https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92829
--- Comment #2 from Martin Sebor <msebor at gcc dot gnu.org> ---
The failures in Warray-bounds-56.c boil down to this test case where the
powerpc64 cross-compiler diagnoses only three out of the four buffer overflows,
missing the one first one in f(). The native x86_64 compiler detects all of
them. I'll adjust the test to avoid the failure but I'll probably raise a
separate bug to look into why it happens because it affects other tests as
well.
$ cat t.c && /build/powerpc64le-linux/gcc-svn/gcc/xgcc -B
/build/powerpc64le-linux/gcc-svn/gcc -O2 -S -Wall -Wno-stringop-overflow
-ftrack-macro-expansion=0 t.c
typedef __SIZE_TYPE__ size_t;
extern void* malloc (size_t);
extern char* strcpy (char*, const char*);
void sink (void*);
size_t value (void);
size_t range (size_t min, size_t max)
{
size_t val = value ();
return val < min || max < val ? min : val;
}
#undef T
#define T(T, src, n) do { \
char *s = src; \
typedef struct { T n, ax[]; } Flex; \
Flex *p = (Flex*)malloc (sizeof *p + n); \
char *d = (char*)p->ax; \
strcpy (d, s); \
sink (p); \
} while (0)
void f (void)
{
size_t r_1_2 = range (1, 2);
size_t r_2_3 = range (2, 3);
T (char, "12", r_1_2); // { dg-warning "\\\[-Warray-bounds" }
T (char, "123456789", r_2_3); // { dg-warning "\\\[-Warray-bounds" }
}
void g (void)
{
size_t r_1_2 = range (1, 2);
T (char, "12", r_1_2); // { dg-warning "\\\[-Warray-bounds" }
size_t r_2_3 = range (2, 3);
T (char, "123456789", r_2_3); // { dg-warning "\\\[-Warray-bounds" }
}
t.c: In function 'f':
t.c:32:3: warning: '__builtin_memcpy' forming offset [4, 10] is out of the
bounds [0, 4] [-Warray-bounds]
32 | T (char, "123456789", r_2_3); // { dg-warning "\\\[-Warray-bounds"
}
| ^
t.c: In function 'g':
t.c:38:3: warning: '__builtin_memcpy' forming offset 3 is out of the bounds [0,
3] [-Warray-bounds]
38 | T (char, "12", r_1_2); // { dg-warning "\\\[-Warray-bounds"
}
| ^
t.c:41:3: warning: '__builtin_memcpy' forming offset [4, 10] is out of the
bounds [0, 4] [-Warray-bounds]
41 | T (char, "123456789", r_2_3); // { dg-warning "\\\[-Warray-bounds"
}
| ^
