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
f(intptr_t offset)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>
g(intptr_t offset)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>
h()28 char *h() {
29 return (char*)nullptr + N;
30 }
31