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c-typeck.c
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c-typeck.c
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/* Build expressions with type checking for C compiler.
Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
1998, 1999, 2000, 2001, 2002, 2003, 2004 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 2, 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 COPYING. If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA. */
/* This file is part of the C front end.
It contains routines to build C expressions given their operands,
including computing the types of the result, C-specific error checks,
and some optimization.
There are also routines to build RETURN_STMT nodes and CASE_STMT nodes,
and to process initializations in declarations (since they work
like a strange sort of assignment). */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "rtl.h"
#include "tree.h"
#include "c-tree.h"
#include "tm_p.h"
#include "flags.h"
#include "output.h"
#include "expr.h"
#include "toplev.h"
#include "intl.h"
#include "ggc.h"
#include "target.h"
/* Nonzero if we've already printed a "missing braces around initializer"
message within this initializer. */
static int missing_braces_mentioned;
static int require_constant_value;
static int require_constant_elements;
static tree qualify_type (tree, tree);
static int same_translation_unit_p (tree, tree);
static int tagged_types_tu_compatible_p (tree, tree, int);
static int comp_target_types (tree, tree, int);
static int function_types_compatible_p (tree, tree, int);
static int type_lists_compatible_p (tree, tree, int);
static tree decl_constant_value_for_broken_optimization (tree);
static tree default_function_array_conversion (tree);
static tree lookup_field (tree, tree);
static tree convert_arguments (tree, tree, tree, tree);
static tree pointer_diff (tree, tree);
static tree unary_complex_lvalue (enum tree_code, tree, int);
static void pedantic_lvalue_warning (enum tree_code);
static tree internal_build_compound_expr (tree, int);
static tree convert_for_assignment (tree, tree, const char *, tree, tree,
int);
static void warn_for_assignment (const char *, const char *, tree, int);
static tree valid_compound_expr_initializer (tree, tree);
static void push_string (const char *);
static void push_member_name (tree);
static void push_array_bounds (int);
static int spelling_length (void);
static char *print_spelling (char *);
static void warning_init (const char *);
static tree digest_init (tree, tree, int);
static void output_init_element (tree, tree, tree, int);
static void output_pending_init_elements (int);
static int set_designator (int);
static void push_range_stack (tree);
static void add_pending_init (tree, tree);
static void set_nonincremental_init (void);
static void set_nonincremental_init_from_string (tree);
static tree find_init_member (tree);
/* Do `exp = require_complete_type (exp);' to make sure exp
does not have an incomplete type. (That includes void types.) */
tree
require_complete_type (tree value)
{
tree type = TREE_TYPE (value);
if (value == error_mark_node || type == error_mark_node)
return error_mark_node;
/* First, detect a valid value with a complete type. */
if (COMPLETE_TYPE_P (type))
return value;
c_incomplete_type_error (value, type);
return error_mark_node;
}
/* Print an error message for invalid use of an incomplete type.
VALUE is the expression that was used (or 0 if that isn't known)
and TYPE is the type that was invalid. */
void
c_incomplete_type_error (tree value, tree type)
{
const char *type_code_string;
/* Avoid duplicate error message. */
if (TREE_CODE (type) == ERROR_MARK)
return;
if (value != 0 && (TREE_CODE (value) == VAR_DECL
|| TREE_CODE (value) == PARM_DECL))
error ("`%s' has an incomplete type",
IDENTIFIER_POINTER (DECL_NAME (value)));
else
{
retry:
/* We must print an error message. Be clever about what it says. */
switch (TREE_CODE (type))
{
case RECORD_TYPE:
type_code_string = "struct";
break;
case UNION_TYPE:
type_code_string = "union";
break;
case ENUMERAL_TYPE:
type_code_string = "enum";
break;
case VOID_TYPE:
error ("invalid use of void expression");
return;
case ARRAY_TYPE:
if (TYPE_DOMAIN (type))
{
if (TYPE_MAX_VALUE (TYPE_DOMAIN (type)) == NULL)
{
error ("invalid use of flexible array member");
return;
}
type = TREE_TYPE (type);
goto retry;
}
error ("invalid use of array with unspecified bounds");
return;
default:
abort ();
}
if (TREE_CODE (TYPE_NAME (type)) == IDENTIFIER_NODE)
error ("invalid use of undefined type `%s %s'",
type_code_string, IDENTIFIER_POINTER (TYPE_NAME (type)));
else
/* If this type has a typedef-name, the TYPE_NAME is a TYPE_DECL. */
error ("invalid use of incomplete typedef `%s'",
IDENTIFIER_POINTER (DECL_NAME (TYPE_NAME (type))));
}
}
/* Given a type, apply default promotions wrt unnamed function
arguments and return the new type. */
tree
c_type_promotes_to (tree type)
{
if (TYPE_MAIN_VARIANT (type) == float_type_node)
return double_type_node;
if (c_promoting_integer_type_p (type))
{
/* Preserve unsignedness if not really getting any wider. */
if (TREE_UNSIGNED (type)
&& (TYPE_PRECISION (type) == TYPE_PRECISION (integer_type_node)))
return unsigned_type_node;
return integer_type_node;
}
return type;
}
/* Return a variant of TYPE which has all the type qualifiers of LIKE
as well as those of TYPE. */
static tree
qualify_type (tree type, tree like)
{
return c_build_qualified_type (type,
TYPE_QUALS (type) | TYPE_QUALS (like));
}
/* Return the common type of two types.
We assume that comptypes has already been done and returned 1;
if that isn't so, this may crash. In particular, we assume that qualifiers
match.
This is the type for the result of most arithmetic operations
if the operands have the given two types. */
tree
common_type (tree t1, tree t2)
{
enum tree_code code1;
enum tree_code code2;
tree attributes;
/* Save time if the two types are the same. */
if (t1 == t2) return t1;
/* If one type is nonsense, use the other. */
if (t1 == error_mark_node)
return t2;
if (t2 == error_mark_node)
return t1;
/* Merge the attributes. */
attributes = (*targetm.merge_type_attributes) (t1, t2);
/* Treat an enum type as the unsigned integer type of the same width. */
if (TREE_CODE (t1) == ENUMERAL_TYPE)
t1 = c_common_type_for_size (TYPE_PRECISION (t1), 1);
if (TREE_CODE (t2) == ENUMERAL_TYPE)
t2 = c_common_type_for_size (TYPE_PRECISION (t2), 1);
code1 = TREE_CODE (t1);
code2 = TREE_CODE (t2);
/* If one type is complex, form the common type of the non-complex
components, then make that complex. Use T1 or T2 if it is the
required type. */
if (code1 == COMPLEX_TYPE || code2 == COMPLEX_TYPE)
{
tree subtype1 = code1 == COMPLEX_TYPE ? TREE_TYPE (t1) : t1;
tree subtype2 = code2 == COMPLEX_TYPE ? TREE_TYPE (t2) : t2;
tree subtype = common_type (subtype1, subtype2);
if (code1 == COMPLEX_TYPE && TREE_TYPE (t1) == subtype)
return build_type_attribute_variant (t1, attributes);
else if (code2 == COMPLEX_TYPE && TREE_TYPE (t2) == subtype)
return build_type_attribute_variant (t2, attributes);
else
return build_type_attribute_variant (build_complex_type (subtype),
attributes);
}
switch (code1)
{
case INTEGER_TYPE:
case REAL_TYPE:
/* If only one is real, use it as the result. */
if (code1 == REAL_TYPE && code2 != REAL_TYPE)
return build_type_attribute_variant (t1, attributes);
if (code2 == REAL_TYPE && code1 != REAL_TYPE)
return build_type_attribute_variant (t2, attributes);
/* Both real or both integers; use the one with greater precision. */
if (TYPE_PRECISION (t1) > TYPE_PRECISION (t2))
return build_type_attribute_variant (t1, attributes);
else if (TYPE_PRECISION (t2) > TYPE_PRECISION (t1))
return build_type_attribute_variant (t2, attributes);
/* Same precision. Prefer longs to ints even when same size. */
if (TYPE_MAIN_VARIANT (t1) == long_unsigned_type_node
|| TYPE_MAIN_VARIANT (t2) == long_unsigned_type_node)
{
t1 = build_qualified_type (long_unsigned_type_node,
TYPE_QUALS (t1));
return build_type_attribute_variant (t1, attributes);
}
if (TYPE_MAIN_VARIANT (t1) == long_integer_type_node
|| TYPE_MAIN_VARIANT (t2) == long_integer_type_node)
{
tree ntype;
/* But preserve unsignedness from the other type,
since long cannot hold all the values of an unsigned int. */
if (TREE_UNSIGNED (t1) || TREE_UNSIGNED (t2))
ntype = long_unsigned_type_node;
else
ntype = long_integer_type_node;
ntype = build_qualified_type (ntype, TYPE_QUALS (t1));
return build_type_attribute_variant (ntype, attributes);
}
/* Likewise, prefer long double to double even if same size. */
if (TYPE_MAIN_VARIANT (t1) == long_double_type_node
|| TYPE_MAIN_VARIANT (t2) == long_double_type_node)
{
t1 = build_qualified_type (long_double_type_node,
TYPE_QUALS (t1));
return build_type_attribute_variant (t1, attributes);
}
/* Otherwise prefer the unsigned one. */
if (TREE_UNSIGNED (t1))
return build_type_attribute_variant (t1, attributes);
else
return build_type_attribute_variant (t2, attributes);
case POINTER_TYPE:
/* For two pointers, do this recursively on the target type,
and combine the qualifiers of the two types' targets. */
/* This code was turned off; I don't know why.
But ANSI C specifies doing this with the qualifiers.
So I turned it on again. */
{
tree pointed_to_1 = TREE_TYPE (t1);
tree pointed_to_2 = TREE_TYPE (t2);
tree target = common_type (TYPE_MAIN_VARIANT (pointed_to_1),
TYPE_MAIN_VARIANT (pointed_to_2));
t1 = build_pointer_type (c_build_qualified_type
(target,
TYPE_QUALS (pointed_to_1) |
TYPE_QUALS (pointed_to_2)));
return build_type_attribute_variant (t1, attributes);
}
case ARRAY_TYPE:
{
tree elt = common_type (TREE_TYPE (t1), TREE_TYPE (t2));
/* Save space: see if the result is identical to one of the args. */
if (elt == TREE_TYPE (t1) && TYPE_DOMAIN (t1))
return build_type_attribute_variant (t1, attributes);
if (elt == TREE_TYPE (t2) && TYPE_DOMAIN (t2))
return build_type_attribute_variant (t2, attributes);
/* Merge the element types, and have a size if either arg has one. */
t1 = build_array_type (elt, TYPE_DOMAIN (TYPE_DOMAIN (t1) ? t1 : t2));
return build_type_attribute_variant (t1, attributes);
}
case FUNCTION_TYPE:
/* Function types: prefer the one that specified arg types.
If both do, merge the arg types. Also merge the return types. */
{
tree valtype = common_type (TREE_TYPE (t1), TREE_TYPE (t2));
tree p1 = TYPE_ARG_TYPES (t1);
tree p2 = TYPE_ARG_TYPES (t2);
int len;
tree newargs, n;
int i;
/* Save space: see if the result is identical to one of the args. */
if (valtype == TREE_TYPE (t1) && ! TYPE_ARG_TYPES (t2))
return build_type_attribute_variant (t1, attributes);
if (valtype == TREE_TYPE (t2) && ! TYPE_ARG_TYPES (t1))
return build_type_attribute_variant (t2, attributes);
/* Simple way if one arg fails to specify argument types. */
if (TYPE_ARG_TYPES (t1) == 0)
{
t1 = build_function_type (valtype, TYPE_ARG_TYPES (t2));
return build_type_attribute_variant (t1, attributes);
}
if (TYPE_ARG_TYPES (t2) == 0)
{
t1 = build_function_type (valtype, TYPE_ARG_TYPES (t1));
return build_type_attribute_variant (t1, attributes);
}
/* If both args specify argument types, we must merge the two
lists, argument by argument. */
pushlevel (0);
declare_parm_level ();
len = list_length (p1);
newargs = 0;
for (i = 0; i < len; i++)
newargs = tree_cons (NULL_TREE, NULL_TREE, newargs);
n = newargs;
for (; p1;
p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2), n = TREE_CHAIN (n))
{
/* A null type means arg type is not specified.
Take whatever the other function type has. */
if (TREE_VALUE (p1) == 0)
{
TREE_VALUE (n) = TREE_VALUE (p2);
goto parm_done;
}
if (TREE_VALUE (p2) == 0)
{
TREE_VALUE (n) = TREE_VALUE (p1);
goto parm_done;
}
/* Given wait (union {union wait *u; int *i} *)
and wait (union wait *),
prefer union wait * as type of parm. */
if (TREE_CODE (TREE_VALUE (p1)) == UNION_TYPE
&& TREE_VALUE (p1) != TREE_VALUE (p2))
{
tree memb;
for (memb = TYPE_FIELDS (TREE_VALUE (p1));
memb; memb = TREE_CHAIN (memb))
if (comptypes (TREE_TYPE (memb), TREE_VALUE (p2),
COMPARE_STRICT))
{
TREE_VALUE (n) = TREE_VALUE (p2);
if (pedantic)
pedwarn ("function types not truly compatible in ISO C");
goto parm_done;
}
}
if (TREE_CODE (TREE_VALUE (p2)) == UNION_TYPE
&& TREE_VALUE (p2) != TREE_VALUE (p1))
{
tree memb;
for (memb = TYPE_FIELDS (TREE_VALUE (p2));
memb; memb = TREE_CHAIN (memb))
if (comptypes (TREE_TYPE (memb), TREE_VALUE (p1),
COMPARE_STRICT))
{
TREE_VALUE (n) = TREE_VALUE (p1);
if (pedantic)
pedwarn ("function types not truly compatible in ISO C");
goto parm_done;
}
}
TREE_VALUE (n) = common_type (TREE_VALUE (p1), TREE_VALUE (p2));
parm_done: ;
}
poplevel (0, 0, 0);
t1 = build_function_type (valtype, newargs);
/* ... falls through ... */
}
default:
return build_type_attribute_variant (t1, attributes);
}
}
/* Return 1 if TYPE1 and TYPE2 are compatible types for assignment
or various other operations. Return 2 if they are compatible
but a warning may be needed if you use them together. */
int
comptypes (tree type1, tree type2, int flags)
{
tree t1 = type1;
tree t2 = type2;
int attrval, val;
/* Suppress errors caused by previously reported errors. */
if (t1 == t2 || !t1 || !t2
|| TREE_CODE (t1) == ERROR_MARK || TREE_CODE (t2) == ERROR_MARK)
return 1;
/* If either type is the internal version of sizetype, return the
language version. */
if (TREE_CODE (t1) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t1)
&& TYPE_DOMAIN (t1) != 0)
t1 = TYPE_DOMAIN (t1);
if (TREE_CODE (t2) == INTEGER_TYPE && TYPE_IS_SIZETYPE (t2)
&& TYPE_DOMAIN (t2) != 0)
t2 = TYPE_DOMAIN (t2);
/* Enumerated types are compatible with integer types, but this is
not transitive: two enumerated types in the same translation unit
are compatible with each other only if they are the same type. */
if (TREE_CODE (t1) == ENUMERAL_TYPE && TREE_CODE (t2) != ENUMERAL_TYPE)
t1 = c_common_type_for_size (TYPE_PRECISION (t1), TREE_UNSIGNED (t1));
else if (TREE_CODE (t2) == ENUMERAL_TYPE && TREE_CODE (t1) != ENUMERAL_TYPE)
t2 = c_common_type_for_size (TYPE_PRECISION (t2), TREE_UNSIGNED (t2));
if (t1 == t2)
return 1;
/* Different classes of types can't be compatible. */
if (TREE_CODE (t1) != TREE_CODE (t2))
return 0;
/* Qualifiers must match. */
if (TYPE_QUALS (t1) != TYPE_QUALS (t2))
return 0;
/* Allow for two different type nodes which have essentially the same
definition. Note that we already checked for equality of the type
qualifiers (just above). */
if (TYPE_MAIN_VARIANT (t1) == TYPE_MAIN_VARIANT (t2))
return 1;
/* 1 if no need for warning yet, 2 if warning cause has been seen. */
if (! (attrval = (*targetm.comp_type_attributes) (t1, t2)))
return 0;
/* 1 if no need for warning yet, 2 if warning cause has been seen. */
val = 0;
switch (TREE_CODE (t1))
{
case POINTER_TYPE:
/* We must give ObjC the first crack at comparing pointers, since
protocol qualifiers may be involved. */
if (c_dialect_objc () && (val = objc_comptypes (t1, t2, 0)) >= 0)
break;
val = (TREE_TYPE (t1) == TREE_TYPE (t2)
? 1 : comptypes (TREE_TYPE (t1), TREE_TYPE (t2), flags));
break;
case FUNCTION_TYPE:
val = function_types_compatible_p (t1, t2, flags);
break;
case ARRAY_TYPE:
{
tree d1 = TYPE_DOMAIN (t1);
tree d2 = TYPE_DOMAIN (t2);
bool d1_variable, d2_variable;
bool d1_zero, d2_zero;
val = 1;
/* Target types must match incl. qualifiers. */
if (TREE_TYPE (t1) != TREE_TYPE (t2)
&& 0 == (val = comptypes (TREE_TYPE (t1), TREE_TYPE (t2),
flags)))
return 0;
/* Sizes must match unless one is missing or variable. */
if (d1 == 0 || d2 == 0 || d1 == d2)
break;
d1_zero = ! TYPE_MAX_VALUE (d1);
d2_zero = ! TYPE_MAX_VALUE (d2);
d1_variable = (! d1_zero
&& (TREE_CODE (TYPE_MIN_VALUE (d1)) != INTEGER_CST
|| TREE_CODE (TYPE_MAX_VALUE (d1)) != INTEGER_CST));
d2_variable = (! d2_zero
&& (TREE_CODE (TYPE_MIN_VALUE (d2)) != INTEGER_CST
|| TREE_CODE (TYPE_MAX_VALUE (d2)) != INTEGER_CST));
if (d1_variable || d2_variable)
break;
if (d1_zero && d2_zero)
break;
if (d1_zero || d2_zero
|| ! tree_int_cst_equal (TYPE_MIN_VALUE (d1), TYPE_MIN_VALUE (d2))
|| ! tree_int_cst_equal (TYPE_MAX_VALUE (d1), TYPE_MAX_VALUE (d2)))
val = 0;
break;
}
case RECORD_TYPE:
/* We are dealing with two distinct structs. In assorted Objective-C
corner cases, however, these can still be deemed equivalent. */
if (c_dialect_objc () && objc_comptypes (t1, t2, 0) == 1)
val = 1;
case ENUMERAL_TYPE:
case UNION_TYPE:
if (val != 1 && !same_translation_unit_p (t1, t2))
val = tagged_types_tu_compatible_p (t1, t2, flags);
break;
case VECTOR_TYPE:
/* The target might allow certain vector types to be compatible. */
val = (*targetm.vector_opaque_p) (t1)
|| (*targetm.vector_opaque_p) (t2);
break;
default:
break;
}
return attrval == 2 && val == 1 ? 2 : val;
}
/* Return 1 if TTL and TTR are pointers to types that are equivalent,
ignoring their qualifiers. REFLEXIVE is only used by ObjC - set it
to 1 or 0 depending if the check of the pointer types is meant to
be reflexive or not (typically, assignments are not reflexive,
while comparisons are reflexive).
*/
static int
comp_target_types (tree ttl, tree ttr, int reflexive)
{
int val;
/* Give objc_comptypes a crack at letting these types through. */
if ((val = objc_comptypes (ttl, ttr, reflexive)) >= 0)
return val;
val = comptypes (TYPE_MAIN_VARIANT (TREE_TYPE (ttl)),
TYPE_MAIN_VARIANT (TREE_TYPE (ttr)), COMPARE_STRICT);
if (val == 2 && pedantic)
pedwarn ("types are not quite compatible");
return val;
}
/* Subroutines of `comptypes'. */
/* Determine whether two types derive from the same translation unit.
If the CONTEXT chain ends in a null, that type's context is still
being parsed, so if two types have context chains ending in null,
they're in the same translation unit. */
static int
same_translation_unit_p (tree t1, tree t2)
{
while (t1 && TREE_CODE (t1) != TRANSLATION_UNIT_DECL)
switch (TREE_CODE_CLASS (TREE_CODE (t1)))
{
case 'd': t1 = DECL_CONTEXT (t1); break;
case 't': t1 = TYPE_CONTEXT (t1); break;
case 'b': t1 = BLOCK_SUPERCONTEXT (t1); break;
default: abort ();
}
while (t2 && TREE_CODE (t2) != TRANSLATION_UNIT_DECL)
switch (TREE_CODE_CLASS (TREE_CODE (t2)))
{
case 'd': t2 = DECL_CONTEXT (t2); break;
case 't': t2 = TYPE_CONTEXT (t2); break;
case 'b': t2 = BLOCK_SUPERCONTEXT (t2); break;
default: abort ();
}
return t1 == t2;
}
/* The C standard says that two structures in different translation
units are compatible with each other only if the types of their
fields are compatible (among other things). So, consider two copies
of this structure: */
struct tagged_tu_seen {
const struct tagged_tu_seen * next;
tree t1;
tree t2;
};
/* Can they be compatible with each other? We choose to break the
recursion by allowing those types to be compatible. */
static const struct tagged_tu_seen * tagged_tu_seen_base;
/* Return 1 if two 'struct', 'union', or 'enum' types T1 and T2 are
compatible. If the two types are not the same (which has been
checked earlier), this can only happen when multiple translation
units are being compiled. See C99 6.2.7 paragraph 1 for the exact
rules. */
static int
tagged_types_tu_compatible_p (tree t1, tree t2, int flags)
{
tree s1, s2;
bool needs_warning = false;
/* We have to verify that the tags of the types are the same. This
is harder than it looks because this may be a typedef, so we have
to go look at the original type. It may even be a typedef of a
typedef... */
while (TYPE_NAME (t1)
&& TREE_CODE (TYPE_NAME (t1)) == TYPE_DECL
&& DECL_ORIGINAL_TYPE (TYPE_NAME (t1)))
t1 = DECL_ORIGINAL_TYPE (TYPE_NAME (t1));
while (TYPE_NAME (t2)
&& TREE_CODE (TYPE_NAME (t2)) == TYPE_DECL
&& DECL_ORIGINAL_TYPE (TYPE_NAME (t2)))
t2 = DECL_ORIGINAL_TYPE (TYPE_NAME (t2));
/* C90 didn't have the requirement that the two tags be the same. */
if (flag_isoc99 && TYPE_NAME (t1) != TYPE_NAME (t2))
return 0;
/* C90 didn't say what happened if one or both of the types were
incomplete; we choose to follow C99 rules here, which is that they
are compatible. */
if (TYPE_SIZE (t1) == NULL
|| TYPE_SIZE (t2) == NULL)
return 1;
{
const struct tagged_tu_seen * tts_i;
for (tts_i = tagged_tu_seen_base; tts_i != NULL; tts_i = tts_i->next)
if (tts_i->t1 == t1 && tts_i->t2 == t2)
return 1;
}
switch (TREE_CODE (t1))
{
case ENUMERAL_TYPE:
{
if (list_length (TYPE_VALUES (t1)) != list_length (TYPE_VALUES (t2)))
return 0;
for (s1 = TYPE_VALUES (t1); s1; s1 = TREE_CHAIN (s1))
{
s2 = purpose_member (TREE_PURPOSE (s1), TYPE_VALUES (t2));
if (s2 == NULL
|| simple_cst_equal (TREE_VALUE (s1), TREE_VALUE (s2)) != 1)
return 0;
}
return 1;
}
case UNION_TYPE:
{
if (list_length (TYPE_FIELDS (t1)) != list_length (TYPE_FIELDS (t2)))
return 0;
for (s1 = TYPE_FIELDS (t1); s1; s1 = TREE_CHAIN (s1))
{
bool ok = false;
struct tagged_tu_seen tts;
tts.next = tagged_tu_seen_base;
tts.t1 = t1;
tts.t2 = t2;
tagged_tu_seen_base = &tts;
if (DECL_NAME (s1) != NULL)
for (s2 = TYPE_VALUES (t2); s2; s2 = TREE_CHAIN (s2))
if (DECL_NAME (s1) == DECL_NAME (s2))
{
int result;
result = comptypes (TREE_TYPE (s1), TREE_TYPE (s2), flags);
if (result == 0)
break;
if (result == 2)
needs_warning = true;
if (TREE_CODE (s1) == FIELD_DECL
&& simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
DECL_FIELD_BIT_OFFSET (s2)) != 1)
break;
ok = true;
break;
}
tagged_tu_seen_base = tts.next;
if (! ok)
return 0;
}
return needs_warning ? 2 : 1;
}
case RECORD_TYPE:
{
struct tagged_tu_seen tts;
tts.next = tagged_tu_seen_base;
tts.t1 = t1;
tts.t2 = t2;
tagged_tu_seen_base = &tts;
for (s1 = TYPE_FIELDS (t1), s2 = TYPE_FIELDS (t2);
s1 && s2;
s1 = TREE_CHAIN (s1), s2 = TREE_CHAIN (s2))
{
int result;
if (TREE_CODE (s1) != TREE_CODE (s2)
|| DECL_NAME (s1) != DECL_NAME (s2))
break;
result = comptypes (TREE_TYPE (s1), TREE_TYPE (s2), flags);
if (result == 0)
break;
if (result == 2)
needs_warning = true;
if (TREE_CODE (s1) == FIELD_DECL
&& simple_cst_equal (DECL_FIELD_BIT_OFFSET (s1),
DECL_FIELD_BIT_OFFSET (s2)) != 1)
break;
}
tagged_tu_seen_base = tts.next;
if (s1 && s2)
return 0;
return needs_warning ? 2 : 1;
}
default:
abort ();
}
}
/* Return 1 if two function types F1 and F2 are compatible.
If either type specifies no argument types,
the other must specify a fixed number of self-promoting arg types.
Otherwise, if one type specifies only the number of arguments,
the other must specify that number of self-promoting arg types.
Otherwise, the argument types must match. */
static int
function_types_compatible_p (tree f1, tree f2, int flags)
{
tree args1, args2;
/* 1 if no need for warning yet, 2 if warning cause has been seen. */
int val = 1;
int val1;
tree ret1, ret2;
ret1 = TREE_TYPE (f1);
ret2 = TREE_TYPE (f2);
/* 'volatile' qualifiers on a function's return type mean the function
is noreturn. */
if (pedantic && TYPE_VOLATILE (ret1) != TYPE_VOLATILE (ret2))
pedwarn ("function return types not compatible due to `volatile'");
if (TYPE_VOLATILE (ret1))
ret1 = build_qualified_type (TYPE_MAIN_VARIANT (ret1),
TYPE_QUALS (ret1) & ~TYPE_QUAL_VOLATILE);
if (TYPE_VOLATILE (ret2))
ret2 = build_qualified_type (TYPE_MAIN_VARIANT (ret2),
TYPE_QUALS (ret2) & ~TYPE_QUAL_VOLATILE);
val = comptypes (ret1, ret2, flags);
if (val == 0)
return 0;
args1 = TYPE_ARG_TYPES (f1);
args2 = TYPE_ARG_TYPES (f2);
/* An unspecified parmlist matches any specified parmlist
whose argument types don't need default promotions. */
if (args1 == 0)
{
if (!self_promoting_args_p (args2))
return 0;
/* If one of these types comes from a non-prototype fn definition,
compare that with the other type's arglist.
If they don't match, ask for a warning (but no error). */
if (TYPE_ACTUAL_ARG_TYPES (f1)
&& 1 != type_lists_compatible_p (args2, TYPE_ACTUAL_ARG_TYPES (f1),
flags))
val = 2;
return val;
}
if (args2 == 0)
{
if (!self_promoting_args_p (args1))
return 0;
if (TYPE_ACTUAL_ARG_TYPES (f2)
&& 1 != type_lists_compatible_p (args1, TYPE_ACTUAL_ARG_TYPES (f2),
flags))
val = 2;
return val;
}
/* Both types have argument lists: compare them and propagate results. */
val1 = type_lists_compatible_p (args1, args2, flags);
return val1 != 1 ? val1 : val;
}
/* Check two lists of types for compatibility,
returning 0 for incompatible, 1 for compatible,
or 2 for compatible with warning. */
static int
type_lists_compatible_p (tree args1, tree args2, int flags)
{
/* 1 if no need for warning yet, 2 if warning cause has been seen. */
int val = 1;
int newval = 0;
while (1)
{
if (args1 == 0 && args2 == 0)
return val;
/* If one list is shorter than the other,
they fail to match. */
if (args1 == 0 || args2 == 0)
return 0;
/* A null pointer instead of a type
means there is supposed to be an argument
but nothing is specified about what type it has.
So match anything that self-promotes. */
if (TREE_VALUE (args1) == 0)
{
if (c_type_promotes_to (TREE_VALUE (args2)) != TREE_VALUE (args2))
return 0;
}
else if (TREE_VALUE (args2) == 0)
{
if (c_type_promotes_to (TREE_VALUE (args1)) != TREE_VALUE (args1))
return 0;
}
/* If one of the lists has an error marker, ignore this arg. */
else if (TREE_CODE (TREE_VALUE (args1)) == ERROR_MARK
|| TREE_CODE (TREE_VALUE (args2)) == ERROR_MARK)
;
else if (! (newval = comptypes (TYPE_MAIN_VARIANT (TREE_VALUE (args1)),
TYPE_MAIN_VARIANT (TREE_VALUE (args2)),
flags)))
{
/* Allow wait (union {union wait *u; int *i} *)
and wait (union wait *) to be compatible. */
if (TREE_CODE (TREE_VALUE (args1)) == UNION_TYPE
&& (TYPE_NAME (TREE_VALUE (args1)) == 0
|| TYPE_TRANSPARENT_UNION (TREE_VALUE (args1)))
&& TREE_CODE (TYPE_SIZE (TREE_VALUE (args1))) == INTEGER_CST
&& tree_int_cst_equal (TYPE_SIZE (TREE_VALUE (args1)),
TYPE_SIZE (TREE_VALUE (args2))))
{
tree memb;
for (memb = TYPE_FIELDS (TREE_VALUE (args1));
memb; memb = TREE_CHAIN (memb))
if (comptypes (TREE_TYPE (memb), TREE_VALUE (args2),
flags))
break;
if (memb == 0)
return 0;
}
else if (TREE_CODE (TREE_VALUE (args2)) == UNION_TYPE
&& (TYPE_NAME (TREE_VALUE (args2)) == 0
|| TYPE_TRANSPARENT_UNION (TREE_VALUE (args2)))
&& TREE_CODE (TYPE_SIZE (TREE_VALUE (args2))) == INTEGER_CST
&& tree_int_cst_equal (TYPE_SIZE (TREE_VALUE (args2)),
TYPE_SIZE (TREE_VALUE (args1))))
{
tree memb;
for (memb = TYPE_FIELDS (TREE_VALUE (args2));
memb; memb = TREE_CHAIN (memb))
if (comptypes (TREE_TYPE (memb), TREE_VALUE (args1),
flags))
break;
if (memb == 0)
return 0;
}
else
return 0;
}
/* comptypes said ok, but record if it said to warn. */
if (newval > val)
val = newval;
args1 = TREE_CHAIN (args1);
args2 = TREE_CHAIN (args2);
}
}
/* Compute the size to increment a pointer by. */
tree
c_size_in_bytes (tree type)
{
enum tree_code code = TREE_CODE (type);
if (code == FUNCTION_TYPE || code == VOID_TYPE || code == ERROR_MARK)
return size_one_node;
if (!COMPLETE_OR_VOID_TYPE_P (type))
{
error ("arithmetic on pointer to an incomplete type");
return size_one_node;
}
/* Convert in case a char is more than one unit. */
return size_binop (CEIL_DIV_EXPR, TYPE_SIZE_UNIT (type),
size_int (TYPE_PRECISION (char_type_node)
/ BITS_PER_UNIT));
}
/* Return either DECL or its known constant value (if it has one). */
tree
decl_constant_value (tree decl)
{
if (/* Don't change a variable array bound or initial value to a constant
in a place where a variable is invalid. */