IdentifierTable.cpp revision 5f7d2284c4b2f08d155732454002e68dc40c33ef
1//===--- IdentifierTable.cpp - Hash table for identifier lookup -----------===// 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 implements the IdentifierInfo, IdentifierVisitor, and 11// IdentifierTable interfaces. 12// 13//===----------------------------------------------------------------------===// 14 15#include "clang/Basic/IdentifierTable.h" 16#include "clang/Basic/LangOptions.h" 17#include "llvm/ADT/FoldingSet.h" 18#include "llvm/ADT/DenseMap.h" 19#include "llvm/Bitcode/Serialize.h" 20#include "llvm/Bitcode/Deserialize.h" 21#include <cstdio> 22 23using namespace clang; 24 25//===----------------------------------------------------------------------===// 26// IdentifierInfo Implementation 27//===----------------------------------------------------------------------===// 28 29IdentifierInfo::IdentifierInfo() { 30 TokenID = tok::identifier; 31 ObjCOrBuiltinID = 0; 32 HasMacro = false; 33 IsExtension = false; 34 IsPoisoned = false; 35 IsCPPOperatorKeyword = false; 36 NeedsHandleIdentifier = false; 37 FETokenInfo = 0; 38 Entry = 0; 39} 40 41//===----------------------------------------------------------------------===// 42// IdentifierTable Implementation 43//===----------------------------------------------------------------------===// 44 45IdentifierInfoLookup::~IdentifierInfoLookup() {} 46 47IdentifierTable::IdentifierTable(const LangOptions &LangOpts, 48 IdentifierInfoLookup* externalLookup) 49 : HashTable(8192), // Start with space for 8K identifiers. 50 ExternalLookup(externalLookup) { 51 52 // Populate the identifier table with info about keywords for the current 53 // language. 54 AddKeywords(LangOpts); 55} 56 57// This cstor is intended to be used only for serialization. 58IdentifierTable::IdentifierTable() 59 : HashTable(8192), ExternalLookup(0) { } 60 61//===----------------------------------------------------------------------===// 62// Language Keyword Implementation 63//===----------------------------------------------------------------------===// 64 65/// AddKeyword - This method is used to associate a token ID with specific 66/// identifiers because they are language keywords. This causes the lexer to 67/// automatically map matching identifiers to specialized token codes. 68/// 69/// The C90/C99/CPP/CPP0x flags are set to 0 if the token should be 70/// enabled in the specified langauge, set to 1 if it is an extension 71/// in the specified language, and set to 2 if disabled in the 72/// specified language. 73static void AddKeyword(const char *Keyword, unsigned KWLen, 74 tok::TokenKind TokenCode, 75 int C90, int C99, int CXX, int CXX0x, int BoolSupport, 76 const LangOptions &LangOpts, IdentifierTable &Table) { 77 int Flags = 0; 78 if (BoolSupport != 0) { 79 Flags = LangOpts.CPlusPlus? 0 : LangOpts.Boolean ? BoolSupport : 2; 80 } else if (LangOpts.CPlusPlus) { 81 Flags = LangOpts.CPlusPlus0x ? CXX0x : CXX; 82 } else if (LangOpts.C99) { 83 Flags = C99; 84 } else { 85 Flags = C90; 86 } 87 88 // Don't add this keyword if disabled in this language or if an extension 89 // and extensions are disabled. 90 if (Flags + LangOpts.NoExtensions >= 2) return; 91 92 IdentifierInfo &Info = Table.get(Keyword, Keyword+KWLen); 93 Info.setTokenID(TokenCode); 94 Info.setIsExtensionToken(Flags == 1); 95} 96 97static void AddAlias(const char *Keyword, unsigned KWLen, 98 tok::TokenKind AliaseeID, 99 const char *AliaseeKeyword, unsigned AliaseeKWLen, 100 const LangOptions &LangOpts, IdentifierTable &Table) { 101 IdentifierInfo &AliasInfo = Table.get(Keyword, Keyword+KWLen); 102 IdentifierInfo &AliaseeInfo = Table.get(AliaseeKeyword, 103 AliaseeKeyword+AliaseeKWLen); 104 AliasInfo.setTokenID(AliaseeID); 105 AliasInfo.setIsExtensionToken(AliaseeInfo.isExtensionToken()); 106} 107 108/// AddCXXOperatorKeyword - Register a C++ operator keyword alternative 109/// representations. 110static void AddCXXOperatorKeyword(const char *Keyword, unsigned KWLen, 111 tok::TokenKind TokenCode, 112 IdentifierTable &Table) { 113 IdentifierInfo &Info = Table.get(Keyword, Keyword + KWLen); 114 Info.setTokenID(TokenCode); 115 Info.setIsCPlusPlusOperatorKeyword(); 116} 117 118/// AddObjCKeyword - Register an Objective-C @keyword like "class" "selector" or 119/// "property". 120static void AddObjCKeyword(tok::ObjCKeywordKind ObjCID, 121 const char *Name, unsigned NameLen, 122 IdentifierTable &Table) { 123 Table.get(Name, Name+NameLen).setObjCKeywordID(ObjCID); 124} 125 126/// AddKeywords - Add all keywords to the symbol table. 127/// 128void IdentifierTable::AddKeywords(const LangOptions &LangOpts) { 129 enum { 130 C90Shift = 0, 131 EXTC90 = 1 << C90Shift, 132 NOTC90 = 2 << C90Shift, 133 C99Shift = 2, 134 EXTC99 = 1 << C99Shift, 135 NOTC99 = 2 << C99Shift, 136 CPPShift = 4, 137 EXTCPP = 1 << CPPShift, 138 NOTCPP = 2 << CPPShift, 139 CPP0xShift = 6, 140 EXTCPP0x = 1 << CPP0xShift, 141 NOTCPP0x = 2 << CPP0xShift, 142 BoolShift = 8, 143 BOOLSUPPORT = 1 << BoolShift, 144 Mask = 3 145 }; 146 147 // Add keywords and tokens for the current language. 148#define KEYWORD(NAME, FLAGS) \ 149 AddKeyword(#NAME, strlen(#NAME), tok::kw_ ## NAME, \ 150 ((FLAGS) >> C90Shift) & Mask, \ 151 ((FLAGS) >> C99Shift) & Mask, \ 152 ((FLAGS) >> CPPShift) & Mask, \ 153 ((FLAGS) >> CPP0xShift) & Mask, \ 154 ((FLAGS) >> BoolShift) & Mask, LangOpts, *this); 155#define ALIAS(NAME, TOK) \ 156 AddAlias(NAME, strlen(NAME), tok::kw_ ## TOK, #TOK, strlen(#TOK), \ 157 LangOpts, *this); 158#define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \ 159 if (LangOpts.CXXOperatorNames) \ 160 AddCXXOperatorKeyword(#NAME, strlen(#NAME), tok::ALIAS, *this); 161#define OBJC1_AT_KEYWORD(NAME) \ 162 if (LangOpts.ObjC1) \ 163 AddObjCKeyword(tok::objc_##NAME, #NAME, strlen(#NAME), *this); 164#define OBJC2_AT_KEYWORD(NAME) \ 165 if (LangOpts.ObjC2) \ 166 AddObjCKeyword(tok::objc_##NAME, #NAME, strlen(#NAME), *this); 167#include "clang/Basic/TokenKinds.def" 168} 169 170tok::PPKeywordKind IdentifierInfo::getPPKeywordID() const { 171 // We use a perfect hash function here involving the length of the keyword, 172 // the first and third character. For preprocessor ID's there are no 173 // collisions (if there were, the switch below would complain about duplicate 174 // case values). Note that this depends on 'if' being null terminated. 175 176#define HASH(LEN, FIRST, THIRD) \ 177 (LEN << 5) + (((FIRST-'a') + (THIRD-'a')) & 31) 178#define CASE(LEN, FIRST, THIRD, NAME) \ 179 case HASH(LEN, FIRST, THIRD): \ 180 return memcmp(Name, #NAME, LEN) ? tok::pp_not_keyword : tok::pp_ ## NAME 181 182 unsigned Len = getLength(); 183 if (Len < 2) return tok::pp_not_keyword; 184 const char *Name = getName(); 185 switch (HASH(Len, Name[0], Name[2])) { 186 default: return tok::pp_not_keyword; 187 CASE( 2, 'i', '\0', if); 188 CASE( 4, 'e', 'i', elif); 189 CASE( 4, 'e', 's', else); 190 CASE( 4, 'l', 'n', line); 191 CASE( 4, 's', 'c', sccs); 192 CASE( 5, 'e', 'd', endif); 193 CASE( 5, 'e', 'r', error); 194 CASE( 5, 'i', 'e', ident); 195 CASE( 5, 'i', 'd', ifdef); 196 CASE( 5, 'u', 'd', undef); 197 198 CASE( 6, 'a', 's', assert); 199 CASE( 6, 'd', 'f', define); 200 CASE( 6, 'i', 'n', ifndef); 201 CASE( 6, 'i', 'p', import); 202 CASE( 6, 'p', 'a', pragma); 203 204 CASE( 7, 'd', 'f', defined); 205 CASE( 7, 'i', 'c', include); 206 CASE( 7, 'w', 'r', warning); 207 208 CASE( 8, 'u', 'a', unassert); 209 CASE(12, 'i', 'c', include_next); 210#undef CASE 211#undef HASH 212 } 213} 214 215//===----------------------------------------------------------------------===// 216// Stats Implementation 217//===----------------------------------------------------------------------===// 218 219/// PrintStats - Print statistics about how well the identifier table is doing 220/// at hashing identifiers. 221void IdentifierTable::PrintStats() const { 222 unsigned NumBuckets = HashTable.getNumBuckets(); 223 unsigned NumIdentifiers = HashTable.getNumItems(); 224 unsigned NumEmptyBuckets = NumBuckets-NumIdentifiers; 225 unsigned AverageIdentifierSize = 0; 226 unsigned MaxIdentifierLength = 0; 227 228 // TODO: Figure out maximum times an identifier had to probe for -stats. 229 for (llvm::StringMap<IdentifierInfo*, llvm::BumpPtrAllocator>::const_iterator 230 I = HashTable.begin(), E = HashTable.end(); I != E; ++I) { 231 unsigned IdLen = I->getKeyLength(); 232 AverageIdentifierSize += IdLen; 233 if (MaxIdentifierLength < IdLen) 234 MaxIdentifierLength = IdLen; 235 } 236 237 fprintf(stderr, "\n*** Identifier Table Stats:\n"); 238 fprintf(stderr, "# Identifiers: %d\n", NumIdentifiers); 239 fprintf(stderr, "# Empty Buckets: %d\n", NumEmptyBuckets); 240 fprintf(stderr, "Hash density (#identifiers per bucket): %f\n", 241 NumIdentifiers/(double)NumBuckets); 242 fprintf(stderr, "Ave identifier length: %f\n", 243 (AverageIdentifierSize/(double)NumIdentifiers)); 244 fprintf(stderr, "Max identifier length: %d\n", MaxIdentifierLength); 245 246 // Compute statistics about the memory allocated for identifiers. 247 HashTable.getAllocator().PrintStats(); 248} 249 250//===----------------------------------------------------------------------===// 251// SelectorTable Implementation 252//===----------------------------------------------------------------------===// 253 254unsigned llvm::DenseMapInfo<clang::Selector>::getHashValue(clang::Selector S) { 255 return DenseMapInfo<void*>::getHashValue(S.getAsOpaquePtr()); 256} 257 258namespace clang { 259/// MultiKeywordSelector - One of these variable length records is kept for each 260/// selector containing more than one keyword. We use a folding set 261/// to unique aggregate names (keyword selectors in ObjC parlance). Access to 262/// this class is provided strictly through Selector. 263class MultiKeywordSelector 264 : public DeclarationNameExtra, public llvm::FoldingSetNode { 265 friend SelectorTable* SelectorTable::CreateAndRegister(llvm::Deserializer&); 266 MultiKeywordSelector(unsigned nKeys) { 267 ExtraKindOrNumArgs = NUM_EXTRA_KINDS + nKeys; 268 } 269public: 270 // Constructor for keyword selectors. 271 MultiKeywordSelector(unsigned nKeys, IdentifierInfo **IIV) { 272 assert((nKeys > 1) && "not a multi-keyword selector"); 273 ExtraKindOrNumArgs = NUM_EXTRA_KINDS + nKeys; 274 275 // Fill in the trailing keyword array. 276 IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(this+1); 277 for (unsigned i = 0; i != nKeys; ++i) 278 KeyInfo[i] = IIV[i]; 279 } 280 281 // getName - Derive the full selector name and return it. 282 std::string getName() const; 283 284 unsigned getNumArgs() const { return ExtraKindOrNumArgs - NUM_EXTRA_KINDS; } 285 286 typedef IdentifierInfo *const *keyword_iterator; 287 keyword_iterator keyword_begin() const { 288 return reinterpret_cast<keyword_iterator>(this+1); 289 } 290 keyword_iterator keyword_end() const { 291 return keyword_begin()+getNumArgs(); 292 } 293 IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const { 294 assert(i < getNumArgs() && "getIdentifierInfoForSlot(): illegal index"); 295 return keyword_begin()[i]; 296 } 297 static void Profile(llvm::FoldingSetNodeID &ID, 298 keyword_iterator ArgTys, unsigned NumArgs) { 299 ID.AddInteger(NumArgs); 300 for (unsigned i = 0; i != NumArgs; ++i) 301 ID.AddPointer(ArgTys[i]); 302 } 303 void Profile(llvm::FoldingSetNodeID &ID) { 304 Profile(ID, keyword_begin(), getNumArgs()); 305 } 306}; 307} // end namespace clang. 308 309unsigned Selector::getNumArgs() const { 310 unsigned IIF = getIdentifierInfoFlag(); 311 if (IIF == ZeroArg) 312 return 0; 313 if (IIF == OneArg) 314 return 1; 315 // We point to a MultiKeywordSelector (pointer doesn't contain any flags). 316 MultiKeywordSelector *SI = reinterpret_cast<MultiKeywordSelector *>(InfoPtr); 317 return SI->getNumArgs(); 318} 319 320IdentifierInfo *Selector::getIdentifierInfoForSlot(unsigned argIndex) const { 321 if (IdentifierInfo *II = getAsIdentifierInfo()) { 322 assert(argIndex == 0 && "illegal keyword index"); 323 return II; 324 } 325 // We point to a MultiKeywordSelector (pointer doesn't contain any flags). 326 MultiKeywordSelector *SI = reinterpret_cast<MultiKeywordSelector *>(InfoPtr); 327 return SI->getIdentifierInfoForSlot(argIndex); 328} 329 330std::string MultiKeywordSelector::getName() const { 331 std::string Result; 332 unsigned Length = 0; 333 for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) { 334 if (*I) 335 Length += (*I)->getLength(); 336 ++Length; // : 337 } 338 339 Result.reserve(Length); 340 341 for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) { 342 if (*I) 343 Result.insert(Result.end(), (*I)->getName(), 344 (*I)->getName()+(*I)->getLength()); 345 Result.push_back(':'); 346 } 347 348 return Result; 349} 350 351std::string Selector::getAsString() const { 352 if (IdentifierInfo *II = getAsIdentifierInfo()) { 353 if (getNumArgs() == 0) 354 return II->getName(); 355 356 std::string Res = II->getName(); 357 Res += ":"; 358 return Res; 359 } 360 361 // We have a multiple keyword selector (no embedded flags). 362 return reinterpret_cast<MultiKeywordSelector *>(InfoPtr)->getName(); 363} 364 365 366namespace { 367 struct SelectorTableImpl { 368 llvm::FoldingSet<MultiKeywordSelector> Table; 369 llvm::BumpPtrAllocator Allocator; 370 }; 371} // end anonymous namespace. 372 373static SelectorTableImpl &getSelectorTableImpl(void *P) { 374 return *static_cast<SelectorTableImpl*>(P); 375} 376 377 378Selector SelectorTable::getSelector(unsigned nKeys, IdentifierInfo **IIV) { 379 if (nKeys < 2) 380 return Selector(IIV[0], nKeys); 381 382 SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl); 383 384 // Unique selector, to guarantee there is one per name. 385 llvm::FoldingSetNodeID ID; 386 MultiKeywordSelector::Profile(ID, IIV, nKeys); 387 388 void *InsertPos = 0; 389 if (MultiKeywordSelector *SI = 390 SelTabImpl.Table.FindNodeOrInsertPos(ID, InsertPos)) 391 return Selector(SI); 392 393 // MultiKeywordSelector objects are not allocated with new because they have a 394 // variable size array (for parameter types) at the end of them. 395 unsigned Size = sizeof(MultiKeywordSelector) + nKeys*sizeof(IdentifierInfo *); 396 MultiKeywordSelector *SI = 397 (MultiKeywordSelector*)SelTabImpl.Allocator.Allocate(Size, 398 llvm::alignof<MultiKeywordSelector>()); 399 new (SI) MultiKeywordSelector(nKeys, IIV); 400 SelTabImpl.Table.InsertNode(SI, InsertPos); 401 return Selector(SI); 402} 403 404SelectorTable::SelectorTable() { 405 Impl = new SelectorTableImpl(); 406} 407 408SelectorTable::~SelectorTable() { 409 delete &getSelectorTableImpl(Impl); 410} 411 412//===----------------------------------------------------------------------===// 413// Serialization for IdentifierInfo and IdentifierTable. 414//===----------------------------------------------------------------------===// 415 416void IdentifierInfo::Emit(llvm::Serializer& S) const { 417 S.EmitInt(getTokenID()); 418 S.EmitInt(getBuiltinID()); 419 S.EmitInt(getObjCKeywordID()); 420 S.EmitBool(hasMacroDefinition()); 421 S.EmitBool(isExtensionToken()); 422 S.EmitBool(isPoisoned()); 423 S.EmitBool(isCPlusPlusOperatorKeyword()); 424 // FIXME: FETokenInfo 425} 426 427void IdentifierInfo::Read(llvm::Deserializer& D) { 428 setTokenID((tok::TokenKind) D.ReadInt()); 429 setBuiltinID(D.ReadInt()); 430 setObjCKeywordID((tok::ObjCKeywordKind) D.ReadInt()); 431 setHasMacroDefinition(D.ReadBool()); 432 setIsExtensionToken(D.ReadBool()); 433 setIsPoisoned(D.ReadBool()); 434 setIsCPlusPlusOperatorKeyword(D.ReadBool()); 435 // FIXME: FETokenInfo 436} 437 438void IdentifierTable::Emit(llvm::Serializer& S) const { 439 S.EnterBlock(); 440 441 S.EmitPtr(this); 442 443 for (iterator I=begin(), E=end(); I != E; ++I) { 444 const char* Key = I->getKeyData(); 445 const IdentifierInfo* Info = I->getValue(); 446 447 bool KeyRegistered = S.isRegistered(Key); 448 bool InfoRegistered = S.isRegistered(Info); 449 450 if (KeyRegistered || InfoRegistered) { 451 // These acrobatics are so that we don't incur the cost of registering 452 // a pointer with the backpatcher during deserialization if nobody 453 // references the object. 454 S.EmitPtr(InfoRegistered ? Info : NULL); 455 S.EmitPtr(KeyRegistered ? Key : NULL); 456 S.EmitCStr(Key); 457 S.Emit(*Info); 458 } 459 } 460 461 S.ExitBlock(); 462} 463 464IdentifierTable* IdentifierTable::CreateAndRegister(llvm::Deserializer& D) { 465 llvm::Deserializer::Location BLoc = D.getCurrentBlockLocation(); 466 467 std::vector<char> buff; 468 buff.reserve(200); 469 470 IdentifierTable* t = new IdentifierTable(); 471 D.RegisterPtr(t); 472 473 while (!D.FinishedBlock(BLoc)) { 474 llvm::SerializedPtrID InfoPtrID = D.ReadPtrID(); 475 llvm::SerializedPtrID KeyPtrID = D.ReadPtrID(); 476 477 D.ReadCStr(buff); 478 IdentifierInfo *II = &t->get(&buff[0], &buff[0] + buff.size()); 479 II->Read(D); 480 481 if (InfoPtrID) D.RegisterRef(InfoPtrID, II); 482 if (KeyPtrID) D.RegisterPtr(KeyPtrID, II->getName()); 483 } 484 485 return t; 486} 487 488//===----------------------------------------------------------------------===// 489// Serialization for Selector and SelectorTable. 490//===----------------------------------------------------------------------===// 491 492void Selector::Emit(llvm::Serializer& S) const { 493 S.EmitInt(getIdentifierInfoFlag()); 494 S.EmitPtr(reinterpret_cast<void*>(InfoPtr & ~ArgFlags)); 495} 496 497Selector Selector::ReadVal(llvm::Deserializer& D) { 498 unsigned flag = D.ReadInt(); 499 500 uintptr_t ptr; 501 D.ReadUIntPtr(ptr,false); // No backpatching. 502 503 return Selector(ptr | flag); 504} 505 506void SelectorTable::Emit(llvm::Serializer& S) const { 507 typedef llvm::FoldingSet<MultiKeywordSelector>::iterator iterator; 508 llvm::FoldingSet<MultiKeywordSelector> *SelTab; 509 SelTab = static_cast<llvm::FoldingSet<MultiKeywordSelector> *>(Impl); 510 511 S.EnterBlock(); 512 513 S.EmitPtr(this); 514 515 for (iterator I=SelTab->begin(), E=SelTab->end(); I != E; ++I) { 516 if (!S.isRegistered(&*I)) 517 continue; 518 519 S.FlushRecord(); // Start a new record. 520 521 S.EmitPtr(&*I); 522 S.EmitInt(I->getNumArgs()); 523 524 for (MultiKeywordSelector::keyword_iterator KI = I->keyword_begin(), 525 KE = I->keyword_end(); KI != KE; ++KI) 526 S.EmitPtr(*KI); 527 } 528 529 S.ExitBlock(); 530} 531 532SelectorTable* SelectorTable::CreateAndRegister(llvm::Deserializer& D) { 533 llvm::Deserializer::Location BLoc = D.getCurrentBlockLocation(); 534 535 SelectorTable* t = new SelectorTable(); 536 D.RegisterPtr(t); 537 538 llvm::FoldingSet<MultiKeywordSelector>& SelTab = 539 *static_cast<llvm::FoldingSet<MultiKeywordSelector>*>(t->Impl); 540 541 while (!D.FinishedBlock(BLoc)) { 542 543 llvm::SerializedPtrID PtrID = D.ReadPtrID(); 544 unsigned nKeys = D.ReadInt(); 545 546 MultiKeywordSelector *SI = 547 (MultiKeywordSelector*)malloc(sizeof(MultiKeywordSelector) + 548 nKeys*sizeof(IdentifierInfo *)); 549 550 new (SI) MultiKeywordSelector(nKeys); 551 552 D.RegisterPtr(PtrID,SI); 553 554 IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(SI+1); 555 556 for (unsigned i = 0; i != nKeys; ++i) 557 D.ReadPtr(KeyInfo[i],false); 558 559 SelTab.GetOrInsertNode(SI); 560 } 561 562 return t; 563} 564