/* Verify that structure return doesn't invoke memcpy on overlapping objects. */ extern void abort (void); typedef __SIZE_TYPE__ size_t; struct S { char stuff[1024]; }; union U { struct { int space; struct S s; } a; struct { struct S s; int space; } b; }; static struct S f(struct S *); static void g(union U *); int main() { union U u; u.b.s = f(&u.a.s); u.a.s = f(&u.b.s); g(&u); return 0; } static struct S f(struct S *p) { return *p; } static void g(union U *p) { } static void *memcpy(void *a, const void *b, size_t len) { if (a < b && a+len > b) abort (); if (b < a && b+len > a) abort (); return a; }