------- Comment #15 from rguenth at gcc dot gnu dot org 2010-05-05 13:56
-------
Testcase that does not violate strict aliasing rules (and thus should not
be miscompiled at -O2 or -Os either):
extern char B[256 * sizeof(void *)];
typedef void *FILE;
typedef struct globals {
int c;
FILE **l;
} __attribute__((may_alias)) T;
void* xrealloc(void *vector, unsigned sizeof_and_shift, int idx);
void add_input_file(FILE *file)
{
(*(T*)&B).l = xrealloc(((*(T*)&B).l),
(sizeof(((*(T*)&B).l)[0]) << 8) + (2),
((*(T*)&B).c));
(*(T*)&B).l[(*(T*)&B).c++] = file;
}
I have a patch. Workaround for 4.5.0: -fno-pta.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43987
