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

source code of clang/lib/AST/QualTypeNames.cpp