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/CharInfo.h"
17 #include "clang/Basic/LangOptions.h"
18 #include "clang/Basic/OperatorKinds.h"
19 #include "clang/Basic/Specifiers.h"
20 #include "clang/Basic/TokenKinds.h"
21 #include "llvm/ADT/DenseMapInfo.h"
22 #include "llvm/ADT/FoldingSet.h"
23 #include "llvm/ADT/SmallString.h"
24 #include "llvm/ADT/StringMap.h"
25 #include "llvm/ADT/StringRef.h"
26 #include "llvm/Support/Allocator.h"
27 #include "llvm/Support/ErrorHandling.h"
28 #include "llvm/Support/raw_ostream.h"
29 #include <cassert>
30 #include <cstdio>
31 #include <cstring>
32 #include <string>
33 
34 using namespace clang;
35 
36 //===----------------------------------------------------------------------===//
37 // IdentifierInfo Implementation
38 //===----------------------------------------------------------------------===//
39 
40 IdentifierInfo::IdentifierInfo() {
41   TokenID = tok::identifier;
42   ObjCOrBuiltinID = 0;
43   HasMacro = false;
44   HadMacro = false;
45   IsExtension = false;
46   IsFutureCompatKeyword = false;
47   IsPoisoned = false;
48   IsCPPOperatorKeyword = false;
49   NeedsHandleIdentifier = false;
50   IsFromAST = false;
51   ChangedAfterLoad = false;
52   FEChangedAfterLoad = false;
53   RevertedTokenID = false;
54   OutOfDate = false;
55   IsModulesImport = false;
56 }
57 
58 //===----------------------------------------------------------------------===//
59 // IdentifierTable Implementation
60 //===----------------------------------------------------------------------===//
61 
62 IdentifierIterator::~IdentifierIterator() = default;
63 
64 IdentifierInfoLookup::~IdentifierInfoLookup() = default;
65 
66 namespace {
67 
68 /// A simple identifier lookup iterator that represents an
69 /// empty sequence of identifiers.
70 class EmptyLookupIterator : public IdentifierIterator
71 {
72 public:
73   StringRef Next() override { return StringRef(); }
74 };
75 
76 } // namespace
77 
78 IdentifierIterator *IdentifierInfoLookup::getIdentifiers() {
79   return new EmptyLookupIterator();
80 }
81 
82 IdentifierTable::IdentifierTable(IdentifierInfoLookup *ExternalLookup)
83     : HashTable(8192), // Start with space for 8K identifiers.
84       ExternalLookup(ExternalLookup) {}
85 
86 IdentifierTable::IdentifierTable(const LangOptions &LangOpts,
87                                  IdentifierInfoLookup *ExternalLookup)
88     : IdentifierTable(ExternalLookup) {
89   // Populate the identifier table with info about keywords for the current
90   // language.
91   AddKeywords(LangOpts);
92 }
93 
94 //===----------------------------------------------------------------------===//
95 // Language Keyword Implementation
96 //===----------------------------------------------------------------------===//
97 
98 // Constants for TokenKinds.def
99 namespace {
100 
101   enum {
102     KEYC99        = 0x1,
103     KEYCXX        = 0x2,
104     KEYCXX11      = 0x4,
105     KEYGNU        = 0x8,
106     KEYMS         = 0x10,
107     BOOLSUPPORT   = 0x20,
108     KEYALTIVEC    = 0x40,
109     KEYNOCXX      = 0x80,
110     KEYBORLAND    = 0x100,
111     KEYOPENCLC    = 0x200,
112     KEYC11        = 0x400,
113     KEYNOMS18     = 0x800,
114     KEYNOOPENCL   = 0x1000,
115     WCHARSUPPORT  = 0x2000,
116     HALFSUPPORT   = 0x4000,
117     CHAR8SUPPORT  = 0x8000,
118     KEYCONCEPTS   = 0x10000,
119     KEYOBJC       = 0x20000,
120     KEYZVECTOR    = 0x40000,
121     KEYCOROUTINES = 0x80000,
122     KEYMODULES    = 0x100000,
123     KEYCXX2A      = 0x200000,
124     KEYOPENCLCXX  = 0x400000,
125     KEYALLCXX = KEYCXX | KEYCXX11 | KEYCXX2A,
126     KEYALL = (0xffffff & ~KEYNOMS18 &
127               ~KEYNOOPENCL) // KEYNOMS18 and KEYNOOPENCL are used to exclude.
128   };
129 
130   /// How a keyword is treated in the selected standard.
131   enum KeywordStatus {
132     KS_Disabled,    // Disabled
133     KS_Extension,   // Is an extension
134     KS_Enabled,     // Enabled
135     KS_Future       // Is a keyword in future standard
136   };
137 
138 } // namespace
139 
140 /// Translates flags as specified in TokenKinds.def into keyword status
141 /// in the given language standard.
142 static KeywordStatus getKeywordStatus(const LangOptions &LangOpts,
143                                       unsigned Flags) {
144   if (Flags == KEYALL) return KS_Enabled;
145   if (LangOpts.CPlusPlus && (Flags & KEYCXX)) return KS_Enabled;
146   if (LangOpts.CPlusPlus11 && (Flags & KEYCXX11)) return KS_Enabled;
147   if (LangOpts.CPlusPlus2a && (Flags & KEYCXX2A)) return KS_Enabled;
148   if (LangOpts.C99 && (Flags & KEYC99)) return KS_Enabled;
149   if (LangOpts.GNUKeywords && (Flags & KEYGNU)) return KS_Extension;
150   if (LangOpts.MicrosoftExt && (Flags & KEYMS)) return KS_Extension;
151   if (LangOpts.Borland && (Flags & KEYBORLAND)) return KS_Extension;
152   if (LangOpts.Bool && (Flags & BOOLSUPPORT)) return KS_Enabled;
153   if (LangOpts.Half && (Flags & HALFSUPPORT)) return KS_Enabled;
154   if (LangOpts.WChar && (Flags & WCHARSUPPORT)) return KS_Enabled;
155   if (LangOpts.Char8 && (Flags & CHAR8SUPPORT)) return KS_Enabled;
156   if (LangOpts.AltiVec && (Flags & KEYALTIVEC)) return KS_Enabled;
157   if (LangOpts.ZVector && (Flags & KEYZVECTOR)) return KS_Enabled;
158   if (LangOpts.OpenCL && !LangOpts.OpenCLCPlusPlus && (Flags & KEYOPENCLC))
159     return KS_Enabled;
160   if (LangOpts.OpenCLCPlusPlus && (Flags & KEYOPENCLCXX)) return KS_Enabled;
161   if (!LangOpts.CPlusPlus && (Flags & KEYNOCXX)) return KS_Enabled;
162   if (LangOpts.C11 && (Flags & KEYC11)) return KS_Enabled;
163   // We treat bridge casts as objective-C keywords so we can warn on them
164   // in non-arc mode.
165   if (LangOpts.ObjC && (Flags & KEYOBJC)) return KS_Enabled;
166   if (LangOpts.ConceptsTS && (Flags & KEYCONCEPTS)) return KS_Enabled;
167   if (LangOpts.CoroutinesTS && (Flags & KEYCOROUTINES)) return KS_Enabled;
168   if (LangOpts.ModulesTS && (Flags & KEYMODULES)) return KS_Enabled;
169   if (LangOpts.CPlusPlus && (Flags & KEYALLCXX)) return KS_Future;
170   return KS_Disabled;
171 }
172 
173 /// AddKeyword - This method is used to associate a token ID with specific
174 /// identifiers because they are language keywords.  This causes the lexer to
175 /// automatically map matching identifiers to specialized token codes.
176 static void AddKeyword(StringRef Keyword,
177                        tok::TokenKind TokenCode, unsigned Flags,
178                        const LangOptions &LangOpts, IdentifierTable &Table) {
179   KeywordStatus AddResult = getKeywordStatus(LangOpts, Flags);
180 
181   // Don't add this keyword under MSVCCompat.
182   if (LangOpts.MSVCCompat && (Flags & KEYNOMS18) &&
183       !LangOpts.isCompatibleWithMSVC(LangOptions::MSVC2015))
184     return;
185 
186   // Don't add this keyword under OpenCL.
187   if (LangOpts.OpenCL && (Flags & KEYNOOPENCL))
188     return;
189 
190   // Don't add this keyword if disabled in this language.
191   if (AddResult == KS_Disabled) return;
192 
193   IdentifierInfo &Info =
194       Table.get(Keyword, AddResult == KS_Future ? tok::identifier : TokenCode);
195   Info.setIsExtensionToken(AddResult == KS_Extension);
196   Info.setIsFutureCompatKeyword(AddResult == KS_Future);
197 }
198 
199 /// AddCXXOperatorKeyword - Register a C++ operator keyword alternative
200 /// representations.
201 static void AddCXXOperatorKeyword(StringRef Keyword,
202                                   tok::TokenKind TokenCode,
203                                   IdentifierTable &Table) {
204   IdentifierInfo &Info = Table.get(Keyword, TokenCode);
205   Info.setIsCPlusPlusOperatorKeyword();
206 }
207 
208 /// AddObjCKeyword - Register an Objective-C \@keyword like "class" "selector"
209 /// or "property".
210 static void AddObjCKeyword(StringRef Name,
211                            tok::ObjCKeywordKind ObjCID,
212                            IdentifierTable &Table) {
213   Table.get(Name).setObjCKeywordID(ObjCID);
214 }
215 
216 /// AddKeywords - Add all keywords to the symbol table.
217 ///
218 void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {
219   // Add keywords and tokens for the current language.
220 #define KEYWORD(NAME, FLAGS) \
221   AddKeyword(StringRef(#NAME), tok::kw_ ## NAME,  \
222              FLAGS, LangOpts, *this);
223 #define ALIAS(NAME, TOK, FLAGS) \
224   AddKeyword(StringRef(NAME), tok::kw_ ## TOK,  \
225              FLAGS, LangOpts, *this);
226 #define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \
227   if (LangOpts.CXXOperatorNames)          \
228     AddCXXOperatorKeyword(StringRef(#NAME), tok::ALIAS, *this);
229 #define OBJC_AT_KEYWORD(NAME)  \
230   if (LangOpts.ObjC)           \
231     AddObjCKeyword(StringRef(#NAME), tok::objc_##NAME, *this);
232 #define TESTING_KEYWORD(NAME, FLAGS)
233 #include "clang/Basic/TokenKinds.def"
234 
235   if (LangOpts.ParseUnknownAnytype)
236     AddKeyword("__unknown_anytype", tok::kw___unknown_anytype, KEYALL,
237                LangOpts, *this);
238 
239   if (LangOpts.DeclSpecKeyword)
240     AddKeyword("__declspec", tok::kw___declspec, KEYALL, LangOpts, *this);
241 
242   // Add the '_experimental_modules_import' contextual keyword.
243   get("import").setModulesImport(true);
244 }
245 
246 /// Checks if the specified token kind represents a keyword in the
247 /// specified language.
248 /// \returns Status of the keyword in the language.
249 static KeywordStatus getTokenKwStatus(const LangOptions &LangOpts,
250                                       tok::TokenKind K) {
251   switch (K) {
252 #define KEYWORD(NAME, FLAGS) \
253   case tok::kw_##NAME: return getKeywordStatus(LangOpts, FLAGS);
254 #include "clang/Basic/TokenKinds.def"
255   default: return KS_Disabled;
256   }
257 }
258 
259 /// Returns true if the identifier represents a keyword in the
260 /// specified language.
261 bool IdentifierInfo::isKeyword(const LangOptions &LangOpts) const {
262   switch (getTokenKwStatus(LangOpts, getTokenID())) {
263   case KS_Enabled:
264   case KS_Extension:
265     return true;
266   default:
267     return false;
268   }
269 }
270 
271 /// Returns true if the identifier represents a C++ keyword in the
272 /// specified language.
273 bool IdentifierInfo::isCPlusPlusKeyword(const LangOptions &LangOpts) const {
274   if (!LangOpts.CPlusPlus || !isKeyword(LangOpts))
275     return false;
276   // This is a C++ keyword if this identifier is not a keyword when checked
277   // using LangOptions without C++ support.
278   LangOptions LangOptsNoCPP = LangOpts;
279   LangOptsNoCPP.CPlusPlus = false;
280   LangOptsNoCPP.CPlusPlus11 = false;
281   LangOptsNoCPP.CPlusPlus2a = false;
282   return !isKeyword(LangOptsNoCPP);
283 }
284 
285 tok::PPKeywordKind IdentifierInfo::getPPKeywordID() const {
286   // We use a perfect hash function here involving the length of the keyword,
287   // the first and third character.  For preprocessor ID's there are no
288   // collisions (if there were, the switch below would complain about duplicate
289   // case values).  Note that this depends on 'if' being null terminated.
290 
291 #define HASH(LEN, FIRST, THIRD) \
292   (LEN << 5) + (((FIRST-'a') + (THIRD-'a')) & 31)
293 #define CASE(LEN, FIRST, THIRD, NAME) \
294   case HASH(LEN, FIRST, THIRD): \
295     return memcmp(Name, #NAME, LEN) ? tok::pp_not_keyword : tok::pp_ ## NAME
296 
297   unsigned Len = getLength();
298   if (Len < 2) return tok::pp_not_keyword;
299   const char *Name = getNameStart();
300   switch (HASH(Len, Name[0], Name[2])) {
301   default: return tok::pp_not_keyword;
302   CASE( 2, 'i', '\0', if);
303   CASE( 4, 'e', 'i', elif);
304   CASE( 4, 'e', 's', else);
305   CASE( 4, 'l', 'n', line);
306   CASE( 4, 's', 'c', sccs);
307   CASE( 5, 'e', 'd', endif);
308   CASE( 5, 'e', 'r', error);
309   CASE( 5, 'i', 'e', ident);
310   CASE( 5, 'i', 'd', ifdef);
311   CASE( 5, 'u', 'd', undef);
312 
313   CASE( 6, 'a', 's', assert);
314   CASE( 6, 'd', 'f', define);
315   CASE( 6, 'i', 'n', ifndef);
316   CASE( 6, 'i', 'p', import);
317   CASE( 6, 'p', 'a', pragma);
318 
319   CASE( 7, 'd', 'f', defined);
320   CASE( 7, 'i', 'c', include);
321   CASE( 7, 'w', 'r', warning);
322 
323   CASE( 8, 'u', 'a', unassert);
324   CASE(12, 'i', 'c', include_next);
325 
326   CASE(14, '_', 'p', __public_macro);
327 
328   CASE(15, '_', 'p', __private_macro);
329 
330   CASE(16, '_', 'i', __include_macros);
331 #undef CASE
332 #undef HASH
333   }
334 }
335 
336 //===----------------------------------------------------------------------===//
337 // Stats Implementation
338 //===----------------------------------------------------------------------===//
339 
340 /// PrintStats - Print statistics about how well the identifier table is doing
341 /// at hashing identifiers.
342 void IdentifierTable::PrintStats() const {
343   unsigned NumBuckets = HashTable.getNumBuckets();
344   unsigned NumIdentifiers = HashTable.getNumItems();
345   unsigned NumEmptyBuckets = NumBuckets-NumIdentifiers;
346   unsigned AverageIdentifierSize = 0;
347   unsigned MaxIdentifierLength = 0;
348 
349   // TODO: Figure out maximum times an identifier had to probe for -stats.
350   for (llvm::StringMap<IdentifierInfo*, llvm::BumpPtrAllocator>::const_iterator
351        I = HashTable.begin(), E = HashTable.end(); I != E; ++I) {
352     unsigned IdLen = I->getKeyLength();
353     AverageIdentifierSize += IdLen;
354     if (MaxIdentifierLength < IdLen)
355       MaxIdentifierLength = IdLen;
356   }
357 
358   fprintf(stderr, "\n*** Identifier Table Stats:\n");
359   fprintf(stderr, "# Identifiers:   %d\n", NumIdentifiers);
360   fprintf(stderr, "# Empty Buckets: %d\n", NumEmptyBuckets);
361   fprintf(stderr, "Hash density (#identifiers per bucket): %f\n",
362           NumIdentifiers/(double)NumBuckets);
363   fprintf(stderr, "Ave identifier length: %f\n",
364           (AverageIdentifierSize/(double)NumIdentifiers));
365   fprintf(stderr, "Max identifier length: %d\n", MaxIdentifierLength);
366 
367   // Compute statistics about the memory allocated for identifiers.
368   HashTable.getAllocator().PrintStats();
369 }
370 
371 //===----------------------------------------------------------------------===//
372 // SelectorTable Implementation
373 //===----------------------------------------------------------------------===//
374 
375 unsigned llvm::DenseMapInfo<clang::Selector>::getHashValue(clang::Selector S) {
376   return DenseMapInfo<void*>::getHashValue(S.getAsOpaquePtr());
377 }
378 
379 namespace clang {
380 
381 /// One of these variable length records is kept for each
382 /// selector containing more than one keyword. We use a folding set
383 /// to unique aggregate names (keyword selectors in ObjC parlance). Access to
384 /// this class is provided strictly through Selector.
385 class alignas(IdentifierInfoAlignment) MultiKeywordSelector
386     : public detail::DeclarationNameExtra,
387       public llvm::FoldingSetNode {
388   MultiKeywordSelector(unsigned nKeys) : DeclarationNameExtra(nKeys) {}
389 
390 public:
391   // Constructor for keyword selectors.
392   MultiKeywordSelector(unsigned nKeys, IdentifierInfo **IIV)
393       : DeclarationNameExtra(nKeys) {
394     assert((nKeys > 1) && "not a multi-keyword selector");
395 
396     // Fill in the trailing keyword array.
397     IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(this + 1);
398     for (unsigned i = 0; i != nKeys; ++i)
399       KeyInfo[i] = IIV[i];
400   }
401 
402   // getName - Derive the full selector name and return it.
403   std::string getName() const;
404 
405   using DeclarationNameExtra::getNumArgs;
406 
407   using keyword_iterator = IdentifierInfo *const *;
408 
409   keyword_iterator keyword_begin() const {
410     return reinterpret_cast<keyword_iterator>(this + 1);
411   }
412 
413   keyword_iterator keyword_end() const {
414     return keyword_begin() + getNumArgs();
415   }
416 
417   IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const {
418     assert(i < getNumArgs() && "getIdentifierInfoForSlot(): illegal index");
419     return keyword_begin()[i];
420   }
421 
422   static void Profile(llvm::FoldingSetNodeID &ID, keyword_iterator ArgTys,
423                       unsigned NumArgs) {
424     ID.AddInteger(NumArgs);
425     for (unsigned i = 0; i != NumArgs; ++i)
426       ID.AddPointer(ArgTys[i]);
427   }
428 
429   void Profile(llvm::FoldingSetNodeID &ID) {
430     Profile(ID, keyword_begin(), getNumArgs());
431   }
432 };
433 
434 } // namespace clang.
435 
436 unsigned Selector::getNumArgs() const {
437   unsigned IIF = getIdentifierInfoFlag();
438   if (IIF <= ZeroArg)
439     return 0;
440   if (IIF == OneArg)
441     return 1;
442   // We point to a MultiKeywordSelector.
443   MultiKeywordSelector *SI = getMultiKeywordSelector();
444   return SI->getNumArgs();
445 }
446 
447 IdentifierInfo *Selector::getIdentifierInfoForSlot(unsigned argIndex) const {
448   if (getIdentifierInfoFlag() < MultiArg) {
449     assert(argIndex == 0 && "illegal keyword index");
450     return getAsIdentifierInfo();
451   }
452 
453   // We point to a MultiKeywordSelector.
454   MultiKeywordSelector *SI = getMultiKeywordSelector();
455   return SI->getIdentifierInfoForSlot(argIndex);
456 }
457 
458 StringRef Selector::getNameForSlot(unsigned int argIndex) const {
459   IdentifierInfo *II = getIdentifierInfoForSlot(argIndex);
460   return II ? II->getName() : StringRef();
461 }
462 
463 std::string MultiKeywordSelector::getName() const {
464   SmallString<256> Str;
465   llvm::raw_svector_ostream OS(Str);
466   for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) {
467     if (*I)
468       OS << (*I)->getName();
469     OS << ':';
470   }
471 
472   return OS.str();
473 }
474 
475 std::string Selector::getAsString() const {
476   if (InfoPtr == 0)
477     return "<null selector>";
478 
479   if (getIdentifierInfoFlag() < MultiArg) {
480     IdentifierInfo *II = getAsIdentifierInfo();
481 
482     if (getNumArgs() == 0) {
483       assert(II && "If the number of arguments is 0 then II is guaranteed to "
484                    "not be null.");
485       return II->getName();
486     }
487 
488     if (!II)
489       return ":";
490 
491     return II->getName().str() + ":";
492   }
493 
494   // We have a multiple keyword selector.
495   return getMultiKeywordSelector()->getName();
496 }
497 
498 void Selector::print(llvm::raw_ostream &OS) const {
499   OS << getAsString();
500 }
501 
502 LLVM_DUMP_METHOD void Selector::dump() const { print(llvm::errs()); }
503 
504 /// Interpreting the given string using the normal CamelCase
505 /// conventions, determine whether the given string starts with the
506 /// given "word", which is assumed to end in a lowercase letter.
507 static bool startsWithWord(StringRef name, StringRef word) {
508   if (name.size() < word.size()) return false;
509   return ((name.size() == word.size() || !isLowercase(name[word.size()])) &&
510           name.startswith(word));
511 }
512 
513 ObjCMethodFamily Selector::getMethodFamilyImpl(Selector sel) {
514   IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
515   if (!first) return OMF_None;
516 
517   StringRef name = first->getName();
518   if (sel.isUnarySelector()) {
519     if (name == "autorelease") return OMF_autorelease;
520     if (name == "dealloc") return OMF_dealloc;
521     if (name == "finalize") return OMF_finalize;
522     if (name == "release") return OMF_release;
523     if (name == "retain") return OMF_retain;
524     if (name == "retainCount") return OMF_retainCount;
525     if (name == "self") return OMF_self;
526     if (name == "initialize") return OMF_initialize;
527   }
528 
529   if (name == "performSelector" || name == "performSelectorInBackground" ||
530       name == "performSelectorOnMainThread")
531     return OMF_performSelector;
532 
533   // The other method families may begin with a prefix of underscores.
534   while (!name.empty() && name.front() == '_')
535     name = name.substr(1);
536 
537   if (name.empty()) return OMF_None;
538   switch (name.front()) {
539   case 'a':
540     if (startsWithWord(name, "alloc")) return OMF_alloc;
541     break;
542   case 'c':
543     if (startsWithWord(name, "copy")) return OMF_copy;
544     break;
545   case 'i':
546     if (startsWithWord(name, "init")) return OMF_init;
547     break;
548   case 'm':
549     if (startsWithWord(name, "mutableCopy")) return OMF_mutableCopy;
550     break;
551   case 'n':
552     if (startsWithWord(name, "new")) return OMF_new;
553     break;
554   default:
555     break;
556   }
557 
558   return OMF_None;
559 }
560 
561 ObjCInstanceTypeFamily Selector::getInstTypeMethodFamily(Selector sel) {
562   IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
563   if (!first) return OIT_None;
564 
565   StringRef name = first->getName();
566 
567   if (name.empty()) return OIT_None;
568   switch (name.front()) {
569     case 'a':
570       if (startsWithWord(name, "array")) return OIT_Array;
571       break;
572     case 'd':
573       if (startsWithWord(name, "default")) return OIT_ReturnsSelf;
574       if (startsWithWord(name, "dictionary")) return OIT_Dictionary;
575       break;
576     case 's':
577       if (startsWithWord(name, "shared")) return OIT_ReturnsSelf;
578       if (startsWithWord(name, "standard")) return OIT_Singleton;
579       break;
580     case 'i':
581       if (startsWithWord(name, "init")) return OIT_Init;
582     default:
583       break;
584   }
585   return OIT_None;
586 }
587 
588 ObjCStringFormatFamily Selector::getStringFormatFamilyImpl(Selector sel) {
589   IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
590   if (!first) return SFF_None;
591 
592   StringRef name = first->getName();
593 
594   switch (name.front()) {
595     case 'a':
596       if (name == "appendFormat") return SFF_NSString;
597       break;
598 
599     case 'i':
600       if (name == "initWithFormat") return SFF_NSString;
601       break;
602 
603     case 'l':
604       if (name == "localizedStringWithFormat") return SFF_NSString;
605       break;
606 
607     case 's':
608       if (name == "stringByAppendingFormat" ||
609           name == "stringWithFormat") return SFF_NSString;
610       break;
611   }
612   return SFF_None;
613 }
614 
615 namespace {
616 
617 struct SelectorTableImpl {
618   llvm::FoldingSet<MultiKeywordSelector> Table;
619   llvm::BumpPtrAllocator Allocator;
620 };
621 
622 } // namespace
623 
624 static SelectorTableImpl &getSelectorTableImpl(void *P) {
625   return *static_cast<SelectorTableImpl*>(P);
626 }
627 
628 SmallString<64>
629 SelectorTable::constructSetterName(StringRef Name) {
630   SmallString<64> SetterName("set");
631   SetterName += Name;
632   SetterName[3] = toUppercase(SetterName[3]);
633   return SetterName;
634 }
635 
636 Selector
637 SelectorTable::constructSetterSelector(IdentifierTable &Idents,
638                                        SelectorTable &SelTable,
639                                        const IdentifierInfo *Name) {
640   IdentifierInfo *SetterName =
641     &Idents.get(constructSetterName(Name->getName()));
642   return SelTable.getUnarySelector(SetterName);
643 }
644 
645 std::string SelectorTable::getPropertyNameFromSetterSelector(Selector Sel) {
646   StringRef Name = Sel.getNameForSlot(0);
647   assert(Name.startswith("set") && "invalid setter name");
648   return (Twine(toLowercase(Name[3])) + Name.drop_front(4)).str();
649 }
650 
651 size_t SelectorTable::getTotalMemory() const {
652   SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl);
653   return SelTabImpl.Allocator.getTotalMemory();
654 }
655 
656 Selector SelectorTable::getSelector(unsigned nKeys, IdentifierInfo **IIV) {
657   if (nKeys < 2)
658     return Selector(IIV[0], nKeys);
659 
660   SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl);
661 
662   // Unique selector, to guarantee there is one per name.
663   llvm::FoldingSetNodeID ID;
664   MultiKeywordSelector::Profile(ID, IIV, nKeys);
665 
666   void *InsertPos = nullptr;
667   if (MultiKeywordSelector *SI =
668         SelTabImpl.Table.FindNodeOrInsertPos(ID, InsertPos))
669     return Selector(SI);
670 
671   // MultiKeywordSelector objects are not allocated with new because they have a
672   // variable size array (for parameter types) at the end of them.
673   unsigned Size = sizeof(MultiKeywordSelector) + nKeys*sizeof(IdentifierInfo *);
674   MultiKeywordSelector *SI =
675       (MultiKeywordSelector *)SelTabImpl.Allocator.Allocate(
676           Size, alignof(MultiKeywordSelector));
677   new (SI) MultiKeywordSelector(nKeys, IIV);
678   SelTabImpl.Table.InsertNode(SI, InsertPos);
679   return Selector(SI);
680 }
681 
682 SelectorTable::SelectorTable() {
683   Impl = new SelectorTableImpl();
684 }
685 
686 SelectorTable::~SelectorTable() {
687   delete &getSelectorTableImpl(Impl);
688 }
689 
690 const char *clang::getOperatorSpelling(OverloadedOperatorKind Operator) {
691   switch (Operator) {
692   case OO_None:
693   case NUM_OVERLOADED_OPERATORS:
694     return nullptr;
695 
696 #define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
697   case OO_##Name: return Spelling;
698 #include "clang/Basic/OperatorKinds.def"
699   }
700 
701   llvm_unreachable("Invalid OverloadedOperatorKind!");
702 }
703 
704 StringRef clang::getNullabilitySpelling(NullabilityKind kind,
705                                         bool isContextSensitive) {
706   switch (kind) {
707   case NullabilityKind::NonNull:
708     return isContextSensitive ? "nonnull" : "_Nonnull";
709 
710   case NullabilityKind::Nullable:
711     return isContextSensitive ? "nullable" : "_Nullable";
712 
713   case NullabilityKind::Unspecified:
714     return isContextSensitive ? "null_unspecified" : "_Null_unspecified";
715   }
716   llvm_unreachable("Unknown nullability kind.");
717 }
718