141 lines · cpp
1// RUN: %clang_cc1 -fsyntax-only -verify %s2// RUN: %clang_cc1 -fsyntax-only -verify -Wtautological-undefined-compare %s3// RUN: %clang_cc1 -fsyntax-only -verify -Wno-tautological-compare -Wtautological-undefined-compare %s4// RUN: %clang_cc1 -fsyntax-only -verify -Wtautological-compare %s5 6void test1(int &x) {7 if (x == 1) { }8 if (&x == 0) { }9 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}10 if (&x != 0) { }11 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}12}13 14class test2 {15 test2() : x(y) {}16 17 void foo() {18 if (this == 0) { }19 // expected-warning@-1{{'this' pointer cannot be null in well-defined C++ code; comparison may be assumed to always evaluate to false}}20 if (this != 0) { }21 // expected-warning@-1{{'this' pointer cannot be null in well-defined C++ code; comparison may be assumed to always evaluate to true}}22 }23 24 void bar() {25 if (x == 1) { }26 if (&x == 0) { }27 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}28 if (&x != 0) { }29 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}30 }31 32 int &x;33 int y;34};35 36namespace function_return_reference {37 int& get_int();38 // expected-note@-1 4{{'get_int' returns a reference}}39 class B {40 public:41 static int &stat();42 // expected-note@-1 4{{'stat' returns a reference}}43 int &get();44 // expected-note@-1 8{{'get' returns a reference}}45 };46 47 void test() {48 if (&get_int() == 0) {}49 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}50 if (&(get_int()) == 0) {}51 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}52 53 if (&get_int() != 0) {}54 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}55 if (&(get_int()) != 0) {}56 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}57 58 if (&B::stat() == 0) {}59 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}60 if (&(B::stat()) == 0) {}61 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}62 63 if (&B::stat() != 0) {}64 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}65 if (&(B::stat()) != 0) {}66 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}67 68 B b;69 if (&b.get() == 0) {}70 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}71 if (&(b.get()) == 0) {}72 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}73 74 if (&b.get() != 0) {}75 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}76 if (&(b.get()) != 0) {}77 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}78 79 B* b_ptr = &b;80 if (&b_ptr->get() == 0) {}81 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}82 if (&(b_ptr->get()) == 0) {}83 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}84 85 if (&b_ptr->get() != 0) {}86 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}87 if (&(b_ptr->get()) != 0) {}88 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}89 90 int& (B::*m_ptr)() = &B::get;91 if (&(b.*m_ptr)() == 0) {}92 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}93 if (&((b.*m_ptr)()) == 0) {}94 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}95 96 if (&(b.*m_ptr)() != 0) {}97 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}98 if (&((b.*m_ptr)()) != 0) {}99 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}100 101 int& (*f_ptr)() = &get_int;102 if (&(*f_ptr)() == 0) {}103 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}104 if (&((*f_ptr)()) == 0) {}105 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}106 107 if (&(*f_ptr)() != 0) {}108 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}109 if (&((*f_ptr)()) != 0) {}110 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}111 }112}113 114namespace macros {115 #define assert(x) if (x) {}116 117 void test(int &x) {118 assert(&x != 0);119 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}120 assert(&x == 0);121 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}122 assert(&x != 0 && "Expecting valid reference");123 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to true}}124 assert(&x == 0 && "Expecting invalid reference");125 // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; comparison may be assumed to always evaluate to false}}126 }127 128 class S {129 void test() {130 assert(this != 0);131 // expected-warning@-1{{'this' pointer cannot be null in well-defined C++ code; comparison may be assumed to always evaluate to true}}132 assert(this == 0);133 // expected-warning@-1{{'this' pointer cannot be null in well-defined C++ code; comparison may be assumed to always evaluate to false}}134 assert(this != 0 && "Expecting valid reference");135 // expected-warning@-1{{'this' pointer cannot be null in well-defined C++ code; comparison may be assumed to always evaluate to true}}136 assert(this == 0 && "Expecting invalid reference");137 // expected-warning@-1{{'this' pointer cannot be null in well-defined C++ code; comparison may be assumed to always evaluate to false}}138 }139 };140}141