/* PR middle-end/82646 - bogus -Wstringop-overflow with -D_FORTIFY_SOURCE=2 on strncpy with range to a member array { dg-do compile } { dg-options "-O2 -Wstringop-overflow -ftrack-macro-expansion=0" } */ #define bos(p) __builtin_object_size (p, 1) struct S { char a[5]; void (*pf)(void); }; /* Verify that none of the string function calls below triggers a warning. */ char* test_stpncpy_const_nowarn (struct S *p) { int n = sizeof p->a; return __builtin_stpncpy (p->a, "123456", n); } char* test_strncpy_const_nowarn (struct S *p) { int n = sizeof p->a; return __builtin_strncpy (p->a, "1234567", n); } char* test_stpncpy_chk_const_nowarn (struct S *p) { int n = sizeof p->a; return __builtin___stpncpy_chk (p->a, "12345678", n, bos (p->a)); } char* test_strncpy_chk_const_nowarn (struct S *p) { int n = sizeof p->a; return __builtin___strncpy_chk (p->a, "123456789", n, bos (p->a)); } char* test_stpncpy_range_nowarn (struct S *p, int n) { if (n < sizeof p->a) n = sizeof p->a; return __builtin_stpncpy (p->a, "123456", n); } char* test_strncpy_range_nowarn (struct S *p, int n) { if (n < sizeof p->a) n = sizeof p->a; return __builtin_strncpy (p->a, "1234567", n); } char* test_stpncpy_chk_range_nowarn (struct S *p, int n) { if (n < sizeof p->a) n = sizeof p->a; return __builtin___stpncpy_chk (p->a, "12345678", n, bos (p->a)); /* { dg-bogus "\\\[-Wstringop-overflow=]" } */ } char* test_strncpy_chk_range_nowarn (struct S *p, int n) { if (n < sizeof p->a) n = sizeof p->a; return __builtin___strncpy_chk (p->a, "123456789", n, bos (p->a)); /* { dg-bogus "\\\[-Wstringop-overflow=]" } */ } /* Verify that all of the string function calls below trigger a warning. */ char* test_stpncpy_const_warn (struct S *p) { int n = sizeof p->a; ++n; return __builtin_stpncpy (p->a, "123456", n); /* { dg-warning "\\\[-Wstringop-overflow=]" } */ } char* test_strncpy_const_warn (struct S *p) { int n = sizeof p->a; /* A call to strncpy() with a known string and small bound is folded into memcpy() which defeats the warning in this case since memcpy uses Object Size Type 0, i.e., the largest object that p->a may be a part of. Use a larger bound to get around this here. */ n += 11; return __builtin_strncpy (p->a, "1234567", n); /* { dg-warning "\\\[-Wstringop-overflow=]" } */ } char* test_stpncpy_chk_const_warn (struct S *p) { int n = sizeof p->a; ++n; return __builtin___stpncpy_chk (p->a, "12345678", n, bos (p->a)); /* { dg-warning "\\\[-Wstringop-overflow=]" } */ } char* test_strncpy_chk_const_warn (struct S *p) { int n = sizeof p->a; ++n; return __builtin___strncpy_chk (p->a, "123456789", n, bos (p->a)); /* { dg-warning "\\\[-Wstringop-overflow=]" } */ } char* test_stpncpy_range_warn (struct S *p, int n) { if (n < sizeof p->a + 1) n = sizeof p->a + 1; return __builtin_stpncpy (p->a, "123456", n); /* { dg-warning "\\\[-Wstringop-overflow=]" } */ } char* test_strncpy_range_warn (struct S *p, int n) { if (n < sizeof p->a + 1) n = sizeof p->a + 1; return __builtin_strncpy (p->a, "1234567", n); /* { dg-warning "\\\[-Wstringop-overflow=]" } */ } char* test_stpncpy_chk_range_warn (struct S *p, int n) { if (n < sizeof p->a + 1) n = sizeof p->a + 1; return __builtin___stpncpy_chk (p->a, "12345678", n, bos (p->a)); /* { dg-warning "\\\[-Wstringop-overflow=]" } */ } char* test_strncpy_chk_range_warn (struct S *p, int n) { if (n < sizeof p->a + 1) n = sizeof p->a + 1; return __builtin___strncpy_chk (p->a, "123456789", n, bos (p->a)); /* { dg-warning "\\\[-Wstringop-overflow=]" } */ }