| //===--- CacheTokens.cpp - Caching of lexer tokens for PCH support --------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This provides a possible implementation of PCH support for Clang that is |
| // based on caching lexed tokens and identifiers. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang.h" |
| #include "clang/Basic/FileManager.h" |
| #include "clang/Basic/SourceManager.h" |
| #include "clang/Basic/IdentifierTable.h" |
| #include "clang/Basic/Diagnostic.h" |
| #include "clang/Lex/Lexer.h" |
| #include "clang/Lex/Preprocessor.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/System/Path.h" |
| |
| using namespace clang; |
| |
| typedef uint32_t Offset; |
| |
| typedef llvm::DenseMap<const FileEntry*,std::pair<Offset,Offset> > PCHMap; |
| typedef llvm::DenseMap<const IdentifierInfo*,uint32_t> IDMap; |
| |
| static void Emit8(llvm::raw_ostream& Out, uint32_t V) { |
| Out << (unsigned char)(V); |
| } |
| |
| static void Emit32(llvm::raw_ostream& Out, uint32_t V) { |
| Out << (unsigned char)(V); |
| Out << (unsigned char)(V >> 8); |
| Out << (unsigned char)(V >> 16); |
| Out << (unsigned char)(V >> 24); |
| } |
| |
| static void Emit16(llvm::raw_ostream& Out, uint32_t V) { |
| Out << (unsigned char)(V); |
| Out << (unsigned char)(V >> 8); |
| assert((V >> 16) == 0); |
| } |
| |
| static void Emit24(llvm::raw_ostream& Out, uint32_t V) { |
| Out << (unsigned char)(V); |
| Out << (unsigned char)(V >> 8); |
| Out << (unsigned char)(V >> 16); |
| assert((V >> 24) == 0); |
| } |
| |
| static void EmitBuf(llvm::raw_ostream& Out, const char* I, const char* E) { |
| for ( ; I != E ; ++I) Out << *I; |
| } |
| |
| static uint32_t ResolveID(IDMap& IM, uint32_t& idx, const IdentifierInfo* II) { |
| |
| // Null IdentifierInfo's map to the persistent ID 0. |
| if (!II) |
| return 0; |
| |
| IDMap::iterator I = IM.find(II); |
| |
| if (I == IM.end()) { |
| IM[II] = ++idx; // Pre-increment since '0' is reserved for NULL. |
| return idx; |
| } |
| |
| return I->second; // We've already added 1. |
| } |
| |
| static void EmitToken(llvm::raw_ostream& Out, const Token& T, |
| const SourceManager& SMgr, |
| uint32_t& idcount, IDMap& IM) { |
| |
| Emit8(Out, T.getKind()); |
| Emit8(Out, T.getFlags()); |
| Emit24(Out, ResolveID(IM, idcount, T.getIdentifierInfo())); |
| Emit32(Out, SMgr.getFullFilePos(T.getLocation())); |
| Emit16(Out, T.getLength()); |
| } |
| |
| struct IDData { |
| const IdentifierInfo* II; |
| uint32_t FileOffset; |
| const IdentifierTable::const_iterator::value_type* Str; |
| }; |
| |
| static std::pair<Offset,Offset> |
| EmitIdentifierTable(llvm::raw_fd_ostream& Out, uint32_t max, |
| const IdentifierTable& T, const IDMap& IM) { |
| |
| // Build an inverse map from persistent IDs -> IdentifierInfo*. |
| typedef std::vector<IDData> InverseIDMap; |
| InverseIDMap IIDMap; |
| IIDMap.resize(max); |
| |
| // Generate mapping from persistent IDs -> IdentifierInfo*. |
| for (IDMap::const_iterator I=IM.begin(), E=IM.end(); I!=E; ++I) { |
| // Decrement by 1 because we are using a vector for the lookup and |
| // 0 is reserved for NULL. |
| assert(I->second > 0); |
| assert(I->second-1 < IIDMap.size()); |
| IIDMap[I->second-1].II = I->first; |
| } |
| |
| // Get the string data associated with the IdentifierInfo. |
| for (IdentifierTable::const_iterator I=T.begin(), E=T.end(); I!=E; ++I) { |
| IDMap::const_iterator IDI = IM.find(&(I->getValue())); |
| if (IDI == IM.end()) continue; |
| IIDMap[IDI->second-1].Str = &(*I); |
| } |
| |
| Offset DataOff = Out.tell(); |
| |
| for (InverseIDMap::iterator I=IIDMap.begin(), E=IIDMap.end(); I!=E; ++I) { |
| // Record the location for this data. |
| I->FileOffset = Out.tell(); |
| // Write out the keyword. |
| unsigned len = I->Str->getKeyLength(); |
| Emit32(Out, len); |
| const char* buf = I->Str->getKeyData(); |
| EmitBuf(Out, buf, buf+len); |
| } |
| |
| // Now emit the table mapping from persistent IDs to PTH file offsets. |
| Offset IDOff = Out.tell(); |
| |
| // Emit the number of identifiers. |
| Emit32(Out, max); |
| |
| for (InverseIDMap::iterator I=IIDMap.begin(), E=IIDMap.end(); I!=E; ++I) |
| Emit32(Out, I->FileOffset); |
| |
| return std::make_pair(DataOff, IDOff); |
| } |
| |
| Offset EmitFileTable(llvm::raw_fd_ostream& Out, SourceManager& SM, PCHMap& PM) { |
| |
| Offset off = (Offset) Out.tell(); |
| |
| // Output the size of the table. |
| Emit32(Out, PM.size()); |
| |
| for (PCHMap::iterator I=PM.begin(), E=PM.end(); I!=E; ++I) { |
| const FileEntry* FE = I->first; |
| const char* Name = FE->getName(); |
| unsigned size = strlen(Name); |
| Emit32(Out, size); |
| EmitBuf(Out, Name, Name+size); |
| Emit32(Out, I->second.first); |
| Emit32(Out, I->second.second); |
| } |
| |
| return off; |
| } |
| |
| static std::pair<Offset,Offset> |
| LexTokens(llvm::raw_fd_ostream& Out, Lexer& L, Preprocessor& PP, |
| uint32_t& idcount, IDMap& IM) { |
| |
| // Record the location within the token file. |
| Offset off = (Offset) Out.tell(); |
| SourceManager& SMgr = PP.getSourceManager(); |
| |
| // Keep track of matching '#if' ... '#endif'. |
| typedef std::vector<std::pair<Offset, unsigned> > PPCondTable; |
| PPCondTable PPCond; |
| std::vector<unsigned> PPStartCond; |
| bool ParsingPreprocessorDirective = false; |
| |
| Token Tok; |
| |
| do { |
| L.LexFromRawLexer(Tok); |
| |
| if ((Tok.isAtStartOfLine() || Tok.is(tok::eof)) && |
| ParsingPreprocessorDirective) { |
| // Insert an eom token into the token cache. It has the same |
| // position as the next token that is not on the same line as the |
| // preprocessor directive. Observe that we continue processing |
| // 'Tok' when we exit this branch. |
| Token Tmp = Tok; |
| Tmp.setKind(tok::eom); |
| Tmp.clearFlag(Token::StartOfLine); |
| Tmp.setIdentifierInfo(0); |
| EmitToken(Out, Tmp, SMgr, idcount, IM); |
| ParsingPreprocessorDirective = false; |
| } |
| |
| if (Tok.is(tok::identifier)) { |
| Tok.setIdentifierInfo(PP.LookUpIdentifierInfo(Tok)); |
| continue; |
| } |
| |
| if (Tok.is(tok::hash) && Tok.isAtStartOfLine()) { |
| // Special processing for #include. Store the '#' token and lex |
| // the next token. |
| assert(!ParsingPreprocessorDirective); |
| Offset HashOff = (Offset) Out.tell(); |
| EmitToken(Out, Tok, SMgr, idcount, IM); |
| |
| // Get the next token. |
| L.LexFromRawLexer(Tok); |
| |
| assert(!Tok.isAtStartOfLine()); |
| |
| // Did we see 'include'/'import'/'include_next'? |
| if (!Tok.is(tok::identifier)) |
| continue; |
| |
| IdentifierInfo* II = PP.LookUpIdentifierInfo(Tok); |
| Tok.setIdentifierInfo(II); |
| tok::PPKeywordKind K = II->getPPKeywordID(); |
| |
| assert(K != tok::pp_not_keyword); |
| ParsingPreprocessorDirective = true; |
| |
| switch (K) { |
| default: |
| break; |
| case tok::pp_include: |
| case tok::pp_import: |
| case tok::pp_include_next: { |
| // Save the 'include' token. |
| EmitToken(Out, Tok, SMgr, idcount, IM); |
| // Lex the next token as an include string. |
| L.setParsingPreprocessorDirective(true); |
| L.LexIncludeFilename(Tok); |
| L.setParsingPreprocessorDirective(false); |
| assert(!Tok.isAtStartOfLine()); |
| if (Tok.is(tok::identifier)) |
| Tok.setIdentifierInfo(PP.LookUpIdentifierInfo(Tok)); |
| |
| break; |
| } |
| case tok::pp_if: |
| case tok::pp_ifdef: |
| case tok::pp_ifndef: { |
| // Ad an entry for '#if' and friends. We initially set the target index |
| // to 0. This will get backpatched when we hit #endif. |
| PPStartCond.push_back(PPCond.size()); |
| PPCond.push_back(std::make_pair(HashOff, 0U)); |
| break; |
| } |
| case tok::pp_endif: { |
| // Add an entry for '#endif'. We set the target table index to itself. |
| // This will later be set to zero when emitting to the PTH file. We |
| // use 0 for uninitialized indices because that is easier to debug. |
| unsigned index = PPCond.size(); |
| // Backpatch the opening '#if' entry. |
| assert(!PPStartCond.empty()); |
| assert(PPCond.size() > PPStartCond.back()); |
| assert(PPCond[PPStartCond.back()].second == 0); |
| PPCond[PPStartCond.back()].second = index; |
| PPStartCond.pop_back(); |
| // Add the new entry to PPCond. |
| PPCond.push_back(std::make_pair(HashOff, index)); |
| break; |
| } |
| case tok::pp_elif: |
| case tok::pp_else: { |
| // Add an entry for #elif or #else. |
| // This serves as both a closing and opening of a conditional block. |
| // This means that its entry will get backpatched later. |
| unsigned index = PPCond.size(); |
| // Backpatch the previous '#if' entry. |
| assert(!PPStartCond.empty()); |
| assert(PPCond.size() > PPStartCond.back()); |
| assert(PPCond[PPStartCond.back()].second == 0); |
| PPCond[PPStartCond.back()].second = index; |
| PPStartCond.pop_back(); |
| // Now add '#elif' as a new block opening. |
| PPCond.push_back(std::make_pair(HashOff, 0U)); |
| PPStartCond.push_back(index); |
| break; |
| } |
| } |
| } |
| } |
| while (EmitToken(Out, Tok, SMgr, idcount, IM), Tok.isNot(tok::eof)); |
| |
| assert(PPStartCond.empty() && "Error: imblanced preprocessor conditionals."); |
| |
| // Next write out PPCond. |
| Offset PPCondOff = (Offset) Out.tell(); |
| |
| // Write out the size of PPCond so that clients can identifer empty tables. |
| Emit32(Out, PPCond.size()); |
| |
| for (unsigned i = 0, e = PPCond.size(); i!=e; ++i) { |
| Emit32(Out, PPCond[i].first - off); |
| uint32_t x = PPCond[i].second; |
| assert(x != 0 && "PPCond entry not backpatched."); |
| // Emit zero for #endifs. This allows us to do checking when |
| // we read the PTH file back in. |
| Emit32(Out, x == i ? 0 : x); |
| } |
| |
| return std::make_pair(off,PPCondOff); |
| } |
| |
| void clang::CacheTokens(Preprocessor& PP, const std::string& OutFile) { |
| // Lex through the entire file. This will populate SourceManager with |
| // all of the header information. |
| Token Tok; |
| PP.EnterMainSourceFile(); |
| do { PP.Lex(Tok); } while (Tok.isNot(tok::eof)); |
| |
| // Iterate over all the files in SourceManager. Create a lexer |
| // for each file and cache the tokens. |
| SourceManager& SM = PP.getSourceManager(); |
| const LangOptions& LOpts = PP.getLangOptions(); |
| llvm::raw_ostream& os = llvm::errs(); |
| |
| PCHMap PM; |
| IDMap IM; |
| uint32_t idcount = 0; |
| |
| std::string ErrMsg; |
| llvm::raw_fd_ostream Out(OutFile.c_str(), true, ErrMsg); |
| |
| if (!ErrMsg.empty()) { |
| os << "PTH error: " << ErrMsg << "\n"; |
| return; |
| } |
| |
| for (SourceManager::fileid_iterator I=SM.fileid_begin(), E=SM.fileid_end(); |
| I!=E; ++I) { |
| |
| const SrcMgr::ContentCache* C = I.getFileIDInfo().getContentCache(); |
| if (!C) continue; |
| |
| const FileEntry* FE = C->Entry; // Does this entry correspond to a file? |
| if (!FE) continue; |
| |
| // FIXME: Handle files with non-absolute paths. |
| llvm::sys::Path P(FE->getName()); |
| if (!P.isAbsolute()) |
| continue; |
| |
| PCHMap::iterator PI = PM.find(FE); // Have we already processed this file? |
| if (PI != PM.end()) continue; |
| |
| const llvm::MemoryBuffer* B = C->Buffer; |
| if (!B) continue; |
| |
| Lexer L(SourceLocation::getFileLoc(I.getFileID(), 0), LOpts, |
| B->getBufferStart(), B->getBufferEnd(), B); |
| |
| PM[FE] = LexTokens(Out, L, PP, idcount, IM); |
| } |
| |
| // Write out the identifier table. |
| std::pair<Offset,Offset> IdTableOff = |
| EmitIdentifierTable(Out, idcount, PP.getIdentifierTable(), IM); |
| |
| // Write out the file table. |
| Offset FileTableOff = EmitFileTable(Out, SM, PM); |
| |
| // Finally, write out the offset table at the end. |
| Emit32(Out, IdTableOff.first); |
| Emit32(Out, IdTableOff.second); |
| Emit32(Out, FileTableOff); |
| } |