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//===--- 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/IdentifierTable.h"
#include "clang/Basic/LangOptions.h"
#include "llvm/ADT/FoldingSet.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Bitcode/Serialize.h"
#include "llvm/Bitcode/Deserialize.h"
using namespace clang;
//===----------------------------------------------------------------------===//
// IdentifierInfo Implementation
//===----------------------------------------------------------------------===//
IdentifierInfo::IdentifierInfo() {
TokenID = tok::identifier;
ObjCID = tok::objc_not_keyword;
BuiltinID = 0;
HasMacro = false;
IsExtension = false;
IsPoisoned = false;
IsCPPOperatorKeyword = false;
FETokenInfo = 0;
}
//===----------------------------------------------------------------------===//
// IdentifierTable Implementation
//===----------------------------------------------------------------------===//
IdentifierTable::IdentifierTable(const LangOptions &LangOpts)
// Start with space for 8K identifiers.
: HashTable(8192) {
// Populate the identifier table with info about keywords for the current
// language.
AddKeywords(LangOpts);
}
// This cstor is intended to be used only for serialization.
IdentifierTable::IdentifierTable() : HashTable(8192) {}
//===----------------------------------------------------------------------===//
// Language Keyword Implementation
//===----------------------------------------------------------------------===//
/// 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.
///
/// The C90/C99/CPP/CPP0x flags are set to 0 if the token should be
/// enabled in the specified langauge, set to 1 if it is an extension
/// in the specified language, and set to 2 if disabled in the
/// specified language.
static void AddKeyword(const char *Keyword, unsigned KWLen,
tok::TokenKind TokenCode,
int C90, int C99, int CXX, int CXX0x, int BoolSupport,
const LangOptions &LangOpts, IdentifierTable &Table) {
int Flags = 0;
if (BoolSupport != 0) {
Flags = LangOpts.CPlusPlus? 0 : LangOpts.Boolean ? BoolSupport : 2;
} else if (LangOpts.CPlusPlus) {
Flags = LangOpts.CPlusPlus0x ? CXX0x : CXX;
} else if (LangOpts.C99) {
Flags = C99;
} else {
Flags = C90;
}
// Don't add this keyword if disabled in this language or if an extension
// and extensions are disabled.
if (Flags + LangOpts.NoExtensions >= 2) return;
IdentifierInfo &Info = Table.get(Keyword, Keyword+KWLen);
Info.setTokenID(TokenCode);
Info.setIsExtensionToken(Flags == 1);
}
static void AddAlias(const char *Keyword, unsigned KWLen,
tok::TokenKind AliaseeID,
const char *AliaseeKeyword, unsigned AliaseeKWLen,
const LangOptions &LangOpts, IdentifierTable &Table) {
IdentifierInfo &AliasInfo = Table.get(Keyword, Keyword+KWLen);
IdentifierInfo &AliaseeInfo = Table.get(AliaseeKeyword,
AliaseeKeyword+AliaseeKWLen);
AliasInfo.setTokenID(AliaseeID);
AliasInfo.setIsExtensionToken(AliaseeInfo.isExtensionToken());
}
/// AddCXXOperatorKeyword - Register a C++ operator keyword alternative
/// representations.
static void AddCXXOperatorKeyword(const char *Keyword, unsigned KWLen,
tok::TokenKind TokenCode,
IdentifierTable &Table) {
IdentifierInfo &Info = Table.get(Keyword, Keyword + KWLen);
Info.setTokenID(TokenCode);
Info.setIsCPlusPlusOperatorKeyword();
}
/// AddObjCKeyword - Register an Objective-C @keyword like "class" "selector" or
/// "property".
static void AddObjCKeyword(tok::ObjCKeywordKind ObjCID,
const char *Name, unsigned NameLen,
IdentifierTable &Table) {
Table.get(Name, Name+NameLen).setObjCKeywordID(ObjCID);
}
/// AddKeywords - Add all keywords to the symbol table.
///
void IdentifierTable::AddKeywords(const LangOptions &LangOpts) {
enum {
C90Shift = 0,
EXTC90 = 1 << C90Shift,
NOTC90 = 2 << C90Shift,
C99Shift = 2,
EXTC99 = 1 << C99Shift,
NOTC99 = 2 << C99Shift,
CPPShift = 4,
EXTCPP = 1 << CPPShift,
NOTCPP = 2 << CPPShift,
CPP0xShift = 6,
EXTCPP0x = 1 << CPP0xShift,
NOTCPP0x = 2 << CPP0xShift,
BoolShift = 8,
BOOLSUPPORT = 1 << BoolShift,
Mask = 3
};
// Add keywords and tokens for the current language.
#define KEYWORD(NAME, FLAGS) \
AddKeyword(#NAME, strlen(#NAME), tok::kw_ ## NAME, \
((FLAGS) >> C90Shift) & Mask, \
((FLAGS) >> C99Shift) & Mask, \
((FLAGS) >> CPPShift) & Mask, \
((FLAGS) >> CPP0xShift) & Mask, \
((FLAGS) >> BoolShift) & Mask, LangOpts, *this);
#define ALIAS(NAME, TOK) \
AddAlias(NAME, strlen(NAME), tok::kw_ ## TOK, #TOK, strlen(#TOK), \
LangOpts, *this);
#define CXX_KEYWORD_OPERATOR(NAME, ALIAS) \
if (LangOpts.CXXOperatorNames) \
AddCXXOperatorKeyword(#NAME, strlen(#NAME), tok::ALIAS, *this);
#define OBJC1_AT_KEYWORD(NAME) \
if (LangOpts.ObjC1) \
AddObjCKeyword(tok::objc_##NAME, #NAME, strlen(#NAME), *this);
#define OBJC2_AT_KEYWORD(NAME) \
if (LangOpts.ObjC2) \
AddObjCKeyword(tok::objc_##NAME, #NAME, strlen(#NAME), *this);
#include "clang/Basic/TokenKinds.def"
}
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 = getName();
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);
#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());
}
/// 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.
namespace clang {
class MultiKeywordSelector : public llvm::FoldingSetNode {
friend SelectorTable* SelectorTable::CreateAndRegister(llvm::Deserializer&);
MultiKeywordSelector(unsigned nKeys) : NumArgs(nKeys) {}
public:
unsigned NumArgs;
// Constructor for keyword selectors.
MultiKeywordSelector(unsigned nKeys, IdentifierInfo **IIV) {
assert((nKeys > 1) && "not a multi-keyword selector");
NumArgs = 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 NumArgs; }
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()+NumArgs;
}
IdentifierInfo *getIdentifierInfoForSlot(unsigned i) const {
assert(i < NumArgs && "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(), NumArgs);
}
};
} // 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 (pointer doesn't contain any flags).
MultiKeywordSelector *SI = reinterpret_cast<MultiKeywordSelector *>(InfoPtr);
return SI->getNumArgs();
}
IdentifierInfo *Selector::getIdentifierInfoForSlot(unsigned argIndex) const {
if (IdentifierInfo *II = getAsIdentifierInfo()) {
assert(argIndex == 0 && "illegal keyword index");
return II;
}
// We point to a MultiKeywordSelector (pointer doesn't contain any flags).
MultiKeywordSelector *SI = reinterpret_cast<MultiKeywordSelector *>(InfoPtr);
return SI->getIdentifierInfoForSlot(argIndex);
}
std::string MultiKeywordSelector::getName() const {
std::string Result;
unsigned Length = 0;
for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) {
if (*I)
Length += (*I)->getLength();
++Length; // :
}
Result.reserve(Length);
for (keyword_iterator I = keyword_begin(), E = keyword_end(); I != E; ++I) {
if (*I)
Result.insert(Result.end(), (*I)->getName(),
(*I)->getName()+(*I)->getLength());
Result.push_back(':');
}
return Result;
}
std::string Selector::getName() const {
if (IdentifierInfo *II = getAsIdentifierInfo()) {
if (getNumArgs() == 0)
return II->getName();
std::string Res = II->getName();
Res += ":";
return Res;
}
// We have a multiple keyword selector (no embedded flags).
return reinterpret_cast<MultiKeywordSelector *>(InfoPtr)->getName();
}
Selector SelectorTable::getSelector(unsigned nKeys, IdentifierInfo **IIV) {
if (nKeys < 2)
return Selector(IIV[0], nKeys);
llvm::FoldingSet<MultiKeywordSelector> *SelTab;
SelTab = static_cast<llvm::FoldingSet<MultiKeywordSelector> *>(Impl);
// Unique selector, to guarantee there is one per name.
llvm::FoldingSetNodeID ID;
MultiKeywordSelector::Profile(ID, IIV, nKeys);
void *InsertPos = 0;
if (MultiKeywordSelector *SI = SelTab->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.
MultiKeywordSelector *SI =
(MultiKeywordSelector*)malloc(sizeof(MultiKeywordSelector) +
nKeys*sizeof(IdentifierInfo *));
new (SI) MultiKeywordSelector(nKeys, IIV);
SelTab->InsertNode(SI, InsertPos);
return Selector(SI);
}
SelectorTable::SelectorTable() {
Impl = new llvm::FoldingSet<MultiKeywordSelector>;
}
SelectorTable::~SelectorTable() {
delete static_cast<llvm::FoldingSet<MultiKeywordSelector> *>(Impl);
}
//===----------------------------------------------------------------------===//
// Serialization for IdentifierInfo and IdentifierTable.
//===----------------------------------------------------------------------===//
void IdentifierInfo::Emit(llvm::Serializer& S) const {
S.EmitInt(getTokenID());
S.EmitInt(getBuiltinID());
S.EmitInt(getObjCKeywordID());
S.EmitBool(hasMacroDefinition());
S.EmitBool(isExtensionToken());
S.EmitBool(isPoisoned());
S.EmitBool(isCPlusPlusOperatorKeyword());
// FIXME: FETokenInfo
}
void IdentifierInfo::Read(llvm::Deserializer& D) {
setTokenID((tok::TokenKind) D.ReadInt());
setBuiltinID(D.ReadInt());
setObjCKeywordID((tok::ObjCKeywordKind) D.ReadInt());
setHasMacroDefinition(D.ReadBool());
setIsExtensionToken(D.ReadBool());
setIsPoisoned(D.ReadBool());
setIsCPlusPlusOperatorKeyword(D.ReadBool());
// FIXME: FETokenInfo
}
void IdentifierTable::Emit(llvm::Serializer& S) const {
S.EnterBlock();
S.EmitPtr(this);
for (iterator I=begin(), E=end(); I != E; ++I) {
const char* Key = I->getKeyData();
const IdentifierInfo* Info = &I->getValue();
bool KeyRegistered = S.isRegistered(Key);
bool InfoRegistered = S.isRegistered(Info);
if (KeyRegistered || InfoRegistered) {
// These acrobatics are so that we don't incur the cost of registering
// a pointer with the backpatcher during deserialization if nobody
// references the object.
S.EmitPtr(InfoRegistered ? Info : NULL);
S.EmitPtr(KeyRegistered ? Key : NULL);
S.EmitCStr(Key);
S.Emit(*Info);
}
}
S.ExitBlock();
}
IdentifierTable* IdentifierTable::CreateAndRegister(llvm::Deserializer& D) {
llvm::Deserializer::Location BLoc = D.getCurrentBlockLocation();
std::vector<char> buff;
buff.reserve(200);
IdentifierTable* t = new IdentifierTable();
D.RegisterPtr(t);
while (!D.FinishedBlock(BLoc)) {
llvm::SerializedPtrID InfoPtrID = D.ReadPtrID();
llvm::SerializedPtrID KeyPtrID = D.ReadPtrID();
D.ReadCStr(buff);
llvm::StringMapEntry<IdentifierInfo>& Entry =
t->HashTable.GetOrCreateValue(&buff[0],&buff[0]+buff.size());
D.Read(Entry.getValue());
if (InfoPtrID)
D.RegisterRef(InfoPtrID,Entry.getValue());
if (KeyPtrID)
D.RegisterPtr(KeyPtrID,Entry.getKeyData());
}
return t;
}
//===----------------------------------------------------------------------===//
// Serialization for Selector and SelectorTable.
//===----------------------------------------------------------------------===//
void Selector::Emit(llvm::Serializer& S) const {
S.EmitInt(getIdentifierInfoFlag());
S.EmitPtr(reinterpret_cast<void*>(InfoPtr & ~ArgFlags));
}
Selector Selector::ReadVal(llvm::Deserializer& D) {
unsigned flag = D.ReadInt();
uintptr_t ptr;
D.ReadUIntPtr(ptr,false); // No backpatching.
return Selector(ptr | flag);
}
void SelectorTable::Emit(llvm::Serializer& S) const {
typedef llvm::FoldingSet<MultiKeywordSelector>::iterator iterator;
llvm::FoldingSet<MultiKeywordSelector> *SelTab;
SelTab = static_cast<llvm::FoldingSet<MultiKeywordSelector> *>(Impl);
S.EnterBlock();
S.EmitPtr(this);
for (iterator I=SelTab->begin(), E=SelTab->end(); I != E; ++I) {
if (!S.isRegistered(&*I))
continue;
S.FlushRecord(); // Start a new record.
S.EmitPtr(&*I);
S.EmitInt(I->getNumArgs());
for (MultiKeywordSelector::keyword_iterator KI = I->keyword_begin(),
KE = I->keyword_end(); KI != KE; ++KI)
S.EmitPtr(*KI);
}
S.ExitBlock();
}
SelectorTable* SelectorTable::CreateAndRegister(llvm::Deserializer& D) {
llvm::Deserializer::Location BLoc = D.getCurrentBlockLocation();
SelectorTable* t = new SelectorTable();
D.RegisterPtr(t);
llvm::FoldingSet<MultiKeywordSelector>& SelTab =
*static_cast<llvm::FoldingSet<MultiKeywordSelector>*>(t->Impl);
while (!D.FinishedBlock(BLoc)) {
llvm::SerializedPtrID PtrID = D.ReadPtrID();
unsigned nKeys = D.ReadInt();
MultiKeywordSelector *SI =
(MultiKeywordSelector*)malloc(sizeof(MultiKeywordSelector) +
nKeys*sizeof(IdentifierInfo *));
new (SI) MultiKeywordSelector(nKeys);
D.RegisterPtr(PtrID,SI);
IdentifierInfo **KeyInfo = reinterpret_cast<IdentifierInfo **>(SI+1);
for (unsigned i = 0; i != nKeys; ++i)
D.ReadPtr(KeyInfo[i],false);
SelTab.GetOrInsertNode(SI);
}
return t;
}