| /* PR tree-optimization/101397 - spurious warning writing to the result |
| of stpcpy minus 1 |
| Verify warnings for indexing into a pointer returned from stpncpy. |
| The call stpncpy(S1, S2, N) returns the address of the copy of |
| the first NUL is it exists or &S1[N] otherwise. |
| { dg-do compile } |
| { dg-options "-O2 -Wall -Wno-stringop-truncation" } */ |
| |
| typedef __SIZE_TYPE__ size_t; |
| |
| __attribute__ ((alloc_size (1))) const void* alloc (size_t); |
| |
| void* memchr (const void*, int, size_t); |
| |
| void sink (int, ...); |
| |
| extern char ax[], a3[3], a5[5], a7[7], a9[9]; |
| |
| volatile int x; |
| |
| /* Verify warnings for indexing into the result of memchr. */ |
| |
| void test_memchr (int i, int n, int n3_5, int n3_9) |
| { |
| { |
| /* Because memchr never returns a past-the-end pointer the result |
| below is in [ax, ax + 4]. */ |
| const char *p = memchr (ax, x, 5); |
| x = p[-5]; // { dg-warning "\\\[-Warray-bounds" } |
| x = p[-4]; |
| x = p[-1]; |
| x = p[ 0]; |
| x = p[ 9]; |
| } |
| |
| { |
| // The returned pointer is in [ax, ax + n]. |
| const char *p = memchr (ax, x, n); |
| sink (p[-99], p[-6], p[-5], p[-4], p[-3], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4], p[5], p[6], p[7], p[8], p[99]); |
| } |
| |
| |
| { |
| // The returned pointer is in [a5, a5 + 2]. |
| const char *p = memchr (a5, x, 3); |
| x = p[-3]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4]); |
| x = p[ 5]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| { |
| // The returned pointer is a5 + 4. |
| const char *p = memchr (a5, x, 4); |
| x = p[-4]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-3], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4]); |
| x = p[ 5]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| { |
| // The returned pointer is in [a5, a5 + 4]. |
| const char *p = memchr (a5, x, n); |
| x = p[-5]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-4], p[-3], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4]); |
| x = p[ 5]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| { |
| if (n3_5 < 3 || 5 < n3_5) |
| n3_5 = 3; |
| |
| // The returned pointer is in [a7, a7 + 4]. |
| const char *p = memchr (a7, x, n3_5); |
| x = p[-5]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-4], p[-3], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4], p[5], p[6]); |
| x = p[7]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| { |
| if (n3_9 < 3 || 9 < n3_9) |
| n3_9 = 3; |
| |
| // The returned pointer is in [a5, a5 + 4]. |
| const char *p = memchr (a5, x, n3_9); |
| x = p[-5]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-4], p[-3], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4]); |
| x = p[ 5]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| { |
| const char *p = memchr (a5, x, 4); |
| |
| if (i > -1) i = -1; |
| x = p[i]; |
| |
| if (i > -2) i = -2; |
| x = p[i]; |
| |
| if (i > -3) i = -3; |
| x = p[i]; |
| |
| if (i > -4) i = -4; |
| x = p[i]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| } |
| |
| |
| void test_memchr_in_allocated (int i, int n, int n5_7, int n3_9) |
| { |
| if (n5_7 < 5 || 7 < n5_7) |
| n5_7 = 5; |
| |
| { |
| const char *s = alloc (n5_7); |
| const char *p = memchr (s, x, n); |
| x = p[-7]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-6], p[-6], p[-5], p[-4], p[-3], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4], p[5], p[6]); |
| x = p[7]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| { |
| const char *s = alloc (n5_7); |
| const char *p = memchr (s, x, n); |
| x = p[-7]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-6], p[-5], p[-4], p[-3], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4], p[5], p[6]); |
| x = p[7]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| { |
| const char *s = alloc (n5_7); |
| const char *p = memchr (s, x, n); |
| x = p[-7]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-6], p[-5], p[-4], p[-3], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4], p[5], p[6]); |
| x = p[7]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| { |
| const char *s = alloc (n5_7); |
| const char *p = memchr (s, x, n); |
| x = p[-7]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-6], p[-5], p[-3], p[-4], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4], p[5], p[6]); |
| x = p[7]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| { |
| const char *s = alloc (n5_7); |
| const char *p = memchr (s, x, n3_9); |
| x = p[-7]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-6], p[-5], p[-4], p[-3], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4], p[5], p[6]); |
| x = p[7]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| { |
| const char *s = alloc (n5_7); |
| const char *p = memchr (s, x, n3_9); |
| x = p[-7]; // { dg-warning "\\\[-Warray-bounds" } |
| sink (p[-6], p[-5], p[-4], p[-4], p[-2], p[-1], p[0]); |
| sink (p[1], p[2], p[3], p[4], p[5], p[6]); |
| x = p[7]; // { dg-warning "\\\[-Warray-bounds" } |
| } |
| |
| } |
