https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88506
Bug ID: 88506
Summary: missing warning assigning to a pointer with
incompatible attributes
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: msebor at gcc dot gnu.org
Target Milestone: ---
Similar to bug 88505, GCC silently accepts assignments of addresses of
functions to pointers declared with incompatible attributes. See the test case
below.
GCC should check the attributes on pointer initialization and assignment for
compatibility and issue a warning if the destination is more restrictive than
the source.
$ cat u.c && gcc -O2 -S -Wall -Wextra -fdump-tree-optimized=/dev/stdout u.c
#include <stdlib.h>
__attribute__ ((alloc_align (2), alloc_size (1))) void*
(*paligned_alloc)(size_t, size_t) = aligned_alloc;
size_t f (void)
{
size_t align = 16;
void *p = paligned_alloc (48, align);
return __builtin_object_size (p, 0); // bad alloc_size used
}
void g (void)
{
size_t align = 32;
void *p = paligned_alloc (4, align);
if ((long)p & (align - 1)) // bad alloc_align used
__builtin_abort ();
}
;; Function f (f, funcdef_no=10, decl_uid=2495, cgraph_uid=11, symbol_order=11)
f ()
{
void * (*<T46a>) (size_t, size_t) paligned_alloc.0_1;
<bb 2> [local count: 1073741824]:
paligned_alloc.0_1 = paligned_alloc;
paligned_alloc.0_1 (48, 16);
return 48;
}
;; Function g (g, funcdef_no=11, decl_uid=2500, cgraph_uid=12, symbol_order=12)
g ()
{
void * (*<T46a>) (size_t, size_t) paligned_alloc.1_1;
<bb 2> [local count: 1073741824]:
paligned_alloc.1_1 = paligned_alloc;
paligned_alloc.1_1 (4, 32); [tail call]
return;
}
tmp$ cat u.c && /ssd/build/gcc-svn/gcc/xgcc -B /ssd/build/gcc-svn/gcc -O2 -S
-Wall -Wextra -fdump-tree-optimized=/dev/stdout u.c
