1 //===--- Initialization.h - Semantic Analysis for Initializers --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file provides supporting data types for initialization of objects.
12 //===----------------------------------------------------------------------===//
13 #ifndef LLVM_CLANG_SEMA_INITIALIZATION_H
14 #define LLVM_CLANG_SEMA_INITIALIZATION_H
16 #include "clang/AST/ASTContext.h"
17 #include "clang/AST/Attr.h"
18 #include "clang/AST/Type.h"
19 #include "clang/AST/UnresolvedSet.h"
20 #include "clang/Basic/SourceLocation.h"
21 #include "clang/Sema/Overload.h"
22 #include "clang/Sema/Ownership.h"
23 #include "llvm/ADT/PointerIntPair.h"
24 #include "llvm/ADT/SmallVector.h"
29 class CXXBaseSpecifier;
40 /// \brief Describes an entity that is being initialized.
41 class InitializedEntity {
43 /// \brief Specifies the kind of entity being initialized.
45 /// \brief The entity being initialized is a variable.
47 /// \brief The entity being initialized is a function parameter.
49 /// \brief The entity being initialized is the result of a function call.
51 /// \brief The entity being initialized is an exception object that
54 /// \brief The entity being initialized is a non-static data member
57 /// \brief The entity being initialized is an element of an array.
59 /// \brief The entity being initialized is an object (or array of
60 /// objects) allocated via new.
62 /// \brief The entity being initialized is a temporary object.
64 /// \brief The entity being initialized is a base member subobject.
66 /// \brief The initialization is being done by a delegating constructor.
68 /// \brief The entity being initialized is an element of a vector.
71 /// \brief The entity being initialized is a field of block descriptor for
72 /// the copied-in c++ object.
74 /// \brief The entity being initialized is the real or imaginary part of a
77 /// \brief The entity being initialized is the field that captures a
78 /// variable in a lambda.
80 /// \brief The entity being initialized is the initializer for a compound
82 EK_CompoundLiteralInit,
83 /// \brief The entity being implicitly initialized back to the formal
86 /// \brief The entity being initialized is a function parameter; function
87 /// is member of group of audited CF APIs.
88 EK_Parameter_CF_Audited
90 // Note: err_init_conversion_failed in DiagnosticSemaKinds.td uses this
91 // enum as an index for its first %select. When modifying this list,
92 // that diagnostic text needs to be updated as well.
96 /// \brief The kind of entity being initialized.
99 /// \brief If non-NULL, the parent entity in which this
100 /// initialization occurs.
101 const InitializedEntity *Parent;
103 /// \brief The type of the object or reference being initialized.
106 /// \brief The mangling number for the next reference temporary to be created.
107 mutable unsigned ManglingNumber;
110 /// \brief When Kind == EK_Result, EK_Exception, EK_New, the
111 /// location of the 'return', 'throw', or 'new' keyword,
112 /// respectively. When Kind == EK_Temporary, the location where
113 /// the temporary is being created.
116 /// \brief Whether the entity being initialized may end up using the
117 /// named return value optimization (NRVO).
122 /// \brief The name of the variable being captured by an EK_LambdaCapture.
123 IdentifierInfo *VarID;
125 /// \brief The source location at which the capture occurs.
130 /// \brief When Kind == EK_Variable, or EK_Member, the VarDecl or
131 /// FieldDecl, respectively.
132 DeclaratorDecl *VariableOrMember;
134 /// \brief When Kind == EK_RelatedResult, the ObjectiveC method where
135 /// result type was implicitly changed to accommodate ARC semantics.
136 ObjCMethodDecl *MethodDecl;
138 /// \brief When Kind == EK_Parameter, the ParmVarDecl, with the
139 /// low bit indicating whether the parameter is "consumed".
142 /// \brief When Kind == EK_Temporary or EK_CompoundLiteralInit, the type
143 /// source information for the temporary.
144 TypeSourceInfo *TypeInfo;
146 struct LN LocAndNRVO;
148 /// \brief When Kind == EK_Base, the base specifier that provides the
149 /// base class. The lower bit specifies whether the base is an inherited
153 /// \brief When Kind == EK_ArrayElement, EK_VectorElement, or
154 /// EK_ComplexElement, the index of the array or vector element being
161 InitializedEntity() : ManglingNumber(0) {}
163 /// \brief Create the initialization entity for a variable.
164 InitializedEntity(VarDecl *Var)
165 : Kind(EK_Variable), Parent(nullptr), Type(Var->getType()),
166 ManglingNumber(0), VariableOrMember(Var) { }
168 /// \brief Create the initialization entity for the result of a
169 /// function, throwing an object, performing an explicit cast, or
170 /// initializing a parameter for which there is no declaration.
171 InitializedEntity(EntityKind Kind, SourceLocation Loc, QualType Type,
173 : Kind(Kind), Parent(nullptr), Type(Type), ManglingNumber(0)
175 LocAndNRVO.Location = Loc.getRawEncoding();
176 LocAndNRVO.NRVO = NRVO;
179 /// \brief Create the initialization entity for a member subobject.
180 InitializedEntity(FieldDecl *Member, const InitializedEntity *Parent)
181 : Kind(EK_Member), Parent(Parent), Type(Member->getType()),
182 ManglingNumber(0), VariableOrMember(Member) { }
184 /// \brief Create the initialization entity for an array element.
185 InitializedEntity(ASTContext &Context, unsigned Index,
186 const InitializedEntity &Parent);
188 /// \brief Create the initialization entity for a lambda capture.
189 InitializedEntity(IdentifierInfo *VarID, QualType FieldType, SourceLocation Loc)
190 : Kind(EK_LambdaCapture), Parent(nullptr), Type(FieldType),
193 Capture.VarID = VarID;
194 Capture.Location = Loc.getRawEncoding();
198 /// \brief Create the initialization entity for a variable.
199 static InitializedEntity InitializeVariable(VarDecl *Var) {
200 return InitializedEntity(Var);
203 /// \brief Create the initialization entity for a parameter.
204 static InitializedEntity InitializeParameter(ASTContext &Context,
206 return InitializeParameter(Context, Parm, Parm->getType());
209 /// \brief Create the initialization entity for a parameter, but use
211 static InitializedEntity InitializeParameter(ASTContext &Context,
214 bool Consumed = (Context.getLangOpts().ObjCAutoRefCount &&
215 Parm->hasAttr<NSConsumedAttr>());
217 InitializedEntity Entity;
218 Entity.Kind = EK_Parameter;
220 Context.getVariableArrayDecayedType(Type.getUnqualifiedType());
221 Entity.Parent = nullptr;
223 = (static_cast<uintptr_t>(Consumed) | reinterpret_cast<uintptr_t>(Parm));
227 /// \brief Create the initialization entity for a parameter that is
228 /// only known by its type.
229 static InitializedEntity InitializeParameter(ASTContext &Context,
232 InitializedEntity Entity;
233 Entity.Kind = EK_Parameter;
234 Entity.Type = Context.getVariableArrayDecayedType(Type);
235 Entity.Parent = nullptr;
236 Entity.Parameter = (Consumed);
240 /// \brief Create the initialization entity for the result of a function.
241 static InitializedEntity InitializeResult(SourceLocation ReturnLoc,
242 QualType Type, bool NRVO) {
243 return InitializedEntity(EK_Result, ReturnLoc, Type, NRVO);
246 static InitializedEntity InitializeBlock(SourceLocation BlockVarLoc,
247 QualType Type, bool NRVO) {
248 return InitializedEntity(EK_BlockElement, BlockVarLoc, Type, NRVO);
251 /// \brief Create the initialization entity for an exception object.
252 static InitializedEntity InitializeException(SourceLocation ThrowLoc,
253 QualType Type, bool NRVO) {
254 return InitializedEntity(EK_Exception, ThrowLoc, Type, NRVO);
257 /// \brief Create the initialization entity for an object allocated via new.
258 static InitializedEntity InitializeNew(SourceLocation NewLoc, QualType Type) {
259 return InitializedEntity(EK_New, NewLoc, Type);
262 /// \brief Create the initialization entity for a temporary.
263 static InitializedEntity InitializeTemporary(QualType Type) {
264 InitializedEntity Result(EK_Temporary, SourceLocation(), Type);
265 Result.TypeInfo = nullptr;
269 /// \brief Create the initialization entity for a temporary.
270 static InitializedEntity InitializeTemporary(TypeSourceInfo *TypeInfo) {
271 InitializedEntity Result(EK_Temporary, SourceLocation(),
272 TypeInfo->getType());
273 Result.TypeInfo = TypeInfo;
277 /// \brief Create the initialization entity for a related result.
278 static InitializedEntity InitializeRelatedResult(ObjCMethodDecl *MD,
280 InitializedEntity Result(EK_RelatedResult, SourceLocation(), Type);
281 Result.MethodDecl = MD;
286 /// \brief Create the initialization entity for a base class subobject.
287 static InitializedEntity
288 InitializeBase(ASTContext &Context, const CXXBaseSpecifier *Base,
289 bool IsInheritedVirtualBase,
290 const InitializedEntity *Parent = nullptr);
292 /// \brief Create the initialization entity for a delegated constructor.
293 static InitializedEntity InitializeDelegation(QualType Type) {
294 return InitializedEntity(EK_Delegating, SourceLocation(), Type);
297 /// \brief Create the initialization entity for a member subobject.
298 static InitializedEntity
299 InitializeMember(FieldDecl *Member,
300 const InitializedEntity *Parent = nullptr) {
301 return InitializedEntity(Member, Parent);
304 /// \brief Create the initialization entity for a member subobject.
305 static InitializedEntity
306 InitializeMember(IndirectFieldDecl *Member,
307 const InitializedEntity *Parent = nullptr) {
308 return InitializedEntity(Member->getAnonField(), Parent);
311 /// \brief Create the initialization entity for an array element.
312 static InitializedEntity InitializeElement(ASTContext &Context,
314 const InitializedEntity &Parent) {
315 return InitializedEntity(Context, Index, Parent);
318 /// \brief Create the initialization entity for a lambda capture.
319 static InitializedEntity InitializeLambdaCapture(IdentifierInfo *VarID,
321 SourceLocation Loc) {
322 return InitializedEntity(VarID, FieldType, Loc);
325 /// \brief Create the entity for a compound literal initializer.
326 static InitializedEntity InitializeCompoundLiteralInit(TypeSourceInfo *TSI) {
327 InitializedEntity Result(EK_CompoundLiteralInit, SourceLocation(),
329 Result.TypeInfo = TSI;
334 /// \brief Determine the kind of initialization.
335 EntityKind getKind() const { return Kind; }
337 /// \brief Retrieve the parent of the entity being initialized, when
338 /// the initialization itself is occurring within the context of a
339 /// larger initialization.
340 const InitializedEntity *getParent() const { return Parent; }
342 /// \brief Retrieve type being initialized.
343 QualType getType() const { return Type; }
345 /// \brief Retrieve complete type-source information for the object being
346 /// constructed, if known.
347 TypeSourceInfo *getTypeSourceInfo() const {
348 if (Kind == EK_Temporary || Kind == EK_CompoundLiteralInit)
354 /// \brief Retrieve the name of the entity being initialized.
355 DeclarationName getName() const;
357 /// \brief Retrieve the variable, parameter, or field being
359 DeclaratorDecl *getDecl() const;
361 /// \brief Retrieve the ObjectiveC method being initialized.
362 ObjCMethodDecl *getMethodDecl() const { return MethodDecl; }
364 /// \brief Determine whether this initialization allows the named return
365 /// value optimization, which also applies to thrown objects.
366 bool allowsNRVO() const;
368 bool isParameterKind() const {
369 return (getKind() == EK_Parameter ||
370 getKind() == EK_Parameter_CF_Audited);
372 /// \brief Determine whether this initialization consumes the
374 bool isParameterConsumed() const {
375 assert(isParameterKind() && "Not a parameter");
376 return (Parameter & 1);
379 /// \brief Retrieve the base specifier.
380 const CXXBaseSpecifier *getBaseSpecifier() const {
381 assert(getKind() == EK_Base && "Not a base specifier");
382 return reinterpret_cast<const CXXBaseSpecifier *>(Base & ~0x1);
385 /// \brief Return whether the base is an inherited virtual base.
386 bool isInheritedVirtualBase() const {
387 assert(getKind() == EK_Base && "Not a base specifier");
391 /// \brief Determine the location of the 'return' keyword when initializing
392 /// the result of a function call.
393 SourceLocation getReturnLoc() const {
394 assert(getKind() == EK_Result && "No 'return' location!");
395 return SourceLocation::getFromRawEncoding(LocAndNRVO.Location);
398 /// \brief Determine the location of the 'throw' keyword when initializing
399 /// an exception object.
400 SourceLocation getThrowLoc() const {
401 assert(getKind() == EK_Exception && "No 'throw' location!");
402 return SourceLocation::getFromRawEncoding(LocAndNRVO.Location);
405 /// \brief If this is an array, vector, or complex number element, get the
407 unsigned getElementIndex() const {
408 assert(getKind() == EK_ArrayElement || getKind() == EK_VectorElement ||
409 getKind() == EK_ComplexElement);
412 /// \brief If this is already the initializer for an array or vector
413 /// element, sets the element index.
414 void setElementIndex(unsigned Index) {
415 assert(getKind() == EK_ArrayElement || getKind() == EK_VectorElement ||
416 getKind() == EK_ComplexElement);
419 /// \brief For a lambda capture, return the capture's name.
420 StringRef getCapturedVarName() const {
421 assert(getKind() == EK_LambdaCapture && "Not a lambda capture!");
422 return Capture.VarID->getName();
424 /// \brief Determine the location of the capture when initializing
425 /// field from a captured variable in a lambda.
426 SourceLocation getCaptureLoc() const {
427 assert(getKind() == EK_LambdaCapture && "Not a lambda capture!");
428 return SourceLocation::getFromRawEncoding(Capture.Location);
431 void setParameterCFAudited() {
432 Kind = EK_Parameter_CF_Audited;
435 unsigned allocateManglingNumber() const { return ++ManglingNumber; }
437 /// Dump a representation of the initialized entity to standard error,
438 /// for debugging purposes.
442 unsigned dumpImpl(raw_ostream &OS) const;
445 /// \brief Describes the kind of initialization being performed, along with
446 /// location information for tokens related to the initialization (equal sign,
448 class InitializationKind {
450 /// \brief The kind of initialization being performed.
452 IK_Direct, ///< Direct initialization
453 IK_DirectList, ///< Direct list-initialization
454 IK_Copy, ///< Copy initialization
455 IK_Default, ///< Default initialization
456 IK_Value ///< Value initialization
460 /// \brief The context of the initialization.
462 IC_Normal, ///< Normal context
463 IC_ExplicitConvs, ///< Normal context, but allows explicit conversion funcs
464 IC_Implicit, ///< Implicit context (value initialization)
465 IC_StaticCast, ///< Static cast context
466 IC_CStyleCast, ///< C-style cast context
467 IC_FunctionalCast ///< Functional cast context
470 /// \brief The kind of initialization being performed.
473 /// \brief The context of the initialization.
474 InitContext Context : 8;
476 /// \brief The source locations involved in the initialization.
477 SourceLocation Locations[3];
479 InitializationKind(InitKind Kind, InitContext Context, SourceLocation Loc1,
480 SourceLocation Loc2, SourceLocation Loc3)
481 : Kind(Kind), Context(Context)
489 /// \brief Create a direct initialization.
490 static InitializationKind CreateDirect(SourceLocation InitLoc,
491 SourceLocation LParenLoc,
492 SourceLocation RParenLoc) {
493 return InitializationKind(IK_Direct, IC_Normal,
494 InitLoc, LParenLoc, RParenLoc);
497 static InitializationKind CreateDirectList(SourceLocation InitLoc) {
498 return InitializationKind(IK_DirectList, IC_Normal,
499 InitLoc, InitLoc, InitLoc);
502 /// \brief Create a direct initialization due to a cast that isn't a C-style
503 /// or functional cast.
504 static InitializationKind CreateCast(SourceRange TypeRange) {
505 return InitializationKind(IK_Direct, IC_StaticCast, TypeRange.getBegin(),
506 TypeRange.getBegin(), TypeRange.getEnd());
509 /// \brief Create a direct initialization for a C-style cast.
510 static InitializationKind CreateCStyleCast(SourceLocation StartLoc,
511 SourceRange TypeRange,
513 // C++ cast syntax doesn't permit init lists, but C compound literals are
515 return InitializationKind(InitList ? IK_DirectList : IK_Direct,
516 IC_CStyleCast, StartLoc, TypeRange.getBegin(),
520 /// \brief Create a direct initialization for a functional cast.
521 static InitializationKind CreateFunctionalCast(SourceRange TypeRange,
523 return InitializationKind(InitList ? IK_DirectList : IK_Direct,
524 IC_FunctionalCast, TypeRange.getBegin(),
525 TypeRange.getBegin(), TypeRange.getEnd());
528 /// \brief Create a copy initialization.
529 static InitializationKind CreateCopy(SourceLocation InitLoc,
530 SourceLocation EqualLoc,
531 bool AllowExplicitConvs = false) {
532 return InitializationKind(IK_Copy,
533 AllowExplicitConvs? IC_ExplicitConvs : IC_Normal,
534 InitLoc, EqualLoc, EqualLoc);
537 /// \brief Create a default initialization.
538 static InitializationKind CreateDefault(SourceLocation InitLoc) {
539 return InitializationKind(IK_Default, IC_Normal, InitLoc, InitLoc, InitLoc);
542 /// \brief Create a value initialization.
543 static InitializationKind CreateValue(SourceLocation InitLoc,
544 SourceLocation LParenLoc,
545 SourceLocation RParenLoc,
546 bool isImplicit = false) {
547 return InitializationKind(IK_Value, isImplicit ? IC_Implicit : IC_Normal,
548 InitLoc, LParenLoc, RParenLoc);
551 /// \brief Determine the initialization kind.
552 InitKind getKind() const {
556 /// \brief Determine whether this initialization is an explicit cast.
557 bool isExplicitCast() const {
558 return Context >= IC_StaticCast;
561 /// \brief Determine whether this initialization is a C-style cast.
562 bool isCStyleOrFunctionalCast() const {
563 return Context >= IC_CStyleCast;
566 /// \brief Determine whether this is a C-style cast.
567 bool isCStyleCast() const {
568 return Context == IC_CStyleCast;
571 /// \brief Determine whether this is a functional-style cast.
572 bool isFunctionalCast() const {
573 return Context == IC_FunctionalCast;
576 /// \brief Determine whether this initialization is an implicit
577 /// value-initialization, e.g., as occurs during aggregate
579 bool isImplicitValueInit() const { return Context == IC_Implicit; }
581 /// \brief Retrieve the location at which initialization is occurring.
582 SourceLocation getLocation() const { return Locations[0]; }
584 /// \brief Retrieve the source range that covers the initialization.
585 SourceRange getRange() const {
586 return SourceRange(Locations[0], Locations[2]);
589 /// \brief Retrieve the location of the equal sign for copy initialization
591 SourceLocation getEqualLoc() const {
592 assert(Kind == IK_Copy && "Only copy initialization has an '='");
596 bool isCopyInit() const { return Kind == IK_Copy; }
598 /// \brief Retrieve whether this initialization allows the use of explicit
600 bool AllowExplicit() const { return !isCopyInit(); }
602 /// \brief Retrieve whether this initialization allows the use of explicit
603 /// conversion functions when binding a reference. If the reference is the
604 /// first parameter in a copy or move constructor, such conversions are
605 /// permitted even though we are performing copy-initialization.
606 bool allowExplicitConversionFunctionsInRefBinding() const {
607 return !isCopyInit() || Context == IC_ExplicitConvs;
610 /// \brief Retrieve the source range containing the locations of the open
611 /// and closing parentheses for value and direct initializations.
612 SourceRange getParenRange() const {
613 assert((Kind == IK_Direct || Kind == IK_Value) &&
614 "Only direct- and value-initialization have parentheses");
615 return SourceRange(Locations[1], Locations[2]);
619 /// \brief Describes the sequence of initializations required to initialize
620 /// a given object or reference with a set of arguments.
621 class InitializationSequence {
623 /// \brief Describes the kind of initialization sequence computed.
625 /// \brief A failed initialization sequence. The failure kind tells what
629 /// \brief A dependent initialization, which could not be
630 /// type-checked due to the presence of dependent types or
631 /// dependently-typed expressions.
634 /// \brief A normal sequence.
638 /// \brief Describes the kind of a particular step in an initialization
641 /// \brief Resolve the address of an overloaded function to a specific
642 /// function declaration.
643 SK_ResolveAddressOfOverloadedFunction,
644 /// \brief Perform a derived-to-base cast, producing an rvalue.
645 SK_CastDerivedToBaseRValue,
646 /// \brief Perform a derived-to-base cast, producing an xvalue.
647 SK_CastDerivedToBaseXValue,
648 /// \brief Perform a derived-to-base cast, producing an lvalue.
649 SK_CastDerivedToBaseLValue,
650 /// \brief Reference binding to an lvalue.
652 /// \brief Reference binding to a temporary.
653 SK_BindReferenceToTemporary,
654 /// \brief An optional copy of a temporary object to another
655 /// temporary object, which is permitted (but not required) by
656 /// C++98/03 but not C++0x.
657 SK_ExtraneousCopyToTemporary,
658 /// \brief Perform a user-defined conversion, either via a conversion
659 /// function or via a constructor.
661 /// \brief Perform a qualification conversion, producing an rvalue.
662 SK_QualificationConversionRValue,
663 /// \brief Perform a qualification conversion, producing an xvalue.
664 SK_QualificationConversionXValue,
665 /// \brief Perform a qualification conversion, producing an lvalue.
666 SK_QualificationConversionLValue,
667 /// \brief Perform a conversion adding _Atomic to a type.
669 /// \brief Perform a load from a glvalue, producing an rvalue.
671 /// \brief Perform an implicit conversion sequence.
672 SK_ConversionSequence,
673 /// \brief Perform an implicit conversion sequence without narrowing.
674 SK_ConversionSequenceNoNarrowing,
675 /// \brief Perform list-initialization without a constructor.
676 SK_ListInitialization,
677 /// \brief Unwrap the single-element initializer list for a reference.
679 /// \brief Rewrap the single-element initializer list for a reference.
681 /// \brief Perform initialization via a constructor.
682 SK_ConstructorInitialization,
683 /// \brief Perform initialization via a constructor, taking arguments from
684 /// a single InitListExpr.
685 SK_ConstructorInitializationFromList,
686 /// \brief Zero-initialize the object
687 SK_ZeroInitialization,
688 /// \brief C assignment
690 /// \brief Initialization by string
692 /// \brief An initialization that "converts" an Objective-C object
693 /// (not a point to an object) to another Objective-C object type.
694 SK_ObjCObjectConversion,
695 /// \brief Array initialization (from an array rvalue).
696 /// This is a GNU C extension.
698 /// \brief Array initialization from a parenthesized initializer list.
699 /// This is a GNU C++ extension.
700 SK_ParenthesizedArrayInit,
701 /// \brief Pass an object by indirect copy-and-restore.
702 SK_PassByIndirectCopyRestore,
703 /// \brief Pass an object by indirect restore.
704 SK_PassByIndirectRestore,
705 /// \brief Produce an Objective-C object pointer.
706 SK_ProduceObjCObject,
707 /// \brief Construct a std::initializer_list from an initializer list.
708 SK_StdInitializerList,
709 /// \brief Perform initialization via a constructor taking a single
710 /// std::initializer_list argument.
711 SK_StdInitializerListConstructorCall,
712 /// \brief Initialize an OpenCL sampler from an integer.
714 /// \brief Passing zero to a function where OpenCL event_t is expected.
718 /// \brief A single step in the initialization sequence.
721 /// \brief The kind of conversion or initialization step we are taking.
724 // \brief The type that results from this initialization.
728 bool HadMultipleCandidates;
729 FunctionDecl *Function;
730 DeclAccessPair FoundDecl;
734 /// \brief When Kind == SK_ResolvedOverloadedFunction or Kind ==
735 /// SK_UserConversion, the function that the expression should be
736 /// resolved to or the conversion function to call, respectively.
737 /// When Kind == SK_ConstructorInitialization or SK_ListConstruction,
738 /// the constructor to be called.
740 /// Always a FunctionDecl, plus a Boolean flag telling if it was
741 /// selected from an overloaded set having size greater than 1.
742 /// For conversion decls, the naming class is the source type.
743 /// For construct decls, the naming class is the target type.
746 /// \brief When Kind = SK_ConversionSequence, the implicit conversion
748 ImplicitConversionSequence *ICS;
750 /// \brief When Kind = SK_RewrapInitList, the syntactic form of the
752 InitListExpr *WrappingSyntacticList;
759 /// \brief The kind of initialization sequence computed.
760 enum SequenceKind SequenceKind;
762 /// \brief Steps taken by this initialization.
763 SmallVector<Step, 4> Steps;
766 /// \brief Describes why initialization failed.
768 /// \brief Too many initializers provided for a reference.
769 FK_TooManyInitsForReference,
770 /// \brief Array must be initialized with an initializer list.
771 FK_ArrayNeedsInitList,
772 /// \brief Array must be initialized with an initializer list or a
774 FK_ArrayNeedsInitListOrStringLiteral,
775 /// \brief Array must be initialized with an initializer list or a
776 /// wide string literal.
777 FK_ArrayNeedsInitListOrWideStringLiteral,
778 /// \brief Initializing a wide char array with narrow string literal.
779 FK_NarrowStringIntoWideCharArray,
780 /// \brief Initializing char array with wide string literal.
781 FK_WideStringIntoCharArray,
782 /// \brief Initializing wide char array with incompatible wide string
784 FK_IncompatWideStringIntoWideChar,
785 /// \brief Array type mismatch.
786 FK_ArrayTypeMismatch,
787 /// \brief Non-constant array initializer
788 FK_NonConstantArrayInit,
789 /// \brief Cannot resolve the address of an overloaded function.
790 FK_AddressOfOverloadFailed,
791 /// \brief Overloading due to reference initialization failed.
792 FK_ReferenceInitOverloadFailed,
793 /// \brief Non-const lvalue reference binding to a temporary.
794 FK_NonConstLValueReferenceBindingToTemporary,
795 /// \brief Non-const lvalue reference binding to an lvalue of unrelated
797 FK_NonConstLValueReferenceBindingToUnrelated,
798 /// \brief Rvalue reference binding to an lvalue.
799 FK_RValueReferenceBindingToLValue,
800 /// \brief Reference binding drops qualifiers.
801 FK_ReferenceInitDropsQualifiers,
802 /// \brief Reference binding failed.
803 FK_ReferenceInitFailed,
804 /// \brief Implicit conversion failed.
806 /// \brief Implicit conversion failed.
807 FK_ConversionFromPropertyFailed,
808 /// \brief Too many initializers for scalar
809 FK_TooManyInitsForScalar,
810 /// \brief Reference initialization from an initializer list
811 FK_ReferenceBindingToInitList,
812 /// \brief Initialization of some unused destination type with an
813 /// initializer list.
814 FK_InitListBadDestinationType,
815 /// \brief Overloading for a user-defined conversion failed.
816 FK_UserConversionOverloadFailed,
817 /// \brief Overloading for initialization by constructor failed.
818 FK_ConstructorOverloadFailed,
819 /// \brief Overloading for list-initialization by constructor failed.
820 FK_ListConstructorOverloadFailed,
821 /// \brief Default-initialization of a 'const' object.
822 FK_DefaultInitOfConst,
823 /// \brief Initialization of an incomplete type.
825 /// \brief Variable-length array must not have an initializer.
826 FK_VariableLengthArrayHasInitializer,
827 /// \brief List initialization failed at some point.
828 FK_ListInitializationFailed,
829 /// \brief Initializer has a placeholder type which cannot be
830 /// resolved by initialization.
832 /// \brief Trying to take the address of a function that doesn't support
833 /// having its address taken.
834 FK_AddressOfUnaddressableFunction,
835 /// \brief List-copy-initialization chose an explicit constructor.
836 FK_ExplicitConstructor
840 /// \brief The reason why initialization failed.
843 /// \brief The failed result of overload resolution.
844 OverloadingResult FailedOverloadResult;
846 /// \brief The candidate set created when initialization failed.
847 OverloadCandidateSet FailedCandidateSet;
849 /// \brief The incomplete type that caused a failure.
850 QualType FailedIncompleteType;
852 /// \brief The fixit that needs to be applied to make this initialization
854 std::string ZeroInitializationFixit;
855 SourceLocation ZeroInitializationFixitLoc;
858 /// \brief Call for initializations are invalid but that would be valid
859 /// zero initialzations if Fixit was applied.
860 void SetZeroInitializationFixit(const std::string& Fixit, SourceLocation L) {
861 ZeroInitializationFixit = Fixit;
862 ZeroInitializationFixitLoc = L;
867 /// \brief Prints a follow-up note that highlights the location of
868 /// the initialized entity, if it's remote.
869 void PrintInitLocationNote(Sema &S, const InitializedEntity &Entity);
872 /// \brief Try to perform initialization of the given entity, creating a
873 /// record of the steps required to perform the initialization.
875 /// The generated initialization sequence will either contain enough
876 /// information to diagnose
878 /// \param S the semantic analysis object.
880 /// \param Entity the entity being initialized.
882 /// \param Kind the kind of initialization being performed.
884 /// \param Args the argument(s) provided for initialization.
886 /// \param TopLevelOfInitList true if we are initializing from an expression
887 /// at the top level inside an initializer list. This disallows
888 /// narrowing conversions in C++11 onwards.
889 /// \param TreatUnavailableAsInvalid true if we want to treat unavailable
891 InitializationSequence(Sema &S,
892 const InitializedEntity &Entity,
893 const InitializationKind &Kind,
895 bool TopLevelOfInitList = false,
896 bool TreatUnavailableAsInvalid = true);
897 void InitializeFrom(Sema &S, const InitializedEntity &Entity,
898 const InitializationKind &Kind, MultiExprArg Args,
899 bool TopLevelOfInitList, bool TreatUnavailableAsInvalid);
901 ~InitializationSequence();
903 /// \brief Perform the actual initialization of the given entity based on
904 /// the computed initialization sequence.
906 /// \param S the semantic analysis object.
908 /// \param Entity the entity being initialized.
910 /// \param Kind the kind of initialization being performed.
912 /// \param Args the argument(s) provided for initialization, ownership of
913 /// which is transferred into the routine.
915 /// \param ResultType if non-NULL, will be set to the type of the
916 /// initialized object, which is the type of the declaration in most
917 /// cases. However, when the initialized object is a variable of
918 /// incomplete array type and the initializer is an initializer
919 /// list, this type will be set to the completed array type.
921 /// \returns an expression that performs the actual object initialization, if
922 /// the initialization is well-formed. Otherwise, emits diagnostics
923 /// and returns an invalid expression.
924 ExprResult Perform(Sema &S,
925 const InitializedEntity &Entity,
926 const InitializationKind &Kind,
928 QualType *ResultType = nullptr);
930 /// \brief Diagnose an potentially-invalid initialization sequence.
932 /// \returns true if the initialization sequence was ill-formed,
934 bool Diagnose(Sema &S,
935 const InitializedEntity &Entity,
936 const InitializationKind &Kind,
937 ArrayRef<Expr *> Args);
939 /// \brief Determine the kind of initialization sequence computed.
940 enum SequenceKind getKind() const { return SequenceKind; }
942 /// \brief Set the kind of sequence computed.
943 void setSequenceKind(enum SequenceKind SK) { SequenceKind = SK; }
945 /// \brief Determine whether the initialization sequence is valid.
946 explicit operator bool() const { return !Failed(); }
948 /// \brief Determine whether the initialization sequence is invalid.
949 bool Failed() const { return SequenceKind == FailedSequence; }
951 typedef SmallVectorImpl<Step>::const_iterator step_iterator;
952 step_iterator step_begin() const { return Steps.begin(); }
953 step_iterator step_end() const { return Steps.end(); }
955 typedef llvm::iterator_range<step_iterator> step_range;
956 step_range steps() const { return {step_begin(), step_end()}; }
958 /// \brief Determine whether this initialization is a direct reference
959 /// binding (C++ [dcl.init.ref]).
960 bool isDirectReferenceBinding() const;
962 /// \brief Determine whether this initialization failed due to an ambiguity.
963 bool isAmbiguous() const;
965 /// \brief Determine whether this initialization is direct call to a
967 bool isConstructorInitialization() const;
969 /// \brief Returns whether the last step in this initialization sequence is a
970 /// narrowing conversion, defined by C++0x [dcl.init.list]p7.
972 /// If this function returns true, *isInitializerConstant will be set to
973 /// describe whether *Initializer was a constant expression. If
974 /// *isInitializerConstant is set to true, *ConstantValue will be set to the
975 /// evaluated value of *Initializer.
976 bool endsWithNarrowing(ASTContext &Ctx, const Expr *Initializer,
977 bool *isInitializerConstant,
978 APValue *ConstantValue) const;
980 /// \brief Add a new step in the initialization that resolves the address
981 /// of an overloaded function to a specific function declaration.
983 /// \param Function the function to which the overloaded function reference
985 void AddAddressOverloadResolutionStep(FunctionDecl *Function,
986 DeclAccessPair Found,
987 bool HadMultipleCandidates);
989 /// \brief Add a new step in the initialization that performs a derived-to-
992 /// \param BaseType the base type to which we will be casting.
994 /// \param Category Indicates whether the result will be treated as an
995 /// rvalue, an xvalue, or an lvalue.
996 void AddDerivedToBaseCastStep(QualType BaseType,
997 ExprValueKind Category);
999 /// \brief Add a new step binding a reference to an object.
1001 /// \param BindingTemporary True if we are binding a reference to a temporary
1002 /// object (thereby extending its lifetime); false if we are binding to an
1003 /// lvalue or an lvalue treated as an rvalue.
1004 void AddReferenceBindingStep(QualType T, bool BindingTemporary);
1006 /// \brief Add a new step that makes an extraneous copy of the input
1007 /// to a temporary of the same class type.
1009 /// This extraneous copy only occurs during reference binding in
1010 /// C++98/03, where we are permitted (but not required) to introduce
1011 /// an extra copy. At a bare minimum, we must check that we could
1012 /// call the copy constructor, and produce a diagnostic if the copy
1013 /// constructor is inaccessible or no copy constructor matches.
1015 /// \param T The type of the temporary being created.
1016 void AddExtraneousCopyToTemporary(QualType T);
1018 /// \brief Add a new step invoking a conversion function, which is either
1019 /// a constructor or a conversion function.
1020 void AddUserConversionStep(FunctionDecl *Function,
1021 DeclAccessPair FoundDecl,
1023 bool HadMultipleCandidates);
1025 /// \brief Add a new step that performs a qualification conversion to the
1027 void AddQualificationConversionStep(QualType Ty,
1028 ExprValueKind Category);
1030 /// \brief Add a new step that performs conversion from non-atomic to atomic
1032 void AddAtomicConversionStep(QualType Ty);
1034 /// \brief Add a new step that performs a load of the given type.
1036 /// Although the term "LValueToRValue" is conventional, this applies to both
1037 /// lvalues and xvalues.
1038 void AddLValueToRValueStep(QualType Ty);
1040 /// \brief Add a new step that applies an implicit conversion sequence.
1041 void AddConversionSequenceStep(const ImplicitConversionSequence &ICS,
1042 QualType T, bool TopLevelOfInitList = false);
1044 /// \brief Add a list-initialization step.
1045 void AddListInitializationStep(QualType T);
1047 /// \brief Add a constructor-initialization step.
1049 /// \param FromInitList The constructor call is syntactically an initializer
1051 /// \param AsInitList The constructor is called as an init list constructor.
1052 void AddConstructorInitializationStep(DeclAccessPair FoundDecl,
1053 CXXConstructorDecl *Constructor,
1055 bool HadMultipleCandidates,
1056 bool FromInitList, bool AsInitList);
1058 /// \brief Add a zero-initialization step.
1059 void AddZeroInitializationStep(QualType T);
1061 /// \brief Add a C assignment step.
1063 // FIXME: It isn't clear whether this should ever be needed;
1064 // ideally, we would handle everything needed in C in the common
1065 // path. However, that isn't the case yet.
1066 void AddCAssignmentStep(QualType T);
1068 /// \brief Add a string init step.
1069 void AddStringInitStep(QualType T);
1071 /// \brief Add an Objective-C object conversion step, which is
1073 void AddObjCObjectConversionStep(QualType T);
1075 /// \brief Add an array initialization step.
1076 void AddArrayInitStep(QualType T);
1078 /// \brief Add a parenthesized array initialization step.
1079 void AddParenthesizedArrayInitStep(QualType T);
1081 /// \brief Add a step to pass an object by indirect copy-restore.
1082 void AddPassByIndirectCopyRestoreStep(QualType T, bool shouldCopy);
1084 /// \brief Add a step to "produce" an Objective-C object (by
1086 void AddProduceObjCObjectStep(QualType T);
1088 /// \brief Add a step to construct a std::initializer_list object from an
1089 /// initializer list.
1090 void AddStdInitializerListConstructionStep(QualType T);
1092 /// \brief Add a step to initialize an OpenCL sampler from an integer
1094 void AddOCLSamplerInitStep(QualType T);
1096 /// \brief Add a step to initialize an OpenCL event_t from a NULL
1098 void AddOCLZeroEventStep(QualType T);
1100 /// \brief Add steps to unwrap a initializer list for a reference around a
1101 /// single element and rewrap it at the end.
1102 void RewrapReferenceInitList(QualType T, InitListExpr *Syntactic);
1104 /// \brief Note that this initialization sequence failed.
1105 void SetFailed(FailureKind Failure) {
1106 SequenceKind = FailedSequence;
1107 this->Failure = Failure;
1108 assert((Failure != FK_Incomplete || !FailedIncompleteType.isNull()) &&
1109 "Incomplete type failure requires a type!");
1112 /// \brief Note that this initialization sequence failed due to failed
1113 /// overload resolution.
1114 void SetOverloadFailure(FailureKind Failure, OverloadingResult Result);
1116 /// \brief Retrieve a reference to the candidate set when overload
1117 /// resolution fails.
1118 OverloadCandidateSet &getFailedCandidateSet() {
1119 return FailedCandidateSet;
1122 /// \brief Get the overloading result, for when the initialization
1123 /// sequence failed due to a bad overload.
1124 OverloadingResult getFailedOverloadResult() const {
1125 return FailedOverloadResult;
1128 /// \brief Note that this initialization sequence failed due to an
1129 /// incomplete type.
1130 void setIncompleteTypeFailure(QualType IncompleteType) {
1131 FailedIncompleteType = IncompleteType;
1132 SetFailed(FK_Incomplete);
1135 /// \brief Determine why initialization failed.
1136 FailureKind getFailureKind() const {
1137 assert(Failed() && "Not an initialization failure!");
1141 /// \brief Dump a representation of this initialization sequence to
1142 /// the given stream, for debugging purposes.
1143 void dump(raw_ostream &OS) const;
1145 /// \brief Dump a representation of this initialization sequence to
1146 /// standard error, for debugging purposes.
1150 } // end namespace clang
1152 #endif // LLVM_CLANG_SEMA_INITIALIZATION_H