ItaniumMangle.cpp revision 355940
1//===--- ItaniumMangle.cpp - Itanium C++ Name Mangling ----------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Implements C++ name mangling according to the Itanium C++ ABI,
10// which is used in GCC 3.2 and newer (and many compilers that are
11// ABI-compatible with GCC):
12//
13//   http://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangling
14//
15//===----------------------------------------------------------------------===//
16#include "clang/AST/Mangle.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/Attr.h"
19#include "clang/AST/Decl.h"
20#include "clang/AST/DeclCXX.h"
21#include "clang/AST/DeclObjC.h"
22#include "clang/AST/DeclOpenMP.h"
23#include "clang/AST/DeclTemplate.h"
24#include "clang/AST/Expr.h"
25#include "clang/AST/ExprCXX.h"
26#include "clang/AST/ExprObjC.h"
27#include "clang/AST/TypeLoc.h"
28#include "clang/Basic/ABI.h"
29#include "clang/Basic/SourceManager.h"
30#include "clang/Basic/TargetInfo.h"
31#include "llvm/ADT/StringExtras.h"
32#include "llvm/Support/ErrorHandling.h"
33#include "llvm/Support/raw_ostream.h"
34
35using namespace clang;
36
37namespace {
38
39/// Retrieve the declaration context that should be used when mangling the given
40/// declaration.
41static const DeclContext *getEffectiveDeclContext(const Decl *D) {
42  // The ABI assumes that lambda closure types that occur within
43  // default arguments live in the context of the function. However, due to
44  // the way in which Clang parses and creates function declarations, this is
45  // not the case: the lambda closure type ends up living in the context
46  // where the function itself resides, because the function declaration itself
47  // had not yet been created. Fix the context here.
48  if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
49    if (RD->isLambda())
50      if (ParmVarDecl *ContextParam
51            = dyn_cast_or_null<ParmVarDecl>(RD->getLambdaContextDecl()))
52        return ContextParam->getDeclContext();
53  }
54
55  // Perform the same check for block literals.
56  if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
57    if (ParmVarDecl *ContextParam
58          = dyn_cast_or_null<ParmVarDecl>(BD->getBlockManglingContextDecl()))
59      return ContextParam->getDeclContext();
60  }
61
62  const DeclContext *DC = D->getDeclContext();
63  if (isa<CapturedDecl>(DC) || isa<OMPDeclareReductionDecl>(DC) ||
64      isa<OMPDeclareMapperDecl>(DC)) {
65    return getEffectiveDeclContext(cast<Decl>(DC));
66  }
67
68  if (const auto *VD = dyn_cast<VarDecl>(D))
69    if (VD->isExternC())
70      return VD->getASTContext().getTranslationUnitDecl();
71
72  if (const auto *FD = dyn_cast<FunctionDecl>(D))
73    if (FD->isExternC())
74      return FD->getASTContext().getTranslationUnitDecl();
75
76  return DC->getRedeclContext();
77}
78
79static const DeclContext *getEffectiveParentContext(const DeclContext *DC) {
80  return getEffectiveDeclContext(cast<Decl>(DC));
81}
82
83static bool isLocalContainerContext(const DeclContext *DC) {
84  return isa<FunctionDecl>(DC) || isa<ObjCMethodDecl>(DC) || isa<BlockDecl>(DC);
85}
86
87static const RecordDecl *GetLocalClassDecl(const Decl *D) {
88  const DeclContext *DC = getEffectiveDeclContext(D);
89  while (!DC->isNamespace() && !DC->isTranslationUnit()) {
90    if (isLocalContainerContext(DC))
91      return dyn_cast<RecordDecl>(D);
92    D = cast<Decl>(DC);
93    DC = getEffectiveDeclContext(D);
94  }
95  return nullptr;
96}
97
98static const FunctionDecl *getStructor(const FunctionDecl *fn) {
99  if (const FunctionTemplateDecl *ftd = fn->getPrimaryTemplate())
100    return ftd->getTemplatedDecl();
101
102  return fn;
103}
104
105static const NamedDecl *getStructor(const NamedDecl *decl) {
106  const FunctionDecl *fn = dyn_cast_or_null<FunctionDecl>(decl);
107  return (fn ? getStructor(fn) : decl);
108}
109
110static bool isLambda(const NamedDecl *ND) {
111  const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(ND);
112  if (!Record)
113    return false;
114
115  return Record->isLambda();
116}
117
118static const unsigned UnknownArity = ~0U;
119
120class ItaniumMangleContextImpl : public ItaniumMangleContext {
121  typedef std::pair<const DeclContext*, IdentifierInfo*> DiscriminatorKeyTy;
122  llvm::DenseMap<DiscriminatorKeyTy, unsigned> Discriminator;
123  llvm::DenseMap<const NamedDecl*, unsigned> Uniquifier;
124
125public:
126  explicit ItaniumMangleContextImpl(ASTContext &Context,
127                                    DiagnosticsEngine &Diags)
128      : ItaniumMangleContext(Context, Diags) {}
129
130  /// @name Mangler Entry Points
131  /// @{
132
133  bool shouldMangleCXXName(const NamedDecl *D) override;
134  bool shouldMangleStringLiteral(const StringLiteral *) override {
135    return false;
136  }
137  void mangleCXXName(const NamedDecl *D, raw_ostream &) override;
138  void mangleThunk(const CXXMethodDecl *MD, const ThunkInfo &Thunk,
139                   raw_ostream &) override;
140  void mangleCXXDtorThunk(const CXXDestructorDecl *DD, CXXDtorType Type,
141                          const ThisAdjustment &ThisAdjustment,
142                          raw_ostream &) override;
143  void mangleReferenceTemporary(const VarDecl *D, unsigned ManglingNumber,
144                                raw_ostream &) override;
145  void mangleCXXVTable(const CXXRecordDecl *RD, raw_ostream &) override;
146  void mangleCXXVTT(const CXXRecordDecl *RD, raw_ostream &) override;
147  void mangleCXXCtorVTable(const CXXRecordDecl *RD, int64_t Offset,
148                           const CXXRecordDecl *Type, raw_ostream &) override;
149  void mangleCXXRTTI(QualType T, raw_ostream &) override;
150  void mangleCXXRTTIName(QualType T, raw_ostream &) override;
151  void mangleTypeName(QualType T, raw_ostream &) override;
152  void mangleCXXCtor(const CXXConstructorDecl *D, CXXCtorType Type,
153                     raw_ostream &) override;
154  void mangleCXXDtor(const CXXDestructorDecl *D, CXXDtorType Type,
155                     raw_ostream &) override;
156
157  void mangleCXXCtorComdat(const CXXConstructorDecl *D, raw_ostream &) override;
158  void mangleCXXDtorComdat(const CXXDestructorDecl *D, raw_ostream &) override;
159  void mangleStaticGuardVariable(const VarDecl *D, raw_ostream &) override;
160  void mangleDynamicInitializer(const VarDecl *D, raw_ostream &Out) override;
161  void mangleDynamicAtExitDestructor(const VarDecl *D,
162                                     raw_ostream &Out) override;
163  void mangleSEHFilterExpression(const NamedDecl *EnclosingDecl,
164                                 raw_ostream &Out) override;
165  void mangleSEHFinallyBlock(const NamedDecl *EnclosingDecl,
166                             raw_ostream &Out) override;
167  void mangleItaniumThreadLocalInit(const VarDecl *D, raw_ostream &) override;
168  void mangleItaniumThreadLocalWrapper(const VarDecl *D,
169                                       raw_ostream &) override;
170
171  void mangleStringLiteral(const StringLiteral *, raw_ostream &) override;
172
173  bool getNextDiscriminator(const NamedDecl *ND, unsigned &disc) {
174    // Lambda closure types are already numbered.
175    if (isLambda(ND))
176      return false;
177
178    // Anonymous tags are already numbered.
179    if (const TagDecl *Tag = dyn_cast<TagDecl>(ND)) {
180      if (Tag->getName().empty() && !Tag->getTypedefNameForAnonDecl())
181        return false;
182    }
183
184    // Use the canonical number for externally visible decls.
185    if (ND->isExternallyVisible()) {
186      unsigned discriminator = getASTContext().getManglingNumber(ND);
187      if (discriminator == 1)
188        return false;
189      disc = discriminator - 2;
190      return true;
191    }
192
193    // Make up a reasonable number for internal decls.
194    unsigned &discriminator = Uniquifier[ND];
195    if (!discriminator) {
196      const DeclContext *DC = getEffectiveDeclContext(ND);
197      discriminator = ++Discriminator[std::make_pair(DC, ND->getIdentifier())];
198    }
199    if (discriminator == 1)
200      return false;
201    disc = discriminator-2;
202    return true;
203  }
204  /// @}
205};
206
207/// Manage the mangling of a single name.
208class CXXNameMangler {
209  ItaniumMangleContextImpl &Context;
210  raw_ostream &Out;
211  bool NullOut = false;
212  /// In the "DisableDerivedAbiTags" mode derived ABI tags are not calculated.
213  /// This mode is used when mangler creates another mangler recursively to
214  /// calculate ABI tags for the function return value or the variable type.
215  /// Also it is required to avoid infinite recursion in some cases.
216  bool DisableDerivedAbiTags = false;
217
218  /// The "structor" is the top-level declaration being mangled, if
219  /// that's not a template specialization; otherwise it's the pattern
220  /// for that specialization.
221  const NamedDecl *Structor;
222  unsigned StructorType;
223
224  /// The next substitution sequence number.
225  unsigned SeqID;
226
227  class FunctionTypeDepthState {
228    unsigned Bits;
229
230    enum { InResultTypeMask = 1 };
231
232  public:
233    FunctionTypeDepthState() : Bits(0) {}
234
235    /// The number of function types we're inside.
236    unsigned getDepth() const {
237      return Bits >> 1;
238    }
239
240    /// True if we're in the return type of the innermost function type.
241    bool isInResultType() const {
242      return Bits & InResultTypeMask;
243    }
244
245    FunctionTypeDepthState push() {
246      FunctionTypeDepthState tmp = *this;
247      Bits = (Bits & ~InResultTypeMask) + 2;
248      return tmp;
249    }
250
251    void enterResultType() {
252      Bits |= InResultTypeMask;
253    }
254
255    void leaveResultType() {
256      Bits &= ~InResultTypeMask;
257    }
258
259    void pop(FunctionTypeDepthState saved) {
260      assert(getDepth() == saved.getDepth() + 1);
261      Bits = saved.Bits;
262    }
263
264  } FunctionTypeDepth;
265
266  // abi_tag is a gcc attribute, taking one or more strings called "tags".
267  // The goal is to annotate against which version of a library an object was
268  // built and to be able to provide backwards compatibility ("dual abi").
269  // For more information see docs/ItaniumMangleAbiTags.rst.
270  typedef SmallVector<StringRef, 4> AbiTagList;
271
272  // State to gather all implicit and explicit tags used in a mangled name.
273  // Must always have an instance of this while emitting any name to keep
274  // track.
275  class AbiTagState final {
276  public:
277    explicit AbiTagState(AbiTagState *&Head) : LinkHead(Head) {
278      Parent = LinkHead;
279      LinkHead = this;
280    }
281
282    // No copy, no move.
283    AbiTagState(const AbiTagState &) = delete;
284    AbiTagState &operator=(const AbiTagState &) = delete;
285
286    ~AbiTagState() { pop(); }
287
288    void write(raw_ostream &Out, const NamedDecl *ND,
289               const AbiTagList *AdditionalAbiTags) {
290      ND = cast<NamedDecl>(ND->getCanonicalDecl());
291      if (!isa<FunctionDecl>(ND) && !isa<VarDecl>(ND)) {
292        assert(
293            !AdditionalAbiTags &&
294            "only function and variables need a list of additional abi tags");
295        if (const auto *NS = dyn_cast<NamespaceDecl>(ND)) {
296          if (const auto *AbiTag = NS->getAttr<AbiTagAttr>()) {
297            UsedAbiTags.insert(UsedAbiTags.end(), AbiTag->tags().begin(),
298                               AbiTag->tags().end());
299          }
300          // Don't emit abi tags for namespaces.
301          return;
302        }
303      }
304
305      AbiTagList TagList;
306      if (const auto *AbiTag = ND->getAttr<AbiTagAttr>()) {
307        UsedAbiTags.insert(UsedAbiTags.end(), AbiTag->tags().begin(),
308                           AbiTag->tags().end());
309        TagList.insert(TagList.end(), AbiTag->tags().begin(),
310                       AbiTag->tags().end());
311      }
312
313      if (AdditionalAbiTags) {
314        UsedAbiTags.insert(UsedAbiTags.end(), AdditionalAbiTags->begin(),
315                           AdditionalAbiTags->end());
316        TagList.insert(TagList.end(), AdditionalAbiTags->begin(),
317                       AdditionalAbiTags->end());
318      }
319
320      llvm::sort(TagList);
321      TagList.erase(std::unique(TagList.begin(), TagList.end()), TagList.end());
322
323      writeSortedUniqueAbiTags(Out, TagList);
324    }
325
326    const AbiTagList &getUsedAbiTags() const { return UsedAbiTags; }
327    void setUsedAbiTags(const AbiTagList &AbiTags) {
328      UsedAbiTags = AbiTags;
329    }
330
331    const AbiTagList &getEmittedAbiTags() const {
332      return EmittedAbiTags;
333    }
334
335    const AbiTagList &getSortedUniqueUsedAbiTags() {
336      llvm::sort(UsedAbiTags);
337      UsedAbiTags.erase(std::unique(UsedAbiTags.begin(), UsedAbiTags.end()),
338                        UsedAbiTags.end());
339      return UsedAbiTags;
340    }
341
342  private:
343    //! All abi tags used implicitly or explicitly.
344    AbiTagList UsedAbiTags;
345    //! All explicit abi tags (i.e. not from namespace).
346    AbiTagList EmittedAbiTags;
347
348    AbiTagState *&LinkHead;
349    AbiTagState *Parent = nullptr;
350
351    void pop() {
352      assert(LinkHead == this &&
353             "abi tag link head must point to us on destruction");
354      if (Parent) {
355        Parent->UsedAbiTags.insert(Parent->UsedAbiTags.end(),
356                                   UsedAbiTags.begin(), UsedAbiTags.end());
357        Parent->EmittedAbiTags.insert(Parent->EmittedAbiTags.end(),
358                                      EmittedAbiTags.begin(),
359                                      EmittedAbiTags.end());
360      }
361      LinkHead = Parent;
362    }
363
364    void writeSortedUniqueAbiTags(raw_ostream &Out, const AbiTagList &AbiTags) {
365      for (const auto &Tag : AbiTags) {
366        EmittedAbiTags.push_back(Tag);
367        Out << "B";
368        Out << Tag.size();
369        Out << Tag;
370      }
371    }
372  };
373
374  AbiTagState *AbiTags = nullptr;
375  AbiTagState AbiTagsRoot;
376
377  llvm::DenseMap<uintptr_t, unsigned> Substitutions;
378  llvm::DenseMap<StringRef, unsigned> ModuleSubstitutions;
379
380  ASTContext &getASTContext() const { return Context.getASTContext(); }
381
382public:
383  CXXNameMangler(ItaniumMangleContextImpl &C, raw_ostream &Out_,
384                 const NamedDecl *D = nullptr, bool NullOut_ = false)
385    : Context(C), Out(Out_), NullOut(NullOut_),  Structor(getStructor(D)),
386      StructorType(0), SeqID(0), AbiTagsRoot(AbiTags) {
387    // These can't be mangled without a ctor type or dtor type.
388    assert(!D || (!isa<CXXDestructorDecl>(D) &&
389                  !isa<CXXConstructorDecl>(D)));
390  }
391  CXXNameMangler(ItaniumMangleContextImpl &C, raw_ostream &Out_,
392                 const CXXConstructorDecl *D, CXXCtorType Type)
393    : Context(C), Out(Out_), Structor(getStructor(D)), StructorType(Type),
394      SeqID(0), AbiTagsRoot(AbiTags) { }
395  CXXNameMangler(ItaniumMangleContextImpl &C, raw_ostream &Out_,
396                 const CXXDestructorDecl *D, CXXDtorType Type)
397    : Context(C), Out(Out_), Structor(getStructor(D)), StructorType(Type),
398      SeqID(0), AbiTagsRoot(AbiTags) { }
399
400  CXXNameMangler(CXXNameMangler &Outer, raw_ostream &Out_)
401      : Context(Outer.Context), Out(Out_), NullOut(false),
402        Structor(Outer.Structor), StructorType(Outer.StructorType),
403        SeqID(Outer.SeqID), FunctionTypeDepth(Outer.FunctionTypeDepth),
404        AbiTagsRoot(AbiTags), Substitutions(Outer.Substitutions) {}
405
406  CXXNameMangler(CXXNameMangler &Outer, llvm::raw_null_ostream &Out_)
407      : Context(Outer.Context), Out(Out_), NullOut(true),
408        Structor(Outer.Structor), StructorType(Outer.StructorType),
409        SeqID(Outer.SeqID), FunctionTypeDepth(Outer.FunctionTypeDepth),
410        AbiTagsRoot(AbiTags), Substitutions(Outer.Substitutions) {}
411
412  raw_ostream &getStream() { return Out; }
413
414  void disableDerivedAbiTags() { DisableDerivedAbiTags = true; }
415  static bool shouldHaveAbiTags(ItaniumMangleContextImpl &C, const VarDecl *VD);
416
417  void mangle(const NamedDecl *D);
418  void mangleCallOffset(int64_t NonVirtual, int64_t Virtual);
419  void mangleNumber(const llvm::APSInt &I);
420  void mangleNumber(int64_t Number);
421  void mangleFloat(const llvm::APFloat &F);
422  void mangleFunctionEncoding(const FunctionDecl *FD);
423  void mangleSeqID(unsigned SeqID);
424  void mangleName(const NamedDecl *ND);
425  void mangleType(QualType T);
426  void mangleNameOrStandardSubstitution(const NamedDecl *ND);
427
428private:
429
430  bool mangleSubstitution(const NamedDecl *ND);
431  bool mangleSubstitution(QualType T);
432  bool mangleSubstitution(TemplateName Template);
433  bool mangleSubstitution(uintptr_t Ptr);
434
435  void mangleExistingSubstitution(TemplateName name);
436
437  bool mangleStandardSubstitution(const NamedDecl *ND);
438
439  void addSubstitution(const NamedDecl *ND) {
440    ND = cast<NamedDecl>(ND->getCanonicalDecl());
441
442    addSubstitution(reinterpret_cast<uintptr_t>(ND));
443  }
444  void addSubstitution(QualType T);
445  void addSubstitution(TemplateName Template);
446  void addSubstitution(uintptr_t Ptr);
447  // Destructive copy substitutions from other mangler.
448  void extendSubstitutions(CXXNameMangler* Other);
449
450  void mangleUnresolvedPrefix(NestedNameSpecifier *qualifier,
451                              bool recursive = false);
452  void mangleUnresolvedName(NestedNameSpecifier *qualifier,
453                            DeclarationName name,
454                            const TemplateArgumentLoc *TemplateArgs,
455                            unsigned NumTemplateArgs,
456                            unsigned KnownArity = UnknownArity);
457
458  void mangleFunctionEncodingBareType(const FunctionDecl *FD);
459
460  void mangleNameWithAbiTags(const NamedDecl *ND,
461                             const AbiTagList *AdditionalAbiTags);
462  void mangleModuleName(const Module *M);
463  void mangleModuleNamePrefix(StringRef Name);
464  void mangleTemplateName(const TemplateDecl *TD,
465                          const TemplateArgument *TemplateArgs,
466                          unsigned NumTemplateArgs);
467  void mangleUnqualifiedName(const NamedDecl *ND,
468                             const AbiTagList *AdditionalAbiTags) {
469    mangleUnqualifiedName(ND, ND->getDeclName(), UnknownArity,
470                          AdditionalAbiTags);
471  }
472  void mangleUnqualifiedName(const NamedDecl *ND, DeclarationName Name,
473                             unsigned KnownArity,
474                             const AbiTagList *AdditionalAbiTags);
475  void mangleUnscopedName(const NamedDecl *ND,
476                          const AbiTagList *AdditionalAbiTags);
477  void mangleUnscopedTemplateName(const TemplateDecl *ND,
478                                  const AbiTagList *AdditionalAbiTags);
479  void mangleUnscopedTemplateName(TemplateName,
480                                  const AbiTagList *AdditionalAbiTags);
481  void mangleSourceName(const IdentifierInfo *II);
482  void mangleRegCallName(const IdentifierInfo *II);
483  void mangleSourceNameWithAbiTags(
484      const NamedDecl *ND, const AbiTagList *AdditionalAbiTags = nullptr);
485  void mangleLocalName(const Decl *D,
486                       const AbiTagList *AdditionalAbiTags);
487  void mangleBlockForPrefix(const BlockDecl *Block);
488  void mangleUnqualifiedBlock(const BlockDecl *Block);
489  void mangleTemplateParamDecl(const NamedDecl *Decl);
490  void mangleLambda(const CXXRecordDecl *Lambda);
491  void mangleNestedName(const NamedDecl *ND, const DeclContext *DC,
492                        const AbiTagList *AdditionalAbiTags,
493                        bool NoFunction=false);
494  void mangleNestedName(const TemplateDecl *TD,
495                        const TemplateArgument *TemplateArgs,
496                        unsigned NumTemplateArgs);
497  void manglePrefix(NestedNameSpecifier *qualifier);
498  void manglePrefix(const DeclContext *DC, bool NoFunction=false);
499  void manglePrefix(QualType type);
500  void mangleTemplatePrefix(const TemplateDecl *ND, bool NoFunction=false);
501  void mangleTemplatePrefix(TemplateName Template);
502  bool mangleUnresolvedTypeOrSimpleId(QualType DestroyedType,
503                                      StringRef Prefix = "");
504  void mangleOperatorName(DeclarationName Name, unsigned Arity);
505  void mangleOperatorName(OverloadedOperatorKind OO, unsigned Arity);
506  void mangleVendorQualifier(StringRef qualifier);
507  void mangleQualifiers(Qualifiers Quals, const DependentAddressSpaceType *DAST = nullptr);
508  void mangleRefQualifier(RefQualifierKind RefQualifier);
509
510  void mangleObjCMethodName(const ObjCMethodDecl *MD);
511
512  // Declare manglers for every type class.
513#define ABSTRACT_TYPE(CLASS, PARENT)
514#define NON_CANONICAL_TYPE(CLASS, PARENT)
515#define TYPE(CLASS, PARENT) void mangleType(const CLASS##Type *T);
516#include "clang/AST/TypeNodes.def"
517
518  void mangleType(const TagType*);
519  void mangleType(TemplateName);
520  static StringRef getCallingConvQualifierName(CallingConv CC);
521  void mangleExtParameterInfo(FunctionProtoType::ExtParameterInfo info);
522  void mangleExtFunctionInfo(const FunctionType *T);
523  void mangleBareFunctionType(const FunctionProtoType *T, bool MangleReturnType,
524                              const FunctionDecl *FD = nullptr);
525  void mangleNeonVectorType(const VectorType *T);
526  void mangleNeonVectorType(const DependentVectorType *T);
527  void mangleAArch64NeonVectorType(const VectorType *T);
528  void mangleAArch64NeonVectorType(const DependentVectorType *T);
529
530  void mangleIntegerLiteral(QualType T, const llvm::APSInt &Value);
531  void mangleMemberExprBase(const Expr *base, bool isArrow);
532  void mangleMemberExpr(const Expr *base, bool isArrow,
533                        NestedNameSpecifier *qualifier,
534                        NamedDecl *firstQualifierLookup,
535                        DeclarationName name,
536                        const TemplateArgumentLoc *TemplateArgs,
537                        unsigned NumTemplateArgs,
538                        unsigned knownArity);
539  void mangleCastExpression(const Expr *E, StringRef CastEncoding);
540  void mangleInitListElements(const InitListExpr *InitList);
541  void mangleDeclRefExpr(const NamedDecl *D);
542  void mangleExpression(const Expr *E, unsigned Arity = UnknownArity);
543  void mangleCXXCtorType(CXXCtorType T, const CXXRecordDecl *InheritedFrom);
544  void mangleCXXDtorType(CXXDtorType T);
545
546  void mangleTemplateArgs(const TemplateArgumentLoc *TemplateArgs,
547                          unsigned NumTemplateArgs);
548  void mangleTemplateArgs(const TemplateArgument *TemplateArgs,
549                          unsigned NumTemplateArgs);
550  void mangleTemplateArgs(const TemplateArgumentList &AL);
551  void mangleTemplateArg(TemplateArgument A);
552
553  void mangleTemplateParameter(unsigned Index);
554
555  void mangleFunctionParam(const ParmVarDecl *parm);
556
557  void writeAbiTags(const NamedDecl *ND,
558                    const AbiTagList *AdditionalAbiTags);
559
560  // Returns sorted unique list of ABI tags.
561  AbiTagList makeFunctionReturnTypeTags(const FunctionDecl *FD);
562  // Returns sorted unique list of ABI tags.
563  AbiTagList makeVariableTypeTags(const VarDecl *VD);
564};
565
566}
567
568bool ItaniumMangleContextImpl::shouldMangleCXXName(const NamedDecl *D) {
569  const FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
570  if (FD) {
571    LanguageLinkage L = FD->getLanguageLinkage();
572    // Overloadable functions need mangling.
573    if (FD->hasAttr<OverloadableAttr>())
574      return true;
575
576    // "main" is not mangled.
577    if (FD->isMain())
578      return false;
579
580    // The Windows ABI expects that we would never mangle "typical"
581    // user-defined entry points regardless of visibility or freestanding-ness.
582    //
583    // N.B. This is distinct from asking about "main".  "main" has a lot of
584    // special rules associated with it in the standard while these
585    // user-defined entry points are outside of the purview of the standard.
586    // For example, there can be only one definition for "main" in a standards
587    // compliant program; however nothing forbids the existence of wmain and
588    // WinMain in the same translation unit.
589    if (FD->isMSVCRTEntryPoint())
590      return false;
591
592    // C++ functions and those whose names are not a simple identifier need
593    // mangling.
594    if (!FD->getDeclName().isIdentifier() || L == CXXLanguageLinkage)
595      return true;
596
597    // C functions are not mangled.
598    if (L == CLanguageLinkage)
599      return false;
600  }
601
602  // Otherwise, no mangling is done outside C++ mode.
603  if (!getASTContext().getLangOpts().CPlusPlus)
604    return false;
605
606  const VarDecl *VD = dyn_cast<VarDecl>(D);
607  if (VD && !isa<DecompositionDecl>(D)) {
608    // C variables are not mangled.
609    if (VD->isExternC())
610      return false;
611
612    // Variables at global scope with non-internal linkage are not mangled
613    const DeclContext *DC = getEffectiveDeclContext(D);
614    // Check for extern variable declared locally.
615    if (DC->isFunctionOrMethod() && D->hasLinkage())
616      while (!DC->isNamespace() && !DC->isTranslationUnit())
617        DC = getEffectiveParentContext(DC);
618    if (DC->isTranslationUnit() && D->getFormalLinkage() != InternalLinkage &&
619        !CXXNameMangler::shouldHaveAbiTags(*this, VD) &&
620        !isa<VarTemplateSpecializationDecl>(D))
621      return false;
622  }
623
624  return true;
625}
626
627void CXXNameMangler::writeAbiTags(const NamedDecl *ND,
628                                  const AbiTagList *AdditionalAbiTags) {
629  assert(AbiTags && "require AbiTagState");
630  AbiTags->write(Out, ND, DisableDerivedAbiTags ? nullptr : AdditionalAbiTags);
631}
632
633void CXXNameMangler::mangleSourceNameWithAbiTags(
634    const NamedDecl *ND, const AbiTagList *AdditionalAbiTags) {
635  mangleSourceName(ND->getIdentifier());
636  writeAbiTags(ND, AdditionalAbiTags);
637}
638
639void CXXNameMangler::mangle(const NamedDecl *D) {
640  // <mangled-name> ::= _Z <encoding>
641  //            ::= <data name>
642  //            ::= <special-name>
643  Out << "_Z";
644  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
645    mangleFunctionEncoding(FD);
646  else if (const VarDecl *VD = dyn_cast<VarDecl>(D))
647    mangleName(VD);
648  else if (const IndirectFieldDecl *IFD = dyn_cast<IndirectFieldDecl>(D))
649    mangleName(IFD->getAnonField());
650  else
651    mangleName(cast<FieldDecl>(D));
652}
653
654void CXXNameMangler::mangleFunctionEncoding(const FunctionDecl *FD) {
655  // <encoding> ::= <function name> <bare-function-type>
656
657  // Don't mangle in the type if this isn't a decl we should typically mangle.
658  if (!Context.shouldMangleDeclName(FD)) {
659    mangleName(FD);
660    return;
661  }
662
663  AbiTagList ReturnTypeAbiTags = makeFunctionReturnTypeTags(FD);
664  if (ReturnTypeAbiTags.empty()) {
665    // There are no tags for return type, the simplest case.
666    mangleName(FD);
667    mangleFunctionEncodingBareType(FD);
668    return;
669  }
670
671  // Mangle function name and encoding to temporary buffer.
672  // We have to output name and encoding to the same mangler to get the same
673  // substitution as it will be in final mangling.
674  SmallString<256> FunctionEncodingBuf;
675  llvm::raw_svector_ostream FunctionEncodingStream(FunctionEncodingBuf);
676  CXXNameMangler FunctionEncodingMangler(*this, FunctionEncodingStream);
677  // Output name of the function.
678  FunctionEncodingMangler.disableDerivedAbiTags();
679  FunctionEncodingMangler.mangleNameWithAbiTags(FD, nullptr);
680
681  // Remember length of the function name in the buffer.
682  size_t EncodingPositionStart = FunctionEncodingStream.str().size();
683  FunctionEncodingMangler.mangleFunctionEncodingBareType(FD);
684
685  // Get tags from return type that are not present in function name or
686  // encoding.
687  const AbiTagList &UsedAbiTags =
688      FunctionEncodingMangler.AbiTagsRoot.getSortedUniqueUsedAbiTags();
689  AbiTagList AdditionalAbiTags(ReturnTypeAbiTags.size());
690  AdditionalAbiTags.erase(
691      std::set_difference(ReturnTypeAbiTags.begin(), ReturnTypeAbiTags.end(),
692                          UsedAbiTags.begin(), UsedAbiTags.end(),
693                          AdditionalAbiTags.begin()),
694      AdditionalAbiTags.end());
695
696  // Output name with implicit tags and function encoding from temporary buffer.
697  mangleNameWithAbiTags(FD, &AdditionalAbiTags);
698  Out << FunctionEncodingStream.str().substr(EncodingPositionStart);
699
700  // Function encoding could create new substitutions so we have to add
701  // temp mangled substitutions to main mangler.
702  extendSubstitutions(&FunctionEncodingMangler);
703}
704
705void CXXNameMangler::mangleFunctionEncodingBareType(const FunctionDecl *FD) {
706  if (FD->hasAttr<EnableIfAttr>()) {
707    FunctionTypeDepthState Saved = FunctionTypeDepth.push();
708    Out << "Ua9enable_ifI";
709    for (AttrVec::const_iterator I = FD->getAttrs().begin(),
710                                 E = FD->getAttrs().end();
711         I != E; ++I) {
712      EnableIfAttr *EIA = dyn_cast<EnableIfAttr>(*I);
713      if (!EIA)
714        continue;
715      Out << 'X';
716      mangleExpression(EIA->getCond());
717      Out << 'E';
718    }
719    Out << 'E';
720    FunctionTypeDepth.pop(Saved);
721  }
722
723  // When mangling an inheriting constructor, the bare function type used is
724  // that of the inherited constructor.
725  if (auto *CD = dyn_cast<CXXConstructorDecl>(FD))
726    if (auto Inherited = CD->getInheritedConstructor())
727      FD = Inherited.getConstructor();
728
729  // Whether the mangling of a function type includes the return type depends on
730  // the context and the nature of the function. The rules for deciding whether
731  // the return type is included are:
732  //
733  //   1. Template functions (names or types) have return types encoded, with
734  //   the exceptions listed below.
735  //   2. Function types not appearing as part of a function name mangling,
736  //   e.g. parameters, pointer types, etc., have return type encoded, with the
737  //   exceptions listed below.
738  //   3. Non-template function names do not have return types encoded.
739  //
740  // The exceptions mentioned in (1) and (2) above, for which the return type is
741  // never included, are
742  //   1. Constructors.
743  //   2. Destructors.
744  //   3. Conversion operator functions, e.g. operator int.
745  bool MangleReturnType = false;
746  if (FunctionTemplateDecl *PrimaryTemplate = FD->getPrimaryTemplate()) {
747    if (!(isa<CXXConstructorDecl>(FD) || isa<CXXDestructorDecl>(FD) ||
748          isa<CXXConversionDecl>(FD)))
749      MangleReturnType = true;
750
751    // Mangle the type of the primary template.
752    FD = PrimaryTemplate->getTemplatedDecl();
753  }
754
755  mangleBareFunctionType(FD->getType()->castAs<FunctionProtoType>(),
756                         MangleReturnType, FD);
757}
758
759static const DeclContext *IgnoreLinkageSpecDecls(const DeclContext *DC) {
760  while (isa<LinkageSpecDecl>(DC)) {
761    DC = getEffectiveParentContext(DC);
762  }
763
764  return DC;
765}
766
767/// Return whether a given namespace is the 'std' namespace.
768static bool isStd(const NamespaceDecl *NS) {
769  if (!IgnoreLinkageSpecDecls(getEffectiveParentContext(NS))
770                                ->isTranslationUnit())
771    return false;
772
773  const IdentifierInfo *II = NS->getOriginalNamespace()->getIdentifier();
774  return II && II->isStr("std");
775}
776
777// isStdNamespace - Return whether a given decl context is a toplevel 'std'
778// namespace.
779static bool isStdNamespace(const DeclContext *DC) {
780  if (!DC->isNamespace())
781    return false;
782
783  return isStd(cast<NamespaceDecl>(DC));
784}
785
786static const TemplateDecl *
787isTemplate(const NamedDecl *ND, const TemplateArgumentList *&TemplateArgs) {
788  // Check if we have a function template.
789  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
790    if (const TemplateDecl *TD = FD->getPrimaryTemplate()) {
791      TemplateArgs = FD->getTemplateSpecializationArgs();
792      return TD;
793    }
794  }
795
796  // Check if we have a class template.
797  if (const ClassTemplateSpecializationDecl *Spec =
798        dyn_cast<ClassTemplateSpecializationDecl>(ND)) {
799    TemplateArgs = &Spec->getTemplateArgs();
800    return Spec->getSpecializedTemplate();
801  }
802
803  // Check if we have a variable template.
804  if (const VarTemplateSpecializationDecl *Spec =
805          dyn_cast<VarTemplateSpecializationDecl>(ND)) {
806    TemplateArgs = &Spec->getTemplateArgs();
807    return Spec->getSpecializedTemplate();
808  }
809
810  return nullptr;
811}
812
813void CXXNameMangler::mangleName(const NamedDecl *ND) {
814  if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
815    // Variables should have implicit tags from its type.
816    AbiTagList VariableTypeAbiTags = makeVariableTypeTags(VD);
817    if (VariableTypeAbiTags.empty()) {
818      // Simple case no variable type tags.
819      mangleNameWithAbiTags(VD, nullptr);
820      return;
821    }
822
823    // Mangle variable name to null stream to collect tags.
824    llvm::raw_null_ostream NullOutStream;
825    CXXNameMangler VariableNameMangler(*this, NullOutStream);
826    VariableNameMangler.disableDerivedAbiTags();
827    VariableNameMangler.mangleNameWithAbiTags(VD, nullptr);
828
829    // Get tags from variable type that are not present in its name.
830    const AbiTagList &UsedAbiTags =
831        VariableNameMangler.AbiTagsRoot.getSortedUniqueUsedAbiTags();
832    AbiTagList AdditionalAbiTags(VariableTypeAbiTags.size());
833    AdditionalAbiTags.erase(
834        std::set_difference(VariableTypeAbiTags.begin(),
835                            VariableTypeAbiTags.end(), UsedAbiTags.begin(),
836                            UsedAbiTags.end(), AdditionalAbiTags.begin()),
837        AdditionalAbiTags.end());
838
839    // Output name with implicit tags.
840    mangleNameWithAbiTags(VD, &AdditionalAbiTags);
841  } else {
842    mangleNameWithAbiTags(ND, nullptr);
843  }
844}
845
846void CXXNameMangler::mangleNameWithAbiTags(const NamedDecl *ND,
847                                           const AbiTagList *AdditionalAbiTags) {
848  //  <name> ::= [<module-name>] <nested-name>
849  //         ::= [<module-name>] <unscoped-name>
850  //         ::= [<module-name>] <unscoped-template-name> <template-args>
851  //         ::= <local-name>
852  //
853  const DeclContext *DC = getEffectiveDeclContext(ND);
854
855  // If this is an extern variable declared locally, the relevant DeclContext
856  // is that of the containing namespace, or the translation unit.
857  // FIXME: This is a hack; extern variables declared locally should have
858  // a proper semantic declaration context!
859  if (isLocalContainerContext(DC) && ND->hasLinkage() && !isLambda(ND))
860    while (!DC->isNamespace() && !DC->isTranslationUnit())
861      DC = getEffectiveParentContext(DC);
862  else if (GetLocalClassDecl(ND)) {
863    mangleLocalName(ND, AdditionalAbiTags);
864    return;
865  }
866
867  DC = IgnoreLinkageSpecDecls(DC);
868
869  if (isLocalContainerContext(DC)) {
870    mangleLocalName(ND, AdditionalAbiTags);
871    return;
872  }
873
874  // Do not mangle the owning module for an external linkage declaration.
875  // This enables backwards-compatibility with non-modular code, and is
876  // a valid choice since conflicts are not permitted by C++ Modules TS
877  // [basic.def.odr]/6.2.
878  if (!ND->hasExternalFormalLinkage())
879    if (Module *M = ND->getOwningModuleForLinkage())
880      mangleModuleName(M);
881
882  if (DC->isTranslationUnit() || isStdNamespace(DC)) {
883    // Check if we have a template.
884    const TemplateArgumentList *TemplateArgs = nullptr;
885    if (const TemplateDecl *TD = isTemplate(ND, TemplateArgs)) {
886      mangleUnscopedTemplateName(TD, AdditionalAbiTags);
887      mangleTemplateArgs(*TemplateArgs);
888      return;
889    }
890
891    mangleUnscopedName(ND, AdditionalAbiTags);
892    return;
893  }
894
895  mangleNestedName(ND, DC, AdditionalAbiTags);
896}
897
898void CXXNameMangler::mangleModuleName(const Module *M) {
899  // Implement the C++ Modules TS name mangling proposal; see
900  //     https://gcc.gnu.org/wiki/cxx-modules?action=AttachFile
901  //
902  //   <module-name> ::= W <unscoped-name>+ E
903  //                 ::= W <module-subst> <unscoped-name>* E
904  Out << 'W';
905  mangleModuleNamePrefix(M->Name);
906  Out << 'E';
907}
908
909void CXXNameMangler::mangleModuleNamePrefix(StringRef Name) {
910  //  <module-subst> ::= _ <seq-id>          # 0 < seq-id < 10
911  //                 ::= W <seq-id - 10> _   # otherwise
912  auto It = ModuleSubstitutions.find(Name);
913  if (It != ModuleSubstitutions.end()) {
914    if (It->second < 10)
915      Out << '_' << static_cast<char>('0' + It->second);
916    else
917      Out << 'W' << (It->second - 10) << '_';
918    return;
919  }
920
921  // FIXME: Preserve hierarchy in module names rather than flattening
922  // them to strings; use Module*s as substitution keys.
923  auto Parts = Name.rsplit('.');
924  if (Parts.second.empty())
925    Parts.second = Parts.first;
926  else
927    mangleModuleNamePrefix(Parts.first);
928
929  Out << Parts.second.size() << Parts.second;
930  ModuleSubstitutions.insert({Name, ModuleSubstitutions.size()});
931}
932
933void CXXNameMangler::mangleTemplateName(const TemplateDecl *TD,
934                                        const TemplateArgument *TemplateArgs,
935                                        unsigned NumTemplateArgs) {
936  const DeclContext *DC = IgnoreLinkageSpecDecls(getEffectiveDeclContext(TD));
937
938  if (DC->isTranslationUnit() || isStdNamespace(DC)) {
939    mangleUnscopedTemplateName(TD, nullptr);
940    mangleTemplateArgs(TemplateArgs, NumTemplateArgs);
941  } else {
942    mangleNestedName(TD, TemplateArgs, NumTemplateArgs);
943  }
944}
945
946void CXXNameMangler::mangleUnscopedName(const NamedDecl *ND,
947                                        const AbiTagList *AdditionalAbiTags) {
948  //  <unscoped-name> ::= <unqualified-name>
949  //                  ::= St <unqualified-name>   # ::std::
950
951  if (isStdNamespace(IgnoreLinkageSpecDecls(getEffectiveDeclContext(ND))))
952    Out << "St";
953
954  mangleUnqualifiedName(ND, AdditionalAbiTags);
955}
956
957void CXXNameMangler::mangleUnscopedTemplateName(
958    const TemplateDecl *ND, const AbiTagList *AdditionalAbiTags) {
959  //     <unscoped-template-name> ::= <unscoped-name>
960  //                              ::= <substitution>
961  if (mangleSubstitution(ND))
962    return;
963
964  // <template-template-param> ::= <template-param>
965  if (const auto *TTP = dyn_cast<TemplateTemplateParmDecl>(ND)) {
966    assert(!AdditionalAbiTags &&
967           "template template param cannot have abi tags");
968    mangleTemplateParameter(TTP->getIndex());
969  } else if (isa<BuiltinTemplateDecl>(ND)) {
970    mangleUnscopedName(ND, AdditionalAbiTags);
971  } else {
972    mangleUnscopedName(ND->getTemplatedDecl(), AdditionalAbiTags);
973  }
974
975  addSubstitution(ND);
976}
977
978void CXXNameMangler::mangleUnscopedTemplateName(
979    TemplateName Template, const AbiTagList *AdditionalAbiTags) {
980  //     <unscoped-template-name> ::= <unscoped-name>
981  //                              ::= <substitution>
982  if (TemplateDecl *TD = Template.getAsTemplateDecl())
983    return mangleUnscopedTemplateName(TD, AdditionalAbiTags);
984
985  if (mangleSubstitution(Template))
986    return;
987
988  assert(!AdditionalAbiTags &&
989         "dependent template name cannot have abi tags");
990
991  DependentTemplateName *Dependent = Template.getAsDependentTemplateName();
992  assert(Dependent && "Not a dependent template name?");
993  if (const IdentifierInfo *Id = Dependent->getIdentifier())
994    mangleSourceName(Id);
995  else
996    mangleOperatorName(Dependent->getOperator(), UnknownArity);
997
998  addSubstitution(Template);
999}
1000
1001void CXXNameMangler::mangleFloat(const llvm::APFloat &f) {
1002  // ABI:
1003  //   Floating-point literals are encoded using a fixed-length
1004  //   lowercase hexadecimal string corresponding to the internal
1005  //   representation (IEEE on Itanium), high-order bytes first,
1006  //   without leading zeroes. For example: "Lf bf800000 E" is -1.0f
1007  //   on Itanium.
1008  // The 'without leading zeroes' thing seems to be an editorial
1009  // mistake; see the discussion on cxx-abi-dev beginning on
1010  // 2012-01-16.
1011
1012  // Our requirements here are just barely weird enough to justify
1013  // using a custom algorithm instead of post-processing APInt::toString().
1014
1015  llvm::APInt valueBits = f.bitcastToAPInt();
1016  unsigned numCharacters = (valueBits.getBitWidth() + 3) / 4;
1017  assert(numCharacters != 0);
1018
1019  // Allocate a buffer of the right number of characters.
1020  SmallVector<char, 20> buffer(numCharacters);
1021
1022  // Fill the buffer left-to-right.
1023  for (unsigned stringIndex = 0; stringIndex != numCharacters; ++stringIndex) {
1024    // The bit-index of the next hex digit.
1025    unsigned digitBitIndex = 4 * (numCharacters - stringIndex - 1);
1026
1027    // Project out 4 bits starting at 'digitIndex'.
1028    uint64_t hexDigit = valueBits.getRawData()[digitBitIndex / 64];
1029    hexDigit >>= (digitBitIndex % 64);
1030    hexDigit &= 0xF;
1031
1032    // Map that over to a lowercase hex digit.
1033    static const char charForHex[16] = {
1034      '0', '1', '2', '3', '4', '5', '6', '7',
1035      '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
1036    };
1037    buffer[stringIndex] = charForHex[hexDigit];
1038  }
1039
1040  Out.write(buffer.data(), numCharacters);
1041}
1042
1043void CXXNameMangler::mangleNumber(const llvm::APSInt &Value) {
1044  if (Value.isSigned() && Value.isNegative()) {
1045    Out << 'n';
1046    Value.abs().print(Out, /*signed*/ false);
1047  } else {
1048    Value.print(Out, /*signed*/ false);
1049  }
1050}
1051
1052void CXXNameMangler::mangleNumber(int64_t Number) {
1053  //  <number> ::= [n] <non-negative decimal integer>
1054  if (Number < 0) {
1055    Out << 'n';
1056    Number = -Number;
1057  }
1058
1059  Out << Number;
1060}
1061
1062void CXXNameMangler::mangleCallOffset(int64_t NonVirtual, int64_t Virtual) {
1063  //  <call-offset>  ::= h <nv-offset> _
1064  //                 ::= v <v-offset> _
1065  //  <nv-offset>    ::= <offset number>        # non-virtual base override
1066  //  <v-offset>     ::= <offset number> _ <virtual offset number>
1067  //                      # virtual base override, with vcall offset
1068  if (!Virtual) {
1069    Out << 'h';
1070    mangleNumber(NonVirtual);
1071    Out << '_';
1072    return;
1073  }
1074
1075  Out << 'v';
1076  mangleNumber(NonVirtual);
1077  Out << '_';
1078  mangleNumber(Virtual);
1079  Out << '_';
1080}
1081
1082void CXXNameMangler::manglePrefix(QualType type) {
1083  if (const auto *TST = type->getAs<TemplateSpecializationType>()) {
1084    if (!mangleSubstitution(QualType(TST, 0))) {
1085      mangleTemplatePrefix(TST->getTemplateName());
1086
1087      // FIXME: GCC does not appear to mangle the template arguments when
1088      // the template in question is a dependent template name. Should we
1089      // emulate that badness?
1090      mangleTemplateArgs(TST->getArgs(), TST->getNumArgs());
1091      addSubstitution(QualType(TST, 0));
1092    }
1093  } else if (const auto *DTST =
1094                 type->getAs<DependentTemplateSpecializationType>()) {
1095    if (!mangleSubstitution(QualType(DTST, 0))) {
1096      TemplateName Template = getASTContext().getDependentTemplateName(
1097          DTST->getQualifier(), DTST->getIdentifier());
1098      mangleTemplatePrefix(Template);
1099
1100      // FIXME: GCC does not appear to mangle the template arguments when
1101      // the template in question is a dependent template name. Should we
1102      // emulate that badness?
1103      mangleTemplateArgs(DTST->getArgs(), DTST->getNumArgs());
1104      addSubstitution(QualType(DTST, 0));
1105    }
1106  } else {
1107    // We use the QualType mangle type variant here because it handles
1108    // substitutions.
1109    mangleType(type);
1110  }
1111}
1112
1113/// Mangle everything prior to the base-unresolved-name in an unresolved-name.
1114///
1115/// \param recursive - true if this is being called recursively,
1116///   i.e. if there is more prefix "to the right".
1117void CXXNameMangler::mangleUnresolvedPrefix(NestedNameSpecifier *qualifier,
1118                                            bool recursive) {
1119
1120  // x, ::x
1121  // <unresolved-name> ::= [gs] <base-unresolved-name>
1122
1123  // T::x / decltype(p)::x
1124  // <unresolved-name> ::= sr <unresolved-type> <base-unresolved-name>
1125
1126  // T::N::x /decltype(p)::N::x
1127  // <unresolved-name> ::= srN <unresolved-type> <unresolved-qualifier-level>+ E
1128  //                       <base-unresolved-name>
1129
1130  // A::x, N::y, A<T>::z; "gs" means leading "::"
1131  // <unresolved-name> ::= [gs] sr <unresolved-qualifier-level>+ E
1132  //                       <base-unresolved-name>
1133
1134  switch (qualifier->getKind()) {
1135  case NestedNameSpecifier::Global:
1136    Out << "gs";
1137
1138    // We want an 'sr' unless this is the entire NNS.
1139    if (recursive)
1140      Out << "sr";
1141
1142    // We never want an 'E' here.
1143    return;
1144
1145  case NestedNameSpecifier::Super:
1146    llvm_unreachable("Can't mangle __super specifier");
1147
1148  case NestedNameSpecifier::Namespace:
1149    if (qualifier->getPrefix())
1150      mangleUnresolvedPrefix(qualifier->getPrefix(),
1151                             /*recursive*/ true);
1152    else
1153      Out << "sr";
1154    mangleSourceNameWithAbiTags(qualifier->getAsNamespace());
1155    break;
1156  case NestedNameSpecifier::NamespaceAlias:
1157    if (qualifier->getPrefix())
1158      mangleUnresolvedPrefix(qualifier->getPrefix(),
1159                             /*recursive*/ true);
1160    else
1161      Out << "sr";
1162    mangleSourceNameWithAbiTags(qualifier->getAsNamespaceAlias());
1163    break;
1164
1165  case NestedNameSpecifier::TypeSpec:
1166  case NestedNameSpecifier::TypeSpecWithTemplate: {
1167    const Type *type = qualifier->getAsType();
1168
1169    // We only want to use an unresolved-type encoding if this is one of:
1170    //   - a decltype
1171    //   - a template type parameter
1172    //   - a template template parameter with arguments
1173    // In all of these cases, we should have no prefix.
1174    if (qualifier->getPrefix()) {
1175      mangleUnresolvedPrefix(qualifier->getPrefix(),
1176                             /*recursive*/ true);
1177    } else {
1178      // Otherwise, all the cases want this.
1179      Out << "sr";
1180    }
1181
1182    if (mangleUnresolvedTypeOrSimpleId(QualType(type, 0), recursive ? "N" : ""))
1183      return;
1184
1185    break;
1186  }
1187
1188  case NestedNameSpecifier::Identifier:
1189    // Member expressions can have these without prefixes.
1190    if (qualifier->getPrefix())
1191      mangleUnresolvedPrefix(qualifier->getPrefix(),
1192                             /*recursive*/ true);
1193    else
1194      Out << "sr";
1195
1196    mangleSourceName(qualifier->getAsIdentifier());
1197    // An Identifier has no type information, so we can't emit abi tags for it.
1198    break;
1199  }
1200
1201  // If this was the innermost part of the NNS, and we fell out to
1202  // here, append an 'E'.
1203  if (!recursive)
1204    Out << 'E';
1205}
1206
1207/// Mangle an unresolved-name, which is generally used for names which
1208/// weren't resolved to specific entities.
1209void CXXNameMangler::mangleUnresolvedName(
1210    NestedNameSpecifier *qualifier, DeclarationName name,
1211    const TemplateArgumentLoc *TemplateArgs, unsigned NumTemplateArgs,
1212    unsigned knownArity) {
1213  if (qualifier) mangleUnresolvedPrefix(qualifier);
1214  switch (name.getNameKind()) {
1215    // <base-unresolved-name> ::= <simple-id>
1216    case DeclarationName::Identifier:
1217      mangleSourceName(name.getAsIdentifierInfo());
1218      break;
1219    // <base-unresolved-name> ::= dn <destructor-name>
1220    case DeclarationName::CXXDestructorName:
1221      Out << "dn";
1222      mangleUnresolvedTypeOrSimpleId(name.getCXXNameType());
1223      break;
1224    // <base-unresolved-name> ::= on <operator-name>
1225    case DeclarationName::CXXConversionFunctionName:
1226    case DeclarationName::CXXLiteralOperatorName:
1227    case DeclarationName::CXXOperatorName:
1228      Out << "on";
1229      mangleOperatorName(name, knownArity);
1230      break;
1231    case DeclarationName::CXXConstructorName:
1232      llvm_unreachable("Can't mangle a constructor name!");
1233    case DeclarationName::CXXUsingDirective:
1234      llvm_unreachable("Can't mangle a using directive name!");
1235    case DeclarationName::CXXDeductionGuideName:
1236      llvm_unreachable("Can't mangle a deduction guide name!");
1237    case DeclarationName::ObjCMultiArgSelector:
1238    case DeclarationName::ObjCOneArgSelector:
1239    case DeclarationName::ObjCZeroArgSelector:
1240      llvm_unreachable("Can't mangle Objective-C selector names here!");
1241  }
1242
1243  // The <simple-id> and on <operator-name> productions end in an optional
1244  // <template-args>.
1245  if (TemplateArgs)
1246    mangleTemplateArgs(TemplateArgs, NumTemplateArgs);
1247}
1248
1249void CXXNameMangler::mangleUnqualifiedName(const NamedDecl *ND,
1250                                           DeclarationName Name,
1251                                           unsigned KnownArity,
1252                                           const AbiTagList *AdditionalAbiTags) {
1253  unsigned Arity = KnownArity;
1254  //  <unqualified-name> ::= <operator-name>
1255  //                     ::= <ctor-dtor-name>
1256  //                     ::= <source-name>
1257  switch (Name.getNameKind()) {
1258  case DeclarationName::Identifier: {
1259    const IdentifierInfo *II = Name.getAsIdentifierInfo();
1260
1261    // We mangle decomposition declarations as the names of their bindings.
1262    if (auto *DD = dyn_cast<DecompositionDecl>(ND)) {
1263      // FIXME: Non-standard mangling for decomposition declarations:
1264      //
1265      //  <unqualified-name> ::= DC <source-name>* E
1266      //
1267      // These can never be referenced across translation units, so we do
1268      // not need a cross-vendor mangling for anything other than demanglers.
1269      // Proposed on cxx-abi-dev on 2016-08-12
1270      Out << "DC";
1271      for (auto *BD : DD->bindings())
1272        mangleSourceName(BD->getDeclName().getAsIdentifierInfo());
1273      Out << 'E';
1274      writeAbiTags(ND, AdditionalAbiTags);
1275      break;
1276    }
1277
1278    if (II) {
1279      // Match GCC's naming convention for internal linkage symbols, for
1280      // symbols that are not actually visible outside of this TU. GCC
1281      // distinguishes between internal and external linkage symbols in
1282      // its mangling, to support cases like this that were valid C++ prior
1283      // to DR426:
1284      //
1285      //   void test() { extern void foo(); }
1286      //   static void foo();
1287      //
1288      // Don't bother with the L marker for names in anonymous namespaces; the
1289      // 12_GLOBAL__N_1 mangling is quite sufficient there, and this better
1290      // matches GCC anyway, because GCC does not treat anonymous namespaces as
1291      // implying internal linkage.
1292      if (ND && ND->getFormalLinkage() == InternalLinkage &&
1293          !ND->isExternallyVisible() &&
1294          getEffectiveDeclContext(ND)->isFileContext() &&
1295          !ND->isInAnonymousNamespace())
1296        Out << 'L';
1297
1298      auto *FD = dyn_cast<FunctionDecl>(ND);
1299      bool IsRegCall = FD &&
1300                       FD->getType()->castAs<FunctionType>()->getCallConv() ==
1301                           clang::CC_X86RegCall;
1302      if (IsRegCall)
1303        mangleRegCallName(II);
1304      else
1305        mangleSourceName(II);
1306
1307      writeAbiTags(ND, AdditionalAbiTags);
1308      break;
1309    }
1310
1311    // Otherwise, an anonymous entity.  We must have a declaration.
1312    assert(ND && "mangling empty name without declaration");
1313
1314    if (const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(ND)) {
1315      if (NS->isAnonymousNamespace()) {
1316        // This is how gcc mangles these names.
1317        Out << "12_GLOBAL__N_1";
1318        break;
1319      }
1320    }
1321
1322    if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
1323      // We must have an anonymous union or struct declaration.
1324      const RecordDecl *RD = VD->getType()->getAs<RecordType>()->getDecl();
1325
1326      // Itanium C++ ABI 5.1.2:
1327      //
1328      //   For the purposes of mangling, the name of an anonymous union is
1329      //   considered to be the name of the first named data member found by a
1330      //   pre-order, depth-first, declaration-order walk of the data members of
1331      //   the anonymous union. If there is no such data member (i.e., if all of
1332      //   the data members in the union are unnamed), then there is no way for
1333      //   a program to refer to the anonymous union, and there is therefore no
1334      //   need to mangle its name.
1335      assert(RD->isAnonymousStructOrUnion()
1336             && "Expected anonymous struct or union!");
1337      const FieldDecl *FD = RD->findFirstNamedDataMember();
1338
1339      // It's actually possible for various reasons for us to get here
1340      // with an empty anonymous struct / union.  Fortunately, it
1341      // doesn't really matter what name we generate.
1342      if (!FD) break;
1343      assert(FD->getIdentifier() && "Data member name isn't an identifier!");
1344
1345      mangleSourceName(FD->getIdentifier());
1346      // Not emitting abi tags: internal name anyway.
1347      break;
1348    }
1349
1350    // Class extensions have no name as a category, and it's possible
1351    // for them to be the semantic parent of certain declarations
1352    // (primarily, tag decls defined within declarations).  Such
1353    // declarations will always have internal linkage, so the name
1354    // doesn't really matter, but we shouldn't crash on them.  For
1355    // safety, just handle all ObjC containers here.
1356    if (isa<ObjCContainerDecl>(ND))
1357      break;
1358
1359    // We must have an anonymous struct.
1360    const TagDecl *TD = cast<TagDecl>(ND);
1361    if (const TypedefNameDecl *D = TD->getTypedefNameForAnonDecl()) {
1362      assert(TD->getDeclContext() == D->getDeclContext() &&
1363             "Typedef should not be in another decl context!");
1364      assert(D->getDeclName().getAsIdentifierInfo() &&
1365             "Typedef was not named!");
1366      mangleSourceName(D->getDeclName().getAsIdentifierInfo());
1367      assert(!AdditionalAbiTags && "Type cannot have additional abi tags");
1368      // Explicit abi tags are still possible; take from underlying type, not
1369      // from typedef.
1370      writeAbiTags(TD, nullptr);
1371      break;
1372    }
1373
1374    // <unnamed-type-name> ::= <closure-type-name>
1375    //
1376    // <closure-type-name> ::= Ul <lambda-sig> E [ <nonnegative number> ] _
1377    // <lambda-sig> ::= <template-param-decl>* <parameter-type>+
1378    //     # Parameter types or 'v' for 'void'.
1379    if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(TD)) {
1380      if (Record->isLambda() && Record->getLambdaManglingNumber()) {
1381        assert(!AdditionalAbiTags &&
1382               "Lambda type cannot have additional abi tags");
1383        mangleLambda(Record);
1384        break;
1385      }
1386    }
1387
1388    if (TD->isExternallyVisible()) {
1389      unsigned UnnamedMangle = getASTContext().getManglingNumber(TD);
1390      Out << "Ut";
1391      if (UnnamedMangle > 1)
1392        Out << UnnamedMangle - 2;
1393      Out << '_';
1394      writeAbiTags(TD, AdditionalAbiTags);
1395      break;
1396    }
1397
1398    // Get a unique id for the anonymous struct. If it is not a real output
1399    // ID doesn't matter so use fake one.
1400    unsigned AnonStructId = NullOut ? 0 : Context.getAnonymousStructId(TD);
1401
1402    // Mangle it as a source name in the form
1403    // [n] $_<id>
1404    // where n is the length of the string.
1405    SmallString<8> Str;
1406    Str += "$_";
1407    Str += llvm::utostr(AnonStructId);
1408
1409    Out << Str.size();
1410    Out << Str;
1411    break;
1412  }
1413
1414  case DeclarationName::ObjCZeroArgSelector:
1415  case DeclarationName::ObjCOneArgSelector:
1416  case DeclarationName::ObjCMultiArgSelector:
1417    llvm_unreachable("Can't mangle Objective-C selector names here!");
1418
1419  case DeclarationName::CXXConstructorName: {
1420    const CXXRecordDecl *InheritedFrom = nullptr;
1421    const TemplateArgumentList *InheritedTemplateArgs = nullptr;
1422    if (auto Inherited =
1423            cast<CXXConstructorDecl>(ND)->getInheritedConstructor()) {
1424      InheritedFrom = Inherited.getConstructor()->getParent();
1425      InheritedTemplateArgs =
1426          Inherited.getConstructor()->getTemplateSpecializationArgs();
1427    }
1428
1429    if (ND == Structor)
1430      // If the named decl is the C++ constructor we're mangling, use the type
1431      // we were given.
1432      mangleCXXCtorType(static_cast<CXXCtorType>(StructorType), InheritedFrom);
1433    else
1434      // Otherwise, use the complete constructor name. This is relevant if a
1435      // class with a constructor is declared within a constructor.
1436      mangleCXXCtorType(Ctor_Complete, InheritedFrom);
1437
1438    // FIXME: The template arguments are part of the enclosing prefix or
1439    // nested-name, but it's more convenient to mangle them here.
1440    if (InheritedTemplateArgs)
1441      mangleTemplateArgs(*InheritedTemplateArgs);
1442
1443    writeAbiTags(ND, AdditionalAbiTags);
1444    break;
1445  }
1446
1447  case DeclarationName::CXXDestructorName:
1448    if (ND == Structor)
1449      // If the named decl is the C++ destructor we're mangling, use the type we
1450      // were given.
1451      mangleCXXDtorType(static_cast<CXXDtorType>(StructorType));
1452    else
1453      // Otherwise, use the complete destructor name. This is relevant if a
1454      // class with a destructor is declared within a destructor.
1455      mangleCXXDtorType(Dtor_Complete);
1456    writeAbiTags(ND, AdditionalAbiTags);
1457    break;
1458
1459  case DeclarationName::CXXOperatorName:
1460    if (ND && Arity == UnknownArity) {
1461      Arity = cast<FunctionDecl>(ND)->getNumParams();
1462
1463      // If we have a member function, we need to include the 'this' pointer.
1464      if (const auto *MD = dyn_cast<CXXMethodDecl>(ND))
1465        if (!MD->isStatic())
1466          Arity++;
1467    }
1468    LLVM_FALLTHROUGH;
1469  case DeclarationName::CXXConversionFunctionName:
1470  case DeclarationName::CXXLiteralOperatorName:
1471    mangleOperatorName(Name, Arity);
1472    writeAbiTags(ND, AdditionalAbiTags);
1473    break;
1474
1475  case DeclarationName::CXXDeductionGuideName:
1476    llvm_unreachable("Can't mangle a deduction guide name!");
1477
1478  case DeclarationName::CXXUsingDirective:
1479    llvm_unreachable("Can't mangle a using directive name!");
1480  }
1481}
1482
1483void CXXNameMangler::mangleRegCallName(const IdentifierInfo *II) {
1484  // <source-name> ::= <positive length number> __regcall3__ <identifier>
1485  // <number> ::= [n] <non-negative decimal integer>
1486  // <identifier> ::= <unqualified source code identifier>
1487  Out << II->getLength() + sizeof("__regcall3__") - 1 << "__regcall3__"
1488      << II->getName();
1489}
1490
1491void CXXNameMangler::mangleSourceName(const IdentifierInfo *II) {
1492  // <source-name> ::= <positive length number> <identifier>
1493  // <number> ::= [n] <non-negative decimal integer>
1494  // <identifier> ::= <unqualified source code identifier>
1495  Out << II->getLength() << II->getName();
1496}
1497
1498void CXXNameMangler::mangleNestedName(const NamedDecl *ND,
1499                                      const DeclContext *DC,
1500                                      const AbiTagList *AdditionalAbiTags,
1501                                      bool NoFunction) {
1502  // <nested-name>
1503  //   ::= N [<CV-qualifiers>] [<ref-qualifier>] <prefix> <unqualified-name> E
1504  //   ::= N [<CV-qualifiers>] [<ref-qualifier>] <template-prefix>
1505  //       <template-args> E
1506
1507  Out << 'N';
1508  if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(ND)) {
1509    Qualifiers MethodQuals = Method->getMethodQualifiers();
1510    // We do not consider restrict a distinguishing attribute for overloading
1511    // purposes so we must not mangle it.
1512    MethodQuals.removeRestrict();
1513    mangleQualifiers(MethodQuals);
1514    mangleRefQualifier(Method->getRefQualifier());
1515  }
1516
1517  // Check if we have a template.
1518  const TemplateArgumentList *TemplateArgs = nullptr;
1519  if (const TemplateDecl *TD = isTemplate(ND, TemplateArgs)) {
1520    mangleTemplatePrefix(TD, NoFunction);
1521    mangleTemplateArgs(*TemplateArgs);
1522  }
1523  else {
1524    manglePrefix(DC, NoFunction);
1525    mangleUnqualifiedName(ND, AdditionalAbiTags);
1526  }
1527
1528  Out << 'E';
1529}
1530void CXXNameMangler::mangleNestedName(const TemplateDecl *TD,
1531                                      const TemplateArgument *TemplateArgs,
1532                                      unsigned NumTemplateArgs) {
1533  // <nested-name> ::= N [<CV-qualifiers>] <template-prefix> <template-args> E
1534
1535  Out << 'N';
1536
1537  mangleTemplatePrefix(TD);
1538  mangleTemplateArgs(TemplateArgs, NumTemplateArgs);
1539
1540  Out << 'E';
1541}
1542
1543void CXXNameMangler::mangleLocalName(const Decl *D,
1544                                     const AbiTagList *AdditionalAbiTags) {
1545  // <local-name> := Z <function encoding> E <entity name> [<discriminator>]
1546  //              := Z <function encoding> E s [<discriminator>]
1547  // <local-name> := Z <function encoding> E d [ <parameter number> ]
1548  //                 _ <entity name>
1549  // <discriminator> := _ <non-negative number>
1550  assert(isa<NamedDecl>(D) || isa<BlockDecl>(D));
1551  const RecordDecl *RD = GetLocalClassDecl(D);
1552  const DeclContext *DC = getEffectiveDeclContext(RD ? RD : D);
1553
1554  Out << 'Z';
1555
1556  {
1557    AbiTagState LocalAbiTags(AbiTags);
1558
1559    if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(DC))
1560      mangleObjCMethodName(MD);
1561    else if (const BlockDecl *BD = dyn_cast<BlockDecl>(DC))
1562      mangleBlockForPrefix(BD);
1563    else
1564      mangleFunctionEncoding(cast<FunctionDecl>(DC));
1565
1566    // Implicit ABI tags (from namespace) are not available in the following
1567    // entity; reset to actually emitted tags, which are available.
1568    LocalAbiTags.setUsedAbiTags(LocalAbiTags.getEmittedAbiTags());
1569  }
1570
1571  Out << 'E';
1572
1573  // GCC 5.3.0 doesn't emit derived ABI tags for local names but that seems to
1574  // be a bug that is fixed in trunk.
1575
1576  if (RD) {
1577    // The parameter number is omitted for the last parameter, 0 for the
1578    // second-to-last parameter, 1 for the third-to-last parameter, etc. The
1579    // <entity name> will of course contain a <closure-type-name>: Its
1580    // numbering will be local to the particular argument in which it appears
1581    // -- other default arguments do not affect its encoding.
1582    const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(RD);
1583    if (CXXRD && CXXRD->isLambda()) {
1584      if (const ParmVarDecl *Parm
1585              = dyn_cast_or_null<ParmVarDecl>(CXXRD->getLambdaContextDecl())) {
1586        if (const FunctionDecl *Func
1587              = dyn_cast<FunctionDecl>(Parm->getDeclContext())) {
1588          Out << 'd';
1589          unsigned Num = Func->getNumParams() - Parm->getFunctionScopeIndex();
1590          if (Num > 1)
1591            mangleNumber(Num - 2);
1592          Out << '_';
1593        }
1594      }
1595    }
1596
1597    // Mangle the name relative to the closest enclosing function.
1598    // equality ok because RD derived from ND above
1599    if (D == RD)  {
1600      mangleUnqualifiedName(RD, AdditionalAbiTags);
1601    } else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
1602      manglePrefix(getEffectiveDeclContext(BD), true /*NoFunction*/);
1603      assert(!AdditionalAbiTags && "Block cannot have additional abi tags");
1604      mangleUnqualifiedBlock(BD);
1605    } else {
1606      const NamedDecl *ND = cast<NamedDecl>(D);
1607      mangleNestedName(ND, getEffectiveDeclContext(ND), AdditionalAbiTags,
1608                       true /*NoFunction*/);
1609    }
1610  } else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
1611    // Mangle a block in a default parameter; see above explanation for
1612    // lambdas.
1613    if (const ParmVarDecl *Parm
1614            = dyn_cast_or_null<ParmVarDecl>(BD->getBlockManglingContextDecl())) {
1615      if (const FunctionDecl *Func
1616            = dyn_cast<FunctionDecl>(Parm->getDeclContext())) {
1617        Out << 'd';
1618        unsigned Num = Func->getNumParams() - Parm->getFunctionScopeIndex();
1619        if (Num > 1)
1620          mangleNumber(Num - 2);
1621        Out << '_';
1622      }
1623    }
1624
1625    assert(!AdditionalAbiTags && "Block cannot have additional abi tags");
1626    mangleUnqualifiedBlock(BD);
1627  } else {
1628    mangleUnqualifiedName(cast<NamedDecl>(D), AdditionalAbiTags);
1629  }
1630
1631  if (const NamedDecl *ND = dyn_cast<NamedDecl>(RD ? RD : D)) {
1632    unsigned disc;
1633    if (Context.getNextDiscriminator(ND, disc)) {
1634      if (disc < 10)
1635        Out << '_' << disc;
1636      else
1637        Out << "__" << disc << '_';
1638    }
1639  }
1640}
1641
1642void CXXNameMangler::mangleBlockForPrefix(const BlockDecl *Block) {
1643  if (GetLocalClassDecl(Block)) {
1644    mangleLocalName(Block, /* AdditionalAbiTags */ nullptr);
1645    return;
1646  }
1647  const DeclContext *DC = getEffectiveDeclContext(Block);
1648  if (isLocalContainerContext(DC)) {
1649    mangleLocalName(Block, /* AdditionalAbiTags */ nullptr);
1650    return;
1651  }
1652  manglePrefix(getEffectiveDeclContext(Block));
1653  mangleUnqualifiedBlock(Block);
1654}
1655
1656void CXXNameMangler::mangleUnqualifiedBlock(const BlockDecl *Block) {
1657  if (Decl *Context = Block->getBlockManglingContextDecl()) {
1658    if ((isa<VarDecl>(Context) || isa<FieldDecl>(Context)) &&
1659        Context->getDeclContext()->isRecord()) {
1660      const auto *ND = cast<NamedDecl>(Context);
1661      if (ND->getIdentifier()) {
1662        mangleSourceNameWithAbiTags(ND);
1663        Out << 'M';
1664      }
1665    }
1666  }
1667
1668  // If we have a block mangling number, use it.
1669  unsigned Number = Block->getBlockManglingNumber();
1670  // Otherwise, just make up a number. It doesn't matter what it is because
1671  // the symbol in question isn't externally visible.
1672  if (!Number)
1673    Number = Context.getBlockId(Block, false);
1674  else {
1675    // Stored mangling numbers are 1-based.
1676    --Number;
1677  }
1678  Out << "Ub";
1679  if (Number > 0)
1680    Out << Number - 1;
1681  Out << '_';
1682}
1683
1684// <template-param-decl>
1685//   ::= Ty                              # template type parameter
1686//   ::= Tn <type>                       # template non-type parameter
1687//   ::= Tt <template-param-decl>* E     # template template parameter
1688void CXXNameMangler::mangleTemplateParamDecl(const NamedDecl *Decl) {
1689  if (isa<TemplateTypeParmDecl>(Decl)) {
1690    Out << "Ty";
1691  } else if (auto *Tn = dyn_cast<NonTypeTemplateParmDecl>(Decl)) {
1692    Out << "Tn";
1693    mangleType(Tn->getType());
1694  } else if (auto *Tt = dyn_cast<TemplateTemplateParmDecl>(Decl)) {
1695    Out << "Tt";
1696    for (auto *Param : *Tt->getTemplateParameters())
1697      mangleTemplateParamDecl(Param);
1698    Out << "E";
1699  }
1700}
1701
1702void CXXNameMangler::mangleLambda(const CXXRecordDecl *Lambda) {
1703  // If the context of a closure type is an initializer for a class member
1704  // (static or nonstatic), it is encoded in a qualified name with a final
1705  // <prefix> of the form:
1706  //
1707  //   <data-member-prefix> := <member source-name> M
1708  //
1709  // Technically, the data-member-prefix is part of the <prefix>. However,
1710  // since a closure type will always be mangled with a prefix, it's easier
1711  // to emit that last part of the prefix here.
1712  if (Decl *Context = Lambda->getLambdaContextDecl()) {
1713    if ((isa<VarDecl>(Context) || isa<FieldDecl>(Context)) &&
1714        !isa<ParmVarDecl>(Context)) {
1715      // FIXME: 'inline auto [a, b] = []{ return ... };' does not get a
1716      // reasonable mangling here.
1717      if (const IdentifierInfo *Name
1718            = cast<NamedDecl>(Context)->getIdentifier()) {
1719        mangleSourceName(Name);
1720        const TemplateArgumentList *TemplateArgs = nullptr;
1721        if (isTemplate(cast<NamedDecl>(Context), TemplateArgs))
1722          mangleTemplateArgs(*TemplateArgs);
1723        Out << 'M';
1724      }
1725    }
1726  }
1727
1728  Out << "Ul";
1729  for (auto *D : Lambda->getLambdaExplicitTemplateParameters())
1730    mangleTemplateParamDecl(D);
1731  const FunctionProtoType *Proto = Lambda->getLambdaTypeInfo()->getType()->
1732                                   getAs<FunctionProtoType>();
1733  mangleBareFunctionType(Proto, /*MangleReturnType=*/false,
1734                         Lambda->getLambdaStaticInvoker());
1735  Out << "E";
1736
1737  // The number is omitted for the first closure type with a given
1738  // <lambda-sig> in a given context; it is n-2 for the nth closure type
1739  // (in lexical order) with that same <lambda-sig> and context.
1740  //
1741  // The AST keeps track of the number for us.
1742  unsigned Number = Lambda->getLambdaManglingNumber();
1743  assert(Number > 0 && "Lambda should be mangled as an unnamed class");
1744  if (Number > 1)
1745    mangleNumber(Number - 2);
1746  Out << '_';
1747}
1748
1749void CXXNameMangler::manglePrefix(NestedNameSpecifier *qualifier) {
1750  switch (qualifier->getKind()) {
1751  case NestedNameSpecifier::Global:
1752    // nothing
1753    return;
1754
1755  case NestedNameSpecifier::Super:
1756    llvm_unreachable("Can't mangle __super specifier");
1757
1758  case NestedNameSpecifier::Namespace:
1759    mangleName(qualifier->getAsNamespace());
1760    return;
1761
1762  case NestedNameSpecifier::NamespaceAlias:
1763    mangleName(qualifier->getAsNamespaceAlias()->getNamespace());
1764    return;
1765
1766  case NestedNameSpecifier::TypeSpec:
1767  case NestedNameSpecifier::TypeSpecWithTemplate:
1768    manglePrefix(QualType(qualifier->getAsType(), 0));
1769    return;
1770
1771  case NestedNameSpecifier::Identifier:
1772    // Member expressions can have these without prefixes, but that
1773    // should end up in mangleUnresolvedPrefix instead.
1774    assert(qualifier->getPrefix());
1775    manglePrefix(qualifier->getPrefix());
1776
1777    mangleSourceName(qualifier->getAsIdentifier());
1778    return;
1779  }
1780
1781  llvm_unreachable("unexpected nested name specifier");
1782}
1783
1784void CXXNameMangler::manglePrefix(const DeclContext *DC, bool NoFunction) {
1785  //  <prefix> ::= <prefix> <unqualified-name>
1786  //           ::= <template-prefix> <template-args>
1787  //           ::= <template-param>
1788  //           ::= # empty
1789  //           ::= <substitution>
1790
1791  DC = IgnoreLinkageSpecDecls(DC);
1792
1793  if (DC->isTranslationUnit())
1794    return;
1795
1796  if (NoFunction && isLocalContainerContext(DC))
1797    return;
1798
1799  assert(!isLocalContainerContext(DC));
1800
1801  const NamedDecl *ND = cast<NamedDecl>(DC);
1802  if (mangleSubstitution(ND))
1803    return;
1804
1805  // Check if we have a template.
1806  const TemplateArgumentList *TemplateArgs = nullptr;
1807  if (const TemplateDecl *TD = isTemplate(ND, TemplateArgs)) {
1808    mangleTemplatePrefix(TD);
1809    mangleTemplateArgs(*TemplateArgs);
1810  } else {
1811    manglePrefix(getEffectiveDeclContext(ND), NoFunction);
1812    mangleUnqualifiedName(ND, nullptr);
1813  }
1814
1815  addSubstitution(ND);
1816}
1817
1818void CXXNameMangler::mangleTemplatePrefix(TemplateName Template) {
1819  // <template-prefix> ::= <prefix> <template unqualified-name>
1820  //                   ::= <template-param>
1821  //                   ::= <substitution>
1822  if (TemplateDecl *TD = Template.getAsTemplateDecl())
1823    return mangleTemplatePrefix(TD);
1824
1825  if (QualifiedTemplateName *Qualified = Template.getAsQualifiedTemplateName())
1826    manglePrefix(Qualified->getQualifier());
1827
1828  if (OverloadedTemplateStorage *Overloaded
1829                                      = Template.getAsOverloadedTemplate()) {
1830    mangleUnqualifiedName(nullptr, (*Overloaded->begin())->getDeclName(),
1831                          UnknownArity, nullptr);
1832    return;
1833  }
1834
1835  DependentTemplateName *Dependent = Template.getAsDependentTemplateName();
1836  assert(Dependent && "Unknown template name kind?");
1837  if (NestedNameSpecifier *Qualifier = Dependent->getQualifier())
1838    manglePrefix(Qualifier);
1839  mangleUnscopedTemplateName(Template, /* AdditionalAbiTags */ nullptr);
1840}
1841
1842void CXXNameMangler::mangleTemplatePrefix(const TemplateDecl *ND,
1843                                          bool NoFunction) {
1844  // <template-prefix> ::= <prefix> <template unqualified-name>
1845  //                   ::= <template-param>
1846  //                   ::= <substitution>
1847  // <template-template-param> ::= <template-param>
1848  //                               <substitution>
1849
1850  if (mangleSubstitution(ND))
1851    return;
1852
1853  // <template-template-param> ::= <template-param>
1854  if (const auto *TTP = dyn_cast<TemplateTemplateParmDecl>(ND)) {
1855    mangleTemplateParameter(TTP->getIndex());
1856  } else {
1857    manglePrefix(getEffectiveDeclContext(ND), NoFunction);
1858    if (isa<BuiltinTemplateDecl>(ND))
1859      mangleUnqualifiedName(ND, nullptr);
1860    else
1861      mangleUnqualifiedName(ND->getTemplatedDecl(), nullptr);
1862  }
1863
1864  addSubstitution(ND);
1865}
1866
1867/// Mangles a template name under the production <type>.  Required for
1868/// template template arguments.
1869///   <type> ::= <class-enum-type>
1870///          ::= <template-param>
1871///          ::= <substitution>
1872void CXXNameMangler::mangleType(TemplateName TN) {
1873  if (mangleSubstitution(TN))
1874    return;
1875
1876  TemplateDecl *TD = nullptr;
1877
1878  switch (TN.getKind()) {
1879  case TemplateName::QualifiedTemplate:
1880    TD = TN.getAsQualifiedTemplateName()->getTemplateDecl();
1881    goto HaveDecl;
1882
1883  case TemplateName::Template:
1884    TD = TN.getAsTemplateDecl();
1885    goto HaveDecl;
1886
1887  HaveDecl:
1888    if (isa<TemplateTemplateParmDecl>(TD))
1889      mangleTemplateParameter(cast<TemplateTemplateParmDecl>(TD)->getIndex());
1890    else
1891      mangleName(TD);
1892    break;
1893
1894  case TemplateName::OverloadedTemplate:
1895  case TemplateName::AssumedTemplate:
1896    llvm_unreachable("can't mangle an overloaded template name as a <type>");
1897
1898  case TemplateName::DependentTemplate: {
1899    const DependentTemplateName *Dependent = TN.getAsDependentTemplateName();
1900    assert(Dependent->isIdentifier());
1901
1902    // <class-enum-type> ::= <name>
1903    // <name> ::= <nested-name>
1904    mangleUnresolvedPrefix(Dependent->getQualifier());
1905    mangleSourceName(Dependent->getIdentifier());
1906    break;
1907  }
1908
1909  case TemplateName::SubstTemplateTemplateParm: {
1910    // Substituted template parameters are mangled as the substituted
1911    // template.  This will check for the substitution twice, which is
1912    // fine, but we have to return early so that we don't try to *add*
1913    // the substitution twice.
1914    SubstTemplateTemplateParmStorage *subst
1915      = TN.getAsSubstTemplateTemplateParm();
1916    mangleType(subst->getReplacement());
1917    return;
1918  }
1919
1920  case TemplateName::SubstTemplateTemplateParmPack: {
1921    // FIXME: not clear how to mangle this!
1922    // template <template <class> class T...> class A {
1923    //   template <template <class> class U...> void foo(B<T,U> x...);
1924    // };
1925    Out << "_SUBSTPACK_";
1926    break;
1927  }
1928  }
1929
1930  addSubstitution(TN);
1931}
1932
1933bool CXXNameMangler::mangleUnresolvedTypeOrSimpleId(QualType Ty,
1934                                                    StringRef Prefix) {
1935  // Only certain other types are valid as prefixes;  enumerate them.
1936  switch (Ty->getTypeClass()) {
1937  case Type::Builtin:
1938  case Type::Complex:
1939  case Type::Adjusted:
1940  case Type::Decayed:
1941  case Type::Pointer:
1942  case Type::BlockPointer:
1943  case Type::LValueReference:
1944  case Type::RValueReference:
1945  case Type::MemberPointer:
1946  case Type::ConstantArray:
1947  case Type::IncompleteArray:
1948  case Type::VariableArray:
1949  case Type::DependentSizedArray:
1950  case Type::DependentAddressSpace:
1951  case Type::DependentVector:
1952  case Type::DependentSizedExtVector:
1953  case Type::Vector:
1954  case Type::ExtVector:
1955  case Type::FunctionProto:
1956  case Type::FunctionNoProto:
1957  case Type::Paren:
1958  case Type::Attributed:
1959  case Type::Auto:
1960  case Type::DeducedTemplateSpecialization:
1961  case Type::PackExpansion:
1962  case Type::ObjCObject:
1963  case Type::ObjCInterface:
1964  case Type::ObjCObjectPointer:
1965  case Type::ObjCTypeParam:
1966  case Type::Atomic:
1967  case Type::Pipe:
1968  case Type::MacroQualified:
1969    llvm_unreachable("type is illegal as a nested name specifier");
1970
1971  case Type::SubstTemplateTypeParmPack:
1972    // FIXME: not clear how to mangle this!
1973    // template <class T...> class A {
1974    //   template <class U...> void foo(decltype(T::foo(U())) x...);
1975    // };
1976    Out << "_SUBSTPACK_";
1977    break;
1978
1979  // <unresolved-type> ::= <template-param>
1980  //                   ::= <decltype>
1981  //                   ::= <template-template-param> <template-args>
1982  // (this last is not official yet)
1983  case Type::TypeOfExpr:
1984  case Type::TypeOf:
1985  case Type::Decltype:
1986  case Type::TemplateTypeParm:
1987  case Type::UnaryTransform:
1988  case Type::SubstTemplateTypeParm:
1989  unresolvedType:
1990    // Some callers want a prefix before the mangled type.
1991    Out << Prefix;
1992
1993    // This seems to do everything we want.  It's not really
1994    // sanctioned for a substituted template parameter, though.
1995    mangleType(Ty);
1996
1997    // We never want to print 'E' directly after an unresolved-type,
1998    // so we return directly.
1999    return true;
2000
2001  case Type::Typedef:
2002    mangleSourceNameWithAbiTags(cast<TypedefType>(Ty)->getDecl());
2003    break;
2004
2005  case Type::UnresolvedUsing:
2006    mangleSourceNameWithAbiTags(
2007        cast<UnresolvedUsingType>(Ty)->getDecl());
2008    break;
2009
2010  case Type::Enum:
2011  case Type::Record:
2012    mangleSourceNameWithAbiTags(cast<TagType>(Ty)->getDecl());
2013    break;
2014
2015  case Type::TemplateSpecialization: {
2016    const TemplateSpecializationType *TST =
2017        cast<TemplateSpecializationType>(Ty);
2018    TemplateName TN = TST->getTemplateName();
2019    switch (TN.getKind()) {
2020    case TemplateName::Template:
2021    case TemplateName::QualifiedTemplate: {
2022      TemplateDecl *TD = TN.getAsTemplateDecl();
2023
2024      // If the base is a template template parameter, this is an
2025      // unresolved type.
2026      assert(TD && "no template for template specialization type");
2027      if (isa<TemplateTemplateParmDecl>(TD))
2028        goto unresolvedType;
2029
2030      mangleSourceNameWithAbiTags(TD);
2031      break;
2032    }
2033
2034    case TemplateName::OverloadedTemplate:
2035    case TemplateName::AssumedTemplate:
2036    case TemplateName::DependentTemplate:
2037      llvm_unreachable("invalid base for a template specialization type");
2038
2039    case TemplateName::SubstTemplateTemplateParm: {
2040      SubstTemplateTemplateParmStorage *subst =
2041          TN.getAsSubstTemplateTemplateParm();
2042      mangleExistingSubstitution(subst->getReplacement());
2043      break;
2044    }
2045
2046    case TemplateName::SubstTemplateTemplateParmPack: {
2047      // FIXME: not clear how to mangle this!
2048      // template <template <class U> class T...> class A {
2049      //   template <class U...> void foo(decltype(T<U>::foo) x...);
2050      // };
2051      Out << "_SUBSTPACK_";
2052      break;
2053    }
2054    }
2055
2056    mangleTemplateArgs(TST->getArgs(), TST->getNumArgs());
2057    break;
2058  }
2059
2060  case Type::InjectedClassName:
2061    mangleSourceNameWithAbiTags(
2062        cast<InjectedClassNameType>(Ty)->getDecl());
2063    break;
2064
2065  case Type::DependentName:
2066    mangleSourceName(cast<DependentNameType>(Ty)->getIdentifier());
2067    break;
2068
2069  case Type::DependentTemplateSpecialization: {
2070    const DependentTemplateSpecializationType *DTST =
2071        cast<DependentTemplateSpecializationType>(Ty);
2072    mangleSourceName(DTST->getIdentifier());
2073    mangleTemplateArgs(DTST->getArgs(), DTST->getNumArgs());
2074    break;
2075  }
2076
2077  case Type::Elaborated:
2078    return mangleUnresolvedTypeOrSimpleId(
2079        cast<ElaboratedType>(Ty)->getNamedType(), Prefix);
2080  }
2081
2082  return false;
2083}
2084
2085void CXXNameMangler::mangleOperatorName(DeclarationName Name, unsigned Arity) {
2086  switch (Name.getNameKind()) {
2087  case DeclarationName::CXXConstructorName:
2088  case DeclarationName::CXXDestructorName:
2089  case DeclarationName::CXXDeductionGuideName:
2090  case DeclarationName::CXXUsingDirective:
2091  case DeclarationName::Identifier:
2092  case DeclarationName::ObjCMultiArgSelector:
2093  case DeclarationName::ObjCOneArgSelector:
2094  case DeclarationName::ObjCZeroArgSelector:
2095    llvm_unreachable("Not an operator name");
2096
2097  case DeclarationName::CXXConversionFunctionName:
2098    // <operator-name> ::= cv <type>    # (cast)
2099    Out << "cv";
2100    mangleType(Name.getCXXNameType());
2101    break;
2102
2103  case DeclarationName::CXXLiteralOperatorName:
2104    Out << "li";
2105    mangleSourceName(Name.getCXXLiteralIdentifier());
2106    return;
2107
2108  case DeclarationName::CXXOperatorName:
2109    mangleOperatorName(Name.getCXXOverloadedOperator(), Arity);
2110    break;
2111  }
2112}
2113
2114void
2115CXXNameMangler::mangleOperatorName(OverloadedOperatorKind OO, unsigned Arity) {
2116  switch (OO) {
2117  // <operator-name> ::= nw     # new
2118  case OO_New: Out << "nw"; break;
2119  //              ::= na        # new[]
2120  case OO_Array_New: Out << "na"; break;
2121  //              ::= dl        # delete
2122  case OO_Delete: Out << "dl"; break;
2123  //              ::= da        # delete[]
2124  case OO_Array_Delete: Out << "da"; break;
2125  //              ::= ps        # + (unary)
2126  //              ::= pl        # + (binary or unknown)
2127  case OO_Plus:
2128    Out << (Arity == 1? "ps" : "pl"); break;
2129  //              ::= ng        # - (unary)
2130  //              ::= mi        # - (binary or unknown)
2131  case OO_Minus:
2132    Out << (Arity == 1? "ng" : "mi"); break;
2133  //              ::= ad        # & (unary)
2134  //              ::= an        # & (binary or unknown)
2135  case OO_Amp:
2136    Out << (Arity == 1? "ad" : "an"); break;
2137  //              ::= de        # * (unary)
2138  //              ::= ml        # * (binary or unknown)
2139  case OO_Star:
2140    // Use binary when unknown.
2141    Out << (Arity == 1? "de" : "ml"); break;
2142  //              ::= co        # ~
2143  case OO_Tilde: Out << "co"; break;
2144  //              ::= dv        # /
2145  case OO_Slash: Out << "dv"; break;
2146  //              ::= rm        # %
2147  case OO_Percent: Out << "rm"; break;
2148  //              ::= or        # |
2149  case OO_Pipe: Out << "or"; break;
2150  //              ::= eo        # ^
2151  case OO_Caret: Out << "eo"; break;
2152  //              ::= aS        # =
2153  case OO_Equal: Out << "aS"; break;
2154  //              ::= pL        # +=
2155  case OO_PlusEqual: Out << "pL"; break;
2156  //              ::= mI        # -=
2157  case OO_MinusEqual: Out << "mI"; break;
2158  //              ::= mL        # *=
2159  case OO_StarEqual: Out << "mL"; break;
2160  //              ::= dV        # /=
2161  case OO_SlashEqual: Out << "dV"; break;
2162  //              ::= rM        # %=
2163  case OO_PercentEqual: Out << "rM"; break;
2164  //              ::= aN        # &=
2165  case OO_AmpEqual: Out << "aN"; break;
2166  //              ::= oR        # |=
2167  case OO_PipeEqual: Out << "oR"; break;
2168  //              ::= eO        # ^=
2169  case OO_CaretEqual: Out << "eO"; break;
2170  //              ::= ls        # <<
2171  case OO_LessLess: Out << "ls"; break;
2172  //              ::= rs        # >>
2173  case OO_GreaterGreater: Out << "rs"; break;
2174  //              ::= lS        # <<=
2175  case OO_LessLessEqual: Out << "lS"; break;
2176  //              ::= rS        # >>=
2177  case OO_GreaterGreaterEqual: Out << "rS"; break;
2178  //              ::= eq        # ==
2179  case OO_EqualEqual: Out << "eq"; break;
2180  //              ::= ne        # !=
2181  case OO_ExclaimEqual: Out << "ne"; break;
2182  //              ::= lt        # <
2183  case OO_Less: Out << "lt"; break;
2184  //              ::= gt        # >
2185  case OO_Greater: Out << "gt"; break;
2186  //              ::= le        # <=
2187  case OO_LessEqual: Out << "le"; break;
2188  //              ::= ge        # >=
2189  case OO_GreaterEqual: Out << "ge"; break;
2190  //              ::= nt        # !
2191  case OO_Exclaim: Out << "nt"; break;
2192  //              ::= aa        # &&
2193  case OO_AmpAmp: Out << "aa"; break;
2194  //              ::= oo        # ||
2195  case OO_PipePipe: Out << "oo"; break;
2196  //              ::= pp        # ++
2197  case OO_PlusPlus: Out << "pp"; break;
2198  //              ::= mm        # --
2199  case OO_MinusMinus: Out << "mm"; break;
2200  //              ::= cm        # ,
2201  case OO_Comma: Out << "cm"; break;
2202  //              ::= pm        # ->*
2203  case OO_ArrowStar: Out << "pm"; break;
2204  //              ::= pt        # ->
2205  case OO_Arrow: Out << "pt"; break;
2206  //              ::= cl        # ()
2207  case OO_Call: Out << "cl"; break;
2208  //              ::= ix        # []
2209  case OO_Subscript: Out << "ix"; break;
2210
2211  //              ::= qu        # ?
2212  // The conditional operator can't be overloaded, but we still handle it when
2213  // mangling expressions.
2214  case OO_Conditional: Out << "qu"; break;
2215  // Proposal on cxx-abi-dev, 2015-10-21.
2216  //              ::= aw        # co_await
2217  case OO_Coawait: Out << "aw"; break;
2218  // Proposed in cxx-abi github issue 43.
2219  //              ::= ss        # <=>
2220  case OO_Spaceship: Out << "ss"; break;
2221
2222  case OO_None:
2223  case NUM_OVERLOADED_OPERATORS:
2224    llvm_unreachable("Not an overloaded operator");
2225  }
2226}
2227
2228void CXXNameMangler::mangleQualifiers(Qualifiers Quals, const DependentAddressSpaceType *DAST) {
2229  // Vendor qualifiers come first and if they are order-insensitive they must
2230  // be emitted in reversed alphabetical order, see Itanium ABI 5.1.5.
2231
2232  // <type> ::= U <addrspace-expr>
2233  if (DAST) {
2234    Out << "U2ASI";
2235    mangleExpression(DAST->getAddrSpaceExpr());
2236    Out << "E";
2237  }
2238
2239  // Address space qualifiers start with an ordinary letter.
2240  if (Quals.hasAddressSpace()) {
2241    // Address space extension:
2242    //
2243    //   <type> ::= U <target-addrspace>
2244    //   <type> ::= U <OpenCL-addrspace>
2245    //   <type> ::= U <CUDA-addrspace>
2246
2247    SmallString<64> ASString;
2248    LangAS AS = Quals.getAddressSpace();
2249
2250    if (Context.getASTContext().addressSpaceMapManglingFor(AS)) {
2251      //  <target-addrspace> ::= "AS" <address-space-number>
2252      unsigned TargetAS = Context.getASTContext().getTargetAddressSpace(AS);
2253      if (TargetAS != 0)
2254        ASString = "AS" + llvm::utostr(TargetAS);
2255    } else {
2256      switch (AS) {
2257      default: llvm_unreachable("Not a language specific address space");
2258      //  <OpenCL-addrspace> ::= "CL" [ "global" | "local" | "constant" |
2259      //                                "private"| "generic" ]
2260      case LangAS::opencl_global:   ASString = "CLglobal";   break;
2261      case LangAS::opencl_local:    ASString = "CLlocal";    break;
2262      case LangAS::opencl_constant: ASString = "CLconstant"; break;
2263      case LangAS::opencl_private:  ASString = "CLprivate";  break;
2264      case LangAS::opencl_generic:  ASString = "CLgeneric";  break;
2265      //  <CUDA-addrspace> ::= "CU" [ "device" | "constant" | "shared" ]
2266      case LangAS::cuda_device:     ASString = "CUdevice";   break;
2267      case LangAS::cuda_constant:   ASString = "CUconstant"; break;
2268      case LangAS::cuda_shared:     ASString = "CUshared";   break;
2269      }
2270    }
2271    if (!ASString.empty())
2272      mangleVendorQualifier(ASString);
2273  }
2274
2275  // The ARC ownership qualifiers start with underscores.
2276  // Objective-C ARC Extension:
2277  //
2278  //   <type> ::= U "__strong"
2279  //   <type> ::= U "__weak"
2280  //   <type> ::= U "__autoreleasing"
2281  //
2282  // Note: we emit __weak first to preserve the order as
2283  // required by the Itanium ABI.
2284  if (Quals.getObjCLifetime() == Qualifiers::OCL_Weak)
2285    mangleVendorQualifier("__weak");
2286
2287  // __unaligned (from -fms-extensions)
2288  if (Quals.hasUnaligned())
2289    mangleVendorQualifier("__unaligned");
2290
2291  // Remaining ARC ownership qualifiers.
2292  switch (Quals.getObjCLifetime()) {
2293  case Qualifiers::OCL_None:
2294    break;
2295
2296  case Qualifiers::OCL_Weak:
2297    // Do nothing as we already handled this case above.
2298    break;
2299
2300  case Qualifiers::OCL_Strong:
2301    mangleVendorQualifier("__strong");
2302    break;
2303
2304  case Qualifiers::OCL_Autoreleasing:
2305    mangleVendorQualifier("__autoreleasing");
2306    break;
2307
2308  case Qualifiers::OCL_ExplicitNone:
2309    // The __unsafe_unretained qualifier is *not* mangled, so that
2310    // __unsafe_unretained types in ARC produce the same manglings as the
2311    // equivalent (but, naturally, unqualified) types in non-ARC, providing
2312    // better ABI compatibility.
2313    //
2314    // It's safe to do this because unqualified 'id' won't show up
2315    // in any type signatures that need to be mangled.
2316    break;
2317  }
2318
2319  // <CV-qualifiers> ::= [r] [V] [K]    # restrict (C99), volatile, const
2320  if (Quals.hasRestrict())
2321    Out << 'r';
2322  if (Quals.hasVolatile())
2323    Out << 'V';
2324  if (Quals.hasConst())
2325    Out << 'K';
2326}
2327
2328void CXXNameMangler::mangleVendorQualifier(StringRef name) {
2329  Out << 'U' << name.size() << name;
2330}
2331
2332void CXXNameMangler::mangleRefQualifier(RefQualifierKind RefQualifier) {
2333  // <ref-qualifier> ::= R                # lvalue reference
2334  //                 ::= O                # rvalue-reference
2335  switch (RefQualifier) {
2336  case RQ_None:
2337    break;
2338
2339  case RQ_LValue:
2340    Out << 'R';
2341    break;
2342
2343  case RQ_RValue:
2344    Out << 'O';
2345    break;
2346  }
2347}
2348
2349void CXXNameMangler::mangleObjCMethodName(const ObjCMethodDecl *MD) {
2350  Context.mangleObjCMethodName(MD, Out);
2351}
2352
2353static bool isTypeSubstitutable(Qualifiers Quals, const Type *Ty,
2354                                ASTContext &Ctx) {
2355  if (Quals)
2356    return true;
2357  if (Ty->isSpecificBuiltinType(BuiltinType::ObjCSel))
2358    return true;
2359  if (Ty->isOpenCLSpecificType())
2360    return true;
2361  if (Ty->isBuiltinType())
2362    return false;
2363  // Through to Clang 6.0, we accidentally treated undeduced auto types as
2364  // substitution candidates.
2365  if (Ctx.getLangOpts().getClangABICompat() > LangOptions::ClangABI::Ver6 &&
2366      isa<AutoType>(Ty))
2367    return false;
2368  return true;
2369}
2370
2371void CXXNameMangler::mangleType(QualType T) {
2372  // If our type is instantiation-dependent but not dependent, we mangle
2373  // it as it was written in the source, removing any top-level sugar.
2374  // Otherwise, use the canonical type.
2375  //
2376  // FIXME: This is an approximation of the instantiation-dependent name
2377  // mangling rules, since we should really be using the type as written and
2378  // augmented via semantic analysis (i.e., with implicit conversions and
2379  // default template arguments) for any instantiation-dependent type.
2380  // Unfortunately, that requires several changes to our AST:
2381  //   - Instantiation-dependent TemplateSpecializationTypes will need to be
2382  //     uniqued, so that we can handle substitutions properly
2383  //   - Default template arguments will need to be represented in the
2384  //     TemplateSpecializationType, since they need to be mangled even though
2385  //     they aren't written.
2386  //   - Conversions on non-type template arguments need to be expressed, since
2387  //     they can affect the mangling of sizeof/alignof.
2388  //
2389  // FIXME: This is wrong when mapping to the canonical type for a dependent
2390  // type discards instantiation-dependent portions of the type, such as for:
2391  //
2392  //   template<typename T, int N> void f(T (&)[sizeof(N)]);
2393  //   template<typename T> void f(T() throw(typename T::type)); (pre-C++17)
2394  //
2395  // It's also wrong in the opposite direction when instantiation-dependent,
2396  // canonically-equivalent types differ in some irrelevant portion of inner
2397  // type sugar. In such cases, we fail to form correct substitutions, eg:
2398  //
2399  //   template<int N> void f(A<sizeof(N)> *, A<sizeof(N)> (*));
2400  //
2401  // We should instead canonicalize the non-instantiation-dependent parts,
2402  // regardless of whether the type as a whole is dependent or instantiation
2403  // dependent.
2404  if (!T->isInstantiationDependentType() || T->isDependentType())
2405    T = T.getCanonicalType();
2406  else {
2407    // Desugar any types that are purely sugar.
2408    do {
2409      // Don't desugar through template specialization types that aren't
2410      // type aliases. We need to mangle the template arguments as written.
2411      if (const TemplateSpecializationType *TST
2412                                      = dyn_cast<TemplateSpecializationType>(T))
2413        if (!TST->isTypeAlias())
2414          break;
2415
2416      QualType Desugared
2417        = T.getSingleStepDesugaredType(Context.getASTContext());
2418      if (Desugared == T)
2419        break;
2420
2421      T = Desugared;
2422    } while (true);
2423  }
2424  SplitQualType split = T.split();
2425  Qualifiers quals = split.Quals;
2426  const Type *ty = split.Ty;
2427
2428  bool isSubstitutable =
2429    isTypeSubstitutable(quals, ty, Context.getASTContext());
2430  if (isSubstitutable && mangleSubstitution(T))
2431    return;
2432
2433  // If we're mangling a qualified array type, push the qualifiers to
2434  // the element type.
2435  if (quals && isa<ArrayType>(T)) {
2436    ty = Context.getASTContext().getAsArrayType(T);
2437    quals = Qualifiers();
2438
2439    // Note that we don't update T: we want to add the
2440    // substitution at the original type.
2441  }
2442
2443  if (quals || ty->isDependentAddressSpaceType()) {
2444    if (const DependentAddressSpaceType *DAST =
2445        dyn_cast<DependentAddressSpaceType>(ty)) {
2446      SplitQualType splitDAST = DAST->getPointeeType().split();
2447      mangleQualifiers(splitDAST.Quals, DAST);
2448      mangleType(QualType(splitDAST.Ty, 0));
2449    } else {
2450      mangleQualifiers(quals);
2451
2452      // Recurse:  even if the qualified type isn't yet substitutable,
2453      // the unqualified type might be.
2454      mangleType(QualType(ty, 0));
2455    }
2456  } else {
2457    switch (ty->getTypeClass()) {
2458#define ABSTRACT_TYPE(CLASS, PARENT)
2459#define NON_CANONICAL_TYPE(CLASS, PARENT) \
2460    case Type::CLASS: \
2461      llvm_unreachable("can't mangle non-canonical type " #CLASS "Type"); \
2462      return;
2463#define TYPE(CLASS, PARENT) \
2464    case Type::CLASS: \
2465      mangleType(static_cast<const CLASS##Type*>(ty)); \
2466      break;
2467#include "clang/AST/TypeNodes.def"
2468    }
2469  }
2470
2471  // Add the substitution.
2472  if (isSubstitutable)
2473    addSubstitution(T);
2474}
2475
2476void CXXNameMangler::mangleNameOrStandardSubstitution(const NamedDecl *ND) {
2477  if (!mangleStandardSubstitution(ND))
2478    mangleName(ND);
2479}
2480
2481void CXXNameMangler::mangleType(const BuiltinType *T) {
2482  //  <type>         ::= <builtin-type>
2483  //  <builtin-type> ::= v  # void
2484  //                 ::= w  # wchar_t
2485  //                 ::= b  # bool
2486  //                 ::= c  # char
2487  //                 ::= a  # signed char
2488  //                 ::= h  # unsigned char
2489  //                 ::= s  # short
2490  //                 ::= t  # unsigned short
2491  //                 ::= i  # int
2492  //                 ::= j  # unsigned int
2493  //                 ::= l  # long
2494  //                 ::= m  # unsigned long
2495  //                 ::= x  # long long, __int64
2496  //                 ::= y  # unsigned long long, __int64
2497  //                 ::= n  # __int128
2498  //                 ::= o  # unsigned __int128
2499  //                 ::= f  # float
2500  //                 ::= d  # double
2501  //                 ::= e  # long double, __float80
2502  //                 ::= g  # __float128
2503  // UNSUPPORTED:    ::= Dd # IEEE 754r decimal floating point (64 bits)
2504  // UNSUPPORTED:    ::= De # IEEE 754r decimal floating point (128 bits)
2505  // UNSUPPORTED:    ::= Df # IEEE 754r decimal floating point (32 bits)
2506  //                 ::= Dh # IEEE 754r half-precision floating point (16 bits)
2507  //                 ::= DF <number> _ # ISO/IEC TS 18661 binary floating point type _FloatN (N bits);
2508  //                 ::= Di # char32_t
2509  //                 ::= Ds # char16_t
2510  //                 ::= Dn # std::nullptr_t (i.e., decltype(nullptr))
2511  //                 ::= u <source-name>    # vendor extended type
2512  std::string type_name;
2513  switch (T->getKind()) {
2514  case BuiltinType::Void:
2515    Out << 'v';
2516    break;
2517  case BuiltinType::Bool:
2518    Out << 'b';
2519    break;
2520  case BuiltinType::Char_U:
2521  case BuiltinType::Char_S:
2522    Out << 'c';
2523    break;
2524  case BuiltinType::UChar:
2525    Out << 'h';
2526    break;
2527  case BuiltinType::UShort:
2528    Out << 't';
2529    break;
2530  case BuiltinType::UInt:
2531    Out << 'j';
2532    break;
2533  case BuiltinType::ULong:
2534    Out << 'm';
2535    break;
2536  case BuiltinType::ULongLong:
2537    Out << 'y';
2538    break;
2539  case BuiltinType::UInt128:
2540    Out << 'o';
2541    break;
2542  case BuiltinType::SChar:
2543    Out << 'a';
2544    break;
2545  case BuiltinType::WChar_S:
2546  case BuiltinType::WChar_U:
2547    Out << 'w';
2548    break;
2549  case BuiltinType::Char8:
2550    Out << "Du";
2551    break;
2552  case BuiltinType::Char16:
2553    Out << "Ds";
2554    break;
2555  case BuiltinType::Char32:
2556    Out << "Di";
2557    break;
2558  case BuiltinType::Short:
2559    Out << 's';
2560    break;
2561  case BuiltinType::Int:
2562    Out << 'i';
2563    break;
2564  case BuiltinType::Long:
2565    Out << 'l';
2566    break;
2567  case BuiltinType::LongLong:
2568    Out << 'x';
2569    break;
2570  case BuiltinType::Int128:
2571    Out << 'n';
2572    break;
2573  case BuiltinType::Float16:
2574    Out << "DF16_";
2575    break;
2576  case BuiltinType::ShortAccum:
2577  case BuiltinType::Accum:
2578  case BuiltinType::LongAccum:
2579  case BuiltinType::UShortAccum:
2580  case BuiltinType::UAccum:
2581  case BuiltinType::ULongAccum:
2582  case BuiltinType::ShortFract:
2583  case BuiltinType::Fract:
2584  case BuiltinType::LongFract:
2585  case BuiltinType::UShortFract:
2586  case BuiltinType::UFract:
2587  case BuiltinType::ULongFract:
2588  case BuiltinType::SatShortAccum:
2589  case BuiltinType::SatAccum:
2590  case BuiltinType::SatLongAccum:
2591  case BuiltinType::SatUShortAccum:
2592  case BuiltinType::SatUAccum:
2593  case BuiltinType::SatULongAccum:
2594  case BuiltinType::SatShortFract:
2595  case BuiltinType::SatFract:
2596  case BuiltinType::SatLongFract:
2597  case BuiltinType::SatUShortFract:
2598  case BuiltinType::SatUFract:
2599  case BuiltinType::SatULongFract:
2600    llvm_unreachable("Fixed point types are disabled for c++");
2601  case BuiltinType::Half:
2602    Out << "Dh";
2603    break;
2604  case BuiltinType::Float:
2605    Out << 'f';
2606    break;
2607  case BuiltinType::Double:
2608    Out << 'd';
2609    break;
2610  case BuiltinType::LongDouble: {
2611    const TargetInfo *TI = getASTContext().getLangOpts().OpenMP &&
2612                                   getASTContext().getLangOpts().OpenMPIsDevice
2613                               ? getASTContext().getAuxTargetInfo()
2614                               : &getASTContext().getTargetInfo();
2615    Out << TI->getLongDoubleMangling();
2616    break;
2617  }
2618  case BuiltinType::Float128: {
2619    const TargetInfo *TI = getASTContext().getLangOpts().OpenMP &&
2620                                   getASTContext().getLangOpts().OpenMPIsDevice
2621                               ? getASTContext().getAuxTargetInfo()
2622                               : &getASTContext().getTargetInfo();
2623    Out << TI->getFloat128Mangling();
2624    break;
2625  }
2626  case BuiltinType::NullPtr:
2627    Out << "Dn";
2628    break;
2629
2630#define BUILTIN_TYPE(Id, SingletonId)
2631#define PLACEHOLDER_TYPE(Id, SingletonId) \
2632  case BuiltinType::Id:
2633#include "clang/AST/BuiltinTypes.def"
2634  case BuiltinType::Dependent:
2635    if (!NullOut)
2636      llvm_unreachable("mangling a placeholder type");
2637    break;
2638  case BuiltinType::ObjCId:
2639    Out << "11objc_object";
2640    break;
2641  case BuiltinType::ObjCClass:
2642    Out << "10objc_class";
2643    break;
2644  case BuiltinType::ObjCSel:
2645    Out << "13objc_selector";
2646    break;
2647#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
2648  case BuiltinType::Id: \
2649    type_name = "ocl_" #ImgType "_" #Suffix; \
2650    Out << type_name.size() << type_name; \
2651    break;
2652#include "clang/Basic/OpenCLImageTypes.def"
2653  case BuiltinType::OCLSampler:
2654    Out << "11ocl_sampler";
2655    break;
2656  case BuiltinType::OCLEvent:
2657    Out << "9ocl_event";
2658    break;
2659  case BuiltinType::OCLClkEvent:
2660    Out << "12ocl_clkevent";
2661    break;
2662  case BuiltinType::OCLQueue:
2663    Out << "9ocl_queue";
2664    break;
2665  case BuiltinType::OCLReserveID:
2666    Out << "13ocl_reserveid";
2667    break;
2668#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
2669  case BuiltinType::Id: \
2670    type_name = "ocl_" #ExtType; \
2671    Out << type_name.size() << type_name; \
2672    break;
2673#include "clang/Basic/OpenCLExtensionTypes.def"
2674  }
2675}
2676
2677StringRef CXXNameMangler::getCallingConvQualifierName(CallingConv CC) {
2678  switch (CC) {
2679  case CC_C:
2680    return "";
2681
2682  case CC_X86VectorCall:
2683  case CC_X86Pascal:
2684  case CC_X86RegCall:
2685  case CC_AAPCS:
2686  case CC_AAPCS_VFP:
2687  case CC_AArch64VectorCall:
2688  case CC_IntelOclBicc:
2689  case CC_SpirFunction:
2690  case CC_OpenCLKernel:
2691  case CC_PreserveMost:
2692  case CC_PreserveAll:
2693    // FIXME: we should be mangling all of the above.
2694    return "";
2695
2696  case CC_X86ThisCall:
2697    // FIXME: To match mingw GCC, thiscall should only be mangled in when it is
2698    // used explicitly. At this point, we don't have that much information in
2699    // the AST, since clang tends to bake the convention into the canonical
2700    // function type. thiscall only rarely used explicitly, so don't mangle it
2701    // for now.
2702    return "";
2703
2704  case CC_X86StdCall:
2705    return "stdcall";
2706  case CC_X86FastCall:
2707    return "fastcall";
2708  case CC_X86_64SysV:
2709    return "sysv_abi";
2710  case CC_Win64:
2711    return "ms_abi";
2712  case CC_Swift:
2713    return "swiftcall";
2714  }
2715  llvm_unreachable("bad calling convention");
2716}
2717
2718void CXXNameMangler::mangleExtFunctionInfo(const FunctionType *T) {
2719  // Fast path.
2720  if (T->getExtInfo() == FunctionType::ExtInfo())
2721    return;
2722
2723  // Vendor-specific qualifiers are emitted in reverse alphabetical order.
2724  // This will get more complicated in the future if we mangle other
2725  // things here; but for now, since we mangle ns_returns_retained as
2726  // a qualifier on the result type, we can get away with this:
2727  StringRef CCQualifier = getCallingConvQualifierName(T->getExtInfo().getCC());
2728  if (!CCQualifier.empty())
2729    mangleVendorQualifier(CCQualifier);
2730
2731  // FIXME: regparm
2732  // FIXME: noreturn
2733}
2734
2735void
2736CXXNameMangler::mangleExtParameterInfo(FunctionProtoType::ExtParameterInfo PI) {
2737  // Vendor-specific qualifiers are emitted in reverse alphabetical order.
2738
2739  // Note that these are *not* substitution candidates.  Demanglers might
2740  // have trouble with this if the parameter type is fully substituted.
2741
2742  switch (PI.getABI()) {
2743  case ParameterABI::Ordinary:
2744    break;
2745
2746  // All of these start with "swift", so they come before "ns_consumed".
2747  case ParameterABI::SwiftContext:
2748  case ParameterABI::SwiftErrorResult:
2749  case ParameterABI::SwiftIndirectResult:
2750    mangleVendorQualifier(getParameterABISpelling(PI.getABI()));
2751    break;
2752  }
2753
2754  if (PI.isConsumed())
2755    mangleVendorQualifier("ns_consumed");
2756
2757  if (PI.isNoEscape())
2758    mangleVendorQualifier("noescape");
2759}
2760
2761// <type>          ::= <function-type>
2762// <function-type> ::= [<CV-qualifiers>] F [Y]
2763//                      <bare-function-type> [<ref-qualifier>] E
2764void CXXNameMangler::mangleType(const FunctionProtoType *T) {
2765  mangleExtFunctionInfo(T);
2766
2767  // Mangle CV-qualifiers, if present.  These are 'this' qualifiers,
2768  // e.g. "const" in "int (A::*)() const".
2769  mangleQualifiers(T->getMethodQuals());
2770
2771  // Mangle instantiation-dependent exception-specification, if present,
2772  // per cxx-abi-dev proposal on 2016-10-11.
2773  if (T->hasInstantiationDependentExceptionSpec()) {
2774    if (isComputedNoexcept(T->getExceptionSpecType())) {
2775      Out << "DO";
2776      mangleExpression(T->getNoexceptExpr());
2777      Out << "E";
2778    } else {
2779      assert(T->getExceptionSpecType() == EST_Dynamic);
2780      Out << "Dw";
2781      for (auto ExceptTy : T->exceptions())
2782        mangleType(ExceptTy);
2783      Out << "E";
2784    }
2785  } else if (T->isNothrow()) {
2786    Out << "Do";
2787  }
2788
2789  Out << 'F';
2790
2791  // FIXME: We don't have enough information in the AST to produce the 'Y'
2792  // encoding for extern "C" function types.
2793  mangleBareFunctionType(T, /*MangleReturnType=*/true);
2794
2795  // Mangle the ref-qualifier, if present.
2796  mangleRefQualifier(T->getRefQualifier());
2797
2798  Out << 'E';
2799}
2800
2801void CXXNameMangler::mangleType(const FunctionNoProtoType *T) {
2802  // Function types without prototypes can arise when mangling a function type
2803  // within an overloadable function in C. We mangle these as the absence of any
2804  // parameter types (not even an empty parameter list).
2805  Out << 'F';
2806
2807  FunctionTypeDepthState saved = FunctionTypeDepth.push();
2808
2809  FunctionTypeDepth.enterResultType();
2810  mangleType(T->getReturnType());
2811  FunctionTypeDepth.leaveResultType();
2812
2813  FunctionTypeDepth.pop(saved);
2814  Out << 'E';
2815}
2816
2817void CXXNameMangler::mangleBareFunctionType(const FunctionProtoType *Proto,
2818                                            bool MangleReturnType,
2819                                            const FunctionDecl *FD) {
2820  // Record that we're in a function type.  See mangleFunctionParam
2821  // for details on what we're trying to achieve here.
2822  FunctionTypeDepthState saved = FunctionTypeDepth.push();
2823
2824  // <bare-function-type> ::= <signature type>+
2825  if (MangleReturnType) {
2826    FunctionTypeDepth.enterResultType();
2827
2828    // Mangle ns_returns_retained as an order-sensitive qualifier here.
2829    if (Proto->getExtInfo().getProducesResult() && FD == nullptr)
2830      mangleVendorQualifier("ns_returns_retained");
2831
2832    // Mangle the return type without any direct ARC ownership qualifiers.
2833    QualType ReturnTy = Proto->getReturnType();
2834    if (ReturnTy.getObjCLifetime()) {
2835      auto SplitReturnTy = ReturnTy.split();
2836      SplitReturnTy.Quals.removeObjCLifetime();
2837      ReturnTy = getASTContext().getQualifiedType(SplitReturnTy);
2838    }
2839    mangleType(ReturnTy);
2840
2841    FunctionTypeDepth.leaveResultType();
2842  }
2843
2844  if (Proto->getNumParams() == 0 && !Proto->isVariadic()) {
2845    //   <builtin-type> ::= v   # void
2846    Out << 'v';
2847
2848    FunctionTypeDepth.pop(saved);
2849    return;
2850  }
2851
2852  assert(!FD || FD->getNumParams() == Proto->getNumParams());
2853  for (unsigned I = 0, E = Proto->getNumParams(); I != E; ++I) {
2854    // Mangle extended parameter info as order-sensitive qualifiers here.
2855    if (Proto->hasExtParameterInfos() && FD == nullptr) {
2856      mangleExtParameterInfo(Proto->getExtParameterInfo(I));
2857    }
2858
2859    // Mangle the type.
2860    QualType ParamTy = Proto->getParamType(I);
2861    mangleType(Context.getASTContext().getSignatureParameterType(ParamTy));
2862
2863    if (FD) {
2864      if (auto *Attr = FD->getParamDecl(I)->getAttr<PassObjectSizeAttr>()) {
2865        // Attr can only take 1 character, so we can hardcode the length below.
2866        assert(Attr->getType() <= 9 && Attr->getType() >= 0);
2867        if (Attr->isDynamic())
2868          Out << "U25pass_dynamic_object_size" << Attr->getType();
2869        else
2870          Out << "U17pass_object_size" << Attr->getType();
2871      }
2872    }
2873  }
2874
2875  FunctionTypeDepth.pop(saved);
2876
2877  // <builtin-type>      ::= z  # ellipsis
2878  if (Proto->isVariadic())
2879    Out << 'z';
2880}
2881
2882// <type>            ::= <class-enum-type>
2883// <class-enum-type> ::= <name>
2884void CXXNameMangler::mangleType(const UnresolvedUsingType *T) {
2885  mangleName(T->getDecl());
2886}
2887
2888// <type>            ::= <class-enum-type>
2889// <class-enum-type> ::= <name>
2890void CXXNameMangler::mangleType(const EnumType *T) {
2891  mangleType(static_cast<const TagType*>(T));
2892}
2893void CXXNameMangler::mangleType(const RecordType *T) {
2894  mangleType(static_cast<const TagType*>(T));
2895}
2896void CXXNameMangler::mangleType(const TagType *T) {
2897  mangleName(T->getDecl());
2898}
2899
2900// <type>       ::= <array-type>
2901// <array-type> ::= A <positive dimension number> _ <element type>
2902//              ::= A [<dimension expression>] _ <element type>
2903void CXXNameMangler::mangleType(const ConstantArrayType *T) {
2904  Out << 'A' << T->getSize() << '_';
2905  mangleType(T->getElementType());
2906}
2907void CXXNameMangler::mangleType(const VariableArrayType *T) {
2908  Out << 'A';
2909  // decayed vla types (size 0) will just be skipped.
2910  if (T->getSizeExpr())
2911    mangleExpression(T->getSizeExpr());
2912  Out << '_';
2913  mangleType(T->getElementType());
2914}
2915void CXXNameMangler::mangleType(const DependentSizedArrayType *T) {
2916  Out << 'A';
2917  mangleExpression(T->getSizeExpr());
2918  Out << '_';
2919  mangleType(T->getElementType());
2920}
2921void CXXNameMangler::mangleType(const IncompleteArrayType *T) {
2922  Out << "A_";
2923  mangleType(T->getElementType());
2924}
2925
2926// <type>                   ::= <pointer-to-member-type>
2927// <pointer-to-member-type> ::= M <class type> <member type>
2928void CXXNameMangler::mangleType(const MemberPointerType *T) {
2929  Out << 'M';
2930  mangleType(QualType(T->getClass(), 0));
2931  QualType PointeeType = T->getPointeeType();
2932  if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(PointeeType)) {
2933    mangleType(FPT);
2934
2935    // Itanium C++ ABI 5.1.8:
2936    //
2937    //   The type of a non-static member function is considered to be different,
2938    //   for the purposes of substitution, from the type of a namespace-scope or
2939    //   static member function whose type appears similar. The types of two
2940    //   non-static member functions are considered to be different, for the
2941    //   purposes of substitution, if the functions are members of different
2942    //   classes. In other words, for the purposes of substitution, the class of
2943    //   which the function is a member is considered part of the type of
2944    //   function.
2945
2946    // Given that we already substitute member function pointers as a
2947    // whole, the net effect of this rule is just to unconditionally
2948    // suppress substitution on the function type in a member pointer.
2949    // We increment the SeqID here to emulate adding an entry to the
2950    // substitution table.
2951    ++SeqID;
2952  } else
2953    mangleType(PointeeType);
2954}
2955
2956// <type>           ::= <template-param>
2957void CXXNameMangler::mangleType(const TemplateTypeParmType *T) {
2958  mangleTemplateParameter(T->getIndex());
2959}
2960
2961// <type>           ::= <template-param>
2962void CXXNameMangler::mangleType(const SubstTemplateTypeParmPackType *T) {
2963  // FIXME: not clear how to mangle this!
2964  // template <class T...> class A {
2965  //   template <class U...> void foo(T(*)(U) x...);
2966  // };
2967  Out << "_SUBSTPACK_";
2968}
2969
2970// <type> ::= P <type>   # pointer-to
2971void CXXNameMangler::mangleType(const PointerType *T) {
2972  Out << 'P';
2973  mangleType(T->getPointeeType());
2974}
2975void CXXNameMangler::mangleType(const ObjCObjectPointerType *T) {
2976  Out << 'P';
2977  mangleType(T->getPointeeType());
2978}
2979
2980// <type> ::= R <type>   # reference-to
2981void CXXNameMangler::mangleType(const LValueReferenceType *T) {
2982  Out << 'R';
2983  mangleType(T->getPointeeType());
2984}
2985
2986// <type> ::= O <type>   # rvalue reference-to (C++0x)
2987void CXXNameMangler::mangleType(const RValueReferenceType *T) {
2988  Out << 'O';
2989  mangleType(T->getPointeeType());
2990}
2991
2992// <type> ::= C <type>   # complex pair (C 2000)
2993void CXXNameMangler::mangleType(const ComplexType *T) {
2994  Out << 'C';
2995  mangleType(T->getElementType());
2996}
2997
2998// ARM's ABI for Neon vector types specifies that they should be mangled as
2999// if they are structs (to match ARM's initial implementation).  The
3000// vector type must be one of the special types predefined by ARM.
3001void CXXNameMangler::mangleNeonVectorType(const VectorType *T) {
3002  QualType EltType = T->getElementType();
3003  assert(EltType->isBuiltinType() && "Neon vector element not a BuiltinType");
3004  const char *EltName = nullptr;
3005  if (T->getVectorKind() == VectorType::NeonPolyVector) {
3006    switch (cast<BuiltinType>(EltType)->getKind()) {
3007    case BuiltinType::SChar:
3008    case BuiltinType::UChar:
3009      EltName = "poly8_t";
3010      break;
3011    case BuiltinType::Short:
3012    case BuiltinType::UShort:
3013      EltName = "poly16_t";
3014      break;
3015    case BuiltinType::ULongLong:
3016      EltName = "poly64_t";
3017      break;
3018    default: llvm_unreachable("unexpected Neon polynomial vector element type");
3019    }
3020  } else {
3021    switch (cast<BuiltinType>(EltType)->getKind()) {
3022    case BuiltinType::SChar:     EltName = "int8_t"; break;
3023    case BuiltinType::UChar:     EltName = "uint8_t"; break;
3024    case BuiltinType::Short:     EltName = "int16_t"; break;
3025    case BuiltinType::UShort:    EltName = "uint16_t"; break;
3026    case BuiltinType::Int:       EltName = "int32_t"; break;
3027    case BuiltinType::UInt:      EltName = "uint32_t"; break;
3028    case BuiltinType::LongLong:  EltName = "int64_t"; break;
3029    case BuiltinType::ULongLong: EltName = "uint64_t"; break;
3030    case BuiltinType::Double:    EltName = "float64_t"; break;
3031    case BuiltinType::Float:     EltName = "float32_t"; break;
3032    case BuiltinType::Half:      EltName = "float16_t";break;
3033    default:
3034      llvm_unreachable("unexpected Neon vector element type");
3035    }
3036  }
3037  const char *BaseName = nullptr;
3038  unsigned BitSize = (T->getNumElements() *
3039                      getASTContext().getTypeSize(EltType));
3040  if (BitSize == 64)
3041    BaseName = "__simd64_";
3042  else {
3043    assert(BitSize == 128 && "Neon vector type not 64 or 128 bits");
3044    BaseName = "__simd128_";
3045  }
3046  Out << strlen(BaseName) + strlen(EltName);
3047  Out << BaseName << EltName;
3048}
3049
3050void CXXNameMangler::mangleNeonVectorType(const DependentVectorType *T) {
3051  DiagnosticsEngine &Diags = Context.getDiags();
3052  unsigned DiagID = Diags.getCustomDiagID(
3053      DiagnosticsEngine::Error,
3054      "cannot mangle this dependent neon vector type yet");
3055  Diags.Report(T->getAttributeLoc(), DiagID);
3056}
3057
3058static StringRef mangleAArch64VectorBase(const BuiltinType *EltType) {
3059  switch (EltType->getKind()) {
3060  case BuiltinType::SChar:
3061    return "Int8";
3062  case BuiltinType::Short:
3063    return "Int16";
3064  case BuiltinType::Int:
3065    return "Int32";
3066  case BuiltinType::Long:
3067  case BuiltinType::LongLong:
3068    return "Int64";
3069  case BuiltinType::UChar:
3070    return "Uint8";
3071  case BuiltinType::UShort:
3072    return "Uint16";
3073  case BuiltinType::UInt:
3074    return "Uint32";
3075  case BuiltinType::ULong:
3076  case BuiltinType::ULongLong:
3077    return "Uint64";
3078  case BuiltinType::Half:
3079    return "Float16";
3080  case BuiltinType::Float:
3081    return "Float32";
3082  case BuiltinType::Double:
3083    return "Float64";
3084  default:
3085    llvm_unreachable("Unexpected vector element base type");
3086  }
3087}
3088
3089// AArch64's ABI for Neon vector types specifies that they should be mangled as
3090// the equivalent internal name. The vector type must be one of the special
3091// types predefined by ARM.
3092void CXXNameMangler::mangleAArch64NeonVectorType(const VectorType *T) {
3093  QualType EltType = T->getElementType();
3094  assert(EltType->isBuiltinType() && "Neon vector element not a BuiltinType");
3095  unsigned BitSize =
3096      (T->getNumElements() * getASTContext().getTypeSize(EltType));
3097  (void)BitSize; // Silence warning.
3098
3099  assert((BitSize == 64 || BitSize == 128) &&
3100         "Neon vector type not 64 or 128 bits");
3101
3102  StringRef EltName;
3103  if (T->getVectorKind() == VectorType::NeonPolyVector) {
3104    switch (cast<BuiltinType>(EltType)->getKind()) {
3105    case BuiltinType::UChar:
3106      EltName = "Poly8";
3107      break;
3108    case BuiltinType::UShort:
3109      EltName = "Poly16";
3110      break;
3111    case BuiltinType::ULong:
3112    case BuiltinType::ULongLong:
3113      EltName = "Poly64";
3114      break;
3115    default:
3116      llvm_unreachable("unexpected Neon polynomial vector element type");
3117    }
3118  } else
3119    EltName = mangleAArch64VectorBase(cast<BuiltinType>(EltType));
3120
3121  std::string TypeName =
3122      ("__" + EltName + "x" + Twine(T->getNumElements()) + "_t").str();
3123  Out << TypeName.length() << TypeName;
3124}
3125void CXXNameMangler::mangleAArch64NeonVectorType(const DependentVectorType *T) {
3126  DiagnosticsEngine &Diags = Context.getDiags();
3127  unsigned DiagID = Diags.getCustomDiagID(
3128      DiagnosticsEngine::Error,
3129      "cannot mangle this dependent neon vector type yet");
3130  Diags.Report(T->getAttributeLoc(), DiagID);
3131}
3132
3133// GNU extension: vector types
3134// <type>                  ::= <vector-type>
3135// <vector-type>           ::= Dv <positive dimension number> _
3136//                                    <extended element type>
3137//                         ::= Dv [<dimension expression>] _ <element type>
3138// <extended element type> ::= <element type>
3139//                         ::= p # AltiVec vector pixel
3140//                         ::= b # Altivec vector bool
3141void CXXNameMangler::mangleType(const VectorType *T) {
3142  if ((T->getVectorKind() == VectorType::NeonVector ||
3143       T->getVectorKind() == VectorType::NeonPolyVector)) {
3144    llvm::Triple Target = getASTContext().getTargetInfo().getTriple();
3145    llvm::Triple::ArchType Arch =
3146        getASTContext().getTargetInfo().getTriple().getArch();
3147    if ((Arch == llvm::Triple::aarch64 ||
3148         Arch == llvm::Triple::aarch64_be) && !Target.isOSDarwin())
3149      mangleAArch64NeonVectorType(T);
3150    else
3151      mangleNeonVectorType(T);
3152    return;
3153  }
3154  Out << "Dv" << T->getNumElements() << '_';
3155  if (T->getVectorKind() == VectorType::AltiVecPixel)
3156    Out << 'p';
3157  else if (T->getVectorKind() == VectorType::AltiVecBool)
3158    Out << 'b';
3159  else
3160    mangleType(T->getElementType());
3161}
3162
3163void CXXNameMangler::mangleType(const DependentVectorType *T) {
3164  if ((T->getVectorKind() == VectorType::NeonVector ||
3165       T->getVectorKind() == VectorType::NeonPolyVector)) {
3166    llvm::Triple Target = getASTContext().getTargetInfo().getTriple();
3167    llvm::Triple::ArchType Arch =
3168        getASTContext().getTargetInfo().getTriple().getArch();
3169    if ((Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_be) &&
3170        !Target.isOSDarwin())
3171      mangleAArch64NeonVectorType(T);
3172    else
3173      mangleNeonVectorType(T);
3174    return;
3175  }
3176
3177  Out << "Dv";
3178  mangleExpression(T->getSizeExpr());
3179  Out << '_';
3180  if (T->getVectorKind() == VectorType::AltiVecPixel)
3181    Out << 'p';
3182  else if (T->getVectorKind() == VectorType::AltiVecBool)
3183    Out << 'b';
3184  else
3185    mangleType(T->getElementType());
3186}
3187
3188void CXXNameMangler::mangleType(const ExtVectorType *T) {
3189  mangleType(static_cast<const VectorType*>(T));
3190}
3191void CXXNameMangler::mangleType(const DependentSizedExtVectorType *T) {
3192  Out << "Dv";
3193  mangleExpression(T->getSizeExpr());
3194  Out << '_';
3195  mangleType(T->getElementType());
3196}
3197
3198void CXXNameMangler::mangleType(const DependentAddressSpaceType *T) {
3199  SplitQualType split = T->getPointeeType().split();
3200  mangleQualifiers(split.Quals, T);
3201  mangleType(QualType(split.Ty, 0));
3202}
3203
3204void CXXNameMangler::mangleType(const PackExpansionType *T) {
3205  // <type>  ::= Dp <type>          # pack expansion (C++0x)
3206  Out << "Dp";
3207  mangleType(T->getPattern());
3208}
3209
3210void CXXNameMangler::mangleType(const ObjCInterfaceType *T) {
3211  mangleSourceName(T->getDecl()->getIdentifier());
3212}
3213
3214void CXXNameMangler::mangleType(const ObjCObjectType *T) {
3215  // Treat __kindof as a vendor extended type qualifier.
3216  if (T->isKindOfType())
3217    Out << "U8__kindof";
3218
3219  if (!T->qual_empty()) {
3220    // Mangle protocol qualifiers.
3221    SmallString<64> QualStr;
3222    llvm::raw_svector_ostream QualOS(QualStr);
3223    QualOS << "objcproto";
3224    for (const auto *I : T->quals()) {
3225      StringRef name = I->getName();
3226      QualOS << name.size() << name;
3227    }
3228    Out << 'U' << QualStr.size() << QualStr;
3229  }
3230
3231  mangleType(T->getBaseType());
3232
3233  if (T->isSpecialized()) {
3234    // Mangle type arguments as I <type>+ E
3235    Out << 'I';
3236    for (auto typeArg : T->getTypeArgs())
3237      mangleType(typeArg);
3238    Out << 'E';
3239  }
3240}
3241
3242void CXXNameMangler::mangleType(const BlockPointerType *T) {
3243  Out << "U13block_pointer";
3244  mangleType(T->getPointeeType());
3245}
3246
3247void CXXNameMangler::mangleType(const InjectedClassNameType *T) {
3248  // Mangle injected class name types as if the user had written the
3249  // specialization out fully.  It may not actually be possible to see
3250  // this mangling, though.
3251  mangleType(T->getInjectedSpecializationType());
3252}
3253
3254void CXXNameMangler::mangleType(const TemplateSpecializationType *T) {
3255  if (TemplateDecl *TD = T->getTemplateName().getAsTemplateDecl()) {
3256    mangleTemplateName(TD, T->getArgs(), T->getNumArgs());
3257  } else {
3258    if (mangleSubstitution(QualType(T, 0)))
3259      return;
3260
3261    mangleTemplatePrefix(T->getTemplateName());
3262
3263    // FIXME: GCC does not appear to mangle the template arguments when
3264    // the template in question is a dependent template name. Should we
3265    // emulate that badness?
3266    mangleTemplateArgs(T->getArgs(), T->getNumArgs());
3267    addSubstitution(QualType(T, 0));
3268  }
3269}
3270
3271void CXXNameMangler::mangleType(const DependentNameType *T) {
3272  // Proposal by cxx-abi-dev, 2014-03-26
3273  // <class-enum-type> ::= <name>    # non-dependent or dependent type name or
3274  //                                 # dependent elaborated type specifier using
3275  //                                 # 'typename'
3276  //                   ::= Ts <name> # dependent elaborated type specifier using
3277  //                                 # 'struct' or 'class'
3278  //                   ::= Tu <name> # dependent elaborated type specifier using
3279  //                                 # 'union'
3280  //                   ::= Te <name> # dependent elaborated type specifier using
3281  //                                 # 'enum'
3282  switch (T->getKeyword()) {
3283    case ETK_None:
3284    case ETK_Typename:
3285      break;
3286    case ETK_Struct:
3287    case ETK_Class:
3288    case ETK_Interface:
3289      Out << "Ts";
3290      break;
3291    case ETK_Union:
3292      Out << "Tu";
3293      break;
3294    case ETK_Enum:
3295      Out << "Te";
3296      break;
3297  }
3298  // Typename types are always nested
3299  Out << 'N';
3300  manglePrefix(T->getQualifier());
3301  mangleSourceName(T->getIdentifier());
3302  Out << 'E';
3303}
3304
3305void CXXNameMangler::mangleType(const DependentTemplateSpecializationType *T) {
3306  // Dependently-scoped template types are nested if they have a prefix.
3307  Out << 'N';
3308
3309  // TODO: avoid making this TemplateName.
3310  TemplateName Prefix =
3311    getASTContext().getDependentTemplateName(T->getQualifier(),
3312                                             T->getIdentifier());
3313  mangleTemplatePrefix(Prefix);
3314
3315  // FIXME: GCC does not appear to mangle the template arguments when
3316  // the template in question is a dependent template name. Should we
3317  // emulate that badness?
3318  mangleTemplateArgs(T->getArgs(), T->getNumArgs());
3319  Out << 'E';
3320}
3321
3322void CXXNameMangler::mangleType(const TypeOfType *T) {
3323  // FIXME: this is pretty unsatisfactory, but there isn't an obvious
3324  // "extension with parameters" mangling.
3325  Out << "u6typeof";
3326}
3327
3328void CXXNameMangler::mangleType(const TypeOfExprType *T) {
3329  // FIXME: this is pretty unsatisfactory, but there isn't an obvious
3330  // "extension with parameters" mangling.
3331  Out << "u6typeof";
3332}
3333
3334void CXXNameMangler::mangleType(const DecltypeType *T) {
3335  Expr *E = T->getUnderlyingExpr();
3336
3337  // type ::= Dt <expression> E  # decltype of an id-expression
3338  //                             #   or class member access
3339  //      ::= DT <expression> E  # decltype of an expression
3340
3341  // This purports to be an exhaustive list of id-expressions and
3342  // class member accesses.  Note that we do not ignore parentheses;
3343  // parentheses change the semantics of decltype for these
3344  // expressions (and cause the mangler to use the other form).
3345  if (isa<DeclRefExpr>(E) ||
3346      isa<MemberExpr>(E) ||
3347      isa<UnresolvedLookupExpr>(E) ||
3348      isa<DependentScopeDeclRefExpr>(E) ||
3349      isa<CXXDependentScopeMemberExpr>(E) ||
3350      isa<UnresolvedMemberExpr>(E))
3351    Out << "Dt";
3352  else
3353    Out << "DT";
3354  mangleExpression(E);
3355  Out << 'E';
3356}
3357
3358void CXXNameMangler::mangleType(const UnaryTransformType *T) {
3359  // If this is dependent, we need to record that. If not, we simply
3360  // mangle it as the underlying type since they are equivalent.
3361  if (T->isDependentType()) {
3362    Out << 'U';
3363
3364    switch (T->getUTTKind()) {
3365      case UnaryTransformType::EnumUnderlyingType:
3366        Out << "3eut";
3367        break;
3368    }
3369  }
3370
3371  mangleType(T->getBaseType());
3372}
3373
3374void CXXNameMangler::mangleType(const AutoType *T) {
3375  assert(T->getDeducedType().isNull() &&
3376         "Deduced AutoType shouldn't be handled here!");
3377  assert(T->getKeyword() != AutoTypeKeyword::GNUAutoType &&
3378         "shouldn't need to mangle __auto_type!");
3379  // <builtin-type> ::= Da # auto
3380  //                ::= Dc # decltype(auto)
3381  Out << (T->isDecltypeAuto() ? "Dc" : "Da");
3382}
3383
3384void CXXNameMangler::mangleType(const DeducedTemplateSpecializationType *T) {
3385  // FIXME: This is not the right mangling. We also need to include a scope
3386  // here in some cases.
3387  QualType D = T->getDeducedType();
3388  if (D.isNull())
3389    mangleUnscopedTemplateName(T->getTemplateName(), nullptr);
3390  else
3391    mangleType(D);
3392}
3393
3394void CXXNameMangler::mangleType(const AtomicType *T) {
3395  // <type> ::= U <source-name> <type>  # vendor extended type qualifier
3396  // (Until there's a standardized mangling...)
3397  Out << "U7_Atomic";
3398  mangleType(T->getValueType());
3399}
3400
3401void CXXNameMangler::mangleType(const PipeType *T) {
3402  // Pipe type mangling rules are described in SPIR 2.0 specification
3403  // A.1 Data types and A.3 Summary of changes
3404  // <type> ::= 8ocl_pipe
3405  Out << "8ocl_pipe";
3406}
3407
3408void CXXNameMangler::mangleIntegerLiteral(QualType T,
3409                                          const llvm::APSInt &Value) {
3410  //  <expr-primary> ::= L <type> <value number> E # integer literal
3411  Out << 'L';
3412
3413  mangleType(T);
3414  if (T->isBooleanType()) {
3415    // Boolean values are encoded as 0/1.
3416    Out << (Value.getBoolValue() ? '1' : '0');
3417  } else {
3418    mangleNumber(Value);
3419  }
3420  Out << 'E';
3421
3422}
3423
3424void CXXNameMangler::mangleMemberExprBase(const Expr *Base, bool IsArrow) {
3425  // Ignore member expressions involving anonymous unions.
3426  while (const auto *RT = Base->getType()->getAs<RecordType>()) {
3427    if (!RT->getDecl()->isAnonymousStructOrUnion())
3428      break;
3429    const auto *ME = dyn_cast<MemberExpr>(Base);
3430    if (!ME)
3431      break;
3432    Base = ME->getBase();
3433    IsArrow = ME->isArrow();
3434  }
3435
3436  if (Base->isImplicitCXXThis()) {
3437    // Note: GCC mangles member expressions to the implicit 'this' as
3438    // *this., whereas we represent them as this->. The Itanium C++ ABI
3439    // does not specify anything here, so we follow GCC.
3440    Out << "dtdefpT";
3441  } else {
3442    Out << (IsArrow ? "pt" : "dt");
3443    mangleExpression(Base);
3444  }
3445}
3446
3447/// Mangles a member expression.
3448void CXXNameMangler::mangleMemberExpr(const Expr *base,
3449                                      bool isArrow,
3450                                      NestedNameSpecifier *qualifier,
3451                                      NamedDecl *firstQualifierLookup,
3452                                      DeclarationName member,
3453                                      const TemplateArgumentLoc *TemplateArgs,
3454                                      unsigned NumTemplateArgs,
3455                                      unsigned arity) {
3456  // <expression> ::= dt <expression> <unresolved-name>
3457  //              ::= pt <expression> <unresolved-name>
3458  if (base)
3459    mangleMemberExprBase(base, isArrow);
3460  mangleUnresolvedName(qualifier, member, TemplateArgs, NumTemplateArgs, arity);
3461}
3462
3463/// Look at the callee of the given call expression and determine if
3464/// it's a parenthesized id-expression which would have triggered ADL
3465/// otherwise.
3466static bool isParenthesizedADLCallee(const CallExpr *call) {
3467  const Expr *callee = call->getCallee();
3468  const Expr *fn = callee->IgnoreParens();
3469
3470  // Must be parenthesized.  IgnoreParens() skips __extension__ nodes,
3471  // too, but for those to appear in the callee, it would have to be
3472  // parenthesized.
3473  if (callee == fn) return false;
3474
3475  // Must be an unresolved lookup.
3476  const UnresolvedLookupExpr *lookup = dyn_cast<UnresolvedLookupExpr>(fn);
3477  if (!lookup) return false;
3478
3479  assert(!lookup->requiresADL());
3480
3481  // Must be an unqualified lookup.
3482  if (lookup->getQualifier()) return false;
3483
3484  // Must not have found a class member.  Note that if one is a class
3485  // member, they're all class members.
3486  if (lookup->getNumDecls() > 0 &&
3487      (*lookup->decls_begin())->isCXXClassMember())
3488    return false;
3489
3490  // Otherwise, ADL would have been triggered.
3491  return true;
3492}
3493
3494void CXXNameMangler::mangleCastExpression(const Expr *E, StringRef CastEncoding) {
3495  const ExplicitCastExpr *ECE = cast<ExplicitCastExpr>(E);
3496  Out << CastEncoding;
3497  mangleType(ECE->getType());
3498  mangleExpression(ECE->getSubExpr());
3499}
3500
3501void CXXNameMangler::mangleInitListElements(const InitListExpr *InitList) {
3502  if (auto *Syntactic = InitList->getSyntacticForm())
3503    InitList = Syntactic;
3504  for (unsigned i = 0, e = InitList->getNumInits(); i != e; ++i)
3505    mangleExpression(InitList->getInit(i));
3506}
3507
3508void CXXNameMangler::mangleDeclRefExpr(const NamedDecl *D) {
3509  switch (D->getKind()) {
3510  default:
3511    //  <expr-primary> ::= L <mangled-name> E # external name
3512    Out << 'L';
3513    mangle(D);
3514    Out << 'E';
3515    break;
3516
3517  case Decl::ParmVar:
3518    mangleFunctionParam(cast<ParmVarDecl>(D));
3519    break;
3520
3521  case Decl::EnumConstant: {
3522    const EnumConstantDecl *ED = cast<EnumConstantDecl>(D);
3523    mangleIntegerLiteral(ED->getType(), ED->getInitVal());
3524    break;
3525  }
3526
3527  case Decl::NonTypeTemplateParm:
3528    const NonTypeTemplateParmDecl *PD = cast<NonTypeTemplateParmDecl>(D);
3529    mangleTemplateParameter(PD->getIndex());
3530    break;
3531  }
3532}
3533
3534void CXXNameMangler::mangleExpression(const Expr *E, unsigned Arity) {
3535  // <expression> ::= <unary operator-name> <expression>
3536  //              ::= <binary operator-name> <expression> <expression>
3537  //              ::= <trinary operator-name> <expression> <expression> <expression>
3538  //              ::= cv <type> expression           # conversion with one argument
3539  //              ::= cv <type> _ <expression>* E # conversion with a different number of arguments
3540  //              ::= dc <type> <expression>         # dynamic_cast<type> (expression)
3541  //              ::= sc <type> <expression>         # static_cast<type> (expression)
3542  //              ::= cc <type> <expression>         # const_cast<type> (expression)
3543  //              ::= rc <type> <expression>         # reinterpret_cast<type> (expression)
3544  //              ::= st <type>                      # sizeof (a type)
3545  //              ::= at <type>                      # alignof (a type)
3546  //              ::= <template-param>
3547  //              ::= <function-param>
3548  //              ::= sr <type> <unqualified-name>                   # dependent name
3549  //              ::= sr <type> <unqualified-name> <template-args>   # dependent template-id
3550  //              ::= ds <expression> <expression>                   # expr.*expr
3551  //              ::= sZ <template-param>                            # size of a parameter pack
3552  //              ::= sZ <function-param>    # size of a function parameter pack
3553  //              ::= <expr-primary>
3554  // <expr-primary> ::= L <type> <value number> E    # integer literal
3555  //                ::= L <type <value float> E      # floating literal
3556  //                ::= L <mangled-name> E           # external name
3557  //                ::= fpT                          # 'this' expression
3558  QualType ImplicitlyConvertedToType;
3559
3560recurse:
3561  switch (E->getStmtClass()) {
3562  case Expr::NoStmtClass:
3563#define ABSTRACT_STMT(Type)
3564#define EXPR(Type, Base)
3565#define STMT(Type, Base) \
3566  case Expr::Type##Class:
3567#include "clang/AST/StmtNodes.inc"
3568    // fallthrough
3569
3570  // These all can only appear in local or variable-initialization
3571  // contexts and so should never appear in a mangling.
3572  case Expr::AddrLabelExprClass:
3573  case Expr::DesignatedInitUpdateExprClass:
3574  case Expr::ImplicitValueInitExprClass:
3575  case Expr::ArrayInitLoopExprClass:
3576  case Expr::ArrayInitIndexExprClass:
3577  case Expr::NoInitExprClass:
3578  case Expr::ParenListExprClass:
3579  case Expr::LambdaExprClass:
3580  case Expr::MSPropertyRefExprClass:
3581  case Expr::MSPropertySubscriptExprClass:
3582  case Expr::TypoExprClass:  // This should no longer exist in the AST by now.
3583  case Expr::OMPArraySectionExprClass:
3584  case Expr::CXXInheritedCtorInitExprClass:
3585    llvm_unreachable("unexpected statement kind");
3586
3587  case Expr::ConstantExprClass:
3588    E = cast<ConstantExpr>(E)->getSubExpr();
3589    goto recurse;
3590
3591  // FIXME: invent manglings for all these.
3592  case Expr::BlockExprClass:
3593  case Expr::ChooseExprClass:
3594  case Expr::CompoundLiteralExprClass:
3595  case Expr::ExtVectorElementExprClass:
3596  case Expr::GenericSelectionExprClass:
3597  case Expr::ObjCEncodeExprClass:
3598  case Expr::ObjCIsaExprClass:
3599  case Expr::ObjCIvarRefExprClass:
3600  case Expr::ObjCMessageExprClass:
3601  case Expr::ObjCPropertyRefExprClass:
3602  case Expr::ObjCProtocolExprClass:
3603  case Expr::ObjCSelectorExprClass:
3604  case Expr::ObjCStringLiteralClass:
3605  case Expr::ObjCBoxedExprClass:
3606  case Expr::ObjCArrayLiteralClass:
3607  case Expr::ObjCDictionaryLiteralClass:
3608  case Expr::ObjCSubscriptRefExprClass:
3609  case Expr::ObjCIndirectCopyRestoreExprClass:
3610  case Expr::ObjCAvailabilityCheckExprClass:
3611  case Expr::OffsetOfExprClass:
3612  case Expr::PredefinedExprClass:
3613  case Expr::ShuffleVectorExprClass:
3614  case Expr::ConvertVectorExprClass:
3615  case Expr::StmtExprClass:
3616  case Expr::TypeTraitExprClass:
3617  case Expr::ArrayTypeTraitExprClass:
3618  case Expr::ExpressionTraitExprClass:
3619  case Expr::VAArgExprClass:
3620  case Expr::CUDAKernelCallExprClass:
3621  case Expr::AsTypeExprClass:
3622  case Expr::PseudoObjectExprClass:
3623  case Expr::AtomicExprClass:
3624  case Expr::SourceLocExprClass:
3625  case Expr::FixedPointLiteralClass:
3626  case Expr::BuiltinBitCastExprClass:
3627  {
3628    if (!NullOut) {
3629      // As bad as this diagnostic is, it's better than crashing.
3630      DiagnosticsEngine &Diags = Context.getDiags();
3631      unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3632                                       "cannot yet mangle expression type %0");
3633      Diags.Report(E->getExprLoc(), DiagID)
3634        << E->getStmtClassName() << E->getSourceRange();
3635    }
3636    break;
3637  }
3638
3639  case Expr::CXXUuidofExprClass: {
3640    const CXXUuidofExpr *UE = cast<CXXUuidofExpr>(E);
3641    if (UE->isTypeOperand()) {
3642      QualType UuidT = UE->getTypeOperand(Context.getASTContext());
3643      Out << "u8__uuidoft";
3644      mangleType(UuidT);
3645    } else {
3646      Expr *UuidExp = UE->getExprOperand();
3647      Out << "u8__uuidofz";
3648      mangleExpression(UuidExp, Arity);
3649    }
3650    break;
3651  }
3652
3653  // Even gcc-4.5 doesn't mangle this.
3654  case Expr::BinaryConditionalOperatorClass: {
3655    DiagnosticsEngine &Diags = Context.getDiags();
3656    unsigned DiagID =
3657      Diags.getCustomDiagID(DiagnosticsEngine::Error,
3658                "?: operator with omitted middle operand cannot be mangled");
3659    Diags.Report(E->getExprLoc(), DiagID)
3660      << E->getStmtClassName() << E->getSourceRange();
3661    break;
3662  }
3663
3664  // These are used for internal purposes and cannot be meaningfully mangled.
3665  case Expr::OpaqueValueExprClass:
3666    llvm_unreachable("cannot mangle opaque value; mangling wrong thing?");
3667
3668  case Expr::InitListExprClass: {
3669    Out << "il";
3670    mangleInitListElements(cast<InitListExpr>(E));
3671    Out << "E";
3672    break;
3673  }
3674
3675  case Expr::DesignatedInitExprClass: {
3676    auto *DIE = cast<DesignatedInitExpr>(E);
3677    for (const auto &Designator : DIE->designators()) {
3678      if (Designator.isFieldDesignator()) {
3679        Out << "di";
3680        mangleSourceName(Designator.getFieldName());
3681      } else if (Designator.isArrayDesignator()) {
3682        Out << "dx";
3683        mangleExpression(DIE->getArrayIndex(Designator));
3684      } else {
3685        assert(Designator.isArrayRangeDesignator() &&
3686               "unknown designator kind");
3687        Out << "dX";
3688        mangleExpression(DIE->getArrayRangeStart(Designator));
3689        mangleExpression(DIE->getArrayRangeEnd(Designator));
3690      }
3691    }
3692    mangleExpression(DIE->getInit());
3693    break;
3694  }
3695
3696  case Expr::CXXDefaultArgExprClass:
3697    mangleExpression(cast<CXXDefaultArgExpr>(E)->getExpr(), Arity);
3698    break;
3699
3700  case Expr::CXXDefaultInitExprClass:
3701    mangleExpression(cast<CXXDefaultInitExpr>(E)->getExpr(), Arity);
3702    break;
3703
3704  case Expr::CXXStdInitializerListExprClass:
3705    mangleExpression(cast<CXXStdInitializerListExpr>(E)->getSubExpr(), Arity);
3706    break;
3707
3708  case Expr::SubstNonTypeTemplateParmExprClass:
3709    mangleExpression(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement(),
3710                     Arity);
3711    break;
3712
3713  case Expr::UserDefinedLiteralClass:
3714    // We follow g++'s approach of mangling a UDL as a call to the literal
3715    // operator.
3716  case Expr::CXXMemberCallExprClass: // fallthrough
3717  case Expr::CallExprClass: {
3718    const CallExpr *CE = cast<CallExpr>(E);
3719
3720    // <expression> ::= cp <simple-id> <expression>* E
3721    // We use this mangling only when the call would use ADL except
3722    // for being parenthesized.  Per discussion with David
3723    // Vandervoorde, 2011.04.25.
3724    if (isParenthesizedADLCallee(CE)) {
3725      Out << "cp";
3726      // The callee here is a parenthesized UnresolvedLookupExpr with
3727      // no qualifier and should always get mangled as a <simple-id>
3728      // anyway.
3729
3730    // <expression> ::= cl <expression>* E
3731    } else {
3732      Out << "cl";
3733    }
3734
3735    unsigned CallArity = CE->getNumArgs();
3736    for (const Expr *Arg : CE->arguments())
3737      if (isa<PackExpansionExpr>(Arg))
3738        CallArity = UnknownArity;
3739
3740    mangleExpression(CE->getCallee(), CallArity);
3741    for (const Expr *Arg : CE->arguments())
3742      mangleExpression(Arg);
3743    Out << 'E';
3744    break;
3745  }
3746
3747  case Expr::CXXNewExprClass: {
3748    const CXXNewExpr *New = cast<CXXNewExpr>(E);
3749    if (New->isGlobalNew()) Out << "gs";
3750    Out << (New->isArray() ? "na" : "nw");
3751    for (CXXNewExpr::const_arg_iterator I = New->placement_arg_begin(),
3752           E = New->placement_arg_end(); I != E; ++I)
3753      mangleExpression(*I);
3754    Out << '_';
3755    mangleType(New->getAllocatedType());
3756    if (New->hasInitializer()) {
3757      if (New->getInitializationStyle() == CXXNewExpr::ListInit)
3758        Out << "il";
3759      else
3760        Out << "pi";
3761      const Expr *Init = New->getInitializer();
3762      if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) {
3763        // Directly inline the initializers.
3764        for (CXXConstructExpr::const_arg_iterator I = CCE->arg_begin(),
3765                                                  E = CCE->arg_end();
3766             I != E; ++I)
3767          mangleExpression(*I);
3768      } else if (const ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init)) {
3769        for (unsigned i = 0, e = PLE->getNumExprs(); i != e; ++i)
3770          mangleExpression(PLE->getExpr(i));
3771      } else if (New->getInitializationStyle() == CXXNewExpr::ListInit &&
3772                 isa<InitListExpr>(Init)) {
3773        // Only take InitListExprs apart for list-initialization.
3774        mangleInitListElements(cast<InitListExpr>(Init));
3775      } else
3776        mangleExpression(Init);
3777    }
3778    Out << 'E';
3779    break;
3780  }
3781
3782  case Expr::CXXPseudoDestructorExprClass: {
3783    const auto *PDE = cast<CXXPseudoDestructorExpr>(E);
3784    if (const Expr *Base = PDE->getBase())
3785      mangleMemberExprBase(Base, PDE->isArrow());
3786    NestedNameSpecifier *Qualifier = PDE->getQualifier();
3787    if (TypeSourceInfo *ScopeInfo = PDE->getScopeTypeInfo()) {
3788      if (Qualifier) {
3789        mangleUnresolvedPrefix(Qualifier,
3790                               /*recursive=*/true);
3791        mangleUnresolvedTypeOrSimpleId(ScopeInfo->getType());
3792        Out << 'E';
3793      } else {
3794        Out << "sr";
3795        if (!mangleUnresolvedTypeOrSimpleId(ScopeInfo->getType()))
3796          Out << 'E';
3797      }
3798    } else if (Qualifier) {
3799      mangleUnresolvedPrefix(Qualifier);
3800    }
3801    // <base-unresolved-name> ::= dn <destructor-name>
3802    Out << "dn";
3803    QualType DestroyedType = PDE->getDestroyedType();
3804    mangleUnresolvedTypeOrSimpleId(DestroyedType);
3805    break;
3806  }
3807
3808  case Expr::MemberExprClass: {
3809    const MemberExpr *ME = cast<MemberExpr>(E);
3810    mangleMemberExpr(ME->getBase(), ME->isArrow(),
3811                     ME->getQualifier(), nullptr,
3812                     ME->getMemberDecl()->getDeclName(),
3813                     ME->getTemplateArgs(), ME->getNumTemplateArgs(),
3814                     Arity);
3815    break;
3816  }
3817
3818  case Expr::UnresolvedMemberExprClass: {
3819    const UnresolvedMemberExpr *ME = cast<UnresolvedMemberExpr>(E);
3820    mangleMemberExpr(ME->isImplicitAccess() ? nullptr : ME->getBase(),
3821                     ME->isArrow(), ME->getQualifier(), nullptr,
3822                     ME->getMemberName(),
3823                     ME->getTemplateArgs(), ME->getNumTemplateArgs(),
3824                     Arity);
3825    break;
3826  }
3827
3828  case Expr::CXXDependentScopeMemberExprClass: {
3829    const CXXDependentScopeMemberExpr *ME
3830      = cast<CXXDependentScopeMemberExpr>(E);
3831    mangleMemberExpr(ME->isImplicitAccess() ? nullptr : ME->getBase(),
3832                     ME->isArrow(), ME->getQualifier(),
3833                     ME->getFirstQualifierFoundInScope(),
3834                     ME->getMember(),
3835                     ME->getTemplateArgs(), ME->getNumTemplateArgs(),
3836                     Arity);
3837    break;
3838  }
3839
3840  case Expr::UnresolvedLookupExprClass: {
3841    const UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(E);
3842    mangleUnresolvedName(ULE->getQualifier(), ULE->getName(),
3843                         ULE->getTemplateArgs(), ULE->getNumTemplateArgs(),
3844                         Arity);
3845    break;
3846  }
3847
3848  case Expr::CXXUnresolvedConstructExprClass: {
3849    const CXXUnresolvedConstructExpr *CE = cast<CXXUnresolvedConstructExpr>(E);
3850    unsigned N = CE->arg_size();
3851
3852    if (CE->isListInitialization()) {
3853      assert(N == 1 && "unexpected form for list initialization");
3854      auto *IL = cast<InitListExpr>(CE->getArg(0));
3855      Out << "tl";
3856      mangleType(CE->getType());
3857      mangleInitListElements(IL);
3858      Out << "E";
3859      return;
3860    }
3861
3862    Out << "cv";
3863    mangleType(CE->getType());
3864    if (N != 1) Out << '_';
3865    for (unsigned I = 0; I != N; ++I) mangleExpression(CE->getArg(I));
3866    if (N != 1) Out << 'E';
3867    break;
3868  }
3869
3870  case Expr::CXXConstructExprClass: {
3871    const auto *CE = cast<CXXConstructExpr>(E);
3872    if (!CE->isListInitialization() || CE->isStdInitListInitialization()) {
3873      assert(
3874          CE->getNumArgs() >= 1 &&
3875          (CE->getNumArgs() == 1 || isa<CXXDefaultArgExpr>(CE->getArg(1))) &&
3876          "implicit CXXConstructExpr must have one argument");
3877      return mangleExpression(cast<CXXConstructExpr>(E)->getArg(0));
3878    }
3879    Out << "il";
3880    for (auto *E : CE->arguments())
3881      mangleExpression(E);
3882    Out << "E";
3883    break;
3884  }
3885
3886  case Expr::CXXTemporaryObjectExprClass: {
3887    const auto *CE = cast<CXXTemporaryObjectExpr>(E);
3888    unsigned N = CE->getNumArgs();
3889    bool List = CE->isListInitialization();
3890
3891    if (List)
3892      Out << "tl";
3893    else
3894      Out << "cv";
3895    mangleType(CE->getType());
3896    if (!List && N != 1)
3897      Out << '_';
3898    if (CE->isStdInitListInitialization()) {
3899      // We implicitly created a std::initializer_list<T> for the first argument
3900      // of a constructor of type U in an expression of the form U{a, b, c}.
3901      // Strip all the semantic gunk off the initializer list.
3902      auto *SILE =
3903          cast<CXXStdInitializerListExpr>(CE->getArg(0)->IgnoreImplicit());
3904      auto *ILE = cast<InitListExpr>(SILE->getSubExpr()->IgnoreImplicit());
3905      mangleInitListElements(ILE);
3906    } else {
3907      for (auto *E : CE->arguments())
3908        mangleExpression(E);
3909    }
3910    if (List || N != 1)
3911      Out << 'E';
3912    break;
3913  }
3914
3915  case Expr::CXXScalarValueInitExprClass:
3916    Out << "cv";
3917    mangleType(E->getType());
3918    Out << "_E";
3919    break;
3920
3921  case Expr::CXXNoexceptExprClass:
3922    Out << "nx";
3923    mangleExpression(cast<CXXNoexceptExpr>(E)->getOperand());
3924    break;
3925
3926  case Expr::UnaryExprOrTypeTraitExprClass: {
3927    const UnaryExprOrTypeTraitExpr *SAE = cast<UnaryExprOrTypeTraitExpr>(E);
3928
3929    if (!SAE->isInstantiationDependent()) {
3930      // Itanium C++ ABI:
3931      //   If the operand of a sizeof or alignof operator is not
3932      //   instantiation-dependent it is encoded as an integer literal
3933      //   reflecting the result of the operator.
3934      //
3935      //   If the result of the operator is implicitly converted to a known
3936      //   integer type, that type is used for the literal; otherwise, the type
3937      //   of std::size_t or std::ptrdiff_t is used.
3938      QualType T = (ImplicitlyConvertedToType.isNull() ||
3939                    !ImplicitlyConvertedToType->isIntegerType())? SAE->getType()
3940                                                    : ImplicitlyConvertedToType;
3941      llvm::APSInt V = SAE->EvaluateKnownConstInt(Context.getASTContext());
3942      mangleIntegerLiteral(T, V);
3943      break;
3944    }
3945
3946    switch(SAE->getKind()) {
3947    case UETT_SizeOf:
3948      Out << 's';
3949      break;
3950    case UETT_PreferredAlignOf:
3951    case UETT_AlignOf:
3952      Out << 'a';
3953      break;
3954    case UETT_VecStep: {
3955      DiagnosticsEngine &Diags = Context.getDiags();
3956      unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
3957                                     "cannot yet mangle vec_step expression");
3958      Diags.Report(DiagID);
3959      return;
3960    }
3961    case UETT_OpenMPRequiredSimdAlign: {
3962      DiagnosticsEngine &Diags = Context.getDiags();
3963      unsigned DiagID = Diags.getCustomDiagID(
3964          DiagnosticsEngine::Error,
3965          "cannot yet mangle __builtin_omp_required_simd_align expression");
3966      Diags.Report(DiagID);
3967      return;
3968    }
3969    }
3970    if (SAE->isArgumentType()) {
3971      Out << 't';
3972      mangleType(SAE->getArgumentType());
3973    } else {
3974      Out << 'z';
3975      mangleExpression(SAE->getArgumentExpr());
3976    }
3977    break;
3978  }
3979
3980  case Expr::CXXThrowExprClass: {
3981    const CXXThrowExpr *TE = cast<CXXThrowExpr>(E);
3982    //  <expression> ::= tw <expression>  # throw expression
3983    //               ::= tr               # rethrow
3984    if (TE->getSubExpr()) {
3985      Out << "tw";
3986      mangleExpression(TE->getSubExpr());
3987    } else {
3988      Out << "tr";
3989    }
3990    break;
3991  }
3992
3993  case Expr::CXXTypeidExprClass: {
3994    const CXXTypeidExpr *TIE = cast<CXXTypeidExpr>(E);
3995    //  <expression> ::= ti <type>        # typeid (type)
3996    //               ::= te <expression>  # typeid (expression)
3997    if (TIE->isTypeOperand()) {
3998      Out << "ti";
3999      mangleType(TIE->getTypeOperand(Context.getASTContext()));
4000    } else {
4001      Out << "te";
4002      mangleExpression(TIE->getExprOperand());
4003    }
4004    break;
4005  }
4006
4007  case Expr::CXXDeleteExprClass: {
4008    const CXXDeleteExpr *DE = cast<CXXDeleteExpr>(E);
4009    //  <expression> ::= [gs] dl <expression>  # [::] delete expr
4010    //               ::= [gs] da <expression>  # [::] delete [] expr
4011    if (DE->isGlobalDelete()) Out << "gs";
4012    Out << (DE->isArrayForm() ? "da" : "dl");
4013    mangleExpression(DE->getArgument());
4014    break;
4015  }
4016
4017  case Expr::UnaryOperatorClass: {
4018    const UnaryOperator *UO = cast<UnaryOperator>(E);
4019    mangleOperatorName(UnaryOperator::getOverloadedOperator(UO->getOpcode()),
4020                       /*Arity=*/1);
4021    mangleExpression(UO->getSubExpr());
4022    break;
4023  }
4024
4025  case Expr::ArraySubscriptExprClass: {
4026    const ArraySubscriptExpr *AE = cast<ArraySubscriptExpr>(E);
4027
4028    // Array subscript is treated as a syntactically weird form of
4029    // binary operator.
4030    Out << "ix";
4031    mangleExpression(AE->getLHS());
4032    mangleExpression(AE->getRHS());
4033    break;
4034  }
4035
4036  case Expr::CompoundAssignOperatorClass: // fallthrough
4037  case Expr::BinaryOperatorClass: {
4038    const BinaryOperator *BO = cast<BinaryOperator>(E);
4039    if (BO->getOpcode() == BO_PtrMemD)
4040      Out << "ds";
4041    else
4042      mangleOperatorName(BinaryOperator::getOverloadedOperator(BO->getOpcode()),
4043                         /*Arity=*/2);
4044    mangleExpression(BO->getLHS());
4045    mangleExpression(BO->getRHS());
4046    break;
4047  }
4048
4049  case Expr::ConditionalOperatorClass: {
4050    const ConditionalOperator *CO = cast<ConditionalOperator>(E);
4051    mangleOperatorName(OO_Conditional, /*Arity=*/3);
4052    mangleExpression(CO->getCond());
4053    mangleExpression(CO->getLHS(), Arity);
4054    mangleExpression(CO->getRHS(), Arity);
4055    break;
4056  }
4057
4058  case Expr::ImplicitCastExprClass: {
4059    ImplicitlyConvertedToType = E->getType();
4060    E = cast<ImplicitCastExpr>(E)->getSubExpr();
4061    goto recurse;
4062  }
4063
4064  case Expr::ObjCBridgedCastExprClass: {
4065    // Mangle ownership casts as a vendor extended operator __bridge,
4066    // __bridge_transfer, or __bridge_retain.
4067    StringRef Kind = cast<ObjCBridgedCastExpr>(E)->getBridgeKindName();
4068    Out << "v1U" << Kind.size() << Kind;
4069  }
4070  // Fall through to mangle the cast itself.
4071  LLVM_FALLTHROUGH;
4072
4073  case Expr::CStyleCastExprClass:
4074    mangleCastExpression(E, "cv");
4075    break;
4076
4077  case Expr::CXXFunctionalCastExprClass: {
4078    auto *Sub = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreImplicit();
4079    // FIXME: Add isImplicit to CXXConstructExpr.
4080    if (auto *CCE = dyn_cast<CXXConstructExpr>(Sub))
4081      if (CCE->getParenOrBraceRange().isInvalid())
4082        Sub = CCE->getArg(0)->IgnoreImplicit();
4083    if (auto *StdInitList = dyn_cast<CXXStdInitializerListExpr>(Sub))
4084      Sub = StdInitList->getSubExpr()->IgnoreImplicit();
4085    if (auto *IL = dyn_cast<InitListExpr>(Sub)) {
4086      Out << "tl";
4087      mangleType(E->getType());
4088      mangleInitListElements(IL);
4089      Out << "E";
4090    } else {
4091      mangleCastExpression(E, "cv");
4092    }
4093    break;
4094  }
4095
4096  case Expr::CXXStaticCastExprClass:
4097    mangleCastExpression(E, "sc");
4098    break;
4099  case Expr::CXXDynamicCastExprClass:
4100    mangleCastExpression(E, "dc");
4101    break;
4102  case Expr::CXXReinterpretCastExprClass:
4103    mangleCastExpression(E, "rc");
4104    break;
4105  case Expr::CXXConstCastExprClass:
4106    mangleCastExpression(E, "cc");
4107    break;
4108
4109  case Expr::CXXOperatorCallExprClass: {
4110    const CXXOperatorCallExpr *CE = cast<CXXOperatorCallExpr>(E);
4111    unsigned NumArgs = CE->getNumArgs();
4112    // A CXXOperatorCallExpr for OO_Arrow models only semantics, not syntax
4113    // (the enclosing MemberExpr covers the syntactic portion).
4114    if (CE->getOperator() != OO_Arrow)
4115      mangleOperatorName(CE->getOperator(), /*Arity=*/NumArgs);
4116    // Mangle the arguments.
4117    for (unsigned i = 0; i != NumArgs; ++i)
4118      mangleExpression(CE->getArg(i));
4119    break;
4120  }
4121
4122  case Expr::ParenExprClass:
4123    mangleExpression(cast<ParenExpr>(E)->getSubExpr(), Arity);
4124    break;
4125
4126  case Expr::DeclRefExprClass:
4127    mangleDeclRefExpr(cast<DeclRefExpr>(E)->getDecl());
4128    break;
4129
4130  case Expr::SubstNonTypeTemplateParmPackExprClass:
4131    // FIXME: not clear how to mangle this!
4132    // template <unsigned N...> class A {
4133    //   template <class U...> void foo(U (&x)[N]...);
4134    // };
4135    Out << "_SUBSTPACK_";
4136    break;
4137
4138  case Expr::FunctionParmPackExprClass: {
4139    // FIXME: not clear how to mangle this!
4140    const FunctionParmPackExpr *FPPE = cast<FunctionParmPackExpr>(E);
4141    Out << "v110_SUBSTPACK";
4142    mangleDeclRefExpr(FPPE->getParameterPack());
4143    break;
4144  }
4145
4146  case Expr::DependentScopeDeclRefExprClass: {
4147    const DependentScopeDeclRefExpr *DRE = cast<DependentScopeDeclRefExpr>(E);
4148    mangleUnresolvedName(DRE->getQualifier(), DRE->getDeclName(),
4149                         DRE->getTemplateArgs(), DRE->getNumTemplateArgs(),
4150                         Arity);
4151    break;
4152  }
4153
4154  case Expr::CXXBindTemporaryExprClass:
4155    mangleExpression(cast<CXXBindTemporaryExpr>(E)->getSubExpr());
4156    break;
4157
4158  case Expr::ExprWithCleanupsClass:
4159    mangleExpression(cast<ExprWithCleanups>(E)->getSubExpr(), Arity);
4160    break;
4161
4162  case Expr::FloatingLiteralClass: {
4163    const FloatingLiteral *FL = cast<FloatingLiteral>(E);
4164    Out << 'L';
4165    mangleType(FL->getType());
4166    mangleFloat(FL->getValue());
4167    Out << 'E';
4168    break;
4169  }
4170
4171  case Expr::CharacterLiteralClass:
4172    Out << 'L';
4173    mangleType(E->getType());
4174    Out << cast<CharacterLiteral>(E)->getValue();
4175    Out << 'E';
4176    break;
4177
4178  // FIXME. __objc_yes/__objc_no are mangled same as true/false
4179  case Expr::ObjCBoolLiteralExprClass:
4180    Out << "Lb";
4181    Out << (cast<ObjCBoolLiteralExpr>(E)->getValue() ? '1' : '0');
4182    Out << 'E';
4183    break;
4184
4185  case Expr::CXXBoolLiteralExprClass:
4186    Out << "Lb";
4187    Out << (cast<CXXBoolLiteralExpr>(E)->getValue() ? '1' : '0');
4188    Out << 'E';
4189    break;
4190
4191  case Expr::IntegerLiteralClass: {
4192    llvm::APSInt Value(cast<IntegerLiteral>(E)->getValue());
4193    if (E->getType()->isSignedIntegerType())
4194      Value.setIsSigned(true);
4195    mangleIntegerLiteral(E->getType(), Value);
4196    break;
4197  }
4198
4199  case Expr::ImaginaryLiteralClass: {
4200    const ImaginaryLiteral *IE = cast<ImaginaryLiteral>(E);
4201    // Mangle as if a complex literal.
4202    // Proposal from David Vandevoorde, 2010.06.30.
4203    Out << 'L';
4204    mangleType(E->getType());
4205    if (const FloatingLiteral *Imag =
4206          dyn_cast<FloatingLiteral>(IE->getSubExpr())) {
4207      // Mangle a floating-point zero of the appropriate type.
4208      mangleFloat(llvm::APFloat(Imag->getValue().getSemantics()));
4209      Out << '_';
4210      mangleFloat(Imag->getValue());
4211    } else {
4212      Out << "0_";
4213      llvm::APSInt Value(cast<IntegerLiteral>(IE->getSubExpr())->getValue());
4214      if (IE->getSubExpr()->getType()->isSignedIntegerType())
4215        Value.setIsSigned(true);
4216      mangleNumber(Value);
4217    }
4218    Out << 'E';
4219    break;
4220  }
4221
4222  case Expr::StringLiteralClass: {
4223    // Revised proposal from David Vandervoorde, 2010.07.15.
4224    Out << 'L';
4225    assert(isa<ConstantArrayType>(E->getType()));
4226    mangleType(E->getType());
4227    Out << 'E';
4228    break;
4229  }
4230
4231  case Expr::GNUNullExprClass:
4232    // FIXME: should this really be mangled the same as nullptr?
4233    // fallthrough
4234
4235  case Expr::CXXNullPtrLiteralExprClass: {
4236    Out << "LDnE";
4237    break;
4238  }
4239
4240  case Expr::PackExpansionExprClass:
4241    Out << "sp";
4242    mangleExpression(cast<PackExpansionExpr>(E)->getPattern());
4243    break;
4244
4245  case Expr::SizeOfPackExprClass: {
4246    auto *SPE = cast<SizeOfPackExpr>(E);
4247    if (SPE->isPartiallySubstituted()) {
4248      Out << "sP";
4249      for (const auto &A : SPE->getPartialArguments())
4250        mangleTemplateArg(A);
4251      Out << "E";
4252      break;
4253    }
4254
4255    Out << "sZ";
4256    const NamedDecl *Pack = SPE->getPack();
4257    if (const TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Pack))
4258      mangleTemplateParameter(TTP->getIndex());
4259    else if (const NonTypeTemplateParmDecl *NTTP
4260                = dyn_cast<NonTypeTemplateParmDecl>(Pack))
4261      mangleTemplateParameter(NTTP->getIndex());
4262    else if (const TemplateTemplateParmDecl *TempTP
4263                                    = dyn_cast<TemplateTemplateParmDecl>(Pack))
4264      mangleTemplateParameter(TempTP->getIndex());
4265    else
4266      mangleFunctionParam(cast<ParmVarDecl>(Pack));
4267    break;
4268  }
4269
4270  case Expr::MaterializeTemporaryExprClass: {
4271    mangleExpression(cast<MaterializeTemporaryExpr>(E)->GetTemporaryExpr());
4272    break;
4273  }
4274
4275  case Expr::CXXFoldExprClass: {
4276    auto *FE = cast<CXXFoldExpr>(E);
4277    if (FE->isLeftFold())
4278      Out << (FE->getInit() ? "fL" : "fl");
4279    else
4280      Out << (FE->getInit() ? "fR" : "fr");
4281
4282    if (FE->getOperator() == BO_PtrMemD)
4283      Out << "ds";
4284    else
4285      mangleOperatorName(
4286          BinaryOperator::getOverloadedOperator(FE->getOperator()),
4287          /*Arity=*/2);
4288
4289    if (FE->getLHS())
4290      mangleExpression(FE->getLHS());
4291    if (FE->getRHS())
4292      mangleExpression(FE->getRHS());
4293    break;
4294  }
4295
4296  case Expr::CXXThisExprClass:
4297    Out << "fpT";
4298    break;
4299
4300  case Expr::CoawaitExprClass:
4301    // FIXME: Propose a non-vendor mangling.
4302    Out << "v18co_await";
4303    mangleExpression(cast<CoawaitExpr>(E)->getOperand());
4304    break;
4305
4306  case Expr::DependentCoawaitExprClass:
4307    // FIXME: Propose a non-vendor mangling.
4308    Out << "v18co_await";
4309    mangleExpression(cast<DependentCoawaitExpr>(E)->getOperand());
4310    break;
4311
4312  case Expr::CoyieldExprClass:
4313    // FIXME: Propose a non-vendor mangling.
4314    Out << "v18co_yield";
4315    mangleExpression(cast<CoawaitExpr>(E)->getOperand());
4316    break;
4317  }
4318}
4319
4320/// Mangle an expression which refers to a parameter variable.
4321///
4322/// <expression>     ::= <function-param>
4323/// <function-param> ::= fp <top-level CV-qualifiers> _      # L == 0, I == 0
4324/// <function-param> ::= fp <top-level CV-qualifiers>
4325///                      <parameter-2 non-negative number> _ # L == 0, I > 0
4326/// <function-param> ::= fL <L-1 non-negative number>
4327///                      p <top-level CV-qualifiers> _       # L > 0, I == 0
4328/// <function-param> ::= fL <L-1 non-negative number>
4329///                      p <top-level CV-qualifiers>
4330///                      <I-1 non-negative number> _         # L > 0, I > 0
4331///
4332/// L is the nesting depth of the parameter, defined as 1 if the
4333/// parameter comes from the innermost function prototype scope
4334/// enclosing the current context, 2 if from the next enclosing
4335/// function prototype scope, and so on, with one special case: if
4336/// we've processed the full parameter clause for the innermost
4337/// function type, then L is one less.  This definition conveniently
4338/// makes it irrelevant whether a function's result type was written
4339/// trailing or leading, but is otherwise overly complicated; the
4340/// numbering was first designed without considering references to
4341/// parameter in locations other than return types, and then the
4342/// mangling had to be generalized without changing the existing
4343/// manglings.
4344///
4345/// I is the zero-based index of the parameter within its parameter
4346/// declaration clause.  Note that the original ABI document describes
4347/// this using 1-based ordinals.
4348void CXXNameMangler::mangleFunctionParam(const ParmVarDecl *parm) {
4349  unsigned parmDepth = parm->getFunctionScopeDepth();
4350  unsigned parmIndex = parm->getFunctionScopeIndex();
4351
4352  // Compute 'L'.
4353  // parmDepth does not include the declaring function prototype.
4354  // FunctionTypeDepth does account for that.
4355  assert(parmDepth < FunctionTypeDepth.getDepth());
4356  unsigned nestingDepth = FunctionTypeDepth.getDepth() - parmDepth;
4357  if (FunctionTypeDepth.isInResultType())
4358    nestingDepth--;
4359
4360  if (nestingDepth == 0) {
4361    Out << "fp";
4362  } else {
4363    Out << "fL" << (nestingDepth - 1) << 'p';
4364  }
4365
4366  // Top-level qualifiers.  We don't have to worry about arrays here,
4367  // because parameters declared as arrays should already have been
4368  // transformed to have pointer type. FIXME: apparently these don't
4369  // get mangled if used as an rvalue of a known non-class type?
4370  assert(!parm->getType()->isArrayType()
4371         && "parameter's type is still an array type?");
4372
4373  if (const DependentAddressSpaceType *DAST =
4374      dyn_cast<DependentAddressSpaceType>(parm->getType())) {
4375    mangleQualifiers(DAST->getPointeeType().getQualifiers(), DAST);
4376  } else {
4377    mangleQualifiers(parm->getType().getQualifiers());
4378  }
4379
4380  // Parameter index.
4381  if (parmIndex != 0) {
4382    Out << (parmIndex - 1);
4383  }
4384  Out << '_';
4385}
4386
4387void CXXNameMangler::mangleCXXCtorType(CXXCtorType T,
4388                                       const CXXRecordDecl *InheritedFrom) {
4389  // <ctor-dtor-name> ::= C1  # complete object constructor
4390  //                  ::= C2  # base object constructor
4391  //                  ::= CI1 <type> # complete inheriting constructor
4392  //                  ::= CI2 <type> # base inheriting constructor
4393  //
4394  // In addition, C5 is a comdat name with C1 and C2 in it.
4395  Out << 'C';
4396  if (InheritedFrom)
4397    Out << 'I';
4398  switch (T) {
4399  case Ctor_Complete:
4400    Out << '1';
4401    break;
4402  case Ctor_Base:
4403    Out << '2';
4404    break;
4405  case Ctor_Comdat:
4406    Out << '5';
4407    break;
4408  case Ctor_DefaultClosure:
4409  case Ctor_CopyingClosure:
4410    llvm_unreachable("closure constructors don't exist for the Itanium ABI!");
4411  }
4412  if (InheritedFrom)
4413    mangleName(InheritedFrom);
4414}
4415
4416void CXXNameMangler::mangleCXXDtorType(CXXDtorType T) {
4417  // <ctor-dtor-name> ::= D0  # deleting destructor
4418  //                  ::= D1  # complete object destructor
4419  //                  ::= D2  # base object destructor
4420  //
4421  // In addition, D5 is a comdat name with D1, D2 and, if virtual, D0 in it.
4422  switch (T) {
4423  case Dtor_Deleting:
4424    Out << "D0";
4425    break;
4426  case Dtor_Complete:
4427    Out << "D1";
4428    break;
4429  case Dtor_Base:
4430    Out << "D2";
4431    break;
4432  case Dtor_Comdat:
4433    Out << "D5";
4434    break;
4435  }
4436}
4437
4438void CXXNameMangler::mangleTemplateArgs(const TemplateArgumentLoc *TemplateArgs,
4439                                        unsigned NumTemplateArgs) {
4440  // <template-args> ::= I <template-arg>+ E
4441  Out << 'I';
4442  for (unsigned i = 0; i != NumTemplateArgs; ++i)
4443    mangleTemplateArg(TemplateArgs[i].getArgument());
4444  Out << 'E';
4445}
4446
4447void CXXNameMangler::mangleTemplateArgs(const TemplateArgumentList &AL) {
4448  // <template-args> ::= I <template-arg>+ E
4449  Out << 'I';
4450  for (unsigned i = 0, e = AL.size(); i != e; ++i)
4451    mangleTemplateArg(AL[i]);
4452  Out << 'E';
4453}
4454
4455void CXXNameMangler::mangleTemplateArgs(const TemplateArgument *TemplateArgs,
4456                                        unsigned NumTemplateArgs) {
4457  // <template-args> ::= I <template-arg>+ E
4458  Out << 'I';
4459  for (unsigned i = 0; i != NumTemplateArgs; ++i)
4460    mangleTemplateArg(TemplateArgs[i]);
4461  Out << 'E';
4462}
4463
4464void CXXNameMangler::mangleTemplateArg(TemplateArgument A) {
4465  // <template-arg> ::= <type>              # type or template
4466  //                ::= X <expression> E    # expression
4467  //                ::= <expr-primary>      # simple expressions
4468  //                ::= J <template-arg>* E # argument pack
4469  if (!A.isInstantiationDependent() || A.isDependent())
4470    A = Context.getASTContext().getCanonicalTemplateArgument(A);
4471
4472  switch (A.getKind()) {
4473  case TemplateArgument::Null:
4474    llvm_unreachable("Cannot mangle NULL template argument");
4475
4476  case TemplateArgument::Type:
4477    mangleType(A.getAsType());
4478    break;
4479  case TemplateArgument::Template:
4480    // This is mangled as <type>.
4481    mangleType(A.getAsTemplate());
4482    break;
4483  case TemplateArgument::TemplateExpansion:
4484    // <type>  ::= Dp <type>          # pack expansion (C++0x)
4485    Out << "Dp";
4486    mangleType(A.getAsTemplateOrTemplatePattern());
4487    break;
4488  case TemplateArgument::Expression: {
4489    // It's possible to end up with a DeclRefExpr here in certain
4490    // dependent cases, in which case we should mangle as a
4491    // declaration.
4492    const Expr *E = A.getAsExpr()->IgnoreParenImpCasts();
4493    if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
4494      const ValueDecl *D = DRE->getDecl();
4495      if (isa<VarDecl>(D) || isa<FunctionDecl>(D)) {
4496        Out << 'L';
4497        mangle(D);
4498        Out << 'E';
4499        break;
4500      }
4501    }
4502
4503    Out << 'X';
4504    mangleExpression(E);
4505    Out << 'E';
4506    break;
4507  }
4508  case TemplateArgument::Integral:
4509    mangleIntegerLiteral(A.getIntegralType(), A.getAsIntegral());
4510    break;
4511  case TemplateArgument::Declaration: {
4512    //  <expr-primary> ::= L <mangled-name> E # external name
4513    // Clang produces AST's where pointer-to-member-function expressions
4514    // and pointer-to-function expressions are represented as a declaration not
4515    // an expression. We compensate for it here to produce the correct mangling.
4516    ValueDecl *D = A.getAsDecl();
4517    bool compensateMangling = !A.getParamTypeForDecl()->isReferenceType();
4518    if (compensateMangling) {
4519      Out << 'X';
4520      mangleOperatorName(OO_Amp, 1);
4521    }
4522
4523    Out << 'L';
4524    // References to external entities use the mangled name; if the name would
4525    // not normally be mangled then mangle it as unqualified.
4526    mangle(D);
4527    Out << 'E';
4528
4529    if (compensateMangling)
4530      Out << 'E';
4531
4532    break;
4533  }
4534  case TemplateArgument::NullPtr: {
4535    //  <expr-primary> ::= L <type> 0 E
4536    Out << 'L';
4537    mangleType(A.getNullPtrType());
4538    Out << "0E";
4539    break;
4540  }
4541  case TemplateArgument::Pack: {
4542    //  <template-arg> ::= J <template-arg>* E
4543    Out << 'J';
4544    for (const auto &P : A.pack_elements())
4545      mangleTemplateArg(P);
4546    Out << 'E';
4547  }
4548  }
4549}
4550
4551void CXXNameMangler::mangleTemplateParameter(unsigned Index) {
4552  // <template-param> ::= T_    # first template parameter
4553  //                  ::= T <parameter-2 non-negative number> _
4554  if (Index == 0)
4555    Out << "T_";
4556  else
4557    Out << 'T' << (Index - 1) << '_';
4558}
4559
4560void CXXNameMangler::mangleSeqID(unsigned SeqID) {
4561  if (SeqID == 1)
4562    Out << '0';
4563  else if (SeqID > 1) {
4564    SeqID--;
4565
4566    // <seq-id> is encoded in base-36, using digits and upper case letters.
4567    char Buffer[7]; // log(2**32) / log(36) ~= 7
4568    MutableArrayRef<char> BufferRef(Buffer);
4569    MutableArrayRef<char>::reverse_iterator I = BufferRef.rbegin();
4570
4571    for (; SeqID != 0; SeqID /= 36) {
4572      unsigned C = SeqID % 36;
4573      *I++ = (C < 10 ? '0' + C : 'A' + C - 10);
4574    }
4575
4576    Out.write(I.base(), I - BufferRef.rbegin());
4577  }
4578  Out << '_';
4579}
4580
4581void CXXNameMangler::mangleExistingSubstitution(TemplateName tname) {
4582  bool result = mangleSubstitution(tname);
4583  assert(result && "no existing substitution for template name");
4584  (void) result;
4585}
4586
4587// <substitution> ::= S <seq-id> _
4588//                ::= S_
4589bool CXXNameMangler::mangleSubstitution(const NamedDecl *ND) {
4590  // Try one of the standard substitutions first.
4591  if (mangleStandardSubstitution(ND))
4592    return true;
4593
4594  ND = cast<NamedDecl>(ND->getCanonicalDecl());
4595  return mangleSubstitution(reinterpret_cast<uintptr_t>(ND));
4596}
4597
4598/// Determine whether the given type has any qualifiers that are relevant for
4599/// substitutions.
4600static bool hasMangledSubstitutionQualifiers(QualType T) {
4601  Qualifiers Qs = T.getQualifiers();
4602  return Qs.getCVRQualifiers() || Qs.hasAddressSpace() || Qs.hasUnaligned();
4603}
4604
4605bool CXXNameMangler::mangleSubstitution(QualType T) {
4606  if (!hasMangledSubstitutionQualifiers(T)) {
4607    if (const RecordType *RT = T->getAs<RecordType>())
4608      return mangleSubstitution(RT->getDecl());
4609  }
4610
4611  uintptr_t TypePtr = reinterpret_cast<uintptr_t>(T.getAsOpaquePtr());
4612
4613  return mangleSubstitution(TypePtr);
4614}
4615
4616bool CXXNameMangler::mangleSubstitution(TemplateName Template) {
4617  if (TemplateDecl *TD = Template.getAsTemplateDecl())
4618    return mangleSubstitution(TD);
4619
4620  Template = Context.getASTContext().getCanonicalTemplateName(Template);
4621  return mangleSubstitution(
4622                      reinterpret_cast<uintptr_t>(Template.getAsVoidPointer()));
4623}
4624
4625bool CXXNameMangler::mangleSubstitution(uintptr_t Ptr) {
4626  llvm::DenseMap<uintptr_t, unsigned>::iterator I = Substitutions.find(Ptr);
4627  if (I == Substitutions.end())
4628    return false;
4629
4630  unsigned SeqID = I->second;
4631  Out << 'S';
4632  mangleSeqID(SeqID);
4633
4634  return true;
4635}
4636
4637static bool isCharType(QualType T) {
4638  if (T.isNull())
4639    return false;
4640
4641  return T->isSpecificBuiltinType(BuiltinType::Char_S) ||
4642    T->isSpecificBuiltinType(BuiltinType::Char_U);
4643}
4644
4645/// Returns whether a given type is a template specialization of a given name
4646/// with a single argument of type char.
4647static bool isCharSpecialization(QualType T, const char *Name) {
4648  if (T.isNull())
4649    return false;
4650
4651  const RecordType *RT = T->getAs<RecordType>();
4652  if (!RT)
4653    return false;
4654
4655  const ClassTemplateSpecializationDecl *SD =
4656    dyn_cast<ClassTemplateSpecializationDecl>(RT->getDecl());
4657  if (!SD)
4658    return false;
4659
4660  if (!isStdNamespace(getEffectiveDeclContext(SD)))
4661    return false;
4662
4663  const TemplateArgumentList &TemplateArgs = SD->getTemplateArgs();
4664  if (TemplateArgs.size() != 1)
4665    return false;
4666
4667  if (!isCharType(TemplateArgs[0].getAsType()))
4668    return false;
4669
4670  return SD->getIdentifier()->getName() == Name;
4671}
4672
4673template <std::size_t StrLen>
4674static bool isStreamCharSpecialization(const ClassTemplateSpecializationDecl*SD,
4675                                       const char (&Str)[StrLen]) {
4676  if (!SD->getIdentifier()->isStr(Str))
4677    return false;
4678
4679  const TemplateArgumentList &TemplateArgs = SD->getTemplateArgs();
4680  if (TemplateArgs.size() != 2)
4681    return false;
4682
4683  if (!isCharType(TemplateArgs[0].getAsType()))
4684    return false;
4685
4686  if (!isCharSpecialization(TemplateArgs[1].getAsType(), "char_traits"))
4687    return false;
4688
4689  return true;
4690}
4691
4692bool CXXNameMangler::mangleStandardSubstitution(const NamedDecl *ND) {
4693  // <substitution> ::= St # ::std::
4694  if (const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(ND)) {
4695    if (isStd(NS)) {
4696      Out << "St";
4697      return true;
4698    }
4699  }
4700
4701  if (const ClassTemplateDecl *TD = dyn_cast<ClassTemplateDecl>(ND)) {
4702    if (!isStdNamespace(getEffectiveDeclContext(TD)))
4703      return false;
4704
4705    // <substitution> ::= Sa # ::std::allocator
4706    if (TD->getIdentifier()->isStr("allocator")) {
4707      Out << "Sa";
4708      return true;
4709    }
4710
4711    // <<substitution> ::= Sb # ::std::basic_string
4712    if (TD->getIdentifier()->isStr("basic_string")) {
4713      Out << "Sb";
4714      return true;
4715    }
4716  }
4717
4718  if (const ClassTemplateSpecializationDecl *SD =
4719        dyn_cast<ClassTemplateSpecializationDecl>(ND)) {
4720    if (!isStdNamespace(getEffectiveDeclContext(SD)))
4721      return false;
4722
4723    //    <substitution> ::= Ss # ::std::basic_string<char,
4724    //                            ::std::char_traits<char>,
4725    //                            ::std::allocator<char> >
4726    if (SD->getIdentifier()->isStr("basic_string")) {
4727      const TemplateArgumentList &TemplateArgs = SD->getTemplateArgs();
4728
4729      if (TemplateArgs.size() != 3)
4730        return false;
4731
4732      if (!isCharType(TemplateArgs[0].getAsType()))
4733        return false;
4734
4735      if (!isCharSpecialization(TemplateArgs[1].getAsType(), "char_traits"))
4736        return false;
4737
4738      if (!isCharSpecialization(TemplateArgs[2].getAsType(), "allocator"))
4739        return false;
4740
4741      Out << "Ss";
4742      return true;
4743    }
4744
4745    //    <substitution> ::= Si # ::std::basic_istream<char,
4746    //                            ::std::char_traits<char> >
4747    if (isStreamCharSpecialization(SD, "basic_istream")) {
4748      Out << "Si";
4749      return true;
4750    }
4751
4752    //    <substitution> ::= So # ::std::basic_ostream<char,
4753    //                            ::std::char_traits<char> >
4754    if (isStreamCharSpecialization(SD, "basic_ostream")) {
4755      Out << "So";
4756      return true;
4757    }
4758
4759    //    <substitution> ::= Sd # ::std::basic_iostream<char,
4760    //                            ::std::char_traits<char> >
4761    if (isStreamCharSpecialization(SD, "basic_iostream")) {
4762      Out << "Sd";
4763      return true;
4764    }
4765  }
4766  return false;
4767}
4768
4769void CXXNameMangler::addSubstitution(QualType T) {
4770  if (!hasMangledSubstitutionQualifiers(T)) {
4771    if (const RecordType *RT = T->getAs<RecordType>()) {
4772      addSubstitution(RT->getDecl());
4773      return;
4774    }
4775  }
4776
4777  uintptr_t TypePtr = reinterpret_cast<uintptr_t>(T.getAsOpaquePtr());
4778  addSubstitution(TypePtr);
4779}
4780
4781void CXXNameMangler::addSubstitution(TemplateName Template) {
4782  if (TemplateDecl *TD = Template.getAsTemplateDecl())
4783    return addSubstitution(TD);
4784
4785  Template = Context.getASTContext().getCanonicalTemplateName(Template);
4786  addSubstitution(reinterpret_cast<uintptr_t>(Template.getAsVoidPointer()));
4787}
4788
4789void CXXNameMangler::addSubstitution(uintptr_t Ptr) {
4790  assert(!Substitutions.count(Ptr) && "Substitution already exists!");
4791  Substitutions[Ptr] = SeqID++;
4792}
4793
4794void CXXNameMangler::extendSubstitutions(CXXNameMangler* Other) {
4795  assert(Other->SeqID >= SeqID && "Must be superset of substitutions!");
4796  if (Other->SeqID > SeqID) {
4797    Substitutions.swap(Other->Substitutions);
4798    SeqID = Other->SeqID;
4799  }
4800}
4801
4802CXXNameMangler::AbiTagList
4803CXXNameMangler::makeFunctionReturnTypeTags(const FunctionDecl *FD) {
4804  // When derived abi tags are disabled there is no need to make any list.
4805  if (DisableDerivedAbiTags)
4806    return AbiTagList();
4807
4808  llvm::raw_null_ostream NullOutStream;
4809  CXXNameMangler TrackReturnTypeTags(*this, NullOutStream);
4810  TrackReturnTypeTags.disableDerivedAbiTags();
4811
4812  const FunctionProtoType *Proto =
4813      cast<FunctionProtoType>(FD->getType()->getAs<FunctionType>());
4814  FunctionTypeDepthState saved = TrackReturnTypeTags.FunctionTypeDepth.push();
4815  TrackReturnTypeTags.FunctionTypeDepth.enterResultType();
4816  TrackReturnTypeTags.mangleType(Proto->getReturnType());
4817  TrackReturnTypeTags.FunctionTypeDepth.leaveResultType();
4818  TrackReturnTypeTags.FunctionTypeDepth.pop(saved);
4819
4820  return TrackReturnTypeTags.AbiTagsRoot.getSortedUniqueUsedAbiTags();
4821}
4822
4823CXXNameMangler::AbiTagList
4824CXXNameMangler::makeVariableTypeTags(const VarDecl *VD) {
4825  // When derived abi tags are disabled there is no need to make any list.
4826  if (DisableDerivedAbiTags)
4827    return AbiTagList();
4828
4829  llvm::raw_null_ostream NullOutStream;
4830  CXXNameMangler TrackVariableType(*this, NullOutStream);
4831  TrackVariableType.disableDerivedAbiTags();
4832
4833  TrackVariableType.mangleType(VD->getType());
4834
4835  return TrackVariableType.AbiTagsRoot.getSortedUniqueUsedAbiTags();
4836}
4837
4838bool CXXNameMangler::shouldHaveAbiTags(ItaniumMangleContextImpl &C,
4839                                       const VarDecl *VD) {
4840  llvm::raw_null_ostream NullOutStream;
4841  CXXNameMangler TrackAbiTags(C, NullOutStream, nullptr, true);
4842  TrackAbiTags.mangle(VD);
4843  return TrackAbiTags.AbiTagsRoot.getUsedAbiTags().size();
4844}
4845
4846//
4847
4848/// Mangles the name of the declaration D and emits that name to the given
4849/// output stream.
4850///
4851/// If the declaration D requires a mangled name, this routine will emit that
4852/// mangled name to \p os and return true. Otherwise, \p os will be unchanged
4853/// and this routine will return false. In this case, the caller should just
4854/// emit the identifier of the declaration (\c D->getIdentifier()) as its
4855/// name.
4856void ItaniumMangleContextImpl::mangleCXXName(const NamedDecl *D,
4857                                             raw_ostream &Out) {
4858  assert((isa<FunctionDecl>(D) || isa<VarDecl>(D)) &&
4859          "Invalid mangleName() call, argument is not a variable or function!");
4860  assert(!isa<CXXConstructorDecl>(D) && !isa<CXXDestructorDecl>(D) &&
4861         "Invalid mangleName() call on 'structor decl!");
4862
4863  PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
4864                                 getASTContext().getSourceManager(),
4865                                 "Mangling declaration");
4866
4867  CXXNameMangler Mangler(*this, Out, D);
4868  Mangler.mangle(D);
4869}
4870
4871void ItaniumMangleContextImpl::mangleCXXCtor(const CXXConstructorDecl *D,
4872                                             CXXCtorType Type,
4873                                             raw_ostream &Out) {
4874  CXXNameMangler Mangler(*this, Out, D, Type);
4875  Mangler.mangle(D);
4876}
4877
4878void ItaniumMangleContextImpl::mangleCXXDtor(const CXXDestructorDecl *D,
4879                                             CXXDtorType Type,
4880                                             raw_ostream &Out) {
4881  CXXNameMangler Mangler(*this, Out, D, Type);
4882  Mangler.mangle(D);
4883}
4884
4885void ItaniumMangleContextImpl::mangleCXXCtorComdat(const CXXConstructorDecl *D,
4886                                                   raw_ostream &Out) {
4887  CXXNameMangler Mangler(*this, Out, D, Ctor_Comdat);
4888  Mangler.mangle(D);
4889}
4890
4891void ItaniumMangleContextImpl::mangleCXXDtorComdat(const CXXDestructorDecl *D,
4892                                                   raw_ostream &Out) {
4893  CXXNameMangler Mangler(*this, Out, D, Dtor_Comdat);
4894  Mangler.mangle(D);
4895}
4896
4897void ItaniumMangleContextImpl::mangleThunk(const CXXMethodDecl *MD,
4898                                           const ThunkInfo &Thunk,
4899                                           raw_ostream &Out) {
4900  //  <special-name> ::= T <call-offset> <base encoding>
4901  //                      # base is the nominal target function of thunk
4902  //  <special-name> ::= Tc <call-offset> <call-offset> <base encoding>
4903  //                      # base is the nominal target function of thunk
4904  //                      # first call-offset is 'this' adjustment
4905  //                      # second call-offset is result adjustment
4906
4907  assert(!isa<CXXDestructorDecl>(MD) &&
4908         "Use mangleCXXDtor for destructor decls!");
4909  CXXNameMangler Mangler(*this, Out);
4910  Mangler.getStream() << "_ZT";
4911  if (!Thunk.Return.isEmpty())
4912    Mangler.getStream() << 'c';
4913
4914  // Mangle the 'this' pointer adjustment.
4915  Mangler.mangleCallOffset(Thunk.This.NonVirtual,
4916                           Thunk.This.Virtual.Itanium.VCallOffsetOffset);
4917
4918  // Mangle the return pointer adjustment if there is one.
4919  if (!Thunk.Return.isEmpty())
4920    Mangler.mangleCallOffset(Thunk.Return.NonVirtual,
4921                             Thunk.Return.Virtual.Itanium.VBaseOffsetOffset);
4922
4923  Mangler.mangleFunctionEncoding(MD);
4924}
4925
4926void ItaniumMangleContextImpl::mangleCXXDtorThunk(
4927    const CXXDestructorDecl *DD, CXXDtorType Type,
4928    const ThisAdjustment &ThisAdjustment, raw_ostream &Out) {
4929  //  <special-name> ::= T <call-offset> <base encoding>
4930  //                      # base is the nominal target function of thunk
4931  CXXNameMangler Mangler(*this, Out, DD, Type);
4932  Mangler.getStream() << "_ZT";
4933
4934  // Mangle the 'this' pointer adjustment.
4935  Mangler.mangleCallOffset(ThisAdjustment.NonVirtual,
4936                           ThisAdjustment.Virtual.Itanium.VCallOffsetOffset);
4937
4938  Mangler.mangleFunctionEncoding(DD);
4939}
4940
4941/// Returns the mangled name for a guard variable for the passed in VarDecl.
4942void ItaniumMangleContextImpl::mangleStaticGuardVariable(const VarDecl *D,
4943                                                         raw_ostream &Out) {
4944  //  <special-name> ::= GV <object name>       # Guard variable for one-time
4945  //                                            # initialization
4946  CXXNameMangler Mangler(*this, Out);
4947  // GCC 5.3.0 doesn't emit derived ABI tags for local names but that seems to
4948  // be a bug that is fixed in trunk.
4949  Mangler.getStream() << "_ZGV";
4950  Mangler.mangleName(D);
4951}
4952
4953void ItaniumMangleContextImpl::mangleDynamicInitializer(const VarDecl *MD,
4954                                                        raw_ostream &Out) {
4955  // These symbols are internal in the Itanium ABI, so the names don't matter.
4956  // Clang has traditionally used this symbol and allowed LLVM to adjust it to
4957  // avoid duplicate symbols.
4958  Out << "__cxx_global_var_init";
4959}
4960
4961void ItaniumMangleContextImpl::mangleDynamicAtExitDestructor(const VarDecl *D,
4962                                                             raw_ostream &Out) {
4963  // Prefix the mangling of D with __dtor_.
4964  CXXNameMangler Mangler(*this, Out);
4965  Mangler.getStream() << "__dtor_";
4966  if (shouldMangleDeclName(D))
4967    Mangler.mangle(D);
4968  else
4969    Mangler.getStream() << D->getName();
4970}
4971
4972void ItaniumMangleContextImpl::mangleSEHFilterExpression(
4973    const NamedDecl *EnclosingDecl, raw_ostream &Out) {
4974  CXXNameMangler Mangler(*this, Out);
4975  Mangler.getStream() << "__filt_";
4976  if (shouldMangleDeclName(EnclosingDecl))
4977    Mangler.mangle(EnclosingDecl);
4978  else
4979    Mangler.getStream() << EnclosingDecl->getName();
4980}
4981
4982void ItaniumMangleContextImpl::mangleSEHFinallyBlock(
4983    const NamedDecl *EnclosingDecl, raw_ostream &Out) {
4984  CXXNameMangler Mangler(*this, Out);
4985  Mangler.getStream() << "__fin_";
4986  if (shouldMangleDeclName(EnclosingDecl))
4987    Mangler.mangle(EnclosingDecl);
4988  else
4989    Mangler.getStream() << EnclosingDecl->getName();
4990}
4991
4992void ItaniumMangleContextImpl::mangleItaniumThreadLocalInit(const VarDecl *D,
4993                                                            raw_ostream &Out) {
4994  //  <special-name> ::= TH <object name>
4995  CXXNameMangler Mangler(*this, Out);
4996  Mangler.getStream() << "_ZTH";
4997  Mangler.mangleName(D);
4998}
4999
5000void
5001ItaniumMangleContextImpl::mangleItaniumThreadLocalWrapper(const VarDecl *D,
5002                                                          raw_ostream &Out) {
5003  //  <special-name> ::= TW <object name>
5004  CXXNameMangler Mangler(*this, Out);
5005  Mangler.getStream() << "_ZTW";
5006  Mangler.mangleName(D);
5007}
5008
5009void ItaniumMangleContextImpl::mangleReferenceTemporary(const VarDecl *D,
5010                                                        unsigned ManglingNumber,
5011                                                        raw_ostream &Out) {
5012  // We match the GCC mangling here.
5013  //  <special-name> ::= GR <object name>
5014  CXXNameMangler Mangler(*this, Out);
5015  Mangler.getStream() << "_ZGR";
5016  Mangler.mangleName(D);
5017  assert(ManglingNumber > 0 && "Reference temporary mangling number is zero!");
5018  Mangler.mangleSeqID(ManglingNumber - 1);
5019}
5020
5021void ItaniumMangleContextImpl::mangleCXXVTable(const CXXRecordDecl *RD,
5022                                               raw_ostream &Out) {
5023  // <special-name> ::= TV <type>  # virtual table
5024  CXXNameMangler Mangler(*this, Out);
5025  Mangler.getStream() << "_ZTV";
5026  Mangler.mangleNameOrStandardSubstitution(RD);
5027}
5028
5029void ItaniumMangleContextImpl::mangleCXXVTT(const CXXRecordDecl *RD,
5030                                            raw_ostream &Out) {
5031  // <special-name> ::= TT <type>  # VTT structure
5032  CXXNameMangler Mangler(*this, Out);
5033  Mangler.getStream() << "_ZTT";
5034  Mangler.mangleNameOrStandardSubstitution(RD);
5035}
5036
5037void ItaniumMangleContextImpl::mangleCXXCtorVTable(const CXXRecordDecl *RD,
5038                                                   int64_t Offset,
5039                                                   const CXXRecordDecl *Type,
5040                                                   raw_ostream &Out) {
5041  // <special-name> ::= TC <type> <offset number> _ <base type>
5042  CXXNameMangler Mangler(*this, Out);
5043  Mangler.getStream() << "_ZTC";
5044  Mangler.mangleNameOrStandardSubstitution(RD);
5045  Mangler.getStream() << Offset;
5046  Mangler.getStream() << '_';
5047  Mangler.mangleNameOrStandardSubstitution(Type);
5048}
5049
5050void ItaniumMangleContextImpl::mangleCXXRTTI(QualType Ty, raw_ostream &Out) {
5051  // <special-name> ::= TI <type>  # typeinfo structure
5052  assert(!Ty.hasQualifiers() && "RTTI info cannot have top-level qualifiers");
5053  CXXNameMangler Mangler(*this, Out);
5054  Mangler.getStream() << "_ZTI";
5055  Mangler.mangleType(Ty);
5056}
5057
5058void ItaniumMangleContextImpl::mangleCXXRTTIName(QualType Ty,
5059                                                 raw_ostream &Out) {
5060  // <special-name> ::= TS <type>  # typeinfo name (null terminated byte string)
5061  CXXNameMangler Mangler(*this, Out);
5062  Mangler.getStream() << "_ZTS";
5063  Mangler.mangleType(Ty);
5064}
5065
5066void ItaniumMangleContextImpl::mangleTypeName(QualType Ty, raw_ostream &Out) {
5067  mangleCXXRTTIName(Ty, Out);
5068}
5069
5070void ItaniumMangleContextImpl::mangleStringLiteral(const StringLiteral *, raw_ostream &) {
5071  llvm_unreachable("Can't mangle string literals");
5072}
5073
5074ItaniumMangleContext *
5075ItaniumMangleContext::create(ASTContext &Context, DiagnosticsEngine &Diags) {
5076  return new ItaniumMangleContextImpl(Context, Diags);
5077}
5078