clang/test/Sema/tautological-unsigned-zero-compare.c

   1 // RUN: %clang_cc1 -fsyntax-only \
   2 // RUN:            -Wtautological-unsigned-zero-compare \
   3 // RUN:            -verify %s
   4 // RUN: %clang_cc1 -fsyntax-only \
   5 // RUN:            -verify=silence %s
   6 // RUN: %clang_cc1 -fsyntax-only \
   7 // RUN:            -Wtautological-unsigned-zero-compare \
   8 // RUN:            -verify -x c++ %s
   9 // RUN: %clang_cc1 -fsyntax-only \
  10 // RUN:            -verify=silence -x c++ %s
  11
  12 unsigned uvalue(void);
  13 signed int svalue(void);
  14
  15 #define macro(val) val
  16
  17 #ifdef __cplusplus
  18 template<typename T>
  19 void TFunc() {
  20   // Make sure that we do warn for normal variables in template functions !
  21   unsigned char c = svalue();
  22   if (c < 0) // expected-warning {{comparison of unsigned expression < 0 is always false}}
  23       return;
  24
  25   if (c < macro(0))
  26       return;
  27
  28   T v = svalue();
  29   if (v < 0)
  30       return;
  31 }
  32 #endif
  33
  34 int main(void)
  35 {
  36 #ifdef __cplusplus
  37   TFunc<unsigned char>();
  38   TFunc<unsigned short>();
  39 #endif
  40
  41   short s = svalue();
  42
  43   unsigned un = uvalue();
  44
  45   // silence-no-diagnostics
  46
  47   // Note: both sides are promoted to unsigned long prior to the comparison.
  48   if (s == 0UL)
  49       return 0;
  50   if (s != 0UL)
  51       return 0;
  52   if (s < 0UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
  53       return 0;
  54   if (s <= 0UL)
  55       return 0;
  56   if (s > 0UL)
  57       return 0;
  58   if (s >= 0UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
  59       return 0;
  60
  61   if (0UL == s)
  62       return 0;
  63   if (0UL != s)
  64       return 0;
  65   if (0UL < s)
  66       return 0;
  67   if (0UL <= s) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
  68       return 0;
  69   if (0UL > s) // expected-warning {{comparison of 0 > unsigned expression is always false}}
  70       return 0;
  71   if (0UL >= s)
  72       return 0;
  73
  74   if (un == 0)
  75       return 0;
  76   if (un != 0)
  77       return 0;
  78   if (un < 0) // expected-warning {{comparison of unsigned expression < 0 is always false}}
  79       return 0;
  80   if (un <= 0)
  81       return 0;
  82   if (un > 0)
  83       return 0;
  84   if (un >= 0) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
  85       return 0;
  86
  87   if (0 == un)
  88       return 0;
  89   if (0 != un)
  90       return 0;
  91   if (0 < un)
  92       return 0;
  93   if (0 <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
  94       return 0;
  95   if (0 > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
  96       return 0;
  97   if (0 >= un)
  98       return 0;
  99
 100   if (un == 0UL)
 101       return 0;
 102   if (un != 0UL)
 103       return 0;
 104   if (un < 0UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
 105       return 0;
 106   if (un <= 0UL)
 107       return 0;
 108   if (un > 0UL)
 109       return 0;
 110   if (un >= 0UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
 111       return 0;
 112
 113   if (0UL == un)
 114       return 0;
 115   if (0UL != un)
 116       return 0;
 117   if (0UL < un)
 118       return 0;
 119   if (0UL <= un) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
 120       return 0;
 121   if (0UL > un) // expected-warning {{comparison of 0 > unsigned expression is always false}}
 122       return 0;
 123   if (0UL >= un)
 124       return 0;
 125
 126
 127   signed int a = svalue();
 128
 129   if (a == 0)
 130       return 0;
 131   if (a != 0)
 132       return 0;
 133   if (a < 0)
 134       return 0;
 135   if (a <= 0)
 136       return 0;
 137   if (a > 0)
 138       return 0;
 139   if (a >= 0)
 140       return 0;
 141
 142   if (0 == a)
 143       return 0;
 144   if (0 != a)
 145       return 0;
 146   if (0 < a)
 147       return 0;
 148   if (0 <= a)
 149       return 0;
 150   if (0 > a)
 151       return 0;
 152   if (0 >= a)
 153       return 0;
 154
 155   if (a == 0UL)
 156       return 0;
 157   if (a != 0UL)
 158       return 0;
 159   if (a < 0UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
 160       return 0;
 161   if (a <= 0UL)
 162       return 0;
 163   if (a > 0UL)
 164       return 0;
 165   if (a >= 0UL) // expected-warning {{comparison of unsigned expression >= 0 is always true}}
 166       return 0;
 167
 168   if (0UL == a)
 169       return 0;
 170   if (0UL != a)
 171       return 0;
 172   if (0UL < a)
 173       return 0;
 174   if (0UL <= a) // expected-warning {{comparison of 0 <= unsigned expression is always true}}
 175       return 0;
 176   if (0UL > a) // expected-warning {{comparison of 0 > unsigned expression is always false}}
 177       return 0;
 178   if (0UL >= a)
 179       return 0;
 180
 181
 182   float fl = 0;
 183
 184   if (fl == 0)
 185       return 0;
 186   if (fl != 0)
 187       return 0;
 188   if (fl < 0)
 189       return 0;
 190   if (fl <= 0)
 191       return 0;
 192   if (fl > 0)
 193       return 0;
 194   if (fl >= 0)
 195       return 0;
 196
 197   if (0 == fl)
 198       return 0;
 199   if (0 != fl)
 200       return 0;
 201   if (0 < fl)
 202       return 0;
 203   if (0 <= fl)
 204       return 0;
 205   if (0 > fl)
 206       return 0;
 207   if (0 >= fl)
 208       return 0;
 209
 210   if (fl == 0UL)
 211       return 0;
 212   if (fl != 0UL)
 213       return 0;
 214   if (fl < 0UL)
 215       return 0;
 216   if (fl <= 0UL)
 217       return 0;
 218   if (fl > 0UL)
 219       return 0;
 220   if (fl >= 0UL)
 221       return 0;
 222
 223   if (0UL == fl)
 224       return 0;
 225   if (0UL != fl)
 226       return 0;
 227   if (0UL < fl)
 228       return 0;
 229   if (0UL <= fl)
 230       return 0;
 231   if (0UL > fl)
 232       return 0;
 233   if (0UL >= fl)
 234       return 0;
 235
 236
 237   double dl = 0;
 238
 239   if (dl == 0)
 240       return 0;
 241   if (dl != 0)
 242       return 0;
 243   if (dl < 0)
 244       return 0;
 245   if (dl <= 0)
 246       return 0;
 247   if (dl > 0)
 248       return 0;
 249   if (dl >= 0)
 250       return 0;
 251
 252   if (0 == dl)
 253       return 0;
 254   if (0 != dl)
 255       return 0;
 256   if (0 < dl)
 257       return 0;
 258   if (0 <= dl)
 259       return 0;
 260   if (0 > dl)
 261       return 0;
 262   if (0 >= dl)
 263       return 0;
 264
 265   if (dl == 0UL)
 266       return 0;
 267   if (dl != 0UL)
 268       return 0;
 269   if (dl < 0UL)
 270       return 0;
 271   if (dl <= 0UL)
 272       return 0;
 273   if (dl > 0UL)
 274       return 0;
 275   if (dl >= 0UL)
 276       return 0;
 277
 278   if (0UL == dl)
 279       return 0;
 280   if (0UL != dl)
 281       return 0;
 282   if (0UL < dl)
 283       return 0;
 284   if (0UL <= dl)
 285       return 0;
 286   if (0UL > dl)
 287       return 0;
 288   if (0UL >= dl)
 289       return 0;
 290
 291   return 1;
 292 }