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Diffstat (limited to 'Lex/IdentifierTable.cpp')
| -rw-r--r-- | Lex/IdentifierTable.cpp | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/Lex/IdentifierTable.cpp b/Lex/IdentifierTable.cpp new file mode 100644 index 0000000000..e671af9839 --- /dev/null +++ b/Lex/IdentifierTable.cpp @@ -0,0 +1,188 @@ +//===--- IdentifierTable.cpp - Hash table for identifier lookup -----------===// +// +// The LLVM Compiler Infrastructure +// +// This file was developed by Chris Lattner and 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/Lex/IdentifierTable.h" +#include "clang/Lex/MacroInfo.h" +#include "clang/Basic/LangOptions.h" +using namespace clang; + +//===----------------------------------------------------------------------===// +// IdentifierInfo Implementation +//===----------------------------------------------------------------------===// + +IdentifierInfo::IdentifierInfo() { + Macro = 0; + TokenID = tok::identifier; + PPID = tok::pp_not_keyword; + ObjCID = tok::objc_not_keyword; + BuiltinID = 0; + IsExtension = false; + IsPoisoned = false; + IsOtherTargetMacro = false; + IsCPPOperatorKeyword = false; + FETokenInfo = 0; +} + +IdentifierInfo::~IdentifierInfo() { + delete Macro; +} + +//===----------------------------------------------------------------------===// +// 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); +} + +//===----------------------------------------------------------------------===// +// 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 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, + const LangOptions &LangOpts, IdentifierTable &Table) { + int Flags = LangOpts.CPlusPlus ? CXX : (LangOpts.C99 ? C99 : 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, + 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(AliaseeInfo.getTokenID()); + AliasInfo.setIsExtensionToken(AliaseeInfo.isExtensionToken()); +} + +/// AddPPKeyword - Register a preprocessor keyword like "define" "undef" or +/// "elif". +static void AddPPKeyword(tok::PPKeywordKind PPID, + const char *Name, unsigned NameLen, + IdentifierTable &Table) { + Table.get(Name, Name+NameLen).setPPKeywordID(PPID); +} + +/// 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, + 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, LangOpts, *this); +#define ALIAS(NAME, TOK) \ + AddAlias(NAME, strlen(NAME), #TOK, strlen(#TOK), LangOpts, *this); +#define PPKEYWORD(NAME) \ + AddPPKeyword(tok::pp_##NAME, #NAME, strlen(#NAME), *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" +} + + +//===----------------------------------------------------------------------===// +// 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(); +} |