/* PR tree-optimization/101397 - spurious warning writing to the result of stpcpy minus 1 Verify warnings for indexing into a pointer returned from mempcpy. The call mempcpy(S1, S2, N) returns &S1[N]. { dg-do compile } { dg-options "-O2 -Wall" } */ typedef __SIZE_TYPE__ size_t; void* mempcpy (void*, const void*, size_t); extern char ax[], a3[3], a5[5], a7[7], *s; volatile int x; /* Verify warnings for indexing into the result of mempcpy with a source pointing to an array of unknown bound. */ void test_mempcpy_from_ptr (int i) { { char *p = mempcpy (ax, s, 5); x = p[-6]; // { dg-warning "\\\[-Warray-bounds" } x = p[-5]; x = p[-1]; x = p[ 0]; x = p[ 9]; } { char *p = mempcpy (a5, s, 3); x = p[-4]; // { dg-warning "\\\[-Warray-bounds" } x = p[-3]; x = p[-2]; x = p[-1]; x = p[ 0]; x = p[ 1]; x = p[ 2]; // { dg-warning "\\\[-Warray-bounds" } } { char *p = mempcpy (a5, s, 4); x = p[-5]; // { dg-warning "\\\[-Warray-bounds" } x = p[-4]; x = p[-3]; x = p[-2]; x = p[-1]; x = p[ 0]; x = p[ 1]; // { dg-warning "\\\[-Warray-bounds" } } { char *p = mempcpy (a5, s, 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]; if (i > -5) i = -5; x = p[i]; // { dg-warning "\\\[-Warray-bounds" } } } /* Verify warnings for indexing into the result of mempcpy with a source an array of size 5. */ void test_mempcpy_from_a5 (int i, int n, int n3_9) { { // The returned pointer is ax + 3 as specified by the bound. char *p = mempcpy (ax, a5, 3); x = p[-4]; // { dg-warning "\\\[-Warray-bounds" } x = p[-3]; x = p[-2]; x = p[ 0]; x = p[ 1]; x = p[ 2]; } { // The returned pointer is ax + 5. char *p = mempcpy (ax, a5, 5); x = p[-6]; // { dg-warning "\\\[-Warray-bounds" } x = p[-5]; x = p[-1]; x = p[ 0]; x = p[ 9]; } { //The returned pointer is in [ax, ax + 5] even though n is not known. char *p = mempcpy (ax, a5, n); x = p[-6]; // { dg-warning "\\\[-Warray-bounds" } x = p[-5]; x = p[-1]; x = p[ 0]; x = p[ 9]; } { // The returned pointer is a3 + 3. char *p = mempcpy (a3, a5, 3); x = p[-4]; // { dg-warning "\\\[-Warray-bounds" } x = p[-3]; x = p[-1]; x = p[ 0]; // { dg-warning "\\\[-Warray-bounds" } x = p[ 1]; // { dg-warning "\\\[-Warray-bounds" } } { // The returned pointer is in [a3, a3 + 3]. char *p = mempcpy (a3, a5, n); x = p[-4]; // { dg-warning "\\\[-Warray-bounds" } x = p[-3]; x = p[-2]; x = p[-1]; x = p[ 0]; x = p[ 2]; x = p[ 3]; // { dg-warning "\\\[-Warray-bounds" } } { if (n3_9 < 3 || 9 < n3_9) n3_9 = 3; // The returned pointer is a3. char *p = mempcpy (a3, a5, n3_9); x = p[-4]; // { dg-warning "\\\[-Warray-bounds" } x = p[-3]; x = p[-2]; x = p[-1]; x = p[ 0]; // { dg-warning "\\\[-Warray-bounds" } } { char *p = mempcpy (a3, a5, 3); 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" } } } /* Verify warnings for indexing into the result of mempcpy with a source an array of size 7. */ void test_mempcpy_from_a7 (int i, int n, int n3_9) { { // The returned pointer is ax + 5. char *p = mempcpy (ax, a7, 5); x = p[-6]; // { dg-warning "\\\[-Warray-bounds" } x = p[-5]; x = p[-1]; x = p[ 0]; x = p[ 9]; } { //The returned pointer is in [ax, ax + 7] even though n is not known. char *p = mempcpy (ax, a7, n); x = p[-8]; // { dg-warning "\\\[-Warray-bounds" } x = p[-7]; x = p[-1]; x = p[ 0]; x = p[ 9]; } { // The returned pointer is a5 + 3 as specified by the bound. char *p = mempcpy (a5, a7, 3); x = p[-4]; // { dg-warning "\\\[-Warray-bounds" } x = p[-3]; x = p[-2]; x = p[ 0]; x = p[ 1]; x = p[ 2]; // { dg-warning "\\\[-Warray-bounds" } } { // The returned pointer is a5 + 4. char *p = mempcpy (a5, a7, 4); x = p[-5]; // { dg-warning "\\\[-Warray-bounds" } x = p[-4]; x = p[-3]; x = p[-2]; x = p[-1]; x = p[ 0]; x = p[ 1]; // { dg-warning "\\\[-Warray-bounds" } } { // The returned pointer is in [a5, a5 + 5]. char *p = mempcpy (a5, a7, n); x = p[-6]; // { dg-warning "\\\[-Warray-bounds" } x = p[-5]; x = p[-3]; x = p[-2]; x = p[-1]; x = p[ 0]; x = p[ 4]; x = p[ 5]; // { dg-warning "\\\[-Warray-bounds" } } { if (n3_9 < 3 || 9 < n3_9) n3_9 = 3; // The returned pointer is in [a5 + 3, a5 + 5]. char *p = mempcpy (a5, a7, n3_9); x = p[-6]; // { dg-warning "\\\[-Warray-bounds" } x = p[-5]; x = p[-3]; x = p[-2]; x = p[-1]; x = p[ 0]; x = p[ 1]; x = p[ 2]; // { dg-warning "\\\[-Warray-bounds" } } { char *p = mempcpy (a5, a7, 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]; if (i > -5) i = -5; x = p[i]; // { dg-warning "\\\[-Warray-bounds" } } }