1 //===- PreprocessingRecord.h - Record of Preprocessing ----------*- 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 PreprocessingRecord class, which maintains a record 10 // of what occurred during preprocessing. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_CLANG_LEX_PREPROCESSINGRECORD_H 15 #define LLVM_CLANG_LEX_PREPROCESSINGRECORD_H 16 17 #include "clang/Basic/IdentifierTable.h" 18 #include "clang/Basic/LLVM.h" 19 #include "clang/Basic/SourceLocation.h" 20 #include "clang/Lex/PPCallbacks.h" 21 #include "llvm/ADT/DenseMap.h" 22 #include "llvm/ADT/PointerUnion.h" 23 #include "llvm/ADT/StringRef.h" 24 #include "llvm/ADT/iterator.h" 25 #include "llvm/ADT/iterator_range.h" 26 #include "llvm/Support/Allocator.h" 27 #include "llvm/Support/Compiler.h" 28 #include <cassert> 29 #include <cstddef> 30 #include <iterator> 31 #include <optional> 32 #include <utility> 33 #include <vector> 34 35 namespace clang { 36 37 class PreprocessingRecord; 38 39 } // namespace clang 40 41 /// Allocates memory within a Clang preprocessing record. 42 void *operator new(size_t bytes, clang::PreprocessingRecord &PR, 43 unsigned alignment = 8) noexcept; 44 45 /// Frees memory allocated in a Clang preprocessing record. 46 void operator delete(void *ptr, clang::PreprocessingRecord &PR, 47 unsigned) noexcept; 48 49 namespace clang { 50 51 class IdentifierInfo; 52 class MacroInfo; 53 class SourceManager; 54 class Token; 55 56 /// Base class that describes a preprocessed entity, which may be a 57 /// preprocessor directive or macro expansion. 58 class PreprocessedEntity { 59 public: 60 /// The kind of preprocessed entity an object describes. 61 enum EntityKind { 62 /// Indicates a problem trying to load the preprocessed entity. 63 InvalidKind, 64 65 /// A macro expansion. 66 MacroExpansionKind, 67 68 /// \defgroup Preprocessing directives 69 /// @{ 70 71 /// A macro definition. 72 MacroDefinitionKind, 73 74 /// An inclusion directive, such as \c \#include, \c 75 /// \#import, or \c \#include_next. 76 InclusionDirectiveKind, 77 78 /// @} 79 80 FirstPreprocessingDirective = MacroDefinitionKind, 81 LastPreprocessingDirective = InclusionDirectiveKind 82 }; 83 84 private: 85 /// The kind of preprocessed entity that this object describes. 86 EntityKind Kind; 87 88 /// The source range that covers this preprocessed entity. 89 SourceRange Range; 90 91 protected: 92 friend class PreprocessingRecord; 93 94 PreprocessedEntity(EntityKind Kind, SourceRange Range) 95 : Kind(Kind), Range(Range) {} 96 97 public: 98 /// Retrieve the kind of preprocessed entity stored in this object. 99 EntityKind getKind() const { return Kind; } 100 101 /// Retrieve the source range that covers this entire preprocessed 102 /// entity. 103 SourceRange getSourceRange() const LLVM_READONLY { return Range; } 104 105 /// Returns true if there was a problem loading the preprocessed 106 /// entity. 107 bool isInvalid() const { return Kind == InvalidKind; } 108 109 // Only allow allocation of preprocessed entities using the allocator 110 // in PreprocessingRecord or by doing a placement new. 111 void *operator new(size_t bytes, PreprocessingRecord &PR, 112 unsigned alignment = 8) noexcept { 113 return ::operator new(bytes, PR, alignment); 114 } 115 116 void *operator new(size_t bytes, void *mem) noexcept { return mem; } 117 118 void operator delete(void *ptr, PreprocessingRecord &PR, 119 unsigned alignment) noexcept { 120 return ::operator delete(ptr, PR, alignment); 121 } 122 123 void operator delete(void *, std::size_t) noexcept {} 124 void operator delete(void *, void *) noexcept {} 125 126 private: 127 // Make vanilla 'new' and 'delete' illegal for preprocessed entities. 128 void *operator new(size_t bytes) noexcept; 129 void operator delete(void *data) noexcept; 130 }; 131 132 /// Records the presence of a preprocessor directive. 133 class PreprocessingDirective : public PreprocessedEntity { 134 public: 135 PreprocessingDirective(EntityKind Kind, SourceRange Range) 136 : PreprocessedEntity(Kind, Range) {} 137 138 // Implement isa/cast/dyncast/etc. 139 static bool classof(const PreprocessedEntity *PD) { 140 return PD->getKind() >= FirstPreprocessingDirective && 141 PD->getKind() <= LastPreprocessingDirective; 142 } 143 }; 144 145 /// Record the location of a macro definition. 146 class MacroDefinitionRecord : public PreprocessingDirective { 147 /// The name of the macro being defined. 148 const IdentifierInfo *Name; 149 150 public: 151 explicit MacroDefinitionRecord(const IdentifierInfo *Name, 152 SourceRange Range) 153 : PreprocessingDirective(MacroDefinitionKind, Range), Name(Name) {} 154 155 /// Retrieve the name of the macro being defined. 156 const IdentifierInfo *getName() const { return Name; } 157 158 /// Retrieve the location of the macro name in the definition. 159 SourceLocation getLocation() const { return getSourceRange().getBegin(); } 160 161 // Implement isa/cast/dyncast/etc. 162 static bool classof(const PreprocessedEntity *PE) { 163 return PE->getKind() == MacroDefinitionKind; 164 } 165 }; 166 167 /// Records the location of a macro expansion. 168 class MacroExpansion : public PreprocessedEntity { 169 /// The definition of this macro or the name of the macro if it is 170 /// a builtin macro. 171 llvm::PointerUnion<IdentifierInfo *, MacroDefinitionRecord *> NameOrDef; 172 173 public: 174 MacroExpansion(IdentifierInfo *BuiltinName, SourceRange Range) 175 : PreprocessedEntity(MacroExpansionKind, Range), 176 NameOrDef(BuiltinName) {} 177 178 MacroExpansion(MacroDefinitionRecord *Definition, SourceRange Range) 179 : PreprocessedEntity(MacroExpansionKind, Range), NameOrDef(Definition) { 180 } 181 182 /// True if it is a builtin macro. 183 bool isBuiltinMacro() const { return NameOrDef.is<IdentifierInfo *>(); } 184 185 /// The name of the macro being expanded. 186 const IdentifierInfo *getName() const { 187 if (MacroDefinitionRecord *Def = getDefinition()) 188 return Def->getName(); 189 return NameOrDef.get<IdentifierInfo *>(); 190 } 191 192 /// The definition of the macro being expanded. May return null if 193 /// this is a builtin macro. 194 MacroDefinitionRecord *getDefinition() const { 195 return NameOrDef.dyn_cast<MacroDefinitionRecord *>(); 196 } 197 198 // Implement isa/cast/dyncast/etc. 199 static bool classof(const PreprocessedEntity *PE) { 200 return PE->getKind() == MacroExpansionKind; 201 } 202 }; 203 204 /// Record the location of an inclusion directive, such as an 205 /// \c \#include or \c \#import statement. 206 class InclusionDirective : public PreprocessingDirective { 207 public: 208 /// The kind of inclusion directives known to the 209 /// preprocessor. 210 enum InclusionKind { 211 /// An \c \#include directive. 212 Include, 213 214 /// An Objective-C \c \#import directive. 215 Import, 216 217 /// A GNU \c \#include_next directive. 218 IncludeNext, 219 220 /// A Clang \c \#__include_macros directive. 221 IncludeMacros 222 }; 223 224 private: 225 /// The name of the file that was included, as written in 226 /// the source. 227 StringRef FileName; 228 229 /// Whether the file name was in quotation marks; otherwise, it was 230 /// in angle brackets. 231 LLVM_PREFERRED_TYPE(bool) 232 unsigned InQuotes : 1; 233 234 /// The kind of inclusion directive we have. 235 /// 236 /// This is a value of type InclusionKind. 237 LLVM_PREFERRED_TYPE(InclusionKind) 238 unsigned Kind : 2; 239 240 /// Whether the inclusion directive was automatically turned into 241 /// a module import. 242 LLVM_PREFERRED_TYPE(bool) 243 unsigned ImportedModule : 1; 244 245 /// The file that was included. 246 OptionalFileEntryRef File; 247 248 public: 249 InclusionDirective(PreprocessingRecord &PPRec, InclusionKind Kind, 250 StringRef FileName, bool InQuotes, bool ImportedModule, 251 OptionalFileEntryRef File, SourceRange Range); 252 253 /// Determine what kind of inclusion directive this is. 254 InclusionKind getKind() const { return static_cast<InclusionKind>(Kind); } 255 256 /// Retrieve the included file name as it was written in the source. 257 StringRef getFileName() const { return FileName; } 258 259 /// Determine whether the included file name was written in quotes; 260 /// otherwise, it was written in angle brackets. 261 bool wasInQuotes() const { return InQuotes; } 262 263 /// Determine whether the inclusion directive was automatically 264 /// turned into a module import. 265 bool importedModule() const { return ImportedModule; } 266 267 /// Retrieve the file entry for the actual file that was included 268 /// by this directive. 269 OptionalFileEntryRef getFile() const { return File; } 270 271 // Implement isa/cast/dyncast/etc. 272 static bool classof(const PreprocessedEntity *PE) { 273 return PE->getKind() == InclusionDirectiveKind; 274 } 275 }; 276 277 /// An abstract class that should be subclassed by any external source 278 /// of preprocessing record entries. 279 class ExternalPreprocessingRecordSource { 280 public: 281 virtual ~ExternalPreprocessingRecordSource(); 282 283 /// Read a preallocated preprocessed entity from the external source. 284 /// 285 /// \returns null if an error occurred that prevented the preprocessed 286 /// entity from being loaded. 287 virtual PreprocessedEntity *ReadPreprocessedEntity(unsigned Index) = 0; 288 289 /// Returns a pair of [Begin, End) indices of preallocated 290 /// preprocessed entities that \p Range encompasses. 291 virtual std::pair<unsigned, unsigned> 292 findPreprocessedEntitiesInRange(SourceRange Range) = 0; 293 294 /// Optionally returns true or false if the preallocated preprocessed 295 /// entity with index \p Index came from file \p FID. 296 virtual std::optional<bool> isPreprocessedEntityInFileID(unsigned Index, 297 FileID FID) { 298 return std::nullopt; 299 } 300 301 /// Read a preallocated skipped range from the external source. 302 virtual SourceRange ReadSkippedRange(unsigned Index) = 0; 303 }; 304 305 /// A record of the steps taken while preprocessing a source file, 306 /// including the various preprocessing directives processed, macros 307 /// expanded, etc. 308 class PreprocessingRecord : public PPCallbacks { 309 SourceManager &SourceMgr; 310 311 /// Allocator used to store preprocessing objects. 312 llvm::BumpPtrAllocator BumpAlloc; 313 314 /// The set of preprocessed entities in this record, in order they 315 /// were seen. 316 std::vector<PreprocessedEntity *> PreprocessedEntities; 317 318 /// The set of preprocessed entities in this record that have been 319 /// loaded from external sources. 320 /// 321 /// The entries in this vector are loaded lazily from the external source, 322 /// and are referenced by the iterator using negative indices. 323 std::vector<PreprocessedEntity *> LoadedPreprocessedEntities; 324 325 /// The set of ranges that were skipped by the preprocessor, 326 std::vector<SourceRange> SkippedRanges; 327 328 bool SkippedRangesAllLoaded = true; 329 330 /// Global (loaded or local) ID for a preprocessed entity. 331 /// Negative values are used to indicate preprocessed entities 332 /// loaded from the external source while non-negative values are used to 333 /// indicate preprocessed entities introduced by the current preprocessor. 334 /// Value -1 corresponds to element 0 in the loaded entities vector, 335 /// value -2 corresponds to element 1 in the loaded entities vector, etc. 336 /// Value 0 is an invalid value, the index to local entities is 1-based, 337 /// value 1 corresponds to element 0 in the local entities vector, 338 /// value 2 corresponds to element 1 in the local entities vector, etc. 339 class PPEntityID { 340 friend class PreprocessingRecord; 341 342 int ID = 0; 343 344 explicit PPEntityID(int ID) : ID(ID) {} 345 346 public: 347 PPEntityID() = default; 348 }; 349 350 static PPEntityID getPPEntityID(unsigned Index, bool isLoaded) { 351 return isLoaded ? PPEntityID(-int(Index)-1) : PPEntityID(Index+1); 352 } 353 354 /// Mapping from MacroInfo structures to their definitions. 355 llvm::DenseMap<const MacroInfo *, MacroDefinitionRecord *> MacroDefinitions; 356 357 /// External source of preprocessed entities. 358 ExternalPreprocessingRecordSource *ExternalSource = nullptr; 359 360 /// Retrieve the preprocessed entity at the given ID. 361 PreprocessedEntity *getPreprocessedEntity(PPEntityID PPID); 362 363 /// Retrieve the loaded preprocessed entity at the given index. 364 PreprocessedEntity *getLoadedPreprocessedEntity(unsigned Index); 365 366 /// Determine the number of preprocessed entities that were 367 /// loaded (or can be loaded) from an external source. 368 unsigned getNumLoadedPreprocessedEntities() const { 369 return LoadedPreprocessedEntities.size(); 370 } 371 372 /// Returns a pair of [Begin, End) indices of local preprocessed 373 /// entities that \p Range encompasses. 374 std::pair<unsigned, unsigned> 375 findLocalPreprocessedEntitiesInRange(SourceRange Range) const; 376 unsigned findBeginLocalPreprocessedEntity(SourceLocation Loc) const; 377 unsigned findEndLocalPreprocessedEntity(SourceLocation Loc) const; 378 379 /// Allocate space for a new set of loaded preprocessed entities. 380 /// 381 /// \returns The index into the set of loaded preprocessed entities, which 382 /// corresponds to the first newly-allocated entity. 383 unsigned allocateLoadedEntities(unsigned NumEntities); 384 385 /// Allocate space for a new set of loaded preprocessed skipped 386 /// ranges. 387 /// 388 /// \returns The index into the set of loaded preprocessed ranges, which 389 /// corresponds to the first newly-allocated range. 390 unsigned allocateSkippedRanges(unsigned NumRanges); 391 392 /// Ensures that all external skipped ranges have been loaded. 393 void ensureSkippedRangesLoaded(); 394 395 /// Register a new macro definition. 396 void RegisterMacroDefinition(MacroInfo *Macro, MacroDefinitionRecord *Def); 397 398 public: 399 /// Construct a new preprocessing record. 400 explicit PreprocessingRecord(SourceManager &SM); 401 402 /// Allocate memory in the preprocessing record. 403 void *Allocate(unsigned Size, unsigned Align = 8) { 404 return BumpAlloc.Allocate(Size, Align); 405 } 406 407 /// Deallocate memory in the preprocessing record. 408 void Deallocate(void *Ptr) {} 409 410 size_t getTotalMemory() const; 411 412 SourceManager &getSourceManager() const { return SourceMgr; } 413 414 /// Iteration over the preprocessed entities. 415 /// 416 /// In a complete iteration, the iterator walks the range [-M, N), 417 /// where negative values are used to indicate preprocessed entities 418 /// loaded from the external source while non-negative values are used to 419 /// indicate preprocessed entities introduced by the current preprocessor. 420 /// However, to provide iteration in source order (for, e.g., chained 421 /// precompiled headers), dereferencing the iterator flips the negative 422 /// values (corresponding to loaded entities), so that position -M 423 /// corresponds to element 0 in the loaded entities vector, position -M+1 424 /// corresponds to element 1 in the loaded entities vector, etc. This 425 /// gives us a reasonably efficient, source-order walk. 426 /// 427 /// We define this as a wrapping iterator around an int. The 428 /// iterator_adaptor_base class forwards the iterator methods to basic 429 /// integer arithmetic. 430 class iterator : public llvm::iterator_adaptor_base< 431 iterator, int, std::random_access_iterator_tag, 432 PreprocessedEntity *, int, PreprocessedEntity *, 433 PreprocessedEntity *> { 434 friend class PreprocessingRecord; 435 436 PreprocessingRecord *Self; 437 438 iterator(PreprocessingRecord *Self, int Position) 439 : iterator::iterator_adaptor_base(Position), Self(Self) {} 440 441 public: 442 iterator() : iterator(nullptr, 0) {} 443 444 PreprocessedEntity *operator*() const { 445 bool isLoaded = this->I < 0; 446 unsigned Index = isLoaded ? 447 Self->LoadedPreprocessedEntities.size() + this->I : this->I; 448 PPEntityID ID = Self->getPPEntityID(Index, isLoaded); 449 return Self->getPreprocessedEntity(ID); 450 } 451 PreprocessedEntity *operator->() const { return **this; } 452 }; 453 454 /// Begin iterator for all preprocessed entities. 455 iterator begin() { 456 return iterator(this, -(int)LoadedPreprocessedEntities.size()); 457 } 458 459 /// End iterator for all preprocessed entities. 460 iterator end() { 461 return iterator(this, PreprocessedEntities.size()); 462 } 463 464 /// Begin iterator for local, non-loaded, preprocessed entities. 465 iterator local_begin() { 466 return iterator(this, 0); 467 } 468 469 /// End iterator for local, non-loaded, preprocessed entities. 470 iterator local_end() { 471 return iterator(this, PreprocessedEntities.size()); 472 } 473 474 /// iterator range for the given range of loaded 475 /// preprocessed entities. 476 llvm::iterator_range<iterator> getIteratorsForLoadedRange(unsigned start, 477 unsigned count) { 478 unsigned end = start + count; 479 assert(end <= LoadedPreprocessedEntities.size()); 480 return llvm::make_range( 481 iterator(this, int(start) - LoadedPreprocessedEntities.size()), 482 iterator(this, int(end) - LoadedPreprocessedEntities.size())); 483 } 484 485 /// Returns a range of preprocessed entities that source range \p R 486 /// encompasses. 487 /// 488 /// \param R the range to look for preprocessed entities. 489 llvm::iterator_range<iterator> 490 getPreprocessedEntitiesInRange(SourceRange R); 491 492 /// Returns true if the preprocessed entity that \p PPEI iterator 493 /// points to is coming from the file \p FID. 494 /// 495 /// Can be used to avoid implicit deserializations of preallocated 496 /// preprocessed entities if we only care about entities of a specific file 497 /// and not from files \#included in the range given at 498 /// \see getPreprocessedEntitiesInRange. 499 bool isEntityInFileID(iterator PPEI, FileID FID); 500 501 /// Add a new preprocessed entity to this record. 502 PPEntityID addPreprocessedEntity(PreprocessedEntity *Entity); 503 504 /// Set the external source for preprocessed entities. 505 void SetExternalSource(ExternalPreprocessingRecordSource &Source); 506 507 /// Retrieve the external source for preprocessed entities. 508 ExternalPreprocessingRecordSource *getExternalSource() const { 509 return ExternalSource; 510 } 511 512 /// Retrieve the macro definition that corresponds to the given 513 /// \c MacroInfo. 514 MacroDefinitionRecord *findMacroDefinition(const MacroInfo *MI); 515 516 /// Retrieve all ranges that got skipped while preprocessing. 517 const std::vector<SourceRange> &getSkippedRanges() { 518 ensureSkippedRangesLoaded(); 519 return SkippedRanges; 520 } 521 522 private: 523 friend class ASTReader; 524 friend class ASTWriter; 525 526 void MacroExpands(const Token &Id, const MacroDefinition &MD, 527 SourceRange Range, const MacroArgs *Args) override; 528 void MacroDefined(const Token &Id, const MacroDirective *MD) override; 529 void MacroUndefined(const Token &Id, const MacroDefinition &MD, 530 const MacroDirective *Undef) override; 531 void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok, 532 StringRef FileName, bool IsAngled, 533 CharSourceRange FilenameRange, 534 OptionalFileEntryRef File, StringRef SearchPath, 535 StringRef RelativePath, 536 const Module *SuggestedModule, bool ModuleImported, 537 SrcMgr::CharacteristicKind FileType) override; 538 void Ifdef(SourceLocation Loc, const Token &MacroNameTok, 539 const MacroDefinition &MD) override; 540 void Ifndef(SourceLocation Loc, const Token &MacroNameTok, 541 const MacroDefinition &MD) override; 542 543 using PPCallbacks::Elifdef; 544 using PPCallbacks::Elifndef; 545 void Elifdef(SourceLocation Loc, const Token &MacroNameTok, 546 const MacroDefinition &MD) override; 547 void Elifndef(SourceLocation Loc, const Token &MacroNameTok, 548 const MacroDefinition &MD) override; 549 550 /// Hook called whenever the 'defined' operator is seen. 551 void Defined(const Token &MacroNameTok, const MacroDefinition &MD, 552 SourceRange Range) override; 553 554 void SourceRangeSkipped(SourceRange Range, 555 SourceLocation EndifLoc) override; 556 557 void addMacroExpansion(const Token &Id, const MacroInfo *MI, 558 SourceRange Range); 559 560 /// Cached result of the last \see getPreprocessedEntitiesInRange 561 /// query. 562 struct { 563 SourceRange Range; 564 std::pair<int, int> Result; 565 } CachedRangeQuery; 566 567 std::pair<int, int> getPreprocessedEntitiesInRangeSlow(SourceRange R); 568 }; 569 570 } // namespace clang 571 572 inline void *operator new(size_t bytes, clang::PreprocessingRecord &PR, 573 unsigned alignment) noexcept { 574 return PR.Allocate(bytes, alignment); 575 } 576 577 inline void operator delete(void *ptr, clang::PreprocessingRecord &PR, 578 unsigned) noexcept { 579 PR.Deallocate(ptr); 580 } 581 582 #endif // LLVM_CLANG_LEX_PREPROCESSINGRECORD_H 583