clang  12.0.0git
TemplateName.h
Go to the documentation of this file.
1 //===- TemplateName.h - C++ Template Name Representation --------*- C++ -*-===//
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 // This file defines the TemplateName interface and subclasses.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CLANG_AST_TEMPLATENAME_H
14 #define LLVM_CLANG_AST_TEMPLATENAME_H
15 
18 #include "clang/Basic/LLVM.h"
19 #include "llvm/ADT/FoldingSet.h"
20 #include "llvm/ADT/PointerIntPair.h"
21 #include "llvm/ADT/PointerUnion.h"
22 #include "llvm/Support/PointerLikeTypeTraits.h"
23 #include <cassert>
24 
25 namespace clang {
26 
27 class ASTContext;
28 class DependentTemplateName;
29 class DiagnosticBuilder;
30 class IdentifierInfo;
31 class NamedDecl;
34 class OverloadedTemplateStorage;
35 class AssumedTemplateStorage;
36 class PartialDiagnostic;
37 struct PrintingPolicy;
38 class QualifiedTemplateName;
39 class SubstTemplateTemplateParmPackStorage;
40 class SubstTemplateTemplateParmStorage;
41 class TemplateArgument;
42 class TemplateDecl;
43 class TemplateTemplateParmDecl;
44 
45 /// Implementation class used to describe either a set of overloaded
46 /// template names or an already-substituted template template parameter pack.
48 protected:
49  enum Kind {
51  Assumed, // defined in DeclarationName.h
54  };
55 
56  struct BitsTag {
57  /// A Kind.
58  unsigned Kind : 2;
59 
60  /// The number of stored templates or template arguments,
61  /// depending on which subclass we have.
62  unsigned Size : 30;
63  };
64 
65  union {
66  struct BitsTag Bits;
68  };
69 
71  Bits.Kind = kind;
72  Bits.Size = size;
73  }
74 
75 public:
76  unsigned size() const { return Bits.Size; }
77 
79  return Bits.Kind == Overloaded
80  ? reinterpret_cast<OverloadedTemplateStorage *>(this)
81  : nullptr;
82  }
83 
85  return Bits.Kind == Assumed
86  ? reinterpret_cast<AssumedTemplateStorage *>(this)
87  : nullptr;
88  }
89 
92  ? reinterpret_cast<SubstTemplateTemplateParmStorage *>(this)
93  : nullptr;
94  }
95 
98  ? reinterpret_cast<SubstTemplateTemplateParmPackStorage *>(this)
99  : nullptr;
100  }
101 };
102 
103 /// A structure for storing the information associated with an
104 /// overloaded template name.
106  friend class ASTContext;
107 
110 
111  NamedDecl **getStorage() {
112  return reinterpret_cast<NamedDecl **>(this + 1);
113  }
114  NamedDecl * const *getStorage() const {
115  return reinterpret_cast<NamedDecl *const *>(this + 1);
116  }
117 
118 public:
119  using iterator = NamedDecl *const *;
120 
121  iterator begin() const { return getStorage(); }
122  iterator end() const { return getStorage() + size(); }
123 
125  return llvm::makeArrayRef(begin(), end());
126  }
127 };
128 
129 /// A structure for storing an already-substituted template template
130 /// parameter pack.
131 ///
132 /// This kind of template names occurs when the parameter pack has been
133 /// provided with a template template argument pack in a context where its
134 /// enclosing pack expansion could not be fully expanded.
136  : public UncommonTemplateNameStorage, public llvm::FoldingSetNode
137 {
139  const TemplateArgument *Arguments;
140 
141 public:
143  unsigned Size,
144  const TemplateArgument *Arguments)
146  Parameter(Parameter), Arguments(Arguments) {}
147 
148  /// Retrieve the template template parameter pack being substituted.
150  return Parameter;
151  }
152 
153  /// Retrieve the template template argument pack with which this
154  /// parameter was substituted.
155  TemplateArgument getArgumentPack() const;
156 
157  void Profile(llvm::FoldingSetNodeID &ID, ASTContext &Context);
158 
159  static void Profile(llvm::FoldingSetNodeID &ID,
160  ASTContext &Context,
161  TemplateTemplateParmDecl *Parameter,
162  const TemplateArgument &ArgPack);
163 };
164 
165 /// Represents a C++ template name within the type system.
166 ///
167 /// A C++ template name refers to a template within the C++ type
168 /// system. In most cases, a template name is simply a reference to a
169 /// class template, e.g.
170 ///
171 /// \code
172 /// template<typename T> class X { };
173 ///
174 /// X<int> xi;
175 /// \endcode
176 ///
177 /// Here, the 'X' in \c X<int> is a template name that refers to the
178 /// declaration of the class template X, above. Template names can
179 /// also refer to function templates, C++0x template aliases, etc.
180 ///
181 /// Some template names are dependent. For example, consider:
182 ///
183 /// \code
184 /// template<typename MetaFun, typename T1, typename T2> struct apply2 {
185 /// typedef typename MetaFun::template apply<T1, T2>::type type;
186 /// };
187 /// \endcode
188 ///
189 /// Here, "apply" is treated as a template name within the typename
190 /// specifier in the typedef. "apply" is a nested template, and can
191 /// only be understood in the context of
193  using StorageType =
194  llvm::PointerUnion<TemplateDecl *, UncommonTemplateNameStorage *,
196 
197  StorageType Storage;
198 
199  explicit TemplateName(void *Ptr);
200 
201 public:
202  // Kind of name that is actually stored.
203  enum NameKind {
204  /// A single template declaration.
206 
207  /// A set of overloaded template declarations.
209 
210  /// An unqualified-id that has been assumed to name a function template
211  /// that will be found by ADL.
213 
214  /// A qualified template name, where the qualification is kept
215  /// to describe the source code as written.
217 
218  /// A dependent template name that has not been resolved to a
219  /// template (or set of templates).
221 
222  /// A template template parameter that has been substituted
223  /// for some other template name.
225 
226  /// A template template parameter pack that has been substituted for
227  /// a template template argument pack, but has not yet been expanded into
228  /// individual arguments.
230  };
231 
232  TemplateName() = default;
233  explicit TemplateName(TemplateDecl *Template);
234  explicit TemplateName(OverloadedTemplateStorage *Storage);
235  explicit TemplateName(AssumedTemplateStorage *Storage);
238  explicit TemplateName(QualifiedTemplateName *Qual);
239  explicit TemplateName(DependentTemplateName *Dep);
240 
241  /// Determine whether this template name is NULL.
242  bool isNull() const;
243 
244  // Get the kind of name that is actually stored.
245  NameKind getKind() const;
246 
247  /// Retrieve the underlying template declaration that
248  /// this template name refers to, if known.
249  ///
250  /// \returns The template declaration that this template name refers
251  /// to, if any. If the template name does not refer to a specific
252  /// declaration because it is a dependent name, or if it refers to a
253  /// set of function templates, returns NULL.
254  TemplateDecl *getAsTemplateDecl() const;
255 
256  /// Retrieve the underlying, overloaded function template
257  /// declarations that this template name refers to, if known.
258  ///
259  /// \returns The set of overloaded function templates that this template
260  /// name refers to, if known. If the template name does not refer to a
261  /// specific set of function templates because it is a dependent name or
262  /// refers to a single template, returns NULL.
263  OverloadedTemplateStorage *getAsOverloadedTemplate() const;
264 
265  /// Retrieve information on a name that has been assumed to be a
266  /// template-name in order to permit a call via ADL.
268 
269  /// Retrieve the substituted template template parameter, if
270  /// known.
271  ///
272  /// \returns The storage for the substituted template template parameter,
273  /// if known. Otherwise, returns NULL.
275 
276  /// Retrieve the substituted template template parameter pack, if
277  /// known.
278  ///
279  /// \returns The storage for the substituted template template parameter pack,
280  /// if known. Otherwise, returns NULL.
283 
284  /// Retrieve the underlying qualified template name
285  /// structure, if any.
286  QualifiedTemplateName *getAsQualifiedTemplateName() const;
287 
288  /// Retrieve the underlying dependent template name
289  /// structure, if any.
290  DependentTemplateName *getAsDependentTemplateName() const;
291 
292  TemplateName getUnderlying() const;
293 
294  /// Get the template name to substitute when this template name is used as a
295  /// template template argument. This refers to the most recent declaration of
296  /// the template, including any default template arguments.
297  TemplateName getNameToSubstitute() const;
298 
299  TemplateNameDependence getDependence() const;
300 
301  /// Determines whether this is a dependent template name.
302  bool isDependent() const;
303 
304  /// Determines whether this is a template name that somehow
305  /// depends on a template parameter.
306  bool isInstantiationDependent() const;
307 
308  /// Determines whether this template name contains an
309  /// unexpanded parameter pack (for C++0x variadic templates).
310  bool containsUnexpandedParameterPack() const;
311 
312  /// Print the template name.
313  ///
314  /// \param OS the output stream to which the template name will be
315  /// printed.
316  ///
317  /// \param SuppressNNS if true, don't print the
318  /// nested-name-specifier that precedes the template name (if it has
319  /// one).
320  void print(raw_ostream &OS, const PrintingPolicy &Policy,
321  bool SuppressNNS = false) const;
322 
323  /// Debugging aid that dumps the template name.
324  void dump(raw_ostream &OS) const;
325 
326  /// Debugging aid that dumps the template name to standard
327  /// error.
328  void dump() const;
329 
330  void Profile(llvm::FoldingSetNodeID &ID) {
331  ID.AddPointer(Storage.getOpaqueValue());
332  }
333 
334  /// Retrieve the template name as a void pointer.
335  void *getAsVoidPointer() const { return Storage.getOpaqueValue(); }
336 
337  /// Build a template name from a void pointer.
338  static TemplateName getFromVoidPointer(void *Ptr) {
339  return TemplateName(Ptr);
340  }
341 };
342 
343 /// Insertion operator for diagnostics. This allows sending TemplateName's
344 /// into a diagnostic with <<.
346  TemplateName N);
348  TemplateName N);
349 
350 /// A structure for storing the information associated with a
351 /// substituted template template parameter.
353  : public UncommonTemplateNameStorage, public llvm::FoldingSetNode {
354  friend class ASTContext;
355 
357  TemplateName Replacement;
358 
360  TemplateName replacement)
362  Parameter(parameter), Replacement(replacement) {}
363 
364 public:
366  TemplateName getReplacement() const { return Replacement; }
367 
368  void Profile(llvm::FoldingSetNodeID &ID);
369 
370  static void Profile(llvm::FoldingSetNodeID &ID,
371  TemplateTemplateParmDecl *parameter,
372  TemplateName replacement);
373 };
374 
378  return subst->getReplacement().getUnderlying();
379  return *this;
380 }
381 
382 /// Represents a template name that was expressed as a
383 /// qualified name.
384 ///
385 /// This kind of template name refers to a template name that was
386 /// preceded by a nested name specifier, e.g., \c std::vector. Here,
387 /// the nested name specifier is "std::" and the template name is the
388 /// declaration for "vector". The QualifiedTemplateName class is only
389 /// used to provide "sugar" for template names that were expressed
390 /// with a qualified name, and has no semantic meaning. In this
391 /// manner, it is to TemplateName what ElaboratedType is to Type,
392 /// providing extra syntactic sugar for downstream clients.
393 class QualifiedTemplateName : public llvm::FoldingSetNode {
394  friend class ASTContext;
395 
396  /// The nested name specifier that qualifies the template name.
397  ///
398  /// The bit is used to indicate whether the "template" keyword was
399  /// present before the template name itself. Note that the
400  /// "template" keyword is always redundant in this case (otherwise,
401  /// the template name would be a dependent name and we would express
402  /// this name with DependentTemplateName).
403  llvm::PointerIntPair<NestedNameSpecifier *, 1> Qualifier;
404 
405  /// The template declaration or set of overloaded function templates
406  /// that this qualified name refers to.
407  TemplateDecl *Template;
408 
409  QualifiedTemplateName(NestedNameSpecifier *NNS, bool TemplateKeyword,
410  TemplateDecl *Template)
411  : Qualifier(NNS, TemplateKeyword? 1 : 0), Template(Template) {}
412 
413 public:
414  /// Return the nested name specifier that qualifies this name.
415  NestedNameSpecifier *getQualifier() const { return Qualifier.getPointer(); }
416 
417  /// Whether the template name was prefixed by the "template"
418  /// keyword.
419  bool hasTemplateKeyword() const { return Qualifier.getInt(); }
420 
421  /// The template declaration that this qualified name refers
422  /// to.
423  TemplateDecl *getDecl() const { return Template; }
424 
425  /// The template declaration to which this qualified name
426  /// refers.
427  TemplateDecl *getTemplateDecl() const { return Template; }
428 
429  void Profile(llvm::FoldingSetNodeID &ID) {
430  Profile(ID, getQualifier(), hasTemplateKeyword(), getTemplateDecl());
431  }
432 
433  static void Profile(llvm::FoldingSetNodeID &ID, NestedNameSpecifier *NNS,
434  bool TemplateKeyword, TemplateDecl *Template) {
435  ID.AddPointer(NNS);
436  ID.AddBoolean(TemplateKeyword);
437  ID.AddPointer(Template);
438  }
439 };
440 
441 /// Represents a dependent template name that cannot be
442 /// resolved prior to template instantiation.
443 ///
444 /// This kind of template name refers to a dependent template name,
445 /// including its nested name specifier (if any). For example,
446 /// DependentTemplateName can refer to "MetaFun::template apply",
447 /// where "MetaFun::" is the nested name specifier and "apply" is the
448 /// template name referenced. The "template" keyword is implied.
449 class DependentTemplateName : public llvm::FoldingSetNode {
450  friend class ASTContext;
451 
452  /// The nested name specifier that qualifies the template
453  /// name.
454  ///
455  /// The bit stored in this qualifier describes whether the \c Name field
456  /// is interpreted as an IdentifierInfo pointer (when clear) or as an
457  /// overloaded operator kind (when set).
458  llvm::PointerIntPair<NestedNameSpecifier *, 1, bool> Qualifier;
459 
460  /// The dependent template name.
461  union {
462  /// The identifier template name.
463  ///
464  /// Only valid when the bit on \c Qualifier is clear.
466 
467  /// The overloaded operator name.
468  ///
469  /// Only valid when the bit on \c Qualifier is set.
471  };
472 
473  /// The canonical template name to which this dependent
474  /// template name refers.
475  ///
476  /// The canonical template name for a dependent template name is
477  /// another dependent template name whose nested name specifier is
478  /// canonical.
479  TemplateName CanonicalTemplateName;
480 
482  const IdentifierInfo *Identifier)
483  : Qualifier(Qualifier, false), Identifier(Identifier),
484  CanonicalTemplateName(this) {}
485 
487  const IdentifierInfo *Identifier,
488  TemplateName Canon)
489  : Qualifier(Qualifier, false), Identifier(Identifier),
490  CanonicalTemplateName(Canon) {}
491 
493  OverloadedOperatorKind Operator)
494  : Qualifier(Qualifier, true), Operator(Operator),
495  CanonicalTemplateName(this) {}
496 
498  OverloadedOperatorKind Operator,
499  TemplateName Canon)
500  : Qualifier(Qualifier, true), Operator(Operator),
501  CanonicalTemplateName(Canon) {}
502 
503 public:
504  /// Return the nested name specifier that qualifies this name.
505  NestedNameSpecifier *getQualifier() const { return Qualifier.getPointer(); }
506 
507  /// Determine whether this template name refers to an identifier.
508  bool isIdentifier() const { return !Qualifier.getInt(); }
509 
510  /// Returns the identifier to which this template name refers.
511  const IdentifierInfo *getIdentifier() const {
512  assert(isIdentifier() && "Template name isn't an identifier?");
513  return Identifier;
514  }
515 
516  /// Determine whether this template name refers to an overloaded
517  /// operator.
518  bool isOverloadedOperator() const { return Qualifier.getInt(); }
519 
520  /// Return the overloaded operator to which this template name refers.
522  assert(isOverloadedOperator() &&
523  "Template name isn't an overloaded operator?");
524  return Operator;
525  }
526 
527  void Profile(llvm::FoldingSetNodeID &ID) {
528  if (isIdentifier())
529  Profile(ID, getQualifier(), getIdentifier());
530  else
531  Profile(ID, getQualifier(), getOperator());
532  }
533 
534  static void Profile(llvm::FoldingSetNodeID &ID, NestedNameSpecifier *NNS,
535  const IdentifierInfo *Identifier) {
536  ID.AddPointer(NNS);
537  ID.AddBoolean(false);
538  ID.AddPointer(Identifier);
539  }
540 
541  static void Profile(llvm::FoldingSetNodeID &ID, NestedNameSpecifier *NNS,
542  OverloadedOperatorKind Operator) {
543  ID.AddPointer(NNS);
544  ID.AddBoolean(true);
545  ID.AddInteger(Operator);
546  }
547 };
548 
549 } // namespace clang.
550 
551 namespace llvm {
552 
553 /// The clang::TemplateName class is effectively a pointer.
554 template<>
555 struct PointerLikeTypeTraits<clang::TemplateName> {
556  static inline void *getAsVoidPointer(clang::TemplateName TN) {
557  return TN.getAsVoidPointer();
558  }
559 
560  static inline clang::TemplateName getFromVoidPointer(void *Ptr) {
562  }
563 
564  // No bits are available!
565  static constexpr int NumLowBitsAvailable = 0;
566 };
567 
568 } // namespace llvm.
569 
570 #endif // LLVM_CLANG_AST_TEMPLATENAME_H
TemplateTemplateParmDecl * getParameterPack() const
Retrieve the template template parameter pack being substituted.
Definition: TemplateName.h:149
static llvm::GlobalValue::DLLStorageClassTypes getStorage(CodeGenModule &CGM, StringRef Name)
Definition: CGObjCMac.cpp:6515
StringRef Identifier
Definition: Format.cpp:2026
void * getAsVoidPointer() const
Retrieve the template name as a void pointer.
Definition: TemplateName.h:335
bool hasTemplateKeyword() const
Whether the template name was prefixed by the "template" keyword.
Definition: TemplateName.h:419
OverloadedOperatorKind getOperator() const
Return the overloaded operator to which this template name refers.
Definition: TemplateName.h:521
NestedNameSpecifier * getQualifier() const
Return the nested name specifier that qualifies this name.
Definition: TemplateName.h:505
Specialize PointerLikeTypeTraits to allow LazyGenerationalUpdatePtr to be placed into a PointerUnion...
Definition: Dominators.h:30
unsigned Size
The number of stored templates or template arguments, depending on which subclass we have...
Definition: TemplateName.h:62
A template template parameter that has been substituted for some other template name.
Definition: TemplateName.h:224
const IdentifierInfo * getIdentifier() const
Returns the identifier to which this template name refers.
Definition: TemplateName.h:511
Describes how types, statements, expressions, and declarations should be printed. ...
Definition: PrettyPrinter.h:49
void print(llvm::raw_ostream &OS, const Pointer &P, ASTContext &Ctx, QualType Ty)
Definition: InterpFrame.cpp:62
One of these records is kept for each identifier that is lexed.
TemplateName getUnderlying() const
Definition: TemplateName.h:375
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:174
Represents a dependent template name that cannot be resolved prior to template instantiation.
Definition: TemplateName.h:449
SubstTemplateTemplateParmStorage * getAsSubstTemplateTemplateParm()
Definition: TemplateName.h:90
A qualified template name, where the qualification is kept to describe the source code as written...
Definition: TemplateName.h:216
__device__ int
static void dump(llvm::raw_ostream &OS, StringRef FunctionName, ArrayRef< CounterExpression > Expressions, ArrayRef< CounterMappingRegion > Regions)
Forward-declares and imports various common LLVM datatypes that clang wants to use unqualified...
An unqualified-id that has been assumed to name a function template that will be found by ADL...
Definition: TemplateName.h:212
SubstTemplateTemplateParmPackStorage * getAsSubstTemplateTemplateParmPack()
Definition: TemplateName.h:96
TemplateTemplateParmDecl * getParameter() const
Definition: TemplateName.h:365
void Profile(llvm::FoldingSetNodeID &ID)
Definition: TemplateName.h:527
A little helper class used to produce diagnostics.
Definition: Diagnostic.h:1062
A dependent template name that has not been resolved to a template (or set of templates).
Definition: TemplateName.h:220
TemplateDecl * getTemplateDecl() const
The template declaration to which this qualified name refers.
Definition: TemplateName.h:427
OverloadedOperatorKind Operator
The overloaded operator name.
Definition: TemplateName.h:470
static void Profile(llvm::FoldingSetNodeID &ID, NestedNameSpecifier *NNS, OverloadedOperatorKind Operator)
Definition: TemplateName.h:541
A structure for storing the information associated with a substituted template template parameter...
Definition: TemplateName.h:352
Represents a C++ template name within the type system.
Definition: TemplateName.h:192
bool isIdentifier() const
Determine whether this template name refers to an identifier.
Definition: TemplateName.h:508
static void Profile(llvm::FoldingSetNodeID &ID, NestedNameSpecifier *NNS, const IdentifierInfo *Identifier)
Definition: TemplateName.h:534
static void Profile(llvm::FoldingSetNodeID &ID, NestedNameSpecifier *NNS, bool TemplateKeyword, TemplateDecl *Template)
Definition: TemplateName.h:433
TemplateTemplateParmDecl - Declares a template template parameter, e.g., "T" in.
static StringRef getIdentifier(const Token &Tok)
NestedNameSpecifier * getQualifier() const
Return the nested name specifier that qualifies this name.
Definition: TemplateName.h:415
OverloadedTemplateStorage * getAsOverloadedStorage()
Definition: TemplateName.h:78
static TemplateName getFromVoidPointer(void *Ptr)
Build a template name from a void pointer.
Definition: TemplateName.h:338
#define false
Definition: stdbool.h:17
A structure for storing an already-substituted template template parameter pack.
Definition: TemplateName.h:135
void Profile(llvm::FoldingSetNodeID &ID)
Definition: TemplateName.h:429
static void * getAsVoidPointer(clang::TemplateName TN)
Definition: TemplateName.h:556
Represents a C++ nested name specifier, such as "\::std::vector<int>::".
bool isOverloadedOperator() const
Determine whether this template name refers to an overloaded operator.
Definition: TemplateName.h:518
UncommonTemplateNameStorage(Kind kind, unsigned size)
Definition: TemplateName.h:70
void Profile(llvm::FoldingSetNodeID &ID)
Definition: TemplateName.h:330
static clang::TemplateName getFromVoidPointer(void *Ptr)
Definition: TemplateName.h:560
llvm::ArrayRef< NamedDecl * > decls() const
Definition: TemplateName.h:124
Represents a template argument.
Definition: TemplateBase.h:51
Represents a template name that was expressed as a qualified name.
Definition: TemplateName.h:393
Dataflow Directional Tag Classes.
AssumedTemplateStorage * getAsAssumedTemplateName()
Definition: TemplateName.h:84
const DiagnosticBuilder & operator<<(const DiagnosticBuilder &DB, const ASTContext::SectionInfo &Section)
Insertion operator for diagnostics.
The base class of all kinds of template declarations (e.g., class, function, etc.).
Definition: DeclTemplate.h:402
OverloadedOperatorKind
Enumeration specifying the different kinds of C++ overloaded operators.
Definition: OperatorKinds.h:21
SubstTemplateTemplateParmPackStorage(TemplateTemplateParmDecl *Parameter, unsigned Size, const TemplateArgument *Arguments)
Definition: TemplateName.h:142
const IdentifierInfo * Identifier
The identifier template name.
Definition: TemplateName.h:465
The parameter type of a method or function.
A structure for storing the information associated with an overloaded template name.
Definition: TemplateName.h:105
A structure for storing the information associated with a name that has been assumed to be a template...
unsigned kind
All of the diagnostics that can be emitted by the frontend.
Definition: DiagnosticIDs.h:60
static Decl::Kind getKind(const Decl *D)
Definition: DeclBase.cpp:996
TemplateDecl * getDecl() const
The template declaration that this qualified name refers to.
Definition: TemplateName.h:423
A set of overloaded template declarations.
Definition: TemplateName.h:208
This represents a decl that may have a name.
Definition: Decl.h:223
Implementation class used to describe either a set of overloaded template names or an already-substit...
Definition: TemplateName.h:47
A single template declaration.
Definition: TemplateName.h:205