clang/test/AST/ByteCode/loops.cpp

   1 // RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++14 -verify %s
   2 // RUN: %clang_cc1 -std=c++14 -verify=ref %s
   3 // RUN: %clang_cc1 -fexperimental-new-constant-interpreter -std=c++20 -verify=expected-cpp20 %s
   4 // RUN: %clang_cc1 -std=c++20 -verify=ref %s
   5
   6 namespace WhileLoop {
   7   constexpr int f() {
   8     int i = 0;
   9     while(false) {
  10       i = i + 1;
  11     }
  12     return i;
  13   }
  14   static_assert(f() == 0, "");
  15
  16
  17   constexpr int f2() {
  18     int i = 0;
  19     while(i != 5) {
  20       i = i + 1;
  21     }
  22     return i;
  23   }
  24   static_assert(f2() == 5, "");
  25
  26   constexpr int f3() {
  27     int i = 0;
  28     while(true) {
  29       i = i + 1;
  30
  31       if (i == 5)
  32         break;
  33     }
  34     return i;
  35   }
  36   static_assert(f3() == 5, "");
  37
  38   constexpr int f4() {
  39     int i = 0;
  40     while(i != 5) {
  41
  42       i = i + 1;
  43       continue;
  44       i = i - 1;
  45     }
  46     return i;
  47   }
  48   static_assert(f4() == 5, "");
  49
  50
  51   constexpr int f5(bool b) {
  52     int i = 0;
  53
  54     while(true) {
  55       if (!b) {
  56         if (i == 5)
  57           break;
  58       }
  59
  60       if (b) {
  61         while (i != 10) {
  62           i = i + 1;
  63           if (i == 8)
  64             break;
  65
  66           continue;
  67         }
  68       }
  69
  70       if (b)
  71         break;
  72
  73       i = i + 1;
  74       continue;
  75     }
  76
  77     return i;
  78   }
  79   static_assert(f5(true) == 8, "");
  80   static_assert(f5(false) == 5, "");
  81
  82 #if 0
  83   /// FIXME: This is an infinite loop, which should
  84   ///   be rejected.
  85   constexpr int f6() {
  86     while(true);
  87   }
  88 #endif
  89 };
  90
  91 namespace DoWhileLoop {
  92
  93   constexpr int f() {
  94     int i = 0;
  95     do {
  96       i = i + 1;
  97     } while(false);
  98     return i;
  99   }
 100   static_assert(f() == 1, "");
 101
 102   constexpr int f2() {
 103     int i = 0;
 104     do {
 105       i = i + 1;
 106     } while(i != 5);
 107     return i;
 108   }
 109   static_assert(f2() == 5, "");
 110
 111
 112   constexpr int f3() {
 113     int i = 0;
 114     do {
 115       i = i + 1;
 116       if (i == 5)
 117         break;
 118     } while(true);
 119     return i;
 120   }
 121   static_assert(f3() == 5, "");
 122
 123   constexpr int f4() {
 124     int i = 0;
 125     do {
 126       i = i + 1;
 127       continue;
 128       i = i - 1;
 129     } while(i != 5);
 130     return i;
 131   }
 132   static_assert(f4() == 5, "");
 133
 134   constexpr int f5(bool b) {
 135     int i = 0;
 136
 137     do {
 138       if (!b) {
 139         if (i == 5)
 140           break;
 141       }
 142
 143       if (b) {
 144         do {
 145           i = i + 1;
 146           if (i == 8)
 147             break;
 148
 149           continue;
 150         } while (i != 10);
 151       }
 152
 153       if (b)
 154         break;
 155
 156       i = i + 1;
 157       continue;
 158     } while(true);
 159
 160     return i;
 161   }
 162   static_assert(f5(true) == 8, "");
 163   static_assert(f5(false) == 5, "");
 164
 165 #if __cplusplus >= 202002L
 166   constexpr int f6() {
 167     int i;
 168     do {
 169       i = 5;
 170       break;
 171     } while (true);
 172     return i;
 173   }
 174   static_assert(f6() == 5, "");
 175 #endif
 176
 177 #if 0
 178   /// FIXME: This is an infinite loop, which should
 179   ///   be rejected.
 180   constexpr int f7() {
 181     while(true);
 182   }
 183 #endif
 184 };
 185
 186 namespace ForLoop {
 187   constexpr int f() {
 188     int i = 0;
 189     for (;false;) {
 190       i = i + 1;
 191     }
 192     return i;
 193   }
 194   static_assert(f() == 0, "");
 195
 196   constexpr int f2() {
 197     int m = 0;
 198     for (int i = 0; i < 10; i = i + 1){
 199       m = i;
 200     }
 201     return m;
 202   }
 203   static_assert(f2() == 9, "");
 204
 205   constexpr int f3() {
 206     int i = 0;
 207     for (; i != 5; i = i + 1);
 208     return i;
 209   }
 210   static_assert(f3() == 5, "");
 211
 212   constexpr int f4() {
 213     int i = 0;
 214     for (;;) {
 215       i = i + 1;
 216
 217       if (i == 5)
 218         break;
 219     }
 220     return i;
 221   }
 222   static_assert(f4() == 5, "");
 223
 224   constexpr int f5() {
 225     int i = 0;
 226     for (;i != 5;) {
 227       i = i + 1;
 228       continue;
 229       i = i - 1;
 230     }
 231     return i;
 232   }
 233   static_assert(f5() == 5, "");
 234
 235   constexpr int f6(bool b) {
 236     int i = 0;
 237
 238     for (;true;) {
 239       if (!b) {
 240         if (i == 5)
 241           break;
 242       }
 243
 244       if (b) {
 245         for (; i != 10; i = i + 1) {
 246           if (i == 8)
 247             break;
 248           continue;
 249         }
 250       }
 251
 252       if (b)
 253         break;
 254
 255       i = i + 1;
 256       continue;
 257     }
 258
 259     return i;
 260   }
 261   static_assert(f6(true) == 8, "");
 262   static_assert(f6(false) == 5, "");
 263
 264 #if 0
 265   /// FIXME: This is an infinite loop, which should
 266   ///   be rejected.
 267   constexpr int f6() {
 268     for(;;);
 269   }
 270 #endif
 271
 272 };
 273
 274 namespace RangeForLoop {
 275   constexpr int localArray() {
 276     int a[] = {1,2,3,4};
 277     int s = 0;
 278     for(int i : a) {
 279       s += i;
 280     }
 281     return s;
 282   }
 283   static_assert(localArray() == 10, "");
 284
 285   constexpr int localArray2() {
 286     int a[] = {1,2,3,4};
 287     int s = 0;
 288     for(const int &i : a) {
 289       s += i;
 290     }
 291     return s;
 292   }
 293   static_assert(localArray2() == 10, "");
 294
 295   constexpr int nested() {
 296     int s = 0;
 297     for (const int i : (int[]){1,2,3,4}) {
 298       int a[] = {i, i};
 299       for(int m : a) {
 300         s += m;
 301       }
 302     }
 303     return s;
 304   }
 305   static_assert(nested() == 20, "");
 306
 307   constexpr int withBreak() {
 308     int s = 0;
 309     for (const int &i: (bool[]){false, true}) {
 310       if (i)
 311         break;
 312       s++;
 313     }
 314     return s;
 315   }
 316   static_assert(withBreak() == 1, "");
 317
 318   constexpr void NoBody() {
 319     for (const int &i: (bool[]){false, true}); // expected-warning {{empty body}} \
 320                                                // expected-note {{semicolon on a separate line}} \
 321                                                // expected-cpp20-warning {{empty body}} \
 322                                                // expected-cpp20-note {{semicolon on a separate line}} \
 323                                                // ref-warning {{empty body}} \
 324                                                // ref-note {{semicolon on a separate line}}
 325   }
 326 }
 327
 328 namespace Scopes {
 329   constexpr int foo() {
 330     int n = 0;
 331     {
 332       int m = 12;
 333     for (int i = 0;i < 10;++i) {
 334
 335       {
 336         int a  = 10;
 337         {
 338           int b = 20;
 339           {
 340             int c = 30;
 341             continue;
 342           }
 343         }
 344       }
 345     }
 346     ++m;
 347     n = m;
 348     }
 349
 350     ++n;
 351     return n;
 352   }
 353   static_assert(foo() == 14, "");
 354 }