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

1	//===- DeclBase.h - Base Classes for representing 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	// This file defines the Decl and DeclContext interfaces.
10	//
11	//===----------------------------------------------------------------------===//
12
13	#ifndef LLVM_CLANG_AST_DECLBASE_H
14	#define LLVM_CLANG_AST_DECLBASE_H
15
16	#include "clang/AST/AttrIterator.h"
17	#include "clang/AST/DeclarationName.h"
18	#include "clang/Basic/IdentifierTable.h"
19	#include "clang/Basic/LLVM.h"
20	#include "clang/Basic/SourceLocation.h"
21	#include "clang/Basic/Specifiers.h"
22	#include "llvm/ADT/ArrayRef.h"
23	#include "llvm/ADT/PointerIntPair.h"
24	#include "llvm/ADT/PointerUnion.h"
25	#include "llvm/ADT/iterator.h"
26	#include "llvm/ADT/iterator_range.h"
27	#include "llvm/Support/Casting.h"
28	#include "llvm/Support/Compiler.h"
29	#include "llvm/Support/PrettyStackTrace.h"
30	#include "llvm/Support/VersionTuple.h"
31	#include <algorithm>
32	#include <cassert>
33	#include <cstddef>
34	#include <iterator>
35	#include <string>
36	#include <type_traits>
37	#include <utility>
38
39	namespace clang {
40
41	class ASTContext;
42	class ASTMutationListener;
43	class Attr;
44	class DeclContext;
45	class ExternalSourceSymbolAttr;
46	class FunctionDecl;
47	class FunctionType;
48	class IdentifierInfo;
49	enum Linkage : unsigned char;
50	class LinkageSpecDecl;
51	class Module;
52	class NamedDecl;
53	class ObjCCategoryDecl;
54	class ObjCCategoryImplDecl;
55	class ObjCContainerDecl;
56	class ObjCImplDecl;
57	class ObjCImplementationDecl;
58	class ObjCInterfaceDecl;
59	class ObjCMethodDecl;
60	class ObjCProtocolDecl;
61	struct PrintingPolicy;
62	class RecordDecl;
63	class SourceManager;
64	class Stmt;
65	class StoredDeclsMap;
66	class TemplateDecl;
67	class TranslationUnitDecl;
68	class UsingDirectiveDecl;
69
70	/// Captures the result of checking the availability of a
71	/// declaration.
72	enum AvailabilityResult {
73	AR_Available = `0`,
74	AR_NotYetIntroduced,
75	AR_Deprecated,
76	AR_Unavailable
77	};
78
79	/// Decl - This represents one declaration (or definition), e.g. a variable,
80	/// typedef, function, struct, etc.
81	///
82	/// Note: There are objects tacked on before the beginning* of Decl*
83	/// (and its subclasses) in its Decl::operator new(). Proper alignment
84	/// of all subclasses (not requiring more than the alignment of Decl) is
85	/// asserted in DeclBase.cpp.
86	class alignas(`8`) Decl {
87	public:
88	/// Lists the kind of concrete classes of Decl.
89	enum Kind {
90	#define DECL(DERIVED, BASE) DERIVED,
91	#define ABSTRACT_DECL(DECL)
92	#define DECL_RANGE(BASE, START, END) \
93	first##BASE = START, last##BASE = END,
94	#define LAST_DECL_RANGE(BASE, START, END) \
95	first##BASE = START, last##BASE = END
96	#include "clang/AST/DeclNodes.inc"
97	};
98
99	/// A placeholder type used to construct an empty shell of a
100	/// decl-derived type that will be filled in later (e.g., by some
101	/// deserialization method).
102	struct EmptyShell {};
103
104	/// IdentifierNamespace - The different namespaces in which
105	/// declarations may appear. According to C99 6.2.3, there are
106	/// four namespaces, labels, tags, members and ordinary
107	/// identifiers. C++ describes lookup completely differently:
108	/// certain lookups merely "ignore" certain kinds of declarations,
109	/// usually based on whether the declaration is of a type, etc.
110	///
111	/// These are meant as bitmasks, so that searches in
112	/// C++ can look into the "tag" namespace during ordinary lookup.
113	///
114	/// Decl currently provides 15 bits of IDNS bits.
115	enum IdentifierNamespace {
116	/// Labels, declared with 'x:' and referenced with 'goto x'.
117	IDNS_Label = `0x0001`,
118
119	/// Tags, declared with 'struct foo;' and referenced with
120	/// 'struct foo'. All tags are also types. This is what
121	/// elaborated-type-specifiers look for in C.
122	/// This also contains names that conflict with tags in the
123	/// same scope but that are otherwise ordinary names (non-type
124	/// template parameters and indirect field declarations).
125	IDNS_Tag = `0x0002`,
126
127	/// Types, declared with 'struct foo', typedefs, etc.
128	/// This is what elaborated-type-specifiers look for in C++,
129	/// but note that it's ill-formed to find a non-tag.
130	IDNS_Type = `0x0004`,
131
132	/// Members, declared with object declarations within tag
133	/// definitions. In C, these can only be found by "qualified"
134	/// lookup in member expressions. In C++, they're found by
135	/// normal lookup.
136	IDNS_Member = `0x0008`,
137
138	/// Namespaces, declared with 'namespace foo {}'.
139	/// Lookup for nested-name-specifiers find these.
140	IDNS_Namespace = `0x0010`,
141
142	/// Ordinary names. In C, everything that's not a label, tag,
143	/// member, or function-local extern ends up here.
144	IDNS_Ordinary = `0x0020`,
145
146	/// Objective C \@protocol.
147	IDNS_ObjCProtocol = `0x0040`,
148
149	/// This declaration is a friend function. A friend function
150	/// declaration is always in this namespace but may also be in
151	/// IDNS_Ordinary if it was previously declared.
152	IDNS_OrdinaryFriend = `0x0080`,
153
154	/// This declaration is a friend class. A friend class
155	/// declaration is always in this namespace but may also be in
156	/// IDNS_Tag\|IDNS_Type if it was previously declared.
157	IDNS_TagFriend = `0x0100`,
158
159	/// This declaration is a using declaration. A using declaration
160	/// introduces* a number of other declarations into the current*
161	/// scope, and those declarations use the IDNS of their targets,
162	/// but the actual using declarations go in this namespace.
163	IDNS_Using = `0x0200`,
164
165	/// This declaration is a C++ operator declared in a non-class
166	/// context. All such operators are also in IDNS_Ordinary.
167	/// C++ lexical operator lookup looks for these.
168	IDNS_NonMemberOperator = `0x0400`,
169
170	/// This declaration is a function-local extern declaration of a
171	/// variable or function. This may also be IDNS_Ordinary if it
172	/// has been declared outside any function. These act mostly like
173	/// invisible friend declarations, but are also visible to unqualified
174	/// lookup within the scope of the declaring function.
175	IDNS_LocalExtern = `0x0800`,
176
177	/// This declaration is an OpenMP user defined reduction construction.
178	IDNS_OMPReduction = `0x1000`,
179
180	/// This declaration is an OpenMP user defined mapper.
181	IDNS_OMPMapper = `0x2000`,
182	};
183
184	/// ObjCDeclQualifier - 'Qualifiers' written next to the return and
185	/// parameter types in method declarations. Other than remembering
186	/// them and mangling them into the method's signature string, these
187	/// are ignored by the compiler; they are consumed by certain
188	/// remote-messaging frameworks.
189	///
190	/// in, inout, and out are mutually exclusive and apply only to
191	/// method parameters. bycopy and byref are mutually exclusive and
192	/// apply only to method parameters (?). oneway applies only to
193	/// results. All of these expect their corresponding parameter to
194	/// have a particular type. None of this is currently enforced by
195	/// clang.
196	///
197	/// This should be kept in sync with ObjCDeclSpec::ObjCDeclQualifier.
198	enum ObjCDeclQualifier {
199	OBJC_TQ_None = `0x0`,
200	OBJC_TQ_In = `0x1`,
201	OBJC_TQ_Inout = `0x2`,
202	OBJC_TQ_Out = `0x4`,
203	OBJC_TQ_Bycopy = `0x8`,
204	OBJC_TQ_Byref = `0x10`,
205	OBJC_TQ_Oneway = `0x20`,
206
207	/// The nullability qualifier is set when the nullability of the
208	/// result or parameter was expressed via a context-sensitive
209	/// keyword.
210	OBJC_TQ_CSNullability = `0x40`
211	};
212
213	/// The kind of ownership a declaration has, for visibility purposes.
214	/// This enumeration is designed such that higher values represent higher
215	/// levels of name hiding.
216	enum class ModuleOwnershipKind : unsigned {
217	/// This declaration is not owned by a module.
218	Unowned,
219
220	/// This declaration has an owning module, but is globally visible
221	/// (typically because its owning module is visible and we know that
222	/// modules cannot later become hidden in this compilation).
223	/// After serialization and deserialization, this will be converted
224	/// to VisibleWhenImported.
225	Visible,
226
227	/// This declaration has an owning module, and is visible when that
228	/// module is imported.
229	VisibleWhenImported,
230
231	/// This declaration has an owning module, but is only visible to
232	/// lookups that occur within that module.
233	ModulePrivate
234	};
235
236	protected:
237	/// The next declaration within the same lexical
238	/// DeclContext. These pointers form the linked list that is
239	/// traversed via DeclContext's decls_begin()/decls_end().
240	///
241	/// The extra two bits are used for the ModuleOwnershipKind.
242	llvm::PointerIntPair<Decl *, `2`, ModuleOwnershipKind> NextInContextAndBits;
243
244	private:
245	friend class DeclContext;
246
247	struct MultipleDC {
248	DeclContext *SemanticDC;
249	DeclContext *LexicalDC;
250	};
251
252	/// DeclCtx - Holds either a DeclContext or a MultipleDC.
253	/// For declarations that don't contain C++ scope specifiers, it contains
254	/// the DeclContext where the Decl was declared.
255	/// For declarations with C++ scope specifiers, it contains a MultipleDC*
256	/// with the context where it semantically belongs (SemanticDC) and the
257	/// context where it was lexically declared (LexicalDC).
258	/// e.g.:
259	///
260	/// namespace A {
261	/// void f(); // SemanticDC == LexicalDC == 'namespace A'
262	/// }
263	/// void A::f(); // SemanticDC == namespace 'A'
264	/// // LexicalDC == global namespace
265	llvm::PointerUnion<DeclContext, MultipleDC> DeclCtx;
266
267	bool isInSemaDC() const { return DeclCtx.is<DeclContext*>(); }
268	bool isOutOfSemaDC() const { return DeclCtx.is<MultipleDC*>(); }
269
270	MultipleDC getMultipleDC() const* {
271	return DeclCtx.get<MultipleDC*>();
272	}
273
274	DeclContext getSemanticDC() const* {
275	return DeclCtx.get<DeclContext*>();
276	}
277
278	/// Loc - The location of this decl.
279	SourceLocation Loc;
280
281	/// DeclKind - This indicates which class this is.
282	unsigned DeclKind : `7`;
283
284	/// InvalidDecl - This indicates a semantic error occurred.
285	unsigned InvalidDecl : `1`;
286
287	/// HasAttrs - This indicates whether the decl has attributes or not.
288	unsigned HasAttrs : `1`;
289
290	/// Implicit - Whether this declaration was implicitly generated by
291	/// the implementation rather than explicitly written by the user.
292	unsigned Implicit : `1`;
293
294	/// Whether this declaration was "used", meaning that a definition is
295	/// required.
296	unsigned Used : `1`;
297
298	/// Whether this declaration was "referenced".
299	/// The difference with 'Used' is whether the reference appears in a
300	/// evaluated context or not, e.g. functions used in uninstantiated templates
301	/// are regarded as "referenced" but not "used".
302	unsigned Referenced : `1`;
303
304	/// Whether this declaration is a top-level declaration (function,
305	/// global variable, etc.) that is lexically inside an objc container
306	/// definition.
307	unsigned TopLevelDeclInObjCContainer : `1`;
308
309	/// Whether statistic collection is enabled.
310	static bool StatisticsEnabled;
311
312	protected:
313	friend class ASTDeclReader;
314	friend class ASTDeclWriter;
315	friend class ASTNodeImporter;
316	friend class ASTReader;
317	friend class CXXClassMemberWrapper;
318	friend class LinkageComputer;
319	template<typename decl_type> friend class Redeclarable;
320
321	/// Access - Used by C++ decls for the access specifier.
322	// NOTE: VC++ treats enums as signed, avoid using the AccessSpecifier enum
323	unsigned Access : `2`;
324
325	/// Whether this declaration was loaded from an AST file.
326	unsigned FromASTFile : `1`;
327
328	/// IdentifierNamespace - This specifies what IDNS_ namespace this lives in.*
329	unsigned IdentifierNamespace : `14`;
330
331	/// If 0, we have not computed the linkage of this declaration.
332	/// Otherwise, it is the linkage + 1.
333	mutable unsigned CacheValidAndLinkage : `3`;
334
335	/// Allocate memory for a deserialized declaration.
336	///
337	/// This routine must be used to allocate memory for any declaration that is
338	/// deserialized from a module file.
339	///
340	/// \param Size The size of the allocated object.
341	/// \param Ctx The context in which we will allocate memory.
342	/// \param ID The global ID of the deserialized declaration.
343	/// \param Extra The amount of extra space to allocate after the object.
344	void *operator new(std::size_t Size, const ASTContext &Ctx, unsigned ID,
345	std::size_t Extra = `0`);
346
347	/// Allocate memory for a non-deserialized declaration.
348	void *operator new(std::size_t Size, const ASTContext &Ctx,
349	DeclContext *Parent, std::size_t Extra = `0`);
350
351	private:
352	bool AccessDeclContextSanity() const;
353
354	/// Get the module ownership kind to use for a local lexical child of \p DC,
355	/// which may be either a local or (rarely) an imported declaration.
356	static ModuleOwnershipKind getModuleOwnershipKindForChildOf(DeclContext *DC) {
357	if (DC) {
358	auto *D = cast<Decl>(DC);
359	auto MOK = D->getModuleOwnershipKind();
360	if (MOK != ModuleOwnershipKind::Unowned &&
361	(!D->isFromASTFile() \|\| D->hasLocalOwningModuleStorage()))
362	return MOK;
363	// If D is not local and we have no local module storage, then we don't
364	// need to track module ownership at all.
365	}
366	return ModuleOwnershipKind::Unowned;
367	}
368
369	protected:
370	Decl(Kind DK, DeclContext *DC, SourceLocation L)
371	: NextInContextAndBits (nullptr, getModuleOwnershipKindForChildOf(DC)),
372	DeclCtx (DC), Loc (L), DeclKind(DK), InvalidDecl(false), HasAttrs(false),
373	Implicit(false), Used(false), Referenced(false),
374	TopLevelDeclInObjCContainer(false), Access(AS_none), FromASTFile(`0`),
375	IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
376	CacheValidAndLinkage(`0`) {
377	if (StatisticsEnabled) add(DK);
378	}
379
380	Decl(Kind DK, EmptyShell Empty)
381	: DeclKind(DK), InvalidDecl(false), HasAttrs(false), Implicit(false),
382	Used(false), Referenced(false), TopLevelDeclInObjCContainer(false),
383	Access(AS_none), FromASTFile(`0`),
384	IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
385	CacheValidAndLinkage(`0`) {
386	if (StatisticsEnabled) add(DK);
387	}
388
389	virtual ~Decl();
390
391	/// Update a potentially out-of-date declaration.
392	void updateOutOfDate(IdentifierInfo &II) const;
393
394	Linkage getCachedLinkage() const {
395	return Linkage(CacheValidAndLinkage - `1`);
396	}
397
398	void setCachedLinkage(Linkage L) const {
399	CacheValidAndLinkage = L + `1`;
400	}
401
402	bool hasCachedLinkage() const {
403	return CacheValidAndLinkage;
404	}
405
406	public:
407	/// Source range that this declaration covers.
408	virtual SourceRange getSourceRange() const LLVM_READONLY {
409	return SourceRange (getLocation(), getLocation());
410	}
411
412	SourceLocation getBeginLoc() const LLVM_READONLY {
413	return getSourceRange().getBegin();
414	}
415
416	SourceLocation getEndLoc() const LLVM_READONLY {
417	return getSourceRange().getEnd();
418	}
419
420	SourceLocation getLocation() const { return Loc; }
421	void setLocation(SourceLocation L) { Loc = L; }
422
423	Kind getKind() const { return static_cast<Kind>(DeclKind); }
424	const char getDeclKindName() const*;
425
426	Decl getNextDeclInContext() { return* NextInContextAndBits.getPointer(); }
427	const Decl getNextDeclInContext() const* {return NextInContextAndBits.getPointer();}
428
429	DeclContext *getDeclContext() {
430	if (isInSemaDC())
431	return getSemanticDC();
432	return getMultipleDC()->SemanticDC;
433	}
434	const DeclContext getDeclContext() const* {
435	return const_cast<Decl>(this*)->getDeclContext();
436	}
437
438	/// Find the innermost non-closure ancestor of this declaration,
439	/// walking up through blocks, lambdas, etc. If that ancestor is
440	/// not a code context (!isFunctionOrMethod()), returns null.
441	///
442	/// A declaration may be its own non-closure context.
443	Decl *getNonClosureContext();
444	const Decl getNonClosureContext() const* {
445	return const_cast<Decl>(this*)->getNonClosureContext();
446	}
447
448	TranslationUnitDecl *getTranslationUnitDecl();
449	const TranslationUnitDecl getTranslationUnitDecl() const* {
450	return const_cast<Decl>(this*)->getTranslationUnitDecl();
451	}
452
453	bool isInAnonymousNamespace() const;
454
455	bool isInStdNamespace() const;
456
457	ASTContext &getASTContext() const LLVM_READONLY;
458
459	void setAccess(AccessSpecifier AS) {
460	Access = AS;
461	assert(AccessDeclContextSanity());
462	}
463
464	AccessSpecifier getAccess() const {
465	assert(AccessDeclContextSanity());
466	return AccessSpecifier(Access);
467	}
468
469	/// Retrieve the access specifier for this declaration, even though
470	/// it may not yet have been properly set.
471	AccessSpecifier getAccessUnsafe() const {
472	return AccessSpecifier(Access);
473	}
474
475	bool hasAttrs() const { return HasAttrs; }
476
477	void setAttrs(const AttrVec& Attrs) {
478	return setAttrsImpl(Attrs, getASTContext());
479	}
480
481	AttrVec &getAttrs() {
482	return const_cast<AttrVec&>(const_cast<const Decl>(this*)->getAttrs());
483	}
484
485	const AttrVec &getAttrs() const;
486	void dropAttrs();
487	void addAttr(Attr *A);
488
489	using attr_iterator = AttrVec::const_iterator;
490	using attr_range = llvm::iterator_range<attr_iterator>;
491
492	attr_range attrs() const {
493	return attr_range (attr_begin(), attr_end());
494	}
495
496	attr_iterator attr_begin() const {
497	return hasAttrs() ? getAttrs().begin() : nullptr;
498	}
499	attr_iterator attr_end() const {
500	return hasAttrs() ? getAttrs().end() : nullptr;
501	}
502
503	template <typename T>
504	void dropAttr() {
505	if (!HasAttrs) return;
506
507	AttrVec &Vec = getAttrs();
508	Vec.erase(std::remove_if(Vec.begin(), Vec.end(), isa<T, Attr*>), Vec.end());
509
510	if (Vec.empty())
511	HasAttrs = false;
512	}
513
514	template <typename T>
515	llvm::iterator_range<specific_attr_iterator<T>> specific_attrs() const {
516	return llvm::make_range(specific_attr_begin<T>(), specific_attr_end<T>());
517	}
518
519	template <typename T>
520	specific_attr_iterator<T> specific_attr_begin() const {
521	return specific_attr_iterator<T>(attr_begin());
522	}
523
524	template <typename T>
525	specific_attr_iterator<T> specific_attr_end() const {
526	return specific_attr_iterator<T>(attr_end());
527	}
528
529	template<typename T> T getAttr() const* {
530	return hasAttrs() ? getSpecificAttr<T>(getAttrs()) : nullptr;
531	}
532
533	template<typename T> bool hasAttr() const {
534	return hasAttrs() && hasSpecificAttr<T>(getAttrs());
535	}
536
537	/// getMaxAlignment - return the maximum alignment specified by attributes
538	/// on this decl, 0 if there are none.
539	unsigned getMaxAlignment() const;
540
541	/// setInvalidDecl - Indicates the Decl had a semantic error. This
542	/// allows for graceful error recovery.
543	void setInvalidDecl(bool Invalid = true);
544	bool isInvalidDecl() const { return (bool) InvalidDecl; }
545
546	/// isImplicit - Indicates whether the declaration was implicitly
547	/// generated by the implementation. If false, this declaration
548	/// was written explicitly in the source code.
549	bool isImplicit() const { return Implicit; }
550	void setImplicit(bool I = true) { Implicit = I; }
551
552	/// Whether any* (re-)declaration of the entity was used, meaning that*
553	/// a definition is required.
554	///
555	/// \param CheckUsedAttr When true, also consider the "used" attribute
556	/// (in addition to the "used" bit set by \c setUsed()) when determining
557	/// whether the function is used.
558	bool isUsed(bool CheckUsedAttr = true) const;
559
560	/// Set whether the declaration is used, in the sense of odr-use.
561	///
562	/// This should only be used immediately after creating a declaration.
563	/// It intentionally doesn't notify any listeners.
564	void setIsUsed() { getCanonicalDecl()->Used = true; }
565
566	/// Mark the declaration used, in the sense of odr-use.
567	///
568	/// This notifies any mutation listeners in addition to setting a bit
569	/// indicating the declaration is used.
570	void markUsed(ASTContext &C);
571
572	/// Whether any declaration of this entity was referenced.
573	bool isReferenced() const;
574
575	/// Whether this declaration was referenced. This should not be relied
576	/// upon for anything other than debugging.
577	bool isThisDeclarationReferenced() const { return Referenced; }
578
579	void setReferenced(bool R = true) { Referenced = R; }
580
581	/// Whether this declaration is a top-level declaration (function,
582	/// global variable, etc.) that is lexically inside an objc container
583	/// definition.
584	bool isTopLevelDeclInObjCContainer() const {
585	return TopLevelDeclInObjCContainer;
586	}
587
588	void setTopLevelDeclInObjCContainer(bool V = true) {
589	TopLevelDeclInObjCContainer = V;
590	}
591
592	/// Looks on this and related declarations for an applicable
593	/// external source symbol attribute.
594	ExternalSourceSymbolAttr getExternalSourceSymbolAttr() const*;
595
596	/// Whether this declaration was marked as being private to the
597	/// module in which it was defined.
598	bool isModulePrivate() const {
599	return getModuleOwnershipKind() == ModuleOwnershipKind::ModulePrivate;
600	}
601
602	/// Whether this declaration is exported (by virtue of being lexically
603	/// within an ExportDecl or by being a NamespaceDecl).
604	bool isExported() const;
605
606	/// Return true if this declaration has an attribute which acts as
607	/// definition of the entity, such as 'alias' or 'ifunc'.
608	bool hasDefiningAttr() const;
609
610	/// Return this declaration's defining attribute if it has one.
611	const Attr getDefiningAttr() const*;
612
613	protected:
614	/// Specify that this declaration was marked as being private
615	/// to the module in which it was defined.
616	void setModulePrivate() {
617	// The module-private specifier has no effect on unowned declarations.
618	// FIXME: We should track this in some way for source fidelity.
619	if (getModuleOwnershipKind() == ModuleOwnershipKind::Unowned)
620	return;
621	setModuleOwnershipKind(ModuleOwnershipKind::ModulePrivate);
622	}
623
624	/// Set the owning module ID.
625	void setOwningModuleID(unsigned ID) {
626	assert(isFromASTFile() && "Only works on a deserialized declaration");
627	((unsigned)this** - `2`) = ID;
628	}
629
630	public:
631	/// Determine the availability of the given declaration.
632	///
633	/// This routine will determine the most restrictive availability of
634	/// the given declaration (e.g., preferring 'unavailable' to
635	/// 'deprecated').
636	///
637	/// \param Message If non-NULL and the result is not \c
638	/// AR_Available, will be set to a (possibly empty) message
639	/// describing why the declaration has not been introduced, is
640	/// deprecated, or is unavailable.
641	///
642	/// \param EnclosingVersion The version to compare with. If empty, assume the
643	/// deployment target version.
644	///
645	/// \param RealizedPlatform If non-NULL and the availability result is found
646	/// in an available attribute it will set to the platform which is written in
647	/// the available attribute.
648	AvailabilityResult
649	getAvailability(std::string Message = nullptr*,
650	VersionTuple EnclosingVersion = VersionTuple (),
651	StringRef RealizedPlatform = nullptr) const*;
652
653	/// Retrieve the version of the target platform in which this
654	/// declaration was introduced.
655	///
656	/// \returns An empty version tuple if this declaration has no 'introduced'
657	/// availability attributes, or the version tuple that's specified in the
658	/// attribute otherwise.
659	VersionTuple getVersionIntroduced() const;
660
661	/// Determine whether this declaration is marked 'deprecated'.
662	///
663	/// \param Message If non-NULL and the declaration is deprecated,
664	/// this will be set to the message describing why the declaration
665	/// was deprecated (which may be empty).
666	bool isDeprecated(std::string Message = nullptr) const* {
667	return getAvailability(Message) == AR_Deprecated;
668	}
669
670	/// Determine whether this declaration is marked 'unavailable'.
671	///
672	/// \param Message If non-NULL and the declaration is unavailable,
673	/// this will be set to the message describing why the declaration
674	/// was made unavailable (which may be empty).
675	bool isUnavailable(std::string Message = nullptr) const* {
676	return getAvailability(Message) == AR_Unavailable;
677	}
678
679	/// Determine whether this is a weak-imported symbol.
680	///
681	/// Weak-imported symbols are typically marked with the
682	/// 'weak_import' attribute, but may also be marked with an
683	/// 'availability' attribute where we're targing a platform prior to
684	/// the introduction of this feature.
685	bool isWeakImported() const;
686
687	/// Determines whether this symbol can be weak-imported,
688	/// e.g., whether it would be well-formed to add the weak_import
689	/// attribute.
690	///
691	/// \param IsDefinition Set to \c true to indicate that this
692	/// declaration cannot be weak-imported because it has a definition.
693	bool canBeWeakImported(bool &IsDefinition) const;
694
695	/// Determine whether this declaration came from an AST file (such as
696	/// a precompiled header or module) rather than having been parsed.
697	bool isFromASTFile() const { return FromASTFile; }
698
699	/// Retrieve the global declaration ID associated with this
700	/// declaration, which specifies where this Decl was loaded from.
701	unsigned getGlobalID() const {
702	if (isFromASTFile())
703	return ((const* unsigned)this* - `1`);
704	return `0`;
705	}
706
707	/// Retrieve the global ID of the module that owns this particular
708	/// declaration.
709	unsigned getOwningModuleID() const {
710	if (isFromASTFile())
711	return ((const* unsigned)this* - `2`);
712	return `0`;
713	}
714
715	private:
716	Module getOwningModuleSlow() const*;
717
718	protected:
719	bool hasLocalOwningModuleStorage() const;
720
721	public:
722	/// Get the imported owning module, if this decl is from an imported
723	/// (non-local) module.
724	Module getImportedOwningModule() const* {
725	if (!isFromASTFile() \|\| !hasOwningModule())
726	return nullptr;
727
728	return getOwningModuleSlow();
729	}
730
731	/// Get the local owning module, if known. Returns nullptr if owner is
732	/// not yet known or declaration is not from a module.
733	Module getLocalOwningModule() const* {
734	if (isFromASTFile() \|\| !hasOwningModule())
735	return nullptr;
736
737	assert(hasLocalOwningModuleStorage() &&
738	"owned local decl but no local module storage");
739	return reinterpret_cast<Module *const >(this*)[-`1`];
740	}
741	void setLocalOwningModule(Module *M) {
742	assert(!isFromASTFile() && hasOwningModule() &&
743	hasLocalOwningModuleStorage() &&
744	"should not have a cached owning module");
745	reinterpret_cast<Module >(this**)[-`1`] = M;
746	}
747
748	/// Is this declaration owned by some module?
749	bool hasOwningModule() const {
750	return getModuleOwnershipKind() != ModuleOwnershipKind::Unowned;
751	}
752
753	/// Get the module that owns this declaration (for visibility purposes).
754	Module getOwningModule() const* {
755	return isFromASTFile() ? getImportedOwningModule() : getLocalOwningModule();
756	}
757
758	/// Get the module that owns this declaration for linkage purposes.
759	/// There only ever is such a module under the C++ Modules TS.
760	///
761	/// \param IgnoreLinkage Ignore the linkage of the entity; assume that
762	/// all declarations in a global module fragment are unowned.
763	Module getOwningModuleForLinkage(bool* IgnoreLinkage = false) const;
764
765	/// Determine whether this declaration might be hidden from name
766	/// lookup. Note that the declaration might be visible even if this returns
767	/// \c false, if the owning module is visible within the query context.
768	// FIXME: Rename this to make it clearer what it does.
769	bool isHidden() const {
770	return (int)getModuleOwnershipKind() > (int)ModuleOwnershipKind::Visible;
771	}
772
773	/// Set that this declaration is globally visible, even if it came from a
774	/// module that is not visible.
775	void setVisibleDespiteOwningModule() {
776	if (isHidden())
777	setModuleOwnershipKind(ModuleOwnershipKind::Visible);
778	}
779
780	/// Get the kind of module ownership for this declaration.
781	ModuleOwnershipKind getModuleOwnershipKind() const {
782	return NextInContextAndBits.getInt();
783	}
784
785	/// Set whether this declaration is hidden from name lookup.
786	void setModuleOwnershipKind(ModuleOwnershipKind MOK) {
787	assert(!(getModuleOwnershipKind() == ModuleOwnershipKind::Unowned &&
788	MOK != ModuleOwnershipKind::Unowned && !isFromASTFile() &&
789	!hasLocalOwningModuleStorage()) &&
790	"no storage available for owning module for this declaration");
791	NextInContextAndBits.setInt(MOK);
792	}
793
794	unsigned getIdentifierNamespace() const {
795	return IdentifierNamespace;
796	}
797
798	bool isInIdentifierNamespace(unsigned NS) const {
799	return getIdentifierNamespace() & NS;
800	}
801
802	static unsigned getIdentifierNamespaceForKind(Kind DK);
803
804	bool hasTagIdentifierNamespace() const {
805	return isTagIdentifierNamespace(getIdentifierNamespace());
806	}
807
808	static bool isTagIdentifierNamespace(unsigned NS) {
809	// TagDecls have Tag and Type set and may also have TagFriend.
810	return (NS & ~IDNS_TagFriend) == (IDNS_Tag \| IDNS_Type);
811	}
812
813	/// getLexicalDeclContext - The declaration context where this Decl was
814	/// lexically declared (LexicalDC). May be different from
815	/// getDeclContext() (SemanticDC).
816	/// e.g.:
817	///
818	/// namespace A {
819	/// void f(); // SemanticDC == LexicalDC == 'namespace A'
820	/// }
821	/// void A::f(); // SemanticDC == namespace 'A'
822	/// // LexicalDC == global namespace
823	DeclContext *getLexicalDeclContext() {
824	if (isInSemaDC())
825	return getSemanticDC();
826	return getMultipleDC()->LexicalDC;
827	}
828	const DeclContext getLexicalDeclContext() const* {
829	return const_cast<Decl>(this*)->getLexicalDeclContext();
830	}
831
832	/// Determine whether this declaration is declared out of line (outside its
833	/// semantic context).
834	virtual bool isOutOfLine() const;
835
836	/// setDeclContext - Set both the semantic and lexical DeclContext
837	/// to DC.
838	void setDeclContext(DeclContext *DC);
839
840	void setLexicalDeclContext(DeclContext *DC);
841
842	/// Determine whether this declaration is a templated entity (whether it is
843	// within the scope of a template parameter).
844	bool isTemplated() const;
845
846	/// isDefinedOutsideFunctionOrMethod - This predicate returns true if this
847	/// scoped decl is defined outside the current function or method. This is
848	/// roughly global variables and functions, but also handles enums (which
849	/// could be defined inside or outside a function etc).
850	bool isDefinedOutsideFunctionOrMethod() const {
851	return getParentFunctionOrMethod() == nullptr;
852	}
853
854	/// Returns true if this declaration lexically is inside a function.
855	/// It recognizes non-defining declarations as well as members of local
856	/// classes:
857	/// \code
858	/// void foo() { void bar(); }
859	/// void foo2() { class ABC { void bar(); }; }
860	/// \endcode
861	bool isLexicallyWithinFunctionOrMethod() const;
862
863	/// If this decl is defined inside a function/method/block it returns
864	/// the corresponding DeclContext, otherwise it returns null.
865	const DeclContext getParentFunctionOrMethod() const*;
866	DeclContext *getParentFunctionOrMethod() {
867	return const_cast<DeclContext*>(
868	const_cast<const Decl>(this*)->getParentFunctionOrMethod());
869	}
870
871	/// Retrieves the "canonical" declaration of the given declaration.
872	virtual Decl getCanonicalDecl() { return* this; }
873	const Decl getCanonicalDecl() const* {
874	return const_cast<Decl>(this*)->getCanonicalDecl();
875	}
876
877	/// Whether this particular Decl is a canonical one.
878	bool isCanonicalDecl() const { return getCanonicalDecl() == this; }
879
880	protected:
881	/// Returns the next redeclaration or itself if this is the only decl.
882	///
883	/// Decl subclasses that can be redeclared should override this method so that
884	/// Decl::redecl_iterator can iterate over them.
885	virtual Decl getNextRedeclarationImpl() { return* this; }
886
887	/// Implementation of getPreviousDecl(), to be overridden by any
888	/// subclass that has a redeclaration chain.
889	virtual Decl getPreviousDeclImpl() { return* nullptr; }
890
891	/// Implementation of getMostRecentDecl(), to be overridden by any
892	/// subclass that has a redeclaration chain.
893	virtual Decl getMostRecentDeclImpl() { return* this; }
894
895	public:
896	/// Iterates through all the redeclarations of the same decl.
897	class redecl_iterator {
898	/// Current - The current declaration.
899	Decl Current = nullptr*;
900	Decl *Starter;
901
902	public:
903	using value_type = Decl *;
904	using reference = const value_type &;
905	using pointer = const value_type *;
906	using iterator_category = std::forward_iterator_tag;
907	using difference_type = std::ptrdiff_t;
908
909	redecl_iterator() = default;
910	explicit redecl_iterator(Decl *C) : Current(C), Starter(C) {}
911
912	reference operator() const* { return Current; }
913	value_type operator->() const { return Current; }
914
915	redecl_iterator& operator++() {
916	assert(Current && "Advancing while iterator has reached end");
917	// Get either previous decl or latest decl.
918	Decl *Next = Current->getNextRedeclarationImpl();
919	assert(Next && "Should return next redeclaration or itself, never null!");
920	Current = (Next != Starter) ? Next : nullptr;
921	return *this;
922	}
923
924	redecl_iterator operator++(int) {
925	redecl_iterator tmp(*this);
926	++(*this);
927	return tmp;
928	}
929
930	friend bool operator==(redecl_iterator x, redecl_iterator y) {
931	return x.Current == y.Current;
932	}
933
934	friend bool operator!=(redecl_iterator x, redecl_iterator y) {
935	return x.Current != y.Current;
936	}
937	};
938
939	using redecl_range = llvm::iterator_range<redecl_iterator>;
940
941	/// Returns an iterator range for all the redeclarations of the same
942	/// decl. It will iterate at least once (when this decl is the only one).
943	redecl_range redecls() const {
944	return redecl_range (redecls_begin(), redecls_end());
945	}
946
947	redecl_iterator redecls_begin() const {
948	return redecl_iterator (const_cast<Decl >(this*));
949	}
950
951	redecl_iterator redecls_end() const { return redecl_iterator (); }
952
953	/// Retrieve the previous declaration that declares the same entity
954	/// as this declaration, or NULL if there is no previous declaration.
955	Decl getPreviousDecl() { return* getPreviousDeclImpl(); }
956
957	/// Retrieve the most recent declaration that declares the same entity
958	/// as this declaration, or NULL if there is no previous declaration.
959	const Decl getPreviousDecl() const* {
960	return const_cast<Decl >(this*)->getPreviousDeclImpl();
961	}
962
963	/// True if this is the first declaration in its redeclaration chain.
964	bool isFirstDecl() const {
965	return getPreviousDecl() == nullptr;
966	}
967
968	/// Retrieve the most recent declaration that declares the same entity
969	/// as this declaration (which may be this declaration).
970	Decl getMostRecentDecl() { return* getMostRecentDeclImpl(); }
971
972	/// Retrieve the most recent declaration that declares the same entity
973	/// as this declaration (which may be this declaration).
974	const Decl getMostRecentDecl() const* {
975	return const_cast<Decl >(this*)->getMostRecentDeclImpl();
976	}
977
978	/// getBody - If this Decl represents a declaration for a body of code,
979	/// such as a function or method definition, this method returns the
980	/// top-level Stmt of that body. Otherwise this method returns null.*
981	virtual Stmt* getBody() const { return nullptr; }
982
983	/// Returns true if this \c Decl represents a declaration for a body of
984	/// code, such as a function or method definition.
985	/// Note that \c hasBody can also return true if any redeclaration of this
986	/// \c Decl represents a declaration for a body of code.
987	virtual bool hasBody() const { return getBody() != nullptr; }
988
989	/// getBodyRBrace - Gets the right brace of the body, if a body exists.
990	/// This works whether the body is a CompoundStmt or a CXXTryStmt.
991	SourceLocation getBodyRBrace() const;
992
993	// global temp stats (until we have a per-module visitor)
994	static void add(Kind k);
995	static void EnableStatistics();
996	static void PrintStats();
997
998	/// isTemplateParameter - Determines whether this declaration is a
999	/// template parameter.
1000	bool isTemplateParameter() const;
1001
1002	/// isTemplateParameter - Determines whether this declaration is a
1003	/// template parameter pack.
1004	bool isTemplateParameterPack() const;
1005
1006	/// Whether this declaration is a parameter pack.
1007	bool isParameterPack() const;
1008
1009	/// returns true if this declaration is a template
1010	bool isTemplateDecl() const;
1011
1012	/// Whether this declaration is a function or function template.
1013	bool isFunctionOrFunctionTemplate() const {
1014	return (DeclKind >= Decl::firstFunction &&
1015	DeclKind <= Decl::lastFunction) \|\|
1016	DeclKind == FunctionTemplate;
1017	}
1018
1019	/// If this is a declaration that describes some template, this
1020	/// method returns that template declaration.
1021	TemplateDecl getDescribedTemplate() const*;
1022
1023	/// Returns the function itself, or the templated function if this is a
1024	/// function template.
1025	FunctionDecl *getAsFunction() LLVM_READONLY;
1026
1027	const FunctionDecl getAsFunction() const* {
1028	return const_cast<Decl >(this*)->getAsFunction();
1029	}
1030
1031	/// Changes the namespace of this declaration to reflect that it's
1032	/// a function-local extern declaration.
1033	///
1034	/// These declarations appear in the lexical context of the extern
1035	/// declaration, but in the semantic context of the enclosing namespace
1036	/// scope.
1037	void setLocalExternDecl() {
1038	Decl *Prev = getPreviousDecl();
1039	IdentifierNamespace &= ~IDNS_Ordinary;
1040
1041	// It's OK for the declaration to still have the "invisible friend" flag or
1042	// the "conflicts with tag declarations in this scope" flag for the outer
1043	// scope.
1044	assert((IdentifierNamespace & ~(IDNS_OrdinaryFriend \| IDNS_Tag)) == `0` &&
1045	"namespace is not ordinary");
1046
1047	IdentifierNamespace \|= IDNS_LocalExtern;
1048	if (Prev && Prev->getIdentifierNamespace() & IDNS_Ordinary)
1049	IdentifierNamespace \|= IDNS_Ordinary;
1050	}
1051
1052	/// Determine whether this is a block-scope declaration with linkage.
1053	/// This will either be a local variable declaration declared 'extern', or a
1054	/// local function declaration.
1055	bool isLocalExternDecl() {
1056	return IdentifierNamespace & IDNS_LocalExtern;
1057	}
1058
1059	/// Changes the namespace of this declaration to reflect that it's
1060	/// the object of a friend declaration.
1061	///
1062	/// These declarations appear in the lexical context of the friending
1063	/// class, but in the semantic context of the actual entity. This property
1064	/// applies only to a specific decl object; other redeclarations of the
1065	/// same entity may not (and probably don't) share this property.
1066	void setObjectOfFriendDecl(bool PerformFriendInjection = false) {
1067	unsigned OldNS = IdentifierNamespace;
1068	assert((OldNS & (IDNS_Tag \| IDNS_Ordinary \|
1069	IDNS_TagFriend \| IDNS_OrdinaryFriend \|
1070	IDNS_LocalExtern \| IDNS_NonMemberOperator)) &&
1071	"namespace includes neither ordinary nor tag");
1072	assert(!(OldNS & ~(IDNS_Tag \| IDNS_Ordinary \| IDNS_Type \|
1073	IDNS_TagFriend \| IDNS_OrdinaryFriend \|
1074	IDNS_LocalExtern \| IDNS_NonMemberOperator)) &&
1075	"namespace includes other than ordinary or tag");
1076
1077	Decl *Prev = getPreviousDecl();
1078	IdentifierNamespace &= ~(IDNS_Ordinary \| IDNS_Tag \| IDNS_Type);
1079
1080	if (OldNS & (IDNS_Tag \| IDNS_TagFriend)) {
1081	IdentifierNamespace \|= IDNS_TagFriend;
1082	if (PerformFriendInjection \|\|
1083	(Prev && Prev->getIdentifierNamespace() & IDNS_Tag))
1084	IdentifierNamespace \|= IDNS_Tag \| IDNS_Type;
1085	}
1086
1087	if (OldNS & (IDNS_Ordinary \| IDNS_OrdinaryFriend \|
1088	IDNS_LocalExtern \| IDNS_NonMemberOperator)) {
1089	IdentifierNamespace \|= IDNS_OrdinaryFriend;
1090	if (PerformFriendInjection \|\|
1091	(Prev && Prev->getIdentifierNamespace() & IDNS_Ordinary))
1092	IdentifierNamespace \|= IDNS_Ordinary;
1093	}
1094	}
1095
1096	enum FriendObjectKind {
1097	FOK_None, ///< Not a friend object.
1098	FOK_Declared, ///< A friend of a previously-declared entity.
1099	FOK_Undeclared ///< A friend of a previously-undeclared entity.
1100	};
1101
1102	/// Determines whether this declaration is the object of a
1103	/// friend declaration and, if so, what kind.
1104	///
1105	/// There is currently no direct way to find the associated FriendDecl.
1106	FriendObjectKind getFriendObjectKind() const {
1107	unsigned mask =
1108	(IdentifierNamespace & (IDNS_TagFriend \| IDNS_OrdinaryFriend));
1109	if (!mask) return FOK_None;
1110	return (IdentifierNamespace & (IDNS_Tag \| IDNS_Ordinary) ? FOK_Declared
1111	: FOK_Undeclared);
1112	}
1113
1114	/// Specifies that this declaration is a C++ overloaded non-member.
1115	void setNonMemberOperator() {
1116	assert(getKind() == Function \|\| getKind() == FunctionTemplate);
1117	assert((IdentifierNamespace & IDNS_Ordinary) &&
1118	"visible non-member operators should be in ordinary namespace");
1119	IdentifierNamespace \|= IDNS_NonMemberOperator;
1120	}
1121
1122	static bool classofKind(Kind K) { return true; }
1123	static DeclContext castToDeclContext(const* Decl *);
1124	static Decl castFromDeclContext(const* DeclContext *);
1125
1126	void print(raw_ostream &Out, unsigned Indentation = `0`,
1127	bool PrintInstantiation = false) const;
1128	void print(raw_ostream &Out, const PrintingPolicy &Policy,
1129	unsigned Indentation = `0`, bool PrintInstantiation = false) const;
1130	static void printGroup(Decl** Begin, unsigned NumDecls,
1131	raw_ostream &Out, const PrintingPolicy &Policy,
1132	unsigned Indentation = `0`);
1133
1134	// Debuggers don't usually respect default arguments.
1135	void dump() const;
1136
1137	// Same as dump(), but forces color printing.
1138	void dumpColor() const;
1139
1140	void dump(raw_ostream &Out, bool Deserialize = false) const;
1141
1142	/// \return Unique reproducible object identifier
1143	int64_t getID() const;
1144
1145	/// Looks through the Decl's underlying type to extract a FunctionType
1146	/// when possible. Will return null if the type underlying the Decl does not
1147	/// have a FunctionType.
1148	const FunctionType getFunctionType(bool* BlocksToo = true) const;
1149
1150	private:
1151	void setAttrsImpl(const AttrVec& Attrs, ASTContext &Ctx);
1152	void setDeclContextsImpl(DeclContext SemaDC, DeclContext LexicalDC,
1153	ASTContext &Ctx);
1154
1155	protected:
1156	ASTMutationListener getASTMutationListener() const*;
1157	};
1158
1159	/// Determine whether two declarations declare the same entity.
1160	inline bool declaresSameEntity(const Decl D1, const* Decl *D2) {
1161	if (!D1 \|\| !D2)
1162	return false;
1163
1164	if (D1 == D2)
1165	return true;
1166
1167	return D1->getCanonicalDecl() == D2->getCanonicalDecl();
1168	}
1169
1170	/// PrettyStackTraceDecl - If a crash occurs, indicate that it happened when
1171	/// doing something to a specific decl.
1172	class PrettyStackTraceDecl : public llvm::PrettyStackTraceEntry {
1173	const Decl *TheDecl;
1174	SourceLocation Loc;
1175	SourceManager &SM;
1176	const char *Message;
1177
1178	public:
1179	PrettyStackTraceDecl(const Decl *theDecl, SourceLocation L,
1180	SourceManager &sm, const char *Msg)
1181	: TheDecl(theDecl), Loc (L), SM(sm), Message(Msg) {}
1182
1183	void print(raw_ostream &OS) const override;
1184	};
1185
1186	/// The results of name lookup within a DeclContext. This is either a
1187	/// single result (with no stable storage) or a collection of results (with
1188	/// stable storage provided by the lookup table).
1189	class DeclContextLookupResult {
1190	using ResultTy = ArrayRef<NamedDecl *>;
1191
1192	ResultTy Result;
1193
1194	// If there is only one lookup result, it would be invalidated by
1195	// reallocations of the name table, so store it separately.
1196	NamedDecl Single = nullptr*;
1197
1198	static NamedDecl *const SingleElementDummyList;
1199
1200	public:
1201	DeclContextLookupResult() = default;
1202	DeclContextLookupResult(ArrayRef<NamedDecl *> Result)
1203	: Result (Result) {}
1204	DeclContextLookupResult(NamedDecl *Single)
1205	: Result (SingleElementDummyList), Single(Single) {}
1206
1207	class iterator;
1208
1209	using IteratorBase =
1210	llvm::iterator_adaptor_base<iterator, ResultTy::iterator,
1211	std::random_access_iterator_tag,
1212	NamedDecl *const>;
1213
1214	class iterator : public IteratorBase {
1215	value_type SingleElement;
1216
1217	public:
1218	explicit iterator(pointer Pos, value_type Single = nullptr)
1219	: IteratorBase (Pos), SingleElement(Single) {}
1220
1221	reference operator() const* {
1222	return SingleElement ? SingleElement : IteratorBase::operator*();
1223	}
1224	};
1225
1226	using const_iterator = iterator;
1227	using pointer = iterator::pointer;
1228	using reference = iterator::reference;
1229
1230	iterator begin() const { return iterator (Result.begin(), Single); }
1231	iterator end() const { return iterator (Result.end(), Single); }
1232
1233	bool empty() const { return Result.empty(); }
1234	pointer data() const { return Single ? &Single : Result.data(); }
1235	size_t size() const { return Single ? `1` : Result.size(); }
1236	reference front() const { return Single ? Single : Result.front(); }
1237	reference back() const { return Single ? Single : Result.back(); }
1238	reference operator[](size_t N) const { return Single ? Single : Result [N]; }
1239
1240	// FIXME: Remove this from the interface
1241	DeclContextLookupResult slice(size_t N) const {
1242	DeclContextLookupResult Sliced = Result.slice(N);
1243	Sliced.Single = Single;
1244	return Sliced;
1245	}
1246	};
1247
1248	/// DeclContext - This is used only as base class of specific decl types that
1249	/// can act as declaration contexts. These decls are (only the top classes
1250	/// that directly derive from DeclContext are mentioned, not their subclasses):
1251	///
1252	/// TranslationUnitDecl
1253	/// ExternCContext
1254	/// NamespaceDecl
1255	/// TagDecl
1256	/// OMPDeclareReductionDecl
1257	/// OMPDeclareMapperDecl
1258	/// FunctionDecl
1259	/// ObjCMethodDecl
1260	/// ObjCContainerDecl
1261	/// LinkageSpecDecl
1262	/// ExportDecl
1263	/// BlockDecl
1264	/// CapturedDecl
1265	class DeclContext {
1266	/// For makeDeclVisibleInContextImpl
1267	friend class ASTDeclReader;
1268	/// For reconcileExternalVisibleStorage, CreateStoredDeclsMap,
1269	/// hasNeedToReconcileExternalVisibleStorage
1270	friend class ExternalASTSource;
1271	/// For CreateStoredDeclsMap
1272	friend class DependentDiagnostic;
1273	/// For hasNeedToReconcileExternalVisibleStorage,
1274	/// hasLazyLocalLexicalLookups, hasLazyExternalLexicalLookups
1275	friend class ASTWriter;
1276
1277	// We use uint64_t in the bit-fields below since some bit-fields
1278	// cross the unsigned boundary and this breaks the packing.
1279
1280	/// Stores the bits used by DeclContext.
1281	/// If modified NumDeclContextBit, the ctor of DeclContext and the accessor
1282	/// methods in DeclContext should be updated appropriately.
1283	class DeclContextBitfields {
1284	friend class DeclContext;
1285	/// DeclKind - This indicates which class this is.
1286	uint64_t DeclKind : `7`;
1287
1288	/// Whether this declaration context also has some external
1289	/// storage that contains additional declarations that are lexically
1290	/// part of this context.
1291	mutable uint64_t ExternalLexicalStorage : `1`;
1292
1293	/// Whether this declaration context also has some external
1294	/// storage that contains additional declarations that are visible
1295	/// in this context.
1296	mutable uint64_t ExternalVisibleStorage : `1`;
1297
1298	/// Whether this declaration context has had externally visible
1299	/// storage added since the last lookup. In this case, \c LookupPtr's
1300	/// invariant may not hold and needs to be fixed before we perform
1301	/// another lookup.
1302	mutable uint64_t NeedToReconcileExternalVisibleStorage : `1`;
1303
1304	/// If \c true, this context may have local lexical declarations
1305	/// that are missing from the lookup table.
1306	mutable uint64_t HasLazyLocalLexicalLookups : `1`;
1307
1308	/// If \c true, the external source may have lexical declarations
1309	/// that are missing from the lookup table.
1310	mutable uint64_t HasLazyExternalLexicalLookups : `1`;
1311
1312	/// If \c true, lookups should only return identifier from
1313	/// DeclContext scope (for example TranslationUnit). Used in
1314	/// LookupQualifiedName()
1315	mutable uint64_t UseQualifiedLookup : `1`;
1316	};
1317
1318	/// Number of bits in DeclContextBitfields.
1319	enum { NumDeclContextBits = `13` };
1320
1321	/// Stores the bits used by TagDecl.
1322	/// If modified NumTagDeclBits and the accessor
1323	/// methods in TagDecl should be updated appropriately.
1324	class TagDeclBitfields {
1325	friend class TagDecl;
1326	/// For the bits in DeclContextBitfields
1327	uint64_t : NumDeclContextBits;
1328
1329	/// The TagKind enum.
1330	uint64_t TagDeclKind : `3`;
1331
1332	/// True if this is a definition ("struct foo {};"), false if it is a
1333	/// declaration ("struct foo;"). It is not considered a definition
1334	/// until the definition has been fully processed.
1335	uint64_t IsCompleteDefinition : `1`;
1336
1337	/// True if this is currently being defined.
1338	uint64_t IsBeingDefined : `1`;
1339
1340	/// True if this tag declaration is "embedded" (i.e., defined or declared
1341	/// for the very first time) in the syntax of a declarator.
1342	uint64_t IsEmbeddedInDeclarator : `1`;
1343
1344	/// True if this tag is free standing, e.g. "struct foo;".
1345	uint64_t IsFreeStanding : `1`;
1346
1347	/// Indicates whether it is possible for declarations of this kind
1348	/// to have an out-of-date definition.
1349	///
1350	/// This option is only enabled when modules are enabled.
1351	uint64_t MayHaveOutOfDateDef : `1`;
1352
1353	/// Has the full definition of this type been required by a use somewhere in
1354	/// the TU.
1355	uint64_t IsCompleteDefinitionRequired : `1`;
1356	};
1357
1358	/// Number of non-inherited bits in TagDeclBitfields.
1359	enum { NumTagDeclBits = `9` };
1360
1361	/// Stores the bits used by EnumDecl.
1362	/// If modified NumEnumDeclBit and the accessor
1363	/// methods in EnumDecl should be updated appropriately.
1364	class EnumDeclBitfields {
1365	friend class EnumDecl;
1366	/// For the bits in DeclContextBitfields.
1367	uint64_t : NumDeclContextBits;
1368	/// For the bits in TagDeclBitfields.
1369	uint64_t : NumTagDeclBits;
1370
1371	/// Width in bits required to store all the non-negative
1372	/// enumerators of this enum.
1373	uint64_t NumPositiveBits : `8`;
1374
1375	/// Width in bits required to store all the negative
1376	/// enumerators of this enum.
1377	uint64_t NumNegativeBits : `8`;
1378
1379	/// True if this tag declaration is a scoped enumeration. Only
1380	/// possible in C++11 mode.
1381	uint64_t IsScoped : `1`;
1382
1383	/// If this tag declaration is a scoped enum,
1384	/// then this is true if the scoped enum was declared using the class
1385	/// tag, false if it was declared with the struct tag. No meaning is
1386	/// associated if this tag declaration is not a scoped enum.
1387	uint64_t IsScopedUsingClassTag : `1`;
1388
1389	/// True if this is an enumeration with fixed underlying type. Only
1390	/// possible in C++11, Microsoft extensions, or Objective C mode.
1391	uint64_t IsFixed : `1`;
1392
1393	/// True if a valid hash is stored in ODRHash.
1394	uint64_t HasODRHash : `1`;
1395	};
1396
1397	/// Number of non-inherited bits in EnumDeclBitfields.
1398	enum { NumEnumDeclBits = `20` };
1399
1400	/// Stores the bits used by RecordDecl.
1401	/// If modified NumRecordDeclBits and the accessor
1402	/// methods in RecordDecl should be updated appropriately.
1403	class RecordDeclBitfields {
1404	friend class RecordDecl;
1405	/// For the bits in DeclContextBitfields.
1406	uint64_t : NumDeclContextBits;
1407	/// For the bits in TagDeclBitfields.
1408	uint64_t : NumTagDeclBits;
1409
1410	/// This is true if this struct ends with a flexible
1411	/// array member (e.g. int X[]) or if this union contains a struct that does.
1412	/// If so, this cannot be contained in arrays or other structs as a member.
1413	uint64_t HasFlexibleArrayMember : `1`;
1414
1415	/// Whether this is the type of an anonymous struct or union.
1416	uint64_t AnonymousStructOrUnion : `1`;
1417
1418	/// This is true if this struct has at least one member
1419	/// containing an Objective-C object pointer type.
1420	uint64_t HasObjectMember : `1`;
1421
1422	/// This is true if struct has at least one member of
1423	/// 'volatile' type.
1424	uint64_t HasVolatileMember : `1`;
1425
1426	/// Whether the field declarations of this record have been loaded
1427	/// from external storage. To avoid unnecessary deserialization of
1428	/// methods/nested types we allow deserialization of just the fields
1429	/// when needed.
1430	mutable uint64_t LoadedFieldsFromExternalStorage : `1`;
1431
1432	/// Basic properties of non-trivial C structs.
1433	uint64_t NonTrivialToPrimitiveDefaultInitialize : `1`;
1434	uint64_t NonTrivialToPrimitiveCopy : `1`;
1435	uint64_t NonTrivialToPrimitiveDestroy : `1`;
1436
1437	/// Indicates whether this struct is destroyed in the callee.
1438	uint64_t ParamDestroyedInCallee : `1`;
1439
1440	/// Represents the way this type is passed to a function.
1441	uint64_t ArgPassingRestrictions : `2`;
1442	};
1443
1444	/// Number of non-inherited bits in RecordDeclBitfields.
1445	enum { NumRecordDeclBits = `11` };
1446
1447	/// Stores the bits used by OMPDeclareReductionDecl.
1448	/// If modified NumOMPDeclareReductionDeclBits and the accessor
1449	/// methods in OMPDeclareReductionDecl should be updated appropriately.
1450	class OMPDeclareReductionDeclBitfields {
1451	friend class OMPDeclareReductionDecl;
1452	/// For the bits in DeclContextBitfields
1453	uint64_t : NumDeclContextBits;
1454
1455	/// Kind of initializer,
1456	/// function call or omp_priv<init_expr> initializtion.
1457	uint64_t InitializerKind : `2`;
1458	};
1459
1460	/// Number of non-inherited bits in OMPDeclareReductionDeclBitfields.
1461	enum { NumOMPDeclareReductionDeclBits = `2` };
1462
1463	/// Stores the bits used by FunctionDecl.
1464	/// If modified NumFunctionDeclBits and the accessor
1465	/// methods in FunctionDecl and CXXDeductionGuideDecl
1466	/// (for IsCopyDeductionCandidate) should be updated appropriately.
1467	class FunctionDeclBitfields {
1468	friend class FunctionDecl;
1469	/// For IsCopyDeductionCandidate
1470	friend class CXXDeductionGuideDecl;
1471	/// For the bits in DeclContextBitfields.
1472	uint64_t : NumDeclContextBits;
1473
1474	uint64_t SClass : `3`;
1475	uint64_t IsInline : `1`;
1476	uint64_t IsInlineSpecified : `1`;
1477
1478	/// This is shared by CXXConstructorDecl,
1479	/// CXXConversionDecl, and CXXDeductionGuideDecl.
1480	uint64_t IsExplicitSpecified : `1`;
1481
1482	uint64_t IsVirtualAsWritten : `1`;
1483	uint64_t IsPure : `1`;
1484	uint64_t HasInheritedPrototype : `1`;
1485	uint64_t HasWrittenPrototype : `1`;
1486	uint64_t IsDeleted : `1`;
1487	/// Used by CXXMethodDecl
1488	uint64_t IsTrivial : `1`;
1489
1490	/// This flag indicates whether this function is trivial for the purpose of
1491	/// calls. This is meaningful only when this function is a copy/move
1492	/// constructor or a destructor.
1493	uint64_t IsTrivialForCall : `1`;
1494
1495	/// Used by CXXMethodDecl
1496	uint64_t IsDefaulted : `1`;
1497	/// Used by CXXMethodDecl
1498	uint64_t IsExplicitlyDefaulted : `1`;
1499	uint64_t HasImplicitReturnZero : `1`;
1500	uint64_t IsLateTemplateParsed : `1`;
1501	uint64_t IsConstexpr : `1`;
1502	uint64_t InstantiationIsPending : `1`;
1503
1504	/// Indicates if the function uses __try.
1505	uint64_t UsesSEHTry : `1`;
1506
1507	/// Indicates if the function was a definition
1508	/// but its body was skipped.
1509	uint64_t HasSkippedBody : `1`;
1510
1511	/// Indicates if the function declaration will
1512	/// have a body, once we're done parsing it.
1513	uint64_t WillHaveBody : `1`;
1514
1515	/// Indicates that this function is a multiversioned
1516	/// function using attribute 'target'.
1517	uint64_t IsMultiVersion : `1`;
1518
1519	/// [C++17] Only used by CXXDeductionGuideDecl. Indicates that
1520	/// the Deduction Guide is the implicitly generated 'copy
1521	/// deduction candidate' (is used during overload resolution).
1522	uint64_t IsCopyDeductionCandidate : `1`;
1523
1524	/// Store the ODRHash after first calculation.
1525	uint64_t HasODRHash : `1`;
1526	};
1527
1528	/// Number of non-inherited bits in FunctionDeclBitfields.
1529	enum { NumFunctionDeclBits = `25` };
1530
1531	/// Stores the bits used by CXXConstructorDecl. If modified
1532	/// NumCXXConstructorDeclBits and the accessor
1533	/// methods in CXXConstructorDecl should be updated appropriately.
1534	class CXXConstructorDeclBitfields {
1535	friend class CXXConstructorDecl;
1536	/// For the bits in DeclContextBitfields.
1537	uint64_t : NumDeclContextBits;
1538	/// For the bits in FunctionDeclBitfields.
1539	uint64_t : NumFunctionDeclBits;
1540
1541	/// 25 bits to fit in the remaining availible space.
1542	/// Note that this makes CXXConstructorDeclBitfields take
1543	/// exactly 64 bits and thus the width of NumCtorInitializers
1544	/// will need to be shrunk if some bit is added to NumDeclContextBitfields,
1545	/// NumFunctionDeclBitfields or CXXConstructorDeclBitfields.
1546	uint64_t NumCtorInitializers : `25`;
1547	uint64_t IsInheritingConstructor : `1`;
1548	};
1549
1550	/// Number of non-inherited bits in CXXConstructorDeclBitfields.
1551	enum { NumCXXConstructorDeclBits = `26` };
1552
1553	/// Stores the bits used by ObjCMethodDecl.
1554	/// If modified NumObjCMethodDeclBits and the accessor
1555	/// methods in ObjCMethodDecl should be updated appropriately.
1556	class ObjCMethodDeclBitfields {
1557	friend class ObjCMethodDecl;
1558
1559	/// For the bits in DeclContextBitfields.
1560	uint64_t : NumDeclContextBits;
1561
1562	/// The conventional meaning of this method; an ObjCMethodFamily.
1563	/// This is not serialized; instead, it is computed on demand and
1564	/// cached.
1565	mutable uint64_t Family : ObjCMethodFamilyBitWidth;
1566
1567	/// instance (true) or class (false) method.
1568	uint64_t IsInstance : `1`;
1569	uint64_t IsVariadic : `1`;
1570
1571	/// True if this method is the getter or setter for an explicit property.
1572	uint64_t IsPropertyAccessor : `1`;
1573
1574	/// Method has a definition.
1575	uint64_t IsDefined : `1`;
1576
1577	/// Method redeclaration in the same interface.
1578	uint64_t IsRedeclaration : `1`;
1579
1580	/// Is redeclared in the same interface.
1581	mutable uint64_t HasRedeclaration : `1`;
1582
1583	/// \@required/\@optional
1584	uint64_t DeclImplementation : `2`;
1585
1586	/// in, inout, etc.
1587	uint64_t objcDeclQualifier : `7`;
1588
1589	/// Indicates whether this method has a related result type.
1590	uint64_t RelatedResultType : `1`;
1591
1592	/// Whether the locations of the selector identifiers are in a
1593	/// "standard" position, a enum SelectorLocationsKind.
1594	uint64_t SelLocsKind : `2`;
1595
1596	/// Whether this method overrides any other in the class hierarchy.
1597	///
1598	/// A method is said to override any method in the class's
1599	/// base classes, its protocols, or its categories' protocols, that has
1600	/// the same selector and is of the same kind (class or instance).
1601	/// A method in an implementation is not considered as overriding the same
1602	/// method in the interface or its categories.
1603	uint64_t IsOverriding : `1`;
1604
1605	/// Indicates if the method was a definition but its body was skipped.
1606	uint64_t HasSkippedBody : `1`;
1607	};
1608
1609	/// Number of non-inherited bits in ObjCMethodDeclBitfields.
1610	enum { NumObjCMethodDeclBits = `24` };
1611
1612	/// Stores the bits used by ObjCContainerDecl.
1613	/// If modified NumObjCContainerDeclBits and the accessor
1614	/// methods in ObjCContainerDecl should be updated appropriately.
1615	class ObjCContainerDeclBitfields {
1616	friend class ObjCContainerDecl;
1617	/// For the bits in DeclContextBitfields
1618	uint32_t : NumDeclContextBits;
1619
1620	// Not a bitfield but this saves space.
1621	// Note that ObjCContainerDeclBitfields is full.
1622	SourceLocation AtStart;
1623	};
1624
1625	/// Number of non-inherited bits in ObjCContainerDeclBitfields.
1626	/// Note that here we rely on the fact that SourceLocation is 32 bits
1627	/// wide. We check this with the static_assert in the ctor of DeclContext.
1628	enum { NumObjCContainerDeclBits = `64` - NumDeclContextBits };
1629
1630	/// Stores the bits used by LinkageSpecDecl.
1631	/// If modified NumLinkageSpecDeclBits and the accessor
1632	/// methods in LinkageSpecDecl should be updated appropriately.
1633	class LinkageSpecDeclBitfields {
1634	friend class LinkageSpecDecl;
1635	/// For the bits in DeclContextBitfields.
1636	uint64_t : NumDeclContextBits;
1637
1638	/// The language for this linkage specification with values
1639	/// in the enum LinkageSpecDecl::LanguageIDs.
1640	uint64_t Language : `3`;
1641
1642	/// True if this linkage spec has braces.
1643	/// This is needed so that hasBraces() returns the correct result while the
1644	/// linkage spec body is being parsed. Once RBraceLoc has been set this is
1645	/// not used, so it doesn't need to be serialized.
1646	uint64_t HasBraces : `1`;
1647	};
1648
1649	/// Number of non-inherited bits in LinkageSpecDeclBitfields.
1650	enum { NumLinkageSpecDeclBits = `4` };
1651
1652	/// Stores the bits used by BlockDecl.
1653	/// If modified NumBlockDeclBits and the accessor
1654	/// methods in BlockDecl should be updated appropriately.
1655	class BlockDeclBitfields {
1656	friend class BlockDecl;
1657	/// For the bits in DeclContextBitfields.
1658	uint64_t : NumDeclContextBits;
1659
1660	uint64_t IsVariadic : `1`;
1661	uint64_t CapturesCXXThis : `1`;
1662	uint64_t BlockMissingReturnType : `1`;
1663	uint64_t IsConversionFromLambda : `1`;
1664
1665	/// A bit that indicates this block is passed directly to a function as a
1666	/// non-escaping parameter.
1667	uint64_t DoesNotEscape : `1`;
1668	};
1669
1670	/// Number of non-inherited bits in BlockDeclBitfields.
1671	enum { NumBlockDeclBits = `5` };
1672
1673	/// Pointer to the data structure used to lookup declarations
1674	/// within this context (or a DependentStoredDeclsMap if this is a
1675	/// dependent context). We maintain the invariant that, if the map
1676	/// contains an entry for a DeclarationName (and we haven't lazily
1677	/// omitted anything), then it contains all relevant entries for that
1678	/// name (modulo the hasExternalDecls() flag).
1679	mutable StoredDeclsMap LookupPtr = nullptr*;
1680
1681	protected:
1682	/// This anonymous union stores the bits belonging to DeclContext and classes
1683	/// deriving from it. The goal is to use otherwise wasted
1684	/// space in DeclContext to store data belonging to derived classes.
1685	/// The space saved is especially significient when pointers are aligned
1686	/// to 8 bytes. In this case due to alignment requirements we have a
1687	/// little less than 8 bytes free in DeclContext which we can use.
1688	/// We check that none of the classes in this union is larger than
1689	/// 8 bytes with static_asserts in the ctor of DeclContext.
1690	union {
1691	DeclContextBitfields DeclContextBits;
1692	TagDeclBitfields TagDeclBits;
1693	EnumDeclBitfields EnumDeclBits;
1694	RecordDeclBitfields RecordDeclBits;
1695	OMPDeclareReductionDeclBitfields OMPDeclareReductionDeclBits;
1696	FunctionDeclBitfields FunctionDeclBits;
1697	CXXConstructorDeclBitfields CXXConstructorDeclBits;
1698	ObjCMethodDeclBitfields ObjCMethodDeclBits;
1699	ObjCContainerDeclBitfields ObjCContainerDeclBits;
1700	LinkageSpecDeclBitfields LinkageSpecDeclBits;
1701	BlockDeclBitfields BlockDeclBits;
1702
1703	static_assert(sizeof(DeclContextBitfields) <= `8`,
1704	"DeclContextBitfields is larger than 8 bytes!");
1705	static_assert(sizeof(TagDeclBitfields) <= `8`,
1706	"TagDeclBitfields is larger than 8 bytes!");
1707	static_assert(sizeof(EnumDeclBitfields) <= `8`,
1708	"EnumDeclBitfields is larger than 8 bytes!");
1709	static_assert(sizeof(RecordDeclBitfields) <= `8`,
1710	"RecordDeclBitfields is larger than 8 bytes!");
1711	static_assert(sizeof(OMPDeclareReductionDeclBitfields) <= `8`,
1712	"OMPDeclareReductionDeclBitfields is larger than 8 bytes!");
1713	static_assert(sizeof(FunctionDeclBitfields) <= `8`,
1714	"FunctionDeclBitfields is larger than 8 bytes!");
1715	static_assert(sizeof(CXXConstructorDeclBitfields) <= `8`,
1716	"CXXConstructorDeclBitfields is larger than 8 bytes!");
1717	static_assert(sizeof(ObjCMethodDeclBitfields) <= `8`,
1718	"ObjCMethodDeclBitfields is larger than 8 bytes!");
1719	static_assert(sizeof(ObjCContainerDeclBitfields) <= `8`,
1720	"ObjCContainerDeclBitfields is larger than 8 bytes!");
1721	static_assert(sizeof(LinkageSpecDeclBitfields) <= `8`,
1722	"LinkageSpecDeclBitfields is larger than 8 bytes!");
1723	static_assert(sizeof(BlockDeclBitfields) <= `8`,
1724	"BlockDeclBitfields is larger than 8 bytes!");
1725	};
1726
1727	/// FirstDecl - The first declaration stored within this declaration
1728	/// context.
1729	mutable Decl FirstDecl = nullptr*;
1730
1731	/// LastDecl - The last declaration stored within this declaration
1732	/// context. FIXME: We could probably cache this value somewhere
1733	/// outside of the DeclContext, to reduce the size of DeclContext by
1734	/// another pointer.
1735	mutable Decl LastDecl = nullptr*;
1736
1737	/// Build up a chain of declarations.
1738	///
1739	/// \returns the first/last pair of declarations.
1740	static std::pair<Decl , Decl >
1741	BuildDeclChain(ArrayRef<Decl> Decls, bool* FieldsAlreadyLoaded);
1742
1743	DeclContext(Decl::Kind K);
1744
1745	public:
1746	~DeclContext();
1747
1748	Decl::Kind getDeclKind() const {
1749	return static_cast<Decl::Kind>(DeclContextBits.DeclKind);
1750	}
1751
1752	const char getDeclKindName() const*;
1753
1754	/// getParent - Returns the containing DeclContext.
1755	DeclContext *getParent() {
1756	return cast<Decl>(this)->getDeclContext();
1757	}
1758	const DeclContext getParent() const* {
1759	return const_cast<DeclContext>(this*)->getParent();
1760	}
1761
1762	/// getLexicalParent - Returns the containing lexical DeclContext. May be
1763	/// different from getParent, e.g.:
1764	///
1765	/// namespace A {
1766	/// struct S;
1767	/// }
1768	/// struct A::S {}; // getParent() == namespace 'A'
1769	/// // getLexicalParent() == translation unit
1770	///
1771	DeclContext *getLexicalParent() {
1772	return cast<Decl>(this)->getLexicalDeclContext();
1773	}
1774	const DeclContext getLexicalParent() const* {
1775	return const_cast<DeclContext>(this*)->getLexicalParent();
1776	}
1777
1778	DeclContext *getLookupParent();
1779
1780	const DeclContext getLookupParent() const* {
1781	return const_cast<DeclContext>(this*)->getLookupParent();
1782	}
1783
1784	ASTContext &getParentASTContext() const {
1785	return cast<Decl>(this)->getASTContext();
1786	}
1787
1788	bool isClosure() const { return getDeclKind() == Decl::Block; }
1789
1790	bool isObjCContainer() const {
1791	switch (getDeclKind()) {
1792	case Decl::ObjCCategory:
1793	case Decl::ObjCCategoryImpl:
1794	case Decl::ObjCImplementation:
1795	case Decl::ObjCInterface:
1796	case Decl::ObjCProtocol:
1797	return true;
1798	default:
1799	return false;
1800	}
1801	}
1802
1803	bool isFunctionOrMethod() const {
1804	switch (getDeclKind()) {
1805	case Decl::Block:
1806	case Decl::Captured:
1807	case Decl::ObjCMethod:
1808	return true;
1809	default:
1810	return getDeclKind() >= Decl::firstFunction &&
1811	getDeclKind() <= Decl::lastFunction;
1812	}
1813	}
1814
1815	/// Test whether the context supports looking up names.
1816	bool isLookupContext() const {
1817	return !isFunctionOrMethod() && getDeclKind() != Decl::LinkageSpec &&
1818	getDeclKind() != Decl::Export;
1819	}
1820
1821	bool isFileContext() const {
1822	return getDeclKind() == Decl::TranslationUnit \|\|
1823	getDeclKind() == Decl::Namespace;
1824	}
1825
1826	bool isTranslationUnit() const {
1827	return getDeclKind() == Decl::TranslationUnit;
1828	}
1829
1830	bool isRecord() const {
1831	return getDeclKind() >= Decl::firstRecord &&
1832	getDeclKind() <= Decl::lastRecord;
1833	}
1834
1835	bool isNamespace() const { return getDeclKind() == Decl::Namespace; }
1836
1837	bool isStdNamespace() const;
1838
1839	bool isInlineNamespace() const;
1840
1841	/// Determines whether this context is dependent on a
1842	/// template parameter.
1843	bool isDependentContext() const;
1844
1845	/// isTransparentContext - Determines whether this context is a
1846	/// "transparent" context, meaning that the members declared in this
1847	/// context are semantically declared in the nearest enclosing
1848	/// non-transparent (opaque) context but are lexically declared in
1849	/// this context. For example, consider the enumerators of an
1850	/// enumeration type:
1851	/// @code
1852	/// enum E {
1853	/// Val1
1854	/// };
1855	/// @endcode
1856	/// Here, E is a transparent context, so its enumerator (Val1) will
1857	/// appear (semantically) that it is in the same context of E.
1858	/// Examples of transparent contexts include: enumerations (except for
1859	/// C++0x scoped enums), and C++ linkage specifications.
1860	bool isTransparentContext() const;
1861
1862	/// Determines whether this context or some of its ancestors is a
1863	/// linkage specification context that specifies C linkage.
1864	bool isExternCContext() const;
1865
1866	/// Retrieve the nearest enclosing C linkage specification context.
1867	const LinkageSpecDecl getExternCContext() const*;
1868
1869	/// Determines whether this context or some of its ancestors is a
1870	/// linkage specification context that specifies C++ linkage.
1871	bool isExternCXXContext() const;
1872
1873	/// Determine whether this declaration context is equivalent
1874	/// to the declaration context DC.
1875	bool Equals(const DeclContext DC) const* {
1876	return DC && this->getPrimaryContext() == DC->getPrimaryContext();
1877	}
1878
1879	/// Determine whether this declaration context encloses the
1880	/// declaration context DC.
1881	bool Encloses(const DeclContext DC) const*;
1882
1883	/// Find the nearest non-closure ancestor of this context,
1884	/// i.e. the innermost semantic parent of this context which is not
1885	/// a closure. A context may be its own non-closure ancestor.
1886	Decl *getNonClosureAncestor();
1887	const Decl getNonClosureAncestor() const* {
1888	return const_cast<DeclContext>(this*)->getNonClosureAncestor();
1889	}
1890
1891	/// getPrimaryContext - There may be many different
1892	/// declarations of the same entity (including forward declarations
1893	/// of classes, multiple definitions of namespaces, etc.), each with
1894	/// a different set of declarations. This routine returns the
1895	/// "primary" DeclContext structure, which will contain the
1896	/// information needed to perform name lookup into this context.
1897	DeclContext *getPrimaryContext();
1898	const DeclContext getPrimaryContext() const* {
1899	return const_cast<DeclContext>(this*)->getPrimaryContext();
1900	}
1901
1902	/// getRedeclContext - Retrieve the context in which an entity conflicts with
1903	/// other entities of the same name, or where it is a redeclaration if the
1904	/// two entities are compatible. This skips through transparent contexts.
1905	DeclContext *getRedeclContext();
1906	const DeclContext getRedeclContext() const* {
1907	return const_cast<DeclContext >(this*)->getRedeclContext();
1908	}
1909
1910	/// Retrieve the nearest enclosing namespace context.
1911	DeclContext *getEnclosingNamespaceContext();
1912	const DeclContext getEnclosingNamespaceContext() const* {
1913	return const_cast<DeclContext >(this*)->getEnclosingNamespaceContext();
1914	}
1915
1916	/// Retrieve the outermost lexically enclosing record context.
1917	RecordDecl *getOuterLexicalRecordContext();
1918	const RecordDecl getOuterLexicalRecordContext() const* {
1919	return const_cast<DeclContext >(this*)->getOuterLexicalRecordContext();
1920	}
1921
1922	/// Test if this context is part of the enclosing namespace set of
1923	/// the context NS, as defined in C++0x [namespace.def]p9. If either context
1924	/// isn't a namespace, this is equivalent to Equals().
1925	///
1926	/// The enclosing namespace set of a namespace is the namespace and, if it is
1927	/// inline, its enclosing namespace, recursively.
1928	bool InEnclosingNamespaceSetOf(const DeclContext NS) const*;
1929
1930	/// Collects all of the declaration contexts that are semantically
1931	/// connected to this declaration context.
1932	///
1933	/// For declaration contexts that have multiple semantically connected but
1934	/// syntactically distinct contexts, such as C++ namespaces, this routine
1935	/// retrieves the complete set of such declaration contexts in source order.
1936	/// For example, given:
1937	///
1938	/// \code
1939	/// namespace N {
1940	/// int x;
1941	/// }
1942	/// namespace N {
1943	/// int y;
1944	/// }
1945	/// \endcode
1946	///
1947	/// The \c Contexts parameter will contain both definitions of N.
1948	///
1949	/// \param Contexts Will be cleared and set to the set of declaration
1950	/// contexts that are semanticaly connected to this declaration context,
1951	/// in source order, including this context (which may be the only result,
1952	/// for non-namespace contexts).
1953	void collectAllContexts(SmallVectorImpl<DeclContext *> &Contexts);
1954
1955	/// decl_iterator - Iterates through the declarations stored
1956	/// within this context.
1957	class decl_iterator {
1958	/// Current - The current declaration.
1959	Decl Current = nullptr*;
1960
1961	public:
1962	using value_type = Decl *;
1963	using reference = const value_type &;
1964	using pointer = const value_type *;
1965	using iterator_category = std::forward_iterator_tag;
1966	using difference_type = std::ptrdiff_t;
1967
1968	decl_iterator() = default;
1969	explicit decl_iterator(Decl *C) : Current(C) {}
1970
1971	reference operator() const* { return Current; }
1972
1973	// This doesn't meet the iterator requirements, but it's convenient
1974	value_type operator->() const { return Current; }
1975
1976	decl_iterator& operator++() {
1977	Current = Current->getNextDeclInContext();
1978	return *this;
1979	}
1980
1981	decl_iterator operator++(int) {
1982	decl_iterator tmp(*this);
1983	++(*this);
1984	return tmp;
1985	}
1986
1987	friend bool operator==(decl_iterator x, decl_iterator y) {
1988	return x.Current == y.Current;
1989	}
1990
1991	friend bool operator!=(decl_iterator x, decl_iterator y) {
1992	return x.Current != y.Current;
1993	}
1994	};
1995
1996	using decl_range = llvm::iterator_range<decl_iterator>;
1997
1998	/// decls_begin/decls_end - Iterate over the declarations stored in
1999	/// this context.
2000	decl_range decls() const { return decl_range (decls_begin(), decls_end()); }
2001	decl_iterator decls_begin() const;
2002	decl_iterator decls_end() const { return decl_iterator (); }
2003	bool decls_empty() const;
2004
2005	/// noload_decls_begin/end - Iterate over the declarations stored in this
2006	/// context that are currently loaded; don't attempt to retrieve anything
2007	/// from an external source.
2008	decl_range noload_decls() const {
2009	return decl_range (noload_decls_begin(), noload_decls_end());
2010	}
2011	decl_iterator noload_decls_begin() const { return decl_iterator (FirstDecl); }
2012	decl_iterator noload_decls_end() const { return decl_iterator (); }
2013
2014	/// specific_decl_iterator - Iterates over a subrange of
2015	/// declarations stored in a DeclContext, providing only those that
2016	/// are of type SpecificDecl (or a class derived from it). This
2017	/// iterator is used, for example, to provide iteration over just
2018	/// the fields within a RecordDecl (with SpecificDecl = FieldDecl).
2019	template<typename SpecificDecl>
2020	class specific_decl_iterator {
2021	/// Current - The current, underlying declaration iterator, which
2022	/// will either be NULL or will point to a declaration of
2023	/// type SpecificDecl.
2024	DeclContext::decl_iterator Current;
2025
2026	/// SkipToNextDecl - Advances the current position up to the next
2027	/// declaration of type SpecificDecl that also meets the criteria
2028	/// required by Acceptable.
2029	void SkipToNextDecl() {
2030	while (Current && !isa<SpecificDecl>(Current))
2031	++Current;
2032	}
2033
2034	public:
2035	using value_type = SpecificDecl *;
2036	// TODO: Add reference and pointer types (with some appropriate proxy type)
2037	// if we ever have a need for them.
2038	using reference = void;
2039	using pointer = void;
2040	using difference_type =
2041	std::iterator_traits<DeclContext::decl_iterator>::difference_type;
2042	using iterator_category = std::forward_iterator_tag;
2043
2044	specific_decl_iterator() = default;
2045
2046	/// specific_decl_iterator - Construct a new iterator over a
2047	/// subset of the declarations the range [C,
2048	/// end-of-declarations). If A is non-NULL, it is a pointer to a
2049	/// member function of SpecificDecl that should return true for
2050	/// all of the SpecificDecl instances that will be in the subset
2051	/// of iterators. For example, if you want Objective-C instance
2052	/// methods, SpecificDecl will be ObjCMethodDecl and A will be
2053	/// &ObjCMethodDecl::isInstanceMethod.
2054	explicit specific_decl_iterator(DeclContext::decl_iterator C) : Current (C) {
2055	SkipToNextDecl();
2056	}
2057
2058	value_type operator() const* { return cast<SpecificDecl>(*Current); }
2059
2060	// This doesn't meet the iterator requirements, but it's convenient
2061	value_type operator->() const { return **this; }
2062
2063	specific_decl_iterator& operator++() {
2064	++Current;
2065	SkipToNextDecl();
2066	return *this;
2067	}
2068
2069	specific_decl_iterator operator++(int) {
2070	specific_decl_iterator tmp(*this);
2071	++(*this);
2072	return tmp;
2073	}
2074
2075	friend bool operator==(const specific_decl_iterator& x,
2076	const specific_decl_iterator& y) {
2077	return x.Current == y.Current;
2078	}
2079
2080	friend bool operator!=(const specific_decl_iterator& x,
2081	const specific_decl_iterator& y) {
2082	return x.Current != y.Current;
2083	}
2084	};
2085
2086	/// Iterates over a filtered subrange of declarations stored
2087	/// in a DeclContext.
2088	///
2089	/// This iterator visits only those declarations that are of type
2090	/// SpecificDecl (or a class derived from it) and that meet some
2091	/// additional run-time criteria. This iterator is used, for
2092	/// example, to provide access to the instance methods within an
2093	/// Objective-C interface (with SpecificDecl = ObjCMethodDecl and
2094	/// Acceptable = ObjCMethodDecl::isInstanceMethod).
2095	template<typename SpecificDecl, bool (SpecificDecl::Acceptable)() const*>
2096	class filtered_decl_iterator {
2097	/// Current - The current, underlying declaration iterator, which
2098	/// will either be NULL or will point to a declaration of
2099	/// type SpecificDecl.
2100	DeclContext::decl_iterator Current;
2101
2102	/// SkipToNextDecl - Advances the current position up to the next
2103	/// declaration of type SpecificDecl that also meets the criteria
2104	/// required by Acceptable.
2105	void SkipToNextDecl() {
2106	while (*Current &&
2107	(!isa<SpecificDecl>(*Current) \|\|
2108	(Acceptable && !(cast<SpecificDecl>(Current)->Acceptable)())))
2109	++Current;
2110	}
2111
2112	public:
2113	using value_type = SpecificDecl *;
2114	// TODO: Add reference and pointer types (with some appropriate proxy type)
2115	// if we ever have a need for them.
2116	using reference = void;
2117	using pointer = void;
2118	using difference_type =
2119	std::iterator_traits<DeclContext::decl_iterator>::difference_type;
2120	using iterator_category = std::forward_iterator_tag;
2121
2122	filtered_decl_iterator() = default;
2123
2124	/// filtered_decl_iterator - Construct a new iterator over a
2125	/// subset of the declarations the range [C,
2126	/// end-of-declarations). If A is non-NULL, it is a pointer to a
2127	/// member function of SpecificDecl that should return true for
2128	/// all of the SpecificDecl instances that will be in the subset
2129	/// of iterators. For example, if you want Objective-C instance
2130	/// methods, SpecificDecl will be ObjCMethodDecl and A will be
2131	/// &ObjCMethodDecl::isInstanceMethod.
2132	explicit filtered_decl_iterator(DeclContext::decl_iterator C) : Current (C) {
2133	SkipToNextDecl();
2134	}
2135
2136	value_type operator() const* { return cast<SpecificDecl>(*Current); }
2137	value_type operator->() const { return cast<SpecificDecl>(*Current); }
2138
2139	filtered_decl_iterator& operator++() {
2140	++Current;
2141	SkipToNextDecl();
2142	return *this;
2143	}
2144
2145	filtered_decl_iterator operator++(int) {
2146	filtered_decl_iterator tmp(*this);
2147	++(*this);
2148	return tmp;
2149	}
2150
2151	friend bool operator==(const filtered_decl_iterator& x,
2152	const filtered_decl_iterator& y) {
2153	return x.Current == y.Current;
2154	}
2155
2156	friend bool operator!=(const filtered_decl_iterator& x,
2157	const filtered_decl_iterator& y) {
2158	return x.Current != y.Current;
2159	}
2160	};
2161
2162	/// Add the declaration D into this context.
2163	///
2164	/// This routine should be invoked when the declaration D has first
2165	/// been declared, to place D into the context where it was
2166	/// (lexically) defined. Every declaration must be added to one
2167	/// (and only one!) context, where it can be visited via
2168	/// [decls_begin(), decls_end()). Once a declaration has been added
2169	/// to its lexical context, the corresponding DeclContext owns the
2170	/// declaration.
2171	///
2172	/// If D is also a NamedDecl, it will be made visible within its
2173	/// semantic context via makeDeclVisibleInContext.
2174	void addDecl(Decl *D);
2175
2176	/// Add the declaration D into this context, but suppress
2177	/// searches for external declarations with the same name.
2178	///
2179	/// Although analogous in function to addDecl, this removes an
2180	/// important check. This is only useful if the Decl is being
2181	/// added in response to an external search; in all other cases,
2182	/// addDecl() is the right function to use.
2183	/// See the ASTImporter for use cases.
2184	void addDeclInternal(Decl *D);
2185
2186	/// Add the declaration D to this context without modifying
2187	/// any lookup tables.
2188	///
2189	/// This is useful for some operations in dependent contexts where
2190	/// the semantic context might not be dependent; this basically
2191	/// only happens with friends.
2192	void addHiddenDecl(Decl *D);
2193
2194	/// Removes a declaration from this context.
2195	void removeDecl(Decl *D);
2196
2197	/// Checks whether a declaration is in this context.
2198	bool containsDecl(Decl D) const*;
2199
2200	/// Checks whether a declaration is in this context.
2201	/// This also loads the Decls from the external source before the check.
2202	bool containsDeclAndLoad(Decl D) const*;
2203
2204	using lookup_result = DeclContextLookupResult;
2205	using lookup_iterator = lookup_result::iterator;
2206
2207	/// lookup - Find the declarations (if any) with the given Name in
2208	/// this context. Returns a range of iterators that contains all of
2209	/// the declarations with this name, with object, function, member,
2210	/// and enumerator names preceding any tag name. Note that this
2211	/// routine will not look into parent contexts.
2212	lookup_result lookup(DeclarationName Name) const;
2213
2214	/// Find the declarations with the given name that are visible
2215	/// within this context; don't attempt to retrieve anything from an
2216	/// external source.
2217	lookup_result noload_lookup(DeclarationName Name);
2218
2219	/// A simplistic name lookup mechanism that performs name lookup
2220	/// into this declaration context without consulting the external source.
2221	///
2222	/// This function should almost never be used, because it subverts the
2223	/// usual relationship between a DeclContext and the external source.
2224	/// See the ASTImporter for the (few, but important) use cases.
2225	///
2226	/// FIXME: This is very inefficient; replace uses of it with uses of
2227	/// noload_lookup.
2228	void localUncachedLookup(DeclarationName Name,
2229	SmallVectorImpl<NamedDecl *> &Results);
2230
2231	/// Makes a declaration visible within this context.
2232	///
2233	/// This routine makes the declaration D visible to name lookup
2234	/// within this context and, if this is a transparent context,
2235	/// within its parent contexts up to the first enclosing
2236	/// non-transparent context. Making a declaration visible within a
2237	/// context does not transfer ownership of a declaration, and a
2238	/// declaration can be visible in many contexts that aren't its
2239	/// lexical context.
2240	///
2241	/// If D is a redeclaration of an existing declaration that is
2242	/// visible from this context, as determined by
2243	/// NamedDecl::declarationReplaces, the previous declaration will be
2244	/// replaced with D.
2245	void makeDeclVisibleInContext(NamedDecl *D);
2246
2247	/// all_lookups_iterator - An iterator that provides a view over the results
2248	/// of looking up every possible name.
2249	class all_lookups_iterator;
2250
2251	using lookups_range = llvm::iterator_range<all_lookups_iterator>;
2252
2253	lookups_range lookups() const;
2254	// Like lookups(), but avoids loading external declarations.
2255	// If PreserveInternalState, avoids building lookup data structures too.
2256	lookups_range noload_lookups(bool PreserveInternalState) const;
2257
2258	/// Iterators over all possible lookups within this context.
2259	all_lookups_iterator lookups_begin() const;
2260	all_lookups_iterator lookups_end() const;
2261
2262	/// Iterators over all possible lookups within this context that are
2263	/// currently loaded; don't attempt to retrieve anything from an external
2264	/// source.
2265	all_lookups_iterator noload_lookups_begin() const;
2266	all_lookups_iterator noload_lookups_end() const;
2267
2268	struct udir_iterator;
2269
2270	using udir_iterator_base =
2271	llvm::iterator_adaptor_base<udir_iterator, lookup_iterator,
2272	std::random_access_iterator_tag,
2273	UsingDirectiveDecl *>;
2274
2275	struct udir_iterator : udir_iterator_base {
2276	udir_iterator(lookup_iterator I) : udir_iterator_base (I) {}
2277
2278	UsingDirectiveDecl *operator() const*;
2279	};
2280
2281	using udir_range = llvm::iterator_range<udir_iterator>;
2282
2283	udir_range using_directives() const;
2284
2285	// These are all defined in DependentDiagnostic.h.
2286	class ddiag_iterator;
2287
2288	using ddiag_range = llvm::iterator_range<DeclContext::ddiag_iterator>;
2289
2290	inline ddiag_range ddiags() const;
2291
2292	// Low-level accessors
2293
2294	/// Mark that there are external lexical declarations that we need
2295	/// to include in our lookup table (and that are not available as external
2296	/// visible lookups). These extra lookup results will be found by walking
2297	/// the lexical declarations of this context. This should be used only if
2298	/// setHasExternalLexicalStorage() has been called on any decl context for
2299	/// which this is the primary context.
2300	void setMustBuildLookupTable() {
2301	assert(this == getPrimaryContext() &&
2302	"should only be called on primary context");
2303	DeclContextBits.HasLazyExternalLexicalLookups = true;
2304	}
2305
2306	/// Retrieve the internal representation of the lookup structure.
2307	/// This may omit some names if we are lazily building the structure.
2308	StoredDeclsMap getLookupPtr() const* { return LookupPtr; }
2309
2310	/// Ensure the lookup structure is fully-built and return it.
2311	StoredDeclsMap *buildLookup();
2312
2313	/// Whether this DeclContext has external storage containing
2314	/// additional declarations that are lexically in this context.
2315	bool hasExternalLexicalStorage() const {
2316	return DeclContextBits.ExternalLexicalStorage;
2317	}
2318
2319	/// State whether this DeclContext has external storage for
2320	/// declarations lexically in this context.
2321	void setHasExternalLexicalStorage(bool ES = true) const {
2322	DeclContextBits.ExternalLexicalStorage = ES;
2323	}
2324
2325	/// Whether this DeclContext has external storage containing
2326	/// additional declarations that are visible in this context.
2327	bool hasExternalVisibleStorage() const {
2328	return DeclContextBits.ExternalVisibleStorage;
2329	}
2330
2331	/// State whether this DeclContext has external storage for
2332	/// declarations visible in this context.
2333	void setHasExternalVisibleStorage(bool ES = true) const {
2334	DeclContextBits.ExternalVisibleStorage = ES;
2335	if (ES && LookupPtr)
2336	DeclContextBits.NeedToReconcileExternalVisibleStorage = true;
2337	}
2338
2339	/// Determine whether the given declaration is stored in the list of
2340	/// declarations lexically within this context.
2341	bool isDeclInLexicalTraversal(const Decl D) const* {
2342	return D && (D->NextInContextAndBits.getPointer() \|\| D == FirstDecl \|\|
2343	D == LastDecl);
2344	}
2345
2346	bool setUseQualifiedLookup(bool use = true) const {
2347	bool old_value = DeclContextBits.UseQualifiedLookup;
2348	DeclContextBits.UseQualifiedLookup = use;
2349	return old_value;
2350	}
2351
2352	bool shouldUseQualifiedLookup() const {
2353	return DeclContextBits.UseQualifiedLookup;
2354	}
2355
2356	static bool classof(const Decl *D);
2357	static bool classof(const DeclContext D) { return* true; }
2358
2359	void dumpDeclContext() const;
2360	void dumpLookups() const;
2361	void dumpLookups(llvm::raw_ostream &OS, bool DumpDecls = false,
2362	bool Deserialize = false) const;
2363
2364	private:
2365	/// Whether this declaration context has had externally visible
2366	/// storage added since the last lookup. In this case, \c LookupPtr's
2367	/// invariant may not hold and needs to be fixed before we perform
2368	/// another lookup.
2369	bool hasNeedToReconcileExternalVisibleStorage() const {
2370	return DeclContextBits.NeedToReconcileExternalVisibleStorage;
2371	}
2372
2373	/// State that this declaration context has had externally visible
2374	/// storage added since the last lookup. In this case, \c LookupPtr's
2375	/// invariant may not hold and needs to be fixed before we perform
2376	/// another lookup.
2377	void setNeedToReconcileExternalVisibleStorage(bool Need = true) const {
2378	DeclContextBits.NeedToReconcileExternalVisibleStorage = Need;
2379	}
2380
2381	/// If \c true, this context may have local lexical declarations
2382	/// that are missing from the lookup table.
2383	bool hasLazyLocalLexicalLookups() const {
2384	return DeclContextBits.HasLazyLocalLexicalLookups;
2385	}
2386
2387	/// If \c true, this context may have local lexical declarations
2388	/// that are missing from the lookup table.
2389	void setHasLazyLocalLexicalLookups(bool HasLLLL = true) const {
2390	DeclContextBits.HasLazyLocalLexicalLookups = HasLLLL;
2391	}
2392
2393	/// If \c true, the external source may have lexical declarations
2394	/// that are missing from the lookup table.
2395	bool hasLazyExternalLexicalLookups() const {
2396	return DeclContextBits.HasLazyExternalLexicalLookups;
2397	}
2398
2399	/// If \c true, the external source may have lexical declarations
2400	/// that are missing from the lookup table.
2401	void setHasLazyExternalLexicalLookups(bool HasLELL = true) const {
2402	DeclContextBits.HasLazyExternalLexicalLookups = HasLELL;
2403	}
2404
2405	void reconcileExternalVisibleStorage() const;
2406	bool LoadLexicalDeclsFromExternalStorage() const;
2407
2408	/// Makes a declaration visible within this context, but
2409	/// suppresses searches for external declarations with the same
2410	/// name.
2411	///
2412	/// Analogous to makeDeclVisibleInContext, but for the exclusive
2413	/// use of addDeclInternal().
2414	void makeDeclVisibleInContextInternal(NamedDecl *D);
2415
2416	StoredDeclsMap CreateStoredDeclsMap(ASTContext &C) const*;
2417
2418	void loadLazyLocalLexicalLookups();
2419	void buildLookupImpl(DeclContext DCtx, bool* Internal);
2420	void makeDeclVisibleInContextWithFlags(NamedDecl D, bool* Internal,
2421	bool Rediscoverable);
2422	void makeDeclVisibleInContextImpl(NamedDecl D, bool* Internal);
2423	};
2424
2425	inline bool Decl::isTemplateParameter() const {
2426	return getKind() == TemplateTypeParm \|\| getKind() == NonTypeTemplateParm \|\|
2427	getKind() == TemplateTemplateParm;
2428	}
2429
2430	// Specialization selected when ToTy is not a known subclass of DeclContext.
2431	template <class ToTy,
2432	bool IsKnownSubtype = ::std::is_base_of<DeclContext, ToTy>::value>
2433	struct cast_convert_decl_context {
2434	static const ToTy doit(const* DeclContext *Val) {
2435	return static_cast<const ToTy*>(Decl::castFromDeclContext(Val));
2436	}
2437
2438	static ToTy doit(DeclContext Val) {
2439	return static_cast<ToTy*>(Decl::castFromDeclContext(Val));
2440	}
2441	};
2442
2443	// Specialization selected when ToTy is a known subclass of DeclContext.
2444	template <class ToTy>
2445	struct cast_convert_decl_context<ToTy, true> {
2446	static const ToTy doit(const* DeclContext *Val) {
2447	return static_cast<const ToTy*>(Val);
2448	}
2449
2450	static ToTy doit(DeclContext Val) {
2451	return static_cast<ToTy*>(Val);
2452	}
2453	};
2454
2455	} // namespace clang
2456
2457	namespace llvm {
2458
2459	/// isa<T>(DeclContext)*
2460	template <typename To>
2461	struct isa_impl<To, ::clang::DeclContext> {
2462	static bool doit(const ::clang::DeclContext &Val) {
2463	return To::classofKind(Val.getDeclKind());
2464	}
2465	};
2466
2467	/// cast<T>(DeclContext)*
2468	template<class ToTy>
2469	struct cast_convert_val<ToTy,
2470	const ::clang::DeclContext,const ::clang::DeclContext> {
2471	static const ToTy &doit(const ::clang::DeclContext &Val) {
2472	return *::clang::cast_convert_decl_context<ToTy>::doit(&Val);
2473	}
2474	};
2475
2476	template<class ToTy>
2477	struct cast_convert_val<ToTy, ::clang::DeclContext, ::clang::DeclContext> {
2478	static ToTy &doit(::clang::DeclContext &Val) {
2479	return *::clang::cast_convert_decl_context<ToTy>::doit(&Val);
2480	}
2481	};
2482
2483	template<class ToTy>
2484	struct cast_convert_val<ToTy,
2485	const ::clang::DeclContext, const* ::clang::DeclContext*> {
2486	static const ToTy doit(const* ::clang::DeclContext *Val) {
2487	return ::clang::cast_convert_decl_context<ToTy>::doit(Val);
2488	}
2489	};
2490
2491	template<class ToTy>
2492	struct cast_convert_val<ToTy, ::clang::DeclContext, ::clang::DeclContext> {
2493	static ToTy doit(::clang::DeclContext Val) {
2494	return ::clang::cast_convert_decl_context<ToTy>::doit(Val);
2495	}
2496	};
2497
2498	/// Implement cast_convert_val for Decl -> DeclContext conversions.
2499	template<class FromTy>
2500	struct cast_convert_val< ::clang::DeclContext, FromTy, FromTy> {
2501	static ::clang::DeclContext &doit(const FromTy &Val) {
2502	return *FromTy::castToDeclContext(&Val);
2503	}
2504	};
2505
2506	template<class FromTy>
2507	struct cast_convert_val< ::clang::DeclContext, FromTy, FromTy> {
2508	static ::clang::DeclContext doit(const* FromTy *Val) {
2509	return FromTy::castToDeclContext(Val);
2510	}
2511	};
2512
2513	template<class FromTy>
2514	struct cast_convert_val< const ::clang::DeclContext, FromTy, FromTy> {
2515	static const ::clang::DeclContext &doit(const FromTy &Val) {
2516	return *FromTy::castToDeclContext(&Val);
2517	}
2518	};
2519
2520	template<class FromTy>
2521	struct cast_convert_val< const ::clang::DeclContext, FromTy, FromTy> {
2522	static const ::clang::DeclContext doit(const* FromTy *Val) {
2523	return FromTy::castToDeclContext(Val);
2524	}
2525	};
2526
2527	} // namespace llvm
2528
2529	#endif // LLVM_CLANG_AST_DECLBASE_H
2530

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