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//===--- PTHLexer.cpp - Lex from a token stream ---------------------------===//
//
// 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 PTHLexer interface.
//
//===----------------------------------------------------------------------===//
#include "clang/Lex/PTHLexer.h"
#include "clang/Basic/FileManager.h"
#include "clang/Basic/FileSystemStatCache.h"
#include "clang/Basic/IdentifierTable.h"
#include "clang/Basic/OnDiskHashTable.h"
#include "clang/Basic/TokenKinds.h"
#include "clang/Lex/LexDiagnostic.h"
#include "clang/Lex/PTHManager.h"
#include "clang/Lex/Preprocessor.h"
#include "clang/Lex/Token.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/system_error.h"
using namespace clang;
using namespace clang::io;
#define DISK_TOKEN_SIZE (1+1+2+4+4)
//===----------------------------------------------------------------------===//
// PTHLexer methods.
//===----------------------------------------------------------------------===//
PTHLexer::PTHLexer(Preprocessor &PP, FileID FID, const unsigned char *D,
const unsigned char *ppcond, PTHManager &PM)
: PreprocessorLexer(&PP, FID), TokBuf(D), CurPtr(D), LastHashTokPtr(0),
PPCond(ppcond), CurPPCondPtr(ppcond), PTHMgr(PM) {
FileStartLoc = PP.getSourceManager().getLocForStartOfFile(FID);
}
void PTHLexer::Lex(Token& Tok) {
LexNextToken:
//===--------------------------------------==//
// Read the raw token data.
//===--------------------------------------==//
// Shadow CurPtr into an automatic variable.
const unsigned char *CurPtrShadow = CurPtr;
// Read in the data for the token.
unsigned Word0 = ReadLE32(CurPtrShadow);
uint32_t IdentifierID = ReadLE32(CurPtrShadow);
uint32_t FileOffset = ReadLE32(CurPtrShadow);
tok::TokenKind TKind = (tok::TokenKind) (Word0 & 0xFF);
Token::TokenFlags TFlags = (Token::TokenFlags) ((Word0 >> 8) & 0xFF);
uint32_t Len = Word0 >> 16;
CurPtr = CurPtrShadow;
//===--------------------------------------==//
// Construct the token itself.
//===--------------------------------------==//
Tok.startToken();
Tok.setKind(TKind);
Tok.setFlag(TFlags);
assert(!LexingRawMode);
Tok.setLocation(FileStartLoc.getLocWithOffset(FileOffset));
Tok.setLength(Len);
// Handle identifiers.
if (Tok.isLiteral()) {
Tok.setLiteralData((const char*) (PTHMgr.SpellingBase + IdentifierID));
}
else if (IdentifierID) {
MIOpt.ReadToken();
IdentifierInfo *II = PTHMgr.GetIdentifierInfo(IdentifierID-1);
Tok.setIdentifierInfo(II);
// Change the kind of this identifier to the appropriate token kind, e.g.
// turning "for" into a keyword.
Tok.setKind(II->getTokenID());
if (II->isHandleIdentifierCase())
PP->HandleIdentifier(Tok);
return;
}
//===--------------------------------------==//
// Process the token.
//===--------------------------------------==//
if (TKind == tok::eof) {
// Save the end-of-file token.
EofToken = Tok;
// Save 'PP' to 'PPCache' as LexEndOfFile can delete 'this'.
Preprocessor *PPCache = PP;
assert(!ParsingPreprocessorDirective);
assert(!LexingRawMode);
if (LexEndOfFile(Tok))
return;
return PPCache->Lex(Tok);
}
if (TKind == tok::hash && Tok.isAtStartOfLine()) {
LastHashTokPtr = CurPtr - DISK_TOKEN_SIZE;
assert(!LexingRawMode);
PP->HandleDirective(Tok);
if (PP->isCurrentLexer(this))
goto LexNextToken;
return PP->Lex(Tok);
}
if (TKind == tok::eod) {
assert(ParsingPreprocessorDirective);
ParsingPreprocessorDirective = false;
return;
}
MIOpt.ReadToken();
}
bool PTHLexer::LexEndOfFile(Token &Result) {
// If we hit the end of the file while parsing a preprocessor directive,
// end the preprocessor directive first. The next token returned will
// then be the end of file.
if (ParsingPreprocessorDirective) {
ParsingPreprocessorDirective = false; // Done parsing the "line".
return true; // Have a token.
}
assert(!LexingRawMode);
// If we are in a #if directive, emit an error.
while (!ConditionalStack.empty()) {
if (PP->getCodeCompletionFileLoc() != FileStartLoc)
PP->Diag(ConditionalStack.back().IfLoc,
diag::err_pp_unterminated_conditional);
ConditionalStack.pop_back();
}
// Finally, let the preprocessor handle this.
return PP->HandleEndOfFile(Result);
}
// FIXME: We can just grab the last token instead of storing a copy
// into EofToken.
void PTHLexer::getEOF(Token& Tok) {
assert(EofToken.is(tok::eof));
Tok = EofToken;
}
void PTHLexer::DiscardToEndOfLine() {
assert(ParsingPreprocessorDirective && ParsingFilename == false &&
"Must be in a preprocessing directive!");
// We assume that if the preprocessor wishes to discard to the end of
// the line that it also means to end the current preprocessor directive.
ParsingPreprocessorDirective = false;
// Skip tokens by only peeking at their token kind and the flags.
// We don't need to actually reconstruct full tokens from the token buffer.
// This saves some copies and it also reduces IdentifierInfo* lookup.
const unsigned char* p = CurPtr;
while (1) {
// Read the token kind. Are we at the end of the file?
tok::TokenKind x = (tok::TokenKind) (uint8_t) *p;
if (x == tok::eof) break;
// Read the token flags. Are we at the start of the next line?
Token::TokenFlags y = (Token::TokenFlags) (uint8_t) p[1];
if (y & Token::StartOfLine) break;
// Skip to the next token.
p += DISK_TOKEN_SIZE;
}
CurPtr = p;
}
/// SkipBlock - Used by Preprocessor to skip the current conditional block.
bool PTHLexer::SkipBlock() {
assert(CurPPCondPtr && "No cached PP conditional information.");
assert(LastHashTokPtr && "No known '#' token.");
const unsigned char* HashEntryI = 0;
uint32_t TableIdx;
do {
// Read the token offset from the side-table.
uint32_t Offset = ReadLE32(CurPPCondPtr);
// Read the target table index from the side-table.
TableIdx = ReadLE32(CurPPCondPtr);
// Compute the actual memory address of the '#' token data for this entry.
HashEntryI = TokBuf + Offset;
// Optmization: "Sibling jumping". #if...#else...#endif blocks can
// contain nested blocks. In the side-table we can jump over these
// nested blocks instead of doing a linear search if the next "sibling"
// entry is not at a location greater than LastHashTokPtr.
if (HashEntryI < LastHashTokPtr && TableIdx) {
// In the side-table we are still at an entry for a '#' token that
// is earlier than the last one we saw. Check if the location we would
// stride gets us closer.
const unsigned char* NextPPCondPtr =
PPCond + TableIdx*(sizeof(uint32_t)*2);
assert(NextPPCondPtr >= CurPPCondPtr);
// Read where we should jump to.
const unsigned char* HashEntryJ = TokBuf + ReadLE32(NextPPCondPtr);
if (HashEntryJ <= LastHashTokPtr) {
// Jump directly to the next entry in the side table.
HashEntryI = HashEntryJ;
TableIdx = ReadLE32(NextPPCondPtr);
CurPPCondPtr = NextPPCondPtr;
}
}
}
while (HashEntryI < LastHashTokPtr);
assert(HashEntryI == LastHashTokPtr && "No PP-cond entry found for '#'");
assert(TableIdx && "No jumping from #endifs.");
// Update our side-table iterator.
const unsigned char* NextPPCondPtr = PPCond + TableIdx*(sizeof(uint32_t)*2);
assert(NextPPCondPtr >= CurPPCondPtr);
CurPPCondPtr = NextPPCondPtr;
// Read where we should jump to.
HashEntryI = TokBuf + ReadLE32(NextPPCondPtr);
uint32_t NextIdx = ReadLE32(NextPPCondPtr);
// By construction NextIdx will be zero if this is a #endif. This is useful
// to know to obviate lexing another token.
bool isEndif = NextIdx == 0;
// This case can occur when we see something like this:
//
// #if ...
// /* a comment or nothing */
// #elif
//
// If we are skipping the first #if block it will be the case that CurPtr
// already points 'elif'. Just return.
if (CurPtr > HashEntryI) {
assert(CurPtr == HashEntryI + DISK_TOKEN_SIZE);
// Did we reach a #endif? If so, go ahead and consume that token as well.
if (isEndif)
CurPtr += DISK_TOKEN_SIZE*2;
else
LastHashTokPtr = HashEntryI;
return isEndif;
}
// Otherwise, we need to advance. Update CurPtr to point to the '#' token.
CurPtr = HashEntryI;
// Update the location of the last observed '#'. This is useful if we
// are skipping multiple blocks.
LastHashTokPtr = CurPtr;
// Skip the '#' token.
assert(((tok::TokenKind)*CurPtr) == tok::hash);
CurPtr += DISK_TOKEN_SIZE;
// Did we reach a #endif? If so, go ahead and consume that token as well.
if (isEndif) { CurPtr += DISK_TOKEN_SIZE*2; }
return isEndif;
}
SourceLocation PTHLexer::getSourceLocation() {
// getSourceLocation is not on the hot path. It is used to get the location
// of the next token when transitioning back to this lexer when done
// handling a #included file. Just read the necessary data from the token
// data buffer to construct the SourceLocation object.
// NOTE: This is a virtual function; hence it is defined out-of-line.
const unsigned char *OffsetPtr = CurPtr + (DISK_TOKEN_SIZE - 4);
uint32_t Offset = ReadLE32(OffsetPtr);
return FileStartLoc.getLocWithOffset(Offset);
}
//===----------------------------------------------------------------------===//
// PTH file lookup: map from strings to file data.
//===----------------------------------------------------------------------===//
/// PTHFileLookup - This internal data structure is used by the PTHManager
/// to map from FileEntry objects managed by FileManager to offsets within
/// the PTH file.
namespace {
class PTHFileData {
const uint32_t TokenOff;
const uint32_t PPCondOff;
public:
PTHFileData(uint32_t tokenOff, uint32_t ppCondOff)
: TokenOff(tokenOff), PPCondOff(ppCondOff) {}
uint32_t getTokenOffset() const { return TokenOff; }
uint32_t getPPCondOffset() const { return PPCondOff; }
};
class PTHFileLookupCommonTrait {
public:
typedef std::pair<unsigned char, const char*> internal_key_type;
static unsigned ComputeHash(internal_key_type x) {
return llvm::HashString(x.second);
}
static std::pair<unsigned, unsigned>
ReadKeyDataLength(const unsigned char*& d) {
unsigned keyLen = (unsigned) ReadUnalignedLE16(d);
unsigned dataLen = (unsigned) *(d++);
return std::make_pair(keyLen, dataLen);
}
static internal_key_type ReadKey(const unsigned char* d, unsigned) {
unsigned char k = *(d++); // Read the entry kind.
return std::make_pair(k, (const char*) d);
}
};
class PTHFileLookupTrait : public PTHFileLookupCommonTrait {
public:
typedef const FileEntry* external_key_type;
typedef PTHFileData data_type;
static internal_key_type GetInternalKey(const FileEntry* FE) {
return std::make_pair((unsigned char) 0x1, FE->getName());
}
static bool EqualKey(internal_key_type a, internal_key_type b) {
return a.first == b.first && strcmp(a.second, b.second) == 0;
}
static PTHFileData ReadData(const internal_key_type& k,
const unsigned char* d, unsigned) {
assert(k.first == 0x1 && "Only file lookups can match!");
uint32_t x = ::ReadUnalignedLE32(d);
uint32_t y = ::ReadUnalignedLE32(d);
return PTHFileData(x, y);
}
};
class PTHStringLookupTrait {
public:
typedef uint32_t
data_type;
typedef const std::pair<const char*, unsigned>
external_key_type;
typedef external_key_type internal_key_type;
static bool EqualKey(const internal_key_type& a,
const internal_key_type& b) {
return (a.second == b.second) ? memcmp(a.first, b.first, a.second) == 0
: false;
}
static unsigned ComputeHash(const internal_key_type& a) {
return llvm::HashString(StringRef(a.first, a.second));
}
// This hopefully will just get inlined and removed by the optimizer.
static const internal_key_type&
GetInternalKey(const external_key_type& x) { return x; }
static std::pair<unsigned, unsigned>
ReadKeyDataLength(const unsigned char*& d) {
return std::make_pair((unsigned) ReadUnalignedLE16(d), sizeof(uint32_t));
}
static std::pair<const char*, unsigned>
ReadKey(const unsigned char* d, unsigned n) {
assert(n >= 2 && d[n-1] == '\0');
return std::make_pair((const char*) d, n-1);
}
static uint32_t ReadData(const internal_key_type& k, const unsigned char* d,
unsigned) {
return ::ReadUnalignedLE32(d);
}
};
} // end anonymous namespace
typedef OnDiskChainedHashTable<PTHFileLookupTrait> PTHFileLookup;
typedef OnDiskChainedHashTable<PTHStringLookupTrait> PTHStringIdLookup;
//===----------------------------------------------------------------------===//
// PTHManager methods.
//===----------------------------------------------------------------------===//
PTHManager::PTHManager(const llvm::MemoryBuffer* buf, void* fileLookup,
const unsigned char* idDataTable,
IdentifierInfo** perIDCache,
void* stringIdLookup, unsigned numIds,
const unsigned char* spellingBase,
const char* originalSourceFile)
: Buf(buf), PerIDCache(perIDCache), FileLookup(fileLookup),
IdDataTable(idDataTable), StringIdLookup(stringIdLookup),
NumIds(numIds), PP(0), SpellingBase(spellingBase),
OriginalSourceFile(originalSourceFile) {}
PTHManager::~PTHManager() {
delete Buf;
delete (PTHFileLookup*) FileLookup;
delete (PTHStringIdLookup*) StringIdLookup;
free(PerIDCache);
}
static void InvalidPTH(DiagnosticsEngine &Diags, const char *Msg) {
Diags.Report(Diags.getCustomDiagID(DiagnosticsEngine::Error, Msg));
}
PTHManager *PTHManager::Create(const std::string &file,
DiagnosticsEngine &Diags) {
// Memory map the PTH file.
OwningPtr<llvm::MemoryBuffer> File;
if (llvm::MemoryBuffer::getFile(file, File)) {
// FIXME: Add ec.message() to this diag.
Diags.Report(diag::err_invalid_pth_file) << file;
return 0;
}
// Get the buffer ranges and check if there are at least three 32-bit
// words at the end of the file.
const unsigned char *BufBeg = (const unsigned char*)File->getBufferStart();
const unsigned char *BufEnd = (const unsigned char*)File->getBufferEnd();
// Check the prologue of the file.
if ((BufEnd - BufBeg) < (signed)(sizeof("cfe-pth") + 4 + 4) ||
memcmp(BufBeg, "cfe-pth", sizeof("cfe-pth")) != 0) {
Diags.Report(diag::err_invalid_pth_file) << file;
return 0;
}
// Read the PTH version.
const unsigned char *p = BufBeg + (sizeof("cfe-pth"));
unsigned Version = ReadLE32(p);
if (Version < PTHManager::Version) {
InvalidPTH(Diags,
Version < PTHManager::Version
? "PTH file uses an older PTH format that is no longer supported"
: "PTH file uses a newer PTH format that cannot be read");
return 0;
}
// Compute the address of the index table at the end of the PTH file.
const unsigned char *PrologueOffset = p;
if (PrologueOffset >= BufEnd) {
Diags.Report(diag::err_invalid_pth_file) << file;
return 0;
}
// Construct the file lookup table. This will be used for mapping from
// FileEntry*'s to cached tokens.
const unsigned char* FileTableOffset = PrologueOffset + sizeof(uint32_t)*2;
const unsigned char* FileTable = BufBeg + ReadLE32(FileTableOffset);
if (!(FileTable > BufBeg && FileTable < BufEnd)) {
Diags.Report(diag::err_invalid_pth_file) << file;
return 0; // FIXME: Proper error diagnostic?
}
OwningPtr<PTHFileLookup> FL(PTHFileLookup::Create(FileTable, BufBeg));
// Warn if the PTH file is empty. We still want to create a PTHManager
// as the PTH could be used with -include-pth.
if (FL->isEmpty())
InvalidPTH(Diags, "PTH file contains no cached source data");
// Get the location of the table mapping from persistent ids to the
// data needed to reconstruct identifiers.
const unsigned char* IDTableOffset = PrologueOffset + sizeof(uint32_t)*0;
const unsigned char* IData = BufBeg + ReadLE32(IDTableOffset);
if (!(IData >= BufBeg && IData < BufEnd)) {
Diags.Report(diag::err_invalid_pth_file) << file;
return 0;
}
// Get the location of the hashtable mapping between strings and
// persistent IDs.
const unsigned char* StringIdTableOffset = PrologueOffset + sizeof(uint32_t)*1;
const unsigned char* StringIdTable = BufBeg + ReadLE32(StringIdTableOffset);
if (!(StringIdTable >= BufBeg && StringIdTable < BufEnd)) {
Diags.Report(diag::err_invalid_pth_file) << file;
return 0;
}
OwningPtr<PTHStringIdLookup> SL(PTHStringIdLookup::Create(StringIdTable,
BufBeg));
// Get the location of the spelling cache.
const unsigned char* spellingBaseOffset = PrologueOffset + sizeof(uint32_t)*3;
const unsigned char* spellingBase = BufBeg + ReadLE32(spellingBaseOffset);
if (!(spellingBase >= BufBeg && spellingBase < BufEnd)) {
Diags.Report(diag::err_invalid_pth_file) << file;
return 0;
}
// Get the number of IdentifierInfos and pre-allocate the identifier cache.
uint32_t NumIds = ReadLE32(IData);
// Pre-allocate the persistent ID -> IdentifierInfo* cache. We use calloc()
// so that we in the best case only zero out memory once when the OS returns
// us new pages.
IdentifierInfo** PerIDCache = 0;
if (NumIds) {
PerIDCache = (IdentifierInfo**)calloc(NumIds, sizeof(*PerIDCache));
if (!PerIDCache) {
InvalidPTH(Diags, "Could not allocate memory for processing PTH file");
return 0;
}
}
// Compute the address of the original source file.
const unsigned char* originalSourceBase = PrologueOffset + sizeof(uint32_t)*4;
unsigned len = ReadUnalignedLE16(originalSourceBase);
if (!len) originalSourceBase = 0;
// Create the new PTHManager.
return new PTHManager(File.take(), FL.take(), IData, PerIDCache,
SL.take(), NumIds, spellingBase,
(const char*) originalSourceBase);
}
IdentifierInfo* PTHManager::LazilyCreateIdentifierInfo(unsigned PersistentID) {
// Look in the PTH file for the string data for the IdentifierInfo object.
const unsigned char* TableEntry = IdDataTable + sizeof(uint32_t)*PersistentID;
const unsigned char* IDData =
(const unsigned char*)Buf->getBufferStart() + ReadLE32(TableEntry);
assert(IDData < (const unsigned char*)Buf->getBufferEnd());
// Allocate the object.
std::pair<IdentifierInfo,const unsigned char*> *Mem =
Alloc.Allocate<std::pair<IdentifierInfo,const unsigned char*> >();
Mem->second = IDData;
assert(IDData[0] != '\0');
IdentifierInfo *II = new ((void*) Mem) IdentifierInfo();
// Store the new IdentifierInfo in the cache.
PerIDCache[PersistentID] = II;
assert(II->getNameStart() && II->getNameStart()[0] != '\0');
return II;
}
IdentifierInfo* PTHManager::get(StringRef Name) {
PTHStringIdLookup& SL = *((PTHStringIdLookup*)StringIdLookup);
// Double check our assumption that the last character isn't '\0'.
assert(Name.empty() || Name.back() != '\0');
PTHStringIdLookup::iterator I = SL.find(std::make_pair(Name.data(),
Name.size()));
if (I == SL.end()) // No identifier found?
return 0;
// Match found. Return the identifier!
assert(*I > 0);
return GetIdentifierInfo(*I-1);
}
PTHLexer *PTHManager::CreateLexer(FileID FID) {
const FileEntry *FE = PP->getSourceManager().getFileEntryForID(FID);
if (!FE)
return 0;
// Lookup the FileEntry object in our file lookup data structure. It will
// return a variant that indicates whether or not there is an offset within
// the PTH file that contains cached tokens.
PTHFileLookup& PFL = *((PTHFileLookup*)FileLookup);
PTHFileLookup::iterator I = PFL.find(FE);
if (I == PFL.end()) // No tokens available?
return 0;
const PTHFileData& FileData = *I;
const unsigned char *BufStart = (const unsigned char *)Buf->getBufferStart();
// Compute the offset of the token data within the buffer.
const unsigned char* data = BufStart + FileData.getTokenOffset();
// Get the location of pp-conditional table.
const unsigned char* ppcond = BufStart + FileData.getPPCondOffset();
uint32_t Len = ReadLE32(ppcond);
if (Len == 0) ppcond = 0;
assert(PP && "No preprocessor set yet!");
return new PTHLexer(*PP, FID, data, ppcond, *this);
}
//===----------------------------------------------------------------------===//
// 'stat' caching.
//===----------------------------------------------------------------------===//
namespace {
class PTHStatData {
public:
const bool hasStat;
const ino_t ino;
const dev_t dev;
const mode_t mode;
const time_t mtime;
const off_t size;
PTHStatData(ino_t i, dev_t d, mode_t mo, time_t m, off_t s)
: hasStat(true), ino(i), dev(d), mode(mo), mtime(m), size(s) {}
PTHStatData()
: hasStat(false), ino(0), dev(0), mode(0), mtime(0), size(0) {}
};
class PTHStatLookupTrait : public PTHFileLookupCommonTrait {
public:
typedef const char* external_key_type; // const char*
typedef PTHStatData data_type;
static internal_key_type GetInternalKey(const char *path) {
// The key 'kind' doesn't matter here because it is ignored in EqualKey.
return std::make_pair((unsigned char) 0x0, path);
}
static bool EqualKey(internal_key_type a, internal_key_type b) {
// When doing 'stat' lookups we don't care about the kind of 'a' and 'b',
// just the paths.
return strcmp(a.second, b.second) == 0;
}
static data_type ReadData(const internal_key_type& k, const unsigned char* d,
unsigned) {
if (k.first /* File or Directory */) {
if (k.first == 0x1 /* File */) d += 4 * 2; // Skip the first 2 words.
ino_t ino = (ino_t) ReadUnalignedLE32(d);
dev_t dev = (dev_t) ReadUnalignedLE32(d);
mode_t mode = (mode_t) ReadUnalignedLE16(d);
time_t mtime = (time_t) ReadUnalignedLE64(d);
return data_type(ino, dev, mode, mtime, (off_t) ReadUnalignedLE64(d));
}
// Negative stat. Don't read anything.
return data_type();
}
};
class PTHStatCache : public FileSystemStatCache {
typedef OnDiskChainedHashTable<PTHStatLookupTrait> CacheTy;
CacheTy Cache;
public:
PTHStatCache(PTHFileLookup &FL) :
Cache(FL.getNumBuckets(), FL.getNumEntries(), FL.getBuckets(),
FL.getBase()) {}
~PTHStatCache() {}
LookupResult getStat(const char *Path, struct stat &StatBuf,
bool isFile, int *FileDescriptor) {
// Do the lookup for the file's data in the PTH file.
CacheTy::iterator I = Cache.find(Path);
// If we don't get a hit in the PTH file just forward to 'stat'.
if (I == Cache.end())
return statChained(Path, StatBuf, isFile, FileDescriptor);
const PTHStatData &Data = *I;
if (!Data.hasStat)
return CacheMissing;
StatBuf.st_ino = Data.ino;
StatBuf.st_dev = Data.dev;
StatBuf.st_mtime = Data.mtime;
StatBuf.st_mode = Data.mode;
StatBuf.st_size = Data.size;
return CacheExists;
}
};
} // end anonymous namespace
FileSystemStatCache *PTHManager::createStatCache() {
return new PTHStatCache(*((PTHFileLookup*) FileLookup));
}