1 //===--- SemaInit.cpp - Semantic Analysis for Initializers ----------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements semantic analysis for initializers. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/Sema/Initialization.h" 15 #include "clang/AST/ASTContext.h" 16 #include "clang/AST/DeclObjC.h" 17 #include "clang/AST/ExprCXX.h" 18 #include "clang/AST/ExprObjC.h" 19 #include "clang/AST/TypeLoc.h" 20 #include "clang/Basic/TargetInfo.h" 21 #include "clang/Sema/Designator.h" 22 #include "clang/Sema/Lookup.h" 23 #include "clang/Sema/SemaInternal.h" 24 #include "llvm/ADT/APInt.h" 25 #include "llvm/ADT/SmallString.h" 26 #include "llvm/Support/ErrorHandling.h" 27 #include "llvm/Support/raw_ostream.h" 28 #include <map> 29 using namespace clang; 30 31 //===----------------------------------------------------------------------===// 32 // Sema Initialization Checking 33 //===----------------------------------------------------------------------===// 34 35 /// \brief Check whether T is compatible with a wide character type (wchar_t, 36 /// char16_t or char32_t). 37 static bool IsWideCharCompatible(QualType T, ASTContext &Context) { 38 if (Context.typesAreCompatible(Context.getWideCharType(), T)) 39 return true; 40 if (Context.getLangOpts().CPlusPlus || Context.getLangOpts().C11) { 41 return Context.typesAreCompatible(Context.Char16Ty, T) || 42 Context.typesAreCompatible(Context.Char32Ty, T); 43 } 44 return false; 45 } 46 47 enum StringInitFailureKind { 48 SIF_None, 49 SIF_NarrowStringIntoWideChar, 50 SIF_WideStringIntoChar, 51 SIF_IncompatWideStringIntoWideChar, 52 SIF_Other 53 }; 54 55 /// \brief Check whether the array of type AT can be initialized by the Init 56 /// expression by means of string initialization. Returns SIF_None if so, 57 /// otherwise returns a StringInitFailureKind that describes why the 58 /// initialization would not work. 59 static StringInitFailureKind IsStringInit(Expr *Init, const ArrayType *AT, 60 ASTContext &Context) { 61 if (!isa<ConstantArrayType>(AT) && !isa<IncompleteArrayType>(AT)) 62 return SIF_Other; 63 64 // See if this is a string literal or @encode. 65 Init = Init->IgnoreParens(); 66 67 // Handle @encode, which is a narrow string. 68 if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType()) 69 return SIF_None; 70 71 // Otherwise we can only handle string literals. 72 StringLiteral *SL = dyn_cast<StringLiteral>(Init); 73 if (!SL) 74 return SIF_Other; 75 76 const QualType ElemTy = 77 Context.getCanonicalType(AT->getElementType()).getUnqualifiedType(); 78 79 switch (SL->getKind()) { 80 case StringLiteral::Ascii: 81 case StringLiteral::UTF8: 82 // char array can be initialized with a narrow string. 83 // Only allow char x[] = "foo"; not char x[] = L"foo"; 84 if (ElemTy->isCharType()) 85 return SIF_None; 86 if (IsWideCharCompatible(ElemTy, Context)) 87 return SIF_NarrowStringIntoWideChar; 88 return SIF_Other; 89 // C99 6.7.8p15 (with correction from DR343), or C11 6.7.9p15: 90 // "An array with element type compatible with a qualified or unqualified 91 // version of wchar_t, char16_t, or char32_t may be initialized by a wide 92 // string literal with the corresponding encoding prefix (L, u, or U, 93 // respectively), optionally enclosed in braces. 94 case StringLiteral::UTF16: 95 if (Context.typesAreCompatible(Context.Char16Ty, ElemTy)) 96 return SIF_None; 97 if (ElemTy->isCharType()) 98 return SIF_WideStringIntoChar; 99 if (IsWideCharCompatible(ElemTy, Context)) 100 return SIF_IncompatWideStringIntoWideChar; 101 return SIF_Other; 102 case StringLiteral::UTF32: 103 if (Context.typesAreCompatible(Context.Char32Ty, ElemTy)) 104 return SIF_None; 105 if (ElemTy->isCharType()) 106 return SIF_WideStringIntoChar; 107 if (IsWideCharCompatible(ElemTy, Context)) 108 return SIF_IncompatWideStringIntoWideChar; 109 return SIF_Other; 110 case StringLiteral::Wide: 111 if (Context.typesAreCompatible(Context.getWideCharType(), ElemTy)) 112 return SIF_None; 113 if (ElemTy->isCharType()) 114 return SIF_WideStringIntoChar; 115 if (IsWideCharCompatible(ElemTy, Context)) 116 return SIF_IncompatWideStringIntoWideChar; 117 return SIF_Other; 118 } 119 120 llvm_unreachable("missed a StringLiteral kind?"); 121 } 122 123 static StringInitFailureKind IsStringInit(Expr *init, QualType declType, 124 ASTContext &Context) { 125 const ArrayType *arrayType = Context.getAsArrayType(declType); 126 if (!arrayType) 127 return SIF_Other; 128 return IsStringInit(init, arrayType, Context); 129 } 130 131 /// Update the type of a string literal, including any surrounding parentheses, 132 /// to match the type of the object which it is initializing. 133 static void updateStringLiteralType(Expr *E, QualType Ty) { 134 while (true) { 135 E->setType(Ty); 136 if (isa<StringLiteral>(E) || isa<ObjCEncodeExpr>(E)) 137 break; 138 else if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) 139 E = PE->getSubExpr(); 140 else if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) 141 E = UO->getSubExpr(); 142 else if (GenericSelectionExpr *GSE = dyn_cast<GenericSelectionExpr>(E)) 143 E = GSE->getResultExpr(); 144 else 145 llvm_unreachable("unexpected expr in string literal init"); 146 } 147 } 148 149 static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT, 150 Sema &S) { 151 // Get the length of the string as parsed. 152 auto *ConstantArrayTy = 153 cast<ConstantArrayType>(Str->getType()->getAsArrayTypeUnsafe()); 154 uint64_t StrLength = ConstantArrayTy->getSize().getZExtValue(); 155 156 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 157 // C99 6.7.8p14. We have an array of character type with unknown size 158 // being initialized to a string literal. 159 llvm::APInt ConstVal(32, StrLength); 160 // Return a new array type (C99 6.7.8p22). 161 DeclT = S.Context.getConstantArrayType(IAT->getElementType(), 162 ConstVal, 163 ArrayType::Normal, 0); 164 updateStringLiteralType(Str, DeclT); 165 return; 166 } 167 168 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 169 170 // We have an array of character type with known size. However, 171 // the size may be smaller or larger than the string we are initializing. 172 // FIXME: Avoid truncation for 64-bit length strings. 173 if (S.getLangOpts().CPlusPlus) { 174 if (StringLiteral *SL = dyn_cast<StringLiteral>(Str->IgnoreParens())) { 175 // For Pascal strings it's OK to strip off the terminating null character, 176 // so the example below is valid: 177 // 178 // unsigned char a[2] = "\pa"; 179 if (SL->isPascal()) 180 StrLength--; 181 } 182 183 // [dcl.init.string]p2 184 if (StrLength > CAT->getSize().getZExtValue()) 185 S.Diag(Str->getLocStart(), 186 diag::err_initializer_string_for_char_array_too_long) 187 << Str->getSourceRange(); 188 } else { 189 // C99 6.7.8p14. 190 if (StrLength-1 > CAT->getSize().getZExtValue()) 191 S.Diag(Str->getLocStart(), 192 diag::ext_initializer_string_for_char_array_too_long) 193 << Str->getSourceRange(); 194 } 195 196 // Set the type to the actual size that we are initializing. If we have 197 // something like: 198 // char x[1] = "foo"; 199 // then this will set the string literal's type to char[1]. 200 updateStringLiteralType(Str, DeclT); 201 } 202 203 //===----------------------------------------------------------------------===// 204 // Semantic checking for initializer lists. 205 //===----------------------------------------------------------------------===// 206 207 /// @brief Semantic checking for initializer lists. 208 /// 209 /// The InitListChecker class contains a set of routines that each 210 /// handle the initialization of a certain kind of entity, e.g., 211 /// arrays, vectors, struct/union types, scalars, etc. The 212 /// InitListChecker itself performs a recursive walk of the subobject 213 /// structure of the type to be initialized, while stepping through 214 /// the initializer list one element at a time. The IList and Index 215 /// parameters to each of the Check* routines contain the active 216 /// (syntactic) initializer list and the index into that initializer 217 /// list that represents the current initializer. Each routine is 218 /// responsible for moving that Index forward as it consumes elements. 219 /// 220 /// Each Check* routine also has a StructuredList/StructuredIndex 221 /// arguments, which contains the current "structured" (semantic) 222 /// initializer list and the index into that initializer list where we 223 /// are copying initializers as we map them over to the semantic 224 /// list. Once we have completed our recursive walk of the subobject 225 /// structure, we will have constructed a full semantic initializer 226 /// list. 227 /// 228 /// C99 designators cause changes in the initializer list traversal, 229 /// because they make the initialization "jump" into a specific 230 /// subobject and then continue the initialization from that 231 /// point. CheckDesignatedInitializer() recursively steps into the 232 /// designated subobject and manages backing out the recursion to 233 /// initialize the subobjects after the one designated. 234 namespace { 235 class InitListChecker { 236 Sema &SemaRef; 237 bool hadError; 238 bool VerifyOnly; // no diagnostics, no structure building 239 llvm::DenseMap<InitListExpr *, InitListExpr *> SyntacticToSemantic; 240 InitListExpr *FullyStructuredList; 241 242 void CheckImplicitInitList(const InitializedEntity &Entity, 243 InitListExpr *ParentIList, QualType T, 244 unsigned &Index, InitListExpr *StructuredList, 245 unsigned &StructuredIndex); 246 void CheckExplicitInitList(const InitializedEntity &Entity, 247 InitListExpr *IList, QualType &T, 248 InitListExpr *StructuredList, 249 bool TopLevelObject = false); 250 void CheckListElementTypes(const InitializedEntity &Entity, 251 InitListExpr *IList, QualType &DeclType, 252 bool SubobjectIsDesignatorContext, 253 unsigned &Index, 254 InitListExpr *StructuredList, 255 unsigned &StructuredIndex, 256 bool TopLevelObject = false); 257 void CheckSubElementType(const InitializedEntity &Entity, 258 InitListExpr *IList, QualType ElemType, 259 unsigned &Index, 260 InitListExpr *StructuredList, 261 unsigned &StructuredIndex); 262 void CheckComplexType(const InitializedEntity &Entity, 263 InitListExpr *IList, QualType DeclType, 264 unsigned &Index, 265 InitListExpr *StructuredList, 266 unsigned &StructuredIndex); 267 void CheckScalarType(const InitializedEntity &Entity, 268 InitListExpr *IList, QualType DeclType, 269 unsigned &Index, 270 InitListExpr *StructuredList, 271 unsigned &StructuredIndex); 272 void CheckReferenceType(const InitializedEntity &Entity, 273 InitListExpr *IList, QualType DeclType, 274 unsigned &Index, 275 InitListExpr *StructuredList, 276 unsigned &StructuredIndex); 277 void CheckVectorType(const InitializedEntity &Entity, 278 InitListExpr *IList, QualType DeclType, unsigned &Index, 279 InitListExpr *StructuredList, 280 unsigned &StructuredIndex); 281 void CheckStructUnionTypes(const InitializedEntity &Entity, 282 InitListExpr *IList, QualType DeclType, 283 RecordDecl::field_iterator Field, 284 bool SubobjectIsDesignatorContext, unsigned &Index, 285 InitListExpr *StructuredList, 286 unsigned &StructuredIndex, 287 bool TopLevelObject = false); 288 void CheckArrayType(const InitializedEntity &Entity, 289 InitListExpr *IList, QualType &DeclType, 290 llvm::APSInt elementIndex, 291 bool SubobjectIsDesignatorContext, unsigned &Index, 292 InitListExpr *StructuredList, 293 unsigned &StructuredIndex); 294 bool CheckDesignatedInitializer(const InitializedEntity &Entity, 295 InitListExpr *IList, DesignatedInitExpr *DIE, 296 unsigned DesigIdx, 297 QualType &CurrentObjectType, 298 RecordDecl::field_iterator *NextField, 299 llvm::APSInt *NextElementIndex, 300 unsigned &Index, 301 InitListExpr *StructuredList, 302 unsigned &StructuredIndex, 303 bool FinishSubobjectInit, 304 bool TopLevelObject); 305 InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index, 306 QualType CurrentObjectType, 307 InitListExpr *StructuredList, 308 unsigned StructuredIndex, 309 SourceRange InitRange); 310 void UpdateStructuredListElement(InitListExpr *StructuredList, 311 unsigned &StructuredIndex, 312 Expr *expr); 313 int numArrayElements(QualType DeclType); 314 int numStructUnionElements(QualType DeclType); 315 316 static ExprResult PerformEmptyInit(Sema &SemaRef, 317 SourceLocation Loc, 318 const InitializedEntity &Entity, 319 bool VerifyOnly); 320 void FillInEmptyInitForField(unsigned Init, FieldDecl *Field, 321 const InitializedEntity &ParentEntity, 322 InitListExpr *ILE, bool &RequiresSecondPass); 323 void FillInEmptyInitializations(const InitializedEntity &Entity, 324 InitListExpr *ILE, bool &RequiresSecondPass); 325 bool CheckFlexibleArrayInit(const InitializedEntity &Entity, 326 Expr *InitExpr, FieldDecl *Field, 327 bool TopLevelObject); 328 void CheckEmptyInitializable(const InitializedEntity &Entity, 329 SourceLocation Loc); 330 331 public: 332 InitListChecker(Sema &S, const InitializedEntity &Entity, 333 InitListExpr *IL, QualType &T, bool VerifyOnly); 334 bool HadError() { return hadError; } 335 336 // @brief Retrieves the fully-structured initializer list used for 337 // semantic analysis and code generation. 338 InitListExpr *getFullyStructuredList() const { return FullyStructuredList; } 339 }; 340 } // end anonymous namespace 341 342 ExprResult InitListChecker::PerformEmptyInit(Sema &SemaRef, 343 SourceLocation Loc, 344 const InitializedEntity &Entity, 345 bool VerifyOnly) { 346 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, 347 true); 348 MultiExprArg SubInit; 349 Expr *InitExpr; 350 InitListExpr DummyInitList(SemaRef.Context, Loc, None, Loc); 351 352 // C++ [dcl.init.aggr]p7: 353 // If there are fewer initializer-clauses in the list than there are 354 // members in the aggregate, then each member not explicitly initialized 355 // ... 356 bool EmptyInitList = SemaRef.getLangOpts().CPlusPlus11 && 357 Entity.getType()->getBaseElementTypeUnsafe()->isRecordType(); 358 if (EmptyInitList) { 359 // C++1y / DR1070: 360 // shall be initialized [...] from an empty initializer list. 361 // 362 // We apply the resolution of this DR to C++11 but not C++98, since C++98 363 // does not have useful semantics for initialization from an init list. 364 // We treat this as copy-initialization, because aggregate initialization 365 // always performs copy-initialization on its elements. 366 // 367 // Only do this if we're initializing a class type, to avoid filling in 368 // the initializer list where possible. 369 InitExpr = VerifyOnly ? &DummyInitList : new (SemaRef.Context) 370 InitListExpr(SemaRef.Context, Loc, None, Loc); 371 InitExpr->setType(SemaRef.Context.VoidTy); 372 SubInit = InitExpr; 373 Kind = InitializationKind::CreateCopy(Loc, Loc); 374 } else { 375 // C++03: 376 // shall be value-initialized. 377 } 378 379 InitializationSequence InitSeq(SemaRef, Entity, Kind, SubInit); 380 // libstdc++4.6 marks the vector default constructor as explicit in 381 // _GLIBCXX_DEBUG mode, so recover using the C++03 logic in that case. 382 // stlport does so too. Look for std::__debug for libstdc++, and for 383 // std:: for stlport. This is effectively a compiler-side implementation of 384 // LWG2193. 385 if (!InitSeq && EmptyInitList && InitSeq.getFailureKind() == 386 InitializationSequence::FK_ExplicitConstructor) { 387 OverloadCandidateSet::iterator Best; 388 OverloadingResult O = 389 InitSeq.getFailedCandidateSet() 390 .BestViableFunction(SemaRef, Kind.getLocation(), Best); 391 (void)O; 392 assert(O == OR_Success && "Inconsistent overload resolution"); 393 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function); 394 CXXRecordDecl *R = CtorDecl->getParent(); 395 396 if (CtorDecl->getMinRequiredArguments() == 0 && 397 CtorDecl->isExplicit() && R->getDeclName() && 398 SemaRef.SourceMgr.isInSystemHeader(CtorDecl->getLocation())) { 399 400 401 bool IsInStd = false; 402 for (NamespaceDecl *ND = dyn_cast<NamespaceDecl>(R->getDeclContext()); 403 ND && !IsInStd; ND = dyn_cast<NamespaceDecl>(ND->getParent())) { 404 if (SemaRef.getStdNamespace()->InEnclosingNamespaceSetOf(ND)) 405 IsInStd = true; 406 } 407 408 if (IsInStd && llvm::StringSwitch<bool>(R->getName()) 409 .Cases("basic_string", "deque", "forward_list", true) 410 .Cases("list", "map", "multimap", "multiset", true) 411 .Cases("priority_queue", "queue", "set", "stack", true) 412 .Cases("unordered_map", "unordered_set", "vector", true) 413 .Default(false)) { 414 InitSeq.InitializeFrom( 415 SemaRef, Entity, 416 InitializationKind::CreateValue(Loc, Loc, Loc, true), 417 MultiExprArg(), /*TopLevelOfInitList=*/false); 418 // Emit a warning for this. System header warnings aren't shown 419 // by default, but people working on system headers should see it. 420 if (!VerifyOnly) { 421 SemaRef.Diag(CtorDecl->getLocation(), 422 diag::warn_invalid_initializer_from_system_header); 423 SemaRef.Diag(Entity.getDecl()->getLocation(), 424 diag::note_used_in_initialization_here); 425 } 426 } 427 } 428 } 429 if (!InitSeq) { 430 if (!VerifyOnly) { 431 InitSeq.Diagnose(SemaRef, Entity, Kind, SubInit); 432 if (Entity.getKind() == InitializedEntity::EK_Member) 433 SemaRef.Diag(Entity.getDecl()->getLocation(), 434 diag::note_in_omitted_aggregate_initializer) 435 << /*field*/1 << Entity.getDecl(); 436 else if (Entity.getKind() == InitializedEntity::EK_ArrayElement) 437 SemaRef.Diag(Loc, diag::note_in_omitted_aggregate_initializer) 438 << /*array element*/0 << Entity.getElementIndex(); 439 } 440 return ExprError(); 441 } 442 443 return VerifyOnly ? ExprResult(static_cast<Expr *>(nullptr)) 444 : InitSeq.Perform(SemaRef, Entity, Kind, SubInit); 445 } 446 447 void InitListChecker::CheckEmptyInitializable(const InitializedEntity &Entity, 448 SourceLocation Loc) { 449 assert(VerifyOnly && 450 "CheckEmptyInitializable is only inteded for verification mode."); 451 if (PerformEmptyInit(SemaRef, Loc, Entity, /*VerifyOnly*/true).isInvalid()) 452 hadError = true; 453 } 454 455 void InitListChecker::FillInEmptyInitForField(unsigned Init, FieldDecl *Field, 456 const InitializedEntity &ParentEntity, 457 InitListExpr *ILE, 458 bool &RequiresSecondPass) { 459 SourceLocation Loc = ILE->getLocEnd(); 460 unsigned NumInits = ILE->getNumInits(); 461 InitializedEntity MemberEntity 462 = InitializedEntity::InitializeMember(Field, &ParentEntity); 463 if (Init >= NumInits || !ILE->getInit(Init)) { 464 // C++1y [dcl.init.aggr]p7: 465 // If there are fewer initializer-clauses in the list than there are 466 // members in the aggregate, then each member not explicitly initialized 467 // shall be initialized from its brace-or-equal-initializer [...] 468 if (Field->hasInClassInitializer()) { 469 ExprResult DIE = SemaRef.BuildCXXDefaultInitExpr(Loc, Field); 470 if (DIE.isInvalid()) { 471 hadError = true; 472 return; 473 } 474 if (Init < NumInits) 475 ILE->setInit(Init, DIE.get()); 476 else { 477 ILE->updateInit(SemaRef.Context, Init, DIE.get()); 478 RequiresSecondPass = true; 479 } 480 return; 481 } 482 483 if (Field->getType()->isReferenceType()) { 484 // C++ [dcl.init.aggr]p9: 485 // If an incomplete or empty initializer-list leaves a 486 // member of reference type uninitialized, the program is 487 // ill-formed. 488 SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized) 489 << Field->getType() 490 << ILE->getSyntacticForm()->getSourceRange(); 491 SemaRef.Diag(Field->getLocation(), 492 diag::note_uninit_reference_member); 493 hadError = true; 494 return; 495 } 496 497 ExprResult MemberInit = PerformEmptyInit(SemaRef, Loc, MemberEntity, 498 /*VerifyOnly*/false); 499 if (MemberInit.isInvalid()) { 500 hadError = true; 501 return; 502 } 503 504 if (hadError) { 505 // Do nothing 506 } else if (Init < NumInits) { 507 ILE->setInit(Init, MemberInit.getAs<Expr>()); 508 } else if (!isa<ImplicitValueInitExpr>(MemberInit.get())) { 509 // Empty initialization requires a constructor call, so 510 // extend the initializer list to include the constructor 511 // call and make a note that we'll need to take another pass 512 // through the initializer list. 513 ILE->updateInit(SemaRef.Context, Init, MemberInit.getAs<Expr>()); 514 RequiresSecondPass = true; 515 } 516 } else if (InitListExpr *InnerILE 517 = dyn_cast<InitListExpr>(ILE->getInit(Init))) 518 FillInEmptyInitializations(MemberEntity, InnerILE, 519 RequiresSecondPass); 520 } 521 522 /// Recursively replaces NULL values within the given initializer list 523 /// with expressions that perform value-initialization of the 524 /// appropriate type. 525 void 526 InitListChecker::FillInEmptyInitializations(const InitializedEntity &Entity, 527 InitListExpr *ILE, 528 bool &RequiresSecondPass) { 529 assert((ILE->getType() != SemaRef.Context.VoidTy) && 530 "Should not have void type"); 531 532 if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) { 533 const RecordDecl *RDecl = RType->getDecl(); 534 if (RDecl->isUnion() && ILE->getInitializedFieldInUnion()) 535 FillInEmptyInitForField(0, ILE->getInitializedFieldInUnion(), 536 Entity, ILE, RequiresSecondPass); 537 else if (RDecl->isUnion() && isa<CXXRecordDecl>(RDecl) && 538 cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) { 539 for (auto *Field : RDecl->fields()) { 540 if (Field->hasInClassInitializer()) { 541 FillInEmptyInitForField(0, Field, Entity, ILE, RequiresSecondPass); 542 break; 543 } 544 } 545 } else { 546 unsigned Init = 0; 547 for (auto *Field : RDecl->fields()) { 548 if (Field->isUnnamedBitfield()) 549 continue; 550 551 if (hadError) 552 return; 553 554 FillInEmptyInitForField(Init, Field, Entity, ILE, RequiresSecondPass); 555 if (hadError) 556 return; 557 558 ++Init; 559 560 // Only look at the first initialization of a union. 561 if (RDecl->isUnion()) 562 break; 563 } 564 } 565 566 return; 567 } 568 569 QualType ElementType; 570 571 InitializedEntity ElementEntity = Entity; 572 unsigned NumInits = ILE->getNumInits(); 573 unsigned NumElements = NumInits; 574 if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) { 575 ElementType = AType->getElementType(); 576 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) 577 NumElements = CAType->getSize().getZExtValue(); 578 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context, 579 0, Entity); 580 } else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) { 581 ElementType = VType->getElementType(); 582 NumElements = VType->getNumElements(); 583 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context, 584 0, Entity); 585 } else 586 ElementType = ILE->getType(); 587 588 for (unsigned Init = 0; Init != NumElements; ++Init) { 589 if (hadError) 590 return; 591 592 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement || 593 ElementEntity.getKind() == InitializedEntity::EK_VectorElement) 594 ElementEntity.setElementIndex(Init); 595 596 Expr *InitExpr = (Init < NumInits ? ILE->getInit(Init) : nullptr); 597 if (!InitExpr && !ILE->hasArrayFiller()) { 598 ExprResult ElementInit = PerformEmptyInit(SemaRef, ILE->getLocEnd(), 599 ElementEntity, 600 /*VerifyOnly*/false); 601 if (ElementInit.isInvalid()) { 602 hadError = true; 603 return; 604 } 605 606 if (hadError) { 607 // Do nothing 608 } else if (Init < NumInits) { 609 // For arrays, just set the expression used for value-initialization 610 // of the "holes" in the array. 611 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) 612 ILE->setArrayFiller(ElementInit.getAs<Expr>()); 613 else 614 ILE->setInit(Init, ElementInit.getAs<Expr>()); 615 } else { 616 // For arrays, just set the expression used for value-initialization 617 // of the rest of elements and exit. 618 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) { 619 ILE->setArrayFiller(ElementInit.getAs<Expr>()); 620 return; 621 } 622 623 if (!isa<ImplicitValueInitExpr>(ElementInit.get())) { 624 // Empty initialization requires a constructor call, so 625 // extend the initializer list to include the constructor 626 // call and make a note that we'll need to take another pass 627 // through the initializer list. 628 ILE->updateInit(SemaRef.Context, Init, ElementInit.getAs<Expr>()); 629 RequiresSecondPass = true; 630 } 631 } 632 } else if (InitListExpr *InnerILE 633 = dyn_cast_or_null<InitListExpr>(InitExpr)) 634 FillInEmptyInitializations(ElementEntity, InnerILE, RequiresSecondPass); 635 } 636 } 637 638 639 InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity, 640 InitListExpr *IL, QualType &T, 641 bool VerifyOnly) 642 : SemaRef(S), VerifyOnly(VerifyOnly) { 643 // FIXME: Check that IL isn't already the semantic form of some other 644 // InitListExpr. If it is, we'd create a broken AST. 645 646 hadError = false; 647 648 FullyStructuredList = 649 getStructuredSubobjectInit(IL, 0, T, nullptr, 0, IL->getSourceRange()); 650 CheckExplicitInitList(Entity, IL, T, FullyStructuredList, 651 /*TopLevelObject=*/true); 652 653 if (!hadError && !VerifyOnly) { 654 bool RequiresSecondPass = false; 655 FillInEmptyInitializations(Entity, FullyStructuredList, RequiresSecondPass); 656 if (RequiresSecondPass && !hadError) 657 FillInEmptyInitializations(Entity, FullyStructuredList, 658 RequiresSecondPass); 659 } 660 } 661 662 int InitListChecker::numArrayElements(QualType DeclType) { 663 // FIXME: use a proper constant 664 int maxElements = 0x7FFFFFFF; 665 if (const ConstantArrayType *CAT = 666 SemaRef.Context.getAsConstantArrayType(DeclType)) { 667 maxElements = static_cast<int>(CAT->getSize().getZExtValue()); 668 } 669 return maxElements; 670 } 671 672 int InitListChecker::numStructUnionElements(QualType DeclType) { 673 RecordDecl *structDecl = DeclType->getAs<RecordType>()->getDecl(); 674 int InitializableMembers = 0; 675 for (const auto *Field : structDecl->fields()) 676 if (!Field->isUnnamedBitfield()) 677 ++InitializableMembers; 678 679 if (structDecl->isUnion()) 680 return std::min(InitializableMembers, 1); 681 return InitializableMembers - structDecl->hasFlexibleArrayMember(); 682 } 683 684 /// Check whether the range of the initializer \p ParentIList from element 685 /// \p Index onwards can be used to initialize an object of type \p T. Update 686 /// \p Index to indicate how many elements of the list were consumed. 687 /// 688 /// This also fills in \p StructuredList, from element \p StructuredIndex 689 /// onwards, with the fully-braced, desugared form of the initialization. 690 void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity, 691 InitListExpr *ParentIList, 692 QualType T, unsigned &Index, 693 InitListExpr *StructuredList, 694 unsigned &StructuredIndex) { 695 int maxElements = 0; 696 697 if (T->isArrayType()) 698 maxElements = numArrayElements(T); 699 else if (T->isRecordType()) 700 maxElements = numStructUnionElements(T); 701 else if (T->isVectorType()) 702 maxElements = T->getAs<VectorType>()->getNumElements(); 703 else 704 llvm_unreachable("CheckImplicitInitList(): Illegal type"); 705 706 if (maxElements == 0) { 707 if (!VerifyOnly) 708 SemaRef.Diag(ParentIList->getInit(Index)->getLocStart(), 709 diag::err_implicit_empty_initializer); 710 ++Index; 711 hadError = true; 712 return; 713 } 714 715 // Build a structured initializer list corresponding to this subobject. 716 InitListExpr *StructuredSubobjectInitList 717 = getStructuredSubobjectInit(ParentIList, Index, T, StructuredList, 718 StructuredIndex, 719 SourceRange(ParentIList->getInit(Index)->getLocStart(), 720 ParentIList->getSourceRange().getEnd())); 721 unsigned StructuredSubobjectInitIndex = 0; 722 723 // Check the element types and build the structural subobject. 724 unsigned StartIndex = Index; 725 CheckListElementTypes(Entity, ParentIList, T, 726 /*SubobjectIsDesignatorContext=*/false, Index, 727 StructuredSubobjectInitList, 728 StructuredSubobjectInitIndex); 729 730 if (!VerifyOnly) { 731 StructuredSubobjectInitList->setType(T); 732 733 unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1); 734 // Update the structured sub-object initializer so that it's ending 735 // range corresponds with the end of the last initializer it used. 736 if (EndIndex < ParentIList->getNumInits()) { 737 SourceLocation EndLoc 738 = ParentIList->getInit(EndIndex)->getSourceRange().getEnd(); 739 StructuredSubobjectInitList->setRBraceLoc(EndLoc); 740 } 741 742 // Complain about missing braces. 743 if (T->isArrayType() || T->isRecordType()) { 744 SemaRef.Diag(StructuredSubobjectInitList->getLocStart(), 745 diag::warn_missing_braces) 746 << StructuredSubobjectInitList->getSourceRange() 747 << FixItHint::CreateInsertion( 748 StructuredSubobjectInitList->getLocStart(), "{") 749 << FixItHint::CreateInsertion( 750 SemaRef.getLocForEndOfToken( 751 StructuredSubobjectInitList->getLocEnd()), 752 "}"); 753 } 754 } 755 } 756 757 /// Warn that \p Entity was of scalar type and was initialized by a 758 /// single-element braced initializer list. 759 static void warnBracedScalarInit(Sema &S, const InitializedEntity &Entity, 760 SourceRange Braces) { 761 // Don't warn during template instantiation. If the initialization was 762 // non-dependent, we warned during the initial parse; otherwise, the 763 // type might not be scalar in some uses of the template. 764 if (!S.ActiveTemplateInstantiations.empty()) 765 return; 766 767 unsigned DiagID = 0; 768 769 switch (Entity.getKind()) { 770 case InitializedEntity::EK_VectorElement: 771 case InitializedEntity::EK_ComplexElement: 772 case InitializedEntity::EK_ArrayElement: 773 case InitializedEntity::EK_Parameter: 774 case InitializedEntity::EK_Parameter_CF_Audited: 775 case InitializedEntity::EK_Result: 776 // Extra braces here are suspicious. 777 DiagID = diag::warn_braces_around_scalar_init; 778 break; 779 780 case InitializedEntity::EK_Member: 781 // Warn on aggregate initialization but not on ctor init list or 782 // default member initializer. 783 if (Entity.getParent()) 784 DiagID = diag::warn_braces_around_scalar_init; 785 break; 786 787 case InitializedEntity::EK_Variable: 788 case InitializedEntity::EK_LambdaCapture: 789 // No warning, might be direct-list-initialization. 790 // FIXME: Should we warn for copy-list-initialization in these cases? 791 break; 792 793 case InitializedEntity::EK_New: 794 case InitializedEntity::EK_Temporary: 795 case InitializedEntity::EK_CompoundLiteralInit: 796 // No warning, braces are part of the syntax of the underlying construct. 797 break; 798 799 case InitializedEntity::EK_RelatedResult: 800 // No warning, we already warned when initializing the result. 801 break; 802 803 case InitializedEntity::EK_Exception: 804 case InitializedEntity::EK_Base: 805 case InitializedEntity::EK_Delegating: 806 case InitializedEntity::EK_BlockElement: 807 llvm_unreachable("unexpected braced scalar init"); 808 } 809 810 if (DiagID) { 811 S.Diag(Braces.getBegin(), DiagID) 812 << Braces 813 << FixItHint::CreateRemoval(Braces.getBegin()) 814 << FixItHint::CreateRemoval(Braces.getEnd()); 815 } 816 } 817 818 819 /// Check whether the initializer \p IList (that was written with explicit 820 /// braces) can be used to initialize an object of type \p T. 821 /// 822 /// This also fills in \p StructuredList with the fully-braced, desugared 823 /// form of the initialization. 824 void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity, 825 InitListExpr *IList, QualType &T, 826 InitListExpr *StructuredList, 827 bool TopLevelObject) { 828 if (!VerifyOnly) { 829 SyntacticToSemantic[IList] = StructuredList; 830 StructuredList->setSyntacticForm(IList); 831 } 832 833 unsigned Index = 0, StructuredIndex = 0; 834 CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true, 835 Index, StructuredList, StructuredIndex, TopLevelObject); 836 if (!VerifyOnly) { 837 QualType ExprTy = T; 838 if (!ExprTy->isArrayType()) 839 ExprTy = ExprTy.getNonLValueExprType(SemaRef.Context); 840 IList->setType(ExprTy); 841 StructuredList->setType(ExprTy); 842 } 843 if (hadError) 844 return; 845 846 if (Index < IList->getNumInits()) { 847 // We have leftover initializers 848 if (VerifyOnly) { 849 if (SemaRef.getLangOpts().CPlusPlus || 850 (SemaRef.getLangOpts().OpenCL && 851 IList->getType()->isVectorType())) { 852 hadError = true; 853 } 854 return; 855 } 856 857 if (StructuredIndex == 1 && 858 IsStringInit(StructuredList->getInit(0), T, SemaRef.Context) == 859 SIF_None) { 860 unsigned DK = diag::ext_excess_initializers_in_char_array_initializer; 861 if (SemaRef.getLangOpts().CPlusPlus) { 862 DK = diag::err_excess_initializers_in_char_array_initializer; 863 hadError = true; 864 } 865 // Special-case 866 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK) 867 << IList->getInit(Index)->getSourceRange(); 868 } else if (!T->isIncompleteType()) { 869 // Don't complain for incomplete types, since we'll get an error 870 // elsewhere 871 QualType CurrentObjectType = StructuredList->getType(); 872 int initKind = 873 CurrentObjectType->isArrayType()? 0 : 874 CurrentObjectType->isVectorType()? 1 : 875 CurrentObjectType->isScalarType()? 2 : 876 CurrentObjectType->isUnionType()? 3 : 877 4; 878 879 unsigned DK = diag::ext_excess_initializers; 880 if (SemaRef.getLangOpts().CPlusPlus) { 881 DK = diag::err_excess_initializers; 882 hadError = true; 883 } 884 if (SemaRef.getLangOpts().OpenCL && initKind == 1) { 885 DK = diag::err_excess_initializers; 886 hadError = true; 887 } 888 889 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK) 890 << initKind << IList->getInit(Index)->getSourceRange(); 891 } 892 } 893 894 if (!VerifyOnly && T->isScalarType() && 895 IList->getNumInits() == 1 && !isa<InitListExpr>(IList->getInit(0))) 896 warnBracedScalarInit(SemaRef, Entity, IList->getSourceRange()); 897 } 898 899 void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity, 900 InitListExpr *IList, 901 QualType &DeclType, 902 bool SubobjectIsDesignatorContext, 903 unsigned &Index, 904 InitListExpr *StructuredList, 905 unsigned &StructuredIndex, 906 bool TopLevelObject) { 907 if (DeclType->isAnyComplexType() && SubobjectIsDesignatorContext) { 908 // Explicitly braced initializer for complex type can be real+imaginary 909 // parts. 910 CheckComplexType(Entity, IList, DeclType, Index, 911 StructuredList, StructuredIndex); 912 } else if (DeclType->isScalarType()) { 913 CheckScalarType(Entity, IList, DeclType, Index, 914 StructuredList, StructuredIndex); 915 } else if (DeclType->isVectorType()) { 916 CheckVectorType(Entity, IList, DeclType, Index, 917 StructuredList, StructuredIndex); 918 } else if (DeclType->isRecordType()) { 919 assert(DeclType->isAggregateType() && 920 "non-aggregate records should be handed in CheckSubElementType"); 921 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 922 CheckStructUnionTypes(Entity, IList, DeclType, RD->field_begin(), 923 SubobjectIsDesignatorContext, Index, 924 StructuredList, StructuredIndex, 925 TopLevelObject); 926 } else if (DeclType->isArrayType()) { 927 llvm::APSInt Zero( 928 SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()), 929 false); 930 CheckArrayType(Entity, IList, DeclType, Zero, 931 SubobjectIsDesignatorContext, Index, 932 StructuredList, StructuredIndex); 933 } else if (DeclType->isVoidType() || DeclType->isFunctionType()) { 934 // This type is invalid, issue a diagnostic. 935 ++Index; 936 if (!VerifyOnly) 937 SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type) 938 << DeclType; 939 hadError = true; 940 } else if (DeclType->isReferenceType()) { 941 CheckReferenceType(Entity, IList, DeclType, Index, 942 StructuredList, StructuredIndex); 943 } else if (DeclType->isObjCObjectType()) { 944 if (!VerifyOnly) 945 SemaRef.Diag(IList->getLocStart(), diag::err_init_objc_class) 946 << DeclType; 947 hadError = true; 948 } else { 949 if (!VerifyOnly) 950 SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type) 951 << DeclType; 952 hadError = true; 953 } 954 } 955 956 void InitListChecker::CheckSubElementType(const InitializedEntity &Entity, 957 InitListExpr *IList, 958 QualType ElemType, 959 unsigned &Index, 960 InitListExpr *StructuredList, 961 unsigned &StructuredIndex) { 962 Expr *expr = IList->getInit(Index); 963 964 if (ElemType->isReferenceType()) 965 return CheckReferenceType(Entity, IList, ElemType, Index, 966 StructuredList, StructuredIndex); 967 968 if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) { 969 if (!SemaRef.getLangOpts().CPlusPlus) { 970 InitListExpr *InnerStructuredList 971 = getStructuredSubobjectInit(IList, Index, ElemType, 972 StructuredList, StructuredIndex, 973 SubInitList->getSourceRange()); 974 CheckExplicitInitList(Entity, SubInitList, ElemType, 975 InnerStructuredList); 976 ++StructuredIndex; 977 ++Index; 978 return; 979 } 980 // C++ initialization is handled later. 981 } else if (isa<ImplicitValueInitExpr>(expr)) { 982 // This happens during template instantiation when we see an InitListExpr 983 // that we've already checked once. 984 assert(SemaRef.Context.hasSameType(expr->getType(), ElemType) && 985 "found implicit initialization for the wrong type"); 986 if (!VerifyOnly) 987 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 988 ++Index; 989 return; 990 } 991 992 if (SemaRef.getLangOpts().CPlusPlus) { 993 // C++ [dcl.init.aggr]p2: 994 // Each member is copy-initialized from the corresponding 995 // initializer-clause. 996 997 // FIXME: Better EqualLoc? 998 InitializationKind Kind = 999 InitializationKind::CreateCopy(expr->getLocStart(), SourceLocation()); 1000 InitializationSequence Seq(SemaRef, Entity, Kind, expr, 1001 /*TopLevelOfInitList*/ true); 1002 1003 // C++14 [dcl.init.aggr]p13: 1004 // If the assignment-expression can initialize a member, the member is 1005 // initialized. Otherwise [...] brace elision is assumed 1006 // 1007 // Brace elision is never performed if the element is not an 1008 // assignment-expression. 1009 if (Seq || isa<InitListExpr>(expr)) { 1010 if (!VerifyOnly) { 1011 ExprResult Result = 1012 Seq.Perform(SemaRef, Entity, Kind, expr); 1013 if (Result.isInvalid()) 1014 hadError = true; 1015 1016 UpdateStructuredListElement(StructuredList, StructuredIndex, 1017 Result.getAs<Expr>()); 1018 } else if (!Seq) 1019 hadError = true; 1020 ++Index; 1021 return; 1022 } 1023 1024 // Fall through for subaggregate initialization 1025 } else if (ElemType->isScalarType() || ElemType->isAtomicType()) { 1026 // FIXME: Need to handle atomic aggregate types with implicit init lists. 1027 return CheckScalarType(Entity, IList, ElemType, Index, 1028 StructuredList, StructuredIndex); 1029 } else if (const ArrayType *arrayType = 1030 SemaRef.Context.getAsArrayType(ElemType)) { 1031 // arrayType can be incomplete if we're initializing a flexible 1032 // array member. There's nothing we can do with the completed 1033 // type here, though. 1034 1035 if (IsStringInit(expr, arrayType, SemaRef.Context) == SIF_None) { 1036 if (!VerifyOnly) { 1037 CheckStringInit(expr, ElemType, arrayType, SemaRef); 1038 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 1039 } 1040 ++Index; 1041 return; 1042 } 1043 1044 // Fall through for subaggregate initialization. 1045 1046 } else { 1047 assert((ElemType->isRecordType() || ElemType->isVectorType()) && 1048 "Unexpected type"); 1049 1050 // C99 6.7.8p13: 1051 // 1052 // The initializer for a structure or union object that has 1053 // automatic storage duration shall be either an initializer 1054 // list as described below, or a single expression that has 1055 // compatible structure or union type. In the latter case, the 1056 // initial value of the object, including unnamed members, is 1057 // that of the expression. 1058 ExprResult ExprRes = expr; 1059 if (SemaRef.CheckSingleAssignmentConstraints( 1060 ElemType, ExprRes, !VerifyOnly) != Sema::Incompatible) { 1061 if (ExprRes.isInvalid()) 1062 hadError = true; 1063 else { 1064 ExprRes = SemaRef.DefaultFunctionArrayLvalueConversion(ExprRes.get()); 1065 if (ExprRes.isInvalid()) 1066 hadError = true; 1067 } 1068 UpdateStructuredListElement(StructuredList, StructuredIndex, 1069 ExprRes.getAs<Expr>()); 1070 ++Index; 1071 return; 1072 } 1073 ExprRes.get(); 1074 // Fall through for subaggregate initialization 1075 } 1076 1077 // C++ [dcl.init.aggr]p12: 1078 // 1079 // [...] Otherwise, if the member is itself a non-empty 1080 // subaggregate, brace elision is assumed and the initializer is 1081 // considered for the initialization of the first member of 1082 // the subaggregate. 1083 if (!SemaRef.getLangOpts().OpenCL && 1084 (ElemType->isAggregateType() || ElemType->isVectorType())) { 1085 CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList, 1086 StructuredIndex); 1087 ++StructuredIndex; 1088 } else { 1089 if (!VerifyOnly) { 1090 // We cannot initialize this element, so let 1091 // PerformCopyInitialization produce the appropriate diagnostic. 1092 SemaRef.PerformCopyInitialization(Entity, SourceLocation(), expr, 1093 /*TopLevelOfInitList=*/true); 1094 } 1095 hadError = true; 1096 ++Index; 1097 ++StructuredIndex; 1098 } 1099 } 1100 1101 void InitListChecker::CheckComplexType(const InitializedEntity &Entity, 1102 InitListExpr *IList, QualType DeclType, 1103 unsigned &Index, 1104 InitListExpr *StructuredList, 1105 unsigned &StructuredIndex) { 1106 assert(Index == 0 && "Index in explicit init list must be zero"); 1107 1108 // As an extension, clang supports complex initializers, which initialize 1109 // a complex number component-wise. When an explicit initializer list for 1110 // a complex number contains two two initializers, this extension kicks in: 1111 // it exepcts the initializer list to contain two elements convertible to 1112 // the element type of the complex type. The first element initializes 1113 // the real part, and the second element intitializes the imaginary part. 1114 1115 if (IList->getNumInits() != 2) 1116 return CheckScalarType(Entity, IList, DeclType, Index, StructuredList, 1117 StructuredIndex); 1118 1119 // This is an extension in C. (The builtin _Complex type does not exist 1120 // in the C++ standard.) 1121 if (!SemaRef.getLangOpts().CPlusPlus && !VerifyOnly) 1122 SemaRef.Diag(IList->getLocStart(), diag::ext_complex_component_init) 1123 << IList->getSourceRange(); 1124 1125 // Initialize the complex number. 1126 QualType elementType = DeclType->getAs<ComplexType>()->getElementType(); 1127 InitializedEntity ElementEntity = 1128 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 1129 1130 for (unsigned i = 0; i < 2; ++i) { 1131 ElementEntity.setElementIndex(Index); 1132 CheckSubElementType(ElementEntity, IList, elementType, Index, 1133 StructuredList, StructuredIndex); 1134 } 1135 } 1136 1137 1138 void InitListChecker::CheckScalarType(const InitializedEntity &Entity, 1139 InitListExpr *IList, QualType DeclType, 1140 unsigned &Index, 1141 InitListExpr *StructuredList, 1142 unsigned &StructuredIndex) { 1143 if (Index >= IList->getNumInits()) { 1144 if (!VerifyOnly) 1145 SemaRef.Diag(IList->getLocStart(), 1146 SemaRef.getLangOpts().CPlusPlus11 ? 1147 diag::warn_cxx98_compat_empty_scalar_initializer : 1148 diag::err_empty_scalar_initializer) 1149 << IList->getSourceRange(); 1150 hadError = !SemaRef.getLangOpts().CPlusPlus11; 1151 ++Index; 1152 ++StructuredIndex; 1153 return; 1154 } 1155 1156 Expr *expr = IList->getInit(Index); 1157 if (InitListExpr *SubIList = dyn_cast<InitListExpr>(expr)) { 1158 // FIXME: This is invalid, and accepting it causes overload resolution 1159 // to pick the wrong overload in some corner cases. 1160 if (!VerifyOnly) 1161 SemaRef.Diag(SubIList->getLocStart(), 1162 diag::ext_many_braces_around_scalar_init) 1163 << SubIList->getSourceRange(); 1164 1165 CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList, 1166 StructuredIndex); 1167 return; 1168 } else if (isa<DesignatedInitExpr>(expr)) { 1169 if (!VerifyOnly) 1170 SemaRef.Diag(expr->getLocStart(), 1171 diag::err_designator_for_scalar_init) 1172 << DeclType << expr->getSourceRange(); 1173 hadError = true; 1174 ++Index; 1175 ++StructuredIndex; 1176 return; 1177 } 1178 1179 if (VerifyOnly) { 1180 if (!SemaRef.CanPerformCopyInitialization(Entity,expr)) 1181 hadError = true; 1182 ++Index; 1183 return; 1184 } 1185 1186 ExprResult Result = 1187 SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), expr, 1188 /*TopLevelOfInitList=*/true); 1189 1190 Expr *ResultExpr = nullptr; 1191 1192 if (Result.isInvalid()) 1193 hadError = true; // types weren't compatible. 1194 else { 1195 ResultExpr = Result.getAs<Expr>(); 1196 1197 if (ResultExpr != expr) { 1198 // The type was promoted, update initializer list. 1199 IList->setInit(Index, ResultExpr); 1200 } 1201 } 1202 if (hadError) 1203 ++StructuredIndex; 1204 else 1205 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr); 1206 ++Index; 1207 } 1208 1209 void InitListChecker::CheckReferenceType(const InitializedEntity &Entity, 1210 InitListExpr *IList, QualType DeclType, 1211 unsigned &Index, 1212 InitListExpr *StructuredList, 1213 unsigned &StructuredIndex) { 1214 if (Index >= IList->getNumInits()) { 1215 // FIXME: It would be wonderful if we could point at the actual member. In 1216 // general, it would be useful to pass location information down the stack, 1217 // so that we know the location (or decl) of the "current object" being 1218 // initialized. 1219 if (!VerifyOnly) 1220 SemaRef.Diag(IList->getLocStart(), 1221 diag::err_init_reference_member_uninitialized) 1222 << DeclType 1223 << IList->getSourceRange(); 1224 hadError = true; 1225 ++Index; 1226 ++StructuredIndex; 1227 return; 1228 } 1229 1230 Expr *expr = IList->getInit(Index); 1231 if (isa<InitListExpr>(expr) && !SemaRef.getLangOpts().CPlusPlus11) { 1232 if (!VerifyOnly) 1233 SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list) 1234 << DeclType << IList->getSourceRange(); 1235 hadError = true; 1236 ++Index; 1237 ++StructuredIndex; 1238 return; 1239 } 1240 1241 if (VerifyOnly) { 1242 if (!SemaRef.CanPerformCopyInitialization(Entity,expr)) 1243 hadError = true; 1244 ++Index; 1245 return; 1246 } 1247 1248 ExprResult Result = 1249 SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), expr, 1250 /*TopLevelOfInitList=*/true); 1251 1252 if (Result.isInvalid()) 1253 hadError = true; 1254 1255 expr = Result.getAs<Expr>(); 1256 IList->setInit(Index, expr); 1257 1258 if (hadError) 1259 ++StructuredIndex; 1260 else 1261 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 1262 ++Index; 1263 } 1264 1265 void InitListChecker::CheckVectorType(const InitializedEntity &Entity, 1266 InitListExpr *IList, QualType DeclType, 1267 unsigned &Index, 1268 InitListExpr *StructuredList, 1269 unsigned &StructuredIndex) { 1270 const VectorType *VT = DeclType->getAs<VectorType>(); 1271 unsigned maxElements = VT->getNumElements(); 1272 unsigned numEltsInit = 0; 1273 QualType elementType = VT->getElementType(); 1274 1275 if (Index >= IList->getNumInits()) { 1276 // Make sure the element type can be value-initialized. 1277 if (VerifyOnly) 1278 CheckEmptyInitializable( 1279 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity), 1280 IList->getLocEnd()); 1281 return; 1282 } 1283 1284 if (!SemaRef.getLangOpts().OpenCL) { 1285 // If the initializing element is a vector, try to copy-initialize 1286 // instead of breaking it apart (which is doomed to failure anyway). 1287 Expr *Init = IList->getInit(Index); 1288 if (!isa<InitListExpr>(Init) && Init->getType()->isVectorType()) { 1289 if (VerifyOnly) { 1290 if (!SemaRef.CanPerformCopyInitialization(Entity, Init)) 1291 hadError = true; 1292 ++Index; 1293 return; 1294 } 1295 1296 ExprResult Result = 1297 SemaRef.PerformCopyInitialization(Entity, Init->getLocStart(), Init, 1298 /*TopLevelOfInitList=*/true); 1299 1300 Expr *ResultExpr = nullptr; 1301 if (Result.isInvalid()) 1302 hadError = true; // types weren't compatible. 1303 else { 1304 ResultExpr = Result.getAs<Expr>(); 1305 1306 if (ResultExpr != Init) { 1307 // The type was promoted, update initializer list. 1308 IList->setInit(Index, ResultExpr); 1309 } 1310 } 1311 if (hadError) 1312 ++StructuredIndex; 1313 else 1314 UpdateStructuredListElement(StructuredList, StructuredIndex, 1315 ResultExpr); 1316 ++Index; 1317 return; 1318 } 1319 1320 InitializedEntity ElementEntity = 1321 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 1322 1323 for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) { 1324 // Don't attempt to go past the end of the init list 1325 if (Index >= IList->getNumInits()) { 1326 if (VerifyOnly) 1327 CheckEmptyInitializable(ElementEntity, IList->getLocEnd()); 1328 break; 1329 } 1330 1331 ElementEntity.setElementIndex(Index); 1332 CheckSubElementType(ElementEntity, IList, elementType, Index, 1333 StructuredList, StructuredIndex); 1334 } 1335 1336 if (VerifyOnly) 1337 return; 1338 1339 bool isBigEndian = SemaRef.Context.getTargetInfo().isBigEndian(); 1340 const VectorType *T = Entity.getType()->getAs<VectorType>(); 1341 if (isBigEndian && (T->getVectorKind() == VectorType::NeonVector || 1342 T->getVectorKind() == VectorType::NeonPolyVector)) { 1343 // The ability to use vector initializer lists is a GNU vector extension 1344 // and is unrelated to the NEON intrinsics in arm_neon.h. On little 1345 // endian machines it works fine, however on big endian machines it 1346 // exhibits surprising behaviour: 1347 // 1348 // uint32x2_t x = {42, 64}; 1349 // return vget_lane_u32(x, 0); // Will return 64. 1350 // 1351 // Because of this, explicitly call out that it is non-portable. 1352 // 1353 SemaRef.Diag(IList->getLocStart(), 1354 diag::warn_neon_vector_initializer_non_portable); 1355 1356 const char *typeCode; 1357 unsigned typeSize = SemaRef.Context.getTypeSize(elementType); 1358 1359 if (elementType->isFloatingType()) 1360 typeCode = "f"; 1361 else if (elementType->isSignedIntegerType()) 1362 typeCode = "s"; 1363 else if (elementType->isUnsignedIntegerType()) 1364 typeCode = "u"; 1365 else 1366 llvm_unreachable("Invalid element type!"); 1367 1368 SemaRef.Diag(IList->getLocStart(), 1369 SemaRef.Context.getTypeSize(VT) > 64 ? 1370 diag::note_neon_vector_initializer_non_portable_q : 1371 diag::note_neon_vector_initializer_non_portable) 1372 << typeCode << typeSize; 1373 } 1374 1375 return; 1376 } 1377 1378 InitializedEntity ElementEntity = 1379 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 1380 1381 // OpenCL initializers allows vectors to be constructed from vectors. 1382 for (unsigned i = 0; i < maxElements; ++i) { 1383 // Don't attempt to go past the end of the init list 1384 if (Index >= IList->getNumInits()) 1385 break; 1386 1387 ElementEntity.setElementIndex(Index); 1388 1389 QualType IType = IList->getInit(Index)->getType(); 1390 if (!IType->isVectorType()) { 1391 CheckSubElementType(ElementEntity, IList, elementType, Index, 1392 StructuredList, StructuredIndex); 1393 ++numEltsInit; 1394 } else { 1395 QualType VecType; 1396 const VectorType *IVT = IType->getAs<VectorType>(); 1397 unsigned numIElts = IVT->getNumElements(); 1398 1399 if (IType->isExtVectorType()) 1400 VecType = SemaRef.Context.getExtVectorType(elementType, numIElts); 1401 else 1402 VecType = SemaRef.Context.getVectorType(elementType, numIElts, 1403 IVT->getVectorKind()); 1404 CheckSubElementType(ElementEntity, IList, VecType, Index, 1405 StructuredList, StructuredIndex); 1406 numEltsInit += numIElts; 1407 } 1408 } 1409 1410 // OpenCL requires all elements to be initialized. 1411 if (numEltsInit != maxElements) { 1412 if (!VerifyOnly) 1413 SemaRef.Diag(IList->getLocStart(), 1414 diag::err_vector_incorrect_num_initializers) 1415 << (numEltsInit < maxElements) << maxElements << numEltsInit; 1416 hadError = true; 1417 } 1418 } 1419 1420 void InitListChecker::CheckArrayType(const InitializedEntity &Entity, 1421 InitListExpr *IList, QualType &DeclType, 1422 llvm::APSInt elementIndex, 1423 bool SubobjectIsDesignatorContext, 1424 unsigned &Index, 1425 InitListExpr *StructuredList, 1426 unsigned &StructuredIndex) { 1427 const ArrayType *arrayType = SemaRef.Context.getAsArrayType(DeclType); 1428 1429 // Check for the special-case of initializing an array with a string. 1430 if (Index < IList->getNumInits()) { 1431 if (IsStringInit(IList->getInit(Index), arrayType, SemaRef.Context) == 1432 SIF_None) { 1433 // We place the string literal directly into the resulting 1434 // initializer list. This is the only place where the structure 1435 // of the structured initializer list doesn't match exactly, 1436 // because doing so would involve allocating one character 1437 // constant for each string. 1438 if (!VerifyOnly) { 1439 CheckStringInit(IList->getInit(Index), DeclType, arrayType, SemaRef); 1440 UpdateStructuredListElement(StructuredList, StructuredIndex, 1441 IList->getInit(Index)); 1442 StructuredList->resizeInits(SemaRef.Context, StructuredIndex); 1443 } 1444 ++Index; 1445 return; 1446 } 1447 } 1448 if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(arrayType)) { 1449 // Check for VLAs; in standard C it would be possible to check this 1450 // earlier, but I don't know where clang accepts VLAs (gcc accepts 1451 // them in all sorts of strange places). 1452 if (!VerifyOnly) 1453 SemaRef.Diag(VAT->getSizeExpr()->getLocStart(), 1454 diag::err_variable_object_no_init) 1455 << VAT->getSizeExpr()->getSourceRange(); 1456 hadError = true; 1457 ++Index; 1458 ++StructuredIndex; 1459 return; 1460 } 1461 1462 // We might know the maximum number of elements in advance. 1463 llvm::APSInt maxElements(elementIndex.getBitWidth(), 1464 elementIndex.isUnsigned()); 1465 bool maxElementsKnown = false; 1466 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(arrayType)) { 1467 maxElements = CAT->getSize(); 1468 elementIndex = elementIndex.extOrTrunc(maxElements.getBitWidth()); 1469 elementIndex.setIsUnsigned(maxElements.isUnsigned()); 1470 maxElementsKnown = true; 1471 } 1472 1473 QualType elementType = arrayType->getElementType(); 1474 while (Index < IList->getNumInits()) { 1475 Expr *Init = IList->getInit(Index); 1476 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) { 1477 // If we're not the subobject that matches up with the '{' for 1478 // the designator, we shouldn't be handling the 1479 // designator. Return immediately. 1480 if (!SubobjectIsDesignatorContext) 1481 return; 1482 1483 // Handle this designated initializer. elementIndex will be 1484 // updated to be the next array element we'll initialize. 1485 if (CheckDesignatedInitializer(Entity, IList, DIE, 0, 1486 DeclType, nullptr, &elementIndex, Index, 1487 StructuredList, StructuredIndex, true, 1488 false)) { 1489 hadError = true; 1490 continue; 1491 } 1492 1493 if (elementIndex.getBitWidth() > maxElements.getBitWidth()) 1494 maxElements = maxElements.extend(elementIndex.getBitWidth()); 1495 else if (elementIndex.getBitWidth() < maxElements.getBitWidth()) 1496 elementIndex = elementIndex.extend(maxElements.getBitWidth()); 1497 elementIndex.setIsUnsigned(maxElements.isUnsigned()); 1498 1499 // If the array is of incomplete type, keep track of the number of 1500 // elements in the initializer. 1501 if (!maxElementsKnown && elementIndex > maxElements) 1502 maxElements = elementIndex; 1503 1504 continue; 1505 } 1506 1507 // If we know the maximum number of elements, and we've already 1508 // hit it, stop consuming elements in the initializer list. 1509 if (maxElementsKnown && elementIndex == maxElements) 1510 break; 1511 1512 InitializedEntity ElementEntity = 1513 InitializedEntity::InitializeElement(SemaRef.Context, StructuredIndex, 1514 Entity); 1515 // Check this element. 1516 CheckSubElementType(ElementEntity, IList, elementType, Index, 1517 StructuredList, StructuredIndex); 1518 ++elementIndex; 1519 1520 // If the array is of incomplete type, keep track of the number of 1521 // elements in the initializer. 1522 if (!maxElementsKnown && elementIndex > maxElements) 1523 maxElements = elementIndex; 1524 } 1525 if (!hadError && DeclType->isIncompleteArrayType() && !VerifyOnly) { 1526 // If this is an incomplete array type, the actual type needs to 1527 // be calculated here. 1528 llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned()); 1529 if (maxElements == Zero) { 1530 // Sizing an array implicitly to zero is not allowed by ISO C, 1531 // but is supported by GNU. 1532 SemaRef.Diag(IList->getLocStart(), 1533 diag::ext_typecheck_zero_array_size); 1534 } 1535 1536 DeclType = SemaRef.Context.getConstantArrayType(elementType, maxElements, 1537 ArrayType::Normal, 0); 1538 } 1539 if (!hadError && VerifyOnly) { 1540 // Check if there are any members of the array that get value-initialized. 1541 // If so, check if doing that is possible. 1542 // FIXME: This needs to detect holes left by designated initializers too. 1543 if (maxElementsKnown && elementIndex < maxElements) 1544 CheckEmptyInitializable(InitializedEntity::InitializeElement( 1545 SemaRef.Context, 0, Entity), 1546 IList->getLocEnd()); 1547 } 1548 } 1549 1550 bool InitListChecker::CheckFlexibleArrayInit(const InitializedEntity &Entity, 1551 Expr *InitExpr, 1552 FieldDecl *Field, 1553 bool TopLevelObject) { 1554 // Handle GNU flexible array initializers. 1555 unsigned FlexArrayDiag; 1556 if (isa<InitListExpr>(InitExpr) && 1557 cast<InitListExpr>(InitExpr)->getNumInits() == 0) { 1558 // Empty flexible array init always allowed as an extension 1559 FlexArrayDiag = diag::ext_flexible_array_init; 1560 } else if (SemaRef.getLangOpts().CPlusPlus) { 1561 // Disallow flexible array init in C++; it is not required for gcc 1562 // compatibility, and it needs work to IRGen correctly in general. 1563 FlexArrayDiag = diag::err_flexible_array_init; 1564 } else if (!TopLevelObject) { 1565 // Disallow flexible array init on non-top-level object 1566 FlexArrayDiag = diag::err_flexible_array_init; 1567 } else if (Entity.getKind() != InitializedEntity::EK_Variable) { 1568 // Disallow flexible array init on anything which is not a variable. 1569 FlexArrayDiag = diag::err_flexible_array_init; 1570 } else if (cast<VarDecl>(Entity.getDecl())->hasLocalStorage()) { 1571 // Disallow flexible array init on local variables. 1572 FlexArrayDiag = diag::err_flexible_array_init; 1573 } else { 1574 // Allow other cases. 1575 FlexArrayDiag = diag::ext_flexible_array_init; 1576 } 1577 1578 if (!VerifyOnly) { 1579 SemaRef.Diag(InitExpr->getLocStart(), 1580 FlexArrayDiag) 1581 << InitExpr->getLocStart(); 1582 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1583 << Field; 1584 } 1585 1586 return FlexArrayDiag != diag::ext_flexible_array_init; 1587 } 1588 1589 void InitListChecker::CheckStructUnionTypes(const InitializedEntity &Entity, 1590 InitListExpr *IList, 1591 QualType DeclType, 1592 RecordDecl::field_iterator Field, 1593 bool SubobjectIsDesignatorContext, 1594 unsigned &Index, 1595 InitListExpr *StructuredList, 1596 unsigned &StructuredIndex, 1597 bool TopLevelObject) { 1598 RecordDecl* structDecl = DeclType->getAs<RecordType>()->getDecl(); 1599 1600 // If the record is invalid, some of it's members are invalid. To avoid 1601 // confusion, we forgo checking the intializer for the entire record. 1602 if (structDecl->isInvalidDecl()) { 1603 // Assume it was supposed to consume a single initializer. 1604 ++Index; 1605 hadError = true; 1606 return; 1607 } 1608 1609 if (DeclType->isUnionType() && IList->getNumInits() == 0) { 1610 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 1611 1612 // If there's a default initializer, use it. 1613 if (isa<CXXRecordDecl>(RD) && cast<CXXRecordDecl>(RD)->hasInClassInitializer()) { 1614 if (VerifyOnly) 1615 return; 1616 for (RecordDecl::field_iterator FieldEnd = RD->field_end(); 1617 Field != FieldEnd; ++Field) { 1618 if (Field->hasInClassInitializer()) { 1619 StructuredList->setInitializedFieldInUnion(*Field); 1620 // FIXME: Actually build a CXXDefaultInitExpr? 1621 return; 1622 } 1623 } 1624 } 1625 1626 // Value-initialize the first member of the union that isn't an unnamed 1627 // bitfield. 1628 for (RecordDecl::field_iterator FieldEnd = RD->field_end(); 1629 Field != FieldEnd; ++Field) { 1630 if (!Field->isUnnamedBitfield()) { 1631 if (VerifyOnly) 1632 CheckEmptyInitializable( 1633 InitializedEntity::InitializeMember(*Field, &Entity), 1634 IList->getLocEnd()); 1635 else 1636 StructuredList->setInitializedFieldInUnion(*Field); 1637 break; 1638 } 1639 } 1640 return; 1641 } 1642 1643 // If structDecl is a forward declaration, this loop won't do 1644 // anything except look at designated initializers; That's okay, 1645 // because an error should get printed out elsewhere. It might be 1646 // worthwhile to skip over the rest of the initializer, though. 1647 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 1648 RecordDecl::field_iterator FieldEnd = RD->field_end(); 1649 bool InitializedSomething = false; 1650 bool CheckForMissingFields = true; 1651 while (Index < IList->getNumInits()) { 1652 Expr *Init = IList->getInit(Index); 1653 1654 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) { 1655 // If we're not the subobject that matches up with the '{' for 1656 // the designator, we shouldn't be handling the 1657 // designator. Return immediately. 1658 if (!SubobjectIsDesignatorContext) 1659 return; 1660 1661 // Handle this designated initializer. Field will be updated to 1662 // the next field that we'll be initializing. 1663 if (CheckDesignatedInitializer(Entity, IList, DIE, 0, 1664 DeclType, &Field, nullptr, Index, 1665 StructuredList, StructuredIndex, 1666 true, TopLevelObject)) 1667 hadError = true; 1668 1669 InitializedSomething = true; 1670 1671 // Disable check for missing fields when designators are used. 1672 // This matches gcc behaviour. 1673 CheckForMissingFields = false; 1674 continue; 1675 } 1676 1677 if (Field == FieldEnd) { 1678 // We've run out of fields. We're done. 1679 break; 1680 } 1681 1682 // We've already initialized a member of a union. We're done. 1683 if (InitializedSomething && DeclType->isUnionType()) 1684 break; 1685 1686 // If we've hit the flexible array member at the end, we're done. 1687 if (Field->getType()->isIncompleteArrayType()) 1688 break; 1689 1690 if (Field->isUnnamedBitfield()) { 1691 // Don't initialize unnamed bitfields, e.g. "int : 20;" 1692 ++Field; 1693 continue; 1694 } 1695 1696 // Make sure we can use this declaration. 1697 bool InvalidUse; 1698 if (VerifyOnly) 1699 InvalidUse = !SemaRef.CanUseDecl(*Field); 1700 else 1701 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, 1702 IList->getInit(Index)->getLocStart()); 1703 if (InvalidUse) { 1704 ++Index; 1705 ++Field; 1706 hadError = true; 1707 continue; 1708 } 1709 1710 InitializedEntity MemberEntity = 1711 InitializedEntity::InitializeMember(*Field, &Entity); 1712 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1713 StructuredList, StructuredIndex); 1714 InitializedSomething = true; 1715 1716 if (DeclType->isUnionType() && !VerifyOnly) { 1717 // Initialize the first field within the union. 1718 StructuredList->setInitializedFieldInUnion(*Field); 1719 } 1720 1721 ++Field; 1722 } 1723 1724 // Emit warnings for missing struct field initializers. 1725 if (!VerifyOnly && InitializedSomething && CheckForMissingFields && 1726 Field != FieldEnd && !Field->getType()->isIncompleteArrayType() && 1727 !DeclType->isUnionType()) { 1728 // It is possible we have one or more unnamed bitfields remaining. 1729 // Find first (if any) named field and emit warning. 1730 for (RecordDecl::field_iterator it = Field, end = RD->field_end(); 1731 it != end; ++it) { 1732 if (!it->isUnnamedBitfield() && !it->hasInClassInitializer()) { 1733 SemaRef.Diag(IList->getSourceRange().getEnd(), 1734 diag::warn_missing_field_initializers) << *it; 1735 break; 1736 } 1737 } 1738 } 1739 1740 // Check that any remaining fields can be value-initialized. 1741 if (VerifyOnly && Field != FieldEnd && !DeclType->isUnionType() && 1742 !Field->getType()->isIncompleteArrayType()) { 1743 // FIXME: Should check for holes left by designated initializers too. 1744 for (; Field != FieldEnd && !hadError; ++Field) { 1745 if (!Field->isUnnamedBitfield() && !Field->hasInClassInitializer()) 1746 CheckEmptyInitializable( 1747 InitializedEntity::InitializeMember(*Field, &Entity), 1748 IList->getLocEnd()); 1749 } 1750 } 1751 1752 if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() || 1753 Index >= IList->getNumInits()) 1754 return; 1755 1756 if (CheckFlexibleArrayInit(Entity, IList->getInit(Index), *Field, 1757 TopLevelObject)) { 1758 hadError = true; 1759 ++Index; 1760 return; 1761 } 1762 1763 InitializedEntity MemberEntity = 1764 InitializedEntity::InitializeMember(*Field, &Entity); 1765 1766 if (isa<InitListExpr>(IList->getInit(Index))) 1767 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1768 StructuredList, StructuredIndex); 1769 else 1770 CheckImplicitInitList(MemberEntity, IList, Field->getType(), Index, 1771 StructuredList, StructuredIndex); 1772 } 1773 1774 /// \brief Expand a field designator that refers to a member of an 1775 /// anonymous struct or union into a series of field designators that 1776 /// refers to the field within the appropriate subobject. 1777 /// 1778 static void ExpandAnonymousFieldDesignator(Sema &SemaRef, 1779 DesignatedInitExpr *DIE, 1780 unsigned DesigIdx, 1781 IndirectFieldDecl *IndirectField) { 1782 typedef DesignatedInitExpr::Designator Designator; 1783 1784 // Build the replacement designators. 1785 SmallVector<Designator, 4> Replacements; 1786 for (IndirectFieldDecl::chain_iterator PI = IndirectField->chain_begin(), 1787 PE = IndirectField->chain_end(); PI != PE; ++PI) { 1788 if (PI + 1 == PE) 1789 Replacements.push_back(Designator((IdentifierInfo *)nullptr, 1790 DIE->getDesignator(DesigIdx)->getDotLoc(), 1791 DIE->getDesignator(DesigIdx)->getFieldLoc())); 1792 else 1793 Replacements.push_back(Designator((IdentifierInfo *)nullptr, 1794 SourceLocation(), SourceLocation())); 1795 assert(isa<FieldDecl>(*PI)); 1796 Replacements.back().setField(cast<FieldDecl>(*PI)); 1797 } 1798 1799 // Expand the current designator into the set of replacement 1800 // designators, so we have a full subobject path down to where the 1801 // member of the anonymous struct/union is actually stored. 1802 DIE->ExpandDesignator(SemaRef.Context, DesigIdx, &Replacements[0], 1803 &Replacements[0] + Replacements.size()); 1804 } 1805 1806 static DesignatedInitExpr *CloneDesignatedInitExpr(Sema &SemaRef, 1807 DesignatedInitExpr *DIE) { 1808 unsigned NumIndexExprs = DIE->getNumSubExprs() - 1; 1809 SmallVector<Expr*, 4> IndexExprs(NumIndexExprs); 1810 for (unsigned I = 0; I < NumIndexExprs; ++I) 1811 IndexExprs[I] = DIE->getSubExpr(I + 1); 1812 return DesignatedInitExpr::Create(SemaRef.Context, DIE->designators_begin(), 1813 DIE->size(), IndexExprs, 1814 DIE->getEqualOrColonLoc(), 1815 DIE->usesGNUSyntax(), DIE->getInit()); 1816 } 1817 1818 namespace { 1819 1820 // Callback to only accept typo corrections that are for field members of 1821 // the given struct or union. 1822 class FieldInitializerValidatorCCC : public CorrectionCandidateCallback { 1823 public: 1824 explicit FieldInitializerValidatorCCC(RecordDecl *RD) 1825 : Record(RD) {} 1826 1827 bool ValidateCandidate(const TypoCorrection &candidate) override { 1828 FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>(); 1829 return FD && FD->getDeclContext()->getRedeclContext()->Equals(Record); 1830 } 1831 1832 private: 1833 RecordDecl *Record; 1834 }; 1835 1836 } 1837 1838 /// @brief Check the well-formedness of a C99 designated initializer. 1839 /// 1840 /// Determines whether the designated initializer @p DIE, which 1841 /// resides at the given @p Index within the initializer list @p 1842 /// IList, is well-formed for a current object of type @p DeclType 1843 /// (C99 6.7.8). The actual subobject that this designator refers to 1844 /// within the current subobject is returned in either 1845 /// @p NextField or @p NextElementIndex (whichever is appropriate). 1846 /// 1847 /// @param IList The initializer list in which this designated 1848 /// initializer occurs. 1849 /// 1850 /// @param DIE The designated initializer expression. 1851 /// 1852 /// @param DesigIdx The index of the current designator. 1853 /// 1854 /// @param CurrentObjectType The type of the "current object" (C99 6.7.8p17), 1855 /// into which the designation in @p DIE should refer. 1856 /// 1857 /// @param NextField If non-NULL and the first designator in @p DIE is 1858 /// a field, this will be set to the field declaration corresponding 1859 /// to the field named by the designator. 1860 /// 1861 /// @param NextElementIndex If non-NULL and the first designator in @p 1862 /// DIE is an array designator or GNU array-range designator, this 1863 /// will be set to the last index initialized by this designator. 1864 /// 1865 /// @param Index Index into @p IList where the designated initializer 1866 /// @p DIE occurs. 1867 /// 1868 /// @param StructuredList The initializer list expression that 1869 /// describes all of the subobject initializers in the order they'll 1870 /// actually be initialized. 1871 /// 1872 /// @returns true if there was an error, false otherwise. 1873 bool 1874 InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity, 1875 InitListExpr *IList, 1876 DesignatedInitExpr *DIE, 1877 unsigned DesigIdx, 1878 QualType &CurrentObjectType, 1879 RecordDecl::field_iterator *NextField, 1880 llvm::APSInt *NextElementIndex, 1881 unsigned &Index, 1882 InitListExpr *StructuredList, 1883 unsigned &StructuredIndex, 1884 bool FinishSubobjectInit, 1885 bool TopLevelObject) { 1886 if (DesigIdx == DIE->size()) { 1887 // Check the actual initialization for the designated object type. 1888 bool prevHadError = hadError; 1889 1890 // Temporarily remove the designator expression from the 1891 // initializer list that the child calls see, so that we don't try 1892 // to re-process the designator. 1893 unsigned OldIndex = Index; 1894 IList->setInit(OldIndex, DIE->getInit()); 1895 1896 CheckSubElementType(Entity, IList, CurrentObjectType, Index, 1897 StructuredList, StructuredIndex); 1898 1899 // Restore the designated initializer expression in the syntactic 1900 // form of the initializer list. 1901 if (IList->getInit(OldIndex) != DIE->getInit()) 1902 DIE->setInit(IList->getInit(OldIndex)); 1903 IList->setInit(OldIndex, DIE); 1904 1905 return hadError && !prevHadError; 1906 } 1907 1908 DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx); 1909 bool IsFirstDesignator = (DesigIdx == 0); 1910 if (!VerifyOnly) { 1911 assert((IsFirstDesignator || StructuredList) && 1912 "Need a non-designated initializer list to start from"); 1913 1914 // Determine the structural initializer list that corresponds to the 1915 // current subobject. 1916 StructuredList = IsFirstDesignator? SyntacticToSemantic.lookup(IList) 1917 : getStructuredSubobjectInit(IList, Index, CurrentObjectType, 1918 StructuredList, StructuredIndex, 1919 SourceRange(D->getLocStart(), 1920 DIE->getLocEnd())); 1921 assert(StructuredList && "Expected a structured initializer list"); 1922 } 1923 1924 if (D->isFieldDesignator()) { 1925 // C99 6.7.8p7: 1926 // 1927 // If a designator has the form 1928 // 1929 // . identifier 1930 // 1931 // then the current object (defined below) shall have 1932 // structure or union type and the identifier shall be the 1933 // name of a member of that type. 1934 const RecordType *RT = CurrentObjectType->getAs<RecordType>(); 1935 if (!RT) { 1936 SourceLocation Loc = D->getDotLoc(); 1937 if (Loc.isInvalid()) 1938 Loc = D->getFieldLoc(); 1939 if (!VerifyOnly) 1940 SemaRef.Diag(Loc, diag::err_field_designator_non_aggr) 1941 << SemaRef.getLangOpts().CPlusPlus << CurrentObjectType; 1942 ++Index; 1943 return true; 1944 } 1945 1946 FieldDecl *KnownField = D->getField(); 1947 if (!KnownField) { 1948 IdentifierInfo *FieldName = D->getFieldName(); 1949 DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName); 1950 for (NamedDecl *ND : Lookup) { 1951 if (auto *FD = dyn_cast<FieldDecl>(ND)) { 1952 KnownField = FD; 1953 break; 1954 } 1955 if (auto *IFD = dyn_cast<IndirectFieldDecl>(ND)) { 1956 // In verify mode, don't modify the original. 1957 if (VerifyOnly) 1958 DIE = CloneDesignatedInitExpr(SemaRef, DIE); 1959 ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IFD); 1960 D = DIE->getDesignator(DesigIdx); 1961 KnownField = cast<FieldDecl>(*IFD->chain_begin()); 1962 break; 1963 } 1964 } 1965 if (!KnownField) { 1966 if (VerifyOnly) { 1967 ++Index; 1968 return true; // No typo correction when just trying this out. 1969 } 1970 1971 // Name lookup found something, but it wasn't a field. 1972 if (!Lookup.empty()) { 1973 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield) 1974 << FieldName; 1975 SemaRef.Diag(Lookup.front()->getLocation(), 1976 diag::note_field_designator_found); 1977 ++Index; 1978 return true; 1979 } 1980 1981 // Name lookup didn't find anything. 1982 // Determine whether this was a typo for another field name. 1983 if (TypoCorrection Corrected = SemaRef.CorrectTypo( 1984 DeclarationNameInfo(FieldName, D->getFieldLoc()), 1985 Sema::LookupMemberName, /*Scope=*/nullptr, /*SS=*/nullptr, 1986 llvm::make_unique<FieldInitializerValidatorCCC>(RT->getDecl()), 1987 Sema::CTK_ErrorRecovery, RT->getDecl())) { 1988 SemaRef.diagnoseTypo( 1989 Corrected, 1990 SemaRef.PDiag(diag::err_field_designator_unknown_suggest) 1991 << FieldName << CurrentObjectType); 1992 KnownField = Corrected.getCorrectionDeclAs<FieldDecl>(); 1993 hadError = true; 1994 } else { 1995 // Typo correction didn't find anything. 1996 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown) 1997 << FieldName << CurrentObjectType; 1998 ++Index; 1999 return true; 2000 } 2001 } 2002 } 2003 2004 unsigned FieldIndex = 0; 2005 for (auto *FI : RT->getDecl()->fields()) { 2006 if (FI->isUnnamedBitfield()) 2007 continue; 2008 if (KnownField == FI) 2009 break; 2010 ++FieldIndex; 2011 } 2012 2013 RecordDecl::field_iterator Field = 2014 RecordDecl::field_iterator(DeclContext::decl_iterator(KnownField)); 2015 2016 // All of the fields of a union are located at the same place in 2017 // the initializer list. 2018 if (RT->getDecl()->isUnion()) { 2019 FieldIndex = 0; 2020 if (!VerifyOnly) { 2021 FieldDecl *CurrentField = StructuredList->getInitializedFieldInUnion(); 2022 if (CurrentField && CurrentField != *Field) { 2023 assert(StructuredList->getNumInits() == 1 2024 && "A union should never have more than one initializer!"); 2025 2026 // we're about to throw away an initializer, emit warning 2027 SemaRef.Diag(D->getFieldLoc(), 2028 diag::warn_initializer_overrides) 2029 << D->getSourceRange(); 2030 Expr *ExistingInit = StructuredList->getInit(0); 2031 SemaRef.Diag(ExistingInit->getLocStart(), 2032 diag::note_previous_initializer) 2033 << /*FIXME:has side effects=*/0 2034 << ExistingInit->getSourceRange(); 2035 2036 // remove existing initializer 2037 StructuredList->resizeInits(SemaRef.Context, 0); 2038 StructuredList->setInitializedFieldInUnion(nullptr); 2039 } 2040 2041 StructuredList->setInitializedFieldInUnion(*Field); 2042 } 2043 } 2044 2045 // Make sure we can use this declaration. 2046 bool InvalidUse; 2047 if (VerifyOnly) 2048 InvalidUse = !SemaRef.CanUseDecl(*Field); 2049 else 2050 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc()); 2051 if (InvalidUse) { 2052 ++Index; 2053 return true; 2054 } 2055 2056 if (!VerifyOnly) { 2057 // Update the designator with the field declaration. 2058 D->setField(*Field); 2059 2060 // Make sure that our non-designated initializer list has space 2061 // for a subobject corresponding to this field. 2062 if (FieldIndex >= StructuredList->getNumInits()) 2063 StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1); 2064 } 2065 2066 // This designator names a flexible array member. 2067 if (Field->getType()->isIncompleteArrayType()) { 2068 bool Invalid = false; 2069 if ((DesigIdx + 1) != DIE->size()) { 2070 // We can't designate an object within the flexible array 2071 // member (because GCC doesn't allow it). 2072 if (!VerifyOnly) { 2073 DesignatedInitExpr::Designator *NextD 2074 = DIE->getDesignator(DesigIdx + 1); 2075 SemaRef.Diag(NextD->getLocStart(), 2076 diag::err_designator_into_flexible_array_member) 2077 << SourceRange(NextD->getLocStart(), 2078 DIE->getLocEnd()); 2079 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 2080 << *Field; 2081 } 2082 Invalid = true; 2083 } 2084 2085 if (!hadError && !isa<InitListExpr>(DIE->getInit()) && 2086 !isa<StringLiteral>(DIE->getInit())) { 2087 // The initializer is not an initializer list. 2088 if (!VerifyOnly) { 2089 SemaRef.Diag(DIE->getInit()->getLocStart(), 2090 diag::err_flexible_array_init_needs_braces) 2091 << DIE->getInit()->getSourceRange(); 2092 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 2093 << *Field; 2094 } 2095 Invalid = true; 2096 } 2097 2098 // Check GNU flexible array initializer. 2099 if (!Invalid && CheckFlexibleArrayInit(Entity, DIE->getInit(), *Field, 2100 TopLevelObject)) 2101 Invalid = true; 2102 2103 if (Invalid) { 2104 ++Index; 2105 return true; 2106 } 2107 2108 // Initialize the array. 2109 bool prevHadError = hadError; 2110 unsigned newStructuredIndex = FieldIndex; 2111 unsigned OldIndex = Index; 2112 IList->setInit(Index, DIE->getInit()); 2113 2114 InitializedEntity MemberEntity = 2115 InitializedEntity::InitializeMember(*Field, &Entity); 2116 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 2117 StructuredList, newStructuredIndex); 2118 2119 IList->setInit(OldIndex, DIE); 2120 if (hadError && !prevHadError) { 2121 ++Field; 2122 ++FieldIndex; 2123 if (NextField) 2124 *NextField = Field; 2125 StructuredIndex = FieldIndex; 2126 return true; 2127 } 2128 } else { 2129 // Recurse to check later designated subobjects. 2130 QualType FieldType = Field->getType(); 2131 unsigned newStructuredIndex = FieldIndex; 2132 2133 InitializedEntity MemberEntity = 2134 InitializedEntity::InitializeMember(*Field, &Entity); 2135 if (CheckDesignatedInitializer(MemberEntity, IList, DIE, DesigIdx + 1, 2136 FieldType, nullptr, nullptr, Index, 2137 StructuredList, newStructuredIndex, 2138 true, false)) 2139 return true; 2140 } 2141 2142 // Find the position of the next field to be initialized in this 2143 // subobject. 2144 ++Field; 2145 ++FieldIndex; 2146 2147 // If this the first designator, our caller will continue checking 2148 // the rest of this struct/class/union subobject. 2149 if (IsFirstDesignator) { 2150 if (NextField) 2151 *NextField = Field; 2152 StructuredIndex = FieldIndex; 2153 return false; 2154 } 2155 2156 if (!FinishSubobjectInit) 2157 return false; 2158 2159 // We've already initialized something in the union; we're done. 2160 if (RT->getDecl()->isUnion()) 2161 return hadError; 2162 2163 // Check the remaining fields within this class/struct/union subobject. 2164 bool prevHadError = hadError; 2165 2166 CheckStructUnionTypes(Entity, IList, CurrentObjectType, Field, false, Index, 2167 StructuredList, FieldIndex); 2168 return hadError && !prevHadError; 2169 } 2170 2171 // C99 6.7.8p6: 2172 // 2173 // If a designator has the form 2174 // 2175 // [ constant-expression ] 2176 // 2177 // then the current object (defined below) shall have array 2178 // type and the expression shall be an integer constant 2179 // expression. If the array is of unknown size, any 2180 // nonnegative value is valid. 2181 // 2182 // Additionally, cope with the GNU extension that permits 2183 // designators of the form 2184 // 2185 // [ constant-expression ... constant-expression ] 2186 const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType); 2187 if (!AT) { 2188 if (!VerifyOnly) 2189 SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array) 2190 << CurrentObjectType; 2191 ++Index; 2192 return true; 2193 } 2194 2195 Expr *IndexExpr = nullptr; 2196 llvm::APSInt DesignatedStartIndex, DesignatedEndIndex; 2197 if (D->isArrayDesignator()) { 2198 IndexExpr = DIE->getArrayIndex(*D); 2199 DesignatedStartIndex = IndexExpr->EvaluateKnownConstInt(SemaRef.Context); 2200 DesignatedEndIndex = DesignatedStartIndex; 2201 } else { 2202 assert(D->isArrayRangeDesignator() && "Need array-range designator"); 2203 2204 DesignatedStartIndex = 2205 DIE->getArrayRangeStart(*D)->EvaluateKnownConstInt(SemaRef.Context); 2206 DesignatedEndIndex = 2207 DIE->getArrayRangeEnd(*D)->EvaluateKnownConstInt(SemaRef.Context); 2208 IndexExpr = DIE->getArrayRangeEnd(*D); 2209 2210 // Codegen can't handle evaluating array range designators that have side 2211 // effects, because we replicate the AST value for each initialized element. 2212 // As such, set the sawArrayRangeDesignator() bit if we initialize multiple 2213 // elements with something that has a side effect, so codegen can emit an 2214 // "error unsupported" error instead of miscompiling the app. 2215 if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&& 2216 DIE->getInit()->HasSideEffects(SemaRef.Context) && !VerifyOnly) 2217 FullyStructuredList->sawArrayRangeDesignator(); 2218 } 2219 2220 if (isa<ConstantArrayType>(AT)) { 2221 llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false); 2222 DesignatedStartIndex 2223 = DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth()); 2224 DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned()); 2225 DesignatedEndIndex 2226 = DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth()); 2227 DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned()); 2228 if (DesignatedEndIndex >= MaxElements) { 2229 if (!VerifyOnly) 2230 SemaRef.Diag(IndexExpr->getLocStart(), 2231 diag::err_array_designator_too_large) 2232 << DesignatedEndIndex.toString(10) << MaxElements.toString(10) 2233 << IndexExpr->getSourceRange(); 2234 ++Index; 2235 return true; 2236 } 2237 } else { 2238 // Make sure the bit-widths and signedness match. 2239 if (DesignatedStartIndex.getBitWidth() > DesignatedEndIndex.getBitWidth()) 2240 DesignatedEndIndex 2241 = DesignatedEndIndex.extend(DesignatedStartIndex.getBitWidth()); 2242 else if (DesignatedStartIndex.getBitWidth() < 2243 DesignatedEndIndex.getBitWidth()) 2244 DesignatedStartIndex 2245 = DesignatedStartIndex.extend(DesignatedEndIndex.getBitWidth()); 2246 DesignatedStartIndex.setIsUnsigned(true); 2247 DesignatedEndIndex.setIsUnsigned(true); 2248 } 2249 2250 if (!VerifyOnly && StructuredList->isStringLiteralInit()) { 2251 // We're modifying a string literal init; we have to decompose the string 2252 // so we can modify the individual characters. 2253 ASTContext &Context = SemaRef.Context; 2254 Expr *SubExpr = StructuredList->getInit(0)->IgnoreParens(); 2255 2256 // Compute the character type 2257 QualType CharTy = AT->getElementType(); 2258 2259 // Compute the type of the integer literals. 2260 QualType PromotedCharTy = CharTy; 2261 if (CharTy->isPromotableIntegerType()) 2262 PromotedCharTy = Context.getPromotedIntegerType(CharTy); 2263 unsigned PromotedCharTyWidth = Context.getTypeSize(PromotedCharTy); 2264 2265 if (StringLiteral *SL = dyn_cast<StringLiteral>(SubExpr)) { 2266 // Get the length of the string. 2267 uint64_t StrLen = SL->getLength(); 2268 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen)) 2269 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue(); 2270 StructuredList->resizeInits(Context, StrLen); 2271 2272 // Build a literal for each character in the string, and put them into 2273 // the init list. 2274 for (unsigned i = 0, e = StrLen; i != e; ++i) { 2275 llvm::APInt CodeUnit(PromotedCharTyWidth, SL->getCodeUnit(i)); 2276 Expr *Init = new (Context) IntegerLiteral( 2277 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc()); 2278 if (CharTy != PromotedCharTy) 2279 Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast, 2280 Init, nullptr, VK_RValue); 2281 StructuredList->updateInit(Context, i, Init); 2282 } 2283 } else { 2284 ObjCEncodeExpr *E = cast<ObjCEncodeExpr>(SubExpr); 2285 std::string Str; 2286 Context.getObjCEncodingForType(E->getEncodedType(), Str); 2287 2288 // Get the length of the string. 2289 uint64_t StrLen = Str.size(); 2290 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen)) 2291 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue(); 2292 StructuredList->resizeInits(Context, StrLen); 2293 2294 // Build a literal for each character in the string, and put them into 2295 // the init list. 2296 for (unsigned i = 0, e = StrLen; i != e; ++i) { 2297 llvm::APInt CodeUnit(PromotedCharTyWidth, Str[i]); 2298 Expr *Init = new (Context) IntegerLiteral( 2299 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc()); 2300 if (CharTy != PromotedCharTy) 2301 Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast, 2302 Init, nullptr, VK_RValue); 2303 StructuredList->updateInit(Context, i, Init); 2304 } 2305 } 2306 } 2307 2308 // Make sure that our non-designated initializer list has space 2309 // for a subobject corresponding to this array element. 2310 if (!VerifyOnly && 2311 DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits()) 2312 StructuredList->resizeInits(SemaRef.Context, 2313 DesignatedEndIndex.getZExtValue() + 1); 2314 2315 // Repeatedly perform subobject initializations in the range 2316 // [DesignatedStartIndex, DesignatedEndIndex]. 2317 2318 // Move to the next designator 2319 unsigned ElementIndex = DesignatedStartIndex.getZExtValue(); 2320 unsigned OldIndex = Index; 2321 2322 InitializedEntity ElementEntity = 2323 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 2324 2325 while (DesignatedStartIndex <= DesignatedEndIndex) { 2326 // Recurse to check later designated subobjects. 2327 QualType ElementType = AT->getElementType(); 2328 Index = OldIndex; 2329 2330 ElementEntity.setElementIndex(ElementIndex); 2331 if (CheckDesignatedInitializer(ElementEntity, IList, DIE, DesigIdx + 1, 2332 ElementType, nullptr, nullptr, Index, 2333 StructuredList, ElementIndex, 2334 (DesignatedStartIndex == DesignatedEndIndex), 2335 false)) 2336 return true; 2337 2338 // Move to the next index in the array that we'll be initializing. 2339 ++DesignatedStartIndex; 2340 ElementIndex = DesignatedStartIndex.getZExtValue(); 2341 } 2342 2343 // If this the first designator, our caller will continue checking 2344 // the rest of this array subobject. 2345 if (IsFirstDesignator) { 2346 if (NextElementIndex) 2347 *NextElementIndex = DesignatedStartIndex; 2348 StructuredIndex = ElementIndex; 2349 return false; 2350 } 2351 2352 if (!FinishSubobjectInit) 2353 return false; 2354 2355 // Check the remaining elements within this array subobject. 2356 bool prevHadError = hadError; 2357 CheckArrayType(Entity, IList, CurrentObjectType, DesignatedStartIndex, 2358 /*SubobjectIsDesignatorContext=*/false, Index, 2359 StructuredList, ElementIndex); 2360 return hadError && !prevHadError; 2361 } 2362 2363 // Get the structured initializer list for a subobject of type 2364 // @p CurrentObjectType. 2365 InitListExpr * 2366 InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index, 2367 QualType CurrentObjectType, 2368 InitListExpr *StructuredList, 2369 unsigned StructuredIndex, 2370 SourceRange InitRange) { 2371 if (VerifyOnly) 2372 return nullptr; // No structured list in verification-only mode. 2373 Expr *ExistingInit = nullptr; 2374 if (!StructuredList) 2375 ExistingInit = SyntacticToSemantic.lookup(IList); 2376 else if (StructuredIndex < StructuredList->getNumInits()) 2377 ExistingInit = StructuredList->getInit(StructuredIndex); 2378 2379 if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit)) 2380 return Result; 2381 2382 if (ExistingInit) { 2383 // We are creating an initializer list that initializes the 2384 // subobjects of the current object, but there was already an 2385 // initialization that completely initialized the current 2386 // subobject, e.g., by a compound literal: 2387 // 2388 // struct X { int a, b; }; 2389 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 }; 2390 // 2391 // Here, xs[0].a == 0 and xs[0].b == 3, since the second, 2392 // designated initializer re-initializes the whole 2393 // subobject [0], overwriting previous initializers. 2394 SemaRef.Diag(InitRange.getBegin(), 2395 diag::warn_subobject_initializer_overrides) 2396 << InitRange; 2397 SemaRef.Diag(ExistingInit->getLocStart(), 2398 diag::note_previous_initializer) 2399 << /*FIXME:has side effects=*/0 2400 << ExistingInit->getSourceRange(); 2401 } 2402 2403 InitListExpr *Result 2404 = new (SemaRef.Context) InitListExpr(SemaRef.Context, 2405 InitRange.getBegin(), None, 2406 InitRange.getEnd()); 2407 2408 QualType ResultType = CurrentObjectType; 2409 if (!ResultType->isArrayType()) 2410 ResultType = ResultType.getNonLValueExprType(SemaRef.Context); 2411 Result->setType(ResultType); 2412 2413 // Pre-allocate storage for the structured initializer list. 2414 unsigned NumElements = 0; 2415 unsigned NumInits = 0; 2416 bool GotNumInits = false; 2417 if (!StructuredList) { 2418 NumInits = IList->getNumInits(); 2419 GotNumInits = true; 2420 } else if (Index < IList->getNumInits()) { 2421 if (InitListExpr *SubList = dyn_cast<InitListExpr>(IList->getInit(Index))) { 2422 NumInits = SubList->getNumInits(); 2423 GotNumInits = true; 2424 } 2425 } 2426 2427 if (const ArrayType *AType 2428 = SemaRef.Context.getAsArrayType(CurrentObjectType)) { 2429 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) { 2430 NumElements = CAType->getSize().getZExtValue(); 2431 // Simple heuristic so that we don't allocate a very large 2432 // initializer with many empty entries at the end. 2433 if (GotNumInits && NumElements > NumInits) 2434 NumElements = 0; 2435 } 2436 } else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>()) 2437 NumElements = VType->getNumElements(); 2438 else if (const RecordType *RType = CurrentObjectType->getAs<RecordType>()) { 2439 RecordDecl *RDecl = RType->getDecl(); 2440 if (RDecl->isUnion()) 2441 NumElements = 1; 2442 else 2443 NumElements = std::distance(RDecl->field_begin(), RDecl->field_end()); 2444 } 2445 2446 Result->reserveInits(SemaRef.Context, NumElements); 2447 2448 // Link this new initializer list into the structured initializer 2449 // lists. 2450 if (StructuredList) 2451 StructuredList->updateInit(SemaRef.Context, StructuredIndex, Result); 2452 else { 2453 Result->setSyntacticForm(IList); 2454 SyntacticToSemantic[IList] = Result; 2455 } 2456 2457 return Result; 2458 } 2459 2460 /// Update the initializer at index @p StructuredIndex within the 2461 /// structured initializer list to the value @p expr. 2462 void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList, 2463 unsigned &StructuredIndex, 2464 Expr *expr) { 2465 // No structured initializer list to update 2466 if (!StructuredList) 2467 return; 2468 2469 if (Expr *PrevInit = StructuredList->updateInit(SemaRef.Context, 2470 StructuredIndex, expr)) { 2471 // This initializer overwrites a previous initializer. Warn. 2472 SemaRef.Diag(expr->getLocStart(), 2473 diag::warn_initializer_overrides) 2474 << expr->getSourceRange(); 2475 SemaRef.Diag(PrevInit->getLocStart(), 2476 diag::note_previous_initializer) 2477 << /*FIXME:has side effects=*/0 2478 << PrevInit->getSourceRange(); 2479 } 2480 2481 ++StructuredIndex; 2482 } 2483 2484 /// Check that the given Index expression is a valid array designator 2485 /// value. This is essentially just a wrapper around 2486 /// VerifyIntegerConstantExpression that also checks for negative values 2487 /// and produces a reasonable diagnostic if there is a 2488 /// failure. Returns the index expression, possibly with an implicit cast 2489 /// added, on success. If everything went okay, Value will receive the 2490 /// value of the constant expression. 2491 static ExprResult 2492 CheckArrayDesignatorExpr(Sema &S, Expr *Index, llvm::APSInt &Value) { 2493 SourceLocation Loc = Index->getLocStart(); 2494 2495 // Make sure this is an integer constant expression. 2496 ExprResult Result = S.VerifyIntegerConstantExpression(Index, &Value); 2497 if (Result.isInvalid()) 2498 return Result; 2499 2500 if (Value.isSigned() && Value.isNegative()) 2501 return S.Diag(Loc, diag::err_array_designator_negative) 2502 << Value.toString(10) << Index->getSourceRange(); 2503 2504 Value.setIsUnsigned(true); 2505 return Result; 2506 } 2507 2508 ExprResult Sema::ActOnDesignatedInitializer(Designation &Desig, 2509 SourceLocation Loc, 2510 bool GNUSyntax, 2511 ExprResult Init) { 2512 typedef DesignatedInitExpr::Designator ASTDesignator; 2513 2514 bool Invalid = false; 2515 SmallVector<ASTDesignator, 32> Designators; 2516 SmallVector<Expr *, 32> InitExpressions; 2517 2518 // Build designators and check array designator expressions. 2519 for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) { 2520 const Designator &D = Desig.getDesignator(Idx); 2521 switch (D.getKind()) { 2522 case Designator::FieldDesignator: 2523 Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(), 2524 D.getFieldLoc())); 2525 break; 2526 2527 case Designator::ArrayDesignator: { 2528 Expr *Index = static_cast<Expr *>(D.getArrayIndex()); 2529 llvm::APSInt IndexValue; 2530 if (!Index->isTypeDependent() && !Index->isValueDependent()) 2531 Index = CheckArrayDesignatorExpr(*this, Index, IndexValue).get(); 2532 if (!Index) 2533 Invalid = true; 2534 else { 2535 Designators.push_back(ASTDesignator(InitExpressions.size(), 2536 D.getLBracketLoc(), 2537 D.getRBracketLoc())); 2538 InitExpressions.push_back(Index); 2539 } 2540 break; 2541 } 2542 2543 case Designator::ArrayRangeDesignator: { 2544 Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart()); 2545 Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd()); 2546 llvm::APSInt StartValue; 2547 llvm::APSInt EndValue; 2548 bool StartDependent = StartIndex->isTypeDependent() || 2549 StartIndex->isValueDependent(); 2550 bool EndDependent = EndIndex->isTypeDependent() || 2551 EndIndex->isValueDependent(); 2552 if (!StartDependent) 2553 StartIndex = 2554 CheckArrayDesignatorExpr(*this, StartIndex, StartValue).get(); 2555 if (!EndDependent) 2556 EndIndex = CheckArrayDesignatorExpr(*this, EndIndex, EndValue).get(); 2557 2558 if (!StartIndex || !EndIndex) 2559 Invalid = true; 2560 else { 2561 // Make sure we're comparing values with the same bit width. 2562 if (StartDependent || EndDependent) { 2563 // Nothing to compute. 2564 } else if (StartValue.getBitWidth() > EndValue.getBitWidth()) 2565 EndValue = EndValue.extend(StartValue.getBitWidth()); 2566 else if (StartValue.getBitWidth() < EndValue.getBitWidth()) 2567 StartValue = StartValue.extend(EndValue.getBitWidth()); 2568 2569 if (!StartDependent && !EndDependent && EndValue < StartValue) { 2570 Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range) 2571 << StartValue.toString(10) << EndValue.toString(10) 2572 << StartIndex->getSourceRange() << EndIndex->getSourceRange(); 2573 Invalid = true; 2574 } else { 2575 Designators.push_back(ASTDesignator(InitExpressions.size(), 2576 D.getLBracketLoc(), 2577 D.getEllipsisLoc(), 2578 D.getRBracketLoc())); 2579 InitExpressions.push_back(StartIndex); 2580 InitExpressions.push_back(EndIndex); 2581 } 2582 } 2583 break; 2584 } 2585 } 2586 } 2587 2588 if (Invalid || Init.isInvalid()) 2589 return ExprError(); 2590 2591 // Clear out the expressions within the designation. 2592 Desig.ClearExprs(*this); 2593 2594 DesignatedInitExpr *DIE 2595 = DesignatedInitExpr::Create(Context, 2596 Designators.data(), Designators.size(), 2597 InitExpressions, Loc, GNUSyntax, 2598 Init.getAs<Expr>()); 2599 2600 if (!getLangOpts().C99) 2601 Diag(DIE->getLocStart(), diag::ext_designated_init) 2602 << DIE->getSourceRange(); 2603 2604 return DIE; 2605 } 2606 2607 //===----------------------------------------------------------------------===// 2608 // Initialization entity 2609 //===----------------------------------------------------------------------===// 2610 2611 InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index, 2612 const InitializedEntity &Parent) 2613 : Parent(&Parent), Index(Index) 2614 { 2615 if (const ArrayType *AT = Context.getAsArrayType(Parent.getType())) { 2616 Kind = EK_ArrayElement; 2617 Type = AT->getElementType(); 2618 } else if (const VectorType *VT = Parent.getType()->getAs<VectorType>()) { 2619 Kind = EK_VectorElement; 2620 Type = VT->getElementType(); 2621 } else { 2622 const ComplexType *CT = Parent.getType()->getAs<ComplexType>(); 2623 assert(CT && "Unexpected type"); 2624 Kind = EK_ComplexElement; 2625 Type = CT->getElementType(); 2626 } 2627 } 2628 2629 InitializedEntity 2630 InitializedEntity::InitializeBase(ASTContext &Context, 2631 const CXXBaseSpecifier *Base, 2632 bool IsInheritedVirtualBase) { 2633 InitializedEntity Result; 2634 Result.Kind = EK_Base; 2635 Result.Parent = nullptr; 2636 Result.Base = reinterpret_cast<uintptr_t>(Base); 2637 if (IsInheritedVirtualBase) 2638 Result.Base |= 0x01; 2639 2640 Result.Type = Base->getType(); 2641 return Result; 2642 } 2643 2644 DeclarationName InitializedEntity::getName() const { 2645 switch (getKind()) { 2646 case EK_Parameter: 2647 case EK_Parameter_CF_Audited: { 2648 ParmVarDecl *D = reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1); 2649 return (D ? D->getDeclName() : DeclarationName()); 2650 } 2651 2652 case EK_Variable: 2653 case EK_Member: 2654 return VariableOrMember->getDeclName(); 2655 2656 case EK_LambdaCapture: 2657 return DeclarationName(Capture.VarID); 2658 2659 case EK_Result: 2660 case EK_Exception: 2661 case EK_New: 2662 case EK_Temporary: 2663 case EK_Base: 2664 case EK_Delegating: 2665 case EK_ArrayElement: 2666 case EK_VectorElement: 2667 case EK_ComplexElement: 2668 case EK_BlockElement: 2669 case EK_CompoundLiteralInit: 2670 case EK_RelatedResult: 2671 return DeclarationName(); 2672 } 2673 2674 llvm_unreachable("Invalid EntityKind!"); 2675 } 2676 2677 DeclaratorDecl *InitializedEntity::getDecl() const { 2678 switch (getKind()) { 2679 case EK_Variable: 2680 case EK_Member: 2681 return VariableOrMember; 2682 2683 case EK_Parameter: 2684 case EK_Parameter_CF_Audited: 2685 return reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1); 2686 2687 case EK_Result: 2688 case EK_Exception: 2689 case EK_New: 2690 case EK_Temporary: 2691 case EK_Base: 2692 case EK_Delegating: 2693 case EK_ArrayElement: 2694 case EK_VectorElement: 2695 case EK_ComplexElement: 2696 case EK_BlockElement: 2697 case EK_LambdaCapture: 2698 case EK_CompoundLiteralInit: 2699 case EK_RelatedResult: 2700 return nullptr; 2701 } 2702 2703 llvm_unreachable("Invalid EntityKind!"); 2704 } 2705 2706 bool InitializedEntity::allowsNRVO() const { 2707 switch (getKind()) { 2708 case EK_Result: 2709 case EK_Exception: 2710 return LocAndNRVO.NRVO; 2711 2712 case EK_Variable: 2713 case EK_Parameter: 2714 case EK_Parameter_CF_Audited: 2715 case EK_Member: 2716 case EK_New: 2717 case EK_Temporary: 2718 case EK_CompoundLiteralInit: 2719 case EK_Base: 2720 case EK_Delegating: 2721 case EK_ArrayElement: 2722 case EK_VectorElement: 2723 case EK_ComplexElement: 2724 case EK_BlockElement: 2725 case EK_LambdaCapture: 2726 case EK_RelatedResult: 2727 break; 2728 } 2729 2730 return false; 2731 } 2732 2733 unsigned InitializedEntity::dumpImpl(raw_ostream &OS) const { 2734 assert(getParent() != this); 2735 unsigned Depth = getParent() ? getParent()->dumpImpl(OS) : 0; 2736 for (unsigned I = 0; I != Depth; ++I) 2737 OS << "`-"; 2738 2739 switch (getKind()) { 2740 case EK_Variable: OS << "Variable"; break; 2741 case EK_Parameter: OS << "Parameter"; break; 2742 case EK_Parameter_CF_Audited: OS << "CF audited function Parameter"; 2743 break; 2744 case EK_Result: OS << "Result"; break; 2745 case EK_Exception: OS << "Exception"; break; 2746 case EK_Member: OS << "Member"; break; 2747 case EK_New: OS << "New"; break; 2748 case EK_Temporary: OS << "Temporary"; break; 2749 case EK_CompoundLiteralInit: OS << "CompoundLiteral";break; 2750 case EK_RelatedResult: OS << "RelatedResult"; break; 2751 case EK_Base: OS << "Base"; break; 2752 case EK_Delegating: OS << "Delegating"; break; 2753 case EK_ArrayElement: OS << "ArrayElement " << Index; break; 2754 case EK_VectorElement: OS << "VectorElement " << Index; break; 2755 case EK_ComplexElement: OS << "ComplexElement " << Index; break; 2756 case EK_BlockElement: OS << "Block"; break; 2757 case EK_LambdaCapture: 2758 OS << "LambdaCapture "; 2759 OS << DeclarationName(Capture.VarID); 2760 break; 2761 } 2762 2763 if (Decl *D = getDecl()) { 2764 OS << " "; 2765 cast<NamedDecl>(D)->printQualifiedName(OS); 2766 } 2767 2768 OS << " '" << getType().getAsString() << "'\n"; 2769 2770 return Depth + 1; 2771 } 2772 2773 void InitializedEntity::dump() const { 2774 dumpImpl(llvm::errs()); 2775 } 2776 2777 //===----------------------------------------------------------------------===// 2778 // Initialization sequence 2779 //===----------------------------------------------------------------------===// 2780 2781 void InitializationSequence::Step::Destroy() { 2782 switch (Kind) { 2783 case SK_ResolveAddressOfOverloadedFunction: 2784 case SK_CastDerivedToBaseRValue: 2785 case SK_CastDerivedToBaseXValue: 2786 case SK_CastDerivedToBaseLValue: 2787 case SK_BindReference: 2788 case SK_BindReferenceToTemporary: 2789 case SK_ExtraneousCopyToTemporary: 2790 case SK_UserConversion: 2791 case SK_QualificationConversionRValue: 2792 case SK_QualificationConversionXValue: 2793 case SK_QualificationConversionLValue: 2794 case SK_AtomicConversion: 2795 case SK_LValueToRValue: 2796 case SK_ListInitialization: 2797 case SK_UnwrapInitList: 2798 case SK_RewrapInitList: 2799 case SK_ConstructorInitialization: 2800 case SK_ConstructorInitializationFromList: 2801 case SK_ZeroInitialization: 2802 case SK_CAssignment: 2803 case SK_StringInit: 2804 case SK_ObjCObjectConversion: 2805 case SK_ArrayInit: 2806 case SK_ParenthesizedArrayInit: 2807 case SK_PassByIndirectCopyRestore: 2808 case SK_PassByIndirectRestore: 2809 case SK_ProduceObjCObject: 2810 case SK_StdInitializerList: 2811 case SK_StdInitializerListConstructorCall: 2812 case SK_OCLSamplerInit: 2813 case SK_OCLZeroEvent: 2814 break; 2815 2816 case SK_ConversionSequence: 2817 case SK_ConversionSequenceNoNarrowing: 2818 delete ICS; 2819 } 2820 } 2821 2822 bool InitializationSequence::isDirectReferenceBinding() const { 2823 return !Steps.empty() && Steps.back().Kind == SK_BindReference; 2824 } 2825 2826 bool InitializationSequence::isAmbiguous() const { 2827 if (!Failed()) 2828 return false; 2829 2830 switch (getFailureKind()) { 2831 case FK_TooManyInitsForReference: 2832 case FK_ArrayNeedsInitList: 2833 case FK_ArrayNeedsInitListOrStringLiteral: 2834 case FK_ArrayNeedsInitListOrWideStringLiteral: 2835 case FK_NarrowStringIntoWideCharArray: 2836 case FK_WideStringIntoCharArray: 2837 case FK_IncompatWideStringIntoWideChar: 2838 case FK_AddressOfOverloadFailed: // FIXME: Could do better 2839 case FK_NonConstLValueReferenceBindingToTemporary: 2840 case FK_NonConstLValueReferenceBindingToUnrelated: 2841 case FK_RValueReferenceBindingToLValue: 2842 case FK_ReferenceInitDropsQualifiers: 2843 case FK_ReferenceInitFailed: 2844 case FK_ConversionFailed: 2845 case FK_ConversionFromPropertyFailed: 2846 case FK_TooManyInitsForScalar: 2847 case FK_ReferenceBindingToInitList: 2848 case FK_InitListBadDestinationType: 2849 case FK_DefaultInitOfConst: 2850 case FK_Incomplete: 2851 case FK_ArrayTypeMismatch: 2852 case FK_NonConstantArrayInit: 2853 case FK_ListInitializationFailed: 2854 case FK_VariableLengthArrayHasInitializer: 2855 case FK_PlaceholderType: 2856 case FK_ExplicitConstructor: 2857 return false; 2858 2859 case FK_ReferenceInitOverloadFailed: 2860 case FK_UserConversionOverloadFailed: 2861 case FK_ConstructorOverloadFailed: 2862 case FK_ListConstructorOverloadFailed: 2863 return FailedOverloadResult == OR_Ambiguous; 2864 } 2865 2866 llvm_unreachable("Invalid EntityKind!"); 2867 } 2868 2869 bool InitializationSequence::isConstructorInitialization() const { 2870 return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization; 2871 } 2872 2873 void 2874 InitializationSequence 2875 ::AddAddressOverloadResolutionStep(FunctionDecl *Function, 2876 DeclAccessPair Found, 2877 bool HadMultipleCandidates) { 2878 Step S; 2879 S.Kind = SK_ResolveAddressOfOverloadedFunction; 2880 S.Type = Function->getType(); 2881 S.Function.HadMultipleCandidates = HadMultipleCandidates; 2882 S.Function.Function = Function; 2883 S.Function.FoundDecl = Found; 2884 Steps.push_back(S); 2885 } 2886 2887 void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType, 2888 ExprValueKind VK) { 2889 Step S; 2890 switch (VK) { 2891 case VK_RValue: S.Kind = SK_CastDerivedToBaseRValue; break; 2892 case VK_XValue: S.Kind = SK_CastDerivedToBaseXValue; break; 2893 case VK_LValue: S.Kind = SK_CastDerivedToBaseLValue; break; 2894 } 2895 S.Type = BaseType; 2896 Steps.push_back(S); 2897 } 2898 2899 void InitializationSequence::AddReferenceBindingStep(QualType T, 2900 bool BindingTemporary) { 2901 Step S; 2902 S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference; 2903 S.Type = T; 2904 Steps.push_back(S); 2905 } 2906 2907 void InitializationSequence::AddExtraneousCopyToTemporary(QualType T) { 2908 Step S; 2909 S.Kind = SK_ExtraneousCopyToTemporary; 2910 S.Type = T; 2911 Steps.push_back(S); 2912 } 2913 2914 void 2915 InitializationSequence::AddUserConversionStep(FunctionDecl *Function, 2916 DeclAccessPair FoundDecl, 2917 QualType T, 2918 bool HadMultipleCandidates) { 2919 Step S; 2920 S.Kind = SK_UserConversion; 2921 S.Type = T; 2922 S.Function.HadMultipleCandidates = HadMultipleCandidates; 2923 S.Function.Function = Function; 2924 S.Function.FoundDecl = FoundDecl; 2925 Steps.push_back(S); 2926 } 2927 2928 void InitializationSequence::AddQualificationConversionStep(QualType Ty, 2929 ExprValueKind VK) { 2930 Step S; 2931 S.Kind = SK_QualificationConversionRValue; // work around a gcc warning 2932 switch (VK) { 2933 case VK_RValue: 2934 S.Kind = SK_QualificationConversionRValue; 2935 break; 2936 case VK_XValue: 2937 S.Kind = SK_QualificationConversionXValue; 2938 break; 2939 case VK_LValue: 2940 S.Kind = SK_QualificationConversionLValue; 2941 break; 2942 } 2943 S.Type = Ty; 2944 Steps.push_back(S); 2945 } 2946 2947 void InitializationSequence::AddAtomicConversionStep(QualType Ty) { 2948 Step S; 2949 S.Kind = SK_AtomicConversion; 2950 S.Type = Ty; 2951 Steps.push_back(S); 2952 } 2953 2954 void InitializationSequence::AddLValueToRValueStep(QualType Ty) { 2955 assert(!Ty.hasQualifiers() && "rvalues may not have qualifiers"); 2956 2957 Step S; 2958 S.Kind = SK_LValueToRValue; 2959 S.Type = Ty; 2960 Steps.push_back(S); 2961 } 2962 2963 void InitializationSequence::AddConversionSequenceStep( 2964 const ImplicitConversionSequence &ICS, QualType T, 2965 bool TopLevelOfInitList) { 2966 Step S; 2967 S.Kind = TopLevelOfInitList ? SK_ConversionSequenceNoNarrowing 2968 : SK_ConversionSequence; 2969 S.Type = T; 2970 S.ICS = new ImplicitConversionSequence(ICS); 2971 Steps.push_back(S); 2972 } 2973 2974 void InitializationSequence::AddListInitializationStep(QualType T) { 2975 Step S; 2976 S.Kind = SK_ListInitialization; 2977 S.Type = T; 2978 Steps.push_back(S); 2979 } 2980 2981 void 2982 InitializationSequence 2983 ::AddConstructorInitializationStep(CXXConstructorDecl *Constructor, 2984 AccessSpecifier Access, 2985 QualType T, 2986 bool HadMultipleCandidates, 2987 bool FromInitList, bool AsInitList) { 2988 Step S; 2989 S.Kind = FromInitList ? AsInitList ? SK_StdInitializerListConstructorCall 2990 : SK_ConstructorInitializationFromList 2991 : SK_ConstructorInitialization; 2992 S.Type = T; 2993 S.Function.HadMultipleCandidates = HadMultipleCandidates; 2994 S.Function.Function = Constructor; 2995 S.Function.FoundDecl = DeclAccessPair::make(Constructor, Access); 2996 Steps.push_back(S); 2997 } 2998 2999 void InitializationSequence::AddZeroInitializationStep(QualType T) { 3000 Step S; 3001 S.Kind = SK_ZeroInitialization; 3002 S.Type = T; 3003 Steps.push_back(S); 3004 } 3005 3006 void InitializationSequence::AddCAssignmentStep(QualType T) { 3007 Step S; 3008 S.Kind = SK_CAssignment; 3009 S.Type = T; 3010 Steps.push_back(S); 3011 } 3012 3013 void InitializationSequence::AddStringInitStep(QualType T) { 3014 Step S; 3015 S.Kind = SK_StringInit; 3016 S.Type = T; 3017 Steps.push_back(S); 3018 } 3019 3020 void InitializationSequence::AddObjCObjectConversionStep(QualType T) { 3021 Step S; 3022 S.Kind = SK_ObjCObjectConversion; 3023 S.Type = T; 3024 Steps.push_back(S); 3025 } 3026 3027 void InitializationSequence::AddArrayInitStep(QualType T) { 3028 Step S; 3029 S.Kind = SK_ArrayInit; 3030 S.Type = T; 3031 Steps.push_back(S); 3032 } 3033 3034 void InitializationSequence::AddParenthesizedArrayInitStep(QualType T) { 3035 Step S; 3036 S.Kind = SK_ParenthesizedArrayInit; 3037 S.Type = T; 3038 Steps.push_back(S); 3039 } 3040 3041 void InitializationSequence::AddPassByIndirectCopyRestoreStep(QualType type, 3042 bool shouldCopy) { 3043 Step s; 3044 s.Kind = (shouldCopy ? SK_PassByIndirectCopyRestore 3045 : SK_PassByIndirectRestore); 3046 s.Type = type; 3047 Steps.push_back(s); 3048 } 3049 3050 void InitializationSequence::AddProduceObjCObjectStep(QualType T) { 3051 Step S; 3052 S.Kind = SK_ProduceObjCObject; 3053 S.Type = T; 3054 Steps.push_back(S); 3055 } 3056 3057 void InitializationSequence::AddStdInitializerListConstructionStep(QualType T) { 3058 Step S; 3059 S.Kind = SK_StdInitializerList; 3060 S.Type = T; 3061 Steps.push_back(S); 3062 } 3063 3064 void InitializationSequence::AddOCLSamplerInitStep(QualType T) { 3065 Step S; 3066 S.Kind = SK_OCLSamplerInit; 3067 S.Type = T; 3068 Steps.push_back(S); 3069 } 3070 3071 void InitializationSequence::AddOCLZeroEventStep(QualType T) { 3072 Step S; 3073 S.Kind = SK_OCLZeroEvent; 3074 S.Type = T; 3075 Steps.push_back(S); 3076 } 3077 3078 void InitializationSequence::RewrapReferenceInitList(QualType T, 3079 InitListExpr *Syntactic) { 3080 assert(Syntactic->getNumInits() == 1 && 3081 "Can only rewrap trivial init lists."); 3082 Step S; 3083 S.Kind = SK_UnwrapInitList; 3084 S.Type = Syntactic->getInit(0)->getType(); 3085 Steps.insert(Steps.begin(), S); 3086 3087 S.Kind = SK_RewrapInitList; 3088 S.Type = T; 3089 S.WrappingSyntacticList = Syntactic; 3090 Steps.push_back(S); 3091 } 3092 3093 void InitializationSequence::SetOverloadFailure(FailureKind Failure, 3094 OverloadingResult Result) { 3095 setSequenceKind(FailedSequence); 3096 this->Failure = Failure; 3097 this->FailedOverloadResult = Result; 3098 } 3099 3100 //===----------------------------------------------------------------------===// 3101 // Attempt initialization 3102 //===----------------------------------------------------------------------===// 3103 3104 static void MaybeProduceObjCObject(Sema &S, 3105 InitializationSequence &Sequence, 3106 const InitializedEntity &Entity) { 3107 if (!S.getLangOpts().ObjCAutoRefCount) return; 3108 3109 /// When initializing a parameter, produce the value if it's marked 3110 /// __attribute__((ns_consumed)). 3111 if (Entity.isParameterKind()) { 3112 if (!Entity.isParameterConsumed()) 3113 return; 3114 3115 assert(Entity.getType()->isObjCRetainableType() && 3116 "consuming an object of unretainable type?"); 3117 Sequence.AddProduceObjCObjectStep(Entity.getType()); 3118 3119 /// When initializing a return value, if the return type is a 3120 /// retainable type, then returns need to immediately retain the 3121 /// object. If an autorelease is required, it will be done at the 3122 /// last instant. 3123 } else if (Entity.getKind() == InitializedEntity::EK_Result) { 3124 if (!Entity.getType()->isObjCRetainableType()) 3125 return; 3126 3127 Sequence.AddProduceObjCObjectStep(Entity.getType()); 3128 } 3129 } 3130 3131 static void TryListInitialization(Sema &S, 3132 const InitializedEntity &Entity, 3133 const InitializationKind &Kind, 3134 InitListExpr *InitList, 3135 InitializationSequence &Sequence); 3136 3137 /// \brief When initializing from init list via constructor, handle 3138 /// initialization of an object of type std::initializer_list<T>. 3139 /// 3140 /// \return true if we have handled initialization of an object of type 3141 /// std::initializer_list<T>, false otherwise. 3142 static bool TryInitializerListConstruction(Sema &S, 3143 InitListExpr *List, 3144 QualType DestType, 3145 InitializationSequence &Sequence) { 3146 QualType E; 3147 if (!S.isStdInitializerList(DestType, &E)) 3148 return false; 3149 3150 if (S.RequireCompleteType(List->getExprLoc(), E, 0)) { 3151 Sequence.setIncompleteTypeFailure(E); 3152 return true; 3153 } 3154 3155 // Try initializing a temporary array from the init list. 3156 QualType ArrayType = S.Context.getConstantArrayType( 3157 E.withConst(), llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()), 3158 List->getNumInits()), 3159 clang::ArrayType::Normal, 0); 3160 InitializedEntity HiddenArray = 3161 InitializedEntity::InitializeTemporary(ArrayType); 3162 InitializationKind Kind = 3163 InitializationKind::CreateDirectList(List->getExprLoc()); 3164 TryListInitialization(S, HiddenArray, Kind, List, Sequence); 3165 if (Sequence) 3166 Sequence.AddStdInitializerListConstructionStep(DestType); 3167 return true; 3168 } 3169 3170 static OverloadingResult 3171 ResolveConstructorOverload(Sema &S, SourceLocation DeclLoc, 3172 MultiExprArg Args, 3173 OverloadCandidateSet &CandidateSet, 3174 DeclContext::lookup_result Ctors, 3175 OverloadCandidateSet::iterator &Best, 3176 bool CopyInitializing, bool AllowExplicit, 3177 bool OnlyListConstructors, bool IsListInit) { 3178 CandidateSet.clear(); 3179 3180 for (NamedDecl *D : Ctors) { 3181 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 3182 bool SuppressUserConversions = false; 3183 3184 // Find the constructor (which may be a template). 3185 CXXConstructorDecl *Constructor = nullptr; 3186 FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D); 3187 if (ConstructorTmpl) 3188 Constructor = cast<CXXConstructorDecl>( 3189 ConstructorTmpl->getTemplatedDecl()); 3190 else { 3191 Constructor = cast<CXXConstructorDecl>(D); 3192 3193 // C++11 [over.best.ics]p4: 3194 // ... and the constructor or user-defined conversion function is a 3195 // candidate by 3196 // - 13.3.1.3, when the argument is the temporary in the second step 3197 // of a class copy-initialization, or 3198 // - 13.3.1.4, 13.3.1.5, or 13.3.1.6 (in all cases), 3199 // user-defined conversion sequences are not considered. 3200 // FIXME: This breaks backward compatibility, e.g. PR12117. As a 3201 // temporary fix, let's re-instate the third bullet above until 3202 // there is a resolution in the standard, i.e., 3203 // - 13.3.1.7 when the initializer list has exactly one element that is 3204 // itself an initializer list and a conversion to some class X or 3205 // reference to (possibly cv-qualified) X is considered for the first 3206 // parameter of a constructor of X. 3207 if ((CopyInitializing || 3208 (IsListInit && Args.size() == 1 && isa<InitListExpr>(Args[0]))) && 3209 Constructor->isCopyOrMoveConstructor()) 3210 SuppressUserConversions = true; 3211 } 3212 3213 if (!Constructor->isInvalidDecl() && 3214 (AllowExplicit || !Constructor->isExplicit()) && 3215 (!OnlyListConstructors || S.isInitListConstructor(Constructor))) { 3216 if (ConstructorTmpl) 3217 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3218 /*ExplicitArgs*/ nullptr, Args, 3219 CandidateSet, SuppressUserConversions); 3220 else { 3221 // C++ [over.match.copy]p1: 3222 // - When initializing a temporary to be bound to the first parameter 3223 // of a constructor that takes a reference to possibly cv-qualified 3224 // T as its first argument, called with a single argument in the 3225 // context of direct-initialization, explicit conversion functions 3226 // are also considered. 3227 bool AllowExplicitConv = AllowExplicit && !CopyInitializing && 3228 Args.size() == 1 && 3229 Constructor->isCopyOrMoveConstructor(); 3230 S.AddOverloadCandidate(Constructor, FoundDecl, Args, CandidateSet, 3231 SuppressUserConversions, 3232 /*PartialOverloading=*/false, 3233 /*AllowExplicit=*/AllowExplicitConv); 3234 } 3235 } 3236 } 3237 3238 // Perform overload resolution and return the result. 3239 return CandidateSet.BestViableFunction(S, DeclLoc, Best); 3240 } 3241 3242 /// \brief Attempt initialization by constructor (C++ [dcl.init]), which 3243 /// enumerates the constructors of the initialized entity and performs overload 3244 /// resolution to select the best. 3245 /// \param IsListInit Is this list-initialization? 3246 /// \param IsInitListCopy Is this non-list-initialization resulting from a 3247 /// list-initialization from {x} where x is the same 3248 /// type as the entity? 3249 static void TryConstructorInitialization(Sema &S, 3250 const InitializedEntity &Entity, 3251 const InitializationKind &Kind, 3252 MultiExprArg Args, QualType DestType, 3253 InitializationSequence &Sequence, 3254 bool IsListInit = false, 3255 bool IsInitListCopy = false) { 3256 assert((!IsListInit || (Args.size() == 1 && isa<InitListExpr>(Args[0]))) && 3257 "IsListInit must come with a single initializer list argument."); 3258 3259 // The type we're constructing needs to be complete. 3260 if (S.RequireCompleteType(Kind.getLocation(), DestType, 0)) { 3261 Sequence.setIncompleteTypeFailure(DestType); 3262 return; 3263 } 3264 3265 const RecordType *DestRecordType = DestType->getAs<RecordType>(); 3266 assert(DestRecordType && "Constructor initialization requires record type"); 3267 CXXRecordDecl *DestRecordDecl 3268 = cast<CXXRecordDecl>(DestRecordType->getDecl()); 3269 3270 // Build the candidate set directly in the initialization sequence 3271 // structure, so that it will persist if we fail. 3272 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 3273 3274 // Determine whether we are allowed to call explicit constructors or 3275 // explicit conversion operators. 3276 bool AllowExplicit = Kind.AllowExplicit() || IsListInit; 3277 bool CopyInitialization = Kind.getKind() == InitializationKind::IK_Copy; 3278 3279 // - Otherwise, if T is a class type, constructors are considered. The 3280 // applicable constructors are enumerated, and the best one is chosen 3281 // through overload resolution. 3282 DeclContext::lookup_result Ctors = S.LookupConstructors(DestRecordDecl); 3283 3284 OverloadingResult Result = OR_No_Viable_Function; 3285 OverloadCandidateSet::iterator Best; 3286 bool AsInitializerList = false; 3287 3288 // C++11 [over.match.list]p1, per DR1467: 3289 // When objects of non-aggregate type T are list-initialized, such that 3290 // 8.5.4 [dcl.init.list] specifies that overload resolution is performed 3291 // according to the rules in this section, overload resolution selects 3292 // the constructor in two phases: 3293 // 3294 // - Initially, the candidate functions are the initializer-list 3295 // constructors of the class T and the argument list consists of the 3296 // initializer list as a single argument. 3297 if (IsListInit) { 3298 InitListExpr *ILE = cast<InitListExpr>(Args[0]); 3299 AsInitializerList = true; 3300 3301 // If the initializer list has no elements and T has a default constructor, 3302 // the first phase is omitted. 3303 if (ILE->getNumInits() != 0 || !DestRecordDecl->hasDefaultConstructor()) 3304 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args, 3305 CandidateSet, Ctors, Best, 3306 CopyInitialization, AllowExplicit, 3307 /*OnlyListConstructor=*/true, 3308 IsListInit); 3309 3310 // Time to unwrap the init list. 3311 Args = MultiExprArg(ILE->getInits(), ILE->getNumInits()); 3312 } 3313 3314 // C++11 [over.match.list]p1: 3315 // - If no viable initializer-list constructor is found, overload resolution 3316 // is performed again, where the candidate functions are all the 3317 // constructors of the class T and the argument list consists of the 3318 // elements of the initializer list. 3319 if (Result == OR_No_Viable_Function) { 3320 AsInitializerList = false; 3321 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args, 3322 CandidateSet, Ctors, Best, 3323 CopyInitialization, AllowExplicit, 3324 /*OnlyListConstructors=*/false, 3325 IsListInit); 3326 } 3327 if (Result) { 3328 Sequence.SetOverloadFailure(IsListInit ? 3329 InitializationSequence::FK_ListConstructorOverloadFailed : 3330 InitializationSequence::FK_ConstructorOverloadFailed, 3331 Result); 3332 return; 3333 } 3334 3335 // C++11 [dcl.init]p6: 3336 // If a program calls for the default initialization of an object 3337 // of a const-qualified type T, T shall be a class type with a 3338 // user-provided default constructor. 3339 if (Kind.getKind() == InitializationKind::IK_Default && 3340 Entity.getType().isConstQualified() && 3341 !cast<CXXConstructorDecl>(Best->Function)->isUserProvided()) { 3342 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst); 3343 return; 3344 } 3345 3346 // C++11 [over.match.list]p1: 3347 // In copy-list-initialization, if an explicit constructor is chosen, the 3348 // initializer is ill-formed. 3349 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function); 3350 if (IsListInit && !Kind.AllowExplicit() && CtorDecl->isExplicit()) { 3351 Sequence.SetFailed(InitializationSequence::FK_ExplicitConstructor); 3352 return; 3353 } 3354 3355 // Add the constructor initialization step. Any cv-qualification conversion is 3356 // subsumed by the initialization. 3357 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3358 Sequence.AddConstructorInitializationStep( 3359 CtorDecl, Best->FoundDecl.getAccess(), DestType, HadMultipleCandidates, 3360 IsListInit | IsInitListCopy, AsInitializerList); 3361 } 3362 3363 static bool 3364 ResolveOverloadedFunctionForReferenceBinding(Sema &S, 3365 Expr *Initializer, 3366 QualType &SourceType, 3367 QualType &UnqualifiedSourceType, 3368 QualType UnqualifiedTargetType, 3369 InitializationSequence &Sequence) { 3370 if (S.Context.getCanonicalType(UnqualifiedSourceType) == 3371 S.Context.OverloadTy) { 3372 DeclAccessPair Found; 3373 bool HadMultipleCandidates = false; 3374 if (FunctionDecl *Fn 3375 = S.ResolveAddressOfOverloadedFunction(Initializer, 3376 UnqualifiedTargetType, 3377 false, Found, 3378 &HadMultipleCandidates)) { 3379 Sequence.AddAddressOverloadResolutionStep(Fn, Found, 3380 HadMultipleCandidates); 3381 SourceType = Fn->getType(); 3382 UnqualifiedSourceType = SourceType.getUnqualifiedType(); 3383 } else if (!UnqualifiedTargetType->isRecordType()) { 3384 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 3385 return true; 3386 } 3387 } 3388 return false; 3389 } 3390 3391 static void TryReferenceInitializationCore(Sema &S, 3392 const InitializedEntity &Entity, 3393 const InitializationKind &Kind, 3394 Expr *Initializer, 3395 QualType cv1T1, QualType T1, 3396 Qualifiers T1Quals, 3397 QualType cv2T2, QualType T2, 3398 Qualifiers T2Quals, 3399 InitializationSequence &Sequence); 3400 3401 static void TryValueInitialization(Sema &S, 3402 const InitializedEntity &Entity, 3403 const InitializationKind &Kind, 3404 InitializationSequence &Sequence, 3405 InitListExpr *InitList = nullptr); 3406 3407 /// \brief Attempt list initialization of a reference. 3408 static void TryReferenceListInitialization(Sema &S, 3409 const InitializedEntity &Entity, 3410 const InitializationKind &Kind, 3411 InitListExpr *InitList, 3412 InitializationSequence &Sequence) { 3413 // First, catch C++03 where this isn't possible. 3414 if (!S.getLangOpts().CPlusPlus11) { 3415 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList); 3416 return; 3417 } 3418 3419 QualType DestType = Entity.getType(); 3420 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 3421 Qualifiers T1Quals; 3422 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals); 3423 3424 // Reference initialization via an initializer list works thus: 3425 // If the initializer list consists of a single element that is 3426 // reference-related to the referenced type, bind directly to that element 3427 // (possibly creating temporaries). 3428 // Otherwise, initialize a temporary with the initializer list and 3429 // bind to that. 3430 if (InitList->getNumInits() == 1) { 3431 Expr *Initializer = InitList->getInit(0); 3432 QualType cv2T2 = Initializer->getType(); 3433 Qualifiers T2Quals; 3434 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals); 3435 3436 // If this fails, creating a temporary wouldn't work either. 3437 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2, 3438 T1, Sequence)) 3439 return; 3440 3441 SourceLocation DeclLoc = Initializer->getLocStart(); 3442 bool dummy1, dummy2, dummy3; 3443 Sema::ReferenceCompareResult RefRelationship 3444 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, dummy1, 3445 dummy2, dummy3); 3446 if (RefRelationship >= Sema::Ref_Related) { 3447 // Try to bind the reference here. 3448 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1, 3449 T1Quals, cv2T2, T2, T2Quals, Sequence); 3450 if (Sequence) 3451 Sequence.RewrapReferenceInitList(cv1T1, InitList); 3452 return; 3453 } 3454 3455 // Update the initializer if we've resolved an overloaded function. 3456 if (Sequence.step_begin() != Sequence.step_end()) 3457 Sequence.RewrapReferenceInitList(cv1T1, InitList); 3458 } 3459 3460 // Not reference-related. Create a temporary and bind to that. 3461 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1); 3462 3463 TryListInitialization(S, TempEntity, Kind, InitList, Sequence); 3464 if (Sequence) { 3465 if (DestType->isRValueReferenceType() || 3466 (T1Quals.hasConst() && !T1Quals.hasVolatile())) 3467 Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true); 3468 else 3469 Sequence.SetFailed( 3470 InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary); 3471 } 3472 } 3473 3474 /// \brief Attempt list initialization (C++0x [dcl.init.list]) 3475 static void TryListInitialization(Sema &S, 3476 const InitializedEntity &Entity, 3477 const InitializationKind &Kind, 3478 InitListExpr *InitList, 3479 InitializationSequence &Sequence) { 3480 QualType DestType = Entity.getType(); 3481 3482 // C++ doesn't allow scalar initialization with more than one argument. 3483 // But C99 complex numbers are scalars and it makes sense there. 3484 if (S.getLangOpts().CPlusPlus && DestType->isScalarType() && 3485 !DestType->isAnyComplexType() && InitList->getNumInits() > 1) { 3486 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar); 3487 return; 3488 } 3489 if (DestType->isReferenceType()) { 3490 TryReferenceListInitialization(S, Entity, Kind, InitList, Sequence); 3491 return; 3492 } 3493 3494 if (DestType->isRecordType() && 3495 S.RequireCompleteType(InitList->getLocStart(), DestType, 0)) { 3496 Sequence.setIncompleteTypeFailure(DestType); 3497 return; 3498 } 3499 3500 // C++11 [dcl.init.list]p3, per DR1467: 3501 // - If T is a class type and the initializer list has a single element of 3502 // type cv U, where U is T or a class derived from T, the object is 3503 // initialized from that element (by copy-initialization for 3504 // copy-list-initialization, or by direct-initialization for 3505 // direct-list-initialization). 3506 // - Otherwise, if T is a character array and the initializer list has a 3507 // single element that is an appropriately-typed string literal 3508 // (8.5.2 [dcl.init.string]), initialization is performed as described 3509 // in that section. 3510 // - Otherwise, if T is an aggregate, [...] (continue below). 3511 if (S.getLangOpts().CPlusPlus11 && InitList->getNumInits() == 1) { 3512 if (DestType->isRecordType()) { 3513 QualType InitType = InitList->getInit(0)->getType(); 3514 if (S.Context.hasSameUnqualifiedType(InitType, DestType) || 3515 S.IsDerivedFrom(InitType, DestType)) { 3516 Expr *InitAsExpr = InitList->getInit(0); 3517 TryConstructorInitialization(S, Entity, Kind, InitAsExpr, DestType, 3518 Sequence, /*InitListSyntax*/ false, 3519 /*IsInitListCopy*/ true); 3520 return; 3521 } 3522 } 3523 if (const ArrayType *DestAT = S.Context.getAsArrayType(DestType)) { 3524 Expr *SubInit[1] = {InitList->getInit(0)}; 3525 if (!isa<VariableArrayType>(DestAT) && 3526 IsStringInit(SubInit[0], DestAT, S.Context) == SIF_None) { 3527 InitializationKind SubKind = 3528 Kind.getKind() == InitializationKind::IK_DirectList 3529 ? InitializationKind::CreateDirect(Kind.getLocation(), 3530 InitList->getLBraceLoc(), 3531 InitList->getRBraceLoc()) 3532 : Kind; 3533 Sequence.InitializeFrom(S, Entity, SubKind, SubInit, 3534 /*TopLevelOfInitList*/ true); 3535 3536 // TryStringLiteralInitialization() (in InitializeFrom()) will fail if 3537 // the element is not an appropriately-typed string literal, in which 3538 // case we should proceed as in C++11 (below). 3539 if (Sequence) { 3540 Sequence.RewrapReferenceInitList(Entity.getType(), InitList); 3541 return; 3542 } 3543 } 3544 } 3545 } 3546 3547 // C++11 [dcl.init.list]p3: 3548 // - If T is an aggregate, aggregate initialization is performed. 3549 if (DestType->isRecordType() && !DestType->isAggregateType()) { 3550 if (S.getLangOpts().CPlusPlus11) { 3551 // - Otherwise, if the initializer list has no elements and T is a 3552 // class type with a default constructor, the object is 3553 // value-initialized. 3554 if (InitList->getNumInits() == 0) { 3555 CXXRecordDecl *RD = DestType->getAsCXXRecordDecl(); 3556 if (RD->hasDefaultConstructor()) { 3557 TryValueInitialization(S, Entity, Kind, Sequence, InitList); 3558 return; 3559 } 3560 } 3561 3562 // - Otherwise, if T is a specialization of std::initializer_list<E>, 3563 // an initializer_list object constructed [...] 3564 if (TryInitializerListConstruction(S, InitList, DestType, Sequence)) 3565 return; 3566 3567 // - Otherwise, if T is a class type, constructors are considered. 3568 Expr *InitListAsExpr = InitList; 3569 TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType, 3570 Sequence, /*InitListSyntax*/ true); 3571 } else 3572 Sequence.SetFailed(InitializationSequence::FK_InitListBadDestinationType); 3573 return; 3574 } 3575 3576 if (S.getLangOpts().CPlusPlus && !DestType->isAggregateType() && 3577 InitList->getNumInits() == 1 && 3578 InitList->getInit(0)->getType()->isRecordType()) { 3579 // - Otherwise, if the initializer list has a single element of type E 3580 // [...references are handled above...], the object or reference is 3581 // initialized from that element (by copy-initialization for 3582 // copy-list-initialization, or by direct-initialization for 3583 // direct-list-initialization); if a narrowing conversion is required 3584 // to convert the element to T, the program is ill-formed. 3585 // 3586 // Per core-24034, this is direct-initialization if we were performing 3587 // direct-list-initialization and copy-initialization otherwise. 3588 // We can't use InitListChecker for this, because it always performs 3589 // copy-initialization. This only matters if we might use an 'explicit' 3590 // conversion operator, so we only need to handle the cases where the source 3591 // is of record type. 3592 InitializationKind SubKind = 3593 Kind.getKind() == InitializationKind::IK_DirectList 3594 ? InitializationKind::CreateDirect(Kind.getLocation(), 3595 InitList->getLBraceLoc(), 3596 InitList->getRBraceLoc()) 3597 : Kind; 3598 Expr *SubInit[1] = { InitList->getInit(0) }; 3599 Sequence.InitializeFrom(S, Entity, SubKind, SubInit, 3600 /*TopLevelOfInitList*/true); 3601 if (Sequence) 3602 Sequence.RewrapReferenceInitList(Entity.getType(), InitList); 3603 return; 3604 } 3605 3606 InitListChecker CheckInitList(S, Entity, InitList, 3607 DestType, /*VerifyOnly=*/true); 3608 if (CheckInitList.HadError()) { 3609 Sequence.SetFailed(InitializationSequence::FK_ListInitializationFailed); 3610 return; 3611 } 3612 3613 // Add the list initialization step with the built init list. 3614 Sequence.AddListInitializationStep(DestType); 3615 } 3616 3617 /// \brief Try a reference initialization that involves calling a conversion 3618 /// function. 3619 static OverloadingResult TryRefInitWithConversionFunction(Sema &S, 3620 const InitializedEntity &Entity, 3621 const InitializationKind &Kind, 3622 Expr *Initializer, 3623 bool AllowRValues, 3624 InitializationSequence &Sequence) { 3625 QualType DestType = Entity.getType(); 3626 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 3627 QualType T1 = cv1T1.getUnqualifiedType(); 3628 QualType cv2T2 = Initializer->getType(); 3629 QualType T2 = cv2T2.getUnqualifiedType(); 3630 3631 bool DerivedToBase; 3632 bool ObjCConversion; 3633 bool ObjCLifetimeConversion; 3634 assert(!S.CompareReferenceRelationship(Initializer->getLocStart(), 3635 T1, T2, DerivedToBase, 3636 ObjCConversion, 3637 ObjCLifetimeConversion) && 3638 "Must have incompatible references when binding via conversion"); 3639 (void)DerivedToBase; 3640 (void)ObjCConversion; 3641 (void)ObjCLifetimeConversion; 3642 3643 // Build the candidate set directly in the initialization sequence 3644 // structure, so that it will persist if we fail. 3645 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 3646 CandidateSet.clear(); 3647 3648 // Determine whether we are allowed to call explicit constructors or 3649 // explicit conversion operators. 3650 bool AllowExplicit = Kind.AllowExplicit(); 3651 bool AllowExplicitConvs = Kind.allowExplicitConversionFunctionsInRefBinding(); 3652 3653 const RecordType *T1RecordType = nullptr; 3654 if (AllowRValues && (T1RecordType = T1->getAs<RecordType>()) && 3655 !S.RequireCompleteType(Kind.getLocation(), T1, 0)) { 3656 // The type we're converting to is a class type. Enumerate its constructors 3657 // to see if there is a suitable conversion. 3658 CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl()); 3659 3660 for (NamedDecl *D : S.LookupConstructors(T1RecordDecl)) { 3661 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 3662 3663 // Find the constructor (which may be a template). 3664 CXXConstructorDecl *Constructor = nullptr; 3665 FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D); 3666 if (ConstructorTmpl) 3667 Constructor = cast<CXXConstructorDecl>( 3668 ConstructorTmpl->getTemplatedDecl()); 3669 else 3670 Constructor = cast<CXXConstructorDecl>(D); 3671 3672 if (!Constructor->isInvalidDecl() && 3673 Constructor->isConvertingConstructor(AllowExplicit)) { 3674 if (ConstructorTmpl) 3675 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3676 /*ExplicitArgs*/ nullptr, 3677 Initializer, CandidateSet, 3678 /*SuppressUserConversions=*/true); 3679 else 3680 S.AddOverloadCandidate(Constructor, FoundDecl, 3681 Initializer, CandidateSet, 3682 /*SuppressUserConversions=*/true); 3683 } 3684 } 3685 } 3686 if (T1RecordType && T1RecordType->getDecl()->isInvalidDecl()) 3687 return OR_No_Viable_Function; 3688 3689 const RecordType *T2RecordType = nullptr; 3690 if ((T2RecordType = T2->getAs<RecordType>()) && 3691 !S.RequireCompleteType(Kind.getLocation(), T2, 0)) { 3692 // The type we're converting from is a class type, enumerate its conversion 3693 // functions. 3694 CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl()); 3695 3696 const auto &Conversions = T2RecordDecl->getVisibleConversionFunctions(); 3697 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) { 3698 NamedDecl *D = *I; 3699 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3700 if (isa<UsingShadowDecl>(D)) 3701 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3702 3703 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D); 3704 CXXConversionDecl *Conv; 3705 if (ConvTemplate) 3706 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3707 else 3708 Conv = cast<CXXConversionDecl>(D); 3709 3710 // If the conversion function doesn't return a reference type, 3711 // it can't be considered for this conversion unless we're allowed to 3712 // consider rvalues. 3713 // FIXME: Do we need to make sure that we only consider conversion 3714 // candidates with reference-compatible results? That might be needed to 3715 // break recursion. 3716 if ((AllowExplicitConvs || !Conv->isExplicit()) && 3717 (AllowRValues || Conv->getConversionType()->isLValueReferenceType())){ 3718 if (ConvTemplate) 3719 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), 3720 ActingDC, Initializer, 3721 DestType, CandidateSet, 3722 /*AllowObjCConversionOnExplicit=*/ 3723 false); 3724 else 3725 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, 3726 Initializer, DestType, CandidateSet, 3727 /*AllowObjCConversionOnExplicit=*/false); 3728 } 3729 } 3730 } 3731 if (T2RecordType && T2RecordType->getDecl()->isInvalidDecl()) 3732 return OR_No_Viable_Function; 3733 3734 SourceLocation DeclLoc = Initializer->getLocStart(); 3735 3736 // Perform overload resolution. If it fails, return the failed result. 3737 OverloadCandidateSet::iterator Best; 3738 if (OverloadingResult Result 3739 = CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) 3740 return Result; 3741 3742 FunctionDecl *Function = Best->Function; 3743 // This is the overload that will be used for this initialization step if we 3744 // use this initialization. Mark it as referenced. 3745 Function->setReferenced(); 3746 3747 // Compute the returned type of the conversion. 3748 if (isa<CXXConversionDecl>(Function)) 3749 T2 = Function->getReturnType(); 3750 else 3751 T2 = cv1T1; 3752 3753 // Add the user-defined conversion step. 3754 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3755 Sequence.AddUserConversionStep(Function, Best->FoundDecl, 3756 T2.getNonLValueExprType(S.Context), 3757 HadMultipleCandidates); 3758 3759 // Determine whether we need to perform derived-to-base or 3760 // cv-qualification adjustments. 3761 ExprValueKind VK = VK_RValue; 3762 if (T2->isLValueReferenceType()) 3763 VK = VK_LValue; 3764 else if (const RValueReferenceType *RRef = T2->getAs<RValueReferenceType>()) 3765 VK = RRef->getPointeeType()->isFunctionType() ? VK_LValue : VK_XValue; 3766 3767 bool NewDerivedToBase = false; 3768 bool NewObjCConversion = false; 3769 bool NewObjCLifetimeConversion = false; 3770 Sema::ReferenceCompareResult NewRefRelationship 3771 = S.CompareReferenceRelationship(DeclLoc, T1, 3772 T2.getNonLValueExprType(S.Context), 3773 NewDerivedToBase, NewObjCConversion, 3774 NewObjCLifetimeConversion); 3775 if (NewRefRelationship == Sema::Ref_Incompatible) { 3776 // If the type we've converted to is not reference-related to the 3777 // type we're looking for, then there is another conversion step 3778 // we need to perform to produce a temporary of the right type 3779 // that we'll be binding to. 3780 ImplicitConversionSequence ICS; 3781 ICS.setStandard(); 3782 ICS.Standard = Best->FinalConversion; 3783 T2 = ICS.Standard.getToType(2); 3784 Sequence.AddConversionSequenceStep(ICS, T2); 3785 } else if (NewDerivedToBase) 3786 Sequence.AddDerivedToBaseCastStep( 3787 S.Context.getQualifiedType(T1, 3788 T2.getNonReferenceType().getQualifiers()), 3789 VK); 3790 else if (NewObjCConversion) 3791 Sequence.AddObjCObjectConversionStep( 3792 S.Context.getQualifiedType(T1, 3793 T2.getNonReferenceType().getQualifiers())); 3794 3795 if (cv1T1.getQualifiers() != T2.getNonReferenceType().getQualifiers()) 3796 Sequence.AddQualificationConversionStep(cv1T1, VK); 3797 3798 Sequence.AddReferenceBindingStep(cv1T1, !T2->isReferenceType()); 3799 return OR_Success; 3800 } 3801 3802 static void CheckCXX98CompatAccessibleCopy(Sema &S, 3803 const InitializedEntity &Entity, 3804 Expr *CurInitExpr); 3805 3806 /// \brief Attempt reference initialization (C++0x [dcl.init.ref]) 3807 static void TryReferenceInitialization(Sema &S, 3808 const InitializedEntity &Entity, 3809 const InitializationKind &Kind, 3810 Expr *Initializer, 3811 InitializationSequence &Sequence) { 3812 QualType DestType = Entity.getType(); 3813 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 3814 Qualifiers T1Quals; 3815 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals); 3816 QualType cv2T2 = Initializer->getType(); 3817 Qualifiers T2Quals; 3818 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals); 3819 3820 // If the initializer is the address of an overloaded function, try 3821 // to resolve the overloaded function. If all goes well, T2 is the 3822 // type of the resulting function. 3823 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2, 3824 T1, Sequence)) 3825 return; 3826 3827 // Delegate everything else to a subfunction. 3828 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1, 3829 T1Quals, cv2T2, T2, T2Quals, Sequence); 3830 } 3831 3832 /// Converts the target of reference initialization so that it has the 3833 /// appropriate qualifiers and value kind. 3834 /// 3835 /// In this case, 'x' is an 'int' lvalue, but it needs to be 'const int'. 3836 /// \code 3837 /// int x; 3838 /// const int &r = x; 3839 /// \endcode 3840 /// 3841 /// In this case the reference is binding to a bitfield lvalue, which isn't 3842 /// valid. Perform a load to create a lifetime-extended temporary instead. 3843 /// \code 3844 /// const int &r = someStruct.bitfield; 3845 /// \endcode 3846 static ExprValueKind 3847 convertQualifiersAndValueKindIfNecessary(Sema &S, 3848 InitializationSequence &Sequence, 3849 Expr *Initializer, 3850 QualType cv1T1, 3851 Qualifiers T1Quals, 3852 Qualifiers T2Quals, 3853 bool IsLValueRef) { 3854 bool IsNonAddressableType = Initializer->refersToBitField() || 3855 Initializer->refersToVectorElement(); 3856 3857 if (IsNonAddressableType) { 3858 // C++11 [dcl.init.ref]p5: [...] Otherwise, the reference shall be an 3859 // lvalue reference to a non-volatile const type, or the reference shall be 3860 // an rvalue reference. 3861 // 3862 // If not, we can't make a temporary and bind to that. Give up and allow the 3863 // error to be diagnosed later. 3864 if (IsLValueRef && (!T1Quals.hasConst() || T1Quals.hasVolatile())) { 3865 assert(Initializer->isGLValue()); 3866 return Initializer->getValueKind(); 3867 } 3868 3869 // Force a load so we can materialize a temporary. 3870 Sequence.AddLValueToRValueStep(cv1T1.getUnqualifiedType()); 3871 return VK_RValue; 3872 } 3873 3874 if (T1Quals != T2Quals) { 3875 Sequence.AddQualificationConversionStep(cv1T1, 3876 Initializer->getValueKind()); 3877 } 3878 3879 return Initializer->getValueKind(); 3880 } 3881 3882 3883 /// \brief Reference initialization without resolving overloaded functions. 3884 static void TryReferenceInitializationCore(Sema &S, 3885 const InitializedEntity &Entity, 3886 const InitializationKind &Kind, 3887 Expr *Initializer, 3888 QualType cv1T1, QualType T1, 3889 Qualifiers T1Quals, 3890 QualType cv2T2, QualType T2, 3891 Qualifiers T2Quals, 3892 InitializationSequence &Sequence) { 3893 QualType DestType = Entity.getType(); 3894 SourceLocation DeclLoc = Initializer->getLocStart(); 3895 // Compute some basic properties of the types and the initializer. 3896 bool isLValueRef = DestType->isLValueReferenceType(); 3897 bool isRValueRef = !isLValueRef; 3898 bool DerivedToBase = false; 3899 bool ObjCConversion = false; 3900 bool ObjCLifetimeConversion = false; 3901 Expr::Classification InitCategory = Initializer->Classify(S.Context); 3902 Sema::ReferenceCompareResult RefRelationship 3903 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, DerivedToBase, 3904 ObjCConversion, ObjCLifetimeConversion); 3905 3906 // C++0x [dcl.init.ref]p5: 3907 // A reference to type "cv1 T1" is initialized by an expression of type 3908 // "cv2 T2" as follows: 3909 // 3910 // - If the reference is an lvalue reference and the initializer 3911 // expression 3912 // Note the analogous bullet points for rvalue refs to functions. Because 3913 // there are no function rvalues in C++, rvalue refs to functions are treated 3914 // like lvalue refs. 3915 OverloadingResult ConvOvlResult = OR_Success; 3916 bool T1Function = T1->isFunctionType(); 3917 if (isLValueRef || T1Function) { 3918 if (InitCategory.isLValue() && 3919 (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification || 3920 (Kind.isCStyleOrFunctionalCast() && 3921 RefRelationship == Sema::Ref_Related))) { 3922 // - is an lvalue (but is not a bit-field), and "cv1 T1" is 3923 // reference-compatible with "cv2 T2," or 3924 // 3925 // Per C++ [over.best.ics]p2, we don't diagnose whether the lvalue is a 3926 // bit-field when we're determining whether the reference initialization 3927 // can occur. However, we do pay attention to whether it is a bit-field 3928 // to decide whether we're actually binding to a temporary created from 3929 // the bit-field. 3930 if (DerivedToBase) 3931 Sequence.AddDerivedToBaseCastStep( 3932 S.Context.getQualifiedType(T1, T2Quals), 3933 VK_LValue); 3934 else if (ObjCConversion) 3935 Sequence.AddObjCObjectConversionStep( 3936 S.Context.getQualifiedType(T1, T2Quals)); 3937 3938 ExprValueKind ValueKind = 3939 convertQualifiersAndValueKindIfNecessary(S, Sequence, Initializer, 3940 cv1T1, T1Quals, T2Quals, 3941 isLValueRef); 3942 Sequence.AddReferenceBindingStep(cv1T1, ValueKind == VK_RValue); 3943 return; 3944 } 3945 3946 // - has a class type (i.e., T2 is a class type), where T1 is not 3947 // reference-related to T2, and can be implicitly converted to an 3948 // lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible 3949 // with "cv3 T3" (this conversion is selected by enumerating the 3950 // applicable conversion functions (13.3.1.6) and choosing the best 3951 // one through overload resolution (13.3)), 3952 // If we have an rvalue ref to function type here, the rhs must be 3953 // an rvalue. DR1287 removed the "implicitly" here. 3954 if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType() && 3955 (isLValueRef || InitCategory.isRValue())) { 3956 ConvOvlResult = TryRefInitWithConversionFunction( 3957 S, Entity, Kind, Initializer, /*AllowRValues*/isRValueRef, Sequence); 3958 if (ConvOvlResult == OR_Success) 3959 return; 3960 if (ConvOvlResult != OR_No_Viable_Function) 3961 Sequence.SetOverloadFailure( 3962 InitializationSequence::FK_ReferenceInitOverloadFailed, 3963 ConvOvlResult); 3964 } 3965 } 3966 3967 // - Otherwise, the reference shall be an lvalue reference to a 3968 // non-volatile const type (i.e., cv1 shall be const), or the reference 3969 // shall be an rvalue reference. 3970 if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile())) { 3971 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) 3972 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 3973 else if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty()) 3974 Sequence.SetOverloadFailure( 3975 InitializationSequence::FK_ReferenceInitOverloadFailed, 3976 ConvOvlResult); 3977 else 3978 Sequence.SetFailed(InitCategory.isLValue() 3979 ? (RefRelationship == Sema::Ref_Related 3980 ? InitializationSequence::FK_ReferenceInitDropsQualifiers 3981 : InitializationSequence::FK_NonConstLValueReferenceBindingToUnrelated) 3982 : InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary); 3983 3984 return; 3985 } 3986 3987 // - If the initializer expression 3988 // - is an xvalue, class prvalue, array prvalue, or function lvalue and 3989 // "cv1 T1" is reference-compatible with "cv2 T2" 3990 // Note: functions are handled below. 3991 if (!T1Function && 3992 (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification || 3993 (Kind.isCStyleOrFunctionalCast() && 3994 RefRelationship == Sema::Ref_Related)) && 3995 (InitCategory.isXValue() || 3996 (InitCategory.isPRValue() && T2->isRecordType()) || 3997 (InitCategory.isPRValue() && T2->isArrayType()))) { 3998 ExprValueKind ValueKind = InitCategory.isXValue()? VK_XValue : VK_RValue; 3999 if (InitCategory.isPRValue() && T2->isRecordType()) { 4000 // The corresponding bullet in C++03 [dcl.init.ref]p5 gives the 4001 // compiler the freedom to perform a copy here or bind to the 4002 // object, while C++0x requires that we bind directly to the 4003 // object. Hence, we always bind to the object without making an 4004 // extra copy. However, in C++03 requires that we check for the 4005 // presence of a suitable copy constructor: 4006 // 4007 // The constructor that would be used to make the copy shall 4008 // be callable whether or not the copy is actually done. 4009 if (!S.getLangOpts().CPlusPlus11 && !S.getLangOpts().MicrosoftExt) 4010 Sequence.AddExtraneousCopyToTemporary(cv2T2); 4011 else if (S.getLangOpts().CPlusPlus11) 4012 CheckCXX98CompatAccessibleCopy(S, Entity, Initializer); 4013 } 4014 4015 if (DerivedToBase) 4016 Sequence.AddDerivedToBaseCastStep(S.Context.getQualifiedType(T1, T2Quals), 4017 ValueKind); 4018 else if (ObjCConversion) 4019 Sequence.AddObjCObjectConversionStep( 4020 S.Context.getQualifiedType(T1, T2Quals)); 4021 4022 ValueKind = convertQualifiersAndValueKindIfNecessary(S, Sequence, 4023 Initializer, cv1T1, 4024 T1Quals, T2Quals, 4025 isLValueRef); 4026 4027 Sequence.AddReferenceBindingStep(cv1T1, ValueKind == VK_RValue); 4028 return; 4029 } 4030 4031 // - has a class type (i.e., T2 is a class type), where T1 is not 4032 // reference-related to T2, and can be implicitly converted to an 4033 // xvalue, class prvalue, or function lvalue of type "cv3 T3", 4034 // where "cv1 T1" is reference-compatible with "cv3 T3", 4035 // 4036 // DR1287 removes the "implicitly" here. 4037 if (T2->isRecordType()) { 4038 if (RefRelationship == Sema::Ref_Incompatible) { 4039 ConvOvlResult = TryRefInitWithConversionFunction( 4040 S, Entity, Kind, Initializer, /*AllowRValues*/true, Sequence); 4041 if (ConvOvlResult) 4042 Sequence.SetOverloadFailure( 4043 InitializationSequence::FK_ReferenceInitOverloadFailed, 4044 ConvOvlResult); 4045 4046 return; 4047 } 4048 4049 if ((RefRelationship == Sema::Ref_Compatible || 4050 RefRelationship == Sema::Ref_Compatible_With_Added_Qualification) && 4051 isRValueRef && InitCategory.isLValue()) { 4052 Sequence.SetFailed( 4053 InitializationSequence::FK_RValueReferenceBindingToLValue); 4054 return; 4055 } 4056 4057 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers); 4058 return; 4059 } 4060 4061 // - Otherwise, a temporary of type "cv1 T1" is created and initialized 4062 // from the initializer expression using the rules for a non-reference 4063 // copy-initialization (8.5). The reference is then bound to the 4064 // temporary. [...] 4065 4066 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1); 4067 4068 // FIXME: Why do we use an implicit conversion here rather than trying 4069 // copy-initialization? 4070 ImplicitConversionSequence ICS 4071 = S.TryImplicitConversion(Initializer, TempEntity.getType(), 4072 /*SuppressUserConversions=*/false, 4073 /*AllowExplicit=*/false, 4074 /*FIXME:InOverloadResolution=*/false, 4075 /*CStyle=*/Kind.isCStyleOrFunctionalCast(), 4076 /*AllowObjCWritebackConversion=*/false); 4077 4078 if (ICS.isBad()) { 4079 // FIXME: Use the conversion function set stored in ICS to turn 4080 // this into an overloading ambiguity diagnostic. However, we need 4081 // to keep that set as an OverloadCandidateSet rather than as some 4082 // other kind of set. 4083 if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty()) 4084 Sequence.SetOverloadFailure( 4085 InitializationSequence::FK_ReferenceInitOverloadFailed, 4086 ConvOvlResult); 4087 else if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) 4088 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 4089 else 4090 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed); 4091 return; 4092 } else { 4093 Sequence.AddConversionSequenceStep(ICS, TempEntity.getType()); 4094 } 4095 4096 // [...] If T1 is reference-related to T2, cv1 must be the 4097 // same cv-qualification as, or greater cv-qualification 4098 // than, cv2; otherwise, the program is ill-formed. 4099 unsigned T1CVRQuals = T1Quals.getCVRQualifiers(); 4100 unsigned T2CVRQuals = T2Quals.getCVRQualifiers(); 4101 if (RefRelationship == Sema::Ref_Related && 4102 (T1CVRQuals | T2CVRQuals) != T1CVRQuals) { 4103 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers); 4104 return; 4105 } 4106 4107 // [...] If T1 is reference-related to T2 and the reference is an rvalue 4108 // reference, the initializer expression shall not be an lvalue. 4109 if (RefRelationship >= Sema::Ref_Related && !isLValueRef && 4110 InitCategory.isLValue()) { 4111 Sequence.SetFailed( 4112 InitializationSequence::FK_RValueReferenceBindingToLValue); 4113 return; 4114 } 4115 4116 Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true); 4117 return; 4118 } 4119 4120 /// \brief Attempt character array initialization from a string literal 4121 /// (C++ [dcl.init.string], C99 6.7.8). 4122 static void TryStringLiteralInitialization(Sema &S, 4123 const InitializedEntity &Entity, 4124 const InitializationKind &Kind, 4125 Expr *Initializer, 4126 InitializationSequence &Sequence) { 4127 Sequence.AddStringInitStep(Entity.getType()); 4128 } 4129 4130 /// \brief Attempt value initialization (C++ [dcl.init]p7). 4131 static void TryValueInitialization(Sema &S, 4132 const InitializedEntity &Entity, 4133 const InitializationKind &Kind, 4134 InitializationSequence &Sequence, 4135 InitListExpr *InitList) { 4136 assert((!InitList || InitList->getNumInits() == 0) && 4137 "Shouldn't use value-init for non-empty init lists"); 4138 4139 // C++98 [dcl.init]p5, C++11 [dcl.init]p7: 4140 // 4141 // To value-initialize an object of type T means: 4142 QualType T = Entity.getType(); 4143 4144 // -- if T is an array type, then each element is value-initialized; 4145 T = S.Context.getBaseElementType(T); 4146 4147 if (const RecordType *RT = T->getAs<RecordType>()) { 4148 if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 4149 bool NeedZeroInitialization = true; 4150 if (!S.getLangOpts().CPlusPlus11) { 4151 // C++98: 4152 // -- if T is a class type (clause 9) with a user-declared constructor 4153 // (12.1), then the default constructor for T is called (and the 4154 // initialization is ill-formed if T has no accessible default 4155 // constructor); 4156 if (ClassDecl->hasUserDeclaredConstructor()) 4157 NeedZeroInitialization = false; 4158 } else { 4159 // C++11: 4160 // -- if T is a class type (clause 9) with either no default constructor 4161 // (12.1 [class.ctor]) or a default constructor that is user-provided 4162 // or deleted, then the object is default-initialized; 4163 CXXConstructorDecl *CD = S.LookupDefaultConstructor(ClassDecl); 4164 if (!CD || !CD->getCanonicalDecl()->isDefaulted() || CD->isDeleted()) 4165 NeedZeroInitialization = false; 4166 } 4167 4168 // -- if T is a (possibly cv-qualified) non-union class type without a 4169 // user-provided or deleted default constructor, then the object is 4170 // zero-initialized and, if T has a non-trivial default constructor, 4171 // default-initialized; 4172 // The 'non-union' here was removed by DR1502. The 'non-trivial default 4173 // constructor' part was removed by DR1507. 4174 if (NeedZeroInitialization) 4175 Sequence.AddZeroInitializationStep(Entity.getType()); 4176 4177 // C++03: 4178 // -- if T is a non-union class type without a user-declared constructor, 4179 // then every non-static data member and base class component of T is 4180 // value-initialized; 4181 // [...] A program that calls for [...] value-initialization of an 4182 // entity of reference type is ill-formed. 4183 // 4184 // C++11 doesn't need this handling, because value-initialization does not 4185 // occur recursively there, and the implicit default constructor is 4186 // defined as deleted in the problematic cases. 4187 if (!S.getLangOpts().CPlusPlus11 && 4188 ClassDecl->hasUninitializedReferenceMember()) { 4189 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForReference); 4190 return; 4191 } 4192 4193 // If this is list-value-initialization, pass the empty init list on when 4194 // building the constructor call. This affects the semantics of a few 4195 // things (such as whether an explicit default constructor can be called). 4196 Expr *InitListAsExpr = InitList; 4197 MultiExprArg Args(&InitListAsExpr, InitList ? 1 : 0); 4198 bool InitListSyntax = InitList; 4199 4200 return TryConstructorInitialization(S, Entity, Kind, Args, T, Sequence, 4201 InitListSyntax); 4202 } 4203 } 4204 4205 Sequence.AddZeroInitializationStep(Entity.getType()); 4206 } 4207 4208 /// \brief Attempt default initialization (C++ [dcl.init]p6). 4209 static void TryDefaultInitialization(Sema &S, 4210 const InitializedEntity &Entity, 4211 const InitializationKind &Kind, 4212 InitializationSequence &Sequence) { 4213 assert(Kind.getKind() == InitializationKind::IK_Default); 4214 4215 // C++ [dcl.init]p6: 4216 // To default-initialize an object of type T means: 4217 // - if T is an array type, each element is default-initialized; 4218 QualType DestType = S.Context.getBaseElementType(Entity.getType()); 4219 4220 // - if T is a (possibly cv-qualified) class type (Clause 9), the default 4221 // constructor for T is called (and the initialization is ill-formed if 4222 // T has no accessible default constructor); 4223 if (DestType->isRecordType() && S.getLangOpts().CPlusPlus) { 4224 TryConstructorInitialization(S, Entity, Kind, None, DestType, Sequence); 4225 return; 4226 } 4227 4228 // - otherwise, no initialization is performed. 4229 4230 // If a program calls for the default initialization of an object of 4231 // a const-qualified type T, T shall be a class type with a user-provided 4232 // default constructor. 4233 if (DestType.isConstQualified() && S.getLangOpts().CPlusPlus) { 4234 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst); 4235 return; 4236 } 4237 4238 // If the destination type has a lifetime property, zero-initialize it. 4239 if (DestType.getQualifiers().hasObjCLifetime()) { 4240 Sequence.AddZeroInitializationStep(Entity.getType()); 4241 return; 4242 } 4243 } 4244 4245 /// \brief Attempt a user-defined conversion between two types (C++ [dcl.init]), 4246 /// which enumerates all conversion functions and performs overload resolution 4247 /// to select the best. 4248 static void TryUserDefinedConversion(Sema &S, 4249 QualType DestType, 4250 const InitializationKind &Kind, 4251 Expr *Initializer, 4252 InitializationSequence &Sequence, 4253 bool TopLevelOfInitList) { 4254 assert(!DestType->isReferenceType() && "References are handled elsewhere"); 4255 QualType SourceType = Initializer->getType(); 4256 assert((DestType->isRecordType() || SourceType->isRecordType()) && 4257 "Must have a class type to perform a user-defined conversion"); 4258 4259 // Build the candidate set directly in the initialization sequence 4260 // structure, so that it will persist if we fail. 4261 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 4262 CandidateSet.clear(); 4263 4264 // Determine whether we are allowed to call explicit constructors or 4265 // explicit conversion operators. 4266 bool AllowExplicit = Kind.AllowExplicit(); 4267 4268 if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) { 4269 // The type we're converting to is a class type. Enumerate its constructors 4270 // to see if there is a suitable conversion. 4271 CXXRecordDecl *DestRecordDecl 4272 = cast<CXXRecordDecl>(DestRecordType->getDecl()); 4273 4274 // Try to complete the type we're converting to. 4275 if (!S.RequireCompleteType(Kind.getLocation(), DestType, 0)) { 4276 DeclContext::lookup_result R = S.LookupConstructors(DestRecordDecl); 4277 // The container holding the constructors can under certain conditions 4278 // be changed while iterating. To be safe we copy the lookup results 4279 // to a new container. 4280 SmallVector<NamedDecl*, 8> CopyOfCon(R.begin(), R.end()); 4281 for (SmallVectorImpl<NamedDecl *>::iterator 4282 Con = CopyOfCon.begin(), ConEnd = CopyOfCon.end(); 4283 Con != ConEnd; ++Con) { 4284 NamedDecl *D = *Con; 4285 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 4286 4287 // Find the constructor (which may be a template). 4288 CXXConstructorDecl *Constructor = nullptr; 4289 FunctionTemplateDecl *ConstructorTmpl 4290 = dyn_cast<FunctionTemplateDecl>(D); 4291 if (ConstructorTmpl) 4292 Constructor = cast<CXXConstructorDecl>( 4293 ConstructorTmpl->getTemplatedDecl()); 4294 else 4295 Constructor = cast<CXXConstructorDecl>(D); 4296 4297 if (!Constructor->isInvalidDecl() && 4298 Constructor->isConvertingConstructor(AllowExplicit)) { 4299 if (ConstructorTmpl) 4300 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 4301 /*ExplicitArgs*/ nullptr, 4302 Initializer, CandidateSet, 4303 /*SuppressUserConversions=*/true); 4304 else 4305 S.AddOverloadCandidate(Constructor, FoundDecl, 4306 Initializer, CandidateSet, 4307 /*SuppressUserConversions=*/true); 4308 } 4309 } 4310 } 4311 } 4312 4313 SourceLocation DeclLoc = Initializer->getLocStart(); 4314 4315 if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) { 4316 // The type we're converting from is a class type, enumerate its conversion 4317 // functions. 4318 4319 // We can only enumerate the conversion functions for a complete type; if 4320 // the type isn't complete, simply skip this step. 4321 if (!S.RequireCompleteType(DeclLoc, SourceType, 0)) { 4322 CXXRecordDecl *SourceRecordDecl 4323 = cast<CXXRecordDecl>(SourceRecordType->getDecl()); 4324 4325 const auto &Conversions = 4326 SourceRecordDecl->getVisibleConversionFunctions(); 4327 for (auto I = Conversions.begin(), E = Conversions.end(); I != E; ++I) { 4328 NamedDecl *D = *I; 4329 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 4330 if (isa<UsingShadowDecl>(D)) 4331 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4332 4333 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D); 4334 CXXConversionDecl *Conv; 4335 if (ConvTemplate) 4336 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 4337 else 4338 Conv = cast<CXXConversionDecl>(D); 4339 4340 if (AllowExplicit || !Conv->isExplicit()) { 4341 if (ConvTemplate) 4342 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), 4343 ActingDC, Initializer, DestType, 4344 CandidateSet, AllowExplicit); 4345 else 4346 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, 4347 Initializer, DestType, CandidateSet, 4348 AllowExplicit); 4349 } 4350 } 4351 } 4352 } 4353 4354 // Perform overload resolution. If it fails, return the failed result. 4355 OverloadCandidateSet::iterator Best; 4356 if (OverloadingResult Result 4357 = CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 4358 Sequence.SetOverloadFailure( 4359 InitializationSequence::FK_UserConversionOverloadFailed, 4360 Result); 4361 return; 4362 } 4363 4364 FunctionDecl *Function = Best->Function; 4365 Function->setReferenced(); 4366 bool HadMultipleCandidates = (CandidateSet.size() > 1); 4367 4368 if (isa<CXXConstructorDecl>(Function)) { 4369 // Add the user-defined conversion step. Any cv-qualification conversion is 4370 // subsumed by the initialization. Per DR5, the created temporary is of the 4371 // cv-unqualified type of the destination. 4372 Sequence.AddUserConversionStep(Function, Best->FoundDecl, 4373 DestType.getUnqualifiedType(), 4374 HadMultipleCandidates); 4375 return; 4376 } 4377 4378 // Add the user-defined conversion step that calls the conversion function. 4379 QualType ConvType = Function->getCallResultType(); 4380 if (ConvType->getAs<RecordType>()) { 4381 // If we're converting to a class type, there may be an copy of 4382 // the resulting temporary object (possible to create an object of 4383 // a base class type). That copy is not a separate conversion, so 4384 // we just make a note of the actual destination type (possibly a 4385 // base class of the type returned by the conversion function) and 4386 // let the user-defined conversion step handle the conversion. 4387 Sequence.AddUserConversionStep(Function, Best->FoundDecl, DestType, 4388 HadMultipleCandidates); 4389 return; 4390 } 4391 4392 Sequence.AddUserConversionStep(Function, Best->FoundDecl, ConvType, 4393 HadMultipleCandidates); 4394 4395 // If the conversion following the call to the conversion function 4396 // is interesting, add it as a separate step. 4397 if (Best->FinalConversion.First || Best->FinalConversion.Second || 4398 Best->FinalConversion.Third) { 4399 ImplicitConversionSequence ICS; 4400 ICS.setStandard(); 4401 ICS.Standard = Best->FinalConversion; 4402 Sequence.AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList); 4403 } 4404 } 4405 4406 /// An egregious hack for compatibility with libstdc++-4.2: in <tr1/hashtable>, 4407 /// a function with a pointer return type contains a 'return false;' statement. 4408 /// In C++11, 'false' is not a null pointer, so this breaks the build of any 4409 /// code using that header. 4410 /// 4411 /// Work around this by treating 'return false;' as zero-initializing the result 4412 /// if it's used in a pointer-returning function in a system header. 4413 static bool isLibstdcxxPointerReturnFalseHack(Sema &S, 4414 const InitializedEntity &Entity, 4415 const Expr *Init) { 4416 return S.getLangOpts().CPlusPlus11 && 4417 Entity.getKind() == InitializedEntity::EK_Result && 4418 Entity.getType()->isPointerType() && 4419 isa<CXXBoolLiteralExpr>(Init) && 4420 !cast<CXXBoolLiteralExpr>(Init)->getValue() && 4421 S.getSourceManager().isInSystemHeader(Init->getExprLoc()); 4422 } 4423 4424 /// The non-zero enum values here are indexes into diagnostic alternatives. 4425 enum InvalidICRKind { IIK_okay, IIK_nonlocal, IIK_nonscalar }; 4426 4427 /// Determines whether this expression is an acceptable ICR source. 4428 static InvalidICRKind isInvalidICRSource(ASTContext &C, Expr *e, 4429 bool isAddressOf, bool &isWeakAccess) { 4430 // Skip parens. 4431 e = e->IgnoreParens(); 4432 4433 // Skip address-of nodes. 4434 if (UnaryOperator *op = dyn_cast<UnaryOperator>(e)) { 4435 if (op->getOpcode() == UO_AddrOf) 4436 return isInvalidICRSource(C, op->getSubExpr(), /*addressof*/ true, 4437 isWeakAccess); 4438 4439 // Skip certain casts. 4440 } else if (CastExpr *ce = dyn_cast<CastExpr>(e)) { 4441 switch (ce->getCastKind()) { 4442 case CK_Dependent: 4443 case CK_BitCast: 4444 case CK_LValueBitCast: 4445 case CK_NoOp: 4446 return isInvalidICRSource(C, ce->getSubExpr(), isAddressOf, isWeakAccess); 4447 4448 case CK_ArrayToPointerDecay: 4449 return IIK_nonscalar; 4450 4451 case CK_NullToPointer: 4452 return IIK_okay; 4453 4454 default: 4455 break; 4456 } 4457 4458 // If we have a declaration reference, it had better be a local variable. 4459 } else if (isa<DeclRefExpr>(e)) { 4460 // set isWeakAccess to true, to mean that there will be an implicit 4461 // load which requires a cleanup. 4462 if (e->getType().getObjCLifetime() == Qualifiers::OCL_Weak) 4463 isWeakAccess = true; 4464 4465 if (!isAddressOf) return IIK_nonlocal; 4466 4467 VarDecl *var = dyn_cast<VarDecl>(cast<DeclRefExpr>(e)->getDecl()); 4468 if (!var) return IIK_nonlocal; 4469 4470 return (var->hasLocalStorage() ? IIK_okay : IIK_nonlocal); 4471 4472 // If we have a conditional operator, check both sides. 4473 } else if (ConditionalOperator *cond = dyn_cast<ConditionalOperator>(e)) { 4474 if (InvalidICRKind iik = isInvalidICRSource(C, cond->getLHS(), isAddressOf, 4475 isWeakAccess)) 4476 return iik; 4477 4478 return isInvalidICRSource(C, cond->getRHS(), isAddressOf, isWeakAccess); 4479 4480 // These are never scalar. 4481 } else if (isa<ArraySubscriptExpr>(e)) { 4482 return IIK_nonscalar; 4483 4484 // Otherwise, it needs to be a null pointer constant. 4485 } else { 4486 return (e->isNullPointerConstant(C, Expr::NPC_ValueDependentIsNull) 4487 ? IIK_okay : IIK_nonlocal); 4488 } 4489 4490 return IIK_nonlocal; 4491 } 4492 4493 /// Check whether the given expression is a valid operand for an 4494 /// indirect copy/restore. 4495 static void checkIndirectCopyRestoreSource(Sema &S, Expr *src) { 4496 assert(src->isRValue()); 4497 bool isWeakAccess = false; 4498 InvalidICRKind iik = isInvalidICRSource(S.Context, src, false, isWeakAccess); 4499 // If isWeakAccess to true, there will be an implicit 4500 // load which requires a cleanup. 4501 if (S.getLangOpts().ObjCAutoRefCount && isWeakAccess) 4502 S.ExprNeedsCleanups = true; 4503 4504 if (iik == IIK_okay) return; 4505 4506 S.Diag(src->getExprLoc(), diag::err_arc_nonlocal_writeback) 4507 << ((unsigned) iik - 1) // shift index into diagnostic explanations 4508 << src->getSourceRange(); 4509 } 4510 4511 /// \brief Determine whether we have compatible array types for the 4512 /// purposes of GNU by-copy array initialization. 4513 static bool hasCompatibleArrayTypes(ASTContext &Context, const ArrayType *Dest, 4514 const ArrayType *Source) { 4515 // If the source and destination array types are equivalent, we're 4516 // done. 4517 if (Context.hasSameType(QualType(Dest, 0), QualType(Source, 0))) 4518 return true; 4519 4520 // Make sure that the element types are the same. 4521 if (!Context.hasSameType(Dest->getElementType(), Source->getElementType())) 4522 return false; 4523 4524 // The only mismatch we allow is when the destination is an 4525 // incomplete array type and the source is a constant array type. 4526 return Source->isConstantArrayType() && Dest->isIncompleteArrayType(); 4527 } 4528 4529 static bool tryObjCWritebackConversion(Sema &S, 4530 InitializationSequence &Sequence, 4531 const InitializedEntity &Entity, 4532 Expr *Initializer) { 4533 bool ArrayDecay = false; 4534 QualType ArgType = Initializer->getType(); 4535 QualType ArgPointee; 4536 if (const ArrayType *ArgArrayType = S.Context.getAsArrayType(ArgType)) { 4537 ArrayDecay = true; 4538 ArgPointee = ArgArrayType->getElementType(); 4539 ArgType = S.Context.getPointerType(ArgPointee); 4540 } 4541 4542 // Handle write-back conversion. 4543 QualType ConvertedArgType; 4544 if (!S.isObjCWritebackConversion(ArgType, Entity.getType(), 4545 ConvertedArgType)) 4546 return false; 4547 4548 // We should copy unless we're passing to an argument explicitly 4549 // marked 'out'. 4550 bool ShouldCopy = true; 4551 if (ParmVarDecl *param = cast_or_null<ParmVarDecl>(Entity.getDecl())) 4552 ShouldCopy = (param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out); 4553 4554 // Do we need an lvalue conversion? 4555 if (ArrayDecay || Initializer->isGLValue()) { 4556 ImplicitConversionSequence ICS; 4557 ICS.setStandard(); 4558 ICS.Standard.setAsIdentityConversion(); 4559 4560 QualType ResultType; 4561 if (ArrayDecay) { 4562 ICS.Standard.First = ICK_Array_To_Pointer; 4563 ResultType = S.Context.getPointerType(ArgPointee); 4564 } else { 4565 ICS.Standard.First = ICK_Lvalue_To_Rvalue; 4566 ResultType = Initializer->getType().getNonLValueExprType(S.Context); 4567 } 4568 4569 Sequence.AddConversionSequenceStep(ICS, ResultType); 4570 } 4571 4572 Sequence.AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy); 4573 return true; 4574 } 4575 4576 static bool TryOCLSamplerInitialization(Sema &S, 4577 InitializationSequence &Sequence, 4578 QualType DestType, 4579 Expr *Initializer) { 4580 if (!S.getLangOpts().OpenCL || !DestType->isSamplerT() || 4581 !Initializer->isIntegerConstantExpr(S.getASTContext())) 4582 return false; 4583 4584 Sequence.AddOCLSamplerInitStep(DestType); 4585 return true; 4586 } 4587 4588 // 4589 // OpenCL 1.2 spec, s6.12.10 4590 // 4591 // The event argument can also be used to associate the 4592 // async_work_group_copy with a previous async copy allowing 4593 // an event to be shared by multiple async copies; otherwise 4594 // event should be zero. 4595 // 4596 static bool TryOCLZeroEventInitialization(Sema &S, 4597 InitializationSequence &Sequence, 4598 QualType DestType, 4599 Expr *Initializer) { 4600 if (!S.getLangOpts().OpenCL || !DestType->isEventT() || 4601 !Initializer->isIntegerConstantExpr(S.getASTContext()) || 4602 (Initializer->EvaluateKnownConstInt(S.getASTContext()) != 0)) 4603 return false; 4604 4605 Sequence.AddOCLZeroEventStep(DestType); 4606 return true; 4607 } 4608 4609 InitializationSequence::InitializationSequence(Sema &S, 4610 const InitializedEntity &Entity, 4611 const InitializationKind &Kind, 4612 MultiExprArg Args, 4613 bool TopLevelOfInitList) 4614 : FailedCandidateSet(Kind.getLocation(), OverloadCandidateSet::CSK_Normal) { 4615 InitializeFrom(S, Entity, Kind, Args, TopLevelOfInitList); 4616 } 4617 4618 void InitializationSequence::InitializeFrom(Sema &S, 4619 const InitializedEntity &Entity, 4620 const InitializationKind &Kind, 4621 MultiExprArg Args, 4622 bool TopLevelOfInitList) { 4623 ASTContext &Context = S.Context; 4624 4625 // Eliminate non-overload placeholder types in the arguments. We 4626 // need to do this before checking whether types are dependent 4627 // because lowering a pseudo-object expression might well give us 4628 // something of dependent type. 4629 for (unsigned I = 0, E = Args.size(); I != E; ++I) 4630 if (Args[I]->getType()->isNonOverloadPlaceholderType()) { 4631 // FIXME: should we be doing this here? 4632 ExprResult result = S.CheckPlaceholderExpr(Args[I]); 4633 if (result.isInvalid()) { 4634 SetFailed(FK_PlaceholderType); 4635 return; 4636 } 4637 Args[I] = result.get(); 4638 } 4639 4640 // C++0x [dcl.init]p16: 4641 // The semantics of initializers are as follows. The destination type is 4642 // the type of the object or reference being initialized and the source 4643 // type is the type of the initializer expression. The source type is not 4644 // defined when the initializer is a braced-init-list or when it is a 4645 // parenthesized list of expressions. 4646 QualType DestType = Entity.getType(); 4647 4648 if (DestType->isDependentType() || 4649 Expr::hasAnyTypeDependentArguments(Args)) { 4650 SequenceKind = DependentSequence; 4651 return; 4652 } 4653 4654 // Almost everything is a normal sequence. 4655 setSequenceKind(NormalSequence); 4656 4657 QualType SourceType; 4658 Expr *Initializer = nullptr; 4659 if (Args.size() == 1) { 4660 Initializer = Args[0]; 4661 if (S.getLangOpts().ObjC1) { 4662 if (S.CheckObjCBridgeRelatedConversions(Initializer->getLocStart(), 4663 DestType, Initializer->getType(), 4664 Initializer) || 4665 S.ConversionToObjCStringLiteralCheck(DestType, Initializer)) 4666 Args[0] = Initializer; 4667 } 4668 if (!isa<InitListExpr>(Initializer)) 4669 SourceType = Initializer->getType(); 4670 } 4671 4672 // - If the initializer is a (non-parenthesized) braced-init-list, the 4673 // object is list-initialized (8.5.4). 4674 if (Kind.getKind() != InitializationKind::IK_Direct) { 4675 if (InitListExpr *InitList = dyn_cast_or_null<InitListExpr>(Initializer)) { 4676 TryListInitialization(S, Entity, Kind, InitList, *this); 4677 return; 4678 } 4679 } 4680 4681 // - If the destination type is a reference type, see 8.5.3. 4682 if (DestType->isReferenceType()) { 4683 // C++0x [dcl.init.ref]p1: 4684 // A variable declared to be a T& or T&&, that is, "reference to type T" 4685 // (8.3.2), shall be initialized by an object, or function, of type T or 4686 // by an object that can be converted into a T. 4687 // (Therefore, multiple arguments are not permitted.) 4688 if (Args.size() != 1) 4689 SetFailed(FK_TooManyInitsForReference); 4690 else 4691 TryReferenceInitialization(S, Entity, Kind, Args[0], *this); 4692 return; 4693 } 4694 4695 // - If the initializer is (), the object is value-initialized. 4696 if (Kind.getKind() == InitializationKind::IK_Value || 4697 (Kind.getKind() == InitializationKind::IK_Direct && Args.empty())) { 4698 TryValueInitialization(S, Entity, Kind, *this); 4699 return; 4700 } 4701 4702 // Handle default initialization. 4703 if (Kind.getKind() == InitializationKind::IK_Default) { 4704 TryDefaultInitialization(S, Entity, Kind, *this); 4705 return; 4706 } 4707 4708 // - If the destination type is an array of characters, an array of 4709 // char16_t, an array of char32_t, or an array of wchar_t, and the 4710 // initializer is a string literal, see 8.5.2. 4711 // - Otherwise, if the destination type is an array, the program is 4712 // ill-formed. 4713 if (const ArrayType *DestAT = Context.getAsArrayType(DestType)) { 4714 if (Initializer && isa<VariableArrayType>(DestAT)) { 4715 SetFailed(FK_VariableLengthArrayHasInitializer); 4716 return; 4717 } 4718 4719 if (Initializer) { 4720 switch (IsStringInit(Initializer, DestAT, Context)) { 4721 case SIF_None: 4722 TryStringLiteralInitialization(S, Entity, Kind, Initializer, *this); 4723 return; 4724 case SIF_NarrowStringIntoWideChar: 4725 SetFailed(FK_NarrowStringIntoWideCharArray); 4726 return; 4727 case SIF_WideStringIntoChar: 4728 SetFailed(FK_WideStringIntoCharArray); 4729 return; 4730 case SIF_IncompatWideStringIntoWideChar: 4731 SetFailed(FK_IncompatWideStringIntoWideChar); 4732 return; 4733 case SIF_Other: 4734 break; 4735 } 4736 } 4737 4738 // Note: as an GNU C extension, we allow initialization of an 4739 // array from a compound literal that creates an array of the same 4740 // type, so long as the initializer has no side effects. 4741 if (!S.getLangOpts().CPlusPlus && Initializer && 4742 isa<CompoundLiteralExpr>(Initializer->IgnoreParens()) && 4743 Initializer->getType()->isArrayType()) { 4744 const ArrayType *SourceAT 4745 = Context.getAsArrayType(Initializer->getType()); 4746 if (!hasCompatibleArrayTypes(S.Context, DestAT, SourceAT)) 4747 SetFailed(FK_ArrayTypeMismatch); 4748 else if (Initializer->HasSideEffects(S.Context)) 4749 SetFailed(FK_NonConstantArrayInit); 4750 else { 4751 AddArrayInitStep(DestType); 4752 } 4753 } 4754 // Note: as a GNU C++ extension, we allow list-initialization of a 4755 // class member of array type from a parenthesized initializer list. 4756 else if (S.getLangOpts().CPlusPlus && 4757 Entity.getKind() == InitializedEntity::EK_Member && 4758 Initializer && isa<InitListExpr>(Initializer)) { 4759 TryListInitialization(S, Entity, Kind, cast<InitListExpr>(Initializer), 4760 *this); 4761 AddParenthesizedArrayInitStep(DestType); 4762 } else if (DestAT->getElementType()->isCharType()) 4763 SetFailed(FK_ArrayNeedsInitListOrStringLiteral); 4764 else if (IsWideCharCompatible(DestAT->getElementType(), Context)) 4765 SetFailed(FK_ArrayNeedsInitListOrWideStringLiteral); 4766 else 4767 SetFailed(FK_ArrayNeedsInitList); 4768 4769 return; 4770 } 4771 4772 // Determine whether we should consider writeback conversions for 4773 // Objective-C ARC. 4774 bool allowObjCWritebackConversion = S.getLangOpts().ObjCAutoRefCount && 4775 Entity.isParameterKind(); 4776 4777 // We're at the end of the line for C: it's either a write-back conversion 4778 // or it's a C assignment. There's no need to check anything else. 4779 if (!S.getLangOpts().CPlusPlus) { 4780 // If allowed, check whether this is an Objective-C writeback conversion. 4781 if (allowObjCWritebackConversion && 4782 tryObjCWritebackConversion(S, *this, Entity, Initializer)) { 4783 return; 4784 } 4785 4786 if (TryOCLSamplerInitialization(S, *this, DestType, Initializer)) 4787 return; 4788 4789 if (TryOCLZeroEventInitialization(S, *this, DestType, Initializer)) 4790 return; 4791 4792 // Handle initialization in C 4793 AddCAssignmentStep(DestType); 4794 MaybeProduceObjCObject(S, *this, Entity); 4795 return; 4796 } 4797 4798 assert(S.getLangOpts().CPlusPlus); 4799 4800 // - If the destination type is a (possibly cv-qualified) class type: 4801 if (DestType->isRecordType()) { 4802 // - If the initialization is direct-initialization, or if it is 4803 // copy-initialization where the cv-unqualified version of the 4804 // source type is the same class as, or a derived class of, the 4805 // class of the destination, constructors are considered. [...] 4806 if (Kind.getKind() == InitializationKind::IK_Direct || 4807 (Kind.getKind() == InitializationKind::IK_Copy && 4808 (Context.hasSameUnqualifiedType(SourceType, DestType) || 4809 S.IsDerivedFrom(SourceType, DestType)))) 4810 TryConstructorInitialization(S, Entity, Kind, Args, 4811 DestType, *this); 4812 // - Otherwise (i.e., for the remaining copy-initialization cases), 4813 // user-defined conversion sequences that can convert from the source 4814 // type to the destination type or (when a conversion function is 4815 // used) to a derived class thereof are enumerated as described in 4816 // 13.3.1.4, and the best one is chosen through overload resolution 4817 // (13.3). 4818 else 4819 TryUserDefinedConversion(S, DestType, Kind, Initializer, *this, 4820 TopLevelOfInitList); 4821 return; 4822 } 4823 4824 if (Args.size() > 1) { 4825 SetFailed(FK_TooManyInitsForScalar); 4826 return; 4827 } 4828 assert(Args.size() == 1 && "Zero-argument case handled above"); 4829 4830 // - Otherwise, if the source type is a (possibly cv-qualified) class 4831 // type, conversion functions are considered. 4832 if (!SourceType.isNull() && SourceType->isRecordType()) { 4833 // For a conversion to _Atomic(T) from either T or a class type derived 4834 // from T, initialize the T object then convert to _Atomic type. 4835 bool NeedAtomicConversion = false; 4836 if (const AtomicType *Atomic = DestType->getAs<AtomicType>()) { 4837 if (Context.hasSameUnqualifiedType(SourceType, Atomic->getValueType()) || 4838 S.IsDerivedFrom(SourceType, Atomic->getValueType())) { 4839 DestType = Atomic->getValueType(); 4840 NeedAtomicConversion = true; 4841 } 4842 } 4843 4844 TryUserDefinedConversion(S, DestType, Kind, Initializer, *this, 4845 TopLevelOfInitList); 4846 MaybeProduceObjCObject(S, *this, Entity); 4847 if (!Failed() && NeedAtomicConversion) 4848 AddAtomicConversionStep(Entity.getType()); 4849 return; 4850 } 4851 4852 // - Otherwise, the initial value of the object being initialized is the 4853 // (possibly converted) value of the initializer expression. Standard 4854 // conversions (Clause 4) will be used, if necessary, to convert the 4855 // initializer expression to the cv-unqualified version of the 4856 // destination type; no user-defined conversions are considered. 4857 4858 ImplicitConversionSequence ICS 4859 = S.TryImplicitConversion(Initializer, DestType, 4860 /*SuppressUserConversions*/true, 4861 /*AllowExplicitConversions*/ false, 4862 /*InOverloadResolution*/ false, 4863 /*CStyle=*/Kind.isCStyleOrFunctionalCast(), 4864 allowObjCWritebackConversion); 4865 4866 if (ICS.isStandard() && 4867 ICS.Standard.Second == ICK_Writeback_Conversion) { 4868 // Objective-C ARC writeback conversion. 4869 4870 // We should copy unless we're passing to an argument explicitly 4871 // marked 'out'. 4872 bool ShouldCopy = true; 4873 if (ParmVarDecl *Param = cast_or_null<ParmVarDecl>(Entity.getDecl())) 4874 ShouldCopy = (Param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out); 4875 4876 // If there was an lvalue adjustment, add it as a separate conversion. 4877 if (ICS.Standard.First == ICK_Array_To_Pointer || 4878 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 4879 ImplicitConversionSequence LvalueICS; 4880 LvalueICS.setStandard(); 4881 LvalueICS.Standard.setAsIdentityConversion(); 4882 LvalueICS.Standard.setAllToTypes(ICS.Standard.getToType(0)); 4883 LvalueICS.Standard.First = ICS.Standard.First; 4884 AddConversionSequenceStep(LvalueICS, ICS.Standard.getToType(0)); 4885 } 4886 4887 AddPassByIndirectCopyRestoreStep(DestType, ShouldCopy); 4888 } else if (ICS.isBad()) { 4889 DeclAccessPair dap; 4890 if (isLibstdcxxPointerReturnFalseHack(S, Entity, Initializer)) { 4891 AddZeroInitializationStep(Entity.getType()); 4892 } else if (Initializer->getType() == Context.OverloadTy && 4893 !S.ResolveAddressOfOverloadedFunction(Initializer, DestType, 4894 false, dap)) 4895 SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 4896 else 4897 SetFailed(InitializationSequence::FK_ConversionFailed); 4898 } else { 4899 AddConversionSequenceStep(ICS, DestType, TopLevelOfInitList); 4900 4901 MaybeProduceObjCObject(S, *this, Entity); 4902 } 4903 } 4904 4905 InitializationSequence::~InitializationSequence() { 4906 for (SmallVectorImpl<Step>::iterator Step = Steps.begin(), 4907 StepEnd = Steps.end(); 4908 Step != StepEnd; ++Step) 4909 Step->Destroy(); 4910 } 4911 4912 //===----------------------------------------------------------------------===// 4913 // Perform initialization 4914 //===----------------------------------------------------------------------===// 4915 static Sema::AssignmentAction 4916 getAssignmentAction(const InitializedEntity &Entity, bool Diagnose = false) { 4917 switch(Entity.getKind()) { 4918 case InitializedEntity::EK_Variable: 4919 case InitializedEntity::EK_New: 4920 case InitializedEntity::EK_Exception: 4921 case InitializedEntity::EK_Base: 4922 case InitializedEntity::EK_Delegating: 4923 return Sema::AA_Initializing; 4924 4925 case InitializedEntity::EK_Parameter: 4926 if (Entity.getDecl() && 4927 isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext())) 4928 return Sema::AA_Sending; 4929 4930 return Sema::AA_Passing; 4931 4932 case InitializedEntity::EK_Parameter_CF_Audited: 4933 if (Entity.getDecl() && 4934 isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext())) 4935 return Sema::AA_Sending; 4936 4937 return !Diagnose ? Sema::AA_Passing : Sema::AA_Passing_CFAudited; 4938 4939 case InitializedEntity::EK_Result: 4940 return Sema::AA_Returning; 4941 4942 case InitializedEntity::EK_Temporary: 4943 case InitializedEntity::EK_RelatedResult: 4944 // FIXME: Can we tell apart casting vs. converting? 4945 return Sema::AA_Casting; 4946 4947 case InitializedEntity::EK_Member: 4948 case InitializedEntity::EK_ArrayElement: 4949 case InitializedEntity::EK_VectorElement: 4950 case InitializedEntity::EK_ComplexElement: 4951 case InitializedEntity::EK_BlockElement: 4952 case InitializedEntity::EK_LambdaCapture: 4953 case InitializedEntity::EK_CompoundLiteralInit: 4954 return Sema::AA_Initializing; 4955 } 4956 4957 llvm_unreachable("Invalid EntityKind!"); 4958 } 4959 4960 /// \brief Whether we should bind a created object as a temporary when 4961 /// initializing the given entity. 4962 static bool shouldBindAsTemporary(const InitializedEntity &Entity) { 4963 switch (Entity.getKind()) { 4964 case InitializedEntity::EK_ArrayElement: 4965 case InitializedEntity::EK_Member: 4966 case InitializedEntity::EK_Result: 4967 case InitializedEntity::EK_New: 4968 case InitializedEntity::EK_Variable: 4969 case InitializedEntity::EK_Base: 4970 case InitializedEntity::EK_Delegating: 4971 case InitializedEntity::EK_VectorElement: 4972 case InitializedEntity::EK_ComplexElement: 4973 case InitializedEntity::EK_Exception: 4974 case InitializedEntity::EK_BlockElement: 4975 case InitializedEntity::EK_LambdaCapture: 4976 case InitializedEntity::EK_CompoundLiteralInit: 4977 return false; 4978 4979 case InitializedEntity::EK_Parameter: 4980 case InitializedEntity::EK_Parameter_CF_Audited: 4981 case InitializedEntity::EK_Temporary: 4982 case InitializedEntity::EK_RelatedResult: 4983 return true; 4984 } 4985 4986 llvm_unreachable("missed an InitializedEntity kind?"); 4987 } 4988 4989 /// \brief Whether the given entity, when initialized with an object 4990 /// created for that initialization, requires destruction. 4991 static bool shouldDestroyTemporary(const InitializedEntity &Entity) { 4992 switch (Entity.getKind()) { 4993 case InitializedEntity::EK_Result: 4994 case InitializedEntity::EK_New: 4995 case InitializedEntity::EK_Base: 4996 case InitializedEntity::EK_Delegating: 4997 case InitializedEntity::EK_VectorElement: 4998 case InitializedEntity::EK_ComplexElement: 4999 case InitializedEntity::EK_BlockElement: 5000 case InitializedEntity::EK_LambdaCapture: 5001 return false; 5002 5003 case InitializedEntity::EK_Member: 5004 case InitializedEntity::EK_Variable: 5005 case InitializedEntity::EK_Parameter: 5006 case InitializedEntity::EK_Parameter_CF_Audited: 5007 case InitializedEntity::EK_Temporary: 5008 case InitializedEntity::EK_ArrayElement: 5009 case InitializedEntity::EK_Exception: 5010 case InitializedEntity::EK_CompoundLiteralInit: 5011 case InitializedEntity::EK_RelatedResult: 5012 return true; 5013 } 5014 5015 llvm_unreachable("missed an InitializedEntity kind?"); 5016 } 5017 5018 /// \brief Look for copy and move constructors and constructor templates, for 5019 /// copying an object via direct-initialization (per C++11 [dcl.init]p16). 5020 static void LookupCopyAndMoveConstructors(Sema &S, 5021 OverloadCandidateSet &CandidateSet, 5022 CXXRecordDecl *Class, 5023 Expr *CurInitExpr) { 5024 DeclContext::lookup_result R = S.LookupConstructors(Class); 5025 // The container holding the constructors can under certain conditions 5026 // be changed while iterating (e.g. because of deserialization). 5027 // To be safe we copy the lookup results to a new container. 5028 SmallVector<NamedDecl*, 16> Ctors(R.begin(), R.end()); 5029 for (SmallVectorImpl<NamedDecl *>::iterator 5030 CI = Ctors.begin(), CE = Ctors.end(); CI != CE; ++CI) { 5031 NamedDecl *D = *CI; 5032 CXXConstructorDecl *Constructor = nullptr; 5033 5034 if ((Constructor = dyn_cast<CXXConstructorDecl>(D))) { 5035 // Handle copy/moveconstructors, only. 5036 if (!Constructor || Constructor->isInvalidDecl() || 5037 !Constructor->isCopyOrMoveConstructor() || 5038 !Constructor->isConvertingConstructor(/*AllowExplicit=*/true)) 5039 continue; 5040 5041 DeclAccessPair FoundDecl 5042 = DeclAccessPair::make(Constructor, Constructor->getAccess()); 5043 S.AddOverloadCandidate(Constructor, FoundDecl, 5044 CurInitExpr, CandidateSet); 5045 continue; 5046 } 5047 5048 // Handle constructor templates. 5049 FunctionTemplateDecl *ConstructorTmpl = cast<FunctionTemplateDecl>(D); 5050 if (ConstructorTmpl->isInvalidDecl()) 5051 continue; 5052 5053 Constructor = cast<CXXConstructorDecl>( 5054 ConstructorTmpl->getTemplatedDecl()); 5055 if (!Constructor->isConvertingConstructor(/*AllowExplicit=*/true)) 5056 continue; 5057 5058 // FIXME: Do we need to limit this to copy-constructor-like 5059 // candidates? 5060 DeclAccessPair FoundDecl 5061 = DeclAccessPair::make(ConstructorTmpl, ConstructorTmpl->getAccess()); 5062 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, nullptr, 5063 CurInitExpr, CandidateSet, true); 5064 } 5065 } 5066 5067 /// \brief Get the location at which initialization diagnostics should appear. 5068 static SourceLocation getInitializationLoc(const InitializedEntity &Entity, 5069 Expr *Initializer) { 5070 switch (Entity.getKind()) { 5071 case InitializedEntity::EK_Result: 5072 return Entity.getReturnLoc(); 5073 5074 case InitializedEntity::EK_Exception: 5075 return Entity.getThrowLoc(); 5076 5077 case InitializedEntity::EK_Variable: 5078 return Entity.getDecl()->getLocation(); 5079 5080 case InitializedEntity::EK_LambdaCapture: 5081 return Entity.getCaptureLoc(); 5082 5083 case InitializedEntity::EK_ArrayElement: 5084 case InitializedEntity::EK_Member: 5085 case InitializedEntity::EK_Parameter: 5086 case InitializedEntity::EK_Parameter_CF_Audited: 5087 case InitializedEntity::EK_Temporary: 5088 case InitializedEntity::EK_New: 5089 case InitializedEntity::EK_Base: 5090 case InitializedEntity::EK_Delegating: 5091 case InitializedEntity::EK_VectorElement: 5092 case InitializedEntity::EK_ComplexElement: 5093 case InitializedEntity::EK_BlockElement: 5094 case InitializedEntity::EK_CompoundLiteralInit: 5095 case InitializedEntity::EK_RelatedResult: 5096 return Initializer->getLocStart(); 5097 } 5098 llvm_unreachable("missed an InitializedEntity kind?"); 5099 } 5100 5101 /// \brief Make a (potentially elidable) temporary copy of the object 5102 /// provided by the given initializer by calling the appropriate copy 5103 /// constructor. 5104 /// 5105 /// \param S The Sema object used for type-checking. 5106 /// 5107 /// \param T The type of the temporary object, which must either be 5108 /// the type of the initializer expression or a superclass thereof. 5109 /// 5110 /// \param Entity The entity being initialized. 5111 /// 5112 /// \param CurInit The initializer expression. 5113 /// 5114 /// \param IsExtraneousCopy Whether this is an "extraneous" copy that 5115 /// is permitted in C++03 (but not C++0x) when binding a reference to 5116 /// an rvalue. 5117 /// 5118 /// \returns An expression that copies the initializer expression into 5119 /// a temporary object, or an error expression if a copy could not be 5120 /// created. 5121 static ExprResult CopyObject(Sema &S, 5122 QualType T, 5123 const InitializedEntity &Entity, 5124 ExprResult CurInit, 5125 bool IsExtraneousCopy) { 5126 if (CurInit.isInvalid()) 5127 return CurInit; 5128 // Determine which class type we're copying to. 5129 Expr *CurInitExpr = (Expr *)CurInit.get(); 5130 CXXRecordDecl *Class = nullptr; 5131 if (const RecordType *Record = T->getAs<RecordType>()) 5132 Class = cast<CXXRecordDecl>(Record->getDecl()); 5133 if (!Class) 5134 return CurInit; 5135 5136 // C++0x [class.copy]p32: 5137 // When certain criteria are met, an implementation is allowed to 5138 // omit the copy/move construction of a class object, even if the 5139 // copy/move constructor and/or destructor for the object have 5140 // side effects. [...] 5141 // - when a temporary class object that has not been bound to a 5142 // reference (12.2) would be copied/moved to a class object 5143 // with the same cv-unqualified type, the copy/move operation 5144 // can be omitted by constructing the temporary object 5145 // directly into the target of the omitted copy/move 5146 // 5147 // Note that the other three bullets are handled elsewhere. Copy 5148 // elision for return statements and throw expressions are handled as part 5149 // of constructor initialization, while copy elision for exception handlers 5150 // is handled by the run-time. 5151 bool Elidable = CurInitExpr->isTemporaryObject(S.Context, Class); 5152 SourceLocation Loc = getInitializationLoc(Entity, CurInit.get()); 5153 5154 // Make sure that the type we are copying is complete. 5155 if (S.RequireCompleteType(Loc, T, diag::err_temp_copy_incomplete)) 5156 return CurInit; 5157 5158 // Perform overload resolution using the class's copy/move constructors. 5159 // Only consider constructors and constructor templates. Per 5160 // C++0x [dcl.init]p16, second bullet to class types, this initialization 5161 // is direct-initialization. 5162 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal); 5163 LookupCopyAndMoveConstructors(S, CandidateSet, Class, CurInitExpr); 5164 5165 bool HadMultipleCandidates = (CandidateSet.size() > 1); 5166 5167 OverloadCandidateSet::iterator Best; 5168 switch (CandidateSet.BestViableFunction(S, Loc, Best)) { 5169 case OR_Success: 5170 break; 5171 5172 case OR_No_Viable_Function: 5173 S.Diag(Loc, IsExtraneousCopy && !S.isSFINAEContext() 5174 ? diag::ext_rvalue_to_reference_temp_copy_no_viable 5175 : diag::err_temp_copy_no_viable) 5176 << (int)Entity.getKind() << CurInitExpr->getType() 5177 << CurInitExpr->getSourceRange(); 5178 CandidateSet.NoteCandidates(S, OCD_AllCandidates, CurInitExpr); 5179 if (!IsExtraneousCopy || S.isSFINAEContext()) 5180 return ExprError(); 5181 return CurInit; 5182 5183 case OR_Ambiguous: 5184 S.Diag(Loc, diag::err_temp_copy_ambiguous) 5185 << (int)Entity.getKind() << CurInitExpr->getType() 5186 << CurInitExpr->getSourceRange(); 5187 CandidateSet.NoteCandidates(S, OCD_ViableCandidates, CurInitExpr); 5188 return ExprError(); 5189 5190 case OR_Deleted: 5191 S.Diag(Loc, diag::err_temp_copy_deleted) 5192 << (int)Entity.getKind() << CurInitExpr->getType() 5193 << CurInitExpr->getSourceRange(); 5194 S.NoteDeletedFunction(Best->Function); 5195 return ExprError(); 5196 } 5197 5198 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function); 5199 SmallVector<Expr*, 8> ConstructorArgs; 5200 CurInit.get(); // Ownership transferred into MultiExprArg, below. 5201 5202 S.CheckConstructorAccess(Loc, Constructor, Entity, 5203 Best->FoundDecl.getAccess(), IsExtraneousCopy); 5204 5205 if (IsExtraneousCopy) { 5206 // If this is a totally extraneous copy for C++03 reference 5207 // binding purposes, just return the original initialization 5208 // expression. We don't generate an (elided) copy operation here 5209 // because doing so would require us to pass down a flag to avoid 5210 // infinite recursion, where each step adds another extraneous, 5211 // elidable copy. 5212 5213 // Instantiate the default arguments of any extra parameters in 5214 // the selected copy constructor, as if we were going to create a 5215 // proper call to the copy constructor. 5216 for (unsigned I = 1, N = Constructor->getNumParams(); I != N; ++I) { 5217 ParmVarDecl *Parm = Constructor->getParamDecl(I); 5218 if (S.RequireCompleteType(Loc, Parm->getType(), 5219 diag::err_call_incomplete_argument)) 5220 break; 5221 5222 // Build the default argument expression; we don't actually care 5223 // if this succeeds or not, because this routine will complain 5224 // if there was a problem. 5225 S.BuildCXXDefaultArgExpr(Loc, Constructor, Parm); 5226 } 5227 5228 return CurInitExpr; 5229 } 5230 5231 // Determine the arguments required to actually perform the 5232 // constructor call (we might have derived-to-base conversions, or 5233 // the copy constructor may have default arguments). 5234 if (S.CompleteConstructorCall(Constructor, CurInitExpr, Loc, ConstructorArgs)) 5235 return ExprError(); 5236 5237 // Actually perform the constructor call. 5238 CurInit = S.BuildCXXConstructExpr(Loc, T, Constructor, Elidable, 5239 ConstructorArgs, 5240 HadMultipleCandidates, 5241 /*ListInit*/ false, 5242 /*StdInitListInit*/ false, 5243 /*ZeroInit*/ false, 5244 CXXConstructExpr::CK_Complete, 5245 SourceRange()); 5246 5247 // If we're supposed to bind temporaries, do so. 5248 if (!CurInit.isInvalid() && shouldBindAsTemporary(Entity)) 5249 CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>()); 5250 return CurInit; 5251 } 5252 5253 /// \brief Check whether elidable copy construction for binding a reference to 5254 /// a temporary would have succeeded if we were building in C++98 mode, for 5255 /// -Wc++98-compat. 5256 static void CheckCXX98CompatAccessibleCopy(Sema &S, 5257 const InitializedEntity &Entity, 5258 Expr *CurInitExpr) { 5259 assert(S.getLangOpts().CPlusPlus11); 5260 5261 const RecordType *Record = CurInitExpr->getType()->getAs<RecordType>(); 5262 if (!Record) 5263 return; 5264 5265 SourceLocation Loc = getInitializationLoc(Entity, CurInitExpr); 5266 if (S.Diags.isIgnored(diag::warn_cxx98_compat_temp_copy, Loc)) 5267 return; 5268 5269 // Find constructors which would have been considered. 5270 OverloadCandidateSet CandidateSet(Loc, OverloadCandidateSet::CSK_Normal); 5271 LookupCopyAndMoveConstructors( 5272 S, CandidateSet, cast<CXXRecordDecl>(Record->getDecl()), CurInitExpr); 5273 5274 // Perform overload resolution. 5275 OverloadCandidateSet::iterator Best; 5276 OverloadingResult OR = CandidateSet.BestViableFunction(S, Loc, Best); 5277 5278 PartialDiagnostic Diag = S.PDiag(diag::warn_cxx98_compat_temp_copy) 5279 << OR << (int)Entity.getKind() << CurInitExpr->getType() 5280 << CurInitExpr->getSourceRange(); 5281 5282 switch (OR) { 5283 case OR_Success: 5284 S.CheckConstructorAccess(Loc, cast<CXXConstructorDecl>(Best->Function), 5285 Entity, Best->FoundDecl.getAccess(), Diag); 5286 // FIXME: Check default arguments as far as that's possible. 5287 break; 5288 5289 case OR_No_Viable_Function: 5290 S.Diag(Loc, Diag); 5291 CandidateSet.NoteCandidates(S, OCD_AllCandidates, CurInitExpr); 5292 break; 5293 5294 case OR_Ambiguous: 5295 S.Diag(Loc, Diag); 5296 CandidateSet.NoteCandidates(S, OCD_ViableCandidates, CurInitExpr); 5297 break; 5298 5299 case OR_Deleted: 5300 S.Diag(Loc, Diag); 5301 S.NoteDeletedFunction(Best->Function); 5302 break; 5303 } 5304 } 5305 5306 void InitializationSequence::PrintInitLocationNote(Sema &S, 5307 const InitializedEntity &Entity) { 5308 if (Entity.isParameterKind() && Entity.getDecl()) { 5309 if (Entity.getDecl()->getLocation().isInvalid()) 5310 return; 5311 5312 if (Entity.getDecl()->getDeclName()) 5313 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_named_here) 5314 << Entity.getDecl()->getDeclName(); 5315 else 5316 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_here); 5317 } 5318 else if (Entity.getKind() == InitializedEntity::EK_RelatedResult && 5319 Entity.getMethodDecl()) 5320 S.Diag(Entity.getMethodDecl()->getLocation(), 5321 diag::note_method_return_type_change) 5322 << Entity.getMethodDecl()->getDeclName(); 5323 } 5324 5325 static bool isReferenceBinding(const InitializationSequence::Step &s) { 5326 return s.Kind == InitializationSequence::SK_BindReference || 5327 s.Kind == InitializationSequence::SK_BindReferenceToTemporary; 5328 } 5329 5330 /// Returns true if the parameters describe a constructor initialization of 5331 /// an explicit temporary object, e.g. "Point(x, y)". 5332 static bool isExplicitTemporary(const InitializedEntity &Entity, 5333 const InitializationKind &Kind, 5334 unsigned NumArgs) { 5335 switch (Entity.getKind()) { 5336 case InitializedEntity::EK_Temporary: 5337 case InitializedEntity::EK_CompoundLiteralInit: 5338 case InitializedEntity::EK_RelatedResult: 5339 break; 5340 default: 5341 return false; 5342 } 5343 5344 switch (Kind.getKind()) { 5345 case InitializationKind::IK_DirectList: 5346 return true; 5347 // FIXME: Hack to work around cast weirdness. 5348 case InitializationKind::IK_Direct: 5349 case InitializationKind::IK_Value: 5350 return NumArgs != 1; 5351 default: 5352 return false; 5353 } 5354 } 5355 5356 static ExprResult 5357 PerformConstructorInitialization(Sema &S, 5358 const InitializedEntity &Entity, 5359 const InitializationKind &Kind, 5360 MultiExprArg Args, 5361 const InitializationSequence::Step& Step, 5362 bool &ConstructorInitRequiresZeroInit, 5363 bool IsListInitialization, 5364 bool IsStdInitListInitialization, 5365 SourceLocation LBraceLoc, 5366 SourceLocation RBraceLoc) { 5367 unsigned NumArgs = Args.size(); 5368 CXXConstructorDecl *Constructor 5369 = cast<CXXConstructorDecl>(Step.Function.Function); 5370 bool HadMultipleCandidates = Step.Function.HadMultipleCandidates; 5371 5372 // Build a call to the selected constructor. 5373 SmallVector<Expr*, 8> ConstructorArgs; 5374 SourceLocation Loc = (Kind.isCopyInit() && Kind.getEqualLoc().isValid()) 5375 ? Kind.getEqualLoc() 5376 : Kind.getLocation(); 5377 5378 if (Kind.getKind() == InitializationKind::IK_Default) { 5379 // Force even a trivial, implicit default constructor to be 5380 // semantically checked. We do this explicitly because we don't build 5381 // the definition for completely trivial constructors. 5382 assert(Constructor->getParent() && "No parent class for constructor."); 5383 if (Constructor->isDefaulted() && Constructor->isDefaultConstructor() && 5384 Constructor->isTrivial() && !Constructor->isUsed(false)) 5385 S.DefineImplicitDefaultConstructor(Loc, Constructor); 5386 } 5387 5388 ExprResult CurInit((Expr *)nullptr); 5389 5390 // C++ [over.match.copy]p1: 5391 // - When initializing a temporary to be bound to the first parameter 5392 // of a constructor that takes a reference to possibly cv-qualified 5393 // T as its first argument, called with a single argument in the 5394 // context of direct-initialization, explicit conversion functions 5395 // are also considered. 5396 bool AllowExplicitConv = Kind.AllowExplicit() && !Kind.isCopyInit() && 5397 Args.size() == 1 && 5398 Constructor->isCopyOrMoveConstructor(); 5399 5400 // Determine the arguments required to actually perform the constructor 5401 // call. 5402 if (S.CompleteConstructorCall(Constructor, Args, 5403 Loc, ConstructorArgs, 5404 AllowExplicitConv, 5405 IsListInitialization)) 5406 return ExprError(); 5407 5408 5409 if (isExplicitTemporary(Entity, Kind, NumArgs)) { 5410 // An explicitly-constructed temporary, e.g., X(1, 2). 5411 S.MarkFunctionReferenced(Loc, Constructor); 5412 if (S.DiagnoseUseOfDecl(Constructor, Loc)) 5413 return ExprError(); 5414 5415 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo(); 5416 if (!TSInfo) 5417 TSInfo = S.Context.getTrivialTypeSourceInfo(Entity.getType(), Loc); 5418 SourceRange ParenOrBraceRange = 5419 (Kind.getKind() == InitializationKind::IK_DirectList) 5420 ? SourceRange(LBraceLoc, RBraceLoc) 5421 : Kind.getParenRange(); 5422 5423 CurInit = new (S.Context) CXXTemporaryObjectExpr( 5424 S.Context, Constructor, TSInfo, ConstructorArgs, ParenOrBraceRange, 5425 HadMultipleCandidates, IsListInitialization, 5426 IsStdInitListInitialization, ConstructorInitRequiresZeroInit); 5427 } else { 5428 CXXConstructExpr::ConstructionKind ConstructKind = 5429 CXXConstructExpr::CK_Complete; 5430 5431 if (Entity.getKind() == InitializedEntity::EK_Base) { 5432 ConstructKind = Entity.getBaseSpecifier()->isVirtual() ? 5433 CXXConstructExpr::CK_VirtualBase : 5434 CXXConstructExpr::CK_NonVirtualBase; 5435 } else if (Entity.getKind() == InitializedEntity::EK_Delegating) { 5436 ConstructKind = CXXConstructExpr::CK_Delegating; 5437 } 5438 5439 // Only get the parenthesis or brace range if it is a list initialization or 5440 // direct construction. 5441 SourceRange ParenOrBraceRange; 5442 if (IsListInitialization) 5443 ParenOrBraceRange = SourceRange(LBraceLoc, RBraceLoc); 5444 else if (Kind.getKind() == InitializationKind::IK_Direct) 5445 ParenOrBraceRange = Kind.getParenRange(); 5446 5447 // If the entity allows NRVO, mark the construction as elidable 5448 // unconditionally. 5449 if (Entity.allowsNRVO()) 5450 CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(), 5451 Constructor, /*Elidable=*/true, 5452 ConstructorArgs, 5453 HadMultipleCandidates, 5454 IsListInitialization, 5455 IsStdInitListInitialization, 5456 ConstructorInitRequiresZeroInit, 5457 ConstructKind, 5458 ParenOrBraceRange); 5459 else 5460 CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(), 5461 Constructor, 5462 ConstructorArgs, 5463 HadMultipleCandidates, 5464 IsListInitialization, 5465 IsStdInitListInitialization, 5466 ConstructorInitRequiresZeroInit, 5467 ConstructKind, 5468 ParenOrBraceRange); 5469 } 5470 if (CurInit.isInvalid()) 5471 return ExprError(); 5472 5473 // Only check access if all of that succeeded. 5474 S.CheckConstructorAccess(Loc, Constructor, Entity, 5475 Step.Function.FoundDecl.getAccess()); 5476 if (S.DiagnoseUseOfDecl(Step.Function.FoundDecl, Loc)) 5477 return ExprError(); 5478 5479 if (shouldBindAsTemporary(Entity)) 5480 CurInit = S.MaybeBindToTemporary(CurInit.get()); 5481 5482 return CurInit; 5483 } 5484 5485 /// Determine whether the specified InitializedEntity definitely has a lifetime 5486 /// longer than the current full-expression. Conservatively returns false if 5487 /// it's unclear. 5488 static bool 5489 InitializedEntityOutlivesFullExpression(const InitializedEntity &Entity) { 5490 const InitializedEntity *Top = &Entity; 5491 while (Top->getParent()) 5492 Top = Top->getParent(); 5493 5494 switch (Top->getKind()) { 5495 case InitializedEntity::EK_Variable: 5496 case InitializedEntity::EK_Result: 5497 case InitializedEntity::EK_Exception: 5498 case InitializedEntity::EK_Member: 5499 case InitializedEntity::EK_New: 5500 case InitializedEntity::EK_Base: 5501 case InitializedEntity::EK_Delegating: 5502 return true; 5503 5504 case InitializedEntity::EK_ArrayElement: 5505 case InitializedEntity::EK_VectorElement: 5506 case InitializedEntity::EK_BlockElement: 5507 case InitializedEntity::EK_ComplexElement: 5508 // Could not determine what the full initialization is. Assume it might not 5509 // outlive the full-expression. 5510 return false; 5511 5512 case InitializedEntity::EK_Parameter: 5513 case InitializedEntity::EK_Parameter_CF_Audited: 5514 case InitializedEntity::EK_Temporary: 5515 case InitializedEntity::EK_LambdaCapture: 5516 case InitializedEntity::EK_CompoundLiteralInit: 5517 case InitializedEntity::EK_RelatedResult: 5518 // The entity being initialized might not outlive the full-expression. 5519 return false; 5520 } 5521 5522 llvm_unreachable("unknown entity kind"); 5523 } 5524 5525 /// Determine the declaration which an initialized entity ultimately refers to, 5526 /// for the purpose of lifetime-extending a temporary bound to a reference in 5527 /// the initialization of \p Entity. 5528 static const InitializedEntity *getEntityForTemporaryLifetimeExtension( 5529 const InitializedEntity *Entity, 5530 const InitializedEntity *FallbackDecl = nullptr) { 5531 // C++11 [class.temporary]p5: 5532 switch (Entity->getKind()) { 5533 case InitializedEntity::EK_Variable: 5534 // The temporary [...] persists for the lifetime of the reference 5535 return Entity; 5536 5537 case InitializedEntity::EK_Member: 5538 // For subobjects, we look at the complete object. 5539 if (Entity->getParent()) 5540 return getEntityForTemporaryLifetimeExtension(Entity->getParent(), 5541 Entity); 5542 5543 // except: 5544 // -- A temporary bound to a reference member in a constructor's 5545 // ctor-initializer persists until the constructor exits. 5546 return Entity; 5547 5548 case InitializedEntity::EK_Parameter: 5549 case InitializedEntity::EK_Parameter_CF_Audited: 5550 // -- A temporary bound to a reference parameter in a function call 5551 // persists until the completion of the full-expression containing 5552 // the call. 5553 case InitializedEntity::EK_Result: 5554 // -- The lifetime of a temporary bound to the returned value in a 5555 // function return statement is not extended; the temporary is 5556 // destroyed at the end of the full-expression in the return statement. 5557 case InitializedEntity::EK_New: 5558 // -- A temporary bound to a reference in a new-initializer persists 5559 // until the completion of the full-expression containing the 5560 // new-initializer. 5561 return nullptr; 5562 5563 case InitializedEntity::EK_Temporary: 5564 case InitializedEntity::EK_CompoundLiteralInit: 5565 case InitializedEntity::EK_RelatedResult: 5566 // We don't yet know the storage duration of the surrounding temporary. 5567 // Assume it's got full-expression duration for now, it will patch up our 5568 // storage duration if that's not correct. 5569 return nullptr; 5570 5571 case InitializedEntity::EK_ArrayElement: 5572 // For subobjects, we look at the complete object. 5573 return getEntityForTemporaryLifetimeExtension(Entity->getParent(), 5574 FallbackDecl); 5575 5576 case InitializedEntity::EK_Base: 5577 case InitializedEntity::EK_Delegating: 5578 // We can reach this case for aggregate initialization in a constructor: 5579 // struct A { int &&r; }; 5580 // struct B : A { B() : A{0} {} }; 5581 // In this case, use the innermost field decl as the context. 5582 return FallbackDecl; 5583 5584 case InitializedEntity::EK_BlockElement: 5585 case InitializedEntity::EK_LambdaCapture: 5586 case InitializedEntity::EK_Exception: 5587 case InitializedEntity::EK_VectorElement: 5588 case InitializedEntity::EK_ComplexElement: 5589 return nullptr; 5590 } 5591 llvm_unreachable("unknown entity kind"); 5592 } 5593 5594 static void performLifetimeExtension(Expr *Init, 5595 const InitializedEntity *ExtendingEntity); 5596 5597 /// Update a glvalue expression that is used as the initializer of a reference 5598 /// to note that its lifetime is extended. 5599 /// \return \c true if any temporary had its lifetime extended. 5600 static bool 5601 performReferenceExtension(Expr *Init, 5602 const InitializedEntity *ExtendingEntity) { 5603 // Walk past any constructs which we can lifetime-extend across. 5604 Expr *Old; 5605 do { 5606 Old = Init; 5607 5608 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) { 5609 if (ILE->getNumInits() == 1 && ILE->isGLValue()) { 5610 // This is just redundant braces around an initializer. Step over it. 5611 Init = ILE->getInit(0); 5612 } 5613 } 5614 5615 // Step over any subobject adjustments; we may have a materialized 5616 // temporary inside them. 5617 SmallVector<const Expr *, 2> CommaLHSs; 5618 SmallVector<SubobjectAdjustment, 2> Adjustments; 5619 Init = const_cast<Expr *>( 5620 Init->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments)); 5621 5622 // Per current approach for DR1376, look through casts to reference type 5623 // when performing lifetime extension. 5624 if (CastExpr *CE = dyn_cast<CastExpr>(Init)) 5625 if (CE->getSubExpr()->isGLValue()) 5626 Init = CE->getSubExpr(); 5627 5628 // FIXME: Per DR1213, subscripting on an array temporary produces an xvalue. 5629 // It's unclear if binding a reference to that xvalue extends the array 5630 // temporary. 5631 } while (Init != Old); 5632 5633 if (MaterializeTemporaryExpr *ME = dyn_cast<MaterializeTemporaryExpr>(Init)) { 5634 // Update the storage duration of the materialized temporary. 5635 // FIXME: Rebuild the expression instead of mutating it. 5636 ME->setExtendingDecl(ExtendingEntity->getDecl(), 5637 ExtendingEntity->allocateManglingNumber()); 5638 performLifetimeExtension(ME->GetTemporaryExpr(), ExtendingEntity); 5639 return true; 5640 } 5641 5642 return false; 5643 } 5644 5645 /// Update a prvalue expression that is going to be materialized as a 5646 /// lifetime-extended temporary. 5647 static void performLifetimeExtension(Expr *Init, 5648 const InitializedEntity *ExtendingEntity) { 5649 // Dig out the expression which constructs the extended temporary. 5650 SmallVector<const Expr *, 2> CommaLHSs; 5651 SmallVector<SubobjectAdjustment, 2> Adjustments; 5652 Init = const_cast<Expr *>( 5653 Init->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments)); 5654 5655 if (CXXBindTemporaryExpr *BTE = dyn_cast<CXXBindTemporaryExpr>(Init)) 5656 Init = BTE->getSubExpr(); 5657 5658 if (CXXStdInitializerListExpr *ILE = 5659 dyn_cast<CXXStdInitializerListExpr>(Init)) { 5660 performReferenceExtension(ILE->getSubExpr(), ExtendingEntity); 5661 return; 5662 } 5663 5664 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) { 5665 if (ILE->getType()->isArrayType()) { 5666 for (unsigned I = 0, N = ILE->getNumInits(); I != N; ++I) 5667 performLifetimeExtension(ILE->getInit(I), ExtendingEntity); 5668 return; 5669 } 5670 5671 if (CXXRecordDecl *RD = ILE->getType()->getAsCXXRecordDecl()) { 5672 assert(RD->isAggregate() && "aggregate init on non-aggregate"); 5673 5674 // If we lifetime-extend a braced initializer which is initializing an 5675 // aggregate, and that aggregate contains reference members which are 5676 // bound to temporaries, those temporaries are also lifetime-extended. 5677 if (RD->isUnion() && ILE->getInitializedFieldInUnion() && 5678 ILE->getInitializedFieldInUnion()->getType()->isReferenceType()) 5679 performReferenceExtension(ILE->getInit(0), ExtendingEntity); 5680 else { 5681 unsigned Index = 0; 5682 for (const auto *I : RD->fields()) { 5683 if (Index >= ILE->getNumInits()) 5684 break; 5685 if (I->isUnnamedBitfield()) 5686 continue; 5687 Expr *SubInit = ILE->getInit(Index); 5688 if (I->getType()->isReferenceType()) 5689 performReferenceExtension(SubInit, ExtendingEntity); 5690 else if (isa<InitListExpr>(SubInit) || 5691 isa<CXXStdInitializerListExpr>(SubInit)) 5692 // This may be either aggregate-initialization of a member or 5693 // initialization of a std::initializer_list object. Either way, 5694 // we should recursively lifetime-extend that initializer. 5695 performLifetimeExtension(SubInit, ExtendingEntity); 5696 ++Index; 5697 } 5698 } 5699 } 5700 } 5701 } 5702 5703 static void warnOnLifetimeExtension(Sema &S, const InitializedEntity &Entity, 5704 const Expr *Init, bool IsInitializerList, 5705 const ValueDecl *ExtendingDecl) { 5706 // Warn if a field lifetime-extends a temporary. 5707 if (isa<FieldDecl>(ExtendingDecl)) { 5708 if (IsInitializerList) { 5709 S.Diag(Init->getExprLoc(), diag::warn_dangling_std_initializer_list) 5710 << /*at end of constructor*/true; 5711 return; 5712 } 5713 5714 bool IsSubobjectMember = false; 5715 for (const InitializedEntity *Ent = Entity.getParent(); Ent; 5716 Ent = Ent->getParent()) { 5717 if (Ent->getKind() != InitializedEntity::EK_Base) { 5718 IsSubobjectMember = true; 5719 break; 5720 } 5721 } 5722 S.Diag(Init->getExprLoc(), 5723 diag::warn_bind_ref_member_to_temporary) 5724 << ExtendingDecl << Init->getSourceRange() 5725 << IsSubobjectMember << IsInitializerList; 5726 if (IsSubobjectMember) 5727 S.Diag(ExtendingDecl->getLocation(), 5728 diag::note_ref_subobject_of_member_declared_here); 5729 else 5730 S.Diag(ExtendingDecl->getLocation(), 5731 diag::note_ref_or_ptr_member_declared_here) 5732 << /*is pointer*/false; 5733 } 5734 } 5735 5736 static void DiagnoseNarrowingInInitList(Sema &S, 5737 const ImplicitConversionSequence &ICS, 5738 QualType PreNarrowingType, 5739 QualType EntityType, 5740 const Expr *PostInit); 5741 5742 ExprResult 5743 InitializationSequence::Perform(Sema &S, 5744 const InitializedEntity &Entity, 5745 const InitializationKind &Kind, 5746 MultiExprArg Args, 5747 QualType *ResultType) { 5748 if (Failed()) { 5749 Diagnose(S, Entity, Kind, Args); 5750 return ExprError(); 5751 } 5752 5753 if (getKind() == DependentSequence) { 5754 // If the declaration is a non-dependent, incomplete array type 5755 // that has an initializer, then its type will be completed once 5756 // the initializer is instantiated. 5757 if (ResultType && !Entity.getType()->isDependentType() && 5758 Args.size() == 1) { 5759 QualType DeclType = Entity.getType(); 5760 if (const IncompleteArrayType *ArrayT 5761 = S.Context.getAsIncompleteArrayType(DeclType)) { 5762 // FIXME: We don't currently have the ability to accurately 5763 // compute the length of an initializer list without 5764 // performing full type-checking of the initializer list 5765 // (since we have to determine where braces are implicitly 5766 // introduced and such). So, we fall back to making the array 5767 // type a dependently-sized array type with no specified 5768 // bound. 5769 if (isa<InitListExpr>((Expr *)Args[0])) { 5770 SourceRange Brackets; 5771 5772 // Scavange the location of the brackets from the entity, if we can. 5773 if (DeclaratorDecl *DD = Entity.getDecl()) { 5774 if (TypeSourceInfo *TInfo = DD->getTypeSourceInfo()) { 5775 TypeLoc TL = TInfo->getTypeLoc(); 5776 if (IncompleteArrayTypeLoc ArrayLoc = 5777 TL.getAs<IncompleteArrayTypeLoc>()) 5778 Brackets = ArrayLoc.getBracketsRange(); 5779 } 5780 } 5781 5782 *ResultType 5783 = S.Context.getDependentSizedArrayType(ArrayT->getElementType(), 5784 /*NumElts=*/nullptr, 5785 ArrayT->getSizeModifier(), 5786 ArrayT->getIndexTypeCVRQualifiers(), 5787 Brackets); 5788 } 5789 5790 } 5791 } 5792 if (Kind.getKind() == InitializationKind::IK_Direct && 5793 !Kind.isExplicitCast()) { 5794 // Rebuild the ParenListExpr. 5795 SourceRange ParenRange = Kind.getParenRange(); 5796 return S.ActOnParenListExpr(ParenRange.getBegin(), ParenRange.getEnd(), 5797 Args); 5798 } 5799 assert(Kind.getKind() == InitializationKind::IK_Copy || 5800 Kind.isExplicitCast() || 5801 Kind.getKind() == InitializationKind::IK_DirectList); 5802 return ExprResult(Args[0]); 5803 } 5804 5805 // No steps means no initialization. 5806 if (Steps.empty()) 5807 return ExprResult((Expr *)nullptr); 5808 5809 if (S.getLangOpts().CPlusPlus11 && Entity.getType()->isReferenceType() && 5810 Args.size() == 1 && isa<InitListExpr>(Args[0]) && 5811 !Entity.isParameterKind()) { 5812 // Produce a C++98 compatibility warning if we are initializing a reference 5813 // from an initializer list. For parameters, we produce a better warning 5814 // elsewhere. 5815 Expr *Init = Args[0]; 5816 S.Diag(Init->getLocStart(), diag::warn_cxx98_compat_reference_list_init) 5817 << Init->getSourceRange(); 5818 } 5819 5820 // Diagnose cases where we initialize a pointer to an array temporary, and the 5821 // pointer obviously outlives the temporary. 5822 if (Args.size() == 1 && Args[0]->getType()->isArrayType() && 5823 Entity.getType()->isPointerType() && 5824 InitializedEntityOutlivesFullExpression(Entity)) { 5825 Expr *Init = Args[0]; 5826 Expr::LValueClassification Kind = Init->ClassifyLValue(S.Context); 5827 if (Kind == Expr::LV_ClassTemporary || Kind == Expr::LV_ArrayTemporary) 5828 S.Diag(Init->getLocStart(), diag::warn_temporary_array_to_pointer_decay) 5829 << Init->getSourceRange(); 5830 } 5831 5832 QualType DestType = Entity.getType().getNonReferenceType(); 5833 // FIXME: Ugly hack around the fact that Entity.getType() is not 5834 // the same as Entity.getDecl()->getType() in cases involving type merging, 5835 // and we want latter when it makes sense. 5836 if (ResultType) 5837 *ResultType = Entity.getDecl() ? Entity.getDecl()->getType() : 5838 Entity.getType(); 5839 5840 ExprResult CurInit((Expr *)nullptr); 5841 5842 // For initialization steps that start with a single initializer, 5843 // grab the only argument out the Args and place it into the "current" 5844 // initializer. 5845 switch (Steps.front().Kind) { 5846 case SK_ResolveAddressOfOverloadedFunction: 5847 case SK_CastDerivedToBaseRValue: 5848 case SK_CastDerivedToBaseXValue: 5849 case SK_CastDerivedToBaseLValue: 5850 case SK_BindReference: 5851 case SK_BindReferenceToTemporary: 5852 case SK_ExtraneousCopyToTemporary: 5853 case SK_UserConversion: 5854 case SK_QualificationConversionLValue: 5855 case SK_QualificationConversionXValue: 5856 case SK_QualificationConversionRValue: 5857 case SK_AtomicConversion: 5858 case SK_LValueToRValue: 5859 case SK_ConversionSequence: 5860 case SK_ConversionSequenceNoNarrowing: 5861 case SK_ListInitialization: 5862 case SK_UnwrapInitList: 5863 case SK_RewrapInitList: 5864 case SK_CAssignment: 5865 case SK_StringInit: 5866 case SK_ObjCObjectConversion: 5867 case SK_ArrayInit: 5868 case SK_ParenthesizedArrayInit: 5869 case SK_PassByIndirectCopyRestore: 5870 case SK_PassByIndirectRestore: 5871 case SK_ProduceObjCObject: 5872 case SK_StdInitializerList: 5873 case SK_OCLSamplerInit: 5874 case SK_OCLZeroEvent: { 5875 assert(Args.size() == 1); 5876 CurInit = Args[0]; 5877 if (!CurInit.get()) return ExprError(); 5878 break; 5879 } 5880 5881 case SK_ConstructorInitialization: 5882 case SK_ConstructorInitializationFromList: 5883 case SK_StdInitializerListConstructorCall: 5884 case SK_ZeroInitialization: 5885 break; 5886 } 5887 5888 // Walk through the computed steps for the initialization sequence, 5889 // performing the specified conversions along the way. 5890 bool ConstructorInitRequiresZeroInit = false; 5891 for (step_iterator Step = step_begin(), StepEnd = step_end(); 5892 Step != StepEnd; ++Step) { 5893 if (CurInit.isInvalid()) 5894 return ExprError(); 5895 5896 QualType SourceType = CurInit.get() ? CurInit.get()->getType() : QualType(); 5897 5898 switch (Step->Kind) { 5899 case SK_ResolveAddressOfOverloadedFunction: 5900 // Overload resolution determined which function invoke; update the 5901 // initializer to reflect that choice. 5902 S.CheckAddressOfMemberAccess(CurInit.get(), Step->Function.FoundDecl); 5903 if (S.DiagnoseUseOfDecl(Step->Function.FoundDecl, Kind.getLocation())) 5904 return ExprError(); 5905 CurInit = S.FixOverloadedFunctionReference(CurInit, 5906 Step->Function.FoundDecl, 5907 Step->Function.Function); 5908 break; 5909 5910 case SK_CastDerivedToBaseRValue: 5911 case SK_CastDerivedToBaseXValue: 5912 case SK_CastDerivedToBaseLValue: { 5913 // We have a derived-to-base cast that produces either an rvalue or an 5914 // lvalue. Perform that cast. 5915 5916 CXXCastPath BasePath; 5917 5918 // Casts to inaccessible base classes are allowed with C-style casts. 5919 bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast(); 5920 if (S.CheckDerivedToBaseConversion(SourceType, Step->Type, 5921 CurInit.get()->getLocStart(), 5922 CurInit.get()->getSourceRange(), 5923 &BasePath, IgnoreBaseAccess)) 5924 return ExprError(); 5925 5926 ExprValueKind VK = 5927 Step->Kind == SK_CastDerivedToBaseLValue ? 5928 VK_LValue : 5929 (Step->Kind == SK_CastDerivedToBaseXValue ? 5930 VK_XValue : 5931 VK_RValue); 5932 CurInit = 5933 ImplicitCastExpr::Create(S.Context, Step->Type, CK_DerivedToBase, 5934 CurInit.get(), &BasePath, VK); 5935 break; 5936 } 5937 5938 case SK_BindReference: 5939 // References cannot bind to bit-fields (C++ [dcl.init.ref]p5). 5940 if (CurInit.get()->refersToBitField()) { 5941 // We don't necessarily have an unambiguous source bit-field. 5942 FieldDecl *BitField = CurInit.get()->getSourceBitField(); 5943 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield) 5944 << Entity.getType().isVolatileQualified() 5945 << (BitField ? BitField->getDeclName() : DeclarationName()) 5946 << (BitField != nullptr) 5947 << CurInit.get()->getSourceRange(); 5948 if (BitField) 5949 S.Diag(BitField->getLocation(), diag::note_bitfield_decl); 5950 5951 return ExprError(); 5952 } 5953 5954 if (CurInit.get()->refersToVectorElement()) { 5955 // References cannot bind to vector elements. 5956 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_vector_element) 5957 << Entity.getType().isVolatileQualified() 5958 << CurInit.get()->getSourceRange(); 5959 PrintInitLocationNote(S, Entity); 5960 return ExprError(); 5961 } 5962 5963 // Reference binding does not have any corresponding ASTs. 5964 5965 // Check exception specifications 5966 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType)) 5967 return ExprError(); 5968 5969 // Even though we didn't materialize a temporary, the binding may still 5970 // extend the lifetime of a temporary. This happens if we bind a reference 5971 // to the result of a cast to reference type. 5972 if (const InitializedEntity *ExtendingEntity = 5973 getEntityForTemporaryLifetimeExtension(&Entity)) 5974 if (performReferenceExtension(CurInit.get(), ExtendingEntity)) 5975 warnOnLifetimeExtension(S, Entity, CurInit.get(), 5976 /*IsInitializerList=*/false, 5977 ExtendingEntity->getDecl()); 5978 5979 break; 5980 5981 case SK_BindReferenceToTemporary: { 5982 // Make sure the "temporary" is actually an rvalue. 5983 assert(CurInit.get()->isRValue() && "not a temporary"); 5984 5985 // Check exception specifications 5986 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType)) 5987 return ExprError(); 5988 5989 // Materialize the temporary into memory. 5990 MaterializeTemporaryExpr *MTE = new (S.Context) MaterializeTemporaryExpr( 5991 Entity.getType().getNonReferenceType(), CurInit.get(), 5992 Entity.getType()->isLValueReferenceType()); 5993 5994 // Maybe lifetime-extend the temporary's subobjects to match the 5995 // entity's lifetime. 5996 if (const InitializedEntity *ExtendingEntity = 5997 getEntityForTemporaryLifetimeExtension(&Entity)) 5998 if (performReferenceExtension(MTE, ExtendingEntity)) 5999 warnOnLifetimeExtension(S, Entity, CurInit.get(), /*IsInitializerList=*/false, 6000 ExtendingEntity->getDecl()); 6001 6002 // If we're binding to an Objective-C object that has lifetime, we 6003 // need cleanups. Likewise if we're extending this temporary to automatic 6004 // storage duration -- we need to register its cleanup during the 6005 // full-expression's cleanups. 6006 if ((S.getLangOpts().ObjCAutoRefCount && 6007 MTE->getType()->isObjCLifetimeType()) || 6008 (MTE->getStorageDuration() == SD_Automatic && 6009 MTE->getType().isDestructedType())) 6010 S.ExprNeedsCleanups = true; 6011 6012 CurInit = MTE; 6013 break; 6014 } 6015 6016 case SK_ExtraneousCopyToTemporary: 6017 CurInit = CopyObject(S, Step->Type, Entity, CurInit, 6018 /*IsExtraneousCopy=*/true); 6019 break; 6020 6021 case SK_UserConversion: { 6022 // We have a user-defined conversion that invokes either a constructor 6023 // or a conversion function. 6024 CastKind CastKind; 6025 bool IsCopy = false; 6026 FunctionDecl *Fn = Step->Function.Function; 6027 DeclAccessPair FoundFn = Step->Function.FoundDecl; 6028 bool HadMultipleCandidates = Step->Function.HadMultipleCandidates; 6029 bool CreatedObject = false; 6030 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Fn)) { 6031 // Build a call to the selected constructor. 6032 SmallVector<Expr*, 8> ConstructorArgs; 6033 SourceLocation Loc = CurInit.get()->getLocStart(); 6034 CurInit.get(); // Ownership transferred into MultiExprArg, below. 6035 6036 // Determine the arguments required to actually perform the constructor 6037 // call. 6038 Expr *Arg = CurInit.get(); 6039 if (S.CompleteConstructorCall(Constructor, 6040 MultiExprArg(&Arg, 1), 6041 Loc, ConstructorArgs)) 6042 return ExprError(); 6043 6044 // Build an expression that constructs a temporary. 6045 CurInit = S.BuildCXXConstructExpr(Loc, Step->Type, Constructor, 6046 ConstructorArgs, 6047 HadMultipleCandidates, 6048 /*ListInit*/ false, 6049 /*StdInitListInit*/ false, 6050 /*ZeroInit*/ false, 6051 CXXConstructExpr::CK_Complete, 6052 SourceRange()); 6053 if (CurInit.isInvalid()) 6054 return ExprError(); 6055 6056 S.CheckConstructorAccess(Kind.getLocation(), Constructor, Entity, 6057 FoundFn.getAccess()); 6058 if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation())) 6059 return ExprError(); 6060 6061 CastKind = CK_ConstructorConversion; 6062 QualType Class = S.Context.getTypeDeclType(Constructor->getParent()); 6063 if (S.Context.hasSameUnqualifiedType(SourceType, Class) || 6064 S.IsDerivedFrom(SourceType, Class)) 6065 IsCopy = true; 6066 6067 CreatedObject = true; 6068 } else { 6069 // Build a call to the conversion function. 6070 CXXConversionDecl *Conversion = cast<CXXConversionDecl>(Fn); 6071 S.CheckMemberOperatorAccess(Kind.getLocation(), CurInit.get(), nullptr, 6072 FoundFn); 6073 if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation())) 6074 return ExprError(); 6075 6076 // FIXME: Should we move this initialization into a separate 6077 // derived-to-base conversion? I believe the answer is "no", because 6078 // we don't want to turn off access control here for c-style casts. 6079 ExprResult CurInitExprRes = 6080 S.PerformObjectArgumentInitialization(CurInit.get(), 6081 /*Qualifier=*/nullptr, 6082 FoundFn, Conversion); 6083 if(CurInitExprRes.isInvalid()) 6084 return ExprError(); 6085 CurInit = CurInitExprRes; 6086 6087 // Build the actual call to the conversion function. 6088 CurInit = S.BuildCXXMemberCallExpr(CurInit.get(), FoundFn, Conversion, 6089 HadMultipleCandidates); 6090 if (CurInit.isInvalid() || !CurInit.get()) 6091 return ExprError(); 6092 6093 CastKind = CK_UserDefinedConversion; 6094 6095 CreatedObject = Conversion->getReturnType()->isRecordType(); 6096 } 6097 6098 bool RequiresCopy = !IsCopy && !isReferenceBinding(Steps.back()); 6099 bool MaybeBindToTemp = RequiresCopy || shouldBindAsTemporary(Entity); 6100 6101 if (!MaybeBindToTemp && CreatedObject && shouldDestroyTemporary(Entity)) { 6102 QualType T = CurInit.get()->getType(); 6103 if (const RecordType *Record = T->getAs<RecordType>()) { 6104 CXXDestructorDecl *Destructor 6105 = S.LookupDestructor(cast<CXXRecordDecl>(Record->getDecl())); 6106 S.CheckDestructorAccess(CurInit.get()->getLocStart(), Destructor, 6107 S.PDiag(diag::err_access_dtor_temp) << T); 6108 S.MarkFunctionReferenced(CurInit.get()->getLocStart(), Destructor); 6109 if (S.DiagnoseUseOfDecl(Destructor, CurInit.get()->getLocStart())) 6110 return ExprError(); 6111 } 6112 } 6113 6114 CurInit = ImplicitCastExpr::Create(S.Context, CurInit.get()->getType(), 6115 CastKind, CurInit.get(), nullptr, 6116 CurInit.get()->getValueKind()); 6117 if (MaybeBindToTemp) 6118 CurInit = S.MaybeBindToTemporary(CurInit.getAs<Expr>()); 6119 if (RequiresCopy) 6120 CurInit = CopyObject(S, Entity.getType().getNonReferenceType(), Entity, 6121 CurInit, /*IsExtraneousCopy=*/false); 6122 break; 6123 } 6124 6125 case SK_QualificationConversionLValue: 6126 case SK_QualificationConversionXValue: 6127 case SK_QualificationConversionRValue: { 6128 // Perform a qualification conversion; these can never go wrong. 6129 ExprValueKind VK = 6130 Step->Kind == SK_QualificationConversionLValue ? 6131 VK_LValue : 6132 (Step->Kind == SK_QualificationConversionXValue ? 6133 VK_XValue : 6134 VK_RValue); 6135 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type, CK_NoOp, VK); 6136 break; 6137 } 6138 6139 case SK_AtomicConversion: { 6140 assert(CurInit.get()->isRValue() && "cannot convert glvalue to atomic"); 6141 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type, 6142 CK_NonAtomicToAtomic, VK_RValue); 6143 break; 6144 } 6145 6146 case SK_LValueToRValue: { 6147 assert(CurInit.get()->isGLValue() && "cannot load from a prvalue"); 6148 CurInit = ImplicitCastExpr::Create(S.Context, Step->Type, 6149 CK_LValueToRValue, CurInit.get(), 6150 /*BasePath=*/nullptr, VK_RValue); 6151 break; 6152 } 6153 6154 case SK_ConversionSequence: 6155 case SK_ConversionSequenceNoNarrowing: { 6156 Sema::CheckedConversionKind CCK 6157 = Kind.isCStyleCast()? Sema::CCK_CStyleCast 6158 : Kind.isFunctionalCast()? Sema::CCK_FunctionalCast 6159 : Kind.isExplicitCast()? Sema::CCK_OtherCast 6160 : Sema::CCK_ImplicitConversion; 6161 ExprResult CurInitExprRes = 6162 S.PerformImplicitConversion(CurInit.get(), Step->Type, *Step->ICS, 6163 getAssignmentAction(Entity), CCK); 6164 if (CurInitExprRes.isInvalid()) 6165 return ExprError(); 6166 CurInit = CurInitExprRes; 6167 6168 if (Step->Kind == SK_ConversionSequenceNoNarrowing && 6169 S.getLangOpts().CPlusPlus && !CurInit.get()->isValueDependent()) 6170 DiagnoseNarrowingInInitList(S, *Step->ICS, SourceType, Entity.getType(), 6171 CurInit.get()); 6172 break; 6173 } 6174 6175 case SK_ListInitialization: { 6176 InitListExpr *InitList = cast<InitListExpr>(CurInit.get()); 6177 // If we're not initializing the top-level entity, we need to create an 6178 // InitializeTemporary entity for our target type. 6179 QualType Ty = Step->Type; 6180 bool IsTemporary = !S.Context.hasSameType(Entity.getType(), Ty); 6181 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(Ty); 6182 InitializedEntity InitEntity = IsTemporary ? TempEntity : Entity; 6183 InitListChecker PerformInitList(S, InitEntity, 6184 InitList, Ty, /*VerifyOnly=*/false); 6185 if (PerformInitList.HadError()) 6186 return ExprError(); 6187 6188 // Hack: We must update *ResultType if available in order to set the 6189 // bounds of arrays, e.g. in 'int ar[] = {1, 2, 3};'. 6190 // Worst case: 'const int (&arref)[] = {1, 2, 3};'. 6191 if (ResultType && 6192 ResultType->getNonReferenceType()->isIncompleteArrayType()) { 6193 if ((*ResultType)->isRValueReferenceType()) 6194 Ty = S.Context.getRValueReferenceType(Ty); 6195 else if ((*ResultType)->isLValueReferenceType()) 6196 Ty = S.Context.getLValueReferenceType(Ty, 6197 (*ResultType)->getAs<LValueReferenceType>()->isSpelledAsLValue()); 6198 *ResultType = Ty; 6199 } 6200 6201 InitListExpr *StructuredInitList = 6202 PerformInitList.getFullyStructuredList(); 6203 CurInit.get(); 6204 CurInit = shouldBindAsTemporary(InitEntity) 6205 ? S.MaybeBindToTemporary(StructuredInitList) 6206 : StructuredInitList; 6207 break; 6208 } 6209 6210 case SK_ConstructorInitializationFromList: { 6211 // When an initializer list is passed for a parameter of type "reference 6212 // to object", we don't get an EK_Temporary entity, but instead an 6213 // EK_Parameter entity with reference type. 6214 // FIXME: This is a hack. What we really should do is create a user 6215 // conversion step for this case, but this makes it considerably more 6216 // complicated. For now, this will do. 6217 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary( 6218 Entity.getType().getNonReferenceType()); 6219 bool UseTemporary = Entity.getType()->isReferenceType(); 6220 assert(Args.size() == 1 && "expected a single argument for list init"); 6221 InitListExpr *InitList = cast<InitListExpr>(Args[0]); 6222 S.Diag(InitList->getExprLoc(), diag::warn_cxx98_compat_ctor_list_init) 6223 << InitList->getSourceRange(); 6224 MultiExprArg Arg(InitList->getInits(), InitList->getNumInits()); 6225 CurInit = PerformConstructorInitialization(S, UseTemporary ? TempEntity : 6226 Entity, 6227 Kind, Arg, *Step, 6228 ConstructorInitRequiresZeroInit, 6229 /*IsListInitialization*/true, 6230 /*IsStdInitListInit*/false, 6231 InitList->getLBraceLoc(), 6232 InitList->getRBraceLoc()); 6233 break; 6234 } 6235 6236 case SK_UnwrapInitList: 6237 CurInit = cast<InitListExpr>(CurInit.get())->getInit(0); 6238 break; 6239 6240 case SK_RewrapInitList: { 6241 Expr *E = CurInit.get(); 6242 InitListExpr *Syntactic = Step->WrappingSyntacticList; 6243 InitListExpr *ILE = new (S.Context) InitListExpr(S.Context, 6244 Syntactic->getLBraceLoc(), E, Syntactic->getRBraceLoc()); 6245 ILE->setSyntacticForm(Syntactic); 6246 ILE->setType(E->getType()); 6247 ILE->setValueKind(E->getValueKind()); 6248 CurInit = ILE; 6249 break; 6250 } 6251 6252 case SK_ConstructorInitialization: 6253 case SK_StdInitializerListConstructorCall: { 6254 // When an initializer list is passed for a parameter of type "reference 6255 // to object", we don't get an EK_Temporary entity, but instead an 6256 // EK_Parameter entity with reference type. 6257 // FIXME: This is a hack. What we really should do is create a user 6258 // conversion step for this case, but this makes it considerably more 6259 // complicated. For now, this will do. 6260 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary( 6261 Entity.getType().getNonReferenceType()); 6262 bool UseTemporary = Entity.getType()->isReferenceType(); 6263 bool IsStdInitListInit = 6264 Step->Kind == SK_StdInitializerListConstructorCall; 6265 CurInit = PerformConstructorInitialization( 6266 S, UseTemporary ? TempEntity : Entity, Kind, Args, *Step, 6267 ConstructorInitRequiresZeroInit, 6268 /*IsListInitialization*/IsStdInitListInit, 6269 /*IsStdInitListInitialization*/IsStdInitListInit, 6270 /*LBraceLoc*/SourceLocation(), 6271 /*RBraceLoc*/SourceLocation()); 6272 break; 6273 } 6274 6275 case SK_ZeroInitialization: { 6276 step_iterator NextStep = Step; 6277 ++NextStep; 6278 if (NextStep != StepEnd && 6279 (NextStep->Kind == SK_ConstructorInitialization || 6280 NextStep->Kind == SK_ConstructorInitializationFromList)) { 6281 // The need for zero-initialization is recorded directly into 6282 // the call to the object's constructor within the next step. 6283 ConstructorInitRequiresZeroInit = true; 6284 } else if (Kind.getKind() == InitializationKind::IK_Value && 6285 S.getLangOpts().CPlusPlus && 6286 !Kind.isImplicitValueInit()) { 6287 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo(); 6288 if (!TSInfo) 6289 TSInfo = S.Context.getTrivialTypeSourceInfo(Step->Type, 6290 Kind.getRange().getBegin()); 6291 6292 CurInit = new (S.Context) CXXScalarValueInitExpr( 6293 TSInfo->getType().getNonLValueExprType(S.Context), TSInfo, 6294 Kind.getRange().getEnd()); 6295 } else { 6296 CurInit = new (S.Context) ImplicitValueInitExpr(Step->Type); 6297 } 6298 break; 6299 } 6300 6301 case SK_CAssignment: { 6302 QualType SourceType = CurInit.get()->getType(); 6303 ExprResult Result = CurInit; 6304 Sema::AssignConvertType ConvTy = 6305 S.CheckSingleAssignmentConstraints(Step->Type, Result, true, 6306 Entity.getKind() == InitializedEntity::EK_Parameter_CF_Audited); 6307 if (Result.isInvalid()) 6308 return ExprError(); 6309 CurInit = Result; 6310 6311 // If this is a call, allow conversion to a transparent union. 6312 ExprResult CurInitExprRes = CurInit; 6313 if (ConvTy != Sema::Compatible && 6314 Entity.isParameterKind() && 6315 S.CheckTransparentUnionArgumentConstraints(Step->Type, CurInitExprRes) 6316 == Sema::Compatible) 6317 ConvTy = Sema::Compatible; 6318 if (CurInitExprRes.isInvalid()) 6319 return ExprError(); 6320 CurInit = CurInitExprRes; 6321 6322 bool Complained; 6323 if (S.DiagnoseAssignmentResult(ConvTy, Kind.getLocation(), 6324 Step->Type, SourceType, 6325 CurInit.get(), 6326 getAssignmentAction(Entity, true), 6327 &Complained)) { 6328 PrintInitLocationNote(S, Entity); 6329 return ExprError(); 6330 } else if (Complained) 6331 PrintInitLocationNote(S, Entity); 6332 break; 6333 } 6334 6335 case SK_StringInit: { 6336 QualType Ty = Step->Type; 6337 CheckStringInit(CurInit.get(), ResultType ? *ResultType : Ty, 6338 S.Context.getAsArrayType(Ty), S); 6339 break; 6340 } 6341 6342 case SK_ObjCObjectConversion: 6343 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type, 6344 CK_ObjCObjectLValueCast, 6345 CurInit.get()->getValueKind()); 6346 break; 6347 6348 case SK_ArrayInit: 6349 // Okay: we checked everything before creating this step. Note that 6350 // this is a GNU extension. 6351 S.Diag(Kind.getLocation(), diag::ext_array_init_copy) 6352 << Step->Type << CurInit.get()->getType() 6353 << CurInit.get()->getSourceRange(); 6354 6355 // If the destination type is an incomplete array type, update the 6356 // type accordingly. 6357 if (ResultType) { 6358 if (const IncompleteArrayType *IncompleteDest 6359 = S.Context.getAsIncompleteArrayType(Step->Type)) { 6360 if (const ConstantArrayType *ConstantSource 6361 = S.Context.getAsConstantArrayType(CurInit.get()->getType())) { 6362 *ResultType = S.Context.getConstantArrayType( 6363 IncompleteDest->getElementType(), 6364 ConstantSource->getSize(), 6365 ArrayType::Normal, 0); 6366 } 6367 } 6368 } 6369 break; 6370 6371 case SK_ParenthesizedArrayInit: 6372 // Okay: we checked everything before creating this step. Note that 6373 // this is a GNU extension. 6374 S.Diag(Kind.getLocation(), diag::ext_array_init_parens) 6375 << CurInit.get()->getSourceRange(); 6376 break; 6377 6378 case SK_PassByIndirectCopyRestore: 6379 case SK_PassByIndirectRestore: 6380 checkIndirectCopyRestoreSource(S, CurInit.get()); 6381 CurInit = new (S.Context) ObjCIndirectCopyRestoreExpr( 6382 CurInit.get(), Step->Type, 6383 Step->Kind == SK_PassByIndirectCopyRestore); 6384 break; 6385 6386 case SK_ProduceObjCObject: 6387 CurInit = 6388 ImplicitCastExpr::Create(S.Context, Step->Type, CK_ARCProduceObject, 6389 CurInit.get(), nullptr, VK_RValue); 6390 break; 6391 6392 case SK_StdInitializerList: { 6393 S.Diag(CurInit.get()->getExprLoc(), 6394 diag::warn_cxx98_compat_initializer_list_init) 6395 << CurInit.get()->getSourceRange(); 6396 6397 // Materialize the temporary into memory. 6398 MaterializeTemporaryExpr *MTE = new (S.Context) 6399 MaterializeTemporaryExpr(CurInit.get()->getType(), CurInit.get(), 6400 /*BoundToLvalueReference=*/false); 6401 6402 // Maybe lifetime-extend the array temporary's subobjects to match the 6403 // entity's lifetime. 6404 if (const InitializedEntity *ExtendingEntity = 6405 getEntityForTemporaryLifetimeExtension(&Entity)) 6406 if (performReferenceExtension(MTE, ExtendingEntity)) 6407 warnOnLifetimeExtension(S, Entity, CurInit.get(), 6408 /*IsInitializerList=*/true, 6409 ExtendingEntity->getDecl()); 6410 6411 // Wrap it in a construction of a std::initializer_list<T>. 6412 CurInit = new (S.Context) CXXStdInitializerListExpr(Step->Type, MTE); 6413 6414 // Bind the result, in case the library has given initializer_list a 6415 // non-trivial destructor. 6416 if (shouldBindAsTemporary(Entity)) 6417 CurInit = S.MaybeBindToTemporary(CurInit.get()); 6418 break; 6419 } 6420 6421 case SK_OCLSamplerInit: { 6422 assert(Step->Type->isSamplerT() && 6423 "Sampler initialization on non-sampler type."); 6424 6425 QualType SourceType = CurInit.get()->getType(); 6426 6427 if (Entity.isParameterKind()) { 6428 if (!SourceType->isSamplerT()) 6429 S.Diag(Kind.getLocation(), diag::err_sampler_argument_required) 6430 << SourceType; 6431 } else if (Entity.getKind() != InitializedEntity::EK_Variable) { 6432 llvm_unreachable("Invalid EntityKind!"); 6433 } 6434 6435 break; 6436 } 6437 case SK_OCLZeroEvent: { 6438 assert(Step->Type->isEventT() && 6439 "Event initialization on non-event type."); 6440 6441 CurInit = S.ImpCastExprToType(CurInit.get(), Step->Type, 6442 CK_ZeroToOCLEvent, 6443 CurInit.get()->getValueKind()); 6444 break; 6445 } 6446 } 6447 } 6448 6449 // Diagnose non-fatal problems with the completed initialization. 6450 if (Entity.getKind() == InitializedEntity::EK_Member && 6451 cast<FieldDecl>(Entity.getDecl())->isBitField()) 6452 S.CheckBitFieldInitialization(Kind.getLocation(), 6453 cast<FieldDecl>(Entity.getDecl()), 6454 CurInit.get()); 6455 6456 return CurInit; 6457 } 6458 6459 /// Somewhere within T there is an uninitialized reference subobject. 6460 /// Dig it out and diagnose it. 6461 static bool DiagnoseUninitializedReference(Sema &S, SourceLocation Loc, 6462 QualType T) { 6463 if (T->isReferenceType()) { 6464 S.Diag(Loc, diag::err_reference_without_init) 6465 << T.getNonReferenceType(); 6466 return true; 6467 } 6468 6469 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 6470 if (!RD || !RD->hasUninitializedReferenceMember()) 6471 return false; 6472 6473 for (const auto *FI : RD->fields()) { 6474 if (FI->isUnnamedBitfield()) 6475 continue; 6476 6477 if (DiagnoseUninitializedReference(S, FI->getLocation(), FI->getType())) { 6478 S.Diag(Loc, diag::note_value_initialization_here) << RD; 6479 return true; 6480 } 6481 } 6482 6483 for (const auto &BI : RD->bases()) { 6484 if (DiagnoseUninitializedReference(S, BI.getLocStart(), BI.getType())) { 6485 S.Diag(Loc, diag::note_value_initialization_here) << RD; 6486 return true; 6487 } 6488 } 6489 6490 return false; 6491 } 6492 6493 6494 //===----------------------------------------------------------------------===// 6495 // Diagnose initialization failures 6496 //===----------------------------------------------------------------------===// 6497 6498 /// Emit notes associated with an initialization that failed due to a 6499 /// "simple" conversion failure. 6500 static void emitBadConversionNotes(Sema &S, const InitializedEntity &entity, 6501 Expr *op) { 6502 QualType destType = entity.getType(); 6503 if (destType.getNonReferenceType()->isObjCObjectPointerType() && 6504 op->getType()->isObjCObjectPointerType()) { 6505 6506 // Emit a possible note about the conversion failing because the 6507 // operand is a message send with a related result type. 6508 S.EmitRelatedResultTypeNote(op); 6509 6510 // Emit a possible note about a return failing because we're 6511 // expecting a related result type. 6512 if (entity.getKind() == InitializedEntity::EK_Result) 6513 S.EmitRelatedResultTypeNoteForReturn(destType); 6514 } 6515 } 6516 6517 static void diagnoseListInit(Sema &S, const InitializedEntity &Entity, 6518 InitListExpr *InitList) { 6519 QualType DestType = Entity.getType(); 6520 6521 QualType E; 6522 if (S.getLangOpts().CPlusPlus11 && S.isStdInitializerList(DestType, &E)) { 6523 QualType ArrayType = S.Context.getConstantArrayType( 6524 E.withConst(), 6525 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()), 6526 InitList->getNumInits()), 6527 clang::ArrayType::Normal, 0); 6528 InitializedEntity HiddenArray = 6529 InitializedEntity::InitializeTemporary(ArrayType); 6530 return diagnoseListInit(S, HiddenArray, InitList); 6531 } 6532 6533 if (DestType->isReferenceType()) { 6534 // A list-initialization failure for a reference means that we tried to 6535 // create a temporary of the inner type (per [dcl.init.list]p3.6) and the 6536 // inner initialization failed. 6537 QualType T = DestType->getAs<ReferenceType>()->getPointeeType(); 6538 diagnoseListInit(S, InitializedEntity::InitializeTemporary(T), InitList); 6539 SourceLocation Loc = InitList->getLocStart(); 6540 if (auto *D = Entity.getDecl()) 6541 Loc = D->getLocation(); 6542 S.Diag(Loc, diag::note_in_reference_temporary_list_initializer) << T; 6543 return; 6544 } 6545 6546 InitListChecker DiagnoseInitList(S, Entity, InitList, DestType, 6547 /*VerifyOnly=*/false); 6548 assert(DiagnoseInitList.HadError() && 6549 "Inconsistent init list check result."); 6550 } 6551 6552 /// Prints a fixit for adding a null initializer for |Entity|. Call this only 6553 /// right after emitting a diagnostic. 6554 static void maybeEmitZeroInitializationFixit(Sema &S, 6555 InitializationSequence &Sequence, 6556 const InitializedEntity &Entity) { 6557 if (Entity.getKind() != InitializedEntity::EK_Variable) 6558 return; 6559 6560 VarDecl *VD = cast<VarDecl>(Entity.getDecl()); 6561 if (VD->getInit() || VD->getLocEnd().isMacroID()) 6562 return; 6563 6564 QualType VariableTy = VD->getType().getCanonicalType(); 6565 SourceLocation Loc = S.getLocForEndOfToken(VD->getLocEnd()); 6566 std::string Init = S.getFixItZeroInitializerForType(VariableTy, Loc); 6567 6568 S.Diag(Loc, diag::note_add_initializer) 6569 << VD << FixItHint::CreateInsertion(Loc, Init); 6570 } 6571 6572 bool InitializationSequence::Diagnose(Sema &S, 6573 const InitializedEntity &Entity, 6574 const InitializationKind &Kind, 6575 ArrayRef<Expr *> Args) { 6576 if (!Failed()) 6577 return false; 6578 6579 QualType DestType = Entity.getType(); 6580 switch (Failure) { 6581 case FK_TooManyInitsForReference: 6582 // FIXME: Customize for the initialized entity? 6583 if (Args.empty()) { 6584 // Dig out the reference subobject which is uninitialized and diagnose it. 6585 // If this is value-initialization, this could be nested some way within 6586 // the target type. 6587 assert(Kind.getKind() == InitializationKind::IK_Value || 6588 DestType->isReferenceType()); 6589 bool Diagnosed = 6590 DiagnoseUninitializedReference(S, Kind.getLocation(), DestType); 6591 assert(Diagnosed && "couldn't find uninitialized reference to diagnose"); 6592 (void)Diagnosed; 6593 } else // FIXME: diagnostic below could be better! 6594 S.Diag(Kind.getLocation(), diag::err_reference_has_multiple_inits) 6595 << SourceRange(Args.front()->getLocStart(), Args.back()->getLocEnd()); 6596 break; 6597 6598 case FK_ArrayNeedsInitList: 6599 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 0; 6600 break; 6601 case FK_ArrayNeedsInitListOrStringLiteral: 6602 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 1; 6603 break; 6604 case FK_ArrayNeedsInitListOrWideStringLiteral: 6605 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 2; 6606 break; 6607 case FK_NarrowStringIntoWideCharArray: 6608 S.Diag(Kind.getLocation(), diag::err_array_init_narrow_string_into_wchar); 6609 break; 6610 case FK_WideStringIntoCharArray: 6611 S.Diag(Kind.getLocation(), diag::err_array_init_wide_string_into_char); 6612 break; 6613 case FK_IncompatWideStringIntoWideChar: 6614 S.Diag(Kind.getLocation(), 6615 diag::err_array_init_incompat_wide_string_into_wchar); 6616 break; 6617 case FK_ArrayTypeMismatch: 6618 case FK_NonConstantArrayInit: 6619 S.Diag(Kind.getLocation(), 6620 (Failure == FK_ArrayTypeMismatch 6621 ? diag::err_array_init_different_type 6622 : diag::err_array_init_non_constant_array)) 6623 << DestType.getNonReferenceType() 6624 << Args[0]->getType() 6625 << Args[0]->getSourceRange(); 6626 break; 6627 6628 case FK_VariableLengthArrayHasInitializer: 6629 S.Diag(Kind.getLocation(), diag::err_variable_object_no_init) 6630 << Args[0]->getSourceRange(); 6631 break; 6632 6633 case FK_AddressOfOverloadFailed: { 6634 DeclAccessPair Found; 6635 S.ResolveAddressOfOverloadedFunction(Args[0], 6636 DestType.getNonReferenceType(), 6637 true, 6638 Found); 6639 break; 6640 } 6641 6642 case FK_ReferenceInitOverloadFailed: 6643 case FK_UserConversionOverloadFailed: 6644 switch (FailedOverloadResult) { 6645 case OR_Ambiguous: 6646 if (Failure == FK_UserConversionOverloadFailed) 6647 S.Diag(Kind.getLocation(), diag::err_typecheck_ambiguous_condition) 6648 << Args[0]->getType() << DestType 6649 << Args[0]->getSourceRange(); 6650 else 6651 S.Diag(Kind.getLocation(), diag::err_ref_init_ambiguous) 6652 << DestType << Args[0]->getType() 6653 << Args[0]->getSourceRange(); 6654 6655 FailedCandidateSet.NoteCandidates(S, OCD_ViableCandidates, Args); 6656 break; 6657 6658 case OR_No_Viable_Function: 6659 if (!S.RequireCompleteType(Kind.getLocation(), 6660 DestType.getNonReferenceType(), 6661 diag::err_typecheck_nonviable_condition_incomplete, 6662 Args[0]->getType(), Args[0]->getSourceRange())) 6663 S.Diag(Kind.getLocation(), diag::err_typecheck_nonviable_condition) 6664 << Args[0]->getType() << Args[0]->getSourceRange() 6665 << DestType.getNonReferenceType(); 6666 6667 FailedCandidateSet.NoteCandidates(S, OCD_AllCandidates, Args); 6668 break; 6669 6670 case OR_Deleted: { 6671 S.Diag(Kind.getLocation(), diag::err_typecheck_deleted_function) 6672 << Args[0]->getType() << DestType.getNonReferenceType() 6673 << Args[0]->getSourceRange(); 6674 OverloadCandidateSet::iterator Best; 6675 OverloadingResult Ovl 6676 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best, 6677 true); 6678 if (Ovl == OR_Deleted) { 6679 S.NoteDeletedFunction(Best->Function); 6680 } else { 6681 llvm_unreachable("Inconsistent overload resolution?"); 6682 } 6683 break; 6684 } 6685 6686 case OR_Success: 6687 llvm_unreachable("Conversion did not fail!"); 6688 } 6689 break; 6690 6691 case FK_NonConstLValueReferenceBindingToTemporary: 6692 if (isa<InitListExpr>(Args[0])) { 6693 S.Diag(Kind.getLocation(), 6694 diag::err_lvalue_reference_bind_to_initlist) 6695 << DestType.getNonReferenceType().isVolatileQualified() 6696 << DestType.getNonReferenceType() 6697 << Args[0]->getSourceRange(); 6698 break; 6699 } 6700 // Intentional fallthrough 6701 6702 case FK_NonConstLValueReferenceBindingToUnrelated: 6703 S.Diag(Kind.getLocation(), 6704 Failure == FK_NonConstLValueReferenceBindingToTemporary 6705 ? diag::err_lvalue_reference_bind_to_temporary 6706 : diag::err_lvalue_reference_bind_to_unrelated) 6707 << DestType.getNonReferenceType().isVolatileQualified() 6708 << DestType.getNonReferenceType() 6709 << Args[0]->getType() 6710 << Args[0]->getSourceRange(); 6711 break; 6712 6713 case FK_RValueReferenceBindingToLValue: 6714 S.Diag(Kind.getLocation(), diag::err_lvalue_to_rvalue_ref) 6715 << DestType.getNonReferenceType() << Args[0]->getType() 6716 << Args[0]->getSourceRange(); 6717 break; 6718 6719 case FK_ReferenceInitDropsQualifiers: 6720 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals) 6721 << DestType.getNonReferenceType() 6722 << Args[0]->getType() 6723 << Args[0]->getSourceRange(); 6724 break; 6725 6726 case FK_ReferenceInitFailed: 6727 S.Diag(Kind.getLocation(), diag::err_reference_bind_failed) 6728 << DestType.getNonReferenceType() 6729 << Args[0]->isLValue() 6730 << Args[0]->getType() 6731 << Args[0]->getSourceRange(); 6732 emitBadConversionNotes(S, Entity, Args[0]); 6733 break; 6734 6735 case FK_ConversionFailed: { 6736 QualType FromType = Args[0]->getType(); 6737 PartialDiagnostic PDiag = S.PDiag(diag::err_init_conversion_failed) 6738 << (int)Entity.getKind() 6739 << DestType 6740 << Args[0]->isLValue() 6741 << FromType 6742 << Args[0]->getSourceRange(); 6743 S.HandleFunctionTypeMismatch(PDiag, FromType, DestType); 6744 S.Diag(Kind.getLocation(), PDiag); 6745 emitBadConversionNotes(S, Entity, Args[0]); 6746 break; 6747 } 6748 6749 case FK_ConversionFromPropertyFailed: 6750 // No-op. This error has already been reported. 6751 break; 6752 6753 case FK_TooManyInitsForScalar: { 6754 SourceRange R; 6755 6756 auto *InitList = dyn_cast<InitListExpr>(Args[0]); 6757 if (InitList && InitList->getNumInits() == 1) 6758 R = SourceRange(InitList->getInit(0)->getLocEnd(), InitList->getLocEnd()); 6759 else 6760 R = SourceRange(Args.front()->getLocEnd(), Args.back()->getLocEnd()); 6761 6762 R.setBegin(S.getLocForEndOfToken(R.getBegin())); 6763 if (Kind.isCStyleOrFunctionalCast()) 6764 S.Diag(Kind.getLocation(), diag::err_builtin_func_cast_more_than_one_arg) 6765 << R; 6766 else 6767 S.Diag(Kind.getLocation(), diag::err_excess_initializers) 6768 << /*scalar=*/2 << R; 6769 break; 6770 } 6771 6772 case FK_ReferenceBindingToInitList: 6773 S.Diag(Kind.getLocation(), diag::err_reference_bind_init_list) 6774 << DestType.getNonReferenceType() << Args[0]->getSourceRange(); 6775 break; 6776 6777 case FK_InitListBadDestinationType: 6778 S.Diag(Kind.getLocation(), diag::err_init_list_bad_dest_type) 6779 << (DestType->isRecordType()) << DestType << Args[0]->getSourceRange(); 6780 break; 6781 6782 case FK_ListConstructorOverloadFailed: 6783 case FK_ConstructorOverloadFailed: { 6784 SourceRange ArgsRange; 6785 if (Args.size()) 6786 ArgsRange = SourceRange(Args.front()->getLocStart(), 6787 Args.back()->getLocEnd()); 6788 6789 if (Failure == FK_ListConstructorOverloadFailed) { 6790 assert(Args.size() == 1 && 6791 "List construction from other than 1 argument."); 6792 InitListExpr *InitList = cast<InitListExpr>(Args[0]); 6793 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits()); 6794 } 6795 6796 // FIXME: Using "DestType" for the entity we're printing is probably 6797 // bad. 6798 switch (FailedOverloadResult) { 6799 case OR_Ambiguous: 6800 S.Diag(Kind.getLocation(), diag::err_ovl_ambiguous_init) 6801 << DestType << ArgsRange; 6802 FailedCandidateSet.NoteCandidates(S, OCD_ViableCandidates, Args); 6803 break; 6804 6805 case OR_No_Viable_Function: 6806 if (Kind.getKind() == InitializationKind::IK_Default && 6807 (Entity.getKind() == InitializedEntity::EK_Base || 6808 Entity.getKind() == InitializedEntity::EK_Member) && 6809 isa<CXXConstructorDecl>(S.CurContext)) { 6810 // This is implicit default initialization of a member or 6811 // base within a constructor. If no viable function was 6812 // found, notify the user that she needs to explicitly 6813 // initialize this base/member. 6814 CXXConstructorDecl *Constructor 6815 = cast<CXXConstructorDecl>(S.CurContext); 6816 if (Entity.getKind() == InitializedEntity::EK_Base) { 6817 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor) 6818 << (Constructor->getInheritedConstructor() ? 2 : 6819 Constructor->isImplicit() ? 1 : 0) 6820 << S.Context.getTypeDeclType(Constructor->getParent()) 6821 << /*base=*/0 6822 << Entity.getType(); 6823 6824 RecordDecl *BaseDecl 6825 = Entity.getBaseSpecifier()->getType()->getAs<RecordType>() 6826 ->getDecl(); 6827 S.Diag(BaseDecl->getLocation(), diag::note_previous_decl) 6828 << S.Context.getTagDeclType(BaseDecl); 6829 } else { 6830 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor) 6831 << (Constructor->getInheritedConstructor() ? 2 : 6832 Constructor->isImplicit() ? 1 : 0) 6833 << S.Context.getTypeDeclType(Constructor->getParent()) 6834 << /*member=*/1 6835 << Entity.getName(); 6836 S.Diag(Entity.getDecl()->getLocation(), 6837 diag::note_member_declared_at); 6838 6839 if (const RecordType *Record 6840 = Entity.getType()->getAs<RecordType>()) 6841 S.Diag(Record->getDecl()->getLocation(), 6842 diag::note_previous_decl) 6843 << S.Context.getTagDeclType(Record->getDecl()); 6844 } 6845 break; 6846 } 6847 6848 S.Diag(Kind.getLocation(), diag::err_ovl_no_viable_function_in_init) 6849 << DestType << ArgsRange; 6850 FailedCandidateSet.NoteCandidates(S, OCD_AllCandidates, Args); 6851 break; 6852 6853 case OR_Deleted: { 6854 OverloadCandidateSet::iterator Best; 6855 OverloadingResult Ovl 6856 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best); 6857 if (Ovl != OR_Deleted) { 6858 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init) 6859 << true << DestType << ArgsRange; 6860 llvm_unreachable("Inconsistent overload resolution?"); 6861 break; 6862 } 6863 6864 // If this is a defaulted or implicitly-declared function, then 6865 // it was implicitly deleted. Make it clear that the deletion was 6866 // implicit. 6867 if (S.isImplicitlyDeleted(Best->Function)) 6868 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_special_init) 6869 << S.getSpecialMember(cast<CXXMethodDecl>(Best->Function)) 6870 << DestType << ArgsRange; 6871 else 6872 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init) 6873 << true << DestType << ArgsRange; 6874 6875 S.NoteDeletedFunction(Best->Function); 6876 break; 6877 } 6878 6879 case OR_Success: 6880 llvm_unreachable("Conversion did not fail!"); 6881 } 6882 } 6883 break; 6884 6885 case FK_DefaultInitOfConst: 6886 if (Entity.getKind() == InitializedEntity::EK_Member && 6887 isa<CXXConstructorDecl>(S.CurContext)) { 6888 // This is implicit default-initialization of a const member in 6889 // a constructor. Complain that it needs to be explicitly 6890 // initialized. 6891 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(S.CurContext); 6892 S.Diag(Kind.getLocation(), diag::err_uninitialized_member_in_ctor) 6893 << (Constructor->getInheritedConstructor() ? 2 : 6894 Constructor->isImplicit() ? 1 : 0) 6895 << S.Context.getTypeDeclType(Constructor->getParent()) 6896 << /*const=*/1 6897 << Entity.getName(); 6898 S.Diag(Entity.getDecl()->getLocation(), diag::note_previous_decl) 6899 << Entity.getName(); 6900 } else { 6901 S.Diag(Kind.getLocation(), diag::err_default_init_const) 6902 << DestType << (bool)DestType->getAs<RecordType>(); 6903 maybeEmitZeroInitializationFixit(S, *this, Entity); 6904 } 6905 break; 6906 6907 case FK_Incomplete: 6908 S.RequireCompleteType(Kind.getLocation(), FailedIncompleteType, 6909 diag::err_init_incomplete_type); 6910 break; 6911 6912 case FK_ListInitializationFailed: { 6913 // Run the init list checker again to emit diagnostics. 6914 InitListExpr *InitList = cast<InitListExpr>(Args[0]); 6915 diagnoseListInit(S, Entity, InitList); 6916 break; 6917 } 6918 6919 case FK_PlaceholderType: { 6920 // FIXME: Already diagnosed! 6921 break; 6922 } 6923 6924 case FK_ExplicitConstructor: { 6925 S.Diag(Kind.getLocation(), diag::err_selected_explicit_constructor) 6926 << Args[0]->getSourceRange(); 6927 OverloadCandidateSet::iterator Best; 6928 OverloadingResult Ovl 6929 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best); 6930 (void)Ovl; 6931 assert(Ovl == OR_Success && "Inconsistent overload resolution"); 6932 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function); 6933 S.Diag(CtorDecl->getLocation(), diag::note_constructor_declared_here); 6934 break; 6935 } 6936 } 6937 6938 PrintInitLocationNote(S, Entity); 6939 return true; 6940 } 6941 6942 void InitializationSequence::dump(raw_ostream &OS) const { 6943 switch (SequenceKind) { 6944 case FailedSequence: { 6945 OS << "Failed sequence: "; 6946 switch (Failure) { 6947 case FK_TooManyInitsForReference: 6948 OS << "too many initializers for reference"; 6949 break; 6950 6951 case FK_ArrayNeedsInitList: 6952 OS << "array requires initializer list"; 6953 break; 6954 6955 case FK_ArrayNeedsInitListOrStringLiteral: 6956 OS << "array requires initializer list or string literal"; 6957 break; 6958 6959 case FK_ArrayNeedsInitListOrWideStringLiteral: 6960 OS << "array requires initializer list or wide string literal"; 6961 break; 6962 6963 case FK_NarrowStringIntoWideCharArray: 6964 OS << "narrow string into wide char array"; 6965 break; 6966 6967 case FK_WideStringIntoCharArray: 6968 OS << "wide string into char array"; 6969 break; 6970 6971 case FK_IncompatWideStringIntoWideChar: 6972 OS << "incompatible wide string into wide char array"; 6973 break; 6974 6975 case FK_ArrayTypeMismatch: 6976 OS << "array type mismatch"; 6977 break; 6978 6979 case FK_NonConstantArrayInit: 6980 OS << "non-constant array initializer"; 6981 break; 6982 6983 case FK_AddressOfOverloadFailed: 6984 OS << "address of overloaded function failed"; 6985 break; 6986 6987 case FK_ReferenceInitOverloadFailed: 6988 OS << "overload resolution for reference initialization failed"; 6989 break; 6990 6991 case FK_NonConstLValueReferenceBindingToTemporary: 6992 OS << "non-const lvalue reference bound to temporary"; 6993 break; 6994 6995 case FK_NonConstLValueReferenceBindingToUnrelated: 6996 OS << "non-const lvalue reference bound to unrelated type"; 6997 break; 6998 6999 case FK_RValueReferenceBindingToLValue: 7000 OS << "rvalue reference bound to an lvalue"; 7001 break; 7002 7003 case FK_ReferenceInitDropsQualifiers: 7004 OS << "reference initialization drops qualifiers"; 7005 break; 7006 7007 case FK_ReferenceInitFailed: 7008 OS << "reference initialization failed"; 7009 break; 7010 7011 case FK_ConversionFailed: 7012 OS << "conversion failed"; 7013 break; 7014 7015 case FK_ConversionFromPropertyFailed: 7016 OS << "conversion from property failed"; 7017 break; 7018 7019 case FK_TooManyInitsForScalar: 7020 OS << "too many initializers for scalar"; 7021 break; 7022 7023 case FK_ReferenceBindingToInitList: 7024 OS << "referencing binding to initializer list"; 7025 break; 7026 7027 case FK_InitListBadDestinationType: 7028 OS << "initializer list for non-aggregate, non-scalar type"; 7029 break; 7030 7031 case FK_UserConversionOverloadFailed: 7032 OS << "overloading failed for user-defined conversion"; 7033 break; 7034 7035 case FK_ConstructorOverloadFailed: 7036 OS << "constructor overloading failed"; 7037 break; 7038 7039 case FK_DefaultInitOfConst: 7040 OS << "default initialization of a const variable"; 7041 break; 7042 7043 case FK_Incomplete: 7044 OS << "initialization of incomplete type"; 7045 break; 7046 7047 case FK_ListInitializationFailed: 7048 OS << "list initialization checker failure"; 7049 break; 7050 7051 case FK_VariableLengthArrayHasInitializer: 7052 OS << "variable length array has an initializer"; 7053 break; 7054 7055 case FK_PlaceholderType: 7056 OS << "initializer expression isn't contextually valid"; 7057 break; 7058 7059 case FK_ListConstructorOverloadFailed: 7060 OS << "list constructor overloading failed"; 7061 break; 7062 7063 case FK_ExplicitConstructor: 7064 OS << "list copy initialization chose explicit constructor"; 7065 break; 7066 } 7067 OS << '\n'; 7068 return; 7069 } 7070 7071 case DependentSequence: 7072 OS << "Dependent sequence\n"; 7073 return; 7074 7075 case NormalSequence: 7076 OS << "Normal sequence: "; 7077 break; 7078 } 7079 7080 for (step_iterator S = step_begin(), SEnd = step_end(); S != SEnd; ++S) { 7081 if (S != step_begin()) { 7082 OS << " -> "; 7083 } 7084 7085 switch (S->Kind) { 7086 case SK_ResolveAddressOfOverloadedFunction: 7087 OS << "resolve address of overloaded function"; 7088 break; 7089 7090 case SK_CastDerivedToBaseRValue: 7091 OS << "derived-to-base case (rvalue" << S->Type.getAsString() << ")"; 7092 break; 7093 7094 case SK_CastDerivedToBaseXValue: 7095 OS << "derived-to-base case (xvalue" << S->Type.getAsString() << ")"; 7096 break; 7097 7098 case SK_CastDerivedToBaseLValue: 7099 OS << "derived-to-base case (lvalue" << S->Type.getAsString() << ")"; 7100 break; 7101 7102 case SK_BindReference: 7103 OS << "bind reference to lvalue"; 7104 break; 7105 7106 case SK_BindReferenceToTemporary: 7107 OS << "bind reference to a temporary"; 7108 break; 7109 7110 case SK_ExtraneousCopyToTemporary: 7111 OS << "extraneous C++03 copy to temporary"; 7112 break; 7113 7114 case SK_UserConversion: 7115 OS << "user-defined conversion via " << *S->Function.Function; 7116 break; 7117 7118 case SK_QualificationConversionRValue: 7119 OS << "qualification conversion (rvalue)"; 7120 break; 7121 7122 case SK_QualificationConversionXValue: 7123 OS << "qualification conversion (xvalue)"; 7124 break; 7125 7126 case SK_QualificationConversionLValue: 7127 OS << "qualification conversion (lvalue)"; 7128 break; 7129 7130 case SK_AtomicConversion: 7131 OS << "non-atomic-to-atomic conversion"; 7132 break; 7133 7134 case SK_LValueToRValue: 7135 OS << "load (lvalue to rvalue)"; 7136 break; 7137 7138 case SK_ConversionSequence: 7139 OS << "implicit conversion sequence ("; 7140 S->ICS->dump(); // FIXME: use OS 7141 OS << ")"; 7142 break; 7143 7144 case SK_ConversionSequenceNoNarrowing: 7145 OS << "implicit conversion sequence with narrowing prohibited ("; 7146 S->ICS->dump(); // FIXME: use OS 7147 OS << ")"; 7148 break; 7149 7150 case SK_ListInitialization: 7151 OS << "list aggregate initialization"; 7152 break; 7153 7154 case SK_UnwrapInitList: 7155 OS << "unwrap reference initializer list"; 7156 break; 7157 7158 case SK_RewrapInitList: 7159 OS << "rewrap reference initializer list"; 7160 break; 7161 7162 case SK_ConstructorInitialization: 7163 OS << "constructor initialization"; 7164 break; 7165 7166 case SK_ConstructorInitializationFromList: 7167 OS << "list initialization via constructor"; 7168 break; 7169 7170 case SK_ZeroInitialization: 7171 OS << "zero initialization"; 7172 break; 7173 7174 case SK_CAssignment: 7175 OS << "C assignment"; 7176 break; 7177 7178 case SK_StringInit: 7179 OS << "string initialization"; 7180 break; 7181 7182 case SK_ObjCObjectConversion: 7183 OS << "Objective-C object conversion"; 7184 break; 7185 7186 case SK_ArrayInit: 7187 OS << "array initialization"; 7188 break; 7189 7190 case SK_ParenthesizedArrayInit: 7191 OS << "parenthesized array initialization"; 7192 break; 7193 7194 case SK_PassByIndirectCopyRestore: 7195 OS << "pass by indirect copy and restore"; 7196 break; 7197 7198 case SK_PassByIndirectRestore: 7199 OS << "pass by indirect restore"; 7200 break; 7201 7202 case SK_ProduceObjCObject: 7203 OS << "Objective-C object retension"; 7204 break; 7205 7206 case SK_StdInitializerList: 7207 OS << "std::initializer_list from initializer list"; 7208 break; 7209 7210 case SK_StdInitializerListConstructorCall: 7211 OS << "list initialization from std::initializer_list"; 7212 break; 7213 7214 case SK_OCLSamplerInit: 7215 OS << "OpenCL sampler_t from integer constant"; 7216 break; 7217 7218 case SK_OCLZeroEvent: 7219 OS << "OpenCL event_t from zero"; 7220 break; 7221 } 7222 7223 OS << " [" << S->Type.getAsString() << ']'; 7224 } 7225 7226 OS << '\n'; 7227 } 7228 7229 void InitializationSequence::dump() const { 7230 dump(llvm::errs()); 7231 } 7232 7233 static void DiagnoseNarrowingInInitList(Sema &S, 7234 const ImplicitConversionSequence &ICS, 7235 QualType PreNarrowingType, 7236 QualType EntityType, 7237 const Expr *PostInit) { 7238 const StandardConversionSequence *SCS = nullptr; 7239 switch (ICS.getKind()) { 7240 case ImplicitConversionSequence::StandardConversion: 7241 SCS = &ICS.Standard; 7242 break; 7243 case ImplicitConversionSequence::UserDefinedConversion: 7244 SCS = &ICS.UserDefined.After; 7245 break; 7246 case ImplicitConversionSequence::AmbiguousConversion: 7247 case ImplicitConversionSequence::EllipsisConversion: 7248 case ImplicitConversionSequence::BadConversion: 7249 return; 7250 } 7251 7252 // C++11 [dcl.init.list]p7: Check whether this is a narrowing conversion. 7253 APValue ConstantValue; 7254 QualType ConstantType; 7255 switch (SCS->getNarrowingKind(S.Context, PostInit, ConstantValue, 7256 ConstantType)) { 7257 case NK_Not_Narrowing: 7258 // No narrowing occurred. 7259 return; 7260 7261 case NK_Type_Narrowing: 7262 // This was a floating-to-integer conversion, which is always considered a 7263 // narrowing conversion even if the value is a constant and can be 7264 // represented exactly as an integer. 7265 S.Diag(PostInit->getLocStart(), 7266 (S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11) 7267 ? diag::warn_init_list_type_narrowing 7268 : diag::ext_init_list_type_narrowing) 7269 << PostInit->getSourceRange() 7270 << PreNarrowingType.getLocalUnqualifiedType() 7271 << EntityType.getLocalUnqualifiedType(); 7272 break; 7273 7274 case NK_Constant_Narrowing: 7275 // A constant value was narrowed. 7276 S.Diag(PostInit->getLocStart(), 7277 (S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11) 7278 ? diag::warn_init_list_constant_narrowing 7279 : diag::ext_init_list_constant_narrowing) 7280 << PostInit->getSourceRange() 7281 << ConstantValue.getAsString(S.getASTContext(), ConstantType) 7282 << EntityType.getLocalUnqualifiedType(); 7283 break; 7284 7285 case NK_Variable_Narrowing: 7286 // A variable's value may have been narrowed. 7287 S.Diag(PostInit->getLocStart(), 7288 (S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11) 7289 ? diag::warn_init_list_variable_narrowing 7290 : diag::ext_init_list_variable_narrowing) 7291 << PostInit->getSourceRange() 7292 << PreNarrowingType.getLocalUnqualifiedType() 7293 << EntityType.getLocalUnqualifiedType(); 7294 break; 7295 } 7296 7297 SmallString<128> StaticCast; 7298 llvm::raw_svector_ostream OS(StaticCast); 7299 OS << "static_cast<"; 7300 if (const TypedefType *TT = EntityType->getAs<TypedefType>()) { 7301 // It's important to use the typedef's name if there is one so that the 7302 // fixit doesn't break code using types like int64_t. 7303 // 7304 // FIXME: This will break if the typedef requires qualification. But 7305 // getQualifiedNameAsString() includes non-machine-parsable components. 7306 OS << *TT->getDecl(); 7307 } else if (const BuiltinType *BT = EntityType->getAs<BuiltinType>()) 7308 OS << BT->getName(S.getLangOpts()); 7309 else { 7310 // Oops, we didn't find the actual type of the variable. Don't emit a fixit 7311 // with a broken cast. 7312 return; 7313 } 7314 OS << ">("; 7315 S.Diag(PostInit->getLocStart(), diag::note_init_list_narrowing_silence) 7316 << PostInit->getSourceRange() 7317 << FixItHint::CreateInsertion(PostInit->getLocStart(), OS.str()) 7318 << FixItHint::CreateInsertion( 7319 S.getLocForEndOfToken(PostInit->getLocEnd()), ")"); 7320 } 7321 7322 //===----------------------------------------------------------------------===// 7323 // Initialization helper functions 7324 //===----------------------------------------------------------------------===// 7325 bool 7326 Sema::CanPerformCopyInitialization(const InitializedEntity &Entity, 7327 ExprResult Init) { 7328 if (Init.isInvalid()) 7329 return false; 7330 7331 Expr *InitE = Init.get(); 7332 assert(InitE && "No initialization expression"); 7333 7334 InitializationKind Kind 7335 = InitializationKind::CreateCopy(InitE->getLocStart(), SourceLocation()); 7336 InitializationSequence Seq(*this, Entity, Kind, InitE); 7337 return !Seq.Failed(); 7338 } 7339 7340 ExprResult 7341 Sema::PerformCopyInitialization(const InitializedEntity &Entity, 7342 SourceLocation EqualLoc, 7343 ExprResult Init, 7344 bool TopLevelOfInitList, 7345 bool AllowExplicit) { 7346 if (Init.isInvalid()) 7347 return ExprError(); 7348 7349 Expr *InitE = Init.get(); 7350 assert(InitE && "No initialization expression?"); 7351 7352 if (EqualLoc.isInvalid()) 7353 EqualLoc = InitE->getLocStart(); 7354 7355 InitializationKind Kind = InitializationKind::CreateCopy(InitE->getLocStart(), 7356 EqualLoc, 7357 AllowExplicit); 7358 InitializationSequence Seq(*this, Entity, Kind, InitE, TopLevelOfInitList); 7359 7360 ExprResult Result = Seq.Perform(*this, Entity, Kind, InitE); 7361 7362 return Result; 7363 } 7364
