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/* Process declarations and variables for C compiler.
Copyright (C) 1988-2021 Free Software Foundation, Inc.
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/>. */
/* Process declarations and symbol lookup for C front end.
Also constructs types; the standard scalar types at initialization,
and structure, union, array and enum types when they are declared. */
/* ??? not all decl nodes are given the most useful possible
line numbers. For example, the CONST_DECLs for enum values. */
#include "config.h"
#define INCLUDE_STRING
#define INCLUDE_UNIQUE_PTR
#include "system.h"
#include "coretypes.h"
#include "target.h"
#include "function.h"
#include "c-tree.h"
#include "timevar.h"
#include "stringpool.h"
#include "cgraph.h"
#include "intl.h"
#include "print-tree.h"
#include "stor-layout.h"
#include "varasm.h"
#include "attribs.h"
#include "toplev.h"
#include "debug.h"
#include "c-family/c-objc.h"
#include "c-family/c-pragma.h"
#include "c-family/c-ubsan.h"
#include "c-lang.h"
#include "langhooks.h"
#include "tree-iterator.h"
#include "dumpfile.h"
#include "plugin.h"
#include "c-family/c-ada-spec.h"
#include "builtins.h"
#include "spellcheck-tree.h"
#include "gcc-rich-location.h"
#include "asan.h"
#include "c-family/name-hint.h"
#include "c-family/known-headers.h"
#include "c-family/c-spellcheck.h"
#include "context.h" /* For 'g'. */
#include "omp-general.h"
#include "omp-offload.h" /* For offload_vars. */
#include "tree-pretty-print.h"
/* In grokdeclarator, distinguish syntactic contexts of declarators. */
enum decl_context
{ NORMAL, /* Ordinary declaration */
FUNCDEF, /* Function definition */
PARM, /* Declaration of parm before function body */
FIELD, /* Declaration inside struct or union */
TYPENAME}; /* Typename (inside cast or sizeof) */
/* States indicating how grokdeclarator() should handle declspecs marked
with __attribute__((deprecated)) or __attribute__((unavailable)).
An object declared as __attribute__((unavailable)) should suppress
any reports of being declared with unavailable or deprecated items.
An object declared as __attribute__((deprecated)) should suppress
warnings of uses of other deprecated items. */
enum deprecated_states {
DEPRECATED_NORMAL,
DEPRECATED_SUPPRESS,
UNAVAILABLE_DEPRECATED_SUPPRESS
};
/* Nonzero if we have seen an invalid cross reference
to a struct, union, or enum, but not yet printed the message. */
tree pending_invalid_xref;
/* File and line to appear in the eventual error message. */
location_t pending_invalid_xref_location;
/* The file and line that the prototype came from if this is an
old-style definition; used for diagnostics in
store_parm_decls_oldstyle. */
static location_t current_function_prototype_locus;
/* Whether this prototype was built-in. */
static bool current_function_prototype_built_in;
/* The argument type information of this prototype. */
static tree current_function_prototype_arg_types;
/* The argument information structure for the function currently being
defined. */
static struct c_arg_info *current_function_arg_info;
/* The obstack on which parser and related data structures, which are
not live beyond their top-level declaration or definition, are
allocated. */
struct obstack parser_obstack;
/* The current statement tree. */
static GTY(()) struct stmt_tree_s c_stmt_tree;
/* Zero if we are not in an iteration or switch statement, otherwise
a bitmask. See bitmask definitions in c-tree.h. */
unsigned char in_statement;
/* A list of decls to be made automatically visible in each file scope. */
static GTY(()) tree visible_builtins;
/* Set to 0 at beginning of a function definition, set to 1 if
a return statement that specifies a return value is seen. */
int current_function_returns_value;
/* Set to 0 at beginning of a function definition, set to 1 if
a return statement with no argument is seen. */
int current_function_returns_null;
/* Set to 0 at beginning of a function definition, set to 1 if
a call to a noreturn function is seen. */
int current_function_returns_abnormally;
/* Set to nonzero by `grokdeclarator' for a function
whose return type is defaulted, if warnings for this are desired. */
static int warn_about_return_type;
/* Nonzero when the current toplevel function contains a declaration
of a nested function which is never defined. */
static bool undef_nested_function;
/* If non-zero, implicit "omp declare target" attribute is added into the
attribute lists. */
int current_omp_declare_target_attribute;
/* Each c_binding structure describes one binding of an identifier to
a decl. All the decls in a scope - irrespective of namespace - are
chained together by the ->prev field, which (as the name implies)
runs in reverse order. All the decls in a given namespace bound to
a given identifier are chained by the ->shadowed field, which runs
from inner to outer scopes.
The ->decl field usually points to a DECL node, but there are two
exceptions. In the namespace of type tags, the bound entity is a
RECORD_TYPE, UNION_TYPE, or ENUMERAL_TYPE node. If an undeclared
identifier is encountered, it is bound to error_mark_node to
suppress further errors about that identifier in the current
function.
The ->u.type field stores the type of the declaration in this scope;
if NULL, the type is the type of the ->decl field. This is only of
relevance for objects with external or internal linkage which may
be redeclared in inner scopes, forming composite types that only
persist for the duration of those scopes. In the external scope,
this stores the composite of all the types declared for this
object, visible or not. The ->inner_comp field (used only at file
scope) stores whether an incomplete array type at file scope was
completed at an inner scope to an array size other than 1.
The ->u.label field is used for labels. It points to a structure
which stores additional information used for warnings.
The depth field is copied from the scope structure that holds this
decl. It is used to preserve the proper ordering of the ->shadowed
field (see bind()) and also for a handful of special-case checks.
Finally, the invisible bit is true for a decl which should be
ignored for purposes of normal name lookup, and the nested bit is
true for a decl that's been bound a second time in an inner scope;
in all such cases, the binding in the outer scope will have its
invisible bit true. */
struct GTY((chain_next ("%h.prev"))) c_binding {
union GTY(()) { /* first so GTY desc can use decl */
tree GTY((tag ("0"))) type; /* the type in this scope */
struct c_label_vars * GTY((tag ("1"))) label; /* for warnings */
} GTY((desc ("TREE_CODE (%0.decl) == LABEL_DECL"))) u;
tree decl; /* the decl bound */
tree id; /* the identifier it's bound to */
struct c_binding *prev; /* the previous decl in this scope */
struct c_binding *shadowed; /* the innermost decl shadowed by this one */
unsigned int depth : 28; /* depth of this scope */
BOOL_BITFIELD invisible : 1; /* normal lookup should ignore this binding */
BOOL_BITFIELD nested : 1; /* do not set DECL_CONTEXT when popping */
BOOL_BITFIELD inner_comp : 1; /* incomplete array completed in inner scope */
BOOL_BITFIELD in_struct : 1; /* currently defined as struct field */
location_t locus; /* location for nested bindings */
};
#define B_IN_SCOPE(b1, b2) ((b1)->depth == (b2)->depth)
#define B_IN_CURRENT_SCOPE(b) ((b)->depth == current_scope->depth)
#define B_IN_FILE_SCOPE(b) ((b)->depth == 1 /*file_scope->depth*/)
#define B_IN_EXTERNAL_SCOPE(b) ((b)->depth == 0 /*external_scope->depth*/)
/* Each C symbol points to three linked lists of c_binding structures.
These describe the values of the identifier in the three different
namespaces defined by the language. */
struct GTY(()) lang_identifier {
struct c_common_identifier common_id;
struct c_binding *symbol_binding; /* vars, funcs, constants, typedefs */
struct c_binding *tag_binding; /* struct/union/enum tags */
struct c_binding *label_binding; /* labels */
};
/* Validate c-lang.c's assumptions. */
extern char C_SIZEOF_STRUCT_LANG_IDENTIFIER_isnt_accurate
[(sizeof(struct lang_identifier) == C_SIZEOF_STRUCT_LANG_IDENTIFIER) ? 1 : -1];
/* The binding oracle; see c-tree.h. */
void (*c_binding_oracle) (enum c_oracle_request, tree identifier);
/* This flag is set on an identifier if we have previously asked the
binding oracle for this identifier's symbol binding. */
#define I_SYMBOL_CHECKED(node) \
(TREE_LANG_FLAG_4 (IDENTIFIER_NODE_CHECK (node)))
static inline struct c_binding* *
i_symbol_binding (tree node)
{
struct lang_identifier *lid
= (struct lang_identifier *) IDENTIFIER_NODE_CHECK (node);
if (lid->symbol_binding == NULL
&& c_binding_oracle != NULL
&& !I_SYMBOL_CHECKED (node))
{
/* Set the "checked" flag first, to avoid infinite recursion
when the binding oracle calls back into gcc. */
I_SYMBOL_CHECKED (node) = 1;
c_binding_oracle (C_ORACLE_SYMBOL, node);
}
return &lid->symbol_binding;
}
#define I_SYMBOL_BINDING(node) (*i_symbol_binding (node))
#define I_SYMBOL_DECL(node) \
(I_SYMBOL_BINDING(node) ? I_SYMBOL_BINDING(node)->decl : 0)
/* This flag is set on an identifier if we have previously asked the
binding oracle for this identifier's tag binding. */
#define I_TAG_CHECKED(node) \
(TREE_LANG_FLAG_5 (IDENTIFIER_NODE_CHECK (node)))
static inline struct c_binding **
i_tag_binding (tree node)
{
struct lang_identifier *lid
= (struct lang_identifier *) IDENTIFIER_NODE_CHECK (node);
if (lid->tag_binding == NULL
&& c_binding_oracle != NULL
&& !I_TAG_CHECKED (node))
{
/* Set the "checked" flag first, to avoid infinite recursion
when the binding oracle calls back into gcc. */
I_TAG_CHECKED (node) = 1;
c_binding_oracle (C_ORACLE_TAG, node);
}
return &lid->tag_binding;
}
#define I_TAG_BINDING(node) (*i_tag_binding (node))
#define I_TAG_DECL(node) \
(I_TAG_BINDING(node) ? I_TAG_BINDING(node)->decl : 0)
/* This flag is set on an identifier if we have previously asked the
binding oracle for this identifier's label binding. */
#define I_LABEL_CHECKED(node) \
(TREE_LANG_FLAG_6 (IDENTIFIER_NODE_CHECK (node)))
static inline struct c_binding **
i_label_binding (tree node)
{
struct lang_identifier *lid
= (struct lang_identifier *) IDENTIFIER_NODE_CHECK (node);
if (lid->label_binding == NULL
&& c_binding_oracle != NULL
&& !I_LABEL_CHECKED (node))
{
/* Set the "checked" flag first, to avoid infinite recursion
when the binding oracle calls back into gcc. */
I_LABEL_CHECKED (node) = 1;
c_binding_oracle (C_ORACLE_LABEL, node);
}
return &lid->label_binding;
}
#define I_LABEL_BINDING(node) (*i_label_binding (node))
#define I_LABEL_DECL(node) \
(I_LABEL_BINDING(node) ? I_LABEL_BINDING(node)->decl : 0)
/* The resulting tree type. */
union GTY((desc ("TREE_CODE (&%h.generic) == IDENTIFIER_NODE"),
chain_next ("(union lang_tree_node *) c_tree_chain_next (&%h.generic)"))) lang_tree_node
{
union tree_node GTY ((tag ("0"),
desc ("tree_node_structure (&%h)")))
generic;
struct lang_identifier GTY ((tag ("1"))) identifier;
};
/* Track bindings and other things that matter for goto warnings. For
efficiency, we do not gather all the decls at the point of
definition. Instead, we point into the bindings structure. As
scopes are popped, we update these structures and gather the decls
that matter at that time. */
struct GTY(()) c_spot_bindings {
/* The currently open scope which holds bindings defined when the
label was defined or the goto statement was found. */
struct c_scope *scope;
/* The bindings in the scope field which were defined at the point
of the label or goto. This lets us look at older or newer
bindings in the scope, as appropriate. */
struct c_binding *bindings_in_scope;
/* The number of statement expressions that have started since this
label or goto statement was defined. This is zero if we are at
the same statement expression level. It is positive if we are in
a statement expression started since this spot. It is negative
if this spot was in a statement expression and we have left
it. */
int stmt_exprs;
/* Whether we started in a statement expression but are no longer in
it. This is set to true if stmt_exprs ever goes negative. */
bool left_stmt_expr;
};
/* This structure is used to keep track of bindings seen when a goto
statement is defined. This is only used if we see the goto
statement before we see the label. */
struct GTY(()) c_goto_bindings {
/* The location of the goto statement. */
location_t loc;
/* The bindings of the goto statement. */
struct c_spot_bindings goto_bindings;
};
typedef struct c_goto_bindings *c_goto_bindings_p;
/* The additional information we keep track of for a label binding.
These fields are updated as scopes are popped. */
struct GTY(()) c_label_vars {
/* The shadowed c_label_vars, when one label shadows another (which
can only happen using a __label__ declaration). */
struct c_label_vars *shadowed;
/* The bindings when the label was defined. */
struct c_spot_bindings label_bindings;
/* A list of decls that we care about: decls about which we should
warn if a goto branches to this label from later in the function.
Decls are added to this list as scopes are popped. We only add
the decls that matter. */
vec<tree, va_gc> *decls_in_scope;
/* A list of goto statements to this label. This is only used for
goto statements seen before the label was defined, so that we can
issue appropriate warnings for them. */
vec<c_goto_bindings_p, va_gc> *gotos;
};
/* Each c_scope structure describes the complete contents of one
scope. Four scopes are distinguished specially: the innermost or
current scope, the innermost function scope, the file scope (always
the second to outermost) and the outermost or external scope.
Most declarations are recorded in the current scope.
All normal label declarations are recorded in the innermost
function scope, as are bindings of undeclared identifiers to
error_mark_node. (GCC permits nested functions as an extension,
hence the 'innermost' qualifier.) Explicitly declared labels
(using the __label__ extension) appear in the current scope.
Being in the file scope (current_scope == file_scope) causes
special behavior in several places below. Also, under some
conditions the Objective-C front end records declarations in the
file scope even though that isn't the current scope.
All declarations with external linkage are recorded in the external
scope, even if they aren't visible there; this models the fact that
such declarations are visible to the entire program, and (with a
bit of cleverness, see pushdecl) allows diagnosis of some violations
of C99 6.2.2p7 and 6.2.7p2:
If, within the same translation unit, the same identifier appears
with both internal and external linkage, the behavior is
undefined.
All declarations that refer to the same object or function shall
have compatible type; otherwise, the behavior is undefined.
Initially only the built-in declarations, which describe compiler
intrinsic functions plus a subset of the standard library, are in
this scope.
The order of the blocks list matters, and it is frequently appended
to. To avoid having to walk all the way to the end of the list on
each insertion, or reverse the list later, we maintain a pointer to
the last list entry. (FIXME: It should be feasible to use a reversed
list here.)
The bindings list is strictly in reverse order of declarations;
pop_scope relies on this. */
struct GTY((chain_next ("%h.outer"))) c_scope {
/* The scope containing this one. */
struct c_scope *outer;
/* The next outermost function scope. */
struct c_scope *outer_function;
/* All bindings in this scope. */
struct c_binding *bindings;
/* For each scope (except the global one), a chain of BLOCK nodes
for all the scopes that were entered and exited one level down. */
tree blocks;
tree blocks_last;
/* The depth of this scope. Used to keep the ->shadowed chain of
bindings sorted innermost to outermost. */
unsigned int depth : 28;
/* True if we are currently filling this scope with parameter
declarations. */
BOOL_BITFIELD parm_flag : 1;
/* True if we saw [*] in this scope. Used to give an error messages
if these appears in a function definition. */
BOOL_BITFIELD had_vla_unspec : 1;
/* True if we already complained about forward parameter decls
in this scope. This prevents double warnings on
foo (int a; int b; ...) */
BOOL_BITFIELD warned_forward_parm_decls : 1;
/* True if this is the outermost block scope of a function body.
This scope contains the parameters, the local variables declared
in the outermost block, and all the labels (except those in
nested functions, or declared at block scope with __label__). */
BOOL_BITFIELD function_body : 1;
/* True means make a BLOCK for this scope no matter what. */
BOOL_BITFIELD keep : 1;
/* True means that an unsuffixed float constant is _Decimal64. */
BOOL_BITFIELD float_const_decimal64 : 1;
/* True if this scope has any label bindings. This is used to speed
up searching for labels when popping scopes, particularly since
labels are normally only found at function scope. */
BOOL_BITFIELD has_label_bindings : 1;
/* True if we should issue a warning if a goto statement crosses any
of the bindings. We still need to check the list of bindings to
find the specific ones we need to warn about. This is true if
decl_jump_unsafe would return true for any of the bindings. This
is used to avoid looping over all the bindings unnecessarily. */
BOOL_BITFIELD has_jump_unsafe_decl : 1;
};
/* The scope currently in effect. */
static GTY(()) struct c_scope *current_scope;
/* The innermost function scope. Ordinary (not explicitly declared)
labels, bindings to error_mark_node, and the lazily-created
bindings of __func__ and its friends get this scope. */
static GTY(()) struct c_scope *current_function_scope;
/* The C file scope. This is reset for each input translation unit. */
static GTY(()) struct c_scope *file_scope;
/* The outermost scope. This is used for all declarations with
external linkage, and only these, hence the name. */
static GTY(()) struct c_scope *external_scope;
/* A chain of c_scope structures awaiting reuse. */
static GTY((deletable)) struct c_scope *scope_freelist;
/* A chain of c_binding structures awaiting reuse. */
static GTY((deletable)) struct c_binding *binding_freelist;
/* Append VAR to LIST in scope SCOPE. */
#define SCOPE_LIST_APPEND(scope, list, decl) do { \
struct c_scope *s_ = (scope); \
tree d_ = (decl); \
if (s_->list##_last) \
BLOCK_CHAIN (s_->list##_last) = d_; \
else \
s_->list = d_; \
s_->list##_last = d_; \
} while (0)
/* Concatenate FROM in scope FSCOPE onto TO in scope TSCOPE. */
#define SCOPE_LIST_CONCAT(tscope, to, fscope, from) do { \
struct c_scope *t_ = (tscope); \
struct c_scope *f_ = (fscope); \
if (t_->to##_last) \
BLOCK_CHAIN (t_->to##_last) = f_->from; \
else \
t_->to = f_->from; \
t_->to##_last = f_->from##_last; \
} while (0)
/* A c_inline_static structure stores details of a static identifier
referenced in a definition of a function that may be an inline
definition if no subsequent declaration of that function uses
"extern" or does not use "inline". */
struct GTY((chain_next ("%h.next"))) c_inline_static {
/* The location for a diagnostic. */
location_t location;
/* The function that may be an inline definition. */
tree function;
/* The object or function referenced. */
tree static_decl;
/* What sort of reference this is. */
enum c_inline_static_type type;
/* The next such structure or NULL. */
struct c_inline_static *next;
};
/* List of static identifiers used or referenced in functions that may
be inline definitions. */
static GTY(()) struct c_inline_static *c_inline_statics;
/* True means unconditionally make a BLOCK for the next scope pushed. */
static bool keep_next_level_flag;
/* True means the next call to push_scope will be the outermost scope
of a function body, so do not push a new scope, merely cease
expecting parameter decls. */
static bool next_is_function_body;
/* A vector of pointers to c_binding structures. */
typedef struct c_binding *c_binding_ptr;
/* Information that we keep for a struct or union while it is being
parsed. */
class c_struct_parse_info
{
public:
/* If warn_cxx_compat, a list of types defined within this
struct. */
auto_vec<tree> struct_types;
/* If warn_cxx_compat, a list of field names which have bindings,
and which are defined in this struct, but which are not defined
in any enclosing struct. This is used to clear the in_struct
field of the c_bindings structure. */
auto_vec<c_binding_ptr> fields;
/* If warn_cxx_compat, a list of typedef names used when defining
fields in this struct. */
auto_vec<tree> typedefs_seen;
};
/* Information for the struct or union currently being parsed, or
NULL if not parsing a struct or union. */
static class c_struct_parse_info *struct_parse_info;
/* Forward declarations. */
static tree lookup_name_in_scope (tree, struct c_scope *);
static tree c_make_fname_decl (location_t, tree, int);
static tree grokdeclarator (const struct c_declarator *,
struct c_declspecs *,
enum decl_context, bool, tree *, tree *, tree *,
bool *, enum deprecated_states);
static tree grokparms (struct c_arg_info *, bool);
static void layout_array_type (tree);
static void warn_defaults_to (location_t, int, const char *, ...)
ATTRIBUTE_GCC_DIAG(3,4);
static const char *header_for_builtin_fn (tree);
/* T is a statement. Add it to the statement-tree. This is the
C/ObjC version--C++ has a slightly different version of this
function. */
tree
add_stmt (tree t)
{
enum tree_code code = TREE_CODE (t);
if (CAN_HAVE_LOCATION_P (t) && code != LABEL_EXPR)
{
if (!EXPR_HAS_LOCATION (t))
SET_EXPR_LOCATION (t, input_location);
}
if (code == LABEL_EXPR || code == CASE_LABEL_EXPR)
STATEMENT_LIST_HAS_LABEL (cur_stmt_list) = 1;
/* Add T to the statement-tree. Non-side-effect statements need to be
recorded during statement expressions. */
if (!building_stmt_list_p ())
push_stmt_list ();
append_to_statement_list_force (t, &cur_stmt_list);
return t;
}
/* Build a pointer type using the default pointer mode. */
static tree
c_build_pointer_type (tree to_type)
{
addr_space_t as = to_type == error_mark_node? ADDR_SPACE_GENERIC
: TYPE_ADDR_SPACE (to_type);
machine_mode pointer_mode;
if (as != ADDR_SPACE_GENERIC || c_default_pointer_mode == VOIDmode)
pointer_mode = targetm.addr_space.pointer_mode (as);
else
pointer_mode = c_default_pointer_mode;
return build_pointer_type_for_mode (to_type, pointer_mode, false);
}
/* Return true if we will want to say something if a goto statement
crosses DECL. */
static bool
decl_jump_unsafe (tree decl)
{
if (error_operand_p (decl))
return false;
/* Don't warn for compound literals. If a goto statement crosses
their initialization, it should cross also all the places where
the complit is used or where the complit address might be saved
into some variable, so code after the label to which goto jumps
should not be able to refer to the compound literal. */
if (VAR_P (decl) && C_DECL_COMPOUND_LITERAL_P (decl))
return false;
/* Always warn about crossing variably modified types. */
if ((VAR_P (decl) || TREE_CODE (decl) == TYPE_DECL)
&& variably_modified_type_p (TREE_TYPE (decl), NULL_TREE))
return true;
/* Otherwise, only warn if -Wgoto-misses-init and this is an
initialized automatic decl. */
if (warn_jump_misses_init
&& VAR_P (decl)
&& !TREE_STATIC (decl)
&& DECL_INITIAL (decl) != NULL_TREE)
return true;
return false;
}
void
c_print_identifier (FILE *file, tree node, int indent)
{
void (*save) (enum c_oracle_request, tree identifier);
/* Temporarily hide any binding oracle. Without this, calls to
debug_tree from the debugger will end up calling into the oracle,
making for a confusing debug session. As the oracle isn't needed
here for normal operation, it's simplest to suppress it. */
save = c_binding_oracle;
c_binding_oracle = NULL;
print_node (file, "symbol", I_SYMBOL_DECL (node), indent + 4);
print_node (file, "tag", I_TAG_DECL (node), indent + 4);
print_node (file, "label", I_LABEL_DECL (node), indent + 4);
if (C_IS_RESERVED_WORD (node) && C_RID_CODE (node) != RID_CXX_COMPAT_WARN)
{
tree rid = ridpointers[C_RID_CODE (node)];
indent_to (file, indent + 4);
fprintf (file, "rid " HOST_PTR_PRINTF " \"%s\"",
(void *) rid, IDENTIFIER_POINTER (rid));
}
c_binding_oracle = save;
}
/* Establish a binding between NAME, an IDENTIFIER_NODE, and DECL,
which may be any of several kinds of DECL or TYPE or error_mark_node,
in the scope SCOPE. */
static void
bind (tree name, tree decl, struct c_scope *scope, bool invisible,
bool nested, location_t locus)
{
struct c_binding *b, **here;
if (binding_freelist)
{
b = binding_freelist;
binding_freelist = b->prev;
}
else
b = ggc_alloc<c_binding> ();
b->shadowed = 0;
b->decl = decl;
b->id = name;
b->depth = scope->depth;
b->invisible = invisible;
b->nested = nested;
b->inner_comp = 0;
b->in_struct = 0;
b->locus = locus;
b->u.type = NULL;
b->prev = scope->bindings;
scope->bindings = b;
if (decl_jump_unsafe (decl))
scope->has_jump_unsafe_decl = 1;
if (!name)
return;
switch (TREE_CODE (decl))
{
case LABEL_DECL: here = &I_LABEL_BINDING (name); break;
case ENUMERAL_TYPE:
case UNION_TYPE:
case RECORD_TYPE: here = &I_TAG_BINDING (name); break;
case VAR_DECL:
case FUNCTION_DECL:
case TYPE_DECL:
case CONST_DECL:
case PARM_DECL:
case ERROR_MARK: here = &I_SYMBOL_BINDING (name); break;
default:
gcc_unreachable ();
}
/* Locate the appropriate place in the chain of shadowed decls
to insert this binding. Normally, scope == current_scope and
this does nothing. */
while (*here && (*here)->depth > scope->depth)
here = &(*here)->shadowed;
b->shadowed = *here;
*here = b;
}
/* Clear the binding structure B, stick it on the binding_freelist,
and return the former value of b->prev. This is used by pop_scope
and get_parm_info to iterate destructively over all the bindings
from a given scope. */
static struct c_binding *
free_binding_and_advance (struct c_binding *b)
{
struct c_binding *prev = b->prev;
memset (b, 0, sizeof (struct c_binding));
b->prev = binding_freelist;
binding_freelist = b;
return prev;
}
/* Bind a label. Like bind, but skip fields which aren't used for
labels, and add the LABEL_VARS value. */
static void
bind_label (tree name, tree label, struct c_scope *scope,
struct c_label_vars *label_vars)
{
struct c_binding *b;
bind (name, label, scope, /*invisible=*/false, /*nested=*/false,
UNKNOWN_LOCATION);
scope->has_label_bindings = true;
b = scope->bindings;
gcc_assert (b->decl == label);
label_vars->shadowed = b->u.label;
b->u.label = label_vars;
}
/* Hook called at end of compilation to assume 1 elt
for a file-scope tentative array defn that wasn't complete before. */
void
c_finish_incomplete_decl (tree decl)
{
if (VAR_P (decl))
{
tree type = TREE_TYPE (decl);
if (type != error_mark_node
&& TREE_CODE (type) == ARRAY_TYPE
&& !DECL_EXTERNAL (decl)
&& TYPE_DOMAIN (type) == NULL_TREE)
{
warning_at (DECL_SOURCE_LOCATION (decl),
0, "array %q+D assumed to have one element", decl);
complete_array_type (&TREE_TYPE (decl), NULL_TREE, true);
relayout_decl (decl);
}
}
}
/* Record that inline function FUNC contains a reference (location
LOC) to static DECL (file-scope or function-local according to
TYPE). */
void
record_inline_static (location_t loc, tree func, tree decl,
enum c_inline_static_type type)
{
c_inline_static *csi = ggc_alloc<c_inline_static> ();
csi->location = loc;
csi->function = func;
csi->static_decl = decl;
csi->type = type;
csi->next = c_inline_statics;
c_inline_statics = csi;
}
/* Check for references to static declarations in inline functions at
the end of the translation unit and diagnose them if the functions
are still inline definitions. */
static void
check_inline_statics (void)
{
struct c_inline_static *csi;
for (csi = c_inline_statics; csi; csi = csi->next)
{
if (DECL_EXTERNAL (csi->function))
switch (csi->type)
{
case csi_internal:
pedwarn (csi->location, 0,
"%qD is static but used in inline function %qD "
"which is not static", csi->static_decl, csi->function);
break;
case csi_modifiable:
pedwarn (csi->location, 0,
"%q+D is static but declared in inline function %qD "
"which is not static", csi->static_decl, csi->function);
break;
default:
gcc_unreachable ();
}
}
c_inline_statics = NULL;
}
/* Fill in a c_spot_bindings structure. If DEFINING is true, set it
for the current state, otherwise set it to uninitialized. */
static void
set_spot_bindings (struct c_spot_bindings *p, bool defining)
{
if (defining)
{
p->scope = current_scope;
p->bindings_in_scope = current_scope->bindings;
}
else
{
p->scope = NULL;
p->bindings_in_scope = NULL;
}
p->stmt_exprs = 0;
p->left_stmt_expr = false;
}
/* Update spot bindings P as we pop out of SCOPE. Return true if we
should push decls for a label. */
static bool
update_spot_bindings (struct c_scope *scope, struct c_spot_bindings *p)
{
if (p->scope != scope)
{
/* This label or goto is defined in some other scope, or it is a
label which is not yet defined. There is nothing to
update. */
return false;
}
/* Adjust the spot bindings to refer to the bindings already defined
in the enclosing scope. */
p->scope = scope->outer;
p->bindings_in_scope = p->scope->bindings;
return true;
}
/* The Objective-C front-end often needs to determine the current scope. */
void *
objc_get_current_scope (void)
{
return current_scope;
}
/* The following function is used only by Objective-C. It needs to live here
because it accesses the innards of c_scope. */
void
objc_mark_locals_volatile (void *enclosing_blk)
{
struct c_scope *scope;
struct c_binding *b;
for (scope = current_scope;
scope && scope != enclosing_blk;
scope = scope->outer)
{
for (b = scope->bindings; b; b = b->prev)
objc_volatilize_decl (b->decl);
/* Do not climb up past the current function. */
if (scope->function_body)
break;
}
}
/* Return true if we are in the global binding level. */
bool
global_bindings_p (void)
{
return current_scope == file_scope;
}
/* Return true if we're declaring parameters in an old-style function
declaration. */
bool
old_style_parameter_scope (void)
{
/* If processing parameters and there is no function statement list, we
* have an old-style function declaration. */
return (current_scope->parm_flag && !DECL_SAVED_TREE (current_function_decl));
}
void
keep_next_level (void)
{
keep_next_level_flag = true;
}
/* Set the flag for the FLOAT_CONST_DECIMAL64 pragma being ON. */
void
set_float_const_decimal64 (void)
{
current_scope->float_const_decimal64 = true;
}
/* Clear the flag for the FLOAT_CONST_DECIMAL64 pragma. */
void
clear_float_const_decimal64 (void)
{
current_scope->float_const_decimal64 = false;
}
/* Return nonzero if an unsuffixed float constant is _Decimal64. */
bool
float_const_decimal64_p (void)
{
return current_scope->float_const_decimal64;
}
/* Identify this scope as currently being filled with parameters. */
void
declare_parm_level (void)
{
current_scope->parm_flag = true;
}
void
push_scope (void)
{
if (next_is_function_body)
{
/* This is the transition from the parameters to the top level
of the function body. These are the same scope
(C99 6.2.1p4,6) so we do not push another scope structure.
next_is_function_body is set only by store_parm_decls, which
in turn is called when and only when we are about to
encounter the opening curly brace for the function body.
The outermost block of a function always gets a BLOCK node,
because the debugging output routines expect that each
function has at least one BLOCK. */
current_scope->parm_flag = false;
current_scope->function_body = true;
current_scope->keep = true;
current_scope->outer_function = current_function_scope;
current_function_scope = current_scope;
keep_next_level_flag = false;
next_is_function_body = false;
/* The FLOAT_CONST_DECIMAL64 pragma applies to nested scopes. */
if (current_scope->outer)
current_scope->float_const_decimal64
= current_scope->outer->float_const_decimal64;
else
current_scope->float_const_decimal64 = false;
}
else
{
struct c_scope *scope;
if (scope_freelist)
{
scope = scope_freelist;
scope_freelist = scope->outer;
}
else
scope = ggc_cleared_alloc<c_scope> ();
/* The FLOAT_CONST_DECIMAL64 pragma applies to nested scopes. */
if (current_scope)
scope->float_const_decimal64 = current_scope->float_const_decimal64;
else
scope->float_const_decimal64 = false;
scope->keep = keep_next_level_flag;
scope->outer = current_scope;
scope->depth = current_scope ? (current_scope->depth + 1) : 0;
/* Check for scope depth overflow. Unlikely (2^28 == 268,435,456) but
possible. */
if (current_scope && scope->depth == 0)
{
scope->depth--;
sorry ("GCC supports only %u nested scopes", scope->depth);
}
current_scope = scope;
keep_next_level_flag = false;
}
}
/* This is called when we are leaving SCOPE. For each label defined
in SCOPE, add any appropriate decls to its decls_in_scope fields.
These are the decls whose initialization will be skipped by a goto
later in the function. */
static void
update_label_decls (struct c_scope *scope)
{
struct c_scope *s;
s = scope;
while (s != NULL)
{
if (s->has_label_bindings)
{
struct c_binding *b;
for (b = s->bindings; b != NULL; b = b->prev)
{
struct c_label_vars *label_vars;
struct c_binding *b1;
bool hjud;
unsigned int ix;
struct c_goto_bindings *g;
if (TREE_CODE (b->decl) != LABEL_DECL)
continue;
label_vars = b->u.label;
b1 = label_vars->label_bindings.bindings_in_scope;
if (label_vars->label_bindings.scope == NULL)
hjud = false;
else
hjud = label_vars->label_bindings.scope->has_jump_unsafe_decl;
if (update_spot_bindings (scope, &label_vars->label_bindings))
{
/* This label is defined in this scope. */
if (hjud)
{
for (; b1 != NULL; b1 = b1->prev)
{
/* A goto from later in the function to this
label will never see the initialization
of B1, if any. Save it to issue a
warning if needed. */
if (decl_jump_unsafe (b1->decl))
vec_safe_push(label_vars->decls_in_scope, b1->decl);
}
}
}
/* Update the bindings of any goto statements associated
with this label. */
FOR_EACH_VEC_SAFE_ELT (label_vars->gotos, ix, g)
update_spot_bindings (scope, &g->goto_bindings);
}
}
/* Don't search beyond the current function. */
if (s == current_function_scope)
break;
s = s->outer;
}
}
/* Set the TYPE_CONTEXT of all of TYPE's variants to CONTEXT. */
static void
set_type_context (tree type, tree context)
{
for (type = TYPE_MAIN_VARIANT (type); type;
type = TYPE_NEXT_VARIANT (type))
TYPE_CONTEXT (type) = context;
}
/* Exit a scope. Restore the state of the identifier-decl mappings
that were in effect when this scope was entered. Return a BLOCK
node containing all the DECLs in this scope that are of interest
to debug info generation. */
tree
pop_scope (void)
{
struct c_scope *scope = current_scope;
tree block, context, p;
struct c_binding *b;
bool functionbody = scope->function_body;
bool keep = functionbody || scope->keep || scope->bindings;
update_label_decls (scope);
/* If appropriate, create a BLOCK to record the decls for the life
of this function. */
block = NULL_TREE;
if (keep)
{
block = make_node (BLOCK);
BLOCK_SUBBLOCKS (block) = scope->blocks;
TREE_USED (block) = 1;
/* In each subblock, record that this is its superior. */
for (p = scope->blocks; p; p = BLOCK_CHAIN (p))
BLOCK_SUPERCONTEXT (p) = block;
BLOCK_VARS (block) = NULL_TREE;
}
/* The TYPE_CONTEXTs for all of the tagged types belonging to this
scope must be set so that they point to the appropriate
construct, i.e. either to the current FUNCTION_DECL node, or
else to the BLOCK node we just constructed.
Note that for tagged types whose scope is just the formal
parameter list for some function type specification, we can't
properly set their TYPE_CONTEXTs here, because we don't have a
pointer to the appropriate FUNCTION_TYPE node readily available
to us. For those cases, the TYPE_CONTEXTs of the relevant tagged
type nodes get set in `grokdeclarator' as soon as we have created
the FUNCTION_TYPE node which will represent the "scope" for these
"parameter list local" tagged types. */
if (scope->function_body)
context = current_function_decl;
else if (scope == file_scope)
{
tree file_decl
= build_translation_unit_decl (get_identifier (main_input_filename));
context = file_decl;
debug_hooks->register_main_translation_unit (file_decl);
}
else
context = block;
/* Clear all bindings in this scope. */
for (b = scope->bindings; b; b = free_binding_and_advance (b))
{
p = b->decl;
switch (TREE_CODE (p))
{
case LABEL_DECL:
/* Warnings for unused labels, errors for undefined labels. */
if (TREE_USED (p) && !DECL_INITIAL (p))
{
error ("label %q+D used but not defined", p);
DECL_INITIAL (p) = error_mark_node;
}
else
warn_for_unused_label (p);
/* Labels go in BLOCK_VARS. */
DECL_CHAIN (p) = BLOCK_VARS (block);
BLOCK_VARS (block) = p;
gcc_assert (I_LABEL_BINDING (b->id) == b);
I_LABEL_BINDING (b->id) = b->shadowed;
/* Also pop back to the shadowed label_vars. */
release_tree_vector (b->u.label->decls_in_scope);
b->u.label = b->u.label->shadowed;
break;
case ENUMERAL_TYPE:
case UNION_TYPE:
case RECORD_TYPE:
set_type_context (p, context);
/* Types may not have tag-names, in which case the type
appears in the bindings list with b->id NULL. */
if (b->id)
{
gcc_assert (I_TAG_BINDING (b->id) == b);
I_TAG_BINDING (b->id) = b->shadowed;
}
break;
case FUNCTION_DECL:
/* Propagate TREE_ADDRESSABLE from nested functions to their
containing functions. */
if (!TREE_ASM_WRITTEN (p)
&& DECL_INITIAL (p) != NULL_TREE
&& TREE_ADDRESSABLE (p)
&& DECL_ABSTRACT_ORIGIN (p) != NULL_TREE
&& DECL_ABSTRACT_ORIGIN (p) != p)
TREE_ADDRESSABLE (DECL_ABSTRACT_ORIGIN (p)) = 1;
if (!TREE_PUBLIC (p)
&& !DECL_INITIAL (p)
&& !b->nested
&& scope != file_scope
&& scope != external_scope)
{
error ("nested function %q+D declared but never defined", p);
undef_nested_function = true;
}
else if (DECL_DECLARED_INLINE_P (p)
&& TREE_PUBLIC (p)
&& !DECL_INITIAL (p))
{
/* C99 6.7.4p6: "a function with external linkage... declared
with an inline function specifier ... shall also be defined
in the same translation unit." */
if (!flag_gnu89_inline
&& !lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (p))
&& scope == external_scope)
pedwarn (input_location, 0,
"inline function %q+D declared but never defined", p);
DECL_EXTERNAL (p) = 1;
}
goto common_symbol;
case VAR_DECL:
/* Warnings for unused variables. */
if ((!TREE_USED (p) || !DECL_READ_P (p))
&& !warning_suppressed_p (p, OPT_Wunused_but_set_variable)
&& !DECL_IN_SYSTEM_HEADER (p)
&& DECL_NAME (p)
&& !DECL_ARTIFICIAL (p)
&& scope != file_scope
&& scope != external_scope)
{
if (!TREE_USED (p))
warning (OPT_Wunused_variable, "unused variable %q+D", p);
else if (DECL_CONTEXT (p) == current_function_decl)
warning_at (DECL_SOURCE_LOCATION (p),
OPT_Wunused_but_set_variable,
"variable %qD set but not used", p);
}
if (b->inner_comp)
{
error ("type of array %q+D completed incompatibly with"
" implicit initialization", p);
}
/* Fall through. */
case TYPE_DECL:
case CONST_DECL:
common_symbol:
/* All of these go in BLOCK_VARS, but only if this is the
binding in the home scope. */
if (!b->nested)
{
DECL_CHAIN (p) = BLOCK_VARS (block);
BLOCK_VARS (block) = p;
}
else if (VAR_OR_FUNCTION_DECL_P (p) && scope != file_scope)
{
/* For block local externs add a special
DECL_EXTERNAL decl for debug info generation. */
tree extp = copy_node (p);
DECL_EXTERNAL (extp) = 1;
TREE_STATIC (extp) = 0;
TREE_PUBLIC (extp) = 1;
DECL_INITIAL (extp) = NULL_TREE;
DECL_LANG_SPECIFIC (extp) = NULL;
DECL_CONTEXT (extp) = current_function_decl;
if (TREE_CODE (p) == FUNCTION_DECL)
{
DECL_RESULT (extp) = NULL_TREE;
DECL_SAVED_TREE (extp) = NULL_TREE;
DECL_STRUCT_FUNCTION (extp) = NULL;
}
if (b->locus != UNKNOWN_LOCATION)
DECL_SOURCE_LOCATION (extp) = b->locus;
DECL_CHAIN (extp) = BLOCK_VARS (block);
BLOCK_VARS (block) = extp;
}
/* If this is the file scope set DECL_CONTEXT of each decl to
the TRANSLATION_UNIT_DECL. This makes same_translation_unit_p
work. */
if (scope == file_scope)
{
DECL_CONTEXT (p) = context;
if (TREE_CODE (p) == TYPE_DECL
&& TREE_TYPE (p) != error_mark_node)
set_type_context (TREE_TYPE (p), context);
}
gcc_fallthrough ();
/* Parameters go in DECL_ARGUMENTS, not BLOCK_VARS, and have
already been put there by store_parm_decls. Unused-
parameter warnings are handled by function.c.
error_mark_node obviously does not go in BLOCK_VARS and
does not get unused-variable warnings. */
case PARM_DECL:
case ERROR_MARK:
/* It is possible for a decl not to have a name. We get
here with b->id NULL in this case. */
if (b->id)
{
gcc_assert (I_SYMBOL_BINDING (b->id) == b);
I_SYMBOL_BINDING (b->id) = b->shadowed;
if (b->shadowed && b->shadowed->u.type)
TREE_TYPE (b->shadowed->decl) = b->shadowed->u.type;
}
break;
default:
gcc_unreachable ();
}
}
/* Dispose of the block that we just made inside some higher level. */
if ((scope->function_body || scope == file_scope) && context)
{
DECL_INITIAL (context) = block;
BLOCK_SUPERCONTEXT (block) = context;
}
else if (scope->outer)
{
if (block)
SCOPE_LIST_APPEND (scope->outer, blocks, block);
/* If we did not make a block for the scope just exited, any
blocks made for inner scopes must be carried forward so they
will later become subblocks of something else. */
else if (scope->blocks)
SCOPE_LIST_CONCAT (scope->outer, blocks, scope, blocks);
}
/* Pop the current scope, and free the structure for reuse. */
current_scope = scope->outer;
if (scope->function_body)
current_function_scope = scope->outer_function;
memset (scope, 0, sizeof (struct c_scope));
scope->outer = scope_freelist;
scope_freelist = scope;
return block;
}
void
push_file_scope (void)
{
tree decl;
if (file_scope)
return;
push_scope ();
file_scope = current_scope;
start_fname_decls ();
for (decl = visible_builtins; decl; decl = DECL_CHAIN (decl))
bind (DECL_NAME (decl), decl, file_scope,
/*invisible=*/false, /*nested=*/true, DECL_SOURCE_LOCATION (decl));
}
void
pop_file_scope (void)
{
/* In case there were missing closebraces, get us back to the global
binding level. */
while (current_scope != file_scope)
pop_scope ();
/* __FUNCTION__ is defined at file scope (""). This
call may not be necessary as my tests indicate it
still works without it. */
finish_fname_decls ();
check_inline_statics ();
/* This is the point to write out a PCH if we're doing that.
In that case we do not want to do anything else. */
if (pch_file)
{
c_common_write_pch ();
/* Ensure even the callers don't try to finalize the CU. */
flag_syntax_only = 1;
return;
}
/* Pop off the file scope and close this translation unit. */
pop_scope ();
file_scope = 0;
maybe_apply_pending_pragma_weaks ();
}
/* Adjust the bindings for the start of a statement expression. */
void
c_bindings_start_stmt_expr (struct c_spot_bindings* switch_bindings)
{
struct c_scope *scope;
for (scope = current_scope; scope != NULL; scope = scope->outer)
{
struct c_binding *b;
if (!scope->has_label_bindings)
continue;
for (b = scope->bindings; b != NULL; b = b->prev)
{
struct c_label_vars *label_vars;
unsigned int ix;
struct c_goto_bindings *g;
if (TREE_CODE (b->decl) != LABEL_DECL)
continue;
label_vars = b->u.label;
++label_vars->label_bindings.stmt_exprs;
FOR_EACH_VEC_SAFE_ELT (label_vars->gotos, ix, g)
++g->goto_bindings.stmt_exprs;
}
}
if (switch_bindings != NULL)
++switch_bindings->stmt_exprs;
}
/* Adjust the bindings for the end of a statement expression. */
void
c_bindings_end_stmt_expr (struct c_spot_bindings *switch_bindings)
{
struct c_scope *scope;
for (scope = current_scope; scope != NULL; scope = scope->outer)
{
struct c_binding *b;
if (!scope->has_label_bindings)
continue;
for (b = scope->bindings; b != NULL; b = b->prev)
{
struct c_label_vars *label_vars;
unsigned int ix;
struct c_goto_bindings *g;
if (TREE_CODE (b->decl) != LABEL_DECL)
continue;
label_vars = b->u.label;
--label_vars->label_bindings.stmt_exprs;
if (label_vars->label_bindings.stmt_exprs < 0)
{
label_vars->label_bindings.left_stmt_expr = true;
label_vars->label_bindings.stmt_exprs = 0;
}
FOR_EACH_VEC_SAFE_ELT (label_vars->gotos, ix, g)
{
--g->goto_bindings.stmt_exprs;
if (g->goto_bindings.stmt_exprs < 0)
{
g->goto_bindings.left_stmt_expr = true;
g->goto_bindings.stmt_exprs = 0;
}
}
}
}
if (switch_bindings != NULL)
{
--switch_bindings->stmt_exprs;
gcc_assert (switch_bindings->stmt_exprs >= 0);
}
}
/* Push a definition or a declaration of struct, union or enum tag "name".
"type" should be the type node.
We assume that the tag "name" is not already defined, and has a location
of LOC.
Note that the definition may really be just a forward reference.
In that case, the TYPE_SIZE will be zero. */
static void
pushtag (location_t loc, tree name, tree type)
{
/* Record the identifier as the type's name if it has none. */
if (name && !TYPE_NAME (type))
TYPE_NAME (type) = name;
bind (name, type, current_scope, /*invisible=*/false, /*nested=*/false, loc);
/* Create a fake NULL-named TYPE_DECL node whose TREE_TYPE will be the
tagged type we just added to the current scope. This fake
NULL-named TYPE_DECL node helps dwarfout.c to know when it needs
to output a representation of a tagged type, and it also gives
us a convenient place to record the "scope start" address for the
tagged type. */
TYPE_STUB_DECL (type) = pushdecl (build_decl (loc,
TYPE_DECL, NULL_TREE, type));
/* An approximation for now, so we can tell this is a function-scope tag.
This will be updated in pop_scope. */
TYPE_CONTEXT (type) = DECL_CONTEXT (TYPE_STUB_DECL (type));
if (warn_cxx_compat && name != NULL_TREE)
{
struct c_binding *b = I_SYMBOL_BINDING (name);
if (b != NULL
&& b->decl != NULL_TREE
&& TREE_CODE (b->decl) == TYPE_DECL
&& (B_IN_CURRENT_SCOPE (b)
|| (current_scope == file_scope && B_IN_EXTERNAL_SCOPE (b)))
&& (TYPE_MAIN_VARIANT (TREE_TYPE (b->decl))
!= TYPE_MAIN_VARIANT (type)))
{
auto_diagnostic_group d;
if (warning_at (loc, OPT_Wc___compat,
("using %qD as both a typedef and a tag is "
"invalid in C++"), b->decl)
&& b->locus != UNKNOWN_LOCATION)
inform (b->locus, "originally defined here");
}
}
}
/* An exported interface to pushtag. This is used by the gdb plugin's
binding oracle to introduce a new tag binding. */
void
c_pushtag (location_t loc, tree name, tree type)
{
pushtag (loc, name, type);
}
/* An exported interface to bind a declaration. LOC is the location
to use. DECL is the declaration to bind. The decl's name is used
to determine how it is bound. If DECL is a VAR_DECL, then
IS_GLOBAL determines whether the decl is put into the global (file
and external) scope or the current function's scope; if DECL is not
a VAR_DECL then it is always put into the file scope. */
void
c_bind (location_t loc, tree decl, bool is_global)
{
struct c_scope *scope;
bool nested = false;
if (!VAR_P (decl) || current_function_scope == NULL)
{
/* Types and functions are always considered to be global. */
scope = file_scope;
DECL_EXTERNAL (decl) = 1;
TREE_PUBLIC (decl) = 1;
}
else if (is_global)
{
/* Also bind it into the external scope. */
bind (DECL_NAME (decl), decl, external_scope, true, false, loc);
nested = true;
scope = file_scope;
DECL_EXTERNAL (decl) = 1;
TREE_PUBLIC (decl) = 1;
}
else
{
DECL_CONTEXT (decl) = current_function_decl;
TREE_PUBLIC (decl) = 0;
scope = current_function_scope;
}
bind (DECL_NAME (decl), decl, scope, false, nested, loc);
}
/* Stores the first FILE*, const struct tm* etc. argument type (whatever
it is) seen in a declaration of a file I/O etc. built-in, corresponding
to the builtin_structptr_types array. Subsequent declarations of such
built-ins are expected to refer to it rather than to fileptr_type_node,
etc. which is just void* (or to any other type).
Used only by match_builtin_function_types. */
static const unsigned builtin_structptr_type_count
= sizeof builtin_structptr_types / sizeof builtin_structptr_types[0];
static GTY(()) tree last_structptr_types[builtin_structptr_type_count];
/* Returns true if types T1 and T2 representing return types or types
of function arguments are close enough to be considered interchangeable
in redeclarations of built-in functions. */
static bool
types_close_enough_to_match (tree t1, tree t2)
{
return (TYPE_MODE (t1) == TYPE_MODE (t2)
&& POINTER_TYPE_P (t1) == POINTER_TYPE_P (t2)
&& FUNCTION_POINTER_TYPE_P (t1) == FUNCTION_POINTER_TYPE_P (t2));
}
/* Subroutine of compare_decls. Allow harmless mismatches in return
and argument types provided that the type modes match. Set *STRICT
and *ARGNO to the expected argument type and number in case of
an argument type mismatch or null and zero otherwise. Return
a unified type given a suitable match, and 0 otherwise. */
static tree
match_builtin_function_types (tree newtype, tree oldtype,
tree *strict, unsigned *argno)
{
*argno = 0;
*strict = NULL_TREE;
/* Accept the return type of the new declaration if it has the same
mode and if they're both pointers or if neither is. */
tree oldrettype = TREE_TYPE (oldtype);
tree newrettype = TREE_TYPE (newtype);
if (!types_close_enough_to_match (oldrettype, newrettype))
return NULL_TREE;
/* Check that the return types are compatible but don't fail if they
are not (e.g., int vs long in ILP32) and just let the caller know. */
if (!comptypes (TYPE_MAIN_VARIANT (oldrettype),
TYPE_MAIN_VARIANT (newrettype)))
*strict = oldrettype;
tree oldargs = TYPE_ARG_TYPES (oldtype);
tree newargs = TYPE_ARG_TYPES (newtype);
tree tryargs = newargs;
const unsigned nlst
= sizeof last_structptr_types / sizeof last_structptr_types[0];
const unsigned nbst
= sizeof builtin_structptr_types / sizeof builtin_structptr_types[0];
gcc_checking_assert (nlst == nbst);
for (unsigned i = 1; oldargs || newargs; ++i)
{
if (!oldargs
|| !newargs
|| !TREE_VALUE (oldargs)
|| !TREE_VALUE (newargs))
return NULL_TREE;
tree oldtype = TYPE_MAIN_VARIANT (TREE_VALUE (oldargs));
tree newtype = TREE_VALUE (newargs);
if (newtype == error_mark_node)
return NULL_TREE;
newtype = TYPE_MAIN_VARIANT (newtype);
if (!types_close_enough_to_match (oldtype, newtype))
return NULL_TREE;
unsigned j = nbst;
if (POINTER_TYPE_P (oldtype))
/* Iterate over well-known struct types like FILE (whose types
aren't known to us) and compare the pointer to each to
the pointer argument. */
for (j = 0; j < nbst; ++j)
{
if (TREE_VALUE (oldargs) != builtin_structptr_types[j].node)
continue;
/* Store the first FILE* etc. argument type (whatever it is), and
expect any subsequent declarations of file I/O etc. built-ins
to refer to it rather than to fileptr_type_node etc. which is
just void* (or const void*). */
if (last_structptr_types[j])
{
if (!comptypes (last_structptr_types[j], newtype))
{
*argno = i;
*strict = last_structptr_types[j];
}
}
else
last_structptr_types[j] = newtype;
break;
}
if (j == nbst && !comptypes (oldtype, newtype))
{
if (POINTER_TYPE_P (oldtype))
{
/* For incompatible pointers, only reject differences in
the unqualified variants of the referenced types but
consider differences in qualifiers as benign (report
those to caller via *STRICT below). */
tree oldref = TYPE_MAIN_VARIANT (TREE_TYPE (oldtype));
tree newref = TYPE_MAIN_VARIANT (TREE_TYPE (newtype));
if (!comptypes (oldref, newref))
return NULL_TREE;
}
if (!*strict)
{
*argno = i;
*strict = oldtype;
}
}
oldargs = TREE_CHAIN (oldargs);
newargs = TREE_CHAIN (newargs);
}
tree trytype = build_function_type (newrettype, tryargs);
/* Allow declaration to change transaction_safe attribute. */
tree oldattrs = TYPE_ATTRIBUTES (oldtype);
tree oldtsafe = lookup_attribute ("transaction_safe", oldattrs);
tree newattrs = TYPE_ATTRIBUTES (newtype);
tree newtsafe = lookup_attribute ("transaction_safe", newattrs);
if (oldtsafe && !newtsafe)
oldattrs = remove_attribute ("transaction_safe", oldattrs);
else if (newtsafe && !oldtsafe)
oldattrs = tree_cons (get_identifier ("transaction_safe"),
NULL_TREE, oldattrs);
return build_type_attribute_variant (trytype, oldattrs);
}
/* Subroutine of diagnose_mismatched_decls. Check for function type
mismatch involving an empty arglist vs a nonempty one and give clearer
diagnostics. */
static void
diagnose_arglist_conflict (tree newdecl, tree olddecl,
tree newtype, tree oldtype)
{
tree t;
if (TREE_CODE (olddecl) != FUNCTION_DECL
|| !comptypes (TREE_TYPE (oldtype), TREE_TYPE (newtype))
|| !((!prototype_p (oldtype) && DECL_INITIAL (olddecl) == NULL_TREE)
|| (!prototype_p (newtype) && DECL_INITIAL (newdecl) == NULL_TREE)))
return;
t = TYPE_ARG_TYPES (oldtype);
if (t == NULL_TREE)
t = TYPE_ARG_TYPES (newtype);
for (; t; t = TREE_CHAIN (t))
{
tree type = TREE_VALUE (t);
if (TREE_CHAIN (t) == NULL_TREE
&& TYPE_MAIN_VARIANT (type) != void_type_node)
{
inform (input_location, "a parameter list with an ellipsis "
"cannot match an empty parameter name list declaration");
break;
}
if (c_type_promotes_to (type) != type)
{
inform (input_location, "an argument type that has a default "
"promotion cannot match an empty parameter name list "
"declaration");
break;
}
}
}
/* Another subroutine of diagnose_mismatched_decls. OLDDECL is an
old-style function definition, NEWDECL is a prototype declaration.
Diagnose inconsistencies in the argument list. Returns TRUE if
the prototype is compatible, FALSE if not. */
static bool
validate_proto_after_old_defn (tree newdecl, tree newtype, tree oldtype)
{
tree newargs, oldargs;
int i;
#define END_OF_ARGLIST(t) ((t) == void_type_node)
oldargs = TYPE_ACTUAL_ARG_TYPES (oldtype);
newargs = TYPE_ARG_TYPES (newtype);
i = 1;
for (;;)
{
tree oldargtype = TREE_VALUE (oldargs);
tree newargtype = TREE_VALUE (newargs);
if (oldargtype == error_mark_node || newargtype == error_mark_node)
return false;
oldargtype = (TYPE_ATOMIC (oldargtype)
? c_build_qualified_type (TYPE_MAIN_VARIANT (oldargtype),
TYPE_QUAL_ATOMIC)
: TYPE_MAIN_VARIANT (oldargtype));
newargtype = (TYPE_ATOMIC (newargtype)
? c_build_qualified_type (TYPE_MAIN_VARIANT (newargtype),
TYPE_QUAL_ATOMIC)
: TYPE_MAIN_VARIANT (newargtype));
if (END_OF_ARGLIST (oldargtype) && END_OF_ARGLIST (newargtype))
break;
/* Reaching the end of just one list means the two decls don't
agree on the number of arguments. */
if (END_OF_ARGLIST (oldargtype))
{
error ("prototype for %q+D declares more arguments "
"than previous old-style definition", newdecl);
return false;
}
else if (END_OF_ARGLIST (newargtype))
{
error ("prototype for %q+D declares fewer arguments "
"than previous old-style definition", newdecl);
return false;
}
/* Type for passing arg must be consistent with that declared
for the arg. */
else if (!comptypes (oldargtype, newargtype))
{
error ("prototype for %q+D declares argument %d"
" with incompatible type",
newdecl, i);
return false;
}
oldargs = TREE_CHAIN (oldargs);
newargs = TREE_CHAIN (newargs);
i++;
}
/* If we get here, no errors were found, but do issue a warning
for this poor-style construct. */
warning (0, "prototype for %q+D follows non-prototype definition",
newdecl);
return true;
#undef END_OF_ARGLIST
}
/* Subroutine of diagnose_mismatched_decls. Report the location of DECL,
first in a pair of mismatched declarations, using the diagnostic
function DIAG. */
static void
locate_old_decl (tree decl)
{
if (TREE_CODE (decl) == FUNCTION_DECL
&& fndecl_built_in_p (decl)
&& !C_DECL_DECLARED_BUILTIN (decl))
;
else if (DECL_INITIAL (decl))
inform (input_location,
"previous definition of %q+D with type %qT",
decl, TREE_TYPE (decl));
else if (C_DECL_IMPLICIT (decl))
inform (input_location,
"previous implicit declaration of %q+D with type %qT",
decl, TREE_TYPE (decl));
else
inform (input_location,
"previous declaration of %q+D with type %qT",
decl, TREE_TYPE (decl));
}
/* Subroutine of duplicate_decls. Compare NEWDECL to OLDDECL.
Returns true if the caller should proceed to merge the two, false
if OLDDECL should simply be discarded. As a side effect, issues
all necessary diagnostics for invalid or poor-style combinations.
If it returns true, writes the types of NEWDECL and OLDDECL to
*NEWTYPEP and *OLDTYPEP - these may have been adjusted from
TREE_TYPE (NEWDECL, OLDDECL) respectively. */
static bool
diagnose_mismatched_decls (tree newdecl, tree olddecl,
tree *newtypep, tree *oldtypep)
{
tree newtype, oldtype;
bool retval = true;
#define DECL_EXTERN_INLINE(DECL) (DECL_DECLARED_INLINE_P (DECL) \
&& DECL_EXTERNAL (DECL))
/* If we have error_mark_node for either decl or type, just discard
the previous decl - we're in an error cascade already. */
if (olddecl == error_mark_node || newdecl == error_mark_node)
return false;
*oldtypep = oldtype = TREE_TYPE (olddecl);
*newtypep = newtype = TREE_TYPE (newdecl);
if (oldtype == error_mark_node || newtype == error_mark_node)
return false;
/* Two different categories of symbol altogether. This is an error
unless OLDDECL is a builtin. OLDDECL will be discarded in any case. */
if (TREE_CODE (olddecl) != TREE_CODE (newdecl))
{
if (!(TREE_CODE (olddecl) == FUNCTION_DECL
&& fndecl_built_in_p (olddecl)
&& !C_DECL_DECLARED_BUILTIN (olddecl)))
{
auto_diagnostic_group d;
error ("%q+D redeclared as different kind of symbol", newdecl);
locate_old_decl (olddecl);
}
else if (TREE_PUBLIC (newdecl))
warning (OPT_Wbuiltin_declaration_mismatch,
"built-in function %q+D declared as non-function",
newdecl);
else
warning (OPT_Wshadow, "declaration of %q+D shadows "
"a built-in function", newdecl);
return false;
}
/* Enumerators have no linkage, so may only be declared once in a
given scope. */
if (TREE_CODE (olddecl) == CONST_DECL)
{
auto_diagnostic_group d;
error ("redeclaration of enumerator %q+D", newdecl);
locate_old_decl (olddecl);
return false;
}
bool pedwarned = false;
bool warned = false;
auto_diagnostic_group d;
if (!comptypes (oldtype, newtype))
{
if (TREE_CODE (olddecl) == FUNCTION_DECL
&& fndecl_built_in_p (olddecl, BUILT_IN_NORMAL)
&& !C_DECL_DECLARED_BUILTIN (olddecl))
{
/* Accept "harmless" mismatches in function types such
as missing qualifiers or int vs long when they're the same
size. However, diagnose return and argument types that are
incompatible according to language rules. */
tree mismatch_expect;
unsigned mismatch_argno;
tree trytype = match_builtin_function_types (newtype, oldtype,
&mismatch_expect,
&mismatch_argno);
if (trytype && comptypes (newtype, trytype))
*oldtypep = oldtype = trytype;
else
{
/* If types don't match for a built-in, throw away the
built-in. No point in calling locate_old_decl here, it
won't print anything. */
const char *header = header_for_builtin_fn (olddecl);
location_t loc = DECL_SOURCE_LOCATION (newdecl);
if (warning_at (loc, OPT_Wbuiltin_declaration_mismatch,
"conflicting types for built-in function %q+D; "
"expected %qT",
newdecl, oldtype)
&& header)
{
/* Suggest the right header to include as the preferred
solution rather than the spelling of the declaration. */
rich_location richloc (line_table, loc);
maybe_add_include_fixit (&richloc, header, true);
inform (&richloc,
"%qD is declared in header %qs", olddecl, header);
}
return false;
}
if (mismatch_expect && extra_warnings)
{
location_t newloc = DECL_SOURCE_LOCATION (newdecl);
bool warned = false;
if (mismatch_argno)
warned = warning_at (newloc, OPT_Wbuiltin_declaration_mismatch,
"mismatch in argument %u type of built-in "
"function %qD; expected %qT",
mismatch_argno, newdecl, mismatch_expect);
else
warned = warning_at (newloc, OPT_Wbuiltin_declaration_mismatch,
"mismatch in return type of built-in "
"function %qD; expected %qT",
newdecl, mismatch_expect);
const char *header = header_for_builtin_fn (olddecl);
if (warned && header)
{
rich_location richloc (line_table, newloc);
maybe_add_include_fixit (&richloc, header, true);
inform (&richloc,
"%qD is declared in header %qs", olddecl, header);
}
}
}
else if (TREE_CODE (olddecl) == FUNCTION_DECL
&& DECL_IS_UNDECLARED_BUILTIN (olddecl))
{
/* A conflicting function declaration for a predeclared
function that isn't actually built in. Objective C uses
these. The new declaration silently overrides everything
but the volatility (i.e. noreturn) indication. See also
below. FIXME: Make Objective C use normal builtins. */
TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl);
return false;
}
/* Permit void foo (...) to match int foo (...) if the latter is
the definition and implicit int was used. See
c-torture/compile/920625-2.c. */
else if (TREE_CODE (newdecl) == FUNCTION_DECL && DECL_INITIAL (newdecl)
&& TYPE_MAIN_VARIANT (TREE_TYPE (oldtype)) == void_type_node
&& TYPE_MAIN_VARIANT (TREE_TYPE (newtype)) == integer_type_node
&& C_FUNCTION_IMPLICIT_INT (newdecl) && !DECL_INITIAL (olddecl))
{
pedwarned = pedwarn (input_location, 0,
"conflicting types for %q+D", newdecl);
/* Make sure we keep void as the return type. */
TREE_TYPE (newdecl) = *newtypep = newtype = oldtype;
C_FUNCTION_IMPLICIT_INT (newdecl) = 0;
}
/* Permit void foo (...) to match an earlier call to foo (...) with
no declared type (thus, implicitly int). */
else if (TREE_CODE (newdecl) == FUNCTION_DECL
&& TYPE_MAIN_VARIANT (TREE_TYPE (newtype)) == void_type_node
&& TYPE_MAIN_VARIANT (TREE_TYPE (oldtype)) == integer_type_node
&& C_DECL_IMPLICIT (olddecl) && !DECL_INITIAL (olddecl))
{
pedwarned = pedwarn (input_location, 0,
"conflicting types for %q+D; have %qT",
newdecl, newtype);
/* Make sure we keep void as the return type. */
TREE_TYPE (olddecl) = *oldtypep = oldtype = newtype;
}
else
{
int new_quals = TYPE_QUALS (newtype);
int old_quals = TYPE_QUALS (oldtype);
if (new_quals != old_quals)
{
addr_space_t new_addr = DECODE_QUAL_ADDR_SPACE (new_quals);
addr_space_t old_addr = DECODE_QUAL_ADDR_SPACE (old_quals);
if (new_addr != old_addr)
{
if (ADDR_SPACE_GENERIC_P (new_addr))
error ("conflicting named address spaces (generic vs %s) "
"for %q+D",
c_addr_space_name (old_addr), newdecl);
else if (ADDR_SPACE_GENERIC_P (old_addr))
error ("conflicting named address spaces (%s vs generic) "
"for %q+D",
c_addr_space_name (new_addr), newdecl);
else
error ("conflicting named address spaces (%s vs %s) "
"for %q+D",
c_addr_space_name (new_addr),
c_addr_space_name (old_addr),
newdecl);
}
if (CLEAR_QUAL_ADDR_SPACE (new_quals)
!= CLEAR_QUAL_ADDR_SPACE (old_quals))
error ("conflicting type qualifiers for %q+D", newdecl);
}
else
error ("conflicting types for %q+D; have %qT", newdecl, newtype);
diagnose_arglist_conflict (newdecl, olddecl, newtype, oldtype);
locate_old_decl (olddecl);
return false;
}
}
/* Redeclaration of a type is a constraint violation (6.7.2.3p1),
but silently ignore the redeclaration if either is in a system
header. (Conflicting redeclarations were handled above.) This
is allowed for C11 if the types are the same, not just
compatible. */
if (TREE_CODE (newdecl) == TYPE_DECL)
{
bool types_different = false;
int comptypes_result;
comptypes_result
= comptypes_check_different_types (oldtype, newtype, &types_different);
if (comptypes_result != 1 || types_different)
{
error ("redefinition of typedef %q+D with different type", newdecl);
locate_old_decl (olddecl);
return false;
}
if (DECL_IN_SYSTEM_HEADER (newdecl)
|| DECL_IN_SYSTEM_HEADER (olddecl)
|| warning_suppressed_p (newdecl, OPT_Wpedantic)
|| warning_suppressed_p (olddecl, OPT_Wpedantic))
return true; /* Allow OLDDECL to continue in use. */
if (variably_modified_type_p (newtype, NULL))
{
error ("redefinition of typedef %q+D with variably modified type",
newdecl);
locate_old_decl (olddecl);
}
else if (pedwarn_c99 (input_location, OPT_Wpedantic,
"redefinition of typedef %q+D", newdecl))
locate_old_decl (olddecl);
return true;
}
/* Function declarations can either be 'static' or 'extern' (no
qualifier is equivalent to 'extern' - C99 6.2.2p5) and therefore
can never conflict with each other on account of linkage
(6.2.2p4). Multiple definitions are not allowed (6.9p3,5) but
gnu89 mode permits two definitions if one is 'extern inline' and
one is not. The non- extern-inline definition supersedes the
extern-inline definition. */
else if (TREE_CODE (newdecl) == FUNCTION_DECL)
{
/* If you declare a built-in function name as static, or
define the built-in with an old-style definition (so we
can't validate the argument list) the built-in definition is
overridden, but optionally warn this was a bad choice of name. */
if (fndecl_built_in_p (olddecl)
&& !C_DECL_DECLARED_BUILTIN (olddecl))
{
if (!TREE_PUBLIC (newdecl)
|| (DECL_INITIAL (newdecl)
&& !prototype_p (TREE_TYPE (newdecl))))
{
warning_at (DECL_SOURCE_LOCATION (newdecl),
OPT_Wshadow, "declaration of %qD shadows "
"a built-in function", newdecl);
/* Discard the old built-in function. */
return false;
}
if (!prototype_p (TREE_TYPE (newdecl)))
{
/* Set for built-ins that take no arguments. */
bool func_void_args = false;
if (tree at = TYPE_ARG_TYPES (oldtype))
func_void_args = VOID_TYPE_P (TREE_VALUE (at));
if (extra_warnings && !func_void_args)
warning_at (DECL_SOURCE_LOCATION (newdecl),
OPT_Wbuiltin_declaration_mismatch,
"declaration of built-in function %qD without "
"a prototype; expected %qT",
newdecl, TREE_TYPE (olddecl));
}
}
if (DECL_INITIAL (newdecl))
{
if (DECL_INITIAL (olddecl))
{
/* If both decls are in the same TU and the new declaration
isn't overriding an extern inline reject the new decl.
In c99, no overriding is allowed in the same translation
unit. */
if ((!DECL_EXTERN_INLINE (olddecl)
|| DECL_EXTERN_INLINE (newdecl)
|| (!flag_gnu89_inline
&& (!DECL_DECLARED_INLINE_P (olddecl)
|| !lookup_attribute ("gnu_inline",
DECL_ATTRIBUTES (olddecl)))
&& (!DECL_DECLARED_INLINE_P (newdecl)
|| !lookup_attribute ("gnu_inline",
DECL_ATTRIBUTES (newdecl))))
)
&& same_translation_unit_p (newdecl, olddecl))
{
auto_diagnostic_group d;
error ("redefinition of %q+D", newdecl);
locate_old_decl (olddecl);
return false;
}
}
}
/* If we have a prototype after an old-style function definition,
the argument types must be checked specially. */
else if (DECL_INITIAL (olddecl)
&& !prototype_p (oldtype) && prototype_p (newtype)
&& TYPE_ACTUAL_ARG_TYPES (oldtype))
{
auto_diagnostic_group d;
if (!validate_proto_after_old_defn (newdecl, newtype, oldtype))
{
locate_old_decl (olddecl);
return false;
}
}
/* A non-static declaration (even an "extern") followed by a
static declaration is undefined behavior per C99 6.2.2p3-5,7.
The same is true for a static forward declaration at block
scope followed by a non-static declaration/definition at file
scope. Static followed by non-static at the same scope is
not undefined behavior, and is the most convenient way to get
some effects (see e.g. what unwind-dw2-fde-glibc.c does to
the definition of _Unwind_Find_FDE in unwind-dw2-fde.c), but
we do diagnose it if -Wtraditional. */
if (TREE_PUBLIC (olddecl) && !TREE_PUBLIC (newdecl))
{
/* Two exceptions to the rule. If olddecl is an extern
inline, or a predeclared function that isn't actually
built in, newdecl silently overrides olddecl. The latter
occur only in Objective C; see also above. (FIXME: Make
Objective C use normal builtins.) */
if (!DECL_IS_UNDECLARED_BUILTIN (olddecl)
&& !DECL_EXTERN_INLINE (olddecl))
{
auto_diagnostic_group d;
error ("static declaration of %q+D follows "
"non-static declaration", newdecl);
locate_old_decl (olddecl);
}
return false;
}
else if (TREE_PUBLIC (newdecl) && !TREE_PUBLIC (olddecl))
{
if (DECL_CONTEXT (olddecl))
{
auto_diagnostic_group d;
error ("non-static declaration of %q+D follows "
"static declaration", newdecl);
locate_old_decl (olddecl);
return false;
}
else if (warn_traditional)
{
warned |= warning (OPT_Wtraditional,
"non-static declaration of %q+D "
"follows static declaration", newdecl);
}
}
/* Make sure gnu_inline attribute is either not present, or
present on all inline decls. */
if (DECL_DECLARED_INLINE_P (olddecl)
&& DECL_DECLARED_INLINE_P (newdecl))
{
bool newa = lookup_attribute ("gnu_inline",
DECL_ATTRIBUTES (newdecl)) != NULL;
bool olda = lookup_attribute ("gnu_inline",
DECL_ATTRIBUTES (olddecl)) != NULL;
if (newa != olda)
{
auto_diagnostic_group d;
error_at (input_location, "%<gnu_inline%> attribute present on %q+D",
newa ? newdecl : olddecl);
error_at (DECL_SOURCE_LOCATION (newa ? olddecl : newdecl),
"but not here");
}
}
}
else if (VAR_P (newdecl))
{
/* Only variables can be thread-local, and all declarations must
agree on this property. */
if (C_DECL_THREADPRIVATE_P (olddecl) && !DECL_THREAD_LOCAL_P (newdecl))
{
/* Nothing to check. Since OLDDECL is marked threadprivate
and NEWDECL does not have a thread-local attribute, we
will merge the threadprivate attribute into NEWDECL. */
;
}
else if (DECL_THREAD_LOCAL_P (newdecl) != DECL_THREAD_LOCAL_P (olddecl))
{
auto_diagnostic_group d;
if (DECL_THREAD_LOCAL_P (newdecl))
error ("thread-local declaration of %q+D follows "
"non-thread-local declaration", newdecl);
else
error ("non-thread-local declaration of %q+D follows "
"thread-local declaration", newdecl);
locate_old_decl (olddecl);
return false;
}
/* Multiple initialized definitions are not allowed (6.9p3,5). */
if (DECL_INITIAL (newdecl) && DECL_INITIAL (olddecl))
{
auto_diagnostic_group d;
error ("redefinition of %q+D", newdecl);
locate_old_decl (olddecl);
return false;
}
/* Objects declared at file scope: if the first declaration had
external linkage (even if it was an external reference) the
second must have external linkage as well, or the behavior is
undefined. If the first declaration had internal linkage, then
the second must too, or else be an external reference (in which
case the composite declaration still has internal linkage).
As for function declarations, we warn about the static-then-
extern case only for -Wtraditional. See generally 6.2.2p3-5,7. */
if (DECL_FILE_SCOPE_P (newdecl)
&& TREE_PUBLIC (newdecl) != TREE_PUBLIC (olddecl))
{
if (DECL_EXTERNAL (newdecl))
{
if (!DECL_FILE_SCOPE_P (olddecl))
{
auto_diagnostic_group d;
error ("extern declaration of %q+D follows "
"declaration with no linkage", newdecl);
locate_old_decl (olddecl);
return false;
}
else if (warn_traditional)
{
warned |= warning (OPT_Wtraditional,
"non-static declaration of %q+D "
"follows static declaration", newdecl);
}
}
else
{
auto_diagnostic_group d;
if (TREE_PUBLIC (newdecl))
error ("non-static declaration of %q+D follows "
"static declaration", newdecl);
else
error ("static declaration of %q+D follows "
"non-static declaration", newdecl);
locate_old_decl (olddecl);
return false;
}
}
/* Two objects with the same name declared at the same block
scope must both be external references (6.7p3). */
else if (!DECL_FILE_SCOPE_P (newdecl))
{
if (DECL_EXTERNAL (newdecl))
{
/* Extern with initializer at block scope, which will
already have received an error. */
}
else if (DECL_EXTERNAL (olddecl))
{
auto_diagnostic_group d;
error ("declaration of %q+D with no linkage follows "
"extern declaration", newdecl);
locate_old_decl (olddecl);
}
else
{
auto_diagnostic_group d;
error ("redeclaration of %q+D with no linkage", newdecl);
locate_old_decl (olddecl);
}
return false;
}
/* C++ does not permit a decl to appear multiple times at file
scope. */
if (warn_cxx_compat
&& DECL_FILE_SCOPE_P (newdecl)
&& !DECL_EXTERNAL (newdecl)
&& !DECL_EXTERNAL (olddecl))
warned |= warning_at (DECL_SOURCE_LOCATION (newdecl),
OPT_Wc___compat,
("duplicate declaration of %qD is "
"invalid in C++"),
newdecl);
}
/* warnings */
/* All decls must agree on a visibility. */
if (CODE_CONTAINS_STRUCT (TREE_CODE (newdecl), TS_DECL_WITH_VIS)
&& DECL_VISIBILITY_SPECIFIED (newdecl) && DECL_VISIBILITY_SPECIFIED (olddecl)
&& DECL_VISIBILITY (newdecl) != DECL_VISIBILITY (olddecl))
{
warned |= warning (0, "redeclaration of %q+D with different visibility "
"(old visibility preserved)", newdecl);
}
if (TREE_CODE (newdecl) == FUNCTION_DECL)
warned |= diagnose_mismatched_attributes (olddecl, newdecl);
else /* PARM_DECL, VAR_DECL */
{
/* Redeclaration of a parameter is a constraint violation (this is
not explicitly stated, but follows from C99 6.7p3 [no more than
one declaration of the same identifier with no linkage in the
same scope, except type tags] and 6.2.2p6 [parameters have no
linkage]). We must check for a forward parameter declaration,
indicated by TREE_ASM_WRITTEN on the old declaration - this is
an extension, the mandatory diagnostic for which is handled by
mark_forward_parm_decls. */
if (TREE_CODE (newdecl) == PARM_DECL
&& (!TREE_ASM_WRITTEN (olddecl) || TREE_ASM_WRITTEN (newdecl)))
{
auto_diagnostic_group d;
error ("redefinition of parameter %q+D", newdecl);
locate_old_decl (olddecl);
return false;
}
}
/* Optional warning for completely redundant decls. */
if (!warned && !pedwarned
&& warn_redundant_decls
/* Don't warn about a function declaration followed by a
definition. */
&& !(TREE_CODE (newdecl) == FUNCTION_DECL
&& DECL_INITIAL (newdecl) && !DECL_INITIAL (olddecl))
/* Don't warn about redundant redeclarations of builtins. */
&& !(TREE_CODE (newdecl) == FUNCTION_DECL
&& !fndecl_built_in_p (newdecl)
&& fndecl_built_in_p (olddecl)
&& !C_DECL_DECLARED_BUILTIN (olddecl))
/* Don't warn about an extern followed by a definition. */
&& !(DECL_EXTERNAL (olddecl) && !DECL_EXTERNAL (newdecl))
/* Don't warn about forward parameter decls. */
&& !(TREE_CODE (newdecl) == PARM_DECL
&& TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl))
/* Don't warn about a variable definition following a declaration. */
&& !(VAR_P (newdecl)
&& DECL_INITIAL (newdecl) && !DECL_INITIAL (olddecl)))
{
warned = warning (OPT_Wredundant_decls, "redundant redeclaration of %q+D",
newdecl);
}
/* Report location of previous decl/defn. */
if (warned || pedwarned)
locate_old_decl (olddecl);
#undef DECL_EXTERN_INLINE
return retval;
}
/* Subroutine of duplicate_decls. NEWDECL has been found to be
consistent with OLDDECL, but carries new information. Merge the
new information into OLDDECL. This function issues no
diagnostics. */
static void
merge_decls (tree newdecl, tree olddecl, tree newtype, tree oldtype)
{
bool new_is_definition = (TREE_CODE (newdecl) == FUNCTION_DECL
&& DECL_INITIAL (newdecl) != NULL_TREE);
bool new_is_prototype = (TREE_CODE (newdecl) == FUNCTION_DECL
&& prototype_p (TREE_TYPE (newdecl)));
bool old_is_prototype = (TREE_CODE (olddecl) == FUNCTION_DECL
&& prototype_p (TREE_TYPE (olddecl)));
/* For real parm decl following a forward decl, rechain the old decl
in its new location and clear TREE_ASM_WRITTEN (it's not a
forward decl anymore). */
if (TREE_CODE (newdecl) == PARM_DECL
&& TREE_ASM_WRITTEN (olddecl) && !TREE_ASM_WRITTEN (newdecl))
{
struct c_binding *b, **here;
for (here = &current_scope->bindings; *here; here = &(*here)->prev)
if ((*here)->decl == olddecl)
goto found;
gcc_unreachable ();
found:
b = *here;
*here = b->prev;
b->prev = current_scope->bindings;
current_scope->bindings = b;
TREE_ASM_WRITTEN (olddecl) = 0;
}
DECL_ATTRIBUTES (newdecl)
= targetm.merge_decl_attributes (olddecl, newdecl);
/* For typedefs use the old type, as the new type's DECL_NAME points
at newdecl, which will be ggc_freed. */
if (TREE_CODE (newdecl) == TYPE_DECL)
{
/* But NEWTYPE might have an attribute, honor that. */
tree tem = newtype;
newtype = oldtype;
if (TYPE_USER_ALIGN (tem))
{
if (TYPE_ALIGN (tem) > TYPE_ALIGN (newtype))
SET_TYPE_ALIGN (newtype, TYPE_ALIGN (tem));
TYPE_USER_ALIGN (newtype) = true;
}
/* And remove the new type from the variants list. */
if (TYPE_NAME (TREE_TYPE (newdecl)) == newdecl)
{
tree remove = TREE_TYPE (newdecl);
if (TYPE_MAIN_VARIANT (remove) == remove)
{
gcc_assert (TYPE_NEXT_VARIANT (remove) == NULL_TREE);
/* If remove is the main variant, no need to remove that
from the list. One of the DECL_ORIGINAL_TYPE
variants, e.g. created for aligned attribute, might still
refer to the newdecl TYPE_DECL though, so remove that one
in that case. */
if (DECL_ORIGINAL_TYPE (newdecl)
&& DECL_ORIGINAL_TYPE (newdecl) != remove)
for (tree t = TYPE_MAIN_VARIANT (DECL_ORIGINAL_TYPE (newdecl));
t; t = TYPE_MAIN_VARIANT (t))
if (TYPE_NAME (TYPE_NEXT_VARIANT (t)) == newdecl)
{
TYPE_NEXT_VARIANT (t)
= TYPE_NEXT_VARIANT (TYPE_NEXT_VARIANT (t));
break;
}
}
else
for (tree t = TYPE_MAIN_VARIANT (remove); ;
t = TYPE_NEXT_VARIANT (t))
if (TYPE_NEXT_VARIANT (t) == remove)
{
TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (remove);
break;
}
}
}
/* Merge the data types specified in the two decls. */
TREE_TYPE (newdecl)
= TREE_TYPE (olddecl)
= composite_type (newtype, oldtype);
/* Lay the type out, unless already done. */
if (!comptypes (oldtype, TREE_TYPE (newdecl)))
{
if (TREE_TYPE (newdecl) != error_mark_node)
layout_type (TREE_TYPE (newdecl));
if (TREE_CODE (newdecl) != FUNCTION_DECL
&& TREE_CODE (newdecl) != TYPE_DECL
&& TREE_CODE (newdecl) != CONST_DECL)
layout_decl (newdecl, 0);
}
else
{
/* Since the type is OLDDECL's, make OLDDECL's size go with. */
DECL_SIZE (newdecl) = DECL_SIZE (olddecl);
DECL_SIZE_UNIT (newdecl) = DECL_SIZE_UNIT (olddecl);
SET_DECL_MODE (newdecl, DECL_MODE (olddecl));
if (DECL_ALIGN (olddecl) > DECL_ALIGN (newdecl))
{
SET_DECL_ALIGN (newdecl, DECL_ALIGN (olddecl));
DECL_USER_ALIGN (newdecl) |= DECL_USER_ALIGN (olddecl);
}
else if (DECL_ALIGN (olddecl) == DECL_ALIGN (newdecl)
&& DECL_USER_ALIGN (olddecl) != DECL_USER_ALIGN (newdecl))
DECL_USER_ALIGN (newdecl) = 1;
if (DECL_WARN_IF_NOT_ALIGN (olddecl)
> DECL_WARN_IF_NOT_ALIGN (newdecl))
SET_DECL_WARN_IF_NOT_ALIGN (newdecl,
DECL_WARN_IF_NOT_ALIGN (olddecl));
}
/* Keep the old rtl since we can safely use it. */
if (HAS_RTL_P (olddecl))
COPY_DECL_RTL (olddecl, newdecl);
/* Merge the type qualifiers. */
if (TREE_READONLY (newdecl))
TREE_READONLY (olddecl) = 1;
if (TREE_THIS_VOLATILE (newdecl))
TREE_THIS_VOLATILE (olddecl) = 1;
/* Merge deprecatedness. */
if (TREE_DEPRECATED (newdecl))
TREE_DEPRECATED (olddecl) = 1;
/* Merge unavailability. */
if (TREE_UNAVAILABLE (newdecl))
TREE_UNAVAILABLE (olddecl) = 1;
/* If a decl is in a system header and the other isn't, keep the one on the
system header. Otherwise, keep source location of definition rather than
declaration and of prototype rather than non-prototype unless that
prototype is built-in. */
if (CODE_CONTAINS_STRUCT (TREE_CODE (olddecl), TS_DECL_WITH_VIS)
&& DECL_IN_SYSTEM_HEADER (olddecl)
&& !DECL_IN_SYSTEM_HEADER (newdecl) )
DECL_SOURCE_LOCATION (newdecl) = DECL_SOURCE_LOCATION (olddecl);
else if (CODE_CONTAINS_STRUCT (TREE_CODE (olddecl), TS_DECL_WITH_VIS)
&& DECL_IN_SYSTEM_HEADER (newdecl)
&& !DECL_IN_SYSTEM_HEADER (olddecl))
DECL_SOURCE_LOCATION (olddecl) = DECL_SOURCE_LOCATION (newdecl);
else if ((DECL_INITIAL (newdecl) == NULL_TREE
&& DECL_INITIAL (olddecl) != NULL_TREE)
|| (old_is_prototype && !new_is_prototype
&& !C_DECL_BUILTIN_PROTOTYPE (olddecl)))
DECL_SOURCE_LOCATION (newdecl) = DECL_SOURCE_LOCATION (olddecl);
/* Merge the initialization information. */
if (DECL_INITIAL (newdecl) == NULL_TREE)
DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
/* Merge the threadprivate attribute. */
if (VAR_P (olddecl) && C_DECL_THREADPRIVATE_P (olddecl))
C_DECL_THREADPRIVATE_P (newdecl) = 1;
if (CODE_CONTAINS_STRUCT (TREE_CODE (olddecl), TS_DECL_WITH_VIS))
{
/* Copy the assembler name.
Currently, it can only be defined in the prototype. */
COPY_DECL_ASSEMBLER_NAME (olddecl, newdecl);
/* Use visibility of whichever declaration had it specified */
if (DECL_VISIBILITY_SPECIFIED (olddecl))
{
DECL_VISIBILITY (newdecl) = DECL_VISIBILITY (olddecl);
DECL_VISIBILITY_SPECIFIED (newdecl) = 1;
}
if (TREE_CODE (newdecl) == FUNCTION_DECL)
{
DECL_STATIC_CONSTRUCTOR(newdecl) |= DECL_STATIC_CONSTRUCTOR(olddecl);
DECL_STATIC_DESTRUCTOR (newdecl) |= DECL_STATIC_DESTRUCTOR (olddecl);
DECL_NO_LIMIT_STACK (newdecl) |= DECL_NO_LIMIT_STACK (olddecl);
DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (newdecl)
|= DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (olddecl);
TREE_THIS_VOLATILE (newdecl) |= TREE_THIS_VOLATILE (olddecl);
DECL_IS_MALLOC (newdecl) |= DECL_IS_MALLOC (olddecl);
if (DECL_IS_OPERATOR_NEW_P (olddecl))
DECL_SET_IS_OPERATOR_NEW (newdecl, true);
if (DECL_IS_OPERATOR_DELETE_P (olddecl))
DECL_SET_IS_OPERATOR_DELETE (newdecl, true);
TREE_READONLY (newdecl) |= TREE_READONLY (olddecl);
DECL_PURE_P (newdecl) |= DECL_PURE_P (olddecl);
DECL_IS_NOVOPS (newdecl) |= DECL_IS_NOVOPS (olddecl);
}
/* Merge the storage class information. */
merge_weak (newdecl, olddecl);
/* For functions, static overrides non-static. */
if (TREE_CODE (newdecl) == FUNCTION_DECL)
{
TREE_PUBLIC (newdecl) &= TREE_PUBLIC (olddecl);
/* This is since we don't automatically
copy the attributes of NEWDECL into OLDDECL. */
TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
/* If this clears `static', clear it in the identifier too. */
if (!TREE_PUBLIC (olddecl))
TREE_PUBLIC (DECL_NAME (olddecl)) = 0;
}
}
/* In c99, 'extern' declaration before (or after) 'inline' means this
function is not DECL_EXTERNAL, unless 'gnu_inline' attribute
is present. */
if (TREE_CODE (newdecl) == FUNCTION_DECL
&& !flag_gnu89_inline
&& (DECL_DECLARED_INLINE_P (newdecl)
|| DECL_DECLARED_INLINE_P (olddecl))
&& (!DECL_DECLARED_INLINE_P (newdecl)
|| !DECL_DECLARED_INLINE_P (olddecl)
|| !DECL_EXTERNAL (olddecl))
&& DECL_EXTERNAL (newdecl)
&& !lookup_attribute ("gnu_inline", DECL_ATTRIBUTES (newdecl))
&& !current_function_decl)
DECL_EXTERNAL (newdecl) = 0;
/* An inline definition following a static declaration is not
DECL_EXTERNAL. */
if (new_is_definition
&& (DECL_DECLARED_INLINE_P (newdecl)
|| DECL_DECLARED_INLINE_P (olddecl))
&& !TREE_PUBLIC (olddecl))
DECL_EXTERNAL (newdecl) = 0;
if (DECL_EXTERNAL (newdecl))
{
TREE_STATIC (newdecl) = TREE_STATIC (olddecl);
DECL_EXTERNAL (newdecl) = DECL_EXTERNAL (olddecl);
/* An extern decl does not override previous storage class. */
TREE_PUBLIC (newdecl) = TREE_PUBLIC (olddecl);
if (!DECL_EXTERNAL (newdecl))
{
DECL_CONTEXT (newdecl) = DECL_CONTEXT (olddecl);
DECL_COMMON (newdecl) = DECL_COMMON (olddecl);
}
}
else
{
TREE_STATIC (olddecl) = TREE_STATIC (newdecl);
TREE_PUBLIC (olddecl) = TREE_PUBLIC (newdecl);
}
if (TREE_CODE (newdecl) == FUNCTION_DECL)
{
/* If we're redefining a function previously defined as extern
inline, make sure we emit debug info for the inline before we
throw it away, in case it was inlined into a function that
hasn't been written out yet. */
if (new_is_definition && DECL_INITIAL (olddecl))
/* The new defn must not be inline. */
DECL_UNINLINABLE (newdecl) = 1;
else
{
/* If either decl says `inline', this fn is inline, unless
its definition was passed already. */
if (DECL_DECLARED_INLINE_P (newdecl)
|| DECL_DECLARED_INLINE_P (olddecl))
DECL_DECLARED_INLINE_P (newdecl) = 1;
DECL_UNINLINABLE (newdecl) = DECL_UNINLINABLE (olddecl)
= (DECL_UNINLINABLE (newdecl) || DECL_UNINLINABLE (olddecl));
DECL_DISREGARD_INLINE_LIMITS (newdecl)
= DECL_DISREGARD_INLINE_LIMITS (olddecl)
= (DECL_DISREGARD_INLINE_LIMITS (newdecl)
|| DECL_DISREGARD_INLINE_LIMITS (olddecl));
}
if (fndecl_built_in_p (olddecl))
{
/* If redeclaring a builtin function, it stays built in.
But it gets tagged as having been declared. */
copy_decl_built_in_function (newdecl, olddecl);
C_DECL_DECLARED_BUILTIN (newdecl) = 1;
if (new_is_prototype)
{
C_DECL_BUILTIN_PROTOTYPE (newdecl) = 0;
if (DECL_BUILT_IN_CLASS (newdecl) == BUILT_IN_NORMAL)
{
enum built_in_function fncode = DECL_FUNCTION_CODE (newdecl);
switch (fncode)
{
/* If a compatible prototype of these builtin functions
is seen, assume the runtime implements it with the
expected semantics. */
case BUILT_IN_STPCPY:
if (builtin_decl_explicit_p (fncode))
set_builtin_decl_implicit_p (fncode, true);
break;
default:
if (builtin_decl_explicit_p (fncode))
set_builtin_decl_declared_p (fncode, true);
break;
}
copy_attributes_to_builtin (newdecl);
}
}
else
C_DECL_BUILTIN_PROTOTYPE (newdecl)
= C_DECL_BUILTIN_PROTOTYPE (olddecl);
}
/* Preserve function specific target and optimization options */
if (DECL_FUNCTION_SPECIFIC_TARGET (olddecl)
&& !DECL_FUNCTION_SPECIFIC_TARGET (newdecl))
DECL_FUNCTION_SPECIFIC_TARGET (newdecl)
= DECL_FUNCTION_SPECIFIC_TARGET (olddecl);
if (DECL_FUNCTION_SPECIFIC_OPTIMIZATION (olddecl)
&& !DECL_FUNCTION_SPECIFIC_OPTIMIZATION (newdecl))
DECL_FUNCTION_SPECIFIC_OPTIMIZATION (newdecl)
= DECL_FUNCTION_SPECIFIC_OPTIMIZATION (olddecl);
/* Also preserve various other info from the definition. */
if (!new_is_definition)
{
tree t;
DECL_RESULT (newdecl) = DECL_RESULT (olddecl);
DECL_INITIAL (newdecl) = DECL_INITIAL (olddecl);
DECL_STRUCT_FUNCTION (newdecl) = DECL_STRUCT_FUNCTION (olddecl);
DECL_SAVED_TREE (newdecl) = DECL_SAVED_TREE (olddecl);
DECL_ARGUMENTS (newdecl) = copy_list (DECL_ARGUMENTS (olddecl));
for (t = DECL_ARGUMENTS (newdecl); t ; t = DECL_CHAIN (t))
DECL_CONTEXT (t) = newdecl;
/* See if we've got a function to instantiate from. */
if (DECL_SAVED_TREE (olddecl))
DECL_ABSTRACT_ORIGIN (newdecl)
= DECL_ABSTRACT_ORIGIN (olddecl);
}
}
/* Merge the USED information. */
if (TREE_USED (olddecl))
TREE_USED (newdecl) = 1;
else if (TREE_USED (newdecl))
TREE_USED (olddecl) = 1;
if (VAR_P (olddecl) || TREE_CODE (olddecl) == PARM_DECL)
DECL_READ_P (newdecl) |= DECL_READ_P (olddecl);
if (DECL_PRESERVE_P (olddecl))
DECL_PRESERVE_P (newdecl) = 1;
else if (DECL_PRESERVE_P (newdecl))
DECL_PRESERVE_P (olddecl) = 1;
/* Merge DECL_COMMON */
if (VAR_P (olddecl) && VAR_P (newdecl)
&& !lookup_attribute ("common", DECL_ATTRIBUTES (newdecl))
&& !lookup_attribute ("nocommon", DECL_ATTRIBUTES (newdecl)))
DECL_COMMON (newdecl) = DECL_COMMON (newdecl) && DECL_COMMON (olddecl);
/* Copy most of the decl-specific fields of NEWDECL into OLDDECL.
But preserve OLDDECL's DECL_UID, DECL_CONTEXT and
DECL_ARGUMENTS (if appropriate). */
{
unsigned olddecl_uid = DECL_UID (olddecl);
tree olddecl_context = DECL_CONTEXT (olddecl);
tree olddecl_arguments = NULL;
if (TREE_CODE (olddecl) == FUNCTION_DECL)
olddecl_arguments = DECL_ARGUMENTS (olddecl);
memcpy ((char *) olddecl + sizeof (struct tree_common),
(char *) newdecl + sizeof (struct tree_common),