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// RUN: %clang_cc1 %s -fsyntax-only -verify -pedantic -Wextra -std=c++11 -isystem %S/Inputs
// RUN: %clang_cc1 %s -fsyntax-only -verify -pedantic -Wnull-pointer-subtraction -std=c++11 -isystem %S/Inputs
// RUN: %clang_cc1 %s -fsyntax-only -verify -pedantic -Wextra -std=c++11 -isystem %S/Inputs -Wsystem-headers -DSYSTEM_WARNINGS
// RUN: %clang_cc1 %s -fsyntax-only -verify -pedantic -Wnull-pointer-subtraction -std=c++11 -isystem %S/Inputs -Wsystem-headers -DSYSTEM_WARNINGS
#include <pointer-subtraction.h>
void a() {
char *f = (char *)0;
f = (char *)((char *)0 - f); // expected-warning {{performing pointer subtraction with a null pointer may have undefined behavior}}
f = (char *)(f - (char *)0); // expected-warning {{performing pointer subtraction with a null pointer may have undefined behavior}}
f = (char *)((char *)0 - (char *)0); // valid in C++
if (1)
f = (char *)((char *)0 - f); // expected-warning {{performing pointer subtraction with a null pointer may have undefined behavior}}
else
f = (char *)((char *)0 - f);
if (0)
f = (char *)((char *)0 - f);
else
f = (char *)((char *)0 - f); // expected-warning {{performing pointer subtraction with a null pointer may have undefined behavior}}
#ifndef SYSTEM_WARNINGS
SYSTEM_MACRO(f);
#else
SYSTEM_MACRO(f); // expected-warning {{performing pointer subtraction with a null pointer may have undefined behavior}}
#endif
}
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