clang  6.0.0svn
NestedNameSpecifier.h
Go to the documentation of this file.
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 #ifndef LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H
15 #define LLVM_CLANG_AST_NESTEDNAMESPECIFIER_H
16 
17 #include "clang/Basic/Diagnostic.h"
18 #include "llvm/ADT/FoldingSet.h"
19 #include "llvm/ADT/PointerIntPair.h"
20 #include "llvm/Support/Compiler.h"
21 
22 namespace clang {
23 
24 class ASTContext;
25 class CXXRecordDecl;
26 class NamespaceAliasDecl;
27 class NamespaceDecl;
28 class IdentifierInfo;
29 struct PrintingPolicy;
30 class Type;
31 class TypeLoc;
32 class LangOptions;
33 
34 /// \brief Represents a C++ nested name specifier, such as
35 /// "\::std::vector<int>::".
36 ///
37 /// C++ nested name specifiers are the prefixes to qualified
38 /// namespaces. For example, "foo::" in "foo::x" is a nested name
39 /// specifier. Nested name specifiers are made up of a sequence of
40 /// specifiers, each of which can be a namespace, type, identifier
41 /// (for dependent names), decltype specifier, or the global specifier ('::').
42 /// The last two specifiers can only appear at the start of a
43 /// nested-namespace-specifier.
44 class NestedNameSpecifier : public llvm::FoldingSetNode {
45 
46  /// \brief Enumeration describing
47  enum StoredSpecifierKind {
48  StoredIdentifier = 0,
49  StoredDecl = 1,
50  StoredTypeSpec = 2,
51  StoredTypeSpecWithTemplate = 3
52  };
53 
54  /// \brief The nested name specifier that precedes this nested name
55  /// specifier.
56  ///
57  /// The pointer is the nested-name-specifier that precedes this
58  /// one. The integer stores one of the first four values of type
59  /// SpecifierKind.
60  llvm::PointerIntPair<NestedNameSpecifier *, 2, StoredSpecifierKind> Prefix;
61 
62  /// \brief The last component in the nested name specifier, which
63  /// can be an identifier, a declaration, or a type.
64  ///
65  /// When the pointer is NULL, this specifier represents the global
66  /// specifier '::'. Otherwise, the pointer is one of
67  /// IdentifierInfo*, Namespace*, or Type*, depending on the kind of
68  /// specifier as encoded within the prefix.
69  void* Specifier;
70 
71 public:
72  /// \brief The kind of specifier that completes this nested name
73  /// specifier.
75  /// \brief An identifier, stored as an IdentifierInfo*.
77  /// \brief A namespace, stored as a NamespaceDecl*.
79  /// \brief A namespace alias, stored as a NamespaceAliasDecl*.
81  /// \brief A type, stored as a Type*.
83  /// \brief A type that was preceded by the 'template' keyword,
84  /// stored as a Type*.
86  /// \brief The global specifier '::'. There is no stored value.
88  /// \brief Microsoft's '__super' specifier, stored as a CXXRecordDecl* of
89  /// the class it appeared in.
91  };
92 
93 private:
94  /// \brief Builds the global specifier.
96  : Prefix(nullptr, StoredIdentifier), Specifier(nullptr) {}
97 
98  /// \brief Copy constructor used internally to clone nested name
99  /// specifiers.
101  : llvm::FoldingSetNode(Other), Prefix(Other.Prefix),
102  Specifier(Other.Specifier) {
103  }
104 
105  void operator=(const NestedNameSpecifier &) = delete;
106 
107  /// \brief Either find or insert the given nested name specifier
108  /// mockup in the given context.
109  static NestedNameSpecifier *FindOrInsert(const ASTContext &Context,
110  const NestedNameSpecifier &Mockup);
111 
112 public:
113  /// \brief Builds a specifier combining a prefix and an identifier.
114  ///
115  /// The prefix must be dependent, since nested name specifiers
116  /// referencing an identifier are only permitted when the identifier
117  /// cannot be resolved.
118  static NestedNameSpecifier *Create(const ASTContext &Context,
119  NestedNameSpecifier *Prefix,
120  IdentifierInfo *II);
121 
122  /// \brief Builds a nested name specifier that names a namespace.
123  static NestedNameSpecifier *Create(const ASTContext &Context,
124  NestedNameSpecifier *Prefix,
125  const NamespaceDecl *NS);
126 
127  /// \brief Builds a nested name specifier that names a namespace alias.
128  static NestedNameSpecifier *Create(const ASTContext &Context,
129  NestedNameSpecifier *Prefix,
130  NamespaceAliasDecl *Alias);
131 
132  /// \brief Builds a nested name specifier that names a type.
133  static NestedNameSpecifier *Create(const ASTContext &Context,
134  NestedNameSpecifier *Prefix,
135  bool Template, const Type *T);
136 
137  /// \brief Builds a specifier that consists of just an identifier.
138  ///
139  /// The nested-name-specifier is assumed to be dependent, but has no
140  /// prefix because the prefix is implied by something outside of the
141  /// nested name specifier, e.g., in "x->Base::f", the "x" has a dependent
142  /// type.
143  static NestedNameSpecifier *Create(const ASTContext &Context,
144  IdentifierInfo *II);
145 
146  /// \brief Returns the nested name specifier representing the global
147  /// scope.
148  static NestedNameSpecifier *GlobalSpecifier(const ASTContext &Context);
149 
150  /// \brief Returns the nested name specifier representing the __super scope
151  /// for the given CXXRecordDecl.
152  static NestedNameSpecifier *SuperSpecifier(const ASTContext &Context,
153  CXXRecordDecl *RD);
154 
155  /// \brief Return the prefix of this nested name specifier.
156  ///
157  /// The prefix contains all of the parts of the nested name
158  /// specifier that preced this current specifier. For example, for a
159  /// nested name specifier that represents "foo::bar::", the current
160  /// specifier will contain "bar::" and the prefix will contain
161  /// "foo::".
162  NestedNameSpecifier *getPrefix() const { return Prefix.getPointer(); }
163 
164  /// \brief Determine what kind of nested name specifier is stored.
165  SpecifierKind getKind() const;
166 
167  /// \brief Retrieve the identifier stored in this nested name
168  /// specifier.
170  if (Prefix.getInt() == StoredIdentifier)
171  return (IdentifierInfo *)Specifier;
172 
173  return nullptr;
174  }
175 
176  /// \brief Retrieve the namespace stored in this nested name
177  /// specifier.
178  NamespaceDecl *getAsNamespace() const;
179 
180  /// \brief Retrieve the namespace alias stored in this nested name
181  /// specifier.
183 
184  /// \brief Retrieve the record declaration stored in this nested name
185  /// specifier.
187 
188  /// \brief Retrieve the type stored in this nested name specifier.
189  const Type *getAsType() const {
190  if (Prefix.getInt() == StoredTypeSpec ||
191  Prefix.getInt() == StoredTypeSpecWithTemplate)
192  return (const Type *)Specifier;
193 
194  return nullptr;
195  }
196 
197  /// \brief Whether this nested name specifier refers to a dependent
198  /// type or not.
199  bool isDependent() const;
200 
201  /// \brief Whether this nested name specifier involves a template
202  /// parameter.
203  bool isInstantiationDependent() const;
204 
205  /// \brief Whether this nested-name-specifier contains an unexpanded
206  /// parameter pack (for C++11 variadic templates).
207  bool containsUnexpandedParameterPack() const;
208 
209  /// \brief Print this nested name specifier to the given output
210  /// stream.
211  void print(raw_ostream &OS, const PrintingPolicy &Policy) const;
212 
213  void Profile(llvm::FoldingSetNodeID &ID) const {
214  ID.AddPointer(Prefix.getOpaqueValue());
215  ID.AddPointer(Specifier);
216  }
217 
218  /// \brief Dump the nested name specifier to standard output to aid
219  /// in debugging.
220  void dump(const LangOptions &LO) const;
221  void dump() const;
222 };
223 
224 /// \brief A C++ nested-name-specifier augmented with source location
225 /// information.
227  NestedNameSpecifier *Qualifier;
228  void *Data;
229 
230  /// \brief Determines the data length for the last component in the
231  /// given nested-name-specifier.
232  static unsigned getLocalDataLength(NestedNameSpecifier *Qualifier);
233 
234  /// \brief Determines the data length for the entire
235  /// nested-name-specifier.
236  static unsigned getDataLength(NestedNameSpecifier *Qualifier);
237 
238 public:
239  /// \brief Construct an empty nested-name-specifier.
240  NestedNameSpecifierLoc() : Qualifier(nullptr), Data(nullptr) { }
241 
242  /// \brief Construct a nested-name-specifier with source location information
243  /// from
245  : Qualifier(Qualifier), Data(Data) { }
246 
247  /// \brief Evalutes true when this nested-name-specifier location is
248  /// non-empty.
249  explicit operator bool() const { return Qualifier; }
250 
251  /// \brief Evalutes true when this nested-name-specifier location is
252  /// empty.
253  bool hasQualifier() const { return Qualifier; }
254 
255  /// \brief Retrieve the nested-name-specifier to which this instance
256  /// refers.
258  return Qualifier;
259  }
260 
261  /// \brief Retrieve the opaque pointer that refers to source-location data.
262  void *getOpaqueData() const { return Data; }
263 
264  /// \brief Retrieve the source range covering the entirety of this
265  /// nested-name-specifier.
266  ///
267  /// For example, if this instance refers to a nested-name-specifier
268  /// \c \::std::vector<int>::, the returned source range would cover
269  /// from the initial '::' to the last '::'.
270  SourceRange getSourceRange() const LLVM_READONLY;
271 
272  /// \brief Retrieve the source range covering just the last part of
273  /// this nested-name-specifier, not including the prefix.
274  ///
275  /// For example, if this instance refers to a nested-name-specifier
276  /// \c \::std::vector<int>::, the returned source range would cover
277  /// from "vector" to the last '::'.
278  SourceRange getLocalSourceRange() const;
279 
280  /// \brief Retrieve the location of the beginning of this
281  /// nested-name-specifier.
283  return getSourceRange().getBegin();
284  }
285 
286  /// \brief Retrieve the location of the end of this
287  /// nested-name-specifier.
289  return getSourceRange().getEnd();
290  }
291 
292  /// \brief Retrieve the location of the beginning of this
293  /// component of the nested-name-specifier.
295  return getLocalSourceRange().getBegin();
296  }
297 
298  /// \brief Retrieve the location of the end of this component of the
299  /// nested-name-specifier.
301  return getLocalSourceRange().getEnd();
302  }
303 
304  /// \brief Return the prefix of this nested-name-specifier.
305  ///
306  /// For example, if this instance refers to a nested-name-specifier
307  /// \c \::std::vector<int>::, the prefix is \c \::std::. Note that the
308  /// returned prefix may be empty, if this is the first component of
309  /// the nested-name-specifier.
311  if (!Qualifier)
312  return *this;
313 
314  return NestedNameSpecifierLoc(Qualifier->getPrefix(), Data);
315  }
316 
317  /// \brief For a nested-name-specifier that refers to a type,
318  /// retrieve the type with source-location information.
319  TypeLoc getTypeLoc() const;
320 
321  /// \brief Determines the data length for the entire
322  /// nested-name-specifier.
323  unsigned getDataLength() const { return getDataLength(Qualifier); }
324 
327  return X.Qualifier == Y.Qualifier && X.Data == Y.Data;
328  }
329 
332  return !(X == Y);
333  }
334 };
335 
336 /// \brief Class that aids in the construction of nested-name-specifiers along
337 /// with source-location information for all of the components of the
338 /// nested-name-specifier.
340  /// \brief The current representation of the nested-name-specifier we're
341  /// building.
342  NestedNameSpecifier *Representation;
343 
344  /// \brief Buffer used to store source-location information for the
345  /// nested-name-specifier.
346  ///
347  /// Note that we explicitly manage the buffer (rather than using a
348  /// SmallVector) because \c Declarator expects it to be possible to memcpy()
349  /// a \c CXXScopeSpec, and CXXScopeSpec uses a NestedNameSpecifierLocBuilder.
350  char *Buffer;
351 
352  /// \brief The size of the buffer used to store source-location information
353  /// for the nested-name-specifier.
354  unsigned BufferSize;
355 
356  /// \brief The capacity of the buffer used to store source-location
357  /// information for the nested-name-specifier.
358  unsigned BufferCapacity;
359 
360 public:
362  : Representation(nullptr), Buffer(nullptr), BufferSize(0),
363  BufferCapacity(0) {}
364 
366 
368  operator=(const NestedNameSpecifierLocBuilder &Other);
369 
371  if (BufferCapacity)
372  free(Buffer);
373  }
374 
375  /// \brief Retrieve the representation of the nested-name-specifier.
376  NestedNameSpecifier *getRepresentation() const { return Representation; }
377 
378  /// \brief Extend the current nested-name-specifier by another
379  /// nested-name-specifier component of the form 'type::'.
380  ///
381  /// \param Context The AST context in which this nested-name-specifier
382  /// resides.
383  ///
384  /// \param TemplateKWLoc The location of the 'template' keyword, if present.
385  ///
386  /// \param TL The TypeLoc that describes the type preceding the '::'.
387  ///
388  /// \param ColonColonLoc The location of the trailing '::'.
389  void Extend(ASTContext &Context, SourceLocation TemplateKWLoc, TypeLoc TL,
390  SourceLocation ColonColonLoc);
391 
392  /// \brief Extend the current nested-name-specifier by another
393  /// nested-name-specifier component of the form 'identifier::'.
394  ///
395  /// \param Context The AST context in which this nested-name-specifier
396  /// resides.
397  ///
398  /// \param Identifier The identifier.
399  ///
400  /// \param IdentifierLoc The location of the identifier.
401  ///
402  /// \param ColonColonLoc The location of the trailing '::'.
403  void Extend(ASTContext &Context, IdentifierInfo *Identifier,
405 
406  /// \brief Extend the current nested-name-specifier by another
407  /// nested-name-specifier component of the form 'namespace::'.
408  ///
409  /// \param Context The AST context in which this nested-name-specifier
410  /// resides.
411  ///
412  /// \param Namespace The namespace.
413  ///
414  /// \param NamespaceLoc The location of the namespace name.
415  ///
416  /// \param ColonColonLoc The location of the trailing '::'.
417  void Extend(ASTContext &Context, NamespaceDecl *Namespace,
418  SourceLocation NamespaceLoc, SourceLocation ColonColonLoc);
419 
420  /// \brief Extend the current nested-name-specifier by another
421  /// nested-name-specifier component of the form 'namespace-alias::'.
422  ///
423  /// \param Context The AST context in which this nested-name-specifier
424  /// resides.
425  ///
426  /// \param Alias The namespace alias.
427  ///
428  /// \param AliasLoc The location of the namespace alias
429  /// name.
430  ///
431  /// \param ColonColonLoc The location of the trailing '::'.
432  void Extend(ASTContext &Context, NamespaceAliasDecl *Alias,
433  SourceLocation AliasLoc, SourceLocation ColonColonLoc);
434 
435  /// \brief Turn this (empty) nested-name-specifier into the global
436  /// nested-name-specifier '::'.
437  void MakeGlobal(ASTContext &Context, SourceLocation ColonColonLoc);
438 
439  /// \brief Turns this (empty) nested-name-specifier into '__super'
440  /// nested-name-specifier.
441  ///
442  /// \param Context The AST context in which this nested-name-specifier
443  /// resides.
444  ///
445  /// \param RD The declaration of the class in which nested-name-specifier
446  /// appeared.
447  ///
448  /// \param SuperLoc The location of the '__super' keyword.
449  /// name.
450  ///
451  /// \param ColonColonLoc The location of the trailing '::'.
452  void MakeSuper(ASTContext &Context, CXXRecordDecl *RD,
453  SourceLocation SuperLoc, SourceLocation ColonColonLoc);
454  /// \brief Make a new nested-name-specifier from incomplete source-location
455  /// information.
456  ///
457  /// This routine should be used very, very rarely, in cases where we
458  /// need to synthesize a nested-name-specifier. Most code should instead use
459  /// \c Adopt() with a proper \c NestedNameSpecifierLoc.
460  void MakeTrivial(ASTContext &Context, NestedNameSpecifier *Qualifier,
461  SourceRange R);
462 
463  /// \brief Adopt an existing nested-name-specifier (with source-range
464  /// information).
465  void Adopt(NestedNameSpecifierLoc Other);
466 
467  /// \brief Retrieve the source range covered by this nested-name-specifier.
468  SourceRange getSourceRange() const LLVM_READONLY {
469  return NestedNameSpecifierLoc(Representation, Buffer).getSourceRange();
470  }
471 
472  /// \brief Retrieve a nested-name-specifier with location information,
473  /// copied into the given AST context.
474  ///
475  /// \param Context The context into which this nested-name-specifier will be
476  /// copied.
477  NestedNameSpecifierLoc getWithLocInContext(ASTContext &Context) const;
478 
479  /// \brief Retrieve a nested-name-specifier with location
480  /// information based on the information in this builder.
481  ///
482  /// This loc will contain references to the builder's internal data and may
483  /// be invalidated by any change to the builder.
485  return NestedNameSpecifierLoc(Representation, Buffer);
486  }
487 
488  /// \brief Clear out this builder, and prepare it to build another
489  /// nested-name-specifier with source-location information.
490  void Clear() {
491  Representation = nullptr;
492  BufferSize = 0;
493  }
494 
495  /// \brief Retrieve the underlying buffer.
496  ///
497  /// \returns A pair containing a pointer to the buffer of source-location
498  /// data and the size of the source-location data that resides in that
499  /// buffer.
500  std::pair<char *, unsigned> getBuffer() const {
501  return std::make_pair(Buffer, BufferSize);
502  }
503 };
504 
505 /// Insertion operator for diagnostics. This allows sending
506 /// NestedNameSpecifiers into a diagnostic with <<.
508  NestedNameSpecifier *NNS) {
509  DB.AddTaggedVal(reinterpret_cast<intptr_t>(NNS),
511  return DB;
512 }
513 
514 }
515 
516 #endif
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:1300
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:474
void Profile(llvm::FoldingSetNodeID &ID) const
SourceLocation getLocalBeginLoc() const
Retrieve the location of the beginning of this component of the nested-name-specifier.
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:40
void AddTaggedVal(intptr_t V, DiagnosticsEngine::ArgumentKind Kind) const
Definition: Diagnostic.h:1067
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:128
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:953
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.
NestedNameSpecifierLoc()
Construct an empty nested-name-specifier.
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:13161
void * getOpaqueData() const
Retrieve the opaque pointer that refers to source-location data.
Represents a C++ struct/union/class.
Definition: DeclCXX.h:266
A trivial tuple used to represent a source range.
Represents a C++ namespace alias.
Definition: DeclCXX.h:2882
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.