SemaInit.cpp revision 317e07ea35a2b1269d0b9095bdde70f2685f7015
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. The main entry 11// point is Sema::CheckInitList(), but all of the work is performed 12// within the InitListChecker class. 13// 14// This file also implements Sema::CheckInitializerTypes. 15// 16//===----------------------------------------------------------------------===// 17 18#include "SemaInit.h" 19#include "Lookup.h" 20#include "Sema.h" 21#include "clang/Lex/Preprocessor.h" 22#include "clang/Parse/Designator.h" 23#include "clang/AST/ASTContext.h" 24#include "clang/AST/ExprCXX.h" 25#include "clang/AST/ExprObjC.h" 26#include "clang/AST/TypeLoc.h" 27#include "llvm/Support/ErrorHandling.h" 28#include <map> 29using namespace clang; 30 31//===----------------------------------------------------------------------===// 32// Sema Initialization Checking 33//===----------------------------------------------------------------------===// 34 35static Expr *IsStringInit(Expr *Init, QualType DeclType, ASTContext &Context) { 36 const ArrayType *AT = Context.getAsArrayType(DeclType); 37 if (!AT) return 0; 38 39 if (!isa<ConstantArrayType>(AT) && !isa<IncompleteArrayType>(AT)) 40 return 0; 41 42 // See if this is a string literal or @encode. 43 Init = Init->IgnoreParens(); 44 45 // Handle @encode, which is a narrow string. 46 if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType()) 47 return Init; 48 49 // Otherwise we can only handle string literals. 50 StringLiteral *SL = dyn_cast<StringLiteral>(Init); 51 if (SL == 0) return 0; 52 53 QualType ElemTy = Context.getCanonicalType(AT->getElementType()); 54 // char array can be initialized with a narrow string. 55 // Only allow char x[] = "foo"; not char x[] = L"foo"; 56 if (!SL->isWide()) 57 return ElemTy->isCharType() ? Init : 0; 58 59 // wchar_t array can be initialized with a wide string: C99 6.7.8p15 (with 60 // correction from DR343): "An array with element type compatible with a 61 // qualified or unqualified version of wchar_t may be initialized by a wide 62 // string literal, optionally enclosed in braces." 63 if (Context.typesAreCompatible(Context.getWCharType(), 64 ElemTy.getUnqualifiedType())) 65 return Init; 66 67 return 0; 68} 69 70static void CheckStringInit(Expr *Str, QualType &DeclT, Sema &S) { 71 // Get the length of the string as parsed. 72 uint64_t StrLength = 73 cast<ConstantArrayType>(Str->getType())->getSize().getZExtValue(); 74 75 76 const ArrayType *AT = S.Context.getAsArrayType(DeclT); 77 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 78 // C99 6.7.8p14. We have an array of character type with unknown size 79 // being initialized to a string literal. 80 llvm::APSInt ConstVal(32); 81 ConstVal = StrLength; 82 // Return a new array type (C99 6.7.8p22). 83 DeclT = S.Context.getConstantArrayType(IAT->getElementType(), 84 ConstVal, 85 ArrayType::Normal, 0); 86 return; 87 } 88 89 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 90 91 // C99 6.7.8p14. We have an array of character type with known size. However, 92 // the size may be smaller or larger than the string we are initializing. 93 // FIXME: Avoid truncation for 64-bit length strings. 94 if (StrLength-1 > CAT->getSize().getZExtValue()) 95 S.Diag(Str->getSourceRange().getBegin(), 96 diag::warn_initializer_string_for_char_array_too_long) 97 << Str->getSourceRange(); 98 99 // Set the type to the actual size that we are initializing. If we have 100 // something like: 101 // char x[1] = "foo"; 102 // then this will set the string literal's type to char[1]. 103 Str->setType(DeclT); 104} 105 106//===----------------------------------------------------------------------===// 107// Semantic checking for initializer lists. 108//===----------------------------------------------------------------------===// 109 110/// @brief Semantic checking for initializer lists. 111/// 112/// The InitListChecker class contains a set of routines that each 113/// handle the initialization of a certain kind of entity, e.g., 114/// arrays, vectors, struct/union types, scalars, etc. The 115/// InitListChecker itself performs a recursive walk of the subobject 116/// structure of the type to be initialized, while stepping through 117/// the initializer list one element at a time. The IList and Index 118/// parameters to each of the Check* routines contain the active 119/// (syntactic) initializer list and the index into that initializer 120/// list that represents the current initializer. Each routine is 121/// responsible for moving that Index forward as it consumes elements. 122/// 123/// Each Check* routine also has a StructuredList/StructuredIndex 124/// arguments, which contains the current the "structured" (semantic) 125/// initializer list and the index into that initializer list where we 126/// are copying initializers as we map them over to the semantic 127/// list. Once we have completed our recursive walk of the subobject 128/// structure, we will have constructed a full semantic initializer 129/// list. 130/// 131/// C99 designators cause changes in the initializer list traversal, 132/// because they make the initialization "jump" into a specific 133/// subobject and then continue the initialization from that 134/// point. CheckDesignatedInitializer() recursively steps into the 135/// designated subobject and manages backing out the recursion to 136/// initialize the subobjects after the one designated. 137namespace { 138class InitListChecker { 139 Sema &SemaRef; 140 bool hadError; 141 std::map<InitListExpr *, InitListExpr *> SyntacticToSemantic; 142 InitListExpr *FullyStructuredList; 143 144 void CheckImplicitInitList(const InitializedEntity &Entity, 145 InitListExpr *ParentIList, QualType T, 146 unsigned &Index, InitListExpr *StructuredList, 147 unsigned &StructuredIndex, 148 bool TopLevelObject = false); 149 void CheckExplicitInitList(const InitializedEntity &Entity, 150 InitListExpr *IList, QualType &T, 151 unsigned &Index, InitListExpr *StructuredList, 152 unsigned &StructuredIndex, 153 bool TopLevelObject = false); 154 void CheckListElementTypes(const InitializedEntity &Entity, 155 InitListExpr *IList, QualType &DeclType, 156 bool SubobjectIsDesignatorContext, 157 unsigned &Index, 158 InitListExpr *StructuredList, 159 unsigned &StructuredIndex, 160 bool TopLevelObject = false); 161 void CheckSubElementType(const InitializedEntity &Entity, 162 InitListExpr *IList, QualType ElemType, 163 unsigned &Index, 164 InitListExpr *StructuredList, 165 unsigned &StructuredIndex); 166 void CheckScalarType(const InitializedEntity &Entity, 167 InitListExpr *IList, QualType DeclType, 168 unsigned &Index, 169 InitListExpr *StructuredList, 170 unsigned &StructuredIndex); 171 void CheckReferenceType(const InitializedEntity &Entity, 172 InitListExpr *IList, QualType DeclType, 173 unsigned &Index, 174 InitListExpr *StructuredList, 175 unsigned &StructuredIndex); 176 void CheckVectorType(const InitializedEntity &Entity, 177 InitListExpr *IList, QualType DeclType, unsigned &Index, 178 InitListExpr *StructuredList, 179 unsigned &StructuredIndex); 180 void CheckStructUnionTypes(const InitializedEntity &Entity, 181 InitListExpr *IList, QualType DeclType, 182 RecordDecl::field_iterator Field, 183 bool SubobjectIsDesignatorContext, unsigned &Index, 184 InitListExpr *StructuredList, 185 unsigned &StructuredIndex, 186 bool TopLevelObject = false); 187 void CheckArrayType(const InitializedEntity &Entity, 188 InitListExpr *IList, QualType &DeclType, 189 llvm::APSInt elementIndex, 190 bool SubobjectIsDesignatorContext, unsigned &Index, 191 InitListExpr *StructuredList, 192 unsigned &StructuredIndex); 193 bool CheckDesignatedInitializer(const InitializedEntity &Entity, 194 InitListExpr *IList, DesignatedInitExpr *DIE, 195 unsigned DesigIdx, 196 QualType &CurrentObjectType, 197 RecordDecl::field_iterator *NextField, 198 llvm::APSInt *NextElementIndex, 199 unsigned &Index, 200 InitListExpr *StructuredList, 201 unsigned &StructuredIndex, 202 bool FinishSubobjectInit, 203 bool TopLevelObject); 204 InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index, 205 QualType CurrentObjectType, 206 InitListExpr *StructuredList, 207 unsigned StructuredIndex, 208 SourceRange InitRange); 209 void UpdateStructuredListElement(InitListExpr *StructuredList, 210 unsigned &StructuredIndex, 211 Expr *expr); 212 int numArrayElements(QualType DeclType); 213 int numStructUnionElements(QualType DeclType); 214 215 void FillInValueInitForField(unsigned Init, FieldDecl *Field, 216 const InitializedEntity &ParentEntity, 217 InitListExpr *ILE, bool &RequiresSecondPass); 218 void FillInValueInitializations(const InitializedEntity &Entity, 219 InitListExpr *ILE, bool &RequiresSecondPass); 220public: 221 InitListChecker(Sema &S, const InitializedEntity &Entity, 222 InitListExpr *IL, QualType &T); 223 bool HadError() { return hadError; } 224 225 // @brief Retrieves the fully-structured initializer list used for 226 // semantic analysis and code generation. 227 InitListExpr *getFullyStructuredList() const { return FullyStructuredList; } 228}; 229} // end anonymous namespace 230 231void InitListChecker::FillInValueInitForField(unsigned Init, FieldDecl *Field, 232 const InitializedEntity &ParentEntity, 233 InitListExpr *ILE, 234 bool &RequiresSecondPass) { 235 SourceLocation Loc = ILE->getSourceRange().getBegin(); 236 unsigned NumInits = ILE->getNumInits(); 237 InitializedEntity MemberEntity 238 = InitializedEntity::InitializeMember(Field, &ParentEntity); 239 if (Init >= NumInits || !ILE->getInit(Init)) { 240 // FIXME: We probably don't need to handle references 241 // specially here, since value-initialization of references is 242 // handled in InitializationSequence. 243 if (Field->getType()->isReferenceType()) { 244 // C++ [dcl.init.aggr]p9: 245 // If an incomplete or empty initializer-list leaves a 246 // member of reference type uninitialized, the program is 247 // ill-formed. 248 SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized) 249 << Field->getType() 250 << ILE->getSyntacticForm()->getSourceRange(); 251 SemaRef.Diag(Field->getLocation(), 252 diag::note_uninit_reference_member); 253 hadError = true; 254 return; 255 } 256 257 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, 258 true); 259 InitializationSequence InitSeq(SemaRef, MemberEntity, Kind, 0, 0); 260 if (!InitSeq) { 261 InitSeq.Diagnose(SemaRef, MemberEntity, Kind, 0, 0); 262 hadError = true; 263 return; 264 } 265 266 Sema::OwningExprResult MemberInit 267 = InitSeq.Perform(SemaRef, MemberEntity, Kind, 268 Sema::MultiExprArg(SemaRef, 0, 0)); 269 if (MemberInit.isInvalid()) { 270 hadError = true; 271 return; 272 } 273 274 if (hadError) { 275 // Do nothing 276 } else if (Init < NumInits) { 277 ILE->setInit(Init, MemberInit.takeAs<Expr>()); 278 } else if (InitSeq.getKind() 279 == InitializationSequence::ConstructorInitialization) { 280 // Value-initialization requires a constructor call, so 281 // extend the initializer list to include the constructor 282 // call and make a note that we'll need to take another pass 283 // through the initializer list. 284 ILE->updateInit(SemaRef.Context, Init, MemberInit.takeAs<Expr>()); 285 RequiresSecondPass = true; 286 } 287 } else if (InitListExpr *InnerILE 288 = dyn_cast<InitListExpr>(ILE->getInit(Init))) 289 FillInValueInitializations(MemberEntity, InnerILE, 290 RequiresSecondPass); 291} 292 293/// Recursively replaces NULL values within the given initializer list 294/// with expressions that perform value-initialization of the 295/// appropriate type. 296void 297InitListChecker::FillInValueInitializations(const InitializedEntity &Entity, 298 InitListExpr *ILE, 299 bool &RequiresSecondPass) { 300 assert((ILE->getType() != SemaRef.Context.VoidTy) && 301 "Should not have void type"); 302 SourceLocation Loc = ILE->getSourceRange().getBegin(); 303 if (ILE->getSyntacticForm()) 304 Loc = ILE->getSyntacticForm()->getSourceRange().getBegin(); 305 306 if (const RecordType *RType = ILE->getType()->getAs<RecordType>()) { 307 if (RType->getDecl()->isUnion() && 308 ILE->getInitializedFieldInUnion()) 309 FillInValueInitForField(0, ILE->getInitializedFieldInUnion(), 310 Entity, ILE, RequiresSecondPass); 311 else { 312 unsigned Init = 0; 313 for (RecordDecl::field_iterator 314 Field = RType->getDecl()->field_begin(), 315 FieldEnd = RType->getDecl()->field_end(); 316 Field != FieldEnd; ++Field) { 317 if (Field->isUnnamedBitfield()) 318 continue; 319 320 if (hadError) 321 return; 322 323 FillInValueInitForField(Init, *Field, Entity, ILE, RequiresSecondPass); 324 if (hadError) 325 return; 326 327 ++Init; 328 329 // Only look at the first initialization of a union. 330 if (RType->getDecl()->isUnion()) 331 break; 332 } 333 } 334 335 return; 336 } 337 338 QualType ElementType; 339 340 InitializedEntity ElementEntity = Entity; 341 unsigned NumInits = ILE->getNumInits(); 342 unsigned NumElements = NumInits; 343 if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) { 344 ElementType = AType->getElementType(); 345 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) 346 NumElements = CAType->getSize().getZExtValue(); 347 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context, 348 0, Entity); 349 } else if (const VectorType *VType = ILE->getType()->getAs<VectorType>()) { 350 ElementType = VType->getElementType(); 351 NumElements = VType->getNumElements(); 352 ElementEntity = InitializedEntity::InitializeElement(SemaRef.Context, 353 0, Entity); 354 } else 355 ElementType = ILE->getType(); 356 357 358 for (unsigned Init = 0; Init != NumElements; ++Init) { 359 if (hadError) 360 return; 361 362 if (ElementEntity.getKind() == InitializedEntity::EK_ArrayElement || 363 ElementEntity.getKind() == InitializedEntity::EK_VectorElement) 364 ElementEntity.setElementIndex(Init); 365 366 if (Init >= NumInits || !ILE->getInit(Init)) { 367 InitializationKind Kind = InitializationKind::CreateValue(Loc, Loc, Loc, 368 true); 369 InitializationSequence InitSeq(SemaRef, ElementEntity, Kind, 0, 0); 370 if (!InitSeq) { 371 InitSeq.Diagnose(SemaRef, ElementEntity, Kind, 0, 0); 372 hadError = true; 373 return; 374 } 375 376 Sema::OwningExprResult ElementInit 377 = InitSeq.Perform(SemaRef, ElementEntity, Kind, 378 Sema::MultiExprArg(SemaRef, 0, 0)); 379 if (ElementInit.isInvalid()) { 380 hadError = true; 381 return; 382 } 383 384 if (hadError) { 385 // Do nothing 386 } else if (Init < NumInits) { 387 ILE->setInit(Init, ElementInit.takeAs<Expr>()); 388 } else if (InitSeq.getKind() 389 == InitializationSequence::ConstructorInitialization) { 390 // Value-initialization requires a constructor call, so 391 // extend the initializer list to include the constructor 392 // call and make a note that we'll need to take another pass 393 // through the initializer list. 394 ILE->updateInit(SemaRef.Context, Init, ElementInit.takeAs<Expr>()); 395 RequiresSecondPass = true; 396 } 397 } else if (InitListExpr *InnerILE 398 = dyn_cast<InitListExpr>(ILE->getInit(Init))) 399 FillInValueInitializations(ElementEntity, InnerILE, RequiresSecondPass); 400 } 401} 402 403 404InitListChecker::InitListChecker(Sema &S, const InitializedEntity &Entity, 405 InitListExpr *IL, QualType &T) 406 : SemaRef(S) { 407 hadError = false; 408 409 unsigned newIndex = 0; 410 unsigned newStructuredIndex = 0; 411 FullyStructuredList 412 = getStructuredSubobjectInit(IL, newIndex, T, 0, 0, IL->getSourceRange()); 413 CheckExplicitInitList(Entity, IL, T, newIndex, 414 FullyStructuredList, newStructuredIndex, 415 /*TopLevelObject=*/true); 416 417 if (!hadError) { 418 bool RequiresSecondPass = false; 419 FillInValueInitializations(Entity, FullyStructuredList, RequiresSecondPass); 420 if (RequiresSecondPass && !hadError) 421 FillInValueInitializations(Entity, FullyStructuredList, 422 RequiresSecondPass); 423 } 424} 425 426int InitListChecker::numArrayElements(QualType DeclType) { 427 // FIXME: use a proper constant 428 int maxElements = 0x7FFFFFFF; 429 if (const ConstantArrayType *CAT = 430 SemaRef.Context.getAsConstantArrayType(DeclType)) { 431 maxElements = static_cast<int>(CAT->getSize().getZExtValue()); 432 } 433 return maxElements; 434} 435 436int InitListChecker::numStructUnionElements(QualType DeclType) { 437 RecordDecl *structDecl = DeclType->getAs<RecordType>()->getDecl(); 438 int InitializableMembers = 0; 439 for (RecordDecl::field_iterator 440 Field = structDecl->field_begin(), 441 FieldEnd = structDecl->field_end(); 442 Field != FieldEnd; ++Field) { 443 if ((*Field)->getIdentifier() || !(*Field)->isBitField()) 444 ++InitializableMembers; 445 } 446 if (structDecl->isUnion()) 447 return std::min(InitializableMembers, 1); 448 return InitializableMembers - structDecl->hasFlexibleArrayMember(); 449} 450 451void InitListChecker::CheckImplicitInitList(const InitializedEntity &Entity, 452 InitListExpr *ParentIList, 453 QualType T, unsigned &Index, 454 InitListExpr *StructuredList, 455 unsigned &StructuredIndex, 456 bool TopLevelObject) { 457 int maxElements = 0; 458 459 if (T->isArrayType()) 460 maxElements = numArrayElements(T); 461 else if (T->isStructureType() || T->isUnionType()) 462 maxElements = numStructUnionElements(T); 463 else if (T->isVectorType()) 464 maxElements = T->getAs<VectorType>()->getNumElements(); 465 else 466 assert(0 && "CheckImplicitInitList(): Illegal type"); 467 468 if (maxElements == 0) { 469 SemaRef.Diag(ParentIList->getInit(Index)->getLocStart(), 470 diag::err_implicit_empty_initializer); 471 ++Index; 472 hadError = true; 473 return; 474 } 475 476 // Build a structured initializer list corresponding to this subobject. 477 InitListExpr *StructuredSubobjectInitList 478 = getStructuredSubobjectInit(ParentIList, Index, T, StructuredList, 479 StructuredIndex, 480 SourceRange(ParentIList->getInit(Index)->getSourceRange().getBegin(), 481 ParentIList->getSourceRange().getEnd())); 482 unsigned StructuredSubobjectInitIndex = 0; 483 484 // Check the element types and build the structural subobject. 485 unsigned StartIndex = Index; 486 CheckListElementTypes(Entity, ParentIList, T, 487 /*SubobjectIsDesignatorContext=*/false, Index, 488 StructuredSubobjectInitList, 489 StructuredSubobjectInitIndex, 490 TopLevelObject); 491 unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1); 492 StructuredSubobjectInitList->setType(T); 493 494 // Update the structured sub-object initializer so that it's ending 495 // range corresponds with the end of the last initializer it used. 496 if (EndIndex < ParentIList->getNumInits()) { 497 SourceLocation EndLoc 498 = ParentIList->getInit(EndIndex)->getSourceRange().getEnd(); 499 StructuredSubobjectInitList->setRBraceLoc(EndLoc); 500 } 501 502 // Warn about missing braces. 503 if (T->isArrayType() || T->isRecordType()) { 504 SemaRef.Diag(StructuredSubobjectInitList->getLocStart(), 505 diag::warn_missing_braces) 506 << StructuredSubobjectInitList->getSourceRange() 507 << FixItHint::CreateInsertion(StructuredSubobjectInitList->getLocStart(), 508 "{") 509 << FixItHint::CreateInsertion(SemaRef.PP.getLocForEndOfToken( 510 StructuredSubobjectInitList->getLocEnd()), 511 "}"); 512 } 513} 514 515void InitListChecker::CheckExplicitInitList(const InitializedEntity &Entity, 516 InitListExpr *IList, QualType &T, 517 unsigned &Index, 518 InitListExpr *StructuredList, 519 unsigned &StructuredIndex, 520 bool TopLevelObject) { 521 assert(IList->isExplicit() && "Illegal Implicit InitListExpr"); 522 SyntacticToSemantic[IList] = StructuredList; 523 StructuredList->setSyntacticForm(IList); 524 CheckListElementTypes(Entity, IList, T, /*SubobjectIsDesignatorContext=*/true, 525 Index, StructuredList, StructuredIndex, TopLevelObject); 526 IList->setType(T.getNonReferenceType()); 527 StructuredList->setType(T.getNonReferenceType()); 528 if (hadError) 529 return; 530 531 if (Index < IList->getNumInits()) { 532 // We have leftover initializers 533 if (StructuredIndex == 1 && 534 IsStringInit(StructuredList->getInit(0), T, SemaRef.Context)) { 535 unsigned DK = diag::warn_excess_initializers_in_char_array_initializer; 536 if (SemaRef.getLangOptions().CPlusPlus) { 537 DK = diag::err_excess_initializers_in_char_array_initializer; 538 hadError = true; 539 } 540 // Special-case 541 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK) 542 << IList->getInit(Index)->getSourceRange(); 543 } else if (!T->isIncompleteType()) { 544 // Don't complain for incomplete types, since we'll get an error 545 // elsewhere 546 QualType CurrentObjectType = StructuredList->getType(); 547 int initKind = 548 CurrentObjectType->isArrayType()? 0 : 549 CurrentObjectType->isVectorType()? 1 : 550 CurrentObjectType->isScalarType()? 2 : 551 CurrentObjectType->isUnionType()? 3 : 552 4; 553 554 unsigned DK = diag::warn_excess_initializers; 555 if (SemaRef.getLangOptions().CPlusPlus) { 556 DK = diag::err_excess_initializers; 557 hadError = true; 558 } 559 if (SemaRef.getLangOptions().OpenCL && initKind == 1) { 560 DK = diag::err_excess_initializers; 561 hadError = true; 562 } 563 564 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK) 565 << initKind << IList->getInit(Index)->getSourceRange(); 566 } 567 } 568 569 if (T->isScalarType() && !TopLevelObject) 570 SemaRef.Diag(IList->getLocStart(), diag::warn_braces_around_scalar_init) 571 << IList->getSourceRange() 572 << FixItHint::CreateRemoval(IList->getLocStart()) 573 << FixItHint::CreateRemoval(IList->getLocEnd()); 574} 575 576void InitListChecker::CheckListElementTypes(const InitializedEntity &Entity, 577 InitListExpr *IList, 578 QualType &DeclType, 579 bool SubobjectIsDesignatorContext, 580 unsigned &Index, 581 InitListExpr *StructuredList, 582 unsigned &StructuredIndex, 583 bool TopLevelObject) { 584 if (DeclType->isScalarType()) { 585 CheckScalarType(Entity, IList, DeclType, Index, 586 StructuredList, StructuredIndex); 587 } else if (DeclType->isVectorType()) { 588 CheckVectorType(Entity, IList, DeclType, Index, 589 StructuredList, StructuredIndex); 590 } else if (DeclType->isAggregateType()) { 591 if (DeclType->isRecordType()) { 592 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 593 CheckStructUnionTypes(Entity, IList, DeclType, RD->field_begin(), 594 SubobjectIsDesignatorContext, Index, 595 StructuredList, StructuredIndex, 596 TopLevelObject); 597 } else if (DeclType->isArrayType()) { 598 llvm::APSInt Zero( 599 SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()), 600 false); 601 CheckArrayType(Entity, IList, DeclType, Zero, 602 SubobjectIsDesignatorContext, Index, 603 StructuredList, StructuredIndex); 604 } else 605 assert(0 && "Aggregate that isn't a structure or array?!"); 606 } else if (DeclType->isVoidType() || DeclType->isFunctionType()) { 607 // This type is invalid, issue a diagnostic. 608 ++Index; 609 SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type) 610 << DeclType; 611 hadError = true; 612 } else if (DeclType->isRecordType()) { 613 // C++ [dcl.init]p14: 614 // [...] If the class is an aggregate (8.5.1), and the initializer 615 // is a brace-enclosed list, see 8.5.1. 616 // 617 // Note: 8.5.1 is handled below; here, we diagnose the case where 618 // we have an initializer list and a destination type that is not 619 // an aggregate. 620 // FIXME: In C++0x, this is yet another form of initialization. 621 SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list) 622 << DeclType << IList->getSourceRange(); 623 hadError = true; 624 } else if (DeclType->isReferenceType()) { 625 CheckReferenceType(Entity, IList, DeclType, Index, 626 StructuredList, StructuredIndex); 627 } else { 628 // In C, all types are either scalars or aggregates, but 629 // additional handling is needed here for C++ (and possibly others?). 630 assert(0 && "Unsupported initializer type"); 631 } 632} 633 634void InitListChecker::CheckSubElementType(const InitializedEntity &Entity, 635 InitListExpr *IList, 636 QualType ElemType, 637 unsigned &Index, 638 InitListExpr *StructuredList, 639 unsigned &StructuredIndex) { 640 Expr *expr = IList->getInit(Index); 641 if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) { 642 unsigned newIndex = 0; 643 unsigned newStructuredIndex = 0; 644 InitListExpr *newStructuredList 645 = getStructuredSubobjectInit(IList, Index, ElemType, 646 StructuredList, StructuredIndex, 647 SubInitList->getSourceRange()); 648 CheckExplicitInitList(Entity, SubInitList, ElemType, newIndex, 649 newStructuredList, newStructuredIndex); 650 ++StructuredIndex; 651 ++Index; 652 } else if (Expr *Str = IsStringInit(expr, ElemType, SemaRef.Context)) { 653 CheckStringInit(Str, ElemType, SemaRef); 654 UpdateStructuredListElement(StructuredList, StructuredIndex, Str); 655 ++Index; 656 } else if (ElemType->isScalarType()) { 657 CheckScalarType(Entity, IList, ElemType, Index, 658 StructuredList, StructuredIndex); 659 } else if (ElemType->isReferenceType()) { 660 CheckReferenceType(Entity, IList, ElemType, Index, 661 StructuredList, StructuredIndex); 662 } else { 663 if (SemaRef.getLangOptions().CPlusPlus) { 664 // C++ [dcl.init.aggr]p12: 665 // All implicit type conversions (clause 4) are considered when 666 // initializing the aggregate member with an ini- tializer from 667 // an initializer-list. If the initializer can initialize a 668 // member, the member is initialized. [...] 669 670 // FIXME: Better EqualLoc? 671 InitializationKind Kind = 672 InitializationKind::CreateCopy(expr->getLocStart(), SourceLocation()); 673 InitializationSequence Seq(SemaRef, Entity, Kind, &expr, 1); 674 675 if (Seq) { 676 Sema::OwningExprResult Result = 677 Seq.Perform(SemaRef, Entity, Kind, 678 Sema::MultiExprArg(SemaRef, (void **)&expr, 1)); 679 if (Result.isInvalid()) 680 hadError = true; 681 682 UpdateStructuredListElement(StructuredList, StructuredIndex, 683 Result.takeAs<Expr>()); 684 ++Index; 685 return; 686 } 687 688 // Fall through for subaggregate initialization 689 } else { 690 // C99 6.7.8p13: 691 // 692 // The initializer for a structure or union object that has 693 // automatic storage duration shall be either an initializer 694 // list as described below, or a single expression that has 695 // compatible structure or union type. In the latter case, the 696 // initial value of the object, including unnamed members, is 697 // that of the expression. 698 if ((ElemType->isRecordType() || ElemType->isVectorType()) && 699 SemaRef.Context.hasSameUnqualifiedType(expr->getType(), ElemType)) { 700 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 701 ++Index; 702 return; 703 } 704 705 // Fall through for subaggregate initialization 706 } 707 708 // C++ [dcl.init.aggr]p12: 709 // 710 // [...] Otherwise, if the member is itself a non-empty 711 // subaggregate, brace elision is assumed and the initializer is 712 // considered for the initialization of the first member of 713 // the subaggregate. 714 if (ElemType->isAggregateType() || ElemType->isVectorType()) { 715 CheckImplicitInitList(Entity, IList, ElemType, Index, StructuredList, 716 StructuredIndex); 717 ++StructuredIndex; 718 } else { 719 // We cannot initialize this element, so let 720 // PerformCopyInitialization produce the appropriate diagnostic. 721 SemaRef.PerformCopyInitialization(Entity, SourceLocation(), 722 SemaRef.Owned(expr)); 723 IList->setInit(Index, 0); 724 hadError = true; 725 ++Index; 726 ++StructuredIndex; 727 } 728 } 729} 730 731void InitListChecker::CheckScalarType(const InitializedEntity &Entity, 732 InitListExpr *IList, QualType DeclType, 733 unsigned &Index, 734 InitListExpr *StructuredList, 735 unsigned &StructuredIndex) { 736 if (Index < IList->getNumInits()) { 737 Expr *expr = IList->getInit(Index); 738 if (isa<InitListExpr>(expr)) { 739 SemaRef.Diag(IList->getLocStart(), 740 diag::err_many_braces_around_scalar_init) 741 << IList->getSourceRange(); 742 hadError = true; 743 ++Index; 744 ++StructuredIndex; 745 return; 746 } else if (isa<DesignatedInitExpr>(expr)) { 747 SemaRef.Diag(expr->getSourceRange().getBegin(), 748 diag::err_designator_for_scalar_init) 749 << DeclType << expr->getSourceRange(); 750 hadError = true; 751 ++Index; 752 ++StructuredIndex; 753 return; 754 } 755 756 Sema::OwningExprResult Result = 757 SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), 758 SemaRef.Owned(expr)); 759 760 Expr *ResultExpr = 0; 761 762 if (Result.isInvalid()) 763 hadError = true; // types weren't compatible. 764 else { 765 ResultExpr = Result.takeAs<Expr>(); 766 767 if (ResultExpr != expr) { 768 // The type was promoted, update initializer list. 769 IList->setInit(Index, ResultExpr); 770 } 771 } 772 if (hadError) 773 ++StructuredIndex; 774 else 775 UpdateStructuredListElement(StructuredList, StructuredIndex, ResultExpr); 776 ++Index; 777 } else { 778 SemaRef.Diag(IList->getLocStart(), diag::err_empty_scalar_initializer) 779 << IList->getSourceRange(); 780 hadError = true; 781 ++Index; 782 ++StructuredIndex; 783 return; 784 } 785} 786 787void InitListChecker::CheckReferenceType(const InitializedEntity &Entity, 788 InitListExpr *IList, QualType DeclType, 789 unsigned &Index, 790 InitListExpr *StructuredList, 791 unsigned &StructuredIndex) { 792 if (Index < IList->getNumInits()) { 793 Expr *expr = IList->getInit(Index); 794 if (isa<InitListExpr>(expr)) { 795 SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list) 796 << DeclType << IList->getSourceRange(); 797 hadError = true; 798 ++Index; 799 ++StructuredIndex; 800 return; 801 } 802 803 Sema::OwningExprResult Result = 804 SemaRef.PerformCopyInitialization(Entity, expr->getLocStart(), 805 SemaRef.Owned(expr)); 806 807 if (Result.isInvalid()) 808 hadError = true; 809 810 expr = Result.takeAs<Expr>(); 811 IList->setInit(Index, expr); 812 813 if (hadError) 814 ++StructuredIndex; 815 else 816 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 817 ++Index; 818 } else { 819 // FIXME: It would be wonderful if we could point at the actual member. In 820 // general, it would be useful to pass location information down the stack, 821 // so that we know the location (or decl) of the "current object" being 822 // initialized. 823 SemaRef.Diag(IList->getLocStart(), 824 diag::err_init_reference_member_uninitialized) 825 << DeclType 826 << IList->getSourceRange(); 827 hadError = true; 828 ++Index; 829 ++StructuredIndex; 830 return; 831 } 832} 833 834void InitListChecker::CheckVectorType(const InitializedEntity &Entity, 835 InitListExpr *IList, QualType DeclType, 836 unsigned &Index, 837 InitListExpr *StructuredList, 838 unsigned &StructuredIndex) { 839 if (Index < IList->getNumInits()) { 840 const VectorType *VT = DeclType->getAs<VectorType>(); 841 unsigned maxElements = VT->getNumElements(); 842 unsigned numEltsInit = 0; 843 QualType elementType = VT->getElementType(); 844 845 if (!SemaRef.getLangOptions().OpenCL) { 846 InitializedEntity ElementEntity = 847 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 848 849 for (unsigned i = 0; i < maxElements; ++i, ++numEltsInit) { 850 // Don't attempt to go past the end of the init list 851 if (Index >= IList->getNumInits()) 852 break; 853 854 ElementEntity.setElementIndex(Index); 855 CheckSubElementType(ElementEntity, IList, elementType, Index, 856 StructuredList, StructuredIndex); 857 } 858 } else { 859 InitializedEntity ElementEntity = 860 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 861 862 // OpenCL initializers allows vectors to be constructed from vectors. 863 for (unsigned i = 0; i < maxElements; ++i) { 864 // Don't attempt to go past the end of the init list 865 if (Index >= IList->getNumInits()) 866 break; 867 868 ElementEntity.setElementIndex(Index); 869 870 QualType IType = IList->getInit(Index)->getType(); 871 if (!IType->isVectorType()) { 872 CheckSubElementType(ElementEntity, IList, elementType, Index, 873 StructuredList, StructuredIndex); 874 ++numEltsInit; 875 } else { 876 const VectorType *IVT = IType->getAs<VectorType>(); 877 unsigned numIElts = IVT->getNumElements(); 878 QualType VecType = SemaRef.Context.getExtVectorType(elementType, 879 numIElts); 880 CheckSubElementType(ElementEntity, IList, VecType, Index, 881 StructuredList, StructuredIndex); 882 numEltsInit += numIElts; 883 } 884 } 885 } 886 887 // OpenCL & AltiVec require all elements to be initialized. 888 if (numEltsInit != maxElements) 889 if (SemaRef.getLangOptions().OpenCL || SemaRef.getLangOptions().AltiVec) 890 SemaRef.Diag(IList->getSourceRange().getBegin(), 891 diag::err_vector_incorrect_num_initializers) 892 << (numEltsInit < maxElements) << maxElements << numEltsInit; 893 } 894} 895 896void InitListChecker::CheckArrayType(const InitializedEntity &Entity, 897 InitListExpr *IList, QualType &DeclType, 898 llvm::APSInt elementIndex, 899 bool SubobjectIsDesignatorContext, 900 unsigned &Index, 901 InitListExpr *StructuredList, 902 unsigned &StructuredIndex) { 903 // Check for the special-case of initializing an array with a string. 904 if (Index < IList->getNumInits()) { 905 if (Expr *Str = IsStringInit(IList->getInit(Index), DeclType, 906 SemaRef.Context)) { 907 CheckStringInit(Str, DeclType, SemaRef); 908 // We place the string literal directly into the resulting 909 // initializer list. This is the only place where the structure 910 // of the structured initializer list doesn't match exactly, 911 // because doing so would involve allocating one character 912 // constant for each string. 913 UpdateStructuredListElement(StructuredList, StructuredIndex, Str); 914 StructuredList->resizeInits(SemaRef.Context, StructuredIndex); 915 ++Index; 916 return; 917 } 918 } 919 if (const VariableArrayType *VAT = 920 SemaRef.Context.getAsVariableArrayType(DeclType)) { 921 // Check for VLAs; in standard C it would be possible to check this 922 // earlier, but I don't know where clang accepts VLAs (gcc accepts 923 // them in all sorts of strange places). 924 SemaRef.Diag(VAT->getSizeExpr()->getLocStart(), 925 diag::err_variable_object_no_init) 926 << VAT->getSizeExpr()->getSourceRange(); 927 hadError = true; 928 ++Index; 929 ++StructuredIndex; 930 return; 931 } 932 933 // We might know the maximum number of elements in advance. 934 llvm::APSInt maxElements(elementIndex.getBitWidth(), 935 elementIndex.isUnsigned()); 936 bool maxElementsKnown = false; 937 if (const ConstantArrayType *CAT = 938 SemaRef.Context.getAsConstantArrayType(DeclType)) { 939 maxElements = CAT->getSize(); 940 elementIndex.extOrTrunc(maxElements.getBitWidth()); 941 elementIndex.setIsUnsigned(maxElements.isUnsigned()); 942 maxElementsKnown = true; 943 } 944 945 QualType elementType = SemaRef.Context.getAsArrayType(DeclType) 946 ->getElementType(); 947 while (Index < IList->getNumInits()) { 948 Expr *Init = IList->getInit(Index); 949 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) { 950 // If we're not the subobject that matches up with the '{' for 951 // the designator, we shouldn't be handling the 952 // designator. Return immediately. 953 if (!SubobjectIsDesignatorContext) 954 return; 955 956 // Handle this designated initializer. elementIndex will be 957 // updated to be the next array element we'll initialize. 958 if (CheckDesignatedInitializer(Entity, IList, DIE, 0, 959 DeclType, 0, &elementIndex, Index, 960 StructuredList, StructuredIndex, true, 961 false)) { 962 hadError = true; 963 continue; 964 } 965 966 if (elementIndex.getBitWidth() > maxElements.getBitWidth()) 967 maxElements.extend(elementIndex.getBitWidth()); 968 else if (elementIndex.getBitWidth() < maxElements.getBitWidth()) 969 elementIndex.extend(maxElements.getBitWidth()); 970 elementIndex.setIsUnsigned(maxElements.isUnsigned()); 971 972 // If the array is of incomplete type, keep track of the number of 973 // elements in the initializer. 974 if (!maxElementsKnown && elementIndex > maxElements) 975 maxElements = elementIndex; 976 977 continue; 978 } 979 980 // If we know the maximum number of elements, and we've already 981 // hit it, stop consuming elements in the initializer list. 982 if (maxElementsKnown && elementIndex == maxElements) 983 break; 984 985 InitializedEntity ElementEntity = 986 InitializedEntity::InitializeElement(SemaRef.Context, StructuredIndex, 987 Entity); 988 // Check this element. 989 CheckSubElementType(ElementEntity, IList, elementType, Index, 990 StructuredList, StructuredIndex); 991 ++elementIndex; 992 993 // If the array is of incomplete type, keep track of the number of 994 // elements in the initializer. 995 if (!maxElementsKnown && elementIndex > maxElements) 996 maxElements = elementIndex; 997 } 998 if (!hadError && DeclType->isIncompleteArrayType()) { 999 // If this is an incomplete array type, the actual type needs to 1000 // be calculated here. 1001 llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned()); 1002 if (maxElements == Zero) { 1003 // Sizing an array implicitly to zero is not allowed by ISO C, 1004 // but is supported by GNU. 1005 SemaRef.Diag(IList->getLocStart(), 1006 diag::ext_typecheck_zero_array_size); 1007 } 1008 1009 DeclType = SemaRef.Context.getConstantArrayType(elementType, maxElements, 1010 ArrayType::Normal, 0); 1011 } 1012} 1013 1014void InitListChecker::CheckStructUnionTypes(const InitializedEntity &Entity, 1015 InitListExpr *IList, 1016 QualType DeclType, 1017 RecordDecl::field_iterator Field, 1018 bool SubobjectIsDesignatorContext, 1019 unsigned &Index, 1020 InitListExpr *StructuredList, 1021 unsigned &StructuredIndex, 1022 bool TopLevelObject) { 1023 RecordDecl* structDecl = DeclType->getAs<RecordType>()->getDecl(); 1024 1025 // If the record is invalid, some of it's members are invalid. To avoid 1026 // confusion, we forgo checking the intializer for the entire record. 1027 if (structDecl->isInvalidDecl()) { 1028 hadError = true; 1029 return; 1030 } 1031 1032 if (DeclType->isUnionType() && IList->getNumInits() == 0) { 1033 // Value-initialize the first named member of the union. 1034 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 1035 for (RecordDecl::field_iterator FieldEnd = RD->field_end(); 1036 Field != FieldEnd; ++Field) { 1037 if (Field->getDeclName()) { 1038 StructuredList->setInitializedFieldInUnion(*Field); 1039 break; 1040 } 1041 } 1042 return; 1043 } 1044 1045 // If structDecl is a forward declaration, this loop won't do 1046 // anything except look at designated initializers; That's okay, 1047 // because an error should get printed out elsewhere. It might be 1048 // worthwhile to skip over the rest of the initializer, though. 1049 RecordDecl *RD = DeclType->getAs<RecordType>()->getDecl(); 1050 RecordDecl::field_iterator FieldEnd = RD->field_end(); 1051 bool InitializedSomething = false; 1052 bool CheckForMissingFields = true; 1053 while (Index < IList->getNumInits()) { 1054 Expr *Init = IList->getInit(Index); 1055 1056 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) { 1057 // If we're not the subobject that matches up with the '{' for 1058 // the designator, we shouldn't be handling the 1059 // designator. Return immediately. 1060 if (!SubobjectIsDesignatorContext) 1061 return; 1062 1063 // Handle this designated initializer. Field will be updated to 1064 // the next field that we'll be initializing. 1065 if (CheckDesignatedInitializer(Entity, IList, DIE, 0, 1066 DeclType, &Field, 0, Index, 1067 StructuredList, StructuredIndex, 1068 true, TopLevelObject)) 1069 hadError = true; 1070 1071 InitializedSomething = true; 1072 1073 // Disable check for missing fields when designators are used. 1074 // This matches gcc behaviour. 1075 CheckForMissingFields = false; 1076 continue; 1077 } 1078 1079 if (Field == FieldEnd) { 1080 // We've run out of fields. We're done. 1081 break; 1082 } 1083 1084 // We've already initialized a member of a union. We're done. 1085 if (InitializedSomething && DeclType->isUnionType()) 1086 break; 1087 1088 // If we've hit the flexible array member at the end, we're done. 1089 if (Field->getType()->isIncompleteArrayType()) 1090 break; 1091 1092 if (Field->isUnnamedBitfield()) { 1093 // Don't initialize unnamed bitfields, e.g. "int : 20;" 1094 ++Field; 1095 continue; 1096 } 1097 1098 InitializedEntity MemberEntity = 1099 InitializedEntity::InitializeMember(*Field, &Entity); 1100 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1101 StructuredList, StructuredIndex); 1102 InitializedSomething = true; 1103 1104 if (DeclType->isUnionType()) { 1105 // Initialize the first field within the union. 1106 StructuredList->setInitializedFieldInUnion(*Field); 1107 } 1108 1109 ++Field; 1110 } 1111 1112 // Emit warnings for missing struct field initializers. 1113 if (CheckForMissingFields && Field != FieldEnd && 1114 !Field->getType()->isIncompleteArrayType() && !DeclType->isUnionType()) { 1115 // It is possible we have one or more unnamed bitfields remaining. 1116 // Find first (if any) named field and emit warning. 1117 for (RecordDecl::field_iterator it = Field, end = RD->field_end(); 1118 it != end; ++it) { 1119 if (!it->isUnnamedBitfield()) { 1120 SemaRef.Diag(IList->getSourceRange().getEnd(), 1121 diag::warn_missing_field_initializers) << it->getName(); 1122 break; 1123 } 1124 } 1125 } 1126 1127 if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() || 1128 Index >= IList->getNumInits()) 1129 return; 1130 1131 // Handle GNU flexible array initializers. 1132 if (!TopLevelObject && 1133 (!isa<InitListExpr>(IList->getInit(Index)) || 1134 cast<InitListExpr>(IList->getInit(Index))->getNumInits() > 0)) { 1135 SemaRef.Diag(IList->getInit(Index)->getSourceRange().getBegin(), 1136 diag::err_flexible_array_init_nonempty) 1137 << IList->getInit(Index)->getSourceRange().getBegin(); 1138 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1139 << *Field; 1140 hadError = true; 1141 ++Index; 1142 return; 1143 } else { 1144 SemaRef.Diag(IList->getInit(Index)->getSourceRange().getBegin(), 1145 diag::ext_flexible_array_init) 1146 << IList->getInit(Index)->getSourceRange().getBegin(); 1147 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1148 << *Field; 1149 } 1150 1151 InitializedEntity MemberEntity = 1152 InitializedEntity::InitializeMember(*Field, &Entity); 1153 1154 if (isa<InitListExpr>(IList->getInit(Index))) 1155 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1156 StructuredList, StructuredIndex); 1157 else 1158 CheckImplicitInitList(MemberEntity, IList, Field->getType(), Index, 1159 StructuredList, StructuredIndex); 1160} 1161 1162/// \brief Expand a field designator that refers to a member of an 1163/// anonymous struct or union into a series of field designators that 1164/// refers to the field within the appropriate subobject. 1165/// 1166/// Field/FieldIndex will be updated to point to the (new) 1167/// currently-designated field. 1168static void ExpandAnonymousFieldDesignator(Sema &SemaRef, 1169 DesignatedInitExpr *DIE, 1170 unsigned DesigIdx, 1171 FieldDecl *Field, 1172 RecordDecl::field_iterator &FieldIter, 1173 unsigned &FieldIndex) { 1174 typedef DesignatedInitExpr::Designator Designator; 1175 1176 // Build the path from the current object to the member of the 1177 // anonymous struct/union (backwards). 1178 llvm::SmallVector<FieldDecl *, 4> Path; 1179 SemaRef.BuildAnonymousStructUnionMemberPath(Field, Path); 1180 1181 // Build the replacement designators. 1182 llvm::SmallVector<Designator, 4> Replacements; 1183 for (llvm::SmallVector<FieldDecl *, 4>::reverse_iterator 1184 FI = Path.rbegin(), FIEnd = Path.rend(); 1185 FI != FIEnd; ++FI) { 1186 if (FI + 1 == FIEnd) 1187 Replacements.push_back(Designator((IdentifierInfo *)0, 1188 DIE->getDesignator(DesigIdx)->getDotLoc(), 1189 DIE->getDesignator(DesigIdx)->getFieldLoc())); 1190 else 1191 Replacements.push_back(Designator((IdentifierInfo *)0, SourceLocation(), 1192 SourceLocation())); 1193 Replacements.back().setField(*FI); 1194 } 1195 1196 // Expand the current designator into the set of replacement 1197 // designators, so we have a full subobject path down to where the 1198 // member of the anonymous struct/union is actually stored. 1199 DIE->ExpandDesignator(SemaRef.Context, DesigIdx, &Replacements[0], 1200 &Replacements[0] + Replacements.size()); 1201 1202 // Update FieldIter/FieldIndex; 1203 RecordDecl *Record = cast<RecordDecl>(Path.back()->getDeclContext()); 1204 FieldIter = Record->field_begin(); 1205 FieldIndex = 0; 1206 for (RecordDecl::field_iterator FEnd = Record->field_end(); 1207 FieldIter != FEnd; ++FieldIter) { 1208 if (FieldIter->isUnnamedBitfield()) 1209 continue; 1210 1211 if (*FieldIter == Path.back()) 1212 return; 1213 1214 ++FieldIndex; 1215 } 1216 1217 assert(false && "Unable to find anonymous struct/union field"); 1218} 1219 1220/// @brief Check the well-formedness of a C99 designated initializer. 1221/// 1222/// Determines whether the designated initializer @p DIE, which 1223/// resides at the given @p Index within the initializer list @p 1224/// IList, is well-formed for a current object of type @p DeclType 1225/// (C99 6.7.8). The actual subobject that this designator refers to 1226/// within the current subobject is returned in either 1227/// @p NextField or @p NextElementIndex (whichever is appropriate). 1228/// 1229/// @param IList The initializer list in which this designated 1230/// initializer occurs. 1231/// 1232/// @param DIE The designated initializer expression. 1233/// 1234/// @param DesigIdx The index of the current designator. 1235/// 1236/// @param DeclType The type of the "current object" (C99 6.7.8p17), 1237/// into which the designation in @p DIE should refer. 1238/// 1239/// @param NextField If non-NULL and the first designator in @p DIE is 1240/// a field, this will be set to the field declaration corresponding 1241/// to the field named by the designator. 1242/// 1243/// @param NextElementIndex If non-NULL and the first designator in @p 1244/// DIE is an array designator or GNU array-range designator, this 1245/// will be set to the last index initialized by this designator. 1246/// 1247/// @param Index Index into @p IList where the designated initializer 1248/// @p DIE occurs. 1249/// 1250/// @param StructuredList The initializer list expression that 1251/// describes all of the subobject initializers in the order they'll 1252/// actually be initialized. 1253/// 1254/// @returns true if there was an error, false otherwise. 1255bool 1256InitListChecker::CheckDesignatedInitializer(const InitializedEntity &Entity, 1257 InitListExpr *IList, 1258 DesignatedInitExpr *DIE, 1259 unsigned DesigIdx, 1260 QualType &CurrentObjectType, 1261 RecordDecl::field_iterator *NextField, 1262 llvm::APSInt *NextElementIndex, 1263 unsigned &Index, 1264 InitListExpr *StructuredList, 1265 unsigned &StructuredIndex, 1266 bool FinishSubobjectInit, 1267 bool TopLevelObject) { 1268 if (DesigIdx == DIE->size()) { 1269 // Check the actual initialization for the designated object type. 1270 bool prevHadError = hadError; 1271 1272 // Temporarily remove the designator expression from the 1273 // initializer list that the child calls see, so that we don't try 1274 // to re-process the designator. 1275 unsigned OldIndex = Index; 1276 IList->setInit(OldIndex, DIE->getInit()); 1277 1278 CheckSubElementType(Entity, IList, CurrentObjectType, Index, 1279 StructuredList, StructuredIndex); 1280 1281 // Restore the designated initializer expression in the syntactic 1282 // form of the initializer list. 1283 if (IList->getInit(OldIndex) != DIE->getInit()) 1284 DIE->setInit(IList->getInit(OldIndex)); 1285 IList->setInit(OldIndex, DIE); 1286 1287 return hadError && !prevHadError; 1288 } 1289 1290 bool IsFirstDesignator = (DesigIdx == 0); 1291 assert((IsFirstDesignator || StructuredList) && 1292 "Need a non-designated initializer list to start from"); 1293 1294 DesignatedInitExpr::Designator *D = DIE->getDesignator(DesigIdx); 1295 // Determine the structural initializer list that corresponds to the 1296 // current subobject. 1297 StructuredList = IsFirstDesignator? SyntacticToSemantic[IList] 1298 : getStructuredSubobjectInit(IList, Index, CurrentObjectType, 1299 StructuredList, StructuredIndex, 1300 SourceRange(D->getStartLocation(), 1301 DIE->getSourceRange().getEnd())); 1302 assert(StructuredList && "Expected a structured initializer list"); 1303 1304 if (D->isFieldDesignator()) { 1305 // C99 6.7.8p7: 1306 // 1307 // If a designator has the form 1308 // 1309 // . identifier 1310 // 1311 // then the current object (defined below) shall have 1312 // structure or union type and the identifier shall be the 1313 // name of a member of that type. 1314 const RecordType *RT = CurrentObjectType->getAs<RecordType>(); 1315 if (!RT) { 1316 SourceLocation Loc = D->getDotLoc(); 1317 if (Loc.isInvalid()) 1318 Loc = D->getFieldLoc(); 1319 SemaRef.Diag(Loc, diag::err_field_designator_non_aggr) 1320 << SemaRef.getLangOptions().CPlusPlus << CurrentObjectType; 1321 ++Index; 1322 return true; 1323 } 1324 1325 // Note: we perform a linear search of the fields here, despite 1326 // the fact that we have a faster lookup method, because we always 1327 // need to compute the field's index. 1328 FieldDecl *KnownField = D->getField(); 1329 IdentifierInfo *FieldName = D->getFieldName(); 1330 unsigned FieldIndex = 0; 1331 RecordDecl::field_iterator 1332 Field = RT->getDecl()->field_begin(), 1333 FieldEnd = RT->getDecl()->field_end(); 1334 for (; Field != FieldEnd; ++Field) { 1335 if (Field->isUnnamedBitfield()) 1336 continue; 1337 1338 if (KnownField == *Field || Field->getIdentifier() == FieldName) 1339 break; 1340 1341 ++FieldIndex; 1342 } 1343 1344 if (Field == FieldEnd) { 1345 // There was no normal field in the struct with the designated 1346 // name. Perform another lookup for this name, which may find 1347 // something that we can't designate (e.g., a member function), 1348 // may find nothing, or may find a member of an anonymous 1349 // struct/union. 1350 DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName); 1351 FieldDecl *ReplacementField = 0; 1352 if (Lookup.first == Lookup.second) { 1353 // Name lookup didn't find anything. Determine whether this 1354 // was a typo for another field name. 1355 LookupResult R(SemaRef, FieldName, D->getFieldLoc(), 1356 Sema::LookupMemberName); 1357 if (SemaRef.CorrectTypo(R, /*Scope=*/0, /*SS=*/0, RT->getDecl(), false, 1358 Sema::CTC_NoKeywords) && 1359 (ReplacementField = R.getAsSingle<FieldDecl>()) && 1360 ReplacementField->getDeclContext()->getLookupContext() 1361 ->Equals(RT->getDecl())) { 1362 SemaRef.Diag(D->getFieldLoc(), 1363 diag::err_field_designator_unknown_suggest) 1364 << FieldName << CurrentObjectType << R.getLookupName() 1365 << FixItHint::CreateReplacement(D->getFieldLoc(), 1366 R.getLookupName().getAsString()); 1367 SemaRef.Diag(ReplacementField->getLocation(), 1368 diag::note_previous_decl) 1369 << ReplacementField->getDeclName(); 1370 } else { 1371 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown) 1372 << FieldName << CurrentObjectType; 1373 ++Index; 1374 return true; 1375 } 1376 } else if (!KnownField) { 1377 // Determine whether we found a field at all. 1378 ReplacementField = dyn_cast<FieldDecl>(*Lookup.first); 1379 } 1380 1381 if (!ReplacementField) { 1382 // Name lookup found something, but it wasn't a field. 1383 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield) 1384 << FieldName; 1385 SemaRef.Diag((*Lookup.first)->getLocation(), 1386 diag::note_field_designator_found); 1387 ++Index; 1388 return true; 1389 } 1390 1391 if (!KnownField && 1392 cast<RecordDecl>((ReplacementField)->getDeclContext()) 1393 ->isAnonymousStructOrUnion()) { 1394 // Handle an field designator that refers to a member of an 1395 // anonymous struct or union. 1396 ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, 1397 ReplacementField, 1398 Field, FieldIndex); 1399 D = DIE->getDesignator(DesigIdx); 1400 } else if (!KnownField) { 1401 // The replacement field comes from typo correction; find it 1402 // in the list of fields. 1403 FieldIndex = 0; 1404 Field = RT->getDecl()->field_begin(); 1405 for (; Field != FieldEnd; ++Field) { 1406 if (Field->isUnnamedBitfield()) 1407 continue; 1408 1409 if (ReplacementField == *Field || 1410 Field->getIdentifier() == ReplacementField->getIdentifier()) 1411 break; 1412 1413 ++FieldIndex; 1414 } 1415 } 1416 } else if (!KnownField && 1417 cast<RecordDecl>((*Field)->getDeclContext()) 1418 ->isAnonymousStructOrUnion()) { 1419 ExpandAnonymousFieldDesignator(SemaRef, DIE, DesigIdx, *Field, 1420 Field, FieldIndex); 1421 D = DIE->getDesignator(DesigIdx); 1422 } 1423 1424 // All of the fields of a union are located at the same place in 1425 // the initializer list. 1426 if (RT->getDecl()->isUnion()) { 1427 FieldIndex = 0; 1428 StructuredList->setInitializedFieldInUnion(*Field); 1429 } 1430 1431 // Update the designator with the field declaration. 1432 D->setField(*Field); 1433 1434 // Make sure that our non-designated initializer list has space 1435 // for a subobject corresponding to this field. 1436 if (FieldIndex >= StructuredList->getNumInits()) 1437 StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1); 1438 1439 // This designator names a flexible array member. 1440 if (Field->getType()->isIncompleteArrayType()) { 1441 bool Invalid = false; 1442 if ((DesigIdx + 1) != DIE->size()) { 1443 // We can't designate an object within the flexible array 1444 // member (because GCC doesn't allow it). 1445 DesignatedInitExpr::Designator *NextD 1446 = DIE->getDesignator(DesigIdx + 1); 1447 SemaRef.Diag(NextD->getStartLocation(), 1448 diag::err_designator_into_flexible_array_member) 1449 << SourceRange(NextD->getStartLocation(), 1450 DIE->getSourceRange().getEnd()); 1451 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1452 << *Field; 1453 Invalid = true; 1454 } 1455 1456 if (!hadError && !isa<InitListExpr>(DIE->getInit())) { 1457 // The initializer is not an initializer list. 1458 SemaRef.Diag(DIE->getInit()->getSourceRange().getBegin(), 1459 diag::err_flexible_array_init_needs_braces) 1460 << DIE->getInit()->getSourceRange(); 1461 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1462 << *Field; 1463 Invalid = true; 1464 } 1465 1466 // Handle GNU flexible array initializers. 1467 if (!Invalid && !TopLevelObject && 1468 cast<InitListExpr>(DIE->getInit())->getNumInits() > 0) { 1469 SemaRef.Diag(DIE->getSourceRange().getBegin(), 1470 diag::err_flexible_array_init_nonempty) 1471 << DIE->getSourceRange().getBegin(); 1472 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1473 << *Field; 1474 Invalid = true; 1475 } 1476 1477 if (Invalid) { 1478 ++Index; 1479 return true; 1480 } 1481 1482 // Initialize the array. 1483 bool prevHadError = hadError; 1484 unsigned newStructuredIndex = FieldIndex; 1485 unsigned OldIndex = Index; 1486 IList->setInit(Index, DIE->getInit()); 1487 1488 InitializedEntity MemberEntity = 1489 InitializedEntity::InitializeMember(*Field, &Entity); 1490 CheckSubElementType(MemberEntity, IList, Field->getType(), Index, 1491 StructuredList, newStructuredIndex); 1492 1493 IList->setInit(OldIndex, DIE); 1494 if (hadError && !prevHadError) { 1495 ++Field; 1496 ++FieldIndex; 1497 if (NextField) 1498 *NextField = Field; 1499 StructuredIndex = FieldIndex; 1500 return true; 1501 } 1502 } else { 1503 // Recurse to check later designated subobjects. 1504 QualType FieldType = (*Field)->getType(); 1505 unsigned newStructuredIndex = FieldIndex; 1506 1507 InitializedEntity MemberEntity = 1508 InitializedEntity::InitializeMember(*Field, &Entity); 1509 if (CheckDesignatedInitializer(MemberEntity, IList, DIE, DesigIdx + 1, 1510 FieldType, 0, 0, Index, 1511 StructuredList, newStructuredIndex, 1512 true, false)) 1513 return true; 1514 } 1515 1516 // Find the position of the next field to be initialized in this 1517 // subobject. 1518 ++Field; 1519 ++FieldIndex; 1520 1521 // If this the first designator, our caller will continue checking 1522 // the rest of this struct/class/union subobject. 1523 if (IsFirstDesignator) { 1524 if (NextField) 1525 *NextField = Field; 1526 StructuredIndex = FieldIndex; 1527 return false; 1528 } 1529 1530 if (!FinishSubobjectInit) 1531 return false; 1532 1533 // We've already initialized something in the union; we're done. 1534 if (RT->getDecl()->isUnion()) 1535 return hadError; 1536 1537 // Check the remaining fields within this class/struct/union subobject. 1538 bool prevHadError = hadError; 1539 1540 CheckStructUnionTypes(Entity, IList, CurrentObjectType, Field, false, Index, 1541 StructuredList, FieldIndex); 1542 return hadError && !prevHadError; 1543 } 1544 1545 // C99 6.7.8p6: 1546 // 1547 // If a designator has the form 1548 // 1549 // [ constant-expression ] 1550 // 1551 // then the current object (defined below) shall have array 1552 // type and the expression shall be an integer constant 1553 // expression. If the array is of unknown size, any 1554 // nonnegative value is valid. 1555 // 1556 // Additionally, cope with the GNU extension that permits 1557 // designators of the form 1558 // 1559 // [ constant-expression ... constant-expression ] 1560 const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType); 1561 if (!AT) { 1562 SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array) 1563 << CurrentObjectType; 1564 ++Index; 1565 return true; 1566 } 1567 1568 Expr *IndexExpr = 0; 1569 llvm::APSInt DesignatedStartIndex, DesignatedEndIndex; 1570 if (D->isArrayDesignator()) { 1571 IndexExpr = DIE->getArrayIndex(*D); 1572 DesignatedStartIndex = IndexExpr->EvaluateAsInt(SemaRef.Context); 1573 DesignatedEndIndex = DesignatedStartIndex; 1574 } else { 1575 assert(D->isArrayRangeDesignator() && "Need array-range designator"); 1576 1577 1578 DesignatedStartIndex = 1579 DIE->getArrayRangeStart(*D)->EvaluateAsInt(SemaRef.Context); 1580 DesignatedEndIndex = 1581 DIE->getArrayRangeEnd(*D)->EvaluateAsInt(SemaRef.Context); 1582 IndexExpr = DIE->getArrayRangeEnd(*D); 1583 1584 if (DesignatedStartIndex.getZExtValue() !=DesignatedEndIndex.getZExtValue()) 1585 FullyStructuredList->sawArrayRangeDesignator(); 1586 } 1587 1588 if (isa<ConstantArrayType>(AT)) { 1589 llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false); 1590 DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth()); 1591 DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned()); 1592 DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth()); 1593 DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned()); 1594 if (DesignatedEndIndex >= MaxElements) { 1595 SemaRef.Diag(IndexExpr->getSourceRange().getBegin(), 1596 diag::err_array_designator_too_large) 1597 << DesignatedEndIndex.toString(10) << MaxElements.toString(10) 1598 << IndexExpr->getSourceRange(); 1599 ++Index; 1600 return true; 1601 } 1602 } else { 1603 // Make sure the bit-widths and signedness match. 1604 if (DesignatedStartIndex.getBitWidth() > DesignatedEndIndex.getBitWidth()) 1605 DesignatedEndIndex.extend(DesignatedStartIndex.getBitWidth()); 1606 else if (DesignatedStartIndex.getBitWidth() < 1607 DesignatedEndIndex.getBitWidth()) 1608 DesignatedStartIndex.extend(DesignatedEndIndex.getBitWidth()); 1609 DesignatedStartIndex.setIsUnsigned(true); 1610 DesignatedEndIndex.setIsUnsigned(true); 1611 } 1612 1613 // Make sure that our non-designated initializer list has space 1614 // for a subobject corresponding to this array element. 1615 if (DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits()) 1616 StructuredList->resizeInits(SemaRef.Context, 1617 DesignatedEndIndex.getZExtValue() + 1); 1618 1619 // Repeatedly perform subobject initializations in the range 1620 // [DesignatedStartIndex, DesignatedEndIndex]. 1621 1622 // Move to the next designator 1623 unsigned ElementIndex = DesignatedStartIndex.getZExtValue(); 1624 unsigned OldIndex = Index; 1625 1626 InitializedEntity ElementEntity = 1627 InitializedEntity::InitializeElement(SemaRef.Context, 0, Entity); 1628 1629 while (DesignatedStartIndex <= DesignatedEndIndex) { 1630 // Recurse to check later designated subobjects. 1631 QualType ElementType = AT->getElementType(); 1632 Index = OldIndex; 1633 1634 ElementEntity.setElementIndex(ElementIndex); 1635 if (CheckDesignatedInitializer(ElementEntity, IList, DIE, DesigIdx + 1, 1636 ElementType, 0, 0, Index, 1637 StructuredList, ElementIndex, 1638 (DesignatedStartIndex == DesignatedEndIndex), 1639 false)) 1640 return true; 1641 1642 // Move to the next index in the array that we'll be initializing. 1643 ++DesignatedStartIndex; 1644 ElementIndex = DesignatedStartIndex.getZExtValue(); 1645 } 1646 1647 // If this the first designator, our caller will continue checking 1648 // the rest of this array subobject. 1649 if (IsFirstDesignator) { 1650 if (NextElementIndex) 1651 *NextElementIndex = DesignatedStartIndex; 1652 StructuredIndex = ElementIndex; 1653 return false; 1654 } 1655 1656 if (!FinishSubobjectInit) 1657 return false; 1658 1659 // Check the remaining elements within this array subobject. 1660 bool prevHadError = hadError; 1661 CheckArrayType(Entity, IList, CurrentObjectType, DesignatedStartIndex, 1662 /*SubobjectIsDesignatorContext=*/false, Index, 1663 StructuredList, ElementIndex); 1664 return hadError && !prevHadError; 1665} 1666 1667// Get the structured initializer list for a subobject of type 1668// @p CurrentObjectType. 1669InitListExpr * 1670InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index, 1671 QualType CurrentObjectType, 1672 InitListExpr *StructuredList, 1673 unsigned StructuredIndex, 1674 SourceRange InitRange) { 1675 Expr *ExistingInit = 0; 1676 if (!StructuredList) 1677 ExistingInit = SyntacticToSemantic[IList]; 1678 else if (StructuredIndex < StructuredList->getNumInits()) 1679 ExistingInit = StructuredList->getInit(StructuredIndex); 1680 1681 if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit)) 1682 return Result; 1683 1684 if (ExistingInit) { 1685 // We are creating an initializer list that initializes the 1686 // subobjects of the current object, but there was already an 1687 // initialization that completely initialized the current 1688 // subobject, e.g., by a compound literal: 1689 // 1690 // struct X { int a, b; }; 1691 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 }; 1692 // 1693 // Here, xs[0].a == 0 and xs[0].b == 3, since the second, 1694 // designated initializer re-initializes the whole 1695 // subobject [0], overwriting previous initializers. 1696 SemaRef.Diag(InitRange.getBegin(), 1697 diag::warn_subobject_initializer_overrides) 1698 << InitRange; 1699 SemaRef.Diag(ExistingInit->getSourceRange().getBegin(), 1700 diag::note_previous_initializer) 1701 << /*FIXME:has side effects=*/0 1702 << ExistingInit->getSourceRange(); 1703 } 1704 1705 InitListExpr *Result 1706 = new (SemaRef.Context) InitListExpr(SemaRef.Context, 1707 InitRange.getBegin(), 0, 0, 1708 InitRange.getEnd()); 1709 1710 Result->setType(CurrentObjectType.getNonReferenceType()); 1711 1712 // Pre-allocate storage for the structured initializer list. 1713 unsigned NumElements = 0; 1714 unsigned NumInits = 0; 1715 if (!StructuredList) 1716 NumInits = IList->getNumInits(); 1717 else if (Index < IList->getNumInits()) { 1718 if (InitListExpr *SubList = dyn_cast<InitListExpr>(IList->getInit(Index))) 1719 NumInits = SubList->getNumInits(); 1720 } 1721 1722 if (const ArrayType *AType 1723 = SemaRef.Context.getAsArrayType(CurrentObjectType)) { 1724 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) { 1725 NumElements = CAType->getSize().getZExtValue(); 1726 // Simple heuristic so that we don't allocate a very large 1727 // initializer with many empty entries at the end. 1728 if (NumInits && NumElements > NumInits) 1729 NumElements = 0; 1730 } 1731 } else if (const VectorType *VType = CurrentObjectType->getAs<VectorType>()) 1732 NumElements = VType->getNumElements(); 1733 else if (const RecordType *RType = CurrentObjectType->getAs<RecordType>()) { 1734 RecordDecl *RDecl = RType->getDecl(); 1735 if (RDecl->isUnion()) 1736 NumElements = 1; 1737 else 1738 NumElements = std::distance(RDecl->field_begin(), 1739 RDecl->field_end()); 1740 } 1741 1742 if (NumElements < NumInits) 1743 NumElements = IList->getNumInits(); 1744 1745 Result->reserveInits(SemaRef.Context, NumElements); 1746 1747 // Link this new initializer list into the structured initializer 1748 // lists. 1749 if (StructuredList) 1750 StructuredList->updateInit(SemaRef.Context, StructuredIndex, Result); 1751 else { 1752 Result->setSyntacticForm(IList); 1753 SyntacticToSemantic[IList] = Result; 1754 } 1755 1756 return Result; 1757} 1758 1759/// Update the initializer at index @p StructuredIndex within the 1760/// structured initializer list to the value @p expr. 1761void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList, 1762 unsigned &StructuredIndex, 1763 Expr *expr) { 1764 // No structured initializer list to update 1765 if (!StructuredList) 1766 return; 1767 1768 if (Expr *PrevInit = StructuredList->updateInit(SemaRef.Context, 1769 StructuredIndex, expr)) { 1770 // This initializer overwrites a previous initializer. Warn. 1771 SemaRef.Diag(expr->getSourceRange().getBegin(), 1772 diag::warn_initializer_overrides) 1773 << expr->getSourceRange(); 1774 SemaRef.Diag(PrevInit->getSourceRange().getBegin(), 1775 diag::note_previous_initializer) 1776 << /*FIXME:has side effects=*/0 1777 << PrevInit->getSourceRange(); 1778 } 1779 1780 ++StructuredIndex; 1781} 1782 1783/// Check that the given Index expression is a valid array designator 1784/// value. This is essentailly just a wrapper around 1785/// VerifyIntegerConstantExpression that also checks for negative values 1786/// and produces a reasonable diagnostic if there is a 1787/// failure. Returns true if there was an error, false otherwise. If 1788/// everything went okay, Value will receive the value of the constant 1789/// expression. 1790static bool 1791CheckArrayDesignatorExpr(Sema &S, Expr *Index, llvm::APSInt &Value) { 1792 SourceLocation Loc = Index->getSourceRange().getBegin(); 1793 1794 // Make sure this is an integer constant expression. 1795 if (S.VerifyIntegerConstantExpression(Index, &Value)) 1796 return true; 1797 1798 if (Value.isSigned() && Value.isNegative()) 1799 return S.Diag(Loc, diag::err_array_designator_negative) 1800 << Value.toString(10) << Index->getSourceRange(); 1801 1802 Value.setIsUnsigned(true); 1803 return false; 1804} 1805 1806Sema::OwningExprResult Sema::ActOnDesignatedInitializer(Designation &Desig, 1807 SourceLocation Loc, 1808 bool GNUSyntax, 1809 OwningExprResult Init) { 1810 typedef DesignatedInitExpr::Designator ASTDesignator; 1811 1812 bool Invalid = false; 1813 llvm::SmallVector<ASTDesignator, 32> Designators; 1814 llvm::SmallVector<Expr *, 32> InitExpressions; 1815 1816 // Build designators and check array designator expressions. 1817 for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) { 1818 const Designator &D = Desig.getDesignator(Idx); 1819 switch (D.getKind()) { 1820 case Designator::FieldDesignator: 1821 Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(), 1822 D.getFieldLoc())); 1823 break; 1824 1825 case Designator::ArrayDesignator: { 1826 Expr *Index = static_cast<Expr *>(D.getArrayIndex()); 1827 llvm::APSInt IndexValue; 1828 if (!Index->isTypeDependent() && 1829 !Index->isValueDependent() && 1830 CheckArrayDesignatorExpr(*this, Index, IndexValue)) 1831 Invalid = true; 1832 else { 1833 Designators.push_back(ASTDesignator(InitExpressions.size(), 1834 D.getLBracketLoc(), 1835 D.getRBracketLoc())); 1836 InitExpressions.push_back(Index); 1837 } 1838 break; 1839 } 1840 1841 case Designator::ArrayRangeDesignator: { 1842 Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart()); 1843 Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd()); 1844 llvm::APSInt StartValue; 1845 llvm::APSInt EndValue; 1846 bool StartDependent = StartIndex->isTypeDependent() || 1847 StartIndex->isValueDependent(); 1848 bool EndDependent = EndIndex->isTypeDependent() || 1849 EndIndex->isValueDependent(); 1850 if ((!StartDependent && 1851 CheckArrayDesignatorExpr(*this, StartIndex, StartValue)) || 1852 (!EndDependent && 1853 CheckArrayDesignatorExpr(*this, EndIndex, EndValue))) 1854 Invalid = true; 1855 else { 1856 // Make sure we're comparing values with the same bit width. 1857 if (StartDependent || EndDependent) { 1858 // Nothing to compute. 1859 } else if (StartValue.getBitWidth() > EndValue.getBitWidth()) 1860 EndValue.extend(StartValue.getBitWidth()); 1861 else if (StartValue.getBitWidth() < EndValue.getBitWidth()) 1862 StartValue.extend(EndValue.getBitWidth()); 1863 1864 if (!StartDependent && !EndDependent && EndValue < StartValue) { 1865 Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range) 1866 << StartValue.toString(10) << EndValue.toString(10) 1867 << StartIndex->getSourceRange() << EndIndex->getSourceRange(); 1868 Invalid = true; 1869 } else { 1870 Designators.push_back(ASTDesignator(InitExpressions.size(), 1871 D.getLBracketLoc(), 1872 D.getEllipsisLoc(), 1873 D.getRBracketLoc())); 1874 InitExpressions.push_back(StartIndex); 1875 InitExpressions.push_back(EndIndex); 1876 } 1877 } 1878 break; 1879 } 1880 } 1881 } 1882 1883 if (Invalid || Init.isInvalid()) 1884 return ExprError(); 1885 1886 // Clear out the expressions within the designation. 1887 Desig.ClearExprs(*this); 1888 1889 DesignatedInitExpr *DIE 1890 = DesignatedInitExpr::Create(Context, 1891 Designators.data(), Designators.size(), 1892 InitExpressions.data(), InitExpressions.size(), 1893 Loc, GNUSyntax, Init.takeAs<Expr>()); 1894 return Owned(DIE); 1895} 1896 1897bool Sema::CheckInitList(const InitializedEntity &Entity, 1898 InitListExpr *&InitList, QualType &DeclType) { 1899 InitListChecker CheckInitList(*this, Entity, InitList, DeclType); 1900 if (!CheckInitList.HadError()) 1901 InitList = CheckInitList.getFullyStructuredList(); 1902 1903 return CheckInitList.HadError(); 1904} 1905 1906//===----------------------------------------------------------------------===// 1907// Initialization entity 1908//===----------------------------------------------------------------------===// 1909 1910InitializedEntity::InitializedEntity(ASTContext &Context, unsigned Index, 1911 const InitializedEntity &Parent) 1912 : Parent(&Parent), Index(Index) 1913{ 1914 if (const ArrayType *AT = Context.getAsArrayType(Parent.getType())) { 1915 Kind = EK_ArrayElement; 1916 Type = AT->getElementType(); 1917 } else { 1918 Kind = EK_VectorElement; 1919 Type = Parent.getType()->getAs<VectorType>()->getElementType(); 1920 } 1921} 1922 1923InitializedEntity InitializedEntity::InitializeBase(ASTContext &Context, 1924 CXXBaseSpecifier *Base) 1925{ 1926 InitializedEntity Result; 1927 Result.Kind = EK_Base; 1928 Result.Base = Base; 1929 Result.Type = Base->getType(); 1930 return Result; 1931} 1932 1933DeclarationName InitializedEntity::getName() const { 1934 switch (getKind()) { 1935 case EK_Parameter: 1936 if (!VariableOrMember) 1937 return DeclarationName(); 1938 // Fall through 1939 1940 case EK_Variable: 1941 case EK_Member: 1942 return VariableOrMember->getDeclName(); 1943 1944 case EK_Result: 1945 case EK_Exception: 1946 case EK_New: 1947 case EK_Temporary: 1948 case EK_Base: 1949 case EK_ArrayElement: 1950 case EK_VectorElement: 1951 return DeclarationName(); 1952 } 1953 1954 // Silence GCC warning 1955 return DeclarationName(); 1956} 1957 1958DeclaratorDecl *InitializedEntity::getDecl() const { 1959 switch (getKind()) { 1960 case EK_Variable: 1961 case EK_Parameter: 1962 case EK_Member: 1963 return VariableOrMember; 1964 1965 case EK_Result: 1966 case EK_Exception: 1967 case EK_New: 1968 case EK_Temporary: 1969 case EK_Base: 1970 case EK_ArrayElement: 1971 case EK_VectorElement: 1972 return 0; 1973 } 1974 1975 // Silence GCC warning 1976 return 0; 1977} 1978 1979//===----------------------------------------------------------------------===// 1980// Initialization sequence 1981//===----------------------------------------------------------------------===// 1982 1983void InitializationSequence::Step::Destroy() { 1984 switch (Kind) { 1985 case SK_ResolveAddressOfOverloadedFunction: 1986 case SK_CastDerivedToBaseRValue: 1987 case SK_CastDerivedToBaseLValue: 1988 case SK_BindReference: 1989 case SK_BindReferenceToTemporary: 1990 case SK_UserConversion: 1991 case SK_QualificationConversionRValue: 1992 case SK_QualificationConversionLValue: 1993 case SK_ListInitialization: 1994 case SK_ConstructorInitialization: 1995 case SK_ZeroInitialization: 1996 case SK_CAssignment: 1997 case SK_StringInit: 1998 break; 1999 2000 case SK_ConversionSequence: 2001 delete ICS; 2002 } 2003} 2004 2005bool InitializationSequence::isDirectReferenceBinding() const { 2006 return getKind() == ReferenceBinding && Steps.back().Kind == SK_BindReference; 2007} 2008 2009bool InitializationSequence::isAmbiguous() const { 2010 if (getKind() != FailedSequence) 2011 return false; 2012 2013 switch (getFailureKind()) { 2014 case FK_TooManyInitsForReference: 2015 case FK_ArrayNeedsInitList: 2016 case FK_ArrayNeedsInitListOrStringLiteral: 2017 case FK_AddressOfOverloadFailed: // FIXME: Could do better 2018 case FK_NonConstLValueReferenceBindingToTemporary: 2019 case FK_NonConstLValueReferenceBindingToUnrelated: 2020 case FK_RValueReferenceBindingToLValue: 2021 case FK_ReferenceInitDropsQualifiers: 2022 case FK_ReferenceInitFailed: 2023 case FK_ConversionFailed: 2024 case FK_TooManyInitsForScalar: 2025 case FK_ReferenceBindingToInitList: 2026 case FK_InitListBadDestinationType: 2027 case FK_DefaultInitOfConst: 2028 return false; 2029 2030 case FK_ReferenceInitOverloadFailed: 2031 case FK_UserConversionOverloadFailed: 2032 case FK_ConstructorOverloadFailed: 2033 return FailedOverloadResult == OR_Ambiguous; 2034 } 2035 2036 return false; 2037} 2038 2039bool InitializationSequence::isConstructorInitialization() const { 2040 return !Steps.empty() && Steps.back().Kind == SK_ConstructorInitialization; 2041} 2042 2043void InitializationSequence::AddAddressOverloadResolutionStep( 2044 FunctionDecl *Function, 2045 DeclAccessPair Found) { 2046 Step S; 2047 S.Kind = SK_ResolveAddressOfOverloadedFunction; 2048 S.Type = Function->getType(); 2049 S.Function.Function = Function; 2050 S.Function.FoundDecl = Found; 2051 Steps.push_back(S); 2052} 2053 2054void InitializationSequence::AddDerivedToBaseCastStep(QualType BaseType, 2055 bool IsLValue) { 2056 Step S; 2057 S.Kind = IsLValue? SK_CastDerivedToBaseLValue : SK_CastDerivedToBaseRValue; 2058 S.Type = BaseType; 2059 Steps.push_back(S); 2060} 2061 2062void InitializationSequence::AddReferenceBindingStep(QualType T, 2063 bool BindingTemporary) { 2064 Step S; 2065 S.Kind = BindingTemporary? SK_BindReferenceToTemporary : SK_BindReference; 2066 S.Type = T; 2067 Steps.push_back(S); 2068} 2069 2070void InitializationSequence::AddUserConversionStep(FunctionDecl *Function, 2071 DeclAccessPair FoundDecl, 2072 QualType T) { 2073 Step S; 2074 S.Kind = SK_UserConversion; 2075 S.Type = T; 2076 S.Function.Function = Function; 2077 S.Function.FoundDecl = FoundDecl; 2078 Steps.push_back(S); 2079} 2080 2081void InitializationSequence::AddQualificationConversionStep(QualType Ty, 2082 bool IsLValue) { 2083 Step S; 2084 S.Kind = IsLValue? SK_QualificationConversionLValue 2085 : SK_QualificationConversionRValue; 2086 S.Type = Ty; 2087 Steps.push_back(S); 2088} 2089 2090void InitializationSequence::AddConversionSequenceStep( 2091 const ImplicitConversionSequence &ICS, 2092 QualType T) { 2093 Step S; 2094 S.Kind = SK_ConversionSequence; 2095 S.Type = T; 2096 S.ICS = new ImplicitConversionSequence(ICS); 2097 Steps.push_back(S); 2098} 2099 2100void InitializationSequence::AddListInitializationStep(QualType T) { 2101 Step S; 2102 S.Kind = SK_ListInitialization; 2103 S.Type = T; 2104 Steps.push_back(S); 2105} 2106 2107void 2108InitializationSequence::AddConstructorInitializationStep( 2109 CXXConstructorDecl *Constructor, 2110 AccessSpecifier Access, 2111 QualType T) { 2112 Step S; 2113 S.Kind = SK_ConstructorInitialization; 2114 S.Type = T; 2115 S.Function.Function = Constructor; 2116 S.Function.FoundDecl = DeclAccessPair::make(Constructor, Access); 2117 Steps.push_back(S); 2118} 2119 2120void InitializationSequence::AddZeroInitializationStep(QualType T) { 2121 Step S; 2122 S.Kind = SK_ZeroInitialization; 2123 S.Type = T; 2124 Steps.push_back(S); 2125} 2126 2127void InitializationSequence::AddCAssignmentStep(QualType T) { 2128 Step S; 2129 S.Kind = SK_CAssignment; 2130 S.Type = T; 2131 Steps.push_back(S); 2132} 2133 2134void InitializationSequence::AddStringInitStep(QualType T) { 2135 Step S; 2136 S.Kind = SK_StringInit; 2137 S.Type = T; 2138 Steps.push_back(S); 2139} 2140 2141void InitializationSequence::SetOverloadFailure(FailureKind Failure, 2142 OverloadingResult Result) { 2143 SequenceKind = FailedSequence; 2144 this->Failure = Failure; 2145 this->FailedOverloadResult = Result; 2146} 2147 2148//===----------------------------------------------------------------------===// 2149// Attempt initialization 2150//===----------------------------------------------------------------------===// 2151 2152/// \brief Attempt list initialization (C++0x [dcl.init.list]) 2153static void TryListInitialization(Sema &S, 2154 const InitializedEntity &Entity, 2155 const InitializationKind &Kind, 2156 InitListExpr *InitList, 2157 InitializationSequence &Sequence) { 2158 // FIXME: We only perform rudimentary checking of list 2159 // initializations at this point, then assume that any list 2160 // initialization of an array, aggregate, or scalar will be 2161 // well-formed. We we actually "perform" list initialization, we'll 2162 // do all of the necessary checking. C++0x initializer lists will 2163 // force us to perform more checking here. 2164 Sequence.setSequenceKind(InitializationSequence::ListInitialization); 2165 2166 QualType DestType = Entity.getType(); 2167 2168 // C++ [dcl.init]p13: 2169 // If T is a scalar type, then a declaration of the form 2170 // 2171 // T x = { a }; 2172 // 2173 // is equivalent to 2174 // 2175 // T x = a; 2176 if (DestType->isScalarType()) { 2177 if (InitList->getNumInits() > 1 && S.getLangOptions().CPlusPlus) { 2178 Sequence.SetFailed(InitializationSequence::FK_TooManyInitsForScalar); 2179 return; 2180 } 2181 2182 // Assume scalar initialization from a single value works. 2183 } else if (DestType->isAggregateType()) { 2184 // Assume aggregate initialization works. 2185 } else if (DestType->isVectorType()) { 2186 // Assume vector initialization works. 2187 } else if (DestType->isReferenceType()) { 2188 // FIXME: C++0x defines behavior for this. 2189 Sequence.SetFailed(InitializationSequence::FK_ReferenceBindingToInitList); 2190 return; 2191 } else if (DestType->isRecordType()) { 2192 // FIXME: C++0x defines behavior for this 2193 Sequence.SetFailed(InitializationSequence::FK_InitListBadDestinationType); 2194 } 2195 2196 // Add a general "list initialization" step. 2197 Sequence.AddListInitializationStep(DestType); 2198} 2199 2200/// \brief Try a reference initialization that involves calling a conversion 2201/// function. 2202/// 2203/// FIXME: look intos DRs 656, 896 2204static OverloadingResult TryRefInitWithConversionFunction(Sema &S, 2205 const InitializedEntity &Entity, 2206 const InitializationKind &Kind, 2207 Expr *Initializer, 2208 bool AllowRValues, 2209 InitializationSequence &Sequence) { 2210 QualType DestType = Entity.getType(); 2211 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 2212 QualType T1 = cv1T1.getUnqualifiedType(); 2213 QualType cv2T2 = Initializer->getType(); 2214 QualType T2 = cv2T2.getUnqualifiedType(); 2215 2216 bool DerivedToBase; 2217 assert(!S.CompareReferenceRelationship(Initializer->getLocStart(), 2218 T1, T2, DerivedToBase) && 2219 "Must have incompatible references when binding via conversion"); 2220 (void)DerivedToBase; 2221 2222 // Build the candidate set directly in the initialization sequence 2223 // structure, so that it will persist if we fail. 2224 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 2225 CandidateSet.clear(); 2226 2227 // Determine whether we are allowed to call explicit constructors or 2228 // explicit conversion operators. 2229 bool AllowExplicit = Kind.getKind() == InitializationKind::IK_Direct; 2230 2231 const RecordType *T1RecordType = 0; 2232 if (AllowRValues && (T1RecordType = T1->getAs<RecordType>())) { 2233 // The type we're converting to is a class type. Enumerate its constructors 2234 // to see if there is a suitable conversion. 2235 CXXRecordDecl *T1RecordDecl = cast<CXXRecordDecl>(T1RecordType->getDecl()); 2236 2237 DeclarationName ConstructorName 2238 = S.Context.DeclarationNames.getCXXConstructorName( 2239 S.Context.getCanonicalType(T1).getUnqualifiedType()); 2240 DeclContext::lookup_iterator Con, ConEnd; 2241 for (llvm::tie(Con, ConEnd) = T1RecordDecl->lookup(ConstructorName); 2242 Con != ConEnd; ++Con) { 2243 NamedDecl *D = *Con; 2244 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2245 2246 // Find the constructor (which may be a template). 2247 CXXConstructorDecl *Constructor = 0; 2248 FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D); 2249 if (ConstructorTmpl) 2250 Constructor = cast<CXXConstructorDecl>( 2251 ConstructorTmpl->getTemplatedDecl()); 2252 else 2253 Constructor = cast<CXXConstructorDecl>(D); 2254 2255 if (!Constructor->isInvalidDecl() && 2256 Constructor->isConvertingConstructor(AllowExplicit)) { 2257 if (ConstructorTmpl) 2258 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2259 /*ExplicitArgs*/ 0, 2260 &Initializer, 1, CandidateSet); 2261 else 2262 S.AddOverloadCandidate(Constructor, FoundDecl, 2263 &Initializer, 1, CandidateSet); 2264 } 2265 } 2266 } 2267 2268 if (const RecordType *T2RecordType = T2->getAs<RecordType>()) { 2269 // The type we're converting from is a class type, enumerate its conversion 2270 // functions. 2271 CXXRecordDecl *T2RecordDecl = cast<CXXRecordDecl>(T2RecordType->getDecl()); 2272 2273 // Determine the type we are converting to. If we are allowed to 2274 // convert to an rvalue, take the type that the destination type 2275 // refers to. 2276 QualType ToType = AllowRValues? cv1T1 : DestType; 2277 2278 const UnresolvedSetImpl *Conversions 2279 = T2RecordDecl->getVisibleConversionFunctions(); 2280 for (UnresolvedSetImpl::const_iterator I = Conversions->begin(), 2281 E = Conversions->end(); I != E; ++I) { 2282 NamedDecl *D = *I; 2283 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2284 if (isa<UsingShadowDecl>(D)) 2285 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2286 2287 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D); 2288 CXXConversionDecl *Conv; 2289 if (ConvTemplate) 2290 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2291 else 2292 Conv = cast<CXXConversionDecl>(*I); 2293 2294 // If the conversion function doesn't return a reference type, 2295 // it can't be considered for this conversion unless we're allowed to 2296 // consider rvalues. 2297 // FIXME: Do we need to make sure that we only consider conversion 2298 // candidates with reference-compatible results? That might be needed to 2299 // break recursion. 2300 if ((AllowExplicit || !Conv->isExplicit()) && 2301 (AllowRValues || Conv->getConversionType()->isLValueReferenceType())){ 2302 if (ConvTemplate) 2303 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), 2304 ActingDC, Initializer, 2305 ToType, CandidateSet); 2306 else 2307 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, 2308 Initializer, ToType, CandidateSet); 2309 } 2310 } 2311 } 2312 2313 SourceLocation DeclLoc = Initializer->getLocStart(); 2314 2315 // Perform overload resolution. If it fails, return the failed result. 2316 OverloadCandidateSet::iterator Best; 2317 if (OverloadingResult Result 2318 = S.BestViableFunction(CandidateSet, DeclLoc, Best)) 2319 return Result; 2320 2321 FunctionDecl *Function = Best->Function; 2322 2323 // Compute the returned type of the conversion. 2324 if (isa<CXXConversionDecl>(Function)) 2325 T2 = Function->getResultType(); 2326 else 2327 T2 = cv1T1; 2328 2329 // Add the user-defined conversion step. 2330 Sequence.AddUserConversionStep(Function, Best->FoundDecl, 2331 T2.getNonReferenceType()); 2332 2333 // Determine whether we need to perform derived-to-base or 2334 // cv-qualification adjustments. 2335 bool NewDerivedToBase = false; 2336 Sema::ReferenceCompareResult NewRefRelationship 2337 = S.CompareReferenceRelationship(DeclLoc, T1, T2.getNonReferenceType(), 2338 NewDerivedToBase); 2339 if (NewRefRelationship == Sema::Ref_Incompatible) { 2340 // If the type we've converted to is not reference-related to the 2341 // type we're looking for, then there is another conversion step 2342 // we need to perform to produce a temporary of the right type 2343 // that we'll be binding to. 2344 ImplicitConversionSequence ICS; 2345 ICS.setStandard(); 2346 ICS.Standard = Best->FinalConversion; 2347 T2 = ICS.Standard.getToType(2); 2348 Sequence.AddConversionSequenceStep(ICS, T2); 2349 } else if (NewDerivedToBase) 2350 Sequence.AddDerivedToBaseCastStep( 2351 S.Context.getQualifiedType(T1, 2352 T2.getNonReferenceType().getQualifiers()), 2353 /*isLValue=*/true); 2354 2355 if (cv1T1.getQualifiers() != T2.getNonReferenceType().getQualifiers()) 2356 Sequence.AddQualificationConversionStep(cv1T1, T2->isReferenceType()); 2357 2358 Sequence.AddReferenceBindingStep(cv1T1, !T2->isReferenceType()); 2359 return OR_Success; 2360} 2361 2362/// \brief Attempt reference initialization (C++0x [dcl.init.list]) 2363static void TryReferenceInitialization(Sema &S, 2364 const InitializedEntity &Entity, 2365 const InitializationKind &Kind, 2366 Expr *Initializer, 2367 InitializationSequence &Sequence) { 2368 Sequence.setSequenceKind(InitializationSequence::ReferenceBinding); 2369 2370 QualType DestType = Entity.getType(); 2371 QualType cv1T1 = DestType->getAs<ReferenceType>()->getPointeeType(); 2372 Qualifiers T1Quals; 2373 QualType T1 = S.Context.getUnqualifiedArrayType(cv1T1, T1Quals); 2374 QualType cv2T2 = Initializer->getType(); 2375 Qualifiers T2Quals; 2376 QualType T2 = S.Context.getUnqualifiedArrayType(cv2T2, T2Quals); 2377 SourceLocation DeclLoc = Initializer->getLocStart(); 2378 2379 // If the initializer is the address of an overloaded function, try 2380 // to resolve the overloaded function. If all goes well, T2 is the 2381 // type of the resulting function. 2382 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2383 DeclAccessPair Found; 2384 FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Initializer, 2385 T1, 2386 false, 2387 Found); 2388 if (!Fn) { 2389 Sequence.SetFailed(InitializationSequence::FK_AddressOfOverloadFailed); 2390 return; 2391 } 2392 2393 Sequence.AddAddressOverloadResolutionStep(Fn, Found); 2394 cv2T2 = Fn->getType(); 2395 T2 = cv2T2.getUnqualifiedType(); 2396 } 2397 2398 // Compute some basic properties of the types and the initializer. 2399 bool isLValueRef = DestType->isLValueReferenceType(); 2400 bool isRValueRef = !isLValueRef; 2401 bool DerivedToBase = false; 2402 Expr::isLvalueResult InitLvalue = Initializer->isLvalue(S.Context); 2403 Sema::ReferenceCompareResult RefRelationship 2404 = S.CompareReferenceRelationship(DeclLoc, cv1T1, cv2T2, DerivedToBase); 2405 2406 // C++0x [dcl.init.ref]p5: 2407 // A reference to type "cv1 T1" is initialized by an expression of type 2408 // "cv2 T2" as follows: 2409 // 2410 // - If the reference is an lvalue reference and the initializer 2411 // expression 2412 OverloadingResult ConvOvlResult = OR_Success; 2413 if (isLValueRef) { 2414 if (InitLvalue == Expr::LV_Valid && 2415 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2416 // - is an lvalue (but is not a bit-field), and "cv1 T1" is 2417 // reference-compatible with "cv2 T2," or 2418 // 2419 // Per C++ [over.best.ics]p2, we don't diagnose whether the lvalue is a 2420 // bit-field when we're determining whether the reference initialization 2421 // can occur. However, we do pay attention to whether it is a bit-field 2422 // to decide whether we're actually binding to a temporary created from 2423 // the bit-field. 2424 if (DerivedToBase) 2425 Sequence.AddDerivedToBaseCastStep( 2426 S.Context.getQualifiedType(T1, T2Quals), 2427 /*isLValue=*/true); 2428 if (T1Quals != T2Quals) 2429 Sequence.AddQualificationConversionStep(cv1T1, /*IsLValue=*/true); 2430 bool BindingTemporary = T1Quals.hasConst() && !T1Quals.hasVolatile() && 2431 (Initializer->getBitField() || Initializer->refersToVectorElement()); 2432 Sequence.AddReferenceBindingStep(cv1T1, BindingTemporary); 2433 return; 2434 } 2435 2436 // - has a class type (i.e., T2 is a class type), where T1 is not 2437 // reference-related to T2, and can be implicitly converted to an 2438 // lvalue of type "cv3 T3," where "cv1 T1" is reference-compatible 2439 // with "cv3 T3" (this conversion is selected by enumerating the 2440 // applicable conversion functions (13.3.1.6) and choosing the best 2441 // one through overload resolution (13.3)), 2442 if (RefRelationship == Sema::Ref_Incompatible && T2->isRecordType()) { 2443 ConvOvlResult = TryRefInitWithConversionFunction(S, Entity, Kind, 2444 Initializer, 2445 /*AllowRValues=*/false, 2446 Sequence); 2447 if (ConvOvlResult == OR_Success) 2448 return; 2449 if (ConvOvlResult != OR_No_Viable_Function) { 2450 Sequence.SetOverloadFailure( 2451 InitializationSequence::FK_ReferenceInitOverloadFailed, 2452 ConvOvlResult); 2453 } 2454 } 2455 } 2456 2457 // - Otherwise, the reference shall be an lvalue reference to a 2458 // non-volatile const type (i.e., cv1 shall be const), or the reference 2459 // shall be an rvalue reference and the initializer expression shall 2460 // be an rvalue. 2461 if (!((isLValueRef && T1Quals.hasConst() && !T1Quals.hasVolatile()) || 2462 (isRValueRef && InitLvalue != Expr::LV_Valid))) { 2463 if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty()) 2464 Sequence.SetOverloadFailure( 2465 InitializationSequence::FK_ReferenceInitOverloadFailed, 2466 ConvOvlResult); 2467 else if (isLValueRef) 2468 Sequence.SetFailed(InitLvalue == Expr::LV_Valid 2469 ? (RefRelationship == Sema::Ref_Related 2470 ? InitializationSequence::FK_ReferenceInitDropsQualifiers 2471 : InitializationSequence::FK_NonConstLValueReferenceBindingToUnrelated) 2472 : InitializationSequence::FK_NonConstLValueReferenceBindingToTemporary); 2473 else 2474 Sequence.SetFailed( 2475 InitializationSequence::FK_RValueReferenceBindingToLValue); 2476 2477 return; 2478 } 2479 2480 // - If T1 and T2 are class types and 2481 if (T1->isRecordType() && T2->isRecordType()) { 2482 // - the initializer expression is an rvalue and "cv1 T1" is 2483 // reference-compatible with "cv2 T2", or 2484 if (InitLvalue != Expr::LV_Valid && 2485 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2486 if (DerivedToBase) 2487 Sequence.AddDerivedToBaseCastStep( 2488 S.Context.getQualifiedType(T1, T2Quals), 2489 /*isLValue=*/false); 2490 if (T1Quals != T2Quals) 2491 Sequence.AddQualificationConversionStep(cv1T1, /*IsLValue=*/false); 2492 Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true); 2493 return; 2494 } 2495 2496 // - T1 is not reference-related to T2 and the initializer expression 2497 // can be implicitly converted to an rvalue of type "cv3 T3" (this 2498 // conversion is selected by enumerating the applicable conversion 2499 // functions (13.3.1.6) and choosing the best one through overload 2500 // resolution (13.3)), 2501 if (RefRelationship == Sema::Ref_Incompatible) { 2502 ConvOvlResult = TryRefInitWithConversionFunction(S, Entity, 2503 Kind, Initializer, 2504 /*AllowRValues=*/true, 2505 Sequence); 2506 if (ConvOvlResult) 2507 Sequence.SetOverloadFailure( 2508 InitializationSequence::FK_ReferenceInitOverloadFailed, 2509 ConvOvlResult); 2510 2511 return; 2512 } 2513 2514 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers); 2515 return; 2516 } 2517 2518 // - If the initializer expression is an rvalue, with T2 an array type, 2519 // and "cv1 T1" is reference-compatible with "cv2 T2," the reference 2520 // is bound to the object represented by the rvalue (see 3.10). 2521 // FIXME: How can an array type be reference-compatible with anything? 2522 // Don't we mean the element types of T1 and T2? 2523 2524 // - Otherwise, a temporary of type “cv1 T1” is created and initialized 2525 // from the initializer expression using the rules for a non-reference 2526 // copy initialization (8.5). The reference is then bound to the 2527 // temporary. [...] 2528 // Determine whether we are allowed to call explicit constructors or 2529 // explicit conversion operators. 2530 bool AllowExplicit = (Kind.getKind() == InitializationKind::IK_Direct); 2531 ImplicitConversionSequence ICS 2532 = S.TryImplicitConversion(Initializer, cv1T1, 2533 /*SuppressUserConversions=*/false, AllowExplicit, 2534 /*FIXME:InOverloadResolution=*/false); 2535 2536 if (ICS.isBad()) { 2537 // FIXME: Use the conversion function set stored in ICS to turn 2538 // this into an overloading ambiguity diagnostic. However, we need 2539 // to keep that set as an OverloadCandidateSet rather than as some 2540 // other kind of set. 2541 if (ConvOvlResult && !Sequence.getFailedCandidateSet().empty()) 2542 Sequence.SetOverloadFailure( 2543 InitializationSequence::FK_ReferenceInitOverloadFailed, 2544 ConvOvlResult); 2545 else 2546 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitFailed); 2547 return; 2548 } 2549 2550 // [...] If T1 is reference-related to T2, cv1 must be the 2551 // same cv-qualification as, or greater cv-qualification 2552 // than, cv2; otherwise, the program is ill-formed. 2553 unsigned T1CVRQuals = T1Quals.getCVRQualifiers(); 2554 unsigned T2CVRQuals = T2Quals.getCVRQualifiers(); 2555 if (RefRelationship == Sema::Ref_Related && 2556 (T1CVRQuals | T2CVRQuals) != T1CVRQuals) { 2557 Sequence.SetFailed(InitializationSequence::FK_ReferenceInitDropsQualifiers); 2558 return; 2559 } 2560 2561 // Perform the actual conversion. 2562 Sequence.AddConversionSequenceStep(ICS, cv1T1); 2563 Sequence.AddReferenceBindingStep(cv1T1, /*bindingTemporary=*/true); 2564 return; 2565} 2566 2567/// \brief Attempt character array initialization from a string literal 2568/// (C++ [dcl.init.string], C99 6.7.8). 2569static void TryStringLiteralInitialization(Sema &S, 2570 const InitializedEntity &Entity, 2571 const InitializationKind &Kind, 2572 Expr *Initializer, 2573 InitializationSequence &Sequence) { 2574 Sequence.setSequenceKind(InitializationSequence::StringInit); 2575 Sequence.AddStringInitStep(Entity.getType()); 2576} 2577 2578/// \brief Attempt initialization by constructor (C++ [dcl.init]), which 2579/// enumerates the constructors of the initialized entity and performs overload 2580/// resolution to select the best. 2581static void TryConstructorInitialization(Sema &S, 2582 const InitializedEntity &Entity, 2583 const InitializationKind &Kind, 2584 Expr **Args, unsigned NumArgs, 2585 QualType DestType, 2586 InitializationSequence &Sequence) { 2587 Sequence.setSequenceKind(InitializationSequence::ConstructorInitialization); 2588 2589 // Build the candidate set directly in the initialization sequence 2590 // structure, so that it will persist if we fail. 2591 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 2592 CandidateSet.clear(); 2593 2594 // Determine whether we are allowed to call explicit constructors or 2595 // explicit conversion operators. 2596 bool AllowExplicit = (Kind.getKind() == InitializationKind::IK_Direct || 2597 Kind.getKind() == InitializationKind::IK_Value || 2598 Kind.getKind() == InitializationKind::IK_Default); 2599 2600 // The type we're converting to is a class type. Enumerate its constructors 2601 // to see if one is suitable. 2602 const RecordType *DestRecordType = DestType->getAs<RecordType>(); 2603 assert(DestRecordType && "Constructor initialization requires record type"); 2604 CXXRecordDecl *DestRecordDecl 2605 = cast<CXXRecordDecl>(DestRecordType->getDecl()); 2606 2607 DeclarationName ConstructorName 2608 = S.Context.DeclarationNames.getCXXConstructorName( 2609 S.Context.getCanonicalType(DestType).getUnqualifiedType()); 2610 DeclContext::lookup_iterator Con, ConEnd; 2611 for (llvm::tie(Con, ConEnd) = DestRecordDecl->lookup(ConstructorName); 2612 Con != ConEnd; ++Con) { 2613 NamedDecl *D = *Con; 2614 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2615 2616 // Find the constructor (which may be a template). 2617 CXXConstructorDecl *Constructor = 0; 2618 FunctionTemplateDecl *ConstructorTmpl = dyn_cast<FunctionTemplateDecl>(D); 2619 if (ConstructorTmpl) 2620 Constructor = cast<CXXConstructorDecl>( 2621 ConstructorTmpl->getTemplatedDecl()); 2622 else 2623 Constructor = cast<CXXConstructorDecl>(D); 2624 2625 if (!Constructor->isInvalidDecl() && 2626 (AllowExplicit || !Constructor->isExplicit())) { 2627 if (ConstructorTmpl) 2628 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2629 /*ExplicitArgs*/ 0, 2630 Args, NumArgs, CandidateSet); 2631 else 2632 S.AddOverloadCandidate(Constructor, FoundDecl, 2633 Args, NumArgs, CandidateSet); 2634 } 2635 } 2636 2637 SourceLocation DeclLoc = Kind.getLocation(); 2638 2639 // Perform overload resolution. If it fails, return the failed result. 2640 OverloadCandidateSet::iterator Best; 2641 if (OverloadingResult Result 2642 = S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2643 Sequence.SetOverloadFailure( 2644 InitializationSequence::FK_ConstructorOverloadFailed, 2645 Result); 2646 return; 2647 } 2648 2649 // C++0x [dcl.init]p6: 2650 // If a program calls for the default initialization of an object 2651 // of a const-qualified type T, T shall be a class type with a 2652 // user-provided default constructor. 2653 if (Kind.getKind() == InitializationKind::IK_Default && 2654 Entity.getType().isConstQualified() && 2655 cast<CXXConstructorDecl>(Best->Function)->isImplicit()) { 2656 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst); 2657 return; 2658 } 2659 2660 // Add the constructor initialization step. Any cv-qualification conversion is 2661 // subsumed by the initialization. 2662 Sequence.AddConstructorInitializationStep( 2663 cast<CXXConstructorDecl>(Best->Function), 2664 Best->FoundDecl.getAccess(), 2665 DestType); 2666} 2667 2668/// \brief Attempt value initialization (C++ [dcl.init]p7). 2669static void TryValueInitialization(Sema &S, 2670 const InitializedEntity &Entity, 2671 const InitializationKind &Kind, 2672 InitializationSequence &Sequence) { 2673 // C++ [dcl.init]p5: 2674 // 2675 // To value-initialize an object of type T means: 2676 QualType T = Entity.getType(); 2677 2678 // -- if T is an array type, then each element is value-initialized; 2679 while (const ArrayType *AT = S.Context.getAsArrayType(T)) 2680 T = AT->getElementType(); 2681 2682 if (const RecordType *RT = T->getAs<RecordType>()) { 2683 if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 2684 // -- if T is a class type (clause 9) with a user-declared 2685 // constructor (12.1), then the default constructor for T is 2686 // called (and the initialization is ill-formed if T has no 2687 // accessible default constructor); 2688 // 2689 // FIXME: we really want to refer to a single subobject of the array, 2690 // but Entity doesn't have a way to capture that (yet). 2691 if (ClassDecl->hasUserDeclaredConstructor()) 2692 return TryConstructorInitialization(S, Entity, Kind, 0, 0, T, Sequence); 2693 2694 // -- if T is a (possibly cv-qualified) non-union class type 2695 // without a user-provided constructor, then the object is 2696 // zero-initialized and, if T’s implicitly-declared default 2697 // constructor is non-trivial, that constructor is called. 2698 if ((ClassDecl->getTagKind() == TagDecl::TK_class || 2699 ClassDecl->getTagKind() == TagDecl::TK_struct) && 2700 !ClassDecl->hasTrivialConstructor()) { 2701 Sequence.AddZeroInitializationStep(Entity.getType()); 2702 return TryConstructorInitialization(S, Entity, Kind, 0, 0, T, Sequence); 2703 } 2704 } 2705 } 2706 2707 Sequence.AddZeroInitializationStep(Entity.getType()); 2708 Sequence.setSequenceKind(InitializationSequence::ZeroInitialization); 2709} 2710 2711/// \brief Attempt default initialization (C++ [dcl.init]p6). 2712static void TryDefaultInitialization(Sema &S, 2713 const InitializedEntity &Entity, 2714 const InitializationKind &Kind, 2715 InitializationSequence &Sequence) { 2716 assert(Kind.getKind() == InitializationKind::IK_Default); 2717 2718 // C++ [dcl.init]p6: 2719 // To default-initialize an object of type T means: 2720 // - if T is an array type, each element is default-initialized; 2721 QualType DestType = Entity.getType(); 2722 while (const ArrayType *Array = S.Context.getAsArrayType(DestType)) 2723 DestType = Array->getElementType(); 2724 2725 // - if T is a (possibly cv-qualified) class type (Clause 9), the default 2726 // constructor for T is called (and the initialization is ill-formed if 2727 // T has no accessible default constructor); 2728 if (DestType->isRecordType() && S.getLangOptions().CPlusPlus) { 2729 return TryConstructorInitialization(S, Entity, Kind, 0, 0, DestType, 2730 Sequence); 2731 } 2732 2733 // - otherwise, no initialization is performed. 2734 Sequence.setSequenceKind(InitializationSequence::NoInitialization); 2735 2736 // If a program calls for the default initialization of an object of 2737 // a const-qualified type T, T shall be a class type with a user-provided 2738 // default constructor. 2739 if (DestType.isConstQualified() && S.getLangOptions().CPlusPlus) 2740 Sequence.SetFailed(InitializationSequence::FK_DefaultInitOfConst); 2741} 2742 2743/// \brief Attempt a user-defined conversion between two types (C++ [dcl.init]), 2744/// which enumerates all conversion functions and performs overload resolution 2745/// to select the best. 2746static void TryUserDefinedConversion(Sema &S, 2747 const InitializedEntity &Entity, 2748 const InitializationKind &Kind, 2749 Expr *Initializer, 2750 InitializationSequence &Sequence) { 2751 Sequence.setSequenceKind(InitializationSequence::UserDefinedConversion); 2752 2753 QualType DestType = Entity.getType(); 2754 assert(!DestType->isReferenceType() && "References are handled elsewhere"); 2755 QualType SourceType = Initializer->getType(); 2756 assert((DestType->isRecordType() || SourceType->isRecordType()) && 2757 "Must have a class type to perform a user-defined conversion"); 2758 2759 // Build the candidate set directly in the initialization sequence 2760 // structure, so that it will persist if we fail. 2761 OverloadCandidateSet &CandidateSet = Sequence.getFailedCandidateSet(); 2762 CandidateSet.clear(); 2763 2764 // Determine whether we are allowed to call explicit constructors or 2765 // explicit conversion operators. 2766 bool AllowExplicit = Kind.getKind() == InitializationKind::IK_Direct; 2767 2768 if (const RecordType *DestRecordType = DestType->getAs<RecordType>()) { 2769 // The type we're converting to is a class type. Enumerate its constructors 2770 // to see if there is a suitable conversion. 2771 CXXRecordDecl *DestRecordDecl 2772 = cast<CXXRecordDecl>(DestRecordType->getDecl()); 2773 2774 DeclarationName ConstructorName 2775 = S.Context.DeclarationNames.getCXXConstructorName( 2776 S.Context.getCanonicalType(DestType).getUnqualifiedType()); 2777 DeclContext::lookup_iterator Con, ConEnd; 2778 for (llvm::tie(Con, ConEnd) = DestRecordDecl->lookup(ConstructorName); 2779 Con != ConEnd; ++Con) { 2780 NamedDecl *D = *Con; 2781 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2782 2783 // Find the constructor (which may be a template). 2784 CXXConstructorDecl *Constructor = 0; 2785 FunctionTemplateDecl *ConstructorTmpl 2786 = dyn_cast<FunctionTemplateDecl>(D); 2787 if (ConstructorTmpl) 2788 Constructor = cast<CXXConstructorDecl>( 2789 ConstructorTmpl->getTemplatedDecl()); 2790 else 2791 Constructor = cast<CXXConstructorDecl>(D); 2792 2793 if (!Constructor->isInvalidDecl() && 2794 Constructor->isConvertingConstructor(AllowExplicit)) { 2795 if (ConstructorTmpl) 2796 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2797 /*ExplicitArgs*/ 0, 2798 &Initializer, 1, CandidateSet); 2799 else 2800 S.AddOverloadCandidate(Constructor, FoundDecl, 2801 &Initializer, 1, CandidateSet); 2802 } 2803 } 2804 } 2805 2806 SourceLocation DeclLoc = Initializer->getLocStart(); 2807 2808 if (const RecordType *SourceRecordType = SourceType->getAs<RecordType>()) { 2809 // The type we're converting from is a class type, enumerate its conversion 2810 // functions. 2811 2812 // We can only enumerate the conversion functions for a complete type; if 2813 // the type isn't complete, simply skip this step. 2814 if (!S.RequireCompleteType(DeclLoc, SourceType, 0)) { 2815 CXXRecordDecl *SourceRecordDecl 2816 = cast<CXXRecordDecl>(SourceRecordType->getDecl()); 2817 2818 const UnresolvedSetImpl *Conversions 2819 = SourceRecordDecl->getVisibleConversionFunctions(); 2820 for (UnresolvedSetImpl::const_iterator I = Conversions->begin(), 2821 E = Conversions->end(); 2822 I != E; ++I) { 2823 NamedDecl *D = *I; 2824 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2825 if (isa<UsingShadowDecl>(D)) 2826 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2827 2828 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D); 2829 CXXConversionDecl *Conv; 2830 if (ConvTemplate) 2831 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2832 else 2833 Conv = cast<CXXConversionDecl>(D); 2834 2835 if (AllowExplicit || !Conv->isExplicit()) { 2836 if (ConvTemplate) 2837 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), 2838 ActingDC, Initializer, DestType, 2839 CandidateSet); 2840 else 2841 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, 2842 Initializer, DestType, CandidateSet); 2843 } 2844 } 2845 } 2846 } 2847 2848 // Perform overload resolution. If it fails, return the failed result. 2849 OverloadCandidateSet::iterator Best; 2850 if (OverloadingResult Result 2851 = S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2852 Sequence.SetOverloadFailure( 2853 InitializationSequence::FK_UserConversionOverloadFailed, 2854 Result); 2855 return; 2856 } 2857 2858 FunctionDecl *Function = Best->Function; 2859 2860 if (isa<CXXConstructorDecl>(Function)) { 2861 // Add the user-defined conversion step. Any cv-qualification conversion is 2862 // subsumed by the initialization. 2863 Sequence.AddUserConversionStep(Function, Best->FoundDecl, DestType); 2864 return; 2865 } 2866 2867 // Add the user-defined conversion step that calls the conversion function. 2868 QualType ConvType = Function->getResultType().getNonReferenceType(); 2869 if (ConvType->getAs<RecordType>()) { 2870 // If we're converting to a class type, there may be an copy if 2871 // the resulting temporary object (possible to create an object of 2872 // a base class type). That copy is not a separate conversion, so 2873 // we just make a note of the actual destination type (possibly a 2874 // base class of the type returned by the conversion function) and 2875 // let the user-defined conversion step handle the conversion. 2876 Sequence.AddUserConversionStep(Function, Best->FoundDecl, DestType); 2877 return; 2878 } 2879 2880 Sequence.AddUserConversionStep(Function, Best->FoundDecl, ConvType); 2881 2882 // If the conversion following the call to the conversion function 2883 // is interesting, add it as a separate step. 2884 if (Best->FinalConversion.First || Best->FinalConversion.Second || 2885 Best->FinalConversion.Third) { 2886 ImplicitConversionSequence ICS; 2887 ICS.setStandard(); 2888 ICS.Standard = Best->FinalConversion; 2889 Sequence.AddConversionSequenceStep(ICS, DestType); 2890 } 2891} 2892 2893/// \brief Attempt an implicit conversion (C++ [conv]) converting from one 2894/// non-class type to another. 2895static void TryImplicitConversion(Sema &S, 2896 const InitializedEntity &Entity, 2897 const InitializationKind &Kind, 2898 Expr *Initializer, 2899 InitializationSequence &Sequence) { 2900 ImplicitConversionSequence ICS 2901 = S.TryImplicitConversion(Initializer, Entity.getType(), 2902 /*SuppressUserConversions=*/true, 2903 /*AllowExplicit=*/false, 2904 /*InOverloadResolution=*/false); 2905 2906 if (ICS.isBad()) { 2907 Sequence.SetFailed(InitializationSequence::FK_ConversionFailed); 2908 return; 2909 } 2910 2911 Sequence.AddConversionSequenceStep(ICS, Entity.getType()); 2912} 2913 2914InitializationSequence::InitializationSequence(Sema &S, 2915 const InitializedEntity &Entity, 2916 const InitializationKind &Kind, 2917 Expr **Args, 2918 unsigned NumArgs) 2919 : FailedCandidateSet(Kind.getLocation()) { 2920 ASTContext &Context = S.Context; 2921 2922 // C++0x [dcl.init]p16: 2923 // The semantics of initializers are as follows. The destination type is 2924 // the type of the object or reference being initialized and the source 2925 // type is the type of the initializer expression. The source type is not 2926 // defined when the initializer is a braced-init-list or when it is a 2927 // parenthesized list of expressions. 2928 QualType DestType = Entity.getType(); 2929 2930 if (DestType->isDependentType() || 2931 Expr::hasAnyTypeDependentArguments(Args, NumArgs)) { 2932 SequenceKind = DependentSequence; 2933 return; 2934 } 2935 2936 QualType SourceType; 2937 Expr *Initializer = 0; 2938 if (NumArgs == 1) { 2939 Initializer = Args[0]; 2940 if (!isa<InitListExpr>(Initializer)) 2941 SourceType = Initializer->getType(); 2942 } 2943 2944 // - If the initializer is a braced-init-list, the object is 2945 // list-initialized (8.5.4). 2946 if (InitListExpr *InitList = dyn_cast_or_null<InitListExpr>(Initializer)) { 2947 TryListInitialization(S, Entity, Kind, InitList, *this); 2948 return; 2949 } 2950 2951 // - If the destination type is a reference type, see 8.5.3. 2952 if (DestType->isReferenceType()) { 2953 // C++0x [dcl.init.ref]p1: 2954 // A variable declared to be a T& or T&&, that is, "reference to type T" 2955 // (8.3.2), shall be initialized by an object, or function, of type T or 2956 // by an object that can be converted into a T. 2957 // (Therefore, multiple arguments are not permitted.) 2958 if (NumArgs != 1) 2959 SetFailed(FK_TooManyInitsForReference); 2960 else 2961 TryReferenceInitialization(S, Entity, Kind, Args[0], *this); 2962 return; 2963 } 2964 2965 // - If the destination type is an array of characters, an array of 2966 // char16_t, an array of char32_t, or an array of wchar_t, and the 2967 // initializer is a string literal, see 8.5.2. 2968 if (Initializer && IsStringInit(Initializer, DestType, Context)) { 2969 TryStringLiteralInitialization(S, Entity, Kind, Initializer, *this); 2970 return; 2971 } 2972 2973 // - If the initializer is (), the object is value-initialized. 2974 if (Kind.getKind() == InitializationKind::IK_Value || 2975 (Kind.getKind() == InitializationKind::IK_Direct && NumArgs == 0)) { 2976 TryValueInitialization(S, Entity, Kind, *this); 2977 return; 2978 } 2979 2980 // Handle default initialization. 2981 if (Kind.getKind() == InitializationKind::IK_Default){ 2982 TryDefaultInitialization(S, Entity, Kind, *this); 2983 return; 2984 } 2985 2986 // - Otherwise, if the destination type is an array, the program is 2987 // ill-formed. 2988 if (const ArrayType *AT = Context.getAsArrayType(DestType)) { 2989 if (AT->getElementType()->isAnyCharacterType()) 2990 SetFailed(FK_ArrayNeedsInitListOrStringLiteral); 2991 else 2992 SetFailed(FK_ArrayNeedsInitList); 2993 2994 return; 2995 } 2996 2997 // Handle initialization in C 2998 if (!S.getLangOptions().CPlusPlus) { 2999 setSequenceKind(CAssignment); 3000 AddCAssignmentStep(DestType); 3001 return; 3002 } 3003 3004 // - If the destination type is a (possibly cv-qualified) class type: 3005 if (DestType->isRecordType()) { 3006 // - If the initialization is direct-initialization, or if it is 3007 // copy-initialization where the cv-unqualified version of the 3008 // source type is the same class as, or a derived class of, the 3009 // class of the destination, constructors are considered. [...] 3010 if (Kind.getKind() == InitializationKind::IK_Direct || 3011 (Kind.getKind() == InitializationKind::IK_Copy && 3012 (Context.hasSameUnqualifiedType(SourceType, DestType) || 3013 S.IsDerivedFrom(SourceType, DestType)))) 3014 TryConstructorInitialization(S, Entity, Kind, Args, NumArgs, 3015 Entity.getType(), *this); 3016 // - Otherwise (i.e., for the remaining copy-initialization cases), 3017 // user-defined conversion sequences that can convert from the source 3018 // type to the destination type or (when a conversion function is 3019 // used) to a derived class thereof are enumerated as described in 3020 // 13.3.1.4, and the best one is chosen through overload resolution 3021 // (13.3). 3022 else 3023 TryUserDefinedConversion(S, Entity, Kind, Initializer, *this); 3024 return; 3025 } 3026 3027 if (NumArgs > 1) { 3028 SetFailed(FK_TooManyInitsForScalar); 3029 return; 3030 } 3031 assert(NumArgs == 1 && "Zero-argument case handled above"); 3032 3033 // - Otherwise, if the source type is a (possibly cv-qualified) class 3034 // type, conversion functions are considered. 3035 if (!SourceType.isNull() && SourceType->isRecordType()) { 3036 TryUserDefinedConversion(S, Entity, Kind, Initializer, *this); 3037 return; 3038 } 3039 3040 // - Otherwise, the initial value of the object being initialized is the 3041 // (possibly converted) value of the initializer expression. Standard 3042 // conversions (Clause 4) will be used, if necessary, to convert the 3043 // initializer expression to the cv-unqualified version of the 3044 // destination type; no user-defined conversions are considered. 3045 setSequenceKind(StandardConversion); 3046 TryImplicitConversion(S, Entity, Kind, Initializer, *this); 3047} 3048 3049InitializationSequence::~InitializationSequence() { 3050 for (llvm::SmallVectorImpl<Step>::iterator Step = Steps.begin(), 3051 StepEnd = Steps.end(); 3052 Step != StepEnd; ++Step) 3053 Step->Destroy(); 3054} 3055 3056//===----------------------------------------------------------------------===// 3057// Perform initialization 3058//===----------------------------------------------------------------------===// 3059static Sema::AssignmentAction 3060getAssignmentAction(const InitializedEntity &Entity) { 3061 switch(Entity.getKind()) { 3062 case InitializedEntity::EK_Variable: 3063 case InitializedEntity::EK_New: 3064 return Sema::AA_Initializing; 3065 3066 case InitializedEntity::EK_Parameter: 3067 // FIXME: Can we tell when we're sending vs. passing? 3068 return Sema::AA_Passing; 3069 3070 case InitializedEntity::EK_Result: 3071 return Sema::AA_Returning; 3072 3073 case InitializedEntity::EK_Exception: 3074 case InitializedEntity::EK_Base: 3075 llvm_unreachable("No assignment action for C++-specific initialization"); 3076 break; 3077 3078 case InitializedEntity::EK_Temporary: 3079 // FIXME: Can we tell apart casting vs. converting? 3080 return Sema::AA_Casting; 3081 3082 case InitializedEntity::EK_Member: 3083 case InitializedEntity::EK_ArrayElement: 3084 case InitializedEntity::EK_VectorElement: 3085 return Sema::AA_Initializing; 3086 } 3087 3088 return Sema::AA_Converting; 3089} 3090 3091static bool shouldBindAsTemporary(const InitializedEntity &Entity) { 3092 switch (Entity.getKind()) { 3093 case InitializedEntity::EK_ArrayElement: 3094 case InitializedEntity::EK_Member: 3095 case InitializedEntity::EK_Result: 3096 case InitializedEntity::EK_New: 3097 case InitializedEntity::EK_Variable: 3098 case InitializedEntity::EK_Base: 3099 case InitializedEntity::EK_VectorElement: 3100 case InitializedEntity::EK_Exception: 3101 return false; 3102 3103 case InitializedEntity::EK_Parameter: 3104 case InitializedEntity::EK_Temporary: 3105 return true; 3106 } 3107 3108 llvm_unreachable("missed an InitializedEntity kind?"); 3109} 3110 3111static Sema::OwningExprResult CopyObject(Sema &S, 3112 const InitializedEntity &Entity, 3113 const InitializationKind &Kind, 3114 Sema::OwningExprResult CurInit) { 3115 // Determine which class type we're copying to. 3116 Expr *CurInitExpr = (Expr *)CurInit.get(); 3117 CXXRecordDecl *Class = 0; 3118 if (const RecordType *Record 3119 = Entity.getType().getNonReferenceType()->getAs<RecordType>()) 3120 Class = cast<CXXRecordDecl>(Record->getDecl()); 3121 if (!Class) 3122 return move(CurInit); 3123 3124 // C++0x [class.copy]p34: 3125 // When certain criteria are met, an implementation is allowed to 3126 // omit the copy/move construction of a class object, even if the 3127 // copy/move constructor and/or destructor for the object have 3128 // side effects. [...] 3129 // - when a temporary class object that has not been bound to a 3130 // reference (12.2) would be copied/moved to a class object 3131 // with the same cv-unqualified type, the copy/move operation 3132 // can be omitted by constructing the temporary object 3133 // directly into the target of the omitted copy/move 3134 // 3135 // Note that the other three bullets are handled elsewhere. Copy 3136 // elision for return statements and throw expressions are (FIXME: 3137 // not yet) handled as part of constructor initialization, while 3138 // copy elision for exception handlers is handled by the run-time. 3139 bool Elidable = CurInitExpr->isTemporaryObject() && 3140 S.Context.hasSameUnqualifiedType(Entity.getType(), CurInitExpr->getType()); 3141 SourceLocation Loc; 3142 switch (Entity.getKind()) { 3143 case InitializedEntity::EK_Result: 3144 Loc = Entity.getReturnLoc(); 3145 break; 3146 3147 case InitializedEntity::EK_Exception: 3148 Loc = Entity.getThrowLoc(); 3149 break; 3150 3151 case InitializedEntity::EK_Variable: 3152 Loc = Entity.getDecl()->getLocation(); 3153 break; 3154 3155 case InitializedEntity::EK_ArrayElement: 3156 case InitializedEntity::EK_Member: 3157 case InitializedEntity::EK_Parameter: 3158 case InitializedEntity::EK_Temporary: 3159 case InitializedEntity::EK_New: 3160 case InitializedEntity::EK_Base: 3161 case InitializedEntity::EK_VectorElement: 3162 Loc = CurInitExpr->getLocStart(); 3163 break; 3164 } 3165 3166 // Perform overload resolution using the class's copy constructors. 3167 DeclarationName ConstructorName 3168 = S.Context.DeclarationNames.getCXXConstructorName( 3169 S.Context.getCanonicalType(S.Context.getTypeDeclType(Class))); 3170 DeclContext::lookup_iterator Con, ConEnd; 3171 OverloadCandidateSet CandidateSet(Loc); 3172 for (llvm::tie(Con, ConEnd) = Class->lookup(ConstructorName); 3173 Con != ConEnd; ++Con) { 3174 // Only consider copy constructors. 3175 CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(*Con); 3176 if (!Constructor || Constructor->isInvalidDecl() || 3177 !Constructor->isCopyConstructor()) 3178 continue; 3179 3180 DeclAccessPair FoundDecl 3181 = DeclAccessPair::make(Constructor, Constructor->getAccess()); 3182 S.AddOverloadCandidate(Constructor, FoundDecl, 3183 &CurInitExpr, 1, CandidateSet); 3184 } 3185 3186 OverloadCandidateSet::iterator Best; 3187 switch (S.BestViableFunction(CandidateSet, Loc, Best)) { 3188 case OR_Success: 3189 break; 3190 3191 case OR_No_Viable_Function: 3192 S.Diag(Loc, diag::err_temp_copy_no_viable) 3193 << (int)Entity.getKind() << CurInitExpr->getType() 3194 << CurInitExpr->getSourceRange(); 3195 S.PrintOverloadCandidates(CandidateSet, Sema::OCD_AllCandidates, 3196 &CurInitExpr, 1); 3197 return S.ExprError(); 3198 3199 case OR_Ambiguous: 3200 S.Diag(Loc, diag::err_temp_copy_ambiguous) 3201 << (int)Entity.getKind() << CurInitExpr->getType() 3202 << CurInitExpr->getSourceRange(); 3203 S.PrintOverloadCandidates(CandidateSet, Sema::OCD_ViableCandidates, 3204 &CurInitExpr, 1); 3205 return S.ExprError(); 3206 3207 case OR_Deleted: 3208 S.Diag(Loc, diag::err_temp_copy_deleted) 3209 << (int)Entity.getKind() << CurInitExpr->getType() 3210 << CurInitExpr->getSourceRange(); 3211 S.Diag(Best->Function->getLocation(), diag::note_unavailable_here) 3212 << Best->Function->isDeleted(); 3213 return S.ExprError(); 3214 } 3215 3216 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function); 3217 ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(S); 3218 CurInit.release(); // Ownership transferred into MultiExprArg, below. 3219 3220 // Determine the arguments required to actually perform the 3221 // constructor call (we might have derived-to-base conversions). 3222 if (S.CompleteConstructorCall(Constructor, 3223 Sema::MultiExprArg(S, 3224 (void **)&CurInitExpr, 3225 1), 3226 Loc, ConstructorArgs)) 3227 return S.ExprError(); 3228 3229 S.CheckConstructorAccess(Loc, Constructor, 3230 Best->FoundDecl.getAccess()); 3231 3232 return S.BuildCXXConstructExpr(Loc, Entity.getType().getNonReferenceType(), 3233 Constructor, 3234 Elidable, 3235 move_arg(ConstructorArgs)); 3236} 3237 3238Action::OwningExprResult 3239InitializationSequence::Perform(Sema &S, 3240 const InitializedEntity &Entity, 3241 const InitializationKind &Kind, 3242 Action::MultiExprArg Args, 3243 QualType *ResultType) { 3244 if (SequenceKind == FailedSequence) { 3245 unsigned NumArgs = Args.size(); 3246 Diagnose(S, Entity, Kind, (Expr **)Args.release(), NumArgs); 3247 return S.ExprError(); 3248 } 3249 3250 if (SequenceKind == DependentSequence) { 3251 // If the declaration is a non-dependent, incomplete array type 3252 // that has an initializer, then its type will be completed once 3253 // the initializer is instantiated. 3254 if (ResultType && !Entity.getType()->isDependentType() && 3255 Args.size() == 1) { 3256 QualType DeclType = Entity.getType(); 3257 if (const IncompleteArrayType *ArrayT 3258 = S.Context.getAsIncompleteArrayType(DeclType)) { 3259 // FIXME: We don't currently have the ability to accurately 3260 // compute the length of an initializer list without 3261 // performing full type-checking of the initializer list 3262 // (since we have to determine where braces are implicitly 3263 // introduced and such). So, we fall back to making the array 3264 // type a dependently-sized array type with no specified 3265 // bound. 3266 if (isa<InitListExpr>((Expr *)Args.get()[0])) { 3267 SourceRange Brackets; 3268 3269 // Scavange the location of the brackets from the entity, if we can. 3270 if (DeclaratorDecl *DD = Entity.getDecl()) { 3271 if (TypeSourceInfo *TInfo = DD->getTypeSourceInfo()) { 3272 TypeLoc TL = TInfo->getTypeLoc(); 3273 if (IncompleteArrayTypeLoc *ArrayLoc 3274 = dyn_cast<IncompleteArrayTypeLoc>(&TL)) 3275 Brackets = ArrayLoc->getBracketsRange(); 3276 } 3277 } 3278 3279 *ResultType 3280 = S.Context.getDependentSizedArrayType(ArrayT->getElementType(), 3281 /*NumElts=*/0, 3282 ArrayT->getSizeModifier(), 3283 ArrayT->getIndexTypeCVRQualifiers(), 3284 Brackets); 3285 } 3286 3287 } 3288 } 3289 3290 if (Kind.getKind() == InitializationKind::IK_Copy || Kind.isExplicitCast()) 3291 return Sema::OwningExprResult(S, Args.release()[0]); 3292 3293 if (Args.size() == 0) 3294 return S.Owned((Expr *)0); 3295 3296 unsigned NumArgs = Args.size(); 3297 return S.Owned(new (S.Context) ParenListExpr(S.Context, 3298 SourceLocation(), 3299 (Expr **)Args.release(), 3300 NumArgs, 3301 SourceLocation())); 3302 } 3303 3304 if (SequenceKind == NoInitialization) 3305 return S.Owned((Expr *)0); 3306 3307 QualType DestType = Entity.getType().getNonReferenceType(); 3308 // FIXME: Ugly hack around the fact that Entity.getType() is not 3309 // the same as Entity.getDecl()->getType() in cases involving type merging, 3310 // and we want latter when it makes sense. 3311 if (ResultType) 3312 *ResultType = Entity.getDecl() ? Entity.getDecl()->getType() : 3313 Entity.getType(); 3314 3315 Sema::OwningExprResult CurInit = S.Owned((Expr *)0); 3316 3317 assert(!Steps.empty() && "Cannot have an empty initialization sequence"); 3318 3319 // For initialization steps that start with a single initializer, 3320 // grab the only argument out the Args and place it into the "current" 3321 // initializer. 3322 switch (Steps.front().Kind) { 3323 case SK_ResolveAddressOfOverloadedFunction: 3324 case SK_CastDerivedToBaseRValue: 3325 case SK_CastDerivedToBaseLValue: 3326 case SK_BindReference: 3327 case SK_BindReferenceToTemporary: 3328 case SK_UserConversion: 3329 case SK_QualificationConversionLValue: 3330 case SK_QualificationConversionRValue: 3331 case SK_ConversionSequence: 3332 case SK_ListInitialization: 3333 case SK_CAssignment: 3334 case SK_StringInit: 3335 assert(Args.size() == 1); 3336 CurInit = Sema::OwningExprResult(S, ((Expr **)(Args.get()))[0]->Retain()); 3337 if (CurInit.isInvalid()) 3338 return S.ExprError(); 3339 break; 3340 3341 case SK_ConstructorInitialization: 3342 case SK_ZeroInitialization: 3343 break; 3344 } 3345 3346 // Walk through the computed steps for the initialization sequence, 3347 // performing the specified conversions along the way. 3348 bool ConstructorInitRequiresZeroInit = false; 3349 for (step_iterator Step = step_begin(), StepEnd = step_end(); 3350 Step != StepEnd; ++Step) { 3351 if (CurInit.isInvalid()) 3352 return S.ExprError(); 3353 3354 Expr *CurInitExpr = (Expr *)CurInit.get(); 3355 QualType SourceType = CurInitExpr? CurInitExpr->getType() : QualType(); 3356 3357 switch (Step->Kind) { 3358 case SK_ResolveAddressOfOverloadedFunction: 3359 // Overload resolution determined which function invoke; update the 3360 // initializer to reflect that choice. 3361 S.CheckAddressOfMemberAccess(CurInitExpr, Step->Function.FoundDecl); 3362 CurInit = S.FixOverloadedFunctionReference(move(CurInit), 3363 Step->Function.FoundDecl, 3364 Step->Function.Function); 3365 break; 3366 3367 case SK_CastDerivedToBaseRValue: 3368 case SK_CastDerivedToBaseLValue: { 3369 // We have a derived-to-base cast that produces either an rvalue or an 3370 // lvalue. Perform that cast. 3371 3372 // Casts to inaccessible base classes are allowed with C-style casts. 3373 bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast(); 3374 if (S.CheckDerivedToBaseConversion(SourceType, Step->Type, 3375 CurInitExpr->getLocStart(), 3376 CurInitExpr->getSourceRange(), 3377 IgnoreBaseAccess)) 3378 return S.ExprError(); 3379 3380 CurInit = S.Owned(new (S.Context) ImplicitCastExpr(Step->Type, 3381 CastExpr::CK_DerivedToBase, 3382 (Expr*)CurInit.release(), 3383 Step->Kind == SK_CastDerivedToBaseLValue)); 3384 break; 3385 } 3386 3387 case SK_BindReference: 3388 if (FieldDecl *BitField = CurInitExpr->getBitField()) { 3389 // References cannot bind to bit fields (C++ [dcl.init.ref]p5). 3390 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield) 3391 << Entity.getType().isVolatileQualified() 3392 << BitField->getDeclName() 3393 << CurInitExpr->getSourceRange(); 3394 S.Diag(BitField->getLocation(), diag::note_bitfield_decl); 3395 return S.ExprError(); 3396 } 3397 3398 if (CurInitExpr->refersToVectorElement()) { 3399 // References cannot bind to vector elements. 3400 S.Diag(Kind.getLocation(), diag::err_reference_bind_to_vector_element) 3401 << Entity.getType().isVolatileQualified() 3402 << CurInitExpr->getSourceRange(); 3403 return S.ExprError(); 3404 } 3405 3406 // Reference binding does not have any corresponding ASTs. 3407 3408 // Check exception specifications 3409 if (S.CheckExceptionSpecCompatibility(CurInitExpr, DestType)) 3410 return S.ExprError(); 3411 3412 break; 3413 3414 case SK_BindReferenceToTemporary: 3415 // Reference binding does not have any corresponding ASTs. 3416 3417 // Check exception specifications 3418 if (S.CheckExceptionSpecCompatibility(CurInitExpr, DestType)) 3419 return S.ExprError(); 3420 3421 break; 3422 3423 case SK_UserConversion: { 3424 // We have a user-defined conversion that invokes either a constructor 3425 // or a conversion function. 3426 CastExpr::CastKind CastKind = CastExpr::CK_Unknown; 3427 bool IsCopy = false; 3428 FunctionDecl *Fn = Step->Function.Function; 3429 DeclAccessPair FoundFn = Step->Function.FoundDecl; 3430 bool IsLvalue = false; 3431 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Fn)) { 3432 // Build a call to the selected constructor. 3433 ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(S); 3434 SourceLocation Loc = CurInitExpr->getLocStart(); 3435 CurInit.release(); // Ownership transferred into MultiExprArg, below. 3436 3437 // Determine the arguments required to actually perform the constructor 3438 // call. 3439 if (S.CompleteConstructorCall(Constructor, 3440 Sema::MultiExprArg(S, 3441 (void **)&CurInitExpr, 3442 1), 3443 Loc, ConstructorArgs)) 3444 return S.ExprError(); 3445 3446 // Build the an expression that constructs a temporary. 3447 CurInit = S.BuildCXXConstructExpr(Loc, Step->Type, Constructor, 3448 move_arg(ConstructorArgs)); 3449 if (CurInit.isInvalid()) 3450 return S.ExprError(); 3451 3452 S.CheckConstructorAccess(Kind.getLocation(), Constructor, 3453 FoundFn.getAccess()); 3454 3455 CastKind = CastExpr::CK_ConstructorConversion; 3456 QualType Class = S.Context.getTypeDeclType(Constructor->getParent()); 3457 if (S.Context.hasSameUnqualifiedType(SourceType, Class) || 3458 S.IsDerivedFrom(SourceType, Class)) 3459 IsCopy = true; 3460 } else { 3461 // Build a call to the conversion function. 3462 CXXConversionDecl *Conversion = cast<CXXConversionDecl>(Fn); 3463 IsLvalue = Conversion->getResultType()->isLValueReferenceType(); 3464 S.CheckMemberOperatorAccess(Kind.getLocation(), CurInitExpr, 0, 3465 FoundFn); 3466 3467 // FIXME: Should we move this initialization into a separate 3468 // derived-to-base conversion? I believe the answer is "no", because 3469 // we don't want to turn off access control here for c-style casts. 3470 if (S.PerformObjectArgumentInitialization(CurInitExpr, /*Qualifier=*/0, 3471 FoundFn, Conversion)) 3472 return S.ExprError(); 3473 3474 // Do a little dance to make sure that CurInit has the proper 3475 // pointer. 3476 CurInit.release(); 3477 3478 // Build the actual call to the conversion function. 3479 CurInit = S.Owned(S.BuildCXXMemberCallExpr(CurInitExpr, FoundFn, 3480 Conversion)); 3481 if (CurInit.isInvalid() || !CurInit.get()) 3482 return S.ExprError(); 3483 3484 CastKind = CastExpr::CK_UserDefinedConversion; 3485 } 3486 3487 bool RequiresCopy = !IsCopy && 3488 getKind() != InitializationSequence::ReferenceBinding; 3489 if (RequiresCopy || shouldBindAsTemporary(Entity)) 3490 CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>()); 3491 3492 CurInitExpr = CurInit.takeAs<Expr>(); 3493 CurInit = S.Owned(new (S.Context) ImplicitCastExpr(CurInitExpr->getType(), 3494 CastKind, 3495 CurInitExpr, 3496 IsLvalue)); 3497 3498 if (RequiresCopy) 3499 CurInit = CopyObject(S, Entity, Kind, move(CurInit)); 3500 break; 3501 } 3502 3503 case SK_QualificationConversionLValue: 3504 case SK_QualificationConversionRValue: 3505 // Perform a qualification conversion; these can never go wrong. 3506 S.ImpCastExprToType(CurInitExpr, Step->Type, 3507 CastExpr::CK_NoOp, 3508 Step->Kind == SK_QualificationConversionLValue); 3509 CurInit.release(); 3510 CurInit = S.Owned(CurInitExpr); 3511 break; 3512 3513 case SK_ConversionSequence: { 3514 bool IgnoreBaseAccess = Kind.isCStyleOrFunctionalCast(); 3515 3516 if (S.PerformImplicitConversion(CurInitExpr, Step->Type, *Step->ICS, 3517 Sema::AA_Converting, IgnoreBaseAccess)) 3518 return S.ExprError(); 3519 3520 CurInit.release(); 3521 CurInit = S.Owned(CurInitExpr); 3522 break; 3523 } 3524 3525 case SK_ListInitialization: { 3526 InitListExpr *InitList = cast<InitListExpr>(CurInitExpr); 3527 QualType Ty = Step->Type; 3528 if (S.CheckInitList(Entity, InitList, ResultType? *ResultType : Ty)) 3529 return S.ExprError(); 3530 3531 CurInit.release(); 3532 CurInit = S.Owned(InitList); 3533 break; 3534 } 3535 3536 case SK_ConstructorInitialization: { 3537 unsigned NumArgs = Args.size(); 3538 CXXConstructorDecl *Constructor 3539 = cast<CXXConstructorDecl>(Step->Function.Function); 3540 3541 // Build a call to the selected constructor. 3542 ASTOwningVector<&ActionBase::DeleteExpr> ConstructorArgs(S); 3543 SourceLocation Loc = Kind.getLocation(); 3544 3545 // Determine the arguments required to actually perform the constructor 3546 // call. 3547 if (S.CompleteConstructorCall(Constructor, move(Args), 3548 Loc, ConstructorArgs)) 3549 return S.ExprError(); 3550 3551 // Build the expression that constructs a temporary. 3552 if (Entity.getKind() == InitializedEntity::EK_Temporary && 3553 NumArgs != 1 && // FIXME: Hack to work around cast weirdness 3554 (Kind.getKind() == InitializationKind::IK_Direct || 3555 Kind.getKind() == InitializationKind::IK_Value)) { 3556 // An explicitly-constructed temporary, e.g., X(1, 2). 3557 unsigned NumExprs = ConstructorArgs.size(); 3558 Expr **Exprs = (Expr **)ConstructorArgs.take(); 3559 S.MarkDeclarationReferenced(Kind.getLocation(), Constructor); 3560 CurInit = S.Owned(new (S.Context) CXXTemporaryObjectExpr(S.Context, 3561 Constructor, 3562 Entity.getType(), 3563 Kind.getLocation(), 3564 Exprs, 3565 NumExprs, 3566 Kind.getParenRange().getEnd())); 3567 } else 3568 CurInit = S.BuildCXXConstructExpr(Loc, Entity.getType(), 3569 Constructor, 3570 move_arg(ConstructorArgs), 3571 ConstructorInitRequiresZeroInit, 3572 Entity.getKind() == InitializedEntity::EK_Base); 3573 if (CurInit.isInvalid()) 3574 return S.ExprError(); 3575 3576 // Only check access if all of that succeeded. 3577 S.CheckConstructorAccess(Loc, Constructor, 3578 Step->Function.FoundDecl.getAccess()); 3579 3580 if (shouldBindAsTemporary(Entity)) 3581 CurInit = S.MaybeBindToTemporary(CurInit.takeAs<Expr>()); 3582 3583 break; 3584 } 3585 3586 case SK_ZeroInitialization: { 3587 step_iterator NextStep = Step; 3588 ++NextStep; 3589 if (NextStep != StepEnd && 3590 NextStep->Kind == SK_ConstructorInitialization) { 3591 // The need for zero-initialization is recorded directly into 3592 // the call to the object's constructor within the next step. 3593 ConstructorInitRequiresZeroInit = true; 3594 } else if (Kind.getKind() == InitializationKind::IK_Value && 3595 S.getLangOptions().CPlusPlus && 3596 !Kind.isImplicitValueInit()) { 3597 CurInit = S.Owned(new (S.Context) CXXZeroInitValueExpr(Step->Type, 3598 Kind.getRange().getBegin(), 3599 Kind.getRange().getEnd())); 3600 } else { 3601 CurInit = S.Owned(new (S.Context) ImplicitValueInitExpr(Step->Type)); 3602 } 3603 break; 3604 } 3605 3606 case SK_CAssignment: { 3607 QualType SourceType = CurInitExpr->getType(); 3608 Sema::AssignConvertType ConvTy = 3609 S.CheckSingleAssignmentConstraints(Step->Type, CurInitExpr); 3610 3611 // If this is a call, allow conversion to a transparent union. 3612 if (ConvTy != Sema::Compatible && 3613 Entity.getKind() == InitializedEntity::EK_Parameter && 3614 S.CheckTransparentUnionArgumentConstraints(Step->Type, CurInitExpr) 3615 == Sema::Compatible) 3616 ConvTy = Sema::Compatible; 3617 3618 if (S.DiagnoseAssignmentResult(ConvTy, Kind.getLocation(), 3619 Step->Type, SourceType, 3620 CurInitExpr, getAssignmentAction(Entity))) 3621 return S.ExprError(); 3622 3623 CurInit.release(); 3624 CurInit = S.Owned(CurInitExpr); 3625 break; 3626 } 3627 3628 case SK_StringInit: { 3629 QualType Ty = Step->Type; 3630 CheckStringInit(CurInitExpr, ResultType ? *ResultType : Ty, S); 3631 break; 3632 } 3633 } 3634 } 3635 3636 return move(CurInit); 3637} 3638 3639//===----------------------------------------------------------------------===// 3640// Diagnose initialization failures 3641//===----------------------------------------------------------------------===// 3642bool InitializationSequence::Diagnose(Sema &S, 3643 const InitializedEntity &Entity, 3644 const InitializationKind &Kind, 3645 Expr **Args, unsigned NumArgs) { 3646 if (SequenceKind != FailedSequence) 3647 return false; 3648 3649 QualType DestType = Entity.getType(); 3650 switch (Failure) { 3651 case FK_TooManyInitsForReference: 3652 // FIXME: Customize for the initialized entity? 3653 if (NumArgs == 0) 3654 S.Diag(Kind.getLocation(), diag::err_reference_without_init) 3655 << DestType.getNonReferenceType(); 3656 else // FIXME: diagnostic below could be better! 3657 S.Diag(Kind.getLocation(), diag::err_reference_has_multiple_inits) 3658 << SourceRange(Args[0]->getLocStart(), Args[NumArgs - 1]->getLocEnd()); 3659 break; 3660 3661 case FK_ArrayNeedsInitList: 3662 case FK_ArrayNeedsInitListOrStringLiteral: 3663 S.Diag(Kind.getLocation(), diag::err_array_init_not_init_list) 3664 << (Failure == FK_ArrayNeedsInitListOrStringLiteral); 3665 break; 3666 3667 case FK_AddressOfOverloadFailed: { 3668 DeclAccessPair Found; 3669 S.ResolveAddressOfOverloadedFunction(Args[0], 3670 DestType.getNonReferenceType(), 3671 true, 3672 Found); 3673 break; 3674 } 3675 3676 case FK_ReferenceInitOverloadFailed: 3677 case FK_UserConversionOverloadFailed: 3678 switch (FailedOverloadResult) { 3679 case OR_Ambiguous: 3680 if (Failure == FK_UserConversionOverloadFailed) 3681 S.Diag(Kind.getLocation(), diag::err_typecheck_ambiguous_condition) 3682 << Args[0]->getType() << DestType 3683 << Args[0]->getSourceRange(); 3684 else 3685 S.Diag(Kind.getLocation(), diag::err_ref_init_ambiguous) 3686 << DestType << Args[0]->getType() 3687 << Args[0]->getSourceRange(); 3688 3689 S.PrintOverloadCandidates(FailedCandidateSet, Sema::OCD_ViableCandidates, 3690 Args, NumArgs); 3691 break; 3692 3693 case OR_No_Viable_Function: 3694 S.Diag(Kind.getLocation(), diag::err_typecheck_nonviable_condition) 3695 << Args[0]->getType() << DestType.getNonReferenceType() 3696 << Args[0]->getSourceRange(); 3697 S.PrintOverloadCandidates(FailedCandidateSet, Sema::OCD_AllCandidates, 3698 Args, NumArgs); 3699 break; 3700 3701 case OR_Deleted: { 3702 S.Diag(Kind.getLocation(), diag::err_typecheck_deleted_function) 3703 << Args[0]->getType() << DestType.getNonReferenceType() 3704 << Args[0]->getSourceRange(); 3705 OverloadCandidateSet::iterator Best; 3706 OverloadingResult Ovl = S.BestViableFunction(FailedCandidateSet, 3707 Kind.getLocation(), 3708 Best); 3709 if (Ovl == OR_Deleted) { 3710 S.Diag(Best->Function->getLocation(), diag::note_unavailable_here) 3711 << Best->Function->isDeleted(); 3712 } else { 3713 llvm_unreachable("Inconsistent overload resolution?"); 3714 } 3715 break; 3716 } 3717 3718 case OR_Success: 3719 llvm_unreachable("Conversion did not fail!"); 3720 break; 3721 } 3722 break; 3723 3724 case FK_NonConstLValueReferenceBindingToTemporary: 3725 case FK_NonConstLValueReferenceBindingToUnrelated: 3726 S.Diag(Kind.getLocation(), 3727 Failure == FK_NonConstLValueReferenceBindingToTemporary 3728 ? diag::err_lvalue_reference_bind_to_temporary 3729 : diag::err_lvalue_reference_bind_to_unrelated) 3730 << DestType.getNonReferenceType().isVolatileQualified() 3731 << DestType.getNonReferenceType() 3732 << Args[0]->getType() 3733 << Args[0]->getSourceRange(); 3734 break; 3735 3736 case FK_RValueReferenceBindingToLValue: 3737 S.Diag(Kind.getLocation(), diag::err_lvalue_to_rvalue_ref) 3738 << Args[0]->getSourceRange(); 3739 break; 3740 3741 case FK_ReferenceInitDropsQualifiers: 3742 S.Diag(Kind.getLocation(), diag::err_reference_bind_drops_quals) 3743 << DestType.getNonReferenceType() 3744 << Args[0]->getType() 3745 << Args[0]->getSourceRange(); 3746 break; 3747 3748 case FK_ReferenceInitFailed: 3749 S.Diag(Kind.getLocation(), diag::err_reference_bind_failed) 3750 << DestType.getNonReferenceType() 3751 << (Args[0]->isLvalue(S.Context) == Expr::LV_Valid) 3752 << Args[0]->getType() 3753 << Args[0]->getSourceRange(); 3754 break; 3755 3756 case FK_ConversionFailed: 3757 S.Diag(Kind.getLocation(), diag::err_init_conversion_failed) 3758 << (int)Entity.getKind() 3759 << DestType 3760 << (Args[0]->isLvalue(S.Context) == Expr::LV_Valid) 3761 << Args[0]->getType() 3762 << Args[0]->getSourceRange(); 3763 break; 3764 3765 case FK_TooManyInitsForScalar: { 3766 SourceRange R; 3767 3768 if (InitListExpr *InitList = dyn_cast<InitListExpr>(Args[0])) 3769 R = SourceRange(InitList->getInit(1)->getLocStart(), 3770 InitList->getLocEnd()); 3771 else 3772 R = SourceRange(Args[0]->getLocStart(), Args[NumArgs - 1]->getLocEnd()); 3773 3774 S.Diag(Kind.getLocation(), diag::err_excess_initializers) 3775 << /*scalar=*/2 << R; 3776 break; 3777 } 3778 3779 case FK_ReferenceBindingToInitList: 3780 S.Diag(Kind.getLocation(), diag::err_reference_bind_init_list) 3781 << DestType.getNonReferenceType() << Args[0]->getSourceRange(); 3782 break; 3783 3784 case FK_InitListBadDestinationType: 3785 S.Diag(Kind.getLocation(), diag::err_init_list_bad_dest_type) 3786 << (DestType->isRecordType()) << DestType << Args[0]->getSourceRange(); 3787 break; 3788 3789 case FK_ConstructorOverloadFailed: { 3790 SourceRange ArgsRange; 3791 if (NumArgs) 3792 ArgsRange = SourceRange(Args[0]->getLocStart(), 3793 Args[NumArgs - 1]->getLocEnd()); 3794 3795 // FIXME: Using "DestType" for the entity we're printing is probably 3796 // bad. 3797 switch (FailedOverloadResult) { 3798 case OR_Ambiguous: 3799 S.Diag(Kind.getLocation(), diag::err_ovl_ambiguous_init) 3800 << DestType << ArgsRange; 3801 S.PrintOverloadCandidates(FailedCandidateSet, 3802 Sema::OCD_ViableCandidates, Args, NumArgs); 3803 break; 3804 3805 case OR_No_Viable_Function: 3806 if (Kind.getKind() == InitializationKind::IK_Default && 3807 (Entity.getKind() == InitializedEntity::EK_Base || 3808 Entity.getKind() == InitializedEntity::EK_Member) && 3809 isa<CXXConstructorDecl>(S.CurContext)) { 3810 // This is implicit default initialization of a member or 3811 // base within a constructor. If no viable function was 3812 // found, notify the user that she needs to explicitly 3813 // initialize this base/member. 3814 CXXConstructorDecl *Constructor 3815 = cast<CXXConstructorDecl>(S.CurContext); 3816 if (Entity.getKind() == InitializedEntity::EK_Base) { 3817 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor) 3818 << Constructor->isImplicit() 3819 << S.Context.getTypeDeclType(Constructor->getParent()) 3820 << /*base=*/0 3821 << Entity.getType(); 3822 3823 RecordDecl *BaseDecl 3824 = Entity.getBaseSpecifier()->getType()->getAs<RecordType>() 3825 ->getDecl(); 3826 S.Diag(BaseDecl->getLocation(), diag::note_previous_decl) 3827 << S.Context.getTagDeclType(BaseDecl); 3828 } else { 3829 S.Diag(Kind.getLocation(), diag::err_missing_default_ctor) 3830 << Constructor->isImplicit() 3831 << S.Context.getTypeDeclType(Constructor->getParent()) 3832 << /*member=*/1 3833 << Entity.getName(); 3834 S.Diag(Entity.getDecl()->getLocation(), diag::note_field_decl); 3835 3836 if (const RecordType *Record 3837 = Entity.getType()->getAs<RecordType>()) 3838 S.Diag(Record->getDecl()->getLocation(), 3839 diag::note_previous_decl) 3840 << S.Context.getTagDeclType(Record->getDecl()); 3841 } 3842 break; 3843 } 3844 3845 S.Diag(Kind.getLocation(), diag::err_ovl_no_viable_function_in_init) 3846 << DestType << ArgsRange; 3847 S.PrintOverloadCandidates(FailedCandidateSet, Sema::OCD_AllCandidates, 3848 Args, NumArgs); 3849 break; 3850 3851 case OR_Deleted: { 3852 S.Diag(Kind.getLocation(), diag::err_ovl_deleted_init) 3853 << true << DestType << ArgsRange; 3854 OverloadCandidateSet::iterator Best; 3855 OverloadingResult Ovl = S.BestViableFunction(FailedCandidateSet, 3856 Kind.getLocation(), 3857 Best); 3858 if (Ovl == OR_Deleted) { 3859 S.Diag(Best->Function->getLocation(), diag::note_unavailable_here) 3860 << Best->Function->isDeleted(); 3861 } else { 3862 llvm_unreachable("Inconsistent overload resolution?"); 3863 } 3864 break; 3865 } 3866 3867 case OR_Success: 3868 llvm_unreachable("Conversion did not fail!"); 3869 break; 3870 } 3871 break; 3872 } 3873 3874 case FK_DefaultInitOfConst: 3875 if (Entity.getKind() == InitializedEntity::EK_Member && 3876 isa<CXXConstructorDecl>(S.CurContext)) { 3877 // This is implicit default-initialization of a const member in 3878 // a constructor. Complain that it needs to be explicitly 3879 // initialized. 3880 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(S.CurContext); 3881 S.Diag(Kind.getLocation(), diag::err_uninitialized_member_in_ctor) 3882 << Constructor->isImplicit() 3883 << S.Context.getTypeDeclType(Constructor->getParent()) 3884 << /*const=*/1 3885 << Entity.getName(); 3886 S.Diag(Entity.getDecl()->getLocation(), diag::note_previous_decl) 3887 << Entity.getName(); 3888 } else { 3889 S.Diag(Kind.getLocation(), diag::err_default_init_const) 3890 << DestType << (bool)DestType->getAs<RecordType>(); 3891 } 3892 break; 3893 } 3894 3895 return true; 3896} 3897 3898void InitializationSequence::dump(llvm::raw_ostream &OS) const { 3899 switch (SequenceKind) { 3900 case FailedSequence: { 3901 OS << "Failed sequence: "; 3902 switch (Failure) { 3903 case FK_TooManyInitsForReference: 3904 OS << "too many initializers for reference"; 3905 break; 3906 3907 case FK_ArrayNeedsInitList: 3908 OS << "array requires initializer list"; 3909 break; 3910 3911 case FK_ArrayNeedsInitListOrStringLiteral: 3912 OS << "array requires initializer list or string literal"; 3913 break; 3914 3915 case FK_AddressOfOverloadFailed: 3916 OS << "address of overloaded function failed"; 3917 break; 3918 3919 case FK_ReferenceInitOverloadFailed: 3920 OS << "overload resolution for reference initialization failed"; 3921 break; 3922 3923 case FK_NonConstLValueReferenceBindingToTemporary: 3924 OS << "non-const lvalue reference bound to temporary"; 3925 break; 3926 3927 case FK_NonConstLValueReferenceBindingToUnrelated: 3928 OS << "non-const lvalue reference bound to unrelated type"; 3929 break; 3930 3931 case FK_RValueReferenceBindingToLValue: 3932 OS << "rvalue reference bound to an lvalue"; 3933 break; 3934 3935 case FK_ReferenceInitDropsQualifiers: 3936 OS << "reference initialization drops qualifiers"; 3937 break; 3938 3939 case FK_ReferenceInitFailed: 3940 OS << "reference initialization failed"; 3941 break; 3942 3943 case FK_ConversionFailed: 3944 OS << "conversion failed"; 3945 break; 3946 3947 case FK_TooManyInitsForScalar: 3948 OS << "too many initializers for scalar"; 3949 break; 3950 3951 case FK_ReferenceBindingToInitList: 3952 OS << "referencing binding to initializer list"; 3953 break; 3954 3955 case FK_InitListBadDestinationType: 3956 OS << "initializer list for non-aggregate, non-scalar type"; 3957 break; 3958 3959 case FK_UserConversionOverloadFailed: 3960 OS << "overloading failed for user-defined conversion"; 3961 break; 3962 3963 case FK_ConstructorOverloadFailed: 3964 OS << "constructor overloading failed"; 3965 break; 3966 3967 case FK_DefaultInitOfConst: 3968 OS << "default initialization of a const variable"; 3969 break; 3970 } 3971 OS << '\n'; 3972 return; 3973 } 3974 3975 case DependentSequence: 3976 OS << "Dependent sequence: "; 3977 return; 3978 3979 case UserDefinedConversion: 3980 OS << "User-defined conversion sequence: "; 3981 break; 3982 3983 case ConstructorInitialization: 3984 OS << "Constructor initialization sequence: "; 3985 break; 3986 3987 case ReferenceBinding: 3988 OS << "Reference binding: "; 3989 break; 3990 3991 case ListInitialization: 3992 OS << "List initialization: "; 3993 break; 3994 3995 case ZeroInitialization: 3996 OS << "Zero initialization\n"; 3997 return; 3998 3999 case NoInitialization: 4000 OS << "No initialization\n"; 4001 return; 4002 4003 case StandardConversion: 4004 OS << "Standard conversion: "; 4005 break; 4006 4007 case CAssignment: 4008 OS << "C assignment: "; 4009 break; 4010 4011 case StringInit: 4012 OS << "String initialization: "; 4013 break; 4014 } 4015 4016 for (step_iterator S = step_begin(), SEnd = step_end(); S != SEnd; ++S) { 4017 if (S != step_begin()) { 4018 OS << " -> "; 4019 } 4020 4021 switch (S->Kind) { 4022 case SK_ResolveAddressOfOverloadedFunction: 4023 OS << "resolve address of overloaded function"; 4024 break; 4025 4026 case SK_CastDerivedToBaseRValue: 4027 OS << "derived-to-base case (rvalue" << S->Type.getAsString() << ")"; 4028 break; 4029 4030 case SK_CastDerivedToBaseLValue: 4031 OS << "derived-to-base case (lvalue" << S->Type.getAsString() << ")"; 4032 break; 4033 4034 case SK_BindReference: 4035 OS << "bind reference to lvalue"; 4036 break; 4037 4038 case SK_BindReferenceToTemporary: 4039 OS << "bind reference to a temporary"; 4040 break; 4041 4042 case SK_UserConversion: 4043 OS << "user-defined conversion via " << S->Function.Function; 4044 break; 4045 4046 case SK_QualificationConversionRValue: 4047 OS << "qualification conversion (rvalue)"; 4048 4049 case SK_QualificationConversionLValue: 4050 OS << "qualification conversion (lvalue)"; 4051 break; 4052 4053 case SK_ConversionSequence: 4054 OS << "implicit conversion sequence ("; 4055 S->ICS->DebugPrint(); // FIXME: use OS 4056 OS << ")"; 4057 break; 4058 4059 case SK_ListInitialization: 4060 OS << "list initialization"; 4061 break; 4062 4063 case SK_ConstructorInitialization: 4064 OS << "constructor initialization"; 4065 break; 4066 4067 case SK_ZeroInitialization: 4068 OS << "zero initialization"; 4069 break; 4070 4071 case SK_CAssignment: 4072 OS << "C assignment"; 4073 break; 4074 4075 case SK_StringInit: 4076 OS << "string initialization"; 4077 break; 4078 } 4079 } 4080} 4081 4082void InitializationSequence::dump() const { 4083 dump(llvm::errs()); 4084} 4085 4086//===----------------------------------------------------------------------===// 4087// Initialization helper functions 4088//===----------------------------------------------------------------------===// 4089Sema::OwningExprResult 4090Sema::PerformCopyInitialization(const InitializedEntity &Entity, 4091 SourceLocation EqualLoc, 4092 OwningExprResult Init) { 4093 if (Init.isInvalid()) 4094 return ExprError(); 4095 4096 Expr *InitE = (Expr *)Init.get(); 4097 assert(InitE && "No initialization expression?"); 4098 4099 if (EqualLoc.isInvalid()) 4100 EqualLoc = InitE->getLocStart(); 4101 4102 InitializationKind Kind = InitializationKind::CreateCopy(InitE->getLocStart(), 4103 EqualLoc); 4104 InitializationSequence Seq(*this, Entity, Kind, &InitE, 1); 4105 Init.release(); 4106 return Seq.Perform(*this, Entity, Kind, 4107 MultiExprArg(*this, (void**)&InitE, 1)); 4108} 4109