1 // RUN: %clang_cc1 %s -fsyntax-only -verify -pedantic -Wextra -std=c++11
2 // RUN: %clang_cc1 %s -fsyntax-only -triple i686-unknown-unknown -verify -pedantic -Wextra -std=c++11
3 // RUN: %clang_cc1 %s -fsyntax-only -triple x86_64-unknown-unknown -verify -pedantic -Wextra -std=c++11
4 
5 #include <stdint.h>
6 
7 void f(intptr_t offset) {
8   // A zero offset from a nullptr is OK.
9   char *f = (char*)nullptr + 0;
10   int *g = (int*)0 + 0;
11   f = (char*)nullptr - 0;
12   g = (int*)nullptr - 0;
13   // adding other values is undefined.
14   f = (char*)nullptr + offset; // expected-warning {{arithmetic on a null pointer treated as a cast from integer to pointer is a GNU extension}}
15   // Cases that don't match the GNU inttoptr idiom get a different warning.
16   f = (char*)0 - offset; // expected-warning {{performing pointer arithmetic on a null pointer has undefined behavior if the offset is nonzero}}
17   g = (int*)0 + offset; // expected-warning {{performing pointer arithmetic on a null pointer has undefined behavior if the offset is nonzero}}
18 }
19 
20 // Value-dependent pointer arithmetic should not produce a nullptr warning.
21 template<char *P>
22 char* g(intptr_t offset) {
23   return P + offset;
24 }
25 
26 // Value-dependent offsets should not produce a nullptr warning.
27 template<intptr_t N>
28 char *h() {
29   return (char*)nullptr + N;
30 }
31