1 // RUN: %clang_cc1 -fsyntax-only -verify %s 2 // RUN: %clang_cc1 -fsyntax-only -verify -Wtautological-undefined-compare %s 3 // RUN: %clang_cc1 -fsyntax-only -verify -Wno-tautological-compare -Wtautological-undefined-compare %s 4 // RUN: %clang_cc1 -fsyntax-only -verify -Wtautological-compare %s 5 6 void 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 14 class 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 36 namespace 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
