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c: fix ICE when forming composite type for two structures / unions [PR117548]

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When forming the composite type from two tagged type, we need to find the
original type for a typedecl to get the correct tag.

	PR c/117548

gcc/c/ChangeLog:
	* c-decl.cc (finish_struct): Add checking assertion.
	* c-typeck.cc (c_type_original): New function.
	(composite_types_internal): Get tag from original type.

gcc/testsuite/ChangeLog:
	* gcc.dg/pr117548.c: New test.
This commit is contained in:
Martin Uecker 2024-11-14 20:54:33 +01:00
parent 6aabe3adef
commit d8af6c203f
3 changed files with 38 additions and 15 deletions
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3
gcc/c/c-decl.cc
View file

@ -9872,6 +9872,9 @@ finish_struct (location_t loc, tree t, tree fieldlist, tree attributes,
hashval_t hash = c_struct_hasher::hash (t);
gcc_checking_assert (TYPE_STRUCTURAL_EQUALITY_P (t));
gcc_checking_assert (!TYPE_NAME (t)
|| TREE_CODE (TYPE_NAME (t)) == IDENTIFIER_NODE);
tree *e = c_struct_htab->find_slot_with_hash (t, hash, INSERT);
if (*e)
TYPE_CANONICAL (t) = *e;

38
gcc/c/c-typeck.cc
View file

@ -576,6 +576,21 @@ c_build_functype_attribute_variant (tree ntype, tree otype, tree attrs)
}
/* Given a type which could be a typedef name, make sure to return the
original type. */
static const_tree
c_type_original (const_tree t)
{
/* It may even be a typedef of a typedef...
In the case of compiler-created builtin structs the TYPE_DECL
may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
while (TYPE_NAME (t)
&& TREE_CODE (TYPE_NAME (t)) == TYPE_DECL
&& DECL_ORIGINAL_TYPE (TYPE_NAME (t)))
t = DECL_ORIGINAL_TYPE (TYPE_NAME (t));
return t;
}
/* Return the composite type of two compatible types.
@ -728,8 +743,11 @@ composite_type_internal (tree t1, tree t2, struct composite_cache* cache)
case UNION_TYPE:
if (flag_isoc23 && !comptypes_same_p (t1, t2))
{
/* Go to the original type to get the right tag. */
tree tag = TYPE_NAME (c_type_original (const_cast<tree> (t1)));
gcc_checking_assert (COMPLETE_TYPE_P (t1) && COMPLETE_TYPE_P (t2));
gcc_checking_assert (!TYPE_NAME (t1) || comptypes (t1, t2));
gcc_checking_assert (!tag || comptypes (t1, t2));
/* If a composite type for these two types is already under
construction, return it. */
@ -742,7 +760,7 @@ composite_type_internal (tree t1, tree t2, struct composite_cache* cache)
tree n = make_node (code1);
SET_TYPE_STRUCTURAL_EQUALITY (n);
TYPE_NAME (n) = TYPE_NAME (t1);
TYPE_NAME (n) = tag;
struct composite_cache cache2 = { t1, t2, n, cache };
cache = &cache2;
@ -1781,19 +1799,9 @@ tagged_types_tu_compatible_p (const_tree t1, const_tree t2,
/* 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...
In the case of compiler-created builtin structs the TYPE_DECL
may be a dummy, with no DECL_ORIGINAL_TYPE. Don't fault. */
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));
to go look at the original type. */
t1 = c_type_original (t1);
t2 = c_type_original (t2);
if (TYPE_NAME (t1) != TYPE_NAME (t2))
return false;

12
gcc/testsuite/gcc.dg/pr117548.c Normal file
View file

@ -0,0 +1,12 @@
/* { dg-do compile } */
/* { dg-options "-std=c23" } */
typedef struct A { int q; } A;
void f(A*);
int main(void)
{
struct A { int q; };
void f(struct A*);
}