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NestedNameSpecifier.h
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1 //===- NestedNameSpecifier.h - C++ nested name specifiers -------*- C++ -*-===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file defines the NestedNameSpecifier class, which represents
11 // a C++ nested-name-specifier.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H
16 #define LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H
17 
18 #include "clang/Basic/Diagnostic.h"
20 #include "llvm/ADT/FoldingSet.h"
21 #include "llvm/ADT/PointerIntPair.h"
22 #include "llvm/Support/Compiler.h"
23 #include <cstdint>
24 #include <cstdlib>
25 #include <utility>
26 
27 namespace clang {
28 
29 class ASTContext;
30 class CXXRecordDecl;
31 class IdentifierInfo;
32 class LangOptions;
33 class NamespaceAliasDecl;
34 class NamespaceDecl;
35 struct PrintingPolicy;
36 class Type;
37 class TypeLoc;
38 
39 /// \brief Represents a C++ nested name specifier, such as
40 /// "\::std::vector<int>::".
41 ///
42 /// C++ nested name specifiers are the prefixes to qualified
43 /// names. For example, "foo::" in "foo::x" is a nested name
44 /// specifier. Nested name specifiers are made up of a sequence of
45 /// specifiers, each of which can be a namespace, type, identifier
46 /// (for dependent names), decltype specifier, or the global specifier ('::').
47 /// The last two specifiers can only appear at the start of a
48 /// nested-namespace-specifier.
49 class NestedNameSpecifier : public llvm::FoldingSetNode {
50  /// \brief Enumeration describing
51  enum StoredSpecifierKind {
52  StoredIdentifier = 0,
53  StoredDecl = 1,
54  StoredTypeSpec = 2,
55  StoredTypeSpecWithTemplate = 3
56  };
57 
58  /// \brief The nested name specifier that precedes this nested name
59  /// specifier.
60  ///
61  /// The pointer is the nested-name-specifier that precedes this
62  /// one. The integer stores one of the first four values of type
63  /// SpecifierKind.
64  llvm::PointerIntPair<NestedNameSpecifier *, 2, StoredSpecifierKind> Prefix;
65 
66  /// \brief The last component in the nested name specifier, which
67  /// can be an identifier, a declaration, or a type.
68  ///
69  /// When the pointer is NULL, this specifier represents the global
70  /// specifier '::'. Otherwise, the pointer is one of
71  /// IdentifierInfo*, Namespace*, or Type*, depending on the kind of
72  /// specifier as encoded within the prefix.
73  void* Specifier = nullptr;
74 
75 public:
76  /// \brief The kind of specifier that completes this nested name
77  /// specifier.
79  /// \brief An identifier, stored as an IdentifierInfo*.
81 
82  /// \brief A namespace, stored as a NamespaceDecl*.
84 
85  /// \brief A namespace alias, stored as a NamespaceAliasDecl*.
87 
88  /// \brief A type, stored as a Type*.
90 
91  /// \brief A type that was preceded by the 'template' keyword,
92  /// stored as a Type*.
94 
95  /// \brief The global specifier '::'. There is no stored value.
97 
98  /// \brief Microsoft's '__super' specifier, stored as a CXXRecordDecl* of
99  /// the class it appeared in.
101  };
102 
103 private:
104  /// \brief Builds the global specifier.
105  NestedNameSpecifier() : Prefix(nullptr, StoredIdentifier) {}
106 
107  /// \brief Copy constructor used internally to clone nested name
108  /// specifiers.
109  NestedNameSpecifier(const NestedNameSpecifier &Other) = default;
110 
111  /// \brief Either find or insert the given nested name specifier
112  /// mockup in the given context.
113  static NestedNameSpecifier *FindOrInsert(const ASTContext &Context,
114  const NestedNameSpecifier &Mockup);
115 
116 public:
118 
119  /// \brief Builds a specifier combining a prefix and an identifier.
120  ///
121  /// The prefix must be dependent, since nested name specifiers
122  /// referencing an identifier are only permitted when the identifier
123  /// cannot be resolved.
124  static NestedNameSpecifier *Create(const ASTContext &Context,
125  NestedNameSpecifier *Prefix,
126  IdentifierInfo *II);
127 
128  /// \brief Builds a nested name specifier that names a namespace.
129  static NestedNameSpecifier *Create(const ASTContext &Context,
130  NestedNameSpecifier *Prefix,
131  const NamespaceDecl *NS);
132 
133  /// \brief Builds a nested name specifier that names a namespace alias.
134  static NestedNameSpecifier *Create(const ASTContext &Context,
135  NestedNameSpecifier *Prefix,
136  NamespaceAliasDecl *Alias);
137 
138  /// \brief Builds a nested name specifier that names a type.
139  static NestedNameSpecifier *Create(const ASTContext &Context,
140  NestedNameSpecifier *Prefix,
141  bool Template, const Type *T);
142 
143  /// \brief Builds a specifier that consists of just an identifier.
144  ///
145  /// The nested-name-specifier is assumed to be dependent, but has no
146  /// prefix because the prefix is implied by something outside of the
147  /// nested name specifier, e.g., in "x->Base::f", the "x" has a dependent
148  /// type.
149  static NestedNameSpecifier *Create(const ASTContext &Context,
150  IdentifierInfo *II);
151 
152  /// \brief Returns the nested name specifier representing the global
153  /// scope.
154  static NestedNameSpecifier *GlobalSpecifier(const ASTContext &Context);
155 
156  /// \brief Returns the nested name specifier representing the __super scope
157  /// for the given CXXRecordDecl.
158  static NestedNameSpecifier *SuperSpecifier(const ASTContext &Context,
159  CXXRecordDecl *RD);
160 
161  /// \brief Return the prefix of this nested name specifier.
162  ///
163  /// The prefix contains all of the parts of the nested name
164  /// specifier that preced this current specifier. For example, for a
165  /// nested name specifier that represents "foo::bar::", the current
166  /// specifier will contain "bar::" and the prefix will contain
167  /// "foo::".
168  NestedNameSpecifier *getPrefix() const { return Prefix.getPointer(); }
169 
170  /// \brief Determine what kind of nested name specifier is stored.
171  SpecifierKind getKind() const;
172 
173  /// \brief Retrieve the identifier stored in this nested name
174  /// specifier.
176  if (Prefix.getInt() == StoredIdentifier)
177  return (IdentifierInfo *)Specifier;
178 
179  return nullptr;
180  }
181 
182  /// \brief Retrieve the namespace stored in this nested name
183  /// specifier.
184  NamespaceDecl *getAsNamespace() const;
185 
186  /// \brief Retrieve the namespace alias stored in this nested name
187  /// specifier.
189 
190  /// \brief Retrieve the record declaration stored in this nested name
191  /// specifier.
193 
194  /// \brief Retrieve the type stored in this nested name specifier.
195  const Type *getAsType() const {
196  if (Prefix.getInt() == StoredTypeSpec ||
197  Prefix.getInt() == StoredTypeSpecWithTemplate)
198  return (const Type *)Specifier;
199 
200  return nullptr;
201  }
202 
203  /// \brief Whether this nested name specifier refers to a dependent
204  /// type or not.
205  bool isDependent() const;
206 
207  /// \brief Whether this nested name specifier involves a template
208  /// parameter.
209  bool isInstantiationDependent() const;
210 
211  /// \brief Whether this nested-name-specifier contains an unexpanded
212  /// parameter pack (for C++11 variadic templates).
213  bool containsUnexpandedParameterPack() const;
214 
215  /// \brief Print this nested name specifier to the given output
216  /// stream.
217  void print(raw_ostream &OS, const PrintingPolicy &Policy) const;
218 
219  void Profile(llvm::FoldingSetNodeID &ID) const {
220  ID.AddPointer(Prefix.getOpaqueValue());
221  ID.AddPointer(Specifier);
222  }
223 
224  /// \brief Dump the nested name specifier to standard output to aid
225  /// in debugging.
226  void dump(const LangOptions &LO) const;
227  void dump() const;
228 };
229 
230 /// \brief A C++ nested-name-specifier augmented with source location
231 /// information.
233  NestedNameSpecifier *Qualifier = nullptr;
234  void *Data = nullptr;
235 
236  /// \brief Determines the data length for the last component in the
237  /// given nested-name-specifier.
238  static unsigned getLocalDataLength(NestedNameSpecifier *Qualifier);
239 
240  /// \brief Determines the data length for the entire
241  /// nested-name-specifier.
242  static unsigned getDataLength(NestedNameSpecifier *Qualifier);
243 
244 public:
245  /// \brief Construct an empty nested-name-specifier.
246  NestedNameSpecifierLoc() = default;
247 
248  /// \brief Construct a nested-name-specifier with source location information
249  /// from
251  : Qualifier(Qualifier), Data(Data) {}
252 
253  /// \brief Evalutes true when this nested-name-specifier location is
254  /// non-empty.
255  explicit operator bool() const { return Qualifier; }
256 
257  /// \brief Evalutes true when this nested-name-specifier location is
258  /// empty.
259  bool hasQualifier() const { return Qualifier; }
260 
261  /// \brief Retrieve the nested-name-specifier to which this instance
262  /// refers.
264  return Qualifier;
265  }
266 
267  /// \brief Retrieve the opaque pointer that refers to source-location data.
268  void *getOpaqueData() const { return Data; }
269 
270  /// \brief Retrieve the source range covering the entirety of this
271  /// nested-name-specifier.
272  ///
273  /// For example, if this instance refers to a nested-name-specifier
274  /// \c \::std::vector<int>::, the returned source range would cover
275  /// from the initial '::' to the last '::'.
276  SourceRange getSourceRange() const LLVM_READONLY;
277 
278  /// \brief Retrieve the source range covering just the last part of
279  /// this nested-name-specifier, not including the prefix.
280  ///
281  /// For example, if this instance refers to a nested-name-specifier
282  /// \c \::std::vector<int>::, the returned source range would cover
283  /// from "vector" to the last '::'.
284  SourceRange getLocalSourceRange() const;
285 
286  /// \brief Retrieve the location of the beginning of this
287  /// nested-name-specifier.
289  return getSourceRange().getBegin();
290  }
291 
292  /// \brief Retrieve the location of the end of this
293  /// nested-name-specifier.
295  return getSourceRange().getEnd();
296  }
297 
298  /// \brief Retrieve the location of the beginning of this
299  /// component of the nested-name-specifier.
301  return getLocalSourceRange().getBegin();
302  }
303 
304  /// \brief Retrieve the location of the end of this component of the
305  /// nested-name-specifier.
307  return getLocalSourceRange().getEnd();
308  }
309 
310  /// \brief Return the prefix of this nested-name-specifier.
311  ///
312  /// For example, if this instance refers to a nested-name-specifier
313  /// \c \::std::vector<int>::, the prefix is \c \::std::. Note that the
314  /// returned prefix may be empty, if this is the first component of
315  /// the nested-name-specifier.
317  if (!Qualifier)
318  return *this;
319 
320  return NestedNameSpecifierLoc(Qualifier->getPrefix(), Data);
321  }
322 
323  /// \brief For a nested-name-specifier that refers to a type,
324  /// retrieve the type with source-location information.
325  TypeLoc getTypeLoc() const;
326 
327  /// \brief Determines the data length for the entire
328  /// nested-name-specifier.
329  unsigned getDataLength() const { return getDataLength(Qualifier); }
330 
333  return X.Qualifier == Y.Qualifier && X.Data == Y.Data;
334  }
335 
338  return !(X == Y);
339  }
340 };
341 
342 /// \brief Class that aids in the construction of nested-name-specifiers along
343 /// with source-location information for all of the components of the
344 /// nested-name-specifier.
346  /// \brief The current representation of the nested-name-specifier we're
347  /// building.
348  NestedNameSpecifier *Representation = nullptr;
349 
350  /// \brief Buffer used to store source-location information for the
351  /// nested-name-specifier.
352  ///
353  /// Note that we explicitly manage the buffer (rather than using a
354  /// SmallVector) because \c Declarator expects it to be possible to memcpy()
355  /// a \c CXXScopeSpec, and CXXScopeSpec uses a NestedNameSpecifierLocBuilder.
356  char *Buffer = nullptr;
357 
358  /// \brief The size of the buffer used to store source-location information
359  /// for the nested-name-specifier.
360  unsigned BufferSize = 0;
361 
362  /// \brief The capacity of the buffer used to store source-location
363  /// information for the nested-name-specifier.
364  unsigned BufferCapacity = 0;
365 
366 public:
367  NestedNameSpecifierLocBuilder() = default;
369 
372 
374  if (BufferCapacity)
375  free(Buffer);
376  }
377 
378  /// \brief Retrieve the representation of the nested-name-specifier.
379  NestedNameSpecifier *getRepresentation() const { return Representation; }
380 
381  /// \brief Extend the current nested-name-specifier by another
382  /// nested-name-specifier component of the form 'type::'.
383  ///
384  /// \param Context The AST context in which this nested-name-specifier
385  /// resides.
386  ///
387  /// \param TemplateKWLoc The location of the 'template' keyword, if present.
388  ///
389  /// \param TL The TypeLoc that describes the type preceding the '::'.
390  ///
391  /// \param ColonColonLoc The location of the trailing '::'.
392  void Extend(ASTContext &Context, SourceLocation TemplateKWLoc, TypeLoc TL,
393  SourceLocation ColonColonLoc);
394 
395  /// \brief Extend the current nested-name-specifier by another
396  /// nested-name-specifier component of the form 'identifier::'.
397  ///
398  /// \param Context The AST context in which this nested-name-specifier
399  /// resides.
400  ///
401  /// \param Identifier The identifier.
402  ///
403  /// \param IdentifierLoc The location of the identifier.
404  ///
405  /// \param ColonColonLoc The location of the trailing '::'.
406  void Extend(ASTContext &Context, IdentifierInfo *Identifier,
408 
409  /// \brief Extend the current nested-name-specifier by another
410  /// nested-name-specifier component of the form 'namespace::'.
411  ///
412  /// \param Context The AST context in which this nested-name-specifier
413  /// resides.
414  ///
415  /// \param Namespace The namespace.
416  ///
417  /// \param NamespaceLoc The location of the namespace name.
418  ///
419  /// \param ColonColonLoc The location of the trailing '::'.
420  void Extend(ASTContext &Context, NamespaceDecl *Namespace,
421  SourceLocation NamespaceLoc, SourceLocation ColonColonLoc);
422 
423  /// \brief Extend the current nested-name-specifier by another
424  /// nested-name-specifier component of the form 'namespace-alias::'.
425  ///
426  /// \param Context The AST context in which this nested-name-specifier
427  /// resides.
428  ///
429  /// \param Alias The namespace alias.
430  ///
431  /// \param AliasLoc The location of the namespace alias
432  /// name.
433  ///
434  /// \param ColonColonLoc The location of the trailing '::'.
435  void Extend(ASTContext &Context, NamespaceAliasDecl *Alias,
436  SourceLocation AliasLoc, SourceLocation ColonColonLoc);
437 
438  /// \brief Turn this (empty) nested-name-specifier into the global
439  /// nested-name-specifier '::'.
440  void MakeGlobal(ASTContext &Context, SourceLocation ColonColonLoc);
441 
442  /// \brief Turns this (empty) nested-name-specifier into '__super'
443  /// nested-name-specifier.
444  ///
445  /// \param Context The AST context in which this nested-name-specifier
446  /// resides.
447  ///
448  /// \param RD The declaration of the class in which nested-name-specifier
449  /// appeared.
450  ///
451  /// \param SuperLoc The location of the '__super' keyword.
452  /// name.
453  ///
454  /// \param ColonColonLoc The location of the trailing '::'.
455  void MakeSuper(ASTContext &Context, CXXRecordDecl *RD,
456  SourceLocation SuperLoc, SourceLocation ColonColonLoc);
457 
458  /// \brief Make a new nested-name-specifier from incomplete source-location
459  /// information.
460  ///
461  /// This routine should be used very, very rarely, in cases where we
462  /// need to synthesize a nested-name-specifier. Most code should instead use
463  /// \c Adopt() with a proper \c NestedNameSpecifierLoc.
464  void MakeTrivial(ASTContext &Context, NestedNameSpecifier *Qualifier,
465  SourceRange R);
466 
467  /// \brief Adopt an existing nested-name-specifier (with source-range
468  /// information).
469  void Adopt(NestedNameSpecifierLoc Other);
470 
471  /// \brief Retrieve the source range covered by this nested-name-specifier.
472  SourceRange getSourceRange() const LLVM_READONLY {
473  return NestedNameSpecifierLoc(Representation, Buffer).getSourceRange();
474  }
475 
476  /// \brief Retrieve a nested-name-specifier with location information,
477  /// copied into the given AST context.
478  ///
479  /// \param Context The context into which this nested-name-specifier will be
480  /// copied.
481  NestedNameSpecifierLoc getWithLocInContext(ASTContext &Context) const;
482 
483  /// \brief Retrieve a nested-name-specifier with location
484  /// information based on the information in this builder.
485  ///
486  /// This loc will contain references to the builder's internal data and may
487  /// be invalidated by any change to the builder.
489  return NestedNameSpecifierLoc(Representation, Buffer);
490  }
491 
492  /// \brief Clear out this builder, and prepare it to build another
493  /// nested-name-specifier with source-location information.
494  void Clear() {
495  Representation = nullptr;
496  BufferSize = 0;
497  }
498 
499  /// \brief Retrieve the underlying buffer.
500  ///
501  /// \returns A pair containing a pointer to the buffer of source-location
502  /// data and the size of the source-location data that resides in that
503  /// buffer.
504  std::pair<char *, unsigned> getBuffer() const {
505  return std::make_pair(Buffer, BufferSize);
506  }
507 };
508 
509 /// Insertion operator for diagnostics. This allows sending
510 /// NestedNameSpecifiers into a diagnostic with <<.
512  NestedNameSpecifier *NNS) {
513  DB.AddTaggedVal(reinterpret_cast<intptr_t>(NNS),
515  return DB;
516 }
517 
518 } // namespace clang
519 
520 #endif // LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H
SourceRange getSourceRange() const LLVM_READONLY
Retrieve the source range covering the entirety of this nested-name-specifier.
Microsoft&#39;s &#39;__super&#39; specifier, stored as a CXXRecordDecl* of the class it appeared in...
friend bool operator!=(NestedNameSpecifierLoc X, NestedNameSpecifierLoc Y)
NestedNameSpecifier * getPrefix() const
Return the prefix of this nested name specifier.
const DiagnosticBuilder & operator<<(const DiagnosticBuilder &DB, const Attr *At)
Definition: Attr.h:195
The base class of the type hierarchy.
Definition: Type.h:1353
NestedNameSpecifierLoc getTemporary() const
Retrieve a nested-name-specifier with location information based on the information in this builder...
NamespaceDecl - Represent a C++ namespace.
Definition: Decl.h:506
void Profile(llvm::FoldingSetNodeID &ID) const
SourceLocation getLocalBeginLoc() const
Retrieve the location of the beginning of this component of the nested-name-specifier.
NestedNameSpecifier & operator=(const NestedNameSpecifier &)=delete
An identifier, stored as an IdentifierInfo*.
std::pair< char *, unsigned > getBuffer() const
Retrieve the underlying buffer.
static NestedNameSpecifier * Create(const ASTContext &Context, NestedNameSpecifier *Prefix, IdentifierInfo *II)
Builds a specifier combining a prefix and an identifier.
A namespace, stored as a NamespaceDecl*.
Describes how types, statements, expressions, and declarations should be printed. ...
Definition: PrettyPrinter.h:38
SpecifierKind getKind() const
Determine what kind of nested name specifier is stored.
bool hasQualifier() const
Evalutes true when this nested-name-specifier location is empty.
Base wrapper for a particular "section" of type source info.
Definition: TypeLoc.h:56
void AddTaggedVal(intptr_t V, DiagnosticsEngine::ArgumentKind Kind) const
Definition: Diagnostic.h:1069
One of these records is kept for each identifier that is lexed.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:149
A C++ nested-name-specifier augmented with source location information.
const Type * getAsType() const
Retrieve the type stored in this nested name specifier.
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:48
friend bool operator==(NestedNameSpecifierLoc X, NestedNameSpecifierLoc Y)
CXXRecordDecl * getAsRecordDecl() const
Retrieve the record declaration stored in this nested name specifier.
IdentifierInfo * getAsIdentifier() const
Retrieve the identifier stored in this nested name specifier.
NamespaceAliasDecl * getAsNamespaceAlias() const
Retrieve the namespace alias stored in this nested name specifier.
Defines the Diagnostic-related interfaces.
SourceLocation getLocalEndLoc() const
Retrieve the location of the end of this component of the nested-name-specifier.
Class that aids in the construction of nested-name-specifiers along with source-location information ...
SourceRange getSourceRange() const LLVM_READONLY
Retrieve the source range covered by this nested-name-specifier.
bool isInstantiationDependent() const
Whether this nested name specifier involves a template parameter.
A little helper class used to produce diagnostics.
Definition: Diagnostic.h:955
void print(raw_ostream &OS, const PrintingPolicy &Policy) const
Print this nested name specifier to the given output stream.
static NestedNameSpecifier * SuperSpecifier(const ASTContext &Context, CXXRecordDecl *RD)
Returns the nested name specifier representing the __super scope for the given CXXRecordDecl.
NamespaceDecl * getAsNamespace() const
Retrieve the namespace stored in this nested name specifier.
const FunctionProtoType * T
SourceLocation getBeginLoc() const
Retrieve the location of the beginning of this nested-name-specifier.
#define bool
Definition: stdbool.h:31
NestedNameSpecifierLoc getPrefix() const
Return the prefix of this nested-name-specifier.
A namespace alias, stored as a NamespaceAliasDecl*.
SourceLocation getEnd() const
Wraps an identifier and optional source location for the identifier.
Definition: AttributeList.h:73
The l-value was considered opaque, so the alignment was determined from a type.
SpecifierKind
The kind of specifier that completes this nested name specifier.
bool containsUnexpandedParameterPack() const
Whether this nested-name-specifier contains an unexpanded parameter pack (for C++11 variadic template...
Encodes a location in the source.
NestedNameSpecifier * getRepresentation() const
Retrieve the representation of the nested-name-specifier.
Represents a C++ nested name specifier, such as "\::std::vector<int>::".
NestedNameSpecifierLoc(NestedNameSpecifier *Qualifier, void *Data)
Construct a nested-name-specifier with source location information from.
Dataflow Directional Tag Classes.
NestedNameSpecifier * getNestedNameSpecifier() const
Retrieve the nested-name-specifier to which this instance refers.
SourceRange getSourceRange(const SourceRange &Range)
Returns the SourceRange of a SourceRange.
Definition: FixIt.h:34
unsigned getDataLength() const
Determines the data length for the entire nested-name-specifier.
bool isDependent() const
Whether this nested name specifier refers to a dependent type or not.
A type that was preceded by the &#39;template&#39; keyword, stored as a Type*.
SourceLocation getEndLoc() const
Retrieve the location of the end of this nested-name-specifier.
X
Add a minimal nested name specifier fixit hint to allow lookup of a tag name from an outer enclosing ...
Definition: SemaDecl.cpp:13010
void * getOpaqueData() const
Retrieve the opaque pointer that refers to source-location data.
Defines the clang::SourceLocation class and associated facilities.
Represents a C++ struct/union/class.
Definition: DeclCXX.h:299
A trivial tuple used to represent a source range.
Represents a C++ namespace alias.
Definition: DeclCXX.h:2947
The global specifier &#39;::&#39;. There is no stored value.
SourceLocation getBegin() const
void Clear()
Clear out this builder, and prepare it to build another nested-name-specifier with source-location in...
static NestedNameSpecifier * GlobalSpecifier(const ASTContext &Context)
Returns the nested name specifier representing the global scope.