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tree-optimization/116481 - avoid building function_type[]

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The following avoids building an array type with function or method
element type during diagnosing an array bound violation as this
will result in an error, rejecting a program with a not too useful
error message.  Instead build such array type manually.

	PR tree-optimization/116481
	* pointer-query.cc (build_printable_array_type):
	Build an array types with function or method element type
	manually to avoid bogus diagnostic.

	* gcc.dg/pr116481.c: New testcase.
This commit is contained in:
Richard Biener 2024-10-13 11:42:27 +02:00 • committed by Richard Biener
parent 3269a722b7
commit 1506027347
2 changed files with 24 additions and 0 deletions
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11
gcc/pointer-query.cc
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@ -2587,6 +2587,17 @@ array_elt_at_offset (tree artype, HOST_WIDE_INT off,
tree
build_printable_array_type (tree eltype, unsigned HOST_WIDE_INT nelts)
{
/* Cannot build an array type of functions or methods without
an error diagnostic. */
if (FUNC_OR_METHOD_TYPE_P (eltype))
{
tree arrtype = make_node (ARRAY_TYPE);
TREE_TYPE (arrtype) = eltype;
TYPE_SIZE (arrtype) = bitsize_zero_node;
TYPE_SIZE_UNIT (arrtype) = size_zero_node;
return arrtype;
}
if (TYPE_SIZE_UNIT (eltype)
&& TREE_CODE (TYPE_SIZE_UNIT (eltype)) == INTEGER_CST
&& !integer_zerop (TYPE_SIZE_UNIT (eltype))

13
gcc/testsuite/gcc.dg/pr116481.c Normal file
View file

@ -0,0 +1,13 @@
/* { dg-do compile } */
/* { dg-options "-O2 -Warray-bounds" } */
extern void tramp ();
int is_trampoline (void* function) /* { dg-bogus "arrays of functions are not meaningful" } */
{
void* tramp_address = tramp;
if (!(((unsigned long)function & 3) == 2))
return 0;
return (((long *) ((char*)function - 2))[0]
== ((long *) ((char*)tramp_address-2))[0]); /* { dg-warning "outside array bounds" } */
}