xref: /freebsd/contrib/llvm-project/clang/lib/AST/DeclCXX.cpp (revision d56accc7c3dcc897489b6a07834763a03b9f3d68)
1 //===- DeclCXX.cpp - C++ Declaration AST Node Implementation --------------===//
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 implements the C++ related Decl classes.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/AST/DeclCXX.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/ASTLambda.h"
16 #include "clang/AST/ASTMutationListener.h"
17 #include "clang/AST/ASTUnresolvedSet.h"
18 #include "clang/AST/Attr.h"
19 #include "clang/AST/CXXInheritance.h"
20 #include "clang/AST/DeclBase.h"
21 #include "clang/AST/DeclTemplate.h"
22 #include "clang/AST/DeclarationName.h"
23 #include "clang/AST/Expr.h"
24 #include "clang/AST/ExprCXX.h"
25 #include "clang/AST/LambdaCapture.h"
26 #include "clang/AST/NestedNameSpecifier.h"
27 #include "clang/AST/ODRHash.h"
28 #include "clang/AST/Type.h"
29 #include "clang/AST/TypeLoc.h"
30 #include "clang/AST/UnresolvedSet.h"
31 #include "clang/Basic/Diagnostic.h"
32 #include "clang/Basic/IdentifierTable.h"
33 #include "clang/Basic/LLVM.h"
34 #include "clang/Basic/LangOptions.h"
35 #include "clang/Basic/OperatorKinds.h"
36 #include "clang/Basic/PartialDiagnostic.h"
37 #include "clang/Basic/SourceLocation.h"
38 #include "clang/Basic/Specifiers.h"
39 #include "llvm/ADT/None.h"
40 #include "llvm/ADT/SmallPtrSet.h"
41 #include "llvm/ADT/SmallVector.h"
42 #include "llvm/ADT/iterator_range.h"
43 #include "llvm/Support/Casting.h"
44 #include "llvm/Support/ErrorHandling.h"
45 #include "llvm/Support/Format.h"
46 #include "llvm/Support/raw_ostream.h"
47 #include <algorithm>
48 #include <cassert>
49 #include <cstddef>
50 #include <cstdint>
51 
52 using namespace clang;
53 
54 //===----------------------------------------------------------------------===//
55 // Decl Allocation/Deallocation Method Implementations
56 //===----------------------------------------------------------------------===//
57 
58 void AccessSpecDecl::anchor() {}
59 
60 AccessSpecDecl *AccessSpecDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
61   return new (C, ID) AccessSpecDecl(EmptyShell());
62 }
63 
64 void LazyASTUnresolvedSet::getFromExternalSource(ASTContext &C) const {
65   ExternalASTSource *Source = C.getExternalSource();
66   assert(Impl.Decls.isLazy() && "getFromExternalSource for non-lazy set");
67   assert(Source && "getFromExternalSource with no external source");
68 
69   for (ASTUnresolvedSet::iterator I = Impl.begin(); I != Impl.end(); ++I)
70     I.setDecl(cast<NamedDecl>(Source->GetExternalDecl(
71         reinterpret_cast<uintptr_t>(I.getDecl()) >> 2)));
72   Impl.Decls.setLazy(false);
73 }
74 
75 CXXRecordDecl::DefinitionData::DefinitionData(CXXRecordDecl *D)
76     : UserDeclaredConstructor(false), UserDeclaredSpecialMembers(0),
77       Aggregate(true), PlainOldData(true), Empty(true), Polymorphic(false),
78       Abstract(false), IsStandardLayout(true), IsCXX11StandardLayout(true),
79       HasBasesWithFields(false), HasBasesWithNonStaticDataMembers(false),
80       HasPrivateFields(false), HasProtectedFields(false),
81       HasPublicFields(false), HasMutableFields(false), HasVariantMembers(false),
82       HasOnlyCMembers(true), HasInitMethod(false), HasInClassInitializer(false),
83       HasUninitializedReferenceMember(false), HasUninitializedFields(false),
84       HasInheritedConstructor(false), HasInheritedDefaultConstructor(false),
85       HasInheritedAssignment(false),
86       NeedOverloadResolutionForCopyConstructor(false),
87       NeedOverloadResolutionForMoveConstructor(false),
88       NeedOverloadResolutionForCopyAssignment(false),
89       NeedOverloadResolutionForMoveAssignment(false),
90       NeedOverloadResolutionForDestructor(false),
91       DefaultedCopyConstructorIsDeleted(false),
92       DefaultedMoveConstructorIsDeleted(false),
93       DefaultedCopyAssignmentIsDeleted(false),
94       DefaultedMoveAssignmentIsDeleted(false),
95       DefaultedDestructorIsDeleted(false), HasTrivialSpecialMembers(SMF_All),
96       HasTrivialSpecialMembersForCall(SMF_All),
97       DeclaredNonTrivialSpecialMembers(0),
98       DeclaredNonTrivialSpecialMembersForCall(0), HasIrrelevantDestructor(true),
99       HasConstexprNonCopyMoveConstructor(false),
100       HasDefaultedDefaultConstructor(false),
101       DefaultedDefaultConstructorIsConstexpr(true),
102       HasConstexprDefaultConstructor(false),
103       DefaultedDestructorIsConstexpr(true),
104       HasNonLiteralTypeFieldsOrBases(false), StructuralIfLiteral(true),
105       UserProvidedDefaultConstructor(false), DeclaredSpecialMembers(0),
106       ImplicitCopyConstructorCanHaveConstParamForVBase(true),
107       ImplicitCopyConstructorCanHaveConstParamForNonVBase(true),
108       ImplicitCopyAssignmentHasConstParam(true),
109       HasDeclaredCopyConstructorWithConstParam(false),
110       HasDeclaredCopyAssignmentWithConstParam(false),
111       IsAnyDestructorNoReturn(false), IsLambda(false),
112       IsParsingBaseSpecifiers(false), ComputedVisibleConversions(false),
113       HasODRHash(false), Definition(D) {}
114 
115 CXXBaseSpecifier *CXXRecordDecl::DefinitionData::getBasesSlowCase() const {
116   return Bases.get(Definition->getASTContext().getExternalSource());
117 }
118 
119 CXXBaseSpecifier *CXXRecordDecl::DefinitionData::getVBasesSlowCase() const {
120   return VBases.get(Definition->getASTContext().getExternalSource());
121 }
122 
123 CXXRecordDecl::CXXRecordDecl(Kind K, TagKind TK, const ASTContext &C,
124                              DeclContext *DC, SourceLocation StartLoc,
125                              SourceLocation IdLoc, IdentifierInfo *Id,
126                              CXXRecordDecl *PrevDecl)
127     : RecordDecl(K, TK, C, DC, StartLoc, IdLoc, Id, PrevDecl),
128       DefinitionData(PrevDecl ? PrevDecl->DefinitionData
129                               : nullptr) {}
130 
131 CXXRecordDecl *CXXRecordDecl::Create(const ASTContext &C, TagKind TK,
132                                      DeclContext *DC, SourceLocation StartLoc,
133                                      SourceLocation IdLoc, IdentifierInfo *Id,
134                                      CXXRecordDecl *PrevDecl,
135                                      bool DelayTypeCreation) {
136   auto *R = new (C, DC) CXXRecordDecl(CXXRecord, TK, C, DC, StartLoc, IdLoc, Id,
137                                       PrevDecl);
138   R->setMayHaveOutOfDateDef(C.getLangOpts().Modules);
139 
140   // FIXME: DelayTypeCreation seems like such a hack
141   if (!DelayTypeCreation)
142     C.getTypeDeclType(R, PrevDecl);
143   return R;
144 }
145 
146 CXXRecordDecl *
147 CXXRecordDecl::CreateLambda(const ASTContext &C, DeclContext *DC,
148                             TypeSourceInfo *Info, SourceLocation Loc,
149                             bool Dependent, bool IsGeneric,
150                             LambdaCaptureDefault CaptureDefault) {
151   auto *R = new (C, DC) CXXRecordDecl(CXXRecord, TTK_Class, C, DC, Loc, Loc,
152                                       nullptr, nullptr);
153   R->setBeingDefined(true);
154   R->DefinitionData =
155       new (C) struct LambdaDefinitionData(R, Info, Dependent, IsGeneric,
156                                           CaptureDefault);
157   R->setMayHaveOutOfDateDef(false);
158   R->setImplicit(true);
159   C.getTypeDeclType(R, /*PrevDecl=*/nullptr);
160   return R;
161 }
162 
163 CXXRecordDecl *
164 CXXRecordDecl::CreateDeserialized(const ASTContext &C, unsigned ID) {
165   auto *R = new (C, ID) CXXRecordDecl(
166       CXXRecord, TTK_Struct, C, nullptr, SourceLocation(), SourceLocation(),
167       nullptr, nullptr);
168   R->setMayHaveOutOfDateDef(false);
169   return R;
170 }
171 
172 /// Determine whether a class has a repeated base class. This is intended for
173 /// use when determining if a class is standard-layout, so makes no attempt to
174 /// handle virtual bases.
175 static bool hasRepeatedBaseClass(const CXXRecordDecl *StartRD) {
176   llvm::SmallPtrSet<const CXXRecordDecl*, 8> SeenBaseTypes;
177   SmallVector<const CXXRecordDecl*, 8> WorkList = {StartRD};
178   while (!WorkList.empty()) {
179     const CXXRecordDecl *RD = WorkList.pop_back_val();
180     if (RD->getTypeForDecl()->isDependentType())
181       continue;
182     for (const CXXBaseSpecifier &BaseSpec : RD->bases()) {
183       if (const CXXRecordDecl *B = BaseSpec.getType()->getAsCXXRecordDecl()) {
184         if (!SeenBaseTypes.insert(B).second)
185           return true;
186         WorkList.push_back(B);
187       }
188     }
189   }
190   return false;
191 }
192 
193 void
194 CXXRecordDecl::setBases(CXXBaseSpecifier const * const *Bases,
195                         unsigned NumBases) {
196   ASTContext &C = getASTContext();
197 
198   if (!data().Bases.isOffset() && data().NumBases > 0)
199     C.Deallocate(data().getBases());
200 
201   if (NumBases) {
202     if (!C.getLangOpts().CPlusPlus17) {
203       // C++ [dcl.init.aggr]p1:
204       //   An aggregate is [...] a class with [...] no base classes [...].
205       data().Aggregate = false;
206     }
207 
208     // C++ [class]p4:
209     //   A POD-struct is an aggregate class...
210     data().PlainOldData = false;
211   }
212 
213   // The set of seen virtual base types.
214   llvm::SmallPtrSet<CanQualType, 8> SeenVBaseTypes;
215 
216   // The virtual bases of this class.
217   SmallVector<const CXXBaseSpecifier *, 8> VBases;
218 
219   data().Bases = new(C) CXXBaseSpecifier [NumBases];
220   data().NumBases = NumBases;
221   for (unsigned i = 0; i < NumBases; ++i) {
222     data().getBases()[i] = *Bases[i];
223     // Keep track of inherited vbases for this base class.
224     const CXXBaseSpecifier *Base = Bases[i];
225     QualType BaseType = Base->getType();
226     // Skip dependent types; we can't do any checking on them now.
227     if (BaseType->isDependentType())
228       continue;
229     auto *BaseClassDecl =
230         cast<CXXRecordDecl>(BaseType->castAs<RecordType>()->getDecl());
231 
232     // C++2a [class]p7:
233     //   A standard-layout class is a class that:
234     //    [...]
235     //    -- has all non-static data members and bit-fields in the class and
236     //       its base classes first declared in the same class
237     if (BaseClassDecl->data().HasBasesWithFields ||
238         !BaseClassDecl->field_empty()) {
239       if (data().HasBasesWithFields)
240         // Two bases have members or bit-fields: not standard-layout.
241         data().IsStandardLayout = false;
242       data().HasBasesWithFields = true;
243     }
244 
245     // C++11 [class]p7:
246     //   A standard-layout class is a class that:
247     //     -- [...] has [...] at most one base class with non-static data
248     //        members
249     if (BaseClassDecl->data().HasBasesWithNonStaticDataMembers ||
250         BaseClassDecl->hasDirectFields()) {
251       if (data().HasBasesWithNonStaticDataMembers)
252         data().IsCXX11StandardLayout = false;
253       data().HasBasesWithNonStaticDataMembers = true;
254     }
255 
256     if (!BaseClassDecl->isEmpty()) {
257       // C++14 [meta.unary.prop]p4:
258       //   T is a class type [...] with [...] no base class B for which
259       //   is_empty<B>::value is false.
260       data().Empty = false;
261     }
262 
263     // C++1z [dcl.init.agg]p1:
264     //   An aggregate is a class with [...] no private or protected base classes
265     if (Base->getAccessSpecifier() != AS_public) {
266       data().Aggregate = false;
267 
268       // C++20 [temp.param]p7:
269       //   A structural type is [...] a literal class type with [...] all base
270       //   classes [...] public
271       data().StructuralIfLiteral = false;
272     }
273 
274     // C++ [class.virtual]p1:
275     //   A class that declares or inherits a virtual function is called a
276     //   polymorphic class.
277     if (BaseClassDecl->isPolymorphic()) {
278       data().Polymorphic = true;
279 
280       //   An aggregate is a class with [...] no virtual functions.
281       data().Aggregate = false;
282     }
283 
284     // C++0x [class]p7:
285     //   A standard-layout class is a class that: [...]
286     //    -- has no non-standard-layout base classes
287     if (!BaseClassDecl->isStandardLayout())
288       data().IsStandardLayout = false;
289     if (!BaseClassDecl->isCXX11StandardLayout())
290       data().IsCXX11StandardLayout = false;
291 
292     // Record if this base is the first non-literal field or base.
293     if (!hasNonLiteralTypeFieldsOrBases() && !BaseType->isLiteralType(C))
294       data().HasNonLiteralTypeFieldsOrBases = true;
295 
296     // Now go through all virtual bases of this base and add them.
297     for (const auto &VBase : BaseClassDecl->vbases()) {
298       // Add this base if it's not already in the list.
299       if (SeenVBaseTypes.insert(C.getCanonicalType(VBase.getType())).second) {
300         VBases.push_back(&VBase);
301 
302         // C++11 [class.copy]p8:
303         //   The implicitly-declared copy constructor for a class X will have
304         //   the form 'X::X(const X&)' if each [...] virtual base class B of X
305         //   has a copy constructor whose first parameter is of type
306         //   'const B&' or 'const volatile B&' [...]
307         if (CXXRecordDecl *VBaseDecl = VBase.getType()->getAsCXXRecordDecl())
308           if (!VBaseDecl->hasCopyConstructorWithConstParam())
309             data().ImplicitCopyConstructorCanHaveConstParamForVBase = false;
310 
311         // C++1z [dcl.init.agg]p1:
312         //   An aggregate is a class with [...] no virtual base classes
313         data().Aggregate = false;
314       }
315     }
316 
317     if (Base->isVirtual()) {
318       // Add this base if it's not already in the list.
319       if (SeenVBaseTypes.insert(C.getCanonicalType(BaseType)).second)
320         VBases.push_back(Base);
321 
322       // C++14 [meta.unary.prop] is_empty:
323       //   T is a class type, but not a union type, with ... no virtual base
324       //   classes
325       data().Empty = false;
326 
327       // C++1z [dcl.init.agg]p1:
328       //   An aggregate is a class with [...] no virtual base classes
329       data().Aggregate = false;
330 
331       // C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25:
332       //   A [default constructor, copy/move constructor, or copy/move assignment
333       //   operator for a class X] is trivial [...] if:
334       //    -- class X has [...] no virtual base classes
335       data().HasTrivialSpecialMembers &= SMF_Destructor;
336       data().HasTrivialSpecialMembersForCall &= SMF_Destructor;
337 
338       // C++0x [class]p7:
339       //   A standard-layout class is a class that: [...]
340       //    -- has [...] no virtual base classes
341       data().IsStandardLayout = false;
342       data().IsCXX11StandardLayout = false;
343 
344       // C++20 [dcl.constexpr]p3:
345       //   In the definition of a constexpr function [...]
346       //    -- if the function is a constructor or destructor,
347       //       its class shall not have any virtual base classes
348       data().DefaultedDefaultConstructorIsConstexpr = false;
349       data().DefaultedDestructorIsConstexpr = false;
350 
351       // C++1z [class.copy]p8:
352       //   The implicitly-declared copy constructor for a class X will have
353       //   the form 'X::X(const X&)' if each potentially constructed subobject
354       //   has a copy constructor whose first parameter is of type
355       //   'const B&' or 'const volatile B&' [...]
356       if (!BaseClassDecl->hasCopyConstructorWithConstParam())
357         data().ImplicitCopyConstructorCanHaveConstParamForVBase = false;
358     } else {
359       // C++ [class.ctor]p5:
360       //   A default constructor is trivial [...] if:
361       //    -- all the direct base classes of its class have trivial default
362       //       constructors.
363       if (!BaseClassDecl->hasTrivialDefaultConstructor())
364         data().HasTrivialSpecialMembers &= ~SMF_DefaultConstructor;
365 
366       // C++0x [class.copy]p13:
367       //   A copy/move constructor for class X is trivial if [...]
368       //    [...]
369       //    -- the constructor selected to copy/move each direct base class
370       //       subobject is trivial, and
371       if (!BaseClassDecl->hasTrivialCopyConstructor())
372         data().HasTrivialSpecialMembers &= ~SMF_CopyConstructor;
373 
374       if (!BaseClassDecl->hasTrivialCopyConstructorForCall())
375         data().HasTrivialSpecialMembersForCall &= ~SMF_CopyConstructor;
376 
377       // If the base class doesn't have a simple move constructor, we'll eagerly
378       // declare it and perform overload resolution to determine which function
379       // it actually calls. If it does have a simple move constructor, this
380       // check is correct.
381       if (!BaseClassDecl->hasTrivialMoveConstructor())
382         data().HasTrivialSpecialMembers &= ~SMF_MoveConstructor;
383 
384       if (!BaseClassDecl->hasTrivialMoveConstructorForCall())
385         data().HasTrivialSpecialMembersForCall &= ~SMF_MoveConstructor;
386 
387       // C++0x [class.copy]p27:
388       //   A copy/move assignment operator for class X is trivial if [...]
389       //    [...]
390       //    -- the assignment operator selected to copy/move each direct base
391       //       class subobject is trivial, and
392       if (!BaseClassDecl->hasTrivialCopyAssignment())
393         data().HasTrivialSpecialMembers &= ~SMF_CopyAssignment;
394       // If the base class doesn't have a simple move assignment, we'll eagerly
395       // declare it and perform overload resolution to determine which function
396       // it actually calls. If it does have a simple move assignment, this
397       // check is correct.
398       if (!BaseClassDecl->hasTrivialMoveAssignment())
399         data().HasTrivialSpecialMembers &= ~SMF_MoveAssignment;
400 
401       // C++11 [class.ctor]p6:
402       //   If that user-written default constructor would satisfy the
403       //   requirements of a constexpr constructor, the implicitly-defined
404       //   default constructor is constexpr.
405       if (!BaseClassDecl->hasConstexprDefaultConstructor())
406         data().DefaultedDefaultConstructorIsConstexpr = false;
407 
408       // C++1z [class.copy]p8:
409       //   The implicitly-declared copy constructor for a class X will have
410       //   the form 'X::X(const X&)' if each potentially constructed subobject
411       //   has a copy constructor whose first parameter is of type
412       //   'const B&' or 'const volatile B&' [...]
413       if (!BaseClassDecl->hasCopyConstructorWithConstParam())
414         data().ImplicitCopyConstructorCanHaveConstParamForNonVBase = false;
415     }
416 
417     // C++ [class.ctor]p3:
418     //   A destructor is trivial if all the direct base classes of its class
419     //   have trivial destructors.
420     if (!BaseClassDecl->hasTrivialDestructor())
421       data().HasTrivialSpecialMembers &= ~SMF_Destructor;
422 
423     if (!BaseClassDecl->hasTrivialDestructorForCall())
424       data().HasTrivialSpecialMembersForCall &= ~SMF_Destructor;
425 
426     if (!BaseClassDecl->hasIrrelevantDestructor())
427       data().HasIrrelevantDestructor = false;
428 
429     if (BaseClassDecl->isAnyDestructorNoReturn())
430       data().IsAnyDestructorNoReturn = true;
431 
432     // C++11 [class.copy]p18:
433     //   The implicitly-declared copy assignment operator for a class X will
434     //   have the form 'X& X::operator=(const X&)' if each direct base class B
435     //   of X has a copy assignment operator whose parameter is of type 'const
436     //   B&', 'const volatile B&', or 'B' [...]
437     if (!BaseClassDecl->hasCopyAssignmentWithConstParam())
438       data().ImplicitCopyAssignmentHasConstParam = false;
439 
440     // A class has an Objective-C object member if... or any of its bases
441     // has an Objective-C object member.
442     if (BaseClassDecl->hasObjectMember())
443       setHasObjectMember(true);
444 
445     if (BaseClassDecl->hasVolatileMember())
446       setHasVolatileMember(true);
447 
448     if (BaseClassDecl->getArgPassingRestrictions() ==
449         RecordDecl::APK_CanNeverPassInRegs)
450       setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
451 
452     // Keep track of the presence of mutable fields.
453     if (BaseClassDecl->hasMutableFields())
454       data().HasMutableFields = true;
455 
456     if (BaseClassDecl->hasUninitializedReferenceMember())
457       data().HasUninitializedReferenceMember = true;
458 
459     if (!BaseClassDecl->allowConstDefaultInit())
460       data().HasUninitializedFields = true;
461 
462     addedClassSubobject(BaseClassDecl);
463   }
464 
465   // C++2a [class]p7:
466   //   A class S is a standard-layout class if it:
467   //     -- has at most one base class subobject of any given type
468   //
469   // Note that we only need to check this for classes with more than one base
470   // class. If there's only one base class, and it's standard layout, then
471   // we know there are no repeated base classes.
472   if (data().IsStandardLayout && NumBases > 1 && hasRepeatedBaseClass(this))
473     data().IsStandardLayout = false;
474 
475   if (VBases.empty()) {
476     data().IsParsingBaseSpecifiers = false;
477     return;
478   }
479 
480   // Create base specifier for any direct or indirect virtual bases.
481   data().VBases = new (C) CXXBaseSpecifier[VBases.size()];
482   data().NumVBases = VBases.size();
483   for (int I = 0, E = VBases.size(); I != E; ++I) {
484     QualType Type = VBases[I]->getType();
485     if (!Type->isDependentType())
486       addedClassSubobject(Type->getAsCXXRecordDecl());
487     data().getVBases()[I] = *VBases[I];
488   }
489 
490   data().IsParsingBaseSpecifiers = false;
491 }
492 
493 unsigned CXXRecordDecl::getODRHash() const {
494   assert(hasDefinition() && "ODRHash only for records with definitions");
495 
496   // Previously calculated hash is stored in DefinitionData.
497   if (DefinitionData->HasODRHash)
498     return DefinitionData->ODRHash;
499 
500   // Only calculate hash on first call of getODRHash per record.
501   ODRHash Hash;
502   Hash.AddCXXRecordDecl(getDefinition());
503   DefinitionData->HasODRHash = true;
504   DefinitionData->ODRHash = Hash.CalculateHash();
505 
506   return DefinitionData->ODRHash;
507 }
508 
509 void CXXRecordDecl::addedClassSubobject(CXXRecordDecl *Subobj) {
510   // C++11 [class.copy]p11:
511   //   A defaulted copy/move constructor for a class X is defined as
512   //   deleted if X has:
513   //    -- a direct or virtual base class B that cannot be copied/moved [...]
514   //    -- a non-static data member of class type M (or array thereof)
515   //       that cannot be copied or moved [...]
516   if (!Subobj->hasSimpleCopyConstructor())
517     data().NeedOverloadResolutionForCopyConstructor = true;
518   if (!Subobj->hasSimpleMoveConstructor())
519     data().NeedOverloadResolutionForMoveConstructor = true;
520 
521   // C++11 [class.copy]p23:
522   //   A defaulted copy/move assignment operator for a class X is defined as
523   //   deleted if X has:
524   //    -- a direct or virtual base class B that cannot be copied/moved [...]
525   //    -- a non-static data member of class type M (or array thereof)
526   //        that cannot be copied or moved [...]
527   if (!Subobj->hasSimpleCopyAssignment())
528     data().NeedOverloadResolutionForCopyAssignment = true;
529   if (!Subobj->hasSimpleMoveAssignment())
530     data().NeedOverloadResolutionForMoveAssignment = true;
531 
532   // C++11 [class.ctor]p5, C++11 [class.copy]p11, C++11 [class.dtor]p5:
533   //   A defaulted [ctor or dtor] for a class X is defined as
534   //   deleted if X has:
535   //    -- any direct or virtual base class [...] has a type with a destructor
536   //       that is deleted or inaccessible from the defaulted [ctor or dtor].
537   //    -- any non-static data member has a type with a destructor
538   //       that is deleted or inaccessible from the defaulted [ctor or dtor].
539   if (!Subobj->hasSimpleDestructor()) {
540     data().NeedOverloadResolutionForCopyConstructor = true;
541     data().NeedOverloadResolutionForMoveConstructor = true;
542     data().NeedOverloadResolutionForDestructor = true;
543   }
544 
545   // C++2a [dcl.constexpr]p4:
546   //   The definition of a constexpr destructor [shall] satisfy the
547   //   following requirement:
548   //   -- for every subobject of class type or (possibly multi-dimensional)
549   //      array thereof, that class type shall have a constexpr destructor
550   if (!Subobj->hasConstexprDestructor())
551     data().DefaultedDestructorIsConstexpr = false;
552 
553   // C++20 [temp.param]p7:
554   //   A structural type is [...] a literal class type [for which] the types
555   //   of all base classes and non-static data members are structural types or
556   //   (possibly multi-dimensional) array thereof
557   if (!Subobj->data().StructuralIfLiteral)
558     data().StructuralIfLiteral = false;
559 }
560 
561 bool CXXRecordDecl::hasConstexprDestructor() const {
562   auto *Dtor = getDestructor();
563   return Dtor ? Dtor->isConstexpr() : defaultedDestructorIsConstexpr();
564 }
565 
566 bool CXXRecordDecl::hasAnyDependentBases() const {
567   if (!isDependentContext())
568     return false;
569 
570   return !forallBases([](const CXXRecordDecl *) { return true; });
571 }
572 
573 bool CXXRecordDecl::isTriviallyCopyable() const {
574   // C++0x [class]p5:
575   //   A trivially copyable class is a class that:
576   //   -- has no non-trivial copy constructors,
577   if (hasNonTrivialCopyConstructor()) return false;
578   //   -- has no non-trivial move constructors,
579   if (hasNonTrivialMoveConstructor()) return false;
580   //   -- has no non-trivial copy assignment operators,
581   if (hasNonTrivialCopyAssignment()) return false;
582   //   -- has no non-trivial move assignment operators, and
583   if (hasNonTrivialMoveAssignment()) return false;
584   //   -- has a trivial destructor.
585   if (!hasTrivialDestructor()) return false;
586 
587   return true;
588 }
589 
590 void CXXRecordDecl::markedVirtualFunctionPure() {
591   // C++ [class.abstract]p2:
592   //   A class is abstract if it has at least one pure virtual function.
593   data().Abstract = true;
594 }
595 
596 bool CXXRecordDecl::hasSubobjectAtOffsetZeroOfEmptyBaseType(
597     ASTContext &Ctx, const CXXRecordDecl *XFirst) {
598   if (!getNumBases())
599     return false;
600 
601   llvm::SmallPtrSet<const CXXRecordDecl*, 8> Bases;
602   llvm::SmallPtrSet<const CXXRecordDecl*, 8> M;
603   SmallVector<const CXXRecordDecl*, 8> WorkList;
604 
605   // Visit a type that we have determined is an element of M(S).
606   auto Visit = [&](const CXXRecordDecl *RD) -> bool {
607     RD = RD->getCanonicalDecl();
608 
609     // C++2a [class]p8:
610     //   A class S is a standard-layout class if it [...] has no element of the
611     //   set M(S) of types as a base class.
612     //
613     // If we find a subobject of an empty type, it might also be a base class,
614     // so we'll need to walk the base classes to check.
615     if (!RD->data().HasBasesWithFields) {
616       // Walk the bases the first time, stopping if we find the type. Build a
617       // set of them so we don't need to walk them again.
618       if (Bases.empty()) {
619         bool RDIsBase = !forallBases([&](const CXXRecordDecl *Base) -> bool {
620           Base = Base->getCanonicalDecl();
621           if (RD == Base)
622             return false;
623           Bases.insert(Base);
624           return true;
625         });
626         if (RDIsBase)
627           return true;
628       } else {
629         if (Bases.count(RD))
630           return true;
631       }
632     }
633 
634     if (M.insert(RD).second)
635       WorkList.push_back(RD);
636     return false;
637   };
638 
639   if (Visit(XFirst))
640     return true;
641 
642   while (!WorkList.empty()) {
643     const CXXRecordDecl *X = WorkList.pop_back_val();
644 
645     // FIXME: We don't check the bases of X. That matches the standard, but
646     // that sure looks like a wording bug.
647 
648     //   -- If X is a non-union class type with a non-static data member
649     //      [recurse to each field] that is either of zero size or is the
650     //      first non-static data member of X
651     //   -- If X is a union type, [recurse to union members]
652     bool IsFirstField = true;
653     for (auto *FD : X->fields()) {
654       // FIXME: Should we really care about the type of the first non-static
655       // data member of a non-union if there are preceding unnamed bit-fields?
656       if (FD->isUnnamedBitfield())
657         continue;
658 
659       if (!IsFirstField && !FD->isZeroSize(Ctx))
660         continue;
661 
662       //   -- If X is n array type, [visit the element type]
663       QualType T = Ctx.getBaseElementType(FD->getType());
664       if (auto *RD = T->getAsCXXRecordDecl())
665         if (Visit(RD))
666           return true;
667 
668       if (!X->isUnion())
669         IsFirstField = false;
670     }
671   }
672 
673   return false;
674 }
675 
676 bool CXXRecordDecl::lambdaIsDefaultConstructibleAndAssignable() const {
677   assert(isLambda() && "not a lambda");
678 
679   // C++2a [expr.prim.lambda.capture]p11:
680   //   The closure type associated with a lambda-expression has no default
681   //   constructor if the lambda-expression has a lambda-capture and a
682   //   defaulted default constructor otherwise. It has a deleted copy
683   //   assignment operator if the lambda-expression has a lambda-capture and
684   //   defaulted copy and move assignment operators otherwise.
685   //
686   // C++17 [expr.prim.lambda]p21:
687   //   The closure type associated with a lambda-expression has no default
688   //   constructor and a deleted copy assignment operator.
689   if (getLambdaCaptureDefault() != LCD_None || capture_size() != 0)
690     return false;
691   return getASTContext().getLangOpts().CPlusPlus20;
692 }
693 
694 void CXXRecordDecl::addedMember(Decl *D) {
695   if (!D->isImplicit() &&
696       !isa<FieldDecl>(D) &&
697       !isa<IndirectFieldDecl>(D) &&
698       (!isa<TagDecl>(D) || cast<TagDecl>(D)->getTagKind() == TTK_Class ||
699         cast<TagDecl>(D)->getTagKind() == TTK_Interface))
700     data().HasOnlyCMembers = false;
701 
702   // Ignore friends and invalid declarations.
703   if (D->getFriendObjectKind() || D->isInvalidDecl())
704     return;
705 
706   auto *FunTmpl = dyn_cast<FunctionTemplateDecl>(D);
707   if (FunTmpl)
708     D = FunTmpl->getTemplatedDecl();
709 
710   // FIXME: Pass NamedDecl* to addedMember?
711   Decl *DUnderlying = D;
712   if (auto *ND = dyn_cast<NamedDecl>(DUnderlying)) {
713     DUnderlying = ND->getUnderlyingDecl();
714     if (auto *UnderlyingFunTmpl = dyn_cast<FunctionTemplateDecl>(DUnderlying))
715       DUnderlying = UnderlyingFunTmpl->getTemplatedDecl();
716   }
717 
718   if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
719     if (Method->isVirtual()) {
720       // C++ [dcl.init.aggr]p1:
721       //   An aggregate is an array or a class with [...] no virtual functions.
722       data().Aggregate = false;
723 
724       // C++ [class]p4:
725       //   A POD-struct is an aggregate class...
726       data().PlainOldData = false;
727 
728       // C++14 [meta.unary.prop]p4:
729       //   T is a class type [...] with [...] no virtual member functions...
730       data().Empty = false;
731 
732       // C++ [class.virtual]p1:
733       //   A class that declares or inherits a virtual function is called a
734       //   polymorphic class.
735       data().Polymorphic = true;
736 
737       // C++11 [class.ctor]p5, C++11 [class.copy]p12, C++11 [class.copy]p25:
738       //   A [default constructor, copy/move constructor, or copy/move
739       //   assignment operator for a class X] is trivial [...] if:
740       //    -- class X has no virtual functions [...]
741       data().HasTrivialSpecialMembers &= SMF_Destructor;
742       data().HasTrivialSpecialMembersForCall &= SMF_Destructor;
743 
744       // C++0x [class]p7:
745       //   A standard-layout class is a class that: [...]
746       //    -- has no virtual functions
747       data().IsStandardLayout = false;
748       data().IsCXX11StandardLayout = false;
749     }
750   }
751 
752   // Notify the listener if an implicit member was added after the definition
753   // was completed.
754   if (!isBeingDefined() && D->isImplicit())
755     if (ASTMutationListener *L = getASTMutationListener())
756       L->AddedCXXImplicitMember(data().Definition, D);
757 
758   // The kind of special member this declaration is, if any.
759   unsigned SMKind = 0;
760 
761   // Handle constructors.
762   if (const auto *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
763     if (Constructor->isInheritingConstructor()) {
764       // Ignore constructor shadow declarations. They are lazily created and
765       // so shouldn't affect any properties of the class.
766     } else {
767       if (!Constructor->isImplicit()) {
768         // Note that we have a user-declared constructor.
769         data().UserDeclaredConstructor = true;
770 
771         // C++ [class]p4:
772         //   A POD-struct is an aggregate class [...]
773         // Since the POD bit is meant to be C++03 POD-ness, clear it even if
774         // the type is technically an aggregate in C++0x since it wouldn't be
775         // in 03.
776         data().PlainOldData = false;
777       }
778 
779       if (Constructor->isDefaultConstructor()) {
780         SMKind |= SMF_DefaultConstructor;
781 
782         if (Constructor->isUserProvided())
783           data().UserProvidedDefaultConstructor = true;
784         if (Constructor->isConstexpr())
785           data().HasConstexprDefaultConstructor = true;
786         if (Constructor->isDefaulted())
787           data().HasDefaultedDefaultConstructor = true;
788       }
789 
790       if (!FunTmpl) {
791         unsigned Quals;
792         if (Constructor->isCopyConstructor(Quals)) {
793           SMKind |= SMF_CopyConstructor;
794 
795           if (Quals & Qualifiers::Const)
796             data().HasDeclaredCopyConstructorWithConstParam = true;
797         } else if (Constructor->isMoveConstructor())
798           SMKind |= SMF_MoveConstructor;
799       }
800 
801       // C++11 [dcl.init.aggr]p1: DR1518
802       //   An aggregate is an array or a class with no user-provided [or]
803       //   explicit [...] constructors
804       // C++20 [dcl.init.aggr]p1:
805       //   An aggregate is an array or a class with no user-declared [...]
806       //   constructors
807       if (getASTContext().getLangOpts().CPlusPlus20
808               ? !Constructor->isImplicit()
809               : (Constructor->isUserProvided() || Constructor->isExplicit()))
810         data().Aggregate = false;
811     }
812   }
813 
814   // Handle constructors, including those inherited from base classes.
815   if (const auto *Constructor = dyn_cast<CXXConstructorDecl>(DUnderlying)) {
816     // Record if we see any constexpr constructors which are neither copy
817     // nor move constructors.
818     // C++1z [basic.types]p10:
819     //   [...] has at least one constexpr constructor or constructor template
820     //   (possibly inherited from a base class) that is not a copy or move
821     //   constructor [...]
822     if (Constructor->isConstexpr() && !Constructor->isCopyOrMoveConstructor())
823       data().HasConstexprNonCopyMoveConstructor = true;
824     if (!isa<CXXConstructorDecl>(D) && Constructor->isDefaultConstructor())
825       data().HasInheritedDefaultConstructor = true;
826   }
827 
828   // Handle destructors.
829   if (const auto *DD = dyn_cast<CXXDestructorDecl>(D)) {
830     SMKind |= SMF_Destructor;
831 
832     if (DD->isUserProvided())
833       data().HasIrrelevantDestructor = false;
834     // If the destructor is explicitly defaulted and not trivial or not public
835     // or if the destructor is deleted, we clear HasIrrelevantDestructor in
836     // finishedDefaultedOrDeletedMember.
837 
838     // C++11 [class.dtor]p5:
839     //   A destructor is trivial if [...] the destructor is not virtual.
840     if (DD->isVirtual()) {
841       data().HasTrivialSpecialMembers &= ~SMF_Destructor;
842       data().HasTrivialSpecialMembersForCall &= ~SMF_Destructor;
843     }
844 
845     if (DD->isNoReturn())
846       data().IsAnyDestructorNoReturn = true;
847   }
848 
849   // Handle member functions.
850   if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
851     if (Method->isCopyAssignmentOperator()) {
852       SMKind |= SMF_CopyAssignment;
853 
854       const auto *ParamTy =
855           Method->getParamDecl(0)->getType()->getAs<ReferenceType>();
856       if (!ParamTy || ParamTy->getPointeeType().isConstQualified())
857         data().HasDeclaredCopyAssignmentWithConstParam = true;
858     }
859 
860     if (Method->isMoveAssignmentOperator())
861       SMKind |= SMF_MoveAssignment;
862 
863     // Keep the list of conversion functions up-to-date.
864     if (auto *Conversion = dyn_cast<CXXConversionDecl>(D)) {
865       // FIXME: We use the 'unsafe' accessor for the access specifier here,
866       // because Sema may not have set it yet. That's really just a misdesign
867       // in Sema. However, LLDB *will* have set the access specifier correctly,
868       // and adds declarations after the class is technically completed,
869       // so completeDefinition()'s overriding of the access specifiers doesn't
870       // work.
871       AccessSpecifier AS = Conversion->getAccessUnsafe();
872 
873       if (Conversion->getPrimaryTemplate()) {
874         // We don't record specializations.
875       } else {
876         ASTContext &Ctx = getASTContext();
877         ASTUnresolvedSet &Conversions = data().Conversions.get(Ctx);
878         NamedDecl *Primary =
879             FunTmpl ? cast<NamedDecl>(FunTmpl) : cast<NamedDecl>(Conversion);
880         if (Primary->getPreviousDecl())
881           Conversions.replace(cast<NamedDecl>(Primary->getPreviousDecl()),
882                               Primary, AS);
883         else
884           Conversions.addDecl(Ctx, Primary, AS);
885       }
886     }
887 
888     if (SMKind) {
889       // If this is the first declaration of a special member, we no longer have
890       // an implicit trivial special member.
891       data().HasTrivialSpecialMembers &=
892           data().DeclaredSpecialMembers | ~SMKind;
893       data().HasTrivialSpecialMembersForCall &=
894           data().DeclaredSpecialMembers | ~SMKind;
895 
896       if (!Method->isImplicit() && !Method->isUserProvided()) {
897         // This method is user-declared but not user-provided. We can't work out
898         // whether it's trivial yet (not until we get to the end of the class).
899         // We'll handle this method in finishedDefaultedOrDeletedMember.
900       } else if (Method->isTrivial()) {
901         data().HasTrivialSpecialMembers |= SMKind;
902         data().HasTrivialSpecialMembersForCall |= SMKind;
903       } else if (Method->isTrivialForCall()) {
904         data().HasTrivialSpecialMembersForCall |= SMKind;
905         data().DeclaredNonTrivialSpecialMembers |= SMKind;
906       } else {
907         data().DeclaredNonTrivialSpecialMembers |= SMKind;
908         // If this is a user-provided function, do not set
909         // DeclaredNonTrivialSpecialMembersForCall here since we don't know
910         // yet whether the method would be considered non-trivial for the
911         // purpose of calls (attribute "trivial_abi" can be dropped from the
912         // class later, which can change the special method's triviality).
913         if (!Method->isUserProvided())
914           data().DeclaredNonTrivialSpecialMembersForCall |= SMKind;
915       }
916 
917       // Note when we have declared a declared special member, and suppress the
918       // implicit declaration of this special member.
919       data().DeclaredSpecialMembers |= SMKind;
920 
921       if (!Method->isImplicit()) {
922         data().UserDeclaredSpecialMembers |= SMKind;
923 
924         // C++03 [class]p4:
925         //   A POD-struct is an aggregate class that has [...] no user-defined
926         //   copy assignment operator and no user-defined destructor.
927         //
928         // Since the POD bit is meant to be C++03 POD-ness, and in C++03,
929         // aggregates could not have any constructors, clear it even for an
930         // explicitly defaulted or deleted constructor.
931         // type is technically an aggregate in C++0x since it wouldn't be in 03.
932         //
933         // Also, a user-declared move assignment operator makes a class non-POD.
934         // This is an extension in C++03.
935         data().PlainOldData = false;
936       }
937     }
938 
939     return;
940   }
941 
942   // Handle non-static data members.
943   if (const auto *Field = dyn_cast<FieldDecl>(D)) {
944     ASTContext &Context = getASTContext();
945 
946     // C++2a [class]p7:
947     //   A standard-layout class is a class that:
948     //    [...]
949     //    -- has all non-static data members and bit-fields in the class and
950     //       its base classes first declared in the same class
951     if (data().HasBasesWithFields)
952       data().IsStandardLayout = false;
953 
954     // C++ [class.bit]p2:
955     //   A declaration for a bit-field that omits the identifier declares an
956     //   unnamed bit-field. Unnamed bit-fields are not members and cannot be
957     //   initialized.
958     if (Field->isUnnamedBitfield()) {
959       // C++ [meta.unary.prop]p4: [LWG2358]
960       //   T is a class type [...] with [...] no unnamed bit-fields of non-zero
961       //   length
962       if (data().Empty && !Field->isZeroLengthBitField(Context) &&
963           Context.getLangOpts().getClangABICompat() >
964               LangOptions::ClangABI::Ver6)
965         data().Empty = false;
966       return;
967     }
968 
969     // C++11 [class]p7:
970     //   A standard-layout class is a class that:
971     //    -- either has no non-static data members in the most derived class
972     //       [...] or has no base classes with non-static data members
973     if (data().HasBasesWithNonStaticDataMembers)
974       data().IsCXX11StandardLayout = false;
975 
976     // C++ [dcl.init.aggr]p1:
977     //   An aggregate is an array or a class (clause 9) with [...] no
978     //   private or protected non-static data members (clause 11).
979     //
980     // A POD must be an aggregate.
981     if (D->getAccess() == AS_private || D->getAccess() == AS_protected) {
982       data().Aggregate = false;
983       data().PlainOldData = false;
984 
985       // C++20 [temp.param]p7:
986       //   A structural type is [...] a literal class type [for which] all
987       //   non-static data members are public
988       data().StructuralIfLiteral = false;
989     }
990 
991     // Track whether this is the first field. We use this when checking
992     // whether the class is standard-layout below.
993     bool IsFirstField = !data().HasPrivateFields &&
994                         !data().HasProtectedFields && !data().HasPublicFields;
995 
996     // C++0x [class]p7:
997     //   A standard-layout class is a class that:
998     //    [...]
999     //    -- has the same access control for all non-static data members,
1000     switch (D->getAccess()) {
1001     case AS_private:    data().HasPrivateFields = true;   break;
1002     case AS_protected:  data().HasProtectedFields = true; break;
1003     case AS_public:     data().HasPublicFields = true;    break;
1004     case AS_none:       llvm_unreachable("Invalid access specifier");
1005     };
1006     if ((data().HasPrivateFields + data().HasProtectedFields +
1007          data().HasPublicFields) > 1) {
1008       data().IsStandardLayout = false;
1009       data().IsCXX11StandardLayout = false;
1010     }
1011 
1012     // Keep track of the presence of mutable fields.
1013     if (Field->isMutable()) {
1014       data().HasMutableFields = true;
1015 
1016       // C++20 [temp.param]p7:
1017       //   A structural type is [...] a literal class type [for which] all
1018       //   non-static data members are public
1019       data().StructuralIfLiteral = false;
1020     }
1021 
1022     // C++11 [class.union]p8, DR1460:
1023     //   If X is a union, a non-static data member of X that is not an anonymous
1024     //   union is a variant member of X.
1025     if (isUnion() && !Field->isAnonymousStructOrUnion())
1026       data().HasVariantMembers = true;
1027 
1028     // C++0x [class]p9:
1029     //   A POD struct is a class that is both a trivial class and a
1030     //   standard-layout class, and has no non-static data members of type
1031     //   non-POD struct, non-POD union (or array of such types).
1032     //
1033     // Automatic Reference Counting: the presence of a member of Objective-C pointer type
1034     // that does not explicitly have no lifetime makes the class a non-POD.
1035     QualType T = Context.getBaseElementType(Field->getType());
1036     if (T->isObjCRetainableType() || T.isObjCGCStrong()) {
1037       if (T.hasNonTrivialObjCLifetime()) {
1038         // Objective-C Automatic Reference Counting:
1039         //   If a class has a non-static data member of Objective-C pointer
1040         //   type (or array thereof), it is a non-POD type and its
1041         //   default constructor (if any), copy constructor, move constructor,
1042         //   copy assignment operator, move assignment operator, and destructor are
1043         //   non-trivial.
1044         setHasObjectMember(true);
1045         struct DefinitionData &Data = data();
1046         Data.PlainOldData = false;
1047         Data.HasTrivialSpecialMembers = 0;
1048 
1049         // __strong or __weak fields do not make special functions non-trivial
1050         // for the purpose of calls.
1051         Qualifiers::ObjCLifetime LT = T.getQualifiers().getObjCLifetime();
1052         if (LT != Qualifiers::OCL_Strong && LT != Qualifiers::OCL_Weak)
1053           data().HasTrivialSpecialMembersForCall = 0;
1054 
1055         // Structs with __weak fields should never be passed directly.
1056         if (LT == Qualifiers::OCL_Weak)
1057           setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
1058 
1059         Data.HasIrrelevantDestructor = false;
1060 
1061         if (isUnion()) {
1062           data().DefaultedCopyConstructorIsDeleted = true;
1063           data().DefaultedMoveConstructorIsDeleted = true;
1064           data().DefaultedCopyAssignmentIsDeleted = true;
1065           data().DefaultedMoveAssignmentIsDeleted = true;
1066           data().DefaultedDestructorIsDeleted = true;
1067           data().NeedOverloadResolutionForCopyConstructor = true;
1068           data().NeedOverloadResolutionForMoveConstructor = true;
1069           data().NeedOverloadResolutionForCopyAssignment = true;
1070           data().NeedOverloadResolutionForMoveAssignment = true;
1071           data().NeedOverloadResolutionForDestructor = true;
1072         }
1073       } else if (!Context.getLangOpts().ObjCAutoRefCount) {
1074         setHasObjectMember(true);
1075       }
1076     } else if (!T.isCXX98PODType(Context))
1077       data().PlainOldData = false;
1078 
1079     if (T->isReferenceType()) {
1080       if (!Field->hasInClassInitializer())
1081         data().HasUninitializedReferenceMember = true;
1082 
1083       // C++0x [class]p7:
1084       //   A standard-layout class is a class that:
1085       //    -- has no non-static data members of type [...] reference,
1086       data().IsStandardLayout = false;
1087       data().IsCXX11StandardLayout = false;
1088 
1089       // C++1z [class.copy.ctor]p10:
1090       //   A defaulted copy constructor for a class X is defined as deleted if X has:
1091       //    -- a non-static data member of rvalue reference type
1092       if (T->isRValueReferenceType())
1093         data().DefaultedCopyConstructorIsDeleted = true;
1094     }
1095 
1096     if (!Field->hasInClassInitializer() && !Field->isMutable()) {
1097       if (CXXRecordDecl *FieldType = T->getAsCXXRecordDecl()) {
1098         if (FieldType->hasDefinition() && !FieldType->allowConstDefaultInit())
1099           data().HasUninitializedFields = true;
1100       } else {
1101         data().HasUninitializedFields = true;
1102       }
1103     }
1104 
1105     // Record if this field is the first non-literal or volatile field or base.
1106     if (!T->isLiteralType(Context) || T.isVolatileQualified())
1107       data().HasNonLiteralTypeFieldsOrBases = true;
1108 
1109     if (Field->hasInClassInitializer() ||
1110         (Field->isAnonymousStructOrUnion() &&
1111          Field->getType()->getAsCXXRecordDecl()->hasInClassInitializer())) {
1112       data().HasInClassInitializer = true;
1113 
1114       // C++11 [class]p5:
1115       //   A default constructor is trivial if [...] no non-static data member
1116       //   of its class has a brace-or-equal-initializer.
1117       data().HasTrivialSpecialMembers &= ~SMF_DefaultConstructor;
1118 
1119       // C++11 [dcl.init.aggr]p1:
1120       //   An aggregate is a [...] class with [...] no
1121       //   brace-or-equal-initializers for non-static data members.
1122       //
1123       // This rule was removed in C++14.
1124       if (!getASTContext().getLangOpts().CPlusPlus14)
1125         data().Aggregate = false;
1126 
1127       // C++11 [class]p10:
1128       //   A POD struct is [...] a trivial class.
1129       data().PlainOldData = false;
1130     }
1131 
1132     // C++11 [class.copy]p23:
1133     //   A defaulted copy/move assignment operator for a class X is defined
1134     //   as deleted if X has:
1135     //    -- a non-static data member of reference type
1136     if (T->isReferenceType()) {
1137       data().DefaultedCopyAssignmentIsDeleted = true;
1138       data().DefaultedMoveAssignmentIsDeleted = true;
1139     }
1140 
1141     // Bitfields of length 0 are also zero-sized, but we already bailed out for
1142     // those because they are always unnamed.
1143     bool IsZeroSize = Field->isZeroSize(Context);
1144 
1145     if (const auto *RecordTy = T->getAs<RecordType>()) {
1146       auto *FieldRec = cast<CXXRecordDecl>(RecordTy->getDecl());
1147       if (FieldRec->getDefinition()) {
1148         addedClassSubobject(FieldRec);
1149 
1150         // We may need to perform overload resolution to determine whether a
1151         // field can be moved if it's const or volatile qualified.
1152         if (T.getCVRQualifiers() & (Qualifiers::Const | Qualifiers::Volatile)) {
1153           // We need to care about 'const' for the copy constructor because an
1154           // implicit copy constructor might be declared with a non-const
1155           // parameter.
1156           data().NeedOverloadResolutionForCopyConstructor = true;
1157           data().NeedOverloadResolutionForMoveConstructor = true;
1158           data().NeedOverloadResolutionForCopyAssignment = true;
1159           data().NeedOverloadResolutionForMoveAssignment = true;
1160         }
1161 
1162         // C++11 [class.ctor]p5, C++11 [class.copy]p11:
1163         //   A defaulted [special member] for a class X is defined as
1164         //   deleted if:
1165         //    -- X is a union-like class that has a variant member with a
1166         //       non-trivial [corresponding special member]
1167         if (isUnion()) {
1168           if (FieldRec->hasNonTrivialCopyConstructor())
1169             data().DefaultedCopyConstructorIsDeleted = true;
1170           if (FieldRec->hasNonTrivialMoveConstructor())
1171             data().DefaultedMoveConstructorIsDeleted = true;
1172           if (FieldRec->hasNonTrivialCopyAssignment())
1173             data().DefaultedCopyAssignmentIsDeleted = true;
1174           if (FieldRec->hasNonTrivialMoveAssignment())
1175             data().DefaultedMoveAssignmentIsDeleted = true;
1176           if (FieldRec->hasNonTrivialDestructor())
1177             data().DefaultedDestructorIsDeleted = true;
1178         }
1179 
1180         // For an anonymous union member, our overload resolution will perform
1181         // overload resolution for its members.
1182         if (Field->isAnonymousStructOrUnion()) {
1183           data().NeedOverloadResolutionForCopyConstructor |=
1184               FieldRec->data().NeedOverloadResolutionForCopyConstructor;
1185           data().NeedOverloadResolutionForMoveConstructor |=
1186               FieldRec->data().NeedOverloadResolutionForMoveConstructor;
1187           data().NeedOverloadResolutionForCopyAssignment |=
1188               FieldRec->data().NeedOverloadResolutionForCopyAssignment;
1189           data().NeedOverloadResolutionForMoveAssignment |=
1190               FieldRec->data().NeedOverloadResolutionForMoveAssignment;
1191           data().NeedOverloadResolutionForDestructor |=
1192               FieldRec->data().NeedOverloadResolutionForDestructor;
1193         }
1194 
1195         // C++0x [class.ctor]p5:
1196         //   A default constructor is trivial [...] if:
1197         //    -- for all the non-static data members of its class that are of
1198         //       class type (or array thereof), each such class has a trivial
1199         //       default constructor.
1200         if (!FieldRec->hasTrivialDefaultConstructor())
1201           data().HasTrivialSpecialMembers &= ~SMF_DefaultConstructor;
1202 
1203         // C++0x [class.copy]p13:
1204         //   A copy/move constructor for class X is trivial if [...]
1205         //    [...]
1206         //    -- for each non-static data member of X that is of class type (or
1207         //       an array thereof), the constructor selected to copy/move that
1208         //       member is trivial;
1209         if (!FieldRec->hasTrivialCopyConstructor())
1210           data().HasTrivialSpecialMembers &= ~SMF_CopyConstructor;
1211 
1212         if (!FieldRec->hasTrivialCopyConstructorForCall())
1213           data().HasTrivialSpecialMembersForCall &= ~SMF_CopyConstructor;
1214 
1215         // If the field doesn't have a simple move constructor, we'll eagerly
1216         // declare the move constructor for this class and we'll decide whether
1217         // it's trivial then.
1218         if (!FieldRec->hasTrivialMoveConstructor())
1219           data().HasTrivialSpecialMembers &= ~SMF_MoveConstructor;
1220 
1221         if (!FieldRec->hasTrivialMoveConstructorForCall())
1222           data().HasTrivialSpecialMembersForCall &= ~SMF_MoveConstructor;
1223 
1224         // C++0x [class.copy]p27:
1225         //   A copy/move assignment operator for class X is trivial if [...]
1226         //    [...]
1227         //    -- for each non-static data member of X that is of class type (or
1228         //       an array thereof), the assignment operator selected to
1229         //       copy/move that member is trivial;
1230         if (!FieldRec->hasTrivialCopyAssignment())
1231           data().HasTrivialSpecialMembers &= ~SMF_CopyAssignment;
1232         // If the field doesn't have a simple move assignment, we'll eagerly
1233         // declare the move assignment for this class and we'll decide whether
1234         // it's trivial then.
1235         if (!FieldRec->hasTrivialMoveAssignment())
1236           data().HasTrivialSpecialMembers &= ~SMF_MoveAssignment;
1237 
1238         if (!FieldRec->hasTrivialDestructor())
1239           data().HasTrivialSpecialMembers &= ~SMF_Destructor;
1240         if (!FieldRec->hasTrivialDestructorForCall())
1241           data().HasTrivialSpecialMembersForCall &= ~SMF_Destructor;
1242         if (!FieldRec->hasIrrelevantDestructor())
1243           data().HasIrrelevantDestructor = false;
1244         if (FieldRec->isAnyDestructorNoReturn())
1245           data().IsAnyDestructorNoReturn = true;
1246         if (FieldRec->hasObjectMember())
1247           setHasObjectMember(true);
1248         if (FieldRec->hasVolatileMember())
1249           setHasVolatileMember(true);
1250         if (FieldRec->getArgPassingRestrictions() ==
1251             RecordDecl::APK_CanNeverPassInRegs)
1252           setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
1253 
1254         // C++0x [class]p7:
1255         //   A standard-layout class is a class that:
1256         //    -- has no non-static data members of type non-standard-layout
1257         //       class (or array of such types) [...]
1258         if (!FieldRec->isStandardLayout())
1259           data().IsStandardLayout = false;
1260         if (!FieldRec->isCXX11StandardLayout())
1261           data().IsCXX11StandardLayout = false;
1262 
1263         // C++2a [class]p7:
1264         //   A standard-layout class is a class that:
1265         //    [...]
1266         //    -- has no element of the set M(S) of types as a base class.
1267         if (data().IsStandardLayout &&
1268             (isUnion() || IsFirstField || IsZeroSize) &&
1269             hasSubobjectAtOffsetZeroOfEmptyBaseType(Context, FieldRec))
1270           data().IsStandardLayout = false;
1271 
1272         // C++11 [class]p7:
1273         //   A standard-layout class is a class that:
1274         //    -- has no base classes of the same type as the first non-static
1275         //       data member
1276         if (data().IsCXX11StandardLayout && IsFirstField) {
1277           // FIXME: We should check all base classes here, not just direct
1278           // base classes.
1279           for (const auto &BI : bases()) {
1280             if (Context.hasSameUnqualifiedType(BI.getType(), T)) {
1281               data().IsCXX11StandardLayout = false;
1282               break;
1283             }
1284           }
1285         }
1286 
1287         // Keep track of the presence of mutable fields.
1288         if (FieldRec->hasMutableFields())
1289           data().HasMutableFields = true;
1290 
1291         if (Field->isMutable()) {
1292           // Our copy constructor/assignment might call something other than
1293           // the subobject's copy constructor/assignment if it's mutable and of
1294           // class type.
1295           data().NeedOverloadResolutionForCopyConstructor = true;
1296           data().NeedOverloadResolutionForCopyAssignment = true;
1297         }
1298 
1299         // C++11 [class.copy]p13:
1300         //   If the implicitly-defined constructor would satisfy the
1301         //   requirements of a constexpr constructor, the implicitly-defined
1302         //   constructor is constexpr.
1303         // C++11 [dcl.constexpr]p4:
1304         //    -- every constructor involved in initializing non-static data
1305         //       members [...] shall be a constexpr constructor
1306         if (!Field->hasInClassInitializer() &&
1307             !FieldRec->hasConstexprDefaultConstructor() && !isUnion())
1308           // The standard requires any in-class initializer to be a constant
1309           // expression. We consider this to be a defect.
1310           data().DefaultedDefaultConstructorIsConstexpr = false;
1311 
1312         // C++11 [class.copy]p8:
1313         //   The implicitly-declared copy constructor for a class X will have
1314         //   the form 'X::X(const X&)' if each potentially constructed subobject
1315         //   of a class type M (or array thereof) has a copy constructor whose
1316         //   first parameter is of type 'const M&' or 'const volatile M&'.
1317         if (!FieldRec->hasCopyConstructorWithConstParam())
1318           data().ImplicitCopyConstructorCanHaveConstParamForNonVBase = false;
1319 
1320         // C++11 [class.copy]p18:
1321         //   The implicitly-declared copy assignment oeprator for a class X will
1322         //   have the form 'X& X::operator=(const X&)' if [...] for all the
1323         //   non-static data members of X that are of a class type M (or array
1324         //   thereof), each such class type has a copy assignment operator whose
1325         //   parameter is of type 'const M&', 'const volatile M&' or 'M'.
1326         if (!FieldRec->hasCopyAssignmentWithConstParam())
1327           data().ImplicitCopyAssignmentHasConstParam = false;
1328 
1329         if (FieldRec->hasUninitializedReferenceMember() &&
1330             !Field->hasInClassInitializer())
1331           data().HasUninitializedReferenceMember = true;
1332 
1333         // C++11 [class.union]p8, DR1460:
1334         //   a non-static data member of an anonymous union that is a member of
1335         //   X is also a variant member of X.
1336         if (FieldRec->hasVariantMembers() &&
1337             Field->isAnonymousStructOrUnion())
1338           data().HasVariantMembers = true;
1339       }
1340     } else {
1341       // Base element type of field is a non-class type.
1342       if (!T->isLiteralType(Context) ||
1343           (!Field->hasInClassInitializer() && !isUnion() &&
1344            !Context.getLangOpts().CPlusPlus20))
1345         data().DefaultedDefaultConstructorIsConstexpr = false;
1346 
1347       // C++11 [class.copy]p23:
1348       //   A defaulted copy/move assignment operator for a class X is defined
1349       //   as deleted if X has:
1350       //    -- a non-static data member of const non-class type (or array
1351       //       thereof)
1352       if (T.isConstQualified()) {
1353         data().DefaultedCopyAssignmentIsDeleted = true;
1354         data().DefaultedMoveAssignmentIsDeleted = true;
1355       }
1356 
1357       // C++20 [temp.param]p7:
1358       //   A structural type is [...] a literal class type [for which] the
1359       //   types of all non-static data members are structural types or
1360       //   (possibly multidimensional) array thereof
1361       // We deal with class types elsewhere.
1362       if (!T->isStructuralType())
1363         data().StructuralIfLiteral = false;
1364     }
1365 
1366     // C++14 [meta.unary.prop]p4:
1367     //   T is a class type [...] with [...] no non-static data members other
1368     //   than subobjects of zero size
1369     if (data().Empty && !IsZeroSize)
1370       data().Empty = false;
1371   }
1372 
1373   // Handle using declarations of conversion functions.
1374   if (auto *Shadow = dyn_cast<UsingShadowDecl>(D)) {
1375     if (Shadow->getDeclName().getNameKind()
1376           == DeclarationName::CXXConversionFunctionName) {
1377       ASTContext &Ctx = getASTContext();
1378       data().Conversions.get(Ctx).addDecl(Ctx, Shadow, Shadow->getAccess());
1379     }
1380   }
1381 
1382   if (const auto *Using = dyn_cast<UsingDecl>(D)) {
1383     if (Using->getDeclName().getNameKind() ==
1384         DeclarationName::CXXConstructorName) {
1385       data().HasInheritedConstructor = true;
1386       // C++1z [dcl.init.aggr]p1:
1387       //  An aggregate is [...] a class [...] with no inherited constructors
1388       data().Aggregate = false;
1389     }
1390 
1391     if (Using->getDeclName().getCXXOverloadedOperator() == OO_Equal)
1392       data().HasInheritedAssignment = true;
1393   }
1394 }
1395 
1396 void CXXRecordDecl::finishedDefaultedOrDeletedMember(CXXMethodDecl *D) {
1397   assert(!D->isImplicit() && !D->isUserProvided());
1398 
1399   // The kind of special member this declaration is, if any.
1400   unsigned SMKind = 0;
1401 
1402   if (const auto *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1403     if (Constructor->isDefaultConstructor()) {
1404       SMKind |= SMF_DefaultConstructor;
1405       if (Constructor->isConstexpr())
1406         data().HasConstexprDefaultConstructor = true;
1407     }
1408     if (Constructor->isCopyConstructor())
1409       SMKind |= SMF_CopyConstructor;
1410     else if (Constructor->isMoveConstructor())
1411       SMKind |= SMF_MoveConstructor;
1412     else if (Constructor->isConstexpr())
1413       // We may now know that the constructor is constexpr.
1414       data().HasConstexprNonCopyMoveConstructor = true;
1415   } else if (isa<CXXDestructorDecl>(D)) {
1416     SMKind |= SMF_Destructor;
1417     if (!D->isTrivial() || D->getAccess() != AS_public || D->isDeleted())
1418       data().HasIrrelevantDestructor = false;
1419   } else if (D->isCopyAssignmentOperator())
1420     SMKind |= SMF_CopyAssignment;
1421   else if (D->isMoveAssignmentOperator())
1422     SMKind |= SMF_MoveAssignment;
1423 
1424   // Update which trivial / non-trivial special members we have.
1425   // addedMember will have skipped this step for this member.
1426   if (D->isTrivial())
1427     data().HasTrivialSpecialMembers |= SMKind;
1428   else
1429     data().DeclaredNonTrivialSpecialMembers |= SMKind;
1430 }
1431 
1432 void CXXRecordDecl::setCaptures(ASTContext &Context,
1433                                 ArrayRef<LambdaCapture> Captures) {
1434   CXXRecordDecl::LambdaDefinitionData &Data = getLambdaData();
1435 
1436   // Copy captures.
1437   Data.NumCaptures = Captures.size();
1438   Data.NumExplicitCaptures = 0;
1439   Data.Captures = (LambdaCapture *)Context.Allocate(sizeof(LambdaCapture) *
1440                                                     Captures.size());
1441   LambdaCapture *ToCapture = Data.Captures;
1442   for (unsigned I = 0, N = Captures.size(); I != N; ++I) {
1443     if (Captures[I].isExplicit())
1444       ++Data.NumExplicitCaptures;
1445 
1446     *ToCapture++ = Captures[I];
1447   }
1448 
1449   if (!lambdaIsDefaultConstructibleAndAssignable())
1450     Data.DefaultedCopyAssignmentIsDeleted = true;
1451 }
1452 
1453 void CXXRecordDecl::setTrivialForCallFlags(CXXMethodDecl *D) {
1454   unsigned SMKind = 0;
1455 
1456   if (const auto *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1457     if (Constructor->isCopyConstructor())
1458       SMKind = SMF_CopyConstructor;
1459     else if (Constructor->isMoveConstructor())
1460       SMKind = SMF_MoveConstructor;
1461   } else if (isa<CXXDestructorDecl>(D))
1462     SMKind = SMF_Destructor;
1463 
1464   if (D->isTrivialForCall())
1465     data().HasTrivialSpecialMembersForCall |= SMKind;
1466   else
1467     data().DeclaredNonTrivialSpecialMembersForCall |= SMKind;
1468 }
1469 
1470 bool CXXRecordDecl::isCLike() const {
1471   if (getTagKind() == TTK_Class || getTagKind() == TTK_Interface ||
1472       !TemplateOrInstantiation.isNull())
1473     return false;
1474   if (!hasDefinition())
1475     return true;
1476 
1477   return isPOD() && data().HasOnlyCMembers;
1478 }
1479 
1480 bool CXXRecordDecl::isGenericLambda() const {
1481   if (!isLambda()) return false;
1482   return getLambdaData().IsGenericLambda;
1483 }
1484 
1485 #ifndef NDEBUG
1486 static bool allLookupResultsAreTheSame(const DeclContext::lookup_result &R) {
1487   for (auto *D : R)
1488     if (!declaresSameEntity(D, R.front()))
1489       return false;
1490   return true;
1491 }
1492 #endif
1493 
1494 static NamedDecl* getLambdaCallOperatorHelper(const CXXRecordDecl &RD) {
1495   if (!RD.isLambda()) return nullptr;
1496   DeclarationName Name =
1497     RD.getASTContext().DeclarationNames.getCXXOperatorName(OO_Call);
1498   DeclContext::lookup_result Calls = RD.lookup(Name);
1499 
1500   assert(!Calls.empty() && "Missing lambda call operator!");
1501   assert(allLookupResultsAreTheSame(Calls) &&
1502          "More than one lambda call operator!");
1503   return Calls.front();
1504 }
1505 
1506 FunctionTemplateDecl* CXXRecordDecl::getDependentLambdaCallOperator() const {
1507   NamedDecl *CallOp = getLambdaCallOperatorHelper(*this);
1508   return  dyn_cast_or_null<FunctionTemplateDecl>(CallOp);
1509 }
1510 
1511 CXXMethodDecl *CXXRecordDecl::getLambdaCallOperator() const {
1512   NamedDecl *CallOp = getLambdaCallOperatorHelper(*this);
1513 
1514   if (CallOp == nullptr)
1515     return nullptr;
1516 
1517   if (const auto *CallOpTmpl = dyn_cast<FunctionTemplateDecl>(CallOp))
1518     return cast<CXXMethodDecl>(CallOpTmpl->getTemplatedDecl());
1519 
1520   return cast<CXXMethodDecl>(CallOp);
1521 }
1522 
1523 CXXMethodDecl* CXXRecordDecl::getLambdaStaticInvoker() const {
1524   CXXMethodDecl *CallOp = getLambdaCallOperator();
1525   CallingConv CC = CallOp->getType()->castAs<FunctionType>()->getCallConv();
1526   return getLambdaStaticInvoker(CC);
1527 }
1528 
1529 static DeclContext::lookup_result
1530 getLambdaStaticInvokers(const CXXRecordDecl &RD) {
1531   assert(RD.isLambda() && "Must be a lambda");
1532   DeclarationName Name =
1533       &RD.getASTContext().Idents.get(getLambdaStaticInvokerName());
1534   return RD.lookup(Name);
1535 }
1536 
1537 static CXXMethodDecl *getInvokerAsMethod(NamedDecl *ND) {
1538   if (const auto *InvokerTemplate = dyn_cast<FunctionTemplateDecl>(ND))
1539     return cast<CXXMethodDecl>(InvokerTemplate->getTemplatedDecl());
1540   return cast<CXXMethodDecl>(ND);
1541 }
1542 
1543 CXXMethodDecl *CXXRecordDecl::getLambdaStaticInvoker(CallingConv CC) const {
1544   if (!isLambda())
1545     return nullptr;
1546   DeclContext::lookup_result Invoker = getLambdaStaticInvokers(*this);
1547 
1548   for (NamedDecl *ND : Invoker) {
1549     const auto *FTy =
1550         cast<ValueDecl>(ND->getAsFunction())->getType()->castAs<FunctionType>();
1551     if (FTy->getCallConv() == CC)
1552       return getInvokerAsMethod(ND);
1553   }
1554 
1555   return nullptr;
1556 }
1557 
1558 void CXXRecordDecl::getCaptureFields(
1559        llvm::DenseMap<const VarDecl *, FieldDecl *> &Captures,
1560        FieldDecl *&ThisCapture) const {
1561   Captures.clear();
1562   ThisCapture = nullptr;
1563 
1564   LambdaDefinitionData &Lambda = getLambdaData();
1565   RecordDecl::field_iterator Field = field_begin();
1566   for (const LambdaCapture *C = Lambda.Captures, *CEnd = C + Lambda.NumCaptures;
1567        C != CEnd; ++C, ++Field) {
1568     if (C->capturesThis())
1569       ThisCapture = *Field;
1570     else if (C->capturesVariable())
1571       Captures[C->getCapturedVar()] = *Field;
1572   }
1573   assert(Field == field_end());
1574 }
1575 
1576 TemplateParameterList *
1577 CXXRecordDecl::getGenericLambdaTemplateParameterList() const {
1578   if (!isGenericLambda()) return nullptr;
1579   CXXMethodDecl *CallOp = getLambdaCallOperator();
1580   if (FunctionTemplateDecl *Tmpl = CallOp->getDescribedFunctionTemplate())
1581     return Tmpl->getTemplateParameters();
1582   return nullptr;
1583 }
1584 
1585 ArrayRef<NamedDecl *>
1586 CXXRecordDecl::getLambdaExplicitTemplateParameters() const {
1587   TemplateParameterList *List = getGenericLambdaTemplateParameterList();
1588   if (!List)
1589     return {};
1590 
1591   assert(std::is_partitioned(List->begin(), List->end(),
1592                              [](const NamedDecl *D) { return !D->isImplicit(); })
1593          && "Explicit template params should be ordered before implicit ones");
1594 
1595   const auto ExplicitEnd = llvm::partition_point(
1596       *List, [](const NamedDecl *D) { return !D->isImplicit(); });
1597   return llvm::makeArrayRef(List->begin(), ExplicitEnd);
1598 }
1599 
1600 Decl *CXXRecordDecl::getLambdaContextDecl() const {
1601   assert(isLambda() && "Not a lambda closure type!");
1602   ExternalASTSource *Source = getParentASTContext().getExternalSource();
1603   return getLambdaData().ContextDecl.get(Source);
1604 }
1605 
1606 void CXXRecordDecl::setDeviceLambdaManglingNumber(unsigned Num) const {
1607   assert(isLambda() && "Not a lambda closure type!");
1608   if (Num)
1609     getASTContext().DeviceLambdaManglingNumbers[this] = Num;
1610 }
1611 
1612 unsigned CXXRecordDecl::getDeviceLambdaManglingNumber() const {
1613   assert(isLambda() && "Not a lambda closure type!");
1614   auto I = getASTContext().DeviceLambdaManglingNumbers.find(this);
1615   if (I != getASTContext().DeviceLambdaManglingNumbers.end())
1616     return I->second;
1617   return 0;
1618 }
1619 
1620 static CanQualType GetConversionType(ASTContext &Context, NamedDecl *Conv) {
1621   QualType T =
1622       cast<CXXConversionDecl>(Conv->getUnderlyingDecl()->getAsFunction())
1623           ->getConversionType();
1624   return Context.getCanonicalType(T);
1625 }
1626 
1627 /// Collect the visible conversions of a base class.
1628 ///
1629 /// \param Record a base class of the class we're considering
1630 /// \param InVirtual whether this base class is a virtual base (or a base
1631 ///   of a virtual base)
1632 /// \param Access the access along the inheritance path to this base
1633 /// \param ParentHiddenTypes the conversions provided by the inheritors
1634 ///   of this base
1635 /// \param Output the set to which to add conversions from non-virtual bases
1636 /// \param VOutput the set to which to add conversions from virtual bases
1637 /// \param HiddenVBaseCs the set of conversions which were hidden in a
1638 ///   virtual base along some inheritance path
1639 static void CollectVisibleConversions(
1640     ASTContext &Context, const CXXRecordDecl *Record, bool InVirtual,
1641     AccessSpecifier Access,
1642     const llvm::SmallPtrSet<CanQualType, 8> &ParentHiddenTypes,
1643     ASTUnresolvedSet &Output, UnresolvedSetImpl &VOutput,
1644     llvm::SmallPtrSet<NamedDecl *, 8> &HiddenVBaseCs) {
1645   // The set of types which have conversions in this class or its
1646   // subclasses.  As an optimization, we don't copy the derived set
1647   // unless it might change.
1648   const llvm::SmallPtrSet<CanQualType, 8> *HiddenTypes = &ParentHiddenTypes;
1649   llvm::SmallPtrSet<CanQualType, 8> HiddenTypesBuffer;
1650 
1651   // Collect the direct conversions and figure out which conversions
1652   // will be hidden in the subclasses.
1653   CXXRecordDecl::conversion_iterator ConvI = Record->conversion_begin();
1654   CXXRecordDecl::conversion_iterator ConvE = Record->conversion_end();
1655   if (ConvI != ConvE) {
1656     HiddenTypesBuffer = ParentHiddenTypes;
1657     HiddenTypes = &HiddenTypesBuffer;
1658 
1659     for (CXXRecordDecl::conversion_iterator I = ConvI; I != ConvE; ++I) {
1660       CanQualType ConvType(GetConversionType(Context, I.getDecl()));
1661       bool Hidden = ParentHiddenTypes.count(ConvType);
1662       if (!Hidden)
1663         HiddenTypesBuffer.insert(ConvType);
1664 
1665       // If this conversion is hidden and we're in a virtual base,
1666       // remember that it's hidden along some inheritance path.
1667       if (Hidden && InVirtual)
1668         HiddenVBaseCs.insert(cast<NamedDecl>(I.getDecl()->getCanonicalDecl()));
1669 
1670       // If this conversion isn't hidden, add it to the appropriate output.
1671       else if (!Hidden) {
1672         AccessSpecifier IAccess
1673           = CXXRecordDecl::MergeAccess(Access, I.getAccess());
1674 
1675         if (InVirtual)
1676           VOutput.addDecl(I.getDecl(), IAccess);
1677         else
1678           Output.addDecl(Context, I.getDecl(), IAccess);
1679       }
1680     }
1681   }
1682 
1683   // Collect information recursively from any base classes.
1684   for (const auto &I : Record->bases()) {
1685     const auto *RT = I.getType()->getAs<RecordType>();
1686     if (!RT) continue;
1687 
1688     AccessSpecifier BaseAccess
1689       = CXXRecordDecl::MergeAccess(Access, I.getAccessSpecifier());
1690     bool BaseInVirtual = InVirtual || I.isVirtual();
1691 
1692     auto *Base = cast<CXXRecordDecl>(RT->getDecl());
1693     CollectVisibleConversions(Context, Base, BaseInVirtual, BaseAccess,
1694                               *HiddenTypes, Output, VOutput, HiddenVBaseCs);
1695   }
1696 }
1697 
1698 /// Collect the visible conversions of a class.
1699 ///
1700 /// This would be extremely straightforward if it weren't for virtual
1701 /// bases.  It might be worth special-casing that, really.
1702 static void CollectVisibleConversions(ASTContext &Context,
1703                                       const CXXRecordDecl *Record,
1704                                       ASTUnresolvedSet &Output) {
1705   // The collection of all conversions in virtual bases that we've
1706   // found.  These will be added to the output as long as they don't
1707   // appear in the hidden-conversions set.
1708   UnresolvedSet<8> VBaseCs;
1709 
1710   // The set of conversions in virtual bases that we've determined to
1711   // be hidden.
1712   llvm::SmallPtrSet<NamedDecl*, 8> HiddenVBaseCs;
1713 
1714   // The set of types hidden by classes derived from this one.
1715   llvm::SmallPtrSet<CanQualType, 8> HiddenTypes;
1716 
1717   // Go ahead and collect the direct conversions and add them to the
1718   // hidden-types set.
1719   CXXRecordDecl::conversion_iterator ConvI = Record->conversion_begin();
1720   CXXRecordDecl::conversion_iterator ConvE = Record->conversion_end();
1721   Output.append(Context, ConvI, ConvE);
1722   for (; ConvI != ConvE; ++ConvI)
1723     HiddenTypes.insert(GetConversionType(Context, ConvI.getDecl()));
1724 
1725   // Recursively collect conversions from base classes.
1726   for (const auto &I : Record->bases()) {
1727     const auto *RT = I.getType()->getAs<RecordType>();
1728     if (!RT) continue;
1729 
1730     CollectVisibleConversions(Context, cast<CXXRecordDecl>(RT->getDecl()),
1731                               I.isVirtual(), I.getAccessSpecifier(),
1732                               HiddenTypes, Output, VBaseCs, HiddenVBaseCs);
1733   }
1734 
1735   // Add any unhidden conversions provided by virtual bases.
1736   for (UnresolvedSetIterator I = VBaseCs.begin(), E = VBaseCs.end();
1737          I != E; ++I) {
1738     if (!HiddenVBaseCs.count(cast<NamedDecl>(I.getDecl()->getCanonicalDecl())))
1739       Output.addDecl(Context, I.getDecl(), I.getAccess());
1740   }
1741 }
1742 
1743 /// getVisibleConversionFunctions - get all conversion functions visible
1744 /// in current class; including conversion function templates.
1745 llvm::iterator_range<CXXRecordDecl::conversion_iterator>
1746 CXXRecordDecl::getVisibleConversionFunctions() const {
1747   ASTContext &Ctx = getASTContext();
1748 
1749   ASTUnresolvedSet *Set;
1750   if (bases_begin() == bases_end()) {
1751     // If root class, all conversions are visible.
1752     Set = &data().Conversions.get(Ctx);
1753   } else {
1754     Set = &data().VisibleConversions.get(Ctx);
1755     // If visible conversion list is not evaluated, evaluate it.
1756     if (!data().ComputedVisibleConversions) {
1757       CollectVisibleConversions(Ctx, this, *Set);
1758       data().ComputedVisibleConversions = true;
1759     }
1760   }
1761   return llvm::make_range(Set->begin(), Set->end());
1762 }
1763 
1764 void CXXRecordDecl::removeConversion(const NamedDecl *ConvDecl) {
1765   // This operation is O(N) but extremely rare.  Sema only uses it to
1766   // remove UsingShadowDecls in a class that were followed by a direct
1767   // declaration, e.g.:
1768   //   class A : B {
1769   //     using B::operator int;
1770   //     operator int();
1771   //   };
1772   // This is uncommon by itself and even more uncommon in conjunction
1773   // with sufficiently large numbers of directly-declared conversions
1774   // that asymptotic behavior matters.
1775 
1776   ASTUnresolvedSet &Convs = data().Conversions.get(getASTContext());
1777   for (unsigned I = 0, E = Convs.size(); I != E; ++I) {
1778     if (Convs[I].getDecl() == ConvDecl) {
1779       Convs.erase(I);
1780       assert(!llvm::is_contained(Convs, ConvDecl) &&
1781              "conversion was found multiple times in unresolved set");
1782       return;
1783     }
1784   }
1785 
1786   llvm_unreachable("conversion not found in set!");
1787 }
1788 
1789 CXXRecordDecl *CXXRecordDecl::getInstantiatedFromMemberClass() const {
1790   if (MemberSpecializationInfo *MSInfo = getMemberSpecializationInfo())
1791     return cast<CXXRecordDecl>(MSInfo->getInstantiatedFrom());
1792 
1793   return nullptr;
1794 }
1795 
1796 MemberSpecializationInfo *CXXRecordDecl::getMemberSpecializationInfo() const {
1797   return TemplateOrInstantiation.dyn_cast<MemberSpecializationInfo *>();
1798 }
1799 
1800 void
1801 CXXRecordDecl::setInstantiationOfMemberClass(CXXRecordDecl *RD,
1802                                              TemplateSpecializationKind TSK) {
1803   assert(TemplateOrInstantiation.isNull() &&
1804          "Previous template or instantiation?");
1805   assert(!isa<ClassTemplatePartialSpecializationDecl>(this));
1806   TemplateOrInstantiation
1807     = new (getASTContext()) MemberSpecializationInfo(RD, TSK);
1808 }
1809 
1810 ClassTemplateDecl *CXXRecordDecl::getDescribedClassTemplate() const {
1811   return TemplateOrInstantiation.dyn_cast<ClassTemplateDecl *>();
1812 }
1813 
1814 void CXXRecordDecl::setDescribedClassTemplate(ClassTemplateDecl *Template) {
1815   TemplateOrInstantiation = Template;
1816 }
1817 
1818 TemplateSpecializationKind CXXRecordDecl::getTemplateSpecializationKind() const{
1819   if (const auto *Spec = dyn_cast<ClassTemplateSpecializationDecl>(this))
1820     return Spec->getSpecializationKind();
1821 
1822   if (MemberSpecializationInfo *MSInfo = getMemberSpecializationInfo())
1823     return MSInfo->getTemplateSpecializationKind();
1824 
1825   return TSK_Undeclared;
1826 }
1827 
1828 void
1829 CXXRecordDecl::setTemplateSpecializationKind(TemplateSpecializationKind TSK) {
1830   if (auto *Spec = dyn_cast<ClassTemplateSpecializationDecl>(this)) {
1831     Spec->setSpecializationKind(TSK);
1832     return;
1833   }
1834 
1835   if (MemberSpecializationInfo *MSInfo = getMemberSpecializationInfo()) {
1836     MSInfo->setTemplateSpecializationKind(TSK);
1837     return;
1838   }
1839 
1840   llvm_unreachable("Not a class template or member class specialization");
1841 }
1842 
1843 const CXXRecordDecl *CXXRecordDecl::getTemplateInstantiationPattern() const {
1844   auto GetDefinitionOrSelf =
1845       [](const CXXRecordDecl *D) -> const CXXRecordDecl * {
1846     if (auto *Def = D->getDefinition())
1847       return Def;
1848     return D;
1849   };
1850 
1851   // If it's a class template specialization, find the template or partial
1852   // specialization from which it was instantiated.
1853   if (auto *TD = dyn_cast<ClassTemplateSpecializationDecl>(this)) {
1854     auto From = TD->getInstantiatedFrom();
1855     if (auto *CTD = From.dyn_cast<ClassTemplateDecl *>()) {
1856       while (auto *NewCTD = CTD->getInstantiatedFromMemberTemplate()) {
1857         if (NewCTD->isMemberSpecialization())
1858           break;
1859         CTD = NewCTD;
1860       }
1861       return GetDefinitionOrSelf(CTD->getTemplatedDecl());
1862     }
1863     if (auto *CTPSD =
1864             From.dyn_cast<ClassTemplatePartialSpecializationDecl *>()) {
1865       while (auto *NewCTPSD = CTPSD->getInstantiatedFromMember()) {
1866         if (NewCTPSD->isMemberSpecialization())
1867           break;
1868         CTPSD = NewCTPSD;
1869       }
1870       return GetDefinitionOrSelf(CTPSD);
1871     }
1872   }
1873 
1874   if (MemberSpecializationInfo *MSInfo = getMemberSpecializationInfo()) {
1875     if (isTemplateInstantiation(MSInfo->getTemplateSpecializationKind())) {
1876       const CXXRecordDecl *RD = this;
1877       while (auto *NewRD = RD->getInstantiatedFromMemberClass())
1878         RD = NewRD;
1879       return GetDefinitionOrSelf(RD);
1880     }
1881   }
1882 
1883   assert(!isTemplateInstantiation(this->getTemplateSpecializationKind()) &&
1884          "couldn't find pattern for class template instantiation");
1885   return nullptr;
1886 }
1887 
1888 CXXDestructorDecl *CXXRecordDecl::getDestructor() const {
1889   ASTContext &Context = getASTContext();
1890   QualType ClassType = Context.getTypeDeclType(this);
1891 
1892   DeclarationName Name
1893     = Context.DeclarationNames.getCXXDestructorName(
1894                                           Context.getCanonicalType(ClassType));
1895 
1896   DeclContext::lookup_result R = lookup(Name);
1897 
1898   return R.empty() ? nullptr : dyn_cast<CXXDestructorDecl>(R.front());
1899 }
1900 
1901 static bool isDeclContextInNamespace(const DeclContext *DC) {
1902   while (!DC->isTranslationUnit()) {
1903     if (DC->isNamespace())
1904       return true;
1905     DC = DC->getParent();
1906   }
1907   return false;
1908 }
1909 
1910 bool CXXRecordDecl::isInterfaceLike() const {
1911   assert(hasDefinition() && "checking for interface-like without a definition");
1912   // All __interfaces are inheritently interface-like.
1913   if (isInterface())
1914     return true;
1915 
1916   // Interface-like types cannot have a user declared constructor, destructor,
1917   // friends, VBases, conversion functions, or fields.  Additionally, lambdas
1918   // cannot be interface types.
1919   if (isLambda() || hasUserDeclaredConstructor() ||
1920       hasUserDeclaredDestructor() || !field_empty() || hasFriends() ||
1921       getNumVBases() > 0 || conversion_end() - conversion_begin() > 0)
1922     return false;
1923 
1924   // No interface-like type can have a method with a definition.
1925   for (const auto *const Method : methods())
1926     if (Method->isDefined() && !Method->isImplicit())
1927       return false;
1928 
1929   // Check "Special" types.
1930   const auto *Uuid = getAttr<UuidAttr>();
1931   // MS SDK declares IUnknown/IDispatch both in the root of a TU, or in an
1932   // extern C++ block directly in the TU.  These are only valid if in one
1933   // of these two situations.
1934   if (Uuid && isStruct() && !getDeclContext()->isExternCContext() &&
1935       !isDeclContextInNamespace(getDeclContext()) &&
1936       ((getName() == "IUnknown" &&
1937         Uuid->getGuid() == "00000000-0000-0000-C000-000000000046") ||
1938        (getName() == "IDispatch" &&
1939         Uuid->getGuid() == "00020400-0000-0000-C000-000000000046"))) {
1940     if (getNumBases() > 0)
1941       return false;
1942     return true;
1943   }
1944 
1945   // FIXME: Any access specifiers is supposed to make this no longer interface
1946   // like.
1947 
1948   // If this isn't a 'special' type, it must have a single interface-like base.
1949   if (getNumBases() != 1)
1950     return false;
1951 
1952   const auto BaseSpec = *bases_begin();
1953   if (BaseSpec.isVirtual() || BaseSpec.getAccessSpecifier() != AS_public)
1954     return false;
1955   const auto *Base = BaseSpec.getType()->getAsCXXRecordDecl();
1956   if (Base->isInterface() || !Base->isInterfaceLike())
1957     return false;
1958   return true;
1959 }
1960 
1961 void CXXRecordDecl::completeDefinition() {
1962   completeDefinition(nullptr);
1963 }
1964 
1965 void CXXRecordDecl::completeDefinition(CXXFinalOverriderMap *FinalOverriders) {
1966   RecordDecl::completeDefinition();
1967 
1968   // If the class may be abstract (but hasn't been marked as such), check for
1969   // any pure final overriders.
1970   if (mayBeAbstract()) {
1971     CXXFinalOverriderMap MyFinalOverriders;
1972     if (!FinalOverriders) {
1973       getFinalOverriders(MyFinalOverriders);
1974       FinalOverriders = &MyFinalOverriders;
1975     }
1976 
1977     bool Done = false;
1978     for (CXXFinalOverriderMap::iterator M = FinalOverriders->begin(),
1979                                      MEnd = FinalOverriders->end();
1980          M != MEnd && !Done; ++M) {
1981       for (OverridingMethods::iterator SO = M->second.begin(),
1982                                     SOEnd = M->second.end();
1983            SO != SOEnd && !Done; ++SO) {
1984         assert(SO->second.size() > 0 &&
1985                "All virtual functions have overriding virtual functions");
1986 
1987         // C++ [class.abstract]p4:
1988         //   A class is abstract if it contains or inherits at least one
1989         //   pure virtual function for which the final overrider is pure
1990         //   virtual.
1991         if (SO->second.front().Method->isPure()) {
1992           data().Abstract = true;
1993           Done = true;
1994           break;
1995         }
1996       }
1997     }
1998   }
1999 
2000   // Set access bits correctly on the directly-declared conversions.
2001   for (conversion_iterator I = conversion_begin(), E = conversion_end();
2002        I != E; ++I)
2003     I.setAccess((*I)->getAccess());
2004 }
2005 
2006 bool CXXRecordDecl::mayBeAbstract() const {
2007   if (data().Abstract || isInvalidDecl() || !data().Polymorphic ||
2008       isDependentContext())
2009     return false;
2010 
2011   for (const auto &B : bases()) {
2012     const auto *BaseDecl =
2013         cast<CXXRecordDecl>(B.getType()->castAs<RecordType>()->getDecl());
2014     if (BaseDecl->isAbstract())
2015       return true;
2016   }
2017 
2018   return false;
2019 }
2020 
2021 bool CXXRecordDecl::isEffectivelyFinal() const {
2022   auto *Def = getDefinition();
2023   if (!Def)
2024     return false;
2025   if (Def->hasAttr<FinalAttr>())
2026     return true;
2027   if (const auto *Dtor = Def->getDestructor())
2028     if (Dtor->hasAttr<FinalAttr>())
2029       return true;
2030   return false;
2031 }
2032 
2033 void CXXDeductionGuideDecl::anchor() {}
2034 
2035 bool ExplicitSpecifier::isEquivalent(const ExplicitSpecifier Other) const {
2036   if ((getKind() != Other.getKind() ||
2037        getKind() == ExplicitSpecKind::Unresolved)) {
2038     if (getKind() == ExplicitSpecKind::Unresolved &&
2039         Other.getKind() == ExplicitSpecKind::Unresolved) {
2040       ODRHash SelfHash, OtherHash;
2041       SelfHash.AddStmt(getExpr());
2042       OtherHash.AddStmt(Other.getExpr());
2043       return SelfHash.CalculateHash() == OtherHash.CalculateHash();
2044     } else
2045       return false;
2046   }
2047   return true;
2048 }
2049 
2050 ExplicitSpecifier ExplicitSpecifier::getFromDecl(FunctionDecl *Function) {
2051   switch (Function->getDeclKind()) {
2052   case Decl::Kind::CXXConstructor:
2053     return cast<CXXConstructorDecl>(Function)->getExplicitSpecifier();
2054   case Decl::Kind::CXXConversion:
2055     return cast<CXXConversionDecl>(Function)->getExplicitSpecifier();
2056   case Decl::Kind::CXXDeductionGuide:
2057     return cast<CXXDeductionGuideDecl>(Function)->getExplicitSpecifier();
2058   default:
2059     return {};
2060   }
2061 }
2062 
2063 CXXDeductionGuideDecl *
2064 CXXDeductionGuideDecl::Create(ASTContext &C, DeclContext *DC,
2065                               SourceLocation StartLoc, ExplicitSpecifier ES,
2066                               const DeclarationNameInfo &NameInfo, QualType T,
2067                               TypeSourceInfo *TInfo, SourceLocation EndLocation,
2068                               CXXConstructorDecl *Ctor) {
2069   return new (C, DC) CXXDeductionGuideDecl(C, DC, StartLoc, ES, NameInfo, T,
2070                                            TInfo, EndLocation, Ctor);
2071 }
2072 
2073 CXXDeductionGuideDecl *CXXDeductionGuideDecl::CreateDeserialized(ASTContext &C,
2074                                                                  unsigned ID) {
2075   return new (C, ID) CXXDeductionGuideDecl(
2076       C, nullptr, SourceLocation(), ExplicitSpecifier(), DeclarationNameInfo(),
2077       QualType(), nullptr, SourceLocation(), nullptr);
2078 }
2079 
2080 RequiresExprBodyDecl *RequiresExprBodyDecl::Create(
2081     ASTContext &C, DeclContext *DC, SourceLocation StartLoc) {
2082   return new (C, DC) RequiresExprBodyDecl(C, DC, StartLoc);
2083 }
2084 
2085 RequiresExprBodyDecl *RequiresExprBodyDecl::CreateDeserialized(ASTContext &C,
2086                                                                unsigned ID) {
2087   return new (C, ID) RequiresExprBodyDecl(C, nullptr, SourceLocation());
2088 }
2089 
2090 void CXXMethodDecl::anchor() {}
2091 
2092 bool CXXMethodDecl::isStatic() const {
2093   const CXXMethodDecl *MD = getCanonicalDecl();
2094 
2095   if (MD->getStorageClass() == SC_Static)
2096     return true;
2097 
2098   OverloadedOperatorKind OOK = getDeclName().getCXXOverloadedOperator();
2099   return isStaticOverloadedOperator(OOK);
2100 }
2101 
2102 static bool recursivelyOverrides(const CXXMethodDecl *DerivedMD,
2103                                  const CXXMethodDecl *BaseMD) {
2104   for (const CXXMethodDecl *MD : DerivedMD->overridden_methods()) {
2105     if (MD->getCanonicalDecl() == BaseMD->getCanonicalDecl())
2106       return true;
2107     if (recursivelyOverrides(MD, BaseMD))
2108       return true;
2109   }
2110   return false;
2111 }
2112 
2113 CXXMethodDecl *
2114 CXXMethodDecl::getCorrespondingMethodDeclaredInClass(const CXXRecordDecl *RD,
2115                                                      bool MayBeBase) {
2116   if (this->getParent()->getCanonicalDecl() == RD->getCanonicalDecl())
2117     return this;
2118 
2119   // Lookup doesn't work for destructors, so handle them separately.
2120   if (isa<CXXDestructorDecl>(this)) {
2121     CXXMethodDecl *MD = RD->getDestructor();
2122     if (MD) {
2123       if (recursivelyOverrides(MD, this))
2124         return MD;
2125       if (MayBeBase && recursivelyOverrides(this, MD))
2126         return MD;
2127     }
2128     return nullptr;
2129   }
2130 
2131   for (auto *ND : RD->lookup(getDeclName())) {
2132     auto *MD = dyn_cast<CXXMethodDecl>(ND);
2133     if (!MD)
2134       continue;
2135     if (recursivelyOverrides(MD, this))
2136       return MD;
2137     if (MayBeBase && recursivelyOverrides(this, MD))
2138       return MD;
2139   }
2140 
2141   return nullptr;
2142 }
2143 
2144 CXXMethodDecl *
2145 CXXMethodDecl::getCorrespondingMethodInClass(const CXXRecordDecl *RD,
2146                                              bool MayBeBase) {
2147   if (auto *MD = getCorrespondingMethodDeclaredInClass(RD, MayBeBase))
2148     return MD;
2149 
2150   llvm::SmallVector<CXXMethodDecl*, 4> FinalOverriders;
2151   auto AddFinalOverrider = [&](CXXMethodDecl *D) {
2152     // If this function is overridden by a candidate final overrider, it is not
2153     // a final overrider.
2154     for (CXXMethodDecl *OtherD : FinalOverriders) {
2155       if (declaresSameEntity(D, OtherD) || recursivelyOverrides(OtherD, D))
2156         return;
2157     }
2158 
2159     // Other candidate final overriders might be overridden by this function.
2160     llvm::erase_if(FinalOverriders, [&](CXXMethodDecl *OtherD) {
2161       return recursivelyOverrides(D, OtherD);
2162     });
2163 
2164     FinalOverriders.push_back(D);
2165   };
2166 
2167   for (const auto &I : RD->bases()) {
2168     const RecordType *RT = I.getType()->getAs<RecordType>();
2169     if (!RT)
2170       continue;
2171     const auto *Base = cast<CXXRecordDecl>(RT->getDecl());
2172     if (CXXMethodDecl *D = this->getCorrespondingMethodInClass(Base))
2173       AddFinalOverrider(D);
2174   }
2175 
2176   return FinalOverriders.size() == 1 ? FinalOverriders.front() : nullptr;
2177 }
2178 
2179 CXXMethodDecl *
2180 CXXMethodDecl::Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2181                       const DeclarationNameInfo &NameInfo, QualType T,
2182                       TypeSourceInfo *TInfo, StorageClass SC, bool UsesFPIntrin,
2183                       bool isInline, ConstexprSpecKind ConstexprKind,
2184                       SourceLocation EndLocation,
2185                       Expr *TrailingRequiresClause) {
2186   return new (C, RD) CXXMethodDecl(
2187       CXXMethod, C, RD, StartLoc, NameInfo, T, TInfo, SC, UsesFPIntrin,
2188       isInline, ConstexprKind, EndLocation, TrailingRequiresClause);
2189 }
2190 
2191 CXXMethodDecl *CXXMethodDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2192   return new (C, ID) CXXMethodDecl(
2193       CXXMethod, C, nullptr, SourceLocation(), DeclarationNameInfo(),
2194       QualType(), nullptr, SC_None, false, false,
2195       ConstexprSpecKind::Unspecified, SourceLocation(), nullptr);
2196 }
2197 
2198 CXXMethodDecl *CXXMethodDecl::getDevirtualizedMethod(const Expr *Base,
2199                                                      bool IsAppleKext) {
2200   assert(isVirtual() && "this method is expected to be virtual");
2201 
2202   // When building with -fapple-kext, all calls must go through the vtable since
2203   // the kernel linker can do runtime patching of vtables.
2204   if (IsAppleKext)
2205     return nullptr;
2206 
2207   // If the member function is marked 'final', we know that it can't be
2208   // overridden and can therefore devirtualize it unless it's pure virtual.
2209   if (hasAttr<FinalAttr>())
2210     return isPure() ? nullptr : this;
2211 
2212   // If Base is unknown, we cannot devirtualize.
2213   if (!Base)
2214     return nullptr;
2215 
2216   // If the base expression (after skipping derived-to-base conversions) is a
2217   // class prvalue, then we can devirtualize.
2218   Base = Base->getBestDynamicClassTypeExpr();
2219   if (Base->isPRValue() && Base->getType()->isRecordType())
2220     return this;
2221 
2222   // If we don't even know what we would call, we can't devirtualize.
2223   const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType();
2224   if (!BestDynamicDecl)
2225     return nullptr;
2226 
2227   // There may be a method corresponding to MD in a derived class.
2228   CXXMethodDecl *DevirtualizedMethod =
2229       getCorrespondingMethodInClass(BestDynamicDecl);
2230 
2231   // If there final overrider in the dynamic type is ambiguous, we can't
2232   // devirtualize this call.
2233   if (!DevirtualizedMethod)
2234     return nullptr;
2235 
2236   // If that method is pure virtual, we can't devirtualize. If this code is
2237   // reached, the result would be UB, not a direct call to the derived class
2238   // function, and we can't assume the derived class function is defined.
2239   if (DevirtualizedMethod->isPure())
2240     return nullptr;
2241 
2242   // If that method is marked final, we can devirtualize it.
2243   if (DevirtualizedMethod->hasAttr<FinalAttr>())
2244     return DevirtualizedMethod;
2245 
2246   // Similarly, if the class itself or its destructor is marked 'final',
2247   // the class can't be derived from and we can therefore devirtualize the
2248   // member function call.
2249   if (BestDynamicDecl->isEffectivelyFinal())
2250     return DevirtualizedMethod;
2251 
2252   if (const auto *DRE = dyn_cast<DeclRefExpr>(Base)) {
2253     if (const auto *VD = dyn_cast<VarDecl>(DRE->getDecl()))
2254       if (VD->getType()->isRecordType())
2255         // This is a record decl. We know the type and can devirtualize it.
2256         return DevirtualizedMethod;
2257 
2258     return nullptr;
2259   }
2260 
2261   // We can devirtualize calls on an object accessed by a class member access
2262   // expression, since by C++11 [basic.life]p6 we know that it can't refer to
2263   // a derived class object constructed in the same location.
2264   if (const auto *ME = dyn_cast<MemberExpr>(Base)) {
2265     const ValueDecl *VD = ME->getMemberDecl();
2266     return VD->getType()->isRecordType() ? DevirtualizedMethod : nullptr;
2267   }
2268 
2269   // Likewise for calls on an object accessed by a (non-reference) pointer to
2270   // member access.
2271   if (auto *BO = dyn_cast<BinaryOperator>(Base)) {
2272     if (BO->isPtrMemOp()) {
2273       auto *MPT = BO->getRHS()->getType()->castAs<MemberPointerType>();
2274       if (MPT->getPointeeType()->isRecordType())
2275         return DevirtualizedMethod;
2276     }
2277   }
2278 
2279   // We can't devirtualize the call.
2280   return nullptr;
2281 }
2282 
2283 bool CXXMethodDecl::isUsualDeallocationFunction(
2284     SmallVectorImpl<const FunctionDecl *> &PreventedBy) const {
2285   assert(PreventedBy.empty() && "PreventedBy is expected to be empty");
2286   if (getOverloadedOperator() != OO_Delete &&
2287       getOverloadedOperator() != OO_Array_Delete)
2288     return false;
2289 
2290   // C++ [basic.stc.dynamic.deallocation]p2:
2291   //   A template instance is never a usual deallocation function,
2292   //   regardless of its signature.
2293   if (getPrimaryTemplate())
2294     return false;
2295 
2296   // C++ [basic.stc.dynamic.deallocation]p2:
2297   //   If a class T has a member deallocation function named operator delete
2298   //   with exactly one parameter, then that function is a usual (non-placement)
2299   //   deallocation function. [...]
2300   if (getNumParams() == 1)
2301     return true;
2302   unsigned UsualParams = 1;
2303 
2304   // C++ P0722:
2305   //   A destroying operator delete is a usual deallocation function if
2306   //   removing the std::destroying_delete_t parameter and changing the
2307   //   first parameter type from T* to void* results in the signature of
2308   //   a usual deallocation function.
2309   if (isDestroyingOperatorDelete())
2310     ++UsualParams;
2311 
2312   // C++ <=14 [basic.stc.dynamic.deallocation]p2:
2313   //   [...] If class T does not declare such an operator delete but does
2314   //   declare a member deallocation function named operator delete with
2315   //   exactly two parameters, the second of which has type std::size_t (18.1),
2316   //   then this function is a usual deallocation function.
2317   //
2318   // C++17 says a usual deallocation function is one with the signature
2319   //   (void* [, size_t] [, std::align_val_t] [, ...])
2320   // and all such functions are usual deallocation functions. It's not clear
2321   // that allowing varargs functions was intentional.
2322   ASTContext &Context = getASTContext();
2323   if (UsualParams < getNumParams() &&
2324       Context.hasSameUnqualifiedType(getParamDecl(UsualParams)->getType(),
2325                                      Context.getSizeType()))
2326     ++UsualParams;
2327 
2328   if (UsualParams < getNumParams() &&
2329       getParamDecl(UsualParams)->getType()->isAlignValT())
2330     ++UsualParams;
2331 
2332   if (UsualParams != getNumParams())
2333     return false;
2334 
2335   // In C++17 onwards, all potential usual deallocation functions are actual
2336   // usual deallocation functions. Honor this behavior when post-C++14
2337   // deallocation functions are offered as extensions too.
2338   // FIXME(EricWF): Destroying Delete should be a language option. How do we
2339   // handle when destroying delete is used prior to C++17?
2340   if (Context.getLangOpts().CPlusPlus17 ||
2341       Context.getLangOpts().AlignedAllocation ||
2342       isDestroyingOperatorDelete())
2343     return true;
2344 
2345   // This function is a usual deallocation function if there are no
2346   // single-parameter deallocation functions of the same kind.
2347   DeclContext::lookup_result R = getDeclContext()->lookup(getDeclName());
2348   bool Result = true;
2349   for (const auto *D : R) {
2350     if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
2351       if (FD->getNumParams() == 1) {
2352         PreventedBy.push_back(FD);
2353         Result = false;
2354       }
2355     }
2356   }
2357   return Result;
2358 }
2359 
2360 bool CXXMethodDecl::isCopyAssignmentOperator() const {
2361   // C++0x [class.copy]p17:
2362   //  A user-declared copy assignment operator X::operator= is a non-static
2363   //  non-template member function of class X with exactly one parameter of
2364   //  type X, X&, const X&, volatile X& or const volatile X&.
2365   if (/*operator=*/getOverloadedOperator() != OO_Equal ||
2366       /*non-static*/ isStatic() ||
2367       /*non-template*/getPrimaryTemplate() || getDescribedFunctionTemplate() ||
2368       getNumParams() != 1)
2369     return false;
2370 
2371   QualType ParamType = getParamDecl(0)->getType();
2372   if (const auto *Ref = ParamType->getAs<LValueReferenceType>())
2373     ParamType = Ref->getPointeeType();
2374 
2375   ASTContext &Context = getASTContext();
2376   QualType ClassType
2377     = Context.getCanonicalType(Context.getTypeDeclType(getParent()));
2378   return Context.hasSameUnqualifiedType(ClassType, ParamType);
2379 }
2380 
2381 bool CXXMethodDecl::isMoveAssignmentOperator() const {
2382   // C++0x [class.copy]p19:
2383   //  A user-declared move assignment operator X::operator= is a non-static
2384   //  non-template member function of class X with exactly one parameter of type
2385   //  X&&, const X&&, volatile X&&, or const volatile X&&.
2386   if (getOverloadedOperator() != OO_Equal || isStatic() ||
2387       getPrimaryTemplate() || getDescribedFunctionTemplate() ||
2388       getNumParams() != 1)
2389     return false;
2390 
2391   QualType ParamType = getParamDecl(0)->getType();
2392   if (!isa<RValueReferenceType>(ParamType))
2393     return false;
2394   ParamType = ParamType->getPointeeType();
2395 
2396   ASTContext &Context = getASTContext();
2397   QualType ClassType
2398     = Context.getCanonicalType(Context.getTypeDeclType(getParent()));
2399   return Context.hasSameUnqualifiedType(ClassType, ParamType);
2400 }
2401 
2402 void CXXMethodDecl::addOverriddenMethod(const CXXMethodDecl *MD) {
2403   assert(MD->isCanonicalDecl() && "Method is not canonical!");
2404   assert(!MD->getParent()->isDependentContext() &&
2405          "Can't add an overridden method to a class template!");
2406   assert(MD->isVirtual() && "Method is not virtual!");
2407 
2408   getASTContext().addOverriddenMethod(this, MD);
2409 }
2410 
2411 CXXMethodDecl::method_iterator CXXMethodDecl::begin_overridden_methods() const {
2412   if (isa<CXXConstructorDecl>(this)) return nullptr;
2413   return getASTContext().overridden_methods_begin(this);
2414 }
2415 
2416 CXXMethodDecl::method_iterator CXXMethodDecl::end_overridden_methods() const {
2417   if (isa<CXXConstructorDecl>(this)) return nullptr;
2418   return getASTContext().overridden_methods_end(this);
2419 }
2420 
2421 unsigned CXXMethodDecl::size_overridden_methods() const {
2422   if (isa<CXXConstructorDecl>(this)) return 0;
2423   return getASTContext().overridden_methods_size(this);
2424 }
2425 
2426 CXXMethodDecl::overridden_method_range
2427 CXXMethodDecl::overridden_methods() const {
2428   if (isa<CXXConstructorDecl>(this))
2429     return overridden_method_range(nullptr, nullptr);
2430   return getASTContext().overridden_methods(this);
2431 }
2432 
2433 static QualType getThisObjectType(ASTContext &C, const FunctionProtoType *FPT,
2434                                   const CXXRecordDecl *Decl) {
2435   QualType ClassTy = C.getTypeDeclType(Decl);
2436   return C.getQualifiedType(ClassTy, FPT->getMethodQuals());
2437 }
2438 
2439 QualType CXXMethodDecl::getThisType(const FunctionProtoType *FPT,
2440                                     const CXXRecordDecl *Decl) {
2441   ASTContext &C = Decl->getASTContext();
2442   QualType ObjectTy = ::getThisObjectType(C, FPT, Decl);
2443   return C.getPointerType(ObjectTy);
2444 }
2445 
2446 QualType CXXMethodDecl::getThisObjectType(const FunctionProtoType *FPT,
2447                                           const CXXRecordDecl *Decl) {
2448   ASTContext &C = Decl->getASTContext();
2449   return ::getThisObjectType(C, FPT, Decl);
2450 }
2451 
2452 QualType CXXMethodDecl::getThisType() const {
2453   // C++ 9.3.2p1: The type of this in a member function of a class X is X*.
2454   // If the member function is declared const, the type of this is const X*,
2455   // if the member function is declared volatile, the type of this is
2456   // volatile X*, and if the member function is declared const volatile,
2457   // the type of this is const volatile X*.
2458   assert(isInstance() && "No 'this' for static methods!");
2459   return CXXMethodDecl::getThisType(getType()->castAs<FunctionProtoType>(),
2460                                     getParent());
2461 }
2462 
2463 QualType CXXMethodDecl::getThisObjectType() const {
2464   // Ditto getThisType.
2465   assert(isInstance() && "No 'this' for static methods!");
2466   return CXXMethodDecl::getThisObjectType(
2467       getType()->castAs<FunctionProtoType>(), getParent());
2468 }
2469 
2470 bool CXXMethodDecl::hasInlineBody() const {
2471   // If this function is a template instantiation, look at the template from
2472   // which it was instantiated.
2473   const FunctionDecl *CheckFn = getTemplateInstantiationPattern();
2474   if (!CheckFn)
2475     CheckFn = this;
2476 
2477   const FunctionDecl *fn;
2478   return CheckFn->isDefined(fn) && !fn->isOutOfLine() &&
2479          (fn->doesThisDeclarationHaveABody() || fn->willHaveBody());
2480 }
2481 
2482 bool CXXMethodDecl::isLambdaStaticInvoker() const {
2483   const CXXRecordDecl *P = getParent();
2484   return P->isLambda() && getDeclName().isIdentifier() &&
2485          getName() == getLambdaStaticInvokerName();
2486 }
2487 
2488 CXXCtorInitializer::CXXCtorInitializer(ASTContext &Context,
2489                                        TypeSourceInfo *TInfo, bool IsVirtual,
2490                                        SourceLocation L, Expr *Init,
2491                                        SourceLocation R,
2492                                        SourceLocation EllipsisLoc)
2493     : Initializee(TInfo), Init(Init), MemberOrEllipsisLocation(EllipsisLoc),
2494       LParenLoc(L), RParenLoc(R), IsDelegating(false), IsVirtual(IsVirtual),
2495       IsWritten(false), SourceOrder(0) {}
2496 
2497 CXXCtorInitializer::CXXCtorInitializer(ASTContext &Context, FieldDecl *Member,
2498                                        SourceLocation MemberLoc,
2499                                        SourceLocation L, Expr *Init,
2500                                        SourceLocation R)
2501     : Initializee(Member), Init(Init), MemberOrEllipsisLocation(MemberLoc),
2502       LParenLoc(L), RParenLoc(R), IsDelegating(false), IsVirtual(false),
2503       IsWritten(false), SourceOrder(0) {}
2504 
2505 CXXCtorInitializer::CXXCtorInitializer(ASTContext &Context,
2506                                        IndirectFieldDecl *Member,
2507                                        SourceLocation MemberLoc,
2508                                        SourceLocation L, Expr *Init,
2509                                        SourceLocation R)
2510     : Initializee(Member), Init(Init), MemberOrEllipsisLocation(MemberLoc),
2511       LParenLoc(L), RParenLoc(R), IsDelegating(false), IsVirtual(false),
2512       IsWritten(false), SourceOrder(0) {}
2513 
2514 CXXCtorInitializer::CXXCtorInitializer(ASTContext &Context,
2515                                        TypeSourceInfo *TInfo,
2516                                        SourceLocation L, Expr *Init,
2517                                        SourceLocation R)
2518     : Initializee(TInfo), Init(Init), LParenLoc(L), RParenLoc(R),
2519       IsDelegating(true), IsVirtual(false), IsWritten(false), SourceOrder(0) {}
2520 
2521 int64_t CXXCtorInitializer::getID(const ASTContext &Context) const {
2522   return Context.getAllocator()
2523                 .identifyKnownAlignedObject<CXXCtorInitializer>(this);
2524 }
2525 
2526 TypeLoc CXXCtorInitializer::getBaseClassLoc() const {
2527   if (isBaseInitializer())
2528     return Initializee.get<TypeSourceInfo*>()->getTypeLoc();
2529   else
2530     return {};
2531 }
2532 
2533 const Type *CXXCtorInitializer::getBaseClass() const {
2534   if (isBaseInitializer())
2535     return Initializee.get<TypeSourceInfo*>()->getType().getTypePtr();
2536   else
2537     return nullptr;
2538 }
2539 
2540 SourceLocation CXXCtorInitializer::getSourceLocation() const {
2541   if (isInClassMemberInitializer())
2542     return getAnyMember()->getLocation();
2543 
2544   if (isAnyMemberInitializer())
2545     return getMemberLocation();
2546 
2547   if (const auto *TSInfo = Initializee.get<TypeSourceInfo *>())
2548     return TSInfo->getTypeLoc().getLocalSourceRange().getBegin();
2549 
2550   return {};
2551 }
2552 
2553 SourceRange CXXCtorInitializer::getSourceRange() const {
2554   if (isInClassMemberInitializer()) {
2555     FieldDecl *D = getAnyMember();
2556     if (Expr *I = D->getInClassInitializer())
2557       return I->getSourceRange();
2558     return {};
2559   }
2560 
2561   return SourceRange(getSourceLocation(), getRParenLoc());
2562 }
2563 
2564 CXXConstructorDecl::CXXConstructorDecl(
2565     ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2566     const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2567     ExplicitSpecifier ES, bool UsesFPIntrin, bool isInline,
2568     bool isImplicitlyDeclared, ConstexprSpecKind ConstexprKind,
2569     InheritedConstructor Inherited, Expr *TrailingRequiresClause)
2570     : CXXMethodDecl(CXXConstructor, C, RD, StartLoc, NameInfo, T, TInfo,
2571                     SC_None, UsesFPIntrin, isInline, ConstexprKind,
2572                     SourceLocation(), TrailingRequiresClause) {
2573   setNumCtorInitializers(0);
2574   setInheritingConstructor(static_cast<bool>(Inherited));
2575   setImplicit(isImplicitlyDeclared);
2576   CXXConstructorDeclBits.HasTrailingExplicitSpecifier = ES.getExpr() ? 1 : 0;
2577   if (Inherited)
2578     *getTrailingObjects<InheritedConstructor>() = Inherited;
2579   setExplicitSpecifier(ES);
2580 }
2581 
2582 void CXXConstructorDecl::anchor() {}
2583 
2584 CXXConstructorDecl *CXXConstructorDecl::CreateDeserialized(ASTContext &C,
2585                                                            unsigned ID,
2586                                                            uint64_t AllocKind) {
2587   bool hasTrailingExplicit = static_cast<bool>(AllocKind & TAKHasTailExplicit);
2588   bool isInheritingConstructor =
2589       static_cast<bool>(AllocKind & TAKInheritsConstructor);
2590   unsigned Extra =
2591       additionalSizeToAlloc<InheritedConstructor, ExplicitSpecifier>(
2592           isInheritingConstructor, hasTrailingExplicit);
2593   auto *Result = new (C, ID, Extra) CXXConstructorDecl(
2594       C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(), nullptr,
2595       ExplicitSpecifier(), false, false, false, ConstexprSpecKind::Unspecified,
2596       InheritedConstructor(), nullptr);
2597   Result->setInheritingConstructor(isInheritingConstructor);
2598   Result->CXXConstructorDeclBits.HasTrailingExplicitSpecifier =
2599       hasTrailingExplicit;
2600   Result->setExplicitSpecifier(ExplicitSpecifier());
2601   return Result;
2602 }
2603 
2604 CXXConstructorDecl *CXXConstructorDecl::Create(
2605     ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2606     const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2607     ExplicitSpecifier ES, bool UsesFPIntrin, bool isInline,
2608     bool isImplicitlyDeclared, ConstexprSpecKind ConstexprKind,
2609     InheritedConstructor Inherited, Expr *TrailingRequiresClause) {
2610   assert(NameInfo.getName().getNameKind()
2611          == DeclarationName::CXXConstructorName &&
2612          "Name must refer to a constructor");
2613   unsigned Extra =
2614       additionalSizeToAlloc<InheritedConstructor, ExplicitSpecifier>(
2615           Inherited ? 1 : 0, ES.getExpr() ? 1 : 0);
2616   return new (C, RD, Extra) CXXConstructorDecl(
2617       C, RD, StartLoc, NameInfo, T, TInfo, ES, UsesFPIntrin, isInline,
2618       isImplicitlyDeclared, ConstexprKind, Inherited, TrailingRequiresClause);
2619 }
2620 
2621 CXXConstructorDecl::init_const_iterator CXXConstructorDecl::init_begin() const {
2622   return CtorInitializers.get(getASTContext().getExternalSource());
2623 }
2624 
2625 CXXConstructorDecl *CXXConstructorDecl::getTargetConstructor() const {
2626   assert(isDelegatingConstructor() && "Not a delegating constructor!");
2627   Expr *E = (*init_begin())->getInit()->IgnoreImplicit();
2628   if (const auto *Construct = dyn_cast<CXXConstructExpr>(E))
2629     return Construct->getConstructor();
2630 
2631   return nullptr;
2632 }
2633 
2634 bool CXXConstructorDecl::isDefaultConstructor() const {
2635   // C++ [class.default.ctor]p1:
2636   //   A default constructor for a class X is a constructor of class X for
2637   //   which each parameter that is not a function parameter pack has a default
2638   //   argument (including the case of a constructor with no parameters)
2639   return getMinRequiredArguments() == 0;
2640 }
2641 
2642 bool
2643 CXXConstructorDecl::isCopyConstructor(unsigned &TypeQuals) const {
2644   return isCopyOrMoveConstructor(TypeQuals) &&
2645          getParamDecl(0)->getType()->isLValueReferenceType();
2646 }
2647 
2648 bool CXXConstructorDecl::isMoveConstructor(unsigned &TypeQuals) const {
2649   return isCopyOrMoveConstructor(TypeQuals) &&
2650          getParamDecl(0)->getType()->isRValueReferenceType();
2651 }
2652 
2653 /// Determine whether this is a copy or move constructor.
2654 bool CXXConstructorDecl::isCopyOrMoveConstructor(unsigned &TypeQuals) const {
2655   // C++ [class.copy]p2:
2656   //   A non-template constructor for class X is a copy constructor
2657   //   if its first parameter is of type X&, const X&, volatile X& or
2658   //   const volatile X&, and either there are no other parameters
2659   //   or else all other parameters have default arguments (8.3.6).
2660   // C++0x [class.copy]p3:
2661   //   A non-template constructor for class X is a move constructor if its
2662   //   first parameter is of type X&&, const X&&, volatile X&&, or
2663   //   const volatile X&&, and either there are no other parameters or else
2664   //   all other parameters have default arguments.
2665   if (!hasOneParamOrDefaultArgs() || getPrimaryTemplate() != nullptr ||
2666       getDescribedFunctionTemplate() != nullptr)
2667     return false;
2668 
2669   const ParmVarDecl *Param = getParamDecl(0);
2670 
2671   // Do we have a reference type?
2672   const auto *ParamRefType = Param->getType()->getAs<ReferenceType>();
2673   if (!ParamRefType)
2674     return false;
2675 
2676   // Is it a reference to our class type?
2677   ASTContext &Context = getASTContext();
2678 
2679   CanQualType PointeeType
2680     = Context.getCanonicalType(ParamRefType->getPointeeType());
2681   CanQualType ClassTy
2682     = Context.getCanonicalType(Context.getTagDeclType(getParent()));
2683   if (PointeeType.getUnqualifiedType() != ClassTy)
2684     return false;
2685 
2686   // FIXME: other qualifiers?
2687 
2688   // We have a copy or move constructor.
2689   TypeQuals = PointeeType.getCVRQualifiers();
2690   return true;
2691 }
2692 
2693 bool CXXConstructorDecl::isConvertingConstructor(bool AllowExplicit) const {
2694   // C++ [class.conv.ctor]p1:
2695   //   A constructor declared without the function-specifier explicit
2696   //   that can be called with a single parameter specifies a
2697   //   conversion from the type of its first parameter to the type of
2698   //   its class. Such a constructor is called a converting
2699   //   constructor.
2700   if (isExplicit() && !AllowExplicit)
2701     return false;
2702 
2703   // FIXME: This has nothing to do with the definition of converting
2704   // constructor, but is convenient for how we use this function in overload
2705   // resolution.
2706   return getNumParams() == 0
2707              ? getType()->castAs<FunctionProtoType>()->isVariadic()
2708              : getMinRequiredArguments() <= 1;
2709 }
2710 
2711 bool CXXConstructorDecl::isSpecializationCopyingObject() const {
2712   if (!hasOneParamOrDefaultArgs() || getDescribedFunctionTemplate() != nullptr)
2713     return false;
2714 
2715   const ParmVarDecl *Param = getParamDecl(0);
2716 
2717   ASTContext &Context = getASTContext();
2718   CanQualType ParamType = Context.getCanonicalType(Param->getType());
2719 
2720   // Is it the same as our class type?
2721   CanQualType ClassTy
2722     = Context.getCanonicalType(Context.getTagDeclType(getParent()));
2723   if (ParamType.getUnqualifiedType() != ClassTy)
2724     return false;
2725 
2726   return true;
2727 }
2728 
2729 void CXXDestructorDecl::anchor() {}
2730 
2731 CXXDestructorDecl *
2732 CXXDestructorDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2733   return new (C, ID) CXXDestructorDecl(
2734       C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(), nullptr,
2735       false, false, false, ConstexprSpecKind::Unspecified, nullptr);
2736 }
2737 
2738 CXXDestructorDecl *CXXDestructorDecl::Create(
2739     ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2740     const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2741     bool UsesFPIntrin, bool isInline, bool isImplicitlyDeclared,
2742     ConstexprSpecKind ConstexprKind, Expr *TrailingRequiresClause) {
2743   assert(NameInfo.getName().getNameKind()
2744          == DeclarationName::CXXDestructorName &&
2745          "Name must refer to a destructor");
2746   return new (C, RD) CXXDestructorDecl(
2747       C, RD, StartLoc, NameInfo, T, TInfo, UsesFPIntrin, isInline,
2748       isImplicitlyDeclared, ConstexprKind, TrailingRequiresClause);
2749 }
2750 
2751 void CXXDestructorDecl::setOperatorDelete(FunctionDecl *OD, Expr *ThisArg) {
2752   auto *First = cast<CXXDestructorDecl>(getFirstDecl());
2753   if (OD && !First->OperatorDelete) {
2754     First->OperatorDelete = OD;
2755     First->OperatorDeleteThisArg = ThisArg;
2756     if (auto *L = getASTMutationListener())
2757       L->ResolvedOperatorDelete(First, OD, ThisArg);
2758   }
2759 }
2760 
2761 void CXXConversionDecl::anchor() {}
2762 
2763 CXXConversionDecl *
2764 CXXConversionDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2765   return new (C, ID) CXXConversionDecl(
2766       C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(), nullptr,
2767       false, false, ExplicitSpecifier(), ConstexprSpecKind::Unspecified,
2768       SourceLocation(), nullptr);
2769 }
2770 
2771 CXXConversionDecl *CXXConversionDecl::Create(
2772     ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2773     const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2774     bool UsesFPIntrin, bool isInline, ExplicitSpecifier ES,
2775     ConstexprSpecKind ConstexprKind, SourceLocation EndLocation,
2776     Expr *TrailingRequiresClause) {
2777   assert(NameInfo.getName().getNameKind()
2778          == DeclarationName::CXXConversionFunctionName &&
2779          "Name must refer to a conversion function");
2780   return new (C, RD) CXXConversionDecl(
2781       C, RD, StartLoc, NameInfo, T, TInfo, UsesFPIntrin, isInline, ES,
2782       ConstexprKind, EndLocation, TrailingRequiresClause);
2783 }
2784 
2785 bool CXXConversionDecl::isLambdaToBlockPointerConversion() const {
2786   return isImplicit() && getParent()->isLambda() &&
2787          getConversionType()->isBlockPointerType();
2788 }
2789 
2790 LinkageSpecDecl::LinkageSpecDecl(DeclContext *DC, SourceLocation ExternLoc,
2791                                  SourceLocation LangLoc, LanguageIDs lang,
2792                                  bool HasBraces)
2793     : Decl(LinkageSpec, DC, LangLoc), DeclContext(LinkageSpec),
2794       ExternLoc(ExternLoc), RBraceLoc(SourceLocation()) {
2795   setLanguage(lang);
2796   LinkageSpecDeclBits.HasBraces = HasBraces;
2797 }
2798 
2799 void LinkageSpecDecl::anchor() {}
2800 
2801 LinkageSpecDecl *LinkageSpecDecl::Create(ASTContext &C,
2802                                          DeclContext *DC,
2803                                          SourceLocation ExternLoc,
2804                                          SourceLocation LangLoc,
2805                                          LanguageIDs Lang,
2806                                          bool HasBraces) {
2807   return new (C, DC) LinkageSpecDecl(DC, ExternLoc, LangLoc, Lang, HasBraces);
2808 }
2809 
2810 LinkageSpecDecl *LinkageSpecDecl::CreateDeserialized(ASTContext &C,
2811                                                      unsigned ID) {
2812   return new (C, ID) LinkageSpecDecl(nullptr, SourceLocation(),
2813                                      SourceLocation(), lang_c, false);
2814 }
2815 
2816 void UsingDirectiveDecl::anchor() {}
2817 
2818 UsingDirectiveDecl *UsingDirectiveDecl::Create(ASTContext &C, DeclContext *DC,
2819                                                SourceLocation L,
2820                                                SourceLocation NamespaceLoc,
2821                                            NestedNameSpecifierLoc QualifierLoc,
2822                                                SourceLocation IdentLoc,
2823                                                NamedDecl *Used,
2824                                                DeclContext *CommonAncestor) {
2825   if (auto *NS = dyn_cast_or_null<NamespaceDecl>(Used))
2826     Used = NS->getOriginalNamespace();
2827   return new (C, DC) UsingDirectiveDecl(DC, L, NamespaceLoc, QualifierLoc,
2828                                         IdentLoc, Used, CommonAncestor);
2829 }
2830 
2831 UsingDirectiveDecl *UsingDirectiveDecl::CreateDeserialized(ASTContext &C,
2832                                                            unsigned ID) {
2833   return new (C, ID) UsingDirectiveDecl(nullptr, SourceLocation(),
2834                                         SourceLocation(),
2835                                         NestedNameSpecifierLoc(),
2836                                         SourceLocation(), nullptr, nullptr);
2837 }
2838 
2839 NamespaceDecl *UsingDirectiveDecl::getNominatedNamespace() {
2840   if (auto *NA = dyn_cast_or_null<NamespaceAliasDecl>(NominatedNamespace))
2841     return NA->getNamespace();
2842   return cast_or_null<NamespaceDecl>(NominatedNamespace);
2843 }
2844 
2845 NamespaceDecl::NamespaceDecl(ASTContext &C, DeclContext *DC, bool Inline,
2846                              SourceLocation StartLoc, SourceLocation IdLoc,
2847                              IdentifierInfo *Id, NamespaceDecl *PrevDecl)
2848     : NamedDecl(Namespace, DC, IdLoc, Id), DeclContext(Namespace),
2849       redeclarable_base(C), LocStart(StartLoc),
2850       AnonOrFirstNamespaceAndInline(nullptr, Inline) {
2851   setPreviousDecl(PrevDecl);
2852 
2853   if (PrevDecl)
2854     AnonOrFirstNamespaceAndInline.setPointer(PrevDecl->getOriginalNamespace());
2855 }
2856 
2857 NamespaceDecl *NamespaceDecl::Create(ASTContext &C, DeclContext *DC,
2858                                      bool Inline, SourceLocation StartLoc,
2859                                      SourceLocation IdLoc, IdentifierInfo *Id,
2860                                      NamespaceDecl *PrevDecl) {
2861   return new (C, DC) NamespaceDecl(C, DC, Inline, StartLoc, IdLoc, Id,
2862                                    PrevDecl);
2863 }
2864 
2865 NamespaceDecl *NamespaceDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2866   return new (C, ID) NamespaceDecl(C, nullptr, false, SourceLocation(),
2867                                    SourceLocation(), nullptr, nullptr);
2868 }
2869 
2870 NamespaceDecl *NamespaceDecl::getOriginalNamespace() {
2871   if (isFirstDecl())
2872     return this;
2873 
2874   return AnonOrFirstNamespaceAndInline.getPointer();
2875 }
2876 
2877 const NamespaceDecl *NamespaceDecl::getOriginalNamespace() const {
2878   if (isFirstDecl())
2879     return this;
2880 
2881   return AnonOrFirstNamespaceAndInline.getPointer();
2882 }
2883 
2884 bool NamespaceDecl::isOriginalNamespace() const { return isFirstDecl(); }
2885 
2886 NamespaceDecl *NamespaceDecl::getNextRedeclarationImpl() {
2887   return getNextRedeclaration();
2888 }
2889 
2890 NamespaceDecl *NamespaceDecl::getPreviousDeclImpl() {
2891   return getPreviousDecl();
2892 }
2893 
2894 NamespaceDecl *NamespaceDecl::getMostRecentDeclImpl() {
2895   return getMostRecentDecl();
2896 }
2897 
2898 void NamespaceAliasDecl::anchor() {}
2899 
2900 NamespaceAliasDecl *NamespaceAliasDecl::getNextRedeclarationImpl() {
2901   return getNextRedeclaration();
2902 }
2903 
2904 NamespaceAliasDecl *NamespaceAliasDecl::getPreviousDeclImpl() {
2905   return getPreviousDecl();
2906 }
2907 
2908 NamespaceAliasDecl *NamespaceAliasDecl::getMostRecentDeclImpl() {
2909   return getMostRecentDecl();
2910 }
2911 
2912 NamespaceAliasDecl *NamespaceAliasDecl::Create(ASTContext &C, DeclContext *DC,
2913                                                SourceLocation UsingLoc,
2914                                                SourceLocation AliasLoc,
2915                                                IdentifierInfo *Alias,
2916                                            NestedNameSpecifierLoc QualifierLoc,
2917                                                SourceLocation IdentLoc,
2918                                                NamedDecl *Namespace) {
2919   // FIXME: Preserve the aliased namespace as written.
2920   if (auto *NS = dyn_cast_or_null<NamespaceDecl>(Namespace))
2921     Namespace = NS->getOriginalNamespace();
2922   return new (C, DC) NamespaceAliasDecl(C, DC, UsingLoc, AliasLoc, Alias,
2923                                         QualifierLoc, IdentLoc, Namespace);
2924 }
2925 
2926 NamespaceAliasDecl *
2927 NamespaceAliasDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2928   return new (C, ID) NamespaceAliasDecl(C, nullptr, SourceLocation(),
2929                                         SourceLocation(), nullptr,
2930                                         NestedNameSpecifierLoc(),
2931                                         SourceLocation(), nullptr);
2932 }
2933 
2934 void LifetimeExtendedTemporaryDecl::anchor() {}
2935 
2936 /// Retrieve the storage duration for the materialized temporary.
2937 StorageDuration LifetimeExtendedTemporaryDecl::getStorageDuration() const {
2938   const ValueDecl *ExtendingDecl = getExtendingDecl();
2939   if (!ExtendingDecl)
2940     return SD_FullExpression;
2941   // FIXME: This is not necessarily correct for a temporary materialized
2942   // within a default initializer.
2943   if (isa<FieldDecl>(ExtendingDecl))
2944     return SD_Automatic;
2945   // FIXME: This only works because storage class specifiers are not allowed
2946   // on decomposition declarations.
2947   if (isa<BindingDecl>(ExtendingDecl))
2948     return ExtendingDecl->getDeclContext()->isFunctionOrMethod() ? SD_Automatic
2949                                                                  : SD_Static;
2950   return cast<VarDecl>(ExtendingDecl)->getStorageDuration();
2951 }
2952 
2953 APValue *LifetimeExtendedTemporaryDecl::getOrCreateValue(bool MayCreate) const {
2954   assert(getStorageDuration() == SD_Static &&
2955          "don't need to cache the computed value for this temporary");
2956   if (MayCreate && !Value) {
2957     Value = (new (getASTContext()) APValue);
2958     getASTContext().addDestruction(Value);
2959   }
2960   assert(Value && "may not be null");
2961   return Value;
2962 }
2963 
2964 void UsingShadowDecl::anchor() {}
2965 
2966 UsingShadowDecl::UsingShadowDecl(Kind K, ASTContext &C, DeclContext *DC,
2967                                  SourceLocation Loc, DeclarationName Name,
2968                                  BaseUsingDecl *Introducer, NamedDecl *Target)
2969     : NamedDecl(K, DC, Loc, Name), redeclarable_base(C),
2970       UsingOrNextShadow(Introducer) {
2971   if (Target)
2972     setTargetDecl(Target);
2973   setImplicit();
2974 }
2975 
2976 UsingShadowDecl::UsingShadowDecl(Kind K, ASTContext &C, EmptyShell Empty)
2977     : NamedDecl(K, nullptr, SourceLocation(), DeclarationName()),
2978       redeclarable_base(C) {}
2979 
2980 UsingShadowDecl *
2981 UsingShadowDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2982   return new (C, ID) UsingShadowDecl(UsingShadow, C, EmptyShell());
2983 }
2984 
2985 BaseUsingDecl *UsingShadowDecl::getIntroducer() const {
2986   const UsingShadowDecl *Shadow = this;
2987   while (const auto *NextShadow =
2988              dyn_cast<UsingShadowDecl>(Shadow->UsingOrNextShadow))
2989     Shadow = NextShadow;
2990   return cast<BaseUsingDecl>(Shadow->UsingOrNextShadow);
2991 }
2992 
2993 void ConstructorUsingShadowDecl::anchor() {}
2994 
2995 ConstructorUsingShadowDecl *
2996 ConstructorUsingShadowDecl::Create(ASTContext &C, DeclContext *DC,
2997                                    SourceLocation Loc, UsingDecl *Using,
2998                                    NamedDecl *Target, bool IsVirtual) {
2999   return new (C, DC) ConstructorUsingShadowDecl(C, DC, Loc, Using, Target,
3000                                                 IsVirtual);
3001 }
3002 
3003 ConstructorUsingShadowDecl *
3004 ConstructorUsingShadowDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3005   return new (C, ID) ConstructorUsingShadowDecl(C, EmptyShell());
3006 }
3007 
3008 CXXRecordDecl *ConstructorUsingShadowDecl::getNominatedBaseClass() const {
3009   return getIntroducer()->getQualifier()->getAsRecordDecl();
3010 }
3011 
3012 void BaseUsingDecl::anchor() {}
3013 
3014 void BaseUsingDecl::addShadowDecl(UsingShadowDecl *S) {
3015   assert(!llvm::is_contained(shadows(), S) && "declaration already in set");
3016   assert(S->getIntroducer() == this);
3017 
3018   if (FirstUsingShadow.getPointer())
3019     S->UsingOrNextShadow = FirstUsingShadow.getPointer();
3020   FirstUsingShadow.setPointer(S);
3021 }
3022 
3023 void BaseUsingDecl::removeShadowDecl(UsingShadowDecl *S) {
3024   assert(llvm::is_contained(shadows(), S) && "declaration not in set");
3025   assert(S->getIntroducer() == this);
3026 
3027   // Remove S from the shadow decl chain. This is O(n) but hopefully rare.
3028 
3029   if (FirstUsingShadow.getPointer() == S) {
3030     FirstUsingShadow.setPointer(
3031       dyn_cast<UsingShadowDecl>(S->UsingOrNextShadow));
3032     S->UsingOrNextShadow = this;
3033     return;
3034   }
3035 
3036   UsingShadowDecl *Prev = FirstUsingShadow.getPointer();
3037   while (Prev->UsingOrNextShadow != S)
3038     Prev = cast<UsingShadowDecl>(Prev->UsingOrNextShadow);
3039   Prev->UsingOrNextShadow = S->UsingOrNextShadow;
3040   S->UsingOrNextShadow = this;
3041 }
3042 
3043 void UsingDecl::anchor() {}
3044 
3045 UsingDecl *UsingDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation UL,
3046                              NestedNameSpecifierLoc QualifierLoc,
3047                              const DeclarationNameInfo &NameInfo,
3048                              bool HasTypename) {
3049   return new (C, DC) UsingDecl(DC, UL, QualifierLoc, NameInfo, HasTypename);
3050 }
3051 
3052 UsingDecl *UsingDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3053   return new (C, ID) UsingDecl(nullptr, SourceLocation(),
3054                                NestedNameSpecifierLoc(), DeclarationNameInfo(),
3055                                false);
3056 }
3057 
3058 SourceRange UsingDecl::getSourceRange() const {
3059   SourceLocation Begin = isAccessDeclaration()
3060     ? getQualifierLoc().getBeginLoc() : UsingLocation;
3061   return SourceRange(Begin, getNameInfo().getEndLoc());
3062 }
3063 
3064 void UsingEnumDecl::anchor() {}
3065 
3066 UsingEnumDecl *UsingEnumDecl::Create(ASTContext &C, DeclContext *DC,
3067                                      SourceLocation UL, SourceLocation EL,
3068                                      SourceLocation NL, EnumDecl *Enum) {
3069   return new (C, DC) UsingEnumDecl(DC, Enum->getDeclName(), UL, EL, NL, Enum);
3070 }
3071 
3072 UsingEnumDecl *UsingEnumDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3073   return new (C, ID) UsingEnumDecl(nullptr, DeclarationName(), SourceLocation(),
3074                                    SourceLocation(), SourceLocation(), nullptr);
3075 }
3076 
3077 SourceRange UsingEnumDecl::getSourceRange() const {
3078   return SourceRange(EnumLocation, getLocation());
3079 }
3080 
3081 void UsingPackDecl::anchor() {}
3082 
3083 UsingPackDecl *UsingPackDecl::Create(ASTContext &C, DeclContext *DC,
3084                                      NamedDecl *InstantiatedFrom,
3085                                      ArrayRef<NamedDecl *> UsingDecls) {
3086   size_t Extra = additionalSizeToAlloc<NamedDecl *>(UsingDecls.size());
3087   return new (C, DC, Extra) UsingPackDecl(DC, InstantiatedFrom, UsingDecls);
3088 }
3089 
3090 UsingPackDecl *UsingPackDecl::CreateDeserialized(ASTContext &C, unsigned ID,
3091                                                  unsigned NumExpansions) {
3092   size_t Extra = additionalSizeToAlloc<NamedDecl *>(NumExpansions);
3093   auto *Result = new (C, ID, Extra) UsingPackDecl(nullptr, nullptr, None);
3094   Result->NumExpansions = NumExpansions;
3095   auto *Trail = Result->getTrailingObjects<NamedDecl *>();
3096   for (unsigned I = 0; I != NumExpansions; ++I)
3097     new (Trail + I) NamedDecl*(nullptr);
3098   return Result;
3099 }
3100 
3101 void UnresolvedUsingValueDecl::anchor() {}
3102 
3103 UnresolvedUsingValueDecl *
3104 UnresolvedUsingValueDecl::Create(ASTContext &C, DeclContext *DC,
3105                                  SourceLocation UsingLoc,
3106                                  NestedNameSpecifierLoc QualifierLoc,
3107                                  const DeclarationNameInfo &NameInfo,
3108                                  SourceLocation EllipsisLoc) {
3109   return new (C, DC) UnresolvedUsingValueDecl(DC, C.DependentTy, UsingLoc,
3110                                               QualifierLoc, NameInfo,
3111                                               EllipsisLoc);
3112 }
3113 
3114 UnresolvedUsingValueDecl *
3115 UnresolvedUsingValueDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3116   return new (C, ID) UnresolvedUsingValueDecl(nullptr, QualType(),
3117                                               SourceLocation(),
3118                                               NestedNameSpecifierLoc(),
3119                                               DeclarationNameInfo(),
3120                                               SourceLocation());
3121 }
3122 
3123 SourceRange UnresolvedUsingValueDecl::getSourceRange() const {
3124   SourceLocation Begin = isAccessDeclaration()
3125     ? getQualifierLoc().getBeginLoc() : UsingLocation;
3126   return SourceRange(Begin, getNameInfo().getEndLoc());
3127 }
3128 
3129 void UnresolvedUsingTypenameDecl::anchor() {}
3130 
3131 UnresolvedUsingTypenameDecl *
3132 UnresolvedUsingTypenameDecl::Create(ASTContext &C, DeclContext *DC,
3133                                     SourceLocation UsingLoc,
3134                                     SourceLocation TypenameLoc,
3135                                     NestedNameSpecifierLoc QualifierLoc,
3136                                     SourceLocation TargetNameLoc,
3137                                     DeclarationName TargetName,
3138                                     SourceLocation EllipsisLoc) {
3139   return new (C, DC) UnresolvedUsingTypenameDecl(
3140       DC, UsingLoc, TypenameLoc, QualifierLoc, TargetNameLoc,
3141       TargetName.getAsIdentifierInfo(), EllipsisLoc);
3142 }
3143 
3144 UnresolvedUsingTypenameDecl *
3145 UnresolvedUsingTypenameDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3146   return new (C, ID) UnresolvedUsingTypenameDecl(
3147       nullptr, SourceLocation(), SourceLocation(), NestedNameSpecifierLoc(),
3148       SourceLocation(), nullptr, SourceLocation());
3149 }
3150 
3151 UnresolvedUsingIfExistsDecl *
3152 UnresolvedUsingIfExistsDecl::Create(ASTContext &Ctx, DeclContext *DC,
3153                                     SourceLocation Loc, DeclarationName Name) {
3154   return new (Ctx, DC) UnresolvedUsingIfExistsDecl(DC, Loc, Name);
3155 }
3156 
3157 UnresolvedUsingIfExistsDecl *
3158 UnresolvedUsingIfExistsDecl::CreateDeserialized(ASTContext &Ctx, unsigned ID) {
3159   return new (Ctx, ID)
3160       UnresolvedUsingIfExistsDecl(nullptr, SourceLocation(), DeclarationName());
3161 }
3162 
3163 UnresolvedUsingIfExistsDecl::UnresolvedUsingIfExistsDecl(DeclContext *DC,
3164                                                          SourceLocation Loc,
3165                                                          DeclarationName Name)
3166     : NamedDecl(Decl::UnresolvedUsingIfExists, DC, Loc, Name) {}
3167 
3168 void UnresolvedUsingIfExistsDecl::anchor() {}
3169 
3170 void StaticAssertDecl::anchor() {}
3171 
3172 StaticAssertDecl *StaticAssertDecl::Create(ASTContext &C, DeclContext *DC,
3173                                            SourceLocation StaticAssertLoc,
3174                                            Expr *AssertExpr,
3175                                            StringLiteral *Message,
3176                                            SourceLocation RParenLoc,
3177                                            bool Failed) {
3178   return new (C, DC) StaticAssertDecl(DC, StaticAssertLoc, AssertExpr, Message,
3179                                       RParenLoc, Failed);
3180 }
3181 
3182 StaticAssertDecl *StaticAssertDecl::CreateDeserialized(ASTContext &C,
3183                                                        unsigned ID) {
3184   return new (C, ID) StaticAssertDecl(nullptr, SourceLocation(), nullptr,
3185                                       nullptr, SourceLocation(), false);
3186 }
3187 
3188 void BindingDecl::anchor() {}
3189 
3190 BindingDecl *BindingDecl::Create(ASTContext &C, DeclContext *DC,
3191                                  SourceLocation IdLoc, IdentifierInfo *Id) {
3192   return new (C, DC) BindingDecl(DC, IdLoc, Id);
3193 }
3194 
3195 BindingDecl *BindingDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3196   return new (C, ID) BindingDecl(nullptr, SourceLocation(), nullptr);
3197 }
3198 
3199 VarDecl *BindingDecl::getHoldingVar() const {
3200   Expr *B = getBinding();
3201   if (!B)
3202     return nullptr;
3203   auto *DRE = dyn_cast<DeclRefExpr>(B->IgnoreImplicit());
3204   if (!DRE)
3205     return nullptr;
3206 
3207   auto *VD = cast<VarDecl>(DRE->getDecl());
3208   assert(VD->isImplicit() && "holding var for binding decl not implicit");
3209   return VD;
3210 }
3211 
3212 void DecompositionDecl::anchor() {}
3213 
3214 DecompositionDecl *DecompositionDecl::Create(ASTContext &C, DeclContext *DC,
3215                                              SourceLocation StartLoc,
3216                                              SourceLocation LSquareLoc,
3217                                              QualType T, TypeSourceInfo *TInfo,
3218                                              StorageClass SC,
3219                                              ArrayRef<BindingDecl *> Bindings) {
3220   size_t Extra = additionalSizeToAlloc<BindingDecl *>(Bindings.size());
3221   return new (C, DC, Extra)
3222       DecompositionDecl(C, DC, StartLoc, LSquareLoc, T, TInfo, SC, Bindings);
3223 }
3224 
3225 DecompositionDecl *DecompositionDecl::CreateDeserialized(ASTContext &C,
3226                                                          unsigned ID,
3227                                                          unsigned NumBindings) {
3228   size_t Extra = additionalSizeToAlloc<BindingDecl *>(NumBindings);
3229   auto *Result = new (C, ID, Extra)
3230       DecompositionDecl(C, nullptr, SourceLocation(), SourceLocation(),
3231                         QualType(), nullptr, StorageClass(), None);
3232   // Set up and clean out the bindings array.
3233   Result->NumBindings = NumBindings;
3234   auto *Trail = Result->getTrailingObjects<BindingDecl *>();
3235   for (unsigned I = 0; I != NumBindings; ++I)
3236     new (Trail + I) BindingDecl*(nullptr);
3237   return Result;
3238 }
3239 
3240 void DecompositionDecl::printName(llvm::raw_ostream &os) const {
3241   os << '[';
3242   bool Comma = false;
3243   for (const auto *B : bindings()) {
3244     if (Comma)
3245       os << ", ";
3246     B->printName(os);
3247     Comma = true;
3248   }
3249   os << ']';
3250 }
3251 
3252 void MSPropertyDecl::anchor() {}
3253 
3254 MSPropertyDecl *MSPropertyDecl::Create(ASTContext &C, DeclContext *DC,
3255                                        SourceLocation L, DeclarationName N,
3256                                        QualType T, TypeSourceInfo *TInfo,
3257                                        SourceLocation StartL,
3258                                        IdentifierInfo *Getter,
3259                                        IdentifierInfo *Setter) {
3260   return new (C, DC) MSPropertyDecl(DC, L, N, T, TInfo, StartL, Getter, Setter);
3261 }
3262 
3263 MSPropertyDecl *MSPropertyDecl::CreateDeserialized(ASTContext &C,
3264                                                    unsigned ID) {
3265   return new (C, ID) MSPropertyDecl(nullptr, SourceLocation(),
3266                                     DeclarationName(), QualType(), nullptr,
3267                                     SourceLocation(), nullptr, nullptr);
3268 }
3269 
3270 void MSGuidDecl::anchor() {}
3271 
3272 MSGuidDecl::MSGuidDecl(DeclContext *DC, QualType T, Parts P)
3273     : ValueDecl(Decl::MSGuid, DC, SourceLocation(), DeclarationName(), T),
3274       PartVal(P) {}
3275 
3276 MSGuidDecl *MSGuidDecl::Create(const ASTContext &C, QualType T, Parts P) {
3277   DeclContext *DC = C.getTranslationUnitDecl();
3278   return new (C, DC) MSGuidDecl(DC, T, P);
3279 }
3280 
3281 MSGuidDecl *MSGuidDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3282   return new (C, ID) MSGuidDecl(nullptr, QualType(), Parts());
3283 }
3284 
3285 void MSGuidDecl::printName(llvm::raw_ostream &OS) const {
3286   OS << llvm::format("GUID{%08" PRIx32 "-%04" PRIx16 "-%04" PRIx16 "-",
3287                      PartVal.Part1, PartVal.Part2, PartVal.Part3);
3288   unsigned I = 0;
3289   for (uint8_t Byte : PartVal.Part4And5) {
3290     OS << llvm::format("%02" PRIx8, Byte);
3291     if (++I == 2)
3292       OS << '-';
3293   }
3294   OS << '}';
3295 }
3296 
3297 /// Determine if T is a valid 'struct _GUID' of the shape that we expect.
3298 static bool isValidStructGUID(ASTContext &Ctx, QualType T) {
3299   // FIXME: We only need to check this once, not once each time we compute a
3300   // GUID APValue.
3301   using MatcherRef = llvm::function_ref<bool(QualType)>;
3302 
3303   auto IsInt = [&Ctx](unsigned N) {
3304     return [&Ctx, N](QualType T) {
3305       return T->isUnsignedIntegerOrEnumerationType() &&
3306              Ctx.getIntWidth(T) == N;
3307     };
3308   };
3309 
3310   auto IsArray = [&Ctx](MatcherRef Elem, unsigned N) {
3311     return [&Ctx, Elem, N](QualType T) {
3312       const ConstantArrayType *CAT = Ctx.getAsConstantArrayType(T);
3313       return CAT && CAT->getSize() == N && Elem(CAT->getElementType());
3314     };
3315   };
3316 
3317   auto IsStruct = [](std::initializer_list<MatcherRef> Fields) {
3318     return [Fields](QualType T) {
3319       const RecordDecl *RD = T->getAsRecordDecl();
3320       if (!RD || RD->isUnion())
3321         return false;
3322       RD = RD->getDefinition();
3323       if (!RD)
3324         return false;
3325       if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
3326         if (CXXRD->getNumBases())
3327           return false;
3328       auto MatcherIt = Fields.begin();
3329       for (const FieldDecl *FD : RD->fields()) {
3330         if (FD->isUnnamedBitfield()) continue;
3331         if (FD->isBitField() || MatcherIt == Fields.end() ||
3332             !(*MatcherIt)(FD->getType()))
3333           return false;
3334         ++MatcherIt;
3335       }
3336       return MatcherIt == Fields.end();
3337     };
3338   };
3339 
3340   // We expect an {i32, i16, i16, [8 x i8]}.
3341   return IsStruct({IsInt(32), IsInt(16), IsInt(16), IsArray(IsInt(8), 8)})(T);
3342 }
3343 
3344 APValue &MSGuidDecl::getAsAPValue() const {
3345   if (APVal.isAbsent() && isValidStructGUID(getASTContext(), getType())) {
3346     using llvm::APInt;
3347     using llvm::APSInt;
3348     APVal = APValue(APValue::UninitStruct(), 0, 4);
3349     APVal.getStructField(0) = APValue(APSInt(APInt(32, PartVal.Part1), true));
3350     APVal.getStructField(1) = APValue(APSInt(APInt(16, PartVal.Part2), true));
3351     APVal.getStructField(2) = APValue(APSInt(APInt(16, PartVal.Part3), true));
3352     APValue &Arr = APVal.getStructField(3) =
3353         APValue(APValue::UninitArray(), 8, 8);
3354     for (unsigned I = 0; I != 8; ++I) {
3355       Arr.getArrayInitializedElt(I) =
3356           APValue(APSInt(APInt(8, PartVal.Part4And5[I]), true));
3357     }
3358     // Register this APValue to be destroyed if necessary. (Note that the
3359     // MSGuidDecl destructor is never run.)
3360     getASTContext().addDestruction(&APVal);
3361   }
3362 
3363   return APVal;
3364 }
3365 
3366 static const char *getAccessName(AccessSpecifier AS) {
3367   switch (AS) {
3368     case AS_none:
3369       llvm_unreachable("Invalid access specifier!");
3370     case AS_public:
3371       return "public";
3372     case AS_private:
3373       return "private";
3374     case AS_protected:
3375       return "protected";
3376   }
3377   llvm_unreachable("Invalid access specifier!");
3378 }
3379 
3380 const StreamingDiagnostic &clang::operator<<(const StreamingDiagnostic &DB,
3381                                              AccessSpecifier AS) {
3382   return DB << getAccessName(AS);
3383 }
3384