xref: /freebsd/contrib/llvm-project/clang/lib/AST/DeclCXX.cpp (revision e32fecd0c2c3ee37c47ee100f169e7eb0282a873)
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                             unsigned DependencyKind, 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 = new (C) struct LambdaDefinitionData(
155       R, Info, DependencyKind, IsGeneric, CaptureDefault);
156   R->setMayHaveOutOfDateDef(false);
157   R->setImplicit(true);
158 
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 member functions.
829   if (const auto *Method = dyn_cast<CXXMethodDecl>(D)) {
830     if (isa<CXXDestructorDecl>(D))
831       SMKind |= SMF_Destructor;
832 
833     if (Method->isCopyAssignmentOperator()) {
834       SMKind |= SMF_CopyAssignment;
835 
836       const auto *ParamTy =
837           Method->getParamDecl(0)->getType()->getAs<ReferenceType>();
838       if (!ParamTy || ParamTy->getPointeeType().isConstQualified())
839         data().HasDeclaredCopyAssignmentWithConstParam = true;
840     }
841 
842     if (Method->isMoveAssignmentOperator())
843       SMKind |= SMF_MoveAssignment;
844 
845     // Keep the list of conversion functions up-to-date.
846     if (auto *Conversion = dyn_cast<CXXConversionDecl>(D)) {
847       // FIXME: We use the 'unsafe' accessor for the access specifier here,
848       // because Sema may not have set it yet. That's really just a misdesign
849       // in Sema. However, LLDB *will* have set the access specifier correctly,
850       // and adds declarations after the class is technically completed,
851       // so completeDefinition()'s overriding of the access specifiers doesn't
852       // work.
853       AccessSpecifier AS = Conversion->getAccessUnsafe();
854 
855       if (Conversion->getPrimaryTemplate()) {
856         // We don't record specializations.
857       } else {
858         ASTContext &Ctx = getASTContext();
859         ASTUnresolvedSet &Conversions = data().Conversions.get(Ctx);
860         NamedDecl *Primary =
861             FunTmpl ? cast<NamedDecl>(FunTmpl) : cast<NamedDecl>(Conversion);
862         if (Primary->getPreviousDecl())
863           Conversions.replace(cast<NamedDecl>(Primary->getPreviousDecl()),
864                               Primary, AS);
865         else
866           Conversions.addDecl(Ctx, Primary, AS);
867       }
868     }
869 
870     if (SMKind) {
871       // If this is the first declaration of a special member, we no longer have
872       // an implicit trivial special member.
873       data().HasTrivialSpecialMembers &=
874           data().DeclaredSpecialMembers | ~SMKind;
875       data().HasTrivialSpecialMembersForCall &=
876           data().DeclaredSpecialMembers | ~SMKind;
877 
878       // Note when we have declared a declared special member, and suppress the
879       // implicit declaration of this special member.
880       data().DeclaredSpecialMembers |= SMKind;
881       if (!Method->isImplicit()) {
882         data().UserDeclaredSpecialMembers |= SMKind;
883 
884         // C++03 [class]p4:
885         //   A POD-struct is an aggregate class that has [...] no user-defined
886         //   copy assignment operator and no user-defined destructor.
887         //
888         // Since the POD bit is meant to be C++03 POD-ness, and in C++03,
889         // aggregates could not have any constructors, clear it even for an
890         // explicitly defaulted or deleted constructor.
891         // type is technically an aggregate in C++0x since it wouldn't be in 03.
892         //
893         // Also, a user-declared move assignment operator makes a class non-POD.
894         // This is an extension in C++03.
895         data().PlainOldData = false;
896       }
897       // We delay updating destructor relevant properties until
898       // addedSelectedDestructor.
899       // FIXME: Defer this for the other special member functions as well.
900       if (!Method->isIneligibleOrNotSelected()) {
901         addedEligibleSpecialMemberFunction(Method, SMKind);
902       }
903     }
904 
905     return;
906   }
907 
908   // Handle non-static data members.
909   if (const auto *Field = dyn_cast<FieldDecl>(D)) {
910     ASTContext &Context = getASTContext();
911 
912     // C++2a [class]p7:
913     //   A standard-layout class is a class that:
914     //    [...]
915     //    -- has all non-static data members and bit-fields in the class and
916     //       its base classes first declared in the same class
917     if (data().HasBasesWithFields)
918       data().IsStandardLayout = false;
919 
920     // C++ [class.bit]p2:
921     //   A declaration for a bit-field that omits the identifier declares an
922     //   unnamed bit-field. Unnamed bit-fields are not members and cannot be
923     //   initialized.
924     if (Field->isUnnamedBitfield()) {
925       // C++ [meta.unary.prop]p4: [LWG2358]
926       //   T is a class type [...] with [...] no unnamed bit-fields of non-zero
927       //   length
928       if (data().Empty && !Field->isZeroLengthBitField(Context) &&
929           Context.getLangOpts().getClangABICompat() >
930               LangOptions::ClangABI::Ver6)
931         data().Empty = false;
932       return;
933     }
934 
935     // C++11 [class]p7:
936     //   A standard-layout class is a class that:
937     //    -- either has no non-static data members in the most derived class
938     //       [...] or has no base classes with non-static data members
939     if (data().HasBasesWithNonStaticDataMembers)
940       data().IsCXX11StandardLayout = false;
941 
942     // C++ [dcl.init.aggr]p1:
943     //   An aggregate is an array or a class (clause 9) with [...] no
944     //   private or protected non-static data members (clause 11).
945     //
946     // A POD must be an aggregate.
947     if (D->getAccess() == AS_private || D->getAccess() == AS_protected) {
948       data().Aggregate = false;
949       data().PlainOldData = false;
950 
951       // C++20 [temp.param]p7:
952       //   A structural type is [...] a literal class type [for which] all
953       //   non-static data members are public
954       data().StructuralIfLiteral = false;
955     }
956 
957     // Track whether this is the first field. We use this when checking
958     // whether the class is standard-layout below.
959     bool IsFirstField = !data().HasPrivateFields &&
960                         !data().HasProtectedFields && !data().HasPublicFields;
961 
962     // C++0x [class]p7:
963     //   A standard-layout class is a class that:
964     //    [...]
965     //    -- has the same access control for all non-static data members,
966     switch (D->getAccess()) {
967     case AS_private:    data().HasPrivateFields = true;   break;
968     case AS_protected:  data().HasProtectedFields = true; break;
969     case AS_public:     data().HasPublicFields = true;    break;
970     case AS_none:       llvm_unreachable("Invalid access specifier");
971     };
972     if ((data().HasPrivateFields + data().HasProtectedFields +
973          data().HasPublicFields) > 1) {
974       data().IsStandardLayout = false;
975       data().IsCXX11StandardLayout = false;
976     }
977 
978     // Keep track of the presence of mutable fields.
979     if (Field->isMutable()) {
980       data().HasMutableFields = true;
981 
982       // C++20 [temp.param]p7:
983       //   A structural type is [...] a literal class type [for which] all
984       //   non-static data members are public
985       data().StructuralIfLiteral = false;
986     }
987 
988     // C++11 [class.union]p8, DR1460:
989     //   If X is a union, a non-static data member of X that is not an anonymous
990     //   union is a variant member of X.
991     if (isUnion() && !Field->isAnonymousStructOrUnion())
992       data().HasVariantMembers = true;
993 
994     // C++0x [class]p9:
995     //   A POD struct is a class that is both a trivial class and a
996     //   standard-layout class, and has no non-static data members of type
997     //   non-POD struct, non-POD union (or array of such types).
998     //
999     // Automatic Reference Counting: the presence of a member of Objective-C pointer type
1000     // that does not explicitly have no lifetime makes the class a non-POD.
1001     QualType T = Context.getBaseElementType(Field->getType());
1002     if (T->isObjCRetainableType() || T.isObjCGCStrong()) {
1003       if (T.hasNonTrivialObjCLifetime()) {
1004         // Objective-C Automatic Reference Counting:
1005         //   If a class has a non-static data member of Objective-C pointer
1006         //   type (or array thereof), it is a non-POD type and its
1007         //   default constructor (if any), copy constructor, move constructor,
1008         //   copy assignment operator, move assignment operator, and destructor are
1009         //   non-trivial.
1010         setHasObjectMember(true);
1011         struct DefinitionData &Data = data();
1012         Data.PlainOldData = false;
1013         Data.HasTrivialSpecialMembers = 0;
1014 
1015         // __strong or __weak fields do not make special functions non-trivial
1016         // for the purpose of calls.
1017         Qualifiers::ObjCLifetime LT = T.getQualifiers().getObjCLifetime();
1018         if (LT != Qualifiers::OCL_Strong && LT != Qualifiers::OCL_Weak)
1019           data().HasTrivialSpecialMembersForCall = 0;
1020 
1021         // Structs with __weak fields should never be passed directly.
1022         if (LT == Qualifiers::OCL_Weak)
1023           setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
1024 
1025         Data.HasIrrelevantDestructor = false;
1026 
1027         if (isUnion()) {
1028           data().DefaultedCopyConstructorIsDeleted = true;
1029           data().DefaultedMoveConstructorIsDeleted = true;
1030           data().DefaultedCopyAssignmentIsDeleted = true;
1031           data().DefaultedMoveAssignmentIsDeleted = true;
1032           data().DefaultedDestructorIsDeleted = true;
1033           data().NeedOverloadResolutionForCopyConstructor = true;
1034           data().NeedOverloadResolutionForMoveConstructor = true;
1035           data().NeedOverloadResolutionForCopyAssignment = true;
1036           data().NeedOverloadResolutionForMoveAssignment = true;
1037           data().NeedOverloadResolutionForDestructor = true;
1038         }
1039       } else if (!Context.getLangOpts().ObjCAutoRefCount) {
1040         setHasObjectMember(true);
1041       }
1042     } else if (!T.isCXX98PODType(Context))
1043       data().PlainOldData = false;
1044 
1045     if (T->isReferenceType()) {
1046       if (!Field->hasInClassInitializer())
1047         data().HasUninitializedReferenceMember = true;
1048 
1049       // C++0x [class]p7:
1050       //   A standard-layout class is a class that:
1051       //    -- has no non-static data members of type [...] reference,
1052       data().IsStandardLayout = false;
1053       data().IsCXX11StandardLayout = false;
1054 
1055       // C++1z [class.copy.ctor]p10:
1056       //   A defaulted copy constructor for a class X is defined as deleted if X has:
1057       //    -- a non-static data member of rvalue reference type
1058       if (T->isRValueReferenceType())
1059         data().DefaultedCopyConstructorIsDeleted = true;
1060     }
1061 
1062     if (!Field->hasInClassInitializer() && !Field->isMutable()) {
1063       if (CXXRecordDecl *FieldType = T->getAsCXXRecordDecl()) {
1064         if (FieldType->hasDefinition() && !FieldType->allowConstDefaultInit())
1065           data().HasUninitializedFields = true;
1066       } else {
1067         data().HasUninitializedFields = true;
1068       }
1069     }
1070 
1071     // Record if this field is the first non-literal or volatile field or base.
1072     if (!T->isLiteralType(Context) || T.isVolatileQualified())
1073       data().HasNonLiteralTypeFieldsOrBases = true;
1074 
1075     if (Field->hasInClassInitializer() ||
1076         (Field->isAnonymousStructOrUnion() &&
1077          Field->getType()->getAsCXXRecordDecl()->hasInClassInitializer())) {
1078       data().HasInClassInitializer = true;
1079 
1080       // C++11 [class]p5:
1081       //   A default constructor is trivial if [...] no non-static data member
1082       //   of its class has a brace-or-equal-initializer.
1083       data().HasTrivialSpecialMembers &= ~SMF_DefaultConstructor;
1084 
1085       // C++11 [dcl.init.aggr]p1:
1086       //   An aggregate is a [...] class with [...] no
1087       //   brace-or-equal-initializers for non-static data members.
1088       //
1089       // This rule was removed in C++14.
1090       if (!getASTContext().getLangOpts().CPlusPlus14)
1091         data().Aggregate = false;
1092 
1093       // C++11 [class]p10:
1094       //   A POD struct is [...] a trivial class.
1095       data().PlainOldData = false;
1096     }
1097 
1098     // C++11 [class.copy]p23:
1099     //   A defaulted copy/move assignment operator for a class X is defined
1100     //   as deleted if X has:
1101     //    -- a non-static data member of reference type
1102     if (T->isReferenceType()) {
1103       data().DefaultedCopyAssignmentIsDeleted = true;
1104       data().DefaultedMoveAssignmentIsDeleted = true;
1105     }
1106 
1107     // Bitfields of length 0 are also zero-sized, but we already bailed out for
1108     // those because they are always unnamed.
1109     bool IsZeroSize = Field->isZeroSize(Context);
1110 
1111     if (const auto *RecordTy = T->getAs<RecordType>()) {
1112       auto *FieldRec = cast<CXXRecordDecl>(RecordTy->getDecl());
1113       if (FieldRec->getDefinition()) {
1114         addedClassSubobject(FieldRec);
1115 
1116         // We may need to perform overload resolution to determine whether a
1117         // field can be moved if it's const or volatile qualified.
1118         if (T.getCVRQualifiers() & (Qualifiers::Const | Qualifiers::Volatile)) {
1119           // We need to care about 'const' for the copy constructor because an
1120           // implicit copy constructor might be declared with a non-const
1121           // parameter.
1122           data().NeedOverloadResolutionForCopyConstructor = true;
1123           data().NeedOverloadResolutionForMoveConstructor = true;
1124           data().NeedOverloadResolutionForCopyAssignment = true;
1125           data().NeedOverloadResolutionForMoveAssignment = true;
1126         }
1127 
1128         // C++11 [class.ctor]p5, C++11 [class.copy]p11:
1129         //   A defaulted [special member] for a class X is defined as
1130         //   deleted if:
1131         //    -- X is a union-like class that has a variant member with a
1132         //       non-trivial [corresponding special member]
1133         if (isUnion()) {
1134           if (FieldRec->hasNonTrivialCopyConstructor())
1135             data().DefaultedCopyConstructorIsDeleted = true;
1136           if (FieldRec->hasNonTrivialMoveConstructor())
1137             data().DefaultedMoveConstructorIsDeleted = true;
1138           if (FieldRec->hasNonTrivialCopyAssignment())
1139             data().DefaultedCopyAssignmentIsDeleted = true;
1140           if (FieldRec->hasNonTrivialMoveAssignment())
1141             data().DefaultedMoveAssignmentIsDeleted = true;
1142           if (FieldRec->hasNonTrivialDestructor())
1143             data().DefaultedDestructorIsDeleted = true;
1144         }
1145 
1146         // For an anonymous union member, our overload resolution will perform
1147         // overload resolution for its members.
1148         if (Field->isAnonymousStructOrUnion()) {
1149           data().NeedOverloadResolutionForCopyConstructor |=
1150               FieldRec->data().NeedOverloadResolutionForCopyConstructor;
1151           data().NeedOverloadResolutionForMoveConstructor |=
1152               FieldRec->data().NeedOverloadResolutionForMoveConstructor;
1153           data().NeedOverloadResolutionForCopyAssignment |=
1154               FieldRec->data().NeedOverloadResolutionForCopyAssignment;
1155           data().NeedOverloadResolutionForMoveAssignment |=
1156               FieldRec->data().NeedOverloadResolutionForMoveAssignment;
1157           data().NeedOverloadResolutionForDestructor |=
1158               FieldRec->data().NeedOverloadResolutionForDestructor;
1159         }
1160 
1161         // C++0x [class.ctor]p5:
1162         //   A default constructor is trivial [...] if:
1163         //    -- for all the non-static data members of its class that are of
1164         //       class type (or array thereof), each such class has a trivial
1165         //       default constructor.
1166         if (!FieldRec->hasTrivialDefaultConstructor())
1167           data().HasTrivialSpecialMembers &= ~SMF_DefaultConstructor;
1168 
1169         // C++0x [class.copy]p13:
1170         //   A copy/move constructor for class X is trivial if [...]
1171         //    [...]
1172         //    -- for each non-static data member of X that is of class type (or
1173         //       an array thereof), the constructor selected to copy/move that
1174         //       member is trivial;
1175         if (!FieldRec->hasTrivialCopyConstructor())
1176           data().HasTrivialSpecialMembers &= ~SMF_CopyConstructor;
1177 
1178         if (!FieldRec->hasTrivialCopyConstructorForCall())
1179           data().HasTrivialSpecialMembersForCall &= ~SMF_CopyConstructor;
1180 
1181         // If the field doesn't have a simple move constructor, we'll eagerly
1182         // declare the move constructor for this class and we'll decide whether
1183         // it's trivial then.
1184         if (!FieldRec->hasTrivialMoveConstructor())
1185           data().HasTrivialSpecialMembers &= ~SMF_MoveConstructor;
1186 
1187         if (!FieldRec->hasTrivialMoveConstructorForCall())
1188           data().HasTrivialSpecialMembersForCall &= ~SMF_MoveConstructor;
1189 
1190         // C++0x [class.copy]p27:
1191         //   A copy/move assignment operator for class X is trivial if [...]
1192         //    [...]
1193         //    -- for each non-static data member of X that is of class type (or
1194         //       an array thereof), the assignment operator selected to
1195         //       copy/move that member is trivial;
1196         if (!FieldRec->hasTrivialCopyAssignment())
1197           data().HasTrivialSpecialMembers &= ~SMF_CopyAssignment;
1198         // If the field doesn't have a simple move assignment, we'll eagerly
1199         // declare the move assignment for this class and we'll decide whether
1200         // it's trivial then.
1201         if (!FieldRec->hasTrivialMoveAssignment())
1202           data().HasTrivialSpecialMembers &= ~SMF_MoveAssignment;
1203 
1204         if (!FieldRec->hasTrivialDestructor())
1205           data().HasTrivialSpecialMembers &= ~SMF_Destructor;
1206         if (!FieldRec->hasTrivialDestructorForCall())
1207           data().HasTrivialSpecialMembersForCall &= ~SMF_Destructor;
1208         if (!FieldRec->hasIrrelevantDestructor())
1209           data().HasIrrelevantDestructor = false;
1210         if (FieldRec->isAnyDestructorNoReturn())
1211           data().IsAnyDestructorNoReturn = true;
1212         if (FieldRec->hasObjectMember())
1213           setHasObjectMember(true);
1214         if (FieldRec->hasVolatileMember())
1215           setHasVolatileMember(true);
1216         if (FieldRec->getArgPassingRestrictions() ==
1217             RecordDecl::APK_CanNeverPassInRegs)
1218           setArgPassingRestrictions(RecordDecl::APK_CanNeverPassInRegs);
1219 
1220         // C++0x [class]p7:
1221         //   A standard-layout class is a class that:
1222         //    -- has no non-static data members of type non-standard-layout
1223         //       class (or array of such types) [...]
1224         if (!FieldRec->isStandardLayout())
1225           data().IsStandardLayout = false;
1226         if (!FieldRec->isCXX11StandardLayout())
1227           data().IsCXX11StandardLayout = false;
1228 
1229         // C++2a [class]p7:
1230         //   A standard-layout class is a class that:
1231         //    [...]
1232         //    -- has no element of the set M(S) of types as a base class.
1233         if (data().IsStandardLayout &&
1234             (isUnion() || IsFirstField || IsZeroSize) &&
1235             hasSubobjectAtOffsetZeroOfEmptyBaseType(Context, FieldRec))
1236           data().IsStandardLayout = false;
1237 
1238         // C++11 [class]p7:
1239         //   A standard-layout class is a class that:
1240         //    -- has no base classes of the same type as the first non-static
1241         //       data member
1242         if (data().IsCXX11StandardLayout && IsFirstField) {
1243           // FIXME: We should check all base classes here, not just direct
1244           // base classes.
1245           for (const auto &BI : bases()) {
1246             if (Context.hasSameUnqualifiedType(BI.getType(), T)) {
1247               data().IsCXX11StandardLayout = false;
1248               break;
1249             }
1250           }
1251         }
1252 
1253         // Keep track of the presence of mutable fields.
1254         if (FieldRec->hasMutableFields())
1255           data().HasMutableFields = true;
1256 
1257         if (Field->isMutable()) {
1258           // Our copy constructor/assignment might call something other than
1259           // the subobject's copy constructor/assignment if it's mutable and of
1260           // class type.
1261           data().NeedOverloadResolutionForCopyConstructor = true;
1262           data().NeedOverloadResolutionForCopyAssignment = true;
1263         }
1264 
1265         // C++11 [class.copy]p13:
1266         //   If the implicitly-defined constructor would satisfy the
1267         //   requirements of a constexpr constructor, the implicitly-defined
1268         //   constructor is constexpr.
1269         // C++11 [dcl.constexpr]p4:
1270         //    -- every constructor involved in initializing non-static data
1271         //       members [...] shall be a constexpr constructor
1272         if (!Field->hasInClassInitializer() &&
1273             !FieldRec->hasConstexprDefaultConstructor() && !isUnion())
1274           // The standard requires any in-class initializer to be a constant
1275           // expression. We consider this to be a defect.
1276           data().DefaultedDefaultConstructorIsConstexpr = false;
1277 
1278         // C++11 [class.copy]p8:
1279         //   The implicitly-declared copy constructor for a class X will have
1280         //   the form 'X::X(const X&)' if each potentially constructed subobject
1281         //   of a class type M (or array thereof) has a copy constructor whose
1282         //   first parameter is of type 'const M&' or 'const volatile M&'.
1283         if (!FieldRec->hasCopyConstructorWithConstParam())
1284           data().ImplicitCopyConstructorCanHaveConstParamForNonVBase = false;
1285 
1286         // C++11 [class.copy]p18:
1287         //   The implicitly-declared copy assignment oeprator for a class X will
1288         //   have the form 'X& X::operator=(const X&)' if [...] for all the
1289         //   non-static data members of X that are of a class type M (or array
1290         //   thereof), each such class type has a copy assignment operator whose
1291         //   parameter is of type 'const M&', 'const volatile M&' or 'M'.
1292         if (!FieldRec->hasCopyAssignmentWithConstParam())
1293           data().ImplicitCopyAssignmentHasConstParam = false;
1294 
1295         if (FieldRec->hasUninitializedReferenceMember() &&
1296             !Field->hasInClassInitializer())
1297           data().HasUninitializedReferenceMember = true;
1298 
1299         // C++11 [class.union]p8, DR1460:
1300         //   a non-static data member of an anonymous union that is a member of
1301         //   X is also a variant member of X.
1302         if (FieldRec->hasVariantMembers() &&
1303             Field->isAnonymousStructOrUnion())
1304           data().HasVariantMembers = true;
1305       }
1306     } else {
1307       // Base element type of field is a non-class type.
1308       if (!T->isLiteralType(Context) ||
1309           (!Field->hasInClassInitializer() && !isUnion() &&
1310            !Context.getLangOpts().CPlusPlus20))
1311         data().DefaultedDefaultConstructorIsConstexpr = false;
1312 
1313       // C++11 [class.copy]p23:
1314       //   A defaulted copy/move assignment operator for a class X is defined
1315       //   as deleted if X has:
1316       //    -- a non-static data member of const non-class type (or array
1317       //       thereof)
1318       if (T.isConstQualified()) {
1319         data().DefaultedCopyAssignmentIsDeleted = true;
1320         data().DefaultedMoveAssignmentIsDeleted = true;
1321       }
1322 
1323       // C++20 [temp.param]p7:
1324       //   A structural type is [...] a literal class type [for which] the
1325       //   types of all non-static data members are structural types or
1326       //   (possibly multidimensional) array thereof
1327       // We deal with class types elsewhere.
1328       if (!T->isStructuralType())
1329         data().StructuralIfLiteral = false;
1330     }
1331 
1332     // C++14 [meta.unary.prop]p4:
1333     //   T is a class type [...] with [...] no non-static data members other
1334     //   than subobjects of zero size
1335     if (data().Empty && !IsZeroSize)
1336       data().Empty = false;
1337   }
1338 
1339   // Handle using declarations of conversion functions.
1340   if (auto *Shadow = dyn_cast<UsingShadowDecl>(D)) {
1341     if (Shadow->getDeclName().getNameKind()
1342           == DeclarationName::CXXConversionFunctionName) {
1343       ASTContext &Ctx = getASTContext();
1344       data().Conversions.get(Ctx).addDecl(Ctx, Shadow, Shadow->getAccess());
1345     }
1346   }
1347 
1348   if (const auto *Using = dyn_cast<UsingDecl>(D)) {
1349     if (Using->getDeclName().getNameKind() ==
1350         DeclarationName::CXXConstructorName) {
1351       data().HasInheritedConstructor = true;
1352       // C++1z [dcl.init.aggr]p1:
1353       //  An aggregate is [...] a class [...] with no inherited constructors
1354       data().Aggregate = false;
1355     }
1356 
1357     if (Using->getDeclName().getCXXOverloadedOperator() == OO_Equal)
1358       data().HasInheritedAssignment = true;
1359   }
1360 }
1361 
1362 void CXXRecordDecl::addedSelectedDestructor(CXXDestructorDecl *DD) {
1363   DD->setIneligibleOrNotSelected(false);
1364   addedEligibleSpecialMemberFunction(DD, SMF_Destructor);
1365 }
1366 
1367 void CXXRecordDecl::addedEligibleSpecialMemberFunction(const CXXMethodDecl *MD,
1368                                                unsigned SMKind) {
1369   if (const auto *DD = dyn_cast<CXXDestructorDecl>(MD)) {
1370     if (DD->isUserProvided())
1371       data().HasIrrelevantDestructor = false;
1372     // If the destructor is explicitly defaulted and not trivial or not public
1373     // or if the destructor is deleted, we clear HasIrrelevantDestructor in
1374     // finishedDefaultedOrDeletedMember.
1375 
1376     // C++11 [class.dtor]p5:
1377     //   A destructor is trivial if [...] the destructor is not virtual.
1378     if (DD->isVirtual()) {
1379       data().HasTrivialSpecialMembers &= ~SMF_Destructor;
1380       data().HasTrivialSpecialMembersForCall &= ~SMF_Destructor;
1381     }
1382 
1383     if (DD->isNoReturn())
1384       data().IsAnyDestructorNoReturn = true;
1385   }
1386 
1387   if (!MD->isImplicit() && !MD->isUserProvided()) {
1388     // This method is user-declared but not user-provided. We can't work
1389     // out whether it's trivial yet (not until we get to the end of the
1390     // class). We'll handle this method in
1391     // finishedDefaultedOrDeletedMember.
1392   } else if (MD->isTrivial()) {
1393     data().HasTrivialSpecialMembers |= SMKind;
1394     data().HasTrivialSpecialMembersForCall |= SMKind;
1395   } else if (MD->isTrivialForCall()) {
1396     data().HasTrivialSpecialMembersForCall |= SMKind;
1397     data().DeclaredNonTrivialSpecialMembers |= SMKind;
1398   } else {
1399     data().DeclaredNonTrivialSpecialMembers |= SMKind;
1400     // If this is a user-provided function, do not set
1401     // DeclaredNonTrivialSpecialMembersForCall here since we don't know
1402     // yet whether the method would be considered non-trivial for the
1403     // purpose of calls (attribute "trivial_abi" can be dropped from the
1404     // class later, which can change the special method's triviality).
1405     if (!MD->isUserProvided())
1406       data().DeclaredNonTrivialSpecialMembersForCall |= SMKind;
1407   }
1408 }
1409 
1410 void CXXRecordDecl::finishedDefaultedOrDeletedMember(CXXMethodDecl *D) {
1411   assert(!D->isImplicit() && !D->isUserProvided());
1412 
1413   // The kind of special member this declaration is, if any.
1414   unsigned SMKind = 0;
1415 
1416   if (const auto *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1417     if (Constructor->isDefaultConstructor()) {
1418       SMKind |= SMF_DefaultConstructor;
1419       if (Constructor->isConstexpr())
1420         data().HasConstexprDefaultConstructor = true;
1421     }
1422     if (Constructor->isCopyConstructor())
1423       SMKind |= SMF_CopyConstructor;
1424     else if (Constructor->isMoveConstructor())
1425       SMKind |= SMF_MoveConstructor;
1426     else if (Constructor->isConstexpr())
1427       // We may now know that the constructor is constexpr.
1428       data().HasConstexprNonCopyMoveConstructor = true;
1429   } else if (isa<CXXDestructorDecl>(D)) {
1430     SMKind |= SMF_Destructor;
1431     if (!D->isTrivial() || D->getAccess() != AS_public || D->isDeleted())
1432       data().HasIrrelevantDestructor = false;
1433   } else if (D->isCopyAssignmentOperator())
1434     SMKind |= SMF_CopyAssignment;
1435   else if (D->isMoveAssignmentOperator())
1436     SMKind |= SMF_MoveAssignment;
1437 
1438   // Update which trivial / non-trivial special members we have.
1439   // addedMember will have skipped this step for this member.
1440   if (D->isTrivial())
1441     data().HasTrivialSpecialMembers |= SMKind;
1442   else
1443     data().DeclaredNonTrivialSpecialMembers |= SMKind;
1444 }
1445 
1446 void CXXRecordDecl::setCaptures(ASTContext &Context,
1447                                 ArrayRef<LambdaCapture> Captures) {
1448   CXXRecordDecl::LambdaDefinitionData &Data = getLambdaData();
1449 
1450   // Copy captures.
1451   Data.NumCaptures = Captures.size();
1452   Data.NumExplicitCaptures = 0;
1453   Data.Captures = (LambdaCapture *)Context.Allocate(sizeof(LambdaCapture) *
1454                                                     Captures.size());
1455   LambdaCapture *ToCapture = Data.Captures;
1456   for (unsigned I = 0, N = Captures.size(); I != N; ++I) {
1457     if (Captures[I].isExplicit())
1458       ++Data.NumExplicitCaptures;
1459 
1460     *ToCapture++ = Captures[I];
1461   }
1462 
1463   if (!lambdaIsDefaultConstructibleAndAssignable())
1464     Data.DefaultedCopyAssignmentIsDeleted = true;
1465 }
1466 
1467 void CXXRecordDecl::setTrivialForCallFlags(CXXMethodDecl *D) {
1468   unsigned SMKind = 0;
1469 
1470   if (const auto *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1471     if (Constructor->isCopyConstructor())
1472       SMKind = SMF_CopyConstructor;
1473     else if (Constructor->isMoveConstructor())
1474       SMKind = SMF_MoveConstructor;
1475   } else if (isa<CXXDestructorDecl>(D))
1476     SMKind = SMF_Destructor;
1477 
1478   if (D->isTrivialForCall())
1479     data().HasTrivialSpecialMembersForCall |= SMKind;
1480   else
1481     data().DeclaredNonTrivialSpecialMembersForCall |= SMKind;
1482 }
1483 
1484 bool CXXRecordDecl::isCLike() const {
1485   if (getTagKind() == TTK_Class || getTagKind() == TTK_Interface ||
1486       !TemplateOrInstantiation.isNull())
1487     return false;
1488   if (!hasDefinition())
1489     return true;
1490 
1491   return isPOD() && data().HasOnlyCMembers;
1492 }
1493 
1494 bool CXXRecordDecl::isGenericLambda() const {
1495   if (!isLambda()) return false;
1496   return getLambdaData().IsGenericLambda;
1497 }
1498 
1499 #ifndef NDEBUG
1500 static bool allLookupResultsAreTheSame(const DeclContext::lookup_result &R) {
1501   for (auto *D : R)
1502     if (!declaresSameEntity(D, R.front()))
1503       return false;
1504   return true;
1505 }
1506 #endif
1507 
1508 static NamedDecl* getLambdaCallOperatorHelper(const CXXRecordDecl &RD) {
1509   if (!RD.isLambda()) return nullptr;
1510   DeclarationName Name =
1511     RD.getASTContext().DeclarationNames.getCXXOperatorName(OO_Call);
1512   DeclContext::lookup_result Calls = RD.lookup(Name);
1513 
1514   assert(!Calls.empty() && "Missing lambda call operator!");
1515   assert(allLookupResultsAreTheSame(Calls) &&
1516          "More than one lambda call operator!");
1517   return Calls.front();
1518 }
1519 
1520 FunctionTemplateDecl* CXXRecordDecl::getDependentLambdaCallOperator() const {
1521   NamedDecl *CallOp = getLambdaCallOperatorHelper(*this);
1522   return  dyn_cast_or_null<FunctionTemplateDecl>(CallOp);
1523 }
1524 
1525 CXXMethodDecl *CXXRecordDecl::getLambdaCallOperator() const {
1526   NamedDecl *CallOp = getLambdaCallOperatorHelper(*this);
1527 
1528   if (CallOp == nullptr)
1529     return nullptr;
1530 
1531   if (const auto *CallOpTmpl = dyn_cast<FunctionTemplateDecl>(CallOp))
1532     return cast<CXXMethodDecl>(CallOpTmpl->getTemplatedDecl());
1533 
1534   return cast<CXXMethodDecl>(CallOp);
1535 }
1536 
1537 CXXMethodDecl* CXXRecordDecl::getLambdaStaticInvoker() const {
1538   CXXMethodDecl *CallOp = getLambdaCallOperator();
1539   CallingConv CC = CallOp->getType()->castAs<FunctionType>()->getCallConv();
1540   return getLambdaStaticInvoker(CC);
1541 }
1542 
1543 static DeclContext::lookup_result
1544 getLambdaStaticInvokers(const CXXRecordDecl &RD) {
1545   assert(RD.isLambda() && "Must be a lambda");
1546   DeclarationName Name =
1547       &RD.getASTContext().Idents.get(getLambdaStaticInvokerName());
1548   return RD.lookup(Name);
1549 }
1550 
1551 static CXXMethodDecl *getInvokerAsMethod(NamedDecl *ND) {
1552   if (const auto *InvokerTemplate = dyn_cast<FunctionTemplateDecl>(ND))
1553     return cast<CXXMethodDecl>(InvokerTemplate->getTemplatedDecl());
1554   return cast<CXXMethodDecl>(ND);
1555 }
1556 
1557 CXXMethodDecl *CXXRecordDecl::getLambdaStaticInvoker(CallingConv CC) const {
1558   if (!isLambda())
1559     return nullptr;
1560   DeclContext::lookup_result Invoker = getLambdaStaticInvokers(*this);
1561 
1562   for (NamedDecl *ND : Invoker) {
1563     const auto *FTy =
1564         cast<ValueDecl>(ND->getAsFunction())->getType()->castAs<FunctionType>();
1565     if (FTy->getCallConv() == CC)
1566       return getInvokerAsMethod(ND);
1567   }
1568 
1569   return nullptr;
1570 }
1571 
1572 void CXXRecordDecl::getCaptureFields(
1573        llvm::DenseMap<const VarDecl *, FieldDecl *> &Captures,
1574        FieldDecl *&ThisCapture) const {
1575   Captures.clear();
1576   ThisCapture = nullptr;
1577 
1578   LambdaDefinitionData &Lambda = getLambdaData();
1579   RecordDecl::field_iterator Field = field_begin();
1580   for (const LambdaCapture *C = Lambda.Captures, *CEnd = C + Lambda.NumCaptures;
1581        C != CEnd; ++C, ++Field) {
1582     if (C->capturesThis())
1583       ThisCapture = *Field;
1584     else if (C->capturesVariable())
1585       Captures[C->getCapturedVar()] = *Field;
1586   }
1587   assert(Field == field_end());
1588 }
1589 
1590 TemplateParameterList *
1591 CXXRecordDecl::getGenericLambdaTemplateParameterList() const {
1592   if (!isGenericLambda()) return nullptr;
1593   CXXMethodDecl *CallOp = getLambdaCallOperator();
1594   if (FunctionTemplateDecl *Tmpl = CallOp->getDescribedFunctionTemplate())
1595     return Tmpl->getTemplateParameters();
1596   return nullptr;
1597 }
1598 
1599 ArrayRef<NamedDecl *>
1600 CXXRecordDecl::getLambdaExplicitTemplateParameters() const {
1601   TemplateParameterList *List = getGenericLambdaTemplateParameterList();
1602   if (!List)
1603     return {};
1604 
1605   assert(std::is_partitioned(List->begin(), List->end(),
1606                              [](const NamedDecl *D) { return !D->isImplicit(); })
1607          && "Explicit template params should be ordered before implicit ones");
1608 
1609   const auto ExplicitEnd = llvm::partition_point(
1610       *List, [](const NamedDecl *D) { return !D->isImplicit(); });
1611   return llvm::makeArrayRef(List->begin(), ExplicitEnd);
1612 }
1613 
1614 Decl *CXXRecordDecl::getLambdaContextDecl() const {
1615   assert(isLambda() && "Not a lambda closure type!");
1616   ExternalASTSource *Source = getParentASTContext().getExternalSource();
1617   return getLambdaData().ContextDecl.get(Source);
1618 }
1619 
1620 void CXXRecordDecl::setDeviceLambdaManglingNumber(unsigned Num) const {
1621   assert(isLambda() && "Not a lambda closure type!");
1622   if (Num)
1623     getASTContext().DeviceLambdaManglingNumbers[this] = Num;
1624 }
1625 
1626 unsigned CXXRecordDecl::getDeviceLambdaManglingNumber() const {
1627   assert(isLambda() && "Not a lambda closure type!");
1628   auto I = getASTContext().DeviceLambdaManglingNumbers.find(this);
1629   if (I != getASTContext().DeviceLambdaManglingNumbers.end())
1630     return I->second;
1631   return 0;
1632 }
1633 
1634 static CanQualType GetConversionType(ASTContext &Context, NamedDecl *Conv) {
1635   QualType T =
1636       cast<CXXConversionDecl>(Conv->getUnderlyingDecl()->getAsFunction())
1637           ->getConversionType();
1638   return Context.getCanonicalType(T);
1639 }
1640 
1641 /// Collect the visible conversions of a base class.
1642 ///
1643 /// \param Record a base class of the class we're considering
1644 /// \param InVirtual whether this base class is a virtual base (or a base
1645 ///   of a virtual base)
1646 /// \param Access the access along the inheritance path to this base
1647 /// \param ParentHiddenTypes the conversions provided by the inheritors
1648 ///   of this base
1649 /// \param Output the set to which to add conversions from non-virtual bases
1650 /// \param VOutput the set to which to add conversions from virtual bases
1651 /// \param HiddenVBaseCs the set of conversions which were hidden in a
1652 ///   virtual base along some inheritance path
1653 static void CollectVisibleConversions(
1654     ASTContext &Context, const CXXRecordDecl *Record, bool InVirtual,
1655     AccessSpecifier Access,
1656     const llvm::SmallPtrSet<CanQualType, 8> &ParentHiddenTypes,
1657     ASTUnresolvedSet &Output, UnresolvedSetImpl &VOutput,
1658     llvm::SmallPtrSet<NamedDecl *, 8> &HiddenVBaseCs) {
1659   // The set of types which have conversions in this class or its
1660   // subclasses.  As an optimization, we don't copy the derived set
1661   // unless it might change.
1662   const llvm::SmallPtrSet<CanQualType, 8> *HiddenTypes = &ParentHiddenTypes;
1663   llvm::SmallPtrSet<CanQualType, 8> HiddenTypesBuffer;
1664 
1665   // Collect the direct conversions and figure out which conversions
1666   // will be hidden in the subclasses.
1667   CXXRecordDecl::conversion_iterator ConvI = Record->conversion_begin();
1668   CXXRecordDecl::conversion_iterator ConvE = Record->conversion_end();
1669   if (ConvI != ConvE) {
1670     HiddenTypesBuffer = ParentHiddenTypes;
1671     HiddenTypes = &HiddenTypesBuffer;
1672 
1673     for (CXXRecordDecl::conversion_iterator I = ConvI; I != ConvE; ++I) {
1674       CanQualType ConvType(GetConversionType(Context, I.getDecl()));
1675       bool Hidden = ParentHiddenTypes.count(ConvType);
1676       if (!Hidden)
1677         HiddenTypesBuffer.insert(ConvType);
1678 
1679       // If this conversion is hidden and we're in a virtual base,
1680       // remember that it's hidden along some inheritance path.
1681       if (Hidden && InVirtual)
1682         HiddenVBaseCs.insert(cast<NamedDecl>(I.getDecl()->getCanonicalDecl()));
1683 
1684       // If this conversion isn't hidden, add it to the appropriate output.
1685       else if (!Hidden) {
1686         AccessSpecifier IAccess
1687           = CXXRecordDecl::MergeAccess(Access, I.getAccess());
1688 
1689         if (InVirtual)
1690           VOutput.addDecl(I.getDecl(), IAccess);
1691         else
1692           Output.addDecl(Context, I.getDecl(), IAccess);
1693       }
1694     }
1695   }
1696 
1697   // Collect information recursively from any base classes.
1698   for (const auto &I : Record->bases()) {
1699     const auto *RT = I.getType()->getAs<RecordType>();
1700     if (!RT) continue;
1701 
1702     AccessSpecifier BaseAccess
1703       = CXXRecordDecl::MergeAccess(Access, I.getAccessSpecifier());
1704     bool BaseInVirtual = InVirtual || I.isVirtual();
1705 
1706     auto *Base = cast<CXXRecordDecl>(RT->getDecl());
1707     CollectVisibleConversions(Context, Base, BaseInVirtual, BaseAccess,
1708                               *HiddenTypes, Output, VOutput, HiddenVBaseCs);
1709   }
1710 }
1711 
1712 /// Collect the visible conversions of a class.
1713 ///
1714 /// This would be extremely straightforward if it weren't for virtual
1715 /// bases.  It might be worth special-casing that, really.
1716 static void CollectVisibleConversions(ASTContext &Context,
1717                                       const CXXRecordDecl *Record,
1718                                       ASTUnresolvedSet &Output) {
1719   // The collection of all conversions in virtual bases that we've
1720   // found.  These will be added to the output as long as they don't
1721   // appear in the hidden-conversions set.
1722   UnresolvedSet<8> VBaseCs;
1723 
1724   // The set of conversions in virtual bases that we've determined to
1725   // be hidden.
1726   llvm::SmallPtrSet<NamedDecl*, 8> HiddenVBaseCs;
1727 
1728   // The set of types hidden by classes derived from this one.
1729   llvm::SmallPtrSet<CanQualType, 8> HiddenTypes;
1730 
1731   // Go ahead and collect the direct conversions and add them to the
1732   // hidden-types set.
1733   CXXRecordDecl::conversion_iterator ConvI = Record->conversion_begin();
1734   CXXRecordDecl::conversion_iterator ConvE = Record->conversion_end();
1735   Output.append(Context, ConvI, ConvE);
1736   for (; ConvI != ConvE; ++ConvI)
1737     HiddenTypes.insert(GetConversionType(Context, ConvI.getDecl()));
1738 
1739   // Recursively collect conversions from base classes.
1740   for (const auto &I : Record->bases()) {
1741     const auto *RT = I.getType()->getAs<RecordType>();
1742     if (!RT) continue;
1743 
1744     CollectVisibleConversions(Context, cast<CXXRecordDecl>(RT->getDecl()),
1745                               I.isVirtual(), I.getAccessSpecifier(),
1746                               HiddenTypes, Output, VBaseCs, HiddenVBaseCs);
1747   }
1748 
1749   // Add any unhidden conversions provided by virtual bases.
1750   for (UnresolvedSetIterator I = VBaseCs.begin(), E = VBaseCs.end();
1751          I != E; ++I) {
1752     if (!HiddenVBaseCs.count(cast<NamedDecl>(I.getDecl()->getCanonicalDecl())))
1753       Output.addDecl(Context, I.getDecl(), I.getAccess());
1754   }
1755 }
1756 
1757 /// getVisibleConversionFunctions - get all conversion functions visible
1758 /// in current class; including conversion function templates.
1759 llvm::iterator_range<CXXRecordDecl::conversion_iterator>
1760 CXXRecordDecl::getVisibleConversionFunctions() const {
1761   ASTContext &Ctx = getASTContext();
1762 
1763   ASTUnresolvedSet *Set;
1764   if (bases_begin() == bases_end()) {
1765     // If root class, all conversions are visible.
1766     Set = &data().Conversions.get(Ctx);
1767   } else {
1768     Set = &data().VisibleConversions.get(Ctx);
1769     // If visible conversion list is not evaluated, evaluate it.
1770     if (!data().ComputedVisibleConversions) {
1771       CollectVisibleConversions(Ctx, this, *Set);
1772       data().ComputedVisibleConversions = true;
1773     }
1774   }
1775   return llvm::make_range(Set->begin(), Set->end());
1776 }
1777 
1778 void CXXRecordDecl::removeConversion(const NamedDecl *ConvDecl) {
1779   // This operation is O(N) but extremely rare.  Sema only uses it to
1780   // remove UsingShadowDecls in a class that were followed by a direct
1781   // declaration, e.g.:
1782   //   class A : B {
1783   //     using B::operator int;
1784   //     operator int();
1785   //   };
1786   // This is uncommon by itself and even more uncommon in conjunction
1787   // with sufficiently large numbers of directly-declared conversions
1788   // that asymptotic behavior matters.
1789 
1790   ASTUnresolvedSet &Convs = data().Conversions.get(getASTContext());
1791   for (unsigned I = 0, E = Convs.size(); I != E; ++I) {
1792     if (Convs[I].getDecl() == ConvDecl) {
1793       Convs.erase(I);
1794       assert(!llvm::is_contained(Convs, ConvDecl) &&
1795              "conversion was found multiple times in unresolved set");
1796       return;
1797     }
1798   }
1799 
1800   llvm_unreachable("conversion not found in set!");
1801 }
1802 
1803 CXXRecordDecl *CXXRecordDecl::getInstantiatedFromMemberClass() const {
1804   if (MemberSpecializationInfo *MSInfo = getMemberSpecializationInfo())
1805     return cast<CXXRecordDecl>(MSInfo->getInstantiatedFrom());
1806 
1807   return nullptr;
1808 }
1809 
1810 MemberSpecializationInfo *CXXRecordDecl::getMemberSpecializationInfo() const {
1811   return TemplateOrInstantiation.dyn_cast<MemberSpecializationInfo *>();
1812 }
1813 
1814 void
1815 CXXRecordDecl::setInstantiationOfMemberClass(CXXRecordDecl *RD,
1816                                              TemplateSpecializationKind TSK) {
1817   assert(TemplateOrInstantiation.isNull() &&
1818          "Previous template or instantiation?");
1819   assert(!isa<ClassTemplatePartialSpecializationDecl>(this));
1820   TemplateOrInstantiation
1821     = new (getASTContext()) MemberSpecializationInfo(RD, TSK);
1822 }
1823 
1824 ClassTemplateDecl *CXXRecordDecl::getDescribedClassTemplate() const {
1825   return TemplateOrInstantiation.dyn_cast<ClassTemplateDecl *>();
1826 }
1827 
1828 void CXXRecordDecl::setDescribedClassTemplate(ClassTemplateDecl *Template) {
1829   TemplateOrInstantiation = Template;
1830 }
1831 
1832 TemplateSpecializationKind CXXRecordDecl::getTemplateSpecializationKind() const{
1833   if (const auto *Spec = dyn_cast<ClassTemplateSpecializationDecl>(this))
1834     return Spec->getSpecializationKind();
1835 
1836   if (MemberSpecializationInfo *MSInfo = getMemberSpecializationInfo())
1837     return MSInfo->getTemplateSpecializationKind();
1838 
1839   return TSK_Undeclared;
1840 }
1841 
1842 void
1843 CXXRecordDecl::setTemplateSpecializationKind(TemplateSpecializationKind TSK) {
1844   if (auto *Spec = dyn_cast<ClassTemplateSpecializationDecl>(this)) {
1845     Spec->setSpecializationKind(TSK);
1846     return;
1847   }
1848 
1849   if (MemberSpecializationInfo *MSInfo = getMemberSpecializationInfo()) {
1850     MSInfo->setTemplateSpecializationKind(TSK);
1851     return;
1852   }
1853 
1854   llvm_unreachable("Not a class template or member class specialization");
1855 }
1856 
1857 const CXXRecordDecl *CXXRecordDecl::getTemplateInstantiationPattern() const {
1858   auto GetDefinitionOrSelf =
1859       [](const CXXRecordDecl *D) -> const CXXRecordDecl * {
1860     if (auto *Def = D->getDefinition())
1861       return Def;
1862     return D;
1863   };
1864 
1865   // If it's a class template specialization, find the template or partial
1866   // specialization from which it was instantiated.
1867   if (auto *TD = dyn_cast<ClassTemplateSpecializationDecl>(this)) {
1868     auto From = TD->getInstantiatedFrom();
1869     if (auto *CTD = From.dyn_cast<ClassTemplateDecl *>()) {
1870       while (auto *NewCTD = CTD->getInstantiatedFromMemberTemplate()) {
1871         if (NewCTD->isMemberSpecialization())
1872           break;
1873         CTD = NewCTD;
1874       }
1875       return GetDefinitionOrSelf(CTD->getTemplatedDecl());
1876     }
1877     if (auto *CTPSD =
1878             From.dyn_cast<ClassTemplatePartialSpecializationDecl *>()) {
1879       while (auto *NewCTPSD = CTPSD->getInstantiatedFromMember()) {
1880         if (NewCTPSD->isMemberSpecialization())
1881           break;
1882         CTPSD = NewCTPSD;
1883       }
1884       return GetDefinitionOrSelf(CTPSD);
1885     }
1886   }
1887 
1888   if (MemberSpecializationInfo *MSInfo = getMemberSpecializationInfo()) {
1889     if (isTemplateInstantiation(MSInfo->getTemplateSpecializationKind())) {
1890       const CXXRecordDecl *RD = this;
1891       while (auto *NewRD = RD->getInstantiatedFromMemberClass())
1892         RD = NewRD;
1893       return GetDefinitionOrSelf(RD);
1894     }
1895   }
1896 
1897   assert(!isTemplateInstantiation(this->getTemplateSpecializationKind()) &&
1898          "couldn't find pattern for class template instantiation");
1899   return nullptr;
1900 }
1901 
1902 CXXDestructorDecl *CXXRecordDecl::getDestructor() const {
1903   ASTContext &Context = getASTContext();
1904   QualType ClassType = Context.getTypeDeclType(this);
1905 
1906   DeclarationName Name
1907     = Context.DeclarationNames.getCXXDestructorName(
1908                                           Context.getCanonicalType(ClassType));
1909 
1910   DeclContext::lookup_result R = lookup(Name);
1911 
1912   // If a destructor was marked as not selected, we skip it. We don't always
1913   // have a selected destructor: dependent types, unnamed structs.
1914   for (auto *Decl : R) {
1915     auto* DD = dyn_cast<CXXDestructorDecl>(Decl);
1916     if (DD && !DD->isIneligibleOrNotSelected())
1917       return DD;
1918   }
1919   return nullptr;
1920 }
1921 
1922 static bool isDeclContextInNamespace(const DeclContext *DC) {
1923   while (!DC->isTranslationUnit()) {
1924     if (DC->isNamespace())
1925       return true;
1926     DC = DC->getParent();
1927   }
1928   return false;
1929 }
1930 
1931 bool CXXRecordDecl::isInterfaceLike() const {
1932   assert(hasDefinition() && "checking for interface-like without a definition");
1933   // All __interfaces are inheritently interface-like.
1934   if (isInterface())
1935     return true;
1936 
1937   // Interface-like types cannot have a user declared constructor, destructor,
1938   // friends, VBases, conversion functions, or fields.  Additionally, lambdas
1939   // cannot be interface types.
1940   if (isLambda() || hasUserDeclaredConstructor() ||
1941       hasUserDeclaredDestructor() || !field_empty() || hasFriends() ||
1942       getNumVBases() > 0 || conversion_end() - conversion_begin() > 0)
1943     return false;
1944 
1945   // No interface-like type can have a method with a definition.
1946   for (const auto *const Method : methods())
1947     if (Method->isDefined() && !Method->isImplicit())
1948       return false;
1949 
1950   // Check "Special" types.
1951   const auto *Uuid = getAttr<UuidAttr>();
1952   // MS SDK declares IUnknown/IDispatch both in the root of a TU, or in an
1953   // extern C++ block directly in the TU.  These are only valid if in one
1954   // of these two situations.
1955   if (Uuid && isStruct() && !getDeclContext()->isExternCContext() &&
1956       !isDeclContextInNamespace(getDeclContext()) &&
1957       ((getName() == "IUnknown" &&
1958         Uuid->getGuid() == "00000000-0000-0000-C000-000000000046") ||
1959        (getName() == "IDispatch" &&
1960         Uuid->getGuid() == "00020400-0000-0000-C000-000000000046"))) {
1961     if (getNumBases() > 0)
1962       return false;
1963     return true;
1964   }
1965 
1966   // FIXME: Any access specifiers is supposed to make this no longer interface
1967   // like.
1968 
1969   // If this isn't a 'special' type, it must have a single interface-like base.
1970   if (getNumBases() != 1)
1971     return false;
1972 
1973   const auto BaseSpec = *bases_begin();
1974   if (BaseSpec.isVirtual() || BaseSpec.getAccessSpecifier() != AS_public)
1975     return false;
1976   const auto *Base = BaseSpec.getType()->getAsCXXRecordDecl();
1977   if (Base->isInterface() || !Base->isInterfaceLike())
1978     return false;
1979   return true;
1980 }
1981 
1982 void CXXRecordDecl::completeDefinition() {
1983   completeDefinition(nullptr);
1984 }
1985 
1986 void CXXRecordDecl::completeDefinition(CXXFinalOverriderMap *FinalOverriders) {
1987   RecordDecl::completeDefinition();
1988 
1989   // If the class may be abstract (but hasn't been marked as such), check for
1990   // any pure final overriders.
1991   if (mayBeAbstract()) {
1992     CXXFinalOverriderMap MyFinalOverriders;
1993     if (!FinalOverriders) {
1994       getFinalOverriders(MyFinalOverriders);
1995       FinalOverriders = &MyFinalOverriders;
1996     }
1997 
1998     bool Done = false;
1999     for (CXXFinalOverriderMap::iterator M = FinalOverriders->begin(),
2000                                      MEnd = FinalOverriders->end();
2001          M != MEnd && !Done; ++M) {
2002       for (OverridingMethods::iterator SO = M->second.begin(),
2003                                     SOEnd = M->second.end();
2004            SO != SOEnd && !Done; ++SO) {
2005         assert(SO->second.size() > 0 &&
2006                "All virtual functions have overriding virtual functions");
2007 
2008         // C++ [class.abstract]p4:
2009         //   A class is abstract if it contains or inherits at least one
2010         //   pure virtual function for which the final overrider is pure
2011         //   virtual.
2012         if (SO->second.front().Method->isPure()) {
2013           data().Abstract = true;
2014           Done = true;
2015           break;
2016         }
2017       }
2018     }
2019   }
2020 
2021   // Set access bits correctly on the directly-declared conversions.
2022   for (conversion_iterator I = conversion_begin(), E = conversion_end();
2023        I != E; ++I)
2024     I.setAccess((*I)->getAccess());
2025 }
2026 
2027 bool CXXRecordDecl::mayBeAbstract() const {
2028   if (data().Abstract || isInvalidDecl() || !data().Polymorphic ||
2029       isDependentContext())
2030     return false;
2031 
2032   for (const auto &B : bases()) {
2033     const auto *BaseDecl =
2034         cast<CXXRecordDecl>(B.getType()->castAs<RecordType>()->getDecl());
2035     if (BaseDecl->isAbstract())
2036       return true;
2037   }
2038 
2039   return false;
2040 }
2041 
2042 bool CXXRecordDecl::isEffectivelyFinal() const {
2043   auto *Def = getDefinition();
2044   if (!Def)
2045     return false;
2046   if (Def->hasAttr<FinalAttr>())
2047     return true;
2048   if (const auto *Dtor = Def->getDestructor())
2049     if (Dtor->hasAttr<FinalAttr>())
2050       return true;
2051   return false;
2052 }
2053 
2054 void CXXDeductionGuideDecl::anchor() {}
2055 
2056 bool ExplicitSpecifier::isEquivalent(const ExplicitSpecifier Other) const {
2057   if ((getKind() != Other.getKind() ||
2058        getKind() == ExplicitSpecKind::Unresolved)) {
2059     if (getKind() == ExplicitSpecKind::Unresolved &&
2060         Other.getKind() == ExplicitSpecKind::Unresolved) {
2061       ODRHash SelfHash, OtherHash;
2062       SelfHash.AddStmt(getExpr());
2063       OtherHash.AddStmt(Other.getExpr());
2064       return SelfHash.CalculateHash() == OtherHash.CalculateHash();
2065     } else
2066       return false;
2067   }
2068   return true;
2069 }
2070 
2071 ExplicitSpecifier ExplicitSpecifier::getFromDecl(FunctionDecl *Function) {
2072   switch (Function->getDeclKind()) {
2073   case Decl::Kind::CXXConstructor:
2074     return cast<CXXConstructorDecl>(Function)->getExplicitSpecifier();
2075   case Decl::Kind::CXXConversion:
2076     return cast<CXXConversionDecl>(Function)->getExplicitSpecifier();
2077   case Decl::Kind::CXXDeductionGuide:
2078     return cast<CXXDeductionGuideDecl>(Function)->getExplicitSpecifier();
2079   default:
2080     return {};
2081   }
2082 }
2083 
2084 CXXDeductionGuideDecl *
2085 CXXDeductionGuideDecl::Create(ASTContext &C, DeclContext *DC,
2086                               SourceLocation StartLoc, ExplicitSpecifier ES,
2087                               const DeclarationNameInfo &NameInfo, QualType T,
2088                               TypeSourceInfo *TInfo, SourceLocation EndLocation,
2089                               CXXConstructorDecl *Ctor) {
2090   return new (C, DC) CXXDeductionGuideDecl(C, DC, StartLoc, ES, NameInfo, T,
2091                                            TInfo, EndLocation, Ctor);
2092 }
2093 
2094 CXXDeductionGuideDecl *CXXDeductionGuideDecl::CreateDeserialized(ASTContext &C,
2095                                                                  unsigned ID) {
2096   return new (C, ID) CXXDeductionGuideDecl(
2097       C, nullptr, SourceLocation(), ExplicitSpecifier(), DeclarationNameInfo(),
2098       QualType(), nullptr, SourceLocation(), nullptr);
2099 }
2100 
2101 RequiresExprBodyDecl *RequiresExprBodyDecl::Create(
2102     ASTContext &C, DeclContext *DC, SourceLocation StartLoc) {
2103   return new (C, DC) RequiresExprBodyDecl(C, DC, StartLoc);
2104 }
2105 
2106 RequiresExprBodyDecl *RequiresExprBodyDecl::CreateDeserialized(ASTContext &C,
2107                                                                unsigned ID) {
2108   return new (C, ID) RequiresExprBodyDecl(C, nullptr, SourceLocation());
2109 }
2110 
2111 void CXXMethodDecl::anchor() {}
2112 
2113 bool CXXMethodDecl::isStatic() const {
2114   const CXXMethodDecl *MD = getCanonicalDecl();
2115 
2116   if (MD->getStorageClass() == SC_Static)
2117     return true;
2118 
2119   OverloadedOperatorKind OOK = getDeclName().getCXXOverloadedOperator();
2120   return isStaticOverloadedOperator(OOK);
2121 }
2122 
2123 static bool recursivelyOverrides(const CXXMethodDecl *DerivedMD,
2124                                  const CXXMethodDecl *BaseMD) {
2125   for (const CXXMethodDecl *MD : DerivedMD->overridden_methods()) {
2126     if (MD->getCanonicalDecl() == BaseMD->getCanonicalDecl())
2127       return true;
2128     if (recursivelyOverrides(MD, BaseMD))
2129       return true;
2130   }
2131   return false;
2132 }
2133 
2134 CXXMethodDecl *
2135 CXXMethodDecl::getCorrespondingMethodDeclaredInClass(const CXXRecordDecl *RD,
2136                                                      bool MayBeBase) {
2137   if (this->getParent()->getCanonicalDecl() == RD->getCanonicalDecl())
2138     return this;
2139 
2140   // Lookup doesn't work for destructors, so handle them separately.
2141   if (isa<CXXDestructorDecl>(this)) {
2142     CXXMethodDecl *MD = RD->getDestructor();
2143     if (MD) {
2144       if (recursivelyOverrides(MD, this))
2145         return MD;
2146       if (MayBeBase && recursivelyOverrides(this, MD))
2147         return MD;
2148     }
2149     return nullptr;
2150   }
2151 
2152   for (auto *ND : RD->lookup(getDeclName())) {
2153     auto *MD = dyn_cast<CXXMethodDecl>(ND);
2154     if (!MD)
2155       continue;
2156     if (recursivelyOverrides(MD, this))
2157       return MD;
2158     if (MayBeBase && recursivelyOverrides(this, MD))
2159       return MD;
2160   }
2161 
2162   return nullptr;
2163 }
2164 
2165 CXXMethodDecl *
2166 CXXMethodDecl::getCorrespondingMethodInClass(const CXXRecordDecl *RD,
2167                                              bool MayBeBase) {
2168   if (auto *MD = getCorrespondingMethodDeclaredInClass(RD, MayBeBase))
2169     return MD;
2170 
2171   llvm::SmallVector<CXXMethodDecl*, 4> FinalOverriders;
2172   auto AddFinalOverrider = [&](CXXMethodDecl *D) {
2173     // If this function is overridden by a candidate final overrider, it is not
2174     // a final overrider.
2175     for (CXXMethodDecl *OtherD : FinalOverriders) {
2176       if (declaresSameEntity(D, OtherD) || recursivelyOverrides(OtherD, D))
2177         return;
2178     }
2179 
2180     // Other candidate final overriders might be overridden by this function.
2181     llvm::erase_if(FinalOverriders, [&](CXXMethodDecl *OtherD) {
2182       return recursivelyOverrides(D, OtherD);
2183     });
2184 
2185     FinalOverriders.push_back(D);
2186   };
2187 
2188   for (const auto &I : RD->bases()) {
2189     const RecordType *RT = I.getType()->getAs<RecordType>();
2190     if (!RT)
2191       continue;
2192     const auto *Base = cast<CXXRecordDecl>(RT->getDecl());
2193     if (CXXMethodDecl *D = this->getCorrespondingMethodInClass(Base))
2194       AddFinalOverrider(D);
2195   }
2196 
2197   return FinalOverriders.size() == 1 ? FinalOverriders.front() : nullptr;
2198 }
2199 
2200 CXXMethodDecl *
2201 CXXMethodDecl::Create(ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2202                       const DeclarationNameInfo &NameInfo, QualType T,
2203                       TypeSourceInfo *TInfo, StorageClass SC, bool UsesFPIntrin,
2204                       bool isInline, ConstexprSpecKind ConstexprKind,
2205                       SourceLocation EndLocation,
2206                       Expr *TrailingRequiresClause) {
2207   return new (C, RD) CXXMethodDecl(
2208       CXXMethod, C, RD, StartLoc, NameInfo, T, TInfo, SC, UsesFPIntrin,
2209       isInline, ConstexprKind, EndLocation, TrailingRequiresClause);
2210 }
2211 
2212 CXXMethodDecl *CXXMethodDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2213   return new (C, ID) CXXMethodDecl(
2214       CXXMethod, C, nullptr, SourceLocation(), DeclarationNameInfo(),
2215       QualType(), nullptr, SC_None, false, false,
2216       ConstexprSpecKind::Unspecified, SourceLocation(), nullptr);
2217 }
2218 
2219 CXXMethodDecl *CXXMethodDecl::getDevirtualizedMethod(const Expr *Base,
2220                                                      bool IsAppleKext) {
2221   assert(isVirtual() && "this method is expected to be virtual");
2222 
2223   // When building with -fapple-kext, all calls must go through the vtable since
2224   // the kernel linker can do runtime patching of vtables.
2225   if (IsAppleKext)
2226     return nullptr;
2227 
2228   // If the member function is marked 'final', we know that it can't be
2229   // overridden and can therefore devirtualize it unless it's pure virtual.
2230   if (hasAttr<FinalAttr>())
2231     return isPure() ? nullptr : this;
2232 
2233   // If Base is unknown, we cannot devirtualize.
2234   if (!Base)
2235     return nullptr;
2236 
2237   // If the base expression (after skipping derived-to-base conversions) is a
2238   // class prvalue, then we can devirtualize.
2239   Base = Base->getBestDynamicClassTypeExpr();
2240   if (Base->isPRValue() && Base->getType()->isRecordType())
2241     return this;
2242 
2243   // If we don't even know what we would call, we can't devirtualize.
2244   const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType();
2245   if (!BestDynamicDecl)
2246     return nullptr;
2247 
2248   // There may be a method corresponding to MD in a derived class.
2249   CXXMethodDecl *DevirtualizedMethod =
2250       getCorrespondingMethodInClass(BestDynamicDecl);
2251 
2252   // If there final overrider in the dynamic type is ambiguous, we can't
2253   // devirtualize this call.
2254   if (!DevirtualizedMethod)
2255     return nullptr;
2256 
2257   // If that method is pure virtual, we can't devirtualize. If this code is
2258   // reached, the result would be UB, not a direct call to the derived class
2259   // function, and we can't assume the derived class function is defined.
2260   if (DevirtualizedMethod->isPure())
2261     return nullptr;
2262 
2263   // If that method is marked final, we can devirtualize it.
2264   if (DevirtualizedMethod->hasAttr<FinalAttr>())
2265     return DevirtualizedMethod;
2266 
2267   // Similarly, if the class itself or its destructor is marked 'final',
2268   // the class can't be derived from and we can therefore devirtualize the
2269   // member function call.
2270   if (BestDynamicDecl->isEffectivelyFinal())
2271     return DevirtualizedMethod;
2272 
2273   if (const auto *DRE = dyn_cast<DeclRefExpr>(Base)) {
2274     if (const auto *VD = dyn_cast<VarDecl>(DRE->getDecl()))
2275       if (VD->getType()->isRecordType())
2276         // This is a record decl. We know the type and can devirtualize it.
2277         return DevirtualizedMethod;
2278 
2279     return nullptr;
2280   }
2281 
2282   // We can devirtualize calls on an object accessed by a class member access
2283   // expression, since by C++11 [basic.life]p6 we know that it can't refer to
2284   // a derived class object constructed in the same location.
2285   if (const auto *ME = dyn_cast<MemberExpr>(Base)) {
2286     const ValueDecl *VD = ME->getMemberDecl();
2287     return VD->getType()->isRecordType() ? DevirtualizedMethod : nullptr;
2288   }
2289 
2290   // Likewise for calls on an object accessed by a (non-reference) pointer to
2291   // member access.
2292   if (auto *BO = dyn_cast<BinaryOperator>(Base)) {
2293     if (BO->isPtrMemOp()) {
2294       auto *MPT = BO->getRHS()->getType()->castAs<MemberPointerType>();
2295       if (MPT->getPointeeType()->isRecordType())
2296         return DevirtualizedMethod;
2297     }
2298   }
2299 
2300   // We can't devirtualize the call.
2301   return nullptr;
2302 }
2303 
2304 bool CXXMethodDecl::isUsualDeallocationFunction(
2305     SmallVectorImpl<const FunctionDecl *> &PreventedBy) const {
2306   assert(PreventedBy.empty() && "PreventedBy is expected to be empty");
2307   if (getOverloadedOperator() != OO_Delete &&
2308       getOverloadedOperator() != OO_Array_Delete)
2309     return false;
2310 
2311   // C++ [basic.stc.dynamic.deallocation]p2:
2312   //   A template instance is never a usual deallocation function,
2313   //   regardless of its signature.
2314   if (getPrimaryTemplate())
2315     return false;
2316 
2317   // C++ [basic.stc.dynamic.deallocation]p2:
2318   //   If a class T has a member deallocation function named operator delete
2319   //   with exactly one parameter, then that function is a usual (non-placement)
2320   //   deallocation function. [...]
2321   if (getNumParams() == 1)
2322     return true;
2323   unsigned UsualParams = 1;
2324 
2325   // C++ P0722:
2326   //   A destroying operator delete is a usual deallocation function if
2327   //   removing the std::destroying_delete_t parameter and changing the
2328   //   first parameter type from T* to void* results in the signature of
2329   //   a usual deallocation function.
2330   if (isDestroyingOperatorDelete())
2331     ++UsualParams;
2332 
2333   // C++ <=14 [basic.stc.dynamic.deallocation]p2:
2334   //   [...] If class T does not declare such an operator delete but does
2335   //   declare a member deallocation function named operator delete with
2336   //   exactly two parameters, the second of which has type std::size_t (18.1),
2337   //   then this function is a usual deallocation function.
2338   //
2339   // C++17 says a usual deallocation function is one with the signature
2340   //   (void* [, size_t] [, std::align_val_t] [, ...])
2341   // and all such functions are usual deallocation functions. It's not clear
2342   // that allowing varargs functions was intentional.
2343   ASTContext &Context = getASTContext();
2344   if (UsualParams < getNumParams() &&
2345       Context.hasSameUnqualifiedType(getParamDecl(UsualParams)->getType(),
2346                                      Context.getSizeType()))
2347     ++UsualParams;
2348 
2349   if (UsualParams < getNumParams() &&
2350       getParamDecl(UsualParams)->getType()->isAlignValT())
2351     ++UsualParams;
2352 
2353   if (UsualParams != getNumParams())
2354     return false;
2355 
2356   // In C++17 onwards, all potential usual deallocation functions are actual
2357   // usual deallocation functions. Honor this behavior when post-C++14
2358   // deallocation functions are offered as extensions too.
2359   // FIXME(EricWF): Destroying Delete should be a language option. How do we
2360   // handle when destroying delete is used prior to C++17?
2361   if (Context.getLangOpts().CPlusPlus17 ||
2362       Context.getLangOpts().AlignedAllocation ||
2363       isDestroyingOperatorDelete())
2364     return true;
2365 
2366   // This function is a usual deallocation function if there are no
2367   // single-parameter deallocation functions of the same kind.
2368   DeclContext::lookup_result R = getDeclContext()->lookup(getDeclName());
2369   bool Result = true;
2370   for (const auto *D : R) {
2371     if (const auto *FD = dyn_cast<FunctionDecl>(D)) {
2372       if (FD->getNumParams() == 1) {
2373         PreventedBy.push_back(FD);
2374         Result = false;
2375       }
2376     }
2377   }
2378   return Result;
2379 }
2380 
2381 bool CXXMethodDecl::isCopyAssignmentOperator() const {
2382   // C++0x [class.copy]p17:
2383   //  A user-declared copy assignment operator X::operator= is a non-static
2384   //  non-template member function of class X with exactly one parameter of
2385   //  type X, X&, const X&, volatile X& or const volatile X&.
2386   if (/*operator=*/getOverloadedOperator() != OO_Equal ||
2387       /*non-static*/ isStatic() ||
2388       /*non-template*/getPrimaryTemplate() || getDescribedFunctionTemplate() ||
2389       getNumParams() != 1)
2390     return false;
2391 
2392   QualType ParamType = getParamDecl(0)->getType();
2393   if (const auto *Ref = ParamType->getAs<LValueReferenceType>())
2394     ParamType = Ref->getPointeeType();
2395 
2396   ASTContext &Context = getASTContext();
2397   QualType ClassType
2398     = Context.getCanonicalType(Context.getTypeDeclType(getParent()));
2399   return Context.hasSameUnqualifiedType(ClassType, ParamType);
2400 }
2401 
2402 bool CXXMethodDecl::isMoveAssignmentOperator() const {
2403   // C++0x [class.copy]p19:
2404   //  A user-declared move assignment operator X::operator= is a non-static
2405   //  non-template member function of class X with exactly one parameter of type
2406   //  X&&, const X&&, volatile X&&, or const volatile X&&.
2407   if (getOverloadedOperator() != OO_Equal || isStatic() ||
2408       getPrimaryTemplate() || getDescribedFunctionTemplate() ||
2409       getNumParams() != 1)
2410     return false;
2411 
2412   QualType ParamType = getParamDecl(0)->getType();
2413   if (!ParamType->isRValueReferenceType())
2414     return false;
2415   ParamType = ParamType->getPointeeType();
2416 
2417   ASTContext &Context = getASTContext();
2418   QualType ClassType
2419     = Context.getCanonicalType(Context.getTypeDeclType(getParent()));
2420   return Context.hasSameUnqualifiedType(ClassType, ParamType);
2421 }
2422 
2423 void CXXMethodDecl::addOverriddenMethod(const CXXMethodDecl *MD) {
2424   assert(MD->isCanonicalDecl() && "Method is not canonical!");
2425   assert(!MD->getParent()->isDependentContext() &&
2426          "Can't add an overridden method to a class template!");
2427   assert(MD->isVirtual() && "Method is not virtual!");
2428 
2429   getASTContext().addOverriddenMethod(this, MD);
2430 }
2431 
2432 CXXMethodDecl::method_iterator CXXMethodDecl::begin_overridden_methods() const {
2433   if (isa<CXXConstructorDecl>(this)) return nullptr;
2434   return getASTContext().overridden_methods_begin(this);
2435 }
2436 
2437 CXXMethodDecl::method_iterator CXXMethodDecl::end_overridden_methods() const {
2438   if (isa<CXXConstructorDecl>(this)) return nullptr;
2439   return getASTContext().overridden_methods_end(this);
2440 }
2441 
2442 unsigned CXXMethodDecl::size_overridden_methods() const {
2443   if (isa<CXXConstructorDecl>(this)) return 0;
2444   return getASTContext().overridden_methods_size(this);
2445 }
2446 
2447 CXXMethodDecl::overridden_method_range
2448 CXXMethodDecl::overridden_methods() const {
2449   if (isa<CXXConstructorDecl>(this))
2450     return overridden_method_range(nullptr, nullptr);
2451   return getASTContext().overridden_methods(this);
2452 }
2453 
2454 static QualType getThisObjectType(ASTContext &C, const FunctionProtoType *FPT,
2455                                   const CXXRecordDecl *Decl) {
2456   QualType ClassTy = C.getTypeDeclType(Decl);
2457   return C.getQualifiedType(ClassTy, FPT->getMethodQuals());
2458 }
2459 
2460 QualType CXXMethodDecl::getThisType(const FunctionProtoType *FPT,
2461                                     const CXXRecordDecl *Decl) {
2462   ASTContext &C = Decl->getASTContext();
2463   QualType ObjectTy = ::getThisObjectType(C, FPT, Decl);
2464   return C.getPointerType(ObjectTy);
2465 }
2466 
2467 QualType CXXMethodDecl::getThisObjectType(const FunctionProtoType *FPT,
2468                                           const CXXRecordDecl *Decl) {
2469   ASTContext &C = Decl->getASTContext();
2470   return ::getThisObjectType(C, FPT, Decl);
2471 }
2472 
2473 QualType CXXMethodDecl::getThisType() const {
2474   // C++ 9.3.2p1: The type of this in a member function of a class X is X*.
2475   // If the member function is declared const, the type of this is const X*,
2476   // if the member function is declared volatile, the type of this is
2477   // volatile X*, and if the member function is declared const volatile,
2478   // the type of this is const volatile X*.
2479   assert(isInstance() && "No 'this' for static methods!");
2480   return CXXMethodDecl::getThisType(getType()->castAs<FunctionProtoType>(),
2481                                     getParent());
2482 }
2483 
2484 QualType CXXMethodDecl::getThisObjectType() const {
2485   // Ditto getThisType.
2486   assert(isInstance() && "No 'this' for static methods!");
2487   return CXXMethodDecl::getThisObjectType(
2488       getType()->castAs<FunctionProtoType>(), getParent());
2489 }
2490 
2491 bool CXXMethodDecl::hasInlineBody() const {
2492   // If this function is a template instantiation, look at the template from
2493   // which it was instantiated.
2494   const FunctionDecl *CheckFn = getTemplateInstantiationPattern();
2495   if (!CheckFn)
2496     CheckFn = this;
2497 
2498   const FunctionDecl *fn;
2499   return CheckFn->isDefined(fn) && !fn->isOutOfLine() &&
2500          (fn->doesThisDeclarationHaveABody() || fn->willHaveBody());
2501 }
2502 
2503 bool CXXMethodDecl::isLambdaStaticInvoker() const {
2504   const CXXRecordDecl *P = getParent();
2505   return P->isLambda() && getDeclName().isIdentifier() &&
2506          getName() == getLambdaStaticInvokerName();
2507 }
2508 
2509 CXXCtorInitializer::CXXCtorInitializer(ASTContext &Context,
2510                                        TypeSourceInfo *TInfo, bool IsVirtual,
2511                                        SourceLocation L, Expr *Init,
2512                                        SourceLocation R,
2513                                        SourceLocation EllipsisLoc)
2514     : Initializee(TInfo), Init(Init), MemberOrEllipsisLocation(EllipsisLoc),
2515       LParenLoc(L), RParenLoc(R), IsDelegating(false), IsVirtual(IsVirtual),
2516       IsWritten(false), SourceOrder(0) {}
2517 
2518 CXXCtorInitializer::CXXCtorInitializer(ASTContext &Context, FieldDecl *Member,
2519                                        SourceLocation MemberLoc,
2520                                        SourceLocation L, Expr *Init,
2521                                        SourceLocation R)
2522     : Initializee(Member), Init(Init), MemberOrEllipsisLocation(MemberLoc),
2523       LParenLoc(L), RParenLoc(R), IsDelegating(false), IsVirtual(false),
2524       IsWritten(false), SourceOrder(0) {}
2525 
2526 CXXCtorInitializer::CXXCtorInitializer(ASTContext &Context,
2527                                        IndirectFieldDecl *Member,
2528                                        SourceLocation MemberLoc,
2529                                        SourceLocation L, Expr *Init,
2530                                        SourceLocation R)
2531     : Initializee(Member), Init(Init), MemberOrEllipsisLocation(MemberLoc),
2532       LParenLoc(L), RParenLoc(R), IsDelegating(false), IsVirtual(false),
2533       IsWritten(false), SourceOrder(0) {}
2534 
2535 CXXCtorInitializer::CXXCtorInitializer(ASTContext &Context,
2536                                        TypeSourceInfo *TInfo,
2537                                        SourceLocation L, Expr *Init,
2538                                        SourceLocation R)
2539     : Initializee(TInfo), Init(Init), LParenLoc(L), RParenLoc(R),
2540       IsDelegating(true), IsVirtual(false), IsWritten(false), SourceOrder(0) {}
2541 
2542 int64_t CXXCtorInitializer::getID(const ASTContext &Context) const {
2543   return Context.getAllocator()
2544                 .identifyKnownAlignedObject<CXXCtorInitializer>(this);
2545 }
2546 
2547 TypeLoc CXXCtorInitializer::getBaseClassLoc() const {
2548   if (isBaseInitializer())
2549     return Initializee.get<TypeSourceInfo*>()->getTypeLoc();
2550   else
2551     return {};
2552 }
2553 
2554 const Type *CXXCtorInitializer::getBaseClass() const {
2555   if (isBaseInitializer())
2556     return Initializee.get<TypeSourceInfo*>()->getType().getTypePtr();
2557   else
2558     return nullptr;
2559 }
2560 
2561 SourceLocation CXXCtorInitializer::getSourceLocation() const {
2562   if (isInClassMemberInitializer())
2563     return getAnyMember()->getLocation();
2564 
2565   if (isAnyMemberInitializer())
2566     return getMemberLocation();
2567 
2568   if (const auto *TSInfo = Initializee.get<TypeSourceInfo *>())
2569     return TSInfo->getTypeLoc().getLocalSourceRange().getBegin();
2570 
2571   return {};
2572 }
2573 
2574 SourceRange CXXCtorInitializer::getSourceRange() const {
2575   if (isInClassMemberInitializer()) {
2576     FieldDecl *D = getAnyMember();
2577     if (Expr *I = D->getInClassInitializer())
2578       return I->getSourceRange();
2579     return {};
2580   }
2581 
2582   return SourceRange(getSourceLocation(), getRParenLoc());
2583 }
2584 
2585 CXXConstructorDecl::CXXConstructorDecl(
2586     ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2587     const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2588     ExplicitSpecifier ES, bool UsesFPIntrin, bool isInline,
2589     bool isImplicitlyDeclared, ConstexprSpecKind ConstexprKind,
2590     InheritedConstructor Inherited, Expr *TrailingRequiresClause)
2591     : CXXMethodDecl(CXXConstructor, C, RD, StartLoc, NameInfo, T, TInfo,
2592                     SC_None, UsesFPIntrin, isInline, ConstexprKind,
2593                     SourceLocation(), TrailingRequiresClause) {
2594   setNumCtorInitializers(0);
2595   setInheritingConstructor(static_cast<bool>(Inherited));
2596   setImplicit(isImplicitlyDeclared);
2597   CXXConstructorDeclBits.HasTrailingExplicitSpecifier = ES.getExpr() ? 1 : 0;
2598   if (Inherited)
2599     *getTrailingObjects<InheritedConstructor>() = Inherited;
2600   setExplicitSpecifier(ES);
2601 }
2602 
2603 void CXXConstructorDecl::anchor() {}
2604 
2605 CXXConstructorDecl *CXXConstructorDecl::CreateDeserialized(ASTContext &C,
2606                                                            unsigned ID,
2607                                                            uint64_t AllocKind) {
2608   bool hasTrailingExplicit = static_cast<bool>(AllocKind & TAKHasTailExplicit);
2609   bool isInheritingConstructor =
2610       static_cast<bool>(AllocKind & TAKInheritsConstructor);
2611   unsigned Extra =
2612       additionalSizeToAlloc<InheritedConstructor, ExplicitSpecifier>(
2613           isInheritingConstructor, hasTrailingExplicit);
2614   auto *Result = new (C, ID, Extra) CXXConstructorDecl(
2615       C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(), nullptr,
2616       ExplicitSpecifier(), false, false, false, ConstexprSpecKind::Unspecified,
2617       InheritedConstructor(), nullptr);
2618   Result->setInheritingConstructor(isInheritingConstructor);
2619   Result->CXXConstructorDeclBits.HasTrailingExplicitSpecifier =
2620       hasTrailingExplicit;
2621   Result->setExplicitSpecifier(ExplicitSpecifier());
2622   return Result;
2623 }
2624 
2625 CXXConstructorDecl *CXXConstructorDecl::Create(
2626     ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2627     const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2628     ExplicitSpecifier ES, bool UsesFPIntrin, bool isInline,
2629     bool isImplicitlyDeclared, ConstexprSpecKind ConstexprKind,
2630     InheritedConstructor Inherited, Expr *TrailingRequiresClause) {
2631   assert(NameInfo.getName().getNameKind()
2632          == DeclarationName::CXXConstructorName &&
2633          "Name must refer to a constructor");
2634   unsigned Extra =
2635       additionalSizeToAlloc<InheritedConstructor, ExplicitSpecifier>(
2636           Inherited ? 1 : 0, ES.getExpr() ? 1 : 0);
2637   return new (C, RD, Extra) CXXConstructorDecl(
2638       C, RD, StartLoc, NameInfo, T, TInfo, ES, UsesFPIntrin, isInline,
2639       isImplicitlyDeclared, ConstexprKind, Inherited, TrailingRequiresClause);
2640 }
2641 
2642 CXXConstructorDecl::init_const_iterator CXXConstructorDecl::init_begin() const {
2643   return CtorInitializers.get(getASTContext().getExternalSource());
2644 }
2645 
2646 CXXConstructorDecl *CXXConstructorDecl::getTargetConstructor() const {
2647   assert(isDelegatingConstructor() && "Not a delegating constructor!");
2648   Expr *E = (*init_begin())->getInit()->IgnoreImplicit();
2649   if (const auto *Construct = dyn_cast<CXXConstructExpr>(E))
2650     return Construct->getConstructor();
2651 
2652   return nullptr;
2653 }
2654 
2655 bool CXXConstructorDecl::isDefaultConstructor() const {
2656   // C++ [class.default.ctor]p1:
2657   //   A default constructor for a class X is a constructor of class X for
2658   //   which each parameter that is not a function parameter pack has a default
2659   //   argument (including the case of a constructor with no parameters)
2660   return getMinRequiredArguments() == 0;
2661 }
2662 
2663 bool
2664 CXXConstructorDecl::isCopyConstructor(unsigned &TypeQuals) const {
2665   return isCopyOrMoveConstructor(TypeQuals) &&
2666          getParamDecl(0)->getType()->isLValueReferenceType();
2667 }
2668 
2669 bool CXXConstructorDecl::isMoveConstructor(unsigned &TypeQuals) const {
2670   return isCopyOrMoveConstructor(TypeQuals) &&
2671          getParamDecl(0)->getType()->isRValueReferenceType();
2672 }
2673 
2674 /// Determine whether this is a copy or move constructor.
2675 bool CXXConstructorDecl::isCopyOrMoveConstructor(unsigned &TypeQuals) const {
2676   // C++ [class.copy]p2:
2677   //   A non-template constructor for class X is a copy constructor
2678   //   if its first parameter is of type X&, const X&, volatile X& or
2679   //   const volatile X&, and either there are no other parameters
2680   //   or else all other parameters have default arguments (8.3.6).
2681   // C++0x [class.copy]p3:
2682   //   A non-template constructor for class X is a move constructor if its
2683   //   first parameter is of type X&&, const X&&, volatile X&&, or
2684   //   const volatile X&&, and either there are no other parameters or else
2685   //   all other parameters have default arguments.
2686   if (!hasOneParamOrDefaultArgs() || getPrimaryTemplate() != nullptr ||
2687       getDescribedFunctionTemplate() != nullptr)
2688     return false;
2689 
2690   const ParmVarDecl *Param = getParamDecl(0);
2691 
2692   // Do we have a reference type?
2693   const auto *ParamRefType = Param->getType()->getAs<ReferenceType>();
2694   if (!ParamRefType)
2695     return false;
2696 
2697   // Is it a reference to our class type?
2698   ASTContext &Context = getASTContext();
2699 
2700   CanQualType PointeeType
2701     = Context.getCanonicalType(ParamRefType->getPointeeType());
2702   CanQualType ClassTy
2703     = Context.getCanonicalType(Context.getTagDeclType(getParent()));
2704   if (PointeeType.getUnqualifiedType() != ClassTy)
2705     return false;
2706 
2707   // FIXME: other qualifiers?
2708 
2709   // We have a copy or move constructor.
2710   TypeQuals = PointeeType.getCVRQualifiers();
2711   return true;
2712 }
2713 
2714 bool CXXConstructorDecl::isConvertingConstructor(bool AllowExplicit) const {
2715   // C++ [class.conv.ctor]p1:
2716   //   A constructor declared without the function-specifier explicit
2717   //   that can be called with a single parameter specifies a
2718   //   conversion from the type of its first parameter to the type of
2719   //   its class. Such a constructor is called a converting
2720   //   constructor.
2721   if (isExplicit() && !AllowExplicit)
2722     return false;
2723 
2724   // FIXME: This has nothing to do with the definition of converting
2725   // constructor, but is convenient for how we use this function in overload
2726   // resolution.
2727   return getNumParams() == 0
2728              ? getType()->castAs<FunctionProtoType>()->isVariadic()
2729              : getMinRequiredArguments() <= 1;
2730 }
2731 
2732 bool CXXConstructorDecl::isSpecializationCopyingObject() const {
2733   if (!hasOneParamOrDefaultArgs() || getDescribedFunctionTemplate() != nullptr)
2734     return false;
2735 
2736   const ParmVarDecl *Param = getParamDecl(0);
2737 
2738   ASTContext &Context = getASTContext();
2739   CanQualType ParamType = Context.getCanonicalType(Param->getType());
2740 
2741   // Is it the same as our class type?
2742   CanQualType ClassTy
2743     = Context.getCanonicalType(Context.getTagDeclType(getParent()));
2744   if (ParamType.getUnqualifiedType() != ClassTy)
2745     return false;
2746 
2747   return true;
2748 }
2749 
2750 void CXXDestructorDecl::anchor() {}
2751 
2752 CXXDestructorDecl *
2753 CXXDestructorDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2754   return new (C, ID) CXXDestructorDecl(
2755       C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(), nullptr,
2756       false, false, false, ConstexprSpecKind::Unspecified, nullptr);
2757 }
2758 
2759 CXXDestructorDecl *CXXDestructorDecl::Create(
2760     ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2761     const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2762     bool UsesFPIntrin, bool isInline, bool isImplicitlyDeclared,
2763     ConstexprSpecKind ConstexprKind, Expr *TrailingRequiresClause) {
2764   assert(NameInfo.getName().getNameKind()
2765          == DeclarationName::CXXDestructorName &&
2766          "Name must refer to a destructor");
2767   return new (C, RD) CXXDestructorDecl(
2768       C, RD, StartLoc, NameInfo, T, TInfo, UsesFPIntrin, isInline,
2769       isImplicitlyDeclared, ConstexprKind, TrailingRequiresClause);
2770 }
2771 
2772 void CXXDestructorDecl::setOperatorDelete(FunctionDecl *OD, Expr *ThisArg) {
2773   auto *First = cast<CXXDestructorDecl>(getFirstDecl());
2774   if (OD && !First->OperatorDelete) {
2775     First->OperatorDelete = OD;
2776     First->OperatorDeleteThisArg = ThisArg;
2777     if (auto *L = getASTMutationListener())
2778       L->ResolvedOperatorDelete(First, OD, ThisArg);
2779   }
2780 }
2781 
2782 void CXXConversionDecl::anchor() {}
2783 
2784 CXXConversionDecl *
2785 CXXConversionDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2786   return new (C, ID) CXXConversionDecl(
2787       C, nullptr, SourceLocation(), DeclarationNameInfo(), QualType(), nullptr,
2788       false, false, ExplicitSpecifier(), ConstexprSpecKind::Unspecified,
2789       SourceLocation(), nullptr);
2790 }
2791 
2792 CXXConversionDecl *CXXConversionDecl::Create(
2793     ASTContext &C, CXXRecordDecl *RD, SourceLocation StartLoc,
2794     const DeclarationNameInfo &NameInfo, QualType T, TypeSourceInfo *TInfo,
2795     bool UsesFPIntrin, bool isInline, ExplicitSpecifier ES,
2796     ConstexprSpecKind ConstexprKind, SourceLocation EndLocation,
2797     Expr *TrailingRequiresClause) {
2798   assert(NameInfo.getName().getNameKind()
2799          == DeclarationName::CXXConversionFunctionName &&
2800          "Name must refer to a conversion function");
2801   return new (C, RD) CXXConversionDecl(
2802       C, RD, StartLoc, NameInfo, T, TInfo, UsesFPIntrin, isInline, ES,
2803       ConstexprKind, EndLocation, TrailingRequiresClause);
2804 }
2805 
2806 bool CXXConversionDecl::isLambdaToBlockPointerConversion() const {
2807   return isImplicit() && getParent()->isLambda() &&
2808          getConversionType()->isBlockPointerType();
2809 }
2810 
2811 LinkageSpecDecl::LinkageSpecDecl(DeclContext *DC, SourceLocation ExternLoc,
2812                                  SourceLocation LangLoc, LanguageIDs lang,
2813                                  bool HasBraces)
2814     : Decl(LinkageSpec, DC, LangLoc), DeclContext(LinkageSpec),
2815       ExternLoc(ExternLoc), RBraceLoc(SourceLocation()) {
2816   setLanguage(lang);
2817   LinkageSpecDeclBits.HasBraces = HasBraces;
2818 }
2819 
2820 void LinkageSpecDecl::anchor() {}
2821 
2822 LinkageSpecDecl *LinkageSpecDecl::Create(ASTContext &C,
2823                                          DeclContext *DC,
2824                                          SourceLocation ExternLoc,
2825                                          SourceLocation LangLoc,
2826                                          LanguageIDs Lang,
2827                                          bool HasBraces) {
2828   return new (C, DC) LinkageSpecDecl(DC, ExternLoc, LangLoc, Lang, HasBraces);
2829 }
2830 
2831 LinkageSpecDecl *LinkageSpecDecl::CreateDeserialized(ASTContext &C,
2832                                                      unsigned ID) {
2833   return new (C, ID) LinkageSpecDecl(nullptr, SourceLocation(),
2834                                      SourceLocation(), lang_c, false);
2835 }
2836 
2837 void UsingDirectiveDecl::anchor() {}
2838 
2839 UsingDirectiveDecl *UsingDirectiveDecl::Create(ASTContext &C, DeclContext *DC,
2840                                                SourceLocation L,
2841                                                SourceLocation NamespaceLoc,
2842                                            NestedNameSpecifierLoc QualifierLoc,
2843                                                SourceLocation IdentLoc,
2844                                                NamedDecl *Used,
2845                                                DeclContext *CommonAncestor) {
2846   if (auto *NS = dyn_cast_or_null<NamespaceDecl>(Used))
2847     Used = NS->getOriginalNamespace();
2848   return new (C, DC) UsingDirectiveDecl(DC, L, NamespaceLoc, QualifierLoc,
2849                                         IdentLoc, Used, CommonAncestor);
2850 }
2851 
2852 UsingDirectiveDecl *UsingDirectiveDecl::CreateDeserialized(ASTContext &C,
2853                                                            unsigned ID) {
2854   return new (C, ID) UsingDirectiveDecl(nullptr, SourceLocation(),
2855                                         SourceLocation(),
2856                                         NestedNameSpecifierLoc(),
2857                                         SourceLocation(), nullptr, nullptr);
2858 }
2859 
2860 NamespaceDecl *UsingDirectiveDecl::getNominatedNamespace() {
2861   if (auto *NA = dyn_cast_or_null<NamespaceAliasDecl>(NominatedNamespace))
2862     return NA->getNamespace();
2863   return cast_or_null<NamespaceDecl>(NominatedNamespace);
2864 }
2865 
2866 NamespaceDecl::NamespaceDecl(ASTContext &C, DeclContext *DC, bool Inline,
2867                              SourceLocation StartLoc, SourceLocation IdLoc,
2868                              IdentifierInfo *Id, NamespaceDecl *PrevDecl)
2869     : NamedDecl(Namespace, DC, IdLoc, Id), DeclContext(Namespace),
2870       redeclarable_base(C), LocStart(StartLoc),
2871       AnonOrFirstNamespaceAndInline(nullptr, Inline) {
2872   setPreviousDecl(PrevDecl);
2873 
2874   if (PrevDecl)
2875     AnonOrFirstNamespaceAndInline.setPointer(PrevDecl->getOriginalNamespace());
2876 }
2877 
2878 NamespaceDecl *NamespaceDecl::Create(ASTContext &C, DeclContext *DC,
2879                                      bool Inline, SourceLocation StartLoc,
2880                                      SourceLocation IdLoc, IdentifierInfo *Id,
2881                                      NamespaceDecl *PrevDecl) {
2882   return new (C, DC) NamespaceDecl(C, DC, Inline, StartLoc, IdLoc, Id,
2883                                    PrevDecl);
2884 }
2885 
2886 NamespaceDecl *NamespaceDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2887   return new (C, ID) NamespaceDecl(C, nullptr, false, SourceLocation(),
2888                                    SourceLocation(), nullptr, nullptr);
2889 }
2890 
2891 NamespaceDecl *NamespaceDecl::getOriginalNamespace() {
2892   if (isFirstDecl())
2893     return this;
2894 
2895   return AnonOrFirstNamespaceAndInline.getPointer();
2896 }
2897 
2898 const NamespaceDecl *NamespaceDecl::getOriginalNamespace() const {
2899   if (isFirstDecl())
2900     return this;
2901 
2902   return AnonOrFirstNamespaceAndInline.getPointer();
2903 }
2904 
2905 bool NamespaceDecl::isOriginalNamespace() const { return isFirstDecl(); }
2906 
2907 NamespaceDecl *NamespaceDecl::getNextRedeclarationImpl() {
2908   return getNextRedeclaration();
2909 }
2910 
2911 NamespaceDecl *NamespaceDecl::getPreviousDeclImpl() {
2912   return getPreviousDecl();
2913 }
2914 
2915 NamespaceDecl *NamespaceDecl::getMostRecentDeclImpl() {
2916   return getMostRecentDecl();
2917 }
2918 
2919 void NamespaceAliasDecl::anchor() {}
2920 
2921 NamespaceAliasDecl *NamespaceAliasDecl::getNextRedeclarationImpl() {
2922   return getNextRedeclaration();
2923 }
2924 
2925 NamespaceAliasDecl *NamespaceAliasDecl::getPreviousDeclImpl() {
2926   return getPreviousDecl();
2927 }
2928 
2929 NamespaceAliasDecl *NamespaceAliasDecl::getMostRecentDeclImpl() {
2930   return getMostRecentDecl();
2931 }
2932 
2933 NamespaceAliasDecl *NamespaceAliasDecl::Create(ASTContext &C, DeclContext *DC,
2934                                                SourceLocation UsingLoc,
2935                                                SourceLocation AliasLoc,
2936                                                IdentifierInfo *Alias,
2937                                            NestedNameSpecifierLoc QualifierLoc,
2938                                                SourceLocation IdentLoc,
2939                                                NamedDecl *Namespace) {
2940   // FIXME: Preserve the aliased namespace as written.
2941   if (auto *NS = dyn_cast_or_null<NamespaceDecl>(Namespace))
2942     Namespace = NS->getOriginalNamespace();
2943   return new (C, DC) NamespaceAliasDecl(C, DC, UsingLoc, AliasLoc, Alias,
2944                                         QualifierLoc, IdentLoc, Namespace);
2945 }
2946 
2947 NamespaceAliasDecl *
2948 NamespaceAliasDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
2949   return new (C, ID) NamespaceAliasDecl(C, nullptr, SourceLocation(),
2950                                         SourceLocation(), nullptr,
2951                                         NestedNameSpecifierLoc(),
2952                                         SourceLocation(), nullptr);
2953 }
2954 
2955 void LifetimeExtendedTemporaryDecl::anchor() {}
2956 
2957 /// Retrieve the storage duration for the materialized temporary.
2958 StorageDuration LifetimeExtendedTemporaryDecl::getStorageDuration() const {
2959   const ValueDecl *ExtendingDecl = getExtendingDecl();
2960   if (!ExtendingDecl)
2961     return SD_FullExpression;
2962   // FIXME: This is not necessarily correct for a temporary materialized
2963   // within a default initializer.
2964   if (isa<FieldDecl>(ExtendingDecl))
2965     return SD_Automatic;
2966   // FIXME: This only works because storage class specifiers are not allowed
2967   // on decomposition declarations.
2968   if (isa<BindingDecl>(ExtendingDecl))
2969     return ExtendingDecl->getDeclContext()->isFunctionOrMethod() ? SD_Automatic
2970                                                                  : SD_Static;
2971   return cast<VarDecl>(ExtendingDecl)->getStorageDuration();
2972 }
2973 
2974 APValue *LifetimeExtendedTemporaryDecl::getOrCreateValue(bool MayCreate) const {
2975   assert(getStorageDuration() == SD_Static &&
2976          "don't need to cache the computed value for this temporary");
2977   if (MayCreate && !Value) {
2978     Value = (new (getASTContext()) APValue);
2979     getASTContext().addDestruction(Value);
2980   }
2981   assert(Value && "may not be null");
2982   return Value;
2983 }
2984 
2985 void UsingShadowDecl::anchor() {}
2986 
2987 UsingShadowDecl::UsingShadowDecl(Kind K, ASTContext &C, DeclContext *DC,
2988                                  SourceLocation Loc, DeclarationName Name,
2989                                  BaseUsingDecl *Introducer, NamedDecl *Target)
2990     : NamedDecl(K, DC, Loc, Name), redeclarable_base(C),
2991       UsingOrNextShadow(Introducer) {
2992   if (Target) {
2993     assert(!isa<UsingShadowDecl>(Target));
2994     setTargetDecl(Target);
2995   }
2996   setImplicit();
2997 }
2998 
2999 UsingShadowDecl::UsingShadowDecl(Kind K, ASTContext &C, EmptyShell Empty)
3000     : NamedDecl(K, nullptr, SourceLocation(), DeclarationName()),
3001       redeclarable_base(C) {}
3002 
3003 UsingShadowDecl *
3004 UsingShadowDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3005   return new (C, ID) UsingShadowDecl(UsingShadow, C, EmptyShell());
3006 }
3007 
3008 BaseUsingDecl *UsingShadowDecl::getIntroducer() const {
3009   const UsingShadowDecl *Shadow = this;
3010   while (const auto *NextShadow =
3011              dyn_cast<UsingShadowDecl>(Shadow->UsingOrNextShadow))
3012     Shadow = NextShadow;
3013   return cast<BaseUsingDecl>(Shadow->UsingOrNextShadow);
3014 }
3015 
3016 void ConstructorUsingShadowDecl::anchor() {}
3017 
3018 ConstructorUsingShadowDecl *
3019 ConstructorUsingShadowDecl::Create(ASTContext &C, DeclContext *DC,
3020                                    SourceLocation Loc, UsingDecl *Using,
3021                                    NamedDecl *Target, bool IsVirtual) {
3022   return new (C, DC) ConstructorUsingShadowDecl(C, DC, Loc, Using, Target,
3023                                                 IsVirtual);
3024 }
3025 
3026 ConstructorUsingShadowDecl *
3027 ConstructorUsingShadowDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3028   return new (C, ID) ConstructorUsingShadowDecl(C, EmptyShell());
3029 }
3030 
3031 CXXRecordDecl *ConstructorUsingShadowDecl::getNominatedBaseClass() const {
3032   return getIntroducer()->getQualifier()->getAsRecordDecl();
3033 }
3034 
3035 void BaseUsingDecl::anchor() {}
3036 
3037 void BaseUsingDecl::addShadowDecl(UsingShadowDecl *S) {
3038   assert(!llvm::is_contained(shadows(), S) && "declaration already in set");
3039   assert(S->getIntroducer() == this);
3040 
3041   if (FirstUsingShadow.getPointer())
3042     S->UsingOrNextShadow = FirstUsingShadow.getPointer();
3043   FirstUsingShadow.setPointer(S);
3044 }
3045 
3046 void BaseUsingDecl::removeShadowDecl(UsingShadowDecl *S) {
3047   assert(llvm::is_contained(shadows(), S) && "declaration not in set");
3048   assert(S->getIntroducer() == this);
3049 
3050   // Remove S from the shadow decl chain. This is O(n) but hopefully rare.
3051 
3052   if (FirstUsingShadow.getPointer() == S) {
3053     FirstUsingShadow.setPointer(
3054       dyn_cast<UsingShadowDecl>(S->UsingOrNextShadow));
3055     S->UsingOrNextShadow = this;
3056     return;
3057   }
3058 
3059   UsingShadowDecl *Prev = FirstUsingShadow.getPointer();
3060   while (Prev->UsingOrNextShadow != S)
3061     Prev = cast<UsingShadowDecl>(Prev->UsingOrNextShadow);
3062   Prev->UsingOrNextShadow = S->UsingOrNextShadow;
3063   S->UsingOrNextShadow = this;
3064 }
3065 
3066 void UsingDecl::anchor() {}
3067 
3068 UsingDecl *UsingDecl::Create(ASTContext &C, DeclContext *DC, SourceLocation UL,
3069                              NestedNameSpecifierLoc QualifierLoc,
3070                              const DeclarationNameInfo &NameInfo,
3071                              bool HasTypename) {
3072   return new (C, DC) UsingDecl(DC, UL, QualifierLoc, NameInfo, HasTypename);
3073 }
3074 
3075 UsingDecl *UsingDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3076   return new (C, ID) UsingDecl(nullptr, SourceLocation(),
3077                                NestedNameSpecifierLoc(), DeclarationNameInfo(),
3078                                false);
3079 }
3080 
3081 SourceRange UsingDecl::getSourceRange() const {
3082   SourceLocation Begin = isAccessDeclaration()
3083     ? getQualifierLoc().getBeginLoc() : UsingLocation;
3084   return SourceRange(Begin, getNameInfo().getEndLoc());
3085 }
3086 
3087 void UsingEnumDecl::anchor() {}
3088 
3089 UsingEnumDecl *UsingEnumDecl::Create(ASTContext &C, DeclContext *DC,
3090                                      SourceLocation UL, SourceLocation EL,
3091                                      SourceLocation NL, EnumDecl *Enum) {
3092   return new (C, DC) UsingEnumDecl(DC, Enum->getDeclName(), UL, EL, NL, Enum);
3093 }
3094 
3095 UsingEnumDecl *UsingEnumDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3096   return new (C, ID) UsingEnumDecl(nullptr, DeclarationName(), SourceLocation(),
3097                                    SourceLocation(), SourceLocation(), nullptr);
3098 }
3099 
3100 SourceRange UsingEnumDecl::getSourceRange() const {
3101   return SourceRange(EnumLocation, getLocation());
3102 }
3103 
3104 void UsingPackDecl::anchor() {}
3105 
3106 UsingPackDecl *UsingPackDecl::Create(ASTContext &C, DeclContext *DC,
3107                                      NamedDecl *InstantiatedFrom,
3108                                      ArrayRef<NamedDecl *> UsingDecls) {
3109   size_t Extra = additionalSizeToAlloc<NamedDecl *>(UsingDecls.size());
3110   return new (C, DC, Extra) UsingPackDecl(DC, InstantiatedFrom, UsingDecls);
3111 }
3112 
3113 UsingPackDecl *UsingPackDecl::CreateDeserialized(ASTContext &C, unsigned ID,
3114                                                  unsigned NumExpansions) {
3115   size_t Extra = additionalSizeToAlloc<NamedDecl *>(NumExpansions);
3116   auto *Result = new (C, ID, Extra) UsingPackDecl(nullptr, nullptr, None);
3117   Result->NumExpansions = NumExpansions;
3118   auto *Trail = Result->getTrailingObjects<NamedDecl *>();
3119   for (unsigned I = 0; I != NumExpansions; ++I)
3120     new (Trail + I) NamedDecl*(nullptr);
3121   return Result;
3122 }
3123 
3124 void UnresolvedUsingValueDecl::anchor() {}
3125 
3126 UnresolvedUsingValueDecl *
3127 UnresolvedUsingValueDecl::Create(ASTContext &C, DeclContext *DC,
3128                                  SourceLocation UsingLoc,
3129                                  NestedNameSpecifierLoc QualifierLoc,
3130                                  const DeclarationNameInfo &NameInfo,
3131                                  SourceLocation EllipsisLoc) {
3132   return new (C, DC) UnresolvedUsingValueDecl(DC, C.DependentTy, UsingLoc,
3133                                               QualifierLoc, NameInfo,
3134                                               EllipsisLoc);
3135 }
3136 
3137 UnresolvedUsingValueDecl *
3138 UnresolvedUsingValueDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3139   return new (C, ID) UnresolvedUsingValueDecl(nullptr, QualType(),
3140                                               SourceLocation(),
3141                                               NestedNameSpecifierLoc(),
3142                                               DeclarationNameInfo(),
3143                                               SourceLocation());
3144 }
3145 
3146 SourceRange UnresolvedUsingValueDecl::getSourceRange() const {
3147   SourceLocation Begin = isAccessDeclaration()
3148     ? getQualifierLoc().getBeginLoc() : UsingLocation;
3149   return SourceRange(Begin, getNameInfo().getEndLoc());
3150 }
3151 
3152 void UnresolvedUsingTypenameDecl::anchor() {}
3153 
3154 UnresolvedUsingTypenameDecl *
3155 UnresolvedUsingTypenameDecl::Create(ASTContext &C, DeclContext *DC,
3156                                     SourceLocation UsingLoc,
3157                                     SourceLocation TypenameLoc,
3158                                     NestedNameSpecifierLoc QualifierLoc,
3159                                     SourceLocation TargetNameLoc,
3160                                     DeclarationName TargetName,
3161                                     SourceLocation EllipsisLoc) {
3162   return new (C, DC) UnresolvedUsingTypenameDecl(
3163       DC, UsingLoc, TypenameLoc, QualifierLoc, TargetNameLoc,
3164       TargetName.getAsIdentifierInfo(), EllipsisLoc);
3165 }
3166 
3167 UnresolvedUsingTypenameDecl *
3168 UnresolvedUsingTypenameDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3169   return new (C, ID) UnresolvedUsingTypenameDecl(
3170       nullptr, SourceLocation(), SourceLocation(), NestedNameSpecifierLoc(),
3171       SourceLocation(), nullptr, SourceLocation());
3172 }
3173 
3174 UnresolvedUsingIfExistsDecl *
3175 UnresolvedUsingIfExistsDecl::Create(ASTContext &Ctx, DeclContext *DC,
3176                                     SourceLocation Loc, DeclarationName Name) {
3177   return new (Ctx, DC) UnresolvedUsingIfExistsDecl(DC, Loc, Name);
3178 }
3179 
3180 UnresolvedUsingIfExistsDecl *
3181 UnresolvedUsingIfExistsDecl::CreateDeserialized(ASTContext &Ctx, unsigned ID) {
3182   return new (Ctx, ID)
3183       UnresolvedUsingIfExistsDecl(nullptr, SourceLocation(), DeclarationName());
3184 }
3185 
3186 UnresolvedUsingIfExistsDecl::UnresolvedUsingIfExistsDecl(DeclContext *DC,
3187                                                          SourceLocation Loc,
3188                                                          DeclarationName Name)
3189     : NamedDecl(Decl::UnresolvedUsingIfExists, DC, Loc, Name) {}
3190 
3191 void UnresolvedUsingIfExistsDecl::anchor() {}
3192 
3193 void StaticAssertDecl::anchor() {}
3194 
3195 StaticAssertDecl *StaticAssertDecl::Create(ASTContext &C, DeclContext *DC,
3196                                            SourceLocation StaticAssertLoc,
3197                                            Expr *AssertExpr,
3198                                            StringLiteral *Message,
3199                                            SourceLocation RParenLoc,
3200                                            bool Failed) {
3201   return new (C, DC) StaticAssertDecl(DC, StaticAssertLoc, AssertExpr, Message,
3202                                       RParenLoc, Failed);
3203 }
3204 
3205 StaticAssertDecl *StaticAssertDecl::CreateDeserialized(ASTContext &C,
3206                                                        unsigned ID) {
3207   return new (C, ID) StaticAssertDecl(nullptr, SourceLocation(), nullptr,
3208                                       nullptr, SourceLocation(), false);
3209 }
3210 
3211 void BindingDecl::anchor() {}
3212 
3213 BindingDecl *BindingDecl::Create(ASTContext &C, DeclContext *DC,
3214                                  SourceLocation IdLoc, IdentifierInfo *Id) {
3215   return new (C, DC) BindingDecl(DC, IdLoc, Id);
3216 }
3217 
3218 BindingDecl *BindingDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3219   return new (C, ID) BindingDecl(nullptr, SourceLocation(), nullptr);
3220 }
3221 
3222 VarDecl *BindingDecl::getHoldingVar() const {
3223   Expr *B = getBinding();
3224   if (!B)
3225     return nullptr;
3226   auto *DRE = dyn_cast<DeclRefExpr>(B->IgnoreImplicit());
3227   if (!DRE)
3228     return nullptr;
3229 
3230   auto *VD = cast<VarDecl>(DRE->getDecl());
3231   assert(VD->isImplicit() && "holding var for binding decl not implicit");
3232   return VD;
3233 }
3234 
3235 void DecompositionDecl::anchor() {}
3236 
3237 DecompositionDecl *DecompositionDecl::Create(ASTContext &C, DeclContext *DC,
3238                                              SourceLocation StartLoc,
3239                                              SourceLocation LSquareLoc,
3240                                              QualType T, TypeSourceInfo *TInfo,
3241                                              StorageClass SC,
3242                                              ArrayRef<BindingDecl *> Bindings) {
3243   size_t Extra = additionalSizeToAlloc<BindingDecl *>(Bindings.size());
3244   return new (C, DC, Extra)
3245       DecompositionDecl(C, DC, StartLoc, LSquareLoc, T, TInfo, SC, Bindings);
3246 }
3247 
3248 DecompositionDecl *DecompositionDecl::CreateDeserialized(ASTContext &C,
3249                                                          unsigned ID,
3250                                                          unsigned NumBindings) {
3251   size_t Extra = additionalSizeToAlloc<BindingDecl *>(NumBindings);
3252   auto *Result = new (C, ID, Extra)
3253       DecompositionDecl(C, nullptr, SourceLocation(), SourceLocation(),
3254                         QualType(), nullptr, StorageClass(), None);
3255   // Set up and clean out the bindings array.
3256   Result->NumBindings = NumBindings;
3257   auto *Trail = Result->getTrailingObjects<BindingDecl *>();
3258   for (unsigned I = 0; I != NumBindings; ++I)
3259     new (Trail + I) BindingDecl*(nullptr);
3260   return Result;
3261 }
3262 
3263 void DecompositionDecl::printName(llvm::raw_ostream &os) const {
3264   os << '[';
3265   bool Comma = false;
3266   for (const auto *B : bindings()) {
3267     if (Comma)
3268       os << ", ";
3269     B->printName(os);
3270     Comma = true;
3271   }
3272   os << ']';
3273 }
3274 
3275 void MSPropertyDecl::anchor() {}
3276 
3277 MSPropertyDecl *MSPropertyDecl::Create(ASTContext &C, DeclContext *DC,
3278                                        SourceLocation L, DeclarationName N,
3279                                        QualType T, TypeSourceInfo *TInfo,
3280                                        SourceLocation StartL,
3281                                        IdentifierInfo *Getter,
3282                                        IdentifierInfo *Setter) {
3283   return new (C, DC) MSPropertyDecl(DC, L, N, T, TInfo, StartL, Getter, Setter);
3284 }
3285 
3286 MSPropertyDecl *MSPropertyDecl::CreateDeserialized(ASTContext &C,
3287                                                    unsigned ID) {
3288   return new (C, ID) MSPropertyDecl(nullptr, SourceLocation(),
3289                                     DeclarationName(), QualType(), nullptr,
3290                                     SourceLocation(), nullptr, nullptr);
3291 }
3292 
3293 void MSGuidDecl::anchor() {}
3294 
3295 MSGuidDecl::MSGuidDecl(DeclContext *DC, QualType T, Parts P)
3296     : ValueDecl(Decl::MSGuid, DC, SourceLocation(), DeclarationName(), T),
3297       PartVal(P) {}
3298 
3299 MSGuidDecl *MSGuidDecl::Create(const ASTContext &C, QualType T, Parts P) {
3300   DeclContext *DC = C.getTranslationUnitDecl();
3301   return new (C, DC) MSGuidDecl(DC, T, P);
3302 }
3303 
3304 MSGuidDecl *MSGuidDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3305   return new (C, ID) MSGuidDecl(nullptr, QualType(), Parts());
3306 }
3307 
3308 void MSGuidDecl::printName(llvm::raw_ostream &OS) const {
3309   OS << llvm::format("GUID{%08" PRIx32 "-%04" PRIx16 "-%04" PRIx16 "-",
3310                      PartVal.Part1, PartVal.Part2, PartVal.Part3);
3311   unsigned I = 0;
3312   for (uint8_t Byte : PartVal.Part4And5) {
3313     OS << llvm::format("%02" PRIx8, Byte);
3314     if (++I == 2)
3315       OS << '-';
3316   }
3317   OS << '}';
3318 }
3319 
3320 /// Determine if T is a valid 'struct _GUID' of the shape that we expect.
3321 static bool isValidStructGUID(ASTContext &Ctx, QualType T) {
3322   // FIXME: We only need to check this once, not once each time we compute a
3323   // GUID APValue.
3324   using MatcherRef = llvm::function_ref<bool(QualType)>;
3325 
3326   auto IsInt = [&Ctx](unsigned N) {
3327     return [&Ctx, N](QualType T) {
3328       return T->isUnsignedIntegerOrEnumerationType() &&
3329              Ctx.getIntWidth(T) == N;
3330     };
3331   };
3332 
3333   auto IsArray = [&Ctx](MatcherRef Elem, unsigned N) {
3334     return [&Ctx, Elem, N](QualType T) {
3335       const ConstantArrayType *CAT = Ctx.getAsConstantArrayType(T);
3336       return CAT && CAT->getSize() == N && Elem(CAT->getElementType());
3337     };
3338   };
3339 
3340   auto IsStruct = [](std::initializer_list<MatcherRef> Fields) {
3341     return [Fields](QualType T) {
3342       const RecordDecl *RD = T->getAsRecordDecl();
3343       if (!RD || RD->isUnion())
3344         return false;
3345       RD = RD->getDefinition();
3346       if (!RD)
3347         return false;
3348       if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
3349         if (CXXRD->getNumBases())
3350           return false;
3351       auto MatcherIt = Fields.begin();
3352       for (const FieldDecl *FD : RD->fields()) {
3353         if (FD->isUnnamedBitfield()) continue;
3354         if (FD->isBitField() || MatcherIt == Fields.end() ||
3355             !(*MatcherIt)(FD->getType()))
3356           return false;
3357         ++MatcherIt;
3358       }
3359       return MatcherIt == Fields.end();
3360     };
3361   };
3362 
3363   // We expect an {i32, i16, i16, [8 x i8]}.
3364   return IsStruct({IsInt(32), IsInt(16), IsInt(16), IsArray(IsInt(8), 8)})(T);
3365 }
3366 
3367 APValue &MSGuidDecl::getAsAPValue() const {
3368   if (APVal.isAbsent() && isValidStructGUID(getASTContext(), getType())) {
3369     using llvm::APInt;
3370     using llvm::APSInt;
3371     APVal = APValue(APValue::UninitStruct(), 0, 4);
3372     APVal.getStructField(0) = APValue(APSInt(APInt(32, PartVal.Part1), true));
3373     APVal.getStructField(1) = APValue(APSInt(APInt(16, PartVal.Part2), true));
3374     APVal.getStructField(2) = APValue(APSInt(APInt(16, PartVal.Part3), true));
3375     APValue &Arr = APVal.getStructField(3) =
3376         APValue(APValue::UninitArray(), 8, 8);
3377     for (unsigned I = 0; I != 8; ++I) {
3378       Arr.getArrayInitializedElt(I) =
3379           APValue(APSInt(APInt(8, PartVal.Part4And5[I]), true));
3380     }
3381     // Register this APValue to be destroyed if necessary. (Note that the
3382     // MSGuidDecl destructor is never run.)
3383     getASTContext().addDestruction(&APVal);
3384   }
3385 
3386   return APVal;
3387 }
3388 
3389 void UnnamedGlobalConstantDecl::anchor() {}
3390 
3391 UnnamedGlobalConstantDecl::UnnamedGlobalConstantDecl(const ASTContext &C,
3392                                                      DeclContext *DC,
3393                                                      QualType Ty,
3394                                                      const APValue &Val)
3395     : ValueDecl(Decl::UnnamedGlobalConstant, DC, SourceLocation(),
3396                 DeclarationName(), Ty),
3397       Value(Val) {
3398   // Cleanup the embedded APValue if required (note that our destructor is never
3399   // run)
3400   if (Value.needsCleanup())
3401     C.addDestruction(&Value);
3402 }
3403 
3404 UnnamedGlobalConstantDecl *
3405 UnnamedGlobalConstantDecl::Create(const ASTContext &C, QualType T,
3406                                   const APValue &Value) {
3407   DeclContext *DC = C.getTranslationUnitDecl();
3408   return new (C, DC) UnnamedGlobalConstantDecl(C, DC, T, Value);
3409 }
3410 
3411 UnnamedGlobalConstantDecl *
3412 UnnamedGlobalConstantDecl::CreateDeserialized(ASTContext &C, unsigned ID) {
3413   return new (C, ID)
3414       UnnamedGlobalConstantDecl(C, nullptr, QualType(), APValue());
3415 }
3416 
3417 void UnnamedGlobalConstantDecl::printName(llvm::raw_ostream &OS) const {
3418   OS << "unnamed-global-constant";
3419 }
3420 
3421 static const char *getAccessName(AccessSpecifier AS) {
3422   switch (AS) {
3423     case AS_none:
3424       llvm_unreachable("Invalid access specifier!");
3425     case AS_public:
3426       return "public";
3427     case AS_private:
3428       return "private";
3429     case AS_protected:
3430       return "protected";
3431   }
3432   llvm_unreachable("Invalid access specifier!");
3433 }
3434 
3435 const StreamingDiagnostic &clang::operator<<(const StreamingDiagnostic &DB,
3436                                              AccessSpecifier AS) {
3437   return DB << getAccessName(AS);
3438 }
3439