1//===------- QualTypeNames.cpp - Generate Complete QualType Names ---------===//
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#include "clang/AST/QualTypeNames.h"
10#include "clang/AST/DeclTemplate.h"
11#include "clang/AST/DeclarationName.h"
12#include "clang/AST/Mangle.h"
13#include "clang/AST/Type.h"
14
15namespace clang {
16
17namespace TypeName {
18
19/// Create a NestedNameSpecifier for Namesp and its enclosing
20/// scopes.
21///
22/// \param[in] Ctx - the AST Context to be used.
23/// \param[in] Namesp - the NamespaceDecl for which a NestedNameSpecifier
24/// is requested.
25/// \param[in] WithGlobalNsPrefix - Indicate whether the global namespace
26/// specifier "::" should be prepended or not.
27static NestedNameSpecifier *createNestedNameSpecifier(
28 const ASTContext &Ctx,
29 const NamespaceDecl *Namesp,
30 bool WithGlobalNsPrefix);
31
32/// Create a NestedNameSpecifier for TagDecl and its enclosing
33/// scopes.
34///
35/// \param[in] Ctx - the AST Context to be used.
36/// \param[in] TD - the TagDecl for which a NestedNameSpecifier is
37/// requested.
38/// \param[in] FullyQualify - Convert all template arguments into fully
39/// qualified names.
40/// \param[in] WithGlobalNsPrefix - Indicate whether the global namespace
41/// specifier "::" should be prepended or not.
42static NestedNameSpecifier *createNestedNameSpecifier(
43 const ASTContext &Ctx, const TypeDecl *TD,
44 bool FullyQualify, bool WithGlobalNsPrefix);
45
46static NestedNameSpecifier *createNestedNameSpecifierForScopeOf(
47 const ASTContext &Ctx, const Decl *decl,
48 bool FullyQualified, bool WithGlobalNsPrefix);
49
50static NestedNameSpecifier *getFullyQualifiedNestedNameSpecifier(
51 const ASTContext &Ctx, NestedNameSpecifier *scope, bool WithGlobalNsPrefix);
52
53static bool getFullyQualifiedTemplateName(const ASTContext &Ctx,
54 TemplateName &TName,
55 bool WithGlobalNsPrefix) {
56 bool Changed = false;
57 NestedNameSpecifier *NNS = nullptr;
58
59 TemplateDecl *ArgTDecl = TName.getAsTemplateDecl();
60 // ArgTDecl won't be NULL because we asserted that this isn't a
61 // dependent context very early in the call chain.
62 assert(ArgTDecl != nullptr);
63 QualifiedTemplateName *QTName = TName.getAsQualifiedTemplateName();
64
65 if (QTName &&
66 !QTName->hasTemplateKeyword() &&
67 (NNS = QTName->getQualifier())) {
68 NestedNameSpecifier *QNNS = getFullyQualifiedNestedNameSpecifier(
69 Ctx, scope: NNS, WithGlobalNsPrefix);
70 if (QNNS != NNS) {
71 Changed = true;
72 NNS = QNNS;
73 } else {
74 NNS = nullptr;
75 }
76 } else {
77 NNS = createNestedNameSpecifierForScopeOf(
78 Ctx, decl: ArgTDecl, FullyQualified: true, WithGlobalNsPrefix);
79 }
80 if (NNS) {
81 TemplateName UnderlyingTN(ArgTDecl);
82 if (UsingShadowDecl *USD = TName.getAsUsingShadowDecl())
83 UnderlyingTN = TemplateName(USD);
84 TName =
85 Ctx.getQualifiedTemplateName(NNS,
86 /*TemplateKeyword=*/false, Template: UnderlyingTN);
87 Changed = true;
88 }
89 return Changed;
90}
91
92static bool getFullyQualifiedTemplateArgument(const ASTContext &Ctx,
93 TemplateArgument &Arg,
94 bool WithGlobalNsPrefix) {
95 bool Changed = false;
96
97 // Note: we do not handle TemplateArgument::Expression, to replace it
98 // we need the information for the template instance decl.
99
100 if (Arg.getKind() == TemplateArgument::Template) {
101 TemplateName TName = Arg.getAsTemplate();
102 Changed = getFullyQualifiedTemplateName(Ctx, TName, WithGlobalNsPrefix);
103 if (Changed) {
104 Arg = TemplateArgument(TName);
105 }
106 } else if (Arg.getKind() == TemplateArgument::Type) {
107 QualType SubTy = Arg.getAsType();
108 // Check if the type needs more desugaring and recurse.
109 QualType QTFQ = getFullyQualifiedType(QT: SubTy, Ctx, WithGlobalNsPrefix);
110 if (QTFQ != SubTy) {
111 Arg = TemplateArgument(QTFQ);
112 Changed = true;
113 }
114 }
115 return Changed;
116}
117
118static const Type *getFullyQualifiedTemplateType(const ASTContext &Ctx,
119 const Type *TypePtr,
120 bool WithGlobalNsPrefix) {
121 // DependentTemplateTypes exist within template declarations and
122 // definitions. Therefore we shouldn't encounter them at the end of
123 // a translation unit. If we do, the caller has made an error.
124 assert(!isa<DependentTemplateSpecializationType>(TypePtr));
125 // In case of template specializations, iterate over the arguments
126 // and fully qualify them as well.
127 if (const auto *TST = dyn_cast<const TemplateSpecializationType>(Val: TypePtr)) {
128 bool MightHaveChanged = false;
129 SmallVector<TemplateArgument, 4> FQArgs;
130 // Cheap to copy and potentially modified by
131 // getFullyQualifedTemplateArgument.
132 for (TemplateArgument Arg : TST->template_arguments()) {
133 MightHaveChanged |= getFullyQualifiedTemplateArgument(
134 Ctx, Arg, WithGlobalNsPrefix);
135 FQArgs.push_back(Elt: Arg);
136 }
137
138 // If a fully qualified arg is different from the unqualified arg,
139 // allocate new type in the AST.
140 if (MightHaveChanged) {
141 QualType QT = Ctx.getTemplateSpecializationType(
142 T: TST->getTemplateName(), SpecifiedArgs: FQArgs,
143 /*CanonicalArgs=*/{}, Underlying: TST->desugar());
144 // getTemplateSpecializationType returns a fully qualified
145 // version of the specialization itself, so no need to qualify
146 // it.
147 return QT.getTypePtr();
148 }
149 } else if (const auto *TSTRecord = dyn_cast<const RecordType>(Val: TypePtr)) {
150 // We are asked to fully qualify and we have a Record Type,
151 // which can point to a template instantiation with no sugar in any of
152 // its template argument, however we still need to fully qualify them.
153
154 if (const auto *TSTDecl =
155 dyn_cast<ClassTemplateSpecializationDecl>(Val: TSTRecord->getDecl())) {
156 const TemplateArgumentList &TemplateArgs = TSTDecl->getTemplateArgs();
157
158 bool MightHaveChanged = false;
159 SmallVector<TemplateArgument, 4> FQArgs;
160 for (unsigned int I = 0, E = TemplateArgs.size(); I != E; ++I) {
161 // cheap to copy and potentially modified by
162 // getFullyQualifedTemplateArgument
163 TemplateArgument Arg(TemplateArgs[I]);
164 MightHaveChanged |= getFullyQualifiedTemplateArgument(
165 Ctx, Arg, WithGlobalNsPrefix);
166 FQArgs.push_back(Elt: Arg);
167 }
168
169 // If a fully qualified arg is different from the unqualified arg,
170 // allocate new type in the AST.
171 if (MightHaveChanged) {
172 TemplateName TN(TSTDecl->getSpecializedTemplate());
173 QualType QT = Ctx.getTemplateSpecializationType(
174 T: TN, SpecifiedArgs: FQArgs,
175 /*CanonicalArgs=*/{}, Underlying: TSTRecord->getCanonicalTypeInternal());
176 // getTemplateSpecializationType returns a fully qualified
177 // version of the specialization itself, so no need to qualify
178 // it.
179 return QT.getTypePtr();
180 }
181 }
182 }
183 return TypePtr;
184}
185
186static NestedNameSpecifier *createOuterNNS(const ASTContext &Ctx, const Decl *D,
187 bool FullyQualify,
188 bool WithGlobalNsPrefix) {
189 const DeclContext *DC = D->getDeclContext();
190 if (const auto *NS = dyn_cast<NamespaceDecl>(Val: DC)) {
191 while (NS && NS->isInline()) {
192 // Ignore inline namespace;
193 NS = dyn_cast<NamespaceDecl>(Val: NS->getDeclContext());
194 }
195 if (NS && NS->getDeclName()) {
196 return createNestedNameSpecifier(Ctx, Namesp: NS, WithGlobalNsPrefix);
197 }
198 return nullptr; // no starting '::', no anonymous
199 } else if (const auto *TD = dyn_cast<TagDecl>(Val: DC)) {
200 return createNestedNameSpecifier(Ctx, TD, FullyQualify, WithGlobalNsPrefix);
201 } else if (const auto *TDD = dyn_cast<TypedefNameDecl>(Val: DC)) {
202 return createNestedNameSpecifier(
203 Ctx, TD: TDD, FullyQualify, WithGlobalNsPrefix);
204 } else if (WithGlobalNsPrefix && DC->isTranslationUnit()) {
205 return NestedNameSpecifier::GlobalSpecifier(Context: Ctx);
206 }
207 return nullptr; // no starting '::' if |WithGlobalNsPrefix| is false
208}
209
210/// Return a fully qualified version of this name specifier.
211static NestedNameSpecifier *getFullyQualifiedNestedNameSpecifier(
212 const ASTContext &Ctx, NestedNameSpecifier *Scope,
213 bool WithGlobalNsPrefix) {
214 switch (Scope->getKind()) {
215 case NestedNameSpecifier::Global:
216 case NestedNameSpecifier::Super:
217 // Already fully qualified
218 return Scope;
219 case NestedNameSpecifier::Namespace:
220 return TypeName::createNestedNameSpecifier(
221 Ctx, Namesp: Scope->getAsNamespace(), WithGlobalNsPrefix);
222 case NestedNameSpecifier::NamespaceAlias:
223 // Namespace aliases are only valid for the duration of the
224 // scope where they were introduced, and therefore are often
225 // invalid at the end of the TU. So use the namespace name more
226 // likely to be valid at the end of the TU.
227 return TypeName::createNestedNameSpecifier(
228 Ctx,
229 Namesp: Scope->getAsNamespaceAlias()->getNamespace()->getCanonicalDecl(),
230 WithGlobalNsPrefix);
231 case NestedNameSpecifier::Identifier:
232 // A function or some other construct that makes it un-namable
233 // at the end of the TU. Skip the current component of the name,
234 // but use the name of it's prefix.
235 return getFullyQualifiedNestedNameSpecifier(
236 Ctx, Scope: Scope->getPrefix(), WithGlobalNsPrefix);
237 case NestedNameSpecifier::TypeSpec: {
238 const Type *Type = Scope->getAsType();
239 // Find decl context.
240 const TagDecl *TD = nullptr;
241 if (const TagType *TagDeclType = Type->getAs<TagType>()) {
242 TD = TagDeclType->getDecl();
243 } else {
244 TD = Type->getAsCXXRecordDecl();
245 }
246 if (TD) {
247 return TypeName::createNestedNameSpecifier(Ctx, TD,
248 FullyQualify: true /*FullyQualified*/,
249 WithGlobalNsPrefix);
250 } else if (const auto *TDD = dyn_cast<TypedefType>(Val: Type)) {
251 return TypeName::createNestedNameSpecifier(Ctx, TD: TDD->getDecl(),
252 FullyQualify: true /*FullyQualified*/,
253 WithGlobalNsPrefix);
254 }
255 return Scope;
256 }
257 }
258 llvm_unreachable("bad NNS kind");
259}
260
261/// Create a nested name specifier for the declaring context of
262/// the type.
263static NestedNameSpecifier *createNestedNameSpecifierForScopeOf(
264 const ASTContext &Ctx, const Decl *Decl,
265 bool FullyQualified, bool WithGlobalNsPrefix) {
266 assert(Decl);
267
268 const DeclContext *DC = Decl->getDeclContext()->getRedeclContext();
269 const auto *Outer = dyn_cast<NamedDecl>(Val: DC);
270 const auto *OuterNS = dyn_cast<NamespaceDecl>(Val: DC);
271 if (Outer && !(OuterNS && OuterNS->isAnonymousNamespace())) {
272 if (const auto *CxxDecl = dyn_cast<CXXRecordDecl>(Val: DC)) {
273 if (ClassTemplateDecl *ClassTempl =
274 CxxDecl->getDescribedClassTemplate()) {
275 // We are in the case of a type(def) that was declared in a
276 // class template but is *not* type dependent. In clang, it
277 // gets attached to the class template declaration rather than
278 // any specific class template instantiation. This result in
279 // 'odd' fully qualified typename:
280 //
281 // vector<_Tp,_Alloc>::size_type
282 //
283 // Make the situation is 'useable' but looking a bit odd by
284 // picking a random instance as the declaring context.
285 if (ClassTempl->spec_begin() != ClassTempl->spec_end()) {
286 Decl = *(ClassTempl->spec_begin());
287 Outer = dyn_cast<NamedDecl>(Val: Decl);
288 OuterNS = dyn_cast<NamespaceDecl>(Val: Decl);
289 }
290 }
291 }
292
293 if (OuterNS) {
294 return createNestedNameSpecifier(Ctx, Namesp: OuterNS, WithGlobalNsPrefix);
295 } else if (const auto *TD = dyn_cast<TagDecl>(Val: Outer)) {
296 return createNestedNameSpecifier(
297 Ctx, TD, FullyQualify: FullyQualified, WithGlobalNsPrefix);
298 } else if (isa<TranslationUnitDecl>(Val: Outer)) {
299 // Context is the TU. Nothing needs to be done.
300 return nullptr;
301 } else {
302 // Decl's context was neither the TU, a namespace, nor a
303 // TagDecl, which means it is a type local to a scope, and not
304 // accessible at the end of the TU.
305 return nullptr;
306 }
307 } else if (WithGlobalNsPrefix && DC->isTranslationUnit()) {
308 return NestedNameSpecifier::GlobalSpecifier(Context: Ctx);
309 }
310 return nullptr;
311}
312
313/// Create a nested name specifier for the declaring context of
314/// the type.
315static NestedNameSpecifier *createNestedNameSpecifierForScopeOf(
316 const ASTContext &Ctx, const Type *TypePtr,
317 bool FullyQualified, bool WithGlobalNsPrefix) {
318 if (!TypePtr) return nullptr;
319
320 Decl *Decl = nullptr;
321 // There are probably other cases ...
322 if (const auto *TDT = dyn_cast<TypedefType>(Val: TypePtr)) {
323 Decl = TDT->getDecl();
324 } else if (const auto *TagDeclType = dyn_cast<TagType>(Val: TypePtr)) {
325 Decl = TagDeclType->getDecl();
326 } else if (const auto *TST = dyn_cast<TemplateSpecializationType>(Val: TypePtr)) {
327 Decl = TST->getTemplateName().getAsTemplateDecl();
328 } else {
329 Decl = TypePtr->getAsCXXRecordDecl();
330 }
331
332 if (!Decl) return nullptr;
333
334 return createNestedNameSpecifierForScopeOf(
335 Ctx, Decl, FullyQualified, WithGlobalNsPrefix);
336}
337
338NestedNameSpecifier *createNestedNameSpecifier(const ASTContext &Ctx,
339 const NamespaceDecl *Namespace,
340 bool WithGlobalNsPrefix) {
341 while (Namespace && Namespace->isInline()) {
342 // Ignore inline namespace;
343 Namespace = dyn_cast<NamespaceDecl>(Val: Namespace->getDeclContext());
344 }
345 if (!Namespace) return nullptr;
346
347 bool FullyQualified = true; // doesn't matter, DeclContexts are namespaces
348 return NestedNameSpecifier::Create(
349 Context: Ctx,
350 Prefix: createOuterNNS(Ctx, D: Namespace, FullyQualify: FullyQualified, WithGlobalNsPrefix),
351 NS: Namespace);
352}
353
354NestedNameSpecifier *createNestedNameSpecifier(const ASTContext &Ctx,
355 const TypeDecl *TD,
356 bool FullyQualify,
357 bool WithGlobalNsPrefix) {
358 const Type *TypePtr = TD->getTypeForDecl();
359 if (isa<const TemplateSpecializationType>(Val: TypePtr) ||
360 isa<const RecordType>(Val: TypePtr)) {
361 // We are asked to fully qualify and we have a Record Type (which
362 // may point to a template specialization) or Template
363 // Specialization Type. We need to fully qualify their arguments.
364
365 TypePtr = getFullyQualifiedTemplateType(Ctx, TypePtr, WithGlobalNsPrefix);
366 }
367
368 return NestedNameSpecifier::Create(
369 Context: Ctx, Prefix: createOuterNNS(Ctx, D: TD, FullyQualify, WithGlobalNsPrefix), T: TypePtr);
370}
371
372/// Return the fully qualified type, including fully-qualified
373/// versions of any template parameters.
374QualType getFullyQualifiedType(QualType QT, const ASTContext &Ctx,
375 bool WithGlobalNsPrefix) {
376 // In case of myType* we need to strip the pointer first, fully
377 // qualify and attach the pointer once again.
378 if (isa<PointerType>(Val: QT.getTypePtr())) {
379 // Get the qualifiers.
380 Qualifiers Quals = QT.getQualifiers();
381 QT = getFullyQualifiedType(QT: QT->getPointeeType(), Ctx, WithGlobalNsPrefix);
382 QT = Ctx.getPointerType(T: QT);
383 // Add back the qualifiers.
384 QT = Ctx.getQualifiedType(T: QT, Qs: Quals);
385 return QT;
386 }
387
388 if (auto *MPT = dyn_cast<MemberPointerType>(Val: QT.getTypePtr())) {
389 // Get the qualifiers.
390 Qualifiers Quals = QT.getQualifiers();
391 // Fully qualify the pointee and class types.
392 QT = getFullyQualifiedType(QT: QT->getPointeeType(), Ctx, WithGlobalNsPrefix);
393 NestedNameSpecifier *Qualifier = getFullyQualifiedNestedNameSpecifier(
394 Ctx, Scope: MPT->getQualifier(), WithGlobalNsPrefix);
395 QT = Ctx.getMemberPointerType(T: QT, Qualifier,
396 Cls: MPT->getMostRecentCXXRecordDecl());
397 // Add back the qualifiers.
398 QT = Ctx.getQualifiedType(T: QT, Qs: Quals);
399 return QT;
400 }
401
402 // In case of myType& we need to strip the reference first, fully
403 // qualify and attach the reference once again.
404 if (isa<ReferenceType>(Val: QT.getTypePtr())) {
405 // Get the qualifiers.
406 bool IsLValueRefTy = isa<LValueReferenceType>(Val: QT.getTypePtr());
407 Qualifiers Quals = QT.getQualifiers();
408 QT = getFullyQualifiedType(QT: QT->getPointeeType(), Ctx, WithGlobalNsPrefix);
409 // Add the r- or l-value reference type back to the fully
410 // qualified one.
411 if (IsLValueRefTy)
412 QT = Ctx.getLValueReferenceType(T: QT);
413 else
414 QT = Ctx.getRValueReferenceType(T: QT);
415 // Add back the qualifiers.
416 QT = Ctx.getQualifiedType(T: QT, Qs: Quals);
417 return QT;
418 }
419
420 // Handle types with attributes such as `unique_ptr<int> _Nonnull`.
421 if (auto *AT = dyn_cast<AttributedType>(Val: QT.getTypePtr())) {
422 QualType NewModified =
423 getFullyQualifiedType(QT: AT->getModifiedType(), Ctx, WithGlobalNsPrefix);
424 QualType NewEquivalent =
425 getFullyQualifiedType(QT: AT->getEquivalentType(), Ctx, WithGlobalNsPrefix);
426 Qualifiers Qualifiers = QT.getLocalQualifiers();
427 return Ctx.getQualifiedType(
428 T: Ctx.getAttributedType(attrKind: AT->getAttrKind(), modifiedType: NewModified, equivalentType: NewEquivalent),
429 Qs: Qualifiers);
430 }
431
432 // Remove the part of the type related to the type being a template
433 // parameter (we won't report it as part of the 'type name' and it
434 // is actually make the code below to be more complex (to handle
435 // those)
436 while (isa<SubstTemplateTypeParmType>(Val: QT.getTypePtr())) {
437 // Get the qualifiers.
438 Qualifiers Quals = QT.getQualifiers();
439
440 QT = cast<SubstTemplateTypeParmType>(Val: QT.getTypePtr())->desugar();
441
442 // Add back the qualifiers.
443 QT = Ctx.getQualifiedType(T: QT, Qs: Quals);
444 }
445
446 NestedNameSpecifier *Prefix = nullptr;
447 // Local qualifiers are attached to the QualType outside of the
448 // elaborated type. Retrieve them before descending into the
449 // elaborated type.
450 Qualifiers PrefixQualifiers = QT.getLocalQualifiers();
451 QT = QualType(QT.getTypePtr(), 0);
452 ElaboratedTypeKeyword Keyword = ElaboratedTypeKeyword::None;
453 if (const auto *ETypeInput = dyn_cast<ElaboratedType>(Val: QT.getTypePtr())) {
454 QT = ETypeInput->getNamedType();
455 assert(!QT.hasLocalQualifiers());
456 Keyword = ETypeInput->getKeyword();
457 }
458
459 // We don't consider the alias introduced by `using a::X` as a new type.
460 // The qualified name is still a::X.
461 if (const auto *UT = QT->getAs<UsingType>()) {
462 QT = Ctx.getQualifiedType(T: UT->getUnderlyingType(), Qs: PrefixQualifiers);
463 return getFullyQualifiedType(QT, Ctx, WithGlobalNsPrefix);
464 }
465
466 // Create a nested name specifier if needed.
467 Prefix = createNestedNameSpecifierForScopeOf(Ctx, TypePtr: QT.getTypePtr(),
468 FullyQualified: true /*FullyQualified*/,
469 WithGlobalNsPrefix);
470
471 // In case of template specializations iterate over the arguments and
472 // fully qualify them as well.
473 if (isa<const TemplateSpecializationType>(Val: QT.getTypePtr()) ||
474 isa<const RecordType>(Val: QT.getTypePtr())) {
475 // We are asked to fully qualify and we have a Record Type (which
476 // may point to a template specialization) or Template
477 // Specialization Type. We need to fully qualify their arguments.
478
479 const Type *TypePtr = getFullyQualifiedTemplateType(
480 Ctx, TypePtr: QT.getTypePtr(), WithGlobalNsPrefix);
481 QT = QualType(TypePtr, 0);
482 }
483 if (Prefix || Keyword != ElaboratedTypeKeyword::None) {
484 QT = Ctx.getElaboratedType(Keyword, NNS: Prefix, NamedType: QT);
485 }
486 QT = Ctx.getQualifiedType(T: QT, Qs: PrefixQualifiers);
487 return QT;
488}
489
490std::string getFullyQualifiedName(QualType QT,
491 const ASTContext &Ctx,
492 const PrintingPolicy &Policy,
493 bool WithGlobalNsPrefix) {
494 QualType FQQT = getFullyQualifiedType(QT, Ctx, WithGlobalNsPrefix);
495 return FQQT.getAsString(Policy);
496}
497
498} // end namespace TypeName
499} // end namespace clang
500