SemaInit.cpp revision 2835745a451002798fed9800aeb19277f6a8fcb3
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/Designator.h" 15#include "clang/Sema/Initialization.h" 16#include "clang/Sema/Lookup.h" 17#include "clang/Sema/SemaInternal.h" 18#include "clang/Lex/Preprocessor.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/DeclObjC.h" 21#include "clang/AST/ExprCXX.h" 22#include "clang/AST/ExprObjC.h" 23#include "clang/AST/TypeLoc.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 35static Expr *IsStringInit(Expr *Init, const ArrayType *AT, 36 ASTContext &Context) { 37 if (!isa<ConstantArrayType>(AT) && !isa<IncompleteArrayType>(AT)) 38 return 0; 39 40 // See if this is a string literal or @encode. 41 Init = Init->IgnoreParens(); 42 43 // Handle @encode, which is a narrow string. 44 if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType()) 45 return Init; 46 47 // Otherwise we can only handle string literals. 48 StringLiteral *SL = dyn_cast<StringLiteral>(Init); 49 if (SL == 0) return 0; 50 51 QualType ElemTy = Context.getCanonicalType(AT->getElementType()); 52 53 switch (SL->getKind()) { 54 case StringLiteral::Ascii: 55 case StringLiteral::UTF8: 56 // char array can be initialized with a narrow string. 57 // Only allow char x[] = "foo"; not char x[] = L"foo"; 58 return ElemTy->isCharType() ? Init : 0; 59 case StringLiteral::UTF16: 60 return ElemTy->isChar16Type() ? Init : 0; 61 case StringLiteral::UTF32: 62 return ElemTy->isChar32Type() ? Init : 0; 63 case StringLiteral::Wide: 64 // wchar_t array can be initialized with a wide string: C99 6.7.8p15 (with 65 // correction from DR343): "An array with element type compatible with a 66 // qualified or unqualified version of wchar_t may be initialized by a wide 67 // string literal, optionally enclosed in braces." 68 if (Context.typesAreCompatible(Context.getWCharType(), 69 ElemTy.getUnqualifiedType())) 70 return Init; 71 72 return 0; 73 } 74 75 llvm_unreachable("missed a StringLiteral kind?"); 76} 77 78static Expr *IsStringInit(Expr *init, QualType declType, ASTContext &Context) { 79 const ArrayType *arrayType = Context.getAsArrayType(declType); 80 if (!arrayType) return 0; 81 82 return IsStringInit(init, arrayType, Context); 83} 84 85static void CheckStringInit(Expr *Str, QualType &DeclT, const ArrayType *AT, 86 Sema &S) { 87 // Get the length of the string as parsed. 88 uint64_t StrLength = 89 cast<ConstantArrayType>(Str->getType())->getSize().getZExtValue(); 90 91 92 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 93 // C99 6.7.8p14. We have an array of character type with unknown size 94 // being initialized to a string literal. 95 llvm::APSInt ConstVal(32); 96 ConstVal = StrLength; 97 // Return a new array type (C99 6.7.8p22). 98 DeclT = S.Context.getConstantArrayType(IAT->getElementType(), 99 ConstVal, 100 ArrayType::Normal, 0); 101 return; 102 } 103 104 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 105 106 // We have an array of character type with known size. However, 107 // the size may be smaller or larger than the string we are initializing. 108 // FIXME: Avoid truncation for 64-bit length strings. 109 if (S.getLangOptions().CPlusPlus) { 110 if (StringLiteral *SL = dyn_cast<StringLiteral>(Str)) { 111 // For Pascal strings it's OK to strip off the terminating null character, 112 // so the example below is valid: 113 // 114 // unsigned char a[2] = "\pa"; 115 if (SL->isPascal()) 116 StrLength--; 117 } 118 119 // [dcl.init.string]p2 120 if (StrLength > CAT->getSize().getZExtValue()) 121 S.Diag(Str->getSourceRange().getBegin(), 122 diag::err_initializer_string_for_char_array_too_long) 123 << Str->getSourceRange(); 124 } else { 125 // C99 6.7.8p14. 126 if (StrLength-1 > CAT->getSize().getZExtValue()) 127 S.Diag(Str->getSourceRange().getBegin(), 128 diag::warn_initializer_string_for_char_array_too_long) 129 << Str->getSourceRange(); 130 } 131 132 // Set the type to the actual size that we are initializing. If we have 133 // something like: 134 // char x[1] = "foo"; 135 // then this will set the string literal's type to char[1]. 136 Str->setType(DeclT); 137} 138 139//===----------------------------------------------------------------------===// 140// Semantic checking for initializer lists. 141//===----------------------------------------------------------------------===// 142 143/// @brief Semantic checking for initializer lists. 144/// 145/// The InitListChecker class contains a set of routines that each 146/// handle the initialization of a certain kind of entity, e.g., 147/// arrays, vectors, struct/union types, scalars, etc. The 148/// InitListChecker itself performs a recursive walk of the subobject 149/// structure of the type to be initialized, while stepping through 150/// the initializer list one element at a time. The IList and Index 151/// parameters to each of the Check* routines contain the active 152/// (syntactic) initializer list and the index into that initializer 153/// list that represents the current initializer. Each routine is 154/// responsible for moving that Index forward as it consumes elements. 155/// 156/// Each Check* routine also has a StructuredList/StructuredIndex 157/// arguments, which contains the current "structured" (semantic) 158/// initializer list and the index into that initializer list where we 159/// are copying initializers as we map them over to the semantic 160/// list. Once we have completed our recursive walk of the subobject 161/// structure, we will have constructed a full semantic initializer 162/// list. 163/// 164/// C99 designators cause changes in the initializer list traversal, 165/// because they make the initialization "jump" into a specific 166/// subobject and then continue the initialization from that 167/// point. CheckDesignatedInitializer() recursively steps into the 168/// designated subobject and manages backing out the recursion to 169/// initialize the subobjects after the one designated. 170namespace { 171class InitListChecker { 172 Sema &SemaRef; 173 bool hadError; 174 bool VerifyOnly; // no diagnostics, no structure building 175 bool AllowBraceElision; 176 llvm::DenseMap<InitListExpr *, InitListExpr *> SyntacticToSemantic; 177 InitListExpr *FullyStructuredList; 178 179 void CheckImplicitInitList(const InitializedEntity &Entity, 180 InitListExpr *ParentIList, QualType T, 181 unsigned &Index, InitListExpr *StructuredList, 182 unsigned &StructuredIndex); 183 void CheckExplicitInitList(const InitializedEntity &Entity, 184 InitListExpr *IList, QualType &T, 185 unsigned &Index, InitListExpr *StructuredList, 186 unsigned &StructuredIndex, 187 bool TopLevelObject = false); 188 void CheckListElementTypes(const InitializedEntity &Entity, 189 InitListExpr *IList, QualType &DeclType, 190 bool SubobjectIsDesignatorContext, 191 unsigned &Index, 192 InitListExpr *StructuredList, 193 unsigned &StructuredIndex, 194 bool TopLevelObject = false); 195 void CheckSubElementType(const InitializedEntity &Entity, 196 InitListExpr *IList, QualType ElemType, 197 unsigned &Index, 198 InitListExpr *StructuredList, 199 unsigned &StructuredIndex); 200 void CheckComplexType(const InitializedEntity &Entity, 201 InitListExpr *IList, QualType DeclType, 202 unsigned &Index, 203 InitListExpr *StructuredList, 204 unsigned &StructuredIndex); 205 void CheckScalarType(const InitializedEntity &Entity, 206 InitListExpr *IList, QualType DeclType, 207 unsigned &Index, 208 InitListExpr *StructuredList, 209 unsigned &StructuredIndex); 210 void CheckReferenceType(const InitializedEntity &Entity, 211 InitListExpr *IList, QualType DeclType, 212 unsigned &Index, 213 InitListExpr *StructuredList, 214 unsigned &StructuredIndex); 215 void CheckVectorType(const InitializedEntity &Entity, 216 InitListExpr *IList, QualType DeclType, unsigned &Index, 217 InitListExpr *StructuredList, 218 unsigned &StructuredIndex); 219 void CheckStructUnionTypes(const InitializedEntity &Entity, 220 InitListExpr *IList, QualType DeclType, 221 RecordDecl::field_iterator Field, 222 bool SubobjectIsDesignatorContext, unsigned &Index, 223 InitListExpr *StructuredList, 224 unsigned &StructuredIndex, 225 bool TopLevelObject = false); 226 void CheckArrayType(const InitializedEntity &Entity, 227 InitListExpr *IList, QualType &DeclType, 228 llvm::APSInt elementIndex, 229 bool SubobjectIsDesignatorContext, unsigned &Index, 230 InitListExpr *StructuredList, 231 unsigned &StructuredIndex); 232 bool CheckDesignatedInitializer(const InitializedEntity &Entity, 233 InitListExpr *IList, DesignatedInitExpr *DIE, 234 unsigned DesigIdx, 235 QualType &CurrentObjectType, 236 RecordDecl::field_iterator *NextField, 237 llvm::APSInt *NextElementIndex, 238 unsigned &Index, 239 InitListExpr *StructuredList, 240 unsigned &StructuredIndex, 241 bool FinishSubobjectInit, 242 bool TopLevelObject); 243 InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index, 244 QualType CurrentObjectType, 245 InitListExpr *StructuredList, 246 unsigned StructuredIndex, 247 SourceRange InitRange); 248 void UpdateStructuredListElement(InitListExpr *StructuredList, 249 unsigned &StructuredIndex, 250 Expr *expr); 251 int numArrayElements(QualType DeclType); 252 int numStructUnionElements(QualType DeclType); 253 254 void FillInValueInitForField(unsigned Init, FieldDecl *Field, 255 const InitializedEntity &ParentEntity, 256 InitListExpr *ILE, bool &RequiresSecondPass); 257 void FillInValueInitializations(const InitializedEntity &Entity, 258 InitListExpr *ILE, bool &RequiresSecondPass); 259 bool CheckFlexibleArrayInit(const InitializedEntity &Entity, 260 Expr *InitExpr, FieldDecl *Field, 261 bool TopLevelObject); 262 void CheckValueInitializable(const InitializedEntity &Entity); 263 264public: 265 InitListChecker(Sema &S, const InitializedEntity &Entity, 266 InitListExpr *IL, QualType &T, bool VerifyOnly, 267 bool AllowBraceElision); 268 bool HadError() { return hadError; } 269 270 // @brief Retrieves the fully-structured initializer list used for 271 // semantic analysis and code generation. 272 InitListExpr *getFullyStructuredList() const { return FullyStructuredList; } 273}; 274} // end anonymous namespace 275 276void InitListChecker::CheckValueInitializable(const InitializedEntity &Entity) { 277 assert(VerifyOnly && 278 "CheckValueInitializable is only inteded for verification mode."); 279 280 SourceLocation Loc; 281 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, 282 true); 283 InitializationSequence InitSeq(SemaRef, Entity, Kind, 0, 0); 284 if (InitSeq.Failed()) 285 hadError = true; 286} 287 288void InitListChecker::FillInValueInitForField(unsigned Init, FieldDecl *Field, 289 const InitializedEntity &ParentEntity, 290 InitListExpr *ILE, 291 bool &RequiresSecondPass) { 292 SourceLocation Loc = ILE->getSourceRange().getBegin(); 293 unsigned NumInits = ILE->getNumInits(); 294 InitializedEntity MemberEntity 295 = InitializedEntity::InitializeMember(Field, &ParentEntity); 296 if (Init >= NumInits || !ILE->getInit(Init)) { 297 // FIXME: We probably don't need to handle references 298 // specially here, since value-initialization of references is 299 // handled in InitializationSequence. 300 if (Field->getType()->isReferenceType()) { 301 // C++ [dcl.init.aggr]p9: 302 // If an incomplete or empty initializer-list leaves a 303 // member of reference type uninitialized, the program is 304 // ill-formed. 305 SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized) 306 << Field->getType() 307 << ILE->getSyntacticForm()->getSourceRange(); 308 SemaRef.Diag(Field->getLocation(), 309 diag::note_uninit_reference_member); 310 hadError = true; 311 return; 312 } 313 314 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, 315 true); 316 InitializationSequence InitSeq(SemaRef, MemberEntity, Kind, 0, 0); 317 if (!InitSeq) { 318 InitSeq.Diagnose(SemaRef, MemberEntity, Kind, 0, 0); 319 hadError = true; 320 return; 321 } 322 323 ExprResult MemberInit 324 = InitSeq.Perform(SemaRef, MemberEntity, Kind, MultiExprArg()); 325 if (MemberInit.isInvalid()) { 326 hadError = true; 327 return; 328 } 329 330 if (hadError) { 331 // Do nothing 332 } else if (Init < NumInits) { 333 ILE->setInit(Init, MemberInit.takeAs<Expr>()); 334 } else if (InitSeq.isConstructorInitialization()) { 335 // Value-initialization requires a constructor call, so 336 // extend the initializer list to include the constructor 337 // call and make a note that we'll need to take another pass 338 // through the initializer list. 339 ILE->updateInit(SemaRef.Context, Init, MemberInit.takeAs<Expr>()); 340 RequiresSecondPass = true; 341 } 342 } else if (InitListExpr *InnerILE 343 = dyn_cast<InitListExpr>(ILE->getInit(Init))) 344 FillInValueInitializations(MemberEntity, InnerILE, 345 RequiresSecondPass); 346} 347 348/// Recursively replaces NULL values within the given initializer list 349/// with expressions that perform value-initialization of the 350/// appropriate type. 351void 352InitListChecker::FillInValueInitializations(const InitializedEntity &Entity, 353 InitListExpr *ILE, 354 bool &RequiresSecondPass) { 355 assert((ILE->getType() != SemaRef.Context.VoidTy) && 356 "Should not have void type"); 357 SourceLocation Loc = ILE->getSourceRange().getBegin(); 358 if (ILE->getSyntacticForm()) 359 Loc = ILE->getSyntacticForm()->getSourceRange().getBegin(); 360 361 if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) { 362 if (RType->getDecl()->isUnion() && 363 ILE->getInitializedFieldInUnion()) 364 FillInValueInitForField(0, ILE->getInitializedFieldInUnion(), 365 Entity, ILE, RequiresSecondPass); 366 else { 367 unsigned Init = 0; 368 for (RecordDecl::field_iterator 369 Field = RType->getDecl()->field_begin(), 370 FieldEnd = RType->getDecl()->field_end(); 371 Field != FieldEnd; ++Field) { 372 if (Field->isUnnamedBitfield()) 373 continue; 374 375 if (hadError) 376 return; 377 378 FillInValueInitForField(Init, *Field, Entity, ILE, RequiresSecondPass); 379 if (hadError) 380 return; 381 382 ++Init; 383 384 // Only look at the first initialization of a union. 385 if (RType->getDecl()->isUnion()) 386 break; 387 } 388 } 389 390 return; 391 } 392 393 QualType ElementType; 394 395 InitializedEntity ElementEntity = Entity; 396 unsigned NumInits = ILE->getNumInits(); 397 unsigned NumElements = NumInits; 398 if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) { 399 ElementType = AType->getElementType(); 400 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) 401 NumElements = CAType->getSize().getZExtValue(); 402 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context, 403 0, Entity); 404 } else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) { 405 ElementType = VType->getElementType(); 406 NumElements = VType->getNumElements(); 407 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context, 408 0, Entity); 409 } else 410 ElementType = ILE->getType(); 411 412 413 for (unsigned Init = 0; Init != NumElements; ++Init) { 414 if (hadError) 415 return; 416 417 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement || 418 ElementEntity.getKind() == InitializedEntity::EK_VectorElement) 419 ElementEntity.setElementIndex(Init); 420 421 Expr *InitExpr = (Init < NumInits ? ILE->getInit(Init) : 0); 422 if (!InitExpr && !ILE->hasArrayFiller()) { 423 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, 424 true); 425 InitializationSequence InitSeq(SemaRef, ElementEntity, Kind, 0, 0); 426 if (!InitSeq) { 427 InitSeq.Diagnose(SemaRef, ElementEntity, Kind, 0, 0); 428 hadError = true; 429 return; 430 } 431 432 ExprResult ElementInit 433 = InitSeq.Perform(SemaRef, ElementEntity, Kind, MultiExprArg()); 434 if (ElementInit.isInvalid()) { 435 hadError = true; 436 return; 437 } 438 439 if (hadError) { 440 // Do nothing 441 } else if (Init < NumInits) { 442 // For arrays, just set the expression used for value-initialization 443 // of the "holes" in the array. 444 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) 445 ILE->setArrayFiller(ElementInit.takeAs<Expr>()); 446 else 447 ILE->setInit(Init, ElementInit.takeAs<Expr>()); 448 } else { 449 // For arrays, just set the expression used for value-initialization 450 // of the rest of elements and exit. 451 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement) { 452 ILE->setArrayFiller(ElementInit.takeAs<Expr>()); 453 return; 454 } 455 456 if (InitSeq.isConstructorInitialization()) { 457 // Value-initialization requires a constructor call, so 458 // extend the initializer list to include the constructor 459 // call and make a note that we'll need to take another pass 460 // through the initializer list. 461 ILE->updateInit(SemaRef.Context, Init, ElementInit.takeAs<Expr>()); 462 RequiresSecondPass = true; 463 } 464 } 465 } else if (InitListExpr *InnerILE 466 = dyn_cast_or_null<InitListExpr>(InitExpr)) 467 FillInValueInitializations(ElementEntity, InnerILE, RequiresSecondPass); 468 } 469} 470 471 472InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity, 473 InitListExpr *IL, QualType &T, 474 bool VerifyOnly, bool AllowBraceElision) 475 : SemaRef(S), VerifyOnly(VerifyOnly), AllowBraceElision(AllowBraceElision) { 476 hadError = false; 477 478 unsigned newIndex = 0; 479 unsigned newStructuredIndex = 0; 480 FullyStructuredList 481 = getStructuredSubobjectInit(IL, newIndex, T, 0, 0, IL->getSourceRange()); 482 CheckExplicitInitList(Entity, IL, T, newIndex, 483 FullyStructuredList, newStructuredIndex, 484 /*TopLevelObject=*/true); 485 486 if (!hadError && !VerifyOnly) { 487 bool RequiresSecondPass = false; 488 FillInValueInitializations(Entity, FullyStructuredList, RequiresSecondPass); 489 if (RequiresSecondPass && !hadError) 490 FillInValueInitializations(Entity, FullyStructuredList, 491 RequiresSecondPass); 492 } 493} 494 495int InitListChecker::numArrayElements(QualType DeclType) { 496 // FIXME: use a proper constant 497 int maxElements = 0x7FFFFFFF; 498 if (const ConstantArrayType *CAT = 499 SemaRef.Context.getAsConstantArrayType(DeclType)) { 500 maxElements = static_cast<int>(CAT->getSize().getZExtValue()); 501 } 502 return maxElements; 503} 504 505int InitListChecker::numStructUnionElements(QualType DeclType) { 506 RecordDecl *structDecl = DeclType->getAs<RecordType>()->getDecl(); 507 int InitializableMembers = 0; 508 for (RecordDecl::field_iterator 509 Field = structDecl->field_begin(), 510 FieldEnd = structDecl->field_end(); 511 Field != FieldEnd; ++Field) { 512 if (!Field->isUnnamedBitfield()) 513 ++InitializableMembers; 514 } 515 if (structDecl->isUnion()) 516 return std::min(InitializableMembers, 1); 517 return InitializableMembers - structDecl->hasFlexibleArrayMember(); 518} 519 520void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity, 521 InitListExpr *ParentIList, 522 QualType T, unsigned &Index, 523 InitListExpr *StructuredList, 524 unsigned &StructuredIndex) { 525 int maxElements = 0; 526 527 if (T->isArrayType()) 528 maxElements = numArrayElements(T); 529 else if (T->isRecordType()) 530 maxElements = numStructUnionElements(T); 531 else if (T->isVectorType()) 532 maxElements = T->getAs<VectorType>()->getNumElements(); 533 else 534 llvm_unreachable("CheckImplicitInitList(): Illegal type"); 535 536 if (maxElements == 0) { 537 if (!VerifyOnly) 538 SemaRef.Diag(ParentIList->getInit(Index)->getLocStart(), 539 diag::err_implicit_empty_initializer); 540 ++Index; 541 hadError = true; 542 return; 543 } 544 545 // Build a structured initializer list corresponding to this subobject. 546 InitListExpr *StructuredSubobjectInitList 547 = getStructuredSubobjectInit(ParentIList, Index, T, StructuredList, 548 StructuredIndex, 549 SourceRange(ParentIList->getInit(Index)->getSourceRange().getBegin(), 550 ParentIList->getSourceRange().getEnd())); 551 unsigned StructuredSubobjectInitIndex = 0; 552 553 // Check the element types and build the structural subobject. 554 unsigned StartIndex = Index; 555 CheckListElementTypes(Entity, ParentIList, T, 556 /*SubobjectIsDesignatorContext=*/false, Index, 557 StructuredSubobjectInitList, 558 StructuredSubobjectInitIndex); 559 560 if (VerifyOnly) { 561 if (!AllowBraceElision && (T->isArrayType() || T->isRecordType())) 562 hadError = true; 563 } else { 564 StructuredSubobjectInitList->setType(T); 565 566 unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1); 567 // Update the structured sub-object initializer so that it's ending 568 // range corresponds with the end of the last initializer it used. 569 if (EndIndex < ParentIList->getNumInits()) { 570 SourceLocation EndLoc 571 = ParentIList->getInit(EndIndex)->getSourceRange().getEnd(); 572 StructuredSubobjectInitList->setRBraceLoc(EndLoc); 573 } 574 575 // Complain about missing braces. 576 if (T->isArrayType() || T->isRecordType()) { 577 SemaRef.Diag(StructuredSubobjectInitList->getLocStart(), 578 AllowBraceElision ? diag::warn_missing_braces : 579 diag::err_missing_braces) 580 << StructuredSubobjectInitList->getSourceRange() 581 << FixItHint::CreateInsertion( 582 StructuredSubobjectInitList->getLocStart(), "{") 583 << FixItHint::CreateInsertion( 584 SemaRef.PP.getLocForEndOfToken( 585 StructuredSubobjectInitList->getLocEnd()), 586 "}"); 587 if (!AllowBraceElision) 588 hadError = true; 589 } 590 } 591} 592 593void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity, 594 InitListExpr *IList, QualType &T, 595 unsigned &Index, 596 InitListExpr *StructuredList, 597 unsigned &StructuredIndex, 598 bool TopLevelObject) { 599 assert(IList->isExplicit() && "Illegal Implicit InitListExpr"); 600 if (!VerifyOnly) { 601 SyntacticToSemantic[IList] = StructuredList; 602 StructuredList->setSyntacticForm(IList); 603 } 604 CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true, 605 Index, StructuredList, StructuredIndex, TopLevelObject); 606 if (!VerifyOnly) { 607 QualType ExprTy = T; 608 if (!ExprTy->isArrayType()) 609 ExprTy = ExprTy.getNonLValueExprType(SemaRef.Context); 610 IList->setType(ExprTy); 611 StructuredList->setType(ExprTy); 612 } 613 if (hadError) 614 return; 615 616 if (Index < IList->getNumInits()) { 617 // We have leftover initializers 618 if (VerifyOnly) { 619 if (SemaRef.getLangOptions().CPlusPlus || 620 (SemaRef.getLangOptions().OpenCL && 621 IList->getType()->isVectorType())) { 622 hadError = true; 623 } 624 return; 625 } 626 627 if (StructuredIndex == 1 && 628 IsStringInit(StructuredList->getInit(0), T, SemaRef.Context)) { 629 unsigned DK = diag::warn_excess_initializers_in_char_array_initializer; 630 if (SemaRef.getLangOptions().CPlusPlus) { 631 DK = diag::err_excess_initializers_in_char_array_initializer; 632 hadError = true; 633 } 634 // Special-case 635 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK) 636 << IList->getInit(Index)->getSourceRange(); 637 } else if (!T->isIncompleteType()) { 638 // Don't complain for incomplete types, since we'll get an error 639 // elsewhere 640 QualType CurrentObjectType = StructuredList->getType(); 641 int initKind = 642 CurrentObjectType->isArrayType()? 0 : 643 CurrentObjectType->isVectorType()? 1 : 644 CurrentObjectType->isScalarType()? 2 : 645 CurrentObjectType->isUnionType()? 3 : 646 4; 647 648 unsigned DK = diag::warn_excess_initializers; 649 if (SemaRef.getLangOptions().CPlusPlus) { 650 DK = diag::err_excess_initializers; 651 hadError = true; 652 } 653 if (SemaRef.getLangOptions().OpenCL && initKind == 1) { 654 DK = diag::err_excess_initializers; 655 hadError = true; 656 } 657 658 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK) 659 << initKind << IList->getInit(Index)->getSourceRange(); 660 } 661 } 662 663 if (!VerifyOnly && T->isScalarType() && IList->getNumInits() == 1 && 664 !TopLevelObject) 665 SemaRef.Diag(IList->getLocStart(), diag::warn_braces_around_scalar_init) 666 << IList->getSourceRange() 667 << FixItHint::CreateRemoval(IList->getLocStart()) 668 << FixItHint::CreateRemoval(IList->getLocEnd()); 669} 670 671void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity, 672 InitListExpr *IList, 673 QualType &DeclType, 674 bool SubobjectIsDesignatorContext, 675 unsigned &Index, 676 InitListExpr *StructuredList, 677 unsigned &StructuredIndex, 678 bool TopLevelObject) { 679 if (DeclType->isAnyComplexType() && SubobjectIsDesignatorContext) { 680 // Explicitly braced initializer for complex type can be real+imaginary 681 // parts. 682 CheckComplexType(Entity, IList, DeclType, Index, 683 StructuredList, StructuredIndex); 684 } else if (DeclType->isScalarType()) { 685 CheckScalarType(Entity, IList, DeclType, Index, 686 StructuredList, StructuredIndex); 687 } else if (DeclType->isVectorType()) { 688 CheckVectorType(Entity, IList, DeclType, Index, 689 StructuredList, StructuredIndex); 690 } else if (DeclType->isAggregateType()) { 691 if (DeclType->isRecordType()) { 692 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 693 CheckStructUnionTypes(Entity, IList, DeclType, RD->field_begin(), 694 SubobjectIsDesignatorContext, Index, 695 StructuredList, StructuredIndex, 696 TopLevelObject); 697 } else if (DeclType->isArrayType()) { 698 llvm::APSInt Zero( 699 SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()), 700 false); 701 CheckArrayType(Entity, IList, DeclType, Zero, 702 SubobjectIsDesignatorContext, Index, 703 StructuredList, StructuredIndex); 704 } else 705 llvm_unreachable("Aggregate that isn't a structure or array?!"); 706 } else if (DeclType->isVoidType() || DeclType->isFunctionType()) { 707 // This type is invalid, issue a diagnostic. 708 ++Index; 709 if (!VerifyOnly) 710 SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type) 711 << DeclType; 712 hadError = true; 713 } else if (DeclType->isRecordType()) { 714 // C++ [dcl.init]p14: 715 // [...] If the class is an aggregate (8.5.1), and the initializer 716 // is a brace-enclosed list, see 8.5.1. 717 // 718 // Note: 8.5.1 is handled below; here, we diagnose the case where 719 // we have an initializer list and a destination type that is not 720 // an aggregate. 721 // FIXME: In C++0x, this is yet another form of initialization. 722 if (!VerifyOnly) 723 SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list) 724 << DeclType << IList->getSourceRange(); 725 hadError = true; 726 } else if (DeclType->isReferenceType()) { 727 CheckReferenceType(Entity, IList, DeclType, Index, 728 StructuredList, StructuredIndex); 729 } else if (DeclType->isObjCObjectType()) { 730 if (!VerifyOnly) 731 SemaRef.Diag(IList->getLocStart(), diag::err_init_objc_class) 732 << DeclType; 733 hadError = true; 734 } else { 735 if (!VerifyOnly) 736 SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type) 737 << DeclType; 738 hadError = true; 739 } 740} 741 742void InitListChecker::CheckSubElementType(const InitializedEntity &Entity, 743 InitListExpr *IList, 744 QualType ElemType, 745 unsigned &Index, 746 InitListExpr *StructuredList, 747 unsigned &StructuredIndex) { 748 Expr *expr = IList->getInit(Index); 749 if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) { 750 unsigned newIndex = 0; 751 unsigned newStructuredIndex = 0; 752 InitListExpr *newStructuredList 753 = getStructuredSubobjectInit(IList, Index, ElemType, 754 StructuredList, StructuredIndex, 755 SubInitList->getSourceRange()); 756 CheckExplicitInitList(Entity, SubInitList, ElemType, newIndex, 757 newStructuredList, newStructuredIndex); 758 ++StructuredIndex; 759 ++Index; 760 return; 761 } else if (ElemType->isScalarType()) { 762 return CheckScalarType(Entity, IList, ElemType, Index, 763 StructuredList, StructuredIndex); 764 } else if (ElemType->isReferenceType()) { 765 return CheckReferenceType(Entity, IList, ElemType, Index, 766 StructuredList, StructuredIndex); 767 } 768 769 if (const ArrayType *arrayType = SemaRef.Context.getAsArrayType(ElemType)) { 770 // arrayType can be incomplete if we're initializing a flexible 771 // array member. There's nothing we can do with the completed 772 // type here, though. 773 774 if (Expr *Str = IsStringInit(expr, arrayType, SemaRef.Context)) { 775 if (!VerifyOnly) { 776 CheckStringInit(Str, ElemType, arrayType, SemaRef); 777 UpdateStructuredListElement(StructuredList, StructuredIndex, Str); 778 } 779 ++Index; 780 return; 781 } 782 783 // Fall through for subaggregate initialization. 784 785 } else if (SemaRef.getLangOptions().CPlusPlus) { 786 // C++ [dcl.init.aggr]p12: 787 // All implicit type conversions (clause 4) are considered when 788 // initializing the aggregate member with an initializer from 789 // an initializer-list. If the initializer can initialize a 790 // member, the member is initialized. [...] 791 792 // FIXME: Better EqualLoc? 793 InitializationKind Kind = 794 InitializationKind::CreateCopy(expr->getLocStart(), SourceLocation()); 795 InitializationSequence Seq(SemaRef, Entity, Kind, &expr, 1); 796 797 if (Seq) { 798 if (!VerifyOnly) { 799 ExprResult Result = 800 Seq.Perform(SemaRef, Entity, Kind, MultiExprArg(&expr, 1)); 801 if (Result.isInvalid()) 802 hadError = true; 803 804 UpdateStructuredListElement(StructuredList, StructuredIndex, 805 Result.takeAs<Expr>()); 806 } 807 ++Index; 808 return; 809 } 810 811 // Fall through for subaggregate initialization 812 } else { 813 // C99 6.7.8p13: 814 // 815 // The initializer for a structure or union object that has 816 // automatic storage duration shall be either an initializer 817 // list as described below, or a single expression that has 818 // compatible structure or union type. In the latter case, the 819 // initial value of the object, including unnamed members, is 820 // that of the expression. 821 ExprResult ExprRes = SemaRef.Owned(expr); 822 if ((ElemType->isRecordType() || ElemType->isVectorType()) && 823 SemaRef.CheckSingleAssignmentConstraints(ElemType, ExprRes, 824 !VerifyOnly) 825 == Sema::Compatible) { 826 if (ExprRes.isInvalid()) 827 hadError = true; 828 else { 829 ExprRes = SemaRef.DefaultFunctionArrayLvalueConversion(ExprRes.take()); 830 if (ExprRes.isInvalid()) 831 hadError = true; 832 } 833 UpdateStructuredListElement(StructuredList, StructuredIndex, 834 ExprRes.takeAs<Expr>()); 835 ++Index; 836 return; 837 } 838 ExprRes.release(); 839 // Fall through for subaggregate initialization 840 } 841 842 // C++ [dcl.init.aggr]p12: 843 // 844 // [...] Otherwise, if the member is itself a non-empty 845 // subaggregate, brace elision is assumed and the initializer is 846 // considered for the initialization of the first member of 847 // the subaggregate. 848 if (!SemaRef.getLangOptions().OpenCL && 849 (ElemType->isAggregateType() || ElemType->isVectorType())) { 850 CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList, 851 StructuredIndex); 852 ++StructuredIndex; 853 } else { 854 if (!VerifyOnly) { 855 // We cannot initialize this element, so let 856 // PerformCopyInitialization produce the appropriate diagnostic. 857 SemaRef.PerformCopyInitialization(Entity, SourceLocation(), 858 SemaRef.Owned(expr), 859 /*TopLevelOfInitList=*/true); 860 } 861 hadError = true; 862 ++Index; 863 ++StructuredIndex; 864 } 865} 866 867void InitListChecker::CheckComplexType(const InitializedEntity &Entity, 868 InitListExpr *IList, QualType DeclType, 869 unsigned &Index, 870 InitListExpr *StructuredList, 871 unsigned &StructuredIndex) { 872 assert(Index == 0 && "Index in explicit init list must be zero"); 873 874 // As an extension, clang supports complex initializers, which initialize 875 // a complex number component-wise. When an explicit initializer list for 876 // a complex number contains two two initializers, this extension kicks in: 877 // it exepcts the initializer list to contain two elements convertible to 878 // the element type of the complex type. The first element initializes 879 // the real part, and the second element intitializes the imaginary part. 880 881 if (IList->getNumInits() != 2) 882 return CheckScalarType(Entity, IList, DeclType, Index, StructuredList, 883 StructuredIndex); 884 885 // This is an extension in C. (The builtin _Complex type does not exist 886 // in the C++ standard.) 887 if (!SemaRef.getLangOptions().CPlusPlus && !VerifyOnly) 888 SemaRef.Diag(IList->getLocStart(), diag::ext_complex_component_init) 889 << IList->getSourceRange(); 890 891 // Initialize the complex number. 892 QualType elementType = DeclType->getAs<ComplexType>()->getElementType(); 893 InitializedEntity ElementEntity = 894 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 895 896 for (unsigned i = 0; i < 2; ++i) { 897 ElementEntity.setElementIndex(Index); 898 CheckSubElementType(ElementEntity, IList, elementType, Index, 899 StructuredList, StructuredIndex); 900 } 901} 902 903 904void InitListChecker::CheckScalarType(const InitializedEntity &Entity, 905 InitListExpr *IList, QualType DeclType, 906 unsigned &Index, 907 InitListExpr *StructuredList, 908 unsigned &StructuredIndex) { 909 if (Index >= IList->getNumInits()) { 910 if (!VerifyOnly) 911 SemaRef.Diag(IList->getLocStart(), 912 SemaRef.getLangOptions().CPlusPlus0x ? 913 diag::warn_cxx98_compat_empty_scalar_initializer : 914 diag::err_empty_scalar_initializer) 915 << IList->getSourceRange(); 916 hadError = !SemaRef.getLangOptions().CPlusPlus0x; 917 ++Index; 918 ++StructuredIndex; 919 return; 920 } 921 922 Expr *expr = IList->getInit(Index); 923 if (InitListExpr *SubIList = dyn_cast<InitListExpr>(expr)) { 924 if (!VerifyOnly) 925 SemaRef.Diag(SubIList->getLocStart(), 926 diag::warn_many_braces_around_scalar_init) 927 << SubIList->getSourceRange(); 928 929 CheckScalarType(Entity, SubIList, DeclType, Index, StructuredList, 930 StructuredIndex); 931 return; 932 } else if (isa<DesignatedInitExpr>(expr)) { 933 if (!VerifyOnly) 934 SemaRef.Diag(expr->getSourceRange().getBegin(), 935 diag::err_designator_for_scalar_init) 936 << DeclType << expr->getSourceRange(); 937 hadError = true; 938 ++Index; 939 ++StructuredIndex; 940 return; 941 } 942 943 if (VerifyOnly) { 944 if (!SemaRef.CanPerformCopyInitialization(Entity, SemaRef.Owned(expr))) 945 hadError = true; 946 ++Index; 947 return; 948 } 949 950 ExprResult Result = 951 SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), 952 SemaRef.Owned(expr), 953 /*TopLevelOfInitList=*/true); 954 955 Expr *ResultExpr = 0; 956 957 if (Result.isInvalid()) 958 hadError = true; // types weren't compatible. 959 else { 960 ResultExpr = Result.takeAs<Expr>(); 961 962 if (ResultExpr != expr) { 963 // The type was promoted, update initializer list. 964 IList->setInit(Index, ResultExpr); 965 } 966 } 967 if (hadError) 968 ++StructuredIndex; 969 else 970 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr); 971 ++Index; 972} 973 974void InitListChecker::CheckReferenceType(const InitializedEntity &Entity, 975 InitListExpr *IList, QualType DeclType, 976 unsigned &Index, 977 InitListExpr *StructuredList, 978 unsigned &StructuredIndex) { 979 if (Index >= IList->getNumInits()) { 980 // FIXME: It would be wonderful if we could point at the actual member. In 981 // general, it would be useful to pass location information down the stack, 982 // so that we know the location (or decl) of the "current object" being 983 // initialized. 984 if (!VerifyOnly) 985 SemaRef.Diag(IList->getLocStart(), 986 diag::err_init_reference_member_uninitialized) 987 << DeclType 988 << IList->getSourceRange(); 989 hadError = true; 990 ++Index; 991 ++StructuredIndex; 992 return; 993 } 994 995 Expr *expr = IList->getInit(Index); 996 if (isa<InitListExpr>(expr) && !SemaRef.getLangOptions().CPlusPlus0x) { 997 if (!VerifyOnly) 998 SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list) 999 << DeclType << IList->getSourceRange(); 1000 hadError = true; 1001 ++Index; 1002 ++StructuredIndex; 1003 return; 1004 } 1005 1006 if (VerifyOnly) { 1007 if (!SemaRef.CanPerformCopyInitialization(Entity, SemaRef.Owned(expr))) 1008 hadError = true; 1009 ++Index; 1010 return; 1011 } 1012 1013 ExprResult Result = 1014 SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), 1015 SemaRef.Owned(expr), 1016 /*TopLevelOfInitList=*/true); 1017 1018 if (Result.isInvalid()) 1019 hadError = true; 1020 1021 expr = Result.takeAs<Expr>(); 1022 IList->setInit(Index, expr); 1023 1024 if (hadError) 1025 ++StructuredIndex; 1026 else 1027 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 1028 ++Index; 1029} 1030 1031void InitListChecker::CheckVectorType(const InitializedEntity &Entity, 1032 InitListExpr *IList, QualType DeclType, 1033 unsigned &Index, 1034 InitListExpr *StructuredList, 1035 unsigned &StructuredIndex) { 1036 const VectorType *VT = DeclType->getAs<VectorType>(); 1037 unsigned maxElements = VT->getNumElements(); 1038 unsigned numEltsInit = 0; 1039 QualType elementType = VT->getElementType(); 1040 1041 if (Index >= IList->getNumInits()) { 1042 // Make sure the element type can be value-initialized. 1043 if (VerifyOnly) 1044 CheckValueInitializable( 1045 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity)); 1046 return; 1047 } 1048 1049 if (!SemaRef.getLangOptions().OpenCL) { 1050 // If the initializing element is a vector, try to copy-initialize 1051 // instead of breaking it apart (which is doomed to failure anyway). 1052 Expr *Init = IList->getInit(Index); 1053 if (!isa<InitListExpr>(Init) && Init->getType()->isVectorType()) { 1054 if (VerifyOnly) { 1055 if (!SemaRef.CanPerformCopyInitialization(Entity, SemaRef.Owned(Init))) 1056 hadError = true; 1057 ++Index; 1058 return; 1059 } 1060 1061 ExprResult Result = 1062 SemaRef.PerformCopyInitialization(Entity, Init->getLocStart(), 1063 SemaRef.Owned(Init), 1064 /*TopLevelOfInitList=*/true); 1065 1066 Expr *ResultExpr = 0; 1067 if (Result.isInvalid()) 1068 hadError = true; // types weren't compatible. 1069 else { 1070 ResultExpr = Result.takeAs<Expr>(); 1071 1072 if (ResultExpr != Init) { 1073 // The type was promoted, update initializer list. 1074 IList->setInit(Index, ResultExpr); 1075 } 1076 } 1077 if (hadError) 1078 ++StructuredIndex; 1079 else 1080 UpdateStructuredListElement(StructuredList, StructuredIndex, 1081 ResultExpr); 1082 ++Index; 1083 return; 1084 } 1085 1086 InitializedEntity ElementEntity = 1087 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 1088 1089 for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) { 1090 // Don't attempt to go past the end of the init list 1091 if (Index >= IList->getNumInits()) { 1092 if (VerifyOnly) 1093 CheckValueInitializable(ElementEntity); 1094 break; 1095 } 1096 1097 ElementEntity.setElementIndex(Index); 1098 CheckSubElementType(ElementEntity, IList, elementType, Index, 1099 StructuredList, StructuredIndex); 1100 } 1101 return; 1102 } 1103 1104 InitializedEntity ElementEntity = 1105 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 1106 1107 // OpenCL initializers allows vectors to be constructed from vectors. 1108 for (unsigned i = 0; i < maxElements; ++i) { 1109 // Don't attempt to go past the end of the init list 1110 if (Index >= IList->getNumInits()) 1111 break; 1112 1113 ElementEntity.setElementIndex(Index); 1114 1115 QualType IType = IList->getInit(Index)->getType(); 1116 if (!IType->isVectorType()) { 1117 CheckSubElementType(ElementEntity, IList, elementType, Index, 1118 StructuredList, StructuredIndex); 1119 ++numEltsInit; 1120 } else { 1121 QualType VecType; 1122 const VectorType *IVT = IType->getAs<VectorType>(); 1123 unsigned numIElts = IVT->getNumElements(); 1124 1125 if (IType->isExtVectorType()) 1126 VecType = SemaRef.Context.getExtVectorType(elementType, numIElts); 1127 else 1128 VecType = SemaRef.Context.getVectorType(elementType, numIElts, 1129 IVT->getVectorKind()); 1130 CheckSubElementType(ElementEntity, IList, VecType, Index, 1131 StructuredList, StructuredIndex); 1132 numEltsInit += numIElts; 1133 } 1134 } 1135 1136 // OpenCL requires all elements to be initialized. 1137 if (numEltsInit != maxElements) { 1138 if (!VerifyOnly) 1139 SemaRef.Diag(IList->getSourceRange().getBegin(), 1140 diag::err_vector_incorrect_num_initializers) 1141 << (numEltsInit < maxElements) << maxElements << numEltsInit; 1142 hadError = true; 1143 } 1144} 1145 1146void InitListChecker::CheckArrayType(const InitializedEntity &Entity, 1147 InitListExpr *IList, QualType &DeclType, 1148 llvm::APSInt elementIndex, 1149 bool SubobjectIsDesignatorContext, 1150 unsigned &Index, 1151 InitListExpr *StructuredList, 1152 unsigned &StructuredIndex) { 1153 const ArrayType *arrayType = SemaRef.Context.getAsArrayType(DeclType); 1154 1155 // Check for the special-case of initializing an array with a string. 1156 if (Index < IList->getNumInits()) { 1157 if (Expr *Str = IsStringInit(IList->getInit(Index), arrayType, 1158 SemaRef.Context)) { 1159 // We place the string literal directly into the resulting 1160 // initializer list. This is the only place where the structure 1161 // of the structured initializer list doesn't match exactly, 1162 // because doing so would involve allocating one character 1163 // constant for each string. 1164 if (!VerifyOnly) { 1165 CheckStringInit(Str, DeclType, arrayType, SemaRef); 1166 UpdateStructuredListElement(StructuredList, StructuredIndex, Str); 1167 StructuredList->resizeInits(SemaRef.Context, StructuredIndex); 1168 } 1169 ++Index; 1170 return; 1171 } 1172 } 1173 if (const VariableArrayType *VAT = dyn_cast<VariableArrayType>(arrayType)) { 1174 // Check for VLAs; in standard C it would be possible to check this 1175 // earlier, but I don't know where clang accepts VLAs (gcc accepts 1176 // them in all sorts of strange places). 1177 if (!VerifyOnly) 1178 SemaRef.Diag(VAT->getSizeExpr()->getLocStart(), 1179 diag::err_variable_object_no_init) 1180 << VAT->getSizeExpr()->getSourceRange(); 1181 hadError = true; 1182 ++Index; 1183 ++StructuredIndex; 1184 return; 1185 } 1186 1187 // We might know the maximum number of elements in advance. 1188 llvm::APSInt maxElements(elementIndex.getBitWidth(), 1189 elementIndex.isUnsigned()); 1190 bool maxElementsKnown = false; 1191 if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(arrayType)) { 1192 maxElements = CAT->getSize(); 1193 elementIndex = elementIndex.extOrTrunc(maxElements.getBitWidth()); 1194 elementIndex.setIsUnsigned(maxElements.isUnsigned()); 1195 maxElementsKnown = true; 1196 } 1197 1198 QualType elementType = arrayType->getElementType(); 1199 while (Index < IList->getNumInits()) { 1200 Expr *Init = IList->getInit(Index); 1201 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) { 1202 // If we're not the subobject that matches up with the '{' for 1203 // the designator, we shouldn't be handling the 1204 // designator. Return immediately. 1205 if (!SubobjectIsDesignatorContext) 1206 return; 1207 1208 // Handle this designated initializer. elementIndex will be 1209 // updated to be the next array element we'll initialize. 1210 if (CheckDesignatedInitializer(Entity, IList, DIE, 0, 1211 DeclType, 0, &elementIndex, Index, 1212 StructuredList, StructuredIndex, true, 1213 false)) { 1214 hadError = true; 1215 continue; 1216 } 1217 1218 if (elementIndex.getBitWidth() > maxElements.getBitWidth()) 1219 maxElements = maxElements.extend(elementIndex.getBitWidth()); 1220 else if (elementIndex.getBitWidth() < maxElements.getBitWidth()) 1221 elementIndex = elementIndex.extend(maxElements.getBitWidth()); 1222 elementIndex.setIsUnsigned(maxElements.isUnsigned()); 1223 1224 // If the array is of incomplete type, keep track of the number of 1225 // elements in the initializer. 1226 if (!maxElementsKnown && elementIndex > maxElements) 1227 maxElements = elementIndex; 1228 1229 continue; 1230 } 1231 1232 // If we know the maximum number of elements, and we've already 1233 // hit it, stop consuming elements in the initializer list. 1234 if (maxElementsKnown && elementIndex == maxElements) 1235 break; 1236 1237 InitializedEntity ElementEntity = 1238 InitializedEntity::InitializeElement(SemaRef.Context, StructuredIndex, 1239 Entity); 1240 // Check this element. 1241 CheckSubElementType(ElementEntity, IList, elementType, Index, 1242 StructuredList, StructuredIndex); 1243 ++elementIndex; 1244 1245 // If the array is of incomplete type, keep track of the number of 1246 // elements in the initializer. 1247 if (!maxElementsKnown && elementIndex > maxElements) 1248 maxElements = elementIndex; 1249 } 1250 if (!hadError && DeclType->isIncompleteArrayType() && !VerifyOnly) { 1251 // If this is an incomplete array type, the actual type needs to 1252 // be calculated here. 1253 llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned()); 1254 if (maxElements == Zero) { 1255 // Sizing an array implicitly to zero is not allowed by ISO C, 1256 // but is supported by GNU. 1257 SemaRef.Diag(IList->getLocStart(), 1258 diag::ext_typecheck_zero_array_size); 1259 } 1260 1261 DeclType = SemaRef.Context.getConstantArrayType(elementType, maxElements, 1262 ArrayType::Normal, 0); 1263 } 1264 if (!hadError && VerifyOnly) { 1265 // Check if there are any members of the array that get value-initialized. 1266 // If so, check if doing that is possible. 1267 // FIXME: This needs to detect holes left by designated initializers too. 1268 if (maxElementsKnown && elementIndex < maxElements) 1269 CheckValueInitializable(InitializedEntity::InitializeElement( 1270 SemaRef.Context, 0, Entity)); 1271 } 1272} 1273 1274bool InitListChecker::CheckFlexibleArrayInit(const InitializedEntity &Entity, 1275 Expr *InitExpr, 1276 FieldDecl *Field, 1277 bool TopLevelObject) { 1278 // Handle GNU flexible array initializers. 1279 unsigned FlexArrayDiag; 1280 if (isa<InitListExpr>(InitExpr) && 1281 cast<InitListExpr>(InitExpr)->getNumInits() == 0) { 1282 // Empty flexible array init always allowed as an extension 1283 FlexArrayDiag = diag::ext_flexible_array_init; 1284 } else if (SemaRef.getLangOptions().CPlusPlus) { 1285 // Disallow flexible array init in C++; it is not required for gcc 1286 // compatibility, and it needs work to IRGen correctly in general. 1287 FlexArrayDiag = diag::err_flexible_array_init; 1288 } else if (!TopLevelObject) { 1289 // Disallow flexible array init on non-top-level object 1290 FlexArrayDiag = diag::err_flexible_array_init; 1291 } else if (Entity.getKind() != InitializedEntity::EK_Variable) { 1292 // Disallow flexible array init on anything which is not a variable. 1293 FlexArrayDiag = diag::err_flexible_array_init; 1294 } else if (cast<VarDecl>(Entity.getDecl())->hasLocalStorage()) { 1295 // Disallow flexible array init on local variables. 1296 FlexArrayDiag = diag::err_flexible_array_init; 1297 } else { 1298 // Allow other cases. 1299 FlexArrayDiag = diag::ext_flexible_array_init; 1300 } 1301 1302 if (!VerifyOnly) { 1303 SemaRef.Diag(InitExpr->getSourceRange().getBegin(), 1304 FlexArrayDiag) 1305 << InitExpr->getSourceRange().getBegin(); 1306 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1307 << Field; 1308 } 1309 1310 return FlexArrayDiag != diag::ext_flexible_array_init; 1311} 1312 1313void InitListChecker::CheckStructUnionTypes(const InitializedEntity &Entity, 1314 InitListExpr *IList, 1315 QualType DeclType, 1316 RecordDecl::field_iterator Field, 1317 bool SubobjectIsDesignatorContext, 1318 unsigned &Index, 1319 InitListExpr *StructuredList, 1320 unsigned &StructuredIndex, 1321 bool TopLevelObject) { 1322 RecordDecl* structDecl = DeclType->getAs<RecordType>()->getDecl(); 1323 1324 // If the record is invalid, some of it's members are invalid. To avoid 1325 // confusion, we forgo checking the intializer for the entire record. 1326 if (structDecl->isInvalidDecl()) { 1327 hadError = true; 1328 return; 1329 } 1330 1331 if (DeclType->isUnionType() && IList->getNumInits() == 0) { 1332 // Value-initialize the first named member of the union. 1333 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 1334 for (RecordDecl::field_iterator FieldEnd = RD->field_end(); 1335 Field != FieldEnd; ++Field) { 1336 if (Field->getDeclName()) { 1337 if (VerifyOnly) 1338 CheckValueInitializable( 1339 InitializedEntity::InitializeMember(*Field, &Entity)); 1340 else 1341 StructuredList->setInitializedFieldInUnion(*Field); 1342 break; 1343 } 1344 } 1345 return; 1346 } 1347 1348 // If structDecl is a forward declaration, this loop won't do 1349 // anything except look at designated initializers; That's okay, 1350 // because an error should get printed out elsewhere. It might be 1351 // worthwhile to skip over the rest of the initializer, though. 1352 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 1353 RecordDecl::field_iterator FieldEnd = RD->field_end(); 1354 bool InitializedSomething = false; 1355 bool CheckForMissingFields = true; 1356 while (Index < IList->getNumInits()) { 1357 Expr *Init = IList->getInit(Index); 1358 1359 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) { 1360 // If we're not the subobject that matches up with the '{' for 1361 // the designator, we shouldn't be handling the 1362 // designator. Return immediately. 1363 if (!SubobjectIsDesignatorContext) 1364 return; 1365 1366 // Handle this designated initializer. Field will be updated to 1367 // the next field that we'll be initializing. 1368 if (CheckDesignatedInitializer(Entity, IList, DIE, 0, 1369 DeclType, &Field, 0, Index, 1370 StructuredList, StructuredIndex, 1371 true, TopLevelObject)) 1372 hadError = true; 1373 1374 InitializedSomething = true; 1375 1376 // Disable check for missing fields when designators are used. 1377 // This matches gcc behaviour. 1378 CheckForMissingFields = false; 1379 continue; 1380 } 1381 1382 if (Field == FieldEnd) { 1383 // We've run out of fields. We're done. 1384 break; 1385 } 1386 1387 // We've already initialized a member of a union. We're done. 1388 if (InitializedSomething && DeclType->isUnionType()) 1389 break; 1390 1391 // If we've hit the flexible array member at the end, we're done. 1392 if (Field->getType()->isIncompleteArrayType()) 1393 break; 1394 1395 if (Field->isUnnamedBitfield()) { 1396 // Don't initialize unnamed bitfields, e.g. "int : 20;" 1397 ++Field; 1398 continue; 1399 } 1400 1401 // Make sure we can use this declaration. 1402 bool InvalidUse; 1403 if (VerifyOnly) 1404 InvalidUse = !SemaRef.CanUseDecl(*Field); 1405 else 1406 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, 1407 IList->getInit(Index)->getLocStart()); 1408 if (InvalidUse) { 1409 ++Index; 1410 ++Field; 1411 hadError = true; 1412 continue; 1413 } 1414 1415 InitializedEntity MemberEntity = 1416 InitializedEntity::InitializeMember(*Field, &Entity); 1417 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1418 StructuredList, StructuredIndex); 1419 InitializedSomething = true; 1420 1421 if (DeclType->isUnionType() && !VerifyOnly) { 1422 // Initialize the first field within the union. 1423 StructuredList->setInitializedFieldInUnion(*Field); 1424 } 1425 1426 ++Field; 1427 } 1428 1429 // Emit warnings for missing struct field initializers. 1430 if (!VerifyOnly && InitializedSomething && CheckForMissingFields && 1431 Field != FieldEnd && !Field->getType()->isIncompleteArrayType() && 1432 !DeclType->isUnionType()) { 1433 // It is possible we have one or more unnamed bitfields remaining. 1434 // Find first (if any) named field and emit warning. 1435 for (RecordDecl::field_iterator it = Field, end = RD->field_end(); 1436 it != end; ++it) { 1437 if (!it->isUnnamedBitfield()) { 1438 SemaRef.Diag(IList->getSourceRange().getEnd(), 1439 diag::warn_missing_field_initializers) << it->getName(); 1440 break; 1441 } 1442 } 1443 } 1444 1445 // Check that any remaining fields can be value-initialized. 1446 if (VerifyOnly && Field != FieldEnd && !DeclType->isUnionType() && 1447 !Field->getType()->isIncompleteArrayType()) { 1448 // FIXME: Should check for holes left by designated initializers too. 1449 for (; Field != FieldEnd && !hadError; ++Field) { 1450 if (!Field->isUnnamedBitfield()) 1451 CheckValueInitializable( 1452 InitializedEntity::InitializeMember(*Field, &Entity)); 1453 } 1454 } 1455 1456 if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() || 1457 Index >= IList->getNumInits()) 1458 return; 1459 1460 if (CheckFlexibleArrayInit(Entity, IList->getInit(Index), *Field, 1461 TopLevelObject)) { 1462 hadError = true; 1463 ++Index; 1464 return; 1465 } 1466 1467 InitializedEntity MemberEntity = 1468 InitializedEntity::InitializeMember(*Field, &Entity); 1469 1470 if (isa<InitListExpr>(IList->getInit(Index))) 1471 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1472 StructuredList, StructuredIndex); 1473 else 1474 CheckImplicitInitList(MemberEntity, IList, Field->getType(), Index, 1475 StructuredList, StructuredIndex); 1476} 1477 1478/// \brief Expand a field designator that refers to a member of an 1479/// anonymous struct or union into a series of field designators that 1480/// refers to the field within the appropriate subobject. 1481/// 1482static void ExpandAnonymousFieldDesignator(Sema &SemaRef, 1483 DesignatedInitExpr *DIE, 1484 unsigned DesigIdx, 1485 IndirectFieldDecl *IndirectField) { 1486 typedef DesignatedInitExpr::Designator Designator; 1487 1488 // Build the replacement designators. 1489 SmallVector<Designator, 4> Replacements; 1490 for (IndirectFieldDecl::chain_iterator PI = IndirectField->chain_begin(), 1491 PE = IndirectField->chain_end(); PI != PE; ++PI) { 1492 if (PI + 1 == PE) 1493 Replacements.push_back(Designator((IdentifierInfo *)0, 1494 DIE->getDesignator(DesigIdx)->getDotLoc(), 1495 DIE->getDesignator(DesigIdx)->getFieldLoc())); 1496 else 1497 Replacements.push_back(Designator((IdentifierInfo *)0, SourceLocation(), 1498 SourceLocation())); 1499 assert(isa<FieldDecl>(*PI)); 1500 Replacements.back().setField(cast<FieldDecl>(*PI)); 1501 } 1502 1503 // Expand the current designator into the set of replacement 1504 // designators, so we have a full subobject path down to where the 1505 // member of the anonymous struct/union is actually stored. 1506 DIE->ExpandDesignator(SemaRef.Context, DesigIdx, &Replacements[0], 1507 &Replacements[0] + Replacements.size()); 1508} 1509 1510/// \brief Given an implicit anonymous field, search the IndirectField that 1511/// corresponds to FieldName. 1512static IndirectFieldDecl *FindIndirectFieldDesignator(FieldDecl *AnonField, 1513 IdentifierInfo *FieldName) { 1514 assert(AnonField->isAnonymousStructOrUnion()); 1515 Decl *NextDecl = AnonField->getNextDeclInContext(); 1516 while (IndirectFieldDecl *IF = 1517 dyn_cast_or_null<IndirectFieldDecl>(NextDecl)) { 1518 if (FieldName && FieldName == IF->getAnonField()->getIdentifier()) 1519 return IF; 1520 NextDecl = NextDecl->getNextDeclInContext(); 1521 } 1522 return 0; 1523} 1524 1525static DesignatedInitExpr *CloneDesignatedInitExpr(Sema &SemaRef, 1526 DesignatedInitExpr *DIE) { 1527 unsigned NumIndexExprs = DIE->getNumSubExprs() - 1; 1528 SmallVector<Expr*, 4> IndexExprs(NumIndexExprs); 1529 for (unsigned I = 0; I < NumIndexExprs; ++I) 1530 IndexExprs[I] = DIE->getSubExpr(I + 1); 1531 return DesignatedInitExpr::Create(SemaRef.Context, DIE->designators_begin(), 1532 DIE->size(), IndexExprs.data(), 1533 NumIndexExprs, DIE->getEqualOrColonLoc(), 1534 DIE->usesGNUSyntax(), DIE->getInit()); 1535} 1536 1537namespace { 1538 1539// Callback to only accept typo corrections that are for field members of 1540// the given struct or union. 1541class FieldInitializerValidatorCCC : public CorrectionCandidateCallback { 1542 public: 1543 explicit FieldInitializerValidatorCCC(RecordDecl *RD) 1544 : Record(RD) {} 1545 1546 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 1547 FieldDecl *FD = candidate.getCorrectionDeclAs<FieldDecl>(); 1548 return FD && FD->getDeclContext()->getRedeclContext()->Equals(Record); 1549 } 1550 1551 private: 1552 RecordDecl *Record; 1553}; 1554 1555} 1556 1557/// @brief Check the well-formedness of a C99 designated initializer. 1558/// 1559/// Determines whether the designated initializer @p DIE, which 1560/// resides at the given @p Index within the initializer list @p 1561/// IList, is well-formed for a current object of type @p DeclType 1562/// (C99 6.7.8). The actual subobject that this designator refers to 1563/// within the current subobject is returned in either 1564/// @p NextField or @p NextElementIndex (whichever is appropriate). 1565/// 1566/// @param IList The initializer list in which this designated 1567/// initializer occurs. 1568/// 1569/// @param DIE The designated initializer expression. 1570/// 1571/// @param DesigIdx The index of the current designator. 1572/// 1573/// @param DeclType The type of the "current object" (C99 6.7.8p17), 1574/// into which the designation in @p DIE should refer. 1575/// 1576/// @param NextField If non-NULL and the first designator in @p DIE is 1577/// a field, this will be set to the field declaration corresponding 1578/// to the field named by the designator. 1579/// 1580/// @param NextElementIndex If non-NULL and the first designator in @p 1581/// DIE is an array designator or GNU array-range designator, this 1582/// will be set to the last index initialized by this designator. 1583/// 1584/// @param Index Index into @p IList where the designated initializer 1585/// @p DIE occurs. 1586/// 1587/// @param StructuredList The initializer list expression that 1588/// describes all of the subobject initializers in the order they'll 1589/// actually be initialized. 1590/// 1591/// @returns true if there was an error, false otherwise. 1592bool 1593InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity, 1594 InitListExpr *IList, 1595 DesignatedInitExpr *DIE, 1596 unsigned DesigIdx, 1597 QualType &CurrentObjectType, 1598 RecordDecl::field_iterator *NextField, 1599 llvm::APSInt *NextElementIndex, 1600 unsigned &Index, 1601 InitListExpr *StructuredList, 1602 unsigned &StructuredIndex, 1603 bool FinishSubobjectInit, 1604 bool TopLevelObject) { 1605 if (DesigIdx == DIE->size()) { 1606 // Check the actual initialization for the designated object type. 1607 bool prevHadError = hadError; 1608 1609 // Temporarily remove the designator expression from the 1610 // initializer list that the child calls see, so that we don't try 1611 // to re-process the designator. 1612 unsigned OldIndex = Index; 1613 IList->setInit(OldIndex, DIE->getInit()); 1614 1615 CheckSubElementType(Entity, IList, CurrentObjectType, Index, 1616 StructuredList, StructuredIndex); 1617 1618 // Restore the designated initializer expression in the syntactic 1619 // form of the initializer list. 1620 if (IList->getInit(OldIndex) != DIE->getInit()) 1621 DIE->setInit(IList->getInit(OldIndex)); 1622 IList->setInit(OldIndex, DIE); 1623 1624 return hadError && !prevHadError; 1625 } 1626 1627 DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx); 1628 bool IsFirstDesignator = (DesigIdx == 0); 1629 if (!VerifyOnly) { 1630 assert((IsFirstDesignator || StructuredList) && 1631 "Need a non-designated initializer list to start from"); 1632 1633 // Determine the structural initializer list that corresponds to the 1634 // current subobject. 1635 StructuredList = IsFirstDesignator? SyntacticToSemantic.lookup(IList) 1636 : getStructuredSubobjectInit(IList, Index, CurrentObjectType, 1637 StructuredList, StructuredIndex, 1638 SourceRange(D->getStartLocation(), 1639 DIE->getSourceRange().getEnd())); 1640 assert(StructuredList && "Expected a structured initializer list"); 1641 } 1642 1643 if (D->isFieldDesignator()) { 1644 // C99 6.7.8p7: 1645 // 1646 // If a designator has the form 1647 // 1648 // . identifier 1649 // 1650 // then the current object (defined below) shall have 1651 // structure or union type and the identifier shall be the 1652 // name of a member of that type. 1653 const RecordType *RT = CurrentObjectType->getAs<RecordType>(); 1654 if (!RT) { 1655 SourceLocation Loc = D->getDotLoc(); 1656 if (Loc.isInvalid()) 1657 Loc = D->getFieldLoc(); 1658 if (!VerifyOnly) 1659 SemaRef.Diag(Loc, diag::err_field_designator_non_aggr) 1660 << SemaRef.getLangOptions().CPlusPlus << CurrentObjectType; 1661 ++Index; 1662 return true; 1663 } 1664 1665 // Note: we perform a linear search of the fields here, despite 1666 // the fact that we have a faster lookup method, because we always 1667 // need to compute the field's index. 1668 FieldDecl *KnownField = D->getField(); 1669 IdentifierInfo *FieldName = D->getFieldName(); 1670 unsigned FieldIndex = 0; 1671 RecordDecl::field_iterator 1672 Field = RT->getDecl()->field_begin(), 1673 FieldEnd = RT->getDecl()->field_end(); 1674 for (; Field != FieldEnd; ++Field) { 1675 if (Field->isUnnamedBitfield()) 1676 continue; 1677 1678 // If we find a field representing an anonymous field, look in the 1679 // IndirectFieldDecl that follow for the designated initializer. 1680 if (!KnownField && Field->isAnonymousStructOrUnion()) { 1681 if (IndirectFieldDecl *IF = 1682 FindIndirectFieldDesignator(*Field, FieldName)) { 1683 // In verify mode, don't modify the original. 1684 if (VerifyOnly) 1685 DIE = CloneDesignatedInitExpr(SemaRef, DIE); 1686 ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, IF); 1687 D = DIE->getDesignator(DesigIdx); 1688 break; 1689 } 1690 } 1691 if (KnownField && KnownField == *Field) 1692 break; 1693 if (FieldName && FieldName == Field->getIdentifier()) 1694 break; 1695 1696 ++FieldIndex; 1697 } 1698 1699 if (Field == FieldEnd) { 1700 if (VerifyOnly) { 1701 ++Index; 1702 return true; // No typo correction when just trying this out. 1703 } 1704 1705 // There was no normal field in the struct with the designated 1706 // name. Perform another lookup for this name, which may find 1707 // something that we can't designate (e.g., a member function), 1708 // may find nothing, or may find a member of an anonymous 1709 // struct/union. 1710 DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName); 1711 FieldDecl *ReplacementField = 0; 1712 if (Lookup.first == Lookup.second) { 1713 // Name lookup didn't find anything. Determine whether this 1714 // was a typo for another field name. 1715 FieldInitializerValidatorCCC Validator(RT->getDecl()); 1716 TypoCorrection Corrected = SemaRef.CorrectTypo( 1717 DeclarationNameInfo(FieldName, D->getFieldLoc()), 1718 Sema::LookupMemberName, /*Scope=*/0, /*SS=*/0, Validator, 1719 RT->getDecl()); 1720 if (Corrected) { 1721 std::string CorrectedStr( 1722 Corrected.getAsString(SemaRef.getLangOptions())); 1723 std::string CorrectedQuotedStr( 1724 Corrected.getQuoted(SemaRef.getLangOptions())); 1725 ReplacementField = Corrected.getCorrectionDeclAs<FieldDecl>(); 1726 SemaRef.Diag(D->getFieldLoc(), 1727 diag::err_field_designator_unknown_suggest) 1728 << FieldName << CurrentObjectType << CorrectedQuotedStr 1729 << FixItHint::CreateReplacement(D->getFieldLoc(), CorrectedStr); 1730 SemaRef.Diag(ReplacementField->getLocation(), 1731 diag::note_previous_decl) << CorrectedQuotedStr; 1732 hadError = true; 1733 } else { 1734 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown) 1735 << FieldName << CurrentObjectType; 1736 ++Index; 1737 return true; 1738 } 1739 } 1740 1741 if (!ReplacementField) { 1742 // Name lookup found something, but it wasn't a field. 1743 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield) 1744 << FieldName; 1745 SemaRef.Diag((*Lookup.first)->getLocation(), 1746 diag::note_field_designator_found); 1747 ++Index; 1748 return true; 1749 } 1750 1751 if (!KnownField) { 1752 // The replacement field comes from typo correction; find it 1753 // in the list of fields. 1754 FieldIndex = 0; 1755 Field = RT->getDecl()->field_begin(); 1756 for (; Field != FieldEnd; ++Field) { 1757 if (Field->isUnnamedBitfield()) 1758 continue; 1759 1760 if (ReplacementField == *Field || 1761 Field->getIdentifier() == ReplacementField->getIdentifier()) 1762 break; 1763 1764 ++FieldIndex; 1765 } 1766 } 1767 } 1768 1769 // All of the fields of a union are located at the same place in 1770 // the initializer list. 1771 if (RT->getDecl()->isUnion()) { 1772 FieldIndex = 0; 1773 if (!VerifyOnly) 1774 StructuredList->setInitializedFieldInUnion(*Field); 1775 } 1776 1777 // Make sure we can use this declaration. 1778 bool InvalidUse; 1779 if (VerifyOnly) 1780 InvalidUse = !SemaRef.CanUseDecl(*Field); 1781 else 1782 InvalidUse = SemaRef.DiagnoseUseOfDecl(*Field, D->getFieldLoc()); 1783 if (InvalidUse) { 1784 ++Index; 1785 return true; 1786 } 1787 1788 if (!VerifyOnly) { 1789 // Update the designator with the field declaration. 1790 D->setField(*Field); 1791 1792 // Make sure that our non-designated initializer list has space 1793 // for a subobject corresponding to this field. 1794 if (FieldIndex >= StructuredList->getNumInits()) 1795 StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1); 1796 } 1797 1798 // This designator names a flexible array member. 1799 if (Field->getType()->isIncompleteArrayType()) { 1800 bool Invalid = false; 1801 if ((DesigIdx + 1) != DIE->size()) { 1802 // We can't designate an object within the flexible array 1803 // member (because GCC doesn't allow it). 1804 if (!VerifyOnly) { 1805 DesignatedInitExpr::Designator *NextD 1806 = DIE->getDesignator(DesigIdx + 1); 1807 SemaRef.Diag(NextD->getStartLocation(), 1808 diag::err_designator_into_flexible_array_member) 1809 << SourceRange(NextD->getStartLocation(), 1810 DIE->getSourceRange().getEnd()); 1811 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1812 << *Field; 1813 } 1814 Invalid = true; 1815 } 1816 1817 if (!hadError && !isa<InitListExpr>(DIE->getInit()) && 1818 !isa<StringLiteral>(DIE->getInit())) { 1819 // The initializer is not an initializer list. 1820 if (!VerifyOnly) { 1821 SemaRef.Diag(DIE->getInit()->getSourceRange().getBegin(), 1822 diag::err_flexible_array_init_needs_braces) 1823 << DIE->getInit()->getSourceRange(); 1824 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1825 << *Field; 1826 } 1827 Invalid = true; 1828 } 1829 1830 // Check GNU flexible array initializer. 1831 if (!Invalid && CheckFlexibleArrayInit(Entity, DIE->getInit(), *Field, 1832 TopLevelObject)) 1833 Invalid = true; 1834 1835 if (Invalid) { 1836 ++Index; 1837 return true; 1838 } 1839 1840 // Initialize the array. 1841 bool prevHadError = hadError; 1842 unsigned newStructuredIndex = FieldIndex; 1843 unsigned OldIndex = Index; 1844 IList->setInit(Index, DIE->getInit()); 1845 1846 InitializedEntity MemberEntity = 1847 InitializedEntity::InitializeMember(*Field, &Entity); 1848 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1849 StructuredList, newStructuredIndex); 1850 1851 IList->setInit(OldIndex, DIE); 1852 if (hadError && !prevHadError) { 1853 ++Field; 1854 ++FieldIndex; 1855 if (NextField) 1856 *NextField = Field; 1857 StructuredIndex = FieldIndex; 1858 return true; 1859 } 1860 } else { 1861 // Recurse to check later designated subobjects. 1862 QualType FieldType = (*Field)->getType(); 1863 unsigned newStructuredIndex = FieldIndex; 1864 1865 InitializedEntity MemberEntity = 1866 InitializedEntity::InitializeMember(*Field, &Entity); 1867 if (CheckDesignatedInitializer(MemberEntity, IList, DIE, DesigIdx + 1, 1868 FieldType, 0, 0, Index, 1869 StructuredList, newStructuredIndex, 1870 true, false)) 1871 return true; 1872 } 1873 1874 // Find the position of the next field to be initialized in this 1875 // subobject. 1876 ++Field; 1877 ++FieldIndex; 1878 1879 // If this the first designator, our caller will continue checking 1880 // the rest of this struct/class/union subobject. 1881 if (IsFirstDesignator) { 1882 if (NextField) 1883 *NextField = Field; 1884 StructuredIndex = FieldIndex; 1885 return false; 1886 } 1887 1888 if (!FinishSubobjectInit) 1889 return false; 1890 1891 // We've already initialized something in the union; we're done. 1892 if (RT->getDecl()->isUnion()) 1893 return hadError; 1894 1895 // Check the remaining fields within this class/struct/union subobject. 1896 bool prevHadError = hadError; 1897 1898 CheckStructUnionTypes(Entity, IList, CurrentObjectType, Field, false, Index, 1899 StructuredList, FieldIndex); 1900 return hadError && !prevHadError; 1901 } 1902 1903 // C99 6.7.8p6: 1904 // 1905 // If a designator has the form 1906 // 1907 // [ constant-expression ] 1908 // 1909 // then the current object (defined below) shall have array 1910 // type and the expression shall be an integer constant 1911 // expression. If the array is of unknown size, any 1912 // nonnegative value is valid. 1913 // 1914 // Additionally, cope with the GNU extension that permits 1915 // designators of the form 1916 // 1917 // [ constant-expression ... constant-expression ] 1918 const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType); 1919 if (!AT) { 1920 if (!VerifyOnly) 1921 SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array) 1922 << CurrentObjectType; 1923 ++Index; 1924 return true; 1925 } 1926 1927 Expr *IndexExpr = 0; 1928 llvm::APSInt DesignatedStartIndex, DesignatedEndIndex; 1929 if (D->isArrayDesignator()) { 1930 IndexExpr = DIE->getArrayIndex(*D); 1931 DesignatedStartIndex = IndexExpr->EvaluateKnownConstInt(SemaRef.Context); 1932 DesignatedEndIndex = DesignatedStartIndex; 1933 } else { 1934 assert(D->isArrayRangeDesignator() && "Need array-range designator"); 1935 1936 DesignatedStartIndex = 1937 DIE->getArrayRangeStart(*D)->EvaluateKnownConstInt(SemaRef.Context); 1938 DesignatedEndIndex = 1939 DIE->getArrayRangeEnd(*D)->EvaluateKnownConstInt(SemaRef.Context); 1940 IndexExpr = DIE->getArrayRangeEnd(*D); 1941 1942 // Codegen can't handle evaluating array range designators that have side 1943 // effects, because we replicate the AST value for each initialized element. 1944 // As such, set the sawArrayRangeDesignator() bit if we initialize multiple 1945 // elements with something that has a side effect, so codegen can emit an 1946 // "error unsupported" error instead of miscompiling the app. 1947 if (DesignatedStartIndex.getZExtValue()!=DesignatedEndIndex.getZExtValue()&& 1948 DIE->getInit()->HasSideEffects(SemaRef.Context) && !VerifyOnly) 1949 FullyStructuredList->sawArrayRangeDesignator(); 1950 } 1951 1952 if (isa<ConstantArrayType>(AT)) { 1953 llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false); 1954 DesignatedStartIndex 1955 = DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth()); 1956 DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned()); 1957 DesignatedEndIndex 1958 = DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth()); 1959 DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned()); 1960 if (DesignatedEndIndex >= MaxElements) { 1961 if (!VerifyOnly) 1962 SemaRef.Diag(IndexExpr->getSourceRange().getBegin(), 1963 diag::err_array_designator_too_large) 1964 << DesignatedEndIndex.toString(10) << MaxElements.toString(10) 1965 << IndexExpr->getSourceRange(); 1966 ++Index; 1967 return true; 1968 } 1969 } else { 1970 // Make sure the bit-widths and signedness match. 1971 if (DesignatedStartIndex.getBitWidth() > DesignatedEndIndex.getBitWidth()) 1972 DesignatedEndIndex 1973 = DesignatedEndIndex.extend(DesignatedStartIndex.getBitWidth()); 1974 else if (DesignatedStartIndex.getBitWidth() < 1975 DesignatedEndIndex.getBitWidth()) 1976 DesignatedStartIndex 1977 = DesignatedStartIndex.extend(DesignatedEndIndex.getBitWidth()); 1978 DesignatedStartIndex.setIsUnsigned(true); 1979 DesignatedEndIndex.setIsUnsigned(true); 1980 } 1981 1982 // Make sure that our non-designated initializer list has space 1983 // for a subobject corresponding to this array element. 1984 if (!VerifyOnly && 1985 DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits()) 1986 StructuredList->resizeInits(SemaRef.Context, 1987 DesignatedEndIndex.getZExtValue() + 1); 1988 1989 // Repeatedly perform subobject initializations in the range 1990 // [DesignatedStartIndex, DesignatedEndIndex]. 1991 1992 // Move to the next designator 1993 unsigned ElementIndex = DesignatedStartIndex.getZExtValue(); 1994 unsigned OldIndex = Index; 1995 1996 InitializedEntity ElementEntity = 1997 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 1998 1999 while (DesignatedStartIndex <= DesignatedEndIndex) { 2000 // Recurse to check later designated subobjects. 2001 QualType ElementType = AT->getElementType(); 2002 Index = OldIndex; 2003 2004 ElementEntity.setElementIndex(ElementIndex); 2005 if (CheckDesignatedInitializer(ElementEntity, IList, DIE, DesigIdx + 1, 2006 ElementType, 0, 0, Index, 2007 StructuredList, ElementIndex, 2008 (DesignatedStartIndex == DesignatedEndIndex), 2009 false)) 2010 return true; 2011 2012 // Move to the next index in the array that we'll be initializing. 2013 ++DesignatedStartIndex; 2014 ElementIndex = DesignatedStartIndex.getZExtValue(); 2015 } 2016 2017 // If this the first designator, our caller will continue checking 2018 // the rest of this array subobject. 2019 if (IsFirstDesignator) { 2020 if (NextElementIndex) 2021 *NextElementIndex = DesignatedStartIndex; 2022 StructuredIndex = ElementIndex; 2023 return false; 2024 } 2025 2026 if (!FinishSubobjectInit) 2027 return false; 2028 2029 // Check the remaining elements within this array subobject. 2030 bool prevHadError = hadError; 2031 CheckArrayType(Entity, IList, CurrentObjectType, DesignatedStartIndex, 2032 /*SubobjectIsDesignatorContext=*/false, Index, 2033 StructuredList, ElementIndex); 2034 return hadError && !prevHadError; 2035} 2036 2037// Get the structured initializer list for a subobject of type 2038// @p CurrentObjectType. 2039InitListExpr * 2040InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index, 2041 QualType CurrentObjectType, 2042 InitListExpr *StructuredList, 2043 unsigned StructuredIndex, 2044 SourceRange InitRange) { 2045 if (VerifyOnly) 2046 return 0; // No structured list in verification-only mode. 2047 Expr *ExistingInit = 0; 2048 if (!StructuredList) 2049 ExistingInit = SyntacticToSemantic.lookup(IList); 2050 else if (StructuredIndex < StructuredList->getNumInits()) 2051 ExistingInit = StructuredList->getInit(StructuredIndex); 2052 2053 if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit)) 2054 return Result; 2055 2056 if (ExistingInit) { 2057 // We are creating an initializer list that initializes the 2058 // subobjects of the current object, but there was already an 2059 // initialization that completely initialized the current 2060 // subobject, e.g., by a compound literal: 2061 // 2062 // struct X { int a, b; }; 2063 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 }; 2064 // 2065 // Here, xs[0].a == 0 and xs[0].b == 3, since the second, 2066 // designated initializer re-initializes the whole 2067 // subobject [0], overwriting previous initializers. 2068 SemaRef.Diag(InitRange.getBegin(), 2069 diag::warn_subobject_initializer_overrides) 2070 << InitRange; 2071 SemaRef.Diag(ExistingInit->getSourceRange().getBegin(), 2072 diag::note_previous_initializer) 2073 << /*FIXME:has side effects=*/0 2074 << ExistingInit->getSourceRange(); 2075 } 2076 2077 InitListExpr *Result 2078 = new (SemaRef.Context) InitListExpr(SemaRef.Context, 2079 InitRange.getBegin(), 0, 0, 2080 InitRange.getEnd()); 2081 2082 QualType ResultType = CurrentObjectType; 2083 if (!ResultType->isArrayType()) 2084 ResultType = ResultType.getNonLValueExprType(SemaRef.Context); 2085 Result->setType(ResultType); 2086 2087 // Pre-allocate storage for the structured initializer list. 2088 unsigned NumElements = 0; 2089 unsigned NumInits = 0; 2090 bool GotNumInits = false; 2091 if (!StructuredList) { 2092 NumInits = IList->getNumInits(); 2093 GotNumInits = true; 2094 } else if (Index < IList->getNumInits()) { 2095 if (InitListExpr *SubList = dyn_cast<InitListExpr>(IList->getInit(Index))) { 2096 NumInits = SubList->getNumInits(); 2097 GotNumInits = true; 2098 } 2099 } 2100 2101 if (const ArrayType *AType 2102 = SemaRef.Context.getAsArrayType(CurrentObjectType)) { 2103 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) { 2104 NumElements = CAType->getSize().getZExtValue(); 2105 // Simple heuristic so that we don't allocate a very large 2106 // initializer with many empty entries at the end. 2107 if (GotNumInits && NumElements > NumInits) 2108 NumElements = 0; 2109 } 2110 } else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>()) 2111 NumElements = VType->getNumElements(); 2112 else if (const RecordType *RType = CurrentObjectType->getAs<RecordType>()) { 2113 RecordDecl *RDecl = RType->getDecl(); 2114 if (RDecl->isUnion()) 2115 NumElements = 1; 2116 else 2117 NumElements = std::distance(RDecl->field_begin(), 2118 RDecl->field_end()); 2119 } 2120 2121 Result->reserveInits(SemaRef.Context, NumElements); 2122 2123 // Link this new initializer list into the structured initializer 2124 // lists. 2125 if (StructuredList) 2126 StructuredList->updateInit(SemaRef.Context, StructuredIndex, Result); 2127 else { 2128 Result->setSyntacticForm(IList); 2129 SyntacticToSemantic[IList] = Result; 2130 } 2131 2132 return Result; 2133} 2134 2135/// Update the initializer at index @p StructuredIndex within the 2136/// structured initializer list to the value @p expr. 2137void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList, 2138 unsigned &StructuredIndex, 2139 Expr *expr) { 2140 // No structured initializer list to update 2141 if (!StructuredList) 2142 return; 2143 2144 if (Expr *PrevInit = StructuredList->updateInit(SemaRef.Context, 2145 StructuredIndex, expr)) { 2146 // This initializer overwrites a previous initializer. Warn. 2147 SemaRef.Diag(expr->getSourceRange().getBegin(), 2148 diag::warn_initializer_overrides) 2149 << expr->getSourceRange(); 2150 SemaRef.Diag(PrevInit->getSourceRange().getBegin(), 2151 diag::note_previous_initializer) 2152 << /*FIXME:has side effects=*/0 2153 << PrevInit->getSourceRange(); 2154 } 2155 2156 ++StructuredIndex; 2157} 2158 2159/// Check that the given Index expression is a valid array designator 2160/// value. This is essentially just a wrapper around 2161/// VerifyIntegerConstantExpression that also checks for negative values 2162/// and produces a reasonable diagnostic if there is a 2163/// failure. Returns the index expression, possibly with an implicit cast 2164/// added, on success. If everything went okay, Value will receive the 2165/// value of the constant expression. 2166static ExprResult 2167CheckArrayDesignatorExpr(Sema &S, Expr *Index, llvm::APSInt &Value) { 2168 SourceLocation Loc = Index->getSourceRange().getBegin(); 2169 2170 // Make sure this is an integer constant expression. 2171 ExprResult Result = S.VerifyIntegerConstantExpression(Index, &Value); 2172 if (Result.isInvalid()) 2173 return Result; 2174 2175 if (Value.isSigned() && Value.isNegative()) 2176 return S.Diag(Loc, diag::err_array_designator_negative) 2177 << Value.toString(10) << Index->getSourceRange(); 2178 2179 Value.setIsUnsigned(true); 2180 return Result; 2181} 2182 2183ExprResult Sema::ActOnDesignatedInitializer(Designation &Desig, 2184 SourceLocation Loc, 2185 bool GNUSyntax, 2186 ExprResult Init) { 2187 typedef DesignatedInitExpr::Designator ASTDesignator; 2188 2189 bool Invalid = false; 2190 SmallVector<ASTDesignator, 32> Designators; 2191 SmallVector<Expr *, 32> InitExpressions; 2192 2193 // Build designators and check array designator expressions. 2194 for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) { 2195 const Designator &D = Desig.getDesignator(Idx); 2196 switch (D.getKind()) { 2197 case Designator::FieldDesignator: 2198 Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(), 2199 D.getFieldLoc())); 2200 break; 2201 2202 case Designator::ArrayDesignator: { 2203 Expr *Index = static_cast<Expr *>(D.getArrayIndex()); 2204 llvm::APSInt IndexValue; 2205 if (!Index->isTypeDependent() && !Index->isValueDependent()) 2206 Index = CheckArrayDesignatorExpr(*this, Index, IndexValue).take(); 2207 if (!Index) 2208 Invalid = true; 2209 else { 2210 Designators.push_back(ASTDesignator(InitExpressions.size(), 2211 D.getLBracketLoc(), 2212 D.getRBracketLoc())); 2213 InitExpressions.push_back(Index); 2214 } 2215 break; 2216 } 2217 2218 case Designator::ArrayRangeDesignator: { 2219 Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart()); 2220 Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd()); 2221 llvm::APSInt StartValue; 2222 llvm::APSInt EndValue; 2223 bool StartDependent = StartIndex->isTypeDependent() || 2224 StartIndex->isValueDependent(); 2225 bool EndDependent = EndIndex->isTypeDependent() || 2226 EndIndex->isValueDependent(); 2227 if (!StartDependent) 2228 StartIndex = 2229 CheckArrayDesignatorExpr(*this, StartIndex, StartValue).take(); 2230 if (!EndDependent) 2231 EndIndex = CheckArrayDesignatorExpr(*this, EndIndex, EndValue).take(); 2232 2233 if (!StartIndex || !EndIndex) 2234 Invalid = true; 2235 else { 2236 // Make sure we're comparing values with the same bit width. 2237 if (StartDependent || EndDependent) { 2238 // Nothing to compute. 2239 } else if (StartValue.getBitWidth() > EndValue.getBitWidth()) 2240 EndValue = EndValue.extend(StartValue.getBitWidth()); 2241 else if (StartValue.getBitWidth() < EndValue.getBitWidth()) 2242 StartValue = StartValue.extend(EndValue.getBitWidth()); 2243 2244 if (!StartDependent && !EndDependent && EndValue < StartValue) { 2245 Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range) 2246 << StartValue.toString(10) << EndValue.toString(10) 2247 << StartIndex->getSourceRange() << EndIndex->getSourceRange(); 2248 Invalid = true; 2249 } else { 2250 Designators.push_back(ASTDesignator(InitExpressions.size(), 2251 D.getLBracketLoc(), 2252 D.getEllipsisLoc(), 2253 D.getRBracketLoc())); 2254 InitExpressions.push_back(StartIndex); 2255 InitExpressions.push_back(EndIndex); 2256 } 2257 } 2258 break; 2259 } 2260 } 2261 } 2262 2263 if (Invalid || Init.isInvalid()) 2264 return ExprError(); 2265 2266 // Clear out the expressions within the designation. 2267 Desig.ClearExprs(*this); 2268 2269 DesignatedInitExpr *DIE 2270 = DesignatedInitExpr::Create(Context, 2271 Designators.data(), Designators.size(), 2272 InitExpressions.data(), InitExpressions.size(), 2273 Loc, GNUSyntax, Init.takeAs<Expr>()); 2274 2275 if (!getLangOptions().C99) 2276 Diag(DIE->getLocStart(), diag::ext_designated_init) 2277 << DIE->getSourceRange(); 2278 2279 return Owned(DIE); 2280} 2281 2282//===----------------------------------------------------------------------===// 2283// Initialization entity 2284//===----------------------------------------------------------------------===// 2285 2286InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index, 2287 const InitializedEntity &Parent) 2288 : Parent(&Parent), Index(Index) 2289{ 2290 if (const ArrayType *AT = Context.getAsArrayType(Parent.getType())) { 2291 Kind = EK_ArrayElement; 2292 Type = AT->getElementType(); 2293 } else if (const VectorType *VT = Parent.getType()->getAs<VectorType>()) { 2294 Kind = EK_VectorElement; 2295 Type = VT->getElementType(); 2296 } else { 2297 const ComplexType *CT = Parent.getType()->getAs<ComplexType>(); 2298 assert(CT && "Unexpected type"); 2299 Kind = EK_ComplexElement; 2300 Type = CT->getElementType(); 2301 } 2302} 2303 2304InitializedEntity InitializedEntity::InitializeBase(ASTContext &Context, 2305 CXXBaseSpecifier *Base, 2306 bool IsInheritedVirtualBase) 2307{ 2308 InitializedEntity Result; 2309 Result.Kind = EK_Base; 2310 Result.Base = reinterpret_cast<uintptr_t>(Base); 2311 if (IsInheritedVirtualBase) 2312 Result.Base |= 0x01; 2313 2314 Result.Type = Base->getType(); 2315 return Result; 2316} 2317 2318DeclarationName InitializedEntity::getName() const { 2319 switch (getKind()) { 2320 case EK_Parameter: { 2321 ParmVarDecl *D = reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1); 2322 return (D ? D->getDeclName() : DeclarationName()); 2323 } 2324 2325 case EK_Variable: 2326 case EK_Member: 2327 return VariableOrMember->getDeclName(); 2328 2329 case EK_LambdaCapture: 2330 return Capture.Var->getDeclName(); 2331 2332 case EK_Result: 2333 case EK_Exception: 2334 case EK_New: 2335 case EK_Temporary: 2336 case EK_Base: 2337 case EK_Delegating: 2338 case EK_ArrayElement: 2339 case EK_VectorElement: 2340 case EK_ComplexElement: 2341 case EK_BlockElement: 2342 return DeclarationName(); 2343 } 2344 2345 llvm_unreachable("Invalid EntityKind!"); 2346} 2347 2348DeclaratorDecl *InitializedEntity::getDecl() const { 2349 switch (getKind()) { 2350 case EK_Variable: 2351 case EK_Member: 2352 return VariableOrMember; 2353 2354 case EK_Parameter: 2355 return reinterpret_cast<ParmVarDecl*>(Parameter & ~0x1); 2356 2357 case EK_Result: 2358 case EK_Exception: 2359 case EK_New: 2360 case EK_Temporary: 2361 case EK_Base: 2362 case EK_Delegating: 2363 case EK_ArrayElement: 2364 case EK_VectorElement: 2365 case EK_ComplexElement: 2366 case EK_BlockElement: 2367 case EK_LambdaCapture: 2368 return 0; 2369 } 2370 2371 llvm_unreachable("Invalid EntityKind!"); 2372} 2373 2374bool InitializedEntity::allowsNRVO() const { 2375 switch (getKind()) { 2376 case EK_Result: 2377 case EK_Exception: 2378 return LocAndNRVO.NRVO; 2379 2380 case EK_Variable: 2381 case EK_Parameter: 2382 case EK_Member: 2383 case EK_New: 2384 case EK_Temporary: 2385 case EK_Base: 2386 case EK_Delegating: 2387 case EK_ArrayElement: 2388 case EK_VectorElement: 2389 case EK_ComplexElement: 2390 case EK_BlockElement: 2391 case EK_LambdaCapture: 2392 break; 2393 } 2394 2395 return false; 2396} 2397 2398//===----------------------------------------------------------------------===// 2399// Initialization sequence 2400//===----------------------------------------------------------------------===// 2401 2402void InitializationSequence::Step::Destroy() { 2403 switch (Kind) { 2404 case SK_ResolveAddressOfOverloadedFunction: 2405 case SK_CastDerivedToBaseRValue: 2406 case SK_CastDerivedToBaseXValue: 2407 case SK_CastDerivedToBaseLValue: 2408 case SK_BindReference: 2409 case SK_BindReferenceToTemporary: 2410 case SK_ExtraneousCopyToTemporary: 2411 case SK_UserConversion: 2412 case SK_QualificationConversionRValue: 2413 case SK_QualificationConversionXValue: 2414 case SK_QualificationConversionLValue: 2415 case SK_ListInitialization: 2416 case SK_ListConstructorCall: 2417 case SK_UnwrapInitList: 2418 case SK_RewrapInitList: 2419 case SK_ConstructorInitialization: 2420 case SK_ZeroInitialization: 2421 case SK_CAssignment: 2422 case SK_StringInit: 2423 case SK_ObjCObjectConversion: 2424 case SK_ArrayInit: 2425 case SK_ParenthesizedArrayInit: 2426 case SK_PassByIndirectCopyRestore: 2427 case SK_PassByIndirectRestore: 2428 case SK_ProduceObjCObject: 2429 case SK_StdInitializerList: 2430 break; 2431 2432 case SK_ConversionSequence: 2433 delete ICS; 2434 } 2435} 2436 2437bool InitializationSequence::isDirectReferenceBinding() const { 2438 return !Steps.empty() && Steps.back().Kind == SK_BindReference; 2439} 2440 2441bool InitializationSequence::isAmbiguous() const { 2442 if (!Failed()) 2443 return false; 2444 2445 switch (getFailureKind()) { 2446 case FK_TooManyInitsForReference: 2447 case FK_ArrayNeedsInitList: 2448 case FK_ArrayNeedsInitListOrStringLiteral: 2449 case FK_AddressOfOverloadFailed: // FIXME: Could do better 2450 case FK_NonConstLValueReferenceBindingToTemporary: 2451 case FK_NonConstLValueReferenceBindingToUnrelated: 2452 case FK_RValueReferenceBindingToLValue: 2453 case FK_ReferenceInitDropsQualifiers: 2454 case FK_ReferenceInitFailed: 2455 case FK_ConversionFailed: 2456 case FK_ConversionFromPropertyFailed: 2457 case FK_TooManyInitsForScalar: 2458 case FK_ReferenceBindingToInitList: 2459 case FK_InitListBadDestinationType: 2460 case FK_DefaultInitOfConst: 2461 case FK_Incomplete: 2462 case FK_ArrayTypeMismatch: 2463 case FK_NonConstantArrayInit: 2464 case FK_ListInitializationFailed: 2465 case FK_VariableLengthArrayHasInitializer: 2466 case FK_PlaceholderType: 2467 case FK_InitListElementCopyFailure: 2468 return false; 2469 2470 case FK_ReferenceInitOverloadFailed: 2471 case FK_UserConversionOverloadFailed: 2472 case FK_ConstructorOverloadFailed: 2473 case FK_ListConstructorOverloadFailed: 2474 return FailedOverloadResult == OR_Ambiguous; 2475 } 2476 2477 llvm_unreachable("Invalid EntityKind!"); 2478} 2479 2480bool InitializationSequence::isConstructorInitialization() const { 2481 return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization; 2482} 2483 2484void 2485InitializationSequence 2486::AddAddressOverloadResolutionStep(FunctionDecl *Function, 2487 DeclAccessPair Found, 2488 bool HadMultipleCandidates) { 2489 Step S; 2490 S.Kind = SK_ResolveAddressOfOverloadedFunction; 2491 S.Type = Function->getType(); 2492 S.Function.HadMultipleCandidates = HadMultipleCandidates; 2493 S.Function.Function = Function; 2494 S.Function.FoundDecl = Found; 2495 Steps.push_back(S); 2496} 2497 2498void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType, 2499 ExprValueKind VK) { 2500 Step S; 2501 switch (VK) { 2502 case VK_RValue: S.Kind = SK_CastDerivedToBaseRValue; break; 2503 case VK_XValue: S.Kind = SK_CastDerivedToBaseXValue; break; 2504 case VK_LValue: S.Kind = SK_CastDerivedToBaseLValue; break; 2505 } 2506 S.Type = BaseType; 2507 Steps.push_back(S); 2508} 2509 2510void InitializationSequence::AddReferenceBindingStep(QualType T, 2511 bool BindingTemporary) { 2512 Step S; 2513 S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference; 2514 S.Type = T; 2515 Steps.push_back(S); 2516} 2517 2518void InitializationSequence::AddExtraneousCopyToTemporary(QualType T) { 2519 Step S; 2520 S.Kind = SK_ExtraneousCopyToTemporary; 2521 S.Type = T; 2522 Steps.push_back(S); 2523} 2524 2525void 2526InitializationSequence::AddUserConversionStep(FunctionDecl *Function, 2527 DeclAccessPair FoundDecl, 2528 QualType T, 2529 bool HadMultipleCandidates) { 2530 Step S; 2531 S.Kind = SK_UserConversion; 2532 S.Type = T; 2533 S.Function.HadMultipleCandidates = HadMultipleCandidates; 2534 S.Function.Function = Function; 2535 S.Function.FoundDecl = FoundDecl; 2536 Steps.push_back(S); 2537} 2538 2539void InitializationSequence::AddQualificationConversionStep(QualType Ty, 2540 ExprValueKind VK) { 2541 Step S; 2542 S.Kind = SK_QualificationConversionRValue; // work around a gcc warning 2543 switch (VK) { 2544 case VK_RValue: 2545 S.Kind = SK_QualificationConversionRValue; 2546 break; 2547 case VK_XValue: 2548 S.Kind = SK_QualificationConversionXValue; 2549 break; 2550 case VK_LValue: 2551 S.Kind = SK_QualificationConversionLValue; 2552 break; 2553 } 2554 S.Type = Ty; 2555 Steps.push_back(S); 2556} 2557 2558void InitializationSequence::AddConversionSequenceStep( 2559 const ImplicitConversionSequence &ICS, 2560 QualType T) { 2561 Step S; 2562 S.Kind = SK_ConversionSequence; 2563 S.Type = T; 2564 S.ICS = new ImplicitConversionSequence(ICS); 2565 Steps.push_back(S); 2566} 2567 2568void InitializationSequence::AddListInitializationStep(QualType T) { 2569 Step S; 2570 S.Kind = SK_ListInitialization; 2571 S.Type = T; 2572 Steps.push_back(S); 2573} 2574 2575void 2576InitializationSequence 2577::AddConstructorInitializationStep(CXXConstructorDecl *Constructor, 2578 AccessSpecifier Access, 2579 QualType T, 2580 bool HadMultipleCandidates, 2581 bool FromInitList, bool AsInitList) { 2582 Step S; 2583 S.Kind = FromInitList && !AsInitList ? SK_ListConstructorCall 2584 : SK_ConstructorInitialization; 2585 S.Type = T; 2586 S.Function.HadMultipleCandidates = HadMultipleCandidates; 2587 S.Function.Function = Constructor; 2588 S.Function.FoundDecl = DeclAccessPair::make(Constructor, Access); 2589 Steps.push_back(S); 2590} 2591 2592void InitializationSequence::AddZeroInitializationStep(QualType T) { 2593 Step S; 2594 S.Kind = SK_ZeroInitialization; 2595 S.Type = T; 2596 Steps.push_back(S); 2597} 2598 2599void InitializationSequence::AddCAssignmentStep(QualType T) { 2600 Step S; 2601 S.Kind = SK_CAssignment; 2602 S.Type = T; 2603 Steps.push_back(S); 2604} 2605 2606void InitializationSequence::AddStringInitStep(QualType T) { 2607 Step S; 2608 S.Kind = SK_StringInit; 2609 S.Type = T; 2610 Steps.push_back(S); 2611} 2612 2613void InitializationSequence::AddObjCObjectConversionStep(QualType T) { 2614 Step S; 2615 S.Kind = SK_ObjCObjectConversion; 2616 S.Type = T; 2617 Steps.push_back(S); 2618} 2619 2620void InitializationSequence::AddArrayInitStep(QualType T) { 2621 Step S; 2622 S.Kind = SK_ArrayInit; 2623 S.Type = T; 2624 Steps.push_back(S); 2625} 2626 2627void InitializationSequence::AddParenthesizedArrayInitStep(QualType T) { 2628 Step S; 2629 S.Kind = SK_ParenthesizedArrayInit; 2630 S.Type = T; 2631 Steps.push_back(S); 2632} 2633 2634void InitializationSequence::AddPassByIndirectCopyRestoreStep(QualType type, 2635 bool shouldCopy) { 2636 Step s; 2637 s.Kind = (shouldCopy ? SK_PassByIndirectCopyRestore 2638 : SK_PassByIndirectRestore); 2639 s.Type = type; 2640 Steps.push_back(s); 2641} 2642 2643void InitializationSequence::AddProduceObjCObjectStep(QualType T) { 2644 Step S; 2645 S.Kind = SK_ProduceObjCObject; 2646 S.Type = T; 2647 Steps.push_back(S); 2648} 2649 2650void InitializationSequence::AddStdInitializerListConstructionStep(QualType T) { 2651 Step S; 2652 S.Kind = SK_StdInitializerList; 2653 S.Type = T; 2654 Steps.push_back(S); 2655} 2656 2657void InitializationSequence::RewrapReferenceInitList(QualType T, 2658 InitListExpr *Syntactic) { 2659 assert(Syntactic->getNumInits() == 1 && 2660 "Can only rewrap trivial init lists."); 2661 Step S; 2662 S.Kind = SK_UnwrapInitList; 2663 S.Type = Syntactic->getInit(0)->getType(); 2664 Steps.insert(Steps.begin(), S); 2665 2666 S.Kind = SK_RewrapInitList; 2667 S.Type = T; 2668 S.WrappingSyntacticList = Syntactic; 2669 Steps.push_back(S); 2670} 2671 2672void InitializationSequence::SetOverloadFailure(FailureKind Failure, 2673 OverloadingResult Result) { 2674 setSequenceKind(FailedSequence); 2675 this->Failure = Failure; 2676 this->FailedOverloadResult = Result; 2677} 2678 2679//===----------------------------------------------------------------------===// 2680// Attempt initialization 2681//===----------------------------------------------------------------------===// 2682 2683static void MaybeProduceObjCObject(Sema &S, 2684 InitializationSequence &Sequence, 2685 const InitializedEntity &Entity) { 2686 if (!S.getLangOptions().ObjCAutoRefCount) return; 2687 2688 /// When initializing a parameter, produce the value if it's marked 2689 /// __attribute__((ns_consumed)). 2690 if (Entity.getKind() == InitializedEntity::EK_Parameter) { 2691 if (!Entity.isParameterConsumed()) 2692 return; 2693 2694 assert(Entity.getType()->isObjCRetainableType() && 2695 "consuming an object of unretainable type?"); 2696 Sequence.AddProduceObjCObjectStep(Entity.getType()); 2697 2698 /// When initializing a return value, if the return type is a 2699 /// retainable type, then returns need to immediately retain the 2700 /// object. If an autorelease is required, it will be done at the 2701 /// last instant. 2702 } else if (Entity.getKind() == InitializedEntity::EK_Result) { 2703 if (!Entity.getType()->isObjCRetainableType()) 2704 return; 2705 2706 Sequence.AddProduceObjCObjectStep(Entity.getType()); 2707 } 2708} 2709 2710/// \brief When initializing from init list via constructor, deal with the 2711/// empty init list and std::initializer_list special cases. 2712/// 2713/// \return True if this was a special case, false otherwise. 2714static bool TryListConstructionSpecialCases(Sema &S, 2715 InitListExpr *List, 2716 CXXRecordDecl *DestRecordDecl, 2717 QualType DestType, 2718 InitializationSequence &Sequence) { 2719 // C++11 [dcl.init.list]p3: 2720 // List-initialization of an object or reference of type T is defined as 2721 // follows: 2722 // - If T is an aggregate, aggregate initialization is performed. 2723 if (DestType->isAggregateType()) 2724 return false; 2725 2726 // - Otherwise, if the initializer list has no elements and T is a class 2727 // type with a default constructor, the object is value-initialized. 2728 if (List->getNumInits() == 0) { 2729 if (CXXConstructorDecl *DefaultConstructor = 2730 S.LookupDefaultConstructor(DestRecordDecl)) { 2731 if (DefaultConstructor->isDeleted() || 2732 S.isFunctionConsideredUnavailable(DefaultConstructor)) { 2733 // Fake an overload resolution failure. 2734 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 2735 DeclAccessPair FoundDecl = DeclAccessPair::make(DefaultConstructor, 2736 DefaultConstructor->getAccess()); 2737 if (FunctionTemplateDecl *ConstructorTmpl = 2738 dyn_cast<FunctionTemplateDecl>(DefaultConstructor)) 2739 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2740 /*ExplicitArgs*/ 0, 2741 ArrayRef<Expr*>(), CandidateSet, 2742 /*SuppressUserConversions*/ false); 2743 else 2744 S.AddOverloadCandidate(DefaultConstructor, FoundDecl, 2745 ArrayRef<Expr*>(), CandidateSet, 2746 /*SuppressUserConversions*/ false); 2747 Sequence.SetOverloadFailure( 2748 InitializationSequence::FK_ListConstructorOverloadFailed, 2749 OR_Deleted); 2750 } else 2751 Sequence.AddConstructorInitializationStep(DefaultConstructor, 2752 DefaultConstructor->getAccess(), 2753 DestType, 2754 /*MultipleCandidates=*/false, 2755 /*FromInitList=*/true, 2756 /*AsInitList=*/false); 2757 return true; 2758 } 2759 } 2760 2761 // - Otherwise, if T is a specialization of std::initializer_list, [...] 2762 QualType E; 2763 if (S.isStdInitializerList(DestType, &E)) { 2764 // Check that each individual element can be copy-constructed. But since we 2765 // have no place to store further information, we'll recalculate everything 2766 // later. 2767 InitializedEntity HiddenArray = InitializedEntity::InitializeTemporary( 2768 S.Context.getConstantArrayType(E, 2769 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()), 2770 List->getNumInits()), 2771 ArrayType::Normal, 0)); 2772 InitializedEntity Element = InitializedEntity::InitializeElement(S.Context, 2773 0, HiddenArray); 2774 for (unsigned i = 0, n = List->getNumInits(); i < n; ++i) { 2775 Element.setElementIndex(i); 2776 if (!S.CanPerformCopyInitialization(Element, List->getInit(i))) { 2777 Sequence.SetFailed( 2778 InitializationSequence::FK_InitListElementCopyFailure); 2779 return true; 2780 } 2781 } 2782 Sequence.AddStdInitializerListConstructionStep(DestType); 2783 return true; 2784 } 2785 2786 // Not a special case. 2787 return false; 2788} 2789 2790static OverloadingResult 2791ResolveConstructorOverload(Sema &S, SourceLocation DeclLoc, 2792 Expr **Args, unsigned NumArgs, 2793 OverloadCandidateSet &CandidateSet, 2794 DeclContext::lookup_iterator Con, 2795 DeclContext::lookup_iterator ConEnd, 2796 OverloadCandidateSet::iterator &Best, 2797 bool CopyInitializing, bool AllowExplicit, 2798 bool OnlyListConstructors, bool InitListSyntax) { 2799 CandidateSet.clear(); 2800 2801 for (; Con != ConEnd; ++Con) { 2802 NamedDecl *D = *Con; 2803 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2804 bool SuppressUserConversions = false; 2805 2806 // Find the constructor (which may be a template). 2807 CXXConstructorDecl *Constructor = 0; 2808 FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D); 2809 if (ConstructorTmpl) 2810 Constructor = cast<CXXConstructorDecl>( 2811 ConstructorTmpl->getTemplatedDecl()); 2812 else { 2813 Constructor = cast<CXXConstructorDecl>(D); 2814 2815 // If we're performing copy initialization using a copy constructor, we 2816 // suppress user-defined conversions on the arguments. We do the same for 2817 // move constructors. 2818 if ((CopyInitializing || (InitListSyntax && NumArgs == 1)) && 2819 Constructor->isCopyOrMoveConstructor()) 2820 SuppressUserConversions = true; 2821 } 2822 2823 if (!Constructor->isInvalidDecl() && 2824 (AllowExplicit || !Constructor->isExplicit()) && 2825 (!OnlyListConstructors || S.isInitListConstructor(Constructor))) { 2826 if (ConstructorTmpl) 2827 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2828 /*ExplicitArgs*/ 0, 2829 llvm::makeArrayRef(Args, NumArgs), 2830 CandidateSet, SuppressUserConversions); 2831 else { 2832 // C++ [over.match.copy]p1: 2833 // - When initializing a temporary to be bound to the first parameter 2834 // of a constructor that takes a reference to possibly cv-qualified 2835 // T as its first argument, called with a single argument in the 2836 // context of direct-initialization, explicit conversion functions 2837 // are also considered. 2838 bool AllowExplicitConv = AllowExplicit && !CopyInitializing && 2839 NumArgs == 1 && 2840 Constructor->isCopyOrMoveConstructor(); 2841 S.AddOverloadCandidate(Constructor, FoundDecl, 2842 llvm::makeArrayRef(Args, NumArgs), CandidateSet, 2843 SuppressUserConversions, 2844 /*PartialOverloading=*/false, 2845 /*AllowExplicit=*/AllowExplicitConv); 2846 } 2847 } 2848 } 2849 2850 // Perform overload resolution and return the result. 2851 return CandidateSet.BestViableFunction(S, DeclLoc, Best); 2852} 2853 2854/// \brief Attempt initialization by constructor (C++ [dcl.init]), which 2855/// enumerates the constructors of the initialized entity and performs overload 2856/// resolution to select the best. 2857/// If InitListSyntax is true, this is list-initialization of a non-aggregate 2858/// class type. 2859static void TryConstructorInitialization(Sema &S, 2860 const InitializedEntity &Entity, 2861 const InitializationKind &Kind, 2862 Expr **Args, unsigned NumArgs, 2863 QualType DestType, 2864 InitializationSequence &Sequence, 2865 bool InitListSyntax = false) { 2866 assert((!InitListSyntax || (NumArgs == 1 && isa<InitListExpr>(Args[0]))) && 2867 "InitListSyntax must come with a single initializer list argument."); 2868 2869 // Check constructor arguments for self reference. 2870 if (DeclaratorDecl *DD = Entity.getDecl()) 2871 // Parameters arguments are occassionially constructed with itself, 2872 // for instance, in recursive functions. Skip them. 2873 if (!isa<ParmVarDecl>(DD)) 2874 for (unsigned i = 0; i < NumArgs; ++i) 2875 S.CheckSelfReference(DD, Args[i]); 2876 2877 // The type we're constructing needs to be complete. 2878 if (S.RequireCompleteType(Kind.getLocation(), DestType, 0)) { 2879 Sequence.SetFailed(InitializationSequence::FK_Incomplete); 2880 return; 2881 } 2882 2883 const RecordType *DestRecordType = DestType->getAs<RecordType>(); 2884 assert(DestRecordType && "Constructor initialization requires record type"); 2885 CXXRecordDecl *DestRecordDecl 2886 = cast<CXXRecordDecl>(DestRecordType->getDecl()); 2887 2888 if (InitListSyntax && 2889 TryListConstructionSpecialCases(S, cast<InitListExpr>(Args[0]), 2890 DestRecordDecl, DestType, Sequence)) 2891 return; 2892 2893 // Build the candidate set directly in the initialization sequence 2894 // structure, so that it will persist if we fail. 2895 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 2896 2897 // Determine whether we are allowed to call explicit constructors or 2898 // explicit conversion operators. 2899 bool AllowExplicit = Kind.AllowExplicit(); 2900 bool CopyInitialization = Kind.getKind() == InitializationKind::IK_Copy; 2901 2902 // - Otherwise, if T is a class type, constructors are considered. The 2903 // applicable constructors are enumerated, and the best one is chosen 2904 // through overload resolution. 2905 DeclContext::lookup_iterator ConStart, ConEnd; 2906 llvm::tie(ConStart, ConEnd) = S.LookupConstructors(DestRecordDecl); 2907 2908 OverloadingResult Result = OR_No_Viable_Function; 2909 OverloadCandidateSet::iterator Best; 2910 bool AsInitializerList = false; 2911 2912 // C++11 [over.match.list]p1: 2913 // When objects of non-aggregate type T are list-initialized, overload 2914 // resolution selects the constructor in two phases: 2915 // - Initially, the candidate functions are the initializer-list 2916 // constructors of the class T and the argument list consists of the 2917 // initializer list as a single argument. 2918 if (InitListSyntax) { 2919 AsInitializerList = true; 2920 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args, NumArgs, 2921 CandidateSet, ConStart, ConEnd, Best, 2922 CopyInitialization, AllowExplicit, 2923 /*OnlyListConstructor=*/true, 2924 InitListSyntax); 2925 2926 // Time to unwrap the init list. 2927 InitListExpr *ILE = cast<InitListExpr>(Args[0]); 2928 Args = ILE->getInits(); 2929 NumArgs = ILE->getNumInits(); 2930 } 2931 2932 // C++11 [over.match.list]p1: 2933 // - If no viable initializer-list constructor is found, overload resolution 2934 // is performed again, where the candidate functions are all the 2935 // constructors of the class T nad the argument list consists of the 2936 // elements of the initializer list. 2937 if (Result == OR_No_Viable_Function) { 2938 AsInitializerList = false; 2939 Result = ResolveConstructorOverload(S, Kind.getLocation(), Args, NumArgs, 2940 CandidateSet, ConStart, ConEnd, Best, 2941 CopyInitialization, AllowExplicit, 2942 /*OnlyListConstructors=*/false, 2943 InitListSyntax); 2944 } 2945 if (Result) { 2946 Sequence.SetOverloadFailure(InitListSyntax ? 2947 InitializationSequence::FK_ListConstructorOverloadFailed : 2948 InitializationSequence::FK_ConstructorOverloadFailed, 2949 Result); 2950 return; 2951 } 2952 2953 // C++0x [dcl.init]p6: 2954 // If a program calls for the default initialization of an object 2955 // of a const-qualified type T, T shall be a class type with a 2956 // user-provided default constructor. 2957 if (Kind.getKind() == InitializationKind::IK_Default && 2958 Entity.getType().isConstQualified() && 2959 cast<CXXConstructorDecl>(Best->Function)->isImplicit()) { 2960 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst); 2961 return; 2962 } 2963 2964 // Add the constructor initialization step. Any cv-qualification conversion is 2965 // subsumed by the initialization. 2966 bool HadMultipleCandidates = (CandidateSet.size() > 1); 2967 CXXConstructorDecl *CtorDecl = cast<CXXConstructorDecl>(Best->Function); 2968 Sequence.AddConstructorInitializationStep(CtorDecl, 2969 Best->FoundDecl.getAccess(), 2970 DestType, HadMultipleCandidates, 2971 InitListSyntax, AsInitializerList); 2972} 2973 2974static bool 2975ResolveOverloadedFunctionForReferenceBinding(Sema &S, 2976 Expr *Initializer, 2977 QualType &SourceType, 2978 QualType &UnqualifiedSourceType, 2979 QualType UnqualifiedTargetType, 2980 InitializationSequence &Sequence) { 2981 if (S.Context.getCanonicalType(UnqualifiedSourceType) == 2982 S.Context.OverloadTy) { 2983 DeclAccessPair Found; 2984 bool HadMultipleCandidates = false; 2985 if (FunctionDecl *Fn 2986 = S.ResolveAddressOfOverloadedFunction(Initializer, 2987 UnqualifiedTargetType, 2988 false, Found, 2989 &HadMultipleCandidates)) { 2990 Sequence.AddAddressOverloadResolutionStep(Fn, Found, 2991 HadMultipleCandidates); 2992 SourceType = Fn->getType(); 2993 UnqualifiedSourceType = SourceType.getUnqualifiedType(); 2994 } else if (!UnqualifiedTargetType->isRecordType()) { 2995 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 2996 return true; 2997 } 2998 } 2999 return false; 3000} 3001 3002static void TryReferenceInitializationCore(Sema &S, 3003 const InitializedEntity &Entity, 3004 const InitializationKind &Kind, 3005 Expr *Initializer, 3006 QualType cv1T1, QualType T1, 3007 Qualifiers T1Quals, 3008 QualType cv2T2, QualType T2, 3009 Qualifiers T2Quals, 3010 InitializationSequence &Sequence); 3011 3012static void TryListInitialization(Sema &S, 3013 const InitializedEntity &Entity, 3014 const InitializationKind &Kind, 3015 InitListExpr *InitList, 3016 InitializationSequence &Sequence); 3017 3018/// \brief Attempt list initialization of a reference. 3019static void TryReferenceListInitialization(Sema &S, 3020 const InitializedEntity &Entity, 3021 const InitializationKind &Kind, 3022 InitListExpr *InitList, 3023 InitializationSequence &Sequence) 3024{ 3025 // First, catch C++03 where this isn't possible. 3026 if (!S.getLangOptions().CPlusPlus0x) { 3027 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList); 3028 return; 3029 } 3030 3031 QualType DestType = Entity.getType(); 3032 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 3033 Qualifiers T1Quals; 3034 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals); 3035 3036 // Reference initialization via an initializer list works thus: 3037 // If the initializer list consists of a single element that is 3038 // reference-related to the referenced type, bind directly to that element 3039 // (possibly creating temporaries). 3040 // Otherwise, initialize a temporary with the initializer list and 3041 // bind to that. 3042 if (InitList->getNumInits() == 1) { 3043 Expr *Initializer = InitList->getInit(0); 3044 QualType cv2T2 = Initializer->getType(); 3045 Qualifiers T2Quals; 3046 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals); 3047 3048 // If this fails, creating a temporary wouldn't work either. 3049 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2, 3050 T1, Sequence)) 3051 return; 3052 3053 SourceLocation DeclLoc = Initializer->getLocStart(); 3054 bool dummy1, dummy2, dummy3; 3055 Sema::ReferenceCompareResult RefRelationship 3056 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, dummy1, 3057 dummy2, dummy3); 3058 if (RefRelationship >= Sema::Ref_Related) { 3059 // Try to bind the reference here. 3060 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1, 3061 T1Quals, cv2T2, T2, T2Quals, Sequence); 3062 if (Sequence) 3063 Sequence.RewrapReferenceInitList(cv1T1, InitList); 3064 return; 3065 } 3066 } 3067 3068 // Not reference-related. Create a temporary and bind to that. 3069 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1); 3070 3071 TryListInitialization(S, TempEntity, Kind, InitList, Sequence); 3072 if (Sequence) { 3073 if (DestType->isRValueReferenceType() || 3074 (T1Quals.hasConst() && !T1Quals.hasVolatile())) 3075 Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true); 3076 else 3077 Sequence.SetFailed( 3078 InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary); 3079 } 3080} 3081 3082/// \brief Attempt list initialization (C++0x [dcl.init.list]) 3083static void TryListInitialization(Sema &S, 3084 const InitializedEntity &Entity, 3085 const InitializationKind &Kind, 3086 InitListExpr *InitList, 3087 InitializationSequence &Sequence) { 3088 QualType DestType = Entity.getType(); 3089 3090 // C++ doesn't allow scalar initialization with more than one argument. 3091 // But C99 complex numbers are scalars and it makes sense there. 3092 if (S.getLangOptions().CPlusPlus && DestType->isScalarType() && 3093 !DestType->isAnyComplexType() && InitList->getNumInits() > 1) { 3094 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar); 3095 return; 3096 } 3097 if (DestType->isReferenceType()) { 3098 TryReferenceListInitialization(S, Entity, Kind, InitList, Sequence); 3099 return; 3100 } 3101 if (DestType->isRecordType()) { 3102 if (S.RequireCompleteType(InitList->getLocStart(), DestType, S.PDiag())) { 3103 Sequence.SetFailed(InitializationSequence::FK_Incomplete); 3104 return; 3105 } 3106 3107 if (!DestType->isAggregateType()) { 3108 if (S.getLangOptions().CPlusPlus0x) { 3109 Expr *Arg = InitList; 3110 // A direct-initializer is not list-syntax, i.e. there's no special 3111 // treatment of "A a({1, 2});". 3112 TryConstructorInitialization(S, Entity, Kind, &Arg, 1, DestType, 3113 Sequence, 3114 Kind.getKind() != InitializationKind::IK_Direct); 3115 } else 3116 Sequence.SetFailed( 3117 InitializationSequence::FK_InitListBadDestinationType); 3118 return; 3119 } 3120 } 3121 3122 InitListChecker CheckInitList(S, Entity, InitList, 3123 DestType, /*VerifyOnly=*/true, 3124 Kind.getKind() != InitializationKind::IK_DirectList || 3125 !S.getLangOptions().CPlusPlus0x); 3126 if (CheckInitList.HadError()) { 3127 Sequence.SetFailed(InitializationSequence::FK_ListInitializationFailed); 3128 return; 3129 } 3130 3131 // Add the list initialization step with the built init list. 3132 Sequence.AddListInitializationStep(DestType); 3133} 3134 3135/// \brief Try a reference initialization that involves calling a conversion 3136/// function. 3137static OverloadingResult TryRefInitWithConversionFunction(Sema &S, 3138 const InitializedEntity &Entity, 3139 const InitializationKind &Kind, 3140 Expr *Initializer, 3141 bool AllowRValues, 3142 InitializationSequence &Sequence) { 3143 QualType DestType = Entity.getType(); 3144 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 3145 QualType T1 = cv1T1.getUnqualifiedType(); 3146 QualType cv2T2 = Initializer->getType(); 3147 QualType T2 = cv2T2.getUnqualifiedType(); 3148 3149 bool DerivedToBase; 3150 bool ObjCConversion; 3151 bool ObjCLifetimeConversion; 3152 assert(!S.CompareReferenceRelationship(Initializer->getLocStart(), 3153 T1, T2, DerivedToBase, 3154 ObjCConversion, 3155 ObjCLifetimeConversion) && 3156 "Must have incompatible references when binding via conversion"); 3157 (void)DerivedToBase; 3158 (void)ObjCConversion; 3159 (void)ObjCLifetimeConversion; 3160 3161 // Build the candidate set directly in the initialization sequence 3162 // structure, so that it will persist if we fail. 3163 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 3164 CandidateSet.clear(); 3165 3166 // Determine whether we are allowed to call explicit constructors or 3167 // explicit conversion operators. 3168 bool AllowExplicit = Kind.AllowExplicit(); 3169 bool AllowExplicitConvs = Kind.allowExplicitConversionFunctions(); 3170 3171 const RecordType *T1RecordType = 0; 3172 if (AllowRValues && (T1RecordType = T1->getAs<RecordType>()) && 3173 !S.RequireCompleteType(Kind.getLocation(), T1, 0)) { 3174 // The type we're converting to is a class type. Enumerate its constructors 3175 // to see if there is a suitable conversion. 3176 CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl()); 3177 3178 DeclContext::lookup_iterator Con, ConEnd; 3179 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(T1RecordDecl); 3180 Con != ConEnd; ++Con) { 3181 NamedDecl *D = *Con; 3182 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 3183 3184 // Find the constructor (which may be a template). 3185 CXXConstructorDecl *Constructor = 0; 3186 FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D); 3187 if (ConstructorTmpl) 3188 Constructor = cast<CXXConstructorDecl>( 3189 ConstructorTmpl->getTemplatedDecl()); 3190 else 3191 Constructor = cast<CXXConstructorDecl>(D); 3192 3193 if (!Constructor->isInvalidDecl() && 3194 Constructor->isConvertingConstructor(AllowExplicit)) { 3195 if (ConstructorTmpl) 3196 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3197 /*ExplicitArgs*/ 0, 3198 Initializer, CandidateSet, 3199 /*SuppressUserConversions=*/true); 3200 else 3201 S.AddOverloadCandidate(Constructor, FoundDecl, 3202 Initializer, CandidateSet, 3203 /*SuppressUserConversions=*/true); 3204 } 3205 } 3206 } 3207 if (T1RecordType && T1RecordType->getDecl()->isInvalidDecl()) 3208 return OR_No_Viable_Function; 3209 3210 const RecordType *T2RecordType = 0; 3211 if ((T2RecordType = T2->getAs<RecordType>()) && 3212 !S.RequireCompleteType(Kind.getLocation(), T2, 0)) { 3213 // The type we're converting from is a class type, enumerate its conversion 3214 // functions. 3215 CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl()); 3216 3217 const UnresolvedSetImpl *Conversions 3218 = T2RecordDecl->getVisibleConversionFunctions(); 3219 for (UnresolvedSetImpl::const_iterator I = Conversions->begin(), 3220 E = Conversions->end(); I != E; ++I) { 3221 NamedDecl *D = *I; 3222 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3223 if (isa<UsingShadowDecl>(D)) 3224 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3225 3226 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D); 3227 CXXConversionDecl *Conv; 3228 if (ConvTemplate) 3229 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3230 else 3231 Conv = cast<CXXConversionDecl>(D); 3232 3233 // If the conversion function doesn't return a reference type, 3234 // it can't be considered for this conversion unless we're allowed to 3235 // consider rvalues. 3236 // FIXME: Do we need to make sure that we only consider conversion 3237 // candidates with reference-compatible results? That might be needed to 3238 // break recursion. 3239 if ((AllowExplicitConvs || !Conv->isExplicit()) && 3240 (AllowRValues || Conv->getConversionType()->isLValueReferenceType())){ 3241 if (ConvTemplate) 3242 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), 3243 ActingDC, Initializer, 3244 DestType, CandidateSet); 3245 else 3246 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, 3247 Initializer, DestType, CandidateSet); 3248 } 3249 } 3250 } 3251 if (T2RecordType && T2RecordType->getDecl()->isInvalidDecl()) 3252 return OR_No_Viable_Function; 3253 3254 SourceLocation DeclLoc = Initializer->getLocStart(); 3255 3256 // Perform overload resolution. If it fails, return the failed result. 3257 OverloadCandidateSet::iterator Best; 3258 if (OverloadingResult Result 3259 = CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) 3260 return Result; 3261 3262 FunctionDecl *Function = Best->Function; 3263 3264 // This is the overload that will actually be used for the initialization, so 3265 // mark it as used. 3266 S.MarkFunctionReferenced(DeclLoc, Function); 3267 3268 // Compute the returned type of the conversion. 3269 if (isa<CXXConversionDecl>(Function)) 3270 T2 = Function->getResultType(); 3271 else 3272 T2 = cv1T1; 3273 3274 // Add the user-defined conversion step. 3275 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3276 Sequence.AddUserConversionStep(Function, Best->FoundDecl, 3277 T2.getNonLValueExprType(S.Context), 3278 HadMultipleCandidates); 3279 3280 // Determine whether we need to perform derived-to-base or 3281 // cv-qualification adjustments. 3282 ExprValueKind VK = VK_RValue; 3283 if (T2->isLValueReferenceType()) 3284 VK = VK_LValue; 3285 else if (const RValueReferenceType *RRef = T2->getAs<RValueReferenceType>()) 3286 VK = RRef->getPointeeType()->isFunctionType() ? VK_LValue : VK_XValue; 3287 3288 bool NewDerivedToBase = false; 3289 bool NewObjCConversion = false; 3290 bool NewObjCLifetimeConversion = false; 3291 Sema::ReferenceCompareResult NewRefRelationship 3292 = S.CompareReferenceRelationship(DeclLoc, T1, 3293 T2.getNonLValueExprType(S.Context), 3294 NewDerivedToBase, NewObjCConversion, 3295 NewObjCLifetimeConversion); 3296 if (NewRefRelationship == Sema::Ref_Incompatible) { 3297 // If the type we've converted to is not reference-related to the 3298 // type we're looking for, then there is another conversion step 3299 // we need to perform to produce a temporary of the right type 3300 // that we'll be binding to. 3301 ImplicitConversionSequence ICS; 3302 ICS.setStandard(); 3303 ICS.Standard = Best->FinalConversion; 3304 T2 = ICS.Standard.getToType(2); 3305 Sequence.AddConversionSequenceStep(ICS, T2); 3306 } else if (NewDerivedToBase) 3307 Sequence.AddDerivedToBaseCastStep( 3308 S.Context.getQualifiedType(T1, 3309 T2.getNonReferenceType().getQualifiers()), 3310 VK); 3311 else if (NewObjCConversion) 3312 Sequence.AddObjCObjectConversionStep( 3313 S.Context.getQualifiedType(T1, 3314 T2.getNonReferenceType().getQualifiers())); 3315 3316 if (cv1T1.getQualifiers() != T2.getNonReferenceType().getQualifiers()) 3317 Sequence.AddQualificationConversionStep(cv1T1, VK); 3318 3319 Sequence.AddReferenceBindingStep(cv1T1, !T2->isReferenceType()); 3320 return OR_Success; 3321} 3322 3323static void CheckCXX98CompatAccessibleCopy(Sema &S, 3324 const InitializedEntity &Entity, 3325 Expr *CurInitExpr); 3326 3327/// \brief Attempt reference initialization (C++0x [dcl.init.ref]) 3328static void TryReferenceInitialization(Sema &S, 3329 const InitializedEntity &Entity, 3330 const InitializationKind &Kind, 3331 Expr *Initializer, 3332 InitializationSequence &Sequence) { 3333 QualType DestType = Entity.getType(); 3334 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 3335 Qualifiers T1Quals; 3336 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals); 3337 QualType cv2T2 = Initializer->getType(); 3338 Qualifiers T2Quals; 3339 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals); 3340 3341 // If the initializer is the address of an overloaded function, try 3342 // to resolve the overloaded function. If all goes well, T2 is the 3343 // type of the resulting function. 3344 if (ResolveOverloadedFunctionForReferenceBinding(S, Initializer, cv2T2, T2, 3345 T1, Sequence)) 3346 return; 3347 3348 // Delegate everything else to a subfunction. 3349 TryReferenceInitializationCore(S, Entity, Kind, Initializer, cv1T1, T1, 3350 T1Quals, cv2T2, T2, T2Quals, Sequence); 3351} 3352 3353/// \brief Reference initialization without resolving overloaded functions. 3354static void TryReferenceInitializationCore(Sema &S, 3355 const InitializedEntity &Entity, 3356 const InitializationKind &Kind, 3357 Expr *Initializer, 3358 QualType cv1T1, QualType T1, 3359 Qualifiers T1Quals, 3360 QualType cv2T2, QualType T2, 3361 Qualifiers T2Quals, 3362 InitializationSequence &Sequence) { 3363 QualType DestType = Entity.getType(); 3364 SourceLocation DeclLoc = Initializer->getLocStart(); 3365 // Compute some basic properties of the types and the initializer. 3366 bool isLValueRef = DestType->isLValueReferenceType(); 3367 bool isRValueRef = !isLValueRef; 3368 bool DerivedToBase = false; 3369 bool ObjCConversion = false; 3370 bool ObjCLifetimeConversion = false; 3371 Expr::Classification InitCategory = Initializer->Classify(S.Context); 3372 Sema::ReferenceCompareResult RefRelationship 3373 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, DerivedToBase, 3374 ObjCConversion, ObjCLifetimeConversion); 3375 3376 // C++0x [dcl.init.ref]p5: 3377 // A reference to type "cv1 T1" is initialized by an expression of type 3378 // "cv2 T2" as follows: 3379 // 3380 // - If the reference is an lvalue reference and the initializer 3381 // expression 3382 // Note the analogous bullet points for rvlaue refs to functions. Because 3383 // there are no function rvalues in C++, rvalue refs to functions are treated 3384 // like lvalue refs. 3385 OverloadingResult ConvOvlResult = OR_Success; 3386 bool T1Function = T1->isFunctionType(); 3387 if (isLValueRef || T1Function) { 3388 if (InitCategory.isLValue() && 3389 (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification || 3390 (Kind.isCStyleOrFunctionalCast() && 3391 RefRelationship == Sema::Ref_Related))) { 3392 // - is an lvalue (but is not a bit-field), and "cv1 T1" is 3393 // reference-compatible with "cv2 T2," or 3394 // 3395 // Per C++ [over.best.ics]p2, we don't diagnose whether the lvalue is a 3396 // bit-field when we're determining whether the reference initialization 3397 // can occur. However, we do pay attention to whether it is a bit-field 3398 // to decide whether we're actually binding to a temporary created from 3399 // the bit-field. 3400 if (DerivedToBase) 3401 Sequence.AddDerivedToBaseCastStep( 3402 S.Context.getQualifiedType(T1, T2Quals), 3403 VK_LValue); 3404 else if (ObjCConversion) 3405 Sequence.AddObjCObjectConversionStep( 3406 S.Context.getQualifiedType(T1, T2Quals)); 3407 3408 if (T1Quals != T2Quals) 3409 Sequence.AddQualificationConversionStep(cv1T1, VK_LValue); 3410 bool BindingTemporary = T1Quals.hasConst() && !T1Quals.hasVolatile() && 3411 (Initializer->getBitField() || Initializer->refersToVectorElement()); 3412 Sequence.AddReferenceBindingStep(cv1T1, BindingTemporary); 3413 return; 3414 } 3415 3416 // - has a class type (i.e., T2 is a class type), where T1 is not 3417 // reference-related to T2, and can be implicitly converted to an 3418 // lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible 3419 // with "cv3 T3" (this conversion is selected by enumerating the 3420 // applicable conversion functions (13.3.1.6) and choosing the best 3421 // one through overload resolution (13.3)), 3422 // If we have an rvalue ref to function type here, the rhs must be 3423 // an rvalue. 3424 if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType() && 3425 (isLValueRef || InitCategory.isRValue())) { 3426 ConvOvlResult = TryRefInitWithConversionFunction(S, Entity, Kind, 3427 Initializer, 3428 /*AllowRValues=*/isRValueRef, 3429 Sequence); 3430 if (ConvOvlResult == OR_Success) 3431 return; 3432 if (ConvOvlResult != OR_No_Viable_Function) { 3433 Sequence.SetOverloadFailure( 3434 InitializationSequence::FK_ReferenceInitOverloadFailed, 3435 ConvOvlResult); 3436 } 3437 } 3438 } 3439 3440 // - Otherwise, the reference shall be an lvalue reference to a 3441 // non-volatile const type (i.e., cv1 shall be const), or the reference 3442 // shall be an rvalue reference. 3443 if (isLValueRef && !(T1Quals.hasConst() && !T1Quals.hasVolatile())) { 3444 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) 3445 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 3446 else if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty()) 3447 Sequence.SetOverloadFailure( 3448 InitializationSequence::FK_ReferenceInitOverloadFailed, 3449 ConvOvlResult); 3450 else 3451 Sequence.SetFailed(InitCategory.isLValue() 3452 ? (RefRelationship == Sema::Ref_Related 3453 ? InitializationSequence::FK_ReferenceInitDropsQualifiers 3454 : InitializationSequence::FK_NonConstLValueReferenceBindingToUnrelated) 3455 : InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary); 3456 3457 return; 3458 } 3459 3460 // - If the initializer expression 3461 // - is an xvalue, class prvalue, array prvalue, or function lvalue and 3462 // "cv1 T1" is reference-compatible with "cv2 T2" 3463 // Note: functions are handled below. 3464 if (!T1Function && 3465 (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification || 3466 (Kind.isCStyleOrFunctionalCast() && 3467 RefRelationship == Sema::Ref_Related)) && 3468 (InitCategory.isXValue() || 3469 (InitCategory.isPRValue() && T2->isRecordType()) || 3470 (InitCategory.isPRValue() && T2->isArrayType()))) { 3471 ExprValueKind ValueKind = InitCategory.isXValue()? VK_XValue : VK_RValue; 3472 if (InitCategory.isPRValue() && T2->isRecordType()) { 3473 // The corresponding bullet in C++03 [dcl.init.ref]p5 gives the 3474 // compiler the freedom to perform a copy here or bind to the 3475 // object, while C++0x requires that we bind directly to the 3476 // object. Hence, we always bind to the object without making an 3477 // extra copy. However, in C++03 requires that we check for the 3478 // presence of a suitable copy constructor: 3479 // 3480 // The constructor that would be used to make the copy shall 3481 // be callable whether or not the copy is actually done. 3482 if (!S.getLangOptions().CPlusPlus0x && !S.getLangOptions().MicrosoftExt) 3483 Sequence.AddExtraneousCopyToTemporary(cv2T2); 3484 else if (S.getLangOptions().CPlusPlus0x) 3485 CheckCXX98CompatAccessibleCopy(S, Entity, Initializer); 3486 } 3487 3488 if (DerivedToBase) 3489 Sequence.AddDerivedToBaseCastStep(S.Context.getQualifiedType(T1, T2Quals), 3490 ValueKind); 3491 else if (ObjCConversion) 3492 Sequence.AddObjCObjectConversionStep( 3493 S.Context.getQualifiedType(T1, T2Quals)); 3494 3495 if (T1Quals != T2Quals) 3496 Sequence.AddQualificationConversionStep(cv1T1, ValueKind); 3497 Sequence.AddReferenceBindingStep(cv1T1, 3498 /*bindingTemporary=*/InitCategory.isPRValue()); 3499 return; 3500 } 3501 3502 // - has a class type (i.e., T2 is a class type), where T1 is not 3503 // reference-related to T2, and can be implicitly converted to an 3504 // xvalue, class prvalue, or function lvalue of type "cv3 T3", 3505 // where "cv1 T1" is reference-compatible with "cv3 T3", 3506 if (T2->isRecordType()) { 3507 if (RefRelationship == Sema::Ref_Incompatible) { 3508 ConvOvlResult = TryRefInitWithConversionFunction(S, Entity, 3509 Kind, Initializer, 3510 /*AllowRValues=*/true, 3511 Sequence); 3512 if (ConvOvlResult) 3513 Sequence.SetOverloadFailure( 3514 InitializationSequence::FK_ReferenceInitOverloadFailed, 3515 ConvOvlResult); 3516 3517 return; 3518 } 3519 3520 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers); 3521 return; 3522 } 3523 3524 // - Otherwise, a temporary of type "cv1 T1" is created and initialized 3525 // from the initializer expression using the rules for a non-reference 3526 // copy initialization (8.5). The reference is then bound to the 3527 // temporary. [...] 3528 3529 // Determine whether we are allowed to call explicit constructors or 3530 // explicit conversion operators. 3531 bool AllowExplicit = Kind.AllowExplicit(); 3532 3533 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(cv1T1); 3534 3535 ImplicitConversionSequence ICS 3536 = S.TryImplicitConversion(Initializer, TempEntity.getType(), 3537 /*SuppressUserConversions*/ false, 3538 AllowExplicit, 3539 /*FIXME:InOverloadResolution=*/false, 3540 /*CStyle=*/Kind.isCStyleOrFunctionalCast(), 3541 /*AllowObjCWritebackConversion=*/false); 3542 3543 if (ICS.isBad()) { 3544 // FIXME: Use the conversion function set stored in ICS to turn 3545 // this into an overloading ambiguity diagnostic. However, we need 3546 // to keep that set as an OverloadCandidateSet rather than as some 3547 // other kind of set. 3548 if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty()) 3549 Sequence.SetOverloadFailure( 3550 InitializationSequence::FK_ReferenceInitOverloadFailed, 3551 ConvOvlResult); 3552 else if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) 3553 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 3554 else 3555 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed); 3556 return; 3557 } else { 3558 Sequence.AddConversionSequenceStep(ICS, TempEntity.getType()); 3559 } 3560 3561 // [...] If T1 is reference-related to T2, cv1 must be the 3562 // same cv-qualification as, or greater cv-qualification 3563 // than, cv2; otherwise, the program is ill-formed. 3564 unsigned T1CVRQuals = T1Quals.getCVRQualifiers(); 3565 unsigned T2CVRQuals = T2Quals.getCVRQualifiers(); 3566 if (RefRelationship == Sema::Ref_Related && 3567 (T1CVRQuals | T2CVRQuals) != T1CVRQuals) { 3568 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers); 3569 return; 3570 } 3571 3572 // [...] If T1 is reference-related to T2 and the reference is an rvalue 3573 // reference, the initializer expression shall not be an lvalue. 3574 if (RefRelationship >= Sema::Ref_Related && !isLValueRef && 3575 InitCategory.isLValue()) { 3576 Sequence.SetFailed( 3577 InitializationSequence::FK_RValueReferenceBindingToLValue); 3578 return; 3579 } 3580 3581 Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true); 3582 return; 3583} 3584 3585/// \brief Attempt character array initialization from a string literal 3586/// (C++ [dcl.init.string], C99 6.7.8). 3587static void TryStringLiteralInitialization(Sema &S, 3588 const InitializedEntity &Entity, 3589 const InitializationKind &Kind, 3590 Expr *Initializer, 3591 InitializationSequence &Sequence) { 3592 Sequence.AddStringInitStep(Entity.getType()); 3593} 3594 3595/// \brief Attempt value initialization (C++ [dcl.init]p7). 3596static void TryValueInitialization(Sema &S, 3597 const InitializedEntity &Entity, 3598 const InitializationKind &Kind, 3599 InitializationSequence &Sequence) { 3600 // C++98 [dcl.init]p5, C++11 [dcl.init]p7: 3601 // 3602 // To value-initialize an object of type T means: 3603 QualType T = Entity.getType(); 3604 3605 // -- if T is an array type, then each element is value-initialized; 3606 T = S.Context.getBaseElementType(T); 3607 3608 if (const RecordType *RT = T->getAs<RecordType>()) { 3609 if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 3610 // C++98: 3611 // -- if T is a class type (clause 9) with a user-declared 3612 // constructor (12.1), then the default constructor for T is 3613 // called (and the initialization is ill-formed if T has no 3614 // accessible default constructor); 3615 if (!S.getLangOptions().CPlusPlus0x) { 3616 if (ClassDecl->hasUserDeclaredConstructor()) 3617 // FIXME: we really want to refer to a single subobject of the array, 3618 // but Entity doesn't have a way to capture that (yet). 3619 return TryConstructorInitialization(S, Entity, Kind, 0, 0, 3620 T, Sequence); 3621 } else { 3622 // C++11: 3623 // -- if T is a class type (clause 9) with either no default constructor 3624 // (12.1 [class.ctor]) or a default constructor that is user-provided 3625 // or deleted, then the object is default-initialized; 3626 CXXConstructorDecl *CD = S.LookupDefaultConstructor(ClassDecl); 3627 if (!CD || !CD->getCanonicalDecl()->isDefaulted() || CD->isDeleted()) 3628 return TryConstructorInitialization(S, Entity, Kind, 0, 0, 3629 T, Sequence); 3630 } 3631 3632 // -- if T is a (possibly cv-qualified) non-union class type without a 3633 // user-provided or deleted default constructor, then the object is 3634 // zero-initialized and, if T has a non-trivial default constructor, 3635 // default-initialized; 3636 if ((ClassDecl->getTagKind() == TTK_Class || 3637 ClassDecl->getTagKind() == TTK_Struct)) { 3638 Sequence.AddZeroInitializationStep(Entity.getType()); 3639 return TryConstructorInitialization(S, Entity, Kind, 0, 0, T, Sequence); 3640 } 3641 } 3642 } 3643 3644 Sequence.AddZeroInitializationStep(Entity.getType()); 3645} 3646 3647/// \brief Attempt default initialization (C++ [dcl.init]p6). 3648static void TryDefaultInitialization(Sema &S, 3649 const InitializedEntity &Entity, 3650 const InitializationKind &Kind, 3651 InitializationSequence &Sequence) { 3652 assert(Kind.getKind() == InitializationKind::IK_Default); 3653 3654 // C++ [dcl.init]p6: 3655 // To default-initialize an object of type T means: 3656 // - if T is an array type, each element is default-initialized; 3657 QualType DestType = S.Context.getBaseElementType(Entity.getType()); 3658 3659 // - if T is a (possibly cv-qualified) class type (Clause 9), the default 3660 // constructor for T is called (and the initialization is ill-formed if 3661 // T has no accessible default constructor); 3662 if (DestType->isRecordType() && S.getLangOptions().CPlusPlus) { 3663 TryConstructorInitialization(S, Entity, Kind, 0, 0, DestType, Sequence); 3664 return; 3665 } 3666 3667 // - otherwise, no initialization is performed. 3668 3669 // If a program calls for the default initialization of an object of 3670 // a const-qualified type T, T shall be a class type with a user-provided 3671 // default constructor. 3672 if (DestType.isConstQualified() && S.getLangOptions().CPlusPlus) { 3673 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst); 3674 return; 3675 } 3676 3677 // If the destination type has a lifetime property, zero-initialize it. 3678 if (DestType.getQualifiers().hasObjCLifetime()) { 3679 Sequence.AddZeroInitializationStep(Entity.getType()); 3680 return; 3681 } 3682} 3683 3684/// \brief Attempt a user-defined conversion between two types (C++ [dcl.init]), 3685/// which enumerates all conversion functions and performs overload resolution 3686/// to select the best. 3687static void TryUserDefinedConversion(Sema &S, 3688 const InitializedEntity &Entity, 3689 const InitializationKind &Kind, 3690 Expr *Initializer, 3691 InitializationSequence &Sequence) { 3692 QualType DestType = Entity.getType(); 3693 assert(!DestType->isReferenceType() && "References are handled elsewhere"); 3694 QualType SourceType = Initializer->getType(); 3695 assert((DestType->isRecordType() || SourceType->isRecordType()) && 3696 "Must have a class type to perform a user-defined conversion"); 3697 3698 // Build the candidate set directly in the initialization sequence 3699 // structure, so that it will persist if we fail. 3700 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 3701 CandidateSet.clear(); 3702 3703 // Determine whether we are allowed to call explicit constructors or 3704 // explicit conversion operators. 3705 bool AllowExplicit = Kind.AllowExplicit(); 3706 3707 if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) { 3708 // The type we're converting to is a class type. Enumerate its constructors 3709 // to see if there is a suitable conversion. 3710 CXXRecordDecl *DestRecordDecl 3711 = cast<CXXRecordDecl>(DestRecordType->getDecl()); 3712 3713 // Try to complete the type we're converting to. 3714 if (!S.RequireCompleteType(Kind.getLocation(), DestType, 0)) { 3715 DeclContext::lookup_iterator Con, ConEnd; 3716 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(DestRecordDecl); 3717 Con != ConEnd; ++Con) { 3718 NamedDecl *D = *Con; 3719 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 3720 3721 // Find the constructor (which may be a template). 3722 CXXConstructorDecl *Constructor = 0; 3723 FunctionTemplateDecl *ConstructorTmpl 3724 = dyn_cast<FunctionTemplateDecl>(D); 3725 if (ConstructorTmpl) 3726 Constructor = cast<CXXConstructorDecl>( 3727 ConstructorTmpl->getTemplatedDecl()); 3728 else 3729 Constructor = cast<CXXConstructorDecl>(D); 3730 3731 if (!Constructor->isInvalidDecl() && 3732 Constructor->isConvertingConstructor(AllowExplicit)) { 3733 if (ConstructorTmpl) 3734 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3735 /*ExplicitArgs*/ 0, 3736 Initializer, CandidateSet, 3737 /*SuppressUserConversions=*/true); 3738 else 3739 S.AddOverloadCandidate(Constructor, FoundDecl, 3740 Initializer, CandidateSet, 3741 /*SuppressUserConversions=*/true); 3742 } 3743 } 3744 } 3745 } 3746 3747 SourceLocation DeclLoc = Initializer->getLocStart(); 3748 3749 if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) { 3750 // The type we're converting from is a class type, enumerate its conversion 3751 // functions. 3752 3753 // We can only enumerate the conversion functions for a complete type; if 3754 // the type isn't complete, simply skip this step. 3755 if (!S.RequireCompleteType(DeclLoc, SourceType, 0)) { 3756 CXXRecordDecl *SourceRecordDecl 3757 = cast<CXXRecordDecl>(SourceRecordType->getDecl()); 3758 3759 const UnresolvedSetImpl *Conversions 3760 = SourceRecordDecl->getVisibleConversionFunctions(); 3761 for (UnresolvedSetImpl::const_iterator I = Conversions->begin(), 3762 E = Conversions->end(); 3763 I != E; ++I) { 3764 NamedDecl *D = *I; 3765 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3766 if (isa<UsingShadowDecl>(D)) 3767 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3768 3769 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D); 3770 CXXConversionDecl *Conv; 3771 if (ConvTemplate) 3772 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3773 else 3774 Conv = cast<CXXConversionDecl>(D); 3775 3776 if (AllowExplicit || !Conv->isExplicit()) { 3777 if (ConvTemplate) 3778 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), 3779 ActingDC, Initializer, DestType, 3780 CandidateSet); 3781 else 3782 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, 3783 Initializer, DestType, CandidateSet); 3784 } 3785 } 3786 } 3787 } 3788 3789 // Perform overload resolution. If it fails, return the failed result. 3790 OverloadCandidateSet::iterator Best; 3791 if (OverloadingResult Result 3792 = CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 3793 Sequence.SetOverloadFailure( 3794 InitializationSequence::FK_UserConversionOverloadFailed, 3795 Result); 3796 return; 3797 } 3798 3799 FunctionDecl *Function = Best->Function; 3800 S.MarkFunctionReferenced(DeclLoc, Function); 3801 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3802 3803 if (isa<CXXConstructorDecl>(Function)) { 3804 // Add the user-defined conversion step. Any cv-qualification conversion is 3805 // subsumed by the initialization. Per DR5, the created temporary is of the 3806 // cv-unqualified type of the destination. 3807 Sequence.AddUserConversionStep(Function, Best->FoundDecl, 3808 DestType.getUnqualifiedType(), 3809 HadMultipleCandidates); 3810 return; 3811 } 3812 3813 // Add the user-defined conversion step that calls the conversion function. 3814 QualType ConvType = Function->getCallResultType(); 3815 if (ConvType->getAs<RecordType>()) { 3816 // If we're converting to a class type, there may be an copy of 3817 // the resulting temporary object (possible to create an object of 3818 // a base class type). That copy is not a separate conversion, so 3819 // we just make a note of the actual destination type (possibly a 3820 // base class of the type returned by the conversion function) and 3821 // let the user-defined conversion step handle the conversion. 3822 Sequence.AddUserConversionStep(Function, Best->FoundDecl, DestType, 3823 HadMultipleCandidates); 3824 return; 3825 } 3826 3827 Sequence.AddUserConversionStep(Function, Best->FoundDecl, ConvType, 3828 HadMultipleCandidates); 3829 3830 // If the conversion following the call to the conversion function 3831 // is interesting, add it as a separate step. 3832 if (Best->FinalConversion.First || Best->FinalConversion.Second || 3833 Best->FinalConversion.Third) { 3834 ImplicitConversionSequence ICS; 3835 ICS.setStandard(); 3836 ICS.Standard = Best->FinalConversion; 3837 Sequence.AddConversionSequenceStep(ICS, DestType); 3838 } 3839} 3840 3841/// The non-zero enum values here are indexes into diagnostic alternatives. 3842enum InvalidICRKind { IIK_okay, IIK_nonlocal, IIK_nonscalar }; 3843 3844/// Determines whether this expression is an acceptable ICR source. 3845static InvalidICRKind isInvalidICRSource(ASTContext &C, Expr *e, 3846 bool isAddressOf) { 3847 // Skip parens. 3848 e = e->IgnoreParens(); 3849 3850 // Skip address-of nodes. 3851 if (UnaryOperator *op = dyn_cast<UnaryOperator>(e)) { 3852 if (op->getOpcode() == UO_AddrOf) 3853 return isInvalidICRSource(C, op->getSubExpr(), /*addressof*/ true); 3854 3855 // Skip certain casts. 3856 } else if (CastExpr *ce = dyn_cast<CastExpr>(e)) { 3857 switch (ce->getCastKind()) { 3858 case CK_Dependent: 3859 case CK_BitCast: 3860 case CK_LValueBitCast: 3861 case CK_NoOp: 3862 return isInvalidICRSource(C, ce->getSubExpr(), isAddressOf); 3863 3864 case CK_ArrayToPointerDecay: 3865 return IIK_nonscalar; 3866 3867 case CK_NullToPointer: 3868 return IIK_okay; 3869 3870 default: 3871 break; 3872 } 3873 3874 // If we have a declaration reference, it had better be a local variable. 3875 } else if (isa<DeclRefExpr>(e) || isa<BlockDeclRefExpr>(e)) { 3876 if (!isAddressOf) return IIK_nonlocal; 3877 3878 VarDecl *var; 3879 if (isa<DeclRefExpr>(e)) { 3880 var = dyn_cast<VarDecl>(cast<DeclRefExpr>(e)->getDecl()); 3881 if (!var) return IIK_nonlocal; 3882 } else { 3883 var = cast<BlockDeclRefExpr>(e)->getDecl(); 3884 } 3885 3886 return (var->hasLocalStorage() ? IIK_okay : IIK_nonlocal); 3887 3888 // If we have a conditional operator, check both sides. 3889 } else if (ConditionalOperator *cond = dyn_cast<ConditionalOperator>(e)) { 3890 if (InvalidICRKind iik = isInvalidICRSource(C, cond->getLHS(), isAddressOf)) 3891 return iik; 3892 3893 return isInvalidICRSource(C, cond->getRHS(), isAddressOf); 3894 3895 // These are never scalar. 3896 } else if (isa<ArraySubscriptExpr>(e)) { 3897 return IIK_nonscalar; 3898 3899 // Otherwise, it needs to be a null pointer constant. 3900 } else { 3901 return (e->isNullPointerConstant(C, Expr::NPC_ValueDependentIsNull) 3902 ? IIK_okay : IIK_nonlocal); 3903 } 3904 3905 return IIK_nonlocal; 3906} 3907 3908/// Check whether the given expression is a valid operand for an 3909/// indirect copy/restore. 3910static void checkIndirectCopyRestoreSource(Sema &S, Expr *src) { 3911 assert(src->isRValue()); 3912 3913 InvalidICRKind iik = isInvalidICRSource(S.Context, src, false); 3914 if (iik == IIK_okay) return; 3915 3916 S.Diag(src->getExprLoc(), diag::err_arc_nonlocal_writeback) 3917 << ((unsigned) iik - 1) // shift index into diagnostic explanations 3918 << src->getSourceRange(); 3919} 3920 3921/// \brief Determine whether we have compatible array types for the 3922/// purposes of GNU by-copy array initialization. 3923static bool hasCompatibleArrayTypes(ASTContext &Context, 3924 const ArrayType *Dest, 3925 const ArrayType *Source) { 3926 // If the source and destination array types are equivalent, we're 3927 // done. 3928 if (Context.hasSameType(QualType(Dest, 0), QualType(Source, 0))) 3929 return true; 3930 3931 // Make sure that the element types are the same. 3932 if (!Context.hasSameType(Dest->getElementType(), Source->getElementType())) 3933 return false; 3934 3935 // The only mismatch we allow is when the destination is an 3936 // incomplete array type and the source is a constant array type. 3937 return Source->isConstantArrayType() && Dest->isIncompleteArrayType(); 3938} 3939 3940static bool tryObjCWritebackConversion(Sema &S, 3941 InitializationSequence &Sequence, 3942 const InitializedEntity &Entity, 3943 Expr *Initializer) { 3944 bool ArrayDecay = false; 3945 QualType ArgType = Initializer->getType(); 3946 QualType ArgPointee; 3947 if (const ArrayType *ArgArrayType = S.Context.getAsArrayType(ArgType)) { 3948 ArrayDecay = true; 3949 ArgPointee = ArgArrayType->getElementType(); 3950 ArgType = S.Context.getPointerType(ArgPointee); 3951 } 3952 3953 // Handle write-back conversion. 3954 QualType ConvertedArgType; 3955 if (!S.isObjCWritebackConversion(ArgType, Entity.getType(), 3956 ConvertedArgType)) 3957 return false; 3958 3959 // We should copy unless we're passing to an argument explicitly 3960 // marked 'out'. 3961 bool ShouldCopy = true; 3962 if (ParmVarDecl *param = cast_or_null<ParmVarDecl>(Entity.getDecl())) 3963 ShouldCopy = (param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out); 3964 3965 // Do we need an lvalue conversion? 3966 if (ArrayDecay || Initializer->isGLValue()) { 3967 ImplicitConversionSequence ICS; 3968 ICS.setStandard(); 3969 ICS.Standard.setAsIdentityConversion(); 3970 3971 QualType ResultType; 3972 if (ArrayDecay) { 3973 ICS.Standard.First = ICK_Array_To_Pointer; 3974 ResultType = S.Context.getPointerType(ArgPointee); 3975 } else { 3976 ICS.Standard.First = ICK_Lvalue_To_Rvalue; 3977 ResultType = Initializer->getType().getNonLValueExprType(S.Context); 3978 } 3979 3980 Sequence.AddConversionSequenceStep(ICS, ResultType); 3981 } 3982 3983 Sequence.AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy); 3984 return true; 3985} 3986 3987InitializationSequence::InitializationSequence(Sema &S, 3988 const InitializedEntity &Entity, 3989 const InitializationKind &Kind, 3990 Expr **Args, 3991 unsigned NumArgs) 3992 : FailedCandidateSet(Kind.getLocation()) { 3993 ASTContext &Context = S.Context; 3994 3995 // C++0x [dcl.init]p16: 3996 // The semantics of initializers are as follows. The destination type is 3997 // the type of the object or reference being initialized and the source 3998 // type is the type of the initializer expression. The source type is not 3999 // defined when the initializer is a braced-init-list or when it is a 4000 // parenthesized list of expressions. 4001 QualType DestType = Entity.getType(); 4002 4003 if (DestType->isDependentType() || 4004 Expr::hasAnyTypeDependentArguments(llvm::makeArrayRef(Args, NumArgs))) { 4005 SequenceKind = DependentSequence; 4006 return; 4007 } 4008 4009 // Almost everything is a normal sequence. 4010 setSequenceKind(NormalSequence); 4011 4012 for (unsigned I = 0; I != NumArgs; ++I) 4013 if (Args[I]->getType()->isNonOverloadPlaceholderType()) { 4014 // FIXME: should we be doing this here? 4015 ExprResult result = S.CheckPlaceholderExpr(Args[I]); 4016 if (result.isInvalid()) { 4017 SetFailed(FK_PlaceholderType); 4018 return; 4019 } 4020 Args[I] = result.take(); 4021 } 4022 4023 4024 QualType SourceType; 4025 Expr *Initializer = 0; 4026 if (NumArgs == 1) { 4027 Initializer = Args[0]; 4028 if (!isa<InitListExpr>(Initializer)) 4029 SourceType = Initializer->getType(); 4030 } 4031 4032 // - If the initializer is a (non-parenthesized) braced-init-list, the 4033 // object is list-initialized (8.5.4). 4034 if (Kind.getKind() != InitializationKind::IK_Direct) { 4035 if (InitListExpr *InitList = dyn_cast_or_null<InitListExpr>(Initializer)) { 4036 TryListInitialization(S, Entity, Kind, InitList, *this); 4037 return; 4038 } 4039 } 4040 4041 // - If the destination type is a reference type, see 8.5.3. 4042 if (DestType->isReferenceType()) { 4043 // C++0x [dcl.init.ref]p1: 4044 // A variable declared to be a T& or T&&, that is, "reference to type T" 4045 // (8.3.2), shall be initialized by an object, or function, of type T or 4046 // by an object that can be converted into a T. 4047 // (Therefore, multiple arguments are not permitted.) 4048 if (NumArgs != 1) 4049 SetFailed(FK_TooManyInitsForReference); 4050 else 4051 TryReferenceInitialization(S, Entity, Kind, Args[0], *this); 4052 return; 4053 } 4054 4055 // - If the initializer is (), the object is value-initialized. 4056 if (Kind.getKind() == InitializationKind::IK_Value || 4057 (Kind.getKind() == InitializationKind::IK_Direct && NumArgs == 0)) { 4058 TryValueInitialization(S, Entity, Kind, *this); 4059 return; 4060 } 4061 4062 // Handle default initialization. 4063 if (Kind.getKind() == InitializationKind::IK_Default) { 4064 TryDefaultInitialization(S, Entity, Kind, *this); 4065 return; 4066 } 4067 4068 // - If the destination type is an array of characters, an array of 4069 // char16_t, an array of char32_t, or an array of wchar_t, and the 4070 // initializer is a string literal, see 8.5.2. 4071 // - Otherwise, if the destination type is an array, the program is 4072 // ill-formed. 4073 if (const ArrayType *DestAT = Context.getAsArrayType(DestType)) { 4074 if (Initializer && isa<VariableArrayType>(DestAT)) { 4075 SetFailed(FK_VariableLengthArrayHasInitializer); 4076 return; 4077 } 4078 4079 if (Initializer && IsStringInit(Initializer, DestAT, Context)) { 4080 TryStringLiteralInitialization(S, Entity, Kind, Initializer, *this); 4081 return; 4082 } 4083 4084 // Note: as an GNU C extension, we allow initialization of an 4085 // array from a compound literal that creates an array of the same 4086 // type, so long as the initializer has no side effects. 4087 if (!S.getLangOptions().CPlusPlus && Initializer && 4088 isa<CompoundLiteralExpr>(Initializer->IgnoreParens()) && 4089 Initializer->getType()->isArrayType()) { 4090 const ArrayType *SourceAT 4091 = Context.getAsArrayType(Initializer->getType()); 4092 if (!hasCompatibleArrayTypes(S.Context, DestAT, SourceAT)) 4093 SetFailed(FK_ArrayTypeMismatch); 4094 else if (Initializer->HasSideEffects(S.Context)) 4095 SetFailed(FK_NonConstantArrayInit); 4096 else { 4097 AddArrayInitStep(DestType); 4098 } 4099 } 4100 // Note: as a GNU C++ extension, we allow initialization of a 4101 // class member from a parenthesized initializer list. 4102 else if (S.getLangOptions().CPlusPlus && 4103 Entity.getKind() == InitializedEntity::EK_Member && 4104 Initializer && isa<InitListExpr>(Initializer)) { 4105 TryListInitialization(S, Entity, Kind, cast<InitListExpr>(Initializer), 4106 *this); 4107 AddParenthesizedArrayInitStep(DestType); 4108 } else if (DestAT->getElementType()->isAnyCharacterType()) 4109 SetFailed(FK_ArrayNeedsInitListOrStringLiteral); 4110 else 4111 SetFailed(FK_ArrayNeedsInitList); 4112 4113 return; 4114 } 4115 4116 // Determine whether we should consider writeback conversions for 4117 // Objective-C ARC. 4118 bool allowObjCWritebackConversion = S.getLangOptions().ObjCAutoRefCount && 4119 Entity.getKind() == InitializedEntity::EK_Parameter; 4120 4121 // We're at the end of the line for C: it's either a write-back conversion 4122 // or it's a C assignment. There's no need to check anything else. 4123 if (!S.getLangOptions().CPlusPlus) { 4124 // If allowed, check whether this is an Objective-C writeback conversion. 4125 if (allowObjCWritebackConversion && 4126 tryObjCWritebackConversion(S, *this, Entity, Initializer)) { 4127 return; 4128 } 4129 4130 // Handle initialization in C 4131 AddCAssignmentStep(DestType); 4132 MaybeProduceObjCObject(S, *this, Entity); 4133 return; 4134 } 4135 4136 assert(S.getLangOptions().CPlusPlus); 4137 4138 // - If the destination type is a (possibly cv-qualified) class type: 4139 if (DestType->isRecordType()) { 4140 // - If the initialization is direct-initialization, or if it is 4141 // copy-initialization where the cv-unqualified version of the 4142 // source type is the same class as, or a derived class of, the 4143 // class of the destination, constructors are considered. [...] 4144 if (Kind.getKind() == InitializationKind::IK_Direct || 4145 (Kind.getKind() == InitializationKind::IK_Copy && 4146 (Context.hasSameUnqualifiedType(SourceType, DestType) || 4147 S.IsDerivedFrom(SourceType, DestType)))) 4148 TryConstructorInitialization(S, Entity, Kind, Args, NumArgs, 4149 Entity.getType(), *this); 4150 // - Otherwise (i.e., for the remaining copy-initialization cases), 4151 // user-defined conversion sequences that can convert from the source 4152 // type to the destination type or (when a conversion function is 4153 // used) to a derived class thereof are enumerated as described in 4154 // 13.3.1.4, and the best one is chosen through overload resolution 4155 // (13.3). 4156 else 4157 TryUserDefinedConversion(S, Entity, Kind, Initializer, *this); 4158 return; 4159 } 4160 4161 if (NumArgs > 1) { 4162 SetFailed(FK_TooManyInitsForScalar); 4163 return; 4164 } 4165 assert(NumArgs == 1 && "Zero-argument case handled above"); 4166 4167 // - Otherwise, if the source type is a (possibly cv-qualified) class 4168 // type, conversion functions are considered. 4169 if (!SourceType.isNull() && SourceType->isRecordType()) { 4170 TryUserDefinedConversion(S, Entity, Kind, Initializer, *this); 4171 MaybeProduceObjCObject(S, *this, Entity); 4172 return; 4173 } 4174 4175 // - Otherwise, the initial value of the object being initialized is the 4176 // (possibly converted) value of the initializer expression. Standard 4177 // conversions (Clause 4) will be used, if necessary, to convert the 4178 // initializer expression to the cv-unqualified version of the 4179 // destination type; no user-defined conversions are considered. 4180 4181 ImplicitConversionSequence ICS 4182 = S.TryImplicitConversion(Initializer, Entity.getType(), 4183 /*SuppressUserConversions*/true, 4184 /*AllowExplicitConversions*/ false, 4185 /*InOverloadResolution*/ false, 4186 /*CStyle=*/Kind.isCStyleOrFunctionalCast(), 4187 allowObjCWritebackConversion); 4188 4189 if (ICS.isStandard() && 4190 ICS.Standard.Second == ICK_Writeback_Conversion) { 4191 // Objective-C ARC writeback conversion. 4192 4193 // We should copy unless we're passing to an argument explicitly 4194 // marked 'out'. 4195 bool ShouldCopy = true; 4196 if (ParmVarDecl *Param = cast_or_null<ParmVarDecl>(Entity.getDecl())) 4197 ShouldCopy = (Param->getObjCDeclQualifier() != ParmVarDecl::OBJC_TQ_Out); 4198 4199 // If there was an lvalue adjustment, add it as a separate conversion. 4200 if (ICS.Standard.First == ICK_Array_To_Pointer || 4201 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 4202 ImplicitConversionSequence LvalueICS; 4203 LvalueICS.setStandard(); 4204 LvalueICS.Standard.setAsIdentityConversion(); 4205 LvalueICS.Standard.setAllToTypes(ICS.Standard.getToType(0)); 4206 LvalueICS.Standard.First = ICS.Standard.First; 4207 AddConversionSequenceStep(LvalueICS, ICS.Standard.getToType(0)); 4208 } 4209 4210 AddPassByIndirectCopyRestoreStep(Entity.getType(), ShouldCopy); 4211 } else if (ICS.isBad()) { 4212 DeclAccessPair dap; 4213 if (Initializer->getType() == Context.OverloadTy && 4214 !S.ResolveAddressOfOverloadedFunction(Initializer 4215 , DestType, false, dap)) 4216 SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 4217 else 4218 SetFailed(InitializationSequence::FK_ConversionFailed); 4219 } else { 4220 AddConversionSequenceStep(ICS, Entity.getType()); 4221 4222 MaybeProduceObjCObject(S, *this, Entity); 4223 } 4224} 4225 4226InitializationSequence::~InitializationSequence() { 4227 for (SmallVectorImpl<Step>::iterator Step = Steps.begin(), 4228 StepEnd = Steps.end(); 4229 Step != StepEnd; ++Step) 4230 Step->Destroy(); 4231} 4232 4233//===----------------------------------------------------------------------===// 4234// Perform initialization 4235//===----------------------------------------------------------------------===// 4236static Sema::AssignmentAction 4237getAssignmentAction(const InitializedEntity &Entity) { 4238 switch(Entity.getKind()) { 4239 case InitializedEntity::EK_Variable: 4240 case InitializedEntity::EK_New: 4241 case InitializedEntity::EK_Exception: 4242 case InitializedEntity::EK_Base: 4243 case InitializedEntity::EK_Delegating: 4244 return Sema::AA_Initializing; 4245 4246 case InitializedEntity::EK_Parameter: 4247 if (Entity.getDecl() && 4248 isa<ObjCMethodDecl>(Entity.getDecl()->getDeclContext())) 4249 return Sema::AA_Sending; 4250 4251 return Sema::AA_Passing; 4252 4253 case InitializedEntity::EK_Result: 4254 return Sema::AA_Returning; 4255 4256 case InitializedEntity::EK_Temporary: 4257 // FIXME: Can we tell apart casting vs. converting? 4258 return Sema::AA_Casting; 4259 4260 case InitializedEntity::EK_Member: 4261 case InitializedEntity::EK_ArrayElement: 4262 case InitializedEntity::EK_VectorElement: 4263 case InitializedEntity::EK_ComplexElement: 4264 case InitializedEntity::EK_BlockElement: 4265 case InitializedEntity::EK_LambdaCapture: 4266 return Sema::AA_Initializing; 4267 } 4268 4269 llvm_unreachable("Invalid EntityKind!"); 4270} 4271 4272/// \brief Whether we should binding a created object as a temporary when 4273/// initializing the given entity. 4274static bool shouldBindAsTemporary(const InitializedEntity &Entity) { 4275 switch (Entity.getKind()) { 4276 case InitializedEntity::EK_ArrayElement: 4277 case InitializedEntity::EK_Member: 4278 case InitializedEntity::EK_Result: 4279 case InitializedEntity::EK_New: 4280 case InitializedEntity::EK_Variable: 4281 case InitializedEntity::EK_Base: 4282 case InitializedEntity::EK_Delegating: 4283 case InitializedEntity::EK_VectorElement: 4284 case InitializedEntity::EK_ComplexElement: 4285 case InitializedEntity::EK_Exception: 4286 case InitializedEntity::EK_BlockElement: 4287 case InitializedEntity::EK_LambdaCapture: 4288 return false; 4289 4290 case InitializedEntity::EK_Parameter: 4291 case InitializedEntity::EK_Temporary: 4292 return true; 4293 } 4294 4295 llvm_unreachable("missed an InitializedEntity kind?"); 4296} 4297 4298/// \brief Whether the given entity, when initialized with an object 4299/// created for that initialization, requires destruction. 4300static bool shouldDestroyTemporary(const InitializedEntity &Entity) { 4301 switch (Entity.getKind()) { 4302 case InitializedEntity::EK_Member: 4303 case InitializedEntity::EK_Result: 4304 case InitializedEntity::EK_New: 4305 case InitializedEntity::EK_Base: 4306 case InitializedEntity::EK_Delegating: 4307 case InitializedEntity::EK_VectorElement: 4308 case InitializedEntity::EK_ComplexElement: 4309 case InitializedEntity::EK_BlockElement: 4310 case InitializedEntity::EK_LambdaCapture: 4311 return false; 4312 4313 case InitializedEntity::EK_Variable: 4314 case InitializedEntity::EK_Parameter: 4315 case InitializedEntity::EK_Temporary: 4316 case InitializedEntity::EK_ArrayElement: 4317 case InitializedEntity::EK_Exception: 4318 return true; 4319 } 4320 4321 llvm_unreachable("missed an InitializedEntity kind?"); 4322} 4323 4324/// \brief Look for copy and move constructors and constructor templates, for 4325/// copying an object via direct-initialization (per C++11 [dcl.init]p16). 4326static void LookupCopyAndMoveConstructors(Sema &S, 4327 OverloadCandidateSet &CandidateSet, 4328 CXXRecordDecl *Class, 4329 Expr *CurInitExpr) { 4330 DeclContext::lookup_iterator Con, ConEnd; 4331 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(Class); 4332 Con != ConEnd; ++Con) { 4333 CXXConstructorDecl *Constructor = 0; 4334 4335 if ((Constructor = dyn_cast<CXXConstructorDecl>(*Con))) { 4336 // Handle copy/moveconstructors, only. 4337 if (!Constructor || Constructor->isInvalidDecl() || 4338 !Constructor->isCopyOrMoveConstructor() || 4339 !Constructor->isConvertingConstructor(/*AllowExplicit=*/true)) 4340 continue; 4341 4342 DeclAccessPair FoundDecl 4343 = DeclAccessPair::make(Constructor, Constructor->getAccess()); 4344 S.AddOverloadCandidate(Constructor, FoundDecl, 4345 CurInitExpr, CandidateSet); 4346 continue; 4347 } 4348 4349 // Handle constructor templates. 4350 FunctionTemplateDecl *ConstructorTmpl = cast<FunctionTemplateDecl>(*Con); 4351 if (ConstructorTmpl->isInvalidDecl()) 4352 continue; 4353 4354 Constructor = cast<CXXConstructorDecl>( 4355 ConstructorTmpl->getTemplatedDecl()); 4356 if (!Constructor->isConvertingConstructor(/*AllowExplicit=*/true)) 4357 continue; 4358 4359 // FIXME: Do we need to limit this to copy-constructor-like 4360 // candidates? 4361 DeclAccessPair FoundDecl 4362 = DeclAccessPair::make(ConstructorTmpl, ConstructorTmpl->getAccess()); 4363 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 0, 4364 CurInitExpr, CandidateSet, true); 4365 } 4366} 4367 4368/// \brief Get the location at which initialization diagnostics should appear. 4369static SourceLocation getInitializationLoc(const InitializedEntity &Entity, 4370 Expr *Initializer) { 4371 switch (Entity.getKind()) { 4372 case InitializedEntity::EK_Result: 4373 return Entity.getReturnLoc(); 4374 4375 case InitializedEntity::EK_Exception: 4376 return Entity.getThrowLoc(); 4377 4378 case InitializedEntity::EK_Variable: 4379 return Entity.getDecl()->getLocation(); 4380 4381 case InitializedEntity::EK_LambdaCapture: 4382 return Entity.getCaptureLoc(); 4383 4384 case InitializedEntity::EK_ArrayElement: 4385 case InitializedEntity::EK_Member: 4386 case InitializedEntity::EK_Parameter: 4387 case InitializedEntity::EK_Temporary: 4388 case InitializedEntity::EK_New: 4389 case InitializedEntity::EK_Base: 4390 case InitializedEntity::EK_Delegating: 4391 case InitializedEntity::EK_VectorElement: 4392 case InitializedEntity::EK_ComplexElement: 4393 case InitializedEntity::EK_BlockElement: 4394 return Initializer->getLocStart(); 4395 } 4396 llvm_unreachable("missed an InitializedEntity kind?"); 4397} 4398 4399/// \brief Make a (potentially elidable) temporary copy of the object 4400/// provided by the given initializer by calling the appropriate copy 4401/// constructor. 4402/// 4403/// \param S The Sema object used for type-checking. 4404/// 4405/// \param T The type of the temporary object, which must either be 4406/// the type of the initializer expression or a superclass thereof. 4407/// 4408/// \param Enter The entity being initialized. 4409/// 4410/// \param CurInit The initializer expression. 4411/// 4412/// \param IsExtraneousCopy Whether this is an "extraneous" copy that 4413/// is permitted in C++03 (but not C++0x) when binding a reference to 4414/// an rvalue. 4415/// 4416/// \returns An expression that copies the initializer expression into 4417/// a temporary object, or an error expression if a copy could not be 4418/// created. 4419static ExprResult CopyObject(Sema &S, 4420 QualType T, 4421 const InitializedEntity &Entity, 4422 ExprResult CurInit, 4423 bool IsExtraneousCopy) { 4424 // Determine which class type we're copying to. 4425 Expr *CurInitExpr = (Expr *)CurInit.get(); 4426 CXXRecordDecl *Class = 0; 4427 if (const RecordType *Record = T->getAs<RecordType>()) 4428 Class = cast<CXXRecordDecl>(Record->getDecl()); 4429 if (!Class) 4430 return move(CurInit); 4431 4432 // C++0x [class.copy]p32: 4433 // When certain criteria are met, an implementation is allowed to 4434 // omit the copy/move construction of a class object, even if the 4435 // copy/move constructor and/or destructor for the object have 4436 // side effects. [...] 4437 // - when a temporary class object that has not been bound to a 4438 // reference (12.2) would be copied/moved to a class object 4439 // with the same cv-unqualified type, the copy/move operation 4440 // can be omitted by constructing the temporary object 4441 // directly into the target of the omitted copy/move 4442 // 4443 // Note that the other three bullets are handled elsewhere. Copy 4444 // elision for return statements and throw expressions are handled as part 4445 // of constructor initialization, while copy elision for exception handlers 4446 // is handled by the run-time. 4447 bool Elidable = CurInitExpr->isTemporaryObject(S.Context, Class); 4448 SourceLocation Loc = getInitializationLoc(Entity, CurInit.get()); 4449 4450 // Make sure that the type we are copying is complete. 4451 if (S.RequireCompleteType(Loc, T, S.PDiag(diag::err_temp_copy_incomplete))) 4452 return move(CurInit); 4453 4454 // Perform overload resolution using the class's copy/move constructors. 4455 // Only consider constructors and constructor templates. Per 4456 // C++0x [dcl.init]p16, second bullet to class types, this initialization 4457 // is direct-initialization. 4458 OverloadCandidateSet CandidateSet(Loc); 4459 LookupCopyAndMoveConstructors(S, CandidateSet, Class, CurInitExpr); 4460 4461 bool HadMultipleCandidates = (CandidateSet.size() > 1); 4462 4463 OverloadCandidateSet::iterator Best; 4464 switch (CandidateSet.BestViableFunction(S, Loc, Best)) { 4465 case OR_Success: 4466 break; 4467 4468 case OR_No_Viable_Function: 4469 S.Diag(Loc, IsExtraneousCopy && !S.isSFINAEContext() 4470 ? diag::ext_rvalue_to_reference_temp_copy_no_viable 4471 : diag::err_temp_copy_no_viable) 4472 << (int)Entity.getKind() << CurInitExpr->getType() 4473 << CurInitExpr->getSourceRange(); 4474 CandidateSet.NoteCandidates(S, OCD_AllCandidates, CurInitExpr); 4475 if (!IsExtraneousCopy || S.isSFINAEContext()) 4476 return ExprError(); 4477 return move(CurInit); 4478 4479 case OR_Ambiguous: 4480 S.Diag(Loc, diag::err_temp_copy_ambiguous) 4481 << (int)Entity.getKind() << CurInitExpr->getType() 4482 << CurInitExpr->getSourceRange(); 4483 CandidateSet.NoteCandidates(S, OCD_ViableCandidates, CurInitExpr); 4484 return ExprError(); 4485 4486 case OR_Deleted: 4487 S.Diag(Loc, diag::err_temp_copy_deleted) 4488 << (int)Entity.getKind() << CurInitExpr->getType() 4489 << CurInitExpr->getSourceRange(); 4490 S.Diag(Best->Function->getLocation(), diag::note_unavailable_here) 4491 << 1 << Best->Function->isDeleted(); 4492 return ExprError(); 4493 } 4494 4495 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function); 4496 ASTOwningVector<Expr*> ConstructorArgs(S); 4497 CurInit.release(); // Ownership transferred into MultiExprArg, below. 4498 4499 S.CheckConstructorAccess(Loc, Constructor, Entity, 4500 Best->FoundDecl.getAccess(), IsExtraneousCopy); 4501 4502 if (IsExtraneousCopy) { 4503 // If this is a totally extraneous copy for C++03 reference 4504 // binding purposes, just return the original initialization 4505 // expression. We don't generate an (elided) copy operation here 4506 // because doing so would require us to pass down a flag to avoid 4507 // infinite recursion, where each step adds another extraneous, 4508 // elidable copy. 4509 4510 // Instantiate the default arguments of any extra parameters in 4511 // the selected copy constructor, as if we were going to create a 4512 // proper call to the copy constructor. 4513 for (unsigned I = 1, N = Constructor->getNumParams(); I != N; ++I) { 4514 ParmVarDecl *Parm = Constructor->getParamDecl(I); 4515 if (S.RequireCompleteType(Loc, Parm->getType(), 4516 S.PDiag(diag::err_call_incomplete_argument))) 4517 break; 4518 4519 // Build the default argument expression; we don't actually care 4520 // if this succeeds or not, because this routine will complain 4521 // if there was a problem. 4522 S.BuildCXXDefaultArgExpr(Loc, Constructor, Parm); 4523 } 4524 4525 return S.Owned(CurInitExpr); 4526 } 4527 4528 S.MarkFunctionReferenced(Loc, Constructor); 4529 4530 // Determine the arguments required to actually perform the 4531 // constructor call (we might have derived-to-base conversions, or 4532 // the copy constructor may have default arguments). 4533 if (S.CompleteConstructorCall(Constructor, MultiExprArg(&CurInitExpr, 1), 4534 Loc, ConstructorArgs)) 4535 return ExprError(); 4536 4537 // Actually perform the constructor call. 4538 CurInit = S.BuildCXXConstructExpr(Loc, T, Constructor, Elidable, 4539 move_arg(ConstructorArgs), 4540 HadMultipleCandidates, 4541 /*ZeroInit*/ false, 4542 CXXConstructExpr::CK_Complete, 4543 SourceRange()); 4544 4545 // If we're supposed to bind temporaries, do so. 4546 if (!CurInit.isInvalid() && shouldBindAsTemporary(Entity)) 4547 CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>()); 4548 return move(CurInit); 4549} 4550 4551/// \brief Check whether elidable copy construction for binding a reference to 4552/// a temporary would have succeeded if we were building in C++98 mode, for 4553/// -Wc++98-compat. 4554static void CheckCXX98CompatAccessibleCopy(Sema &S, 4555 const InitializedEntity &Entity, 4556 Expr *CurInitExpr) { 4557 assert(S.getLangOptions().CPlusPlus0x); 4558 4559 const RecordType *Record = CurInitExpr->getType()->getAs<RecordType>(); 4560 if (!Record) 4561 return; 4562 4563 SourceLocation Loc = getInitializationLoc(Entity, CurInitExpr); 4564 if (S.Diags.getDiagnosticLevel(diag::warn_cxx98_compat_temp_copy, Loc) 4565 == DiagnosticsEngine::Ignored) 4566 return; 4567 4568 // Find constructors which would have been considered. 4569 OverloadCandidateSet CandidateSet(Loc); 4570 LookupCopyAndMoveConstructors( 4571 S, CandidateSet, cast<CXXRecordDecl>(Record->getDecl()), CurInitExpr); 4572 4573 // Perform overload resolution. 4574 OverloadCandidateSet::iterator Best; 4575 OverloadingResult OR = CandidateSet.BestViableFunction(S, Loc, Best); 4576 4577 PartialDiagnostic Diag = S.PDiag(diag::warn_cxx98_compat_temp_copy) 4578 << OR << (int)Entity.getKind() << CurInitExpr->getType() 4579 << CurInitExpr->getSourceRange(); 4580 4581 switch (OR) { 4582 case OR_Success: 4583 S.CheckConstructorAccess(Loc, cast<CXXConstructorDecl>(Best->Function), 4584 Best->FoundDecl.getAccess(), Diag); 4585 // FIXME: Check default arguments as far as that's possible. 4586 break; 4587 4588 case OR_No_Viable_Function: 4589 S.Diag(Loc, Diag); 4590 CandidateSet.NoteCandidates(S, OCD_AllCandidates, CurInitExpr); 4591 break; 4592 4593 case OR_Ambiguous: 4594 S.Diag(Loc, Diag); 4595 CandidateSet.NoteCandidates(S, OCD_ViableCandidates, CurInitExpr); 4596 break; 4597 4598 case OR_Deleted: 4599 S.Diag(Loc, Diag); 4600 S.Diag(Best->Function->getLocation(), diag::note_unavailable_here) 4601 << 1 << Best->Function->isDeleted(); 4602 break; 4603 } 4604} 4605 4606void InitializationSequence::PrintInitLocationNote(Sema &S, 4607 const InitializedEntity &Entity) { 4608 if (Entity.getKind() == InitializedEntity::EK_Parameter && Entity.getDecl()) { 4609 if (Entity.getDecl()->getLocation().isInvalid()) 4610 return; 4611 4612 if (Entity.getDecl()->getDeclName()) 4613 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_named_here) 4614 << Entity.getDecl()->getDeclName(); 4615 else 4616 S.Diag(Entity.getDecl()->getLocation(), diag::note_parameter_here); 4617 } 4618} 4619 4620static bool isReferenceBinding(const InitializationSequence::Step &s) { 4621 return s.Kind == InitializationSequence::SK_BindReference || 4622 s.Kind == InitializationSequence::SK_BindReferenceToTemporary; 4623} 4624 4625static ExprResult 4626PerformConstructorInitialization(Sema &S, 4627 const InitializedEntity &Entity, 4628 const InitializationKind &Kind, 4629 MultiExprArg Args, 4630 const InitializationSequence::Step& Step, 4631 bool &ConstructorInitRequiresZeroInit) { 4632 unsigned NumArgs = Args.size(); 4633 CXXConstructorDecl *Constructor 4634 = cast<CXXConstructorDecl>(Step.Function.Function); 4635 bool HadMultipleCandidates = Step.Function.HadMultipleCandidates; 4636 4637 // Build a call to the selected constructor. 4638 ASTOwningVector<Expr*> ConstructorArgs(S); 4639 SourceLocation Loc = (Kind.isCopyInit() && Kind.getEqualLoc().isValid()) 4640 ? Kind.getEqualLoc() 4641 : Kind.getLocation(); 4642 4643 if (Kind.getKind() == InitializationKind::IK_Default) { 4644 // Force even a trivial, implicit default constructor to be 4645 // semantically checked. We do this explicitly because we don't build 4646 // the definition for completely trivial constructors. 4647 assert(Constructor->getParent() && "No parent class for constructor."); 4648 if (Constructor->isDefaulted() && Constructor->isDefaultConstructor() && 4649 Constructor->isTrivial() && !Constructor->isUsed(false)) 4650 S.DefineImplicitDefaultConstructor(Loc, Constructor); 4651 } 4652 4653 ExprResult CurInit = S.Owned((Expr *)0); 4654 4655 // C++ [over.match.copy]p1: 4656 // - When initializing a temporary to be bound to the first parameter 4657 // of a constructor that takes a reference to possibly cv-qualified 4658 // T as its first argument, called with a single argument in the 4659 // context of direct-initialization, explicit conversion functions 4660 // are also considered. 4661 bool AllowExplicitConv = Kind.AllowExplicit() && !Kind.isCopyInit() && 4662 Args.size() == 1 && 4663 Constructor->isCopyOrMoveConstructor(); 4664 4665 // Determine the arguments required to actually perform the constructor 4666 // call. 4667 if (S.CompleteConstructorCall(Constructor, move(Args), 4668 Loc, ConstructorArgs, 4669 AllowExplicitConv)) 4670 return ExprError(); 4671 4672 4673 if (Entity.getKind() == InitializedEntity::EK_Temporary && 4674 NumArgs != 1 && // FIXME: Hack to work around cast weirdness 4675 (Kind.getKind() == InitializationKind::IK_Direct || 4676 Kind.getKind() == InitializationKind::IK_Value)) { 4677 // An explicitly-constructed temporary, e.g., X(1, 2). 4678 unsigned NumExprs = ConstructorArgs.size(); 4679 Expr **Exprs = (Expr **)ConstructorArgs.take(); 4680 S.MarkFunctionReferenced(Loc, Constructor); 4681 S.DiagnoseUseOfDecl(Constructor, Loc); 4682 4683 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo(); 4684 if (!TSInfo) 4685 TSInfo = S.Context.getTrivialTypeSourceInfo(Entity.getType(), Loc); 4686 4687 CurInit = S.Owned(new (S.Context) CXXTemporaryObjectExpr(S.Context, 4688 Constructor, 4689 TSInfo, 4690 Exprs, 4691 NumExprs, 4692 Kind.getParenRange(), 4693 HadMultipleCandidates, 4694 ConstructorInitRequiresZeroInit)); 4695 } else { 4696 CXXConstructExpr::ConstructionKind ConstructKind = 4697 CXXConstructExpr::CK_Complete; 4698 4699 if (Entity.getKind() == InitializedEntity::EK_Base) { 4700 ConstructKind = Entity.getBaseSpecifier()->isVirtual() ? 4701 CXXConstructExpr::CK_VirtualBase : 4702 CXXConstructExpr::CK_NonVirtualBase; 4703 } else if (Entity.getKind() == InitializedEntity::EK_Delegating) { 4704 ConstructKind = CXXConstructExpr::CK_Delegating; 4705 } 4706 4707 // Only get the parenthesis range if it is a direct construction. 4708 SourceRange parenRange = 4709 Kind.getKind() == InitializationKind::IK_Direct ? 4710 Kind.getParenRange() : SourceRange(); 4711 4712 // If the entity allows NRVO, mark the construction as elidable 4713 // unconditionally. 4714 if (Entity.allowsNRVO()) 4715 CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(), 4716 Constructor, /*Elidable=*/true, 4717 move_arg(ConstructorArgs), 4718 HadMultipleCandidates, 4719 ConstructorInitRequiresZeroInit, 4720 ConstructKind, 4721 parenRange); 4722 else 4723 CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(), 4724 Constructor, 4725 move_arg(ConstructorArgs), 4726 HadMultipleCandidates, 4727 ConstructorInitRequiresZeroInit, 4728 ConstructKind, 4729 parenRange); 4730 } 4731 if (CurInit.isInvalid()) 4732 return ExprError(); 4733 4734 // Only check access if all of that succeeded. 4735 S.CheckConstructorAccess(Loc, Constructor, Entity, 4736 Step.Function.FoundDecl.getAccess()); 4737 S.DiagnoseUseOfDecl(Step.Function.FoundDecl, Loc); 4738 4739 if (shouldBindAsTemporary(Entity)) 4740 CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>()); 4741 4742 return move(CurInit); 4743} 4744 4745ExprResult 4746InitializationSequence::Perform(Sema &S, 4747 const InitializedEntity &Entity, 4748 const InitializationKind &Kind, 4749 MultiExprArg Args, 4750 QualType *ResultType) { 4751 if (Failed()) { 4752 unsigned NumArgs = Args.size(); 4753 Diagnose(S, Entity, Kind, (Expr **)Args.release(), NumArgs); 4754 return ExprError(); 4755 } 4756 4757 if (getKind() == DependentSequence) { 4758 // If the declaration is a non-dependent, incomplete array type 4759 // that has an initializer, then its type will be completed once 4760 // the initializer is instantiated. 4761 if (ResultType && !Entity.getType()->isDependentType() && 4762 Args.size() == 1) { 4763 QualType DeclType = Entity.getType(); 4764 if (const IncompleteArrayType *ArrayT 4765 = S.Context.getAsIncompleteArrayType(DeclType)) { 4766 // FIXME: We don't currently have the ability to accurately 4767 // compute the length of an initializer list without 4768 // performing full type-checking of the initializer list 4769 // (since we have to determine where braces are implicitly 4770 // introduced and such). So, we fall back to making the array 4771 // type a dependently-sized array type with no specified 4772 // bound. 4773 if (isa<InitListExpr>((Expr *)Args.get()[0])) { 4774 SourceRange Brackets; 4775 4776 // Scavange the location of the brackets from the entity, if we can. 4777 if (DeclaratorDecl *DD = Entity.getDecl()) { 4778 if (TypeSourceInfo *TInfo = DD->getTypeSourceInfo()) { 4779 TypeLoc TL = TInfo->getTypeLoc(); 4780 if (IncompleteArrayTypeLoc *ArrayLoc 4781 = dyn_cast<IncompleteArrayTypeLoc>(&TL)) 4782 Brackets = ArrayLoc->getBracketsRange(); 4783 } 4784 } 4785 4786 *ResultType 4787 = S.Context.getDependentSizedArrayType(ArrayT->getElementType(), 4788 /*NumElts=*/0, 4789 ArrayT->getSizeModifier(), 4790 ArrayT->getIndexTypeCVRQualifiers(), 4791 Brackets); 4792 } 4793 4794 } 4795 } 4796 if (Kind.getKind() == InitializationKind::IK_Direct && 4797 !Kind.isExplicitCast()) { 4798 // Rebuild the ParenListExpr. 4799 SourceRange ParenRange = Kind.getParenRange(); 4800 return S.ActOnParenListExpr(ParenRange.getBegin(), ParenRange.getEnd(), 4801 move(Args)); 4802 } 4803 assert(Kind.getKind() == InitializationKind::IK_Copy || 4804 Kind.isExplicitCast()); 4805 return ExprResult(Args.release()[0]); 4806 } 4807 4808 // No steps means no initialization. 4809 if (Steps.empty()) 4810 return S.Owned((Expr *)0); 4811 4812 QualType DestType = Entity.getType().getNonReferenceType(); 4813 // FIXME: Ugly hack around the fact that Entity.getType() is not 4814 // the same as Entity.getDecl()->getType() in cases involving type merging, 4815 // and we want latter when it makes sense. 4816 if (ResultType) 4817 *ResultType = Entity.getDecl() ? Entity.getDecl()->getType() : 4818 Entity.getType(); 4819 4820 ExprResult CurInit = S.Owned((Expr *)0); 4821 4822 // For initialization steps that start with a single initializer, 4823 // grab the only argument out the Args and place it into the "current" 4824 // initializer. 4825 switch (Steps.front().Kind) { 4826 case SK_ResolveAddressOfOverloadedFunction: 4827 case SK_CastDerivedToBaseRValue: 4828 case SK_CastDerivedToBaseXValue: 4829 case SK_CastDerivedToBaseLValue: 4830 case SK_BindReference: 4831 case SK_BindReferenceToTemporary: 4832 case SK_ExtraneousCopyToTemporary: 4833 case SK_UserConversion: 4834 case SK_QualificationConversionLValue: 4835 case SK_QualificationConversionXValue: 4836 case SK_QualificationConversionRValue: 4837 case SK_ConversionSequence: 4838 case SK_ListConstructorCall: 4839 case SK_ListInitialization: 4840 case SK_UnwrapInitList: 4841 case SK_RewrapInitList: 4842 case SK_CAssignment: 4843 case SK_StringInit: 4844 case SK_ObjCObjectConversion: 4845 case SK_ArrayInit: 4846 case SK_ParenthesizedArrayInit: 4847 case SK_PassByIndirectCopyRestore: 4848 case SK_PassByIndirectRestore: 4849 case SK_ProduceObjCObject: 4850 case SK_StdInitializerList: { 4851 assert(Args.size() == 1); 4852 CurInit = Args.get()[0]; 4853 if (!CurInit.get()) return ExprError(); 4854 break; 4855 } 4856 4857 case SK_ConstructorInitialization: 4858 case SK_ZeroInitialization: 4859 break; 4860 } 4861 4862 // Walk through the computed steps for the initialization sequence, 4863 // performing the specified conversions along the way. 4864 bool ConstructorInitRequiresZeroInit = false; 4865 for (step_iterator Step = step_begin(), StepEnd = step_end(); 4866 Step != StepEnd; ++Step) { 4867 if (CurInit.isInvalid()) 4868 return ExprError(); 4869 4870 QualType SourceType = CurInit.get() ? CurInit.get()->getType() : QualType(); 4871 4872 switch (Step->Kind) { 4873 case SK_ResolveAddressOfOverloadedFunction: 4874 // Overload resolution determined which function invoke; update the 4875 // initializer to reflect that choice. 4876 S.CheckAddressOfMemberAccess(CurInit.get(), Step->Function.FoundDecl); 4877 S.DiagnoseUseOfDecl(Step->Function.FoundDecl, Kind.getLocation()); 4878 CurInit = S.FixOverloadedFunctionReference(move(CurInit), 4879 Step->Function.FoundDecl, 4880 Step->Function.Function); 4881 break; 4882 4883 case SK_CastDerivedToBaseRValue: 4884 case SK_CastDerivedToBaseXValue: 4885 case SK_CastDerivedToBaseLValue: { 4886 // We have a derived-to-base cast that produces either an rvalue or an 4887 // lvalue. Perform that cast. 4888 4889 CXXCastPath BasePath; 4890 4891 // Casts to inaccessible base classes are allowed with C-style casts. 4892 bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast(); 4893 if (S.CheckDerivedToBaseConversion(SourceType, Step->Type, 4894 CurInit.get()->getLocStart(), 4895 CurInit.get()->getSourceRange(), 4896 &BasePath, IgnoreBaseAccess)) 4897 return ExprError(); 4898 4899 if (S.BasePathInvolvesVirtualBase(BasePath)) { 4900 QualType T = SourceType; 4901 if (const PointerType *Pointer = T->getAs<PointerType>()) 4902 T = Pointer->getPointeeType(); 4903 if (const RecordType *RecordTy = T->getAs<RecordType>()) 4904 S.MarkVTableUsed(CurInit.get()->getLocStart(), 4905 cast<CXXRecordDecl>(RecordTy->getDecl())); 4906 } 4907 4908 ExprValueKind VK = 4909 Step->Kind == SK_CastDerivedToBaseLValue ? 4910 VK_LValue : 4911 (Step->Kind == SK_CastDerivedToBaseXValue ? 4912 VK_XValue : 4913 VK_RValue); 4914 CurInit = S.Owned(ImplicitCastExpr::Create(S.Context, 4915 Step->Type, 4916 CK_DerivedToBase, 4917 CurInit.get(), 4918 &BasePath, VK)); 4919 break; 4920 } 4921 4922 case SK_BindReference: 4923 if (FieldDecl *BitField = CurInit.get()->getBitField()) { 4924 // References cannot bind to bit fields (C++ [dcl.init.ref]p5). 4925 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield) 4926 << Entity.getType().isVolatileQualified() 4927 << BitField->getDeclName() 4928 << CurInit.get()->getSourceRange(); 4929 S.Diag(BitField->getLocation(), diag::note_bitfield_decl); 4930 return ExprError(); 4931 } 4932 4933 if (CurInit.get()->refersToVectorElement()) { 4934 // References cannot bind to vector elements. 4935 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_vector_element) 4936 << Entity.getType().isVolatileQualified() 4937 << CurInit.get()->getSourceRange(); 4938 PrintInitLocationNote(S, Entity); 4939 return ExprError(); 4940 } 4941 4942 // Reference binding does not have any corresponding ASTs. 4943 4944 // Check exception specifications 4945 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType)) 4946 return ExprError(); 4947 4948 break; 4949 4950 case SK_BindReferenceToTemporary: 4951 // Check exception specifications 4952 if (S.CheckExceptionSpecCompatibility(CurInit.get(), DestType)) 4953 return ExprError(); 4954 4955 // Materialize the temporary into memory. 4956 CurInit = new (S.Context) MaterializeTemporaryExpr( 4957 Entity.getType().getNonReferenceType(), 4958 CurInit.get(), 4959 Entity.getType()->isLValueReferenceType()); 4960 4961 // If we're binding to an Objective-C object that has lifetime, we 4962 // need cleanups. 4963 if (S.getLangOptions().ObjCAutoRefCount && 4964 CurInit.get()->getType()->isObjCLifetimeType()) 4965 S.ExprNeedsCleanups = true; 4966 4967 break; 4968 4969 case SK_ExtraneousCopyToTemporary: 4970 CurInit = CopyObject(S, Step->Type, Entity, move(CurInit), 4971 /*IsExtraneousCopy=*/true); 4972 break; 4973 4974 case SK_UserConversion: { 4975 // We have a user-defined conversion that invokes either a constructor 4976 // or a conversion function. 4977 CastKind CastKind; 4978 bool IsCopy = false; 4979 FunctionDecl *Fn = Step->Function.Function; 4980 DeclAccessPair FoundFn = Step->Function.FoundDecl; 4981 bool HadMultipleCandidates = Step->Function.HadMultipleCandidates; 4982 bool CreatedObject = false; 4983 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Fn)) { 4984 // Build a call to the selected constructor. 4985 ASTOwningVector<Expr*> ConstructorArgs(S); 4986 SourceLocation Loc = CurInit.get()->getLocStart(); 4987 CurInit.release(); // Ownership transferred into MultiExprArg, below. 4988 4989 // Determine the arguments required to actually perform the constructor 4990 // call. 4991 Expr *Arg = CurInit.get(); 4992 if (S.CompleteConstructorCall(Constructor, 4993 MultiExprArg(&Arg, 1), 4994 Loc, ConstructorArgs)) 4995 return ExprError(); 4996 4997 // Build an expression that constructs a temporary. 4998 CurInit = S.BuildCXXConstructExpr(Loc, Step->Type, Constructor, 4999 move_arg(ConstructorArgs), 5000 HadMultipleCandidates, 5001 /*ZeroInit*/ false, 5002 CXXConstructExpr::CK_Complete, 5003 SourceRange()); 5004 if (CurInit.isInvalid()) 5005 return ExprError(); 5006 5007 S.CheckConstructorAccess(Kind.getLocation(), Constructor, Entity, 5008 FoundFn.getAccess()); 5009 S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()); 5010 5011 CastKind = CK_ConstructorConversion; 5012 QualType Class = S.Context.getTypeDeclType(Constructor->getParent()); 5013 if (S.Context.hasSameUnqualifiedType(SourceType, Class) || 5014 S.IsDerivedFrom(SourceType, Class)) 5015 IsCopy = true; 5016 5017 CreatedObject = true; 5018 } else { 5019 // Build a call to the conversion function. 5020 CXXConversionDecl *Conversion = cast<CXXConversionDecl>(Fn); 5021 S.CheckMemberOperatorAccess(Kind.getLocation(), CurInit.get(), 0, 5022 FoundFn); 5023 S.DiagnoseUseOfDecl(FoundFn, Kind.getLocation()); 5024 5025 // FIXME: Should we move this initialization into a separate 5026 // derived-to-base conversion? I believe the answer is "no", because 5027 // we don't want to turn off access control here for c-style casts. 5028 ExprResult CurInitExprRes = 5029 S.PerformObjectArgumentInitialization(CurInit.take(), /*Qualifier=*/0, 5030 FoundFn, Conversion); 5031 if(CurInitExprRes.isInvalid()) 5032 return ExprError(); 5033 CurInit = move(CurInitExprRes); 5034 5035 // Build the actual call to the conversion function. 5036 CurInit = S.BuildCXXMemberCallExpr(CurInit.get(), FoundFn, Conversion, 5037 HadMultipleCandidates); 5038 if (CurInit.isInvalid() || !CurInit.get()) 5039 return ExprError(); 5040 5041 CastKind = CK_UserDefinedConversion; 5042 5043 CreatedObject = Conversion->getResultType()->isRecordType(); 5044 } 5045 5046 bool RequiresCopy = !IsCopy && !isReferenceBinding(Steps.back()); 5047 bool MaybeBindToTemp = RequiresCopy || shouldBindAsTemporary(Entity); 5048 5049 if (!MaybeBindToTemp && CreatedObject && shouldDestroyTemporary(Entity)) { 5050 QualType T = CurInit.get()->getType(); 5051 if (const RecordType *Record = T->getAs<RecordType>()) { 5052 CXXDestructorDecl *Destructor 5053 = S.LookupDestructor(cast<CXXRecordDecl>(Record->getDecl())); 5054 S.CheckDestructorAccess(CurInit.get()->getLocStart(), Destructor, 5055 S.PDiag(diag::err_access_dtor_temp) << T); 5056 S.MarkFunctionReferenced(CurInit.get()->getLocStart(), Destructor); 5057 S.DiagnoseUseOfDecl(Destructor, CurInit.get()->getLocStart()); 5058 } 5059 } 5060 5061 CurInit = S.Owned(ImplicitCastExpr::Create(S.Context, 5062 CurInit.get()->getType(), 5063 CastKind, CurInit.get(), 0, 5064 CurInit.get()->getValueKind())); 5065 if (MaybeBindToTemp) 5066 CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>()); 5067 if (RequiresCopy) 5068 CurInit = CopyObject(S, Entity.getType().getNonReferenceType(), Entity, 5069 move(CurInit), /*IsExtraneousCopy=*/false); 5070 break; 5071 } 5072 5073 case SK_QualificationConversionLValue: 5074 case SK_QualificationConversionXValue: 5075 case SK_QualificationConversionRValue: { 5076 // Perform a qualification conversion; these can never go wrong. 5077 ExprValueKind VK = 5078 Step->Kind == SK_QualificationConversionLValue ? 5079 VK_LValue : 5080 (Step->Kind == SK_QualificationConversionXValue ? 5081 VK_XValue : 5082 VK_RValue); 5083 CurInit = S.ImpCastExprToType(CurInit.take(), Step->Type, CK_NoOp, VK); 5084 break; 5085 } 5086 5087 case SK_ConversionSequence: { 5088 Sema::CheckedConversionKind CCK 5089 = Kind.isCStyleCast()? Sema::CCK_CStyleCast 5090 : Kind.isFunctionalCast()? Sema::CCK_FunctionalCast 5091 : Kind.isExplicitCast()? Sema::CCK_OtherCast 5092 : Sema::CCK_ImplicitConversion; 5093 ExprResult CurInitExprRes = 5094 S.PerformImplicitConversion(CurInit.get(), Step->Type, *Step->ICS, 5095 getAssignmentAction(Entity), CCK); 5096 if (CurInitExprRes.isInvalid()) 5097 return ExprError(); 5098 CurInit = move(CurInitExprRes); 5099 break; 5100 } 5101 5102 case SK_ListInitialization: { 5103 InitListExpr *InitList = cast<InitListExpr>(CurInit.get()); 5104 // Hack: We must pass *ResultType if available in order to set the type 5105 // of arrays, e.g. in 'int ar[] = {1, 2, 3};'. 5106 // But in 'const X &x = {1, 2, 3};' we're supposed to initialize a 5107 // temporary, not a reference, so we should pass Ty. 5108 // Worst case: 'const int (&arref)[] = {1, 2, 3};'. 5109 // Since this step is never used for a reference directly, we explicitly 5110 // unwrap references here and rewrap them afterwards. 5111 // We also need to create a InitializeTemporary entity for this. 5112 QualType Ty = ResultType ? ResultType->getNonReferenceType() : Step->Type; 5113 bool IsTemporary = ResultType && (*ResultType)->isReferenceType(); 5114 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary(Ty); 5115 InitListChecker PerformInitList(S, IsTemporary ? TempEntity : Entity, 5116 InitList, Ty, /*VerifyOnly=*/false, 5117 Kind.getKind() != InitializationKind::IK_DirectList || 5118 !S.getLangOptions().CPlusPlus0x); 5119 if (PerformInitList.HadError()) 5120 return ExprError(); 5121 5122 if (ResultType) { 5123 if ((*ResultType)->isRValueReferenceType()) 5124 Ty = S.Context.getRValueReferenceType(Ty); 5125 else if ((*ResultType)->isLValueReferenceType()) 5126 Ty = S.Context.getLValueReferenceType(Ty, 5127 (*ResultType)->getAs<LValueReferenceType>()->isSpelledAsLValue()); 5128 *ResultType = Ty; 5129 } 5130 5131 InitListExpr *StructuredInitList = 5132 PerformInitList.getFullyStructuredList(); 5133 CurInit.release(); 5134 CurInit = S.Owned(StructuredInitList); 5135 break; 5136 } 5137 5138 case SK_ListConstructorCall: { 5139 // When an initializer list is passed for a parameter of type "reference 5140 // to object", we don't get an EK_Temporary entity, but instead an 5141 // EK_Parameter entity with reference type. 5142 // FIXME: This is a hack. What we really should do is create a user 5143 // conversion step for this case, but this makes it considerably more 5144 // complicated. For now, this will do. 5145 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary( 5146 Entity.getType().getNonReferenceType()); 5147 bool UseTemporary = Entity.getType()->isReferenceType(); 5148 InitListExpr *InitList = cast<InitListExpr>(CurInit.get()); 5149 MultiExprArg Arg(InitList->getInits(), InitList->getNumInits()); 5150 CurInit = PerformConstructorInitialization(S, UseTemporary ? TempEntity : 5151 Entity, 5152 Kind, move(Arg), *Step, 5153 ConstructorInitRequiresZeroInit); 5154 break; 5155 } 5156 5157 case SK_UnwrapInitList: 5158 CurInit = S.Owned(cast<InitListExpr>(CurInit.take())->getInit(0)); 5159 break; 5160 5161 case SK_RewrapInitList: { 5162 Expr *E = CurInit.take(); 5163 InitListExpr *Syntactic = Step->WrappingSyntacticList; 5164 InitListExpr *ILE = new (S.Context) InitListExpr(S.Context, 5165 Syntactic->getLBraceLoc(), &E, 1, Syntactic->getRBraceLoc()); 5166 ILE->setSyntacticForm(Syntactic); 5167 ILE->setType(E->getType()); 5168 ILE->setValueKind(E->getValueKind()); 5169 CurInit = S.Owned(ILE); 5170 break; 5171 } 5172 5173 case SK_ConstructorInitialization: { 5174 // When an initializer list is passed for a parameter of type "reference 5175 // to object", we don't get an EK_Temporary entity, but instead an 5176 // EK_Parameter entity with reference type. 5177 // FIXME: This is a hack. What we really should do is create a user 5178 // conversion step for this case, but this makes it considerably more 5179 // complicated. For now, this will do. 5180 InitializedEntity TempEntity = InitializedEntity::InitializeTemporary( 5181 Entity.getType().getNonReferenceType()); 5182 bool UseTemporary = Entity.getType()->isReferenceType(); 5183 CurInit = PerformConstructorInitialization(S, UseTemporary ? TempEntity 5184 : Entity, 5185 Kind, move(Args), *Step, 5186 ConstructorInitRequiresZeroInit); 5187 break; 5188 } 5189 5190 case SK_ZeroInitialization: { 5191 step_iterator NextStep = Step; 5192 ++NextStep; 5193 if (NextStep != StepEnd && 5194 NextStep->Kind == SK_ConstructorInitialization) { 5195 // The need for zero-initialization is recorded directly into 5196 // the call to the object's constructor within the next step. 5197 ConstructorInitRequiresZeroInit = true; 5198 } else if (Kind.getKind() == InitializationKind::IK_Value && 5199 S.getLangOptions().CPlusPlus && 5200 !Kind.isImplicitValueInit()) { 5201 TypeSourceInfo *TSInfo = Entity.getTypeSourceInfo(); 5202 if (!TSInfo) 5203 TSInfo = S.Context.getTrivialTypeSourceInfo(Step->Type, 5204 Kind.getRange().getBegin()); 5205 5206 CurInit = S.Owned(new (S.Context) CXXScalarValueInitExpr( 5207 TSInfo->getType().getNonLValueExprType(S.Context), 5208 TSInfo, 5209 Kind.getRange().getEnd())); 5210 } else { 5211 CurInit = S.Owned(new (S.Context) ImplicitValueInitExpr(Step->Type)); 5212 } 5213 break; 5214 } 5215 5216 case SK_CAssignment: { 5217 QualType SourceType = CurInit.get()->getType(); 5218 ExprResult Result = move(CurInit); 5219 Sema::AssignConvertType ConvTy = 5220 S.CheckSingleAssignmentConstraints(Step->Type, Result); 5221 if (Result.isInvalid()) 5222 return ExprError(); 5223 CurInit = move(Result); 5224 5225 // If this is a call, allow conversion to a transparent union. 5226 ExprResult CurInitExprRes = move(CurInit); 5227 if (ConvTy != Sema::Compatible && 5228 Entity.getKind() == InitializedEntity::EK_Parameter && 5229 S.CheckTransparentUnionArgumentConstraints(Step->Type, CurInitExprRes) 5230 == Sema::Compatible) 5231 ConvTy = Sema::Compatible; 5232 if (CurInitExprRes.isInvalid()) 5233 return ExprError(); 5234 CurInit = move(CurInitExprRes); 5235 5236 bool Complained; 5237 if (S.DiagnoseAssignmentResult(ConvTy, Kind.getLocation(), 5238 Step->Type, SourceType, 5239 CurInit.get(), 5240 getAssignmentAction(Entity), 5241 &Complained)) { 5242 PrintInitLocationNote(S, Entity); 5243 return ExprError(); 5244 } else if (Complained) 5245 PrintInitLocationNote(S, Entity); 5246 break; 5247 } 5248 5249 case SK_StringInit: { 5250 QualType Ty = Step->Type; 5251 CheckStringInit(CurInit.get(), ResultType ? *ResultType : Ty, 5252 S.Context.getAsArrayType(Ty), S); 5253 break; 5254 } 5255 5256 case SK_ObjCObjectConversion: 5257 CurInit = S.ImpCastExprToType(CurInit.take(), Step->Type, 5258 CK_ObjCObjectLValueCast, 5259 CurInit.get()->getValueKind()); 5260 break; 5261 5262 case SK_ArrayInit: 5263 // Okay: we checked everything before creating this step. Note that 5264 // this is a GNU extension. 5265 S.Diag(Kind.getLocation(), diag::ext_array_init_copy) 5266 << Step->Type << CurInit.get()->getType() 5267 << CurInit.get()->getSourceRange(); 5268 5269 // If the destination type is an incomplete array type, update the 5270 // type accordingly. 5271 if (ResultType) { 5272 if (const IncompleteArrayType *IncompleteDest 5273 = S.Context.getAsIncompleteArrayType(Step->Type)) { 5274 if (const ConstantArrayType *ConstantSource 5275 = S.Context.getAsConstantArrayType(CurInit.get()->getType())) { 5276 *ResultType = S.Context.getConstantArrayType( 5277 IncompleteDest->getElementType(), 5278 ConstantSource->getSize(), 5279 ArrayType::Normal, 0); 5280 } 5281 } 5282 } 5283 break; 5284 5285 case SK_ParenthesizedArrayInit: 5286 // Okay: we checked everything before creating this step. Note that 5287 // this is a GNU extension. 5288 S.Diag(Kind.getLocation(), diag::ext_array_init_parens) 5289 << CurInit.get()->getSourceRange(); 5290 break; 5291 5292 case SK_PassByIndirectCopyRestore: 5293 case SK_PassByIndirectRestore: 5294 checkIndirectCopyRestoreSource(S, CurInit.get()); 5295 CurInit = S.Owned(new (S.Context) 5296 ObjCIndirectCopyRestoreExpr(CurInit.take(), Step->Type, 5297 Step->Kind == SK_PassByIndirectCopyRestore)); 5298 break; 5299 5300 case SK_ProduceObjCObject: 5301 CurInit = S.Owned(ImplicitCastExpr::Create(S.Context, Step->Type, 5302 CK_ARCProduceObject, 5303 CurInit.take(), 0, VK_RValue)); 5304 break; 5305 5306 case SK_StdInitializerList: { 5307 QualType Dest = Step->Type; 5308 QualType E; 5309 bool Success = S.isStdInitializerList(Dest, &E); 5310 (void)Success; 5311 assert(Success && "Destination type changed?"); 5312 5313 // If the element type has a destructor, check it. 5314 if (CXXRecordDecl *RD = E->getAsCXXRecordDecl()) { 5315 if (!RD->hasIrrelevantDestructor()) { 5316 if (CXXDestructorDecl *Destructor = S.LookupDestructor(RD)) { 5317 S.MarkFunctionReferenced(Kind.getLocation(), Destructor); 5318 S.CheckDestructorAccess(Kind.getLocation(), Destructor, 5319 S.PDiag(diag::err_access_dtor_temp) << E); 5320 S.DiagnoseUseOfDecl(Destructor, Kind.getLocation()); 5321 } 5322 } 5323 } 5324 5325 InitListExpr *ILE = cast<InitListExpr>(CurInit.take()); 5326 unsigned NumInits = ILE->getNumInits(); 5327 SmallVector<Expr*, 16> Converted(NumInits); 5328 InitializedEntity HiddenArray = InitializedEntity::InitializeTemporary( 5329 S.Context.getConstantArrayType(E, 5330 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()), 5331 NumInits), 5332 ArrayType::Normal, 0)); 5333 InitializedEntity Element =InitializedEntity::InitializeElement(S.Context, 5334 0, HiddenArray); 5335 for (unsigned i = 0; i < NumInits; ++i) { 5336 Element.setElementIndex(i); 5337 ExprResult Init = S.Owned(ILE->getInit(i)); 5338 ExprResult Res = S.PerformCopyInitialization(Element, 5339 Init.get()->getExprLoc(), 5340 Init); 5341 assert(!Res.isInvalid() && "Result changed since try phase."); 5342 Converted[i] = Res.take(); 5343 } 5344 InitListExpr *Semantic = new (S.Context) 5345 InitListExpr(S.Context, ILE->getLBraceLoc(), 5346 Converted.data(), NumInits, ILE->getRBraceLoc()); 5347 Semantic->setSyntacticForm(ILE); 5348 Semantic->setType(Dest); 5349 Semantic->setInitializesStdInitializerList(); 5350 CurInit = S.Owned(Semantic); 5351 break; 5352 } 5353 } 5354 } 5355 5356 // Diagnose non-fatal problems with the completed initialization. 5357 if (Entity.getKind() == InitializedEntity::EK_Member && 5358 cast<FieldDecl>(Entity.getDecl())->isBitField()) 5359 S.CheckBitFieldInitialization(Kind.getLocation(), 5360 cast<FieldDecl>(Entity.getDecl()), 5361 CurInit.get()); 5362 5363 return move(CurInit); 5364} 5365 5366/// \brief Provide some notes that detail why a function was implicitly 5367/// deleted. 5368static void diagnoseImplicitlyDeletedFunction(Sema &S, CXXMethodDecl *Method) { 5369 // FIXME: This is a work in progress. It should dig deeper to figure out 5370 // why the function was deleted (e.g., because one of its members doesn't 5371 // have a copy constructor, for the copy-constructor case). 5372 if (!Method->isImplicit()) { 5373 S.Diag(Method->getLocation(), diag::note_callee_decl) 5374 << Method->getDeclName(); 5375 } 5376 5377 if (Method->getParent()->isLambda()) { 5378 S.Diag(Method->getParent()->getLocation(), diag::note_lambda_decl); 5379 return; 5380 } 5381 5382 S.Diag(Method->getParent()->getLocation(), diag::note_defined_here) 5383 << Method->getParent(); 5384} 5385 5386//===----------------------------------------------------------------------===// 5387// Diagnose initialization failures 5388//===----------------------------------------------------------------------===// 5389bool InitializationSequence::Diagnose(Sema &S, 5390 const InitializedEntity &Entity, 5391 const InitializationKind &Kind, 5392 Expr **Args, unsigned NumArgs) { 5393 if (!Failed()) 5394 return false; 5395 5396 QualType DestType = Entity.getType(); 5397 switch (Failure) { 5398 case FK_TooManyInitsForReference: 5399 // FIXME: Customize for the initialized entity? 5400 if (NumArgs == 0) 5401 S.Diag(Kind.getLocation(), diag::err_reference_without_init) 5402 << DestType.getNonReferenceType(); 5403 else // FIXME: diagnostic below could be better! 5404 S.Diag(Kind.getLocation(), diag::err_reference_has_multiple_inits) 5405 << SourceRange(Args[0]->getLocStart(), Args[NumArgs - 1]->getLocEnd()); 5406 break; 5407 5408 case FK_ArrayNeedsInitList: 5409 case FK_ArrayNeedsInitListOrStringLiteral: 5410 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) 5411 << (Failure == FK_ArrayNeedsInitListOrStringLiteral); 5412 break; 5413 5414 case FK_ArrayTypeMismatch: 5415 case FK_NonConstantArrayInit: 5416 S.Diag(Kind.getLocation(), 5417 (Failure == FK_ArrayTypeMismatch 5418 ? diag::err_array_init_different_type 5419 : diag::err_array_init_non_constant_array)) 5420 << DestType.getNonReferenceType() 5421 << Args[0]->getType() 5422 << Args[0]->getSourceRange(); 5423 break; 5424 5425 case FK_VariableLengthArrayHasInitializer: 5426 S.Diag(Kind.getLocation(), diag::err_variable_object_no_init) 5427 << Args[0]->getSourceRange(); 5428 break; 5429 5430 case FK_AddressOfOverloadFailed: { 5431 DeclAccessPair Found; 5432 S.ResolveAddressOfOverloadedFunction(Args[0], 5433 DestType.getNonReferenceType(), 5434 true, 5435 Found); 5436 break; 5437 } 5438 5439 case FK_ReferenceInitOverloadFailed: 5440 case FK_UserConversionOverloadFailed: 5441 switch (FailedOverloadResult) { 5442 case OR_Ambiguous: 5443 if (Failure == FK_UserConversionOverloadFailed) 5444 S.Diag(Kind.getLocation(), diag::err_typecheck_ambiguous_condition) 5445 << Args[0]->getType() << DestType 5446 << Args[0]->getSourceRange(); 5447 else 5448 S.Diag(Kind.getLocation(), diag::err_ref_init_ambiguous) 5449 << DestType << Args[0]->getType() 5450 << Args[0]->getSourceRange(); 5451 5452 FailedCandidateSet.NoteCandidates(S, OCD_ViableCandidates, 5453 llvm::makeArrayRef(Args, NumArgs)); 5454 break; 5455 5456 case OR_No_Viable_Function: 5457 S.Diag(Kind.getLocation(), diag::err_typecheck_nonviable_condition) 5458 << Args[0]->getType() << DestType.getNonReferenceType() 5459 << Args[0]->getSourceRange(); 5460 FailedCandidateSet.NoteCandidates(S, OCD_AllCandidates, 5461 llvm::makeArrayRef(Args, NumArgs)); 5462 break; 5463 5464 case OR_Deleted: { 5465 S.Diag(Kind.getLocation(), diag::err_typecheck_deleted_function) 5466 << Args[0]->getType() << DestType.getNonReferenceType() 5467 << Args[0]->getSourceRange(); 5468 OverloadCandidateSet::iterator Best; 5469 OverloadingResult Ovl 5470 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best, 5471 true); 5472 if (Ovl == OR_Deleted) { 5473 S.Diag(Best->Function->getLocation(), diag::note_unavailable_here) 5474 << 1 << Best->Function->isDeleted(); 5475 } else { 5476 llvm_unreachable("Inconsistent overload resolution?"); 5477 } 5478 break; 5479 } 5480 5481 case OR_Success: 5482 llvm_unreachable("Conversion did not fail!"); 5483 } 5484 break; 5485 5486 case FK_NonConstLValueReferenceBindingToTemporary: 5487 if (isa<InitListExpr>(Args[0])) { 5488 S.Diag(Kind.getLocation(), 5489 diag::err_lvalue_reference_bind_to_initlist) 5490 << DestType.getNonReferenceType().isVolatileQualified() 5491 << DestType.getNonReferenceType() 5492 << Args[0]->getSourceRange(); 5493 break; 5494 } 5495 // Intentional fallthrough 5496 5497 case FK_NonConstLValueReferenceBindingToUnrelated: 5498 S.Diag(Kind.getLocation(), 5499 Failure == FK_NonConstLValueReferenceBindingToTemporary 5500 ? diag::err_lvalue_reference_bind_to_temporary 5501 : diag::err_lvalue_reference_bind_to_unrelated) 5502 << DestType.getNonReferenceType().isVolatileQualified() 5503 << DestType.getNonReferenceType() 5504 << Args[0]->getType() 5505 << Args[0]->getSourceRange(); 5506 break; 5507 5508 case FK_RValueReferenceBindingToLValue: 5509 S.Diag(Kind.getLocation(), diag::err_lvalue_to_rvalue_ref) 5510 << DestType.getNonReferenceType() << Args[0]->getType() 5511 << Args[0]->getSourceRange(); 5512 break; 5513 5514 case FK_ReferenceInitDropsQualifiers: 5515 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals) 5516 << DestType.getNonReferenceType() 5517 << Args[0]->getType() 5518 << Args[0]->getSourceRange(); 5519 break; 5520 5521 case FK_ReferenceInitFailed: 5522 S.Diag(Kind.getLocation(), diag::err_reference_bind_failed) 5523 << DestType.getNonReferenceType() 5524 << Args[0]->isLValue() 5525 << Args[0]->getType() 5526 << Args[0]->getSourceRange(); 5527 if (DestType.getNonReferenceType()->isObjCObjectPointerType() && 5528 Args[0]->getType()->isObjCObjectPointerType()) 5529 S.EmitRelatedResultTypeNote(Args[0]); 5530 break; 5531 5532 case FK_ConversionFailed: { 5533 QualType FromType = Args[0]->getType(); 5534 PartialDiagnostic PDiag = S.PDiag(diag::err_init_conversion_failed) 5535 << (int)Entity.getKind() 5536 << DestType 5537 << Args[0]->isLValue() 5538 << FromType 5539 << Args[0]->getSourceRange(); 5540 S.HandleFunctionTypeMismatch(PDiag, FromType, DestType); 5541 S.Diag(Kind.getLocation(), PDiag); 5542 if (DestType.getNonReferenceType()->isObjCObjectPointerType() && 5543 Args[0]->getType()->isObjCObjectPointerType()) 5544 S.EmitRelatedResultTypeNote(Args[0]); 5545 break; 5546 } 5547 5548 case FK_ConversionFromPropertyFailed: 5549 // No-op. This error has already been reported. 5550 break; 5551 5552 case FK_TooManyInitsForScalar: { 5553 SourceRange R; 5554 5555 if (InitListExpr *InitList = dyn_cast<InitListExpr>(Args[0])) 5556 R = SourceRange(InitList->getInit(0)->getLocEnd(), 5557 InitList->getLocEnd()); 5558 else 5559 R = SourceRange(Args[0]->getLocEnd(), Args[NumArgs - 1]->getLocEnd()); 5560 5561 R.setBegin(S.PP.getLocForEndOfToken(R.getBegin())); 5562 if (Kind.isCStyleOrFunctionalCast()) 5563 S.Diag(Kind.getLocation(), diag::err_builtin_func_cast_more_than_one_arg) 5564 << R; 5565 else 5566 S.Diag(Kind.getLocation(), diag::err_excess_initializers) 5567 << /*scalar=*/2 << R; 5568 break; 5569 } 5570 5571 case FK_ReferenceBindingToInitList: 5572 S.Diag(Kind.getLocation(), diag::err_reference_bind_init_list) 5573 << DestType.getNonReferenceType() << Args[0]->getSourceRange(); 5574 break; 5575 5576 case FK_InitListBadDestinationType: 5577 S.Diag(Kind.getLocation(), diag::err_init_list_bad_dest_type) 5578 << (DestType->isRecordType()) << DestType << Args[0]->getSourceRange(); 5579 break; 5580 5581 case FK_ListConstructorOverloadFailed: 5582 case FK_ConstructorOverloadFailed: { 5583 SourceRange ArgsRange; 5584 if (NumArgs) 5585 ArgsRange = SourceRange(Args[0]->getLocStart(), 5586 Args[NumArgs - 1]->getLocEnd()); 5587 5588 if (Failure == FK_ListConstructorOverloadFailed) { 5589 assert(NumArgs == 1 && "List construction from other than 1 argument."); 5590 InitListExpr *InitList = cast<InitListExpr>(Args[0]); 5591 Args = InitList->getInits(); 5592 NumArgs = InitList->getNumInits(); 5593 } 5594 5595 // FIXME: Using "DestType" for the entity we're printing is probably 5596 // bad. 5597 switch (FailedOverloadResult) { 5598 case OR_Ambiguous: 5599 S.Diag(Kind.getLocation(), diag::err_ovl_ambiguous_init) 5600 << DestType << ArgsRange; 5601 FailedCandidateSet.NoteCandidates(S, OCD_ViableCandidates, 5602 llvm::makeArrayRef(Args, NumArgs)); 5603 break; 5604 5605 case OR_No_Viable_Function: 5606 if (Kind.getKind() == InitializationKind::IK_Default && 5607 (Entity.getKind() == InitializedEntity::EK_Base || 5608 Entity.getKind() == InitializedEntity::EK_Member) && 5609 isa<CXXConstructorDecl>(S.CurContext)) { 5610 // This is implicit default initialization of a member or 5611 // base within a constructor. If no viable function was 5612 // found, notify the user that she needs to explicitly 5613 // initialize this base/member. 5614 CXXConstructorDecl *Constructor 5615 = cast<CXXConstructorDecl>(S.CurContext); 5616 if (Entity.getKind() == InitializedEntity::EK_Base) { 5617 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor) 5618 << Constructor->isImplicit() 5619 << S.Context.getTypeDeclType(Constructor->getParent()) 5620 << /*base=*/0 5621 << Entity.getType(); 5622 5623 RecordDecl *BaseDecl 5624 = Entity.getBaseSpecifier()->getType()->getAs<RecordType>() 5625 ->getDecl(); 5626 S.Diag(BaseDecl->getLocation(), diag::note_previous_decl) 5627 << S.Context.getTagDeclType(BaseDecl); 5628 } else { 5629 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor) 5630 << Constructor->isImplicit() 5631 << S.Context.getTypeDeclType(Constructor->getParent()) 5632 << /*member=*/1 5633 << Entity.getName(); 5634 S.Diag(Entity.getDecl()->getLocation(), diag::note_field_decl); 5635 5636 if (const RecordType *Record 5637 = Entity.getType()->getAs<RecordType>()) 5638 S.Diag(Record->getDecl()->getLocation(), 5639 diag::note_previous_decl) 5640 << S.Context.getTagDeclType(Record->getDecl()); 5641 } 5642 break; 5643 } 5644 5645 S.Diag(Kind.getLocation(), diag::err_ovl_no_viable_function_in_init) 5646 << DestType << ArgsRange; 5647 FailedCandidateSet.NoteCandidates(S, OCD_AllCandidates, 5648 llvm::makeArrayRef(Args, NumArgs)); 5649 break; 5650 5651 case OR_Deleted: { 5652 OverloadCandidateSet::iterator Best; 5653 OverloadingResult Ovl 5654 = FailedCandidateSet.BestViableFunction(S, Kind.getLocation(), Best); 5655 if (Ovl != OR_Deleted) { 5656 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init) 5657 << true << DestType << ArgsRange; 5658 llvm_unreachable("Inconsistent overload resolution?"); 5659 break; 5660 } 5661 5662 // If this is a defaulted or implicitly-declared function, then 5663 // it was implicitly deleted. Make it clear that the deletion was 5664 // implicit. 5665 if (S.isImplicitlyDeleted(Best->Function)) { 5666 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_special_init) 5667 << S.getSpecialMember(cast<CXXMethodDecl>(Best->Function)) 5668 << DestType << ArgsRange; 5669 5670 diagnoseImplicitlyDeletedFunction(S, 5671 cast<CXXMethodDecl>(Best->Function)); 5672 break; 5673 } 5674 5675 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init) 5676 << true << DestType << ArgsRange; 5677 S.Diag(Best->Function->getLocation(), diag::note_unavailable_here) 5678 << 1 << Best->Function->isDeleted(); 5679 break; 5680 } 5681 5682 case OR_Success: 5683 llvm_unreachable("Conversion did not fail!"); 5684 } 5685 } 5686 break; 5687 5688 case FK_DefaultInitOfConst: 5689 if (Entity.getKind() == InitializedEntity::EK_Member && 5690 isa<CXXConstructorDecl>(S.CurContext)) { 5691 // This is implicit default-initialization of a const member in 5692 // a constructor. Complain that it needs to be explicitly 5693 // initialized. 5694 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(S.CurContext); 5695 S.Diag(Kind.getLocation(), diag::err_uninitialized_member_in_ctor) 5696 << Constructor->isImplicit() 5697 << S.Context.getTypeDeclType(Constructor->getParent()) 5698 << /*const=*/1 5699 << Entity.getName(); 5700 S.Diag(Entity.getDecl()->getLocation(), diag::note_previous_decl) 5701 << Entity.getName(); 5702 } else { 5703 S.Diag(Kind.getLocation(), diag::err_default_init_const) 5704 << DestType << (bool)DestType->getAs<RecordType>(); 5705 } 5706 break; 5707 5708 case FK_Incomplete: 5709 S.RequireCompleteType(Kind.getLocation(), DestType, 5710 diag::err_init_incomplete_type); 5711 break; 5712 5713 case FK_ListInitializationFailed: { 5714 // Run the init list checker again to emit diagnostics. 5715 InitListExpr* InitList = cast<InitListExpr>(Args[0]); 5716 QualType DestType = Entity.getType(); 5717 InitListChecker DiagnoseInitList(S, Entity, InitList, 5718 DestType, /*VerifyOnly=*/false, 5719 Kind.getKind() != InitializationKind::IK_DirectList || 5720 !S.getLangOptions().CPlusPlus0x); 5721 assert(DiagnoseInitList.HadError() && 5722 "Inconsistent init list check result."); 5723 break; 5724 } 5725 5726 case FK_PlaceholderType: { 5727 // FIXME: Already diagnosed! 5728 break; 5729 } 5730 5731 case FK_InitListElementCopyFailure: { 5732 // Try to perform all copies again. 5733 InitListExpr* InitList = cast<InitListExpr>(Args[0]); 5734 unsigned NumInits = InitList->getNumInits(); 5735 QualType DestType = Entity.getType(); 5736 QualType E; 5737 bool Success = S.isStdInitializerList(DestType, &E); 5738 (void)Success; 5739 assert(Success && "Where did the std::initializer_list go?"); 5740 InitializedEntity HiddenArray = InitializedEntity::InitializeTemporary( 5741 S.Context.getConstantArrayType(E, 5742 llvm::APInt(S.Context.getTypeSize(S.Context.getSizeType()), 5743 NumInits), 5744 ArrayType::Normal, 0)); 5745 InitializedEntity Element = InitializedEntity::InitializeElement(S.Context, 5746 0, HiddenArray); 5747 // Show at most 3 errors. Otherwise, you'd get a lot of errors for errors 5748 // where the init list type is wrong, e.g. 5749 // std::initializer_list<void*> list = { 1, 2, 3, 4, 5, 6, 7, 8 }; 5750 // FIXME: Emit a note if we hit the limit? 5751 int ErrorCount = 0; 5752 for (unsigned i = 0; i < NumInits && ErrorCount < 3; ++i) { 5753 Element.setElementIndex(i); 5754 ExprResult Init = S.Owned(InitList->getInit(i)); 5755 if (S.PerformCopyInitialization(Element, Init.get()->getExprLoc(), Init) 5756 .isInvalid()) 5757 ++ErrorCount; 5758 } 5759 break; 5760 } 5761 } 5762 5763 PrintInitLocationNote(S, Entity); 5764 return true; 5765} 5766 5767void InitializationSequence::dump(raw_ostream &OS) const { 5768 switch (SequenceKind) { 5769 case FailedSequence: { 5770 OS << "Failed sequence: "; 5771 switch (Failure) { 5772 case FK_TooManyInitsForReference: 5773 OS << "too many initializers for reference"; 5774 break; 5775 5776 case FK_ArrayNeedsInitList: 5777 OS << "array requires initializer list"; 5778 break; 5779 5780 case FK_ArrayNeedsInitListOrStringLiteral: 5781 OS << "array requires initializer list or string literal"; 5782 break; 5783 5784 case FK_ArrayTypeMismatch: 5785 OS << "array type mismatch"; 5786 break; 5787 5788 case FK_NonConstantArrayInit: 5789 OS << "non-constant array initializer"; 5790 break; 5791 5792 case FK_AddressOfOverloadFailed: 5793 OS << "address of overloaded function failed"; 5794 break; 5795 5796 case FK_ReferenceInitOverloadFailed: 5797 OS << "overload resolution for reference initialization failed"; 5798 break; 5799 5800 case FK_NonConstLValueReferenceBindingToTemporary: 5801 OS << "non-const lvalue reference bound to temporary"; 5802 break; 5803 5804 case FK_NonConstLValueReferenceBindingToUnrelated: 5805 OS << "non-const lvalue reference bound to unrelated type"; 5806 break; 5807 5808 case FK_RValueReferenceBindingToLValue: 5809 OS << "rvalue reference bound to an lvalue"; 5810 break; 5811 5812 case FK_ReferenceInitDropsQualifiers: 5813 OS << "reference initialization drops qualifiers"; 5814 break; 5815 5816 case FK_ReferenceInitFailed: 5817 OS << "reference initialization failed"; 5818 break; 5819 5820 case FK_ConversionFailed: 5821 OS << "conversion failed"; 5822 break; 5823 5824 case FK_ConversionFromPropertyFailed: 5825 OS << "conversion from property failed"; 5826 break; 5827 5828 case FK_TooManyInitsForScalar: 5829 OS << "too many initializers for scalar"; 5830 break; 5831 5832 case FK_ReferenceBindingToInitList: 5833 OS << "referencing binding to initializer list"; 5834 break; 5835 5836 case FK_InitListBadDestinationType: 5837 OS << "initializer list for non-aggregate, non-scalar type"; 5838 break; 5839 5840 case FK_UserConversionOverloadFailed: 5841 OS << "overloading failed for user-defined conversion"; 5842 break; 5843 5844 case FK_ConstructorOverloadFailed: 5845 OS << "constructor overloading failed"; 5846 break; 5847 5848 case FK_DefaultInitOfConst: 5849 OS << "default initialization of a const variable"; 5850 break; 5851 5852 case FK_Incomplete: 5853 OS << "initialization of incomplete type"; 5854 break; 5855 5856 case FK_ListInitializationFailed: 5857 OS << "list initialization checker failure"; 5858 break; 5859 5860 case FK_VariableLengthArrayHasInitializer: 5861 OS << "variable length array has an initializer"; 5862 break; 5863 5864 case FK_PlaceholderType: 5865 OS << "initializer expression isn't contextually valid"; 5866 break; 5867 5868 case FK_ListConstructorOverloadFailed: 5869 OS << "list constructor overloading failed"; 5870 break; 5871 5872 case FK_InitListElementCopyFailure: 5873 OS << "copy construction of initializer list element failed"; 5874 break; 5875 } 5876 OS << '\n'; 5877 return; 5878 } 5879 5880 case DependentSequence: 5881 OS << "Dependent sequence\n"; 5882 return; 5883 5884 case NormalSequence: 5885 OS << "Normal sequence: "; 5886 break; 5887 } 5888 5889 for (step_iterator S = step_begin(), SEnd = step_end(); S != SEnd; ++S) { 5890 if (S != step_begin()) { 5891 OS << " -> "; 5892 } 5893 5894 switch (S->Kind) { 5895 case SK_ResolveAddressOfOverloadedFunction: 5896 OS << "resolve address of overloaded function"; 5897 break; 5898 5899 case SK_CastDerivedToBaseRValue: 5900 OS << "derived-to-base case (rvalue" << S->Type.getAsString() << ")"; 5901 break; 5902 5903 case SK_CastDerivedToBaseXValue: 5904 OS << "derived-to-base case (xvalue" << S->Type.getAsString() << ")"; 5905 break; 5906 5907 case SK_CastDerivedToBaseLValue: 5908 OS << "derived-to-base case (lvalue" << S->Type.getAsString() << ")"; 5909 break; 5910 5911 case SK_BindReference: 5912 OS << "bind reference to lvalue"; 5913 break; 5914 5915 case SK_BindReferenceToTemporary: 5916 OS << "bind reference to a temporary"; 5917 break; 5918 5919 case SK_ExtraneousCopyToTemporary: 5920 OS << "extraneous C++03 copy to temporary"; 5921 break; 5922 5923 case SK_UserConversion: 5924 OS << "user-defined conversion via " << *S->Function.Function; 5925 break; 5926 5927 case SK_QualificationConversionRValue: 5928 OS << "qualification conversion (rvalue)"; 5929 break; 5930 5931 case SK_QualificationConversionXValue: 5932 OS << "qualification conversion (xvalue)"; 5933 break; 5934 5935 case SK_QualificationConversionLValue: 5936 OS << "qualification conversion (lvalue)"; 5937 break; 5938 5939 case SK_ConversionSequence: 5940 OS << "implicit conversion sequence ("; 5941 S->ICS->DebugPrint(); // FIXME: use OS 5942 OS << ")"; 5943 break; 5944 5945 case SK_ListInitialization: 5946 OS << "list aggregate initialization"; 5947 break; 5948 5949 case SK_ListConstructorCall: 5950 OS << "list initialization via constructor"; 5951 break; 5952 5953 case SK_UnwrapInitList: 5954 OS << "unwrap reference initializer list"; 5955 break; 5956 5957 case SK_RewrapInitList: 5958 OS << "rewrap reference initializer list"; 5959 break; 5960 5961 case SK_ConstructorInitialization: 5962 OS << "constructor initialization"; 5963 break; 5964 5965 case SK_ZeroInitialization: 5966 OS << "zero initialization"; 5967 break; 5968 5969 case SK_CAssignment: 5970 OS << "C assignment"; 5971 break; 5972 5973 case SK_StringInit: 5974 OS << "string initialization"; 5975 break; 5976 5977 case SK_ObjCObjectConversion: 5978 OS << "Objective-C object conversion"; 5979 break; 5980 5981 case SK_ArrayInit: 5982 OS << "array initialization"; 5983 break; 5984 5985 case SK_ParenthesizedArrayInit: 5986 OS << "parenthesized array initialization"; 5987 break; 5988 5989 case SK_PassByIndirectCopyRestore: 5990 OS << "pass by indirect copy and restore"; 5991 break; 5992 5993 case SK_PassByIndirectRestore: 5994 OS << "pass by indirect restore"; 5995 break; 5996 5997 case SK_ProduceObjCObject: 5998 OS << "Objective-C object retension"; 5999 break; 6000 6001 case SK_StdInitializerList: 6002 OS << "std::initializer_list from initializer list"; 6003 break; 6004 } 6005 } 6006} 6007 6008void InitializationSequence::dump() const { 6009 dump(llvm::errs()); 6010} 6011 6012static void DiagnoseNarrowingInInitList(Sema &S, InitializationSequence &Seq, 6013 QualType EntityType, 6014 const Expr *PreInit, 6015 const Expr *PostInit) { 6016 if (Seq.step_begin() == Seq.step_end() || PreInit->isValueDependent()) 6017 return; 6018 6019 // A narrowing conversion can only appear as the final implicit conversion in 6020 // an initialization sequence. 6021 const InitializationSequence::Step &LastStep = Seq.step_end()[-1]; 6022 if (LastStep.Kind != InitializationSequence::SK_ConversionSequence) 6023 return; 6024 6025 const ImplicitConversionSequence &ICS = *LastStep.ICS; 6026 const StandardConversionSequence *SCS = 0; 6027 switch (ICS.getKind()) { 6028 case ImplicitConversionSequence::StandardConversion: 6029 SCS = &ICS.Standard; 6030 break; 6031 case ImplicitConversionSequence::UserDefinedConversion: 6032 SCS = &ICS.UserDefined.After; 6033 break; 6034 case ImplicitConversionSequence::AmbiguousConversion: 6035 case ImplicitConversionSequence::EllipsisConversion: 6036 case ImplicitConversionSequence::BadConversion: 6037 return; 6038 } 6039 6040 // Determine the type prior to the narrowing conversion. If a conversion 6041 // operator was used, this may be different from both the type of the entity 6042 // and of the pre-initialization expression. 6043 QualType PreNarrowingType = PreInit->getType(); 6044 if (Seq.step_begin() + 1 != Seq.step_end()) 6045 PreNarrowingType = Seq.step_end()[-2].Type; 6046 6047 // C++11 [dcl.init.list]p7: Check whether this is a narrowing conversion. 6048 APValue ConstantValue; 6049 switch (SCS->getNarrowingKind(S.Context, PostInit, ConstantValue)) { 6050 case NK_Not_Narrowing: 6051 // No narrowing occurred. 6052 return; 6053 6054 case NK_Type_Narrowing: 6055 // This was a floating-to-integer conversion, which is always considered a 6056 // narrowing conversion even if the value is a constant and can be 6057 // represented exactly as an integer. 6058 S.Diag(PostInit->getLocStart(), 6059 S.getLangOptions().MicrosoftExt || !S.getLangOptions().CPlusPlus0x? 6060 diag::warn_init_list_type_narrowing 6061 : S.isSFINAEContext()? 6062 diag::err_init_list_type_narrowing_sfinae 6063 : diag::err_init_list_type_narrowing) 6064 << PostInit->getSourceRange() 6065 << PreNarrowingType.getLocalUnqualifiedType() 6066 << EntityType.getLocalUnqualifiedType(); 6067 break; 6068 6069 case NK_Constant_Narrowing: 6070 // A constant value was narrowed. 6071 S.Diag(PostInit->getLocStart(), 6072 S.getLangOptions().MicrosoftExt || !S.getLangOptions().CPlusPlus0x? 6073 diag::warn_init_list_constant_narrowing 6074 : S.isSFINAEContext()? 6075 diag::err_init_list_constant_narrowing_sfinae 6076 : diag::err_init_list_constant_narrowing) 6077 << PostInit->getSourceRange() 6078 << ConstantValue.getAsString(S.getASTContext(), EntityType) 6079 << EntityType.getLocalUnqualifiedType(); 6080 break; 6081 6082 case NK_Variable_Narrowing: 6083 // A variable's value may have been narrowed. 6084 S.Diag(PostInit->getLocStart(), 6085 S.getLangOptions().MicrosoftExt || !S.getLangOptions().CPlusPlus0x? 6086 diag::warn_init_list_variable_narrowing 6087 : S.isSFINAEContext()? 6088 diag::err_init_list_variable_narrowing_sfinae 6089 : diag::err_init_list_variable_narrowing) 6090 << PostInit->getSourceRange() 6091 << PreNarrowingType.getLocalUnqualifiedType() 6092 << EntityType.getLocalUnqualifiedType(); 6093 break; 6094 } 6095 6096 SmallString<128> StaticCast; 6097 llvm::raw_svector_ostream OS(StaticCast); 6098 OS << "static_cast<"; 6099 if (const TypedefType *TT = EntityType->getAs<TypedefType>()) { 6100 // It's important to use the typedef's name if there is one so that the 6101 // fixit doesn't break code using types like int64_t. 6102 // 6103 // FIXME: This will break if the typedef requires qualification. But 6104 // getQualifiedNameAsString() includes non-machine-parsable components. 6105 OS << *TT->getDecl(); 6106 } else if (const BuiltinType *BT = EntityType->getAs<BuiltinType>()) 6107 OS << BT->getName(S.getLangOptions()); 6108 else { 6109 // Oops, we didn't find the actual type of the variable. Don't emit a fixit 6110 // with a broken cast. 6111 return; 6112 } 6113 OS << ">("; 6114 S.Diag(PostInit->getLocStart(), diag::note_init_list_narrowing_override) 6115 << PostInit->getSourceRange() 6116 << FixItHint::CreateInsertion(PostInit->getLocStart(), OS.str()) 6117 << FixItHint::CreateInsertion( 6118 S.getPreprocessor().getLocForEndOfToken(PostInit->getLocEnd()), ")"); 6119} 6120 6121//===----------------------------------------------------------------------===// 6122// Initialization helper functions 6123//===----------------------------------------------------------------------===// 6124bool 6125Sema::CanPerformCopyInitialization(const InitializedEntity &Entity, 6126 ExprResult Init) { 6127 if (Init.isInvalid()) 6128 return false; 6129 6130 Expr *InitE = Init.get(); 6131 assert(InitE && "No initialization expression"); 6132 6133 InitializationKind Kind = InitializationKind::CreateCopy(SourceLocation(), 6134 SourceLocation()); 6135 InitializationSequence Seq(*this, Entity, Kind, &InitE, 1); 6136 return !Seq.Failed(); 6137} 6138 6139ExprResult 6140Sema::PerformCopyInitialization(const InitializedEntity &Entity, 6141 SourceLocation EqualLoc, 6142 ExprResult Init, 6143 bool TopLevelOfInitList, 6144 bool AllowExplicit) { 6145 if (Init.isInvalid()) 6146 return ExprError(); 6147 6148 Expr *InitE = Init.get(); 6149 assert(InitE && "No initialization expression?"); 6150 6151 if (EqualLoc.isInvalid()) 6152 EqualLoc = InitE->getLocStart(); 6153 6154 InitializationKind Kind = InitializationKind::CreateCopy(InitE->getLocStart(), 6155 EqualLoc, 6156 AllowExplicit); 6157 InitializationSequence Seq(*this, Entity, Kind, &InitE, 1); 6158 Init.release(); 6159 6160 ExprResult Result = Seq.Perform(*this, Entity, Kind, MultiExprArg(&InitE, 1)); 6161 6162 if (!Result.isInvalid() && TopLevelOfInitList) 6163 DiagnoseNarrowingInInitList(*this, Seq, Entity.getType(), 6164 InitE, Result.get()); 6165 6166 return Result; 6167} 6168