SemaInit.cpp revision 4e47ecb6b2e399d2a7cc3a91d1eab9e501c5580f
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/Lex/Preprocessor.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> 29using 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). 37static 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 47enum 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. 59static 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 == 0) 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 123static 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. 133static 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 149static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT, 150 Sema &S) { 151 // Get the length of the string as parsed. 152 uint64_t StrLength = 153 cast<ConstantArrayType>(Str->getType())->getSize().getZExtValue(); 154 155 156 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::warn_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. 234namespace { 235class 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 unsigned &Index, InitListExpr *StructuredList, 249 unsigned &StructuredIndex, 250 bool TopLevelObject = false); 251 void CheckListElementTypes(const InitializedEntity &Entity, 252 InitListExpr *IList, QualType &DeclType, 253 bool SubobjectIsDesignatorContext, 254 unsigned &Index, 255 InitListExpr *StructuredList, 256 unsigned &StructuredIndex, 257 bool TopLevelObject = false); 258 void CheckSubElementType(const InitializedEntity &Entity, 259 InitListExpr *IList, QualType ElemType, 260 unsigned &Index, 261 InitListExpr *StructuredList, 262 unsigned &StructuredIndex); 263 void CheckComplexType(const InitializedEntity &Entity, 264 InitListExpr *IList, QualType DeclType, 265 unsigned &Index, 266 InitListExpr *StructuredList, 267 unsigned &StructuredIndex); 268 void CheckScalarType(const InitializedEntity &Entity, 269 InitListExpr *IList, QualType DeclType, 270 unsigned &Index, 271 InitListExpr *StructuredList, 272 unsigned &StructuredIndex); 273 void CheckReferenceType(const InitializedEntity &Entity, 274 InitListExpr *IList, QualType DeclType, 275 unsigned &Index, 276 InitListExpr *StructuredList, 277 unsigned &StructuredIndex); 278 void CheckVectorType(const InitializedEntity &Entity, 279 InitListExpr *IList, QualType DeclType, unsigned &Index, 280 InitListExpr *StructuredList, 281 unsigned &StructuredIndex); 282 void CheckStructUnionTypes(const InitializedEntity &Entity, 283 InitListExpr *IList, QualType DeclType, 284 RecordDecl::field_iterator Field, 285 bool SubobjectIsDesignatorContext, unsigned &Index, 286 InitListExpr *StructuredList, 287 unsigned &StructuredIndex, 288 bool TopLevelObject = false); 289 void CheckArrayType(const InitializedEntity &Entity, 290 InitListExpr *IList, QualType &DeclType, 291 llvm::APSInt elementIndex, 292 bool SubobjectIsDesignatorContext, unsigned &Index, 293 InitListExpr *StructuredList, 294 unsigned &StructuredIndex); 295 bool CheckDesignatedInitializer(const InitializedEntity &Entity, 296 InitListExpr *IList, DesignatedInitExpr *DIE, 297 unsigned DesigIdx, 298 QualType &CurrentObjectType, 299 RecordDecl::field_iterator *NextField, 300 llvm::APSInt *NextElementIndex, 301 unsigned &Index, 302 InitListExpr *StructuredList, 303 unsigned &StructuredIndex, 304 bool FinishSubobjectInit, 305 bool TopLevelObject); 306 InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index, 307 QualType CurrentObjectType, 308 InitListExpr *StructuredList, 309 unsigned StructuredIndex, 310 SourceRange InitRange); 311 void UpdateStructuredListElement(InitListExpr *StructuredList, 312 unsigned &StructuredIndex, 313 Expr *expr); 314 int numArrayElements(QualType DeclType); 315 int numStructUnionElements(QualType DeclType); 316 317 void FillInValueInitForField(unsigned Init, FieldDecl *Field, 318 const InitializedEntity &ParentEntity, 319 InitListExpr *ILE, bool &RequiresSecondPass); 320 void FillInValueInitializations(const InitializedEntity &Entity, 321 InitListExpr *ILE, bool &RequiresSecondPass); 322 bool CheckFlexibleArrayInit(const InitializedEntity &Entity, 323 Expr *InitExpr, FieldDecl *Field, 324 bool TopLevelObject); 325 void CheckValueInitializable(const InitializedEntity &Entity); 326 327public: 328 InitListChecker(Sema &S, const InitializedEntity &Entity, 329 InitListExpr *IL, QualType &T, bool VerifyOnly); 330 bool HadError() { return hadError; } 331 332 // @brief Retrieves the fully-structured initializer list used for 333 // semantic analysis and code generation. 334 InitListExpr *getFullyStructuredList() const { return FullyStructuredList; } 335}; 336} // end anonymous namespace 337 338void InitListChecker::CheckValueInitializable(const InitializedEntity &Entity) { 339 assert(VerifyOnly && 340 "CheckValueInitializable is only inteded for verification mode."); 341 342 SourceLocation Loc; 343 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, 344 true); 345 InitializationSequence InitSeq(SemaRef, Entity, Kind, None); 346 if (InitSeq.Failed()) 347 hadError = true; 348} 349 350void InitListChecker::FillInValueInitForField(unsigned Init, FieldDecl *Field, 351 const InitializedEntity &ParentEntity, 352 InitListExpr *ILE, 353 bool &RequiresSecondPass) { 354 SourceLocation Loc = ILE->getLocStart(); 355 unsigned NumInits = ILE->getNumInits(); 356 InitializedEntity MemberEntity 357 = InitializedEntity::InitializeMember(Field, &ParentEntity); 358 if (Init >= NumInits || !ILE->getInit(Init)) { 359 // If there's no explicit initializer but we have a default initializer, use 360 // that. This only happens in C++1y, since classes with default 361 // initializers are not aggregates in C++11. 362 if (Field->hasInClassInitializer()) { 363 Expr *DIE = CXXDefaultInitExpr::Create(SemaRef.Context, 364 ILE->getRBraceLoc(), Field); 365 if (Init < NumInits) 366 ILE->setInit(Init, DIE); 367 else { 368 ILE->updateInit(SemaRef.Context, Init, DIE); 369 RequiresSecondPass = true; 370 } 371 return; 372 } 373 374 // FIXME: We probably don't need to handle references 375 // specially here, since value-initialization of references is 376 // handled in InitializationSequence. 377 if (Field->getType()->isReferenceType()) { 378 // C++ [dcl.init.aggr]p9: 379 // If an incomplete or empty initializer-list leaves a 380 // member of reference type uninitialized, the program is 381 // ill-formed. 382 SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized) 383 << Field->getType() 384 << ILE->getSyntacticForm()->getSourceRange(); 385 SemaRef.Diag(Field->getLocation(), 386 diag::note_uninit_reference_member); 387 hadError = true; 388 return; 389 } 390 391 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, 392 true); 393 InitializationSequence InitSeq(SemaRef, MemberEntity, Kind, None); 394 if (!InitSeq) { 395 InitSeq.Diagnose(SemaRef, MemberEntity, Kind, None); 396 hadError = true; 397 return; 398 } 399 400 ExprResult MemberInit 401 = InitSeq.Perform(SemaRef, MemberEntity, Kind, None); 402 if (MemberInit.isInvalid()) { 403 hadError = true; 404 return; 405 } 406 407 if (hadError) { 408 // Do nothing 409 } else if (Init < NumInits) { 410 ILE->setInit(Init, MemberInit.takeAs<Expr>()); 411 } else if (InitSeq.isConstructorInitialization()) { 412 // Value-initialization requires a constructor call, so 413 // extend the initializer list to include the constructor 414 // call and make a note that we'll need to take another pass 415 // through the initializer list. 416 ILE->updateInit(SemaRef.Context, Init, MemberInit.takeAs<Expr>()); 417 RequiresSecondPass = true; 418 } 419 } else if (InitListExpr *InnerILE 420 = dyn_cast<InitListExpr>(ILE->getInit(Init))) 421 FillInValueInitializations(MemberEntity, InnerILE, 422 RequiresSecondPass); 423} 424 425/// Recursively replaces NULL values within the given initializer list 426/// with expressions that perform value-initialization of the 427/// appropriate type. 428void 429InitListChecker::FillInValueInitializations(const InitializedEntity &Entity, 430 InitListExpr *ILE, 431 bool &RequiresSecondPass) { 432 assert((ILE->getType() != SemaRef.Context.VoidTy) && 433 "Should not have void type"); 434 SourceLocation Loc = ILE->getLocStart(); 435 if (ILE->getSyntacticForm()) 436 Loc = ILE->getSyntacticForm()->getLocStart(); 437 438 if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) { 439 const RecordDecl *RDecl = RType->getDecl(); 440 if (RDecl->isUnion() && ILE->getInitializedFieldInUnion()) 441 FillInValueInitForField(0, ILE->getInitializedFieldInUnion(), 442 Entity, ILE, RequiresSecondPass); 443 else if (RDecl->isUnion() && isa<CXXRecordDecl>(RDecl) && 444 cast<CXXRecordDecl>(RDecl)->hasInClassInitializer()) { 445 for (RecordDecl::field_iterator Field = RDecl->field_begin(), 446 FieldEnd = RDecl->field_end(); 447 Field != FieldEnd; ++Field) { 448 if (Field->hasInClassInitializer()) { 449 FillInValueInitForField(0, *Field, Entity, ILE, RequiresSecondPass); 450 break; 451 } 452 } 453 } else { 454 unsigned Init = 0; 455 for (RecordDecl::field_iterator Field = RDecl->field_begin(), 456 FieldEnd = RDecl->field_end(); 457 Field != FieldEnd; ++Field) { 458 if (Field->isUnnamedBitfield()) 459 continue; 460 461 if (hadError) 462 return; 463 464 FillInValueInitForField(Init, *Field, Entity, ILE, RequiresSecondPass); 465 if (hadError) 466 return; 467 468 ++Init; 469 470 // Only look at the first initialization of a union. 471 if (RDecl->isUnion()) 472 break; 473 } 474 } 475 476 return; 477 } 478 479 QualType ElementType; 480 481 InitializedEntity ElementEntity = Entity; 482 unsigned NumInits = ILE->getNumInits(); 483 unsigned NumElements = NumInits; 484 if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) { 485 ElementType = AType->getElementType(); 486 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) 487 NumElements = CAType->getSize().getZExtValue(); 488 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context, 489 0, Entity); 490 } else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) { 491 ElementType = VType->getElementType(); 492 NumElements = VType->getNumElements(); 493 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context, 494 0, Entity); 495 } else 496 ElementType = ILE->getType(); 497 498 499 for (unsigned Init = 0; Init != NumElements; ++Init) { 500 if (hadError) 501 return; 502 503 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement || 504 ElementEntity.getKind() == InitializedEntity::EK_VectorElement) 505 ElementEntity.setElementIndex(Init); 506 507 Expr *InitExpr = (Init < NumInits ? ILE->getInit(Init) : 0); 508 if (!InitExpr && !ILE->hasArrayFiller()) { 509 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, 510 true); 511 InitializationSequence InitSeq(SemaRef, ElementEntity, Kind, None); 512 if (!InitSeq) { 513 InitSeq.Diagnose(SemaRef, ElementEntity, Kind, None); 514 hadError = true; 515 return; 516 } 517 518 ExprResult ElementInit 519 = InitSeq.Perform(SemaRef, ElementEntity, Kind, None); 520 if (ElementInit.isInvalid()) { 521 hadError = true; 522 return; 523 } 524 525 if (hadError) { 526 // Do nothing 527 } else if (Init < NumInits) { 528 // For arrays, just set the expression used for value-initialization 529 // of the "holes" in the array. 530 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) 531 ILE->setArrayFiller(ElementInit.takeAs<Expr>()); 532 else 533 ILE->setInit(Init, ElementInit.takeAs<Expr>()); 534 } else { 535 // For arrays, just set the expression used for value-initialization 536 // of the rest of elements and exit. 537 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) { 538 ILE->setArrayFiller(ElementInit.takeAs<Expr>()); 539 return; 540 } 541 542 if (InitSeq.isConstructorInitialization()) { 543 // Value-initialization requires a constructor call, so 544 // extend the initializer list to include the constructor 545 // call and make a note that we'll need to take another pass 546 // through the initializer list. 547 ILE->updateInit(SemaRef.Context, Init, ElementInit.takeAs<Expr>()); 548 RequiresSecondPass = true; 549 } 550 } 551 } else if (InitListExpr *InnerILE 552 = dyn_cast_or_null<InitListExpr>(InitExpr)) 553 FillInValueInitializations(ElementEntity, InnerILE, RequiresSecondPass); 554 } 555} 556 557 558InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity, 559 InitListExpr *IL, QualType &T, 560 bool VerifyOnly) 561 : SemaRef(S), VerifyOnly(VerifyOnly) { 562 hadError = false; 563 564 unsigned newIndex = 0; 565 unsigned newStructuredIndex = 0; 566 FullyStructuredList 567 = getStructuredSubobjectInit(IL, newIndex, T, 0, 0, IL->getSourceRange()); 568 CheckExplicitInitList(Entity, IL, T, newIndex, 569 FullyStructuredList, newStructuredIndex, 570 /*TopLevelObject=*/true); 571 572 if (!hadError && !VerifyOnly) { 573 bool RequiresSecondPass = false; 574 FillInValueInitializations(Entity, FullyStructuredList, RequiresSecondPass); 575 if (RequiresSecondPass && !hadError) 576 FillInValueInitializations(Entity, FullyStructuredList, 577 RequiresSecondPass); 578 } 579} 580 581int InitListChecker::numArrayElements(QualType DeclType) { 582 // FIXME: use a proper constant 583 int maxElements = 0x7FFFFFFF; 584 if (const ConstantArrayType *CAT = 585 SemaRef.Context.getAsConstantArrayType(DeclType)) { 586 maxElements = static_cast<int>(CAT->getSize().getZExtValue()); 587 } 588 return maxElements; 589} 590 591int InitListChecker::numStructUnionElements(QualType DeclType) { 592 RecordDecl *structDecl = DeclType->getAs<RecordType>()->getDecl(); 593 int InitializableMembers = 0; 594 for (RecordDecl::field_iterator 595 Field = structDecl->field_begin(), 596 FieldEnd = structDecl->field_end(); 597 Field != FieldEnd; ++Field) { 598 if (!Field->isUnnamedBitfield()) 599 ++InitializableMembers; 600 } 601 if (structDecl->isUnion()) 602 return std::min(InitializableMembers, 1); 603 return InitializableMembers - structDecl->hasFlexibleArrayMember(); 604} 605 606void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity, 607 InitListExpr *ParentIList, 608 QualType T, unsigned &Index, 609 InitListExpr *StructuredList, 610 unsigned &StructuredIndex) { 611 int maxElements = 0; 612 613 if (T->isArrayType()) 614 maxElements = numArrayElements(T); 615 else if (T->isRecordType()) 616 maxElements = numStructUnionElements(T); 617 else if (T->isVectorType()) 618 maxElements = T->getAs<VectorType>()->getNumElements(); 619 else 620 llvm_unreachable("CheckImplicitInitList(): Illegal type"); 621 622 if (maxElements == 0) { 623 if (!VerifyOnly) 624 SemaRef.Diag(ParentIList->getInit(Index)->getLocStart(), 625 diag::err_implicit_empty_initializer); 626 ++Index; 627 hadError = true; 628 return; 629 } 630 631 // Build a structured initializer list corresponding to this subobject. 632 InitListExpr *StructuredSubobjectInitList 633 = getStructuredSubobjectInit(ParentIList, Index, T, StructuredList, 634 StructuredIndex, 635 SourceRange(ParentIList->getInit(Index)->getLocStart(), 636 ParentIList->getSourceRange().getEnd())); 637 unsigned StructuredSubobjectInitIndex = 0; 638 639 // Check the element types and build the structural subobject. 640 unsigned StartIndex = Index; 641 CheckListElementTypes(Entity, ParentIList, T, 642 /*SubobjectIsDesignatorContext=*/false, Index, 643 StructuredSubobjectInitList, 644 StructuredSubobjectInitIndex); 645 646 if (!VerifyOnly) { 647 StructuredSubobjectInitList->setType(T); 648 649 unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1); 650 // Update the structured sub-object initializer so that it's ending 651 // range corresponds with the end of the last initializer it used. 652 if (EndIndex < ParentIList->getNumInits()) { 653 SourceLocation EndLoc 654 = ParentIList->getInit(EndIndex)->getSourceRange().getEnd(); 655 StructuredSubobjectInitList->setRBraceLoc(EndLoc); 656 } 657 658 // Complain about missing braces. 659 if (T->isArrayType() || T->isRecordType()) { 660 SemaRef.Diag(StructuredSubobjectInitList->getLocStart(), 661 diag::warn_missing_braces) 662 << StructuredSubobjectInitList->getSourceRange() 663 << FixItHint::CreateInsertion( 664 StructuredSubobjectInitList->getLocStart(), "{") 665 << FixItHint::CreateInsertion( 666 SemaRef.PP.getLocForEndOfToken( 667 StructuredSubobjectInitList->getLocEnd()), 668 "}"); 669 } 670 } 671} 672 673void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity, 674 InitListExpr *IList, QualType &T, 675 unsigned &Index, 676 InitListExpr *StructuredList, 677 unsigned &StructuredIndex, 678 bool TopLevelObject) { 679 assert(IList->isExplicit() && "Illegal Implicit InitListExpr"); 680 if (!VerifyOnly) { 681 SyntacticToSemantic[IList] = StructuredList; 682 StructuredList->setSyntacticForm(IList); 683 } 684 CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true, 685 Index, StructuredList, StructuredIndex, TopLevelObject); 686 if (!VerifyOnly) { 687 QualType ExprTy = T; 688 if (!ExprTy->isArrayType()) 689 ExprTy = ExprTy.getNonLValueExprType(SemaRef.Context); 690 IList->setType(ExprTy); 691 StructuredList->setType(ExprTy); 692 } 693 if (hadError) 694 return; 695 696 if (Index < IList->getNumInits()) { 697 // We have leftover initializers 698 if (VerifyOnly) { 699 if (SemaRef.getLangOpts().CPlusPlus || 700 (SemaRef.getLangOpts().OpenCL && 701 IList->getType()->isVectorType())) { 702 hadError = true; 703 } 704 return; 705 } 706 707 if (StructuredIndex == 1 && 708 IsStringInit(StructuredList->getInit(0), T, SemaRef.Context) == 709 SIF_None) { 710 unsigned DK = diag::warn_excess_initializers_in_char_array_initializer; 711 if (SemaRef.getLangOpts().CPlusPlus) { 712 DK = diag::err_excess_initializers_in_char_array_initializer; 713 hadError = true; 714 } 715 // Special-case 716 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK) 717 << IList->getInit(Index)->getSourceRange(); 718 } else if (!T->isIncompleteType()) { 719 // Don't complain for incomplete types, since we'll get an error 720 // elsewhere 721 QualType CurrentObjectType = StructuredList->getType(); 722 int initKind = 723 CurrentObjectType->isArrayType()? 0 : 724 CurrentObjectType->isVectorType()? 1 : 725 CurrentObjectType->isScalarType()? 2 : 726 CurrentObjectType->isUnionType()? 3 : 727 4; 728 729 unsigned DK = diag::warn_excess_initializers; 730 if (SemaRef.getLangOpts().CPlusPlus) { 731 DK = diag::err_excess_initializers; 732 hadError = true; 733 } 734 if (SemaRef.getLangOpts().OpenCL && initKind == 1) { 735 DK = diag::err_excess_initializers; 736 hadError = true; 737 } 738 739 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK) 740 << initKind << IList->getInit(Index)->getSourceRange(); 741 } 742 } 743 744 if (!VerifyOnly && T->isScalarType() && IList->getNumInits() == 1 && 745 !TopLevelObject) 746 SemaRef.Diag(IList->getLocStart(), diag::warn_braces_around_scalar_init) 747 << IList->getSourceRange() 748 << FixItHint::CreateRemoval(IList->getLocStart()) 749 << FixItHint::CreateRemoval(IList->getLocEnd()); 750} 751 752void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity, 753 InitListExpr *IList, 754 QualType &DeclType, 755 bool SubobjectIsDesignatorContext, 756 unsigned &Index, 757 InitListExpr *StructuredList, 758 unsigned &StructuredIndex, 759 bool TopLevelObject) { 760 if (DeclType->isAnyComplexType() && SubobjectIsDesignatorContext) { 761 // Explicitly braced initializer for complex type can be real+imaginary 762 // parts. 763 CheckComplexType(Entity, IList, DeclType, Index, 764 StructuredList, StructuredIndex); 765 } else if (DeclType->isScalarType()) { 766 CheckScalarType(Entity, IList, DeclType, Index, 767 StructuredList, StructuredIndex); 768 } else if (DeclType->isVectorType()) { 769 CheckVectorType(Entity, IList, DeclType, Index, 770 StructuredList, StructuredIndex); 771 } else if (DeclType->isRecordType()) { 772 assert(DeclType->isAggregateType() && 773 "non-aggregate records should be handed in CheckSubElementType"); 774 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 775 CheckStructUnionTypes(Entity, IList, DeclType, RD->field_begin(), 776 SubobjectIsDesignatorContext, Index, 777 StructuredList, StructuredIndex, 778 TopLevelObject); 779 } else if (DeclType->isArrayType()) { 780 llvm::APSInt Zero( 781 SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()), 782 false); 783 CheckArrayType(Entity, IList, DeclType, Zero, 784 SubobjectIsDesignatorContext, Index, 785 StructuredList, StructuredIndex); 786 } else if (DeclType->isVoidType() || DeclType->isFunctionType()) { 787 // This type is invalid, issue a diagnostic. 788 ++Index; 789 if (!VerifyOnly) 790 SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type) 791 << DeclType; 792 hadError = true; 793 } else if (DeclType->isReferenceType()) { 794 CheckReferenceType(Entity, IList, DeclType, Index, 795 StructuredList, StructuredIndex); 796 } else if (DeclType->isObjCObjectType()) { 797 if (!VerifyOnly) 798 SemaRef.Diag(IList->getLocStart(), diag::err_init_objc_class) 799 << DeclType; 800 hadError = true; 801 } else { 802 if (!VerifyOnly) 803 SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type) 804 << DeclType; 805 hadError = true; 806 } 807} 808 809void InitListChecker::CheckSubElementType(const InitializedEntity &Entity, 810 InitListExpr *IList, 811 QualType ElemType, 812 unsigned &Index, 813 InitListExpr *StructuredList, 814 unsigned &StructuredIndex) { 815 Expr *expr = IList->getInit(Index); 816 817 if (ElemType->isReferenceType()) 818 return CheckReferenceType(Entity, IList, ElemType, Index, 819 StructuredList, StructuredIndex); 820 821 if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) { 822 if (!ElemType->isRecordType() || ElemType->isAggregateType()) { 823 unsigned newIndex = 0; 824 unsigned newStructuredIndex = 0; 825 InitListExpr *newStructuredList 826 = getStructuredSubobjectInit(IList, Index, ElemType, 827 StructuredList, StructuredIndex, 828 SubInitList->getSourceRange()); 829 CheckExplicitInitList(Entity, SubInitList, ElemType, newIndex, 830 newStructuredList, newStructuredIndex); 831 ++StructuredIndex; 832 ++Index; 833 return; 834 } 835 assert(SemaRef.getLangOpts().CPlusPlus && 836 "non-aggregate records are only possible in C++"); 837 // C++ initialization is handled later. 838 } 839 840 if (ElemType->isScalarType()) 841 return CheckScalarType(Entity, IList, ElemType, Index, 842 StructuredList, StructuredIndex); 843 844 if (const ArrayType *arrayType = SemaRef.Context.getAsArrayType(ElemType)) { 845 // arrayType can be incomplete if we're initializing a flexible 846 // array member. There's nothing we can do with the completed 847 // type here, though. 848 849 if (IsStringInit(expr, arrayType, SemaRef.Context) == SIF_None) { 850 if (!VerifyOnly) { 851 CheckStringInit(expr, ElemType, arrayType, SemaRef); 852 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 853 } 854 ++Index; 855 return; 856 } 857 858 // Fall through for subaggregate initialization. 859 860 } else if (SemaRef.getLangOpts().CPlusPlus) { 861 // C++ [dcl.init.aggr]p12: 862 // All implicit type conversions (clause 4) are considered when 863 // initializing the aggregate member with an initializer from 864 // an initializer-list. If the initializer can initialize a 865 // member, the member is initialized. [...] 866 867 // FIXME: Better EqualLoc? 868 InitializationKind Kind = 869 InitializationKind::CreateCopy(expr->getLocStart(), SourceLocation()); 870 InitializationSequence Seq(SemaRef, Entity, Kind, expr); 871 872 if (Seq) { 873 if (!VerifyOnly) { 874 ExprResult Result = 875 Seq.Perform(SemaRef, Entity, Kind, expr); 876 if (Result.isInvalid()) 877 hadError = true; 878 879 UpdateStructuredListElement(StructuredList, StructuredIndex, 880 Result.takeAs<Expr>()); 881 } 882 ++Index; 883 return; 884 } 885 886 // Fall through for subaggregate initialization 887 } else { 888 // C99 6.7.8p13: 889 // 890 // The initializer for a structure or union object that has 891 // automatic storage duration shall be either an initializer 892 // list as described below, or a single expression that has 893 // compatible structure or union type. In the latter case, the 894 // initial value of the object, including unnamed members, is 895 // that of the expression. 896 ExprResult ExprRes = SemaRef.Owned(expr); 897 if ((ElemType->isRecordType() || ElemType->isVectorType()) && 898 SemaRef.CheckSingleAssignmentConstraints(ElemType, ExprRes, 899 !VerifyOnly) 900 == Sema::Compatible) { 901 if (ExprRes.isInvalid()) 902 hadError = true; 903 else { 904 ExprRes = SemaRef.DefaultFunctionArrayLvalueConversion(ExprRes.take()); 905 if (ExprRes.isInvalid()) 906 hadError = true; 907 } 908 UpdateStructuredListElement(StructuredList, StructuredIndex, 909 ExprRes.takeAs<Expr>()); 910 ++Index; 911 return; 912 } 913 ExprRes.release(); 914 // Fall through for subaggregate initialization 915 } 916 917 // C++ [dcl.init.aggr]p12: 918 // 919 // [...] Otherwise, if the member is itself a non-empty 920 // subaggregate, brace elision is assumed and the initializer is 921 // considered for the initialization of the first member of 922 // the subaggregate. 923 if (!SemaRef.getLangOpts().OpenCL && 924 (ElemType->isAggregateType() || ElemType->isVectorType())) { 925 CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList, 926 StructuredIndex); 927 ++StructuredIndex; 928 } else { 929 if (!VerifyOnly) { 930 // We cannot initialize this element, so let 931 // PerformCopyInitialization produce the appropriate diagnostic. 932 SemaRef.PerformCopyInitialization(Entity, SourceLocation(), 933 SemaRef.Owned(expr), 934 /*TopLevelOfInitList=*/true); 935 } 936 hadError = true; 937 ++Index; 938 ++StructuredIndex; 939 } 940} 941 942void InitListChecker::CheckComplexType(const InitializedEntity &Entity, 943 InitListExpr *IList, QualType DeclType, 944 unsigned &Index, 945 InitListExpr *StructuredList, 946 unsigned &StructuredIndex) { 947 assert(Index == 0 && "Index in explicit init list must be zero"); 948 949 // As an extension, clang supports complex initializers, which initialize 950 // a complex number component-wise. When an explicit initializer list for 951 // a complex number contains two two initializers, this extension kicks in: 952 // it exepcts the initializer list to contain two elements convertible to 953 // the element type of the complex type. The first element initializes 954 // the real part, and the second element intitializes the imaginary part. 955 956 if (IList->getNumInits() != 2) 957 return CheckScalarType(Entity, IList, DeclType, Index, StructuredList, 958 StructuredIndex); 959 960 // This is an extension in C. (The builtin _Complex type does not exist 961 // in the C++ standard.) 962 if (!SemaRef.getLangOpts().CPlusPlus && !VerifyOnly) 963 SemaRef.Diag(IList->getLocStart(), diag::ext_complex_component_init) 964 << IList->getSourceRange(); 965 966 // Initialize the complex number. 967 QualType elementType = DeclType->getAs<ComplexType>()->getElementType(); 968 InitializedEntity ElementEntity = 969 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 970 971 for (unsigned i = 0; i < 2; ++i) { 972 ElementEntity.setElementIndex(Index); 973 CheckSubElementType(ElementEntity, IList, elementType, Index, 974 StructuredList, StructuredIndex); 975 } 976} 977 978 979void InitListChecker::CheckScalarType(const InitializedEntity &Entity, 980 InitListExpr *IList, QualType DeclType, 981 unsigned &Index, 982 InitListExpr *StructuredList, 983 unsigned &StructuredIndex) { 984 if (Index >= IList->getNumInits()) { 985 if (!VerifyOnly) 986 SemaRef.Diag(IList->getLocStart(), 987 SemaRef.getLangOpts().CPlusPlus11 ? 988 diag::warn_cxx98_compat_empty_scalar_initializer : 989 diag::err_empty_scalar_initializer) 990 << IList->getSourceRange(); 991 hadError = !SemaRef.getLangOpts().CPlusPlus11; 992 ++Index; 993 ++StructuredIndex; 994 return; 995 } 996 997 Expr *expr = IList->getInit(Index); 998 if (InitListExpr *SubIList = dyn_cast<InitListExpr>(expr)) { 999 if (!VerifyOnly) 1000 SemaRef.Diag(SubIList->getLocStart(), 1001 diag::warn_many_braces_around_scalar_init) 1002 << SubIList->getSourceRange(); 1003 1004 CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList, 1005 StructuredIndex); 1006 return; 1007 } else if (isa<DesignatedInitExpr>(expr)) { 1008 if (!VerifyOnly) 1009 SemaRef.Diag(expr->getLocStart(), 1010 diag::err_designator_for_scalar_init) 1011 << DeclType << expr->getSourceRange(); 1012 hadError = true; 1013 ++Index; 1014 ++StructuredIndex; 1015 return; 1016 } 1017 1018 if (VerifyOnly) { 1019 if (!SemaRef.CanPerformCopyInitialization(Entity, SemaRef.Owned(expr))) 1020 hadError = true; 1021 ++Index; 1022 return; 1023 } 1024 1025 ExprResult Result = 1026 SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), 1027 SemaRef.Owned(expr), 1028 /*TopLevelOfInitList=*/true); 1029 1030 Expr *ResultExpr = 0; 1031 1032 if (Result.isInvalid()) 1033 hadError = true; // types weren't compatible. 1034 else { 1035 ResultExpr = Result.takeAs<Expr>(); 1036 1037 if (ResultExpr != expr) { 1038 // The type was promoted, update initializer list. 1039 IList->setInit(Index, ResultExpr); 1040 } 1041 } 1042 if (hadError) 1043 ++StructuredIndex; 1044 else 1045 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr); 1046 ++Index; 1047} 1048 1049void InitListChecker::CheckReferenceType(const InitializedEntity &Entity, 1050 InitListExpr *IList, QualType DeclType, 1051 unsigned &Index, 1052 InitListExpr *StructuredList, 1053 unsigned &StructuredIndex) { 1054 if (Index >= IList->getNumInits()) { 1055 // FIXME: It would be wonderful if we could point at the actual member. In 1056 // general, it would be useful to pass location information down the stack, 1057 // so that we know the location (or decl) of the "current object" being 1058 // initialized. 1059 if (!VerifyOnly) 1060 SemaRef.Diag(IList->getLocStart(), 1061 diag::err_init_reference_member_uninitialized) 1062 << DeclType 1063 << IList->getSourceRange(); 1064 hadError = true; 1065 ++Index; 1066 ++StructuredIndex; 1067 return; 1068 } 1069 1070 Expr *expr = IList->getInit(Index); 1071 if (isa<InitListExpr>(expr) && !SemaRef.getLangOpts().CPlusPlus11) { 1072 if (!VerifyOnly) 1073 SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list) 1074 << DeclType << IList->getSourceRange(); 1075 hadError = true; 1076 ++Index; 1077 ++StructuredIndex; 1078 return; 1079 } 1080 1081 if (VerifyOnly) { 1082 if (!SemaRef.CanPerformCopyInitialization(Entity, SemaRef.Owned(expr))) 1083 hadError = true; 1084 ++Index; 1085 return; 1086 } 1087 1088 ExprResult Result = 1089 SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), 1090 SemaRef.Owned(expr), 1091 /*TopLevelOfInitList=*/true); 1092 1093 if (Result.isInvalid()) 1094 hadError = true; 1095 1096 expr = Result.takeAs<Expr>(); 1097 IList->setInit(Index, expr); 1098 1099 if (hadError) 1100 ++StructuredIndex; 1101 else 1102 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 1103 ++Index; 1104} 1105 1106void InitListChecker::CheckVectorType(const InitializedEntity &Entity, 1107 InitListExpr *IList, QualType DeclType, 1108 unsigned &Index, 1109 InitListExpr *StructuredList, 1110 unsigned &StructuredIndex) { 1111 const VectorType *VT = DeclType->getAs<VectorType>(); 1112 unsigned maxElements = VT->getNumElements(); 1113 unsigned numEltsInit = 0; 1114 QualType elementType = VT->getElementType(); 1115 1116 if (Index >= IList->getNumInits()) { 1117 // Make sure the element type can be value-initialized. 1118 if (VerifyOnly) 1119 CheckValueInitializable( 1120 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity)); 1121 return; 1122 } 1123 1124 if (!SemaRef.getLangOpts().OpenCL) { 1125 // If the initializing element is a vector, try to copy-initialize 1126 // instead of breaking it apart (which is doomed to failure anyway). 1127 Expr *Init = IList->getInit(Index); 1128 if (!isa<InitListExpr>(Init) && Init->getType()->isVectorType()) { 1129 if (VerifyOnly) { 1130 if (!SemaRef.CanPerformCopyInitialization(Entity, SemaRef.Owned(Init))) 1131 hadError = true; 1132 ++Index; 1133 return; 1134 } 1135 1136 ExprResult Result = 1137 SemaRef.PerformCopyInitialization(Entity, Init->getLocStart(), 1138 SemaRef.Owned(Init), 1139 /*TopLevelOfInitList=*/true); 1140 1141 Expr *ResultExpr = 0; 1142 if (Result.isInvalid()) 1143 hadError = true; // types weren't compatible. 1144 else { 1145 ResultExpr = Result.takeAs<Expr>(); 1146 1147 if (ResultExpr != Init) { 1148 // The type was promoted, update initializer list. 1149 IList->setInit(Index, ResultExpr); 1150 } 1151 } 1152 if (hadError) 1153 ++StructuredIndex; 1154 else 1155 UpdateStructuredListElement(StructuredList, StructuredIndex, 1156 ResultExpr); 1157 ++Index; 1158 return; 1159 } 1160 1161 InitializedEntity ElementEntity = 1162 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 1163 1164 for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) { 1165 // Don't attempt to go past the end of the init list 1166 if (Index >= IList->getNumInits()) { 1167 if (VerifyOnly) 1168 CheckValueInitializable(ElementEntity); 1169 break; 1170 } 1171 1172 ElementEntity.setElementIndex(Index); 1173 CheckSubElementType(ElementEntity, IList, elementType, Index, 1174 StructuredList, StructuredIndex); 1175 } 1176 return; 1177 } 1178 1179 InitializedEntity ElementEntity = 1180 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 1181 1182 // OpenCL initializers allows vectors to be constructed from vectors. 1183 for (unsigned i = 0; i < maxElements; ++i) { 1184 // Don't attempt to go past the end of the init list 1185 if (Index >= IList->getNumInits()) 1186 break; 1187 1188 ElementEntity.setElementIndex(Index); 1189 1190 QualType IType = IList->getInit(Index)->getType(); 1191 if (!IType->isVectorType()) { 1192 CheckSubElementType(ElementEntity, IList, elementType, Index, 1193 StructuredList, StructuredIndex); 1194 ++numEltsInit; 1195 } else { 1196 QualType VecType; 1197 const VectorType *IVT = IType->getAs<VectorType>(); 1198 unsigned numIElts = IVT->getNumElements(); 1199 1200 if (IType->isExtVectorType()) 1201 VecType = SemaRef.Context.getExtVectorType(elementType, numIElts); 1202 else 1203 VecType = SemaRef.Context.getVectorType(elementType, numIElts, 1204 IVT->getVectorKind()); 1205 CheckSubElementType(ElementEntity, IList, VecType, Index, 1206 StructuredList, StructuredIndex); 1207 numEltsInit += numIElts; 1208 } 1209 } 1210 1211 // OpenCL requires all elements to be initialized. 1212 if (numEltsInit != maxElements) { 1213 if (!VerifyOnly) 1214 SemaRef.Diag(IList->getLocStart(), 1215 diag::err_vector_incorrect_num_initializers) 1216 << (numEltsInit < maxElements) << maxElements << numEltsInit; 1217 hadError = true; 1218 } 1219} 1220 1221void InitListChecker::CheckArrayType(const InitializedEntity &Entity, 1222 InitListExpr *IList, QualType &DeclType, 1223 llvm::APSInt elementIndex, 1224 bool SubobjectIsDesignatorContext, 1225 unsigned &Index, 1226 InitListExpr *StructuredList, 1227 unsigned &StructuredIndex) { 1228 const ArrayType *arrayType = SemaRef.Context.getAsArrayType(DeclType); 1229 1230 // Check for the special-case of initializing an array with a string. 1231 if (Index < IList->getNumInits()) { 1232 if (IsStringInit(IList->getInit(Index), arrayType, SemaRef.Context) == 1233 SIF_None) { 1234 // We place the string literal directly into the resulting 1235 // initializer list. This is the only place where the structure 1236 // of the structured initializer list doesn't match exactly, 1237 // because doing so would involve allocating one character 1238 // constant for each string. 1239 if (!VerifyOnly) { 1240 CheckStringInit(IList->getInit(Index), DeclType, arrayType, SemaRef); 1241 UpdateStructuredListElement(StructuredList, StructuredIndex, 1242 IList->getInit(Index)); 1243 StructuredList->resizeInits(SemaRef.Context, StructuredIndex); 1244 } 1245 ++Index; 1246 return; 1247 } 1248 } 1249 if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(arrayType)) { 1250 // Check for VLAs; in standard C it would be possible to check this 1251 // earlier, but I don't know where clang accepts VLAs (gcc accepts 1252 // them in all sorts of strange places). 1253 if (!VerifyOnly) 1254 SemaRef.Diag(VAT->getSizeExpr()->getLocStart(), 1255 diag::err_variable_object_no_init) 1256 << VAT->getSizeExpr()->getSourceRange(); 1257 hadError = true; 1258 ++Index; 1259 ++StructuredIndex; 1260 return; 1261 } 1262 1263 // We might know the maximum number of elements in advance. 1264 llvm::APSInt maxElements(elementIndex.getBitWidth(), 1265 elementIndex.isUnsigned()); 1266 bool maxElementsKnown = false; 1267 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(arrayType)) { 1268 maxElements = CAT->getSize(); 1269 elementIndex = elementIndex.extOrTrunc(maxElements.getBitWidth()); 1270 elementIndex.setIsUnsigned(maxElements.isUnsigned()); 1271 maxElementsKnown = true; 1272 } 1273 1274 QualType elementType = arrayType->getElementType(); 1275 while (Index < IList->getNumInits()) { 1276 Expr *Init = IList->getInit(Index); 1277 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) { 1278 // If we're not the subobject that matches up with the '{' for 1279 // the designator, we shouldn't be handling the 1280 // designator. Return immediately. 1281 if (!SubobjectIsDesignatorContext) 1282 return; 1283 1284 // Handle this designated initializer. elementIndex will be 1285 // updated to be the next array element we'll initialize. 1286 if (CheckDesignatedInitializer(Entity, IList, DIE, 0, 1287 DeclType, 0, &elementIndex, Index, 1288 StructuredList, StructuredIndex, true, 1289 false)) { 1290 hadError = true; 1291 continue; 1292 } 1293 1294 if (elementIndex.getBitWidth() > maxElements.getBitWidth()) 1295 maxElements = maxElements.extend(elementIndex.getBitWidth()); 1296 else if (elementIndex.getBitWidth() < maxElements.getBitWidth()) 1297 elementIndex = elementIndex.extend(maxElements.getBitWidth()); 1298 elementIndex.setIsUnsigned(maxElements.isUnsigned()); 1299 1300 // If the array is of incomplete type, keep track of the number of 1301 // elements in the initializer. 1302 if (!maxElementsKnown && elementIndex > maxElements) 1303 maxElements = elementIndex; 1304 1305 continue; 1306 } 1307 1308 // If we know the maximum number of elements, and we've already 1309 // hit it, stop consuming elements in the initializer list. 1310 if (maxElementsKnown && elementIndex == maxElements) 1311 break; 1312 1313 InitializedEntity ElementEntity = 1314 InitializedEntity::InitializeElement(SemaRef.Context, StructuredIndex, 1315 Entity); 1316 // Check this element. 1317 CheckSubElementType(ElementEntity, IList, elementType, Index, 1318 StructuredList, StructuredIndex); 1319 ++elementIndex; 1320 1321 // If the array is of incomplete type, keep track of the number of 1322 // elements in the initializer. 1323 if (!maxElementsKnown && elementIndex > maxElements) 1324 maxElements = elementIndex; 1325 } 1326 if (!hadError && DeclType->isIncompleteArrayType() && !VerifyOnly) { 1327 // If this is an incomplete array type, the actual type needs to 1328 // be calculated here. 1329 llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned()); 1330 if (maxElements == Zero) { 1331 // Sizing an array implicitly to zero is not allowed by ISO C, 1332 // but is supported by GNU. 1333 SemaRef.Diag(IList->getLocStart(), 1334 diag::ext_typecheck_zero_array_size); 1335 } 1336 1337 DeclType = SemaRef.Context.getConstantArrayType(elementType, maxElements, 1338 ArrayType::Normal, 0); 1339 } 1340 if (!hadError && VerifyOnly) { 1341 // Check if there are any members of the array that get value-initialized. 1342 // If so, check if doing that is possible. 1343 // FIXME: This needs to detect holes left by designated initializers too. 1344 if (maxElementsKnown && elementIndex < maxElements) 1345 CheckValueInitializable(InitializedEntity::InitializeElement( 1346 SemaRef.Context, 0, Entity)); 1347 } 1348} 1349 1350bool InitListChecker::CheckFlexibleArrayInit(const InitializedEntity &Entity, 1351 Expr *InitExpr, 1352 FieldDecl *Field, 1353 bool TopLevelObject) { 1354 // Handle GNU flexible array initializers. 1355 unsigned FlexArrayDiag; 1356 if (isa<InitListExpr>(InitExpr) && 1357 cast<InitListExpr>(InitExpr)->getNumInits() == 0) { 1358 // Empty flexible array init always allowed as an extension 1359 FlexArrayDiag = diag::ext_flexible_array_init; 1360 } else if (SemaRef.getLangOpts().CPlusPlus) { 1361 // Disallow flexible array init in C++; it is not required for gcc 1362 // compatibility, and it needs work to IRGen correctly in general. 1363 FlexArrayDiag = diag::err_flexible_array_init; 1364 } else if (!TopLevelObject) { 1365 // Disallow flexible array init on non-top-level object 1366 FlexArrayDiag = diag::err_flexible_array_init; 1367 } else if (Entity.getKind() != InitializedEntity::EK_Variable) { 1368 // Disallow flexible array init on anything which is not a variable. 1369 FlexArrayDiag = diag::err_flexible_array_init; 1370 } else if (cast<VarDecl>(Entity.getDecl())->hasLocalStorage()) { 1371 // Disallow flexible array init on local variables. 1372 FlexArrayDiag = diag::err_flexible_array_init; 1373 } else { 1374 // Allow other cases. 1375 FlexArrayDiag = diag::ext_flexible_array_init; 1376 } 1377 1378 if (!VerifyOnly) { 1379 SemaRef.Diag(InitExpr->getLocStart(), 1380 FlexArrayDiag) 1381 << InitExpr->getLocStart(); 1382 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1383 << Field; 1384 } 1385 1386 return FlexArrayDiag != diag::ext_flexible_array_init; 1387} 1388 1389void InitListChecker::CheckStructUnionTypes(const InitializedEntity &Entity, 1390 InitListExpr *IList, 1391 QualType DeclType, 1392 RecordDecl::field_iterator Field, 1393 bool SubobjectIsDesignatorContext, 1394 unsigned &Index, 1395 InitListExpr *StructuredList, 1396 unsigned &StructuredIndex, 1397 bool TopLevelObject) { 1398 RecordDecl* structDecl = DeclType->getAs<RecordType>()->getDecl(); 1399 1400 // If the record is invalid, some of it's members are invalid. To avoid 1401 // confusion, we forgo checking the intializer for the entire record. 1402 if (structDecl->isInvalidDecl()) { 1403 // Assume it was supposed to consume a single initializer. 1404 ++Index; 1405 hadError = true; 1406 return; 1407 } 1408 1409 if (DeclType->isUnionType() && IList->getNumInits() == 0) { 1410 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 1411 1412 // If there's a default initializer, use it. 1413 if (isa<CXXRecordDecl>(RD) && cast<CXXRecordDecl>(RD)->hasInClassInitializer()) { 1414 if (VerifyOnly) 1415 return; 1416 for (RecordDecl::field_iterator FieldEnd = RD->field_end(); 1417 Field != FieldEnd; ++Field) { 1418 if (Field->hasInClassInitializer()) { 1419 StructuredList->setInitializedFieldInUnion(*Field); 1420 // FIXME: Actually build a CXXDefaultInitExpr? 1421 return; 1422 } 1423 } 1424 } 1425 1426 // Value-initialize the first named member of the union. 1427 for (RecordDecl::field_iterator FieldEnd = RD->field_end(); 1428 Field != FieldEnd; ++Field) { 1429 if (Field->getDeclName()) { 1430 if (VerifyOnly) 1431 CheckValueInitializable( 1432 InitializedEntity::InitializeMember(*Field, &Entity)); 1433 else 1434 StructuredList->setInitializedFieldInUnion(*Field); 1435 break; 1436 } 1437 } 1438 return; 1439 } 1440 1441 // If structDecl is a forward declaration, this loop won't do 1442 // anything except look at designated initializers; That's okay, 1443 // because an error should get printed out elsewhere. It might be 1444 // worthwhile to skip over the rest of the initializer, though. 1445 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 1446 RecordDecl::field_iterator FieldEnd = RD->field_end(); 1447 bool InitializedSomething = false; 1448 bool CheckForMissingFields = true; 1449 while (Index < IList->getNumInits()) { 1450 Expr *Init = IList->getInit(Index); 1451 1452 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) { 1453 // If we're not the subobject that matches up with the '{' for 1454 // the designator, we shouldn't be handling the 1455 // designator. Return immediately. 1456 if (!SubobjectIsDesignatorContext) 1457 return; 1458 1459 // Handle this designated initializer. Field will be updated to 1460 // the next field that we'll be initializing. 1461 if (CheckDesignatedInitializer(Entity, IList, DIE, 0, 1462 DeclType, &Field, 0, Index, 1463 StructuredList, StructuredIndex, 1464 true, TopLevelObject)) 1465 hadError = true; 1466 1467 InitializedSomething = true; 1468 1469 // Disable check for missing fields when designators are used. 1470 // This matches gcc behaviour. 1471 CheckForMissingFields = false; 1472 continue; 1473 } 1474 1475 if (Field == FieldEnd) { 1476 // We've run out of fields. We're done. 1477 break; 1478 } 1479 1480 // We've already initialized a member of a union. We're done. 1481 if (InitializedSomething && DeclType->isUnionType()) 1482 break; 1483 1484 // If we've hit the flexible array member at the end, we're done. 1485 if (Field->getType()->isIncompleteArrayType()) 1486 break; 1487 1488 if (Field->isUnnamedBitfield()) { 1489 // Don't initialize unnamed bitfields, e.g. "int : 20;" 1490 ++Field; 1491 continue; 1492 } 1493 1494 // Make sure we can use this declaration. 1495 bool InvalidUse; 1496 if (VerifyOnly) 1497 InvalidUse = !SemaRef.CanUseDecl(*Field); 1498 else 1499 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, 1500 IList->getInit(Index)->getLocStart()); 1501 if (InvalidUse) { 1502 ++Index; 1503 ++Field; 1504 hadError = true; 1505 continue; 1506 } 1507 1508 InitializedEntity MemberEntity = 1509 InitializedEntity::InitializeMember(*Field, &Entity); 1510 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1511 StructuredList, StructuredIndex); 1512 InitializedSomething = true; 1513 1514 if (DeclType->isUnionType() && !VerifyOnly) { 1515 // Initialize the first field within the union. 1516 StructuredList->setInitializedFieldInUnion(*Field); 1517 } 1518 1519 ++Field; 1520 } 1521 1522 // Emit warnings for missing struct field initializers. 1523 if (!VerifyOnly && InitializedSomething && CheckForMissingFields && 1524 Field != FieldEnd && !Field->getType()->isIncompleteArrayType() && 1525 !DeclType->isUnionType()) { 1526 // It is possible we have one or more unnamed bitfields remaining. 1527 // Find first (if any) named field and emit warning. 1528 for (RecordDecl::field_iterator it = Field, end = RD->field_end(); 1529 it != end; ++it) { 1530 if (!it->isUnnamedBitfield() && !it->hasInClassInitializer()) { 1531 SemaRef.Diag(IList->getSourceRange().getEnd(), 1532 diag::warn_missing_field_initializers) << it->getName(); 1533 break; 1534 } 1535 } 1536 } 1537 1538 // Check that any remaining fields can be value-initialized. 1539 if (VerifyOnly && Field != FieldEnd && !DeclType->isUnionType() && 1540 !Field->getType()->isIncompleteArrayType()) { 1541 // FIXME: Should check for holes left by designated initializers too. 1542 for (; Field != FieldEnd && !hadError; ++Field) { 1543 if (!Field->isUnnamedBitfield() && !Field->hasInClassInitializer()) 1544 CheckValueInitializable( 1545 InitializedEntity::InitializeMember(*Field, &Entity)); 1546 } 1547 } 1548 1549 if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() || 1550 Index >= IList->getNumInits()) 1551 return; 1552 1553 if (CheckFlexibleArrayInit(Entity, IList->getInit(Index), *Field, 1554 TopLevelObject)) { 1555 hadError = true; 1556 ++Index; 1557 return; 1558 } 1559 1560 InitializedEntity MemberEntity = 1561 InitializedEntity::InitializeMember(*Field, &Entity); 1562 1563 if (isa<InitListExpr>(IList->getInit(Index))) 1564 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1565 StructuredList, StructuredIndex); 1566 else 1567 CheckImplicitInitList(MemberEntity, IList, Field->getType(), Index, 1568 StructuredList, StructuredIndex); 1569} 1570 1571/// \brief Expand a field designator that refers to a member of an 1572/// anonymous struct or union into a series of field designators that 1573/// refers to the field within the appropriate subobject. 1574/// 1575static void ExpandAnonymousFieldDesignator(Sema &SemaRef, 1576 DesignatedInitExpr *DIE, 1577 unsigned DesigIdx, 1578 IndirectFieldDecl *IndirectField) { 1579 typedef DesignatedInitExpr::Designator Designator; 1580 1581 // Build the replacement designators. 1582 SmallVector<Designator, 4> Replacements; 1583 for (IndirectFieldDecl::chain_iterator PI = IndirectField->chain_begin(), 1584 PE = IndirectField->chain_end(); PI != PE; ++PI) { 1585 if (PI + 1 == PE) 1586 Replacements.push_back(Designator((IdentifierInfo *)0, 1587 DIE->getDesignator(DesigIdx)->getDotLoc(), 1588 DIE->getDesignator(DesigIdx)->getFieldLoc())); 1589 else 1590 Replacements.push_back(Designator((IdentifierInfo *)0, SourceLocation(), 1591 SourceLocation())); 1592 assert(isa<FieldDecl>(*PI)); 1593 Replacements.back().setField(cast<FieldDecl>(*PI)); 1594 } 1595 1596 // Expand the current designator into the set of replacement 1597 // designators, so we have a full subobject path down to where the 1598 // member of the anonymous struct/union is actually stored. 1599 DIE->ExpandDesignator(SemaRef.Context, DesigIdx, &Replacements[0], 1600 &Replacements[0] + Replacements.size()); 1601} 1602 1603/// \brief Given an implicit anonymous field, search the IndirectField that 1604/// corresponds to FieldName. 1605static IndirectFieldDecl *FindIndirectFieldDesignator(FieldDecl *AnonField, 1606 IdentifierInfo *FieldName) { 1607 if (!FieldName) 1608 return 0; 1609 1610 assert(AnonField->isAnonymousStructOrUnion()); 1611 Decl *NextDecl = AnonField->getNextDeclInContext(); 1612 while (IndirectFieldDecl *IF = 1613 dyn_cast_or_null<IndirectFieldDecl>(NextDecl)) { 1614 if (FieldName == IF->getAnonField()->getIdentifier()) 1615 return IF; 1616 NextDecl = NextDecl->getNextDeclInContext(); 1617 } 1618 return 0; 1619} 1620 1621static DesignatedInitExpr *CloneDesignatedInitExpr(Sema &SemaRef, 1622 DesignatedInitExpr *DIE) { 1623 unsigned NumIndexExprs = DIE->getNumSubExprs() - 1; 1624 SmallVector<Expr*, 4> IndexExprs(NumIndexExprs); 1625 for (unsigned I = 0; I < NumIndexExprs; ++I) 1626 IndexExprs[I] = DIE->getSubExpr(I + 1); 1627 return DesignatedInitExpr::Create(SemaRef.Context, DIE->designators_begin(), 1628 DIE->size(), IndexExprs, 1629 DIE->getEqualOrColonLoc(), 1630 DIE->usesGNUSyntax(), DIE->getInit()); 1631} 1632 1633namespace { 1634 1635// Callback to only accept typo corrections that are for field members of 1636// the given struct or union. 1637class FieldInitializerValidatorCCC : public CorrectionCandidateCallback { 1638 public: 1639 explicit FieldInitializerValidatorCCC(RecordDecl *RD) 1640 : Record(RD) {} 1641 1642 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 1643 FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>(); 1644 return FD && FD->getDeclContext()->getRedeclContext()->Equals(Record); 1645 } 1646 1647 private: 1648 RecordDecl *Record; 1649}; 1650 1651} 1652 1653/// @brief Check the well-formedness of a C99 designated initializer. 1654/// 1655/// Determines whether the designated initializer @p DIE, which 1656/// resides at the given @p Index within the initializer list @p 1657/// IList, is well-formed for a current object of type @p DeclType 1658/// (C99 6.7.8). The actual subobject that this designator refers to 1659/// within the current subobject is returned in either 1660/// @p NextField or @p NextElementIndex (whichever is appropriate). 1661/// 1662/// @param IList The initializer list in which this designated 1663/// initializer occurs. 1664/// 1665/// @param DIE The designated initializer expression. 1666/// 1667/// @param DesigIdx The index of the current designator. 1668/// 1669/// @param CurrentObjectType The type of the "current object" (C99 6.7.8p17), 1670/// into which the designation in @p DIE should refer. 1671/// 1672/// @param NextField If non-NULL and the first designator in @p DIE is 1673/// a field, this will be set to the field declaration corresponding 1674/// to the field named by the designator. 1675/// 1676/// @param NextElementIndex If non-NULL and the first designator in @p 1677/// DIE is an array designator or GNU array-range designator, this 1678/// will be set to the last index initialized by this designator. 1679/// 1680/// @param Index Index into @p IList where the designated initializer 1681/// @p DIE occurs. 1682/// 1683/// @param StructuredList The initializer list expression that 1684/// describes all of the subobject initializers in the order they'll 1685/// actually be initialized. 1686/// 1687/// @returns true if there was an error, false otherwise. 1688bool 1689InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity, 1690 InitListExpr *IList, 1691 DesignatedInitExpr *DIE, 1692 unsigned DesigIdx, 1693 QualType &CurrentObjectType, 1694 RecordDecl::field_iterator *NextField, 1695 llvm::APSInt *NextElementIndex, 1696 unsigned &Index, 1697 InitListExpr *StructuredList, 1698 unsigned &StructuredIndex, 1699 bool FinishSubobjectInit, 1700 bool TopLevelObject) { 1701 if (DesigIdx == DIE->size()) { 1702 // Check the actual initialization for the designated object type. 1703 bool prevHadError = hadError; 1704 1705 // Temporarily remove the designator expression from the 1706 // initializer list that the child calls see, so that we don't try 1707 // to re-process the designator. 1708 unsigned OldIndex = Index; 1709 IList->setInit(OldIndex, DIE->getInit()); 1710 1711 CheckSubElementType(Entity, IList, CurrentObjectType, Index, 1712 StructuredList, StructuredIndex); 1713 1714 // Restore the designated initializer expression in the syntactic 1715 // form of the initializer list. 1716 if (IList->getInit(OldIndex) != DIE->getInit()) 1717 DIE->setInit(IList->getInit(OldIndex)); 1718 IList->setInit(OldIndex, DIE); 1719 1720 return hadError && !prevHadError; 1721 } 1722 1723 DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx); 1724 bool IsFirstDesignator = (DesigIdx == 0); 1725 if (!VerifyOnly) { 1726 assert((IsFirstDesignator || StructuredList) && 1727 "Need a non-designated initializer list to start from"); 1728 1729 // Determine the structural initializer list that corresponds to the 1730 // current subobject. 1731 StructuredList = IsFirstDesignator? SyntacticToSemantic.lookup(IList) 1732 : getStructuredSubobjectInit(IList, Index, CurrentObjectType, 1733 StructuredList, StructuredIndex, 1734 SourceRange(D->getLocStart(), 1735 DIE->getLocEnd())); 1736 assert(StructuredList && "Expected a structured initializer list"); 1737 } 1738 1739 if (D->isFieldDesignator()) { 1740 // C99 6.7.8p7: 1741 // 1742 // If a designator has the form 1743 // 1744 // . identifier 1745 // 1746 // then the current object (defined below) shall have 1747 // structure or union type and the identifier shall be the 1748 // name of a member of that type. 1749 const RecordType *RT = CurrentObjectType->getAs<RecordType>(); 1750 if (!RT) { 1751 SourceLocation Loc = D->getDotLoc(); 1752 if (Loc.isInvalid()) 1753 Loc = D->getFieldLoc(); 1754 if (!VerifyOnly) 1755 SemaRef.Diag(Loc, diag::err_field_designator_non_aggr) 1756 << SemaRef.getLangOpts().CPlusPlus << CurrentObjectType; 1757 ++Index; 1758 return true; 1759 } 1760 1761 // Note: we perform a linear search of the fields here, despite 1762 // the fact that we have a faster lookup method, because we always 1763 // need to compute the field's index. 1764 FieldDecl *KnownField = D->getField(); 1765 IdentifierInfo *FieldName = D->getFieldName(); 1766 unsigned FieldIndex = 0; 1767 RecordDecl::field_iterator 1768 Field = RT->getDecl()->field_begin(), 1769 FieldEnd = RT->getDecl()->field_end(); 1770 for (; Field != FieldEnd; ++Field) { 1771 if (Field->isUnnamedBitfield()) 1772 continue; 1773 1774 // If we find a field representing an anonymous field, look in the 1775 // IndirectFieldDecl that follow for the designated initializer. 1776 if (!KnownField && Field->isAnonymousStructOrUnion()) { 1777 if (IndirectFieldDecl *IF = 1778 FindIndirectFieldDesignator(*Field, FieldName)) { 1779 // In verify mode, don't modify the original. 1780 if (VerifyOnly) 1781 DIE = CloneDesignatedInitExpr(SemaRef, DIE); 1782 ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IF); 1783 D = DIE->getDesignator(DesigIdx); 1784 break; 1785 } 1786 } 1787 if (KnownField && KnownField == *Field) 1788 break; 1789 if (FieldName && FieldName == Field->getIdentifier()) 1790 break; 1791 1792 ++FieldIndex; 1793 } 1794 1795 if (Field == FieldEnd) { 1796 if (VerifyOnly) { 1797 ++Index; 1798 return true; // No typo correction when just trying this out. 1799 } 1800 1801 // There was no normal field in the struct with the designated 1802 // name. Perform another lookup for this name, which may find 1803 // something that we can't designate (e.g., a member function), 1804 // may find nothing, or may find a member of an anonymous 1805 // struct/union. 1806 DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName); 1807 FieldDecl *ReplacementField = 0; 1808 if (Lookup.empty()) { 1809 // Name lookup didn't find anything. Determine whether this 1810 // was a typo for another field name. 1811 FieldInitializerValidatorCCC Validator(RT->getDecl()); 1812 TypoCorrection Corrected = SemaRef.CorrectTypo( 1813 DeclarationNameInfo(FieldName, D->getFieldLoc()), 1814 Sema::LookupMemberName, /*Scope=*/0, /*SS=*/0, Validator, 1815 RT->getDecl()); 1816 if (Corrected) { 1817 std::string CorrectedStr( 1818 Corrected.getAsString(SemaRef.getLangOpts())); 1819 std::string CorrectedQuotedStr( 1820 Corrected.getQuoted(SemaRef.getLangOpts())); 1821 ReplacementField = Corrected.getCorrectionDeclAs<FieldDecl>(); 1822 SemaRef.Diag(D->getFieldLoc(), 1823 diag::err_field_designator_unknown_suggest) 1824 << FieldName << CurrentObjectType << CorrectedQuotedStr 1825 << FixItHint::CreateReplacement(D->getFieldLoc(), CorrectedStr); 1826 SemaRef.Diag(ReplacementField->getLocation(), 1827 diag::note_previous_decl) << CorrectedQuotedStr; 1828 hadError = true; 1829 } else { 1830 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown) 1831 << FieldName << CurrentObjectType; 1832 ++Index; 1833 return true; 1834 } 1835 } 1836 1837 if (!ReplacementField) { 1838 // Name lookup found something, but it wasn't a field. 1839 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield) 1840 << FieldName; 1841 SemaRef.Diag(Lookup.front()->getLocation(), 1842 diag::note_field_designator_found); 1843 ++Index; 1844 return true; 1845 } 1846 1847 if (!KnownField) { 1848 // The replacement field comes from typo correction; find it 1849 // in the list of fields. 1850 FieldIndex = 0; 1851 Field = RT->getDecl()->field_begin(); 1852 for (; Field != FieldEnd; ++Field) { 1853 if (Field->isUnnamedBitfield()) 1854 continue; 1855 1856 if (ReplacementField == *Field || 1857 Field->getIdentifier() == ReplacementField->getIdentifier()) 1858 break; 1859 1860 ++FieldIndex; 1861 } 1862 } 1863 } 1864 1865 // All of the fields of a union are located at the same place in 1866 // the initializer list. 1867 if (RT->getDecl()->isUnion()) { 1868 FieldIndex = 0; 1869 if (!VerifyOnly) 1870 StructuredList->setInitializedFieldInUnion(*Field); 1871 } 1872 1873 // Make sure we can use this declaration. 1874 bool InvalidUse; 1875 if (VerifyOnly) 1876 InvalidUse = !SemaRef.CanUseDecl(*Field); 1877 else 1878 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc()); 1879 if (InvalidUse) { 1880 ++Index; 1881 return true; 1882 } 1883 1884 if (!VerifyOnly) { 1885 // Update the designator with the field declaration. 1886 D->setField(*Field); 1887 1888 // Make sure that our non-designated initializer list has space 1889 // for a subobject corresponding to this field. 1890 if (FieldIndex >= StructuredList->getNumInits()) 1891 StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1); 1892 } 1893 1894 // This designator names a flexible array member. 1895 if (Field->getType()->isIncompleteArrayType()) { 1896 bool Invalid = false; 1897 if ((DesigIdx + 1) != DIE->size()) { 1898 // We can't designate an object within the flexible array 1899 // member (because GCC doesn't allow it). 1900 if (!VerifyOnly) { 1901 DesignatedInitExpr::Designator *NextD 1902 = DIE->getDesignator(DesigIdx + 1); 1903 SemaRef.Diag(NextD->getLocStart(), 1904 diag::err_designator_into_flexible_array_member) 1905 << SourceRange(NextD->getLocStart(), 1906 DIE->getLocEnd()); 1907 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1908 << *Field; 1909 } 1910 Invalid = true; 1911 } 1912 1913 if (!hadError && !isa<InitListExpr>(DIE->getInit()) && 1914 !isa<StringLiteral>(DIE->getInit())) { 1915 // The initializer is not an initializer list. 1916 if (!VerifyOnly) { 1917 SemaRef.Diag(DIE->getInit()->getLocStart(), 1918 diag::err_flexible_array_init_needs_braces) 1919 << DIE->getInit()->getSourceRange(); 1920 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1921 << *Field; 1922 } 1923 Invalid = true; 1924 } 1925 1926 // Check GNU flexible array initializer. 1927 if (!Invalid && CheckFlexibleArrayInit(Entity, DIE->getInit(), *Field, 1928 TopLevelObject)) 1929 Invalid = true; 1930 1931 if (Invalid) { 1932 ++Index; 1933 return true; 1934 } 1935 1936 // Initialize the array. 1937 bool prevHadError = hadError; 1938 unsigned newStructuredIndex = FieldIndex; 1939 unsigned OldIndex = Index; 1940 IList->setInit(Index, DIE->getInit()); 1941 1942 InitializedEntity MemberEntity = 1943 InitializedEntity::InitializeMember(*Field, &Entity); 1944 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1945 StructuredList, newStructuredIndex); 1946 1947 IList->setInit(OldIndex, DIE); 1948 if (hadError && !prevHadError) { 1949 ++Field; 1950 ++FieldIndex; 1951 if (NextField) 1952 *NextField = Field; 1953 StructuredIndex = FieldIndex; 1954 return true; 1955 } 1956 } else { 1957 // Recurse to check later designated subobjects. 1958 QualType FieldType = Field->getType(); 1959 unsigned newStructuredIndex = FieldIndex; 1960 1961 InitializedEntity MemberEntity = 1962 InitializedEntity::InitializeMember(*Field, &Entity); 1963 if (CheckDesignatedInitializer(MemberEntity, IList, DIE, DesigIdx + 1, 1964 FieldType, 0, 0, Index, 1965 StructuredList, newStructuredIndex, 1966 true, false)) 1967 return true; 1968 } 1969 1970 // Find the position of the next field to be initialized in this 1971 // subobject. 1972 ++Field; 1973 ++FieldIndex; 1974 1975 // If this the first designator, our caller will continue checking 1976 // the rest of this struct/class/union subobject. 1977 if (IsFirstDesignator) { 1978 if (NextField) 1979 *NextField = Field; 1980 StructuredIndex = FieldIndex; 1981 return false; 1982 } 1983 1984 if (!FinishSubobjectInit) 1985 return false; 1986 1987 // We've already initialized something in the union; we're done. 1988 if (RT->getDecl()->isUnion()) 1989 return hadError; 1990 1991 // Check the remaining fields within this class/struct/union subobject. 1992 bool prevHadError = hadError; 1993 1994 CheckStructUnionTypes(Entity, IList, CurrentObjectType, Field, false, Index, 1995 StructuredList, FieldIndex); 1996 return hadError && !prevHadError; 1997 } 1998 1999 // C99 6.7.8p6: 2000 // 2001 // If a designator has the form 2002 // 2003 // [ constant-expression ] 2004 // 2005 // then the current object (defined below) shall have array 2006 // type and the expression shall be an integer constant 2007 // expression. If the array is of unknown size, any 2008 // nonnegative value is valid. 2009 // 2010 // Additionally, cope with the GNU extension that permits 2011 // designators of the form 2012 // 2013 // [ constant-expression ... constant-expression ] 2014 const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType); 2015 if (!AT) { 2016 if (!VerifyOnly) 2017 SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array) 2018 << CurrentObjectType; 2019 ++Index; 2020 return true; 2021 } 2022 2023 Expr *IndexExpr = 0; 2024 llvm::APSInt DesignatedStartIndex, DesignatedEndIndex; 2025 if (D->isArrayDesignator()) { 2026 IndexExpr = DIE->getArrayIndex(*D); 2027 DesignatedStartIndex = IndexExpr->EvaluateKnownConstInt(SemaRef.Context); 2028 DesignatedEndIndex = DesignatedStartIndex; 2029 } else { 2030 assert(D->isArrayRangeDesignator() && "Need array-range designator"); 2031 2032 DesignatedStartIndex = 2033 DIE->getArrayRangeStart(*D)->EvaluateKnownConstInt(SemaRef.Context); 2034 DesignatedEndIndex = 2035 DIE->getArrayRangeEnd(*D)->EvaluateKnownConstInt(SemaRef.Context); 2036 IndexExpr = DIE->getArrayRangeEnd(*D); 2037 2038 // Codegen can't handle evaluating array range designators that have side 2039 // effects, because we replicate the AST value for each initialized element. 2040 // As such, set the sawArrayRangeDesignator() bit if we initialize multiple 2041 // elements with something that has a side effect, so codegen can emit an 2042 // "error unsupported" error instead of miscompiling the app. 2043 if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&& 2044 DIE->getInit()->HasSideEffects(SemaRef.Context) && !VerifyOnly) 2045 FullyStructuredList->sawArrayRangeDesignator(); 2046 } 2047 2048 if (isa<ConstantArrayType>(AT)) { 2049 llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false); 2050 DesignatedStartIndex 2051 = DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth()); 2052 DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned()); 2053 DesignatedEndIndex 2054 = DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth()); 2055 DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned()); 2056 if (DesignatedEndIndex >= MaxElements) { 2057 if (!VerifyOnly) 2058 SemaRef.Diag(IndexExpr->getLocStart(), 2059 diag::err_array_designator_too_large) 2060 << DesignatedEndIndex.toString(10) << MaxElements.toString(10) 2061 << IndexExpr->getSourceRange(); 2062 ++Index; 2063 return true; 2064 } 2065 } else { 2066 // Make sure the bit-widths and signedness match. 2067 if (DesignatedStartIndex.getBitWidth() > DesignatedEndIndex.getBitWidth()) 2068 DesignatedEndIndex 2069 = DesignatedEndIndex.extend(DesignatedStartIndex.getBitWidth()); 2070 else if (DesignatedStartIndex.getBitWidth() < 2071 DesignatedEndIndex.getBitWidth()) 2072 DesignatedStartIndex 2073 = DesignatedStartIndex.extend(DesignatedEndIndex.getBitWidth()); 2074 DesignatedStartIndex.setIsUnsigned(true); 2075 DesignatedEndIndex.setIsUnsigned(true); 2076 } 2077 2078 if (!VerifyOnly && StructuredList->isStringLiteralInit()) { 2079 // We're modifying a string literal init; we have to decompose the string 2080 // so we can modify the individual characters. 2081 ASTContext &Context = SemaRef.Context; 2082 Expr *SubExpr = StructuredList->getInit(0)->IgnoreParens(); 2083 2084 // Compute the character type 2085 QualType CharTy = AT->getElementType(); 2086 2087 // Compute the type of the integer literals. 2088 QualType PromotedCharTy = CharTy; 2089 if (CharTy->isPromotableIntegerType()) 2090 PromotedCharTy = Context.getPromotedIntegerType(CharTy); 2091 unsigned PromotedCharTyWidth = Context.getTypeSize(PromotedCharTy); 2092 2093 if (StringLiteral *SL = dyn_cast<StringLiteral>(SubExpr)) { 2094 // Get the length of the string. 2095 uint64_t StrLen = SL->getLength(); 2096 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen)) 2097 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue(); 2098 StructuredList->resizeInits(Context, StrLen); 2099 2100 // Build a literal for each character in the string, and put them into 2101 // the init list. 2102 for (unsigned i = 0, e = StrLen; i != e; ++i) { 2103 llvm::APInt CodeUnit(PromotedCharTyWidth, SL->getCodeUnit(i)); 2104 Expr *Init = new (Context) IntegerLiteral( 2105 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc()); 2106 if (CharTy != PromotedCharTy) 2107 Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast, 2108 Init, 0, VK_RValue); 2109 StructuredList->updateInit(Context, i, Init); 2110 } 2111 } else { 2112 ObjCEncodeExpr *E = cast<ObjCEncodeExpr>(SubExpr); 2113 std::string Str; 2114 Context.getObjCEncodingForType(E->getEncodedType(), Str); 2115 2116 // Get the length of the string. 2117 uint64_t StrLen = Str.size(); 2118 if (cast<ConstantArrayType>(AT)->getSize().ult(StrLen)) 2119 StrLen = cast<ConstantArrayType>(AT)->getSize().getZExtValue(); 2120 StructuredList->resizeInits(Context, StrLen); 2121 2122 // Build a literal for each character in the string, and put them into 2123 // the init list. 2124 for (unsigned i = 0, e = StrLen; i != e; ++i) { 2125 llvm::APInt CodeUnit(PromotedCharTyWidth, Str[i]); 2126 Expr *Init = new (Context) IntegerLiteral( 2127 Context, CodeUnit, PromotedCharTy, SubExpr->getExprLoc()); 2128 if (CharTy != PromotedCharTy) 2129 Init = ImplicitCastExpr::Create(Context, CharTy, CK_IntegralCast, 2130 Init, 0, VK_RValue); 2131 StructuredList->updateInit(Context, i, Init); 2132 } 2133 } 2134 } 2135 2136 // Make sure that our non-designated initializer list has space 2137 // for a subobject corresponding to this array element. 2138 if (!VerifyOnly && 2139 DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits()) 2140 StructuredList->resizeInits(SemaRef.Context, 2141 DesignatedEndIndex.getZExtValue() + 1); 2142 2143 // Repeatedly perform subobject initializations in the range 2144 // [DesignatedStartIndex, DesignatedEndIndex]. 2145 2146 // Move to the next designator 2147 unsigned ElementIndex = DesignatedStartIndex.getZExtValue(); 2148 unsigned OldIndex = Index; 2149 2150 InitializedEntity ElementEntity = 2151 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 2152 2153 while (DesignatedStartIndex <= DesignatedEndIndex) { 2154 // Recurse to check later designated subobjects. 2155 QualType ElementType = AT->getElementType(); 2156 Index = OldIndex; 2157 2158 ElementEntity.setElementIndex(ElementIndex); 2159 if (CheckDesignatedInitializer(ElementEntity, IList, DIE, DesigIdx + 1, 2160 ElementType, 0, 0, Index, 2161 StructuredList, ElementIndex, 2162 (DesignatedStartIndex == DesignatedEndIndex), 2163 false)) 2164 return true; 2165 2166 // Move to the next index in the array that we'll be initializing. 2167 ++DesignatedStartIndex; 2168 ElementIndex = DesignatedStartIndex.getZExtValue(); 2169 } 2170 2171 // If this the first designator, our caller will continue checking 2172 // the rest of this array subobject. 2173 if (IsFirstDesignator) { 2174 if (NextElementIndex) 2175 *NextElementIndex = DesignatedStartIndex; 2176 StructuredIndex = ElementIndex; 2177 return false; 2178 } 2179 2180 if (!FinishSubobjectInit) 2181 return false; 2182 2183 // Check the remaining elements within this array subobject. 2184 bool prevHadError = hadError; 2185 CheckArrayType(Entity, IList, CurrentObjectType, DesignatedStartIndex, 2186 /*SubobjectIsDesignatorContext=*/false, Index, 2187 StructuredList, ElementIndex); 2188 return hadError && !prevHadError; 2189} 2190 2191// Get the structured initializer list for a subobject of type 2192// @p CurrentObjectType. 2193InitListExpr * 2194InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index, 2195 QualType CurrentObjectType, 2196 InitListExpr *StructuredList, 2197 unsigned StructuredIndex, 2198 SourceRange InitRange) { 2199 if (VerifyOnly) 2200 return 0; // No structured list in verification-only mode. 2201 Expr *ExistingInit = 0; 2202 if (!StructuredList) 2203 ExistingInit = SyntacticToSemantic.lookup(IList); 2204 else if (StructuredIndex < StructuredList->getNumInits()) 2205 ExistingInit = StructuredList->getInit(StructuredIndex); 2206 2207 if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit)) 2208 return Result; 2209 2210 if (ExistingInit) { 2211 // We are creating an initializer list that initializes the 2212 // subobjects of the current object, but there was already an 2213 // initialization that completely initialized the current 2214 // subobject, e.g., by a compound literal: 2215 // 2216 // struct X { int a, b; }; 2217 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 }; 2218 // 2219 // Here, xs[0].a == 0 and xs[0].b == 3, since the second, 2220 // designated initializer re-initializes the whole 2221 // subobject [0], overwriting previous initializers. 2222 SemaRef.Diag(InitRange.getBegin(), 2223 diag::warn_subobject_initializer_overrides) 2224 << InitRange; 2225 SemaRef.Diag(ExistingInit->getLocStart(), 2226 diag::note_previous_initializer) 2227 << /*FIXME:has side effects=*/0 2228 << ExistingInit->getSourceRange(); 2229 } 2230 2231 InitListExpr *Result 2232 = new (SemaRef.Context) InitListExpr(SemaRef.Context, 2233 InitRange.getBegin(), None, 2234 InitRange.getEnd()); 2235 2236 QualType ResultType = CurrentObjectType; 2237 if (!ResultType->isArrayType()) 2238 ResultType = ResultType.getNonLValueExprType(SemaRef.Context); 2239 Result->setType(ResultType); 2240 2241 // Pre-allocate storage for the structured initializer list. 2242 unsigned NumElements = 0; 2243 unsigned NumInits = 0; 2244 bool GotNumInits = false; 2245 if (!StructuredList) { 2246 NumInits = IList->getNumInits(); 2247 GotNumInits = true; 2248 } else if (Index < IList->getNumInits()) { 2249 if (InitListExpr *SubList = dyn_cast<InitListExpr>(IList->getInit(Index))) { 2250 NumInits = SubList->getNumInits(); 2251 GotNumInits = true; 2252 } 2253 } 2254 2255 if (const ArrayType *AType 2256 = SemaRef.Context.getAsArrayType(CurrentObjectType)) { 2257 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) { 2258 NumElements = CAType->getSize().getZExtValue(); 2259 // Simple heuristic so that we don't allocate a very large 2260 // initializer with many empty entries at the end. 2261 if (GotNumInits && NumElements > NumInits) 2262 NumElements = 0; 2263 } 2264 } else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>()) 2265 NumElements = VType->getNumElements(); 2266 else if (const RecordType *RType = CurrentObjectType->getAs<RecordType>()) { 2267 RecordDecl *RDecl = RType->getDecl(); 2268 if (RDecl->isUnion()) 2269 NumElements = 1; 2270 else 2271 NumElements = std::distance(RDecl->field_begin(), 2272 RDecl->field_end()); 2273 } 2274 2275 Result->reserveInits(SemaRef.Context, NumElements); 2276 2277 // Link this new initializer list into the structured initializer 2278 // lists. 2279 if (StructuredList) 2280 StructuredList->updateInit(SemaRef.Context, StructuredIndex, Result); 2281 else { 2282 Result->setSyntacticForm(IList); 2283 SyntacticToSemantic[IList] = Result; 2284 } 2285 2286 return Result; 2287} 2288 2289/// Update the initializer at index @p StructuredIndex within the 2290/// structured initializer list to the value @p expr. 2291void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList, 2292 unsigned &StructuredIndex, 2293 Expr *expr) { 2294 // No structured initializer list to update 2295 if (!StructuredList) 2296 return; 2297 2298 if (Expr *PrevInit = StructuredList->updateInit(SemaRef.Context, 2299 StructuredIndex, expr)) { 2300 // This initializer overwrites a previous initializer. Warn. 2301 SemaRef.Diag(expr->getLocStart(), 2302 diag::warn_initializer_overrides) 2303 << expr->getSourceRange(); 2304 SemaRef.Diag(PrevInit->getLocStart(), 2305 diag::note_previous_initializer) 2306 << /*FIXME:has side effects=*/0 2307 << PrevInit->getSourceRange(); 2308 } 2309 2310 ++StructuredIndex; 2311} 2312 2313/// Check that the given Index expression is a valid array designator 2314/// value. This is essentially just a wrapper around 2315/// VerifyIntegerConstantExpression that also checks for negative values 2316/// and produces a reasonable diagnostic if there is a 2317/// failure. Returns the index expression, possibly with an implicit cast 2318/// added, on success. If everything went okay, Value will receive the 2319/// value of the constant expression. 2320static ExprResult 2321CheckArrayDesignatorExpr(Sema &S, Expr *Index, llvm::APSInt &Value) { 2322 SourceLocation Loc = Index->getLocStart(); 2323 2324 // Make sure this is an integer constant expression. 2325 ExprResult Result = S.VerifyIntegerConstantExpression(Index, &Value); 2326 if (Result.isInvalid()) 2327 return Result; 2328 2329 if (Value.isSigned() && Value.isNegative()) 2330 return S.Diag(Loc, diag::err_array_designator_negative) 2331 << Value.toString(10) << Index->getSourceRange(); 2332 2333 Value.setIsUnsigned(true); 2334 return Result; 2335} 2336 2337ExprResult Sema::ActOnDesignatedInitializer(Designation &Desig, 2338 SourceLocation Loc, 2339 bool GNUSyntax, 2340 ExprResult Init) { 2341 typedef DesignatedInitExpr::Designator ASTDesignator; 2342 2343 bool Invalid = false; 2344 SmallVector<ASTDesignator, 32> Designators; 2345 SmallVector<Expr *, 32> InitExpressions; 2346 2347 // Build designators and check array designator expressions. 2348 for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) { 2349 const Designator &D = Desig.getDesignator(Idx); 2350 switch (D.getKind()) { 2351 case Designator::FieldDesignator: 2352 Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(), 2353 D.getFieldLoc())); 2354 break; 2355 2356 case Designator::ArrayDesignator: { 2357 Expr *Index = static_cast<Expr *>(D.getArrayIndex()); 2358 llvm::APSInt IndexValue; 2359 if (!Index->isTypeDependent() && !Index->isValueDependent()) 2360 Index = CheckArrayDesignatorExpr(*this, Index, IndexValue).take(); 2361 if (!Index) 2362 Invalid = true; 2363 else { 2364 Designators.push_back(ASTDesignator(InitExpressions.size(), 2365 D.getLBracketLoc(), 2366 D.getRBracketLoc())); 2367 InitExpressions.push_back(Index); 2368 } 2369 break; 2370 } 2371 2372 case Designator::ArrayRangeDesignator: { 2373 Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart()); 2374 Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd()); 2375 llvm::APSInt StartValue; 2376 llvm::APSInt EndValue; 2377 bool StartDependent = StartIndex->isTypeDependent() || 2378 StartIndex->isValueDependent(); 2379 bool EndDependent = EndIndex->isTypeDependent() || 2380 EndIndex->isValueDependent(); 2381 if (!StartDependent) 2382 StartIndex = 2383 CheckArrayDesignatorExpr(*this, StartIndex, StartValue).take(); 2384 if (!EndDependent) 2385 EndIndex = CheckArrayDesignatorExpr(*this, EndIndex, EndValue).take(); 2386 2387 if (!StartIndex || !EndIndex) 2388 Invalid = true; 2389 else { 2390 // Make sure we're comparing values with the same bit width. 2391 if (StartDependent || EndDependent) { 2392 // Nothing to compute. 2393 } else if (StartValue.getBitWidth() > EndValue.getBitWidth()) 2394 EndValue = EndValue.extend(StartValue.getBitWidth()); 2395 else if (StartValue.getBitWidth() < EndValue.getBitWidth()) 2396 StartValue = StartValue.extend(EndValue.getBitWidth()); 2397 2398 if (!StartDependent && !EndDependent && EndValue < StartValue) { 2399 Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range) 2400 << StartValue.toString(10) << EndValue.toString(10) 2401 << StartIndex->getSourceRange() << EndIndex->getSourceRange(); 2402 Invalid = true; 2403 } else { 2404 Designators.push_back(ASTDesignator(InitExpressions.size(), 2405 D.getLBracketLoc(), 2406 D.getEllipsisLoc(), 2407 D.getRBracketLoc())); 2408 InitExpressions.push_back(StartIndex); 2409 InitExpressions.push_back(EndIndex); 2410 } 2411 } 2412 break; 2413 } 2414 } 2415 } 2416 2417 if (Invalid || Init.isInvalid()) 2418 return ExprError(); 2419 2420 // Clear out the expressions within the designation. 2421 Desig.ClearExprs(*this); 2422 2423 DesignatedInitExpr *DIE 2424 = DesignatedInitExpr::Create(Context, 2425 Designators.data(), Designators.size(), 2426 InitExpressions, Loc, GNUSyntax, 2427 Init.takeAs<Expr>()); 2428 2429 if (!getLangOpts().C99) 2430 Diag(DIE->getLocStart(), diag::ext_designated_init) 2431 << DIE->getSourceRange(); 2432 2433 return Owned(DIE); 2434} 2435 2436//===----------------------------------------------------------------------===// 2437// Initialization entity 2438//===----------------------------------------------------------------------===// 2439 2440InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index, 2441 const InitializedEntity &Parent) 2442 : Parent(&Parent), Index(Index) 2443{ 2444 if (const ArrayType *AT = Context.getAsArrayType(Parent.getType())) { 2445 Kind = EK_ArrayElement; 2446 Type = AT->getElementType(); 2447 } else if (const VectorType *VT = Parent.getType()->getAs<VectorType>()) { 2448 Kind = EK_VectorElement; 2449 Type = VT->getElementType(); 2450 } else { 2451 const ComplexType *CT = Parent.getType()->getAs<ComplexType>(); 2452 assert(CT && "Unexpected type"); 2453 Kind = EK_ComplexElement; 2454 Type = CT->getElementType(); 2455 } 2456} 2457 2458InitializedEntity InitializedEntity::InitializeBase(ASTContext &Context, 2459 CXXBaseSpecifier *Base, 2460 bool IsInheritedVirtualBase) 2461{ 2462 InitializedEntity Result; 2463 Result.Kind = EK_Base; 2464 Result.Parent = 0; 2465 Result.Base = reinterpret_cast<uintptr_t>(Base); 2466 if (IsInheritedVirtualBase) 2467 Result.Base |= 0x01; 2468 2469 Result.Type = Base->getType(); 2470 return Result; 2471} 2472 2473DeclarationName InitializedEntity::getName() const { 2474 switch (getKind()) { 2475 case EK_Parameter: { 2476 ParmVarDecl *D = reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1); 2477 return (D ? D->getDeclName() : DeclarationName()); 2478 } 2479 2480 case EK_Variable: 2481 case EK_Member: 2482 return VariableOrMember->getDeclName(); 2483 2484 case EK_LambdaCapture: 2485 return Capture.Var->getDeclName(); 2486 2487 case EK_Result: 2488 case EK_Exception: 2489 case EK_New: 2490 case EK_Temporary: 2491 case EK_Base: 2492 case EK_Delegating: 2493 case EK_ArrayElement: 2494 case EK_VectorElement: 2495 case EK_ComplexElement: 2496 case EK_BlockElement: 2497 case EK_CompoundLiteralInit: 2498 return DeclarationName(); 2499 } 2500 2501 llvm_unreachable("Invalid EntityKind!"); 2502} 2503 2504DeclaratorDecl *InitializedEntity::getDecl() const { 2505 switch (getKind()) { 2506 case EK_Variable: 2507 case EK_Member: 2508 return VariableOrMember; 2509 2510 case EK_Parameter: 2511 return reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1); 2512 2513 case EK_Result: 2514 case EK_Exception: 2515 case EK_New: 2516 case EK_Temporary: 2517 case EK_Base: 2518 case EK_Delegating: 2519 case EK_ArrayElement: 2520 case EK_VectorElement: 2521 case EK_ComplexElement: 2522 case EK_BlockElement: 2523 case EK_LambdaCapture: 2524 case EK_CompoundLiteralInit: 2525 return 0; 2526 } 2527 2528 llvm_unreachable("Invalid EntityKind!"); 2529} 2530 2531bool InitializedEntity::allowsNRVO() const { 2532 switch (getKind()) { 2533 case EK_Result: 2534 case EK_Exception: 2535 return LocAndNRVO.NRVO; 2536 2537 case EK_Variable: 2538 case EK_Parameter: 2539 case EK_Member: 2540 case EK_New: 2541 case EK_Temporary: 2542 case EK_CompoundLiteralInit: 2543 case EK_Base: 2544 case EK_Delegating: 2545 case EK_ArrayElement: 2546 case EK_VectorElement: 2547 case EK_ComplexElement: 2548 case EK_BlockElement: 2549 case EK_LambdaCapture: 2550 break; 2551 } 2552 2553 return false; 2554} 2555 2556unsigned InitializedEntity::dumpImpl(raw_ostream &OS) const { 2557 assert(getParent() != this); 2558 unsigned Depth = getParent() ? getParent()->dumpImpl(OS) : 0; 2559 for (unsigned I = 0; I != Depth; ++I) 2560 OS << "`-"; 2561 2562 switch (getKind()) { 2563 case EK_Variable: OS << "Variable"; break; 2564 case EK_Parameter: OS << "Parameter"; break; 2565 case EK_Result: OS << "Result"; break; 2566 case EK_Exception: OS << "Exception"; break; 2567 case EK_Member: OS << "Member"; break; 2568 case EK_New: OS << "New"; break; 2569 case EK_Temporary: OS << "Temporary"; break; 2570 case EK_CompoundLiteralInit: OS << "CompoundLiteral";break; 2571 case EK_Base: OS << "Base"; break; 2572 case EK_Delegating: OS << "Delegating"; break; 2573 case EK_ArrayElement: OS << "ArrayElement " << Index; break; 2574 case EK_VectorElement: OS << "VectorElement " << Index; break; 2575 case EK_ComplexElement: OS << "ComplexElement " << Index; break; 2576 case EK_BlockElement: OS << "Block"; break; 2577 case EK_LambdaCapture: 2578 OS << "LambdaCapture "; 2579 getCapturedVar()->printName(OS); 2580 break; 2581 } 2582 2583 if (Decl *D = getDecl()) { 2584 OS << " "; 2585 cast<NamedDecl>(D)->printQualifiedName(OS); 2586 } 2587 2588 OS << " '" << getType().getAsString() << "'\n"; 2589 2590 return Depth + 1; 2591} 2592 2593void InitializedEntity::dump() const { 2594 dumpImpl(llvm::errs()); 2595} 2596 2597//===----------------------------------------------------------------------===// 2598// Initialization sequence 2599//===----------------------------------------------------------------------===// 2600 2601void InitializationSequence::Step::Destroy() { 2602 switch (Kind) { 2603 case SK_ResolveAddressOfOverloadedFunction: 2604 case SK_CastDerivedToBaseRValue: 2605 case SK_CastDerivedToBaseXValue: 2606 case SK_CastDerivedToBaseLValue: 2607 case SK_BindReference: 2608 case SK_BindReferenceToTemporary: 2609 case SK_ExtraneousCopyToTemporary: 2610 case SK_UserConversion: 2611 case SK_QualificationConversionRValue: 2612 case SK_QualificationConversionXValue: 2613 case SK_QualificationConversionLValue: 2614 case SK_LValueToRValue: 2615 case SK_ListInitialization: 2616 case SK_ListConstructorCall: 2617 case SK_UnwrapInitList: 2618 case SK_RewrapInitList: 2619 case SK_ConstructorInitialization: 2620 case SK_ZeroInitialization: 2621 case SK_CAssignment: 2622 case SK_StringInit: 2623 case SK_ObjCObjectConversion: 2624 case SK_ArrayInit: 2625 case SK_ParenthesizedArrayInit: 2626 case SK_PassByIndirectCopyRestore: 2627 case SK_PassByIndirectRestore: 2628 case SK_ProduceObjCObject: 2629 case SK_StdInitializerList: 2630 case SK_OCLSamplerInit: 2631 case SK_OCLZeroEvent: 2632 break; 2633 2634 case SK_ConversionSequence: 2635 delete ICS; 2636 } 2637} 2638 2639bool InitializationSequence::isDirectReferenceBinding() const { 2640 return !Steps.empty() && Steps.back().Kind == SK_BindReference; 2641} 2642 2643bool InitializationSequence::isAmbiguous() const { 2644 if (!Failed()) 2645 return false; 2646 2647 switch (getFailureKind()) { 2648 case FK_TooManyInitsForReference: 2649 case FK_ArrayNeedsInitList: 2650 case FK_ArrayNeedsInitListOrStringLiteral: 2651 case FK_ArrayNeedsInitListOrWideStringLiteral: 2652 case FK_NarrowStringIntoWideCharArray: 2653 case FK_WideStringIntoCharArray: 2654 case FK_IncompatWideStringIntoWideChar: 2655 case FK_AddressOfOverloadFailed: // FIXME: Could do better 2656 case FK_NonConstLValueReferenceBindingToTemporary: 2657 case FK_NonConstLValueReferenceBindingToUnrelated: 2658 case FK_RValueReferenceBindingToLValue: 2659 case FK_ReferenceInitDropsQualifiers: 2660 case FK_ReferenceInitFailed: 2661 case FK_ConversionFailed: 2662 case FK_ConversionFromPropertyFailed: 2663 case FK_TooManyInitsForScalar: 2664 case FK_ReferenceBindingToInitList: 2665 case FK_InitListBadDestinationType: 2666 case FK_DefaultInitOfConst: 2667 case FK_Incomplete: 2668 case FK_ArrayTypeMismatch: 2669 case FK_NonConstantArrayInit: 2670 case FK_ListInitializationFailed: 2671 case FK_VariableLengthArrayHasInitializer: 2672 case FK_PlaceholderType: 2673 case FK_InitListElementCopyFailure: 2674 case FK_ExplicitConstructor: 2675 return false; 2676 2677 case FK_ReferenceInitOverloadFailed: 2678 case FK_UserConversionOverloadFailed: 2679 case FK_ConstructorOverloadFailed: 2680 case FK_ListConstructorOverloadFailed: 2681 return FailedOverloadResult == OR_Ambiguous; 2682 } 2683 2684 llvm_unreachable("Invalid EntityKind!"); 2685} 2686 2687bool InitializationSequence::isConstructorInitialization() const { 2688 return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization; 2689} 2690 2691void 2692InitializationSequence 2693::AddAddressOverloadResolutionStep(FunctionDecl *Function, 2694 DeclAccessPair Found, 2695 bool HadMultipleCandidates) { 2696 Step S; 2697 S.Kind = SK_ResolveAddressOfOverloadedFunction; 2698 S.Type = Function->getType(); 2699 S.Function.HadMultipleCandidates = HadMultipleCandidates; 2700 S.Function.Function = Function; 2701 S.Function.FoundDecl = Found; 2702 Steps.push_back(S); 2703} 2704 2705void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType, 2706 ExprValueKind VK) { 2707 Step S; 2708 switch (VK) { 2709 case VK_RValue: S.Kind = SK_CastDerivedToBaseRValue; break; 2710 case VK_XValue: S.Kind = SK_CastDerivedToBaseXValue; break; 2711 case VK_LValue: S.Kind = SK_CastDerivedToBaseLValue; break; 2712 } 2713 S.Type = BaseType; 2714 Steps.push_back(S); 2715} 2716 2717void InitializationSequence::AddReferenceBindingStep(QualType T, 2718 bool BindingTemporary) { 2719 Step S; 2720 S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference; 2721 S.Type = T; 2722 Steps.push_back(S); 2723} 2724 2725void InitializationSequence::AddExtraneousCopyToTemporary(QualType T) { 2726 Step S; 2727 S.Kind = SK_ExtraneousCopyToTemporary; 2728 S.Type = T; 2729 Steps.push_back(S); 2730} 2731 2732void 2733InitializationSequence::AddUserConversionStep(FunctionDecl *Function, 2734 DeclAccessPair FoundDecl, 2735 QualType T, 2736 bool HadMultipleCandidates) { 2737 Step S; 2738 S.Kind = SK_UserConversion; 2739 S.Type = T; 2740 S.Function.HadMultipleCandidates = HadMultipleCandidates; 2741 S.Function.Function = Function; 2742 S.Function.FoundDecl = FoundDecl; 2743 Steps.push_back(S); 2744} 2745 2746void InitializationSequence::AddQualificationConversionStep(QualType Ty, 2747 ExprValueKind VK) { 2748 Step S; 2749 S.Kind = SK_QualificationConversionRValue; // work around a gcc warning 2750 switch (VK) { 2751 case VK_RValue: 2752 S.Kind = SK_QualificationConversionRValue; 2753 break; 2754 case VK_XValue: 2755 S.Kind = SK_QualificationConversionXValue; 2756 break; 2757 case VK_LValue: 2758 S.Kind = SK_QualificationConversionLValue; 2759 break; 2760 } 2761 S.Type = Ty; 2762 Steps.push_back(S); 2763} 2764 2765void InitializationSequence::AddLValueToRValueStep(QualType Ty) { 2766 assert(!Ty.hasQualifiers() && "rvalues may not have qualifiers"); 2767 2768 Step S; 2769 S.Kind = SK_LValueToRValue; 2770 S.Type = Ty; 2771 Steps.push_back(S); 2772} 2773 2774void InitializationSequence::AddConversionSequenceStep( 2775 const ImplicitConversionSequence &ICS, 2776 QualType T) { 2777 Step S; 2778 S.Kind = SK_ConversionSequence; 2779 S.Type = T; 2780 S.ICS = new ImplicitConversionSequence(ICS); 2781 Steps.push_back(S); 2782} 2783 2784void InitializationSequence::AddListInitializationStep(QualType T) { 2785 Step S; 2786 S.Kind = SK_ListInitialization; 2787 S.Type = T; 2788 Steps.push_back(S); 2789} 2790 2791void 2792InitializationSequence 2793::AddConstructorInitializationStep(CXXConstructorDecl *Constructor, 2794 AccessSpecifier Access, 2795 QualType T, 2796 bool HadMultipleCandidates, 2797 bool FromInitList, bool AsInitList) { 2798 Step S; 2799 S.Kind = FromInitList && !AsInitList ? SK_ListConstructorCall 2800 : SK_ConstructorInitialization; 2801 S.Type = T; 2802 S.Function.HadMultipleCandidates = HadMultipleCandidates; 2803 S.Function.Function = Constructor; 2804 S.Function.FoundDecl = DeclAccessPair::make(Constructor, Access); 2805 Steps.push_back(S); 2806} 2807 2808void InitializationSequence::AddZeroInitializationStep(QualType T) { 2809 Step S; 2810 S.Kind = SK_ZeroInitialization; 2811 S.Type = T; 2812 Steps.push_back(S); 2813} 2814 2815void InitializationSequence::AddCAssignmentStep(QualType T) { 2816 Step S; 2817 S.Kind = SK_CAssignment; 2818 S.Type = T; 2819 Steps.push_back(S); 2820} 2821 2822void InitializationSequence::AddStringInitStep(QualType T) { 2823 Step S; 2824 S.Kind = SK_StringInit; 2825 S.Type = T; 2826 Steps.push_back(S); 2827} 2828 2829void InitializationSequence::AddObjCObjectConversionStep(QualType T) { 2830 Step S; 2831 S.Kind = SK_ObjCObjectConversion; 2832 S.Type = T; 2833 Steps.push_back(S); 2834} 2835 2836void InitializationSequence::AddArrayInitStep(QualType T) { 2837 Step S; 2838 S.Kind = SK_ArrayInit; 2839 S.Type = T; 2840 Steps.push_back(S); 2841} 2842 2843void InitializationSequence::AddParenthesizedArrayInitStep(QualType T) { 2844 Step S; 2845 S.Kind = SK_ParenthesizedArrayInit; 2846 S.Type = T; 2847 Steps.push_back(S); 2848} 2849 2850void InitializationSequence::AddPassByIndirectCopyRestoreStep(QualType type, 2851 bool shouldCopy) { 2852 Step s; 2853 s.Kind = (shouldCopy ? SK_PassByIndirectCopyRestore 2854 : SK_PassByIndirectRestore); 2855 s.Type = type; 2856 Steps.push_back(s); 2857} 2858 2859void InitializationSequence::AddProduceObjCObjectStep(QualType T) { 2860 Step S; 2861 S.Kind = SK_ProduceObjCObject; 2862 S.Type = T; 2863 Steps.push_back(S); 2864} 2865 2866void InitializationSequence::AddStdInitializerListConstructionStep(QualType T) { 2867 Step S; 2868 S.Kind = SK_StdInitializerList; 2869 S.Type = T; 2870 Steps.push_back(S); 2871} 2872 2873void InitializationSequence::AddOCLSamplerInitStep(QualType T) { 2874 Step S; 2875 S.Kind = SK_OCLSamplerInit; 2876 S.Type = T; 2877 Steps.push_back(S); 2878} 2879 2880void InitializationSequence::AddOCLZeroEventStep(QualType T) { 2881 Step S; 2882 S.Kind = SK_OCLZeroEvent; 2883 S.Type = T; 2884 Steps.push_back(S); 2885} 2886 2887void InitializationSequence::RewrapReferenceInitList(QualType T, 2888 InitListExpr *Syntactic) { 2889 assert(Syntactic->getNumInits() == 1 && 2890 "Can only rewrap trivial init lists."); 2891 Step S; 2892 S.Kind = SK_UnwrapInitList; 2893 S.Type = Syntactic->getInit(0)->getType(); 2894 Steps.insert(Steps.begin(), S); 2895 2896 S.Kind = SK_RewrapInitList; 2897 S.Type = T; 2898 S.WrappingSyntacticList = Syntactic; 2899 Steps.push_back(S); 2900} 2901 2902void InitializationSequence::SetOverloadFailure(FailureKind Failure, 2903 OverloadingResult Result) { 2904 setSequenceKind(FailedSequence); 2905 this->Failure = Failure; 2906 this->FailedOverloadResult = Result; 2907} 2908 2909//===----------------------------------------------------------------------===// 2910// Attempt initialization 2911//===----------------------------------------------------------------------===// 2912 2913static void MaybeProduceObjCObject(Sema &S, 2914 InitializationSequence &Sequence, 2915 const InitializedEntity &Entity) { 2916 if (!S.getLangOpts().ObjCAutoRefCount) return; 2917 2918 /// When initializing a parameter, produce the value if it's marked 2919 /// __attribute__((ns_consumed)). 2920 if (Entity.getKind() == InitializedEntity::EK_Parameter) { 2921 if (!Entity.isParameterConsumed()) 2922 return; 2923 2924 assert(Entity.getType()->isObjCRetainableType() && 2925 "consuming an object of unretainable type?"); 2926 Sequence.AddProduceObjCObjectStep(Entity.getType()); 2927 2928 /// When initializing a return value, if the return type is a 2929 /// retainable type, then returns need to immediately retain the 2930 /// object. If an autorelease is required, it will be done at the 2931 /// last instant. 2932 } else if (Entity.getKind() == InitializedEntity::EK_Result) { 2933 if (!Entity.getType()->isObjCRetainableType()) 2934 return; 2935 2936 Sequence.AddProduceObjCObjectStep(Entity.getType()); 2937 } 2938} 2939 2940static void TryListInitialization(Sema &S, 2941 const InitializedEntity &Entity, 2942 const InitializationKind &Kind, 2943 InitListExpr *InitList, 2944 InitializationSequence &Sequence); 2945 2946/// \brief When initializing from init list via constructor, handle 2947/// initialization of an object of type std::initializer_list<T>. 2948/// 2949/// \return true if we have handled initialization of an object of type 2950/// std::initializer_list<T>, false otherwise. 2951static bool TryInitializerListConstruction(Sema &S, 2952 InitListExpr *List, 2953 QualType DestType, 2954 InitializationSequence &Sequence) { 2955 QualType E; 2956 if (!S.isStdInitializerList(DestType, &E)) 2957 return false; 2958 2959 if (S.RequireCompleteType(List->getExprLoc(), E, 0)) { 2960 Sequence.setIncompleteTypeFailure(E); 2961 return true; 2962 } 2963 2964 // Try initializing a temporary array from the init list. 2965 QualType ArrayType = S.Context.getConstantArrayType( 2966 E.withConst(), llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()), 2967 List->getNumInits()), 2968 clang::ArrayType::Normal, 0); 2969 InitializedEntity HiddenArray = 2970 InitializedEntity::InitializeTemporary(ArrayType); 2971 InitializationKind Kind = 2972 InitializationKind::CreateDirectList(List->getExprLoc()); 2973 TryListInitialization(S, HiddenArray, Kind, List, Sequence); 2974 if (Sequence) 2975 Sequence.AddStdInitializerListConstructionStep(DestType); 2976 return true; 2977} 2978 2979static OverloadingResult 2980ResolveConstructorOverload(Sema &S, SourceLocation DeclLoc, 2981 MultiExprArg Args, 2982 OverloadCandidateSet &CandidateSet, 2983 ArrayRef<NamedDecl *> Ctors, 2984 OverloadCandidateSet::iterator &Best, 2985 bool CopyInitializing, bool AllowExplicit, 2986 bool OnlyListConstructors, bool InitListSyntax) { 2987 CandidateSet.clear(); 2988 2989 for (ArrayRef<NamedDecl *>::iterator 2990 Con = Ctors.begin(), ConEnd = Ctors.end(); Con != ConEnd; ++Con) { 2991 NamedDecl *D = *Con; 2992 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2993 bool SuppressUserConversions = false; 2994 2995 // Find the constructor (which may be a template). 2996 CXXConstructorDecl *Constructor = 0; 2997 FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D); 2998 if (ConstructorTmpl) 2999 Constructor = cast<CXXConstructorDecl>( 3000 ConstructorTmpl->getTemplatedDecl()); 3001 else { 3002 Constructor = cast<CXXConstructorDecl>(D); 3003 3004 // If we're performing copy initialization using a copy constructor, we 3005 // suppress user-defined conversions on the arguments. We do the same for 3006 // move constructors. 3007 if ((CopyInitializing || (InitListSyntax && Args.size() == 1)) && 3008 Constructor->isCopyOrMoveConstructor()) 3009 SuppressUserConversions = true; 3010 } 3011 3012 if (!Constructor->isInvalidDecl() && 3013 (AllowExplicit || !Constructor->isExplicit()) && 3014 (!OnlyListConstructors || S.isInitListConstructor(Constructor))) { 3015 if (ConstructorTmpl) 3016 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3017 /*ExplicitArgs*/ 0, Args, 3018 CandidateSet, SuppressUserConversions); 3019 else { 3020 // C++ [over.match.copy]p1: 3021 // - When initializing a temporary to be bound to the first parameter 3022 // of a constructor that takes a reference to possibly cv-qualified 3023 // T as its first argument, called with a single argument in the 3024 // context of direct-initialization, explicit conversion functions 3025 // are also considered. 3026 bool AllowExplicitConv = AllowExplicit && !CopyInitializing && 3027 Args.size() == 1 && 3028 Constructor->isCopyOrMoveConstructor(); 3029 S.AddOverloadCandidate(Constructor, FoundDecl, Args, CandidateSet, 3030 SuppressUserConversions, 3031 /*PartialOverloading=*/false, 3032 /*AllowExplicit=*/AllowExplicitConv); 3033 } 3034 } 3035 } 3036 3037 // Perform overload resolution and return the result. 3038 return CandidateSet.BestViableFunction(S, DeclLoc, Best); 3039} 3040 3041/// \brief Attempt initialization by constructor (C++ [dcl.init]), which 3042/// enumerates the constructors of the initialized entity and performs overload 3043/// resolution to select the best. 3044/// If InitListSyntax is true, this is list-initialization of a non-aggregate 3045/// class type. 3046static void TryConstructorInitialization(Sema &S, 3047 const InitializedEntity &Entity, 3048 const InitializationKind &Kind, 3049 MultiExprArg Args, QualType DestType, 3050 InitializationSequence &Sequence, 3051 bool InitListSyntax = false) { 3052 assert((!InitListSyntax || (Args.size() == 1 && isa<InitListExpr>(Args[0]))) && 3053 "InitListSyntax must come with a single initializer list argument."); 3054 3055 // The type we're constructing needs to be complete. 3056 if (S.RequireCompleteType(Kind.getLocation(), DestType, 0)) { 3057 Sequence.setIncompleteTypeFailure(DestType); 3058 return; 3059 } 3060 3061 const RecordType *DestRecordType = DestType->getAs<RecordType>(); 3062 assert(DestRecordType && "Constructor initialization requires record type"); 3063 CXXRecordDecl *DestRecordDecl 3064 = cast<CXXRecordDecl>(DestRecordType->getDecl()); 3065 3066 // Build the candidate set directly in the initialization sequence 3067 // structure, so that it will persist if we fail. 3068 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 3069 3070 // Determine whether we are allowed to call explicit constructors or 3071 // explicit conversion operators. 3072 bool AllowExplicit = Kind.AllowExplicit() || InitListSyntax; 3073 bool CopyInitialization = Kind.getKind() == InitializationKind::IK_Copy; 3074 3075 // - Otherwise, if T is a class type, constructors are considered. The 3076 // applicable constructors are enumerated, and the best one is chosen 3077 // through overload resolution. 3078 DeclContext::lookup_result R = S.LookupConstructors(DestRecordDecl); 3079 // The container holding the constructors can under certain conditions 3080 // be changed while iterating (e.g. because of deserialization). 3081 // To be safe we copy the lookup results to a new container. 3082 SmallVector<NamedDecl*, 16> Ctors(R.begin(), R.end()); 3083 3084 OverloadingResult Result = OR_No_Viable_Function; 3085 OverloadCandidateSet::iterator Best; 3086 bool AsInitializerList = false; 3087 3088 // C++11 [over.match.list]p1: 3089 // When objects of non-aggregate type T are list-initialized, overload 3090 // resolution selects the constructor in two phases: 3091 // - Initially, the candidate functions are the initializer-list 3092 // constructors of the class T and the argument list consists of the 3093 // initializer list as a single argument. 3094 if (InitListSyntax) { 3095 InitListExpr *ILE = cast<InitListExpr>(Args[0]); 3096 AsInitializerList = true; 3097 3098 // If the initializer list has no elements and T has a default constructor, 3099 // the first phase is omitted. 3100 if (ILE->getNumInits() != 0 || !DestRecordDecl->hasDefaultConstructor()) 3101 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args, 3102 CandidateSet, Ctors, Best, 3103 CopyInitialization, AllowExplicit, 3104 /*OnlyListConstructor=*/true, 3105 InitListSyntax); 3106 3107 // Time to unwrap the init list. 3108 Args = MultiExprArg(ILE->getInits(), ILE->getNumInits()); 3109 } 3110 3111 // C++11 [over.match.list]p1: 3112 // - If no viable initializer-list constructor is found, overload resolution 3113 // is performed again, where the candidate functions are all the 3114 // constructors of the class T and the argument list consists of the 3115 // elements of the initializer list. 3116 if (Result == OR_No_Viable_Function) { 3117 AsInitializerList = false; 3118 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args, 3119 CandidateSet, Ctors, Best, 3120 CopyInitialization, AllowExplicit, 3121 /*OnlyListConstructors=*/false, 3122 InitListSyntax); 3123 } 3124 if (Result) { 3125 Sequence.SetOverloadFailure(InitListSyntax ? 3126 InitializationSequence::FK_ListConstructorOverloadFailed : 3127 InitializationSequence::FK_ConstructorOverloadFailed, 3128 Result); 3129 return; 3130 } 3131 3132 // C++11 [dcl.init]p6: 3133 // If a program calls for the default initialization of an object 3134 // of a const-qualified type T, T shall be a class type with a 3135 // user-provided default constructor. 3136 if (Kind.getKind() == InitializationKind::IK_Default && 3137 Entity.getType().isConstQualified() && 3138 !cast<CXXConstructorDecl>(Best->Function)->isUserProvided()) { 3139 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst); 3140 return; 3141 } 3142 3143 // C++11 [over.match.list]p1: 3144 // In copy-list-initialization, if an explicit constructor is chosen, the 3145 // initializer is ill-formed. 3146 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function); 3147 if (InitListSyntax && !Kind.AllowExplicit() && CtorDecl->isExplicit()) { 3148 Sequence.SetFailed(InitializationSequence::FK_ExplicitConstructor); 3149 return; 3150 } 3151 3152 // Add the constructor initialization step. Any cv-qualification conversion is 3153 // subsumed by the initialization. 3154 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3155 Sequence.AddConstructorInitializationStep(CtorDecl, 3156 Best->FoundDecl.getAccess(), 3157 DestType, HadMultipleCandidates, 3158 InitListSyntax, AsInitializerList); 3159} 3160 3161static bool 3162ResolveOverloadedFunctionForReferenceBinding(Sema &S, 3163 Expr *Initializer, 3164 QualType &SourceType, 3165 QualType &UnqualifiedSourceType, 3166 QualType UnqualifiedTargetType, 3167 InitializationSequence &Sequence) { 3168 if (S.Context.getCanonicalType(UnqualifiedSourceType) == 3169 S.Context.OverloadTy) { 3170 DeclAccessPair Found; 3171 bool HadMultipleCandidates = false; 3172 if (FunctionDecl *Fn 3173 = S.ResolveAddressOfOverloadedFunction(Initializer, 3174 UnqualifiedTargetType, 3175 false, Found, 3176 &HadMultipleCandidates)) { 3177 Sequence.AddAddressOverloadResolutionStep(Fn, Found, 3178 HadMultipleCandidates); 3179 SourceType = Fn->getType(); 3180 UnqualifiedSourceType = SourceType.getUnqualifiedType(); 3181 } else if (!UnqualifiedTargetType->isRecordType()) { 3182 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 3183 return true; 3184 } 3185 } 3186 return false; 3187} 3188 3189static void TryReferenceInitializationCore(Sema &S, 3190 const InitializedEntity &Entity, 3191 const InitializationKind &Kind, 3192 Expr *Initializer, 3193 QualType cv1T1, QualType T1, 3194 Qualifiers T1Quals, 3195 QualType cv2T2, QualType T2, 3196 Qualifiers T2Quals, 3197 InitializationSequence &Sequence); 3198 3199static void TryValueInitialization(Sema &S, 3200 const InitializedEntity &Entity, 3201 const InitializationKind &Kind, 3202 InitializationSequence &Sequence, 3203 InitListExpr *InitList = 0); 3204 3205/// \brief Attempt list initialization of a reference. 3206static void TryReferenceListInitialization(Sema &S, 3207 const InitializedEntity &Entity, 3208 const InitializationKind &Kind, 3209 InitListExpr *InitList, 3210 InitializationSequence &Sequence) { 3211 // First, catch C++03 where this isn't possible. 3212 if (!S.getLangOpts().CPlusPlus11) { 3213 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList); 3214 return; 3215 } 3216 3217 QualType DestType = Entity.getType(); 3218 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 3219 Qualifiers T1Quals; 3220 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals); 3221 3222 // Reference initialization via an initializer list works thus: 3223 // If the initializer list consists of a single element that is 3224 // reference-related to the referenced type, bind directly to that element 3225 // (possibly creating temporaries). 3226 // Otherwise, initialize a temporary with the initializer list and 3227 // bind to that. 3228 if (InitList->getNumInits() == 1) { 3229 Expr *Initializer = InitList->getInit(0); 3230 QualType cv2T2 = Initializer->getType(); 3231 Qualifiers T2Quals; 3232 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals); 3233 3234 // If this fails, creating a temporary wouldn't work either. 3235 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2, 3236 T1, Sequence)) 3237 return; 3238 3239 SourceLocation DeclLoc = Initializer->getLocStart(); 3240 bool dummy1, dummy2, dummy3; 3241 Sema::ReferenceCompareResult RefRelationship 3242 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, dummy1, 3243 dummy2, dummy3); 3244 if (RefRelationship >= Sema::Ref_Related) { 3245 // Try to bind the reference here. 3246 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1, 3247 T1Quals, cv2T2, T2, T2Quals, Sequence); 3248 if (Sequence) 3249 Sequence.RewrapReferenceInitList(cv1T1, InitList); 3250 return; 3251 } 3252 3253 // Update the initializer if we've resolved an overloaded function. 3254 if (Sequence.step_begin() != Sequence.step_end()) 3255 Sequence.RewrapReferenceInitList(cv1T1, InitList); 3256 } 3257 3258 // Not reference-related. Create a temporary and bind to that. 3259 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1); 3260 3261 TryListInitialization(S, TempEntity, Kind, InitList, Sequence); 3262 if (Sequence) { 3263 if (DestType->isRValueReferenceType() || 3264 (T1Quals.hasConst() && !T1Quals.hasVolatile())) 3265 Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true); 3266 else 3267 Sequence.SetFailed( 3268 InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary); 3269 } 3270} 3271 3272/// \brief Attempt list initialization (C++0x [dcl.init.list]) 3273static void TryListInitialization(Sema &S, 3274 const InitializedEntity &Entity, 3275 const InitializationKind &Kind, 3276 InitListExpr *InitList, 3277 InitializationSequence &Sequence) { 3278 QualType DestType = Entity.getType(); 3279 3280 // C++ doesn't allow scalar initialization with more than one argument. 3281 // But C99 complex numbers are scalars and it makes sense there. 3282 if (S.getLangOpts().CPlusPlus && DestType->isScalarType() && 3283 !DestType->isAnyComplexType() && InitList->getNumInits() > 1) { 3284 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar); 3285 return; 3286 } 3287 if (DestType->isReferenceType()) { 3288 TryReferenceListInitialization(S, Entity, Kind, InitList, Sequence); 3289 return; 3290 } 3291 if (DestType->isRecordType()) { 3292 if (S.RequireCompleteType(InitList->getLocStart(), DestType, 0)) { 3293 Sequence.setIncompleteTypeFailure(DestType); 3294 return; 3295 } 3296 3297 // C++11 [dcl.init.list]p3: 3298 // - If T is an aggregate, aggregate initialization is performed. 3299 if (!DestType->isAggregateType()) { 3300 if (S.getLangOpts().CPlusPlus11) { 3301 // - Otherwise, if the initializer list has no elements and T is a 3302 // class type with a default constructor, the object is 3303 // value-initialized. 3304 if (InitList->getNumInits() == 0) { 3305 CXXRecordDecl *RD = DestType->getAsCXXRecordDecl(); 3306 if (RD->hasDefaultConstructor()) { 3307 TryValueInitialization(S, Entity, Kind, Sequence, InitList); 3308 return; 3309 } 3310 } 3311 3312 // - Otherwise, if T is a specialization of std::initializer_list<E>, 3313 // an initializer_list object constructed [...] 3314 if (TryInitializerListConstruction(S, InitList, DestType, Sequence)) 3315 return; 3316 3317 // - Otherwise, if T is a class type, constructors are considered. 3318 Expr *InitListAsExpr = InitList; 3319 TryConstructorInitialization(S, Entity, Kind, InitListAsExpr, DestType, 3320 Sequence, /*InitListSyntax*/true); 3321 } else 3322 Sequence.SetFailed( 3323 InitializationSequence::FK_InitListBadDestinationType); 3324 return; 3325 } 3326 } 3327 3328 InitListChecker CheckInitList(S, Entity, InitList, 3329 DestType, /*VerifyOnly=*/true); 3330 if (CheckInitList.HadError()) { 3331 Sequence.SetFailed(InitializationSequence::FK_ListInitializationFailed); 3332 return; 3333 } 3334 3335 // Add the list initialization step with the built init list. 3336 Sequence.AddListInitializationStep(DestType); 3337} 3338 3339/// \brief Try a reference initialization that involves calling a conversion 3340/// function. 3341static OverloadingResult TryRefInitWithConversionFunction(Sema &S, 3342 const InitializedEntity &Entity, 3343 const InitializationKind &Kind, 3344 Expr *Initializer, 3345 bool AllowRValues, 3346 InitializationSequence &Sequence) { 3347 QualType DestType = Entity.getType(); 3348 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 3349 QualType T1 = cv1T1.getUnqualifiedType(); 3350 QualType cv2T2 = Initializer->getType(); 3351 QualType T2 = cv2T2.getUnqualifiedType(); 3352 3353 bool DerivedToBase; 3354 bool ObjCConversion; 3355 bool ObjCLifetimeConversion; 3356 assert(!S.CompareReferenceRelationship(Initializer->getLocStart(), 3357 T1, T2, DerivedToBase, 3358 ObjCConversion, 3359 ObjCLifetimeConversion) && 3360 "Must have incompatible references when binding via conversion"); 3361 (void)DerivedToBase; 3362 (void)ObjCConversion; 3363 (void)ObjCLifetimeConversion; 3364 3365 // Build the candidate set directly in the initialization sequence 3366 // structure, so that it will persist if we fail. 3367 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 3368 CandidateSet.clear(); 3369 3370 // Determine whether we are allowed to call explicit constructors or 3371 // explicit conversion operators. 3372 bool AllowExplicit = Kind.AllowExplicit(); 3373 bool AllowExplicitConvs = Kind.allowExplicitConversionFunctions(); 3374 3375 const RecordType *T1RecordType = 0; 3376 if (AllowRValues && (T1RecordType = T1->getAs<RecordType>()) && 3377 !S.RequireCompleteType(Kind.getLocation(), T1, 0)) { 3378 // The type we're converting to is a class type. Enumerate its constructors 3379 // to see if there is a suitable conversion. 3380 CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl()); 3381 3382 DeclContext::lookup_result R = S.LookupConstructors(T1RecordDecl); 3383 // The container holding the constructors can under certain conditions 3384 // be changed while iterating (e.g. because of deserialization). 3385 // To be safe we copy the lookup results to a new container. 3386 SmallVector<NamedDecl*, 16> Ctors(R.begin(), R.end()); 3387 for (SmallVector<NamedDecl*, 16>::iterator 3388 CI = Ctors.begin(), CE = Ctors.end(); CI != CE; ++CI) { 3389 NamedDecl *D = *CI; 3390 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 3391 3392 // Find the constructor (which may be a template). 3393 CXXConstructorDecl *Constructor = 0; 3394 FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D); 3395 if (ConstructorTmpl) 3396 Constructor = cast<CXXConstructorDecl>( 3397 ConstructorTmpl->getTemplatedDecl()); 3398 else 3399 Constructor = cast<CXXConstructorDecl>(D); 3400 3401 if (!Constructor->isInvalidDecl() && 3402 Constructor->isConvertingConstructor(AllowExplicit)) { 3403 if (ConstructorTmpl) 3404 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3405 /*ExplicitArgs*/ 0, 3406 Initializer, CandidateSet, 3407 /*SuppressUserConversions=*/true); 3408 else 3409 S.AddOverloadCandidate(Constructor, FoundDecl, 3410 Initializer, CandidateSet, 3411 /*SuppressUserConversions=*/true); 3412 } 3413 } 3414 } 3415 if (T1RecordType && T1RecordType->getDecl()->isInvalidDecl()) 3416 return OR_No_Viable_Function; 3417 3418 const RecordType *T2RecordType = 0; 3419 if ((T2RecordType = T2->getAs<RecordType>()) && 3420 !S.RequireCompleteType(Kind.getLocation(), T2, 0)) { 3421 // The type we're converting from is a class type, enumerate its conversion 3422 // functions. 3423 CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl()); 3424 3425 std::pair<CXXRecordDecl::conversion_iterator, 3426 CXXRecordDecl::conversion_iterator> 3427 Conversions = T2RecordDecl->getVisibleConversionFunctions(); 3428 for (CXXRecordDecl::conversion_iterator 3429 I = Conversions.first, E = Conversions.second; I != E; ++I) { 3430 NamedDecl *D = *I; 3431 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3432 if (isa<UsingShadowDecl>(D)) 3433 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3434 3435 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D); 3436 CXXConversionDecl *Conv; 3437 if (ConvTemplate) 3438 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3439 else 3440 Conv = cast<CXXConversionDecl>(D); 3441 3442 // If the conversion function doesn't return a reference type, 3443 // it can't be considered for this conversion unless we're allowed to 3444 // consider rvalues. 3445 // FIXME: Do we need to make sure that we only consider conversion 3446 // candidates with reference-compatible results? That might be needed to 3447 // break recursion. 3448 if ((AllowExplicitConvs || !Conv->isExplicit()) && 3449 (AllowRValues || Conv->getConversionType()->isLValueReferenceType())){ 3450 if (ConvTemplate) 3451 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), 3452 ActingDC, Initializer, 3453 DestType, CandidateSet); 3454 else 3455 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, 3456 Initializer, DestType, CandidateSet); 3457 } 3458 } 3459 } 3460 if (T2RecordType && T2RecordType->getDecl()->isInvalidDecl()) 3461 return OR_No_Viable_Function; 3462 3463 SourceLocation DeclLoc = Initializer->getLocStart(); 3464 3465 // Perform overload resolution. If it fails, return the failed result. 3466 OverloadCandidateSet::iterator Best; 3467 if (OverloadingResult Result 3468 = CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) 3469 return Result; 3470 3471 FunctionDecl *Function = Best->Function; 3472 // This is the overload that will be used for this initialization step if we 3473 // use this initialization. Mark it as referenced. 3474 Function->setReferenced(); 3475 3476 // Compute the returned type of the conversion. 3477 if (isa<CXXConversionDecl>(Function)) 3478 T2 = Function->getResultType(); 3479 else 3480 T2 = cv1T1; 3481 3482 // Add the user-defined conversion step. 3483 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3484 Sequence.AddUserConversionStep(Function, Best->FoundDecl, 3485 T2.getNonLValueExprType(S.Context), 3486 HadMultipleCandidates); 3487 3488 // Determine whether we need to perform derived-to-base or 3489 // cv-qualification adjustments. 3490 ExprValueKind VK = VK_RValue; 3491 if (T2->isLValueReferenceType()) 3492 VK = VK_LValue; 3493 else if (const RValueReferenceType *RRef = T2->getAs<RValueReferenceType>()) 3494 VK = RRef->getPointeeType()->isFunctionType() ? VK_LValue : VK_XValue; 3495 3496 bool NewDerivedToBase = false; 3497 bool NewObjCConversion = false; 3498 bool NewObjCLifetimeConversion = false; 3499 Sema::ReferenceCompareResult NewRefRelationship 3500 = S.CompareReferenceRelationship(DeclLoc, T1, 3501 T2.getNonLValueExprType(S.Context), 3502 NewDerivedToBase, NewObjCConversion, 3503 NewObjCLifetimeConversion); 3504 if (NewRefRelationship == Sema::Ref_Incompatible) { 3505 // If the type we've converted to is not reference-related to the 3506 // type we're looking for, then there is another conversion step 3507 // we need to perform to produce a temporary of the right type 3508 // that we'll be binding to. 3509 ImplicitConversionSequence ICS; 3510 ICS.setStandard(); 3511 ICS.Standard = Best->FinalConversion; 3512 T2 = ICS.Standard.getToType(2); 3513 Sequence.AddConversionSequenceStep(ICS, T2); 3514 } else if (NewDerivedToBase) 3515 Sequence.AddDerivedToBaseCastStep( 3516 S.Context.getQualifiedType(T1, 3517 T2.getNonReferenceType().getQualifiers()), 3518 VK); 3519 else if (NewObjCConversion) 3520 Sequence.AddObjCObjectConversionStep( 3521 S.Context.getQualifiedType(T1, 3522 T2.getNonReferenceType().getQualifiers())); 3523 3524 if (cv1T1.getQualifiers() != T2.getNonReferenceType().getQualifiers()) 3525 Sequence.AddQualificationConversionStep(cv1T1, VK); 3526 3527 Sequence.AddReferenceBindingStep(cv1T1, !T2->isReferenceType()); 3528 return OR_Success; 3529} 3530 3531static void CheckCXX98CompatAccessibleCopy(Sema &S, 3532 const InitializedEntity &Entity, 3533 Expr *CurInitExpr); 3534 3535/// \brief Attempt reference initialization (C++0x [dcl.init.ref]) 3536static void TryReferenceInitialization(Sema &S, 3537 const InitializedEntity &Entity, 3538 const InitializationKind &Kind, 3539 Expr *Initializer, 3540 InitializationSequence &Sequence) { 3541 QualType DestType = Entity.getType(); 3542 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 3543 Qualifiers T1Quals; 3544 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals); 3545 QualType cv2T2 = Initializer->getType(); 3546 Qualifiers T2Quals; 3547 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals); 3548 3549 // If the initializer is the address of an overloaded function, try 3550 // to resolve the overloaded function. If all goes well, T2 is the 3551 // type of the resulting function. 3552 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2, 3553 T1, Sequence)) 3554 return; 3555 3556 // Delegate everything else to a subfunction. 3557 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1, 3558 T1Quals, cv2T2, T2, T2Quals, Sequence); 3559} 3560 3561/// Converts the target of reference initialization so that it has the 3562/// appropriate qualifiers and value kind. 3563/// 3564/// In this case, 'x' is an 'int' lvalue, but it needs to be 'const int'. 3565/// \code 3566/// int x; 3567/// const int &r = x; 3568/// \endcode 3569/// 3570/// In this case the reference is binding to a bitfield lvalue, which isn't 3571/// valid. Perform a load to create a lifetime-extended temporary instead. 3572/// \code 3573/// const int &r = someStruct.bitfield; 3574/// \endcode 3575static ExprValueKind 3576convertQualifiersAndValueKindIfNecessary(Sema &S, 3577 InitializationSequence &Sequence, 3578 Expr *Initializer, 3579 QualType cv1T1, 3580 Qualifiers T1Quals, 3581 Qualifiers T2Quals, 3582 bool IsLValueRef) { 3583 bool IsNonAddressableType = Initializer->refersToBitField() || 3584 Initializer->refersToVectorElement(); 3585 3586 if (IsNonAddressableType) { 3587 // C++11 [dcl.init.ref]p5: [...] Otherwise, the reference shall be an 3588 // lvalue reference to a non-volatile const type, or the reference shall be 3589 // an rvalue reference. 3590 // 3591 // If not, we can't make a temporary and bind to that. Give up and allow the 3592 // error to be diagnosed later. 3593 if (IsLValueRef && (!T1Quals.hasConst() || T1Quals.hasVolatile())) { 3594 assert(Initializer->isGLValue()); 3595 return Initializer->getValueKind(); 3596 } 3597 3598 // Force a load so we can materialize a temporary. 3599 Sequence.AddLValueToRValueStep(cv1T1.getUnqualifiedType()); 3600 return VK_RValue; 3601 } 3602 3603 if (T1Quals != T2Quals) { 3604 Sequence.AddQualificationConversionStep(cv1T1, 3605 Initializer->getValueKind()); 3606 } 3607 3608 return Initializer->getValueKind(); 3609} 3610 3611 3612/// \brief Reference initialization without resolving overloaded functions. 3613static void TryReferenceInitializationCore(Sema &S, 3614 const InitializedEntity &Entity, 3615 const InitializationKind &Kind, 3616 Expr *Initializer, 3617 QualType cv1T1, QualType T1, 3618 Qualifiers T1Quals, 3619 QualType cv2T2, QualType T2, 3620 Qualifiers T2Quals, 3621 InitializationSequence &Sequence) { 3622 QualType DestType = Entity.getType(); 3623 SourceLocation DeclLoc = Initializer->getLocStart(); 3624 // Compute some basic properties of the types and the initializer. 3625 bool isLValueRef = DestType->isLValueReferenceType(); 3626 bool isRValueRef = !isLValueRef; 3627 bool DerivedToBase = false; 3628 bool ObjCConversion = false; 3629 bool ObjCLifetimeConversion = false; 3630 Expr::Classification InitCategory = Initializer->Classify(S.Context); 3631 Sema::ReferenceCompareResult RefRelationship 3632 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, DerivedToBase, 3633 ObjCConversion, ObjCLifetimeConversion); 3634 3635 // C++0x [dcl.init.ref]p5: 3636 // A reference to type "cv1 T1" is initialized by an expression of type 3637 // "cv2 T2" as follows: 3638 // 3639 // - If the reference is an lvalue reference and the initializer 3640 // expression 3641 // Note the analogous bullet points for rvlaue refs to functions. Because 3642 // there are no function rvalues in C++, rvalue refs to functions are treated 3643 // like lvalue refs. 3644 OverloadingResult ConvOvlResult = OR_Success; 3645 bool T1Function = T1->isFunctionType(); 3646 if (isLValueRef || T1Function) { 3647 if (InitCategory.isLValue() && 3648 (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification || 3649 (Kind.isCStyleOrFunctionalCast() && 3650 RefRelationship == Sema::Ref_Related))) { 3651 // - is an lvalue (but is not a bit-field), and "cv1 T1" is 3652 // reference-compatible with "cv2 T2," or 3653 // 3654 // Per C++ [over.best.ics]p2, we don't diagnose whether the lvalue is a 3655 // bit-field when we're determining whether the reference initialization 3656 // can occur. However, we do pay attention to whether it is a bit-field 3657 // to decide whether we're actually binding to a temporary created from 3658 // the bit-field. 3659 if (DerivedToBase) 3660 Sequence.AddDerivedToBaseCastStep( 3661 S.Context.getQualifiedType(T1, T2Quals), 3662 VK_LValue); 3663 else if (ObjCConversion) 3664 Sequence.AddObjCObjectConversionStep( 3665 S.Context.getQualifiedType(T1, T2Quals)); 3666 3667 ExprValueKind ValueKind = 3668 convertQualifiersAndValueKindIfNecessary(S, Sequence, Initializer, 3669 cv1T1, T1Quals, T2Quals, 3670 isLValueRef); 3671 Sequence.AddReferenceBindingStep(cv1T1, ValueKind == VK_RValue); 3672 return; 3673 } 3674 3675 // - has a class type (i.e., T2 is a class type), where T1 is not 3676 // reference-related to T2, and can be implicitly converted to an 3677 // lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible 3678 // with "cv3 T3" (this conversion is selected by enumerating the 3679 // applicable conversion functions (13.3.1.6) and choosing the best 3680 // one through overload resolution (13.3)), 3681 // If we have an rvalue ref to function type here, the rhs must be 3682 // an rvalue. 3683 if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType() && 3684 (isLValueRef || InitCategory.isRValue())) { 3685 ConvOvlResult = TryRefInitWithConversionFunction(S, Entity, Kind, 3686 Initializer, 3687 /*AllowRValues=*/isRValueRef, 3688 Sequence); 3689 if (ConvOvlResult == OR_Success) 3690 return; 3691 if (ConvOvlResult != OR_No_Viable_Function) { 3692 Sequence.SetOverloadFailure( 3693 InitializationSequence::FK_ReferenceInitOverloadFailed, 3694 ConvOvlResult); 3695 } 3696 } 3697 } 3698 3699 // - Otherwise, the reference shall be an lvalue reference to a 3700 // non-volatile const type (i.e., cv1 shall be const), or the reference 3701 // shall be an rvalue reference. 3702 if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile())) { 3703 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) 3704 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 3705 else if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty()) 3706 Sequence.SetOverloadFailure( 3707 InitializationSequence::FK_ReferenceInitOverloadFailed, 3708 ConvOvlResult); 3709 else 3710 Sequence.SetFailed(InitCategory.isLValue() 3711 ? (RefRelationship == Sema::Ref_Related 3712 ? InitializationSequence::FK_ReferenceInitDropsQualifiers 3713 : InitializationSequence::FK_NonConstLValueReferenceBindingToUnrelated) 3714 : InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary); 3715 3716 return; 3717 } 3718 3719 // - If the initializer expression 3720 // - is an xvalue, class prvalue, array prvalue, or function lvalue and 3721 // "cv1 T1" is reference-compatible with "cv2 T2" 3722 // Note: functions are handled below. 3723 if (!T1Function && 3724 (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification || 3725 (Kind.isCStyleOrFunctionalCast() && 3726 RefRelationship == Sema::Ref_Related)) && 3727 (InitCategory.isXValue() || 3728 (InitCategory.isPRValue() && T2->isRecordType()) || 3729 (InitCategory.isPRValue() && T2->isArrayType()))) { 3730 ExprValueKind ValueKind = InitCategory.isXValue()? VK_XValue : VK_RValue; 3731 if (InitCategory.isPRValue() && T2->isRecordType()) { 3732 // The corresponding bullet in C++03 [dcl.init.ref]p5 gives the 3733 // compiler the freedom to perform a copy here or bind to the 3734 // object, while C++0x requires that we bind directly to the 3735 // object. Hence, we always bind to the object without making an 3736 // extra copy. However, in C++03 requires that we check for the 3737 // presence of a suitable copy constructor: 3738 // 3739 // The constructor that would be used to make the copy shall 3740 // be callable whether or not the copy is actually done. 3741 if (!S.getLangOpts().CPlusPlus11 && !S.getLangOpts().MicrosoftExt) 3742 Sequence.AddExtraneousCopyToTemporary(cv2T2); 3743 else if (S.getLangOpts().CPlusPlus11) 3744 CheckCXX98CompatAccessibleCopy(S, Entity, Initializer); 3745 } 3746 3747 if (DerivedToBase) 3748 Sequence.AddDerivedToBaseCastStep(S.Context.getQualifiedType(T1, T2Quals), 3749 ValueKind); 3750 else if (ObjCConversion) 3751 Sequence.AddObjCObjectConversionStep( 3752 S.Context.getQualifiedType(T1, T2Quals)); 3753 3754 ValueKind = convertQualifiersAndValueKindIfNecessary(S, Sequence, 3755 Initializer, cv1T1, 3756 T1Quals, T2Quals, 3757 isLValueRef); 3758 3759 Sequence.AddReferenceBindingStep(cv1T1, ValueKind == VK_RValue); 3760 return; 3761 } 3762 3763 // - has a class type (i.e., T2 is a class type), where T1 is not 3764 // reference-related to T2, and can be implicitly converted to an 3765 // xvalue, class prvalue, or function lvalue of type "cv3 T3", 3766 // where "cv1 T1" is reference-compatible with "cv3 T3", 3767 if (T2->isRecordType()) { 3768 if (RefRelationship == Sema::Ref_Incompatible) { 3769 ConvOvlResult = TryRefInitWithConversionFunction(S, Entity, 3770 Kind, Initializer, 3771 /*AllowRValues=*/true, 3772 Sequence); 3773 if (ConvOvlResult) 3774 Sequence.SetOverloadFailure( 3775 InitializationSequence::FK_ReferenceInitOverloadFailed, 3776 ConvOvlResult); 3777 3778 return; 3779 } 3780 3781 if ((RefRelationship == Sema::Ref_Compatible || 3782 RefRelationship == Sema::Ref_Compatible_With_Added_Qualification) && 3783 isRValueRef && InitCategory.isLValue()) { 3784 Sequence.SetFailed( 3785 InitializationSequence::FK_RValueReferenceBindingToLValue); 3786 return; 3787 } 3788 3789 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers); 3790 return; 3791 } 3792 3793 // - Otherwise, a temporary of type "cv1 T1" is created and initialized 3794 // from the initializer expression using the rules for a non-reference 3795 // copy-initialization (8.5). The reference is then bound to the 3796 // temporary. [...] 3797 3798 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1); 3799 3800 // FIXME: Why do we use an implicit conversion here rather than trying 3801 // copy-initialization? 3802 ImplicitConversionSequence ICS 3803 = S.TryImplicitConversion(Initializer, TempEntity.getType(), 3804 /*SuppressUserConversions=*/false, 3805 /*AllowExplicit=*/false, 3806 /*FIXME:InOverloadResolution=*/false, 3807 /*CStyle=*/Kind.isCStyleOrFunctionalCast(), 3808 /*AllowObjCWritebackConversion=*/false); 3809 3810 if (ICS.isBad()) { 3811 // FIXME: Use the conversion function set stored in ICS to turn 3812 // this into an overloading ambiguity diagnostic. However, we need 3813 // to keep that set as an OverloadCandidateSet rather than as some 3814 // other kind of set. 3815 if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty()) 3816 Sequence.SetOverloadFailure( 3817 InitializationSequence::FK_ReferenceInitOverloadFailed, 3818 ConvOvlResult); 3819 else if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) 3820 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 3821 else 3822 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed); 3823 return; 3824 } else { 3825 Sequence.AddConversionSequenceStep(ICS, TempEntity.getType()); 3826 } 3827 3828 // [...] If T1 is reference-related to T2, cv1 must be the 3829 // same cv-qualification as, or greater cv-qualification 3830 // than, cv2; otherwise, the program is ill-formed. 3831 unsigned T1CVRQuals = T1Quals.getCVRQualifiers(); 3832 unsigned T2CVRQuals = T2Quals.getCVRQualifiers(); 3833 if (RefRelationship == Sema::Ref_Related && 3834 (T1CVRQuals | T2CVRQuals) != T1CVRQuals) { 3835 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers); 3836 return; 3837 } 3838 3839 // [...] If T1 is reference-related to T2 and the reference is an rvalue 3840 // reference, the initializer expression shall not be an lvalue. 3841 if (RefRelationship >= Sema::Ref_Related && !isLValueRef && 3842 InitCategory.isLValue()) { 3843 Sequence.SetFailed( 3844 InitializationSequence::FK_RValueReferenceBindingToLValue); 3845 return; 3846 } 3847 3848 Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true); 3849 return; 3850} 3851 3852/// \brief Attempt character array initialization from a string literal 3853/// (C++ [dcl.init.string], C99 6.7.8). 3854static void TryStringLiteralInitialization(Sema &S, 3855 const InitializedEntity &Entity, 3856 const InitializationKind &Kind, 3857 Expr *Initializer, 3858 InitializationSequence &Sequence) { 3859 Sequence.AddStringInitStep(Entity.getType()); 3860} 3861 3862/// \brief Attempt value initialization (C++ [dcl.init]p7). 3863static void TryValueInitialization(Sema &S, 3864 const InitializedEntity &Entity, 3865 const InitializationKind &Kind, 3866 InitializationSequence &Sequence, 3867 InitListExpr *InitList) { 3868 assert((!InitList || InitList->getNumInits() == 0) && 3869 "Shouldn't use value-init for non-empty init lists"); 3870 3871 // C++98 [dcl.init]p5, C++11 [dcl.init]p7: 3872 // 3873 // To value-initialize an object of type T means: 3874 QualType T = Entity.getType(); 3875 3876 // -- if T is an array type, then each element is value-initialized; 3877 T = S.Context.getBaseElementType(T); 3878 3879 if (const RecordType *RT = T->getAs<RecordType>()) { 3880 if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 3881 bool NeedZeroInitialization = true; 3882 if (!S.getLangOpts().CPlusPlus11) { 3883 // C++98: 3884 // -- if T is a class type (clause 9) with a user-declared constructor 3885 // (12.1), then the default constructor for T is called (and the 3886 // initialization is ill-formed if T has no accessible default 3887 // constructor); 3888 if (ClassDecl->hasUserDeclaredConstructor()) 3889 NeedZeroInitialization = false; 3890 } else { 3891 // C++11: 3892 // -- if T is a class type (clause 9) with either no default constructor 3893 // (12.1 [class.ctor]) or a default constructor that is user-provided 3894 // or deleted, then the object is default-initialized; 3895 CXXConstructorDecl *CD = S.LookupDefaultConstructor(ClassDecl); 3896 if (!CD || !CD->getCanonicalDecl()->isDefaulted() || CD->isDeleted()) 3897 NeedZeroInitialization = false; 3898 } 3899 3900 // -- if T is a (possibly cv-qualified) non-union class type without a 3901 // user-provided or deleted default constructor, then the object is 3902 // zero-initialized and, if T has a non-trivial default constructor, 3903 // default-initialized; 3904 // The 'non-union' here was removed by DR1502. The 'non-trivial default 3905 // constructor' part was removed by DR1507. 3906 if (NeedZeroInitialization) 3907 Sequence.AddZeroInitializationStep(Entity.getType()); 3908 3909 // C++03: 3910 // -- if T is a non-union class type without a user-declared constructor, 3911 // then every non-static data member and base class component of T is 3912 // value-initialized; 3913 // [...] A program that calls for [...] value-initialization of an 3914 // entity of reference type is ill-formed. 3915 // 3916 // C++11 doesn't need this handling, because value-initialization does not 3917 // occur recursively there, and the implicit default constructor is 3918 // defined as deleted in the problematic cases. 3919 if (!S.getLangOpts().CPlusPlus11 && 3920 ClassDecl->hasUninitializedReferenceMember()) { 3921 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForReference); 3922 return; 3923 } 3924 3925 // If this is list-value-initialization, pass the empty init list on when 3926 // building the constructor call. This affects the semantics of a few 3927 // things (such as whether an explicit default constructor can be called). 3928 Expr *InitListAsExpr = InitList; 3929 MultiExprArg Args(&InitListAsExpr, InitList ? 1 : 0); 3930 bool InitListSyntax = InitList; 3931 3932 return TryConstructorInitialization(S, Entity, Kind, Args, T, Sequence, 3933 InitListSyntax); 3934 } 3935 } 3936 3937 Sequence.AddZeroInitializationStep(Entity.getType()); 3938} 3939 3940/// \brief Attempt default initialization (C++ [dcl.init]p6). 3941static void TryDefaultInitialization(Sema &S, 3942 const InitializedEntity &Entity, 3943 const InitializationKind &Kind, 3944 InitializationSequence &Sequence) { 3945 assert(Kind.getKind() == InitializationKind::IK_Default); 3946 3947 // C++ [dcl.init]p6: 3948 // To default-initialize an object of type T means: 3949 // - if T is an array type, each element is default-initialized; 3950 QualType DestType = S.Context.getBaseElementType(Entity.getType()); 3951 3952 // - if T is a (possibly cv-qualified) class type (Clause 9), the default 3953 // constructor for T is called (and the initialization is ill-formed if 3954 // T has no accessible default constructor); 3955 if (DestType->isRecordType() && S.getLangOpts().CPlusPlus) { 3956 TryConstructorInitialization(S, Entity, Kind, None, DestType, Sequence); 3957 return; 3958 } 3959 3960 // - otherwise, no initialization is performed. 3961 3962 // If a program calls for the default initialization of an object of 3963 // a const-qualified type T, T shall be a class type with a user-provided 3964 // default constructor. 3965 if (DestType.isConstQualified() && S.getLangOpts().CPlusPlus) { 3966 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst); 3967 return; 3968 } 3969 3970 // If the destination type has a lifetime property, zero-initialize it. 3971 if (DestType.getQualifiers().hasObjCLifetime()) { 3972 Sequence.AddZeroInitializationStep(Entity.getType()); 3973 return; 3974 } 3975} 3976 3977/// \brief Attempt a user-defined conversion between two types (C++ [dcl.init]), 3978/// which enumerates all conversion functions and performs overload resolution 3979/// to select the best. 3980static void TryUserDefinedConversion(Sema &S, 3981 const InitializedEntity &Entity, 3982 const InitializationKind &Kind, 3983 Expr *Initializer, 3984 InitializationSequence &Sequence) { 3985 QualType DestType = Entity.getType(); 3986 assert(!DestType->isReferenceType() && "References are handled elsewhere"); 3987 QualType SourceType = Initializer->getType(); 3988 assert((DestType->isRecordType() || SourceType->isRecordType()) && 3989 "Must have a class type to perform a user-defined conversion"); 3990 3991 // Build the candidate set directly in the initialization sequence 3992 // structure, so that it will persist if we fail. 3993 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 3994 CandidateSet.clear(); 3995 3996 // Determine whether we are allowed to call explicit constructors or 3997 // explicit conversion operators. 3998 bool AllowExplicit = Kind.AllowExplicit(); 3999 4000 if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) { 4001 // The type we're converting to is a class type. Enumerate its constructors 4002 // to see if there is a suitable conversion. 4003 CXXRecordDecl *DestRecordDecl 4004 = cast<CXXRecordDecl>(DestRecordType->getDecl()); 4005 4006 // Try to complete the type we're converting to. 4007 if (!S.RequireCompleteType(Kind.getLocation(), DestType, 0)) { 4008 DeclContext::lookup_result R = S.LookupConstructors(DestRecordDecl); 4009 // The container holding the constructors can under certain conditions 4010 // be changed while iterating. To be safe we copy the lookup results 4011 // to a new container. 4012 SmallVector<NamedDecl*, 8> CopyOfCon(R.begin(), R.end()); 4013 for (SmallVector<NamedDecl*, 8>::iterator 4014 Con = CopyOfCon.begin(), ConEnd = CopyOfCon.end(); 4015 Con != ConEnd; ++Con) { 4016 NamedDecl *D = *Con; 4017 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 4018 4019 // Find the constructor (which may be a template). 4020 CXXConstructorDecl *Constructor = 0; 4021 FunctionTemplateDecl *ConstructorTmpl 4022 = dyn_cast<FunctionTemplateDecl>(D); 4023 if (ConstructorTmpl) 4024 Constructor = cast<CXXConstructorDecl>( 4025 ConstructorTmpl->getTemplatedDecl()); 4026 else 4027 Constructor = cast<CXXConstructorDecl>(D); 4028 4029 if (!Constructor->isInvalidDecl() && 4030 Constructor->isConvertingConstructor(AllowExplicit)) { 4031 if (ConstructorTmpl) 4032 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 4033 /*ExplicitArgs*/ 0, 4034 Initializer, CandidateSet, 4035 /*SuppressUserConversions=*/true); 4036 else 4037 S.AddOverloadCandidate(Constructor, FoundDecl, 4038 Initializer, CandidateSet, 4039 /*SuppressUserConversions=*/true); 4040 } 4041 } 4042 } 4043 } 4044 4045 SourceLocation DeclLoc = Initializer->getLocStart(); 4046 4047 if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) { 4048 // The type we're converting from is a class type, enumerate its conversion 4049 // functions. 4050 4051 // We can only enumerate the conversion functions for a complete type; if 4052 // the type isn't complete, simply skip this step. 4053 if (!S.RequireCompleteType(DeclLoc, SourceType, 0)) { 4054 CXXRecordDecl *SourceRecordDecl 4055 = cast<CXXRecordDecl>(SourceRecordType->getDecl()); 4056 4057 std::pair<CXXRecordDecl::conversion_iterator, 4058 CXXRecordDecl::conversion_iterator> 4059 Conversions = SourceRecordDecl->getVisibleConversionFunctions(); 4060 for (CXXRecordDecl::conversion_iterator 4061 I = Conversions.first, E = Conversions.second; I != E; ++I) { 4062 NamedDecl *D = *I; 4063 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 4064 if (isa<UsingShadowDecl>(D)) 4065 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4066 4067 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D); 4068 CXXConversionDecl *Conv; 4069 if (ConvTemplate) 4070 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 4071 else 4072 Conv = cast<CXXConversionDecl>(D); 4073 4074 if (AllowExplicit || !Conv->isExplicit()) { 4075 if (ConvTemplate) 4076 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), 4077 ActingDC, Initializer, DestType, 4078 CandidateSet); 4079 else 4080 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, 4081 Initializer, DestType, CandidateSet); 4082 } 4083 } 4084 } 4085 } 4086 4087 // Perform overload resolution. If it fails, return the failed result. 4088 OverloadCandidateSet::iterator Best; 4089 if (OverloadingResult Result 4090 = CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 4091 Sequence.SetOverloadFailure( 4092 InitializationSequence::FK_UserConversionOverloadFailed, 4093 Result); 4094 return; 4095 } 4096 4097 FunctionDecl *Function = Best->Function; 4098 Function->setReferenced(); 4099 bool HadMultipleCandidates = (CandidateSet.size() > 1); 4100 4101 if (isa<CXXConstructorDecl>(Function)) { 4102 // Add the user-defined conversion step. Any cv-qualification conversion is 4103 // subsumed by the initialization. Per DR5, the created temporary is of the 4104 // cv-unqualified type of the destination. 4105 Sequence.AddUserConversionStep(Function, Best->FoundDecl, 4106 DestType.getUnqualifiedType(), 4107 HadMultipleCandidates); 4108 return; 4109 } 4110 4111 // Add the user-defined conversion step that calls the conversion function. 4112 QualType ConvType = Function->getCallResultType(); 4113 if (ConvType->getAs<RecordType>()) { 4114 // If we're converting to a class type, there may be an copy of 4115 // the resulting temporary object (possible to create an object of 4116 // a base class type). That copy is not a separate conversion, so 4117 // we just make a note of the actual destination type (possibly a 4118 // base class of the type returned by the conversion function) and 4119 // let the user-defined conversion step handle the conversion. 4120 Sequence.AddUserConversionStep(Function, Best->FoundDecl, DestType, 4121 HadMultipleCandidates); 4122 return; 4123 } 4124 4125 Sequence.AddUserConversionStep(Function, Best->FoundDecl, ConvType, 4126 HadMultipleCandidates); 4127 4128 // If the conversion following the call to the conversion function 4129 // is interesting, add it as a separate step. 4130 if (Best->FinalConversion.First || Best->FinalConversion.Second || 4131 Best->FinalConversion.Third) { 4132 ImplicitConversionSequence ICS; 4133 ICS.setStandard(); 4134 ICS.Standard = Best->FinalConversion; 4135 Sequence.AddConversionSequenceStep(ICS, DestType); 4136 } 4137} 4138 4139/// The non-zero enum values here are indexes into diagnostic alternatives. 4140enum InvalidICRKind { IIK_okay, IIK_nonlocal, IIK_nonscalar }; 4141 4142/// Determines whether this expression is an acceptable ICR source. 4143static InvalidICRKind isInvalidICRSource(ASTContext &C, Expr *e, 4144 bool isAddressOf, bool &isWeakAccess) { 4145 // Skip parens. 4146 e = e->IgnoreParens(); 4147 4148 // Skip address-of nodes. 4149 if (UnaryOperator *op = dyn_cast<UnaryOperator>(e)) { 4150 if (op->getOpcode() == UO_AddrOf) 4151 return isInvalidICRSource(C, op->getSubExpr(), /*addressof*/ true, 4152 isWeakAccess); 4153 4154 // Skip certain casts. 4155 } else if (CastExpr *ce = dyn_cast<CastExpr>(e)) { 4156 switch (ce->getCastKind()) { 4157 case CK_Dependent: 4158 case CK_BitCast: 4159 case CK_LValueBitCast: 4160 case CK_NoOp: 4161 return isInvalidICRSource(C, ce->getSubExpr(), isAddressOf, isWeakAccess); 4162 4163 case CK_ArrayToPointerDecay: 4164 return IIK_nonscalar; 4165 4166 case CK_NullToPointer: 4167 return IIK_okay; 4168 4169 default: 4170 break; 4171 } 4172 4173 // If we have a declaration reference, it had better be a local variable. 4174 } else if (isa<DeclRefExpr>(e)) { 4175 // set isWeakAccess to true, to mean that there will be an implicit 4176 // load which requires a cleanup. 4177 if (e->getType().getObjCLifetime() == Qualifiers::OCL_Weak) 4178 isWeakAccess = true; 4179 4180 if (!isAddressOf) return IIK_nonlocal; 4181 4182 VarDecl *var = dyn_cast<VarDecl>(cast<DeclRefExpr>(e)->getDecl()); 4183 if (!var) return IIK_nonlocal; 4184 4185 return (var->hasLocalStorage() ? IIK_okay : IIK_nonlocal); 4186 4187 // If we have a conditional operator, check both sides. 4188 } else if (ConditionalOperator *cond = dyn_cast<ConditionalOperator>(e)) { 4189 if (InvalidICRKind iik = isInvalidICRSource(C, cond->getLHS(), isAddressOf, 4190 isWeakAccess)) 4191 return iik; 4192 4193 return isInvalidICRSource(C, cond->getRHS(), isAddressOf, isWeakAccess); 4194 4195 // These are never scalar. 4196 } else if (isa<ArraySubscriptExpr>(e)) { 4197 return IIK_nonscalar; 4198 4199 // Otherwise, it needs to be a null pointer constant. 4200 } else { 4201 return (e->isNullPointerConstant(C, Expr::NPC_ValueDependentIsNull) 4202 ? IIK_okay : IIK_nonlocal); 4203 } 4204 4205 return IIK_nonlocal; 4206} 4207 4208/// Check whether the given expression is a valid operand for an 4209/// indirect copy/restore. 4210static void checkIndirectCopyRestoreSource(Sema &S, Expr *src) { 4211 assert(src->isRValue()); 4212 bool isWeakAccess = false; 4213 InvalidICRKind iik = isInvalidICRSource(S.Context, src, false, isWeakAccess); 4214 // If isWeakAccess to true, there will be an implicit 4215 // load which requires a cleanup. 4216 if (S.getLangOpts().ObjCAutoRefCount && isWeakAccess) 4217 S.ExprNeedsCleanups = true; 4218 4219 if (iik == IIK_okay) return; 4220 4221 S.Diag(src->getExprLoc(), diag::err_arc_nonlocal_writeback) 4222 << ((unsigned) iik - 1) // shift index into diagnostic explanations 4223 << src->getSourceRange(); 4224} 4225 4226/// \brief Determine whether we have compatible array types for the 4227/// purposes of GNU by-copy array initialization. 4228static bool hasCompatibleArrayTypes(ASTContext &Context, 4229 const ArrayType *Dest, 4230 const ArrayType *Source) { 4231 // If the source and destination array types are equivalent, we're 4232 // done. 4233 if (Context.hasSameType(QualType(Dest, 0), QualType(Source, 0))) 4234 return true; 4235 4236 // Make sure that the element types are the same. 4237 if (!Context.hasSameType(Dest->getElementType(), Source->getElementType())) 4238 return false; 4239 4240 // The only mismatch we allow is when the destination is an 4241 // incomplete array type and the source is a constant array type. 4242 return Source->isConstantArrayType() && Dest->isIncompleteArrayType(); 4243} 4244 4245static bool tryObjCWritebackConversion(Sema &S, 4246 InitializationSequence &Sequence, 4247 const InitializedEntity &Entity, 4248 Expr *Initializer) { 4249 bool ArrayDecay = false; 4250 QualType ArgType = Initializer->getType(); 4251 QualType ArgPointee; 4252 if (const ArrayType *ArgArrayType = S.Context.getAsArrayType(ArgType)) { 4253 ArrayDecay = true; 4254 ArgPointee = ArgArrayType->getElementType(); 4255 ArgType = S.Context.getPointerType(ArgPointee); 4256 } 4257 4258 // Handle write-back conversion. 4259 QualType ConvertedArgType; 4260 if (!S.isObjCWritebackConversion(ArgType, Entity.getType(), 4261 ConvertedArgType)) 4262 return false; 4263 4264 // We should copy unless we're passing to an argument explicitly 4265 // marked 'out'. 4266 bool ShouldCopy = true; 4267 if (ParmVarDecl *param = cast_or_null<ParmVarDecl>(Entity.getDecl())) 4268 ShouldCopy = (param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out); 4269 4270 // Do we need an lvalue conversion? 4271 if (ArrayDecay || Initializer->isGLValue()) { 4272 ImplicitConversionSequence ICS; 4273 ICS.setStandard(); 4274 ICS.Standard.setAsIdentityConversion(); 4275 4276 QualType ResultType; 4277 if (ArrayDecay) { 4278 ICS.Standard.First = ICK_Array_To_Pointer; 4279 ResultType = S.Context.getPointerType(ArgPointee); 4280 } else { 4281 ICS.Standard.First = ICK_Lvalue_To_Rvalue; 4282 ResultType = Initializer->getType().getNonLValueExprType(S.Context); 4283 } 4284 4285 Sequence.AddConversionSequenceStep(ICS, ResultType); 4286 } 4287 4288 Sequence.AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy); 4289 return true; 4290} 4291 4292static bool TryOCLSamplerInitialization(Sema &S, 4293 InitializationSequence &Sequence, 4294 QualType DestType, 4295 Expr *Initializer) { 4296 if (!S.getLangOpts().OpenCL || !DestType->isSamplerT() || 4297 !Initializer->isIntegerConstantExpr(S.getASTContext())) 4298 return false; 4299 4300 Sequence.AddOCLSamplerInitStep(DestType); 4301 return true; 4302} 4303 4304// 4305// OpenCL 1.2 spec, s6.12.10 4306// 4307// The event argument can also be used to associate the 4308// async_work_group_copy with a previous async copy allowing 4309// an event to be shared by multiple async copies; otherwise 4310// event should be zero. 4311// 4312static bool TryOCLZeroEventInitialization(Sema &S, 4313 InitializationSequence &Sequence, 4314 QualType DestType, 4315 Expr *Initializer) { 4316 if (!S.getLangOpts().OpenCL || !DestType->isEventT() || 4317 !Initializer->isIntegerConstantExpr(S.getASTContext()) || 4318 (Initializer->EvaluateKnownConstInt(S.getASTContext()) != 0)) 4319 return false; 4320 4321 Sequence.AddOCLZeroEventStep(DestType); 4322 return true; 4323} 4324 4325InitializationSequence::InitializationSequence(Sema &S, 4326 const InitializedEntity &Entity, 4327 const InitializationKind &Kind, 4328 MultiExprArg Args) 4329 : FailedCandidateSet(Kind.getLocation()) { 4330 ASTContext &Context = S.Context; 4331 4332 // Eliminate non-overload placeholder types in the arguments. We 4333 // need to do this before checking whether types are dependent 4334 // because lowering a pseudo-object expression might well give us 4335 // something of dependent type. 4336 for (unsigned I = 0, E = Args.size(); I != E; ++I) 4337 if (Args[I]->getType()->isNonOverloadPlaceholderType()) { 4338 // FIXME: should we be doing this here? 4339 ExprResult result = S.CheckPlaceholderExpr(Args[I]); 4340 if (result.isInvalid()) { 4341 SetFailed(FK_PlaceholderType); 4342 return; 4343 } 4344 Args[I] = result.take(); 4345 } 4346 4347 // C++0x [dcl.init]p16: 4348 // The semantics of initializers are as follows. The destination type is 4349 // the type of the object or reference being initialized and the source 4350 // type is the type of the initializer expression. The source type is not 4351 // defined when the initializer is a braced-init-list or when it is a 4352 // parenthesized list of expressions. 4353 QualType DestType = Entity.getType(); 4354 4355 if (DestType->isDependentType() || 4356 Expr::hasAnyTypeDependentArguments(Args)) { 4357 SequenceKind = DependentSequence; 4358 return; 4359 } 4360 4361 // Almost everything is a normal sequence. 4362 setSequenceKind(NormalSequence); 4363 4364 QualType SourceType; 4365 Expr *Initializer = 0; 4366 if (Args.size() == 1) { 4367 Initializer = Args[0]; 4368 if (!isa<InitListExpr>(Initializer)) 4369 SourceType = Initializer->getType(); 4370 } 4371 4372 // - If the initializer is a (non-parenthesized) braced-init-list, the 4373 // object is list-initialized (8.5.4). 4374 if (Kind.getKind() != InitializationKind::IK_Direct) { 4375 if (InitListExpr *InitList = dyn_cast_or_null<InitListExpr>(Initializer)) { 4376 TryListInitialization(S, Entity, Kind, InitList, *this); 4377 return; 4378 } 4379 } 4380 4381 // - If the destination type is a reference type, see 8.5.3. 4382 if (DestType->isReferenceType()) { 4383 // C++0x [dcl.init.ref]p1: 4384 // A variable declared to be a T& or T&&, that is, "reference to type T" 4385 // (8.3.2), shall be initialized by an object, or function, of type T or 4386 // by an object that can be converted into a T. 4387 // (Therefore, multiple arguments are not permitted.) 4388 if (Args.size() != 1) 4389 SetFailed(FK_TooManyInitsForReference); 4390 else 4391 TryReferenceInitialization(S, Entity, Kind, Args[0], *this); 4392 return; 4393 } 4394 4395 // - If the initializer is (), the object is value-initialized. 4396 if (Kind.getKind() == InitializationKind::IK_Value || 4397 (Kind.getKind() == InitializationKind::IK_Direct && Args.empty())) { 4398 TryValueInitialization(S, Entity, Kind, *this); 4399 return; 4400 } 4401 4402 // Handle default initialization. 4403 if (Kind.getKind() == InitializationKind::IK_Default) { 4404 TryDefaultInitialization(S, Entity, Kind, *this); 4405 return; 4406 } 4407 4408 // - If the destination type is an array of characters, an array of 4409 // char16_t, an array of char32_t, or an array of wchar_t, and the 4410 // initializer is a string literal, see 8.5.2. 4411 // - Otherwise, if the destination type is an array, the program is 4412 // ill-formed. 4413 if (const ArrayType *DestAT = Context.getAsArrayType(DestType)) { 4414 if (Initializer && isa<VariableArrayType>(DestAT)) { 4415 SetFailed(FK_VariableLengthArrayHasInitializer); 4416 return; 4417 } 4418 4419 if (Initializer) { 4420 switch (IsStringInit(Initializer, DestAT, Context)) { 4421 case SIF_None: 4422 TryStringLiteralInitialization(S, Entity, Kind, Initializer, *this); 4423 return; 4424 case SIF_NarrowStringIntoWideChar: 4425 SetFailed(FK_NarrowStringIntoWideCharArray); 4426 return; 4427 case SIF_WideStringIntoChar: 4428 SetFailed(FK_WideStringIntoCharArray); 4429 return; 4430 case SIF_IncompatWideStringIntoWideChar: 4431 SetFailed(FK_IncompatWideStringIntoWideChar); 4432 return; 4433 case SIF_Other: 4434 break; 4435 } 4436 } 4437 4438 // Note: as an GNU C extension, we allow initialization of an 4439 // array from a compound literal that creates an array of the same 4440 // type, so long as the initializer has no side effects. 4441 if (!S.getLangOpts().CPlusPlus && Initializer && 4442 isa<CompoundLiteralExpr>(Initializer->IgnoreParens()) && 4443 Initializer->getType()->isArrayType()) { 4444 const ArrayType *SourceAT 4445 = Context.getAsArrayType(Initializer->getType()); 4446 if (!hasCompatibleArrayTypes(S.Context, DestAT, SourceAT)) 4447 SetFailed(FK_ArrayTypeMismatch); 4448 else if (Initializer->HasSideEffects(S.Context)) 4449 SetFailed(FK_NonConstantArrayInit); 4450 else { 4451 AddArrayInitStep(DestType); 4452 } 4453 } 4454 // Note: as a GNU C++ extension, we allow list-initialization of a 4455 // class member of array type from a parenthesized initializer list. 4456 else if (S.getLangOpts().CPlusPlus && 4457 Entity.getKind() == InitializedEntity::EK_Member && 4458 Initializer && isa<InitListExpr>(Initializer)) { 4459 TryListInitialization(S, Entity, Kind, cast<InitListExpr>(Initializer), 4460 *this); 4461 AddParenthesizedArrayInitStep(DestType); 4462 } else if (DestAT->getElementType()->isCharType()) 4463 SetFailed(FK_ArrayNeedsInitListOrStringLiteral); 4464 else if (IsWideCharCompatible(DestAT->getElementType(), Context)) 4465 SetFailed(FK_ArrayNeedsInitListOrWideStringLiteral); 4466 else 4467 SetFailed(FK_ArrayNeedsInitList); 4468 4469 return; 4470 } 4471 4472 // Determine whether we should consider writeback conversions for 4473 // Objective-C ARC. 4474 bool allowObjCWritebackConversion = S.getLangOpts().ObjCAutoRefCount && 4475 Entity.getKind() == InitializedEntity::EK_Parameter; 4476 4477 // We're at the end of the line for C: it's either a write-back conversion 4478 // or it's a C assignment. There's no need to check anything else. 4479 if (!S.getLangOpts().CPlusPlus) { 4480 // If allowed, check whether this is an Objective-C writeback conversion. 4481 if (allowObjCWritebackConversion && 4482 tryObjCWritebackConversion(S, *this, Entity, Initializer)) { 4483 return; 4484 } 4485 4486 if (TryOCLSamplerInitialization(S, *this, DestType, Initializer)) 4487 return; 4488 4489 if (TryOCLZeroEventInitialization(S, *this, DestType, Initializer)) 4490 return; 4491 4492 // Handle initialization in C 4493 AddCAssignmentStep(DestType); 4494 MaybeProduceObjCObject(S, *this, Entity); 4495 return; 4496 } 4497 4498 assert(S.getLangOpts().CPlusPlus); 4499 4500 // - If the destination type is a (possibly cv-qualified) class type: 4501 if (DestType->isRecordType()) { 4502 // - If the initialization is direct-initialization, or if it is 4503 // copy-initialization where the cv-unqualified version of the 4504 // source type is the same class as, or a derived class of, the 4505 // class of the destination, constructors are considered. [...] 4506 if (Kind.getKind() == InitializationKind::IK_Direct || 4507 (Kind.getKind() == InitializationKind::IK_Copy && 4508 (Context.hasSameUnqualifiedType(SourceType, DestType) || 4509 S.IsDerivedFrom(SourceType, DestType)))) 4510 TryConstructorInitialization(S, Entity, Kind, Args, 4511 Entity.getType(), *this); 4512 // - Otherwise (i.e., for the remaining copy-initialization cases), 4513 // user-defined conversion sequences that can convert from the source 4514 // type to the destination type or (when a conversion function is 4515 // used) to a derived class thereof are enumerated as described in 4516 // 13.3.1.4, and the best one is chosen through overload resolution 4517 // (13.3). 4518 else 4519 TryUserDefinedConversion(S, Entity, Kind, Initializer, *this); 4520 return; 4521 } 4522 4523 if (Args.size() > 1) { 4524 SetFailed(FK_TooManyInitsForScalar); 4525 return; 4526 } 4527 assert(Args.size() == 1 && "Zero-argument case handled above"); 4528 4529 // - Otherwise, if the source type is a (possibly cv-qualified) class 4530 // type, conversion functions are considered. 4531 if (!SourceType.isNull() && SourceType->isRecordType()) { 4532 TryUserDefinedConversion(S, Entity, Kind, Initializer, *this); 4533 MaybeProduceObjCObject(S, *this, Entity); 4534 return; 4535 } 4536 4537 // - Otherwise, the initial value of the object being initialized is the 4538 // (possibly converted) value of the initializer expression. Standard 4539 // conversions (Clause 4) will be used, if necessary, to convert the 4540 // initializer expression to the cv-unqualified version of the 4541 // destination type; no user-defined conversions are considered. 4542 4543 ImplicitConversionSequence ICS 4544 = S.TryImplicitConversion(Initializer, Entity.getType(), 4545 /*SuppressUserConversions*/true, 4546 /*AllowExplicitConversions*/ false, 4547 /*InOverloadResolution*/ false, 4548 /*CStyle=*/Kind.isCStyleOrFunctionalCast(), 4549 allowObjCWritebackConversion); 4550 4551 if (ICS.isStandard() && 4552 ICS.Standard.Second == ICK_Writeback_Conversion) { 4553 // Objective-C ARC writeback conversion. 4554 4555 // We should copy unless we're passing to an argument explicitly 4556 // marked 'out'. 4557 bool ShouldCopy = true; 4558 if (ParmVarDecl *Param = cast_or_null<ParmVarDecl>(Entity.getDecl())) 4559 ShouldCopy = (Param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out); 4560 4561 // If there was an lvalue adjustment, add it as a separate conversion. 4562 if (ICS.Standard.First == ICK_Array_To_Pointer || 4563 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 4564 ImplicitConversionSequence LvalueICS; 4565 LvalueICS.setStandard(); 4566 LvalueICS.Standard.setAsIdentityConversion(); 4567 LvalueICS.Standard.setAllToTypes(ICS.Standard.getToType(0)); 4568 LvalueICS.Standard.First = ICS.Standard.First; 4569 AddConversionSequenceStep(LvalueICS, ICS.Standard.getToType(0)); 4570 } 4571 4572 AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy); 4573 } else if (ICS.isBad()) { 4574 DeclAccessPair dap; 4575 if (Initializer->getType() == Context.OverloadTy && 4576 !S.ResolveAddressOfOverloadedFunction(Initializer 4577 , DestType, false, dap)) 4578 SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 4579 else 4580 SetFailed(InitializationSequence::FK_ConversionFailed); 4581 } else { 4582 AddConversionSequenceStep(ICS, Entity.getType()); 4583 4584 MaybeProduceObjCObject(S, *this, Entity); 4585 } 4586} 4587 4588InitializationSequence::~InitializationSequence() { 4589 for (SmallVectorImpl<Step>::iterator Step = Steps.begin(), 4590 StepEnd = Steps.end(); 4591 Step != StepEnd; ++Step) 4592 Step->Destroy(); 4593} 4594 4595//===----------------------------------------------------------------------===// 4596// Perform initialization 4597//===----------------------------------------------------------------------===// 4598static Sema::AssignmentAction 4599getAssignmentAction(const InitializedEntity &Entity) { 4600 switch(Entity.getKind()) { 4601 case InitializedEntity::EK_Variable: 4602 case InitializedEntity::EK_New: 4603 case InitializedEntity::EK_Exception: 4604 case InitializedEntity::EK_Base: 4605 case InitializedEntity::EK_Delegating: 4606 return Sema::AA_Initializing; 4607 4608 case InitializedEntity::EK_Parameter: 4609 if (Entity.getDecl() && 4610 isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext())) 4611 return Sema::AA_Sending; 4612 4613 return Sema::AA_Passing; 4614 4615 case InitializedEntity::EK_Result: 4616 return Sema::AA_Returning; 4617 4618 case InitializedEntity::EK_Temporary: 4619 // FIXME: Can we tell apart casting vs. converting? 4620 return Sema::AA_Casting; 4621 4622 case InitializedEntity::EK_Member: 4623 case InitializedEntity::EK_ArrayElement: 4624 case InitializedEntity::EK_VectorElement: 4625 case InitializedEntity::EK_ComplexElement: 4626 case InitializedEntity::EK_BlockElement: 4627 case InitializedEntity::EK_LambdaCapture: 4628 case InitializedEntity::EK_CompoundLiteralInit: 4629 return Sema::AA_Initializing; 4630 } 4631 4632 llvm_unreachable("Invalid EntityKind!"); 4633} 4634 4635/// \brief Whether we should bind a created object as a temporary when 4636/// initializing the given entity. 4637static bool shouldBindAsTemporary(const InitializedEntity &Entity) { 4638 switch (Entity.getKind()) { 4639 case InitializedEntity::EK_ArrayElement: 4640 case InitializedEntity::EK_Member: 4641 case InitializedEntity::EK_Result: 4642 case InitializedEntity::EK_New: 4643 case InitializedEntity::EK_Variable: 4644 case InitializedEntity::EK_Base: 4645 case InitializedEntity::EK_Delegating: 4646 case InitializedEntity::EK_VectorElement: 4647 case InitializedEntity::EK_ComplexElement: 4648 case InitializedEntity::EK_Exception: 4649 case InitializedEntity::EK_BlockElement: 4650 case InitializedEntity::EK_LambdaCapture: 4651 case InitializedEntity::EK_CompoundLiteralInit: 4652 return false; 4653 4654 case InitializedEntity::EK_Parameter: 4655 case InitializedEntity::EK_Temporary: 4656 return true; 4657 } 4658 4659 llvm_unreachable("missed an InitializedEntity kind?"); 4660} 4661 4662/// \brief Whether the given entity, when initialized with an object 4663/// created for that initialization, requires destruction. 4664static bool shouldDestroyTemporary(const InitializedEntity &Entity) { 4665 switch (Entity.getKind()) { 4666 case InitializedEntity::EK_Result: 4667 case InitializedEntity::EK_New: 4668 case InitializedEntity::EK_Base: 4669 case InitializedEntity::EK_Delegating: 4670 case InitializedEntity::EK_VectorElement: 4671 case InitializedEntity::EK_ComplexElement: 4672 case InitializedEntity::EK_BlockElement: 4673 case InitializedEntity::EK_LambdaCapture: 4674 return false; 4675 4676 case InitializedEntity::EK_Member: 4677 case InitializedEntity::EK_Variable: 4678 case InitializedEntity::EK_Parameter: 4679 case InitializedEntity::EK_Temporary: 4680 case InitializedEntity::EK_ArrayElement: 4681 case InitializedEntity::EK_Exception: 4682 case InitializedEntity::EK_CompoundLiteralInit: 4683 return true; 4684 } 4685 4686 llvm_unreachable("missed an InitializedEntity kind?"); 4687} 4688 4689/// \brief Look for copy and move constructors and constructor templates, for 4690/// copying an object via direct-initialization (per C++11 [dcl.init]p16). 4691static void LookupCopyAndMoveConstructors(Sema &S, 4692 OverloadCandidateSet &CandidateSet, 4693 CXXRecordDecl *Class, 4694 Expr *CurInitExpr) { 4695 DeclContext::lookup_result R = S.LookupConstructors(Class); 4696 // The container holding the constructors can under certain conditions 4697 // be changed while iterating (e.g. because of deserialization). 4698 // To be safe we copy the lookup results to a new container. 4699 SmallVector<NamedDecl*, 16> Ctors(R.begin(), R.end()); 4700 for (SmallVector<NamedDecl*, 16>::iterator 4701 CI = Ctors.begin(), CE = Ctors.end(); CI != CE; ++CI) { 4702 NamedDecl *D = *CI; 4703 CXXConstructorDecl *Constructor = 0; 4704 4705 if ((Constructor = dyn_cast<CXXConstructorDecl>(D))) { 4706 // Handle copy/moveconstructors, only. 4707 if (!Constructor || Constructor->isInvalidDecl() || 4708 !Constructor->isCopyOrMoveConstructor() || 4709 !Constructor->isConvertingConstructor(/*AllowExplicit=*/true)) 4710 continue; 4711 4712 DeclAccessPair FoundDecl 4713 = DeclAccessPair::make(Constructor, Constructor->getAccess()); 4714 S.AddOverloadCandidate(Constructor, FoundDecl, 4715 CurInitExpr, CandidateSet); 4716 continue; 4717 } 4718 4719 // Handle constructor templates. 4720 FunctionTemplateDecl *ConstructorTmpl = cast<FunctionTemplateDecl>(D); 4721 if (ConstructorTmpl->isInvalidDecl()) 4722 continue; 4723 4724 Constructor = cast<CXXConstructorDecl>( 4725 ConstructorTmpl->getTemplatedDecl()); 4726 if (!Constructor->isConvertingConstructor(/*AllowExplicit=*/true)) 4727 continue; 4728 4729 // FIXME: Do we need to limit this to copy-constructor-like 4730 // candidates? 4731 DeclAccessPair FoundDecl 4732 = DeclAccessPair::make(ConstructorTmpl, ConstructorTmpl->getAccess()); 4733 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 0, 4734 CurInitExpr, CandidateSet, true); 4735 } 4736} 4737 4738/// \brief Get the location at which initialization diagnostics should appear. 4739static SourceLocation getInitializationLoc(const InitializedEntity &Entity, 4740 Expr *Initializer) { 4741 switch (Entity.getKind()) { 4742 case InitializedEntity::EK_Result: 4743 return Entity.getReturnLoc(); 4744 4745 case InitializedEntity::EK_Exception: 4746 return Entity.getThrowLoc(); 4747 4748 case InitializedEntity::EK_Variable: 4749 return Entity.getDecl()->getLocation(); 4750 4751 case InitializedEntity::EK_LambdaCapture: 4752 return Entity.getCaptureLoc(); 4753 4754 case InitializedEntity::EK_ArrayElement: 4755 case InitializedEntity::EK_Member: 4756 case InitializedEntity::EK_Parameter: 4757 case InitializedEntity::EK_Temporary: 4758 case InitializedEntity::EK_New: 4759 case InitializedEntity::EK_Base: 4760 case InitializedEntity::EK_Delegating: 4761 case InitializedEntity::EK_VectorElement: 4762 case InitializedEntity::EK_ComplexElement: 4763 case InitializedEntity::EK_BlockElement: 4764 case InitializedEntity::EK_CompoundLiteralInit: 4765 return Initializer->getLocStart(); 4766 } 4767 llvm_unreachable("missed an InitializedEntity kind?"); 4768} 4769 4770/// \brief Make a (potentially elidable) temporary copy of the object 4771/// provided by the given initializer by calling the appropriate copy 4772/// constructor. 4773/// 4774/// \param S The Sema object used for type-checking. 4775/// 4776/// \param T The type of the temporary object, which must either be 4777/// the type of the initializer expression or a superclass thereof. 4778/// 4779/// \param Entity The entity being initialized. 4780/// 4781/// \param CurInit The initializer expression. 4782/// 4783/// \param IsExtraneousCopy Whether this is an "extraneous" copy that 4784/// is permitted in C++03 (but not C++0x) when binding a reference to 4785/// an rvalue. 4786/// 4787/// \returns An expression that copies the initializer expression into 4788/// a temporary object, or an error expression if a copy could not be 4789/// created. 4790static ExprResult CopyObject(Sema &S, 4791 QualType T, 4792 const InitializedEntity &Entity, 4793 ExprResult CurInit, 4794 bool IsExtraneousCopy) { 4795 // Determine which class type we're copying to. 4796 Expr *CurInitExpr = (Expr *)CurInit.get(); 4797 CXXRecordDecl *Class = 0; 4798 if (const RecordType *Record = T->getAs<RecordType>()) 4799 Class = cast<CXXRecordDecl>(Record->getDecl()); 4800 if (!Class) 4801 return CurInit; 4802 4803 // C++0x [class.copy]p32: 4804 // When certain criteria are met, an implementation is allowed to 4805 // omit the copy/move construction of a class object, even if the 4806 // copy/move constructor and/or destructor for the object have 4807 // side effects. [...] 4808 // - when a temporary class object that has not been bound to a 4809 // reference (12.2) would be copied/moved to a class object 4810 // with the same cv-unqualified type, the copy/move operation 4811 // can be omitted by constructing the temporary object 4812 // directly into the target of the omitted copy/move 4813 // 4814 // Note that the other three bullets are handled elsewhere. Copy 4815 // elision for return statements and throw expressions are handled as part 4816 // of constructor initialization, while copy elision for exception handlers 4817 // is handled by the run-time. 4818 bool Elidable = CurInitExpr->isTemporaryObject(S.Context, Class); 4819 SourceLocation Loc = getInitializationLoc(Entity, CurInit.get()); 4820 4821 // Make sure that the type we are copying is complete. 4822 if (S.RequireCompleteType(Loc, T, diag::err_temp_copy_incomplete)) 4823 return CurInit; 4824 4825 // Perform overload resolution using the class's copy/move constructors. 4826 // Only consider constructors and constructor templates. Per 4827 // C++0x [dcl.init]p16, second bullet to class types, this initialization 4828 // is direct-initialization. 4829 OverloadCandidateSet CandidateSet(Loc); 4830 LookupCopyAndMoveConstructors(S, CandidateSet, Class, CurInitExpr); 4831 4832 bool HadMultipleCandidates = (CandidateSet.size() > 1); 4833 4834 OverloadCandidateSet::iterator Best; 4835 switch (CandidateSet.BestViableFunction(S, Loc, Best)) { 4836 case OR_Success: 4837 break; 4838 4839 case OR_No_Viable_Function: 4840 S.Diag(Loc, IsExtraneousCopy && !S.isSFINAEContext() 4841 ? diag::ext_rvalue_to_reference_temp_copy_no_viable 4842 : diag::err_temp_copy_no_viable) 4843 << (int)Entity.getKind() << CurInitExpr->getType() 4844 << CurInitExpr->getSourceRange(); 4845 CandidateSet.NoteCandidates(S, OCD_AllCandidates, CurInitExpr); 4846 if (!IsExtraneousCopy || S.isSFINAEContext()) 4847 return ExprError(); 4848 return CurInit; 4849 4850 case OR_Ambiguous: 4851 S.Diag(Loc, diag::err_temp_copy_ambiguous) 4852 << (int)Entity.getKind() << CurInitExpr->getType() 4853 << CurInitExpr->getSourceRange(); 4854 CandidateSet.NoteCandidates(S, OCD_ViableCandidates, CurInitExpr); 4855 return ExprError(); 4856 4857 case OR_Deleted: 4858 S.Diag(Loc, diag::err_temp_copy_deleted) 4859 << (int)Entity.getKind() << CurInitExpr->getType() 4860 << CurInitExpr->getSourceRange(); 4861 S.NoteDeletedFunction(Best->Function); 4862 return ExprError(); 4863 } 4864 4865 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function); 4866 SmallVector<Expr*, 8> ConstructorArgs; 4867 CurInit.release(); // Ownership transferred into MultiExprArg, below. 4868 4869 S.CheckConstructorAccess(Loc, Constructor, Entity, 4870 Best->FoundDecl.getAccess(), IsExtraneousCopy); 4871 4872 if (IsExtraneousCopy) { 4873 // If this is a totally extraneous copy for C++03 reference 4874 // binding purposes, just return the original initialization 4875 // expression. We don't generate an (elided) copy operation here 4876 // because doing so would require us to pass down a flag to avoid 4877 // infinite recursion, where each step adds another extraneous, 4878 // elidable copy. 4879 4880 // Instantiate the default arguments of any extra parameters in 4881 // the selected copy constructor, as if we were going to create a 4882 // proper call to the copy constructor. 4883 for (unsigned I = 1, N = Constructor->getNumParams(); I != N; ++I) { 4884 ParmVarDecl *Parm = Constructor->getParamDecl(I); 4885 if (S.RequireCompleteType(Loc, Parm->getType(), 4886 diag::err_call_incomplete_argument)) 4887 break; 4888 4889 // Build the default argument expression; we don't actually care 4890 // if this succeeds or not, because this routine will complain 4891 // if there was a problem. 4892 S.BuildCXXDefaultArgExpr(Loc, Constructor, Parm); 4893 } 4894 4895 return S.Owned(CurInitExpr); 4896 } 4897 4898 // Determine the arguments required to actually perform the 4899 // constructor call (we might have derived-to-base conversions, or 4900 // the copy constructor may have default arguments). 4901 if (S.CompleteConstructorCall(Constructor, CurInitExpr, Loc, ConstructorArgs)) 4902 return ExprError(); 4903 4904 // Actually perform the constructor call. 4905 CurInit = S.BuildCXXConstructExpr(Loc, T, Constructor, Elidable, 4906 ConstructorArgs, 4907 HadMultipleCandidates, 4908 /*ListInit*/ false, 4909 /*ZeroInit*/ false, 4910 CXXConstructExpr::CK_Complete, 4911 SourceRange()); 4912 4913 // If we're supposed to bind temporaries, do so. 4914 if (!CurInit.isInvalid() && shouldBindAsTemporary(Entity)) 4915 CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>()); 4916 return CurInit; 4917} 4918 4919/// \brief Check whether elidable copy construction for binding a reference to 4920/// a temporary would have succeeded if we were building in C++98 mode, for 4921/// -Wc++98-compat. 4922static void CheckCXX98CompatAccessibleCopy(Sema &S, 4923 const InitializedEntity &Entity, 4924 Expr *CurInitExpr) { 4925 assert(S.getLangOpts().CPlusPlus11); 4926 4927 const RecordType *Record = CurInitExpr->getType()->getAs<RecordType>(); 4928 if (!Record) 4929 return; 4930 4931 SourceLocation Loc = getInitializationLoc(Entity, CurInitExpr); 4932 if (S.Diags.getDiagnosticLevel(diag::warn_cxx98_compat_temp_copy, Loc) 4933 == DiagnosticsEngine::Ignored) 4934 return; 4935 4936 // Find constructors which would have been considered. 4937 OverloadCandidateSet CandidateSet(Loc); 4938 LookupCopyAndMoveConstructors( 4939 S, CandidateSet, cast<CXXRecordDecl>(Record->getDecl()), CurInitExpr); 4940 4941 // Perform overload resolution. 4942 OverloadCandidateSet::iterator Best; 4943 OverloadingResult OR = CandidateSet.BestViableFunction(S, Loc, Best); 4944 4945 PartialDiagnostic Diag = S.PDiag(diag::warn_cxx98_compat_temp_copy) 4946 << OR << (int)Entity.getKind() << CurInitExpr->getType() 4947 << CurInitExpr->getSourceRange(); 4948 4949 switch (OR) { 4950 case OR_Success: 4951 S.CheckConstructorAccess(Loc, cast<CXXConstructorDecl>(Best->Function), 4952 Entity, Best->FoundDecl.getAccess(), Diag); 4953 // FIXME: Check default arguments as far as that's possible. 4954 break; 4955 4956 case OR_No_Viable_Function: 4957 S.Diag(Loc, Diag); 4958 CandidateSet.NoteCandidates(S, OCD_AllCandidates, CurInitExpr); 4959 break; 4960 4961 case OR_Ambiguous: 4962 S.Diag(Loc, Diag); 4963 CandidateSet.NoteCandidates(S, OCD_ViableCandidates, CurInitExpr); 4964 break; 4965 4966 case OR_Deleted: 4967 S.Diag(Loc, Diag); 4968 S.NoteDeletedFunction(Best->Function); 4969 break; 4970 } 4971} 4972 4973void InitializationSequence::PrintInitLocationNote(Sema &S, 4974 const InitializedEntity &Entity) { 4975 if (Entity.getKind() == InitializedEntity::EK_Parameter && Entity.getDecl()) { 4976 if (Entity.getDecl()->getLocation().isInvalid()) 4977 return; 4978 4979 if (Entity.getDecl()->getDeclName()) 4980 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_named_here) 4981 << Entity.getDecl()->getDeclName(); 4982 else 4983 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_here); 4984 } 4985} 4986 4987static bool isReferenceBinding(const InitializationSequence::Step &s) { 4988 return s.Kind == InitializationSequence::SK_BindReference || 4989 s.Kind == InitializationSequence::SK_BindReferenceToTemporary; 4990} 4991 4992/// Returns true if the parameters describe a constructor initialization of 4993/// an explicit temporary object, e.g. "Point(x, y)". 4994static bool isExplicitTemporary(const InitializedEntity &Entity, 4995 const InitializationKind &Kind, 4996 unsigned NumArgs) { 4997 switch (Entity.getKind()) { 4998 case InitializedEntity::EK_Temporary: 4999 case InitializedEntity::EK_CompoundLiteralInit: 5000 break; 5001 default: 5002 return false; 5003 } 5004 5005 switch (Kind.getKind()) { 5006 case InitializationKind::IK_DirectList: 5007 return true; 5008 // FIXME: Hack to work around cast weirdness. 5009 case InitializationKind::IK_Direct: 5010 case InitializationKind::IK_Value: 5011 return NumArgs != 1; 5012 default: 5013 return false; 5014 } 5015} 5016 5017static ExprResult 5018PerformConstructorInitialization(Sema &S, 5019 const InitializedEntity &Entity, 5020 const InitializationKind &Kind, 5021 MultiExprArg Args, 5022 const InitializationSequence::Step& Step, 5023 bool &ConstructorInitRequiresZeroInit, 5024 bool IsListInitialization) { 5025 unsigned NumArgs = Args.size(); 5026 CXXConstructorDecl *Constructor 5027 = cast<CXXConstructorDecl>(Step.Function.Function); 5028 bool HadMultipleCandidates = Step.Function.HadMultipleCandidates; 5029 5030 // Build a call to the selected constructor. 5031 SmallVector<Expr*, 8> ConstructorArgs; 5032 SourceLocation Loc = (Kind.isCopyInit() && Kind.getEqualLoc().isValid()) 5033 ? Kind.getEqualLoc() 5034 : Kind.getLocation(); 5035 5036 if (Kind.getKind() == InitializationKind::IK_Default) { 5037 // Force even a trivial, implicit default constructor to be 5038 // semantically checked. We do this explicitly because we don't build 5039 // the definition for completely trivial constructors. 5040 assert(Constructor->getParent() && "No parent class for constructor."); 5041 if (Constructor->isDefaulted() && Constructor->isDefaultConstructor() && 5042 Constructor->isTrivial() && !Constructor->isUsed(false)) 5043 S.DefineImplicitDefaultConstructor(Loc, Constructor); 5044 } 5045 5046 ExprResult CurInit = S.Owned((Expr *)0); 5047 5048 // C++ [over.match.copy]p1: 5049 // - When initializing a temporary to be bound to the first parameter 5050 // of a constructor that takes a reference to possibly cv-qualified 5051 // T as its first argument, called with a single argument in the 5052 // context of direct-initialization, explicit conversion functions 5053 // are also considered. 5054 bool AllowExplicitConv = Kind.AllowExplicit() && !Kind.isCopyInit() && 5055 Args.size() == 1 && 5056 Constructor->isCopyOrMoveConstructor(); 5057 5058 // Determine the arguments required to actually perform the constructor 5059 // call. 5060 if (S.CompleteConstructorCall(Constructor, Args, 5061 Loc, ConstructorArgs, 5062 AllowExplicitConv, 5063 IsListInitialization)) 5064 return ExprError(); 5065 5066 5067 if (isExplicitTemporary(Entity, Kind, NumArgs)) { 5068 // An explicitly-constructed temporary, e.g., X(1, 2). 5069 S.MarkFunctionReferenced(Loc, Constructor); 5070 if (S.DiagnoseUseOfDecl(Constructor, Loc)) 5071 return ExprError(); 5072 5073 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo(); 5074 if (!TSInfo) 5075 TSInfo = S.Context.getTrivialTypeSourceInfo(Entity.getType(), Loc); 5076 SourceRange ParenRange; 5077 if (Kind.getKind() != InitializationKind::IK_DirectList) 5078 ParenRange = Kind.getParenRange(); 5079 5080 CurInit = S.Owned( 5081 new (S.Context) CXXTemporaryObjectExpr(S.Context, Constructor, 5082 TSInfo, ConstructorArgs, 5083 ParenRange, IsListInitialization, 5084 HadMultipleCandidates, 5085 ConstructorInitRequiresZeroInit)); 5086 } else { 5087 CXXConstructExpr::ConstructionKind ConstructKind = 5088 CXXConstructExpr::CK_Complete; 5089 5090 if (Entity.getKind() == InitializedEntity::EK_Base) { 5091 ConstructKind = Entity.getBaseSpecifier()->isVirtual() ? 5092 CXXConstructExpr::CK_VirtualBase : 5093 CXXConstructExpr::CK_NonVirtualBase; 5094 } else if (Entity.getKind() == InitializedEntity::EK_Delegating) { 5095 ConstructKind = CXXConstructExpr::CK_Delegating; 5096 } 5097 5098 // Only get the parenthesis range if it is a direct construction. 5099 SourceRange parenRange = 5100 Kind.getKind() == InitializationKind::IK_Direct ? 5101 Kind.getParenRange() : SourceRange(); 5102 5103 // If the entity allows NRVO, mark the construction as elidable 5104 // unconditionally. 5105 if (Entity.allowsNRVO()) 5106 CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(), 5107 Constructor, /*Elidable=*/true, 5108 ConstructorArgs, 5109 HadMultipleCandidates, 5110 IsListInitialization, 5111 ConstructorInitRequiresZeroInit, 5112 ConstructKind, 5113 parenRange); 5114 else 5115 CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(), 5116 Constructor, 5117 ConstructorArgs, 5118 HadMultipleCandidates, 5119 IsListInitialization, 5120 ConstructorInitRequiresZeroInit, 5121 ConstructKind, 5122 parenRange); 5123 } 5124 if (CurInit.isInvalid()) 5125 return ExprError(); 5126 5127 // Only check access if all of that succeeded. 5128 S.CheckConstructorAccess(Loc, Constructor, Entity, 5129 Step.Function.FoundDecl.getAccess()); 5130 if (S.DiagnoseUseOfDecl(Step.Function.FoundDecl, Loc)) 5131 return ExprError(); 5132 5133 if (shouldBindAsTemporary(Entity)) 5134 CurInit = S.MaybeBindToTemporary(CurInit.take()); 5135 5136 return CurInit; 5137} 5138 5139/// Determine whether the specified InitializedEntity definitely has a lifetime 5140/// longer than the current full-expression. Conservatively returns false if 5141/// it's unclear. 5142static bool 5143InitializedEntityOutlivesFullExpression(const InitializedEntity &Entity) { 5144 const InitializedEntity *Top = &Entity; 5145 while (Top->getParent()) 5146 Top = Top->getParent(); 5147 5148 switch (Top->getKind()) { 5149 case InitializedEntity::EK_Variable: 5150 case InitializedEntity::EK_Result: 5151 case InitializedEntity::EK_Exception: 5152 case InitializedEntity::EK_Member: 5153 case InitializedEntity::EK_New: 5154 case InitializedEntity::EK_Base: 5155 case InitializedEntity::EK_Delegating: 5156 return true; 5157 5158 case InitializedEntity::EK_ArrayElement: 5159 case InitializedEntity::EK_VectorElement: 5160 case InitializedEntity::EK_BlockElement: 5161 case InitializedEntity::EK_ComplexElement: 5162 // Could not determine what the full initialization is. Assume it might not 5163 // outlive the full-expression. 5164 return false; 5165 5166 case InitializedEntity::EK_Parameter: 5167 case InitializedEntity::EK_Temporary: 5168 case InitializedEntity::EK_LambdaCapture: 5169 case InitializedEntity::EK_CompoundLiteralInit: 5170 // The entity being initialized might not outlive the full-expression. 5171 return false; 5172 } 5173 5174 llvm_unreachable("unknown entity kind"); 5175} 5176 5177/// Determine the declaration which an initialized entity ultimately refers to, 5178/// for the purpose of lifetime-extending a temporary bound to a reference in 5179/// the initialization of \p Entity. 5180static const ValueDecl * 5181getDeclForTemporaryLifetimeExtension(const InitializedEntity &Entity, 5182 const ValueDecl *FallbackDecl = 0) { 5183 // C++11 [class.temporary]p5: 5184 switch (Entity.getKind()) { 5185 case InitializedEntity::EK_Variable: 5186 // The temporary [...] persists for the lifetime of the reference 5187 return Entity.getDecl(); 5188 5189 case InitializedEntity::EK_Member: 5190 // For subobjects, we look at the complete object. 5191 if (Entity.getParent()) 5192 return getDeclForTemporaryLifetimeExtension(*Entity.getParent(), 5193 Entity.getDecl()); 5194 5195 // except: 5196 // -- A temporary bound to a reference member in a constructor's 5197 // ctor-initializer persists until the constructor exits. 5198 return Entity.getDecl(); 5199 5200 case InitializedEntity::EK_Parameter: 5201 // -- A temporary bound to a reference parameter in a function call 5202 // persists until the completion of the full-expression containing 5203 // the call. 5204 case InitializedEntity::EK_Result: 5205 // -- The lifetime of a temporary bound to the returned value in a 5206 // function return statement is not extended; the temporary is 5207 // destroyed at the end of the full-expression in the return statement. 5208 case InitializedEntity::EK_New: 5209 // -- A temporary bound to a reference in a new-initializer persists 5210 // until the completion of the full-expression containing the 5211 // new-initializer. 5212 return 0; 5213 5214 case InitializedEntity::EK_Temporary: 5215 case InitializedEntity::EK_CompoundLiteralInit: 5216 // We don't yet know the storage duration of the surrounding temporary. 5217 // Assume it's got full-expression duration for now, it will patch up our 5218 // storage duration if that's not correct. 5219 return 0; 5220 5221 case InitializedEntity::EK_ArrayElement: 5222 // For subobjects, we look at the complete object. 5223 return getDeclForTemporaryLifetimeExtension(*Entity.getParent(), 5224 FallbackDecl); 5225 5226 case InitializedEntity::EK_Base: 5227 case InitializedEntity::EK_Delegating: 5228 // We can reach this case for aggregate initialization in a constructor: 5229 // struct A { int &&r; }; 5230 // struct B : A { B() : A{0} {} }; 5231 // In this case, use the innermost field decl as the context. 5232 return FallbackDecl; 5233 5234 case InitializedEntity::EK_BlockElement: 5235 case InitializedEntity::EK_LambdaCapture: 5236 case InitializedEntity::EK_Exception: 5237 case InitializedEntity::EK_VectorElement: 5238 case InitializedEntity::EK_ComplexElement: 5239 llvm_unreachable("should not materialize a temporary to initialize this"); 5240 } 5241 llvm_unreachable("unknown entity kind"); 5242} 5243 5244static void performLifetimeExtension(Expr *Init, const ValueDecl *ExtendingD); 5245 5246/// Update a glvalue expression that is used as the initializer of a reference 5247/// to note that its lifetime is extended. 5248static void performReferenceExtension(Expr *Init, const ValueDecl *ExtendingD) { 5249 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) { 5250 if (ILE->getNumInits() == 1 && ILE->isGLValue()) { 5251 // This is just redundant braces around an initializer. Step over it. 5252 Init = ILE->getInit(0); 5253 } 5254 } 5255 5256 if (MaterializeTemporaryExpr *ME = dyn_cast<MaterializeTemporaryExpr>(Init)) { 5257 // Update the storage duration of the materialized temporary. 5258 // FIXME: Rebuild the expression instead of mutating it. 5259 ME->setExtendingDecl(ExtendingD); 5260 performLifetimeExtension(ME->GetTemporaryExpr(), ExtendingD); 5261 } 5262} 5263 5264/// Update a prvalue expression that is going to be materialized as a 5265/// lifetime-extended temporary. 5266static void performLifetimeExtension(Expr *Init, const ValueDecl *ExtendingD) { 5267 // Dig out the expression which constructs the extended temporary. 5268 SmallVector<const Expr *, 2> CommaLHSs; 5269 SmallVector<SubobjectAdjustment, 2> Adjustments; 5270 Init = const_cast<Expr *>( 5271 Init->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments)); 5272 5273 if (CXXBindTemporaryExpr *BTE = dyn_cast<CXXBindTemporaryExpr>(Init)) 5274 Init = BTE->getSubExpr(); 5275 5276 if (CXXStdInitializerListExpr *ILE = 5277 dyn_cast<CXXStdInitializerListExpr>(Init)) 5278 return performReferenceExtension(ILE->getSubExpr(), ExtendingD); 5279 5280 if (InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) { 5281 if (ILE->getType()->isArrayType()) { 5282 for (unsigned I = 0, N = ILE->getNumInits(); I != N; ++I) 5283 performLifetimeExtension(ILE->getInit(I), ExtendingD); 5284 return; 5285 } 5286 5287 if (CXXRecordDecl *RD = ILE->getType()->getAsCXXRecordDecl()) { 5288 assert(RD->isAggregate() && "aggregate init on non-aggregate"); 5289 5290 // If we lifetime-extend a braced initializer which is initializing an 5291 // aggregate, and that aggregate contains reference members which are 5292 // bound to temporaries, those temporaries are also lifetime-extended. 5293 if (RD->isUnion() && ILE->getInitializedFieldInUnion() && 5294 ILE->getInitializedFieldInUnion()->getType()->isReferenceType()) 5295 performReferenceExtension(ILE->getInit(0), ExtendingD); 5296 else { 5297 unsigned Index = 0; 5298 for (RecordDecl::field_iterator I = RD->field_begin(), 5299 E = RD->field_end(); 5300 I != E; ++I) { 5301 if (I->isUnnamedBitfield()) 5302 continue; 5303 if (I->getType()->isReferenceType()) 5304 performReferenceExtension(ILE->getInit(Index), ExtendingD); 5305 else if (isa<InitListExpr>(ILE->getInit(Index))) 5306 // This may be either aggregate-initialization of a member or 5307 // initialization of a std::initializer_list object. Either way, 5308 // we should recursively lifetime-extend that initializer. 5309 performLifetimeExtension(ILE->getInit(Index), ExtendingD); 5310 ++Index; 5311 } 5312 } 5313 } 5314 } 5315} 5316 5317static void warnOnLifetimeExtension(Sema &S, const InitializedEntity &Entity, 5318 const Expr *Init, bool IsInitializerList, 5319 const ValueDecl *ExtendingDecl) { 5320 // Warn if a field lifetime-extends a temporary. 5321 if (isa<FieldDecl>(ExtendingDecl)) { 5322 if (IsInitializerList) { 5323 S.Diag(Init->getExprLoc(), diag::warn_dangling_std_initializer_list) 5324 << /*at end of constructor*/true; 5325 return; 5326 } 5327 5328 bool IsSubobjectMember = false; 5329 for (const InitializedEntity *Ent = Entity.getParent(); Ent; 5330 Ent = Ent->getParent()) { 5331 if (Ent->getKind() != InitializedEntity::EK_Base) { 5332 IsSubobjectMember = true; 5333 break; 5334 } 5335 } 5336 S.Diag(Init->getExprLoc(), 5337 diag::warn_bind_ref_member_to_temporary) 5338 << ExtendingDecl << Init->getSourceRange() 5339 << IsSubobjectMember << IsInitializerList; 5340 if (IsSubobjectMember) 5341 S.Diag(ExtendingDecl->getLocation(), 5342 diag::note_ref_subobject_of_member_declared_here); 5343 else 5344 S.Diag(ExtendingDecl->getLocation(), 5345 diag::note_ref_or_ptr_member_declared_here) 5346 << /*is pointer*/false; 5347 } 5348} 5349 5350ExprResult 5351InitializationSequence::Perform(Sema &S, 5352 const InitializedEntity &Entity, 5353 const InitializationKind &Kind, 5354 MultiExprArg Args, 5355 QualType *ResultType) { 5356 if (Failed()) { 5357 Diagnose(S, Entity, Kind, Args); 5358 return ExprError(); 5359 } 5360 5361 if (getKind() == DependentSequence) { 5362 // If the declaration is a non-dependent, incomplete array type 5363 // that has an initializer, then its type will be completed once 5364 // the initializer is instantiated. 5365 if (ResultType && !Entity.getType()->isDependentType() && 5366 Args.size() == 1) { 5367 QualType DeclType = Entity.getType(); 5368 if (const IncompleteArrayType *ArrayT 5369 = S.Context.getAsIncompleteArrayType(DeclType)) { 5370 // FIXME: We don't currently have the ability to accurately 5371 // compute the length of an initializer list without 5372 // performing full type-checking of the initializer list 5373 // (since we have to determine where braces are implicitly 5374 // introduced and such). So, we fall back to making the array 5375 // type a dependently-sized array type with no specified 5376 // bound. 5377 if (isa<InitListExpr>((Expr *)Args[0])) { 5378 SourceRange Brackets; 5379 5380 // Scavange the location of the brackets from the entity, if we can. 5381 if (DeclaratorDecl *DD = Entity.getDecl()) { 5382 if (TypeSourceInfo *TInfo = DD->getTypeSourceInfo()) { 5383 TypeLoc TL = TInfo->getTypeLoc(); 5384 if (IncompleteArrayTypeLoc ArrayLoc = 5385 TL.getAs<IncompleteArrayTypeLoc>()) 5386 Brackets = ArrayLoc.getBracketsRange(); 5387 } 5388 } 5389 5390 *ResultType 5391 = S.Context.getDependentSizedArrayType(ArrayT->getElementType(), 5392 /*NumElts=*/0, 5393 ArrayT->getSizeModifier(), 5394 ArrayT->getIndexTypeCVRQualifiers(), 5395 Brackets); 5396 } 5397 5398 } 5399 } 5400 if (Kind.getKind() == InitializationKind::IK_Direct && 5401 !Kind.isExplicitCast()) { 5402 // Rebuild the ParenListExpr. 5403 SourceRange ParenRange = Kind.getParenRange(); 5404 return S.ActOnParenListExpr(ParenRange.getBegin(), ParenRange.getEnd(), 5405 Args); 5406 } 5407 assert(Kind.getKind() == InitializationKind::IK_Copy || 5408 Kind.isExplicitCast() || 5409 Kind.getKind() == InitializationKind::IK_DirectList); 5410 return ExprResult(Args[0]); 5411 } 5412 5413 // No steps means no initialization. 5414 if (Steps.empty()) 5415 return S.Owned((Expr *)0); 5416 5417 if (S.getLangOpts().CPlusPlus11 && Entity.getType()->isReferenceType() && 5418 Args.size() == 1 && isa<InitListExpr>(Args[0]) && 5419 Entity.getKind() != InitializedEntity::EK_Parameter) { 5420 // Produce a C++98 compatibility warning if we are initializing a reference 5421 // from an initializer list. For parameters, we produce a better warning 5422 // elsewhere. 5423 Expr *Init = Args[0]; 5424 S.Diag(Init->getLocStart(), diag::warn_cxx98_compat_reference_list_init) 5425 << Init->getSourceRange(); 5426 } 5427 5428 // Diagnose cases where we initialize a pointer to an array temporary, and the 5429 // pointer obviously outlives the temporary. 5430 if (Args.size() == 1 && Args[0]->getType()->isArrayType() && 5431 Entity.getType()->isPointerType() && 5432 InitializedEntityOutlivesFullExpression(Entity)) { 5433 Expr *Init = Args[0]; 5434 Expr::LValueClassification Kind = Init->ClassifyLValue(S.Context); 5435 if (Kind == Expr::LV_ClassTemporary || Kind == Expr::LV_ArrayTemporary) 5436 S.Diag(Init->getLocStart(), diag::warn_temporary_array_to_pointer_decay) 5437 << Init->getSourceRange(); 5438 } 5439 5440 QualType DestType = Entity.getType().getNonReferenceType(); 5441 // FIXME: Ugly hack around the fact that Entity.getType() is not 5442 // the same as Entity.getDecl()->getType() in cases involving type merging, 5443 // and we want latter when it makes sense. 5444 if (ResultType) 5445 *ResultType = Entity.getDecl() ? Entity.getDecl()->getType() : 5446 Entity.getType(); 5447 5448 ExprResult CurInit = S.Owned((Expr *)0); 5449 5450 // For initialization steps that start with a single initializer, 5451 // grab the only argument out the Args and place it into the "current" 5452 // initializer. 5453 switch (Steps.front().Kind) { 5454 case SK_ResolveAddressOfOverloadedFunction: 5455 case SK_CastDerivedToBaseRValue: 5456 case SK_CastDerivedToBaseXValue: 5457 case SK_CastDerivedToBaseLValue: 5458 case SK_BindReference: 5459 case SK_BindReferenceToTemporary: 5460 case SK_ExtraneousCopyToTemporary: 5461 case SK_UserConversion: 5462 case SK_QualificationConversionLValue: 5463 case SK_QualificationConversionXValue: 5464 case SK_QualificationConversionRValue: 5465 case SK_LValueToRValue: 5466 case SK_ConversionSequence: 5467 case SK_ListInitialization: 5468 case SK_UnwrapInitList: 5469 case SK_RewrapInitList: 5470 case SK_CAssignment: 5471 case SK_StringInit: 5472 case SK_ObjCObjectConversion: 5473 case SK_ArrayInit: 5474 case SK_ParenthesizedArrayInit: 5475 case SK_PassByIndirectCopyRestore: 5476 case SK_PassByIndirectRestore: 5477 case SK_ProduceObjCObject: 5478 case SK_StdInitializerList: 5479 case SK_OCLSamplerInit: 5480 case SK_OCLZeroEvent: { 5481 assert(Args.size() == 1); 5482 CurInit = Args[0]; 5483 if (!CurInit.get()) return ExprError(); 5484 break; 5485 } 5486 5487 case SK_ConstructorInitialization: 5488 case SK_ListConstructorCall: 5489 case SK_ZeroInitialization: 5490 break; 5491 } 5492 5493 // Walk through the computed steps for the initialization sequence, 5494 // performing the specified conversions along the way. 5495 bool ConstructorInitRequiresZeroInit = false; 5496 for (step_iterator Step = step_begin(), StepEnd = step_end(); 5497 Step != StepEnd; ++Step) { 5498 if (CurInit.isInvalid()) 5499 return ExprError(); 5500 5501 QualType SourceType = CurInit.get() ? CurInit.get()->getType() : QualType(); 5502 5503 switch (Step->Kind) { 5504 case SK_ResolveAddressOfOverloadedFunction: 5505 // Overload resolution determined which function invoke; update the 5506 // initializer to reflect that choice. 5507 S.CheckAddressOfMemberAccess(CurInit.get(), Step->Function.FoundDecl); 5508 if (S.DiagnoseUseOfDecl(Step->Function.FoundDecl, Kind.getLocation())) 5509 return ExprError(); 5510 CurInit = S.FixOverloadedFunctionReference(CurInit, 5511 Step->Function.FoundDecl, 5512 Step->Function.Function); 5513 break; 5514 5515 case SK_CastDerivedToBaseRValue: 5516 case SK_CastDerivedToBaseXValue: 5517 case SK_CastDerivedToBaseLValue: { 5518 // We have a derived-to-base cast that produces either an rvalue or an 5519 // lvalue. Perform that cast. 5520 5521 CXXCastPath BasePath; 5522 5523 // Casts to inaccessible base classes are allowed with C-style casts. 5524 bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast(); 5525 if (S.CheckDerivedToBaseConversion(SourceType, Step->Type, 5526 CurInit.get()->getLocStart(), 5527 CurInit.get()->getSourceRange(), 5528 &BasePath, IgnoreBaseAccess)) 5529 return ExprError(); 5530 5531 if (S.BasePathInvolvesVirtualBase(BasePath)) { 5532 QualType T = SourceType; 5533 if (const PointerType *Pointer = T->getAs<PointerType>()) 5534 T = Pointer->getPointeeType(); 5535 if (const RecordType *RecordTy = T->getAs<RecordType>()) 5536 S.MarkVTableUsed(CurInit.get()->getLocStart(), 5537 cast<CXXRecordDecl>(RecordTy->getDecl())); 5538 } 5539 5540 ExprValueKind VK = 5541 Step->Kind == SK_CastDerivedToBaseLValue ? 5542 VK_LValue : 5543 (Step->Kind == SK_CastDerivedToBaseXValue ? 5544 VK_XValue : 5545 VK_RValue); 5546 CurInit = S.Owned(ImplicitCastExpr::Create(S.Context, 5547 Step->Type, 5548 CK_DerivedToBase, 5549 CurInit.get(), 5550 &BasePath, VK)); 5551 break; 5552 } 5553 5554 case SK_BindReference: 5555 // References cannot bind to bit-fields (C++ [dcl.init.ref]p5). 5556 if (CurInit.get()->refersToBitField()) { 5557 // We don't necessarily have an unambiguous source bit-field. 5558 FieldDecl *BitField = CurInit.get()->getSourceBitField(); 5559 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield) 5560 << Entity.getType().isVolatileQualified() 5561 << (BitField ? BitField->getDeclName() : DeclarationName()) 5562 << (BitField != NULL) 5563 << CurInit.get()->getSourceRange(); 5564 if (BitField) 5565 S.Diag(BitField->getLocation(), diag::note_bitfield_decl); 5566 5567 return ExprError(); 5568 } 5569 5570 if (CurInit.get()->refersToVectorElement()) { 5571 // References cannot bind to vector elements. 5572 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_vector_element) 5573 << Entity.getType().isVolatileQualified() 5574 << CurInit.get()->getSourceRange(); 5575 PrintInitLocationNote(S, Entity); 5576 return ExprError(); 5577 } 5578 5579 // Reference binding does not have any corresponding ASTs. 5580 5581 // Check exception specifications 5582 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType)) 5583 return ExprError(); 5584 5585 break; 5586 5587 case SK_BindReferenceToTemporary: { 5588 // Make sure the "temporary" is actually an rvalue. 5589 assert(CurInit.get()->isRValue() && "not a temporary"); 5590 5591 // Check exception specifications 5592 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType)) 5593 return ExprError(); 5594 5595 // Maybe lifetime-extend the temporary's subobjects to match the 5596 // entity's lifetime. 5597 const ValueDecl *ExtendingDecl = 5598 getDeclForTemporaryLifetimeExtension(Entity); 5599 if (ExtendingDecl) { 5600 performLifetimeExtension(CurInit.get(), ExtendingDecl); 5601 warnOnLifetimeExtension(S, Entity, CurInit.get(), false, ExtendingDecl); 5602 } 5603 5604 // Materialize the temporary into memory. 5605 MaterializeTemporaryExpr *MTE = new (S.Context) MaterializeTemporaryExpr( 5606 Entity.getType().getNonReferenceType(), CurInit.get(), 5607 Entity.getType()->isLValueReferenceType(), ExtendingDecl); 5608 5609 // If we're binding to an Objective-C object that has lifetime, we 5610 // need cleanups. Likewise if we're extending this temporary to automatic 5611 // storage duration -- we need to register its cleanup during the 5612 // full-expression's cleanups. 5613 if ((S.getLangOpts().ObjCAutoRefCount && 5614 MTE->getType()->isObjCLifetimeType()) || 5615 (MTE->getStorageDuration() == SD_Automatic && 5616 MTE->getType().isDestructedType())) 5617 S.ExprNeedsCleanups = true; 5618 5619 CurInit = S.Owned(MTE); 5620 break; 5621 } 5622 5623 case SK_ExtraneousCopyToTemporary: 5624 CurInit = CopyObject(S, Step->Type, Entity, CurInit, 5625 /*IsExtraneousCopy=*/true); 5626 break; 5627 5628 case SK_UserConversion: { 5629 // We have a user-defined conversion that invokes either a constructor 5630 // or a conversion function. 5631 CastKind CastKind; 5632 bool IsCopy = false; 5633 FunctionDecl *Fn = Step->Function.Function; 5634 DeclAccessPair FoundFn = Step->Function.FoundDecl; 5635 bool HadMultipleCandidates = Step->Function.HadMultipleCandidates; 5636 bool CreatedObject = false; 5637 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Fn)) { 5638 // Build a call to the selected constructor. 5639 SmallVector<Expr*, 8> ConstructorArgs; 5640 SourceLocation Loc = CurInit.get()->getLocStart(); 5641 CurInit.release(); // Ownership transferred into MultiExprArg, below. 5642 5643 // Determine the arguments required to actually perform the constructor 5644 // call. 5645 Expr *Arg = CurInit.get(); 5646 if (S.CompleteConstructorCall(Constructor, 5647 MultiExprArg(&Arg, 1), 5648 Loc, ConstructorArgs)) 5649 return ExprError(); 5650 5651 // Build an expression that constructs a temporary. 5652 CurInit = S.BuildCXXConstructExpr(Loc, Step->Type, Constructor, 5653 ConstructorArgs, 5654 HadMultipleCandidates, 5655 /*ListInit*/ false, 5656 /*ZeroInit*/ false, 5657 CXXConstructExpr::CK_Complete, 5658 SourceRange()); 5659 if (CurInit.isInvalid()) 5660 return ExprError(); 5661 5662 S.CheckConstructorAccess(Kind.getLocation(), Constructor, Entity, 5663 FoundFn.getAccess()); 5664 if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation())) 5665 return ExprError(); 5666 5667 CastKind = CK_ConstructorConversion; 5668 QualType Class = S.Context.getTypeDeclType(Constructor->getParent()); 5669 if (S.Context.hasSameUnqualifiedType(SourceType, Class) || 5670 S.IsDerivedFrom(SourceType, Class)) 5671 IsCopy = true; 5672 5673 CreatedObject = true; 5674 } else { 5675 // Build a call to the conversion function. 5676 CXXConversionDecl *Conversion = cast<CXXConversionDecl>(Fn); 5677 S.CheckMemberOperatorAccess(Kind.getLocation(), CurInit.get(), 0, 5678 FoundFn); 5679 if (S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation())) 5680 return ExprError(); 5681 5682 // FIXME: Should we move this initialization into a separate 5683 // derived-to-base conversion? I believe the answer is "no", because 5684 // we don't want to turn off access control here for c-style casts. 5685 ExprResult CurInitExprRes = 5686 S.PerformObjectArgumentInitialization(CurInit.take(), /*Qualifier=*/0, 5687 FoundFn, Conversion); 5688 if(CurInitExprRes.isInvalid()) 5689 return ExprError(); 5690 CurInit = CurInitExprRes; 5691 5692 // Build the actual call to the conversion function. 5693 CurInit = S.BuildCXXMemberCallExpr(CurInit.get(), FoundFn, Conversion, 5694 HadMultipleCandidates); 5695 if (CurInit.isInvalid() || !CurInit.get()) 5696 return ExprError(); 5697 5698 CastKind = CK_UserDefinedConversion; 5699 5700 CreatedObject = Conversion->getResultType()->isRecordType(); 5701 } 5702 5703 bool RequiresCopy = !IsCopy && !isReferenceBinding(Steps.back()); 5704 bool MaybeBindToTemp = RequiresCopy || shouldBindAsTemporary(Entity); 5705 5706 if (!MaybeBindToTemp && CreatedObject && shouldDestroyTemporary(Entity)) { 5707 QualType T = CurInit.get()->getType(); 5708 if (const RecordType *Record = T->getAs<RecordType>()) { 5709 CXXDestructorDecl *Destructor 5710 = S.LookupDestructor(cast<CXXRecordDecl>(Record->getDecl())); 5711 S.CheckDestructorAccess(CurInit.get()->getLocStart(), Destructor, 5712 S.PDiag(diag::err_access_dtor_temp) << T); 5713 S.MarkFunctionReferenced(CurInit.get()->getLocStart(), Destructor); 5714 if (S.DiagnoseUseOfDecl(Destructor, CurInit.get()->getLocStart())) 5715 return ExprError(); 5716 } 5717 } 5718 5719 CurInit = S.Owned(ImplicitCastExpr::Create(S.Context, 5720 CurInit.get()->getType(), 5721 CastKind, CurInit.get(), 0, 5722 CurInit.get()->getValueKind())); 5723 if (MaybeBindToTemp) 5724 CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>()); 5725 if (RequiresCopy) 5726 CurInit = CopyObject(S, Entity.getType().getNonReferenceType(), Entity, 5727 CurInit, /*IsExtraneousCopy=*/false); 5728 break; 5729 } 5730 5731 case SK_QualificationConversionLValue: 5732 case SK_QualificationConversionXValue: 5733 case SK_QualificationConversionRValue: { 5734 // Perform a qualification conversion; these can never go wrong. 5735 ExprValueKind VK = 5736 Step->Kind == SK_QualificationConversionLValue ? 5737 VK_LValue : 5738 (Step->Kind == SK_QualificationConversionXValue ? 5739 VK_XValue : 5740 VK_RValue); 5741 CurInit = S.ImpCastExprToType(CurInit.take(), Step->Type, CK_NoOp, VK); 5742 break; 5743 } 5744 5745 case SK_LValueToRValue: { 5746 assert(CurInit.get()->isGLValue() && "cannot load from a prvalue"); 5747 CurInit = S.Owned(ImplicitCastExpr::Create(S.Context, Step->Type, 5748 CK_LValueToRValue, 5749 CurInit.take(), 5750 /*BasePath=*/0, 5751 VK_RValue)); 5752 break; 5753 } 5754 5755 case SK_ConversionSequence: { 5756 Sema::CheckedConversionKind CCK 5757 = Kind.isCStyleCast()? Sema::CCK_CStyleCast 5758 : Kind.isFunctionalCast()? Sema::CCK_FunctionalCast 5759 : Kind.isExplicitCast()? Sema::CCK_OtherCast 5760 : Sema::CCK_ImplicitConversion; 5761 ExprResult CurInitExprRes = 5762 S.PerformImplicitConversion(CurInit.get(), Step->Type, *Step->ICS, 5763 getAssignmentAction(Entity), CCK); 5764 if (CurInitExprRes.isInvalid()) 5765 return ExprError(); 5766 CurInit = CurInitExprRes; 5767 break; 5768 } 5769 5770 case SK_ListInitialization: { 5771 InitListExpr *InitList = cast<InitListExpr>(CurInit.get()); 5772 // If we're not initializing the top-level entity, we need to create an 5773 // InitializeTemporary entity for our target type. 5774 QualType Ty = Step->Type; 5775 bool IsTemporary = !S.Context.hasSameType(Entity.getType(), Ty); 5776 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(Ty); 5777 InitializedEntity InitEntity = IsTemporary ? TempEntity : Entity; 5778 InitListChecker PerformInitList(S, InitEntity, 5779 InitList, Ty, /*VerifyOnly=*/false); 5780 if (PerformInitList.HadError()) 5781 return ExprError(); 5782 5783 // Hack: We must update *ResultType if available in order to set the 5784 // bounds of arrays, e.g. in 'int ar[] = {1, 2, 3};'. 5785 // Worst case: 'const int (&arref)[] = {1, 2, 3};'. 5786 if (ResultType && 5787 ResultType->getNonReferenceType()->isIncompleteArrayType()) { 5788 if ((*ResultType)->isRValueReferenceType()) 5789 Ty = S.Context.getRValueReferenceType(Ty); 5790 else if ((*ResultType)->isLValueReferenceType()) 5791 Ty = S.Context.getLValueReferenceType(Ty, 5792 (*ResultType)->getAs<LValueReferenceType>()->isSpelledAsLValue()); 5793 *ResultType = Ty; 5794 } 5795 5796 InitListExpr *StructuredInitList = 5797 PerformInitList.getFullyStructuredList(); 5798 CurInit.release(); 5799 CurInit = shouldBindAsTemporary(InitEntity) 5800 ? S.MaybeBindToTemporary(StructuredInitList) 5801 : S.Owned(StructuredInitList); 5802 break; 5803 } 5804 5805 case SK_ListConstructorCall: { 5806 // When an initializer list is passed for a parameter of type "reference 5807 // to object", we don't get an EK_Temporary entity, but instead an 5808 // EK_Parameter entity with reference type. 5809 // FIXME: This is a hack. What we really should do is create a user 5810 // conversion step for this case, but this makes it considerably more 5811 // complicated. For now, this will do. 5812 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary( 5813 Entity.getType().getNonReferenceType()); 5814 bool UseTemporary = Entity.getType()->isReferenceType(); 5815 assert(Args.size() == 1 && "expected a single argument for list init"); 5816 InitListExpr *InitList = cast<InitListExpr>(Args[0]); 5817 S.Diag(InitList->getExprLoc(), diag::warn_cxx98_compat_ctor_list_init) 5818 << InitList->getSourceRange(); 5819 MultiExprArg Arg(InitList->getInits(), InitList->getNumInits()); 5820 CurInit = PerformConstructorInitialization(S, UseTemporary ? TempEntity : 5821 Entity, 5822 Kind, Arg, *Step, 5823 ConstructorInitRequiresZeroInit, 5824 /*IsListInitialization*/ true); 5825 break; 5826 } 5827 5828 case SK_UnwrapInitList: 5829 CurInit = S.Owned(cast<InitListExpr>(CurInit.take())->getInit(0)); 5830 break; 5831 5832 case SK_RewrapInitList: { 5833 Expr *E = CurInit.take(); 5834 InitListExpr *Syntactic = Step->WrappingSyntacticList; 5835 InitListExpr *ILE = new (S.Context) InitListExpr(S.Context, 5836 Syntactic->getLBraceLoc(), E, Syntactic->getRBraceLoc()); 5837 ILE->setSyntacticForm(Syntactic); 5838 ILE->setType(E->getType()); 5839 ILE->setValueKind(E->getValueKind()); 5840 CurInit = S.Owned(ILE); 5841 break; 5842 } 5843 5844 case SK_ConstructorInitialization: { 5845 // When an initializer list is passed for a parameter of type "reference 5846 // to object", we don't get an EK_Temporary entity, but instead an 5847 // EK_Parameter entity with reference type. 5848 // FIXME: This is a hack. What we really should do is create a user 5849 // conversion step for this case, but this makes it considerably more 5850 // complicated. For now, this will do. 5851 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary( 5852 Entity.getType().getNonReferenceType()); 5853 bool UseTemporary = Entity.getType()->isReferenceType(); 5854 CurInit = PerformConstructorInitialization(S, UseTemporary ? TempEntity 5855 : Entity, 5856 Kind, Args, *Step, 5857 ConstructorInitRequiresZeroInit, 5858 /*IsListInitialization*/ false); 5859 break; 5860 } 5861 5862 case SK_ZeroInitialization: { 5863 step_iterator NextStep = Step; 5864 ++NextStep; 5865 if (NextStep != StepEnd && 5866 (NextStep->Kind == SK_ConstructorInitialization || 5867 NextStep->Kind == SK_ListConstructorCall)) { 5868 // The need for zero-initialization is recorded directly into 5869 // the call to the object's constructor within the next step. 5870 ConstructorInitRequiresZeroInit = true; 5871 } else if (Kind.getKind() == InitializationKind::IK_Value && 5872 S.getLangOpts().CPlusPlus && 5873 !Kind.isImplicitValueInit()) { 5874 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo(); 5875 if (!TSInfo) 5876 TSInfo = S.Context.getTrivialTypeSourceInfo(Step->Type, 5877 Kind.getRange().getBegin()); 5878 5879 CurInit = S.Owned(new (S.Context) CXXScalarValueInitExpr( 5880 TSInfo->getType().getNonLValueExprType(S.Context), 5881 TSInfo, 5882 Kind.getRange().getEnd())); 5883 } else { 5884 CurInit = S.Owned(new (S.Context) ImplicitValueInitExpr(Step->Type)); 5885 } 5886 break; 5887 } 5888 5889 case SK_CAssignment: { 5890 QualType SourceType = CurInit.get()->getType(); 5891 ExprResult Result = CurInit; 5892 Sema::AssignConvertType ConvTy = 5893 S.CheckSingleAssignmentConstraints(Step->Type, Result); 5894 if (Result.isInvalid()) 5895 return ExprError(); 5896 CurInit = Result; 5897 5898 // If this is a call, allow conversion to a transparent union. 5899 ExprResult CurInitExprRes = CurInit; 5900 if (ConvTy != Sema::Compatible && 5901 Entity.getKind() == InitializedEntity::EK_Parameter && 5902 S.CheckTransparentUnionArgumentConstraints(Step->Type, CurInitExprRes) 5903 == Sema::Compatible) 5904 ConvTy = Sema::Compatible; 5905 if (CurInitExprRes.isInvalid()) 5906 return ExprError(); 5907 CurInit = CurInitExprRes; 5908 5909 bool Complained; 5910 if (S.DiagnoseAssignmentResult(ConvTy, Kind.getLocation(), 5911 Step->Type, SourceType, 5912 CurInit.get(), 5913 getAssignmentAction(Entity), 5914 &Complained)) { 5915 PrintInitLocationNote(S, Entity); 5916 return ExprError(); 5917 } else if (Complained) 5918 PrintInitLocationNote(S, Entity); 5919 break; 5920 } 5921 5922 case SK_StringInit: { 5923 QualType Ty = Step->Type; 5924 CheckStringInit(CurInit.get(), ResultType ? *ResultType : Ty, 5925 S.Context.getAsArrayType(Ty), S); 5926 break; 5927 } 5928 5929 case SK_ObjCObjectConversion: 5930 CurInit = S.ImpCastExprToType(CurInit.take(), Step->Type, 5931 CK_ObjCObjectLValueCast, 5932 CurInit.get()->getValueKind()); 5933 break; 5934 5935 case SK_ArrayInit: 5936 // Okay: we checked everything before creating this step. Note that 5937 // this is a GNU extension. 5938 S.Diag(Kind.getLocation(), diag::ext_array_init_copy) 5939 << Step->Type << CurInit.get()->getType() 5940 << CurInit.get()->getSourceRange(); 5941 5942 // If the destination type is an incomplete array type, update the 5943 // type accordingly. 5944 if (ResultType) { 5945 if (const IncompleteArrayType *IncompleteDest 5946 = S.Context.getAsIncompleteArrayType(Step->Type)) { 5947 if (const ConstantArrayType *ConstantSource 5948 = S.Context.getAsConstantArrayType(CurInit.get()->getType())) { 5949 *ResultType = S.Context.getConstantArrayType( 5950 IncompleteDest->getElementType(), 5951 ConstantSource->getSize(), 5952 ArrayType::Normal, 0); 5953 } 5954 } 5955 } 5956 break; 5957 5958 case SK_ParenthesizedArrayInit: 5959 // Okay: we checked everything before creating this step. Note that 5960 // this is a GNU extension. 5961 S.Diag(Kind.getLocation(), diag::ext_array_init_parens) 5962 << CurInit.get()->getSourceRange(); 5963 break; 5964 5965 case SK_PassByIndirectCopyRestore: 5966 case SK_PassByIndirectRestore: 5967 checkIndirectCopyRestoreSource(S, CurInit.get()); 5968 CurInit = S.Owned(new (S.Context) 5969 ObjCIndirectCopyRestoreExpr(CurInit.take(), Step->Type, 5970 Step->Kind == SK_PassByIndirectCopyRestore)); 5971 break; 5972 5973 case SK_ProduceObjCObject: 5974 CurInit = S.Owned(ImplicitCastExpr::Create(S.Context, Step->Type, 5975 CK_ARCProduceObject, 5976 CurInit.take(), 0, VK_RValue)); 5977 break; 5978 5979 case SK_StdInitializerList: { 5980 S.Diag(CurInit.get()->getExprLoc(), 5981 diag::warn_cxx98_compat_initializer_list_init) 5982 << CurInit.get()->getSourceRange(); 5983 5984 // Maybe lifetime-extend the array temporary's subobjects to match the 5985 // entity's lifetime. 5986 const ValueDecl *ExtendingDecl = 5987 getDeclForTemporaryLifetimeExtension(Entity); 5988 if (ExtendingDecl) { 5989 performLifetimeExtension(CurInit.get(), ExtendingDecl); 5990 warnOnLifetimeExtension(S, Entity, CurInit.get(), true, ExtendingDecl); 5991 } 5992 5993 // Materialize the temporary into memory. 5994 MaterializeTemporaryExpr *MTE = new (S.Context) 5995 MaterializeTemporaryExpr(CurInit.get()->getType(), CurInit.get(), 5996 /*lvalue reference*/ false, ExtendingDecl); 5997 5998 // Wrap it in a construction of a std::initializer_list<T>. 5999 CurInit = S.Owned( 6000 new (S.Context) CXXStdInitializerListExpr(Step->Type, MTE)); 6001 6002 // Bind the result, in case the library has given initializer_list a 6003 // non-trivial destructor. 6004 if (shouldBindAsTemporary(Entity)) 6005 CurInit = S.MaybeBindToTemporary(CurInit.take()); 6006 break; 6007 } 6008 6009 case SK_OCLSamplerInit: { 6010 assert(Step->Type->isSamplerT() && 6011 "Sampler initialization on non sampler type."); 6012 6013 QualType SourceType = CurInit.get()->getType(); 6014 InitializedEntity::EntityKind EntityKind = Entity.getKind(); 6015 6016 if (EntityKind == InitializedEntity::EK_Parameter) { 6017 if (!SourceType->isSamplerT()) 6018 S.Diag(Kind.getLocation(), diag::err_sampler_argument_required) 6019 << SourceType; 6020 } else if (EntityKind != InitializedEntity::EK_Variable) { 6021 llvm_unreachable("Invalid EntityKind!"); 6022 } 6023 6024 break; 6025 } 6026 case SK_OCLZeroEvent: { 6027 assert(Step->Type->isEventT() && 6028 "Event initialization on non event type."); 6029 6030 CurInit = S.ImpCastExprToType(CurInit.take(), Step->Type, 6031 CK_ZeroToOCLEvent, 6032 CurInit.get()->getValueKind()); 6033 break; 6034 } 6035 } 6036 } 6037 6038 // Diagnose non-fatal problems with the completed initialization. 6039 if (Entity.getKind() == InitializedEntity::EK_Member && 6040 cast<FieldDecl>(Entity.getDecl())->isBitField()) 6041 S.CheckBitFieldInitialization(Kind.getLocation(), 6042 cast<FieldDecl>(Entity.getDecl()), 6043 CurInit.get()); 6044 6045 return CurInit; 6046} 6047 6048/// Somewhere within T there is an uninitialized reference subobject. 6049/// Dig it out and diagnose it. 6050static bool DiagnoseUninitializedReference(Sema &S, SourceLocation Loc, 6051 QualType T) { 6052 if (T->isReferenceType()) { 6053 S.Diag(Loc, diag::err_reference_without_init) 6054 << T.getNonReferenceType(); 6055 return true; 6056 } 6057 6058 CXXRecordDecl *RD = T->getBaseElementTypeUnsafe()->getAsCXXRecordDecl(); 6059 if (!RD || !RD->hasUninitializedReferenceMember()) 6060 return false; 6061 6062 for (CXXRecordDecl::field_iterator FI = RD->field_begin(), 6063 FE = RD->field_end(); FI != FE; ++FI) { 6064 if (FI->isUnnamedBitfield()) 6065 continue; 6066 6067 if (DiagnoseUninitializedReference(S, FI->getLocation(), FI->getType())) { 6068 S.Diag(Loc, diag::note_value_initialization_here) << RD; 6069 return true; 6070 } 6071 } 6072 6073 for (CXXRecordDecl::base_class_iterator BI = RD->bases_begin(), 6074 BE = RD->bases_end(); 6075 BI != BE; ++BI) { 6076 if (DiagnoseUninitializedReference(S, BI->getLocStart(), BI->getType())) { 6077 S.Diag(Loc, diag::note_value_initialization_here) << RD; 6078 return true; 6079 } 6080 } 6081 6082 return false; 6083} 6084 6085 6086//===----------------------------------------------------------------------===// 6087// Diagnose initialization failures 6088//===----------------------------------------------------------------------===// 6089 6090/// Emit notes associated with an initialization that failed due to a 6091/// "simple" conversion failure. 6092static void emitBadConversionNotes(Sema &S, const InitializedEntity &entity, 6093 Expr *op) { 6094 QualType destType = entity.getType(); 6095 if (destType.getNonReferenceType()->isObjCObjectPointerType() && 6096 op->getType()->isObjCObjectPointerType()) { 6097 6098 // Emit a possible note about the conversion failing because the 6099 // operand is a message send with a related result type. 6100 S.EmitRelatedResultTypeNote(op); 6101 6102 // Emit a possible note about a return failing because we're 6103 // expecting a related result type. 6104 if (entity.getKind() == InitializedEntity::EK_Result) 6105 S.EmitRelatedResultTypeNoteForReturn(destType); 6106 } 6107} 6108 6109bool InitializationSequence::Diagnose(Sema &S, 6110 const InitializedEntity &Entity, 6111 const InitializationKind &Kind, 6112 ArrayRef<Expr *> Args) { 6113 if (!Failed()) 6114 return false; 6115 6116 QualType DestType = Entity.getType(); 6117 switch (Failure) { 6118 case FK_TooManyInitsForReference: 6119 // FIXME: Customize for the initialized entity? 6120 if (Args.empty()) { 6121 // Dig out the reference subobject which is uninitialized and diagnose it. 6122 // If this is value-initialization, this could be nested some way within 6123 // the target type. 6124 assert(Kind.getKind() == InitializationKind::IK_Value || 6125 DestType->isReferenceType()); 6126 bool Diagnosed = 6127 DiagnoseUninitializedReference(S, Kind.getLocation(), DestType); 6128 assert(Diagnosed && "couldn't find uninitialized reference to diagnose"); 6129 (void)Diagnosed; 6130 } else // FIXME: diagnostic below could be better! 6131 S.Diag(Kind.getLocation(), diag::err_reference_has_multiple_inits) 6132 << SourceRange(Args.front()->getLocStart(), Args.back()->getLocEnd()); 6133 break; 6134 6135 case FK_ArrayNeedsInitList: 6136 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 0; 6137 break; 6138 case FK_ArrayNeedsInitListOrStringLiteral: 6139 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 1; 6140 break; 6141 case FK_ArrayNeedsInitListOrWideStringLiteral: 6142 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) << 2; 6143 break; 6144 case FK_NarrowStringIntoWideCharArray: 6145 S.Diag(Kind.getLocation(), diag::err_array_init_narrow_string_into_wchar); 6146 break; 6147 case FK_WideStringIntoCharArray: 6148 S.Diag(Kind.getLocation(), diag::err_array_init_wide_string_into_char); 6149 break; 6150 case FK_IncompatWideStringIntoWideChar: 6151 S.Diag(Kind.getLocation(), 6152 diag::err_array_init_incompat_wide_string_into_wchar); 6153 break; 6154 case FK_ArrayTypeMismatch: 6155 case FK_NonConstantArrayInit: 6156 S.Diag(Kind.getLocation(), 6157 (Failure == FK_ArrayTypeMismatch 6158 ? diag::err_array_init_different_type 6159 : diag::err_array_init_non_constant_array)) 6160 << DestType.getNonReferenceType() 6161 << Args[0]->getType() 6162 << Args[0]->getSourceRange(); 6163 break; 6164 6165 case FK_VariableLengthArrayHasInitializer: 6166 S.Diag(Kind.getLocation(), diag::err_variable_object_no_init) 6167 << Args[0]->getSourceRange(); 6168 break; 6169 6170 case FK_AddressOfOverloadFailed: { 6171 DeclAccessPair Found; 6172 S.ResolveAddressOfOverloadedFunction(Args[0], 6173 DestType.getNonReferenceType(), 6174 true, 6175 Found); 6176 break; 6177 } 6178 6179 case FK_ReferenceInitOverloadFailed: 6180 case FK_UserConversionOverloadFailed: 6181 switch (FailedOverloadResult) { 6182 case OR_Ambiguous: 6183 if (Failure == FK_UserConversionOverloadFailed) 6184 S.Diag(Kind.getLocation(), diag::err_typecheck_ambiguous_condition) 6185 << Args[0]->getType() << DestType 6186 << Args[0]->getSourceRange(); 6187 else 6188 S.Diag(Kind.getLocation(), diag::err_ref_init_ambiguous) 6189 << DestType << Args[0]->getType() 6190 << Args[0]->getSourceRange(); 6191 6192 FailedCandidateSet.NoteCandidates(S, OCD_ViableCandidates, Args); 6193 break; 6194 6195 case OR_No_Viable_Function: 6196 S.Diag(Kind.getLocation(), diag::err_typecheck_nonviable_condition) 6197 << Args[0]->getType() << DestType.getNonReferenceType() 6198 << Args[0]->getSourceRange(); 6199 FailedCandidateSet.NoteCandidates(S, OCD_AllCandidates, Args); 6200 break; 6201 6202 case OR_Deleted: { 6203 S.Diag(Kind.getLocation(), diag::err_typecheck_deleted_function) 6204 << Args[0]->getType() << DestType.getNonReferenceType() 6205 << Args[0]->getSourceRange(); 6206 OverloadCandidateSet::iterator Best; 6207 OverloadingResult Ovl 6208 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best, 6209 true); 6210 if (Ovl == OR_Deleted) { 6211 S.NoteDeletedFunction(Best->Function); 6212 } else { 6213 llvm_unreachable("Inconsistent overload resolution?"); 6214 } 6215 break; 6216 } 6217 6218 case OR_Success: 6219 llvm_unreachable("Conversion did not fail!"); 6220 } 6221 break; 6222 6223 case FK_NonConstLValueReferenceBindingToTemporary: 6224 if (isa<InitListExpr>(Args[0])) { 6225 S.Diag(Kind.getLocation(), 6226 diag::err_lvalue_reference_bind_to_initlist) 6227 << DestType.getNonReferenceType().isVolatileQualified() 6228 << DestType.getNonReferenceType() 6229 << Args[0]->getSourceRange(); 6230 break; 6231 } 6232 // Intentional fallthrough 6233 6234 case FK_NonConstLValueReferenceBindingToUnrelated: 6235 S.Diag(Kind.getLocation(), 6236 Failure == FK_NonConstLValueReferenceBindingToTemporary 6237 ? diag::err_lvalue_reference_bind_to_temporary 6238 : diag::err_lvalue_reference_bind_to_unrelated) 6239 << DestType.getNonReferenceType().isVolatileQualified() 6240 << DestType.getNonReferenceType() 6241 << Args[0]->getType() 6242 << Args[0]->getSourceRange(); 6243 break; 6244 6245 case FK_RValueReferenceBindingToLValue: 6246 S.Diag(Kind.getLocation(), diag::err_lvalue_to_rvalue_ref) 6247 << DestType.getNonReferenceType() << Args[0]->getType() 6248 << Args[0]->getSourceRange(); 6249 break; 6250 6251 case FK_ReferenceInitDropsQualifiers: 6252 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals) 6253 << DestType.getNonReferenceType() 6254 << Args[0]->getType() 6255 << Args[0]->getSourceRange(); 6256 break; 6257 6258 case FK_ReferenceInitFailed: 6259 S.Diag(Kind.getLocation(), diag::err_reference_bind_failed) 6260 << DestType.getNonReferenceType() 6261 << Args[0]->isLValue() 6262 << Args[0]->getType() 6263 << Args[0]->getSourceRange(); 6264 emitBadConversionNotes(S, Entity, Args[0]); 6265 break; 6266 6267 case FK_ConversionFailed: { 6268 QualType FromType = Args[0]->getType(); 6269 PartialDiagnostic PDiag = S.PDiag(diag::err_init_conversion_failed) 6270 << (int)Entity.getKind() 6271 << DestType 6272 << Args[0]->isLValue() 6273 << FromType 6274 << Args[0]->getSourceRange(); 6275 S.HandleFunctionTypeMismatch(PDiag, FromType, DestType); 6276 S.Diag(Kind.getLocation(), PDiag); 6277 emitBadConversionNotes(S, Entity, Args[0]); 6278 break; 6279 } 6280 6281 case FK_ConversionFromPropertyFailed: 6282 // No-op. This error has already been reported. 6283 break; 6284 6285 case FK_TooManyInitsForScalar: { 6286 SourceRange R; 6287 6288 if (InitListExpr *InitList = dyn_cast<InitListExpr>(Args[0])) 6289 R = SourceRange(InitList->getInit(0)->getLocEnd(), 6290 InitList->getLocEnd()); 6291 else 6292 R = SourceRange(Args.front()->getLocEnd(), Args.back()->getLocEnd()); 6293 6294 R.setBegin(S.PP.getLocForEndOfToken(R.getBegin())); 6295 if (Kind.isCStyleOrFunctionalCast()) 6296 S.Diag(Kind.getLocation(), diag::err_builtin_func_cast_more_than_one_arg) 6297 << R; 6298 else 6299 S.Diag(Kind.getLocation(), diag::err_excess_initializers) 6300 << /*scalar=*/2 << R; 6301 break; 6302 } 6303 6304 case FK_ReferenceBindingToInitList: 6305 S.Diag(Kind.getLocation(), diag::err_reference_bind_init_list) 6306 << DestType.getNonReferenceType() << Args[0]->getSourceRange(); 6307 break; 6308 6309 case FK_InitListBadDestinationType: 6310 S.Diag(Kind.getLocation(), diag::err_init_list_bad_dest_type) 6311 << (DestType->isRecordType()) << DestType << Args[0]->getSourceRange(); 6312 break; 6313 6314 case FK_ListConstructorOverloadFailed: 6315 case FK_ConstructorOverloadFailed: { 6316 SourceRange ArgsRange; 6317 if (Args.size()) 6318 ArgsRange = SourceRange(Args.front()->getLocStart(), 6319 Args.back()->getLocEnd()); 6320 6321 if (Failure == FK_ListConstructorOverloadFailed) { 6322 assert(Args.size() == 1 && "List construction from other than 1 argument."); 6323 InitListExpr *InitList = cast<InitListExpr>(Args[0]); 6324 Args = MultiExprArg(InitList->getInits(), InitList->getNumInits()); 6325 } 6326 6327 // FIXME: Using "DestType" for the entity we're printing is probably 6328 // bad. 6329 switch (FailedOverloadResult) { 6330 case OR_Ambiguous: 6331 S.Diag(Kind.getLocation(), diag::err_ovl_ambiguous_init) 6332 << DestType << ArgsRange; 6333 FailedCandidateSet.NoteCandidates(S, OCD_ViableCandidates, Args); 6334 break; 6335 6336 case OR_No_Viable_Function: 6337 if (Kind.getKind() == InitializationKind::IK_Default && 6338 (Entity.getKind() == InitializedEntity::EK_Base || 6339 Entity.getKind() == InitializedEntity::EK_Member) && 6340 isa<CXXConstructorDecl>(S.CurContext)) { 6341 // This is implicit default initialization of a member or 6342 // base within a constructor. If no viable function was 6343 // found, notify the user that she needs to explicitly 6344 // initialize this base/member. 6345 CXXConstructorDecl *Constructor 6346 = cast<CXXConstructorDecl>(S.CurContext); 6347 if (Entity.getKind() == InitializedEntity::EK_Base) { 6348 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor) 6349 << (Constructor->getInheritedConstructor() ? 2 : 6350 Constructor->isImplicit() ? 1 : 0) 6351 << S.Context.getTypeDeclType(Constructor->getParent()) 6352 << /*base=*/0 6353 << Entity.getType(); 6354 6355 RecordDecl *BaseDecl 6356 = Entity.getBaseSpecifier()->getType()->getAs<RecordType>() 6357 ->getDecl(); 6358 S.Diag(BaseDecl->getLocation(), diag::note_previous_decl) 6359 << S.Context.getTagDeclType(BaseDecl); 6360 } else { 6361 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor) 6362 << (Constructor->getInheritedConstructor() ? 2 : 6363 Constructor->isImplicit() ? 1 : 0) 6364 << S.Context.getTypeDeclType(Constructor->getParent()) 6365 << /*member=*/1 6366 << Entity.getName(); 6367 S.Diag(Entity.getDecl()->getLocation(), diag::note_field_decl); 6368 6369 if (const RecordType *Record 6370 = Entity.getType()->getAs<RecordType>()) 6371 S.Diag(Record->getDecl()->getLocation(), 6372 diag::note_previous_decl) 6373 << S.Context.getTagDeclType(Record->getDecl()); 6374 } 6375 break; 6376 } 6377 6378 S.Diag(Kind.getLocation(), diag::err_ovl_no_viable_function_in_init) 6379 << DestType << ArgsRange; 6380 FailedCandidateSet.NoteCandidates(S, OCD_AllCandidates, Args); 6381 break; 6382 6383 case OR_Deleted: { 6384 OverloadCandidateSet::iterator Best; 6385 OverloadingResult Ovl 6386 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best); 6387 if (Ovl != OR_Deleted) { 6388 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init) 6389 << true << DestType << ArgsRange; 6390 llvm_unreachable("Inconsistent overload resolution?"); 6391 break; 6392 } 6393 6394 // If this is a defaulted or implicitly-declared function, then 6395 // it was implicitly deleted. Make it clear that the deletion was 6396 // implicit. 6397 if (S.isImplicitlyDeleted(Best->Function)) 6398 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_special_init) 6399 << S.getSpecialMember(cast<CXXMethodDecl>(Best->Function)) 6400 << DestType << ArgsRange; 6401 else 6402 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init) 6403 << true << DestType << ArgsRange; 6404 6405 S.NoteDeletedFunction(Best->Function); 6406 break; 6407 } 6408 6409 case OR_Success: 6410 llvm_unreachable("Conversion did not fail!"); 6411 } 6412 } 6413 break; 6414 6415 case FK_DefaultInitOfConst: 6416 if (Entity.getKind() == InitializedEntity::EK_Member && 6417 isa<CXXConstructorDecl>(S.CurContext)) { 6418 // This is implicit default-initialization of a const member in 6419 // a constructor. Complain that it needs to be explicitly 6420 // initialized. 6421 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(S.CurContext); 6422 S.Diag(Kind.getLocation(), diag::err_uninitialized_member_in_ctor) 6423 << (Constructor->getInheritedConstructor() ? 2 : 6424 Constructor->isImplicit() ? 1 : 0) 6425 << S.Context.getTypeDeclType(Constructor->getParent()) 6426 << /*const=*/1 6427 << Entity.getName(); 6428 S.Diag(Entity.getDecl()->getLocation(), diag::note_previous_decl) 6429 << Entity.getName(); 6430 } else { 6431 S.Diag(Kind.getLocation(), diag::err_default_init_const) 6432 << DestType << (bool)DestType->getAs<RecordType>(); 6433 } 6434 break; 6435 6436 case FK_Incomplete: 6437 S.RequireCompleteType(Kind.getLocation(), FailedIncompleteType, 6438 diag::err_init_incomplete_type); 6439 break; 6440 6441 case FK_ListInitializationFailed: { 6442 // Run the init list checker again to emit diagnostics. 6443 InitListExpr* InitList = cast<InitListExpr>(Args[0]); 6444 QualType DestType = Entity.getType(); 6445 InitListChecker DiagnoseInitList(S, Entity, InitList, 6446 DestType, /*VerifyOnly=*/false); 6447 assert(DiagnoseInitList.HadError() && 6448 "Inconsistent init list check result."); 6449 break; 6450 } 6451 6452 case FK_PlaceholderType: { 6453 // FIXME: Already diagnosed! 6454 break; 6455 } 6456 6457 case FK_InitListElementCopyFailure: { 6458 // Try to perform all copies again. 6459 InitListExpr* InitList = cast<InitListExpr>(Args[0]); 6460 unsigned NumInits = InitList->getNumInits(); 6461 QualType DestType = Entity.getType(); 6462 QualType E; 6463 bool Success = S.isStdInitializerList(DestType.getNonReferenceType(), &E); 6464 (void)Success; 6465 assert(Success && "Where did the std::initializer_list go?"); 6466 InitializedEntity HiddenArray = InitializedEntity::InitializeTemporary( 6467 S.Context.getConstantArrayType(E, 6468 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()), 6469 NumInits), 6470 ArrayType::Normal, 0)); 6471 InitializedEntity Element = InitializedEntity::InitializeElement(S.Context, 6472 0, HiddenArray); 6473 // Show at most 3 errors. Otherwise, you'd get a lot of errors for errors 6474 // where the init list type is wrong, e.g. 6475 // std::initializer_list<void*> list = { 1, 2, 3, 4, 5, 6, 7, 8 }; 6476 // FIXME: Emit a note if we hit the limit? 6477 int ErrorCount = 0; 6478 for (unsigned i = 0; i < NumInits && ErrorCount < 3; ++i) { 6479 Element.setElementIndex(i); 6480 ExprResult Init = S.Owned(InitList->getInit(i)); 6481 if (S.PerformCopyInitialization(Element, Init.get()->getExprLoc(), Init) 6482 .isInvalid()) 6483 ++ErrorCount; 6484 } 6485 break; 6486 } 6487 6488 case FK_ExplicitConstructor: { 6489 S.Diag(Kind.getLocation(), diag::err_selected_explicit_constructor) 6490 << Args[0]->getSourceRange(); 6491 OverloadCandidateSet::iterator Best; 6492 OverloadingResult Ovl 6493 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best); 6494 (void)Ovl; 6495 assert(Ovl == OR_Success && "Inconsistent overload resolution"); 6496 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function); 6497 S.Diag(CtorDecl->getLocation(), diag::note_constructor_declared_here); 6498 break; 6499 } 6500 } 6501 6502 PrintInitLocationNote(S, Entity); 6503 return true; 6504} 6505 6506void InitializationSequence::dump(raw_ostream &OS) const { 6507 switch (SequenceKind) { 6508 case FailedSequence: { 6509 OS << "Failed sequence: "; 6510 switch (Failure) { 6511 case FK_TooManyInitsForReference: 6512 OS << "too many initializers for reference"; 6513 break; 6514 6515 case FK_ArrayNeedsInitList: 6516 OS << "array requires initializer list"; 6517 break; 6518 6519 case FK_ArrayNeedsInitListOrStringLiteral: 6520 OS << "array requires initializer list or string literal"; 6521 break; 6522 6523 case FK_ArrayNeedsInitListOrWideStringLiteral: 6524 OS << "array requires initializer list or wide string literal"; 6525 break; 6526 6527 case FK_NarrowStringIntoWideCharArray: 6528 OS << "narrow string into wide char array"; 6529 break; 6530 6531 case FK_WideStringIntoCharArray: 6532 OS << "wide string into char array"; 6533 break; 6534 6535 case FK_IncompatWideStringIntoWideChar: 6536 OS << "incompatible wide string into wide char array"; 6537 break; 6538 6539 case FK_ArrayTypeMismatch: 6540 OS << "array type mismatch"; 6541 break; 6542 6543 case FK_NonConstantArrayInit: 6544 OS << "non-constant array initializer"; 6545 break; 6546 6547 case FK_AddressOfOverloadFailed: 6548 OS << "address of overloaded function failed"; 6549 break; 6550 6551 case FK_ReferenceInitOverloadFailed: 6552 OS << "overload resolution for reference initialization failed"; 6553 break; 6554 6555 case FK_NonConstLValueReferenceBindingToTemporary: 6556 OS << "non-const lvalue reference bound to temporary"; 6557 break; 6558 6559 case FK_NonConstLValueReferenceBindingToUnrelated: 6560 OS << "non-const lvalue reference bound to unrelated type"; 6561 break; 6562 6563 case FK_RValueReferenceBindingToLValue: 6564 OS << "rvalue reference bound to an lvalue"; 6565 break; 6566 6567 case FK_ReferenceInitDropsQualifiers: 6568 OS << "reference initialization drops qualifiers"; 6569 break; 6570 6571 case FK_ReferenceInitFailed: 6572 OS << "reference initialization failed"; 6573 break; 6574 6575 case FK_ConversionFailed: 6576 OS << "conversion failed"; 6577 break; 6578 6579 case FK_ConversionFromPropertyFailed: 6580 OS << "conversion from property failed"; 6581 break; 6582 6583 case FK_TooManyInitsForScalar: 6584 OS << "too many initializers for scalar"; 6585 break; 6586 6587 case FK_ReferenceBindingToInitList: 6588 OS << "referencing binding to initializer list"; 6589 break; 6590 6591 case FK_InitListBadDestinationType: 6592 OS << "initializer list for non-aggregate, non-scalar type"; 6593 break; 6594 6595 case FK_UserConversionOverloadFailed: 6596 OS << "overloading failed for user-defined conversion"; 6597 break; 6598 6599 case FK_ConstructorOverloadFailed: 6600 OS << "constructor overloading failed"; 6601 break; 6602 6603 case FK_DefaultInitOfConst: 6604 OS << "default initialization of a const variable"; 6605 break; 6606 6607 case FK_Incomplete: 6608 OS << "initialization of incomplete type"; 6609 break; 6610 6611 case FK_ListInitializationFailed: 6612 OS << "list initialization checker failure"; 6613 break; 6614 6615 case FK_VariableLengthArrayHasInitializer: 6616 OS << "variable length array has an initializer"; 6617 break; 6618 6619 case FK_PlaceholderType: 6620 OS << "initializer expression isn't contextually valid"; 6621 break; 6622 6623 case FK_ListConstructorOverloadFailed: 6624 OS << "list constructor overloading failed"; 6625 break; 6626 6627 case FK_InitListElementCopyFailure: 6628 OS << "copy construction of initializer list element failed"; 6629 break; 6630 6631 case FK_ExplicitConstructor: 6632 OS << "list copy initialization chose explicit constructor"; 6633 break; 6634 } 6635 OS << '\n'; 6636 return; 6637 } 6638 6639 case DependentSequence: 6640 OS << "Dependent sequence\n"; 6641 return; 6642 6643 case NormalSequence: 6644 OS << "Normal sequence: "; 6645 break; 6646 } 6647 6648 for (step_iterator S = step_begin(), SEnd = step_end(); S != SEnd; ++S) { 6649 if (S != step_begin()) { 6650 OS << " -> "; 6651 } 6652 6653 switch (S->Kind) { 6654 case SK_ResolveAddressOfOverloadedFunction: 6655 OS << "resolve address of overloaded function"; 6656 break; 6657 6658 case SK_CastDerivedToBaseRValue: 6659 OS << "derived-to-base case (rvalue" << S->Type.getAsString() << ")"; 6660 break; 6661 6662 case SK_CastDerivedToBaseXValue: 6663 OS << "derived-to-base case (xvalue" << S->Type.getAsString() << ")"; 6664 break; 6665 6666 case SK_CastDerivedToBaseLValue: 6667 OS << "derived-to-base case (lvalue" << S->Type.getAsString() << ")"; 6668 break; 6669 6670 case SK_BindReference: 6671 OS << "bind reference to lvalue"; 6672 break; 6673 6674 case SK_BindReferenceToTemporary: 6675 OS << "bind reference to a temporary"; 6676 break; 6677 6678 case SK_ExtraneousCopyToTemporary: 6679 OS << "extraneous C++03 copy to temporary"; 6680 break; 6681 6682 case SK_UserConversion: 6683 OS << "user-defined conversion via " << *S->Function.Function; 6684 break; 6685 6686 case SK_QualificationConversionRValue: 6687 OS << "qualification conversion (rvalue)"; 6688 break; 6689 6690 case SK_QualificationConversionXValue: 6691 OS << "qualification conversion (xvalue)"; 6692 break; 6693 6694 case SK_QualificationConversionLValue: 6695 OS << "qualification conversion (lvalue)"; 6696 break; 6697 6698 case SK_LValueToRValue: 6699 OS << "load (lvalue to rvalue)"; 6700 break; 6701 6702 case SK_ConversionSequence: 6703 OS << "implicit conversion sequence ("; 6704 S->ICS->DebugPrint(); // FIXME: use OS 6705 OS << ")"; 6706 break; 6707 6708 case SK_ListInitialization: 6709 OS << "list aggregate initialization"; 6710 break; 6711 6712 case SK_ListConstructorCall: 6713 OS << "list initialization via constructor"; 6714 break; 6715 6716 case SK_UnwrapInitList: 6717 OS << "unwrap reference initializer list"; 6718 break; 6719 6720 case SK_RewrapInitList: 6721 OS << "rewrap reference initializer list"; 6722 break; 6723 6724 case SK_ConstructorInitialization: 6725 OS << "constructor initialization"; 6726 break; 6727 6728 case SK_ZeroInitialization: 6729 OS << "zero initialization"; 6730 break; 6731 6732 case SK_CAssignment: 6733 OS << "C assignment"; 6734 break; 6735 6736 case SK_StringInit: 6737 OS << "string initialization"; 6738 break; 6739 6740 case SK_ObjCObjectConversion: 6741 OS << "Objective-C object conversion"; 6742 break; 6743 6744 case SK_ArrayInit: 6745 OS << "array initialization"; 6746 break; 6747 6748 case SK_ParenthesizedArrayInit: 6749 OS << "parenthesized array initialization"; 6750 break; 6751 6752 case SK_PassByIndirectCopyRestore: 6753 OS << "pass by indirect copy and restore"; 6754 break; 6755 6756 case SK_PassByIndirectRestore: 6757 OS << "pass by indirect restore"; 6758 break; 6759 6760 case SK_ProduceObjCObject: 6761 OS << "Objective-C object retension"; 6762 break; 6763 6764 case SK_StdInitializerList: 6765 OS << "std::initializer_list from initializer list"; 6766 break; 6767 6768 case SK_OCLSamplerInit: 6769 OS << "OpenCL sampler_t from integer constant"; 6770 break; 6771 6772 case SK_OCLZeroEvent: 6773 OS << "OpenCL event_t from zero"; 6774 break; 6775 } 6776 6777 OS << " [" << S->Type.getAsString() << ']'; 6778 } 6779 6780 OS << '\n'; 6781} 6782 6783void InitializationSequence::dump() const { 6784 dump(llvm::errs()); 6785} 6786 6787static void DiagnoseNarrowingInInitList(Sema &S, InitializationSequence &Seq, 6788 QualType EntityType, 6789 const Expr *PreInit, 6790 const Expr *PostInit) { 6791 if (Seq.step_begin() == Seq.step_end() || PreInit->isValueDependent()) 6792 return; 6793 6794 // A narrowing conversion can only appear as the final implicit conversion in 6795 // an initialization sequence. 6796 const InitializationSequence::Step &LastStep = Seq.step_end()[-1]; 6797 if (LastStep.Kind != InitializationSequence::SK_ConversionSequence) 6798 return; 6799 6800 const ImplicitConversionSequence &ICS = *LastStep.ICS; 6801 const StandardConversionSequence *SCS = 0; 6802 switch (ICS.getKind()) { 6803 case ImplicitConversionSequence::StandardConversion: 6804 SCS = &ICS.Standard; 6805 break; 6806 case ImplicitConversionSequence::UserDefinedConversion: 6807 SCS = &ICS.UserDefined.After; 6808 break; 6809 case ImplicitConversionSequence::AmbiguousConversion: 6810 case ImplicitConversionSequence::EllipsisConversion: 6811 case ImplicitConversionSequence::BadConversion: 6812 return; 6813 } 6814 6815 // Determine the type prior to the narrowing conversion. If a conversion 6816 // operator was used, this may be different from both the type of the entity 6817 // and of the pre-initialization expression. 6818 QualType PreNarrowingType = PreInit->getType(); 6819 if (Seq.step_begin() + 1 != Seq.step_end()) 6820 PreNarrowingType = Seq.step_end()[-2].Type; 6821 6822 // C++11 [dcl.init.list]p7: Check whether this is a narrowing conversion. 6823 APValue ConstantValue; 6824 QualType ConstantType; 6825 switch (SCS->getNarrowingKind(S.Context, PostInit, ConstantValue, 6826 ConstantType)) { 6827 case NK_Not_Narrowing: 6828 // No narrowing occurred. 6829 return; 6830 6831 case NK_Type_Narrowing: 6832 // This was a floating-to-integer conversion, which is always considered a 6833 // narrowing conversion even if the value is a constant and can be 6834 // represented exactly as an integer. 6835 S.Diag(PostInit->getLocStart(), 6836 S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11? 6837 diag::warn_init_list_type_narrowing 6838 : S.isSFINAEContext()? 6839 diag::err_init_list_type_narrowing_sfinae 6840 : diag::err_init_list_type_narrowing) 6841 << PostInit->getSourceRange() 6842 << PreNarrowingType.getLocalUnqualifiedType() 6843 << EntityType.getLocalUnqualifiedType(); 6844 break; 6845 6846 case NK_Constant_Narrowing: 6847 // A constant value was narrowed. 6848 S.Diag(PostInit->getLocStart(), 6849 S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11? 6850 diag::warn_init_list_constant_narrowing 6851 : S.isSFINAEContext()? 6852 diag::err_init_list_constant_narrowing_sfinae 6853 : diag::err_init_list_constant_narrowing) 6854 << PostInit->getSourceRange() 6855 << ConstantValue.getAsString(S.getASTContext(), ConstantType) 6856 << EntityType.getLocalUnqualifiedType(); 6857 break; 6858 6859 case NK_Variable_Narrowing: 6860 // A variable's value may have been narrowed. 6861 S.Diag(PostInit->getLocStart(), 6862 S.getLangOpts().MicrosoftExt || !S.getLangOpts().CPlusPlus11? 6863 diag::warn_init_list_variable_narrowing 6864 : S.isSFINAEContext()? 6865 diag::err_init_list_variable_narrowing_sfinae 6866 : diag::err_init_list_variable_narrowing) 6867 << PostInit->getSourceRange() 6868 << PreNarrowingType.getLocalUnqualifiedType() 6869 << EntityType.getLocalUnqualifiedType(); 6870 break; 6871 } 6872 6873 SmallString<128> StaticCast; 6874 llvm::raw_svector_ostream OS(StaticCast); 6875 OS << "static_cast<"; 6876 if (const TypedefType *TT = EntityType->getAs<TypedefType>()) { 6877 // It's important to use the typedef's name if there is one so that the 6878 // fixit doesn't break code using types like int64_t. 6879 // 6880 // FIXME: This will break if the typedef requires qualification. But 6881 // getQualifiedNameAsString() includes non-machine-parsable components. 6882 OS << *TT->getDecl(); 6883 } else if (const BuiltinType *BT = EntityType->getAs<BuiltinType>()) 6884 OS << BT->getName(S.getLangOpts()); 6885 else { 6886 // Oops, we didn't find the actual type of the variable. Don't emit a fixit 6887 // with a broken cast. 6888 return; 6889 } 6890 OS << ">("; 6891 S.Diag(PostInit->getLocStart(), diag::note_init_list_narrowing_override) 6892 << PostInit->getSourceRange() 6893 << FixItHint::CreateInsertion(PostInit->getLocStart(), OS.str()) 6894 << FixItHint::CreateInsertion( 6895 S.getPreprocessor().getLocForEndOfToken(PostInit->getLocEnd()), ")"); 6896} 6897 6898//===----------------------------------------------------------------------===// 6899// Initialization helper functions 6900//===----------------------------------------------------------------------===// 6901bool 6902Sema::CanPerformCopyInitialization(const InitializedEntity &Entity, 6903 ExprResult Init) { 6904 if (Init.isInvalid()) 6905 return false; 6906 6907 Expr *InitE = Init.get(); 6908 assert(InitE && "No initialization expression"); 6909 6910 InitializationKind Kind 6911 = InitializationKind::CreateCopy(InitE->getLocStart(), SourceLocation()); 6912 InitializationSequence Seq(*this, Entity, Kind, InitE); 6913 return !Seq.Failed(); 6914} 6915 6916ExprResult 6917Sema::PerformCopyInitialization(const InitializedEntity &Entity, 6918 SourceLocation EqualLoc, 6919 ExprResult Init, 6920 bool TopLevelOfInitList, 6921 bool AllowExplicit) { 6922 if (Init.isInvalid()) 6923 return ExprError(); 6924 6925 Expr *InitE = Init.get(); 6926 assert(InitE && "No initialization expression?"); 6927 6928 if (EqualLoc.isInvalid()) 6929 EqualLoc = InitE->getLocStart(); 6930 6931 InitializationKind Kind = InitializationKind::CreateCopy(InitE->getLocStart(), 6932 EqualLoc, 6933 AllowExplicit); 6934 InitializationSequence Seq(*this, Entity, Kind, InitE); 6935 Init.release(); 6936 6937 ExprResult Result = Seq.Perform(*this, Entity, Kind, InitE); 6938 6939 if (!Result.isInvalid() && TopLevelOfInitList) 6940 DiagnoseNarrowingInInitList(*this, Seq, Entity.getType(), 6941 InitE, Result.get()); 6942 6943 return Result; 6944} 6945