//===- IdentifierTable.cpp - Hash table for identifier lookup -------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// This file implements the IdentifierInfo, IdentifierVisitor, and

// IdentifierTable interfaces.

//

//===----------------------------------------------------------------------===//

#include "clang/Basic/IdentifierTable.h"

#include "clang/Basic/CharInfo.h"

#include "clang/Basic/DiagnosticLex.h"

#include "clang/Basic/LangOptions.h"

#include "clang/Basic/OperatorKinds.h"

#include "clang/Basic/Specifiers.h"

#include "clang/Basic/TargetBuiltins.h"

#include "clang/Basic/TokenKinds.h"

#include "llvm/ADT/DenseMapInfo.h"

#include "llvm/ADT/FoldingSet.h"

#include "llvm/ADT/SmallString.h"

#include "llvm/ADT/StringMap.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Support/Allocator.h"

#include "llvm/Support/raw_ostream.h"

#include <cassert>

#include <cstdio>

#include <cstring>

#include <string>

using namespace clang;

// A check to make sure the ObjCOrBuiltinID has sufficient room to store the

// largest possible target/aux-target combination. If we exceed this, we likely

// need to just change the ObjCOrBuiltinIDBits value in IdentifierTable.h.

static_assert(2 * LargestBuiltinID < (2 << (ObjCOrBuiltinIDBits - 1)),

              "Insufficient ObjCOrBuiltinID Bits");

//===----------------------------------------------------------------------===//

// IdentifierTable Implementation

//===----------------------------------------------------------------------===//

IdentifierIterator::~IdentifierIterator() = default;

IdentifierInfoLookup::~IdentifierInfoLookup() = default;

namespace {

/// A simple identifier lookup iterator that represents an

/// empty sequence of identifiers.

class EmptyLookupIterator : public IdentifierIterator {

public:

  StringRef Next() override { return StringRef(); }

};

} // namespace

IdentifierIterator *IdentifierInfoLookup::getIdentifiers() {

  return new EmptyLookupIterator();

}

IdentifierTable::IdentifierTable(IdentifierInfoLookup *ExternalLookup)

    : HashTable(8192), // Start with space for 8K identifiers.

      ExternalLookup(ExternalLookup) {}

IdentifierTable::IdentifierTable(const LangOptions &LangOpts,

                                 IdentifierInfoLookup *ExternalLookup)

    : IdentifierTable(ExternalLookup) {

  // Populate the identifier table with info about keywords for the current

  // language.

  AddKeywords(LangOpts);

}

//===----------------------------------------------------------------------===//

// Language Keyword Implementation

//===----------------------------------------------------------------------===//

// Constants for TokenKinds.def

namespace {

  enum TokenKey : unsigned {

    KEYC99        = 0x1,

    KEYCXX        = 0x2,

    KEYCXX11      = 0x4,

    KEYGNU        = 0x8,

    KEYMS         = 0x10,

    BOOLSUPPORT   = 0x20,

    KEYALTIVEC    = 0x40,

    KEYNOCXX      = 0x80,

    KEYBORLAND    = 0x100,

    KEYOPENCLC    = 0x200,

    KEYC23        = 0x400,

    KEYNOMS18     = 0x800,

    KEYNOOPENCL   = 0x1000,

    WCHARSUPPORT  = 0x2000,

    HALFSUPPORT   = 0x4000,

    CHAR8SUPPORT  = 0x8000,

    KEYOBJC       = 0x10000,

    KEYZVECTOR    = 0x20000,

    KEYCOROUTINES = 0x40000,

    KEYMODULES    = 0x80000,

    KEYCXX20      = 0x100000,

    KEYOPENCLCXX  = 0x200000,

    KEYMSCOMPAT   = 0x400000,

    KEYSYCL       = 0x800000,

    KEYCUDA       = 0x1000000,

    KEYHLSL       = 0x2000000,

    KEYFIXEDPOINT = 0x4000000,

    KEYMAX        = KEYFIXEDPOINT, // The maximum key

    KEYALLCXX = KEYCXX | KEYCXX11 | KEYCXX20,

    KEYALL = (KEYMAX | (KEYMAX-1)) & ~KEYNOMS18 &

             ~KEYNOOPENCL // KEYNOMS18 and KEYNOOPENCL are used to exclude.

  };

  /// How a keyword is treated in the selected standard. This enum is ordered

  /// intentionally so that the value that 'wins' is the most 'permissive'.

  enum KeywordStatus {

    KS_Unknown,     // Not yet calculated. Used when figuring out the status.

    KS_Disabled,    // Disabled

    KS_Future,      // Is a keyword in future standard

    KS_Extension,   // Is an extension

    KS_Enabled,     // Enabled

  };

} // namespace

// This works on a single TokenKey flag and checks the LangOpts to get the

// KeywordStatus based exclusively on this flag, so that it can be merged in

// getKeywordStatus. Most should be enabled/disabled, but some might imply

// 'future' versions, or extensions. Returns 'unknown' unless this is KNOWN to

// be disabled, and the calling function makes it 'disabled' if no other flag

// changes it. This is necessary for the KEYNOCXX and KEYNOOPENCL flags.

static KeywordStatus getKeywordStatusHelper(const LangOptions &LangOpts,

                                            TokenKey Flag) {

  // Flag is a single bit version of TokenKey (that is, not

  // KEYALL/KEYALLCXX/etc), so we can check with == throughout this function.

  assert((Flag & ~(Flag - 1)) == Flag && "Multiple bits set?");

  switch (Flag) {

  case KEYC99:

    if (LangOpts.C99)

      return KS_Enabled;

    return !LangOpts.CPlusPlus ? KS_Future : KS_Unknown;

  case KEYC23:

    if (LangOpts.C23)

      return KS_Enabled;

    return !LangOpts.CPlusPlus ? KS_Future : KS_Unknown;

  case KEYCXX:

    return LangOpts.CPlusPlus ? KS_Enabled : KS_Unknown;

  case KEYCXX11:

    if (LangOpts.CPlusPlus11)

      return KS_Enabled;

    return LangOpts.CPlusPlus ? KS_Future : KS_Unknown;

  case KEYCXX20:

    if (LangOpts.CPlusPlus20)

      return KS_Enabled;

    return LangOpts.CPlusPlus ? KS_Future : KS_Unknown;

  case KEYGNU:

    return LangOpts.GNUKeywords ? KS_Extension : KS_Unknown;

  case KEYMS:

    return LangOpts.MicrosoftExt ? KS_Extension : KS_Unknown;

  case BOOLSUPPORT:

    if (LangOpts.Bool)      return KS_Enabled;

    return !LangOpts.CPlusPlus ? KS_Future : KS_Unknown;

  case KEYALTIVEC:

    return LangOpts.AltiVec ? KS_Enabled : KS_Unknown;

  case KEYBORLAND:

    return LangOpts.Borland ? KS_Extension : KS_Unknown;

  case KEYOPENCLC:

    return LangOpts.OpenCL && !LangOpts.OpenCLCPlusPlus ? KS_Enabled

                                                        : KS_Unknown;

  case WCHARSUPPORT:

    return LangOpts.WChar ? KS_Enabled : KS_Unknown;

  case HALFSUPPORT:

    return LangOpts.Half ? KS_Enabled : KS_Unknown;

  case CHAR8SUPPORT:

    if (LangOpts.Char8) return KS_Enabled;

    if (LangOpts.CPlusPlus20) return KS_Unknown;

    if (LangOpts.CPlusPlus) return KS_Future;

    return KS_Unknown;

  case KEYOBJC:

    // We treat bridge casts as objective-C keywords so we can warn on them

    // in non-arc mode.

    return LangOpts.ObjC ? KS_Enabled : KS_Unknown;

  case KEYZVECTOR:

    return LangOpts.ZVector ? KS_Enabled : KS_Unknown;

  case KEYCOROUTINES:

    return LangOpts.Coroutines ? KS_Enabled : KS_Unknown;

  case KEYMODULES:

    return KS_Unknown;

  case KEYOPENCLCXX:

    return LangOpts.OpenCLCPlusPlus ? KS_Enabled : KS_Unknown;

  case KEYMSCOMPAT:

    return LangOpts.MSVCCompat ? KS_Enabled : KS_Unknown;

  case KEYSYCL:

    return LangOpts.isSYCL() ? KS_Enabled : KS_Unknown;

  case KEYCUDA:

    return LangOpts.CUDA ? KS_Enabled : KS_Unknown;

  case KEYHLSL:

    return LangOpts.HLSL ? KS_Enabled : KS_Unknown;

  case KEYNOCXX:

    // This is enabled in all non-C++ modes, but might be enabled for other

    // reasons as well.

    return LangOpts.CPlusPlus ? KS_Unknown : KS_Enabled;

  case KEYNOOPENCL:

    // The disable behavior for this is handled in getKeywordStatus.

    return KS_Unknown;

  case KEYNOMS18:

    // The disable behavior for this is handled in getKeywordStatus.

    return KS_Unknown;

  case KEYFIXEDPOINT:

    return LangOpts.FixedPoint ? KS_Enabled : KS_Disabled;

  default:

    llvm_unreachable("Unknown KeywordStatus flag");

  }

}

/// Translates flags as specified in TokenKinds.def into keyword status

/// in the given language standard.

static KeywordStatus getKeywordStatus(const LangOptions &LangOpts,

                                      unsigned Flags) {

  // KEYALL means always enabled, so special case this one.

  if (Flags == KEYALL) return KS_Enabled;

  // These are tests that need to 'always win', as they are special in that they

  // disable based on certain conditions.

  if (LangOpts.OpenCL && (Flags & KEYNOOPENCL)) return KS_Disabled;

  if (LangOpts.MSVCCompat && (Flags & KEYNOMS18) &&

      !LangOpts.isCompatibleWithMSVC(LangOptions::MSVC2015))

    return KS_Disabled;

  KeywordStatus CurStatus = KS_Unknown;

  while (Flags != 0) {

    unsigned CurFlag = Flags & ~(Flags - 1);

    Flags = Flags & ~CurFlag;

    CurStatus = std::max(

        CurStatus,

        getKeywordStatusHelper(LangOpts, static_cast<TokenKey>(CurFlag)));

  }

  if (CurStatus == KS_Unknown)

    return KS_Disabled;

  return CurStatus;

}

/// AddKeyword - This method is used to associate a token ID with specific

/// identifiers because they are language keywords.  This causes the lexer to

/// automatically map matching identifiers to specialized token codes.

static void AddKeyword(StringRef Keyword,

                       tok::TokenKind TokenCode, unsigned Flags,

                       const LangOptions &LangOpts, IdentifierTable &Table) {

  KeywordStatus AddResult = getKeywordStatus(LangOpts, Flags);

  // Don't add this keyword if disabled in this language.

  if (AddResult == KS_Disabled) return;

  IdentifierInfo &Info =

      Table.get(Keyword, AddResult == KS_Future ? tok::identifier : TokenCode);

  Info.setIsExtensionToken(AddResult == KS_Extension);

  Info.setIsFutureCompatKeyword(AddResult == KS_Future);

}

/// AddCXXOperatorKeyword - Register a C++ operator keyword alternative

/// representations.

static void AddCXXOperatorKeyword(StringRef Keyword,

                                  tok::TokenKind TokenCode,

                                  IdentifierTable &Table) {

  IdentifierInfo &Info = Table.get(Keyword, TokenCode);

  Info.setIsCPlusPlusOperatorKeyword();

}

/// AddObjCKeyword - Register an Objective-C \@keyword like "class" "selector"

/// or "property".

static void AddObjCKeyword(StringRef Name,

                           tok::ObjCKeywordKind ObjCID,

                           IdentifierTable &Table) {

  Table.get(Name).setObjCKeywordID(ObjCID);

}

static void AddInterestingIdentifier(StringRef Name,

                                     tok::InterestingIdentifierKind BTID,

                                     IdentifierTable &Table) {

  // Don't add 'not_interesting' identifier.

  if (BTID != tok::not_interesting) {

    IdentifierInfo &Info = Table.get(Name, tok::identifier);

    Info.setInterestingIdentifierID(BTID);

  }

}

/// AddKeywords - Add all keywords to the symbol table.

///

void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {

  // Add keywords and tokens for the current language.

#define KEYWORD(NAME, FLAGS) \

  AddKeyword(StringRef(#NAME), tok::kw_ ## NAME,  \

             FLAGS, LangOpts, *this);

#define ALIAS(NAME, TOK, FLAGS) \

  AddKeyword(StringRef(NAME), tok::kw_ ## TOK,  \

             FLAGS, LangOpts, *this);

#define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \

  if (LangOpts.CXXOperatorNames)          \

    AddCXXOperatorKeyword(StringRef(#NAME), tok::ALIAS, *this);

#define OBJC_AT_KEYWORD(NAME)  \

  if (LangOpts.ObjC)           \

    AddObjCKeyword(StringRef(#NAME), tok::objc_##NAME, *this);

#define INTERESTING_IDENTIFIER(NAME)                                           \

  AddInterestingIdentifier(StringRef(#NAME), tok::NAME, *this);

#define TESTING_KEYWORD(NAME, FLAGS)

#include "clang/Basic/TokenKinds.def"

  if (LangOpts.ParseUnknownAnytype)

    AddKeyword("__unknown_anytype", tok::kw___unknown_anytype, KEYALL,

               LangOpts, *this);

  if (LangOpts.DeclSpecKeyword)

    AddKeyword("__declspec", tok::kw___declspec, KEYALL, LangOpts, *this);

  if (LangOpts.IEEE128)

    AddKeyword("__ieee128", tok::kw___float128, KEYALL, LangOpts, *this);

  // Add the 'import' contextual keyword.

  get("import").setModulesImport(true);

}

/// Checks if the specified token kind represents a keyword in the

/// specified language.

/// \returns Status of the keyword in the language.

static KeywordStatus getTokenKwStatus(const LangOptions &LangOpts,

                                      tok::TokenKind K) {

  switch (K) {

#define KEYWORD(NAME, FLAGS) \

  case tok::kw_##NAME: return getKeywordStatus(LangOpts, FLAGS);

#include "clang/Basic/TokenKinds.def"

  default: return KS_Disabled;

  }

}

/// Returns true if the identifier represents a keyword in the

/// specified language.

bool IdentifierInfo::isKeyword(const LangOptions &LangOpts) const {

  switch (getTokenKwStatus(LangOpts, getTokenID())) {

  case KS_Enabled:

  case KS_Extension:

    return true;

  default:

    return false;

  }

}

/// Returns true if the identifier represents a C++ keyword in the

/// specified language.

bool IdentifierInfo::isCPlusPlusKeyword(const LangOptions &LangOpts) const {

  if (!LangOpts.CPlusPlus || !isKeyword(LangOpts))

    return false;

  // This is a C++ keyword if this identifier is not a keyword when checked

  // using LangOptions without C++ support.

  LangOptions LangOptsNoCPP = LangOpts;

  LangOptsNoCPP.CPlusPlus = false;

  LangOptsNoCPP.CPlusPlus11 = false;

  LangOptsNoCPP.CPlusPlus20 = false;

  return !isKeyword(LangOptsNoCPP);

}

ReservedIdentifierStatus

IdentifierInfo::isReserved(const LangOptions &LangOpts) const {

  StringRef Name = getName();

  // '_' is a reserved identifier, but its use is so common (e.g. to store

  // ignored values) that we don't warn on it.

  if (Name.size() <= 1)

    return ReservedIdentifierStatus::NotReserved;

  // [lex.name] p3

  if (Name[0] == '_') {

    // Each name that begins with an underscore followed by an uppercase letter

    // or another underscore is reserved.

    if (Name[1] == '_')

      return ReservedIdentifierStatus::StartsWithDoubleUnderscore;

    if ('A' <= Name[1] && Name[1] <= 'Z')

      return ReservedIdentifierStatus::

          StartsWithUnderscoreFollowedByCapitalLetter;

    // This is a bit misleading: it actually means it's only reserved if we're

    // at global scope because it starts with an underscore.

    return ReservedIdentifierStatus::StartsWithUnderscoreAtGlobalScope;

  }

  // Each name that contains a double underscore (__) is reserved.

  if (LangOpts.CPlusPlus && Name.contains("__"))

    return ReservedIdentifierStatus::ContainsDoubleUnderscore;

  return ReservedIdentifierStatus::NotReserved;

}

ReservedLiteralSuffixIdStatus

IdentifierInfo::isReservedLiteralSuffixId() const {

  StringRef Name = getName();

  if (Name[0] != '_')

    return ReservedLiteralSuffixIdStatus::NotStartsWithUnderscore;

  if (Name.contains("__"))

    return ReservedLiteralSuffixIdStatus::ContainsDoubleUnderscore;

  return ReservedLiteralSuffixIdStatus::NotReserved;

}

StringRef IdentifierInfo::deuglifiedName() const {

  StringRef Name = getName();

  if (Name.size() >= 2 && Name.front() == '_' &&

      (Name[1] == '_' || (Name[1] >= 'A' && Name[1] <= 'Z')))

    return Name.ltrim('_');

  return Name;

}

tok::PPKeywordKind IdentifierInfo::getPPKeywordID() const {

  // We use a perfect hash function here involving the length of the keyword,

  // the first and third character.  For preprocessor ID's there are no

  // collisions (if there were, the switch below would complain about duplicate

  // case values).  Note that this depends on 'if' being null terminated.

#define HASH(LEN, FIRST, THIRD) \

  (LEN << 5) + (((FIRST-'a') + (THIRD-'a')) & 31)

#define CASE(LEN, FIRST, THIRD, NAME) \

  case HASH(LEN, FIRST, THIRD): \

    return memcmp(Name, #NAME, LEN) ? tok::pp_not_keyword : tok::pp_ ## NAME

  unsigned Len = getLength();

  if (Len < 2) return tok::pp_not_keyword;

  const char *Name = getNameStart();

  switch (HASH(Len, Name[0], Name[2])) {

  default: return tok::pp_not_keyword;

  CASE( 2, 'i', '\0', if);

  CASE( 4, 'e', 'i', elif);

  CASE( 4, 'e', 's', else);

  CASE( 4, 'l', 'n', line);

  CASE( 4, 's', 'c', sccs);

  CASE( 5, 'e', 'd', endif);

  CASE( 5, 'e', 'r', error);

  CASE( 5, 'i', 'e', ident);

  CASE( 5, 'i', 'd', ifdef);

  CASE( 5, 'u', 'd', undef);

  CASE( 6, 'a', 's', assert);

  CASE( 6, 'd', 'f', define);

  CASE( 6, 'i', 'n', ifndef);

  CASE( 6, 'i', 'p', import);

  CASE( 6, 'p', 'a', pragma);

  CASE( 7, 'd', 'f', defined);

  CASE( 7, 'e', 'i', elifdef);

  CASE( 7, 'i', 'c', include);

  CASE( 7, 'w', 'r', warning);

  CASE( 8, 'e', 'i', elifndef);

  CASE( 8, 'u', 'a', unassert);

  CASE(12, 'i', 'c', include_next);

  CASE(14, '_', 'p', __public_macro);

  CASE(15, '_', 'p', __private_macro);

  CASE(16, '_', 'i', __include_macros);

#undef CASE

#undef HASH

  }

}

//===----------------------------------------------------------------------===//

// Stats Implementation

//===----------------------------------------------------------------------===//

/// PrintStats - Print statistics about how well the identifier table is doing

/// at hashing identifiers.

void IdentifierTable::PrintStats() const {

  unsigned NumBuckets = HashTable.getNumBuckets();

  unsigned NumIdentifiers = HashTable.getNumItems();

  unsigned NumEmptyBuckets = NumBuckets-NumIdentifiers;

  unsigned AverageIdentifierSize = 0;

  unsigned MaxIdentifierLength = 0;

  // TODO: Figure out maximum times an identifier had to probe for -stats.

  for (llvm::StringMap<IdentifierInfo*, llvm::BumpPtrAllocator>::const_iterator

       I = HashTable.begin(), E = HashTable.end(); I != E; ++I) {

    unsigned IdLen = I->getKeyLength();

    AverageIdentifierSize += IdLen;

    if (MaxIdentifierLength < IdLen)

      MaxIdentifierLength = IdLen;

  }

  fprintf(stderr, "\n*** Identifier Table Stats:\n");

  fprintf(stderr, "# Identifiers:   %d\n", NumIdentifiers);

  fprintf(stderr, "# Empty Buckets: %d\n", NumEmptyBuckets);

  fprintf(stderr, "Hash density (#identifiers per bucket): %f\n",

          NumIdentifiers/(double)NumBuckets);

  fprintf(stderr, "Ave identifier length: %f\n",

          (AverageIdentifierSize/(double)NumIdentifiers));

  fprintf(stderr, "Max identifier length: %d\n", MaxIdentifierLength);

  // Compute statistics about the memory allocated for identifiers.

  HashTable.getAllocator().PrintStats();

}

//===----------------------------------------------------------------------===//

// SelectorTable Implementation

//===----------------------------------------------------------------------===//

unsigned llvm::DenseMapInfo<clang::Selector>::getHashValue(clang::Selector S) {

  return DenseMapInfo<void*>::getHashValue(S.getAsOpaquePtr());

}

bool Selector::isKeywordSelector(ArrayRef<StringRef> Names) const {

  assert(!Names.empty() && "must have >= 1 selector slots");

  if (getNumArgs() != Names.size())

    return false;

  for (unsigned I = 0, E = Names.size(); I != E; ++I) {

    if (getNameForSlot(I) != Names[I])

      return false;

  }

  return true;

}

bool Selector::isUnarySelector(StringRef Name) const {

  return isUnarySelector() && getNameForSlot(0) == Name;

}

unsigned Selector::getNumArgs() const {

  unsigned IIF = getIdentifierInfoFlag();

  if (IIF <= ZeroArg)

    return 0;

  if (IIF == OneArg)

    return 1;

  // We point to a MultiKeywordSelector.

  MultiKeywordSelector *SI = getMultiKeywordSelector();

  return SI->getNumArgs();

}

IdentifierInfo *Selector::getIdentifierInfoForSlot(unsigned argIndex) const {

  if (getIdentifierInfoFlag() < MultiArg) {

    assert(argIndex == 0 && "illegal keyword index");

    return getAsIdentifierInfo();

  }

  // We point to a MultiKeywordSelector.

  MultiKeywordSelector *SI = getMultiKeywordSelector();

  return SI->getIdentifierInfoForSlot(argIndex);

}

StringRef Selector::getNameForSlot(unsigned int argIndex) const {

  IdentifierInfo *II = getIdentifierInfoForSlot(argIndex);

  return II ? II->getName() : StringRef();

}

std::string MultiKeywordSelector::getName() const {

  SmallString<256> Str;

  llvm::raw_svector_ostream OS(Str);

  for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) {

    if (*I)

      OS << (*I)->getName();

    OS << ':';

  }

  return std::string(OS.str());

}

std::string Selector::getAsString() const {

  if (isNull())

    return "<null selector>";

  if (getIdentifierInfoFlag() < MultiArg) {

    IdentifierInfo *II = getAsIdentifierInfo();

    if (getNumArgs() == 0) {

      assert(II && "If the number of arguments is 0 then II is guaranteed to "

                   "not be null.");

      return std::string(II->getName());

    }

    if (!II)

      return ":";

    return II->getName().str() + ":";

  }

  // We have a multiple keyword selector.

  return getMultiKeywordSelector()->getName();

}

void Selector::print(llvm::raw_ostream &OS) const {

  OS << getAsString();

}

LLVM_DUMP_METHOD void Selector::dump() const { print(llvm::errs()); }

/// Interpreting the given string using the normal CamelCase

/// conventions, determine whether the given string starts with the

/// given "word", which is assumed to end in a lowercase letter.

static bool startsWithWord(StringRef name, StringRef word) {

  if (name.size() < word.size()) return false;

  return ((name.size() == word.size() || !isLowercase(name[word.size()])) &&

          name.starts_with(word));

}

ObjCMethodFamily Selector::getMethodFamilyImpl(Selector sel) {

  IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);

  if (!first) return OMF_None;

  StringRef name = first->getName();

  if (sel.isUnarySelector()) {

    if (name == "autorelease") return OMF_autorelease;

    if (name == "dealloc") return OMF_dealloc;

    if (name == "finalize") return OMF_finalize;

    if (name == "release") return OMF_release;

    if (name == "retain") return OMF_retain;

    if (name == "retainCount") return OMF_retainCount;

    if (name == "self") return OMF_self;

    if (name == "initialize") return OMF_initialize;

  }

  if (name == "performSelector" || name == "performSelectorInBackground" ||

      name == "performSelectorOnMainThread")

    return OMF_performSelector;

  // The other method families may begin with a prefix of underscores.

  name = name.ltrim('_');

  if (name.empty()) return OMF_None;

  switch (name.front()) {

  case 'a':

    if (startsWithWord(name, "alloc")) return OMF_alloc;

    break;

  case 'c':

    if (startsWithWord(name, "copy")) return OMF_copy;

    break;

  case 'i':

    if (startsWithWord(name, "init")) return OMF_init;

    break;

  case 'm':

    if (startsWithWord(name, "mutableCopy")) return OMF_mutableCopy;

    break;

  case 'n':

    if (startsWithWord(name, "new")) return OMF_new;

    break;

  default:

    break;

  }

  return OMF_None;

}

ObjCInstanceTypeFamily Selector::getInstTypeMethodFamily(Selector sel) {

  IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);

  if (!first) return OIT_None;

  StringRef name = first->getName();

  if (name.empty()) return OIT_None;

  switch (name.front()) {

    case 'a':

      if (startsWithWord(name, "array")) return OIT_Array;

      break;

    case 'd':

      if (startsWithWord(name, "default")) return OIT_ReturnsSelf;

      if (startsWithWord(name, "dictionary")) return OIT_Dictionary;

      break;

    case 's':

      if (startsWithWord(name, "shared")) return OIT_ReturnsSelf;

      if (startsWithWord(name, "standard")) return OIT_Singleton;

      break;

    case 'i':

      if (startsWithWord(name, "init")) return OIT_Init;

      break;

    default:

      break;

  }

  return OIT_None;

}

ObjCStringFormatFamily Selector::getStringFormatFamilyImpl(Selector sel) {

  IdentifierInfo *first = sel.getIdentifierInfoForSlot(0);

  if (!first) return SFF_None;

  StringRef name = first->getName();

  switch (name.front()) {

    case 'a':

      if (name == "appendFormat") return SFF_NSString;

      break;

    case 'i':

      if (name == "initWithFormat") return SFF_NSString;

      break;

    case 'l':

      if (name == "localizedStringWithFormat") return SFF_NSString;

      break;

    case 's':

      if (name == "stringByAppendingFormat" ||

          name == "stringWithFormat") return SFF_NSString;

      break;

  }

  return SFF_None;

}

namespace {

struct SelectorTableImpl {

  llvm::FoldingSet<MultiKeywordSelector> Table;

  llvm::BumpPtrAllocator Allocator;

};

} // namespace

static SelectorTableImpl &getSelectorTableImpl(void *P) {

  return *static_cast<SelectorTableImpl*>(P);

}

SmallString<64>

SelectorTable::constructSetterName(StringRef Name) {

  SmallString<64> SetterName("set");

  SetterName += Name;

  SetterName[3] = toUppercase(SetterName[3]);

  return SetterName;

}

Selector

SelectorTable::constructSetterSelector(IdentifierTable &Idents,

                                       SelectorTable &SelTable,

                                       const IdentifierInfo *Name) {

  IdentifierInfo *SetterName =

    &Idents.get(constructSetterName(Name->getName()));

  return SelTable.getUnarySelector(SetterName);

}

std::string SelectorTable::getPropertyNameFromSetterSelector(Selector Sel) {

  StringRef Name = Sel.getNameForSlot(0);

  assert(Name.starts_with("set") && "invalid setter name");

  return (Twine(toLowercase(Name[3])) + Name.drop_front(4)).str();

}

size_t SelectorTable::getTotalMemory() const {

  SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl);

  return SelTabImpl.Allocator.getTotalMemory();

}

Selector SelectorTable::getSelector(unsigned nKeys, IdentifierInfo **IIV) {

  if (nKeys < 2)

    return Selector(IIV[0], nKeys);

  SelectorTableImpl &SelTabImpl = getSelectorTableImpl(Impl);

  // Unique selector, to guarantee there is one per name.

  llvm::FoldingSetNodeID ID;

  MultiKeywordSelector::Profile(ID, IIV, nKeys);

  void *InsertPos = nullptr;

  if (MultiKeywordSelector *SI =

        SelTabImpl.Table.FindNodeOrInsertPos(ID, InsertPos))

    return Selector(SI);

  // MultiKeywordSelector objects are not allocated with new because they have a

  // variable size array (for parameter types) at the end of them.

  unsigned Size = sizeof(MultiKeywordSelector) + nKeys*sizeof(IdentifierInfo *);

  MultiKeywordSelector *SI =

      (MultiKeywordSelector *)SelTabImpl.Allocator.Allocate(

          Size, alignof(MultiKeywordSelector));

  new (SI) MultiKeywordSelector(nKeys, IIV);

  SelTabImpl.Table.InsertNode(SI, InsertPos);

  return Selector(SI);

}

SelectorTable::SelectorTable() {

  Impl = new SelectorTableImpl();

}

SelectorTable::~SelectorTable() {

  delete &getSelectorTableImpl(Impl);

}

const char *clang::getOperatorSpelling(OverloadedOperatorKind Operator) {

  switch (Operator) {

  case OO_None:

  case NUM_OVERLOADED_OPERATORS:

    return nullptr;

#define OVERLOADED_OPERATOR(Name,Spelling,Token,Unary,Binary,MemberOnly) \

  case OO_##Name: return Spelling;

#include "clang/Basic/OperatorKinds.def"

  }

  llvm_unreachable("Invalid OverloadedOperatorKind!");

}

StringRef clang::getNullabilitySpelling(NullabilityKind kind,

                                        bool isContextSensitive) {

  switch (kind) {

  case NullabilityKind::NonNull:

    return isContextSensitive ? "nonnull" : "_Nonnull";

  case NullabilityKind::Nullable:

    return isContextSensitive ? "nullable" : "_Nullable";

  case NullabilityKind::NullableResult:

    assert(!isContextSensitive &&

           "_Nullable_result isn't supported as context-sensitive keyword");

    return "_Nullable_result";

  case NullabilityKind::Unspecified:

    return isContextSensitive ? "null_unspecified" : "_Null_unspecified";

  }

  llvm_unreachable("Unknown nullability kind.");

}

llvm::raw_ostream &clang::operator<<(llvm::raw_ostream &OS,

                                     NullabilityKind NK) {

  switch (NK) {

  case NullabilityKind::NonNull:

    return OS << "NonNull";

  case NullabilityKind::Nullable:

    return OS << "Nullable";

  case NullabilityKind::NullableResult:

    return OS << "NullableResult";

  case NullabilityKind::Unspecified:

    return OS << "Unspecified";

  }

  llvm_unreachable("Unknown nullability kind.");

}

diag::kind

IdentifierTable::getFutureCompatDiagKind(const IdentifierInfo &II,

                                         const LangOptions &LangOpts) {

  assert(II.isFutureCompatKeyword() && "diagnostic should not be needed");

  unsigned Flags = llvm::StringSwitch<unsigned>(II.getName())

#define KEYWORD(NAME, FLAGS) .Case(#NAME, FLAGS)

#include "clang/Basic/TokenKinds.def"

#undef KEYWORD

      ;

  if (LangOpts.CPlusPlus) {

    if ((Flags & KEYCXX11) == KEYCXX11)

      return diag::warn_cxx11_keyword;

    // char8_t is not modeled as a CXX20_KEYWORD because it's not

    // unconditionally enabled in C++20 mode. (It can be disabled

    // by -fno-char8_t.)

    if (((Flags & KEYCXX20) == KEYCXX20) ||

        ((Flags & CHAR8SUPPORT) == CHAR8SUPPORT))

      return diag::warn_cxx20_keyword;

  } else {

    if ((Flags & KEYC99) == KEYC99)

      return diag::warn_c99_keyword;

    if ((Flags & KEYC23) == KEYC23)

      return diag::warn_c23_keyword;

  }

  llvm_unreachable(

      "Keyword not known to come from a newer Standard or proposed Standard");

}