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
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/ExprConcepts.h"
27	#include "clang/AST/ExprObjC.h"
28	#include "clang/AST/Mangle.h"
29	#include "clang/AST/TypeLoc.h"
30	#include "clang/Basic/ABI.h"
31	#include "clang/Basic/DiagnosticAST.h"
32	#include "clang/Basic/Module.h"
33	#include "clang/Basic/SourceManager.h"
34	#include "clang/Basic/TargetInfo.h"
35	#include "clang/Basic/Thunk.h"
36	#include "llvm/ADT/StringExtras.h"
37	#include "llvm/Support/ErrorHandling.h"
38	#include "llvm/Support/raw_ostream.h"
39	#include "llvm/TargetParser/RISCVTargetParser.h"
40	#include <optional>
41
42	using namespace clang;
43
44	namespace {
45
46	static bool isLocalContainerContext(const DeclContext *DC) {
47	return isa<FunctionDecl>(Val: DC) || isa<ObjCMethodDecl>(Val: DC) || isa<BlockDecl>(Val: DC);
48	}
49
50	static const FunctionDecl *getStructor(const FunctionDecl *fn) {
51	if (const FunctionTemplateDecl *ftd = fn->getPrimaryTemplate())
52	return ftd->getTemplatedDecl();
53
54	return fn;
55	}
56
57	static const NamedDecl *getStructor(const NamedDecl *decl) {
58	const FunctionDecl *fn = dyn_cast_or_null<FunctionDecl>(Val: decl);
59	return (fn ? getStructor(fn) : decl);
60	}
61
62	static bool isLambda(const NamedDecl *ND) {
63	const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Val: ND);
64	if (!Record)
65	return false;
66
67	return Record->isLambda();
68	}
69
70	static const unsigned UnknownArity = ~0U;
71
72	class ItaniumMangleContextImpl : public ItaniumMangleContext {
73	typedef std::pair<const DeclContext*, IdentifierInfo*> DiscriminatorKeyTy;
74	llvm::DenseMap<DiscriminatorKeyTy, unsigned> Discriminator;
75	llvm::DenseMap<const NamedDecl*, unsigned> Uniquifier;
76	const DiscriminatorOverrideTy DiscriminatorOverride = nullptr;
77	NamespaceDecl *StdNamespace = nullptr;
78
79	bool NeedsUniqueInternalLinkageNames = false;
80
81	public:
82	explicit ItaniumMangleContextImpl(
83	ASTContext &Context, DiagnosticsEngine &Diags,
84	DiscriminatorOverrideTy DiscriminatorOverride, bool IsAux = false)
85	: ItaniumMangleContext(Context, Diags, IsAux),
86	DiscriminatorOverride(DiscriminatorOverride) {}
87
88	/// @name Mangler Entry Points
89	/// @{
90
91	bool shouldMangleCXXName(const NamedDecl *D) override;
92	bool shouldMangleStringLiteral(const StringLiteral *) override {
93	return false;
94	}
95
96	bool isUniqueInternalLinkageDecl(const NamedDecl *ND) override;
97	void needsUniqueInternalLinkageNames() override {
98	NeedsUniqueInternalLinkageNames = true;
99	}
100
101	void mangleCXXName(GlobalDecl GD, raw_ostream &) override;
102	void mangleThunk(const CXXMethodDecl *MD, const ThunkInfo &Thunk,
103	raw_ostream &) override;
104	void mangleCXXDtorThunk(const CXXDestructorDecl *DD, CXXDtorType Type,
105	const ThisAdjustment &ThisAdjustment,
106	raw_ostream &) override;
107	void mangleReferenceTemporary(const VarDecl *D, unsigned ManglingNumber,
108	raw_ostream &) override;
109	void mangleCXXVTable(const CXXRecordDecl *RD, raw_ostream &) override;
110	void mangleCXXVTT(const CXXRecordDecl *RD, raw_ostream &) override;
111	void mangleCXXCtorVTable(const CXXRecordDecl *RD, int64_t Offset,
112	const CXXRecordDecl *Type, raw_ostream &) override;
113	void mangleCXXRTTI(QualType T, raw_ostream &) override;
114	void mangleCXXRTTIName(QualType T, raw_ostream &,
115	bool NormalizeIntegers) override;
116	void mangleCanonicalTypeName(QualType T, raw_ostream &,
117	bool NormalizeIntegers) override;
118
119	void mangleCXXCtorComdat(const CXXConstructorDecl *D, raw_ostream &) override;
120	void mangleCXXDtorComdat(const CXXDestructorDecl *D, raw_ostream &) override;
121	void mangleStaticGuardVariable(const VarDecl *D, raw_ostream &) override;
122	void mangleDynamicInitializer(const VarDecl *D, raw_ostream &Out) override;
123	void mangleDynamicAtExitDestructor(const VarDecl *D,
124	raw_ostream &Out) override;
125	void mangleDynamicStermFinalizer(const VarDecl *D, raw_ostream &Out) override;
126	void mangleSEHFilterExpression(GlobalDecl EnclosingDecl,
127	raw_ostream &Out) override;
128	void mangleSEHFinallyBlock(GlobalDecl EnclosingDecl,
129	raw_ostream &Out) override;
130	void mangleItaniumThreadLocalInit(const VarDecl *D, raw_ostream &) override;
131	void mangleItaniumThreadLocalWrapper(const VarDecl *D,
132	raw_ostream &) override;
133
134	void mangleStringLiteral(const StringLiteral *, raw_ostream &) override;
135
136	void mangleLambdaSig(const CXXRecordDecl *Lambda, raw_ostream &) override;
137
138	void mangleModuleInitializer(const Module *Module, raw_ostream &) override;
139
140	bool getNextDiscriminator(const NamedDecl *ND, unsigned &disc) {
141	// Lambda closure types are already numbered.
142	if (isLambda(ND))
143	return false;
144
145	// Anonymous tags are already numbered.
146	if (const TagDecl *Tag = dyn_cast<TagDecl>(Val: ND)) {
147	if (Tag->getName().empty() && !Tag->getTypedefNameForAnonDecl())
148	return false;
149	}
150
151	// Use the canonical number for externally visible decls.
152	if (ND->isExternallyVisible()) {
153	unsigned discriminator = getASTContext().getManglingNumber(ND, ForAuxTarget: isAux());
154	if (discriminator == 1)
155	return false;
156	disc = discriminator - 2;
157	return true;
158	}
159
160	// Make up a reasonable number for internal decls.
161	unsigned &discriminator = Uniquifier[ND];
162	if (!discriminator) {
163	const DeclContext *DC = getEffectiveDeclContext(ND);
164	discriminator = ++Discriminator[std::make_pair(x&: DC, y: ND->getIdentifier())];
165	}
166	if (discriminator == 1)
167	return false;
168	disc = discriminator-2;
169	return true;
170	}
171
172	std::string getLambdaString(const CXXRecordDecl *Lambda) override {
173	// This function matches the one in MicrosoftMangle, which returns
174	// the string that is used in lambda mangled names.
175	assert(Lambda->isLambda() && "RD must be a lambda!");
176	std::string Name("<lambda");
177	Decl *LambdaContextDecl = Lambda->getLambdaContextDecl();
178	unsigned LambdaManglingNumber = Lambda->getLambdaManglingNumber();
179	unsigned LambdaId;
180	const ParmVarDecl *Parm = dyn_cast_or_null<ParmVarDecl>(Val: LambdaContextDecl);
181	const FunctionDecl *Func =
182	Parm ? dyn_cast<FunctionDecl>(Parm->getDeclContext()) : nullptr;
183
184	if (Func) {
185	unsigned DefaultArgNo =
186	Func->getNumParams() - Parm->getFunctionScopeIndex();
187	Name += llvm::utostr(X: DefaultArgNo);
188	Name += "_";
189	}
190
191	if (LambdaManglingNumber)
192	LambdaId = LambdaManglingNumber;
193	else
194	LambdaId = getAnonymousStructIdForDebugInfo(Lambda);
195
196	Name += llvm::utostr(X: LambdaId);
197	Name += '>';
198	return Name;
199	}
200
201	DiscriminatorOverrideTy getDiscriminatorOverride() const override {
202	return DiscriminatorOverride;
203	}
204
205	NamespaceDecl *getStdNamespace();
206
207	const DeclContext *getEffectiveDeclContext(const Decl *D);
208	const DeclContext *getEffectiveParentContext(const DeclContext *DC) {
209	return getEffectiveDeclContext(D: cast<Decl>(Val: DC));
210	}
211
212	bool isInternalLinkageDecl(const NamedDecl *ND);
213
214	/// @}
215	};
216
217	/// Manage the mangling of a single name.
218	class CXXNameMangler {
219	ItaniumMangleContextImpl &Context;
220	raw_ostream &Out;
221	/// Normalize integer types for cross-language CFI support with other
222	/// languages that can't represent and encode C/C++ integer types.
223	bool NormalizeIntegers = false;
224
225	bool NullOut = false;
226	/// In the "DisableDerivedAbiTags" mode derived ABI tags are not calculated.
227	/// This mode is used when mangler creates another mangler recursively to
228	/// calculate ABI tags for the function return value or the variable type.
229	/// Also it is required to avoid infinite recursion in some cases.
230	bool DisableDerivedAbiTags = false;
231
232	/// The "structor" is the top-level declaration being mangled, if
233	/// that's not a template specialization; otherwise it's the pattern
234	/// for that specialization.
235	const NamedDecl *Structor;
236	unsigned StructorType = 0;
237
238	// An offset to add to all template parameter depths while mangling. Used
239	// when mangling a template parameter list to see if it matches a template
240	// template parameter exactly.
241	unsigned TemplateDepthOffset = 0;
242
243	/// The next substitution sequence number.
244	unsigned SeqID = 0;
245
246	class FunctionTypeDepthState {
247	unsigned Bits = 0;
248
249	enum { InResultTypeMask = 1 };
250
251	public:
252	FunctionTypeDepthState() = default;
253
254	/// The number of function types we're inside.
255	unsigned getDepth() const {
256	return Bits >> 1;
257	}
258
259	/// True if we're in the return type of the innermost function type.
260	bool isInResultType() const {
261	return Bits & InResultTypeMask;
262	}
263
264	FunctionTypeDepthState push() {
265	FunctionTypeDepthState tmp = *this;
266	Bits = (Bits & ~InResultTypeMask) + 2;
267	return tmp;
268	}
269
270	void enterResultType() {
271	Bits |= InResultTypeMask;
272	}
273
274	void leaveResultType() {
275	Bits &= ~InResultTypeMask;
276	}
277
278	void pop(FunctionTypeDepthState saved) {
279	assert(getDepth() == saved.getDepth() + 1);
280	Bits = saved.Bits;
281	}
282
283	} FunctionTypeDepth;
284
285	// abi_tag is a gcc attribute, taking one or more strings called "tags".
286	// The goal is to annotate against which version of a library an object was
287	// built and to be able to provide backwards compatibility ("dual abi").
288	// For more information see docs/ItaniumMangleAbiTags.rst.
289	typedef SmallVector<StringRef, 4> AbiTagList;
290
291	// State to gather all implicit and explicit tags used in a mangled name.
292	// Must always have an instance of this while emitting any name to keep
293	// track.
294	class AbiTagState final {
295	public:
296	explicit AbiTagState(AbiTagState *&Head) : LinkHead(Head) {
297	Parent = LinkHead;
298	LinkHead = this;
299	}
300
301	// No copy, no move.
302	AbiTagState(const AbiTagState &) = delete;
303	AbiTagState &operator=(const AbiTagState &) = delete;
304
305	~AbiTagState() { pop(); }
306
307	void write(raw_ostream &Out, const NamedDecl *ND,
308	const AbiTagList *AdditionalAbiTags) {
309	ND = cast<NamedDecl>(ND->getCanonicalDecl());
310	if (!isa<FunctionDecl>(ND) && !isa<VarDecl>(ND)) {
311	assert(
312	!AdditionalAbiTags &&
313	"only function and variables need a list of additional abi tags");
314	if (const auto *NS = dyn_cast<NamespaceDecl>(ND)) {
315	if (const auto *AbiTag = NS->getAttr<AbiTagAttr>()) {
316	UsedAbiTags.insert(UsedAbiTags.end(), AbiTag->tags().begin(),
317	AbiTag->tags().end());
318	}
319	// Don't emit abi tags for namespaces.
320	return;
321	}
322	}
323
324	AbiTagList TagList;
325	if (const auto *AbiTag = ND->getAttr<AbiTagAttr>()) {
326	UsedAbiTags.insert(UsedAbiTags.end(), AbiTag->tags().begin(),
327	AbiTag->tags().end());
328	TagList.insert(TagList.end(), AbiTag->tags().begin(),
329	AbiTag->tags().end());
330	}
331
332	if (AdditionalAbiTags) {
333	UsedAbiTags.insert(UsedAbiTags.end(), AdditionalAbiTags->begin(),
334	AdditionalAbiTags->end());
335	TagList.insert(TagList.end(), AdditionalAbiTags->begin(),
336	AdditionalAbiTags->end());
337	}
338
339	llvm::sort(TagList);
340	TagList.erase(std::unique(TagList.begin(), TagList.end()), TagList.end());
341
342	writeSortedUniqueAbiTags(Out, AbiTags: TagList);
343	}
344
345	const AbiTagList &getUsedAbiTags() const { return UsedAbiTags; }
346	void setUsedAbiTags(const AbiTagList &AbiTags) {
347	UsedAbiTags = AbiTags;
348	}
349
350	const AbiTagList &getEmittedAbiTags() const {
351	return EmittedAbiTags;
352	}
353
354	const AbiTagList &getSortedUniqueUsedAbiTags() {
355	llvm::sort(UsedAbiTags);
356	UsedAbiTags.erase(std::unique(UsedAbiTags.begin(), UsedAbiTags.end()),
357	UsedAbiTags.end());
358	return UsedAbiTags;
359	}
360
361	private:
362	//! All abi tags used implicitly or explicitly.
363	AbiTagList UsedAbiTags;
364	//! All explicit abi tags (i.e. not from namespace).
365	AbiTagList EmittedAbiTags;
366
367	AbiTagState *&LinkHead;
368	AbiTagState *Parent = nullptr;
369
370	void pop() {
371	assert(LinkHead == this &&
372	"abi tag link head must point to us on destruction");
373	if (Parent) {
374	Parent->UsedAbiTags.insert(Parent->UsedAbiTags.end(),
375	UsedAbiTags.begin(), UsedAbiTags.end());
376	Parent->EmittedAbiTags.insert(Parent->EmittedAbiTags.end(),
377	EmittedAbiTags.begin(),
378	EmittedAbiTags.end());
379	}
380	LinkHead = Parent;
381	}
382
383	void writeSortedUniqueAbiTags(raw_ostream &Out, const AbiTagList &AbiTags) {
384	for (const auto &Tag : AbiTags) {
385	EmittedAbiTags.push_back(Elt: Tag);
386	Out << "B";
387	Out << Tag.size();
388	Out << Tag;
389	}
390	}
391	};
392
393	AbiTagState *AbiTags = nullptr;
394	AbiTagState AbiTagsRoot;
395
396	llvm::DenseMap<uintptr_t, unsigned> Substitutions;
397	llvm::DenseMap<StringRef, unsigned> ModuleSubstitutions;
398
399	ASTContext &getASTContext() const { return Context.getASTContext(); }
400
401	bool isCompatibleWith(LangOptions::ClangABI Ver) {
402	return Context.getASTContext().getLangOpts().getClangABICompat() <= Ver;
403	}
404
405	bool isStd(const NamespaceDecl *NS);
406	bool isStdNamespace(const DeclContext *DC);
407
408	const RecordDecl *GetLocalClassDecl(const Decl *D);
409	bool isSpecializedAs(QualType S, llvm::StringRef Name, QualType A);
410	bool isStdCharSpecialization(const ClassTemplateSpecializationDecl *SD,
411	llvm::StringRef Name, bool HasAllocator);
412
413	public:
414	CXXNameMangler(ItaniumMangleContextImpl &C, raw_ostream &Out_,
415	const NamedDecl *D = nullptr, bool NullOut_ = false)
416	: Context(C), Out(Out_), NullOut(NullOut_), Structor(getStructor(decl: D)),
417	AbiTagsRoot(AbiTags) {
418	// These can't be mangled without a ctor type or dtor type.
419	assert(!D || (!isa<CXXDestructorDecl>(D) &&
420	!isa<CXXConstructorDecl>(D)));
421	}
422	CXXNameMangler(ItaniumMangleContextImpl &C, raw_ostream &Out_,
423	const CXXConstructorDecl *D, CXXCtorType Type)
424	: Context(C), Out(Out_), Structor(getStructor(D)), StructorType(Type),
425	AbiTagsRoot(AbiTags) {}
426	CXXNameMangler(ItaniumMangleContextImpl &C, raw_ostream &Out_,
427	const CXXDestructorDecl *D, CXXDtorType Type)
428	: Context(C), Out(Out_), Structor(getStructor(D)), StructorType(Type),
429	AbiTagsRoot(AbiTags) {}
430
431	CXXNameMangler(ItaniumMangleContextImpl &C, raw_ostream &Out_,
432	bool NormalizeIntegers_)
433	: Context(C), Out(Out_), NormalizeIntegers(NormalizeIntegers_),
434	NullOut(false), Structor(nullptr), AbiTagsRoot(AbiTags) {}
435	CXXNameMangler(CXXNameMangler &Outer, raw_ostream &Out_)
436	: Context(Outer.Context), Out(Out_), Structor(Outer.Structor),
437	StructorType(Outer.StructorType), SeqID(Outer.SeqID),
438	FunctionTypeDepth(Outer.FunctionTypeDepth), AbiTagsRoot(AbiTags),
439	Substitutions(Outer.Substitutions),
440	ModuleSubstitutions(Outer.ModuleSubstitutions) {}
441
442	CXXNameMangler(CXXNameMangler &Outer, llvm::raw_null_ostream &Out_)
443	: CXXNameMangler(Outer, (raw_ostream &)Out_) {
444	NullOut = true;
445	}
446
447	struct WithTemplateDepthOffset { unsigned Offset; };
448	CXXNameMangler(ItaniumMangleContextImpl &C, raw_ostream &Out,
449	WithTemplateDepthOffset Offset)
450	: CXXNameMangler(C, Out) {
451	TemplateDepthOffset = Offset.Offset;
452	}
453
454	raw_ostream &getStream() { return Out; }
455
456	void disableDerivedAbiTags() { DisableDerivedAbiTags = true; }
457	static bool shouldHaveAbiTags(ItaniumMangleContextImpl &C, const VarDecl *VD);
458
459	void mangle(GlobalDecl GD);
460	void mangleCallOffset(int64_t NonVirtual, int64_t Virtual);
461	void mangleNumber(const llvm::APSInt &I);
462	void mangleNumber(int64_t Number);
463	void mangleFloat(const llvm::APFloat &F);
464	void mangleFunctionEncoding(GlobalDecl GD);
465	void mangleSeqID(unsigned SeqID);
466	void mangleName(GlobalDecl GD);
467	void mangleType(QualType T);
468	void mangleNameOrStandardSubstitution(const NamedDecl *ND);
469	void mangleLambdaSig(const CXXRecordDecl *Lambda);
470	void mangleModuleNamePrefix(StringRef Name, bool IsPartition = false);
471
472	private:
473
474	bool mangleSubstitution(const NamedDecl *ND);
475	bool mangleSubstitution(NestedNameSpecifier *NNS);
476	bool mangleSubstitution(QualType T);
477	bool mangleSubstitution(TemplateName Template);
478	bool mangleSubstitution(uintptr_t Ptr);
479
480	void mangleExistingSubstitution(TemplateName name);
481
482	bool mangleStandardSubstitution(const NamedDecl *ND);
483
484	void addSubstitution(const NamedDecl *ND) {
485	ND = cast<NamedDecl>(ND->getCanonicalDecl());
486
487	addSubstitution(Ptr: reinterpret_cast<uintptr_t>(ND));
488	}
489	void addSubstitution(NestedNameSpecifier *NNS) {
490	NNS = Context.getASTContext().getCanonicalNestedNameSpecifier(NNS);
491
492	addSubstitution(Ptr: reinterpret_cast<uintptr_t>(NNS));
493	}
494	void addSubstitution(QualType T);
495	void addSubstitution(TemplateName Template);
496	void addSubstitution(uintptr_t Ptr);
497	// Destructive copy substitutions from other mangler.
498	void extendSubstitutions(CXXNameMangler* Other);
499
500	void mangleUnresolvedPrefix(NestedNameSpecifier *qualifier,
501	bool recursive = false);
502	void mangleUnresolvedName(NestedNameSpecifier *qualifier,
503	DeclarationName name,
504	const TemplateArgumentLoc *TemplateArgs,
505	unsigned NumTemplateArgs,
506	unsigned KnownArity = UnknownArity);
507
508	void mangleFunctionEncodingBareType(const FunctionDecl *FD);
509
510	void mangleNameWithAbiTags(GlobalDecl GD,
511	const AbiTagList *AdditionalAbiTags);
512	void mangleModuleName(const NamedDecl *ND);
513	void mangleTemplateName(const TemplateDecl *TD,
514	ArrayRef<TemplateArgument> Args);
515	void mangleUnqualifiedName(GlobalDecl GD, const DeclContext *DC,
516	const AbiTagList *AdditionalAbiTags) {
517	mangleUnqualifiedName(GD, cast<NamedDecl>(GD.getDecl())->getDeclName(), DC,
518	UnknownArity, AdditionalAbiTags);
519	}
520	void mangleUnqualifiedName(GlobalDecl GD, DeclarationName Name,
521	const DeclContext *DC, unsigned KnownArity,
522	const AbiTagList *AdditionalAbiTags);
523	void mangleUnscopedName(GlobalDecl GD, const DeclContext *DC,
524	const AbiTagList *AdditionalAbiTags);
525	void mangleUnscopedTemplateName(GlobalDecl GD, const DeclContext *DC,
526	const AbiTagList *AdditionalAbiTags);
527	void mangleSourceName(const IdentifierInfo *II);
528	void mangleRegCallName(const IdentifierInfo *II);
529	void mangleDeviceStubName(const IdentifierInfo *II);
530	void mangleSourceNameWithAbiTags(
531	const NamedDecl *ND, const AbiTagList *AdditionalAbiTags = nullptr);
532	void mangleLocalName(GlobalDecl GD,
533	const AbiTagList *AdditionalAbiTags);
534	void mangleBlockForPrefix(const BlockDecl *Block);
535	void mangleUnqualifiedBlock(const BlockDecl *Block);
536	void mangleTemplateParamDecl(const NamedDecl *Decl);
537	void mangleTemplateParameterList(const TemplateParameterList *Params);
538	void mangleTypeConstraint(const ConceptDecl *Concept,
539	ArrayRef<TemplateArgument> Arguments);
540	void mangleTypeConstraint(const TypeConstraint *Constraint);
541	void mangleRequiresClause(const Expr *RequiresClause);
542	void mangleLambda(const CXXRecordDecl *Lambda);
543	void mangleNestedName(GlobalDecl GD, const DeclContext *DC,
544	const AbiTagList *AdditionalAbiTags,
545	bool NoFunction=false);
546	void mangleNestedName(const TemplateDecl *TD,
547	ArrayRef<TemplateArgument> Args);
548	void mangleNestedNameWithClosurePrefix(GlobalDecl GD,
549	const NamedDecl *PrefixND,
550	const AbiTagList *AdditionalAbiTags);
551	void manglePrefix(NestedNameSpecifier *qualifier);
552	void manglePrefix(const DeclContext *DC, bool NoFunction=false);
553	void manglePrefix(QualType type);
554	void mangleTemplatePrefix(GlobalDecl GD, bool NoFunction=false);
555	void mangleTemplatePrefix(TemplateName Template);
556	const NamedDecl *getClosurePrefix(const Decl *ND);
557	void mangleClosurePrefix(const NamedDecl *ND, bool NoFunction = false);
558	bool mangleUnresolvedTypeOrSimpleId(QualType DestroyedType,
559	StringRef Prefix = "");
560	void mangleOperatorName(DeclarationName Name, unsigned Arity);
561	void mangleOperatorName(OverloadedOperatorKind OO, unsigned Arity);
562	void mangleVendorQualifier(StringRef qualifier);
563	void mangleQualifiers(Qualifiers Quals, const DependentAddressSpaceType *DAST = nullptr);
564	void mangleRefQualifier(RefQualifierKind RefQualifier);
565
566	void mangleObjCMethodName(const ObjCMethodDecl *MD);
567
568	// Declare manglers for every type class.
569	#define ABSTRACT_TYPE(CLASS, PARENT)
570	#define NON_CANONICAL_TYPE(CLASS, PARENT)
571	#define TYPE(CLASS, PARENT) void mangleType(const CLASS##Type *T);
572	#include "clang/AST/TypeNodes.inc"
573
574	void mangleType(const TagType*);
575	void mangleType(TemplateName);
576	static StringRef getCallingConvQualifierName(CallingConv CC);
577	void mangleExtParameterInfo(FunctionProtoType::ExtParameterInfo info);
578	void mangleExtFunctionInfo(const FunctionType *T);
579	void mangleBareFunctionType(const FunctionProtoType *T, bool MangleReturnType,
580	const FunctionDecl *FD = nullptr);
581	void mangleNeonVectorType(const VectorType *T);
582	void mangleNeonVectorType(const DependentVectorType *T);
583	void mangleAArch64NeonVectorType(const VectorType *T);
584	void mangleAArch64NeonVectorType(const DependentVectorType *T);
585	void mangleAArch64FixedSveVectorType(const VectorType *T);
586	void mangleAArch64FixedSveVectorType(const DependentVectorType *T);
587	void mangleRISCVFixedRVVVectorType(const VectorType *T);
588	void mangleRISCVFixedRVVVectorType(const DependentVectorType *T);
589
590	void mangleIntegerLiteral(QualType T, const llvm::APSInt &Value);
591	void mangleFloatLiteral(QualType T, const llvm::APFloat &V);
592	void mangleFixedPointLiteral();
593	void mangleNullPointer(QualType T);
594
595	void mangleMemberExprBase(const Expr *base, bool isArrow);
596	void mangleMemberExpr(const Expr *base, bool isArrow,
597	NestedNameSpecifier *qualifier,
598	NamedDecl *firstQualifierLookup,
599	DeclarationName name,
600	const TemplateArgumentLoc *TemplateArgs,
601	unsigned NumTemplateArgs,
602	unsigned knownArity);
603	void mangleCastExpression(const Expr *E, StringRef CastEncoding);
604	void mangleInitListElements(const InitListExpr *InitList);
605	void mangleRequirement(SourceLocation RequiresExprLoc,
606	const concepts::Requirement *Req);
607	void mangleExpression(const Expr *E, unsigned Arity = UnknownArity,
608	bool AsTemplateArg = false);
609	void mangleCXXCtorType(CXXCtorType T, const CXXRecordDecl *InheritedFrom);
610	void mangleCXXDtorType(CXXDtorType T);
611
612	struct TemplateArgManglingInfo;
613	void mangleTemplateArgs(TemplateName TN,
614	const TemplateArgumentLoc *TemplateArgs,
615	unsigned NumTemplateArgs);
616	void mangleTemplateArgs(TemplateName TN, ArrayRef<TemplateArgument> Args);
617	void mangleTemplateArgs(TemplateName TN, const TemplateArgumentList &AL);
618	void mangleTemplateArg(TemplateArgManglingInfo &Info, unsigned Index,
619	TemplateArgument A);
620	void mangleTemplateArg(TemplateArgument A, bool NeedExactType);
621	void mangleTemplateArgExpr(const Expr *E);
622	void mangleValueInTemplateArg(QualType T, const APValue &V, bool TopLevel,
623	bool NeedExactType = false);
624
625	void mangleTemplateParameter(unsigned Depth, unsigned Index);
626
627	void mangleFunctionParam(const ParmVarDecl *parm);
628
629	void writeAbiTags(const NamedDecl *ND,
630	const AbiTagList *AdditionalAbiTags);
631
632	// Returns sorted unique list of ABI tags.
633	AbiTagList makeFunctionReturnTypeTags(const FunctionDecl *FD);
634	// Returns sorted unique list of ABI tags.
635	AbiTagList makeVariableTypeTags(const VarDecl *VD);
636	};
637
638	}
639
640	NamespaceDecl *ItaniumMangleContextImpl::getStdNamespace() {
641	if (!StdNamespace) {
642	StdNamespace = NamespaceDecl::Create(
643	getASTContext(), getASTContext().getTranslationUnitDecl(),
644	/*Inline=*/false, SourceLocation(), SourceLocation(),
645	&getASTContext().Idents.get(Name: "std"),
646	/*PrevDecl=*/nullptr, /*Nested=*/false);
647	StdNamespace->setImplicit();
648	}
649	return StdNamespace;
650	}
651
652	/// Retrieve the declaration context that should be used when mangling the given
653	/// declaration.
654	const DeclContext *
655	ItaniumMangleContextImpl::getEffectiveDeclContext(const Decl *D) {
656	// The ABI assumes that lambda closure types that occur within
657	// default arguments live in the context of the function. However, due to
658	// the way in which Clang parses and creates function declarations, this is
659	// not the case: the lambda closure type ends up living in the context
660	// where the function itself resides, because the function declaration itself
661	// had not yet been created. Fix the context here.
662	if (const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Val: D)) {
663	if (RD->isLambda())
664	if (ParmVarDecl *ContextParam =
665	dyn_cast_or_null<ParmVarDecl>(Val: RD->getLambdaContextDecl()))
666	return ContextParam->getDeclContext();
667	}
668
669	// Perform the same check for block literals.
670	if (const BlockDecl *BD = dyn_cast<BlockDecl>(Val: D)) {
671	if (ParmVarDecl *ContextParam =
672	dyn_cast_or_null<ParmVarDecl>(Val: BD->getBlockManglingContextDecl()))
673	return ContextParam->getDeclContext();
674	}
675
676	// On ARM and AArch64, the va_list tag is always mangled as if in the std
677	// namespace. We do not represent va_list as actually being in the std
678	// namespace in C because this would result in incorrect debug info in C,
679	// among other things. It is important for both languages to have the same
680	// mangling in order for -fsanitize=cfi-icall to work.
681	if (D == getASTContext().getVaListTagDecl()) {
682	const llvm::Triple &T = getASTContext().getTargetInfo().getTriple();
683	if (T.isARM() || T.isThumb() || T.isAArch64())
684	return getStdNamespace();
685	}
686
687	const DeclContext *DC = D->getDeclContext();
688	if (isa<CapturedDecl>(Val: DC) || isa<OMPDeclareReductionDecl>(Val: DC) ||
689	isa<OMPDeclareMapperDecl>(Val: DC)) {
690	return getEffectiveDeclContext(D: cast<Decl>(Val: DC));
691	}
692
693	if (const auto *VD = dyn_cast<VarDecl>(Val: D))
694	if (VD->isExternC())
695	return getASTContext().getTranslationUnitDecl();
696
697	if (const auto *FD = dyn_cast<FunctionDecl>(Val: D)) {
698	if (FD->isExternC())
699	return getASTContext().getTranslationUnitDecl();
700	// Member-like constrained friends are mangled as if they were members of
701	// the enclosing class.
702	if (FD->isMemberLikeConstrainedFriend() &&
703	getASTContext().getLangOpts().getClangABICompat() >
704	LangOptions::ClangABI::Ver17)
705	return D->getLexicalDeclContext()->getRedeclContext();
706	}
707
708	return DC->getRedeclContext();
709	}
710
711	bool ItaniumMangleContextImpl::isInternalLinkageDecl(const NamedDecl *ND) {
712	if (ND && ND->getFormalLinkage() == Linkage::Internal &&
713	!ND->isExternallyVisible() &&
714	getEffectiveDeclContext(ND)->isFileContext() &&
715	!ND->isInAnonymousNamespace())
716	return true;
717	return false;
718	}
719
720	// Check if this Function Decl needs a unique internal linkage name.
721	bool ItaniumMangleContextImpl::isUniqueInternalLinkageDecl(
722	const NamedDecl *ND) {
723	if (!NeedsUniqueInternalLinkageNames || !ND)
724	return false;
725
726	const auto *FD = dyn_cast<FunctionDecl>(Val: ND);
727	if (!FD)
728	return false;
729
730	// For C functions without prototypes, return false as their
731	// names should not be mangled.
732	if (!FD->getType()->getAs<FunctionProtoType>())
733	return false;
734
735	if (isInternalLinkageDecl(ND))
736	return true;
737
738	return false;
739	}
740
741	bool ItaniumMangleContextImpl::shouldMangleCXXName(const NamedDecl *D) {
742	if (const auto *FD = dyn_cast<FunctionDecl>(Val: D)) {
743	LanguageLinkage L = FD->getLanguageLinkage();
744	// Overloadable functions need mangling.
745	if (FD->hasAttr<OverloadableAttr>())
746	return true;
747
748	// "main" is not mangled.
749	if (FD->isMain())
750	return false;
751
752	// The Windows ABI expects that we would never mangle "typical"
753	// user-defined entry points regardless of visibility or freestanding-ness.
754	//
755	// N.B. This is distinct from asking about "main". "main" has a lot of
756	// special rules associated with it in the standard while these
757	// user-defined entry points are outside of the purview of the standard.
758	// For example, there can be only one definition for "main" in a standards
759	// compliant program; however nothing forbids the existence of wmain and
760	// WinMain in the same translation unit.
761	if (FD->isMSVCRTEntryPoint())
762	return false;
763
764	// C++ functions and those whose names are not a simple identifier need
765	// mangling.
766	if (!FD->getDeclName().isIdentifier() || L == CXXLanguageLinkage)
767	return true;
768
769	// C functions are not mangled.
770	if (L == CLanguageLinkage)
771	return false;
772	}
773
774	// Otherwise, no mangling is done outside C++ mode.
775	if (!getASTContext().getLangOpts().CPlusPlus)
776	return false;
777
778	if (const auto *VD = dyn_cast<VarDecl>(Val: D)) {
779	// Decompositions are mangled.
780	if (isa<DecompositionDecl>(Val: VD))
781	return true;
782
783	// C variables are not mangled.
784	if (VD->isExternC())
785	return false;
786
787	// Variables at global scope are not mangled unless they have internal
788	// linkage or are specializations or are attached to a named module.
789	const DeclContext *DC = getEffectiveDeclContext(D);
790	// Check for extern variable declared locally.
791	if (DC->isFunctionOrMethod() && D->hasLinkage())
792	while (!DC->isFileContext())
793	DC = getEffectiveParentContext(DC);
794	if (DC->isTranslationUnit() && D->getFormalLinkage() != Linkage::Internal &&
795	!CXXNameMangler::shouldHaveAbiTags(C&: *this, VD) &&
796	!isa<VarTemplateSpecializationDecl>(Val: VD) &&
797	!VD->getOwningModuleForLinkage())
798	return false;
799	}
800
801	return true;
802	}
803
804	void CXXNameMangler::writeAbiTags(const NamedDecl *ND,
805	const AbiTagList *AdditionalAbiTags) {
806	assert(AbiTags && "require AbiTagState");
807	AbiTags->write(Out, ND, AdditionalAbiTags: DisableDerivedAbiTags ? nullptr : AdditionalAbiTags);
808	}
809
810	void CXXNameMangler::mangleSourceNameWithAbiTags(
811	const NamedDecl *ND, const AbiTagList *AdditionalAbiTags) {
812	mangleSourceName(II: ND->getIdentifier());
813	writeAbiTags(ND, AdditionalAbiTags);
814	}
815
816	void CXXNameMangler::mangle(GlobalDecl GD) {
817	// <mangled-name> ::= _Z <encoding>
818	// ::= <data name>
819	// ::= <special-name>
820	Out << "_Z";
821	if (isa<FunctionDecl>(Val: GD.getDecl()))
822	mangleFunctionEncoding(GD);
823	else if (isa<VarDecl, FieldDecl, MSGuidDecl, TemplateParamObjectDecl,
824	BindingDecl>(Val: GD.getDecl()))
825	mangleName(GD);
826	else if (const IndirectFieldDecl *IFD =
827	dyn_cast<IndirectFieldDecl>(Val: GD.getDecl()))
828	mangleName(IFD->getAnonField());
829	else
830	llvm_unreachable("unexpected kind of global decl");
831	}
832
833	void CXXNameMangler::mangleFunctionEncoding(GlobalDecl GD) {
834	const FunctionDecl *FD = cast<FunctionDecl>(Val: GD.getDecl());
835	// <encoding> ::= <function name> <bare-function-type>
836
837	// Don't mangle in the type if this isn't a decl we should typically mangle.
838	if (!Context.shouldMangleDeclName(FD)) {
839	mangleName(GD);
840	return;
841	}
842
843	AbiTagList ReturnTypeAbiTags = makeFunctionReturnTypeTags(FD);
844	if (ReturnTypeAbiTags.empty()) {
845	// There are no tags for return type, the simplest case. Enter the function
846	// parameter scope before mangling the name, because a template using
847	// constrained `auto` can have references to its parameters within its
848	// template argument list:
849	//
850	// template<typename T> void f(T x, C<decltype(x)> auto)
851	// ... is mangled as ...
852	// template<typename T, C<decltype(param 1)> U> void f(T, U)
853	FunctionTypeDepthState Saved = FunctionTypeDepth.push();
854	mangleName(GD);
855	FunctionTypeDepth.pop(saved: Saved);
856	mangleFunctionEncodingBareType(FD);
857	return;
858	}
859
860	// Mangle function name and encoding to temporary buffer.
861	// We have to output name and encoding to the same mangler to get the same
862	// substitution as it will be in final mangling.
863	SmallString<256> FunctionEncodingBuf;
864	llvm::raw_svector_ostream FunctionEncodingStream(FunctionEncodingBuf);
865	CXXNameMangler FunctionEncodingMangler(*this, FunctionEncodingStream);
866	// Output name of the function.
867	FunctionEncodingMangler.disableDerivedAbiTags();
868
869	FunctionTypeDepthState Saved = FunctionTypeDepth.push();
870	FunctionEncodingMangler.mangleNameWithAbiTags(GD: FD, AdditionalAbiTags: nullptr);
871	FunctionTypeDepth.pop(saved: Saved);
872
873	// Remember length of the function name in the buffer.
874	size_t EncodingPositionStart = FunctionEncodingStream.str().size();
875	FunctionEncodingMangler.mangleFunctionEncodingBareType(FD);
876
877	// Get tags from return type that are not present in function name or
878	// encoding.
879	const AbiTagList &UsedAbiTags =
880	FunctionEncodingMangler.AbiTagsRoot.getSortedUniqueUsedAbiTags();
881	AbiTagList AdditionalAbiTags(ReturnTypeAbiTags.size());
882	AdditionalAbiTags.erase(
883	CS: std::set_difference(first1: ReturnTypeAbiTags.begin(), last1: ReturnTypeAbiTags.end(),
884	first2: UsedAbiTags.begin(), last2: UsedAbiTags.end(),
885	result: AdditionalAbiTags.begin()),
886	CE: AdditionalAbiTags.end());
887
888	// Output name with implicit tags and function encoding from temporary buffer.
889	Saved = FunctionTypeDepth.push();
890	mangleNameWithAbiTags(GD: FD, AdditionalAbiTags: &AdditionalAbiTags);
891	FunctionTypeDepth.pop(saved: Saved);
892	Out << FunctionEncodingStream.str().substr(Start: EncodingPositionStart);
893
894	// Function encoding could create new substitutions so we have to add
895	// temp mangled substitutions to main mangler.
896	extendSubstitutions(Other: &FunctionEncodingMangler);
897	}
898
899	void CXXNameMangler::mangleFunctionEncodingBareType(const FunctionDecl *FD) {
900	if (FD->hasAttr<EnableIfAttr>()) {
901	FunctionTypeDepthState Saved = FunctionTypeDepth.push();
902	Out << "Ua9enable_ifI";
903	for (AttrVec::const_iterator I = FD->getAttrs().begin(),
904	E = FD->getAttrs().end();
905	I != E; ++I) {
906	EnableIfAttr *EIA = dyn_cast<EnableIfAttr>(*I);
907	if (!EIA)
908	continue;
909	if (isCompatibleWith(Ver: LangOptions::ClangABI::Ver11)) {
910	// Prior to Clang 12, we hardcoded the X/E around enable-if's argument,
911	// even though <template-arg> should not include an X/E around
912	// <expr-primary>.
913	Out << 'X';
914	mangleExpression(E: EIA->getCond());
915	Out << 'E';
916	} else {
917	mangleTemplateArgExpr(E: EIA->getCond());
918	}
919	}
920	Out << 'E';
921	FunctionTypeDepth.pop(saved: Saved);
922	}
923
924	// When mangling an inheriting constructor, the bare function type used is
925	// that of the inherited constructor.
926	if (auto *CD = dyn_cast<CXXConstructorDecl>(Val: FD))
927	if (auto Inherited = CD->getInheritedConstructor())
928	FD = Inherited.getConstructor();
929
930	// Whether the mangling of a function type includes the return type depends on
931	// the context and the nature of the function. The rules for deciding whether
932	// the return type is included are:
933	//
934	// 1. Template functions (names or types) have return types encoded, with
935	// the exceptions listed below.
936	// 2. Function types not appearing as part of a function name mangling,
937	// e.g. parameters, pointer types, etc., have return type encoded, with the
938	// exceptions listed below.
939	// 3. Non-template function names do not have return types encoded.
940	//
941	// The exceptions mentioned in (1) and (2) above, for which the return type is
942	// never included, are
943	// 1. Constructors.
944	// 2. Destructors.
945	// 3. Conversion operator functions, e.g. operator int.
946	bool MangleReturnType = false;
947	if (FunctionTemplateDecl *PrimaryTemplate = FD->getPrimaryTemplate()) {
948	if (!(isa<CXXConstructorDecl>(Val: FD) || isa<CXXDestructorDecl>(Val: FD) ||
949	isa<CXXConversionDecl>(Val: FD)))
950	MangleReturnType = true;
951
952	// Mangle the type of the primary template.
953	FD = PrimaryTemplate->getTemplatedDecl();
954	}
955
956	mangleBareFunctionType(T: FD->getType()->castAs<FunctionProtoType>(),
957	MangleReturnType, FD);
958	}
959
960	/// Return whether a given namespace is the 'std' namespace.
961	bool CXXNameMangler::isStd(const NamespaceDecl *NS) {
962	if (!Context.getEffectiveParentContext(NS)->isTranslationUnit())
963	return false;
964
965	const IdentifierInfo *II = NS->getOriginalNamespace()->getIdentifier();
966	return II && II->isStr(Str: "std");
967	}
968
969	// isStdNamespace - Return whether a given decl context is a toplevel 'std'
970	// namespace.
971	bool CXXNameMangler::isStdNamespace(const DeclContext *DC) {
972	if (!DC->isNamespace())
973	return false;
974
975	return isStd(NS: cast<NamespaceDecl>(Val: DC));
976	}
977
978	static const GlobalDecl
979	isTemplate(GlobalDecl GD, const TemplateArgumentList *&TemplateArgs) {
980	const NamedDecl *ND = cast<NamedDecl>(Val: GD.getDecl());
981	// Check if we have a function template.
982	if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Val: ND)) {
983	if (const TemplateDecl *TD = FD->getPrimaryTemplate()) {
984	TemplateArgs = FD->getTemplateSpecializationArgs();
985	return GD.getWithDecl(TD);
986	}
987	}
988
989	// Check if we have a class template.
990	if (const ClassTemplateSpecializationDecl *Spec =
991	dyn_cast<ClassTemplateSpecializationDecl>(Val: ND)) {
992	TemplateArgs = &Spec->getTemplateArgs();
993	return GD.getWithDecl(Spec->getSpecializedTemplate());
994	}
995
996	// Check if we have a variable template.
997	if (const VarTemplateSpecializationDecl *Spec =
998	dyn_cast<VarTemplateSpecializationDecl>(Val: ND)) {
999	TemplateArgs = &Spec->getTemplateArgs();
1000	return GD.getWithDecl(Spec->getSpecializedTemplate());
1001	}
1002
1003	return GlobalDecl();
1004	}
1005
1006	static TemplateName asTemplateName(GlobalDecl GD) {
1007	const TemplateDecl *TD = dyn_cast_or_null<TemplateDecl>(Val: GD.getDecl());
1008	return TemplateName(const_cast<TemplateDecl*>(TD));
1009	}
1010
1011	void CXXNameMangler::mangleName(GlobalDecl GD) {
1012	const NamedDecl *ND = cast<NamedDecl>(Val: GD.getDecl());
1013	if (const VarDecl *VD = dyn_cast<VarDecl>(Val: ND)) {
1014	// Variables should have implicit tags from its type.
1015	AbiTagList VariableTypeAbiTags = makeVariableTypeTags(VD);
1016	if (VariableTypeAbiTags.empty()) {
1017	// Simple case no variable type tags.
1018	mangleNameWithAbiTags(GD: VD, AdditionalAbiTags: nullptr);
1019	return;
1020	}
1021
1022	// Mangle variable name to null stream to collect tags.
1023	llvm::raw_null_ostream NullOutStream;
1024	CXXNameMangler VariableNameMangler(*this, NullOutStream);
1025	VariableNameMangler.disableDerivedAbiTags();
1026	VariableNameMangler.mangleNameWithAbiTags(GD: VD, AdditionalAbiTags: nullptr);
1027
1028	// Get tags from variable type that are not present in its name.
1029	const AbiTagList &UsedAbiTags =
1030	VariableNameMangler.AbiTagsRoot.getSortedUniqueUsedAbiTags();
1031	AbiTagList AdditionalAbiTags(VariableTypeAbiTags.size());
1032	AdditionalAbiTags.erase(
1033	CS: std::set_difference(first1: VariableTypeAbiTags.begin(),
1034	last1: VariableTypeAbiTags.end(), first2: UsedAbiTags.begin(),
1035	last2: UsedAbiTags.end(), result: AdditionalAbiTags.begin()),
1036	CE: AdditionalAbiTags.end());
1037
1038	// Output name with implicit tags.
1039	mangleNameWithAbiTags(GD: VD, AdditionalAbiTags: &AdditionalAbiTags);
1040	} else {
1041	mangleNameWithAbiTags(GD, AdditionalAbiTags: nullptr);
1042	}
1043	}
1044
1045	const RecordDecl *CXXNameMangler::GetLocalClassDecl(const Decl *D) {
1046	const DeclContext *DC = Context.getEffectiveDeclContext(D);
1047	while (!DC->isNamespace() && !DC->isTranslationUnit()) {
1048	if (isLocalContainerContext(DC))
1049	return dyn_cast<RecordDecl>(Val: D);
1050	D = cast<Decl>(Val: DC);
1051	DC = Context.getEffectiveDeclContext(D);
1052	}
1053	return nullptr;
1054	}
1055
1056	void CXXNameMangler::mangleNameWithAbiTags(GlobalDecl GD,
1057	const AbiTagList *AdditionalAbiTags) {
1058	const NamedDecl *ND = cast<NamedDecl>(Val: GD.getDecl());
1059	// <name> ::= [<module-name>] <nested-name>
1060	// ::= [<module-name>] <unscoped-name>
1061	// ::= [<module-name>] <unscoped-template-name> <template-args>
1062	// ::= <local-name>
1063	//
1064	const DeclContext *DC = Context.getEffectiveDeclContext(ND);
1065
1066	// If this is an extern variable declared locally, the relevant DeclContext
1067	// is that of the containing namespace, or the translation unit.
1068	// FIXME: This is a hack; extern variables declared locally should have
1069	// a proper semantic declaration context!
1070	if (isLocalContainerContext(DC) && ND->hasLinkage() && !isLambda(ND))
1071	while (!DC->isNamespace() && !DC->isTranslationUnit())
1072	DC = Context.getEffectiveParentContext(DC);
1073	else if (GetLocalClassDecl(ND)) {
1074	mangleLocalName(GD, AdditionalAbiTags);
1075	return;
1076	}
1077
1078	assert(!isa<LinkageSpecDecl>(DC) && "context cannot be LinkageSpecDecl");
1079
1080	if (isLocalContainerContext(DC)) {
1081	mangleLocalName(GD, AdditionalAbiTags);
1082	return;
1083	}
1084
1085	// Closures can require a nested-name mangling even if they're semantically
1086	// in the global namespace.
1087	if (const NamedDecl *PrefixND = getClosurePrefix(ND)) {
1088	mangleNestedNameWithClosurePrefix(GD, PrefixND, AdditionalAbiTags);
1089	return;
1090	}
1091
1092	if (DC->isTranslationUnit() || isStdNamespace(DC)) {
1093	// Check if we have a template.
1094	const TemplateArgumentList *TemplateArgs = nullptr;
1095	if (GlobalDecl TD = isTemplate(GD, TemplateArgs)) {
1096	mangleUnscopedTemplateName(GD: TD, DC, AdditionalAbiTags);
1097	mangleTemplateArgs(TN: asTemplateName(GD: TD), AL: *TemplateArgs);
1098	return;
1099	}
1100
1101	mangleUnscopedName(GD, DC, AdditionalAbiTags);
1102	return;
1103	}
1104
1105	mangleNestedName(GD, DC, AdditionalAbiTags);
1106	}
1107
1108	void CXXNameMangler::mangleModuleName(const NamedDecl *ND) {
1109	if (ND->isExternallyVisible())
1110	if (Module *M = ND->getOwningModuleForLinkage())
1111	mangleModuleNamePrefix(Name: M->getPrimaryModuleInterfaceName());
1112	}
1113
1114	// <module-name> ::= <module-subname>
1115	// ::= <module-name> <module-subname>
1116	// ::= <substitution>
1117	// <module-subname> ::= W <source-name>
1118	// ::= W P <source-name>
1119	void CXXNameMangler::mangleModuleNamePrefix(StringRef Name, bool IsPartition) {
1120	// <substitution> ::= S <seq-id> _
1121	auto It = ModuleSubstitutions.find(Val: Name);
1122	if (It != ModuleSubstitutions.end()) {
1123	Out << 'S';
1124	mangleSeqID(SeqID: It->second);
1125	return;
1126	}
1127
1128	// FIXME: Preserve hierarchy in module names rather than flattening
1129	// them to strings; use Module*s as substitution keys.
1130	auto Parts = Name.rsplit(Separator: '.');
1131	if (Parts.second.empty())
1132	Parts.second = Parts.first;
1133	else {
1134	mangleModuleNamePrefix(Name: Parts.first, IsPartition);
1135	IsPartition = false;
1136	}
1137
1138	Out << 'W';
1139	if (IsPartition)
1140	Out << 'P';
1141	Out << Parts.second.size() << Parts.second;
1142	ModuleSubstitutions.insert(KV: {Name, SeqID++});
1143	}
1144
1145	void CXXNameMangler::mangleTemplateName(const TemplateDecl *TD,
1146	ArrayRef<TemplateArgument> Args) {
1147	const DeclContext *DC = Context.getEffectiveDeclContext(TD);
1148
1149	if (DC->isTranslationUnit() || isStdNamespace(DC)) {
1150	mangleUnscopedTemplateName(TD, DC, nullptr);
1151	mangleTemplateArgs(TN: asTemplateName(TD), Args);
1152	} else {
1153	mangleNestedName(TD, Args);
1154	}
1155	}
1156
1157	void CXXNameMangler::mangleUnscopedName(GlobalDecl GD, const DeclContext *DC,
1158	const AbiTagList *AdditionalAbiTags) {
1159	// <unscoped-name> ::= <unqualified-name>
1160	// ::= St <unqualified-name> # ::std::
1161
1162	assert(!isa<LinkageSpecDecl>(DC) && "unskipped LinkageSpecDecl");
1163	if (isStdNamespace(DC))
1164	Out << "St";
1165
1166	mangleUnqualifiedName(GD, DC, AdditionalAbiTags);
1167	}
1168
1169	void CXXNameMangler::mangleUnscopedTemplateName(
1170	GlobalDecl GD, const DeclContext *DC, const AbiTagList *AdditionalAbiTags) {
1171	const TemplateDecl *ND = cast<TemplateDecl>(Val: GD.getDecl());
1172	// <unscoped-template-name> ::= <unscoped-name>
1173	// ::= <substitution>
1174	if (mangleSubstitution(ND))
1175	return;
1176
1177	// <template-template-param> ::= <template-param>
1178	if (const auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Val: ND)) {
1179	assert(!AdditionalAbiTags &&
1180	"template template param cannot have abi tags");
1181	mangleTemplateParameter(Depth: TTP->getDepth(), Index: TTP->getIndex());
1182	} else if (isa<BuiltinTemplateDecl>(Val: ND) || isa<ConceptDecl>(Val: ND)) {
1183	mangleUnscopedName(GD, DC, AdditionalAbiTags);
1184	} else {
1185	mangleUnscopedName(GD: GD.getWithDecl(ND->getTemplatedDecl()), DC,
1186	AdditionalAbiTags);
1187	}
1188
1189	addSubstitution(ND);
1190	}
1191
1192	void CXXNameMangler::mangleFloat(const llvm::APFloat &f) {
1193	// ABI:
1194	// Floating-point literals are encoded using a fixed-length
1195	// lowercase hexadecimal string corresponding to the internal
1196	// representation (IEEE on Itanium), high-order bytes first,
1197	// without leading zeroes. For example: "Lf bf800000 E" is -1.0f
1198	// on Itanium.
1199	// The 'without leading zeroes' thing seems to be an editorial
1200	// mistake; see the discussion on cxx-abi-dev beginning on
1201	// 2012-01-16.
1202
1203	// Our requirements here are just barely weird enough to justify
1204	// using a custom algorithm instead of post-processing APInt::toString().
1205
1206	llvm::APInt valueBits = f.bitcastToAPInt();
1207	unsigned numCharacters = (valueBits.getBitWidth() + 3) / 4;
1208	assert(numCharacters != 0);
1209
1210	// Allocate a buffer of the right number of characters.
1211	SmallVector<char, 20> buffer(numCharacters);
1212
1213	// Fill the buffer left-to-right.
1214	for (unsigned stringIndex = 0; stringIndex != numCharacters; ++stringIndex) {
1215	// The bit-index of the next hex digit.
1216	unsigned digitBitIndex = 4 * (numCharacters - stringIndex - 1);
1217
1218	// Project out 4 bits starting at 'digitIndex'.
1219	uint64_t hexDigit = valueBits.getRawData()[digitBitIndex / 64];
1220	hexDigit >>= (digitBitIndex % 64);
1221	hexDigit &= 0xF;
1222
1223	// Map that over to a lowercase hex digit.
1224	static const char charForHex[16] = {
1225	'0', '1', '2', '3', '4', '5', '6', '7',
1226	'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
1227	};
1228	buffer[stringIndex] = charForHex[hexDigit];
1229	}
1230
1231	Out.write(Ptr: buffer.data(), Size: numCharacters);
1232	}
1233
1234	void CXXNameMangler::mangleFloatLiteral(QualType T, const llvm::APFloat &V) {
1235	Out << 'L';
1236	mangleType(T);
1237	mangleFloat(f: V);
1238	Out << 'E';
1239	}
1240
1241	void CXXNameMangler::mangleFixedPointLiteral() {
1242	DiagnosticsEngine &Diags = Context.getDiags();
1243	unsigned DiagID = Diags.getCustomDiagID(
1244	L: DiagnosticsEngine::Error, FormatString: "cannot mangle fixed point literals yet");
1245	Diags.Report(DiagID);
1246	}
1247
1248	void CXXNameMangler::mangleNullPointer(QualType T) {
1249	// <expr-primary> ::= L <type> 0 E
1250	Out << 'L';
1251	mangleType(T);
1252	Out << "0E";
1253	}
1254
1255	void CXXNameMangler::mangleNumber(const llvm::APSInt &Value) {
1256	if (Value.isSigned() && Value.isNegative()) {
1257	Out << 'n';
1258	Value.abs().print(OS&: Out, /*signed*/ isSigned: false);
1259	} else {
1260	Value.print(OS&: Out, /*signed*/ isSigned: false);
1261	}
1262	}
1263
1264	void CXXNameMangler::mangleNumber(int64_t Number) {
1265	// <number> ::= [n] <non-negative decimal integer>
1266	if (Number < 0) {
1267	Out << 'n';
1268	Number = -Number;
1269	}
1270
1271	Out << Number;
1272	}
1273
1274	void CXXNameMangler::mangleCallOffset(int64_t NonVirtual, int64_t Virtual) {
1275	// <call-offset> ::= h <nv-offset> _
1276	// ::= v <v-offset> _
1277	// <nv-offset> ::= <offset number> # non-virtual base override
1278	// <v-offset> ::= <offset number> _ <virtual offset number>
1279	// # virtual base override, with vcall offset
1280	if (!Virtual) {
1281	Out << 'h';
1282	mangleNumber(Number: NonVirtual);
1283	Out << '_';
1284	return;
1285	}
1286
1287	Out << 'v';
1288	mangleNumber(Number: NonVirtual);
1289	Out << '_';
1290	mangleNumber(Number: Virtual);
1291	Out << '_';
1292	}
1293
1294	void CXXNameMangler::manglePrefix(QualType type) {
1295	if (const auto *TST = type->getAs<TemplateSpecializationType>()) {
1296	if (!mangleSubstitution(T: QualType(TST, 0))) {
1297	mangleTemplatePrefix(Template: TST->getTemplateName());
1298
1299	// FIXME: GCC does not appear to mangle the template arguments when
1300	// the template in question is a dependent template name. Should we
1301	// emulate that badness?
1302	mangleTemplateArgs(TN: TST->getTemplateName(), Args: TST->template_arguments());
1303	addSubstitution(T: QualType(TST, 0));
1304	}
1305	} else if (const auto *DTST =
1306	type->getAs<DependentTemplateSpecializationType>()) {
1307	if (!mangleSubstitution(T: QualType(DTST, 0))) {
1308	TemplateName Template = getASTContext().getDependentTemplateName(
1309	NNS: DTST->getQualifier(), Name: DTST->getIdentifier());
1310	mangleTemplatePrefix(Template);
1311
1312	// FIXME: GCC does not appear to mangle the template arguments when
1313	// the template in question is a dependent template name. Should we
1314	// emulate that badness?
1315	mangleTemplateArgs(TN: Template, Args: DTST->template_arguments());
1316	addSubstitution(T: QualType(DTST, 0));
1317	}
1318	} else {
1319	// We use the QualType mangle type variant here because it handles
1320	// substitutions.
1321	mangleType(T: type);
1322	}
1323	}
1324
1325	/// Mangle everything prior to the base-unresolved-name in an unresolved-name.
1326	///
1327	/// \param recursive - true if this is being called recursively,
1328	/// i.e. if there is more prefix "to the right".
1329	void CXXNameMangler::mangleUnresolvedPrefix(NestedNameSpecifier *qualifier,
1330	bool recursive) {
1331
1332	// x, ::x
1333	// <unresolved-name> ::= [gs] <base-unresolved-name>
1334
1335	// T::x / decltype(p)::x
1336	// <unresolved-name> ::= sr <unresolved-type> <base-unresolved-name>
1337
1338	// T::N::x /decltype(p)::N::x
1339	// <unresolved-name> ::= srN <unresolved-type> <unresolved-qualifier-level>+ E
1340	// <base-unresolved-name>
1341
1342	// A::x, N::y, A<T>::z; "gs" means leading "::"
1343	// <unresolved-name> ::= [gs] sr <unresolved-qualifier-level>+ E
1344	// <base-unresolved-name>
1345
1346	switch (qualifier->getKind()) {
1347	case NestedNameSpecifier::Global:
1348	Out << "gs";
1349
1350	// We want an 'sr' unless this is the entire NNS.
1351	if (recursive)
1352	Out << "sr";
1353
1354	// We never want an 'E' here.
1355	return;
1356
1357	case NestedNameSpecifier::Super:
1358	llvm_unreachable("Can't mangle __super specifier");
1359
1360	case NestedNameSpecifier::Namespace:
1361	if (qualifier->getPrefix())
1362	mangleUnresolvedPrefix(qualifier: qualifier->getPrefix(),
1363	/*recursive*/ true);
1364	else
1365	Out << "sr";
1366	mangleSourceNameWithAbiTags(qualifier->getAsNamespace());
1367	break;
1368	case NestedNameSpecifier::NamespaceAlias:
1369	if (qualifier->getPrefix())
1370	mangleUnresolvedPrefix(qualifier: qualifier->getPrefix(),
1371	/*recursive*/ true);
1372	else
1373	Out << "sr";
1374	mangleSourceNameWithAbiTags(qualifier->getAsNamespaceAlias());
1375	break;
1376
1377	case NestedNameSpecifier::TypeSpec:
1378	case NestedNameSpecifier::TypeSpecWithTemplate: {
1379	const Type *type = qualifier->getAsType();
1380
1381	// We only want to use an unresolved-type encoding if this is one of:
1382	// - a decltype
1383	// - a template type parameter
1384	// - a template template parameter with arguments
1385	// In all of these cases, we should have no prefix.
1386	if (qualifier->getPrefix()) {
1387	mangleUnresolvedPrefix(qualifier: qualifier->getPrefix(),
1388	/*recursive*/ true);
1389	} else {
1390	// Otherwise, all the cases want this.
1391	Out << "sr";
1392	}
1393
1394	if (mangleUnresolvedTypeOrSimpleId(DestroyedType: QualType(type, 0), Prefix: recursive ? "N" : ""))
1395	return;
1396
1397	break;
1398	}
1399
1400	case NestedNameSpecifier::Identifier:
1401	// Member expressions can have these without prefixes.
1402	if (qualifier->getPrefix())
1403	mangleUnresolvedPrefix(qualifier: qualifier->getPrefix(),
1404	/*recursive*/ true);
1405	else
1406	Out << "sr";
1407
1408	mangleSourceName(II: qualifier->getAsIdentifier());
1409	// An Identifier has no type information, so we can't emit abi tags for it.
1410	break;
1411	}
1412
1413	// If this was the innermost part of the NNS, and we fell out to
1414	// here, append an 'E'.
1415	if (!recursive)
1416	Out << 'E';
1417	}
1418
1419	/// Mangle an unresolved-name, which is generally used for names which
1420	/// weren't resolved to specific entities.
1421	void CXXNameMangler::mangleUnresolvedName(
1422	NestedNameSpecifier *qualifier, DeclarationName name,
1423	const TemplateArgumentLoc *TemplateArgs, unsigned NumTemplateArgs,
1424	unsigned knownArity) {
1425	if (qualifier) mangleUnresolvedPrefix(qualifier);
1426	switch (name.getNameKind()) {
1427	// <base-unresolved-name> ::= <simple-id>
1428	case DeclarationName::Identifier:
1429	mangleSourceName(II: name.getAsIdentifierInfo());
1430	break;
1431	// <base-unresolved-name> ::= dn <destructor-name>
1432	case DeclarationName::CXXDestructorName:
1433	Out << "dn";
1434	mangleUnresolvedTypeOrSimpleId(DestroyedType: name.getCXXNameType());
1435	break;
1436	// <base-unresolved-name> ::= on <operator-name>
1437	case DeclarationName::CXXConversionFunctionName:
1438	case DeclarationName::CXXLiteralOperatorName:
1439	case DeclarationName::CXXOperatorName:
1440	Out << "on";
1441	mangleOperatorName(Name: name, Arity: knownArity);
1442	break;
1443	case DeclarationName::CXXConstructorName:
1444	llvm_unreachable("Can't mangle a constructor name!");
1445	case DeclarationName::CXXUsingDirective:
1446	llvm_unreachable("Can't mangle a using directive name!");
1447	case DeclarationName::CXXDeductionGuideName:
1448	llvm_unreachable("Can't mangle a deduction guide name!");
1449	case DeclarationName::ObjCMultiArgSelector:
1450	case DeclarationName::ObjCOneArgSelector:
1451	case DeclarationName::ObjCZeroArgSelector:
1452	llvm_unreachable("Can't mangle Objective-C selector names here!");
1453	}
1454
1455	// The <simple-id> and on <operator-name> productions end in an optional
1456	// <template-args>.
1457	if (TemplateArgs)
1458	mangleTemplateArgs(TN: TemplateName(), TemplateArgs, NumTemplateArgs);
1459	}
1460
1461	void CXXNameMangler::mangleUnqualifiedName(
1462	GlobalDecl GD, DeclarationName Name, const DeclContext *DC,
1463	unsigned KnownArity, const AbiTagList *AdditionalAbiTags) {
1464	const NamedDecl *ND = cast_or_null<NamedDecl>(Val: GD.getDecl());
1465	// <unqualified-name> ::= [<module-name>] [F] <operator-name>
1466	// ::= <ctor-dtor-name>
1467	// ::= [<module-name>] [F] <source-name>
1468	// ::= [<module-name>] DC <source-name>* E
1469
1470	if (ND && DC && DC->isFileContext())
1471	mangleModuleName(ND);
1472
1473	// A member-like constrained friend is mangled with a leading 'F'.
1474	// Proposed on https://github.com/itanium-cxx-abi/cxx-abi/issues/24.
1475	auto *FD = dyn_cast<FunctionDecl>(Val: ND);
1476	auto *FTD = dyn_cast<FunctionTemplateDecl>(Val: ND);
1477	if ((FD && FD->isMemberLikeConstrainedFriend()) ||
1478	(FTD && FTD->getTemplatedDecl()->isMemberLikeConstrainedFriend())) {
1479	if (!isCompatibleWith(Ver: LangOptions::ClangABI::Ver17))
1480	Out << 'F';
1481	}
1482
1483	unsigned Arity = KnownArity;
1484	switch (Name.getNameKind()) {
1485	case DeclarationName::Identifier: {
1486	const IdentifierInfo *II = Name.getAsIdentifierInfo();
1487
1488	// We mangle decomposition declarations as the names of their bindings.
1489	if (auto *DD = dyn_cast<DecompositionDecl>(Val: ND)) {
1490	// FIXME: Non-standard mangling for decomposition declarations:
1491	//
1492	// <unqualified-name> ::= DC <source-name>* E
1493	//
1494	// Proposed on cxx-abi-dev on 2016-08-12
1495	Out << "DC";
1496	for (auto *BD : DD->bindings())
1497	mangleSourceName(II: BD->getDeclName().getAsIdentifierInfo());
1498	Out << 'E';
1499	writeAbiTags(ND, AdditionalAbiTags);
1500	break;
1501	}
1502
1503	if (auto *GD = dyn_cast<MSGuidDecl>(Val: ND)) {
1504	// We follow MSVC in mangling GUID declarations as if they were variables
1505	// with a particular reserved name. Continue the pretense here.
1506	SmallString<sizeof("_GUID_12345678_1234_1234_1234_1234567890ab")> GUID;
1507	llvm::raw_svector_ostream GUIDOS(GUID);
1508	Context.mangleMSGuidDecl(GD, GUIDOS);
1509	Out << GUID.size() << GUID;
1510	break;
1511	}
1512
1513	if (auto *TPO = dyn_cast<TemplateParamObjectDecl>(Val: ND)) {
1514	// Proposed in https://github.com/itanium-cxx-abi/cxx-abi/issues/63.
1515	Out << "TA";
1516	mangleValueInTemplateArg(T: TPO->getType().getUnqualifiedType(),
1517	V: TPO->getValue(), /*TopLevel=*/true);
1518	break;
1519	}
1520
1521	if (II) {
1522	// Match GCC's naming convention for internal linkage symbols, for
1523	// symbols that are not actually visible outside of this TU. GCC
1524	// distinguishes between internal and external linkage symbols in
1525	// its mangling, to support cases like this that were valid C++ prior
1526	// to DR426:
1527	//
1528	// void test() { extern void foo(); }
1529	// static void foo();
1530	//
1531	// Don't bother with the L marker for names in anonymous namespaces; the
1532	// 12_GLOBAL__N_1 mangling is quite sufficient there, and this better
1533	// matches GCC anyway, because GCC does not treat anonymous namespaces as
1534	// implying internal linkage.
1535	if (Context.isInternalLinkageDecl(ND))
1536	Out << 'L';
1537
1538	bool IsRegCall = FD &&
1539	FD->getType()->castAs<FunctionType>()->getCallConv() ==
1540	clang::CC_X86RegCall;
1541	bool IsDeviceStub =
1542	FD && FD->hasAttr<CUDAGlobalAttr>() &&
1543	GD.getKernelReferenceKind() == KernelReferenceKind::Stub;
1544	if (IsDeviceStub)
1545	mangleDeviceStubName(II);
1546	else if (IsRegCall)
1547	mangleRegCallName(II);
1548	else
1549	mangleSourceName(II);
1550
1551	writeAbiTags(ND, AdditionalAbiTags);
1552	break;
1553	}
1554
1555	// Otherwise, an anonymous entity. We must have a declaration.
1556	assert(ND && "mangling empty name without declaration");
1557
1558	if (const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(Val: ND)) {
1559	if (NS->isAnonymousNamespace()) {
1560	// This is how gcc mangles these names.
1561	Out << "12_GLOBAL__N_1";
1562	break;
1563	}
1564	}
1565
1566	if (const VarDecl *VD = dyn_cast<VarDecl>(Val: ND)) {
1567	// We must have an anonymous union or struct declaration.
1568	const RecordDecl *RD = VD->getType()->castAs<RecordType>()->getDecl();
1569
1570	// Itanium C++ ABI 5.1.2:
1571	//
1572	// For the purposes of mangling, the name of an anonymous union is
1573	// considered to be the name of the first named data member found by a
1574	// pre-order, depth-first, declaration-order walk of the data members of
1575	// the anonymous union. If there is no such data member (i.e., if all of
1576	// the data members in the union are unnamed), then there is no way for
1577	// a program to refer to the anonymous union, and there is therefore no
1578	// need to mangle its name.
1579	assert(RD->isAnonymousStructOrUnion()
1580	&& "Expected anonymous struct or union!");
1581	const FieldDecl *FD = RD->findFirstNamedDataMember();
1582
1583	// It's actually possible for various reasons for us to get here
1584	// with an empty anonymous struct / union. Fortunately, it
1585	// doesn't really matter what name we generate.
1586	if (!FD) break;
1587	assert(FD->getIdentifier() && "Data member name isn't an identifier!");
1588
1589	mangleSourceName(II: FD->getIdentifier());
1590	// Not emitting abi tags: internal name anyway.
1591	break;
1592	}
1593
1594	// Class extensions have no name as a category, and it's possible
1595	// for them to be the semantic parent of certain declarations
1596	// (primarily, tag decls defined within declarations). Such
1597	// declarations will always have internal linkage, so the name
1598	// doesn't really matter, but we shouldn't crash on them. For
1599	// safety, just handle all ObjC containers here.
1600	if (isa<ObjCContainerDecl>(Val: ND))
1601	break;
1602
1603	// We must have an anonymous struct.
1604	const TagDecl *TD = cast<TagDecl>(Val: ND);
1605	if (const TypedefNameDecl *D = TD->getTypedefNameForAnonDecl()) {
1606	assert(TD->getDeclContext() == D->getDeclContext() &&
1607	"Typedef should not be in another decl context!");
1608	assert(D->getDeclName().getAsIdentifierInfo() &&
1609	"Typedef was not named!");
1610	mangleSourceName(II: D->getDeclName().getAsIdentifierInfo());
1611	assert(!AdditionalAbiTags && "Type cannot have additional abi tags");
1612	// Explicit abi tags are still possible; take from underlying type, not
1613	// from typedef.
1614	writeAbiTags(TD, nullptr);
1615	break;
1616	}
1617
1618	// <unnamed-type-name> ::= <closure-type-name>
1619	//
1620	// <closure-type-name> ::= Ul <lambda-sig> E [ <nonnegative number> ] _
1621	// <lambda-sig> ::= <template-param-decl>* <parameter-type>+
1622	// # Parameter types or 'v' for 'void'.
1623	if (const CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Val: TD)) {
1624	std::optional<unsigned> DeviceNumber =
1625	Context.getDiscriminatorOverride()(Context.getASTContext(), Record);
1626
1627	// If we have a device-number via the discriminator, use that to mangle
1628	// the lambda, otherwise use the typical lambda-mangling-number. In either
1629	// case, a '0' should be mangled as a normal unnamed class instead of as a
1630	// lambda.
1631	if (Record->isLambda() &&
1632	((DeviceNumber && *DeviceNumber > 0) ||
1633	(!DeviceNumber && Record->getLambdaManglingNumber() > 0))) {
1634	assert(!AdditionalAbiTags &&
1635	"Lambda type cannot have additional abi tags");
1636	mangleLambda(Lambda: Record);
1637	break;
1638	}
1639	}
1640
1641	if (TD->isExternallyVisible()) {
1642	unsigned UnnamedMangle =
1643	getASTContext().getManglingNumber(TD, Context.isAux());
1644	Out << "Ut";
1645	if (UnnamedMangle > 1)
1646	Out << UnnamedMangle - 2;
1647	Out << '_';
1648	writeAbiTags(TD, AdditionalAbiTags);
1649	break;
1650	}
1651
1652	// Get a unique id for the anonymous struct. If it is not a real output
1653	// ID doesn't matter so use fake one.
1654	unsigned AnonStructId =
1655	NullOut ? 0
1656	: Context.getAnonymousStructId(TD, dyn_cast<FunctionDecl>(Val: DC));
1657
1658	// Mangle it as a source name in the form
1659	// [n] $_<id>
1660	// where n is the length of the string.
1661	SmallString<8> Str;
1662	Str += "$_";
1663	Str += llvm::utostr(X: AnonStructId);
1664
1665	Out << Str.size();
1666	Out << Str;
1667	break;
1668	}
1669
1670	case DeclarationName::ObjCZeroArgSelector:
1671	case DeclarationName::ObjCOneArgSelector:
1672	case DeclarationName::ObjCMultiArgSelector:
1673	llvm_unreachable("Can't mangle Objective-C selector names here!");
1674
1675	case DeclarationName::CXXConstructorName: {
1676	const CXXRecordDecl *InheritedFrom = nullptr;
1677	TemplateName InheritedTemplateName;
1678	const TemplateArgumentList *InheritedTemplateArgs = nullptr;
1679	if (auto Inherited =
1680	cast<CXXConstructorDecl>(Val: ND)->getInheritedConstructor()) {
1681	InheritedFrom = Inherited.getConstructor()->getParent();
1682	InheritedTemplateName =
1683	TemplateName(Inherited.getConstructor()->getPrimaryTemplate());
1684	InheritedTemplateArgs =
1685	Inherited.getConstructor()->getTemplateSpecializationArgs();
1686	}
1687
1688	if (ND == Structor)
1689	// If the named decl is the C++ constructor we're mangling, use the type
1690	// we were given.
1691	mangleCXXCtorType(T: static_cast<CXXCtorType>(StructorType), InheritedFrom);
1692	else
1693	// Otherwise, use the complete constructor name. This is relevant if a
1694	// class with a constructor is declared within a constructor.
1695	mangleCXXCtorType(T: Ctor_Complete, InheritedFrom);
1696
1697	// FIXME: The template arguments are part of the enclosing prefix or
1698	// nested-name, but it's more convenient to mangle them here.
1699	if (InheritedTemplateArgs)
1700	mangleTemplateArgs(TN: InheritedTemplateName, AL: *InheritedTemplateArgs);
1701
1702	writeAbiTags(ND, AdditionalAbiTags);
1703	break;
1704	}
1705
1706	case DeclarationName::CXXDestructorName:
1707	if (ND == Structor)
1708	// If the named decl is the C++ destructor we're mangling, use the type we
1709	// were given.
1710	mangleCXXDtorType(T: static_cast<CXXDtorType>(StructorType));
1711	else
1712	// Otherwise, use the complete destructor name. This is relevant if a
1713	// class with a destructor is declared within a destructor.
1714	mangleCXXDtorType(T: Dtor_Complete);
1715	assert(ND);
1716	writeAbiTags(ND, AdditionalAbiTags);
1717	break;
1718
1719	case DeclarationName::CXXOperatorName:
1720	if (ND && Arity == UnknownArity) {
1721	Arity = cast<FunctionDecl>(Val: ND)->getNumParams();
1722
1723	// If we have a member function, we need to include the 'this' pointer.
1724	if (const auto *MD = dyn_cast<CXXMethodDecl>(Val: ND))
1725	if (MD->isImplicitObjectMemberFunction())
1726	Arity++;
1727	}
1728	[[fallthrough]];
1729	case DeclarationName::CXXConversionFunctionName:
1730	case DeclarationName::CXXLiteralOperatorName:
1731	mangleOperatorName(Name, Arity);
1732	writeAbiTags(ND, AdditionalAbiTags);
1733	break;
1734
1735	case DeclarationName::CXXDeductionGuideName:
1736	llvm_unreachable("Can't mangle a deduction guide name!");
1737
1738	case DeclarationName::CXXUsingDirective:
1739	llvm_unreachable("Can't mangle a using directive name!");
1740	}
1741	}
1742
1743	void CXXNameMangler::mangleRegCallName(const IdentifierInfo *II) {
1744	// <source-name> ::= <positive length number> __regcall3__ <identifier>
1745	// <number> ::= [n] <non-negative decimal integer>
1746	// <identifier> ::= <unqualified source code identifier>
1747	if (getASTContext().getLangOpts().RegCall4)
1748	Out << II->getLength() + sizeof("__regcall4__") - 1 << "__regcall4__"
1749	<< II->getName();
1750	else
1751	Out << II->getLength() + sizeof("__regcall3__") - 1 << "__regcall3__"
1752	<< II->getName();
1753	}
1754
1755	void CXXNameMangler::mangleDeviceStubName(const IdentifierInfo *II) {
1756	// <source-name> ::= <positive length number> __device_stub__ <identifier>
1757	// <number> ::= [n] <non-negative decimal integer>
1758	// <identifier> ::= <unqualified source code identifier>
1759	Out << II->getLength() + sizeof("__device_stub__") - 1 << "__device_stub__"
1760	<< II->getName();
1761	}
1762
1763	void CXXNameMangler::mangleSourceName(const IdentifierInfo *II) {
1764	// <source-name> ::= <positive length number> <identifier>
1765	// <number> ::= [n] <non-negative decimal integer>
1766	// <identifier> ::= <unqualified source code identifier>
1767	Out << II->getLength() << II->getName();
1768	}
1769
1770	void CXXNameMangler::mangleNestedName(GlobalDecl GD,
1771	const DeclContext *DC,
1772	const AbiTagList *AdditionalAbiTags,
1773	bool NoFunction) {
1774	const NamedDecl *ND = cast<NamedDecl>(Val: GD.getDecl());
1775	// <nested-name>
1776	// ::= N [<CV-qualifiers>] [<ref-qualifier>] <prefix> <unqualified-name> E
1777	// ::= N [<CV-qualifiers>] [<ref-qualifier>] <template-prefix>
1778	// <template-args> E
1779
1780	Out << 'N';
1781	if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Val: ND)) {
1782	Qualifiers MethodQuals = Method->getMethodQualifiers();
1783	// We do not consider restrict a distinguishing attribute for overloading
1784	// purposes so we must not mangle it.
1785	if (Method->isExplicitObjectMemberFunction())
1786	Out << 'H';
1787	MethodQuals.removeRestrict();
1788	mangleQualifiers(Quals: MethodQuals);
1789	mangleRefQualifier(RefQualifier: Method->getRefQualifier());
1790	}
1791
1792	// Check if we have a template.
1793	const TemplateArgumentList *TemplateArgs = nullptr;
1794	if (GlobalDecl TD = isTemplate(GD, TemplateArgs)) {
1795	mangleTemplatePrefix(GD: TD, NoFunction);
1796	mangleTemplateArgs(TN: asTemplateName(GD: TD), AL: *TemplateArgs);
1797	} else {
1798	manglePrefix(DC, NoFunction);
1799	mangleUnqualifiedName(GD, DC, AdditionalAbiTags);
1800	}
1801
1802	Out << 'E';
1803	}
1804	void CXXNameMangler::mangleNestedName(const TemplateDecl *TD,
1805	ArrayRef<TemplateArgument> Args) {
1806	// <nested-name> ::= N [<CV-qualifiers>] <template-prefix> <template-args> E
1807
1808	Out << 'N';
1809
1810	mangleTemplatePrefix(TD);
1811	mangleTemplateArgs(TN: asTemplateName(TD), Args);
1812
1813	Out << 'E';
1814	}
1815
1816	void CXXNameMangler::mangleNestedNameWithClosurePrefix(
1817	GlobalDecl GD, const NamedDecl *PrefixND,
1818	const AbiTagList *AdditionalAbiTags) {
1819	// A <closure-prefix> represents a variable or field, not a regular
1820	// DeclContext, so needs special handling. In this case we're mangling a
1821	// limited form of <nested-name>:
1822	//
1823	// <nested-name> ::= N <closure-prefix> <closure-type-name> E
1824
1825	Out << 'N';
1826
1827	mangleClosurePrefix(ND: PrefixND);
1828	mangleUnqualifiedName(GD, DC: nullptr, AdditionalAbiTags);
1829
1830	Out << 'E';
1831	}
1832
1833	static GlobalDecl getParentOfLocalEntity(const DeclContext *DC) {
1834	GlobalDecl GD;
1835	// The Itanium spec says:
1836	// For entities in constructors and destructors, the mangling of the
1837	// complete object constructor or destructor is used as the base function
1838	// name, i.e. the C1 or D1 version.
1839	if (auto *CD = dyn_cast<CXXConstructorDecl>(Val: DC))
1840	GD = GlobalDecl(CD, Ctor_Complete);
1841	else if (auto *DD = dyn_cast<CXXDestructorDecl>(Val: DC))
1842	GD = GlobalDecl(DD, Dtor_Complete);
1843	else
1844	GD = GlobalDecl(cast<FunctionDecl>(Val: DC));
1845	return GD;
1846	}
1847
1848	void CXXNameMangler::mangleLocalName(GlobalDecl GD,
1849	const AbiTagList *AdditionalAbiTags) {
1850	const Decl *D = GD.getDecl();
1851	// <local-name> := Z <function encoding> E <entity name> [<discriminator>]
1852	// := Z <function encoding> E s [<discriminator>]
1853	// <local-name> := Z <function encoding> E d [ <parameter number> ]
1854	// _ <entity name>
1855	// <discriminator> := _ <non-negative number>
1856	assert(isa<NamedDecl>(D) || isa<BlockDecl>(D));
1857	const RecordDecl *RD = GetLocalClassDecl(D);
1858	const DeclContext *DC = Context.getEffectiveDeclContext(D: RD ? RD : D);
1859
1860	Out << 'Z';
1861
1862	{
1863	AbiTagState LocalAbiTags(AbiTags);
1864
1865	if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(Val: DC))
1866	mangleObjCMethodName(MD);
1867	else if (const BlockDecl *BD = dyn_cast<BlockDecl>(Val: DC))
1868	mangleBlockForPrefix(Block: BD);
1869	else
1870	mangleFunctionEncoding(GD: getParentOfLocalEntity(DC));
1871
1872	// Implicit ABI tags (from namespace) are not available in the following
1873	// entity; reset to actually emitted tags, which are available.
1874	LocalAbiTags.setUsedAbiTags(LocalAbiTags.getEmittedAbiTags());
1875	}
1876
1877	Out << 'E';
1878
1879	// GCC 5.3.0 doesn't emit derived ABI tags for local names but that seems to
1880	// be a bug that is fixed in trunk.
1881
1882	if (RD) {
1883	// The parameter number is omitted for the last parameter, 0 for the
1884	// second-to-last parameter, 1 for the third-to-last parameter, etc. The
1885	// <entity name> will of course contain a <closure-type-name>: Its
1886	// numbering will be local to the particular argument in which it appears
1887	// -- other default arguments do not affect its encoding.
1888	const CXXRecordDecl *CXXRD = dyn_cast<CXXRecordDecl>(Val: RD);
1889	if (CXXRD && CXXRD->isLambda()) {
1890	if (const ParmVarDecl *Parm
1891	= dyn_cast_or_null<ParmVarDecl>(Val: CXXRD->getLambdaContextDecl())) {
1892	if (const FunctionDecl *Func
1893	= dyn_cast<FunctionDecl>(Parm->getDeclContext())) {
1894	Out << 'd';
1895	unsigned Num = Func->getNumParams() - Parm->getFunctionScopeIndex();
1896	if (Num > 1)
1897	mangleNumber(Number: Num - 2);
1898	Out << '_';
1899	}
1900	}
1901	}
1902
1903	// Mangle the name relative to the closest enclosing function.
1904	// equality ok because RD derived from ND above
1905	if (D == RD) {
1906	mangleUnqualifiedName(RD, DC, AdditionalAbiTags);
1907	} else if (const BlockDecl *BD = dyn_cast<BlockDecl>(Val: D)) {
1908	if (const NamedDecl *PrefixND = getClosurePrefix(BD))
1909	mangleClosurePrefix(ND: PrefixND, NoFunction: true /*NoFunction*/);
1910	else
1911	manglePrefix(DC: Context.getEffectiveDeclContext(BD), NoFunction: true /*NoFunction*/);
1912	assert(!AdditionalAbiTags && "Block cannot have additional abi tags");
1913	mangleUnqualifiedBlock(Block: BD);
1914	} else {
1915	const NamedDecl *ND = cast<NamedDecl>(Val: D);
1916	mangleNestedName(GD, DC: Context.getEffectiveDeclContext(ND),
1917	AdditionalAbiTags, NoFunction: true /*NoFunction*/);
1918	}
1919	} else if (const BlockDecl *BD = dyn_cast<BlockDecl>(Val: D)) {
1920	// Mangle a block in a default parameter; see above explanation for
1921	// lambdas.
1922	if (const ParmVarDecl *Parm
1923	= dyn_cast_or_null<ParmVarDecl>(Val: BD->getBlockManglingContextDecl())) {
1924	if (const FunctionDecl *Func
1925	= dyn_cast<FunctionDecl>(Parm->getDeclContext())) {
1926	Out << 'd';
1927	unsigned Num = Func->getNumParams() - Parm->getFunctionScopeIndex();
1928	if (Num > 1)
1929	mangleNumber(Number: Num - 2);
1930	Out << '_';
1931	}
1932	}
1933
1934	assert(!AdditionalAbiTags && "Block cannot have additional abi tags");
1935	mangleUnqualifiedBlock(Block: BD);
1936	} else {
1937	mangleUnqualifiedName(GD, DC, AdditionalAbiTags);
1938	}
1939
1940	if (const NamedDecl *ND = dyn_cast<NamedDecl>(RD ? RD : D)) {
1941	unsigned disc;
1942	if (Context.getNextDiscriminator(ND, disc)) {
1943	if (disc < 10)
1944	Out << '_' << disc;
1945	else
1946	Out << "__" << disc << '_';
1947	}
1948	}
1949	}
1950
1951	void CXXNameMangler::mangleBlockForPrefix(const BlockDecl *Block) {
1952	if (GetLocalClassDecl(Block)) {
1953	mangleLocalName(GD: Block, /* AdditionalAbiTags */ nullptr);
1954	return;
1955	}
1956	const DeclContext *DC = Context.getEffectiveDeclContext(Block);
1957	if (isLocalContainerContext(DC)) {
1958	mangleLocalName(GD: Block, /* AdditionalAbiTags */ nullptr);
1959	return;
1960	}
1961	if (const NamedDecl *PrefixND = getClosurePrefix(Block))
1962	mangleClosurePrefix(ND: PrefixND);
1963	else
1964	manglePrefix(DC);
1965	mangleUnqualifiedBlock(Block);
1966	}
1967
1968	void CXXNameMangler::mangleUnqualifiedBlock(const BlockDecl *Block) {
1969	// When trying to be ABI-compatibility with clang 12 and before, mangle a
1970	// <data-member-prefix> now, with no substitutions and no <template-args>.
1971	if (Decl *Context = Block->getBlockManglingContextDecl()) {
1972	if (isCompatibleWith(Ver: LangOptions::ClangABI::Ver12) &&
1973	(isa<VarDecl>(Val: Context) || isa<FieldDecl>(Val: Context)) &&
1974	Context->getDeclContext()->isRecord()) {
1975	const auto *ND = cast<NamedDecl>(Val: Context);
1976	if (ND->getIdentifier()) {
1977	mangleSourceNameWithAbiTags(ND);
1978	Out << 'M';
1979	}
1980	}
1981	}
1982
1983	// If we have a block mangling number, use it.
1984	unsigned Number = Block->getBlockManglingNumber();
1985	// Otherwise, just make up a number. It doesn't matter what it is because
1986	// the symbol in question isn't externally visible.
1987	if (!Number)
1988	Number = Context.getBlockId(BD: Block, Local: false);
1989	else {
1990	// Stored mangling numbers are 1-based.
1991	--Number;
1992	}
1993	Out << "Ub";
1994	if (Number > 0)
1995	Out << Number - 1;
1996	Out << '_';
1997	}
1998
1999	// <template-param-decl>
2000	// ::= Ty # template type parameter
2001	// ::= Tk <concept name> [<template-args>] # constrained type parameter
2002	// ::= Tn <type> # template non-type parameter
2003	// ::= Tt <template-param-decl>* E [Q <requires-clause expr>]
2004	// # template template parameter
2005	// ::= Tp <template-param-decl> # template parameter pack
2006	void CXXNameMangler::mangleTemplateParamDecl(const NamedDecl *Decl) {
2007	// Proposed on https://github.com/itanium-cxx-abi/cxx-abi/issues/47.
2008	if (auto *Ty = dyn_cast<TemplateTypeParmDecl>(Val: Decl)) {
2009	if (Ty->isParameterPack())
2010	Out << "Tp";
2011	const TypeConstraint *Constraint = Ty->getTypeConstraint();
2012	if (Constraint && !isCompatibleWith(Ver: LangOptions::ClangABI::Ver17)) {
2013	// Proposed on https://github.com/itanium-cxx-abi/cxx-abi/issues/24.
2014	Out << "Tk";
2015	mangleTypeConstraint(Constraint);
2016	} else {
2017	Out << "Ty";
2018	}
2019	} else if (auto *Tn = dyn_cast<NonTypeTemplateParmDecl>(Val: Decl)) {
2020	if (Tn->isExpandedParameterPack()) {
2021	for (unsigned I = 0, N = Tn->getNumExpansionTypes(); I != N; ++I) {
2022	Out << "Tn";
2023	mangleType(T: Tn->getExpansionType(I));
2024	}
2025	} else {
2026	QualType T = Tn->getType();
2027	if (Tn->isParameterPack()) {
2028	Out << "Tp";
2029	if (auto *PackExpansion = T->getAs<PackExpansionType>())
2030	T = PackExpansion->getPattern();
2031	}
2032	Out << "Tn";
2033	mangleType(T);
2034	}
2035	} else if (auto *Tt = dyn_cast<TemplateTemplateParmDecl>(Val: Decl)) {
2036	if (Tt->isExpandedParameterPack()) {
2037	for (unsigned I = 0, N = Tt->getNumExpansionTemplateParameters(); I != N;
2038	++I)
2039	mangleTemplateParameterList(Params: Tt->getExpansionTemplateParameters(I));
2040	} else {
2041	if (Tt->isParameterPack())
2042	Out << "Tp";
2043	mangleTemplateParameterList(Params: Tt->getTemplateParameters());
2044	}
2045	}
2046	}
2047
2048	void CXXNameMangler::mangleTemplateParameterList(
2049	const TemplateParameterList *Params) {
2050	Out << "Tt";
2051	for (auto *Param : *Params)
2052	mangleTemplateParamDecl(Decl: Param);
2053	mangleRequiresClause(RequiresClause: Params->getRequiresClause());
2054	Out << "E";
2055	}
2056
2057	void CXXNameMangler::mangleTypeConstraint(
2058	const ConceptDecl *Concept, ArrayRef<TemplateArgument> Arguments) {
2059	const DeclContext *DC = Context.getEffectiveDeclContext(Concept);
2060	if (!Arguments.empty())
2061	mangleTemplateName(Concept, Arguments);
2062	else if (DC->isTranslationUnit() || isStdNamespace(DC))
2063	mangleUnscopedName(Concept, DC, nullptr);
2064	else
2065	mangleNestedName(Concept, DC, nullptr);
2066	}
2067
2068	void CXXNameMangler::mangleTypeConstraint(const TypeConstraint *Constraint) {
2069	llvm::SmallVector<TemplateArgument, 8> Args;
2070	if (Constraint->getTemplateArgsAsWritten()) {
2071	for (const TemplateArgumentLoc &ArgLoc :
2072	Constraint->getTemplateArgsAsWritten()->arguments())
2073	Args.push_back(Elt: ArgLoc.getArgument());
2074	}
2075	return mangleTypeConstraint(Concept: Constraint->getNamedConcept(), Arguments: Args);
2076	}
2077
2078	void CXXNameMangler::mangleRequiresClause(const Expr *RequiresClause) {
2079	// Proposed on https://github.com/itanium-cxx-abi/cxx-abi/issues/24.
2080	if (RequiresClause && !isCompatibleWith(Ver: LangOptions::ClangABI::Ver17)) {
2081	Out << 'Q';
2082	mangleExpression(E: RequiresClause);
2083	}
2084	}
2085
2086	void CXXNameMangler::mangleLambda(const CXXRecordDecl *Lambda) {
2087	// When trying to be ABI-compatibility with clang 12 and before, mangle a
2088	// <data-member-prefix> now, with no substitutions.
2089	if (Decl *Context = Lambda->getLambdaContextDecl()) {
2090	if (isCompatibleWith(Ver: LangOptions::ClangABI::Ver12) &&
2091	(isa<VarDecl>(Val: Context) || isa<FieldDecl>(Val: Context)) &&
2092	!isa<ParmVarDecl>(Val: Context)) {
2093	if (const IdentifierInfo *Name
2094	= cast<NamedDecl>(Val: Context)->getIdentifier()) {
2095	mangleSourceName(II: Name);
2096	const TemplateArgumentList *TemplateArgs = nullptr;
2097	if (GlobalDecl TD = isTemplate(GD: cast<NamedDecl>(Val: Context), TemplateArgs))
2098	mangleTemplateArgs(TN: asTemplateName(GD: TD), AL: *TemplateArgs);
2099	Out << 'M';
2100	}
2101	}
2102	}
2103
2104	Out << "Ul";
2105	mangleLambdaSig(Lambda);
2106	Out << "E";
2107
2108	// The number is omitted for the first closure type with a given
2109	// <lambda-sig> in a given context; it is n-2 for the nth closure type
2110	// (in lexical order) with that same <lambda-sig> and context.
2111	//
2112	// The AST keeps track of the number for us.
2113	//
2114	// In CUDA/HIP, to ensure the consistent lamba numbering between the device-
2115	// and host-side compilations, an extra device mangle context may be created
2116	// if the host-side CXX ABI has different numbering for lambda. In such case,
2117	// if the mangle context is that device-side one, use the device-side lambda
2118	// mangling number for this lambda.
2119	std::optional<unsigned> DeviceNumber =
2120	Context.getDiscriminatorOverride()(Context.getASTContext(), Lambda);
2121	unsigned Number =
2122	DeviceNumber ? *DeviceNumber : Lambda->getLambdaManglingNumber();
2123
2124	assert(Number > 0 && "Lambda should be mangled as an unnamed class");
2125	if (Number > 1)
2126	mangleNumber(Number: Number - 2);
2127	Out << '_';
2128	}
2129
2130	void CXXNameMangler::mangleLambdaSig(const CXXRecordDecl *Lambda) {
2131	// Proposed on https://github.com/itanium-cxx-abi/cxx-abi/issues/31.
2132	for (auto *D : Lambda->getLambdaExplicitTemplateParameters())
2133	mangleTemplateParamDecl(Decl: D);
2134
2135	// Proposed on https://github.com/itanium-cxx-abi/cxx-abi/issues/24.
2136	if (auto *TPL = Lambda->getGenericLambdaTemplateParameterList())
2137	mangleRequiresClause(RequiresClause: TPL->getRequiresClause());
2138
2139	auto *Proto =
2140	Lambda->getLambdaTypeInfo()->getType()->castAs<FunctionProtoType>();
2141	mangleBareFunctionType(Proto, /*MangleReturnType=*/false,
2142	Lambda->getLambdaStaticInvoker());
2143	}
2144
2145	void CXXNameMangler::manglePrefix(NestedNameSpecifier *qualifier) {
2146	switch (qualifier->getKind()) {
2147	case NestedNameSpecifier::Global:
2148	// nothing
2149	return;
2150
2151	case NestedNameSpecifier::Super:
2152	llvm_unreachable("Can't mangle __super specifier");
2153
2154	case NestedNameSpecifier::Namespace:
2155	mangleName(qualifier->getAsNamespace());
2156	return;
2157
2158	case NestedNameSpecifier::NamespaceAlias:
2159	mangleName(qualifier->getAsNamespaceAlias()->getNamespace());
2160	return;
2161
2162	case NestedNameSpecifier::TypeSpec:
2163	case NestedNameSpecifier::TypeSpecWithTemplate:
2164	manglePrefix(type: QualType(qualifier->getAsType(), 0));
2165	return;
2166
2167	case NestedNameSpecifier::Identifier:
2168	// Clang 14 and before did not consider this substitutable.
2169	bool Clang14Compat = isCompatibleWith(Ver: LangOptions::ClangABI::Ver14);
2170	if (!Clang14Compat && mangleSubstitution(NNS: qualifier))
2171	return;
2172
2173	// Member expressions can have these without prefixes, but that
2174	// should end up in mangleUnresolvedPrefix instead.
2175	assert(qualifier->getPrefix());
2176	manglePrefix(qualifier: qualifier->getPrefix());
2177
2178	mangleSourceName(II: qualifier->getAsIdentifier());
2179
2180	if (!Clang14Compat)
2181	addSubstitution(NNS: qualifier);
2182	return;
2183	}
2184
2185	llvm_unreachable("unexpected nested name specifier");
2186	}
2187
2188	void CXXNameMangler::manglePrefix(const DeclContext *DC, bool NoFunction) {
2189	// <prefix> ::= <prefix> <unqualified-name>
2190	// ::= <template-prefix> <template-args>
2191	// ::= <closure-prefix>
2192	// ::= <template-param>
2193	// ::= # empty
2194	// ::= <substitution>
2195
2196	assert(!isa<LinkageSpecDecl>(DC) && "prefix cannot be LinkageSpecDecl");
2197
2198	if (DC->isTranslationUnit())
2199	return;
2200
2201	if (NoFunction && isLocalContainerContext(DC))
2202	return;
2203
2204	assert(!isLocalContainerContext(DC));
2205
2206	const NamedDecl *ND = cast<NamedDecl>(Val: DC);
2207	if (mangleSubstitution(ND))
2208	return;
2209
2210	// Check if we have a template-prefix or a closure-prefix.
2211	const TemplateArgumentList *TemplateArgs = nullptr;
2212	if (GlobalDecl TD = isTemplate(GD: ND, TemplateArgs)) {
2213	mangleTemplatePrefix(GD: TD);
2214	mangleTemplateArgs(TN: asTemplateName(GD: TD), AL: *TemplateArgs);
2215	} else if (const NamedDecl *PrefixND = getClosurePrefix(ND)) {
2216	mangleClosurePrefix(ND: PrefixND, NoFunction);
2217	mangleUnqualifiedName(GD: ND, DC: nullptr, AdditionalAbiTags: nullptr);
2218	} else {
2219	const DeclContext *DC = Context.getEffectiveDeclContext(ND);
2220	manglePrefix(DC, NoFunction);
2221	mangleUnqualifiedName(GD: ND, DC, AdditionalAbiTags: nullptr);
2222	}
2223
2224	addSubstitution(ND);
2225	}
2226
2227	void CXXNameMangler::mangleTemplatePrefix(TemplateName Template) {
2228	// <template-prefix> ::= <prefix> <template unqualified-name>
2229	// ::= <template-param>
2230	// ::= <substitution>
2231	if (TemplateDecl *TD = Template.getAsTemplateDecl())
2232	return mangleTemplatePrefix(TD);
2233
2234	DependentTemplateName *Dependent = Template.getAsDependentTemplateName();
2235	assert(Dependent && "unexpected template name kind");
2236
2237	// Clang 11 and before mangled the substitution for a dependent template name
2238	// after already having emitted (a substitution for) the prefix.
2239	bool Clang11Compat = isCompatibleWith(Ver: LangOptions::ClangABI::Ver11);
2240	if (!Clang11Compat && mangleSubstitution(Template))
2241	return;
2242
2243	if (NestedNameSpecifier *Qualifier = Dependent->getQualifier())
2244	manglePrefix(qualifier: Qualifier);
2245
2246	if (Clang11Compat && mangleSubstitution(Template))
2247	return;
2248
2249	if (const IdentifierInfo *Id = Dependent->getIdentifier())
2250	mangleSourceName(II: Id);
2251	else
2252	mangleOperatorName(OO: Dependent->getOperator(), Arity: UnknownArity);
2253
2254	addSubstitution(Template);
2255	}
2256
2257	void CXXNameMangler::mangleTemplatePrefix(GlobalDecl GD,
2258	bool NoFunction) {
2259	const TemplateDecl *ND = cast<TemplateDecl>(Val: GD.getDecl());
2260	// <template-prefix> ::= <prefix> <template unqualified-name>
2261	// ::= <template-param>
2262	// ::= <substitution>
2263	// <template-template-param> ::= <template-param>
2264	// <substitution>
2265
2266	if (mangleSubstitution(ND))
2267	return;
2268
2269	// <template-template-param> ::= <template-param>
2270	if (const auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Val: ND)) {
2271	mangleTemplateParameter(Depth: TTP->getDepth(), Index: TTP->getIndex());
2272	} else {
2273	const DeclContext *DC = Context.getEffectiveDeclContext(ND);
2274	manglePrefix(DC, NoFunction);
2275	if (isa<BuiltinTemplateDecl>(Val: ND) || isa<ConceptDecl>(Val: ND))
2276	mangleUnqualifiedName(GD, DC, AdditionalAbiTags: nullptr);
2277	else
2278	mangleUnqualifiedName(GD: GD.getWithDecl(ND->getTemplatedDecl()), DC,
2279	AdditionalAbiTags: nullptr);
2280	}
2281
2282	addSubstitution(ND);
2283	}
2284
2285	const NamedDecl *CXXNameMangler::getClosurePrefix(const Decl *ND) {
2286	if (isCompatibleWith(Ver: LangOptions::ClangABI::Ver12))
2287	return nullptr;
2288
2289	const NamedDecl *Context = nullptr;
2290	if (auto *Block = dyn_cast<BlockDecl>(Val: ND)) {
2291	Context = dyn_cast_or_null<NamedDecl>(Val: Block->getBlockManglingContextDecl());
2292	} else if (auto *RD = dyn_cast<CXXRecordDecl>(Val: ND)) {
2293	if (RD->isLambda())
2294	Context = dyn_cast_or_null<NamedDecl>(Val: RD->getLambdaContextDecl());
2295	}
2296	if (!Context)
2297	return nullptr;
2298
2299	// Only lambdas within the initializer of a non-local variable or non-static
2300	// data member get a <closure-prefix>.
2301	if ((isa<VarDecl>(Val: Context) && cast<VarDecl>(Val: Context)->hasGlobalStorage()) ||
2302	isa<FieldDecl>(Val: Context))
2303	return Context;
2304
2305	return nullptr;
2306	}
2307
2308	void CXXNameMangler::mangleClosurePrefix(const NamedDecl *ND, bool NoFunction) {
2309	// <closure-prefix> ::= [ <prefix> ] <unqualified-name> M
2310	// ::= <template-prefix> <template-args> M
2311	if (mangleSubstitution(ND))
2312	return;
2313
2314	const TemplateArgumentList *TemplateArgs = nullptr;
2315	if (GlobalDecl TD = isTemplate(GD: ND, TemplateArgs)) {
2316	mangleTemplatePrefix(GD: TD, NoFunction);
2317	mangleTemplateArgs(TN: asTemplateName(GD: TD), AL: *TemplateArgs);
2318	} else {
2319	const auto *DC = Context.getEffectiveDeclContext(ND);
2320	manglePrefix(DC, NoFunction);
2321	mangleUnqualifiedName(ND, DC, nullptr);
2322	}
2323
2324	Out << 'M';
2325
2326	addSubstitution(ND);
2327	}
2328
2329	/// Mangles a template name under the production <type>. Required for
2330	/// template template arguments.
2331	/// <type> ::= <class-enum-type>
2332	/// ::= <template-param>
2333	/// ::= <substitution>
2334	void CXXNameMangler::mangleType(TemplateName TN) {
2335	if (mangleSubstitution(Template: TN))
2336	return;
2337
2338	TemplateDecl *TD = nullptr;
2339
2340	switch (TN.getKind()) {
2341	case TemplateName::QualifiedTemplate:
2342	case TemplateName::UsingTemplate:
2343	case TemplateName::Template:
2344	TD = TN.getAsTemplateDecl();
2345	goto HaveDecl;
2346
2347	HaveDecl:
2348	if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(Val: TD))
2349	mangleTemplateParameter(Depth: TTP->getDepth(), Index: TTP->getIndex());
2350	else
2351	mangleName(TD);
2352	break;
2353
2354	case TemplateName::OverloadedTemplate:
2355	case TemplateName::AssumedTemplate:
2356	llvm_unreachable("can't mangle an overloaded template name as a <type>");
2357
2358	case TemplateName::DependentTemplate: {
2359	const DependentTemplateName *Dependent = TN.getAsDependentTemplateName();
2360	assert(Dependent->isIdentifier());
2361
2362	// <class-enum-type> ::= <name>
2363	// <name> ::= <nested-name>
2364	mangleUnresolvedPrefix(qualifier: Dependent->getQualifier());
2365	mangleSourceName(II: Dependent->getIdentifier());
2366	break;
2367	}
2368
2369	case TemplateName::SubstTemplateTemplateParm: {
2370	// Substituted template parameters are mangled as the substituted
2371	// template. This will check for the substitution twice, which is
2372	// fine, but we have to return early so that we don't try to *add*
2373	// the substitution twice.
2374	SubstTemplateTemplateParmStorage *subst
2375	= TN.getAsSubstTemplateTemplateParm();
2376	mangleType(TN: subst->getReplacement());
2377	return;
2378	}
2379
2380	case TemplateName::SubstTemplateTemplateParmPack: {
2381	// FIXME: not clear how to mangle this!
2382	// template <template <class> class T...> class A {
2383	// template <template <class> class U...> void foo(B<T,U> x...);
2384	// };
2385	Out << "_SUBSTPACK_";
2386	break;
2387	}
2388	}
2389
2390	addSubstitution(Template: TN);
2391	}
2392
2393	bool CXXNameMangler::mangleUnresolvedTypeOrSimpleId(QualType Ty,
2394	StringRef Prefix) {
2395	// Only certain other types are valid as prefixes; enumerate them.
2396	switch (Ty->getTypeClass()) {
2397	case Type::Builtin:
2398	case Type::Complex:
2399	case Type::Adjusted:
2400	case Type::Decayed:
2401	case Type::Pointer:
2402	case Type::BlockPointer:
2403	case Type::LValueReference:
2404	case Type::RValueReference:
2405	case Type::MemberPointer:
2406	case Type::ConstantArray:
2407	case Type::IncompleteArray:
2408	case Type::VariableArray:
2409	case Type::DependentSizedArray:
2410	case Type::DependentAddressSpace:
2411	case Type::DependentVector:
2412	case Type::DependentSizedExtVector:
2413	case Type::Vector:
2414	case Type::ExtVector:
2415	case Type::ConstantMatrix:
2416	case Type::DependentSizedMatrix:
2417	case Type::FunctionProto:
2418	case Type::FunctionNoProto:
2419	case Type::Paren:
2420	case Type::Attributed:
2421	case Type::BTFTagAttributed:
2422	case Type::Auto:
2423	case Type::DeducedTemplateSpecialization:
2424	case Type::PackExpansion:
2425	case Type::ObjCObject:
2426	case Type::ObjCInterface:
2427	case Type::ObjCObjectPointer:
2428	case Type::ObjCTypeParam:
2429	case Type::Atomic:
2430	case Type::Pipe:
2431	case Type::MacroQualified:
2432	case Type::BitInt:
2433	case Type::DependentBitInt:
2434	llvm_unreachable("type is illegal as a nested name specifier");
2435
2436	case Type::SubstTemplateTypeParmPack:
2437	// FIXME: not clear how to mangle this!
2438	// template <class T...> class A {
2439	// template <class U...> void foo(decltype(T::foo(U())) x...);
2440	// };
2441	Out << "_SUBSTPACK_";
2442	break;
2443
2444	// <unresolved-type> ::= <template-param>
2445	// ::= <decltype>
2446	// ::= <template-template-param> <template-args>
2447	// (this last is not official yet)
2448	case Type::TypeOfExpr:
2449	case Type::TypeOf:
2450	case Type::Decltype:
2451	case Type::PackIndexing:
2452	case Type::TemplateTypeParm:
2453	case Type::UnaryTransform:
2454	case Type::SubstTemplateTypeParm:
2455	unresolvedType:
2456	// Some callers want a prefix before the mangled type.
2457	Out << Prefix;
2458
2459	// This seems to do everything we want. It's not really
2460	// sanctioned for a substituted template parameter, though.
2461	mangleType(T: Ty);
2462
2463	// We never want to print 'E' directly after an unresolved-type,
2464	// so we return directly.
2465	return true;
2466
2467	case Type::Typedef:
2468	mangleSourceNameWithAbiTags(cast<TypedefType>(Val&: Ty)->getDecl());
2469	break;
2470
2471	case Type::UnresolvedUsing:
2472	mangleSourceNameWithAbiTags(
2473	cast<UnresolvedUsingType>(Val&: Ty)->getDecl());
2474	break;
2475
2476	case Type::Enum:
2477	case Type::Record:
2478	mangleSourceNameWithAbiTags(cast<TagType>(Val&: Ty)->getDecl());
2479	break;
2480
2481	case Type::TemplateSpecialization: {
2482	const TemplateSpecializationType *TST =
2483	cast<TemplateSpecializationType>(Val&: Ty);
2484	TemplateName TN = TST->getTemplateName();
2485	switch (TN.getKind()) {
2486	case TemplateName::Template:
2487	case TemplateName::QualifiedTemplate: {
2488	TemplateDecl *TD = TN.getAsTemplateDecl();
2489
2490	// If the base is a template template parameter, this is an
2491	// unresolved type.
2492	assert(TD && "no template for template specialization type");
2493	if (isa<TemplateTemplateParmDecl>(Val: TD))
2494	goto unresolvedType;
2495
2496	mangleSourceNameWithAbiTags(TD);
2497	break;
2498	}
2499
2500	case TemplateName::OverloadedTemplate:
2501	case TemplateName::AssumedTemplate:
2502	case TemplateName::DependentTemplate:
2503	llvm_unreachable("invalid base for a template specialization type");
2504
2505	case TemplateName::SubstTemplateTemplateParm: {
2506	SubstTemplateTemplateParmStorage *subst =
2507	TN.getAsSubstTemplateTemplateParm();
2508	mangleExistingSubstitution(name: subst->getReplacement());
2509	break;
2510	}
2511
2512	case TemplateName::SubstTemplateTemplateParmPack: {
2513	// FIXME: not clear how to mangle this!
2514	// template <template <class U> class T...> class A {
2515	// template <class U...> void foo(decltype(T<U>::foo) x...);
2516	// };
2517	Out << "_SUBSTPACK_";
2518	break;
2519	}
2520	case TemplateName::UsingTemplate: {
2521	TemplateDecl *TD = TN.getAsTemplateDecl();
2522	assert(TD && !isa<TemplateTemplateParmDecl>(TD));
2523	mangleSourceNameWithAbiTags(TD);
2524	break;
2525	}
2526	}
2527
2528	// Note: we don't pass in the template name here. We are mangling the
2529	// original source-level template arguments, so we shouldn't consider
2530	// conversions to the corresponding template parameter.
2531	// FIXME: Other compilers mangle partially-resolved template arguments in
2532	// unresolved-qualifier-levels.
2533	mangleTemplateArgs(TN: TemplateName(), Args: TST->template_arguments());
2534	break;
2535	}
2536
2537	case Type::InjectedClassName:
2538	mangleSourceNameWithAbiTags(
2539	cast<InjectedClassNameType>(Val&: Ty)->getDecl());
2540	break;
2541
2542	case Type::DependentName:
2543	mangleSourceName(II: cast<DependentNameType>(Val&: Ty)->getIdentifier());
2544	break;
2545
2546	case Type::DependentTemplateSpecialization: {
2547	const DependentTemplateSpecializationType *DTST =
2548	cast<DependentTemplateSpecializationType>(Val&: Ty);
2549	TemplateName Template = getASTContext().getDependentTemplateName(
2550	NNS: DTST->getQualifier(), Name: DTST->getIdentifier());
2551	mangleSourceName(II: DTST->getIdentifier());
2552	mangleTemplateArgs(TN: Template, Args: DTST->template_arguments());
2553	break;
2554	}
2555
2556	case Type::Using:
2557	return mangleUnresolvedTypeOrSimpleId(Ty: cast<UsingType>(Val&: Ty)->desugar(),
2558	Prefix);
2559	case Type::Elaborated:
2560	return mangleUnresolvedTypeOrSimpleId(
2561	Ty: cast<ElaboratedType>(Val&: Ty)->getNamedType(), Prefix);
2562	}
2563
2564	return false;
2565	}
2566
2567	void CXXNameMangler::mangleOperatorName(DeclarationName Name, unsigned Arity) {
2568	switch (Name.getNameKind()) {
2569	case DeclarationName::CXXConstructorName:
2570	case DeclarationName::CXXDestructorName:
2571	case DeclarationName::CXXDeductionGuideName:
2572	case DeclarationName::CXXUsingDirective:
2573	case DeclarationName::Identifier:
2574	case DeclarationName::ObjCMultiArgSelector:
2575	case DeclarationName::ObjCOneArgSelector:
2576	case DeclarationName::ObjCZeroArgSelector:
2577	llvm_unreachable("Not an operator name");
2578
2579	case DeclarationName::CXXConversionFunctionName:
2580	// <operator-name> ::= cv <type> # (cast)
2581	Out << "cv";
2582	mangleType(T: Name.getCXXNameType());
2583	break;
2584
2585	case DeclarationName::CXXLiteralOperatorName:
2586	Out << "li";
2587	mangleSourceName(II: Name.getCXXLiteralIdentifier());
2588	return;
2589
2590	case DeclarationName::CXXOperatorName:
2591	mangleOperatorName(OO: Name.getCXXOverloadedOperator(), Arity);
2592	break;
2593	}
2594	}
2595
2596	void
2597	CXXNameMangler::mangleOperatorName(OverloadedOperatorKind OO, unsigned Arity) {
2598	switch (OO) {
2599	// <operator-name> ::= nw # new
2600	case OO_New: Out << "nw"; break;
2601	// ::= na # new[]
2602	case OO_Array_New: Out << "na"; break;
2603	// ::= dl # delete
2604	case OO_Delete: Out << "dl"; break;
2605	// ::= da # delete[]
2606	case OO_Array_Delete: Out << "da"; break;
2607	// ::= ps # + (unary)
2608	// ::= pl # + (binary or unknown)
2609	case OO_Plus:
2610	Out << (Arity == 1? "ps" : "pl"); break;
2611	// ::= ng # - (unary)
2612	// ::= mi # - (binary or unknown)
2613	case OO_Minus:
2614	Out << (Arity == 1? "ng" : "mi"); break;
2615	// ::= ad # & (unary)
2616	// ::= an # & (binary or unknown)
2617	case OO_Amp:
2618	Out << (Arity == 1? "ad" : "an"); break;
2619	// ::= de # * (unary)
2620	// ::= ml # * (binary or unknown)
2621	case OO_Star:
2622	// Use binary when unknown.
2623	Out << (Arity == 1? "de" : "ml"); break;
2624	// ::= co # ~
2625	case OO_Tilde: Out << "co"; break;
2626	// ::= dv # /
2627	case OO_Slash: Out << "dv"; break;
2628	// ::= rm # %
2629	case OO_Percent: Out << "rm"; break;
2630	// ::= or # |
2631	case OO_Pipe: Out << "or"; break;
2632	// ::= eo # ^
2633	case OO_Caret: Out << "eo"; break;
2634	// ::= aS # =
2635	case OO_Equal: Out << "aS"; break;
2636	// ::= pL # +=
2637	case OO_PlusEqual: Out << "pL"; break;
2638	// ::= mI # -=
2639	case OO_MinusEqual: Out << "mI"; break;
2640	// ::= mL # *=
2641	case OO_StarEqual: Out << "mL"; break;
2642	// ::= dV # /=
2643	case OO_SlashEqual: Out << "dV"; break;
2644	// ::= rM # %=
2645	case OO_PercentEqual: Out << "rM"; break;
2646	// ::= aN # &=
2647	case OO_AmpEqual: Out << "aN"; break;
2648	// ::= oR # |=
2649	case OO_PipeEqual: Out << "oR"; break;
2650	// ::= eO # ^=
2651	case OO_CaretEqual: Out << "eO"; break;
2652	// ::= ls # <<
2653	case OO_LessLess: Out << "ls"; break;
2654	// ::= rs # >>
2655	case OO_GreaterGreater: Out << "rs"; break;
2656	// ::= lS # <<=
2657	case OO_LessLessEqual: Out << "lS"; break;
2658	// ::= rS # >>=
2659	case OO_GreaterGreaterEqual: Out << "rS"; break;
2660	// ::= eq # ==
2661	case OO_EqualEqual: Out << "eq"; break;
2662	// ::= ne # !=
2663	case OO_ExclaimEqual: Out << "ne"; break;
2664	// ::= lt # <
2665	case OO_Less: Out << "lt"; break;
2666	// ::= gt # >
2667	case OO_Greater: Out << "gt"; break;
2668	// ::= le # <=
2669	case OO_LessEqual: Out << "le"; break;
2670	// ::= ge # >=
2671	case OO_GreaterEqual: Out << "ge"; break;
2672	// ::= nt # !
2673	case OO_Exclaim: Out << "nt"; break;
2674	// ::= aa # &&
2675	case OO_AmpAmp: Out << "aa"; break;
2676	// ::= oo # ||
2677	case OO_PipePipe: Out << "oo"; break;
2678	// ::= pp # ++
2679	case OO_PlusPlus: Out << "pp"; break;
2680	// ::= mm # --
2681	case OO_MinusMinus: Out << "mm"; break;
2682	// ::= cm # ,
2683	case OO_Comma: Out << "cm"; break;
2684	// ::= pm # ->*
2685	case OO_ArrowStar: Out << "pm"; break;
2686	// ::= pt # ->
2687	case OO_Arrow: Out << "pt"; break;
2688	// ::= cl # ()
2689	case OO_Call: Out << "cl"; break;
2690	// ::= ix # []
2691	case OO_Subscript: Out << "ix"; break;
2692
2693	// ::= qu # ?
2694	// The conditional operator can't be overloaded, but we still handle it when
2695	// mangling expressions.
2696	case OO_Conditional: Out << "qu"; break;
2697	// Proposal on cxx-abi-dev, 2015-10-21.
2698	// ::= aw # co_await
2699	case OO_Coawait: Out << "aw"; break;
2700	// Proposed in cxx-abi github issue 43.
2701	// ::= ss # <=>
2702	case OO_Spaceship: Out << "ss"; break;
2703
2704	case OO_None:
2705	case NUM_OVERLOADED_OPERATORS:
2706	llvm_unreachable("Not an overloaded operator");
2707	}
2708	}
2709
2710	void CXXNameMangler::mangleQualifiers(Qualifiers Quals, const DependentAddressSpaceType *DAST) {
2711	// Vendor qualifiers come first and if they are order-insensitive they must
2712	// be emitted in reversed alphabetical order, see Itanium ABI 5.1.5.
2713
2714	// <type> ::= U <addrspace-expr>
2715	if (DAST) {
2716	Out << "U2ASI";
2717	mangleExpression(E: DAST->getAddrSpaceExpr());
2718	Out << "E";
2719	}
2720
2721	// Address space qualifiers start with an ordinary letter.
2722	if (Quals.hasAddressSpace()) {
2723	// Address space extension:
2724	//
2725	// <type> ::= U <target-addrspace>
2726	// <type> ::= U <OpenCL-addrspace>
2727	// <type> ::= U <CUDA-addrspace>
2728
2729	SmallString<64> ASString;
2730	LangAS AS = Quals.getAddressSpace();
2731
2732	if (Context.getASTContext().addressSpaceMapManglingFor(AS)) {
2733	// <target-addrspace> ::= "AS" <address-space-number>
2734	unsigned TargetAS = Context.getASTContext().getTargetAddressSpace(AS);
2735	if (TargetAS != 0 ||
2736	Context.getASTContext().getTargetAddressSpace(AS: LangAS::Default) != 0)
2737	ASString = "AS" + llvm::utostr(X: TargetAS);
2738	} else {
2739	switch (AS) {
2740	default: llvm_unreachable("Not a language specific address space");
2741	// <OpenCL-addrspace> ::= "CL" [ "global" | "local" | "constant" |
2742	// "private"| "generic" | "device" |
2743	// "host" ]
2744	case LangAS::opencl_global:
2745	ASString = "CLglobal";
2746	break;
2747	case LangAS::opencl_global_device:
2748	ASString = "CLdevice";
2749	break;
2750	case LangAS::opencl_global_host:
2751	ASString = "CLhost";
2752	break;
2753	case LangAS::opencl_local:
2754	ASString = "CLlocal";
2755	break;
2756	case LangAS::opencl_constant:
2757	ASString = "CLconstant";
2758	break;
2759	case LangAS::opencl_private:
2760	ASString = "CLprivate";
2761	break;
2762	case LangAS::opencl_generic:
2763	ASString = "CLgeneric";
2764	break;
2765	// <SYCL-addrspace> ::= "SY" [ "global" | "local" | "private" |
2766	// "device" | "host" ]
2767	case LangAS::sycl_global:
2768	ASString = "SYglobal";
2769	break;
2770	case LangAS::sycl_global_device:
2771	ASString = "SYdevice";
2772	break;
2773	case LangAS::sycl_global_host:
2774	ASString = "SYhost";
2775	break;
2776	case LangAS::sycl_local:
2777	ASString = "SYlocal";
2778	break;
2779	case LangAS::sycl_private:
2780	ASString = "SYprivate";
2781	break;
2782	// <CUDA-addrspace> ::= "CU" [ "device" | "constant" | "shared" ]
2783	case LangAS::cuda_device:
2784	ASString = "CUdevice";
2785	break;
2786	case LangAS::cuda_constant:
2787	ASString = "CUconstant";
2788	break;
2789	case LangAS::cuda_shared:
2790	ASString = "CUshared";
2791	break;
2792	// <ptrsize-addrspace> ::= [ "ptr32_sptr" | "ptr32_uptr" | "ptr64" ]
2793	case LangAS::ptr32_sptr:
2794	ASString = "ptr32_sptr";
2795	break;
2796	case LangAS::ptr32_uptr:
2797	ASString = "ptr32_uptr";
2798	break;
2799	case LangAS::ptr64:
2800	ASString = "ptr64";
2801	break;
2802	}
2803	}
2804	if (!ASString.empty())
2805	mangleVendorQualifier(qualifier: ASString);
2806	}
2807
2808	// The ARC ownership qualifiers start with underscores.
2809	// Objective-C ARC Extension:
2810	//
2811	// <type> ::= U "__strong"
2812	// <type> ::= U "__weak"
2813	// <type> ::= U "__autoreleasing"
2814	//
2815	// Note: we emit __weak first to preserve the order as
2816	// required by the Itanium ABI.
2817	if (Quals.getObjCLifetime() == Qualifiers::OCL_Weak)
2818	mangleVendorQualifier(qualifier: "__weak");
2819
2820	// __unaligned (from -fms-extensions)
2821	if (Quals.hasUnaligned())
2822	mangleVendorQualifier(qualifier: "__unaligned");
2823
2824	// Remaining ARC ownership qualifiers.
2825	switch (Quals.getObjCLifetime()) {
2826	case Qualifiers::OCL_None:
2827	break;
2828
2829	case Qualifiers::OCL_Weak:
2830	// Do nothing as we already handled this case above.
2831	break;
2832
2833	case Qualifiers::OCL_Strong:
2834	mangleVendorQualifier(qualifier: "__strong");
2835	break;
2836
2837	case Qualifiers::OCL_Autoreleasing:
2838	mangleVendorQualifier(qualifier: "__autoreleasing");
2839	break;
2840
2841	case Qualifiers::OCL_ExplicitNone:
2842	// The __unsafe_unretained qualifier is *not* mangled, so that
2843	// __unsafe_unretained types in ARC produce the same manglings as the
2844	// equivalent (but, naturally, unqualified) types in non-ARC, providing
2845	// better ABI compatibility.
2846	//
2847	// It's safe to do this because unqualified 'id' won't show up
2848	// in any type signatures that need to be mangled.
2849	break;
2850	}
2851
2852	// <CV-qualifiers> ::= [r] [V] [K] # restrict (C99), volatile, const
2853	if (Quals.hasRestrict())
2854	Out << 'r';
2855	if (Quals.hasVolatile())
2856	Out << 'V';
2857	if (Quals.hasConst())
2858	Out << 'K';
2859	}
2860
2861	void CXXNameMangler::mangleVendorQualifier(StringRef name) {
2862	Out << 'U' << name.size() << name;
2863	}
2864
2865	void CXXNameMangler::mangleRefQualifier(RefQualifierKind RefQualifier) {
2866	// <ref-qualifier> ::= R # lvalue reference
2867	// ::= O # rvalue-reference
2868	switch (RefQualifier) {
2869	case RQ_None:
2870	break;
2871
2872	case RQ_LValue:
2873	Out << 'R';
2874	break;
2875
2876	case RQ_RValue:
2877	Out << 'O';
2878	break;
2879	}
2880	}
2881
2882	void CXXNameMangler::mangleObjCMethodName(const ObjCMethodDecl *MD) {
2883	Context.mangleObjCMethodNameAsSourceName(MD, Out);
2884	}
2885
2886	static bool isTypeSubstitutable(Qualifiers Quals, const Type *Ty,
2887	ASTContext &Ctx) {
2888	if (Quals)
2889	return true;
2890	if (Ty->isSpecificBuiltinType(K: BuiltinType::ObjCSel))
2891	return true;
2892	if (Ty->isOpenCLSpecificType())
2893	return true;
2894	// From Clang 18.0 we correctly treat SVE types as substitution candidates.
2895	if (Ty->isSVESizelessBuiltinType() &&
2896	Ctx.getLangOpts().getClangABICompat() > LangOptions::ClangABI::Ver17)
2897	return true;
2898	if (Ty->isBuiltinType())
2899	return false;
2900	// Through to Clang 6.0, we accidentally treated undeduced auto types as
2901	// substitution candidates.
2902	if (Ctx.getLangOpts().getClangABICompat() > LangOptions::ClangABI::Ver6 &&
2903	isa<AutoType>(Val: Ty))
2904	return false;
2905	// A placeholder type for class template deduction is substitutable with
2906	// its corresponding template name; this is handled specially when mangling
2907	// the type.
2908	if (auto *DeducedTST = Ty->getAs<DeducedTemplateSpecializationType>())
2909	if (DeducedTST->getDeducedType().isNull())
2910	return false;
2911	return true;
2912	}
2913
2914	void CXXNameMangler::mangleType(QualType T) {
2915	// If our type is instantiation-dependent but not dependent, we mangle
2916	// it as it was written in the source, removing any top-level sugar.
2917	// Otherwise, use the canonical type.
2918	//
2919	// FIXME: This is an approximation of the instantiation-dependent name
2920	// mangling rules, since we should really be using the type as written and
2921	// augmented via semantic analysis (i.e., with implicit conversions and
2922	// default template arguments) for any instantiation-dependent type.
2923	// Unfortunately, that requires several changes to our AST:
2924	// - Instantiation-dependent TemplateSpecializationTypes will need to be
2925	// uniqued, so that we can handle substitutions properly
2926	// - Default template arguments will need to be represented in the
2927	// TemplateSpecializationType, since they need to be mangled even though
2928	// they aren't written.
2929	// - Conversions on non-type template arguments need to be expressed, since
2930	// they can affect the mangling of sizeof/alignof.
2931	//
2932	// FIXME: This is wrong when mapping to the canonical type for a dependent
2933	// type discards instantiation-dependent portions of the type, such as for:
2934	//
2935	// template<typename T, int N> void f(T (&)[sizeof(N)]);
2936	// template<typename T> void f(T() throw(typename T::type)); (pre-C++17)
2937	//
2938	// It's also wrong in the opposite direction when instantiation-dependent,
2939	// canonically-equivalent types differ in some irrelevant portion of inner
2940	// type sugar. In such cases, we fail to form correct substitutions, eg:
2941	//
2942	// template<int N> void f(A<sizeof(N)> *, A<sizeof(N)> (*));
2943	//
2944	// We should instead canonicalize the non-instantiation-dependent parts,
2945	// regardless of whether the type as a whole is dependent or instantiation
2946	// dependent.
2947	if (!T->isInstantiationDependentType() || T->isDependentType())
2948	T = T.getCanonicalType();
2949	else {
2950	// Desugar any types that are purely sugar.
2951	do {
2952	// Don't desugar through template specialization types that aren't
2953	// type aliases. We need to mangle the template arguments as written.
2954	if (const TemplateSpecializationType *TST
2955	= dyn_cast<TemplateSpecializationType>(Val&: T))
2956	if (!TST->isTypeAlias())
2957	break;
2958
2959	// FIXME: We presumably shouldn't strip off ElaboratedTypes with
2960	// instantation-dependent qualifiers. See
2961	// https://github.com/itanium-cxx-abi/cxx-abi/issues/114.
2962
2963	QualType Desugared
2964	= T.getSingleStepDesugaredType(Context: Context.getASTContext());
2965	if (Desugared == T)
2966	break;
2967
2968	T = Desugared;
2969	} while (true);
2970	}
2971	SplitQualType split = T.split();
2972	Qualifiers quals = split.Quals;
2973	const Type *ty = split.Ty;
2974
2975	bool isSubstitutable =
2976	isTypeSubstitutable(Quals: quals, Ty: ty, Ctx&: Context.getASTContext());
2977	if (isSubstitutable && mangleSubstitution(T))
2978	return;
2979
2980	// If we're mangling a qualified array type, push the qualifiers to
2981	// the element type.
2982	if (quals && isa<ArrayType>(Val: T)) {
2983	ty = Context.getASTContext().getAsArrayType(T);
2984	quals = Qualifiers();
2985
2986	// Note that we don't update T: we want to add the
2987	// substitution at the original type.
2988	}
2989
2990	if (quals || ty->isDependentAddressSpaceType()) {
2991	if (const DependentAddressSpaceType *DAST =
2992	dyn_cast<DependentAddressSpaceType>(Val: ty)) {
2993	SplitQualType splitDAST = DAST->getPointeeType().split();
2994	mangleQualifiers(Quals: splitDAST.Quals, DAST);
2995	mangleType(T: QualType(splitDAST.Ty, 0));
2996	} else {
2997	mangleQualifiers(Quals: quals);
2998
2999	// Recurse: even if the qualified type isn't yet substitutable,
3000	// the unqualified type might be.
3001	mangleType(T: QualType(ty, 0));
3002	}
3003	} else {
3004	switch (ty->getTypeClass()) {
3005	#define ABSTRACT_TYPE(CLASS, PARENT)
3006	#define NON_CANONICAL_TYPE(CLASS, PARENT) \
3007	case Type::CLASS: \
3008	llvm_unreachable("can't mangle non-canonical type " #CLASS "Type"); \
3009	return;
3010	#define TYPE(CLASS, PARENT) \
3011	case Type::CLASS: \
3012	mangleType(static_cast<const CLASS##Type*>(ty)); \
3013	break;
3014	#include "clang/AST/TypeNodes.inc"
3015	}
3016	}
3017
3018	// Add the substitution.
3019	if (isSubstitutable)
3020	addSubstitution(T);
3021	}
3022
3023	void CXXNameMangler::mangleNameOrStandardSubstitution(const NamedDecl *ND) {
3024	if (!mangleStandardSubstitution(ND))
3025	mangleName(GD: ND);
3026	}
3027
3028	void CXXNameMangler::mangleType(const BuiltinType *T) {
3029	// <type> ::= <builtin-type>
3030	// <builtin-type> ::= v # void
3031	// ::= w # wchar_t
3032	// ::= b # bool
3033	// ::= c # char
3034	// ::= a # signed char
3035	// ::= h # unsigned char
3036	// ::= s # short
3037	// ::= t # unsigned short
3038	// ::= i # int
3039	// ::= j # unsigned int
3040	// ::= l # long
3041	// ::= m # unsigned long
3042	// ::= x # long long, __int64
3043	// ::= y # unsigned long long, __int64
3044	// ::= n # __int128
3045	// ::= o # unsigned __int128
3046	// ::= f # float
3047	// ::= d # double
3048	// ::= e # long double, __float80
3049	// ::= g # __float128
3050	// ::= g # __ibm128
3051	// UNSUPPORTED: ::= Dd # IEEE 754r decimal floating point (64 bits)
3052	// UNSUPPORTED: ::= De # IEEE 754r decimal floating point (128 bits)
3053	// UNSUPPORTED: ::= Df # IEEE 754r decimal floating point (32 bits)
3054	// ::= Dh # IEEE 754r half-precision floating point (16 bits)
3055	// ::= DF <number> _ # ISO/IEC TS 18661 binary floating point type _FloatN (N bits);
3056	// ::= Di # char32_t
3057	// ::= Ds # char16_t
3058	// ::= Dn # std::nullptr_t (i.e., decltype(nullptr))
3059	// ::= [DS] DA # N1169 fixed-point [_Sat] T _Accum
3060	// ::= [DS] DR # N1169 fixed-point [_Sat] T _Fract
3061	// ::= u <source-name> # vendor extended type
3062	//
3063	// <fixed-point-size>
3064	// ::= s # short
3065	// ::= t # unsigned short
3066	// ::= i # plain
3067	// ::= j # unsigned
3068	// ::= l # long
3069	// ::= m # unsigned long
3070	std::string type_name;
3071	// Normalize integer types as vendor extended types:
3072	// u<length>i<type size>
3073	// u<length>u<type size>
3074	if (NormalizeIntegers && T->isInteger()) {
3075	if (T->isSignedInteger()) {
3076	switch (getASTContext().getTypeSize(T)) {
3077	case 8:
3078	// Pick a representative for each integer size in the substitution
3079	// dictionary. (Its actual defined size is not relevant.)
3080	if (mangleSubstitution(Ptr: BuiltinType::SChar))
3081	break;
3082	Out << "u2i8";
3083	addSubstitution(Ptr: BuiltinType::SChar);
3084	break;
3085	case 16:
3086	if (mangleSubstitution(Ptr: BuiltinType::Short))
3087	break;
3088	Out << "u3i16";
3089	addSubstitution(Ptr: BuiltinType::Short);
3090	break;
3091	case 32:
3092	if (mangleSubstitution(Ptr: BuiltinType::Int))
3093	break;
3094	Out << "u3i32";
3095	addSubstitution(Ptr: BuiltinType::Int);
3096	break;
3097	case 64:
3098	if (mangleSubstitution(Ptr: BuiltinType::Long))
3099	break;
3100	Out << "u3i64";
3101	addSubstitution(Ptr: BuiltinType::Long);
3102	break;
3103	case 128:
3104	if (mangleSubstitution(Ptr: BuiltinType::Int128))
3105	break;
3106	Out << "u4i128";
3107	addSubstitution(Ptr: BuiltinType::Int128);
3108	break;
3109	default:
3110	llvm_unreachable("Unknown integer size for normalization");
3111	}
3112	} else {
3113	switch (getASTContext().getTypeSize(T)) {
3114	case 8:
3115	if (mangleSubstitution(Ptr: BuiltinType::UChar))
3116	break;
3117	Out << "u2u8";
3118	addSubstitution(Ptr: BuiltinType::UChar);
3119	break;
3120	case 16:
3121	if (mangleSubstitution(Ptr: BuiltinType::UShort))
3122	break;
3123	Out << "u3u16";
3124	addSubstitution(Ptr: BuiltinType::UShort);
3125	break;
3126	case 32:
3127	if (mangleSubstitution(Ptr: BuiltinType::UInt))
3128	break;
3129	Out << "u3u32";
3130	addSubstitution(Ptr: BuiltinType::UInt);
3131	break;
3132	case 64:
3133	if (mangleSubstitution(Ptr: BuiltinType::ULong))
3134	break;
3135	Out << "u3u64";
3136	addSubstitution(Ptr: BuiltinType::ULong);
3137	break;
3138	case 128:
3139	if (mangleSubstitution(Ptr: BuiltinType::UInt128))
3140	break;
3141	Out << "u4u128";
3142	addSubstitution(Ptr: BuiltinType::UInt128);
3143	break;
3144	default:
3145	llvm_unreachable("Unknown integer size for normalization");
3146	}
3147	}
3148	return;
3149	}
3150	switch (T->getKind()) {
3151	case BuiltinType::Void:
3152	Out << 'v';
3153	break;
3154	case BuiltinType::Bool:
3155	Out << 'b';
3156	break;
3157	case BuiltinType::Char_U:
3158	case BuiltinType::Char_S:
3159	Out << 'c';
3160	break;
3161	case BuiltinType::UChar:
3162	Out << 'h';
3163	break;
3164	case BuiltinType::UShort:
3165	Out << 't';
3166	break;
3167	case BuiltinType::UInt:
3168	Out << 'j';
3169	break;
3170	case BuiltinType::ULong:
3171	Out << 'm';
3172	break;
3173	case BuiltinType::ULongLong:
3174	Out << 'y';
3175	break;
3176	case BuiltinType::UInt128:
3177	Out << 'o';
3178	break;
3179	case BuiltinType::SChar:
3180	Out << 'a';
3181	break;
3182	case BuiltinType::WChar_S:
3183	case BuiltinType::WChar_U:
3184	Out << 'w';
3185	break;
3186	case BuiltinType::Char8:
3187	Out << "Du";
3188	break;
3189	case BuiltinType::Char16:
3190	Out << "Ds";
3191	break;
3192	case BuiltinType::Char32:
3193	Out << "Di";
3194	break;
3195	case BuiltinType::Short:
3196	Out << 's';
3197	break;
3198	case BuiltinType::Int:
3199	Out << 'i';
3200	break;
3201	case BuiltinType::Long:
3202	Out << 'l';
3203	break;
3204	case BuiltinType::LongLong:
3205	Out << 'x';
3206	break;
3207	case BuiltinType::Int128:
3208	Out << 'n';
3209	break;
3210	case BuiltinType::Float16:
3211	Out << "DF16_";
3212	break;
3213	case BuiltinType::ShortAccum:
3214	Out << "DAs";
3215	break;
3216	case BuiltinType::Accum:
3217	Out << "DAi";
3218	break;
3219	case BuiltinType::LongAccum:
3220	Out << "DAl";
3221	break;
3222	case BuiltinType::UShortAccum:
3223	Out << "DAt";
3224	break;
3225	case BuiltinType::UAccum:
3226	Out << "DAj";
3227	break;
3228	case BuiltinType::ULongAccum:
3229	Out << "DAm";
3230	break;
3231	case BuiltinType::ShortFract:
3232	Out << "DRs";
3233	break;
3234	case BuiltinType::Fract:
3235	Out << "DRi";
3236	break;
3237	case BuiltinType::LongFract:
3238	Out << "DRl";
3239	break;
3240	case BuiltinType::UShortFract:
3241	Out << "DRt";
3242	break;
3243	case BuiltinType::UFract:
3244	Out << "DRj";
3245	break;
3246	case BuiltinType::ULongFract:
3247	Out << "DRm";
3248	break;
3249	case BuiltinType::SatShortAccum:
3250	Out << "DSDAs";
3251	break;
3252	case BuiltinType::SatAccum:
3253	Out << "DSDAi";
3254	break;
3255	case BuiltinType::SatLongAccum:
3256	Out << "DSDAl";
3257	break;
3258	case BuiltinType::SatUShortAccum:
3259	Out << "DSDAt";
3260	break;
3261	case BuiltinType::SatUAccum:
3262	Out << "DSDAj";
3263	break;
3264	case BuiltinType::SatULongAccum:
3265	Out << "DSDAm";
3266	break;
3267	case BuiltinType::SatShortFract:
3268	Out << "DSDRs";
3269	break;
3270	case BuiltinType::SatFract:
3271	Out << "DSDRi";
3272	break;
3273	case BuiltinType::SatLongFract:
3274	Out << "DSDRl";
3275	break;
3276	case BuiltinType::SatUShortFract:
3277	Out << "DSDRt";
3278	break;
3279	case BuiltinType::SatUFract:
3280	Out << "DSDRj";
3281	break;
3282	case BuiltinType::SatULongFract:
3283	Out << "DSDRm";
3284	break;
3285	case BuiltinType::Half:
3286	Out << "Dh";
3287	break;
3288	case BuiltinType::Float:
3289	Out << 'f';
3290	break;
3291	case BuiltinType::Double:
3292	Out << 'd';
3293	break;
3294	case BuiltinType::LongDouble: {
3295	const TargetInfo *TI =
3296	getASTContext().getLangOpts().OpenMP &&
3297	getASTContext().getLangOpts().OpenMPIsTargetDevice
3298	? getASTContext().getAuxTargetInfo()
3299	: &getASTContext().getTargetInfo();
3300	Out << TI->getLongDoubleMangling();
3301	break;
3302	}
3303	case BuiltinType::Float128: {
3304	const TargetInfo *TI =
3305	getASTContext().getLangOpts().OpenMP &&
3306	getASTContext().getLangOpts().OpenMPIsTargetDevice
3307	? getASTContext().getAuxTargetInfo()
3308	: &getASTContext().getTargetInfo();
3309	Out << TI->getFloat128Mangling();
3310	break;
3311	}
3312	case BuiltinType::BFloat16: {
3313	const TargetInfo *TI =
3314	((getASTContext().getLangOpts().OpenMP &&
3315	getASTContext().getLangOpts().OpenMPIsTargetDevice) ||
3316	getASTContext().getLangOpts().SYCLIsDevice)
3317	? getASTContext().getAuxTargetInfo()
3318	: &getASTContext().getTargetInfo();
3319	Out << TI->getBFloat16Mangling();
3320	break;
3321	}
3322	case BuiltinType::Ibm128: {
3323	const TargetInfo *TI = &getASTContext().getTargetInfo();
3324	Out << TI->getIbm128Mangling();
3325	break;
3326	}
3327	case BuiltinType::NullPtr:
3328	Out << "Dn";
3329	break;
3330
3331	#define BUILTIN_TYPE(Id, SingletonId)
3332	#define PLACEHOLDER_TYPE(Id, SingletonId) \
3333	case BuiltinType::Id:
3334	#include "clang/AST/BuiltinTypes.def"
3335	case BuiltinType::Dependent:
3336	if (!NullOut)
3337	llvm_unreachable("mangling a placeholder type");
3338	break;
3339	case BuiltinType::ObjCId:
3340	Out << "11objc_object";
3341	break;
3342	case BuiltinType::ObjCClass:
3343	Out << "10objc_class";
3344	break;
3345	case BuiltinType::ObjCSel:
3346	Out << "13objc_selector";
3347	break;
3348	#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
3349	case BuiltinType::Id: \
3350	type_name = "ocl_" #ImgType "_" #Suffix; \
3351	Out << type_name.size() << type_name; \
3352	break;
3353	#include "clang/Basic/OpenCLImageTypes.def"
3354	case BuiltinType::OCLSampler:
3355	Out << "11ocl_sampler";
3356	break;
3357	case BuiltinType::OCLEvent:
3358	Out << "9ocl_event";
3359	break;
3360	case BuiltinType::OCLClkEvent:
3361	Out << "12ocl_clkevent";
3362	break;
3363	case BuiltinType::OCLQueue:
3364	Out << "9ocl_queue";
3365	break;
3366	case BuiltinType::OCLReserveID:
3367	Out << "13ocl_reserveid";
3368	break;
3369	#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) \
3370	case BuiltinType::Id: \
3371	type_name = "ocl_" #ExtType; \
3372	Out << type_name.size() << type_name; \
3373	break;
3374	#include "clang/Basic/OpenCLExtensionTypes.def"
3375	// The SVE types are effectively target-specific. The mangling scheme
3376	// is defined in the appendices to the Procedure Call Standard for the
3377	// Arm Architecture.
3378	#define SVE_VECTOR_TYPE(InternalName, MangledName, Id, SingletonId, NumEls, \
3379	ElBits, IsSigned, IsFP, IsBF) \
3380	case BuiltinType::Id: \
3381	if (T->getKind() == BuiltinType::SveBFloat16 && \
3382	isCompatibleWith(LangOptions::ClangABI::Ver17)) { \
3383	/* Prior to Clang 18.0 we used this incorrect mangled name */ \
3384	type_name = "__SVBFloat16_t"; \
3385	Out << "u" << type_name.size() << type_name; \
3386	} else { \
3387	type_name = MangledName; \
3388	Out << (type_name == InternalName ? "u" : "") << type_name.size() \
3389	<< type_name; \
3390	} \
3391	break;
3392	#define SVE_PREDICATE_TYPE(InternalName, MangledName, Id, SingletonId, NumEls) \
3393	case BuiltinType::Id: \
3394	type_name = MangledName; \
3395	Out << (type_name == InternalName ? "u" : "") << type_name.size() \
3396	<< type_name; \
3397	break;
3398	#define SVE_OPAQUE_TYPE(InternalName, MangledName, Id, SingletonId) \
3399	case BuiltinType::Id: \
3400	type_name = MangledName; \
3401	Out << (type_name == InternalName ? "u" : "") << type_name.size() \
3402	<< type_name; \
3403	break;
3404	#include "clang/Basic/AArch64SVEACLETypes.def"
3405	#define PPC_VECTOR_TYPE(Name, Id, Size) \
3406	case BuiltinType::Id: \
3407	type_name = #Name; \
3408	Out << 'u' << type_name.size() << type_name; \
3409	break;
3410	#include "clang/Basic/PPCTypes.def"
3411	// TODO: Check the mangling scheme for RISC-V V.
3412	#define RVV_TYPE(Name, Id, SingletonId) \
3413	case BuiltinType::Id: \
3414	type_name = Name; \
3415	Out << 'u' << type_name.size() << type_name; \
3416	break;
3417	#include "clang/Basic/RISCVVTypes.def"
3418	#define WASM_REF_TYPE(InternalName, MangledName, Id, SingletonId, AS) \
3419	case BuiltinType::Id: \
3420	type_name = MangledName; \
3421	Out << 'u' << type_name.size() << type_name; \
3422	break;
3423	#include "clang/Basic/WebAssemblyReferenceTypes.def"
3424	}
3425	}
3426
3427	StringRef CXXNameMangler::getCallingConvQualifierName(CallingConv CC) {
3428	switch (CC) {
3429	case CC_C:
3430	return "";
3431
3432	case CC_X86VectorCall:
3433	case CC_X86Pascal:
3434	case CC_X86RegCall:
3435	case CC_AAPCS:
3436	case CC_AAPCS_VFP:
3437	case CC_AArch64VectorCall:
3438	case CC_AArch64SVEPCS:
3439	case CC_AMDGPUKernelCall:
3440	case CC_IntelOclBicc:
3441	case CC_SpirFunction:
3442	case CC_OpenCLKernel:
3443	case CC_PreserveMost:
3444	case CC_PreserveAll:
3445	case CC_M68kRTD:
3446	case CC_PreserveNone:
3447	// FIXME: we should be mangling all of the above.
3448	return "";
3449
3450	case CC_X86ThisCall:
3451	// FIXME: To match mingw GCC, thiscall should only be mangled in when it is
3452	// used explicitly. At this point, we don't have that much information in
3453	// the AST, since clang tends to bake the convention into the canonical
3454	// function type. thiscall only rarely used explicitly, so don't mangle it
3455	// for now.
3456	return "";
3457
3458	case CC_X86StdCall:
3459	return "stdcall";
3460	case CC_X86FastCall:
3461	return "fastcall";
3462	case CC_X86_64SysV:
3463	return "sysv_abi";
3464	case CC_Win64:
3465	return "ms_abi";
3466	case CC_Swift:
3467	return "swiftcall";
3468	case CC_SwiftAsync:
3469	return "swiftasynccall";
3470	}
3471	llvm_unreachable("bad calling convention");
3472	}
3473
3474	void CXXNameMangler::mangleExtFunctionInfo(const FunctionType *T) {
3475	// Fast path.
3476	if (T->getExtInfo() == FunctionType::ExtInfo())
3477	return;
3478
3479	// Vendor-specific qualifiers are emitted in reverse alphabetical order.
3480	// This will get more complicated in the future if we mangle other
3481	// things here; but for now, since we mangle ns_returns_retained as
3482	// a qualifier on the result type, we can get away with this:
3483	StringRef CCQualifier = getCallingConvQualifierName(CC: T->getExtInfo().getCC());
3484	if (!CCQualifier.empty())
3485	mangleVendorQualifier(name: CCQualifier);
3486
3487	// FIXME: regparm
3488	// FIXME: noreturn
3489	}
3490
3491	void
3492	CXXNameMangler::mangleExtParameterInfo(FunctionProtoType::ExtParameterInfo PI) {
3493	// Vendor-specific qualifiers are emitted in reverse alphabetical order.
3494
3495	// Note that these are *not* substitution candidates. Demanglers might
3496	// have trouble with this if the parameter type is fully substituted.
3497
3498	switch (PI.getABI()) {
3499	case ParameterABI::Ordinary:
3500	break;
3501
3502	// All of these start with "swift", so they come before "ns_consumed".
3503	case ParameterABI::SwiftContext:
3504	case ParameterABI::SwiftAsyncContext:
3505	case ParameterABI::SwiftErrorResult:
3506	case ParameterABI::SwiftIndirectResult:
3507	mangleVendorQualifier(name: getParameterABISpelling(kind: PI.getABI()));
3508	break;
3509	}
3510
3511	if (PI.isConsumed())
3512	mangleVendorQualifier(name: "ns_consumed");
3513
3514	if (PI.isNoEscape())
3515	mangleVendorQualifier(name: "noescape");
3516	}
3517
3518	// <type> ::= <function-type>
3519	// <function-type> ::= [<CV-qualifiers>] F [Y]
3520	// <bare-function-type> [<ref-qualifier>] E
3521	void CXXNameMangler::mangleType(const FunctionProtoType *T) {
3522	mangleExtFunctionInfo(T);
3523
3524	// Mangle CV-qualifiers, if present. These are 'this' qualifiers,
3525	// e.g. "const" in "int (A::*)() const".
3526	mangleQualifiers(Quals: T->getMethodQuals());
3527
3528	// Mangle instantiation-dependent exception-specification, if present,
3529	// per cxx-abi-dev proposal on 2016-10-11.
3530	if (T->hasInstantiationDependentExceptionSpec()) {
3531	if (isComputedNoexcept(ESpecType: T->getExceptionSpecType())) {
3532	Out << "DO";
3533	mangleExpression(E: T->getNoexceptExpr());
3534	Out << "E";
3535	} else {
3536	assert(T->getExceptionSpecType() == EST_Dynamic);
3537	Out << "Dw";
3538	for (auto ExceptTy : T->exceptions())
3539	mangleType(T: ExceptTy);
3540	Out << "E";
3541	}
3542	} else if (T->isNothrow()) {
3543	Out << "Do";
3544	}
3545
3546	Out << 'F';
3547
3548	// FIXME: We don't have enough information in the AST to produce the 'Y'
3549	// encoding for extern "C" function types.
3550	mangleBareFunctionType(T, /*MangleReturnType=*/true);
3551
3552	// Mangle the ref-qualifier, if present.
3553	mangleRefQualifier(RefQualifier: T->getRefQualifier());
3554
3555	Out << 'E';
3556	}
3557
3558	void CXXNameMangler::mangleType(const FunctionNoProtoType *T) {
3559	// Function types without prototypes can arise when mangling a function type
3560	// within an overloadable function in C. We mangle these as the absence of any
3561	// parameter types (not even an empty parameter list).
3562	Out << 'F';
3563
3564	FunctionTypeDepthState saved = FunctionTypeDepth.push();
3565
3566	FunctionTypeDepth.enterResultType();
3567	mangleType(T->getReturnType());
3568	FunctionTypeDepth.leaveResultType();
3569
3570	FunctionTypeDepth.pop(saved);
3571	Out << 'E';
3572	}
3573
3574	void CXXNameMangler::mangleBareFunctionType(const FunctionProtoType *Proto,
3575	bool MangleReturnType,
3576	const FunctionDecl *FD) {
3577	// Record that we're in a function type. See mangleFunctionParam
3578	// for details on what we're trying to achieve here.
3579	FunctionTypeDepthState saved = FunctionTypeDepth.push();
3580
3581	// <bare-function-type> ::= <signature type>+
3582	if (MangleReturnType) {
3583	FunctionTypeDepth.enterResultType();
3584
3585	// Mangle ns_returns_retained as an order-sensitive qualifier here.
3586	if (Proto->getExtInfo().getProducesResult() && FD == nullptr)
3587	mangleVendorQualifier(name: "ns_returns_retained");
3588
3589	// Mangle the return type without any direct ARC ownership qualifiers.
3590	QualType ReturnTy = Proto->getReturnType();
3591	if (ReturnTy.getObjCLifetime()) {
3592	auto SplitReturnTy = ReturnTy.split();
3593	SplitReturnTy.Quals.removeObjCLifetime();
3594	ReturnTy = getASTContext().getQualifiedType(SplitReturnTy);
3595	}
3596	mangleType(T: ReturnTy);
3597
3598	FunctionTypeDepth.leaveResultType();
3599	}
3600
3601	if (Proto->getNumParams() == 0 && !Proto->isVariadic()) {
3602	// <builtin-type> ::= v # void
3603	Out << 'v';
3604	} else {
3605	assert(!FD || FD->getNumParams() == Proto->getNumParams());
3606	for (unsigned I = 0, E = Proto->getNumParams(); I != E; ++I) {
3607	// Mangle extended parameter info as order-sensitive qualifiers here.
3608	if (Proto->hasExtParameterInfos() && FD == nullptr) {
3609	mangleExtParameterInfo(PI: Proto->getExtParameterInfo(I));
3610	}
3611
3612	// Mangle the type.
3613	QualType ParamTy = Proto->getParamType(i: I);
3614	mangleType(T: Context.getASTContext().getSignatureParameterType(T: ParamTy));
3615
3616	if (FD) {
3617	if (auto *Attr = FD->getParamDecl(I)->getAttr<PassObjectSizeAttr>()) {
3618	// Attr can only take 1 character, so we can hardcode the length
3619	// below.
3620	assert(Attr->getType() <= 9 && Attr->getType() >= 0);
3621	if (Attr->isDynamic())
3622	Out << "U25pass_dynamic_object_size" << Attr->getType();
3623	else
3624	Out << "U17pass_object_size" << Attr->getType();
3625	}
3626	}
3627	}
3628
3629	// <builtin-type> ::= z # ellipsis
3630	if (Proto->isVariadic())
3631	Out << 'z';
3632	}
3633
3634	if (FD) {
3635	FunctionTypeDepth.enterResultType();
3636	mangleRequiresClause(RequiresClause: FD->getTrailingRequiresClause());
3637	}
3638
3639	FunctionTypeDepth.pop(saved);
3640	}
3641
3642	// <type> ::= <class-enum-type>
3643	// <class-enum-type> ::= <name>
3644	void CXXNameMangler::mangleType(const UnresolvedUsingType *T) {
3645	mangleName(T->getDecl());
3646	}
3647
3648	// <type> ::= <class-enum-type>
3649	// <class-enum-type> ::= <name>
3650	void CXXNameMangler::mangleType(const EnumType *T) {
3651	mangleType(static_cast<const TagType*>(T));
3652	}
3653	void CXXNameMangler::mangleType(const RecordType *T) {
3654	mangleType(static_cast<const TagType*>(T));
3655	}
3656	void CXXNameMangler::mangleType(const TagType *T) {
3657	mangleName(T->getDecl());
3658	}
3659
3660	// <type> ::= <array-type>
3661	// <array-type> ::= A <positive dimension number> _ <element type>
3662	// ::= A [<dimension expression>] _ <element type>
3663	void CXXNameMangler::mangleType(const ConstantArrayType *T) {
3664	Out << 'A' << T->getSize() << '_';
3665	mangleType(T->getElementType());
3666	}
3667	void CXXNameMangler::mangleType(const VariableArrayType *T) {
3668	Out << 'A';
3669	// decayed vla types (size 0) will just be skipped.
3670	if (T->getSizeExpr())
3671	mangleExpression(E: T->getSizeExpr());
3672	Out << '_';
3673	mangleType(T->getElementType());
3674	}
3675	void CXXNameMangler::mangleType(const DependentSizedArrayType *T) {
3676	Out << 'A';
3677	// A DependentSizedArrayType might not have size expression as below
3678	//
3679	// template<int ...N> int arr[] = {N...};
3680	if (T->getSizeExpr())
3681	mangleExpression(E: T->getSizeExpr());
3682	Out << '_';
3683	mangleType(T->getElementType());
3684	}
3685	void CXXNameMangler::mangleType(const IncompleteArrayType *T) {
3686	Out << "A_";
3687	mangleType(T->getElementType());
3688	}
3689
3690	// <type> ::= <pointer-to-member-type>
3691	// <pointer-to-member-type> ::= M <class type> <member type>
3692	void CXXNameMangler::mangleType(const MemberPointerType *T) {
3693	Out << 'M';
3694	mangleType(T: QualType(T->getClass(), 0));
3695	QualType PointeeType = T->getPointeeType();
3696	if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(Val&: PointeeType)) {
3697	mangleType(FPT);
3698
3699	// Itanium C++ ABI 5.1.8:
3700	//
3701	// The type of a non-static member function is considered to be different,
3702	// for the purposes of substitution, from the type of a namespace-scope or
3703	// static member function whose type appears similar. The types of two
3704	// non-static member functions are considered to be different, for the
3705	// purposes of substitution, if the functions are members of different
3706	// classes. In other words, for the purposes of substitution, the class of
3707	// which the function is a member is considered part of the type of
3708	// function.
3709
3710	// Given that we already substitute member function pointers as a
3711	// whole, the net effect of this rule is just to unconditionally
3712	// suppress substitution on the function type in a member pointer.
3713	// We increment the SeqID here to emulate adding an entry to the
3714	// substitution table.
3715	++SeqID;
3716	} else
3717	mangleType(T: PointeeType);
3718	}
3719
3720	// <type> ::= <template-param>
3721	void CXXNameMangler::mangleType(const TemplateTypeParmType *T) {
3722	mangleTemplateParameter(Depth: T->getDepth(), Index: T->getIndex());
3723	}
3724
3725	// <type> ::= <template-param>
3726	void CXXNameMangler::mangleType(const SubstTemplateTypeParmPackType *T) {
3727	// FIXME: not clear how to mangle this!
3728	// template <class T...> class A {
3729	// template <class U...> void foo(T(*)(U) x...);
3730	// };
3731	Out << "_SUBSTPACK_";
3732	}
3733
3734	// <type> ::= P <type> # pointer-to
3735	void CXXNameMangler::mangleType(const PointerType *T) {
3736	Out << 'P';
3737	mangleType(T: T->getPointeeType());
3738	}
3739	void CXXNameMangler::mangleType(const ObjCObjectPointerType *T) {
3740	Out << 'P';
3741	mangleType(T: T->getPointeeType());
3742	}
3743
3744	// <type> ::= R <type> # reference-to
3745	void CXXNameMangler::mangleType(const LValueReferenceType *T) {
3746	Out << 'R';
3747	mangleType(T->getPointeeType());
3748	}
3749
3750	// <type> ::= O <type> # rvalue reference-to (C++0x)
3751	void CXXNameMangler::mangleType(const RValueReferenceType *T) {
3752	Out << 'O';
3753	mangleType(T->getPointeeType());
3754	}
3755
3756	// <type> ::= C <type> # complex pair (C 2000)
3757	void CXXNameMangler::mangleType(const ComplexType *T) {
3758	Out << 'C';
3759	mangleType(T: T->getElementType());
3760	}
3761
3762	// ARM's ABI for Neon vector types specifies that they should be mangled as
3763	// if they are structs (to match ARM's initial implementation). The
3764	// vector type must be one of the special types predefined by ARM.
3765	void CXXNameMangler::mangleNeonVectorType(const VectorType *T) {
3766	QualType EltType = T->getElementType();
3767	assert(EltType->isBuiltinType() && "Neon vector element not a BuiltinType");
3768	const char *EltName = nullptr;
3769	if (T->getVectorKind() == VectorKind::NeonPoly) {
3770	switch (cast<BuiltinType>(Val&: EltType)->getKind()) {
3771	case BuiltinType::SChar:
3772	case BuiltinType::UChar:
3773	EltName = "poly8_t";
3774	break;
3775	case BuiltinType::Short:
3776	case BuiltinType::UShort:
3777	EltName = "poly16_t";
3778	break;
3779	case BuiltinType::LongLong:
3780	case BuiltinType::ULongLong:
3781	EltName = "poly64_t";
3782	break;
3783	default: llvm_unreachable("unexpected Neon polynomial vector element type");
3784	}
3785	} else {
3786	switch (cast<BuiltinType>(Val&: EltType)->getKind()) {
3787	case BuiltinType::SChar: EltName = "int8_t"; break;
3788	case BuiltinType::UChar: EltName = "uint8_t"; break;
3789	case BuiltinType::Short: EltName = "int16_t"; break;
3790	case BuiltinType::UShort: EltName = "uint16_t"; break;
3791	case BuiltinType::Int: EltName = "int32_t"; break;
3792	case BuiltinType::UInt: EltName = "uint32_t"; break;
3793	case BuiltinType::LongLong: EltName = "int64_t"; break;
3794	case BuiltinType::ULongLong: EltName = "uint64_t"; break;
3795	case BuiltinType::Double: EltName = "float64_t"; break;
3796	case BuiltinType::Float: EltName = "float32_t"; break;
3797	case BuiltinType::Half: EltName = "float16_t"; break;
3798	case BuiltinType::BFloat16: EltName = "bfloat16_t"; break;
3799	default:
3800	llvm_unreachable("unexpected Neon vector element type");
3801	}
3802	}
3803	const char *BaseName = nullptr;
3804	unsigned BitSize = (T->getNumElements() *
3805	getASTContext().getTypeSize(T: EltType));
3806	if (BitSize == 64)
3807	BaseName = "__simd64_";
3808	else {
3809	assert(BitSize == 128 && "Neon vector type not 64 or 128 bits");
3810	BaseName = "__simd128_";
3811	}
3812	Out << strlen(s: BaseName) + strlen(s: EltName);
3813	Out << BaseName << EltName;
3814	}
3815
3816	void CXXNameMangler::mangleNeonVectorType(const DependentVectorType *T) {
3817	DiagnosticsEngine &Diags = Context.getDiags();
3818	unsigned DiagID = Diags.getCustomDiagID(
3819	L: DiagnosticsEngine::Error,
3820	FormatString: "cannot mangle this dependent neon vector type yet");
3821	Diags.Report(Loc: T->getAttributeLoc(), DiagID);
3822	}
3823
3824	static StringRef mangleAArch64VectorBase(const BuiltinType *EltType) {
3825	switch (EltType->getKind()) {
3826	case BuiltinType::SChar:
3827	return "Int8";
3828	case BuiltinType::Short:
3829	return "Int16";
3830	case BuiltinType::Int:
3831	return "Int32";
3832	case BuiltinType::Long:
3833	case BuiltinType::LongLong:
3834	return "Int64";
3835	case BuiltinType::UChar:
3836	return "Uint8";
3837	case BuiltinType::UShort:
3838	return "Uint16";
3839	case BuiltinType::UInt:
3840	return "Uint32";
3841	case BuiltinType::ULong:
3842	case BuiltinType::ULongLong:
3843	return "Uint64";
3844	case BuiltinType::Half:
3845	return "Float16";
3846	case BuiltinType::Float:
3847	return "Float32";
3848	case BuiltinType::Double:
3849	return "Float64";
3850	case BuiltinType::BFloat16:
3851	return "Bfloat16";
3852	default:
3853	llvm_unreachable("Unexpected vector element base type");
3854	}
3855	}
3856
3857	// AArch64's ABI for Neon vector types specifies that they should be mangled as
3858	// the equivalent internal name. The vector type must be one of the special
3859	// types predefined by ARM.
3860	void CXXNameMangler::mangleAArch64NeonVectorType(const VectorType *T) {
3861	QualType EltType = T->getElementType();
3862	assert(EltType->isBuiltinType() && "Neon vector element not a BuiltinType");
3863	unsigned BitSize =
3864	(T->getNumElements() * getASTContext().getTypeSize(T: EltType));
3865	(void)BitSize; // Silence warning.
3866
3867	assert((BitSize == 64 || BitSize == 128) &&
3868	"Neon vector type not 64 or 128 bits");
3869
3870	StringRef EltName;
3871	if (T->getVectorKind() == VectorKind::NeonPoly) {
3872	switch (cast<BuiltinType>(Val&: EltType)->getKind()) {
3873	case BuiltinType::UChar:
3874	EltName = "Poly8";
3875	break;
3876	case BuiltinType::UShort:
3877	EltName = "Poly16";
3878	break;
3879	case BuiltinType::ULong:
3880	case BuiltinType::ULongLong:
3881	EltName = "Poly64";
3882	break;
3883	default:
3884	llvm_unreachable("unexpected Neon polynomial vector element type");
3885	}
3886	} else
3887	EltName = mangleAArch64VectorBase(EltType: cast<BuiltinType>(Val&: EltType));
3888
3889	std::string TypeName =
3890	("__" + EltName + "x" + Twine(T->getNumElements()) + "_t").str();
3891	Out << TypeName.length() << TypeName;
3892	}
3893	void CXXNameMangler::mangleAArch64NeonVectorType(const DependentVectorType *T) {
3894	DiagnosticsEngine &Diags = Context.getDiags();
3895	unsigned DiagID = Diags.getCustomDiagID(
3896	L: DiagnosticsEngine::Error,
3897	FormatString: "cannot mangle this dependent neon vector type yet");
3898	Diags.Report(Loc: T->getAttributeLoc(), DiagID);
3899	}
3900
3901	// The AArch64 ACLE specifies that fixed-length SVE vector and predicate types
3902	// defined with the 'arm_sve_vector_bits' attribute map to the same AAPCS64
3903	// type as the sizeless variants.
3904	//
3905	// The mangling scheme for VLS types is implemented as a "pseudo" template:
3906	//
3907	// '__SVE_VLS<<type>, <vector length>>'
3908	//
3909	// Combining the existing SVE type and a specific vector length (in bits).
3910	// For example:
3911	//
3912	// typedef __SVInt32_t foo __attribute__((arm_sve_vector_bits(512)));
3913	//
3914	// is described as '__SVE_VLS<__SVInt32_t, 512u>' and mangled as:
3915	//
3916	// "9__SVE_VLSI" + base type mangling + "Lj" + __ARM_FEATURE_SVE_BITS + "EE"
3917	//
3918	// i.e. 9__SVE_VLSIu11__SVInt32_tLj512EE
3919	//
3920	// The latest ACLE specification (00bet5) does not contain details of this
3921	// mangling scheme, it will be specified in the next revision. The mangling
3922	// scheme is otherwise defined in the appendices to the Procedure Call Standard
3923	// for the Arm Architecture, see
3924	// https://github.com/ARM-software/abi-aa/blob/main/aapcs64/aapcs64.rst#appendix-c-mangling
3925	void CXXNameMangler::mangleAArch64FixedSveVectorType(const VectorType *T) {
3926	assert((T->getVectorKind() == VectorKind::SveFixedLengthData ||
3927	T->getVectorKind() == VectorKind::SveFixedLengthPredicate) &&
3928	"expected fixed-length SVE vector!");
3929
3930	QualType EltType = T->getElementType();
3931	assert(EltType->isBuiltinType() &&
3932	"expected builtin type for fixed-length SVE vector!");
3933
3934	StringRef TypeName;
3935	switch (cast<BuiltinType>(Val&: EltType)->getKind()) {
3936	case BuiltinType::SChar:
3937	TypeName = "__SVInt8_t";
3938	break;
3939	case BuiltinType::UChar: {
3940	if (T->getVectorKind() == VectorKind::SveFixedLengthData)
3941	TypeName = "__SVUint8_t";
3942	else
3943	TypeName = "__SVBool_t";
3944	break;
3945	}
3946	case BuiltinType::Short:
3947	TypeName = "__SVInt16_t";
3948	break;
3949	case BuiltinType::UShort:
3950	TypeName = "__SVUint16_t";
3951	break;
3952	case BuiltinType::Int:
3953	TypeName = "__SVInt32_t";
3954	break;
3955	case BuiltinType::UInt:
3956	TypeName = "__SVUint32_t";
3957	break;
3958	case BuiltinType::Long:
3959	TypeName = "__SVInt64_t";
3960	break;
3961	case BuiltinType::ULong:
3962	TypeName = "__SVUint64_t";
3963	break;
3964	case BuiltinType::Half:
3965	TypeName = "__SVFloat16_t";
3966	break;
3967	case BuiltinType::Float:
3968	TypeName = "__SVFloat32_t";
3969	break;
3970	case BuiltinType::Double:
3971	TypeName = "__SVFloat64_t";
3972	break;
3973	case BuiltinType::BFloat16:
3974	TypeName = "__SVBfloat16_t";
3975	break;
3976	default:
3977	llvm_unreachable("unexpected element type for fixed-length SVE vector!");
3978	}
3979
3980	unsigned VecSizeInBits = getASTContext().getTypeInfo(T).Width;
3981
3982	if (T->getVectorKind() == VectorKind::SveFixedLengthPredicate)
3983	VecSizeInBits *= 8;
3984
3985	Out << "9__SVE_VLSI" << 'u' << TypeName.size() << TypeName << "Lj"
3986	<< VecSizeInBits << "EE";
3987	}
3988
3989	void CXXNameMangler::mangleAArch64FixedSveVectorType(
3990	const DependentVectorType *T) {
3991	DiagnosticsEngine &Diags = Context.getDiags();
3992	unsigned DiagID = Diags.getCustomDiagID(
3993	L: DiagnosticsEngine::Error,
3994	FormatString: "cannot mangle this dependent fixed-length SVE vector type yet");
3995	Diags.Report(Loc: T->getAttributeLoc(), DiagID);
3996	}
3997
3998	void CXXNameMangler::mangleRISCVFixedRVVVectorType(const VectorType *T) {
3999	assert((T->getVectorKind() == VectorKind::RVVFixedLengthData ||
4000	T->getVectorKind() == VectorKind::RVVFixedLengthMask) &&
4001	"expected fixed-length RVV vector!");
4002
4003	QualType EltType = T->getElementType();
4004	assert(EltType->isBuiltinType() &&
4005	"expected builtin type for fixed-length RVV vector!");
4006
4007	SmallString<20> TypeNameStr;
4008	llvm::raw_svector_ostream TypeNameOS(TypeNameStr);
4009	TypeNameOS << "__rvv_";
4010	switch (cast<BuiltinType>(Val&: EltType)->getKind()) {
4011	case BuiltinType::SChar:
4012	TypeNameOS << "int8";
4013	break;
4014	case BuiltinType::UChar:
4015	if (T->getVectorKind() == VectorKind::RVVFixedLengthData)
4016	TypeNameOS << "uint8";
4017	else
4018	TypeNameOS << "bool";
4019	break;
4020	case BuiltinType::Short:
4021	TypeNameOS << "int16";
4022	break;
4023	case BuiltinType::UShort:
4024	TypeNameOS << "uint16";
4025	break;
4026	case BuiltinType::Int:
4027	TypeNameOS << "int32";
4028	break;
4029	case BuiltinType::UInt:
4030	TypeNameOS << "uint32";
4031	break;
4032	case BuiltinType::Long:
4033	TypeNameOS << "int64";
4034	break;
4035	case BuiltinType::ULong:
4036	TypeNameOS << "uint64";
4037	break;
4038	case BuiltinType::Float16:
4039	TypeNameOS << "float16";
4040	break;
4041	case BuiltinType::Float:
4042	TypeNameOS << "float32";
4043	break;
4044	case BuiltinType::Double:
4045	TypeNameOS << "float64";
4046	break;
4047	default:
4048	llvm_unreachable("unexpected element type for fixed-length RVV vector!");
4049	}
4050
4051	unsigned VecSizeInBits = getASTContext().getTypeInfo(T).Width;
4052
4053	// Apend the LMUL suffix.
4054	auto VScale = getASTContext().getTargetInfo().getVScaleRange(
4055	LangOpts: getASTContext().getLangOpts());
4056	unsigned VLen = VScale->first * llvm::RISCV::RVVBitsPerBlock;
4057
4058	if (T->getVectorKind() == VectorKind::RVVFixedLengthData) {
4059	TypeNameOS << 'm';
4060	if (VecSizeInBits >= VLen)
4061	TypeNameOS << (VecSizeInBits / VLen);
4062	else
4063	TypeNameOS << 'f' << (VLen / VecSizeInBits);
4064	} else {
4065	TypeNameOS << (VLen / VecSizeInBits);
4066	}
4067	TypeNameOS << "_t";
4068
4069	Out << "9__RVV_VLSI" << 'u' << TypeNameStr.size() << TypeNameStr << "Lj"
4070	<< VecSizeInBits << "EE";
4071	}
4072
4073	void CXXNameMangler::mangleRISCVFixedRVVVectorType(
4074	const DependentVectorType *T) {
4075	DiagnosticsEngine &Diags = Context.getDiags();
4076	unsigned DiagID = Diags.getCustomDiagID(
4077	L: DiagnosticsEngine::Error,
4078	FormatString: "cannot mangle this dependent fixed-length RVV vector type yet");
4079	Diags.Report(Loc: T->getAttributeLoc(), DiagID);
4080	}
4081
4082	// GNU extension: vector types
4083	// <type> ::= <vector-type>
4084	// <vector-type> ::= Dv <positive dimension number> _
4085	// <extended element type>
4086	// ::= Dv [<dimension expression>] _ <element type>
4087	// <extended element type> ::= <element type>
4088	// ::= p # AltiVec vector pixel
4089	// ::= b # Altivec vector bool
4090	void CXXNameMangler::mangleType(const VectorType *T) {
4091	if ((T->getVectorKind() == VectorKind::Neon ||
4092	T->getVectorKind() == VectorKind::NeonPoly)) {
4093	llvm::Triple Target = getASTContext().getTargetInfo().getTriple();
4094	llvm::Triple::ArchType Arch =
4095	getASTContext().getTargetInfo().getTriple().getArch();
4096	if ((Arch == llvm::Triple::aarch64 ||
4097	Arch == llvm::Triple::aarch64_be) && !Target.isOSDarwin())
4098	mangleAArch64NeonVectorType(T);
4099	else
4100	mangleNeonVectorType(T);
4101	return;
4102	} else if (T->getVectorKind() == VectorKind::SveFixedLengthData ||
4103	T->getVectorKind() == VectorKind::SveFixedLengthPredicate) {
4104	mangleAArch64FixedSveVectorType(T);
4105	return;
4106	} else if (T->getVectorKind() == VectorKind::RVVFixedLengthData ||
4107	T->getVectorKind() == VectorKind::RVVFixedLengthMask) {
4108	mangleRISCVFixedRVVVectorType(T);
4109	return;
4110	}
4111	Out << "Dv" << T->getNumElements() << '_';
4112	if (T->getVectorKind() == VectorKind::AltiVecPixel)
4113	Out << 'p';
4114	else if (T->getVectorKind() == VectorKind::AltiVecBool)
4115	Out << 'b';
4116	else
4117	mangleType(T: T->getElementType());
4118	}
4119
4120	void CXXNameMangler::mangleType(const DependentVectorType *T) {
4121	if ((T->getVectorKind() == VectorKind::Neon ||
4122	T->getVectorKind() == VectorKind::NeonPoly)) {
4123	llvm::Triple Target = getASTContext().getTargetInfo().getTriple();
4124	llvm::Triple::ArchType Arch =
4125	getASTContext().getTargetInfo().getTriple().getArch();
4126	if ((Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::aarch64_be) &&
4127	!Target.isOSDarwin())
4128	mangleAArch64NeonVectorType(T);
4129	else
4130	mangleNeonVectorType(T);
4131	return;
4132	} else if (T->getVectorKind() == VectorKind::SveFixedLengthData ||
4133	T->getVectorKind() == VectorKind::SveFixedLengthPredicate) {
4134	mangleAArch64FixedSveVectorType(T);
4135	return;
4136	} else if (T->getVectorKind() == VectorKind::RVVFixedLengthData) {
4137	mangleRISCVFixedRVVVectorType(T);
4138	return;
4139	}
4140
4141	Out << "Dv";
4142	mangleExpression(E: T->getSizeExpr());
4143	Out << '_';
4144	if (T->getVectorKind() == VectorKind::AltiVecPixel)
4145	Out << 'p';
4146	else if (T->getVectorKind() == VectorKind::AltiVecBool)
4147	Out << 'b';
4148	else
4149	mangleType(T: T->getElementType());
4150	}
4151
4152	void CXXNameMangler::mangleType(const ExtVectorType *T) {
4153	mangleType(static_cast<const VectorType*>(T));
4154	}
4155	void CXXNameMangler::mangleType(const DependentSizedExtVectorType *T) {
4156	Out << "Dv";
4157	mangleExpression(E: T->getSizeExpr());
4158	Out << '_';
4159	mangleType(T: T->getElementType());
4160	}
4161
4162	void CXXNameMangler::mangleType(const ConstantMatrixType *T) {
4163	// Mangle matrix types as a vendor extended type:
4164	// u<Len>matrix_typeI<Rows><Columns><element type>E
4165
4166	StringRef VendorQualifier = "matrix_type";
4167	Out << "u" << VendorQualifier.size() << VendorQualifier;
4168
4169	Out << "I";
4170	auto &ASTCtx = getASTContext();
4171	unsigned BitWidth = ASTCtx.getTypeSize(T: ASTCtx.getSizeType());
4172	llvm::APSInt Rows(BitWidth);
4173	Rows = T->getNumRows();
4174	mangleIntegerLiteral(T: ASTCtx.getSizeType(), Value: Rows);
4175	llvm::APSInt Columns(BitWidth);
4176	Columns = T->getNumColumns();
4177	mangleIntegerLiteral(T: ASTCtx.getSizeType(), Value: Columns);
4178	mangleType(T->getElementType());
4179	Out << "E";
4180	}
4181
4182	void CXXNameMangler::mangleType(const DependentSizedMatrixType *T) {
4183	// Mangle matrix types as a vendor extended type:
4184	// u<Len>matrix_typeI<row expr><column expr><element type>E
4185	StringRef VendorQualifier = "matrix_type";
4186	Out << "u" << VendorQualifier.size() << VendorQualifier;
4187
4188	Out << "I";
4189	mangleTemplateArgExpr(E: T->getRowExpr());
4190	mangleTemplateArgExpr(E: T->getColumnExpr());
4191	mangleType(T->getElementType());
4192	Out << "E";
4193	}
4194
4195	void CXXNameMangler::mangleType(const DependentAddressSpaceType *T) {
4196	SplitQualType split = T->getPointeeType().split();
4197	mangleQualifiers(Quals: split.Quals, DAST: T);
4198	mangleType(T: QualType(split.Ty, 0));
4199	}
4200
4201	void CXXNameMangler::mangleType(const PackExpansionType *T) {
4202	// <type> ::= Dp <type> # pack expansion (C++0x)
4203	Out << "Dp";
4204	mangleType(T: T->getPattern());
4205	}
4206
4207	void CXXNameMangler::mangleType(const PackIndexingType *T) {
4208	if (!T->hasSelectedType())
4209	mangleType(T: T->getPattern());
4210	else
4211	mangleType(T: T->getSelectedType());
4212	}
4213
4214	void CXXNameMangler::mangleType(const ObjCInterfaceType *T) {
4215	mangleSourceName(II: T->getDecl()->getIdentifier());
4216	}
4217
4218	void CXXNameMangler::mangleType(const ObjCObjectType *T) {
4219	// Treat __kindof as a vendor extended type qualifier.
4220	if (T->isKindOfType())
4221	Out << "U8__kindof";
4222
4223	if (!T->qual_empty()) {
4224	// Mangle protocol qualifiers.
4225	SmallString<64> QualStr;
4226	llvm::raw_svector_ostream QualOS(QualStr);
4227	QualOS << "objcproto";
4228	for (const auto *I : T->quals()) {
4229	StringRef name = I->getName();
4230	QualOS << name.size() << name;
4231	}
4232	Out << 'U' << QualStr.size() << QualStr;
4233	}
4234
4235	mangleType(T: T->getBaseType());
4236
4237	if (T->isSpecialized()) {
4238	// Mangle type arguments as I <type>+ E
4239	Out << 'I';
4240	for (auto typeArg : T->getTypeArgs())
4241	mangleType(T: typeArg);
4242	Out << 'E';
4243	}
4244	}
4245
4246	void CXXNameMangler::mangleType(const BlockPointerType *T) {
4247	Out << "U13block_pointer";
4248	mangleType(T: T->getPointeeType());
4249	}
4250
4251	void CXXNameMangler::mangleType(const InjectedClassNameType *T) {
4252	// Mangle injected class name types as if the user had written the
4253	// specialization out fully. It may not actually be possible to see
4254	// this mangling, though.
4255	mangleType(T: T->getInjectedSpecializationType());
4256	}
4257
4258	void CXXNameMangler::mangleType(const TemplateSpecializationType *T) {
4259	if (TemplateDecl *TD = T->getTemplateName().getAsTemplateDecl()) {
4260	mangleTemplateName(TD, Args: T->template_arguments());
4261	} else {
4262	if (mangleSubstitution(T: QualType(T, 0)))
4263	return;
4264
4265	mangleTemplatePrefix(Template: T->getTemplateName());
4266
4267	// FIXME: GCC does not appear to mangle the template arguments when
4268	// the template in question is a dependent template name. Should we
4269	// emulate that badness?
4270	mangleTemplateArgs(TN: T->getTemplateName(), Args: T->template_arguments());
4271	addSubstitution(T: QualType(T, 0));
4272	}
4273	}
4274
4275	void CXXNameMangler::mangleType(const DependentNameType *T) {
4276	// Proposal by cxx-abi-dev, 2014-03-26
4277	// <class-enum-type> ::= <name> # non-dependent or dependent type name or
4278	// # dependent elaborated type specifier using
4279	// # 'typename'
4280	// ::= Ts <name> # dependent elaborated type specifier using
4281	// # 'struct' or 'class'
4282	// ::= Tu <name> # dependent elaborated type specifier using
4283	// # 'union'
4284	// ::= Te <name> # dependent elaborated type specifier using
4285	// # 'enum'
4286	switch (T->getKeyword()) {
4287	case ElaboratedTypeKeyword::None:
4288	case ElaboratedTypeKeyword::Typename:
4289	break;
4290	case ElaboratedTypeKeyword::Struct:
4291	case ElaboratedTypeKeyword::Class:
4292	case ElaboratedTypeKeyword::Interface:
4293	Out << "Ts";
4294	break;
4295	case ElaboratedTypeKeyword::Union:
4296	Out << "Tu";
4297	break;
4298	case ElaboratedTypeKeyword::Enum:
4299	Out << "Te";
4300	break;
4301	}
4302	// Typename types are always nested
4303	Out << 'N';
4304	manglePrefix(qualifier: T->getQualifier());
4305	mangleSourceName(II: T->getIdentifier());
4306	Out << 'E';
4307	}
4308
4309	void CXXNameMangler::mangleType(const DependentTemplateSpecializationType *T) {
4310	// Dependently-scoped template types are nested if they have a prefix.
4311	Out << 'N';
4312
4313	// TODO: avoid making this TemplateName.
4314	TemplateName Prefix =
4315	getASTContext().getDependentTemplateName(NNS: T->getQualifier(),
4316	Name: T->getIdentifier());
4317	mangleTemplatePrefix(Template: Prefix);
4318
4319	// FIXME: GCC does not appear to mangle the template arguments when
4320	// the template in question is a dependent template name. Should we
4321	// emulate that badness?
4322	mangleTemplateArgs(TN: Prefix, Args: T->template_arguments());
4323	Out << 'E';
4324	}
4325
4326	void CXXNameMangler::mangleType(const TypeOfType *T) {
4327	// FIXME: this is pretty unsatisfactory, but there isn't an obvious
4328	// "extension with parameters" mangling.
4329	Out << "u6typeof";
4330	}
4331
4332	void CXXNameMangler::mangleType(const TypeOfExprType *T) {
4333	// FIXME: this is pretty unsatisfactory, but there isn't an obvious
4334	// "extension with parameters" mangling.
4335	Out << "u6typeof";
4336	}
4337
4338	void CXXNameMangler::mangleType(const DecltypeType *T) {
4339	Expr *E = T->getUnderlyingExpr();
4340
4341	// type ::= Dt <expression> E # decltype of an id-expression
4342	// # or class member access
4343	// ::= DT <expression> E # decltype of an expression
4344
4345	// This purports to be an exhaustive list of id-expressions and
4346	// class member accesses. Note that we do not ignore parentheses;
4347	// parentheses change the semantics of decltype for these
4348	// expressions (and cause the mangler to use the other form).
4349	if (isa<DeclRefExpr>(Val: E) ||
4350	isa<MemberExpr>(Val: E) ||
4351	isa<UnresolvedLookupExpr>(Val: E) ||
4352	isa<DependentScopeDeclRefExpr>(Val: E) ||
4353	isa<CXXDependentScopeMemberExpr>(Val: E) ||
4354	isa<UnresolvedMemberExpr>(Val: E))
4355	Out << "Dt";
4356	else
4357	Out << "DT";
4358	mangleExpression(E);
4359	Out << 'E';
4360	}
4361
4362	void CXXNameMangler::mangleType(const UnaryTransformType *T) {
4363	// If this is dependent, we need to record that. If not, we simply
4364	// mangle it as the underlying type since they are equivalent.
4365	if (T->isDependentType()) {
4366	Out << "u";
4367
4368	StringRef BuiltinName;
4369	switch (T->getUTTKind()) {
4370	#define TRANSFORM_TYPE_TRAIT_DEF(Enum, Trait) \
4371	case UnaryTransformType::Enum: \
4372	BuiltinName = "__" #Trait; \
4373	break;
4374	#include "clang/Basic/TransformTypeTraits.def"
4375	}
4376	Out << BuiltinName.size() << BuiltinName;
4377	}
4378
4379	Out << "I";
4380	mangleType(T: T->getBaseType());
4381	Out << "E";
4382	}
4383
4384	void CXXNameMangler::mangleType(const AutoType *T) {
4385	assert(T->getDeducedType().isNull() &&
4386	"Deduced AutoType shouldn't be handled here!");
4387	assert(T->getKeyword() != AutoTypeKeyword::GNUAutoType &&
4388	"shouldn't need to mangle __auto_type!");
4389	// <builtin-type> ::= Da # auto
4390	// ::= Dc # decltype(auto)
4391	// ::= Dk # constrained auto
4392	// ::= DK # constrained decltype(auto)
4393	if (T->isConstrained() && !isCompatibleWith(Ver: LangOptions::ClangABI::Ver17)) {
4394	Out << (T->isDecltypeAuto() ? "DK" : "Dk");
4395	mangleTypeConstraint(Concept: T->getTypeConstraintConcept(),
4396	Arguments: T->getTypeConstraintArguments());
4397	} else {
4398	Out << (T->isDecltypeAuto() ? "Dc" : "Da");
4399	}
4400	}
4401
4402	void CXXNameMangler::mangleType(const DeducedTemplateSpecializationType *T) {
4403	QualType Deduced = T->getDeducedType();
4404	if (!Deduced.isNull())
4405	return mangleType(T: Deduced);
4406
4407	TemplateDecl *TD = T->getTemplateName().getAsTemplateDecl();
4408	assert(TD && "shouldn't form deduced TST unless we know we have a template");
4409
4410	if (mangleSubstitution(TD))
4411	return;
4412
4413	mangleName(GD: GlobalDecl(TD));
4414	addSubstitution(TD);
4415	}
4416
4417	void CXXNameMangler::mangleType(const AtomicType *T) {
4418	// <type> ::= U <source-name> <type> # vendor extended type qualifier
4419	// (Until there's a standardized mangling...)
4420	Out << "U7_Atomic";
4421	mangleType(T: T->getValueType());
4422	}
4423
4424	void CXXNameMangler::mangleType(const PipeType *T) {
4425	// Pipe type mangling rules are described in SPIR 2.0 specification
4426	// A.1 Data types and A.3 Summary of changes
4427	// <type> ::= 8ocl_pipe
4428	Out << "8ocl_pipe";
4429	}
4430
4431	void CXXNameMangler::mangleType(const BitIntType *T) {
4432	// 5.1.5.2 Builtin types
4433	// <type> ::= DB <number | instantiation-dependent expression> _
4434	// ::= DU <number | instantiation-dependent expression> _
4435	Out << "D" << (T->isUnsigned() ? "U" : "B") << T->getNumBits() << "_";
4436	}
4437
4438	void CXXNameMangler::mangleType(const DependentBitIntType *T) {
4439	// 5.1.5.2 Builtin types
4440	// <type> ::= DB <number | instantiation-dependent expression> _
4441	// ::= DU <number | instantiation-dependent expression> _
4442	Out << "D" << (T->isUnsigned() ? "U" : "B");
4443	mangleExpression(E: T->getNumBitsExpr());
4444	Out << "_";
4445	}
4446
4447	void CXXNameMangler::mangleIntegerLiteral(QualType T,
4448	const llvm::APSInt &Value) {
4449	// <expr-primary> ::= L <type> <value number> E # integer literal
4450	Out << 'L';
4451
4452	mangleType(T);
4453	if (T->isBooleanType()) {
4454	// Boolean values are encoded as 0/1.
4455	Out << (Value.getBoolValue() ? '1' : '0');
4456	} else {
4457	mangleNumber(Value);
4458	}
4459	Out << 'E';
4460
4461	}
4462
4463	void CXXNameMangler::mangleMemberExprBase(const Expr *Base, bool IsArrow) {
4464	// Ignore member expressions involving anonymous unions.
4465	while (const auto *RT = Base->getType()->getAs<RecordType>()) {
4466	if (!RT->getDecl()->isAnonymousStructOrUnion())
4467	break;
4468	const auto *ME = dyn_cast<MemberExpr>(Val: Base);
4469	if (!ME)
4470	break;
4471	Base = ME->getBase();
4472	IsArrow = ME->isArrow();
4473	}
4474
4475	if (Base->isImplicitCXXThis()) {
4476	// Note: GCC mangles member expressions to the implicit 'this' as
4477	// *this., whereas we represent them as this->. The Itanium C++ ABI
4478	// does not specify anything here, so we follow GCC.
4479	Out << "dtdefpT";
4480	} else {
4481	Out << (IsArrow ? "pt" : "dt");
4482	mangleExpression(E: Base);
4483	}
4484	}
4485
4486	/// Mangles a member expression.
4487	void CXXNameMangler::mangleMemberExpr(const Expr *base,
4488	bool isArrow,
4489	NestedNameSpecifier *qualifier,
4490	NamedDecl *firstQualifierLookup,
4491	DeclarationName member,
4492	const TemplateArgumentLoc *TemplateArgs,
4493	unsigned NumTemplateArgs,
4494	unsigned arity) {
4495	// <expression> ::= dt <expression> <unresolved-name>
4496	// ::= pt <expression> <unresolved-name>
4497	if (base)
4498	mangleMemberExprBase(Base: base, IsArrow: isArrow);
4499	mangleUnresolvedName(qualifier, name: member, TemplateArgs, NumTemplateArgs, knownArity: arity);
4500	}
4501
4502	/// Look at the callee of the given call expression and determine if
4503	/// it's a parenthesized id-expression which would have triggered ADL
4504	/// otherwise.
4505	static bool isParenthesizedADLCallee(const CallExpr *call) {
4506	const Expr *callee = call->getCallee();
4507	const Expr *fn = callee->IgnoreParens();
4508
4509	// Must be parenthesized. IgnoreParens() skips __extension__ nodes,
4510	// too, but for those to appear in the callee, it would have to be
4511	// parenthesized.
4512	if (callee == fn) return false;
4513
4514	// Must be an unresolved lookup.
4515	const UnresolvedLookupExpr *lookup = dyn_cast<UnresolvedLookupExpr>(Val: fn);
4516	if (!lookup) return false;
4517
4518	assert(!lookup->requiresADL());
4519
4520	// Must be an unqualified lookup.
4521	if (lookup->getQualifier()) return false;
4522
4523	// Must not have found a class member. Note that if one is a class
4524	// member, they're all class members.
4525	if (lookup->getNumDecls() > 0 &&
4526	(*lookup->decls_begin())->isCXXClassMember())
4527	return false;
4528
4529	// Otherwise, ADL would have been triggered.
4530	return true;
4531	}
4532
4533	void CXXNameMangler::mangleCastExpression(const Expr *E, StringRef CastEncoding) {
4534	const ExplicitCastExpr *ECE = cast<ExplicitCastExpr>(Val: E);
4535	Out << CastEncoding;
4536	mangleType(ECE->getType());
4537	mangleExpression(E: ECE->getSubExpr());
4538	}
4539
4540	void CXXNameMangler::mangleInitListElements(const InitListExpr *InitList) {
4541	if (auto *Syntactic = InitList->getSyntacticForm())
4542	InitList = Syntactic;
4543	for (unsigned i = 0, e = InitList->getNumInits(); i != e; ++i)
4544	mangleExpression(E: InitList->getInit(Init: i));
4545	}
4546
4547	void CXXNameMangler::mangleRequirement(SourceLocation RequiresExprLoc,
4548	const concepts::Requirement *Req) {
4549	using concepts::Requirement;
4550
4551	// TODO: We can't mangle the result of a failed substitution. It's not clear
4552	// whether we should be mangling the original form prior to any substitution
4553	// instead. See https://lists.isocpp.org/core/2023/04/14118.php
4554	auto HandleSubstitutionFailure =
4555	[&](SourceLocation Loc) {
4556	DiagnosticsEngine &Diags = Context.getDiags();
4557	unsigned DiagID = Diags.getCustomDiagID(
4558	L: DiagnosticsEngine::Error, FormatString: "cannot mangle this requires-expression "
4559	"containing a substitution failure");
4560	Diags.Report(Loc, DiagID);
4561	Out << 'F';
4562	};
4563
4564	switch (Req->getKind()) {
4565	case Requirement::RK_Type: {
4566	const auto *TR = cast<concepts::TypeRequirement>(Val: Req);
4567	if (TR->isSubstitutionFailure())
4568	return HandleSubstitutionFailure(
4569	TR->getSubstitutionDiagnostic()->DiagLoc);
4570
4571	Out << 'T';
4572	mangleType(T: TR->getType()->getType());
4573	break;
4574	}
4575
4576	case Requirement::RK_Simple:
4577	case Requirement::RK_Compound: {
4578	const auto *ER = cast<concepts::ExprRequirement>(Val: Req);
4579	if (ER->isExprSubstitutionFailure())
4580	return HandleSubstitutionFailure(
4581	ER->getExprSubstitutionDiagnostic()->DiagLoc);
4582
4583	Out << 'X';
4584	mangleExpression(E: ER->getExpr());
4585
4586	if (ER->hasNoexceptRequirement())
4587	Out << 'N';
4588
4589	if (!ER->getReturnTypeRequirement().isEmpty()) {
4590	if (ER->getReturnTypeRequirement().isSubstitutionFailure())
4591	return HandleSubstitutionFailure(ER->getReturnTypeRequirement()
4592	.getSubstitutionDiagnostic()
4593	->DiagLoc);
4594
4595	Out << 'R';
4596	mangleTypeConstraint(Constraint: ER->getReturnTypeRequirement().getTypeConstraint());
4597	}
4598	break;
4599	}
4600
4601	case Requirement::RK_Nested:
4602	const auto *NR = cast<concepts::NestedRequirement>(Val: Req);
4603	if (NR->hasInvalidConstraint()) {
4604	// FIXME: NestedRequirement should track the location of its requires
4605	// keyword.
4606	return HandleSubstitutionFailure(RequiresExprLoc);
4607	}
4608
4609	Out << 'Q';
4610	mangleExpression(E: NR->getConstraintExpr());
4611	break;
4612	}
4613	}
4614
4615	void CXXNameMangler::mangleExpression(const Expr *E, unsigned Arity,
4616	bool AsTemplateArg) {
4617	// <expression> ::= <unary operator-name> <expression>
4618	// ::= <binary operator-name> <expression> <expression>
4619	// ::= <trinary operator-name> <expression> <expression> <expression>
4620	// ::= cv <type> expression # conversion with one argument
4621	// ::= cv <type> _ <expression>* E # conversion with a different number of arguments
4622	// ::= dc <type> <expression> # dynamic_cast<type> (expression)
4623	// ::= sc <type> <expression> # static_cast<type> (expression)
4624	// ::= cc <type> <expression> # const_cast<type> (expression)
4625	// ::= rc <type> <expression> # reinterpret_cast<type> (expression)
4626	// ::= st <type> # sizeof (a type)
4627	// ::= at <type> # alignof (a type)
4628	// ::= <template-param>
4629	// ::= <function-param>
4630	// ::= fpT # 'this' expression (part of <function-param>)
4631	// ::= sr <type> <unqualified-name> # dependent name
4632	// ::= sr <type> <unqualified-name> <template-args> # dependent template-id
4633	// ::= ds <expression> <expression> # expr.*expr
4634	// ::= sZ <template-param> # size of a parameter pack
4635	// ::= sZ <function-param> # size of a function parameter pack
4636	// ::= u <source-name> <template-arg>* E # vendor extended expression
4637	// ::= <expr-primary>
4638	// <expr-primary> ::= L <type> <value number> E # integer literal
4639	// ::= L <type> <value float> E # floating literal
4640	// ::= L <type> <string type> E # string literal
4641	// ::= L <nullptr type> E # nullptr literal "LDnE"
4642	// ::= L <pointer type> 0 E # null pointer template argument
4643	// ::= L <type> <real-part float> _ <imag-part float> E # complex floating point literal (C99); not used by clang
4644	// ::= L <mangled-name> E # external name
4645	QualType ImplicitlyConvertedToType;
4646
4647	// A top-level expression that's not <expr-primary> needs to be wrapped in
4648	// X...E in a template arg.
4649	bool IsPrimaryExpr = true;
4650	auto NotPrimaryExpr = [&] {
4651	if (AsTemplateArg && IsPrimaryExpr)
4652	Out << 'X';
4653	IsPrimaryExpr = false;
4654	};
4655
4656	auto MangleDeclRefExpr = [&](const NamedDecl *D) {
4657	switch (D->getKind()) {
4658	default:
4659	// <expr-primary> ::= L <mangled-name> E # external name
4660	Out << 'L';
4661	mangle(GD: D);
4662	Out << 'E';
4663	break;
4664
4665	case Decl::ParmVar:
4666	NotPrimaryExpr();
4667	mangleFunctionParam(parm: cast<ParmVarDecl>(Val: D));
4668	break;
4669
4670	case Decl::EnumConstant: {
4671	// <expr-primary>
4672	const EnumConstantDecl *ED = cast<EnumConstantDecl>(Val: D);
4673	mangleIntegerLiteral(T: ED->getType(), Value: ED->getInitVal());
4674	break;
4675	}
4676
4677	case Decl::NonTypeTemplateParm:
4678	NotPrimaryExpr();
4679	const NonTypeTemplateParmDecl *PD = cast<NonTypeTemplateParmDecl>(Val: D);
4680	mangleTemplateParameter(Depth: PD->getDepth(), Index: PD->getIndex());
4681	break;
4682	}
4683	};
4684
4685	// 'goto recurse' is used when handling a simple "unwrapping" node which
4686	// produces no output, where ImplicitlyConvertedToType and AsTemplateArg need
4687	// to be preserved.
4688	recurse:
4689	switch (E->getStmtClass()) {
4690	case Expr::NoStmtClass:
4691	#define ABSTRACT_STMT(Type)
4692	#define EXPR(Type, Base)
4693	#define STMT(Type, Base) \
4694	case Expr::Type##Class:
4695	#include "clang/AST/StmtNodes.inc"
4696	// fallthrough
4697
4698	// These all can only appear in local or variable-initialization
4699	// contexts and so should never appear in a mangling.
4700	case Expr::AddrLabelExprClass:
4701	case Expr::DesignatedInitUpdateExprClass:
4702	case Expr::ImplicitValueInitExprClass:
4703	case Expr::ArrayInitLoopExprClass:
4704	case Expr::ArrayInitIndexExprClass:
4705	case Expr::NoInitExprClass:
4706	case Expr::ParenListExprClass:
4707	case Expr::MSPropertyRefExprClass:
4708	case Expr::MSPropertySubscriptExprClass:
4709	case Expr::TypoExprClass: // This should no longer exist in the AST by now.
4710	case Expr::RecoveryExprClass:
4711	case Expr::OMPArraySectionExprClass:
4712	case Expr::OMPArrayShapingExprClass:
4713	case Expr::OMPIteratorExprClass:
4714	case Expr::CXXInheritedCtorInitExprClass:
4715	case Expr::CXXParenListInitExprClass:
4716	case Expr::PackIndexingExprClass:
4717	llvm_unreachable("unexpected statement kind");
4718
4719	case Expr::ConstantExprClass:
4720	E = cast<ConstantExpr>(E)->getSubExpr();
4721	goto recurse;
4722
4723	// FIXME: invent manglings for all these.
4724	case Expr::BlockExprClass:
4725	case Expr::ChooseExprClass:
4726	case Expr::CompoundLiteralExprClass:
4727	case Expr::ExtVectorElementExprClass:
4728	case Expr::GenericSelectionExprClass:
4729	case Expr::ObjCEncodeExprClass:
4730	case Expr::ObjCIsaExprClass:
4731	case Expr::ObjCIvarRefExprClass:
4732	case Expr::ObjCMessageExprClass:
4733	case Expr::ObjCPropertyRefExprClass:
4734	case Expr::ObjCProtocolExprClass:
4735	case Expr::ObjCSelectorExprClass:
4736	case Expr::ObjCStringLiteralClass:
4737	case Expr::ObjCBoxedExprClass:
4738	case Expr::ObjCArrayLiteralClass:
4739	case Expr::ObjCDictionaryLiteralClass:
4740	case Expr::ObjCSubscriptRefExprClass:
4741	case Expr::ObjCIndirectCopyRestoreExprClass:
4742	case Expr::ObjCAvailabilityCheckExprClass:
4743	case Expr::OffsetOfExprClass:
4744	case Expr::PredefinedExprClass:
4745	case Expr::ShuffleVectorExprClass:
4746	case Expr::ConvertVectorExprClass:
4747	case Expr::StmtExprClass:
4748	case Expr::ArrayTypeTraitExprClass:
4749	case Expr::ExpressionTraitExprClass:
4750	case Expr::VAArgExprClass:
4751	case Expr::CUDAKernelCallExprClass:
4752	case Expr::AsTypeExprClass:
4753	case Expr::PseudoObjectExprClass:
4754	case Expr::AtomicExprClass:
4755	case Expr::SourceLocExprClass:
4756	case Expr::BuiltinBitCastExprClass:
4757	{
4758	NotPrimaryExpr();
4759	if (!NullOut) {
4760	// As bad as this diagnostic is, it's better than crashing.
4761	DiagnosticsEngine &Diags = Context.getDiags();
4762	unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
4763	"cannot yet mangle expression type %0");
4764	Diags.Report(Loc: E->getExprLoc(), DiagID)
4765	<< E->getStmtClassName() << E->getSourceRange();
4766	return;
4767	}
4768	break;
4769	}
4770
4771	case Expr::CXXUuidofExprClass: {
4772	NotPrimaryExpr();
4773	const CXXUuidofExpr *UE = cast<CXXUuidofExpr>(E);
4774	// As of clang 12, uuidof uses the vendor extended expression
4775	// mangling. Previously, it used a special-cased nonstandard extension.
4776	if (!isCompatibleWith(Ver: LangOptions::ClangABI::Ver11)) {
4777	Out << "u8__uuidof";
4778	if (UE->isTypeOperand())
4779	mangleType(T: UE->getTypeOperand(Context&: Context.getASTContext()));
4780	else
4781	mangleTemplateArgExpr(E: UE->getExprOperand());
4782	Out << 'E';
4783	} else {
4784	if (UE->isTypeOperand()) {
4785	QualType UuidT = UE->getTypeOperand(Context&: Context.getASTContext());
4786	Out << "u8__uuidoft";
4787	mangleType(T: UuidT);
4788	} else {
4789	Expr *UuidExp = UE->getExprOperand();
4790	Out << "u8__uuidofz";
4791	mangleExpression(E: UuidExp);
4792	}
4793	}
4794	break;
4795	}
4796
4797	// Even gcc-4.5 doesn't mangle this.
4798	case Expr::BinaryConditionalOperatorClass: {
4799	NotPrimaryExpr();
4800	DiagnosticsEngine &Diags = Context.getDiags();
4801	unsigned DiagID =
4802	Diags.getCustomDiagID(DiagnosticsEngine::Error,
4803	"?: operator with omitted middle operand cannot be mangled");
4804	Diags.Report(Loc: E->getExprLoc(), DiagID)
4805	<< E->getStmtClassName() << E->getSourceRange();
4806	return;
4807	}
4808
4809	// These are used for internal purposes and cannot be meaningfully mangled.
4810	case Expr::OpaqueValueExprClass:
4811	llvm_unreachable("cannot mangle opaque value; mangling wrong thing?");
4812
4813	case Expr::InitListExprClass: {
4814	NotPrimaryExpr();
4815	Out << "il";
4816	mangleInitListElements(InitList: cast<InitListExpr>(E));
4817	Out << "E";
4818	break;
4819	}
4820
4821	case Expr::DesignatedInitExprClass: {
4822	NotPrimaryExpr();
4823	auto *DIE = cast<DesignatedInitExpr>(E);
4824	for (const auto &Designator : DIE->designators()) {
4825	if (Designator.isFieldDesignator()) {
4826	Out << "di";
4827	mangleSourceName(Designator.getFieldName());
4828	} else if (Designator.isArrayDesignator()) {
4829	Out << "dx";
4830	mangleExpression(DIE->getArrayIndex(Designator));
4831	} else {
4832	assert(Designator.isArrayRangeDesignator() &&
4833	"unknown designator kind");
4834	Out << "dX";
4835	mangleExpression(DIE->getArrayRangeStart(Designator));
4836	mangleExpression(DIE->getArrayRangeEnd(Designator));
4837	}
4838	}
4839	mangleExpression(E: DIE->getInit());
4840	break;
4841	}
4842
4843	case Expr::CXXDefaultArgExprClass:
4844	E = cast<CXXDefaultArgExpr>(E)->getExpr();
4845	goto recurse;
4846
4847	case Expr::CXXDefaultInitExprClass:
4848	E = cast<CXXDefaultInitExpr>(E)->getExpr();
4849	goto recurse;
4850
4851	case Expr::CXXStdInitializerListExprClass:
4852	E = cast<CXXStdInitializerListExpr>(E)->getSubExpr();
4853	goto recurse;
4854
4855	case Expr::SubstNonTypeTemplateParmExprClass: {
4856	// Mangle a substituted parameter the same way we mangle the template
4857	// argument.
4858	auto *SNTTPE = cast<SubstNonTypeTemplateParmExpr>(E);
4859	if (auto *CE = dyn_cast<ConstantExpr>(SNTTPE->getReplacement())) {
4860	// Pull out the constant value and mangle it as a template argument.
4861	QualType ParamType = SNTTPE->getParameterType(Context.getASTContext());
4862	assert(CE->hasAPValueResult() && "expected the NTTP to have an APValue");
4863	mangleValueInTemplateArg(T: ParamType, V: CE->getAPValueResult(), TopLevel: false,
4864	/*NeedExactType=*/true);
4865	break;
4866	}
4867	// The remaining cases all happen to be substituted with expressions that
4868	// mangle the same as a corresponding template argument anyway.
4869	E = cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement();
4870	goto recurse;
4871	}
4872
4873	case Expr::UserDefinedLiteralClass:
4874	// We follow g++'s approach of mangling a UDL as a call to the literal
4875	// operator.
4876	case Expr::CXXMemberCallExprClass: // fallthrough
4877	case Expr::CallExprClass: {
4878	NotPrimaryExpr();
4879	const CallExpr *CE = cast<CallExpr>(E);
4880
4881	// <expression> ::= cp <simple-id> <expression>* E
4882	// We use this mangling only when the call would use ADL except
4883	// for being parenthesized. Per discussion with David
4884	// Vandervoorde, 2011.04.25.
4885	if (isParenthesizedADLCallee(call: CE)) {
4886	Out << "cp";
4887	// The callee here is a parenthesized UnresolvedLookupExpr with
4888	// no qualifier and should always get mangled as a <simple-id>
4889	// anyway.
4890
4891	// <expression> ::= cl <expression>* E
4892	} else {
4893	Out << "cl";
4894	}
4895
4896	unsigned CallArity = CE->getNumArgs();
4897	for (const Expr *Arg : CE->arguments())
4898	if (isa<PackExpansionExpr>(Arg))
4899	CallArity = UnknownArity;
4900
4901	mangleExpression(E: CE->getCallee(), Arity: CallArity);
4902	for (const Expr *Arg : CE->arguments())
4903	mangleExpression(Arg);
4904	Out << 'E';
4905	break;
4906	}
4907
4908	case Expr::CXXNewExprClass: {
4909	NotPrimaryExpr();
4910	const CXXNewExpr *New = cast<CXXNewExpr>(E);
4911	if (New->isGlobalNew()) Out << "gs";
4912	Out << (New->isArray() ? "na" : "nw");
4913	for (CXXNewExpr::const_arg_iterator I = New->placement_arg_begin(),
4914	E = New->placement_arg_end(); I != E; ++I)
4915	mangleExpression(*I);
4916	Out << '_';
4917	mangleType(T: New->getAllocatedType());
4918	if (New->hasInitializer()) {
4919	if (New->getInitializationStyle() == CXXNewInitializationStyle::Braces)
4920	Out << "il";
4921	else
4922	Out << "pi";
4923	const Expr *Init = New->getInitializer();
4924	if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) {
4925	// Directly inline the initializers.
4926	for (CXXConstructExpr::const_arg_iterator I = CCE->arg_begin(),
4927	E = CCE->arg_end();
4928	I != E; ++I)
4929	mangleExpression(*I);
4930	} else if (const ParenListExpr *PLE = dyn_cast<ParenListExpr>(Init)) {
4931	for (unsigned i = 0, e = PLE->getNumExprs(); i != e; ++i)
4932	mangleExpression(E: PLE->getExpr(Init: i));
4933	} else if (New->getInitializationStyle() ==
4934	CXXNewInitializationStyle::Braces &&
4935	isa<InitListExpr>(Init)) {
4936	// Only take InitListExprs apart for list-initialization.
4937	mangleInitListElements(InitList: cast<InitListExpr>(Init));
4938	} else
4939	mangleExpression(E: Init);
4940	}
4941	Out << 'E';
4942	break;
4943	}
4944
4945	case Expr::CXXPseudoDestructorExprClass: {
4946	NotPrimaryExpr();
4947	const auto *PDE = cast<CXXPseudoDestructorExpr>(E);
4948	if (const Expr *Base = PDE->getBase())
4949	mangleMemberExprBase(Base, IsArrow: PDE->isArrow());
4950	NestedNameSpecifier *Qualifier = PDE->getQualifier();
4951	if (TypeSourceInfo *ScopeInfo = PDE->getScopeTypeInfo()) {
4952	if (Qualifier) {
4953	mangleUnresolvedPrefix(qualifier: Qualifier,
4954	/*recursive=*/true);
4955	mangleUnresolvedTypeOrSimpleId(Ty: ScopeInfo->getType());
4956	Out << 'E';
4957	} else {
4958	Out << "sr";
4959	if (!mangleUnresolvedTypeOrSimpleId(Ty: ScopeInfo->getType()))
4960	Out << 'E';
4961	}
4962	} else if (Qualifier) {
4963	mangleUnresolvedPrefix(qualifier: Qualifier);
4964	}
4965	// <base-unresolved-name> ::= dn <destructor-name>
4966	Out << "dn";
4967	QualType DestroyedType = PDE->getDestroyedType();
4968	mangleUnresolvedTypeOrSimpleId(Ty: DestroyedType);
4969	break;
4970	}
4971
4972	case Expr::MemberExprClass: {
4973	NotPrimaryExpr();
4974	const MemberExpr *ME = cast<MemberExpr>(E);
4975	mangleMemberExpr(base: ME->getBase(), isArrow: ME->isArrow(),
4976	qualifier: ME->getQualifier(), firstQualifierLookup: nullptr,
4977	member: ME->getMemberDecl()->getDeclName(),
4978	TemplateArgs: ME->getTemplateArgs(), NumTemplateArgs: ME->getNumTemplateArgs(),
4979	arity: Arity);
4980	break;
4981	}
4982
4983	case Expr::UnresolvedMemberExprClass: {
4984	NotPrimaryExpr();
4985	const UnresolvedMemberExpr *ME = cast<UnresolvedMemberExpr>(E);
4986	mangleMemberExpr(base: ME->isImplicitAccess() ? nullptr : ME->getBase(),
4987	isArrow: ME->isArrow(), qualifier: ME->getQualifier(), firstQualifierLookup: nullptr,
4988	member: ME->getMemberName(),
4989	TemplateArgs: ME->getTemplateArgs(), NumTemplateArgs: ME->getNumTemplateArgs(),
4990	arity: Arity);
4991	break;
4992	}
4993
4994	case Expr::CXXDependentScopeMemberExprClass: {
4995	NotPrimaryExpr();
4996	const CXXDependentScopeMemberExpr *ME
4997	= cast<CXXDependentScopeMemberExpr>(E);
4998	mangleMemberExpr(base: ME->isImplicitAccess() ? nullptr : ME->getBase(),
4999	isArrow: ME->isArrow(), qualifier: ME->getQualifier(),
5000	firstQualifierLookup: ME->getFirstQualifierFoundInScope(),
5001	member: ME->getMember(),
5002	TemplateArgs: ME->getTemplateArgs(), NumTemplateArgs: ME->getNumTemplateArgs(),
5003	arity: Arity);
5004	break;
5005	}
5006
5007	case Expr::UnresolvedLookupExprClass: {
5008	NotPrimaryExpr();
5009	const UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(E);
5010	mangleUnresolvedName(qualifier: ULE->getQualifier(), name: ULE->getName(),
5011	TemplateArgs: ULE->getTemplateArgs(), NumTemplateArgs: ULE->getNumTemplateArgs(),
5012	knownArity: Arity);
5013	break;
5014	}
5015
5016	case Expr::CXXUnresolvedConstructExprClass: {
5017	NotPrimaryExpr();
5018	const CXXUnresolvedConstructExpr *CE = cast<CXXUnresolvedConstructExpr>(E);
5019	unsigned N = CE->getNumArgs();
5020
5021	if (CE->isListInitialization()) {
5022	assert(N == 1 && "unexpected form for list initialization");
5023	auto *IL = cast<InitListExpr>(CE->getArg(I: 0));
5024	Out << "tl";
5025	mangleType(CE->getType());
5026	mangleInitListElements(InitList: IL);
5027	Out << "E";
5028	break;
5029	}
5030
5031	Out << "cv";
5032	mangleType(CE->getType());
5033	if (N != 1) Out << '_';
5034	for (unsigned I = 0; I != N; ++I) mangleExpression(E: CE->getArg(I));
5035	if (N != 1) Out << 'E';
5036	break;
5037	}
5038
5039	case Expr::CXXConstructExprClass: {
5040	// An implicit cast is silent, thus may contain <expr-primary>.
5041	const auto *CE = cast<CXXConstructExpr>(E);
5042	if (!CE->isListInitialization() || CE->isStdInitListInitialization()) {
5043	assert(
5044	CE->getNumArgs() >= 1 &&
5045	(CE->getNumArgs() == 1 || isa<CXXDefaultArgExpr>(CE->getArg(1))) &&
5046	"implicit CXXConstructExpr must have one argument");
5047	E = cast<CXXConstructExpr>(E)->getArg(0);
5048	goto recurse;
5049	}
5050	NotPrimaryExpr();
5051	Out << "il";
5052	for (auto *E : CE->arguments())
5053	mangleExpression(E);
5054	Out << "E";
5055	break;
5056	}
5057
5058	case Expr::CXXTemporaryObjectExprClass: {
5059	NotPrimaryExpr();
5060	const auto *CE = cast<CXXTemporaryObjectExpr>(E);
5061	unsigned N = CE->getNumArgs();
5062	bool List = CE->isListInitialization();
5063
5064	if (List)
5065	Out << "tl";
5066	else
5067	Out << "cv";
5068	mangleType(CE->getType());
5069	if (!List && N != 1)
5070	Out << '_';
5071	if (CE->isStdInitListInitialization()) {
5072	// We implicitly created a std::initializer_list<T> for the first argument
5073	// of a constructor of type U in an expression of the form U{a, b, c}.
5074	// Strip all the semantic gunk off the initializer list.
5075	auto *SILE =
5076	cast<CXXStdInitializerListExpr>(CE->getArg(0)->IgnoreImplicit());
5077	auto *ILE = cast<InitListExpr>(SILE->getSubExpr()->IgnoreImplicit());
5078	mangleInitListElements(InitList: ILE);
5079	} else {
5080	for (auto *E : CE->arguments())
5081	mangleExpression(E);
5082	}
5083	if (List || N != 1)
5084	Out << 'E';
5085	break;
5086	}
5087
5088	case Expr::CXXScalarValueInitExprClass:
5089	NotPrimaryExpr();
5090	Out << "cv";
5091	mangleType(T: E->getType());
5092	Out << "_E";
5093	break;
5094
5095	case Expr::CXXNoexceptExprClass:
5096	NotPrimaryExpr();
5097	Out << "nx";
5098	mangleExpression(E: cast<CXXNoexceptExpr>(E)->getOperand());
5099	break;
5100
5101	case Expr::UnaryExprOrTypeTraitExprClass: {
5102	// Non-instantiation-dependent traits are an <expr-primary> integer literal.
5103	const UnaryExprOrTypeTraitExpr *SAE = cast<UnaryExprOrTypeTraitExpr>(E);
5104
5105	if (!SAE->isInstantiationDependent()) {
5106	// Itanium C++ ABI:
5107	// If the operand of a sizeof or alignof operator is not
5108	// instantiation-dependent it is encoded as an integer literal
5109	// reflecting the result of the operator.
5110	//
5111	// If the result of the operator is implicitly converted to a known
5112	// integer type, that type is used for the literal; otherwise, the type
5113	// of std::size_t or std::ptrdiff_t is used.
5114	//
5115	// FIXME: We still include the operand in the profile in this case. This
5116	// can lead to mangling collisions between function templates that we
5117	// consider to be different.
5118	QualType T = (ImplicitlyConvertedToType.isNull() ||
5119	!ImplicitlyConvertedToType->isIntegerType())? SAE->getType()
5120	: ImplicitlyConvertedToType;
5121	llvm::APSInt V = SAE->EvaluateKnownConstInt(Context.getASTContext());
5122	mangleIntegerLiteral(T, Value: V);
5123	break;
5124	}
5125
5126	NotPrimaryExpr(); // But otherwise, they are not.
5127
5128	auto MangleAlignofSizeofArg = [&] {
5129	if (SAE->isArgumentType()) {
5130	Out << 't';
5131	mangleType(T: SAE->getArgumentType());
5132	} else {
5133	Out << 'z';
5134	mangleExpression(E: SAE->getArgumentExpr());
5135	}
5136	};
5137
5138	switch(SAE->getKind()) {
5139	case UETT_SizeOf:
5140	Out << 's';
5141	MangleAlignofSizeofArg();
5142	break;
5143	case UETT_PreferredAlignOf:
5144	// As of clang 12, we mangle __alignof__ differently than alignof. (They
5145	// have acted differently since Clang 8, but were previously mangled the
5146	// same.)
5147	if (!isCompatibleWith(Ver: LangOptions::ClangABI::Ver11)) {
5148	Out << "u11__alignof__";
5149	if (SAE->isArgumentType())
5150	mangleType(T: SAE->getArgumentType());
5151	else
5152	mangleTemplateArgExpr(E: SAE->getArgumentExpr());
5153	Out << 'E';
5154	break;
5155	}
5156	[[fallthrough]];
5157	case UETT_AlignOf:
5158	Out << 'a';
5159	MangleAlignofSizeofArg();
5160	break;
5161	case UETT_DataSizeOf: {
5162	DiagnosticsEngine &Diags = Context.getDiags();
5163	unsigned DiagID =
5164	Diags.getCustomDiagID(DiagnosticsEngine::Error,
5165	"cannot yet mangle __datasizeof expression");
5166	Diags.Report(DiagID);
5167	return;
5168	}
5169	case UETT_VecStep: {
5170	DiagnosticsEngine &Diags = Context.getDiags();
5171	unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
5172	"cannot yet mangle vec_step expression");
5173	Diags.Report(DiagID);
5174	return;
5175	}
5176	case UETT_OpenMPRequiredSimdAlign: {
5177	DiagnosticsEngine &Diags = Context.getDiags();
5178	unsigned DiagID = Diags.getCustomDiagID(
5179	DiagnosticsEngine::Error,
5180	"cannot yet mangle __builtin_omp_required_simd_align expression");
5181	Diags.Report(DiagID);
5182	return;
5183	}
5184	case UETT_VectorElements: {
5185	DiagnosticsEngine &Diags = Context.getDiags();
5186	unsigned DiagID = Diags.getCustomDiagID(
5187	DiagnosticsEngine::Error,
5188	"cannot yet mangle __builtin_vectorelements expression");
5189	Diags.Report(DiagID);
5190	return;
5191	}
5192	}
5193	break;
5194	}
5195
5196	case Expr::TypeTraitExprClass: {
5197	// <expression> ::= u <source-name> <template-arg>* E # vendor extension
5198	const TypeTraitExpr *TTE = cast<TypeTraitExpr>(E);
5199	NotPrimaryExpr();
5200	Out << 'u';
5201	llvm::StringRef Spelling = getTraitSpelling(T: TTE->getTrait());
5202	Out << Spelling.size() << Spelling;
5203	for (TypeSourceInfo *TSI : TTE->getArgs()) {
5204	mangleType(TSI->getType());
5205	}
5206	Out << 'E';
5207	break;
5208	}
5209
5210	case Expr::CXXThrowExprClass: {
5211	NotPrimaryExpr();
5212	const CXXThrowExpr *TE = cast<CXXThrowExpr>(E);
5213	// <expression> ::= tw <expression> # throw expression
5214	// ::= tr # rethrow
5215	if (TE->getSubExpr()) {
5216	Out << "tw";
5217	mangleExpression(E: TE->getSubExpr());
5218	} else {
5219	Out << "tr";
5220	}
5221	break;
5222	}
5223
5224	case Expr::CXXTypeidExprClass: {
5225	NotPrimaryExpr();
5226	const CXXTypeidExpr *TIE = cast<CXXTypeidExpr>(E);
5227	// <expression> ::= ti <type> # typeid (type)
5228	// ::= te <expression> # typeid (expression)
5229	if (TIE->isTypeOperand()) {
5230	Out << "ti";
5231	mangleType(T: TIE->getTypeOperand(Context&: Context.getASTContext()));
5232	} else {
5233	Out << "te";
5234	mangleExpression(E: TIE->getExprOperand());
5235	}
5236	break;
5237	}
5238
5239	case Expr::CXXDeleteExprClass: {
5240	NotPrimaryExpr();
5241	const CXXDeleteExpr *DE = cast<CXXDeleteExpr>(E);
5242	// <expression> ::= [gs] dl <expression> # [::] delete expr
5243	// ::= [gs] da <expression> # [::] delete [] expr
5244	if (DE->isGlobalDelete()) Out << "gs";
5245	Out << (DE->isArrayForm() ? "da" : "dl");
5246	mangleExpression(E: DE->getArgument());
5247	break;
5248	}
5249
5250	case Expr::UnaryOperatorClass: {
5251	NotPrimaryExpr();
5252	const UnaryOperator *UO = cast<UnaryOperator>(E);
5253	mangleOperatorName(OO: UnaryOperator::getOverloadedOperator(Opc: UO->getOpcode()),
5254	/*Arity=*/1);
5255	mangleExpression(E: UO->getSubExpr());
5256	break;
5257	}
5258
5259	case Expr::ArraySubscriptExprClass: {
5260	NotPrimaryExpr();
5261	const ArraySubscriptExpr *AE = cast<ArraySubscriptExpr>(E);
5262
5263	// Array subscript is treated as a syntactically weird form of
5264	// binary operator.
5265	Out << "ix";
5266	mangleExpression(E: AE->getLHS());
5267	mangleExpression(E: AE->getRHS());
5268	break;
5269	}
5270
5271	case Expr::MatrixSubscriptExprClass: {
5272	NotPrimaryExpr();
5273	const MatrixSubscriptExpr *ME = cast<MatrixSubscriptExpr>(E);
5274	Out << "ixix";
5275	mangleExpression(E: ME->getBase());
5276	mangleExpression(E: ME->getRowIdx());
5277	mangleExpression(E: ME->getColumnIdx());
5278	break;
5279	}
5280
5281	case Expr::CompoundAssignOperatorClass: // fallthrough
5282	case Expr::BinaryOperatorClass: {
5283	NotPrimaryExpr();
5284	const BinaryOperator *BO = cast<BinaryOperator>(E);
5285	if (BO->getOpcode() == BO_PtrMemD)
5286	Out << "ds";
5287	else
5288	mangleOperatorName(OO: BinaryOperator::getOverloadedOperator(Opc: BO->getOpcode()),
5289	/*Arity=*/2);
5290	mangleExpression(E: BO->getLHS());
5291	mangleExpression(E: BO->getRHS());
5292	break;
5293	}
5294
5295	case Expr::CXXRewrittenBinaryOperatorClass: {
5296	NotPrimaryExpr();
5297	// The mangled form represents the original syntax.
5298	CXXRewrittenBinaryOperator::DecomposedForm Decomposed =
5299	cast<CXXRewrittenBinaryOperator>(E)->getDecomposedForm();
5300	mangleOperatorName(OO: BinaryOperator::getOverloadedOperator(Opc: Decomposed.Opcode),
5301	/*Arity=*/2);
5302	mangleExpression(E: Decomposed.LHS);
5303	mangleExpression(E: Decomposed.RHS);
5304	break;
5305	}
5306
5307	case Expr::ConditionalOperatorClass: {
5308	NotPrimaryExpr();
5309	const ConditionalOperator *CO = cast<ConditionalOperator>(E);
5310	mangleOperatorName(OO: OO_Conditional, /*Arity=*/3);
5311	mangleExpression(E: CO->getCond());
5312	mangleExpression(E: CO->getLHS(), Arity);
5313	mangleExpression(E: CO->getRHS(), Arity);
5314	break;
5315	}
5316
5317	case Expr::ImplicitCastExprClass: {
5318	ImplicitlyConvertedToType = E->getType();
5319	E = cast<ImplicitCastExpr>(E)->getSubExpr();
5320	goto recurse;
5321	}
5322
5323	case Expr::ObjCBridgedCastExprClass: {
5324	NotPrimaryExpr();
5325	// Mangle ownership casts as a vendor extended operator __bridge,
5326	// __bridge_transfer, or __bridge_retain.
5327	StringRef Kind = cast<ObjCBridgedCastExpr>(E)->getBridgeKindName();
5328	Out << "v1U" << Kind.size() << Kind;
5329	mangleCastExpression(E, CastEncoding: "cv");
5330	break;
5331	}
5332
5333	case Expr::CStyleCastExprClass:
5334	NotPrimaryExpr();
5335	mangleCastExpression(E, CastEncoding: "cv");
5336	break;
5337
5338	case Expr::CXXFunctionalCastExprClass: {
5339	NotPrimaryExpr();
5340	auto *Sub = cast<ExplicitCastExpr>(E)->getSubExpr()->IgnoreImplicit();
5341	// FIXME: Add isImplicit to CXXConstructExpr.
5342	if (auto *CCE = dyn_cast<CXXConstructExpr>(Sub))
5343	if (CCE->getParenOrBraceRange().isInvalid())
5344	Sub = CCE->getArg(0)->IgnoreImplicit();
5345	if (auto *StdInitList = dyn_cast<CXXStdInitializerListExpr>(Sub))
5346	Sub = StdInitList->getSubExpr()->IgnoreImplicit();
5347	if (auto *IL = dyn_cast<InitListExpr>(Sub)) {
5348	Out << "tl";
5349	mangleType(T: E->getType());
5350	mangleInitListElements(InitList: IL);
5351	Out << "E";
5352	} else {
5353	mangleCastExpression(E, CastEncoding: "cv");
5354	}
5355	break;
5356	}
5357
5358	case Expr::CXXStaticCastExprClass:
5359	NotPrimaryExpr();
5360	mangleCastExpression(E, CastEncoding: "sc");
5361	break;
5362	case Expr::CXXDynamicCastExprClass:
5363	NotPrimaryExpr();
5364	mangleCastExpression(E, CastEncoding: "dc");
5365	break;
5366	case Expr::CXXReinterpretCastExprClass:
5367	NotPrimaryExpr();
5368	mangleCastExpression(E, CastEncoding: "rc");
5369	break;
5370	case Expr::CXXConstCastExprClass:
5371	NotPrimaryExpr();
5372	mangleCastExpression(E, CastEncoding: "cc");
5373	break;
5374	case Expr::CXXAddrspaceCastExprClass:
5375	NotPrimaryExpr();
5376	mangleCastExpression(E, CastEncoding: "ac");
5377	break;
5378
5379	case Expr::CXXOperatorCallExprClass: {
5380	NotPrimaryExpr();
5381	const CXXOperatorCallExpr *CE = cast<CXXOperatorCallExpr>(E);
5382	unsigned NumArgs = CE->getNumArgs();
5383	// A CXXOperatorCallExpr for OO_Arrow models only semantics, not syntax
5384	// (the enclosing MemberExpr covers the syntactic portion).
5385	if (CE->getOperator() != OO_Arrow)
5386	mangleOperatorName(OO: CE->getOperator(), /*Arity=*/NumArgs);
5387	// Mangle the arguments.
5388	for (unsigned i = 0; i != NumArgs; ++i)
5389	mangleExpression(E: CE->getArg(i));
5390	break;
5391	}
5392
5393	case Expr::ParenExprClass:
5394	E = cast<ParenExpr>(E)->getSubExpr();
5395	goto recurse;
5396
5397	case Expr::ConceptSpecializationExprClass: {
5398	auto *CSE = cast<ConceptSpecializationExpr>(E);
5399	if (isCompatibleWith(Ver: LangOptions::ClangABI::Ver17)) {
5400	// Clang 17 and before mangled concept-ids as if they resolved to an
5401	// entity, meaning that references to enclosing template arguments don't
5402	// work.
5403	Out << "L_Z";
5404	mangleTemplateName(TD: CSE->getNamedConcept(), Args: CSE->getTemplateArguments());
5405	Out << 'E';
5406	break;
5407	}
5408	// Proposed on https://github.com/itanium-cxx-abi/cxx-abi/issues/24.
5409	NotPrimaryExpr();
5410	mangleUnresolvedName(
5411	qualifier: CSE->getNestedNameSpecifierLoc().getNestedNameSpecifier(),
5412	name: CSE->getConceptNameInfo().getName(),
5413	TemplateArgs: CSE->getTemplateArgsAsWritten()->getTemplateArgs(),
5414	NumTemplateArgs: CSE->getTemplateArgsAsWritten()->getNumTemplateArgs());
5415	break;
5416	}
5417
5418	case Expr::RequiresExprClass: {
5419	// Proposed on https://github.com/itanium-cxx-abi/cxx-abi/issues/24.
5420	auto *RE = cast<RequiresExpr>(E);
5421	// This is a primary-expression in the C++ grammar, but does not have an
5422	// <expr-primary> mangling (starting with 'L').
5423	NotPrimaryExpr();
5424	if (RE->getLParenLoc().isValid()) {
5425	Out << "rQ";
5426	FunctionTypeDepthState saved = FunctionTypeDepth.push();
5427	if (RE->getLocalParameters().empty()) {
5428	Out << 'v';
5429	} else {
5430	for (ParmVarDecl *Param : RE->getLocalParameters()) {
5431	mangleType(Context.getASTContext().getSignatureParameterType(
5432	Param->getType()));
5433	}
5434	}
5435	Out << '_';
5436
5437	// The rest of the mangling is in the immediate scope of the parameters.
5438	FunctionTypeDepth.enterResultType();
5439	for (const concepts::Requirement *Req : RE->getRequirements())
5440	mangleRequirement(RE->getExprLoc(), Req);
5441	FunctionTypeDepth.pop(saved);
5442	Out << 'E';
5443	} else {
5444	Out << "rq";
5445	for (const concepts::Requirement *Req : RE->getRequirements())
5446	mangleRequirement(RE->getExprLoc(), Req);
5447	Out << 'E';
5448	}
5449	break;
5450	}
5451
5452	case Expr::DeclRefExprClass:
5453	// MangleDeclRefExpr helper handles primary-vs-nonprimary
5454	MangleDeclRefExpr(cast<DeclRefExpr>(E)->getDecl());
5455	break;
5456
5457	case Expr::SubstNonTypeTemplateParmPackExprClass:
5458	NotPrimaryExpr();
5459	// FIXME: not clear how to mangle this!
5460	// template <unsigned N...> class A {
5461	// template <class U...> void foo(U (&x)[N]...);
5462	// };
5463	Out << "_SUBSTPACK_";
5464	break;
5465
5466	case Expr::FunctionParmPackExprClass: {
5467	NotPrimaryExpr();
5468	// FIXME: not clear how to mangle this!
5469	const FunctionParmPackExpr *FPPE = cast<FunctionParmPackExpr>(E);
5470	Out << "v110_SUBSTPACK";
5471	MangleDeclRefExpr(FPPE->getParameterPack());
5472	break;
5473	}
5474
5475	case Expr::DependentScopeDeclRefExprClass: {
5476	NotPrimaryExpr();
5477	const DependentScopeDeclRefExpr *DRE = cast<DependentScopeDeclRefExpr>(E);
5478	mangleUnresolvedName(qualifier: DRE->getQualifier(), name: DRE->getDeclName(),
5479	TemplateArgs: DRE->getTemplateArgs(), NumTemplateArgs: DRE->getNumTemplateArgs(),
5480	knownArity: Arity);
5481	break;
5482	}
5483
5484	case Expr::CXXBindTemporaryExprClass:
5485	E = cast<CXXBindTemporaryExpr>(E)->getSubExpr();
5486	goto recurse;
5487
5488	case Expr::ExprWithCleanupsClass:
5489	E = cast<ExprWithCleanups>(E)->getSubExpr();
5490	goto recurse;
5491
5492	case Expr::FloatingLiteralClass: {
5493	// <expr-primary>
5494	const FloatingLiteral *FL = cast<FloatingLiteral>(E);
5495	mangleFloatLiteral(T: FL->getType(), V: FL->getValue());
5496	break;
5497	}
5498
5499	case Expr::FixedPointLiteralClass:
5500	// Currently unimplemented -- might be <expr-primary> in future?
5501	mangleFixedPointLiteral();
5502	break;
5503
5504	case Expr::CharacterLiteralClass:
5505	// <expr-primary>
5506	Out << 'L';
5507	mangleType(T: E->getType());
5508	Out << cast<CharacterLiteral>(E)->getValue();
5509	Out << 'E';
5510	break;
5511
5512	// FIXME. __objc_yes/__objc_no are mangled same as true/false
5513	case Expr::ObjCBoolLiteralExprClass:
5514	// <expr-primary>
5515	Out << "Lb";
5516	Out << (cast<ObjCBoolLiteralExpr>(E)->getValue() ? '1' : '0');
5517	Out << 'E';
5518	break;
5519
5520	case Expr::CXXBoolLiteralExprClass:
5521	// <expr-primary>
5522	Out << "Lb";
5523	Out << (cast<CXXBoolLiteralExpr>(E)->getValue() ? '1' : '0');
5524	Out << 'E';
5525	break;
5526
5527	case Expr::IntegerLiteralClass: {
5528	// <expr-primary>
5529	llvm::APSInt Value(cast<IntegerLiteral>(E)->getValue());
5530	if (E->getType()->isSignedIntegerType())
5531	Value.setIsSigned(true);
5532	mangleIntegerLiteral(T: E->getType(), Value);
5533	break;
5534	}
5535
5536	case Expr::ImaginaryLiteralClass: {
5537	// <expr-primary>
5538	const ImaginaryLiteral *IE = cast<ImaginaryLiteral>(E);
5539	// Mangle as if a complex literal.
5540	// Proposal from David Vandevoorde, 2010.06.30.
5541	Out << 'L';
5542	mangleType(T: E->getType());
5543	if (const FloatingLiteral *Imag =
5544	dyn_cast<FloatingLiteral>(IE->getSubExpr())) {
5545	// Mangle a floating-point zero of the appropriate type.
5546	mangleFloat(f: llvm::APFloat(Imag->getValue().getSemantics()));
5547	Out << '_';
5548	mangleFloat(f: Imag->getValue());
5549	} else {
5550	Out << "0_";
5551	llvm::APSInt Value(cast<IntegerLiteral>(IE->getSubExpr())->getValue());
5552	if (IE->getSubExpr()->getType()->isSignedIntegerType())
5553	Value.setIsSigned(true);
5554	mangleNumber(Value);
5555	}
5556	Out << 'E';
5557	break;
5558	}
5559
5560	case Expr::StringLiteralClass: {
5561	// <expr-primary>
5562	// Revised proposal from David Vandervoorde, 2010.07.15.
5563	Out << 'L';
5564	assert(isa<ConstantArrayType>(E->getType()));
5565	mangleType(T: E->getType());
5566	Out << 'E';
5567	break;
5568	}
5569
5570	case Expr::GNUNullExprClass:
5571	// <expr-primary>
5572	// Mangle as if an integer literal 0.
5573	mangleIntegerLiteral(T: E->getType(), Value: llvm::APSInt(32));
5574	break;
5575
5576	case Expr::CXXNullPtrLiteralExprClass: {
5577	// <expr-primary>
5578	Out << "LDnE";
5579	break;
5580	}
5581
5582	case Expr::LambdaExprClass: {
5583	// A lambda-expression can't appear in the signature of an
5584	// externally-visible declaration, so there's no standard mangling for
5585	// this, but mangling as a literal of the closure type seems reasonable.
5586	Out << "L";
5587	mangleType(Context.getASTContext().getRecordType(Decl: cast<LambdaExpr>(E)->getLambdaClass()));
5588	Out << "E";
5589	break;
5590	}
5591
5592	case Expr::PackExpansionExprClass:
5593	NotPrimaryExpr();
5594	Out << "sp";
5595	mangleExpression(E: cast<PackExpansionExpr>(E)->getPattern());
5596	break;
5597
5598	case Expr::SizeOfPackExprClass: {
5599	NotPrimaryExpr();
5600	auto *SPE = cast<SizeOfPackExpr>(E);
5601	if (SPE->isPartiallySubstituted()) {
5602	Out << "sP";
5603	for (const auto &A : SPE->getPartialArguments())
5604	mangleTemplateArg(A, false);
5605	Out << "E";
5606	break;
5607	}
5608
5609	Out << "sZ";
5610	const NamedDecl *Pack = SPE->getPack();
5611	if (const TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Pack))
5612	mangleTemplateParameter(Depth: TTP->getDepth(), Index: TTP->getIndex());
5613	else if (const NonTypeTemplateParmDecl *NTTP
5614	= dyn_cast<NonTypeTemplateParmDecl>(Pack))
5615	mangleTemplateParameter(Depth: NTTP->getDepth(), Index: NTTP->getIndex());
5616	else if (const TemplateTemplateParmDecl *TempTP
5617	= dyn_cast<TemplateTemplateParmDecl>(Pack))
5618	mangleTemplateParameter(Depth: TempTP->getDepth(), Index: TempTP->getIndex());
5619	else
5620	mangleFunctionParam(parm: cast<ParmVarDecl>(Pack));
5621	break;
5622	}
5623
5624	case Expr::MaterializeTemporaryExprClass:
5625	E = cast<MaterializeTemporaryExpr>(E)->getSubExpr();
5626	goto recurse;
5627
5628	case Expr::CXXFoldExprClass: {
5629	NotPrimaryExpr();
5630	auto *FE = cast<CXXFoldExpr>(E);
5631	if (FE->isLeftFold())
5632	Out << (FE->getInit() ? "fL" : "fl");
5633	else
5634	Out << (FE->getInit() ? "fR" : "fr");
5635
5636	if (FE->getOperator() == BO_PtrMemD)
5637	Out << "ds";
5638	else
5639	mangleOperatorName(
5640	BinaryOperator::getOverloadedOperator(Opc: FE->getOperator()),
5641	/*Arity=*/2);
5642
5643	if (FE->getLHS())
5644	mangleExpression(E: FE->getLHS());
5645	if (FE->getRHS())
5646	mangleExpression(E: FE->getRHS());
5647	break;
5648	}
5649
5650	case Expr::CXXThisExprClass:
5651	NotPrimaryExpr();
5652	Out << "fpT";
5653	break;
5654
5655	case Expr::CoawaitExprClass:
5656	// FIXME: Propose a non-vendor mangling.
5657	NotPrimaryExpr();
5658	Out << "v18co_await";
5659	mangleExpression(E: cast<CoawaitExpr>(E)->getOperand());
5660	break;
5661
5662	case Expr::DependentCoawaitExprClass:
5663	// FIXME: Propose a non-vendor mangling.
5664	NotPrimaryExpr();
5665	Out << "v18co_await";
5666	mangleExpression(E: cast<DependentCoawaitExpr>(E)->getOperand());
5667	break;
5668
5669	case Expr::CoyieldExprClass:
5670	// FIXME: Propose a non-vendor mangling.
5671	NotPrimaryExpr();
5672	Out << "v18co_yield";
5673	mangleExpression(E: cast<CoawaitExpr>(E)->getOperand());
5674	break;
5675	case Expr::SYCLUniqueStableNameExprClass: {
5676	const auto *USN = cast<SYCLUniqueStableNameExpr>(E);
5677	NotPrimaryExpr();
5678
5679	Out << "u33__builtin_sycl_unique_stable_name";
5680	mangleType(USN->getTypeSourceInfo()->getType());
5681
5682	Out << "E";
5683	break;
5684	}
5685	}
5686
5687	if (AsTemplateArg && !IsPrimaryExpr)
5688	Out << 'E';
5689	}
5690
5691	/// Mangle an expression which refers to a parameter variable.
5692	///
5693	/// <expression> ::= <function-param>
5694	/// <function-param> ::= fp <top-level CV-qualifiers> _ # L == 0, I == 0
5695	/// <function-param> ::= fp <top-level CV-qualifiers>
5696	/// <parameter-2 non-negative number> _ # L == 0, I > 0
5697	/// <function-param> ::= fL <L-1 non-negative number>
5698	/// p <top-level CV-qualifiers> _ # L > 0, I == 0
5699	/// <function-param> ::= fL <L-1 non-negative number>
5700	/// p <top-level CV-qualifiers>
5701	/// <I-1 non-negative number> _ # L > 0, I > 0
5702	///
5703	/// L is the nesting depth of the parameter, defined as 1 if the
5704	/// parameter comes from the innermost function prototype scope
5705	/// enclosing the current context, 2 if from the next enclosing
5706	/// function prototype scope, and so on, with one special case: if
5707	/// we've processed the full parameter clause for the innermost
5708	/// function type, then L is one less. This definition conveniently
5709	/// makes it irrelevant whether a function's result type was written
5710	/// trailing or leading, but is otherwise overly complicated; the
5711	/// numbering was first designed without considering references to
5712	/// parameter in locations other than return types, and then the
5713	/// mangling had to be generalized without changing the existing
5714	/// manglings.
5715	///
5716	/// I is the zero-based index of the parameter within its parameter
5717	/// declaration clause. Note that the original ABI document describes
5718	/// this using 1-based ordinals.
5719	void CXXNameMangler::mangleFunctionParam(const ParmVarDecl *parm) {
5720	unsigned parmDepth = parm->getFunctionScopeDepth();
5721	unsigned parmIndex = parm->getFunctionScopeIndex();
5722
5723	// Compute 'L'.
5724	// parmDepth does not include the declaring function prototype.
5725	// FunctionTypeDepth does account for that.
5726	assert(parmDepth < FunctionTypeDepth.getDepth());
5727	unsigned nestingDepth = FunctionTypeDepth.getDepth() - parmDepth;
5728	if (FunctionTypeDepth.isInResultType())
5729	nestingDepth--;
5730
5731	if (nestingDepth == 0) {
5732	Out << "fp";
5733	} else {
5734	Out << "fL" << (nestingDepth - 1) << 'p';
5735	}
5736
5737	// Top-level qualifiers. We don't have to worry about arrays here,
5738	// because parameters declared as arrays should already have been
5739	// transformed to have pointer type. FIXME: apparently these don't
5740	// get mangled if used as an rvalue of a known non-class type?
5741	assert(!parm->getType()->isArrayType()
5742	&& "parameter's type is still an array type?");
5743
5744	if (const DependentAddressSpaceType *DAST =
5745	dyn_cast<DependentAddressSpaceType>(parm->getType())) {
5746	mangleQualifiers(Quals: DAST->getPointeeType().getQualifiers(), DAST);
5747	} else {
5748	mangleQualifiers(Quals: parm->getType().getQualifiers());
5749	}
5750
5751	// Parameter index.
5752	if (parmIndex != 0) {
5753	Out << (parmIndex - 1);
5754	}
5755	Out << '_';
5756	}
5757
5758	void CXXNameMangler::mangleCXXCtorType(CXXCtorType T,
5759	const CXXRecordDecl *InheritedFrom) {
5760	// <ctor-dtor-name> ::= C1 # complete object constructor
5761	// ::= C2 # base object constructor
5762	// ::= CI1 <type> # complete inheriting constructor
5763	// ::= CI2 <type> # base inheriting constructor
5764	//
5765	// In addition, C5 is a comdat name with C1 and C2 in it.
5766	Out << 'C';
5767	if (InheritedFrom)
5768	Out << 'I';
5769	switch (T) {
5770	case Ctor_Complete:
5771	Out << '1';
5772	break;
5773	case Ctor_Base:
5774	Out << '2';
5775	break;
5776	case Ctor_Comdat:
5777	Out << '5';
5778	break;
5779	case Ctor_DefaultClosure:
5780	case Ctor_CopyingClosure:
5781	llvm_unreachable("closure constructors don't exist for the Itanium ABI!");
5782	}
5783	if (InheritedFrom)
5784	mangleName(InheritedFrom);
5785	}
5786
5787	void CXXNameMangler::mangleCXXDtorType(CXXDtorType T) {
5788	// <ctor-dtor-name> ::= D0 # deleting destructor
5789	// ::= D1 # complete object destructor
5790	// ::= D2 # base object destructor
5791	//
5792	// In addition, D5 is a comdat name with D1, D2 and, if virtual, D0 in it.
5793	switch (T) {
5794	case Dtor_Deleting:
5795	Out << "D0";
5796	break;
5797	case Dtor_Complete:
5798	Out << "D1";
5799	break;
5800	case Dtor_Base:
5801	Out << "D2";
5802	break;
5803	case Dtor_Comdat:
5804	Out << "D5";
5805	break;
5806	}
5807	}
5808
5809	// Helper to provide ancillary information on a template used to mangle its
5810	// arguments.
5811	struct CXXNameMangler::TemplateArgManglingInfo {
5812	const CXXNameMangler &Mangler;
5813	TemplateDecl *ResolvedTemplate = nullptr;
5814	bool SeenPackExpansionIntoNonPack = false;
5815	const NamedDecl *UnresolvedExpandedPack = nullptr;
5816
5817	TemplateArgManglingInfo(const CXXNameMangler &Mangler, TemplateName TN)
5818	: Mangler(Mangler) {
5819	if (TemplateDecl *TD = TN.getAsTemplateDecl())
5820	ResolvedTemplate = TD;
5821	}
5822
5823	/// Information about how to mangle a template argument.
5824	struct Info {
5825	/// Do we need to mangle the template argument with an exactly correct type?
5826	bool NeedExactType;
5827	/// If we need to prefix the mangling with a mangling of the template
5828	/// parameter, the corresponding parameter.
5829	const NamedDecl *TemplateParameterToMangle;
5830	};
5831
5832	/// Determine whether the resolved template might be overloaded on its
5833	/// template parameter list. If so, the mangling needs to include enough
5834	/// information to reconstruct the template parameter list.
5835	bool isOverloadable() {
5836	// Function templates are generally overloadable. As a special case, a
5837	// member function template of a generic lambda is not overloadable.
5838	if (auto *FTD = dyn_cast_or_null<FunctionTemplateDecl>(Val: ResolvedTemplate)) {
5839	auto *RD = dyn_cast<CXXRecordDecl>(FTD->getDeclContext());
5840	if (!RD || !RD->isGenericLambda())
5841	return true;
5842	}
5843
5844	// All other templates are not overloadable. Partial specializations would
5845	// be, but we never mangle them.
5846	return false;
5847	}
5848
5849	/// Determine whether we need to prefix this <template-arg> mangling with a
5850	/// <template-param-decl>. This happens if the natural template parameter for
5851	/// the argument mangling is not the same as the actual template parameter.
5852	bool needToMangleTemplateParam(const NamedDecl *Param,
5853	const TemplateArgument &Arg) {
5854	// For a template type parameter, the natural parameter is 'typename T'.
5855	// The actual parameter might be constrained.
5856	if (auto *TTP = dyn_cast<TemplateTypeParmDecl>(Val: Param))
5857	return TTP->hasTypeConstraint();
5858
5859	if (Arg.getKind() == TemplateArgument::Pack) {
5860	// For an empty pack, the natural parameter is `typename...`.
5861	if (Arg.pack_size() == 0)
5862	return true;
5863
5864	// For any other pack, we use the first argument to determine the natural
5865	// template parameter.
5866	return needToMangleTemplateParam(Param, Arg: *Arg.pack_begin());
5867	}
5868
5869	// For a non-type template parameter, the natural parameter is `T V` (for a
5870	// prvalue argument) or `T &V` (for a glvalue argument), where `T` is the
5871	// type of the argument, which we require to exactly match. If the actual
5872	// parameter has a deduced or instantiation-dependent type, it is not
5873	// equivalent to the natural parameter.
5874	if (auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Val: Param))
5875	return NTTP->getType()->isInstantiationDependentType() ||
5876	NTTP->getType()->getContainedDeducedType();
5877
5878	// For a template template parameter, the template-head might differ from
5879	// that of the template.
5880	auto *TTP = cast<TemplateTemplateParmDecl>(Val: Param);
5881	TemplateName ArgTemplateName = Arg.getAsTemplateOrTemplatePattern();
5882	const TemplateDecl *ArgTemplate = ArgTemplateName.getAsTemplateDecl();
5883	if (!ArgTemplate)
5884	return true;
5885
5886	// Mangle the template parameter list of the parameter and argument to see
5887	// if they are the same. We can't use Profile for this, because it can't
5888	// model the depth difference between parameter and argument and might not
5889	// necessarily have the same definition of "identical" that we use here --
5890	// that is, same mangling.
5891	auto MangleTemplateParamListToString =
5892	[&](SmallVectorImpl<char> &Buffer, const TemplateParameterList *Params,
5893	unsigned DepthOffset) {
5894	llvm::raw_svector_ostream Stream(Buffer);
5895	CXXNameMangler(Mangler.Context, Stream,
5896	WithTemplateDepthOffset{.Offset: DepthOffset})
5897	.mangleTemplateParameterList(Params);
5898	};
5899	llvm::SmallString<128> ParamTemplateHead, ArgTemplateHead;
5900	MangleTemplateParamListToString(ParamTemplateHead,
5901	TTP->getTemplateParameters(), 0);
5902	// Add the depth of the parameter's template parameter list to all
5903	// parameters appearing in the argument to make the indexes line up
5904	// properly.
5905	MangleTemplateParamListToString(ArgTemplateHead,
5906	ArgTemplate->getTemplateParameters(),
5907	TTP->getTemplateParameters()->getDepth());
5908	return ParamTemplateHead != ArgTemplateHead;
5909	}
5910
5911	/// Determine information about how this template argument should be mangled.
5912	/// This should be called exactly once for each parameter / argument pair, in
5913	/// order.
5914	Info getArgInfo(unsigned ParamIdx, const TemplateArgument &Arg) {
5915	// We need correct types when the template-name is unresolved or when it
5916	// names a template that is able to be overloaded.
5917	if (!ResolvedTemplate || SeenPackExpansionIntoNonPack)
5918	return {.NeedExactType: true, .TemplateParameterToMangle: nullptr};
5919
5920	// Move to the next parameter.
5921	const NamedDecl *Param = UnresolvedExpandedPack;
5922	if (!Param) {
5923	assert(ParamIdx < ResolvedTemplate->getTemplateParameters()->size() &&
5924	"no parameter for argument");
5925	Param = ResolvedTemplate->getTemplateParameters()->getParam(Idx: ParamIdx);
5926
5927	// If we reach a parameter pack whose argument isn't in pack form, that
5928	// means Sema couldn't or didn't figure out which arguments belonged to
5929	// it, because it contains a pack expansion or because Sema bailed out of
5930	// computing parameter / argument correspondence before this point. Track
5931	// the pack as the corresponding parameter for all further template
5932	// arguments until we hit a pack expansion, at which point we don't know
5933	// the correspondence between parameters and arguments at all.
5934	if (Param->isParameterPack() && Arg.getKind() != TemplateArgument::Pack) {
5935	UnresolvedExpandedPack = Param;
5936	}
5937	}
5938
5939	// If we encounter a pack argument that is expanded into a non-pack
5940	// parameter, we can no longer track parameter / argument correspondence,
5941	// and need to use exact types from this point onwards.
5942	if (Arg.isPackExpansion() &&
5943	(!Param->isParameterPack() || UnresolvedExpandedPack)) {
5944	SeenPackExpansionIntoNonPack = true;
5945	return {.NeedExactType: true, .TemplateParameterToMangle: nullptr};
5946	}
5947
5948	// We need exact types for arguments of a template that might be overloaded
5949	// on template parameter type.
5950	if (isOverloadable())
5951	return {.NeedExactType: true, .TemplateParameterToMangle: needToMangleTemplateParam(Param, Arg) ? Param : nullptr};
5952
5953	// Otherwise, we only need a correct type if the parameter has a deduced
5954	// type.
5955	//
5956	// Note: for an expanded parameter pack, getType() returns the type prior
5957	// to expansion. We could ask for the expanded type with getExpansionType(),
5958	// but it doesn't matter because substitution and expansion don't affect
5959	// whether a deduced type appears in the type.
5960	auto *NTTP = dyn_cast<NonTypeTemplateParmDecl>(Val: Param);
5961	bool NeedExactType = NTTP && NTTP->getType()->getContainedDeducedType();
5962	return {.NeedExactType: NeedExactType, .TemplateParameterToMangle: nullptr};
5963	}
5964
5965	/// Determine if we should mangle a requires-clause after the template
5966	/// argument list. If so, returns the expression to mangle.
5967	const Expr *getTrailingRequiresClauseToMangle() {
5968	if (!isOverloadable())
5969	return nullptr;
5970	return ResolvedTemplate->getTemplateParameters()->getRequiresClause();
5971	}
5972	};
5973
5974	void CXXNameMangler::mangleTemplateArgs(TemplateName TN,
5975	const TemplateArgumentLoc *TemplateArgs,
5976	unsigned NumTemplateArgs) {
5977	// <template-args> ::= I <template-arg>+ [Q <requires-clause expr>] E
5978	Out << 'I';
5979	TemplateArgManglingInfo Info(*this, TN);
5980	for (unsigned i = 0; i != NumTemplateArgs; ++i) {
5981	mangleTemplateArg(Info, Index: i, A: TemplateArgs[i].getArgument());
5982	}
5983	mangleRequiresClause(RequiresClause: Info.getTrailingRequiresClauseToMangle());
5984	Out << 'E';
5985	}
5986
5987	void CXXNameMangler::mangleTemplateArgs(TemplateName TN,
5988	const TemplateArgumentList &AL) {
5989	// <template-args> ::= I <template-arg>+ [Q <requires-clause expr>] E
5990	Out << 'I';
5991	TemplateArgManglingInfo Info(*this, TN);
5992	for (unsigned i = 0, e = AL.size(); i != e; ++i) {
5993	mangleTemplateArg(Info, Index: i, A: AL[i]);
5994	}
5995	mangleRequiresClause(RequiresClause: Info.getTrailingRequiresClauseToMangle());
5996	Out << 'E';
5997	}
5998
5999	void CXXNameMangler::mangleTemplateArgs(TemplateName TN,
6000	ArrayRef<TemplateArgument> Args) {
6001	// <template-args> ::= I <template-arg>+ [Q <requires-clause expr>] E
6002	Out << 'I';
6003	TemplateArgManglingInfo Info(*this, TN);
6004	for (unsigned i = 0; i != Args.size(); ++i) {
6005	mangleTemplateArg(Info, Index: i, A: Args[i]);
6006	}
6007	mangleRequiresClause(RequiresClause: Info.getTrailingRequiresClauseToMangle());
6008	Out << 'E';
6009	}
6010
6011	void CXXNameMangler::mangleTemplateArg(TemplateArgManglingInfo &Info,
6012	unsigned Index, TemplateArgument A) {
6013	TemplateArgManglingInfo::Info ArgInfo = Info.getArgInfo(ParamIdx: Index, Arg: A);
6014
6015	// Proposed on https://github.com/itanium-cxx-abi/cxx-abi/issues/47.
6016	if (ArgInfo.TemplateParameterToMangle &&
6017	!isCompatibleWith(Ver: LangOptions::ClangABI::Ver17)) {
6018	// The template parameter is mangled if the mangling would otherwise be
6019	// ambiguous.
6020	//
6021	// <template-arg> ::= <template-param-decl> <template-arg>
6022	//
6023	// Clang 17 and before did not do this.
6024	mangleTemplateParamDecl(Decl: ArgInfo.TemplateParameterToMangle);
6025	}
6026
6027	mangleTemplateArg(A, NeedExactType: ArgInfo.NeedExactType);
6028	}
6029
6030	void CXXNameMangler::mangleTemplateArg(TemplateArgument A, bool NeedExactType) {
6031	// <template-arg> ::= <type> # type or template
6032	// ::= X <expression> E # expression
6033	// ::= <expr-primary> # simple expressions
6034	// ::= J <template-arg>* E # argument pack
6035	if (!A.isInstantiationDependent() || A.isDependent())
6036	A = Context.getASTContext().getCanonicalTemplateArgument(Arg: A);
6037
6038	switch (A.getKind()) {
6039	case TemplateArgument::Null:
6040	llvm_unreachable("Cannot mangle NULL template argument");
6041
6042	case TemplateArgument::Type:
6043	mangleType(T: A.getAsType());
6044	break;
6045	case TemplateArgument::Template:
6046	// This is mangled as <type>.
6047	mangleType(TN: A.getAsTemplate());
6048	break;
6049	case TemplateArgument::TemplateExpansion:
6050	// <type> ::= Dp <type> # pack expansion (C++0x)
6051	Out << "Dp";
6052	mangleType(TN: A.getAsTemplateOrTemplatePattern());
6053	break;
6054	case TemplateArgument::Expression:
6055	mangleTemplateArgExpr(E: A.getAsExpr());
6056	break;
6057	case TemplateArgument::Integral:
6058	mangleIntegerLiteral(T: A.getIntegralType(), Value: A.getAsIntegral());
6059	break;
6060	case TemplateArgument::Declaration: {
6061	// <expr-primary> ::= L <mangled-name> E # external name
6062	ValueDecl *D = A.getAsDecl();
6063
6064	// Template parameter objects are modeled by reproducing a source form
6065	// produced as if by aggregate initialization.
6066	if (A.getParamTypeForDecl()->isRecordType()) {
6067	auto *TPO = cast<TemplateParamObjectDecl>(Val: D);
6068	mangleValueInTemplateArg(T: TPO->getType().getUnqualifiedType(),
6069	V: TPO->getValue(), /*TopLevel=*/true,
6070	NeedExactType);
6071	break;
6072	}
6073
6074	ASTContext &Ctx = Context.getASTContext();
6075	APValue Value;
6076	if (D->isCXXInstanceMember())
6077	// Simple pointer-to-member with no conversion.
6078	Value = APValue(D, /*IsDerivedMember=*/false, /*Path=*/{});
6079	else if (D->getType()->isArrayType() &&
6080	Ctx.hasSimilarType(T1: Ctx.getDecayedType(T: D->getType()),
6081	T2: A.getParamTypeForDecl()) &&
6082	!isCompatibleWith(Ver: LangOptions::ClangABI::Ver11))
6083	// Build a value corresponding to this implicit array-to-pointer decay.
6084	Value = APValue(APValue::LValueBase(D), CharUnits::Zero(),
6085	{APValue::LValuePathEntry::ArrayIndex(Index: 0)},
6086	/*OnePastTheEnd=*/false);
6087	else
6088	// Regular pointer or reference to a declaration.
6089	Value = APValue(APValue::LValueBase(D), CharUnits::Zero(),
6090	ArrayRef<APValue::LValuePathEntry>(),
6091	/*OnePastTheEnd=*/false);
6092	mangleValueInTemplateArg(T: A.getParamTypeForDecl(), V: Value, /*TopLevel=*/true,
6093	NeedExactType);
6094	break;
6095	}
6096	case TemplateArgument::NullPtr: {
6097	mangleNullPointer(T: A.getNullPtrType());
6098	break;
6099	}
6100	case TemplateArgument::StructuralValue:
6101	mangleValueInTemplateArg(T: A.getStructuralValueType(),
6102	V: A.getAsStructuralValue(),
6103	/*TopLevel=*/true, NeedExactType);
6104	break;
6105	case TemplateArgument::Pack: {
6106	// <template-arg> ::= J <template-arg>* E
6107	Out << 'J';
6108	for (const auto &P : A.pack_elements())
6109	mangleTemplateArg(A: P, NeedExactType);
6110	Out << 'E';
6111	}
6112	}
6113	}
6114
6115	void CXXNameMangler::mangleTemplateArgExpr(const Expr *E) {
6116	if (!isCompatibleWith(Ver: LangOptions::ClangABI::Ver11)) {
6117	mangleExpression(E, Arity: UnknownArity, /*AsTemplateArg=*/true);
6118	return;
6119	}
6120
6121	// Prior to Clang 12, we didn't omit the X .. E around <expr-primary>
6122	// correctly in cases where the template argument was
6123	// constructed from an expression rather than an already-evaluated
6124	// literal. In such a case, we would then e.g. emit 'XLi0EE' instead of
6125	// 'Li0E'.
6126	//
6127	// We did special-case DeclRefExpr to attempt to DTRT for that one
6128	// expression-kind, but while doing so, unfortunately handled ParmVarDecl
6129	// (subtype of VarDecl) _incorrectly_, and emitted 'L_Z .. E' instead of
6130	// the proper 'Xfp_E'.
6131	E = E->IgnoreParenImpCasts();
6132	if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Val: E)) {
6133	const ValueDecl *D = DRE->getDecl();
6134	if (isa<VarDecl>(Val: D) || isa<FunctionDecl>(Val: D)) {
6135	Out << 'L';
6136	mangle(D);
6137	Out << 'E';
6138	return;
6139	}
6140	}
6141	Out << 'X';
6142	mangleExpression(E);
6143	Out << 'E';
6144	}
6145
6146	/// Determine whether a given value is equivalent to zero-initialization for
6147	/// the purpose of discarding a trailing portion of a 'tl' mangling.
6148	///
6149	/// Note that this is not in general equivalent to determining whether the
6150	/// value has an all-zeroes bit pattern.
6151	static bool isZeroInitialized(QualType T, const APValue &V) {
6152	// FIXME: mangleValueInTemplateArg has quadratic time complexity in
6153	// pathological cases due to using this, but it's a little awkward
6154	// to do this in linear time in general.
6155	switch (V.getKind()) {
6156	case APValue::None:
6157	case APValue::Indeterminate:
6158	case APValue::AddrLabelDiff:
6159	return false;
6160
6161	case APValue::Struct: {
6162	const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
6163	assert(RD && "unexpected type for record value");
6164	unsigned I = 0;
6165	for (const CXXBaseSpecifier &BS : RD->bases()) {
6166	if (!isZeroInitialized(T: BS.getType(), V: V.getStructBase(i: I)))
6167	return false;
6168	++I;
6169	}
6170	I = 0;
6171	for (const FieldDecl *FD : RD->fields()) {
6172	if (!FD->isUnnamedBitfield() &&
6173	!isZeroInitialized(FD->getType(), V.getStructField(I)))
6174	return false;
6175	++I;
6176	}
6177	return true;
6178	}
6179
6180	case APValue::Union: {
6181	const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
6182	assert(RD && "unexpected type for union value");
6183	// Zero-initialization zeroes the first non-unnamed-bitfield field, if any.
6184	for (const FieldDecl *FD : RD->fields()) {
6185	if (!FD->isUnnamedBitfield())
6186	return V.getUnionField() && declaresSameEntity(FD, V.getUnionField()) &&
6187	isZeroInitialized(FD->getType(), V.getUnionValue());
6188	}
6189	// If there are no fields (other than unnamed bitfields), the value is
6190	// necessarily zero-initialized.
6191	return true;
6192	}
6193
6194	case APValue::Array: {
6195	QualType ElemT(T->getArrayElementTypeNoTypeQual(), 0);
6196	for (unsigned I = 0, N = V.getArrayInitializedElts(); I != N; ++I)
6197	if (!isZeroInitialized(T: ElemT, V: V.getArrayInitializedElt(I)))
6198	return false;
6199	return !V.hasArrayFiller() || isZeroInitialized(T: ElemT, V: V.getArrayFiller());
6200	}
6201
6202	case APValue::Vector: {
6203	const VectorType *VT = T->castAs<VectorType>();
6204	for (unsigned I = 0, N = V.getVectorLength(); I != N; ++I)
6205	if (!isZeroInitialized(T: VT->getElementType(), V: V.getVectorElt(I)))
6206	return false;
6207	return true;
6208	}
6209
6210	case APValue::Int:
6211	return !V.getInt();
6212
6213	case APValue::Float:
6214	return V.getFloat().isPosZero();
6215
6216	case APValue::FixedPoint:
6217	return !V.getFixedPoint().getValue();
6218
6219	case APValue::ComplexFloat:
6220	return V.getComplexFloatReal().isPosZero() &&
6221	V.getComplexFloatImag().isPosZero();
6222
6223	case APValue::ComplexInt:
6224	return !V.getComplexIntReal() && !V.getComplexIntImag();
6225
6226	case APValue::LValue:
6227	return V.isNullPointer();
6228
6229	case APValue::MemberPointer:
6230	return !V.getMemberPointerDecl();
6231	}
6232
6233	llvm_unreachable("Unhandled APValue::ValueKind enum");
6234	}
6235
6236	static QualType getLValueType(ASTContext &Ctx, const APValue &LV) {
6237	QualType T = LV.getLValueBase().getType();
6238	for (APValue::LValuePathEntry E : LV.getLValuePath()) {
6239	if (const ArrayType *AT = Ctx.getAsArrayType(T))
6240	T = AT->getElementType();
6241	else if (const FieldDecl *FD =
6242	dyn_cast<FieldDecl>(Val: E.getAsBaseOrMember().getPointer()))
6243	T = FD->getType();
6244	else
6245	T = Ctx.getRecordType(
6246	cast<CXXRecordDecl>(Val: E.getAsBaseOrMember().getPointer()));
6247	}
6248	return T;
6249	}
6250
6251	static IdentifierInfo *getUnionInitName(SourceLocation UnionLoc,
6252	DiagnosticsEngine &Diags,
6253	const FieldDecl *FD) {
6254	// According to:
6255	// http://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangling.anonymous
6256	// For the purposes of mangling, the name of an anonymous union is considered
6257	// to be the name of the first named data member found by a pre-order,
6258	// depth-first, declaration-order walk of the data members of the anonymous
6259	// union.
6260
6261	if (FD->getIdentifier())
6262	return FD->getIdentifier();
6263
6264	// The only cases where the identifer of a FieldDecl would be blank is if the
6265	// field represents an anonymous record type or if it is an unnamed bitfield.
6266	// There is no type to descend into in the case of a bitfield, so we can just
6267	// return nullptr in that case.
6268	if (FD->isBitField())
6269	return nullptr;
6270	const CXXRecordDecl *RD = FD->getType()->getAsCXXRecordDecl();
6271
6272	// Consider only the fields in declaration order, searched depth-first. We
6273	// don't care about the active member of the union, as all we are doing is
6274	// looking for a valid name. We also don't check bases, due to guidance from
6275	// the Itanium ABI folks.
6276	for (const FieldDecl *RDField : RD->fields()) {
6277	if (IdentifierInfo *II = getUnionInitName(UnionLoc, Diags, RDField))
6278	return II;
6279	}
6280
6281	// According to the Itanium ABI: If there is no such data member (i.e., if all
6282	// of the data members in the union are unnamed), then there is no way for a
6283	// program to refer to the anonymous union, and there is therefore no need to
6284	// mangle its name. However, we should diagnose this anyway.
6285	unsigned DiagID = Diags.getCustomDiagID(
6286	L: DiagnosticsEngine::Error, FormatString: "cannot mangle this unnamed union NTTP yet");
6287	Diags.Report(Loc: UnionLoc, DiagID);
6288
6289	return nullptr;
6290	}
6291
6292	void CXXNameMangler::mangleValueInTemplateArg(QualType T, const APValue &V,
6293	bool TopLevel,
6294	bool NeedExactType) {
6295	// Ignore all top-level cv-qualifiers, to match GCC.
6296	Qualifiers Quals;
6297	T = getASTContext().getUnqualifiedArrayType(T, Quals);
6298
6299	// A top-level expression that's not a primary expression is wrapped in X...E.
6300	bool IsPrimaryExpr = true;
6301	auto NotPrimaryExpr = [&] {
6302	if (TopLevel && IsPrimaryExpr)
6303	Out << 'X';
6304	IsPrimaryExpr = false;
6305	};
6306
6307	// Proposed in https://github.com/itanium-cxx-abi/cxx-abi/issues/63.
6308	switch (V.getKind()) {
6309	case APValue::None:
6310	case APValue::Indeterminate:
6311	Out << 'L';
6312	mangleType(T);
6313	Out << 'E';
6314	break;
6315
6316	case APValue::AddrLabelDiff:
6317	llvm_unreachable("unexpected value kind in template argument");
6318
6319	case APValue::Struct: {
6320	const CXXRecordDecl *RD = T->getAsCXXRecordDecl();
6321	assert(RD && "unexpected type for record value");
6322
6323	// Drop trailing zero-initialized elements.
6324	llvm::SmallVector<const FieldDecl *, 16> Fields(RD->fields());
6325	while (
6326	!Fields.empty() &&
6327	(Fields.back()->isUnnamedBitfield() ||
6328	isZeroInitialized(Fields.back()->getType(),
6329	V.getStructField(i: Fields.back()->getFieldIndex())))) {
6330	Fields.pop_back();
6331	}
6332	llvm::ArrayRef<CXXBaseSpecifier> Bases(RD->bases_begin(), RD->bases_end());
6333	if (Fields.empty()) {
6334	while (!Bases.empty() &&
6335	isZeroInitialized(T: Bases.back().getType(),
6336	V: V.getStructBase(i: Bases.size() - 1)))
6337	Bases = Bases.drop_back();
6338	}
6339
6340	// <expression> ::= tl <type> <braced-expression>* E
6341	NotPrimaryExpr();
6342	Out << "tl";
6343	mangleType(T);
6344	for (unsigned I = 0, N = Bases.size(); I != N; ++I)
6345	mangleValueInTemplateArg(T: Bases[I].getType(), V: V.getStructBase(i: I), TopLevel: false);
6346	for (unsigned I = 0, N = Fields.size(); I != N; ++I) {
6347	if (Fields[I]->isUnnamedBitfield())
6348	continue;
6349	mangleValueInTemplateArg(T: Fields[I]->getType(),
6350	V: V.getStructField(i: Fields[I]->getFieldIndex()),
6351	TopLevel: false);
6352	}
6353	Out << 'E';
6354	break;
6355	}
6356
6357	case APValue::Union: {
6358	assert(T->getAsCXXRecordDecl() && "unexpected type for union value");
6359	const FieldDecl *FD = V.getUnionField();
6360
6361	if (!FD) {
6362	Out << 'L';
6363	mangleType(T);
6364	Out << 'E';
6365	break;
6366	}
6367
6368	// <braced-expression> ::= di <field source-name> <braced-expression>
6369	NotPrimaryExpr();
6370	Out << "tl";
6371	mangleType(T);
6372	if (!isZeroInitialized(T, V)) {
6373	Out << "di";
6374	IdentifierInfo *II = (getUnionInitName(
6375	T->getAsCXXRecordDecl()->getLocation(), Context.getDiags(), FD));
6376	if (II)
6377	mangleSourceName(II);
6378	mangleValueInTemplateArg(T: FD->getType(), V: V.getUnionValue(), TopLevel: false);
6379	}
6380	Out << 'E';
6381	break;
6382	}
6383
6384	case APValue::Array: {
6385	QualType ElemT(T->getArrayElementTypeNoTypeQual(), 0);
6386
6387	NotPrimaryExpr();
6388	Out << "tl";
6389	mangleType(T);
6390
6391	// Drop trailing zero-initialized elements.
6392	unsigned N = V.getArraySize();
6393	if (!V.hasArrayFiller() || isZeroInitialized(T: ElemT, V: V.getArrayFiller())) {
6394	N = V.getArrayInitializedElts();
6395	while (N && isZeroInitialized(T: ElemT, V: V.getArrayInitializedElt(I: N - 1)))
6396	--N;
6397	}
6398
6399	for (unsigned I = 0; I != N; ++I) {
6400	const APValue &Elem = I < V.getArrayInitializedElts()
6401	? V.getArrayInitializedElt(I)
6402	: V.getArrayFiller();
6403	mangleValueInTemplateArg(T: ElemT, V: Elem, TopLevel: false);
6404	}
6405	Out << 'E';
6406	break;
6407	}
6408
6409	case APValue::Vector: {
6410	const VectorType *VT = T->castAs<VectorType>();
6411
6412	NotPrimaryExpr();
6413	Out << "tl";
6414	mangleType(T);
6415	unsigned N = V.getVectorLength();
6416	while (N && isZeroInitialized(T: VT->getElementType(), V: V.getVectorElt(I: N - 1)))
6417	--N;
6418	for (unsigned I = 0; I != N; ++I)
6419	mangleValueInTemplateArg(T: VT->getElementType(), V: V.getVectorElt(I), TopLevel: false);
6420	Out << 'E';
6421	break;
6422	}
6423
6424	case APValue::Int:
6425	mangleIntegerLiteral(T, Value: V.getInt());
6426	break;
6427
6428	case APValue::Float:
6429	mangleFloatLiteral(T, V: V.getFloat());
6430	break;
6431
6432	case APValue::FixedPoint:
6433	mangleFixedPointLiteral();
6434	break;
6435
6436	case APValue::ComplexFloat: {
6437	const ComplexType *CT = T->castAs<ComplexType>();
6438	NotPrimaryExpr();
6439	Out << "tl";
6440	mangleType(T);
6441	if (!V.getComplexFloatReal().isPosZero() ||
6442	!V.getComplexFloatImag().isPosZero())
6443	mangleFloatLiteral(T: CT->getElementType(), V: V.getComplexFloatReal());
6444	if (!V.getComplexFloatImag().isPosZero())
6445	mangleFloatLiteral(T: CT->getElementType(), V: V.getComplexFloatImag());
6446	Out << 'E';
6447	break;
6448	}
6449
6450	case APValue::ComplexInt: {
6451	const ComplexType *CT = T->castAs<ComplexType>();
6452	NotPrimaryExpr();
6453	Out << "tl";
6454	mangleType(T);
6455	if (V.getComplexIntReal().getBoolValue() ||
6456	V.getComplexIntImag().getBoolValue())
6457	mangleIntegerLiteral(T: CT->getElementType(), Value: V.getComplexIntReal());
6458	if (V.getComplexIntImag().getBoolValue())
6459	mangleIntegerLiteral(T: CT->getElementType(), Value: V.getComplexIntImag());
6460	Out << 'E';
6461	break;
6462	}
6463
6464	case APValue::LValue: {
6465	// Proposed in https://github.com/itanium-cxx-abi/cxx-abi/issues/47.
6466	assert((T->isPointerType() || T->isReferenceType()) &&
6467	"unexpected type for LValue template arg");
6468
6469	if (V.isNullPointer()) {
6470	mangleNullPointer(T);
6471	break;
6472	}
6473
6474	APValue::LValueBase B = V.getLValueBase();
6475	if (!B) {
6476	// Non-standard mangling for integer cast to a pointer; this can only
6477	// occur as an extension.
6478	CharUnits Offset = V.getLValueOffset();
6479	if (Offset.isZero()) {
6480	// This is reinterpret_cast<T*>(0), not a null pointer. Mangle this as
6481	// a cast, because L <type> 0 E means something else.
6482	NotPrimaryExpr();
6483	Out << "rc";
6484	mangleType(T);
6485	Out << "Li0E";
6486	if (TopLevel)
6487	Out << 'E';
6488	} else {
6489	Out << "L";
6490	mangleType(T);
6491	Out << Offset.getQuantity() << 'E';
6492	}
6493	break;
6494	}
6495
6496	ASTContext &Ctx = Context.getASTContext();
6497
6498	enum { Base, Offset, Path } Kind;
6499	if (!V.hasLValuePath()) {
6500	// Mangle as (T*)((char*)&base + N).
6501	if (T->isReferenceType()) {
6502	NotPrimaryExpr();
6503	Out << "decvP";
6504	mangleType(T: T->getPointeeType());
6505	} else {
6506	NotPrimaryExpr();
6507	Out << "cv";
6508	mangleType(T);
6509	}
6510	Out << "plcvPcad";
6511	Kind = Offset;
6512	} else {
6513	// Clang 11 and before mangled an array subject to array-to-pointer decay
6514	// as if it were the declaration itself.
6515	bool IsArrayToPointerDecayMangledAsDecl = false;
6516	if (TopLevel && Ctx.getLangOpts().getClangABICompat() <=
6517	LangOptions::ClangABI::Ver11) {
6518	QualType BType = B.getType();
6519	IsArrayToPointerDecayMangledAsDecl =
6520	BType->isArrayType() && V.getLValuePath().size() == 1 &&
6521	V.getLValuePath()[0].getAsArrayIndex() == 0 &&
6522	Ctx.hasSimilarType(T1: T, T2: Ctx.getDecayedType(T: BType));
6523	}
6524
6525	if ((!V.getLValuePath().empty() || V.isLValueOnePastTheEnd()) &&
6526	!IsArrayToPointerDecayMangledAsDecl) {
6527	NotPrimaryExpr();
6528	// A final conversion to the template parameter's type is usually
6529	// folded into the 'so' mangling, but we can't do that for 'void*'
6530	// parameters without introducing collisions.
6531	if (NeedExactType && T->isVoidPointerType()) {
6532	Out << "cv";
6533	mangleType(T);
6534	}
6535	if (T->isPointerType())
6536	Out << "ad";
6537	Out << "so";
6538	mangleType(T: T->isVoidPointerType()
6539	? getLValueType(Ctx, LV: V).getUnqualifiedType()
6540	: T->getPointeeType());
6541	Kind = Path;
6542	} else {
6543	if (NeedExactType &&
6544	!Ctx.hasSameType(T1: T->getPointeeType(), T2: getLValueType(Ctx, LV: V)) &&
6545	!isCompatibleWith(Ver: LangOptions::ClangABI::Ver11)) {
6546	NotPrimaryExpr();
6547	Out << "cv";
6548	mangleType(T);
6549	}
6550	if (T->isPointerType()) {
6551	NotPrimaryExpr();
6552	Out << "ad";
6553	}
6554	Kind = Base;
6555	}
6556	}
6557
6558	QualType TypeSoFar = B.getType();
6559	if (auto *VD = B.dyn_cast<const ValueDecl*>()) {
6560	Out << 'L';
6561	mangle(VD);
6562	Out << 'E';
6563	} else if (auto *E = B.dyn_cast<const Expr*>()) {
6564	NotPrimaryExpr();
6565	mangleExpression(E);
6566	} else if (auto TI = B.dyn_cast<TypeInfoLValue>()) {
6567	NotPrimaryExpr();
6568	Out << "ti";
6569	mangleType(T: QualType(TI.getType(), 0));
6570	} else {
6571	// We should never see dynamic allocations here.
6572	llvm_unreachable("unexpected lvalue base kind in template argument");
6573	}
6574
6575	switch (Kind) {
6576	case Base:
6577	break;
6578
6579	case Offset:
6580	Out << 'L';
6581	mangleType(T: Ctx.getPointerDiffType());
6582	mangleNumber(Number: V.getLValueOffset().getQuantity());
6583	Out << 'E';
6584	break;
6585
6586	case Path:
6587	// <expression> ::= so <referent type> <expr> [<offset number>]
6588	// <union-selector>* [p] E
6589	if (!V.getLValueOffset().isZero())
6590	mangleNumber(Number: V.getLValueOffset().getQuantity());
6591
6592	// We model a past-the-end array pointer as array indexing with index N,
6593	// not with the "past the end" flag. Compensate for that.
6594	bool OnePastTheEnd = V.isLValueOnePastTheEnd();
6595
6596	for (APValue::LValuePathEntry E : V.getLValuePath()) {
6597	if (auto *AT = TypeSoFar->getAsArrayTypeUnsafe()) {
6598	if (auto *CAT = dyn_cast<ConstantArrayType>(AT))
6599	OnePastTheEnd |= CAT->getSize() == E.getAsArrayIndex();
6600	TypeSoFar = AT->getElementType();
6601	} else {
6602	const Decl *D = E.getAsBaseOrMember().getPointer();
6603	if (auto *FD = dyn_cast<FieldDecl>(Val: D)) {
6604	// <union-selector> ::= _ <number>
6605	if (FD->getParent()->isUnion()) {
6606	Out << '_';
6607	if (FD->getFieldIndex())
6608	Out << (FD->getFieldIndex() - 1);
6609	}
6610	TypeSoFar = FD->getType();
6611	} else {
6612	TypeSoFar = Ctx.getRecordType(cast<CXXRecordDecl>(Val: D));
6613	}
6614	}
6615	}
6616
6617	if (OnePastTheEnd)
6618	Out << 'p';
6619	Out << 'E';
6620	break;
6621	}
6622
6623	break;
6624	}
6625
6626	case APValue::MemberPointer:
6627	// Proposed in https://github.com/itanium-cxx-abi/cxx-abi/issues/47.
6628	if (!V.getMemberPointerDecl()) {
6629	mangleNullPointer(T);
6630	break;
6631	}
6632
6633	ASTContext &Ctx = Context.getASTContext();
6634
6635	NotPrimaryExpr();
6636	if (!V.getMemberPointerPath().empty()) {
6637	Out << "mc";
6638	mangleType(T);
6639	} else if (NeedExactType &&
6640	!Ctx.hasSameType(
6641	T1: T->castAs<MemberPointerType>()->getPointeeType(),
6642	T2: V.getMemberPointerDecl()->getType()) &&
6643	!isCompatibleWith(Ver: LangOptions::ClangABI::Ver11)) {
6644	Out << "cv";
6645	mangleType(T);
6646	}
6647	Out << "adL";
6648	mangle(V.getMemberPointerDecl());
6649	Out << 'E';
6650	if (!V.getMemberPointerPath().empty()) {
6651	CharUnits Offset =
6652	Context.getASTContext().getMemberPointerPathAdjustment(MP: V);
6653	if (!Offset.isZero())
6654	mangleNumber(Number: Offset.getQuantity());
6655	Out << 'E';
6656	}
6657	break;
6658	}
6659
6660	if (TopLevel && !IsPrimaryExpr)
6661	Out << 'E';
6662	}
6663
6664	void CXXNameMangler::mangleTemplateParameter(unsigned Depth, unsigned Index) {
6665	// <template-param> ::= T_ # first template parameter
6666	// ::= T <parameter-2 non-negative number> _
6667	// ::= TL <L-1 non-negative number> __
6668	// ::= TL <L-1 non-negative number> _
6669	// <parameter-2 non-negative number> _
6670	//
6671	// The latter two manglings are from a proposal here:
6672	// https://github.com/itanium-cxx-abi/cxx-abi/issues/31#issuecomment-528122117
6673	Out << 'T';
6674	Depth += TemplateDepthOffset;
6675	if (Depth != 0)
6676	Out << 'L' << (Depth - 1) << '_';
6677	if (Index != 0)
6678	Out << (Index - 1);
6679	Out << '_';
6680	}
6681
6682	void CXXNameMangler::mangleSeqID(unsigned SeqID) {
6683	if (SeqID == 0) {
6684	// Nothing.
6685	} else if (SeqID == 1) {
6686	Out << '0';
6687	} else {
6688	SeqID--;
6689
6690	// <seq-id> is encoded in base-36, using digits and upper case letters.
6691	char Buffer[7]; // log(2**32) / log(36) ~= 7
6692	MutableArrayRef<char> BufferRef(Buffer);
6693	MutableArrayRef<char>::reverse_iterator I = BufferRef.rbegin();
6694
6695	for (; SeqID != 0; SeqID /= 36) {
6696	unsigned C = SeqID % 36;
6697	*I++ = (C < 10 ? '0' + C : 'A' + C - 10);
6698	}
6699
6700	Out.write(Ptr: I.base(), Size: I - BufferRef.rbegin());
6701	}
6702	Out << '_';
6703	}
6704
6705	void CXXNameMangler::mangleExistingSubstitution(TemplateName tname) {
6706	bool result = mangleSubstitution(Template: tname);
6707	assert(result && "no existing substitution for template name");
6708	(void) result;
6709	}
6710
6711	// <substitution> ::= S <seq-id> _
6712	// ::= S_
6713	bool CXXNameMangler::mangleSubstitution(const NamedDecl *ND) {
6714	// Try one of the standard substitutions first.
6715	if (mangleStandardSubstitution(ND))
6716	return true;
6717
6718	ND = cast<NamedDecl>(ND->getCanonicalDecl());
6719	return mangleSubstitution(Ptr: reinterpret_cast<uintptr_t>(ND));
6720	}
6721
6722	bool CXXNameMangler::mangleSubstitution(NestedNameSpecifier *NNS) {
6723	assert(NNS->getKind() == NestedNameSpecifier::Identifier &&
6724	"mangleSubstitution(NestedNameSpecifier *) is only used for "
6725	"identifier nested name specifiers.");
6726	NNS = Context.getASTContext().getCanonicalNestedNameSpecifier(NNS);
6727	return mangleSubstitution(Ptr: reinterpret_cast<uintptr_t>(NNS));
6728	}
6729
6730	/// Determine whether the given type has any qualifiers that are relevant for
6731	/// substitutions.
6732	static bool hasMangledSubstitutionQualifiers(QualType T) {
6733	Qualifiers Qs = T.getQualifiers();
6734	return Qs.getCVRQualifiers() || Qs.hasAddressSpace() || Qs.hasUnaligned();
6735	}
6736
6737	bool CXXNameMangler::mangleSubstitution(QualType T) {
6738	if (!hasMangledSubstitutionQualifiers(T)) {
6739	if (const RecordType *RT = T->getAs<RecordType>())
6740	return mangleSubstitution(RT->getDecl());
6741	}
6742
6743	uintptr_t TypePtr = reinterpret_cast<uintptr_t>(T.getAsOpaquePtr());
6744
6745	return mangleSubstitution(Ptr: TypePtr);
6746	}
6747
6748	bool CXXNameMangler::mangleSubstitution(TemplateName Template) {
6749	if (TemplateDecl *TD = Template.getAsTemplateDecl())
6750	return mangleSubstitution(TD);
6751
6752	Template = Context.getASTContext().getCanonicalTemplateName(Name: Template);
6753	return mangleSubstitution(
6754	Ptr: reinterpret_cast<uintptr_t>(Template.getAsVoidPointer()));
6755	}
6756
6757	bool CXXNameMangler::mangleSubstitution(uintptr_t Ptr) {
6758	llvm::DenseMap<uintptr_t, unsigned>::iterator I = Substitutions.find(Val: Ptr);
6759	if (I == Substitutions.end())
6760	return false;
6761
6762	unsigned SeqID = I->second;
6763	Out << 'S';
6764	mangleSeqID(SeqID);
6765
6766	return true;
6767	}
6768
6769	/// Returns whether S is a template specialization of std::Name with a single
6770	/// argument of type A.
6771	bool CXXNameMangler::isSpecializedAs(QualType S, llvm::StringRef Name,
6772	QualType A) {
6773	if (S.isNull())
6774	return false;
6775
6776	const RecordType *RT = S->getAs<RecordType>();
6777	if (!RT)
6778	return false;
6779
6780	const ClassTemplateSpecializationDecl *SD =
6781	dyn_cast<ClassTemplateSpecializationDecl>(Val: RT->getDecl());
6782	if (!SD || !SD->getIdentifier()->isStr(Name))
6783	return false;
6784
6785	if (!isStdNamespace(DC: Context.getEffectiveDeclContext(SD)))
6786	return false;
6787
6788	const TemplateArgumentList &TemplateArgs = SD->getTemplateArgs();
6789	if (TemplateArgs.size() != 1)
6790	return false;
6791
6792	if (TemplateArgs[0].getAsType() != A)
6793	return false;
6794
6795	if (SD->getSpecializedTemplate()->getOwningModuleForLinkage())
6796	return false;
6797
6798	return true;
6799	}
6800
6801	/// Returns whether SD is a template specialization std::Name<char,
6802	/// std::char_traits<char> [, std::allocator<char>]>
6803	/// HasAllocator controls whether the 3rd template argument is needed.
6804	bool CXXNameMangler::isStdCharSpecialization(
6805	const ClassTemplateSpecializationDecl *SD, llvm::StringRef Name,
6806	bool HasAllocator) {
6807	if (!SD->getIdentifier()->isStr(Name))
6808	return false;
6809
6810	const TemplateArgumentList &TemplateArgs = SD->getTemplateArgs();
6811	if (TemplateArgs.size() != (HasAllocator ? 3 : 2))
6812	return false;
6813
6814	QualType A = TemplateArgs[0].getAsType();
6815	if (A.isNull())
6816	return false;
6817	// Plain 'char' is named Char_S or Char_U depending on the target ABI.
6818	if (!A->isSpecificBuiltinType(K: BuiltinType::Char_S) &&
6819	!A->isSpecificBuiltinType(K: BuiltinType::Char_U))
6820	return false;
6821
6822	if (!isSpecializedAs(S: TemplateArgs[1].getAsType(), Name: "char_traits", A))
6823	return false;
6824
6825	if (HasAllocator &&
6826	!isSpecializedAs(S: TemplateArgs[2].getAsType(), Name: "allocator", A))
6827	return false;
6828
6829	if (SD->getSpecializedTemplate()->getOwningModuleForLinkage())
6830	return false;
6831
6832	return true;
6833	}
6834
6835	bool CXXNameMangler::mangleStandardSubstitution(const NamedDecl *ND) {
6836	// <substitution> ::= St # ::std::
6837	if (const NamespaceDecl *NS = dyn_cast<NamespaceDecl>(Val: ND)) {
6838	if (isStd(NS)) {
6839	Out << "St";
6840	return true;
6841	}
6842	return false;
6843	}
6844
6845	if (const ClassTemplateDecl *TD = dyn_cast<ClassTemplateDecl>(Val: ND)) {
6846	if (!isStdNamespace(DC: Context.getEffectiveDeclContext(TD)))
6847	return false;
6848
6849	if (TD->getOwningModuleForLinkage())
6850	return false;
6851
6852	// <substitution> ::= Sa # ::std::allocator
6853	if (TD->getIdentifier()->isStr("allocator")) {
6854	Out << "Sa";
6855	return true;
6856	}
6857
6858	// <<substitution> ::= Sb # ::std::basic_string
6859	if (TD->getIdentifier()->isStr("basic_string")) {
6860	Out << "Sb";
6861	return true;
6862	}
6863	return false;
6864	}
6865
6866	if (const ClassTemplateSpecializationDecl *SD =
6867	dyn_cast<ClassTemplateSpecializationDecl>(Val: ND)) {
6868	if (!isStdNamespace(DC: Context.getEffectiveDeclContext(SD)))
6869	return false;
6870
6871	if (SD->getSpecializedTemplate()->getOwningModuleForLinkage())
6872	return false;
6873
6874	// <substitution> ::= Ss # ::std::basic_string<char,
6875	// ::std::char_traits<char>,
6876	// ::std::allocator<char> >
6877	if (isStdCharSpecialization(SD, Name: "basic_string", /*HasAllocator=*/true)) {
6878	Out << "Ss";
6879	return true;
6880	}
6881
6882	// <substitution> ::= Si # ::std::basic_istream<char,
6883	// ::std::char_traits<char> >
6884	if (isStdCharSpecialization(SD, Name: "basic_istream", /*HasAllocator=*/false)) {
6885	Out << "Si";
6886	return true;
6887	}
6888
6889	// <substitution> ::= So # ::std::basic_ostream<char,
6890	// ::std::char_traits<char> >
6891	if (isStdCharSpecialization(SD, Name: "basic_ostream", /*HasAllocator=*/false)) {
6892	Out << "So";
6893	return true;
6894	}
6895
6896	// <substitution> ::= Sd # ::std::basic_iostream<char,
6897	// ::std::char_traits<char> >
6898	if (isStdCharSpecialization(SD, Name: "basic_iostream", /*HasAllocator=*/false)) {
6899	Out << "Sd";
6900	return true;
6901	}
6902	return false;
6903	}
6904
6905	return false;
6906	}
6907
6908	void CXXNameMangler::addSubstitution(QualType T) {
6909	if (!hasMangledSubstitutionQualifiers(T)) {
6910	if (const RecordType *RT = T->getAs<RecordType>()) {
6911	addSubstitution(RT->getDecl());
6912	return;
6913	}
6914	}
6915
6916	uintptr_t TypePtr = reinterpret_cast<uintptr_t>(T.getAsOpaquePtr());
6917	addSubstitution(Ptr: TypePtr);
6918	}
6919
6920	void CXXNameMangler::addSubstitution(TemplateName Template) {
6921	if (TemplateDecl *TD = Template.getAsTemplateDecl())
6922	return addSubstitution(TD);
6923
6924	Template = Context.getASTContext().getCanonicalTemplateName(Name: Template);
6925	addSubstitution(Ptr: reinterpret_cast<uintptr_t>(Template.getAsVoidPointer()));
6926	}
6927
6928	void CXXNameMangler::addSubstitution(uintptr_t Ptr) {
6929	assert(!Substitutions.count(Ptr) && "Substitution already exists!");
6930	Substitutions[Ptr] = SeqID++;
6931	}
6932
6933	void CXXNameMangler::extendSubstitutions(CXXNameMangler* Other) {
6934	assert(Other->SeqID >= SeqID && "Must be superset of substitutions!");
6935	if (Other->SeqID > SeqID) {
6936	Substitutions.swap(RHS&: Other->Substitutions);
6937	SeqID = Other->SeqID;
6938	}
6939	}
6940
6941	CXXNameMangler::AbiTagList
6942	CXXNameMangler::makeFunctionReturnTypeTags(const FunctionDecl *FD) {
6943	// When derived abi tags are disabled there is no need to make any list.
6944	if (DisableDerivedAbiTags)
6945	return AbiTagList();
6946
6947	llvm::raw_null_ostream NullOutStream;
6948	CXXNameMangler TrackReturnTypeTags(*this, NullOutStream);
6949	TrackReturnTypeTags.disableDerivedAbiTags();
6950
6951	const FunctionProtoType *Proto =
6952	cast<FunctionProtoType>(FD->getType()->getAs<FunctionType>());
6953	FunctionTypeDepthState saved = TrackReturnTypeTags.FunctionTypeDepth.push();
6954	TrackReturnTypeTags.FunctionTypeDepth.enterResultType();
6955	TrackReturnTypeTags.mangleType(Proto->getReturnType());
6956	TrackReturnTypeTags.FunctionTypeDepth.leaveResultType();
6957	TrackReturnTypeTags.FunctionTypeDepth.pop(saved);
6958
6959	return TrackReturnTypeTags.AbiTagsRoot.getSortedUniqueUsedAbiTags();
6960	}
6961
6962	CXXNameMangler::AbiTagList
6963	CXXNameMangler::makeVariableTypeTags(const VarDecl *VD) {
6964	// When derived abi tags are disabled there is no need to make any list.
6965	if (DisableDerivedAbiTags)
6966	return AbiTagList();
6967
6968	llvm::raw_null_ostream NullOutStream;
6969	CXXNameMangler TrackVariableType(*this, NullOutStream);
6970	TrackVariableType.disableDerivedAbiTags();
6971
6972	TrackVariableType.mangleType(VD->getType());
6973
6974	return TrackVariableType.AbiTagsRoot.getSortedUniqueUsedAbiTags();
6975	}
6976
6977	bool CXXNameMangler::shouldHaveAbiTags(ItaniumMangleContextImpl &C,
6978	const VarDecl *VD) {
6979	llvm::raw_null_ostream NullOutStream;
6980	CXXNameMangler TrackAbiTags(C, NullOutStream, nullptr, true);
6981	TrackAbiTags.mangle(GD: VD);
6982	return TrackAbiTags.AbiTagsRoot.getUsedAbiTags().size();
6983	}
6984
6985	//
6986
6987	/// Mangles the name of the declaration D and emits that name to the given
6988	/// output stream.
6989	///
6990	/// If the declaration D requires a mangled name, this routine will emit that
6991	/// mangled name to \p os and return true. Otherwise, \p os will be unchanged
6992	/// and this routine will return false. In this case, the caller should just
6993	/// emit the identifier of the declaration (\c D->getIdentifier()) as its
6994	/// name.
6995	void ItaniumMangleContextImpl::mangleCXXName(GlobalDecl GD,
6996	raw_ostream &Out) {
6997	const NamedDecl *D = cast<NamedDecl>(Val: GD.getDecl());
6998	assert((isa<FunctionDecl, VarDecl, TemplateParamObjectDecl>(D)) &&
6999	"Invalid mangleName() call, argument is not a variable or function!");
7000
7001	PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
7002	getASTContext().getSourceManager(),
7003	"Mangling declaration");
7004
7005	if (auto *CD = dyn_cast<CXXConstructorDecl>(Val: D)) {
7006	auto Type = GD.getCtorType();
7007	CXXNameMangler Mangler(*this, Out, CD, Type);
7008	return Mangler.mangle(GD: GlobalDecl(CD, Type));
7009	}
7010
7011	if (auto *DD = dyn_cast<CXXDestructorDecl>(Val: D)) {
7012	auto Type = GD.getDtorType();
7013	CXXNameMangler Mangler(*this, Out, DD, Type);
7014	return Mangler.mangle(GD: GlobalDecl(DD, Type));
7015	}
7016
7017	CXXNameMangler Mangler(*this, Out, D);
7018	Mangler.mangle(GD);
7019	}
7020
7021	void ItaniumMangleContextImpl::mangleCXXCtorComdat(const CXXConstructorDecl *D,
7022	raw_ostream &Out) {
7023	CXXNameMangler Mangler(*this, Out, D, Ctor_Comdat);
7024	Mangler.mangle(GD: GlobalDecl(D, Ctor_Comdat));
7025	}
7026
7027	void ItaniumMangleContextImpl::mangleCXXDtorComdat(const CXXDestructorDecl *D,
7028	raw_ostream &Out) {
7029	CXXNameMangler Mangler(*this, Out, D, Dtor_Comdat);
7030	Mangler.mangle(GD: GlobalDecl(D, Dtor_Comdat));
7031	}
7032
7033	void ItaniumMangleContextImpl::mangleThunk(const CXXMethodDecl *MD,
7034	const ThunkInfo &Thunk,
7035	raw_ostream &Out) {
7036	// <special-name> ::= T <call-offset> <base encoding>
7037	// # base is the nominal target function of thunk
7038	// <special-name> ::= Tc <call-offset> <call-offset> <base encoding>
7039	// # base is the nominal target function of thunk
7040	// # first call-offset is 'this' adjustment
7041	// # second call-offset is result adjustment
7042
7043	assert(!isa<CXXDestructorDecl>(MD) &&
7044	"Use mangleCXXDtor for destructor decls!");
7045	CXXNameMangler Mangler(*this, Out);
7046	Mangler.getStream() << "_ZT";
7047	if (!Thunk.Return.isEmpty())
7048	Mangler.getStream() << 'c';
7049
7050	// Mangle the 'this' pointer adjustment.
7051	Mangler.mangleCallOffset(NonVirtual: Thunk.This.NonVirtual,
7052	Virtual: Thunk.This.Virtual.Itanium.VCallOffsetOffset);
7053
7054	// Mangle the return pointer adjustment if there is one.
7055	if (!Thunk.Return.isEmpty())
7056	Mangler.mangleCallOffset(NonVirtual: Thunk.Return.NonVirtual,
7057	Virtual: Thunk.Return.Virtual.Itanium.VBaseOffsetOffset);
7058
7059	Mangler.mangleFunctionEncoding(MD);
7060	}
7061
7062	void ItaniumMangleContextImpl::mangleCXXDtorThunk(
7063	const CXXDestructorDecl *DD, CXXDtorType Type,
7064	const ThisAdjustment &ThisAdjustment, raw_ostream &Out) {
7065	// <special-name> ::= T <call-offset> <base encoding>
7066	// # base is the nominal target function of thunk
7067	CXXNameMangler Mangler(*this, Out, DD, Type);
7068	Mangler.getStream() << "_ZT";
7069
7070	// Mangle the 'this' pointer adjustment.
7071	Mangler.mangleCallOffset(NonVirtual: ThisAdjustment.NonVirtual,
7072	Virtual: ThisAdjustment.Virtual.Itanium.VCallOffsetOffset);
7073
7074	Mangler.mangleFunctionEncoding(GD: GlobalDecl(DD, Type));
7075	}
7076
7077	/// Returns the mangled name for a guard variable for the passed in VarDecl.
7078	void ItaniumMangleContextImpl::mangleStaticGuardVariable(const VarDecl *D,
7079	raw_ostream &Out) {
7080	// <special-name> ::= GV <object name> # Guard variable for one-time
7081	// # initialization
7082	CXXNameMangler Mangler(*this, Out);
7083	// GCC 5.3.0 doesn't emit derived ABI tags for local names but that seems to
7084	// be a bug that is fixed in trunk.
7085	Mangler.getStream() << "_ZGV";
7086	Mangler.mangleName(GD: D);
7087	}
7088
7089	void ItaniumMangleContextImpl::mangleDynamicInitializer(const VarDecl *MD,
7090	raw_ostream &Out) {
7091	// These symbols are internal in the Itanium ABI, so the names don't matter.
7092	// Clang has traditionally used this symbol and allowed LLVM to adjust it to
7093	// avoid duplicate symbols.
7094	Out << "__cxx_global_var_init";
7095	}
7096
7097	void ItaniumMangleContextImpl::mangleDynamicAtExitDestructor(const VarDecl *D,
7098	raw_ostream &Out) {
7099	// Prefix the mangling of D with __dtor_.
7100	CXXNameMangler Mangler(*this, Out);
7101	Mangler.getStream() << "__dtor_";
7102	if (shouldMangleDeclName(D))
7103	Mangler.mangle(GD: D);
7104	else
7105	Mangler.getStream() << D->getName();
7106	}
7107
7108	void ItaniumMangleContextImpl::mangleDynamicStermFinalizer(const VarDecl *D,
7109	raw_ostream &Out) {
7110	// Clang generates these internal-linkage functions as part of its
7111	// implementation of the XL ABI.
7112	CXXNameMangler Mangler(*this, Out);
7113	Mangler.getStream() << "__finalize_";
7114	if (shouldMangleDeclName(D))
7115	Mangler.mangle(GD: D);
7116	else
7117	Mangler.getStream() << D->getName();
7118	}
7119
7120	void ItaniumMangleContextImpl::mangleSEHFilterExpression(
7121	GlobalDecl EnclosingDecl, raw_ostream &Out) {
7122	CXXNameMangler Mangler(*this, Out);
7123	Mangler.getStream() << "__filt_";
7124	auto *EnclosingFD = cast<FunctionDecl>(Val: EnclosingDecl.getDecl());
7125	if (shouldMangleDeclName(EnclosingFD))
7126	Mangler.mangle(GD: EnclosingDecl);
7127	else
7128	Mangler.getStream() << EnclosingFD->getName();
7129	}
7130
7131	void ItaniumMangleContextImpl::mangleSEHFinallyBlock(
7132	GlobalDecl EnclosingDecl, raw_ostream &Out) {
7133	CXXNameMangler Mangler(*this, Out);
7134	Mangler.getStream() << "__fin_";
7135	auto *EnclosingFD = cast<FunctionDecl>(Val: EnclosingDecl.getDecl());
7136	if (shouldMangleDeclName(EnclosingFD))
7137	Mangler.mangle(GD: EnclosingDecl);
7138	else
7139	Mangler.getStream() << EnclosingFD->getName();
7140	}
7141
7142	void ItaniumMangleContextImpl::mangleItaniumThreadLocalInit(const VarDecl *D,
7143	raw_ostream &Out) {
7144	// <special-name> ::= TH <object name>
7145	CXXNameMangler Mangler(*this, Out);
7146	Mangler.getStream() << "_ZTH";
7147	Mangler.mangleName(GD: D);
7148	}
7149
7150	void
7151	ItaniumMangleContextImpl::mangleItaniumThreadLocalWrapper(const VarDecl *D,
7152	raw_ostream &Out) {
7153	// <special-name> ::= TW <object name>
7154	CXXNameMangler Mangler(*this, Out);
7155	Mangler.getStream() << "_ZTW";
7156	Mangler.mangleName(GD: D);
7157	}
7158
7159	void ItaniumMangleContextImpl::mangleReferenceTemporary(const VarDecl *D,
7160	unsigned ManglingNumber,
7161	raw_ostream &Out) {
7162	// We match the GCC mangling here.
7163	// <special-name> ::= GR <object name>
7164	CXXNameMangler Mangler(*this, Out);
7165	Mangler.getStream() << "_ZGR";
7166	Mangler.mangleName(GD: D);
7167	assert(ManglingNumber > 0 && "Reference temporary mangling number is zero!");
7168	Mangler.mangleSeqID(SeqID: ManglingNumber - 1);
7169	}
7170
7171	void ItaniumMangleContextImpl::mangleCXXVTable(const CXXRecordDecl *RD,
7172	raw_ostream &Out) {
7173	// <special-name> ::= TV <type> # virtual table
7174	CXXNameMangler Mangler(*this, Out);
7175	Mangler.getStream() << "_ZTV";
7176	Mangler.mangleNameOrStandardSubstitution(RD);
7177	}
7178
7179	void ItaniumMangleContextImpl::mangleCXXVTT(const CXXRecordDecl *RD,
7180	raw_ostream &Out) {
7181	// <special-name> ::= TT <type> # VTT structure
7182	CXXNameMangler Mangler(*this, Out);
7183	Mangler.getStream() << "_ZTT";
7184	Mangler.mangleNameOrStandardSubstitution(RD);
7185	}
7186
7187	void ItaniumMangleContextImpl::mangleCXXCtorVTable(const CXXRecordDecl *RD,
7188	int64_t Offset,
7189	const CXXRecordDecl *Type,
7190	raw_ostream &Out) {
7191	// <special-name> ::= TC <type> <offset number> _ <base type>
7192	CXXNameMangler Mangler(*this, Out);
7193	Mangler.getStream() << "_ZTC";
7194	Mangler.mangleNameOrStandardSubstitution(RD);
7195	Mangler.getStream() << Offset;
7196	Mangler.getStream() << '_';
7197	Mangler.mangleNameOrStandardSubstitution(Type);
7198	}
7199
7200	void ItaniumMangleContextImpl::mangleCXXRTTI(QualType Ty, raw_ostream &Out) {
7201	// <special-name> ::= TI <type> # typeinfo structure
7202	assert(!Ty.hasQualifiers() && "RTTI info cannot have top-level qualifiers");
7203	CXXNameMangler Mangler(*this, Out);
7204	Mangler.getStream() << "_ZTI";
7205	Mangler.mangleType(T: Ty);
7206	}
7207
7208	void ItaniumMangleContextImpl::mangleCXXRTTIName(
7209	QualType Ty, raw_ostream &Out, bool NormalizeIntegers = false) {
7210	// <special-name> ::= TS <type> # typeinfo name (null terminated byte string)
7211	CXXNameMangler Mangler(*this, Out, NormalizeIntegers);
7212	Mangler.getStream() << "_ZTS";
7213	Mangler.mangleType(T: Ty);
7214	}
7215
7216	void ItaniumMangleContextImpl::mangleCanonicalTypeName(
7217	QualType Ty, raw_ostream &Out, bool NormalizeIntegers = false) {
7218	mangleCXXRTTIName(Ty, Out, NormalizeIntegers);
7219	}
7220
7221	void ItaniumMangleContextImpl::mangleStringLiteral(const StringLiteral *, raw_ostream &) {
7222	llvm_unreachable("Can't mangle string literals");
7223	}
7224
7225	void ItaniumMangleContextImpl::mangleLambdaSig(const CXXRecordDecl *Lambda,
7226	raw_ostream &Out) {
7227	CXXNameMangler Mangler(*this, Out);
7228	Mangler.mangleLambdaSig(Lambda);
7229	}
7230
7231	void ItaniumMangleContextImpl::mangleModuleInitializer(const Module *M,
7232	raw_ostream &Out) {
7233	// <special-name> ::= GI <module-name> # module initializer function
7234	CXXNameMangler Mangler(*this, Out);
7235	Mangler.getStream() << "_ZGI";
7236	Mangler.mangleModuleNamePrefix(Name: M->getPrimaryModuleInterfaceName());
7237	if (M->isModulePartition()) {
7238	// The partition needs including, as partitions can have them too.
7239	auto Partition = M->Name.find(c: ':');
7240	Mangler.mangleModuleNamePrefix(
7241	Name: StringRef(&M->Name[Partition + 1], M->Name.size() - Partition - 1),
7242	/*IsPartition*/ true);
7243	}
7244	}
7245
7246	ItaniumMangleContext *ItaniumMangleContext::create(ASTContext &Context,
7247	DiagnosticsEngine &Diags,
7248	bool IsAux) {
7249	return new ItaniumMangleContextImpl(
7250	Context, Diags,
7251	[](ASTContext &, const NamedDecl *) -> std::optional<unsigned> {
7252	return std::nullopt;
7253	},
7254	IsAux);
7255	}
7256
7257	ItaniumMangleContext *
7258	ItaniumMangleContext::create(ASTContext &Context, DiagnosticsEngine &Diags,
7259	DiscriminatorOverrideTy DiscriminatorOverride,
7260	bool IsAux) {
7261	return new ItaniumMangleContextImpl(Context, Diags, DiscriminatorOverride,
7262	IsAux);
7263	}
7264