IdentifierTable.cpp revision 360784 
1//===- IdentifierTable.cpp - Hash table for identifier lookup -------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This file implements the IdentifierInfo, IdentifierVisitor, and
10// IdentifierTable interfaces.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Basic/IdentifierTable.h"
15#include "clang/Basic/CharInfo.h"
16#include "clang/Basic/LangOptions.h"
17#include "clang/Basic/OperatorKinds.h"
18#include "clang/Basic/Specifiers.h"
19#include "clang/Basic/TokenKinds.h"
20#include "llvm/ADT/DenseMapInfo.h"
21#include "llvm/ADT/FoldingSet.h"
22#include "llvm/ADT/SmallString.h"
23#include "llvm/ADT/StringMap.h"
24#include "llvm/ADT/StringRef.h"
25#include "llvm/Support/Allocator.h"
26#include "llvm/Support/ErrorHandling.h"
27#include "llvm/Support/raw_ostream.h"
28#include <cassert>
29#include <cstdio>
30#include <cstring>
31#include <string>
32
33using namespace clang;
34
35//===----------------------------------------------------------------------===//
36// IdentifierTable Implementation
37//===----------------------------------------------------------------------===//
38
39IdentifierIterator::~IdentifierIterator() = default;
40
41IdentifierInfoLookup::~IdentifierInfoLookup() = default;
42
43namespace {
44
45/// A simple identifier lookup iterator that represents an
46/// empty sequence of identifiers.
47class EmptyLookupIterator : public IdentifierIterator
48{
49public:
50  StringRef Next() override { return StringRef(); }
51};
52
53} // namespace
54
55IdentifierIterator *IdentifierInfoLookup::getIdentifiers() {
56  return new EmptyLookupIterator();
57}
58
59IdentifierTable::IdentifierTable(IdentifierInfoLookup *ExternalLookup)
60    : HashTable(8192), // Start with space for 8K identifiers.
61      ExternalLookup(ExternalLookup) {}
62
63IdentifierTable::IdentifierTable(const LangOptions &LangOpts,
64                                 IdentifierInfoLookup *ExternalLookup)
65    : IdentifierTable(ExternalLookup) {
66  // Populate the identifier table with info about keywords for the current
67  // language.
68  AddKeywords(LangOpts);
69}
70
71//===----------------------------------------------------------------------===//
72// Language Keyword Implementation
73//===----------------------------------------------------------------------===//
74
75// Constants for TokenKinds.def
76namespace {
77
78  enum {
79    KEYC99        = 0x1,
80    KEYCXX        = 0x2,
81    KEYCXX11      = 0x4,
82    KEYGNU        = 0x8,
83    KEYMS         = 0x10,
84    BOOLSUPPORT   = 0x20,
85    KEYALTIVEC    = 0x40,
86    KEYNOCXX      = 0x80,
87    KEYBORLAND    = 0x100,
88    KEYOPENCLC    = 0x200,
89    KEYC11        = 0x400,
90    KEYNOMS18     = 0x800,
91    KEYNOOPENCL   = 0x1000,
92    WCHARSUPPORT  = 0x2000,
93    HALFSUPPORT   = 0x4000,
94    CHAR8SUPPORT  = 0x8000,
95    KEYCONCEPTS   = 0x10000,
96    KEYOBJC       = 0x20000,
97    KEYZVECTOR    = 0x40000,
98    KEYCOROUTINES = 0x80000,
99    KEYMODULES    = 0x100000,
100    KEYCXX2A      = 0x200000,
101    KEYOPENCLCXX  = 0x400000,
102    KEYMSCOMPAT   = 0x800000,
103    KEYALLCXX = KEYCXX | KEYCXX11 | KEYCXX2A,
104    KEYALL = (0xffffff & ~KEYNOMS18 &
105              ~KEYNOOPENCL) // KEYNOMS18 and KEYNOOPENCL are used to exclude.
106  };
107
108  /// How a keyword is treated in the selected standard.
109  enum KeywordStatus {
110    KS_Disabled,    // Disabled
111    KS_Extension,   // Is an extension
112    KS_Enabled,     // Enabled
113    KS_Future       // Is a keyword in future standard
114  };
115
116} // namespace
117
118/// Translates flags as specified in TokenKinds.def into keyword status
119/// in the given language standard.
120static KeywordStatus getKeywordStatus(const LangOptions &LangOpts,
121                                      unsigned Flags) {
122  if (Flags == KEYALL) return KS_Enabled;
123  if (LangOpts.CPlusPlus && (Flags & KEYCXX)) return KS_Enabled;
124  if (LangOpts.CPlusPlus11 && (Flags & KEYCXX11)) return KS_Enabled;
125  if (LangOpts.CPlusPlus2a && (Flags & KEYCXX2A)) return KS_Enabled;
126  if (LangOpts.C99 && (Flags & KEYC99)) return KS_Enabled;
127  if (LangOpts.GNUKeywords && (Flags & KEYGNU)) return KS_Extension;
128  if (LangOpts.MicrosoftExt && (Flags & KEYMS)) return KS_Extension;
129  if (LangOpts.MSVCCompat && (Flags & KEYMSCOMPAT)) return KS_Enabled;
130  if (LangOpts.Borland && (Flags & KEYBORLAND)) return KS_Extension;
131  if (LangOpts.Bool && (Flags & BOOLSUPPORT)) return KS_Enabled;
132  if (LangOpts.Half && (Flags & HALFSUPPORT)) return KS_Enabled;
133  if (LangOpts.WChar && (Flags & WCHARSUPPORT)) return KS_Enabled;
134  if (LangOpts.Char8 && (Flags & CHAR8SUPPORT)) return KS_Enabled;
135  if (LangOpts.AltiVec && (Flags & KEYALTIVEC)) return KS_Enabled;
136  if (LangOpts.ZVector && (Flags & KEYZVECTOR)) return KS_Enabled;
137  if (LangOpts.OpenCL && !LangOpts.OpenCLCPlusPlus && (Flags & KEYOPENCLC))
138    return KS_Enabled;
139  if (LangOpts.OpenCLCPlusPlus && (Flags & KEYOPENCLCXX)) return KS_Enabled;
140  if (!LangOpts.CPlusPlus && (Flags & KEYNOCXX)) return KS_Enabled;
141  if (LangOpts.C11 && (Flags & KEYC11)) return KS_Enabled;
142  // We treat bridge casts as objective-C keywords so we can warn on them
143  // in non-arc mode.
144  if (LangOpts.ObjC && (Flags & KEYOBJC)) return KS_Enabled;
145  if (LangOpts.CPlusPlus2a && (Flags & KEYCONCEPTS)) return KS_Enabled;
146  if (LangOpts.Coroutines && (Flags & KEYCOROUTINES)) return KS_Enabled;
147  if (LangOpts.ModulesTS && (Flags & KEYMODULES)) return KS_Enabled;
148  if (LangOpts.CPlusPlus && (Flags & KEYALLCXX)) return KS_Future;
149  return KS_Disabled;
150}
151
152/// AddKeyword - This method is used to associate a token ID with specific
153/// identifiers because they are language keywords.  This causes the lexer to
154/// automatically map matching identifiers to specialized token codes.
155static void AddKeyword(StringRef Keyword,
156                       tok::TokenKind TokenCode, unsigned Flags,
157                       const LangOptions &LangOpts, IdentifierTable &Table) {
158  KeywordStatus AddResult = getKeywordStatus(LangOpts, Flags);
159
160  // Don't add this keyword under MSVCCompat.
161  if (LangOpts.MSVCCompat && (Flags & KEYNOMS18) &&
162      !LangOpts.isCompatibleWithMSVC(LangOptions::MSVC2015))
163    return;
164
165  // Don't add this keyword under OpenCL.
166  if (LangOpts.OpenCL && (Flags & KEYNOOPENCL))
167    return;
168
169  // Don't add this keyword if disabled in this language.
170  if (AddResult == KS_Disabled) return;
171
172  IdentifierInfo &Info =
173      Table.get(Keyword, AddResult == KS_Future ? tok::identifier : TokenCode);
174  Info.setIsExtensionToken(AddResult == KS_Extension);
175  Info.setIsFutureCompatKeyword(AddResult == KS_Future);
176}
177
178/// AddCXXOperatorKeyword - Register a C++ operator keyword alternative
179/// representations.
180static void AddCXXOperatorKeyword(StringRef Keyword,
181                                  tok::TokenKind TokenCode,
182                                  IdentifierTable &Table) {
183  IdentifierInfo &Info = Table.get(Keyword, TokenCode);
184  Info.setIsCPlusPlusOperatorKeyword();
185}
186
187/// AddObjCKeyword - Register an Objective-C \@keyword like "class" "selector"
188/// or "property".
189static void AddObjCKeyword(StringRef Name,
190                           tok::ObjCKeywordKind ObjCID,
191                           IdentifierTable &Table) {
192  Table.get(Name).setObjCKeywordID(ObjCID);
193}
194
195/// AddKeywords - Add all keywords to the symbol table.
196///
197void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {
198  // Add keywords and tokens for the current language.
199#define KEYWORD(NAME, FLAGS) \
200  AddKeyword(StringRef(#NAME), tok::kw_ ## NAME,  \
201             FLAGS, LangOpts, *this);
202#define ALIAS(NAME, TOK, FLAGS) \
203  AddKeyword(StringRef(NAME), tok::kw_ ## TOK,  \
204             FLAGS, LangOpts, *this);
205#define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \
206  if (LangOpts.CXXOperatorNames)          \
207    AddCXXOperatorKeyword(StringRef(#NAME), tok::ALIAS, *this);
208#define OBJC_AT_KEYWORD(NAME)  \
209  if (LangOpts.ObjC)           \
210    AddObjCKeyword(StringRef(#NAME), tok::objc_##NAME, *this);
211#define TESTING_KEYWORD(NAME, FLAGS)
212#include "clang/Basic/TokenKinds.def"
213
214  if (LangOpts.ParseUnknownAnytype)
215    AddKeyword("__unknown_anytype", tok::kw___unknown_anytype, KEYALL,
216               LangOpts, *this);
217
218  if (LangOpts.DeclSpecKeyword)
219    AddKeyword("__declspec", tok::kw___declspec, KEYALL, LangOpts, *this);
220
221  // Add the 'import' contextual keyword.
222  get("import").setModulesImport(true);
223}
224
225/// Checks if the specified token kind represents a keyword in the
226/// specified language.
227/// \returns Status of the keyword in the language.
228static KeywordStatus getTokenKwStatus(const LangOptions &LangOpts,
229                                      tok::TokenKind K) {
230  switch (K) {
231#define KEYWORD(NAME, FLAGS) \
232  case tok::kw_##NAME: return getKeywordStatus(LangOpts, FLAGS);
233#include "clang/Basic/TokenKinds.def"
234  default: return KS_Disabled;
235  }
236}
237
238/// Returns true if the identifier represents a keyword in the
239/// specified language.
240bool IdentifierInfo::isKeyword(const LangOptions &LangOpts) const {
241  switch (getTokenKwStatus(LangOpts, getTokenID())) {
242  case KS_Enabled:
243  case KS_Extension:
244    return true;
245  default:
246    return false;
247  }
248}
249
250/// Returns true if the identifier represents a C++ keyword in the
251/// specified language.
252bool IdentifierInfo::isCPlusPlusKeyword(const LangOptions &LangOpts) const {
253  if (!LangOpts.CPlusPlus || !isKeyword(LangOpts))
254    return false;
255  // This is a C++ keyword if this identifier is not a keyword when checked
256  // using LangOptions without C++ support.
257  LangOptions LangOptsNoCPP = LangOpts;
258  LangOptsNoCPP.CPlusPlus = false;
259  LangOptsNoCPP.CPlusPlus11 = false;
260  LangOptsNoCPP.CPlusPlus2a = false;
261  return !isKeyword(LangOptsNoCPP);
262}
263
264tok::PPKeywordKind IdentifierInfo::getPPKeywordID() const {
265  // We use a perfect hash function here involving the length of the keyword,
266  // the first and third character.  For preprocessor ID's there are no
267  // collisions (if there were, the switch below would complain about duplicate
268  // case values).  Note that this depends on 'if' being null terminated.
269
270#define HASH(LEN, FIRST, THIRD) \
271  (LEN << 5) + (((FIRST-'a') + (THIRD-'a')) & 31)
272#define CASE(LEN, FIRST, THIRD, NAME) \
273  case HASH(LEN, FIRST, THIRD): \
274    return memcmp(Name, #NAME, LEN) ? tok::pp_not_keyword : tok::pp_ ## NAME
275
276  unsigned Len = getLength();
277  if (Len < 2) return tok::pp_not_keyword;
278  const char *Name = getNameStart();
279  switch (HASH(Len, Name[0], Name[2])) {
280  default: return tok::pp_not_keyword;
281  CASE( 2, 'i', '\0', if);
282  CASE( 4, 'e', 'i', elif);
283  CASE( 4, 'e', 's', else);
284  CASE( 4, 'l', 'n', line);
285  CASE( 4, 's', 'c', sccs);
286  CASE( 5, 'e', 'd', endif);
287  CASE( 5, 'e', 'r', error);
288  CASE( 5, 'i', 'e', ident);
289  CASE( 5, 'i', 'd', ifdef);
290  CASE( 5, 'u', 'd', undef);
291
292  CASE( 6, 'a', 's', assert);
293  CASE( 6, 'd', 'f', define);
294  CASE( 6, 'i', 'n', ifndef);
295  CASE( 6, 'i', 'p', import);
296  CASE( 6, 'p', 'a', pragma);
297
298  CASE( 7, 'd', 'f', defined);
299  CASE( 7, 'i', 'c', include);
300  CASE( 7, 'w', 'r', warning);
301
302  CASE( 8, 'u', 'a', unassert);
303  CASE(12, 'i', 'c', include_next);
304
305  CASE(14, '_', 'p', __public_macro);
306
307  CASE(15, '_', 'p', __private_macro);
308
309  CASE(16, '_', 'i', __include_macros);
310#undef CASE
311#undef HASH
312  }
313}
314
315//===----------------------------------------------------------------------===//
316// Stats Implementation
317//===----------------------------------------------------------------------===//
318
319/// PrintStats - Print statistics about how well the identifier table is doing
320/// at hashing identifiers.
321void IdentifierTable::PrintStats() const {
322  unsigned NumBuckets = HashTable.getNumBuckets();
323  unsigned NumIdentifiers = HashTable.getNumItems();
324  unsigned NumEmptyBuckets = NumBuckets-NumIdentifiers;
325  unsigned AverageIdentifierSize = 0;
326  unsigned MaxIdentifierLength = 0;
327
328  // TODO: Figure out maximum times an identifier had to probe for -stats.
329  for (llvm::StringMap<IdentifierInfo*, llvm::BumpPtrAllocator>::const_iterator
330       I = HashTable.begin(), E = HashTable.end(); I != E; ++I) {
331    unsigned IdLen = I->getKeyLength();
332    AverageIdentifierSize += IdLen;
333    if (MaxIdentifierLength < IdLen)
334      MaxIdentifierLength = IdLen;
335  }
336
337  fprintf(stderr, "\n*** Identifier Table Stats:\n");
338  fprintf(stderr, "# Identifiers:   %d\n", NumIdentifiers);
339  fprintf(stderr, "# Empty Buckets: %d\n", NumEmptyBuckets);
340  fprintf(stderr, "Hash density (#identifiers per bucket): %f\n",
341          NumIdentifiers/(double)NumBuckets);
342  fprintf(stderr, "Ave identifier length: %f\n",
343          (AverageIdentifierSize/(double)NumIdentifiers));
344  fprintf(stderr, "Max identifier length: %d\n", MaxIdentifierLength);
345
346  // Compute statistics about the memory allocated for identifiers.
347  HashTable.getAllocator().PrintStats();
348}
349
350//===----------------------------------------------------------------------===//
351// SelectorTable Implementation
352//===----------------------------------------------------------------------===//
353
354unsigned llvm::DenseMapInfo<clang::Selector>::getHashValue(clang::Selector S) {
355  return DenseMapInfo<void*>::getHashValue(S.getAsOpaquePtr());
356}
357
358namespace clang {
359
360/// One of these variable length records is kept for each
361/// selector containing more than one keyword. We use a folding set
362/// to unique aggregate names (keyword selectors in ObjC parlance). Access to
363/// this class is provided strictly through Selector.
364class alignas(IdentifierInfoAlignment) MultiKeywordSelector
365    : public detail::DeclarationNameExtra,
366      public llvm::FoldingSetNode {
367  MultiKeywordSelector(unsigned nKeys) : DeclarationNameExtra(nKeys) {}
368
369public:
370  // Constructor for keyword selectors.
371  MultiKeywordSelector(unsigned nKeys, IdentifierInfo **IIV)
372      : DeclarationNameExtra(nKeys) {
373    assert((nKeys > 1) && "not a multi-keyword selector");
374
375    // Fill in the trailing keyword array.
376    IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(this + 1);
377    for (unsigned i = 0; i != nKeys; ++i)
378      KeyInfo[i] = IIV[i];
379  }
380
381  // getName - Derive the full selector name and return it.
382  std::string getName() const;
383
384  using DeclarationNameExtra::getNumArgs;
385
386  using keyword_iterator = IdentifierInfo *const *;
387
388  keyword_iterator keyword_begin() const {
389    return reinterpret_cast<keyword_iterator>(this + 1);
390  }
391
392  keyword_iterator keyword_end() const {
393    return keyword_begin() + getNumArgs();
394  }
395
396  IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const {
397    assert(i < getNumArgs() && "getIdentifierInfoForSlot(): illegal index");
398    return keyword_begin()[i];
399  }
400
401  static void Profile(llvm::FoldingSetNodeID &ID, keyword_iterator ArgTys,
402                      unsigned NumArgs) {
403    ID.AddInteger(NumArgs);
404    for (unsigned i = 0; i != NumArgs; ++i)
405      ID.AddPointer(ArgTys[i]);
406  }
407
408  void Profile(llvm::FoldingSetNodeID &ID) {
409    Profile(ID, keyword_begin(), getNumArgs());
410  }
411};
412
413} // namespace clang.
414
415bool Selector::isKeywordSelector(ArrayRef<StringRef> Names) const {
416  assert(!Names.empty() && "must have >= 1 selector slots");
417  if (getNumArgs() != Names.size())
418    return false;
419  for (unsigned I = 0, E = Names.size(); I != E; ++I) {
420    if (getNameForSlot(I) != Names[I])
421      return false;
422  }
423  return true;
424}
425
426bool Selector::isUnarySelector(StringRef Name) const {
427  return isUnarySelector() && getNameForSlot(0) == Name;
428}
429
430unsigned Selector::getNumArgs() const {
431  unsigned IIF = getIdentifierInfoFlag();
432  if (IIF <= ZeroArg)
433    return 0;
434  if (IIF == OneArg)
435    return 1;
436  // We point to a MultiKeywordSelector.
437  MultiKeywordSelector *SI = getMultiKeywordSelector();
438  return SI->getNumArgs();
439}
440
441IdentifierInfo *Selector::getIdentifierInfoForSlot(unsigned argIndex) const {
442  if (getIdentifierInfoFlag() < MultiArg) {
443    assert(argIndex == 0 && "illegal keyword index");
444    return getAsIdentifierInfo();
445  }
446
447  // We point to a MultiKeywordSelector.
448  MultiKeywordSelector *SI = getMultiKeywordSelector();
449  return SI->getIdentifierInfoForSlot(argIndex);
450}
451
452StringRef Selector::getNameForSlot(unsigned int argIndex) const {
453  IdentifierInfo *II = getIdentifierInfoForSlot(argIndex);
454  return II ? II->getName() : StringRef();
455}
456
457std::string MultiKeywordSelector::getName() const {
458  SmallString<256> Str;
459  llvm::raw_svector_ostream OS(Str);
460  for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) {
461    if (*I)
462      OS << (*I)->getName();
463    OS << ':';
464  }
465
466  return OS.str();
467}
468
469std::string Selector::getAsString() const {
470  if (InfoPtr == 0)
471    return "<null selector>";
472
473  if (getIdentifierInfoFlag() < MultiArg) {
474    IdentifierInfo *II = getAsIdentifierInfo();
475
476    if (getNumArgs() == 0) {
477      assert(II && "If the number of arguments is 0 then II is guaranteed to "
478                   "not be null.");
479      return II->getName();
480    }
481
482    if (!II)
483      return ":";
484
485    return II->getName().str() + ":";
486  }
487
488  // We have a multiple keyword selector.
489  return getMultiKeywordSelector()->getName();
490}
491
492void Selector::print(llvm::raw_ostream &OS) const {
493  OS << getAsString();
494}
495
496LLVM_DUMP_METHOD void Selector::dump() const { print(llvm::errs()); }
497
498/// Interpreting the given string using the normal CamelCase
499/// conventions, determine whether the given string starts with the
500/// given "word", which is assumed to end in a lowercase letter.
501static bool startsWithWord(StringRef name, StringRef word) {
502  if (name.size() < word.size()) return false;
503  return ((name.size() == word.size() || !isLowercase(name[word.size()])) &&
504          name.startswith(word));
505}
506
507ObjCMethodFamily Selector::getMethodFamilyImpl(Selector sel) {
508  IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
509  if (!first) return OMF_None;
510
511  StringRef name = first->getName();
512  if (sel.isUnarySelector()) {
513    if (name == "autorelease") return OMF_autorelease;
514    if (name == "dealloc") return OMF_dealloc;
515    if (name == "finalize") return OMF_finalize;
516    if (name == "release") return OMF_release;
517    if (name == "retain") return OMF_retain;
518    if (name == "retainCount") return OMF_retainCount;
519    if (name == "self") return OMF_self;
520    if (name == "initialize") return OMF_initialize;
521  }
522
523  if (name == "performSelector" || name == "performSelectorInBackground" ||
524      name == "performSelectorOnMainThread")
525    return OMF_performSelector;
526
527  // The other method families may begin with a prefix of underscores.
528  while (!name.empty() && name.front() == '_')
529    name = name.substr(1);
530
531  if (name.empty()) return OMF_None;
532  switch (name.front()) {
533  case 'a':
534    if (startsWithWord(name, "alloc")) return OMF_alloc;
535    break;
536  case 'c':
537    if (startsWithWord(name, "copy")) return OMF_copy;
538    break;
539  case 'i':
540    if (startsWithWord(name, "init")) return OMF_init;
541    break;
542  case 'm':
543    if (startsWithWord(name, "mutableCopy")) return OMF_mutableCopy;
544    break;
545  case 'n':
546    if (startsWithWord(name, "new")) return OMF_new;
547    break;
548  default:
549    break;
550  }
551
552  return OMF_None;
553}
554
555ObjCInstanceTypeFamily Selector::getInstTypeMethodFamily(Selector sel) {
556  IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
557  if (!first) return OIT_None;
558
559  StringRef name = first->getName();
560
561  if (name.empty()) return OIT_None;
562  switch (name.front()) {
563    case 'a':
564      if (startsWithWord(name, "array")) return OIT_Array;
565      break;
566    case 'd':
567      if (startsWithWord(name, "default")) return OIT_ReturnsSelf;
568      if (startsWithWord(name, "dictionary")) return OIT_Dictionary;
569      break;
570    case 's':
571      if (startsWithWord(name, "shared")) return OIT_ReturnsSelf;
572      if (startsWithWord(name, "standard")) return OIT_Singleton;
573      break;
574    case 'i':
575      if (startsWithWord(name, "init")) return OIT_Init;
576      break;
577    default:
578      break;
579  }
580  return OIT_None;
581}
582
583ObjCStringFormatFamily Selector::getStringFormatFamilyImpl(Selector sel) {
584  IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);
585  if (!first) return SFF_None;
586
587  StringRef name = first->getName();
588
589  switch (name.front()) {
590    case 'a':
591      if (name == "appendFormat") return SFF_NSString;
592      break;
593
594    case 'i':
595      if (name == "initWithFormat") return SFF_NSString;
596      break;
597
598    case 'l':
599      if (name == "localizedStringWithFormat") return SFF_NSString;
600      break;
601
602    case 's':
603      if (name == "stringByAppendingFormat" ||
604          name == "stringWithFormat") return SFF_NSString;
605      break;
606  }
607  return SFF_None;
608}
609
610namespace {
611
612struct SelectorTableImpl {
613  llvm::FoldingSet<MultiKeywordSelector> Table;
614  llvm::BumpPtrAllocator Allocator;
615};
616
617} // namespace
618
619static SelectorTableImpl &getSelectorTableImpl(void *P) {
620  return *static_cast<SelectorTableImpl*>(P);
621}
622
623SmallString<64>
624SelectorTable::constructSetterName(StringRef Name) {
625  SmallString<64> SetterName("set");
626  SetterName += Name;
627  SetterName[3] = toUppercase(SetterName[3]);
628  return SetterName;
629}
630
631Selector
632SelectorTable::constructSetterSelector(IdentifierTable &Idents,
633                                       SelectorTable &SelTable,
634                                       const IdentifierInfo *Name) {
635  IdentifierInfo *SetterName =
636    &Idents.get(constructSetterName(Name->getName()));
637  return SelTable.getUnarySelector(SetterName);
638}
639
640std::string SelectorTable::getPropertyNameFromSetterSelector(Selector Sel) {
641  StringRef Name = Sel.getNameForSlot(0);
642  assert(Name.startswith("set") && "invalid setter name");
643  return (Twine(toLowercase(Name[3])) + Name.drop_front(4)).str();
644}
645
646size_t SelectorTable::getTotalMemory() const {
647  SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl);
648  return SelTabImpl.Allocator.getTotalMemory();
649}
650
651Selector SelectorTable::getSelector(unsigned nKeys, IdentifierInfo **IIV) {
652  if (nKeys < 2)
653    return Selector(IIV[0], nKeys);
654
655  SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl);
656
657  // Unique selector, to guarantee there is one per name.
658  llvm::FoldingSetNodeID ID;
659  MultiKeywordSelector::Profile(ID, IIV, nKeys);
660
661  void *InsertPos = nullptr;
662  if (MultiKeywordSelector *SI =
663        SelTabImpl.Table.FindNodeOrInsertPos(ID, InsertPos))
664    return Selector(SI);
665
666  // MultiKeywordSelector objects are not allocated with new because they have a
667  // variable size array (for parameter types) at the end of them.
668  unsigned Size = sizeof(MultiKeywordSelector) + nKeys*sizeof(IdentifierInfo *);
669  MultiKeywordSelector *SI =
670      (MultiKeywordSelector *)SelTabImpl.Allocator.Allocate(
671          Size, alignof(MultiKeywordSelector));
672  new (SI) MultiKeywordSelector(nKeys, IIV);
673  SelTabImpl.Table.InsertNode(SI, InsertPos);
674  return Selector(SI);
675}
676
677SelectorTable::SelectorTable() {
678  Impl = new SelectorTableImpl();
679}
680
681SelectorTable::~SelectorTable() {
682  delete &getSelectorTableImpl(Impl);
683}
684
685const char *clang::getOperatorSpelling(OverloadedOperatorKind Operator) {
686  switch (Operator) {
687  case OO_None:
688  case NUM_OVERLOADED_OPERATORS:
689    return nullptr;
690
691#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \
692  case OO_##Name: return Spelling;
693#include "clang/Basic/OperatorKinds.def"
694  }
695
696  llvm_unreachable("Invalid OverloadedOperatorKind!");
697}
698
699StringRef clang::getNullabilitySpelling(NullabilityKind kind,
700                                        bool isContextSensitive) {
701  switch (kind) {
702  case NullabilityKind::NonNull:
703    return isContextSensitive ? "nonnull" : "_Nonnull";
704
705  case NullabilityKind::Nullable:
706    return isContextSensitive ? "nullable" : "_Nullable";
707
708  case NullabilityKind::Unspecified:
709    return isContextSensitive ? "null_unspecified" : "_Null_unspecified";
710  }
711  llvm_unreachable("Unknown nullability kind.");
712}
713