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 "clang/Basic/Specifiers.h"
20 #include "llvm/ADT/DenseMap.h"
21 #include "llvm/ADT/FoldingSet.h"
22 #include "llvm/ADT/SmallString.h"
23 #include "llvm/Support/ErrorHandling.h"
24 #include "llvm/Support/raw_ostream.h"
27 using namespace clang;
29 //===----------------------------------------------------------------------===//
30 // IdentifierInfo Implementation
31 //===----------------------------------------------------------------------===//
33 IdentifierInfo::IdentifierInfo() {
34 TokenID = tok::identifier;
39 IsFutureCompatKeyword = false;
41 IsCPPOperatorKeyword = false;
42 NeedsHandleIdentifier = false;
44 ChangedAfterLoad = false;
45 FEChangedAfterLoad = false;
46 RevertedTokenID = false;
48 IsModulesImport = false;
49 FETokenInfo = nullptr;
53 //===----------------------------------------------------------------------===//
54 // IdentifierTable Implementation
55 //===----------------------------------------------------------------------===//
57 IdentifierIterator::~IdentifierIterator() { }
59 IdentifierInfoLookup::~IdentifierInfoLookup() {}
62 /// \brief A simple identifier lookup iterator that represents an
63 /// empty sequence of identifiers.
64 class EmptyLookupIterator : public IdentifierIterator
67 StringRef Next() override { return StringRef(); }
71 IdentifierIterator *IdentifierInfoLookup::getIdentifiers() {
72 return new EmptyLookupIterator();
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 KEYNOOPENCL = 0x02000,
110 WCHARSUPPORT = 0x04000,
111 HALFSUPPORT = 0x08000,
112 KEYCONCEPTS = 0x10000,
114 KEYZVECTOR = 0x40000,
115 KEYCOROUTINES = 0x80000,
116 KEYALL = (0xfffff & ~KEYNOMS18 &
117 ~KEYNOOPENCL) // KEYNOMS18 and KEYNOOPENCL are used to exclude.
120 /// \brief How a keyword is treated in the selected standard.
122 KS_Disabled, // Disabled
123 KS_Extension, // Is an extension
124 KS_Enabled, // Enabled
125 KS_Future // Is a keyword in future standard
129 /// \brief Translates flags as specified in TokenKinds.def into keyword status
130 /// in the given language standard.
131 static KeywordStatus getKeywordStatus(const LangOptions &LangOpts,
133 if (Flags == KEYALL) return KS_Enabled;
134 if (LangOpts.CPlusPlus && (Flags & KEYCXX)) return KS_Enabled;
135 if (LangOpts.CPlusPlus11 && (Flags & KEYCXX11)) return KS_Enabled;
136 if (LangOpts.C99 && (Flags & KEYC99)) return KS_Enabled;
137 if (LangOpts.GNUKeywords && (Flags & KEYGNU)) return KS_Extension;
138 if (LangOpts.MicrosoftExt && (Flags & KEYMS)) return KS_Extension;
139 if (LangOpts.Borland && (Flags & KEYBORLAND)) return KS_Extension;
140 if (LangOpts.Bool && (Flags & BOOLSUPPORT)) return KS_Enabled;
141 if (LangOpts.Half && (Flags & HALFSUPPORT)) return KS_Enabled;
142 if (LangOpts.WChar && (Flags & WCHARSUPPORT)) return KS_Enabled;
143 if (LangOpts.AltiVec && (Flags & KEYALTIVEC)) return KS_Enabled;
144 if (LangOpts.OpenCL && (Flags & KEYOPENCL)) return KS_Enabled;
145 if (!LangOpts.CPlusPlus && (Flags & KEYNOCXX)) return KS_Enabled;
146 if (LangOpts.C11 && (Flags & KEYC11)) return KS_Enabled;
147 // We treat bridge casts as objective-C keywords so we can warn on them
149 if (LangOpts.ObjC2 && (Flags & KEYARC)) return KS_Enabled;
150 if (LangOpts.ConceptsTS && (Flags & KEYCONCEPTS)) return KS_Enabled;
151 if (LangOpts.ObjC2 && (Flags & KEYOBJC2)) return KS_Enabled;
152 if (LangOpts.Coroutines && (Flags & KEYCOROUTINES)) return KS_Enabled;
153 if (LangOpts.CPlusPlus && (Flags & KEYCXX11)) return KS_Future;
157 /// AddKeyword - This method is used to associate a token ID with specific
158 /// identifiers because they are language keywords. This causes the lexer to
159 /// automatically map matching identifiers to specialized token codes.
160 static void AddKeyword(StringRef Keyword,
161 tok::TokenKind TokenCode, unsigned Flags,
162 const LangOptions &LangOpts, IdentifierTable &Table) {
163 KeywordStatus AddResult = getKeywordStatus(LangOpts, Flags);
165 // Don't add this keyword under MSVCCompat.
166 if (LangOpts.MSVCCompat && (Flags & KEYNOMS18) &&
167 !LangOpts.isCompatibleWithMSVC(LangOptions::MSVC2015))
170 // Don't add this keyword under OpenCL.
171 if (LangOpts.OpenCL && (Flags & KEYNOOPENCL))
174 // Don't add this keyword if disabled in this language.
175 if (AddResult == KS_Disabled) return;
177 IdentifierInfo &Info =
178 Table.get(Keyword, AddResult == KS_Future ? tok::identifier : TokenCode);
179 Info.setIsExtensionToken(AddResult == KS_Extension);
180 Info.setIsFutureCompatKeyword(AddResult == KS_Future);
183 /// AddCXXOperatorKeyword - Register a C++ operator keyword alternative
185 static void AddCXXOperatorKeyword(StringRef Keyword,
186 tok::TokenKind TokenCode,
187 IdentifierTable &Table) {
188 IdentifierInfo &Info = Table.get(Keyword, TokenCode);
189 Info.setIsCPlusPlusOperatorKeyword();
192 /// AddObjCKeyword - Register an Objective-C \@keyword like "class" "selector"
194 static void AddObjCKeyword(StringRef Name,
195 tok::ObjCKeywordKind ObjCID,
196 IdentifierTable &Table) {
197 Table.get(Name).setObjCKeywordID(ObjCID);
200 /// AddKeywords - Add all keywords to the symbol table.
202 void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {
203 // Add keywords and tokens for the current language.
204 #define KEYWORD(NAME, FLAGS) \
205 AddKeyword(StringRef(#NAME), tok::kw_ ## NAME, \
206 FLAGS, LangOpts, *this);
207 #define ALIAS(NAME, TOK, FLAGS) \
208 AddKeyword(StringRef(NAME), tok::kw_ ## TOK, \
209 FLAGS, LangOpts, *this);
210 #define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \
211 if (LangOpts.CXXOperatorNames) \
212 AddCXXOperatorKeyword(StringRef(#NAME), tok::ALIAS, *this);
213 #define OBJC1_AT_KEYWORD(NAME) \
214 if (LangOpts.ObjC1) \
215 AddObjCKeyword(StringRef(#NAME), tok::objc_##NAME, *this);
216 #define OBJC2_AT_KEYWORD(NAME) \
217 if (LangOpts.ObjC2) \
218 AddObjCKeyword(StringRef(#NAME), tok::objc_##NAME, *this);
219 #define TESTING_KEYWORD(NAME, FLAGS)
220 #include "clang/Basic/TokenKinds.def"
222 if (LangOpts.ParseUnknownAnytype)
223 AddKeyword("__unknown_anytype", tok::kw___unknown_anytype, KEYALL,
226 if (LangOpts.DeclSpecKeyword)
227 AddKeyword("__declspec", tok::kw___declspec, KEYALL, LangOpts, *this);
230 /// \brief Checks if the specified token kind represents a keyword in the
231 /// specified language.
232 /// \returns Status of the keyword in the language.
233 static KeywordStatus getTokenKwStatus(const LangOptions &LangOpts,
236 #define KEYWORD(NAME, FLAGS) \
237 case tok::kw_##NAME: return getKeywordStatus(LangOpts, FLAGS);
238 #include "clang/Basic/TokenKinds.def"
239 default: return KS_Disabled;
243 /// \brief Returns true if the identifier represents a keyword in the
244 /// specified language.
245 bool IdentifierInfo::isKeyword(const LangOptions &LangOpts) {
246 switch (getTokenKwStatus(LangOpts, getTokenID())) {
255 tok::PPKeywordKind IdentifierInfo::getPPKeywordID() const {
256 // We use a perfect hash function here involving the length of the keyword,
257 // the first and third character. For preprocessor ID's there are no
258 // collisions (if there were, the switch below would complain about duplicate
259 // case values). Note that this depends on 'if' being null terminated.
261 #define HASH(LEN, FIRST, THIRD) \
262 (LEN << 5) + (((FIRST-'a') + (THIRD-'a')) & 31)
263 #define CASE(LEN, FIRST, THIRD, NAME) \
264 case HASH(LEN, FIRST, THIRD): \
265 return memcmp(Name, #NAME, LEN) ? tok::pp_not_keyword : tok::pp_ ## NAME
267 unsigned Len = getLength();
268 if (Len < 2) return tok::pp_not_keyword;
269 const char *Name = getNameStart();
270 switch (HASH(Len, Name[0], Name[2])) {
271 default: return tok::pp_not_keyword;
272 CASE( 2, 'i', '\0', if);
273 CASE( 4, 'e', 'i', elif);
274 CASE( 4, 'e', 's', else);
275 CASE( 4, 'l', 'n', line);
276 CASE( 4, 's', 'c', sccs);
277 CASE( 5, 'e', 'd', endif);
278 CASE( 5, 'e', 'r', error);
279 CASE( 5, 'i', 'e', ident);
280 CASE( 5, 'i', 'd', ifdef);
281 CASE( 5, 'u', 'd', undef);
283 CASE( 6, 'a', 's', assert);
284 CASE( 6, 'd', 'f', define);
285 CASE( 6, 'i', 'n', ifndef);
286 CASE( 6, 'i', 'p', import);
287 CASE( 6, 'p', 'a', pragma);
289 CASE( 7, 'd', 'f', defined);
290 CASE( 7, 'i', 'c', include);
291 CASE( 7, 'w', 'r', warning);
293 CASE( 8, 'u', 'a', unassert);
294 CASE(12, 'i', 'c', include_next);
296 CASE(14, '_', 'p', __public_macro);
298 CASE(15, '_', 'p', __private_macro);
300 CASE(16, '_', 'i', __include_macros);
306 //===----------------------------------------------------------------------===//
307 // Stats Implementation
308 //===----------------------------------------------------------------------===//
310 /// PrintStats - Print statistics about how well the identifier table is doing
311 /// at hashing identifiers.
312 void IdentifierTable::PrintStats() const {
313 unsigned NumBuckets = HashTable.getNumBuckets();
314 unsigned NumIdentifiers = HashTable.getNumItems();
315 unsigned NumEmptyBuckets = NumBuckets-NumIdentifiers;
316 unsigned AverageIdentifierSize = 0;
317 unsigned MaxIdentifierLength = 0;
319 // TODO: Figure out maximum times an identifier had to probe for -stats.
320 for (llvm::StringMap<IdentifierInfo*, llvm::BumpPtrAllocator>::const_iterator
321 I = HashTable.begin(), E = HashTable.end(); I != E; ++I) {
322 unsigned IdLen = I->getKeyLength();
323 AverageIdentifierSize += IdLen;
324 if (MaxIdentifierLength < IdLen)
325 MaxIdentifierLength = IdLen;
328 fprintf(stderr, "\n*** Identifier Table Stats:\n");
329 fprintf(stderr, "# Identifiers: %d\n", NumIdentifiers);
330 fprintf(stderr, "# Empty Buckets: %d\n", NumEmptyBuckets);
331 fprintf(stderr, "Hash density (#identifiers per bucket): %f\n",
332 NumIdentifiers/(double)NumBuckets);
333 fprintf(stderr, "Ave identifier length: %f\n",
334 (AverageIdentifierSize/(double)NumIdentifiers));
335 fprintf(stderr, "Max identifier length: %d\n", MaxIdentifierLength);
337 // Compute statistics about the memory allocated for identifiers.
338 HashTable.getAllocator().PrintStats();
341 //===----------------------------------------------------------------------===//
342 // SelectorTable Implementation
343 //===----------------------------------------------------------------------===//
345 unsigned llvm::DenseMapInfo<clang::Selector>::getHashValue(clang::Selector S) {
346 return DenseMapInfo<void*>::getHashValue(S.getAsOpaquePtr());
350 /// MultiKeywordSelector - One of these variable length records is kept for each
351 /// selector containing more than one keyword. We use a folding set
352 /// to unique aggregate names (keyword selectors in ObjC parlance). Access to
353 /// this class is provided strictly through Selector.
354 class MultiKeywordSelector
355 : public DeclarationNameExtra, public llvm::FoldingSetNode {
356 MultiKeywordSelector(unsigned nKeys) {
357 ExtraKindOrNumArgs = NUM_EXTRA_KINDS + nKeys;
360 // Constructor for keyword selectors.
361 MultiKeywordSelector(unsigned nKeys, IdentifierInfo **IIV) {
362 assert((nKeys > 1) && "not a multi-keyword selector");
363 ExtraKindOrNumArgs = NUM_EXTRA_KINDS + nKeys;
365 // Fill in the trailing keyword array.
366 IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(this+1);
367 for (unsigned i = 0; i != nKeys; ++i)
371 // getName - Derive the full selector name and return it.
372 std::string getName() const;
374 unsigned getNumArgs() const { return ExtraKindOrNumArgs - NUM_EXTRA_KINDS; }
376 typedef IdentifierInfo *const *keyword_iterator;
377 keyword_iterator keyword_begin() const {
378 return reinterpret_cast<keyword_iterator>(this+1);
380 keyword_iterator keyword_end() const {
381 return keyword_begin()+getNumArgs();
383 IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const {
384 assert(i < getNumArgs() && "getIdentifierInfoForSlot(): illegal index");
385 return keyword_begin()[i];
387 static void Profile(llvm::FoldingSetNodeID &ID,
388 keyword_iterator ArgTys, unsigned NumArgs) {
389 ID.AddInteger(NumArgs);
390 for (unsigned i = 0; i != NumArgs; ++i)
391 ID.AddPointer(ArgTys[i]);
393 void Profile(llvm::FoldingSetNodeID &ID) {
394 Profile(ID, keyword_begin(), getNumArgs());
397 } // end namespace clang.
399 unsigned Selector::getNumArgs() const {
400 unsigned IIF = getIdentifierInfoFlag();
405 // We point to a MultiKeywordSelector.
406 MultiKeywordSelector *SI = getMultiKeywordSelector();
407 return SI->getNumArgs();
410 IdentifierInfo *Selector::getIdentifierInfoForSlot(unsigned argIndex) const {
411 if (getIdentifierInfoFlag() < MultiArg) {
412 assert(argIndex == 0 && "illegal keyword index");
413 return getAsIdentifierInfo();
415 // We point to a MultiKeywordSelector.
416 MultiKeywordSelector *SI = getMultiKeywordSelector();
417 return SI->getIdentifierInfoForSlot(argIndex);
420 StringRef Selector::getNameForSlot(unsigned int argIndex) const {
421 IdentifierInfo *II = getIdentifierInfoForSlot(argIndex);
422 return II? II->getName() : StringRef();
425 std::string MultiKeywordSelector::getName() const {
426 SmallString<256> Str;
427 llvm::raw_svector_ostream OS(Str);
428 for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) {
430 OS << (*I)->getName();
437 std::string Selector::getAsString() const {
439 return "<null selector>";
441 if (getIdentifierInfoFlag() < MultiArg) {
442 IdentifierInfo *II = getAsIdentifierInfo();
444 // If the number of arguments is 0 then II is guaranteed to not be null.
445 if (getNumArgs() == 0)
446 return II->getName();
451 return II->getName().str() + ":";
454 // We have a multiple keyword selector.
455 return getMultiKeywordSelector()->getName();
458 void Selector::print(llvm::raw_ostream &OS) const {
462 /// Interpreting the given string using the normal CamelCase
463 /// conventions, determine whether the given string starts with the
464 /// given "word", which is assumed to end in a lowercase letter.
465 static bool startsWithWord(StringRef name, StringRef word) {
466 if (name.size() < word.size()) return false;
467 return ((name.size() == word.size() || !isLowercase(name[word.size()])) &&
468 name.startswith(word));
471 ObjCMethodFamily Selector::getMethodFamilyImpl(Selector sel) {
472 IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
473 if (!first) return OMF_None;
475 StringRef name = first->getName();
476 if (sel.isUnarySelector()) {
477 if (name == "autorelease") return OMF_autorelease;
478 if (name == "dealloc") return OMF_dealloc;
479 if (name == "finalize") return OMF_finalize;
480 if (name == "release") return OMF_release;
481 if (name == "retain") return OMF_retain;
482 if (name == "retainCount") return OMF_retainCount;
483 if (name == "self") return OMF_self;
484 if (name == "initialize") return OMF_initialize;
487 if (name == "performSelector") return OMF_performSelector;
489 // The other method families may begin with a prefix of underscores.
490 while (!name.empty() && name.front() == '_')
491 name = name.substr(1);
493 if (name.empty()) return OMF_None;
494 switch (name.front()) {
496 if (startsWithWord(name, "alloc")) return OMF_alloc;
499 if (startsWithWord(name, "copy")) return OMF_copy;
502 if (startsWithWord(name, "init")) return OMF_init;
505 if (startsWithWord(name, "mutableCopy")) return OMF_mutableCopy;
508 if (startsWithWord(name, "new")) return OMF_new;
517 ObjCInstanceTypeFamily Selector::getInstTypeMethodFamily(Selector sel) {
518 IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
519 if (!first) return OIT_None;
521 StringRef name = first->getName();
523 if (name.empty()) return OIT_None;
524 switch (name.front()) {
526 if (startsWithWord(name, "array")) return OIT_Array;
529 if (startsWithWord(name, "default")) return OIT_ReturnsSelf;
530 if (startsWithWord(name, "dictionary")) return OIT_Dictionary;
533 if (startsWithWord(name, "shared")) return OIT_ReturnsSelf;
534 if (startsWithWord(name, "standard")) return OIT_Singleton;
536 if (startsWithWord(name, "init")) return OIT_Init;
543 ObjCStringFormatFamily Selector::getStringFormatFamilyImpl(Selector sel) {
544 IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
545 if (!first) return SFF_None;
547 StringRef name = first->getName();
549 switch (name.front()) {
551 if (name == "appendFormat") return SFF_NSString;
555 if (name == "initWithFormat") return SFF_NSString;
559 if (name == "localizedStringWithFormat") return SFF_NSString;
563 if (name == "stringByAppendingFormat" ||
564 name == "stringWithFormat") return SFF_NSString;
571 struct SelectorTableImpl {
572 llvm::FoldingSet<MultiKeywordSelector> Table;
573 llvm::BumpPtrAllocator Allocator;
575 } // end anonymous namespace.
577 static SelectorTableImpl &getSelectorTableImpl(void *P) {
578 return *static_cast<SelectorTableImpl*>(P);
582 SelectorTable::constructSetterName(StringRef Name) {
583 SmallString<64> SetterName("set");
585 SetterName[3] = toUppercase(SetterName[3]);
590 SelectorTable::constructSetterSelector(IdentifierTable &Idents,
591 SelectorTable &SelTable,
592 const IdentifierInfo *Name) {
593 IdentifierInfo *SetterName =
594 &Idents.get(constructSetterName(Name->getName()));
595 return SelTable.getUnarySelector(SetterName);
598 size_t SelectorTable::getTotalMemory() const {
599 SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl);
600 return SelTabImpl.Allocator.getTotalMemory();
603 Selector SelectorTable::getSelector(unsigned nKeys, IdentifierInfo **IIV) {
605 return Selector(IIV[0], nKeys);
607 SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl);
609 // Unique selector, to guarantee there is one per name.
610 llvm::FoldingSetNodeID ID;
611 MultiKeywordSelector::Profile(ID, IIV, nKeys);
613 void *InsertPos = nullptr;
614 if (MultiKeywordSelector *SI =
615 SelTabImpl.Table.FindNodeOrInsertPos(ID, InsertPos))
618 // MultiKeywordSelector objects are not allocated with new because they have a
619 // variable size array (for parameter types) at the end of them.
620 unsigned Size = sizeof(MultiKeywordSelector) + nKeys*sizeof(IdentifierInfo *);
621 MultiKeywordSelector *SI =
622 (MultiKeywordSelector*)SelTabImpl.Allocator.Allocate(Size,
623 llvm::alignOf<MultiKeywordSelector>());
624 new (SI) MultiKeywordSelector(nKeys, IIV);
625 SelTabImpl.Table.InsertNode(SI, InsertPos);
629 SelectorTable::SelectorTable() {
630 Impl = new SelectorTableImpl();
633 SelectorTable::~SelectorTable() {
634 delete &getSelectorTableImpl(Impl);
637 const char *clang::getOperatorSpelling(OverloadedOperatorKind Operator) {
640 case NUM_OVERLOADED_OPERATORS:
643 #define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
644 case OO_##Name: return Spelling;
645 #include "clang/Basic/OperatorKinds.def"
648 llvm_unreachable("Invalid OverloadedOperatorKind!");
651 StringRef clang::getNullabilitySpelling(NullabilityKind kind,
652 bool isContextSensitive) {
654 case NullabilityKind::NonNull:
655 return isContextSensitive ? "nonnull" : "_Nonnull";
657 case NullabilityKind::Nullable:
658 return isContextSensitive ? "nullable" : "_Nullable";
660 case NullabilityKind::Unspecified:
661 return isContextSensitive ? "null_unspecified" : "_Null_unspecified";
663 llvm_unreachable("Unknown nullability kind.");