xref: /freebsd/contrib/llvm-project/clang/lib/AST/MicrosoftMangle.cpp (revision 9dba64be9536c28e4800e06512b7f29b43ade345)
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/Mangle.h"
14 #include "clang/AST/ASTContext.h"
15 #include "clang/AST/Attr.h"
16 #include "clang/AST/CXXInheritance.h"
17 #include "clang/AST/CharUnits.h"
18 #include "clang/AST/Decl.h"
19 #include "clang/AST/DeclCXX.h"
20 #include "clang/AST/DeclObjC.h"
21 #include "clang/AST/DeclOpenMP.h"
22 #include "clang/AST/DeclTemplate.h"
23 #include "clang/AST/Expr.h"
24 #include "clang/AST/ExprCXX.h"
25 #include "clang/AST/VTableBuilder.h"
26 #include "clang/Basic/ABI.h"
27 #include "clang/Basic/DiagnosticOptions.h"
28 #include "clang/Basic/TargetInfo.h"
29 #include "llvm/ADT/StringExtras.h"
30 #include "llvm/Support/CRC.h"
31 #include "llvm/Support/MD5.h"
32 #include "llvm/Support/MathExtras.h"
33 #include "llvm/Support/StringSaver.h"
34 #include "llvm/Support/xxhash.h"
35 
36 using namespace clang;
37 
38 namespace {
39 
40 struct msvc_hashing_ostream : public llvm::raw_svector_ostream {
41   raw_ostream &OS;
42   llvm::SmallString<64> Buffer;
43 
44   msvc_hashing_ostream(raw_ostream &OS)
45       : llvm::raw_svector_ostream(Buffer), OS(OS) {}
46   ~msvc_hashing_ostream() override {
47     StringRef MangledName = str();
48     bool StartsWithEscape = MangledName.startswith("\01");
49     if (StartsWithEscape)
50       MangledName = MangledName.drop_front(1);
51     if (MangledName.size() <= 4096) {
52       OS << str();
53       return;
54     }
55 
56     llvm::MD5 Hasher;
57     llvm::MD5::MD5Result Hash;
58     Hasher.update(MangledName);
59     Hasher.final(Hash);
60 
61     SmallString<32> HexString;
62     llvm::MD5::stringifyResult(Hash, HexString);
63 
64     if (StartsWithEscape)
65       OS << '\01';
66     OS << "??@" << HexString << '@';
67   }
68 };
69 
70 static const DeclContext *
71 getLambdaDefaultArgumentDeclContext(const Decl *D) {
72   if (const auto *RD = dyn_cast<CXXRecordDecl>(D))
73     if (RD->isLambda())
74       if (const auto *Parm =
75               dyn_cast_or_null<ParmVarDecl>(RD->getLambdaContextDecl()))
76         return Parm->getDeclContext();
77   return nullptr;
78 }
79 
80 /// Retrieve the declaration context that should be used when mangling
81 /// the given declaration.
82 static const DeclContext *getEffectiveDeclContext(const Decl *D) {
83   // The ABI assumes that lambda closure types that occur within
84   // default arguments live in the context of the function. However, due to
85   // the way in which Clang parses and creates function declarations, this is
86   // not the case: the lambda closure type ends up living in the context
87   // where the function itself resides, because the function declaration itself
88   // had not yet been created. Fix the context here.
89   if (const auto *LDADC = getLambdaDefaultArgumentDeclContext(D))
90     return LDADC;
91 
92   // Perform the same check for block literals.
93   if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
94     if (ParmVarDecl *ContextParam =
95             dyn_cast_or_null<ParmVarDecl>(BD->getBlockManglingContextDecl()))
96       return ContextParam->getDeclContext();
97   }
98 
99   const DeclContext *DC = D->getDeclContext();
100   if (isa<CapturedDecl>(DC) || isa<OMPDeclareReductionDecl>(DC) ||
101       isa<OMPDeclareMapperDecl>(DC)) {
102     return getEffectiveDeclContext(cast<Decl>(DC));
103   }
104 
105   return DC->getRedeclContext();
106 }
107 
108 static const DeclContext *getEffectiveParentContext(const DeclContext *DC) {
109   return getEffectiveDeclContext(cast<Decl>(DC));
110 }
111 
112 static const FunctionDecl *getStructor(const NamedDecl *ND) {
113   if (const auto *FTD = dyn_cast<FunctionTemplateDecl>(ND))
114     return FTD->getTemplatedDecl()->getCanonicalDecl();
115 
116   const auto *FD = cast<FunctionDecl>(ND);
117   if (const auto *FTD = FD->getPrimaryTemplate())
118     return FTD->getTemplatedDecl()->getCanonicalDecl();
119 
120   return FD->getCanonicalDecl();
121 }
122 
123 /// MicrosoftMangleContextImpl - Overrides the default MangleContext for the
124 /// Microsoft Visual C++ ABI.
125 class MicrosoftMangleContextImpl : public MicrosoftMangleContext {
126   typedef std::pair<const DeclContext *, IdentifierInfo *> DiscriminatorKeyTy;
127   llvm::DenseMap<DiscriminatorKeyTy, unsigned> Discriminator;
128   llvm::DenseMap<const NamedDecl *, unsigned> Uniquifier;
129   llvm::DenseMap<const CXXRecordDecl *, unsigned> LambdaIds;
130   llvm::DenseMap<const NamedDecl *, unsigned> SEHFilterIds;
131   llvm::DenseMap<const NamedDecl *, unsigned> SEHFinallyIds;
132   SmallString<16> AnonymousNamespaceHash;
133 
134 public:
135   MicrosoftMangleContextImpl(ASTContext &Context, DiagnosticsEngine &Diags);
136   bool shouldMangleCXXName(const NamedDecl *D) override;
137   bool shouldMangleStringLiteral(const StringLiteral *SL) override;
138   void mangleCXXName(const NamedDecl *D, raw_ostream &Out) override;
139   void mangleVirtualMemPtrThunk(const CXXMethodDecl *MD,
140                                 const MethodVFTableLocation &ML,
141                                 raw_ostream &Out) override;
142   void mangleThunk(const CXXMethodDecl *MD, const ThunkInfo &Thunk,
143                    raw_ostream &) override;
144   void mangleCXXDtorThunk(const CXXDestructorDecl *DD, CXXDtorType Type,
145                           const ThisAdjustment &ThisAdjustment,
146                           raw_ostream &) override;
147   void mangleCXXVFTable(const CXXRecordDecl *Derived,
148                         ArrayRef<const CXXRecordDecl *> BasePath,
149                         raw_ostream &Out) override;
150   void mangleCXXVBTable(const CXXRecordDecl *Derived,
151                         ArrayRef<const CXXRecordDecl *> BasePath,
152                         raw_ostream &Out) override;
153   void mangleCXXVirtualDisplacementMap(const CXXRecordDecl *SrcRD,
154                                        const CXXRecordDecl *DstRD,
155                                        raw_ostream &Out) override;
156   void mangleCXXThrowInfo(QualType T, bool IsConst, bool IsVolatile,
157                           bool IsUnaligned, uint32_t NumEntries,
158                           raw_ostream &Out) override;
159   void mangleCXXCatchableTypeArray(QualType T, uint32_t NumEntries,
160                                    raw_ostream &Out) override;
161   void mangleCXXCatchableType(QualType T, const CXXConstructorDecl *CD,
162                               CXXCtorType CT, uint32_t Size, uint32_t NVOffset,
163                               int32_t VBPtrOffset, uint32_t VBIndex,
164                               raw_ostream &Out) override;
165   void mangleCXXRTTI(QualType T, raw_ostream &Out) override;
166   void mangleCXXRTTIName(QualType T, raw_ostream &Out) override;
167   void mangleCXXRTTIBaseClassDescriptor(const CXXRecordDecl *Derived,
168                                         uint32_t NVOffset, int32_t VBPtrOffset,
169                                         uint32_t VBTableOffset, uint32_t Flags,
170                                         raw_ostream &Out) override;
171   void mangleCXXRTTIBaseClassArray(const CXXRecordDecl *Derived,
172                                    raw_ostream &Out) override;
173   void mangleCXXRTTIClassHierarchyDescriptor(const CXXRecordDecl *Derived,
174                                              raw_ostream &Out) override;
175   void
176   mangleCXXRTTICompleteObjectLocator(const CXXRecordDecl *Derived,
177                                      ArrayRef<const CXXRecordDecl *> BasePath,
178                                      raw_ostream &Out) override;
179   void mangleTypeName(QualType T, raw_ostream &) override;
180   void mangleCXXCtor(const CXXConstructorDecl *D, CXXCtorType Type,
181                      raw_ostream &) override;
182   void mangleCXXDtor(const CXXDestructorDecl *D, CXXDtorType Type,
183                      raw_ostream &) override;
184   void mangleReferenceTemporary(const VarDecl *, unsigned ManglingNumber,
185                                 raw_ostream &) override;
186   void mangleStaticGuardVariable(const VarDecl *D, raw_ostream &Out) override;
187   void mangleThreadSafeStaticGuardVariable(const VarDecl *D, unsigned GuardNum,
188                                            raw_ostream &Out) override;
189   void mangleDynamicInitializer(const VarDecl *D, raw_ostream &Out) override;
190   void mangleDynamicAtExitDestructor(const VarDecl *D,
191                                      raw_ostream &Out) override;
192   void mangleSEHFilterExpression(const NamedDecl *EnclosingDecl,
193                                  raw_ostream &Out) override;
194   void mangleSEHFinallyBlock(const NamedDecl *EnclosingDecl,
195                              raw_ostream &Out) override;
196   void mangleStringLiteral(const StringLiteral *SL, raw_ostream &Out) override;
197   bool getNextDiscriminator(const NamedDecl *ND, unsigned &disc) {
198     const DeclContext *DC = getEffectiveDeclContext(ND);
199     if (!DC->isFunctionOrMethod())
200       return false;
201 
202     // Lambda closure types are already numbered, give out a phony number so
203     // that they demangle nicely.
204     if (const auto *RD = dyn_cast<CXXRecordDecl>(ND)) {
205       if (RD->isLambda()) {
206         disc = 1;
207         return true;
208       }
209     }
210 
211     // Use the canonical number for externally visible decls.
212     if (ND->isExternallyVisible()) {
213       disc = getASTContext().getManglingNumber(ND);
214       return true;
215     }
216 
217     // Anonymous tags are already numbered.
218     if (const TagDecl *Tag = dyn_cast<TagDecl>(ND)) {
219       if (!Tag->hasNameForLinkage() &&
220           !getASTContext().getDeclaratorForUnnamedTagDecl(Tag) &&
221           !getASTContext().getTypedefNameForUnnamedTagDecl(Tag))
222         return false;
223     }
224 
225     // Make up a reasonable number for internal decls.
226     unsigned &discriminator = Uniquifier[ND];
227     if (!discriminator)
228       discriminator = ++Discriminator[std::make_pair(DC, ND->getIdentifier())];
229     disc = discriminator + 1;
230     return true;
231   }
232 
233   unsigned getLambdaId(const CXXRecordDecl *RD) {
234     assert(RD->isLambda() && "RD must be a lambda!");
235     assert(!RD->isExternallyVisible() && "RD must not be visible!");
236     assert(RD->getLambdaManglingNumber() == 0 &&
237            "RD must not have a mangling number!");
238     std::pair<llvm::DenseMap<const CXXRecordDecl *, unsigned>::iterator, bool>
239         Result = LambdaIds.insert(std::make_pair(RD, LambdaIds.size()));
240     return Result.first->second;
241   }
242 
243   /// Return a character sequence that is (somewhat) unique to the TU suitable
244   /// for mangling anonymous namespaces.
245   StringRef getAnonymousNamespaceHash() const {
246     return AnonymousNamespaceHash;
247   }
248 
249 private:
250   void mangleInitFiniStub(const VarDecl *D, char CharCode, raw_ostream &Out);
251 };
252 
253 /// MicrosoftCXXNameMangler - Manage the mangling of a single name for the
254 /// Microsoft Visual C++ ABI.
255 class MicrosoftCXXNameMangler {
256   MicrosoftMangleContextImpl &Context;
257   raw_ostream &Out;
258 
259   /// The "structor" is the top-level declaration being mangled, if
260   /// that's not a template specialization; otherwise it's the pattern
261   /// for that specialization.
262   const NamedDecl *Structor;
263   unsigned StructorType;
264 
265   typedef llvm::SmallVector<std::string, 10> BackRefVec;
266   BackRefVec NameBackReferences;
267 
268   typedef llvm::DenseMap<const void *, unsigned> ArgBackRefMap;
269   ArgBackRefMap FunArgBackReferences;
270   ArgBackRefMap TemplateArgBackReferences;
271 
272   typedef llvm::DenseMap<const void *, StringRef> TemplateArgStringMap;
273   TemplateArgStringMap TemplateArgStrings;
274   llvm::StringSaver TemplateArgStringStorage;
275   llvm::BumpPtrAllocator TemplateArgStringStorageAlloc;
276 
277   typedef std::set<std::pair<int, bool>> PassObjectSizeArgsSet;
278   PassObjectSizeArgsSet PassObjectSizeArgs;
279 
280   ASTContext &getASTContext() const { return Context.getASTContext(); }
281 
282   // FIXME: If we add support for __ptr32/64 qualifiers, then we should push
283   // this check into mangleQualifiers().
284   const bool PointersAre64Bit;
285 
286 public:
287   enum QualifierMangleMode { QMM_Drop, QMM_Mangle, QMM_Escape, QMM_Result };
288 
289   MicrosoftCXXNameMangler(MicrosoftMangleContextImpl &C, raw_ostream &Out_)
290       : Context(C), Out(Out_), Structor(nullptr), StructorType(-1),
291         TemplateArgStringStorage(TemplateArgStringStorageAlloc),
292         PointersAre64Bit(C.getASTContext().getTargetInfo().getPointerWidth(0) ==
293                          64) {}
294 
295   MicrosoftCXXNameMangler(MicrosoftMangleContextImpl &C, raw_ostream &Out_,
296                           const CXXConstructorDecl *D, CXXCtorType Type)
297       : Context(C), Out(Out_), Structor(getStructor(D)), StructorType(Type),
298         TemplateArgStringStorage(TemplateArgStringStorageAlloc),
299         PointersAre64Bit(C.getASTContext().getTargetInfo().getPointerWidth(0) ==
300                          64) {}
301 
302   MicrosoftCXXNameMangler(MicrosoftMangleContextImpl &C, raw_ostream &Out_,
303                           const CXXDestructorDecl *D, CXXDtorType Type)
304       : Context(C), Out(Out_), Structor(getStructor(D)), StructorType(Type),
305         TemplateArgStringStorage(TemplateArgStringStorageAlloc),
306         PointersAre64Bit(C.getASTContext().getTargetInfo().getPointerWidth(0) ==
307                          64) {}
308 
309   raw_ostream &getStream() const { return Out; }
310 
311   void mangle(const NamedDecl *D, StringRef Prefix = "?");
312   void mangleName(const NamedDecl *ND);
313   void mangleFunctionEncoding(const FunctionDecl *FD, bool ShouldMangle);
314   void mangleVariableEncoding(const VarDecl *VD);
315   void mangleMemberDataPointer(const CXXRecordDecl *RD, const ValueDecl *VD);
316   void mangleMemberFunctionPointer(const CXXRecordDecl *RD,
317                                    const CXXMethodDecl *MD);
318   void mangleVirtualMemPtrThunk(const CXXMethodDecl *MD,
319                                 const MethodVFTableLocation &ML);
320   void mangleNumber(int64_t Number);
321   void mangleTagTypeKind(TagTypeKind TK);
322   void mangleArtificialTagType(TagTypeKind TK, StringRef UnqualifiedName,
323                               ArrayRef<StringRef> NestedNames = None);
324   void mangleAddressSpaceType(QualType T, Qualifiers Quals, SourceRange Range);
325   void mangleType(QualType T, SourceRange Range,
326                   QualifierMangleMode QMM = QMM_Mangle);
327   void mangleFunctionType(const FunctionType *T,
328                           const FunctionDecl *D = nullptr,
329                           bool ForceThisQuals = false,
330                           bool MangleExceptionSpec = true);
331   void mangleNestedName(const NamedDecl *ND);
332 
333 private:
334   bool isStructorDecl(const NamedDecl *ND) const {
335     return ND == Structor || getStructor(ND) == Structor;
336   }
337 
338   void mangleUnqualifiedName(const NamedDecl *ND) {
339     mangleUnqualifiedName(ND, ND->getDeclName());
340   }
341   void mangleUnqualifiedName(const NamedDecl *ND, DeclarationName Name);
342   void mangleSourceName(StringRef Name);
343   void mangleOperatorName(OverloadedOperatorKind OO, SourceLocation Loc);
344   void mangleCXXDtorType(CXXDtorType T);
345   void mangleQualifiers(Qualifiers Quals, bool IsMember);
346   void mangleRefQualifier(RefQualifierKind RefQualifier);
347   void manglePointerCVQualifiers(Qualifiers Quals);
348   void manglePointerExtQualifiers(Qualifiers Quals, QualType PointeeType);
349 
350   void mangleUnscopedTemplateName(const TemplateDecl *ND);
351   void
352   mangleTemplateInstantiationName(const TemplateDecl *TD,
353                                   const TemplateArgumentList &TemplateArgs);
354   void mangleObjCMethodName(const ObjCMethodDecl *MD);
355 
356   void mangleFunctionArgumentType(QualType T, SourceRange Range);
357   void manglePassObjectSizeArg(const PassObjectSizeAttr *POSA);
358 
359   bool isArtificialTagType(QualType T) const;
360 
361   // Declare manglers for every type class.
362 #define ABSTRACT_TYPE(CLASS, PARENT)
363 #define NON_CANONICAL_TYPE(CLASS, PARENT)
364 #define TYPE(CLASS, PARENT) void mangleType(const CLASS##Type *T, \
365                                             Qualifiers Quals, \
366                                             SourceRange Range);
367 #include "clang/AST/TypeNodes.inc"
368 #undef ABSTRACT_TYPE
369 #undef NON_CANONICAL_TYPE
370 #undef TYPE
371 
372   void mangleType(const TagDecl *TD);
373   void mangleDecayedArrayType(const ArrayType *T);
374   void mangleArrayType(const ArrayType *T);
375   void mangleFunctionClass(const FunctionDecl *FD);
376   void mangleCallingConvention(CallingConv CC);
377   void mangleCallingConvention(const FunctionType *T);
378   void mangleIntegerLiteral(const llvm::APSInt &Number, bool IsBoolean);
379   void mangleExpression(const Expr *E);
380   void mangleThrowSpecification(const FunctionProtoType *T);
381 
382   void mangleTemplateArgs(const TemplateDecl *TD,
383                           const TemplateArgumentList &TemplateArgs);
384   void mangleTemplateArg(const TemplateDecl *TD, const TemplateArgument &TA,
385                          const NamedDecl *Parm);
386 
387   void mangleObjCProtocol(const ObjCProtocolDecl *PD);
388   void mangleObjCLifetime(const QualType T, Qualifiers Quals,
389                           SourceRange Range);
390   void mangleObjCKindOfType(const ObjCObjectType *T, Qualifiers Quals,
391                             SourceRange Range);
392 };
393 }
394 
395 MicrosoftMangleContextImpl::MicrosoftMangleContextImpl(ASTContext &Context,
396                                                        DiagnosticsEngine &Diags)
397     : MicrosoftMangleContext(Context, Diags) {
398   // To mangle anonymous namespaces, hash the path to the main source file. The
399   // path should be whatever (probably relative) path was passed on the command
400   // line. The goal is for the compiler to produce the same output regardless of
401   // working directory, so use the uncanonicalized relative path.
402   //
403   // It's important to make the mangled names unique because, when CodeView
404   // debug info is in use, the debugger uses mangled type names to distinguish
405   // between otherwise identically named types in anonymous namespaces.
406   //
407   // These symbols are always internal, so there is no need for the hash to
408   // match what MSVC produces. For the same reason, clang is free to change the
409   // hash at any time without breaking compatibility with old versions of clang.
410   // The generated names are intended to look similar to what MSVC generates,
411   // which are something like "?A0x01234567@".
412   SourceManager &SM = Context.getSourceManager();
413   if (const FileEntry *FE = SM.getFileEntryForID(SM.getMainFileID())) {
414     // Truncate the hash so we get 8 characters of hexadecimal.
415     uint32_t TruncatedHash = uint32_t(xxHash64(FE->getName()));
416     AnonymousNamespaceHash = llvm::utohexstr(TruncatedHash);
417   } else {
418     // If we don't have a path to the main file, we'll just use 0.
419     AnonymousNamespaceHash = "0";
420   }
421 }
422 
423 bool MicrosoftMangleContextImpl::shouldMangleCXXName(const NamedDecl *D) {
424   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
425     LanguageLinkage L = FD->getLanguageLinkage();
426     // Overloadable functions need mangling.
427     if (FD->hasAttr<OverloadableAttr>())
428       return true;
429 
430     // The ABI expects that we would never mangle "typical" user-defined entry
431     // points regardless of visibility or freestanding-ness.
432     //
433     // N.B. This is distinct from asking about "main".  "main" has a lot of
434     // special rules associated with it in the standard while these
435     // user-defined entry points are outside of the purview of the standard.
436     // For example, there can be only one definition for "main" in a standards
437     // compliant program; however nothing forbids the existence of wmain and
438     // WinMain in the same translation unit.
439     if (FD->isMSVCRTEntryPoint())
440       return false;
441 
442     // C++ functions and those whose names are not a simple identifier need
443     // mangling.
444     if (!FD->getDeclName().isIdentifier() || L == CXXLanguageLinkage)
445       return true;
446 
447     // C functions are not mangled.
448     if (L == CLanguageLinkage)
449       return false;
450   }
451 
452   // Otherwise, no mangling is done outside C++ mode.
453   if (!getASTContext().getLangOpts().CPlusPlus)
454     return false;
455 
456   const VarDecl *VD = dyn_cast<VarDecl>(D);
457   if (VD && !isa<DecompositionDecl>(D)) {
458     // C variables are not mangled.
459     if (VD->isExternC())
460       return false;
461 
462     // Variables at global scope with non-internal linkage are not mangled.
463     const DeclContext *DC = getEffectiveDeclContext(D);
464     // Check for extern variable declared locally.
465     if (DC->isFunctionOrMethod() && D->hasLinkage())
466       while (!DC->isNamespace() && !DC->isTranslationUnit())
467         DC = getEffectiveParentContext(DC);
468 
469     if (DC->isTranslationUnit() && D->getFormalLinkage() == InternalLinkage &&
470         !isa<VarTemplateSpecializationDecl>(D) &&
471         D->getIdentifier() != nullptr)
472       return false;
473   }
474 
475   return true;
476 }
477 
478 bool
479 MicrosoftMangleContextImpl::shouldMangleStringLiteral(const StringLiteral *SL) {
480   return true;
481 }
482 
483 void MicrosoftCXXNameMangler::mangle(const NamedDecl *D, StringRef Prefix) {
484   // MSVC doesn't mangle C++ names the same way it mangles extern "C" names.
485   // Therefore it's really important that we don't decorate the
486   // name with leading underscores or leading/trailing at signs. So, by
487   // default, we emit an asm marker at the start so we get the name right.
488   // Callers can override this with a custom prefix.
489 
490   // <mangled-name> ::= ? <name> <type-encoding>
491   Out << Prefix;
492   mangleName(D);
493   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
494     mangleFunctionEncoding(FD, Context.shouldMangleDeclName(FD));
495   else if (const VarDecl *VD = dyn_cast<VarDecl>(D))
496     mangleVariableEncoding(VD);
497   else
498     llvm_unreachable("Tried to mangle unexpected NamedDecl!");
499 }
500 
501 void MicrosoftCXXNameMangler::mangleFunctionEncoding(const FunctionDecl *FD,
502                                                      bool ShouldMangle) {
503   // <type-encoding> ::= <function-class> <function-type>
504 
505   // Since MSVC operates on the type as written and not the canonical type, it
506   // actually matters which decl we have here.  MSVC appears to choose the
507   // first, since it is most likely to be the declaration in a header file.
508   FD = FD->getFirstDecl();
509 
510   // We should never ever see a FunctionNoProtoType at this point.
511   // We don't even know how to mangle their types anyway :).
512   const FunctionProtoType *FT = FD->getType()->castAs<FunctionProtoType>();
513 
514   // extern "C" functions can hold entities that must be mangled.
515   // As it stands, these functions still need to get expressed in the full
516   // external name.  They have their class and type omitted, replaced with '9'.
517   if (ShouldMangle) {
518     // We would like to mangle all extern "C" functions using this additional
519     // component but this would break compatibility with MSVC's behavior.
520     // Instead, do this when we know that compatibility isn't important (in
521     // other words, when it is an overloaded extern "C" function).
522     if (FD->isExternC() && FD->hasAttr<OverloadableAttr>())
523       Out << "$$J0";
524 
525     mangleFunctionClass(FD);
526 
527     mangleFunctionType(FT, FD, false, false);
528   } else {
529     Out << '9';
530   }
531 }
532 
533 void MicrosoftCXXNameMangler::mangleVariableEncoding(const VarDecl *VD) {
534   // <type-encoding> ::= <storage-class> <variable-type>
535   // <storage-class> ::= 0  # private static member
536   //                 ::= 1  # protected static member
537   //                 ::= 2  # public static member
538   //                 ::= 3  # global
539   //                 ::= 4  # static local
540 
541   // The first character in the encoding (after the name) is the storage class.
542   if (VD->isStaticDataMember()) {
543     // If it's a static member, it also encodes the access level.
544     switch (VD->getAccess()) {
545       default:
546       case AS_private: Out << '0'; break;
547       case AS_protected: Out << '1'; break;
548       case AS_public: Out << '2'; break;
549     }
550   }
551   else if (!VD->isStaticLocal())
552     Out << '3';
553   else
554     Out << '4';
555   // Now mangle the type.
556   // <variable-type> ::= <type> <cvr-qualifiers>
557   //                 ::= <type> <pointee-cvr-qualifiers> # pointers, references
558   // Pointers and references are odd. The type of 'int * const foo;' gets
559   // mangled as 'QAHA' instead of 'PAHB', for example.
560   SourceRange SR = VD->getSourceRange();
561   QualType Ty = VD->getType();
562   if (Ty->isPointerType() || Ty->isReferenceType() ||
563       Ty->isMemberPointerType()) {
564     mangleType(Ty, SR, QMM_Drop);
565     manglePointerExtQualifiers(
566         Ty.getDesugaredType(getASTContext()).getLocalQualifiers(), QualType());
567     if (const MemberPointerType *MPT = Ty->getAs<MemberPointerType>()) {
568       mangleQualifiers(MPT->getPointeeType().getQualifiers(), true);
569       // Member pointers are suffixed with a back reference to the member
570       // pointer's class name.
571       mangleName(MPT->getClass()->getAsCXXRecordDecl());
572     } else
573       mangleQualifiers(Ty->getPointeeType().getQualifiers(), false);
574   } else if (const ArrayType *AT = getASTContext().getAsArrayType(Ty)) {
575     // Global arrays are funny, too.
576     mangleDecayedArrayType(AT);
577     if (AT->getElementType()->isArrayType())
578       Out << 'A';
579     else
580       mangleQualifiers(Ty.getQualifiers(), false);
581   } else {
582     mangleType(Ty, SR, QMM_Drop);
583     mangleQualifiers(Ty.getQualifiers(), false);
584   }
585 }
586 
587 void MicrosoftCXXNameMangler::mangleMemberDataPointer(const CXXRecordDecl *RD,
588                                                       const ValueDecl *VD) {
589   // <member-data-pointer> ::= <integer-literal>
590   //                       ::= $F <number> <number>
591   //                       ::= $G <number> <number> <number>
592 
593   int64_t FieldOffset;
594   int64_t VBTableOffset;
595   MSInheritanceAttr::Spelling IM = RD->getMSInheritanceModel();
596   if (VD) {
597     FieldOffset = getASTContext().getFieldOffset(VD);
598     assert(FieldOffset % getASTContext().getCharWidth() == 0 &&
599            "cannot take address of bitfield");
600     FieldOffset /= getASTContext().getCharWidth();
601 
602     VBTableOffset = 0;
603 
604     if (IM == MSInheritanceAttr::Keyword_virtual_inheritance)
605       FieldOffset -= getASTContext().getOffsetOfBaseWithVBPtr(RD).getQuantity();
606   } else {
607     FieldOffset = RD->nullFieldOffsetIsZero() ? 0 : -1;
608 
609     VBTableOffset = -1;
610   }
611 
612   char Code = '\0';
613   switch (IM) {
614   case MSInheritanceAttr::Keyword_single_inheritance:      Code = '0'; break;
615   case MSInheritanceAttr::Keyword_multiple_inheritance:    Code = '0'; break;
616   case MSInheritanceAttr::Keyword_virtual_inheritance:     Code = 'F'; break;
617   case MSInheritanceAttr::Keyword_unspecified_inheritance: Code = 'G'; break;
618   case MSInheritanceAttr::SpellingNotCalculated:
619     llvm_unreachable("not reachable");
620   }
621 
622   Out << '$' << Code;
623 
624   mangleNumber(FieldOffset);
625 
626   // The C++ standard doesn't allow base-to-derived member pointer conversions
627   // in template parameter contexts, so the vbptr offset of data member pointers
628   // is always zero.
629   if (MSInheritanceAttr::hasVBPtrOffsetField(IM))
630     mangleNumber(0);
631   if (MSInheritanceAttr::hasVBTableOffsetField(IM))
632     mangleNumber(VBTableOffset);
633 }
634 
635 void
636 MicrosoftCXXNameMangler::mangleMemberFunctionPointer(const CXXRecordDecl *RD,
637                                                      const CXXMethodDecl *MD) {
638   // <member-function-pointer> ::= $1? <name>
639   //                           ::= $H? <name> <number>
640   //                           ::= $I? <name> <number> <number>
641   //                           ::= $J? <name> <number> <number> <number>
642 
643   MSInheritanceAttr::Spelling IM = RD->getMSInheritanceModel();
644 
645   char Code = '\0';
646   switch (IM) {
647   case MSInheritanceAttr::Keyword_single_inheritance:      Code = '1'; break;
648   case MSInheritanceAttr::Keyword_multiple_inheritance:    Code = 'H'; break;
649   case MSInheritanceAttr::Keyword_virtual_inheritance:     Code = 'I'; break;
650   case MSInheritanceAttr::Keyword_unspecified_inheritance: Code = 'J'; break;
651   case MSInheritanceAttr::SpellingNotCalculated:
652     llvm_unreachable("not reachable");
653   }
654 
655   // If non-virtual, mangle the name.  If virtual, mangle as a virtual memptr
656   // thunk.
657   uint64_t NVOffset = 0;
658   uint64_t VBTableOffset = 0;
659   uint64_t VBPtrOffset = 0;
660   if (MD) {
661     Out << '$' << Code << '?';
662     if (MD->isVirtual()) {
663       MicrosoftVTableContext *VTContext =
664           cast<MicrosoftVTableContext>(getASTContext().getVTableContext());
665       MethodVFTableLocation ML =
666           VTContext->getMethodVFTableLocation(GlobalDecl(MD));
667       mangleVirtualMemPtrThunk(MD, ML);
668       NVOffset = ML.VFPtrOffset.getQuantity();
669       VBTableOffset = ML.VBTableIndex * 4;
670       if (ML.VBase) {
671         const ASTRecordLayout &Layout = getASTContext().getASTRecordLayout(RD);
672         VBPtrOffset = Layout.getVBPtrOffset().getQuantity();
673       }
674     } else {
675       mangleName(MD);
676       mangleFunctionEncoding(MD, /*ShouldMangle=*/true);
677     }
678 
679     if (VBTableOffset == 0 &&
680         IM == MSInheritanceAttr::Keyword_virtual_inheritance)
681       NVOffset -= getASTContext().getOffsetOfBaseWithVBPtr(RD).getQuantity();
682   } else {
683     // Null single inheritance member functions are encoded as a simple nullptr.
684     if (IM == MSInheritanceAttr::Keyword_single_inheritance) {
685       Out << "$0A@";
686       return;
687     }
688     if (IM == MSInheritanceAttr::Keyword_unspecified_inheritance)
689       VBTableOffset = -1;
690     Out << '$' << Code;
691   }
692 
693   if (MSInheritanceAttr::hasNVOffsetField(/*IsMemberFunction=*/true, IM))
694     mangleNumber(static_cast<uint32_t>(NVOffset));
695   if (MSInheritanceAttr::hasVBPtrOffsetField(IM))
696     mangleNumber(VBPtrOffset);
697   if (MSInheritanceAttr::hasVBTableOffsetField(IM))
698     mangleNumber(VBTableOffset);
699 }
700 
701 void MicrosoftCXXNameMangler::mangleVirtualMemPtrThunk(
702     const CXXMethodDecl *MD, const MethodVFTableLocation &ML) {
703   // Get the vftable offset.
704   CharUnits PointerWidth = getASTContext().toCharUnitsFromBits(
705       getASTContext().getTargetInfo().getPointerWidth(0));
706   uint64_t OffsetInVFTable = ML.Index * PointerWidth.getQuantity();
707 
708   Out << "?_9";
709   mangleName(MD->getParent());
710   Out << "$B";
711   mangleNumber(OffsetInVFTable);
712   Out << 'A';
713   mangleCallingConvention(MD->getType()->getAs<FunctionProtoType>());
714 }
715 
716 void MicrosoftCXXNameMangler::mangleName(const NamedDecl *ND) {
717   // <name> ::= <unscoped-name> {[<named-scope>]+ | [<nested-name>]}? @
718 
719   // Always start with the unqualified name.
720   mangleUnqualifiedName(ND);
721 
722   mangleNestedName(ND);
723 
724   // Terminate the whole name with an '@'.
725   Out << '@';
726 }
727 
728 void MicrosoftCXXNameMangler::mangleNumber(int64_t Number) {
729   // <non-negative integer> ::= A@              # when Number == 0
730   //                        ::= <decimal digit> # when 1 <= Number <= 10
731   //                        ::= <hex digit>+ @  # when Number >= 10
732   //
733   // <number>               ::= [?] <non-negative integer>
734 
735   uint64_t Value = static_cast<uint64_t>(Number);
736   if (Number < 0) {
737     Value = -Value;
738     Out << '?';
739   }
740 
741   if (Value == 0)
742     Out << "A@";
743   else if (Value >= 1 && Value <= 10)
744     Out << (Value - 1);
745   else {
746     // Numbers that are not encoded as decimal digits are represented as nibbles
747     // in the range of ASCII characters 'A' to 'P'.
748     // The number 0x123450 would be encoded as 'BCDEFA'
749     char EncodedNumberBuffer[sizeof(uint64_t) * 2];
750     MutableArrayRef<char> BufferRef(EncodedNumberBuffer);
751     MutableArrayRef<char>::reverse_iterator I = BufferRef.rbegin();
752     for (; Value != 0; Value >>= 4)
753       *I++ = 'A' + (Value & 0xf);
754     Out.write(I.base(), I - BufferRef.rbegin());
755     Out << '@';
756   }
757 }
758 
759 static const TemplateDecl *
760 isTemplate(const NamedDecl *ND, const TemplateArgumentList *&TemplateArgs) {
761   // Check if we have a function template.
762   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
763     if (const TemplateDecl *TD = FD->getPrimaryTemplate()) {
764       TemplateArgs = FD->getTemplateSpecializationArgs();
765       return TD;
766     }
767   }
768 
769   // Check if we have a class template.
770   if (const ClassTemplateSpecializationDecl *Spec =
771           dyn_cast<ClassTemplateSpecializationDecl>(ND)) {
772     TemplateArgs = &Spec->getTemplateArgs();
773     return Spec->getSpecializedTemplate();
774   }
775 
776   // Check if we have a variable template.
777   if (const VarTemplateSpecializationDecl *Spec =
778           dyn_cast<VarTemplateSpecializationDecl>(ND)) {
779     TemplateArgs = &Spec->getTemplateArgs();
780     return Spec->getSpecializedTemplate();
781   }
782 
783   return nullptr;
784 }
785 
786 void MicrosoftCXXNameMangler::mangleUnqualifiedName(const NamedDecl *ND,
787                                                     DeclarationName Name) {
788   //  <unqualified-name> ::= <operator-name>
789   //                     ::= <ctor-dtor-name>
790   //                     ::= <source-name>
791   //                     ::= <template-name>
792 
793   // Check if we have a template.
794   const TemplateArgumentList *TemplateArgs = nullptr;
795   if (const TemplateDecl *TD = isTemplate(ND, TemplateArgs)) {
796     // Function templates aren't considered for name back referencing.  This
797     // makes sense since function templates aren't likely to occur multiple
798     // times in a symbol.
799     if (isa<FunctionTemplateDecl>(TD)) {
800       mangleTemplateInstantiationName(TD, *TemplateArgs);
801       Out << '@';
802       return;
803     }
804 
805     // Here comes the tricky thing: if we need to mangle something like
806     //   void foo(A::X<Y>, B::X<Y>),
807     // the X<Y> part is aliased. However, if you need to mangle
808     //   void foo(A::X<A::Y>, A::X<B::Y>),
809     // the A::X<> part is not aliased.
810     // That is, from the mangler's perspective we have a structure like this:
811     //   namespace[s] -> type[ -> template-parameters]
812     // but from the Clang perspective we have
813     //   type [ -> template-parameters]
814     //      \-> namespace[s]
815     // What we do is we create a new mangler, mangle the same type (without
816     // a namespace suffix) to a string using the extra mangler and then use
817     // the mangled type name as a key to check the mangling of different types
818     // for aliasing.
819 
820     // It's important to key cache reads off ND, not TD -- the same TD can
821     // be used with different TemplateArgs, but ND uniquely identifies
822     // TD / TemplateArg pairs.
823     ArgBackRefMap::iterator Found = TemplateArgBackReferences.find(ND);
824     if (Found == TemplateArgBackReferences.end()) {
825 
826       TemplateArgStringMap::iterator Found = TemplateArgStrings.find(ND);
827       if (Found == TemplateArgStrings.end()) {
828         // Mangle full template name into temporary buffer.
829         llvm::SmallString<64> TemplateMangling;
830         llvm::raw_svector_ostream Stream(TemplateMangling);
831         MicrosoftCXXNameMangler Extra(Context, Stream);
832         Extra.mangleTemplateInstantiationName(TD, *TemplateArgs);
833 
834         // Use the string backref vector to possibly get a back reference.
835         mangleSourceName(TemplateMangling);
836 
837         // Memoize back reference for this type if one exist, else memoize
838         // the mangling itself.
839         BackRefVec::iterator StringFound =
840             llvm::find(NameBackReferences, TemplateMangling);
841         if (StringFound != NameBackReferences.end()) {
842           TemplateArgBackReferences[ND] =
843               StringFound - NameBackReferences.begin();
844         } else {
845           TemplateArgStrings[ND] =
846               TemplateArgStringStorage.save(TemplateMangling.str());
847         }
848       } else {
849         Out << Found->second << '@'; // Outputs a StringRef.
850       }
851     } else {
852       Out << Found->second; // Outputs a back reference (an int).
853     }
854     return;
855   }
856 
857   switch (Name.getNameKind()) {
858     case DeclarationName::Identifier: {
859       if (const IdentifierInfo *II = Name.getAsIdentifierInfo()) {
860         mangleSourceName(II->getName());
861         break;
862       }
863 
864       // Otherwise, an anonymous entity.  We must have a declaration.
865       assert(ND && "mangling empty name without declaration");
866 
867       if (const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(ND)) {
868         if (NS->isAnonymousNamespace()) {
869           Out << "?A0x" << Context.getAnonymousNamespaceHash() << '@';
870           break;
871         }
872       }
873 
874       if (const DecompositionDecl *DD = dyn_cast<DecompositionDecl>(ND)) {
875         // Decomposition declarations are considered anonymous, and get
876         // numbered with a $S prefix.
877         llvm::SmallString<64> Name("$S");
878         // Get a unique id for the anonymous struct.
879         Name += llvm::utostr(Context.getAnonymousStructId(DD) + 1);
880         mangleSourceName(Name);
881         break;
882       }
883 
884       if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
885         // We must have an anonymous union or struct declaration.
886         const CXXRecordDecl *RD = VD->getType()->getAsCXXRecordDecl();
887         assert(RD && "expected variable decl to have a record type");
888         // Anonymous types with no tag or typedef get the name of their
889         // declarator mangled in.  If they have no declarator, number them with
890         // a $S prefix.
891         llvm::SmallString<64> Name("$S");
892         // Get a unique id for the anonymous struct.
893         Name += llvm::utostr(Context.getAnonymousStructId(RD) + 1);
894         mangleSourceName(Name.str());
895         break;
896       }
897 
898       // We must have an anonymous struct.
899       const TagDecl *TD = cast<TagDecl>(ND);
900       if (const TypedefNameDecl *D = TD->getTypedefNameForAnonDecl()) {
901         assert(TD->getDeclContext() == D->getDeclContext() &&
902                "Typedef should not be in another decl context!");
903         assert(D->getDeclName().getAsIdentifierInfo() &&
904                "Typedef was not named!");
905         mangleSourceName(D->getDeclName().getAsIdentifierInfo()->getName());
906         break;
907       }
908 
909       if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(TD)) {
910         if (Record->isLambda()) {
911           llvm::SmallString<10> Name("<lambda_");
912 
913           Decl *LambdaContextDecl = Record->getLambdaContextDecl();
914           unsigned LambdaManglingNumber = Record->getLambdaManglingNumber();
915           unsigned LambdaId;
916           const ParmVarDecl *Parm =
917               dyn_cast_or_null<ParmVarDecl>(LambdaContextDecl);
918           const FunctionDecl *Func =
919               Parm ? dyn_cast<FunctionDecl>(Parm->getDeclContext()) : nullptr;
920 
921           if (Func) {
922             unsigned DefaultArgNo =
923                 Func->getNumParams() - Parm->getFunctionScopeIndex();
924             Name += llvm::utostr(DefaultArgNo);
925             Name += "_";
926           }
927 
928           if (LambdaManglingNumber)
929             LambdaId = LambdaManglingNumber;
930           else
931             LambdaId = Context.getLambdaId(Record);
932 
933           Name += llvm::utostr(LambdaId);
934           Name += ">";
935 
936           mangleSourceName(Name);
937 
938           // If the context of a closure type is an initializer for a class
939           // member (static or nonstatic), it is encoded in a qualified name.
940           if (LambdaManglingNumber && LambdaContextDecl) {
941             if ((isa<VarDecl>(LambdaContextDecl) ||
942                  isa<FieldDecl>(LambdaContextDecl)) &&
943                 LambdaContextDecl->getDeclContext()->isRecord()) {
944               mangleUnqualifiedName(cast<NamedDecl>(LambdaContextDecl));
945             }
946           }
947           break;
948         }
949       }
950 
951       llvm::SmallString<64> Name;
952       if (DeclaratorDecl *DD =
953               Context.getASTContext().getDeclaratorForUnnamedTagDecl(TD)) {
954         // Anonymous types without a name for linkage purposes have their
955         // declarator mangled in if they have one.
956         Name += "<unnamed-type-";
957         Name += DD->getName();
958       } else if (TypedefNameDecl *TND =
959                      Context.getASTContext().getTypedefNameForUnnamedTagDecl(
960                          TD)) {
961         // Anonymous types without a name for linkage purposes have their
962         // associate typedef mangled in if they have one.
963         Name += "<unnamed-type-";
964         Name += TND->getName();
965       } else if (isa<EnumDecl>(TD) &&
966                  cast<EnumDecl>(TD)->enumerator_begin() !=
967                      cast<EnumDecl>(TD)->enumerator_end()) {
968         // Anonymous non-empty enums mangle in the first enumerator.
969         auto *ED = cast<EnumDecl>(TD);
970         Name += "<unnamed-enum-";
971         Name += ED->enumerator_begin()->getName();
972       } else {
973         // Otherwise, number the types using a $S prefix.
974         Name += "<unnamed-type-$S";
975         Name += llvm::utostr(Context.getAnonymousStructId(TD) + 1);
976       }
977       Name += ">";
978       mangleSourceName(Name.str());
979       break;
980     }
981 
982     case DeclarationName::ObjCZeroArgSelector:
983     case DeclarationName::ObjCOneArgSelector:
984     case DeclarationName::ObjCMultiArgSelector: {
985       // This is reachable only when constructing an outlined SEH finally
986       // block.  Nothing depends on this mangling and it's used only with
987       // functinos with internal linkage.
988       llvm::SmallString<64> Name;
989       mangleSourceName(Name.str());
990       break;
991     }
992 
993     case DeclarationName::CXXConstructorName:
994       if (isStructorDecl(ND)) {
995         if (StructorType == Ctor_CopyingClosure) {
996           Out << "?_O";
997           return;
998         }
999         if (StructorType == Ctor_DefaultClosure) {
1000           Out << "?_F";
1001           return;
1002         }
1003       }
1004       Out << "?0";
1005       return;
1006 
1007     case DeclarationName::CXXDestructorName:
1008       if (isStructorDecl(ND))
1009         // If the named decl is the C++ destructor we're mangling,
1010         // use the type we were given.
1011         mangleCXXDtorType(static_cast<CXXDtorType>(StructorType));
1012       else
1013         // Otherwise, use the base destructor name. This is relevant if a
1014         // class with a destructor is declared within a destructor.
1015         mangleCXXDtorType(Dtor_Base);
1016       break;
1017 
1018     case DeclarationName::CXXConversionFunctionName:
1019       // <operator-name> ::= ?B # (cast)
1020       // The target type is encoded as the return type.
1021       Out << "?B";
1022       break;
1023 
1024     case DeclarationName::CXXOperatorName:
1025       mangleOperatorName(Name.getCXXOverloadedOperator(), ND->getLocation());
1026       break;
1027 
1028     case DeclarationName::CXXLiteralOperatorName: {
1029       Out << "?__K";
1030       mangleSourceName(Name.getCXXLiteralIdentifier()->getName());
1031       break;
1032     }
1033 
1034     case DeclarationName::CXXDeductionGuideName:
1035       llvm_unreachable("Can't mangle a deduction guide name!");
1036 
1037     case DeclarationName::CXXUsingDirective:
1038       llvm_unreachable("Can't mangle a using directive name!");
1039   }
1040 }
1041 
1042 // <postfix> ::= <unqualified-name> [<postfix>]
1043 //           ::= <substitution> [<postfix>]
1044 void MicrosoftCXXNameMangler::mangleNestedName(const NamedDecl *ND) {
1045   const DeclContext *DC = getEffectiveDeclContext(ND);
1046   while (!DC->isTranslationUnit()) {
1047     if (isa<TagDecl>(ND) || isa<VarDecl>(ND)) {
1048       unsigned Disc;
1049       if (Context.getNextDiscriminator(ND, Disc)) {
1050         Out << '?';
1051         mangleNumber(Disc);
1052         Out << '?';
1053       }
1054     }
1055 
1056     if (const BlockDecl *BD = dyn_cast<BlockDecl>(DC)) {
1057       auto Discriminate =
1058           [](StringRef Name, const unsigned Discriminator,
1059              const unsigned ParameterDiscriminator) -> std::string {
1060         std::string Buffer;
1061         llvm::raw_string_ostream Stream(Buffer);
1062         Stream << Name;
1063         if (Discriminator)
1064           Stream << '_' << Discriminator;
1065         if (ParameterDiscriminator)
1066           Stream << '_' << ParameterDiscriminator;
1067         return Stream.str();
1068       };
1069 
1070       unsigned Discriminator = BD->getBlockManglingNumber();
1071       if (!Discriminator)
1072         Discriminator = Context.getBlockId(BD, /*Local=*/false);
1073 
1074       // Mangle the parameter position as a discriminator to deal with unnamed
1075       // parameters.  Rather than mangling the unqualified parameter name,
1076       // always use the position to give a uniform mangling.
1077       unsigned ParameterDiscriminator = 0;
1078       if (const auto *MC = BD->getBlockManglingContextDecl())
1079         if (const auto *P = dyn_cast<ParmVarDecl>(MC))
1080           if (const auto *F = dyn_cast<FunctionDecl>(P->getDeclContext()))
1081             ParameterDiscriminator =
1082                 F->getNumParams() - P->getFunctionScopeIndex();
1083 
1084       DC = getEffectiveDeclContext(BD);
1085 
1086       Out << '?';
1087       mangleSourceName(Discriminate("_block_invoke", Discriminator,
1088                                     ParameterDiscriminator));
1089       // If we have a block mangling context, encode that now.  This allows us
1090       // to discriminate between named static data initializers in the same
1091       // scope.  This is handled differently from parameters, which use
1092       // positions to discriminate between multiple instances.
1093       if (const auto *MC = BD->getBlockManglingContextDecl())
1094         if (!isa<ParmVarDecl>(MC))
1095           if (const auto *ND = dyn_cast<NamedDecl>(MC))
1096             mangleUnqualifiedName(ND);
1097       // MS ABI and Itanium manglings are in inverted scopes.  In the case of a
1098       // RecordDecl, mangle the entire scope hierarchy at this point rather than
1099       // just the unqualified name to get the ordering correct.
1100       if (const auto *RD = dyn_cast<RecordDecl>(DC))
1101         mangleName(RD);
1102       else
1103         Out << '@';
1104       // void __cdecl
1105       Out << "YAX";
1106       // struct __block_literal *
1107       Out << 'P';
1108       // __ptr64
1109       if (PointersAre64Bit)
1110         Out << 'E';
1111       Out << 'A';
1112       mangleArtificialTagType(TTK_Struct,
1113                              Discriminate("__block_literal", Discriminator,
1114                                           ParameterDiscriminator));
1115       Out << "@Z";
1116 
1117       // If the effective context was a Record, we have fully mangled the
1118       // qualified name and do not need to continue.
1119       if (isa<RecordDecl>(DC))
1120         break;
1121       continue;
1122     } else if (const ObjCMethodDecl *Method = dyn_cast<ObjCMethodDecl>(DC)) {
1123       mangleObjCMethodName(Method);
1124     } else if (isa<NamedDecl>(DC)) {
1125       ND = cast<NamedDecl>(DC);
1126       if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
1127         mangle(FD, "?");
1128         break;
1129       } else {
1130         mangleUnqualifiedName(ND);
1131         // Lambdas in default arguments conceptually belong to the function the
1132         // parameter corresponds to.
1133         if (const auto *LDADC = getLambdaDefaultArgumentDeclContext(ND)) {
1134           DC = LDADC;
1135           continue;
1136         }
1137       }
1138     }
1139     DC = DC->getParent();
1140   }
1141 }
1142 
1143 void MicrosoftCXXNameMangler::mangleCXXDtorType(CXXDtorType T) {
1144   // Microsoft uses the names on the case labels for these dtor variants.  Clang
1145   // uses the Itanium terminology internally.  Everything in this ABI delegates
1146   // towards the base dtor.
1147   switch (T) {
1148   // <operator-name> ::= ?1  # destructor
1149   case Dtor_Base: Out << "?1"; return;
1150   // <operator-name> ::= ?_D # vbase destructor
1151   case Dtor_Complete: Out << "?_D"; return;
1152   // <operator-name> ::= ?_G # scalar deleting destructor
1153   case Dtor_Deleting: Out << "?_G"; return;
1154   // <operator-name> ::= ?_E # vector deleting destructor
1155   // FIXME: Add a vector deleting dtor type.  It goes in the vtable, so we need
1156   // it.
1157   case Dtor_Comdat:
1158     llvm_unreachable("not expecting a COMDAT");
1159   }
1160   llvm_unreachable("Unsupported dtor type?");
1161 }
1162 
1163 void MicrosoftCXXNameMangler::mangleOperatorName(OverloadedOperatorKind OO,
1164                                                  SourceLocation Loc) {
1165   switch (OO) {
1166   //                     ?0 # constructor
1167   //                     ?1 # destructor
1168   // <operator-name> ::= ?2 # new
1169   case OO_New: Out << "?2"; break;
1170   // <operator-name> ::= ?3 # delete
1171   case OO_Delete: Out << "?3"; break;
1172   // <operator-name> ::= ?4 # =
1173   case OO_Equal: Out << "?4"; break;
1174   // <operator-name> ::= ?5 # >>
1175   case OO_GreaterGreater: Out << "?5"; break;
1176   // <operator-name> ::= ?6 # <<
1177   case OO_LessLess: Out << "?6"; break;
1178   // <operator-name> ::= ?7 # !
1179   case OO_Exclaim: Out << "?7"; break;
1180   // <operator-name> ::= ?8 # ==
1181   case OO_EqualEqual: Out << "?8"; break;
1182   // <operator-name> ::= ?9 # !=
1183   case OO_ExclaimEqual: Out << "?9"; break;
1184   // <operator-name> ::= ?A # []
1185   case OO_Subscript: Out << "?A"; break;
1186   //                     ?B # conversion
1187   // <operator-name> ::= ?C # ->
1188   case OO_Arrow: Out << "?C"; break;
1189   // <operator-name> ::= ?D # *
1190   case OO_Star: Out << "?D"; break;
1191   // <operator-name> ::= ?E # ++
1192   case OO_PlusPlus: Out << "?E"; break;
1193   // <operator-name> ::= ?F # --
1194   case OO_MinusMinus: Out << "?F"; break;
1195   // <operator-name> ::= ?G # -
1196   case OO_Minus: Out << "?G"; break;
1197   // <operator-name> ::= ?H # +
1198   case OO_Plus: Out << "?H"; break;
1199   // <operator-name> ::= ?I # &
1200   case OO_Amp: Out << "?I"; break;
1201   // <operator-name> ::= ?J # ->*
1202   case OO_ArrowStar: Out << "?J"; break;
1203   // <operator-name> ::= ?K # /
1204   case OO_Slash: Out << "?K"; break;
1205   // <operator-name> ::= ?L # %
1206   case OO_Percent: Out << "?L"; break;
1207   // <operator-name> ::= ?M # <
1208   case OO_Less: Out << "?M"; break;
1209   // <operator-name> ::= ?N # <=
1210   case OO_LessEqual: Out << "?N"; break;
1211   // <operator-name> ::= ?O # >
1212   case OO_Greater: Out << "?O"; break;
1213   // <operator-name> ::= ?P # >=
1214   case OO_GreaterEqual: Out << "?P"; break;
1215   // <operator-name> ::= ?Q # ,
1216   case OO_Comma: Out << "?Q"; break;
1217   // <operator-name> ::= ?R # ()
1218   case OO_Call: Out << "?R"; break;
1219   // <operator-name> ::= ?S # ~
1220   case OO_Tilde: Out << "?S"; break;
1221   // <operator-name> ::= ?T # ^
1222   case OO_Caret: Out << "?T"; break;
1223   // <operator-name> ::= ?U # |
1224   case OO_Pipe: Out << "?U"; break;
1225   // <operator-name> ::= ?V # &&
1226   case OO_AmpAmp: Out << "?V"; break;
1227   // <operator-name> ::= ?W # ||
1228   case OO_PipePipe: Out << "?W"; break;
1229   // <operator-name> ::= ?X # *=
1230   case OO_StarEqual: Out << "?X"; break;
1231   // <operator-name> ::= ?Y # +=
1232   case OO_PlusEqual: Out << "?Y"; break;
1233   // <operator-name> ::= ?Z # -=
1234   case OO_MinusEqual: Out << "?Z"; break;
1235   // <operator-name> ::= ?_0 # /=
1236   case OO_SlashEqual: Out << "?_0"; break;
1237   // <operator-name> ::= ?_1 # %=
1238   case OO_PercentEqual: Out << "?_1"; break;
1239   // <operator-name> ::= ?_2 # >>=
1240   case OO_GreaterGreaterEqual: Out << "?_2"; break;
1241   // <operator-name> ::= ?_3 # <<=
1242   case OO_LessLessEqual: Out << "?_3"; break;
1243   // <operator-name> ::= ?_4 # &=
1244   case OO_AmpEqual: Out << "?_4"; break;
1245   // <operator-name> ::= ?_5 # |=
1246   case OO_PipeEqual: Out << "?_5"; break;
1247   // <operator-name> ::= ?_6 # ^=
1248   case OO_CaretEqual: Out << "?_6"; break;
1249   //                     ?_7 # vftable
1250   //                     ?_8 # vbtable
1251   //                     ?_9 # vcall
1252   //                     ?_A # typeof
1253   //                     ?_B # local static guard
1254   //                     ?_C # string
1255   //                     ?_D # vbase destructor
1256   //                     ?_E # vector deleting destructor
1257   //                     ?_F # default constructor closure
1258   //                     ?_G # scalar deleting destructor
1259   //                     ?_H # vector constructor iterator
1260   //                     ?_I # vector destructor iterator
1261   //                     ?_J # vector vbase constructor iterator
1262   //                     ?_K # virtual displacement map
1263   //                     ?_L # eh vector constructor iterator
1264   //                     ?_M # eh vector destructor iterator
1265   //                     ?_N # eh vector vbase constructor iterator
1266   //                     ?_O # copy constructor closure
1267   //                     ?_P<name> # udt returning <name>
1268   //                     ?_Q # <unknown>
1269   //                     ?_R0 # RTTI Type Descriptor
1270   //                     ?_R1 # RTTI Base Class Descriptor at (a,b,c,d)
1271   //                     ?_R2 # RTTI Base Class Array
1272   //                     ?_R3 # RTTI Class Hierarchy Descriptor
1273   //                     ?_R4 # RTTI Complete Object Locator
1274   //                     ?_S # local vftable
1275   //                     ?_T # local vftable constructor closure
1276   // <operator-name> ::= ?_U # new[]
1277   case OO_Array_New: Out << "?_U"; break;
1278   // <operator-name> ::= ?_V # delete[]
1279   case OO_Array_Delete: Out << "?_V"; break;
1280   // <operator-name> ::= ?__L # co_await
1281   case OO_Coawait: Out << "?__L"; break;
1282   // <operator-name> ::= ?__M # <=>
1283   case OO_Spaceship: Out << "?__M"; break;
1284 
1285   case OO_Conditional: {
1286     DiagnosticsEngine &Diags = Context.getDiags();
1287     unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
1288       "cannot mangle this conditional operator yet");
1289     Diags.Report(Loc, DiagID);
1290     break;
1291   }
1292 
1293   case OO_None:
1294   case NUM_OVERLOADED_OPERATORS:
1295     llvm_unreachable("Not an overloaded operator");
1296   }
1297 }
1298 
1299 void MicrosoftCXXNameMangler::mangleSourceName(StringRef Name) {
1300   // <source name> ::= <identifier> @
1301   BackRefVec::iterator Found = llvm::find(NameBackReferences, Name);
1302   if (Found == NameBackReferences.end()) {
1303     if (NameBackReferences.size() < 10)
1304       NameBackReferences.push_back(Name);
1305     Out << Name << '@';
1306   } else {
1307     Out << (Found - NameBackReferences.begin());
1308   }
1309 }
1310 
1311 void MicrosoftCXXNameMangler::mangleObjCMethodName(const ObjCMethodDecl *MD) {
1312   Context.mangleObjCMethodName(MD, Out);
1313 }
1314 
1315 void MicrosoftCXXNameMangler::mangleTemplateInstantiationName(
1316     const TemplateDecl *TD, const TemplateArgumentList &TemplateArgs) {
1317   // <template-name> ::= <unscoped-template-name> <template-args>
1318   //                 ::= <substitution>
1319   // Always start with the unqualified name.
1320 
1321   // Templates have their own context for back references.
1322   ArgBackRefMap OuterFunArgsContext;
1323   ArgBackRefMap OuterTemplateArgsContext;
1324   BackRefVec OuterTemplateContext;
1325   PassObjectSizeArgsSet OuterPassObjectSizeArgs;
1326   NameBackReferences.swap(OuterTemplateContext);
1327   FunArgBackReferences.swap(OuterFunArgsContext);
1328   TemplateArgBackReferences.swap(OuterTemplateArgsContext);
1329   PassObjectSizeArgs.swap(OuterPassObjectSizeArgs);
1330 
1331   mangleUnscopedTemplateName(TD);
1332   mangleTemplateArgs(TD, TemplateArgs);
1333 
1334   // Restore the previous back reference contexts.
1335   NameBackReferences.swap(OuterTemplateContext);
1336   FunArgBackReferences.swap(OuterFunArgsContext);
1337   TemplateArgBackReferences.swap(OuterTemplateArgsContext);
1338   PassObjectSizeArgs.swap(OuterPassObjectSizeArgs);
1339 }
1340 
1341 void
1342 MicrosoftCXXNameMangler::mangleUnscopedTemplateName(const TemplateDecl *TD) {
1343   // <unscoped-template-name> ::= ?$ <unqualified-name>
1344   Out << "?$";
1345   mangleUnqualifiedName(TD);
1346 }
1347 
1348 void MicrosoftCXXNameMangler::mangleIntegerLiteral(const llvm::APSInt &Value,
1349                                                    bool IsBoolean) {
1350   // <integer-literal> ::= $0 <number>
1351   Out << "$0";
1352   // Make sure booleans are encoded as 0/1.
1353   if (IsBoolean && Value.getBoolValue())
1354     mangleNumber(1);
1355   else if (Value.isSigned())
1356     mangleNumber(Value.getSExtValue());
1357   else
1358     mangleNumber(Value.getZExtValue());
1359 }
1360 
1361 void MicrosoftCXXNameMangler::mangleExpression(const Expr *E) {
1362   // See if this is a constant expression.
1363   llvm::APSInt Value;
1364   if (E->isIntegerConstantExpr(Value, Context.getASTContext())) {
1365     mangleIntegerLiteral(Value, E->getType()->isBooleanType());
1366     return;
1367   }
1368 
1369   // Look through no-op casts like template parameter substitutions.
1370   E = E->IgnoreParenNoopCasts(Context.getASTContext());
1371 
1372   const CXXUuidofExpr *UE = nullptr;
1373   if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) {
1374     if (UO->getOpcode() == UO_AddrOf)
1375       UE = dyn_cast<CXXUuidofExpr>(UO->getSubExpr());
1376   } else
1377     UE = dyn_cast<CXXUuidofExpr>(E);
1378 
1379   if (UE) {
1380     // If we had to peek through an address-of operator, treat this like we are
1381     // dealing with a pointer type.  Otherwise, treat it like a const reference.
1382     //
1383     // N.B. This matches up with the handling of TemplateArgument::Declaration
1384     // in mangleTemplateArg
1385     if (UE == E)
1386       Out << "$E?";
1387     else
1388       Out << "$1?";
1389 
1390     // This CXXUuidofExpr is mangled as-if it were actually a VarDecl from
1391     // const __s_GUID _GUID_{lower case UUID with underscores}
1392     StringRef Uuid = UE->getUuidStr();
1393     std::string Name = "_GUID_" + Uuid.lower();
1394     std::replace(Name.begin(), Name.end(), '-', '_');
1395 
1396     mangleSourceName(Name);
1397     // Terminate the whole name with an '@'.
1398     Out << '@';
1399     // It's a global variable.
1400     Out << '3';
1401     // It's a struct called __s_GUID.
1402     mangleArtificialTagType(TTK_Struct, "__s_GUID");
1403     // It's const.
1404     Out << 'B';
1405     return;
1406   }
1407 
1408   // As bad as this diagnostic is, it's better than crashing.
1409   DiagnosticsEngine &Diags = Context.getDiags();
1410   unsigned DiagID = Diags.getCustomDiagID(
1411       DiagnosticsEngine::Error, "cannot yet mangle expression type %0");
1412   Diags.Report(E->getExprLoc(), DiagID) << E->getStmtClassName()
1413                                         << E->getSourceRange();
1414 }
1415 
1416 void MicrosoftCXXNameMangler::mangleTemplateArgs(
1417     const TemplateDecl *TD, const TemplateArgumentList &TemplateArgs) {
1418   // <template-args> ::= <template-arg>+
1419   const TemplateParameterList *TPL = TD->getTemplateParameters();
1420   assert(TPL->size() == TemplateArgs.size() &&
1421          "size mismatch between args and parms!");
1422 
1423   for (size_t i = 0; i < TemplateArgs.size(); ++i) {
1424     const TemplateArgument &TA = TemplateArgs[i];
1425 
1426     // Separate consecutive packs by $$Z.
1427     if (i > 0 && TA.getKind() == TemplateArgument::Pack &&
1428         TemplateArgs[i - 1].getKind() == TemplateArgument::Pack)
1429       Out << "$$Z";
1430 
1431     mangleTemplateArg(TD, TA, TPL->getParam(i));
1432   }
1433 }
1434 
1435 void MicrosoftCXXNameMangler::mangleTemplateArg(const TemplateDecl *TD,
1436                                                 const TemplateArgument &TA,
1437                                                 const NamedDecl *Parm) {
1438   // <template-arg> ::= <type>
1439   //                ::= <integer-literal>
1440   //                ::= <member-data-pointer>
1441   //                ::= <member-function-pointer>
1442   //                ::= $E? <name> <type-encoding>
1443   //                ::= $1? <name> <type-encoding>
1444   //                ::= $0A@
1445   //                ::= <template-args>
1446 
1447   switch (TA.getKind()) {
1448   case TemplateArgument::Null:
1449     llvm_unreachable("Can't mangle null template arguments!");
1450   case TemplateArgument::TemplateExpansion:
1451     llvm_unreachable("Can't mangle template expansion arguments!");
1452   case TemplateArgument::Type: {
1453     QualType T = TA.getAsType();
1454     mangleType(T, SourceRange(), QMM_Escape);
1455     break;
1456   }
1457   case TemplateArgument::Declaration: {
1458     const NamedDecl *ND = TA.getAsDecl();
1459     if (isa<FieldDecl>(ND) || isa<IndirectFieldDecl>(ND)) {
1460       mangleMemberDataPointer(cast<CXXRecordDecl>(ND->getDeclContext())
1461                                   ->getMostRecentNonInjectedDecl(),
1462                               cast<ValueDecl>(ND));
1463     } else if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
1464       const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD);
1465       if (MD && MD->isInstance()) {
1466         mangleMemberFunctionPointer(
1467             MD->getParent()->getMostRecentNonInjectedDecl(), MD);
1468       } else {
1469         Out << "$1?";
1470         mangleName(FD);
1471         mangleFunctionEncoding(FD, /*ShouldMangle=*/true);
1472       }
1473     } else {
1474       mangle(ND, TA.getParamTypeForDecl()->isReferenceType() ? "$E?" : "$1?");
1475     }
1476     break;
1477   }
1478   case TemplateArgument::Integral:
1479     mangleIntegerLiteral(TA.getAsIntegral(),
1480                          TA.getIntegralType()->isBooleanType());
1481     break;
1482   case TemplateArgument::NullPtr: {
1483     QualType T = TA.getNullPtrType();
1484     if (const MemberPointerType *MPT = T->getAs<MemberPointerType>()) {
1485       const CXXRecordDecl *RD = MPT->getMostRecentCXXRecordDecl();
1486       if (MPT->isMemberFunctionPointerType() &&
1487           !isa<FunctionTemplateDecl>(TD)) {
1488         mangleMemberFunctionPointer(RD, nullptr);
1489         return;
1490       }
1491       if (MPT->isMemberDataPointer()) {
1492         if (!isa<FunctionTemplateDecl>(TD)) {
1493           mangleMemberDataPointer(RD, nullptr);
1494           return;
1495         }
1496         // nullptr data pointers are always represented with a single field
1497         // which is initialized with either 0 or -1.  Why -1?  Well, we need to
1498         // distinguish the case where the data member is at offset zero in the
1499         // record.
1500         // However, we are free to use 0 *if* we would use multiple fields for
1501         // non-nullptr member pointers.
1502         if (!RD->nullFieldOffsetIsZero()) {
1503           mangleIntegerLiteral(llvm::APSInt::get(-1), /*IsBoolean=*/false);
1504           return;
1505         }
1506       }
1507     }
1508     mangleIntegerLiteral(llvm::APSInt::getUnsigned(0), /*IsBoolean=*/false);
1509     break;
1510   }
1511   case TemplateArgument::Expression:
1512     mangleExpression(TA.getAsExpr());
1513     break;
1514   case TemplateArgument::Pack: {
1515     ArrayRef<TemplateArgument> TemplateArgs = TA.getPackAsArray();
1516     if (TemplateArgs.empty()) {
1517       if (isa<TemplateTypeParmDecl>(Parm) ||
1518           isa<TemplateTemplateParmDecl>(Parm))
1519         // MSVC 2015 changed the mangling for empty expanded template packs,
1520         // use the old mangling for link compatibility for old versions.
1521         Out << (Context.getASTContext().getLangOpts().isCompatibleWithMSVC(
1522                     LangOptions::MSVC2015)
1523                     ? "$$V"
1524                     : "$$$V");
1525       else if (isa<NonTypeTemplateParmDecl>(Parm))
1526         Out << "$S";
1527       else
1528         llvm_unreachable("unexpected template parameter decl!");
1529     } else {
1530       for (const TemplateArgument &PA : TemplateArgs)
1531         mangleTemplateArg(TD, PA, Parm);
1532     }
1533     break;
1534   }
1535   case TemplateArgument::Template: {
1536     const NamedDecl *ND =
1537         TA.getAsTemplate().getAsTemplateDecl()->getTemplatedDecl();
1538     if (const auto *TD = dyn_cast<TagDecl>(ND)) {
1539       mangleType(TD);
1540     } else if (isa<TypeAliasDecl>(ND)) {
1541       Out << "$$Y";
1542       mangleName(ND);
1543     } else {
1544       llvm_unreachable("unexpected template template NamedDecl!");
1545     }
1546     break;
1547   }
1548   }
1549 }
1550 
1551 void MicrosoftCXXNameMangler::mangleObjCProtocol(const ObjCProtocolDecl *PD) {
1552   llvm::SmallString<64> TemplateMangling;
1553   llvm::raw_svector_ostream Stream(TemplateMangling);
1554   MicrosoftCXXNameMangler Extra(Context, Stream);
1555 
1556   Stream << "?$";
1557   Extra.mangleSourceName("Protocol");
1558   Extra.mangleArtificialTagType(TTK_Struct, PD->getName());
1559 
1560   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__ObjC"});
1561 }
1562 
1563 void MicrosoftCXXNameMangler::mangleObjCLifetime(const QualType Type,
1564                                                  Qualifiers Quals,
1565                                                  SourceRange Range) {
1566   llvm::SmallString<64> TemplateMangling;
1567   llvm::raw_svector_ostream Stream(TemplateMangling);
1568   MicrosoftCXXNameMangler Extra(Context, Stream);
1569 
1570   Stream << "?$";
1571   switch (Quals.getObjCLifetime()) {
1572   case Qualifiers::OCL_None:
1573   case Qualifiers::OCL_ExplicitNone:
1574     break;
1575   case Qualifiers::OCL_Autoreleasing:
1576     Extra.mangleSourceName("Autoreleasing");
1577     break;
1578   case Qualifiers::OCL_Strong:
1579     Extra.mangleSourceName("Strong");
1580     break;
1581   case Qualifiers::OCL_Weak:
1582     Extra.mangleSourceName("Weak");
1583     break;
1584   }
1585   Extra.manglePointerCVQualifiers(Quals);
1586   Extra.manglePointerExtQualifiers(Quals, Type);
1587   Extra.mangleType(Type, Range);
1588 
1589   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__ObjC"});
1590 }
1591 
1592 void MicrosoftCXXNameMangler::mangleObjCKindOfType(const ObjCObjectType *T,
1593                                                    Qualifiers Quals,
1594                                                    SourceRange Range) {
1595   llvm::SmallString<64> TemplateMangling;
1596   llvm::raw_svector_ostream Stream(TemplateMangling);
1597   MicrosoftCXXNameMangler Extra(Context, Stream);
1598 
1599   Stream << "?$";
1600   Extra.mangleSourceName("KindOf");
1601   Extra.mangleType(QualType(T, 0)
1602                        .stripObjCKindOfType(getASTContext())
1603                        ->getAs<ObjCObjectType>(),
1604                    Quals, Range);
1605 
1606   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__ObjC"});
1607 }
1608 
1609 void MicrosoftCXXNameMangler::mangleQualifiers(Qualifiers Quals,
1610                                                bool IsMember) {
1611   // <cvr-qualifiers> ::= [E] [F] [I] <base-cvr-qualifiers>
1612   // 'E' means __ptr64 (32-bit only); 'F' means __unaligned (32/64-bit only);
1613   // 'I' means __restrict (32/64-bit).
1614   // Note that the MSVC __restrict keyword isn't the same as the C99 restrict
1615   // keyword!
1616   // <base-cvr-qualifiers> ::= A  # near
1617   //                       ::= B  # near const
1618   //                       ::= C  # near volatile
1619   //                       ::= D  # near const volatile
1620   //                       ::= E  # far (16-bit)
1621   //                       ::= F  # far const (16-bit)
1622   //                       ::= G  # far volatile (16-bit)
1623   //                       ::= H  # far const volatile (16-bit)
1624   //                       ::= I  # huge (16-bit)
1625   //                       ::= J  # huge const (16-bit)
1626   //                       ::= K  # huge volatile (16-bit)
1627   //                       ::= L  # huge const volatile (16-bit)
1628   //                       ::= M <basis> # based
1629   //                       ::= N <basis> # based const
1630   //                       ::= O <basis> # based volatile
1631   //                       ::= P <basis> # based const volatile
1632   //                       ::= Q  # near member
1633   //                       ::= R  # near const member
1634   //                       ::= S  # near volatile member
1635   //                       ::= T  # near const volatile member
1636   //                       ::= U  # far member (16-bit)
1637   //                       ::= V  # far const member (16-bit)
1638   //                       ::= W  # far volatile member (16-bit)
1639   //                       ::= X  # far const volatile member (16-bit)
1640   //                       ::= Y  # huge member (16-bit)
1641   //                       ::= Z  # huge const member (16-bit)
1642   //                       ::= 0  # huge volatile member (16-bit)
1643   //                       ::= 1  # huge const volatile member (16-bit)
1644   //                       ::= 2 <basis> # based member
1645   //                       ::= 3 <basis> # based const member
1646   //                       ::= 4 <basis> # based volatile member
1647   //                       ::= 5 <basis> # based const volatile member
1648   //                       ::= 6  # near function (pointers only)
1649   //                       ::= 7  # far function (pointers only)
1650   //                       ::= 8  # near method (pointers only)
1651   //                       ::= 9  # far method (pointers only)
1652   //                       ::= _A <basis> # based function (pointers only)
1653   //                       ::= _B <basis> # based function (far?) (pointers only)
1654   //                       ::= _C <basis> # based method (pointers only)
1655   //                       ::= _D <basis> # based method (far?) (pointers only)
1656   //                       ::= _E # block (Clang)
1657   // <basis> ::= 0 # __based(void)
1658   //         ::= 1 # __based(segment)?
1659   //         ::= 2 <name> # __based(name)
1660   //         ::= 3 # ?
1661   //         ::= 4 # ?
1662   //         ::= 5 # not really based
1663   bool HasConst = Quals.hasConst(),
1664        HasVolatile = Quals.hasVolatile();
1665 
1666   if (!IsMember) {
1667     if (HasConst && HasVolatile) {
1668       Out << 'D';
1669     } else if (HasVolatile) {
1670       Out << 'C';
1671     } else if (HasConst) {
1672       Out << 'B';
1673     } else {
1674       Out << 'A';
1675     }
1676   } else {
1677     if (HasConst && HasVolatile) {
1678       Out << 'T';
1679     } else if (HasVolatile) {
1680       Out << 'S';
1681     } else if (HasConst) {
1682       Out << 'R';
1683     } else {
1684       Out << 'Q';
1685     }
1686   }
1687 
1688   // FIXME: For now, just drop all extension qualifiers on the floor.
1689 }
1690 
1691 void
1692 MicrosoftCXXNameMangler::mangleRefQualifier(RefQualifierKind RefQualifier) {
1693   // <ref-qualifier> ::= G                # lvalue reference
1694   //                 ::= H                # rvalue-reference
1695   switch (RefQualifier) {
1696   case RQ_None:
1697     break;
1698 
1699   case RQ_LValue:
1700     Out << 'G';
1701     break;
1702 
1703   case RQ_RValue:
1704     Out << 'H';
1705     break;
1706   }
1707 }
1708 
1709 void MicrosoftCXXNameMangler::manglePointerExtQualifiers(Qualifiers Quals,
1710                                                          QualType PointeeType) {
1711   if (PointersAre64Bit &&
1712       (PointeeType.isNull() || !PointeeType->isFunctionType()))
1713     Out << 'E';
1714 
1715   if (Quals.hasRestrict())
1716     Out << 'I';
1717 
1718   if (Quals.hasUnaligned() ||
1719       (!PointeeType.isNull() && PointeeType.getLocalQualifiers().hasUnaligned()))
1720     Out << 'F';
1721 }
1722 
1723 void MicrosoftCXXNameMangler::manglePointerCVQualifiers(Qualifiers Quals) {
1724   // <pointer-cv-qualifiers> ::= P  # no qualifiers
1725   //                         ::= Q  # const
1726   //                         ::= R  # volatile
1727   //                         ::= S  # const volatile
1728   bool HasConst = Quals.hasConst(),
1729        HasVolatile = Quals.hasVolatile();
1730 
1731   if (HasConst && HasVolatile) {
1732     Out << 'S';
1733   } else if (HasVolatile) {
1734     Out << 'R';
1735   } else if (HasConst) {
1736     Out << 'Q';
1737   } else {
1738     Out << 'P';
1739   }
1740 }
1741 
1742 void MicrosoftCXXNameMangler::mangleFunctionArgumentType(QualType T,
1743                                                          SourceRange Range) {
1744   // MSVC will backreference two canonically equivalent types that have slightly
1745   // different manglings when mangled alone.
1746 
1747   // Decayed types do not match up with non-decayed versions of the same type.
1748   //
1749   // e.g.
1750   // void (*x)(void) will not form a backreference with void x(void)
1751   void *TypePtr;
1752   if (const auto *DT = T->getAs<DecayedType>()) {
1753     QualType OriginalType = DT->getOriginalType();
1754     // All decayed ArrayTypes should be treated identically; as-if they were
1755     // a decayed IncompleteArrayType.
1756     if (const auto *AT = getASTContext().getAsArrayType(OriginalType))
1757       OriginalType = getASTContext().getIncompleteArrayType(
1758           AT->getElementType(), AT->getSizeModifier(),
1759           AT->getIndexTypeCVRQualifiers());
1760 
1761     TypePtr = OriginalType.getCanonicalType().getAsOpaquePtr();
1762     // If the original parameter was textually written as an array,
1763     // instead treat the decayed parameter like it's const.
1764     //
1765     // e.g.
1766     // int [] -> int * const
1767     if (OriginalType->isArrayType())
1768       T = T.withConst();
1769   } else {
1770     TypePtr = T.getCanonicalType().getAsOpaquePtr();
1771   }
1772 
1773   ArgBackRefMap::iterator Found = FunArgBackReferences.find(TypePtr);
1774 
1775   if (Found == FunArgBackReferences.end()) {
1776     size_t OutSizeBefore = Out.tell();
1777 
1778     mangleType(T, Range, QMM_Drop);
1779 
1780     // See if it's worth creating a back reference.
1781     // Only types longer than 1 character are considered
1782     // and only 10 back references slots are available:
1783     bool LongerThanOneChar = (Out.tell() - OutSizeBefore > 1);
1784     if (LongerThanOneChar && FunArgBackReferences.size() < 10) {
1785       size_t Size = FunArgBackReferences.size();
1786       FunArgBackReferences[TypePtr] = Size;
1787     }
1788   } else {
1789     Out << Found->second;
1790   }
1791 }
1792 
1793 void MicrosoftCXXNameMangler::manglePassObjectSizeArg(
1794     const PassObjectSizeAttr *POSA) {
1795   int Type = POSA->getType();
1796   bool Dynamic = POSA->isDynamic();
1797 
1798   auto Iter = PassObjectSizeArgs.insert({Type, Dynamic}).first;
1799   auto *TypePtr = (const void *)&*Iter;
1800   ArgBackRefMap::iterator Found = FunArgBackReferences.find(TypePtr);
1801 
1802   if (Found == FunArgBackReferences.end()) {
1803     std::string Name =
1804         Dynamic ? "__pass_dynamic_object_size" : "__pass_object_size";
1805     mangleArtificialTagType(TTK_Enum, Name + llvm::utostr(Type), {"__clang"});
1806 
1807     if (FunArgBackReferences.size() < 10) {
1808       size_t Size = FunArgBackReferences.size();
1809       FunArgBackReferences[TypePtr] = Size;
1810     }
1811   } else {
1812     Out << Found->second;
1813   }
1814 }
1815 
1816 void MicrosoftCXXNameMangler::mangleAddressSpaceType(QualType T,
1817                                                      Qualifiers Quals,
1818                                                      SourceRange Range) {
1819   // Address space is mangled as an unqualified templated type in the __clang
1820   // namespace. The demangled version of this is:
1821   // In the case of a language specific address space:
1822   // __clang::struct _AS[language_addr_space]<Type>
1823   // where:
1824   //  <language_addr_space> ::= <OpenCL-addrspace> | <CUDA-addrspace>
1825   //    <OpenCL-addrspace> ::= "CL" [ "global" | "local" | "constant" |
1826   //                                "private"| "generic" ]
1827   //    <CUDA-addrspace> ::= "CU" [ "device" | "constant" | "shared" ]
1828   //    Note that the above were chosen to match the Itanium mangling for this.
1829   //
1830   // In the case of a non-language specific address space:
1831   //  __clang::struct _AS<TargetAS, Type>
1832   assert(Quals.hasAddressSpace() && "Not valid without address space");
1833   llvm::SmallString<32> ASMangling;
1834   llvm::raw_svector_ostream Stream(ASMangling);
1835   MicrosoftCXXNameMangler Extra(Context, Stream);
1836   Stream << "?$";
1837 
1838   LangAS AS = Quals.getAddressSpace();
1839   if (Context.getASTContext().addressSpaceMapManglingFor(AS)) {
1840     unsigned TargetAS = Context.getASTContext().getTargetAddressSpace(AS);
1841     Extra.mangleSourceName("_AS");
1842     Extra.mangleIntegerLiteral(llvm::APSInt::getUnsigned(TargetAS),
1843                                /*IsBoolean*/ false);
1844   } else {
1845     switch (AS) {
1846     default:
1847       llvm_unreachable("Not a language specific address space");
1848     case LangAS::opencl_global:
1849       Extra.mangleSourceName("_ASCLglobal");
1850       break;
1851     case LangAS::opencl_local:
1852       Extra.mangleSourceName("_ASCLlocal");
1853       break;
1854     case LangAS::opencl_constant:
1855       Extra.mangleSourceName("_ASCLconstant");
1856       break;
1857     case LangAS::opencl_private:
1858       Extra.mangleSourceName("_ASCLprivate");
1859       break;
1860     case LangAS::opencl_generic:
1861       Extra.mangleSourceName("_ASCLgeneric");
1862       break;
1863     case LangAS::cuda_device:
1864       Extra.mangleSourceName("_ASCUdevice");
1865       break;
1866     case LangAS::cuda_constant:
1867       Extra.mangleSourceName("_ASCUconstant");
1868       break;
1869     case LangAS::cuda_shared:
1870       Extra.mangleSourceName("_ASCUshared");
1871       break;
1872     }
1873   }
1874 
1875   Extra.mangleType(T, Range, QMM_Escape);
1876   mangleQualifiers(Qualifiers(), false);
1877   mangleArtificialTagType(TTK_Struct, ASMangling, {"__clang"});
1878 }
1879 
1880 void MicrosoftCXXNameMangler::mangleType(QualType T, SourceRange Range,
1881                                          QualifierMangleMode QMM) {
1882   // Don't use the canonical types.  MSVC includes things like 'const' on
1883   // pointer arguments to function pointers that canonicalization strips away.
1884   T = T.getDesugaredType(getASTContext());
1885   Qualifiers Quals = T.getLocalQualifiers();
1886 
1887   if (const ArrayType *AT = getASTContext().getAsArrayType(T)) {
1888     // If there were any Quals, getAsArrayType() pushed them onto the array
1889     // element type.
1890     if (QMM == QMM_Mangle)
1891       Out << 'A';
1892     else if (QMM == QMM_Escape || QMM == QMM_Result)
1893       Out << "$$B";
1894     mangleArrayType(AT);
1895     return;
1896   }
1897 
1898   bool IsPointer = T->isAnyPointerType() || T->isMemberPointerType() ||
1899                    T->isReferenceType() || T->isBlockPointerType();
1900 
1901   switch (QMM) {
1902   case QMM_Drop:
1903     if (Quals.hasObjCLifetime())
1904       Quals = Quals.withoutObjCLifetime();
1905     break;
1906   case QMM_Mangle:
1907     if (const FunctionType *FT = dyn_cast<FunctionType>(T)) {
1908       Out << '6';
1909       mangleFunctionType(FT);
1910       return;
1911     }
1912     mangleQualifiers(Quals, false);
1913     break;
1914   case QMM_Escape:
1915     if (!IsPointer && Quals) {
1916       Out << "$$C";
1917       mangleQualifiers(Quals, false);
1918     }
1919     break;
1920   case QMM_Result:
1921     // Presence of __unaligned qualifier shouldn't affect mangling here.
1922     Quals.removeUnaligned();
1923     if (Quals.hasObjCLifetime())
1924       Quals = Quals.withoutObjCLifetime();
1925     if ((!IsPointer && Quals) || isa<TagType>(T) || isArtificialTagType(T)) {
1926       Out << '?';
1927       mangleQualifiers(Quals, false);
1928     }
1929     break;
1930   }
1931 
1932   const Type *ty = T.getTypePtr();
1933 
1934   switch (ty->getTypeClass()) {
1935 #define ABSTRACT_TYPE(CLASS, PARENT)
1936 #define NON_CANONICAL_TYPE(CLASS, PARENT) \
1937   case Type::CLASS: \
1938     llvm_unreachable("can't mangle non-canonical type " #CLASS "Type"); \
1939     return;
1940 #define TYPE(CLASS, PARENT) \
1941   case Type::CLASS: \
1942     mangleType(cast<CLASS##Type>(ty), Quals, Range); \
1943     break;
1944 #include "clang/AST/TypeNodes.inc"
1945 #undef ABSTRACT_TYPE
1946 #undef NON_CANONICAL_TYPE
1947 #undef TYPE
1948   }
1949 }
1950 
1951 void MicrosoftCXXNameMangler::mangleType(const BuiltinType *T, Qualifiers,
1952                                          SourceRange Range) {
1953   //  <type>         ::= <builtin-type>
1954   //  <builtin-type> ::= X  # void
1955   //                 ::= C  # signed char
1956   //                 ::= D  # char
1957   //                 ::= E  # unsigned char
1958   //                 ::= F  # short
1959   //                 ::= G  # unsigned short (or wchar_t if it's not a builtin)
1960   //                 ::= H  # int
1961   //                 ::= I  # unsigned int
1962   //                 ::= J  # long
1963   //                 ::= K  # unsigned long
1964   //                     L  # <none>
1965   //                 ::= M  # float
1966   //                 ::= N  # double
1967   //                 ::= O  # long double (__float80 is mangled differently)
1968   //                 ::= _J # long long, __int64
1969   //                 ::= _K # unsigned long long, __int64
1970   //                 ::= _L # __int128
1971   //                 ::= _M # unsigned __int128
1972   //                 ::= _N # bool
1973   //                     _O # <array in parameter>
1974   //                 ::= _Q # char8_t
1975   //                 ::= _S # char16_t
1976   //                 ::= _T # __float80 (Intel)
1977   //                 ::= _U # char32_t
1978   //                 ::= _W # wchar_t
1979   //                 ::= _Z # __float80 (Digital Mars)
1980   switch (T->getKind()) {
1981   case BuiltinType::Void:
1982     Out << 'X';
1983     break;
1984   case BuiltinType::SChar:
1985     Out << 'C';
1986     break;
1987   case BuiltinType::Char_U:
1988   case BuiltinType::Char_S:
1989     Out << 'D';
1990     break;
1991   case BuiltinType::UChar:
1992     Out << 'E';
1993     break;
1994   case BuiltinType::Short:
1995     Out << 'F';
1996     break;
1997   case BuiltinType::UShort:
1998     Out << 'G';
1999     break;
2000   case BuiltinType::Int:
2001     Out << 'H';
2002     break;
2003   case BuiltinType::UInt:
2004     Out << 'I';
2005     break;
2006   case BuiltinType::Long:
2007     Out << 'J';
2008     break;
2009   case BuiltinType::ULong:
2010     Out << 'K';
2011     break;
2012   case BuiltinType::Float:
2013     Out << 'M';
2014     break;
2015   case BuiltinType::Double:
2016     Out << 'N';
2017     break;
2018   // TODO: Determine size and mangle accordingly
2019   case BuiltinType::LongDouble:
2020     Out << 'O';
2021     break;
2022   case BuiltinType::LongLong:
2023     Out << "_J";
2024     break;
2025   case BuiltinType::ULongLong:
2026     Out << "_K";
2027     break;
2028   case BuiltinType::Int128:
2029     Out << "_L";
2030     break;
2031   case BuiltinType::UInt128:
2032     Out << "_M";
2033     break;
2034   case BuiltinType::Bool:
2035     Out << "_N";
2036     break;
2037   case BuiltinType::Char8:
2038     Out << "_Q";
2039     break;
2040   case BuiltinType::Char16:
2041     Out << "_S";
2042     break;
2043   case BuiltinType::Char32:
2044     Out << "_U";
2045     break;
2046   case BuiltinType::WChar_S:
2047   case BuiltinType::WChar_U:
2048     Out << "_W";
2049     break;
2050 
2051 #define BUILTIN_TYPE(Id, SingletonId)
2052 #define PLACEHOLDER_TYPE(Id, SingletonId) \
2053   case BuiltinType::Id:
2054 #include "clang/AST/BuiltinTypes.def"
2055   case BuiltinType::Dependent:
2056     llvm_unreachable("placeholder types shouldn't get to name mangling");
2057 
2058   case BuiltinType::ObjCId:
2059     mangleArtificialTagType(TTK_Struct, "objc_object");
2060     break;
2061   case BuiltinType::ObjCClass:
2062     mangleArtificialTagType(TTK_Struct, "objc_class");
2063     break;
2064   case BuiltinType::ObjCSel:
2065     mangleArtificialTagType(TTK_Struct, "objc_selector");
2066     break;
2067 
2068 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
2069   case BuiltinType::Id: \
2070     Out << "PAUocl_" #ImgType "_" #Suffix "@@"; \
2071     break;
2072 #include "clang/Basic/OpenCLImageTypes.def"
2073   case BuiltinType::OCLSampler:
2074     Out << "PA";
2075     mangleArtificialTagType(TTK_Struct, "ocl_sampler");
2076     break;
2077   case BuiltinType::OCLEvent:
2078     Out << "PA";
2079     mangleArtificialTagType(TTK_Struct, "ocl_event");
2080     break;
2081   case BuiltinType::OCLClkEvent:
2082     Out << "PA";
2083     mangleArtificialTagType(TTK_Struct, "ocl_clkevent");
2084     break;
2085   case BuiltinType::OCLQueue:
2086     Out << "PA";
2087     mangleArtificialTagType(TTK_Struct, "ocl_queue");
2088     break;
2089   case BuiltinType::OCLReserveID:
2090     Out << "PA";
2091     mangleArtificialTagType(TTK_Struct, "ocl_reserveid");
2092     break;
2093 #define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
2094   case BuiltinType::Id: \
2095     mangleArtificialTagType(TTK_Struct, "ocl_" #ExtType); \
2096     break;
2097 #include "clang/Basic/OpenCLExtensionTypes.def"
2098 
2099   case BuiltinType::NullPtr:
2100     Out << "$$T";
2101     break;
2102 
2103   case BuiltinType::Float16:
2104     mangleArtificialTagType(TTK_Struct, "_Float16", {"__clang"});
2105     break;
2106 
2107   case BuiltinType::Half:
2108     mangleArtificialTagType(TTK_Struct, "_Half", {"__clang"});
2109     break;
2110 
2111 #define SVE_TYPE(Name, Id, SingletonId) \
2112   case BuiltinType::Id:
2113 #include "clang/Basic/AArch64SVEACLETypes.def"
2114   case BuiltinType::ShortAccum:
2115   case BuiltinType::Accum:
2116   case BuiltinType::LongAccum:
2117   case BuiltinType::UShortAccum:
2118   case BuiltinType::UAccum:
2119   case BuiltinType::ULongAccum:
2120   case BuiltinType::ShortFract:
2121   case BuiltinType::Fract:
2122   case BuiltinType::LongFract:
2123   case BuiltinType::UShortFract:
2124   case BuiltinType::UFract:
2125   case BuiltinType::ULongFract:
2126   case BuiltinType::SatShortAccum:
2127   case BuiltinType::SatAccum:
2128   case BuiltinType::SatLongAccum:
2129   case BuiltinType::SatUShortAccum:
2130   case BuiltinType::SatUAccum:
2131   case BuiltinType::SatULongAccum:
2132   case BuiltinType::SatShortFract:
2133   case BuiltinType::SatFract:
2134   case BuiltinType::SatLongFract:
2135   case BuiltinType::SatUShortFract:
2136   case BuiltinType::SatUFract:
2137   case BuiltinType::SatULongFract:
2138   case BuiltinType::Float128: {
2139     DiagnosticsEngine &Diags = Context.getDiags();
2140     unsigned DiagID = Diags.getCustomDiagID(
2141         DiagnosticsEngine::Error, "cannot mangle this built-in %0 type yet");
2142     Diags.Report(Range.getBegin(), DiagID)
2143         << T->getName(Context.getASTContext().getPrintingPolicy()) << Range;
2144     break;
2145   }
2146   }
2147 }
2148 
2149 // <type>          ::= <function-type>
2150 void MicrosoftCXXNameMangler::mangleType(const FunctionProtoType *T, Qualifiers,
2151                                          SourceRange) {
2152   // Structors only appear in decls, so at this point we know it's not a
2153   // structor type.
2154   // FIXME: This may not be lambda-friendly.
2155   if (T->getMethodQuals() || T->getRefQualifier() != RQ_None) {
2156     Out << "$$A8@@";
2157     mangleFunctionType(T, /*D=*/nullptr, /*ForceThisQuals=*/true);
2158   } else {
2159     Out << "$$A6";
2160     mangleFunctionType(T);
2161   }
2162 }
2163 void MicrosoftCXXNameMangler::mangleType(const FunctionNoProtoType *T,
2164                                          Qualifiers, SourceRange) {
2165   Out << "$$A6";
2166   mangleFunctionType(T);
2167 }
2168 
2169 void MicrosoftCXXNameMangler::mangleFunctionType(const FunctionType *T,
2170                                                  const FunctionDecl *D,
2171                                                  bool ForceThisQuals,
2172                                                  bool MangleExceptionSpec) {
2173   // <function-type> ::= <this-cvr-qualifiers> <calling-convention>
2174   //                     <return-type> <argument-list> <throw-spec>
2175   const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(T);
2176 
2177   SourceRange Range;
2178   if (D) Range = D->getSourceRange();
2179 
2180   bool IsInLambda = false;
2181   bool IsStructor = false, HasThisQuals = ForceThisQuals, IsCtorClosure = false;
2182   CallingConv CC = T->getCallConv();
2183   if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(D)) {
2184     if (MD->getParent()->isLambda())
2185       IsInLambda = true;
2186     if (MD->isInstance())
2187       HasThisQuals = true;
2188     if (isa<CXXDestructorDecl>(MD)) {
2189       IsStructor = true;
2190     } else if (isa<CXXConstructorDecl>(MD)) {
2191       IsStructor = true;
2192       IsCtorClosure = (StructorType == Ctor_CopyingClosure ||
2193                        StructorType == Ctor_DefaultClosure) &&
2194                       isStructorDecl(MD);
2195       if (IsCtorClosure)
2196         CC = getASTContext().getDefaultCallingConvention(
2197             /*IsVariadic=*/false, /*IsCXXMethod=*/true);
2198     }
2199   }
2200 
2201   // If this is a C++ instance method, mangle the CVR qualifiers for the
2202   // this pointer.
2203   if (HasThisQuals) {
2204     Qualifiers Quals = Proto->getMethodQuals();
2205     manglePointerExtQualifiers(Quals, /*PointeeType=*/QualType());
2206     mangleRefQualifier(Proto->getRefQualifier());
2207     mangleQualifiers(Quals, /*IsMember=*/false);
2208   }
2209 
2210   mangleCallingConvention(CC);
2211 
2212   // <return-type> ::= <type>
2213   //               ::= @ # structors (they have no declared return type)
2214   if (IsStructor) {
2215     if (isa<CXXDestructorDecl>(D) && isStructorDecl(D)) {
2216       // The scalar deleting destructor takes an extra int argument which is not
2217       // reflected in the AST.
2218       if (StructorType == Dtor_Deleting) {
2219         Out << (PointersAre64Bit ? "PEAXI@Z" : "PAXI@Z");
2220         return;
2221       }
2222       // The vbase destructor returns void which is not reflected in the AST.
2223       if (StructorType == Dtor_Complete) {
2224         Out << "XXZ";
2225         return;
2226       }
2227     }
2228     if (IsCtorClosure) {
2229       // Default constructor closure and copy constructor closure both return
2230       // void.
2231       Out << 'X';
2232 
2233       if (StructorType == Ctor_DefaultClosure) {
2234         // Default constructor closure always has no arguments.
2235         Out << 'X';
2236       } else if (StructorType == Ctor_CopyingClosure) {
2237         // Copy constructor closure always takes an unqualified reference.
2238         mangleFunctionArgumentType(getASTContext().getLValueReferenceType(
2239                                        Proto->getParamType(0)
2240                                            ->getAs<LValueReferenceType>()
2241                                            ->getPointeeType(),
2242                                        /*SpelledAsLValue=*/true),
2243                                    Range);
2244         Out << '@';
2245       } else {
2246         llvm_unreachable("unexpected constructor closure!");
2247       }
2248       Out << 'Z';
2249       return;
2250     }
2251     Out << '@';
2252   } else {
2253     QualType ResultType = T->getReturnType();
2254     if (const auto *AT =
2255             dyn_cast_or_null<AutoType>(ResultType->getContainedAutoType())) {
2256       Out << '?';
2257       mangleQualifiers(ResultType.getLocalQualifiers(), /*IsMember=*/false);
2258       Out << '?';
2259       assert(AT->getKeyword() != AutoTypeKeyword::GNUAutoType &&
2260              "shouldn't need to mangle __auto_type!");
2261       mangleSourceName(AT->isDecltypeAuto() ? "<decltype-auto>" : "<auto>");
2262       Out << '@';
2263     } else if (IsInLambda) {
2264       Out << '@';
2265     } else {
2266       if (ResultType->isVoidType())
2267         ResultType = ResultType.getUnqualifiedType();
2268       mangleType(ResultType, Range, QMM_Result);
2269     }
2270   }
2271 
2272   // <argument-list> ::= X # void
2273   //                 ::= <type>+ @
2274   //                 ::= <type>* Z # varargs
2275   if (!Proto) {
2276     // Function types without prototypes can arise when mangling a function type
2277     // within an overloadable function in C. We mangle these as the absence of
2278     // any parameter types (not even an empty parameter list).
2279     Out << '@';
2280   } else if (Proto->getNumParams() == 0 && !Proto->isVariadic()) {
2281     Out << 'X';
2282   } else {
2283     // Happens for function pointer type arguments for example.
2284     for (unsigned I = 0, E = Proto->getNumParams(); I != E; ++I) {
2285       mangleFunctionArgumentType(Proto->getParamType(I), Range);
2286       // Mangle each pass_object_size parameter as if it's a parameter of enum
2287       // type passed directly after the parameter with the pass_object_size
2288       // attribute. The aforementioned enum's name is __pass_object_size, and we
2289       // pretend it resides in a top-level namespace called __clang.
2290       //
2291       // FIXME: Is there a defined extension notation for the MS ABI, or is it
2292       // necessary to just cross our fingers and hope this type+namespace
2293       // combination doesn't conflict with anything?
2294       if (D)
2295         if (const auto *P = D->getParamDecl(I)->getAttr<PassObjectSizeAttr>())
2296           manglePassObjectSizeArg(P);
2297     }
2298     // <builtin-type>      ::= Z  # ellipsis
2299     if (Proto->isVariadic())
2300       Out << 'Z';
2301     else
2302       Out << '@';
2303   }
2304 
2305   if (MangleExceptionSpec && getASTContext().getLangOpts().CPlusPlus17 &&
2306       getASTContext().getLangOpts().isCompatibleWithMSVC(
2307           LangOptions::MSVC2017_5))
2308     mangleThrowSpecification(Proto);
2309   else
2310     Out << 'Z';
2311 }
2312 
2313 void MicrosoftCXXNameMangler::mangleFunctionClass(const FunctionDecl *FD) {
2314   // <function-class>  ::= <member-function> E? # E designates a 64-bit 'this'
2315   //                                            # pointer. in 64-bit mode *all*
2316   //                                            # 'this' pointers are 64-bit.
2317   //                   ::= <global-function>
2318   // <member-function> ::= A # private: near
2319   //                   ::= B # private: far
2320   //                   ::= C # private: static near
2321   //                   ::= D # private: static far
2322   //                   ::= E # private: virtual near
2323   //                   ::= F # private: virtual far
2324   //                   ::= I # protected: near
2325   //                   ::= J # protected: far
2326   //                   ::= K # protected: static near
2327   //                   ::= L # protected: static far
2328   //                   ::= M # protected: virtual near
2329   //                   ::= N # protected: virtual far
2330   //                   ::= Q # public: near
2331   //                   ::= R # public: far
2332   //                   ::= S # public: static near
2333   //                   ::= T # public: static far
2334   //                   ::= U # public: virtual near
2335   //                   ::= V # public: virtual far
2336   // <global-function> ::= Y # global near
2337   //                   ::= Z # global far
2338   if (const CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(FD)) {
2339     bool IsVirtual = MD->isVirtual();
2340     // When mangling vbase destructor variants, ignore whether or not the
2341     // underlying destructor was defined to be virtual.
2342     if (isa<CXXDestructorDecl>(MD) && isStructorDecl(MD) &&
2343         StructorType == Dtor_Complete) {
2344       IsVirtual = false;
2345     }
2346     switch (MD->getAccess()) {
2347       case AS_none:
2348         llvm_unreachable("Unsupported access specifier");
2349       case AS_private:
2350         if (MD->isStatic())
2351           Out << 'C';
2352         else if (IsVirtual)
2353           Out << 'E';
2354         else
2355           Out << 'A';
2356         break;
2357       case AS_protected:
2358         if (MD->isStatic())
2359           Out << 'K';
2360         else if (IsVirtual)
2361           Out << 'M';
2362         else
2363           Out << 'I';
2364         break;
2365       case AS_public:
2366         if (MD->isStatic())
2367           Out << 'S';
2368         else if (IsVirtual)
2369           Out << 'U';
2370         else
2371           Out << 'Q';
2372     }
2373   } else {
2374     Out << 'Y';
2375   }
2376 }
2377 void MicrosoftCXXNameMangler::mangleCallingConvention(CallingConv CC) {
2378   // <calling-convention> ::= A # __cdecl
2379   //                      ::= B # __export __cdecl
2380   //                      ::= C # __pascal
2381   //                      ::= D # __export __pascal
2382   //                      ::= E # __thiscall
2383   //                      ::= F # __export __thiscall
2384   //                      ::= G # __stdcall
2385   //                      ::= H # __export __stdcall
2386   //                      ::= I # __fastcall
2387   //                      ::= J # __export __fastcall
2388   //                      ::= Q # __vectorcall
2389   //                      ::= w # __regcall
2390   // The 'export' calling conventions are from a bygone era
2391   // (*cough*Win16*cough*) when functions were declared for export with
2392   // that keyword. (It didn't actually export them, it just made them so
2393   // that they could be in a DLL and somebody from another module could call
2394   // them.)
2395 
2396   switch (CC) {
2397     default:
2398       llvm_unreachable("Unsupported CC for mangling");
2399     case CC_Win64:
2400     case CC_X86_64SysV:
2401     case CC_C: Out << 'A'; break;
2402     case CC_X86Pascal: Out << 'C'; break;
2403     case CC_X86ThisCall: Out << 'E'; break;
2404     case CC_X86StdCall: Out << 'G'; break;
2405     case CC_X86FastCall: Out << 'I'; break;
2406     case CC_X86VectorCall: Out << 'Q'; break;
2407     case CC_Swift: Out << 'S'; break;
2408     case CC_PreserveMost: Out << 'U'; break;
2409     case CC_X86RegCall: Out << 'w'; break;
2410   }
2411 }
2412 void MicrosoftCXXNameMangler::mangleCallingConvention(const FunctionType *T) {
2413   mangleCallingConvention(T->getCallConv());
2414 }
2415 
2416 void MicrosoftCXXNameMangler::mangleThrowSpecification(
2417                                                 const FunctionProtoType *FT) {
2418   // <throw-spec> ::= Z # (default)
2419   //              ::= _E # noexcept
2420   if (FT->canThrow())
2421     Out << 'Z';
2422   else
2423     Out << "_E";
2424 }
2425 
2426 void MicrosoftCXXNameMangler::mangleType(const UnresolvedUsingType *T,
2427                                          Qualifiers, SourceRange Range) {
2428   // Probably should be mangled as a template instantiation; need to see what
2429   // VC does first.
2430   DiagnosticsEngine &Diags = Context.getDiags();
2431   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2432     "cannot mangle this unresolved dependent type yet");
2433   Diags.Report(Range.getBegin(), DiagID)
2434     << Range;
2435 }
2436 
2437 // <type>        ::= <union-type> | <struct-type> | <class-type> | <enum-type>
2438 // <union-type>  ::= T <name>
2439 // <struct-type> ::= U <name>
2440 // <class-type>  ::= V <name>
2441 // <enum-type>   ::= W4 <name>
2442 void MicrosoftCXXNameMangler::mangleTagTypeKind(TagTypeKind TTK) {
2443   switch (TTK) {
2444     case TTK_Union:
2445       Out << 'T';
2446       break;
2447     case TTK_Struct:
2448     case TTK_Interface:
2449       Out << 'U';
2450       break;
2451     case TTK_Class:
2452       Out << 'V';
2453       break;
2454     case TTK_Enum:
2455       Out << "W4";
2456       break;
2457   }
2458 }
2459 void MicrosoftCXXNameMangler::mangleType(const EnumType *T, Qualifiers,
2460                                          SourceRange) {
2461   mangleType(cast<TagType>(T)->getDecl());
2462 }
2463 void MicrosoftCXXNameMangler::mangleType(const RecordType *T, Qualifiers,
2464                                          SourceRange) {
2465   mangleType(cast<TagType>(T)->getDecl());
2466 }
2467 void MicrosoftCXXNameMangler::mangleType(const TagDecl *TD) {
2468   mangleTagTypeKind(TD->getTagKind());
2469   mangleName(TD);
2470 }
2471 
2472 // If you add a call to this, consider updating isArtificialTagType() too.
2473 void MicrosoftCXXNameMangler::mangleArtificialTagType(
2474     TagTypeKind TK, StringRef UnqualifiedName,
2475     ArrayRef<StringRef> NestedNames) {
2476   // <name> ::= <unscoped-name> {[<named-scope>]+ | [<nested-name>]}? @
2477   mangleTagTypeKind(TK);
2478 
2479   // Always start with the unqualified name.
2480   mangleSourceName(UnqualifiedName);
2481 
2482   for (auto I = NestedNames.rbegin(), E = NestedNames.rend(); I != E; ++I)
2483     mangleSourceName(*I);
2484 
2485   // Terminate the whole name with an '@'.
2486   Out << '@';
2487 }
2488 
2489 // <type>       ::= <array-type>
2490 // <array-type> ::= <pointer-cvr-qualifiers> <cvr-qualifiers>
2491 //                  [Y <dimension-count> <dimension>+]
2492 //                  <element-type> # as global, E is never required
2493 // It's supposed to be the other way around, but for some strange reason, it
2494 // isn't. Today this behavior is retained for the sole purpose of backwards
2495 // compatibility.
2496 void MicrosoftCXXNameMangler::mangleDecayedArrayType(const ArrayType *T) {
2497   // This isn't a recursive mangling, so now we have to do it all in this
2498   // one call.
2499   manglePointerCVQualifiers(T->getElementType().getQualifiers());
2500   mangleType(T->getElementType(), SourceRange());
2501 }
2502 void MicrosoftCXXNameMangler::mangleType(const ConstantArrayType *T, Qualifiers,
2503                                          SourceRange) {
2504   llvm_unreachable("Should have been special cased");
2505 }
2506 void MicrosoftCXXNameMangler::mangleType(const VariableArrayType *T, Qualifiers,
2507                                          SourceRange) {
2508   llvm_unreachable("Should have been special cased");
2509 }
2510 void MicrosoftCXXNameMangler::mangleType(const DependentSizedArrayType *T,
2511                                          Qualifiers, SourceRange) {
2512   llvm_unreachable("Should have been special cased");
2513 }
2514 void MicrosoftCXXNameMangler::mangleType(const IncompleteArrayType *T,
2515                                          Qualifiers, SourceRange) {
2516   llvm_unreachable("Should have been special cased");
2517 }
2518 void MicrosoftCXXNameMangler::mangleArrayType(const ArrayType *T) {
2519   QualType ElementTy(T, 0);
2520   SmallVector<llvm::APInt, 3> Dimensions;
2521   for (;;) {
2522     if (ElementTy->isConstantArrayType()) {
2523       const ConstantArrayType *CAT =
2524           getASTContext().getAsConstantArrayType(ElementTy);
2525       Dimensions.push_back(CAT->getSize());
2526       ElementTy = CAT->getElementType();
2527     } else if (ElementTy->isIncompleteArrayType()) {
2528       const IncompleteArrayType *IAT =
2529           getASTContext().getAsIncompleteArrayType(ElementTy);
2530       Dimensions.push_back(llvm::APInt(32, 0));
2531       ElementTy = IAT->getElementType();
2532     } else if (ElementTy->isVariableArrayType()) {
2533       const VariableArrayType *VAT =
2534         getASTContext().getAsVariableArrayType(ElementTy);
2535       Dimensions.push_back(llvm::APInt(32, 0));
2536       ElementTy = VAT->getElementType();
2537     } else if (ElementTy->isDependentSizedArrayType()) {
2538       // The dependent expression has to be folded into a constant (TODO).
2539       const DependentSizedArrayType *DSAT =
2540         getASTContext().getAsDependentSizedArrayType(ElementTy);
2541       DiagnosticsEngine &Diags = Context.getDiags();
2542       unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2543         "cannot mangle this dependent-length array yet");
2544       Diags.Report(DSAT->getSizeExpr()->getExprLoc(), DiagID)
2545         << DSAT->getBracketsRange();
2546       return;
2547     } else {
2548       break;
2549     }
2550   }
2551   Out << 'Y';
2552   // <dimension-count> ::= <number> # number of extra dimensions
2553   mangleNumber(Dimensions.size());
2554   for (const llvm::APInt &Dimension : Dimensions)
2555     mangleNumber(Dimension.getLimitedValue());
2556   mangleType(ElementTy, SourceRange(), QMM_Escape);
2557 }
2558 
2559 // <type>                   ::= <pointer-to-member-type>
2560 // <pointer-to-member-type> ::= <pointer-cvr-qualifiers> <cvr-qualifiers>
2561 //                                                          <class name> <type>
2562 void MicrosoftCXXNameMangler::mangleType(const MemberPointerType *T,
2563                                          Qualifiers Quals, SourceRange Range) {
2564   QualType PointeeType = T->getPointeeType();
2565   manglePointerCVQualifiers(Quals);
2566   manglePointerExtQualifiers(Quals, PointeeType);
2567   if (const FunctionProtoType *FPT = PointeeType->getAs<FunctionProtoType>()) {
2568     Out << '8';
2569     mangleName(T->getClass()->castAs<RecordType>()->getDecl());
2570     mangleFunctionType(FPT, nullptr, true);
2571   } else {
2572     mangleQualifiers(PointeeType.getQualifiers(), true);
2573     mangleName(T->getClass()->castAs<RecordType>()->getDecl());
2574     mangleType(PointeeType, Range, QMM_Drop);
2575   }
2576 }
2577 
2578 void MicrosoftCXXNameMangler::mangleType(const TemplateTypeParmType *T,
2579                                          Qualifiers, SourceRange Range) {
2580   DiagnosticsEngine &Diags = Context.getDiags();
2581   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2582     "cannot mangle this template type parameter type yet");
2583   Diags.Report(Range.getBegin(), DiagID)
2584     << Range;
2585 }
2586 
2587 void MicrosoftCXXNameMangler::mangleType(const SubstTemplateTypeParmPackType *T,
2588                                          Qualifiers, SourceRange Range) {
2589   DiagnosticsEngine &Diags = Context.getDiags();
2590   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2591     "cannot mangle this substituted parameter pack yet");
2592   Diags.Report(Range.getBegin(), DiagID)
2593     << Range;
2594 }
2595 
2596 // <type> ::= <pointer-type>
2597 // <pointer-type> ::= E? <pointer-cvr-qualifiers> <cvr-qualifiers> <type>
2598 //                       # the E is required for 64-bit non-static pointers
2599 void MicrosoftCXXNameMangler::mangleType(const PointerType *T, Qualifiers Quals,
2600                                          SourceRange Range) {
2601   QualType PointeeType = T->getPointeeType();
2602   manglePointerCVQualifiers(Quals);
2603   manglePointerExtQualifiers(Quals, PointeeType);
2604 
2605   if (PointeeType.getQualifiers().hasAddressSpace())
2606     mangleAddressSpaceType(PointeeType, PointeeType.getQualifiers(), Range);
2607   else
2608     mangleType(PointeeType, Range);
2609 }
2610 
2611 void MicrosoftCXXNameMangler::mangleType(const ObjCObjectPointerType *T,
2612                                          Qualifiers Quals, SourceRange Range) {
2613   QualType PointeeType = T->getPointeeType();
2614   switch (Quals.getObjCLifetime()) {
2615   case Qualifiers::OCL_None:
2616   case Qualifiers::OCL_ExplicitNone:
2617     break;
2618   case Qualifiers::OCL_Autoreleasing:
2619   case Qualifiers::OCL_Strong:
2620   case Qualifiers::OCL_Weak:
2621     return mangleObjCLifetime(PointeeType, Quals, Range);
2622   }
2623   manglePointerCVQualifiers(Quals);
2624   manglePointerExtQualifiers(Quals, PointeeType);
2625   mangleType(PointeeType, Range);
2626 }
2627 
2628 // <type> ::= <reference-type>
2629 // <reference-type> ::= A E? <cvr-qualifiers> <type>
2630 //                 # the E is required for 64-bit non-static lvalue references
2631 void MicrosoftCXXNameMangler::mangleType(const LValueReferenceType *T,
2632                                          Qualifiers Quals, SourceRange Range) {
2633   QualType PointeeType = T->getPointeeType();
2634   assert(!Quals.hasConst() && !Quals.hasVolatile() && "unexpected qualifier!");
2635   Out << 'A';
2636   manglePointerExtQualifiers(Quals, PointeeType);
2637   mangleType(PointeeType, Range);
2638 }
2639 
2640 // <type> ::= <r-value-reference-type>
2641 // <r-value-reference-type> ::= $$Q E? <cvr-qualifiers> <type>
2642 //                 # the E is required for 64-bit non-static rvalue references
2643 void MicrosoftCXXNameMangler::mangleType(const RValueReferenceType *T,
2644                                          Qualifiers Quals, SourceRange Range) {
2645   QualType PointeeType = T->getPointeeType();
2646   assert(!Quals.hasConst() && !Quals.hasVolatile() && "unexpected qualifier!");
2647   Out << "$$Q";
2648   manglePointerExtQualifiers(Quals, PointeeType);
2649   mangleType(PointeeType, Range);
2650 }
2651 
2652 void MicrosoftCXXNameMangler::mangleType(const ComplexType *T, Qualifiers,
2653                                          SourceRange Range) {
2654   QualType ElementType = T->getElementType();
2655 
2656   llvm::SmallString<64> TemplateMangling;
2657   llvm::raw_svector_ostream Stream(TemplateMangling);
2658   MicrosoftCXXNameMangler Extra(Context, Stream);
2659   Stream << "?$";
2660   Extra.mangleSourceName("_Complex");
2661   Extra.mangleType(ElementType, Range, QMM_Escape);
2662 
2663   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__clang"});
2664 }
2665 
2666 // Returns true for types that mangleArtificialTagType() gets called for with
2667 // TTK_Union, TTK_Struct, TTK_Class and where compatibility with MSVC's
2668 // mangling matters.
2669 // (It doesn't matter for Objective-C types and the like that cl.exe doesn't
2670 // support.)
2671 bool MicrosoftCXXNameMangler::isArtificialTagType(QualType T) const {
2672   const Type *ty = T.getTypePtr();
2673   switch (ty->getTypeClass()) {
2674   default:
2675     return false;
2676 
2677   case Type::Vector: {
2678     // For ABI compatibility only __m64, __m128(id), and __m256(id) matter,
2679     // but since mangleType(VectorType*) always calls mangleArtificialTagType()
2680     // just always return true (the other vector types are clang-only).
2681     return true;
2682   }
2683   }
2684 }
2685 
2686 void MicrosoftCXXNameMangler::mangleType(const VectorType *T, Qualifiers Quals,
2687                                          SourceRange Range) {
2688   const BuiltinType *ET = T->getElementType()->getAs<BuiltinType>();
2689   assert(ET && "vectors with non-builtin elements are unsupported");
2690   uint64_t Width = getASTContext().getTypeSize(T);
2691   // Pattern match exactly the typedefs in our intrinsic headers.  Anything that
2692   // doesn't match the Intel types uses a custom mangling below.
2693   size_t OutSizeBefore = Out.tell();
2694   if (!isa<ExtVectorType>(T)) {
2695     llvm::Triple::ArchType AT =
2696         getASTContext().getTargetInfo().getTriple().getArch();
2697     if (AT == llvm::Triple::x86 || AT == llvm::Triple::x86_64) {
2698       if (Width == 64 && ET->getKind() == BuiltinType::LongLong) {
2699         mangleArtificialTagType(TTK_Union, "__m64");
2700       } else if (Width >= 128) {
2701         if (ET->getKind() == BuiltinType::Float)
2702           mangleArtificialTagType(TTK_Union, "__m" + llvm::utostr(Width));
2703         else if (ET->getKind() == BuiltinType::LongLong)
2704           mangleArtificialTagType(TTK_Union, "__m" + llvm::utostr(Width) + 'i');
2705         else if (ET->getKind() == BuiltinType::Double)
2706           mangleArtificialTagType(TTK_Struct, "__m" + llvm::utostr(Width) + 'd');
2707       }
2708     }
2709   }
2710 
2711   bool IsBuiltin = Out.tell() != OutSizeBefore;
2712   if (!IsBuiltin) {
2713     // The MS ABI doesn't have a special mangling for vector types, so we define
2714     // our own mangling to handle uses of __vector_size__ on user-specified
2715     // types, and for extensions like __v4sf.
2716 
2717     llvm::SmallString<64> TemplateMangling;
2718     llvm::raw_svector_ostream Stream(TemplateMangling);
2719     MicrosoftCXXNameMangler Extra(Context, Stream);
2720     Stream << "?$";
2721     Extra.mangleSourceName("__vector");
2722     Extra.mangleType(QualType(ET, 0), Range, QMM_Escape);
2723     Extra.mangleIntegerLiteral(llvm::APSInt::getUnsigned(T->getNumElements()),
2724                                /*IsBoolean=*/false);
2725 
2726     mangleArtificialTagType(TTK_Union, TemplateMangling, {"__clang"});
2727   }
2728 }
2729 
2730 void MicrosoftCXXNameMangler::mangleType(const ExtVectorType *T,
2731                                          Qualifiers Quals, SourceRange Range) {
2732   mangleType(static_cast<const VectorType *>(T), Quals, Range);
2733 }
2734 
2735 void MicrosoftCXXNameMangler::mangleType(const DependentVectorType *T,
2736                                          Qualifiers, SourceRange Range) {
2737   DiagnosticsEngine &Diags = Context.getDiags();
2738   unsigned DiagID = Diags.getCustomDiagID(
2739       DiagnosticsEngine::Error,
2740       "cannot mangle this dependent-sized vector type yet");
2741   Diags.Report(Range.getBegin(), DiagID) << Range;
2742 }
2743 
2744 void MicrosoftCXXNameMangler::mangleType(const DependentSizedExtVectorType *T,
2745                                          Qualifiers, SourceRange Range) {
2746   DiagnosticsEngine &Diags = Context.getDiags();
2747   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2748     "cannot mangle this dependent-sized extended vector type yet");
2749   Diags.Report(Range.getBegin(), DiagID)
2750     << Range;
2751 }
2752 
2753 void MicrosoftCXXNameMangler::mangleType(const DependentAddressSpaceType *T,
2754                                          Qualifiers, SourceRange Range) {
2755   DiagnosticsEngine &Diags = Context.getDiags();
2756   unsigned DiagID = Diags.getCustomDiagID(
2757       DiagnosticsEngine::Error,
2758       "cannot mangle this dependent address space type yet");
2759   Diags.Report(Range.getBegin(), DiagID) << Range;
2760 }
2761 
2762 void MicrosoftCXXNameMangler::mangleType(const ObjCInterfaceType *T, Qualifiers,
2763                                          SourceRange) {
2764   // ObjC interfaces have structs underlying them.
2765   mangleTagTypeKind(TTK_Struct);
2766   mangleName(T->getDecl());
2767 }
2768 
2769 void MicrosoftCXXNameMangler::mangleType(const ObjCObjectType *T,
2770                                          Qualifiers Quals, SourceRange Range) {
2771   if (T->isKindOfType())
2772     return mangleObjCKindOfType(T, Quals, Range);
2773 
2774   if (T->qual_empty() && !T->isSpecialized())
2775     return mangleType(T->getBaseType(), Range, QMM_Drop);
2776 
2777   ArgBackRefMap OuterFunArgsContext;
2778   ArgBackRefMap OuterTemplateArgsContext;
2779   BackRefVec OuterTemplateContext;
2780 
2781   FunArgBackReferences.swap(OuterFunArgsContext);
2782   TemplateArgBackReferences.swap(OuterTemplateArgsContext);
2783   NameBackReferences.swap(OuterTemplateContext);
2784 
2785   mangleTagTypeKind(TTK_Struct);
2786 
2787   Out << "?$";
2788   if (T->isObjCId())
2789     mangleSourceName("objc_object");
2790   else if (T->isObjCClass())
2791     mangleSourceName("objc_class");
2792   else
2793     mangleSourceName(T->getInterface()->getName());
2794 
2795   for (const auto &Q : T->quals())
2796     mangleObjCProtocol(Q);
2797 
2798   if (T->isSpecialized())
2799     for (const auto &TA : T->getTypeArgs())
2800       mangleType(TA, Range, QMM_Drop);
2801 
2802   Out << '@';
2803 
2804   Out << '@';
2805 
2806   FunArgBackReferences.swap(OuterFunArgsContext);
2807   TemplateArgBackReferences.swap(OuterTemplateArgsContext);
2808   NameBackReferences.swap(OuterTemplateContext);
2809 }
2810 
2811 void MicrosoftCXXNameMangler::mangleType(const BlockPointerType *T,
2812                                          Qualifiers Quals, SourceRange Range) {
2813   QualType PointeeType = T->getPointeeType();
2814   manglePointerCVQualifiers(Quals);
2815   manglePointerExtQualifiers(Quals, PointeeType);
2816 
2817   Out << "_E";
2818 
2819   mangleFunctionType(PointeeType->castAs<FunctionProtoType>());
2820 }
2821 
2822 void MicrosoftCXXNameMangler::mangleType(const InjectedClassNameType *,
2823                                          Qualifiers, SourceRange) {
2824   llvm_unreachable("Cannot mangle injected class name type.");
2825 }
2826 
2827 void MicrosoftCXXNameMangler::mangleType(const TemplateSpecializationType *T,
2828                                          Qualifiers, SourceRange Range) {
2829   DiagnosticsEngine &Diags = Context.getDiags();
2830   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2831     "cannot mangle this template specialization type yet");
2832   Diags.Report(Range.getBegin(), DiagID)
2833     << Range;
2834 }
2835 
2836 void MicrosoftCXXNameMangler::mangleType(const DependentNameType *T, Qualifiers,
2837                                          SourceRange Range) {
2838   DiagnosticsEngine &Diags = Context.getDiags();
2839   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2840     "cannot mangle this dependent name type yet");
2841   Diags.Report(Range.getBegin(), DiagID)
2842     << Range;
2843 }
2844 
2845 void MicrosoftCXXNameMangler::mangleType(
2846     const DependentTemplateSpecializationType *T, Qualifiers,
2847     SourceRange Range) {
2848   DiagnosticsEngine &Diags = Context.getDiags();
2849   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2850     "cannot mangle this dependent template specialization type yet");
2851   Diags.Report(Range.getBegin(), DiagID)
2852     << Range;
2853 }
2854 
2855 void MicrosoftCXXNameMangler::mangleType(const PackExpansionType *T, Qualifiers,
2856                                          SourceRange Range) {
2857   DiagnosticsEngine &Diags = Context.getDiags();
2858   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2859     "cannot mangle this pack expansion yet");
2860   Diags.Report(Range.getBegin(), DiagID)
2861     << Range;
2862 }
2863 
2864 void MicrosoftCXXNameMangler::mangleType(const TypeOfType *T, Qualifiers,
2865                                          SourceRange Range) {
2866   DiagnosticsEngine &Diags = Context.getDiags();
2867   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2868     "cannot mangle this typeof(type) yet");
2869   Diags.Report(Range.getBegin(), DiagID)
2870     << Range;
2871 }
2872 
2873 void MicrosoftCXXNameMangler::mangleType(const TypeOfExprType *T, Qualifiers,
2874                                          SourceRange Range) {
2875   DiagnosticsEngine &Diags = Context.getDiags();
2876   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2877     "cannot mangle this typeof(expression) yet");
2878   Diags.Report(Range.getBegin(), DiagID)
2879     << Range;
2880 }
2881 
2882 void MicrosoftCXXNameMangler::mangleType(const DecltypeType *T, Qualifiers,
2883                                          SourceRange Range) {
2884   DiagnosticsEngine &Diags = Context.getDiags();
2885   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2886     "cannot mangle this decltype() yet");
2887   Diags.Report(Range.getBegin(), DiagID)
2888     << Range;
2889 }
2890 
2891 void MicrosoftCXXNameMangler::mangleType(const UnaryTransformType *T,
2892                                          Qualifiers, SourceRange Range) {
2893   DiagnosticsEngine &Diags = Context.getDiags();
2894   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2895     "cannot mangle this unary transform type yet");
2896   Diags.Report(Range.getBegin(), DiagID)
2897     << Range;
2898 }
2899 
2900 void MicrosoftCXXNameMangler::mangleType(const AutoType *T, Qualifiers,
2901                                          SourceRange Range) {
2902   assert(T->getDeducedType().isNull() && "expecting a dependent type!");
2903 
2904   DiagnosticsEngine &Diags = Context.getDiags();
2905   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2906     "cannot mangle this 'auto' type yet");
2907   Diags.Report(Range.getBegin(), DiagID)
2908     << Range;
2909 }
2910 
2911 void MicrosoftCXXNameMangler::mangleType(
2912     const DeducedTemplateSpecializationType *T, Qualifiers, SourceRange Range) {
2913   assert(T->getDeducedType().isNull() && "expecting a dependent type!");
2914 
2915   DiagnosticsEngine &Diags = Context.getDiags();
2916   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2917     "cannot mangle this deduced class template specialization type yet");
2918   Diags.Report(Range.getBegin(), DiagID)
2919     << Range;
2920 }
2921 
2922 void MicrosoftCXXNameMangler::mangleType(const AtomicType *T, Qualifiers,
2923                                          SourceRange Range) {
2924   QualType ValueType = T->getValueType();
2925 
2926   llvm::SmallString<64> TemplateMangling;
2927   llvm::raw_svector_ostream Stream(TemplateMangling);
2928   MicrosoftCXXNameMangler Extra(Context, Stream);
2929   Stream << "?$";
2930   Extra.mangleSourceName("_Atomic");
2931   Extra.mangleType(ValueType, Range, QMM_Escape);
2932 
2933   mangleArtificialTagType(TTK_Struct, TemplateMangling, {"__clang"});
2934 }
2935 
2936 void MicrosoftCXXNameMangler::mangleType(const PipeType *T, Qualifiers,
2937                                          SourceRange Range) {
2938   DiagnosticsEngine &Diags = Context.getDiags();
2939   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
2940     "cannot mangle this OpenCL pipe type yet");
2941   Diags.Report(Range.getBegin(), DiagID)
2942     << Range;
2943 }
2944 
2945 void MicrosoftMangleContextImpl::mangleCXXName(const NamedDecl *D,
2946                                                raw_ostream &Out) {
2947   assert((isa<FunctionDecl>(D) || isa<VarDecl>(D)) &&
2948          "Invalid mangleName() call, argument is not a variable or function!");
2949   assert(!isa<CXXConstructorDecl>(D) && !isa<CXXDestructorDecl>(D) &&
2950          "Invalid mangleName() call on 'structor decl!");
2951 
2952   PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
2953                                  getASTContext().getSourceManager(),
2954                                  "Mangling declaration");
2955 
2956   msvc_hashing_ostream MHO(Out);
2957   MicrosoftCXXNameMangler Mangler(*this, MHO);
2958   return Mangler.mangle(D);
2959 }
2960 
2961 // <this-adjustment> ::= <no-adjustment> | <static-adjustment> |
2962 //                       <virtual-adjustment>
2963 // <no-adjustment>      ::= A # private near
2964 //                      ::= B # private far
2965 //                      ::= I # protected near
2966 //                      ::= J # protected far
2967 //                      ::= Q # public near
2968 //                      ::= R # public far
2969 // <static-adjustment>  ::= G <static-offset> # private near
2970 //                      ::= H <static-offset> # private far
2971 //                      ::= O <static-offset> # protected near
2972 //                      ::= P <static-offset> # protected far
2973 //                      ::= W <static-offset> # public near
2974 //                      ::= X <static-offset> # public far
2975 // <virtual-adjustment> ::= $0 <virtual-shift> <static-offset> # private near
2976 //                      ::= $1 <virtual-shift> <static-offset> # private far
2977 //                      ::= $2 <virtual-shift> <static-offset> # protected near
2978 //                      ::= $3 <virtual-shift> <static-offset> # protected far
2979 //                      ::= $4 <virtual-shift> <static-offset> # public near
2980 //                      ::= $5 <virtual-shift> <static-offset> # public far
2981 // <virtual-shift>      ::= <vtordisp-shift> | <vtordispex-shift>
2982 // <vtordisp-shift>     ::= <offset-to-vtordisp>
2983 // <vtordispex-shift>   ::= <offset-to-vbptr> <vbase-offset-offset>
2984 //                          <offset-to-vtordisp>
2985 static void mangleThunkThisAdjustment(AccessSpecifier AS,
2986                                       const ThisAdjustment &Adjustment,
2987                                       MicrosoftCXXNameMangler &Mangler,
2988                                       raw_ostream &Out) {
2989   if (!Adjustment.Virtual.isEmpty()) {
2990     Out << '$';
2991     char AccessSpec;
2992     switch (AS) {
2993     case AS_none:
2994       llvm_unreachable("Unsupported access specifier");
2995     case AS_private:
2996       AccessSpec = '0';
2997       break;
2998     case AS_protected:
2999       AccessSpec = '2';
3000       break;
3001     case AS_public:
3002       AccessSpec = '4';
3003     }
3004     if (Adjustment.Virtual.Microsoft.VBPtrOffset) {
3005       Out << 'R' << AccessSpec;
3006       Mangler.mangleNumber(
3007           static_cast<uint32_t>(Adjustment.Virtual.Microsoft.VBPtrOffset));
3008       Mangler.mangleNumber(
3009           static_cast<uint32_t>(Adjustment.Virtual.Microsoft.VBOffsetOffset));
3010       Mangler.mangleNumber(
3011           static_cast<uint32_t>(Adjustment.Virtual.Microsoft.VtordispOffset));
3012       Mangler.mangleNumber(static_cast<uint32_t>(Adjustment.NonVirtual));
3013     } else {
3014       Out << AccessSpec;
3015       Mangler.mangleNumber(
3016           static_cast<uint32_t>(Adjustment.Virtual.Microsoft.VtordispOffset));
3017       Mangler.mangleNumber(-static_cast<uint32_t>(Adjustment.NonVirtual));
3018     }
3019   } else if (Adjustment.NonVirtual != 0) {
3020     switch (AS) {
3021     case AS_none:
3022       llvm_unreachable("Unsupported access specifier");
3023     case AS_private:
3024       Out << 'G';
3025       break;
3026     case AS_protected:
3027       Out << 'O';
3028       break;
3029     case AS_public:
3030       Out << 'W';
3031     }
3032     Mangler.mangleNumber(-static_cast<uint32_t>(Adjustment.NonVirtual));
3033   } else {
3034     switch (AS) {
3035     case AS_none:
3036       llvm_unreachable("Unsupported access specifier");
3037     case AS_private:
3038       Out << 'A';
3039       break;
3040     case AS_protected:
3041       Out << 'I';
3042       break;
3043     case AS_public:
3044       Out << 'Q';
3045     }
3046   }
3047 }
3048 
3049 void MicrosoftMangleContextImpl::mangleVirtualMemPtrThunk(
3050     const CXXMethodDecl *MD, const MethodVFTableLocation &ML,
3051     raw_ostream &Out) {
3052   msvc_hashing_ostream MHO(Out);
3053   MicrosoftCXXNameMangler Mangler(*this, MHO);
3054   Mangler.getStream() << '?';
3055   Mangler.mangleVirtualMemPtrThunk(MD, ML);
3056 }
3057 
3058 void MicrosoftMangleContextImpl::mangleThunk(const CXXMethodDecl *MD,
3059                                              const ThunkInfo &Thunk,
3060                                              raw_ostream &Out) {
3061   msvc_hashing_ostream MHO(Out);
3062   MicrosoftCXXNameMangler Mangler(*this, MHO);
3063   Mangler.getStream() << '?';
3064   Mangler.mangleName(MD);
3065 
3066   // Usually the thunk uses the access specifier of the new method, but if this
3067   // is a covariant return thunk, then MSVC always uses the public access
3068   // specifier, and we do the same.
3069   AccessSpecifier AS = Thunk.Return.isEmpty() ? MD->getAccess() : AS_public;
3070   mangleThunkThisAdjustment(AS, Thunk.This, Mangler, MHO);
3071 
3072   if (!Thunk.Return.isEmpty())
3073     assert(Thunk.Method != nullptr &&
3074            "Thunk info should hold the overridee decl");
3075 
3076   const CXXMethodDecl *DeclForFPT = Thunk.Method ? Thunk.Method : MD;
3077   Mangler.mangleFunctionType(
3078       DeclForFPT->getType()->castAs<FunctionProtoType>(), MD);
3079 }
3080 
3081 void MicrosoftMangleContextImpl::mangleCXXDtorThunk(
3082     const CXXDestructorDecl *DD, CXXDtorType Type,
3083     const ThisAdjustment &Adjustment, raw_ostream &Out) {
3084   // FIXME: Actually, the dtor thunk should be emitted for vector deleting
3085   // dtors rather than scalar deleting dtors. Just use the vector deleting dtor
3086   // mangling manually until we support both deleting dtor types.
3087   assert(Type == Dtor_Deleting);
3088   msvc_hashing_ostream MHO(Out);
3089   MicrosoftCXXNameMangler Mangler(*this, MHO, DD, Type);
3090   Mangler.getStream() << "??_E";
3091   Mangler.mangleName(DD->getParent());
3092   mangleThunkThisAdjustment(DD->getAccess(), Adjustment, Mangler, MHO);
3093   Mangler.mangleFunctionType(DD->getType()->castAs<FunctionProtoType>(), DD);
3094 }
3095 
3096 void MicrosoftMangleContextImpl::mangleCXXVFTable(
3097     const CXXRecordDecl *Derived, ArrayRef<const CXXRecordDecl *> BasePath,
3098     raw_ostream &Out) {
3099   // <mangled-name> ::= ?_7 <class-name> <storage-class>
3100   //                    <cvr-qualifiers> [<name>] @
3101   // NOTE: <cvr-qualifiers> here is always 'B' (const). <storage-class>
3102   // is always '6' for vftables.
3103   msvc_hashing_ostream MHO(Out);
3104   MicrosoftCXXNameMangler Mangler(*this, MHO);
3105   if (Derived->hasAttr<DLLImportAttr>())
3106     Mangler.getStream() << "??_S";
3107   else
3108     Mangler.getStream() << "??_7";
3109   Mangler.mangleName(Derived);
3110   Mangler.getStream() << "6B"; // '6' for vftable, 'B' for const.
3111   for (const CXXRecordDecl *RD : BasePath)
3112     Mangler.mangleName(RD);
3113   Mangler.getStream() << '@';
3114 }
3115 
3116 void MicrosoftMangleContextImpl::mangleCXXVBTable(
3117     const CXXRecordDecl *Derived, ArrayRef<const CXXRecordDecl *> BasePath,
3118     raw_ostream &Out) {
3119   // <mangled-name> ::= ?_8 <class-name> <storage-class>
3120   //                    <cvr-qualifiers> [<name>] @
3121   // NOTE: <cvr-qualifiers> here is always 'B' (const). <storage-class>
3122   // is always '7' for vbtables.
3123   msvc_hashing_ostream MHO(Out);
3124   MicrosoftCXXNameMangler Mangler(*this, MHO);
3125   Mangler.getStream() << "??_8";
3126   Mangler.mangleName(Derived);
3127   Mangler.getStream() << "7B";  // '7' for vbtable, 'B' for const.
3128   for (const CXXRecordDecl *RD : BasePath)
3129     Mangler.mangleName(RD);
3130   Mangler.getStream() << '@';
3131 }
3132 
3133 void MicrosoftMangleContextImpl::mangleCXXRTTI(QualType T, raw_ostream &Out) {
3134   msvc_hashing_ostream MHO(Out);
3135   MicrosoftCXXNameMangler Mangler(*this, MHO);
3136   Mangler.getStream() << "??_R0";
3137   Mangler.mangleType(T, SourceRange(), MicrosoftCXXNameMangler::QMM_Result);
3138   Mangler.getStream() << "@8";
3139 }
3140 
3141 void MicrosoftMangleContextImpl::mangleCXXRTTIName(QualType T,
3142                                                    raw_ostream &Out) {
3143   MicrosoftCXXNameMangler Mangler(*this, Out);
3144   Mangler.getStream() << '.';
3145   Mangler.mangleType(T, SourceRange(), MicrosoftCXXNameMangler::QMM_Result);
3146 }
3147 
3148 void MicrosoftMangleContextImpl::mangleCXXVirtualDisplacementMap(
3149     const CXXRecordDecl *SrcRD, const CXXRecordDecl *DstRD, raw_ostream &Out) {
3150   msvc_hashing_ostream MHO(Out);
3151   MicrosoftCXXNameMangler Mangler(*this, MHO);
3152   Mangler.getStream() << "??_K";
3153   Mangler.mangleName(SrcRD);
3154   Mangler.getStream() << "$C";
3155   Mangler.mangleName(DstRD);
3156 }
3157 
3158 void MicrosoftMangleContextImpl::mangleCXXThrowInfo(QualType T, bool IsConst,
3159                                                     bool IsVolatile,
3160                                                     bool IsUnaligned,
3161                                                     uint32_t NumEntries,
3162                                                     raw_ostream &Out) {
3163   msvc_hashing_ostream MHO(Out);
3164   MicrosoftCXXNameMangler Mangler(*this, MHO);
3165   Mangler.getStream() << "_TI";
3166   if (IsConst)
3167     Mangler.getStream() << 'C';
3168   if (IsVolatile)
3169     Mangler.getStream() << 'V';
3170   if (IsUnaligned)
3171     Mangler.getStream() << 'U';
3172   Mangler.getStream() << NumEntries;
3173   Mangler.mangleType(T, SourceRange(), MicrosoftCXXNameMangler::QMM_Result);
3174 }
3175 
3176 void MicrosoftMangleContextImpl::mangleCXXCatchableTypeArray(
3177     QualType T, uint32_t NumEntries, raw_ostream &Out) {
3178   msvc_hashing_ostream MHO(Out);
3179   MicrosoftCXXNameMangler Mangler(*this, MHO);
3180   Mangler.getStream() << "_CTA";
3181   Mangler.getStream() << NumEntries;
3182   Mangler.mangleType(T, SourceRange(), MicrosoftCXXNameMangler::QMM_Result);
3183 }
3184 
3185 void MicrosoftMangleContextImpl::mangleCXXCatchableType(
3186     QualType T, const CXXConstructorDecl *CD, CXXCtorType CT, uint32_t Size,
3187     uint32_t NVOffset, int32_t VBPtrOffset, uint32_t VBIndex,
3188     raw_ostream &Out) {
3189   MicrosoftCXXNameMangler Mangler(*this, Out);
3190   Mangler.getStream() << "_CT";
3191 
3192   llvm::SmallString<64> RTTIMangling;
3193   {
3194     llvm::raw_svector_ostream Stream(RTTIMangling);
3195     msvc_hashing_ostream MHO(Stream);
3196     mangleCXXRTTI(T, MHO);
3197   }
3198   Mangler.getStream() << RTTIMangling;
3199 
3200   // VS2015 and VS2017.1 omit the copy-constructor in the mangled name but
3201   // both older and newer versions include it.
3202   // FIXME: It is known that the Ctor is present in 2013, and in 2017.7
3203   // (_MSC_VER 1914) and newer, and that it's omitted in 2015 and 2017.4
3204   // (_MSC_VER 1911), but it's unknown when exactly it reappeared (1914?
3205   // Or 1912, 1913 aleady?).
3206   bool OmitCopyCtor = getASTContext().getLangOpts().isCompatibleWithMSVC(
3207                           LangOptions::MSVC2015) &&
3208                       !getASTContext().getLangOpts().isCompatibleWithMSVC(
3209                           LangOptions::MSVC2017_7);
3210   llvm::SmallString<64> CopyCtorMangling;
3211   if (!OmitCopyCtor && CD) {
3212     llvm::raw_svector_ostream Stream(CopyCtorMangling);
3213     msvc_hashing_ostream MHO(Stream);
3214     mangleCXXCtor(CD, CT, MHO);
3215   }
3216   Mangler.getStream() << CopyCtorMangling;
3217 
3218   Mangler.getStream() << Size;
3219   if (VBPtrOffset == -1) {
3220     if (NVOffset) {
3221       Mangler.getStream() << NVOffset;
3222     }
3223   } else {
3224     Mangler.getStream() << NVOffset;
3225     Mangler.getStream() << VBPtrOffset;
3226     Mangler.getStream() << VBIndex;
3227   }
3228 }
3229 
3230 void MicrosoftMangleContextImpl::mangleCXXRTTIBaseClassDescriptor(
3231     const CXXRecordDecl *Derived, uint32_t NVOffset, int32_t VBPtrOffset,
3232     uint32_t VBTableOffset, uint32_t Flags, raw_ostream &Out) {
3233   msvc_hashing_ostream MHO(Out);
3234   MicrosoftCXXNameMangler Mangler(*this, MHO);
3235   Mangler.getStream() << "??_R1";
3236   Mangler.mangleNumber(NVOffset);
3237   Mangler.mangleNumber(VBPtrOffset);
3238   Mangler.mangleNumber(VBTableOffset);
3239   Mangler.mangleNumber(Flags);
3240   Mangler.mangleName(Derived);
3241   Mangler.getStream() << "8";
3242 }
3243 
3244 void MicrosoftMangleContextImpl::mangleCXXRTTIBaseClassArray(
3245     const CXXRecordDecl *Derived, raw_ostream &Out) {
3246   msvc_hashing_ostream MHO(Out);
3247   MicrosoftCXXNameMangler Mangler(*this, MHO);
3248   Mangler.getStream() << "??_R2";
3249   Mangler.mangleName(Derived);
3250   Mangler.getStream() << "8";
3251 }
3252 
3253 void MicrosoftMangleContextImpl::mangleCXXRTTIClassHierarchyDescriptor(
3254     const CXXRecordDecl *Derived, raw_ostream &Out) {
3255   msvc_hashing_ostream MHO(Out);
3256   MicrosoftCXXNameMangler Mangler(*this, MHO);
3257   Mangler.getStream() << "??_R3";
3258   Mangler.mangleName(Derived);
3259   Mangler.getStream() << "8";
3260 }
3261 
3262 void MicrosoftMangleContextImpl::mangleCXXRTTICompleteObjectLocator(
3263     const CXXRecordDecl *Derived, ArrayRef<const CXXRecordDecl *> BasePath,
3264     raw_ostream &Out) {
3265   // <mangled-name> ::= ?_R4 <class-name> <storage-class>
3266   //                    <cvr-qualifiers> [<name>] @
3267   // NOTE: <cvr-qualifiers> here is always 'B' (const). <storage-class>
3268   // is always '6' for vftables.
3269   llvm::SmallString<64> VFTableMangling;
3270   llvm::raw_svector_ostream Stream(VFTableMangling);
3271   mangleCXXVFTable(Derived, BasePath, Stream);
3272 
3273   if (VFTableMangling.startswith("??@")) {
3274     assert(VFTableMangling.endswith("@"));
3275     Out << VFTableMangling << "??_R4@";
3276     return;
3277   }
3278 
3279   assert(VFTableMangling.startswith("??_7") ||
3280          VFTableMangling.startswith("??_S"));
3281 
3282   Out << "??_R4" << StringRef(VFTableMangling).drop_front(4);
3283 }
3284 
3285 void MicrosoftMangleContextImpl::mangleSEHFilterExpression(
3286     const NamedDecl *EnclosingDecl, raw_ostream &Out) {
3287   msvc_hashing_ostream MHO(Out);
3288   MicrosoftCXXNameMangler Mangler(*this, MHO);
3289   // The function body is in the same comdat as the function with the handler,
3290   // so the numbering here doesn't have to be the same across TUs.
3291   //
3292   // <mangled-name> ::= ?filt$ <filter-number> @0
3293   Mangler.getStream() << "?filt$" << SEHFilterIds[EnclosingDecl]++ << "@0@";
3294   Mangler.mangleName(EnclosingDecl);
3295 }
3296 
3297 void MicrosoftMangleContextImpl::mangleSEHFinallyBlock(
3298     const NamedDecl *EnclosingDecl, raw_ostream &Out) {
3299   msvc_hashing_ostream MHO(Out);
3300   MicrosoftCXXNameMangler Mangler(*this, MHO);
3301   // The function body is in the same comdat as the function with the handler,
3302   // so the numbering here doesn't have to be the same across TUs.
3303   //
3304   // <mangled-name> ::= ?fin$ <filter-number> @0
3305   Mangler.getStream() << "?fin$" << SEHFinallyIds[EnclosingDecl]++ << "@0@";
3306   Mangler.mangleName(EnclosingDecl);
3307 }
3308 
3309 void MicrosoftMangleContextImpl::mangleTypeName(QualType T, raw_ostream &Out) {
3310   // This is just a made up unique string for the purposes of tbaa.  undname
3311   // does *not* know how to demangle it.
3312   MicrosoftCXXNameMangler Mangler(*this, Out);
3313   Mangler.getStream() << '?';
3314   Mangler.mangleType(T, SourceRange());
3315 }
3316 
3317 void MicrosoftMangleContextImpl::mangleCXXCtor(const CXXConstructorDecl *D,
3318                                                CXXCtorType Type,
3319                                                raw_ostream &Out) {
3320   msvc_hashing_ostream MHO(Out);
3321   MicrosoftCXXNameMangler mangler(*this, MHO, D, Type);
3322   mangler.mangle(D);
3323 }
3324 
3325 void MicrosoftMangleContextImpl::mangleCXXDtor(const CXXDestructorDecl *D,
3326                                                CXXDtorType Type,
3327                                                raw_ostream &Out) {
3328   msvc_hashing_ostream MHO(Out);
3329   MicrosoftCXXNameMangler mangler(*this, MHO, D, Type);
3330   mangler.mangle(D);
3331 }
3332 
3333 void MicrosoftMangleContextImpl::mangleReferenceTemporary(
3334     const VarDecl *VD, unsigned ManglingNumber, raw_ostream &Out) {
3335   msvc_hashing_ostream MHO(Out);
3336   MicrosoftCXXNameMangler Mangler(*this, MHO);
3337 
3338   Mangler.getStream() << "?$RT" << ManglingNumber << '@';
3339   Mangler.mangle(VD, "");
3340 }
3341 
3342 void MicrosoftMangleContextImpl::mangleThreadSafeStaticGuardVariable(
3343     const VarDecl *VD, unsigned GuardNum, raw_ostream &Out) {
3344   msvc_hashing_ostream MHO(Out);
3345   MicrosoftCXXNameMangler Mangler(*this, MHO);
3346 
3347   Mangler.getStream() << "?$TSS" << GuardNum << '@';
3348   Mangler.mangleNestedName(VD);
3349   Mangler.getStream() << "@4HA";
3350 }
3351 
3352 void MicrosoftMangleContextImpl::mangleStaticGuardVariable(const VarDecl *VD,
3353                                                            raw_ostream &Out) {
3354   // <guard-name> ::= ?_B <postfix> @5 <scope-depth>
3355   //              ::= ?__J <postfix> @5 <scope-depth>
3356   //              ::= ?$S <guard-num> @ <postfix> @4IA
3357 
3358   // The first mangling is what MSVC uses to guard static locals in inline
3359   // functions.  It uses a different mangling in external functions to support
3360   // guarding more than 32 variables.  MSVC rejects inline functions with more
3361   // than 32 static locals.  We don't fully implement the second mangling
3362   // because those guards are not externally visible, and instead use LLVM's
3363   // default renaming when creating a new guard variable.
3364   msvc_hashing_ostream MHO(Out);
3365   MicrosoftCXXNameMangler Mangler(*this, MHO);
3366 
3367   bool Visible = VD->isExternallyVisible();
3368   if (Visible) {
3369     Mangler.getStream() << (VD->getTLSKind() ? "??__J" : "??_B");
3370   } else {
3371     Mangler.getStream() << "?$S1@";
3372   }
3373   unsigned ScopeDepth = 0;
3374   if (Visible && !getNextDiscriminator(VD, ScopeDepth))
3375     // If we do not have a discriminator and are emitting a guard variable for
3376     // use at global scope, then mangling the nested name will not be enough to
3377     // remove ambiguities.
3378     Mangler.mangle(VD, "");
3379   else
3380     Mangler.mangleNestedName(VD);
3381   Mangler.getStream() << (Visible ? "@5" : "@4IA");
3382   if (ScopeDepth)
3383     Mangler.mangleNumber(ScopeDepth);
3384 }
3385 
3386 void MicrosoftMangleContextImpl::mangleInitFiniStub(const VarDecl *D,
3387                                                     char CharCode,
3388                                                     raw_ostream &Out) {
3389   msvc_hashing_ostream MHO(Out);
3390   MicrosoftCXXNameMangler Mangler(*this, MHO);
3391   Mangler.getStream() << "??__" << CharCode;
3392   if (D->isStaticDataMember()) {
3393     Mangler.getStream() << '?';
3394     Mangler.mangleName(D);
3395     Mangler.mangleVariableEncoding(D);
3396     Mangler.getStream() << "@@";
3397   } else {
3398     Mangler.mangleName(D);
3399   }
3400   // This is the function class mangling.  These stubs are global, non-variadic,
3401   // cdecl functions that return void and take no args.
3402   Mangler.getStream() << "YAXXZ";
3403 }
3404 
3405 void MicrosoftMangleContextImpl::mangleDynamicInitializer(const VarDecl *D,
3406                                                           raw_ostream &Out) {
3407   // <initializer-name> ::= ?__E <name> YAXXZ
3408   mangleInitFiniStub(D, 'E', Out);
3409 }
3410 
3411 void
3412 MicrosoftMangleContextImpl::mangleDynamicAtExitDestructor(const VarDecl *D,
3413                                                           raw_ostream &Out) {
3414   // <destructor-name> ::= ?__F <name> YAXXZ
3415   mangleInitFiniStub(D, 'F', Out);
3416 }
3417 
3418 void MicrosoftMangleContextImpl::mangleStringLiteral(const StringLiteral *SL,
3419                                                      raw_ostream &Out) {
3420   // <char-type> ::= 0   # char, char16_t, char32_t
3421   //                     # (little endian char data in mangling)
3422   //             ::= 1   # wchar_t (big endian char data in mangling)
3423   //
3424   // <literal-length> ::= <non-negative integer>  # the length of the literal
3425   //
3426   // <encoded-crc>    ::= <hex digit>+ @          # crc of the literal including
3427   //                                              # trailing null bytes
3428   //
3429   // <encoded-string> ::= <simple character>           # uninteresting character
3430   //                  ::= '?$' <hex digit> <hex digit> # these two nibbles
3431   //                                                   # encode the byte for the
3432   //                                                   # character
3433   //                  ::= '?' [a-z]                    # \xe1 - \xfa
3434   //                  ::= '?' [A-Z]                    # \xc1 - \xda
3435   //                  ::= '?' [0-9]                    # [,/\:. \n\t'-]
3436   //
3437   // <literal> ::= '??_C@_' <char-type> <literal-length> <encoded-crc>
3438   //               <encoded-string> '@'
3439   MicrosoftCXXNameMangler Mangler(*this, Out);
3440   Mangler.getStream() << "??_C@_";
3441 
3442   // The actual string length might be different from that of the string literal
3443   // in cases like:
3444   // char foo[3] = "foobar";
3445   // char bar[42] = "foobar";
3446   // Where it is truncated or zero-padded to fit the array. This is the length
3447   // used for mangling, and any trailing null-bytes also need to be mangled.
3448   unsigned StringLength = getASTContext()
3449                               .getAsConstantArrayType(SL->getType())
3450                               ->getSize()
3451                               .getZExtValue();
3452   unsigned StringByteLength = StringLength * SL->getCharByteWidth();
3453 
3454   // <char-type>: The "kind" of string literal is encoded into the mangled name.
3455   if (SL->isWide())
3456     Mangler.getStream() << '1';
3457   else
3458     Mangler.getStream() << '0';
3459 
3460   // <literal-length>: The next part of the mangled name consists of the length
3461   // of the string in bytes.
3462   Mangler.mangleNumber(StringByteLength);
3463 
3464   auto GetLittleEndianByte = [&SL](unsigned Index) {
3465     unsigned CharByteWidth = SL->getCharByteWidth();
3466     if (Index / CharByteWidth >= SL->getLength())
3467       return static_cast<char>(0);
3468     uint32_t CodeUnit = SL->getCodeUnit(Index / CharByteWidth);
3469     unsigned OffsetInCodeUnit = Index % CharByteWidth;
3470     return static_cast<char>((CodeUnit >> (8 * OffsetInCodeUnit)) & 0xff);
3471   };
3472 
3473   auto GetBigEndianByte = [&SL](unsigned Index) {
3474     unsigned CharByteWidth = SL->getCharByteWidth();
3475     if (Index / CharByteWidth >= SL->getLength())
3476       return static_cast<char>(0);
3477     uint32_t CodeUnit = SL->getCodeUnit(Index / CharByteWidth);
3478     unsigned OffsetInCodeUnit = (CharByteWidth - 1) - (Index % CharByteWidth);
3479     return static_cast<char>((CodeUnit >> (8 * OffsetInCodeUnit)) & 0xff);
3480   };
3481 
3482   // CRC all the bytes of the StringLiteral.
3483   llvm::JamCRC JC;
3484   for (unsigned I = 0, E = StringByteLength; I != E; ++I)
3485     JC.update(GetLittleEndianByte(I));
3486 
3487   // <encoded-crc>: The CRC is encoded utilizing the standard number mangling
3488   // scheme.
3489   Mangler.mangleNumber(JC.getCRC());
3490 
3491   // <encoded-string>: The mangled name also contains the first 32 bytes
3492   // (including null-terminator bytes) of the encoded StringLiteral.
3493   // Each character is encoded by splitting them into bytes and then encoding
3494   // the constituent bytes.
3495   auto MangleByte = [&Mangler](char Byte) {
3496     // There are five different manglings for characters:
3497     // - [a-zA-Z0-9_$]: A one-to-one mapping.
3498     // - ?[a-z]: The range from \xe1 to \xfa.
3499     // - ?[A-Z]: The range from \xc1 to \xda.
3500     // - ?[0-9]: The set of [,/\:. \n\t'-].
3501     // - ?$XX: A fallback which maps nibbles.
3502     if (isIdentifierBody(Byte, /*AllowDollar=*/true)) {
3503       Mangler.getStream() << Byte;
3504     } else if (isLetter(Byte & 0x7f)) {
3505       Mangler.getStream() << '?' << static_cast<char>(Byte & 0x7f);
3506     } else {
3507       const char SpecialChars[] = {',', '/',  '\\', ':',  '.',
3508                                    ' ', '\n', '\t', '\'', '-'};
3509       const char *Pos = llvm::find(SpecialChars, Byte);
3510       if (Pos != std::end(SpecialChars)) {
3511         Mangler.getStream() << '?' << (Pos - std::begin(SpecialChars));
3512       } else {
3513         Mangler.getStream() << "?$";
3514         Mangler.getStream() << static_cast<char>('A' + ((Byte >> 4) & 0xf));
3515         Mangler.getStream() << static_cast<char>('A' + (Byte & 0xf));
3516       }
3517     }
3518   };
3519 
3520   // Enforce our 32 bytes max, except wchar_t which gets 32 chars instead.
3521   unsigned MaxBytesToMangle = SL->isWide() ? 64U : 32U;
3522   unsigned NumBytesToMangle = std::min(MaxBytesToMangle, StringByteLength);
3523   for (unsigned I = 0; I != NumBytesToMangle; ++I) {
3524     if (SL->isWide())
3525       MangleByte(GetBigEndianByte(I));
3526     else
3527       MangleByte(GetLittleEndianByte(I));
3528   }
3529 
3530   Mangler.getStream() << '@';
3531 }
3532 
3533 MicrosoftMangleContext *
3534 MicrosoftMangleContext::create(ASTContext &Context, DiagnosticsEngine &Diags) {
3535   return new MicrosoftMangleContextImpl(Context, Diags);
3536 }
3537