/* PR middle-end/95667 - unintended warning for memset writing across multiple members { dg-do compile } { dg-options "-O2 -Wall" } { dg-require-effective-target alloca } */ extern void sink (void*); struct S1 { char a[3], b[5]; }; void warn_strcpy_s1 (void) { struct S1 *p = __builtin_malloc (sizeof *p); char s[] = "1234567"; __builtin_strcpy (p->a, s); // { dg-warning "\\\[-Wstringop-overflow" } sink (p); } void nowarn_memset_s1 (void) { struct S1 *p = __builtin_malloc (sizeof *p); __builtin_memset (p->a, 0, 8); // { dg-bogus "\\\[-Wstringop-overflow" } sink (p); } struct S2 { char a[2], b[2][2], c[3]; }; void nowarn_memset_s2 (void) { struct S2 *p = __builtin_malloc (sizeof *p); __builtin_memset (p->a, 0, sizeof *p); sink (p); __builtin_memset (p->b, 0, 7); sink (p); __builtin_memset (&p->b[0], 0, 7); sink (p); __builtin_memset (&p->b[1], 0, 5); sink (p); __builtin_memset (&p->b[0][0], 0, 7); sink (p); __builtin_memset (&p->b[0][1], 0, 6); sink (p); __builtin_memset (&p->b[1][0], 0, 5); sink (p); __builtin_memset (&p->b[1][1], 0, 4); sink (p); } void warn_memset_s2 (void) { const unsigned n = sizeof (struct S2); struct S2 *p = __builtin_malloc (n); /* These should trigger -Wstringop-overflow rather than -Warray-bounds but the main purpose of the test is to verify the absence of warnings above so the exact warning for these overflwing calls isn't important here. */ __builtin_memset (p->a, 0, n + 1); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" } sink (p); __builtin_memset (p->b, 0, 8); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" } sink (p); __builtin_memset (&p->b[0], 0, 8); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" } sink (p); __builtin_memset (&p->b[0][0], 0, 8); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" } sink (p); __builtin_memset (&p->b[1], 0, 6); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" } sink (p); __builtin_memset (&p->b[0][1], 0, 7); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" } sink (p); } void nowarn_vl_struct (unsigned n) { if (n < 3 || 5 < n) n = 3; struct V { char a[3], b[n], c[7]; } v; __builtin_memset (v.a, 0, 15); sink (&v); __builtin_memset (v.b, 0, 12); sink (&v); __builtin_memset (v.c, 0, 7); sink (&v); __builtin_memset (v.a, 0, 16); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" } sink (&v); __builtin_memset (v.b, 0, 13); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" } sink (&v); /* The &V.C argument is represented as a variable offset from the beginning of the allocated object and there's no good way to figure out from its variable offset that it's base is the C member: s.1_12 = __builtin_alloca_with_align (prephitmp_24, 8); _9 = s.1_12 + prephitmp_27; __builtin_memset (_9, 0, 2); */ __builtin_memset (v.c, 0, 8); // { dg-warning "\\\[-Warray-bounds|-Wstringop-overflow" "pr?????" { xfail *-*-* } } sink (&v); }