAIN (list);
if (list)
return TREE_VALUE (list);
else
{
(*canonical_template_parms)[idx]
= tree_cons (NULL_TREE, type, (*canonical_template_parms)[idx]);
return type;
}
}
/* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
new one is created. */
static tree
reduce_template_parm_level (tree index, tree type, int levels, tree args,
tsubst_flags_t complain)
{
if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
|| (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
!= TEMPLATE_PARM_LEVEL (index) - levels)
|| !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
{
tree orig_decl = TEMPLATE_PARM_DECL (index);
tree decl, t;
decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
TREE_READONLY (decl) = TREE_READONLY (orig_decl);
DECL_ARTIFICIAL (decl) = 1;
SET_DECL_TEMPLATE_PARM_P (decl);
t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
TEMPLATE_PARM_LEVEL (index) - levels,
TEMPLATE_PARM_ORIG_LEVEL (index),
decl, type);
TEMPLATE_PARM_DESCENDANTS (index) = t;
TEMPLATE_PARM_PARAMETER_PACK (t)
= TEMPLATE_PARM_PARAMETER_PACK (index);
/* Template template parameters need this. */
if (TREE_CODE (decl) == TEMPLATE_DECL)
{
DECL_TEMPLATE_RESULT (decl)
= build_decl (DECL_SOURCE_LOCATION (decl),
TYPE_DECL, DECL_NAME (decl), type);
DECL_ARTIFICIAL (DECL_TEMPLATE_RESULT (decl)) = true;
DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
(DECL_TEMPLATE_PARMS (orig_decl), args, complain);
}
}
return TEMPLATE_PARM_DESCENDANTS (index);
}
/* Process information from new template parameter PARM and append it
to the LIST being built. This new parameter is a non-type
parameter iff IS_NON_TYPE is true. This new parameter is a
parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
is in PARM_LOC. */
tree
process_template_parm (tree list, location_t parm_loc, tree parm,
bool is_non_type, bool is_parameter_pack)
{
tree decl = 0;
int idx = 0;
gcc_assert (TREE_CODE (parm) == TREE_LIST);
tree defval = TREE_PURPOSE (parm);
tree constr = TREE_TYPE (parm);
if (list)
{
tree p = tree_last (list);
if (p && TREE_VALUE (p) != error_mark_node)
{
p = TREE_VALUE (p);
if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
else
idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
}
++idx;
}
if (is_non_type)
{
parm = TREE_VALUE (parm);
SET_DECL_TEMPLATE_PARM_P (parm);
if (TREE_TYPE (parm) != error_mark_node)
{
/* [temp.param]
The top-level cv-qualifiers on the template-parameter are
ignored when determining its type. */
TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
TREE_TYPE (parm) = error_mark_node;
else if (uses_parameter_packs (TREE_TYPE (parm))
&& !is_parameter_pack
/* If we're in a nested template parameter list, the template
template parameter could be a parameter pack. */
&& processing_template_parmlist == 1)
{
/* This template parameter is not a parameter pack, but it
should be. Complain about "bare" parameter packs. */
check_for_bare_parameter_packs (TREE_TYPE (parm));
/* Recover by calling this a parameter pack. */
is_parameter_pack = true;
}
}
/* A template parameter is not modifiable. */
TREE_CONSTANT (parm) = 1;
TREE_READONLY (parm) = 1;
decl = build_decl (parm_loc,
CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
TREE_CONSTANT (decl) = 1;
TREE_READONLY (decl) = 1;
DECL_INITIAL (parm) = DECL_INITIAL (decl)
= build_template_parm_index (idx, processing_template_decl,
processing_template_decl,
decl, TREE_TYPE (parm));
TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
= is_parameter_pack;
}
else
{
tree t;
parm = TREE_VALUE (TREE_VALUE (parm));
if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
{
t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
/* This is for distinguishing between real templates and template
template parameters */
TREE_TYPE (parm) = t;
TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
decl = parm;
}
else
{
t = cxx_make_type (TEMPLATE_TYPE_PARM);
/* parm is either IDENTIFIER_NODE or NULL_TREE. */
decl = build_decl (parm_loc,
TYPE_DECL, parm, t);
}
TYPE_NAME (t) = decl;
TYPE_STUB_DECL (t) = decl;
parm = decl;
TEMPLATE_TYPE_PARM_INDEX (t)
= build_template_parm_index (idx, processing_template_decl,
processing_template_decl,
decl, TREE_TYPE (parm));
TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
TYPE_CANONICAL (t) = canonical_type_parameter (t);
}
DECL_ARTIFICIAL (decl) = 1;
SET_DECL_TEMPLATE_PARM_P (decl);
/* Build requirements for the type/template parameter.
This must be done after SET_DECL_TEMPLATE_PARM_P or
process_template_parm could fail. */
tree reqs = finish_shorthand_constraint (parm, constr);
decl = pushdecl (decl);
if (!is_non_type)
parm = decl;
/* Build the parameter node linking the parameter declaration,
its default argument (if any), and its constraints (if any). */
parm = build_tree_list (defval, parm);
TEMPLATE_PARM_CONSTRAINTS (parm) = reqs;
return chainon (list, parm);
}
/* The end of a template parameter list has been reached. Process the
tree list into a parameter vector, converting each parameter into a more
useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
as PARM_DECLs. */
tree
end_template_parm_list (tree parms)
{
int nparms;
tree parm, next;
tree saved_parmlist = make_tree_vec (list_length (parms));
/* Pop the dummy parameter level and add the real one. */
current_template_parms = TREE_CHAIN (current_template_parms);
current_template_parms
= tree_cons (size_int (processing_template_decl),
saved_parmlist, current_template_parms);
for (parm = parms, nparms = 0; parm; parm = next, nparms++)
{
next = TREE_CHAIN (parm);
TREE_VEC_ELT (saved_parmlist, nparms) = parm;
TREE_CHAIN (parm) = NULL_TREE;
}
--processing_template_parmlist;
return saved_parmlist;
}
// Explicitly indicate the end of the template parameter list. We assume
// that the current template parameters have been constructed and/or
// managed explicitly, as when creating new template template parameters
// from a shorthand constraint.
void
end_template_parm_list ()
{
--processing_template_parmlist;
}
/* end_template_decl is called after a template declaration is seen. */
void
end_template_decl (void)
{
reset_specialization ();
if (! processing_template_decl)
return;
/* This matches the pushlevel in begin_template_parm_list. */
finish_scope ();
--processing_template_decl;
current_template_parms = TREE_CHAIN (current_template_parms);
}
/* Takes a TREE_LIST representing a template parameter and convert it
into an argument suitable to be passed to the type substitution
functions. Note that If the TREE_LIST contains an error_mark
node, the returned argument is error_mark_node. */
tree
template_parm_to_arg (tree t)
{
if (t == NULL_TREE
|| TREE_CODE (t) != TREE_LIST)
return t;
if (error_operand_p (TREE_VALUE (t)))
return error_mark_node;
t = TREE_VALUE (t);
if (TREE_CODE (t) == TYPE_DECL
|| TREE_CODE (t) == TEMPLATE_DECL)
{
t = TREE_TYPE (t);
if (TEMPLATE_TYPE_PARAMETER_PACK (t))
{
/* Turn this argument into a TYPE_ARGUMENT_PACK
with a single element, which expands T. */
tree vec = make_tree_vec (1);
if (CHECKING_P)
SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (vec, TREE_VEC_LENGTH (vec));
TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
t = cxx_make_type (TYPE_ARGUMENT_PACK);
SET_ARGUMENT_PACK_ARGS (t, vec);
}
}
else
{
t = DECL_INITIAL (t);
if (TEMPLATE_PARM_PARAMETER_PACK (t))
{
/* Turn this argument into a NONTYPE_ARGUMENT_PACK
with a single element, which expands T. */
tree vec = make_tree_vec (1);
if (CHECKING_P)
SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (vec, TREE_VEC_LENGTH (vec));
t = convert_from_reference (t);
TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
t = make_node (NONTYPE_ARGUMENT_PACK);
SET_ARGUMENT_PACK_ARGS (t, vec);
}
else
t = convert_from_reference (t);
}
return t;
}
/* Given a single level of template parameters (a TREE_VEC), return it
as a set of template arguments. */
static tree
template_parms_level_to_args (tree parms)
{
tree a = copy_node (parms);
TREE_TYPE (a) = NULL_TREE;
for (int i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
if (CHECKING_P)
SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
return a;
}
/* Given a set of template parameters, return them as a set of template
arguments. The template parameters are represented as a TREE_VEC, in
the form documented in cp-tree.h for template arguments. */
static tree
template_parms_to_args (tree parms)
{
tree header;
tree args = NULL_TREE;
int length = TMPL_PARMS_DEPTH (parms);
int l = length;
/* If there is only one level of template parameters, we do not
create a TREE_VEC of TREE_VECs. Instead, we return a single
TREE_VEC containing the arguments. */
if (length > 1)
args = make_tree_vec (length);
for (header = parms; header; header = TREE_CHAIN (header))
{
tree a = template_parms_level_to_args (TREE_VALUE (header));
if (length > 1)
TREE_VEC_ELT (args, --l) = a;
else
args = a;
}
return args;
}
/* Within the declaration of a template, return the currently active
template parameters as an argument TREE_VEC. */
static tree
current_template_args (void)
{
return template_parms_to_args (current_template_parms);
}
/* Update the declared TYPE by doing any lookups which were thought to be
dependent, but are not now that we know the SCOPE of the declarator. */
tree
maybe_update_decl_type (tree orig_type, tree scope)
{
tree type = orig_type;
if (type == NULL_TREE)
return type;
if (TREE_CODE (orig_type) == TYPE_DECL)
type = TREE_TYPE (type);
if (scope && TYPE_P (scope) && dependent_type_p (scope)
&& dependent_type_p (type)
/* Don't bother building up the args in this case. */
&& TREE_CODE (type) != TEMPLATE_TYPE_PARM)
{
/* tsubst in the args corresponding to the template parameters,
including auto if present. Most things will be unchanged, but
make_typename_type and tsubst_qualified_id will resolve
TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
tree args = current_template_args ();
tree auto_node = type_uses_auto (type);
tree pushed;
if (auto_node)
{
tree auto_vec = make_tree_vec (1);
TREE_VEC_ELT (auto_vec, 0) = auto_node;
args = add_to_template_args (args, auto_vec);
}
pushed = push_scope (scope);
type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
if (pushed)
pop_scope (scope);
}
if (type == error_mark_node)
return orig_type;
if (TREE_CODE (orig_type) == TYPE_DECL)
{
if (same_type_p (type, TREE_TYPE (orig_type)))
type = orig_type;
else
type = TYPE_NAME (type);
}
return type;
}
/* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
the new template is a member template. */
static tree
build_template_decl (tree decl, tree parms, bool member_template_p)
{
tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
SET_DECL_LANGUAGE (tmpl, DECL_LANGUAGE (decl));
DECL_TEMPLATE_PARMS (tmpl) = parms;
DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
return tmpl;
}
struct template_parm_data
{
/* The level of the template parameters we are currently
processing. */
int level;
/* The index of the specialization argument we are currently
processing. */
int current_arg;
/* An array whose size is the number of template parameters. The
elements are nonzero if the parameter has been used in any one
of the arguments processed so far. */
int* parms;
/* An array whose size is the number of template arguments. The
elements are nonzero if the argument makes use of template
parameters of this level. */
int* arg_uses_template_parms;
};
/* Subroutine of push_template_decl used to see if each template
parameter in a partial specialization is used in the explicit
argument list. If T is of the LEVEL given in DATA (which is
treated as a template_parm_data*), then DATA->PARMS is marked
appropriately. */
static int
mark_template_parm (tree t, void* data)
{
int level;
int idx;
struct template_parm_data* tpd = (struct template_parm_data*) data;
template_parm_level_and_index (t, &level, &idx);
if (level == tpd->level)
{
tpd->parms[idx] = 1;
tpd->arg_uses_template_parms[tpd->current_arg] = 1;
}
/* In C++17 the type of a non-type argument is a deduced context. */
if (cxx_dialect >= cxx17
&& TREE_CODE (t) == TEMPLATE_PARM_INDEX)
for_each_template_parm (TREE_TYPE (t),
&mark_template_parm,
data,
NULL,
/*include_nondeduced_p=*/false);
/* Return zero so that for_each_template_parm will continue the
traversal of the tree; we want to mark *every* template parm. */
return 0;
}
/* Process the partial specialization DECL. */
static tree
process_partial_specialization (tree decl)
{
tree type = TREE_TYPE (decl);
tree tinfo = get_template_info (decl);
tree maintmpl = TI_TEMPLATE (tinfo);
tree specargs = TI_ARGS (tinfo);
tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
tree inner_parms;
tree inst;
int nargs = TREE_VEC_LENGTH (inner_args);
int ntparms;
int i;
bool did_error_intro = false;
struct template_parm_data tpd;
struct template_parm_data tpd2;
gcc_assert (current_template_parms);
/* A concept cannot be specialized. */
if (flag_concepts && variable_concept_p (maintmpl))
{
error ("specialization of variable concept %q#D", maintmpl);
return error_mark_node;
}
inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
ntparms = TREE_VEC_LENGTH (inner_parms);
/* We check that each of the template parameters given in the
partial specialization is used in the argument list to the
specialization. For example:
template <class T> struct S;
template <class T> struct S<T*>;
The second declaration is OK because `T*' uses the template
parameter T, whereas
template <class T> struct S<int>;
is no good. Even trickier is:
template <class T>
struct S1
{
template <class U>
struct S2;
template <class U>
struct S2<T>;
};
The S2<T> declaration is actually invalid; it is a
full-specialization. Of course,
template <class U>
struct S2<T (*)(U)>;
or some such would have been OK. */
tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
tpd.parms = XALLOCAVEC (int, ntparms);
memset (tpd.parms, 0, sizeof (int) * ntparms);
tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
for (i = 0; i < nargs; ++i)
{
tpd.current_arg = i;
for_each_template_parm (TREE_VEC_ELT (inner_args, i),
&mark_template_parm,
&tpd,
NULL,
/*include_nondeduced_p=*/false);
}
for (i = 0; i < ntparms; ++i)
if (tpd.parms[i] == 0)
{
/* One of the template parms was not used in a deduced context in the
specialization. */
if (!did_error_intro)
{
error ("template parameters not deducible in "
"partial specialization:");
did_error_intro = true;
}
inform (input_location, " %qD",
TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
}
if (did_error_intro)
return error_mark_node;
/* [temp.class.spec]
The argument list of the specialization shall not be identical to
the implicit argument list of the primary template. */
tree main_args
= TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (maintmpl)));
if (comp_template_args (inner_args, INNERMOST_TEMPLATE_ARGS (main_args))
&& (!flag_concepts
|| !strictly_subsumes (current_template_constraints (),
get_constraints (maintmpl))))
{
if (!flag_concepts)
error ("partial specialization %q+D does not specialize "
"any template arguments; to define the primary template, "
"remove the template argument list", decl);
else
error ("partial specialization %q+D does not specialize any "
"template arguments and is not more constrained than "
"the primary template; to define the primary template, "
"remove the template argument list", decl);
inform (DECL_SOURCE_LOCATION (maintmpl), "primary template here");
}
/* A partial specialization that replaces multiple parameters of the
primary template with a pack expansion is less specialized for those
parameters. */
if (nargs < DECL_NTPARMS (maintmpl))
{
error ("partial specialization is not more specialized than the "
"primary template because it replaces multiple parameters "
"with a pack expansion");
inform (DECL_SOURCE_LOCATION (maintmpl), "primary template here");
/* Avoid crash in process_partial_specialization. */
return decl;
}
else if (nargs > DECL_NTPARMS (maintmpl))
{
error ("too many arguments for partial specialization %qT", type);
inform (DECL_SOURCE_LOCATION (maintmpl), "primary template here");
/* Avoid crash below. */
return decl;
}
/* If we aren't in a dependent class, we can actually try deduction. */
else if (tpd.level == 1
/* FIXME we should be able to handle a partial specialization of a
partial instantiation, but currently we can't (c++/41727). */
&& TMPL_ARGS_DEPTH (specargs) == 1
&& !get_partial_spec_bindings (maintmpl, maintmpl, specargs))
{
auto_diagnostic_group d;
if (permerror (input_location, "partial specialization %qD is not "
"more specialized than", decl))
inform (DECL_SOURCE_LOCATION (maintmpl), "primary template %qD",
maintmpl);
}
/* [temp.class.spec]
A partially specialized non-type argument expression shall not
involve template parameters of the partial specialization except
when the argument expression is a simple identifier.
The type of a template parameter corresponding to a specialized
non-type argument shall not be dependent on a parameter of the
specialization.
Also, we verify that pack expansions only occur at the
end of the argument list. */
tpd2.parms = 0;
for (i = 0; i < nargs; ++i)
{
tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
tree arg = TREE_VEC_ELT (inner_args, i);
tree packed_args = NULL_TREE;
int j, len = 1;
if (ARGUMENT_PACK_P (arg))
{
/* Extract the arguments from the argument pack. We'll be
iterating over these in the following loop. */
packed_args = ARGUMENT_PACK_ARGS (arg);
len = TREE_VEC_LENGTH (packed_args);
}
for (j = 0; j < len; j++)
{
if (packed_args)
/* Get the Jth argument in the parameter pack. */
arg = TREE_VEC_ELT (packed_args, j);
if (PACK_EXPANSION_P (arg))
{
/* Pack expansions must come at the end of the
argument list. */
if ((packed_args && j < len - 1)
|| (!packed_args && i < nargs - 1))
{
if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
error ("parameter pack argument %qE must be at the "
"end of the template argument list", arg);
else
error ("parameter pack argument %qT must be at the "
"end of the template argument list", arg);
}
}
if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
/* We only care about the pattern. */
arg = PACK_EXPANSION_PATTERN (arg);
if (/* These first two lines are the `non-type' bit. */
!TYPE_P (arg)
&& TREE_CODE (arg) != TEMPLATE_DECL
/* This next two lines are the `argument expression is not just a
simple identifier' condition and also the `specialized
non-type argument' bit. */
&& TREE_CODE (arg) != TEMPLATE_PARM_INDEX
&& !((REFERENCE_REF_P (arg)
|| TREE_CODE (arg) == VIEW_CONVERT_EXPR)
&& TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_PARM_INDEX))
{
if ((!packed_args && tpd.arg_uses_template_parms[i])
|| (packed_args && uses_template_parms (arg)))
error ("template argument %qE involves template parameter(s)",
arg);
else
{
/* Look at the corresponding template parameter,
marking which template parameters its type depends
upon. */
tree type = TREE_TYPE (parm);
if (!tpd2.parms)
{
/* We haven't yet initialized TPD2. Do so now. */
tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
/* The number of parameters here is the number in the
main template, which, as checked in the assertion
above, is NARGS. */
tpd2.parms = XALLOCAVEC (int, nargs);
tpd2.level =
TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
}
/* Mark the template parameters. But this time, we're
looking for the template parameters of the main
template, not in the specialization. */
tpd2.current_arg = i;
tpd2.arg_uses_template_parms[i] = 0;
memset (tpd2.parms, 0, sizeof (int) * nargs);
for_each_template_parm (type,
&mark_template_parm,
&tpd2,
NULL,
/*include_nondeduced_p=*/false);
if (tpd2.arg_uses_template_parms [i])
{
/* The type depended on some template parameters.
If they are fully specialized in the
specialization, that's OK. */
int j;
int count = 0;
for (j = 0; j < nargs; ++j)
if (tpd2.parms[j] != 0
&& tpd.arg_uses_template_parms [j])
++count;
if (count != 0)
error_n (input_location, count,
"type %qT of template argument %qE depends "
"on a template parameter",
"type %qT of template argument %qE depends "
"on template parameters",
type,
arg);
}
}
}
}
}
/* We should only get here once. */
if (TREE_CODE (decl) == TYPE_DECL)
gcc_assert (!COMPLETE_TYPE_P (type));
// Build the template decl.
tree tmpl = build_template_decl (decl, current_template_parms,
DECL_MEMBER_TEMPLATE_P (maintmpl));
TREE_TYPE (tmpl) = type;
DECL_TEMPLATE_RESULT (tmpl) = decl;
SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
DECL_TEMPLATE_INFO (tmpl) = build_template_info (maintmpl, specargs);
DECL_PRIMARY_TEMPLATE (tmpl) = maintmpl;
/* Give template template parms a DECL_CONTEXT of the template
for which they are a parameter. */
for (i = 0; i < ntparms; ++i)
{
tree parm = TREE_VALUE (TREE_VEC_ELT (inner_parms, i));
if (TREE_CODE (parm) == TEMPLATE_DECL)
DECL_CONTEXT (parm) = tmpl;
}
if (VAR_P (decl))
/* We didn't register this in check_explicit_specialization so we could
wait until the constraints were set. */
decl = register_specialization (decl, maintmpl, specargs, false, 0);
else
associate_classtype_constraints (type);
DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
= tree_cons (specargs, tmpl,
DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
inst = TREE_CHAIN (inst))
{
tree instance = TREE_VALUE (inst);
if (TYPE_P (instance)
? (COMPLETE_TYPE_P (instance)
&& CLASSTYPE_IMPLICIT_INSTANTIATION (instance))
: DECL_TEMPLATE_INSTANTIATION (instance))
{
tree spec = most_specialized_partial_spec (instance, tf_none);
tree inst_decl = (DECL_P (instance)
? instance : TYPE_NAME (instance));
if (!spec)
/* OK */;
else if (spec == error_mark_node)
permerror (input_location,
"declaration of %qD ambiguates earlier template "
"instantiation for %qD", decl, inst_decl);
else if (TREE_VALUE (spec) == tmpl)
permerror (input_location,
"partial specialization of %qD after instantiation "
"of %qD", decl, inst_decl);
}
}
return decl;
}
/* PARM is a template parameter of some form; return the corresponding
TEMPLATE_PARM_INDEX. */
static tree
get_template_parm_index (tree parm)
{
if (TREE_CODE (parm) == PARM_DECL
|| TREE_CODE (parm) == CONST_DECL)
parm = DECL_INITIAL (parm);
else if (TREE_CODE (parm) == TYPE_DECL
|| TREE_CODE (parm) == TEMPLATE_DECL)
parm = TREE_TYPE (parm);
if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
|| TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM
|| TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
parm = TEMPLATE_TYPE_PARM_INDEX (parm);
gcc_assert (TREE_CODE (parm) == TEMPLATE_PARM_INDEX);
return parm;
}
/* Subroutine of fixed_parameter_pack_p below. Look for any template
parameter packs used by the template parameter PARM. */
static void
fixed_parameter_pack_p_1 (tree parm, struct find_parameter_pack_data *ppd)
{
/* A type parm can't refer to another parm. */
if (TREE_CODE (parm) == TYPE_DECL || parm == error_mark_node)
return;
else if (TREE_CODE (parm) == PARM_DECL)
{
cp_walk_tree (&TREE_TYPE (parm), &find_parameter_packs_r,
ppd, ppd->visited);
return;
}
gcc_assert (TREE_CODE (parm) == TEMPLATE_DECL);
tree vec = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
for (int i = 0; i < TREE_VEC_LENGTH (vec); ++i)
{
tree p = TREE_VALUE (TREE_VEC_ELT (vec, i));
if (template_parameter_pack_p (p))
/* Any packs in the type are expanded by this parameter. */;
else
fixed_parameter_pack_p_1 (p, ppd);
}
}
/* PARM is a template parameter pack. Return any parameter packs used in
its type or the type of any of its template parameters. If there are
any such packs, it will be instantiated into a fixed template parameter
list by partial instantiation rather than be fully deduced. */
tree
fixed_parameter_pack_p (tree parm)
{
/* This can only be true in a member template. */
if (TEMPLATE_PARM_ORIG_LEVEL (get_template_parm_index (parm)) < 2)
return NULL_TREE;
/* This can only be true for a parameter pack. */
if (!template_parameter_pack_p (parm))
return NULL_TREE;
/* A type parm can't refer to another parm. */
if (TREE_CODE (parm) == TYPE_DECL)
return NULL_TREE;
tree parameter_packs = NULL_TREE;
struct find_parameter_pack_data ppd;
ppd.parameter_packs = &parameter_packs;
ppd.visited = new hash_set<tree>;
ppd.type_pack_expansion_p = false;
fixed_parameter_pack_p_1 (parm, &ppd);
delete ppd.visited;
return parameter_packs;
}
/* Check that a template declaration's use of default arguments and
parameter packs is not invalid. Here, PARMS are the template
parameters. IS_PRIMARY is true if DECL is the thing declared by
a primary template. IS_PARTIAL is true if DECL is a partial
specialization.
IS_FRIEND_DECL is nonzero if DECL is either a non-defining friend
function template declaration or a friend class template
declaration. In the function case, 1 indicates a declaration, 2
indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
emitted for extraneous default arguments.
Returns TRUE if there were no errors found, FALSE otherwise. */
bool
check_default_tmpl_args (tree decl, tree parms, bool is_primary,
bool is_partial, int is_friend_decl)
{
const char *msg;
int last_level_to_check;
tree parm_level;
bool no_errors = true;
/* [temp.param]
A default template-argument shall not be specified in a
function template declaration or a function template definition, nor
in the template-parameter-list of the definition of a member of a
class template. */
if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL
|| (TREE_CODE (decl) == FUNCTION_DECL && DECL_LOCAL_FUNCTION_P (decl)))
/* You can't have a function template declaration in a local
scope, nor you can you define a member of a class template in a
local scope. */
return true;
if ((TREE_CODE (decl) == TYPE_DECL
&& TREE_TYPE (decl)
&& LAMBDA_TYPE_P (TREE_TYPE (decl)))
|| (TREE_CODE (decl) == FUNCTION_DECL
&& LAMBDA_FUNCTION_P (decl)))
/* A lambda doesn't have an explicit declaration; don't complain
about the parms of the enclosing class. */
return true;
if (current_class_type
&& !TYPE_BEING_DEFINED (current_class_type)
&& DECL_LANG_SPECIFIC (decl)
&& DECL_DECLARES_FUNCTION_P (decl)
/* If this is either a friend defined in the scope of the class
or a member function. */
&& (DECL_FUNCTION_MEMBER_P (decl)
? same_type_p (DECL_CONTEXT (decl), current_class_type)
: DECL_FRIEND_CONTEXT (decl)
? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
: false)
/* And, if it was a member function, it really was defined in
the scope of the class. */
&& (!DECL_FUNCTION_MEMBER_P (decl)
|| DECL_INITIALIZED_IN_CLASS_P (decl)))
/* We already checked these parameters when the template was
declared, so there's no need to do it again now. This function
was defined in class scope, but we're processing its body now
that the class is complete. */
return true;
/* Core issue 226 (C++0x only): the following only applies to class
templates. */
if (is_primary
&& ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL))
{
/* [temp.param]
If a template-parameter has a default template-argument, all
subsequent template-parameters shall have a default
template-argument supplied. */
for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
{
tree inner_parms = TREE_VALUE (parm_level);
int ntparms = TREE_VEC_LENGTH (inner_parms);
int seen_def_arg_p = 0;
int i;
for (i = 0; i < ntparms; ++i)
{
tree parm = TREE_VEC_ELT (inner_parms, i);
if (parm == error_mark_node)
continue;
if (TREE_PURPOSE (parm))
seen_def_arg_p = 1;
else if (seen_def_arg_p
&& !template_parameter_pack_p (TREE_VALUE (parm)))
{
error ("no default argument for %qD", TREE_VALUE (parm));
/* For better subsequent error-recovery, we indicate that
there should have been a default argument. */
TREE_PURPOSE (parm) = error_mark_node;
no_errors = false;
}
else if (!is_partial
&& !is_friend_decl
/* Don't complain about an enclosing partial
specialization. */
&& parm_level == parms
&& TREE_CODE (decl) == TYPE_DECL
&& i < ntparms - 1
&& template_parameter_pack_p (TREE_VALUE (parm))
/* A fixed parameter pack will be partially
instantiated into a fixed length list. */
&& !fixed_parameter_pack_p (TREE_VALUE (parm)))
{
/* A primary class template can only have one
parameter pack, at the end of the template
parameter list. */
error ("parameter pack %q+D must be at the end of the"
" template parameter list", TREE_VALUE (parm));
TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
= error_mark_node;
no_errors = false;
}
}
}
}
if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
|| is_partial
|| !is_primary
|| is_friend_decl)
/* For an ordinary class template, default template arguments are
allowed at the innermost level, e.g.:
template <class T = int>
struct S {};
but, in a partial specialization, they're not allowed even
there, as we have in [temp.class.spec]:
The template parameter list of a specialization shall not
contain default template argument values.
So, for a partial specialization, or for a function template
(in C++98/C++03), we look at all of them. */
;
else
/* But, for a primary class template that is not a partial
specialization we look at all template parameters except the
innermost ones. */
parms = TREE_CHAIN (parms);
/* Figure out what error message to issue. */
if (is_friend_decl == 2)
msg = G_("default template arguments may not be used in function template "
"friend re-declaration");
else if (is_friend_decl)
msg = G_("default template arguments may not be used in template "
"friend declarations");
else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
msg = G_("default template arguments may not be used in function templates "
"without %<-std=c++11%> or %<-std=gnu++11%>");
else if (is_partial)
msg = G_("default template arguments may not be used in "
"partial specializations");
else if (current_class_type && CLASSTYPE_IS_TEMPLATE (current_class_type))
msg = G_("default argument for template parameter for class enclosing %qD");
else
/* Per [temp.param]/9, "A default template-argument shall not be
specified in the template-parameter-lists of the definition of
a member of a class template that appears outside of the member's
class.", thus if we aren't handling a member of a class template
there is no need to examine the parameters. */
return true;
if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
/* If we're inside a class definition, there's no need to
examine the parameters to the class itself. On the one
hand, they will be checked when the class is defined, and,
on the other, default arguments are valid in things like:
template <class T = double>
struct S { template <class U> void f(U); };
Here the default argument for `S' has no bearing on the
declaration of `f'. */
last_level_to_check = template_class_depth (current_class_type) + 1;
else
/* Check everything. */
last_level_to_check = 0;
for (parm_level = parms;
parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
parm_level = TREE_CHAIN (parm_level))
{
tree inner_parms = TREE_VALUE (parm_level);
int i;
int ntparms;
ntparms = TREE_VEC_LENGTH (inner_parms);
for (i = 0; i < ntparms; ++i)
{
if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
continue;
if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
{
if (msg)
{
no_errors = false;
if (is_friend_decl == 2)
return no_errors;
error (msg, decl);
msg = 0;
}
/* Clear out the default argument so that we are not
confused later. */
TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
}
}
/* At this point, if we're still interested in issuing messages,
they must apply to classes surrounding the object declared. */
if (msg)
msg = G_("default argument for template parameter for class "
"enclosing %qD");
}
return no_errors;
}
/* Worker for push_template_decl_real, called via
for_each_template_parm. DATA is really an int, indicating the
level of the parameters we are interested in. If T is a template
parameter of that level, return nonzero. */
static int
template_parm_this_level_p (tree t, void* data)
{
int this_level = *(int *)data;
int level;
if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
level = TEMPLATE_PARM_LEVEL (t);
else
level = TEMPLATE_TYPE_LEVEL (t);
return level == this_level;
}
/* Worker for uses_outer_template_parms, called via for_each_template_parm.
DATA is really an int, indicating the innermost outer level of parameters.
If T is a template parameter of that level or further out, return
nonzero. */
static int
template_parm_outer_level (tree t, void *data)
{
int this_level = *(int *)data;
int level;
if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
level = TEMPLATE_PARM_LEVEL (t);
else
level = TEMPLATE_TYPE_LEVEL (t);
return level <= this_level;
}
/* Creates a TEMPLATE_DECL for the indicated DECL using the template
parameters given by current_template_args, or reuses a
previously existing one, if appropriate. Returns the DECL, or an
equivalent one, if it is replaced via a call to duplicate_decls.
If IS_FRIEND is true, DECL is a friend declaration. */
tree
push_template_decl_real (tree decl, bool is_friend)
{
tree tmpl;
tree args;
tree info;
tree ctx;
bool is_primary;
bool is_partial;
int new_template_p = 0;
/* True if the template is a member template, in the sense of
[temp.mem]. */
bool member_template_p = false;
if (decl == error_mark_node || !current_template_parms)
return error_mark_node;
/* See if this is a partial specialization. */
is_partial = ((DECL_IMPLICIT_TYPEDEF_P (decl)
&& TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
&& CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
|| (VAR_P (decl)
&& DECL_LANG_SPECIFIC (decl)
&& DECL_TEMPLATE_SPECIALIZATION (decl)
&& TINFO_USED_TEMPLATE_ID (DECL_TEMPLATE_INFO (decl))));
if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
is_friend = true;
if (is_friend)
/* For a friend, we want the context of the friend, not
the type of which it is a friend. */
ctx = CP_DECL_CONTEXT (decl);
else if (CP_DECL_CONTEXT (decl)
&& TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
/* In the case of a virtual function, we want the class in which
it is defined. */
ctx = CP_DECL_CONTEXT (decl);
else
/* Otherwise, if we're currently defining some class, the DECL
is assumed to be a member of the class. */
ctx = current_scope ();
if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
ctx = NULL_TREE;
if (!DECL_CONTEXT (decl))
DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
/* See if this is a primary template. */
if (is_friend && ctx
&& uses_template_parms_level (ctx, processing_template_decl))
/* A friend template that specifies a class context, i.e.
template <typename T> friend void A<T>::f();
is not primary. */
is_primary = false;
else if (TREE_CODE (decl) == TYPE_DECL
&& LAMBDA_TYPE_P (TREE_TYPE (decl)))
is_primary = false;
else
is_primary = template_parm_scope_p ();
if (is_primary)
{
warning (OPT_Wtemplates, "template %qD declared", decl);
if (DECL_CLASS_SCOPE_P (decl))
member_template_p = true;
if (TREE_CODE (decl) == TYPE_DECL
&& anon_aggrname_p (DECL_NAME (decl)))
{
error ("template class without a name");
return error_mark_node;
}
else if (TREE_CODE (decl) == FUNCTION_DECL)
{
if (member_template_p)
{
if (DECL_OVERRIDE_P (decl) || DECL_FINAL_P (decl))
error ("member template %qD may not have virt-specifiers", decl);
}
if (DECL_DESTRUCTOR_P (decl))
{
/* [temp.mem]
A destructor shall not be a member template. */
error ("destructor %qD declared as member template", decl);
return error_mark_node;
}
if (IDENTIFIER_NEWDEL_OP_P (DECL_NAME (decl))
&& (!prototype_p (TREE_TYPE (decl))
|| TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
|| !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
|| (TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
== void_list_node)))
{
/* [basic.stc.dynamic.allocation]
An allocation function can be a function
template. ... Template allocation functions shall
have two or more parameters. */
error ("invalid template declaration of %qD", decl);
return error_mark_node;
}
}
else if (DECL_IMPLICIT_TYPEDEF_P (decl)
&& CLASS_TYPE_P (TREE_TYPE (decl)))
{
/* Class template, set TEMPLATE_TYPE_PARM_FOR_CLASS. */
tree parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
for (int i = 0; i < TREE_VEC_LENGTH (parms); ++i)
{
tree t = TREE_VALUE (TREE_VEC_ELT (parms, i));
if (TREE_CODE (t) == TYPE_DECL)
t = TREE_TYPE (t);
if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
TEMPLATE_TYPE_PARM_FOR_CLASS (t) = true;
}
}
else if (TREE_CODE (decl) == TYPE_DECL
&& TYPE_DECL_ALIAS_P (decl))
/* alias-declaration */
gcc_assert (!DECL_ARTIFICIAL (decl));
else if (VAR_P (decl))
/* C++14 variable template. */;
else
{
error ("template declaration of %q#D", decl);
return error_mark_node;
}
}
/* Check to see that the rules regarding the use of default
arguments are not being violated. We check args for a friend
functions when we know whether it's a definition, introducing
declaration or re-declaration. */
if (!is_friend || TREE_CODE (decl) != FUNCTION_DECL)
check_default_tmpl_args (decl, current_template_parms,
is_primary, is_partial, is_friend);
/* Ensure that there are no parameter packs in the type of this
declaration that have not been expanded. */
if (TREE_CODE (decl) == FUNCTION_DECL)
{
/* Check each of the arguments individually to see if there are
any bare parameter packs. */
tree type = TREE_TYPE (decl);
tree arg = DECL_ARGUMENTS (decl);
tree argtype = TYPE_ARG_TYPES (type);
while (arg && argtype)
{
if (!DECL_PACK_P (arg)
&& check_for_bare_parameter_packs (TREE_TYPE (arg)))
{
/* This is a PARM_DECL that contains unexpanded parameter
packs. We have already complained about this in the
check_for_bare_parameter_packs call, so just replace
these types with ERROR_MARK_NODE. */
TREE_TYPE (arg) = error_mark_node;
TREE_VALUE (argtype) = error_mark_node;
}
arg = DECL_CHAIN (arg);
argtype = TREE_CHAIN (argtype);
}
/* Check for bare parameter packs in the return type and the
exception specifiers. */
if (check_for_bare_parameter_packs (TREE_TYPE (type)))
/* Errors were already issued, set return type to int
as the frontend doesn't expect error_mark_node as
the return type. */
TREE_TYPE (type) = integer_type_node;
if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
}
else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL
&& TYPE_DECL_ALIAS_P (decl))
? DECL_ORIGINAL_TYPE (decl)
: TREE_TYPE (decl)))
{
TREE_TYPE (decl) = error_mark_node;
return error_mark_node;
}
if (is_partial)
return process_partial_specialization (decl);
args = current_template_args ();
if (!ctx
|| TREE_CODE (ctx) == FUNCTION_DECL
|| (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
|| (TREE_CODE (decl) == TYPE_DECL
&& LAMBDA_TYPE_P (TREE_TYPE (decl)))
|| (is_friend && !DECL_TEMPLATE_INFO (decl)))
{
if (DECL_LANG_SPECIFIC (decl)
&& DECL_TEMPLATE_INFO (decl)
&& DECL_TI_TEMPLATE (decl))
tmpl = DECL_TI_TEMPLATE (decl);
/* If DECL is a TYPE_DECL for a class-template, then there won't
be DECL_LANG_SPECIFIC. The information equivalent to
DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
else if (DECL_IMPLICIT_TYPEDEF_P (decl)
&& TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
&& TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
{
/* Since a template declaration already existed for this
class-type, we must be redeclaring it here. Make sure
that the redeclaration is valid. */
redeclare_class_template (TREE_TYPE (decl),
current_template_parms,
current_template_constraints ());
/* We don't need to create a new TEMPLATE_DECL; just use the
one we already had. */
tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
}
else
{
tmpl = build_template_decl (decl, current_template_parms,
member_template_p);
new_template_p = 1;
if (DECL_LANG_SPECIFIC (decl)
&& DECL_TEMPLATE_SPECIALIZATION (decl))
{
/* A specialization of a member template of a template
class. */
SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
DECL_TEMPLATE_INFO (decl) = NULL_TREE;
}
}
}
else
{
tree a, t, current, parms;
int i;
tree tinfo = get_template_info (decl);
if (!tinfo)
{
error ("template definition of non-template %q#D", decl);
return error_mark_node;
}
tmpl = TI_TEMPLATE (tinfo);
if (DECL_FUNCTION_TEMPLATE_P (tmpl)
&& DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
&& DECL_TEMPLATE_SPECIALIZATION (decl)
&& DECL_MEMBER_TEMPLATE_P (tmpl))
{
tree new_tmpl;
/* The declaration is a specialization of a member
template, declared outside the class. Therefore, the
innermost template arguments will be NULL, so we
replace them with the arguments determined by the
earlier call to check_explicit_specialization. */
args = DECL_TI_ARGS (decl);
new_tmpl
= build_template_decl (decl, current_template_parms,
member_template_p);
DECL_TEMPLATE_RESULT (new_tmpl) = decl;
TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
DECL_TI_TEMPLATE (decl) = new_tmpl;
SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
DECL_TEMPLATE_INFO (new_tmpl)
= build_template_info (tmpl, args);
register_specialization (new_tmpl,
most_general_template (tmpl),
args,
is_friend, 0);
return decl;
}
/* Make sure the template headers we got make sense. */
parms = DECL_TEMPLATE_PARMS (tmpl);
i = TMPL_PARMS_DEPTH (parms);
if (TMPL_ARGS_DEPTH (args) != i)
{
error ("expected %d levels of template parms for %q#D, got %d",
i, decl, TMPL_ARGS_DEPTH (args));
DECL_INTERFACE_KNOWN (decl) = 1;
return error_mark_node;
}
else
for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
{
a = TMPL_ARGS_LEVEL (args, i);
t = INNERMOST_TEMPLATE_PARMS (parms);
if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
{
if (current == decl)
error ("got %d template parameters for %q#D",
TREE_VEC_LENGTH (a), decl);
else
error ("got %d template parameters for %q#T",
TREE_VEC_LENGTH (a), current);
error (" but %d required", TREE_VEC_LENGTH (t));
/* Avoid crash in import_export_decl. */
DECL_INTERFACE_KNOWN (decl) = 1;
return error_mark_node;
}
if (current == decl)
current = ctx;
else if (current == NULL_TREE)
/* Can happen in erroneous input. */
break;
else
current = get_containing_scope (current);
}
/* Check that the parms are used in the appropriate qualifying scopes
in the declarator. */
if (!comp_template_args
(TI_ARGS (tinfo),
TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
{
error ("template arguments to %qD do not match original "
"template %qD", decl, DECL_TEMPLATE_RESULT (tmpl));
if (!uses_template_parms (TI_ARGS (tinfo)))
inform (input_location, "use %<template<>%> for"
" an explicit specialization");
/* Avoid crash in import_export_decl. */
DECL_INTERFACE_KNOWN (decl) = 1;
return error_mark_node;
}
}
DECL_TEMPLATE_RESULT (tmpl) = decl;
TREE_TYPE (tmpl) = TREE_TYPE (decl);
/* Push template declarations for global functions and types. Note
that we do not try to push a global template friend declared in a
template class; such a thing may well depend on the template
parameters of the class. */
if (new_template_p && !ctx
&& !(is_friend && template_class_depth (current_class_type) > 0))
{
tmpl = pushdecl_namespace_level (tmpl, is_friend);
if (tmpl == error_mark_node)
return error_mark_node;
/* Hide template friend classes that haven't been declared yet. */
if (is_friend && TREE_CODE (decl) == TYPE_DECL)
{
DECL_ANTICIPATED (tmpl) = 1;
DECL_FRIEND_P (tmpl) = 1;
}
}
if (is_primary)
{
tree parms = DECL_TEMPLATE_PARMS (tmpl);
DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
/* Give template template parms a DECL_CONTEXT of the template
for which they are a parameter. */
parms = INNERMOST_TEMPLATE_PARMS (parms);
for (int i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
{
tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
if (TREE_CODE (parm) == TEMPLATE_DECL)
DECL_CONTEXT (parm) = tmpl;
}
if (TREE_CODE (decl) == TYPE_DECL
&& TYPE_DECL_ALIAS_P (decl)
&& complex_alias_template_p (tmpl))
TEMPLATE_DECL_COMPLEX_ALIAS_P (tmpl) = true;
}
/* The DECL_TI_ARGS of DECL contains full set of arguments referring
back to its most general template. If TMPL is a specialization,
ARGS may only have the innermost set of arguments. Add the missing
argument levels if necessary. */
if (DECL_TEMPLATE_INFO (tmpl))
args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
info = build_template_info (tmpl, args);
if (DECL_IMPLICIT_TYPEDEF_P (decl))
SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
else
{
if (is_primary)
retrofit_lang_decl (decl);
if (DECL_LANG_SPECIFIC (decl))
DECL_TEMPLATE_INFO (decl) = info;
}
if (flag_implicit_templates
&& !is_friend
&& TREE_PUBLIC (decl)
&& VAR_OR_FUNCTION_DECL_P (decl))
/* Set DECL_COMDAT on template instantiations; if we force
them to be emitted by explicit instantiation or -frepo,
mark_needed will tell cgraph to do the right thing. */
DECL_COMDAT (decl) = true;
return DECL_TEMPLATE_RESULT (tmpl);
}
tree
push_template_decl (tree decl)
{
return push_template_decl_real (decl, false);
}
/* FN is an inheriting constructor that inherits from the constructor
template INHERITED; turn FN into a constructor template with a matching
template header. */
tree
add_inherited_template_parms (tree fn, tree inherited)
{
tree inner_parms
= INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (inherited));
inner_parms = copy_node (inner_parms);
tree parms
= tree_cons (size_int (processing_template_decl + 1),
inner_parms, current_template_parms);
tree tmpl = build_template_decl (fn, parms, /*member*/true);
tree args = template_parms_to_args (parms);
DECL_TEMPLATE_INFO (fn) = build_template_info (tmpl, args);
TREE_TYPE (tmpl) = TREE_TYPE (fn);
DECL_TEMPLATE_RESULT (tmpl) = fn;
DECL_ARTIFICIAL (tmpl) = true;
DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
return tmpl;
}
/* Called when a class template TYPE is redeclared with the indicated
template PARMS, e.g.:
template <class T> struct S;
template <class T> struct S {}; */
bool
redeclare_class_template (tree type, tree parms, tree cons)
{
tree tmpl;
tree tmpl_parms;
int i;
if (!TYPE_TEMPLATE_INFO (type))
{
error ("%qT is not a template type", type);
return false;
}
tmpl = TYPE_TI_TEMPLATE (type);
if (!PRIMARY_TEMPLATE_P (tmpl))
/* The type is nested in some template class. Nothing to worry
about here; there are no new template parameters for the nested
type. */
return true;
if (!parms)
{
error ("template specifiers not specified in declaration of %qD",
tmpl);
return false;
}
parms = INNERMOST_TEMPLATE_PARMS (parms);
tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
{
error_n (input_location, TREE_VEC_LENGTH (parms),
"redeclared with %d template parameter",
"redeclared with %d template parameters",
TREE_VEC_LENGTH (parms));
inform_n (DECL_SOURCE_LOCATION (tmpl), TREE_VEC_LENGTH (tmpl_parms),
"previous declaration %qD used %d template parameter",
"previous declaration %qD used %d template parameters",
tmpl, TREE_VEC_LENGTH (tmpl_parms));
return false;
}
for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
{
tree tmpl_parm;
tree parm;
tree tmpl_default;
tree parm_default;
if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
|| TREE_VEC_ELT (parms, i) == error_mark_node)
continue;
tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
if (error_operand_p (tmpl_parm))
return false;
parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
/* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
TEMPLATE_DECL. */
if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
|| (TREE_CODE (tmpl_parm) != TYPE_DECL
&& !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
|| (TREE_CODE (tmpl_parm) != PARM_DECL
&& (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
!= TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
|| (TREE_CODE (tmpl_parm) == PARM_DECL
&& (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
!= TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
{
error ("template parameter %q+#D", tmpl_parm);
error ("redeclared here as %q#D", parm);
return false;
}
if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
{
/* We have in [temp.param]:
A template-parameter may not be given default arguments
by two different declarations in the same scope. */
error_at (input_location, "redefinition of default argument for %q#D", parm);
inform (DECL_SOURCE_LOCATION (tmpl_parm),
"original definition appeared here");
return false;
}
if (parm_default != NULL_TREE)
/* Update the previous template parameters (which are the ones
that will really count) with the new default value. */
TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
else if (tmpl_default != NULL_TREE)
/* Update the new parameters, too; they'll be used as the
parameters for any members. */
TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
/* Give each template template parm in this redeclaration a
DECL_CONTEXT of the template for which they are a parameter. */
if (TREE_CODE (parm) == TEMPLATE_DECL)
{
gcc_assert (DECL_CONTEXT (parm) == NULL_TREE);
DECL_CONTEXT (parm) = tmpl;
}
if (TREE_CODE (parm) == TYPE_DECL)
TEMPLATE_TYPE_PARM_FOR_CLASS (TREE_TYPE (parm)) = true;
}
// Cannot redeclare a class template with a different set of constraints.
if (!equivalent_constraints (get_constraints (tmpl), cons))
{
error_at (input_location, "redeclaration %q#D with different "
"constraints", tmpl);
inform (DECL_SOURCE_LOCATION (tmpl),
"original declaration appeared here");
}
return true;
}
/* The actual substitution part of instantiate_non_dependent_expr_sfinae,
to be used when the caller has already checked
(processing_template_decl
&& !instantiation_dependent_expression_p (expr)
&& potential_constant_expression (expr))
and cleared processing_template_decl. */
tree
instantiate_non_dependent_expr_internal (tree expr, tsubst_flags_t complain)
{
return tsubst_copy_and_build (expr,
/*args=*/NULL_TREE,
complain,
/*in_decl=*/NULL_TREE,
/*function_p=*/false,
/*integral_constant_expression_p=*/true);
}
/* Simplify EXPR if it is a non-dependent expression. Returns the
(possibly simplified) expression. */
tree
instantiate_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
{
if (expr == NULL_TREE)
return NULL_TREE;
/* If we're in a template, but EXPR isn't value dependent, simplify
it. We're supposed to treat:
template <typename T> void f(T[1 + 1]);
template <typename T> void f(T[2]);
as two declarations of the same function, for example. */
if (processing_template_decl
&& is_nondependent_constant_expression (expr))
{
processing_template_decl_sentinel s;
expr = instantiate_non_dependent_expr_internal (expr, complain);
}
return expr;
}
tree
instantiate_non_dependent_expr (tree expr)
{
return instantiate_non_dependent_expr_sfinae (expr, tf_error);
}
/* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
an uninstantiated expression. */
tree
instantiate_non_dependent_or_null (tree expr)
{
if (expr == NULL_TREE)
return NULL_TREE;
if (processing_template_decl)
{
if (!is_nondependent_constant_expression (expr))
expr = NULL_TREE;
else
{
processing_template_decl_sentinel s;
expr = instantiate_non_dependent_expr_internal (expr, tf_error);
}
}
return expr;
}
/* True iff T is a specialization of a variable template. */
bool
variable_template_specialization_p (tree t)
{
if (!VAR_P (t) || !DECL_LANG_SPECIFIC (t) || !DECL_TEMPLATE_INFO (t))
return false;
tree tmpl = DECL_TI_TEMPLATE (t);
return variable_template_p (tmpl);
}
/* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
template declaration, or a TYPE_DECL for an alias declaration. */
bool
alias_type_or_template_p (tree t)
{
if (t == NULL_TREE)
return false;
return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t))
|| (TYPE_P (t)
&& TYPE_NAME (t)
&& TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
|| DECL_ALIAS_TEMPLATE_P (t));
}
/* Return TRUE iff T is a specialization of an alias template. */
bool
alias_template_specialization_p (const_tree t)
{
/* It's an alias template specialization if it's an alias and its
TYPE_NAME is a specialization of a primary template. */
if (TYPE_ALIAS_P (t))
if (tree tinfo = TYPE_ALIAS_TEMPLATE_INFO (t))
return PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo));
return false;
}
/* An alias template is complex from a SFINAE perspective if a template-id
using that alias can be ill-formed when the expansion is not, as with
the void_t template. We determine this by checking whether the
expansion for the alias template uses all its template parameters. */
struct uses_all_template_parms_data
{
int level;
bool *seen;
};
static int
uses_all_template_parms_r (tree t, void *data_)
{
struct uses_all_template_parms_data &data
= *(struct uses_all_template_parms_data*)data_;
tree idx = get_template_parm_index (t);
if (TEMPLATE_PARM_LEVEL (idx) == data.level)
data.seen[TEMPLATE_PARM_IDX (idx)] = true;
return 0;
}
/* for_each_template_parm any_fn callback for complex_alias_template_p. */
static int
complex_pack_expansion_r (tree t, void *data_)
{
/* An alias template with a pack expansion that expands a pack from the
enclosing class needs to be considered complex, to avoid confusion with
the same pack being used as an argument to the alias's own template
parameter (91966). */
if (!PACK_EXPANSION_P (t))
return 0;
struct uses_all_template_parms_data &data
= *(struct uses_all_template_parms_data*)data_;
for (tree pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
pack = TREE_CHAIN (pack))
{
tree parm_pack = TREE_VALUE (pack);
if (!TEMPLATE_PARM_P (parm_pack))
continue;
int idx, level;
template_parm_level_and_index (parm_pack, &level, &idx);
if (level < data.level)
return 1;
}
return 0;
}
static bool
complex_alias_template_p (const_tree tmpl)
{
struct uses_all_template_parms_data data;
tree pat = DECL_ORIGINAL_TYPE (DECL_TEMPLATE_RESULT (tmpl));
tree parms = DECL_TEMPLATE_PARMS (tmpl);
data.level = TMPL_PARMS_DEPTH (parms);
int len = TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS (parms));
data.seen = XALLOCAVEC (bool, len);
for (int i = 0; i < len; ++i)
data.seen[i] = false;
if (for_each_template_parm (pat, uses_all_template_parms_r, &data,
NULL, true, complex_pack_expansion_r))
return true;
for (int i = 0; i < len; ++i)
if (!data.seen[i])
return true;
return false;
}
/* Return TRUE iff T is a specialization of a complex alias template with
dependent template-arguments. */
bool
dependent_alias_template_spec_p (const_tree t)
{
if (!alias_template_specialization_p (t))
return false;
tree tinfo = TYPE_ALIAS_TEMPLATE_INFO (t);
if (!TEMPLATE_DECL_COMPLEX_ALIAS_P (TI_TEMPLATE (tinfo)))
return false;
tree args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo));
if (!any_dependent_template_arguments_p (args))
return false;
return true;
}
/* Return the number of innermost template parameters in TMPL. */
static int
num_innermost_template_parms (tree tmpl)
{
tree parms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (tmpl));
return TREE_VEC_LENGTH (parms);
}
/* Return either TMPL or another template that it is equivalent to under DR
1286: An alias that just changes the name of a template is equivalent to
the other template. */
static tree
get_underlying_template (tree tmpl)
{
gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
while (DECL_ALIAS_TEMPLATE_P (tmpl))
{
/* Determine if the alias is equivalent to an underlying template. */
tree orig_type = DECL_ORIGINAL_TYPE (DECL_TEMPLATE_RESULT (tmpl));
tree tinfo = TYPE_TEMPLATE_INFO_MAYBE_ALIAS (orig_type);
if (!tinfo)
break;
tree underlying = TI_TEMPLATE (tinfo);
if (!PRIMARY_TEMPLATE_P (underlying)
|| (num_innermost_template_parms (tmpl)
!= num_innermost_template_parms (underlying)))
break;
/* Does the alias add cv-quals? */
if (TYPE_QUALS (TREE_TYPE (underlying)) != TYPE_QUALS (TREE_TYPE (tmpl)))
break;
tree alias_args = INNERMOST_TEMPLATE_ARGS
(template_parms_to_args (DECL_TEMPLATE_PARMS (tmpl)));
if (!comp_template_args (TI_ARGS (tinfo), alias_args))
break;
/* Alias is equivalent. Strip it and repeat. */
tmpl = underlying;
}
return tmpl;
}
/* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
must be a reference-to-function or a pointer-to-function type, as specified
in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
and check that the resulting function has external linkage. */
static tree
convert_nontype_argument_function (tree type, tree expr,
tsubst_flags_t complain)
{
tree fns = expr;
tree fn, fn_no_ptr;
linkage_kind linkage;
fn = instantiate_type (type, fns, tf_none);
if (fn == error_mark_node)
return error_mark_node;
if (value_dependent_expression_p (fn))
goto accept;
fn_no_ptr = strip_fnptr_conv (fn);
if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
if (BASELINK_P (fn_no_ptr))
fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
/* [temp.arg.nontype]/1
A template-argument for a non-type, non-template template-parameter
shall be one of:
[...]
-- the address of an object or function with external [C++11: or
internal] linkage. */
STRIP_ANY_LOCATION_WRAPPER (fn_no_ptr);
if (TREE_CODE (fn_no_ptr) != FUNCTION_DECL)
{
if (complain & tf_error)
{
error ("%qE is not a valid template argument for type %qT",
expr, type);
if (TYPE_PTR_P (type))
inform (input_location, "it must be the address of a function "
"with external linkage");
else
inform (input_location, "it must be the name of a function with "
"external linkage");
}
return NULL_TREE;
}
linkage = decl_linkage (fn_no_ptr);
if (cxx_dialect >= cxx11 ? linkage == lk_none : linkage != lk_external)
{
if (complain & tf_error)
{
if (cxx_dialect >= cxx11)
error ("%qE is not a valid template argument for type %qT "
"because %qD has no linkage",
expr, type, fn_no_ptr);
else
error ("%qE is not a valid template argument for type %qT "
"because %qD does not have external linkage",
expr, type, fn_no_ptr);
}
return NULL_TREE;
}
accept:
if (TYPE_REF_P (type))
{
if (REFERENCE_REF_P (fn))
fn = TREE_OPERAND (fn, 0);
else
fn = build_address (fn);
}
if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (fn)))
fn = build_nop (type, fn);
return fn;
}
/* Subroutine of convert_nontype_argument.
Check if EXPR of type TYPE is a valid pointer-to-member constant.
Emit an error otherwise. */
static bool
check_valid_ptrmem_cst_expr (tree type, tree expr,
tsubst_flags_t complain)
{
location_t loc = cp_expr_loc_or_loc (expr, input_location);
tree orig_expr = expr;
STRIP_NOPS (expr);
if (null_ptr_cst_p (expr))
return true;
if (TREE_CODE (expr) == PTRMEM_CST
&& same_type_p (TYPE_PTRMEM_CLASS_TYPE (type),
PTRMEM_CST_CLASS (expr)))
return true;
if (cxx_dialect >= cxx11 && null_member_pointer_value_p (expr))
return true;
if (processing_template_decl
&& TREE_CODE (expr) == ADDR_EXPR
&& TREE_CODE (TREE_OPERAND (expr, 0)) == OFFSET_REF)
return true;
if (complain & tf_error)
{
error_at (loc, "%qE is not a valid template argument for type %qT",
orig_expr, type);
if (TREE_CODE (expr) != PTRMEM_CST)
inform (loc, "it must be a pointer-to-member of the form %<&X::Y%>");
else
inform (loc, "because it is a member of %qT", PTRMEM_CST_CLASS (expr));
}
return false;
}
/* Returns TRUE iff the address of OP is value-dependent.
14.6.2.4 [temp.dep.temp]:
A non-integral non-type template-argument is dependent if its type is
dependent or it has either of the following forms
qualified-id
& qualified-id
and contains a nested-name-specifier which specifies a class-name that
names a dependent type.
We generalize this to just say that the address of a member of a
dependent class is value-dependent; the above doesn't cover the
address of a static data member named with an unqualified-id. */
static bool
has_value_dependent_address (tree op)
{
STRIP_ANY_LOCATION_WRAPPER (op);
/* We could use get_inner_reference here, but there's no need;
this is only relevant for template non-type arguments, which
can only be expressed as &id-expression. */
if (DECL_P (op))
{
tree ctx = CP_DECL_CONTEXT (op);
if (TYPE_P (ctx) && dependent_type_p (ctx))
return true;
}
return false;
}
/* The next set of functions are used for providing helpful explanatory
diagnostics for failed overload resolution. Their messages should be
indented by two spaces for consistency with the messages in
call.c */
static int
unify_success (bool /*explain_p*/)
{
return 0;
}
/* Other failure functions should call this one, to provide a single function
for setting a breakpoint on. */
static int
unify_invalid (bool /*explain_p*/)
{
return 1;
}
static int
unify_parameter_deduction_failure (bool explain_p, tree parm)
{
if (explain_p)
inform (input_location,
" couldn%'t deduce template parameter %qD", parm);
return unify_invalid (explain_p);
}
static int
unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
{
if (explain_p)
inform (input_location,
" types %qT and %qT have incompatible cv-qualifiers",
parm, arg);
return unify_invalid (explain_p);
}
static int
unify_type_mismatch (bool explain_p, tree parm, tree arg)
{
if (explain_p)
inform (input_location, " mismatched types %qT and %qT", parm, arg);
return unify_invalid (explain_p);
}
static int
unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
{
if (explain_p)
inform (input_location,
" template parameter %qD is not a parameter pack, but "
"argument %qD is",
parm, arg);
return unify_invalid (explain_p);
}
static int
unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
{
if (explain_p)
inform (input_location,
" template argument %qE does not match "
"pointer-to-member constant %qE",
arg, parm);
return unify_invalid (explain_p);
}
static int
unify_expression_unequal (bool explain_p, tree parm, tree arg)
{
if (explain_p)
inform (input_location, " %qE is not equivalent to %qE", parm, arg);
return unify_invalid (explain_p);
}
static int
unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
{
if (explain_p)
inform (input_location,
" inconsistent parameter pack deduction with %qT and %qT",
old_arg, new_arg);
return unify_invalid (explain_p);
}
static int
unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
{
if (explain_p)
{
if (TYPE_P (parm))
inform (input_location,
" deduced conflicting types for parameter %qT (%qT and %qT)",
parm, first, second);
else
inform (input_location,
" deduced conflicting values for non-type parameter "
"%qE (%qE and %qE)", parm, first, second);
}
return unify_invalid (explain_p);
}
static int
unify_vla_arg (bool explain_p, tree arg)
{
if (explain_p)
inform (input_location,
" variable-sized array type %qT is not "
"a valid template argument",
arg);
return unify_invalid (explain_p);
}
static int
unify_method_type_error (bool explain_p, tree arg)
{
if (explain_p)
inform (input_location,
" member function type %qT is not a valid template argument",
arg);
return unify_invalid (explain_p);
}
static int
unify_arity (bool explain_p, int have, int wanted, bool least_p = false)
{
if (explain_p)
{
if (least_p)
inform_n (input_location, wanted,
" candidate expects at least %d argument, %d provided",
" candidate expects at least %d arguments, %d provided",
wanted, have);
else
inform_n (input_location, wanted,
" candidate expects %d argument, %d provided",
" candidate expects %d arguments, %d provided",
wanted, have);
}
return unify_invalid (explain_p);
}
static int
unify_too_many_arguments (bool explain_p, int have, int wanted)
{
return unify_arity (explain_p, have, wanted);
}
static int
unify_too_few_arguments (bool explain_p, int have, int wanted,
bool least_p = false)
{
return unify_arity (explain_p, have, wanted, least_p);
}
static int
unify_arg_conversion (bool explain_p, tree to_type,
tree from_type, tree arg)
{
if (explain_p)
inform (cp_expr_loc_or_loc (arg, input_location),
" cannot convert %qE (type %qT) to type %qT",
arg, from_type, to_type);
return unify_invalid (explain_p);
}
static int
unify_no_common_base (bool explain_p, enum template_base_result r,
tree parm, tree arg)
{
if (explain_p)
switch (r)
{
case tbr_ambiguous_baseclass:
inform (input_location, " %qT is an ambiguous base class of %qT",
parm, arg);
break;
default:
inform (input_location, " %qT is not derived from %qT", arg, parm);
break;
}
return unify_invalid (explain_p);
}
static int
unify_inconsistent_template_template_parameters (bool explain_p)
{
if (explain_p)
inform (input_location,
" template parameters of a template template argument are "
"inconsistent with other deduced template arguments");
return unify_invalid (explain_p);
}
static int
unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
{
if (explain_p)
inform (input_location,
" can%'t deduce a template for %qT from non-template type %qT",
parm, arg);
return unify_invalid (explain_p);
}
static int
unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
{
if (explain_p)
inform (input_location,
" template argument %qE does not match %qE", arg, parm);
return unify_invalid (explain_p);
}
/* True if T is a C++20 template parameter object to store the argument for a
template parameter of class type. */
bool
template_parm_object_p (const_tree t)
{
return (TREE_CODE (t) == VAR_DECL && DECL_ARTIFICIAL (t) && DECL_NAME (t)
&& !strncmp (IDENTIFIER_POINTER (DECL_NAME (t)), "_ZTA", 4));
}
/* Subroutine of convert_nontype_argument, to check whether EXPR, as an
argument for TYPE, points to an unsuitable object. */
static bool
invalid_tparm_referent_p (tree type, tree expr, tsubst_flags_t complain)
{
switch (TREE_CODE (expr))
{
CASE_CONVERT:
return invalid_tparm_referent_p (type, TREE_OPERAND (expr, 0),
complain);
case TARGET_EXPR:
return invalid_tparm_referent_p (type, TARGET_EXPR_INITIAL (expr),
complain);
case CONSTRUCTOR:
{
unsigned i; tree elt;
FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), i, elt)
if (invalid_tparm_referent_p (TREE_TYPE (elt), elt, complain))
return true;
}
break;
case ADDR_EXPR:
{
tree decl = TREE_OPERAND (expr, 0);
if (!VAR_P (decl))
{
if (complain & tf_error)
error ("%qE is not a valid template argument of type %qT "
"because %qE is not a variable", expr, type, decl);
return true;
}
else if (cxx_dialect < cxx11 && !DECL_EXTERNAL_LINKAGE_P (decl))
{
if (complain & tf_error)
error ("%qE is not a valid template argument of type %qT "
"in C++98 because %qD does not have external linkage",
expr, type, decl);
return true;
}
else if ((cxx_dialect >= cxx11 && cxx_dialect < cxx17)
&& decl_linkage (decl) == lk_none)
{
if (complain & tf_error)
error ("%qE is not a valid template argument of type %qT "
"because %qD has no linkage", expr, type, decl);
return true;
}
/* C++17: For a non-type template-parameter of reference or pointer
type, the value of the constant expression shall not refer to (or
for a pointer type, shall not be the address of):
* a subobject (4.5),
* a temporary object (15.2),
* a string literal (5.13.5),
* the result of a typeid expression (8.2.8), or
* a predefined __func__ variable (11.4.1). */
else if (DECL_ARTIFICIAL (decl))
{
if (complain & tf_error)
error ("the address of %qD is not a valid template argument",
decl);
return true;
}
else if (!same_type_ignoring_top_level_qualifiers_p
(strip_array_types (TREE_TYPE (type)),
strip_array_types (TREE_TYPE (decl))))
{
if (complain & tf_error)
error ("the address of the %qT subobject of %qD is not a "
"valid template argument", TREE_TYPE (type), decl);
return true;
}
else if (!TREE_STATIC (decl) && !DECL_EXTERNAL (decl))
{
if (complain & tf_error)
error ("the address of %qD is not a valid template argument "
"because it does not have static storage duration",
decl);
return true;
}
}
break;
default:
if (!INDIRECT_TYPE_P (type))
/* We're only concerned about pointers and references here. */;
else if (cxx_dialect >= cxx11 && integer_zerop (expr))
/* Null pointer values are OK in C++11. */;
else
{
if (VAR_P (expr))
{
if (complain & tf_error)
error ("%qD is not a valid template argument "
"because %qD is a variable, not the address of "
"a variable", expr, expr);
return true;
}
else
{
if (complain & tf_error)
error ("%qE is not a valid template argument for %qT "
"because it is not the address of a variable",
expr, type);
return true;
}
}
}
return false;
}
/* The template arguments corresponding to template parameter objects of types
that contain pointers to members. */
static GTY(()) hash_map<tree, tree> *tparm_obj_values;
/* Return a VAR_DECL for the C++20 template parameter object corresponding to
template argument EXPR. */
static tree
get_template_parm_object (tree expr, tsubst_flags_t complain)
{
if (TREE_CODE (expr) == TARGET_EXPR)
expr = TARGET_EXPR_INITIAL (expr);
if (!TREE_CONSTANT (expr))
{
if ((complain & tf_error)
&& require_rvalue_constant_expression (expr))
cxx_constant_value (expr);
return error_mark_node;
}
if (invalid_tparm_referent_p (TREE_TYPE (expr), expr, complain))
return error_mark_node;
tree name = mangle_template_parm_object (expr);
tree decl = get_global_binding (name);
if (decl)
return decl;
tree type = cp_build_qualified_type (TREE_TYPE (expr), TYPE_QUAL_CONST);
decl = create_temporary_var (type);
TREE_STATIC (decl) = true;
DECL_DECLARED_CONSTEXPR_P (decl) = true;
TREE_READONLY (decl) = true;
DECL_NAME (decl) = name;
SET_DECL_ASSEMBLER_NAME (decl, name);
DECL_CONTEXT (decl) = global_namespace;
comdat_linkage (decl);
if (!zero_init_p (type))
{
/* If EXPR contains any PTRMEM_CST, they will get clobbered by
lower_var_init before we're done mangling. So store the original
value elsewhere. */
tree copy = unshare_constructor (expr);
if (!tparm_obj_values)
tparm_obj_values = hash_map<tree, tree>::create_ggc (13);
tparm_obj_values->put (decl, copy);
}
pushdecl_top_level_and_finish (decl, expr);
return decl;
}
/* Return the actual template argument corresponding to template parameter
object VAR. */
tree
tparm_object_argument (tree var)
{
if (zero_init_p (TREE_TYPE (var)))
return DECL_INITIAL (var);
return *(tparm_obj_values->get (var));
}
/* Attempt to convert the non-type template parameter EXPR to the
indicated TYPE. If the conversion is successful, return the
converted value. If the conversion is unsuccessful, return
NULL_TREE if we issued an error message, or error_mark_node if we
did not. We issue error messages for out-and-out bad template
parameters, but not simply because the conversion failed, since we
might be just trying to do argument deduction. Both TYPE and EXPR
must be non-dependent.
The conversion follows the special rules described in
[temp.arg.nontype], and it is much more strict than an implicit
conversion.
This function is called twice for each template argument (see
lookup_template_class for a more accurate description of this
problem). This means that we need to handle expressions which
are not valid in a C++ source, but can be created from the
first call (for instance, casts to perform conversions). These
hacks can go away after we fix the double coercion problem. */
static tree
convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
{
tree expr_type;
location_t loc = cp_expr_loc_or_loc (expr, input_location);
/* Detect immediately string literals as invalid non-type argument.
This special-case is not needed for correctness (we would easily
catch this later), but only to provide better diagnostic for this
common user mistake. As suggested by DR 100, we do not mention
linkage issues in the diagnostic as this is not the point. */
if (TREE_CODE (expr) == STRING_CST && !CLASS_TYPE_P (type))
{
if (complain & tf_error)
error ("%qE is not a valid template argument for type %qT "
"because string literals can never be used in this context",
expr, type);
return NULL_TREE;
}
/* Add the ADDR_EXPR now for the benefit of
value_dependent_expression_p. */
if (TYPE_PTROBV_P (type)
&& TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
{
expr = decay_conversion (expr, complain);
if (expr == error_mark_node)
return error_mark_node;
}
/* If we are in a template, EXPR may be non-dependent, but still
have a syntactic, rather than semantic, form. For example, EXPR
might be a SCOPE_REF, rather than the VAR_DECL to which the
SCOPE_REF refers. Preserving the qualifying scope is necessary
so that access checking can be performed when the template is
instantiated -- but here we need the resolved form so that we can
convert the argument. */
bool non_dep = false;
if (TYPE_REF_OBJ_P (type)
&& has_value_dependent_address (expr))
/* If we want the address and it's value-dependent, don't fold. */;
else if (processing_template_decl
&& is_nondependent_constant_expression (expr))
non_dep = true;
if (error_operand_p (expr))
return error_mark_node;
expr_type = TREE_TYPE (expr);
/* If the argument is non-dependent, perform any conversions in
non-dependent context as well. */
processing_template_decl_sentinel s (non_dep);
if (non_dep)
expr = instantiate_non_dependent_expr_internal (expr, complain);
if (value_dependent_expression_p (expr))
expr = canonicalize_expr_argument (expr, complain);
/* 14.3.2/5: The null pointer{,-to-member} conversion is applied
to a non-type argument of "nullptr". */
if (NULLPTR_TYPE_P (expr_type) && TYPE_PTR_OR_PTRMEM_P (type))
expr = fold_simple (convert (type, expr));
/* In C++11, integral or enumeration non-type template arguments can be
arbitrary constant expressions. Pointer and pointer to
member arguments can be general constant expressions that evaluate
to a null value, but otherwise still need to be of a specific form. */
if (cxx_dialect >= cxx11)
{
if (TREE_CODE (expr) == PTRMEM_CST && TYPE_PTRMEM_P (type))
/* A PTRMEM_CST is already constant, and a valid template
argument for a parameter of pointer to member type, we just want
to leave it in that form rather than lower it to a
CONSTRUCTOR. */;
else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)
|| cxx_dialect >= cxx17)
{
/* Calling build_converted_constant_expr might create a call to
a conversion function with a value-dependent argument, which
could invoke taking the address of a temporary representing
the result of the conversion. */
if (COMPOUND_LITERAL_P (expr)
&& CONSTRUCTOR_IS_DEPENDENT (expr)
&& MAYBE_CLASS_TYPE_P (expr_type)
&& TYPE_HAS_CONVERSION (expr_type))
{
expr = build1 (IMPLICIT_CONV_EXPR, type, expr);
IMPLICIT_CONV_EXPR_NONTYPE_ARG (expr) = true;
return expr;
}
/* C++17: A template-argument for a non-type template-parameter shall
be a converted constant expression (8.20) of the type of the
template-parameter. */
expr = build_converted_constant_expr (type, expr, complain);
if (expr == error_mark_node)
/* Make sure we return NULL_TREE only if we have really issued
an error, as described above. */
return (complain & tf_error) ? NULL_TREE : error_mark_node;
expr = maybe_constant_value (expr, NULL_TREE,
/*manifestly_const_eval=*/true);
expr = convert_from_reference (expr);
}
else if (TYPE_PTR_OR_PTRMEM_P (type))
{
tree folded = maybe_constant_value (expr, NULL_TREE,
/*manifestly_const_eval=*/true);
if (TYPE_PTR_P (type) ? integer_zerop (folded)
: null_member_pointer_value_p (folded))
expr = folded;
}
}
if (TYPE_REF_P (type))
expr = mark_lvalue_use (expr);
else
expr = mark_rvalue_use (expr);
/* HACK: Due to double coercion, we can get a
NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
which is the tree that we built on the first call (see
below when coercing to reference to object or to reference to
function). We just strip everything and get to the arg.
See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
for examples. */
if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
{
tree probe_type, probe = expr;
if (REFERENCE_REF_P (probe))
probe = TREE_OPERAND (probe, 0);
probe_type = TREE_TYPE (probe);
if (TREE_CODE (probe) == NOP_EXPR)
{
/* ??? Maybe we could use convert_from_reference here, but we
would need to relax its constraints because the NOP_EXPR
could actually change the type to something more cv-qualified,
and this is not folded by convert_from_reference. */
tree addr = TREE_OPERAND (probe, 0);
if (TYPE_REF_P (probe_type)
&& TREE_CODE (addr) == ADDR_EXPR
&& TYPE_PTR_P (TREE_TYPE (addr))
&& (same_type_ignoring_top_level_qualifiers_p
(TREE_TYPE (probe_type),
TREE_TYPE (TREE_TYPE (addr)))))
{
expr = TREE_OPERAND (addr, 0);
expr_type = TREE_TYPE (probe_type);
}
}
}
/* [temp.arg.nontype]/5, bullet 1
For a non-type template-parameter of integral or enumeration type,
integral promotions (_conv.prom_) and integral conversions
(_conv.integral_) are applied. */
if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
{
if (cxx_dialect < cxx11)
{
tree t = build_converted_constant_expr (type, expr, complain);
t = maybe_constant_value (t);
if (t != error_mark_node)
expr = t;
}
if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
return error_mark_node;
/* Notice that there are constant expressions like '4 % 0' which
do not fold into integer constants. */
if (TREE_CODE (expr) != INTEGER_CST
&& !value_dependent_expression_p (expr))
{
if (complain & tf_error)
{
int errs = errorcount, warns = warningcount + werrorcount;
if (!require_potential_constant_expression (expr))
expr = error_mark_node;
else
expr = cxx_constant_value (expr);
if (errorcount > errs || warningcount + werrorcount > warns)
inform (loc, "in template argument for type %qT", type);
if (expr == error_mark_node)
return NULL_TREE;
/* else cxx_constant_value complained but gave us
a real constant, so go ahead. */
if (TREE_CODE (expr) != INTEGER_CST)
{
/* Some assemble time constant expressions like
(intptr_t)&&lab1 - (intptr_t)&&lab2 or
4 + (intptr_t)&&var satisfy reduced_constant_expression_p
as we can emit them into .rodata initializers of
variables, yet they can't fold into an INTEGER_CST at
compile time. Refuse them here. */
gcc_checking_assert (reduced_constant_expression_p (expr));
error_at (loc, "template argument %qE for type %qT not "
"a constant integer", expr, type);
return NULL_TREE;
}
}
else
return NULL_TREE;
}
/* Avoid typedef problems. */
if (TREE_TYPE (expr) != type)
expr = fold_convert (type, expr);
}
/* [temp.arg.nontype]/5, bullet 2
For a non-type template-parameter of type pointer to object,
qualification conversions (_conv.qual_) and the array-to-pointer
conversion (_conv.array_) are applied. */
else if (TYPE_PTROBV_P (type))
{
tree decayed = expr;
/* Look through any NOP_EXPRs around an ADDR_EXPR, whether they come from
decay_conversion or an explicit cast. If it's a problematic cast,
we'll complain about it below. */
if (TREE_CODE (expr) == NOP_EXPR)
{
tree probe = expr;
STRIP_NOPS (probe);
if (TREE_CODE (probe) == ADDR_EXPR
&& TYPE_PTR_P (TREE_TYPE (probe)))
{
expr = probe;
expr_type = TREE_TYPE (expr);
}
}
/* [temp.arg.nontype]/1 (TC1 version, DR 49):
A template-argument for a non-type, non-template template-parameter
shall be one of: [...]
-- the name of a non-type template-parameter;
-- the address of an object or function with external linkage, [...]
expressed as "& id-expression" where the & is optional if the name
refers to a function or array, or if the corresponding
template-parameter is a reference.
Here, we do not care about functions, as they are invalid anyway
for a parameter of type pointer-to-object. */
if (value_dependent_expression_p (expr))
/* Non-type template parameters are OK. */
;
else if (cxx_dialect >= cxx11 && integer_zerop (expr))
/* Null pointer values are OK in C++11. */;
else if (TREE_CODE (expr) != ADDR_EXPR
&& !INDIRECT_TYPE_P (expr_type))
/* Other values, like integer constants, might be valid
non-type arguments of some other type. */
return error_mark_node;
else if (invalid_tparm_referent_p (type, expr, complain))
return NULL_TREE;
expr = decayed;
expr = perform_qualification_conversions (type, expr);
if (expr == error_mark_node)
return error_mark_node;
}
/* [temp.arg.nontype]/5, bullet 3
For a non-type template-parameter of type reference to object, no
conversions apply. The type referred to by the reference may be more
cv-qualified than the (otherwise identical) type of the
template-argument. The template-parameter is bound directly to the
template-argument, which must be an lvalue. */
else if (TYPE_REF_OBJ_P (type))
{
if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
expr_type))
return error_mark_node;
if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
{
if (complain & tf_error)
error ("%qE is not a valid template argument for type %qT "
"because of conflicts in cv-qualification", expr, type);
return NULL_TREE;
}
if (!lvalue_p (expr))
{
if (complain & tf_error)
error ("%qE is not a valid template argument for type %qT "
"because it is not an lvalue", expr, type);
return NULL_TREE;
}
/* [temp.arg.nontype]/1
A template-argument for a non-type, non-template template-parameter
shall be one of: [...]
-- the address of an object or function with external linkage. */
if (INDIRECT_REF_P (expr)
&& TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
{
expr = TREE_OPERAND (expr, 0);
if (DECL_P (expr))
{
if (complain & tf_error)
error ("%q#D is not a valid template argument for type %qT "
"because a reference variable does not have a constant "
"address", expr, type);
return NULL_TREE;
}
}
if (TYPE_REF_OBJ_P (TREE_TYPE (expr))
&& value_dependent_expression_p (expr))
/* OK, dependent reference. We don't want to ask whether a DECL is
itself value-dependent, since what we want here is its address. */;
else
{
expr = build_address (expr);
if (invalid_tparm_referent_p (type, expr, complain))
return NULL_TREE;
}
if (!same_type_p (type, TREE_TYPE (expr)))
expr = build_nop (type, expr);
}
/* [temp.arg.nontype]/5, bullet 4
For a non-type template-parameter of type pointer to function, only
the function-to-pointer conversion (_conv.func_) is applied. If the
template-argument represents a set of overloaded functions (or a
pointer to such), the matching function is selected from the set
(_over.over_). */
else if (TYPE_PTRFN_P (type))
{
/* If the argument is a template-id, we might not have enough
context information to decay the pointer. */
if (!type_unknown_p (expr_type))
{
expr = decay_conversion (expr, complain);
if (expr == error_mark_node)
return error_mark_node;
}
if (cxx_dialect >= cxx11 && integer_zerop (expr))
/* Null pointer values are OK in C++11. */
return perform_qualification_conversions (type, expr);
expr = convert_nontype_argument_function (type, expr, complain);
if (!expr || expr == error_mark_node)
return expr;
}
/* [temp.arg.nontype]/5, bullet 5
For a non-type template-parameter of type reference to function, no
conversions apply. If the template-argument represents a set of
overloaded functions, the matching function is selected from the set
(_over.over_). */
else if (TYPE_REFFN_P (type))
{
if (TREE_CODE (expr) == ADDR_EXPR)
{
if (complain & tf_error)
{
error ("%qE is not a valid template argument for type %qT "
"because it is a pointer", expr, type);
inform (input_location, "try using %qE instead",
TREE_OPERAND (expr, 0));
}
return NULL_TREE;
}
expr = convert_nontype_argument_function (type, expr, complain);
if (!expr || expr == error_mark_node)
return expr;
}
/* [temp.arg.nontype]/5, bullet 6
For a non-type template-parameter of type pointer to member function,
no conversions apply. If the template-argument represents a set of
overloaded member functions, the matching member function is selected
from the set (_over.over_). */
else if (TYPE_PTRMEMFUNC_P (type))
{
expr = instantiate_type (type, expr, tf_none);
if (expr == error_mark_node)
return error_mark_node;
/* [temp.arg.nontype] bullet 1 says the pointer to member
expression must be a pointer-to-member constant. */
if (!value_dependent_expression_p (expr)
&& !check_valid_ptrmem_cst_expr (type, expr, complain))
return NULL_TREE;
/* Repeated conversion can't deal with a conversion that turns PTRMEM_CST
into a CONSTRUCTOR, so build up a new PTRMEM_CST instead. */
if (fnptr_conv_p (type, TREE_TYPE (expr)))
expr = make_ptrmem_cst (type, PTRMEM_CST_MEMBER (expr));
}
/* [temp.arg.nontype]/5, bullet 7
For a non-type template-parameter of type pointer to data member,
qualification conversions (_conv.qual_) are applied. */
else if (TYPE_PTRDATAMEM_P (type))
{
/* [temp.arg.nontype] bullet 1 says the pointer to member
expression must be a pointer-to-member constant. */
if (!value_dependent_expression_p (expr)
&& !check_valid_ptrmem_cst_expr (type, expr, complain))
return NULL_TREE;
expr = perform_qualification_conversions (type, expr);
if (expr == error_mark_node)
return expr;
}
else if (NULLPTR_TYPE_P (type))
{
if (!NULLPTR_TYPE_P (TREE_TYPE (expr)))
{
if (complain & tf_error)
error ("%qE is not a valid template argument for type %qT "
"because it is of type %qT", expr, type, TREE_TYPE (expr));
return NULL_TREE;
}
return expr;
}
else if (CLASS_TYPE_P (type))
{
/* Replace the argument with a reference to the corresponding template
parameter object. */
if (!value_dependent_expression_p (expr))
expr = get_template_parm_object (expr, complain);
if (expr == error_mark_node)
return NULL_TREE;
}
/* A template non-type parameter must be one of the above. */
else
gcc_unreachable ();
/* Sanity check: did we actually convert the argument to the
right type? */
gcc_assert (same_type_ignoring_top_level_qualifiers_p
(type, TREE_TYPE (expr)));
return convert_from_reference (expr);
}
/* Subroutine of coerce_template_template_parms, which returns 1 if
PARM_PARM and ARG_PARM match using the rule for the template
parameters of template template parameters. Both PARM and ARG are
template parameters; the rest of the arguments are the same as for
coerce_template_template_parms.
*/
static int
coerce_template_template_parm (tree parm,
tree arg,
tsubst_flags_t complain,
tree in_decl,
tree outer_args)
{
if (arg == NULL_TREE || error_operand_p (arg)
|| parm == NULL_TREE || error_operand_p (parm))
return 0;
if (TREE_CODE (arg) != TREE_CODE (parm))
return 0;
switch (TREE_CODE (parm))
{
case TEMPLATE_DECL:
/* We encounter instantiations of templates like
template <template <template <class> class> class TT>
class C; */
{
tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
if (!coerce_template_template_parms
(parmparm, argparm, complain, in_decl, outer_args))
return 0;
}
/* Fall through. */
case TYPE_DECL:
if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
&& !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
/* Argument is a parameter pack but parameter is not. */
return 0;
break;
case PARM_DECL:
/* The tsubst call is used to handle cases such as
template <int> class C {};
template <class T, template <T> class TT> class D {};
D<int, C> d;
i.e. the parameter list of TT depends on earlier parameters. */
if (!uses_template_parms (TREE_TYPE (arg)))
{
tree t = tsubst (TREE_TYPE (parm), outer_args, complain, in_decl);
if (!uses_template_parms (t)
&& !same_type_p (t, TREE_TYPE (arg)))
return 0;
}
if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
&& !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
/* Argument is a parameter pack but parameter is not. */
return 0;
break;
default:
gcc_unreachable ();
}
return 1;
}
/* Coerce template argument list ARGLIST for use with template
template-parameter TEMPL. */
static tree
coerce_template_args_for_ttp (tree templ, tree arglist,
tsubst_flags_t complain)
{
/* Consider an example where a template template parameter declared as
template <class T, class U = std::allocator<T> > class TT
The template parameter level of T and U are one level larger than
of TT. To proper process the default argument of U, say when an
instantiation `TT<int>' is seen, we need to build the full
arguments containing {int} as the innermost level. Outer levels,
available when not appearing as default template argument, can be
obtained from the arguments of the enclosing template.
Suppose that TT is later substituted with std::vector. The above
instantiation is `TT<int, std::allocator<T> >' with TT at
level 1, and T at level 2, while the template arguments at level 1
becomes {std::vector} and the inner level 2 is {int}. */
tree outer = DECL_CONTEXT (templ);
if (outer)
{
if (DECL_TEMPLATE_SPECIALIZATION (outer))
/* We want arguments for the partial specialization, not arguments for
the primary template. */
outer = template_parms_to_args (DECL_TEMPLATE_PARMS (outer));
else
outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
}
else if (current_template_parms)
{
/* This is an argument of the current template, so we haven't set
DECL_CONTEXT yet. */
tree relevant_template_parms;
/* Parameter levels that are greater than the level of the given
template template parm are irrelevant. */
relevant_template_parms = current_template_parms;
while (TMPL_PARMS_DEPTH (relevant_template_parms)
!= TEMPLATE_TYPE_LEVEL (TREE_TYPE (templ)))
relevant_template_parms = TREE_CHAIN (relevant_template_parms);
outer = template_parms_to_args (relevant_template_parms);
}
if (outer)
arglist = add_to_template_args (outer, arglist);
tree parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
return coerce_template_parms (parmlist, arglist, templ,
complain,
/*require_all_args=*/true,
/*use_default_args=*/true);
}
/* A cache of template template parameters with match-all default
arguments. */
static GTY((deletable)) hash_map<tree,tree> *defaulted_ttp_cache;
static void
store_defaulted_ttp (tree v, tree t)
{
if (!defaulted_ttp_cache)
defaulted_ttp_cache = hash_map<tree,tree>::create_ggc (13);
defaulted_ttp_cache->put (v, t);
}
static tree
lookup_defaulted_ttp (tree v)
{
if (defaulted_ttp_cache)
if (tree *p = defaulted_ttp_cache->get (v))
return *p;
return NULL_TREE;
}
/* T is a bound template template-parameter. Copy its arguments into default
arguments of the template template-parameter's template parameters. */
static tree
add_defaults_to_ttp (tree otmpl)
{
if (tree c = lookup_defaulted_ttp (otmpl))
return c;
tree ntmpl = copy_node (otmpl);
tree ntype = copy_node (TREE_TYPE (otmpl));
TYPE_STUB_DECL (ntype) = TYPE_NAME (ntype) = ntmpl;
TYPE_MAIN_VARIANT (ntype) = ntype;
TYPE_POINTER_TO (ntype) = TYPE_REFERENCE_TO (ntype) = NULL_TREE;
TYPE_NAME (ntype) = ntmpl;
SET_TYPE_STRUCTURAL_EQUALITY (ntype);
tree idx = TEMPLATE_TYPE_PARM_INDEX (ntype)
= copy_node (TEMPLATE_TYPE_PARM_INDEX (ntype));
TEMPLATE_PARM_DECL (idx) = ntmpl;
TREE_TYPE (ntmpl) = TREE_TYPE (idx) = ntype;
tree oparms = DECL_TEMPLATE_PARMS (otmpl);
tree parms = DECL_TEMPLATE_PARMS (ntmpl) = copy_node (oparms);
TREE_CHAIN (parms) = TREE_CHAIN (oparms);
tree vec = TREE_VALUE (parms) = copy_node (TREE_VALUE (parms));
for (int i = 0; i < TREE_VEC_LENGTH (vec); ++i)
{
tree o = TREE_VEC_ELT (vec, i);
if (!template_parameter_pack_p (TREE_VALUE (o)))
{
tree n = TREE_VEC_ELT (vec, i) = copy_node (o);
TREE_PURPOSE (n) = any_targ_node;
}
}
store_defaulted_ttp (otmpl, ntmpl);
return ntmpl;
}
/* ARG is a bound potential template template-argument, and PARGS is a list
of arguments for the corresponding template template-parameter. Adjust
PARGS as appropriate for application to ARG's template, and if ARG is a
BOUND_TEMPLATE_TEMPLATE_PARM, possibly adjust it to add default template
arguments to the template template parameter. */
static tree
coerce_ttp_args_for_tta (tree& arg, tree pargs, tsubst_flags_t complain)
{
++processing_template_decl;
tree arg_tmpl = TYPE_TI_TEMPLATE (arg);
if (DECL_TEMPLATE_TEMPLATE_PARM_P (arg_tmpl))
{
/* When comparing two template template-parameters in partial ordering,
rewrite the one currently being used as an argument to have default
arguments for all parameters. */
arg_tmpl = add_defaults_to_ttp (arg_tmpl);
pargs = coerce_template_args_for_ttp (arg_tmpl, pargs, complain);
if (pargs != error_mark_node)
arg = bind_template_template_parm (TREE_TYPE (arg_tmpl),
TYPE_TI_ARGS (arg));
}
else
{
tree aparms
= INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (arg_tmpl));
pargs = coerce_template_parms (aparms, pargs, arg_tmpl, complain,
/*require_all*/true,
/*use_default*/true);
}
--processing_template_decl;
return pargs;
}
/* Subroutine of unify for the case when PARM is a
BOUND_TEMPLATE_TEMPLATE_PARM. */
static int
unify_bound_ttp_args (tree tparms, tree targs, tree parm, tree& arg,
bool explain_p)
{
tree parmvec = TYPE_TI_ARGS (parm);
tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
/* The template template parm might be variadic and the argument
not, so flatten both argument lists. */
parmvec = expand_template_argument_pack (parmvec);
argvec = expand_template_argument_pack (argvec);
if (flag_new_ttp)
{
/* In keeping with P0522R0, adjust P's template arguments
to apply to A's template; then flatten it again. */
tree nparmvec = parmvec;
nparmvec = coerce_ttp_args_for_tta (arg, parmvec, tf_none);
nparmvec = expand_template_argument_pack (nparmvec);
if (unify (tparms, targs, nparmvec, argvec,
UNIFY_ALLOW_NONE, explain_p))
return 1;
/* If the P0522 adjustment eliminated a pack expansion, deduce
empty packs. */
if (flag_new_ttp
&& TREE_VEC_LENGTH (nparmvec) < TREE_VEC_LENGTH (parmvec)
&& unify_pack_expansion (tparms, targs, parmvec, argvec,
DEDUCE_EXACT, /*sub*/true, explain_p))
return 1;
}
else
{
/* Deduce arguments T, i from TT<T> or TT<i>.
We check each element of PARMVEC and ARGVEC individually
rather than the whole TREE_VEC since they can have
different number of elements, which is allowed under N2555. */
int len = TREE_VEC_LENGTH (parmvec);
/* Check if the parameters end in a pack, making them
variadic. */
int parm_variadic_p = 0;
if (len > 0
&& PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
parm_variadic_p = 1;
for (int i = 0; i < len - parm_variadic_p; ++i)
/* If the template argument list of P contains a pack
expansion that is not the last template argument, the
entire template argument list is a non-deduced
context. */
if (PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, i)))
return unify_success (explain_p);
if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
return unify_too_few_arguments (explain_p,
TREE_VEC_LENGTH (argvec), len);
for (int i = 0; i < len - parm_variadic_p; ++i)
if (unify (tparms, targs,
TREE_VEC_ELT (parmvec, i),
TREE_VEC_ELT (argvec, i),
UNIFY_ALLOW_NONE, explain_p))
return 1;
if (parm_variadic_p
&& unify_pack_expansion (tparms, targs,
parmvec, argvec,
DEDUCE_EXACT,
/*subr=*/true, explain_p))
return 1;
}
return 0;
}
/* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
template template parameters. Both PARM_PARMS and ARG_PARMS are
vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
or PARM_DECL.
Consider the example:
template <class T> class A;
template<template <class U> class TT> class B;
For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
the parameters to A, and OUTER_ARGS contains A. */
static int
coerce_template_template_parms (tree parm_parms,
tree arg_parms,
tsubst_flags_t complain,
tree in_decl,
tree outer_args)
{
int nparms, nargs, i;
tree parm, arg;
int variadic_p = 0;
gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
nparms = TREE_VEC_LENGTH (parm_parms);
nargs = TREE_VEC_LENGTH (arg_parms);
if (flag_new_ttp)
{
/* P0522R0: A template template-parameter P is at least as specialized as
a template template-argument A if, given the following rewrite to two
function templates, the function template corresponding to P is at
least as specialized as the function template corresponding to A
according to the partial ordering rules for function templates
([temp.func.order]). Given an invented class template X with the
template parameter list of A (including default arguments):
* Each of the two function templates has the same template parameters,
respectively, as P or A.
* Each function template has a single function parameter whose type is
a specialization of X with template arguments corresponding to the
template parameters from the respective function template where, for
each template parameter PP in the template parameter list of the
function template, a corresponding template argument AA is formed. If
PP declares a parameter pack, then AA is the pack expansion
PP... ([temp.variadic]); otherwise, AA is the id-expression PP.
If the rewrite produces an invalid type, then P is not at least as
specialized as A. */
/* So coerce P's args to apply to A's parms, and then deduce between A's
args and the converted args. If that succeeds, A is at least as
specialized as P, so they match.*/
tree pargs = template_parms_level_to_args (parm_parms);
pargs = add_outermost_template_args (outer_args, pargs);
++processing_template_decl;
pargs = coerce_template_parms (arg_parms, pargs, NULL_TREE, tf_none,
/*require_all*/true, /*use_default*/true);
--processing_template_decl;
if (pargs != error_mark_node)
{
tree targs = make_tree_vec (nargs);
tree aargs = template_parms_level_to_args (arg_parms);
if (!unify (arg_parms, targs, aargs, pargs, UNIFY_ALLOW_NONE,
/*explain*/false))
return 1;
}
}
/* Determine whether we have a parameter pack at the end of the
template template parameter's template parameter list. */
if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
{
parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
if (error_operand_p (parm))
return 0;
switch (TREE_CODE (parm))
{
case TEMPLATE_DECL:
case TYPE_DECL:
if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
variadic_p = 1;
break;
case PARM_DECL:
if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
variadic_p = 1;
break;
default:
gcc_unreachable ();
}
}
if (nargs != nparms
&& !(variadic_p && nargs >= nparms - 1))
return 0;
/* Check all of the template parameters except the parameter pack at
the end (if any). */
for (i = 0; i < nparms - variadic_p; ++i)
{
if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
|| TREE_VEC_ELT (arg_parms, i) == error_mark_node)
continue;
parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
if (!coerce_template_template_parm (parm, arg, complain, in_decl,
outer_args))
return 0;
}
if (variadic_p)
{
/* Check each of the template parameters in the template
argument against the template parameter pack at the end of
the template template parameter. */
if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
return 0;
parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
for (; i < nargs; ++i)
{
if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
continue;
arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
if (!coerce_template_template_parm (parm, arg, complain, in_decl,
outer_args))
return 0;
}
}
return 1;
}
/* Verifies that the deduced template arguments (in TARGS) for the
template template parameters (in TPARMS) represent valid bindings,
by comparing the template parameter list of each template argument
to the template parameter list of its corresponding template
template parameter, in accordance with DR150. This
routine can only be called after all template arguments have been
deduced. It will return TRUE if all of the template template
parameter bindings are okay, FALSE otherwise. */
bool
template_template_parm_bindings_ok_p (tree tparms, tree targs)
{
int i, ntparms = TREE_VEC_LENGTH (tparms);
bool ret = true;
/* We're dealing with template parms in this process. */
++processing_template_decl;
targs = INNERMOST_TEMPLATE_ARGS (targs);
for (i = 0; i < ntparms; ++i)
{
tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
tree targ = TREE_VEC_ELT (targs, i);
if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
{
tree packed_args = NULL_TREE;
int idx, len = 1;
if (ARGUMENT_PACK_P (targ))
{
/* Look inside the argument pack. */
packed_args = ARGUMENT_PACK_ARGS (targ);
len = TREE_VEC_LENGTH (packed_args);
}
for (idx = 0; idx < len; ++idx)
{
tree targ_parms = NULL_TREE;
if (packed_args)
/* Extract the next argument from the argument
pack. */
targ = TREE_VEC_ELT (packed_args, idx);
if (PACK_EXPANSION_P (targ))
/* Look at the pattern of the pack expansion. */
targ = PACK_EXPANSION_PATTERN (targ);
/* Extract the template parameters from the template
argument. */
if (TREE_CODE (targ) == TEMPLATE_DECL)
targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
/* Verify that we can coerce the template template
parameters from the template argument to the template
parameter. This requires an exact match. */
if (targ_parms
&& !coerce_template_template_parms
(DECL_INNERMOST_TEMPLATE_PARMS (tparm),
targ_parms,
tf_none,
tparm,
targs))
{
ret = false;
goto out;
}
}
}
}
out:
--processing_template_decl;
return ret;
}
/* Since type attributes aren't mangled, we need to strip them from
template type arguments. */
static tree
canonicalize_type_argument (tree arg, tsubst_flags_t complain)
{
if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
return arg;
bool removed_attributes = false;
tree canon = strip_typedefs (arg, &removed_attributes);
if (removed_attributes
&& (complain & tf_warning))
warning (OPT_Wignored_attributes,
"ignoring attributes on template argument %qT", arg);
return canon;
}
/* And from inside dependent non-type arguments like sizeof(Type). */
static tree
canonicalize_expr_argument (tree arg, tsubst_flags_t complain)
{
if (!arg || arg == error_mark_node)
return arg;
bool removed_attributes = false;
tree canon = strip_typedefs_expr (arg, &removed_attributes);
if (removed_attributes
&& (complain & tf_warning))
warning (OPT_Wignored_attributes,
"ignoring attributes in template argument %qE", arg);
return canon;
}
// A template declaration can be substituted for a constrained
// template template parameter only when the argument is more
// constrained than the parameter.
static bool
is_compatible_template_arg (tree parm, tree arg)
{
tree parm_cons = get_constraints (parm);
/* For now, allow constrained template template arguments
and unconstrained template template parameters. */
if (parm_cons == NULL_TREE)
return true;
tree arg_cons = get_constraints (arg);
// If the template parameter is constrained, we need to rewrite its
// constraints in terms of the ARG's template parameters. This ensures
// that all of the template parameter types will have the same depth.
//
// Note that this is only valid when coerce_template_template_parm is
// true for the innermost template parameters of PARM and ARG. In other
// words, because coercion is successful, this conversion will be valid.
if (parm_cons)
{
tree args = template_parms_to_args (DECL_TEMPLATE_PARMS (arg));
parm_cons = tsubst_constraint_info (parm_cons,
INNERMOST_TEMPLATE_ARGS (args),
tf_none, NULL_TREE);
if (parm_cons == error_mark_node)
return false;
}
return subsumes (parm_cons, arg_cons);
}
// Convert a placeholder argument into a binding to the original
// parameter. The original parameter is saved as the TREE_TYPE of
// ARG.
static inline tree
convert_wildcard_argument (tree parm, tree arg)
{
TREE_TYPE (arg) = parm;
return arg;
}
/* We can't fully resolve ARG given as a non-type template argument to TYPE,
because one of them is dependent. But we need to represent the
conversion for the benefit of cp_tree_equal. */
static tree
maybe_convert_nontype_argument (tree type, tree arg)
{
/* Auto parms get no conversion. */
if (type_uses_auto (type))
return arg;
/* We don't need or want to add this conversion now if we're going to use the
argument for deduction. */
if (value_dependent_expression_p (arg))
return arg;
type = cv_unqualified (type);
tree argtype = TREE_TYPE (arg);
if (same_type_p (type, argtype))
return arg;
arg = build1 (IMPLICIT_CONV_EXPR, type, arg);
IMPLICIT_CONV_EXPR_NONTYPE_ARG (arg) = true;
return arg;
}
/* Convert the indicated template ARG as necessary to match the
indicated template PARM. Returns the converted ARG, or
error_mark_node if the conversion was unsuccessful. Error and
warning messages are issued under control of COMPLAIN. This
conversion is for the Ith parameter in the parameter list. ARGS is
the full set of template arguments deduced so far. */
static tree
convert_template_argument (tree parm,
tree arg,
tree args,
tsubst_flags_t complain,
int i,
tree in_decl)
{
tree orig_arg;
tree val;
int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
if (parm == error_mark_node || error_operand_p (arg))
return error_mark_node;
/* Trivially convert placeholders. */
if (TREE_CODE (arg) == WILDCARD_DECL)
return convert_wildcard_argument (parm, arg);
if (arg == any_targ_node)
return arg;
if (TREE_CODE (arg) == TREE_LIST
&& TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
{
/* The template argument was the name of some
member function. That's usually
invalid, but static members are OK. In any
case, grab the underlying fields/functions
and issue an error later if required. */
orig_arg = TREE_VALUE (arg);
TREE_TYPE (arg) = unknown_type_node;
}
orig_arg = arg;
requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
requires_type = (TREE_CODE (parm) == TYPE_DECL
|| requires_tmpl_type);
/* When determining whether an argument pack expansion is a template,
look at the pattern. */
if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
arg = PACK_EXPANSION_PATTERN (arg);
/* Deal with an injected-class-name used as a template template arg. */
if (requires_tmpl_type && CLASS_TYPE_P (arg))
{
tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
if (TREE_CODE (t) == TEMPLATE_DECL)
{
if (cxx_dialect >= cxx11)
/* OK under DR 1004. */;
else if (complain & tf_warning_or_error)
pedwarn (input_location, OPT_Wpedantic, "injected-class-name %qD"
" used as template template argument", TYPE_NAME (arg));
else if (flag_pedantic_errors)
t = arg;
arg = t;
}
}
is_tmpl_type =
((TREE_CODE (arg) == TEMPLATE_DECL
&& TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
|| (requires_tmpl_type && TREE_CODE (arg) == TYPE_ARGUMENT_PACK)
|| TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
|| TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
if (is_tmpl_type
&& (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
|| TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
arg = TYPE_STUB_DECL (arg);
is_type = TYPE_P (arg) || is_tmpl_type;
if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
&& TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
{
if (TREE_CODE (TREE_OPERAND (arg, 1)) == BIT_NOT_EXPR)
{
if (complain & tf_error)
error ("invalid use of destructor %qE as a type", orig_arg);
return error_mark_node;
}
permerror (input_location,
"to refer to a type member of a template parameter, "
"use %<typename %E%>", orig_arg);
orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
TREE_OPERAND (arg, 1),
typename_type,
complain);
arg = orig_arg;
is_type = 1;
}
if (is_type != requires_type)
{
if (in_decl)
{
if (complain & tf_error)
{
error ("type/value mismatch at argument %d in template "
"parameter list for %qD",
i + 1, in_decl);
if (is_type)
inform (input_location,
" expected a constant of type %qT, got %qT",
TREE_TYPE (parm),
(DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
else if (requires_tmpl_type)
inform (input_location,
" expected a class template, got %qE", orig_arg);
else
inform (input_location,
" expected a type, got %qE", orig_arg);
}
}
return error_mark_node;
}
if (is_tmpl_type ^ requires_tmpl_type)
{
if (in_decl && (complain & tf_error))
{
error ("type/value mismatch at argument %d in template "
"parameter list for %qD",
i + 1, in_decl);
if (is_tmpl_type)
inform (input_location,
" expected a type, got %qT", DECL_NAME (arg));
else
inform (input_location,
" expected a class template, got %qT", orig_arg);
}
return error_mark_node;
}
if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
/* We already did the appropriate conversion when packing args. */
val = orig_arg;
else if (is_type)
{
if (requires_tmpl_type)
{
if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
/* The number of argument required is not known yet.
Just accept it for now. */
val = orig_arg;
else
{
tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
tree argparm;
/* Strip alias templates that are equivalent to another
template. */
arg = get_underlying_template (arg);
argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
if (coerce_template_template_parms (parmparm, argparm,
complain, in_decl,
args))
{
val = arg;
/* TEMPLATE_TEMPLATE_PARM node is preferred over
TEMPLATE_DECL. */
if (val != error_mark_node)
{
if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
val = TREE_TYPE (val);
if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
val = make_pack_expansion (val, complain);
}
}
else
{
if (in_decl && (complain & tf_error))
{
error ("type/value mismatch at argument %d in "
"template parameter list for %qD",
i + 1, in_decl);
inform (input_location,
" expected a template of type %qD, got %qT",
parm, orig_arg);
}
val = error_mark_node;
}
// Check that the constraints are compatible before allowing the
// substitution.
if (val != error_mark_node)
if (!is_compatible_template_arg (parm, arg))
{
if (in_decl && (complain & tf_error))
{
error ("constraint mismatch at argument %d in "
"template parameter list for %qD",
i + 1, in_decl);
inform (input_location, " expected %qD but got %qD",
parm, arg);
}
val = error_mark_node;
}
}
}
else
val = orig_arg;
/* We only form one instance of each template specialization.
Therefore, if we use a non-canonical variant (i.e., a
typedef), any future messages referring to the type will use
the typedef, which is confusing if those future uses do not
themselves also use the typedef. */
if (TYPE_P (val))
val = canonicalize_type_argument (val, complain);
}
else
{
tree t = TREE_TYPE (parm);
if (TEMPLATE_PARM_LEVEL (get_template_parm_index (parm))
> TMPL_ARGS_DEPTH (args))
/* We don't have enough levels of args to do any substitution. This
can happen in the context of -fnew-ttp-matching. */;
else if (tree a = type_uses_auto (t))
{
t = do_auto_deduction (t, arg, a, complain, adc_unify, args);
if (t == error_mark_node)
return error_mark_node;
}
else
t = tsubst (t, args, complain, in_decl);
if (invalid_nontype_parm_type_p (t, complain))
return error_mark_node;
if (t != TREE_TYPE (parm))
t = canonicalize_type_argument (t, complain);
if (!type_dependent_expression_p (orig_arg)
&& !uses_template_parms (t))
/* We used to call digest_init here. However, digest_init
will report errors, which we don't want when complain
is zero. More importantly, digest_init will try too
hard to convert things: for example, `0' should not be
converted to pointer type at this point according to
the standard. Accepting this is not merely an
extension, since deciding whether or not these
conversions can occur is part of determining which
function template to call, or whether a given explicit
argument specification is valid. */
val = convert_nontype_argument (t, orig_arg, complain);
else
{
val = canonicalize_expr_argument (orig_arg, complain);
val = maybe_convert_nontype_argument (t, val);
}
if (val == NULL_TREE)
val = error_mark_node;
else if (val == error_mark_node && (complain & tf_error))
error ("could not convert template argument %qE from %qT to %qT",
orig_arg, TREE_TYPE (orig_arg), t);
if (INDIRECT_REF_P (val))
{
/* Reject template arguments that are references to built-in
functions with no library fallbacks. */
const_tree inner = TREE_OPERAND (val, 0);
const_tree innertype = TREE_TYPE (inner);
if (innertype
&& TYPE_REF_P (innertype)
&& TREE_CODE (TREE_TYPE (innertype)) == FUNCTION_TYPE
&& TREE_OPERAND_LENGTH (inner) > 0
&& reject_gcc_builtin (TREE_OPERAND (inner, 0)))
return error_mark_node;
}
if (TREE_CODE (val) == SCOPE_REF)
{
/* Strip typedefs from the SCOPE_REF. */
tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
complain);
val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
QUALIFIED_NAME_IS_TEMPLATE (val));
}
}
return val;
}
/* Coerces the remaining template arguments in INNER_ARGS (from
ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
Returns the coerced argument pack. PARM_IDX is the position of this
parameter in the template parameter list. ARGS is the original
template argument list. */
static tree
coerce_template_parameter_pack (tree parms,
int parm_idx,
tree args,
tree inner_args,
int arg_idx,
tree new_args,
int* lost,
tree in_decl,
tsubst_flags_t complain)
{
tree parm = TREE_VEC_ELT (parms, parm_idx);
int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
tree packed_args;
tree argument_pack;
tree packed_parms = NULL_TREE;
if (arg_idx > nargs)
arg_idx = nargs;
if (tree packs = fixed_parameter_pack_p (TREE_VALUE (parm)))
{
/* When the template parameter is a non-type template parameter pack
or template template parameter pack whose type or template
parameters use parameter packs, we know exactly how many arguments
we are looking for. Build a vector of the instantiated decls for
these template parameters in PACKED_PARMS. */
/* We can't use make_pack_expansion here because it would interpret a
_DECL as a use rather than a declaration. */
tree decl = TREE_VALUE (parm);
tree exp = cxx_make_type (TYPE_PACK_EXPANSION);
SET_PACK_EXPANSION_PATTERN (exp, decl);
PACK_EXPANSION_PARAMETER_PACKS (exp) = packs;
SET_TYPE_STRUCTURAL_EQUALITY (exp);
TREE_VEC_LENGTH (args)--;
packed_parms = tsubst_pack_expansion (exp, args, complain, decl);
TREE_VEC_LENGTH (args)++;
if (packed_parms == error_mark_node)
return error_mark_node;
/* If we're doing a partial instantiation of a member template,
verify that all of the types used for the non-type
template parameter pack are, in fact, valid for non-type
template parameters. */
if (arg_idx < nargs
&& PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
{
int j, len = TREE_VEC_LENGTH (packed_parms);
for (j = 0; j < len; ++j)
{
tree t = TREE_VEC_ELT (packed_parms, j);
if (TREE_CODE (t) == PARM_DECL
&& invalid_nontype_parm_type_p (TREE_TYPE (t), complain))
return error_mark_node;
}
/* We don't know how many args we have yet, just
use the unconverted ones for now. */
return NULL_TREE;
}
packed_args = make_tree_vec (TREE_VEC_LENGTH (packed_parms));
}
/* Check if we have a placeholder pack, which indicates we're
in the context of a introduction list. In that case we want
to match this pack to the single placeholder. */
else if (arg_idx < nargs
&& TREE_CODE (TREE_VEC_ELT (inner_args, arg_idx)) == WILDCARD_DECL
&& WILDCARD_PACK_P (TREE_VEC_ELT (inner_args, arg_idx)))
{
nargs = arg_idx + 1;
packed_args = make_tree_vec (1);
}
else
packed_args = make_tree_vec (nargs - arg_idx);
/* Convert the remaining arguments, which will be a part of the
parameter pack "parm". */
int first_pack_arg = arg_idx;
for (; arg_idx < nargs; ++arg_idx)
{
tree arg = TREE_VEC_ELT (inner_args, arg_idx);
tree actual_parm = TREE_VALUE (parm);
int pack_idx = arg_idx - first_pack_arg;
if (packed_parms)
{
/* Once we've packed as many args as we have types, stop. */
if (pack_idx >= TREE_VEC_LENGTH (packed_parms))
break;
else if (PACK_EXPANSION_P (arg))
/* We don't know how many args we have yet, just
use the unconverted ones for now. */
return NULL_TREE;
else
actual_parm = TREE_VEC_ELT (packed_parms, pack_idx);
}
if (arg == error_mark_node)
{
if (complain & tf_error)
error ("template argument %d is invalid", arg_idx + 1);
}
else
arg = convert_template_argument (actual_parm,
arg, new_args, complain, parm_idx,
in_decl);
if (arg == error_mark_node)
(*lost)++;
TREE_VEC_ELT (packed_args, pack_idx) = arg;
}
if (arg_idx - first_pack_arg < TREE_VEC_LENGTH (packed_args)
&& TREE_VEC_LENGTH (packed_args) > 0)
{
if (complain & tf_error)
error ("wrong number of template arguments (%d, should be %d)",
arg_idx - first_pack_arg, TREE_VEC_LENGTH (packed_args));
return error_mark_node;
}
if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
|| TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
else
{
argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
TREE_CONSTANT (argument_pack) = 1;
}
SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
if (CHECKING_P)
SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
TREE_VEC_LENGTH (packed_args));
return argument_pack;
}
/* Returns the number of pack expansions in the template argument vector
ARGS. */
static int
pack_expansion_args_count (tree args)
{
int i;
int count = 0;
if (args)
for (i = 0; i < TREE_VEC_LENGTH (args); ++i)
{
tree elt = TREE_VEC_ELT (args, i);
if (elt && PACK_EXPANSION_P (elt))
++count;
}
return count;
}
/* Convert all template arguments to their appropriate types, and
return a vector containing the innermost resulting template
arguments. If any error occurs, return error_mark_node. Error and
warning messages are issued under control of COMPLAIN.
If REQUIRE_ALL_ARGS is false, argument deduction will be performed
for arguments not specified in ARGS. Otherwise, if
USE_DEFAULT_ARGS is true, default arguments will be used to fill in
unspecified arguments. If REQUIRE_ALL_ARGS is true, but
USE_DEFAULT_ARGS is false, then all arguments must be specified in
ARGS. */
static tree
coerce_template_parms (tree parms,
tree args,
tree in_decl,
tsubst_flags_t complain,
bool require_all_args,
bool use_default_args)
{
int nparms, nargs, parm_idx, arg_idx, lost = 0;
tree orig_inner_args;
tree inner_args;
tree new_args;
tree new_inner_args;
/* When used as a boolean value, indicates whether this is a
variadic template parameter list. Since it's an int, we can also
subtract it from nparms to get the number of non-variadic
parameters. */
int variadic_p = 0;
int variadic_args_p = 0;
int post_variadic_parms = 0;
/* Adjustment to nparms for fixed parameter packs. */
int fixed_pack_adjust = 0;
int fixed_packs = 0;
int missing = 0;
/* Likewise for parameters with default arguments. */
int default_p = 0;
if (args == error_mark_node)
return error_mark_node;
nparms = TREE_VEC_LENGTH (parms);
/* Determine if there are any parameter packs or default arguments. */
for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
{
tree parm = TREE_VEC_ELT (parms, parm_idx);
if (variadic_p)
++post_variadic_parms;
if (template_parameter_pack_p (TREE_VALUE (parm)))
++variadic_p;
if (TREE_PURPOSE (parm))
++default_p;
}
inner_args = orig_inner_args = INNERMOST_TEMPLATE_ARGS (args);
/* If there are no parameters that follow a parameter pack, we need to
expand any argument packs so that we can deduce a parameter pack from
some non-packed args followed by an argument pack, as in variadic85.C.
If there are such parameters, we need to leave argument packs intact
so the arguments are assigned properly. This can happen when dealing
with a nested class inside a partial specialization of a class
template, as in variadic92.C, or when deducing a template parameter pack
from a sub-declarator, as in variadic114.C. */
if (!post_variadic_parms)
inner_args = expand_template_argument_pack (inner_args);
/* Count any pack expansion args. */
variadic_args_p = pack_expansion_args_count (inner_args);
nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
if ((nargs - variadic_args_p > nparms && !variadic_p)
|| (nargs < nparms - variadic_p
&& require_all_args
&& !variadic_args_p
&& (!use_default_args
|| (TREE_VEC_ELT (parms, nargs) != error_mark_node
&& !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
{
bad_nargs:
if (complain & tf_error)
{
if (variadic_p || default_p)
{
nparms -= variadic_p + default_p;
error ("wrong number of template arguments "
"(%d, should be at least %d)", nargs, nparms);
}
else
error ("wrong number of template arguments "
"(%d, should be %d)", nargs, nparms);
if (in_decl)
inform (DECL_SOURCE_LOCATION (in_decl),
"provided for %qD", in_decl);
}
return error_mark_node;
}
/* We can't pass a pack expansion to a non-pack parameter of an alias
template (DR 1430). */
else if (in_decl
&& (DECL_ALIAS_TEMPLATE_P (in_decl)
|| concept_template_p (in_decl))
&& variadic_args_p
&& nargs - variadic_args_p < nparms - variadic_p)
{
if (complain & tf_error)
{
for (int i = 0; i < TREE_VEC_LENGTH (inner_args); ++i)
{
tree arg = TREE_VEC_ELT (inner_args, i);
tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
if (PACK_EXPANSION_P (arg)
&& !template_parameter_pack_p (parm))
{
if (DECL_ALIAS_TEMPLATE_P (in_decl))
error_at (location_of (arg),
"pack expansion argument for non-pack parameter "
"%qD of alias template %qD", parm, in_decl);
else
error_at (location_of (arg),
"pack expansion argument for non-pack parameter "
"%qD of concept %qD", parm, in_decl);
inform (DECL_SOURCE_LOCATION (parm), "declared here");
goto found;
}
}
gcc_unreachable ();
found:;
}
return error_mark_node;
}
/* We need to evaluate the template arguments, even though this
template-id may be nested within a "sizeof". */
cp_evaluated ev;
new_inner_args = make_tree_vec (nparms);
new_args = add_outermost_template_args (args, new_inner_args);
int pack_adjust = 0;
for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
{
tree arg;
tree parm;
/* Get the Ith template parameter. */
parm = TREE_VEC_ELT (parms, parm_idx);
if (parm == error_mark_node)
{
TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
continue;
}
/* Calculate the next argument. */
if (arg_idx < nargs)
arg = TREE_VEC_ELT (inner_args, arg_idx);
else
arg = NULL_TREE;
if (template_parameter_pack_p (TREE_VALUE (parm))
&& (arg || require_all_args || !(complain & tf_partial))
&& !(arg && ARGUMENT_PACK_P (arg)))
{
/* Some arguments will be placed in the
template parameter pack PARM. */
arg = coerce_template_parameter_pack (parms, parm_idx, args,
inner_args, arg_idx,
new_args, &lost,
in_decl, complain);
if (arg == NULL_TREE)
{
/* We don't know how many args we have yet, just use the
unconverted (and still packed) ones for now. */
new_inner_args = orig_inner_args;
arg_idx = nargs;
break;
}
TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
/* Store this argument. */
if (arg == error_mark_node)
{
lost++;
/* We are done with all of the arguments. */
arg_idx = nargs;
break;
}
else
{
pack_adjust = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg)) - 1;
arg_idx += pack_adjust;
if (fixed_parameter_pack_p (TREE_VALUE (parm)))
{
++fixed_packs;
fixed_pack_adjust += pack_adjust;
}
}
continue;
}
else if (arg)
{
if (PACK_EXPANSION_P (arg))
{
/* "If every valid specialization of a variadic template
requires an empty template parameter pack, the template is
ill-formed, no diagnostic required." So check that the
pattern works with this parameter. */
tree pattern = PACK_EXPANSION_PATTERN (arg);
tree conv = convert_template_argument (TREE_VALUE (parm),
pattern, new_args,
complain, parm_idx,
in_decl);
if (conv == error_mark_node)
{
if (complain & tf_error)
inform (input_location, "so any instantiation with a "
"non-empty parameter pack would be ill-formed");
++lost;
}
else if (TYPE_P (conv) && !TYPE_P (pattern))
/* Recover from missing typename. */
TREE_VEC_ELT (inner_args, arg_idx)
= make_pack_expansion (conv, complain);
/* We don't know how many args we have yet, just
use the unconverted ones for now. */
new_inner_args = inner_args;
arg_idx = nargs;
break;
}
}
else if (require_all_args)
{
/* There must be a default arg in this case. */
arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
complain, in_decl);
/* The position of the first default template argument,
is also the number of non-defaulted arguments in NEW_INNER_ARGS.
Record that. */
if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
arg_idx - pack_adjust);
}
else
break;
if (arg == error_mark_node)
{
if (complain & tf_error)
error ("template argument %d is invalid", arg_idx + 1);
}
else if (!arg)
{
/* This can occur if there was an error in the template
parameter list itself (which we would already have
reported) that we are trying to recover from, e.g., a class
template with a parameter list such as
template<typename..., typename> (cpp0x/variadic150.C). */
++lost;
/* This can also happen with a fixed parameter pack (71834). */
if (arg_idx >= nargs)
++missing;
}
else
arg = convert_template_argument (TREE_VALUE (parm),
arg, new_args, complain,
parm_idx, in_decl);
if (arg == error_mark_node)
lost++;
TREE_VEC_ELT (new_inner_args, arg_idx - pack_adjust) = arg;
}
if (missing || arg_idx < nargs - variadic_args_p)
{
/* If we had fixed parameter packs, we didn't know how many arguments we
actually needed earlier; now we do. */
nparms += fixed_pack_adjust;
variadic_p -= fixed_packs;
goto bad_nargs;
}
if (arg_idx < nargs)
{
/* We had some pack expansion arguments that will only work if the packs
are empty, but wait until instantiation time to complain.
See variadic-ttp3.C. */
int len = nparms + (nargs - arg_idx);
tree args = make_tree_vec (len);
int i = 0;
for (; i < nparms; ++i)
TREE_VEC_ELT (args, i) = TREE_VEC_ELT (new_inner_args, i);
for (; i < len; ++i, ++arg_idx)
TREE_VEC_ELT (args, i) = TREE_VEC_ELT (inner_args,
arg_idx - pack_adjust);
new_inner_args = args;
}
if (lost)
{
gcc_assert (!(complain & tf_error) || seen_error ());
return error_mark_node;
}
if (CHECKING_P && !NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
TREE_VEC_LENGTH (new_inner_args));
return new_inner_args;
}
/* Convert all template arguments to their appropriate types, and
return a vector containing the innermost resulting template
arguments. If any error occurs, return error_mark_node. Error and
warning messages are not issued.
Note that no function argument deduction is performed, and default
arguments are used to fill in unspecified arguments. */
tree
coerce_template_parms (tree parms, tree args, tree in_decl)
{
return coerce_template_parms (parms, args, in_decl, tf_none, true, true);
}
/* Convert all template arguments to their appropriate type, and
instantiate default arguments as needed. This returns a vector
containing the innermost resulting template arguments, or
error_mark_node if unsuccessful. */
tree
coerce_template_parms (tree parms, tree args, tree in_decl,
tsubst_flags_t complain)
{
return coerce_template_parms (parms, args, in_decl, complain, true, true);
}
/* Like coerce_template_parms. If PARMS represents all template
parameters levels, this function returns a vector of vectors
representing all the resulting argument levels. Note that in this
case, only the innermost arguments are coerced because the
outermost ones are supposed to have been coerced already.
Otherwise, if PARMS represents only (the innermost) vector of
parameters, this function returns a vector containing just the
innermost resulting arguments. */
static tree
coerce_innermost_template_parms (tree parms,
tree args,
tree in_decl,
tsubst_flags_t complain,
bool require_all_args,
bool use_default_args)
{
int parms_depth = TMPL_PARMS_DEPTH (parms);
int args_depth = TMPL_ARGS_DEPTH (args);
tree coerced_args;
if (parms_depth > 1)
{
coerced_args = make_tree_vec (parms_depth);
tree level;
int cur_depth;
for (level = parms, cur_depth = parms_depth;
parms_depth > 0 && level != NULL_TREE;
level = TREE_CHAIN (level), --cur_depth)
{
tree l;
if (cur_depth == args_depth)
l = coerce_template_parms (TREE_VALUE (level),
args, in_decl, complain,
require_all_args,
use_default_args);
else
l = TMPL_ARGS_LEVEL (args, cur_depth);
if (l == error_mark_node)
return error_mark_node;
SET_TMPL_ARGS_LEVEL (coerced_args, cur_depth, l);
}
}
else
coerced_args = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parms),
args, in_decl, complain,
require_all_args,
use_default_args);
return coerced_args;
}
/* Returns 1 if template args OT and NT are equivalent. */
int
template_args_equal (tree ot, tree nt, bool partial_order /* = false */)
{
if (nt == ot)
return 1;
if (nt == NULL_TREE || ot == NULL_TREE)
return false;
if (nt == any_targ_node || ot == any_targ_node)
return true;
if (TREE_CODE (nt) == TREE_VEC)
/* For member templates */
return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
else if (PACK_EXPANSION_P (ot))
return (PACK_EXPANSION_P (nt)
&& template_args_equal (PACK_EXPANSION_PATTERN (ot),
PACK_EXPANSION_PATTERN (nt))
&& template_args_equal (PACK_EXPANSION_EXTRA_ARGS (ot),
PACK_EXPANSION_EXTRA_ARGS (nt)));
else if (ARGUMENT_PACK_P (ot))
{
int i, len;
tree opack, npack;
if (!ARGUMENT_PACK_P (nt))
return 0;
opack = ARGUMENT_PACK_ARGS (ot);
npack = ARGUMENT_PACK_ARGS (nt);
len = TREE_VEC_LENGTH (opack);
if (TREE_VEC_LENGTH (npack) != len)
return 0;
for (i = 0; i < len; ++i)
if (!template_args_equal (TREE_VEC_ELT (opack, i),
TREE_VEC_ELT (npack, i)))
return 0;
return 1;
}
else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
gcc_unreachable ();
else if (TYPE_P (nt))
{
if (!TYPE_P (ot))
return false;
/* Don't treat an alias template specialization with dependent
arguments as equivalent to its underlying type when used as a
template argument; we need them to be distinct so that we
substitute into the specialization arguments at instantiation
time. And aliases can't be equivalent without being ==, so
we don't need to look any deeper.
During partial ordering, however, we need to treat them normally so
that we can order uses of the same alias with different
cv-qualification (79960). */
if (!partial_order
&& (TYPE_ALIAS_P (nt) || TYPE_ALIAS_P (ot)))
return false;
else
return same_type_p (ot, nt);
}
else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
return 0;
else
{
/* Try to treat a template non-type argument that has been converted
to the parameter type as equivalent to one that hasn't yet. */
for (enum tree_code code1 = TREE_CODE (ot);
CONVERT_EXPR_CODE_P (code1)
|| code1 == NON_LVALUE_EXPR;
code1 = TREE_CODE (ot))
ot = TREE_OPERAND (ot, 0);
for (enum tree_code code2 = TREE_CODE (nt);
CONVERT_EXPR_CODE_P (code2)
|| code2 == NON_LVALUE_EXPR;
code2 = TREE_CODE (nt))
nt = TREE_OPERAND (nt, 0);
return cp_tree_equal (ot, nt);
}
}
/* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
NEWARG_PTR with the offending arguments if they are non-NULL. */
int
comp_template_args (tree oldargs, tree newargs,
tree *oldarg_ptr, tree *newarg_ptr,
bool partial_order)
{
int i;
if (oldargs == newargs)
return 1;
if (!oldargs || !newargs)
return 0;
if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
return 0;
for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
{
tree nt = TREE_VEC_ELT (newargs, i);
tree ot = TREE_VEC_ELT (oldargs, i);
if (! template_args_equal (ot, nt, partial_order))
{
if (oldarg_ptr != NULL)
*oldarg_ptr = ot;
if (newarg_ptr != NULL)
*newarg_ptr = nt;
return 0;
}
}
return 1;
}
inline bool
comp_template_args_porder (tree oargs, tree nargs)
{
return comp_template_args (oargs, nargs, NULL, NULL, true);
}
/* Implement a freelist interface for objects of type T.
Head is a separate object, rather than a regular member, so that we
can define it as a GTY deletable pointer, which is highly
desirable. A data member could be declared that way, but then the
containing object would implicitly get GTY((user)), which would
prevent us from instantiating freelists as global objects.
Although this way we can create freelist global objects, they're
such thin wrappers that instantiating temporaries at every use
loses nothing and saves permanent storage for the freelist object.
Member functions next, anew, poison and reinit have default
implementations that work for most of the types we're interested
in, but if they don't work for some type, they should be explicitly
specialized. See the comments before them for requirements, and
the example specializations for the tree_list_freelist. */
template <typename T>
class freelist
{
/* Return the next object in a chain. We could just do type
punning, but if we access the object with its underlying type, we
avoid strict-aliasing trouble. This needs only work between
poison and reinit. */
static T *&next (T *obj) { return obj->next; }
/* Return a newly allocated, uninitialized or minimally-initialized
object of type T. Any initialization performed by anew should
either remain across the life of the object and the execution of
poison, or be redone by reinit. */
static T *anew () { return ggc_alloc<T> (); }
/* Optionally scribble all over the bits holding the object, so that
they become (mostly?) uninitialized memory. This is called while
preparing to make the object part of the free list. */
static void poison (T *obj) {
T *p ATTRIBUTE_UNUSED = obj;
T **q ATTRIBUTE_UNUSED = &next (obj);
#ifdef ENABLE_GC_CHECKING
/* Poison the data, to indicate the data is garbage. */
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (p, sizeof (*p)));
memset (p, 0xa5, sizeof (*p));
#endif
/* Let valgrind know the object is free. */
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (p, sizeof (*p)));
/* Let valgrind know the next portion of the object is available,
but uninitialized. */
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (q, sizeof (*q)));
}
/* Bring an object that underwent at least one lifecycle after anew
and before the most recent free and poison, back to a usable
state, reinitializing whatever is needed for it to be
functionally equivalent to an object just allocated and returned
by anew. This may poison or clear the next field, used by
freelist housekeeping after poison was called. */
static void reinit (T *obj) {
T **q ATTRIBUTE_UNUSED = &next (obj);
#ifdef ENABLE_GC_CHECKING
memset (q, 0xa5, sizeof (*q));
#endif
/* Let valgrind know the entire object is available, but
uninitialized. */
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (obj, sizeof (*obj)));
}
/* Reference a GTY-deletable pointer that points to the first object
in the free list proper. */
T *&head;
public:
/* Construct a freelist object chaining objects off of HEAD. */
freelist (T *&head) : head(head) {}
/* Add OBJ to the free object list. The former head becomes OBJ's
successor. */
void free (T *obj)
{
poison (obj);
next (obj) = head;
head = obj;
}
/* Take an object from the free list, if one is available, or
allocate a new one. Objects taken from the free list should be
regarded as filled with garbage, except for bits that are
configured to be preserved across free and alloc. */
T *alloc ()
{
if (head)
{
T *obj = head;
head = next (head);
reinit (obj);
return obj;
}
else
return anew ();
}
};
/* Explicitly specialize the interfaces for freelist<tree_node>: we
want to allocate a TREE_LIST using the usual interface, and ensure
TREE_CHAIN remains functional. Alas, we have to duplicate a bit of
build_tree_list logic in reinit, so this could go out of sync. */
template <>
inline tree &
freelist<tree_node>::next (tree obj)
{
return TREE_CHAIN (obj);
}
template <>
inline tree
freelist<tree_node>::anew ()
{
return build_tree_list (NULL, NULL);
}
template <>
inline void
freelist<tree_node>::poison (tree obj ATTRIBUTE_UNUSED)
{
int size ATTRIBUTE_UNUSED = sizeof (tree_list);
tree p ATTRIBUTE_UNUSED = obj;
tree_base *b ATTRIBUTE_UNUSED = &obj->base;
tree *q ATTRIBUTE_UNUSED = &next (obj);
#ifdef ENABLE_GC_CHECKING
gcc_checking_assert (TREE_CODE (obj) == TREE_LIST);
/* Poison the data, to indicate the data is garbage. */
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (p, size));
memset (p, 0xa5, size);
#endif
/* Let valgrind know the object is free. */
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS (p, size));
/* But we still want to use the TREE_CODE and TREE_CHAIN parts. */
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (b, sizeof (*b)));
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (q, sizeof (*q)));
#ifdef ENABLE_GC_CHECKING
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (b, sizeof (*b)));
/* Keep TREE_CHAIN functional. */
TREE_SET_CODE (obj, TREE_LIST);
#else
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (b, sizeof (*b)));
#endif
}
template <>
inline void
freelist<tree_node>::reinit (tree obj ATTRIBUTE_UNUSED)
{
tree_base *b ATTRIBUTE_UNUSED = &obj->base;
#ifdef ENABLE_GC_CHECKING
gcc_checking_assert (TREE_CODE (obj) == TREE_LIST);
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (obj, sizeof (tree_list)));
memset (obj, 0, sizeof (tree_list));
#endif
/* Let valgrind know the entire object is available, but
uninitialized. */
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_UNDEFINED (obj, sizeof (tree_list)));
#ifdef ENABLE_GC_CHECKING
TREE_SET_CODE (obj, TREE_LIST);
#else
VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (b, sizeof (*b)));
#endif
}
/* Point to the first object in the TREE_LIST freelist. */
static GTY((deletable)) tree tree_list_freelist_head;
/* Return the/an actual TREE_LIST freelist. */
static inline freelist<tree_node>
tree_list_freelist ()
{
return tree_list_freelist_head;
}
/* Point to the first object in the tinst_level freelist. */
static GTY((deletable)) tinst_level *tinst_level_freelist_head;
/* Return the/an actual tinst_level freelist. */
static inline freelist<tinst_level>
tinst_level_freelist ()
{
return tinst_level_freelist_head;
}
/* Point to the first object in the pending_template freelist. */
static GTY((deletable)) pending_template *pending_template_freelist_head;
/* Return the/an actual pending_template freelist. */
static inline freelist<pending_template>
pending_template_freelist ()
{
return pending_template_freelist_head;
}
/* Build the TREE_LIST object out of a split list, store it
permanently, and return it. */
tree
tinst_level::to_list ()
{
gcc_assert (split_list_p ());
tree ret = tree_list_freelist ().alloc ();
TREE_PURPOSE (ret) = tldcl;
TREE_VALUE (ret) = targs;
tldcl = ret;
targs = NULL;
gcc_assert (tree_list_p ());
return ret;
}
const unsigned short tinst_level::refcount_infinity;
/* Increment OBJ's refcount unless it is already infinite. */
static tinst_level *
inc_refcount_use (tinst_level *obj)
{
if (obj && obj->refcount != tinst_level::refcount_infinity)
++obj->refcount;
return obj;
}
/* Release storage for OBJ and node, if it's a TREE_LIST. */
void
tinst_level::free (tinst_level *obj)
{
if (obj->tree_list_p ())
tree_list_freelist ().free (obj->get_node ());
tinst_level_freelist ().free (obj);
}
/* Decrement OBJ's refcount if not infinite. If it reaches zero, release
OBJ's DECL and OBJ, and start over with the tinst_level object that
used to be referenced by OBJ's NEXT. */
static void
dec_refcount_use (tinst_level *obj)
{
while (obj
&& obj->refcount != tinst_level::refcount_infinity
&& !--obj->refcount)
{
tinst_level *next = obj->next;
tinst_level::free (obj);
obj = next;
}
}
/* Modify PTR so that it points to OBJ, adjusting the refcounts of OBJ
and of the former PTR. Omitting the second argument is equivalent
to passing (T*)NULL; this is allowed because passing the
zero-valued integral constant NULL confuses type deduction and/or
overload resolution. */
template <typename T>
static void
set_refcount_ptr (T *& ptr, T *obj = NULL)
{
T *save = ptr;
ptr = inc_refcount_use (obj);
dec_refcount_use (save);
}
static void
add_pending_template (tree d)
{
tree ti = (TYPE_P (d)
? CLASSTYPE_TEMPLATE_INFO (d)
: DECL_TEMPLATE_INFO (d));
struct pending_template *pt;
int level;
if (TI_PENDING_TEMPLATE_FLAG (ti))
return;
/* We are called both from instantiate_decl, where we've already had a
tinst_level pushed, and instantiate_template, where we haven't.
Compensate. */
gcc_assert (TREE_CODE (d) != TREE_LIST);
level = !current_tinst_level
|| current_tinst_level->maybe_get_node () != d;
if (level)
push_tinst_level (d);
pt = pending_template_freelist ().alloc ();
pt->next = NULL;
pt->tinst = NULL;
set_refcount_ptr (pt->tinst, current_tinst_level);
if (last_pending_template)
last_pending_template->next = pt;
else
pending_templates = pt;
last_pending_template = pt;
TI_PENDING_TEMPLATE_FLAG (ti) = 1;
if (level)
pop_tinst_level ();
}
/* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
ARGLIST. Valid choices for FNS are given in the cp-tree.def
documentation for TEMPLATE_ID_EXPR. */
tree
lookup_template_function (tree fns, tree arglist)
{
if (fns == error_mark_node || arglist == error_mark_node)
return error_mark_node;
gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
if (!is_overloaded_fn (fns) && !identifier_p (fns))
{
error ("%q#D is not a function template", fns);
return error_mark_node;
}
if (BASELINK_P (fns))
{
BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
unknown_type_node,
BASELINK_FUNCTIONS (fns),
arglist);
return fns;
}
return build2 (TEMPLATE_ID_EXPR, unknown_type_node, fns, arglist);
}
/* Within the scope of a template class S<T>, the name S gets bound
(in build_self_reference) to a TYPE_DECL for the class, not a
TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
or one of its enclosing classes, and that type is a template,
return the associated TEMPLATE_DECL. Otherwise, the original
DECL is returned.
Also handle the case when DECL is a TREE_LIST of ambiguous
injected-class-names from different bases. */
tree
maybe_get_template_decl_from_type_decl (tree decl)
{
if (decl == NULL_TREE)
return decl;
/* DR 176: A lookup that finds an injected-class-name (10.2
[class.member.lookup]) can result in an ambiguity in certain cases
(for example, if it is found in more than one base class). If all of
the injected-class-names that are found refer to specializations of
the same class template, and if the name is followed by a
template-argument-list, the reference refers to the class template
itself and not a specialization thereof, and is not ambiguous. */
if (TREE_CODE (decl) == TREE_LIST)
{
tree t, tmpl = NULL_TREE;
for (t = decl; t; t = TREE_CHAIN (t))
{
tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
if (!tmpl)
tmpl = elt;
else if (tmpl != elt)
break;
}
if (tmpl && t == NULL_TREE)
return tmpl;
else
return decl;
}
return (decl != NULL_TREE
&& DECL_SELF_REFERENCE_P (decl)
&& CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
}
/* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
parameters, find the desired type.
D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
IN_DECL, if non-NULL, is the template declaration we are trying to
instantiate.
If ENTERING_SCOPE is nonzero, we are about to enter the scope of
the class we are looking up.
Issue error and warning messages under control of COMPLAIN.
If the template class is really a local class in a template
function, then the FUNCTION_CONTEXT is the function in which it is
being instantiated.
??? Note that this function is currently called *twice* for each
template-id: the first time from the parser, while creating the
incomplete type (finish_template_type), and the second type during the
real instantiation (instantiate_template_class). This is surely something
that we want to avoid. It also causes some problems with argument
coercion (see convert_nontype_argument for more information on this). */
static tree
lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
int entering_scope, tsubst_flags_t complain)
{
tree templ = NULL_TREE, parmlist;
tree t;
spec_entry **slot;
spec_entry *entry;
spec_entry elt;
hashval_t hash;
if (identifier_p (d1))
{
tree value = innermost_non_namespace_value (d1);
if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
templ = value;
else
{
if (context)
push_decl_namespace (context);
templ = lookup_name (d1);
templ = maybe_get_template_decl_from_type_decl (templ);
if (context)
pop_decl_namespace ();
}
if (templ)
context = DECL_CONTEXT (templ);
}
else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
{
tree type = TREE_TYPE (d1);
/* If we are declaring a constructor, say A<T>::A<T>, we will get
an implicit typename for the second A. Deal with it. */
if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
type = TREE_TYPE (type);
if (CLASSTYPE_TEMPLATE_INFO (type))
{
templ = CLASSTYPE_TI_TEMPLATE (type);
d1 = DECL_NAME (templ);
}
}
else if (TREE_CODE (d1) == ENUMERAL_TYPE
|| (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
{
templ = TYPE_TI_TEMPLATE (d1);
d1 = DECL_NAME (templ);
}
else if (DECL_TYPE_TEMPLATE_P (d1))
{
templ = d1;
d1 = DECL_NAME (templ);
context = DECL_CONTEXT (templ);
}
else if (DECL_TEMPLATE_TEMPLATE_PARM_P (d1))
{
templ = d1;
d1 = DECL_NAME (templ);
}
/* Issue an error message if we didn't find a template. */
if (! templ)
{
if (complain & tf_error)
error ("%qT is not a template", d1);
return error_mark_node;
}
if (TREE_CODE (templ) != TEMPLATE_DECL
/* Make sure it's a user visible template, if it was named by
the user. */
|| ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
&& !PRIMARY_TEMPLATE_P (templ)))
{
if (complain & tf_error)
{
error ("non-template type %qT used as a template", d1);
if (in_decl)
error ("for template declaration %q+D", in_decl);
}
return error_mark_node;
}
complain &= ~tf_user;
/* An alias that just changes the name of a template is equivalent to the
other template, so if any of the arguments are pack expansions, strip
the alias to avoid problems with a pack expansion passed to a non-pack
alias template parameter (DR 1430). */
if (pack_expansion_args_count (INNERMOST_TEMPLATE_ARGS (arglist)))
templ = get_underlying_template (templ);
if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
{
tree parm;
tree arglist2 = coerce_template_args_for_ttp (templ, arglist, complain);
if (arglist2 == error_mark_node
|| (!uses_template_parms (arglist2)
&& check_instantiated_args (templ, arglist2, complain)))
return error_mark_node;
parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
return parm;
}
else
{
tree template_type = TREE_TYPE (templ);
tree gen_tmpl;
tree type_decl;
tree found = NULL_TREE;
int arg_depth;
int parm_depth;
int is_dependent_type;
int use_partial_inst_tmpl = false;
if (template_type == error_mark_node)
/* An error occurred while building the template TEMPL, and a
diagnostic has most certainly been emitted for that
already. Let's propagate that error. */
return error_mark_node;
gen_tmpl = most_general_template (templ);
parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
parm_depth = TMPL_PARMS_DEPTH (parmlist);
arg_depth = TMPL_ARGS_DEPTH (arglist);
if (arg_depth == 1 && parm_depth > 1)
{
/* We've been given an incomplete set of template arguments.
For example, given:
template <class T> struct S1 {
template <class U> struct S2 {};
template <class U> struct S2<U*> {};
};
we will be called with an ARGLIST of `U*', but the
TEMPLATE will be `template <class T> template
<class U> struct S1<T>::S2'. We must fill in the missing
arguments. */
tree ti = TYPE_TEMPLATE_INFO_MAYBE_ALIAS (TREE_TYPE (templ));
arglist = add_outermost_template_args (TI_ARGS (ti), arglist);
arg_depth = TMPL_ARGS_DEPTH (arglist);
}
/* Now we should have enough arguments. */
gcc_assert (parm_depth == arg_depth);
/* From here on, we're only interested in the most general
template. */
/* Calculate the BOUND_ARGS. These will be the args that are
actually tsubst'd into the definition to create the
instantiation. */
arglist = coerce_innermost_template_parms (parmlist, arglist, gen_tmpl,
complain,
/*require_all_args=*/true,
/*use_default_args=*/true);
if (arglist == error_mark_node)
/* We were unable to bind the arguments. */
return error_mark_node;
/* In the scope of a template class, explicit references to the
template class refer to the type of the template, not any
instantiation of it. For example, in:
template <class T> class C { void f(C<T>); }
the `C<T>' is just the same as `C'. Outside of the
class, however, such a reference is an instantiation. */
if (entering_scope
|| !PRIMARY_TEMPLATE_P (gen_tmpl)
|| currently_open_class (template_type))
{
tree tinfo = TYPE_TEMPLATE_INFO (template_type);
if (tinfo && comp_template_args (TI_ARGS (tinfo), arglist))
return template_type;
}
/* If we already have this specialization, return it. */
elt.tmpl = gen_tmpl;
elt.args = arglist;
elt.spec = NULL_TREE;
hash = spec_hasher::hash (&elt);
entry = type_specializations->find_with_hash (&elt, hash);
if (entry)
return entry->spec;
/* If the the template's constraints are not satisfied,
then we cannot form a valid type.
Note that the check is deferred until after the hash
lookup. This prevents redundant checks on previously
instantiated specializations. */
if (flag_concepts && !constraints_satisfied_p (gen_tmpl, arglist))
{
if (complain & tf_error)
{
auto_diagnostic_group d;
error ("template constraint failure");
diagnose_constraints (input_location, gen_tmpl, arglist);
}
return error_mark_node;
}
is_dependent_type = uses_template_parms (arglist);
/* If the deduced arguments are invalid, then the binding
failed. */
if (!is_dependent_type
&& check_instantiated_args (gen_tmpl,
INNERMOST_TEMPLATE_ARGS (arglist),
complain))
return error_mark_node;
if (!is_dependent_type
&& !PRIMARY_TEMPLATE_P (gen_tmpl)
&& !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
&& TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
{
found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
DECL_NAME (gen_tmpl),
/*tag_scope=*/ts_global);
return found;
}
context = DECL_CONTEXT (gen_tmpl);
if (context && TYPE_P (context))
{
context = tsubst_aggr_type (context, arglist, complain, in_decl, true);
context = complete_type (context);
}
else
context = tsubst (context, arglist, complain, in_decl);
if (context == error_mark_node)
return error_mark_node;
if (!context)
context = global_namespace;
/* Create the type. */
if (DECL_ALIAS_TEMPLATE_P (gen_tmpl))
{
/* The user referred to a specialization of an alias
template represented by GEN_TMPL.
[temp.alias]/2 says:
When a template-id refers to the specialization of an
alias template, it is equivalent to the associated
type obtained by substitution of its
template-arguments for the template-parameters in the
type-id of the alias template. */
t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl);
/* Note that the call above (by indirectly calling
register_specialization in tsubst_decl) registers the
TYPE_DECL representing the specialization of the alias
template. So next time someone substitutes ARGLIST for
the template parms into the alias template (GEN_TMPL),
she'll get that TYPE_DECL back. */
if (t == error_mark_node)
return t;
}
else if (TREE_CODE (template_type) == ENUMERAL_TYPE)
{
if (!is_dependent_type)
{
set_current_access_from_decl (TYPE_NAME (template_type));
t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
tsubst (ENUM_UNDERLYING_TYPE (template_type),
arglist, complain, in_decl),
tsubst_attributes (TYPE_ATTRIBUTES (template_type),
arglist, complain, in_decl),
SCOPED_ENUM_P (template_type), NULL);
if (t == error_mark_node)
return t;
}
else
{
/* We don't want to call start_enum for this type, since
the values for the enumeration constants may involve
template parameters. And, no one should be interested
in the enumeration constants for such a type. */
t = cxx_make_type (ENUMERAL_TYPE);
SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
}
SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
ENUM_FIXED_UNDERLYING_TYPE_P (t)
= ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
}
else if (CLASS_TYPE_P (template_type))
{
/* Lambda closures are regenerated in tsubst_lambda_expr, not
instantiated here. */
gcc_assert (!LAMBDA_TYPE_P (template_type));
t = make_class_type (TREE_CODE (template_type));
CLASSTYPE_DECLARED_CLASS (t)
= CLASSTYPE_DECLARED_CLASS (template_type);
SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
/* A local class. Make sure the decl gets registered properly. */
if (context == current_function_decl)
if (pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current)
== error_mark_node)
return error_mark_node;
if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
/* This instantiation is another name for the primary
template type. Set the TYPE_CANONICAL field
appropriately. */
TYPE_CANONICAL (t) = template_type;
else if (any_template_arguments_need_structural_equality_p (arglist))
/* Some of the template arguments require structural
equality testing, so this template class requires
structural equality testing. */
SET_TYPE_STRUCTURAL_EQUALITY (t);
}
else
gcc_unreachable ();
/* If we called start_enum or pushtag above, this information
will already be set up. */
if (!TYPE_NAME (t))
{
TYPE_CONTEXT (t) = FROB_CONTEXT (context);
type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
DECL_SOURCE_LOCATION (type_decl)
= DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
}
else
type_decl = TYPE_NAME (t);
if (CLASS_TYPE_P (template_type))
{
TREE_PRIVATE (type_decl)
= TREE_PRIVATE (TYPE_MAIN_DECL (template_type));
TREE_PROTECTED (type_decl)
= TREE_PROTECTED (TYPE_MAIN_DECL (template_type));
if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
{
DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
}
}
if (OVERLOAD_TYPE_P (t)
&& !DECL_ALIAS_TEMPLATE_P (gen_tmpl))
{
static const char *tags[] = {"abi_tag", "may_alias"};
for (unsigned ix = 0; ix != 2; ix++)
{
tree attributes
= lookup_attribute (tags[ix], TYPE_ATTRIBUTES (template_type));
if (attributes)
TYPE_ATTRIBUTES (t)
= tree_cons (TREE_PURPOSE (attributes),
TREE_VALUE (attributes),
TYPE_ATTRIBUTES (t));
}
}
/* Let's consider the explicit specialization of a member
of a class template specialization that is implicitly instantiated,
e.g.:
template<class T>
struct S
{
template<class U> struct M {}; //#0
};
template<>
template<>
struct S<int>::M<char> //#1
{
int i;
};
[temp.expl.spec]/4 says this is valid.
In this case, when we write:
S<int>::M<char> m;
M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
the one of #0.
When we encounter #1, we want to store the partial instantiation
of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
For all cases other than this "explicit specialization of member of a
class template", we just want to store the most general template into
the CLASSTYPE_TI_TEMPLATE of M.
This case of "explicit specialization of member of a class template"
only happens when:
1/ the enclosing class is an instantiation of, and therefore not
the same as, the context of the most general template, and
2/ we aren't looking at the partial instantiation itself, i.e.
the innermost arguments are not the same as the innermost parms of
the most general template.
So it's only when 1/ and 2/ happens that we want to use the partial
instantiation of the member template in lieu of its most general
template. */
if (PRIMARY_TEMPLATE_P (gen_tmpl)
&& TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
/* the enclosing class must be an instantiation... */
&& CLASS_TYPE_P (context)
&& !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
{
TREE_VEC_LENGTH (arglist)--;
++processing_template_decl;
tree tinfo = TYPE_TEMPLATE_INFO_MAYBE_ALIAS (TREE_TYPE (gen_tmpl));
tree partial_inst_args =
tsubst (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo)),
arglist, complain, NULL_TREE);
--processing_template_decl;
TREE_VEC_LENGTH (arglist)++;
if (partial_inst_args == error_mark_node)
return error_mark_node;
use_partial_inst_tmpl =
/*...and we must not be looking at the partial instantiation
itself. */
!comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
partial_inst_args);
}
if (!use_partial_inst_tmpl)
/* This case is easy; there are no member templates involved. */
found = gen_tmpl;
else
{
/* This is a full instantiation of a member template. Find
the partial instantiation of which this is an instance. */
/* Temporarily reduce by one the number of levels in the ARGLIST
so as to avoid comparing the last set of arguments. */
TREE_VEC_LENGTH (arglist)--;
found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
TREE_VEC_LENGTH (arglist)++;
/* FOUND is either a proper class type, or an alias
template specialization. In the later case, it's a
TYPE_DECL, resulting from the substituting of arguments
for parameters in the TYPE_DECL of the alias template
done earlier. So be careful while getting the template
of FOUND. */
found = (TREE_CODE (found) == TEMPLATE_DECL
? found
: (TREE_CODE (found) == TYPE_DECL
? DECL_TI_TEMPLATE (found)
: CLASSTYPE_TI_TEMPLATE (found)));
if (DECL_CLASS_TEMPLATE_P (found)
&& CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (found)))
{
/* If this partial instantiation is specialized, we want to
use it for hash table lookup. */
elt.tmpl = found;
elt.args = arglist = INNERMOST_TEMPLATE_ARGS (arglist);
hash = spec_hasher::hash (&elt);
}
}
// Build template info for the new specialization.
SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
elt.spec = t;
slot = type_specializations->find_slot_with_hash (&elt, hash, INSERT);
gcc_checking_assert (*slot == NULL);
entry = ggc_alloc<spec_entry> ();
*entry = elt;
*slot = entry;
/* Note this use of the partial instantiation so we can check it
later in maybe_process_partial_specialization. */
DECL_TEMPLATE_INSTANTIATIONS (found)
= tree_cons (arglist, t,
DECL_TEMPLATE_INSTANTIATIONS (found));
if (TREE_CODE (template_type) == ENUMERAL_TYPE && !is_dependent_type
&& !DECL_ALIAS_TEMPLATE_P (gen_tmpl))
/* Now that the type has been registered on the instantiations
list, we set up the enumerators. Because the enumeration
constants may involve the enumeration type itself, we make
sure to register the type first, and then create the
constants. That way, doing tsubst_expr for the enumeration
constants won't result in recursive calls here; we'll find
the instantiation and exit above. */
tsubst_enum (template_type, t, arglist);
if (CLASS_TYPE_P (template_type) && is_dependent_type)
/* If the type makes use of template parameters, the
code that generates debugging information will crash. */
DECL_IGNORED_P (TYPE_MAIN_DECL (t)) = 1;
/* Possibly limit visibility based on template args. */
TREE_PUBLIC (type_decl) = 1;
determine_visibility (type_decl);
inherit_targ_abi_tags (t);
return t;
}
}
/* Wrapper for lookup_template_class_1. */
tree
lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
int entering_scope, tsubst_flags_t complain)
{
tree ret;
timevar_push (TV_TEMPLATE_INST);
ret = lookup_template_class_1 (d1, arglist, in_decl, context,
entering_scope, complain);
timevar_pop (TV_TEMPLATE_INST);
return ret;
}
/* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
tree
lookup_template_variable (tree templ, tree arglist)
{
/* The type of the expression is NULL_TREE since the template-id could refer
to an explicit or partial specialization. */
tree type = NULL_TREE;
if (flag_concepts && variable_concept_p (templ))
/* Except that concepts are always bool. */
type = boolean_type_node;
return build2 (TEMPLATE_ID_EXPR, type, templ, arglist);
}
/* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
tree
finish_template_variable (tree var, tsubst_flags_t complain)
{
tree templ = TREE_OPERAND (var, 0);
tree arglist = TREE_OPERAND (var, 1);
/* We never want to return a VAR_DECL for a variable concept, since they
aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
bool concept_p = flag_concepts && variable_concept_p (templ);
if (concept_p && processing_template_decl)
return var;
tree tmpl_args = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (templ));
arglist = add_outermost_template_args (tmpl_args, arglist);
templ = most_general_template (templ);
tree parms = DECL_TEMPLATE_PARMS (templ);
arglist = coerce_innermost_template_parms (parms, arglist, templ, complain,
/*req_all*/true,
/*use_default*/true);
if (flag_concepts && !constraints_satisfied_p (templ, arglist))
{
if (complain & tf_error)
{
auto_diagnostic_group d;
error ("use of invalid variable template %qE", var);
diagnose_constraints (location_of (var), templ, arglist);
}
return error_mark_node;
}
/* If a template-id refers to a specialization of a variable
concept, then the expression is true if and only if the
concept's constraints are satisfied by the given template
arguments.
NOTE: This is an extension of Concepts Lite TS that
allows constraints to be used in expressions. */
if (concept_p)
{
tree decl = DECL_TEMPLATE_RESULT (templ);
return evaluate_variable_concept (decl, arglist);
}
return instantiate_template (templ, arglist, complain);
}
/* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
TARGS template args, and instantiate it if it's not dependent. */
tree
lookup_and_finish_template_variable (tree templ, tree targs,
tsubst_flags_t complain)
{
templ = lookup_template_variable (templ, targs);
if (!any_dependent_template_arguments_p (targs))
{
templ = finish_template_variable (templ, complain);
mark_used (templ);
}
return convert_from_reference (templ);
}
struct pair_fn_data
{
tree_fn_t fn;
tree_fn_t any_fn;
void *data;
/* True when we should also visit template parameters that occur in
non-deduced contexts. */
bool include_nondeduced_p;
hash_set<tree> *visited;
};
/* Called from for_each_template_parm via walk_tree. */
static tree
for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
{
tree t = *tp;
struct pair_fn_data *pfd = (struct pair_fn_data *) d;
tree_fn_t fn = pfd->fn;
void *data = pfd->data;
tree result = NULL_TREE;
#define WALK_SUBTREE(NODE) \
do \
{ \
result = for_each_template_parm (NODE, fn, data, pfd->visited, \
pfd->include_nondeduced_p, \
pfd->any_fn); \
if (result) goto out; \
} \
while (0)
if (pfd->any_fn && (*pfd->any_fn)(t, data))
return t;
if (TYPE_P (t)
&& (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE))
WALK_SUBTREE (TYPE_CONTEXT (t));
switch (TREE_CODE (t))
{
case RECORD_TYPE:
if (TYPE_PTRMEMFUNC_P (t))
break;
/* Fall through. */
case UNION_TYPE:
case ENUMERAL_TYPE:
if (!TYPE_TEMPLATE_INFO (t))
*walk_subtrees = 0;
else
WALK_SUBTREE (TYPE_TI_ARGS (t));
break;
case INTEGER_TYPE:
WALK_SUBTREE (TYPE_MIN_VALUE (t));
WALK_SUBTREE (TYPE_MAX_VALUE (t));
break;
case METHOD_TYPE:
/* Since we're not going to walk subtrees, we have to do this
explicitly here. */
WALK_SUBTREE (TYPE_METHOD_BASETYPE (t));
/* Fall through. */
case FUNCTION_TYPE:
/* Check the return type. */
WALK_SUBTREE (TREE_TYPE (t));
/* Check the parameter types. Since default arguments are not
instantiated until they are needed, the TYPE_ARG_TYPES may
contain expressions that involve template parameters. But,
no-one should be looking at them yet. And, once they're
instantiated, they don't contain template parameters, so
there's no point in looking at them then, either. */
{
tree parm;
for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
WALK_SUBTREE (TREE_VALUE (parm));
/* Since we've already handled the TYPE_ARG_TYPES, we don't
want walk_tree walking into them itself. */
*walk_subtrees = 0;
}
if (flag_noexcept_type)
{
tree spec = TYPE_RAISES_EXCEPTIONS (t);
if (spec)
WALK_SUBTREE (TREE_PURPOSE (spec));
}
break;
case TYPEOF_TYPE:
case DECLTYPE_TYPE:
case UNDERLYING_TYPE:
if (pfd->include_nondeduced_p
&& for_each_template_parm (TYPE_VALUES_RAW (t), fn, data,
pfd->visited,
pfd->include_nondeduced_p,
pfd->any_fn))
return error_mark_node;
*walk_subtrees = false;
break;
case FUNCTION_DECL:
case VAR_DECL:
if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
WALK_SUBTREE (DECL_TI_ARGS (t));
/* Fall through. */
case PARM_DECL:
case CONST_DECL:
if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t))
WALK_SUBTREE (DECL_INITIAL (t));
if (DECL_CONTEXT (t)
&& pfd->include_nondeduced_p)
WALK_SUBTREE (DECL_CONTEXT (t));
break;
case BOUND_TEMPLATE_TEMPLATE_PARM:
/* Record template parameters such as `T' inside `TT<T>'. */
WALK_SUBTREE (TYPE_TI_ARGS (t));
/* Fall through. */
case TEMPLATE_TEMPLATE_PARM:
case TEMPLATE_TYPE_PARM:
case TEMPLATE_PARM_INDEX:
if (fn && (*fn)(t, data))
return t;
else if (!fn)
return t;
break;
case TEMPLATE_DECL:
/* A template template parameter is encountered. */
if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
WALK_SUBTREE (TREE_TYPE (t));
/* Already substituted template template parameter */
*walk_subtrees = 0;
break;
case TYPENAME_TYPE:
/* A template-id in a TYPENAME_TYPE might be a deduced context after
partial instantiation. */
WALK_SUBTREE (TYPENAME_TYPE_FULLNAME (t));
break;
case CONSTRUCTOR:
if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
&& pfd->include_nondeduced_p)
WALK_SUBTREE (TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (t)));
break;
case INDIRECT_REF:
case COMPONENT_REF:
/* If there's no type, then this thing must be some expression
involving template parameters. */
if (!fn && !TREE_TYPE (t))
return error_mark_node;
break;
case MODOP_EXPR:
case CAST_EXPR:
case IMPLICIT_CONV_EXPR:
case REINTERPRET_CAST_EXPR:
case CONST_CAST_EXPR:
case STATIC_CAST_EXPR:
case DYNAMIC_CAST_EXPR:
case ARROW_EXPR:
case DOTSTAR_EXPR:
case TYPEID_EXPR:
case PSEUDO_DTOR_EXPR:
if (!fn)
return error_mark_node;
break;
default:
break;
}
#undef WALK_SUBTREE
/* We didn't find any template parameters we liked. */
out:
return result;
}
/* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
call FN with the parameter and the DATA.
If FN returns nonzero, the iteration is terminated, and
for_each_template_parm returns 1. Otherwise, the iteration
continues. If FN never returns a nonzero value, the value
returned by for_each_template_parm is 0. If FN is NULL, it is
considered to be the function which always returns 1.
If INCLUDE_NONDEDUCED_P, then this routine will also visit template
parameters that occur in non-deduced contexts. When false, only
visits those template parameters that can be deduced. */
static tree
for_each_template_parm (tree t, tree_fn_t fn, void* data,
hash_set<tree> *visited,
bool include_nondeduced_p,
tree_fn_t any_fn)
{
struct pair_fn_data pfd;
tree result;
/* Set up. */
pfd.fn = fn;
pfd.any_fn = any_fn;
pfd.data = data;
pfd.include_nondeduced_p = include_nondeduced_p;
/* Walk the tree. (Conceptually, we would like to walk without
duplicates, but for_each_template_parm_r recursively calls
for_each_template_parm, so we would need to reorganize a fair
bit to use walk_tree_without_duplicates, so we keep our own
visited list.) */
if (visited)
pfd.visited = visited;
else
pfd.visited = new hash_set<tree>;
result = cp_walk_tree (&t,
for_each_template_parm_r,
&pfd,
pfd.visited);
/* Clean up. */
if (!visited)
{
delete pfd.visited;
pfd.visited = 0;
}
return result;
}
/* Returns true if T depends on any template parameter. */
int
uses_template_parms (tree t)
{
if (t == NULL_TREE)
return false;
bool dependent_p;
int saved_processing_template_decl;
saved_processing_template_decl = processing_template_decl;
if (!saved_processing_template_decl)
processing_template_decl = 1;
if (TYPE_P (t))
dependent_p = dependent_type_p (t);
else if (TREE_CODE (t) == TREE_VEC)
dependent_p = any_dependent_template_arguments_p (t);
else if (TREE_CODE (t) == TREE_LIST)
dependent_p = (uses_template_parms (TREE_VALUE (t))
|| uses_template_parms (TREE_CHAIN (t)));
else if (TREE_CODE (t) == TYPE_DECL)
dependent_p = dependent_type_p (TREE_TYPE (t));
else if (t == error_mark_node)
dependent_p = false;
else
dependent_p = (type_dependent_expression_p (t)
|| value_dependent_expression_p (t));
processing_template_decl = saved_processing_template_decl;
return dependent_p;
}
/* Returns true iff current_function_decl is an incompletely instantiated
template. Useful instead of processing_template_decl because the latter
is set to 0 during instantiate_non_dependent_expr. */
bool
in_template_function (void)
{
tree fn = current_function_decl;
bool ret;
++processing_template_decl;
ret = (fn && DECL_LANG_SPECIFIC (fn)
&& DECL_TEMPLATE_INFO (fn)
&& any_dependent_template_arguments_p (DECL_TI_ARGS (fn)));
--processing_template_decl;
return ret;
}
/* Returns true if T depends on any template parameter with level LEVEL. */
bool
uses_template_parms_level (tree t, int level)
{
return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
/*include_nondeduced_p=*/true);
}
/* Returns true if the signature of DECL depends on any template parameter from
its enclosing class. */
bool
uses_outer_template_parms (tree decl)
{
int depth = template_class_depth (CP_DECL_CONTEXT (decl));
if (depth == 0)
return false;
if (for_each_template_parm (TREE_TYPE (decl), template_parm_outer_level,
&depth, NULL, /*include_nondeduced_p=*/true))
return true;
if (PRIMARY_TEMPLATE_P (decl)
&& for_each_template_parm (INNERMOST_TEMPLATE_PARMS
(DECL_TEMPLATE_PARMS (decl)),
template_parm_outer_level,
&depth, NULL, /*include_nondeduced_p=*/true))
return true;
tree ci = get_constraints (decl);
if (ci)
ci = CI_ASSOCIATED_CONSTRAINTS (ci);
if (ci && for_each_template_parm (ci, template_parm_outer_level,
&depth, NULL, /*nondeduced*/true))
return true;
return false;
}
/* Returns TRUE iff INST is an instantiation we don't need to do in an
ill-formed translation unit, i.e. a variable or function that isn't
usable in a constant expression. */
static inline bool
neglectable_inst_p (tree d)
{
return (d && DECL_P (d)
&& !undeduced_auto_decl (d)
&& !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
: decl_maybe_constant_var_p (d)));
}
/* Returns TRUE iff we should refuse to instantiate DECL because it's
neglectable and instantiated from within an erroneous instantiation. */
static bool
limit_bad_template_recursion (tree decl)
{
struct tinst_level *lev = current_tinst_level;
int errs = errorcount + sorrycount;
if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
return false;
for (; lev; lev = lev->next)
if (neglectable_inst_p (lev->maybe_get_node ()))
break;
return (lev && errs > lev->errors);
}
static int tinst_depth;
extern int max_tinst_depth;
int depth_reached;
static GTY(()) struct tinst_level *last_error_tinst_level;
/* We're starting to instantiate D; record the template instantiation context
at LOC for diagnostics and to restore it later. */
static bool
push_tinst_level_loc (tree tldcl, tree targs, location_t loc)
{
struct tinst_level *new_level;
if (tinst_depth >= max_tinst_depth)
{
/* Tell error.c not to try to instantiate any templates. */
at_eof = 2;
fatal_error (input_location,
"template instantiation depth exceeds maximum of %d"
" (use %<-ftemplate-depth=%> to increase the maximum)",
max_tinst_depth);
return false;
}
/* If the current instantiation caused problems, don't let it instantiate
anything else. Do allow deduction substitution and decls usable in
constant expressions. */
if (!targs && limit_bad_template_recursion (tldcl))
return false;
/* When not -quiet, dump template instantiations other than functions, since
announce_function will take care of those. */
if (!quiet_flag && !targs
&& TREE_CODE (tldcl) != TREE_LIST
&& TREE_CODE (tldcl) != FUNCTION_DECL)
fprintf (stderr, " %s", decl_as_string (tldcl, TFF_DECL_SPECIFIERS));
new_level = tinst_level_freelist ().alloc ();
new_level->tldcl = tldcl;
new_level->targs = targs;
new_level->locus = loc;
new_level->errors = errorcount + sorrycount;
new_level->next = NULL;
new_level->refcount = 0;
set_refcount_ptr (new_level->next, current_tinst_level);
set_refcount_ptr (current_tinst_level, new_level);
++tinst_depth;
if (GATHER_STATISTICS && (tinst_depth > depth_reached))
depth_reached = tinst_depth;
return true;
}
/* We're starting substitution of TMPL<ARGS>; record the template
substitution context for diagnostics and to restore it later. */
static bool
push_tinst_level (tree tmpl, tree args)
{
return push_tinst_level_loc (tmpl, args, input_location);
}
/* We're starting to instantiate D; record INPUT_LOCATION and the
template instantiation context for diagnostics and to restore it
later. */
bool
push_tinst_level (tree d)
{
return push_tinst_level_loc (d, input_location);
}
/* Likewise, but record LOC as the program location. */
bool
push_tinst_level_loc (tree d, location_t loc)
{
gcc_assert (TREE_CODE (d) != TREE_LIST);
return push_tinst_level_loc (d, NULL, loc);
}
/* We're done instantiating this template; return to the instantiation
context. */
void
pop_tinst_level (void)
{
/* Restore the filename and line number stashed away when we started
this instantiation. */
input_location = current_tinst_level->locus;
set_refcount_ptr (current_tinst_level, current_tinst_level->next);
--tinst_depth;
}
/* We're instantiating a deferred template; restore the template
instantiation context in which the instantiation was requested, which
is one step out from LEVEL. Return the corresponding DECL or TYPE. */
static tree
reopen_tinst_level (struct tinst_level *level)
{
struct tinst_level *t;
tinst_depth = 0;
for (t = level; t; t = t->next)
++tinst_depth;
set_refcount_ptr (current_tinst_level, level);
pop_tinst_level ();
if (current_tinst_level)
current_tinst_level->errors = errorcount+sorrycount;
return level->maybe_get_node ();
}
/* Returns the TINST_LEVEL which gives the original instantiation
context. */
struct tinst_level *
outermost_tinst_level (void)
{
struct tinst_level *level = current_tinst_level;
if (level)
while (level->next)
level = level->next;
return level;
}
/* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
vector of template arguments, as for tsubst.
Returns an appropriate tsubst'd friend declaration. */
static tree
tsubst_friend_function (tree decl, tree args)
{
tree new_friend;
if (TREE_CODE (decl) == FUNCTION_DECL
&& DECL_TEMPLATE_INSTANTIATION (decl)
&& TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
/* This was a friend declared with an explicit template
argument list, e.g.:
friend void f<>(T);
to indicate that f was a template instantiation, not a new
function declaration. Now, we have to figure out what
instantiation of what template. */
{
tree template_id, arglist, fns;
tree new_args;
tree tmpl;
tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
/* Friend functions are looked up in the containing namespace scope.
We must enter that scope, to avoid finding member functions of the
current class with same name. */
push_nested_namespace (ns);
fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
tf_warning_or_error, NULL_TREE,
/*integral_constant_expression_p=*/false);
pop_nested_namespace (ns);
arglist = tsubst (DECL_TI_ARGS (decl), args,
tf_warning_or_error, NULL_TREE);
template_id = lookup_template_function (fns, arglist);
new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
tmpl = determine_specialization (template_id, new_friend,
&new_args,
/*need_member_template=*/0,
TREE_VEC_LENGTH (args),
tsk_none);
return instantiate_template (tmpl, new_args, tf_error);
}
new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
/* The NEW_FRIEND will look like an instantiation, to the
compiler, but is not an instantiation from the point of view of
the language. For example, we might have had:
template <class T> struct S {
template <class U> friend void f(T, U);
};
Then, in S<int>, template <class U> void f(int, U) is not an
instantiation of anything. */
if (new_friend == error_mark_node)
return error_mark_node;
DECL_USE_TEMPLATE (new_friend) = 0;
if (TREE_CODE (decl) == TEMPLATE_DECL)
{
DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
= DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
}
/* The mangled name for the NEW_FRIEND is incorrect. The function
is not a template instantiation and should not be mangled like
one. Therefore, we forget the mangling here; we'll recompute it
later if we need it. */
if (TREE_CODE (new_friend) != TEMPLATE_DECL)
{
SET_DECL_RTL (new_friend, NULL);
SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
}
if (DECL_NAMESPACE_SCOPE_P (new_friend))
{
tree old_decl;
tree new_friend_template_info;
tree new_friend_result_template_info;
tree ns;
int new_friend_is_defn;
/* We must save some information from NEW_FRIEND before calling
duplicate decls since that function will free NEW_FRIEND if
possible. */
new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
new_friend_is_defn =
(DECL_INITIAL (DECL_TEMPLATE_RESULT
(template_for_substitution (new_friend)))
!= NULL_TREE);
if (TREE_CODE (new_friend) == TEMPLATE_DECL)
{
/* This declaration is a `primary' template. */
DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
new_friend_result_template_info
= DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
}
else
new_friend_result_template_info = NULL_TREE;
/* Inside pushdecl_namespace_level, we will push into the
current namespace. However, the friend function should go
into the namespace of the template. */
ns = decl_namespace_context (new_friend);
push_nested_namespace (ns);
old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
pop_nested_namespace (ns);
if (old_decl == error_mark_node)
return error_mark_node;
if (old_decl != new_friend)
{
/* This new friend declaration matched an existing
declaration. For example, given:
template <class T> void f(T);
template <class U> class C {
template <class T> friend void f(T) {}
};
the friend declaration actually provides the definition
of `f', once C has been instantiated for some type. So,
old_decl will be the out-of-class template declaration,
while new_friend is the in-class definition.
But, if `f' was called before this point, the
instantiation of `f' will have DECL_TI_ARGS corresponding
to `T' but not to `U', references to which might appear
in the definition of `f'. Previously, the most general
template for an instantiation of `f' was the out-of-class
version; now it is the in-class version. Therefore, we
run through all specialization of `f', adding to their
DECL_TI_ARGS appropriately. In particular, they need a
new set of outer arguments, corresponding to the
arguments for this class instantiation.
The same situation can arise with something like this:
friend void f(int);
template <class T> class C {
friend void f(T) {}
};
when `C<int>' is instantiated. Now, `f(int)' is defined
in the class. */
if (!new_friend_is_defn)
/* On the other hand, if the in-class declaration does
*not* provide a definition, then we don't want to alter
existing definitions. We can just leave everything
alone. */
;
else
{
tree new_template = TI_TEMPLATE (new_friend_template_info);
tree new_args = TI_ARGS (new_friend_template_info);
/* Overwrite whatever template info was there before, if
any, with the new template information pertaining to
the declaration. */
DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
if (TREE_CODE (old_decl) != TEMPLATE_DECL)
{
/* We should have called reregister_specialization in
duplicate_decls. */
gcc_assert (retrieve_specialization (new_template,
new_args, 0)
== old_decl);
/* Instantiate it if the global has already been used. */
if (DECL_ODR_USED (old_decl))
instantiate_decl (old_decl, /*defer_ok=*/true,
/*expl_inst_class_mem_p=*/false);
}
else
{
tree t;
/* Indicate that the old function template is a partial
instantiation. */
DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
= new_friend_result_template_info;
gcc_assert (new_template
== most_general_template (new_template));
gcc_assert (new_template != old_decl);
/* Reassign any specializations already in the hash table
to the new more general template, and add the
additional template args. */
for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
t != NULL_TREE;
t = TREE_CHAIN (t))
{
tree spec = TREE_VALUE (t);
spec_entry elt;
elt.tmpl = old_decl;
elt.args = DECL_TI_ARGS (spec);
elt.spec = NULL_TREE;
decl_specializations->remove_elt (&elt);
DECL_TI_ARGS (spec)
= add_outermost_template_args (new_args,
DECL_TI_ARGS (spec));
register_specialization
(spec, new_template, DECL_TI_ARGS (spec), true, 0);
}
DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
}
}
/* The information from NEW_FRIEND has been merged into OLD_DECL
by duplicate_decls. */
new_friend = old_decl;
}
}
else
{
tree context = DECL_CONTEXT (new_friend);
bool dependent_p;
/* In the code
template <class T> class C {
template <class U> friend void C1<U>::f (); // case 1
friend void C2<T>::f (); // case 2
};
we only need to make sure CONTEXT is a complete type for
case 2. To distinguish between the two cases, we note that
CONTEXT of case 1 remains dependent type after tsubst while
this isn't true for case 2. */
++processing_template_decl;
dependent_p = dependent_type_p (context);
--processing_template_decl;
if (!dependent_p
&& !complete_type_or_else (context, NULL_TREE))
return error_mark_node;
if (COMPLETE_TYPE_P (context))
{
tree fn = new_friend;
/* do_friend adds the TEMPLATE_DECL for any member friend
template even if it isn't a member template, i.e.
template <class T> friend A<T>::f();
Look through it in that case. */
if (TREE_CODE (fn) == TEMPLATE_DECL
&& !PRIMARY_TEMPLATE_P (fn))
fn = DECL_TEMPLATE_RESULT (fn);
/* Check to see that the declaration is really present, and,
possibly obtain an improved declaration. */
fn = check_classfn (context, fn, NULL_TREE);
if (fn)
new_friend = fn;
}
}
return new_friend;
}
/* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
template arguments, as for tsubst.
Returns an appropriate tsubst'd friend type or error_mark_node on
failure. */
static tree
tsubst_friend_class (tree friend_tmpl, tree args)
{
tree tmpl;
if (DECL_TEMPLATE_TEMPLATE_PARM_P (friend_tmpl))
{
tmpl = tsubst (TREE_TYPE (friend_tmpl), args, tf_none, NULL_TREE);
return TREE_TYPE (tmpl);
}
tree context = CP_DECL_CONTEXT (friend_tmpl);
if (TREE_CODE (context) == NAMESPACE_DECL)
push_nested_namespace (context);
else
{
context = tsubst (context, args, tf_error, NULL_TREE);
push_nested_class (context);
}
tmpl = lookup_name_real (DECL_NAME (friend_tmpl), /*prefer_type=*/false,
/*non_class=*/false, /*block_p=*/false,
/*namespaces_only=*/false, LOOKUP_HIDDEN);
if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
{
/* The friend template has already been declared. Just
check to see that the declarations match, and install any new
default parameters. We must tsubst the default parameters,
of course. We only need the innermost template parameters
because that is all that redeclare_class_template will look
at. */
if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
> TMPL_ARGS_DEPTH (args))
{
tree parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
args, tf_warning_or_error);
location_t saved_input_location = input_location;
input_location = DECL_SOURCE_LOCATION (friend_tmpl);
tree cons = get_constraints (tmpl);
redeclare_class_template (TREE_TYPE (tmpl), parms, cons);
input_location = saved_input_location;
}
}
else
{
/* The friend template has not already been declared. In this
case, the instantiation of the template class will cause the
injection of this template into the namespace scope. */
tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
if (tmpl != error_mark_node)
{
/* The new TMPL is not an instantiation of anything, so we
forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE
for the new type because that is supposed to be the
corresponding template decl, i.e., TMPL. */
DECL_USE_TEMPLATE (tmpl) = 0;
DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
= INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
/* It is hidden. */
retrofit_lang_decl (DECL_TEMPLATE_RESULT (tmpl));
DECL_ANTICIPATED (tmpl)
= DECL_ANTICIPATED (DECL_TEMPLATE_RESULT (tmpl)) = true;
/* Inject this template into the enclosing namspace scope. */
tmpl = pushdecl_namespace_level (tmpl, true);
}
}
if (TREE_CODE (context) == NAMESPACE_DECL)
pop_nested_namespace (context);
else
pop_nested_class ();
return TREE_TYPE (tmpl);
}
/* Returns zero if TYPE cannot be completed later due to circularity.
Otherwise returns one. */
static int
can_complete_type_without_circularity (tree type)
{
if (type == NULL_TREE || type == error_mark_node)
return 0;
else if (COMPLETE_TYPE_P (type))
return 1;
else if (TREE_CODE (type) == ARRAY_TYPE)
return can_complete_type_without_circularity (TREE_TYPE (type));
else if (CLASS_TYPE_P (type)
&& TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
return 0;
else
return 1;
}
static tree tsubst_omp_clauses (tree, enum c_omp_region_type, tree,
tsubst_flags_t, tree);
/* Instantiate a single dependent attribute T (a TREE_LIST), and return either
T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
static tree
tsubst_attribute (tree t, tree *decl_p, tree args,
tsubst_flags_t complain, tree in_decl)
{
gcc_assert (ATTR_IS_DEPENDENT (t));
tree val = TREE_VALUE (t);
if (val == NULL_TREE)
/* Nothing to do. */;
else if ((flag_openmp || flag_openmp_simd)
&& is_attribute_p ("omp declare simd",
get_attribute_name (t)))
{
tree clauses = TREE_VALUE (val);
clauses = tsubst_omp_clauses (clauses, C_ORT_OMP_DECLARE_SIMD, args,
complain, in_decl);
c_omp_declare_simd_clauses_to_decls (*decl_p, clauses);
clauses = finish_omp_clauses (clauses, C_ORT_OMP_DECLARE_SIMD);
tree parms = DECL_ARGUMENTS (*decl_p);
clauses
= c_omp_declare_simd_clauses_to_numbers (parms, clauses);
if (clauses)
val = build_tree_list (NULL_TREE, clauses);
else
val = NULL_TREE;
}
/* If the first attribute argument is an identifier, don't
pass it through tsubst. Attributes like mode, format,
cleanup and several target specific attributes expect it
unmodified. */
else if (attribute_takes_identifier_p (get_attribute_name (t)))
{
tree chain
= tsubst_expr (TREE_CHAIN (val), args, complain, in_decl,
/*integral_constant_expression_p=*/false);
if (chain != TREE_CHAIN (val))
val = tree_cons (NULL_TREE, TREE_VALUE (val), chain);
}
else if (PACK_EXPANSION_P (val))
{
/* An attribute pack expansion. */
tree purp = TREE_PURPOSE (t);
tree pack = tsubst_pack_expansion (val, args, complain, in_decl);
if (pack == error_mark_node)
return error_mark_node;
int len = TREE_VEC_LENGTH (pack);
tree list = NULL_TREE;
tree *q = &list;
for (int i = 0; i < len; ++i)
{
tree elt = TREE_VEC_ELT (pack, i);
*q = build_tree_list (purp, elt);
q = &TREE_CHAIN (*q);
}
return list;
}
else
val = tsubst_expr (val, args, complain, in_decl,
/*integral_constant_expression_p=*/false);
if (val != TREE_VALUE (t))
return build_tree_list (TREE_PURPOSE (t), val);
return t;
}
/* Instantiate any dependent attributes in ATTRIBUTES, returning either it
unchanged or a new TREE_LIST chain. */
static tree
tsubst_attributes (tree attributes, tree args,
tsubst_flags_t complain, tree in_decl)
{
tree last_dep = NULL_TREE;
for (tree t = attributes; t; t = TREE_CHAIN (t))
if (ATTR_IS_DEPENDENT (t))
{
last_dep = t;
attributes = copy_list (attributes);
break;
}
if (last_dep)
for (tree *p = &attributes; *p; )
{
tree t = *p;
if (ATTR_IS_DEPENDENT (t))
{
tree subst = tsubst_attribute (t, NULL, args, complain, in_decl);
if (subst != t)
{
*p = subst;
while (*p)
p = &TREE_CHAIN (*p);
*p = TREE_CHAIN (t);
continue;
}
}
p = &TREE_CHAIN (*p);
}
return attributes;
}
/* Apply any attributes which had to be deferred until instantiation
time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
ARGS, COMPLAIN, IN_DECL are as tsubst. */
static void
apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
tree args, tsubst_flags_t complain, tree in_decl)
{
tree last_dep = NULL_TREE;
tree t;
tree *p;
if (attributes == NULL_TREE)
return;
if (DECL_P (*decl_p))
{
if (TREE_TYPE (*decl_p) == error_mark_node)
return;
p = &DECL_ATTRIBUTES (*decl_p);
/* DECL_ATTRIBUTES comes from copy_node in tsubst_decl, and is identical
to our attributes parameter. */
gcc_assert (*p == attributes);
}
else
{
p = &TYPE_ATTRIBUTES (*decl_p);
/* TYPE_ATTRIBUTES was set up (with abi_tag and may_alias) in
lookup_template_class_1, and should be preserved. */
gcc_assert (*p != attributes);
while (*p)
p = &TREE_CHAIN (*p);
}
for (t = attributes; t; t = TREE_CHAIN (t))
if (ATTR_IS_DEPENDENT (t))
{
last_dep = t;
attributes = copy_list (attributes);
break;
}
*p = attributes;
if (last_dep)
{
tree late_attrs = NULL_TREE;
tree *q = &late_attrs;
for (; *p; )
{
t = *p;
if (ATTR_IS_DEPENDENT (t))
{
*p = TREE_CHAIN (t);
TREE_CHAIN (t) = NULL_TREE;
*q = tsubst_attribute (t, decl_p, args, complain, in_decl);
while (*q)
q = &TREE_CHAIN (*q);
}
else
p = &TREE_CHAIN (t);
}
cplus_decl_attributes (decl_p, late_attrs, attr_flags);
}
}
/* Perform (or defer) access check for typedefs that were referenced
from within the template TMPL code.
This is a subroutine of instantiate_decl and instantiate_class_template.
TMPL is the template to consider and TARGS is the list of arguments of
that template. */
static void
perform_typedefs_access_check (tree tmpl, tree targs)
{
location_t saved_location;
unsigned i;
qualified_typedef_usage_t *iter;
if (!tmpl
|| (!CLASS_TYPE_P (tmpl)
&& TREE_CODE (tmpl) != FUNCTION_DECL))
return;
saved_location = input_location;
FOR_EACH_VEC_SAFE_ELT (get_types_needing_access_check (tmpl), i, iter)
{
tree type_decl = iter->typedef_decl;
tree type_scope = iter->context;
if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
continue;
if (uses_template_parms (type_decl))
type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
if (uses_template_parms (type_scope))
type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
/* Make access check error messages point to the location
of the use of the typedef. */
input_location = iter->locus;
perform_or_defer_access_check (TYPE_BINFO (type_scope),
type_decl, type_decl,
tf_warning_or_error);
}
input_location = saved_location;
}
static tree
instantiate_class_template_1 (tree type)
{
tree templ, args, pattern, t, member;
tree typedecl;
tree pbinfo;
tree base_list;
unsigned int saved_maximum_field_alignment;
tree fn_context;
if (type == error_mark_node)
return error_mark_node;
if (COMPLETE_OR_OPEN_TYPE_P (type)
|| uses_template_parms (type))
return type;
/* Figure out which template is being instantiated. */
templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
/* Mark the type as in the process of being defined. */
TYPE_BEING_DEFINED (type) = 1;
/* We may be in the middle of deferred access check. Disable
it now. */
deferring_access_check_sentinel acs (dk_no_deferred);
/* Determine what specialization of the original template to
instantiate. */
t = most_specialized_partial_spec (type, tf_warning_or_error);
if (t == error_mark_node)
return error_mark_node;
else if (t)
{
/* This TYPE is actually an instantiation of a partial
specialization. We replace the innermost set of ARGS with
the arguments appropriate for substitution. For example,
given:
template <class T> struct S {};
template <class T> struct S<T*> {};
and supposing that we are instantiating S<int*>, ARGS will
presently be {int*} -- but we need {int}. */
pattern = TREE_TYPE (t);
args = TREE_PURPOSE (t);
}
else
{
pattern = TREE_TYPE (templ);
args = CLASSTYPE_TI_ARGS (type);
}
/* If the template we're instantiating is incomplete, then clearly
there's nothing we can do. */
if (!COMPLETE_TYPE_P (pattern))
{
/* We can try again later. */
TYPE_BEING_DEFINED (type) = 0;
return type;
}
/* If we've recursively instantiated too many templates, stop. */
if (! push_tinst_level (type))
return type;
int saved_unevaluated_operand = cp_unevaluated_operand;
int saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
fn_context = decl_function_context (TYPE_MAIN_DECL (type));
/* Also avoid push_to_top_level for a lambda in an NSDMI. */
if (!fn_context && LAMBDA_TYPE_P (type) && TYPE_CLASS_SCOPE_P (type))
fn_context = error_mark_node;
if (!fn_context)
push_to_top_level ();
else
{
cp_unevaluated_operand = 0;
c_inhibit_evaluation_warnings = 0;
}
/* Use #pragma pack from the template context. */
saved_maximum_field_alignment = maximum_field_alignment;
maximum_field_alignment = TYPE_PRECISION (pattern);
SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
/* Set the input location to the most specialized template definition.
This is needed if tsubsting causes an error. */
typedecl = TYPE_MAIN_DECL (pattern);
input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
DECL_SOURCE_LOCATION (typedecl);
TYPE_PACKED (type) = TYPE_PACKED (pattern);
SET_TYPE_ALIGN (type, TYPE_ALIGN (pattern));
TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
CLASSTYPE_NON_AGGREGATE (type) = CLASSTYPE_NON_AGGREGATE (pattern);
if (ANON_AGGR_TYPE_P (pattern))
SET_ANON_AGGR_TYPE_P (type);
if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
{
CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
/* Adjust visibility for template arguments. */
determine_visibility (TYPE_MAIN_DECL (type));
}
if (CLASS_TYPE_P (type))
CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
pbinfo = TYPE_BINFO (pattern);
/* We should never instantiate a nested class before its enclosing
class; we need to look up the nested class by name before we can
instantiate it, and that lookup should instantiate the enclosing
class. */
gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
|| COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
base_list = NULL_TREE;
if (BINFO_N_BASE_BINFOS (pbinfo))
{
tree pbase_binfo;
tree pushed_scope;
int i;
/* We must enter the scope containing the type, as that is where
the accessibility of types named in dependent bases are
looked up from. */
pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
/* Substitute into each of the bases to determine the actual
basetypes. */
for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
{
tree base;
tree access = BINFO_BASE_ACCESS (pbinfo, i);
tree expanded_bases = NULL_TREE;
int idx, len = 1;
if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
{
expanded_bases =
tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
args, tf_error, NULL_TREE);
if (expanded_bases == error_mark_node)
continue;
len = TREE_VEC_LENGTH (expanded_bases);
}
for (idx = 0; idx < len; idx++)
{
if (expanded_bases)
/* Extract the already-expanded base class. */
base = TREE_VEC_ELT (expanded_bases, idx);
else
/* Substitute to figure out the base class. */
base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
NULL_TREE);
if (base == error_mark_node)
continue;
base_list = tree_cons (access, base, base_list);
if (BINFO_VIRTUAL_P (pbase_binfo))
TREE_TYPE (base_list) = integer_type_node;
}
}
/* The list is now in reverse order; correct that. */
base_list = nreverse (base_list);
if (pushed_scope)
pop_scope (pushed_scope);
}
/* Now call xref_basetypes to set up all the base-class
information. */
xref_basetypes (type, base_list);
apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
(int) ATTR_FLAG_TYPE_IN_PLACE,
args, tf_error, NULL_TREE);
fixup_attribute_variants (type);
/* Now that our base classes are set up, enter the scope of the
class, so that name lookups into base classes, etc. will work
correctly. This is precisely analogous to what we do in
begin_class_definition when defining an ordinary non-template
class, except we also need to push the enclosing classes. */
push_nested_class (type);
/* Now members are processed in the order of declaration. */
for (member = CLASSTYPE_DECL_LIST (pattern);
member; member = TREE_CHAIN (member))
{
tree t = TREE_VALUE (member);
if (TREE_PURPOSE (member))
{
if (TYPE_P (t))
{
if (LAMBDA_TYPE_P (t))
/* A closure type for a lambda in an NSDMI or default argument.
Ignore it; it will be regenerated when needed. */
continue;
/* Build new CLASSTYPE_NESTED_UTDS. */
tree newtag;
bool class_template_p;
class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
&& TYPE_LANG_SPECIFIC (t)
&& CLASSTYPE_IS_TEMPLATE (t));
/* If the member is a class template, then -- even after
substitution -- there may be dependent types in the
template argument list for the class. We increment
PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
that function will assume that no types are dependent
when outside of a template. */
if (class_template_p)
++processing_template_decl;
newtag = tsubst (t, args, tf_error, NULL_TREE);
if (class_template_p)
--processing_template_decl;
if (newtag == error_mark_node)
continue;
if (TREE_CODE (newtag) != ENUMERAL_TYPE)
{
tree name = TYPE_IDENTIFIER (t);
if (class_template_p)
/* Unfortunately, lookup_template_class sets
CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
instantiation (i.e., for the type of a member
template class nested within a template class.)
This behavior is required for
maybe_process_partial_specialization to work
correctly, but is not accurate in this case;
the TAG is not an instantiation of anything.
(The corresponding TEMPLATE_DECL is an
instantiation, but the TYPE is not.) */
CLASSTYPE_USE_TEMPLATE (newtag) = 0;
/* Now, we call pushtag to put this NEWTAG into the scope of
TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
pushtag calling push_template_decl. We don't have to do
this for enums because it will already have been done in
tsubst_enum. */
if (name)
SET_IDENTIFIER_TYPE_VALUE (name, newtag);
pushtag (name, newtag, /*tag_scope=*/ts_current);
}
}
else if (DECL_DECLARES_FUNCTION_P (t))
{
tree r;
if (TREE_CODE (t) == TEMPLATE_DECL)
++processing_template_decl;
r = tsubst (t, args, tf_error, NULL_TREE);
if (TREE_CODE (t) == TEMPLATE_DECL)
--processing_template_decl;
set_current_access_from_decl (r);
finish_member_declaration (r);
/* Instantiate members marked with attribute used. */
if (r != error_mark_node && DECL_PRESERVE_P (r))
mark_used (r);
if (TREE_CODE (r) == FUNCTION_DECL
&& DECL_OMP_DECLARE_REDUCTION_P (r))
cp_check_omp_declare_reduction (r);
}
else if ((DECL_CLASS_TEMPLATE_P (t) || DECL_IMPLICIT_TYPEDEF_P (t))
&& LAMBDA_TYPE_P (TREE_TYPE (t)))
/* A closure type for a lambda in an NSDMI or default argument.
Ignore it; it will be regenerated when needed. */;
else
{
/* Build new TYPE_FIELDS. */
if (TREE_CODE (t) == STATIC_ASSERT)
{
tree condition;
++c_inhibit_evaluation_warnings;
condition =
tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
tf_warning_or_error, NULL_TREE,
/*integral_constant_expression_p=*/true);
--c_inhibit_evaluation_warnings;
finish_static_assert (condition,
STATIC_ASSERT_MESSAGE (t),
STATIC_ASSERT_SOURCE_LOCATION (t),
/*member_p=*/true);
}
else if (TREE_CODE (t) != CONST_DECL)
{
tree r;
tree vec = NULL_TREE;
int len = 1;
/* The file and line for this declaration, to
assist in error message reporting. Since we
called push_tinst_level above, we don't need to
restore these. */
input_location = DECL_SOURCE_LOCATION (t);
if (TREE_CODE (t) == TEMPLATE_DECL)
++processing_template_decl;
r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
if (TREE_CODE (t) == TEMPLATE_DECL)
--processing_template_decl;
if (TREE_CODE (r) == TREE_VEC)
{
/* A capture pack became multiple fields. */
vec = r;
len = TREE_VEC_LENGTH (vec);
}
for (int i = 0; i < len; ++i)
{
if (vec)
r = TREE_VEC_ELT (vec, i);
if (VAR_P (r))
{
/* In [temp.inst]:
[t]he initialization (and any associated
side-effects) of a static data member does
not occur unless the static data member is
itself used in a way that requires the
definition of the static data member to
exist.
Therefore, we do not substitute into the
initialized for the static data member here. */
finish_static_data_member_decl
(r,
/*init=*/NULL_TREE,
/*init_const_expr_p=*/false,
/*asmspec_tree=*/NULL_TREE,
/*flags=*/0);
/* Instantiate members marked with attribute used. */
if (r != error_mark_node && DECL_PRESERVE_P (r))
mark_used (r);
}
else if (TREE_CODE (r) == FIELD_DECL)
{
/* Determine whether R has a valid type and can be
completed later. If R is invalid, then its type
is replaced by error_mark_node. */
tree rtype = TREE_TYPE (r);
if (can_complete_type_without_circularity (rtype))
complete_type (rtype);
if (!complete_or_array_type_p (rtype))
{
/* If R's type couldn't be completed and
it isn't a flexible array member (whose
type is incomplete by definition) give
an error. */
cxx_incomplete_type_error (r, rtype);
TREE_TYPE (r) = error_mark_node;
}
else if (TREE_CODE (rtype) == ARRAY_TYPE
&& TYPE_DOMAIN (rtype) == NULL_TREE
&& (TREE_CODE (type) == UNION_TYPE
|| TREE_CODE (type) == QUAL_UNION_TYPE))
{
error ("flexible array member %qD in union", r);
TREE_TYPE (r) = error_mark_node;
}
}
/* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
such a thing will already have been added to the field
list by tsubst_enum in finish_member_declaration in the
CLASSTYPE_NESTED_UTDS case above. */
if (!(TREE_CODE (r) == TYPE_DECL
&& TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
&& DECL_ARTIFICIAL (r)))
{
set_current_access_from_decl (r);
finish_member_declaration (r);
}
}
}
}
}
else
{
if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t)
|| DECL_TEMPLATE_TEMPLATE_PARM_P (t))
{
/* Build new CLASSTYPE_FRIEND_CLASSES. */
tree friend_type = t;
bool adjust_processing_template_decl = false;
if (TREE_CODE (friend_type) == TEMPLATE_DECL)
{
/* template <class T> friend class C; */
friend_type = tsubst_friend_class (friend_type, args);
adjust_processing_template_decl = true;
}
else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
{
/* template <class T> friend class C::D; */
friend_type = tsubst (friend_type, args,
tf_warning_or_error, NULL_TREE);
if (TREE_CODE (friend_type) == TEMPLATE_DECL)
friend_type = TREE_TYPE (friend_type);
adjust_processing_template_decl = true;
}
else if (TREE_CODE (friend_type) == TYPENAME_TYPE
|| TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
{
/* This could be either
friend class T::C;
when dependent_type_p is false or
template <class U> friend class T::C;
otherwise. */
/* Bump processing_template_decl in case this is something like
template <class T> friend struct A<T>::B. */
++processing_template_decl;
friend_type = tsubst (friend_type, args,
tf_warning_or_error, NULL_TREE);
if (dependent_type_p (friend_type))
adjust_processing_template_decl = true;
--processing_template_decl;
}
else if (TREE_CODE (friend_type) != BOUND_TEMPLATE_TEMPLATE_PARM
&& !CLASSTYPE_USE_TEMPLATE (friend_type)
&& TYPE_HIDDEN_P (friend_type))
{
/* friend class C;
where C hasn't been declared yet. Let's lookup name
from namespace scope directly, bypassing any name that
come from dependent base class. */
tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
/* The call to xref_tag_from_type does injection for friend
classes. */
push_nested_namespace (ns);
friend_type =
xref_tag_from_type (friend_type, NULL_TREE,
/*tag_scope=*/ts_current);
pop_nested_namespace (ns);
}
else if (uses_template_parms (friend_type))
/* friend class C<T>; */
friend_type = tsubst (friend_type, args,
tf_warning_or_error, NULL_TREE);
/* Otherwise it's
friend class C;
where C is already declared or
friend class C<int>;
We don't have to do anything in these cases. */
if (adjust_processing_template_decl)
/* Trick make_friend_class into realizing that the friend
we're adding is a template, not an ordinary class. It's
important that we use make_friend_class since it will
perform some error-checking and output cross-reference
information. */
++processing_template_decl;
if (friend_type != error_mark_node)
make_friend_class (type, friend_type, /*complain=*/false);
if (adjust_processing_template_decl)
--processing_template_decl;
}
else
{
/* Build new DECL_FRIENDLIST. */
tree r;
/* The file and line for this declaration, to
assist in error message reporting. Since we
called push_tinst_level above, we don't need to
restore these. */
input_location = DECL_SOURCE_LOCATION (t);
if (TREE_CODE (t) == TEMPLATE_DECL)
{
++processing_template_decl;
push_deferring_access_checks (dk_no_check);
}
r = tsubst_friend_function (t, args);
add_friend (type, r, /*complain=*/false);
if (TREE_CODE (t) == TEMPLATE_DECL)
{
pop_deferring_access_checks ();
--processing_template_decl;
}
}
}
}
if (fn_context)
{
/* Restore these before substituting into the lambda capture
initializers. */
cp_unevaluated_operand = saved_unevaluated_operand;
c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
}
/* Set the file and line number information to whatever is given for
the class itself. This puts error messages involving generated
implicit functions at a predictable point, and the same point
that would be used for non-template classes. */
input_location = DECL_SOURCE_LOCATION (typedecl);
unreverse_member_declarations (type);
finish_struct_1 (type);
TYPE_BEING_DEFINED (type) = 0;
/* We don't instantiate default arguments for member functions. 14.7.1:
The implicit instantiation of a class template specialization causes
the implicit instantiation of the declarations, but not of the
definitions or default arguments, of the class member functions,
member classes, static data members and member templates.... */
/* Some typedefs referenced from within the template code need to be access
checked at template instantiation time, i.e now. These types were
added to the template at parsing time. Let's get those and perform
the access checks then. */
perform_typedefs_access_check (pattern, args);
perform_deferred_access_checks (tf_warning_or_error);
pop_nested_class ();
maximum_field_alignment = saved_maximum_field_alignment;
if (!fn_context)
pop_from_top_level ();
pop_tinst_level ();
/* The vtable for a template class can be emitted in any translation
unit in which the class is instantiated. When there is no key
method, however, finish_struct_1 will already have added TYPE to
the keyed_classes. */
if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
vec_safe_push (keyed_classes, type);
return type;
}
/* Wrapper for instantiate_class_template_1. */
tree
instantiate_class_template (tree type)
{
tree ret;
timevar_push (TV_TEMPLATE_INST);
ret = instantiate_class_template_1 (type);
timevar_pop (TV_TEMPLATE_INST);
return ret;
}
static tree
tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
{
tree r;
if (!t)
r = t;
else if (TYPE_P (t))
r = tsubst (t, args, complain, in_decl);
else
{
if (!(complain & tf_warning))
++c_inhibit_evaluation_warnings;
r = tsubst_expr (t, args, complain, in_decl,
/*integral_constant_expression_p=*/true);
if (!(complain & tf_warning))
--c_inhibit_evaluation_warnings;
}
return r;
}
/* Given a function parameter pack TMPL_PARM and some function parameters
instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
and set *SPEC_P to point at the next point in the list. */
tree
extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
{
/* Collect all of the extra "packed" parameters into an
argument pack. */
tree parmvec;
tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
tree spec_parm = *spec_p;
int i, len;
for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
if (tmpl_parm
&& !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
break;
/* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
parmvec = make_tree_vec (len);
spec_parm = *spec_p;
for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
{
tree elt = spec_parm;
if (DECL_PACK_P (elt))
elt = make_pack_expansion (elt);
TREE_VEC_ELT (parmvec, i) = elt;
}
/* Build the argument packs. */
SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
*spec_p = spec_parm;
return argpack;
}
/* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
NONTYPE_ARGUMENT_PACK. */
static tree
make_fnparm_pack (tree spec_parm)
{
return extract_fnparm_pack (NULL_TREE, &spec_parm);
}
/* Return 1 if the Ith element of the argument pack ARG_PACK is a
pack expansion with no extra args, 2 if it has extra args, or 0
if it is not a pack expansion. */
static int
argument_pack_element_is_expansion_p (tree arg_pack, int i)
{
if (TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
/* We're being called before this happens in tsubst_pack_expansion. */
arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
tree vec = ARGUMENT_PACK_ARGS (arg_pack);
if (i >= TREE_VEC_LENGTH (vec))
return 0;
tree elt = TREE_VEC_ELT (vec, i);
if (DECL_P (elt))
/* A decl pack is itself an expansion. */
elt = TREE_TYPE (elt);
if (!PACK_EXPANSION_P (elt))
return 0;
if (PACK_EXPANSION_EXTRA_ARGS (elt))
return 2;
return 1;
}
/* Creates and return an ARGUMENT_PACK_SELECT tree node. */
static tree
make_argument_pack_select (tree arg_pack, unsigned index)
{
tree aps = make_node (ARGUMENT_PACK_SELECT);
ARGUMENT_PACK_SELECT_FROM_PACK (aps) = arg_pack;
ARGUMENT_PACK_SELECT_INDEX (aps) = index;
return aps;
}
/* This is a subroutine of tsubst_pack_expansion.
It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
mechanism to store the (non complete list of) arguments of the
substitution and return a non substituted pack expansion, in order
to wait for when we have enough arguments to really perform the
substitution. */
static bool
use_pack_expansion_extra_args_p (tree parm_packs,
int arg_pack_len,
bool has_empty_arg)
{
/* If one pack has an expansion and another pack has a normal
argument or if one pack has an empty argument and an another
one hasn't then tsubst_pack_expansion cannot perform the
substitution and need to fall back on the
PACK_EXPANSION_EXTRA mechanism. */
if (parm_packs == NULL_TREE)
return false;
else if (has_empty_arg)
return true;
bool has_expansion_arg = false;
for (int i = 0 ; i < arg_pack_len; ++i)
{
bool has_non_expansion_arg = false;
for (tree parm_pack = parm_packs;
parm_pack;
parm_pack = TREE_CHAIN (parm_pack))
{
tree arg = TREE_VALUE (parm_pack);
int exp = argument_pack_element_is_expansion_p (arg, i);
if (exp == 2)
/* We can't substitute a pack expansion with extra args into
our pattern. */
return true;
else if (exp)
has_expansion_arg = true;
else
has_non_expansion_arg = true;
}
if (has_expansion_arg && has_non_expansion_arg)
return true;
}
return false;
}
/* [temp.variadic]/6 says that:
The instantiation of a pack expansion [...]
produces a list E1,E2, ..., En, where N is the number of elements
in the pack expansion parameters.
This subroutine of tsubst_pack_expansion produces one of these Ei.
PATTERN is the pattern of the pack expansion. PARM_PACKS is a
TREE_LIST in which each TREE_PURPOSE is a parameter pack of
PATTERN, and each TREE_VALUE is its corresponding argument pack.
INDEX is the index 'i' of the element Ei to produce. ARGS,
COMPLAIN, and IN_DECL are the same parameters as for the
tsubst_pack_expansion function.
The function returns the resulting Ei upon successful completion,
or error_mark_node.
Note that this function possibly modifies the ARGS parameter, so
it's the responsibility of the caller to restore it. */
static tree
gen_elem_of_pack_expansion_instantiation (tree pattern,
tree parm_packs,
unsigned index,
tree args /* This parm gets
modified. */,
tsubst_flags_t complain,
tree in_decl)
{
tree t;
bool ith_elem_is_expansion = false;
/* For each parameter pack, change the substitution of the parameter
pack to the ith argument in its argument pack, then expand the
pattern. */
for (tree pack = parm_packs; pack; pack = TREE_CHAIN (pack))
{
tree parm = TREE_PURPOSE (pack);
tree arg_pack = TREE_VALUE (pack);
tree aps; /* instance of ARGUMENT_PACK_SELECT. */
ith_elem_is_expansion |=
argument_pack_element_is_expansion_p (arg_pack, index);
/* Select the Ith argument from the pack. */
if (TREE_CODE (parm) == PARM_DECL
|| VAR_P (parm)
|| TREE_CODE (parm) == FIELD_DECL)
{
if (index == 0)
{
aps = make_argument_pack_select (arg_pack, index);
if (!mark_used (parm, complain) && !(complain & tf_error))
return error_mark_node;
register_local_specialization (aps, parm);
}
else
aps = retrieve_local_specialization (parm);
}
else
{
int idx, level;
template_parm_level_and_index (parm, &level, &idx);
if (index == 0)
{
aps = make_argument_pack_select (arg_pack, index);
/* Update the corresponding argument. */
TMPL_ARG (args, level, idx) = aps;
}
else
/* Re-use the ARGUMENT_PACK_SELECT. */
aps = TMPL_ARG (args, level, idx);
}
ARGUMENT_PACK_SELECT_INDEX (aps) = index;
}
/* Substitute into the PATTERN with the (possibly altered)
arguments. */
if (pattern == in_decl)
/* Expanding a fixed parameter pack from
coerce_template_parameter_pack. */
t = tsubst_decl (pattern, args, complain);
else if (pattern == error_mark_node)
t = error_mark_node;
else if (constraint_p (pattern))
{
if (processing_template_decl)
t = tsubst_constraint (pattern, args, complain, in_decl);
else
t = (constraints_satisfied_p (pattern, args)
? boolean_true_node : boolean_false_node);
}
else if (!TYPE_P (pattern))
t = tsubst_expr (pattern, args, complain, in_decl,
/*integral_constant_expression_p=*/false);
else
t = tsubst (pattern, args, complain, in_decl);
/* If the Ith argument pack element is a pack expansion, then
the Ith element resulting from the substituting is going to
be a pack expansion as well. */
if (ith_elem_is_expansion)
t = make_pack_expansion (t, complain);
return t;
}
/* When the unexpanded parameter pack in a fold expression expands to an empty
sequence, the value of the expression is as follows; the program is
ill-formed if the operator is not listed in this table.
&& true
|| false
, void() */
tree
expand_empty_fold (tree t, tsubst_flags_t complain)
{
tree_code code = (tree_code)TREE_INT_CST_LOW (TREE_OPERAND (t, 0));
if (!FOLD_EXPR_MODIFY_P (t))
switch (code)
{
case TRUTH_ANDIF_EXPR:
return boolean_true_node;
case TRUTH_ORIF_EXPR:
return boolean_false_node;
case COMPOUND_EXPR:
return void_node;
default:
break;
}
if (complain & tf_error)
error_at (location_of (t),
"fold of empty expansion over %O", code);
return error_mark_node;
}
/* Given a fold-expression T and a current LEFT and RIGHT operand,
form an expression that combines the two terms using the
operator of T. */
static tree
fold_expression (tree t, tree left, tree right, tsubst_flags_t complain)
{
tree op = FOLD_EXPR_OP (t);
tree_code code = (tree_code)TREE_INT_CST_LOW (op);
// Handle compound assignment operators.
if (FOLD_EXPR_MODIFY_P (t))
return build_x_modify_expr (input_location, left, code, right, complain);
warning_sentinel s(warn_parentheses);
switch (code)
{
case COMPOUND_EXPR:
return build_x_compound_expr (input_location, left, right, complain);
default:
return build_x_binary_op (input_location, code,
left, TREE_CODE (left),
right, TREE_CODE (right),
/*overload=*/NULL,
complain);
}
}
/* Substitute ARGS into the pack of a fold expression T. */
static inline tree
tsubst_fold_expr_pack (tree t, tree args, tsubst_flags_t complain, tree in_decl)
{
return tsubst_pack_expansion (FOLD_EXPR_PACK (t), args, complain, in_decl);
}
/* Substitute ARGS into the pack of a fold expression T. */
static inline tree
tsubst_fold_expr_init (tree t, tree args, tsubst_flags_t complain, tree in_decl)
{
return tsubst_expr (FOLD_EXPR_INIT (t), args, complain, in_decl, false);
}
/* Expand a PACK of arguments into a grouped as left fold.
Given a pack containing elements A0, A1, ..., An and an
operator @, this builds the expression:
((A0 @ A1) @ A2) ... @ An
Note that PACK must not be empty.
The operator is defined by the original fold expression T. */
static tree
expand_left_fold (tree t, tree pack, tsubst_flags_t complain)
{
tree left = TREE_VEC_ELT (pack, 0);
for (int i = 1; i < TREE_VEC_LENGTH (pack); ++i)
{
tree right = TREE_VEC_ELT (pack, i);
left = fold_expression (t, left, right, complain);
}
return left;
}
/* Substitute into a unary left fold expression. */
static tree
tsubst_unary_left_fold (tree t, tree args, tsubst_flags_t complain,
tree in_decl)
{
tree pack = tsubst_fold_expr_pack (t, args, complain, in_decl);
if (pack == error_mark_node)
return error_mark_node;
if (PACK_EXPANSION_P (pack))
{
tree r = copy_node (t);
FOLD_EXPR_PACK (r) = pack;
return r;
}
if (TREE_VEC_LENGTH (pack) == 0)
return expand_empty_fold (t, complain);
else
return expand_left_fold (t, pack, complain);
}
/* Substitute into a binary left fold expression.
Do ths by building a single (non-empty) vector of argumnts and
building the expression from those elements. */
static tree
tsubst_binary_left_fold (tree t, tree args, tsubst_flags_t complain,
tree in_decl)
{
tree pack = tsubst_fold_expr_pack (t, args, complain, in_decl);
if (pack == error_mark_node)
return error_mark_node;
tree init = tsubst_fold_expr_init (t, args, complain, in_decl);
if (init == error_mark_node)
return error_mark_node;
if (PACK_EXPANSION_P (pack))
{
tree r = copy_node (t);
FOLD_EXPR_PACK (r) = pack;
FOLD_EXPR_INIT (r) = init;
return r;
}
tree vec = make_tree_vec (TREE_VEC_LENGTH (pack) + 1);
TREE_VEC_ELT (vec, 0) = init;
for (int i = 0; i < TREE_VEC_LENGTH (pack); ++i)
TREE_VEC_ELT (vec, i + 1) = TREE_VEC_ELT (pack, i);
return expand_left_fold (t, vec, complain);
}
/* Expand a PACK of arguments into a grouped as right fold.
Given a pack containing elementns A0, A1, ..., and an
operator @, this builds the expression:
A0@ ... (An-2 @ (An-1 @ An))
Note that PACK must not be empty.
The operator is defined by the original fold expression T. */
tree
expand_right_fold (tree t, tree pack, tsubst_flags_t complain)
{
// Build the expression.
int n = TREE_VEC_LENGTH (pack);
tree right = TREE_VEC_ELT (pack, n - 1);
for (--n; n != 0; --n)
{
tree left = TREE_VEC_ELT (pack, n - 1);
right = fold_expression (t, left, right, complain);
}
return right;
}
/* Substitute into a unary right fold expression. */
static tree
tsubst_unary_right_fold (tree t, tree args, tsubst_flags_t complain,
tree in_decl)
{
tree pack = tsubst_fold_expr_pack (t, args, complain, in_decl);
if (pack == error_mark_node)
return error_mark_node;
if (PACK_EXPANSION_P (pack))
{
tree r = copy_node (t);
FOLD_EXPR_PACK (r) = pack;
return r;
}
if (TREE_VEC_LENGTH (pack) == 0)
return expand_empty_fold (t, complain);
else
return expand_right_fold (t, pack, complain);
}
/* Substitute into a binary right fold expression.
Do ths by building a single (non-empty) vector of arguments and
building the expression from those elements. */
static tree
tsubst_binary_right_fold (tree t, tree args, tsubst_flags_t complain,
tree in_decl)
{
tree pack = tsubst_fold_expr_pack (t, args, complain, in_decl);
if (pack == error_mark_node)
return error_mark_node;
tree init = tsubst_fold_expr_init (t, args, complain, in_decl);
if (init == error_mark_node)
return error_mark_node;
if (PACK_EXPANSION_P (pack))
{
tree r = copy_node (t);
FOLD_EXPR_PACK (r) = pack;
FOLD_EXPR_INIT (r) = init;
return r;
}
int n = TREE_VEC_LENGTH (pack);
tree vec = make_tree_vec (n + 1);
for (int i = 0; i < n; ++i)
TREE_VEC_ELT (vec, i) = TREE_VEC_ELT (pack, i);
TREE_VEC_ELT (vec, n) = init;
return expand_right_fold (t, vec, complain);
}
/* Walk through the pattern of a pack expansion, adding everything in
local_specializations to a list. */
struct el_data
{
hash_set<tree> internal;
tree extra;
tsubst_flags_t complain;
el_data (tsubst_flags_t c)
: extra (NULL_TREE), complain (c) {}
};
static tree
extract_locals_r (tree *tp, int */*walk_subtrees*/, void *data_)
{
el_data &data = *reinterpret_cast<el_data*>(data_);
tree *extra = &data.extra;
tsubst_flags_t complain = data.complain;
if (TYPE_P (*tp) && typedef_variant_p (*tp))
/* Remember local typedefs (85214). */
tp = &TYPE_NAME (*tp);
if (TREE_CODE (*tp) == DECL_EXPR)
{
tree decl = DECL_EXPR_DECL (*tp);
data.internal.add (decl);
if (VAR_P (decl)
&& DECL_DECOMPOSITION_P (decl)
&& TREE_TYPE (decl) != error_mark_node)
{
gcc_assert (DECL_NAME (decl) == NULL_TREE);
for (tree decl2 = DECL_CHAIN (decl);
decl2
&& VAR_P (decl2)
&& DECL_DECOMPOSITION_P (decl2)
&& DECL_NAME (decl2)
&& TREE_TYPE (decl2) != error_mark_node;
decl2 = DECL_CHAIN (decl2))
{
gcc_assert (DECL_DECOMP_BASE (decl2) == decl);
data.internal.add (decl2);
}
}
}
else if (tree spec = retrieve_local_specialization (*tp))
{
if (data.internal.contains (*tp))
/* Don't mess with variables declared within the pattern. */
return NULL_TREE;
if (TREE_CODE (spec) == NONTYPE_ARGUMENT_PACK)
{
/* Maybe pull out the PARM_DECL for a partial instantiation. */
tree args = ARGUMENT_PACK_ARGS (spec);
if (TREE_VEC_LENGTH (args) == 1)
{
tree elt = TREE_VEC_ELT (args, 0);
if (PACK_EXPANSION_P (elt))
elt = PACK_EXPANSION_PATTERN (elt);
if (DECL_PACK_P (elt))
spec = elt;
}
if (TREE_CODE (spec) == NONTYPE_ARGUMENT_PACK)
{
/* Handle lambda capture here, since we aren't doing any
substitution now, and so tsubst_copy won't call
process_outer_var_ref. */
tree args = ARGUMENT_PACK_ARGS (spec);
int len = TREE_VEC_LENGTH (args);
for (int i = 0; i < len; ++i)
{
tree arg = TREE_VEC_ELT (args, i);
tree carg = arg;
if (outer_automatic_var_p (arg))
carg = process_outer_var_ref (arg, complain);
if (carg != arg)
{
/* Make a new NONTYPE_ARGUMENT_PACK of the capture
proxies. */
if (i == 0)
{
spec = copy_node (spec);
args = copy_node (args);
SET_ARGUMENT_PACK_ARGS (spec, args);
register_local_specialization (spec, *tp);
}
TREE_VEC_ELT (args, i) = carg;
}
}
}
}
if (outer_automatic_var_p (spec))
spec = process_outer_var_ref (spec, complain);
*extra = tree_cons (*tp, spec, *extra);
}
return NULL_TREE;
}
static tree
extract_local_specs (tree pattern, tsubst_flags_t complain)
{
el_data data (complain);
cp_walk_tree_without_duplicates (&pattern, extract_locals_r, &data);
return data.extra;
}
/* Extract any uses of local_specializations from PATTERN and add them to ARGS
for use in PACK_EXPANSION_EXTRA_ARGS. */
tree
build_extra_args (tree pattern, tree args, tsubst_flags_t complain)
{
tree extra = args;
if (local_specializations)
if (tree locals = extract_local_specs (pattern, complain))
extra = tree_cons (NULL_TREE, extra, locals);
return extra;
}
/* Apply any local specializations from PACK_EXPANSION_EXTRA_ARGS and add the
normal template args to ARGS. */
tree
add_extra_args (tree extra, tree args)
{
if (extra && TREE_CODE (extra) == TREE_LIST)
{
for (tree elt = TREE_CHAIN (extra); elt; elt = TREE_CHAIN (elt))
{
/* The partial instantiation involved local declarations collected in
extract_local_specs; map from the general template to our local
context. */
tree gen = TREE_PURPOSE (elt);
tree inst = TREE_VALUE (elt);
if (DECL_P (inst))
if (tree local = retrieve_local_specialization (inst))
inst = local;
/* else inst is already a full instantiation of the pack. */
register_local_specialization (inst, gen);
}
gcc_assert (!TREE_PURPOSE (extra));
extra = TREE_VALUE (extra);
}
return add_to_template_args (extra, args);
}
/* Substitute ARGS into T, which is an pack expansion
(i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
(if only a partial substitution could be performed) or
ERROR_MARK_NODE if there was an error. */
tree
tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
tree in_decl)
{
tree pattern;
tree pack, packs = NULL_TREE;
bool unsubstituted_packs = false;
bool unsubstituted_fn_pack = false;
int i, len = -1;
tree result;
hash_map<tree, tree> *saved_local_specializations = NULL;
bool need_local_specializations = false;
int levels;
gcc_assert (PACK_EXPANSION_P (t));
pattern = PACK_EXPANSION_PATTERN (t);
/* Add in any args remembered from an earlier partial instantiation. */
args = add_extra_args (PACK_EXPANSION_EXTRA_ARGS (t), args);
levels = TMPL_ARGS_DEPTH (args);
/* Determine the argument packs that will instantiate the parameter
packs used in the expansion expression. While we're at it,
compute the number of arguments to be expanded and make sure it
is consistent. */
for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
pack = TREE_CHAIN (pack))
{
tree parm_pack = TREE_VALUE (pack);
tree arg_pack = NULL_TREE;
tree orig_arg = NULL_TREE;
int level = 0;
if (TREE_CODE (parm_pack) == BASES)
{
gcc_assert (parm_pack == pattern);
if (BASES_DIRECT (parm_pack))
return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
args, complain,
in_decl, false),
complain);
else
return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
args, complain, in_decl,
false), complain);
}
else if (builtin_pack_call_p (parm_pack))
{
if (parm_pack != pattern)
{
if (complain & tf_error)
sorry ("%qE is not the entire pattern of the pack expansion",
parm_pack);
return error_mark_node;
}
return expand_builtin_pack_call (parm_pack, args,
complain, in_decl);
}
else if (TREE_CODE (parm_pack) == PARM_DECL)
{
/* We know we have correct local_specializations if this
expansion is at function scope, or if we're dealing with a
local parameter in a requires expression; for the latter,
tsubst_requires_expr set it up appropriately. */
if (PACK_EXPANSION_LOCAL_P (t) || CONSTRAINT_VAR_P (parm_pack))
arg_pack = retrieve_local_specialization (parm_pack);
else
/* We can't rely on local_specializations for a parameter
name used later in a function declaration (such as in a
late-specified return type). Even if it exists, it might
have the wrong value for a recursive call. */
need_local_specializations = true;
if (!arg_pack)
{
/* This parameter pack was used in an unevaluated context. Just
make a dummy decl, since it's only used for its type. */
++cp_unevaluated_operand;
arg_pack = tsubst_decl (parm_pack, args, complain);
--cp_unevaluated_operand;
if (arg_pack && DECL_PACK_P (arg_pack))
/* Partial instantiation of the parm_pack, we can't build
up an argument pack yet. */
arg_pack = NULL_TREE;
else
arg_pack = make_fnparm_pack (arg_pack);
}
else if (argument_pack_element_is_expansion_p (arg_pack, 0))
/* This argument pack isn't fully instantiated yet. We set this
flag rather than clear arg_pack because we do want to do the
optimization below, and we don't want to substitute directly
into the pattern (as that would expose a NONTYPE_ARGUMENT_PACK
where it isn't expected). */
unsubstituted_fn_pack = true;
}
else if (is_capture_proxy (parm_pack))
{
arg_pack = retrieve_local_specialization (parm_pack);
if (argument_pack_element_is_expansion_p (arg_pack, 0))
unsubstituted_fn_pack = true;
}
else
{
int idx;
template_parm_level_and_index (parm_pack, &level, &idx);
if (level <= levels)
arg_pack = TMPL_ARG (args, level, idx);
}
orig_arg = arg_pack;
if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
/* This can only happen if we forget to expand an argument
pack somewhere else. Just return an error, silently. */
{
result = make_tree_vec (1);
TREE_VEC_ELT (result, 0) = error_mark_node;
return result;
}
if (arg_pack)
{
int my_len =
TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
/* Don't bother trying to do a partial substitution with
incomplete packs; we'll try again after deduction. */
if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
return t;
if (len < 0)
len = my_len;
else if (len != my_len
&& !unsubstituted_fn_pack)
{
if (!(complain & tf_error))
/* Fail quietly. */;
else if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
error ("mismatched argument pack lengths while expanding %qT",
pattern);
else
error ("mismatched argument pack lengths while expanding %qE",
pattern);
return error_mark_node;
}
/* Keep track of the parameter packs and their corresponding
argument packs. */
packs = tree_cons (parm_pack, arg_pack, packs);
TREE_TYPE (packs) = orig_arg;
}
else
{
/* We can't substitute for this parameter pack. We use a flag as
well as the missing_level counter because function parameter
packs don't have a level. */
gcc_assert (processing_template_decl || is_auto (parm_pack));
unsubstituted_packs = true;
}
}
/* If the expansion is just T..., return the matching argument pack, unless
we need to call convert_from_reference on all the elements. This is an
important optimization; see c++/68422. */
if (!unsubstituted_packs
&& TREE_PURPOSE (packs) == pattern)
{
tree args = ARGUMENT_PACK_ARGS (TREE_VALUE (packs));
/* If the argument pack is a single pack expansion, pull it out. */
if (TREE_VEC_LENGTH (args) == 1
&& pack_expansion_args_count (args))
return TREE_VEC_ELT (args, 0);
/* Types need no adjustment, nor does sizeof..., and if we still have
some pack expansion args we won't do anything yet. */
if (TREE_CODE (t) == TYPE_PACK_EXPANSION
|| PACK_EXPANSION_SIZEOF_P (t)
|| pack_expansion_args_count (args))
return args;
/* Also optimize expression pack expansions if we can tell that the
elements won't have reference type. */
tree type = TREE_TYPE (pattern);
if (type && !TYPE_REF_P (type)
&& !PACK_EXPANSION_P (type)
&& !WILDCARD_TYPE_P (type))
return args;
/* Otherwise use the normal path so we get convert_from_reference. */
}
/* We cannot expand this expansion expression, because we don't have
all of the argument packs we need. */
if (use_pack_expansion_extra_args_p (packs, len, unsubstituted_packs))
{
/* We got some full packs, but we can't substitute them in until we
have values for all the packs. So remember these until then. */
t = make_pack_expansion (pattern, complain);
PACK_EXPANSION_EXTRA_ARGS (t)
= build_extra_args (pattern, args, complain);
return t;
}
else if (unsubstituted_packs)
{
/* There were no real arguments, we're just replacing a parameter
pack with another version of itself. Substitute into the
pattern and return a PACK_EXPANSION_*. The caller will need to
deal with that. */
if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
result = tsubst_expr (pattern, args, complain, in_decl,
/*integral_constant_expression_p=*/false);
else
result = tsubst (pattern, args, complain, in_decl);
result = make_pack_expansion (result, complain);
if (PACK_EXPANSION_AUTO_P (t))
{
/* This is a fake auto... pack expansion created in add_capture with
_PACKS that don't appear in the pattern. Copy one over. */
packs = PACK_EXPANSION_PARAMETER_PACKS (t);
pack = retrieve_local_specialization (TREE_VALUE (packs));
gcc_checking_assert (DECL_PACK_P (pack));
PACK_EXPANSION_PARAMETER_PACKS (result)
= build_tree_list (NULL_TREE, pack);
PACK_EXPANSION_AUTO_P (result) = true;
}
return result;
}
gcc_assert (len >= 0);
if (need_local_specializations)
{
/* We're in a late-specified return type, so create our own local
specializations map; the current map is either NULL or (in the
case of recursive unification) might have bindings that we don't
want to use or alter. */
saved_local_specializations = local_specializations;
local_specializations = new hash_map<tree, tree>;
}
/* For each argument in each argument pack, substitute into the
pattern. */
result = make_tree_vec (len);
tree elem_args = copy_template_args (args);
for (i = 0; i < len; ++i)
{
t = gen_elem_of_pack_expansion_instantiation (pattern, packs,
i,
elem_args, complain,
in_decl);
TREE_VEC_ELT (result, i) = t;
if (t == error_mark_node)
{
result = error_mark_node;
break;
}
}
/* Update ARGS to restore the substitution from parameter packs to
their argument packs. */
for (pack = packs; pack; pack = TREE_CHAIN (pack))
{
tree parm = TREE_PURPOSE (pack);
if (TREE_CODE (parm) == PARM_DECL
|| VAR_P (parm)
|| TREE_CODE (parm) == FIELD_DECL)
register_local_specialization (TREE_TYPE (pack), parm);
else
{
int idx, level;
if (TREE_VALUE (pack) == NULL_TREE)
continue;
template_parm_level_and_index (parm, &level, &idx);
/* Update the corresponding argument. */
if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
TREE_TYPE (pack);
else
TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
}
}
if (need_local_specializations)
{
delete local_specializations;
local_specializations = saved_local_specializations;
}
/* If the dependent pack arguments were such that we end up with only a
single pack expansion again, there's no need to keep it in a TREE_VEC. */
if (len == 1 && TREE_CODE (result) == TREE_VEC
&& PACK_EXPANSION_P (TREE_VEC_ELT (result, 0)))
return TREE_VEC_ELT (result, 0);
return result;
}
/* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
TMPL. We do this using DECL_PARM_INDEX, which should work even with
parameter packs; all parms generated from a function parameter pack will
have the same DECL_PARM_INDEX. */
tree
get_pattern_parm (tree parm, tree tmpl)
{
tree pattern = DECL_TEMPLATE_RESULT (tmpl);
tree patparm;
if (DECL_ARTIFICIAL (parm))
{
for (patparm = DECL_ARGUMENTS (pattern);
patparm; patparm = DECL_CHAIN (patparm))
if (DECL_ARTIFICIAL (patparm)
&& DECL_NAME (parm) == DECL_NAME (patparm))
break;
}
else
{
patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
gcc_assert (DECL_PARM_INDEX (patparm)
== DECL_PARM_INDEX (parm));
}
return patparm;
}
/* Make an argument pack out of the TREE_VEC VEC. */
static tree
make_argument_pack (tree vec)
{
tree pack;
tree elt = TREE_VEC_ELT (vec, 0);
if (TYPE_P (elt))
pack = cxx_make_type (TYPE_ARGUMENT_PACK);
else
{
pack = make_node (NONTYPE_ARGUMENT_PACK);
TREE_CONSTANT (pack) = 1;
}
SET_ARGUMENT_PACK_ARGS (pack, vec);
return pack;
}
/* Return an exact copy of template args T that can be modified
independently. */
static tree
copy_template_args (tree t)
{
if (t == error_mark_node)
return t;
int len = TREE_VEC_LENGTH (t);
tree new_vec = make_tree_vec (len);
for (int i = 0; i < len; ++i)
{
tree elt = TREE_VEC_ELT (t, i);
if (elt && TREE_CODE (elt) == TREE_VEC)
elt = copy_template_args (elt);
TREE_VEC_ELT (new_vec, i) = elt;
}
NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_vec)
= NON_DEFAULT_TEMPLATE_ARGS_COUNT (t);
return new_vec;
}
/* Substitute ARGS into the vector or list of template arguments T. */
static tree
tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
{
tree orig_t = t;
int len, need_new = 0, i, expanded_len_adjust = 0, out;
tree *elts;
if (t == error_mark_node)
return error_mark_node;
len = TREE_VEC_LENGTH (t);
elts = XALLOCAVEC (tree, len);
for (i = 0; i < len; i++)
{
tree orig_arg = TREE_VEC_ELT (t, i);
tree new_arg;
if (TREE_CODE (orig_arg) == TREE_VEC)
new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
else if (PACK_EXPANSION_P (orig_arg))
{
/* Substitute into an expansion expression. */
new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
if (TREE_CODE (new_arg) == TREE_VEC)
/* Add to the expanded length adjustment the number of
expanded arguments. We subtract one from this
measurement, because the argument pack expression
itself is already counted as 1 in
LEN. EXPANDED_LEN_ADJUST can actually be negative, if
the argument pack is empty. */
expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
}
else if (ARGUMENT_PACK_P (orig_arg))
{
/* Substitute into each of the arguments. */
new_arg = TYPE_P (orig_arg)
? cxx_make_type (TREE_CODE (orig_arg))
: make_node (TREE_CODE (orig_arg));
tree pack_args = tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
args, complain, in_decl);
if (pack_args == error_mark_node)
new_arg = error_mark_node;
else
SET_ARGUMENT_PACK_ARGS (new_arg, pack_args);
if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK)
TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
}
else
new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
if (new_arg == error_mark_node)
return error_mark_node;
elts[i] = new_arg;
if (new_arg != orig_arg)
need_new = 1;
}
if (!need_new)
return t;
/* Make space for the expanded arguments coming from template
argument packs. */
t = make_tree_vec (len + expanded_len_adjust);
/* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
arguments for a member template.
In that case each TREE_VEC in ORIG_T represents a level of template
arguments, and ORIG_T won't carry any non defaulted argument count.
It will rather be the nested TREE_VECs that will carry one.
In other words, ORIG_T carries a non defaulted argument count only
if it doesn't contain any nested TREE_VEC. */
if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
{
int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
count += expanded_len_adjust;
SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
}
for (i = 0, out = 0; i < len; i++)
{
if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
|| ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
&& TREE_CODE (elts[i]) == TREE_VEC)
{
int idx;
/* Now expand the template argument pack "in place". */
for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
}
else
{
TREE_VEC_ELT (t, out) = elts[i];
out++;
}
}
return t;
}
/* Substitute ARGS into one level PARMS of template parameters. */
static tree
tsubst_template_parms_level (tree parms, tree args, tsubst_flags_t complain)
{
if (parms == error_mark_node)
return error_mark_node;
tree new_vec = make_tree_vec (TREE_VEC_LENGTH (parms));
for (int i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
{
tree tuple = TREE_VEC_ELT (parms, i);
if (tuple == error_mark_node)
continue;
TREE_VEC_ELT (new_vec, i) =
tsubst_template_parm (tuple, args, complain);
}
return new_vec;
}
/* Return the result of substituting ARGS into the template parameters
given by PARMS. If there are m levels of ARGS and m + n levels of
PARMS, then the result will contain n levels of PARMS. For
example, if PARMS is `template <class T> template <class U>
template <T*, U, class V>' and ARGS is {{int}, {double}} then the
result will be `template <int*, double, class V>'. */
static tree
tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
{
tree r = NULL_TREE;
tree* new_parms;
/* When substituting into a template, we must set
PROCESSING_TEMPLATE_DECL as the template parameters may be
dependent if they are based on one-another, and the dependency
predicates are short-circuit outside of templates. */
++processing_template_decl;
for (new_parms = &r;
parms && TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
new_parms = &(TREE_CHAIN (*new_parms)),
parms = TREE_CHAIN (parms))
{
tree new_vec = tsubst_template_parms_level (TREE_VALUE (parms),
args, complain);
*new_parms =
tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
- TMPL_ARGS_DEPTH (args)),
new_vec, NULL_TREE);
}
--processing_template_decl;
return r;
}
/* Return the result of substituting ARGS into one template parameter
given by T. T Must be a TREE_LIST which TREE_VALUE is the template
parameter and which TREE_PURPOSE is the default argument of the
template parameter. */
static tree
tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
{
tree default_value, parm_decl;
if (args == NULL_TREE
|| t == NULL_TREE
|| t == error_mark_node)
return t;
gcc_assert (TREE_CODE (t) == TREE_LIST);
default_value = TREE_PURPOSE (t);
parm_decl = TREE_VALUE (t);
parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
if (TREE_CODE (parm_decl) == PARM_DECL
&& invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
parm_decl = error_mark_node;
default_value = tsubst_template_arg (default_value, args,
complain, NULL_TREE);
return build_tree_list (default_value, parm_decl);
}
/* Substitute the ARGS into the indicated aggregate (or enumeration)
type T. If T is not an aggregate or enumeration type, it is
handled as if by tsubst. IN_DECL is as for tsubst. If
ENTERING_SCOPE is nonzero, T is the context for a template which
we are presently tsubst'ing. Return the substituted value. */
static tree
tsubst_aggr_type (tree t,
tree args,
tsubst_flags_t complain,
tree in_decl,
int entering_scope)
{
if (t == NULL_TREE)
return NULL_TREE;
switch (TREE_CODE (t))
{
case RECORD_TYPE:
if (TYPE_PTRMEMFUNC_P (t))
return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
/* Fall through. */
case ENUMERAL_TYPE:
case UNION_TYPE:
if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
{
tree argvec;
tree context;
tree r;
/* In "sizeof(X<I>)" we need to evaluate "I". */
cp_evaluated ev;
/* First, determine the context for the type we are looking
up. */
context = TYPE_CONTEXT (t);
if (context && TYPE_P (context))
{
context = tsubst_aggr_type (context, args, complain,
in_decl, /*entering_scope=*/1);
/* If context is a nested class inside a class template,
it may still need to be instantiated (c++/33959). */
context = complete_type (context);
}
/* Then, figure out what arguments are appropriate for the
type we are trying to find. For example, given:
template <class T> struct S;
template <class T, class U> void f(T, U) { S<U> su; }
and supposing that we are instantiating f<int, double>,
then our ARGS will be {int, double}, but, when looking up
S we only want {double}. */
argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
complain, in_decl);
if (argvec == error_mark_node)
r = error_mark_node;
else
{
r = lookup_template_class (t, argvec, in_decl, context,
entering_scope, complain);
r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
}
return r;
}
else
/* This is not a template type, so there's nothing to do. */
return t;
default:
return tsubst (t, args, complain, in_decl);
}
}
static GTY((cache)) tree_cache_map *defarg_inst;
/* Substitute into the default argument ARG (a default argument for
FN), which has the indicated TYPE. */
tree
tsubst_default_argument (tree fn, int parmnum, tree type, tree arg,
tsubst_flags_t complain)
{
int errs = errorcount + sorrycount;
/* This can happen in invalid code. */
if (TREE_CODE (arg) == DEFAULT_ARG)
return arg;
tree parm = FUNCTION_FIRST_USER_PARM (fn);
parm = chain_index (parmnum, parm);
tree parmtype = TREE_TYPE (parm);
if (DECL_BY_REFERENCE (parm))
parmtype = TREE_TYPE (parmtype);
if (parmtype == error_mark_node)
return error_mark_node;
gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, parmtype));
tree *slot;
if (defarg_inst && (slot = defarg_inst->get (parm)))
return *slot;
/* This default argument came from a template. Instantiate the
default argument here, not in tsubst. In the case of
something like:
template <class T>
struct S {
static T t();
void f(T = t());
};
we must be careful to do name lookup in the scope of S<T>,
rather than in the current class. */
push_to_top_level ();
push_access_scope (fn);
push_deferring_access_checks (dk_no_deferred);
start_lambda_scope (parm);
/* The default argument expression may cause implicitly defined
member functions to be synthesized, which will result in garbage
collection. We must treat this situation as if we were within
the body of function so as to avoid collecting live data on the
stack. */
++function_depth;
arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
complain, NULL_TREE,
/*integral_constant_expression_p=*/false);
--function_depth;
finish_lambda_scope ();
/* Make sure the default argument is reasonable. */
arg = check_default_argument (type, arg, complain);
if (errorcount+sorrycount > errs
&& (complain & tf_warning_or_error))
inform (input_location,
" when instantiating default argument for call to %qD", fn);
pop_deferring_access_checks ();
pop_access_scope (fn);
pop_from_top_level ();
if (arg != error_mark_node && !cp_unevaluated_operand)
{
if (!defarg_inst)
defarg_inst = tree_cache_map::create_ggc (37);
defarg_inst->put (parm, arg);
}
return arg;
}
/* Substitute into all the default arguments for FN. */
static void
tsubst_default_arguments (tree fn, tsubst_flags_t complain)
{
tree arg;
tree tmpl_args;
tmpl_args = DECL_TI_ARGS (fn);
/* If this function is not yet instantiated, we certainly don't need
its default arguments. */
if (uses_template_parms (tmpl_args))
return;
/* Don't do this again for clones. */
if (DECL_CLONED_FUNCTION_P (fn))
return;
int i = 0;
for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
arg;
arg = TREE_CHAIN (arg), ++i)
if (TREE_PURPOSE (arg))
TREE_PURPOSE (arg) = tsubst_default_argument (fn, i,
TREE_VALUE (arg),
TREE_PURPOSE (arg),
complain);
}
/* Hash table mapping a FUNCTION_DECL to its dependent explicit-specifier. */
static GTY((cache)) tree_cache_map *explicit_specifier_map;
/* Store a pair to EXPLICIT_SPECIFIER_MAP. */
void
store_explicit_specifier (tree v, tree t)
{
if (!explicit_specifier_map)
explicit_specifier_map = tree_cache_map::create_ggc (37);
DECL_HAS_DEPENDENT_EXPLICIT_SPEC_P (v) = true;
explicit_specifier_map->put (v, t);
}
/* Lookup an element in EXPLICIT_SPECIFIER_MAP. */
static tree
lookup_explicit_specifier (tree v)
{
return *explicit_specifier_map->get (v);
}
/* Subroutine of tsubst_decl for the case when T is a FUNCTION_DECL. */
static tree
tsubst_function_decl (tree t, tree args, tsubst_flags_t complain,
tree lambda_fntype)
{
tree gen_tmpl, argvec;
hashval_t hash = 0;
tree in_decl = t;
/* Nobody should be tsubst'ing into non-template functions. */
gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
{
/* If T is not dependent, just return it. */
if (!uses_template_parms (DECL_TI_ARGS (t))
&& !LAMBDA_FUNCTION_P (t))
return t;
/* Calculate the most general template of which R is a
specialization. */
gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
/* We're substituting a lambda function under tsubst_lambda_expr but not
directly from it; find the matching function we're already inside.
But don't do this if T is a generic lambda with a single level of
template parms, as in that case we're doing a normal instantiation. */
if (LAMBDA_FUNCTION_P (t) && !lambda_fntype
&& (!generic_lambda_fn_p (t)
|| TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl)) > 1))
return enclosing_instantiation_of (t);
/* Calculate the complete set of arguments used to
specialize R. */
argvec = tsubst_template_args (DECL_TI_ARGS
(DECL_TEMPLATE_RESULT
(DECL_TI_TEMPLATE (t))),
args, complain, in_decl);
if (argvec == error_mark_node)
return error_mark_node;
/* Check to see if we already have this specialization. */
if (!lambda_fntype)
{
hash = hash_tmpl_and_args (gen_tmpl, argvec);
if (tree spec = retrieve_specialization (gen_tmpl, argvec, hash))
return spec;
}
/* We can see more levels of arguments than parameters if
there was a specialization of a member template, like
this:
template <class T> struct S { template <class U> void f(); }
template <> template <class U> void S<int>::f(U);
Here, we'll be substituting into the specialization,
because that's where we can find the code we actually
want to generate, but we'll have enough arguments for
the most general template.
We also deal with the peculiar case:
template <class T> struct S {
template <class U> friend void f();
};
template <class U> void f() {}
template S<int>;
template void f<double>();
Here, the ARGS for the instantiation of will be {int,
double}. But, we only need as many ARGS as there are
levels of template parameters in CODE_PATTERN. We are
careful not to get fooled into reducing the ARGS in
situations like:
template <class T> struct S { template <class U> void f(U); }
template <class T> template <> void S<T>::f(int) {}
which we can spot because the pattern will be a
specialization in this case. */
int args_depth = TMPL_ARGS_DEPTH (args);
int parms_depth =
TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
if (args_depth > parms_depth && !DECL_TEMPLATE_SPECIALIZATION (t))
args = get_innermost_template_args (args, parms_depth);
}
else
{
/* This special case arises when we have something like this:
template <class T> struct S {
friend void f<int>(int, double);
};
Here, the DECL_TI_TEMPLATE for the friend declaration
will be an IDENTIFIER_NODE. We are being called from
tsubst_friend_function, and we want only to create a
new decl (R) with appropriate types so that we can call
determine_specialization. */
gen_tmpl = NULL_TREE;
argvec = NULL_TREE;
}
tree closure = (lambda_fntype ? TYPE_METHOD_BASETYPE (lambda_fntype)
: NULL_TREE);
tree ctx = closure ? closure : DECL_CONTEXT (t);
bool member = ctx && TYPE_P (ctx);
if (member && !closure)
ctx = tsubst_aggr_type (ctx, args,
complain, t, /*entering_scope=*/1);
tree type = (lambda_fntype ? lambda_fntype
: tsubst (TREE_TYPE (t), args,
complain | tf_fndecl_type, in_decl));
if (type == error_mark_node)
return error_mark_node;
/* If we hit excessive deduction depth, the type is bogus even if
it isn't error_mark_node, so don't build a decl. */
if (excessive_deduction_depth)
return error_mark_node;
/* We do NOT check for matching decls pushed separately at this
point, as they may not represent instantiations of this
template, and in any case are considered separate under the
discrete model. */
tree r = copy_decl (t);
DECL_USE_TEMPLATE (r) = 0;
TREE_TYPE (r) = type;
/* Clear out the mangled name and RTL for the instantiation. */
SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
SET_DECL_RTL (r, NULL);
/* Leave DECL_INITIAL set on deleted instantiations. */
if (!DECL_DELETED_FN (r))
DECL_INITIAL (r) = NULL_TREE;
DECL_CONTEXT (r) = ctx;
/* Handle explicit(dependent-expr). */
if (DECL_HAS_DEPENDENT_EXPLICIT_SPEC_P (t))
{
tree spec = lookup_explicit_specifier (t);
spec = tsubst_copy_and_build (spec, args, complain, in_decl,
/*function_p=*/false,
/*i_c_e_p=*/true);
spec = build_explicit_specifier (spec, complain);
DECL_NONCONVERTING_P (r) = (spec == boolean_true_node);
}
/* OpenMP UDRs have the only argument a reference to the declared
type. We want to diagnose if the declared type is a reference,
which is invalid, but as references to references are usually
quietly merged, diagnose it here. */
if (DECL_OMP_DECLARE_REDUCTION_P (t))
{
tree argtype
= TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (t))));
argtype = tsubst (argtype, args, complain, in_decl);
if (TYPE_REF_P (argtype))
error_at (DECL_SOURCE_LOCATION (t),
"reference type %qT in "
"%<#pragma omp declare reduction%>", argtype);
if (strchr (IDENTIFIER_POINTER (DECL_NAME (t)), '~') == NULL)
DECL_NAME (r) = omp_reduction_id (ERROR_MARK, DECL_NAME (t),
argtype);
}
if (member && DECL_CONV_FN_P (r))
/* Type-conversion operator. Reconstruct the name, in
case it's the name of one of the template's parameters. */
DECL_NAME (r) = make_conv_op_name (TREE_TYPE (type));
tree parms = DECL_ARGUMENTS (t);
if (closure)
parms = DECL_CHAIN (parms);
parms = tsubst (parms, args, complain, t);
for (tree parm = parms; parm; parm = DECL_CHAIN (parm))
DECL_CONTEXT (parm) = r;
if (closure)
{
tree tparm = build_this_parm (r, closure, type_memfn_quals (type));
DECL_CHAIN (tparm) = parms;
parms = tparm;
}
DECL_ARGUMENTS (r) = parms;
DECL_RESULT (r) = NULL_TREE;
TREE_STATIC (r) = 0;
TREE_PUBLIC (r) = TREE_PUBLIC (t);
DECL_EXTERNAL (r) = 1;
/* If this is an instantiation of a function with internal
linkage, we already know what object file linkage will be
assigned to the instantiation. */
DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
DECL_DEFER_OUTPUT (r) = 0;
DECL_CHAIN (r) = NULL_TREE;
DECL_PENDING_INLINE_INFO (r) = 0;
DECL_PENDING_INLINE_P (r) = 0;
DECL_SAVED_TREE (r) = NULL_TREE;
DECL_STRUCT_FUNCTION (r) = NULL;
TREE_USED (r) = 0;
/* We'll re-clone as appropriate in instantiate_template. */
DECL_CLONED_FUNCTION (r) = NULL_TREE;
/* If we aren't complaining now, return on error before we register
the specialization so that we'll complain eventually. */
if ((complain & tf_error) == 0
&& IDENTIFIER_ANY_OP_P (DECL_NAME (r))
&& !grok_op_properties (r, /*complain=*/false))
return error_mark_node;
/* When instantiating a constrained member, substitute
into the constraints to create a new constraint. */
if (tree ci = get_constraints (t))
if (member)
{
ci = tsubst_constraint_info (ci, argvec, complain, NULL_TREE);
set_constraints (r, ci);
}
if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
SET_DECL_FRIEND_CONTEXT (r,
tsubst (DECL_FRIEND_CONTEXT (t),
args, complain, in_decl));
/* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
this in the special friend case mentioned above where
GEN_TMPL is NULL. */
if (gen_tmpl && !closure)
{
DECL_TEMPLATE_INFO (r)
= build_template_info (gen_tmpl, argvec);
SET_DECL_IMPLICIT_INSTANTIATION (r);
tree new_r
= register_specialization (r, gen_tmpl, argvec, false, hash);
if (new_r != r)
/* We instantiated this while substituting into
the type earlier (template/friend54.C). */
return new_r;
/* We're not supposed to instantiate default arguments
until they are called, for a template. But, for a
declaration like:
template <class T> void f ()
{ extern void g(int i = T()); }
we should do the substitution when the template is
instantiated. We handle the member function case in
instantiate_class_template since the default arguments
might refer to other members of the class. */
if (!member
&& !PRIMARY_TEMPLATE_P (gen_tmpl)
&& !uses_template_parms (argvec))
tsubst_default_arguments (r, complain);
}
else
DECL_TEMPLATE_INFO (r) = NULL_TREE;
/* Copy the list of befriending classes. */
for (tree *friends = &DECL_BEFRIENDING_CLASSES (r);
*friends;
friends = &TREE_CHAIN (*friends))
{
*friends = copy_node (*friends);
TREE_VALUE (*friends)
= tsubst (TREE_VALUE (*friends), args, complain, in_decl);
}
if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
{
maybe_retrofit_in_chrg (r);
if (DECL_CONSTRUCTOR_P (r) && !grok_ctor_properties (ctx, r))
return error_mark_node;
/* If this is an instantiation of a member template, clone it.
If it isn't, that'll be handled by
clone_constructors_and_destructors. */
if (PRIMARY_TEMPLATE_P (gen_tmpl))
clone_function_decl (r, /*update_methods=*/false);
}
else if ((complain & tf_error) != 0
&& IDENTIFIER_ANY_OP_P (DECL_NAME (r))
&& !grok_op_properties (r, /*complain=*/true))
return error_mark_node;
/* Possibly limit visibility based on template args. */
DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
if (DECL_VISIBILITY_SPECIFIED (t))
{
DECL_VISIBILITY_SPECIFIED (r) = 0;
DECL_ATTRIBUTES (r)
= remove_attribute ("visibility", DECL_ATTRIBUTES (r));
}
determine_visibility (r);
if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
&& !processing_template_decl)
defaulted_late_check (r);
apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
args, complain, in_decl);
return r;
}
/* Subroutine of tsubst_decl for the case when T is a TEMPLATE_DECL. */
static tree
tsubst_template_decl (tree t, tree args, tsubst_flags_t complain,
tree lambda_fntype)
{
/* We can get here when processing a member function template,
member class template, or template template parameter. */
tree decl = DECL_TEMPLATE_RESULT (t);
tree in_decl = t;
tree spec;
tree tmpl_args;
tree full_args;
tree r;
hashval_t hash = 0;
if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
{
/* Template template parameter is treated here. */
tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
if (new_type == error_mark_node)
r = error_mark_node;
/* If we get a real template back, return it. This can happen in
the context of most_specialized_partial_spec. */
else if (TREE_CODE (new_type) == TEMPLATE_DECL)
r = new_type;
else
/* The new TEMPLATE_DECL was built in
reduce_template_parm_level. */
r = TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (new_type);
return r;
}
if (!lambda_fntype)
{
/* We might already have an instance of this template.
The ARGS are for the surrounding class type, so the
full args contain the tsubst'd args for the context,
plus the innermost args from the template decl. */
tmpl_args = DECL_CLASS_TEMPLATE_P (t)
? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
: DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
/* Because this is a template, the arguments will still be
dependent, even after substitution. If
PROCESSING_TEMPLATE_DECL is not set, the dependency
predicates will short-circuit. */
++processing_template_decl;
full_args = tsubst_template_args (tmpl_args, args,
complain, in_decl);
--processing_template_decl;
if (full_args == error_mark_node)
return error_mark_node;
/* If this is a default template template argument,
tsubst might not have changed anything. */
if (full_args == tmpl_args)
return t;
hash = hash_tmpl_and_args (t, full_args);
spec = retrieve_specialization (t, full_args, hash);
if (spec != NULL_TREE)
{
if (TYPE_P (spec))
/* Type partial instantiations are stored as the type by
lookup_template_class_1, not here as the template. */
spec = CLASSTYPE_TI_TEMPLATE (spec);
return spec;
}
}
/* Make a new template decl. It will be similar to the
original, but will record the current template arguments.
We also create a new function declaration, which is just
like the old one, but points to this new template, rather
than the old one. */
r = copy_decl (t);
gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
DECL_CHAIN (r) = NULL_TREE;
// Build new template info linking to the original template decl.
if (!lambda_fntype)
{
DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
SET_DECL_IMPLICIT_INSTANTIATION (r);
}
else
DECL_TEMPLATE_INFO (r) = NULL_TREE;
/* The template parameters for this new template are all the
template parameters for the old template, except the
outermost level of parameters. */
DECL_TEMPLATE_PARMS (r)
= tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
complain);
if (TREE_CODE (decl) == TYPE_DECL
&& !TYPE_DECL_ALIAS_P (decl))
{
tree new_type;
++processing_template_decl;
new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
--processing_template_decl;
if (new_type == error_mark_node)
return error_mark_node;
TREE_TYPE (r) = new_type;
/* For a partial specialization, we need to keep pointing to
the primary template. */
if (!DECL_TEMPLATE_SPECIALIZATION (t))
CLASSTYPE_TI_TEMPLATE (new_type) = r;
DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
}
else
{
tree new_decl;
++processing_template_decl;
if (TREE_CODE (decl) == FUNCTION_DECL)
new_decl = tsubst_function_decl (decl, args, complain, lambda_fntype);
else
new_decl = tsubst (decl, args, complain, in_decl);
--processing_template_decl;
if (new_decl == error_mark_node)
return error_mark_node;
DECL_TEMPLATE_RESULT (r) = new_decl;
TREE_TYPE (r) = TREE_TYPE (new_decl);
DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
if (lambda_fntype)
{
tree args = template_parms_to_args (DECL_TEMPLATE_PARMS (r));
DECL_TEMPLATE_INFO (new_decl) = build_template_info (r, args);
}
else
{
DECL_TI_TEMPLATE (new_decl) = r;
DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
}
}
DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
if (PRIMARY_TEMPLATE_P (t))
DECL_PRIMARY_TEMPLATE (r) = r;
if (TREE_CODE (decl) != TYPE_DECL && !VAR_P (decl)
&& !lambda_fntype)
/* Record this non-type partial instantiation. */
register_specialization (r, t,
DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
false, hash);
return r;
}
/* True if FN is the op() for a lambda in an uninstantiated template. */
bool
lambda_fn_in_template_p (tree fn)
{
if (!fn || !LAMBDA_FUNCTION_P (fn))
return false;
tree closure = DECL_CONTEXT (fn);
return CLASSTYPE_TEMPLATE_INFO (closure) != NULL_TREE;
}
/* True if FN is the substitution (via tsubst_lambda_expr) of a function for
which the above is true. */
bool
instantiated_lambda_fn_p (tree fn)
{
if (!fn || !LAMBDA_FUNCTION_P (fn))
return false;
tree closure = DECL_CONTEXT (fn);
tree lam = CLASSTYPE_LAMBDA_EXPR (closure);
return LAMBDA_EXPR_INSTANTIATED (lam);
}
/* We're instantiating a variable from template function TCTX. Return the
corresponding current enclosing scope. This gets complicated because lambda
functions in templates are regenerated rather than instantiated, but generic
lambda functions are subsequently instantiated. */
static tree
enclosing_instantiation_of (tree otctx)
{
tree tctx = otctx;
tree fn = current_function_decl;
int lambda_count = 0;
for (; tctx && (lambda_fn_in_template_p (tctx)
|| instantiated_lambda_fn_p (tctx));
tctx = decl_function_context (tctx))
++lambda_count;
if (!tctx)
{
/* Match using DECL_SOURCE_LOCATION, which is unique for all lambdas.
For GCC 11 the above condition limits this to the previously failing
case where all enclosing functions are lambdas (95870). FIXME. */
for (tree ofn = fn; ofn; ofn = decl_function_context (ofn))
if (DECL_SOURCE_LOCATION (ofn) == DECL_SOURCE_LOCATION (otctx))
return ofn;
gcc_unreachable ();
}
for (; fn; fn = decl_function_context (fn))
{
tree ofn = fn;
int flambda_count = 0;
for (; fn && instantiated_lambda_fn_p (fn);
fn = decl_function_context (fn))
++flambda_count;
if ((fn && DECL_TEMPLATE_INFO (fn))
? most_general_template (fn) != most_general_template (tctx)
: fn != tctx)
continue;
if (flambda_count != lambda_count)
{
gcc_assert (flambda_count > lambda_count);
for (; flambda_count > lambda_count; --flambda_count)
ofn = decl_function_context (ofn);
}
gcc_assert (DECL_NAME (ofn) == DECL_NAME (otctx)
|| DECL_CONV_FN_P (ofn));
return ofn;
}
gcc_unreachable ();
}
/* Substitute the ARGS into the T, which is a _DECL. Return the
result of the substitution. Issue error and warning messages under
control of COMPLAIN. */
static tree
tsubst_decl (tree t, tree args, tsubst_flags_t complain)
{
#define RETURN(EXP) do { r = (EXP); goto out; } while(0)
location_t saved_loc;
tree r = NULL_TREE;
tree in_decl = t;
hashval_t hash = 0;
/* Set the filename and linenumber to improve error-reporting. */
saved_loc = input_location;
input_location = DECL_SOURCE_LOCATION (t);
switch (TREE_CODE (t))
{
case TEMPLATE_DECL:
r = tsubst_template_decl (t, args, complain, /*lambda*/NULL_TREE);
break;
case FUNCTION_DECL:
r = tsubst_function_decl (t, args, complain, /*lambda*/NULL_TREE);
break;
case PARM_DECL:
{
tree type = NULL_TREE;
int i, len = 1;
tree expanded_types = NULL_TREE;
tree prev_r = NULL_TREE;
tree first_r = NULL_TREE;
if (DECL_PACK_P (t))
{
/* If there is a local specialization that isn't a
parameter pack, it means that we're doing a "simple"
substitution from inside tsubst_pack_expansion. Just
return the local specialization (which will be a single
parm). */
tree spec = retrieve_local_specialization (t);
if (spec
&& TREE_CODE (spec) == PARM_DECL
&& TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
RETURN (spec);
/* Expand the TYPE_PACK_EXPANSION that provides the types for
the parameters in this function parameter pack. */
expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
complain, in_decl);
if (TREE_CODE (expanded_types) == TREE_VEC)
{
len = TREE_VEC_LENGTH (expanded_types);
/* Zero-length parameter packs are boring. Just substitute
into the chain. */
if (len == 0 && !cp_unevaluated_operand)
RETURN (tsubst (TREE_CHAIN (t), args, complain,
TREE_CHAIN (t)));
}
else
{
/* All we did was update the type. Make a note of that. */
type = expanded_types;
expanded_types = NULL_TREE;
}
}
/* Loop through all of the parameters we'll build. When T is
a function parameter pack, LEN is the number of expanded
types in EXPANDED_TYPES; otherwise, LEN is 1. */
r = NULL_TREE;
for (i = 0; i < len; ++i)
{
prev_r = r;
r = copy_node (t);
if (DECL_TEMPLATE_PARM_P (t))
SET_DECL_TEMPLATE_PARM_P (r);
if (expanded_types)
/* We're on the Ith parameter of the function parameter
pack. */
{
/* Get the Ith type. */
type = TREE_VEC_ELT (expanded_types, i);
/* Rename the parameter to include the index. */
DECL_NAME (r)
= make_ith_pack_parameter_name (DECL_NAME (r), i);
}
else if (!type)
/* We're dealing with a normal parameter. */
type = tsubst (TREE_TYPE (t), args, complain, in_decl);
type = type_decays_to (type);
TREE_TYPE (r) = type;
cp_apply_type_quals_to_decl (cp_type_quals (type), r);
if (DECL_INITIAL (r))
{
if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
DECL_INITIAL (r) = TREE_TYPE (r);
else
DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
complain, in_decl);
}
DECL_CONTEXT (r) = NULL_TREE;
if (!DECL_TEMPLATE_PARM_P (r))
DECL_ARG_TYPE (r) = type_passed_as (type);
apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
args, complain, in_decl);
/* Keep track of the first new parameter we
generate. That's what will be returned to the
caller. */
if (!first_r)
first_r = r;
/* Build a proper chain of parameters when substituting
into a function parameter pack. */
if (prev_r)
DECL_CHAIN (prev_r) = r;
}
/* If cp_unevaluated_operand is set, we're just looking for a
single dummy parameter, so don't keep going. */
if (DECL_CHAIN (t) && !cp_unevaluated_operand)
DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
complain, DECL_CHAIN (t));
/* FIRST_R contains the start of the chain we've built. */
r = first_r;
}
break;
case FIELD_DECL:
{
tree type = NULL_TREE;
tree vec = NULL_TREE;
tree expanded_types = NULL_TREE;
int len = 1;
if (PACK_EXPANSION_P (TREE_TYPE (t)))
{
/* This field is a lambda capture pack. Return a TREE_VEC of
the expanded fields to instantiate_class_template_1. */
expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
complain, in_decl);
if (TREE_CODE (expanded_types) == TREE_VEC)
{
len = TREE_VEC_LENGTH (expanded_types);
vec = make_tree_vec (len);
}
else
{
/* All we did was update the type. Make a note of that. */
type = expanded_types;
expanded_types = NULL_TREE;
}
}
for (int i = 0; i < len; ++i)
{
r = copy_decl (t);
if (expanded_types)
{
type = TREE_VEC_ELT (expanded_types, i);
DECL_NAME (r)
= make_ith_pack_parameter_name (DECL_NAME (r), i);
}
else if (!type)
type = tsubst (TREE_TYPE (t), args, complain, in_decl);
if (type == error_mark_node)
RETURN (error_mark_node);
TREE_TYPE (r) = type;
cp_apply_type_quals_to_decl (cp_type_quals (type), r);
if (DECL_C_BIT_FIELD (r))
/* For bit-fields, DECL_BIT_FIELD_REPRESENTATIVE gives the
number of bits. */
DECL_BIT_FIELD_REPRESENTATIVE (r)
= tsubst_expr (DECL_BIT_FIELD_REPRESENTATIVE (t), args,
complain, in_decl,
/*integral_constant_expression_p=*/true);
if (DECL_INITIAL (t))
{
/* Set up DECL_TEMPLATE_INFO so that we can get at the
NSDMI in perform_member_init. Still set DECL_INITIAL
so that we know there is one. */
DECL_INITIAL (r) = void_node;
gcc_assert (DECL_LANG_SPECIFIC (r) == NULL);
retrofit_lang_decl (r);
DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
}
/* We don't have to set DECL_CONTEXT here; it is set by
finish_member_declaration. */
DECL_CHAIN (r) = NULL_TREE;
apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
args, complain, in_decl);
if (vec)
TREE_VEC_ELT (vec, i) = r;
}
if (vec)
r = vec;
}
break;
case USING_DECL:
/* We reach here only for member using decls. We also need to check
uses_template_parms because DECL_DEPENDENT_P is not set for a
using-declaration that designates a member of the current
instantiation (c++/53549). */
if (DECL_DEPENDENT_P (t)
|| uses_template_parms (USING_DECL_SCOPE (t)))
{
tree scope = USING_DECL_SCOPE (t);
tree name = tsubst_copy (DECL_NAME (t), args, complain, in_decl);
if (PACK_EXPANSION_P (scope))
{
tree vec = tsubst_pack_expansion (scope, args, complain, in_decl);
int len = TREE_VEC_LENGTH (vec);
r = make_tree_vec (len);
for (int i = 0; i < len; ++i)
{
tree escope = TREE_VEC_ELT (vec, i);
tree elt = do_class_using_decl (escope, name);
if (!elt)
{
r = error_mark_node;
break;
}
else
{
TREE_PROTECTED (elt) = TREE_PROTECTED (t);
TREE_PRIVATE (elt) = TREE_PRIVATE (t);
}
TREE_VEC_ELT (r, i) = elt;
}
}
else
{
tree inst_scope = tsubst_copy (USING_DECL_SCOPE (t), args,
complain, in_decl);
r = do_class_using_decl (inst_scope, name);
if (!r)
r = error_mark_node;
else
{
TREE_PROTECTED (r) = TREE_PROTECTED (t);
TREE_PRIVATE (r) = TREE_PRIVATE (t);
}
}
}
else
{
r = copy_node (t);
DECL_CHAIN (r) = NULL_TREE;
}
break;
case TYPE_DECL:
case VAR_DECL:
{
tree argvec = NULL_TREE;
tree gen_tmpl = NULL_TREE;
tree spec;
tree tmpl = NULL_TREE;
tree ctx;
tree type = NULL_TREE;
bool local_p;
if (TREE_TYPE (t) == error_mark_node)
RETURN (error_mark_node);
if (TREE_CODE (t) == TYPE_DECL
&& t == TYPE_MAIN_DECL (TREE_TYPE (t)))
{
/* If this is the canonical decl, we don't have to
mess with instantiations, and often we can't (for
typename, template type parms and such). Note that
TYPE_NAME is not correct for the above test if
we've copied the type for a typedef. */
type = tsubst (TREE_TYPE (t), args, complain, in_decl);
if (type == error_mark_node)
RETURN (error_mark_node);
r = TYPE_NAME (type);
break;
}
/* Check to see if we already have the specialization we
need. */
spec = NULL_TREE;
if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
{
/* T is a static data member or namespace-scope entity.
We have to substitute into namespace-scope variables
(not just variable templates) because of cases like:
template <class T> void f() { extern T t; }
where the entity referenced is not known until
instantiation time. */
local_p = false;
ctx = DECL_CONTEXT (t);
if (DECL_CLASS_SCOPE_P (t))
{
ctx = tsubst_aggr_type (ctx, args,
complain,
in_decl, /*entering_scope=*/1);
/* If CTX is unchanged, then T is in fact the
specialization we want. That situation occurs when
referencing a static data member within in its own
class. We can use pointer equality, rather than
same_type_p, because DECL_CONTEXT is always
canonical... */
if (ctx == DECL_CONTEXT (t)
/* ... unless T is a member template; in which
case our caller can be willing to create a
specialization of that template represented
by T. */
&& !(DECL_TI_TEMPLATE (t)
&& DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t))))
spec = t;
}
if (!spec)
{
tmpl = DECL_TI_TEMPLATE (t);
gen_tmpl = most_general_template (tmpl);
argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
if (argvec != error_mark_node)
argvec = (coerce_innermost_template_parms
(DECL_TEMPLATE_PARMS (gen_tmpl),
argvec, t, complain,
/*all*/true, /*defarg*/true));
if (argvec == error_mark_node)
RETURN (error_mark_node);
hash = hash_tmpl_and_args (gen_tmpl, argvec);
spec = retrieve_specialization (gen_tmpl, argvec, hash);
}
}
else
{
/* A local variable. */
local_p = true;
/* Subsequent calls to pushdecl will fill this in. */
ctx = NULL_TREE;
/* Unless this is a reference to a static variable from an
enclosing function, in which case we need to fill it in now. */
if (TREE_STATIC (t))
{
tree fn = enclosing_instantiation_of (DECL_CONTEXT (t));
if (fn != current_function_decl)
ctx = fn;
}
spec = retrieve_local_specialization (t);
}
/* If we already have the specialization we need, there is
nothing more to do. */
if (spec)
{
r = spec;
break;
}
/* Create a new node for the specialization we need. */
if (type == NULL_TREE)
{
if (is_typedef_decl (t))
type = DECL_ORIGINAL_TYPE (t);
else
type = TREE_TYPE (t);
if (VAR_P (t)
&& VAR_HAD_UNKNOWN_BOUND (t)
&& type != error_mark_node)
type = strip_array_domain (type);
tree sub_args = args;
if (tree auto_node = type_uses_auto (type))
{
/* Mask off any template args past the variable's context so we
don't replace the auto with an unrelated argument. */
int nouter = TEMPLATE_TYPE_LEVEL (auto_node) - 1;
int extra = TMPL_ARGS_DEPTH (args) - nouter;
if (extra > 0)
/* This should never happen with the new lambda instantiation
model, but keep the handling just in case. */
gcc_assert (!CHECKING_P),
sub_args = strip_innermost_template_args (args, extra);
}
type = tsubst (type, sub_args, complain, in_decl);
/* Substituting the type might have recursively instantiated this
same alias (c++/86171). */
if (gen_tmpl && DECL_ALIAS_TEMPLATE_P (gen_tmpl)
&& (spec = retrieve_specialization (gen_tmpl, argvec, hash)))
{
r = spec;
break;
}
}
r = copy_decl (t);
if (VAR_P (r))
{
DECL_INITIALIZED_P (r) = 0;
DECL_TEMPLATE_INSTANTIATED (r) = 0;
if (type == error_mark_node)
RETURN (error_mark_node);
if (TREE_CODE (type) == FUNCTION_TYPE)
{
/* It may seem that this case cannot occur, since:
typedef void f();
void g() { f x; }
declares a function, not a variable. However:
typedef void f();
template <typename T> void g() { T t; }
template void g<f>();
is an attempt to declare a variable with function
type. */
error ("variable %qD has function type",
/* R is not yet sufficiently initialized, so we
just use its name. */
DECL_NAME (r));
RETURN (error_mark_node);
}
type = complete_type (type);
/* Wait until cp_finish_decl to set this again, to handle
circular dependency (template/instantiate6.C). */
DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
type = check_var_type (DECL_NAME (r), type);
if (DECL_HAS_VALUE_EXPR_P (t))
{
tree ve = DECL_VALUE_EXPR (t);
/* If the DECL_VALUE_EXPR is converted to the declared type,
preserve the identity so that gimplify_type_sizes works. */
bool nop = (TREE_CODE (ve) == NOP_EXPR);
if (nop)
ve = TREE_OPERAND (ve, 0);
ve = tsubst_expr (ve, args, complain, in_decl,
/*constant_expression_p=*/false);
if (REFERENCE_REF_P (ve))
{
gcc_assert (TYPE_REF_P (type));
ve = TREE_OPERAND (ve, 0);
}
if (nop)
ve = build_nop (type, ve);
else
gcc_checking_assert (TREE_TYPE (ve) == type);
SET_DECL_VALUE_EXPR (r, ve);
}
if (CP_DECL_THREAD_LOCAL_P (r)
&& !processing_template_decl)
set_decl_tls_model (r, decl_default_tls_model (r));
}
else if (DECL_SELF_REFERENCE_P (t))
SET_DECL_SELF_REFERENCE_P (r);
TREE_TYPE (r) = type;
cp_apply_type_quals_to_decl (cp_type_quals (type), r);
DECL_CONTEXT (r) = ctx;
/* Clear out the mangled name and RTL for the instantiation. */
SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
SET_DECL_RTL (r, NULL);
/* The initializer must not be expanded until it is required;
see [temp.inst]. */
DECL_INITIAL (r) = NULL_TREE;
DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
if (VAR_P (r))
{
if (DECL_LANG_SPECIFIC (r))
SET_DECL_DEPENDENT_INIT_P (r, false);
SET_DECL_MODE (r, VOIDmode);
/* Possibly limit visibility based on template args. */
DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
if (DECL_VISIBILITY_SPECIFIED (t))
{
DECL_VISIBILITY_SPECIFIED (r) = 0;
DECL_ATTRIBUTES (r)
= remove_attribute ("visibility", DECL_ATTRIBUTES (r));
}
determine_visibility (r);
}
if (!local_p)
{
/* A static data member declaration is always marked
external when it is declared in-class, even if an
initializer is present. We mimic the non-template
processing here. */
DECL_EXTERNAL (r) = 1;
if (DECL_NAMESPACE_SCOPE_P (t))
DECL_NOT_REALLY_EXTERN (r) = 1;
DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
SET_DECL_IMPLICIT_INSTANTIATION (r);
if (!error_operand_p (r) || (complain & tf_error))
register_specialization (r, gen_tmpl, argvec, false, hash);
}
else
{
if (DECL_LANG_SPECIFIC (r))
DECL_TEMPLATE_INFO (r) = NULL_TREE;
if (!cp_unevaluated_operand)
register_local_specialization (r, t);
}
DECL_CHAIN (r) = NULL_TREE;
apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
/*flags=*/0,
args, complain, in_decl);
/* Preserve a typedef that names a type. */
if (is_typedef_decl (r) && type != error_mark_node)
{
DECL_ORIGINAL_TYPE (r) = NULL_TREE;
set_underlying_type (r);
/* common_handle_aligned_attribute doesn't apply the alignment
to DECL_ORIGINAL_TYPE. */
if (TYPE_USER_ALIGN (TREE_TYPE (t)))
TREE_TYPE (r) = build_aligned_type (TREE_TYPE (r),
TYPE_ALIGN (TREE_TYPE (t)));
if (TYPE_DECL_ALIAS_P (r))
/* An alias template specialization can be dependent
even if its underlying type is not. */
TYPE_DEPENDENT_P_VALID (TREE_TYPE (r)) = false;
}
layout_decl (r, 0);
}
break;
default:
gcc_unreachable ();
}
#undef RETURN
out:
/* Restore the file and line information. */
input_location = saved_loc;
return r;
}
/* Substitute into the ARG_TYPES of a function type.
If END is a TREE_CHAIN, leave it and any following types
un-substituted. */
static tree
tsubst_arg_types (tree arg_types,
tree args,
tree end,
tsubst_flags_t complain,
tree in_decl)
{
tree remaining_arg_types;
tree type = NULL_TREE;
int i = 1;
tree expanded_args = NULL_TREE;
tree default_arg;
if (!arg_types || arg_types == void_list_node || arg_types == end)
return arg_types;
remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
args, end, complain, in_decl);
if (remaining_arg_types == error_mark_node)
return error_mark_node;
if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
{
/* For a pack expansion, perform substitution on the
entire expression. Later on, we'll handle the arguments
one-by-one. */
expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
args, complain, in_decl);
if (TREE_CODE (expanded_args) == TREE_VEC)
/* So that we'll spin through the parameters, one by one. */
i = TREE_VEC_LENGTH (expanded_args);
else
{
/* We only partially substituted into the parameter
pack. Our type is TYPE_PACK_EXPANSION. */
type = expanded_args;
expanded_args = NULL_TREE;
}
}
while (i > 0) {
--i;
if (expanded_args)
type = TREE_VEC_ELT (expanded_args, i);
else if (!type)
type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
if (type == error_mark_node)
return error_mark_node;
if (VOID_TYPE_P (type))
{
if (complain & tf_error)
{
error ("invalid parameter type %qT", type);
if (in_decl)
error ("in declaration %q+D", in_decl);
}
return error_mark_node;
}
/* DR 657. */
if (abstract_virtuals_error_sfinae (ACU_PARM, type, complain))
return error_mark_node;
/* Do array-to-pointer, function-to-pointer conversion, and ignore
top-level qualifiers as required. */
type = cv_unqualified (type_decays_to (type));
/* We do not substitute into default arguments here. The standard
mandates that they be instantiated only when needed, which is
done in build_over_call. */
default_arg = TREE_PURPOSE (arg_types);
/* Except that we do substitute default arguments under tsubst_lambda_expr,
since the new op() won't have any associated template arguments for us
to refer to later. */
if (lambda_fn_in_template_p (in_decl))
default_arg = tsubst_copy_and_build (default_arg, args, complain, in_decl,
false/*fn*/, false/*constexpr*/);
if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
{
/* We've instantiated a template before its default arguments
have been parsed. This can happen for a nested template
class, and is not an error unless we require the default
argument in a call of this function. */
remaining_arg_types =
tree_cons (default_arg, type, remaining_arg_types);
vec_safe_push (DEFARG_INSTANTIATIONS(default_arg), remaining_arg_types);
}
else
remaining_arg_types =
hash_tree_cons (default_arg, type, remaining_arg_types);
}
return remaining_arg_types;
}
/* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
*not* handle the exception-specification for FNTYPE, because the
initial substitution of explicitly provided template parameters
during argument deduction forbids substitution into the
exception-specification:
[temp.deduct]
All references in the function type of the function template to the
corresponding template parameters are replaced by the specified tem-
plate argument values. If a substitution in a template parameter or
in the function type of the function template results in an invalid
type, type deduction fails. [Note: The equivalent substitution in
exception specifications is done only when the function is instanti-
ated, at which point a program is ill-formed if the substitution
results in an invalid type.] */
static tree
tsubst_function_type (tree t,
tree args,
tsubst_flags_t complain,
tree in_decl)
{
tree return_type;
tree arg_types = NULL_TREE;
tree fntype;
/* The TYPE_CONTEXT is not used for function/method types. */
gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
/* DR 1227: Mixing immediate and non-immediate contexts in deduction
failure. */
bool late_return_type_p = TYPE_HAS_LATE_RETURN_TYPE (t);
if (late_return_type_p)
{
/* Substitute the argument types. */
arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args, NULL_TREE,
complain, in_decl);
if (arg_types == error_mark_node)
return error_mark_node;
tree save_ccp = current_class_ptr;
tree save_ccr = current_class_ref;
tree this_type = (TREE_CODE (t) == METHOD_TYPE
? TREE_TYPE (TREE_VALUE (arg_types)) : NULL_TREE);
bool do_inject = this_type && CLASS_TYPE_P (this_type);
if (do_inject)
{
/* DR 1207: 'this' is in scope in the trailing return type. */
inject_this_parameter (this_type, cp_type_quals (this_type));
}
/* Substitute the return type. */
return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
if (do_inject)
{
current_class_ptr = save_ccp;
current_class_ref = save_ccr;
}
}
else
/* Substitute the return type. */
return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
if (return_type == error_mark_node)
return error_mark_node;
/* DR 486 clarifies that creation of a function type with an
invalid return type is a deduction failure. */
if (TREE_CODE (return_type) == ARRAY_TYPE
|| TREE_CODE (return_type) == FUNCTION_TYPE)
{
if (complain & tf_error)
{
if (TREE_CODE (return_type) == ARRAY_TYPE)
error ("function returning an array");
else
error ("function returning a function");
}
return error_mark_node;
}
/* And DR 657. */
if (abstract_virtuals_error_sfinae (ACU_RETURN, return_type, complain))
return error_mark_node;
if (!late_return_type_p)
{
/* Substitute the argument types. */
arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args, NULL_TREE,
complain, in_decl);
if (arg_types == error_mark_node)
return error_mark_node;
}
/* Construct a new type node and return it. */
if (TREE_CODE (t) == FUNCTION_TYPE)
{
fntype = build_function_type (return_type, arg_types);
fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
}
else
{
tree r = TREE_TYPE (TREE_VALUE (arg_types));
/* Don't pick up extra function qualifiers from the basetype. */
r = cp_build_qualified_type_real (r, type_memfn_quals (t), complain);
if (! MAYBE_CLASS_TYPE_P (r))
{
/* [temp.deduct]
Type deduction may fail for any of the following
reasons:
-- Attempting to create "pointer to member of T" when T
is not a class type. */
if (complain & tf_error)
error ("creating pointer to member function of non-class type %qT",
r);
return error_mark_node;
}
fntype = build_method_type_directly (r, return_type,
TREE_CHAIN (arg_types));
}
fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
/* See comment above. */
tree raises = NULL_TREE;
cp_ref_qualifier rqual = type_memfn_rqual (t);
fntype = build_cp_fntype_variant (fntype, rqual, raises, late_return_type_p);
return fntype;
}
/* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
ARGS into that specification, and return the substituted
specification. If there is no specification, return NULL_TREE. */
static tree
tsubst_exception_specification (tree fntype,
tree args,
tsubst_flags_t complain,
tree in_decl,
bool defer_ok)
{
tree specs;
tree new_specs;
specs = TYPE_RAISES_EXCEPTIONS (fntype);
new_specs = NULL_TREE;
if (specs && TREE_PURPOSE (specs))
{
/* A noexcept-specifier. */
tree expr = TREE_PURPOSE (specs);
if (TREE_CODE (expr) == INTEGER_CST)
new_specs = expr;
else if (defer_ok)
{
/* Defer instantiation of noexcept-specifiers to avoid
excessive instantiations (c++/49107). */
new_specs = make_node (DEFERRED_NOEXCEPT);
if (DEFERRED_NOEXCEPT_SPEC_P (specs))
{
/* We already partially instantiated this member template,
so combine the new args with the old. */
DEFERRED_NOEXCEPT_PATTERN (new_specs)
= DEFERRED_NOEXCEPT_PATTERN (expr);
DEFERRED_NOEXCEPT_ARGS (new_specs)
= add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
}
else
{
DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
}
}
else
{
if (DEFERRED_NOEXCEPT_SPEC_P (specs))
{
args = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr),
args);
expr = DEFERRED_NOEXCEPT_PATTERN (expr);
}
new_specs = tsubst_copy_and_build
(expr, args, complain, in_decl, /*function_p=*/false,
/*integral_constant_expression_p=*/true);
}
new_specs = build_noexcept_spec (new_specs, complain);
}
else if (specs)
{
if (! TREE_VALUE (specs))
new_specs = specs;
else
while (specs)
{
tree spec;
int i, len = 1;
tree expanded_specs = NULL_TREE;
if (PACK_EXPANSION_P (TREE_VALUE (specs)))
{
/* Expand the pack expansion type. */
expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
args, complain,
in_decl);
if (expanded_specs == error_mark_node)
return error_mark_node;
else if (TREE_CODE (expanded_specs) == TREE_VEC)
len = TREE_VEC_LENGTH (expanded_specs);
else
{
/* We're substituting into a member template, so
we got a TYPE_PACK_EXPANSION back. Add that
expansion and move on. */
gcc_assert (TREE_CODE (expanded_specs)
== TYPE_PACK_EXPANSION);
new_specs = add_exception_specifier (new_specs,
expanded_specs,
complain);
specs = TREE_CHAIN (specs);
continue;
}
}
for (i = 0; i < len; ++i)
{
if (expanded_specs)
spec = TREE_VEC_ELT (expanded_specs, i);
else
spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
if (spec == error_mark_node)
return spec;
new_specs = add_exception_specifier (new_specs, spec,
complain);
}
specs = TREE_CHAIN (specs);
}
}
return new_specs;
}
/* Take the tree structure T and replace template parameters used
therein with the argument vector ARGS. IN_DECL is an associated
decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
Issue error and warning messages under control of COMPLAIN. Note
that we must be relatively non-tolerant of extensions here, in
order to preserve conformance; if we allow substitutions that
should not be allowed, we may allow argument deductions that should
not succeed, and therefore report ambiguous overload situations
where there are none. In theory, we could allow the substitution,
but indicate that it should have failed, and allow our caller to
make sure that the right thing happens, but we don't try to do this
yet.
This function is used for dealing with types, decls and the like;
for expressions, use tsubst_expr or tsubst_copy. */
tree
tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
{
enum tree_code code;
tree type, r = NULL_TREE;
if (t == NULL_TREE || t == error_mark_node
|| t == integer_type_node
|| t == void_type_node
|| t == char_type_node
|| t == unknown_type_node
|| TREE_CODE (t) == NAMESPACE_DECL
|| TREE_CODE (t) == TRANSLATION_UNIT_DECL)
return t;
if (DECL_P (t))
return tsubst_decl (t, args, complain);
if (args == NULL_TREE)
return t;
code = TREE_CODE (t);
if (code == IDENTIFIER_NODE)
type = IDENTIFIER_TYPE_VALUE (t);
else
type = TREE_TYPE (t);
gcc_assert (type != unknown_type_node);
/* Reuse typedefs. We need to do this to handle dependent attributes,
such as attribute aligned. */
if (TYPE_P (t)
&& typedef_variant_p (t))
{
tree decl = TYPE_NAME (t);
if (alias_template_specialization_p (t))
{
/* DECL represents an alias template and we want to
instantiate it. */
tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
r = instantiate_alias_template (tmpl, gen_args, complain);
}
else if (DECL_CLASS_SCOPE_P (decl)
&& CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
&& uses_template_parms (DECL_CONTEXT (decl)))
{
tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
r = retrieve_specialization (tmpl, gen_args, 0);
}
else if (DECL_FUNCTION_SCOPE_P (decl)
&& DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
&& uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
r = retrieve_local_specialization (decl);
else
/* The typedef is from a non-template context. */
return t;
if (r)
{
r = TREE_TYPE (r);
r = cp_build_qualified_type_real
(r, cp_type_quals (t) | cp_type_quals (r),
complain | tf_ignore_bad_quals);
return r;
}
else
{
/* We don't have an instantiation yet, so drop the typedef. */
int quals = cp_type_quals (t);
t = DECL_ORIGINAL_TYPE (decl);
t = cp_build_qualified_type_real (t, quals,
complain | tf_ignore_bad_quals);
}
}
bool fndecl_type = (complain & tf_fndecl_type);
complain &= ~tf_fndecl_type;
if (type
&& code != TYPENAME_TYPE
&& code != TEMPLATE_TYPE_PARM
&& code != TEMPLATE_PARM_INDEX
&& code != IDENTIFIER_NODE
&& code != FUNCTION_TYPE
&& code != METHOD_TYPE)
type = tsubst (type, args, complain, in_decl);
if (type == error_mark_node)
return error_mark_node;
switch (code)
{
case RECORD_TYPE:
case UNION_TYPE:
case ENUMERAL_TYPE:
return tsubst_aggr_type (t, args, complain, in_decl,
/*entering_scope=*/0);
case ERROR_MARK:
case IDENTIFIER_NODE:
case VOID_TYPE:
case REAL_TYPE:
case COMPLEX_TYPE:
case VECTOR_TYPE:
case BOOLEAN_TYPE:
case NULLPTR_TYPE:
case LANG_TYPE:
return t;
case INTEGER_TYPE:
if (t == integer_type_node)
return t;
if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
&& TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
return t;
{
tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
max = tsubst_expr (omax, args, complain, in_decl,
/*integral_constant_expression_p=*/false);
/* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
needed. */
if (TREE_CODE (max) == NOP_EXPR
&& TREE_SIDE_EFFECTS (omax)
&& !TREE_TYPE (max))
TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
/* If we're in a partial instantiation, preserve the magic NOP_EXPR
with TREE_SIDE_EFFECTS that indicates this is not an integral
constant expression. */
if (processing_template_decl
&& TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
{
gcc_assert (TREE_CODE (max) == NOP_EXPR);
TREE_SIDE_EFFECTS (max) = 1;
}
return compute_array_index_type (NULL_TREE, max, complain);
}
case TEMPLATE_TYPE_PARM:
case TEMPLATE_TEMPLATE_PARM:
case BOUND_TEMPLATE_TEMPLATE_PARM:
case TEMPLATE_PARM_INDEX:
{
int idx;
int level;
int levels;
tree arg = NULL_TREE;
/* Early in template argument deduction substitution, we don't
want to reduce the level of 'auto', or it will be confused
with a normal template parm in subsequent deduction. */
if (is_auto (t) && (complain & tf_partial))
return t;
r = NULL_TREE;
gcc_assert (TREE_VEC_LENGTH (args) > 0);
template_parm_level_and_index (t, &level, &idx);
levels = TMPL_ARGS_DEPTH (args);
if (level <= levels
&& TREE_VEC_LENGTH (TMPL_ARGS_LEVEL (args, level)) > 0)
{
arg = TMPL_ARG (args, level, idx);
/* See through ARGUMENT_PACK_SELECT arguments. */
if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
arg = argument_pack_select_arg (arg);
}
if (arg == error_mark_node)
return error_mark_node;
else if (arg != NULL_TREE)
{
if (ARGUMENT_PACK_P (arg))
/* If ARG is an argument pack, we don't actually want to
perform a substitution here, because substitutions
for argument packs are only done
element-by-element. We can get to this point when
substituting the type of a non-type template
parameter pack, when that type actually contains
template parameter packs from an outer template, e.g.,
template<typename... Types> struct A {
template<Types... Values> struct B { };
}; */
return t;
if (code == TEMPLATE_TYPE_PARM)
{
int quals;
gcc_assert (TYPE_P (arg));
quals = cp_type_quals (arg) | cp_type_quals (t);
return cp_build_qualified_type_real
(arg, quals, complain | tf_ignore_bad_quals);
}
else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
{
/* We are processing a type constructed from a
template template parameter. */
tree argvec = tsubst (TYPE_TI_ARGS (t),
args, complain, in_decl);
if (argvec == error_mark_node)
return error_mark_node;
gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
|| TREE_CODE (arg) == TEMPLATE_DECL
|| TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)
/* Consider this code:
template <template <class> class Template>
struct Internal {
template <class Arg> using Bind = Template<Arg>;
};
template <template <class> class Template, class Arg>
using Instantiate = Template<Arg>; //#0
template <template <class> class Template,
class Argument>
using Bind =
Instantiate<Internal<Template>::template Bind,
Argument>; //#1
When #1 is parsed, the
BOUND_TEMPLATE_TEMPLATE_PARM representing the
parameter `Template' in #0 matches the
UNBOUND_CLASS_TEMPLATE representing the argument
`Internal<Template>::template Bind'; We then want
to assemble the type `Bind<Argument>' that can't
be fully created right now, because
`Internal<Template>' not being complete, the Bind
template cannot be looked up in that context. So
we need to "store" `Bind<Argument>' for later
when the context of Bind becomes complete. Let's
store that in a TYPENAME_TYPE. */
return make_typename_type (TYPE_CONTEXT (arg),
build_nt (TEMPLATE_ID_EXPR,
TYPE_IDENTIFIER (arg),
argvec),
typename_type,
complain);
/* We can get a TEMPLATE_TEMPLATE_PARM here when we
are resolving nested-types in the signature of a
member function templates. Otherwise ARG is a
TEMPLATE_DECL and is the real template to be
instantiated. */
if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
arg = TYPE_NAME (arg);
r = lookup_template_class (arg,
argvec, in_decl,
DECL_CONTEXT (arg),
/*entering_scope=*/0,
complain);
return cp_build_qualified_type_real
(r, cp_type_quals (t) | cp_type_quals (r), complain);
}
else if (code == TEMPLATE_TEMPLATE_PARM)
return arg;
else
/* TEMPLATE_PARM_INDEX. */
return convert_from_reference (unshare_expr (arg));
}
if (level == 1)
/* This can happen during the attempted tsubst'ing in
unify. This means that we don't yet have any information
about the template parameter in question. */
return t;
/* Like with 'auto', don't reduce the level of template parameters
to avoid mismatches when deducing their types. */
if (complain & tf_partial)
return t;
/* If we get here, we must have been looking at a parm for a
more deeply nested template. Make a new version of this
template parameter, but with a lower level. */
switch (code)
{
case TEMPLATE_TYPE_PARM:
case TEMPLATE_TEMPLATE_PARM:
case BOUND_TEMPLATE_TEMPLATE_PARM:
if (cp_type_quals (t))
{
r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
r = cp_build_qualified_type_real
(r, cp_type_quals (t),
complain | (code == TEMPLATE_TYPE_PARM
? tf_ignore_bad_quals : 0));
}
else if (TREE_CODE (t) == TEMPLATE_TYPE_PARM
&& PLACEHOLDER_TYPE_CONSTRAINTS (t)
&& (r = (TEMPLATE_PARM_DESCENDANTS
(TEMPLATE_TYPE_PARM_INDEX (t))))
&& (r = TREE_TYPE (r))
&& !PLACEHOLDER_TYPE_CONSTRAINTS (r))
/* Break infinite recursion when substituting the constraints
of a constrained placeholder. */;
else if (TREE_CODE (t) == TEMPLATE_TYPE_PARM
&& !PLACEHOLDER_TYPE_CONSTRAINTS (t)
&& !CLASS_PLACEHOLDER_TEMPLATE (t)
&& (arg = TEMPLATE_TYPE_PARM_INDEX (t),
r = TEMPLATE_PARM_DESCENDANTS (arg))
&& (TEMPLATE_PARM_LEVEL (r)
== TEMPLATE_PARM_LEVEL (arg) - levels))
/* Cache the simple case of lowering a type parameter. */
r = TREE_TYPE (r);
else
{
r = copy_type (t);
TEMPLATE_TYPE_PARM_INDEX (r)
= reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
r, levels, args, complain);
TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
TYPE_MAIN_VARIANT (r) = r;
TYPE_POINTER_TO (r) = NULL_TREE;
TYPE_REFERENCE_TO (r) = NULL_TREE;
if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
{
/* Propagate constraints on placeholders. */
if (tree constr = PLACEHOLDER_TYPE_CONSTRAINTS (t))
PLACEHOLDER_TYPE_CONSTRAINTS (r)
= tsubst_constraint (constr, args, complain, in_decl);
else if (tree pl = CLASS_PLACEHOLDER_TEMPLATE (t))
{
pl = tsubst_copy (pl, args, complain, in_decl);
CLASS_PLACEHOLDER_TEMPLATE (r) = pl;
}
}
if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
/* We have reduced the level of the template
template parameter, but not the levels of its
template parameters, so canonical_type_parameter
will not be able to find the canonical template
template parameter for this level. Thus, we
require structural equality checking to compare
TEMPLATE_TEMPLATE_PARMs. */
SET_TYPE_STRUCTURAL_EQUALITY (r);
else if (TYPE_STRUCTURAL_EQUALITY_P (t))
SET_TYPE_STRUCTURAL_EQUALITY (r);
else
TYPE_CANONICAL (r) = canonical_type_parameter (r);
if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
{
tree tinfo = TYPE_TEMPLATE_INFO (t);
/* We might need to substitute into the types of non-type
template parameters. */
tree tmpl = tsubst (TI_TEMPLATE (tinfo), args,
complain, in_decl);
if (tmpl == error_mark_node)
return error_mark_node;
tree argvec = tsubst (TI_ARGS (tinfo), args,
complain, in_decl);
if (argvec == error_mark_node)
return error_mark_node;
TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
= build_template_info (tmpl, argvec);
}
}
break;
case TEMPLATE_PARM_INDEX:
/* OK, now substitute the type of the non-type parameter. We
couldn't do it earlier because it might be an auto parameter,
and we wouldn't need to if we had an argument. */
type = tsubst (type, args, complain, in_decl);
if (type == error_mark_node)
return error_mark_node;
r = reduce_template_parm_level (t, type, levels, args, complain);
break;
default:
gcc_unreachable ();
}
return r;
}
case TREE_LIST:
{
tree purpose, value, chain;
if (t == void_list_node)
return t;
if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
|| (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
{
/* We have pack expansions, so expand those and
create a new list out of it. */
/* Expand the argument expressions. */
tree purposevec = NULL_TREE;
if (TREE_PURPOSE (t))
purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
complain, in_decl);
if (purposevec == error_mark_node)
return error_mark_node;
tree valuevec = NULL_TREE;
if (TREE_VALUE (t))
valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
complain, in_decl);
if (valuevec == error_mark_node)
return error_mark_node;
/* Build the rest of the list. */
tree chain = TREE_CHAIN (t);
if (chain && chain != void_type_node)
chain = tsubst (chain, args, complain, in_decl);
if (chain == error_mark_node)
return error_mark_node;
/* Determine the number of arguments. */
int len = -1;
if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
{
len = TREE_VEC_LENGTH (purposevec);
gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
}
else if (TREE_CODE (valuevec) == TREE_VEC)
len = TREE_VEC_LENGTH (valuevec);
else
{
/* Since we only performed a partial substitution into
the argument pack, we only RETURN (a single list
node. */
if (purposevec == TREE_PURPOSE (t)
&& valuevec == TREE_VALUE (t)
&& chain == TREE_CHAIN (t))
return t;
return tree_cons (purposevec, valuevec, chain);
}
/* Convert the argument vectors into a TREE_LIST. */
for (int i = len; i-- > 0; )
{
purpose = (purposevec ? TREE_VEC_ELT (purposevec, i)
: NULL_TREE);
value = (valuevec ? TREE_VEC_ELT (valuevec, i)
: NULL_TREE);
/* Build the list (backwards). */
chain = hash_tree_cons (purpose, value, chain);
}
return chain;
}
purpose = TREE_PURPOSE (t);
if (purpose)
{
purpose = tsubst (purpose, args, complain, in_decl);
if (purpose == error_mark_node)
return error_mark_node;
}
value = TREE_VALUE (t);
if (value)
{
value = tsubst (value, args, complain, in_decl);
if (value == error_mark_node)
return error_mark_node;
}
chain = TREE_CHAIN (t);
if (chain && chain != void_type_node)
{
chain = tsubst (chain, args, complain, in_decl);
if (chain == error_mark_node)
return error_mark_node;
}
if (purpose == TREE_PURPOSE (t)
&& value == TREE_VALUE (t)
&& chain == TREE_CHAIN (t))
return t;
return hash_tree_cons (purpose, value, chain);
}
case TREE_BINFO:
/* We should never be tsubsting a binfo. */
gcc_unreachable ();
case TREE_VEC:
/* A vector of template arguments. */
gcc_assert (!type);
return tsubst_template_args (t, args, complain, in_decl);
case POINTER_TYPE:
case REFERENCE_TYPE:
{
if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
return t;
/* [temp.deduct]
Type deduction may fail for any of the following
reasons:
-- Attempting to create a pointer to reference type.
-- Attempting to create a reference to a reference type or
a reference to void.
Core issue 106 says that creating a reference to a reference
during instantiation is no longer a cause for failure. We
only enforce this check in strict C++98 mode. */
if ((TYPE_REF_P (type)
&& (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
|| (code == REFERENCE_TYPE && VOID_TYPE_P (type)))
{
static location_t last_loc;
/* We keep track of the last time we issued this error
message to avoid spewing a ton of messages during a
single bad template instantiation. */
if (complain & tf_error
&& last_loc != input_location)
{
if (VOID_TYPE_P (type))
error ("forming reference to void");
else if (code == POINTER_TYPE)
error ("forming pointer to reference type %qT", type);
else
error ("forming reference to reference type %qT", type);
last_loc = input_location;
}
return error_mark_node;
}
else if (TREE_CODE (type) == FUNCTION_TYPE
&& (type_memfn_quals (type) != TYPE_UNQUALIFIED
|| type_memfn_rqual (type) != REF_QUAL_NONE))
{
if (complain & tf_error)
{
if (code == POINTER_TYPE)
error ("forming pointer to qualified function type %qT",
type);
else
error ("forming reference to qualified function type %qT",
type);
}
return error_mark_node;
}
else if (code == POINTER_TYPE)
{
r = build_pointer_type (type);
if (TREE_CODE (type) == METHOD_TYPE)
r = build_ptrmemfunc_type (r);
}
else if (TYPE_REF_P (type))
/* In C++0x, during template argument substitution, when there is an
attempt to create a reference to a reference type, reference
collapsing is applied as described in [14.3.1/4 temp.arg.type]:
"If a template-argument for a template-parameter T names a type
that is a reference to a type A, an attempt to create the type
'lvalue reference to cv T' creates the type 'lvalue reference to
A,' while an attempt to create the type type rvalue reference to
cv T' creates the type T"
*/
r = cp_build_reference_type
(TREE_TYPE (type),
TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
else
r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
if (r != error_mark_node)
/* Will this ever be needed for TYPE_..._TO values? */
layout_type (r);
return r;
}
case OFFSET_TYPE:
{
r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
{
/* [temp.deduct]
Type deduction may fail for any of the following
reasons:
-- Attempting to create "pointer to member of T" when T
is not a class type. */
if (complain & tf_error)
error ("creating pointer to member of non-class type %qT", r);
return error_mark_node;
}
if (TYPE_REF_P (type))
{
if (complain & tf_error)
error ("creating pointer to member reference type %qT", type);
return error_mark_node;
}
if (VOID_TYPE_P (type))
{
if (complain & tf_error)
error ("creating pointer to member of type void");
return error_mark_node;
}
gcc_assert (TREE_CODE (type) != METHOD_TYPE);
if (TREE_CODE (type) == FUNCTION_TYPE)
{
/* The type of the implicit object parameter gets its
cv-qualifiers from the FUNCTION_TYPE. */
tree memptr;
tree method_type
= build_memfn_type (type, r, type_memfn_quals (type),
type_memfn_rqual (type));
memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
return cp_build_qualified_type_real (memptr, cp_type_quals (t),
complain);
}
else
return cp_build_qualified_type_real (build_ptrmem_type (r, type),
cp_type_quals (t),
complain);
}
case FUNCTION_TYPE:
case METHOD_TYPE:
{
tree fntype;
tree specs;
fntype = tsubst_function_type (t, args, complain, in_decl);
if (fntype == error_mark_node)
return error_mark_node;
/* Substitute the exception specification. */
specs = tsubst_exception_specification (t, args, complain, in_decl,
/*defer_ok*/fndecl_type);
if (specs == error_mark_node)
return error_mark_node;
if (specs)
fntype = build_exception_variant (fntype, specs);
return fntype;
}
case ARRAY_TYPE:
{
tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
if (domain == error_mark_node)
return error_mark_node;
/* As an optimization, we avoid regenerating the array type if
it will obviously be the same as T. */
if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
return t;
/* These checks should match the ones in create_array_type_for_decl.
[temp.deduct]
The deduction may fail for any of the following reasons:
-- Attempting to create an array with an element type that
is void, a function type, or a reference type, or [DR337]
an abstract class type. */
if (VOID_TYPE_P (type)
|| TREE_CODE (type) == FUNCTION_TYPE
|| (TREE_CODE (type) == ARRAY_TYPE
&& TYPE_DOMAIN (type) == NULL_TREE)
|| TYPE_REF_P (type))
{
if (complain & tf_error)
error ("creating array of %qT", type);
return error_mark_node;
}
if (abstract_virtuals_error_sfinae (ACU_ARRAY, type, complain))
return error_mark_node;
r = build_cplus_array_type (type, domain);
if (!valid_array_size_p (input_location, r, in_decl,
(complain & tf_error)))
return error_mark_node;
if (TYPE_USER_ALIGN (t))
{
SET_TYPE_ALIGN (r, TYPE_ALIGN (t));
TYPE_USER_ALIGN (r) = 1;
}
return r;
}
case TYPENAME_TYPE:
{
tree ctx = TYPE_CONTEXT (t);
if (TREE_CODE (ctx) == TYPE_PACK_EXPANSION)
{
ctx = tsubst_pack_expansion (ctx, args, complain, in_decl);
if (ctx == error_mark_node
|| TREE_VEC_LENGTH (ctx) > 1)
return error_mark_node;
if (TREE_VEC_LENGTH (ctx) == 0)
{
if (complain & tf_error)
error ("%qD is instantiated for an empty pack",
TYPENAME_TYPE_FULLNAME (t));
return error_mark_node;
}
ctx = TREE_VEC_ELT (ctx, 0);
}
else
ctx = tsubst_aggr_type (ctx, args, complain, in_decl,
/*entering_scope=*/1);
if (ctx == error_mark_node)
return error_mark_node;
tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
complain, in_decl);
if (f == error_mark_node)
return error_mark_node;
if (!MAYBE_CLASS_TYPE_P (ctx))
{
if (complain & tf_error)
error ("%qT is not a class, struct, or union type", ctx);
return error_mark_node;
}
else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
{
/* Normally, make_typename_type does not require that the CTX
have complete type in order to allow things like:
template <class T> struct S { typename S<T>::X Y; };
But, such constructs have already been resolved by this
point, so here CTX really should have complete type, unless
it's a partial instantiation. */
ctx = complete_type (ctx);
if (!COMPLETE_TYPE_P (ctx))
{
if (complain & tf_error)
cxx_incomplete_type_error (NULL_TREE, ctx);
return error_mark_node;
}
}
f = make_typename_type (ctx, f, typename_type,
complain | tf_keep_type_decl);
if (f == error_mark_node)
return f;
if (TREE_CODE (f) == TYPE_DECL)
{
complain |= tf_ignore_bad_quals;
f = TREE_TYPE (f);
}
if (TREE_CODE (f) != TYPENAME_TYPE)
{
if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
{
if (complain & tf_error)
error ("%qT resolves to %qT, which is not an enumeration type",
t, f);
else
return error_mark_node;
}
else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
{
if (complain & tf_error)
error ("%qT resolves to %qT, which is is not a class type",
t, f);
else
return error_mark_node;
}
}
return cp_build_qualified_type_real
(f, cp_type_quals (f) | cp_type_quals (t), complain);
}
case UNBOUND_CLASS_TEMPLATE:
{
tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
in_decl, /*entering_scope=*/1);
tree name = TYPE_IDENTIFIER (t);
tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
if (ctx == error_mark_node || name == error_mark_node)
return error_mark_node;
if (parm_list)
parm_list = tsubst_template_parms (parm_list, args, complain);
return make_unbound_class_template (ctx, name, parm_list, complain);
}
case TYPEOF_TYPE:
{
tree type;
++cp_unevaluated_operand;
++c_inhibit_evaluation_warnings;
type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
complain, in_decl,
/*integral_constant_expression_p=*/false);
--cp_unevaluated_operand;
--c_inhibit_evaluation_warnings;
type = finish_typeof (type);
return cp_build_qualified_type_real (type,
cp_type_quals (t)
| cp_type_quals (type),
complain);
}
case DECLTYPE_TYPE:
{
tree type;
++cp_unevaluated_operand;
++c_inhibit_evaluation_warnings;
type = tsubst_copy_and_build (DECLTYPE_TYPE_EXPR (t), args,
complain|tf_decltype, in_decl,
/*function_p*/false,
/*integral_constant_expression*/false);
--cp_unevaluated_operand;
--c_inhibit_evaluation_warnings;
if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
type = lambda_capture_field_type (type,
false /*explicit_init*/,
DECLTYPE_FOR_REF_CAPTURE (t));
else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
type = lambda_proxy_type (type);
else
{
bool id = DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t);
if (id && TREE_CODE (DECLTYPE_TYPE_EXPR (t)) == BIT_NOT_EXPR
&& EXPR_P (type))
/* In a template ~id could be either a complement expression
or an unqualified-id naming a destructor; if instantiating
it produces an expression, it's not an id-expression or
member access. */
id = false;
type = finish_decltype_type (type, id, complain);
}
return cp_build_qualified_type_real (type,
cp_type_quals (t)
| cp_type_quals (type),
complain | tf_ignore_bad_quals);
}
case UNDERLYING_TYPE:
{
tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
complain, in_decl);
return finish_underlying_type (type);
}
case TYPE_ARGUMENT_PACK:
case NONTYPE_ARGUMENT_PACK:
{
tree r;
if (code == NONTYPE_ARGUMENT_PACK)
r = make_node (code);
else
r = cxx_make_type (code);
tree pack_args = ARGUMENT_PACK_ARGS (t);
pack_args = tsubst_template_args (pack_args, args, complain, in_decl);
SET_ARGUMENT_PACK_ARGS (r, pack_args);
return r;
}
case VOID_CST:
case INTEGER_CST:
case REAL_CST:
case STRING_CST:
case PLUS_EXPR:
case MINUS_EXPR:
case NEGATE_EXPR:
case NOP_EXPR:
case INDIRECT_REF:
case ADDR_EXPR:
case CALL_EXPR:
case ARRAY_REF:
case SCOPE_REF:
/* We should use one of the expression tsubsts for these codes. */
gcc_unreachable ();
default:
sorry ("use of %qs in template", get_tree_code_name (code));
return error_mark_node;
}
}
/* tsubst a BASELINK. OBJECT_TYPE, if non-NULL, is the type of the
expression on the left-hand side of the "." or "->" operator. We
only do the lookup if we had a dependent BASELINK. Otherwise we
adjust it onto the instantiated heirarchy. */
static tree
tsubst_baselink (tree baselink, tree object_type,
tree args, tsubst_flags_t complain, tree in_decl)
{
bool qualified_p = BASELINK_QUALIFIED_P (baselink);
tree qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
qualifying_scope = tsubst (qualifying_scope, args, complain, in_decl);
tree optype = BASELINK_OPTYPE (baselink);
optype = tsubst (optype, args, complain, in_decl);
tree template_args = NULL_TREE;
bool template_id_p = false;
tree fns = BASELINK_FUNCTIONS (baselink);
if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
{
template_id_p = true;
template_args = TREE_OPERAND (fns, 1);
fns = TREE_OPERAND (fns, 0);
if (template_args)
template_args = tsubst_template_args (template_args, args,
complain, in_decl);
}
tree binfo_type = BINFO_TYPE (BASELINK_BINFO (baselink));
binfo_type = tsubst (binfo_type, args, complain, in_decl);
bool dependent_p = (binfo_type != BINFO_TYPE (BASELINK_BINFO (baselink))
|| optype != BASELINK_OPTYPE (baselink));
if (dependent_p)
{
tree name = OVL_NAME (fns);
if (IDENTIFIER_CONV_OP_P (name))
name = make_conv_op_name (optype);
if (name == complete_dtor_identifier)
/* Treat as-if non-dependent below. */
dependent_p = false;
baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
if (!baselink)
{
if ((complain & tf_error)
&& constructor_name_p (name, qualifying_scope))
error ("cannot call constructor %<%T::%D%> directly",
qualifying_scope, name);
return error_mark_node;
}
if (BASELINK_P (baselink))
fns = BASELINK_FUNCTIONS (baselink);
}
else
{
/* We're going to overwrite pieces below, make a duplicate. */
baselink = copy_node (baselink);
if (qualifying_scope != BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink)))
{
/* The decl we found was from non-dependent scope, but we still need
to update the binfos for the instantiated qualifying_scope. */
BASELINK_ACCESS_BINFO (baselink) = TYPE_BINFO (qualifying_scope);
BASELINK_BINFO (baselink) = lookup_base (qualifying_scope, binfo_type,
ba_unique, NULL, complain);
}
}
/* If lookup found a single function, mark it as used at this point.
(If lookup found multiple functions the one selected later by
overload resolution will be marked as used at that point.) */
if (!template_id_p && !really_overloaded_fn (fns))
{
tree fn = OVL_FIRST (fns);
bool ok = mark_used (fn, complain);
if (!ok && !(complain & tf_error))
return error_mark_node;
if (ok && BASELINK_P (baselink))
/* We might have instantiated an auto function. */
TREE_TYPE (baselink) = TREE_TYPE (fn);
}
if (BASELINK_P (baselink))
{
/* Add back the template arguments, if present. */
if (template_id_p)
BASELINK_FUNCTIONS (baselink)
= build2 (TEMPLATE_ID_EXPR, unknown_type_node, fns, template_args);
/* Update the conversion operator type. */
BASELINK_OPTYPE (baselink) = optype;
}
if (!object_type)
object_type = current_class_type;
if (qualified_p || !dependent_p)
{
baselink = adjust_result_of_qualified_name_lookup (baselink,
qualifying_scope,
object_type);
if (!qualified_p)
/* We need to call adjust_result_of_qualified_name_lookup in case the
destructor names a base class, but we unset BASELINK_QUALIFIED_P
so that we still get virtual function binding. */
BASELINK_QUALIFIED_P (baselink) = false;
}
return baselink;
}
/* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
true if the qualified-id will be a postfix-expression in-and-of
itself; false if more of the postfix-expression follows the
QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
of "&". */
static tree
tsubst_qualified_id (tree qualified_id, tree args,
tsubst_flags_t complain, tree in_decl,
bool done, bool address_p)
{
tree expr;
tree scope;
tree name;
bool is_template;
tree template_args;
location_t loc = UNKNOWN_LOCATION;
gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
/* Figure out what name to look up. */
name = TREE_OPERAND (qualified_id, 1);
if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
{
is_template = true;
loc = EXPR_LOCATION (name);
template_args = TREE_OPERAND (name, 1);
if (template_args)
template_args = tsubst_template_args (template_args, args,
complain, in_decl);
if (template_args == error_mark_node)
return error_mark_node;
name = TREE_OPERAND (name, 0);
}
else
{
is_template = false;
template_args = NULL_TREE;
}
/* Substitute into the qualifying scope. When there are no ARGS, we
are just trying to simplify a non-dependent expression. In that
case the qualifying scope may be dependent, and, in any case,
substituting will not help. */
scope = TREE_OPERAND (qualified_id, 0);
if (args)
{
scope = tsubst (scope, args, complain, in_decl);
expr = tsubst_copy (name, args, complain, in_decl);
}
else
expr = name;
if (dependent_scope_p (scope))
{
if (is_template)
expr = build_min_nt_loc (loc, TEMPLATE_ID_EXPR, expr, template_args);
tree r = build_qualified_name (NULL_TREE, scope, expr,
QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (qualified_id);
return r;
}
if (!BASELINK_P (name) && !DECL_P (expr))
{
if (TREE_CODE (expr) == BIT_NOT_EXPR)
{
/* A BIT_NOT_EXPR is used to represent a destructor. */
if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
{
error ("qualifying type %qT does not match destructor name ~%qT",
scope, TREE_OPERAND (expr, 0));
expr = error_mark_node;
}
else
expr = lookup_qualified_name (scope, complete_dtor_identifier,
/*is_type_p=*/0, false);
}
else
expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
{
if (complain & tf_error)
{
error ("dependent-name %qE is parsed as a non-type, but "
"instantiation yields a type", qualified_id);
inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
}
return error_mark_node;
}
}
if (DECL_P (expr))
{
check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
scope);
/* Remember that there was a reference to this entity. */
if (!mark_used (expr, complain) && !(complain & tf_error))
return error_mark_node;
}
if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
{
if (complain & tf_error)
qualified_name_lookup_error (scope,
TREE_OPERAND (qualified_id, 1),
expr, input_location);
return error_mark_node;
}
if (is_template)
{
/* We may be repeating a check already done during parsing, but
if it was well-formed and passed then, it will pass again
now, and if it didn't, we wouldn't have got here. The case
we want to catch is when we couldn't tell then, and can now,
namely when templ prior to substitution was an
identifier. */
if (flag_concepts && check_auto_in_tmpl_args (expr, template_args))
return error_mark_node;
if (variable_template_p (expr))
expr = lookup_and_finish_template_variable (expr, template_args,
complain);
else
expr = lookup_template_function (expr, template_args);
}
if (expr == error_mark_node && complain & tf_error)
qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
expr, input_location);
else if (TYPE_P (scope))
{
expr = (adjust_result_of_qualified_name_lookup
(expr, scope, current_nonlambda_class_type ()));
expr = (finish_qualified_id_expr
(scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
/*template_arg_p=*/false, complain));
}
/* Expressions do not generally have reference type. */
if (TREE_CODE (expr) != SCOPE_REF
/* However, if we're about to form a pointer-to-member, we just
want the referenced member referenced. */
&& TREE_CODE (expr) != OFFSET_REF)
expr = convert_from_reference (expr);
if (REF_PARENTHESIZED_P (qualified_id))
expr = force_paren_expr (expr);
return expr;
}
/* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
initializer, DECL is the substituted VAR_DECL. Other arguments are as
for tsubst. */
static tree
tsubst_init (tree init, tree decl, tree args,
tsubst_flags_t complain, tree in_decl)
{
if (!init)
return NULL_TREE;
init = tsubst_expr (init, args, complain, in_decl, false);
tree type = TREE_TYPE (decl);
if (!init && type != error_mark_node)
{
if (tree auto_node = type_uses_auto (type))
{
if (!CLASS_PLACEHOLDER_TEMPLATE (auto_node))
{
if (complain & tf_error)
error ("initializer for %q#D expands to an empty list "
"of expressions", decl);
return error_mark_node;
}
}
else if (!dependent_type_p (type))
{
/* If we had an initializer but it
instantiated to nothing,
value-initialize the object. This will
only occur when the initializer was a
pack expansion where the parameter packs
used in that expansion were of length
zero. */
init = build_value_init (type, complain);
if (TREE_CODE (init) == AGGR_INIT_EXPR)
init = get_target_expr_sfinae (init, complain);
if (TREE_CODE (init) == TARGET_EXPR)
TARGET_EXPR_DIRECT_INIT_P (init) = true;
}
}
return init;
}
/* Like tsubst, but deals with expressions. This function just replaces
template parms; to finish processing the resultant expression, use
tsubst_copy_and_build or tsubst_expr. */
static tree
tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
{
enum tree_code code;
tree r;
if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
return t;
code = TREE_CODE (t);
switch (code)
{
case PARM_DECL:
r = retrieve_local_specialization (t);
if (r == NULL_TREE)
{
/* We get here for a use of 'this' in an NSDMI. */
if (DECL_NAME (t) == this_identifier && current_class_ptr)
return current_class_ptr;
/* This can happen for a parameter name used later in a function
declaration (such as in a late-specified return type). Just
make a dummy decl, since it's only used for its type. */
gcc_assert (cp_unevaluated_operand != 0);
r = tsubst_decl (t, args, complain);
/* Give it the template pattern as its context; its true context
hasn't been instantiated yet and this is good enough for
mangling. */
DECL_CONTEXT (r) = DECL_CONTEXT (t);
}
if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
r = argument_pack_select_arg (r);
if (!mark_used (r, complain) && !(complain & tf_error))
return error_mark_node;
return r;
case CONST_DECL:
{
tree enum_type;
tree v;
if (DECL_TEMPLATE_PARM_P (t))
return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
/* There is no need to substitute into namespace-scope
enumerators. */
if (DECL_NAMESPACE_SCOPE_P (t))
return t;
/* If ARGS is NULL, then T is known to be non-dependent. */
if (args == NULL_TREE)
return scalar_constant_value (t);
/* Unfortunately, we cannot just call lookup_name here.
Consider:
template <int I> int f() {
enum E { a = I };
struct S { void g() { E e = a; } };
};
When we instantiate f<7>::S::g(), say, lookup_name is not
clever enough to find f<7>::a. */
enum_type
= tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
/*entering_scope=*/0);
for (v = TYPE_VALUES (enum_type);
v != NULL_TREE;
v = TREE_CHAIN (v))
if (TREE_PURPOSE (v) == DECL_NAME (t))
return TREE_VALUE (v);
/* We didn't find the name. That should never happen; if
name-lookup found it during preliminary parsing, we
should find it again here during instantiation. */
gcc_unreachable ();
}
return t;
case FIELD_DECL:
if (DECL_CONTEXT (t))
{
tree ctx;
ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
/*entering_scope=*/1);
if (ctx != DECL_CONTEXT (t))
{
tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
if (!r)
{
if (complain & tf_error)
error ("using invalid field %qD", t);
return error_mark_node;
}
return r;
}
}
return t;
case VAR_DECL:
case FUNCTION_DECL:
if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
r = tsubst (t, args, complain, in_decl);
else if (local_variable_p (t)
&& uses_template_parms (DECL_CONTEXT (t)))
{
r = retrieve_local_specialization (t);
if (r == NULL_TREE)
{
/* First try name lookup to find the instantiation. */
r = lookup_name (DECL_NAME (t));
if (r)
{
if (!VAR_P (r))
{
/* During error-recovery we may find a non-variable,
even an OVERLOAD: just bail out and avoid ICEs and
duplicate diagnostics (c++/62207). */
gcc_assert (seen_error ());
return error_mark_node;
}
if (!is_capture_proxy (r))
{
/* Make sure the one we found is the one we want. */
tree ctx = enclosing_instantiation_of (DECL_CONTEXT (t));
if (ctx != DECL_CONTEXT (r))
r = NULL_TREE;
}
}
if (r)
/* OK */;
else
{
/* This can happen for a variable used in a
late-specified return type of a local lambda, or for a
local static or constant. Building a new VAR_DECL
should be OK in all those cases. */
r = tsubst_decl (t, args, complain);
if (local_specializations)
/* Avoid infinite recursion (79640). */
register_local_specialization (r, t);
if (decl_maybe_constant_var_p (r))
{
/* We can't call cp_finish_decl, so handle the
initializer by hand. */
tree init = tsubst_init (DECL_INITIAL (t), r, args,
complain, in_decl);
if (!processing_template_decl)
init = maybe_constant_init (init);
if (processing_template_decl
? potential_constant_expression (init)
: reduced_constant_expression_p (init))
DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
= TREE_CONSTANT (r) = true;
DECL_INITIAL (r) = init;
if (tree auto_node = type_uses_auto (TREE_TYPE (r)))
TREE_TYPE (r)
= do_auto_deduction (TREE_TYPE (r), init, auto_node,
complain, adc_variable_type);
}
gcc_assert (cp_unevaluated_operand || TREE_STATIC (r)
|| decl_constant_var_p (r)
|| seen_error ());
if (!processing_template_decl
&& !TREE_STATIC (r))
r = process_outer_var_ref (r, complain);
}
/* Remember this for subsequent uses. */
if (local_specializations)
register_local_specialization (r, t);
}
if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
r = argument_pack_select_arg (r);
}
else
r = t;
if (!mark_used (r, complain))
return error_mark_node;
return r;
case NAMESPACE_DECL:
return t;
case OVERLOAD:
return t;
case BASELINK:
return tsubst_baselink (t, current_nonlambda_class_type (),
args, complain, in_decl);
case TEMPLATE_DECL:
if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
args, complain, in_decl);
else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
return tsubst (t, args, complain, in_decl);
else if (DECL_CLASS_SCOPE_P (t)
&& uses_template_parms (DECL_CONTEXT (t)))
{
/* Template template argument like the following example need
special treatment:
template <template <class> class TT> struct C {};
template <class T> struct D {
template <class U> struct E {};
C<E> c; // #1
};
D<int> d; // #2
We are processing the template argument `E' in #1 for
the template instantiation #2. Originally, `E' is a
TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
have to substitute this with one having context `D<int>'. */
tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
if (dependent_scope_p (context))
{
/* When rewriting a constructor into a deduction guide, a
non-dependent name can become dependent, so memtmpl<args>
becomes context::template memtmpl<args>. */
tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
return build_qualified_name (type, context, DECL_NAME (t),
/*template*/true);
}
return lookup_field (context, DECL_NAME(t), 0, false);
}
else
/* Ordinary template template argument. */
return t;
case NON_LVALUE_EXPR:
case VIEW_CONVERT_EXPR:
{
/* Handle location wrappers by substituting the wrapped node
first, *then* reusing the resulting type. Doing the type
first ensures that we handle template parameters and
parameter pack expansions. */
if (location_wrapper_p (t))
{
tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args,
complain, in_decl);
return maybe_wrap_with_location (op0, EXPR_LOCATION (t));
}
tree op = TREE_OPERAND (t, 0);
if (code == VIEW_CONVERT_EXPR
&& TREE_CODE (op) == TEMPLATE_PARM_INDEX)
{
/* Wrapper to make a C++20 template parameter object const. */
op = tsubst_copy (op, args, complain, in_decl);
if (TREE_CODE (op) == TEMPLATE_PARM_INDEX)
{
tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
return build1 (code, type, op);
}
else if (!CP_TYPE_CONST_P (TREE_TYPE (op)))
{
/* The template argument is not const, presumably because
it is still dependent, and so not the const template parm
object. */
tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
gcc_checking_assert (same_type_ignoring_top_level_qualifiers_p
(type, TREE_TYPE (op)));
if (TREE_CODE (op) == CONSTRUCTOR
|| TREE_CODE (op) == IMPLICIT_CONV_EXPR)
{
/* Don't add a wrapper to these. */
op = copy_node (op);
TREE_TYPE (op) = type;
}
else
/* Do add a wrapper otherwise. */
op = build1 (code, type, op);
}
return op;
}
/* force_paren_expr can also create a VIEW_CONVERT_EXPR. */
else if (code == VIEW_CONVERT_EXPR && REF_PARENTHESIZED_P (t))
{
op = tsubst_copy (op, args, complain, in_decl);
op = build1 (code, TREE_TYPE (op), op);
REF_PARENTHESIZED_P (op) = true;
return op;
}
/* We shouldn't see any other uses of these in templates. */
gcc_unreachable ();
}
case CAST_EXPR:
case REINTERPRET_CAST_EXPR:
case CONST_CAST_EXPR:
case STATIC_CAST_EXPR:
case DYNAMIC_CAST_EXPR:
case IMPLICIT_CONV_EXPR:
case CONVERT_EXPR:
case NOP_EXPR:
{
tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
return build1 (code, type, op0);
}
case SIZEOF_EXPR:
if (PACK_EXPANSION_P (TREE_OPERAND (t, 0))
|| ARGUMENT_PACK_P (TREE_OPERAND (t, 0)))
{
tree expanded, op = TREE_OPERAND (t, 0);
int len = 0;
if (SIZEOF_EXPR_TYPE_P (t))
op = TREE_TYPE (op);
++cp_unevaluated_operand;
++c_inhibit_evaluation_warnings;
/* We only want to compute the number of arguments. */
if (PACK_EXPANSION_P (op))
expanded = tsubst_pack_expansion (op, args, complain, in_decl);
else
expanded = tsubst_template_args (ARGUMENT_PACK_ARGS (op),
args, complain, in_decl);
--cp_unevaluated_operand;
--c_inhibit_evaluation_warnings;
if (TREE_CODE (expanded) == TREE_VEC)
{
len = TREE_VEC_LENGTH (expanded);
/* Set TREE_USED for the benefit of -Wunused. */
for (int i = 0; i < len; i++)
if (DECL_P (TREE_VEC_ELT (expanded, i)))
TREE_USED (TREE_VEC_ELT (expanded, i)) = true;
}
if (expanded == error_mark_node)
return error_mark_node;
else if (PACK_EXPANSION_P (expanded)
|| (TREE_CODE (expanded) == TREE_VEC
&& pack_expansion_args_count (expanded)))
{
if (PACK_EXPANSION_P (expanded))
/* OK. */;
else if (TREE_VEC_LENGTH (expanded) == 1)
expanded = TREE_VEC_ELT (expanded, 0);
else
expanded = make_argument_pack (expanded);
if (TYPE_P (expanded))
return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
false,
complain & tf_error);
else
return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
complain & tf_error);
}
else
return build_int_cst (size_type_node, len);
}
if (SIZEOF_EXPR_TYPE_P (t))
{
r = tsubst (TREE_TYPE (TREE_OPERAND (t, 0)),
args, complain, in_decl);
r = build1 (NOP_EXPR, r, error_mark_node);
r = build1 (SIZEOF_EXPR,
tsubst (TREE_TYPE (t), args, complain, in_decl), r);
SIZEOF_EXPR_TYPE_P (r) = 1;
return r;
}
/* Fall through */
case INDIRECT_REF:
case NEGATE_EXPR:
case TRUTH_NOT_EXPR:
case BIT_NOT_EXPR:
case ADDR_EXPR:
case UNARY_PLUS_EXPR: /* Unary + */
case ALIGNOF_EXPR:
case AT_ENCODE_EXPR:
case ARROW_EXPR:
case THROW_EXPR:
case TYPEID_EXPR:
case REALPART_EXPR:
case IMAGPART_EXPR:
case PAREN_EXPR:
{
tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
r = build1 (code, type, op0);
if (code == ALIGNOF_EXPR)
ALIGNOF_EXPR_STD_P (r) = ALIGNOF_EXPR_STD_P (t);
return r;
}
case COMPONENT_REF:
{
tree object;
tree name;
object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
name = TREE_OPERAND (t, 1);
if (TREE_CODE (name) == BIT_NOT_EXPR)
{
name = tsubst_copy (TREE_OPERAND (name, 0), args,
complain, in_decl);
name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
}
else if (TREE_CODE (name) == SCOPE_REF
&& TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
{
tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
complain, in_decl);
name = TREE_OPERAND (name, 1);
name = tsubst_copy (TREE_OPERAND (name, 0), args,
complain, in_decl);
name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
name = build_qualified_name (/*type=*/NULL_TREE,
base, name,
/*template_p=*/false);
}
else if (BASELINK_P (name))
name = tsubst_baselink (name,
non_reference (TREE_TYPE (object)),
args, complain,
in_decl);
else
name = tsubst_copy (name, args, complain, in_decl);
return build_nt (COMPONENT_REF, object, name, NULL_TREE);
}
case PLUS_EXPR:
case MINUS_EXPR:
case MULT_EXPR:
case TRUNC_DIV_EXPR:
case CEIL_DIV_EXPR:
case FLOOR_DIV_EXPR:
case ROUND_DIV_EXPR:
case EXACT_DIV_EXPR:
case BIT_AND_EXPR:
case BIT_IOR_EXPR:
case BIT_XOR_EXPR:
case TRUNC_MOD_EXPR:
case FLOOR_MOD_EXPR:
case TRUTH_ANDIF_EXPR:
case TRUTH_ORIF_EXPR:
case TRUTH_AND_EXPR:
case TRUTH_OR_EXPR:
case RSHIFT_EXPR:
case LSHIFT_EXPR:
case RROTATE_EXPR:
case LROTATE_EXPR:
case EQ_EXPR:
case NE_EXPR:
case MAX_EXPR:
case MIN_EXPR:
case LE_EXPR:
case GE_EXPR:
case LT_EXPR:
case GT_EXPR:
case COMPOUND_EXPR:
case DOTSTAR_EXPR:
case MEMBER_REF:
case PREDECREMENT_EXPR:
case PREINCREMENT_EXPR:
case POSTDECREMENT_EXPR:
case POSTINCREMENT_EXPR:
{
tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
return build_nt (code, op0, op1);
}
case SCOPE_REF:
{
tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
return build_qualified_name (/*type=*/NULL_TREE, op0, op1,
QUALIFIED_NAME_IS_TEMPLATE (t));
}
case ARRAY_REF:
{
tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
return build_nt (ARRAY_REF, op0, op1, NULL_TREE, NULL_TREE);
}
case CALL_EXPR:
{
int n = VL_EXP_OPERAND_LENGTH (t);
tree result = build_vl_exp (CALL_EXPR, n);
int i;
for (i = 0; i < n; i++)
TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
complain, in_decl);
return result;
}
case COND_EXPR:
case MODOP_EXPR:
case PSEUDO_DTOR_EXPR:
case VEC_PERM_EXPR:
{
tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
tree op2 = tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl);
r = build_nt (code, op0, op1, op2);
TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
return r;
}
case NEW_EXPR:
{
tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
tree op2 = tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl);
r = build_nt (code, op0, op1, op2);
NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
return r;
}
case DELETE_EXPR:
{
tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
r = build_nt (code, op0<