clang/test/SemaCXX/bool-compare.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify %s
   2
   3
   4 void f(int x, int y, int z) {
   5
   6   bool a,b;
   7
   8   if(b > true)    {} // expected-warning {{comparison of true with expression of type 'bool' is always false}}
   9   if(b < true)    {} // no warning
  10   if(b >= true)   {} // no warning
  11   if(b <= true)   {} // expected-warning {{comparison of true with expression of type 'bool' is always true}}
  12   if(b == true)   {} // no warning
  13   if(b != true)   {} // no warning
  14
  15   if(b > false)   {} // no warning
  16   if(b < false)   {} // expected-warning {{comparison of false with expression of type 'bool' is always false}}
  17   if(b >= false)  {} // expected-warning {{comparison of false with expression of type 'bool' is always true}}
  18   if(b <= false)  {} // no warning
  19   if(b == false)  {} // no warning
  20   if(b != false)  {} // no warning
  21
  22   if(b > 1U){} // expected-warning {{comparison of constant 1 with expression of type 'bool' is always false}}
  23
  24   if (a > b)      {} // no warning
  25   if (a < b)      {} // no warning
  26   if (a >= b)     {} // no warning
  27   if (a <= b)     {} // no warning
  28   if (a == b)     {} // no warning
  29   if (a != b)     {} // no warning
  30
  31   if (a > 0) {} // no warning
  32   if (a > 1) {} // expected-warning {{comparison of constant 1 with expression of type 'bool' is always false}}
  33   if (a > 2) {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always false}}
  34
  35   if (a >= 0) {} // expected-warning {{comparison of constant 0 with expression of type 'bool' is always true}}
  36   if (a >= 1) {} // no warning
  37   if (a >= 2) {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always false}}
  38   if (a >= -1) {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always true}}
  39
  40   if (a <= 0) {} // no warning
  41   if (a <= 1) {} // expected-warning {{comparison of constant 1 with expression of type 'bool' is always true}}
  42   if (a <= 2) {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always true}}
  43   if (a <= -1) {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always false}}
  44
  45   if (!a > 0)     {} // no warning
  46   if (!a > 1)     {} // expected-warning {{comparison of constant 1 with expression of type 'bool' is always false}}
  47   if (!a > 2)     {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always false}}
  48   if (!a > y)     {} // no warning
  49   if (!a > b)     {} // no warning
  50   if (!a > -1)    {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always true}}
  51
  52   if (!a < 0)     {} // expected-warning {{comparison of constant 0 with expression of type 'bool' is always false}}
  53   if (!a < 1)     {} // no warning
  54   if (!a < 2)     {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always true}}
  55   if (!a < y)     {} // no warning
  56   if (!a < b)     {} // no warning
  57   if (!a < -1)    {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always false}}
  58
  59   if (!a >= 0)    {} // expected-warning {{comparison of constant 0 with expression of type 'bool' is always true}}
  60   if (!a >= 1)    {} // no warning
  61   if (!a >= 2)    {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always false}}
  62   if (!a >= y)    {} // no warning
  63   if (!a >= b)    {} // no warning
  64   if (!a >= -1)   {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always true}}
  65
  66   if (!a <= 0)    {} // no warning
  67   if (!a <= 1)    {} // expected-warning {{comparison of constant 1 with expression of type 'bool' is always true}}
  68   if (!a <= 2)    {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always true}}
  69   if (!a <= y)    {} // no warning
  70   if (!a <= b)    {} // no warning
  71   if (!a <= -1)   {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always false}}
  72
  73   if ((a||b) > 0) {} // no warning
  74   if ((a||b) > 1) {} // expected-warning {{comparison of constant 1 with expression of type 'bool' is always false}}
  75   if ((a||b) > 4) {} // expected-warning {{comparison of constant 4 with expression of type 'bool' is always false}}
  76   if ((a||b) > -1) {}// expected-warning {{comparison of constant -1 with expression of type 'bool' is always true}}
  77
  78   if ((a&&b) > 0) {} // no warning
  79   if ((a&&b) > 1) {} // expected-warning {{comparison of constant 1 with expression of type 'bool' is always false}}
  80   if ((a&&b) > 4) {} // expected-warning {{comparison of constant 4 with expression of type 'bool' is always false}}
  81
  82   if ((a<y) > 0)  {} // no warning
  83   if ((a<y) > 1)  {} // expected-warning {{comparison of constant 1 with expression of type 'bool' is always false}}
  84   if ((a<y) > 4)  {} // expected-warning {{comparison of constant 4 with expression of type 'bool' is always false}}
  85   if ((a<y) > z)  {} // no warning
  86   if ((a<y) > -1) {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always true}}
  87
  88   if ((a<y) == 0) {} // no warning
  89   if ((a<y) == 1) {} // no warning
  90   if ((a<y) == 2) {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always false}}
  91   if ((a<y) == z) {} // no warning
  92   if ((a<y) == -1) {}// expected-warning {{comparison of constant -1 with expression of type 'bool' is always false}}
  93
  94   if ((a<y) != 0) {} // no warning
  95   if ((a<y) != 1) {} // no warning
  96   if ((a<y) != 2) {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always true}}
  97   if ((a<y) != z) {} // no warning
  98   if ((a<y) != -1) {}// expected-warning {{comparison of constant -1 with expression of type 'bool' is always true}}
  99
 100   if ((a<y) == z) {} // no warning
 101   if (a>y<z)      {} // expected-warning {{comparisons like 'X<=Y<=Z' don't have their mathematical meaning}}
 102   if ((a<y) > z)  {} // no warning
 103   if((a<y)>(z<y)) {} // no warning
 104   if((a<y)==(z<y)){} // no warning
 105   if((a<y)!=(z<y)){} // no warning
 106   if((z==x)<(y==z)){}  // no warning
 107   if((a<y)!=((z==x)<(y==z))){} // no warning
 108
 109
 110   if (0 > !a)     {} // expected-warning {{comparison of constant 0 with expression of type 'bool' is always false}}
 111   if (1 > !a)     {} // no warning
 112   if (2 > !a)     {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always true}}
 113   if (y > !a)     {} // no warning
 114   if (-1 > !a)    {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always false}}
 115
 116   if (0 < !a)     {} // no warning
 117   if (1 < !a)     {} // expected-warning {{comparison of constant 1 with expression of type 'bool' is always false}}
 118   if (2 < !a)     {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always false}}
 119   if (y < !a)     {} // no warning
 120   if (-1 < !a)    {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always true}}
 121
 122
 123   if (0 >= !a)    {} // no warning
 124   if (1 >= !a)    {} // expected-warning {{comparison of constant 1 with expression of type 'bool' is always true}}
 125   if (2 >= !a)    {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always true}}
 126   if (y >= !a)    {} // no warning
 127   if (-1 >= !a)   {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always false}}
 128
 129   if (0 <= !a)    {} // expected-warning {{comparison of constant 0 with expression of type 'bool' is always true}}
 130   if (1 <= !a)    {} // no warning
 131   if (2 <= !a)    {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always false}}
 132   if (y <= !a)    {} //
 133   if (-1 <= !a)   {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always true}}
 134
 135   if (0 > (a||b)) {} // expected-warning {{comparison of constant 0 with expression of type 'bool' is always false}}
 136   if (1 > (a||b)) {} // no warning
 137   if (4 > (a||b)) {} // expected-warning {{comparison of constant 4 with expression of type 'bool' is always true}}
 138
 139   if (0 > (a&&b)) {} // expected-warning {{comparison of constant 0 with expression of type 'bool' is always false}}
 140   if (1 > (a&&b)) {} // no warning
 141   if (4 > (a&&b)) {} // expected-warning {{comparison of constant 4 with expression of type 'bool' is always true}}
 142
 143   if (0 > (a<y))  {} // expected-warning {{comparison of constant 0 with expression of type 'bool' is always false}}
 144   if (1 > (a<y))  {} // no warning
 145   if (4 > (a<y))  {} // expected-warning {{comparison of constant 4 with expression of type 'bool' is always true}}
 146   if (z > (a<y))  {} //
 147   if (-1 > (a<y)) {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always false}}
 148
 149   if (0 == (a<y)) {} // no warning
 150   if (1 == (a<y)) {} // no warning
 151   if (2 == (a<y)) {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always false}}
 152   if (z == (a<y)) {} // no warning
 153   if (-1 == (a<y)){} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always false}}
 154
 155   if (0 !=(a<y))  {} // no warning
 156   if (1 !=(a<y))  {} // no warning
 157   if (2 !=(a<y))  {} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always true}}
 158   if (z !=(a<y))  {} // no warning
 159   if (-1 !=(a<y)) {} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always true}}
 160
 161   if (z ==(a<y))  {} // no warning
 162   if (z<a>y)      {} // expected-warning {{comparisons like 'X<=Y<=Z' don't have their mathematical meaning}}
 163   if (z > (a<y))  {} // no warning
 164   if((z<y)>(a<y)) {} // no warning
 165   if((z<y)==(a<y)){} // no warning
 166   if((z<y)!=(a<y)){} // no warning
 167   if((y==z)<(z==x)){} // no warning
 168   if(((z==x)<(y==z))!=(a<y)){}  // no warning
 169
 170   if(((z==x)<(-1==z))!=(a<y)){} // no warning
 171   if(((z==x)<(z==-1))!=(a<y)){} // no warning
 172   if(((z==x)<-1)!=(a<y)){} // expected-warning {{comparison of constant -1 with expression of type 'bool' is always false}}
 173   if(((z==x)< 2)!=(a<y)){} // expected-warning {{comparison of constant 2 with expression of type 'bool' is always true}}
 174   if(((z==x)<(z>2))!=(a<y)){} // no warning
 175
 176 }
 177
 178
 179 template<typename T, typename U, typename V> struct X6 {
 180   U f(T t, U u, V v) {
 181     // IfStmt
 182     if (t > 0)
 183       return u;
 184     else {
 185       if (t < 0)
 186         return v; // expected-error{{cannot initialize return object of type}}
 187     }
 188     bool r;
 189     // FIXME: We should warn here, DiagRuntimeBehavior does currently not detect this.
 190     if(r<0){}
 191
 192     if (T x = t) {
 193       t = x;
 194     }
 195     return v; // expected-error{{cannot initialize return object of type}}
 196   }
 197 };
 198
 199 struct ConvertibleToInt {
 200   operator int() const;
 201 };
 202
 203 template struct X6<ConvertibleToInt, float, char>;
 204 template struct X6<bool, int, int*>; // expected-note{{instantiation}}
 205
 206
 207