blob: 771a19bc4026e65f8699d765218c3306dda14e79 [file] [log] [blame]
/* Handle initialization things in C++.
Copyright (C) 1987-2021 Free Software Foundation, Inc.
Contributed by Michael Tiemann (tiemann@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/>. */
/* High-level class interface. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "target.h"
#include "cp-tree.h"
#include "stringpool.h"
#include "varasm.h"
#include "gimplify.h"
#include "c-family/c-ubsan.h"
#include "intl.h"
#include "stringpool.h"
#include "attribs.h"
#include "asan.h"
#include "stor-layout.h"
#include "pointer-query.h"
static bool begin_init_stmts (tree *, tree *);
static tree finish_init_stmts (bool, tree, tree);
static void construct_virtual_base (tree, tree);
static bool expand_aggr_init_1 (tree, tree, tree, tree, int, tsubst_flags_t);
static bool expand_default_init (tree, tree, tree, tree, int, tsubst_flags_t);
static void perform_member_init (tree, tree);
static int member_init_ok_or_else (tree, tree, tree);
static void expand_virtual_init (tree, tree);
static tree sort_mem_initializers (tree, tree);
static tree initializing_context (tree);
static void expand_cleanup_for_base (tree, tree);
static tree dfs_initialize_vtbl_ptrs (tree, void *);
static tree build_field_list (tree, tree, int *);
static int diagnose_uninitialized_cst_or_ref_member_1 (tree, tree, bool, bool);
static GTY(()) tree fn;
/* We are about to generate some complex initialization code.
Conceptually, it is all a single expression. However, we may want
to include conditionals, loops, and other such statement-level
constructs. Therefore, we build the initialization code inside a
statement-expression. This function starts such an expression.
STMT_EXPR_P and COMPOUND_STMT_P are filled in by this function;
pass them back to finish_init_stmts when the expression is
complete. */
static bool
begin_init_stmts (tree *stmt_expr_p, tree *compound_stmt_p)
{
bool is_global = !building_stmt_list_p ();
*stmt_expr_p = begin_stmt_expr ();
*compound_stmt_p = begin_compound_stmt (BCS_NO_SCOPE);
return is_global;
}
/* Finish out the statement-expression begun by the previous call to
begin_init_stmts. Returns the statement-expression itself. */
static tree
finish_init_stmts (bool is_global, tree stmt_expr, tree compound_stmt)
{
finish_compound_stmt (compound_stmt);
stmt_expr = finish_stmt_expr (stmt_expr, true);
gcc_assert (!building_stmt_list_p () == is_global);
return stmt_expr;
}
/* Constructors */
/* Called from initialize_vtbl_ptrs via dfs_walk. BINFO is the base
which we want to initialize the vtable pointer for, DATA is
TREE_LIST whose TREE_VALUE is the this ptr expression. */
static tree
dfs_initialize_vtbl_ptrs (tree binfo, void *data)
{
if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
return dfs_skip_bases;
if (!BINFO_PRIMARY_P (binfo) || BINFO_VIRTUAL_P (binfo))
{
tree base_ptr = TREE_VALUE ((tree) data);
base_ptr = build_base_path (PLUS_EXPR, base_ptr, binfo, /*nonnull=*/1,
tf_warning_or_error);
expand_virtual_init (binfo, base_ptr);
}
return NULL_TREE;
}
/* Initialize all the vtable pointers in the object pointed to by
ADDR. */
void
initialize_vtbl_ptrs (tree addr)
{
tree list;
tree type;
type = TREE_TYPE (TREE_TYPE (addr));
list = build_tree_list (type, addr);
/* Walk through the hierarchy, initializing the vptr in each base
class. We do these in pre-order because we can't find the virtual
bases for a class until we've initialized the vtbl for that
class. */
dfs_walk_once (TYPE_BINFO (type), dfs_initialize_vtbl_ptrs, NULL, list);
}
/* Return an expression for the zero-initialization of an object with
type T. This expression will either be a constant (in the case
that T is a scalar), or a CONSTRUCTOR (in the case that T is an
aggregate), or NULL (in the case that T does not require
initialization). In either case, the value can be used as
DECL_INITIAL for a decl of the indicated TYPE; it is a valid static
initializer. If NELTS is non-NULL, and TYPE is an ARRAY_TYPE, NELTS
is the number of elements in the array. If STATIC_STORAGE_P is
TRUE, initializers are only generated for entities for which
zero-initialization does not simply mean filling the storage with
zero bytes. FIELD_SIZE, if non-NULL, is the bit size of the field,
subfields with bit positions at or above that bit size shouldn't
be added. Note that this only works when the result is assigned
to a base COMPONENT_REF; if we only have a pointer to the base subobject,
expand_assignment will end up clearing the full size of TYPE. */
static tree
build_zero_init_1 (tree type, tree nelts, bool static_storage_p,
tree field_size)
{
tree init = NULL_TREE;
/* [dcl.init]
To zero-initialize an object of type T means:
-- if T is a scalar type, the storage is set to the value of zero
converted to T.
-- if T is a non-union class type, the storage for each non-static
data member and each base-class subobject is zero-initialized.
-- if T is a union type, the storage for its first data member is
zero-initialized.
-- if T is an array type, the storage for each element is
zero-initialized.
-- if T is a reference type, no initialization is performed. */
gcc_assert (nelts == NULL_TREE || TREE_CODE (nelts) == INTEGER_CST);
if (type == error_mark_node)
;
else if (static_storage_p && zero_init_p (type))
/* In order to save space, we do not explicitly build initializers
for items that do not need them. GCC's semantics are that
items with static storage duration that are not otherwise
initialized are initialized to zero. */
;
else if (TYPE_PTR_OR_PTRMEM_P (type))
init = fold (convert (type, nullptr_node));
else if (NULLPTR_TYPE_P (type))
init = build_int_cst (type, 0);
else if (SCALAR_TYPE_P (type))
init = build_zero_cst (type);
else if (RECORD_OR_UNION_CODE_P (TREE_CODE (type)))
{
tree field;
vec<constructor_elt, va_gc> *v = NULL;
/* Iterate over the fields, building initializations. */
for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
{
if (TREE_CODE (field) != FIELD_DECL)
continue;
if (TREE_TYPE (field) == error_mark_node)
continue;
/* Don't add virtual bases for base classes if they are beyond
the size of the current field, that means it is present
somewhere else in the object. */
if (field_size)
{
tree bitpos = bit_position (field);
if (TREE_CODE (bitpos) == INTEGER_CST
&& !tree_int_cst_lt (bitpos, field_size))
continue;
}
/* Note that for class types there will be FIELD_DECLs
corresponding to base classes as well. Thus, iterating
over TYPE_FIELDs will result in correct initialization of
all of the subobjects. */
if (!static_storage_p || !zero_init_p (TREE_TYPE (field)))
{
tree new_field_size
= (DECL_FIELD_IS_BASE (field)
&& DECL_SIZE (field)
&& TREE_CODE (DECL_SIZE (field)) == INTEGER_CST)
? DECL_SIZE (field) : NULL_TREE;
tree value = build_zero_init_1 (TREE_TYPE (field),
/*nelts=*/NULL_TREE,
static_storage_p,
new_field_size);
if (value)
CONSTRUCTOR_APPEND_ELT(v, field, value);
}
/* For unions, only the first field is initialized. */
if (TREE_CODE (type) == UNION_TYPE)
break;
}
/* Build a constructor to contain the initializations. */
init = build_constructor (type, v);
}
else if (TREE_CODE (type) == ARRAY_TYPE)
{
tree max_index;
vec<constructor_elt, va_gc> *v = NULL;
/* Iterate over the array elements, building initializations. */
if (nelts)
max_index = fold_build2_loc (input_location, MINUS_EXPR,
TREE_TYPE (nelts), nelts,
build_one_cst (TREE_TYPE (nelts)));
/* Treat flexible array members like [0] arrays. */
else if (TYPE_DOMAIN (type) == NULL_TREE)
return NULL_TREE;
else
max_index = array_type_nelts (type);
/* If we have an error_mark here, we should just return error mark
as we don't know the size of the array yet. */
if (max_index == error_mark_node)
return error_mark_node;
gcc_assert (TREE_CODE (max_index) == INTEGER_CST);
/* A zero-sized array, which is accepted as an extension, will
have an upper bound of -1. */
if (!integer_minus_onep (max_index))
{
constructor_elt ce;
/* If this is a one element array, we just use a regular init. */
if (integer_zerop (max_index))
ce.index = size_zero_node;
else
ce.index = build2 (RANGE_EXPR, sizetype, size_zero_node,
max_index);
ce.value = build_zero_init_1 (TREE_TYPE (type), /*nelts=*/NULL_TREE,
static_storage_p, NULL_TREE);
if (ce.value)
{
vec_alloc (v, 1);
v->quick_push (ce);
}
}
/* Build a constructor to contain the initializations. */
init = build_constructor (type, v);
}
else if (VECTOR_TYPE_P (type))
init = build_zero_cst (type);
else
gcc_assert (TYPE_REF_P (type));
/* In all cases, the initializer is a constant. */
if (init)
TREE_CONSTANT (init) = 1;
return init;
}
/* Return an expression for the zero-initialization of an object with
type T. This expression will either be a constant (in the case
that T is a scalar), or a CONSTRUCTOR (in the case that T is an
aggregate), or NULL (in the case that T does not require
initialization). In either case, the value can be used as
DECL_INITIAL for a decl of the indicated TYPE; it is a valid static
initializer. If NELTS is non-NULL, and TYPE is an ARRAY_TYPE, NELTS
is the number of elements in the array. If STATIC_STORAGE_P is
TRUE, initializers are only generated for entities for which
zero-initialization does not simply mean filling the storage with
zero bytes. */
tree
build_zero_init (tree type, tree nelts, bool static_storage_p)
{
return build_zero_init_1 (type, nelts, static_storage_p, NULL_TREE);
}
/* Return a suitable initializer for value-initializing an object of type
TYPE, as described in [dcl.init]. */
tree
build_value_init (tree type, tsubst_flags_t complain)
{
/* [dcl.init]
To value-initialize an object of type T means:
- if T is a class type (clause 9) with either no default constructor
(12.1) or a default constructor that is user-provided or deleted,
then the object is default-initialized;
- if T is a (possibly cv-qualified) class type without a user-provided
or deleted default constructor, then the object is zero-initialized
and the semantic constraints for default-initialization are checked,
and if T has a non-trivial default constructor, the object is
default-initialized;
- if T is an array type, then each element is value-initialized;
- otherwise, the object is zero-initialized.
A program that calls for default-initialization or
value-initialization of an entity of reference type is ill-formed. */
/* The AGGR_INIT_EXPR tweaking below breaks in templates. */
gcc_assert (!processing_template_decl
|| (SCALAR_TYPE_P (type) || TREE_CODE (type) == ARRAY_TYPE));
if (CLASS_TYPE_P (type) && type_build_ctor_call (type))
{
tree ctor
= build_special_member_call (NULL_TREE, complete_ctor_identifier,
NULL, type, LOOKUP_NORMAL, complain);
if (ctor == error_mark_node || TREE_CONSTANT (ctor))
return ctor;
tree fn = NULL_TREE;
if (TREE_CODE (ctor) == CALL_EXPR)
fn = get_callee_fndecl (ctor);
ctor = build_aggr_init_expr (type, ctor);
if (fn && user_provided_p (fn))
return ctor;
else if (TYPE_HAS_COMPLEX_DFLT (type))
{
/* This is a class that needs constructing, but doesn't have
a user-provided constructor. So we need to zero-initialize
the object and then call the implicitly defined ctor.
This will be handled in simplify_aggr_init_expr. */
AGGR_INIT_ZERO_FIRST (ctor) = 1;
return ctor;
}
}
/* Discard any access checking during subobject initialization;
the checks are implied by the call to the ctor which we have
verified is OK (cpp0x/defaulted46.C). */
push_deferring_access_checks (dk_deferred);
tree r = build_value_init_noctor (type, complain);
pop_deferring_access_checks ();
return r;
}
/* Like build_value_init, but don't call the constructor for TYPE. Used
for base initializers. */
tree
build_value_init_noctor (tree type, tsubst_flags_t complain)
{
if (!COMPLETE_TYPE_P (type))
{
if (complain & tf_error)
error ("value-initialization of incomplete type %qT", type);
return error_mark_node;
}
/* FIXME the class and array cases should just use digest_init once it is
SFINAE-enabled. */
if (CLASS_TYPE_P (type))
{
gcc_assert (!TYPE_HAS_COMPLEX_DFLT (type)
|| errorcount != 0);
if (TREE_CODE (type) != UNION_TYPE)
{
tree field;
vec<constructor_elt, va_gc> *v = NULL;
/* Iterate over the fields, building initializations. */
for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
{
tree ftype, value;
if (TREE_CODE (field) != FIELD_DECL)
continue;
ftype = TREE_TYPE (field);
if (ftype == error_mark_node)
continue;
/* Ignore flexible array members for value initialization. */
if (TREE_CODE (ftype) == ARRAY_TYPE
&& !COMPLETE_TYPE_P (ftype)
&& !TYPE_DOMAIN (ftype)
&& COMPLETE_TYPE_P (TREE_TYPE (ftype))
&& (next_initializable_field (DECL_CHAIN (field))
== NULL_TREE))
continue;
/* Ignore unnamed zero-width bitfields. */
if (DECL_UNNAMED_BIT_FIELD (field)
&& integer_zerop (DECL_SIZE (field)))
continue;
/* We could skip vfields and fields of types with
user-defined constructors, but I think that won't improve
performance at all; it should be simpler in general just
to zero out the entire object than try to only zero the
bits that actually need it. */
/* Note that for class types there will be FIELD_DECLs
corresponding to base classes as well. Thus, iterating
over TYPE_FIELDs will result in correct initialization of
all of the subobjects. */
value = build_value_init (ftype, complain);
value = maybe_constant_init (value);
if (value == error_mark_node)
return error_mark_node;
CONSTRUCTOR_APPEND_ELT(v, field, value);
/* We shouldn't have gotten here for anything that would need
non-trivial initialization, and gimplify_init_ctor_preeval
would need to be fixed to allow it. */
gcc_assert (TREE_CODE (value) != TARGET_EXPR
&& TREE_CODE (value) != AGGR_INIT_EXPR);
}
/* Build a constructor to contain the zero- initializations. */
return build_constructor (type, v);
}
}
else if (TREE_CODE (type) == ARRAY_TYPE)
{
vec<constructor_elt, va_gc> *v = NULL;
/* Iterate over the array elements, building initializations. */
tree max_index = array_type_nelts (type);
/* If we have an error_mark here, we should just return error mark
as we don't know the size of the array yet. */
if (max_index == error_mark_node)
{
if (complain & tf_error)
error ("cannot value-initialize array of unknown bound %qT",
type);
return error_mark_node;
}
gcc_assert (TREE_CODE (max_index) == INTEGER_CST);
/* A zero-sized array, which is accepted as an extension, will
have an upper bound of -1. */
if (!tree_int_cst_equal (max_index, integer_minus_one_node))
{
constructor_elt ce;
/* If this is a one element array, we just use a regular init. */
if (tree_int_cst_equal (size_zero_node, max_index))
ce.index = size_zero_node;
else
ce.index = build2 (RANGE_EXPR, sizetype, size_zero_node, max_index);
ce.value = build_value_init (TREE_TYPE (type), complain);
ce.value = maybe_constant_init (ce.value);
if (ce.value == error_mark_node)
return error_mark_node;
vec_alloc (v, 1);
v->quick_push (ce);
/* We shouldn't have gotten here for anything that would need
non-trivial initialization, and gimplify_init_ctor_preeval
would need to be fixed to allow it. */
gcc_assert (TREE_CODE (ce.value) != TARGET_EXPR
&& TREE_CODE (ce.value) != AGGR_INIT_EXPR);
}
/* Build a constructor to contain the initializations. */
return build_constructor (type, v);
}
else if (TREE_CODE (type) == FUNCTION_TYPE)
{
if (complain & tf_error)
error ("value-initialization of function type %qT", type);
return error_mark_node;
}
else if (TYPE_REF_P (type))
{
if (complain & tf_error)
error ("value-initialization of reference type %qT", type);
return error_mark_node;
}
return build_zero_init (type, NULL_TREE, /*static_storage_p=*/false);
}
/* Initialize current class with INIT, a TREE_LIST of
arguments for a target constructor. If TREE_LIST is void_type_node,
an empty initializer list was given. */
static void
perform_target_ctor (tree init)
{
tree decl = current_class_ref;
tree type = current_class_type;
finish_expr_stmt (build_aggr_init (decl, init,
LOOKUP_NORMAL|LOOKUP_DELEGATING_CONS,
tf_warning_or_error));
if (type_build_dtor_call (type))
{
tree expr = build_delete (input_location,
type, decl, sfk_complete_destructor,
LOOKUP_NORMAL
|LOOKUP_NONVIRTUAL
|LOOKUP_DESTRUCTOR,
0, tf_warning_or_error);
if (expr != error_mark_node
&& TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
finish_eh_cleanup (expr);
}
}
/* Return the non-static data initializer for FIELD_DECL MEMBER. */
static GTY((cache)) decl_tree_cache_map *nsdmi_inst;
tree
get_nsdmi (tree member, bool in_ctor, tsubst_flags_t complain)
{
tree init;
tree save_ccp = current_class_ptr;
tree save_ccr = current_class_ref;
if (DECL_LANG_SPECIFIC (member) && DECL_TEMPLATE_INFO (member))
{
init = DECL_INITIAL (DECL_TI_TEMPLATE (member));
location_t expr_loc
= cp_expr_loc_or_loc (init, DECL_SOURCE_LOCATION (member));
if (TREE_CODE (init) == DEFERRED_PARSE)
/* Unparsed. */;
else if (tree *slot = hash_map_safe_get (nsdmi_inst, member))
init = *slot;
/* Check recursive instantiation. */
else if (DECL_INSTANTIATING_NSDMI_P (member))
{
if (complain & tf_error)
error_at (expr_loc, "recursive instantiation of default member "
"initializer for %qD", member);
init = error_mark_node;
}
else
{
cp_evaluated ev;
location_t sloc = input_location;
input_location = expr_loc;
DECL_INSTANTIATING_NSDMI_P (member) = 1;
bool pushed = false;
tree ctx = DECL_CONTEXT (member);
processing_template_decl_sentinel ptds (/*reset*/false);
if (!currently_open_class (ctx))
{
if (!LOCAL_CLASS_P (ctx))
push_to_top_level ();
else
/* push_to_top_level would lose the necessary function context,
just reset processing_template_decl. */
processing_template_decl = 0;
push_nested_class (ctx);
push_deferring_access_checks (dk_no_deferred);
pushed = true;
}
inject_this_parameter (ctx, TYPE_UNQUALIFIED);
start_lambda_scope (member);
/* Do deferred instantiation of the NSDMI. */
init = (tsubst_copy_and_build
(init, DECL_TI_ARGS (member),
complain, member, /*function_p=*/false,
/*integral_constant_expression_p=*/false));
init = digest_nsdmi_init (member, init, complain);
finish_lambda_scope ();
DECL_INSTANTIATING_NSDMI_P (member) = 0;
if (init != error_mark_node)
hash_map_safe_put<hm_ggc> (nsdmi_inst, member, init);
if (pushed)
{
pop_deferring_access_checks ();
pop_nested_class ();
if (!LOCAL_CLASS_P (ctx))
pop_from_top_level ();
}
input_location = sloc;
}
}
else
init = DECL_INITIAL (member);
if (init && TREE_CODE (init) == DEFERRED_PARSE)
{
if (complain & tf_error)
{
error ("default member initializer for %qD required before the end "
"of its enclosing class", member);
inform (location_of (init), "defined here");
DECL_INITIAL (member) = error_mark_node;
}
init = error_mark_node;
}
if (in_ctor)
{
current_class_ptr = save_ccp;
current_class_ref = save_ccr;
}
else
{
/* Use a PLACEHOLDER_EXPR when we don't have a 'this' parameter to
refer to; constexpr evaluation knows what to do with it. */
current_class_ref = build0 (PLACEHOLDER_EXPR, DECL_CONTEXT (member));
current_class_ptr = build_address (current_class_ref);
}
/* Strip redundant TARGET_EXPR so we don't need to remap it, and
so the aggregate init code below will see a CONSTRUCTOR. */
bool simple_target = (init && SIMPLE_TARGET_EXPR_P (init));
if (simple_target)
init = TARGET_EXPR_INITIAL (init);
init = break_out_target_exprs (init, /*loc*/true);
if (in_ctor && init && TREE_CODE (init) == TARGET_EXPR)
/* This expresses the full initialization, prevent perform_member_init from
calling another constructor (58162). */
TARGET_EXPR_DIRECT_INIT_P (init) = true;
if (simple_target && TREE_CODE (init) != CONSTRUCTOR)
/* Now put it back so C++17 copy elision works. */
init = get_target_expr (init);
current_class_ptr = save_ccp;
current_class_ref = save_ccr;
return init;
}
/* Diagnose the flexible array MEMBER if its INITializer is non-null
and return true if so. Otherwise return false. */
bool
maybe_reject_flexarray_init (tree member, tree init)
{
tree type = TREE_TYPE (member);
if (!init
|| TREE_CODE (type) != ARRAY_TYPE
|| TYPE_DOMAIN (type))
return false;
/* Point at the flexible array member declaration if it's initialized
in-class, and at the ctor if it's initialized in a ctor member
initializer list. */
location_t loc;
if (DECL_INITIAL (member) == init
|| !current_function_decl
|| DECL_DEFAULTED_FN (current_function_decl))
loc = DECL_SOURCE_LOCATION (member);
else
loc = DECL_SOURCE_LOCATION (current_function_decl);
error_at (loc, "initializer for flexible array member %q#D", member);
return true;
}
/* If INIT's value can come from a call to std::initializer_list<T>::begin,
return that function. Otherwise, NULL_TREE. */
static tree
find_list_begin (tree init)
{
STRIP_NOPS (init);
while (TREE_CODE (init) == COMPOUND_EXPR)
init = TREE_OPERAND (init, 1);
STRIP_NOPS (init);
if (TREE_CODE (init) == COND_EXPR)
{
tree left = TREE_OPERAND (init, 1);
if (!left)
left = TREE_OPERAND (init, 0);
left = find_list_begin (left);
if (left)
return left;
return find_list_begin (TREE_OPERAND (init, 2));
}
if (TREE_CODE (init) == CALL_EXPR)
if (tree fn = get_callee_fndecl (init))
if (id_equal (DECL_NAME (fn), "begin")
&& is_std_init_list (DECL_CONTEXT (fn)))
return fn;
return NULL_TREE;
}
/* If INIT initializing MEMBER is copying the address of the underlying array
of an initializer_list, warn. */
static void
maybe_warn_list_ctor (tree member, tree init)
{
tree memtype = TREE_TYPE (member);
if (!init || !TYPE_PTR_P (memtype)
|| !is_list_ctor (current_function_decl))
return;
tree parm = FUNCTION_FIRST_USER_PARMTYPE (current_function_decl);
parm = TREE_VALUE (parm);
tree initlist = non_reference (parm);
/* Do not warn if the parameter is an lvalue reference to non-const. */
if (TYPE_REF_P (parm) && !TYPE_REF_IS_RVALUE (parm)
&& !CP_TYPE_CONST_P (initlist))
return;
tree targs = CLASSTYPE_TI_ARGS (initlist);
tree elttype = TREE_VEC_ELT (targs, 0);
if (!same_type_ignoring_top_level_qualifiers_p
(TREE_TYPE (memtype), elttype))
return;
tree begin = find_list_begin (init);
if (!begin)
return;
location_t loc = cp_expr_loc_or_input_loc (init);
warning_at (loc, OPT_Winit_list_lifetime,
"initializing %qD from %qE does not extend the lifetime "
"of the underlying array", member, begin);
}
/* Initialize MEMBER, a FIELD_DECL, with INIT, a TREE_LIST of
arguments. If TREE_LIST is void_type_node, an empty initializer
list was given; if NULL_TREE no initializer was given. */
static void
perform_member_init (tree member, tree init)
{
tree decl;
tree type = TREE_TYPE (member);
/* Use the non-static data member initializer if there was no
mem-initializer for this field. */
if (init == NULL_TREE)
init = get_nsdmi (member, /*ctor*/true, tf_warning_or_error);
if (init == error_mark_node)
return;
/* Effective C++ rule 12 requires that all data members be
initialized. */
if (warn_ecpp && init == NULL_TREE && TREE_CODE (type) != ARRAY_TYPE)
warning_at (DECL_SOURCE_LOCATION (current_function_decl), OPT_Weffc__,
"%qD should be initialized in the member initialization list",
member);
/* Get an lvalue for the data member. */
decl = build_class_member_access_expr (current_class_ref, member,
/*access_path=*/NULL_TREE,
/*preserve_reference=*/true,
tf_warning_or_error);
if (decl == error_mark_node)
return;
if (warn_init_self && init && TREE_CODE (init) == TREE_LIST
&& TREE_CHAIN (init) == NULL_TREE)
{
tree val = TREE_VALUE (init);
/* Handle references. */
if (REFERENCE_REF_P (val))
val = TREE_OPERAND (val, 0);
if (TREE_CODE (val) == COMPONENT_REF && TREE_OPERAND (val, 1) == member
&& TREE_OPERAND (val, 0) == current_class_ref)
warning_at (DECL_SOURCE_LOCATION (current_function_decl),
OPT_Winit_self, "%qD is initialized with itself",
member);
}
if (array_of_unknown_bound_p (type))
{
maybe_reject_flexarray_init (member, init);
return;
}
if (init && TREE_CODE (init) == TREE_LIST)
{
/* A(): a{e} */
if (DIRECT_LIST_INIT_P (TREE_VALUE (init)))
init = build_x_compound_expr_from_list (init, ELK_MEM_INIT,
tf_warning_or_error);
/* We are trying to initialize an array from a ()-list. If we
should attempt to do so, conjure up a CONSTRUCTOR. */
else if (TREE_CODE (type) == ARRAY_TYPE
/* P0960 is a C++20 feature. */
&& cxx_dialect >= cxx20)
init = do_aggregate_paren_init (init, type);
else if (!CLASS_TYPE_P (type))
init = build_x_compound_expr_from_list (init, ELK_MEM_INIT,
tf_warning_or_error);
/* If we're initializing a class from a ()-list, leave the TREE_LIST
alone: we might call an appropriate constructor, or (in C++20)
do aggregate-initialization. */
}
if (init == void_type_node)
{
/* mem() means value-initialization. */
if (TREE_CODE (type) == ARRAY_TYPE)
{
init = build_vec_init_expr (type, init, tf_warning_or_error);
init = build2 (INIT_EXPR, type, decl, init);
finish_expr_stmt (init);
}
else
{
tree value = build_value_init (type, tf_warning_or_error);
if (value == error_mark_node)
return;
init = build2 (INIT_EXPR, type, decl, value);
finish_expr_stmt (init);
}
}
/* Deal with this here, as we will get confused if we try to call the
assignment op for an anonymous union. This can happen in a
synthesized copy constructor. */
else if (ANON_AGGR_TYPE_P (type))
{
if (init)
{
init = build2 (INIT_EXPR, type, decl, TREE_VALUE (init));
finish_expr_stmt (init);
}
}
else if (init
&& (TYPE_REF_P (type)
|| (TREE_CODE (init) == CONSTRUCTOR
&& (CP_AGGREGATE_TYPE_P (type)
|| is_std_init_list (type)))))
{
/* With references and list-initialization, we need to deal with
extending temporary lifetimes. 12.2p5: "A temporary bound to a
reference member in a constructor’s ctor-initializer (12.6.2)
persists until the constructor exits." */
unsigned i; tree t;
releasing_vec cleanups;
if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init), type))
{
if (BRACE_ENCLOSED_INITIALIZER_P (init)
&& CP_AGGREGATE_TYPE_P (type))
init = reshape_init (type, init, tf_warning_or_error);
init = digest_init (type, init, tf_warning_or_error);
}
if (init == error_mark_node)
return;
if (is_empty_field (member)
&& !TREE_SIDE_EFFECTS (init))
/* Don't add trivial initialization of an empty base/field, as they
might not be ordered the way the back-end expects. */
return;
/* A FIELD_DECL doesn't really have a suitable lifetime, but
make_temporary_var_for_ref_to_temp will treat it as automatic and
set_up_extended_ref_temp wants to use the decl in a warning. */
init = extend_ref_init_temps (member, init, &cleanups);
if (TREE_CODE (type) == ARRAY_TYPE
&& TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (type)))
init = build_vec_init_expr (type, init, tf_warning_or_error);
init = build2 (INIT_EXPR, type, decl, init);
finish_expr_stmt (init);
FOR_EACH_VEC_ELT (*cleanups, i, t)
push_cleanup (decl, t, false);
}
else if (type_build_ctor_call (type)
|| (init && CLASS_TYPE_P (strip_array_types (type))))
{
if (TREE_CODE (type) == ARRAY_TYPE)
{
if (init == NULL_TREE
|| same_type_ignoring_top_level_qualifiers_p (type,
TREE_TYPE (init)))
{
if (TYPE_DOMAIN (type) && TYPE_MAX_VALUE (TYPE_DOMAIN (type)))
{
/* Initialize the array only if it's not a flexible
array member (i.e., if it has an upper bound). */
init = build_vec_init_expr (type, init, tf_warning_or_error);
init = build2 (INIT_EXPR, type, decl, init);
finish_expr_stmt (init);
}
}
else
error ("invalid initializer for array member %q#D", member);
}
else
{
int flags = LOOKUP_NORMAL;
if (DECL_DEFAULTED_FN (current_function_decl))
flags |= LOOKUP_DEFAULTED;
if (CP_TYPE_CONST_P (type)
&& init == NULL_TREE
&& default_init_uninitialized_part (type))
{
/* TYPE_NEEDS_CONSTRUCTING can be set just because we have a
vtable; still give this diagnostic. */
auto_diagnostic_group d;
if (permerror (DECL_SOURCE_LOCATION (current_function_decl),
"uninitialized const member in %q#T", type))
inform (DECL_SOURCE_LOCATION (member),
"%q#D should be initialized", member );
}
finish_expr_stmt (build_aggr_init (decl, init, flags,
tf_warning_or_error));
}
}
else
{
if (init == NULL_TREE)
{
tree core_type;
/* member traversal: note it leaves init NULL */
if (TYPE_REF_P (type))
{
auto_diagnostic_group d;
if (permerror (DECL_SOURCE_LOCATION (current_function_decl),
"uninitialized reference member in %q#T", type))
inform (DECL_SOURCE_LOCATION (member),
"%q#D should be initialized", member);
}
else if (CP_TYPE_CONST_P (type))
{
auto_diagnostic_group d;
if (permerror (DECL_SOURCE_LOCATION (current_function_decl),
"uninitialized const member in %q#T", type))
inform (DECL_SOURCE_LOCATION (member),
"%q#D should be initialized", member );
}
core_type = strip_array_types (type);
if (CLASS_TYPE_P (core_type)
&& (CLASSTYPE_READONLY_FIELDS_NEED_INIT (core_type)
|| CLASSTYPE_REF_FIELDS_NEED_INIT (core_type)))
diagnose_uninitialized_cst_or_ref_member (core_type,
/*using_new=*/false,
/*complain=*/true);
}
maybe_warn_list_ctor (member, init);
if (init)
finish_expr_stmt (cp_build_modify_expr (input_location, decl,
INIT_EXPR, init,
tf_warning_or_error));
}
if (type_build_dtor_call (type))
{
tree expr;
expr = build_class_member_access_expr (current_class_ref, member,
/*access_path=*/NULL_TREE,
/*preserve_reference=*/false,
tf_warning_or_error);
expr = build_delete (input_location,
type, expr, sfk_complete_destructor,
LOOKUP_NONVIRTUAL|LOOKUP_DESTRUCTOR, 0,
tf_warning_or_error);
if (expr != error_mark_node
&& TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
finish_eh_cleanup (expr);
}
}
/* Returns a TREE_LIST containing (as the TREE_PURPOSE of each node) all
the FIELD_DECLs on the TYPE_FIELDS list for T, in reverse order. */
static tree
build_field_list (tree t, tree list, int *uses_unions_or_anon_p)
{
tree fields;
/* Note whether or not T is a union. */
if (TREE_CODE (t) == UNION_TYPE)
*uses_unions_or_anon_p = 1;
for (fields = TYPE_FIELDS (t); fields; fields = DECL_CHAIN (fields))
{
tree fieldtype;
/* Skip CONST_DECLs for enumeration constants and so forth. */
if (TREE_CODE (fields) != FIELD_DECL || DECL_ARTIFICIAL (fields))
continue;
fieldtype = TREE_TYPE (fields);
/* For an anonymous struct or union, we must recursively
consider the fields of the anonymous type. They can be
directly initialized from the constructor. */
if (ANON_AGGR_TYPE_P (fieldtype))
{
/* Add this field itself. Synthesized copy constructors
initialize the entire aggregate. */
list = tree_cons (fields, NULL_TREE, list);
/* And now add the fields in the anonymous aggregate. */
list = build_field_list (fieldtype, list, uses_unions_or_anon_p);
*uses_unions_or_anon_p = 1;
}
/* Add this field. */
else if (DECL_NAME (fields))
list = tree_cons (fields, NULL_TREE, list);
}
return list;
}
/* Return the innermost aggregate scope for FIELD, whether that is
the enclosing class or an anonymous aggregate within it. */
static tree
innermost_aggr_scope (tree field)
{
if (ANON_AGGR_TYPE_P (TREE_TYPE (field)))
return TREE_TYPE (field);
else
return DECL_CONTEXT (field);
}
/* The MEM_INITS are a TREE_LIST. The TREE_PURPOSE of each list gives
a FIELD_DECL or BINFO in T that needs initialization. The
TREE_VALUE gives the initializer, or list of initializer arguments.
Return a TREE_LIST containing all of the initializations required
for T, in the order in which they should be performed. The output
list has the same format as the input. */
static tree
sort_mem_initializers (tree t, tree mem_inits)
{
tree init;
tree base, binfo, base_binfo;
tree sorted_inits;
tree next_subobject;
vec<tree, va_gc> *vbases;
int i;
int uses_unions_or_anon_p = 0;
/* Build up a list of initializations. The TREE_PURPOSE of entry
will be the subobject (a FIELD_DECL or BINFO) to initialize. The
TREE_VALUE will be the constructor arguments, or NULL if no
explicit initialization was provided. */
sorted_inits = NULL_TREE;
/* Process the virtual bases. */
for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
vec_safe_iterate (vbases, i, &base); i++)
sorted_inits = tree_cons (base, NULL_TREE, sorted_inits);
/* Process the direct bases. */
for (binfo = TYPE_BINFO (t), i = 0;
BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
if (!BINFO_VIRTUAL_P (base_binfo))
sorted_inits = tree_cons (base_binfo, NULL_TREE, sorted_inits);
/* Process the non-static data members. */
sorted_inits = build_field_list (t, sorted_inits, &uses_unions_or_anon_p);
/* Reverse the entire list of initializations, so that they are in
the order that they will actually be performed. */
sorted_inits = nreverse (sorted_inits);
/* If the user presented the initializers in an order different from
that in which they will actually occur, we issue a warning. Keep
track of the next subobject which can be explicitly initialized
without issuing a warning. */
next_subobject = sorted_inits;
/* Go through the explicit initializers, filling in TREE_PURPOSE in
the SORTED_INITS. */
for (init = mem_inits; init; init = TREE_CHAIN (init))
{
tree subobject;
tree subobject_init;
subobject = TREE_PURPOSE (init);
/* If the explicit initializers are in sorted order, then
SUBOBJECT will be NEXT_SUBOBJECT, or something following
it. */
for (subobject_init = next_subobject;
subobject_init;
subobject_init = TREE_CHAIN (subobject_init))
if (TREE_PURPOSE (subobject_init) == subobject)
break;
/* Issue a warning if the explicit initializer order does not
match that which will actually occur.
??? Are all these on the correct lines? */
if (warn_reorder && !subobject_init)
{
if (TREE_CODE (TREE_PURPOSE (next_subobject)) == FIELD_DECL)
warning_at (DECL_SOURCE_LOCATION (TREE_PURPOSE (next_subobject)),
OPT_Wreorder, "%qD will be initialized after",
TREE_PURPOSE (next_subobject));
else
warning (OPT_Wreorder, "base %qT will be initialized after",
TREE_PURPOSE (next_subobject));
if (TREE_CODE (subobject) == FIELD_DECL)
warning_at (DECL_SOURCE_LOCATION (subobject),
OPT_Wreorder, " %q#D", subobject);
else
warning (OPT_Wreorder, " base %qT", subobject);
warning_at (DECL_SOURCE_LOCATION (current_function_decl),
OPT_Wreorder, " when initialized here");
}
/* Look again, from the beginning of the list. */
if (!subobject_init)
{
subobject_init = sorted_inits;
while (TREE_PURPOSE (subobject_init) != subobject)
subobject_init = TREE_CHAIN (subobject_init);
}
/* It is invalid to initialize the same subobject more than
once. */
if (TREE_VALUE (subobject_init))
{
if (TREE_CODE (subobject) == FIELD_DECL)
error_at (DECL_SOURCE_LOCATION (current_function_decl),
"multiple initializations given for %qD",
subobject);
else
error_at (DECL_SOURCE_LOCATION (current_function_decl),
"multiple initializations given for base %qT",
subobject);
}
/* Record the initialization. */
TREE_VALUE (subobject_init) = TREE_VALUE (init);
/* Carry over the dummy TREE_TYPE node containing the source location. */
TREE_TYPE (subobject_init) = TREE_TYPE (init);
next_subobject = subobject_init;
}
/* [class.base.init]
If a ctor-initializer specifies more than one mem-initializer for
multiple members of the same union (including members of
anonymous unions), the ctor-initializer is ill-formed.
Here we also splice out uninitialized union members. */
if (uses_unions_or_anon_p)
{
tree *last_p = NULL;
tree *p;
for (p = &sorted_inits; *p; )
{
tree field;
tree ctx;
init = *p;
field = TREE_PURPOSE (init);
/* Skip base classes. */
if (TREE_CODE (field) != FIELD_DECL)
goto next;
/* If this is an anonymous aggregate with no explicit initializer,
splice it out. */
if (!TREE_VALUE (init) && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
goto splice;
/* See if this field is a member of a union, or a member of a
structure contained in a union, etc. */
ctx = innermost_aggr_scope (field);
/* If this field is not a member of a union, skip it. */
if (TREE_CODE (ctx) != UNION_TYPE
&& !ANON_AGGR_TYPE_P (ctx))
goto next;
/* If this union member has no explicit initializer and no NSDMI,
splice it out. */
if (TREE_VALUE (init) || DECL_INITIAL (field))
/* OK. */;
else
goto splice;
/* It's only an error if we have two initializers for the same
union type. */
if (!last_p)
{
last_p = p;
goto next;
}
/* See if LAST_FIELD and the field initialized by INIT are
members of the same union (or the union itself). If so, there's
a problem, unless they're actually members of the same structure
which is itself a member of a union. For example, given:
union { struct { int i; int j; }; };
initializing both `i' and `j' makes sense. */
ctx = common_enclosing_class
(innermost_aggr_scope (field),
innermost_aggr_scope (TREE_PURPOSE (*last_p)));
if (ctx && (TREE_CODE (ctx) == UNION_TYPE
|| ctx == TREE_TYPE (TREE_PURPOSE (*last_p))))
{
/* A mem-initializer hides an NSDMI. */
if (TREE_VALUE (init) && !TREE_VALUE (*last_p))
*last_p = TREE_CHAIN (*last_p);
else if (TREE_VALUE (*last_p) && !TREE_VALUE (init))
goto splice;
else
{
error_at (DECL_SOURCE_LOCATION (current_function_decl),
"initializations for multiple members of %qT",
ctx);
goto splice;
}
}
last_p = p;
next:
p = &TREE_CHAIN (*p);
continue;
splice:
*p = TREE_CHAIN (*p);
continue;
}
}
return sorted_inits;
}
/* Callback for cp_walk_tree to mark all PARM_DECLs in a tree as read. */
static tree
mark_exp_read_r (tree *tp, int *, void *)
{
tree t = *tp;
if (TREE_CODE (t) == PARM_DECL)
mark_exp_read (t);
return NULL_TREE;
}
/* Initialize all bases and members of CURRENT_CLASS_TYPE. MEM_INITS
is a TREE_LIST giving the explicit mem-initializer-list for the
constructor. The TREE_PURPOSE of each entry is a subobject (a
FIELD_DECL or a BINFO) of the CURRENT_CLASS_TYPE. The TREE_VALUE
is a TREE_LIST giving the arguments to the constructor or
void_type_node for an empty list of arguments. */
void
emit_mem_initializers (tree mem_inits)
{
int flags = LOOKUP_NORMAL;
/* We will already have issued an error message about the fact that
the type is incomplete. */
if (!COMPLETE_TYPE_P (current_class_type))
return;
if (mem_inits
&& TYPE_P (TREE_PURPOSE (mem_inits))
&& same_type_p (TREE_PURPOSE (mem_inits), current_class_type))
{
/* Delegating constructor. */
gcc_assert (TREE_CHAIN (mem_inits) == NULL_TREE);
perform_target_ctor (TREE_VALUE (mem_inits));
return;
}
if (DECL_DEFAULTED_FN (current_function_decl)
&& ! DECL_INHERITED_CTOR (current_function_decl))
flags |= LOOKUP_DEFAULTED;
/* Sort the mem-initializers into the order in which the
initializations should be performed. */
mem_inits = sort_mem_initializers (current_class_type, mem_inits);
in_base_initializer = 1;
/* Initialize base classes. */
for (; (mem_inits
&& TREE_CODE (TREE_PURPOSE (mem_inits)) != FIELD_DECL);
mem_inits = TREE_CHAIN (mem_inits))
{
tree subobject = TREE_PURPOSE (mem_inits);
tree arguments = TREE_VALUE (mem_inits);
/* We already have issued an error message. */
if (arguments == error_mark_node)
continue;
/* Suppress access control when calling the inherited ctor. */
bool inherited_base = (DECL_INHERITED_CTOR (current_function_decl)
&& flag_new_inheriting_ctors
&& arguments);
if (inherited_base)
push_deferring_access_checks (dk_deferred);
if (arguments == NULL_TREE)
{
/* If these initializations are taking place in a copy constructor,
the base class should probably be explicitly initialized if there
is a user-defined constructor in the base class (other than the
default constructor, which will be called anyway). */
if (extra_warnings
&& DECL_COPY_CONSTRUCTOR_P (current_function_decl)
&& type_has_user_nondefault_constructor (BINFO_TYPE (subobject)))
warning_at (DECL_SOURCE_LOCATION (current_function_decl),
OPT_Wextra, "base class %q#T should be explicitly "
"initialized in the copy constructor",
BINFO_TYPE (subobject));
}
/* Initialize the base. */
if (!BINFO_VIRTUAL_P (subobject))
{
tree base_addr;
base_addr = build_base_path (PLUS_EXPR, current_class_ptr,
subobject, 1, tf_warning_or_error);
expand_aggr_init_1 (subobject, NULL_TREE,
cp_build_fold_indirect_ref (base_addr),
arguments,
flags,
tf_warning_or_error);
expand_cleanup_for_base (subobject, NULL_TREE);
}
else if (!ABSTRACT_CLASS_TYPE_P (current_class_type))
/* C++14 DR1658 Means we do not have to construct vbases of
abstract classes. */
construct_virtual_base (subobject, arguments);
else
/* When not constructing vbases of abstract classes, at least mark
the arguments expressions as read to avoid
-Wunused-but-set-parameter false positives. */
cp_walk_tree (&arguments, mark_exp_read_r, NULL, NULL);
if (inherited_base)
pop_deferring_access_checks ();
}
in_base_initializer = 0;
/* Initialize the vptrs. */
initialize_vtbl_ptrs (current_class_ptr);
/* Initialize the data members. */
while (mem_inits)
{
/* If this initializer was explicitly provided, then the dummy TREE_TYPE
node contains the source location. */
iloc_sentinel ils (EXPR_LOCATION (TREE_TYPE (mem_inits)));
perform_member_init (TREE_PURPOSE (mem_inits),
TREE_VALUE (mem_inits));
mem_inits = TREE_CHAIN (mem_inits);
}
}
/* Returns the address of the vtable (i.e., the value that should be
assigned to the vptr) for BINFO. */
tree
build_vtbl_address (tree binfo)
{
tree binfo_for = binfo;
tree vtbl;
if (BINFO_VPTR_INDEX (binfo) && BINFO_VIRTUAL_P (binfo))
/* If this is a virtual primary base, then the vtable we want to store
is that for the base this is being used as the primary base of. We
can't simply skip the initialization, because we may be expanding the
inits of a subobject constructor where the virtual base layout
can be different. */
while (BINFO_PRIMARY_P (binfo_for))
binfo_for = BINFO_INHERITANCE_CHAIN (binfo_for);
/* Figure out what vtable BINFO's vtable is based on, and mark it as
used. */
vtbl = get_vtbl_decl_for_binfo (binfo_for);
TREE_USED (vtbl) = true;
/* Now compute the address to use when initializing the vptr. */
vtbl = unshare_expr (BINFO_VTABLE (binfo_for));
if (VAR_P (vtbl))
vtbl = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (vtbl)), vtbl);
return vtbl;
}
/* This code sets up the virtual function tables appropriate for
the pointer DECL. It is a one-ply initialization.
BINFO is the exact type that DECL is supposed to be. In
multiple inheritance, this might mean "C's A" if C : A, B. */
static void
expand_virtual_init (tree binfo, tree decl)
{
tree vtbl, vtbl_ptr;
tree vtt_index;
/* Compute the initializer for vptr. */
vtbl = build_vtbl_address (binfo);
/* We may get this vptr from a VTT, if this is a subobject
constructor or subobject destructor. */
vtt_index = BINFO_VPTR_INDEX (binfo);
if (vtt_index)
{
tree vtbl2;
tree vtt_parm;
/* Compute the value to use, when there's a VTT. */
vtt_parm = current_vtt_parm;
vtbl2 = fold_build_pointer_plus (vtt_parm, vtt_index);
vtbl2 = cp_build_fold_indirect_ref (vtbl2);
vtbl2 = convert (TREE_TYPE (vtbl), vtbl2);
/* The actual initializer is the VTT value only in the subobject
constructor. In maybe_clone_body we'll substitute NULL for
the vtt_parm in the case of the non-subobject constructor. */
vtbl = build_if_in_charge (vtbl, vtbl2);
}
/* Compute the location of the vtpr. */
vtbl_ptr = build_vfield_ref (cp_build_fold_indirect_ref (decl),
TREE_TYPE (binfo));
gcc_assert (vtbl_ptr != error_mark_node);
/* Assign the vtable to the vptr. */
vtbl = convert_force (TREE_TYPE (vtbl_ptr), vtbl, 0, tf_warning_or_error);
finish_expr_stmt (cp_build_modify_expr (input_location, vtbl_ptr, NOP_EXPR,
vtbl, tf_warning_or_error));
}
/* If an exception is thrown in a constructor, those base classes already
constructed must be destroyed. This function creates the cleanup
for BINFO, which has just been constructed. If FLAG is non-NULL,
it is a DECL which is nonzero when this base needs to be
destroyed. */
static void
expand_cleanup_for_base (tree binfo, tree flag)
{
tree expr;
if (!type_build_dtor_call (BINFO_TYPE (binfo)))
return;
/* Call the destructor. */
expr = build_special_member_call (current_class_ref,
base_dtor_identifier,
NULL,
binfo,
LOOKUP_NORMAL | LOOKUP_NONVIRTUAL,
tf_warning_or_error);
if (TYPE_HAS_TRIVIAL_DESTRUCTOR (BINFO_TYPE (binfo)))
return;
if (flag)
expr = fold_build3_loc (input_location,
COND_EXPR, void_type_node,
c_common_truthvalue_conversion (input_location, flag),
expr, integer_zero_node);
finish_eh_cleanup (expr);
}
/* Construct the virtual base-class VBASE passing the ARGUMENTS to its
constructor. */
static void
construct_virtual_base (tree vbase, tree arguments)
{
tree inner_if_stmt;
tree exp;
tree flag;
/* If there are virtual base classes with destructors, we need to
emit cleanups to destroy them if an exception is thrown during
the construction process. These exception regions (i.e., the
period during which the cleanups must occur) begin from the time
the construction is complete to the end of the function. If we
create a conditional block in which to initialize the
base-classes, then the cleanup region for the virtual base begins
inside a block, and ends outside of that block. This situation
confuses the sjlj exception-handling code. Therefore, we do not
create a single conditional block, but one for each
initialization. (That way the cleanup regions always begin
in the outer block.) We trust the back end to figure out
that the FLAG will not change across initializations, and
avoid doing multiple tests. */
flag = DECL_CHAIN (DECL_ARGUMENTS (current_function_decl));
inner_if_stmt = begin_if_stmt ();
finish_if_stmt_cond (flag, inner_if_stmt);
/* Compute the location of the virtual base. If we're
constructing virtual bases, then we must be the most derived
class. Therefore, we don't have to look up the virtual base;
we already know where it is. */
exp = convert_to_base_statically (current_class_ref, vbase);
expand_aggr_init_1 (vbase, current_class_ref, exp, arguments,
0, tf_warning_or_error);
finish_then_clause (inner_if_stmt);
finish_if_stmt (inner_if_stmt);
expand_cleanup_for_base (vbase, flag);
}
/* Find the context in which this FIELD can be initialized. */
static tree
initializing_context (tree field)
{
tree t = DECL_CONTEXT (field);
/* Anonymous union members can be initialized in the first enclosing
non-anonymous union context. */
while (t && ANON_AGGR_TYPE_P (t))
t = TYPE_CONTEXT (t);
return t;
}
/* Function to give error message if member initialization specification
is erroneous. FIELD is the member we decided to initialize.
TYPE is the type for which the initialization is being performed.
FIELD must be a member of TYPE.
MEMBER_NAME is the name of the member. */
static int
member_init_ok_or_else (tree field, tree type, tree member_name)
{
if (field == error_mark_node)
return 0;
if (!field)
{
error ("class %qT does not have any field named %qD", type,
member_name);
return 0;
}
if (VAR_P (field))
{
error ("%q#D is a static data member; it can only be "
"initialized at its definition",
field);
return 0;
}
if (TREE_CODE (field) != FIELD_DECL)
{
error ("%q#D is not a non-static data member of %qT",
field, type);
return 0;
}
if (initializing_context (field) != type)
{
error ("class %qT does not have any field named %qD", type,
member_name);
return 0;
}
return 1;
}
/* NAME is a FIELD_DECL, an IDENTIFIER_NODE which names a field, or it
is a _TYPE node or TYPE_DECL which names a base for that type.
Check the validity of NAME, and return either the base _TYPE, base
binfo, or the FIELD_DECL of the member. If NAME is invalid, return
NULL_TREE and issue a diagnostic.
An old style unnamed direct single base construction is permitted,
where NAME is NULL. */
tree
expand_member_init (tree name)
{
tree basetype;
tree field;
if (!current_class_ref)
return NULL_TREE;
if (!name)
{
/* This is an obsolete unnamed base class initializer. The
parser will already have warned about its use. */
switch (BINFO_N_BASE_BINFOS (TYPE_BINFO (current_class_type)))
{
case 0:
error ("unnamed initializer for %qT, which has no base classes",
current_class_type);
return NULL_TREE;
case 1:
basetype = BINFO_TYPE
(BINFO_BASE_BINFO (TYPE_BINFO (current_class_type), 0));
break;
default:
error ("unnamed initializer for %qT, which uses multiple inheritance",
current_class_type);
return NULL_TREE;
}
}
else if (TYPE_P (name))
{
basetype = TYPE_MAIN_VARIANT (name);
name = TYPE_NAME (name);
}
else if (TREE_CODE (name) == TYPE_DECL)
basetype = TYPE_MAIN_VARIANT (TREE_TYPE (name));
else
basetype = NULL_TREE;
if (basetype)
{
tree class_binfo;
tree direct_binfo;
tree virtual_binfo;
int i;
if (current_template_parms
|| same_type_p (basetype, current_class_type))
return basetype;
class_binfo = TYPE_BINFO (current_class_type);
direct_binfo = NULL_TREE;
virtual_binfo = NULL_TREE;
/* Look for a direct base. */
for (i = 0; BINFO_BASE_ITERATE (class_binfo, i, direct_binfo); ++i)
if (SAME_BINFO_TYPE_P (BINFO_TYPE (direct_binfo), basetype))
break;
/* Look for a virtual base -- unless the direct base is itself
virtual. */
if (!direct_binfo || !BINFO_VIRTUAL_P (direct_binfo))
virtual_binfo = binfo_for_vbase (basetype, current_class_type);
/* [class.base.init]
If a mem-initializer-id is ambiguous because it designates
both a direct non-virtual base class and an inherited virtual
base class, the mem-initializer is ill-formed. */
if (direct_binfo && virtual_binfo)
{
error ("%qD is both a direct base and an indirect virtual base",
basetype);
return NULL_TREE;
}
if (!direct_binfo && !virtual_binfo)
{
if (CLASSTYPE_VBASECLASSES (current_class_type))
error ("type %qT is not a direct or virtual base of %qT",
basetype, current_class_type);
else
error ("type %qT is not a direct base of %qT",
basetype, current_class_type);
return NULL_TREE;
}
return direct_binfo ? direct_binfo : virtual_binfo;
}
else
{
if (identifier_p (name))
field = lookup_field (current_class_type, name, 1, false);
else
field = name;
if (member_init_ok_or_else (field, current_class_type, name))
return field;
}
return NULL_TREE;
}
/* This is like `expand_member_init', only it stores one aggregate
value into another.
INIT comes in two flavors: it is either a value which
is to be stored in EXP, or it is a parameter list
to go to a constructor, which will operate on EXP.
If INIT is not a parameter list for a constructor, then set
LOOKUP_ONLYCONVERTING.
If FLAGS is LOOKUP_ONLYCONVERTING then it is the = init form of
the initializer, if FLAGS is 0, then it is the (init) form.
If `init' is a CONSTRUCTOR, then we emit a warning message,
explaining that such initializations are invalid.
If INIT resolves to a CALL_EXPR which happens to return
something of the type we are looking for, then we know
that we can safely use that call to perform the
initialization.
The virtual function table pointer cannot be set up here, because
we do not really know its type.
This never calls operator=().
When initializing, nothing is CONST.
A default copy constructor may have to be used to perform the
initialization.
A constructor or a conversion operator may have to be used to
perform the initialization, but not both, as it would be ambiguous. */
tree
build_aggr_init (tree exp, tree init, int flags, tsubst_flags_t complain)
{
tree stmt_expr;
tree compound_stmt;
int destroy_temps;
tree type = TREE_TYPE (exp);
int was_const = TREE_READONLY (exp);
int was_volatile = TREE_THIS_VOLATILE (exp);
int is_global;
if (init == error_mark_node)
return error_mark_node;
location_t init_loc = (init
? cp_expr_loc_or_input_loc (init)
: location_of (exp));
TREE_READONLY (exp) = 0;
TREE_THIS_VOLATILE (exp) = 0;
if (TREE_CODE (type) == ARRAY_TYPE)
{
tree itype = init ? TREE_TYPE (init) : NULL_TREE;
int from_array = 0;
if (VAR_P (exp) && DECL_DECOMPOSITION_P (exp))
{
from_array = 1;
init = mark_rvalue_use (init);
if (init
&& DECL_P (tree_strip_any_location_wrapper (init))
&& !(flags & LOOKUP_ONLYCONVERTING))
{
/* Wrap the initializer in a CONSTRUCTOR so that build_vec_init
recognizes it as direct-initialization. */
init = build_constructor_single (init_list_type_node,
NULL_TREE, init);
CONSTRUCTOR_IS_DIRECT_INIT (init) = true;
}
}
else
{
/* Must arrange to initialize each element of EXP
from elements of INIT. */
if (cv_qualified_p (type))
TREE_TYPE (exp) = cv_unqualified (type);
if (itype && cv_qualified_p (itype))
TREE_TYPE (init) = cv_unqualified (itype);
from_array = (itype && same_type_p (TREE_TYPE (init),
TREE_TYPE (exp)));
if (init && !BRACE_ENCLOSED_INITIALIZER_P (init)
&& (!from_array
|| (TREE_CODE (init) != CONSTRUCTOR
/* Can happen, eg, handling the compound-literals
extension (ext/complit12.C). */
&& TREE_CODE (init) != TARGET_EXPR)))
{
if (complain & tf_error)
error_at (init_loc, "array must be initialized "
"with a brace-enclosed initializer");
return error_mark_node;
}
}
stmt_expr = build_vec_init (exp, NULL_TREE, init,
/*explicit_value_init_p=*/false,
from_array,
complain);
TREE_READONLY (exp) = was_const;
TREE_THIS_VOLATILE (exp) = was_volatile;
TREE_TYPE (exp) = type;
/* Restore the type of init unless it was used directly. */
if (init && TREE_CODE (stmt_expr) != INIT_EXPR)
TREE_TYPE (init) = itype;
return stmt_expr;
}
if (init && init != void_type_node
&& TREE_CODE (init) != TREE_LIST
&& !(TREE_CODE (init) == TARGET_EXPR
&& TARGET_EXPR_DIRECT_INIT_P (init))
&& !DIRECT_LIST_INIT_P (init))
flags |= LOOKUP_ONLYCONVERTING;
is_global = begin_init_stmts (&stmt_expr, &compound_stmt);
destroy_temps = stmts_are_full_exprs_p ();
current_stmt_tree ()->stmts_are_full_exprs_p = 0;
bool ok = expand_aggr_init_1 (TYPE_BINFO (type), exp, exp,
init, LOOKUP_NORMAL|flags, complain);
stmt_expr = finish_init_stmts (is_global, stmt_expr, compound_stmt);
current_stmt_tree ()->stmts_are_full_exprs_p = destroy_temps;
TREE_READONLY (exp) = was_const;
TREE_THIS_VOLATILE (exp) = was_volatile;
if (!ok)
return error_mark_node;
if ((VAR_P (exp) || TREE_CODE (exp) == PARM_DECL)
&& TREE_SIDE_EFFECTS (stmt_expr)
&& !lookup_attribute ("warn_unused", TYPE_ATTRIBUTES (type)))
/* Just know that we've seen something for this node. */
TREE_USED (exp) = 1;
return stmt_expr;
}
static bool
expand_default_init (tree binfo, tree true_exp, tree exp, tree init, int flags,
tsubst_flags_t complain)
{
tree type = TREE_TYPE (exp);
/* It fails because there may not be a constructor which takes
its own type as the first (or only parameter), but which does
take other types via a conversion. So, if the thing initializing
the expression is a unit element of type X, first try X(X&),
followed by initialization by X. If neither of these work
out, then look hard. */
tree rval;
vec<tree, va_gc> *parms;
/* If we have direct-initialization from an initializer list, pull
it out of the TREE_LIST so the code below can see it. */
if (init && TREE_CODE (init) == TREE_LIST
&& DIRECT_LIST_INIT_P (TREE_VALUE (init)))
{
gcc_checking_assert ((flags & LOOKUP_ONLYCONVERTING) == 0
&& TREE_CHAIN (init) == NULL_TREE);
init = TREE_VALUE (init);
/* Only call reshape_init if it has not been called earlier
by the callers. */
if (BRACE_ENCLOSED_INITIALIZER_P (init) && CP_AGGREGATE_TYPE_P (type))
init = reshape_init (type, init, complain);
}
if (init && BRACE_ENCLOSED_INITIALIZER_P (init)
&& CP_AGGREGATE_TYPE_P (type))
/* A brace-enclosed initializer for an aggregate. In C++0x this can
happen for direct-initialization, too. */
init = digest_init (type, init, complain);
if (init == error_mark_node)
return false;
/* A CONSTRUCTOR of the target's type is a previously digested
initializer, whether that happened just above or in
cp_parser_late_parsing_nsdmi.
A TARGET_EXPR with TARGET_EXPR_DIRECT_INIT_P or TARGET_EXPR_LIST_INIT_P
set represents the whole initialization, so we shouldn't build up
another ctor call. */
if (init
&& (TREE_CODE (init) == CONSTRUCTOR
|| (TREE_CODE (init) == TARGET_EXPR
&& (TARGET_EXPR_DIRECT_INIT_P (init)
|| TARGET_EXPR_LIST_INIT_P (init))))
&& same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init), type))
{
/* Early initialization via a TARGET_EXPR only works for
complete objects. */
gcc_assert (TREE_CODE (init) == CONSTRUCTOR || true_exp == exp);
init = build2 (INIT_EXPR, TREE_TYPE (exp), exp, init);
TREE_SIDE_EFFECTS (init) = 1;
finish_expr_stmt (init);
return true;
}
if (init && TREE_CODE (init) != TREE_LIST
&& (flags & LOOKUP_ONLYCONVERTING)
&& !unsafe_return_slot_p (exp))
{
/* Base subobjects should only get direct-initialization. */
gcc_assert (true_exp == exp);
if (flags & DIRECT_BIND)
/* Do nothing. We hit this in two cases: Reference initialization,
where we aren't initializing a real variable, so we don't want
to run a new constructor; and catching an exception, where we
have already built up the constructor call so we could wrap it
in an exception region. */;
else
{
init = ocp_convert (type, init, CONV_IMPLICIT|CONV_FORCE_TEMP,
flags, complain | tf_no_cleanup);
if (init == error_mark_node)
return false;
}
if (TREE_CODE (init) == MUST_NOT_THROW_EXPR)
/* We need to protect the initialization of a catch parm with a
call to terminate(), which shows up as a MUST_NOT_THROW_EXPR
around the TARGET_EXPR for the copy constructor. See
initialize_handler_parm. */
{
TREE_OPERAND (init, 0) = build2 (INIT_EXPR, TREE_TYPE (exp), exp,
TREE_OPERAND (init, 0));
TREE_TYPE (init) = void_type_node;
}
else
init = build2 (INIT_EXPR, TREE_TYPE (exp), exp, init);
TREE_SIDE_EFFECTS (init) = 1;
finish_expr_stmt (init);
return true;
}
if (init == NULL_TREE)
parms = NULL;
else if (TREE_CODE (init) == TREE_LIST && !TREE_TYPE (init))
{
parms = make_tree_vector ();
for (; init != NULL_TREE; init = TREE_CHAIN (init))
vec_safe_push (parms, TREE_VALUE (init));
}
else
parms = make_tree_vector_single (init);
if (exp == current_class_ref && current_function_decl
&& DECL_HAS_IN_CHARGE_PARM_P (current_function_decl))
{
/* Delegating constructor. */
tree complete;
tree base;
tree elt; unsigned i;
/* Unshare the arguments for the second call. */
releasing_vec parms2;
FOR_EACH_VEC_SAFE_ELT (parms, i, elt)
{
elt = break_out_target_exprs (elt);
vec_safe_push (parms2, elt);
}
complete = build_special_member_call (exp, complete_ctor_identifier,
&parms2, binfo, flags,
complain);
complete = fold_build_cleanup_point_expr (void_type_node, complete);
base = build_special_member_call (exp, base_ctor_identifier,
&parms, binfo, flags,
complain);
base = fold_build_cleanup_point_expr (void_type_node, base);
if (complete == error_mark_node || base == error_mark_node)
return false;
rval = build_if_in_charge (complete, base);
}
else
{
tree ctor_name = (true_exp == exp
? complete_ctor_identifier : base_ctor_identifier);
rval = build_special_member_call (exp, ctor_name, &parms, binfo, flags,
complain);
if (rval == error_mark_node)
return false;
}
if (parms != NULL)
release_tree_vector (parms);
if (exp == true_exp && TREE_CODE (rval) == CALL_EXPR)
{
tree fn = get_callee_fndecl (rval);
if (fn && DECL_DECLARED_CONSTEXPR_P (fn))
{
tree e = maybe_constant_init (rval, exp);
if (TREE_CONSTANT (e))
rval = build2 (INIT_EXPR, type, exp, e);
}
}
/* FIXME put back convert_to_void? */
if (TREE_SIDE_EFFECTS (rval))
finish_expr_stmt (rval);
return true;
}
/* This function is responsible for initializing EXP with INIT
(if any). Returns true on success, false on failure.
BINFO is the binfo of the type for who we are performing the
initialization. For example, if W is a virtual base class of A and B,
and C : A, B.
If we are initializing B, then W must contain B's W vtable, whereas
were we initializing C, W must contain C's W vtable.
TRUE_EXP is nonzero if it is the true expression being initialized.
In this case, it may be EXP, or may just contain EXP. The reason we
need this is because if EXP is a base element of TRUE_EXP, we
don't necessarily know by looking at EXP where its virtual
baseclass fields should really be pointing. But we do know
from TRUE_EXP. In constructors, we don't know anything about
the value being initialized.
FLAGS is just passed to `build_new_method_call'. See that function
for its description. */
static bool
expand_aggr_init_1 (tree binfo, tree true_exp, tree exp, tree init, int flags,
tsubst_flags_t complain)
{
tree type = TREE_TYPE (exp);
gcc_assert (init != error_mark_node && type != error_mark_node);
gcc_assert (building_stmt_list_p ());
/* Use a function returning the desired type to initialize EXP for us.
If the function is a constructor, and its first argument is
NULL_TREE, know that it was meant for us--just slide exp on
in and expand the constructor. Constructors now come
as TARGET_EXPRs. */
if (init && VAR_P (exp)
&& COMPOUND_LITERAL_P (init))
{
vec<tree, va_gc> *cleanups = NULL;
/* If store_init_value returns NULL_TREE, the INIT has been
recorded as the DECL_INITIAL for EXP. That means there's
nothing more we have to do. */
init = store_init_value (exp, init, &cleanups, flags);
if (init)
finish_expr_stmt (init);
gcc_assert (!cleanups);
return true;
}
/* List-initialization from {} becomes value-initialization for non-aggregate
classes with default constructors. Handle this here when we're
initializing a base, so protected access works. */
if (exp != true_exp && init && TREE_CODE (init) == TREE_LIST)
{
tree elt = TREE_VALUE (init);
if (DIRECT_LIST_INIT_P (elt)
&& CONSTRUCTOR_ELTS (elt) == 0
&& CLASSTYPE_NON_AGGREGATE (type)
&& TYPE_HAS_DEFAULT_CONSTRUCTOR (type))
init = void_type_node;
}
/* If an explicit -- but empty -- initializer list was present,
that's value-initialization. */
if (init == void_type_node)
{
/* If the type has data but no user-provided default ctor, we need to zero
out the object. */
if (type_has_non_user_provided_default_constructor (type)
&& !is_really_empty_class (type, /*ignore_vptr*/true))
{
tree field_size = NULL_TREE;
if (exp != true_exp && CLASSTYPE_AS_BASE (type) != type)
/* Don't clobber already initialized virtual bases. */
field_size = TYPE_SIZE (CLASSTYPE_AS_BASE (type));
init = build_zero_init_1 (type, NULL_TREE, /*static_storage_p=*/false,
field_size);
init = build2 (INIT_EXPR, type, exp, init);
finish_expr_stmt (init);
}
/* If we don't need to mess with the constructor at all,
then we're done. */
if (! type_build_ctor_call (type))
return true;
/* Otherwise fall through and call the constructor. */
init = NULL_TREE;
}
/* We know that expand_default_init can handle everything we want
at this point. */
return expand_default_init (binfo, true_exp, exp, init, flags, complain);
}
/* Report an error if TYPE is not a user-defined, class type. If
OR_ELSE is nonzero, give an error message. */
int
is_class_type (tree type, int or_else)
{
if (type == error_mark_node)
return 0;
if (! CLASS_TYPE_P (type))
{
if (or_else)
error ("%qT is not a class type", type);
return 0;
}
return 1;
}
/* Build a reference to a member of an aggregate. This is not a C++
`&', but really something which can have its address taken, and
then act as a pointer to member, for example TYPE :: FIELD can have
its address taken by saying & TYPE :: FIELD. ADDRESS_P is true if
this expression is the operand of "&".
@@ Prints out lousy diagnostics for operator <typename>
@@ fields.
@@ This function should be rewritten and placed in search.c. */
tree
build_offset_ref (tree type, tree member, bool address_p,
tsubst_flags_t complain)
{
tree decl;
tree basebinfo = NULL_TREE;
/* class templates can come in as TEMPLATE_DECLs here. */
if (TREE_CODE (member) == TEMPLATE_DECL)
return member;
if (dependent_scope_p (type) || type_dependent_expression_p (member))
return build_qualified_name (NULL_TREE, type, member,
/*template_p=*/false);
gcc_assert (TYPE_P (type));
if (! is_class_type (type, 1))
return error_mark_node;
gcc_assert (DECL_P (member) || BASELINK_P (member));
/* Callers should call mark_used before this point. */
gcc_assert (!DECL_P (member) || TREE_USED (member));
type = TYPE_MAIN_VARIANT (type);
if (!COMPLETE_OR_OPEN_TYPE_P (complete_type (type)))
{
if (complain & tf_error)
error ("incomplete type %qT does not have member %qD", type, member);
return error_mark_node;
}
/* Entities other than non-static members need no further
processing. */
if (TREE_CODE (member) == TYPE_DECL)
return member;
if (VAR_P (member) || TREE_CODE (member) == CONST_DECL)
return convert_from_reference (member);
if (TREE_CODE (member) == FIELD_DECL && DECL_C_BIT_FIELD (member))
{
if (complain & tf_error)
error ("invalid pointer to bit-field %qD", member);
return error_mark_node;
}
/* Set up BASEBINFO for member lookup. */
decl = maybe_dummy_object (type, &basebinfo);
/* A lot of this logic is now handled in lookup_member. */
if (BASELINK_P (member))
{
/* Go from the TREE_BASELINK to the member function info. */
tree t = BASELINK_FUNCTIONS (member);
if (TREE_CODE (t) != TEMPLATE_ID_EXPR && !really_overloaded_fn (t))
{
/* Get rid of a potential OVERLOAD around it. */
t = OVL_FIRST (t);
/* Unique functions are handled easily. */
/* For non-static member of base class, we need a special rule
for access checking [class.protected]:
If the access is to form a pointer to member, the
nested-name-specifier shall name the derived class
(or any class derived from that class). */
bool ok;
if (address_p && DECL_P (t)
&& DECL_NONSTATIC_MEMBER_P (t))
ok = perform_or_defer_access_check (TYPE_BINFO (type), t, t,
complain);
else
ok = perform_or_defer_access_check (basebinfo, t, t,
complain);
if (!ok)
return error_mark_node;
if (DECL_STATIC_FUNCTION_P (t))
return member;
member = t;
}
else
TREE_TYPE (member) = unknown_type_node;
}
else if (address_p && TREE_CODE (member) == FIELD_DECL)
{
/* We need additional test besides the one in
check_accessibility_of_qualified_id in case it is
a pointer to non-static member. */
if (!perform_or_defer_access_check (TYPE_BINFO (type), member, member,
complain))
return error_mark_node;
}
if (!address_p)
{
/* If MEMBER is non-static, then the program has fallen afoul of
[expr.prim]:
An id-expression that denotes a non-static data member or
non-static member function of a class can only be used:
-- as part of a class member access (_expr.ref_) in which the
object-expression refers to the member's class or a class
derived from that class, or
-- to form a pointer to member (_expr.unary.op_), or
-- in the body of a non-static member function of that class or
of a class derived from that class (_class.mfct.non-static_), or
-- in a mem-initializer for a constructor for that class or for
a class derived from that class (_class.base.init_). */
if (DECL_NONSTATIC_MEMBER_FUNCTION_P (member))
{
/* Build a representation of the qualified name suitable
for use as the operand to "&" -- even though the "&" is
not actually present. */
member = build2 (OFFSET_REF, TREE_TYPE (member), decl, member);
/* In Microsoft mode, treat a non-static member function as if
it were a pointer-to-member. */
if (flag_ms_extensions)
{
PTRMEM_OK_P (member) = 1;
return cp_build_addr_expr (member, complain);
}
if (complain & tf_error)
error ("invalid use of non-static member function %qD",
TREE_OPERAND (member, 1));
return error_mark_node;
}
else if (TREE_CODE (member) == FIELD_DECL)
{
if (complain & tf_error)
error ("invalid use of non-static data member %qD", member);
return error_mark_node;
}
return member;
}
member = build2 (OFFSET_REF, TREE_TYPE (member), decl, member);
PTRMEM_OK_P (member) = 1;
return member;
}
/* If DECL is a scalar enumeration constant or variable with a
constant initializer, return the initializer (or, its initializers,
recursively); otherwise, return DECL. If STRICT_P, the
initializer is only returned if DECL is a
constant-expression. If RETURN_AGGREGATE_CST_OK_P, it is ok to
return an aggregate constant. If UNSHARE_P, return an unshared
copy of the initializer. */
static tree
constant_value_1 (tree decl, bool strict_p, bool return_aggregate_cst_ok_p,
bool unshare_p)
{
while (TREE_CODE (decl) == CONST_DECL
|| decl_constant_var_p (decl)
|| (!strict_p && VAR_P (decl)
&& CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (decl))))
{
tree init;
/* If DECL is a static data member in a template
specialization, we must instantiate it here. The
initializer for the static data member is not processed
until needed; we need it now. */
mark_used (decl, tf_none);
init = DECL_INITIAL (decl);
if (init == error_mark_node)
{
if (TREE_CODE (decl) == CONST_DECL
|| DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl))
/* Treat the error as a constant to avoid cascading errors on
excessively recursive template instantiation (c++/9335). */
return init;
else
return decl;
}
/* Initializers in templates are generally expanded during
instantiation, so before that for const int i(2)
INIT is a TREE_LIST with the actual initializer as
TREE_VALUE. */
if (processing_template_decl
&& init
&& TREE_CODE (init) == TREE_LIST
&& TREE_CHAIN (init) == NULL_TREE)
init = TREE_VALUE (init);
/* Instantiate a non-dependent initializer for user variables. We
mustn't do this for the temporary for an array compound literal;
trying to instatiate the initializer will keep creating new
temporaries until we crash. Probably it's not useful to do it for
other artificial variables, either. */
if (!DECL_ARTIFICIAL (decl))
init = instantiate_non_dependent_or_null (init);
if (!init
|| !TREE_TYPE (init)
|| !TREE_CONSTANT (init)
|| (!return_aggregate_cst_ok_p
/* Unless RETURN_AGGREGATE_CST_OK_P is true, do not
return an aggregate constant (of which string
literals are a special case), as we do not want
to make inadvertent copies of such entities, and
we must be sure that their addresses are the
same everywhere. */
&& (TREE_CODE (init) == CONSTRUCTOR
|| TREE_CODE (init) == STRING_CST)))
break;
/* Don't return a CONSTRUCTOR for a variable with partial run-time
initialization, since it doesn't represent the entire value.
Similarly for VECTOR_CSTs created by cp_folding those
CONSTRUCTORs. */
if ((TREE_CODE (init) == CONSTRUCTOR
|| TREE_CODE (init) == VECTOR_CST)
&& !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl))
break;
/* If the variable has a dynamic initializer, don't use its
DECL_INITIAL which doesn't reflect the real value. */
if (VAR_P (decl)
&& TREE_STATIC (decl)
&& !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl)
&& DECL_NONTRIVIALLY_INITIALIZED_P (decl))
break;
decl = init;
}
return unshare_p ? unshare_expr (decl) : decl;
}
/* If DECL is a CONST_DECL, or a constant VAR_DECL initialized by constant
of integral or enumeration type, or a constexpr variable of scalar type,
then return that value. These are those variables permitted in constant
expressions by [5.19/1]. */
tree
scalar_constant_value (tree decl)
{
return constant_value_1 (decl, /*strict_p=*/true,
/*return_aggregate_cst_ok_p=*/false,
/*unshare_p=*/true);
}
/* Like scalar_constant_value, but can also return aggregate initializers.
If UNSHARE_P, return an unshared copy of the initializer. */
tree
decl_really_constant_value (tree decl, bool unshare_p /*= true*/)
{
return constant_value_1 (decl, /*strict_p=*/true,
/*return_aggregate_cst_ok_p=*/true,
/*unshare_p=*/unshare_p);
}
/* A more relaxed version of decl_really_constant_value, used by the
common C/C++ code. */
tree
decl_constant_value (tree decl, bool unshare_p)
{
return constant_value_1 (decl, /*strict_p=*/processing_template_decl,
/*return_aggregate_cst_ok_p=*/true,
/*unshare_p=*/unshare_p);
}
tree
decl_constant_value (tree decl)
{
return decl_constant_value (decl, /*unshare_p=*/true);
}
/* Common subroutines of build_new and build_vec_delete. */
/* Build and return a NEW_EXPR. If NELTS is non-NULL, TYPE[NELTS] is
the type of the object being allocated; otherwise, it's just TYPE.
INIT is the initializer, if any. USE_GLOBAL_NEW is true if the
user explicitly wrote "::operator new". PLACEMENT, if non-NULL, is
a vector of arguments to be provided as arguments to a placement
new operator. This routine performs no semantic checks; it just
creates and returns a NEW_EXPR. */
static tree
build_raw_new_expr (location_t loc, vec<tree, va_gc> *placement, tree type,
tree nelts, vec<tree, va_gc> *init, int use_global_new)
{
tree init_list;
tree new_expr;
/* If INIT is NULL, the we want to store NULL_TREE in the NEW_EXPR.
If INIT is not NULL, then we want to store VOID_ZERO_NODE. This
permits us to distinguish the case of a missing initializer "new
int" from an empty initializer "new int()". */
if (init == NULL)
init_list = NULL_TREE;
else if (init->is_empty ())
init_list = void_node;
else
init_list = build_tree_list_vec (init);
new_expr = build4_loc (loc, NEW_EXPR, build_pointer_type (type),
build_tree_list_vec (placement), type, nelts,
init_list);
NEW_EXPR_USE_GLOBAL (new_expr) = use_global_new;
TREE_SIDE_EFFECTS (new_expr) = 1;
return new_expr;
}
/* Diagnose uninitialized const members or reference members of type
TYPE. USING_NEW is used to disambiguate the diagnostic between a
new expression without a new-initializer and a declaration. Returns
the error count. */
static int
diagnose_uninitialized_cst_or_ref_member_1 (tree type, tree origin,
bool using_new, bool complain)
{
tree field;
int error_count = 0;
if (type_has_user_provided_constructor (type))
return 0;
for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
{
tree field_type;
if (TREE_CODE (field) != FIELD_DECL)
continue;
field_type = strip_array_types (TREE_TYPE (field));
if (type_has_user_provided_constructor (field_type))
continue;
if (TYPE_REF_P (field_type))
{
++ error_count;
if (complain)
{
if (DECL_CONTEXT (field) == origin)
{
if (using_new)
error ("uninitialized reference member in %q#T "
"using %<new%> without new-initializer", origin);
else
error ("uninitialized reference member in %q#T", origin);
}
else
{
if (using_new)
error ("uninitialized reference member in base %q#T "
"of %q#T using %<new%> without new-initializer",
DECL_CONTEXT (field), origin);
else
error ("uninitialized reference member in base %q#T "
"of %q#T", DECL_CONTEXT (field), origin);
}
inform (DECL_SOURCE_LOCATION (field),
"%q#D should be initialized", field);
}
}
if (CP_TYPE_CONST_P (field_type))
{
++ error_count;
if (complain)
{
if (DECL_CONTEXT (field) == origin)
{
if (using_new)
error ("uninitialized const member in %q#T "
"using %<new%> without new-initializer", origin);
else
error ("uninitialized const member in %q#T", origin);
}
else
{
if (using_new)
error ("uninitialized const member in base %q#T "
"of %q#T using %<new%> without new-initializer",
DECL_CONTEXT (field), origin);
else
error ("uninitialized const member in base %q#T "
"of %q#T", DECL_CONTEXT (field), origin);
}
inform (DECL_SOURCE_LOCATION (field),
"%q#D should be initialized", field);
}
}
if (CLASS_TYPE_P (field_type))
error_count
+= diagnose_uninitialized_cst_or_ref_member_1 (field_type, origin,
using_new, complain);
}
return error_count;
}
int
diagnose_uninitialized_cst_or_ref_member (tree type, bool using_new, bool complain)
{
return diagnose_uninitialized_cst_or_ref_member_1 (type, type, using_new, complain);
}
/* Call __cxa_bad_array_new_length to indicate that the size calculation
overflowed. Pretend it returns sizetype so that it plays nicely in the
COND_EXPR. */
tree
throw_bad_array_new_length (void)
{
if (!fn)
{
tree name = get_identifier ("__cxa_throw_bad_array_new_length");
fn = get_global_binding (name);
if (!fn)
fn = push_throw_library_fn
(name, build_function_type_list (sizetype, NULL_TREE));
}
return build_cxx_call (fn, 0, NULL, tf_warning_or_error);
}
/* Attempt to verify that the argument, OPER, of a placement new expression
refers to an object sufficiently large for an object of TYPE or an array
of NELTS of such objects when NELTS is non-null, and issue a warning when
it does not. SIZE specifies the size needed to construct the object or
array and captures the result of NELTS * sizeof (TYPE). (SIZE could be
greater when the array under construction requires a cookie to store
NELTS. GCC's placement new expression stores the cookie when invoking
a user-defined placement new operator function but not the default one.
Placement new expressions with user-defined placement new operator are
not diagnosed since we don't know how they use the buffer (this could
be a future extension). */
static void
warn_placement_new_too_small (tree type, tree nelts, tree size, tree oper)
{
location_t loc = cp_expr_loc_or_input_loc (oper);
STRIP_NOPS (oper);
/* Using a function argument or a (non-array) variable as an argument
to placement new is not checked since it's unknown what it might
point to. */
if (TREE_CODE (oper) == PARM_DECL
|| VAR_P (oper)
|| TREE_CODE (oper) == COMPONENT_REF)
return;
/* Evaluate any constant expressions. */
size = fold_non_dependent_expr (size);
access_ref ref;
ref.eval = [](tree x){ return fold_non_dependent_expr (x); };
ref.trail1special = warn_placement_new < 2;
tree objsize = compute_objsize (oper, 1, &ref);
if (!objsize)
return;
offset_int bytes_avail = wi::to_offset (objsize);
offset_int bytes_need;
if (CONSTANT_CLASS_P (size))
bytes_need = wi::to_offset (size);
else if (nelts && CONSTANT_CLASS_P (nelts))
bytes_need = (wi::to_offset (nelts)
* wi::to_offset (TYPE_SIZE_UNIT (type)));
else if (tree_fits_uhwi_p (TYPE_SIZE_UNIT (type)))
bytes_need = wi::to_offset (TYPE_SIZE_UNIT (type));
else
{
/* The type is a VLA. */
return;
}
if (bytes_avail >= bytes_need)
return;
/* True when the size to mention in the warning is exact as opposed
to "at least N". */
const bool exact_size = (ref.offrng[0] == ref.offrng[1]
|| ref.sizrng[1] - ref.offrng[0] == 0);
tree opertype = ref.ref ? TREE_TYPE (ref.ref) : TREE_TYPE (oper);
bool warned = false;
if (nelts)
nelts = fold_for_warn (nelts);
if (nelts)
if (CONSTANT_CLASS_P (nelts))
warned = warning_at (loc, OPT_Wplacement_new_,
(exact_size
? G_("placement new constructing an object "
"of type %<%T [%wu]%> and size %qwu "
"in a region of type %qT and size %qwi")
: G_("placement new constructing an object "
"of type %<%T [%wu]%> and size %qwu "
"in a region of type %qT and size "
"at most %qwu")),
type, tree_to_uhwi (nelts),
bytes_need.to_uhwi (),
opertype, bytes_avail.to_uhwi ());
else
warned = warning_at (loc, OPT_Wplacement_new_,
(exact_size
? G_("placement new constructing an array "
"of objects of type %qT and size %qwu "
"in a region of type %qT and size %qwi")
: G_("placement new constructing an array "
"of objects of type %qT and size %qwu "
"in a region of type %qT and size "
"at most %qwu")),
type, bytes_need.to_uhwi (), opertype,
bytes_avail.to_uhwi ());
else
warned = warning_at (loc, OPT_Wplacement_new_,
(exact_size
? G_("placement new constructing an object "
"of type %qT and size %qwu in a region "
"of type %qT and size %qwi")
: G_("placement new constructing an object "
"of type %qT "
"and size %qwu in a region of type %qT "
"and size at most %qwu")),
type, bytes_need.to_uhwi (), opertype,
bytes_avail.to_uhwi ());
if (!warned || !ref.ref)
return;
if (ref.offrng[0] == 0 || !ref.offset_bounded ())
/* Avoid mentioning the offset when its lower bound is zero
or when it's impossibly large. */
inform (DECL_SOURCE_LOCATION (ref.ref),
"%qD declared here", ref.ref);
else if (ref.offrng[0] == ref.offrng[1])
inform (DECL_SOURCE_LOCATION (ref.ref),
"at offset %wi from %qD declared here",
ref.offrng[0].to_shwi (), ref.ref);
else
inform (DECL_SOURCE_LOCATION (ref.ref),
"at offset [%wi, %wi] from %qD declared here",
ref.offrng[0].to_shwi (), ref.offrng[1].to_shwi (), ref.ref);
}
/* True if alignof(T) > __STDCPP_DEFAULT_NEW_ALIGNMENT__. */
bool
type_has_new_extended_alignment (tree t)
{
return (aligned_new_threshold
&& TYPE_ALIGN_UNIT (t) > (unsigned)aligned_new_threshold);
}
/* Return the alignment we expect malloc to guarantee. This should just be
MALLOC_ABI_ALIGNMENT, but that macro defaults to only BITS_PER_WORD for some
reason, so don't let the threshold be smaller than max_align_t_align. */
unsigned
malloc_alignment ()
{
return MAX (max_align_t_align(), MALLOC_ABI_ALIGNMENT);
}
/* Determine whether an allocation function is a namespace-scope
non-replaceable placement new function. See DR 1748. */
static bool
std_placement_new_fn_p (tree alloc_fn)
{
if (DECL_NAMESPACE_SCOPE_P (alloc_fn))
{
tree first_arg = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (alloc_fn)));
if ((TREE_VALUE (first_arg) == ptr_type_node)
&& TREE_CHAIN (first_arg) == void_list_node)
return true;
}
return false;
}
/* For element type ELT_TYPE, return the appropriate type of the heap object
containing such element(s). COOKIE_SIZE is NULL or the size of cookie
in bytes. FULL_SIZE is NULL if it is unknown how big the heap allocation
will be, otherwise size of the heap object. If COOKIE_SIZE is NULL,
return array type ELT_TYPE[FULL_SIZE / sizeof(ELT_TYPE)], otherwise return
struct { size_t[COOKIE_SIZE/sizeof(size_t)]; ELT_TYPE[N]; }
where N is nothing (flexible array member) if FULL_SIZE is NULL, otherwise
it is computed such that the size of the struct fits into FULL_SIZE. */
tree
build_new_constexpr_heap_type (tree elt_type, tree cookie_size, tree full_size)
{
gcc_assert (cookie_size == NULL_TREE || tree_fits_uhwi_p (cookie_size));
gcc_assert (full_size == NULL_TREE || tree_fits_uhwi_p (full_size));
unsigned HOST_WIDE_INT csz = cookie_size ? tree_to_uhwi (cookie_size) : 0;
tree itype2 = NULL_TREE;
if (full_size)
{
unsigned HOST_WIDE_INT fsz = tree_to_uhwi (full_size);
gcc_assert (fsz >= csz);
fsz -= csz;
fsz /= int_size_in_bytes (elt_type);
itype2 = build_index_type (size_int (fsz - 1));
if (!cookie_size)
return build_cplus_array_type (elt_type, itype2);
}
else
gcc_assert (cookie_size);
csz /= int_size_in_bytes (sizetype);
tree itype1 = build_index_type (size_int (csz - 1));
tree atype1 = build_cplus_array_type (sizetype, itype1);
tree atype2 = build_cplus_array_type (elt_type, itype2);
tree rtype = cxx_make_type (RECORD_TYPE);
TYPE_NAME (rtype) = heap_identifier;
tree fld1 = build_decl (UNKNOWN_LOCATION, FIELD_DECL, NULL_TREE, atype1);
tree fld2 = build_decl (UNKNOWN_LOCATION, FIELD_DECL, NULL_TREE, atype2);
DECL_FIELD_CONTEXT (fld1) = rtype;
DECL_FIELD_CONTEXT (fld2) = rtype;
DECL_ARTIFICIAL (fld1) = true;
DECL_ARTIFICIAL (fld2) = true;
TYPE_FIELDS (rtype) = fld1;
DECL_CHAIN (fld1) = fld2;
layout_type (rtype);
return rtype;
}
/* Help the constexpr code to find the right type for the heap variable
by adding a NOP_EXPR around ALLOC_CALL if needed for cookie_size.
Return ALLOC_CALL or ALLOC_CALL cast to a pointer to
struct { size_t[cookie_size/sizeof(size_t)]; elt_type[]; }. */
static tree
maybe_wrap_new_for_constexpr (tree alloc_call, tree elt_type, tree cookie_size)
{
if (cxx_dialect < cxx20)
return alloc_call;
if (current_function_decl != NULL_TREE
&& !DECL_DECLARED_CONSTEXPR_P (current_function_decl))
return alloc_call;
tree call_expr = extract_call_expr (alloc_call);
if (call_expr == error_mark_node)
return alloc_call;
tree alloc_call_fndecl = cp_get_callee_fndecl_nofold (call_expr);
if (alloc_call_fndecl == NULL_TREE
|| !IDENTIFIER_NEW_OP_P (DECL_NAME (alloc_call_fndecl))
|| CP_DECL_CONTEXT (alloc_call_fndecl) != global_namespace)
return alloc_call;
tree rtype = build_new_constexpr_heap_type (elt_type, cookie_size,
NULL_TREE);
return build_nop (build_pointer_type (rtype), alloc_call);
}
/* Generate code for a new-expression, including calling the "operator
new" function, initializing the object, and, if an exception occurs
during construction, cleaning up. The arguments are as for
build_raw_new_expr. This may change PLACEMENT and INIT.
TYPE is the type of the object being constructed, possibly an array
of NELTS elements when NELTS is non-null (in "new T[NELTS]", T may
be an array of the form U[inner], with the whole expression being
"new U[NELTS][inner]"). */
static tree
build_new_1 (vec<tree, va_gc> **placement, tree type, tree nelts,
vec<tree, va_gc> **init, bool globally_qualified_p,
tsubst_flags_t complain)
{
tree size, rval;
/* True iff this is a call to "operator new[]" instead of just
"operator new". */
bool array_p = false;
/* If ARRAY_P is true, the element type of the array. This is never
an ARRAY_TYPE; for something like "new int[3][4]", the
ELT_TYPE is "int". If ARRAY_P is false, this is the same type as
TYPE. */
tree elt_type;
/* The type of the new-expression. (This type is always a pointer
type.) */
tree pointer_type;
tree non_const_pointer_type;
/* The most significant array bound in int[OUTER_NELTS][inner]. */
tree outer_nelts = NULL_TREE;
/* For arrays with a non-constant number of elements, a bounds checks
on the NELTS parameter to avoid integer overflow at runtime. */
tree outer_nelts_check = NULL_TREE;
bool outer_nelts_from_type = false;
/* Number of the "inner" elements in "new T[OUTER_NELTS][inner]". */
offset_int inner_nelts_count = 1;
tree alloc_call, alloc_expr;
/* Size of the inner array elements (those with constant dimensions). */
offset_int inner_size;
/* The address returned by the call to "operator new". This node is
a VAR_DECL and is therefore reusable. */
tree alloc_node;
tree alloc_fn;
tree cookie_expr, init_expr;
int nothrow, check_new;
/* If non-NULL, the number of extra bytes to allocate at the
beginning of the storage allocated for an array-new expression in
order to store the number of elements. */
tree cookie_size = NULL_TREE;
tree placement_first;
tree placement_expr = NULL_TREE;
/* True if the function we are calling is a placement allocation
function. */
bool placement_allocation_fn_p;
/* True if the storage must be initialized, either by a constructor
or due to an explicit new-initializer. */
bool is_initialized;
/* The address of the thing allocated, not including any cookie. In
particular, if an array cookie is in use, DATA_ADDR is the
address of the first array element. This node is a VAR_DECL, and
is therefore reusable. */
tree data_addr;
tree init_preeval_expr = NULL_TREE;
tree orig_type = type;
if (nelts)
{
outer_nelts = nelts;
array_p = true;
}
else if (TREE_CODE (type) == ARRAY_TYPE)
{
/* Transforms new (T[N]) to new T[N]. The former is a GNU
extension for variable N. (This also covers new T where T is
a VLA typedef.) */
array_p = true;
nelts = array_type_nelts_top (type);
outer_nelts = nelts;
type = TREE_TYPE (type);
outer_nelts_from_type = true;
}
/* Lots of logic below depends on whether we have a constant number of
elements, so go ahead and fold it now. */
const_tree cst_outer_nelts = fold_non_dependent_expr (outer_nelts, complain);
/* If our base type is an array, then make sure we know how many elements
it has. */
for (elt_type = type;
TREE_CODE (elt_type) == ARRAY_TYPE;
elt_type = TREE_TYPE (elt_type))
{
tree inner_nelts = array_type_nelts_top (elt_type);
tree inner_nelts_cst = maybe_constant_value (inner_nelts);
if (TREE_CODE (inner_nelts_cst) == INTEGER_CST)
{
wi::overflow_type overflow;
offset_int result = wi::mul (wi::to_offset (inner_nelts_cst),
inner_nelts_count, SIGNED, &overflow);
if (overflow)
{
if (complain & tf_error)
error ("integer overflow in array size");
nelts = error_mark_node;