SemaInit.cpp revision c1efaecf0373f1a55c5ef4c234357cf726fc0600
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 "Sema.h" 19#include "clang/Parse/Designator.h" 20#include "clang/AST/ASTContext.h" 21#include "clang/AST/ExprObjC.h" 22#include <map> 23using namespace clang; 24 25//===----------------------------------------------------------------------===// 26// Sema Initialization Checking 27//===----------------------------------------------------------------------===// 28 29static Expr *IsStringInit(Expr *Init, QualType DeclType, ASTContext &Context) { 30 const ArrayType *AT = Context.getAsArrayType(DeclType); 31 if (!AT) return 0; 32 33 // See if this is a string literal or @encode. 34 Init = Init->IgnoreParens(); 35 36 // Handle @encode, which is a narrow string. 37 if (isa<ObjCEncodeExpr>(Init) && AT->getElementType()->isCharType()) 38 return Init; 39 40 // Otherwise we can only handle string literals. 41 StringLiteral *SL = dyn_cast<StringLiteral>(Init); 42 if (SL == 0) return 0; 43 44 // char array can be initialized with a narrow string. 45 // Only allow char x[] = "foo"; not char x[] = L"foo"; 46 if (!SL->isWide()) 47 return AT->getElementType()->isCharType() ? Init : 0; 48 49 // wchar_t array can be initialized with a wide string: C99 6.7.8p15: 50 // "An array with element type compatible with wchar_t may be initialized by a 51 // wide string literal, optionally enclosed in braces." 52 if (Context.typesAreCompatible(Context.getWCharType(), AT->getElementType())) 53 // Only allow wchar_t x[] = L"foo"; not wchar_t x[] = "foo"; 54 return Init; 55 56 return 0; 57} 58 59static bool CheckSingleInitializer(Expr *&Init, QualType DeclType, 60 bool DirectInit, Sema &S) { 61 // Get the type before calling CheckSingleAssignmentConstraints(), since 62 // it can promote the expression. 63 QualType InitType = Init->getType(); 64 65 if (S.getLangOptions().CPlusPlus) { 66 // FIXME: I dislike this error message. A lot. 67 if (S.PerformImplicitConversion(Init, DeclType, "initializing", DirectInit)) 68 return S.Diag(Init->getSourceRange().getBegin(), 69 diag::err_typecheck_convert_incompatible) 70 << DeclType << Init->getType() << "initializing" 71 << Init->getSourceRange(); 72 return false; 73 } 74 75 Sema::AssignConvertType ConvTy = 76 S.CheckSingleAssignmentConstraints(DeclType, Init); 77 return S.DiagnoseAssignmentResult(ConvTy, Init->getLocStart(), DeclType, 78 InitType, Init, "initializing"); 79} 80 81static void CheckStringInit(Expr *Str, QualType &DeclT, Sema &S) { 82 // Get the length of the string as parsed. 83 uint64_t StrLength = 84 cast<ConstantArrayType>(Str->getType())->getSize().getZExtValue(); 85 86 87 const ArrayType *AT = S.Context.getAsArrayType(DeclT); 88 if (const IncompleteArrayType *IAT = dyn_cast<IncompleteArrayType>(AT)) { 89 // C99 6.7.8p14. We have an array of character type with unknown size 90 // being initialized to a string literal. 91 llvm::APSInt ConstVal(32); 92 ConstVal = StrLength; 93 // Return a new array type (C99 6.7.8p22). 94 DeclT = S.Context.getConstantArrayType(IAT->getElementType(), ConstVal, 95 ArrayType::Normal, 0); 96 return; 97 } 98 99 const ConstantArrayType *CAT = cast<ConstantArrayType>(AT); 100 101 // C99 6.7.8p14. We have an array of character type with known size. However, 102 // the size may be smaller or larger than the string we are initializing. 103 // FIXME: Avoid truncation for 64-bit length strings. 104 if (StrLength-1 > CAT->getSize().getZExtValue()) 105 S.Diag(Str->getSourceRange().getBegin(), 106 diag::warn_initializer_string_for_char_array_too_long) 107 << Str->getSourceRange(); 108 109 // Set the type to the actual size that we are initializing. If we have 110 // something like: 111 // char x[1] = "foo"; 112 // then this will set the string literal's type to char[1]. 113 Str->setType(DeclT); 114} 115 116bool Sema::CheckInitializerTypes(Expr *&Init, QualType &DeclType, 117 SourceLocation InitLoc, 118 DeclarationName InitEntity, 119 bool DirectInit) { 120 if (DeclType->isDependentType() || Init->isTypeDependent()) 121 return false; 122 123 // C++ [dcl.init.ref]p1: 124 // A variable declared to be a T&, that is "reference to type T" 125 // (8.3.2), shall be initialized by an object, or function, of 126 // type T or by an object that can be converted into a T. 127 if (DeclType->isReferenceType()) 128 return CheckReferenceInit(Init, DeclType, 0, false, DirectInit); 129 130 // C99 6.7.8p3: The type of the entity to be initialized shall be an array 131 // of unknown size ("[]") or an object type that is not a variable array type. 132 if (const VariableArrayType *VAT = Context.getAsVariableArrayType(DeclType)) 133 return Diag(InitLoc, diag::err_variable_object_no_init) 134 << VAT->getSizeExpr()->getSourceRange(); 135 136 InitListExpr *InitList = dyn_cast<InitListExpr>(Init); 137 if (!InitList) { 138 // FIXME: Handle wide strings 139 if (Expr *Str = IsStringInit(Init, DeclType, Context)) { 140 CheckStringInit(Str, DeclType, *this); 141 return false; 142 } 143 144 // C++ [dcl.init]p14: 145 // -- If the destination type is a (possibly cv-qualified) class 146 // type: 147 if (getLangOptions().CPlusPlus && DeclType->isRecordType()) { 148 QualType DeclTypeC = Context.getCanonicalType(DeclType); 149 QualType InitTypeC = Context.getCanonicalType(Init->getType()); 150 151 // -- If the initialization is direct-initialization, or if it is 152 // copy-initialization where the cv-unqualified version of the 153 // source type is the same class as, or a derived class of, the 154 // class of the destination, constructors are considered. 155 if ((DeclTypeC.getUnqualifiedType() == InitTypeC.getUnqualifiedType()) || 156 IsDerivedFrom(InitTypeC, DeclTypeC)) { 157 CXXConstructorDecl *Constructor 158 = PerformInitializationByConstructor(DeclType, &Init, 1, 159 InitLoc, Init->getSourceRange(), 160 InitEntity, 161 DirectInit? IK_Direct : IK_Copy); 162 return Constructor == 0; 163 } 164 165 // -- Otherwise (i.e., for the remaining copy-initialization 166 // cases), user-defined conversion sequences that can 167 // convert from the source type to the destination type or 168 // (when a conversion function is used) to a derived class 169 // thereof are enumerated as described in 13.3.1.4, and the 170 // best one is chosen through overload resolution 171 // (13.3). If the conversion cannot be done or is 172 // ambiguous, the initialization is ill-formed. The 173 // function selected is called with the initializer 174 // expression as its argument; if the function is a 175 // constructor, the call initializes a temporary of the 176 // destination type. 177 // FIXME: We're pretending to do copy elision here; return to 178 // this when we have ASTs for such things. 179 if (!PerformImplicitConversion(Init, DeclType, "initializing")) 180 return false; 181 182 if (InitEntity) 183 return Diag(InitLoc, diag::err_cannot_initialize_decl) 184 << InitEntity << (int)(Init->isLvalue(Context) == Expr::LV_Valid) 185 << Init->getType() << Init->getSourceRange(); 186 else 187 return Diag(InitLoc, diag::err_cannot_initialize_decl_noname) 188 << DeclType << (int)(Init->isLvalue(Context) == Expr::LV_Valid) 189 << Init->getType() << Init->getSourceRange(); 190 } 191 192 // C99 6.7.8p16. 193 if (DeclType->isArrayType()) 194 return Diag(Init->getLocStart(), diag::err_array_init_list_required) 195 << Init->getSourceRange(); 196 197 return CheckSingleInitializer(Init, DeclType, DirectInit, *this); 198 } 199 200 bool hadError = CheckInitList(InitList, DeclType); 201 Init = InitList; 202 return hadError; 203} 204 205//===----------------------------------------------------------------------===// 206// Semantic checking for initializer lists. 207//===----------------------------------------------------------------------===// 208 209/// @brief Semantic checking for initializer lists. 210/// 211/// The InitListChecker class contains a set of routines that each 212/// handle the initialization of a certain kind of entity, e.g., 213/// arrays, vectors, struct/union types, scalars, etc. The 214/// InitListChecker itself performs a recursive walk of the subobject 215/// structure of the type to be initialized, while stepping through 216/// the initializer list one element at a time. The IList and Index 217/// parameters to each of the Check* routines contain the active 218/// (syntactic) initializer list and the index into that initializer 219/// list that represents the current initializer. Each routine is 220/// responsible for moving that Index forward as it consumes elements. 221/// 222/// Each Check* routine also has a StructuredList/StructuredIndex 223/// arguments, which contains the current the "structured" (semantic) 224/// initializer list and the index into that initializer list where we 225/// are copying initializers as we map them over to the semantic 226/// list. Once we have completed our recursive walk of the subobject 227/// structure, we will have constructed a full semantic initializer 228/// list. 229/// 230/// C99 designators cause changes in the initializer list traversal, 231/// because they make the initialization "jump" into a specific 232/// subobject and then continue the initialization from that 233/// point. CheckDesignatedInitializer() recursively steps into the 234/// designated subobject and manages backing out the recursion to 235/// initialize the subobjects after the one designated. 236namespace { 237class InitListChecker { 238 Sema &SemaRef; 239 bool hadError; 240 std::map<InitListExpr *, InitListExpr *> SyntacticToSemantic; 241 InitListExpr *FullyStructuredList; 242 243 void CheckImplicitInitList(InitListExpr *ParentIList, QualType T, 244 unsigned &Index, InitListExpr *StructuredList, 245 unsigned &StructuredIndex, 246 bool TopLevelObject = false); 247 void CheckExplicitInitList(InitListExpr *IList, QualType &T, 248 unsigned &Index, InitListExpr *StructuredList, 249 unsigned &StructuredIndex, 250 bool TopLevelObject = false); 251 void CheckListElementTypes(InitListExpr *IList, QualType &DeclType, 252 bool SubobjectIsDesignatorContext, 253 unsigned &Index, 254 InitListExpr *StructuredList, 255 unsigned &StructuredIndex, 256 bool TopLevelObject = false); 257 void CheckSubElementType(InitListExpr *IList, QualType ElemType, 258 unsigned &Index, 259 InitListExpr *StructuredList, 260 unsigned &StructuredIndex); 261 void CheckScalarType(InitListExpr *IList, QualType DeclType, 262 unsigned &Index, 263 InitListExpr *StructuredList, 264 unsigned &StructuredIndex); 265 void CheckReferenceType(InitListExpr *IList, QualType DeclType, 266 unsigned &Index, 267 InitListExpr *StructuredList, 268 unsigned &StructuredIndex); 269 void CheckVectorType(InitListExpr *IList, QualType DeclType, unsigned &Index, 270 InitListExpr *StructuredList, 271 unsigned &StructuredIndex); 272 void CheckStructUnionTypes(InitListExpr *IList, QualType DeclType, 273 RecordDecl::field_iterator Field, 274 bool SubobjectIsDesignatorContext, unsigned &Index, 275 InitListExpr *StructuredList, 276 unsigned &StructuredIndex, 277 bool TopLevelObject = false); 278 void CheckArrayType(InitListExpr *IList, QualType &DeclType, 279 llvm::APSInt elementIndex, 280 bool SubobjectIsDesignatorContext, unsigned &Index, 281 InitListExpr *StructuredList, 282 unsigned &StructuredIndex); 283 bool CheckDesignatedInitializer(InitListExpr *IList, DesignatedInitExpr *DIE, 284 DesignatedInitExpr::designators_iterator D, 285 QualType &CurrentObjectType, 286 RecordDecl::field_iterator *NextField, 287 llvm::APSInt *NextElementIndex, 288 unsigned &Index, 289 InitListExpr *StructuredList, 290 unsigned &StructuredIndex, 291 bool FinishSubobjectInit, 292 bool TopLevelObject); 293 InitListExpr *getStructuredSubobjectInit(InitListExpr *IList, unsigned Index, 294 QualType CurrentObjectType, 295 InitListExpr *StructuredList, 296 unsigned StructuredIndex, 297 SourceRange InitRange); 298 void UpdateStructuredListElement(InitListExpr *StructuredList, 299 unsigned &StructuredIndex, 300 Expr *expr); 301 int numArrayElements(QualType DeclType); 302 int numStructUnionElements(QualType DeclType); 303 304 void FillInValueInitializations(InitListExpr *ILE); 305public: 306 InitListChecker(Sema &S, InitListExpr *IL, QualType &T); 307 bool HadError() { return hadError; } 308 309 // @brief Retrieves the fully-structured initializer list used for 310 // semantic analysis and code generation. 311 InitListExpr *getFullyStructuredList() const { return FullyStructuredList; } 312}; 313} // end anonymous namespace 314 315/// Recursively replaces NULL values within the given initializer list 316/// with expressions that perform value-initialization of the 317/// appropriate type. 318void InitListChecker::FillInValueInitializations(InitListExpr *ILE) { 319 assert((ILE->getType() != SemaRef.Context.VoidTy) && 320 "Should not have void type"); 321 SourceLocation Loc = ILE->getSourceRange().getBegin(); 322 if (ILE->getSyntacticForm()) 323 Loc = ILE->getSyntacticForm()->getSourceRange().getBegin(); 324 325 if (const RecordType *RType = ILE->getType()->getAsRecordType()) { 326 unsigned Init = 0, NumInits = ILE->getNumInits(); 327 for (RecordDecl::field_iterator Field = RType->getDecl()->field_begin(), 328 FieldEnd = RType->getDecl()->field_end(); 329 Field != FieldEnd; ++Field) { 330 if (Field->isUnnamedBitfield()) 331 continue; 332 333 if (Init >= NumInits || !ILE->getInit(Init)) { 334 if (Field->getType()->isReferenceType()) { 335 // C++ [dcl.init.aggr]p9: 336 // If an incomplete or empty initializer-list leaves a 337 // member of reference type uninitialized, the program is 338 // ill-formed. 339 SemaRef.Diag(Loc, diag::err_init_reference_member_uninitialized) 340 << Field->getType() 341 << ILE->getSyntacticForm()->getSourceRange(); 342 SemaRef.Diag(Field->getLocation(), 343 diag::note_uninit_reference_member); 344 hadError = true; 345 return; 346 } else if (SemaRef.CheckValueInitialization(Field->getType(), Loc)) { 347 hadError = true; 348 return; 349 } 350 351 // FIXME: If value-initialization involves calling a 352 // constructor, should we make that call explicit in the 353 // representation (even when it means extending the 354 // initializer list)? 355 if (Init < NumInits && !hadError) 356 ILE->setInit(Init, 357 new (SemaRef.Context) ImplicitValueInitExpr(Field->getType())); 358 } else if (InitListExpr *InnerILE 359 = dyn_cast<InitListExpr>(ILE->getInit(Init))) 360 FillInValueInitializations(InnerILE); 361 ++Init; 362 363 // Only look at the first initialization of a union. 364 if (RType->getDecl()->isUnion()) 365 break; 366 } 367 368 return; 369 } 370 371 QualType ElementType; 372 373 unsigned NumInits = ILE->getNumInits(); 374 unsigned NumElements = NumInits; 375 if (const ArrayType *AType = SemaRef.Context.getAsArrayType(ILE->getType())) { 376 ElementType = AType->getElementType(); 377 if (const ConstantArrayType *CAType = dyn_cast<ConstantArrayType>(AType)) 378 NumElements = CAType->getSize().getZExtValue(); 379 } else if (const VectorType *VType = ILE->getType()->getAsVectorType()) { 380 ElementType = VType->getElementType(); 381 NumElements = VType->getNumElements(); 382 } else 383 ElementType = ILE->getType(); 384 385 for (unsigned Init = 0; Init != NumElements; ++Init) { 386 if (Init >= NumInits || !ILE->getInit(Init)) { 387 if (SemaRef.CheckValueInitialization(ElementType, Loc)) { 388 hadError = true; 389 return; 390 } 391 392 // FIXME: If value-initialization involves calling a 393 // constructor, should we make that call explicit in the 394 // representation (even when it means extending the 395 // initializer list)? 396 if (Init < NumInits && !hadError) 397 ILE->setInit(Init, 398 new (SemaRef.Context) ImplicitValueInitExpr(ElementType)); 399 } 400 else if (InitListExpr *InnerILE =dyn_cast<InitListExpr>(ILE->getInit(Init))) 401 FillInValueInitializations(InnerILE); 402 } 403} 404 405 406InitListChecker::InitListChecker(Sema &S, InitListExpr *IL, QualType &T) 407 : SemaRef(S) { 408 hadError = false; 409 410 unsigned newIndex = 0; 411 unsigned newStructuredIndex = 0; 412 FullyStructuredList 413 = getStructuredSubobjectInit(IL, newIndex, T, 0, 0, SourceRange()); 414 CheckExplicitInitList(IL, T, newIndex, FullyStructuredList, newStructuredIndex, 415 /*TopLevelObject=*/true); 416 417 if (!hadError) 418 FillInValueInitializations(FullyStructuredList); 419} 420 421int InitListChecker::numArrayElements(QualType DeclType) { 422 // FIXME: use a proper constant 423 int maxElements = 0x7FFFFFFF; 424 if (const ConstantArrayType *CAT = 425 SemaRef.Context.getAsConstantArrayType(DeclType)) { 426 maxElements = static_cast<int>(CAT->getSize().getZExtValue()); 427 } 428 return maxElements; 429} 430 431int InitListChecker::numStructUnionElements(QualType DeclType) { 432 RecordDecl *structDecl = DeclType->getAsRecordType()->getDecl(); 433 int InitializableMembers = 0; 434 for (RecordDecl::field_iterator Field = structDecl->field_begin(), 435 FieldEnd = structDecl->field_end(); 436 Field != FieldEnd; ++Field) { 437 if ((*Field)->getIdentifier() || !(*Field)->isBitField()) 438 ++InitializableMembers; 439 } 440 if (structDecl->isUnion()) 441 return std::min(InitializableMembers, 1); 442 return InitializableMembers - structDecl->hasFlexibleArrayMember(); 443} 444 445void InitListChecker::CheckImplicitInitList(InitListExpr *ParentIList, 446 QualType T, unsigned &Index, 447 InitListExpr *StructuredList, 448 unsigned &StructuredIndex, 449 bool TopLevelObject) { 450 int maxElements = 0; 451 452 if (T->isArrayType()) 453 maxElements = numArrayElements(T); 454 else if (T->isStructureType() || T->isUnionType()) 455 maxElements = numStructUnionElements(T); 456 else if (T->isVectorType()) 457 maxElements = T->getAsVectorType()->getNumElements(); 458 else 459 assert(0 && "CheckImplicitInitList(): Illegal type"); 460 461 if (maxElements == 0) { 462 SemaRef.Diag(ParentIList->getInit(Index)->getLocStart(), 463 diag::err_implicit_empty_initializer); 464 ++Index; 465 hadError = true; 466 return; 467 } 468 469 // Build a structured initializer list corresponding to this subobject. 470 InitListExpr *StructuredSubobjectInitList 471 = getStructuredSubobjectInit(ParentIList, Index, T, StructuredList, 472 StructuredIndex, 473 ParentIList->getInit(Index)->getSourceRange()); 474 unsigned StructuredSubobjectInitIndex = 0; 475 476 // Check the element types and build the structural subobject. 477 unsigned StartIndex = Index; 478 CheckListElementTypes(ParentIList, T, false, Index, 479 StructuredSubobjectInitList, 480 StructuredSubobjectInitIndex, 481 TopLevelObject); 482 unsigned EndIndex = (Index == StartIndex? StartIndex : Index - 1); 483 484 // Update the structured sub-object initialize so that it's ending 485 // range corresponds with the end of the last initializer it used. 486 if (EndIndex < ParentIList->getNumInits()) { 487 SourceLocation EndLoc 488 = ParentIList->getInit(EndIndex)->getSourceRange().getEnd(); 489 StructuredSubobjectInitList->setRBraceLoc(EndLoc); 490 } 491} 492 493void InitListChecker::CheckExplicitInitList(InitListExpr *IList, QualType &T, 494 unsigned &Index, 495 InitListExpr *StructuredList, 496 unsigned &StructuredIndex, 497 bool TopLevelObject) { 498 assert(IList->isExplicit() && "Illegal Implicit InitListExpr"); 499 SyntacticToSemantic[IList] = StructuredList; 500 StructuredList->setSyntacticForm(IList); 501 CheckListElementTypes(IList, T, true, Index, StructuredList, 502 StructuredIndex, TopLevelObject); 503 IList->setType(T); 504 StructuredList->setType(T); 505 if (hadError) 506 return; 507 508 if (Index < IList->getNumInits()) { 509 // We have leftover initializers 510 if (IList->getNumInits() > 0 && 511 IsStringInit(IList->getInit(Index), T, SemaRef.Context)) { 512 unsigned DK = diag::warn_excess_initializers_in_char_array_initializer; 513 if (SemaRef.getLangOptions().CPlusPlus) 514 DK = diag::err_excess_initializers_in_char_array_initializer; 515 // Special-case 516 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK) 517 << IList->getInit(Index)->getSourceRange(); 518 hadError = true; 519 } else if (!T->isIncompleteType()) { 520 // Don't complain for incomplete types, since we'll get an error 521 // elsewhere 522 QualType CurrentObjectType = StructuredList->getType(); 523 int initKind = 524 CurrentObjectType->isArrayType()? 0 : 525 CurrentObjectType->isVectorType()? 1 : 526 CurrentObjectType->isScalarType()? 2 : 527 CurrentObjectType->isUnionType()? 3 : 528 4; 529 530 unsigned DK = diag::warn_excess_initializers; 531 if (SemaRef.getLangOptions().CPlusPlus) 532 DK = diag::err_excess_initializers; 533 534 SemaRef.Diag(IList->getInit(Index)->getLocStart(), DK) 535 << initKind << IList->getInit(Index)->getSourceRange(); 536 } 537 } 538 539 if (T->isScalarType()) 540 SemaRef.Diag(IList->getLocStart(), diag::warn_braces_around_scalar_init) 541 << IList->getSourceRange(); 542} 543 544void InitListChecker::CheckListElementTypes(InitListExpr *IList, 545 QualType &DeclType, 546 bool SubobjectIsDesignatorContext, 547 unsigned &Index, 548 InitListExpr *StructuredList, 549 unsigned &StructuredIndex, 550 bool TopLevelObject) { 551 if (DeclType->isScalarType()) { 552 CheckScalarType(IList, DeclType, Index, StructuredList, StructuredIndex); 553 } else if (DeclType->isVectorType()) { 554 CheckVectorType(IList, DeclType, Index, StructuredList, StructuredIndex); 555 } else if (DeclType->isAggregateType()) { 556 if (DeclType->isRecordType()) { 557 RecordDecl *RD = DeclType->getAsRecordType()->getDecl(); 558 CheckStructUnionTypes(IList, DeclType, RD->field_begin(), 559 SubobjectIsDesignatorContext, Index, 560 StructuredList, StructuredIndex, 561 TopLevelObject); 562 } else if (DeclType->isArrayType()) { 563 llvm::APSInt Zero( 564 SemaRef.Context.getTypeSize(SemaRef.Context.getSizeType()), 565 false); 566 CheckArrayType(IList, DeclType, Zero, SubobjectIsDesignatorContext, Index, 567 StructuredList, StructuredIndex); 568 } 569 else 570 assert(0 && "Aggregate that isn't a structure or array?!"); 571 } else if (DeclType->isVoidType() || DeclType->isFunctionType()) { 572 // This type is invalid, issue a diagnostic. 573 ++Index; 574 SemaRef.Diag(IList->getLocStart(), diag::err_illegal_initializer_type) 575 << DeclType; 576 hadError = true; 577 } else if (DeclType->isRecordType()) { 578 // C++ [dcl.init]p14: 579 // [...] If the class is an aggregate (8.5.1), and the initializer 580 // is a brace-enclosed list, see 8.5.1. 581 // 582 // Note: 8.5.1 is handled below; here, we diagnose the case where 583 // we have an initializer list and a destination type that is not 584 // an aggregate. 585 // FIXME: In C++0x, this is yet another form of initialization. 586 SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list) 587 << DeclType << IList->getSourceRange(); 588 hadError = true; 589 } else if (DeclType->isReferenceType()) { 590 CheckReferenceType(IList, DeclType, Index, StructuredList, StructuredIndex); 591 } else { 592 // In C, all types are either scalars or aggregates, but 593 // additional handling is needed here for C++ (and possibly others?). 594 assert(0 && "Unsupported initializer type"); 595 } 596} 597 598void InitListChecker::CheckSubElementType(InitListExpr *IList, 599 QualType ElemType, 600 unsigned &Index, 601 InitListExpr *StructuredList, 602 unsigned &StructuredIndex) { 603 Expr *expr = IList->getInit(Index); 604 if (InitListExpr *SubInitList = dyn_cast<InitListExpr>(expr)) { 605 unsigned newIndex = 0; 606 unsigned newStructuredIndex = 0; 607 InitListExpr *newStructuredList 608 = getStructuredSubobjectInit(IList, Index, ElemType, 609 StructuredList, StructuredIndex, 610 SubInitList->getSourceRange()); 611 CheckExplicitInitList(SubInitList, ElemType, newIndex, 612 newStructuredList, newStructuredIndex); 613 ++StructuredIndex; 614 ++Index; 615 } else if (Expr *Str = IsStringInit(expr, ElemType, SemaRef.Context)) { 616 CheckStringInit(Str, ElemType, SemaRef); 617 UpdateStructuredListElement(StructuredList, StructuredIndex, Str); 618 ++Index; 619 } else if (ElemType->isScalarType()) { 620 CheckScalarType(IList, ElemType, Index, StructuredList, StructuredIndex); 621 } else if (ElemType->isReferenceType()) { 622 CheckReferenceType(IList, ElemType, Index, StructuredList, StructuredIndex); 623 } else { 624 if (SemaRef.getLangOptions().CPlusPlus) { 625 // C++ [dcl.init.aggr]p12: 626 // All implicit type conversions (clause 4) are considered when 627 // initializing the aggregate member with an ini- tializer from 628 // an initializer-list. If the initializer can initialize a 629 // member, the member is initialized. [...] 630 ImplicitConversionSequence ICS 631 = SemaRef.TryCopyInitialization(expr, ElemType); 632 if (ICS.ConversionKind != ImplicitConversionSequence::BadConversion) { 633 if (SemaRef.PerformImplicitConversion(expr, ElemType, ICS, 634 "initializing")) 635 hadError = true; 636 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 637 ++Index; 638 return; 639 } 640 641 // Fall through for subaggregate initialization 642 } else { 643 // C99 6.7.8p13: 644 // 645 // The initializer for a structure or union object that has 646 // automatic storage duration shall be either an initializer 647 // list as described below, or a single expression that has 648 // compatible structure or union type. In the latter case, the 649 // initial value of the object, including unnamed members, is 650 // that of the expression. 651 QualType ExprType = SemaRef.Context.getCanonicalType(expr->getType()); 652 QualType ElemTypeCanon = SemaRef.Context.getCanonicalType(ElemType); 653 if (SemaRef.Context.typesAreCompatible(ExprType.getUnqualifiedType(), 654 ElemTypeCanon.getUnqualifiedType())) { 655 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 656 ++Index; 657 return; 658 } 659 660 // Fall through for subaggregate initialization 661 } 662 663 // C++ [dcl.init.aggr]p12: 664 // 665 // [...] Otherwise, if the member is itself a non-empty 666 // subaggregate, brace elision is assumed and the initializer is 667 // considered for the initialization of the first member of 668 // the subaggregate. 669 if (ElemType->isAggregateType() || ElemType->isVectorType()) { 670 CheckImplicitInitList(IList, ElemType, Index, StructuredList, 671 StructuredIndex); 672 ++StructuredIndex; 673 } else { 674 // We cannot initialize this element, so let 675 // PerformCopyInitialization produce the appropriate diagnostic. 676 SemaRef.PerformCopyInitialization(expr, ElemType, "initializing"); 677 hadError = true; 678 ++Index; 679 ++StructuredIndex; 680 } 681 } 682} 683 684void InitListChecker::CheckScalarType(InitListExpr *IList, QualType DeclType, 685 unsigned &Index, 686 InitListExpr *StructuredList, 687 unsigned &StructuredIndex) { 688 if (Index < IList->getNumInits()) { 689 Expr *expr = IList->getInit(Index); 690 if (isa<InitListExpr>(expr)) { 691 SemaRef.Diag(IList->getLocStart(), 692 diag::err_many_braces_around_scalar_init) 693 << IList->getSourceRange(); 694 hadError = true; 695 ++Index; 696 ++StructuredIndex; 697 return; 698 } else if (isa<DesignatedInitExpr>(expr)) { 699 SemaRef.Diag(expr->getSourceRange().getBegin(), 700 diag::err_designator_for_scalar_init) 701 << DeclType << expr->getSourceRange(); 702 hadError = true; 703 ++Index; 704 ++StructuredIndex; 705 return; 706 } 707 708 Expr *savExpr = expr; // Might be promoted by CheckSingleInitializer. 709 if (CheckSingleInitializer(expr, DeclType, false, SemaRef)) 710 hadError = true; // types weren't compatible. 711 else if (savExpr != expr) { 712 // The type was promoted, update initializer list. 713 IList->setInit(Index, expr); 714 } 715 if (hadError) 716 ++StructuredIndex; 717 else 718 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 719 ++Index; 720 } else { 721 SemaRef.Diag(IList->getLocStart(), diag::err_empty_scalar_initializer) 722 << IList->getSourceRange(); 723 hadError = true; 724 ++Index; 725 ++StructuredIndex; 726 return; 727 } 728} 729 730void InitListChecker::CheckReferenceType(InitListExpr *IList, QualType DeclType, 731 unsigned &Index, 732 InitListExpr *StructuredList, 733 unsigned &StructuredIndex) { 734 if (Index < IList->getNumInits()) { 735 Expr *expr = IList->getInit(Index); 736 if (isa<InitListExpr>(expr)) { 737 SemaRef.Diag(IList->getLocStart(), diag::err_init_non_aggr_init_list) 738 << DeclType << IList->getSourceRange(); 739 hadError = true; 740 ++Index; 741 ++StructuredIndex; 742 return; 743 } 744 745 Expr *savExpr = expr; // Might be promoted by CheckSingleInitializer. 746 if (SemaRef.CheckReferenceInit(expr, DeclType)) 747 hadError = true; 748 else if (savExpr != expr) { 749 // The type was promoted, update initializer list. 750 IList->setInit(Index, expr); 751 } 752 if (hadError) 753 ++StructuredIndex; 754 else 755 UpdateStructuredListElement(StructuredList, StructuredIndex, expr); 756 ++Index; 757 } else { 758 // FIXME: It would be wonderful if we could point at the actual 759 // member. In general, it would be useful to pass location 760 // information down the stack, so that we know the location (or 761 // decl) of the "current object" being initialized. 762 SemaRef.Diag(IList->getLocStart(), 763 diag::err_init_reference_member_uninitialized) 764 << DeclType 765 << IList->getSourceRange(); 766 hadError = true; 767 ++Index; 768 ++StructuredIndex; 769 return; 770 } 771} 772 773void InitListChecker::CheckVectorType(InitListExpr *IList, QualType DeclType, 774 unsigned &Index, 775 InitListExpr *StructuredList, 776 unsigned &StructuredIndex) { 777 if (Index < IList->getNumInits()) { 778 const VectorType *VT = DeclType->getAsVectorType(); 779 int maxElements = VT->getNumElements(); 780 QualType elementType = VT->getElementType(); 781 782 for (int i = 0; i < maxElements; ++i) { 783 // Don't attempt to go past the end of the init list 784 if (Index >= IList->getNumInits()) 785 break; 786 CheckSubElementType(IList, elementType, Index, 787 StructuredList, StructuredIndex); 788 } 789 } 790} 791 792void InitListChecker::CheckArrayType(InitListExpr *IList, QualType &DeclType, 793 llvm::APSInt elementIndex, 794 bool SubobjectIsDesignatorContext, 795 unsigned &Index, 796 InitListExpr *StructuredList, 797 unsigned &StructuredIndex) { 798 // Check for the special-case of initializing an array with a string. 799 if (Index < IList->getNumInits()) { 800 if (Expr *Str = IsStringInit(IList->getInit(Index), DeclType, 801 SemaRef.Context)) { 802 CheckStringInit(Str, DeclType, SemaRef); 803 // We place the string literal directly into the resulting 804 // initializer list. This is the only place where the structure 805 // of the structured initializer list doesn't match exactly, 806 // because doing so would involve allocating one character 807 // constant for each string. 808 UpdateStructuredListElement(StructuredList, StructuredIndex, Str); 809 StructuredList->resizeInits(SemaRef.Context, StructuredIndex); 810 ++Index; 811 return; 812 } 813 } 814 if (const VariableArrayType *VAT = 815 SemaRef.Context.getAsVariableArrayType(DeclType)) { 816 // Check for VLAs; in standard C it would be possible to check this 817 // earlier, but I don't know where clang accepts VLAs (gcc accepts 818 // them in all sorts of strange places). 819 SemaRef.Diag(VAT->getSizeExpr()->getLocStart(), 820 diag::err_variable_object_no_init) 821 << VAT->getSizeExpr()->getSourceRange(); 822 hadError = true; 823 ++Index; 824 ++StructuredIndex; 825 return; 826 } 827 828 // We might know the maximum number of elements in advance. 829 llvm::APSInt maxElements(elementIndex.getBitWidth(), 830 elementIndex.isUnsigned()); 831 bool maxElementsKnown = false; 832 if (const ConstantArrayType *CAT = 833 SemaRef.Context.getAsConstantArrayType(DeclType)) { 834 maxElements = CAT->getSize(); 835 elementIndex.extOrTrunc(maxElements.getBitWidth()); 836 elementIndex.setIsUnsigned(maxElements.isUnsigned()); 837 maxElementsKnown = true; 838 } 839 840 QualType elementType = SemaRef.Context.getAsArrayType(DeclType) 841 ->getElementType(); 842 while (Index < IList->getNumInits()) { 843 Expr *Init = IList->getInit(Index); 844 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) { 845 // If we're not the subobject that matches up with the '{' for 846 // the designator, we shouldn't be handling the 847 // designator. Return immediately. 848 if (!SubobjectIsDesignatorContext) 849 return; 850 851 // Handle this designated initializer. elementIndex will be 852 // updated to be the next array element we'll initialize. 853 if (CheckDesignatedInitializer(IList, DIE, DIE->designators_begin(), 854 DeclType, 0, &elementIndex, Index, 855 StructuredList, StructuredIndex, true, 856 false)) { 857 hadError = true; 858 continue; 859 } 860 861 if (elementIndex.getBitWidth() > maxElements.getBitWidth()) 862 maxElements.extend(elementIndex.getBitWidth()); 863 else if (elementIndex.getBitWidth() < maxElements.getBitWidth()) 864 elementIndex.extend(maxElements.getBitWidth()); 865 elementIndex.setIsUnsigned(maxElements.isUnsigned()); 866 867 // If the array is of incomplete type, keep track of the number of 868 // elements in the initializer. 869 if (!maxElementsKnown && elementIndex > maxElements) 870 maxElements = elementIndex; 871 872 continue; 873 } 874 875 // If we know the maximum number of elements, and we've already 876 // hit it, stop consuming elements in the initializer list. 877 if (maxElementsKnown && elementIndex == maxElements) 878 break; 879 880 // Check this element. 881 CheckSubElementType(IList, elementType, Index, 882 StructuredList, StructuredIndex); 883 ++elementIndex; 884 885 // If the array is of incomplete type, keep track of the number of 886 // elements in the initializer. 887 if (!maxElementsKnown && elementIndex > maxElements) 888 maxElements = elementIndex; 889 } 890 if (DeclType->isIncompleteArrayType()) { 891 // If this is an incomplete array type, the actual type needs to 892 // be calculated here. 893 llvm::APSInt Zero(maxElements.getBitWidth(), maxElements.isUnsigned()); 894 if (maxElements == Zero) { 895 // Sizing an array implicitly to zero is not allowed by ISO C, 896 // but is supported by GNU. 897 SemaRef.Diag(IList->getLocStart(), 898 diag::ext_typecheck_zero_array_size); 899 } 900 901 DeclType = SemaRef.Context.getConstantArrayType(elementType, maxElements, 902 ArrayType::Normal, 0); 903 } 904} 905 906void InitListChecker::CheckStructUnionTypes(InitListExpr *IList, 907 QualType DeclType, 908 RecordDecl::field_iterator Field, 909 bool SubobjectIsDesignatorContext, 910 unsigned &Index, 911 InitListExpr *StructuredList, 912 unsigned &StructuredIndex, 913 bool TopLevelObject) { 914 RecordDecl* structDecl = DeclType->getAsRecordType()->getDecl(); 915 916 // If the record is invalid, some of it's members are invalid. To avoid 917 // confusion, we forgo checking the intializer for the entire record. 918 if (structDecl->isInvalidDecl()) { 919 hadError = true; 920 return; 921 } 922 923 if (DeclType->isUnionType() && IList->getNumInits() == 0) { 924 // Value-initialize the first named member of the union. 925 RecordDecl *RD = DeclType->getAsRecordType()->getDecl(); 926 for (RecordDecl::field_iterator FieldEnd = RD->field_end(); 927 Field != FieldEnd; ++Field) { 928 if (Field->getDeclName()) { 929 StructuredList->setInitializedFieldInUnion(*Field); 930 break; 931 } 932 } 933 return; 934 } 935 936 // If structDecl is a forward declaration, this loop won't do 937 // anything except look at designated initializers; That's okay, 938 // because an error should get printed out elsewhere. It might be 939 // worthwhile to skip over the rest of the initializer, though. 940 RecordDecl *RD = DeclType->getAsRecordType()->getDecl(); 941 RecordDecl::field_iterator FieldEnd = RD->field_end(); 942 bool InitializedSomething = false; 943 while (Index < IList->getNumInits()) { 944 Expr *Init = IList->getInit(Index); 945 946 if (DesignatedInitExpr *DIE = dyn_cast<DesignatedInitExpr>(Init)) { 947 // If we're not the subobject that matches up with the '{' for 948 // the designator, we shouldn't be handling the 949 // designator. Return immediately. 950 if (!SubobjectIsDesignatorContext) 951 return; 952 953 // Handle this designated initializer. Field will be updated to 954 // the next field that we'll be initializing. 955 if (CheckDesignatedInitializer(IList, DIE, DIE->designators_begin(), 956 DeclType, &Field, 0, Index, 957 StructuredList, StructuredIndex, 958 true, TopLevelObject)) 959 hadError = true; 960 961 InitializedSomething = true; 962 continue; 963 } 964 965 if (Field == FieldEnd) { 966 // We've run out of fields. We're done. 967 break; 968 } 969 970 // We've already initialized a member of a union. We're done. 971 if (InitializedSomething && DeclType->isUnionType()) 972 break; 973 974 // If we've hit the flexible array member at the end, we're done. 975 if (Field->getType()->isIncompleteArrayType()) 976 break; 977 978 if (Field->isUnnamedBitfield()) { 979 // Don't initialize unnamed bitfields, e.g. "int : 20;" 980 ++Field; 981 continue; 982 } 983 984 CheckSubElementType(IList, Field->getType(), Index, 985 StructuredList, StructuredIndex); 986 InitializedSomething = true; 987 988 if (DeclType->isUnionType()) { 989 // Initialize the first field within the union. 990 StructuredList->setInitializedFieldInUnion(*Field); 991 } 992 993 ++Field; 994 } 995 996 if (Field == FieldEnd || !Field->getType()->isIncompleteArrayType() || 997 Index >= IList->getNumInits() || 998 !isa<InitListExpr>(IList->getInit(Index))) 999 return; 1000 1001 // Handle GNU flexible array initializers. 1002 if (!TopLevelObject && 1003 cast<InitListExpr>(IList->getInit(Index))->getNumInits() > 0) { 1004 SemaRef.Diag(IList->getInit(Index)->getSourceRange().getBegin(), 1005 diag::err_flexible_array_init_nonempty) 1006 << IList->getInit(Index)->getSourceRange().getBegin(); 1007 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1008 << *Field; 1009 hadError = true; 1010 } 1011 1012 CheckSubElementType(IList, Field->getType(), Index, StructuredList, 1013 StructuredIndex); 1014} 1015 1016/// @brief Check the well-formedness of a C99 designated initializer. 1017/// 1018/// Determines whether the designated initializer @p DIE, which 1019/// resides at the given @p Index within the initializer list @p 1020/// IList, is well-formed for a current object of type @p DeclType 1021/// (C99 6.7.8). The actual subobject that this designator refers to 1022/// within the current subobject is returned in either 1023/// @p NextField or @p NextElementIndex (whichever is appropriate). 1024/// 1025/// @param IList The initializer list in which this designated 1026/// initializer occurs. 1027/// 1028/// @param DIE The designated initializer and its initialization 1029/// expression. 1030/// 1031/// @param DeclType The type of the "current object" (C99 6.7.8p17), 1032/// into which the designation in @p DIE should refer. 1033/// 1034/// @param NextField If non-NULL and the first designator in @p DIE is 1035/// a field, this will be set to the field declaration corresponding 1036/// to the field named by the designator. 1037/// 1038/// @param NextElementIndex If non-NULL and the first designator in @p 1039/// DIE is an array designator or GNU array-range designator, this 1040/// will be set to the last index initialized by this designator. 1041/// 1042/// @param Index Index into @p IList where the designated initializer 1043/// @p DIE occurs. 1044/// 1045/// @param StructuredList The initializer list expression that 1046/// describes all of the subobject initializers in the order they'll 1047/// actually be initialized. 1048/// 1049/// @returns true if there was an error, false otherwise. 1050bool 1051InitListChecker::CheckDesignatedInitializer(InitListExpr *IList, 1052 DesignatedInitExpr *DIE, 1053 DesignatedInitExpr::designators_iterator D, 1054 QualType &CurrentObjectType, 1055 RecordDecl::field_iterator *NextField, 1056 llvm::APSInt *NextElementIndex, 1057 unsigned &Index, 1058 InitListExpr *StructuredList, 1059 unsigned &StructuredIndex, 1060 bool FinishSubobjectInit, 1061 bool TopLevelObject) { 1062 if (D == DIE->designators_end()) { 1063 // Check the actual initialization for the designated object type. 1064 bool prevHadError = hadError; 1065 1066 // Temporarily remove the designator expression from the 1067 // initializer list that the child calls see, so that we don't try 1068 // to re-process the designator. 1069 unsigned OldIndex = Index; 1070 IList->setInit(OldIndex, DIE->getInit()); 1071 1072 CheckSubElementType(IList, CurrentObjectType, Index, 1073 StructuredList, StructuredIndex); 1074 1075 // Restore the designated initializer expression in the syntactic 1076 // form of the initializer list. 1077 if (IList->getInit(OldIndex) != DIE->getInit()) 1078 DIE->setInit(IList->getInit(OldIndex)); 1079 IList->setInit(OldIndex, DIE); 1080 1081 return hadError && !prevHadError; 1082 } 1083 1084 bool IsFirstDesignator = (D == DIE->designators_begin()); 1085 assert((IsFirstDesignator || StructuredList) && 1086 "Need a non-designated initializer list to start from"); 1087 1088 // Determine the structural initializer list that corresponds to the 1089 // current subobject. 1090 StructuredList = IsFirstDesignator? SyntacticToSemantic[IList] 1091 : getStructuredSubobjectInit(IList, Index, CurrentObjectType, StructuredList, 1092 StructuredIndex, 1093 SourceRange(D->getStartLocation(), 1094 DIE->getSourceRange().getEnd())); 1095 assert(StructuredList && "Expected a structured initializer list"); 1096 1097 if (D->isFieldDesignator()) { 1098 // C99 6.7.8p7: 1099 // 1100 // If a designator has the form 1101 // 1102 // . identifier 1103 // 1104 // then the current object (defined below) shall have 1105 // structure or union type and the identifier shall be the 1106 // name of a member of that type. 1107 const RecordType *RT = CurrentObjectType->getAsRecordType(); 1108 if (!RT) { 1109 SourceLocation Loc = D->getDotLoc(); 1110 if (Loc.isInvalid()) 1111 Loc = D->getFieldLoc(); 1112 SemaRef.Diag(Loc, diag::err_field_designator_non_aggr) 1113 << SemaRef.getLangOptions().CPlusPlus << CurrentObjectType; 1114 ++Index; 1115 return true; 1116 } 1117 1118 // Note: we perform a linear search of the fields here, despite 1119 // the fact that we have a faster lookup method, because we always 1120 // need to compute the field's index. 1121 IdentifierInfo *FieldName = D->getFieldName(); 1122 unsigned FieldIndex = 0; 1123 RecordDecl::field_iterator Field = RT->getDecl()->field_begin(), 1124 FieldEnd = RT->getDecl()->field_end(); 1125 for (; Field != FieldEnd; ++Field) { 1126 if (Field->isUnnamedBitfield()) 1127 continue; 1128 1129 if (Field->getIdentifier() == FieldName) 1130 break; 1131 1132 ++FieldIndex; 1133 } 1134 1135 if (Field == FieldEnd) { 1136 // We did not find the field we're looking for. Produce a 1137 // suitable diagnostic and return a failure. 1138 DeclContext::lookup_result Lookup = RT->getDecl()->lookup(FieldName); 1139 if (Lookup.first == Lookup.second) { 1140 // Name lookup didn't find anything. 1141 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_unknown) 1142 << FieldName << CurrentObjectType; 1143 } else { 1144 // Name lookup found something, but it wasn't a field. 1145 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_nonfield) 1146 << FieldName; 1147 SemaRef.Diag((*Lookup.first)->getLocation(), 1148 diag::note_field_designator_found); 1149 } 1150 1151 ++Index; 1152 return true; 1153 } else if (cast<RecordDecl>((*Field)->getDeclContext()) 1154 ->isAnonymousStructOrUnion()) { 1155 SemaRef.Diag(D->getFieldLoc(), diag::err_field_designator_anon_class) 1156 << FieldName 1157 << (cast<RecordDecl>((*Field)->getDeclContext())->isUnion()? 2 : 1158 (int)SemaRef.getLangOptions().CPlusPlus); 1159 SemaRef.Diag((*Field)->getLocation(), diag::note_field_designator_found); 1160 ++Index; 1161 return true; 1162 } 1163 1164 // All of the fields of a union are located at the same place in 1165 // the initializer list. 1166 if (RT->getDecl()->isUnion()) { 1167 FieldIndex = 0; 1168 StructuredList->setInitializedFieldInUnion(*Field); 1169 } 1170 1171 // Update the designator with the field declaration. 1172 D->setField(*Field); 1173 1174 // Make sure that our non-designated initializer list has space 1175 // for a subobject corresponding to this field. 1176 if (FieldIndex >= StructuredList->getNumInits()) 1177 StructuredList->resizeInits(SemaRef.Context, FieldIndex + 1); 1178 1179 // This designator names a flexible array member. 1180 if (Field->getType()->isIncompleteArrayType()) { 1181 bool Invalid = false; 1182 DesignatedInitExpr::designators_iterator NextD = D; 1183 ++NextD; 1184 if (NextD != DIE->designators_end()) { 1185 // We can't designate an object within the flexible array 1186 // member (because GCC doesn't allow it). 1187 SemaRef.Diag(NextD->getStartLocation(), 1188 diag::err_designator_into_flexible_array_member) 1189 << SourceRange(NextD->getStartLocation(), 1190 DIE->getSourceRange().getEnd()); 1191 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1192 << *Field; 1193 Invalid = true; 1194 } 1195 1196 if (!hadError && !isa<InitListExpr>(DIE->getInit())) { 1197 // The initializer is not an initializer list. 1198 SemaRef.Diag(DIE->getInit()->getSourceRange().getBegin(), 1199 diag::err_flexible_array_init_needs_braces) 1200 << DIE->getInit()->getSourceRange(); 1201 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1202 << *Field; 1203 Invalid = true; 1204 } 1205 1206 // Handle GNU flexible array initializers. 1207 if (!Invalid && !TopLevelObject && 1208 cast<InitListExpr>(DIE->getInit())->getNumInits() > 0) { 1209 SemaRef.Diag(DIE->getSourceRange().getBegin(), 1210 diag::err_flexible_array_init_nonempty) 1211 << DIE->getSourceRange().getBegin(); 1212 SemaRef.Diag(Field->getLocation(), diag::note_flexible_array_member) 1213 << *Field; 1214 Invalid = true; 1215 } 1216 1217 if (Invalid) { 1218 ++Index; 1219 return true; 1220 } 1221 1222 // Initialize the array. 1223 bool prevHadError = hadError; 1224 unsigned newStructuredIndex = FieldIndex; 1225 unsigned OldIndex = Index; 1226 IList->setInit(Index, DIE->getInit()); 1227 CheckSubElementType(IList, Field->getType(), Index, 1228 StructuredList, newStructuredIndex); 1229 IList->setInit(OldIndex, DIE); 1230 if (hadError && !prevHadError) { 1231 ++Field; 1232 ++FieldIndex; 1233 if (NextField) 1234 *NextField = Field; 1235 StructuredIndex = FieldIndex; 1236 return true; 1237 } 1238 } else { 1239 // Recurse to check later designated subobjects. 1240 QualType FieldType = (*Field)->getType(); 1241 unsigned newStructuredIndex = FieldIndex; 1242 if (CheckDesignatedInitializer(IList, DIE, ++D, FieldType, 0, 0, Index, 1243 StructuredList, newStructuredIndex, 1244 true, false)) 1245 return true; 1246 } 1247 1248 // Find the position of the next field to be initialized in this 1249 // subobject. 1250 ++Field; 1251 ++FieldIndex; 1252 1253 // If this the first designator, our caller will continue checking 1254 // the rest of this struct/class/union subobject. 1255 if (IsFirstDesignator) { 1256 if (NextField) 1257 *NextField = Field; 1258 StructuredIndex = FieldIndex; 1259 return false; 1260 } 1261 1262 if (!FinishSubobjectInit) 1263 return false; 1264 1265 // Check the remaining fields within this class/struct/union subobject. 1266 bool prevHadError = hadError; 1267 CheckStructUnionTypes(IList, CurrentObjectType, Field, false, Index, 1268 StructuredList, FieldIndex); 1269 return hadError && !prevHadError; 1270 } 1271 1272 // C99 6.7.8p6: 1273 // 1274 // If a designator has the form 1275 // 1276 // [ constant-expression ] 1277 // 1278 // then the current object (defined below) shall have array 1279 // type and the expression shall be an integer constant 1280 // expression. If the array is of unknown size, any 1281 // nonnegative value is valid. 1282 // 1283 // Additionally, cope with the GNU extension that permits 1284 // designators of the form 1285 // 1286 // [ constant-expression ... constant-expression ] 1287 const ArrayType *AT = SemaRef.Context.getAsArrayType(CurrentObjectType); 1288 if (!AT) { 1289 SemaRef.Diag(D->getLBracketLoc(), diag::err_array_designator_non_array) 1290 << CurrentObjectType; 1291 ++Index; 1292 return true; 1293 } 1294 1295 Expr *IndexExpr = 0; 1296 llvm::APSInt DesignatedStartIndex, DesignatedEndIndex; 1297 if (D->isArrayDesignator()) { 1298 IndexExpr = DIE->getArrayIndex(*D); 1299 1300 bool ConstExpr 1301 = IndexExpr->isIntegerConstantExpr(DesignatedStartIndex, SemaRef.Context); 1302 assert(ConstExpr && "Expression must be constant"); (void)ConstExpr; 1303 1304 DesignatedEndIndex = DesignatedStartIndex; 1305 } else { 1306 assert(D->isArrayRangeDesignator() && "Need array-range designator"); 1307 1308 bool StartConstExpr 1309 = DIE->getArrayRangeStart(*D)->isIntegerConstantExpr(DesignatedStartIndex, 1310 SemaRef.Context); 1311 assert(StartConstExpr && "Expression must be constant"); (void)StartConstExpr; 1312 1313 bool EndConstExpr 1314 = DIE->getArrayRangeEnd(*D)->isIntegerConstantExpr(DesignatedEndIndex, 1315 SemaRef.Context); 1316 assert(EndConstExpr && "Expression must be constant"); (void)EndConstExpr; 1317 1318 IndexExpr = DIE->getArrayRangeEnd(*D); 1319 1320 if (DesignatedStartIndex.getZExtValue() != DesignatedEndIndex.getZExtValue()) 1321 FullyStructuredList->sawArrayRangeDesignator(); 1322 } 1323 1324 if (isa<ConstantArrayType>(AT)) { 1325 llvm::APSInt MaxElements(cast<ConstantArrayType>(AT)->getSize(), false); 1326 DesignatedStartIndex.extOrTrunc(MaxElements.getBitWidth()); 1327 DesignatedStartIndex.setIsUnsigned(MaxElements.isUnsigned()); 1328 DesignatedEndIndex.extOrTrunc(MaxElements.getBitWidth()); 1329 DesignatedEndIndex.setIsUnsigned(MaxElements.isUnsigned()); 1330 if (DesignatedEndIndex >= MaxElements) { 1331 SemaRef.Diag(IndexExpr->getSourceRange().getBegin(), 1332 diag::err_array_designator_too_large) 1333 << DesignatedEndIndex.toString(10) << MaxElements.toString(10) 1334 << IndexExpr->getSourceRange(); 1335 ++Index; 1336 return true; 1337 } 1338 } else { 1339 // Make sure the bit-widths and signedness match. 1340 if (DesignatedStartIndex.getBitWidth() > DesignatedEndIndex.getBitWidth()) 1341 DesignatedEndIndex.extend(DesignatedStartIndex.getBitWidth()); 1342 else if (DesignatedStartIndex.getBitWidth() < DesignatedEndIndex.getBitWidth()) 1343 DesignatedStartIndex.extend(DesignatedEndIndex.getBitWidth()); 1344 DesignatedStartIndex.setIsUnsigned(true); 1345 DesignatedEndIndex.setIsUnsigned(true); 1346 } 1347 1348 // Make sure that our non-designated initializer list has space 1349 // for a subobject corresponding to this array element. 1350 if (DesignatedEndIndex.getZExtValue() >= StructuredList->getNumInits()) 1351 StructuredList->resizeInits(SemaRef.Context, 1352 DesignatedEndIndex.getZExtValue() + 1); 1353 1354 // Repeatedly perform subobject initializations in the range 1355 // [DesignatedStartIndex, DesignatedEndIndex]. 1356 1357 // Move to the next designator 1358 unsigned ElementIndex = DesignatedStartIndex.getZExtValue(); 1359 unsigned OldIndex = Index; 1360 ++D; 1361 while (DesignatedStartIndex <= DesignatedEndIndex) { 1362 // Recurse to check later designated subobjects. 1363 QualType ElementType = AT->getElementType(); 1364 Index = OldIndex; 1365 if (CheckDesignatedInitializer(IList, DIE, D, ElementType, 0, 0, Index, 1366 StructuredList, ElementIndex, 1367 (DesignatedStartIndex == DesignatedEndIndex), 1368 false)) 1369 return true; 1370 1371 // Move to the next index in the array that we'll be initializing. 1372 ++DesignatedStartIndex; 1373 ElementIndex = DesignatedStartIndex.getZExtValue(); 1374 } 1375 1376 // If this the first designator, our caller will continue checking 1377 // the rest of this array subobject. 1378 if (IsFirstDesignator) { 1379 if (NextElementIndex) 1380 *NextElementIndex = DesignatedStartIndex; 1381 StructuredIndex = ElementIndex; 1382 return false; 1383 } 1384 1385 if (!FinishSubobjectInit) 1386 return false; 1387 1388 // Check the remaining elements within this array subobject. 1389 bool prevHadError = hadError; 1390 CheckArrayType(IList, CurrentObjectType, DesignatedStartIndex, false, Index, 1391 StructuredList, ElementIndex); 1392 return hadError && !prevHadError; 1393} 1394 1395// Get the structured initializer list for a subobject of type 1396// @p CurrentObjectType. 1397InitListExpr * 1398InitListChecker::getStructuredSubobjectInit(InitListExpr *IList, unsigned Index, 1399 QualType CurrentObjectType, 1400 InitListExpr *StructuredList, 1401 unsigned StructuredIndex, 1402 SourceRange InitRange) { 1403 Expr *ExistingInit = 0; 1404 if (!StructuredList) 1405 ExistingInit = SyntacticToSemantic[IList]; 1406 else if (StructuredIndex < StructuredList->getNumInits()) 1407 ExistingInit = StructuredList->getInit(StructuredIndex); 1408 1409 if (InitListExpr *Result = dyn_cast_or_null<InitListExpr>(ExistingInit)) 1410 return Result; 1411 1412 if (ExistingInit) { 1413 // We are creating an initializer list that initializes the 1414 // subobjects of the current object, but there was already an 1415 // initialization that completely initialized the current 1416 // subobject, e.g., by a compound literal: 1417 // 1418 // struct X { int a, b; }; 1419 // struct X xs[] = { [0] = (struct X) { 1, 2 }, [0].b = 3 }; 1420 // 1421 // Here, xs[0].a == 0 and xs[0].b == 3, since the second, 1422 // designated initializer re-initializes the whole 1423 // subobject [0], overwriting previous initializers. 1424 SemaRef.Diag(InitRange.getBegin(), diag::warn_subobject_initializer_overrides) 1425 << InitRange; 1426 SemaRef.Diag(ExistingInit->getSourceRange().getBegin(), 1427 diag::note_previous_initializer) 1428 << /*FIXME:has side effects=*/0 1429 << ExistingInit->getSourceRange(); 1430 } 1431 1432 SourceLocation StartLoc; 1433 if (Index < IList->getNumInits()) 1434 StartLoc = IList->getInit(Index)->getSourceRange().getBegin(); 1435 InitListExpr *Result 1436 = new (SemaRef.Context) InitListExpr(StartLoc, 0, 0, 1437 IList->getSourceRange().getEnd()); 1438 Result->setType(CurrentObjectType); 1439 1440 // Link this new initializer list into the structured initializer 1441 // lists. 1442 if (StructuredList) 1443 StructuredList->updateInit(StructuredIndex, Result); 1444 else { 1445 Result->setSyntacticForm(IList); 1446 SyntacticToSemantic[IList] = Result; 1447 } 1448 1449 return Result; 1450} 1451 1452/// Update the initializer at index @p StructuredIndex within the 1453/// structured initializer list to the value @p expr. 1454void InitListChecker::UpdateStructuredListElement(InitListExpr *StructuredList, 1455 unsigned &StructuredIndex, 1456 Expr *expr) { 1457 // No structured initializer list to update 1458 if (!StructuredList) 1459 return; 1460 1461 if (Expr *PrevInit = StructuredList->updateInit(StructuredIndex, expr)) { 1462 // This initializer overwrites a previous initializer. Warn. 1463 SemaRef.Diag(expr->getSourceRange().getBegin(), 1464 diag::warn_initializer_overrides) 1465 << expr->getSourceRange(); 1466 SemaRef.Diag(PrevInit->getSourceRange().getBegin(), 1467 diag::note_previous_initializer) 1468 << /*FIXME:has side effects=*/0 1469 << PrevInit->getSourceRange(); 1470 } 1471 1472 ++StructuredIndex; 1473} 1474 1475/// Check that the given Index expression is a valid array designator 1476/// value. This is essentailly just a wrapper around 1477/// Expr::isIntegerConstantExpr that also checks for negative values 1478/// and produces a reasonable diagnostic if there is a 1479/// failure. Returns true if there was an error, false otherwise. If 1480/// everything went okay, Value will receive the value of the constant 1481/// expression. 1482static bool 1483CheckArrayDesignatorExpr(Sema &Self, Expr *Index, llvm::APSInt &Value) { 1484 SourceLocation Loc = Index->getSourceRange().getBegin(); 1485 1486 // Make sure this is an integer constant expression. 1487 if (!Index->isIntegerConstantExpr(Value, Self.Context, &Loc)) 1488 return Self.Diag(Loc, diag::err_array_designator_nonconstant) 1489 << Index->getSourceRange(); 1490 1491 // Make sure this constant expression is non-negative. 1492 llvm::APSInt Zero(llvm::APSInt::getNullValue(Value.getBitWidth()), 1493 Value.isUnsigned()); 1494 if (Value < Zero) 1495 return Self.Diag(Loc, diag::err_array_designator_negative) 1496 << Value.toString(10) << Index->getSourceRange(); 1497 1498 Value.setIsUnsigned(true); 1499 return false; 1500} 1501 1502Sema::OwningExprResult Sema::ActOnDesignatedInitializer(Designation &Desig, 1503 SourceLocation Loc, 1504 bool UsedColonSyntax, 1505 OwningExprResult Init) { 1506 typedef DesignatedInitExpr::Designator ASTDesignator; 1507 1508 bool Invalid = false; 1509 llvm::SmallVector<ASTDesignator, 32> Designators; 1510 llvm::SmallVector<Expr *, 32> InitExpressions; 1511 1512 // Build designators and check array designator expressions. 1513 for (unsigned Idx = 0; Idx < Desig.getNumDesignators(); ++Idx) { 1514 const Designator &D = Desig.getDesignator(Idx); 1515 switch (D.getKind()) { 1516 case Designator::FieldDesignator: 1517 Designators.push_back(ASTDesignator(D.getField(), D.getDotLoc(), 1518 D.getFieldLoc())); 1519 break; 1520 1521 case Designator::ArrayDesignator: { 1522 Expr *Index = static_cast<Expr *>(D.getArrayIndex()); 1523 llvm::APSInt IndexValue; 1524 if (CheckArrayDesignatorExpr(*this, Index, IndexValue)) 1525 Invalid = true; 1526 else { 1527 Designators.push_back(ASTDesignator(InitExpressions.size(), 1528 D.getLBracketLoc(), 1529 D.getRBracketLoc())); 1530 InitExpressions.push_back(Index); 1531 } 1532 break; 1533 } 1534 1535 case Designator::ArrayRangeDesignator: { 1536 Expr *StartIndex = static_cast<Expr *>(D.getArrayRangeStart()); 1537 Expr *EndIndex = static_cast<Expr *>(D.getArrayRangeEnd()); 1538 llvm::APSInt StartValue; 1539 llvm::APSInt EndValue; 1540 if (CheckArrayDesignatorExpr(*this, StartIndex, StartValue) || 1541 CheckArrayDesignatorExpr(*this, EndIndex, EndValue)) 1542 Invalid = true; 1543 else { 1544 // Make sure we're comparing values with the same bit width. 1545 if (StartValue.getBitWidth() > EndValue.getBitWidth()) 1546 EndValue.extend(StartValue.getBitWidth()); 1547 else if (StartValue.getBitWidth() < EndValue.getBitWidth()) 1548 StartValue.extend(EndValue.getBitWidth()); 1549 1550 if (EndValue < StartValue) { 1551 Diag(D.getEllipsisLoc(), diag::err_array_designator_empty_range) 1552 << StartValue.toString(10) << EndValue.toString(10) 1553 << StartIndex->getSourceRange() << EndIndex->getSourceRange(); 1554 Invalid = true; 1555 } else { 1556 Designators.push_back(ASTDesignator(InitExpressions.size(), 1557 D.getLBracketLoc(), 1558 D.getEllipsisLoc(), 1559 D.getRBracketLoc())); 1560 InitExpressions.push_back(StartIndex); 1561 InitExpressions.push_back(EndIndex); 1562 } 1563 } 1564 break; 1565 } 1566 } 1567 } 1568 1569 if (Invalid || Init.isInvalid()) 1570 return ExprError(); 1571 1572 // Clear out the expressions within the designation. 1573 Desig.ClearExprs(*this); 1574 1575 DesignatedInitExpr *DIE 1576 = DesignatedInitExpr::Create(Context, &Designators[0], Designators.size(), 1577 &InitExpressions[0], InitExpressions.size(), 1578 Loc, UsedColonSyntax, 1579 static_cast<Expr *>(Init.release())); 1580 return Owned(DIE); 1581} 1582 1583bool Sema::CheckInitList(InitListExpr *&InitList, QualType &DeclType) { 1584 InitListChecker CheckInitList(*this, InitList, DeclType); 1585 if (!CheckInitList.HadError()) 1586 InitList = CheckInitList.getFullyStructuredList(); 1587 1588 return CheckInitList.HadError(); 1589} 1590 1591/// \brief Diagnose any semantic errors with value-initialization of 1592/// the given type. 1593/// 1594/// Value-initialization effectively zero-initializes any types 1595/// without user-declared constructors, and calls the default 1596/// constructor for a for any type that has a user-declared 1597/// constructor (C++ [dcl.init]p5). Value-initialization can fail when 1598/// a type with a user-declared constructor does not have an 1599/// accessible, non-deleted default constructor. In C, everything can 1600/// be value-initialized, which corresponds to C's notion of 1601/// initializing objects with static storage duration when no 1602/// initializer is provided for that object. 1603/// 1604/// \returns true if there was an error, false otherwise. 1605bool Sema::CheckValueInitialization(QualType Type, SourceLocation Loc) { 1606 // C++ [dcl.init]p5: 1607 // 1608 // To value-initialize an object of type T means: 1609 1610 // -- if T is an array type, then each element is value-initialized; 1611 if (const ArrayType *AT = Context.getAsArrayType(Type)) 1612 return CheckValueInitialization(AT->getElementType(), Loc); 1613 1614 if (const RecordType *RT = Type->getAsRecordType()) { 1615 if (CXXRecordDecl *ClassDecl = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 1616 // -- if T is a class type (clause 9) with a user-declared 1617 // constructor (12.1), then the default constructor for T is 1618 // called (and the initialization is ill-formed if T has no 1619 // accessible default constructor); 1620 if (ClassDecl->hasUserDeclaredConstructor()) 1621 // FIXME: Eventually, we'll need to put the constructor decl 1622 // into the AST. 1623 return PerformInitializationByConstructor(Type, 0, 0, Loc, 1624 SourceRange(Loc), 1625 DeclarationName(), 1626 IK_Direct); 1627 } 1628 } 1629 1630 if (Type->isReferenceType()) { 1631 // C++ [dcl.init]p5: 1632 // [...] A program that calls for default-initialization or 1633 // value-initialization of an entity of reference type is 1634 // ill-formed. [...] 1635 // FIXME: Once we have code that goes through this path, add an 1636 // actual diagnostic :) 1637 } 1638 1639 return false; 1640} 1641