1 //===- NestedNameSpecifier.h - C++ nested name specifiers -------*- C++ -*-===//
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
7 //===----------------------------------------------------------------------===//
9 // This file defines the NestedNameSpecifier class, which represents
10 // a C++ nested-name-specifier.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H
15 #define LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H
17 #include "clang/Basic/Diagnostic.h"
18 #include "clang/Basic/SourceLocation.h"
19 #include "llvm/ADT/FoldingSet.h"
20 #include "llvm/ADT/PointerIntPair.h"
21 #include "llvm/Support/Compiler.h"
32 class NamespaceAliasDecl;
34 struct PrintingPolicy;
38 /// Represents a C++ nested name specifier, such as
39 /// "\::std::vector<int>::".
41 /// C++ nested name specifiers are the prefixes to qualified
42 /// names. For example, "foo::" in "foo::x" is a nested name
43 /// specifier. Nested name specifiers are made up of a sequence of
44 /// specifiers, each of which can be a namespace, type, identifier
45 /// (for dependent names), decltype specifier, or the global specifier ('::').
46 /// The last two specifiers can only appear at the start of a
47 /// nested-namespace-specifier.
48 class NestedNameSpecifier : public llvm::FoldingSetNode {
49 /// Enumeration describing
50 enum StoredSpecifierKind {
54 StoredTypeSpecWithTemplate = 3
57 /// The nested name specifier that precedes this nested name
60 /// The pointer is the nested-name-specifier that precedes this
61 /// one. The integer stores one of the first four values of type
63 llvm::PointerIntPair<NestedNameSpecifier *, 2, StoredSpecifierKind> Prefix;
65 /// The last component in the nested name specifier, which
66 /// can be an identifier, a declaration, or a type.
68 /// When the pointer is NULL, this specifier represents the global
69 /// specifier '::'. Otherwise, the pointer is one of
70 /// IdentifierInfo*, Namespace*, or Type*, depending on the kind of
71 /// specifier as encoded within the prefix.
72 void* Specifier = nullptr;
75 /// The kind of specifier that completes this nested name
78 /// An identifier, stored as an IdentifierInfo*.
81 /// A namespace, stored as a NamespaceDecl*.
84 /// A namespace alias, stored as a NamespaceAliasDecl*.
87 /// A type, stored as a Type*.
90 /// A type that was preceded by the 'template' keyword,
91 /// stored as a Type*.
94 /// The global specifier '::'. There is no stored value.
97 /// Microsoft's '__super' specifier, stored as a CXXRecordDecl* of
98 /// the class it appeared in.
103 /// Builds the global specifier.
104 NestedNameSpecifier() : Prefix(nullptr, StoredIdentifier) {}
106 /// Copy constructor used internally to clone nested name
108 NestedNameSpecifier(const NestedNameSpecifier &Other) = default;
110 /// Either find or insert the given nested name specifier
111 /// mockup in the given context.
112 static NestedNameSpecifier *FindOrInsert(const ASTContext &Context,
113 const NestedNameSpecifier &Mockup);
116 NestedNameSpecifier &operator=(const NestedNameSpecifier &) = delete;
118 /// Builds a specifier combining a prefix and an identifier.
120 /// The prefix must be dependent, since nested name specifiers
121 /// referencing an identifier are only permitted when the identifier
122 /// cannot be resolved.
123 static NestedNameSpecifier *Create(const ASTContext &Context,
124 NestedNameSpecifier *Prefix,
127 /// Builds a nested name specifier that names a namespace.
128 static NestedNameSpecifier *Create(const ASTContext &Context,
129 NestedNameSpecifier *Prefix,
130 const NamespaceDecl *NS);
132 /// Builds a nested name specifier that names a namespace alias.
133 static NestedNameSpecifier *Create(const ASTContext &Context,
134 NestedNameSpecifier *Prefix,
135 NamespaceAliasDecl *Alias);
137 /// Builds a nested name specifier that names a type.
138 static NestedNameSpecifier *Create(const ASTContext &Context,
139 NestedNameSpecifier *Prefix,
140 bool Template, const Type *T);
142 /// Builds a specifier that consists of just an identifier.
144 /// The nested-name-specifier is assumed to be dependent, but has no
145 /// prefix because the prefix is implied by something outside of the
146 /// nested name specifier, e.g., in "x->Base::f", the "x" has a dependent
148 static NestedNameSpecifier *Create(const ASTContext &Context,
151 /// Returns the nested name specifier representing the global
153 static NestedNameSpecifier *GlobalSpecifier(const ASTContext &Context);
155 /// Returns the nested name specifier representing the __super scope
156 /// for the given CXXRecordDecl.
157 static NestedNameSpecifier *SuperSpecifier(const ASTContext &Context,
160 /// Return the prefix of this nested name specifier.
162 /// The prefix contains all of the parts of the nested name
163 /// specifier that preced this current specifier. For example, for a
164 /// nested name specifier that represents "foo::bar::", the current
165 /// specifier will contain "bar::" and the prefix will contain
167 NestedNameSpecifier *getPrefix() const { return Prefix.getPointer(); }
169 /// Determine what kind of nested name specifier is stored.
170 SpecifierKind getKind() const;
172 /// Retrieve the identifier stored in this nested name
174 IdentifierInfo *getAsIdentifier() const {
175 if (Prefix.getInt() == StoredIdentifier)
176 return (IdentifierInfo *)Specifier;
181 /// Retrieve the namespace stored in this nested name
183 NamespaceDecl *getAsNamespace() const;
185 /// Retrieve the namespace alias stored in this nested name
187 NamespaceAliasDecl *getAsNamespaceAlias() const;
189 /// Retrieve the record declaration stored in this nested name
191 CXXRecordDecl *getAsRecordDecl() const;
193 /// Retrieve the type stored in this nested name specifier.
194 const Type *getAsType() const {
195 if (Prefix.getInt() == StoredTypeSpec ||
196 Prefix.getInt() == StoredTypeSpecWithTemplate)
197 return (const Type *)Specifier;
202 /// Whether this nested name specifier refers to a dependent
204 bool isDependent() const;
206 /// Whether this nested name specifier involves a template
208 bool isInstantiationDependent() const;
210 /// Whether this nested-name-specifier contains an unexpanded
211 /// parameter pack (for C++11 variadic templates).
212 bool containsUnexpandedParameterPack() const;
214 /// Print this nested name specifier to the given output stream. If
215 /// `ResolveTemplateArguments` is true, we'll print actual types, e.g.
216 /// `ns::SomeTemplate<int, MyClass>` instead of
217 /// `ns::SomeTemplate<Container::value_type, T>`.
218 void print(raw_ostream &OS, const PrintingPolicy &Policy,
219 bool ResolveTemplateArguments = false) const;
221 void Profile(llvm::FoldingSetNodeID &ID) const {
222 ID.AddPointer(Prefix.getOpaqueValue());
223 ID.AddPointer(Specifier);
226 /// Dump the nested name specifier to standard output to aid
228 void dump(const LangOptions &LO) const;
230 void dump(llvm::raw_ostream &OS) const;
231 void dump(llvm::raw_ostream &OS, const LangOptions &LO) const;
234 /// A C++ nested-name-specifier augmented with source location
236 class NestedNameSpecifierLoc {
237 NestedNameSpecifier *Qualifier = nullptr;
238 void *Data = nullptr;
240 /// Determines the data length for the last component in the
241 /// given nested-name-specifier.
242 static unsigned getLocalDataLength(NestedNameSpecifier *Qualifier);
244 /// Determines the data length for the entire
245 /// nested-name-specifier.
246 static unsigned getDataLength(NestedNameSpecifier *Qualifier);
249 /// Construct an empty nested-name-specifier.
250 NestedNameSpecifierLoc() = default;
252 /// Construct a nested-name-specifier with source location information
254 NestedNameSpecifierLoc(NestedNameSpecifier *Qualifier, void *Data)
255 : Qualifier(Qualifier), Data(Data) {}
257 /// Evaluates true when this nested-name-specifier location is
259 explicit operator bool() const { return Qualifier; }
261 /// Evaluates true when this nested-name-specifier location is
263 bool hasQualifier() const { return Qualifier; }
265 /// Retrieve the nested-name-specifier to which this instance
267 NestedNameSpecifier *getNestedNameSpecifier() const {
271 /// Retrieve the opaque pointer that refers to source-location data.
272 void *getOpaqueData() const { return Data; }
274 /// Retrieve the source range covering the entirety of this
275 /// nested-name-specifier.
277 /// For example, if this instance refers to a nested-name-specifier
278 /// \c \::std::vector<int>::, the returned source range would cover
279 /// from the initial '::' to the last '::'.
280 SourceRange getSourceRange() const LLVM_READONLY;
282 /// Retrieve the source range covering just the last part of
283 /// this nested-name-specifier, not including the prefix.
285 /// For example, if this instance refers to a nested-name-specifier
286 /// \c \::std::vector<int>::, the returned source range would cover
287 /// from "vector" to the last '::'.
288 SourceRange getLocalSourceRange() const;
290 /// Retrieve the location of the beginning of this
291 /// nested-name-specifier.
292 SourceLocation getBeginLoc() const {
293 return getSourceRange().getBegin();
296 /// Retrieve the location of the end of this
297 /// nested-name-specifier.
298 SourceLocation getEndLoc() const {
299 return getSourceRange().getEnd();
302 /// Retrieve the location of the beginning of this
303 /// component of the nested-name-specifier.
304 SourceLocation getLocalBeginLoc() const {
305 return getLocalSourceRange().getBegin();
308 /// Retrieve the location of the end of this component of the
309 /// nested-name-specifier.
310 SourceLocation getLocalEndLoc() const {
311 return getLocalSourceRange().getEnd();
314 /// Return the prefix of this nested-name-specifier.
316 /// For example, if this instance refers to a nested-name-specifier
317 /// \c \::std::vector<int>::, the prefix is \c \::std::. Note that the
318 /// returned prefix may be empty, if this is the first component of
319 /// the nested-name-specifier.
320 NestedNameSpecifierLoc getPrefix() const {
324 return NestedNameSpecifierLoc(Qualifier->getPrefix(), Data);
327 /// For a nested-name-specifier that refers to a type,
328 /// retrieve the type with source-location information.
329 TypeLoc getTypeLoc() const;
331 /// Determines the data length for the entire
332 /// nested-name-specifier.
333 unsigned getDataLength() const { return getDataLength(Qualifier); }
335 friend bool operator==(NestedNameSpecifierLoc X,
336 NestedNameSpecifierLoc Y) {
337 return X.Qualifier == Y.Qualifier && X.Data == Y.Data;
340 friend bool operator!=(NestedNameSpecifierLoc X,
341 NestedNameSpecifierLoc Y) {
346 /// Class that aids in the construction of nested-name-specifiers along
347 /// with source-location information for all of the components of the
348 /// nested-name-specifier.
349 class NestedNameSpecifierLocBuilder {
350 /// The current representation of the nested-name-specifier we're
352 NestedNameSpecifier *Representation = nullptr;
354 /// Buffer used to store source-location information for the
355 /// nested-name-specifier.
357 /// Note that we explicitly manage the buffer (rather than using a
358 /// SmallVector) because \c Declarator expects it to be possible to memcpy()
359 /// a \c CXXScopeSpec, and CXXScopeSpec uses a NestedNameSpecifierLocBuilder.
360 char *Buffer = nullptr;
362 /// The size of the buffer used to store source-location information
363 /// for the nested-name-specifier.
364 unsigned BufferSize = 0;
366 /// The capacity of the buffer used to store source-location
367 /// information for the nested-name-specifier.
368 unsigned BufferCapacity = 0;
371 NestedNameSpecifierLocBuilder() = default;
372 NestedNameSpecifierLocBuilder(const NestedNameSpecifierLocBuilder &Other);
374 NestedNameSpecifierLocBuilder &
375 operator=(const NestedNameSpecifierLocBuilder &Other);
377 ~NestedNameSpecifierLocBuilder() {
382 /// Retrieve the representation of the nested-name-specifier.
383 NestedNameSpecifier *getRepresentation() const { return Representation; }
385 /// Extend the current nested-name-specifier by another
386 /// nested-name-specifier component of the form 'type::'.
388 /// \param Context The AST context in which this nested-name-specifier
391 /// \param TemplateKWLoc The location of the 'template' keyword, if present.
393 /// \param TL The TypeLoc that describes the type preceding the '::'.
395 /// \param ColonColonLoc The location of the trailing '::'.
396 void Extend(ASTContext &Context, SourceLocation TemplateKWLoc, TypeLoc TL,
397 SourceLocation ColonColonLoc);
399 /// Extend the current nested-name-specifier by another
400 /// nested-name-specifier component of the form 'identifier::'.
402 /// \param Context The AST context in which this nested-name-specifier
405 /// \param Identifier The identifier.
407 /// \param IdentifierLoc The location of the identifier.
409 /// \param ColonColonLoc The location of the trailing '::'.
410 void Extend(ASTContext &Context, IdentifierInfo *Identifier,
411 SourceLocation IdentifierLoc, SourceLocation ColonColonLoc);
413 /// Extend the current nested-name-specifier by another
414 /// nested-name-specifier component of the form 'namespace::'.
416 /// \param Context The AST context in which this nested-name-specifier
419 /// \param Namespace The namespace.
421 /// \param NamespaceLoc The location of the namespace name.
423 /// \param ColonColonLoc The location of the trailing '::'.
424 void Extend(ASTContext &Context, NamespaceDecl *Namespace,
425 SourceLocation NamespaceLoc, SourceLocation ColonColonLoc);
427 /// Extend the current nested-name-specifier by another
428 /// nested-name-specifier component of the form 'namespace-alias::'.
430 /// \param Context The AST context in which this nested-name-specifier
433 /// \param Alias The namespace alias.
435 /// \param AliasLoc The location of the namespace alias
438 /// \param ColonColonLoc The location of the trailing '::'.
439 void Extend(ASTContext &Context, NamespaceAliasDecl *Alias,
440 SourceLocation AliasLoc, SourceLocation ColonColonLoc);
442 /// Turn this (empty) nested-name-specifier into the global
443 /// nested-name-specifier '::'.
444 void MakeGlobal(ASTContext &Context, SourceLocation ColonColonLoc);
446 /// Turns this (empty) nested-name-specifier into '__super'
447 /// nested-name-specifier.
449 /// \param Context The AST context in which this nested-name-specifier
452 /// \param RD The declaration of the class in which nested-name-specifier
455 /// \param SuperLoc The location of the '__super' keyword.
458 /// \param ColonColonLoc The location of the trailing '::'.
459 void MakeSuper(ASTContext &Context, CXXRecordDecl *RD,
460 SourceLocation SuperLoc, SourceLocation ColonColonLoc);
462 /// Make a new nested-name-specifier from incomplete source-location
465 /// This routine should be used very, very rarely, in cases where we
466 /// need to synthesize a nested-name-specifier. Most code should instead use
467 /// \c Adopt() with a proper \c NestedNameSpecifierLoc.
468 void MakeTrivial(ASTContext &Context, NestedNameSpecifier *Qualifier,
471 /// Adopt an existing nested-name-specifier (with source-range
473 void Adopt(NestedNameSpecifierLoc Other);
475 /// Retrieve the source range covered by this nested-name-specifier.
476 SourceRange getSourceRange() const LLVM_READONLY {
477 return NestedNameSpecifierLoc(Representation, Buffer).getSourceRange();
480 /// Retrieve a nested-name-specifier with location information,
481 /// copied into the given AST context.
483 /// \param Context The context into which this nested-name-specifier will be
485 NestedNameSpecifierLoc getWithLocInContext(ASTContext &Context) const;
487 /// Retrieve a nested-name-specifier with location
488 /// information based on the information in this builder.
490 /// This loc will contain references to the builder's internal data and may
491 /// be invalidated by any change to the builder.
492 NestedNameSpecifierLoc getTemporary() const {
493 return NestedNameSpecifierLoc(Representation, Buffer);
496 /// Clear out this builder, and prepare it to build another
497 /// nested-name-specifier with source-location information.
499 Representation = nullptr;
503 /// Retrieve the underlying buffer.
505 /// \returns A pair containing a pointer to the buffer of source-location
506 /// data and the size of the source-location data that resides in that
508 std::pair<char *, unsigned> getBuffer() const {
509 return std::make_pair(Buffer, BufferSize);
513 /// Insertion operator for diagnostics. This allows sending
514 /// NestedNameSpecifiers into a diagnostic with <<.
515 inline const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB,
516 NestedNameSpecifier *NNS) {
517 DB.AddTaggedVal(reinterpret_cast<intptr_t>(NNS),
518 DiagnosticsEngine::ak_nestednamespec);
524 #endif // LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H