//===--- IdentifierTable.cpp - Hash table for identifier lookup -----------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the IdentifierInfo, IdentifierVisitor, and
// IdentifierTable interfaces.
//
//===----------------------------------------------------------------------===//
#include "clang/Basic/CharInfo.h"
#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/LangOptions.h"
#include "clang/Basic/OperatorKinds.h"
#include "clang/Basic/Specifiers.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <cstdio>
using namespace clang;
//===----------------------------------------------------------------------===//
// IdentifierInfo Implementation
//===----------------------------------------------------------------------===//
IdentifierInfo::IdentifierInfo() {
TokenID = tok::identifier;
ObjCOrBuiltinID = 0;
HasMacro = false;
HadMacro = false;
IsExtension = false;
IsFutureCompatKeyword = false;
IsPoisoned = false;
IsCPPOperatorKeyword = false;
NeedsHandleIdentifier = false;
IsFromAST = false;
ChangedAfterLoad = false;
FEChangedAfterLoad = false;
RevertedTokenID = false;
OutOfDate = false;
IsModulesImport = false;
FETokenInfo = nullptr;
Entry = nullptr;
}
//===----------------------------------------------------------------------===//
// IdentifierTable Implementation
//===----------------------------------------------------------------------===//
IdentifierIterator::~IdentifierIterator() { }
IdentifierInfoLookup::~IdentifierInfoLookup() {}
namespace {
/// \brief A simple identifier lookup iterator that represents an
/// empty sequence of identifiers.
class EmptyLookupIterator : public IdentifierIterator
{
public:
StringRef Next() override { return StringRef(); }
};
}
IdentifierIterator *IdentifierInfoLookup::getIdentifiers() {
return new EmptyLookupIterator();
}
IdentifierTable::IdentifierTable(const LangOptions &LangOpts,
IdentifierInfoLookup* externalLookup)
: HashTable(8192), // Start with space for 8K identifiers.
ExternalLookup(externalLookup) {
// Populate the identifier table with info about keywords for the current
// language.
AddKeywords(LangOpts);
// Add the '_experimental_modules_import' contextual keyword.
get("import").setModulesImport(true);
}
//===----------------------------------------------------------------------===//
// Language Keyword Implementation
//===----------------------------------------------------------------------===//
// Constants for TokenKinds.def
namespace {
enum {
KEYC99 = 0x1,
KEYCXX = 0x2,
KEYCXX11 = 0x4,
KEYGNU = 0x8,
KEYMS = 0x10,
BOOLSUPPORT = 0x20,
KEYALTIVEC = 0x40,
KEYNOCXX = 0x80,
KEYBORLAND = 0x100,
KEYOPENCL = 0x200,
KEYC11 = 0x400,
KEYARC = 0x800,
KEYNOMS18 = 0x01000,
KEYNOOPENCL = 0x02000,
WCHARSUPPORT = 0x04000,
HALFSUPPORT = 0x08000,
KEYCONCEPTS = 0x10000,
KEYOBJC2 = 0x20000,
KEYZVECTOR = 0x40000,
KEYCOROUTINES = 0x80000,
KEYALL = (0xfffff & ~KEYNOMS18 &
~KEYNOOPENCL) // KEYNOMS18 and KEYNOOPENCL are used to exclude.
};
/// \brief How a keyword is treated in the selected standard.
enum KeywordStatus {
KS_Disabled, // Disabled
KS_Extension, // Is an extension
KS_Enabled, // Enabled
KS_Future // Is a keyword in future standard
};
}
/// \brief Translates flags as specified in TokenKinds.def into keyword status
/// in the given language standard.
static KeywordStatus getKeywordStatus(const LangOptions &LangOpts,
unsigned Flags) {
if (Flags == KEYALL) return KS_Enabled;
if (LangOpts.CPlusPlus && (Flags & KEYCXX)) return KS_Enabled;
if (LangOpts.CPlusPlus11 && (Flags & KEYCXX11)) return KS_Enabled;
if (LangOpts.C99 && (Flags & KEYC99)) return KS_Enabled;
if (LangOpts.GNUKeywords && (Flags & KEYGNU)) return KS_Extension;
if (LangOpts.MicrosoftExt && (Flags & KEYMS)) return KS_Extension;
if (LangOpts.Borland && (Flags & KEYBORLAND)) return KS_Extension;
if (LangOpts.Bool && (Flags & BOOLSUPPORT)) return KS_Enabled;
if (LangOpts.Half && (Flags & HALFSUPPORT)) return KS_Enabled;
if (LangOpts.WChar && (Flags & WCHARSUPPORT)) return KS_Enabled;
if (LangOpts.AltiVec && (Flags & KEYALTIVEC)) return KS_Enabled;
if (LangOpts.OpenCL && (Flags & KEYOPENCL)) return KS_Enabled;
if (!LangOpts.CPlusPlus && (Flags & KEYNOCXX)) return KS_Enabled;
if (LangOpts.C11 && (Flags & KEYC11)) return KS_Enabled;
// We treat bridge casts as objective-C keywords so we can warn on them
// in non-arc mode.
if (LangOpts.ObjC2 && (Flags & KEYARC)) return KS_Enabled;
if (LangOpts.ConceptsTS && (Flags & KEYCONCEPTS)) return KS_Enabled;
if (LangOpts.ObjC2 && (Flags & KEYOBJC2)) return KS_Enabled;
if (LangOpts.Coroutines && (Flags & KEYCOROUTINES)) return KS_Enabled;
if (LangOpts.CPlusPlus && (Flags & KEYCXX11)) return KS_Future;
return KS_Disabled;
}
/// 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 under MSVCCompat.
if (LangOpts.MSVCCompat && (Flags & KEYNOMS18) &&
!LangOpts.isCompatibleWithMSVC(LangOptions::MSVC2015))
return;
// Don't add this keyword under OpenCL.
if (LangOpts.OpenCL && (Flags & KEYNOOPENCL))
return;
// 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);
}
/// 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 OBJC1_AT_KEYWORD(NAME) \
if (LangOpts.ObjC1) \
AddObjCKeyword(StringRef(#NAME), tok::objc_##NAME, *this);
#define OBJC2_AT_KEYWORD(NAME) \
if (LangOpts.ObjC2) \
AddObjCKeyword(StringRef(#NAME), tok::objc_##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);
}
/// \brief 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;
}
}
/// \brief Returns true if the identifier represents a keyword in the
/// specified language.
bool IdentifierInfo::isKeyword(const LangOptions &LangOpts) {
switch (getTokenKwStatus(LangOpts, getTokenID())) {
case KS_Enabled:
case KS_Extension:
return true;
default:
return false;
}
}
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, 'i', 'c', include);
CASE( 7, 'w', 'r', warning);
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());
}
namespace clang {
/// MultiKeywordSelector - One of these variable length records is kept for each
/// selector containing more than one keyword. We use a folding set
/// to unique aggregate names (keyword selectors in ObjC parlance). Access to
/// this class is provided strictly through Selector.
class MultiKeywordSelector
: public DeclarationNameExtra, public llvm::FoldingSetNode {
MultiKeywordSelector(unsigned nKeys) {
ExtraKindOrNumArgs = NUM_EXTRA_KINDS + nKeys;
}
public:
// Constructor for keyword selectors.
MultiKeywordSelector(unsigned nKeys, IdentifierInfo **IIV) {
assert((nKeys > 1) && "not a multi-keyword selector");
ExtraKindOrNumArgs = NUM_EXTRA_KINDS + nKeys;
// Fill in the trailing keyword array.
IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(this+1);
for (unsigned i = 0; i != nKeys; ++i)
KeyInfo[i] = IIV[i];
}
// getName - Derive the full selector name and return it.
std::string getName() const;
unsigned getNumArgs() const { return ExtraKindOrNumArgs - NUM_EXTRA_KINDS; }
typedef IdentifierInfo *const *keyword_iterator;
keyword_iterator keyword_begin() const {
return reinterpret_cast<keyword_iterator>(this+1);
}
keyword_iterator keyword_end() const {
return keyword_begin()+getNumArgs();
}
IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const {
assert(i < getNumArgs() && "getIdentifierInfoForSlot(): illegal index");
return keyword_begin()[i];
}
static void Profile(llvm::FoldingSetNodeID &ID,
keyword_iterator ArgTys, unsigned NumArgs) {
ID.AddInteger(NumArgs);
for (unsigned i = 0; i != NumArgs; ++i)
ID.AddPointer(ArgTys[i]);
}
void Profile(llvm::FoldingSetNodeID &ID) {
Profile(ID, keyword_begin(), getNumArgs());
}
};
} // end namespace clang.
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 OS.str();
}
std::string Selector::getAsString() const {
if (InfoPtr == 0)
return "<null selector>";
if (getIdentifierInfoFlag() < MultiArg) {
IdentifierInfo *II = getAsIdentifierInfo();
// If the number of arguments is 0 then II is guaranteed to not be null.
if (getNumArgs() == 0)
return 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();
}
/// 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.startswith(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") return OMF_performSelector;
// The other method families may begin with a prefix of underscores.
while (!name.empty() && name.front() == '_')
name = name.substr(1);
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;
case 'i':
if (startsWithWord(name, "init")) return OIT_Init;
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;
};
} // end anonymous 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);
}
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,
llvm::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::Unspecified:
return isContextSensitive ? "null_unspecified" : "_Null_unspecified";
}
llvm_unreachable("Unknown nullability kind.");
}