1 // RUN: %clang_cc1 %s -fsyntax-only -verify -pedantic -Wextra -std=c++11
2 
3 #include <stdint.h>
4 
5 void f(intptr_t offset) {
6   // A zero offset from a nullptr is OK.
7   char *f = (char*)nullptr + 0;
8   int *g = (int*)0 + 0;
9   f = (char*)nullptr - 0;
10   g = (int*)nullptr - 0;
11   // adding other values is undefined.
12   f = (char*)nullptr + offset; // expected-warning {{arithmetic on a null pointer treated as a cast from integer to pointer is a GNU extension}}
13   // Cases that don't match the GNU inttoptr idiom get a different warning.
14   f = (char*)0 - offset; // expected-warning {{performing pointer arithmetic on a null pointer has undefined behavior if the offset is nonzero}}
15   g = (int*)0 + offset; // expected-warning {{performing pointer arithmetic on a null pointer has undefined behavior if the offset is nonzero}}
16 }
17 
18 // Value-dependent pointer arithmetic should not produce a nullptr warning.
19 template<char *P>
20 char* g(intptr_t offset) {
21   return P + offset;
22 }
23 
24 // Value-dependent offsets should not produce a nullptr warning.
25 template<intptr_t N>
26 char *h() {
27   return (char*)nullptr + N;
28 }
29