1 //===--- TemplateName.h - C++ Template Name Representation-------*- 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 TemplateName interface and subclasses. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_CLANG_AST_TEMPLATENAME_H 15 #define LLVM_CLANG_AST_TEMPLATENAME_H 16 17 #include "clang/Basic/LLVM.h" 18 #include "llvm/ADT/FoldingSet.h" 19 #include "llvm/ADT/PointerUnion.h" 20 #include "clang/Basic/OperatorKinds.h" 21 22 namespace clang { 23 24 class ASTContext; 25 class DependentTemplateName; 26 class DiagnosticBuilder; 27 class IdentifierInfo; 28 class NestedNameSpecifier; 29 class OverloadedTemplateStorage; 30 struct PrintingPolicy; 31 class QualifiedTemplateName; 32 class NamedDecl; 33 class SubstTemplateTemplateParmStorage; 34 class SubstTemplateTemplateParmPackStorage; 35 class TemplateArgument; 36 class TemplateDecl; 37 class TemplateTemplateParmDecl; 38 39 /// \brief Implementation class used to describe either a set of overloaded 40 /// template names or an already-substituted template template parameter pack. 41 class UncommonTemplateNameStorage { 42 protected: 43 enum Kind { 44 Overloaded, 45 SubstTemplateTemplateParm, 46 SubstTemplateTemplateParmPack 47 }; 48 49 union { 50 struct { 51 /// \brief A Kind. 52 unsigned Kind : 2; 53 54 /// \brief The number of stored templates or template arguments, 55 /// depending on which subclass we have. 56 unsigned Size : 30; 57 } Bits; 58 59 void *PointerAlignment; 60 }; 61 62 UncommonTemplateNameStorage(Kind kind, unsigned size) { 63 Bits.Kind = kind; 64 Bits.Size = size; 65 } 66 67 public: 68 unsigned size() const { return Bits.Size; } 69 70 OverloadedTemplateStorage *getAsOverloadedStorage() { 71 return Bits.Kind == Overloaded 72 ? reinterpret_cast<OverloadedTemplateStorage *>(this) 73 : 0; 74 } 75 76 SubstTemplateTemplateParmStorage *getAsSubstTemplateTemplateParm() { 77 return Bits.Kind == SubstTemplateTemplateParm 78 ? reinterpret_cast<SubstTemplateTemplateParmStorage *>(this) 79 : 0; 80 } 81 82 SubstTemplateTemplateParmPackStorage *getAsSubstTemplateTemplateParmPack() { 83 return Bits.Kind == SubstTemplateTemplateParmPack 84 ? reinterpret_cast<SubstTemplateTemplateParmPackStorage *>(this) 85 : 0; 86 } 87 }; 88 89 /// \brief A structure for storing the information associated with an 90 /// overloaded template name. 91 class OverloadedTemplateStorage : public UncommonTemplateNameStorage { 92 friend class ASTContext; 93 94 OverloadedTemplateStorage(unsigned size) 95 : UncommonTemplateNameStorage(Overloaded, size) { } 96 97 NamedDecl **getStorage() { 98 return reinterpret_cast<NamedDecl **>(this + 1); 99 } 100 NamedDecl * const *getStorage() const { 101 return reinterpret_cast<NamedDecl *const *>(this + 1); 102 } 103 104 public: 105 typedef NamedDecl *const *iterator; 106 107 iterator begin() const { return getStorage(); } 108 iterator end() const { return getStorage() + size(); } 109 }; 110 111 /// \brief A structure for storing an already-substituted template template 112 /// parameter pack. 113 /// 114 /// This kind of template names occurs when the parameter pack has been 115 /// provided with a template template argument pack in a context where its 116 /// enclosing pack expansion could not be fully expanded. 117 class SubstTemplateTemplateParmPackStorage 118 : public UncommonTemplateNameStorage, public llvm::FoldingSetNode 119 { 120 TemplateTemplateParmDecl *Parameter; 121 const TemplateArgument *Arguments; 122 123 public: 124 SubstTemplateTemplateParmPackStorage(TemplateTemplateParmDecl *Parameter, 125 unsigned Size, 126 const TemplateArgument *Arguments) 127 : UncommonTemplateNameStorage(SubstTemplateTemplateParmPack, Size), 128 Parameter(Parameter), Arguments(Arguments) { } 129 130 /// \brief Retrieve the template template parameter pack being substituted. 131 TemplateTemplateParmDecl *getParameterPack() const { 132 return Parameter; 133 } 134 135 /// \brief Retrieve the template template argument pack with which this 136 /// parameter was substituted. 137 TemplateArgument getArgumentPack() const; 138 139 void Profile(llvm::FoldingSetNodeID &ID, ASTContext &Context); 140 141 static void Profile(llvm::FoldingSetNodeID &ID, 142 ASTContext &Context, 143 TemplateTemplateParmDecl *Parameter, 144 const TemplateArgument &ArgPack); 145 }; 146 147 /// \brief Represents a C++ template name within the type system. 148 /// 149 /// A C++ template name refers to a template within the C++ type 150 /// system. In most cases, a template name is simply a reference to a 151 /// class template, e.g. 152 /// 153 /// \code 154 /// template<typename T> class X { }; 155 /// 156 /// X<int> xi; 157 /// \endcode 158 /// 159 /// Here, the 'X' in \c X<int> is a template name that refers to the 160 /// declaration of the class template X, above. Template names can 161 /// also refer to function templates, C++0x template aliases, etc. 162 /// 163 /// Some template names are dependent. For example, consider: 164 /// 165 /// \code 166 /// template<typename MetaFun, typename T1, typename T2> struct apply2 { 167 /// typedef typename MetaFun::template apply<T1, T2>::type type; 168 /// }; 169 /// \endcode 170 /// 171 /// Here, "apply" is treated as a template name within the typename 172 /// specifier in the typedef. "apply" is a nested template, and can 173 /// only be understood in the context of 174 class TemplateName { 175 typedef llvm::PointerUnion4<TemplateDecl *, 176 UncommonTemplateNameStorage *, 177 QualifiedTemplateName *, 178 DependentTemplateName *> StorageType; 179 180 StorageType Storage; 181 182 explicit TemplateName(void *Ptr) { 183 Storage = StorageType::getFromOpaqueValue(Ptr); 184 } 185 186 public: 187 // \brief Kind of name that is actually stored. 188 enum NameKind { 189 /// \brief A single template declaration. 190 Template, 191 /// \brief A set of overloaded template declarations. 192 OverloadedTemplate, 193 /// \brief A qualified template name, where the qualification is kept 194 /// to describe the source code as written. 195 QualifiedTemplate, 196 /// \brief A dependent template name that has not been resolved to a 197 /// template (or set of templates). 198 DependentTemplate, 199 /// \brief A template template parameter that has been substituted 200 /// for some other template name. 201 SubstTemplateTemplateParm, 202 /// \brief A template template parameter pack that has been substituted for 203 /// a template template argument pack, but has not yet been expanded into 204 /// individual arguments. 205 SubstTemplateTemplateParmPack 206 }; 207 208 TemplateName() : Storage() { } 209 explicit TemplateName(TemplateDecl *Template) : Storage(Template) { } 210 explicit TemplateName(OverloadedTemplateStorage *Storage) 211 : Storage(Storage) { } 212 explicit TemplateName(SubstTemplateTemplateParmStorage *Storage); 213 explicit TemplateName(SubstTemplateTemplateParmPackStorage *Storage) 214 : Storage(Storage) { } 215 explicit TemplateName(QualifiedTemplateName *Qual) : Storage(Qual) { } 216 explicit TemplateName(DependentTemplateName *Dep) : Storage(Dep) { } 217 218 /// \brief Determine whether this template name is NULL. 219 bool isNull() const { return Storage.isNull(); } 220 221 // \brief Get the kind of name that is actually stored. 222 NameKind getKind() const; 223 224 /// \brief Retrieve the underlying template declaration that 225 /// this template name refers to, if known. 226 /// 227 /// \returns The template declaration that this template name refers 228 /// to, if any. If the template name does not refer to a specific 229 /// declaration because it is a dependent name, or if it refers to a 230 /// set of function templates, returns NULL. 231 TemplateDecl *getAsTemplateDecl() const; 232 233 /// \brief Retrieve the underlying, overloaded function template 234 // declarations that this template name refers to, if known. 235 /// 236 /// \returns The set of overloaded function templates that this template 237 /// name refers to, if known. If the template name does not refer to a 238 /// specific set of function templates because it is a dependent name or 239 /// refers to a single template, returns NULL. 240 OverloadedTemplateStorage *getAsOverloadedTemplate() const { 241 if (UncommonTemplateNameStorage *Uncommon = 242 Storage.dyn_cast<UncommonTemplateNameStorage *>()) 243 return Uncommon->getAsOverloadedStorage(); 244 245 return 0; 246 } 247 248 /// \brief Retrieve the substituted template template parameter, if 249 /// known. 250 /// 251 /// \returns The storage for the substituted template template parameter, 252 /// if known. Otherwise, returns NULL. 253 SubstTemplateTemplateParmStorage *getAsSubstTemplateTemplateParm() const { 254 if (UncommonTemplateNameStorage *uncommon = 255 Storage.dyn_cast<UncommonTemplateNameStorage *>()) 256 return uncommon->getAsSubstTemplateTemplateParm(); 257 258 return 0; 259 } 260 261 /// \brief Retrieve the substituted template template parameter pack, if 262 /// known. 263 /// 264 /// \returns The storage for the substituted template template parameter pack, 265 /// if known. Otherwise, returns NULL. 266 SubstTemplateTemplateParmPackStorage * 267 getAsSubstTemplateTemplateParmPack() const { 268 if (UncommonTemplateNameStorage *Uncommon = 269 Storage.dyn_cast<UncommonTemplateNameStorage *>()) 270 return Uncommon->getAsSubstTemplateTemplateParmPack(); 271 272 return 0; 273 } 274 275 /// \brief Retrieve the underlying qualified template name 276 /// structure, if any. 277 QualifiedTemplateName *getAsQualifiedTemplateName() const { 278 return Storage.dyn_cast<QualifiedTemplateName *>(); 279 } 280 281 /// \brief Retrieve the underlying dependent template name 282 /// structure, if any. 283 DependentTemplateName *getAsDependentTemplateName() const { 284 return Storage.dyn_cast<DependentTemplateName *>(); 285 } 286 287 TemplateName getUnderlying() const; 288 289 /// \brief Determines whether this is a dependent template name. 290 bool isDependent() const; 291 292 /// \brief Determines whether this is a template name that somehow 293 /// depends on a template parameter. 294 bool isInstantiationDependent() const; 295 296 /// \brief Determines whether this template name contains an 297 /// unexpanded parameter pack (for C++0x variadic templates). 298 bool containsUnexpandedParameterPack() const; 299 300 /// \brief Print the template name. 301 /// 302 /// \param OS the output stream to which the template name will be 303 /// printed. 304 /// 305 /// \param SuppressNNS if true, don't print the 306 /// nested-name-specifier that precedes the template name (if it has 307 /// one). 308 void print(raw_ostream &OS, const PrintingPolicy &Policy, 309 bool SuppressNNS = false) const; 310 311 /// \brief Debugging aid that dumps the template name to standard 312 /// error. 313 void dump() const; 314 315 void Profile(llvm::FoldingSetNodeID &ID) { 316 ID.AddPointer(Storage.getOpaqueValue()); 317 } 318 319 /// \brief Retrieve the template name as a void pointer. 320 void *getAsVoidPointer() const { return Storage.getOpaqueValue(); } 321 322 /// \brief Build a template name from a void pointer. 323 static TemplateName getFromVoidPointer(void *Ptr) { 324 return TemplateName(Ptr); 325 } 326 }; 327 328 /// Insertion operator for diagnostics. This allows sending TemplateName's 329 /// into a diagnostic with <<. 330 const DiagnosticBuilder &operator<<(const DiagnosticBuilder &DB, 331 TemplateName N); 332 333 /// \brief A structure for storing the information associated with a 334 /// substituted template template parameter. 335 class SubstTemplateTemplateParmStorage 336 : public UncommonTemplateNameStorage, public llvm::FoldingSetNode { 337 friend class ASTContext; 338 339 TemplateTemplateParmDecl *Parameter; 340 TemplateName Replacement; 341 342 SubstTemplateTemplateParmStorage(TemplateTemplateParmDecl *parameter, 343 TemplateName replacement) 344 : UncommonTemplateNameStorage(SubstTemplateTemplateParm, 0), 345 Parameter(parameter), Replacement(replacement) {} 346 347 public: 348 TemplateTemplateParmDecl *getParameter() const { return Parameter; } 349 TemplateName getReplacement() const { return Replacement; } 350 351 void Profile(llvm::FoldingSetNodeID &ID); 352 353 static void Profile(llvm::FoldingSetNodeID &ID, 354 TemplateTemplateParmDecl *parameter, 355 TemplateName replacement); 356 }; 357 358 inline TemplateName::TemplateName(SubstTemplateTemplateParmStorage *Storage) 359 : Storage(Storage) { } 360 361 inline TemplateName TemplateName::getUnderlying() const { 362 if (SubstTemplateTemplateParmStorage *subst 363 = getAsSubstTemplateTemplateParm()) 364 return subst->getReplacement().getUnderlying(); 365 return *this; 366 } 367 368 /// \brief Represents a template name that was expressed as a 369 /// qualified name. 370 /// 371 /// This kind of template name refers to a template name that was 372 /// preceded by a nested name specifier, e.g., \c std::vector. Here, 373 /// the nested name specifier is "std::" and the template name is the 374 /// declaration for "vector". The QualifiedTemplateName class is only 375 /// used to provide "sugar" for template names that were expressed 376 /// with a qualified name, and has no semantic meaning. In this 377 /// manner, it is to TemplateName what ElaboratedType is to Type, 378 /// providing extra syntactic sugar for downstream clients. 379 class QualifiedTemplateName : public llvm::FoldingSetNode { 380 /// \brief The nested name specifier that qualifies the template name. 381 /// 382 /// The bit is used to indicate whether the "template" keyword was 383 /// present before the template name itself. Note that the 384 /// "template" keyword is always redundant in this case (otherwise, 385 /// the template name would be a dependent name and we would express 386 /// this name with DependentTemplateName). 387 llvm::PointerIntPair<NestedNameSpecifier *, 1> Qualifier; 388 389 /// \brief The template declaration or set of overloaded function templates 390 /// that this qualified name refers to. 391 TemplateDecl *Template; 392 393 friend class ASTContext; 394 395 QualifiedTemplateName(NestedNameSpecifier *NNS, bool TemplateKeyword, 396 TemplateDecl *Template) 397 : Qualifier(NNS, TemplateKeyword? 1 : 0), 398 Template(Template) { } 399 400 public: 401 /// \brief Return the nested name specifier that qualifies this name. 402 NestedNameSpecifier *getQualifier() const { return Qualifier.getPointer(); } 403 404 /// \brief Whether the template name was prefixed by the "template" 405 /// keyword. 406 bool hasTemplateKeyword() const { return Qualifier.getInt(); } 407 408 /// \brief The template declaration that this qualified name refers 409 /// to. 410 TemplateDecl *getDecl() const { return Template; } 411 412 /// \brief The template declaration to which this qualified name 413 /// refers. 414 TemplateDecl *getTemplateDecl() const { return Template; } 415 416 void Profile(llvm::FoldingSetNodeID &ID) { 417 Profile(ID, getQualifier(), hasTemplateKeyword(), getTemplateDecl()); 418 } 419 420 static void Profile(llvm::FoldingSetNodeID &ID, NestedNameSpecifier *NNS, 421 bool TemplateKeyword, TemplateDecl *Template) { 422 ID.AddPointer(NNS); 423 ID.AddBoolean(TemplateKeyword); 424 ID.AddPointer(Template); 425 } 426 }; 427 428 /// \brief Represents a dependent template name that cannot be 429 /// resolved prior to template instantiation. 430 /// 431 /// This kind of template name refers to a dependent template name, 432 /// including its nested name specifier (if any). For example, 433 /// DependentTemplateName can refer to "MetaFun::template apply", 434 /// where "MetaFun::" is the nested name specifier and "apply" is the 435 /// template name referenced. The "template" keyword is implied. 436 class DependentTemplateName : public llvm::FoldingSetNode { 437 /// \brief The nested name specifier that qualifies the template 438 /// name. 439 /// 440 /// The bit stored in this qualifier describes whether the \c Name field 441 /// is interpreted as an IdentifierInfo pointer (when clear) or as an 442 /// overloaded operator kind (when set). 443 llvm::PointerIntPair<NestedNameSpecifier *, 1, bool> Qualifier; 444 445 /// \brief The dependent template name. 446 union { 447 /// \brief The identifier template name. 448 /// 449 /// Only valid when the bit on \c Qualifier is clear. 450 const IdentifierInfo *Identifier; 451 452 /// \brief The overloaded operator name. 453 /// 454 /// Only valid when the bit on \c Qualifier is set. 455 OverloadedOperatorKind Operator; 456 }; 457 458 /// \brief The canonical template name to which this dependent 459 /// template name refers. 460 /// 461 /// The canonical template name for a dependent template name is 462 /// another dependent template name whose nested name specifier is 463 /// canonical. 464 TemplateName CanonicalTemplateName; 465 466 friend class ASTContext; 467 468 DependentTemplateName(NestedNameSpecifier *Qualifier, 469 const IdentifierInfo *Identifier) 470 : Qualifier(Qualifier, false), Identifier(Identifier), 471 CanonicalTemplateName(this) { } 472 473 DependentTemplateName(NestedNameSpecifier *Qualifier, 474 const IdentifierInfo *Identifier, 475 TemplateName Canon) 476 : Qualifier(Qualifier, false), Identifier(Identifier), 477 CanonicalTemplateName(Canon) { } 478 479 DependentTemplateName(NestedNameSpecifier *Qualifier, 480 OverloadedOperatorKind Operator) 481 : Qualifier(Qualifier, true), Operator(Operator), 482 CanonicalTemplateName(this) { } 483 484 DependentTemplateName(NestedNameSpecifier *Qualifier, 485 OverloadedOperatorKind Operator, 486 TemplateName Canon) 487 : Qualifier(Qualifier, true), Operator(Operator), 488 CanonicalTemplateName(Canon) { } 489 490 public: 491 /// \brief Return the nested name specifier that qualifies this name. 492 NestedNameSpecifier *getQualifier() const { return Qualifier.getPointer(); } 493 494 /// \brief Determine whether this template name refers to an identifier. 495 bool isIdentifier() const { return !Qualifier.getInt(); } 496 497 /// \brief Returns the identifier to which this template name refers. 498 const IdentifierInfo *getIdentifier() const { 499 assert(isIdentifier() && "Template name isn't an identifier?"); 500 return Identifier; 501 } 502 503 /// \brief Determine whether this template name refers to an overloaded 504 /// operator. 505 bool isOverloadedOperator() const { return Qualifier.getInt(); } 506 507 /// \brief Return the overloaded operator to which this template name refers. 508 OverloadedOperatorKind getOperator() const { 509 assert(isOverloadedOperator() && 510 "Template name isn't an overloaded operator?"); 511 return Operator; 512 } 513 514 void Profile(llvm::FoldingSetNodeID &ID) { 515 if (isIdentifier()) 516 Profile(ID, getQualifier(), getIdentifier()); 517 else 518 Profile(ID, getQualifier(), getOperator()); 519 } 520 521 static void Profile(llvm::FoldingSetNodeID &ID, NestedNameSpecifier *NNS, 522 const IdentifierInfo *Identifier) { 523 ID.AddPointer(NNS); 524 ID.AddBoolean(false); 525 ID.AddPointer(Identifier); 526 } 527 528 static void Profile(llvm::FoldingSetNodeID &ID, NestedNameSpecifier *NNS, 529 OverloadedOperatorKind Operator) { 530 ID.AddPointer(NNS); 531 ID.AddBoolean(true); 532 ID.AddInteger(Operator); 533 } 534 }; 535 536 } // end namespace clang. 537 538 namespace llvm { 539 540 /// \brief The clang::TemplateName class is effectively a pointer. 541 template<> 542 class PointerLikeTypeTraits<clang::TemplateName> { 543 public: 544 static inline void *getAsVoidPointer(clang::TemplateName TN) { 545 return TN.getAsVoidPointer(); 546 } 547 548 static inline clang::TemplateName getFromVoidPointer(void *Ptr) { 549 return clang::TemplateName::getFromVoidPointer(Ptr); 550 } 551 552 // No bits are available! 553 enum { NumLowBitsAvailable = 0 }; 554 }; 555 556 } // end namespace llvm. 557 558 #endif 559