clang/test/SemaCXX/warn-range-loop-analysis.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wall -Wrange-loop-bind-reference -Wno-unused -verify %s
   2 // RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wloop-analysis -verify %s
   3 // RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wrange-loop-analysis -verify %s
   4 // RUN: %clang_cc1 -fsyntax-only -std=c++11 -Wloop-analysis -fdiagnostics-parseable-fixits %s 2>&1 | FileCheck %s
   5
   6 template <typename return_type>
   7 struct Iterator {
   8   return_type operator*();
   9   Iterator operator++();
  10   bool operator!=(const Iterator);
  11 };
  12
  13 template <typename T>
  14 struct Container {
  15   typedef Iterator<T> I;
  16
  17   I begin();
  18   I end();
  19 };
  20
  21 struct Foo {};
  22 struct Bar {
  23   // Small trivially copyable types do not show a warning when copied in a
  24   // range-based for loop. This size ensures the object is not considered
  25   // small.
  26   char s[128];
  27   Bar(Foo);
  28   Bar(int);
  29   operator int();
  30 };
  31
  32 // Testing notes:
  33 // test0 checks that the full text of the warnings and notes is correct.  The
  34 //   rest of the tests checks a smaller portion of the text.
  35 // test1-6 are set in pairs, the odd numbers are the non-reference returning
  36 //   versions of the even numbers.
  37 // test7-9 use an array instead of a range object
  38 // tests use all four versions of the loop variable, const &T, const T, T&, and
  39 //   T.  Versions producing errors and are commented out.
  40 //
  41 // Conversion chart:
  42 //   double <=> int
  43 //   int    <=> Bar
  44 //   double  => Bar
  45 //   Foo     => Bar
  46 //
  47 // Conversions during tests:
  48 // test1-2
  49 //   int => int
  50 //   int => double
  51 //   int => Bar
  52 // test3-4
  53 //   Bar => Bar
  54 //   Bar => int
  55 // test5-6
  56 //   Foo => Bar
  57 // test7
  58 //   double => double
  59 //   double => int
  60 //   double => Bar
  61 // test8
  62 //   Foo => Foo
  63 //   Foo => Bar
  64 // test9
  65 //   Bar => Bar
  66 //   Bar => int
  67
  68 void test0() {
  69   Container<int> int_non_ref_container;
  70   Container<int&> int_container;
  71   Container<Bar&> bar_container;
  72
  73   for (const int &x : int_non_ref_container) {}
  74   // expected-warning@-1 {{loop variable 'x' binds to a temporary value produced by a range of type 'Container<int>'}}
  75   // expected-note@-2 {{use non-reference type 'int'}}
  76   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
  77
  78   for (const double &x : int_container) {}
  79   // expected-warning@-1 {{loop variable 'x' of type 'const double &' binds to a temporary constructed from type 'int &'}}
  80   // expected-note@-2 {{use non-reference type 'double' to make construction explicit or type 'const int &' to prevent copying}}
  81   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:21-[[@LINE-3]]:22}:""
  82
  83   for (const Bar x : bar_container) {}
  84   // expected-warning@-1 {{loop variable 'x' creates a copy from type 'const Bar'}}
  85   // expected-note@-2 {{use reference type 'const Bar &' to prevent copying}}
  86   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:18}:"&"
  87 }
  88
  89 void test1() {
  90   Container<int> A;
  91
  92   for (const int &&x : A) {}
  93   // No warning, rvalue-reference to the temporary
  94   for (const int &x : A) {}
  95   // expected-warning@-1 {{binds to a temporary value produced by a range}}
  96   // expected-note@-2 {{'int'}}
  97   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
  98   for (const int x : A) {}
  99   // No warning, non-reference type indicates copy is made
 100   for (int&& x : A) {}
 101   // No warning, rvalue-reference to the temporary
 102   //for (int &x : A) {}
 103   // Binding error
 104   for (int x : A) {}
 105   // No warning, non-reference type indicates copy is made
 106
 107   for (const double &&x : A) {}
 108   // No warning, rvalue-reference to the temporary
 109   for (const double &x : A) {}
 110   // expected-warning@-1 {{binds to a temporary value produced by a range}}
 111   // expected-note@-2 {{'double'}}
 112   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:21-[[@LINE-3]]:22}:""
 113   for (const double x : A) {}
 114   // No warning, non-reference type indicates copy is made
 115   for (double &&x : A) {}
 116   // No warning, rvalue-reference to the temporary
 117   //for (double &x : A) {}
 118   // Binding error
 119   for (double x : A) {}
 120   // No warning, non-reference type indicates copy is made
 121
 122   for (const Bar &&x : A) {}
 123   // No warning, rvalue-reference to the temporary
 124   for (const Bar &x : A) {}
 125   // expected-warning@-1 {{binds to a temporary value produced by a range}}
 126   // expected-note@-2 {{'Bar'}}
 127   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 128   for (const Bar x : A) {}
 129   // No warning, non-reference type indicates copy is made
 130   for (Bar &&x : A) {}
 131   // No warning, rvalue-reference to the temporary
 132   //for (Bar &x : A) {}
 133   // Binding error
 134   for (Bar x : A) {}
 135   // No warning, non-reference type indicates copy is made
 136 }
 137
 138 void test2() {
 139   Container<int&> B;
 140
 141   //for (const int &&x : B) {}
 142   // Binding error
 143   for (const int &x : B) {}
 144   // No warning, this reference is not a temporary
 145   for (const int x : B) {}
 146   // No warning on POD copy
 147   //for (int &x : B) {}
 148   // Binding error
 149   for (int &x : B) {}
 150   // No warning
 151   for (int x : B) {}
 152   // No warning
 153
 154   for (const double &&x : B) {}
 155   // expected-warning@-1 {{binds to a temporary constructed from}}
 156   // expected-note-re@-2 {{'double'{{.*}}'const int &'}}
 157   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:21-[[@LINE-3]]:23}:""
 158   for (const double &x : B) {}
 159   // expected-warning@-1 {{binds to a temporary constructed from}}
 160   // expected-note-re@-2 {{'double'{{.*}}'const int &'}}
 161   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:21-[[@LINE-3]]:22}:""
 162   for (const double x : B) {}
 163   for (double &&x : B) {}
 164   // expected-warning@-1 {{binds to a temporary constructed from}}
 165   // expected-note-re@-2 {{'double'{{.*}}'const int &'}}
 166   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:15-[[@LINE-3]]:17}:""
 167   //for (double &x : B) {}
 168   // Binding error
 169   for (double x : B) {}
 170   // No warning
 171
 172   for (const Bar &&x : B) {}
 173   // expected-warning@-1 {{binds to a temporary constructed from}}
 174   // expected-note@-2 {{'Bar'}}
 175   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:""
 176   for (const Bar &x : B) {}
 177   // expected-warning@-1 {{binds to a temporary constructed from}}
 178   // expected-note@-2 {{'Bar'}}
 179   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 180   for (const Bar x : B) {}
 181   for (Bar &&x : B) {}
 182   // expected-warning@-1 {{binds to a temporary constructed from}}
 183   // expected-note@-2 {{'Bar'}}
 184   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:""
 185   //for (Bar &x : B) {}
 186   // Binding error
 187   for (Bar x : B) {}
 188   // No warning
 189 }
 190
 191 void test3() {
 192   Container<Bar> C;
 193
 194   for (const Bar &&x : C) {}
 195   // No warning, rvalue-reference to the temporary
 196   for (const Bar &x : C) {}
 197   // expected-warning@-1 {{binds to a temporary value produced by a range}}
 198   // expected-note@-2 {{'Bar'}}
 199   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 200   for (const Bar x : C) {}
 201   // No warning, non-reference type indicates copy is made
 202   for (Bar &&x : C) {}
 203   // No warning, rvalue-reference to the temporary
 204   //for (Bar &x : C) {}
 205   // Binding error
 206   for (Bar x : C) {}
 207   // No warning, non-reference type indicates copy is made
 208
 209   for (const int &&x : C) {}
 210   // No warning, rvalue-reference to the temporary
 211   for (const int &x : C) {}
 212   // expected-warning@-1 {{binds to a temporary value produced by a range}}
 213   // expected-note@-2 {{'int'}}
 214   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 215   for (const int x : C) {}
 216   // No warning, copy made
 217   for (int &&x : C) {}
 218   // No warning, rvalue-reference to the temporary
 219   //for (int &x : C) {}
 220   // Binding error
 221   for (int x : C) {}
 222   // No warning, copy made
 223 }
 224
 225 void test4() {
 226   Container<Bar&> D;
 227
 228   //for (const Bar &&x : D) {}
 229   // Binding error
 230   for (const Bar &x : D) {}
 231   // No warning, this reference is not a temporary
 232   for (const Bar x : D) {}
 233   // expected-warning@-1 {{creates a copy}}
 234   // expected-note@-2 {{'const Bar &'}}
 235   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:18}:"&"
 236   //for (Bar &&x : D) {}
 237   // Binding error
 238   for (Bar &x : D) {}
 239   // No warning
 240   for (Bar x : D) {}
 241   // No warning
 242
 243   for (const int &&x : D) {}
 244   // expected-warning@-1 {{binds to a temporary constructed from}}
 245   // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}}
 246   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:""
 247   for (const int &x : D) {}
 248   // expected-warning@-1 {{binds to a temporary constructed from}}
 249   // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}}
 250   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 251   for (const int x : D) {}
 252   // No warning
 253   for (int &&x : D) {}
 254   // expected-warning@-1 {{binds to a temporary constructed from}}
 255   // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}}
 256   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:""
 257   //for (int &x : D) {}
 258   // Binding error
 259   for (int x : D) {}
 260   // No warning
 261 }
 262
 263 void test5() {
 264   Container<Foo> E;
 265
 266   for (const Bar &&x : E) {}
 267   // No warning, rvalue-reference to the temporary
 268   for (const Bar &x : E) {}
 269   // expected-warning@-1 {{binds to a temporary value produced by a range}}
 270   // expected-note@-2 {{'Bar'}}
 271   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 272   for (const Bar x : E) {}
 273   // No warning, non-reference type indicates copy is made
 274   for (Bar &&x : E) {}
 275   // No warning, rvalue-reference to the temporary
 276   //for (Bar &x : E) {}
 277   // Binding error
 278   for (Bar x : E) {}
 279   // No warning, non-reference type indicates copy is made
 280 }
 281
 282 void test6() {
 283   Container<Foo&> F;
 284
 285   for (const Bar &&x : F) {}
 286   // expected-warning@-1 {{binds to a temporary constructed from}}
 287   // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}}
 288   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:""
 289   for (const Bar &x : F) {}
 290   // expected-warning@-1 {{binds to a temporary constructed from}}
 291   // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}}
 292   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 293   for (const Bar x : F) {}
 294   // No warning.
 295   for (Bar &&x : F) {}
 296   // expected-warning@-1 {{binds to a temporary constructed from}}
 297   // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}}
 298   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:""
 299   //for (Bar &x : F) {}
 300   // Binding error
 301   for (Bar x : F) {}
 302   // No warning
 303 }
 304
 305 void test7() {
 306   double G[2];
 307
 308   //for (const double &&x : G) {}
 309   // Binding error
 310   for (const double &x : G) {}
 311   // No warning
 312   for (const double x : G) {}
 313   // No warning on POD copy
 314   //for (double &&x : G) {}
 315   // Binding error
 316   for (double &x : G) {}
 317   // No warning
 318   for (double x : G) {}
 319   // No warning
 320
 321   for (const int &&x : G) {}
 322   // expected-warning@-1 {{binds to a temporary constructed from}}
 323   // expected-note-re@-2 {{'int'{{.*}}'const double &'}}
 324   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:""
 325   for (const int &x : G) {}
 326   // expected-warning@-1 {{binds to a temporary constructed from}}
 327   // expected-note-re@-2 {{'int'{{.*}}'const double &'}}
 328   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 329   for (const int x : G) {}
 330   // No warning
 331   for (int &&x : G) {}
 332   // expected-warning@-1 {{binds to a temporary constructed from}}
 333   // expected-note-re@-2 {{'int'{{.*}}'const double &'}}
 334   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:""
 335   //for (int &x : G) {}
 336   // Binding error
 337   for (int x : G) {}
 338   // No warning
 339
 340   for (const Bar &&x : G) {}
 341   // expected-warning@-1 {{binds to a temporary constructed from}}
 342   // expected-note-re@-2 {{'Bar'{{.*}}'const double &'}}
 343   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:""
 344   for (const Bar &x : G) {}
 345   // expected-warning@-1 {{binds to a temporary constructed from}}
 346   // expected-note-re@-2 {{'Bar'{{.*}}'const double &'}}
 347   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 348   for (const Bar x : G) {}
 349   // No warning
 350   for (Bar &&x : G) {}
 351   // expected-warning@-1 {{binds to a temporary constructed from}}
 352   // expected-note-re@-2 {{'Bar'{{.*}}'const double &'}}
 353   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:""
 354   //for (Bar &x : G) {}
 355   // Binding error
 356   for (Bar x : G) {}
 357   // No warning
 358 }
 359
 360 void test8() {
 361   Foo H[2];
 362
 363   //for (const Foo &&x : H) {}
 364   // Binding error
 365   for (const Foo &x : H) {}
 366   // No warning
 367   for (const Foo x : H) {}
 368   // No warning on POD copy
 369   //for (Foo &&x : H) {}
 370   // Binding error
 371   for (Foo &x : H) {}
 372   // No warning
 373   for (Foo x : H) {}
 374   // No warning
 375
 376   for (const Bar &&x : H) {}
 377   // expected-warning@-1 {{binds to a temporary constructed from}}
 378   // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}}
 379   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:""
 380   for (const Bar &x : H) {}
 381   // expected-warning@-1 {{binds to a temporary constructed from}}
 382   // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}}
 383   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 384   for (const Bar x : H) {}
 385   // No warning
 386   for (Bar &&x: H) {}
 387   // expected-warning@-1 {{binds to a temporary constructed from}}
 388   // expected-note-re@-2 {{'Bar'{{.*}}'const Foo &'}}
 389   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:""
 390   //for (Bar &x: H) {}
 391   // Binding error
 392   for (Bar x: H) {}
 393   // No warning
 394 }
 395
 396 void test9() {
 397   Bar I[2] = {1,2};
 398
 399   //for (const Bar &&x : I) {}
 400   // Binding error
 401   for (const Bar &x : I) {}
 402   // No warning
 403   for (const Bar x : I) {}
 404   // expected-warning@-1 {{creates a copy}}
 405   // expected-note@-2 {{'const Bar &'}}
 406   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:18}:"&"
 407   //for (Bar &&x : I) {}
 408   // Binding error
 409   for (Bar &x : I) {}
 410   // No warning
 411   for (Bar x : I) {}
 412   // No warning
 413
 414   for (const int &&x : I) {}
 415   // expected-warning@-1 {{binds to a temporary constructed from}}
 416   // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}}
 417   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:""
 418   for (const int &x : I) {}
 419   // expected-warning@-1 {{binds to a temporary constructed from}}
 420   // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}}
 421   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 422   for (const int x : I) {}
 423   // No warning
 424   for (int &&x : I) {}
 425   // expected-warning@-1 {{binds to a temporary constructed from}}
 426   // expected-note-re@-2 {{'int'{{.*}}'const Bar &'}}
 427   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:12-[[@LINE-3]]:14}:""
 428   //for (int &x : I) {}
 429   // Binding error
 430   for (int x : I) {}
 431   // No warning
 432 }
 433
 434 void test10() {
 435   Container<Bar> C;
 436
 437   for (const Bar &x : C) {}
 438   // expected-warning@-1 {{binds to a temporary value produced by a range}}
 439   // expected-note@-2 {{'Bar'}}
 440   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 441
 442   for (const Bar& x : C) {}
 443   // expected-warning@-1 {{binds to a temporary value produced by a range}}
 444   // expected-note@-2 {{'Bar'}}
 445   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:17-[[@LINE-3]]:18}:""
 446
 447   for (const Bar & x : C) {}
 448   // expected-warning@-1 {{binds to a temporary value produced by a range}}
 449   // expected-note@-2 {{'Bar'}}
 450   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:20}:""
 451
 452   for (const Bar&x : C) {}
 453   // expected-warning@-1 {{binds to a temporary value produced by a range}}
 454   // expected-note@-2 {{'Bar'}}
 455   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:17-[[@LINE-3]]:18}:" "
 456 }
 457
 458 template <class T>
 459 void test_template_function() {
 460   // In a template instantiation the diagnostics should not be emitted for
 461   // loops with dependent types.
 462   Container<Bar> C;
 463   for (const Bar &x : C) {}
 464   // expected-warning@-1 {{binds to a temporary value produced by a range}}
 465   // expected-note@-2 {{'Bar'}}
 466   // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:18-[[@LINE-3]]:19}:""
 467
 468   Container<T> Dependent;
 469   for (const T &x : Dependent) {}
 470 }
 471 template void test_template_function<Bar>();
 472
 473 template <class T>
 474 struct test_template_struct {
 475   static void static_member() {
 476     Container<Bar> C;
 477     for (const Bar &x : C) {}
 478     // expected-warning@-1 {{binds to a temporary value produced by a range}}
 479     // expected-note@-2 {{'Bar'}}
 480     // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:20-[[@LINE-3]]:21}:""
 481
 482     Container<T> Dependent;
 483     for (const T &x : Dependent) {}
 484   }
 485
 486   void member() {
 487     Container<Bar> C;
 488     for (const Bar &x : C) {}
 489     // expected-warning@-1 {{binds to a temporary value produced by a range}}
 490     // expected-note@-2 {{'Bar'}}
 491     // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:20-[[@LINE-3]]:21}:""
 492
 493     Container<T> Dependent;
 494     for (const T &x : Dependent) {}
 495   }
 496 };
 497 template struct test_template_struct<Bar>;
 498
 499 struct test_struct_with_templated_member {
 500   void member() {
 501     Container<Bar> C;
 502     for (const Bar &x : C) {}
 503     // expected-warning@-1 {{binds to a temporary value produced by a range}}
 504     // expected-note@-2 {{'Bar'}}
 505     // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:20-[[@LINE-3]]:21}:""
 506   }
 507
 508   template <class T>
 509   void template_member() {
 510     Container<Bar> C;
 511     for (const Bar &x : C) {}
 512     // expected-warning@-1 {{binds to a temporary value produced by a range}}
 513     // expected-note@-2 {{'Bar'}}
 514     // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:20-[[@LINE-3]]:21}:""
 515
 516     Container<T> Dependent;
 517     for (const T &x : Dependent) {}
 518   }
 519 };
 520 template void test_struct_with_templated_member::template_member<Bar>();
 521
 522 #define TEST_MACRO            \
 523   void test_macro() {         \
 524     Container<Bar> C;         \
 525     for (const Bar &x : C) {} \
 526   }
 527
 528 TEST_MACRO