pointer-addition.c
2.5 KB
// RUN: %clang_cc1 %s -fsyntax-only -verify -pedantic -Wextra -std=c11
// RUN: %clang_cc1 %s -fsyntax-only -triple i686-unknown-unknown -verify -pedantic -Wextra -std=c11
// RUN: %clang_cc1 %s -fsyntax-only -triple x86_64-unknown-unknown -verify -pedantic -Wextra -std=c11
#include <stdint.h>
typedef struct S S; // expected-note 4 {{forward declaration of 'struct S'}}
extern _Atomic(S*) e;
void a(S* b, void* c) {
void (*fp)(int) = 0;
b++; // expected-error {{arithmetic on a pointer to an incomplete type}}
b += 1; // expected-error {{arithmetic on a pointer to an incomplete type}}
c++; // expected-warning {{arithmetic on a pointer to void is a GNU extension}}
c += 1; // expected-warning {{arithmetic on a pointer to void is a GNU extension}}
c--; // expected-warning {{arithmetic on a pointer to void is a GNU extension}}
c -= 1; // expected-warning {{arithmetic on a pointer to void is a GNU extension}}
(void) c[1]; // expected-warning {{subscript of a pointer to void is a GNU extension}}
b = 1+b; // expected-error {{arithmetic on a pointer to an incomplete type}}
/* The next couple tests are only pedantic warnings in gcc */
void (*d)(S*,void*) = a;
d += 1; // expected-warning {{arithmetic on a pointer to the function type 'void (S *, void *)' (aka 'void (struct S *, void *)') is a GNU extension}}
d++; // expected-warning {{arithmetic on a pointer to the function type 'void (S *, void *)' (aka 'void (struct S *, void *)') is a GNU extension}}
d--; // expected-warning {{arithmetic on a pointer to the function type 'void (S *, void *)' (aka 'void (struct S *, void *)') is a GNU extension}}
d -= 1; // expected-warning {{arithmetic on a pointer to the function type 'void (S *, void *)' (aka 'void (struct S *, void *)') is a GNU extension}}
(void)(1 + d); // expected-warning {{arithmetic on a pointer to the function type 'void (S *, void *)' (aka 'void (struct S *, void *)') is a GNU extension}}
e++; // expected-error {{arithmetic on a pointer to an incomplete type}}
intptr_t i = (intptr_t)b;
char *f = (char*)0 + i; // expected-warning {{arithmetic on a null pointer treated as a cast from integer to pointer is a GNU extension}}
// Cases that don't match the GNU inttoptr idiom get a different warning.
f = (char*)0 - i; // expected-warning {{performing pointer arithmetic on a null pointer has undefined behavior}}
int *g = (int*)0 + i; // expected-warning {{performing pointer arithmetic on a null pointer has undefined behavior}}
}