xref: /freebsd/contrib/llvm-project/clang/lib/AST/MicrosoftMangle.cpp (revision 66fd12cf4896eb08ad8e7a2627537f84ead84dd3)
1 //===--- MicrosoftMangle.cpp - Microsoft Visual C++ Name Mangling ---------===//
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 provides C++ name mangling targeting the Microsoft Visual C++ ABI.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "clang/AST/ASTContext.h"
14 #include "clang/AST/Attr.h"
15 #include "clang/AST/CXXInheritance.h"
16 #include "clang/AST/CharUnits.h"
17 #include "clang/AST/Decl.h"
18 #include "clang/AST/DeclCXX.h"
19 #include "clang/AST/DeclObjC.h"
20 #include "clang/AST/DeclOpenMP.h"
21 #include "clang/AST/DeclTemplate.h"
22 #include "clang/AST/Expr.h"
23 #include "clang/AST/ExprCXX.h"
24 #include "clang/AST/GlobalDecl.h"
25 #include "clang/AST/Mangle.h"
26 #include "clang/AST/VTableBuilder.h"
27 #include "clang/Basic/ABI.h"
28 #include "clang/Basic/DiagnosticOptions.h"
29 #include "clang/Basic/FileManager.h"
30 #include "clang/Basic/SourceManager.h"
31 #include "clang/Basic/TargetInfo.h"
32 #include "llvm/ADT/StringExtras.h"
33 #include "llvm/Support/CRC.h"
34 #include "llvm/Support/MD5.h"
35 #include "llvm/Support/MathExtras.h"
36 #include "llvm/Support/StringSaver.h"
37 #include "llvm/Support/xxhash.h"
38 #include <optional>
39 
40 using namespace clang;
41 
42 namespace {
43 
44 // Get GlobalDecl of DeclContext of local entities.
45 static GlobalDecl getGlobalDeclAsDeclContext(const DeclContext *DC) {
46   GlobalDecl GD;
47   if (auto *CD = dyn_cast<CXXConstructorDecl>(DC))
48     GD = GlobalDecl(CD, Ctor_Complete);
49   else if (auto *DD = dyn_cast<CXXDestructorDecl>(DC))
50     GD = GlobalDecl(DD, Dtor_Complete);
51   else
52     GD = GlobalDecl(cast<FunctionDecl>(DC));
53   return GD;
54 }
55 
56 struct msvc_hashing_ostream : public llvm::raw_svector_ostream {
57   raw_ostream &OS;
58   llvm::SmallString<64> Buffer;
59 
60   msvc_hashing_ostream(raw_ostream &OS)
61       : llvm::raw_svector_ostream(Buffer), OS(OS) {}
62   ~msvc_hashing_ostream() override {
63     StringRef MangledName = str();
64     bool StartsWithEscape = MangledName.startswith("\01");
65     if (StartsWithEscape)
66       MangledName = MangledName.drop_front(1);
67     if (MangledName.size() < 4096) {
68       OS << str();
69       return;
70     }
71 
72     llvm::MD5 Hasher;
73     llvm::MD5::MD5Result Hash;
74     Hasher.update(MangledName);
75     Hasher.final(Hash);
76 
77     SmallString<32> HexString;
78     llvm::MD5::stringifyResult(Hash, HexString);
79 
80     if (StartsWithEscape)
81       OS << '\01';
82     OS << "??@" << HexString << '@';
83   }
84 };
85 
86 static const DeclContext *
87 getLambdaDefaultArgumentDeclContext(const Decl *D) {
88   if (const auto *RD = dyn_cast<CXXRecordDecl>(D))
89     if (RD->isLambda())
90       if (const auto *Parm =
91               dyn_cast_or_null<ParmVarDecl>(RD->getLambdaContextDecl()))
92         return Parm->getDeclContext();
93   return nullptr;
94 }
95 
96 /// Retrieve the declaration context that should be used when mangling
97 /// the given declaration.
98 static const DeclContext *getEffectiveDeclContext(const Decl *D) {
99   // The ABI assumes that lambda closure types that occur within
100   // default arguments live in the context of the function. However, due to
101   // the way in which Clang parses and creates function declarations, this is
102   // not the case: the lambda closure type ends up living in the context
103   // where the function itself resides, because the function declaration itself
104   // had not yet been created. Fix the context here.
105   if (const auto *LDADC = getLambdaDefaultArgumentDeclContext(D))
106     return LDADC;
107 
108   // Perform the same check for block literals.
109   if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
110     if (ParmVarDecl *ContextParam =
111             dyn_cast_or_null<ParmVarDecl>(BD->getBlockManglingContextDecl()))
112       return ContextParam->getDeclContext();
113   }
114 
115   const DeclContext *DC = D->getDeclContext();
116   if (isa<CapturedDecl>(DC) || isa<OMPDeclareReductionDecl>(DC) ||
117       isa<OMPDeclareMapperDecl>(DC)) {
118     return getEffectiveDeclContext(cast<Decl>(DC));
119   }
120 
121   return DC->getRedeclContext();
122 }
123 
124 static const DeclContext *getEffectiveParentContext(const DeclContext *DC) {
125   return getEffectiveDeclContext(cast<Decl>(DC));
126 }
127 
128 static const FunctionDecl *getStructor(const NamedDecl *ND) {
129   if (const auto *FTD = dyn_cast<FunctionTemplateDecl>(ND))
130     return FTD->getTemplatedDecl()->getCanonicalDecl();
131 
132   const auto *FD = cast<FunctionDecl>(ND);
133   if (const auto *FTD = FD->getPrimaryTemplate())
134     return FTD->getTemplatedDecl()->getCanonicalDecl();
135 
136   return FD->getCanonicalDecl();
137 }
138 
139 /// MicrosoftMangleContextImpl - Overrides the default MangleContext for the
140 /// Microsoft Visual C++ ABI.
141 class MicrosoftMangleContextImpl : public MicrosoftMangleContext {
142   typedef std::pair<const DeclContext *, IdentifierInfo *> DiscriminatorKeyTy;
143   llvm::DenseMap<DiscriminatorKeyTy, unsigned> Discriminator;
144   llvm::DenseMap<const NamedDecl *, unsigned> Uniquifier;
145   llvm::DenseMap<const CXXRecordDecl *, unsigned> LambdaIds;
146   llvm::DenseMap<GlobalDecl, unsigned> SEHFilterIds;
147   llvm::DenseMap<GlobalDecl, unsigned> SEHFinallyIds;
148   SmallString<16> AnonymousNamespaceHash;
149 
150 public:
151   MicrosoftMangleContextImpl(ASTContext &Context, DiagnosticsEngine &Diags,
152                              bool IsAux = false);
153   bool shouldMangleCXXName(const NamedDecl *D) override;
154   bool shouldMangleStringLiteral(const StringLiteral *SL) override;
155   void mangleCXXName(GlobalDecl GD, raw_ostream &Out) override;
156   void mangleVirtualMemPtrThunk(const CXXMethodDecl *MD,
157                                 const MethodVFTableLocation &ML,
158                                 raw_ostream &Out) override;
159   void mangleThunk(const CXXMethodDecl *MD, const ThunkInfo &Thunk,
160                    raw_ostream &) override;
161   void mangleCXXDtorThunk(const CXXDestructorDecl *DD, CXXDtorType Type,
162                           const ThisAdjustment &ThisAdjustment,
163                           raw_ostream &) override;
164   void mangleCXXVFTable(const CXXRecordDecl *Derived,
165                         ArrayRef<const CXXRecordDecl *> BasePath,
166                         raw_ostream &Out) override;
167   void mangleCXXVBTable(const CXXRecordDecl *Derived,
168                         ArrayRef<const CXXRecordDecl *> BasePath,
169                         raw_ostream &Out) override;
170   void mangleCXXVirtualDisplacementMap(const CXXRecordDecl *SrcRD,
171                                        const CXXRecordDecl *DstRD,
172                                        raw_ostream &Out) override;
173   void mangleCXXThrowInfo(QualType T, bool IsConst, bool IsVolatile,
174                           bool IsUnaligned, uint32_t NumEntries,
175                           raw_ostream &Out) override;
176   void mangleCXXCatchableTypeArray(QualType T, uint32_t NumEntries,
177                                    raw_ostream &Out) override;
178   void mangleCXXCatchableType(QualType T, const CXXConstructorDecl *CD,
179                               CXXCtorType CT, uint32_t Size, uint32_t NVOffset,
180                               int32_t VBPtrOffset, uint32_t VBIndex,
181                               raw_ostream &Out) override;
182   void mangleCXXRTTI(QualType T, raw_ostream &Out) override;
183   void mangleCXXRTTIName(QualType T, raw_ostream &Out) override;
184   void mangleCXXRTTIBaseClassDescriptor(const CXXRecordDecl *Derived,
185                                         uint32_t NVOffset, int32_t VBPtrOffset,
186                                         uint32_t VBTableOffset, uint32_t Flags,
187                                         raw_ostream &Out) override;
188   void mangleCXXRTTIBaseClassArray(const CXXRecordDecl *Derived,
189                                    raw_ostream &Out) override;
190   void mangleCXXRTTIClassHierarchyDescriptor(const CXXRecordDecl *Derived,
191                                              raw_ostream &Out) override;
192   void
193   mangleCXXRTTICompleteObjectLocator(const CXXRecordDecl *Derived,
194                                      ArrayRef<const CXXRecordDecl *> BasePath,
195                                      raw_ostream &Out) override;
196   void mangleTypeName(QualType T, raw_ostream &) override;
197   void mangleReferenceTemporary(const VarDecl *, unsigned ManglingNumber,
198                                 raw_ostream &) override;
199   void mangleStaticGuardVariable(const VarDecl *D, raw_ostream &Out) override;
200   void mangleThreadSafeStaticGuardVariable(const VarDecl *D, unsigned GuardNum,
201                                            raw_ostream &Out) override;
202   void mangleDynamicInitializer(const VarDecl *D, raw_ostream &Out) override;
203   void mangleDynamicAtExitDestructor(const VarDecl *D,
204                                      raw_ostream &Out) override;
205   void mangleSEHFilterExpression(GlobalDecl EnclosingDecl,
206                                  raw_ostream &Out) override;
207   void mangleSEHFinallyBlock(GlobalDecl EnclosingDecl,
208                              raw_ostream &Out) override;
209   void mangleStringLiteral(const StringLiteral *SL, raw_ostream &Out) override;
210   bool getNextDiscriminator(const NamedDecl *ND, unsigned &disc) {
211     const DeclContext *DC = getEffectiveDeclContext(ND);
212     if (!DC->isFunctionOrMethod())
213       return false;
214 
215     // Lambda closure types are already numbered, give out a phony number so
216     // that they demangle nicely.
217     if (const auto *RD = dyn_cast<CXXRecordDecl>(ND)) {
218       if (RD->isLambda()) {
219         disc = 1;
220         return true;
221       }
222     }
223 
224     // Use the canonical number for externally visible decls.
225     if (ND->isExternallyVisible()) {
226       disc = getASTContext().getManglingNumber(ND, isAux());
227       return true;
228     }
229 
230     // Anonymous tags are already numbered.
231     if (const TagDecl *Tag = dyn_cast<TagDecl>(ND)) {
232       if (!Tag->hasNameForLinkage() &&
233           !getASTContext().getDeclaratorForUnnamedTagDecl(Tag) &&
234           !getASTContext().getTypedefNameForUnnamedTagDecl(Tag))
235         return false;
236     }
237 
238     // Make up a reasonable number for internal decls.
239     unsigned &discriminator = Uniquifier[ND];
240     if (!discriminator)
241       discriminator = ++Discriminator[std::make_pair(DC, ND->getIdentifier())];
242     disc = discriminator + 1;
243     return true;
244   }
245 
246   std::string getLambdaString(const CXXRecordDecl *Lambda) override {
247     assert(Lambda->isLambda() && "RD must be a lambda!");
248     std::string Name("<lambda_");
249 
250     Decl *LambdaContextDecl = Lambda->getLambdaContextDecl();
251     unsigned LambdaManglingNumber = Lambda->getLambdaManglingNumber();
252     unsigned LambdaId;
253     const ParmVarDecl *Parm = dyn_cast_or_null<ParmVarDecl>(LambdaContextDecl);
254     const FunctionDecl *Func =
255         Parm ? dyn_cast<FunctionDecl>(Parm->getDeclContext()) : nullptr;
256 
257     if (Func) {
258       unsigned DefaultArgNo =
259           Func->getNumParams() - Parm->getFunctionScopeIndex();
260       Name += llvm::utostr(DefaultArgNo);
261       Name += "_";
262     }
263 
264     if (LambdaManglingNumber)
265       LambdaId = LambdaManglingNumber;
266     else
267       LambdaId = getLambdaIdForDebugInfo(Lambda);
268 
269     Name += llvm::utostr(LambdaId);
270     Name += ">";
271     return Name;
272   }
273 
274   unsigned getLambdaId(const CXXRecordDecl *RD) {
275     assert(RD->isLambda() && "RD must be a lambda!");
276     assert(!RD->isExternallyVisible() && "RD must not be visible!");
277     assert(RD->getLambdaManglingNumber() == 0 &&
278            "RD must not have a mangling number!");
279     std::pair<llvm::DenseMap<const CXXRecordDecl *, unsigned>::iterator, bool>
280         Result = LambdaIds.insert(std::make_pair(RD, LambdaIds.size()));
281     return Result.first->second;
282   }
283 
284   unsigned getLambdaIdForDebugInfo(const CXXRecordDecl *RD) {
285     assert(RD->isLambda() && "RD must be a lambda!");
286     assert(!RD->isExternallyVisible() && "RD must not be visible!");
287     assert(RD->getLambdaManglingNumber() == 0 &&
288            "RD must not have a mangling number!");
289     llvm::DenseMap<const CXXRecordDecl *, unsigned>::iterator Result =
290         LambdaIds.find(RD);
291     // The lambda should exist, but return 0 in case it doesn't.
292     if (Result == LambdaIds.end())
293       return 0;
294     return Result->second;
295   }
296 
297   /// Return a character sequence that is (somewhat) unique to the TU suitable
298   /// for mangling anonymous namespaces.
299   StringRef getAnonymousNamespaceHash() const {
300     return AnonymousNamespaceHash;
301   }
302 
303 private:
304   void mangleInitFiniStub(const VarDecl *D, char CharCode, raw_ostream &Out);
305 };
306 
307 /// MicrosoftCXXNameMangler - Manage the mangling of a single name for the
308 /// Microsoft Visual C++ ABI.
309 class MicrosoftCXXNameMangler {
310   MicrosoftMangleContextImpl &Context;
311   raw_ostream &Out;
312 
313   /// The "structor" is the top-level declaration being mangled, if
314   /// that's not a template specialization; otherwise it's the pattern
315   /// for that specialization.
316   const NamedDecl *Structor;
317   unsigned StructorType;
318 
319   typedef llvm::SmallVector<std::string, 10> BackRefVec;
320   BackRefVec NameBackReferences;
321 
322   typedef llvm::DenseMap<const void *, unsigned> ArgBackRefMap;
323   ArgBackRefMap FunArgBackReferences;
324   ArgBackRefMap TemplateArgBackReferences;
325 
326   typedef llvm::DenseMap<const void *, StringRef> TemplateArgStringMap;
327   TemplateArgStringMap TemplateArgStrings;
328   llvm::StringSaver TemplateArgStringStorage;
329   llvm::BumpPtrAllocator TemplateArgStringStorageAlloc;
330 
331   typedef std::set<std::pair<int, bool>> PassObjectSizeArgsSet;
332   PassObjectSizeArgsSet PassObjectSizeArgs;
333 
334   ASTContext &getASTContext() const { return Context.getASTContext(); }
335 
336   const bool PointersAre64Bit;
337 
338 public:
339   enum QualifierMangleMode { QMM_Drop, QMM_Mangle, QMM_Escape, QMM_Result };
340 
341   MicrosoftCXXNameMangler(MicrosoftMangleContextImpl &C, raw_ostream &Out_)
342       : Context(C), Out(Out_), Structor(nullptr), StructorType(-1),
343         TemplateArgStringStorage(TemplateArgStringStorageAlloc),
344         PointersAre64Bit(C.getASTContext().getTargetInfo().getPointerWidth(
345                              LangAS::Default) == 64) {}
346 
347   MicrosoftCXXNameMangler(MicrosoftMangleContextImpl &C, raw_ostream &Out_,
348                           const CXXConstructorDecl *D, CXXCtorType Type)
349       : Context(C), Out(Out_), Structor(getStructor(D)), StructorType(Type),
350         TemplateArgStringStorage(TemplateArgStringStorageAlloc),
351         PointersAre64Bit(C.getASTContext().getTargetInfo().getPointerWidth(
352                              LangAS::Default) == 64) {}
353 
354   MicrosoftCXXNameMangler(MicrosoftMangleContextImpl &C, raw_ostream &Out_,
355                           const CXXDestructorDecl *D, CXXDtorType Type)
356       : Context(C), Out(Out_), Structor(getStructor(D)), StructorType(Type),
357         TemplateArgStringStorage(TemplateArgStringStorageAlloc),
358         PointersAre64Bit(C.getASTContext().getTargetInfo().getPointerWidth(
359                              LangAS::Default) == 64) {}
360 
361   raw_ostream &getStream() const { return Out; }
362 
363   void mangle(GlobalDecl GD, StringRef Prefix = "?");
364   void mangleName(GlobalDecl GD);
365   void mangleFunctionEncoding(GlobalDecl GD, bool ShouldMangle);
366   void mangleVariableEncoding(const VarDecl *VD);
367   void mangleMemberDataPointer(const CXXRecordDecl *RD, const ValueDecl *VD,
368                                StringRef Prefix = "$");
369   void mangleMemberFunctionPointer(const CXXRecordDecl *RD,
370                                    const CXXMethodDecl *MD,
371                                    StringRef Prefix = "$");
372   void mangleVirtualMemPtrThunk(const CXXMethodDecl *MD,
373                                 const MethodVFTableLocation &ML);
374   void mangleNumber(int64_t Number);
375   void mangleNumber(llvm::APSInt Number);
376   void mangleFloat(llvm::APFloat Number);
377   void mangleBits(llvm::APInt Number);
378   void mangleTagTypeKind(TagTypeKind TK);
379   void mangleArtificialTagType(TagTypeKind TK, StringRef UnqualifiedName,
380                                ArrayRef<StringRef> NestedNames = std::nullopt);
381   void mangleAddressSpaceType(QualType T, Qualifiers Quals, SourceRange Range);
382   void mangleType(QualType T, SourceRange Range,
383                   QualifierMangleMode QMM = QMM_Mangle);
384   void mangleFunctionType(const FunctionType *T,
385                           const FunctionDecl *D = nullptr,
386                           bool ForceThisQuals = false,
387                           bool MangleExceptionSpec = true);
388   void mangleNestedName(GlobalDecl GD);
389 
390 private:
391   bool isStructorDecl(const NamedDecl *ND) const {
392     return ND == Structor || getStructor(ND) == Structor;
393   }
394 
395   bool is64BitPointer(Qualifiers Quals) const {
396     LangAS AddrSpace = Quals.getAddressSpace();
397     return AddrSpace == LangAS::ptr64 ||
398            (PointersAre64Bit && !(AddrSpace == LangAS::ptr32_sptr ||
399                                   AddrSpace == LangAS::ptr32_uptr));
400   }
401 
402   void mangleUnqualifiedName(GlobalDecl GD) {
403     mangleUnqualifiedName(GD, cast<NamedDecl>(GD.getDecl())->getDeclName());
404   }
405   void mangleUnqualifiedName(GlobalDecl GD, DeclarationName Name);
406   void mangleSourceName(StringRef Name);
407   void mangleOperatorName(OverloadedOperatorKind OO, SourceLocation Loc);
408   void mangleCXXDtorType(CXXDtorType T);
409   void mangleQualifiers(Qualifiers Quals, bool IsMember);
410   void mangleRefQualifier(RefQualifierKind RefQualifier);
411   void manglePointerCVQualifiers(Qualifiers Quals);
412   void manglePointerExtQualifiers(Qualifiers Quals, QualType PointeeType);
413 
414   void mangleUnscopedTemplateName(GlobalDecl GD);
415   void
416   mangleTemplateInstantiationName(GlobalDecl GD,
417                                   const TemplateArgumentList &TemplateArgs);
418   void mangleObjCMethodName(const ObjCMethodDecl *MD);
419 
420   void mangleFunctionArgumentType(QualType T, SourceRange Range);
421   void manglePassObjectSizeArg(const PassObjectSizeAttr *POSA);
422 
423   bool isArtificialTagType(QualType T) const;
424 
425   // Declare manglers for every type class.
426 #define ABSTRACT_TYPE(CLASS, PARENT)
427 #define NON_CANONICAL_TYPE(CLASS, PARENT)
428 #define TYPE(CLASS, PARENT) void mangleType(const CLASS##Type *T, \
429                                             Qualifiers Quals, \
430                                             SourceRange Range);
431 #include "clang/AST/TypeNodes.inc"
432 #undef ABSTRACT_TYPE
433 #undef NON_CANONICAL_TYPE
434 #undef TYPE
435 
436   void mangleType(const TagDecl *TD);
437   void mangleDecayedArrayType(const ArrayType *T);
438   void mangleArrayType(const ArrayType *T);
439   void mangleFunctionClass(const FunctionDecl *FD);
440   void mangleCallingConvention(CallingConv CC);
441   void mangleCallingConvention(const FunctionType *T);
442   void mangleIntegerLiteral(const llvm::APSInt &Number,
443                             const NonTypeTemplateParmDecl *PD = nullptr,
444                             QualType TemplateArgType = QualType());
445   void mangleExpression(const Expr *E, const NonTypeTemplateParmDecl *PD);
446   void mangleThrowSpecification(const FunctionProtoType *T);
447 
448   void mangleTemplateArgs(const TemplateDecl *TD,
449                           const TemplateArgumentList &TemplateArgs);
450   void mangleTemplateArg(const TemplateDecl *TD, const TemplateArgument &TA,
451                          const NamedDecl *Parm);
452   void mangleTemplateArgValue(QualType T, const APValue &V,
453                               bool WithScalarType = false);
454 
455   void mangleObjCProtocol(const ObjCProtocolDecl *PD);
456   void mangleObjCLifetime(const QualType T, Qualifiers Quals,
457                           SourceRange Range);
458   void mangleObjCKindOfType(const ObjCObjectType *T, Qualifiers Quals,
459                             SourceRange Range);
460 };
461 }
462 
463 MicrosoftMangleContextImpl::MicrosoftMangleContextImpl(ASTContext &Context,
464                                                        DiagnosticsEngine &Diags,
465                                                        bool IsAux)
466     : MicrosoftMangleContext(Context, Diags, IsAux) {
467   // To mangle anonymous namespaces, hash the path to the main source file. The
468   // path should be whatever (probably relative) path was passed on the command
469   // line. The goal is for the compiler to produce the same output regardless of
470   // working directory, so use the uncanonicalized relative path.
471   //
472   // It's important to make the mangled names unique because, when CodeView
473   // debug info is in use, the debugger uses mangled type names to distinguish
474   // between otherwise identically named types in anonymous namespaces.
475   //
476   // These symbols are always internal, so there is no need for the hash to
477   // match what MSVC produces. For the same reason, clang is free to change the
478   // hash at any time without breaking compatibility with old versions of clang.
479   // The generated names are intended to look similar to what MSVC generates,
480   // which are something like "?A0x01234567@".
481   SourceManager &SM = Context.getSourceManager();
482   if (const FileEntry *FE = SM.getFileEntryForID(SM.getMainFileID())) {
483     // Truncate the hash so we get 8 characters of hexadecimal.
484     uint32_t TruncatedHash = uint32_t(xxHash64(FE->getName()));
485     AnonymousNamespaceHash = llvm::utohexstr(TruncatedHash);
486   } else {
487     // If we don't have a path to the main file, we'll just use 0.
488     AnonymousNamespaceHash = "0";
489   }
490 }
491 
492 bool MicrosoftMangleContextImpl::shouldMangleCXXName(const NamedDecl *D) {
493   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
494     LanguageLinkage L = FD->getLanguageLinkage();
495     // Overloadable functions need mangling.
496     if (FD->hasAttr<OverloadableAttr>())
497       return true;
498 
499     // The ABI expects that we would never mangle "typical" user-defined entry
500     // points regardless of visibility or freestanding-ness.
501     //
502     // N.B. This is distinct from asking about "main".  "main" has a lot of
503     // special rules associated with it in the standard while these
504     // user-defined entry points are outside of the purview of the standard.
505     // For example, there can be only one definition for "main" in a standards
506     // compliant program; however nothing forbids the existence of wmain and
507     // WinMain in the same translation unit.
508     if (FD->isMSVCRTEntryPoint())
509       return false;
510 
511     // C++ functions and those whose names are not a simple identifier need
512     // mangling.
513     if (!FD->getDeclName().isIdentifier() || L == CXXLanguageLinkage)
514       return true;
515 
516     // C functions are not mangled.
517     if (L == CLanguageLinkage)
518       return false;
519   }
520 
521   // Otherwise, no mangling is done outside C++ mode.
522   if (!getASTContext().getLangOpts().CPlusPlus)
523     return false;
524 
525   const VarDecl *VD = dyn_cast<VarDecl>(D);
526   if (VD && !isa<DecompositionDecl>(D)) {
527     // C variables are not mangled.
528     if (VD->isExternC())
529       return false;
530 
531     // Variables at global scope with internal linkage are not mangled.
532     const DeclContext *DC = getEffectiveDeclContext(D);
533     // Check for extern variable declared locally.
534     if (DC->isFunctionOrMethod() && D->hasLinkage())
535       while (!DC->isNamespace() && !DC->isTranslationUnit())
536         DC = getEffectiveParentContext(DC);
537 
538     if (DC->isTranslationUnit() && D->getFormalLinkage() == InternalLinkage &&
539         !isa<VarTemplateSpecializationDecl>(D) &&
540         D->getIdentifier() != nullptr)
541       return false;
542   }
543 
544   return true;
545 }
546 
547 bool
548 MicrosoftMangleContextImpl::shouldMangleStringLiteral(const StringLiteral *SL) {
549   return true;
550 }
551 
552 void MicrosoftCXXNameMangler::mangle(GlobalDecl GD, StringRef Prefix) {
553   const NamedDecl *D = cast<NamedDecl>(GD.getDecl());
554   // MSVC doesn't mangle C++ names the same way it mangles extern "C" names.
555   // Therefore it's really important that we don't decorate the
556   // name with leading underscores or leading/trailing at signs. So, by
557   // default, we emit an asm marker at the start so we get the name right.
558   // Callers can override this with a custom prefix.
559 
560   // <mangled-name> ::= ? <name> <type-encoding>
561   Out << Prefix;
562   mangleName(GD);
563   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
564     mangleFunctionEncoding(GD, Context.shouldMangleDeclName(FD));
565   else if (const VarDecl *VD = dyn_cast<VarDecl>(D))
566     mangleVariableEncoding(VD);
567   else if (isa<MSGuidDecl>(D))
568     // MSVC appears to mangle GUIDs as if they were variables of type
569     // 'const struct __s_GUID'.
570     Out << "3U__s_GUID@@B";
571   else if (isa<TemplateParamObjectDecl>(D)) {
572     // Template parameter objects don't get a <type-encoding>; their type is
573     // specified as part of their value.
574   } else
575     llvm_unreachable("Tried to mangle unexpected NamedDecl!");
576 }
577 
578 void MicrosoftCXXNameMangler::mangleFunctionEncoding(GlobalDecl GD,
579                                                      bool ShouldMangle) {
580   const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
581   // <type-encoding> ::= <function-class> <function-type>
582 
583   // Since MSVC operates on the type as written and not the canonical type, it
584   // actually matters which decl we have here.  MSVC appears to choose the
585   // first, since it is most likely to be the declaration in a header file.
586   FD = FD->getFirstDecl();
587 
588   // We should never ever see a FunctionNoProtoType at this point.
589   // We don't even know how to mangle their types anyway :).
590   const FunctionProtoType *FT = FD->getType()->castAs<FunctionProtoType>();
591 
592   // extern "C" functions can hold entities that must be mangled.
593   // As it stands, these functions still need to get expressed in the full
594   // external name.  They have their class and type omitted, replaced with '9'.
595   if (ShouldMangle) {
596     // We would like to mangle all extern "C" functions using this additional
597     // component but this would break compatibility with MSVC's behavior.
598     // Instead, do this when we know that compatibility isn't important (in
599     // other words, when it is an overloaded extern "C" function).
600     if (FD->isExternC() && FD->hasAttr<OverloadableAttr>())
601       Out << "$$J0";
602 
603     mangleFunctionClass(FD);
604 
605     mangleFunctionType(FT, FD, false, false);
606   } else {
607     Out << '9';
608   }
609 }
610 
611 void MicrosoftCXXNameMangler::mangleVariableEncoding(const VarDecl *VD) {
612   // <type-encoding> ::= <storage-class> <variable-type>
613   // <storage-class> ::= 0  # private static member
614   //                 ::= 1  # protected static member
615   //                 ::= 2  # public static member
616   //                 ::= 3  # global
617   //                 ::= 4  # static local
618 
619   // The first character in the encoding (after the name) is the storage class.
620   if (VD->isStaticDataMember()) {
621     // If it's a static member, it also encodes the access level.
622     switch (VD->getAccess()) {
623       default:
624       case AS_private: Out << '0'; break;
625       case AS_protected: Out << '1'; break;
626       case AS_public: Out << '2'; break;
627     }
628   }
629   else if (!VD->isStaticLocal())
630     Out << '3';
631   else
632     Out << '4';
633   // Now mangle the type.
634   // <variable-type> ::= <type> <cvr-qualifiers>
635   //                 ::= <type> <pointee-cvr-qualifiers> # pointers, references
636   // Pointers and references are odd. The type of 'int * const foo;' gets
637   // mangled as 'QAHA' instead of 'PAHB', for example.
638   SourceRange SR = VD->getSourceRange();
639   QualType Ty = VD->getType();
640   if (Ty->isPointerType() || Ty->isReferenceType() ||
641       Ty->isMemberPointerType()) {
642     mangleType(Ty, SR, QMM_Drop);
643     manglePointerExtQualifiers(
644         Ty.getDesugaredType(getASTContext()).getLocalQualifiers(), QualType());
645     if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) {
646       mangleQualifiers(MPT->getPointeeType().getQualifiers(), true);
647       // Member pointers are suffixed with a back reference to the member
648       // pointer's class name.
649       mangleName(MPT->getClass()->getAsCXXRecordDecl());
650     } else
651       mangleQualifiers(Ty->getPointeeType().getQualifiers(), false);
652   } else if (const ArrayType *AT = getASTContext().getAsArrayType(Ty)) {
653     // Global arrays are funny, too.
654     mangleDecayedArrayType(AT);
655     if (AT->getElementType()->isArrayType())
656       Out << 'A';
657     else
658       mangleQualifiers(Ty.getQualifiers(), false);
659   } else {
660     mangleType(Ty, SR, QMM_Drop);
661     mangleQualifiers(Ty.getQualifiers(), false);
662   }
663 }
664 
665 void MicrosoftCXXNameMangler::mangleMemberDataPointer(const CXXRecordDecl *RD,
666                                                       const ValueDecl *VD,
667                                                       StringRef Prefix) {
668   // <member-data-pointer> ::= <integer-literal>
669   //                       ::= $F <number> <number>
670   //                       ::= $G <number> <number> <number>
671 
672   int64_t FieldOffset;
673   int64_t VBTableOffset;
674   MSInheritanceModel IM = RD->getMSInheritanceModel();
675   if (VD) {
676     FieldOffset = getASTContext().getFieldOffset(VD);
677     assert(FieldOffset % getASTContext().getCharWidth() == 0 &&
678            "cannot take address of bitfield");
679     FieldOffset /= getASTContext().getCharWidth();
680 
681     VBTableOffset = 0;
682 
683     if (IM == MSInheritanceModel::Virtual)
684       FieldOffset -= getASTContext().getOffsetOfBaseWithVBPtr(RD).getQuantity();
685   } else {
686     FieldOffset = RD->nullFieldOffsetIsZero() ? 0 : -1;
687 
688     VBTableOffset = -1;
689   }
690 
691   char Code = '\0';
692   switch (IM) {
693   case MSInheritanceModel::Single:      Code = '0'; break;
694   case MSInheritanceModel::Multiple:    Code = '0'; break;
695   case MSInheritanceModel::Virtual:     Code = 'F'; break;
696   case MSInheritanceModel::Unspecified: Code = 'G'; break;
697   }
698 
699   Out << Prefix << Code;
700 
701   mangleNumber(FieldOffset);
702 
703   // The C++ standard doesn't allow base-to-derived member pointer conversions
704   // in template parameter contexts, so the vbptr offset of data member pointers
705   // is always zero.
706   if (inheritanceModelHasVBPtrOffsetField(IM))
707     mangleNumber(0);
708   if (inheritanceModelHasVBTableOffsetField(IM))
709     mangleNumber(VBTableOffset);
710 }
711 
712 void
713 MicrosoftCXXNameMangler::mangleMemberFunctionPointer(const CXXRecordDecl *RD,
714                                                      const CXXMethodDecl *MD,
715                                                      StringRef Prefix) {
716   // <member-function-pointer> ::= $1? <name>
717   //                           ::= $H? <name> <number>
718   //                           ::= $I? <name> <number> <number>
719   //                           ::= $J? <name> <number> <number> <number>
720 
721   MSInheritanceModel IM = RD->getMSInheritanceModel();
722 
723   char Code = '\0';
724   switch (IM) {
725   case MSInheritanceModel::Single:      Code = '1'; break;
726   case MSInheritanceModel::Multiple:    Code = 'H'; break;
727   case MSInheritanceModel::Virtual:     Code = 'I'; break;
728   case MSInheritanceModel::Unspecified: Code = 'J'; break;
729   }
730 
731   // If non-virtual, mangle the name.  If virtual, mangle as a virtual memptr
732   // thunk.
733   uint64_t NVOffset = 0;
734   uint64_t VBTableOffset = 0;
735   uint64_t VBPtrOffset = 0;
736   if (MD) {
737     Out << Prefix << Code << '?';
738     if (MD->isVirtual()) {
739       MicrosoftVTableContext *VTContext =
740           cast<MicrosoftVTableContext>(getASTContext().getVTableContext());
741       MethodVFTableLocation ML =
742           VTContext->getMethodVFTableLocation(GlobalDecl(MD));
743       mangleVirtualMemPtrThunk(MD, ML);
744       NVOffset = ML.VFPtrOffset.getQuantity();
745       VBTableOffset = ML.VBTableIndex * 4;
746       if (ML.VBase) {
747         const ASTRecordLayout &Layout = getASTContext().getASTRecordLayout(RD);
748         VBPtrOffset = Layout.getVBPtrOffset().getQuantity();
749       }
750     } else {
751       mangleName(MD);
752       mangleFunctionEncoding(MD, /*ShouldMangle=*/true);
753     }
754 
755     if (VBTableOffset == 0 && IM == MSInheritanceModel::Virtual)
756       NVOffset -= getASTContext().getOffsetOfBaseWithVBPtr(RD).getQuantity();
757   } else {
758     // Null single inheritance member functions are encoded as a simple nullptr.
759     if (IM == MSInheritanceModel::Single) {
760       Out << Prefix << "0A@";
761       return;
762     }
763     if (IM == MSInheritanceModel::Unspecified)
764       VBTableOffset = -1;
765     Out << Prefix << Code;
766   }
767 
768   if (inheritanceModelHasNVOffsetField(/*IsMemberFunction=*/true, IM))
769     mangleNumber(static_cast<uint32_t>(NVOffset));
770   if (inheritanceModelHasVBPtrOffsetField(IM))
771     mangleNumber(VBPtrOffset);
772   if (inheritanceModelHasVBTableOffsetField(IM))
773     mangleNumber(VBTableOffset);
774 }
775 
776 void MicrosoftCXXNameMangler::mangleVirtualMemPtrThunk(
777     const CXXMethodDecl *MD, const MethodVFTableLocation &ML) {
778   // Get the vftable offset.
779   CharUnits PointerWidth = getASTContext().toCharUnitsFromBits(
780       getASTContext().getTargetInfo().getPointerWidth(LangAS::Default));
781   uint64_t OffsetInVFTable = ML.Index * PointerWidth.getQuantity();
782 
783   Out << "?_9";
784   mangleName(MD->getParent());
785   Out << "$B";
786   mangleNumber(OffsetInVFTable);
787   Out << 'A';
788   mangleCallingConvention(MD->getType()->castAs<FunctionProtoType>());
789 }
790 
791 void MicrosoftCXXNameMangler::mangleName(GlobalDecl GD) {
792   // <name> ::= <unscoped-name> {[<named-scope>]+ | [<nested-name>]}? @
793 
794   // Always start with the unqualified name.
795   mangleUnqualifiedName(GD);
796 
797   mangleNestedName(GD);
798 
799   // Terminate the whole name with an '@'.
800   Out << '@';
801 }
802 
803 void MicrosoftCXXNameMangler::mangleNumber(int64_t Number) {
804   mangleNumber(llvm::APSInt(llvm::APInt(64, Number), /*IsUnsigned*/false));
805 }
806 
807 void MicrosoftCXXNameMangler::mangleNumber(llvm::APSInt Number) {
808   // MSVC never mangles any integer wider than 64 bits. In general it appears
809   // to convert every integer to signed 64 bit before mangling (including
810   // unsigned 64 bit values). Do the same, but preserve bits beyond the bottom
811   // 64.
812   unsigned Width = std::max(Number.getBitWidth(), 64U);
813   llvm::APInt Value = Number.extend(Width);
814 
815   // <non-negative integer> ::= A@              # when Number == 0
816   //                        ::= <decimal digit> # when 1 <= Number <= 10
817   //                        ::= <hex digit>+ @  # when Number >= 10
818   //
819   // <number>               ::= [?] <non-negative integer>
820 
821   if (Value.isNegative()) {
822     Value = -Value;
823     Out << '?';
824   }
825   mangleBits(Value);
826 }
827 
828 void MicrosoftCXXNameMangler::mangleFloat(llvm::APFloat Number) {
829   using llvm::APFloat;
830 
831   switch (APFloat::SemanticsToEnum(Number.getSemantics())) {
832   case APFloat::S_IEEEsingle: Out << 'A'; break;
833   case APFloat::S_IEEEdouble: Out << 'B'; break;
834 
835   // The following are all Clang extensions. We try to pick manglings that are
836   // unlikely to conflict with MSVC's scheme.
837   case APFloat::S_IEEEhalf: Out << 'V'; break;
838   case APFloat::S_BFloat: Out << 'W'; break;
839   case APFloat::S_x87DoubleExtended: Out << 'X'; break;
840   case APFloat::S_IEEEquad: Out << 'Y'; break;
841   case APFloat::S_PPCDoubleDouble: Out << 'Z'; break;
842   case APFloat::S_Float8E5M2:
843   case APFloat::S_Float8E4M3FN:
844     llvm_unreachable("Tried to mangle unexpected APFloat semantics");
845   }
846 
847   mangleBits(Number.bitcastToAPInt());
848 }
849 
850 void MicrosoftCXXNameMangler::mangleBits(llvm::APInt Value) {
851   if (Value == 0)
852     Out << "A@";
853   else if (Value.uge(1) && Value.ule(10))
854     Out << (Value - 1);
855   else {
856     // Numbers that are not encoded as decimal digits are represented as nibbles
857     // in the range of ASCII characters 'A' to 'P'.
858     // The number 0x123450 would be encoded as 'BCDEFA'
859     llvm::SmallString<32> EncodedNumberBuffer;
860     for (; Value != 0; Value.lshrInPlace(4))
861       EncodedNumberBuffer.push_back('A' + (Value & 0xf).getZExtValue());
862     std::reverse(EncodedNumberBuffer.begin(), EncodedNumberBuffer.end());
863     Out.write(EncodedNumberBuffer.data(), EncodedNumberBuffer.size());
864     Out << '@';
865   }
866 }
867 
868 static GlobalDecl isTemplate(GlobalDecl GD,
869                              const TemplateArgumentList *&TemplateArgs) {
870   const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
871   // Check if we have a function template.
872   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
873     if (const TemplateDecl *TD = FD->getPrimaryTemplate()) {
874       TemplateArgs = FD->getTemplateSpecializationArgs();
875       return GD.getWithDecl(TD);
876     }
877   }
878 
879   // Check if we have a class template.
880   if (const ClassTemplateSpecializationDecl *Spec =
881           dyn_cast<ClassTemplateSpecializationDecl>(ND)) {
882     TemplateArgs = &Spec->getTemplateArgs();
883     return GD.getWithDecl(Spec->getSpecializedTemplate());
884   }
885 
886   // Check if we have a variable template.
887   if (const VarTemplateSpecializationDecl *Spec =
888           dyn_cast<VarTemplateSpecializationDecl>(ND)) {
889     TemplateArgs = &Spec->getTemplateArgs();
890     return GD.getWithDecl(Spec->getSpecializedTemplate());
891   }
892 
893   return GlobalDecl();
894 }
895 
896 void MicrosoftCXXNameMangler::mangleUnqualifiedName(GlobalDecl GD,
897                                                     DeclarationName Name) {
898   const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
899   //  <unqualified-name> ::= <operator-name>
900   //                     ::= <ctor-dtor-name>
901   //                     ::= <source-name>
902   //                     ::= <template-name>
903 
904   // Check if we have a template.
905   const TemplateArgumentList *TemplateArgs = nullptr;
906   if (GlobalDecl TD = isTemplate(GD, TemplateArgs)) {
907     // Function templates aren't considered for name back referencing.  This
908     // makes sense since function templates aren't likely to occur multiple
909     // times in a symbol.
910     if (isa<FunctionTemplateDecl>(TD.getDecl())) {
911       mangleTemplateInstantiationName(TD, *TemplateArgs);
912       Out << '@';
913       return;
914     }
915 
916     // Here comes the tricky thing: if we need to mangle something like
917     //   void foo(A::X<Y>, B::X<Y>),
918     // the X<Y> part is aliased. However, if you need to mangle
919     //   void foo(A::X<A::Y>, A::X<B::Y>),
920     // the A::X<> part is not aliased.
921     // That is, from the mangler's perspective we have a structure like this:
922     //   namespace[s] -> type[ -> template-parameters]
923     // but from the Clang perspective we have
924     //   type [ -> template-parameters]
925     //      \-> namespace[s]
926     // What we do is we create a new mangler, mangle the same type (without
927     // a namespace suffix) to a string using the extra mangler and then use
928     // the mangled type name as a key to check the mangling of different types
929     // for aliasing.
930 
931     // It's important to key cache reads off ND, not TD -- the same TD can
932     // be used with different TemplateArgs, but ND uniquely identifies
933     // TD / TemplateArg pairs.
934     ArgBackRefMap::iterator Found = TemplateArgBackReferences.find(ND);
935     if (Found == TemplateArgBackReferences.end()) {
936 
937       TemplateArgStringMap::iterator Found = TemplateArgStrings.find(ND);
938       if (Found == TemplateArgStrings.end()) {
939         // Mangle full template name into temporary buffer.
940         llvm::SmallString<64> TemplateMangling;
941         llvm::raw_svector_ostream Stream(TemplateMangling);
942         MicrosoftCXXNameMangler Extra(Context, Stream);
943         Extra.mangleTemplateInstantiationName(TD, *TemplateArgs);
944 
945         // Use the string backref vector to possibly get a back reference.
946         mangleSourceName(TemplateMangling);
947 
948         // Memoize back reference for this type if one exist, else memoize
949         // the mangling itself.
950         BackRefVec::iterator StringFound =
951             llvm::find(NameBackReferences, TemplateMangling);
952         if (StringFound != NameBackReferences.end()) {
953           TemplateArgBackReferences[ND] =
954               StringFound - NameBackReferences.begin();
955         } else {
956           TemplateArgStrings[ND] =
957               TemplateArgStringStorage.save(TemplateMangling.str());
958         }
959       } else {
960         Out << Found->second << '@'; // Outputs a StringRef.
961       }
962     } else {
963       Out << Found->second; // Outputs a back reference (an int).
964     }
965     return;
966   }
967 
968   switch (Name.getNameKind()) {
969     case DeclarationName::Identifier: {
970       if (const IdentifierInfo *II = Name.getAsIdentifierInfo()) {
971         bool IsDeviceStub =
972             ND &&
973             ((isa<FunctionDecl>(ND) && ND->hasAttr<CUDAGlobalAttr>()) ||
974              (isa<FunctionTemplateDecl>(ND) &&
975               cast<FunctionTemplateDecl>(ND)
976                   ->getTemplatedDecl()
977                   ->hasAttr<CUDAGlobalAttr>())) &&
978             GD.getKernelReferenceKind() == KernelReferenceKind::Stub;
979         if (IsDeviceStub)
980           mangleSourceName(
981               (llvm::Twine("__device_stub__") + II->getName()).str());
982         else
983           mangleSourceName(II->getName());
984         break;
985       }
986 
987       // Otherwise, an anonymous entity.  We must have a declaration.
988       assert(ND && "mangling empty name without declaration");
989 
990       if (const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(ND)) {
991         if (NS->isAnonymousNamespace()) {
992           Out << "?A0x" << Context.getAnonymousNamespaceHash() << '@';
993           break;
994         }
995       }
996 
997       if (const DecompositionDecl *DD = dyn_cast<DecompositionDecl>(ND)) {
998         // Decomposition declarations are considered anonymous, and get
999         // numbered with a $S prefix.
1000         llvm::SmallString<64> Name("$S");
1001         // Get a unique id for the anonymous struct.
1002         Name += llvm::utostr(Context.getAnonymousStructId(DD) + 1);
1003         mangleSourceName(Name);
1004         break;
1005       }
1006 
1007       if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
1008         // We must have an anonymous union or struct declaration.
1009         const CXXRecordDecl *RD = VD->getType()->getAsCXXRecordDecl();
1010         assert(RD && "expected variable decl to have a record type");
1011         // Anonymous types with no tag or typedef get the name of their
1012         // declarator mangled in.  If they have no declarator, number them with
1013         // a $S prefix.
1014         llvm::SmallString<64> Name("$S");
1015         // Get a unique id for the anonymous struct.
1016         Name += llvm::utostr(Context.getAnonymousStructId(RD) + 1);
1017         mangleSourceName(Name.str());
1018         break;
1019       }
1020 
1021       if (const MSGuidDecl *GD = dyn_cast<MSGuidDecl>(ND)) {
1022         // Mangle a GUID object as if it were a variable with the corresponding
1023         // mangled name.
1024         SmallString<sizeof("_GUID_12345678_1234_1234_1234_1234567890ab")> GUID;
1025         llvm::raw_svector_ostream GUIDOS(GUID);
1026         Context.mangleMSGuidDecl(GD, GUIDOS);
1027         mangleSourceName(GUID);
1028         break;
1029       }
1030 
1031       if (const auto *TPO = dyn_cast<TemplateParamObjectDecl>(ND)) {
1032         Out << "?__N";
1033         mangleTemplateArgValue(TPO->getType().getUnqualifiedType(),
1034                                TPO->getValue());
1035         break;
1036       }
1037 
1038       // We must have an anonymous struct.
1039       const TagDecl *TD = cast<TagDecl>(ND);
1040       if (const TypedefNameDecl *D = TD->getTypedefNameForAnonDecl()) {
1041         assert(TD->getDeclContext() == D->getDeclContext() &&
1042                "Typedef should not be in another decl context!");
1043         assert(D->getDeclName().getAsIdentifierInfo() &&
1044                "Typedef was not named!");
1045         mangleSourceName(D->getDeclName().getAsIdentifierInfo()->getName());
1046         break;
1047       }
1048 
1049       if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(TD)) {
1050         if (Record->isLambda()) {
1051           llvm::SmallString<10> Name("<lambda_");
1052 
1053           Decl *LambdaContextDecl = Record->getLambdaContextDecl();
1054           unsigned LambdaManglingNumber = Record->getLambdaManglingNumber();
1055           unsigned LambdaId;
1056           const ParmVarDecl *Parm =
1057               dyn_cast_or_null<ParmVarDecl>(LambdaContextDecl);
1058           const FunctionDecl *Func =
1059               Parm ? dyn_cast<FunctionDecl>(Parm->getDeclContext()) : nullptr;
1060 
1061           if (Func) {
1062             unsigned DefaultArgNo =
1063                 Func->getNumParams() - Parm->getFunctionScopeIndex();
1064             Name += llvm::utostr(DefaultArgNo);
1065             Name += "_";
1066           }
1067 
1068           if (LambdaManglingNumber)
1069             LambdaId = LambdaManglingNumber;
1070           else
1071             LambdaId = Context.getLambdaId(Record);
1072 
1073           Name += llvm::utostr(LambdaId);
1074           Name += ">";
1075 
1076           mangleSourceName(Name);
1077 
1078           // If the context is a variable or a class member and not a parameter,
1079           // it is encoded in a qualified name.
1080           if (LambdaManglingNumber && LambdaContextDecl) {
1081             if ((isa<VarDecl>(LambdaContextDecl) ||
1082                  isa<FieldDecl>(LambdaContextDecl)) &&
1083                 !isa<ParmVarDecl>(LambdaContextDecl)) {
1084               mangleUnqualifiedName(cast<NamedDecl>(LambdaContextDecl));
1085             }
1086           }
1087           break;
1088         }
1089       }
1090 
1091       llvm::SmallString<64> Name;
1092       if (DeclaratorDecl *DD =
1093               Context.getASTContext().getDeclaratorForUnnamedTagDecl(TD)) {
1094         // Anonymous types without a name for linkage purposes have their
1095         // declarator mangled in if they have one.
1096         Name += "<unnamed-type-";
1097         Name += DD->getName();
1098       } else if (TypedefNameDecl *TND =
1099                      Context.getASTContext().getTypedefNameForUnnamedTagDecl(
1100                          TD)) {
1101         // Anonymous types without a name for linkage purposes have their
1102         // associate typedef mangled in if they have one.
1103         Name += "<unnamed-type-";
1104         Name += TND->getName();
1105       } else if (isa<EnumDecl>(TD) &&
1106                  cast<EnumDecl>(TD)->enumerator_begin() !=
1107                      cast<EnumDecl>(TD)->enumerator_end()) {
1108         // Anonymous non-empty enums mangle in the first enumerator.
1109         auto *ED = cast<EnumDecl>(TD);
1110         Name += "<unnamed-enum-";
1111         Name += ED->enumerator_begin()->getName();
1112       } else {
1113         // Otherwise, number the types using a $S prefix.
1114         Name += "<unnamed-type-$S";
1115         Name += llvm::utostr(Context.getAnonymousStructId(TD) + 1);
1116       }
1117       Name += ">";
1118       mangleSourceName(Name.str());
1119       break;
1120     }
1121 
1122     case DeclarationName::ObjCZeroArgSelector:
1123     case DeclarationName::ObjCOneArgSelector:
1124     case DeclarationName::ObjCMultiArgSelector: {
1125       // This is reachable only when constructing an outlined SEH finally
1126       // block.  Nothing depends on this mangling and it's used only with
1127       // functinos with internal linkage.
1128       llvm::SmallString<64> Name;
1129       mangleSourceName(Name.str());
1130       break;
1131     }
1132 
1133     case DeclarationName::CXXConstructorName:
1134       if (isStructorDecl(ND)) {
1135         if (StructorType == Ctor_CopyingClosure) {
1136           Out << "?_O";
1137           return;
1138         }
1139         if (StructorType == Ctor_DefaultClosure) {
1140           Out << "?_F";
1141           return;
1142         }
1143       }
1144       Out << "?0";
1145       return;
1146 
1147     case DeclarationName::CXXDestructorName:
1148       if (isStructorDecl(ND))
1149         // If the named decl is the C++ destructor we're mangling,
1150         // use the type we were given.
1151         mangleCXXDtorType(static_cast<CXXDtorType>(StructorType));
1152       else
1153         // Otherwise, use the base destructor name. This is relevant if a
1154         // class with a destructor is declared within a destructor.
1155         mangleCXXDtorType(Dtor_Base);
1156       break;
1157 
1158     case DeclarationName::CXXConversionFunctionName:
1159       // <operator-name> ::= ?B # (cast)
1160       // The target type is encoded as the return type.
1161       Out << "?B";
1162       break;
1163 
1164     case DeclarationName::CXXOperatorName:
1165       mangleOperatorName(Name.getCXXOverloadedOperator(), ND->getLocation());
1166       break;
1167 
1168     case DeclarationName::CXXLiteralOperatorName: {
1169       Out << "?__K";
1170       mangleSourceName(Name.getCXXLiteralIdentifier()->getName());
1171       break;
1172     }
1173 
1174     case DeclarationName::CXXDeductionGuideName:
1175       llvm_unreachable("Can't mangle a deduction guide name!");
1176 
1177     case DeclarationName::CXXUsingDirective:
1178       llvm_unreachable("Can't mangle a using directive name!");
1179   }
1180 }
1181 
1182 // <postfix> ::= <unqualified-name> [<postfix>]
1183 //           ::= <substitution> [<postfix>]
1184 void MicrosoftCXXNameMangler::mangleNestedName(GlobalDecl GD) {
1185   const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
1186   const DeclContext *DC = getEffectiveDeclContext(ND);
1187   while (!DC->isTranslationUnit()) {
1188     if (isa<TagDecl>(ND) || isa<VarDecl>(ND)) {
1189       unsigned Disc;
1190       if (Context.getNextDiscriminator(ND, Disc)) {
1191         Out << '?';
1192         mangleNumber(Disc);
1193         Out << '?';
1194       }
1195     }
1196 
1197     if (const BlockDecl *BD = dyn_cast<BlockDecl>(DC)) {
1198       auto Discriminate =
1199           [](StringRef Name, const unsigned Discriminator,
1200              const unsigned ParameterDiscriminator) -> std::string {
1201         std::string Buffer;
1202         llvm::raw_string_ostream Stream(Buffer);
1203         Stream << Name;
1204         if (Discriminator)
1205           Stream << '_' << Discriminator;
1206         if (ParameterDiscriminator)
1207           Stream << '_' << ParameterDiscriminator;
1208         return Stream.str();
1209       };
1210 
1211       unsigned Discriminator = BD->getBlockManglingNumber();
1212       if (!Discriminator)
1213         Discriminator = Context.getBlockId(BD, /*Local=*/false);
1214 
1215       // Mangle the parameter position as a discriminator to deal with unnamed
1216       // parameters.  Rather than mangling the unqualified parameter name,
1217       // always use the position to give a uniform mangling.
1218       unsigned ParameterDiscriminator = 0;
1219       if (const auto *MC = BD->getBlockManglingContextDecl())
1220         if (const auto *P = dyn_cast<ParmVarDecl>(MC))
1221           if (const auto *F = dyn_cast<FunctionDecl>(P->getDeclContext()))
1222             ParameterDiscriminator =
1223                 F->getNumParams() - P->getFunctionScopeIndex();
1224 
1225       DC = getEffectiveDeclContext(BD);
1226 
1227       Out << '?';
1228       mangleSourceName(Discriminate("_block_invoke", Discriminator,
1229                                     ParameterDiscriminator));
1230       // If we have a block mangling context, encode that now.  This allows us
1231       // to discriminate between named static data initializers in the same
1232       // scope.  This is handled differently from parameters, which use
1233       // positions to discriminate between multiple instances.
1234       if (const auto *MC = BD->getBlockManglingContextDecl())
1235         if (!isa<ParmVarDecl>(MC))
1236           if (const auto *ND = dyn_cast<NamedDecl>(MC))
1237             mangleUnqualifiedName(ND);
1238       // MS ABI and Itanium manglings are in inverted scopes.  In the case of a
1239       // RecordDecl, mangle the entire scope hierarchy at this point rather than
1240       // just the unqualified name to get the ordering correct.
1241       if (const auto *RD = dyn_cast<RecordDecl>(DC))
1242         mangleName(RD);
1243       else
1244         Out << '@';
1245       // void __cdecl
1246       Out << "YAX";
1247       // struct __block_literal *
1248       Out << 'P';
1249       // __ptr64
1250       if (PointersAre64Bit)
1251         Out << 'E';
1252       Out << 'A';
1253       mangleArtificialTagType(TTK_Struct,
1254                              Discriminate("__block_literal", Discriminator,
1255                                           ParameterDiscriminator));
1256       Out << "@Z";
1257 
1258       // If the effective context was a Record, we have fully mangled the
1259       // qualified name and do not need to continue.
1260       if (isa<RecordDecl>(DC))
1261         break;
1262       continue;
1263     } else if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC)) {
1264       mangleObjCMethodName(Method);
1265     } else if (isa<NamedDecl>(DC)) {
1266       ND = cast<NamedDecl>(DC);
1267       if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
1268         mangle(getGlobalDeclAsDeclContext(FD), "?");
1269         break;
1270       } else {
1271         mangleUnqualifiedName(ND);
1272         // Lambdas in default arguments conceptually belong to the function the
1273         // parameter corresponds to.
1274         if (const auto *LDADC = getLambdaDefaultArgumentDeclContext(ND)) {
1275           DC = LDADC;
1276           continue;
1277         }
1278       }
1279     }
1280     DC = DC->getParent();
1281   }
1282 }
1283 
1284 void MicrosoftCXXNameMangler::mangleCXXDtorType(CXXDtorType T) {
1285   // Microsoft uses the names on the case labels for these dtor variants.  Clang
1286   // uses the Itanium terminology internally.  Everything in this ABI delegates
1287   // towards the base dtor.
1288   switch (T) {
1289   // <operator-name> ::= ?1  # destructor
1290   case Dtor_Base: Out << "?1"; return;
1291   // <operator-name> ::= ?_D # vbase destructor
1292   case Dtor_Complete: Out << "?_D"; return;
1293   // <operator-name> ::= ?_G # scalar deleting destructor
1294   case Dtor_Deleting: Out << "?_G"; return;
1295   // <operator-name> ::= ?_E # vector deleting destructor
1296   // FIXME: Add a vector deleting dtor type.  It goes in the vtable, so we need
1297   // it.
1298   case Dtor_Comdat:
1299     llvm_unreachable("not expecting a COMDAT");
1300   }
1301   llvm_unreachable("Unsupported dtor type?");
1302 }
1303 
1304 void MicrosoftCXXNameMangler::mangleOperatorName(OverloadedOperatorKind OO,
1305                                                  SourceLocation Loc) {
1306   switch (OO) {
1307   //                     ?0 # constructor
1308   //                     ?1 # destructor
1309   // <operator-name> ::= ?2 # new
1310   case OO_New: Out << "?2"; break;
1311   // <operator-name> ::= ?3 # delete
1312   case OO_Delete: Out << "?3"; break;
1313   // <operator-name> ::= ?4 # =
1314   case OO_Equal: Out << "?4"; break;
1315   // <operator-name> ::= ?5 # >>
1316   case OO_GreaterGreater: Out << "?5"; break;
1317   // <operator-name> ::= ?6 # <<
1318   case OO_LessLess: Out << "?6"; break;
1319   // <operator-name> ::= ?7 # !
1320   case OO_Exclaim: Out << "?7"; break;
1321   // <operator-name> ::= ?8 # ==
1322   case OO_EqualEqual: Out << "?8"; break;
1323   // <operator-name> ::= ?9 # !=
1324   case OO_ExclaimEqual: Out << "?9"; break;
1325   // <operator-name> ::= ?A # []
1326   case OO_Subscript: Out << "?A"; break;
1327   //                     ?B # conversion
1328   // <operator-name> ::= ?C # ->
1329   case OO_Arrow: Out << "?C"; break;
1330   // <operator-name> ::= ?D # *
1331   case OO_Star: Out << "?D"; break;
1332   // <operator-name> ::= ?E # ++
1333   case OO_PlusPlus: Out << "?E"; break;
1334   // <operator-name> ::= ?F # --
1335   case OO_MinusMinus: Out << "?F"; break;
1336   // <operator-name> ::= ?G # -
1337   case OO_Minus: Out << "?G"; break;
1338   // <operator-name> ::= ?H # +
1339   case OO_Plus: Out << "?H"; break;
1340   // <operator-name> ::= ?I # &
1341   case OO_Amp: Out << "?I"; break;
1342   // <operator-name> ::= ?J # ->*
1343   case OO_ArrowStar: Out << "?J"; break;
1344   // <operator-name> ::= ?K # /
1345   case OO_Slash: Out << "?K"; break;
1346   // <operator-name> ::= ?L # %
1347   case OO_Percent: Out << "?L"; break;
1348   // <operator-name> ::= ?M # <
1349   case OO_Less: Out << "?M"; break;
1350   // <operator-name> ::= ?N # <=
1351   case OO_LessEqual: Out << "?N"; break;
1352   // <operator-name> ::= ?O # >
1353   case OO_Greater: Out << "?O"; break;
1354   // <operator-name> ::= ?P # >=
1355   case OO_GreaterEqual: Out << "?P"; break;
1356   // <operator-name> ::= ?Q # ,
1357   case OO_Comma: Out << "?Q"; break;
1358   // <operator-name> ::= ?R # ()
1359   case OO_Call: Out << "?R"; break;
1360   // <operator-name> ::= ?S # ~
1361   case OO_Tilde: Out << "?S"; break;
1362   // <operator-name> ::= ?T # ^
1363   case OO_Caret: Out << "?T"; break;
1364   // <operator-name> ::= ?U # |
1365   case OO_Pipe: Out << "?U"; break;
1366   // <operator-name> ::= ?V # &&
1367   case OO_AmpAmp: Out << "?V"; break;
1368   // <operator-name> ::= ?W # ||
1369   case OO_PipePipe: Out << "?W"; break;
1370   // <operator-name> ::= ?X # *=
1371   case OO_StarEqual: Out << "?X"; break;
1372   // <operator-name> ::= ?Y # +=
1373   case OO_PlusEqual: Out << "?Y"; break;
1374   // <operator-name> ::= ?Z # -=
1375   case OO_MinusEqual: Out << "?Z"; break;
1376   // <operator-name> ::= ?_0 # /=
1377   case OO_SlashEqual: Out << "?_0"; break;
1378   // <operator-name> ::= ?_1 # %=
1379   case OO_PercentEqual: Out << "?_1"; break;
1380   // <operator-name> ::= ?_2 # >>=
1381   case OO_GreaterGreaterEqual: Out << "?_2"; break;
1382   // <operator-name> ::= ?_3 # <<=
1383   case OO_LessLessEqual: Out << "?_3"; break;
1384   // <operator-name> ::= ?_4 # &=
1385   case OO_AmpEqual: Out << "?_4"; break;
1386   // <operator-name> ::= ?_5 # |=
1387   case OO_PipeEqual: Out << "?_5"; break;
1388   // <operator-name> ::= ?_6 # ^=
1389   case OO_CaretEqual: Out << "?_6"; break;
1390   //                     ?_7 # vftable
1391   //                     ?_8 # vbtable
1392   //                     ?_9 # vcall
1393   //                     ?_A # typeof
1394   //                     ?_B # local static guard
1395   //                     ?_C # string
1396   //                     ?_D # vbase destructor
1397   //                     ?_E # vector deleting destructor
1398   //                     ?_F # default constructor closure
1399   //                     ?_G # scalar deleting destructor
1400   //                     ?_H # vector constructor iterator
1401   //                     ?_I # vector destructor iterator
1402   //                     ?_J # vector vbase constructor iterator
1403   //                     ?_K # virtual displacement map
1404   //                     ?_L # eh vector constructor iterator
1405   //                     ?_M # eh vector destructor iterator
1406   //                     ?_N # eh vector vbase constructor iterator
1407   //                     ?_O # copy constructor closure
1408   //                     ?_P<name> # udt returning <name>
1409   //                     ?_Q # <unknown>
1410   //                     ?_R0 # RTTI Type Descriptor
1411   //                     ?_R1 # RTTI Base Class Descriptor at (a,b,c,d)
1412   //                     ?_R2 # RTTI Base Class Array
1413   //                     ?_R3 # RTTI Class Hierarchy Descriptor
1414   //                     ?_R4 # RTTI Complete Object Locator
1415   //                     ?_S # local vftable
1416   //                     ?_T # local vftable constructor closure
1417   // <operator-name> ::= ?_U # new[]
1418   case OO_Array_New: Out << "?_U"; break;
1419   // <operator-name> ::= ?_V # delete[]
1420   case OO_Array_Delete: Out << "?_V"; break;
1421   // <operator-name> ::= ?__L # co_await
1422   case OO_Coawait: Out << "?__L"; break;
1423   // <operator-name> ::= ?__M # <=>
1424   case OO_Spaceship: Out << "?__M"; break;
1425 
1426   case OO_Conditional: {
1427     DiagnosticsEngine &Diags = Context.getDiags();
1428     unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
1429       "cannot mangle this conditional operator yet");
1430     Diags.Report(Loc, DiagID);
1431     break;
1432   }
1433 
1434   case OO_None:
1435   case NUM_OVERLOADED_OPERATORS:
1436     llvm_unreachable("Not an overloaded operator");
1437   }
1438 }
1439 
1440 void MicrosoftCXXNameMangler::mangleSourceName(StringRef Name) {
1441   // <source name> ::= <identifier> @
1442   BackRefVec::iterator Found = llvm::find(NameBackReferences, Name);
1443   if (Found == NameBackReferences.end()) {
1444     if (NameBackReferences.size() < 10)
1445       NameBackReferences.push_back(std::string(Name));
1446     Out << Name << '@';
1447   } else {
1448     Out << (Found - NameBackReferences.begin());
1449   }
1450 }
1451 
1452 void MicrosoftCXXNameMangler::mangleObjCMethodName(const ObjCMethodDecl *MD) {
1453   Context.mangleObjCMethodNameAsSourceName(MD, Out);
1454 }
1455 
1456 void MicrosoftCXXNameMangler::mangleTemplateInstantiationName(
1457     GlobalDecl GD, const TemplateArgumentList &TemplateArgs) {
1458   // <template-name> ::= <unscoped-template-name> <template-args>
1459   //                 ::= <substitution>
1460   // Always start with the unqualified name.
1461 
1462   // Templates have their own context for back references.
1463   ArgBackRefMap OuterFunArgsContext;
1464   ArgBackRefMap OuterTemplateArgsContext;
1465   BackRefVec OuterTemplateContext;
1466   PassObjectSizeArgsSet OuterPassObjectSizeArgs;
1467   NameBackReferences.swap(OuterTemplateContext);
1468   FunArgBackReferences.swap(OuterFunArgsContext);
1469   TemplateArgBackReferences.swap(OuterTemplateArgsContext);
1470   PassObjectSizeArgs.swap(OuterPassObjectSizeArgs);
1471 
1472   mangleUnscopedTemplateName(GD);
1473   mangleTemplateArgs(cast<TemplateDecl>(GD.getDecl()), TemplateArgs);
1474 
1475   // Restore the previous back reference contexts.
1476   NameBackReferences.swap(OuterTemplateContext);
1477   FunArgBackReferences.swap(OuterFunArgsContext);
1478   TemplateArgBackReferences.swap(OuterTemplateArgsContext);
1479   PassObjectSizeArgs.swap(OuterPassObjectSizeArgs);
1480 }
1481 
1482 void MicrosoftCXXNameMangler::mangleUnscopedTemplateName(GlobalDecl GD) {
1483   // <unscoped-template-name> ::= ?$ <unqualified-name>
1484   Out << "?$";
1485   mangleUnqualifiedName(GD);
1486 }
1487 
1488 void MicrosoftCXXNameMangler::mangleIntegerLiteral(
1489     const llvm::APSInt &Value, const NonTypeTemplateParmDecl *PD,
1490     QualType TemplateArgType) {
1491   // <integer-literal> ::= $0 <number>
1492   Out << "$";
1493 
1494   // Since MSVC 2019, add 'M[<type>]' after '$' for auto template parameter when
1495   // argument is integer.
1496   if (getASTContext().getLangOpts().isCompatibleWithMSVC(
1497           LangOptions::MSVC2019) &&
1498       PD && PD->getType()->getTypeClass() == Type::Auto &&
1499       !TemplateArgType.isNull()) {
1500     Out << "M";
1501     mangleType(TemplateArgType, SourceRange(), QMM_Drop);
1502   }
1503 
1504   Out << "0";
1505 
1506   mangleNumber(Value);
1507 }
1508 
1509 void MicrosoftCXXNameMangler::mangleExpression(
1510     const Expr *E, const NonTypeTemplateParmDecl *PD) {
1511   // See if this is a constant expression.
1512   if (std::optional<llvm::APSInt> Value =
1513           E->getIntegerConstantExpr(Context.getASTContext())) {
1514     mangleIntegerLiteral(*Value, PD, E->getType());
1515     return;
1516   }
1517 
1518   // As bad as this diagnostic is, it's better than crashing.
1519   DiagnosticsEngine &Diags = Context.getDiags();
1520   unsigned DiagID = Diags.getCustomDiagID(
1521       DiagnosticsEngine::Error, "cannot yet mangle expression type %0");
1522   Diags.Report(E->getExprLoc(), DiagID) << E->getStmtClassName()
1523                                         << E->getSourceRange();
1524 }
1525 
1526 void MicrosoftCXXNameMangler::mangleTemplateArgs(
1527     const TemplateDecl *TD, const TemplateArgumentList &TemplateArgs) {
1528   // <template-args> ::= <template-arg>+
1529   const TemplateParameterList *TPL = TD->getTemplateParameters();
1530   assert(TPL->size() == TemplateArgs.size() &&
1531          "size mismatch between args and parms!");
1532 
1533   for (size_t i = 0; i < TemplateArgs.size(); ++i) {
1534     const TemplateArgument &TA = TemplateArgs[i];
1535 
1536     // Separate consecutive packs by $$Z.
1537     if (i > 0 && TA.getKind() == TemplateArgument::Pack &&
1538         TemplateArgs[i - 1].getKind() == TemplateArgument::Pack)
1539       Out << "$$Z";
1540 
1541     mangleTemplateArg(TD, TA, TPL->getParam(i));
1542   }
1543 }
1544 
1545 void MicrosoftCXXNameMangler::mangleTemplateArg(const TemplateDecl *TD,
1546                                                 const TemplateArgument &TA,
1547                                                 const NamedDecl *Parm) {
1548   // <template-arg> ::= <type>
1549   //                ::= <integer-literal>
1550   //                ::= <member-data-pointer>
1551   //                ::= <member-function-pointer>
1552   //                ::= $ <constant-value>
1553   //                ::= <template-args>
1554   //
1555   // <constant-value> ::= 0 <number>                   # integer
1556   //                  ::= 1 <mangled-name>             # address of D
1557   //                  ::= 2 <type> <typed-constant-value>* @ # struct
1558   //                  ::= 3 <type> <constant-value>* @ # array
1559   //                  ::= 4 ???                        # string
1560   //                  ::= 5 <constant-value> @         # address of subobject
1561   //                  ::= 6 <constant-value> <unqualified-name> @ # a.b
1562   //                  ::= 7 <type> [<unqualified-name> <constant-value>] @
1563   //                      # union, with or without an active member
1564   //                  # pointer to member, symbolically
1565   //                  ::= 8 <class> <unqualified-name> @
1566   //                  ::= A <type> <non-negative integer>  # float
1567   //                  ::= B <type> <non-negative integer>  # double
1568   //                  ::= E <mangled-name>             # reference to D
1569   //                  # pointer to member, by component value
1570   //                  ::= F <number> <number>
1571   //                  ::= G <number> <number> <number>
1572   //                  ::= H <mangled-name> <number>
1573   //                  ::= I <mangled-name> <number> <number>
1574   //                  ::= J <mangled-name> <number> <number> <number>
1575   //
1576   // <typed-constant-value> ::= [<type>] <constant-value>
1577   //
1578   // The <type> appears to be included in a <typed-constant-value> only in the
1579   // '0', '1', '8', 'A', 'B', and 'E' cases.
1580 
1581   switch (TA.getKind()) {
1582   case TemplateArgument::Null:
1583     llvm_unreachable("Can't mangle null template arguments!");
1584   case TemplateArgument::TemplateExpansion:
1585     llvm_unreachable("Can't mangle template expansion arguments!");
1586   case TemplateArgument::Type: {
1587     QualType T = TA.getAsType();
1588     mangleType(T, SourceRange(), QMM_Escape);
1589     break;
1590   }
1591   case TemplateArgument::Declaration: {
1592     const NamedDecl *ND = TA.getAsDecl();
1593     if (isa<FieldDecl>(ND) || isa<IndirectFieldDecl>(ND)) {
1594       mangleMemberDataPointer(cast<CXXRecordDecl>(ND->getDeclContext())
1595                                   ->getMostRecentNonInjectedDecl(),
1596                               cast<ValueDecl>(ND));
1597     } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
1598       const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
1599       if (MD && MD->isInstance()) {
1600         mangleMemberFunctionPointer(
1601             MD->getParent()->getMostRecentNonInjectedDecl(), MD);
1602       } else {
1603         Out << "$1?";
1604         mangleName(FD);
1605         mangleFunctionEncoding(FD, /*ShouldMangle=*/true);
1606       }
1607     } else if (TA.getParamTypeForDecl()->isRecordType()) {
1608       Out << "$";
1609       auto *TPO = cast<TemplateParamObjectDecl>(ND);
1610       mangleTemplateArgValue(TPO->getType().getUnqualifiedType(),
1611                              TPO->getValue());
1612     } else {
1613       mangle(ND, TA.getParamTypeForDecl()->isReferenceType() ? "$E?" : "$1?");
1614     }
1615     break;
1616   }
1617   case TemplateArgument::Integral: {
1618     QualType T = TA.getIntegralType();
1619     mangleIntegerLiteral(TA.getAsIntegral(),
1620                          cast<NonTypeTemplateParmDecl>(Parm), T);
1621     break;
1622   }
1623   case TemplateArgument::NullPtr: {
1624     QualType T = TA.getNullPtrType();
1625     if (const MemberPointerType *MPT = T->getAs<MemberPointerType>()) {
1626       const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
1627       if (MPT->isMemberFunctionPointerType() &&
1628           !isa<FunctionTemplateDecl>(TD)) {
1629         mangleMemberFunctionPointer(RD, nullptr);
1630         return;
1631       }
1632       if (MPT->isMemberDataPointer()) {
1633         if (!isa<FunctionTemplateDecl>(TD)) {
1634           mangleMemberDataPointer(RD, nullptr);
1635           return;
1636         }
1637         // nullptr data pointers are always represented with a single field
1638         // which is initialized with either 0 or -1.  Why -1?  Well, we need to
1639         // distinguish the case where the data member is at offset zero in the
1640         // record.
1641         // However, we are free to use 0 *if* we would use multiple fields for
1642         // non-nullptr member pointers.
1643         if (!RD->nullFieldOffsetIsZero()) {
1644           mangleIntegerLiteral(llvm::APSInt::get(-1),
1645                                cast<NonTypeTemplateParmDecl>(Parm), T);
1646           return;
1647         }
1648       }
1649     }
1650     mangleIntegerLiteral(llvm::APSInt::getUnsigned(0),
1651                          cast<NonTypeTemplateParmDecl>(Parm), T);
1652     break;
1653   }
1654   case TemplateArgument::Expression:
1655     mangleExpression(TA.getAsExpr(), cast<NonTypeTemplateParmDecl>(Parm));
1656     break;
1657   case TemplateArgument::Pack: {
1658     ArrayRef<TemplateArgument> TemplateArgs = TA.getPackAsArray();
1659     if (TemplateArgs.empty()) {
1660       if (isa<TemplateTypeParmDecl>(Parm) ||
1661           isa<TemplateTemplateParmDecl>(Parm))
1662         // MSVC 2015 changed the mangling for empty expanded template packs,
1663         // use the old mangling for link compatibility for old versions.
1664         Out << (Context.getASTContext().getLangOpts().isCompatibleWithMSVC(
1665                     LangOptions::MSVC2015)
1666                     ? "$$V"
1667                     : "$$$V");
1668       else if (isa<NonTypeTemplateParmDecl>(Parm))
1669         Out << "$S";
1670       else
1671         llvm_unreachable("unexpected template parameter decl!");
1672     } else {
1673       for (const TemplateArgument &PA : TemplateArgs)
1674         mangleTemplateArg(TD, PA, Parm);
1675     }
1676     break;
1677   }
1678   case TemplateArgument::Template: {
1679     const NamedDecl *ND =
1680         TA.getAsTemplate().getAsTemplateDecl()->getTemplatedDecl();
1681     if (const auto *TD = dyn_cast<TagDecl>(ND)) {
1682       mangleType(TD);
1683     } else if (isa<TypeAliasDecl>(ND)) {
1684       Out << "$$Y";
1685       mangleName(ND);
1686     } else {
1687       llvm_unreachable("unexpected template template NamedDecl!");
1688     }
1689     break;
1690   }
1691   }
1692 }
1693 
1694 void MicrosoftCXXNameMangler::mangleTemplateArgValue(QualType T,
1695                                                      const APValue &V,
1696                                                      bool WithScalarType) {
1697   switch (V.getKind()) {
1698   case APValue::None:
1699   case APValue::Indeterminate:
1700     // FIXME: MSVC doesn't allow this, so we can't be sure how it should be
1701     // mangled.
1702     if (WithScalarType)
1703       mangleType(T, SourceRange(), QMM_Escape);
1704     Out << '@';
1705     return;
1706 
1707   case APValue::Int:
1708     if (WithScalarType)
1709       mangleType(T, SourceRange(), QMM_Escape);
1710     Out << '0';
1711     mangleNumber(V.getInt());
1712     return;
1713 
1714   case APValue::Float:
1715     if (WithScalarType)
1716       mangleType(T, SourceRange(), QMM_Escape);
1717     mangleFloat(V.getFloat());
1718     return;
1719 
1720   case APValue::LValue: {
1721     if (WithScalarType)
1722       mangleType(T, SourceRange(), QMM_Escape);
1723 
1724     // We don't know how to mangle past-the-end pointers yet.
1725     if (V.isLValueOnePastTheEnd())
1726       break;
1727 
1728     APValue::LValueBase Base = V.getLValueBase();
1729     if (!V.hasLValuePath() || V.getLValuePath().empty()) {
1730       // Taking the address of a complete object has a special-case mangling.
1731       if (Base.isNull()) {
1732         // MSVC emits 0A@ for null pointers. Generalize this for arbitrary
1733         // integers cast to pointers.
1734         // FIXME: This mangles 0 cast to a pointer the same as a null pointer,
1735         // even in cases where the two are different values.
1736         Out << "0";
1737         mangleNumber(V.getLValueOffset().getQuantity());
1738       } else if (!V.hasLValuePath()) {
1739         // FIXME: This can only happen as an extension. Invent a mangling.
1740         break;
1741       } else if (auto *VD = Base.dyn_cast<const ValueDecl*>()) {
1742         Out << (T->isReferenceType() ? "E" : "1");
1743         mangle(VD);
1744       } else {
1745         break;
1746       }
1747     } else {
1748       unsigned NumAts = 0;
1749       if (T->isPointerType()) {
1750         Out << "5";
1751         ++NumAts;
1752       }
1753 
1754       QualType T = Base.getType();
1755       for (APValue::LValuePathEntry E : V.getLValuePath()) {
1756         // We don't know how to mangle array subscripting yet.
1757         if (T->isArrayType())
1758           goto mangling_unknown;
1759 
1760         const Decl *D = E.getAsBaseOrMember().getPointer();
1761         auto *FD = dyn_cast<FieldDecl>(D);
1762         // We don't know how to mangle derived-to-base conversions yet.
1763         if (!FD)
1764           goto mangling_unknown;
1765 
1766         Out << "6";
1767         ++NumAts;
1768         T = FD->getType();
1769       }
1770 
1771       auto *VD = Base.dyn_cast<const ValueDecl*>();
1772       if (!VD)
1773         break;
1774       Out << "E";
1775       mangle(VD);
1776 
1777       for (APValue::LValuePathEntry E : V.getLValuePath()) {
1778         const Decl *D = E.getAsBaseOrMember().getPointer();
1779         mangleUnqualifiedName(cast<FieldDecl>(D));
1780       }
1781       for (unsigned I = 0; I != NumAts; ++I)
1782         Out << '@';
1783     }
1784 
1785     return;
1786   }
1787 
1788   case APValue::MemberPointer: {
1789     if (WithScalarType)
1790       mangleType(T, SourceRange(), QMM_Escape);
1791 
1792     // FIXME: The below manglings don't include a conversion, so bail if there
1793     // would be one. MSVC mangles the (possibly converted) value of the
1794     // pointer-to-member object as if it were a struct, leading to collisions
1795     // in some cases.
1796     if (!V.getMemberPointerPath().empty())
1797       break;
1798 
1799     const CXXRecordDecl *RD =
1800         T->castAs<MemberPointerType>()->getMostRecentCXXRecordDecl();
1801     const ValueDecl *D = V.getMemberPointerDecl();
1802     if (T->isMemberDataPointerType())
1803       mangleMemberDataPointer(RD, D, "");
1804     else
1805       mangleMemberFunctionPointer(RD, cast_or_null<CXXMethodDecl>(D), "");
1806     return;
1807   }
1808 
1809   case APValue::Struct: {
1810     Out << '2';
1811     mangleType(T, SourceRange(), QMM_Escape);
1812     const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
1813     assert(RD && "unexpected type for record value");
1814 
1815     unsigned BaseIndex = 0;
1816     for (const CXXBaseSpecifier &B : RD->bases())
1817       mangleTemplateArgValue(B.getType(), V.getStructBase(BaseIndex++));
1818     for (const FieldDecl *FD : RD->fields())
1819       if (!FD->isUnnamedBitfield())
1820         mangleTemplateArgValue(FD->getType(),
1821                                V.getStructField(FD->getFieldIndex()),
1822                                /*WithScalarType*/ true);
1823     Out << '@';
1824     return;
1825   }
1826 
1827   case APValue::Union:
1828     Out << '7';
1829     mangleType(T, SourceRange(), QMM_Escape);
1830     if (const FieldDecl *FD = V.getUnionField()) {
1831       mangleUnqualifiedName(FD);
1832       mangleTemplateArgValue(FD->getType(), V.getUnionValue());
1833     }
1834     Out << '@';
1835     return;
1836 
1837   case APValue::ComplexInt:
1838     // We mangle complex types as structs, so mangle the value as a struct too.
1839     Out << '2';
1840     mangleType(T, SourceRange(), QMM_Escape);
1841     Out << '0';
1842     mangleNumber(V.getComplexIntReal());
1843     Out << '0';
1844     mangleNumber(V.getComplexIntImag());
1845     Out << '@';
1846     return;
1847 
1848   case APValue::ComplexFloat:
1849     Out << '2';
1850     mangleType(T, SourceRange(), QMM_Escape);
1851     mangleFloat(V.getComplexFloatReal());
1852     mangleFloat(V.getComplexFloatImag());
1853     Out << '@';
1854     return;
1855 
1856   case APValue::Array: {
1857     Out << '3';
1858     QualType ElemT = getASTContext().getAsArrayType(T)->getElementType();
1859     mangleType(ElemT, SourceRange(), QMM_Escape);
1860     for (unsigned I = 0, N = V.getArraySize(); I != N; ++I) {
1861       const APValue &ElemV = I < V.getArrayInitializedElts()
1862                                  ? V.getArrayInitializedElt(I)
1863                                  : V.getArrayFiller();
1864       mangleTemplateArgValue(ElemT, ElemV);
1865       Out << '@';
1866     }
1867     Out << '@';
1868     return;
1869   }
1870 
1871   case APValue::Vector: {
1872     // __m128 is mangled as a struct containing an array. We follow this
1873     // approach for all vector types.
1874     Out << '2';
1875     mangleType(T, SourceRange(), QMM_Escape);
1876     Out << '3';
1877     QualType ElemT = T->castAs<VectorType>()->getElementType();
1878     mangleType(ElemT, SourceRange(), QMM_Escape);
1879     for (unsigned I = 0, N = V.getVectorLength(); I != N; ++I) {
1880       const APValue &ElemV = V.getVectorElt(I);
1881       mangleTemplateArgValue(ElemT, ElemV);
1882       Out << '@';
1883     }
1884     Out << "@@";
1885     return;
1886   }
1887 
1888   case APValue::AddrLabelDiff:
1889   case APValue::FixedPoint:
1890     break;
1891   }
1892 
1893 mangling_unknown:
1894   DiagnosticsEngine &Diags = Context.getDiags();
1895   unsigned DiagID = Diags.getCustomDiagID(
1896       DiagnosticsEngine::Error, "cannot mangle this template argument yet");
1897   Diags.Report(DiagID);
1898 }
1899 
1900 void MicrosoftCXXNameMangler::mangleObjCProtocol(const ObjCProtocolDecl *PD) {
1901   llvm::SmallString<64> TemplateMangling;
1902   llvm::raw_svector_ostream Stream(TemplateMangling);
1903   MicrosoftCXXNameMangler Extra(Context, Stream);
1904 
1905   Stream << "?$";
1906   Extra.mangleSourceName("Protocol");
1907   Extra.mangleArtificialTagType(TTK_Struct, PD->getName());
1908 
1909   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__ObjC"});
1910 }
1911 
1912 void MicrosoftCXXNameMangler::mangleObjCLifetime(const QualType Type,
1913                                                  Qualifiers Quals,
1914                                                  SourceRange Range) {
1915   llvm::SmallString<64> TemplateMangling;
1916   llvm::raw_svector_ostream Stream(TemplateMangling);
1917   MicrosoftCXXNameMangler Extra(Context, Stream);
1918 
1919   Stream << "?$";
1920   switch (Quals.getObjCLifetime()) {
1921   case Qualifiers::OCL_None:
1922   case Qualifiers::OCL_ExplicitNone:
1923     break;
1924   case Qualifiers::OCL_Autoreleasing:
1925     Extra.mangleSourceName("Autoreleasing");
1926     break;
1927   case Qualifiers::OCL_Strong:
1928     Extra.mangleSourceName("Strong");
1929     break;
1930   case Qualifiers::OCL_Weak:
1931     Extra.mangleSourceName("Weak");
1932     break;
1933   }
1934   Extra.manglePointerCVQualifiers(Quals);
1935   Extra.manglePointerExtQualifiers(Quals, Type);
1936   Extra.mangleType(Type, Range);
1937 
1938   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__ObjC"});
1939 }
1940 
1941 void MicrosoftCXXNameMangler::mangleObjCKindOfType(const ObjCObjectType *T,
1942                                                    Qualifiers Quals,
1943                                                    SourceRange Range) {
1944   llvm::SmallString<64> TemplateMangling;
1945   llvm::raw_svector_ostream Stream(TemplateMangling);
1946   MicrosoftCXXNameMangler Extra(Context, Stream);
1947 
1948   Stream << "?$";
1949   Extra.mangleSourceName("KindOf");
1950   Extra.mangleType(QualType(T, 0)
1951                        .stripObjCKindOfType(getASTContext())
1952                        ->castAs<ObjCObjectType>(),
1953                    Quals, Range);
1954 
1955   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__ObjC"});
1956 }
1957 
1958 void MicrosoftCXXNameMangler::mangleQualifiers(Qualifiers Quals,
1959                                                bool IsMember) {
1960   // <cvr-qualifiers> ::= [E] [F] [I] <base-cvr-qualifiers>
1961   // 'E' means __ptr64 (32-bit only); 'F' means __unaligned (32/64-bit only);
1962   // 'I' means __restrict (32/64-bit).
1963   // Note that the MSVC __restrict keyword isn't the same as the C99 restrict
1964   // keyword!
1965   // <base-cvr-qualifiers> ::= A  # near
1966   //                       ::= B  # near const
1967   //                       ::= C  # near volatile
1968   //                       ::= D  # near const volatile
1969   //                       ::= E  # far (16-bit)
1970   //                       ::= F  # far const (16-bit)
1971   //                       ::= G  # far volatile (16-bit)
1972   //                       ::= H  # far const volatile (16-bit)
1973   //                       ::= I  # huge (16-bit)
1974   //                       ::= J  # huge const (16-bit)
1975   //                       ::= K  # huge volatile (16-bit)
1976   //                       ::= L  # huge const volatile (16-bit)
1977   //                       ::= M <basis> # based
1978   //                       ::= N <basis> # based const
1979   //                       ::= O <basis> # based volatile
1980   //                       ::= P <basis> # based const volatile
1981   //                       ::= Q  # near member
1982   //                       ::= R  # near const member
1983   //                       ::= S  # near volatile member
1984   //                       ::= T  # near const volatile member
1985   //                       ::= U  # far member (16-bit)
1986   //                       ::= V  # far const member (16-bit)
1987   //                       ::= W  # far volatile member (16-bit)
1988   //                       ::= X  # far const volatile member (16-bit)
1989   //                       ::= Y  # huge member (16-bit)
1990   //                       ::= Z  # huge const member (16-bit)
1991   //                       ::= 0  # huge volatile member (16-bit)
1992   //                       ::= 1  # huge const volatile member (16-bit)
1993   //                       ::= 2 <basis> # based member
1994   //                       ::= 3 <basis> # based const member
1995   //                       ::= 4 <basis> # based volatile member
1996   //                       ::= 5 <basis> # based const volatile member
1997   //                       ::= 6  # near function (pointers only)
1998   //                       ::= 7  # far function (pointers only)
1999   //                       ::= 8  # near method (pointers only)
2000   //                       ::= 9  # far method (pointers only)
2001   //                       ::= _A <basis> # based function (pointers only)
2002   //                       ::= _B <basis> # based function (far?) (pointers only)
2003   //                       ::= _C <basis> # based method (pointers only)
2004   //                       ::= _D <basis> # based method (far?) (pointers only)
2005   //                       ::= _E # block (Clang)
2006   // <basis> ::= 0 # __based(void)
2007   //         ::= 1 # __based(segment)?
2008   //         ::= 2 <name> # __based(name)
2009   //         ::= 3 # ?
2010   //         ::= 4 # ?
2011   //         ::= 5 # not really based
2012   bool HasConst = Quals.hasConst(),
2013        HasVolatile = Quals.hasVolatile();
2014 
2015   if (!IsMember) {
2016     if (HasConst && HasVolatile) {
2017       Out << 'D';
2018     } else if (HasVolatile) {
2019       Out << 'C';
2020     } else if (HasConst) {
2021       Out << 'B';
2022     } else {
2023       Out << 'A';
2024     }
2025   } else {
2026     if (HasConst && HasVolatile) {
2027       Out << 'T';
2028     } else if (HasVolatile) {
2029       Out << 'S';
2030     } else if (HasConst) {
2031       Out << 'R';
2032     } else {
2033       Out << 'Q';
2034     }
2035   }
2036 
2037   // FIXME: For now, just drop all extension qualifiers on the floor.
2038 }
2039 
2040 void
2041 MicrosoftCXXNameMangler::mangleRefQualifier(RefQualifierKind RefQualifier) {
2042   // <ref-qualifier> ::= G                # lvalue reference
2043   //                 ::= H                # rvalue-reference
2044   switch (RefQualifier) {
2045   case RQ_None:
2046     break;
2047 
2048   case RQ_LValue:
2049     Out << 'G';
2050     break;
2051 
2052   case RQ_RValue:
2053     Out << 'H';
2054     break;
2055   }
2056 }
2057 
2058 void MicrosoftCXXNameMangler::manglePointerExtQualifiers(Qualifiers Quals,
2059                                                          QualType PointeeType) {
2060   // Check if this is a default 64-bit pointer or has __ptr64 qualifier.
2061   bool is64Bit = PointeeType.isNull() ? PointersAre64Bit :
2062       is64BitPointer(PointeeType.getQualifiers());
2063   if (is64Bit && (PointeeType.isNull() || !PointeeType->isFunctionType()))
2064     Out << 'E';
2065 
2066   if (Quals.hasRestrict())
2067     Out << 'I';
2068 
2069   if (Quals.hasUnaligned() ||
2070       (!PointeeType.isNull() && PointeeType.getLocalQualifiers().hasUnaligned()))
2071     Out << 'F';
2072 }
2073 
2074 void MicrosoftCXXNameMangler::manglePointerCVQualifiers(Qualifiers Quals) {
2075   // <pointer-cv-qualifiers> ::= P  # no qualifiers
2076   //                         ::= Q  # const
2077   //                         ::= R  # volatile
2078   //                         ::= S  # const volatile
2079   bool HasConst = Quals.hasConst(),
2080        HasVolatile = Quals.hasVolatile();
2081 
2082   if (HasConst && HasVolatile) {
2083     Out << 'S';
2084   } else if (HasVolatile) {
2085     Out << 'R';
2086   } else if (HasConst) {
2087     Out << 'Q';
2088   } else {
2089     Out << 'P';
2090   }
2091 }
2092 
2093 void MicrosoftCXXNameMangler::mangleFunctionArgumentType(QualType T,
2094                                                          SourceRange Range) {
2095   // MSVC will backreference two canonically equivalent types that have slightly
2096   // different manglings when mangled alone.
2097 
2098   // Decayed types do not match up with non-decayed versions of the same type.
2099   //
2100   // e.g.
2101   // void (*x)(void) will not form a backreference with void x(void)
2102   void *TypePtr;
2103   if (const auto *DT = T->getAs<DecayedType>()) {
2104     QualType OriginalType = DT->getOriginalType();
2105     // All decayed ArrayTypes should be treated identically; as-if they were
2106     // a decayed IncompleteArrayType.
2107     if (const auto *AT = getASTContext().getAsArrayType(OriginalType))
2108       OriginalType = getASTContext().getIncompleteArrayType(
2109           AT->getElementType(), AT->getSizeModifier(),
2110           AT->getIndexTypeCVRQualifiers());
2111 
2112     TypePtr = OriginalType.getCanonicalType().getAsOpaquePtr();
2113     // If the original parameter was textually written as an array,
2114     // instead treat the decayed parameter like it's const.
2115     //
2116     // e.g.
2117     // int [] -> int * const
2118     if (OriginalType->isArrayType())
2119       T = T.withConst();
2120   } else {
2121     TypePtr = T.getCanonicalType().getAsOpaquePtr();
2122   }
2123 
2124   ArgBackRefMap::iterator Found = FunArgBackReferences.find(TypePtr);
2125 
2126   if (Found == FunArgBackReferences.end()) {
2127     size_t OutSizeBefore = Out.tell();
2128 
2129     mangleType(T, Range, QMM_Drop);
2130 
2131     // See if it's worth creating a back reference.
2132     // Only types longer than 1 character are considered
2133     // and only 10 back references slots are available:
2134     bool LongerThanOneChar = (Out.tell() - OutSizeBefore > 1);
2135     if (LongerThanOneChar && FunArgBackReferences.size() < 10) {
2136       size_t Size = FunArgBackReferences.size();
2137       FunArgBackReferences[TypePtr] = Size;
2138     }
2139   } else {
2140     Out << Found->second;
2141   }
2142 }
2143 
2144 void MicrosoftCXXNameMangler::manglePassObjectSizeArg(
2145     const PassObjectSizeAttr *POSA) {
2146   int Type = POSA->getType();
2147   bool Dynamic = POSA->isDynamic();
2148 
2149   auto Iter = PassObjectSizeArgs.insert({Type, Dynamic}).first;
2150   auto *TypePtr = (const void *)&*Iter;
2151   ArgBackRefMap::iterator Found = FunArgBackReferences.find(TypePtr);
2152 
2153   if (Found == FunArgBackReferences.end()) {
2154     std::string Name =
2155         Dynamic ? "__pass_dynamic_object_size" : "__pass_object_size";
2156     mangleArtificialTagType(TTK_Enum, Name + llvm::utostr(Type), {"__clang"});
2157 
2158     if (FunArgBackReferences.size() < 10) {
2159       size_t Size = FunArgBackReferences.size();
2160       FunArgBackReferences[TypePtr] = Size;
2161     }
2162   } else {
2163     Out << Found->second;
2164   }
2165 }
2166 
2167 void MicrosoftCXXNameMangler::mangleAddressSpaceType(QualType T,
2168                                                      Qualifiers Quals,
2169                                                      SourceRange Range) {
2170   // Address space is mangled as an unqualified templated type in the __clang
2171   // namespace. The demangled version of this is:
2172   // In the case of a language specific address space:
2173   // __clang::struct _AS[language_addr_space]<Type>
2174   // where:
2175   //  <language_addr_space> ::= <OpenCL-addrspace> | <CUDA-addrspace>
2176   //    <OpenCL-addrspace> ::= "CL" [ "global" | "local" | "constant" |
2177   //                                "private"| "generic" | "device" | "host" ]
2178   //    <CUDA-addrspace> ::= "CU" [ "device" | "constant" | "shared" ]
2179   //    Note that the above were chosen to match the Itanium mangling for this.
2180   //
2181   // In the case of a non-language specific address space:
2182   //  __clang::struct _AS<TargetAS, Type>
2183   assert(Quals.hasAddressSpace() && "Not valid without address space");
2184   llvm::SmallString<32> ASMangling;
2185   llvm::raw_svector_ostream Stream(ASMangling);
2186   MicrosoftCXXNameMangler Extra(Context, Stream);
2187   Stream << "?$";
2188 
2189   LangAS AS = Quals.getAddressSpace();
2190   if (Context.getASTContext().addressSpaceMapManglingFor(AS)) {
2191     unsigned TargetAS = Context.getASTContext().getTargetAddressSpace(AS);
2192     Extra.mangleSourceName("_AS");
2193     Extra.mangleIntegerLiteral(llvm::APSInt::getUnsigned(TargetAS));
2194   } else {
2195     switch (AS) {
2196     default:
2197       llvm_unreachable("Not a language specific address space");
2198     case LangAS::opencl_global:
2199       Extra.mangleSourceName("_ASCLglobal");
2200       break;
2201     case LangAS::opencl_global_device:
2202       Extra.mangleSourceName("_ASCLdevice");
2203       break;
2204     case LangAS::opencl_global_host:
2205       Extra.mangleSourceName("_ASCLhost");
2206       break;
2207     case LangAS::opencl_local:
2208       Extra.mangleSourceName("_ASCLlocal");
2209       break;
2210     case LangAS::opencl_constant:
2211       Extra.mangleSourceName("_ASCLconstant");
2212       break;
2213     case LangAS::opencl_private:
2214       Extra.mangleSourceName("_ASCLprivate");
2215       break;
2216     case LangAS::opencl_generic:
2217       Extra.mangleSourceName("_ASCLgeneric");
2218       break;
2219     case LangAS::cuda_device:
2220       Extra.mangleSourceName("_ASCUdevice");
2221       break;
2222     case LangAS::cuda_constant:
2223       Extra.mangleSourceName("_ASCUconstant");
2224       break;
2225     case LangAS::cuda_shared:
2226       Extra.mangleSourceName("_ASCUshared");
2227       break;
2228     case LangAS::ptr32_sptr:
2229     case LangAS::ptr32_uptr:
2230     case LangAS::ptr64:
2231       llvm_unreachable("don't mangle ptr address spaces with _AS");
2232     }
2233   }
2234 
2235   Extra.mangleType(T, Range, QMM_Escape);
2236   mangleQualifiers(Qualifiers(), false);
2237   mangleArtificialTagType(TTK_Struct, ASMangling, {"__clang"});
2238 }
2239 
2240 void MicrosoftCXXNameMangler::mangleType(QualType T, SourceRange Range,
2241                                          QualifierMangleMode QMM) {
2242   // Don't use the canonical types.  MSVC includes things like 'const' on
2243   // pointer arguments to function pointers that canonicalization strips away.
2244   T = T.getDesugaredType(getASTContext());
2245   Qualifiers Quals = T.getLocalQualifiers();
2246 
2247   if (const ArrayType *AT = getASTContext().getAsArrayType(T)) {
2248     // If there were any Quals, getAsArrayType() pushed them onto the array
2249     // element type.
2250     if (QMM == QMM_Mangle)
2251       Out << 'A';
2252     else if (QMM == QMM_Escape || QMM == QMM_Result)
2253       Out << "$$B";
2254     mangleArrayType(AT);
2255     return;
2256   }
2257 
2258   bool IsPointer = T->isAnyPointerType() || T->isMemberPointerType() ||
2259                    T->isReferenceType() || T->isBlockPointerType();
2260 
2261   switch (QMM) {
2262   case QMM_Drop:
2263     if (Quals.hasObjCLifetime())
2264       Quals = Quals.withoutObjCLifetime();
2265     break;
2266   case QMM_Mangle:
2267     if (const FunctionType *FT = dyn_cast<FunctionType>(T)) {
2268       Out << '6';
2269       mangleFunctionType(FT);
2270       return;
2271     }
2272     mangleQualifiers(Quals, false);
2273     break;
2274   case QMM_Escape:
2275     if (!IsPointer && Quals) {
2276       Out << "$$C";
2277       mangleQualifiers(Quals, false);
2278     }
2279     break;
2280   case QMM_Result:
2281     // Presence of __unaligned qualifier shouldn't affect mangling here.
2282     Quals.removeUnaligned();
2283     if (Quals.hasObjCLifetime())
2284       Quals = Quals.withoutObjCLifetime();
2285     if ((!IsPointer && Quals) || isa<TagType>(T) || isArtificialTagType(T)) {
2286       Out << '?';
2287       mangleQualifiers(Quals, false);
2288     }
2289     break;
2290   }
2291 
2292   const Type *ty = T.getTypePtr();
2293 
2294   switch (ty->getTypeClass()) {
2295 #define ABSTRACT_TYPE(CLASS, PARENT)
2296 #define NON_CANONICAL_TYPE(CLASS, PARENT) \
2297   case Type::CLASS: \
2298     llvm_unreachable("can't mangle non-canonical type " #CLASS "Type"); \
2299     return;
2300 #define TYPE(CLASS, PARENT) \
2301   case Type::CLASS: \
2302     mangleType(cast<CLASS##Type>(ty), Quals, Range); \
2303     break;
2304 #include "clang/AST/TypeNodes.inc"
2305 #undef ABSTRACT_TYPE
2306 #undef NON_CANONICAL_TYPE
2307 #undef TYPE
2308   }
2309 }
2310 
2311 void MicrosoftCXXNameMangler::mangleType(const BuiltinType *T, Qualifiers,
2312                                          SourceRange Range) {
2313   //  <type>         ::= <builtin-type>
2314   //  <builtin-type> ::= X  # void
2315   //                 ::= C  # signed char
2316   //                 ::= D  # char
2317   //                 ::= E  # unsigned char
2318   //                 ::= F  # short
2319   //                 ::= G  # unsigned short (or wchar_t if it's not a builtin)
2320   //                 ::= H  # int
2321   //                 ::= I  # unsigned int
2322   //                 ::= J  # long
2323   //                 ::= K  # unsigned long
2324   //                     L  # <none>
2325   //                 ::= M  # float
2326   //                 ::= N  # double
2327   //                 ::= O  # long double (__float80 is mangled differently)
2328   //                 ::= _J # long long, __int64
2329   //                 ::= _K # unsigned long long, __int64
2330   //                 ::= _L # __int128
2331   //                 ::= _M # unsigned __int128
2332   //                 ::= _N # bool
2333   //                     _O # <array in parameter>
2334   //                 ::= _Q # char8_t
2335   //                 ::= _S # char16_t
2336   //                 ::= _T # __float80 (Intel)
2337   //                 ::= _U # char32_t
2338   //                 ::= _W # wchar_t
2339   //                 ::= _Z # __float80 (Digital Mars)
2340   switch (T->getKind()) {
2341   case BuiltinType::Void:
2342     Out << 'X';
2343     break;
2344   case BuiltinType::SChar:
2345     Out << 'C';
2346     break;
2347   case BuiltinType::Char_U:
2348   case BuiltinType::Char_S:
2349     Out << 'D';
2350     break;
2351   case BuiltinType::UChar:
2352     Out << 'E';
2353     break;
2354   case BuiltinType::Short:
2355     Out << 'F';
2356     break;
2357   case BuiltinType::UShort:
2358     Out << 'G';
2359     break;
2360   case BuiltinType::Int:
2361     Out << 'H';
2362     break;
2363   case BuiltinType::UInt:
2364     Out << 'I';
2365     break;
2366   case BuiltinType::Long:
2367     Out << 'J';
2368     break;
2369   case BuiltinType::ULong:
2370     Out << 'K';
2371     break;
2372   case BuiltinType::Float:
2373     Out << 'M';
2374     break;
2375   case BuiltinType::Double:
2376     Out << 'N';
2377     break;
2378   // TODO: Determine size and mangle accordingly
2379   case BuiltinType::LongDouble:
2380     Out << 'O';
2381     break;
2382   case BuiltinType::LongLong:
2383     Out << "_J";
2384     break;
2385   case BuiltinType::ULongLong:
2386     Out << "_K";
2387     break;
2388   case BuiltinType::Int128:
2389     Out << "_L";
2390     break;
2391   case BuiltinType::UInt128:
2392     Out << "_M";
2393     break;
2394   case BuiltinType::Bool:
2395     Out << "_N";
2396     break;
2397   case BuiltinType::Char8:
2398     Out << "_Q";
2399     break;
2400   case BuiltinType::Char16:
2401     Out << "_S";
2402     break;
2403   case BuiltinType::Char32:
2404     Out << "_U";
2405     break;
2406   case BuiltinType::WChar_S:
2407   case BuiltinType::WChar_U:
2408     Out << "_W";
2409     break;
2410 
2411 #define BUILTIN_TYPE(Id, SingletonId)
2412 #define PLACEHOLDER_TYPE(Id, SingletonId) \
2413   case BuiltinType::Id:
2414 #include "clang/AST/BuiltinTypes.def"
2415   case BuiltinType::Dependent:
2416     llvm_unreachable("placeholder types shouldn't get to name mangling");
2417 
2418   case BuiltinType::ObjCId:
2419     mangleArtificialTagType(TTK_Struct, "objc_object");
2420     break;
2421   case BuiltinType::ObjCClass:
2422     mangleArtificialTagType(TTK_Struct, "objc_class");
2423     break;
2424   case BuiltinType::ObjCSel:
2425     mangleArtificialTagType(TTK_Struct, "objc_selector");
2426     break;
2427 
2428 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
2429   case BuiltinType::Id: \
2430     Out << "PAUocl_" #ImgType "_" #Suffix "@@"; \
2431     break;
2432 #include "clang/Basic/OpenCLImageTypes.def"
2433   case BuiltinType::OCLSampler:
2434     Out << "PA";
2435     mangleArtificialTagType(TTK_Struct, "ocl_sampler");
2436     break;
2437   case BuiltinType::OCLEvent:
2438     Out << "PA";
2439     mangleArtificialTagType(TTK_Struct, "ocl_event");
2440     break;
2441   case BuiltinType::OCLClkEvent:
2442     Out << "PA";
2443     mangleArtificialTagType(TTK_Struct, "ocl_clkevent");
2444     break;
2445   case BuiltinType::OCLQueue:
2446     Out << "PA";
2447     mangleArtificialTagType(TTK_Struct, "ocl_queue");
2448     break;
2449   case BuiltinType::OCLReserveID:
2450     Out << "PA";
2451     mangleArtificialTagType(TTK_Struct, "ocl_reserveid");
2452     break;
2453 #define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
2454   case BuiltinType::Id: \
2455     mangleArtificialTagType(TTK_Struct, "ocl_" #ExtType); \
2456     break;
2457 #include "clang/Basic/OpenCLExtensionTypes.def"
2458 
2459   case BuiltinType::NullPtr:
2460     Out << "$$T";
2461     break;
2462 
2463   case BuiltinType::Float16:
2464     mangleArtificialTagType(TTK_Struct, "_Float16", {"__clang"});
2465     break;
2466 
2467   case BuiltinType::Half:
2468     if (!getASTContext().getLangOpts().HLSL)
2469       mangleArtificialTagType(TTK_Struct, "_Half", {"__clang"});
2470     else if (getASTContext().getLangOpts().NativeHalfType)
2471       Out << "$f16@";
2472     else
2473       Out << "$halff@";
2474     break;
2475 
2476   case BuiltinType::BFloat16:
2477     mangleArtificialTagType(TTK_Struct, "__bf16", {"__clang"});
2478     break;
2479 
2480 #define SVE_TYPE(Name, Id, SingletonId) \
2481   case BuiltinType::Id:
2482 #include "clang/Basic/AArch64SVEACLETypes.def"
2483 #define PPC_VECTOR_TYPE(Name, Id, Size) \
2484   case BuiltinType::Id:
2485 #include "clang/Basic/PPCTypes.def"
2486 #define RVV_TYPE(Name, Id, SingletonId) case BuiltinType::Id:
2487 #include "clang/Basic/RISCVVTypes.def"
2488   case BuiltinType::ShortAccum:
2489   case BuiltinType::Accum:
2490   case BuiltinType::LongAccum:
2491   case BuiltinType::UShortAccum:
2492   case BuiltinType::UAccum:
2493   case BuiltinType::ULongAccum:
2494   case BuiltinType::ShortFract:
2495   case BuiltinType::Fract:
2496   case BuiltinType::LongFract:
2497   case BuiltinType::UShortFract:
2498   case BuiltinType::UFract:
2499   case BuiltinType::ULongFract:
2500   case BuiltinType::SatShortAccum:
2501   case BuiltinType::SatAccum:
2502   case BuiltinType::SatLongAccum:
2503   case BuiltinType::SatUShortAccum:
2504   case BuiltinType::SatUAccum:
2505   case BuiltinType::SatULongAccum:
2506   case BuiltinType::SatShortFract:
2507   case BuiltinType::SatFract:
2508   case BuiltinType::SatLongFract:
2509   case BuiltinType::SatUShortFract:
2510   case BuiltinType::SatUFract:
2511   case BuiltinType::SatULongFract:
2512   case BuiltinType::Ibm128:
2513   case BuiltinType::Float128: {
2514     DiagnosticsEngine &Diags = Context.getDiags();
2515     unsigned DiagID = Diags.getCustomDiagID(
2516         DiagnosticsEngine::Error, "cannot mangle this built-in %0 type yet");
2517     Diags.Report(Range.getBegin(), DiagID)
2518         << T->getName(Context.getASTContext().getPrintingPolicy()) << Range;
2519     break;
2520   }
2521   }
2522 }
2523 
2524 // <type>          ::= <function-type>
2525 void MicrosoftCXXNameMangler::mangleType(const FunctionProtoType *T, Qualifiers,
2526                                          SourceRange) {
2527   // Structors only appear in decls, so at this point we know it's not a
2528   // structor type.
2529   // FIXME: This may not be lambda-friendly.
2530   if (T->getMethodQuals() || T->getRefQualifier() != RQ_None) {
2531     Out << "$$A8@@";
2532     mangleFunctionType(T, /*D=*/nullptr, /*ForceThisQuals=*/true);
2533   } else {
2534     Out << "$$A6";
2535     mangleFunctionType(T);
2536   }
2537 }
2538 void MicrosoftCXXNameMangler::mangleType(const FunctionNoProtoType *T,
2539                                          Qualifiers, SourceRange) {
2540   Out << "$$A6";
2541   mangleFunctionType(T);
2542 }
2543 
2544 void MicrosoftCXXNameMangler::mangleFunctionType(const FunctionType *T,
2545                                                  const FunctionDecl *D,
2546                                                  bool ForceThisQuals,
2547                                                  bool MangleExceptionSpec) {
2548   // <function-type> ::= <this-cvr-qualifiers> <calling-convention>
2549   //                     <return-type> <argument-list> <throw-spec>
2550   const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(T);
2551 
2552   SourceRange Range;
2553   if (D) Range = D->getSourceRange();
2554 
2555   bool IsInLambda = false;
2556   bool IsStructor = false, HasThisQuals = ForceThisQuals, IsCtorClosure = false;
2557   CallingConv CC = T->getCallConv();
2558   if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(D)) {
2559     if (MD->getParent()->isLambda())
2560       IsInLambda = true;
2561     if (MD->isInstance())
2562       HasThisQuals = true;
2563     if (isa<CXXDestructorDecl>(MD)) {
2564       IsStructor = true;
2565     } else if (isa<CXXConstructorDecl>(MD)) {
2566       IsStructor = true;
2567       IsCtorClosure = (StructorType == Ctor_CopyingClosure ||
2568                        StructorType == Ctor_DefaultClosure) &&
2569                       isStructorDecl(MD);
2570       if (IsCtorClosure)
2571         CC = getASTContext().getDefaultCallingConvention(
2572             /*IsVariadic=*/false, /*IsCXXMethod=*/true);
2573     }
2574   }
2575 
2576   // If this is a C++ instance method, mangle the CVR qualifiers for the
2577   // this pointer.
2578   if (HasThisQuals) {
2579     Qualifiers Quals = Proto->getMethodQuals();
2580     manglePointerExtQualifiers(Quals, /*PointeeType=*/QualType());
2581     mangleRefQualifier(Proto->getRefQualifier());
2582     mangleQualifiers(Quals, /*IsMember=*/false);
2583   }
2584 
2585   mangleCallingConvention(CC);
2586 
2587   // <return-type> ::= <type>
2588   //               ::= @ # structors (they have no declared return type)
2589   if (IsStructor) {
2590     if (isa<CXXDestructorDecl>(D) && isStructorDecl(D)) {
2591       // The scalar deleting destructor takes an extra int argument which is not
2592       // reflected in the AST.
2593       if (StructorType == Dtor_Deleting) {
2594         Out << (PointersAre64Bit ? "PEAXI@Z" : "PAXI@Z");
2595         return;
2596       }
2597       // The vbase destructor returns void which is not reflected in the AST.
2598       if (StructorType == Dtor_Complete) {
2599         Out << "XXZ";
2600         return;
2601       }
2602     }
2603     if (IsCtorClosure) {
2604       // Default constructor closure and copy constructor closure both return
2605       // void.
2606       Out << 'X';
2607 
2608       if (StructorType == Ctor_DefaultClosure) {
2609         // Default constructor closure always has no arguments.
2610         Out << 'X';
2611       } else if (StructorType == Ctor_CopyingClosure) {
2612         // Copy constructor closure always takes an unqualified reference.
2613         mangleFunctionArgumentType(getASTContext().getLValueReferenceType(
2614                                        Proto->getParamType(0)
2615                                            ->getAs<LValueReferenceType>()
2616                                            ->getPointeeType(),
2617                                        /*SpelledAsLValue=*/true),
2618                                    Range);
2619         Out << '@';
2620       } else {
2621         llvm_unreachable("unexpected constructor closure!");
2622       }
2623       Out << 'Z';
2624       return;
2625     }
2626     Out << '@';
2627   } else if (IsInLambda && D && isa<CXXConversionDecl>(D)) {
2628     // The only lambda conversion operators are to function pointers, which
2629     // can differ by their calling convention and are typically deduced.  So
2630     // we make sure that this type gets mangled properly.
2631     mangleType(T->getReturnType(), Range, QMM_Result);
2632   } else {
2633     QualType ResultType = T->getReturnType();
2634     if (IsInLambda && isa<CXXConversionDecl>(D)) {
2635       // The only lambda conversion operators are to function pointers, which
2636       // can differ by their calling convention and are typically deduced.  So
2637       // we make sure that this type gets mangled properly.
2638       mangleType(ResultType, Range, QMM_Result);
2639     } else if (const auto *AT = dyn_cast_or_null<AutoType>(
2640                    ResultType->getContainedAutoType())) {
2641       Out << '?';
2642       mangleQualifiers(ResultType.getLocalQualifiers(), /*IsMember=*/false);
2643       Out << '?';
2644       assert(AT->getKeyword() != AutoTypeKeyword::GNUAutoType &&
2645              "shouldn't need to mangle __auto_type!");
2646       mangleSourceName(AT->isDecltypeAuto() ? "<decltype-auto>" : "<auto>");
2647       Out << '@';
2648     } else if (IsInLambda) {
2649       Out << '@';
2650     } else {
2651       if (ResultType->isVoidType())
2652         ResultType = ResultType.getUnqualifiedType();
2653       mangleType(ResultType, Range, QMM_Result);
2654     }
2655   }
2656 
2657   // <argument-list> ::= X # void
2658   //                 ::= <type>+ @
2659   //                 ::= <type>* Z # varargs
2660   if (!Proto) {
2661     // Function types without prototypes can arise when mangling a function type
2662     // within an overloadable function in C. We mangle these as the absence of
2663     // any parameter types (not even an empty parameter list).
2664     Out << '@';
2665   } else if (Proto->getNumParams() == 0 && !Proto->isVariadic()) {
2666     Out << 'X';
2667   } else {
2668     // Happens for function pointer type arguments for example.
2669     for (unsigned I = 0, E = Proto->getNumParams(); I != E; ++I) {
2670       mangleFunctionArgumentType(Proto->getParamType(I), Range);
2671       // Mangle each pass_object_size parameter as if it's a parameter of enum
2672       // type passed directly after the parameter with the pass_object_size
2673       // attribute. The aforementioned enum's name is __pass_object_size, and we
2674       // pretend it resides in a top-level namespace called __clang.
2675       //
2676       // FIXME: Is there a defined extension notation for the MS ABI, or is it
2677       // necessary to just cross our fingers and hope this type+namespace
2678       // combination doesn't conflict with anything?
2679       if (D)
2680         if (const auto *P = D->getParamDecl(I)->getAttr<PassObjectSizeAttr>())
2681           manglePassObjectSizeArg(P);
2682     }
2683     // <builtin-type>      ::= Z  # ellipsis
2684     if (Proto->isVariadic())
2685       Out << 'Z';
2686     else
2687       Out << '@';
2688   }
2689 
2690   if (MangleExceptionSpec && getASTContext().getLangOpts().CPlusPlus17 &&
2691       getASTContext().getLangOpts().isCompatibleWithMSVC(
2692           LangOptions::MSVC2017_5))
2693     mangleThrowSpecification(Proto);
2694   else
2695     Out << 'Z';
2696 }
2697 
2698 void MicrosoftCXXNameMangler::mangleFunctionClass(const FunctionDecl *FD) {
2699   // <function-class>  ::= <member-function> E? # E designates a 64-bit 'this'
2700   //                                            # pointer. in 64-bit mode *all*
2701   //                                            # 'this' pointers are 64-bit.
2702   //                   ::= <global-function>
2703   // <member-function> ::= A # private: near
2704   //                   ::= B # private: far
2705   //                   ::= C # private: static near
2706   //                   ::= D # private: static far
2707   //                   ::= E # private: virtual near
2708   //                   ::= F # private: virtual far
2709   //                   ::= I # protected: near
2710   //                   ::= J # protected: far
2711   //                   ::= K # protected: static near
2712   //                   ::= L # protected: static far
2713   //                   ::= M # protected: virtual near
2714   //                   ::= N # protected: virtual far
2715   //                   ::= Q # public: near
2716   //                   ::= R # public: far
2717   //                   ::= S # public: static near
2718   //                   ::= T # public: static far
2719   //                   ::= U # public: virtual near
2720   //                   ::= V # public: virtual far
2721   // <global-function> ::= Y # global near
2722   //                   ::= Z # global far
2723   if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
2724     bool IsVirtual = MD->isVirtual();
2725     // When mangling vbase destructor variants, ignore whether or not the
2726     // underlying destructor was defined to be virtual.
2727     if (isa<CXXDestructorDecl>(MD) && isStructorDecl(MD) &&
2728         StructorType == Dtor_Complete) {
2729       IsVirtual = false;
2730     }
2731     switch (MD->getAccess()) {
2732       case AS_none:
2733         llvm_unreachable("Unsupported access specifier");
2734       case AS_private:
2735         if (MD->isStatic())
2736           Out << 'C';
2737         else if (IsVirtual)
2738           Out << 'E';
2739         else
2740           Out << 'A';
2741         break;
2742       case AS_protected:
2743         if (MD->isStatic())
2744           Out << 'K';
2745         else if (IsVirtual)
2746           Out << 'M';
2747         else
2748           Out << 'I';
2749         break;
2750       case AS_public:
2751         if (MD->isStatic())
2752           Out << 'S';
2753         else if (IsVirtual)
2754           Out << 'U';
2755         else
2756           Out << 'Q';
2757     }
2758   } else {
2759     Out << 'Y';
2760   }
2761 }
2762 void MicrosoftCXXNameMangler::mangleCallingConvention(CallingConv CC) {
2763   // <calling-convention> ::= A # __cdecl
2764   //                      ::= B # __export __cdecl
2765   //                      ::= C # __pascal
2766   //                      ::= D # __export __pascal
2767   //                      ::= E # __thiscall
2768   //                      ::= F # __export __thiscall
2769   //                      ::= G # __stdcall
2770   //                      ::= H # __export __stdcall
2771   //                      ::= I # __fastcall
2772   //                      ::= J # __export __fastcall
2773   //                      ::= Q # __vectorcall
2774   //                      ::= S # __attribute__((__swiftcall__)) // Clang-only
2775   //                      ::= T # __attribute__((__swiftasynccall__))
2776   //                            // Clang-only
2777   //                      ::= w # __regcall
2778   // The 'export' calling conventions are from a bygone era
2779   // (*cough*Win16*cough*) when functions were declared for export with
2780   // that keyword. (It didn't actually export them, it just made them so
2781   // that they could be in a DLL and somebody from another module could call
2782   // them.)
2783 
2784   switch (CC) {
2785     default:
2786       llvm_unreachable("Unsupported CC for mangling");
2787     case CC_Win64:
2788     case CC_X86_64SysV:
2789     case CC_C: Out << 'A'; break;
2790     case CC_X86Pascal: Out << 'C'; break;
2791     case CC_X86ThisCall: Out << 'E'; break;
2792     case CC_X86StdCall: Out << 'G'; break;
2793     case CC_X86FastCall: Out << 'I'; break;
2794     case CC_X86VectorCall: Out << 'Q'; break;
2795     case CC_Swift: Out << 'S'; break;
2796     case CC_SwiftAsync: Out << 'W'; break;
2797     case CC_PreserveMost: Out << 'U'; break;
2798     case CC_X86RegCall: Out << 'w'; break;
2799   }
2800 }
2801 void MicrosoftCXXNameMangler::mangleCallingConvention(const FunctionType *T) {
2802   mangleCallingConvention(T->getCallConv());
2803 }
2804 
2805 void MicrosoftCXXNameMangler::mangleThrowSpecification(
2806                                                 const FunctionProtoType *FT) {
2807   // <throw-spec> ::= Z # (default)
2808   //              ::= _E # noexcept
2809   if (FT->canThrow())
2810     Out << 'Z';
2811   else
2812     Out << "_E";
2813 }
2814 
2815 void MicrosoftCXXNameMangler::mangleType(const UnresolvedUsingType *T,
2816                                          Qualifiers, SourceRange Range) {
2817   // Probably should be mangled as a template instantiation; need to see what
2818   // VC does first.
2819   DiagnosticsEngine &Diags = Context.getDiags();
2820   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2821     "cannot mangle this unresolved dependent type yet");
2822   Diags.Report(Range.getBegin(), DiagID)
2823     << Range;
2824 }
2825 
2826 // <type>        ::= <union-type> | <struct-type> | <class-type> | <enum-type>
2827 // <union-type>  ::= T <name>
2828 // <struct-type> ::= U <name>
2829 // <class-type>  ::= V <name>
2830 // <enum-type>   ::= W4 <name>
2831 void MicrosoftCXXNameMangler::mangleTagTypeKind(TagTypeKind TTK) {
2832   switch (TTK) {
2833     case TTK_Union:
2834       Out << 'T';
2835       break;
2836     case TTK_Struct:
2837     case TTK_Interface:
2838       Out << 'U';
2839       break;
2840     case TTK_Class:
2841       Out << 'V';
2842       break;
2843     case TTK_Enum:
2844       Out << "W4";
2845       break;
2846   }
2847 }
2848 void MicrosoftCXXNameMangler::mangleType(const EnumType *T, Qualifiers,
2849                                          SourceRange) {
2850   mangleType(cast<TagType>(T)->getDecl());
2851 }
2852 void MicrosoftCXXNameMangler::mangleType(const RecordType *T, Qualifiers,
2853                                          SourceRange) {
2854   mangleType(cast<TagType>(T)->getDecl());
2855 }
2856 void MicrosoftCXXNameMangler::mangleType(const TagDecl *TD) {
2857   mangleTagTypeKind(TD->getTagKind());
2858   mangleName(TD);
2859 }
2860 
2861 // If you add a call to this, consider updating isArtificialTagType() too.
2862 void MicrosoftCXXNameMangler::mangleArtificialTagType(
2863     TagTypeKind TK, StringRef UnqualifiedName,
2864     ArrayRef<StringRef> NestedNames) {
2865   // <name> ::= <unscoped-name> {[<named-scope>]+ | [<nested-name>]}? @
2866   mangleTagTypeKind(TK);
2867 
2868   // Always start with the unqualified name.
2869   mangleSourceName(UnqualifiedName);
2870 
2871   for (StringRef N : llvm::reverse(NestedNames))
2872     mangleSourceName(N);
2873 
2874   // Terminate the whole name with an '@'.
2875   Out << '@';
2876 }
2877 
2878 // <type>       ::= <array-type>
2879 // <array-type> ::= <pointer-cvr-qualifiers> <cvr-qualifiers>
2880 //                  [Y <dimension-count> <dimension>+]
2881 //                  <element-type> # as global, E is never required
2882 // It's supposed to be the other way around, but for some strange reason, it
2883 // isn't. Today this behavior is retained for the sole purpose of backwards
2884 // compatibility.
2885 void MicrosoftCXXNameMangler::mangleDecayedArrayType(const ArrayType *T) {
2886   // This isn't a recursive mangling, so now we have to do it all in this
2887   // one call.
2888   manglePointerCVQualifiers(T->getElementType().getQualifiers());
2889   mangleType(T->getElementType(), SourceRange());
2890 }
2891 void MicrosoftCXXNameMangler::mangleType(const ConstantArrayType *T, Qualifiers,
2892                                          SourceRange) {
2893   llvm_unreachable("Should have been special cased");
2894 }
2895 void MicrosoftCXXNameMangler::mangleType(const VariableArrayType *T, Qualifiers,
2896                                          SourceRange) {
2897   llvm_unreachable("Should have been special cased");
2898 }
2899 void MicrosoftCXXNameMangler::mangleType(const DependentSizedArrayType *T,
2900                                          Qualifiers, SourceRange) {
2901   llvm_unreachable("Should have been special cased");
2902 }
2903 void MicrosoftCXXNameMangler::mangleType(const IncompleteArrayType *T,
2904                                          Qualifiers, SourceRange) {
2905   llvm_unreachable("Should have been special cased");
2906 }
2907 void MicrosoftCXXNameMangler::mangleArrayType(const ArrayType *T) {
2908   QualType ElementTy(T, 0);
2909   SmallVector<llvm::APInt, 3> Dimensions;
2910   for (;;) {
2911     if (ElementTy->isConstantArrayType()) {
2912       const ConstantArrayType *CAT =
2913           getASTContext().getAsConstantArrayType(ElementTy);
2914       Dimensions.push_back(CAT->getSize());
2915       ElementTy = CAT->getElementType();
2916     } else if (ElementTy->isIncompleteArrayType()) {
2917       const IncompleteArrayType *IAT =
2918           getASTContext().getAsIncompleteArrayType(ElementTy);
2919       Dimensions.push_back(llvm::APInt(32, 0));
2920       ElementTy = IAT->getElementType();
2921     } else if (ElementTy->isVariableArrayType()) {
2922       const VariableArrayType *VAT =
2923         getASTContext().getAsVariableArrayType(ElementTy);
2924       Dimensions.push_back(llvm::APInt(32, 0));
2925       ElementTy = VAT->getElementType();
2926     } else if (ElementTy->isDependentSizedArrayType()) {
2927       // The dependent expression has to be folded into a constant (TODO).
2928       const DependentSizedArrayType *DSAT =
2929         getASTContext().getAsDependentSizedArrayType(ElementTy);
2930       DiagnosticsEngine &Diags = Context.getDiags();
2931       unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2932         "cannot mangle this dependent-length array yet");
2933       Diags.Report(DSAT->getSizeExpr()->getExprLoc(), DiagID)
2934         << DSAT->getBracketsRange();
2935       return;
2936     } else {
2937       break;
2938     }
2939   }
2940   Out << 'Y';
2941   // <dimension-count> ::= <number> # number of extra dimensions
2942   mangleNumber(Dimensions.size());
2943   for (const llvm::APInt &Dimension : Dimensions)
2944     mangleNumber(Dimension.getLimitedValue());
2945   mangleType(ElementTy, SourceRange(), QMM_Escape);
2946 }
2947 
2948 // <type>                   ::= <pointer-to-member-type>
2949 // <pointer-to-member-type> ::= <pointer-cvr-qualifiers> <cvr-qualifiers>
2950 //                                                          <class name> <type>
2951 void MicrosoftCXXNameMangler::mangleType(const MemberPointerType *T,
2952                                          Qualifiers Quals, SourceRange Range) {
2953   QualType PointeeType = T->getPointeeType();
2954   manglePointerCVQualifiers(Quals);
2955   manglePointerExtQualifiers(Quals, PointeeType);
2956   if (const FunctionProtoType *FPT = PointeeType->getAs<FunctionProtoType>()) {
2957     Out << '8';
2958     mangleName(T->getClass()->castAs<RecordType>()->getDecl());
2959     mangleFunctionType(FPT, nullptr, true);
2960   } else {
2961     mangleQualifiers(PointeeType.getQualifiers(), true);
2962     mangleName(T->getClass()->castAs<RecordType>()->getDecl());
2963     mangleType(PointeeType, Range, QMM_Drop);
2964   }
2965 }
2966 
2967 void MicrosoftCXXNameMangler::mangleType(const TemplateTypeParmType *T,
2968                                          Qualifiers, SourceRange Range) {
2969   DiagnosticsEngine &Diags = Context.getDiags();
2970   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2971     "cannot mangle this template type parameter type yet");
2972   Diags.Report(Range.getBegin(), DiagID)
2973     << Range;
2974 }
2975 
2976 void MicrosoftCXXNameMangler::mangleType(const SubstTemplateTypeParmPackType *T,
2977                                          Qualifiers, SourceRange Range) {
2978   DiagnosticsEngine &Diags = Context.getDiags();
2979   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2980     "cannot mangle this substituted parameter pack yet");
2981   Diags.Report(Range.getBegin(), DiagID)
2982     << Range;
2983 }
2984 
2985 // <type> ::= <pointer-type>
2986 // <pointer-type> ::= E? <pointer-cvr-qualifiers> <cvr-qualifiers> <type>
2987 //                       # the E is required for 64-bit non-static pointers
2988 void MicrosoftCXXNameMangler::mangleType(const PointerType *T, Qualifiers Quals,
2989                                          SourceRange Range) {
2990   QualType PointeeType = T->getPointeeType();
2991   manglePointerCVQualifiers(Quals);
2992   manglePointerExtQualifiers(Quals, PointeeType);
2993 
2994   // For pointer size address spaces, go down the same type mangling path as
2995   // non address space types.
2996   LangAS AddrSpace = PointeeType.getQualifiers().getAddressSpace();
2997   if (isPtrSizeAddressSpace(AddrSpace) || AddrSpace == LangAS::Default)
2998     mangleType(PointeeType, Range);
2999   else
3000     mangleAddressSpaceType(PointeeType, PointeeType.getQualifiers(), Range);
3001 }
3002 
3003 void MicrosoftCXXNameMangler::mangleType(const ObjCObjectPointerType *T,
3004                                          Qualifiers Quals, SourceRange Range) {
3005   QualType PointeeType = T->getPointeeType();
3006   switch (Quals.getObjCLifetime()) {
3007   case Qualifiers::OCL_None:
3008   case Qualifiers::OCL_ExplicitNone:
3009     break;
3010   case Qualifiers::OCL_Autoreleasing:
3011   case Qualifiers::OCL_Strong:
3012   case Qualifiers::OCL_Weak:
3013     return mangleObjCLifetime(PointeeType, Quals, Range);
3014   }
3015   manglePointerCVQualifiers(Quals);
3016   manglePointerExtQualifiers(Quals, PointeeType);
3017   mangleType(PointeeType, Range);
3018 }
3019 
3020 // <type> ::= <reference-type>
3021 // <reference-type> ::= A E? <cvr-qualifiers> <type>
3022 //                 # the E is required for 64-bit non-static lvalue references
3023 void MicrosoftCXXNameMangler::mangleType(const LValueReferenceType *T,
3024                                          Qualifiers Quals, SourceRange Range) {
3025   QualType PointeeType = T->getPointeeType();
3026   assert(!Quals.hasConst() && !Quals.hasVolatile() && "unexpected qualifier!");
3027   Out << 'A';
3028   manglePointerExtQualifiers(Quals, PointeeType);
3029   mangleType(PointeeType, Range);
3030 }
3031 
3032 // <type> ::= <r-value-reference-type>
3033 // <r-value-reference-type> ::= $$Q E? <cvr-qualifiers> <type>
3034 //                 # the E is required for 64-bit non-static rvalue references
3035 void MicrosoftCXXNameMangler::mangleType(const RValueReferenceType *T,
3036                                          Qualifiers Quals, SourceRange Range) {
3037   QualType PointeeType = T->getPointeeType();
3038   assert(!Quals.hasConst() && !Quals.hasVolatile() && "unexpected qualifier!");
3039   Out << "$$Q";
3040   manglePointerExtQualifiers(Quals, PointeeType);
3041   mangleType(PointeeType, Range);
3042 }
3043 
3044 void MicrosoftCXXNameMangler::mangleType(const ComplexType *T, Qualifiers,
3045                                          SourceRange Range) {
3046   QualType ElementType = T->getElementType();
3047 
3048   llvm::SmallString<64> TemplateMangling;
3049   llvm::raw_svector_ostream Stream(TemplateMangling);
3050   MicrosoftCXXNameMangler Extra(Context, Stream);
3051   Stream << "?$";
3052   Extra.mangleSourceName("_Complex");
3053   Extra.mangleType(ElementType, Range, QMM_Escape);
3054 
3055   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__clang"});
3056 }
3057 
3058 // Returns true for types that mangleArtificialTagType() gets called for with
3059 // TTK_Union, TTK_Struct, TTK_Class and where compatibility with MSVC's
3060 // mangling matters.
3061 // (It doesn't matter for Objective-C types and the like that cl.exe doesn't
3062 // support.)
3063 bool MicrosoftCXXNameMangler::isArtificialTagType(QualType T) const {
3064   const Type *ty = T.getTypePtr();
3065   switch (ty->getTypeClass()) {
3066   default:
3067     return false;
3068 
3069   case Type::Vector: {
3070     // For ABI compatibility only __m64, __m128(id), and __m256(id) matter,
3071     // but since mangleType(VectorType*) always calls mangleArtificialTagType()
3072     // just always return true (the other vector types are clang-only).
3073     return true;
3074   }
3075   }
3076 }
3077 
3078 void MicrosoftCXXNameMangler::mangleType(const VectorType *T, Qualifiers Quals,
3079                                          SourceRange Range) {
3080   QualType EltTy = T->getElementType();
3081   const BuiltinType *ET = EltTy->getAs<BuiltinType>();
3082   const BitIntType *BitIntTy = EltTy->getAs<BitIntType>();
3083   assert((ET || BitIntTy) &&
3084          "vectors with non-builtin/_BitInt elements are unsupported");
3085   uint64_t Width = getASTContext().getTypeSize(T);
3086   // Pattern match exactly the typedefs in our intrinsic headers.  Anything that
3087   // doesn't match the Intel types uses a custom mangling below.
3088   size_t OutSizeBefore = Out.tell();
3089   if (!isa<ExtVectorType>(T)) {
3090     if (getASTContext().getTargetInfo().getTriple().isX86() && ET) {
3091       if (Width == 64 && ET->getKind() == BuiltinType::LongLong) {
3092         mangleArtificialTagType(TTK_Union, "__m64");
3093       } else if (Width >= 128) {
3094         if (ET->getKind() == BuiltinType::Float)
3095           mangleArtificialTagType(TTK_Union, "__m" + llvm::utostr(Width));
3096         else if (ET->getKind() == BuiltinType::LongLong)
3097           mangleArtificialTagType(TTK_Union, "__m" + llvm::utostr(Width) + 'i');
3098         else if (ET->getKind() == BuiltinType::Double)
3099           mangleArtificialTagType(TTK_Struct, "__m" + llvm::utostr(Width) + 'd');
3100       }
3101     }
3102   }
3103 
3104   bool IsBuiltin = Out.tell() != OutSizeBefore;
3105   if (!IsBuiltin) {
3106     // The MS ABI doesn't have a special mangling for vector types, so we define
3107     // our own mangling to handle uses of __vector_size__ on user-specified
3108     // types, and for extensions like __v4sf.
3109 
3110     llvm::SmallString<64> TemplateMangling;
3111     llvm::raw_svector_ostream Stream(TemplateMangling);
3112     MicrosoftCXXNameMangler Extra(Context, Stream);
3113     Stream << "?$";
3114     Extra.mangleSourceName("__vector");
3115     Extra.mangleType(QualType(ET ? static_cast<const Type *>(ET) : BitIntTy, 0),
3116                      Range, QMM_Escape);
3117     Extra.mangleIntegerLiteral(llvm::APSInt::getUnsigned(T->getNumElements()));
3118 
3119     mangleArtificialTagType(TTK_Union, TemplateMangling, {"__clang"});
3120   }
3121 }
3122 
3123 void MicrosoftCXXNameMangler::mangleType(const ExtVectorType *T,
3124                                          Qualifiers Quals, SourceRange Range) {
3125   mangleType(static_cast<const VectorType *>(T), Quals, Range);
3126 }
3127 
3128 void MicrosoftCXXNameMangler::mangleType(const DependentVectorType *T,
3129                                          Qualifiers, SourceRange Range) {
3130   DiagnosticsEngine &Diags = Context.getDiags();
3131   unsigned DiagID = Diags.getCustomDiagID(
3132       DiagnosticsEngine::Error,
3133       "cannot mangle this dependent-sized vector type yet");
3134   Diags.Report(Range.getBegin(), DiagID) << Range;
3135 }
3136 
3137 void MicrosoftCXXNameMangler::mangleType(const DependentSizedExtVectorType *T,
3138                                          Qualifiers, SourceRange Range) {
3139   DiagnosticsEngine &Diags = Context.getDiags();
3140   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3141     "cannot mangle this dependent-sized extended vector type yet");
3142   Diags.Report(Range.getBegin(), DiagID)
3143     << Range;
3144 }
3145 
3146 void MicrosoftCXXNameMangler::mangleType(const ConstantMatrixType *T,
3147                                          Qualifiers quals, SourceRange Range) {
3148   DiagnosticsEngine &Diags = Context.getDiags();
3149   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3150                                           "Cannot mangle this matrix type yet");
3151   Diags.Report(Range.getBegin(), DiagID) << Range;
3152 }
3153 
3154 void MicrosoftCXXNameMangler::mangleType(const DependentSizedMatrixType *T,
3155                                          Qualifiers quals, SourceRange Range) {
3156   DiagnosticsEngine &Diags = Context.getDiags();
3157   unsigned DiagID = Diags.getCustomDiagID(
3158       DiagnosticsEngine::Error,
3159       "Cannot mangle this dependent-sized matrix type yet");
3160   Diags.Report(Range.getBegin(), DiagID) << Range;
3161 }
3162 
3163 void MicrosoftCXXNameMangler::mangleType(const DependentAddressSpaceType *T,
3164                                          Qualifiers, SourceRange Range) {
3165   DiagnosticsEngine &Diags = Context.getDiags();
3166   unsigned DiagID = Diags.getCustomDiagID(
3167       DiagnosticsEngine::Error,
3168       "cannot mangle this dependent address space type yet");
3169   Diags.Report(Range.getBegin(), DiagID) << Range;
3170 }
3171 
3172 void MicrosoftCXXNameMangler::mangleType(const ObjCInterfaceType *T, Qualifiers,
3173                                          SourceRange) {
3174   // ObjC interfaces have structs underlying them.
3175   mangleTagTypeKind(TTK_Struct);
3176   mangleName(T->getDecl());
3177 }
3178 
3179 void MicrosoftCXXNameMangler::mangleType(const ObjCObjectType *T,
3180                                          Qualifiers Quals, SourceRange Range) {
3181   if (T->isKindOfType())
3182     return mangleObjCKindOfType(T, Quals, Range);
3183 
3184   if (T->qual_empty() && !T->isSpecialized())
3185     return mangleType(T->getBaseType(), Range, QMM_Drop);
3186 
3187   ArgBackRefMap OuterFunArgsContext;
3188   ArgBackRefMap OuterTemplateArgsContext;
3189   BackRefVec OuterTemplateContext;
3190 
3191   FunArgBackReferences.swap(OuterFunArgsContext);
3192   TemplateArgBackReferences.swap(OuterTemplateArgsContext);
3193   NameBackReferences.swap(OuterTemplateContext);
3194 
3195   mangleTagTypeKind(TTK_Struct);
3196 
3197   Out << "?$";
3198   if (T->isObjCId())
3199     mangleSourceName("objc_object");
3200   else if (T->isObjCClass())
3201     mangleSourceName("objc_class");
3202   else
3203     mangleSourceName(T->getInterface()->getName());
3204 
3205   for (const auto &Q : T->quals())
3206     mangleObjCProtocol(Q);
3207 
3208   if (T->isSpecialized())
3209     for (const auto &TA : T->getTypeArgs())
3210       mangleType(TA, Range, QMM_Drop);
3211 
3212   Out << '@';
3213 
3214   Out << '@';
3215 
3216   FunArgBackReferences.swap(OuterFunArgsContext);
3217   TemplateArgBackReferences.swap(OuterTemplateArgsContext);
3218   NameBackReferences.swap(OuterTemplateContext);
3219 }
3220 
3221 void MicrosoftCXXNameMangler::mangleType(const BlockPointerType *T,
3222                                          Qualifiers Quals, SourceRange Range) {
3223   QualType PointeeType = T->getPointeeType();
3224   manglePointerCVQualifiers(Quals);
3225   manglePointerExtQualifiers(Quals, PointeeType);
3226 
3227   Out << "_E";
3228 
3229   mangleFunctionType(PointeeType->castAs<FunctionProtoType>());
3230 }
3231 
3232 void MicrosoftCXXNameMangler::mangleType(const InjectedClassNameType *,
3233                                          Qualifiers, SourceRange) {
3234   llvm_unreachable("Cannot mangle injected class name type.");
3235 }
3236 
3237 void MicrosoftCXXNameMangler::mangleType(const TemplateSpecializationType *T,
3238                                          Qualifiers, SourceRange Range) {
3239   DiagnosticsEngine &Diags = Context.getDiags();
3240   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3241     "cannot mangle this template specialization type yet");
3242   Diags.Report(Range.getBegin(), DiagID)
3243     << Range;
3244 }
3245 
3246 void MicrosoftCXXNameMangler::mangleType(const DependentNameType *T, Qualifiers,
3247                                          SourceRange Range) {
3248   DiagnosticsEngine &Diags = Context.getDiags();
3249   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3250     "cannot mangle this dependent name type yet");
3251   Diags.Report(Range.getBegin(), DiagID)
3252     << Range;
3253 }
3254 
3255 void MicrosoftCXXNameMangler::mangleType(
3256     const DependentTemplateSpecializationType *T, Qualifiers,
3257     SourceRange Range) {
3258   DiagnosticsEngine &Diags = Context.getDiags();
3259   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3260     "cannot mangle this dependent template specialization type yet");
3261   Diags.Report(Range.getBegin(), DiagID)
3262     << Range;
3263 }
3264 
3265 void MicrosoftCXXNameMangler::mangleType(const PackExpansionType *T, Qualifiers,
3266                                          SourceRange Range) {
3267   DiagnosticsEngine &Diags = Context.getDiags();
3268   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3269     "cannot mangle this pack expansion yet");
3270   Diags.Report(Range.getBegin(), DiagID)
3271     << Range;
3272 }
3273 
3274 void MicrosoftCXXNameMangler::mangleType(const TypeOfType *T, Qualifiers,
3275                                          SourceRange Range) {
3276   DiagnosticsEngine &Diags = Context.getDiags();
3277   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3278     "cannot mangle this typeof(type) yet");
3279   Diags.Report(Range.getBegin(), DiagID)
3280     << Range;
3281 }
3282 
3283 void MicrosoftCXXNameMangler::mangleType(const TypeOfExprType *T, Qualifiers,
3284                                          SourceRange Range) {
3285   DiagnosticsEngine &Diags = Context.getDiags();
3286   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3287     "cannot mangle this typeof(expression) yet");
3288   Diags.Report(Range.getBegin(), DiagID)
3289     << Range;
3290 }
3291 
3292 void MicrosoftCXXNameMangler::mangleType(const DecltypeType *T, Qualifiers,
3293                                          SourceRange Range) {
3294   DiagnosticsEngine &Diags = Context.getDiags();
3295   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3296     "cannot mangle this decltype() yet");
3297   Diags.Report(Range.getBegin(), DiagID)
3298     << Range;
3299 }
3300 
3301 void MicrosoftCXXNameMangler::mangleType(const UnaryTransformType *T,
3302                                          Qualifiers, SourceRange Range) {
3303   DiagnosticsEngine &Diags = Context.getDiags();
3304   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3305     "cannot mangle this unary transform type yet");
3306   Diags.Report(Range.getBegin(), DiagID)
3307     << Range;
3308 }
3309 
3310 void MicrosoftCXXNameMangler::mangleType(const AutoType *T, Qualifiers,
3311                                          SourceRange Range) {
3312   assert(T->getDeducedType().isNull() && "expecting a dependent type!");
3313 
3314   DiagnosticsEngine &Diags = Context.getDiags();
3315   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3316     "cannot mangle this 'auto' type yet");
3317   Diags.Report(Range.getBegin(), DiagID)
3318     << Range;
3319 }
3320 
3321 void MicrosoftCXXNameMangler::mangleType(
3322     const DeducedTemplateSpecializationType *T, Qualifiers, SourceRange Range) {
3323   assert(T->getDeducedType().isNull() && "expecting a dependent type!");
3324 
3325   DiagnosticsEngine &Diags = Context.getDiags();
3326   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3327     "cannot mangle this deduced class template specialization type yet");
3328   Diags.Report(Range.getBegin(), DiagID)
3329     << Range;
3330 }
3331 
3332 void MicrosoftCXXNameMangler::mangleType(const AtomicType *T, Qualifiers,
3333                                          SourceRange Range) {
3334   QualType ValueType = T->getValueType();
3335 
3336   llvm::SmallString<64> TemplateMangling;
3337   llvm::raw_svector_ostream Stream(TemplateMangling);
3338   MicrosoftCXXNameMangler Extra(Context, Stream);
3339   Stream << "?$";
3340   Extra.mangleSourceName("_Atomic");
3341   Extra.mangleType(ValueType, Range, QMM_Escape);
3342 
3343   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__clang"});
3344 }
3345 
3346 void MicrosoftCXXNameMangler::mangleType(const PipeType *T, Qualifiers,
3347                                          SourceRange Range) {
3348   QualType ElementType = T->getElementType();
3349 
3350   llvm::SmallString<64> TemplateMangling;
3351   llvm::raw_svector_ostream Stream(TemplateMangling);
3352   MicrosoftCXXNameMangler Extra(Context, Stream);
3353   Stream << "?$";
3354   Extra.mangleSourceName("ocl_pipe");
3355   Extra.mangleType(ElementType, Range, QMM_Escape);
3356   Extra.mangleIntegerLiteral(llvm::APSInt::get(T->isReadOnly()));
3357 
3358   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__clang"});
3359 }
3360 
3361 void MicrosoftMangleContextImpl::mangleCXXName(GlobalDecl GD,
3362                                                raw_ostream &Out) {
3363   const NamedDecl *D = cast<NamedDecl>(GD.getDecl());
3364   PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
3365                                  getASTContext().getSourceManager(),
3366                                  "Mangling declaration");
3367 
3368   msvc_hashing_ostream MHO(Out);
3369 
3370   if (auto *CD = dyn_cast<CXXConstructorDecl>(D)) {
3371     auto Type = GD.getCtorType();
3372     MicrosoftCXXNameMangler mangler(*this, MHO, CD, Type);
3373     return mangler.mangle(GD);
3374   }
3375 
3376   if (auto *DD = dyn_cast<CXXDestructorDecl>(D)) {
3377     auto Type = GD.getDtorType();
3378     MicrosoftCXXNameMangler mangler(*this, MHO, DD, Type);
3379     return mangler.mangle(GD);
3380   }
3381 
3382   MicrosoftCXXNameMangler Mangler(*this, MHO);
3383   return Mangler.mangle(GD);
3384 }
3385 
3386 void MicrosoftCXXNameMangler::mangleType(const BitIntType *T, Qualifiers,
3387                                          SourceRange Range) {
3388   llvm::SmallString<64> TemplateMangling;
3389   llvm::raw_svector_ostream Stream(TemplateMangling);
3390   MicrosoftCXXNameMangler Extra(Context, Stream);
3391   Stream << "?$";
3392   if (T->isUnsigned())
3393     Extra.mangleSourceName("_UBitInt");
3394   else
3395     Extra.mangleSourceName("_BitInt");
3396   Extra.mangleIntegerLiteral(llvm::APSInt::getUnsigned(T->getNumBits()));
3397 
3398   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__clang"});
3399 }
3400 
3401 void MicrosoftCXXNameMangler::mangleType(const DependentBitIntType *T,
3402                                          Qualifiers, SourceRange Range) {
3403   DiagnosticsEngine &Diags = Context.getDiags();
3404   unsigned DiagID = Diags.getCustomDiagID(
3405       DiagnosticsEngine::Error, "cannot mangle this DependentBitInt type yet");
3406   Diags.Report(Range.getBegin(), DiagID) << Range;
3407 }
3408 
3409 // <this-adjustment> ::= <no-adjustment> | <static-adjustment> |
3410 //                       <virtual-adjustment>
3411 // <no-adjustment>      ::= A # private near
3412 //                      ::= B # private far
3413 //                      ::= I # protected near
3414 //                      ::= J # protected far
3415 //                      ::= Q # public near
3416 //                      ::= R # public far
3417 // <static-adjustment>  ::= G <static-offset> # private near
3418 //                      ::= H <static-offset> # private far
3419 //                      ::= O <static-offset> # protected near
3420 //                      ::= P <static-offset> # protected far
3421 //                      ::= W <static-offset> # public near
3422 //                      ::= X <static-offset> # public far
3423 // <virtual-adjustment> ::= $0 <virtual-shift> <static-offset> # private near
3424 //                      ::= $1 <virtual-shift> <static-offset> # private far
3425 //                      ::= $2 <virtual-shift> <static-offset> # protected near
3426 //                      ::= $3 <virtual-shift> <static-offset> # protected far
3427 //                      ::= $4 <virtual-shift> <static-offset> # public near
3428 //                      ::= $5 <virtual-shift> <static-offset> # public far
3429 // <virtual-shift>      ::= <vtordisp-shift> | <vtordispex-shift>
3430 // <vtordisp-shift>     ::= <offset-to-vtordisp>
3431 // <vtordispex-shift>   ::= <offset-to-vbptr> <vbase-offset-offset>
3432 //                          <offset-to-vtordisp>
3433 static void mangleThunkThisAdjustment(AccessSpecifier AS,
3434                                       const ThisAdjustment &Adjustment,
3435                                       MicrosoftCXXNameMangler &Mangler,
3436                                       raw_ostream &Out) {
3437   if (!Adjustment.Virtual.isEmpty()) {
3438     Out << '$';
3439     char AccessSpec;
3440     switch (AS) {
3441     case AS_none:
3442       llvm_unreachable("Unsupported access specifier");
3443     case AS_private:
3444       AccessSpec = '0';
3445       break;
3446     case AS_protected:
3447       AccessSpec = '2';
3448       break;
3449     case AS_public:
3450       AccessSpec = '4';
3451     }
3452     if (Adjustment.Virtual.Microsoft.VBPtrOffset) {
3453       Out << 'R' << AccessSpec;
3454       Mangler.mangleNumber(
3455           static_cast<uint32_t>(Adjustment.Virtual.Microsoft.VBPtrOffset));
3456       Mangler.mangleNumber(
3457           static_cast<uint32_t>(Adjustment.Virtual.Microsoft.VBOffsetOffset));
3458       Mangler.mangleNumber(
3459           static_cast<uint32_t>(Adjustment.Virtual.Microsoft.VtordispOffset));
3460       Mangler.mangleNumber(static_cast<uint32_t>(Adjustment.NonVirtual));
3461     } else {
3462       Out << AccessSpec;
3463       Mangler.mangleNumber(
3464           static_cast<uint32_t>(Adjustment.Virtual.Microsoft.VtordispOffset));
3465       Mangler.mangleNumber(-static_cast<uint32_t>(Adjustment.NonVirtual));
3466     }
3467   } else if (Adjustment.NonVirtual != 0) {
3468     switch (AS) {
3469     case AS_none:
3470       llvm_unreachable("Unsupported access specifier");
3471     case AS_private:
3472       Out << 'G';
3473       break;
3474     case AS_protected:
3475       Out << 'O';
3476       break;
3477     case AS_public:
3478       Out << 'W';
3479     }
3480     Mangler.mangleNumber(-static_cast<uint32_t>(Adjustment.NonVirtual));
3481   } else {
3482     switch (AS) {
3483     case AS_none:
3484       llvm_unreachable("Unsupported access specifier");
3485     case AS_private:
3486       Out << 'A';
3487       break;
3488     case AS_protected:
3489       Out << 'I';
3490       break;
3491     case AS_public:
3492       Out << 'Q';
3493     }
3494   }
3495 }
3496 
3497 void MicrosoftMangleContextImpl::mangleVirtualMemPtrThunk(
3498     const CXXMethodDecl *MD, const MethodVFTableLocation &ML,
3499     raw_ostream &Out) {
3500   msvc_hashing_ostream MHO(Out);
3501   MicrosoftCXXNameMangler Mangler(*this, MHO);
3502   Mangler.getStream() << '?';
3503   Mangler.mangleVirtualMemPtrThunk(MD, ML);
3504 }
3505 
3506 void MicrosoftMangleContextImpl::mangleThunk(const CXXMethodDecl *MD,
3507                                              const ThunkInfo &Thunk,
3508                                              raw_ostream &Out) {
3509   msvc_hashing_ostream MHO(Out);
3510   MicrosoftCXXNameMangler Mangler(*this, MHO);
3511   Mangler.getStream() << '?';
3512   Mangler.mangleName(MD);
3513 
3514   // Usually the thunk uses the access specifier of the new method, but if this
3515   // is a covariant return thunk, then MSVC always uses the public access
3516   // specifier, and we do the same.
3517   AccessSpecifier AS = Thunk.Return.isEmpty() ? MD->getAccess() : AS_public;
3518   mangleThunkThisAdjustment(AS, Thunk.This, Mangler, MHO);
3519 
3520   if (!Thunk.Return.isEmpty())
3521     assert(Thunk.Method != nullptr &&
3522            "Thunk info should hold the overridee decl");
3523 
3524   const CXXMethodDecl *DeclForFPT = Thunk.Method ? Thunk.Method : MD;
3525   Mangler.mangleFunctionType(
3526       DeclForFPT->getType()->castAs<FunctionProtoType>(), MD);
3527 }
3528 
3529 void MicrosoftMangleContextImpl::mangleCXXDtorThunk(
3530     const CXXDestructorDecl *DD, CXXDtorType Type,
3531     const ThisAdjustment &Adjustment, raw_ostream &Out) {
3532   // FIXME: Actually, the dtor thunk should be emitted for vector deleting
3533   // dtors rather than scalar deleting dtors. Just use the vector deleting dtor
3534   // mangling manually until we support both deleting dtor types.
3535   assert(Type == Dtor_Deleting);
3536   msvc_hashing_ostream MHO(Out);
3537   MicrosoftCXXNameMangler Mangler(*this, MHO, DD, Type);
3538   Mangler.getStream() << "??_E";
3539   Mangler.mangleName(DD->getParent());
3540   mangleThunkThisAdjustment(DD->getAccess(), Adjustment, Mangler, MHO);
3541   Mangler.mangleFunctionType(DD->getType()->castAs<FunctionProtoType>(), DD);
3542 }
3543 
3544 void MicrosoftMangleContextImpl::mangleCXXVFTable(
3545     const CXXRecordDecl *Derived, ArrayRef<const CXXRecordDecl *> BasePath,
3546     raw_ostream &Out) {
3547   // <mangled-name> ::= ?_7 <class-name> <storage-class>
3548   //                    <cvr-qualifiers> [<name>] @
3549   // NOTE: <cvr-qualifiers> here is always 'B' (const). <storage-class>
3550   // is always '6' for vftables.
3551   msvc_hashing_ostream MHO(Out);
3552   MicrosoftCXXNameMangler Mangler(*this, MHO);
3553   if (Derived->hasAttr<DLLImportAttr>())
3554     Mangler.getStream() << "??_S";
3555   else
3556     Mangler.getStream() << "??_7";
3557   Mangler.mangleName(Derived);
3558   Mangler.getStream() << "6B"; // '6' for vftable, 'B' for const.
3559   for (const CXXRecordDecl *RD : BasePath)
3560     Mangler.mangleName(RD);
3561   Mangler.getStream() << '@';
3562 }
3563 
3564 void MicrosoftMangleContextImpl::mangleCXXVBTable(
3565     const CXXRecordDecl *Derived, ArrayRef<const CXXRecordDecl *> BasePath,
3566     raw_ostream &Out) {
3567   // <mangled-name> ::= ?_8 <class-name> <storage-class>
3568   //                    <cvr-qualifiers> [<name>] @
3569   // NOTE: <cvr-qualifiers> here is always 'B' (const). <storage-class>
3570   // is always '7' for vbtables.
3571   msvc_hashing_ostream MHO(Out);
3572   MicrosoftCXXNameMangler Mangler(*this, MHO);
3573   Mangler.getStream() << "??_8";
3574   Mangler.mangleName(Derived);
3575   Mangler.getStream() << "7B";  // '7' for vbtable, 'B' for const.
3576   for (const CXXRecordDecl *RD : BasePath)
3577     Mangler.mangleName(RD);
3578   Mangler.getStream() << '@';
3579 }
3580 
3581 void MicrosoftMangleContextImpl::mangleCXXRTTI(QualType T, raw_ostream &Out) {
3582   msvc_hashing_ostream MHO(Out);
3583   MicrosoftCXXNameMangler Mangler(*this, MHO);
3584   Mangler.getStream() << "??_R0";
3585   Mangler.mangleType(T, SourceRange(), MicrosoftCXXNameMangler::QMM_Result);
3586   Mangler.getStream() << "@8";
3587 }
3588 
3589 void MicrosoftMangleContextImpl::mangleCXXRTTIName(QualType T,
3590                                                    raw_ostream &Out) {
3591   MicrosoftCXXNameMangler Mangler(*this, Out);
3592   Mangler.getStream() << '.';
3593   Mangler.mangleType(T, SourceRange(), MicrosoftCXXNameMangler::QMM_Result);
3594 }
3595 
3596 void MicrosoftMangleContextImpl::mangleCXXVirtualDisplacementMap(
3597     const CXXRecordDecl *SrcRD, const CXXRecordDecl *DstRD, raw_ostream &Out) {
3598   msvc_hashing_ostream MHO(Out);
3599   MicrosoftCXXNameMangler Mangler(*this, MHO);
3600   Mangler.getStream() << "??_K";
3601   Mangler.mangleName(SrcRD);
3602   Mangler.getStream() << "$C";
3603   Mangler.mangleName(DstRD);
3604 }
3605 
3606 void MicrosoftMangleContextImpl::mangleCXXThrowInfo(QualType T, bool IsConst,
3607                                                     bool IsVolatile,
3608                                                     bool IsUnaligned,
3609                                                     uint32_t NumEntries,
3610                                                     raw_ostream &Out) {
3611   msvc_hashing_ostream MHO(Out);
3612   MicrosoftCXXNameMangler Mangler(*this, MHO);
3613   Mangler.getStream() << "_TI";
3614   if (IsConst)
3615     Mangler.getStream() << 'C';
3616   if (IsVolatile)
3617     Mangler.getStream() << 'V';
3618   if (IsUnaligned)
3619     Mangler.getStream() << 'U';
3620   Mangler.getStream() << NumEntries;
3621   Mangler.mangleType(T, SourceRange(), MicrosoftCXXNameMangler::QMM_Result);
3622 }
3623 
3624 void MicrosoftMangleContextImpl::mangleCXXCatchableTypeArray(
3625     QualType T, uint32_t NumEntries, raw_ostream &Out) {
3626   msvc_hashing_ostream MHO(Out);
3627   MicrosoftCXXNameMangler Mangler(*this, MHO);
3628   Mangler.getStream() << "_CTA";
3629   Mangler.getStream() << NumEntries;
3630   Mangler.mangleType(T, SourceRange(), MicrosoftCXXNameMangler::QMM_Result);
3631 }
3632 
3633 void MicrosoftMangleContextImpl::mangleCXXCatchableType(
3634     QualType T, const CXXConstructorDecl *CD, CXXCtorType CT, uint32_t Size,
3635     uint32_t NVOffset, int32_t VBPtrOffset, uint32_t VBIndex,
3636     raw_ostream &Out) {
3637   MicrosoftCXXNameMangler Mangler(*this, Out);
3638   Mangler.getStream() << "_CT";
3639 
3640   llvm::SmallString<64> RTTIMangling;
3641   {
3642     llvm::raw_svector_ostream Stream(RTTIMangling);
3643     msvc_hashing_ostream MHO(Stream);
3644     mangleCXXRTTI(T, MHO);
3645   }
3646   Mangler.getStream() << RTTIMangling;
3647 
3648   // VS2015 and VS2017.1 omit the copy-constructor in the mangled name but
3649   // both older and newer versions include it.
3650   // FIXME: It is known that the Ctor is present in 2013, and in 2017.7
3651   // (_MSC_VER 1914) and newer, and that it's omitted in 2015 and 2017.4
3652   // (_MSC_VER 1911), but it's unknown when exactly it reappeared (1914?
3653   // Or 1912, 1913 already?).
3654   bool OmitCopyCtor = getASTContext().getLangOpts().isCompatibleWithMSVC(
3655                           LangOptions::MSVC2015) &&
3656                       !getASTContext().getLangOpts().isCompatibleWithMSVC(
3657                           LangOptions::MSVC2017_7);
3658   llvm::SmallString<64> CopyCtorMangling;
3659   if (!OmitCopyCtor && CD) {
3660     llvm::raw_svector_ostream Stream(CopyCtorMangling);
3661     msvc_hashing_ostream MHO(Stream);
3662     mangleCXXName(GlobalDecl(CD, CT), MHO);
3663   }
3664   Mangler.getStream() << CopyCtorMangling;
3665 
3666   Mangler.getStream() << Size;
3667   if (VBPtrOffset == -1) {
3668     if (NVOffset) {
3669       Mangler.getStream() << NVOffset;
3670     }
3671   } else {
3672     Mangler.getStream() << NVOffset;
3673     Mangler.getStream() << VBPtrOffset;
3674     Mangler.getStream() << VBIndex;
3675   }
3676 }
3677 
3678 void MicrosoftMangleContextImpl::mangleCXXRTTIBaseClassDescriptor(
3679     const CXXRecordDecl *Derived, uint32_t NVOffset, int32_t VBPtrOffset,
3680     uint32_t VBTableOffset, uint32_t Flags, raw_ostream &Out) {
3681   msvc_hashing_ostream MHO(Out);
3682   MicrosoftCXXNameMangler Mangler(*this, MHO);
3683   Mangler.getStream() << "??_R1";
3684   Mangler.mangleNumber(NVOffset);
3685   Mangler.mangleNumber(VBPtrOffset);
3686   Mangler.mangleNumber(VBTableOffset);
3687   Mangler.mangleNumber(Flags);
3688   Mangler.mangleName(Derived);
3689   Mangler.getStream() << "8";
3690 }
3691 
3692 void MicrosoftMangleContextImpl::mangleCXXRTTIBaseClassArray(
3693     const CXXRecordDecl *Derived, raw_ostream &Out) {
3694   msvc_hashing_ostream MHO(Out);
3695   MicrosoftCXXNameMangler Mangler(*this, MHO);
3696   Mangler.getStream() << "??_R2";
3697   Mangler.mangleName(Derived);
3698   Mangler.getStream() << "8";
3699 }
3700 
3701 void MicrosoftMangleContextImpl::mangleCXXRTTIClassHierarchyDescriptor(
3702     const CXXRecordDecl *Derived, raw_ostream &Out) {
3703   msvc_hashing_ostream MHO(Out);
3704   MicrosoftCXXNameMangler Mangler(*this, MHO);
3705   Mangler.getStream() << "??_R3";
3706   Mangler.mangleName(Derived);
3707   Mangler.getStream() << "8";
3708 }
3709 
3710 void MicrosoftMangleContextImpl::mangleCXXRTTICompleteObjectLocator(
3711     const CXXRecordDecl *Derived, ArrayRef<const CXXRecordDecl *> BasePath,
3712     raw_ostream &Out) {
3713   // <mangled-name> ::= ?_R4 <class-name> <storage-class>
3714   //                    <cvr-qualifiers> [<name>] @
3715   // NOTE: <cvr-qualifiers> here is always 'B' (const). <storage-class>
3716   // is always '6' for vftables.
3717   llvm::SmallString<64> VFTableMangling;
3718   llvm::raw_svector_ostream Stream(VFTableMangling);
3719   mangleCXXVFTable(Derived, BasePath, Stream);
3720 
3721   if (VFTableMangling.startswith("??@")) {
3722     assert(VFTableMangling.endswith("@"));
3723     Out << VFTableMangling << "??_R4@";
3724     return;
3725   }
3726 
3727   assert(VFTableMangling.startswith("??_7") ||
3728          VFTableMangling.startswith("??_S"));
3729 
3730   Out << "??_R4" << VFTableMangling.str().drop_front(4);
3731 }
3732 
3733 void MicrosoftMangleContextImpl::mangleSEHFilterExpression(
3734     GlobalDecl EnclosingDecl, raw_ostream &Out) {
3735   msvc_hashing_ostream MHO(Out);
3736   MicrosoftCXXNameMangler Mangler(*this, MHO);
3737   // The function body is in the same comdat as the function with the handler,
3738   // so the numbering here doesn't have to be the same across TUs.
3739   //
3740   // <mangled-name> ::= ?filt$ <filter-number> @0
3741   Mangler.getStream() << "?filt$" << SEHFilterIds[EnclosingDecl]++ << "@0@";
3742   Mangler.mangleName(EnclosingDecl);
3743 }
3744 
3745 void MicrosoftMangleContextImpl::mangleSEHFinallyBlock(
3746     GlobalDecl EnclosingDecl, raw_ostream &Out) {
3747   msvc_hashing_ostream MHO(Out);
3748   MicrosoftCXXNameMangler Mangler(*this, MHO);
3749   // The function body is in the same comdat as the function with the handler,
3750   // so the numbering here doesn't have to be the same across TUs.
3751   //
3752   // <mangled-name> ::= ?fin$ <filter-number> @0
3753   Mangler.getStream() << "?fin$" << SEHFinallyIds[EnclosingDecl]++ << "@0@";
3754   Mangler.mangleName(EnclosingDecl);
3755 }
3756 
3757 void MicrosoftMangleContextImpl::mangleTypeName(QualType T, raw_ostream &Out) {
3758   // This is just a made up unique string for the purposes of tbaa.  undname
3759   // does *not* know how to demangle it.
3760   MicrosoftCXXNameMangler Mangler(*this, Out);
3761   Mangler.getStream() << '?';
3762   Mangler.mangleType(T, SourceRange());
3763 }
3764 
3765 void MicrosoftMangleContextImpl::mangleReferenceTemporary(
3766     const VarDecl *VD, unsigned ManglingNumber, raw_ostream &Out) {
3767   msvc_hashing_ostream MHO(Out);
3768   MicrosoftCXXNameMangler Mangler(*this, MHO);
3769 
3770   Mangler.getStream() << "?$RT" << ManglingNumber << '@';
3771   Mangler.mangle(VD, "");
3772 }
3773 
3774 void MicrosoftMangleContextImpl::mangleThreadSafeStaticGuardVariable(
3775     const VarDecl *VD, unsigned GuardNum, raw_ostream &Out) {
3776   msvc_hashing_ostream MHO(Out);
3777   MicrosoftCXXNameMangler Mangler(*this, MHO);
3778 
3779   Mangler.getStream() << "?$TSS" << GuardNum << '@';
3780   Mangler.mangleNestedName(VD);
3781   Mangler.getStream() << "@4HA";
3782 }
3783 
3784 void MicrosoftMangleContextImpl::mangleStaticGuardVariable(const VarDecl *VD,
3785                                                            raw_ostream &Out) {
3786   // <guard-name> ::= ?_B <postfix> @5 <scope-depth>
3787   //              ::= ?__J <postfix> @5 <scope-depth>
3788   //              ::= ?$S <guard-num> @ <postfix> @4IA
3789 
3790   // The first mangling is what MSVC uses to guard static locals in inline
3791   // functions.  It uses a different mangling in external functions to support
3792   // guarding more than 32 variables.  MSVC rejects inline functions with more
3793   // than 32 static locals.  We don't fully implement the second mangling
3794   // because those guards are not externally visible, and instead use LLVM's
3795   // default renaming when creating a new guard variable.
3796   msvc_hashing_ostream MHO(Out);
3797   MicrosoftCXXNameMangler Mangler(*this, MHO);
3798 
3799   bool Visible = VD->isExternallyVisible();
3800   if (Visible) {
3801     Mangler.getStream() << (VD->getTLSKind() ? "??__J" : "??_B");
3802   } else {
3803     Mangler.getStream() << "?$S1@";
3804   }
3805   unsigned ScopeDepth = 0;
3806   if (Visible && !getNextDiscriminator(VD, ScopeDepth))
3807     // If we do not have a discriminator and are emitting a guard variable for
3808     // use at global scope, then mangling the nested name will not be enough to
3809     // remove ambiguities.
3810     Mangler.mangle(VD, "");
3811   else
3812     Mangler.mangleNestedName(VD);
3813   Mangler.getStream() << (Visible ? "@5" : "@4IA");
3814   if (ScopeDepth)
3815     Mangler.mangleNumber(ScopeDepth);
3816 }
3817 
3818 void MicrosoftMangleContextImpl::mangleInitFiniStub(const VarDecl *D,
3819                                                     char CharCode,
3820                                                     raw_ostream &Out) {
3821   msvc_hashing_ostream MHO(Out);
3822   MicrosoftCXXNameMangler Mangler(*this, MHO);
3823   Mangler.getStream() << "??__" << CharCode;
3824   if (D->isStaticDataMember()) {
3825     Mangler.getStream() << '?';
3826     Mangler.mangleName(D);
3827     Mangler.mangleVariableEncoding(D);
3828     Mangler.getStream() << "@@";
3829   } else {
3830     Mangler.mangleName(D);
3831   }
3832   // This is the function class mangling.  These stubs are global, non-variadic,
3833   // cdecl functions that return void and take no args.
3834   Mangler.getStream() << "YAXXZ";
3835 }
3836 
3837 void MicrosoftMangleContextImpl::mangleDynamicInitializer(const VarDecl *D,
3838                                                           raw_ostream &Out) {
3839   // <initializer-name> ::= ?__E <name> YAXXZ
3840   mangleInitFiniStub(D, 'E', Out);
3841 }
3842 
3843 void
3844 MicrosoftMangleContextImpl::mangleDynamicAtExitDestructor(const VarDecl *D,
3845                                                           raw_ostream &Out) {
3846   // <destructor-name> ::= ?__F <name> YAXXZ
3847   mangleInitFiniStub(D, 'F', Out);
3848 }
3849 
3850 void MicrosoftMangleContextImpl::mangleStringLiteral(const StringLiteral *SL,
3851                                                      raw_ostream &Out) {
3852   // <char-type> ::= 0   # char, char16_t, char32_t
3853   //                     # (little endian char data in mangling)
3854   //             ::= 1   # wchar_t (big endian char data in mangling)
3855   //
3856   // <literal-length> ::= <non-negative integer>  # the length of the literal
3857   //
3858   // <encoded-crc>    ::= <hex digit>+ @          # crc of the literal including
3859   //                                              # trailing null bytes
3860   //
3861   // <encoded-string> ::= <simple character>           # uninteresting character
3862   //                  ::= '?$' <hex digit> <hex digit> # these two nibbles
3863   //                                                   # encode the byte for the
3864   //                                                   # character
3865   //                  ::= '?' [a-z]                    # \xe1 - \xfa
3866   //                  ::= '?' [A-Z]                    # \xc1 - \xda
3867   //                  ::= '?' [0-9]                    # [,/\:. \n\t'-]
3868   //
3869   // <literal> ::= '??_C@_' <char-type> <literal-length> <encoded-crc>
3870   //               <encoded-string> '@'
3871   MicrosoftCXXNameMangler Mangler(*this, Out);
3872   Mangler.getStream() << "??_C@_";
3873 
3874   // The actual string length might be different from that of the string literal
3875   // in cases like:
3876   // char foo[3] = "foobar";
3877   // char bar[42] = "foobar";
3878   // Where it is truncated or zero-padded to fit the array. This is the length
3879   // used for mangling, and any trailing null-bytes also need to be mangled.
3880   unsigned StringLength = getASTContext()
3881                               .getAsConstantArrayType(SL->getType())
3882                               ->getSize()
3883                               .getZExtValue();
3884   unsigned StringByteLength = StringLength * SL->getCharByteWidth();
3885 
3886   // <char-type>: The "kind" of string literal is encoded into the mangled name.
3887   if (SL->isWide())
3888     Mangler.getStream() << '1';
3889   else
3890     Mangler.getStream() << '0';
3891 
3892   // <literal-length>: The next part of the mangled name consists of the length
3893   // of the string in bytes.
3894   Mangler.mangleNumber(StringByteLength);
3895 
3896   auto GetLittleEndianByte = [&SL](unsigned Index) {
3897     unsigned CharByteWidth = SL->getCharByteWidth();
3898     if (Index / CharByteWidth >= SL->getLength())
3899       return static_cast<char>(0);
3900     uint32_t CodeUnit = SL->getCodeUnit(Index / CharByteWidth);
3901     unsigned OffsetInCodeUnit = Index % CharByteWidth;
3902     return static_cast<char>((CodeUnit >> (8 * OffsetInCodeUnit)) & 0xff);
3903   };
3904 
3905   auto GetBigEndianByte = [&SL](unsigned Index) {
3906     unsigned CharByteWidth = SL->getCharByteWidth();
3907     if (Index / CharByteWidth >= SL->getLength())
3908       return static_cast<char>(0);
3909     uint32_t CodeUnit = SL->getCodeUnit(Index / CharByteWidth);
3910     unsigned OffsetInCodeUnit = (CharByteWidth - 1) - (Index % CharByteWidth);
3911     return static_cast<char>((CodeUnit >> (8 * OffsetInCodeUnit)) & 0xff);
3912   };
3913 
3914   // CRC all the bytes of the StringLiteral.
3915   llvm::JamCRC JC;
3916   for (unsigned I = 0, E = StringByteLength; I != E; ++I)
3917     JC.update(GetLittleEndianByte(I));
3918 
3919   // <encoded-crc>: The CRC is encoded utilizing the standard number mangling
3920   // scheme.
3921   Mangler.mangleNumber(JC.getCRC());
3922 
3923   // <encoded-string>: The mangled name also contains the first 32 bytes
3924   // (including null-terminator bytes) of the encoded StringLiteral.
3925   // Each character is encoded by splitting them into bytes and then encoding
3926   // the constituent bytes.
3927   auto MangleByte = [&Mangler](char Byte) {
3928     // There are five different manglings for characters:
3929     // - [a-zA-Z0-9_$]: A one-to-one mapping.
3930     // - ?[a-z]: The range from \xe1 to \xfa.
3931     // - ?[A-Z]: The range from \xc1 to \xda.
3932     // - ?[0-9]: The set of [,/\:. \n\t'-].
3933     // - ?$XX: A fallback which maps nibbles.
3934     if (isAsciiIdentifierContinue(Byte, /*AllowDollar=*/true)) {
3935       Mangler.getStream() << Byte;
3936     } else if (isLetter(Byte & 0x7f)) {
3937       Mangler.getStream() << '?' << static_cast<char>(Byte & 0x7f);
3938     } else {
3939       const char SpecialChars[] = {',', '/',  '\\', ':',  '.',
3940                                    ' ', '\n', '\t', '\'', '-'};
3941       const char *Pos = llvm::find(SpecialChars, Byte);
3942       if (Pos != std::end(SpecialChars)) {
3943         Mangler.getStream() << '?' << (Pos - std::begin(SpecialChars));
3944       } else {
3945         Mangler.getStream() << "?$";
3946         Mangler.getStream() << static_cast<char>('A' + ((Byte >> 4) & 0xf));
3947         Mangler.getStream() << static_cast<char>('A' + (Byte & 0xf));
3948       }
3949     }
3950   };
3951 
3952   // Enforce our 32 bytes max, except wchar_t which gets 32 chars instead.
3953   unsigned MaxBytesToMangle = SL->isWide() ? 64U : 32U;
3954   unsigned NumBytesToMangle = std::min(MaxBytesToMangle, StringByteLength);
3955   for (unsigned I = 0; I != NumBytesToMangle; ++I) {
3956     if (SL->isWide())
3957       MangleByte(GetBigEndianByte(I));
3958     else
3959       MangleByte(GetLittleEndianByte(I));
3960   }
3961 
3962   Mangler.getStream() << '@';
3963 }
3964 
3965 MicrosoftMangleContext *MicrosoftMangleContext::create(ASTContext &Context,
3966                                                        DiagnosticsEngine &Diags,
3967                                                        bool IsAux) {
3968   return new MicrosoftMangleContextImpl(Context, Diags, IsAux);
3969 }
3970