/* PR middle-end/94195 - missing warning reading a smaller object via an lvalue of a larger type { dg-do compile } { dg-options "-O2 -Wall" } { dg-require-effective-target alloca } */ typedef __INT16_TYPE__ int16_t; typedef __SIZE_TYPE__ size_t; void* alloca (size_t); void sink (void*); void byte_store_to_decl (void) { struct S6 { char a[6]; } s; // { dg-message "at offset 6 into object 's' of size 6" "note" } char *p = (char*)&s; p[0] = 0; p[1] = 1; p[2] = 2; p[3] = 3; p[4] = 4; p[5] = 5; p[6] = 6; // { dg-warning "array subscript 6 is outside array bounds of 'struct S6\\\[1]" } sink (&s); } void word_store_to_decl (void) { struct S6 { char a[6]; } s; // { dg-message "at offset 5 into object 's' of size 6" "note" } char *p = (char*)&s; int16_t *q = (int16_t*)(p + 1); q[0] = 0; q[1] = 1; q[2] = 2; // { dg-warning "array subscript 'int16_t {aka short int}\\\[2]' is partly outside array bounds of 'struct S6\\\[1]'" } sink (&s); } void word_store_to_alloc (void) { struct S6 { char a[6]; } *p; p = alloca (sizeof *p); // { dg-message "at offset 5 into object of size 6 allocated by 'alloca'" "note" } int16_t *q = (int16_t*)((char*)p + 1); q[0] = 0; q[1] = 1; q[2] = 2; // { dg-warning "array subscript 'int16_t {aka short int}\\\[2]' is partly outside array bounds of 'unsigned char\\\[6]'" } sink (p); }