clang/test/SemaCXX/warn-undefined-bool-conversion.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify %s
   2 // RUN: %clang_cc1 -fsyntax-only -verify -Wundefined-bool-conversion %s
   3 // RUN: %clang_cc1 -fsyntax-only -verify -Wno-bool-conversion -Wundefined-bool-conversion %s
   4 // RUN: %clang_cc1 -fsyntax-only -verify -Wbool-conversion %s
   5
   6 void test1(int &x) {
   7   if (x == 1) { }
   8   if (&x) { }
   9   // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  10
  11   if (!&x) { }
  12   // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  13 }
  14
  15 class test2 {
  16   test2() : x(y) {}
  17
  18   void foo() {
  19     if (this) { }
  20     // expected-warning@-1{{'this' pointer cannot be null in well-defined C++ code; pointer may be assumed to always convert to true}}
  21
  22     if (!this) { }
  23     // expected-warning@-1{{'this' pointer cannot be null in well-defined C++ code; pointer may be assumed to always convert to true}}
  24   }
  25
  26   void bar() {
  27     if (x == 1) { }
  28     if (&x) { }
  29     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  30
  31     if (!&x) { }
  32     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  33   }
  34
  35   int &x;
  36   int y;
  37 };
  38
  39 namespace function_return_reference {
  40   int& get_int();
  41   // expected-note@-1 3{{'get_int' returns a reference}}
  42   class B {
  43   public:
  44     static int &stat();
  45     // expected-note@-1 3{{'stat' returns a reference}}
  46     int &get();
  47     // expected-note@-1 6{{'get' returns a reference}}
  48   };
  49
  50   void test() {
  51     if (&get_int()) {}
  52     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  53     if (&(get_int())) {}
  54     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  55     if (!&get_int()) {}
  56     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  57
  58     if (&B::stat()) {}
  59     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  60     if (&(B::stat())) {}
  61     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  62     if (!&B::stat()) {}
  63     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  64
  65     B b;
  66     if (&b.get()) {}
  67     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  68     if (&(b.get())) {}
  69     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  70     if (!&b.get()) {}
  71     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  72
  73     B* b_ptr = &b;
  74     if (&b_ptr->get()) {}
  75     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  76     if (&(b_ptr->get())) {}
  77     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  78     if (!&b_ptr->get()) {}
  79     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  80
  81     int& (B::*m_ptr)() = &B::get;
  82     if (&(b.*m_ptr)()) {}
  83     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  84     if (&((b.*m_ptr)())) {}
  85     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  86     if (!&(b.*m_ptr)()) {}
  87     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  88
  89     int& (*f_ptr)() = &get_int;
  90     if (&(*f_ptr)()) {}
  91     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  92     if (&((*f_ptr)())) {}
  93     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  94     if (!&(*f_ptr)()) {}
  95     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
  96   }
  97 }
  98
  99 namespace macros {
 100   #define assert(x) if (x) {}
 101   #define zero_on_null(x) ((x) ? *(x) : 0)
 102
 103   void test(int &x) {
 104     // TODO: warn on assert(&x) but not on zero_on_null(&x)
 105     zero_on_null(&x);
 106     assert(zero_on_null(&x));
 107     assert(&x);
 108
 109     assert(&x && "Expecting valid reference");
 110     // expected-warning@-1{{reference cannot be bound to dereferenced null pointer in well-defined C++ code; pointer may be assumed to always convert to true}}
 111   }
 112
 113   class S {
 114     void test() {
 115       assert(this);
 116
 117       assert(this && "Expecting invalid reference");
 118       // expected-warning@-1{{'this' pointer cannot be null in well-defined C++ code; pointer may be assumed to always convert to true}}
 119     }
 120   };
 121 }