DeclCXX.h source code [clang/include/clang/AST/DeclCXX.h]

1	//===- DeclCXX.h - Classes for representing C++ declarations --- C++ --=====//
2	//
3	// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4	// See https://llvm.org/LICENSE.txt for license information.
5	// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
9	/// \file
10	/// Defines the C++ Decl subclasses, other than those for templates
11	/// (found in DeclTemplate.h) and friends (in DeclFriend.h).
12	//
13	//===----------------------------------------------------------------------===//
14
15	#ifndef LLVM_CLANG_AST_DECLCXX_H
16	#define LLVM_CLANG_AST_DECLCXX_H
17
18	#include "clang/AST/ASTUnresolvedSet.h"
19	#include "clang/AST/Decl.h"
20	#include "clang/AST/DeclBase.h"
21	#include "clang/AST/DeclarationName.h"
22	#include "clang/AST/Expr.h"
23	#include "clang/AST/ExternalASTSource.h"
24	#include "clang/AST/LambdaCapture.h"
25	#include "clang/AST/NestedNameSpecifier.h"
26	#include "clang/AST/Redeclarable.h"
27	#include "clang/AST/Stmt.h"
28	#include "clang/AST/Type.h"
29	#include "clang/AST/TypeLoc.h"
30	#include "clang/AST/UnresolvedSet.h"
31	#include "clang/Basic/LLVM.h"
32	#include "clang/Basic/Lambda.h"
33	#include "clang/Basic/LangOptions.h"
34	#include "clang/Basic/OperatorKinds.h"
35	#include "clang/Basic/SourceLocation.h"
36	#include "clang/Basic/Specifiers.h"
37	#include "llvm/ADT/ArrayRef.h"
38	#include "llvm/ADT/DenseMap.h"
39	#include "llvm/ADT/PointerIntPair.h"
40	#include "llvm/ADT/PointerUnion.h"
41	#include "llvm/ADT/STLExtras.h"
42	#include "llvm/ADT/TinyPtrVector.h"
43	#include "llvm/ADT/iterator_range.h"
44	#include "llvm/Support/Casting.h"
45	#include "llvm/Support/Compiler.h"
46	#include "llvm/Support/PointerLikeTypeTraits.h"
47	#include "llvm/Support/TrailingObjects.h"
48	#include <cassert>
49	#include <cstddef>
50	#include <iterator>
51	#include <memory>
52	#include <vector>
53
54	namespace clang {
55
56	class ASTContext;
57	class ClassTemplateDecl;
58	class ConstructorUsingShadowDecl;
59	class CXXBasePath;
60	class CXXBasePaths;
61	class CXXConstructorDecl;
62	class CXXDestructorDecl;
63	class CXXFinalOverriderMap;
64	class CXXIndirectPrimaryBaseSet;
65	class CXXMethodDecl;
66	class DecompositionDecl;
67	class FriendDecl;
68	class FunctionTemplateDecl;
69	class IdentifierInfo;
70	class MemberSpecializationInfo;
71	class BaseUsingDecl;
72	class TemplateDecl;
73	class TemplateParameterList;
74	class UsingDecl;
75
76	/// Represents an access specifier followed by colon ':'.
77	///
78	/// An objects of this class represents sugar for the syntactic occurrence
79	/// of an access specifier followed by a colon in the list of member
80	/// specifiers of a C++ class definition.
81	///
82	/// Note that they do not represent other uses of access specifiers,
83	/// such as those occurring in a list of base specifiers.
84	/// Also note that this class has nothing to do with so-called
85	/// "access declarations" (C++98 11.3 [class.access.dcl]).
86	class AccessSpecDecl : public Decl {
87	/// The location of the ':'.
88	SourceLocation ColonLoc;
89
90	AccessSpecDecl(AccessSpecifier AS, DeclContext *DC,
91	SourceLocation ASLoc, SourceLocation ColonLoc)
92	: Decl(AccessSpec, DC, ASLoc), ColonLoc (ColonLoc) {
93	setAccess(AS);
94	}
95
96	AccessSpecDecl(EmptyShell Empty) : Decl(AccessSpec, Empty) {}
97
98	virtual void anchor();
99
100	public:
101	/// The location of the access specifier.
102	SourceLocation getAccessSpecifierLoc() const { return getLocation(); }
103
104	/// Sets the location of the access specifier.
105	void setAccessSpecifierLoc(SourceLocation ASLoc) { setLocation(ASLoc); }
106
107	/// The location of the colon following the access specifier.
108	SourceLocation getColonLoc() const { return ColonLoc; }
109
110	/// Sets the location of the colon.
111	void setColonLoc(SourceLocation CLoc) { ColonLoc = CLoc; }
112
113	SourceRange getSourceRange() const override LLVM_READONLY {
114	return SourceRange (getAccessSpecifierLoc(), getColonLoc());
115	}
116
117	static AccessSpecDecl *Create(ASTContext &C, AccessSpecifier AS,
118	DeclContext *DC, SourceLocation ASLoc,
119	SourceLocation ColonLoc) {
120	return new (C, DC) AccessSpecDecl (AS, DC, ASLoc, ColonLoc);
121	}
122
123	static AccessSpecDecl *CreateDeserialized(ASTContext &C, DeclID ID);
124
125	// Implement isa/cast/dyncast/etc.
126	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
127	static bool classofKind(Kind K) { return K == AccessSpec; }
128	};
129
130	/// Represents a base class of a C++ class.
131	///
132	/// Each CXXBaseSpecifier represents a single, direct base class (or
133	/// struct) of a C++ class (or struct). It specifies the type of that
134	/// base class, whether it is a virtual or non-virtual base, and what
135	/// level of access (public, protected, private) is used for the
136	/// derivation. For example:
137	///
138	/// \code
139	/// class A { };
140	/// class B { };
141	/// class C : public virtual A, protected B { };
142	/// \endcode
143	///
144	/// In this code, C will have two CXXBaseSpecifiers, one for "public
145	/// virtual A" and the other for "protected B".
146	class CXXBaseSpecifier {
147	/// The source code range that covers the full base
148	/// specifier, including the "virtual" (if present) and access
149	/// specifier (if present).
150	SourceRange Range;
151
152	/// The source location of the ellipsis, if this is a pack
153	/// expansion.
154	SourceLocation EllipsisLoc;
155
156	/// Whether this is a virtual base class or not.
157	LLVM_PREFERRED_TYPE(bool)
158	unsigned Virtual : `1`;
159
160	/// Whether this is the base of a class (true) or of a struct (false).
161	///
162	/// This determines the mapping from the access specifier as written in the
163	/// source code to the access specifier used for semantic analysis.
164	LLVM_PREFERRED_TYPE(bool)
165	unsigned BaseOfClass : `1`;
166
167	/// Access specifier as written in the source code (may be AS_none).
168	///
169	/// The actual type of data stored here is an AccessSpecifier, but we use
170	/// "unsigned" here to work around Microsoft ABI.
171	LLVM_PREFERRED_TYPE(AccessSpecifier)
172	unsigned Access : `2`;
173
174	/// Whether the class contains a using declaration
175	/// to inherit the named class's constructors.
176	LLVM_PREFERRED_TYPE(bool)
177	unsigned InheritConstructors : `1`;
178
179	/// The type of the base class.
180	///
181	/// This will be a class or struct (or a typedef of such). The source code
182	/// range does not include the \c virtual or the access specifier.
183	TypeSourceInfo *BaseTypeInfo;
184
185	public:
186	CXXBaseSpecifier() = default;
187	CXXBaseSpecifier(SourceRange R, bool V, bool BC, AccessSpecifier A,
188	TypeSourceInfo *TInfo, SourceLocation EllipsisLoc)
189	: Range (R), EllipsisLoc (EllipsisLoc), Virtual(V), BaseOfClass(BC),
190	Access(A), InheritConstructors(false), BaseTypeInfo(TInfo) {}
191
192	/// Retrieves the source range that contains the entire base specifier.
193	SourceRange getSourceRange() const LLVM_READONLY { return Range; }
194	SourceLocation getBeginLoc() const LLVM_READONLY { return Range.getBegin(); }
195	SourceLocation getEndLoc() const LLVM_READONLY { return Range.getEnd(); }
196
197	/// Get the location at which the base class type was written.
198	SourceLocation getBaseTypeLoc() const LLVM_READONLY {
199	return BaseTypeInfo->getTypeLoc().getBeginLoc();
200	}
201
202	/// Determines whether the base class is a virtual base class (or not).
203	bool isVirtual() const { return Virtual; }
204
205	/// Determine whether this base class is a base of a class declared
206	/// with the 'class' keyword (vs. one declared with the 'struct' keyword).
207	bool isBaseOfClass() const { return BaseOfClass; }
208
209	/// Determine whether this base specifier is a pack expansion.
210	bool isPackExpansion() const { return EllipsisLoc.isValid(); }
211
212	/// Determine whether this base class's constructors get inherited.
213	bool getInheritConstructors() const { return InheritConstructors; }
214
215	/// Set that this base class's constructors should be inherited.
216	void setInheritConstructors(bool Inherit = true) {
217	InheritConstructors = Inherit;
218	}
219
220	/// For a pack expansion, determine the location of the ellipsis.
221	SourceLocation getEllipsisLoc() const {
222	return EllipsisLoc;
223	}
224
225	/// Returns the access specifier for this base specifier.
226	///
227	/// This is the actual base specifier as used for semantic analysis, so
228	/// the result can never be AS_none. To retrieve the access specifier as
229	/// written in the source code, use getAccessSpecifierAsWritten().
230	AccessSpecifier getAccessSpecifier() const {
231	if ((AccessSpecifier)Access == AS_none)
232	return BaseOfClass? AS_private : AS_public;
233	else
234	return (AccessSpecifier)Access;
235	}
236
237	/// Retrieves the access specifier as written in the source code
238	/// (which may mean that no access specifier was explicitly written).
239	///
240	/// Use getAccessSpecifier() to retrieve the access specifier for use in
241	/// semantic analysis.
242	AccessSpecifier getAccessSpecifierAsWritten() const {
243	return (AccessSpecifier)Access;
244	}
245
246	/// Retrieves the type of the base class.
247	///
248	/// This type will always be an unqualified class type.
249	QualType getType() const {
250	return BaseTypeInfo->getType().getUnqualifiedType();
251	}
252
253	/// Retrieves the type and source location of the base class.
254	TypeSourceInfo getTypeSourceInfo() const* { return BaseTypeInfo; }
255	};
256
257	/// Represents a C++ struct/union/class.
258	class CXXRecordDecl : public RecordDecl {
259	friend class ASTDeclReader;
260	friend class ASTDeclWriter;
261	friend class ASTNodeImporter;
262	friend class ASTReader;
263	friend class ASTRecordWriter;
264	friend class ASTWriter;
265	friend class DeclContext;
266	friend class LambdaExpr;
267	friend class ODRDiagsEmitter;
268
269	friend void FunctionDecl::setIsPureVirtual(bool);
270	friend void TagDecl::startDefinition();
271
272	/// Values used in DefinitionData fields to represent special members.
273	enum SpecialMemberFlags {
274	SMF_DefaultConstructor = `0x1`,
275	SMF_CopyConstructor = `0x2`,
276	SMF_MoveConstructor = `0x4`,
277	SMF_CopyAssignment = `0x8`,
278	SMF_MoveAssignment = `0x10`,
279	SMF_Destructor = `0x20`,
280	SMF_All = `0x3f`
281	};
282
283	public:
284	enum LambdaDependencyKind {
285	LDK_Unknown = `0`,
286	LDK_AlwaysDependent,
287	LDK_NeverDependent,
288	};
289
290	private:
291	struct DefinitionData {
292	#define FIELD(Name, Width, Merge) \
293	unsigned Name : Width;
294	#include "CXXRecordDeclDefinitionBits.def"
295
296	/// Whether this class describes a C++ lambda.
297	LLVM_PREFERRED_TYPE(bool)
298	unsigned IsLambda : `1`;
299
300	/// Whether we are currently parsing base specifiers.
301	LLVM_PREFERRED_TYPE(bool)
302	unsigned IsParsingBaseSpecifiers : `1`;
303
304	/// True when visible conversion functions are already computed
305	/// and are available.
306	LLVM_PREFERRED_TYPE(bool)
307	unsigned ComputedVisibleConversions : `1`;
308
309	LLVM_PREFERRED_TYPE(bool)
310	unsigned HasODRHash : `1`;
311
312	/// A hash of parts of the class to help in ODR checking.
313	unsigned ODRHash = `0`;
314
315	/// The number of base class specifiers in Bases.
316	unsigned NumBases = `0`;
317
318	/// The number of virtual base class specifiers in VBases.
319	unsigned NumVBases = `0`;
320
321	/// Base classes of this class.
322	///
323	/// FIXME: This is wasted space for a union.
324	LazyCXXBaseSpecifiersPtr Bases;
325
326	/// direct and indirect virtual base classes of this class.
327	LazyCXXBaseSpecifiersPtr VBases;
328
329	/// The conversion functions of this C++ class (but not its
330	/// inherited conversion functions).
331	///
332	/// Each of the entries in this overload set is a CXXConversionDecl.
333	LazyASTUnresolvedSet Conversions;
334
335	/// The conversion functions of this C++ class and all those
336	/// inherited conversion functions that are visible in this class.
337	///
338	/// Each of the entries in this overload set is a CXXConversionDecl or a
339	/// FunctionTemplateDecl.
340	LazyASTUnresolvedSet VisibleConversions;
341
342	/// The declaration which defines this record.
343	CXXRecordDecl *Definition;
344
345	/// The first friend declaration in this class, or null if there
346	/// aren't any.
347	///
348	/// This is actually currently stored in reverse order.
349	LazyDeclPtr FirstFriend;
350
351	DefinitionData(CXXRecordDecl *D);
352
353	/// Retrieve the set of direct base classes.
354	CXXBaseSpecifier getBases() const* {
355	if (!Bases.isOffset())
356	return Bases.get(Source: nullptr);
357	return getBasesSlowCase();
358	}
359
360	/// Retrieve the set of virtual base classes.
361	CXXBaseSpecifier getVBases() const* {
362	if (!VBases.isOffset())
363	return VBases.get(Source: nullptr);
364	return getVBasesSlowCase();
365	}
366
367	ArrayRef<CXXBaseSpecifier> bases() const {
368	return llvm::ArrayRef(getBases(), NumBases);
369	}
370
371	ArrayRef<CXXBaseSpecifier> vbases() const {
372	return llvm::ArrayRef(getVBases(), NumVBases);
373	}
374
375	private:
376	CXXBaseSpecifier getBasesSlowCase() const*;
377	CXXBaseSpecifier getVBasesSlowCase() const*;
378	};
379
380	struct DefinitionData *DefinitionData;
381
382	/// Describes a C++ closure type (generated by a lambda expression).
383	struct LambdaDefinitionData : public DefinitionData {
384	using Capture = LambdaCapture;
385
386	/// Whether this lambda is known to be dependent, even if its
387	/// context isn't dependent.
388	///
389	/// A lambda with a non-dependent context can be dependent if it occurs
390	/// within the default argument of a function template, because the
391	/// lambda will have been created with the enclosing context as its
392	/// declaration context, rather than function. This is an unfortunate
393	/// artifact of having to parse the default arguments before.
394	LLVM_PREFERRED_TYPE(LambdaDependencyKind)
395	unsigned DependencyKind : `2`;
396
397	/// Whether this lambda is a generic lambda.
398	LLVM_PREFERRED_TYPE(bool)
399	unsigned IsGenericLambda : `1`;
400
401	/// The Default Capture.
402	LLVM_PREFERRED_TYPE(LambdaCaptureDefault)
403	unsigned CaptureDefault : `2`;
404
405	/// The number of captures in this lambda is limited 2^NumCaptures.
406	unsigned NumCaptures : `15`;
407
408	/// The number of explicit captures in this lambda.
409	unsigned NumExplicitCaptures : `12`;
410
411	/// Has known `internal` linkage.
412	LLVM_PREFERRED_TYPE(bool)
413	unsigned HasKnownInternalLinkage : `1`;
414
415	/// The number used to indicate this lambda expression for name
416	/// mangling in the Itanium C++ ABI.
417	unsigned ManglingNumber : `31`;
418
419	/// The index of this lambda within its context declaration. This is not in
420	/// general the same as the mangling number.
421	unsigned IndexInContext;
422
423	/// The declaration that provides context for this lambda, if the
424	/// actual DeclContext does not suffice. This is used for lambdas that
425	/// occur within default arguments of function parameters within the class
426	/// or within a data member initializer.
427	LazyDeclPtr ContextDecl;
428
429	/// The lists of captures, both explicit and implicit, for this
430	/// lambda. One list is provided for each merged copy of the lambda.
431	/// The first list corresponds to the canonical definition.
432	/// The destructor is registered by AddCaptureList when necessary.
433	llvm::TinyPtrVector<Capture*> Captures;
434
435	/// The type of the call method.
436	TypeSourceInfo *MethodTyInfo;
437
438	LambdaDefinitionData(CXXRecordDecl D, TypeSourceInfo Info, unsigned DK,
439	bool IsGeneric, LambdaCaptureDefault CaptureDefault)
440	: DefinitionData (D), DependencyKind(DK), IsGenericLambda(IsGeneric),
441	CaptureDefault(CaptureDefault), NumCaptures(`0`),
442	NumExplicitCaptures(`0`), HasKnownInternalLinkage(`0`), ManglingNumber(`0`),
443	IndexInContext(`0`), MethodTyInfo(Info) {
444	IsLambda = true;
445
446	// C++1z [expr.prim.lambda]p4:
447	// This class type is not an aggregate type.
448	Aggregate = false;
449	PlainOldData = false;
450	}
451
452	// Add a list of captures.
453	void AddCaptureList(ASTContext &Ctx, Capture *CaptureList);
454	};
455
456	struct DefinitionData dataPtr() const* {
457	// Complete the redecl chain (if necessary).
458	getMostRecentDecl();
459	return DefinitionData;
460	}
461
462	struct DefinitionData &data() const {
463	auto *DD = dataPtr();
464	assert(DD && "queried property of class with no definition");
465	return *DD;
466	}
467
468	struct LambdaDefinitionData &getLambdaData() const {
469	// No update required: a merged definition cannot change any lambda
470	// properties.
471	auto *DD = DefinitionData;
472	assert(DD && DD->IsLambda && "queried lambda property of non-lambda class");
473	return static_cast<LambdaDefinitionData&>(*DD);
474	}
475
476	/// The template or declaration that this declaration
477	/// describes or was instantiated from, respectively.
478	///
479	/// For non-templates, this value will be null. For record
480	/// declarations that describe a class template, this will be a
481	/// pointer to a ClassTemplateDecl. For member
482	/// classes of class template specializations, this will be the
483	/// MemberSpecializationInfo referring to the member class that was
484	/// instantiated or specialized.
485	llvm::PointerUnion<ClassTemplateDecl , MemberSpecializationInfo >
486	TemplateOrInstantiation;
487
488	/// Called from setBases and addedMember to notify the class that a
489	/// direct or virtual base class or a member of class type has been added.
490	void addedClassSubobject(CXXRecordDecl *Base);
491
492	/// Notify the class that member has been added.
493	///
494	/// This routine helps maintain information about the class based on which
495	/// members have been added. It will be invoked by DeclContext::addDecl()
496	/// whenever a member is added to this record.
497	void addedMember(Decl *D);
498
499	void markedVirtualFunctionPure();
500
501	/// Get the head of our list of friend declarations, possibly
502	/// deserializing the friends from an external AST source.
503	FriendDecl getFirstFriend() const*;
504
505	/// Determine whether this class has an empty base class subobject of type X
506	/// or of one of the types that might be at offset 0 within X (per the C++
507	/// "standard layout" rules).
508	bool hasSubobjectAtOffsetZeroOfEmptyBaseType(ASTContext &Ctx,
509	const CXXRecordDecl *X);
510
511	protected:
512	CXXRecordDecl(Kind K, TagKind TK, const ASTContext &C, DeclContext *DC,
513	SourceLocation StartLoc, SourceLocation IdLoc,
514	IdentifierInfo Id, CXXRecordDecl PrevDecl);
515
516	public:
517	/// Iterator that traverses the base classes of a class.
518	using base_class_iterator = CXXBaseSpecifier *;
519
520	/// Iterator that traverses the base classes of a class.
521	using base_class_const_iterator = const CXXBaseSpecifier *;
522
523	CXXRecordDecl *getCanonicalDecl() override {
524	return cast<CXXRecordDecl>(RecordDecl::getCanonicalDecl());
525	}
526
527	const CXXRecordDecl getCanonicalDecl() const* {
528	return const_cast<CXXRecordDecl>(this*)->getCanonicalDecl();
529	}
530
531	CXXRecordDecl *getPreviousDecl() {
532	return cast_or_null<CXXRecordDecl>(
533	static_cast<RecordDecl >(this*)->getPreviousDecl());
534	}
535
536	const CXXRecordDecl getPreviousDecl() const* {
537	return const_cast<CXXRecordDecl>(this*)->getPreviousDecl();
538	}
539
540	CXXRecordDecl *getMostRecentDecl() {
541	return cast<CXXRecordDecl>(
542	static_cast<RecordDecl >(this*)->getMostRecentDecl());
543	}
544
545	const CXXRecordDecl getMostRecentDecl() const* {
546	return const_cast<CXXRecordDecl>(this*)->getMostRecentDecl();
547	}
548
549	CXXRecordDecl *getMostRecentNonInjectedDecl() {
550	CXXRecordDecl *Recent =
551	static_cast<CXXRecordDecl >(this*)->getMostRecentDecl();
552	while (Recent->isInjectedClassName()) {
553	// FIXME: Does injected class name need to be in the redeclarations chain?
554	assert(Recent->getPreviousDecl());
555	Recent = Recent->getPreviousDecl();
556	}
557	return Recent;
558	}
559
560	const CXXRecordDecl getMostRecentNonInjectedDecl() const* {
561	return const_cast<CXXRecordDecl>(this*)->getMostRecentNonInjectedDecl();
562	}
563
564	CXXRecordDecl getDefinition() const* {
565	// We only need an update if we don't already know which
566	// declaration is the definition.
567	auto *DD = DefinitionData ? DefinitionData : dataPtr();
568	return DD ? DD->Definition : nullptr;
569	}
570
571	bool hasDefinition() const { return DefinitionData \|\| dataPtr(); }
572
573	static CXXRecordDecl Create(const* ASTContext &C, TagKind TK, DeclContext *DC,
574	SourceLocation StartLoc, SourceLocation IdLoc,
575	IdentifierInfo *Id,
576	CXXRecordDecl PrevDecl = nullptr*,
577	bool DelayTypeCreation = false);
578	static CXXRecordDecl CreateLambda(const* ASTContext &C, DeclContext *DC,
579	TypeSourceInfo *Info, SourceLocation Loc,
580	unsigned DependencyKind, bool IsGeneric,
581	LambdaCaptureDefault CaptureDefault);
582	static CXXRecordDecl CreateDeserialized(const* ASTContext &C, DeclID ID);
583
584	bool isDynamicClass() const {
585	return data().Polymorphic \|\| data().NumVBases != `0`;
586	}
587
588	/// @returns true if class is dynamic or might be dynamic because the
589	/// definition is incomplete of dependent.
590	bool mayBeDynamicClass() const {
591	return !hasDefinition() \|\| isDynamicClass() \|\| hasAnyDependentBases();
592	}
593
594	/// @returns true if class is non dynamic or might be non dynamic because the
595	/// definition is incomplete of dependent.
596	bool mayBeNonDynamicClass() const {
597	return !hasDefinition() \|\| !isDynamicClass() \|\| hasAnyDependentBases();
598	}
599
600	void setIsParsingBaseSpecifiers() { data().IsParsingBaseSpecifiers = true; }
601
602	bool isParsingBaseSpecifiers() const {
603	return data().IsParsingBaseSpecifiers;
604	}
605
606	unsigned getODRHash() const;
607
608	/// Sets the base classes of this struct or class.
609	void setBases(CXXBaseSpecifier const * const Bases, unsigned* NumBases);
610
611	/// Retrieves the number of base classes of this class.
612	unsigned getNumBases() const { return data().NumBases; }
613
614	using base_class_range = llvm::iterator_range<base_class_iterator>;
615	using base_class_const_range =
616	llvm::iterator_range<base_class_const_iterator>;
617
618	base_class_range bases() {
619	return base_class_range (bases_begin(), bases_end());
620	}
621	base_class_const_range bases() const {
622	return base_class_const_range (bases_begin(), bases_end());
623	}
624
625	base_class_iterator bases_begin() { return data().getBases(); }
626	base_class_const_iterator bases_begin() const { return data().getBases(); }
627	base_class_iterator bases_end() { return bases_begin() + data().NumBases; }
628	base_class_const_iterator bases_end() const {
629	return bases_begin() + data().NumBases;
630	}
631
632	/// Retrieves the number of virtual base classes of this class.
633	unsigned getNumVBases() const { return data().NumVBases; }
634
635	base_class_range vbases() {
636	return base_class_range (vbases_begin(), vbases_end());
637	}
638	base_class_const_range vbases() const {
639	return base_class_const_range (vbases_begin(), vbases_end());
640	}
641
642	base_class_iterator vbases_begin() { return data().getVBases(); }
643	base_class_const_iterator vbases_begin() const { return data().getVBases(); }
644	base_class_iterator vbases_end() { return vbases_begin() + data().NumVBases; }
645	base_class_const_iterator vbases_end() const {
646	return vbases_begin() + data().NumVBases;
647	}
648
649	/// Determine whether this class has any dependent base classes which
650	/// are not the current instantiation.
651	bool hasAnyDependentBases() const;
652
653	/// Iterator access to method members. The method iterator visits
654	/// all method members of the class, including non-instance methods,
655	/// special methods, etc.
656	using method_iterator = specific_decl_iterator<CXXMethodDecl>;
657	using method_range =
658	llvm::iterator_range<specific_decl_iterator<CXXMethodDecl>>;
659
660	method_range methods() const {
661	return method_range (method_begin(), method_end());
662	}
663
664	/// Method begin iterator. Iterates in the order the methods
665	/// were declared.
666	method_iterator method_begin() const {
667	return method_iterator(decls_begin());
668	}
669
670	/// Method past-the-end iterator.
671	method_iterator method_end() const {
672	return method_iterator(decls_end());
673	}
674
675	/// Iterator access to constructor members.
676	using ctor_iterator = specific_decl_iterator<CXXConstructorDecl>;
677	using ctor_range =
678	llvm::iterator_range<specific_decl_iterator<CXXConstructorDecl>>;
679
680	ctor_range ctors() const { return ctor_range (ctor_begin(), ctor_end()); }
681
682	ctor_iterator ctor_begin() const {
683	return ctor_iterator(decls_begin());
684	}
685
686	ctor_iterator ctor_end() const {
687	return ctor_iterator(decls_end());
688	}
689
690	/// An iterator over friend declarations. All of these are defined
691	/// in DeclFriend.h.
692	class friend_iterator;
693	using friend_range = llvm::iterator_range<friend_iterator>;
694
695	friend_range friends() const;
696	friend_iterator friend_begin() const;
697	friend_iterator friend_end() const;
698	void pushFriendDecl(FriendDecl *FD);
699
700	/// Determines whether this record has any friends.
701	bool hasFriends() const {
702	return data().FirstFriend.isValid();
703	}
704
705	/// \c true if a defaulted copy constructor for this class would be
706	/// deleted.
707	bool defaultedCopyConstructorIsDeleted() const {
708	assert((!needsOverloadResolutionForCopyConstructor() \|\|
709	(data().DeclaredSpecialMembers & SMF_CopyConstructor)) &&
710	"this property has not yet been computed by Sema");
711	return data().DefaultedCopyConstructorIsDeleted;
712	}
713
714	/// \c true if a defaulted move constructor for this class would be
715	/// deleted.
716	bool defaultedMoveConstructorIsDeleted() const {
717	assert((!needsOverloadResolutionForMoveConstructor() \|\|
718	(data().DeclaredSpecialMembers & SMF_MoveConstructor)) &&
719	"this property has not yet been computed by Sema");
720	return data().DefaultedMoveConstructorIsDeleted;
721	}
722
723	/// \c true if a defaulted destructor for this class would be deleted.
724	bool defaultedDestructorIsDeleted() const {
725	assert((!needsOverloadResolutionForDestructor() \|\|
726	(data().DeclaredSpecialMembers & SMF_Destructor)) &&
727	"this property has not yet been computed by Sema");
728	return data().DefaultedDestructorIsDeleted;
729	}
730
731	/// \c true if we know for sure that this class has a single,
732	/// accessible, unambiguous copy constructor that is not deleted.
733	bool hasSimpleCopyConstructor() const {
734	return !hasUserDeclaredCopyConstructor() &&
735	!data().DefaultedCopyConstructorIsDeleted;
736	}
737
738	/// \c true if we know for sure that this class has a single,
739	/// accessible, unambiguous move constructor that is not deleted.
740	bool hasSimpleMoveConstructor() const {
741	return !hasUserDeclaredMoveConstructor() && hasMoveConstructor() &&
742	!data().DefaultedMoveConstructorIsDeleted;
743	}
744
745	/// \c true if we know for sure that this class has a single,
746	/// accessible, unambiguous copy assignment operator that is not deleted.
747	bool hasSimpleCopyAssignment() const {
748	return !hasUserDeclaredCopyAssignment() &&
749	!data().DefaultedCopyAssignmentIsDeleted;
750	}
751
752	/// \c true if we know for sure that this class has a single,
753	/// accessible, unambiguous move assignment operator that is not deleted.
754	bool hasSimpleMoveAssignment() const {
755	return !hasUserDeclaredMoveAssignment() && hasMoveAssignment() &&
756	!data().DefaultedMoveAssignmentIsDeleted;
757	}
758
759	/// \c true if we know for sure that this class has an accessible
760	/// destructor that is not deleted.
761	bool hasSimpleDestructor() const {
762	return !hasUserDeclaredDestructor() &&
763	!data().DefaultedDestructorIsDeleted;
764	}
765
766	/// Determine whether this class has any default constructors.
767	bool hasDefaultConstructor() const {
768	return (data().DeclaredSpecialMembers & SMF_DefaultConstructor) \|\|
769	needsImplicitDefaultConstructor();
770	}
771
772	/// Determine if we need to declare a default constructor for
773	/// this class.
774	///
775	/// This value is used for lazy creation of default constructors.
776	bool needsImplicitDefaultConstructor() const {
777	return (!data().UserDeclaredConstructor &&
778	!(data().DeclaredSpecialMembers & SMF_DefaultConstructor) &&
779	(!isLambda() \|\| lambdaIsDefaultConstructibleAndAssignable())) \|\|
780	// FIXME: Proposed fix to core wording issue: if a class inherits
781	// a default constructor and doesn't explicitly declare one, one
782	// is declared implicitly.
783	(data().HasInheritedDefaultConstructor &&
784	!(data().DeclaredSpecialMembers & SMF_DefaultConstructor));
785	}
786
787	/// Determine whether this class has any user-declared constructors.
788	///
789	/// When true, a default constructor will not be implicitly declared.
790	bool hasUserDeclaredConstructor() const {
791	return data().UserDeclaredConstructor;
792	}
793
794	/// Whether this class has a user-provided default constructor
795	/// per C++11.
796	bool hasUserProvidedDefaultConstructor() const {
797	return data().UserProvidedDefaultConstructor;
798	}
799
800	/// Determine whether this class has a user-declared copy constructor.
801	///
802	/// When false, a copy constructor will be implicitly declared.
803	bool hasUserDeclaredCopyConstructor() const {
804	return data().UserDeclaredSpecialMembers & SMF_CopyConstructor;
805	}
806
807	/// Determine whether this class needs an implicit copy
808	/// constructor to be lazily declared.
809	bool needsImplicitCopyConstructor() const {
810	return !(data().DeclaredSpecialMembers & SMF_CopyConstructor);
811	}
812
813	/// Determine whether we need to eagerly declare a defaulted copy
814	/// constructor for this class.
815	bool needsOverloadResolutionForCopyConstructor() const {
816	// C++17 [class.copy.ctor]p6:
817	// If the class definition declares a move constructor or move assignment
818	// operator, the implicitly declared copy constructor is defined as
819	// deleted.
820	// In MSVC mode, sometimes a declared move assignment does not delete an
821	// implicit copy constructor, so defer this choice to Sema.
822	if (data().UserDeclaredSpecialMembers &
823	(SMF_MoveConstructor \| SMF_MoveAssignment))
824	return true;
825	return data().NeedOverloadResolutionForCopyConstructor;
826	}
827
828	/// Determine whether an implicit copy constructor for this type
829	/// would have a parameter with a const-qualified reference type.
830	bool implicitCopyConstructorHasConstParam() const {
831	return data().ImplicitCopyConstructorCanHaveConstParamForNonVBase &&
832	(isAbstract() \|\|
833	data().ImplicitCopyConstructorCanHaveConstParamForVBase);
834	}
835
836	/// Determine whether this class has a copy constructor with
837	/// a parameter type which is a reference to a const-qualified type.
838	bool hasCopyConstructorWithConstParam() const {
839	return data().HasDeclaredCopyConstructorWithConstParam \|\|
840	(needsImplicitCopyConstructor() &&
841	implicitCopyConstructorHasConstParam());
842	}
843
844	/// Whether this class has a user-declared move constructor or
845	/// assignment operator.
846	///
847	/// When false, a move constructor and assignment operator may be
848	/// implicitly declared.
849	bool hasUserDeclaredMoveOperation() const {
850	return data().UserDeclaredSpecialMembers &
851	(SMF_MoveConstructor \| SMF_MoveAssignment);
852	}
853
854	/// Determine whether this class has had a move constructor
855	/// declared by the user.
856	bool hasUserDeclaredMoveConstructor() const {
857	return data().UserDeclaredSpecialMembers & SMF_MoveConstructor;
858	}
859
860	/// Determine whether this class has a move constructor.
861	bool hasMoveConstructor() const {
862	return (data().DeclaredSpecialMembers & SMF_MoveConstructor) \|\|
863	needsImplicitMoveConstructor();
864	}
865
866	/// Set that we attempted to declare an implicit copy
867	/// constructor, but overload resolution failed so we deleted it.
868	void setImplicitCopyConstructorIsDeleted() {
869	assert((data().DefaultedCopyConstructorIsDeleted \|\|
870	needsOverloadResolutionForCopyConstructor()) &&
871	"Copy constructor should not be deleted");
872	data().DefaultedCopyConstructorIsDeleted = true;
873	}
874
875	/// Set that we attempted to declare an implicit move
876	/// constructor, but overload resolution failed so we deleted it.
877	void setImplicitMoveConstructorIsDeleted() {
878	assert((data().DefaultedMoveConstructorIsDeleted \|\|
879	needsOverloadResolutionForMoveConstructor()) &&
880	"move constructor should not be deleted");
881	data().DefaultedMoveConstructorIsDeleted = true;
882	}
883
884	/// Set that we attempted to declare an implicit destructor,
885	/// but overload resolution failed so we deleted it.
886	void setImplicitDestructorIsDeleted() {
887	assert((data().DefaultedDestructorIsDeleted \|\|
888	needsOverloadResolutionForDestructor()) &&
889	"destructor should not be deleted");
890	data().DefaultedDestructorIsDeleted = true;
891	}
892
893	/// Determine whether this class should get an implicit move
894	/// constructor or if any existing special member function inhibits this.
895	bool needsImplicitMoveConstructor() const {
896	return !(data().DeclaredSpecialMembers & SMF_MoveConstructor) &&
897	!hasUserDeclaredCopyConstructor() &&
898	!hasUserDeclaredCopyAssignment() &&
899	!hasUserDeclaredMoveAssignment() &&
900	!hasUserDeclaredDestructor();
901	}
902
903	/// Determine whether we need to eagerly declare a defaulted move
904	/// constructor for this class.
905	bool needsOverloadResolutionForMoveConstructor() const {
906	return data().NeedOverloadResolutionForMoveConstructor;
907	}
908
909	/// Determine whether this class has a user-declared copy assignment
910	/// operator.
911	///
912	/// When false, a copy assignment operator will be implicitly declared.
913	bool hasUserDeclaredCopyAssignment() const {
914	return data().UserDeclaredSpecialMembers & SMF_CopyAssignment;
915	}
916
917	/// Set that we attempted to declare an implicit copy assignment
918	/// operator, but overload resolution failed so we deleted it.
919	void setImplicitCopyAssignmentIsDeleted() {
920	assert((data().DefaultedCopyAssignmentIsDeleted \|\|
921	needsOverloadResolutionForCopyAssignment()) &&
922	"copy assignment should not be deleted");
923	data().DefaultedCopyAssignmentIsDeleted = true;
924	}
925
926	/// Determine whether this class needs an implicit copy
927	/// assignment operator to be lazily declared.
928	bool needsImplicitCopyAssignment() const {
929	return !(data().DeclaredSpecialMembers & SMF_CopyAssignment);
930	}
931
932	/// Determine whether we need to eagerly declare a defaulted copy
933	/// assignment operator for this class.
934	bool needsOverloadResolutionForCopyAssignment() const {
935	// C++20 [class.copy.assign]p2:
936	// If the class definition declares a move constructor or move assignment
937	// operator, the implicitly declared copy assignment operator is defined
938	// as deleted.
939	// In MSVC mode, sometimes a declared move constructor does not delete an
940	// implicit copy assignment, so defer this choice to Sema.
941	if (data().UserDeclaredSpecialMembers &
942	(SMF_MoveConstructor \| SMF_MoveAssignment))
943	return true;
944	return data().NeedOverloadResolutionForCopyAssignment;
945	}
946
947	/// Determine whether an implicit copy assignment operator for this
948	/// type would have a parameter with a const-qualified reference type.
949	bool implicitCopyAssignmentHasConstParam() const {
950	return data().ImplicitCopyAssignmentHasConstParam;
951	}
952
953	/// Determine whether this class has a copy assignment operator with
954	/// a parameter type which is a reference to a const-qualified type or is not
955	/// a reference.
956	bool hasCopyAssignmentWithConstParam() const {
957	return data().HasDeclaredCopyAssignmentWithConstParam \|\|
958	(needsImplicitCopyAssignment() &&
959	implicitCopyAssignmentHasConstParam());
960	}
961
962	/// Determine whether this class has had a move assignment
963	/// declared by the user.
964	bool hasUserDeclaredMoveAssignment() const {
965	return data().UserDeclaredSpecialMembers & SMF_MoveAssignment;
966	}
967
968	/// Determine whether this class has a move assignment operator.
969	bool hasMoveAssignment() const {
970	return (data().DeclaredSpecialMembers & SMF_MoveAssignment) \|\|
971	needsImplicitMoveAssignment();
972	}
973
974	/// Set that we attempted to declare an implicit move assignment
975	/// operator, but overload resolution failed so we deleted it.
976	void setImplicitMoveAssignmentIsDeleted() {
977	assert((data().DefaultedMoveAssignmentIsDeleted \|\|
978	needsOverloadResolutionForMoveAssignment()) &&
979	"move assignment should not be deleted");
980	data().DefaultedMoveAssignmentIsDeleted = true;
981	}
982
983	/// Determine whether this class should get an implicit move
984	/// assignment operator or if any existing special member function inhibits
985	/// this.
986	bool needsImplicitMoveAssignment() const {
987	return !(data().DeclaredSpecialMembers & SMF_MoveAssignment) &&
988	!hasUserDeclaredCopyConstructor() &&
989	!hasUserDeclaredCopyAssignment() &&
990	!hasUserDeclaredMoveConstructor() &&
991	!hasUserDeclaredDestructor() &&
992	(!isLambda() \|\| lambdaIsDefaultConstructibleAndAssignable());
993	}
994
995	/// Determine whether we need to eagerly declare a move assignment
996	/// operator for this class.
997	bool needsOverloadResolutionForMoveAssignment() const {
998	return data().NeedOverloadResolutionForMoveAssignment;
999	}
1000
1001	/// Determine whether this class has a user-declared destructor.
1002	///
1003	/// When false, a destructor will be implicitly declared.
1004	bool hasUserDeclaredDestructor() const {
1005	return data().UserDeclaredSpecialMembers & SMF_Destructor;
1006	}
1007
1008	/// Determine whether this class needs an implicit destructor to
1009	/// be lazily declared.
1010	bool needsImplicitDestructor() const {
1011	return !(data().DeclaredSpecialMembers & SMF_Destructor);
1012	}
1013
1014	/// Determine whether we need to eagerly declare a destructor for this
1015	/// class.
1016	bool needsOverloadResolutionForDestructor() const {
1017	return data().NeedOverloadResolutionForDestructor;
1018	}
1019
1020	/// Determine whether this class describes a lambda function object.
1021	bool isLambda() const {
1022	// An update record can't turn a non-lambda into a lambda.
1023	auto *DD = DefinitionData;
1024	return DD && DD->IsLambda;
1025	}
1026
1027	/// Determine whether this class describes a generic
1028	/// lambda function object (i.e. function call operator is
1029	/// a template).
1030	bool isGenericLambda() const;
1031
1032	/// Determine whether this lambda should have an implicit default constructor
1033	/// and copy and move assignment operators.
1034	bool lambdaIsDefaultConstructibleAndAssignable() const;
1035
1036	/// Retrieve the lambda call operator of the closure type
1037	/// if this is a closure type.
1038	CXXMethodDecl getLambdaCallOperator() const*;
1039
1040	/// Retrieve the dependent lambda call operator of the closure type
1041	/// if this is a templated closure type.
1042	FunctionTemplateDecl getDependentLambdaCallOperator() const*;
1043
1044	/// Retrieve the lambda static invoker, the address of which
1045	/// is returned by the conversion operator, and the body of which
1046	/// is forwarded to the lambda call operator. The version that does not
1047	/// take a calling convention uses the 'default' calling convention for free
1048	/// functions if the Lambda's calling convention was not modified via
1049	/// attribute. Otherwise, it will return the calling convention specified for
1050	/// the lambda.
1051	CXXMethodDecl getLambdaStaticInvoker() const*;
1052	CXXMethodDecl getLambdaStaticInvoker(CallingConv CC) const*;
1053
1054	/// Retrieve the generic lambda's template parameter list.
1055	/// Returns null if the class does not represent a lambda or a generic
1056	/// lambda.
1057	TemplateParameterList getGenericLambdaTemplateParameterList() const*;
1058
1059	/// Retrieve the lambda template parameters that were specified explicitly.
1060	ArrayRef<NamedDecl > getLambdaExplicitTemplateParameters() const*;
1061
1062	LambdaCaptureDefault getLambdaCaptureDefault() const {
1063	assert(isLambda());
1064	return static_cast<LambdaCaptureDefault>(getLambdaData().CaptureDefault);
1065	}
1066
1067	bool isCapturelessLambda() const {
1068	if (!isLambda())
1069	return false;
1070	return getLambdaCaptureDefault() == LCD_None && capture_size() == `0`;
1071	}
1072
1073	/// Set the captures for this lambda closure type.
1074	void setCaptures(ASTContext &Context, ArrayRef<LambdaCapture> Captures);
1075
1076	/// For a closure type, retrieve the mapping from captured
1077	/// variables and \c this to the non-static data members that store the
1078	/// values or references of the captures.
1079	///
1080	/// \param Captures Will be populated with the mapping from captured
1081	/// variables to the corresponding fields.
1082	///
1083	/// \param ThisCapture Will be set to the field declaration for the
1084	/// \c this capture.
1085	///
1086	/// \note No entries will be added for init-captures, as they do not capture
1087	/// variables.
1088	///
1089	/// \note If multiple versions of the lambda are merged together, they may
1090	/// have different variable declarations corresponding to the same capture.
1091	/// In that case, all of those variable declarations will be added to the
1092	/// Captures list, so it may have more than one variable listed per field.
1093	void
1094	getCaptureFields(llvm::DenseMap<const ValueDecl , FieldDecl > &Captures,
1095	FieldDecl &ThisCapture) const*;
1096
1097	using capture_const_iterator = const LambdaCapture *;
1098	using capture_const_range = llvm::iterator_range<capture_const_iterator>;
1099
1100	capture_const_range captures() const {
1101	return capture_const_range (captures_begin(), captures_end());
1102	}
1103
1104	capture_const_iterator captures_begin() const {
1105	if (!isLambda()) return nullptr;
1106	LambdaDefinitionData &LambdaData = getLambdaData();
1107	return LambdaData.Captures.empty() ? nullptr : LambdaData.Captures.front();
1108	}
1109
1110	capture_const_iterator captures_end() const {
1111	return isLambda() ? captures_begin() + getLambdaData().NumCaptures
1112	: nullptr;
1113	}
1114
1115	unsigned capture_size() const { return getLambdaData().NumCaptures; }
1116
1117	const LambdaCapture getCapture(unsigned* I) const {
1118	assert(isLambda() && I < capture_size() && "invalid index for capture");
1119	return captures_begin() + I;
1120	}
1121
1122	using conversion_iterator = UnresolvedSetIterator;
1123
1124	conversion_iterator conversion_begin() const {
1125	return data().Conversions.get(C&: getASTContext()).begin();
1126	}
1127
1128	conversion_iterator conversion_end() const {
1129	return data().Conversions.get(C&: getASTContext()).end();
1130	}
1131
1132	/// Removes a conversion function from this class. The conversion
1133	/// function must currently be a member of this class. Furthermore,
1134	/// this class must currently be in the process of being defined.
1135	void removeConversion(const NamedDecl *Old);
1136
1137	/// Get all conversion functions visible in current class,
1138	/// including conversion function templates.
1139	llvm::iterator_range<conversion_iterator>
1140	getVisibleConversionFunctions() const;
1141
1142	/// Determine whether this class is an aggregate (C++ [dcl.init.aggr]),
1143	/// which is a class with no user-declared constructors, no private
1144	/// or protected non-static data members, no base classes, and no virtual
1145	/// functions (C++ [dcl.init.aggr]p1).
1146	bool isAggregate() const { return data().Aggregate; }
1147
1148	/// Whether this class has any in-class initializers
1149	/// for non-static data members (including those in anonymous unions or
1150	/// structs).
1151	bool hasInClassInitializer() const { return data().HasInClassInitializer; }
1152
1153	/// Whether this class or any of its subobjects has any members of
1154	/// reference type which would make value-initialization ill-formed.
1155	///
1156	/// Per C++03 [dcl.init]p5:
1157	/// - if T is a non-union class type without a user-declared constructor,
1158	/// then every non-static data member and base-class component of T is
1159	/// value-initialized [...] A program that calls for [...]
1160	/// value-initialization of an entity of reference type is ill-formed.
1161	bool hasUninitializedReferenceMember() const {
1162	return !isUnion() && !hasUserDeclaredConstructor() &&
1163	data().HasUninitializedReferenceMember;
1164	}
1165
1166	/// Whether this class is a POD-type (C++ [class]p4)
1167	///
1168	/// For purposes of this function a class is POD if it is an aggregate
1169	/// that has no non-static non-POD data members, no reference data
1170	/// members, no user-defined copy assignment operator and no
1171	/// user-defined destructor.
1172	///
1173	/// Note that this is the C++ TR1 definition of POD.
1174	bool isPOD() const { return data().PlainOldData; }
1175
1176	/// True if this class is C-like, without C++-specific features, e.g.
1177	/// it contains only public fields, no bases, tag kind is not 'class', etc.
1178	bool isCLike() const;
1179
1180	/// Determine whether this is an empty class in the sense of
1181	/// (C++11 [meta.unary.prop]).
1182	///
1183	/// The CXXRecordDecl is a class type, but not a union type,
1184	/// with no non-static data members other than bit-fields of length 0,
1185	/// no virtual member functions, no virtual base classes,
1186	/// and no base class B for which is_empty<B>::value is false.
1187	///
1188	/// \note This does NOT include a check for union-ness.
1189	bool isEmpty() const { return data().Empty; }
1190	/// Marks this record as empty. This is used by DWARFASTParserClang
1191	/// when parsing records with empty fields having [[no_unique_address]]
1192	/// attribute
1193	void markEmpty() { data().Empty = true; }
1194
1195	void setInitMethod(bool Val) { data().HasInitMethod = Val; }
1196	bool hasInitMethod() const { return data().HasInitMethod; }
1197
1198	bool hasPrivateFields() const {
1199	return data().HasPrivateFields;
1200	}
1201
1202	bool hasProtectedFields() const {
1203	return data().HasProtectedFields;
1204	}
1205
1206	/// Determine whether this class has direct non-static data members.
1207	bool hasDirectFields() const {
1208	auto &D = data();
1209	return D.HasPublicFields \|\| D.HasProtectedFields \|\| D.HasPrivateFields;
1210	}
1211
1212	/// Whether this class is polymorphic (C++ [class.virtual]),
1213	/// which means that the class contains or inherits a virtual function.
1214	bool isPolymorphic() const { return data().Polymorphic; }
1215
1216	/// Determine whether this class has a pure virtual function.
1217	///
1218	/// The class is abstract per (C++ [class.abstract]p2) if it declares
1219	/// a pure virtual function or inherits a pure virtual function that is
1220	/// not overridden.
1221	bool isAbstract() const { return data().Abstract; }
1222
1223	/// Determine whether this class is standard-layout per
1224	/// C++ [class]p7.
1225	bool isStandardLayout() const { return data().IsStandardLayout; }
1226
1227	/// Determine whether this class was standard-layout per
1228	/// C++11 [class]p7, specifically using the C++11 rules without any DRs.
1229	bool isCXX11StandardLayout() const { return data().IsCXX11StandardLayout; }
1230
1231	/// Determine whether this class, or any of its class subobjects,
1232	/// contains a mutable field.
1233	bool hasMutableFields() const { return data().HasMutableFields; }
1234
1235	/// Determine whether this class has any variant members.
1236	bool hasVariantMembers() const { return data().HasVariantMembers; }
1237
1238	/// Determine whether this class has a trivial default constructor
1239	/// (C++11 [class.ctor]p5).
1240	bool hasTrivialDefaultConstructor() const {
1241	return hasDefaultConstructor() &&
1242	(data().HasTrivialSpecialMembers & SMF_DefaultConstructor);
1243	}
1244
1245	/// Determine whether this class has a non-trivial default constructor
1246	/// (C++11 [class.ctor]p5).
1247	bool hasNonTrivialDefaultConstructor() const {
1248	return (data().DeclaredNonTrivialSpecialMembers & SMF_DefaultConstructor) \|\|
1249	(needsImplicitDefaultConstructor() &&
1250	!(data().HasTrivialSpecialMembers & SMF_DefaultConstructor));
1251	}
1252
1253	/// Determine whether this class has at least one constexpr constructor
1254	/// other than the copy or move constructors.
1255	bool hasConstexprNonCopyMoveConstructor() const {
1256	return data().HasConstexprNonCopyMoveConstructor \|\|
1257	(needsImplicitDefaultConstructor() &&
1258	defaultedDefaultConstructorIsConstexpr());
1259	}
1260
1261	/// Determine whether a defaulted default constructor for this class
1262	/// would be constexpr.
1263	bool defaultedDefaultConstructorIsConstexpr() const {
1264	return data().DefaultedDefaultConstructorIsConstexpr &&
1265	(!isUnion() \|\| hasInClassInitializer() \|\| !hasVariantMembers() \|\|
1266	getLangOpts().CPlusPlus20);
1267	}
1268
1269	/// Determine whether this class has a constexpr default constructor.
1270	bool hasConstexprDefaultConstructor() const {
1271	return data().HasConstexprDefaultConstructor \|\|
1272	(needsImplicitDefaultConstructor() &&
1273	defaultedDefaultConstructorIsConstexpr());
1274	}
1275
1276	/// Determine whether this class has a trivial copy constructor
1277	/// (C++ [class.copy]p6, C++11 [class.copy]p12)
1278	bool hasTrivialCopyConstructor() const {
1279	return data().HasTrivialSpecialMembers & SMF_CopyConstructor;
1280	}
1281
1282	bool hasTrivialCopyConstructorForCall() const {
1283	return data().HasTrivialSpecialMembersForCall & SMF_CopyConstructor;
1284	}
1285
1286	/// Determine whether this class has a non-trivial copy constructor
1287	/// (C++ [class.copy]p6, C++11 [class.copy]p12)
1288	bool hasNonTrivialCopyConstructor() const {
1289	return data().DeclaredNonTrivialSpecialMembers & SMF_CopyConstructor \|\|
1290	!hasTrivialCopyConstructor();
1291	}
1292
1293	bool hasNonTrivialCopyConstructorForCall() const {
1294	return (data().DeclaredNonTrivialSpecialMembersForCall &
1295	SMF_CopyConstructor) \|\|
1296	!hasTrivialCopyConstructorForCall();
1297	}
1298
1299	/// Determine whether this class has a trivial move constructor
1300	/// (C++11 [class.copy]p12)
1301	bool hasTrivialMoveConstructor() const {
1302	return hasMoveConstructor() &&
1303	(data().HasTrivialSpecialMembers & SMF_MoveConstructor);
1304	}
1305
1306	bool hasTrivialMoveConstructorForCall() const {
1307	return hasMoveConstructor() &&
1308	(data().HasTrivialSpecialMembersForCall & SMF_MoveConstructor);
1309	}
1310
1311	/// Determine whether this class has a non-trivial move constructor
1312	/// (C++11 [class.copy]p12)
1313	bool hasNonTrivialMoveConstructor() const {
1314	return (data().DeclaredNonTrivialSpecialMembers & SMF_MoveConstructor) \|\|
1315	(needsImplicitMoveConstructor() &&
1316	!(data().HasTrivialSpecialMembers & SMF_MoveConstructor));
1317	}
1318
1319	bool hasNonTrivialMoveConstructorForCall() const {
1320	return (data().DeclaredNonTrivialSpecialMembersForCall &
1321	SMF_MoveConstructor) \|\|
1322	(needsImplicitMoveConstructor() &&
1323	!(data().HasTrivialSpecialMembersForCall & SMF_MoveConstructor));
1324	}
1325
1326	/// Determine whether this class has a trivial copy assignment operator
1327	/// (C++ [class.copy]p11, C++11 [class.copy]p25)
1328	bool hasTrivialCopyAssignment() const {
1329	return data().HasTrivialSpecialMembers & SMF_CopyAssignment;
1330	}
1331
1332	/// Determine whether this class has a non-trivial copy assignment
1333	/// operator (C++ [class.copy]p11, C++11 [class.copy]p25)
1334	bool hasNonTrivialCopyAssignment() const {
1335	return data().DeclaredNonTrivialSpecialMembers & SMF_CopyAssignment \|\|
1336	!hasTrivialCopyAssignment();
1337	}
1338
1339	/// Determine whether this class has a trivial move assignment operator
1340	/// (C++11 [class.copy]p25)
1341	bool hasTrivialMoveAssignment() const {
1342	return hasMoveAssignment() &&
1343	(data().HasTrivialSpecialMembers & SMF_MoveAssignment);
1344	}
1345
1346	/// Determine whether this class has a non-trivial move assignment
1347	/// operator (C++11 [class.copy]p25)
1348	bool hasNonTrivialMoveAssignment() const {
1349	return (data().DeclaredNonTrivialSpecialMembers & SMF_MoveAssignment) \|\|
1350	(needsImplicitMoveAssignment() &&
1351	!(data().HasTrivialSpecialMembers & SMF_MoveAssignment));
1352	}
1353
1354	/// Determine whether a defaulted default constructor for this class
1355	/// would be constexpr.
1356	bool defaultedDestructorIsConstexpr() const {
1357	return data().DefaultedDestructorIsConstexpr &&
1358	getLangOpts().CPlusPlus20;
1359	}
1360
1361	/// Determine whether this class has a constexpr destructor.
1362	bool hasConstexprDestructor() const;
1363
1364	/// Determine whether this class has a trivial destructor
1365	/// (C++ [class.dtor]p3)
1366	bool hasTrivialDestructor() const {
1367	return data().HasTrivialSpecialMembers & SMF_Destructor;
1368	}
1369
1370	bool hasTrivialDestructorForCall() const {
1371	return data().HasTrivialSpecialMembersForCall & SMF_Destructor;
1372	}
1373
1374	/// Determine whether this class has a non-trivial destructor
1375	/// (C++ [class.dtor]p3)
1376	bool hasNonTrivialDestructor() const {
1377	return !(data().HasTrivialSpecialMembers & SMF_Destructor);
1378	}
1379
1380	bool hasNonTrivialDestructorForCall() const {
1381	return !(data().HasTrivialSpecialMembersForCall & SMF_Destructor);
1382	}
1383
1384	void setHasTrivialSpecialMemberForCall() {
1385	data().HasTrivialSpecialMembersForCall =
1386	(SMF_CopyConstructor \| SMF_MoveConstructor \| SMF_Destructor);
1387	}
1388
1389	/// Determine whether declaring a const variable with this type is ok
1390	/// per core issue 253.
1391	bool allowConstDefaultInit() const {
1392	return !data().HasUninitializedFields \|\|
1393	!(data().HasDefaultedDefaultConstructor \|\|
1394	needsImplicitDefaultConstructor());
1395	}
1396
1397	/// Determine whether this class has a destructor which has no
1398	/// semantic effect.
1399	///
1400	/// Any such destructor will be trivial, public, defaulted and not deleted,
1401	/// and will call only irrelevant destructors.
1402	bool hasIrrelevantDestructor() const {
1403	return data().HasIrrelevantDestructor;
1404	}
1405
1406	/// Determine whether this class has a non-literal or/ volatile type
1407	/// non-static data member or base class.
1408	bool hasNonLiteralTypeFieldsOrBases() const {
1409	return data().HasNonLiteralTypeFieldsOrBases;
1410	}
1411
1412	/// Determine whether this class has a using-declaration that names
1413	/// a user-declared base class constructor.
1414	bool hasInheritedConstructor() const {
1415	return data().HasInheritedConstructor;
1416	}
1417
1418	/// Determine whether this class has a using-declaration that names
1419	/// a base class assignment operator.
1420	bool hasInheritedAssignment() const {
1421	return data().HasInheritedAssignment;
1422	}
1423
1424	/// Determine whether this class is considered trivially copyable per
1425	/// (C++11 [class]p6).
1426	bool isTriviallyCopyable() const;
1427
1428	/// Determine whether this class is considered trivially copyable per
1429	bool isTriviallyCopyConstructible() const;
1430
1431	/// Determine whether this class is considered trivial.
1432	///
1433	/// C++11 [class]p6:
1434	/// "A trivial class is a class that has a trivial default constructor and
1435	/// is trivially copyable."
1436	bool isTrivial() const {
1437	return isTriviallyCopyable() && hasTrivialDefaultConstructor();
1438	}
1439
1440	/// Determine whether this class is a literal type.
1441	///
1442	/// C++20 [basic.types]p10:
1443	/// A class type that has all the following properties:
1444	/// - it has a constexpr destructor
1445	/// - all of its non-static non-variant data members and base classes
1446	/// are of non-volatile literal types, and it:
1447	/// - is a closure type
1448	/// - is an aggregate union type that has either no variant members
1449	/// or at least one variant member of non-volatile literal type
1450	/// - is a non-union aggregate type for which each of its anonymous
1451	/// union members satisfies the above requirements for an aggregate
1452	/// union type, or
1453	/// - has at least one constexpr constructor or constructor template
1454	/// that is not a copy or move constructor.
1455	bool isLiteral() const;
1456
1457	/// Determine whether this is a structural type.
1458	bool isStructural() const {
1459	return isLiteral() && data().StructuralIfLiteral;
1460	}
1461
1462	/// Notify the class that this destructor is now selected.
1463	///
1464	/// Important properties of the class depend on destructor properties. Since
1465	/// C++20, it is possible to have multiple destructor declarations in a class
1466	/// out of which one will be selected at the end.
1467	/// This is called separately from addedMember because it has to be deferred
1468	/// to the completion of the class.
1469	void addedSelectedDestructor(CXXDestructorDecl *DD);
1470
1471	/// Notify the class that an eligible SMF has been added.
1472	/// This updates triviality and destructor based properties of the class accordingly.
1473	void addedEligibleSpecialMemberFunction(const CXXMethodDecl MD, unsigned* SMKind);
1474
1475	/// If this record is an instantiation of a member class,
1476	/// retrieves the member class from which it was instantiated.
1477	///
1478	/// This routine will return non-null for (non-templated) member
1479	/// classes of class templates. For example, given:
1480	///
1481	/// \code
1482	/// template<typename T>
1483	/// struct X {
1484	/// struct A { };
1485	/// };
1486	/// \endcode
1487	///
1488	/// The declaration for X<int>::A is a (non-templated) CXXRecordDecl
1489	/// whose parent is the class template specialization X<int>. For
1490	/// this declaration, getInstantiatedFromMemberClass() will return
1491	/// the CXXRecordDecl X<T>::A. When a complete definition of
1492	/// X<int>::A is required, it will be instantiated from the
1493	/// declaration returned by getInstantiatedFromMemberClass().
1494	CXXRecordDecl getInstantiatedFromMemberClass() const*;
1495
1496	/// If this class is an instantiation of a member class of a
1497	/// class template specialization, retrieves the member specialization
1498	/// information.
1499	MemberSpecializationInfo getMemberSpecializationInfo() const*;
1500
1501	/// Specify that this record is an instantiation of the
1502	/// member class \p RD.
1503	void setInstantiationOfMemberClass(CXXRecordDecl *RD,
1504	TemplateSpecializationKind TSK);
1505
1506	/// Retrieves the class template that is described by this
1507	/// class declaration.
1508	///
1509	/// Every class template is represented as a ClassTemplateDecl and a
1510	/// CXXRecordDecl. The former contains template properties (such as
1511	/// the template parameter lists) while the latter contains the
1512	/// actual description of the template's
1513	/// contents. ClassTemplateDecl::getTemplatedDecl() retrieves the
1514	/// CXXRecordDecl that from a ClassTemplateDecl, while
1515	/// getDescribedClassTemplate() retrieves the ClassTemplateDecl from
1516	/// a CXXRecordDecl.
1517	ClassTemplateDecl getDescribedClassTemplate() const*;
1518
1519	void setDescribedClassTemplate(ClassTemplateDecl *Template);
1520
1521	/// Determine whether this particular class is a specialization or
1522	/// instantiation of a class template or member class of a class template,
1523	/// and how it was instantiated or specialized.
1524	TemplateSpecializationKind getTemplateSpecializationKind() const;
1525
1526	/// Set the kind of specialization or template instantiation this is.
1527	void setTemplateSpecializationKind(TemplateSpecializationKind TSK);
1528
1529	/// Retrieve the record declaration from which this record could be
1530	/// instantiated. Returns null if this class is not a template instantiation.
1531	const CXXRecordDecl getTemplateInstantiationPattern() const*;
1532
1533	CXXRecordDecl *getTemplateInstantiationPattern() {
1534	return const_cast<CXXRecordDecl >(const_cast<const* CXXRecordDecl >(this*)
1535	->getTemplateInstantiationPattern());
1536	}
1537
1538	/// Returns the destructor decl for this class.
1539	CXXDestructorDecl getDestructor() const*;
1540
1541	/// Returns true if the class destructor, or any implicitly invoked
1542	/// destructors are marked noreturn.
1543	bool isAnyDestructorNoReturn() const { return data().IsAnyDestructorNoReturn; }
1544
1545	/// If the class is a local class [class.local], returns
1546	/// the enclosing function declaration.
1547	const FunctionDecl isLocalClass() const* {
1548	if (const auto *RD = dyn_cast<CXXRecordDecl>(getDeclContext()))
1549	return RD->isLocalClass();
1550
1551	return dyn_cast<FunctionDecl>(getDeclContext());
1552	}
1553
1554	FunctionDecl *isLocalClass() {
1555	return const_cast<FunctionDecl*>(
1556	const_cast<const CXXRecordDecl>(this*)->isLocalClass());
1557	}
1558
1559	/// Determine whether this dependent class is a current instantiation,
1560	/// when viewed from within the given context.
1561	bool isCurrentInstantiation(const DeclContext CurContext) const*;
1562
1563	/// Determine whether this class is derived from the class \p Base.
1564	///
1565	/// This routine only determines whether this class is derived from \p Base,
1566	/// but does not account for factors that may make a Derived -> Base class
1567	/// ill-formed, such as private/protected inheritance or multiple, ambiguous
1568	/// base class subobjects.
1569	///
1570	/// \param Base the base class we are searching for.
1571	///
1572	/// \returns true if this class is derived from Base, false otherwise.
1573	bool isDerivedFrom(const CXXRecordDecl Base) const*;
1574
1575	/// Determine whether this class is derived from the type \p Base.
1576	///
1577	/// This routine only determines whether this class is derived from \p Base,
1578	/// but does not account for factors that may make a Derived -> Base class
1579	/// ill-formed, such as private/protected inheritance or multiple, ambiguous
1580	/// base class subobjects.
1581	///
1582	/// \param Base the base class we are searching for.
1583	///
1584	/// \param Paths will contain the paths taken from the current class to the
1585	/// given \p Base class.
1586	///
1587	/// \returns true if this class is derived from \p Base, false otherwise.
1588	///
1589	/// \todo add a separate parameter to configure IsDerivedFrom, rather than
1590	/// tangling input and output in \p Paths
1591	bool isDerivedFrom(const CXXRecordDecl Base, CXXBasePaths &Paths) const*;
1592
1593	/// Determine whether this class is virtually derived from
1594	/// the class \p Base.
1595	///
1596	/// This routine only determines whether this class is virtually
1597	/// derived from \p Base, but does not account for factors that may
1598	/// make a Derived -> Base class ill-formed, such as
1599	/// private/protected inheritance or multiple, ambiguous base class
1600	/// subobjects.
1601	///
1602	/// \param Base the base class we are searching for.
1603	///
1604	/// \returns true if this class is virtually derived from Base,
1605	/// false otherwise.
1606	bool isVirtuallyDerivedFrom(const CXXRecordDecl Base) const*;
1607
1608	/// Determine whether this class is provably not derived from
1609	/// the type \p Base.
1610	bool isProvablyNotDerivedFrom(const CXXRecordDecl Base) const*;
1611
1612	/// Function type used by forallBases() as a callback.
1613	///
1614	/// \param BaseDefinition the definition of the base class
1615	///
1616	/// \returns true if this base matched the search criteria
1617	using ForallBasesCallback =
1618	llvm::function_ref<bool(const CXXRecordDecl *BaseDefinition)>;
1619
1620	/// Determines if the given callback holds for all the direct
1621	/// or indirect base classes of this type.
1622	///
1623	/// The class itself does not count as a base class. This routine
1624	/// returns false if the class has non-computable base classes.
1625	///
1626	/// \param BaseMatches Callback invoked for each (direct or indirect) base
1627	/// class of this type until a call returns false.
1628	bool forallBases(ForallBasesCallback BaseMatches) const;
1629
1630	/// Function type used by lookupInBases() to determine whether a
1631	/// specific base class subobject matches the lookup criteria.
1632	///
1633	/// \param Specifier the base-class specifier that describes the inheritance
1634	/// from the base class we are trying to match.
1635	///
1636	/// \param Path the current path, from the most-derived class down to the
1637	/// base named by the \p Specifier.
1638	///
1639	/// \returns true if this base matched the search criteria, false otherwise.
1640	using BaseMatchesCallback =
1641	llvm::function_ref<bool(const CXXBaseSpecifier *Specifier,
1642	CXXBasePath &Path)>;
1643
1644	/// Look for entities within the base classes of this C++ class,
1645	/// transitively searching all base class subobjects.
1646	///
1647	/// This routine uses the callback function \p BaseMatches to find base
1648	/// classes meeting some search criteria, walking all base class subobjects
1649	/// and populating the given \p Paths structure with the paths through the
1650	/// inheritance hierarchy that resulted in a match. On a successful search,
1651	/// the \p Paths structure can be queried to retrieve the matching paths and
1652	/// to determine if there were any ambiguities.
1653	///
1654	/// \param BaseMatches callback function used to determine whether a given
1655	/// base matches the user-defined search criteria.
1656	///
1657	/// \param Paths used to record the paths from this class to its base class
1658	/// subobjects that match the search criteria.
1659	///
1660	/// \param LookupInDependent can be set to true to extend the search to
1661	/// dependent base classes.
1662	///
1663	/// \returns true if there exists any path from this class to a base class
1664	/// subobject that matches the search criteria.
1665	bool lookupInBases(BaseMatchesCallback BaseMatches, CXXBasePaths &Paths,
1666	bool LookupInDependent = false) const;
1667
1668	/// Base-class lookup callback that determines whether the given
1669	/// base class specifier refers to a specific class declaration.
1670	///
1671	/// This callback can be used with \c lookupInBases() to determine whether
1672	/// a given derived class has is a base class subobject of a particular type.
1673	/// The base record pointer should refer to the canonical CXXRecordDecl of the
1674	/// base class that we are searching for.
1675	static bool FindBaseClass(const CXXBaseSpecifier *Specifier,
1676	CXXBasePath &Path, const CXXRecordDecl *BaseRecord);
1677
1678	/// Base-class lookup callback that determines whether the
1679	/// given base class specifier refers to a specific class
1680	/// declaration and describes virtual derivation.
1681	///
1682	/// This callback can be used with \c lookupInBases() to determine
1683	/// whether a given derived class has is a virtual base class
1684	/// subobject of a particular type. The base record pointer should
1685	/// refer to the canonical CXXRecordDecl of the base class that we
1686	/// are searching for.
1687	static bool FindVirtualBaseClass(const CXXBaseSpecifier *Specifier,
1688	CXXBasePath &Path,
1689	const CXXRecordDecl *BaseRecord);
1690
1691	/// Retrieve the final overriders for each virtual member
1692	/// function in the class hierarchy where this class is the
1693	/// most-derived class in the class hierarchy.
1694	void getFinalOverriders(CXXFinalOverriderMap &FinaOverriders) const;
1695
1696	/// Get the indirect primary bases for this class.
1697	void getIndirectPrimaryBases(CXXIndirectPrimaryBaseSet& Bases) const;
1698
1699	/// Determine whether this class has a member with the given name, possibly
1700	/// in a non-dependent base class.
1701	///
1702	/// No check for ambiguity is performed, so this should never be used when
1703	/// implementing language semantics, but it may be appropriate for warnings,
1704	/// static analysis, or similar.
1705	bool hasMemberName(DeclarationName N) const;
1706
1707	/// Performs an imprecise lookup of a dependent name in this class.
1708	///
1709	/// This function does not follow strict semantic rules and should be used
1710	/// only when lookup rules can be relaxed, e.g. indexing.
1711	std::vector<const NamedDecl *>
1712	lookupDependentName(DeclarationName Name,
1713	llvm::function_ref<bool(const NamedDecl *ND)> Filter);
1714
1715	/// Renders and displays an inheritance diagram
1716	/// for this C++ class and all of its base classes (transitively) using
1717	/// GraphViz.
1718	void viewInheritance(ASTContext& Context) const;
1719
1720	/// Calculates the access of a decl that is reached
1721	/// along a path.
1722	static AccessSpecifier MergeAccess(AccessSpecifier PathAccess,
1723	AccessSpecifier DeclAccess) {
1724	assert(DeclAccess != AS_none);
1725	if (DeclAccess == AS_private) return AS_none;
1726	return (PathAccess > DeclAccess ? PathAccess : DeclAccess);
1727	}
1728
1729	/// Indicates that the declaration of a defaulted or deleted special
1730	/// member function is now complete.
1731	void finishedDefaultedOrDeletedMember(CXXMethodDecl *MD);
1732
1733	void setTrivialForCallFlags(CXXMethodDecl *MD);
1734
1735	/// Indicates that the definition of this class is now complete.
1736	void completeDefinition() override;
1737
1738	/// Indicates that the definition of this class is now complete,
1739	/// and provides a final overrider map to help determine
1740	///
1741	/// \param FinalOverriders The final overrider map for this class, which can
1742	/// be provided as an optimization for abstract-class checking. If NULL,
1743	/// final overriders will be computed if they are needed to complete the
1744	/// definition.
1745	void completeDefinition(CXXFinalOverriderMap *FinalOverriders);
1746
1747	/// Determine whether this class may end up being abstract, even though
1748	/// it is not yet known to be abstract.
1749	///
1750	/// \returns true if this class is not known to be abstract but has any
1751	/// base classes that are abstract. In this case, \c completeDefinition()
1752	/// will need to compute final overriders to determine whether the class is
1753	/// actually abstract.
1754	bool mayBeAbstract() const;
1755
1756	/// Determine whether it's impossible for a class to be derived from this
1757	/// class. This is best-effort, and may conservatively return false.
1758	bool isEffectivelyFinal() const;
1759
1760	/// If this is the closure type of a lambda expression, retrieve the
1761	/// number to be used for name mangling in the Itanium C++ ABI.
1762	///
1763	/// Zero indicates that this closure type has internal linkage, so the
1764	/// mangling number does not matter, while a non-zero value indicates which
1765	/// lambda expression this is in this particular context.
1766	unsigned getLambdaManglingNumber() const {
1767	assert(isLambda() && "Not a lambda closure type!");
1768	return getLambdaData().ManglingNumber;
1769	}
1770
1771	/// The lambda is known to has internal linkage no matter whether it has name
1772	/// mangling number.
1773	bool hasKnownLambdaInternalLinkage() const {
1774	assert(isLambda() && "Not a lambda closure type!");
1775	return getLambdaData().HasKnownInternalLinkage;
1776	}
1777
1778	/// Retrieve the declaration that provides additional context for a
1779	/// lambda, when the normal declaration context is not specific enough.
1780	///
1781	/// Certain contexts (default arguments of in-class function parameters and
1782	/// the initializers of data members) have separate name mangling rules for
1783	/// lambdas within the Itanium C++ ABI. For these cases, this routine provides
1784	/// the declaration in which the lambda occurs, e.g., the function parameter
1785	/// or the non-static data member. Otherwise, it returns NULL to imply that
1786	/// the declaration context suffices.
1787	Decl getLambdaContextDecl() const*;
1788
1789	/// Retrieve the index of this lambda within the context declaration returned
1790	/// by getLambdaContextDecl().
1791	unsigned getLambdaIndexInContext() const {
1792	assert(isLambda() && "Not a lambda closure type!");
1793	return getLambdaData().IndexInContext;
1794	}
1795
1796	/// Information about how a lambda is numbered within its context.
1797	struct LambdaNumbering {
1798	Decl ContextDecl = nullptr*;
1799	unsigned IndexInContext = `0`;
1800	unsigned ManglingNumber = `0`;
1801	unsigned DeviceManglingNumber = `0`;
1802	bool HasKnownInternalLinkage = false;
1803	};
1804
1805	/// Set the mangling numbers and context declaration for a lambda class.
1806	void setLambdaNumbering(LambdaNumbering Numbering);
1807
1808	// Get the mangling numbers and context declaration for a lambda class.
1809	LambdaNumbering getLambdaNumbering() const {
1810	return {.ContextDecl: getLambdaContextDecl(), .IndexInContext: getLambdaIndexInContext(),
1811	.ManglingNumber: getLambdaManglingNumber(), .DeviceManglingNumber: getDeviceLambdaManglingNumber(),
1812	.HasKnownInternalLinkage: hasKnownLambdaInternalLinkage()};
1813	}
1814
1815	/// Retrieve the device side mangling number.
1816	unsigned getDeviceLambdaManglingNumber() const;
1817
1818	/// Returns the inheritance model used for this record.
1819	MSInheritanceModel getMSInheritanceModel() const;
1820
1821	/// Calculate what the inheritance model would be for this class.
1822	MSInheritanceModel calculateInheritanceModel() const;
1823
1824	/// In the Microsoft C++ ABI, use zero for the field offset of a null data
1825	/// member pointer if we can guarantee that zero is not a valid field offset,
1826	/// or if the member pointer has multiple fields. Polymorphic classes have a
1827	/// vfptr at offset zero, so we can use zero for null. If there are multiple
1828	/// fields, we can use zero even if it is a valid field offset because
1829	/// null-ness testing will check the other fields.
1830	bool nullFieldOffsetIsZero() const;
1831
1832	/// Controls when vtordisps will be emitted if this record is used as a
1833	/// virtual base.
1834	MSVtorDispMode getMSVtorDispMode() const;
1835
1836	/// Determine whether this lambda expression was known to be dependent
1837	/// at the time it was created, even if its context does not appear to be
1838	/// dependent.
1839	///
1840	/// This flag is a workaround for an issue with parsing, where default
1841	/// arguments are parsed before their enclosing function declarations have
1842	/// been created. This means that any lambda expressions within those
1843	/// default arguments will have as their DeclContext the context enclosing
1844	/// the function declaration, which may be non-dependent even when the
1845	/// function declaration itself is dependent. This flag indicates when we
1846	/// know that the lambda is dependent despite that.
1847	bool isDependentLambda() const {
1848	return isLambda() && getLambdaData().DependencyKind == LDK_AlwaysDependent;
1849	}
1850
1851	bool isNeverDependentLambda() const {
1852	return isLambda() && getLambdaData().DependencyKind == LDK_NeverDependent;
1853	}
1854
1855	unsigned getLambdaDependencyKind() const {
1856	if (!isLambda())
1857	return LDK_Unknown;
1858	return getLambdaData().DependencyKind;
1859	}
1860
1861	TypeSourceInfo getLambdaTypeInfo() const* {
1862	return getLambdaData().MethodTyInfo;
1863	}
1864
1865	void setLambdaTypeInfo(TypeSourceInfo *TS) {
1866	assert(DefinitionData && DefinitionData->IsLambda &&
1867	"setting lambda property of non-lambda class");
1868	auto &DL = static_cast<LambdaDefinitionData &>(*DefinitionData);
1869	DL.MethodTyInfo = TS;
1870	}
1871
1872	void setLambdaDependencyKind(unsigned Kind) {
1873	getLambdaData().DependencyKind = Kind;
1874	}
1875
1876	void setLambdaIsGeneric(bool IsGeneric) {
1877	assert(DefinitionData && DefinitionData->IsLambda &&
1878	"setting lambda property of non-lambda class");
1879	auto &DL = static_cast<LambdaDefinitionData &>(*DefinitionData);
1880	DL.IsGenericLambda = IsGeneric;
1881	}
1882
1883	// Determine whether this type is an Interface Like type for
1884	// __interface inheritance purposes.
1885	bool isInterfaceLike() const;
1886
1887	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
1888	static bool classofKind(Kind K) {
1889	return K >= firstCXXRecord && K <= lastCXXRecord;
1890	}
1891	void markAbstract() { data().Abstract = true; }
1892	};
1893
1894	/// Store information needed for an explicit specifier.
1895	/// Used by CXXDeductionGuideDecl, CXXConstructorDecl and CXXConversionDecl.
1896	class ExplicitSpecifier {
1897	llvm::PointerIntPair<Expr *, `2`, ExplicitSpecKind> ExplicitSpec{
1898	nullptr, ExplicitSpecKind::ResolvedFalse};
1899
1900	public:
1901	ExplicitSpecifier() = default;
1902	ExplicitSpecifier(Expr *Expression, ExplicitSpecKind Kind)
1903	: ExplicitSpec (Expression, Kind) {}
1904	ExplicitSpecKind getKind() const { return ExplicitSpec.getInt(); }
1905	const Expr getExpr() const* { return ExplicitSpec.getPointer(); }
1906	Expr getExpr() { return* ExplicitSpec.getPointer(); }
1907
1908	/// Determine if the declaration had an explicit specifier of any kind.
1909	bool isSpecified() const {
1910	return ExplicitSpec.getInt() != ExplicitSpecKind::ResolvedFalse \|\|
1911	ExplicitSpec.getPointer();
1912	}
1913
1914	/// Check for equivalence of explicit specifiers.
1915	/// \return true if the explicit specifier are equivalent, false otherwise.
1916	bool isEquivalent(const ExplicitSpecifier Other) const;
1917	/// Determine whether this specifier is known to correspond to an explicit
1918	/// declaration. Returns false if the specifier is absent or has an
1919	/// expression that is value-dependent or evaluates to false.
1920	bool isExplicit() const {
1921	return ExplicitSpec.getInt() == ExplicitSpecKind::ResolvedTrue;
1922	}
1923	/// Determine if the explicit specifier is invalid.
1924	/// This state occurs after a substitution failures.
1925	bool isInvalid() const {
1926	return ExplicitSpec.getInt() == ExplicitSpecKind::Unresolved &&
1927	!ExplicitSpec.getPointer();
1928	}
1929	void setKind(ExplicitSpecKind Kind) { ExplicitSpec.setInt(Kind); }
1930	void setExpr(Expr *E) { ExplicitSpec.setPointer(E); }
1931	// Retrieve the explicit specifier in the given declaration, if any.
1932	static ExplicitSpecifier getFromDecl(FunctionDecl *Function);
1933	static const ExplicitSpecifier getFromDecl(const FunctionDecl *Function) {
1934	return getFromDecl(Function: const_cast<FunctionDecl *>(Function));
1935	}
1936	static ExplicitSpecifier Invalid() {
1937	return ExplicitSpecifier (nullptr, ExplicitSpecKind::Unresolved);
1938	}
1939	};
1940
1941	/// Represents a C++ deduction guide declaration.
1942	///
1943	/// \code
1944	/// template<typename T> struct A { A(); A(T); };
1945	/// A() -> A<int>;
1946	/// \endcode
1947	///
1948	/// In this example, there will be an explicit deduction guide from the
1949	/// second line, and implicit deduction guide templates synthesized from
1950	/// the constructors of \c A.
1951	class CXXDeductionGuideDecl : public FunctionDecl {
1952	void anchor() override;
1953
1954	private:
1955	CXXDeductionGuideDecl(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
1956	ExplicitSpecifier ES,
1957	const DeclarationNameInfo &NameInfo, QualType T,
1958	TypeSourceInfo *TInfo, SourceLocation EndLocation,
1959	CXXConstructorDecl *Ctor, DeductionCandidate Kind)
1960	: FunctionDecl(CXXDeductionGuide, C, DC, StartLoc, NameInfo, T, TInfo,
1961	SC_None, false, false, ConstexprSpecKind::Unspecified),
1962	Ctor(Ctor), ExplicitSpec (ES) {
1963	if (EndLocation.isValid())
1964	setRangeEnd(EndLocation);
1965	setDeductionCandidateKind(Kind);
1966	}
1967
1968	CXXConstructorDecl *Ctor;
1969	ExplicitSpecifier ExplicitSpec;
1970	void setExplicitSpecifier(ExplicitSpecifier ES) { ExplicitSpec = ES; }
1971
1972	public:
1973	friend class ASTDeclReader;
1974	friend class ASTDeclWriter;
1975
1976	static CXXDeductionGuideDecl *
1977	Create(ASTContext &C, DeclContext *DC, SourceLocation StartLoc,
1978	ExplicitSpecifier ES, const DeclarationNameInfo &NameInfo, QualType T,
1979	TypeSourceInfo *TInfo, SourceLocation EndLocation,
1980	CXXConstructorDecl Ctor = nullptr*,
1981	DeductionCandidate Kind = DeductionCandidate::Normal);
1982
1983	static CXXDeductionGuideDecl *CreateDeserialized(ASTContext &C, DeclID ID);
1984
1985	ExplicitSpecifier getExplicitSpecifier() { return ExplicitSpec; }
1986	const ExplicitSpecifier getExplicitSpecifier() const { return ExplicitSpec; }
1987
1988	/// Return true if the declaration is already resolved to be explicit.
1989	bool isExplicit() const { return ExplicitSpec.isExplicit(); }
1990
1991	/// Get the template for which this guide performs deduction.
1992	TemplateDecl getDeducedTemplate() const* {
1993	return getDeclName().getCXXDeductionGuideTemplate();
1994	}
1995
1996	/// Get the constructor from which this deduction guide was generated, if
1997	/// this is an implicit deduction guide.
1998	CXXConstructorDecl getCorrespondingConstructor() const* { return Ctor; }
1999
2000	void setDeductionCandidateKind(DeductionCandidate K) {
2001	FunctionDeclBits.DeductionCandidateKind = static_cast<unsigned char>(K);
2002	}
2003
2004	DeductionCandidate getDeductionCandidateKind() const {
2005	return static_cast<DeductionCandidate>(
2006	FunctionDeclBits.DeductionCandidateKind);
2007	}
2008
2009	// Implement isa/cast/dyncast/etc.
2010	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
2011	static bool classofKind(Kind K) { return K == CXXDeductionGuide; }
2012	};
2013
2014	/// \brief Represents the body of a requires-expression.
2015	///
2016	/// This decl exists merely to serve as the DeclContext for the local
2017	/// parameters of the requires expression as well as other declarations inside
2018	/// it.
2019	///
2020	/// \code
2021	/// template<typename T> requires requires (T t) { {t++} -> regular; }
2022	/// \endcode
2023	///
2024	/// In this example, a RequiresExpr object will be generated for the expression,
2025	/// and a RequiresExprBodyDecl will be created to hold the parameter t and the
2026	/// template argument list imposed by the compound requirement.
2027	class RequiresExprBodyDecl : public Decl, public DeclContext {
2028	RequiresExprBodyDecl(ASTContext &C, DeclContext *DC, SourceLocation StartLoc)
2029	: Decl(RequiresExprBody, DC, StartLoc), DeclContext(RequiresExprBody) {}
2030
2031	public:
2032	friend class ASTDeclReader;
2033	friend class ASTDeclWriter;
2034
2035	static RequiresExprBodyDecl Create(ASTContext &C, DeclContext DC,
2036	SourceLocation StartLoc);
2037
2038	static RequiresExprBodyDecl *CreateDeserialized(ASTContext &C, DeclID ID);
2039
2040	// Implement isa/cast/dyncast/etc.
2041	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
2042	static bool classofKind(Kind K) { return K == RequiresExprBody; }
2043
2044	static DeclContext castToDeclContext(const* RequiresExprBodyDecl *D) {
2045	return static_cast<DeclContext >(const_cast<RequiresExprBodyDecl >(D));
2046	}
2047
2048	static RequiresExprBodyDecl castFromDeclContext(const* DeclContext *DC) {
2049	return static_cast<RequiresExprBodyDecl >(const_cast<DeclContext >(DC));
2050	}
2051	};
2052
2053	/// Represents a static or instance method of a struct/union/class.
2054	///
2055	/// In the terminology of the C++ Standard, these are the (static and
2056	/// non-static) member functions, whether virtual or not.
2057	class CXXMethodDecl : public FunctionDecl {
2058	void anchor() override;
2059
2060	protected:
2061	CXXMethodDecl(Kind DK, ASTContext &C, CXXRecordDecl *RD,
2062	SourceLocation StartLoc, const DeclarationNameInfo &NameInfo,
2063	QualType T, TypeSourceInfo *TInfo, StorageClass SC,
2064	bool UsesFPIntrin, bool isInline,
2065	ConstexprSpecKind ConstexprKind, SourceLocation EndLocation,
2066	Expr TrailingRequiresClause = nullptr*)
2067	: FunctionDecl(DK, C, RD, StartLoc, NameInfo, T, TInfo, SC, UsesFPIntrin,
2068	isInline, ConstexprKind, TrailingRequiresClause) {
2069	if (EndLocation.isValid())
2070	setRangeEnd(EndLocation);
2071	}
2072
2073	public:
2074	static CXXMethodDecl *
2075	Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2076	const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2077	StorageClass SC, bool UsesFPIntrin, bool isInline,
2078	ConstexprSpecKind ConstexprKind, SourceLocation EndLocation,
2079	Expr TrailingRequiresClause = nullptr*);
2080
2081	static CXXMethodDecl *CreateDeserialized(ASTContext &C, DeclID ID);
2082
2083	bool isStatic() const;
2084	bool isInstance() const { return !isStatic(); }
2085
2086	/// [C++2b][dcl.fct]/p7
2087	/// An explicit object member function is a non-static
2088	/// member function with an explicit object parameter. e.g.,
2089	/// void func(this SomeType);
2090	bool isExplicitObjectMemberFunction() const;
2091
2092	/// [C++2b][dcl.fct]/p7
2093	/// An implicit object member function is a non-static
2094	/// member function without an explicit object parameter.
2095	bool isImplicitObjectMemberFunction() const;
2096
2097	/// Returns true if the given operator is implicitly static in a record
2098	/// context.
2099	static bool isStaticOverloadedOperator(OverloadedOperatorKind OOK) {
2100	// [class.free]p1:
2101	// Any allocation function for a class T is a static member
2102	// (even if not explicitly declared static).
2103	// [class.free]p6 Any deallocation function for a class X is a static member
2104	// (even if not explicitly declared static).
2105	return OOK == OO_New \|\| OOK == OO_Array_New \|\| OOK == OO_Delete \|\|
2106	OOK == OO_Array_Delete;
2107	}
2108
2109	bool isConst() const { return getType()->castAs<FunctionType>()->isConst(); }
2110	bool isVolatile() const { return getType()->castAs<FunctionType>()->isVolatile(); }
2111
2112	bool isVirtual() const {
2113	CXXMethodDecl CD = const_cast<CXXMethodDecl>(this)->getCanonicalDecl();
2114
2115	// Member function is virtual if it is marked explicitly so, or if it is
2116	// declared in __interface -- then it is automatically pure virtual.
2117	if (CD->isVirtualAsWritten() \|\| CD->isPureVirtual())
2118	return true;
2119
2120	return CD->size_overridden_methods() != `0`;
2121	}
2122
2123	/// If it's possible to devirtualize a call to this method, return the called
2124	/// function. Otherwise, return null.
2125
2126	/// \param Base The object on which this virtual function is called.
2127	/// \param IsAppleKext True if we are compiling for Apple kext.
2128	CXXMethodDecl getDevirtualizedMethod(const* Expr Base, bool* IsAppleKext);
2129
2130	const CXXMethodDecl getDevirtualizedMethod(const* Expr *Base,
2131	bool IsAppleKext) const {
2132	return const_cast<CXXMethodDecl >(this*)->getDevirtualizedMethod(
2133	Base, IsAppleKext);
2134	}
2135
2136	/// Determine whether this is a usual deallocation function (C++
2137	/// [basic.stc.dynamic.deallocation]p2), which is an overloaded delete or
2138	/// delete[] operator with a particular signature. Populates \p PreventedBy
2139	/// with the declarations of the functions of the same kind if they were the
2140	/// reason for this function returning false. This is used by
2141	/// Sema::isUsualDeallocationFunction to reconsider the answer based on the
2142	/// context.
2143	bool isUsualDeallocationFunction(
2144	SmallVectorImpl<const FunctionDecl > &PreventedBy) const*;
2145
2146	/// Determine whether this is a copy-assignment operator, regardless
2147	/// of whether it was declared implicitly or explicitly.
2148	bool isCopyAssignmentOperator() const;
2149
2150	/// Determine whether this is a move assignment operator.
2151	bool isMoveAssignmentOperator() const;
2152
2153	CXXMethodDecl *getCanonicalDecl() override {
2154	return cast<CXXMethodDecl>(FunctionDecl::getCanonicalDecl());
2155	}
2156	const CXXMethodDecl getCanonicalDecl() const* {
2157	return const_cast<CXXMethodDecl>(this*)->getCanonicalDecl();
2158	}
2159
2160	CXXMethodDecl *getMostRecentDecl() {
2161	return cast<CXXMethodDecl>(
2162	static_cast<FunctionDecl >(this*)->getMostRecentDecl());
2163	}
2164	const CXXMethodDecl getMostRecentDecl() const* {
2165	return const_cast<CXXMethodDecl>(this*)->getMostRecentDecl();
2166	}
2167
2168	void addOverriddenMethod(const CXXMethodDecl *MD);
2169
2170	using method_iterator = const CXXMethodDecl *const *;
2171
2172	method_iterator begin_overridden_methods() const;
2173	method_iterator end_overridden_methods() const;
2174	unsigned size_overridden_methods() const;
2175
2176	using overridden_method_range = llvm::iterator_range<
2177	llvm::TinyPtrVector<const CXXMethodDecl *>::const_iterator>;
2178
2179	overridden_method_range overridden_methods() const;
2180
2181	/// Return the parent of this method declaration, which
2182	/// is the class in which this method is defined.
2183	const CXXRecordDecl getParent() const* {
2184	return cast<CXXRecordDecl>(FunctionDecl::getParent());
2185	}
2186
2187	/// Return the parent of this method declaration, which
2188	/// is the class in which this method is defined.
2189	CXXRecordDecl *getParent() {
2190	return const_cast<CXXRecordDecl *>(
2191	cast<CXXRecordDecl>(FunctionDecl::getParent()));
2192	}
2193
2194	/// Return the type of the \c this pointer.
2195	///
2196	/// Should only be called for instance (i.e., non-static) methods. Note
2197	/// that for the call operator of a lambda closure type, this returns the
2198	/// desugared 'this' type (a pointer to the closure type), not the captured
2199	/// 'this' type.
2200	QualType getThisType() const;
2201
2202	/// Return the type of the object pointed by \c this.
2203	///
2204	/// See getThisType() for usage restriction.
2205
2206	QualType getFunctionObjectParameterReferenceType() const;
2207	QualType getFunctionObjectParameterType() const {
2208	return getFunctionObjectParameterReferenceType().getNonReferenceType();
2209	}
2210
2211	unsigned getNumExplicitParams() const {
2212	return getNumParams() - (isExplicitObjectMemberFunction() ? `1` : `0`);
2213	}
2214
2215	static QualType getThisType(const FunctionProtoType *FPT,
2216	const CXXRecordDecl *Decl);
2217
2218	Qualifiers getMethodQualifiers() const {
2219	return getType()->castAs<FunctionProtoType>()->getMethodQuals();
2220	}
2221
2222	/// Retrieve the ref-qualifier associated with this method.
2223	///
2224	/// In the following example, \c f() has an lvalue ref-qualifier, \c g()
2225	/// has an rvalue ref-qualifier, and \c h() has no ref-qualifier.
2226	/// @code
2227	/// struct X {
2228	/// void f() &;
2229	/// void g() &&;
2230	/// void h();
2231	/// };
2232	/// @endcode
2233	RefQualifierKind getRefQualifier() const {
2234	return getType()->castAs<FunctionProtoType>()->getRefQualifier();
2235	}
2236
2237	bool hasInlineBody() const;
2238
2239	/// Determine whether this is a lambda closure type's static member
2240	/// function that is used for the result of the lambda's conversion to
2241	/// function pointer (for a lambda with no captures).
2242	///
2243	/// The function itself, if used, will have a placeholder body that will be
2244	/// supplied by IR generation to either forward to the function call operator
2245	/// or clone the function call operator.
2246	bool isLambdaStaticInvoker() const;
2247
2248	/// Find the method in \p RD that corresponds to this one.
2249	///
2250	/// Find if \p RD or one of the classes it inherits from override this method.
2251	/// If so, return it. \p RD is assumed to be a subclass of the class defining
2252	/// this method (or be the class itself), unless \p MayBeBase is set to true.
2253	CXXMethodDecl *
2254	getCorrespondingMethodInClass(const CXXRecordDecl *RD,
2255	bool MayBeBase = false);
2256
2257	const CXXMethodDecl *
2258	getCorrespondingMethodInClass(const CXXRecordDecl *RD,
2259	bool MayBeBase = false) const {
2260	return const_cast<CXXMethodDecl >(this*)
2261	->getCorrespondingMethodInClass(RD, MayBeBase);
2262	}
2263
2264	/// Find if \p RD declares a function that overrides this function, and if so,
2265	/// return it. Does not search base classes.
2266	CXXMethodDecl getCorrespondingMethodDeclaredInClass(const* CXXRecordDecl *RD,
2267	bool MayBeBase = false);
2268	const CXXMethodDecl *
2269	getCorrespondingMethodDeclaredInClass(const CXXRecordDecl *RD,
2270	bool MayBeBase = false) const {
2271	return const_cast<CXXMethodDecl >(this*)
2272	->getCorrespondingMethodDeclaredInClass(RD, MayBeBase);
2273	}
2274
2275	// Implement isa/cast/dyncast/etc.
2276	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
2277	static bool classofKind(Kind K) {
2278	return K >= firstCXXMethod && K <= lastCXXMethod;
2279	}
2280	};
2281
2282	/// Represents a C++ base or member initializer.
2283	///
2284	/// This is part of a constructor initializer that
2285	/// initializes one non-static member variable or one base class. For
2286	/// example, in the following, both 'A(a)' and 'f(3.14159)' are member
2287	/// initializers:
2288	///
2289	/// \code
2290	/// class A { };
2291	/// class B : public A {
2292	/// float f;
2293	/// public:
2294	/// B(A& a) : A(a), f(3.14159) { }
2295	/// };
2296	/// \endcode
2297	class CXXCtorInitializer final {
2298	/// Either the base class name/delegating constructor type (stored as
2299	/// a TypeSourceInfo), an normal field (FieldDecl), or an anonymous field*
2300	/// (IndirectFieldDecl) being initialized.*
2301	llvm::PointerUnion<TypeSourceInfo , FieldDecl , IndirectFieldDecl *>
2302	Initializee;
2303
2304	/// The argument used to initialize the base or member, which may
2305	/// end up constructing an object (when multiple arguments are involved).
2306	Stmt *Init;
2307
2308	/// The source location for the field name or, for a base initializer
2309	/// pack expansion, the location of the ellipsis.
2310	///
2311	/// In the case of a delegating
2312	/// constructor, it will still include the type's source location as the
2313	/// Initializee points to the CXXConstructorDecl (to allow loop detection).
2314	SourceLocation MemberOrEllipsisLocation;
2315
2316	/// Location of the left paren of the ctor-initializer.
2317	SourceLocation LParenLoc;
2318
2319	/// Location of the right paren of the ctor-initializer.
2320	SourceLocation RParenLoc;
2321
2322	/// If the initializee is a type, whether that type makes this
2323	/// a delegating initialization.
2324	LLVM_PREFERRED_TYPE(bool)
2325	unsigned IsDelegating : `1`;
2326
2327	/// If the initializer is a base initializer, this keeps track
2328	/// of whether the base is virtual or not.
2329	LLVM_PREFERRED_TYPE(bool)
2330	unsigned IsVirtual : `1`;
2331
2332	/// Whether or not the initializer is explicitly written
2333	/// in the sources.
2334	LLVM_PREFERRED_TYPE(bool)
2335	unsigned IsWritten : `1`;
2336
2337	/// If IsWritten is true, then this number keeps track of the textual order
2338	/// of this initializer in the original sources, counting from 0.
2339	unsigned SourceOrder : `13`;
2340
2341	public:
2342	/// Creates a new base-class initializer.
2343	explicit
2344	CXXCtorInitializer(ASTContext &Context, TypeSourceInfo TInfo, bool* IsVirtual,
2345	SourceLocation L, Expr *Init, SourceLocation R,
2346	SourceLocation EllipsisLoc);
2347
2348	/// Creates a new member initializer.
2349	explicit
2350	CXXCtorInitializer(ASTContext &Context, FieldDecl *Member,
2351	SourceLocation MemberLoc, SourceLocation L, Expr *Init,
2352	SourceLocation R);
2353
2354	/// Creates a new anonymous field initializer.
2355	explicit
2356	CXXCtorInitializer(ASTContext &Context, IndirectFieldDecl *Member,
2357	SourceLocation MemberLoc, SourceLocation L, Expr *Init,
2358	SourceLocation R);
2359
2360	/// Creates a new delegating initializer.
2361	explicit
2362	CXXCtorInitializer(ASTContext &Context, TypeSourceInfo *TInfo,
2363	SourceLocation L, Expr *Init, SourceLocation R);
2364
2365	/// \return Unique reproducible object identifier.
2366	int64_t getID(const ASTContext &Context) const;
2367
2368	/// Determine whether this initializer is initializing a base class.
2369	bool isBaseInitializer() const {
2370	return Initializee.is<TypeSourceInfo*>() && !IsDelegating;
2371	}
2372
2373	/// Determine whether this initializer is initializing a non-static
2374	/// data member.
2375	bool isMemberInitializer() const { return Initializee.is<FieldDecl*>(); }
2376
2377	bool isAnyMemberInitializer() const {
2378	return isMemberInitializer() \|\| isIndirectMemberInitializer();
2379	}
2380
2381	bool isIndirectMemberInitializer() const {
2382	return Initializee.is<IndirectFieldDecl*>();
2383	}
2384
2385	/// Determine whether this initializer is an implicit initializer
2386	/// generated for a field with an initializer defined on the member
2387	/// declaration.
2388	///
2389	/// In-class member initializers (also known as "non-static data member
2390	/// initializations", NSDMIs) were introduced in C++11.
2391	bool isInClassMemberInitializer() const {
2392	return Init->getStmtClass() == Stmt::CXXDefaultInitExprClass;
2393	}
2394
2395	/// Determine whether this initializer is creating a delegating
2396	/// constructor.
2397	bool isDelegatingInitializer() const {
2398	return Initializee.is<TypeSourceInfo*>() && IsDelegating;
2399	}
2400
2401	/// Determine whether this initializer is a pack expansion.
2402	bool isPackExpansion() const {
2403	return isBaseInitializer() && MemberOrEllipsisLocation.isValid();
2404	}
2405
2406	// For a pack expansion, returns the location of the ellipsis.
2407	SourceLocation getEllipsisLoc() const {
2408	if (!isPackExpansion())
2409	return {};
2410	return MemberOrEllipsisLocation;
2411	}
2412
2413	/// If this is a base class initializer, returns the type of the
2414	/// base class with location information. Otherwise, returns an NULL
2415	/// type location.
2416	TypeLoc getBaseClassLoc() const;
2417
2418	/// If this is a base class initializer, returns the type of the base class.
2419	/// Otherwise, returns null.
2420	const Type getBaseClass() const*;
2421
2422	/// Returns whether the base is virtual or not.
2423	bool isBaseVirtual() const {
2424	assert(isBaseInitializer() && "Must call this on base initializer!");
2425
2426	return IsVirtual;
2427	}
2428
2429	/// Returns the declarator information for a base class or delegating
2430	/// initializer.
2431	TypeSourceInfo getTypeSourceInfo() const* {
2432	return Initializee.dyn_cast<TypeSourceInfo *>();
2433	}
2434
2435	/// If this is a member initializer, returns the declaration of the
2436	/// non-static data member being initialized. Otherwise, returns null.
2437	FieldDecl getMember() const* {
2438	if (isMemberInitializer())
2439	return Initializee.get<FieldDecl*>();
2440	return nullptr;
2441	}
2442
2443	FieldDecl getAnyMember() const* {
2444	if (isMemberInitializer())
2445	return Initializee.get<FieldDecl*>();
2446	if (isIndirectMemberInitializer())
2447	return Initializee.get<IndirectFieldDecl*>()->getAnonField();
2448	return nullptr;
2449	}
2450
2451	IndirectFieldDecl getIndirectMember() const* {
2452	if (isIndirectMemberInitializer())
2453	return Initializee.get<IndirectFieldDecl*>();
2454	return nullptr;
2455	}
2456
2457	SourceLocation getMemberLocation() const {
2458	return MemberOrEllipsisLocation;
2459	}
2460
2461	/// Determine the source location of the initializer.
2462	SourceLocation getSourceLocation() const;
2463
2464	/// Determine the source range covering the entire initializer.
2465	SourceRange getSourceRange() const LLVM_READONLY;
2466
2467	/// Determine whether this initializer is explicitly written
2468	/// in the source code.
2469	bool isWritten() const { return IsWritten; }
2470
2471	/// Return the source position of the initializer, counting from 0.
2472	/// If the initializer was implicit, -1 is returned.
2473	int getSourceOrder() const {
2474	return IsWritten ? static_cast<int>(SourceOrder) : -`1`;
2475	}
2476
2477	/// Set the source order of this initializer.
2478	///
2479	/// This can only be called once for each initializer; it cannot be called
2480	/// on an initializer having a positive number of (implicit) array indices.
2481	///
2482	/// This assumes that the initializer was written in the source code, and
2483	/// ensures that isWritten() returns true.
2484	void setSourceOrder(int Pos) {
2485	assert(!IsWritten &&
2486	"setSourceOrder() used on implicit initializer");
2487	assert(SourceOrder == `0` &&
2488	"calling twice setSourceOrder() on the same initializer");
2489	assert(Pos >= `0` &&
2490	"setSourceOrder() used to make an initializer implicit");
2491	IsWritten = true;
2492	SourceOrder = static_cast<unsigned>(Pos);
2493	}
2494
2495	SourceLocation getLParenLoc() const { return LParenLoc; }
2496	SourceLocation getRParenLoc() const { return RParenLoc; }
2497
2498	/// Get the initializer.
2499	Expr getInit() const* { return static_cast<Expr *>(Init); }
2500	};
2501
2502	/// Description of a constructor that was inherited from a base class.
2503	class InheritedConstructor {
2504	ConstructorUsingShadowDecl Shadow = nullptr*;
2505	CXXConstructorDecl BaseCtor = nullptr*;
2506
2507	public:
2508	InheritedConstructor() = default;
2509	InheritedConstructor(ConstructorUsingShadowDecl *Shadow,
2510	CXXConstructorDecl *BaseCtor)
2511	: Shadow(Shadow), BaseCtor(BaseCtor) {}
2512
2513	explicit operator bool() const { return Shadow; }
2514
2515	ConstructorUsingShadowDecl getShadowDecl() const* { return Shadow; }
2516	CXXConstructorDecl getConstructor() const* { return BaseCtor; }
2517	};
2518
2519	/// Represents a C++ constructor within a class.
2520	///
2521	/// For example:
2522	///
2523	/// \code
2524	/// class X {
2525	/// public:
2526	/// explicit X(int); // represented by a CXXConstructorDecl.
2527	/// };
2528	/// \endcode
2529	class CXXConstructorDecl final
2530	: public CXXMethodDecl,
2531	private llvm::TrailingObjects<CXXConstructorDecl, InheritedConstructor,
2532	ExplicitSpecifier> {
2533	// This class stores some data in DeclContext::CXXConstructorDeclBits
2534	// to save some space. Use the provided accessors to access it.
2535
2536	/// \name Support for base and member initializers.
2537	/// \{
2538	/// The arguments used to initialize the base or member.
2539	LazyCXXCtorInitializersPtr CtorInitializers;
2540
2541	CXXConstructorDecl(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2542	const DeclarationNameInfo &NameInfo, QualType T,
2543	TypeSourceInfo *TInfo, ExplicitSpecifier ES,
2544	bool UsesFPIntrin, bool isInline,
2545	bool isImplicitlyDeclared, ConstexprSpecKind ConstexprKind,
2546	InheritedConstructor Inherited,
2547	Expr *TrailingRequiresClause);
2548
2549	void anchor() override;
2550
2551	size_t numTrailingObjects(OverloadToken<InheritedConstructor>) const {
2552	return CXXConstructorDeclBits.IsInheritingConstructor;
2553	}
2554	size_t numTrailingObjects(OverloadToken<ExplicitSpecifier>) const {
2555	return CXXConstructorDeclBits.HasTrailingExplicitSpecifier;
2556	}
2557
2558	ExplicitSpecifier getExplicitSpecifierInternal() const {
2559	if (CXXConstructorDeclBits.HasTrailingExplicitSpecifier)
2560	return *getTrailingObjects<ExplicitSpecifier>();
2561	return ExplicitSpecifier (
2562	nullptr, CXXConstructorDeclBits.IsSimpleExplicit
2563	? ExplicitSpecKind::ResolvedTrue
2564	: ExplicitSpecKind::ResolvedFalse);
2565	}
2566
2567	enum TrailingAllocKind {
2568	TAKInheritsConstructor = `1`,
2569	TAKHasTailExplicit = `1` << `1`,
2570	};
2571
2572	uint64_t getTrailingAllocKind() const {
2573	return numTrailingObjects(OverloadToken<InheritedConstructor>()) \|
2574	(numTrailingObjects(OverloadToken<ExplicitSpecifier>()) << `1`);
2575	}
2576
2577	public:
2578	friend class ASTDeclReader;
2579	friend class ASTDeclWriter;
2580	friend TrailingObjects;
2581
2582	static CXXConstructorDecl *CreateDeserialized(ASTContext &C, DeclID ID,
2583	uint64_t AllocKind);
2584	static CXXConstructorDecl *
2585	Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2586	const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2587	ExplicitSpecifier ES, bool UsesFPIntrin, bool isInline,
2588	bool isImplicitlyDeclared, ConstexprSpecKind ConstexprKind,
2589	InheritedConstructor Inherited = InheritedConstructor (),
2590	Expr TrailingRequiresClause = nullptr*);
2591
2592	void setExplicitSpecifier(ExplicitSpecifier ES) {
2593	assert((!ES.getExpr() \|\|
2594	CXXConstructorDeclBits.HasTrailingExplicitSpecifier) &&
2595	"cannot set this explicit specifier. no trail-allocated space for "
2596	"explicit");
2597	if (ES.getExpr())
2598	*getCanonicalDecl()->getTrailingObjects<ExplicitSpecifier>() = ES;
2599	else
2600	CXXConstructorDeclBits.IsSimpleExplicit = ES.isExplicit();
2601	}
2602
2603	ExplicitSpecifier getExplicitSpecifier() {
2604	return getCanonicalDecl()->getExplicitSpecifierInternal();
2605	}
2606	const ExplicitSpecifier getExplicitSpecifier() const {
2607	return getCanonicalDecl()->getExplicitSpecifierInternal();
2608	}
2609
2610	/// Return true if the declaration is already resolved to be explicit.
2611	bool isExplicit() const { return getExplicitSpecifier().isExplicit(); }
2612
2613	/// Iterates through the member/base initializer list.
2614	using init_iterator = CXXCtorInitializer **;
2615
2616	/// Iterates through the member/base initializer list.
2617	using init_const_iterator = CXXCtorInitializer *const *;
2618
2619	using init_range = llvm::iterator_range<init_iterator>;
2620	using init_const_range = llvm::iterator_range<init_const_iterator>;
2621
2622	init_range inits() { return init_range (init_begin(), init_end()); }
2623	init_const_range inits() const {
2624	return init_const_range (init_begin(), init_end());
2625	}
2626
2627	/// Retrieve an iterator to the first initializer.
2628	init_iterator init_begin() {
2629	const auto ConstThis = this*;
2630	return const_cast<init_iterator>(ConstThis->init_begin());
2631	}
2632
2633	/// Retrieve an iterator to the first initializer.
2634	init_const_iterator init_begin() const;
2635
2636	/// Retrieve an iterator past the last initializer.
2637	init_iterator init_end() {
2638	return init_begin() + getNumCtorInitializers();
2639	}
2640
2641	/// Retrieve an iterator past the last initializer.
2642	init_const_iterator init_end() const {
2643	return init_begin() + getNumCtorInitializers();
2644	}
2645
2646	using init_reverse_iterator = std::reverse_iterator<init_iterator>;
2647	using init_const_reverse_iterator =
2648	std::reverse_iterator<init_const_iterator>;
2649
2650	init_reverse_iterator init_rbegin() {
2651	return init_reverse_iterator (init_end());
2652	}
2653	init_const_reverse_iterator init_rbegin() const {
2654	return init_const_reverse_iterator (init_end());
2655	}
2656
2657	init_reverse_iterator init_rend() {
2658	return init_reverse_iterator (init_begin());
2659	}
2660	init_const_reverse_iterator init_rend() const {
2661	return init_const_reverse_iterator (init_begin());
2662	}
2663
2664	/// Determine the number of arguments used to initialize the member
2665	/// or base.
2666	unsigned getNumCtorInitializers() const {
2667	return CXXConstructorDeclBits.NumCtorInitializers;
2668	}
2669
2670	void setNumCtorInitializers(unsigned numCtorInitializers) {
2671	CXXConstructorDeclBits.NumCtorInitializers = numCtorInitializers;
2672	// This assert added because NumCtorInitializers is stored
2673	// in CXXConstructorDeclBits as a bitfield and its width has
2674	// been shrunk from 32 bits to fit into CXXConstructorDeclBitfields.
2675	assert(CXXConstructorDeclBits.NumCtorInitializers ==
2676	numCtorInitializers && "NumCtorInitializers overflow!");
2677	}
2678
2679	void setCtorInitializers(CXXCtorInitializer **Initializers) {
2680	CtorInitializers = Initializers;
2681	}
2682
2683	/// Determine whether this constructor is a delegating constructor.
2684	bool isDelegatingConstructor() const {
2685	return (getNumCtorInitializers() == `1`) &&
2686	init_begin()[`0`]->isDelegatingInitializer();
2687	}
2688
2689	/// When this constructor delegates to another, retrieve the target.
2690	CXXConstructorDecl getTargetConstructor() const*;
2691
2692	/// Whether this constructor is a default
2693	/// constructor (C++ [class.ctor]p5), which can be used to
2694	/// default-initialize a class of this type.
2695	bool isDefaultConstructor() const;
2696
2697	/// Whether this constructor is a copy constructor (C++ [class.copy]p2,
2698	/// which can be used to copy the class.
2699	///
2700	/// \p TypeQuals will be set to the qualifiers on the
2701	/// argument type. For example, \p TypeQuals would be set to \c
2702	/// Qualifiers::Const for the following copy constructor:
2703	///
2704	/// \code
2705	/// class X {
2706	/// public:
2707	/// X(const X&);
2708	/// };
2709	/// \endcode
2710	bool isCopyConstructor(unsigned &TypeQuals) const;
2711
2712	/// Whether this constructor is a copy
2713	/// constructor (C++ [class.copy]p2, which can be used to copy the
2714	/// class.
2715	bool isCopyConstructor() const {
2716	unsigned TypeQuals = `0`;
2717	return isCopyConstructor(TypeQuals);
2718	}
2719
2720	/// Determine whether this constructor is a move constructor
2721	/// (C++11 [class.copy]p3), which can be used to move values of the class.
2722	///
2723	/// \param TypeQuals If this constructor is a move constructor, will be set
2724	/// to the type qualifiers on the referent of the first parameter's type.
2725	bool isMoveConstructor(unsigned &TypeQuals) const;
2726
2727	/// Determine whether this constructor is a move constructor
2728	/// (C++11 [class.copy]p3), which can be used to move values of the class.
2729	bool isMoveConstructor() const {
2730	unsigned TypeQuals = `0`;
2731	return isMoveConstructor(TypeQuals);
2732	}
2733
2734	/// Determine whether this is a copy or move constructor.
2735	///
2736	/// \param TypeQuals Will be set to the type qualifiers on the reference
2737	/// parameter, if in fact this is a copy or move constructor.
2738	bool isCopyOrMoveConstructor(unsigned &TypeQuals) const;
2739
2740	/// Determine whether this a copy or move constructor.
2741	bool isCopyOrMoveConstructor() const {
2742	unsigned Quals;
2743	return isCopyOrMoveConstructor(TypeQuals&: Quals);
2744	}
2745
2746	/// Whether this constructor is a
2747	/// converting constructor (C++ [class.conv.ctor]), which can be
2748	/// used for user-defined conversions.
2749	bool isConvertingConstructor(bool AllowExplicit) const;
2750
2751	/// Determine whether this is a member template specialization that
2752	/// would copy the object to itself. Such constructors are never used to copy
2753	/// an object.
2754	bool isSpecializationCopyingObject() const;
2755
2756	/// Determine whether this is an implicit constructor synthesized to
2757	/// model a call to a constructor inherited from a base class.
2758	bool isInheritingConstructor() const {
2759	return CXXConstructorDeclBits.IsInheritingConstructor;
2760	}
2761
2762	/// State that this is an implicit constructor synthesized to
2763	/// model a call to a constructor inherited from a base class.
2764	void setInheritingConstructor(bool isIC = true) {
2765	CXXConstructorDeclBits.IsInheritingConstructor = isIC;
2766	}
2767
2768	/// Get the constructor that this inheriting constructor is based on.
2769	InheritedConstructor getInheritedConstructor() const {
2770	return isInheritingConstructor() ?
2771	*getTrailingObjects<InheritedConstructor>() : InheritedConstructor ();
2772	}
2773
2774	CXXConstructorDecl *getCanonicalDecl() override {
2775	return cast<CXXConstructorDecl>(FunctionDecl::getCanonicalDecl());
2776	}
2777	const CXXConstructorDecl getCanonicalDecl() const* {
2778	return const_cast<CXXConstructorDecl>(this*)->getCanonicalDecl();
2779	}
2780
2781	// Implement isa/cast/dyncast/etc.
2782	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
2783	static bool classofKind(Kind K) { return K == CXXConstructor; }
2784	};
2785
2786	/// Represents a C++ destructor within a class.
2787	///
2788	/// For example:
2789	///
2790	/// \code
2791	/// class X {
2792	/// public:
2793	/// ~X(); // represented by a CXXDestructorDecl.
2794	/// };
2795	/// \endcode
2796	class CXXDestructorDecl : public CXXMethodDecl {
2797	friend class ASTDeclReader;
2798	friend class ASTDeclWriter;
2799
2800	// FIXME: Don't allocate storage for these except in the first declaration
2801	// of a virtual destructor.
2802	FunctionDecl OperatorDelete = nullptr*;
2803	Expr OperatorDeleteThisArg = nullptr*;
2804
2805	CXXDestructorDecl(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2806	const DeclarationNameInfo &NameInfo, QualType T,
2807	TypeSourceInfo TInfo, bool* UsesFPIntrin, bool isInline,
2808	bool isImplicitlyDeclared, ConstexprSpecKind ConstexprKind,
2809	Expr TrailingRequiresClause = nullptr*)
2810	: CXXMethodDecl(CXXDestructor, C, RD, StartLoc, NameInfo, T, TInfo,
2811	SC_None, UsesFPIntrin, isInline, ConstexprKind,
2812	SourceLocation(), TrailingRequiresClause) {
2813	setImplicit(isImplicitlyDeclared);
2814	}
2815
2816	void anchor() override;
2817
2818	public:
2819	static CXXDestructorDecl *
2820	Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2821	const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2822	bool UsesFPIntrin, bool isInline, bool isImplicitlyDeclared,
2823	ConstexprSpecKind ConstexprKind,
2824	Expr TrailingRequiresClause = nullptr*);
2825	static CXXDestructorDecl *CreateDeserialized(ASTContext & C, DeclID ID);
2826
2827	void setOperatorDelete(FunctionDecl OD, Expr ThisArg);
2828
2829	const FunctionDecl getOperatorDelete() const* {
2830	return getCanonicalDecl()->OperatorDelete;
2831	}
2832
2833	Expr getOperatorDeleteThisArg() const* {
2834	return getCanonicalDecl()->OperatorDeleteThisArg;
2835	}
2836
2837	CXXDestructorDecl *getCanonicalDecl() override {
2838	return cast<CXXDestructorDecl>(FunctionDecl::getCanonicalDecl());
2839	}
2840	const CXXDestructorDecl getCanonicalDecl() const* {
2841	return const_cast<CXXDestructorDecl>(this*)->getCanonicalDecl();
2842	}
2843
2844	// Implement isa/cast/dyncast/etc.
2845	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
2846	static bool classofKind(Kind K) { return K == CXXDestructor; }
2847	};
2848
2849	/// Represents a C++ conversion function within a class.
2850	///
2851	/// For example:
2852	///
2853	/// \code
2854	/// class X {
2855	/// public:
2856	/// operator bool();
2857	/// };
2858	/// \endcode
2859	class CXXConversionDecl : public CXXMethodDecl {
2860	CXXConversionDecl(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2861	const DeclarationNameInfo &NameInfo, QualType T,
2862	TypeSourceInfo TInfo, bool* UsesFPIntrin, bool isInline,
2863	ExplicitSpecifier ES, ConstexprSpecKind ConstexprKind,
2864	SourceLocation EndLocation,
2865	Expr TrailingRequiresClause = nullptr*)
2866	: CXXMethodDecl(CXXConversion, C, RD, StartLoc, NameInfo, T, TInfo,
2867	SC_None, UsesFPIntrin, isInline, ConstexprKind,
2868	EndLocation, TrailingRequiresClause),
2869	ExplicitSpec (ES) {}
2870	void anchor() override;
2871
2872	ExplicitSpecifier ExplicitSpec;
2873
2874	public:
2875	friend class ASTDeclReader;
2876	friend class ASTDeclWriter;
2877
2878	static CXXConversionDecl *
2879	Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2880	const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2881	bool UsesFPIntrin, bool isInline, ExplicitSpecifier ES,
2882	ConstexprSpecKind ConstexprKind, SourceLocation EndLocation,
2883	Expr TrailingRequiresClause = nullptr*);
2884	static CXXConversionDecl *CreateDeserialized(ASTContext &C, DeclID ID);
2885
2886	ExplicitSpecifier getExplicitSpecifier() {
2887	return getCanonicalDecl()->ExplicitSpec;
2888	}
2889
2890	const ExplicitSpecifier getExplicitSpecifier() const {
2891	return getCanonicalDecl()->ExplicitSpec;
2892	}
2893
2894	/// Return true if the declaration is already resolved to be explicit.
2895	bool isExplicit() const { return getExplicitSpecifier().isExplicit(); }
2896	void setExplicitSpecifier(ExplicitSpecifier ES) { ExplicitSpec = ES; }
2897
2898	/// Returns the type that this conversion function is converting to.
2899	QualType getConversionType() const {
2900	return getType()->castAs<FunctionType>()->getReturnType();
2901	}
2902
2903	/// Determine whether this conversion function is a conversion from
2904	/// a lambda closure type to a block pointer.
2905	bool isLambdaToBlockPointerConversion() const;
2906
2907	CXXConversionDecl *getCanonicalDecl() override {
2908	return cast<CXXConversionDecl>(FunctionDecl::getCanonicalDecl());
2909	}
2910	const CXXConversionDecl getCanonicalDecl() const* {
2911	return const_cast<CXXConversionDecl>(this*)->getCanonicalDecl();
2912	}
2913
2914	// Implement isa/cast/dyncast/etc.
2915	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
2916	static bool classofKind(Kind K) { return K == CXXConversion; }
2917	};
2918
2919	/// Represents the language in a linkage specification.
2920	///
2921	/// The values are part of the serialization ABI for
2922	/// ASTs and cannot be changed without altering that ABI.
2923	enum class LinkageSpecLanguageIDs { C = `1`, CXX = `2` };
2924
2925	/// Represents a linkage specification.
2926	///
2927	/// For example:
2928	/// \code
2929	/// extern "C" void foo();
2930	/// \endcode
2931	class LinkageSpecDecl : public Decl, public DeclContext {
2932	virtual void anchor();
2933	// This class stores some data in DeclContext::LinkageSpecDeclBits to save
2934	// some space. Use the provided accessors to access it.
2935
2936	/// The source location for the extern keyword.
2937	SourceLocation ExternLoc;
2938
2939	/// The source location for the right brace (if valid).
2940	SourceLocation RBraceLoc;
2941
2942	LinkageSpecDecl(DeclContext *DC, SourceLocation ExternLoc,
2943	SourceLocation LangLoc, LinkageSpecLanguageIDs lang,
2944	bool HasBraces);
2945
2946	public:
2947	static LinkageSpecDecl Create(ASTContext &C, DeclContext DC,
2948	SourceLocation ExternLoc,
2949	SourceLocation LangLoc,
2950	LinkageSpecLanguageIDs Lang, bool HasBraces);
2951	static LinkageSpecDecl *CreateDeserialized(ASTContext &C, DeclID ID);
2952
2953	/// Return the language specified by this linkage specification.
2954	LinkageSpecLanguageIDs getLanguage() const {
2955	return static_cast<LinkageSpecLanguageIDs>(LinkageSpecDeclBits.Language);
2956	}
2957
2958	/// Set the language specified by this linkage specification.
2959	void setLanguage(LinkageSpecLanguageIDs L) {
2960	LinkageSpecDeclBits.Language = llvm::to_underlying(E: L);
2961	}
2962
2963	/// Determines whether this linkage specification had braces in
2964	/// its syntactic form.
2965	bool hasBraces() const {
2966	assert(!RBraceLoc.isValid() \|\| LinkageSpecDeclBits.HasBraces);
2967	return LinkageSpecDeclBits.HasBraces;
2968	}
2969
2970	SourceLocation getExternLoc() const { return ExternLoc; }
2971	SourceLocation getRBraceLoc() const { return RBraceLoc; }
2972	void setExternLoc(SourceLocation L) { ExternLoc = L; }
2973	void setRBraceLoc(SourceLocation L) {
2974	RBraceLoc = L;
2975	LinkageSpecDeclBits.HasBraces = RBraceLoc.isValid();
2976	}
2977
2978	SourceLocation getEndLoc() const LLVM_READONLY {
2979	if (hasBraces())
2980	return getRBraceLoc();
2981	// No braces: get the end location of the (only) declaration in context
2982	// (if present).
2983	return decls_empty() ? getLocation() : decls_begin()->getEndLoc();
2984	}
2985
2986	SourceRange getSourceRange() const override LLVM_READONLY {
2987	return SourceRange (ExternLoc, getEndLoc());
2988	}
2989
2990	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
2991	static bool classofKind(Kind K) { return K == LinkageSpec; }
2992
2993	static DeclContext castToDeclContext(const* LinkageSpecDecl *D) {
2994	return static_cast<DeclContext >(const_cast<LinkageSpecDecl>(D));
2995	}
2996
2997	static LinkageSpecDecl castFromDeclContext(const* DeclContext *DC) {
2998	return static_cast<LinkageSpecDecl >(const_cast<DeclContext>(DC));
2999	}
3000	};
3001
3002	/// Represents C++ using-directive.
3003	///
3004	/// For example:
3005	/// \code
3006	/// using namespace std;
3007	/// \endcode
3008	///
3009	/// \note UsingDirectiveDecl should be Decl not NamedDecl, but we provide
3010	/// artificial names for all using-directives in order to store
3011	/// them in DeclContext effectively.
3012	class UsingDirectiveDecl : public NamedDecl {
3013	/// The location of the \c using keyword.
3014	SourceLocation UsingLoc;
3015
3016	/// The location of the \c namespace keyword.
3017	SourceLocation NamespaceLoc;
3018
3019	/// The nested-name-specifier that precedes the namespace.
3020	NestedNameSpecifierLoc QualifierLoc;
3021
3022	/// The namespace nominated by this using-directive.
3023	NamedDecl *NominatedNamespace;
3024
3025	/// Enclosing context containing both using-directive and nominated
3026	/// namespace.
3027	DeclContext *CommonAncestor;
3028
3029	UsingDirectiveDecl(DeclContext *DC, SourceLocation UsingLoc,
3030	SourceLocation NamespcLoc,
3031	NestedNameSpecifierLoc QualifierLoc,
3032	SourceLocation IdentLoc,
3033	NamedDecl *Nominated,
3034	DeclContext *CommonAncestor)
3035	: NamedDecl(UsingDirective, DC, IdentLoc, getName()), UsingLoc (UsingLoc),
3036	NamespaceLoc (NamespcLoc), QualifierLoc (QualifierLoc),
3037	NominatedNamespace(Nominated), CommonAncestor(CommonAncestor) {}
3038
3039	/// Returns special DeclarationName used by using-directives.
3040	///
3041	/// This is only used by DeclContext for storing UsingDirectiveDecls in
3042	/// its lookup structure.
3043	static DeclarationName getName() {
3044	return DeclarationName::getUsingDirectiveName();
3045	}
3046
3047	void anchor() override;
3048
3049	public:
3050	friend class ASTDeclReader;
3051
3052	// Friend for getUsingDirectiveName.
3053	friend class DeclContext;
3054
3055	/// Retrieve the nested-name-specifier that qualifies the
3056	/// name of the namespace, with source-location information.
3057	NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
3058
3059	/// Retrieve the nested-name-specifier that qualifies the
3060	/// name of the namespace.
3061	NestedNameSpecifier getQualifier() const* {
3062	return QualifierLoc.getNestedNameSpecifier();
3063	}
3064
3065	NamedDecl getNominatedNamespaceAsWritten() { return* NominatedNamespace; }
3066	const NamedDecl getNominatedNamespaceAsWritten() const* {
3067	return NominatedNamespace;
3068	}
3069
3070	/// Returns the namespace nominated by this using-directive.
3071	NamespaceDecl *getNominatedNamespace();
3072
3073	const NamespaceDecl getNominatedNamespace() const* {
3074	return const_cast<UsingDirectiveDecl>(this*)->getNominatedNamespace();
3075	}
3076
3077	/// Returns the common ancestor context of this using-directive and
3078	/// its nominated namespace.
3079	DeclContext getCommonAncestor() { return* CommonAncestor; }
3080	const DeclContext getCommonAncestor() const* { return CommonAncestor; }
3081
3082	/// Return the location of the \c using keyword.
3083	SourceLocation getUsingLoc() const { return UsingLoc; }
3084
3085	// FIXME: Could omit 'Key' in name.
3086	/// Returns the location of the \c namespace keyword.
3087	SourceLocation getNamespaceKeyLocation() const { return NamespaceLoc; }
3088
3089	/// Returns the location of this using declaration's identifier.
3090	SourceLocation getIdentLocation() const { return getLocation(); }
3091
3092	static UsingDirectiveDecl Create(ASTContext &C, DeclContext DC,
3093	SourceLocation UsingLoc,
3094	SourceLocation NamespaceLoc,
3095	NestedNameSpecifierLoc QualifierLoc,
3096	SourceLocation IdentLoc,
3097	NamedDecl *Nominated,
3098	DeclContext *CommonAncestor);
3099	static UsingDirectiveDecl *CreateDeserialized(ASTContext &C, DeclID ID);
3100
3101	SourceRange getSourceRange() const override LLVM_READONLY {
3102	return SourceRange(UsingLoc, getLocation());
3103	}
3104
3105	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
3106	static bool classofKind(Kind K) { return K == UsingDirective; }
3107	};
3108
3109	/// Represents a C++ namespace alias.
3110	///
3111	/// For example:
3112	///
3113	/// \code
3114	/// namespace Foo = Bar;
3115	/// \endcode
3116	class NamespaceAliasDecl : public NamedDecl,
3117	public Redeclarable<NamespaceAliasDecl> {
3118	friend class ASTDeclReader;
3119
3120	/// The location of the \c namespace keyword.
3121	SourceLocation NamespaceLoc;
3122
3123	/// The location of the namespace's identifier.
3124	///
3125	/// This is accessed by TargetNameLoc.
3126	SourceLocation IdentLoc;
3127
3128	/// The nested-name-specifier that precedes the namespace.
3129	NestedNameSpecifierLoc QualifierLoc;
3130
3131	/// The Decl that this alias points to, either a NamespaceDecl or
3132	/// a NamespaceAliasDecl.
3133	NamedDecl *Namespace;
3134
3135	NamespaceAliasDecl(ASTContext &C, DeclContext *DC,
3136	SourceLocation NamespaceLoc, SourceLocation AliasLoc,
3137	IdentifierInfo *Alias, NestedNameSpecifierLoc QualifierLoc,
3138	SourceLocation IdentLoc, NamedDecl *Namespace)
3139	: NamedDecl(NamespaceAlias, DC, AliasLoc, Alias), redeclarable_base (C),
3140	NamespaceLoc (NamespaceLoc), IdentLoc (IdentLoc),
3141	QualifierLoc (QualifierLoc), Namespace(Namespace) {}
3142
3143	void anchor() override;
3144
3145	using redeclarable_base = Redeclarable<NamespaceAliasDecl>;
3146
3147	NamespaceAliasDecl *getNextRedeclarationImpl() override;
3148	NamespaceAliasDecl *getPreviousDeclImpl() override;
3149	NamespaceAliasDecl *getMostRecentDeclImpl() override;
3150
3151	public:
3152	static NamespaceAliasDecl Create(ASTContext &C, DeclContext DC,
3153	SourceLocation NamespaceLoc,
3154	SourceLocation AliasLoc,
3155	IdentifierInfo *Alias,
3156	NestedNameSpecifierLoc QualifierLoc,
3157	SourceLocation IdentLoc,
3158	NamedDecl *Namespace);
3159
3160	static NamespaceAliasDecl *CreateDeserialized(ASTContext &C, DeclID ID);
3161
3162	using redecl_range = redeclarable_base::redecl_range;
3163	using redecl_iterator = redeclarable_base::redecl_iterator;
3164
3165	using redeclarable_base::redecls_begin;
3166	using redeclarable_base::redecls_end;
3167	using redeclarable_base::redecls;
3168	using redeclarable_base::getPreviousDecl;
3169	using redeclarable_base::getMostRecentDecl;
3170
3171	NamespaceAliasDecl *getCanonicalDecl() override {
3172	return getFirstDecl();
3173	}
3174	const NamespaceAliasDecl getCanonicalDecl() const* {
3175	return getFirstDecl();
3176	}
3177
3178	/// Retrieve the nested-name-specifier that qualifies the
3179	/// name of the namespace, with source-location information.
3180	NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
3181
3182	/// Retrieve the nested-name-specifier that qualifies the
3183	/// name of the namespace.
3184	NestedNameSpecifier getQualifier() const* {
3185	return QualifierLoc.getNestedNameSpecifier();
3186	}
3187
3188	/// Retrieve the namespace declaration aliased by this directive.
3189	NamespaceDecl *getNamespace() {
3190	if (auto *AD = dyn_cast<NamespaceAliasDecl>(Val: Namespace))
3191	return AD->getNamespace();
3192
3193	return cast<NamespaceDecl>(Val: Namespace);
3194	}
3195
3196	const NamespaceDecl getNamespace() const* {
3197	return const_cast<NamespaceAliasDecl >(this*)->getNamespace();
3198	}
3199
3200	/// Returns the location of the alias name, i.e. 'foo' in
3201	/// "namespace foo = ns::bar;".
3202	SourceLocation getAliasLoc() const { return getLocation(); }
3203
3204	/// Returns the location of the \c namespace keyword.
3205	SourceLocation getNamespaceLoc() const { return NamespaceLoc; }
3206
3207	/// Returns the location of the identifier in the named namespace.
3208	SourceLocation getTargetNameLoc() const { return IdentLoc; }
3209
3210	/// Retrieve the namespace that this alias refers to, which
3211	/// may either be a NamespaceDecl or a NamespaceAliasDecl.
3212	NamedDecl getAliasedNamespace() const* { return Namespace; }
3213
3214	SourceRange getSourceRange() const override LLVM_READONLY {
3215	return SourceRange (NamespaceLoc, IdentLoc);
3216	}
3217
3218	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
3219	static bool classofKind(Kind K) { return K == NamespaceAlias; }
3220	};
3221
3222	/// Implicit declaration of a temporary that was materialized by
3223	/// a MaterializeTemporaryExpr and lifetime-extended by a declaration
3224	class LifetimeExtendedTemporaryDecl final
3225	: public Decl,
3226	public Mergeable<LifetimeExtendedTemporaryDecl> {
3227	friend class MaterializeTemporaryExpr;
3228	friend class ASTDeclReader;
3229
3230	Stmt ExprWithTemporary = nullptr*;
3231
3232	/// The declaration which lifetime-extended this reference, if any.
3233	/// Either a VarDecl, or (for a ctor-initializer) a FieldDecl.
3234	ValueDecl ExtendingDecl = nullptr*;
3235	unsigned ManglingNumber;
3236
3237	mutable APValue Value = nullptr*;
3238
3239	virtual void anchor();
3240
3241	LifetimeExtendedTemporaryDecl(Expr Temp, ValueDecl EDecl, unsigned Mangling)
3242	: Decl(Decl::LifetimeExtendedTemporary, EDecl->getDeclContext(),
3243	EDecl->getLocation()),
3244	ExprWithTemporary(Temp), ExtendingDecl(EDecl),
3245	ManglingNumber(Mangling) {}
3246
3247	LifetimeExtendedTemporaryDecl(EmptyShell)
3248	: Decl(Decl::LifetimeExtendedTemporary, EmptyShell{}) {}
3249
3250	public:
3251	static LifetimeExtendedTemporaryDecl Create(Expr Temp, ValueDecl *EDec,
3252	unsigned Mangling) {
3253	return new (EDec->getASTContext(), EDec->getDeclContext())
3254	LifetimeExtendedTemporaryDecl (Temp, EDec, Mangling);
3255	}
3256	static LifetimeExtendedTemporaryDecl *CreateDeserialized(ASTContext &C,
3257	DeclID ID) {
3258	return new (C, ID) LifetimeExtendedTemporaryDecl (EmptyShell{});
3259	}
3260
3261	ValueDecl getExtendingDecl() { return* ExtendingDecl; }
3262	const ValueDecl getExtendingDecl() const* { return ExtendingDecl; }
3263
3264	/// Retrieve the storage duration for the materialized temporary.
3265	StorageDuration getStorageDuration() const;
3266
3267	/// Retrieve the expression to which the temporary materialization conversion
3268	/// was applied. This isn't necessarily the initializer of the temporary due
3269	/// to the C++98 delayed materialization rules, but
3270	/// skipRValueSubobjectAdjustments can be used to find said initializer within
3271	/// the subexpression.
3272	Expr getTemporaryExpr() { return* cast<Expr>(Val: ExprWithTemporary); }
3273	const Expr getTemporaryExpr() const* { return cast<Expr>(Val: ExprWithTemporary); }
3274
3275	unsigned getManglingNumber() const { return ManglingNumber; }
3276
3277	/// Get the storage for the constant value of a materialized temporary
3278	/// of static storage duration.
3279	APValue getOrCreateValue(bool* MayCreate) const;
3280
3281	APValue getValue() const* { return Value; }
3282
3283	// Iterators
3284	Stmt::child_range childrenExpr() {
3285	return Stmt::child_range (&ExprWithTemporary, &ExprWithTemporary + `1`);
3286	}
3287
3288	Stmt::const_child_range childrenExpr() const {
3289	return Stmt::const_child_range (&ExprWithTemporary, &ExprWithTemporary + `1`);
3290	}
3291
3292	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
3293	static bool classofKind(Kind K) {
3294	return K == Decl::LifetimeExtendedTemporary;
3295	}
3296	};
3297
3298	/// Represents a shadow declaration implicitly introduced into a scope by a
3299	/// (resolved) using-declaration or using-enum-declaration to achieve
3300	/// the desired lookup semantics.
3301	///
3302	/// For example:
3303	/// \code
3304	/// namespace A {
3305	/// void foo();
3306	/// void foo(int);
3307	/// struct foo {};
3308	/// enum bar { bar1, bar2 };
3309	/// }
3310	/// namespace B {
3311	/// // add a UsingDecl and three UsingShadowDecls (named foo) to B.
3312	/// using A::foo;
3313	/// // adds UsingEnumDecl and two UsingShadowDecls (named bar1 and bar2) to B.
3314	/// using enum A::bar;
3315	/// }
3316	/// \endcode
3317	class UsingShadowDecl : public NamedDecl, public Redeclarable<UsingShadowDecl> {
3318	friend class BaseUsingDecl;
3319
3320	/// The referenced declaration.
3321	NamedDecl Underlying = nullptr*;
3322
3323	/// The using declaration which introduced this decl or the next using
3324	/// shadow declaration contained in the aforementioned using declaration.
3325	NamedDecl UsingOrNextShadow = nullptr*;
3326
3327	void anchor() override;
3328
3329	using redeclarable_base = Redeclarable<UsingShadowDecl>;
3330
3331	UsingShadowDecl *getNextRedeclarationImpl() override {
3332	return getNextRedeclaration();
3333	}
3334
3335	UsingShadowDecl *getPreviousDeclImpl() override {
3336	return getPreviousDecl();
3337	}
3338
3339	UsingShadowDecl *getMostRecentDeclImpl() override {
3340	return getMostRecentDecl();
3341	}
3342
3343	protected:
3344	UsingShadowDecl(Kind K, ASTContext &C, DeclContext *DC, SourceLocation Loc,
3345	DeclarationName Name, BaseUsingDecl *Introducer,
3346	NamedDecl *Target);
3347	UsingShadowDecl(Kind K, ASTContext &C, EmptyShell);
3348
3349	public:
3350	friend class ASTDeclReader;
3351	friend class ASTDeclWriter;
3352
3353	static UsingShadowDecl Create(ASTContext &C, DeclContext DC,
3354	SourceLocation Loc, DeclarationName Name,
3355	BaseUsingDecl Introducer, NamedDecl Target) {
3356	return new (C, DC)
3357	UsingShadowDecl(UsingShadow, C, DC, Loc, Name, Introducer, Target);
3358	}
3359
3360	static UsingShadowDecl *CreateDeserialized(ASTContext &C, DeclID ID);
3361
3362	using redecl_range = redeclarable_base::redecl_range;
3363	using redecl_iterator = redeclarable_base::redecl_iterator;
3364
3365	using redeclarable_base::redecls_begin;
3366	using redeclarable_base::redecls_end;
3367	using redeclarable_base::redecls;
3368	using redeclarable_base::getPreviousDecl;
3369	using redeclarable_base::getMostRecentDecl;
3370	using redeclarable_base::isFirstDecl;
3371
3372	UsingShadowDecl *getCanonicalDecl() override {
3373	return getFirstDecl();
3374	}
3375	const UsingShadowDecl getCanonicalDecl() const* {
3376	return getFirstDecl();
3377	}
3378
3379	/// Gets the underlying declaration which has been brought into the
3380	/// local scope.
3381	NamedDecl getTargetDecl() const* { return Underlying; }
3382
3383	/// Sets the underlying declaration which has been brought into the
3384	/// local scope.
3385	void setTargetDecl(NamedDecl *ND) {
3386	assert(ND && "Target decl is null!");
3387	Underlying = ND;
3388	// A UsingShadowDecl is never a friend or local extern declaration, even
3389	// if it is a shadow declaration for one.
3390	IdentifierNamespace =
3391	ND->getIdentifierNamespace() &
3392	~(IDNS_OrdinaryFriend \| IDNS_TagFriend \| IDNS_LocalExtern);
3393	}
3394
3395	/// Gets the (written or instantiated) using declaration that introduced this
3396	/// declaration.
3397	BaseUsingDecl getIntroducer() const*;
3398
3399	/// The next using shadow declaration contained in the shadow decl
3400	/// chain of the using declaration which introduced this decl.
3401	UsingShadowDecl getNextUsingShadowDecl() const* {
3402	return dyn_cast_or_null<UsingShadowDecl>(Val: UsingOrNextShadow);
3403	}
3404
3405	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
3406	static bool classofKind(Kind K) {
3407	return K == Decl::UsingShadow \|\| K == Decl::ConstructorUsingShadow;
3408	}
3409	};
3410
3411	/// Represents a C++ declaration that introduces decls from somewhere else. It
3412	/// provides a set of the shadow decls so introduced.
3413
3414	class BaseUsingDecl : public NamedDecl {
3415	/// The first shadow declaration of the shadow decl chain associated
3416	/// with this using declaration.
3417	///
3418	/// The bool member of the pair is a bool flag a derived type may use
3419	/// (UsingDecl makes use of it).
3420	llvm::PointerIntPair<UsingShadowDecl , `1`, bool*> FirstUsingShadow;
3421
3422	protected:
3423	BaseUsingDecl(Kind DK, DeclContext *DC, SourceLocation L, DeclarationName N)
3424	: NamedDecl (DK, DC, L, N), FirstUsingShadow (nullptr, false) {}
3425
3426	private:
3427	void anchor() override;
3428
3429	protected:
3430	/// A bool flag for use by a derived type
3431	bool getShadowFlag() const { return FirstUsingShadow.getInt(); }
3432
3433	/// A bool flag a derived type may set
3434	void setShadowFlag(bool V) { FirstUsingShadow.setInt(V); }
3435
3436	public:
3437	friend class ASTDeclReader;
3438	friend class ASTDeclWriter;
3439
3440	/// Iterates through the using shadow declarations associated with
3441	/// this using declaration.
3442	class shadow_iterator {
3443	/// The current using shadow declaration.
3444	UsingShadowDecl Current = nullptr*;
3445
3446	public:
3447	using value_type = UsingShadowDecl *;
3448	using reference = UsingShadowDecl *;
3449	using pointer = UsingShadowDecl *;
3450	using iterator_category = std::forward_iterator_tag;
3451	using difference_type = std::ptrdiff_t;
3452
3453	shadow_iterator() = default;
3454	explicit shadow_iterator(UsingShadowDecl *C) : Current(C) {}
3455
3456	reference operator() const* { return Current; }
3457	pointer operator->() const { return Current; }
3458
3459	shadow_iterator &operator++() {
3460	Current = Current->getNextUsingShadowDecl();
3461	return *this;
3462	}
3463
3464	shadow_iterator operator++(int) {
3465	shadow_iterator tmp(*this);
3466	++(*this);
3467	return tmp;
3468	}
3469
3470	friend bool operator==(shadow_iterator x, shadow_iterator y) {
3471	return x.Current == y.Current;
3472	}
3473	friend bool operator!=(shadow_iterator x, shadow_iterator y) {
3474	return x.Current != y.Current;
3475	}
3476	};
3477
3478	using shadow_range = llvm::iterator_range<shadow_iterator>;
3479
3480	shadow_range shadows() const {
3481	return shadow_range (shadow_begin(), shadow_end());
3482	}
3483
3484	shadow_iterator shadow_begin() const {
3485	return shadow_iterator (FirstUsingShadow.getPointer());
3486	}
3487
3488	shadow_iterator shadow_end() const { return shadow_iterator (); }
3489
3490	/// Return the number of shadowed declarations associated with this
3491	/// using declaration.
3492	unsigned shadow_size() const {
3493	return std::distance(first: shadow_begin(), last: shadow_end());
3494	}
3495
3496	void addShadowDecl(UsingShadowDecl *S);
3497	void removeShadowDecl(UsingShadowDecl *S);
3498
3499	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
3500	static bool classofKind(Kind K) { return K == Using \|\| K == UsingEnum; }
3501	};
3502
3503	/// Represents a C++ using-declaration.
3504	///
3505	/// For example:
3506	/// \code
3507	/// using someNameSpace::someIdentifier;
3508	/// \endcode
3509	class UsingDecl : public BaseUsingDecl, public Mergeable<UsingDecl> {
3510	/// The source location of the 'using' keyword itself.
3511	SourceLocation UsingLocation;
3512
3513	/// The nested-name-specifier that precedes the name.
3514	NestedNameSpecifierLoc QualifierLoc;
3515
3516	/// Provides source/type location info for the declaration name
3517	/// embedded in the ValueDecl base class.
3518	DeclarationNameLoc DNLoc;
3519
3520	UsingDecl(DeclContext *DC, SourceLocation UL,
3521	NestedNameSpecifierLoc QualifierLoc,
3522	const DeclarationNameInfo &NameInfo, bool HasTypenameKeyword)
3523	: BaseUsingDecl(Using, DC, NameInfo.getLoc(), NameInfo.getName()),
3524	UsingLocation (UL), QualifierLoc (QualifierLoc),
3525	DNLoc (NameInfo.getInfo()) {
3526	setShadowFlag(HasTypenameKeyword);
3527	}
3528
3529	void anchor() override;
3530
3531	public:
3532	friend class ASTDeclReader;
3533	friend class ASTDeclWriter;
3534
3535	/// Return the source location of the 'using' keyword.
3536	SourceLocation getUsingLoc() const { return UsingLocation; }
3537
3538	/// Set the source location of the 'using' keyword.
3539	void setUsingLoc(SourceLocation L) { UsingLocation = L; }
3540
3541	/// Retrieve the nested-name-specifier that qualifies the name,
3542	/// with source-location information.
3543	NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
3544
3545	/// Retrieve the nested-name-specifier that qualifies the name.
3546	NestedNameSpecifier getQualifier() const* {
3547	return QualifierLoc.getNestedNameSpecifier();
3548	}
3549
3550	DeclarationNameInfo getNameInfo() const {
3551	return DeclarationNameInfo(getDeclName(), getLocation(), DNLoc);
3552	}
3553
3554	/// Return true if it is a C++03 access declaration (no 'using').
3555	bool isAccessDeclaration() const { return UsingLocation.isInvalid(); }
3556
3557	/// Return true if the using declaration has 'typename'.
3558	bool hasTypename() const { return getShadowFlag(); }
3559
3560	/// Sets whether the using declaration has 'typename'.
3561	void setTypename(bool TN) { setShadowFlag(TN); }
3562
3563	static UsingDecl Create(ASTContext &C, DeclContext DC,
3564	SourceLocation UsingL,
3565	NestedNameSpecifierLoc QualifierLoc,
3566	const DeclarationNameInfo &NameInfo,
3567	bool HasTypenameKeyword);
3568
3569	static UsingDecl *CreateDeserialized(ASTContext &C, DeclID ID);
3570
3571	SourceRange getSourceRange() const override LLVM_READONLY;
3572
3573	/// Retrieves the canonical declaration of this declaration.
3574	UsingDecl *getCanonicalDecl() override {
3575	return cast<UsingDecl>(getFirstDecl());
3576	}
3577	const UsingDecl getCanonicalDecl() const* {
3578	return cast<UsingDecl>(getFirstDecl());
3579	}
3580
3581	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
3582	static bool classofKind(Kind K) { return K == Using; }
3583	};
3584
3585	/// Represents a shadow constructor declaration introduced into a
3586	/// class by a C++11 using-declaration that names a constructor.
3587	///
3588	/// For example:
3589	/// \code
3590	/// struct Base { Base(int); };
3591	/// struct Derived {
3592	/// using Base::Base; // creates a UsingDecl and a ConstructorUsingShadowDecl
3593	/// };
3594	/// \endcode
3595	class ConstructorUsingShadowDecl final : public UsingShadowDecl {
3596	/// If this constructor using declaration inherted the constructor
3597	/// from an indirect base class, this is the ConstructorUsingShadowDecl
3598	/// in the named direct base class from which the declaration was inherited.
3599	ConstructorUsingShadowDecl NominatedBaseClassShadowDecl = nullptr*;
3600
3601	/// If this constructor using declaration inherted the constructor
3602	/// from an indirect base class, this is the ConstructorUsingShadowDecl
3603	/// that will be used to construct the unique direct or virtual base class
3604	/// that receives the constructor arguments.
3605	ConstructorUsingShadowDecl ConstructedBaseClassShadowDecl = nullptr*;
3606
3607	/// \c true if the constructor ultimately named by this using shadow
3608	/// declaration is within a virtual base class subobject of the class that
3609	/// contains this declaration.
3610	LLVM_PREFERRED_TYPE(bool)
3611	unsigned IsVirtual : `1`;
3612
3613	ConstructorUsingShadowDecl(ASTContext &C, DeclContext *DC, SourceLocation Loc,
3614	UsingDecl Using, NamedDecl Target,
3615	bool TargetInVirtualBase)
3616	: UsingShadowDecl(ConstructorUsingShadow, C, DC, Loc,
3617	Using->getDeclName(), Using,
3618	Target->getUnderlyingDecl()),
3619	NominatedBaseClassShadowDecl(
3620	dyn_cast<ConstructorUsingShadowDecl>(Val: Target)),
3621	ConstructedBaseClassShadowDecl(NominatedBaseClassShadowDecl),
3622	IsVirtual(TargetInVirtualBase) {
3623	// If we found a constructor that chains to a constructor for a virtual
3624	// base, we should directly call that virtual base constructor instead.
3625	// FIXME: This logic belongs in Sema.
3626	if (NominatedBaseClassShadowDecl &&
3627	NominatedBaseClassShadowDecl->constructsVirtualBase()) {
3628	ConstructedBaseClassShadowDecl =
3629	NominatedBaseClassShadowDecl->ConstructedBaseClassShadowDecl;
3630	IsVirtual = true;
3631	}
3632	}
3633
3634	ConstructorUsingShadowDecl(ASTContext &C, EmptyShell Empty)
3635	: UsingShadowDecl(ConstructorUsingShadow, C, Empty), IsVirtual(false) {}
3636
3637	void anchor() override;
3638
3639	public:
3640	friend class ASTDeclReader;
3641	friend class ASTDeclWriter;
3642
3643	static ConstructorUsingShadowDecl Create(ASTContext &C, DeclContext DC,
3644	SourceLocation Loc,
3645	UsingDecl Using, NamedDecl Target,
3646	bool IsVirtual);
3647	static ConstructorUsingShadowDecl *CreateDeserialized(ASTContext &C,
3648	DeclID ID);
3649
3650	/// Override the UsingShadowDecl's getIntroducer, returning the UsingDecl that
3651	/// introduced this.
3652	UsingDecl getIntroducer() const* {
3653	return cast<UsingDecl>(UsingShadowDecl::getIntroducer());
3654	}
3655
3656	/// Returns the parent of this using shadow declaration, which
3657	/// is the class in which this is declared.
3658	//@{
3659	const CXXRecordDecl getParent() const* {
3660	return cast<CXXRecordDecl>(getDeclContext());
3661	}
3662	CXXRecordDecl *getParent() {
3663	return cast<CXXRecordDecl>(getDeclContext());
3664	}
3665	//@}
3666
3667	/// Get the inheriting constructor declaration for the direct base
3668	/// class from which this using shadow declaration was inherited, if there is
3669	/// one. This can be different for each redeclaration of the same shadow decl.
3670	ConstructorUsingShadowDecl getNominatedBaseClassShadowDecl() const* {
3671	return NominatedBaseClassShadowDecl;
3672	}
3673
3674	/// Get the inheriting constructor declaration for the base class
3675	/// for which we don't have an explicit initializer, if there is one.
3676	ConstructorUsingShadowDecl getConstructedBaseClassShadowDecl() const* {
3677	return ConstructedBaseClassShadowDecl;
3678	}
3679
3680	/// Get the base class that was named in the using declaration. This
3681	/// can be different for each redeclaration of this same shadow decl.
3682	CXXRecordDecl getNominatedBaseClass() const*;
3683
3684	/// Get the base class whose constructor or constructor shadow
3685	/// declaration is passed the constructor arguments.
3686	CXXRecordDecl getConstructedBaseClass() const* {
3687	return cast<CXXRecordDecl>((ConstructedBaseClassShadowDecl
3688	? ConstructedBaseClassShadowDecl
3689	: getTargetDecl())
3690	->getDeclContext());
3691	}
3692
3693	/// Returns \c true if the constructed base class is a virtual base
3694	/// class subobject of this declaration's class.
3695	bool constructsVirtualBase() const {
3696	return IsVirtual;
3697	}
3698
3699	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
3700	static bool classofKind(Kind K) { return K == ConstructorUsingShadow; }
3701	};
3702
3703	/// Represents a C++ using-enum-declaration.
3704	///
3705	/// For example:
3706	/// \code
3707	/// using enum SomeEnumTag ;
3708	/// \endcode
3709
3710	class UsingEnumDecl : public BaseUsingDecl, public Mergeable<UsingEnumDecl> {
3711	/// The source location of the 'using' keyword itself.
3712	SourceLocation UsingLocation;
3713	/// The source location of the 'enum' keyword.
3714	SourceLocation EnumLocation;
3715	/// 'qual::SomeEnum' as an EnumType, possibly with Elaborated/Typedef sugar.
3716	TypeSourceInfo *EnumType;
3717
3718	UsingEnumDecl(DeclContext *DC, DeclarationName DN, SourceLocation UL,
3719	SourceLocation EL, SourceLocation NL, TypeSourceInfo *EnumType)
3720	: BaseUsingDecl(UsingEnum, DC, NL, DN), UsingLocation (UL), EnumLocation (EL),
3721	EnumType(EnumType){}
3722
3723	void anchor() override;
3724
3725	public:
3726	friend class ASTDeclReader;
3727	friend class ASTDeclWriter;
3728
3729	/// The source location of the 'using' keyword.
3730	SourceLocation getUsingLoc() const { return UsingLocation; }
3731	void setUsingLoc(SourceLocation L) { UsingLocation = L; }
3732
3733	/// The source location of the 'enum' keyword.
3734	SourceLocation getEnumLoc() const { return EnumLocation; }
3735	void setEnumLoc(SourceLocation L) { EnumLocation = L; }
3736	NestedNameSpecifier getQualifier() const* {
3737	return getQualifierLoc().getNestedNameSpecifier();
3738	}
3739	NestedNameSpecifierLoc getQualifierLoc() const {
3740	if (auto ETL = EnumType->getTypeLoc().getAs<ElaboratedTypeLoc>())
3741	return ETL.getQualifierLoc();
3742	return NestedNameSpecifierLoc ();
3743	}
3744	// Returns the "qualifier::Name" part as a TypeLoc.
3745	TypeLoc getEnumTypeLoc() const {
3746	return EnumType->getTypeLoc();
3747	}
3748	TypeSourceInfo getEnumType() const* {
3749	return EnumType;
3750	}
3751	void setEnumType(TypeSourceInfo *TSI) { EnumType = TSI; }
3752
3753	public:
3754	EnumDecl getEnumDecl() const* { return cast<EnumDecl>(Val: EnumType->getType()->getAsTagDecl()); }
3755
3756	static UsingEnumDecl Create(ASTContext &C, DeclContext DC,
3757	SourceLocation UsingL, SourceLocation EnumL,
3758	SourceLocation NameL, TypeSourceInfo *EnumType);
3759
3760	static UsingEnumDecl *CreateDeserialized(ASTContext &C, DeclID ID);
3761
3762	SourceRange getSourceRange() const override LLVM_READONLY;
3763
3764	/// Retrieves the canonical declaration of this declaration.
3765	UsingEnumDecl *getCanonicalDecl() override {
3766	return cast<UsingEnumDecl>(getFirstDecl());
3767	}
3768	const UsingEnumDecl getCanonicalDecl() const* {
3769	return cast<UsingEnumDecl>(getFirstDecl());
3770	}
3771
3772	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
3773	static bool classofKind(Kind K) { return K == UsingEnum; }
3774	};
3775
3776	/// Represents a pack of using declarations that a single
3777	/// using-declarator pack-expanded into.
3778	///
3779	/// \code
3780	/// template<typename ...T> struct X : T... {
3781	/// using T::operator()...;
3782	/// using T::operator T...;
3783	/// };
3784	/// \endcode
3785	///
3786	/// In the second case above, the UsingPackDecl will have the name
3787	/// 'operator T' (which contains an unexpanded pack), but the individual
3788	/// UsingDecls and UsingShadowDecls will have more reasonable names.
3789	class UsingPackDecl final
3790	: public NamedDecl, public Mergeable<UsingPackDecl>,
3791	private llvm::TrailingObjects<UsingPackDecl, NamedDecl *> {
3792	/// The UnresolvedUsingValueDecl or UnresolvedUsingTypenameDecl from
3793	/// which this waas instantiated.
3794	NamedDecl *InstantiatedFrom;
3795
3796	/// The number of using-declarations created by this pack expansion.
3797	unsigned NumExpansions;
3798
3799	UsingPackDecl(DeclContext DC, NamedDecl InstantiatedFrom,
3800	ArrayRef<NamedDecl *> UsingDecls)
3801	: NamedDecl(UsingPack, DC,
3802	InstantiatedFrom ? InstantiatedFrom->getLocation()
3803	: SourceLocation(),
3804	InstantiatedFrom ? InstantiatedFrom->getDeclName()
3805	: DeclarationName()),
3806	InstantiatedFrom(InstantiatedFrom), NumExpansions(UsingDecls.size()) {
3807	std::uninitialized_copy(UsingDecls.begin(), UsingDecls.end(),
3808	getTrailingObjects<NamedDecl *>());
3809	}
3810
3811	void anchor() override;
3812
3813	public:
3814	friend class ASTDeclReader;
3815	friend class ASTDeclWriter;
3816	friend TrailingObjects;
3817
3818	/// Get the using declaration from which this was instantiated. This will
3819	/// always be an UnresolvedUsingValueDecl or an UnresolvedUsingTypenameDecl
3820	/// that is a pack expansion.
3821	NamedDecl getInstantiatedFromUsingDecl() const* { return InstantiatedFrom; }
3822
3823	/// Get the set of using declarations that this pack expanded into. Note that
3824	/// some of these may still be unresolved.
3825	ArrayRef<NamedDecl > expansions() const* {
3826	return llvm::ArrayRef(getTrailingObjects<NamedDecl *>(), NumExpansions);
3827	}
3828
3829	static UsingPackDecl Create(ASTContext &C, DeclContext DC,
3830	NamedDecl *InstantiatedFrom,
3831	ArrayRef<NamedDecl *> UsingDecls);
3832
3833	static UsingPackDecl *CreateDeserialized(ASTContext &C, DeclID ID,
3834	unsigned NumExpansions);
3835
3836	SourceRange getSourceRange() const override LLVM_READONLY {
3837	return InstantiatedFrom->getSourceRange();
3838	}
3839
3840	UsingPackDecl getCanonicalDecl() override { return* getFirstDecl(); }
3841	const UsingPackDecl getCanonicalDecl() const* { return getFirstDecl(); }
3842
3843	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
3844	static bool classofKind(Kind K) { return K == UsingPack; }
3845	};
3846
3847	/// Represents a dependent using declaration which was not marked with
3848	/// \c typename.
3849	///
3850	/// Unlike non-dependent using declarations, these only* bring through*
3851	/// non-types; otherwise they would break two-phase lookup.
3852	///
3853	/// \code
3854	/// template \<class T> class A : public Base<T> {
3855	/// using Base<T>::foo;
3856	/// };
3857	/// \endcode
3858	class UnresolvedUsingValueDecl : public ValueDecl,
3859	public Mergeable<UnresolvedUsingValueDecl> {
3860	/// The source location of the 'using' keyword
3861	SourceLocation UsingLocation;
3862
3863	/// If this is a pack expansion, the location of the '...'.
3864	SourceLocation EllipsisLoc;
3865
3866	/// The nested-name-specifier that precedes the name.
3867	NestedNameSpecifierLoc QualifierLoc;
3868
3869	/// Provides source/type location info for the declaration name
3870	/// embedded in the ValueDecl base class.
3871	DeclarationNameLoc DNLoc;
3872
3873	UnresolvedUsingValueDecl(DeclContext *DC, QualType Ty,
3874	SourceLocation UsingLoc,
3875	NestedNameSpecifierLoc QualifierLoc,
3876	const DeclarationNameInfo &NameInfo,
3877	SourceLocation EllipsisLoc)
3878	: ValueDecl(UnresolvedUsingValue, DC,
3879	NameInfo.getLoc(), NameInfo.getName(), Ty),
3880	UsingLocation (UsingLoc), EllipsisLoc (EllipsisLoc),
3881	QualifierLoc (QualifierLoc), DNLoc (NameInfo.getInfo()) {}
3882
3883	void anchor() override;
3884
3885	public:
3886	friend class ASTDeclReader;
3887	friend class ASTDeclWriter;
3888
3889	/// Returns the source location of the 'using' keyword.
3890	SourceLocation getUsingLoc() const { return UsingLocation; }
3891
3892	/// Set the source location of the 'using' keyword.
3893	void setUsingLoc(SourceLocation L) { UsingLocation = L; }
3894
3895	/// Return true if it is a C++03 access declaration (no 'using').
3896	bool isAccessDeclaration() const { return UsingLocation.isInvalid(); }
3897
3898	/// Retrieve the nested-name-specifier that qualifies the name,
3899	/// with source-location information.
3900	NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
3901
3902	/// Retrieve the nested-name-specifier that qualifies the name.
3903	NestedNameSpecifier getQualifier() const* {
3904	return QualifierLoc.getNestedNameSpecifier();
3905	}
3906
3907	DeclarationNameInfo getNameInfo() const {
3908	return DeclarationNameInfo(getDeclName(), getLocation(), DNLoc);
3909	}
3910
3911	/// Determine whether this is a pack expansion.
3912	bool isPackExpansion() const {
3913	return EllipsisLoc.isValid();
3914	}
3915
3916	/// Get the location of the ellipsis if this is a pack expansion.
3917	SourceLocation getEllipsisLoc() const {
3918	return EllipsisLoc;
3919	}
3920
3921	static UnresolvedUsingValueDecl *
3922	Create(ASTContext &C, DeclContext *DC, SourceLocation UsingLoc,
3923	NestedNameSpecifierLoc QualifierLoc,
3924	const DeclarationNameInfo &NameInfo, SourceLocation EllipsisLoc);
3925
3926	static UnresolvedUsingValueDecl *
3927	CreateDeserialized(ASTContext &C, DeclID ID);
3928
3929	SourceRange getSourceRange() const override LLVM_READONLY;
3930
3931	/// Retrieves the canonical declaration of this declaration.
3932	UnresolvedUsingValueDecl *getCanonicalDecl() override {
3933	return getFirstDecl();
3934	}
3935	const UnresolvedUsingValueDecl getCanonicalDecl() const* {
3936	return getFirstDecl();
3937	}
3938
3939	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
3940	static bool classofKind(Kind K) { return K == UnresolvedUsingValue; }
3941	};
3942
3943	/// Represents a dependent using declaration which was marked with
3944	/// \c typename.
3945	///
3946	/// \code
3947	/// template \<class T> class A : public Base<T> {
3948	/// using typename Base<T>::foo;
3949	/// };
3950	/// \endcode
3951	///
3952	/// The type associated with an unresolved using typename decl is
3953	/// currently always a typename type.
3954	class UnresolvedUsingTypenameDecl
3955	: public TypeDecl,
3956	public Mergeable<UnresolvedUsingTypenameDecl> {
3957	friend class ASTDeclReader;
3958
3959	/// The source location of the 'typename' keyword
3960	SourceLocation TypenameLocation;
3961
3962	/// If this is a pack expansion, the location of the '...'.
3963	SourceLocation EllipsisLoc;
3964
3965	/// The nested-name-specifier that precedes the name.
3966	NestedNameSpecifierLoc QualifierLoc;
3967
3968	UnresolvedUsingTypenameDecl(DeclContext *DC, SourceLocation UsingLoc,
3969	SourceLocation TypenameLoc,
3970	NestedNameSpecifierLoc QualifierLoc,
3971	SourceLocation TargetNameLoc,
3972	IdentifierInfo *TargetName,
3973	SourceLocation EllipsisLoc)
3974	: TypeDecl(UnresolvedUsingTypename, DC, TargetNameLoc, TargetName,
3975	UsingLoc),
3976	TypenameLocation (TypenameLoc), EllipsisLoc (EllipsisLoc),
3977	QualifierLoc (QualifierLoc) {}
3978
3979	void anchor() override;
3980
3981	public:
3982	/// Returns the source location of the 'using' keyword.
3983	SourceLocation getUsingLoc() const { return getBeginLoc(); }
3984
3985	/// Returns the source location of the 'typename' keyword.
3986	SourceLocation getTypenameLoc() const { return TypenameLocation; }
3987
3988	/// Retrieve the nested-name-specifier that qualifies the name,
3989	/// with source-location information.
3990	NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
3991
3992	/// Retrieve the nested-name-specifier that qualifies the name.
3993	NestedNameSpecifier getQualifier() const* {
3994	return QualifierLoc.getNestedNameSpecifier();
3995	}
3996
3997	DeclarationNameInfo getNameInfo() const {
3998	return DeclarationNameInfo(getDeclName(), getLocation());
3999	}
4000
4001	/// Determine whether this is a pack expansion.
4002	bool isPackExpansion() const {
4003	return EllipsisLoc.isValid();
4004	}
4005
4006	/// Get the location of the ellipsis if this is a pack expansion.
4007	SourceLocation getEllipsisLoc() const {
4008	return EllipsisLoc;
4009	}
4010
4011	static UnresolvedUsingTypenameDecl *
4012	Create(ASTContext &C, DeclContext *DC, SourceLocation UsingLoc,
4013	SourceLocation TypenameLoc, NestedNameSpecifierLoc QualifierLoc,
4014	SourceLocation TargetNameLoc, DeclarationName TargetName,
4015	SourceLocation EllipsisLoc);
4016
4017	static UnresolvedUsingTypenameDecl *
4018	CreateDeserialized(ASTContext &C, DeclID ID);
4019
4020	/// Retrieves the canonical declaration of this declaration.
4021	UnresolvedUsingTypenameDecl *getCanonicalDecl() override {
4022	return getFirstDecl();
4023	}
4024	const UnresolvedUsingTypenameDecl getCanonicalDecl() const* {
4025	return getFirstDecl();
4026	}
4027
4028	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
4029	static bool classofKind(Kind K) { return K == UnresolvedUsingTypename; }
4030	};
4031
4032	/// This node is generated when a using-declaration that was annotated with
4033	/// __attribute__((using_if_exists)) failed to resolve to a known declaration.
4034	/// In that case, Sema builds a UsingShadowDecl whose target is an instance of
4035	/// this declaration, adding it to the current scope. Referring to this
4036	/// declaration in any way is an error.
4037	class UnresolvedUsingIfExistsDecl final : public NamedDecl {
4038	UnresolvedUsingIfExistsDecl(DeclContext *DC, SourceLocation Loc,
4039	DeclarationName Name);
4040
4041	void anchor() override;
4042
4043	public:
4044	static UnresolvedUsingIfExistsDecl Create(ASTContext &Ctx, DeclContext DC,
4045	SourceLocation Loc,
4046	DeclarationName Name);
4047	static UnresolvedUsingIfExistsDecl *CreateDeserialized(ASTContext &Ctx,
4048	DeclID ID);
4049
4050	static bool classof(const Decl D) { return* classofKind(K: D->getKind()); }
4051	static bool classofKind(Kind K) { return K == Decl::UnresolvedUsingIfExists; }
4052	};
4053
4054	/// Represents a C++11 static_assert declaration.
4055	class StaticAssertDecl : public Decl {
4056	llvm::PointerIntPair<Expr , `1`, bool*> AssertExprAndFailed;
4057	Expr *Message;
4058	SourceLocation RParenLoc;
4059
4060	StaticAssertDecl(DeclContext *DC, SourceLocation StaticAssertLoc,
4061	Expr AssertExpr, Expr Message, SourceLocation RParenLoc,
4062	bool Failed)
4063	: Decl(StaticAssert, DC, StaticAssertLoc),
4064