IdentifierTable.cpp revision 077bf5e2f48acfa9e7d69429b6e4ba86ea14896d
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 22using namespace clang; 23 24//===----------------------------------------------------------------------===// 25// IdentifierInfo Implementation 26//===----------------------------------------------------------------------===// 27 28IdentifierInfo::IdentifierInfo() { 29 TokenID = tok::identifier; 30 ObjCOrBuiltinID = 0; 31 HasMacro = false; 32 IsExtension = false; 33 IsPoisoned = false; 34 IsCPPOperatorKeyword = false; 35 FETokenInfo = 0; 36} 37 38//===----------------------------------------------------------------------===// 39// IdentifierTable Implementation 40//===----------------------------------------------------------------------===// 41 42IdentifierTable::IdentifierTable(const LangOptions &LangOpts) 43 // Start with space for 8K identifiers. 44 : HashTable(8192) { 45 46 // Populate the identifier table with info about keywords for the current 47 // language. 48 AddKeywords(LangOpts); 49} 50 51// This cstor is intended to be used only for serialization. 52IdentifierTable::IdentifierTable() 53 : HashTable(8192) { } 54 55//===----------------------------------------------------------------------===// 56// Language Keyword Implementation 57//===----------------------------------------------------------------------===// 58 59/// AddKeyword - This method is used to associate a token ID with specific 60/// identifiers because they are language keywords. This causes the lexer to 61/// automatically map matching identifiers to specialized token codes. 62/// 63/// The C90/C99/CPP/CPP0x flags are set to 0 if the token should be 64/// enabled in the specified langauge, set to 1 if it is an extension 65/// in the specified language, and set to 2 if disabled in the 66/// specified language. 67static void AddKeyword(const char *Keyword, unsigned KWLen, 68 tok::TokenKind TokenCode, 69 int C90, int C99, int CXX, int CXX0x, int BoolSupport, 70 const LangOptions &LangOpts, IdentifierTable &Table) { 71 int Flags = 0; 72 if (BoolSupport != 0) { 73 Flags = LangOpts.CPlusPlus? 0 : LangOpts.Boolean ? BoolSupport : 2; 74 } else if (LangOpts.CPlusPlus) { 75 Flags = LangOpts.CPlusPlus0x ? CXX0x : CXX; 76 } else if (LangOpts.C99) { 77 Flags = C99; 78 } else { 79 Flags = C90; 80 } 81 82 // Don't add this keyword if disabled in this language or if an extension 83 // and extensions are disabled. 84 if (Flags + LangOpts.NoExtensions >= 2) return; 85 86 IdentifierInfo &Info = Table.get(Keyword, Keyword+KWLen); 87 Info.setTokenID(TokenCode); 88 Info.setIsExtensionToken(Flags == 1); 89} 90 91static void AddAlias(const char *Keyword, unsigned KWLen, 92 tok::TokenKind AliaseeID, 93 const char *AliaseeKeyword, unsigned AliaseeKWLen, 94 const LangOptions &LangOpts, IdentifierTable &Table) { 95 IdentifierInfo &AliasInfo = Table.get(Keyword, Keyword+KWLen); 96 IdentifierInfo &AliaseeInfo = Table.get(AliaseeKeyword, 97 AliaseeKeyword+AliaseeKWLen); 98 AliasInfo.setTokenID(AliaseeID); 99 AliasInfo.setIsExtensionToken(AliaseeInfo.isExtensionToken()); 100} 101 102/// AddCXXOperatorKeyword - Register a C++ operator keyword alternative 103/// representations. 104static void AddCXXOperatorKeyword(const char *Keyword, unsigned KWLen, 105 tok::TokenKind TokenCode, 106 IdentifierTable &Table) { 107 IdentifierInfo &Info = Table.get(Keyword, Keyword + KWLen); 108 Info.setTokenID(TokenCode); 109 Info.setIsCPlusPlusOperatorKeyword(); 110} 111 112/// AddObjCKeyword - Register an Objective-C @keyword like "class" "selector" or 113/// "property". 114static void AddObjCKeyword(tok::ObjCKeywordKind ObjCID, 115 const char *Name, unsigned NameLen, 116 IdentifierTable &Table) { 117 Table.get(Name, Name+NameLen).setObjCKeywordID(ObjCID); 118} 119 120/// AddKeywords - Add all keywords to the symbol table. 121/// 122void IdentifierTable::AddKeywords(const LangOptions &LangOpts) { 123 enum { 124 C90Shift = 0, 125 EXTC90 = 1 << C90Shift, 126 NOTC90 = 2 << C90Shift, 127 C99Shift = 2, 128 EXTC99 = 1 << C99Shift, 129 NOTC99 = 2 << C99Shift, 130 CPPShift = 4, 131 EXTCPP = 1 << CPPShift, 132 NOTCPP = 2 << CPPShift, 133 CPP0xShift = 6, 134 EXTCPP0x = 1 << CPP0xShift, 135 NOTCPP0x = 2 << CPP0xShift, 136 BoolShift = 8, 137 BOOLSUPPORT = 1 << BoolShift, 138 Mask = 3 139 }; 140 141 // Add keywords and tokens for the current language. 142#define KEYWORD(NAME, FLAGS) \ 143 AddKeyword(#NAME, strlen(#NAME), tok::kw_ ## NAME, \ 144 ((FLAGS) >> C90Shift) & Mask, \ 145 ((FLAGS) >> C99Shift) & Mask, \ 146 ((FLAGS) >> CPPShift) & Mask, \ 147 ((FLAGS) >> CPP0xShift) & Mask, \ 148 ((FLAGS) >> BoolShift) & Mask, LangOpts, *this); 149#define ALIAS(NAME, TOK) \ 150 AddAlias(NAME, strlen(NAME), tok::kw_ ## TOK, #TOK, strlen(#TOK), \ 151 LangOpts, *this); 152#define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \ 153 if (LangOpts.CXXOperatorNames) \ 154 AddCXXOperatorKeyword(#NAME, strlen(#NAME), tok::ALIAS, *this); 155#define OBJC1_AT_KEYWORD(NAME) \ 156 if (LangOpts.ObjC1) \ 157 AddObjCKeyword(tok::objc_##NAME, #NAME, strlen(#NAME), *this); 158#define OBJC2_AT_KEYWORD(NAME) \ 159 if (LangOpts.ObjC2) \ 160 AddObjCKeyword(tok::objc_##NAME, #NAME, strlen(#NAME), *this); 161#include "clang/Basic/TokenKinds.def" 162} 163 164tok::PPKeywordKind IdentifierInfo::getPPKeywordID() const { 165 // We use a perfect hash function here involving the length of the keyword, 166 // the first and third character. For preprocessor ID's there are no 167 // collisions (if there were, the switch below would complain about duplicate 168 // case values). Note that this depends on 'if' being null terminated. 169 170#define HASH(LEN, FIRST, THIRD) \ 171 (LEN << 5) + (((FIRST-'a') + (THIRD-'a')) & 31) 172#define CASE(LEN, FIRST, THIRD, NAME) \ 173 case HASH(LEN, FIRST, THIRD): \ 174 return memcmp(Name, #NAME, LEN) ? tok::pp_not_keyword : tok::pp_ ## NAME 175 176 unsigned Len = getLength(); 177 if (Len < 2) return tok::pp_not_keyword; 178 const char *Name = getName(); 179 switch (HASH(Len, Name[0], Name[2])) { 180 default: return tok::pp_not_keyword; 181 CASE( 2, 'i', '\0', if); 182 CASE( 4, 'e', 'i', elif); 183 CASE( 4, 'e', 's', else); 184 CASE( 4, 'l', 'n', line); 185 CASE( 4, 's', 'c', sccs); 186 CASE( 5, 'e', 'd', endif); 187 CASE( 5, 'e', 'r', error); 188 CASE( 5, 'i', 'e', ident); 189 CASE( 5, 'i', 'd', ifdef); 190 CASE( 5, 'u', 'd', undef); 191 192 CASE( 6, 'a', 's', assert); 193 CASE( 6, 'd', 'f', define); 194 CASE( 6, 'i', 'n', ifndef); 195 CASE( 6, 'i', 'p', import); 196 CASE( 6, 'p', 'a', pragma); 197 198 CASE( 7, 'd', 'f', defined); 199 CASE( 7, 'i', 'c', include); 200 CASE( 7, 'w', 'r', warning); 201 202 CASE( 8, 'u', 'a', unassert); 203 CASE(12, 'i', 'c', include_next); 204#undef CASE 205#undef HASH 206 } 207} 208 209//===----------------------------------------------------------------------===// 210// Stats Implementation 211//===----------------------------------------------------------------------===// 212 213/// PrintStats - Print statistics about how well the identifier table is doing 214/// at hashing identifiers. 215void IdentifierTable::PrintStats() const { 216 unsigned NumBuckets = HashTable.getNumBuckets(); 217 unsigned NumIdentifiers = HashTable.getNumItems(); 218 unsigned NumEmptyBuckets = NumBuckets-NumIdentifiers; 219 unsigned AverageIdentifierSize = 0; 220 unsigned MaxIdentifierLength = 0; 221 222 // TODO: Figure out maximum times an identifier had to probe for -stats. 223 for (llvm::StringMap<IdentifierInfo, llvm::BumpPtrAllocator>::const_iterator 224 I = HashTable.begin(), E = HashTable.end(); I != E; ++I) { 225 unsigned IdLen = I->getKeyLength(); 226 AverageIdentifierSize += IdLen; 227 if (MaxIdentifierLength < IdLen) 228 MaxIdentifierLength = IdLen; 229 } 230 231 fprintf(stderr, "\n*** Identifier Table Stats:\n"); 232 fprintf(stderr, "# Identifiers: %d\n", NumIdentifiers); 233 fprintf(stderr, "# Empty Buckets: %d\n", NumEmptyBuckets); 234 fprintf(stderr, "Hash density (#identifiers per bucket): %f\n", 235 NumIdentifiers/(double)NumBuckets); 236 fprintf(stderr, "Ave identifier length: %f\n", 237 (AverageIdentifierSize/(double)NumIdentifiers)); 238 fprintf(stderr, "Max identifier length: %d\n", MaxIdentifierLength); 239 240 // Compute statistics about the memory allocated for identifiers. 241 HashTable.getAllocator().PrintStats(); 242} 243 244//===----------------------------------------------------------------------===// 245// SelectorTable Implementation 246//===----------------------------------------------------------------------===// 247 248unsigned llvm::DenseMapInfo<clang::Selector>::getHashValue(clang::Selector S) { 249 return DenseMapInfo<void*>::getHashValue(S.getAsOpaquePtr()); 250} 251 252namespace clang { 253/// MultiKeywordSelector - One of these variable length records is kept for each 254/// selector containing more than one keyword. We use a folding set 255/// to unique aggregate names (keyword selectors in ObjC parlance). Access to 256/// this class is provided strictly through Selector. 257class MultiKeywordSelector 258 : public DeclarationNameExtra, public llvm::FoldingSetNode { 259 friend SelectorTable* SelectorTable::CreateAndRegister(llvm::Deserializer&); 260 MultiKeywordSelector(unsigned nKeys) { 261 ExtraKindOrNumArgs = NUM_EXTRA_KINDS + nKeys; 262 } 263public: 264 // Constructor for keyword selectors. 265 MultiKeywordSelector(unsigned nKeys, IdentifierInfo **IIV) { 266 assert((nKeys > 1) && "not a multi-keyword selector"); 267 ExtraKindOrNumArgs = NUM_EXTRA_KINDS + nKeys; 268 269 // Fill in the trailing keyword array. 270 IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(this+1); 271 for (unsigned i = 0; i != nKeys; ++i) 272 KeyInfo[i] = IIV[i]; 273 } 274 275 // getName - Derive the full selector name and return it. 276 std::string getName() const; 277 278 unsigned getNumArgs() const { return ExtraKindOrNumArgs - NUM_EXTRA_KINDS; } 279 280 typedef IdentifierInfo *const *keyword_iterator; 281 keyword_iterator keyword_begin() const { 282 return reinterpret_cast<keyword_iterator>(this+1); 283 } 284 keyword_iterator keyword_end() const { 285 return keyword_begin()+getNumArgs(); 286 } 287 IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const { 288 assert(i < getNumArgs() && "getIdentifierInfoForSlot(): illegal index"); 289 return keyword_begin()[i]; 290 } 291 static void Profile(llvm::FoldingSetNodeID &ID, 292 keyword_iterator ArgTys, unsigned NumArgs) { 293 ID.AddInteger(NumArgs); 294 for (unsigned i = 0; i != NumArgs; ++i) 295 ID.AddPointer(ArgTys[i]); 296 } 297 void Profile(llvm::FoldingSetNodeID &ID) { 298 Profile(ID, keyword_begin(), getNumArgs()); 299 } 300}; 301} // end namespace clang. 302 303unsigned Selector::getNumArgs() const { 304 unsigned IIF = getIdentifierInfoFlag(); 305 if (IIF == ZeroArg) 306 return 0; 307 if (IIF == OneArg) 308 return 1; 309 // We point to a MultiKeywordSelector (pointer doesn't contain any flags). 310 MultiKeywordSelector *SI = reinterpret_cast<MultiKeywordSelector *>(InfoPtr); 311 return SI->getNumArgs(); 312} 313 314IdentifierInfo *Selector::getIdentifierInfoForSlot(unsigned argIndex) const { 315 if (IdentifierInfo *II = getAsIdentifierInfo()) { 316 assert(argIndex == 0 && "illegal keyword index"); 317 return II; 318 } 319 // We point to a MultiKeywordSelector (pointer doesn't contain any flags). 320 MultiKeywordSelector *SI = reinterpret_cast<MultiKeywordSelector *>(InfoPtr); 321 return SI->getIdentifierInfoForSlot(argIndex); 322} 323 324std::string MultiKeywordSelector::getName() const { 325 std::string Result; 326 unsigned Length = 0; 327 for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) { 328 if (*I) 329 Length += (*I)->getLength(); 330 ++Length; // : 331 } 332 333 Result.reserve(Length); 334 335 for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) { 336 if (*I) 337 Result.insert(Result.end(), (*I)->getName(), 338 (*I)->getName()+(*I)->getLength()); 339 Result.push_back(':'); 340 } 341 342 return Result; 343} 344 345std::string Selector::getAsString() const { 346 if (IdentifierInfo *II = getAsIdentifierInfo()) { 347 if (getNumArgs() == 0) 348 return II->getName(); 349 350 std::string Res = II->getName(); 351 Res += ":"; 352 return Res; 353 } 354 355 // We have a multiple keyword selector (no embedded flags). 356 return reinterpret_cast<MultiKeywordSelector *>(InfoPtr)->getName(); 357} 358 359 360Selector SelectorTable::getSelector(unsigned nKeys, IdentifierInfo **IIV) { 361 if (nKeys < 2) 362 return Selector(IIV[0], nKeys); 363 364 llvm::FoldingSet<MultiKeywordSelector> *SelTab; 365 366 SelTab = static_cast<llvm::FoldingSet<MultiKeywordSelector> *>(Impl); 367 368 // Unique selector, to guarantee there is one per name. 369 llvm::FoldingSetNodeID ID; 370 MultiKeywordSelector::Profile(ID, IIV, nKeys); 371 372 void *InsertPos = 0; 373 if (MultiKeywordSelector *SI = SelTab->FindNodeOrInsertPos(ID, InsertPos)) 374 return Selector(SI); 375 376 // MultiKeywordSelector objects are not allocated with new because they have a 377 // variable size array (for parameter types) at the end of them. 378 MultiKeywordSelector *SI = 379 (MultiKeywordSelector*)malloc(sizeof(MultiKeywordSelector) + 380 nKeys*sizeof(IdentifierInfo *)); 381 new (SI) MultiKeywordSelector(nKeys, IIV); 382 SelTab->InsertNode(SI, InsertPos); 383 return Selector(SI); 384} 385 386SelectorTable::SelectorTable() { 387 Impl = new llvm::FoldingSet<MultiKeywordSelector>; 388} 389 390SelectorTable::~SelectorTable() { 391 delete static_cast<llvm::FoldingSet<MultiKeywordSelector> *>(Impl); 392} 393 394//===----------------------------------------------------------------------===// 395// Serialization for IdentifierInfo and IdentifierTable. 396//===----------------------------------------------------------------------===// 397 398void IdentifierInfo::Emit(llvm::Serializer& S) const { 399 S.EmitInt(getTokenID()); 400 S.EmitInt(getBuiltinID()); 401 S.EmitInt(getObjCKeywordID()); 402 S.EmitBool(hasMacroDefinition()); 403 S.EmitBool(isExtensionToken()); 404 S.EmitBool(isPoisoned()); 405 S.EmitBool(isCPlusPlusOperatorKeyword()); 406 // FIXME: FETokenInfo 407} 408 409void IdentifierInfo::Read(llvm::Deserializer& D) { 410 setTokenID((tok::TokenKind) D.ReadInt()); 411 setBuiltinID(D.ReadInt()); 412 setObjCKeywordID((tok::ObjCKeywordKind) D.ReadInt()); 413 setHasMacroDefinition(D.ReadBool()); 414 setIsExtensionToken(D.ReadBool()); 415 setIsPoisoned(D.ReadBool()); 416 setIsCPlusPlusOperatorKeyword(D.ReadBool()); 417 // FIXME: FETokenInfo 418} 419 420void IdentifierTable::Emit(llvm::Serializer& S) const { 421 S.EnterBlock(); 422 423 S.EmitPtr(this); 424 425 for (iterator I=begin(), E=end(); I != E; ++I) { 426 const char* Key = I->getKeyData(); 427 const IdentifierInfo* Info = &I->getValue(); 428 429 bool KeyRegistered = S.isRegistered(Key); 430 bool InfoRegistered = S.isRegistered(Info); 431 432 if (KeyRegistered || InfoRegistered) { 433 // These acrobatics are so that we don't incur the cost of registering 434 // a pointer with the backpatcher during deserialization if nobody 435 // references the object. 436 S.EmitPtr(InfoRegistered ? Info : NULL); 437 S.EmitPtr(KeyRegistered ? Key : NULL); 438 S.EmitCStr(Key); 439 S.Emit(*Info); 440 } 441 } 442 443 S.ExitBlock(); 444} 445 446IdentifierTable* IdentifierTable::CreateAndRegister(llvm::Deserializer& D) { 447 llvm::Deserializer::Location BLoc = D.getCurrentBlockLocation(); 448 449 std::vector<char> buff; 450 buff.reserve(200); 451 452 IdentifierTable* t = new IdentifierTable(); 453 D.RegisterPtr(t); 454 455 while (!D.FinishedBlock(BLoc)) { 456 llvm::SerializedPtrID InfoPtrID = D.ReadPtrID(); 457 llvm::SerializedPtrID KeyPtrID = D.ReadPtrID(); 458 459 D.ReadCStr(buff); 460 461 llvm::StringMapEntry<IdentifierInfo>& Entry = 462 t->HashTable.GetOrCreateValue(&buff[0],&buff[0]+buff.size()); 463 464 D.Read(Entry.getValue()); 465 466 if (InfoPtrID) 467 D.RegisterRef(InfoPtrID,Entry.getValue()); 468 469 if (KeyPtrID) 470 D.RegisterPtr(KeyPtrID,Entry.getKeyData()); 471 } 472 473 return t; 474} 475 476//===----------------------------------------------------------------------===// 477// Serialization for Selector and SelectorTable. 478//===----------------------------------------------------------------------===// 479 480void Selector::Emit(llvm::Serializer& S) const { 481 S.EmitInt(getIdentifierInfoFlag()); 482 S.EmitPtr(reinterpret_cast<void*>(InfoPtr & ~ArgFlags)); 483} 484 485Selector Selector::ReadVal(llvm::Deserializer& D) { 486 unsigned flag = D.ReadInt(); 487 488 uintptr_t ptr; 489 D.ReadUIntPtr(ptr,false); // No backpatching. 490 491 return Selector(ptr | flag); 492} 493 494void SelectorTable::Emit(llvm::Serializer& S) const { 495 typedef llvm::FoldingSet<MultiKeywordSelector>::iterator iterator; 496 llvm::FoldingSet<MultiKeywordSelector> *SelTab; 497 SelTab = static_cast<llvm::FoldingSet<MultiKeywordSelector> *>(Impl); 498 499 S.EnterBlock(); 500 501 S.EmitPtr(this); 502 503 for (iterator I=SelTab->begin(), E=SelTab->end(); I != E; ++I) { 504 if (!S.isRegistered(&*I)) 505 continue; 506 507 S.FlushRecord(); // Start a new record. 508 509 S.EmitPtr(&*I); 510 S.EmitInt(I->getNumArgs()); 511 512 for (MultiKeywordSelector::keyword_iterator KI = I->keyword_begin(), 513 KE = I->keyword_end(); KI != KE; ++KI) 514 S.EmitPtr(*KI); 515 } 516 517 S.ExitBlock(); 518} 519 520SelectorTable* SelectorTable::CreateAndRegister(llvm::Deserializer& D) { 521 llvm::Deserializer::Location BLoc = D.getCurrentBlockLocation(); 522 523 SelectorTable* t = new SelectorTable(); 524 D.RegisterPtr(t); 525 526 llvm::FoldingSet<MultiKeywordSelector>& SelTab = 527 *static_cast<llvm::FoldingSet<MultiKeywordSelector>*>(t->Impl); 528 529 while (!D.FinishedBlock(BLoc)) { 530 531 llvm::SerializedPtrID PtrID = D.ReadPtrID(); 532 unsigned nKeys = D.ReadInt(); 533 534 MultiKeywordSelector *SI = 535 (MultiKeywordSelector*)malloc(sizeof(MultiKeywordSelector) + 536 nKeys*sizeof(IdentifierInfo *)); 537 538 new (SI) MultiKeywordSelector(nKeys); 539 540 D.RegisterPtr(PtrID,SI); 541 542 IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(SI+1); 543 544 for (unsigned i = 0; i != nKeys; ++i) 545 D.ReadPtr(KeyInfo[i],false); 546 547 SelTab.GetOrInsertNode(SI); 548 } 549 550 return t; 551} 552