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/ASTDumperUtils.h"
17	#include "clang/AST/AttrIterator.h"
18	#include "clang/AST/DeclarationName.h"
19	#include "clang/AST/SelectorLocationsKind.h"
20	#include "clang/Basic/IdentifierTable.h"
21	#include "clang/Basic/LLVM.h"
22	#include "clang/Basic/LangOptions.h"
23	#include "clang/Basic/SourceLocation.h"
24	#include "clang/Basic/Specifiers.h"
25	#include "llvm/ADT/ArrayRef.h"
26	#include "llvm/ADT/PointerIntPair.h"
27	#include "llvm/ADT/PointerUnion.h"
28	#include "llvm/ADT/iterator.h"
29	#include "llvm/ADT/iterator_range.h"
30	#include "llvm/Support/Casting.h"
31	#include "llvm/Support/Compiler.h"
32	#include "llvm/Support/PrettyStackTrace.h"
33	#include "llvm/Support/VersionTuple.h"
34	#include <algorithm>
35	#include <cassert>
36	#include <cstddef>
37	#include <iterator>
38	#include <string>
39	#include <type_traits>
40	#include <utility>
41
42	namespace clang {
43
44	class ASTContext;
45	class ASTMutationListener;
46	class Attr;
47	class BlockDecl;
48	class DeclContext;
49	class ExternalSourceSymbolAttr;
50	class FunctionDecl;
51	class FunctionType;
52	class IdentifierInfo;
53	enum class Linkage : unsigned char;
54	class LinkageSpecDecl;
55	class Module;
56	class NamedDecl;
57	class ObjCContainerDecl;
58	class ObjCMethodDecl;
59	struct PrintingPolicy;
60	class RecordDecl;
61	class SourceManager;
62	class Stmt;
63	class StoredDeclsMap;
64	class TemplateDecl;
65	class TemplateParameterList;
66	class TranslationUnitDecl;
67	class UsingDirectiveDecl;
68
69	/// Captures the result of checking the availability of a
70	/// declaration.
71	enum AvailabilityResult {
72	AR_Available = 0,
73	AR_NotYetIntroduced,
74	AR_Deprecated,
75	AR_Unavailable
76	};
77
78	/// Decl - This represents one declaration (or definition), e.g. a variable,
79	/// typedef, function, struct, etc.
80	///
81	/// Note: There are objects tacked on before the *beginning* of Decl
82	/// (and its subclasses) in its Decl::operator new(). Proper alignment
83	/// of all subclasses (not requiring more than the alignment of Decl) is
84	/// asserted in DeclBase.cpp.
85	class alignas(8) Decl {
86	public:
87	/// Lists the kind of concrete classes of Decl.
88	enum Kind {
89	#define DECL(DERIVED, BASE) DERIVED,
90	#define ABSTRACT_DECL(DECL)
91	#define DECL_RANGE(BASE, START, END) \
92	first##BASE = START, last##BASE = END,
93	#define LAST_DECL_RANGE(BASE, START, END) \
94	first##BASE = START, last##BASE = END
95	#include "clang/AST/DeclNodes.inc"
96	};
97
98	/// A placeholder type used to construct an empty shell of a
99	/// decl-derived type that will be filled in later (e.g., by some
100	/// deserialization method).
101	struct EmptyShell {};
102
103	/// IdentifierNamespace - The different namespaces in which
104	/// declarations may appear. According to C99 6.2.3, there are
105	/// four namespaces, labels, tags, members and ordinary
106	/// identifiers. C++ describes lookup completely differently:
107	/// certain lookups merely "ignore" certain kinds of declarations,
108	/// usually based on whether the declaration is of a type, etc.
109	///
110	/// These are meant as bitmasks, so that searches in
111	/// C++ can look into the "tag" namespace during ordinary lookup.
112	///
113	/// Decl currently provides 15 bits of IDNS bits.
114	enum IdentifierNamespace {
115	/// Labels, declared with 'x:' and referenced with 'goto x'.
116	IDNS_Label = 0x0001,
117
118	/// Tags, declared with 'struct foo;' and referenced with
119	/// 'struct foo'. All tags are also types. This is what
120	/// elaborated-type-specifiers look for in C.
121	/// This also contains names that conflict with tags in the
122	/// same scope but that are otherwise ordinary names (non-type
123	/// template parameters and indirect field declarations).
124	IDNS_Tag = 0x0002,
125
126	/// Types, declared with 'struct foo', typedefs, etc.
127	/// This is what elaborated-type-specifiers look for in C++,
128	/// but note that it's ill-formed to find a non-tag.
129	IDNS_Type = 0x0004,
130
131	/// Members, declared with object declarations within tag
132	/// definitions. In C, these can only be found by "qualified"
133	/// lookup in member expressions. In C++, they're found by
134	/// normal lookup.
135	IDNS_Member = 0x0008,
136
137	/// Namespaces, declared with 'namespace foo {}'.
138	/// Lookup for nested-name-specifiers find these.
139	IDNS_Namespace = 0x0010,
140
141	/// Ordinary names. In C, everything that's not a label, tag,
142	/// member, or function-local extern ends up here.
143	IDNS_Ordinary = 0x0020,
144
145	/// Objective C \@protocol.
146	IDNS_ObjCProtocol = 0x0040,
147
148	/// This declaration is a friend function. A friend function
149	/// declaration is always in this namespace but may also be in
150	/// IDNS_Ordinary if it was previously declared.
151	IDNS_OrdinaryFriend = 0x0080,
152
153	/// This declaration is a friend class. A friend class
154	/// declaration is always in this namespace but may also be in
155	/// IDNS_Tag|IDNS_Type if it was previously declared.
156	IDNS_TagFriend = 0x0100,
157
158	/// This declaration is a using declaration. A using declaration
159	/// *introduces* a number of other declarations into the current
160	/// scope, and those declarations use the IDNS of their targets,
161	/// but the actual using declarations go in this namespace.
162	IDNS_Using = 0x0200,
163
164	/// This declaration is a C++ operator declared in a non-class
165	/// context. All such operators are also in IDNS_Ordinary.
166	/// C++ lexical operator lookup looks for these.
167	IDNS_NonMemberOperator = 0x0400,
168
169	/// This declaration is a function-local extern declaration of a
170	/// variable or function. This may also be IDNS_Ordinary if it
171	/// has been declared outside any function. These act mostly like
172	/// invisible friend declarations, but are also visible to unqualified
173	/// lookup within the scope of the declaring function.
174	IDNS_LocalExtern = 0x0800,
175
176	/// This declaration is an OpenMP user defined reduction construction.
177	IDNS_OMPReduction = 0x1000,
178
179	/// This declaration is an OpenMP user defined mapper.
180	IDNS_OMPMapper = 0x2000,
181	};
182
183	/// ObjCDeclQualifier - 'Qualifiers' written next to the return and
184	/// parameter types in method declarations. Other than remembering
185	/// them and mangling them into the method's signature string, these
186	/// are ignored by the compiler; they are consumed by certain
187	/// remote-messaging frameworks.
188	///
189	/// in, inout, and out are mutually exclusive and apply only to
190	/// method parameters. bycopy and byref are mutually exclusive and
191	/// apply only to method parameters (?). oneway applies only to
192	/// results. All of these expect their corresponding parameter to
193	/// have a particular type. None of this is currently enforced by
194	/// clang.
195	///
196	/// This should be kept in sync with ObjCDeclSpec::ObjCDeclQualifier.
197	enum ObjCDeclQualifier {
198	OBJC_TQ_None = 0x0,
199	OBJC_TQ_In = 0x1,
200	OBJC_TQ_Inout = 0x2,
201	OBJC_TQ_Out = 0x4,
202	OBJC_TQ_Bycopy = 0x8,
203	OBJC_TQ_Byref = 0x10,
204	OBJC_TQ_Oneway = 0x20,
205
206	/// The nullability qualifier is set when the nullability of the
207	/// result or parameter was expressed via a context-sensitive
208	/// keyword.
209	OBJC_TQ_CSNullability = 0x40
210	};
211
212	/// The kind of ownership a declaration has, for visibility purposes.
213	/// This enumeration is designed such that higher values represent higher
214	/// levels of name hiding.
215	enum class ModuleOwnershipKind : unsigned char {
216	/// This declaration is not owned by a module.
217	Unowned,
218
219	/// This declaration has an owning module, but is globally visible
220	/// (typically because its owning module is visible and we know that
221	/// modules cannot later become hidden in this compilation).
222	/// After serialization and deserialization, this will be converted
223	/// to VisibleWhenImported.
224	Visible,
225
226	/// This declaration has an owning module, and is visible when that
227	/// module is imported.
228	VisibleWhenImported,
229
230	/// This declaration has an owning module, and is visible to lookups
231	/// that occurs within that module. And it is reachable in other module
232	/// when the owning module is transitively imported.
233	ReachableWhenImported,
234
235	/// This declaration has an owning module, but is only visible to
236	/// lookups that occur within that module.
237	/// The discarded declarations in global module fragment belongs
238	/// to this group too.
239	ModulePrivate
240	};
241
242	/// An ID number that refers to a declaration in an AST file.
243	using DeclID = uint32_t;
244
245	protected:
246	/// The next declaration within the same lexical
247	/// DeclContext. These pointers form the linked list that is
248	/// traversed via DeclContext's decls_begin()/decls_end().
249	///
250	/// The extra three bits are used for the ModuleOwnershipKind.
251	llvm::PointerIntPair<Decl *, 3, ModuleOwnershipKind> NextInContextAndBits;
252
253	private:
254	friend class DeclContext;
255
256	struct MultipleDC {
257	DeclContext *SemanticDC;
258	DeclContext *LexicalDC;
259	};
260
261	/// DeclCtx - Holds either a DeclContext* or a MultipleDC*.
262	/// For declarations that don't contain C++ scope specifiers, it contains
263	/// the DeclContext where the Decl was declared.
264	/// For declarations with C++ scope specifiers, it contains a MultipleDC*
265	/// with the context where it semantically belongs (SemanticDC) and the
266	/// context where it was lexically declared (LexicalDC).
267	/// e.g.:
268	///
269	/// namespace A {
270	/// void f(); // SemanticDC == LexicalDC == 'namespace A'
271	/// }
272	/// void A::f(); // SemanticDC == namespace 'A'
273	/// // LexicalDC == global namespace
274	llvm::PointerUnion<DeclContext*, MultipleDC*> DeclCtx;
275
276	bool isInSemaDC() const { return DeclCtx.is<DeclContext*>(); }
277	bool isOutOfSemaDC() const { return DeclCtx.is<MultipleDC*>(); }
278
279	MultipleDC *getMultipleDC() const {
280	return DeclCtx.get<MultipleDC*>();
281	}
282
283	DeclContext *getSemanticDC() const {
284	return DeclCtx.get<DeclContext*>();
285	}
286
287	/// Loc - The location of this decl.
288	SourceLocation Loc;
289
290	/// DeclKind - This indicates which class this is.
291	LLVM_PREFERRED_TYPE(Kind)
292	unsigned DeclKind : 7;
293
294	/// InvalidDecl - This indicates a semantic error occurred.
295	LLVM_PREFERRED_TYPE(bool)
296	unsigned InvalidDecl : 1;
297
298	/// HasAttrs - This indicates whether the decl has attributes or not.
299	LLVM_PREFERRED_TYPE(bool)
300	unsigned HasAttrs : 1;
301
302	/// Implicit - Whether this declaration was implicitly generated by
303	/// the implementation rather than explicitly written by the user.
304	LLVM_PREFERRED_TYPE(bool)
305	unsigned Implicit : 1;
306
307	/// Whether this declaration was "used", meaning that a definition is
308	/// required.
309	LLVM_PREFERRED_TYPE(bool)
310	unsigned Used : 1;
311
312	/// Whether this declaration was "referenced".
313	/// The difference with 'Used' is whether the reference appears in a
314	/// evaluated context or not, e.g. functions used in uninstantiated templates
315	/// are regarded as "referenced" but not "used".
316	LLVM_PREFERRED_TYPE(bool)
317	unsigned Referenced : 1;
318
319	/// Whether this declaration is a top-level declaration (function,
320	/// global variable, etc.) that is lexically inside an objc container
321	/// definition.
322	LLVM_PREFERRED_TYPE(bool)
323	unsigned TopLevelDeclInObjCContainer : 1;
324
325	/// Whether statistic collection is enabled.
326	static bool StatisticsEnabled;
327
328	protected:
329	friend class ASTDeclReader;
330	friend class ASTDeclWriter;
331	friend class ASTNodeImporter;
332	friend class ASTReader;
333	friend class CXXClassMemberWrapper;
334	friend class LinkageComputer;
335	friend class RecordDecl;
336	template<typename decl_type> friend class Redeclarable;
337
338	/// Access - Used by C++ decls for the access specifier.
339	// NOTE: VC++ treats enums as signed, avoid using the AccessSpecifier enum
340	LLVM_PREFERRED_TYPE(AccessSpecifier)
341	unsigned Access : 2;
342
343	/// Whether this declaration was loaded from an AST file.
344	LLVM_PREFERRED_TYPE(bool)
345	unsigned FromASTFile : 1;
346
347	/// IdentifierNamespace - This specifies what IDNS_* namespace this lives in.
348	LLVM_PREFERRED_TYPE(IdentifierNamespace)
349	unsigned IdentifierNamespace : 14;
350
351	/// If 0, we have not computed the linkage of this declaration.
352	LLVM_PREFERRED_TYPE(Linkage)
353	mutable unsigned CacheValidAndLinkage : 3;
354
355	/// Allocate memory for a deserialized declaration.
356	///
357	/// This routine must be used to allocate memory for any declaration that is
358	/// deserialized from a module file.
359	///
360	/// \param Size The size of the allocated object.
361	/// \param Ctx The context in which we will allocate memory.
362	/// \param ID The global ID of the deserialized declaration.
363	/// \param Extra The amount of extra space to allocate after the object.
364	void *operator new(std::size_t Size, const ASTContext &Ctx, DeclID ID,
365	std::size_t Extra = 0);
366
367	/// Allocate memory for a non-deserialized declaration.
368	void *operator new(std::size_t Size, const ASTContext &Ctx,
369	DeclContext *Parent, std::size_t Extra = 0);
370
371	private:
372	bool AccessDeclContextCheck() const;
373
374	/// Get the module ownership kind to use for a local lexical child of \p DC,
375	/// which may be either a local or (rarely) an imported declaration.
376	static ModuleOwnershipKind getModuleOwnershipKindForChildOf(DeclContext *DC) {
377	if (DC) {
378	auto *D = cast<Decl>(DC);
379	auto MOK = D->getModuleOwnershipKind();
380	if (MOK != ModuleOwnershipKind::Unowned &&
381	(!D->isFromASTFile() || D->hasLocalOwningModuleStorage()))
382	return MOK;
383	// If D is not local and we have no local module storage, then we don't
384	// need to track module ownership at all.
385	}
386	return ModuleOwnershipKind::Unowned;
387	}
388
389	public:
390	Decl() = delete;
391	Decl(const Decl&) = delete;
392	Decl(Decl &&) = delete;
393	Decl &operator=(const Decl&) = delete;
394	Decl &operator=(Decl&&) = delete;
395
396	protected:
397	Decl(Kind DK, DeclContext *DC, SourceLocation L)
398	: NextInContextAndBits(nullptr, getModuleOwnershipKindForChildOf(DC)),
399	DeclCtx(DC), Loc(L), DeclKind(DK), InvalidDecl(false), HasAttrs(false),
400	Implicit(false), Used(false), Referenced(false),
401	TopLevelDeclInObjCContainer(false), Access(AS_none), FromASTFile(0),
402	IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
403	CacheValidAndLinkage(llvm::to_underlying(Linkage::Invalid)) {
404	if (StatisticsEnabled) add(k: DK);
405	}
406
407	Decl(Kind DK, EmptyShell Empty)
408	: DeclKind(DK), InvalidDecl(false), HasAttrs(false), Implicit(false),
409	Used(false), Referenced(false), TopLevelDeclInObjCContainer(false),
410	Access(AS_none), FromASTFile(0),
411	IdentifierNamespace(getIdentifierNamespaceForKind(DK)),
412	CacheValidAndLinkage(llvm::to_underlying(Linkage::Invalid)) {
413	if (StatisticsEnabled) add(k: DK);
414	}
415
416	virtual ~Decl();
417
418	/// Update a potentially out-of-date declaration.
419	void updateOutOfDate(IdentifierInfo &II) const;
420
421	Linkage getCachedLinkage() const {
422	return static_cast<Linkage>(CacheValidAndLinkage);
423	}
424
425	void setCachedLinkage(Linkage L) const {
426	CacheValidAndLinkage = llvm::to_underlying(L);
427	}
428
429	bool hasCachedLinkage() const {
430	return CacheValidAndLinkage;
431	}
432
433	public:
434	/// Source range that this declaration covers.
435	virtual SourceRange getSourceRange() const LLVM_READONLY {
436	return SourceRange(getLocation(), getLocation());
437	}
438
439	SourceLocation getBeginLoc() const LLVM_READONLY {
440	return getSourceRange().getBegin();
441	}
442
443	SourceLocation getEndLoc() const LLVM_READONLY {
444	return getSourceRange().getEnd();
445	}
446
447	SourceLocation getLocation() const { return Loc; }
448	void setLocation(SourceLocation L) { Loc = L; }
449
450	Kind getKind() const { return static_cast<Kind>(DeclKind); }
451	const char *getDeclKindName() const;
452
453	Decl *getNextDeclInContext() { return NextInContextAndBits.getPointer(); }
454	const Decl *getNextDeclInContext() const {return NextInContextAndBits.getPointer();}
455
456	DeclContext *getDeclContext() {
457	if (isInSemaDC())
458	return getSemanticDC();
459	return getMultipleDC()->SemanticDC;
460	}
461	const DeclContext *getDeclContext() const {
462	return const_cast<Decl*>(this)->getDeclContext();
463	}
464
465	/// Return the non transparent context.
466	/// See the comment of `DeclContext::isTransparentContext()` for the
467	/// definition of transparent context.
468	DeclContext *getNonTransparentDeclContext();
469	const DeclContext *getNonTransparentDeclContext() const {
470	return const_cast<Decl *>(this)->getNonTransparentDeclContext();
471	}
472
473	/// Find the innermost non-closure ancestor of this declaration,
474	/// walking up through blocks, lambdas, etc. If that ancestor is
475	/// not a code context (!isFunctionOrMethod()), returns null.
476	///
477	/// A declaration may be its own non-closure context.
478	Decl *getNonClosureContext();
479	const Decl *getNonClosureContext() const {
480	return const_cast<Decl*>(this)->getNonClosureContext();
481	}
482
483	TranslationUnitDecl *getTranslationUnitDecl();
484	const TranslationUnitDecl *getTranslationUnitDecl() const {
485	return const_cast<Decl*>(this)->getTranslationUnitDecl();
486	}
487
488	bool isInAnonymousNamespace() const;
489
490	bool isInStdNamespace() const;
491
492	// Return true if this is a FileContext Decl.
493	bool isFileContextDecl() const;
494
495	/// Whether it resembles a flexible array member. This is a static member
496	/// because we want to be able to call it with a nullptr. That allows us to
497	/// perform non-Decl specific checks based on the object's type and strict
498	/// flex array level.
499	static bool isFlexibleArrayMemberLike(
500	ASTContext &Context, const Decl *D, QualType Ty,
501	LangOptions::StrictFlexArraysLevelKind StrictFlexArraysLevel,
502	bool IgnoreTemplateOrMacroSubstitution);
503
504	ASTContext &getASTContext() const LLVM_READONLY;
505
506	/// Helper to get the language options from the ASTContext.
507	/// Defined out of line to avoid depending on ASTContext.h.
508	const LangOptions &getLangOpts() const LLVM_READONLY;
509
510	void setAccess(AccessSpecifier AS) {
511	Access = AS;
512	assert(AccessDeclContextCheck());
513	}
514
515	AccessSpecifier getAccess() const {
516	assert(AccessDeclContextCheck());
517	return AccessSpecifier(Access);
518	}
519
520	/// Retrieve the access specifier for this declaration, even though
521	/// it may not yet have been properly set.
522	AccessSpecifier getAccessUnsafe() const {
523	return AccessSpecifier(Access);
524	}
525
526	bool hasAttrs() const { return HasAttrs; }
527
528	void setAttrs(const AttrVec& Attrs) {
529	return setAttrsImpl(Attrs, Ctx&: getASTContext());
530	}
531
532	AttrVec &getAttrs() {
533	return const_cast<AttrVec&>(const_cast<const Decl*>(this)->getAttrs());
534	}
535
536	const AttrVec &getAttrs() const;
537	void dropAttrs();
538	void addAttr(Attr *A);
539
540	using attr_iterator = AttrVec::const_iterator;
541	using attr_range = llvm::iterator_range<attr_iterator>;
542
543	attr_range attrs() const {
544	return attr_range(attr_begin(), attr_end());
545	}
546
547	attr_iterator attr_begin() const {
548	return hasAttrs() ? getAttrs().begin() : nullptr;
549	}
550	attr_iterator attr_end() const {
551	return hasAttrs() ? getAttrs().end() : nullptr;
552	}
553
554	template <typename... Ts> void dropAttrs() {
555	if (!HasAttrs) return;
556
557	AttrVec &Vec = getAttrs();
558	llvm::erase_if(Vec, [](Attr *A) { return isa<Ts...>(A); });
559
560	if (Vec.empty())
561	HasAttrs = false;
562	}
563
564	template <typename T> void dropAttr() { dropAttrs<T>(); }
565
566	template <typename T>
567	llvm::iterator_range<specific_attr_iterator<T>> specific_attrs() const {
568	return llvm::make_range(specific_attr_begin<T>(), specific_attr_end<T>());
569	}
570
571	template <typename T>
572	specific_attr_iterator<T> specific_attr_begin() const {
573	return specific_attr_iterator<T>(attr_begin());
574	}
575
576	template <typename T>
577	specific_attr_iterator<T> specific_attr_end() const {
578	return specific_attr_iterator<T>(attr_end());
579	}
580
581	template<typename T> T *getAttr() const {
582	return hasAttrs() ? getSpecificAttr<T>(getAttrs()) : nullptr;
583	}
584
585	template<typename T> bool hasAttr() const {
586	return hasAttrs() && hasSpecificAttr<T>(getAttrs());
587	}
588
589	/// getMaxAlignment - return the maximum alignment specified by attributes
590	/// on this decl, 0 if there are none.
591	unsigned getMaxAlignment() const;
592
593	/// setInvalidDecl - Indicates the Decl had a semantic error. This
594	/// allows for graceful error recovery.
595	void setInvalidDecl(bool Invalid = true);
596	bool isInvalidDecl() const { return (bool) InvalidDecl; }
597
598	/// isImplicit - Indicates whether the declaration was implicitly
599	/// generated by the implementation. If false, this declaration
600	/// was written explicitly in the source code.
601	bool isImplicit() const { return Implicit; }
602	void setImplicit(bool I = true) { Implicit = I; }
603
604	/// Whether *any* (re-)declaration of the entity was used, meaning that
605	/// a definition is required.
606	///
607	/// \param CheckUsedAttr When true, also consider the "used" attribute
608	/// (in addition to the "used" bit set by \c setUsed()) when determining
609	/// whether the function is used.
610	bool isUsed(bool CheckUsedAttr = true) const;
611
612	/// Set whether the declaration is used, in the sense of odr-use.
613	///
614	/// This should only be used immediately after creating a declaration.
615	/// It intentionally doesn't notify any listeners.
616	void setIsUsed() { getCanonicalDecl()->Used = true; }
617
618	/// Mark the declaration used, in the sense of odr-use.
619	///
620	/// This notifies any mutation listeners in addition to setting a bit
621	/// indicating the declaration is used.
622	void markUsed(ASTContext &C);
623
624	/// Whether any declaration of this entity was referenced.
625	bool isReferenced() const;
626
627	/// Whether this declaration was referenced. This should not be relied
628	/// upon for anything other than debugging.
629	bool isThisDeclarationReferenced() const { return Referenced; }
630
631	void setReferenced(bool R = true) { Referenced = R; }
632
633	/// Whether this declaration is a top-level declaration (function,
634	/// global variable, etc.) that is lexically inside an objc container
635	/// definition.
636	bool isTopLevelDeclInObjCContainer() const {
637	return TopLevelDeclInObjCContainer;
638	}
639
640	void setTopLevelDeclInObjCContainer(bool V = true) {
641	TopLevelDeclInObjCContainer = V;
642	}
643
644	/// Looks on this and related declarations for an applicable
645	/// external source symbol attribute.
646	ExternalSourceSymbolAttr *getExternalSourceSymbolAttr() const;
647
648	/// Whether this declaration was marked as being private to the
649	/// module in which it was defined.
650	bool isModulePrivate() const {
651	return getModuleOwnershipKind() == ModuleOwnershipKind::ModulePrivate;
652	}
653
654	/// Whether this declaration was exported in a lexical context.
655	/// e.g.:
656	///
657	/// export namespace A {
658	/// void f1(); // isInExportDeclContext() == true
659	/// }
660	/// void A::f1(); // isInExportDeclContext() == false
661	///
662	/// namespace B {
663	/// void f2(); // isInExportDeclContext() == false
664	/// }
665	/// export void B::f2(); // isInExportDeclContext() == true
666	bool isInExportDeclContext() const;
667
668	bool isInvisibleOutsideTheOwningModule() const {
669	return getModuleOwnershipKind() > ModuleOwnershipKind::VisibleWhenImported;
670	}
671
672	/// Whether this declaration comes from another module unit.
673	bool isInAnotherModuleUnit() const;
674
675	/// Whether this declaration comes from explicit global module.
676	bool isFromExplicitGlobalModule() const;
677
678	/// Return true if this declaration has an attribute which acts as
679	/// definition of the entity, such as 'alias' or 'ifunc'.
680	bool hasDefiningAttr() const;
681
682	/// Return this declaration's defining attribute if it has one.
683	const Attr *getDefiningAttr() const;
684
685	protected:
686	/// Specify that this declaration was marked as being private
687	/// to the module in which it was defined.
688	void setModulePrivate() {
689	// The module-private specifier has no effect on unowned declarations.
690	// FIXME: We should track this in some way for source fidelity.
691	if (getModuleOwnershipKind() == ModuleOwnershipKind::Unowned)
692	return;
693	setModuleOwnershipKind(ModuleOwnershipKind::ModulePrivate);
694	}
695
696	public:
697	/// Set the FromASTFile flag. This indicates that this declaration
698	/// was deserialized and not parsed from source code and enables
699	/// features such as module ownership information.
700	void setFromASTFile() {
701	FromASTFile = true;
702	}
703
704	/// Set the owning module ID. This may only be called for
705	/// deserialized Decls.
706	void setOwningModuleID(unsigned ID) {
707	assert(isFromASTFile() && "Only works on a deserialized declaration");
708	*((unsigned*)this - 2) = ID;
709	}
710
711	public:
712	/// Determine the availability of the given declaration.
713	///
714	/// This routine will determine the most restrictive availability of
715	/// the given declaration (e.g., preferring 'unavailable' to
716	/// 'deprecated').
717	///
718	/// \param Message If non-NULL and the result is not \c
719	/// AR_Available, will be set to a (possibly empty) message
720	/// describing why the declaration has not been introduced, is
721	/// deprecated, or is unavailable.
722	///
723	/// \param EnclosingVersion The version to compare with. If empty, assume the
724	/// deployment target version.
725	///
726	/// \param RealizedPlatform If non-NULL and the availability result is found
727	/// in an available attribute it will set to the platform which is written in
728	/// the available attribute.
729	AvailabilityResult
730	getAvailability(std::string *Message = nullptr,
731	VersionTuple EnclosingVersion = VersionTuple(),
732	StringRef *RealizedPlatform = nullptr) const;
733
734	/// Retrieve the version of the target platform in which this
735	/// declaration was introduced.
736	///
737	/// \returns An empty version tuple if this declaration has no 'introduced'
738	/// availability attributes, or the version tuple that's specified in the
739	/// attribute otherwise.
740	VersionTuple getVersionIntroduced() const;
741
742	/// Determine whether this declaration is marked 'deprecated'.
743	///
744	/// \param Message If non-NULL and the declaration is deprecated,
745	/// this will be set to the message describing why the declaration
746	/// was deprecated (which may be empty).
747	bool isDeprecated(std::string *Message = nullptr) const {
748	return getAvailability(Message) == AR_Deprecated;
749	}
750
751	/// Determine whether this declaration is marked 'unavailable'.
752	///
753	/// \param Message If non-NULL and the declaration is unavailable,
754	/// this will be set to the message describing why the declaration
755	/// was made unavailable (which may be empty).
756	bool isUnavailable(std::string *Message = nullptr) const {
757	return getAvailability(Message) == AR_Unavailable;
758	}
759
760	/// Determine whether this is a weak-imported symbol.
761	///
762	/// Weak-imported symbols are typically marked with the
763	/// 'weak_import' attribute, but may also be marked with an
764	/// 'availability' attribute where we're targing a platform prior to
765	/// the introduction of this feature.
766	bool isWeakImported() const;
767
768	/// Determines whether this symbol can be weak-imported,
769	/// e.g., whether it would be well-formed to add the weak_import
770	/// attribute.
771	///
772	/// \param IsDefinition Set to \c true to indicate that this
773	/// declaration cannot be weak-imported because it has a definition.
774	bool canBeWeakImported(bool &IsDefinition) const;
775
776	/// Determine whether this declaration came from an AST file (such as
777	/// a precompiled header or module) rather than having been parsed.
778	bool isFromASTFile() const { return FromASTFile; }
779
780	/// Retrieve the global declaration ID associated with this
781	/// declaration, which specifies where this Decl was loaded from.
782	DeclID getGlobalID() const {
783	if (isFromASTFile())
784	return *((const DeclID *)this - 1);
785	return 0;
786	}
787
788	/// Retrieve the global ID of the module that owns this particular
789	/// declaration.
790	unsigned getOwningModuleID() const {
791	if (isFromASTFile())
792	return *((const unsigned*)this - 2);
793	return 0;
794	}
795
796	private:
797	Module *getOwningModuleSlow() const;
798
799	protected:
800	bool hasLocalOwningModuleStorage() const;
801
802	public:
803	/// Get the imported owning module, if this decl is from an imported
804	/// (non-local) module.
805	Module *getImportedOwningModule() const {
806	if (!isFromASTFile() || !hasOwningModule())
807	return nullptr;
808
809	return getOwningModuleSlow();
810	}
811
812	/// Get the local owning module, if known. Returns nullptr if owner is
813	/// not yet known or declaration is not from a module.
814	Module *getLocalOwningModule() const {
815	if (isFromASTFile() || !hasOwningModule())
816	return nullptr;
817
818	assert(hasLocalOwningModuleStorage() &&
819	"owned local decl but no local module storage");
820	return reinterpret_cast<Module *const *>(this)[-1];
821	}
822	void setLocalOwningModule(Module *M) {
823	assert(!isFromASTFile() && hasOwningModule() &&
824	hasLocalOwningModuleStorage() &&
825	"should not have a cached owning module");
826	reinterpret_cast<Module **>(this)[-1] = M;
827	}
828
829	/// Is this declaration owned by some module?
830	bool hasOwningModule() const {
831	return getModuleOwnershipKind() != ModuleOwnershipKind::Unowned;
832	}
833
834	/// Get the module that owns this declaration (for visibility purposes).
835	Module *getOwningModule() const {
836	return isFromASTFile() ? getImportedOwningModule() : getLocalOwningModule();
837	}
838
839	/// Get the module that owns this declaration for linkage purposes.
840	/// There only ever is such a standard C++ module.
841	///
842	/// \param IgnoreLinkage Ignore the linkage of the entity; assume that
843	/// all declarations in a global module fragment are unowned.
844	Module *getOwningModuleForLinkage(bool IgnoreLinkage = false) const;
845
846	/// Determine whether this declaration is definitely visible to name lookup,
847	/// independent of whether the owning module is visible.
848	/// Note: The declaration may be visible even if this returns \c false if the
849	/// owning module is visible within the query context. This is a low-level
850	/// helper function; most code should be calling Sema::isVisible() instead.
851	bool isUnconditionallyVisible() const {
852	return (int)getModuleOwnershipKind() <= (int)ModuleOwnershipKind::Visible;
853	}
854
855	bool isReachable() const {
856	return (int)getModuleOwnershipKind() <=
857	(int)ModuleOwnershipKind::ReachableWhenImported;
858	}
859
860	/// Set that this declaration is globally visible, even if it came from a
861	/// module that is not visible.
862	void setVisibleDespiteOwningModule() {
863	if (!isUnconditionallyVisible())
864	setModuleOwnershipKind(ModuleOwnershipKind::Visible);
865	}
866
867	/// Get the kind of module ownership for this declaration.
868	ModuleOwnershipKind getModuleOwnershipKind() const {
869	return NextInContextAndBits.getInt();
870	}
871
872	/// Set whether this declaration is hidden from name lookup.
873	void setModuleOwnershipKind(ModuleOwnershipKind MOK) {
874	assert(!(getModuleOwnershipKind() == ModuleOwnershipKind::Unowned &&
875	MOK != ModuleOwnershipKind::Unowned && !isFromASTFile() &&
876	!hasLocalOwningModuleStorage()) &&
877	"no storage available for owning module for this declaration");
878	NextInContextAndBits.setInt(MOK);
879	}
880
881	unsigned getIdentifierNamespace() const {
882	return IdentifierNamespace;
883	}
884
885	bool isInIdentifierNamespace(unsigned NS) const {
886	return getIdentifierNamespace() & NS;
887	}
888
889	static unsigned getIdentifierNamespaceForKind(Kind DK);
890
891	bool hasTagIdentifierNamespace() const {
892	return isTagIdentifierNamespace(NS: getIdentifierNamespace());
893	}
894
895	static bool isTagIdentifierNamespace(unsigned NS) {
896	// TagDecls have Tag and Type set and may also have TagFriend.
897	return (NS & ~IDNS_TagFriend) == (IDNS_Tag | IDNS_Type);
898	}
899
900	/// getLexicalDeclContext - The declaration context where this Decl was
901	/// lexically declared (LexicalDC). May be different from
902	/// getDeclContext() (SemanticDC).
903	/// e.g.:
904	///
905	/// namespace A {
906	/// void f(); // SemanticDC == LexicalDC == 'namespace A'
907	/// }
908	/// void A::f(); // SemanticDC == namespace 'A'
909	/// // LexicalDC == global namespace
910	DeclContext *getLexicalDeclContext() {
911	if (isInSemaDC())
912	return getSemanticDC();
913	return getMultipleDC()->LexicalDC;
914	}
915	const DeclContext *getLexicalDeclContext() const {
916	return const_cast<Decl*>(this)->getLexicalDeclContext();
917	}
918
919	/// Determine whether this declaration is declared out of line (outside its
920	/// semantic context).
921	virtual bool isOutOfLine() const;
922
923	/// setDeclContext - Set both the semantic and lexical DeclContext
924	/// to DC.
925	void setDeclContext(DeclContext *DC);
926
927	void setLexicalDeclContext(DeclContext *DC);
928
929	/// Determine whether this declaration is a templated entity (whether it is
930	// within the scope of a template parameter).
931	bool isTemplated() const;
932
933	/// Determine the number of levels of template parameter surrounding this
934	/// declaration.
935	unsigned getTemplateDepth() const;
936
937	/// isDefinedOutsideFunctionOrMethod - This predicate returns true if this
938	/// scoped decl is defined outside the current function or method. This is
939	/// roughly global variables and functions, but also handles enums (which
940	/// could be defined inside or outside a function etc).
941	bool isDefinedOutsideFunctionOrMethod() const {
942	return getParentFunctionOrMethod() == nullptr;
943	}
944
945	/// Determine whether a substitution into this declaration would occur as
946	/// part of a substitution into a dependent local scope. Such a substitution
947	/// transitively substitutes into all constructs nested within this
948	/// declaration.
949	///
950	/// This recognizes non-defining declarations as well as members of local
951	/// classes and lambdas:
952	/// \code
953	/// template<typename T> void foo() { void bar(); }
954	/// template<typename T> void foo2() { class ABC { void bar(); }; }
955	/// template<typename T> inline int x = [](){ return 0; }();
956	/// \endcode
957	bool isInLocalScopeForInstantiation() const;
958
959	/// If this decl is defined inside a function/method/block it returns
960	/// the corresponding DeclContext, otherwise it returns null.
961	const DeclContext *
962	getParentFunctionOrMethod(bool LexicalParent = false) const;
963	DeclContext *getParentFunctionOrMethod(bool LexicalParent = false) {
964	return const_cast<DeclContext *>(
965	const_cast<const Decl *>(this)->getParentFunctionOrMethod(
966	LexicalParent));
967	}
968
969	/// Retrieves the "canonical" declaration of the given declaration.
970	virtual Decl *getCanonicalDecl() { return this; }
971	const Decl *getCanonicalDecl() const {
972	return const_cast<Decl*>(this)->getCanonicalDecl();
973	}
974
975	/// Whether this particular Decl is a canonical one.
976	bool isCanonicalDecl() const { return getCanonicalDecl() == this; }
977
978	protected:
979	/// Returns the next redeclaration or itself if this is the only decl.
980	///
981	/// Decl subclasses that can be redeclared should override this method so that
982	/// Decl::redecl_iterator can iterate over them.
983	virtual Decl *getNextRedeclarationImpl() { return this; }
984
985	/// Implementation of getPreviousDecl(), to be overridden by any
986	/// subclass that has a redeclaration chain.
987	virtual Decl *getPreviousDeclImpl() { return nullptr; }
988
989	/// Implementation of getMostRecentDecl(), to be overridden by any
990	/// subclass that has a redeclaration chain.
991	virtual Decl *getMostRecentDeclImpl() { return this; }
992
993	public:
994	/// Iterates through all the redeclarations of the same decl.
995	class redecl_iterator {
996	/// Current - The current declaration.
997	Decl *Current = nullptr;
998	Decl *Starter;
999
1000	public:
1001	using value_type = Decl *;
1002	using reference = const value_type &;
1003	using pointer = const value_type *;
1004	using iterator_category = std::forward_iterator_tag;
1005	using difference_type = std::ptrdiff_t;
1006
1007	redecl_iterator() = default;
1008	explicit redecl_iterator(Decl *C) : Current(C), Starter(C) {}
1009
1010	reference operator*() const { return Current; }
1011	value_type operator->() const { return Current; }
1012
1013	redecl_iterator& operator++() {
1014	assert(Current && "Advancing while iterator has reached end");
1015	// Get either previous decl or latest decl.
1016	Decl *Next = Current->getNextRedeclarationImpl();
1017	assert(Next && "Should return next redeclaration or itself, never null!");
1018	Current = (Next != Starter) ? Next : nullptr;
1019	return *this;
1020	}
1021
1022	redecl_iterator operator++(int) {
1023	redecl_iterator tmp(*this);
1024	++(*this);
1025	return tmp;
1026	}
1027
1028	friend bool operator==(redecl_iterator x, redecl_iterator y) {
1029	return x.Current == y.Current;
1030	}
1031
1032	friend bool operator!=(redecl_iterator x, redecl_iterator y) {
1033	return x.Current != y.Current;
1034	}
1035	};
1036
1037	using redecl_range = llvm::iterator_range<redecl_iterator>;
1038
1039	/// Returns an iterator range for all the redeclarations of the same
1040	/// decl. It will iterate at least once (when this decl is the only one).
1041	redecl_range redecls() const {
1042	return redecl_range(redecls_begin(), redecls_end());
1043	}
1044
1045	redecl_iterator redecls_begin() const {
1046	return redecl_iterator(const_cast<Decl *>(this));
1047	}
1048
1049	redecl_iterator redecls_end() const { return redecl_iterator(); }
1050
1051	/// Retrieve the previous declaration that declares the same entity
1052	/// as this declaration, or NULL if there is no previous declaration.
1053	Decl *getPreviousDecl() { return getPreviousDeclImpl(); }
1054
1055	/// Retrieve the previous declaration that declares the same entity
1056	/// as this declaration, or NULL if there is no previous declaration.
1057	const Decl *getPreviousDecl() const {
1058	return const_cast<Decl *>(this)->getPreviousDeclImpl();
1059	}
1060
1061	/// True if this is the first declaration in its redeclaration chain.
1062	bool isFirstDecl() const {
1063	return getPreviousDecl() == nullptr;
1064	}
1065
1066	/// Retrieve the most recent declaration that declares the same entity
1067	/// as this declaration (which may be this declaration).
1068	Decl *getMostRecentDecl() { return getMostRecentDeclImpl(); }
1069
1070	/// Retrieve the most recent declaration that declares the same entity
1071	/// as this declaration (which may be this declaration).
1072	const Decl *getMostRecentDecl() const {
1073	return const_cast<Decl *>(this)->getMostRecentDeclImpl();
1074	}
1075
1076	/// getBody - If this Decl represents a declaration for a body of code,
1077	/// such as a function or method definition, this method returns the
1078	/// top-level Stmt* of that body. Otherwise this method returns null.
1079	virtual Stmt* getBody() const { return nullptr; }
1080
1081	/// Returns true if this \c Decl represents a declaration for a body of
1082	/// code, such as a function or method definition.
1083	/// Note that \c hasBody can also return true if any redeclaration of this
1084	/// \c Decl represents a declaration for a body of code.
1085	virtual bool hasBody() const { return getBody() != nullptr; }
1086
1087	/// getBodyRBrace - Gets the right brace of the body, if a body exists.
1088	/// This works whether the body is a CompoundStmt or a CXXTryStmt.
1089	SourceLocation getBodyRBrace() const;
1090
1091	// global temp stats (until we have a per-module visitor)
1092	static void add(Kind k);
1093	static void EnableStatistics();
1094	static void PrintStats();
1095
1096	/// isTemplateParameter - Determines whether this declaration is a
1097	/// template parameter.
1098	bool isTemplateParameter() const;
1099
1100	/// isTemplateParameter - Determines whether this declaration is a
1101	/// template parameter pack.
1102	bool isTemplateParameterPack() const;
1103
1104	/// Whether this declaration is a parameter pack.
1105	bool isParameterPack() const;
1106
1107	/// returns true if this declaration is a template
1108	bool isTemplateDecl() const;
1109
1110	/// Whether this declaration is a function or function template.
1111	bool isFunctionOrFunctionTemplate() const {
1112	return (DeclKind >= Decl::firstFunction &&
1113	DeclKind <= Decl::lastFunction) ||
1114	DeclKind == FunctionTemplate;
1115	}
1116
1117	/// If this is a declaration that describes some template, this
1118	/// method returns that template declaration.
1119	///
1120	/// Note that this returns nullptr for partial specializations, because they
1121	/// are not modeled as TemplateDecls. Use getDescribedTemplateParams to handle
1122	/// those cases.
1123	TemplateDecl *getDescribedTemplate() const;
1124
1125	/// If this is a declaration that describes some template or partial
1126	/// specialization, this returns the corresponding template parameter list.
1127	const TemplateParameterList *getDescribedTemplateParams() const;
1128
1129	/// Returns the function itself, or the templated function if this is a
1130	/// function template.
1131	FunctionDecl *getAsFunction() LLVM_READONLY;
1132
1133	const FunctionDecl *getAsFunction() const {
1134	return const_cast<Decl *>(this)->getAsFunction();
1135	}
1136
1137	/// Changes the namespace of this declaration to reflect that it's
1138	/// a function-local extern declaration.
1139	///
1140	/// These declarations appear in the lexical context of the extern
1141	/// declaration, but in the semantic context of the enclosing namespace
1142	/// scope.
1143	void setLocalExternDecl() {
1144	Decl *Prev = getPreviousDecl();
1145	IdentifierNamespace &= ~IDNS_Ordinary;
1146
1147	// It's OK for the declaration to still have the "invisible friend" flag or
1148	// the "conflicts with tag declarations in this scope" flag for the outer
1149	// scope.
1150	assert((IdentifierNamespace & ~(IDNS_OrdinaryFriend | IDNS_Tag)) == 0 &&
1151	"namespace is not ordinary");
1152
1153	IdentifierNamespace |= IDNS_LocalExtern;
1154	if (Prev && Prev->getIdentifierNamespace() & IDNS_Ordinary)
1155	IdentifierNamespace |= IDNS_Ordinary;
1156	}
1157
1158	/// Determine whether this is a block-scope declaration with linkage.
1159	/// This will either be a local variable declaration declared 'extern', or a
1160	/// local function declaration.
1161	bool isLocalExternDecl() const {
1162	return IdentifierNamespace & IDNS_LocalExtern;
1163	}
1164
1165	/// Changes the namespace of this declaration to reflect that it's
1166	/// the object of a friend declaration.
1167	///
1168	/// These declarations appear in the lexical context of the friending
1169	/// class, but in the semantic context of the actual entity. This property
1170	/// applies only to a specific decl object; other redeclarations of the
1171	/// same entity may not (and probably don't) share this property.
1172	void setObjectOfFriendDecl(bool PerformFriendInjection = false) {
1173	unsigned OldNS = IdentifierNamespace;
1174	assert((OldNS & (IDNS_Tag | IDNS_Ordinary |
1175	IDNS_TagFriend | IDNS_OrdinaryFriend |
1176	IDNS_LocalExtern | IDNS_NonMemberOperator)) &&
1177	"namespace includes neither ordinary nor tag");
1178	assert(!(OldNS & ~(IDNS_Tag | IDNS_Ordinary | IDNS_Type |
1179	IDNS_TagFriend | IDNS_OrdinaryFriend |
1180	IDNS_LocalExtern | IDNS_NonMemberOperator)) &&
1181	"namespace includes other than ordinary or tag");
1182
1183	Decl *Prev = getPreviousDecl();
1184	IdentifierNamespace &= ~(IDNS_Ordinary | IDNS_Tag | IDNS_Type);
1185
1186	if (OldNS & (IDNS_Tag | IDNS_TagFriend)) {
1187	IdentifierNamespace |= IDNS_TagFriend;
1188	if (PerformFriendInjection ||
1189	(Prev && Prev->getIdentifierNamespace() & IDNS_Tag))
1190	IdentifierNamespace |= IDNS_Tag | IDNS_Type;
1191	}
1192
1193	if (OldNS & (IDNS_Ordinary | IDNS_OrdinaryFriend |
1194	IDNS_LocalExtern | IDNS_NonMemberOperator)) {
1195	IdentifierNamespace |= IDNS_OrdinaryFriend;
1196	if (PerformFriendInjection ||
1197	(Prev && Prev->getIdentifierNamespace() & IDNS_Ordinary))
1198	IdentifierNamespace |= IDNS_Ordinary;
1199	}
1200	}
1201
1202	/// Clears the namespace of this declaration.
1203	///
1204	/// This is useful if we want this declaration to be available for
1205	/// redeclaration lookup but otherwise hidden for ordinary name lookups.
1206	void clearIdentifierNamespace() { IdentifierNamespace = 0; }
1207
1208	enum FriendObjectKind {
1209	FOK_None, ///< Not a friend object.
1210	FOK_Declared, ///< A friend of a previously-declared entity.
1211	FOK_Undeclared ///< A friend of a previously-undeclared entity.
1212	};
1213
1214	/// Determines whether this declaration is the object of a
1215	/// friend declaration and, if so, what kind.
1216	///
1217	/// There is currently no direct way to find the associated FriendDecl.
1218	FriendObjectKind getFriendObjectKind() const {
1219	unsigned mask =
1220	(IdentifierNamespace & (IDNS_TagFriend | IDNS_OrdinaryFriend));
1221	if (!mask) return FOK_None;
1222	return (IdentifierNamespace & (IDNS_Tag | IDNS_Ordinary) ? FOK_Declared
1223	: FOK_Undeclared);
1224	}
1225
1226	/// Specifies that this declaration is a C++ overloaded non-member.
1227	void setNonMemberOperator() {
1228	assert(getKind() == Function || getKind() == FunctionTemplate);
1229	assert((IdentifierNamespace & IDNS_Ordinary) &&
1230	"visible non-member operators should be in ordinary namespace");
1231	IdentifierNamespace |= IDNS_NonMemberOperator;
1232	}
1233
1234	static bool classofKind(Kind K) { return true; }
1235	static DeclContext *castToDeclContext(const Decl *);
1236	static Decl *castFromDeclContext(const DeclContext *);
1237
1238	void print(raw_ostream &Out, unsigned Indentation = 0,
1239	bool PrintInstantiation = false) const;
1240	void print(raw_ostream &Out, const PrintingPolicy &Policy,
1241	unsigned Indentation = 0, bool PrintInstantiation = false) const;
1242	static void printGroup(Decl** Begin, unsigned NumDecls,
1243	raw_ostream &Out, const PrintingPolicy &Policy,
1244	unsigned Indentation = 0);
1245
1246	// Debuggers don't usually respect default arguments.
1247	void dump() const;
1248
1249	// Same as dump(), but forces color printing.
1250	void dumpColor() const;
1251
1252	void dump(raw_ostream &Out, bool Deserialize = false,
1253	ASTDumpOutputFormat OutputFormat = ADOF_Default) const;
1254
1255	/// \return Unique reproducible object identifier
1256	int64_t getID() const;
1257
1258	/// Looks through the Decl's underlying type to extract a FunctionType
1259	/// when possible. Will return null if the type underlying the Decl does not
1260	/// have a FunctionType.
1261	const FunctionType *getFunctionType(bool BlocksToo = true) const;
1262
1263	// Looks through the Decl's underlying type to determine if it's a
1264	// function pointer type.
1265	bool isFunctionPointerType() const;
1266
1267	private:
1268	void setAttrsImpl(const AttrVec& Attrs, ASTContext &Ctx);
1269	void setDeclContextsImpl(DeclContext *SemaDC, DeclContext *LexicalDC,
1270	ASTContext &Ctx);
1271
1272	protected:
1273	ASTMutationListener *getASTMutationListener() const;
1274	};
1275
1276	/// Determine whether two declarations declare the same entity.
1277	inline bool declaresSameEntity(const Decl *D1, const Decl *D2) {
1278	if (!D1 || !D2)
1279	return false;
1280
1281	if (D1 == D2)
1282	return true;
1283
1284	return D1->getCanonicalDecl() == D2->getCanonicalDecl();
1285	}
1286
1287	/// PrettyStackTraceDecl - If a crash occurs, indicate that it happened when
1288	/// doing something to a specific decl.
1289	class PrettyStackTraceDecl : public llvm::PrettyStackTraceEntry {
1290	const Decl *TheDecl;
1291	SourceLocation Loc;
1292	SourceManager &SM;
1293	const char *Message;
1294
1295	public:
1296	PrettyStackTraceDecl(const Decl *theDecl, SourceLocation L,
1297	SourceManager &sm, const char *Msg)
1298	: TheDecl(theDecl), Loc(L), SM(sm), Message(Msg) {}
1299
1300	void print(raw_ostream &OS) const override;
1301	};
1302	} // namespace clang
1303
1304	// Required to determine the layout of the PointerUnion<NamedDecl*> before
1305	// seeing the NamedDecl definition being first used in DeclListNode::operator*.
1306	namespace llvm {
1307	template <> struct PointerLikeTypeTraits<::clang::NamedDecl *> {
1308	static inline void *getAsVoidPointer(::clang::NamedDecl *P) { return P; }
1309	static inline ::clang::NamedDecl *getFromVoidPointer(void *P) {
1310	return static_cast<::clang::NamedDecl *>(P);
1311	}
1312	static constexpr int NumLowBitsAvailable = 3;
1313	};
1314	}
1315
1316	namespace clang {
1317	/// A list storing NamedDecls in the lookup tables.
1318	class DeclListNode {
1319	friend class ASTContext; // allocate, deallocate nodes.
1320	friend class StoredDeclsList;
1321	public:
1322	using Decls = llvm::PointerUnion<NamedDecl*, DeclListNode*>;
1323	class iterator {
1324	friend class DeclContextLookupResult;
1325	friend class StoredDeclsList;
1326
1327	Decls Ptr;
1328	iterator(Decls Node) : Ptr(Node) { }
1329	public:
1330	using difference_type = ptrdiff_t;
1331	using value_type = NamedDecl*;
1332	using pointer = void;
1333	using reference = value_type;
1334	using iterator_category = std::forward_iterator_tag;
1335
1336	iterator() = default;
1337
1338	reference operator*() const {
1339	assert(Ptr && "dereferencing end() iterator");
1340	if (DeclListNode *CurNode = Ptr.dyn_cast<DeclListNode*>())
1341	return CurNode->D;
1342	return Ptr.get<NamedDecl*>();
1343	}
1344	void operator->() const { } // Unsupported.
1345	bool operator==(const iterator &X) const { return Ptr == X.Ptr; }
1346	bool operator!=(const iterator &X) const { return Ptr != X.Ptr; }
1347	inline iterator &operator++() { // ++It
1348	assert(!Ptr.isNull() && "Advancing empty iterator");
1349
1350	if (DeclListNode *CurNode = Ptr.dyn_cast<DeclListNode*>())
1351	Ptr = CurNode->Rest;
1352	else
1353	Ptr = nullptr;
1354	return *this;
1355	}
1356	iterator operator++(int) { // It++
1357	iterator temp = *this;
1358	++(*this);
1359	return temp;
1360	}
1361	// Enables the pattern for (iterator I =..., E = I.end(); I != E; ++I)
1362	iterator end() { return iterator(); }
1363	};
1364	private:
1365	NamedDecl *D = nullptr;
1366	Decls Rest = nullptr;
1367	DeclListNode(NamedDecl *ND) : D(ND) {}
1368	};
1369
1370	/// The results of name lookup within a DeclContext.
1371	class DeclContextLookupResult {
1372	using Decls = DeclListNode::Decls;
1373
1374	/// When in collection form, this is what the Data pointer points to.
1375	Decls Result;
1376
1377	public:
1378	DeclContextLookupResult() = default;
1379	DeclContextLookupResult(Decls Result) : Result(Result) {}
1380
1381	using iterator = DeclListNode::iterator;
1382	using const_iterator = iterator;
1383	using reference = iterator::reference;
1384
1385	iterator begin() { return iterator(Result); }
1386	iterator end() { return iterator(); }
1387	const_iterator begin() const {
1388	return const_cast<DeclContextLookupResult*>(this)->begin();
1389	}
1390	const_iterator end() const { return iterator(); }
1391
1392	bool empty() const { return Result.isNull(); }
1393	bool isSingleResult() const { return Result.dyn_cast<NamedDecl*>(); }
1394	reference front() const { return *begin(); }
1395
1396	// Find the first declaration of the given type in the list. Note that this
1397	// is not in general the earliest-declared declaration, and should only be
1398	// used when it's not possible for there to be more than one match or where
1399	// it doesn't matter which one is found.
1400	template<class T> T *find_first() const {
1401	for (auto *D : *this)
1402	if (T *Decl = dyn_cast<T>(D))
1403	return Decl;
1404
1405	return nullptr;
1406	}
1407	};
1408
1409	/// Only used by CXXDeductionGuideDecl.
1410	enum class DeductionCandidate : unsigned char {
1411	Normal,
1412	Copy,
1413	Aggregate,
1414	};
1415
1416	enum class RecordArgPassingKind;
1417	enum class OMPDeclareReductionInitKind;
1418	enum class ObjCImplementationControl;
1419	enum class LinkageSpecLanguageIDs;
1420
1421	/// DeclContext - This is used only as base class of specific decl types that
1422	/// can act as declaration contexts. These decls are (only the top classes
1423	/// that directly derive from DeclContext are mentioned, not their subclasses):
1424	///
1425	/// TranslationUnitDecl
1426	/// ExternCContext
1427	/// NamespaceDecl
1428	/// TagDecl
1429	/// OMPDeclareReductionDecl
1430	/// OMPDeclareMapperDecl
1431	/// FunctionDecl
1432	/// ObjCMethodDecl
1433	/// ObjCContainerDecl
1434	/// LinkageSpecDecl
1435	/// ExportDecl
1436	/// BlockDecl
1437	/// CapturedDecl
1438	class DeclContext {
1439	/// For makeDeclVisibleInContextImpl
1440	friend class ASTDeclReader;
1441	/// For checking the new bits in the Serialization part.
1442	friend class ASTDeclWriter;
1443	/// For reconcileExternalVisibleStorage, CreateStoredDeclsMap,
1444	/// hasNeedToReconcileExternalVisibleStorage
1445	friend class ExternalASTSource;
1446	/// For CreateStoredDeclsMap
1447	friend class DependentDiagnostic;
1448	/// For hasNeedToReconcileExternalVisibleStorage,
1449	/// hasLazyLocalLexicalLookups, hasLazyExternalLexicalLookups
1450	friend class ASTWriter;
1451
1452	// We use uint64_t in the bit-fields below since some bit-fields
1453	// cross the unsigned boundary and this breaks the packing.
1454
1455	/// Stores the bits used by DeclContext.
1456	/// If modified NumDeclContextBit, the ctor of DeclContext and the accessor
1457	/// methods in DeclContext should be updated appropriately.
1458	class DeclContextBitfields {
1459	friend class DeclContext;
1460	/// DeclKind - This indicates which class this is.
1461	LLVM_PREFERRED_TYPE(Decl::Kind)
1462	uint64_t DeclKind : 7;
1463
1464	/// Whether this declaration context also has some external
1465	/// storage that contains additional declarations that are lexically
1466	/// part of this context.
1467	LLVM_PREFERRED_TYPE(bool)
1468	mutable uint64_t ExternalLexicalStorage : 1;
1469
1470	/// Whether this declaration context also has some external
1471	/// storage that contains additional declarations that are visible
1472	/// in this context.
1473	LLVM_PREFERRED_TYPE(bool)
1474	mutable uint64_t ExternalVisibleStorage : 1;
1475
1476	/// Whether this declaration context has had externally visible
1477	/// storage added since the last lookup. In this case, \c LookupPtr's
1478	/// invariant may not hold and needs to be fixed before we perform
1479	/// another lookup.
1480	LLVM_PREFERRED_TYPE(bool)
1481	mutable uint64_t NeedToReconcileExternalVisibleStorage : 1;
1482
1483	/// If \c true, this context may have local lexical declarations
1484	/// that are missing from the lookup table.
1485	LLVM_PREFERRED_TYPE(bool)
1486	mutable uint64_t HasLazyLocalLexicalLookups : 1;
1487
1488	/// If \c true, the external source may have lexical declarations
1489	/// that are missing from the lookup table.
1490	LLVM_PREFERRED_TYPE(bool)
1491	mutable uint64_t HasLazyExternalLexicalLookups : 1;
1492
1493	/// If \c true, lookups should only return identifier from
1494	/// DeclContext scope (for example TranslationUnit). Used in
1495	/// LookupQualifiedName()
1496	LLVM_PREFERRED_TYPE(bool)
1497	mutable uint64_t UseQualifiedLookup : 1;
1498	};
1499
1500	/// Number of bits in DeclContextBitfields.
1501	enum { NumDeclContextBits = 13 };
1502
1503	/// Stores the bits used by TagDecl.
1504	/// If modified NumTagDeclBits and the accessor
1505	/// methods in TagDecl should be updated appropriately.
1506	class TagDeclBitfields {
1507	friend class TagDecl;
1508	/// For the bits in DeclContextBitfields
1509	LLVM_PREFERRED_TYPE(DeclContextBitfields)
1510	uint64_t : NumDeclContextBits;
1511
1512	/// The TagKind enum.
1513	LLVM_PREFERRED_TYPE(TagTypeKind)
1514	uint64_t TagDeclKind : 3;
1515
1516	/// True if this is a definition ("struct foo {};"), false if it is a
1517	/// declaration ("struct foo;"). It is not considered a definition
1518	/// until the definition has been fully processed.
1519	LLVM_PREFERRED_TYPE(bool)
1520	uint64_t IsCompleteDefinition : 1;
1521
1522	/// True if this is currently being defined.
1523	LLVM_PREFERRED_TYPE(bool)
1524	uint64_t IsBeingDefined : 1;
1525
1526	/// True if this tag declaration is "embedded" (i.e., defined or declared
1527	/// for the very first time) in the syntax of a declarator.
1528	LLVM_PREFERRED_TYPE(bool)
1529	uint64_t IsEmbeddedInDeclarator : 1;
1530
1531	/// True if this tag is free standing, e.g. "struct foo;".
1532	LLVM_PREFERRED_TYPE(bool)
1533	uint64_t IsFreeStanding : 1;
1534
1535	/// Indicates whether it is possible for declarations of this kind
1536	/// to have an out-of-date definition.
1537	///
1538	/// This option is only enabled when modules are enabled.
1539	LLVM_PREFERRED_TYPE(bool)
1540	uint64_t MayHaveOutOfDateDef : 1;
1541
1542	/// Has the full definition of this type been required by a use somewhere in
1543	/// the TU.
1544	LLVM_PREFERRED_TYPE(bool)
1545	uint64_t IsCompleteDefinitionRequired : 1;
1546
1547	/// Whether this tag is a definition which was demoted due to
1548	/// a module merge.
1549	LLVM_PREFERRED_TYPE(bool)
1550	uint64_t IsThisDeclarationADemotedDefinition : 1;
1551	};
1552
1553	/// Number of inherited and non-inherited bits in TagDeclBitfields.
1554	enum { NumTagDeclBits = NumDeclContextBits + 10 };
1555
1556	/// Stores the bits used by EnumDecl.
1557	/// If modified NumEnumDeclBit and the accessor
1558	/// methods in EnumDecl should be updated appropriately.
1559	class EnumDeclBitfields {
1560	friend class EnumDecl;
1561	/// For the bits in TagDeclBitfields.
1562	LLVM_PREFERRED_TYPE(TagDeclBitfields)
1563	uint64_t : NumTagDeclBits;
1564
1565	/// Width in bits required to store all the non-negative
1566	/// enumerators of this enum.
1567	uint64_t NumPositiveBits : 8;
1568
1569	/// Width in bits required to store all the negative
1570	/// enumerators of this enum.
1571	uint64_t NumNegativeBits : 8;
1572
1573	/// True if this tag declaration is a scoped enumeration. Only
1574	/// possible in C++11 mode.
1575	LLVM_PREFERRED_TYPE(bool)
1576	uint64_t IsScoped : 1;
1577
1578	/// If this tag declaration is a scoped enum,
1579	/// then this is true if the scoped enum was declared using the class
1580	/// tag, false if it was declared with the struct tag. No meaning is
1581	/// associated if this tag declaration is not a scoped enum.
1582	LLVM_PREFERRED_TYPE(bool)
1583	uint64_t IsScopedUsingClassTag : 1;
1584
1585	/// True if this is an enumeration with fixed underlying type. Only
1586	/// possible in C++11, Microsoft extensions, or Objective C mode.
1587	LLVM_PREFERRED_TYPE(bool)
1588	uint64_t IsFixed : 1;
1589
1590	/// True if a valid hash is stored in ODRHash.
1591	LLVM_PREFERRED_TYPE(bool)
1592	uint64_t HasODRHash : 1;
1593	};
1594
1595	/// Number of inherited and non-inherited bits in EnumDeclBitfields.
1596	enum { NumEnumDeclBits = NumTagDeclBits + 20 };
1597
1598	/// Stores the bits used by RecordDecl.
1599	/// If modified NumRecordDeclBits and the accessor
1600	/// methods in RecordDecl should be updated appropriately.
1601	class RecordDeclBitfields {
1602	friend class RecordDecl;
1603	/// For the bits in TagDeclBitfields.
1604	LLVM_PREFERRED_TYPE(TagDeclBitfields)
1605	uint64_t : NumTagDeclBits;
1606
1607	/// This is true if this struct ends with a flexible
1608	/// array member (e.g. int X[]) or if this union contains a struct that does.
1609	/// If so, this cannot be contained in arrays or other structs as a member.
1610	LLVM_PREFERRED_TYPE(bool)
1611	uint64_t HasFlexibleArrayMember : 1;
1612
1613	/// Whether this is the type of an anonymous struct or union.
1614	LLVM_PREFERRED_TYPE(bool)
1615	uint64_t AnonymousStructOrUnion : 1;
1616
1617	/// This is true if this struct has at least one member
1618	/// containing an Objective-C object pointer type.
1619	LLVM_PREFERRED_TYPE(bool)
1620	uint64_t HasObjectMember : 1;
1621
1622	/// This is true if struct has at least one member of
1623	/// 'volatile' type.
1624	LLVM_PREFERRED_TYPE(bool)
1625	uint64_t HasVolatileMember : 1;
1626
1627	/// Whether the field declarations of this record have been loaded
1628	/// from external storage. To avoid unnecessary deserialization of
1629	/// methods/nested types we allow deserialization of just the fields
1630	/// when needed.
1631	LLVM_PREFERRED_TYPE(bool)
1632	mutable uint64_t LoadedFieldsFromExternalStorage : 1;
1633
1634	/// Basic properties of non-trivial C structs.
1635	LLVM_PREFERRED_TYPE(bool)
1636	uint64_t NonTrivialToPrimitiveDefaultInitialize : 1;
1637	LLVM_PREFERRED_TYPE(bool)
1638	uint64_t NonTrivialToPrimitiveCopy : 1;
1639	LLVM_PREFERRED_TYPE(bool)
1640	uint64_t NonTrivialToPrimitiveDestroy : 1;
1641
1642	/// The following bits indicate whether this is or contains a C union that
1643	/// is non-trivial to default-initialize, destruct, or copy. These bits
1644	/// imply the associated basic non-triviality predicates declared above.
1645	LLVM_PREFERRED_TYPE(bool)
1646	uint64_t HasNonTrivialToPrimitiveDefaultInitializeCUnion : 1;
1647	LLVM_PREFERRED_TYPE(bool)
1648	uint64_t HasNonTrivialToPrimitiveDestructCUnion : 1;
1649	LLVM_PREFERRED_TYPE(bool)
1650	uint64_t HasNonTrivialToPrimitiveCopyCUnion : 1;
1651
1652	/// Indicates whether this struct is destroyed in the callee.
1653	LLVM_PREFERRED_TYPE(bool)
1654	uint64_t ParamDestroyedInCallee : 1;
1655
1656	/// Represents the way this type is passed to a function.
1657	LLVM_PREFERRED_TYPE(RecordArgPassingKind)
1658	uint64_t ArgPassingRestrictions : 2;
1659
1660	/// Indicates whether this struct has had its field layout randomized.
1661	LLVM_PREFERRED_TYPE(bool)
1662	uint64_t IsRandomized : 1;
1663
1664	/// True if a valid hash is stored in ODRHash. This should shave off some
1665	/// extra storage and prevent CXXRecordDecl to store unused bits.
1666	uint64_t ODRHash : 26;
1667	};
1668
1669	/// Number of inherited and non-inherited bits in RecordDeclBitfields.
1670	enum { NumRecordDeclBits = NumTagDeclBits + 41 };
1671
1672	/// Stores the bits used by OMPDeclareReductionDecl.
1673	/// If modified NumOMPDeclareReductionDeclBits and the accessor
1674	/// methods in OMPDeclareReductionDecl should be updated appropriately.
1675	class OMPDeclareReductionDeclBitfields {
1676	friend class OMPDeclareReductionDecl;
1677	/// For the bits in DeclContextBitfields
1678	LLVM_PREFERRED_TYPE(DeclContextBitfields)
1679	uint64_t : NumDeclContextBits;
1680
1681	/// Kind of initializer,
1682	/// function call or omp_priv<init_expr> initialization.
1683	LLVM_PREFERRED_TYPE(OMPDeclareReductionInitKind)
1684	uint64_t InitializerKind : 2;
1685	};
1686
1687	/// Number of inherited and non-inherited bits in
1688	/// OMPDeclareReductionDeclBitfields.
1689	enum { NumOMPDeclareReductionDeclBits = NumDeclContextBits + 2 };
1690
1691	/// Stores the bits used by FunctionDecl.
1692	/// If modified NumFunctionDeclBits and the accessor
1693	/// methods in FunctionDecl and CXXDeductionGuideDecl
1694	/// (for DeductionCandidateKind) should be updated appropriately.
1695	class FunctionDeclBitfields {
1696	friend class FunctionDecl;
1697	/// For DeductionCandidateKind
1698	friend class CXXDeductionGuideDecl;
1699	/// For the bits in DeclContextBitfields.
1700	LLVM_PREFERRED_TYPE(DeclContextBitfields)
1701	uint64_t : NumDeclContextBits;
1702
1703	LLVM_PREFERRED_TYPE(StorageClass)
1704	uint64_t SClass : 3;
1705	LLVM_PREFERRED_TYPE(bool)
1706	uint64_t IsInline : 1;
1707	LLVM_PREFERRED_TYPE(bool)
1708	uint64_t IsInlineSpecified : 1;
1709
1710	LLVM_PREFERRED_TYPE(bool)
1711	uint64_t IsVirtualAsWritten : 1;
1712	LLVM_PREFERRED_TYPE(bool)
1713	uint64_t IsPureVirtual : 1;
1714	LLVM_PREFERRED_TYPE(bool)
1715	uint64_t HasInheritedPrototype : 1;
1716	LLVM_PREFERRED_TYPE(bool)
1717	uint64_t HasWrittenPrototype : 1;
1718	LLVM_PREFERRED_TYPE(bool)
1719	uint64_t IsDeleted : 1;
1720	/// Used by CXXMethodDecl
1721	LLVM_PREFERRED_TYPE(bool)
1722	uint64_t IsTrivial : 1;
1723
1724	/// This flag indicates whether this function is trivial for the purpose of
1725	/// calls. This is meaningful only when this function is a copy/move
1726	/// constructor or a destructor.
1727	LLVM_PREFERRED_TYPE(bool)
1728	uint64_t IsTrivialForCall : 1;
1729
1730	LLVM_PREFERRED_TYPE(bool)
1731	uint64_t IsDefaulted : 1;
1732	LLVM_PREFERRED_TYPE(bool)
1733	uint64_t IsExplicitlyDefaulted : 1;
1734	LLVM_PREFERRED_TYPE(bool)
1735	uint64_t HasDefaultedOrDeletedInfo : 1;
1736
1737	/// For member functions of complete types, whether this is an ineligible
1738	/// special member function or an unselected destructor. See
1739	/// [class.mem.special].
1740	LLVM_PREFERRED_TYPE(bool)
1741	uint64_t IsIneligibleOrNotSelected : 1;
1742
1743	LLVM_PREFERRED_TYPE(bool)
1744	uint64_t HasImplicitReturnZero : 1;
1745	LLVM_PREFERRED_TYPE(bool)
1746	uint64_t IsLateTemplateParsed : 1;
1747
1748	/// Kind of contexpr specifier as defined by ConstexprSpecKind.
1749	LLVM_PREFERRED_TYPE(ConstexprSpecKind)
1750	uint64_t ConstexprKind : 2;
1751	LLVM_PREFERRED_TYPE(bool)
1752	uint64_t BodyContainsImmediateEscalatingExpression : 1;
1753
1754	LLVM_PREFERRED_TYPE(bool)
1755	uint64_t InstantiationIsPending : 1;
1756
1757	/// Indicates if the function uses __try.
1758	LLVM_PREFERRED_TYPE(bool)
1759	uint64_t UsesSEHTry : 1;
1760
1761	/// Indicates if the function was a definition
1762	/// but its body was skipped.
1763	LLVM_PREFERRED_TYPE(bool)
1764	uint64_t HasSkippedBody : 1;
1765
1766	/// Indicates if the function declaration will
1767	/// have a body, once we're done parsing it.
1768	LLVM_PREFERRED_TYPE(bool)
1769	uint64_t WillHaveBody : 1;
1770
1771	/// Indicates that this function is a multiversioned
1772	/// function using attribute 'target'.
1773	LLVM_PREFERRED_TYPE(bool)
1774	uint64_t IsMultiVersion : 1;
1775
1776	/// Only used by CXXDeductionGuideDecl. Indicates the kind
1777	/// of the Deduction Guide that is implicitly generated
1778	/// (used during overload resolution).
1779	LLVM_PREFERRED_TYPE(DeductionCandidate)
1780	uint64_t DeductionCandidateKind : 2;
1781
1782	/// Store the ODRHash after first calculation.
1783	LLVM_PREFERRED_TYPE(bool)
1784	uint64_t HasODRHash : 1;
1785
1786	/// Indicates if the function uses Floating Point Constrained Intrinsics
1787	LLVM_PREFERRED_TYPE(bool)
1788	uint64_t UsesFPIntrin : 1;
1789
1790	// Indicates this function is a constrained friend, where the constraint
1791	// refers to an enclosing template for hte purposes of [temp.friend]p9.
1792	LLVM_PREFERRED_TYPE(bool)
1793	uint64_t FriendConstraintRefersToEnclosingTemplate : 1;
1794	};
1795
1796	/// Number of inherited and non-inherited bits in FunctionDeclBitfields.
1797	enum { NumFunctionDeclBits = NumDeclContextBits + 31 };
1798
1799	/// Stores the bits used by CXXConstructorDecl. If modified
1800	/// NumCXXConstructorDeclBits and the accessor
1801	/// methods in CXXConstructorDecl should be updated appropriately.
1802	class CXXConstructorDeclBitfields {
1803	friend class CXXConstructorDecl;
1804	/// For the bits in FunctionDeclBitfields.
1805	LLVM_PREFERRED_TYPE(FunctionDeclBitfields)
1806	uint64_t : NumFunctionDeclBits;
1807
1808	/// 20 bits to fit in the remaining available space.
1809	/// Note that this makes CXXConstructorDeclBitfields take
1810	/// exactly 64 bits and thus the width of NumCtorInitializers
1811	/// will need to be shrunk if some bit is added to NumDeclContextBitfields,
1812	/// NumFunctionDeclBitfields or CXXConstructorDeclBitfields.
1813	uint64_t NumCtorInitializers : 17;
1814	LLVM_PREFERRED_TYPE(bool)
1815	uint64_t IsInheritingConstructor : 1;
1816
1817	/// Whether this constructor has a trail-allocated explicit specifier.
1818	LLVM_PREFERRED_TYPE(bool)
1819	uint64_t HasTrailingExplicitSpecifier : 1;
1820	/// If this constructor does't have a trail-allocated explicit specifier.
1821	/// Whether this constructor is explicit specified.
1822	LLVM_PREFERRED_TYPE(bool)
1823	uint64_t IsSimpleExplicit : 1;
1824	};
1825
1826	/// Number of inherited and non-inherited bits in CXXConstructorDeclBitfields.
1827	enum { NumCXXConstructorDeclBits = NumFunctionDeclBits + 20 };
1828
1829	/// Stores the bits used by ObjCMethodDecl.
1830	/// If modified NumObjCMethodDeclBits and the accessor
1831	/// methods in ObjCMethodDecl should be updated appropriately.
1832	class ObjCMethodDeclBitfields {
1833	friend class ObjCMethodDecl;
1834
1835	/// For the bits in DeclContextBitfields.
1836	LLVM_PREFERRED_TYPE(DeclContextBitfields)
1837	uint64_t : NumDeclContextBits;
1838
1839	/// The conventional meaning of this method; an ObjCMethodFamily.
1840	/// This is not serialized; instead, it is computed on demand and
1841	/// cached.
1842	LLVM_PREFERRED_TYPE(ObjCMethodFamily)
1843	mutable uint64_t Family : ObjCMethodFamilyBitWidth;
1844
1845	/// instance (true) or class (false) method.
1846	LLVM_PREFERRED_TYPE(bool)
1847	uint64_t IsInstance : 1;
1848	LLVM_PREFERRED_TYPE(bool)
1849	uint64_t IsVariadic : 1;
1850
1851	/// True if this method is the getter or setter for an explicit property.
1852	LLVM_PREFERRED_TYPE(bool)
1853	uint64_t IsPropertyAccessor : 1;
1854
1855	/// True if this method is a synthesized property accessor stub.
1856	LLVM_PREFERRED_TYPE(bool)
1857	uint64_t IsSynthesizedAccessorStub : 1;
1858
1859	/// Method has a definition.
1860	LLVM_PREFERRED_TYPE(bool)
1861	uint64_t IsDefined : 1;
1862
1863	/// Method redeclaration in the same interface.
1864	LLVM_PREFERRED_TYPE(bool)
1865	uint64_t IsRedeclaration : 1;
1866
1867	/// Is redeclared in the same interface.
1868	LLVM_PREFERRED_TYPE(bool)
1869	mutable uint64_t HasRedeclaration : 1;
1870
1871	/// \@required/\@optional
1872	LLVM_PREFERRED_TYPE(ObjCImplementationControl)
1873	uint64_t DeclImplementation : 2;
1874
1875	/// in, inout, etc.
1876	LLVM_PREFERRED_TYPE(Decl::ObjCDeclQualifier)
1877	uint64_t objcDeclQualifier : 7;
1878
1879	/// Indicates whether this method has a related result type.
1880	LLVM_PREFERRED_TYPE(bool)
1881	uint64_t RelatedResultType : 1;
1882
1883	/// Whether the locations of the selector identifiers are in a
1884	/// "standard" position, a enum SelectorLocationsKind.
1885	LLVM_PREFERRED_TYPE(SelectorLocationsKind)
1886	uint64_t SelLocsKind : 2;
1887
1888	/// Whether this method overrides any other in the class hierarchy.
1889	///
1890	/// A method is said to override any method in the class's
1891	/// base classes, its protocols, or its categories' protocols, that has
1892	/// the same selector and is of the same kind (class or instance).
1893	/// A method in an implementation is not considered as overriding the same
1894	/// method in the interface or its categories.
1895	LLVM_PREFERRED_TYPE(bool)
1896	uint64_t IsOverriding : 1;
1897
1898	/// Indicates if the method was a definition but its body was skipped.
1899	LLVM_PREFERRED_TYPE(bool)
1900	uint64_t HasSkippedBody : 1;
1901	};
1902
1903	/// Number of inherited and non-inherited bits in ObjCMethodDeclBitfields.
1904	enum { NumObjCMethodDeclBits = NumDeclContextBits + 24 };
1905
1906	/// Stores the bits used by ObjCContainerDecl.
1907	/// If modified NumObjCContainerDeclBits and the accessor
1908	/// methods in ObjCContainerDecl should be updated appropriately.
1909	class ObjCContainerDeclBitfields {
1910	friend class ObjCContainerDecl;
1911	/// For the bits in DeclContextBitfields
1912	LLVM_PREFERRED_TYPE(DeclContextBitfields)
1913	uint32_t : NumDeclContextBits;
1914
1915	// Not a bitfield but this saves space.
1916	// Note that ObjCContainerDeclBitfields is full.
1917	SourceLocation AtStart;
1918	};
1919
1920	/// Number of inherited and non-inherited bits in ObjCContainerDeclBitfields.
1921	/// Note that here we rely on the fact that SourceLocation is 32 bits
1922	/// wide. We check this with the static_assert in the ctor of DeclContext.
1923	enum { NumObjCContainerDeclBits = 64 };
1924
1925	/// Stores the bits used by LinkageSpecDecl.
1926	/// If modified NumLinkageSpecDeclBits and the accessor
1927	/// methods in LinkageSpecDecl should be updated appropriately.
1928	class LinkageSpecDeclBitfields {
1929	friend class LinkageSpecDecl;
1930	/// For the bits in DeclContextBitfields.
1931	LLVM_PREFERRED_TYPE(DeclContextBitfields)
1932	uint64_t : NumDeclContextBits;
1933
1934	/// The language for this linkage specification.
1935	LLVM_PREFERRED_TYPE(LinkageSpecLanguageIDs)
1936	uint64_t Language : 3;
1937
1938	/// True if this linkage spec has braces.
1939	/// This is needed so that hasBraces() returns the correct result while the
1940	/// linkage spec body is being parsed. Once RBraceLoc has been set this is
1941	/// not used, so it doesn't need to be serialized.
1942	LLVM_PREFERRED_TYPE(bool)
1943	uint64_t HasBraces : 1;
1944	};
1945
1946	/// Number of inherited and non-inherited bits in LinkageSpecDeclBitfields.
1947	enum { NumLinkageSpecDeclBits = NumDeclContextBits + 4 };
1948
1949	/// Stores the bits used by BlockDecl.
1950	/// If modified NumBlockDeclBits and the accessor
1951	/// methods in BlockDecl should be updated appropriately.
1952	class BlockDeclBitfields {
1953	friend class BlockDecl;
1954	/// For the bits in DeclContextBitfields.
1955	LLVM_PREFERRED_TYPE(DeclContextBitfields)
1956	uint64_t : NumDeclContextBits;
1957
1958	LLVM_PREFERRED_TYPE(bool)
1959	uint64_t IsVariadic : 1;
1960	LLVM_PREFERRED_TYPE(bool)
1961	uint64_t CapturesCXXThis : 1;
1962	LLVM_PREFERRED_TYPE(bool)
1963	uint64_t BlockMissingReturnType : 1;
1964	LLVM_PREFERRED_TYPE(bool)
1965	uint64_t IsConversionFromLambda : 1;
1966
1967	/// A bit that indicates this block is passed directly to a function as a
1968	/// non-escaping parameter.
1969	LLVM_PREFERRED_TYPE(bool)
1970	uint64_t DoesNotEscape : 1;
1971
1972	/// A bit that indicates whether it's possible to avoid coying this block to
1973	/// the heap when it initializes or is assigned to a local variable with
1974	/// automatic storage.
1975	LLVM_PREFERRED_TYPE(bool)
1976	uint64_t CanAvoidCopyToHeap : 1;
1977	};
1978
1979	/// Number of inherited and non-inherited bits in BlockDeclBitfields.
1980	enum { NumBlockDeclBits = NumDeclContextBits + 5 };
1981
1982	/// Pointer to the data structure used to lookup declarations
1983	/// within this context (or a DependentStoredDeclsMap if this is a
1984	/// dependent context). We maintain the invariant that, if the map
1985	/// contains an entry for a DeclarationName (and we haven't lazily
1986	/// omitted anything), then it contains all relevant entries for that
1987	/// name (modulo the hasExternalDecls() flag).
1988	mutable StoredDeclsMap *LookupPtr = nullptr;
1989
1990	protected:
1991	/// This anonymous union stores the bits belonging to DeclContext and classes
1992	/// deriving from it. The goal is to use otherwise wasted
1993	/// space in DeclContext to store data belonging to derived classes.
1994	/// The space saved is especially significient when pointers are aligned
1995	/// to 8 bytes. In this case due to alignment requirements we have a
1996	/// little less than 8 bytes free in DeclContext which we can use.
1997	/// We check that none of the classes in this union is larger than
1998	/// 8 bytes with static_asserts in the ctor of DeclContext.
1999	union {
2000	DeclContextBitfields DeclContextBits;
2001	TagDeclBitfields TagDeclBits;
2002	EnumDeclBitfields EnumDeclBits;
2003	RecordDeclBitfields RecordDeclBits;
2004	OMPDeclareReductionDeclBitfields OMPDeclareReductionDeclBits;
2005	FunctionDeclBitfields FunctionDeclBits;
2006	CXXConstructorDeclBitfields CXXConstructorDeclBits;
2007	ObjCMethodDeclBitfields ObjCMethodDeclBits;
2008	ObjCContainerDeclBitfields ObjCContainerDeclBits;
2009	LinkageSpecDeclBitfields LinkageSpecDeclBits;
2010	BlockDeclBitfields BlockDeclBits;
2011
2012	static_assert(sizeof(DeclContextBitfields) <= 8,
2013	"DeclContextBitfields is larger than 8 bytes!");
2014	static_assert(sizeof(TagDeclBitfields) <= 8,
2015	"TagDeclBitfields is larger than 8 bytes!");
2016	static_assert(sizeof(EnumDeclBitfields) <= 8,
2017	"EnumDeclBitfields is larger than 8 bytes!");
2018	static_assert(sizeof(RecordDeclBitfields) <= 8,
2019	"RecordDeclBitfields is larger than 8 bytes!");
2020	static_assert(sizeof(OMPDeclareReductionDeclBitfields) <= 8,
2021	"OMPDeclareReductionDeclBitfields is larger than 8 bytes!");
2022	static_assert(sizeof(FunctionDeclBitfields) <= 8,
2023	"FunctionDeclBitfields is larger than 8 bytes!");
2024	static_assert(sizeof(CXXConstructorDeclBitfields) <= 8,
2025	"CXXConstructorDeclBitfields is larger than 8 bytes!");
2026	static_assert(sizeof(ObjCMethodDeclBitfields) <= 8,
2027	"ObjCMethodDeclBitfields is larger than 8 bytes!");
2028	static_assert(sizeof(ObjCContainerDeclBitfields) <= 8,
2029	"ObjCContainerDeclBitfields is larger than 8 bytes!");
2030	static_assert(sizeof(LinkageSpecDeclBitfields) <= 8,
2031	"LinkageSpecDeclBitfields is larger than 8 bytes!");
2032	static_assert(sizeof(BlockDeclBitfields) <= 8,
2033	"BlockDeclBitfields is larger than 8 bytes!");
2034	};
2035
2036	/// FirstDecl - The first declaration stored within this declaration
2037	/// context.
2038	mutable Decl *FirstDecl = nullptr;
2039
2040	/// LastDecl - The last declaration stored within this declaration
2041	/// context. FIXME: We could probably cache this value somewhere
2042	/// outside of the DeclContext, to reduce the size of DeclContext by
2043	/// another pointer.
2044	mutable Decl *LastDecl = nullptr;
2045
2046	/// Build up a chain of declarations.
2047	///
2048	/// \returns the first/last pair of declarations.
2049	static std::pair<Decl *, Decl *>
2050	BuildDeclChain(ArrayRef<Decl*> Decls, bool FieldsAlreadyLoaded);
2051
2052	DeclContext(Decl::Kind K);
2053
2054	public:
2055	~DeclContext();
2056
2057	// For use when debugging; hasValidDeclKind() will always return true for
2058	// a correctly constructed object within its lifetime.
2059	bool hasValidDeclKind() const;
2060
2061	Decl::Kind getDeclKind() const {
2062	return static_cast<Decl::Kind>(DeclContextBits.DeclKind);
2063	}
2064
2065	const char *getDeclKindName() const;
2066
2067	/// getParent - Returns the containing DeclContext.
2068	DeclContext *getParent() {
2069	return cast<Decl>(Val: this)->getDeclContext();
2070	}
2071	const DeclContext *getParent() const {
2072	return const_cast<DeclContext*>(this)->getParent();
2073	}
2074
2075	/// getLexicalParent - Returns the containing lexical DeclContext. May be
2076	/// different from getParent, e.g.:
2077	///
2078	/// namespace A {
2079	/// struct S;
2080	/// }
2081	/// struct A::S {}; // getParent() == namespace 'A'
2082	/// // getLexicalParent() == translation unit
2083	///
2084	DeclContext *getLexicalParent() {
2085	return cast<Decl>(Val: this)->getLexicalDeclContext();
2086	}
2087	const DeclContext *getLexicalParent() const {
2088	return const_cast<DeclContext*>(this)->getLexicalParent();
2089	}
2090
2091	DeclContext *getLookupParent();
2092
2093	const DeclContext *getLookupParent() const {
2094	return const_cast<DeclContext*>(this)->getLookupParent();
2095	}
2096
2097	ASTContext &getParentASTContext() const {
2098	return cast<Decl>(Val: this)->getASTContext();
2099	}
2100
2101	bool isClosure() const { return getDeclKind() == Decl::Block; }
2102
2103	/// Return this DeclContext if it is a BlockDecl. Otherwise, return the
2104	/// innermost enclosing BlockDecl or null if there are no enclosing blocks.
2105	const BlockDecl *getInnermostBlockDecl() const;
2106
2107	bool isObjCContainer() const {
2108	switch (getDeclKind()) {
2109	case Decl::ObjCCategory:
2110	case Decl::ObjCCategoryImpl:
2111	case Decl::ObjCImplementation:
2112	case Decl::ObjCInterface:
2113	case Decl::ObjCProtocol:
2114	return true;
2115	default:
2116	return false;
2117	}
2118	}
2119
2120	bool isFunctionOrMethod() const {
2121	switch (getDeclKind()) {
2122	case Decl::Block:
2123	case Decl::Captured:
2124	case Decl::ObjCMethod:
2125	case Decl::TopLevelStmt:
2126	return true;
2127	default:
2128	return getDeclKind() >= Decl::firstFunction &&
2129	getDeclKind() <= Decl::lastFunction;
2130	}
2131	}
2132
2133	/// Test whether the context supports looking up names.
2134	bool isLookupContext() const {
2135	return !isFunctionOrMethod() && getDeclKind() != Decl::LinkageSpec &&
2136	getDeclKind() != Decl::Export;
2137	}
2138
2139	bool isFileContext() const {
2140	return getDeclKind() == Decl::TranslationUnit ||
2141	getDeclKind() == Decl::Namespace;
2142	}
2143
2144	bool isTranslationUnit() const {
2145	return getDeclKind() == Decl::TranslationUnit;
2146	}
2147
2148	bool isRecord() const {
2149	return getDeclKind() >= Decl::firstRecord &&
2150	getDeclKind() <= Decl::lastRecord;
2151	}
2152
2153	bool isNamespace() const { return getDeclKind() == Decl::Namespace; }
2154
2155	bool isStdNamespace() const;
2156
2157	bool isInlineNamespace() const;
2158
2159	/// Determines whether this context is dependent on a
2160	/// template parameter.
2161	bool isDependentContext() const;
2162
2163	/// isTransparentContext - Determines whether this context is a
2164	/// "transparent" context, meaning that the members declared in this
2165	/// context are semantically declared in the nearest enclosing
2166	/// non-transparent (opaque) context but are lexically declared in
2167	/// this context. For example, consider the enumerators of an
2168	/// enumeration type:
2169	/// @code
2170	/// enum E {
2171	/// Val1
2172	/// };
2173	/// @endcode
2174	/// Here, E is a transparent context, so its enumerator (Val1) will
2175	/// appear (semantically) that it is in the same context of E.
2176	/// Examples of transparent contexts include: enumerations (except for
2177	/// C++0x scoped enums), C++ linkage specifications and export declaration.
2178	bool isTransparentContext() const;
2179
2180	/// Determines whether this context or some of its ancestors is a
2181	/// linkage specification context that specifies C linkage.
2182	bool isExternCContext() const;
2183
2184	/// Retrieve the nearest enclosing C linkage specification context.
2185	const LinkageSpecDecl *getExternCContext() const;
2186
2187	/// Determines whether this context or some of its ancestors is a
2188	/// linkage specification context that specifies C++ linkage.
2189	bool isExternCXXContext() const;
2190
2191	/// Determine whether this declaration context is equivalent
2192	/// to the declaration context DC.
2193	bool Equals(const DeclContext *DC) const {
2194	return DC && this->getPrimaryContext() == DC->getPrimaryContext();
2195	}
2196
2197	/// Determine whether this declaration context encloses the
2198	/// declaration context DC.
2199	bool Encloses(const DeclContext *DC) const;
2200
2201	/// Find the nearest non-closure ancestor of this context,
2202	/// i.e. the innermost semantic parent of this context which is not
2203	/// a closure. A context may be its own non-closure ancestor.
2204	Decl *getNonClosureAncestor();
2205	const Decl *getNonClosureAncestor() const {
2206	return const_cast<DeclContext*>(this)->getNonClosureAncestor();
2207	}
2208
2209	// Retrieve the nearest context that is not a transparent context.
2210	DeclContext *getNonTransparentContext();
2211	const DeclContext *getNonTransparentContext() const {
2212	return const_cast<DeclContext *>(this)->getNonTransparentContext();
2213	}
2214
2215	/// getPrimaryContext - There may be many different
2216	/// declarations of the same entity (including forward declarations
2217	/// of classes, multiple definitions of namespaces, etc.), each with
2218	/// a different set of declarations. This routine returns the
2219	/// "primary" DeclContext structure, which will contain the
2220	/// information needed to perform name lookup into this context.
2221	DeclContext *getPrimaryContext();
2222	const DeclContext *getPrimaryContext() const {
2223	return const_cast<DeclContext*>(this)->getPrimaryContext();
2224	}
2225
2226	/// getRedeclContext - Retrieve the context in which an entity conflicts with
2227	/// other entities of the same name, or where it is a redeclaration if the
2228	/// two entities are compatible. This skips through transparent contexts.
2229	DeclContext *getRedeclContext();
2230	const DeclContext *getRedeclContext() const {
2231	return const_cast<DeclContext *>(this)->getRedeclContext();
2232	}
2233
2234	/// Retrieve the nearest enclosing namespace context.
2235	DeclContext *getEnclosingNamespaceContext();
2236	const DeclContext *getEnclosingNamespaceContext() const {
2237	return const_cast<DeclContext *>(this)->getEnclosingNamespaceContext();
2238	}
2239
2240	/// Retrieve the outermost lexically enclosing record context.
2241	RecordDecl *getOuterLexicalRecordContext();
2242	const RecordDecl *getOuterLexicalRecordContext() const {
2243	return const_cast<DeclContext *>(this)->getOuterLexicalRecordContext();
2244	}
2245
2246	/// Test if this context is part of the enclosing namespace set of
2247	/// the context NS, as defined in C++0x [namespace.def]p9. If either context
2248	/// isn't a namespace, this is equivalent to Equals().
2249	///
2250	/// The enclosing namespace set of a namespace is the namespace and, if it is
2251	/// inline, its enclosing namespace, recursively.
2252	bool InEnclosingNamespaceSetOf(const DeclContext *NS) const;
2253
2254	/// Collects all of the declaration contexts that are semantically
2255	/// connected to this declaration context.
2256	///
2257	/// For declaration contexts that have multiple semantically connected but
2258	/// syntactically distinct contexts, such as C++ namespaces, this routine
2259	/// retrieves the complete set of such declaration contexts in source order.
2260	/// For example, given:
2261	///
2262	/// \code
2263	/// namespace N {
2264	/// int x;
2265	/// }
2266	/// namespace N {
2267	/// int y;
2268	/// }
2269	/// \endcode
2270	///
2271	/// The \c Contexts parameter will contain both definitions of N.
2272	///
2273	/// \param Contexts Will be cleared and set to the set of declaration
2274	/// contexts that are semanticaly connected to this declaration context,
2275	/// in source order, including this context (which may be the only result,
2276	/// for non-namespace contexts).
2277	void collectAllContexts(SmallVectorImpl<DeclContext *> &Contexts);
2278
2279	/// decl_iterator - Iterates through the declarations stored
2280	/// within this context.
2281	class decl_iterator {
2282	/// Current - The current declaration.
2283	Decl *Current = nullptr;
2284
2285	public:
2286	using value_type = Decl *;
2287	using reference = const value_type &;
2288	using pointer = const value_type *;
2289	using iterator_category = std::forward_iterator_tag;
2290	using difference_type = std::ptrdiff_t;
2291
2292	decl_iterator() = default;
2293	explicit decl_iterator(Decl *C) : Current(C) {}
2294
2295	reference operator*() const { return Current; }
2296
2297	// This doesn't meet the iterator requirements, but it's convenient
2298	value_type operator->() const { return Current; }
2299
2300	decl_iterator& operator++() {
2301	Current = Current->getNextDeclInContext();
2302	return *this;
2303	}
2304
2305	decl_iterator operator++(int) {
2306	decl_iterator tmp(*this);
2307	++(*this);
2308	return tmp;
2309	}
2310
2311	friend bool operator==(decl_iterator x, decl_iterator y) {
2312	return x.Current == y.Current;
2313	}
2314
2315	friend bool operator!=(decl_iterator x, decl_iterator y) {
2316	return x.Current != y.Current;
2317	}
2318	};
2319
2320	using decl_range = llvm::iterator_range<decl_iterator>;
2321
2322	/// decls_begin/decls_end - Iterate over the declarations stored in
2323	/// this context.
2324	decl_range decls() const { return decl_range(decls_begin(), decls_end()); }
2325	decl_iterator decls_begin() const;
2326	decl_iterator decls_end() const { return decl_iterator(); }
2327	bool decls_empty() const;
2328
2329	/// noload_decls_begin/end - Iterate over the declarations stored in this
2330	/// context that are currently loaded; don't attempt to retrieve anything
2331	/// from an external source.
2332	decl_range noload_decls() const {
2333	return decl_range(noload_decls_begin(), noload_decls_end());
2334	}
2335	decl_iterator noload_decls_begin() const { return decl_iterator(FirstDecl); }
2336	decl_iterator noload_decls_end() const { return decl_iterator(); }
2337
2338	/// specific_decl_iterator - Iterates over a subrange of
2339	/// declarations stored in a DeclContext, providing only those that
2340	/// are of type SpecificDecl (or a class derived from it). This
2341	/// iterator is used, for example, to provide iteration over just
2342	/// the fields within a RecordDecl (with SpecificDecl = FieldDecl).
2343	template<typename SpecificDecl>
2344	class specific_decl_iterator {
2345	/// Current - The current, underlying declaration iterator, which
2346	/// will either be NULL or will point to a declaration of
2347	/// type SpecificDecl.
2348	DeclContext::decl_iterator Current;
2349
2350	/// SkipToNextDecl - Advances the current position up to the next
2351	/// declaration of type SpecificDecl that also meets the criteria
2352	/// required by Acceptable.
2353	void SkipToNextDecl() {
2354	while (*Current && !isa<SpecificDecl>(*Current))
2355	++Current;
2356	}
2357
2358	public:
2359	using value_type = SpecificDecl *;
2360	// TODO: Add reference and pointer types (with some appropriate proxy type)
2361	// if we ever have a need for them.
2362	using reference = void;
2363	using pointer = void;
2364	using difference_type =
2365	std::iterator_traits<DeclContext::decl_iterator>::difference_type;
2366	using iterator_category = std::forward_iterator_tag;
2367
2368	specific_decl_iterator() = default;
2369
2370	/// specific_decl_iterator - Construct a new iterator over a
2371	/// subset of the declarations the range [C,
2372	/// end-of-declarations). If A is non-NULL, it is a pointer to a
2373	/// member function of SpecificDecl that should return true for
2374	/// all of the SpecificDecl instances that will be in the subset
2375	/// of iterators. For example, if you want Objective-C instance
2376	/// methods, SpecificDecl will be ObjCMethodDecl and A will be
2377	/// &ObjCMethodDecl::isInstanceMethod.
2378	explicit specific_decl_iterator(DeclContext::decl_iterator C) : Current(C) {
2379	SkipToNextDecl();
2380	}
2381
2382	value_type operator*() const { return cast<SpecificDecl>(*Current); }
2383
2384	// This doesn't meet the iterator requirements, but it's convenient
2385	value_type operator->() const { return **this; }
2386
2387	specific_decl_iterator& operator++() {
2388	++Current;
2389	SkipToNextDecl();
2390	return *this;
2391	}
2392
2393	specific_decl_iterator operator++(int) {
2394	specific_decl_iterator tmp(*this);
2395	++(*this);
2396	return tmp;
2397	}
2398
2399	friend bool operator==(const specific_decl_iterator& x,
2400	const specific_decl_iterator& y) {
2401	return x.Current == y.Current;
2402	}
2403
2404	friend bool operator!=(const specific_decl_iterator& x,
2405	const specific_decl_iterator& y) {
2406	return x.Current != y.Current;
2407	}
2408	};
2409
2410	/// Iterates over a filtered subrange of declarations stored
2411	/// in a DeclContext.
2412	///
2413	/// This iterator visits only those declarations that are of type
2414	/// SpecificDecl (or a class derived from it) and that meet some
2415	/// additional run-time criteria. This iterator is used, for
2416	/// example, to provide access to the instance methods within an
2417	/// Objective-C interface (with SpecificDecl = ObjCMethodDecl and
2418	/// Acceptable = ObjCMethodDecl::isInstanceMethod).
2419	template<typename SpecificDecl, bool (SpecificDecl::*Acceptable)() const>
2420	class filtered_decl_iterator {
2421	/// Current - The current, underlying declaration iterator, which
2422	/// will either be NULL or will point to a declaration of
2423	/// type SpecificDecl.
2424	DeclContext::decl_iterator Current;
2425
2426	/// SkipToNextDecl - Advances the current position up to the next
2427	/// declaration of type SpecificDecl that also meets the criteria
2428	/// required by Acceptable.
2429	void SkipToNextDecl() {
2430	while (*Current &&
2431	(!isa<SpecificDecl>(*Current) ||
2432	(Acceptable && !(cast<SpecificDecl>(*Current)->*Acceptable)())))
2433	++Current;
2434	}
2435
2436	public:
2437	using value_type = SpecificDecl *;
2438	// TODO: Add reference and pointer types (with some appropriate proxy type)
2439	// if we ever have a need for them.
2440	using reference = void;
2441	using pointer = void;
2442	using difference_type =
2443	std::iterator_traits<DeclContext::decl_iterator>::difference_type;
2444	using iterator_category = std::forward_iterator_tag;
2445
2446	filtered_decl_iterator() = default;
2447
2448	/// filtered_decl_iterator - Construct a new iterator over a
2449	/// subset of the declarations the range [C,
2450	/// end-of-declarations). If A is non-NULL, it is a pointer to a
2451	/// member function of SpecificDecl that should return true for
2452	/// all of the SpecificDecl instances that will be in the subset
2453	/// of iterators. For example, if you want Objective-C instance
2454	/// methods, SpecificDecl will be ObjCMethodDecl and A will be
2455	/// &ObjCMethodDecl::isInstanceMethod.
2456	explicit filtered_decl_iterator(DeclContext::decl_iterator C) : Current(C) {
2457	SkipToNextDecl();
2458	}
2459
2460	value_type operator*() const { return cast<SpecificDecl>(*Current); }
2461	value_type operator->() const { return cast<SpecificDecl>(*Current); }
2462
2463	filtered_decl_iterator& operator++() {
2464	++Current;
2465	SkipToNextDecl();
2466	return *this;
2467	}
2468
2469	filtered_decl_iterator operator++(int) {
2470	filtered_decl_iterator tmp(*this);
2471	++(*this);
2472	return tmp;
2473	}
2474
2475	friend bool operator==(const filtered_decl_iterator& x,
2476	const filtered_decl_iterator& y) {
2477	return x.Current == y.Current;
2478	}
2479
2480	friend bool operator!=(const filtered_decl_iterator& x,
2481	const filtered_decl_iterator& y) {
2482	return x.Current != y.Current;
2483	}
2484	};
2485
2486	/// Add the declaration D into this context.
2487	///
2488	/// This routine should be invoked when the declaration D has first
2489	/// been declared, to place D into the context where it was
2490	/// (lexically) defined. Every declaration must be added to one
2491	/// (and only one!) context, where it can be visited via
2492	/// [decls_begin(), decls_end()). Once a declaration has been added
2493	/// to its lexical context, the corresponding DeclContext owns the
2494	/// declaration.
2495	///
2496	/// If D is also a NamedDecl, it will be made visible within its
2497	/// semantic context via makeDeclVisibleInContext.
2498	void addDecl(Decl *D);
2499
2500	/// Add the declaration D into this context, but suppress
2501	/// searches for external declarations with the same name.
2502	///
2503	/// Although analogous in function to addDecl, this removes an
2504	/// important check. This is only useful if the Decl is being
2505	/// added in response to an external search; in all other cases,
2506	/// addDecl() is the right function to use.
2507	/// See the ASTImporter for use cases.
2508	void addDeclInternal(Decl *D);
2509
2510	/// Add the declaration D to this context without modifying
2511	/// any lookup tables.
2512	///
2513	/// This is useful for some operations in dependent contexts where
2514	/// the semantic context might not be dependent; this basically
2515	/// only happens with friends.
2516	void addHiddenDecl(Decl *D);
2517
2518	/// Removes a declaration from this context.
2519	void removeDecl(Decl *D);
2520
2521	/// Checks whether a declaration is in this context.
2522	bool containsDecl(Decl *D) const;
2523
2524	/// Checks whether a declaration is in this context.
2525	/// This also loads the Decls from the external source before the check.
2526	bool containsDeclAndLoad(Decl *D) const;
2527
2528	using lookup_result = DeclContextLookupResult;
2529	using lookup_iterator = lookup_result::iterator;
2530
2531	/// lookup - Find the declarations (if any) with the given Name in
2532	/// this context. Returns a range of iterators that contains all of
2533	/// the declarations with this name, with object, function, member,
2534	/// and enumerator names preceding any tag name. Note that this
2535	/// routine will not look into parent contexts.
2536	lookup_result lookup(DeclarationName Name) const;
2537
2538	/// Find the declarations with the given name that are visible
2539	/// within this context; don't attempt to retrieve anything from an
2540	/// external source.
2541	lookup_result noload_lookup(DeclarationName Name);
2542
2543	/// A simplistic name lookup mechanism that performs name lookup
2544	/// into this declaration context without consulting the external source.
2545	///
2546	/// This function should almost never be used, because it subverts the
2547	/// usual relationship between a DeclContext and the external source.
2548	/// See the ASTImporter for the (few, but important) use cases.
2549	///
2550	/// FIXME: This is very inefficient; replace uses of it with uses of
2551	/// noload_lookup.
2552	void localUncachedLookup(DeclarationName Name,
2553	SmallVectorImpl<NamedDecl *> &Results);
2554
2555	/// Makes a declaration visible within this context.
2556	///
2557	/// This routine makes the declaration D visible to name lookup
2558	/// within this context and, if this is a transparent context,
2559	/// within its parent contexts up to the first enclosing
2560	/// non-transparent context. Making a declaration visible within a
2561	/// context does not transfer ownership of a declaration, and a
2562	/// declaration can be visible in many contexts that aren't its
2563	/// lexical context.
2564	///
2565	/// If D is a redeclaration of an existing declaration that is
2566	/// visible from this context, as determined by
2567	/// NamedDecl::declarationReplaces, the previous declaration will be
2568	/// replaced with D.
2569	void makeDeclVisibleInContext(NamedDecl *D);
2570
2571	/// all_lookups_iterator - An iterator that provides a view over the results
2572	/// of looking up every possible name.
2573	class all_lookups_iterator;
2574
2575	using lookups_range = llvm::iterator_range<all_lookups_iterator>;
2576
2577	lookups_range lookups() const;
2578	// Like lookups(), but avoids loading external declarations.
2579	// If PreserveInternalState, avoids building lookup data structures too.
2580	lookups_range noload_lookups(bool PreserveInternalState) const;
2581
2582	/// Iterators over all possible lookups within this context.
2583	all_lookups_iterator lookups_begin() const;
2584	all_lookups_iterator lookups_end() const;
2585
2586	/// Iterators over all possible lookups within this context that are
2587	/// currently loaded; don't attempt to retrieve anything from an external
2588	/// source.
2589	all_lookups_iterator noload_lookups_begin() const;
2590	all_lookups_iterator noload_lookups_end() const;
2591
2592	struct udir_iterator;
2593
2594	using udir_iterator_base =
2595	llvm::iterator_adaptor_base<udir_iterator, lookup_iterator,
2596	typename lookup_iterator::iterator_category,
2597	UsingDirectiveDecl *>;
2598
2599	struct udir_iterator : udir_iterator_base {
2600	udir_iterator(lookup_iterator I) : udir_iterator_base(I) {}
2601
2602	UsingDirectiveDecl *operator*() const;
2603	};
2604
2605	using udir_range = llvm::iterator_range<udir_iterator>;
2606
2607	udir_range using_directives() const;
2608
2609	// These are all defined in DependentDiagnostic.h.
2610	class ddiag_iterator;
2611
2612	using ddiag_range = llvm::iterator_range<DeclContext::ddiag_iterator>;
2613
2614	inline ddiag_range ddiags() const;
2615
2616	// Low-level accessors
2617
2618	/// Mark that there are external lexical declarations that we need
2619	/// to include in our lookup table (and that are not available as external
2620	/// visible lookups). These extra lookup results will be found by walking
2621	/// the lexical declarations of this context. This should be used only if
2622	/// setHasExternalLexicalStorage() has been called on any decl context for
2623	/// which this is the primary context.
2624	void setMustBuildLookupTable() {
2625	assert(this == getPrimaryContext() &&
2626	"should only be called on primary context");
2627	DeclContextBits.HasLazyExternalLexicalLookups = true;
2628	}
2629
2630	/// Retrieve the internal representation of the lookup structure.
2631	/// This may omit some names if we are lazily building the structure.
2632	StoredDeclsMap *getLookupPtr() const { return LookupPtr; }
2633
2634	/// Ensure the lookup structure is fully-built and return it.
2635	StoredDeclsMap *buildLookup();
2636
2637	/// Whether this DeclContext has external storage containing
2638	/// additional declarations that are lexically in this context.
2639	bool hasExternalLexicalStorage() const {
2640	return DeclContextBits.ExternalLexicalStorage;
2641	}
2642
2643	/// State whether this DeclContext has external storage for
2644	/// declarations lexically in this context.
2645	void setHasExternalLexicalStorage(bool ES = true) const {
2646	DeclContextBits.ExternalLexicalStorage = ES;
2647	}
2648
2649	/// Whether this DeclContext has external storage containing
2650	/// additional declarations that are visible in this context.
2651	bool hasExternalVisibleStorage() const {
2652	return DeclContextBits.ExternalVisibleStorage;
2653	}
2654
2655	/// State whether this DeclContext has external storage for
2656	/// declarations visible in this context.
2657	void setHasExternalVisibleStorage(bool ES = true) const {
2658	DeclContextBits.ExternalVisibleStorage = ES;
2659	if (ES && LookupPtr)
2660	DeclContextBits.NeedToReconcileExternalVisibleStorage = true;
2661	}
2662
2663	/// Determine whether the given declaration is stored in the list of
2664	/// declarations lexically within this context.
2665	bool isDeclInLexicalTraversal(const Decl *D) const {
2666	return D && (D->NextInContextAndBits.getPointer() || D == FirstDecl ||
2667	D == LastDecl);
2668	}
2669
2670	void setUseQualifiedLookup(bool use = true) const {
2671	DeclContextBits.UseQualifiedLookup = use;
2672	}
2673
2674	bool shouldUseQualifiedLookup() const {
2675	return DeclContextBits.UseQualifiedLookup;
2676	}
2677
2678	static bool classof(const Decl *D);
2679	static bool classof(const DeclContext *D) { return true; }
2680
2681	void dumpAsDecl() const;
2682	void dumpAsDecl(const ASTContext *Ctx) const;
2683	void dumpDeclContext() const;
2684	void dumpLookups() const;
2685	void dumpLookups(llvm::raw_ostream &OS, bool DumpDecls = false,
2686	bool Deserialize = false) const;
2687
2688	private:
2689	/// Whether this declaration context has had externally visible
2690	/// storage added since the last lookup. In this case, \c LookupPtr's
2691	/// invariant may not hold and needs to be fixed before we perform
2692	/// another lookup.
2693	bool hasNeedToReconcileExternalVisibleStorage() const {
2694	return DeclContextBits.NeedToReconcileExternalVisibleStorage;
2695	}
2696
2697	/// State that this declaration context has had externally visible
2698	/// storage added since the last lookup. In this case, \c LookupPtr's
2699	/// invariant may not hold and needs to be fixed before we perform
2700	/// another lookup.
2701	void setNeedToReconcileExternalVisibleStorage(bool Need = true) const {
2702	DeclContextBits.NeedToReconcileExternalVisibleStorage = Need;
2703	}
2704
2705	/// If \c true, this context may have local lexical declarations
2706	/// that are missing from the lookup table.
2707	bool hasLazyLocalLexicalLookups() const {
2708	return DeclContextBits.HasLazyLocalLexicalLookups;
2709	}
2710
2711	/// If \c true, this context may have local lexical declarations
2712	/// that are missing from the lookup table.
2713	void setHasLazyLocalLexicalLookups(bool HasLLLL = true) const {
2714	DeclContextBits.HasLazyLocalLexicalLookups = HasLLLL;
2715	}
2716
2717	/// If \c true, the external source may have lexical declarations
2718	/// that are missing from the lookup table.
2719	bool hasLazyExternalLexicalLookups() const {
2720	return DeclContextBits.HasLazyExternalLexicalLookups;
2721	}
2722
2723	/// If \c true, the external source may have lexical declarations
2724	/// that are missing from the lookup table.
2725	void setHasLazyExternalLexicalLookups(bool HasLELL = true) const {
2726	DeclContextBits.HasLazyExternalLexicalLookups = HasLELL;
2727	}
2728
2729	void reconcileExternalVisibleStorage() const;
2730	bool LoadLexicalDeclsFromExternalStorage() const;
2731
2732	StoredDeclsMap *CreateStoredDeclsMap(ASTContext &C) const;
2733
2734	void loadLazyLocalLexicalLookups();
2735	void buildLookupImpl(DeclContext *DCtx, bool Internal);
2736	void makeDeclVisibleInContextWithFlags(NamedDecl *D, bool Internal,
2737	bool Rediscoverable);
2738	void makeDeclVisibleInContextImpl(NamedDecl *D, bool Internal);
2739	};
2740
2741	inline bool Decl::isTemplateParameter() const {
2742	return getKind() == TemplateTypeParm || getKind() == NonTypeTemplateParm ||
2743	getKind() == TemplateTemplateParm;
2744	}
2745
2746	// Specialization selected when ToTy is not a known subclass of DeclContext.
2747	template <class ToTy,
2748	bool IsKnownSubtype = ::std::is_base_of<DeclContext, ToTy>::value>
2749	struct cast_convert_decl_context {
2750	static const ToTy *doit(const DeclContext *Val) {
2751	return static_cast<const ToTy*>(Decl::castFromDeclContext(Val));
2752	}
2753
2754	static ToTy *doit(DeclContext *Val) {
2755	return static_cast<ToTy*>(Decl::castFromDeclContext(Val));
2756	}
2757	};
2758
2759	// Specialization selected when ToTy is a known subclass of DeclContext.
2760	template <class ToTy>
2761	struct cast_convert_decl_context<ToTy, true> {
2762	static const ToTy *doit(const DeclContext *Val) {
2763	return static_cast<const ToTy*>(Val);
2764	}
2765
2766	static ToTy *doit(DeclContext *Val) {
2767	return static_cast<ToTy*>(Val);
2768	}
2769	};
2770
2771	} // namespace clang
2772
2773	namespace llvm {
2774
2775	/// isa<T>(DeclContext*)
2776	template <typename To>
2777	struct isa_impl<To, ::clang::DeclContext> {
2778	static bool doit(const ::clang::DeclContext &Val) {
2779	return To::classofKind(Val.getDeclKind());
2780	}
2781	};
2782
2783	/// cast<T>(DeclContext*)
2784	template<class ToTy>
2785	struct cast_convert_val<ToTy,
2786	const ::clang::DeclContext,const ::clang::DeclContext> {
2787	static const ToTy &doit(const ::clang::DeclContext &Val) {
2788	return *::clang::cast_convert_decl_context<ToTy>::doit(&Val);
2789	}
2790	};
2791
2792	template<class ToTy>
2793	struct cast_convert_val<ToTy, ::clang::DeclContext, ::clang::DeclContext> {
2794	static ToTy &doit(::clang::DeclContext &Val) {
2795	return *::clang::cast_convert_decl_context<ToTy>::doit(&Val);
2796	}
2797	};
2798
2799	template<class ToTy>
2800	struct cast_convert_val<ToTy,
2801	const ::clang::DeclContext*, const ::clang::DeclContext*> {
2802	static const ToTy *doit(const ::clang::DeclContext *Val) {
2803	return ::clang::cast_convert_decl_context<ToTy>::doit(Val);
2804	}
2805	};
2806
2807	template<class ToTy>
2808	struct cast_convert_val<ToTy, ::clang::DeclContext*, ::clang::DeclContext*> {
2809	static ToTy *doit(::clang::DeclContext *Val) {
2810	return ::clang::cast_convert_decl_context<ToTy>::doit(Val);
2811	}
2812	};
2813
2814	/// Implement cast_convert_val for Decl -> DeclContext conversions.
2815	template<class FromTy>
2816	struct cast_convert_val< ::clang::DeclContext, FromTy, FromTy> {
2817	static ::clang::DeclContext &doit(const FromTy &Val) {
2818	return *FromTy::castToDeclContext(&Val);
2819	}
2820	};
2821
2822	template<class FromTy>
2823	struct cast_convert_val< ::clang::DeclContext, FromTy*, FromTy*> {
2824	static ::clang::DeclContext *doit(const FromTy *Val) {
2825	return FromTy::castToDeclContext(Val);
2826	}
2827	};
2828
2829	template<class FromTy>
2830	struct cast_convert_val< const ::clang::DeclContext, FromTy, FromTy> {
2831	static const ::clang::DeclContext &doit(const FromTy &Val) {
2832	return *FromTy::castToDeclContext(&Val);
2833	}
2834	};
2835
2836	template<class FromTy>
2837	struct cast_convert_val< const ::clang::DeclContext, FromTy*, FromTy*> {
2838	static const ::clang::DeclContext *doit(const FromTy *Val) {
2839	return FromTy::castToDeclContext(Val);
2840	}
2841	};
2842
2843	} // namespace llvm
2844
2845	#endif // LLVM_CLANG_AST_DECLBASE_H
2846