// Test to verify that the strlen() optimization doesn't make assumptions // about the static type of the object pointed to by its argument. See // the following thread for background: // https://gcc.gnu.org/ml/gcc-patches/2018-08/msg00260.html // { dg-do run } // { dg-options "-O2 -Wall -fdump-tree-optimized" } typedef __SIZE_TYPE__ size_t; void *operator new[] (size_t, void *p) { return p; } struct S { int x; char a[1]; char b[64]; }; __attribute__ ((noipa)) void init (char *s) { *s++ = '1'; *s++ = '\0'; } __attribute__ ((noipa)) void test_dynamic_type (S *p) { // The placement new call below isn't strictly valid because it // creates an object that is larger than the space of the p->a // subobject in which it is created. However, the corresponding // GIMPLE considers it valid and there's apparently no way to // distinguish invalid cases from ones like it that might be valid. // If/when GIMPLE changes to make this possible this test can be // removed. char *q = new (p->a) char [16]; // { dg-warning "\\\[-Wplacement-new" } init (q); if (0 == __builtin_strlen (q)) __builtin_abort(); } int main () { test_dynamic_type (new S); }