1 //===--- IdentifierTable.cpp - Hash table for identifier lookup -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the IdentifierInfo, IdentifierVisitor, and
11 // IdentifierTable interfaces.
13 //===----------------------------------------------------------------------===//
15 #include "clang/Basic/CharInfo.h"
16 #include "clang/Basic/IdentifierTable.h"
17 #include "clang/Basic/LangOptions.h"
18 #include "clang/Basic/OperatorKinds.h"
19 #include "llvm/ADT/DenseMap.h"
20 #include "llvm/ADT/FoldingSet.h"
21 #include "llvm/ADT/SmallString.h"
22 #include "llvm/Support/ErrorHandling.h"
23 #include "llvm/Support/raw_ostream.h"
26 using namespace clang;
28 //===----------------------------------------------------------------------===//
29 // IdentifierInfo Implementation
30 //===----------------------------------------------------------------------===//
32 IdentifierInfo::IdentifierInfo() {
33 TokenID = tok::identifier;
38 IsCXX11CompatKeyword = false;
40 IsCPPOperatorKeyword = false;
41 NeedsHandleIdentifier = false;
43 ChangedAfterLoad = false;
44 RevertedTokenID = false;
46 IsModulesImport = false;
47 FETokenInfo = nullptr;
51 //===----------------------------------------------------------------------===//
52 // IdentifierTable Implementation
53 //===----------------------------------------------------------------------===//
55 IdentifierIterator::~IdentifierIterator() { }
57 IdentifierInfoLookup::~IdentifierInfoLookup() {}
60 /// \brief A simple identifier lookup iterator that represents an
61 /// empty sequence of identifiers.
62 class EmptyLookupIterator : public IdentifierIterator
65 StringRef Next() override { return StringRef(); }
69 IdentifierIterator *IdentifierInfoLookup::getIdentifiers() {
70 return new EmptyLookupIterator();
73 ExternalIdentifierLookup::~ExternalIdentifierLookup() {}
75 IdentifierTable::IdentifierTable(const LangOptions &LangOpts,
76 IdentifierInfoLookup* externalLookup)
77 : HashTable(8192), // Start with space for 8K identifiers.
78 ExternalLookup(externalLookup) {
80 // Populate the identifier table with info about keywords for the current
82 AddKeywords(LangOpts);
85 // Add the '_experimental_modules_import' contextual keyword.
86 get("import").setModulesImport(true);
89 //===----------------------------------------------------------------------===//
90 // Language Keyword Implementation
91 //===----------------------------------------------------------------------===//
93 // Constants for TokenKinds.def
109 WCHARSUPPORT = 0x02000,
110 HALFSUPPORT = 0x04000,
111 KEYALL = (0xffff & ~KEYNOMS) // Because KEYNOMS is used to exclude.
114 /// \brief How a keyword is treated in the selected standard.
116 KS_Disabled, // Disabled
117 KS_Extension, // Is an extension
118 KS_Enabled, // Enabled
119 KS_Future // Is a keyword in future standard
123 /// \brief Translates flags as specified in TokenKinds.def into keyword status
124 /// in the given language standard.
125 static KeywordStatus getKeywordStatus(const LangOptions &LangOpts,
127 if (Flags == KEYALL) return KS_Enabled;
128 if (LangOpts.CPlusPlus && (Flags & KEYCXX)) return KS_Enabled;
129 if (LangOpts.CPlusPlus11 && (Flags & KEYCXX11)) return KS_Enabled;
130 if (LangOpts.C99 && (Flags & KEYC99)) return KS_Enabled;
131 if (LangOpts.GNUKeywords && (Flags & KEYGNU)) return KS_Extension;
132 if (LangOpts.MicrosoftExt && (Flags & KEYMS)) return KS_Extension;
133 if (LangOpts.Borland && (Flags & KEYBORLAND)) return KS_Extension;
134 if (LangOpts.Bool && (Flags & BOOLSUPPORT)) return KS_Enabled;
135 if (LangOpts.Half && (Flags & HALFSUPPORT)) return KS_Enabled;
136 if (LangOpts.WChar && (Flags & WCHARSUPPORT)) return KS_Enabled;
137 if (LangOpts.AltiVec && (Flags & KEYALTIVEC)) return KS_Enabled;
138 if (LangOpts.OpenCL && (Flags & KEYOPENCL)) return KS_Enabled;
139 if (!LangOpts.CPlusPlus && (Flags & KEYNOCXX)) return KS_Enabled;
140 if (LangOpts.C11 && (Flags & KEYC11)) return KS_Enabled;
141 // We treat bridge casts as objective-C keywords so we can warn on them
143 if (LangOpts.ObjC2 && (Flags & KEYARC)) return KS_Enabled;
144 if (LangOpts.CPlusPlus && (Flags & KEYCXX11)) return KS_Future;
148 /// AddKeyword - This method is used to associate a token ID with specific
149 /// identifiers because they are language keywords. This causes the lexer to
150 /// automatically map matching identifiers to specialized token codes.
151 static void AddKeyword(StringRef Keyword,
152 tok::TokenKind TokenCode, unsigned Flags,
153 const LangOptions &LangOpts, IdentifierTable &Table) {
154 KeywordStatus AddResult = getKeywordStatus(LangOpts, Flags);
156 // Don't add this keyword under MSVCCompat.
157 if (LangOpts.MSVCCompat && (Flags & KEYNOMS))
159 // Don't add this keyword if disabled in this language.
160 if (AddResult == KS_Disabled) return;
162 IdentifierInfo &Info =
163 Table.get(Keyword, AddResult == KS_Future ? tok::identifier : TokenCode);
164 Info.setIsExtensionToken(AddResult == KS_Extension);
165 Info.setIsCXX11CompatKeyword(AddResult == KS_Future);
168 /// AddCXXOperatorKeyword - Register a C++ operator keyword alternative
170 static void AddCXXOperatorKeyword(StringRef Keyword,
171 tok::TokenKind TokenCode,
172 IdentifierTable &Table) {
173 IdentifierInfo &Info = Table.get(Keyword, TokenCode);
174 Info.setIsCPlusPlusOperatorKeyword();
177 /// AddObjCKeyword - Register an Objective-C \@keyword like "class" "selector"
179 static void AddObjCKeyword(StringRef Name,
180 tok::ObjCKeywordKind ObjCID,
181 IdentifierTable &Table) {
182 Table.get(Name).setObjCKeywordID(ObjCID);
185 /// AddKeywords - Add all keywords to the symbol table.
187 void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {
188 // Add keywords and tokens for the current language.
189 #define KEYWORD(NAME, FLAGS) \
190 AddKeyword(StringRef(#NAME), tok::kw_ ## NAME, \
191 FLAGS, LangOpts, *this);
192 #define ALIAS(NAME, TOK, FLAGS) \
193 AddKeyword(StringRef(NAME), tok::kw_ ## TOK, \
194 FLAGS, LangOpts, *this);
195 #define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \
196 if (LangOpts.CXXOperatorNames) \
197 AddCXXOperatorKeyword(StringRef(#NAME), tok::ALIAS, *this);
198 #define OBJC1_AT_KEYWORD(NAME) \
199 if (LangOpts.ObjC1) \
200 AddObjCKeyword(StringRef(#NAME), tok::objc_##NAME, *this);
201 #define OBJC2_AT_KEYWORD(NAME) \
202 if (LangOpts.ObjC2) \
203 AddObjCKeyword(StringRef(#NAME), tok::objc_##NAME, *this);
204 #define TESTING_KEYWORD(NAME, FLAGS)
205 #include "clang/Basic/TokenKinds.def"
207 if (LangOpts.ParseUnknownAnytype)
208 AddKeyword("__unknown_anytype", tok::kw___unknown_anytype, KEYALL,
212 /// \brief Checks if the specified token kind represents a keyword in the
213 /// specified language.
214 /// \returns Status of the keyword in the language.
215 static KeywordStatus getTokenKwStatus(const LangOptions &LangOpts,
218 #define KEYWORD(NAME, FLAGS) \
219 case tok::kw_##NAME: return getKeywordStatus(LangOpts, FLAGS);
220 #include "clang/Basic/TokenKinds.def"
221 default: return KS_Disabled;
225 /// \brief Returns true if the identifier represents a keyword in the
226 /// specified language.
227 bool IdentifierInfo::isKeyword(const LangOptions &LangOpts) {
228 switch (getTokenKwStatus(LangOpts, getTokenID())) {
237 tok::PPKeywordKind IdentifierInfo::getPPKeywordID() const {
238 // We use a perfect hash function here involving the length of the keyword,
239 // the first and third character. For preprocessor ID's there are no
240 // collisions (if there were, the switch below would complain about duplicate
241 // case values). Note that this depends on 'if' being null terminated.
243 #define HASH(LEN, FIRST, THIRD) \
244 (LEN << 5) + (((FIRST-'a') + (THIRD-'a')) & 31)
245 #define CASE(LEN, FIRST, THIRD, NAME) \
246 case HASH(LEN, FIRST, THIRD): \
247 return memcmp(Name, #NAME, LEN) ? tok::pp_not_keyword : tok::pp_ ## NAME
249 unsigned Len = getLength();
250 if (Len < 2) return tok::pp_not_keyword;
251 const char *Name = getNameStart();
252 switch (HASH(Len, Name[0], Name[2])) {
253 default: return tok::pp_not_keyword;
254 CASE( 2, 'i', '\0', if);
255 CASE( 4, 'e', 'i', elif);
256 CASE( 4, 'e', 's', else);
257 CASE( 4, 'l', 'n', line);
258 CASE( 4, 's', 'c', sccs);
259 CASE( 5, 'e', 'd', endif);
260 CASE( 5, 'e', 'r', error);
261 CASE( 5, 'i', 'e', ident);
262 CASE( 5, 'i', 'd', ifdef);
263 CASE( 5, 'u', 'd', undef);
265 CASE( 6, 'a', 's', assert);
266 CASE( 6, 'd', 'f', define);
267 CASE( 6, 'i', 'n', ifndef);
268 CASE( 6, 'i', 'p', import);
269 CASE( 6, 'p', 'a', pragma);
271 CASE( 7, 'd', 'f', defined);
272 CASE( 7, 'i', 'c', include);
273 CASE( 7, 'w', 'r', warning);
275 CASE( 8, 'u', 'a', unassert);
276 CASE(12, 'i', 'c', include_next);
278 CASE(14, '_', 'p', __public_macro);
280 CASE(15, '_', 'p', __private_macro);
282 CASE(16, '_', 'i', __include_macros);
288 //===----------------------------------------------------------------------===//
289 // Stats Implementation
290 //===----------------------------------------------------------------------===//
292 /// PrintStats - Print statistics about how well the identifier table is doing
293 /// at hashing identifiers.
294 void IdentifierTable::PrintStats() const {
295 unsigned NumBuckets = HashTable.getNumBuckets();
296 unsigned NumIdentifiers = HashTable.getNumItems();
297 unsigned NumEmptyBuckets = NumBuckets-NumIdentifiers;
298 unsigned AverageIdentifierSize = 0;
299 unsigned MaxIdentifierLength = 0;
301 // TODO: Figure out maximum times an identifier had to probe for -stats.
302 for (llvm::StringMap<IdentifierInfo*, llvm::BumpPtrAllocator>::const_iterator
303 I = HashTable.begin(), E = HashTable.end(); I != E; ++I) {
304 unsigned IdLen = I->getKeyLength();
305 AverageIdentifierSize += IdLen;
306 if (MaxIdentifierLength < IdLen)
307 MaxIdentifierLength = IdLen;
310 fprintf(stderr, "\n*** Identifier Table Stats:\n");
311 fprintf(stderr, "# Identifiers: %d\n", NumIdentifiers);
312 fprintf(stderr, "# Empty Buckets: %d\n", NumEmptyBuckets);
313 fprintf(stderr, "Hash density (#identifiers per bucket): %f\n",
314 NumIdentifiers/(double)NumBuckets);
315 fprintf(stderr, "Ave identifier length: %f\n",
316 (AverageIdentifierSize/(double)NumIdentifiers));
317 fprintf(stderr, "Max identifier length: %d\n", MaxIdentifierLength);
319 // Compute statistics about the memory allocated for identifiers.
320 HashTable.getAllocator().PrintStats();
323 //===----------------------------------------------------------------------===//
324 // SelectorTable Implementation
325 //===----------------------------------------------------------------------===//
327 unsigned llvm::DenseMapInfo<clang::Selector>::getHashValue(clang::Selector S) {
328 return DenseMapInfo<void*>::getHashValue(S.getAsOpaquePtr());
332 /// MultiKeywordSelector - One of these variable length records is kept for each
333 /// selector containing more than one keyword. We use a folding set
334 /// to unique aggregate names (keyword selectors in ObjC parlance). Access to
335 /// this class is provided strictly through Selector.
336 class MultiKeywordSelector
337 : public DeclarationNameExtra, public llvm::FoldingSetNode {
338 MultiKeywordSelector(unsigned nKeys) {
339 ExtraKindOrNumArgs = NUM_EXTRA_KINDS + nKeys;
342 // Constructor for keyword selectors.
343 MultiKeywordSelector(unsigned nKeys, IdentifierInfo **IIV) {
344 assert((nKeys > 1) && "not a multi-keyword selector");
345 ExtraKindOrNumArgs = NUM_EXTRA_KINDS + nKeys;
347 // Fill in the trailing keyword array.
348 IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(this+1);
349 for (unsigned i = 0; i != nKeys; ++i)
353 // getName - Derive the full selector name and return it.
354 std::string getName() const;
356 unsigned getNumArgs() const { return ExtraKindOrNumArgs - NUM_EXTRA_KINDS; }
358 typedef IdentifierInfo *const *keyword_iterator;
359 keyword_iterator keyword_begin() const {
360 return reinterpret_cast<keyword_iterator>(this+1);
362 keyword_iterator keyword_end() const {
363 return keyword_begin()+getNumArgs();
365 IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const {
366 assert(i < getNumArgs() && "getIdentifierInfoForSlot(): illegal index");
367 return keyword_begin()[i];
369 static void Profile(llvm::FoldingSetNodeID &ID,
370 keyword_iterator ArgTys, unsigned NumArgs) {
371 ID.AddInteger(NumArgs);
372 for (unsigned i = 0; i != NumArgs; ++i)
373 ID.AddPointer(ArgTys[i]);
375 void Profile(llvm::FoldingSetNodeID &ID) {
376 Profile(ID, keyword_begin(), getNumArgs());
379 } // end namespace clang.
381 unsigned Selector::getNumArgs() const {
382 unsigned IIF = getIdentifierInfoFlag();
387 // We point to a MultiKeywordSelector.
388 MultiKeywordSelector *SI = getMultiKeywordSelector();
389 return SI->getNumArgs();
392 IdentifierInfo *Selector::getIdentifierInfoForSlot(unsigned argIndex) const {
393 if (getIdentifierInfoFlag() < MultiArg) {
394 assert(argIndex == 0 && "illegal keyword index");
395 return getAsIdentifierInfo();
397 // We point to a MultiKeywordSelector.
398 MultiKeywordSelector *SI = getMultiKeywordSelector();
399 return SI->getIdentifierInfoForSlot(argIndex);
402 StringRef Selector::getNameForSlot(unsigned int argIndex) const {
403 IdentifierInfo *II = getIdentifierInfoForSlot(argIndex);
404 return II? II->getName() : StringRef();
407 std::string MultiKeywordSelector::getName() const {
408 SmallString<256> Str;
409 llvm::raw_svector_ostream OS(Str);
410 for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) {
412 OS << (*I)->getName();
419 std::string Selector::getAsString() const {
421 return "<null selector>";
423 if (getIdentifierInfoFlag() < MultiArg) {
424 IdentifierInfo *II = getAsIdentifierInfo();
426 // If the number of arguments is 0 then II is guaranteed to not be null.
427 if (getNumArgs() == 0)
428 return II->getName();
433 return II->getName().str() + ":";
436 // We have a multiple keyword selector.
437 return getMultiKeywordSelector()->getName();
440 void Selector::print(llvm::raw_ostream &OS) const {
444 /// Interpreting the given string using the normal CamelCase
445 /// conventions, determine whether the given string starts with the
446 /// given "word", which is assumed to end in a lowercase letter.
447 static bool startsWithWord(StringRef name, StringRef word) {
448 if (name.size() < word.size()) return false;
449 return ((name.size() == word.size() || !isLowercase(name[word.size()])) &&
450 name.startswith(word));
453 ObjCMethodFamily Selector::getMethodFamilyImpl(Selector sel) {
454 IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
455 if (!first) return OMF_None;
457 StringRef name = first->getName();
458 if (sel.isUnarySelector()) {
459 if (name == "autorelease") return OMF_autorelease;
460 if (name == "dealloc") return OMF_dealloc;
461 if (name == "finalize") return OMF_finalize;
462 if (name == "release") return OMF_release;
463 if (name == "retain") return OMF_retain;
464 if (name == "retainCount") return OMF_retainCount;
465 if (name == "self") return OMF_self;
466 if (name == "initialize") return OMF_initialize;
469 if (name == "performSelector") return OMF_performSelector;
471 // The other method families may begin with a prefix of underscores.
472 while (!name.empty() && name.front() == '_')
473 name = name.substr(1);
475 if (name.empty()) return OMF_None;
476 switch (name.front()) {
478 if (startsWithWord(name, "alloc")) return OMF_alloc;
481 if (startsWithWord(name, "copy")) return OMF_copy;
484 if (startsWithWord(name, "init")) return OMF_init;
487 if (startsWithWord(name, "mutableCopy")) return OMF_mutableCopy;
490 if (startsWithWord(name, "new")) return OMF_new;
499 ObjCInstanceTypeFamily Selector::getInstTypeMethodFamily(Selector sel) {
500 IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
501 if (!first) return OIT_None;
503 StringRef name = first->getName();
505 if (name.empty()) return OIT_None;
506 switch (name.front()) {
508 if (startsWithWord(name, "array")) return OIT_Array;
511 if (startsWithWord(name, "default")) return OIT_ReturnsSelf;
512 if (startsWithWord(name, "dictionary")) return OIT_Dictionary;
515 if (startsWithWord(name, "shared")) return OIT_ReturnsSelf;
516 if (startsWithWord(name, "standard")) return OIT_Singleton;
518 if (startsWithWord(name, "init")) return OIT_Init;
525 ObjCStringFormatFamily Selector::getStringFormatFamilyImpl(Selector sel) {
526 IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
527 if (!first) return SFF_None;
529 StringRef name = first->getName();
531 switch (name.front()) {
533 if (name == "appendFormat") return SFF_NSString;
537 if (name == "initWithFormat") return SFF_NSString;
541 if (name == "localizedStringWithFormat") return SFF_NSString;
545 if (name == "stringByAppendingFormat" ||
546 name == "stringWithFormat") return SFF_NSString;
553 struct SelectorTableImpl {
554 llvm::FoldingSet<MultiKeywordSelector> Table;
555 llvm::BumpPtrAllocator Allocator;
557 } // end anonymous namespace.
559 static SelectorTableImpl &getSelectorTableImpl(void *P) {
560 return *static_cast<SelectorTableImpl*>(P);
564 SelectorTable::constructSetterName(StringRef Name) {
565 SmallString<64> SetterName("set");
567 SetterName[3] = toUppercase(SetterName[3]);
572 SelectorTable::constructSetterSelector(IdentifierTable &Idents,
573 SelectorTable &SelTable,
574 const IdentifierInfo *Name) {
575 IdentifierInfo *SetterName =
576 &Idents.get(constructSetterName(Name->getName()));
577 return SelTable.getUnarySelector(SetterName);
580 size_t SelectorTable::getTotalMemory() const {
581 SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl);
582 return SelTabImpl.Allocator.getTotalMemory();
585 Selector SelectorTable::getSelector(unsigned nKeys, IdentifierInfo **IIV) {
587 return Selector(IIV[0], nKeys);
589 SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl);
591 // Unique selector, to guarantee there is one per name.
592 llvm::FoldingSetNodeID ID;
593 MultiKeywordSelector::Profile(ID, IIV, nKeys);
595 void *InsertPos = nullptr;
596 if (MultiKeywordSelector *SI =
597 SelTabImpl.Table.FindNodeOrInsertPos(ID, InsertPos))
600 // MultiKeywordSelector objects are not allocated with new because they have a
601 // variable size array (for parameter types) at the end of them.
602 unsigned Size = sizeof(MultiKeywordSelector) + nKeys*sizeof(IdentifierInfo *);
603 MultiKeywordSelector *SI =
604 (MultiKeywordSelector*)SelTabImpl.Allocator.Allocate(Size,
605 llvm::alignOf<MultiKeywordSelector>());
606 new (SI) MultiKeywordSelector(nKeys, IIV);
607 SelTabImpl.Table.InsertNode(SI, InsertPos);
611 SelectorTable::SelectorTable() {
612 Impl = new SelectorTableImpl();
615 SelectorTable::~SelectorTable() {
616 delete &getSelectorTableImpl(Impl);
619 const char *clang::getOperatorSpelling(OverloadedOperatorKind Operator) {
622 case NUM_OVERLOADED_OPERATORS:
625 #define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
626 case OO_##Name: return Spelling;
627 #include "clang/Basic/OperatorKinds.def"
630 llvm_unreachable("Invalid OverloadedOperatorKind!");