Merge branch 'master' of ssh://bitbucket.org/czan/honours

1 files changed, 653 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CacheTokens.cpp b/clang/lib/Frontend/CacheTokens.cpp
new file mode 100644
index 0000000..58a6b8d
--- /dev/null
+++ b/clang/lib/Frontend/CacheTokens.cpp
@@ -0,0 +1,653 @@
+//===--- CacheTokens.cpp - Caching of lexer tokens for PTH 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 PTH support for Clang that is
+// based on caching lexed tokens and identifiers.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Frontend/Utils.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/FileSystemStatCache.h"
+#include "clang/Basic/IdentifierTable.h"
+#include "clang/Basic/OnDiskHashTable.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Lex/Preprocessor.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Path.h"
+
+// FIXME: put this somewhere else?
+#ifndef S_ISDIR
+#define S_ISDIR(x) (((x)&_S_IFDIR)!=0)
+#endif
+
+using namespace clang;
+using namespace clang::io;
+
+//===----------------------------------------------------------------------===//
+// PTH-specific stuff.
+//===----------------------------------------------------------------------===//
+
+namespace {
+class PTHEntry {
+  Offset TokenData, PPCondData;
+
+public:
+  PTHEntry() {}
+
+  PTHEntry(Offset td, Offset ppcd)
+    : TokenData(td), PPCondData(ppcd) {}
+
+  Offset getTokenOffset() const { return TokenData; }
+  Offset getPPCondTableOffset() const { return PPCondData; }
+};
+
+
+class PTHEntryKeyVariant {
+  union { const FileEntry* FE; const char* Path; };
+  enum { IsFE = 0x1, IsDE = 0x2, IsNoExist = 0x0 } Kind;
+  struct stat *StatBuf;
+public:
+  PTHEntryKeyVariant(const FileEntry *fe)
+    : FE(fe), Kind(IsFE), StatBuf(0) {}
+
+  PTHEntryKeyVariant(struct stat* statbuf, const char* path)
+    : Path(path), Kind(IsDE), StatBuf(new struct stat(*statbuf)) {}
+
+  explicit PTHEntryKeyVariant(const char* path)
+    : Path(path), Kind(IsNoExist), StatBuf(0) {}
+
+  bool isFile() const { return Kind == IsFE; }
+
+  StringRef getString() const {
+    return Kind == IsFE ? FE->getName() : Path;
+  }
+
+  unsigned getKind() const { return (unsigned) Kind; }
+
+  void EmitData(raw_ostream& Out) {
+    switch (Kind) {
+    case IsFE:
+      // Emit stat information.
+      ::Emit32(Out, FE->getInode());
+      ::Emit32(Out, FE->getDevice());
+      ::Emit16(Out, FE->getFileMode());
+      ::Emit64(Out, FE->getModificationTime());
+      ::Emit64(Out, FE->getSize());
+      break;
+    case IsDE:
+      // Emit stat information.
+      ::Emit32(Out, (uint32_t) StatBuf->st_ino);
+      ::Emit32(Out, (uint32_t) StatBuf->st_dev);
+      ::Emit16(Out, (uint16_t) StatBuf->st_mode);
+      ::Emit64(Out, (uint64_t) StatBuf->st_mtime);
+      ::Emit64(Out, (uint64_t) StatBuf->st_size);
+      delete StatBuf;
+      break;
+    default:
+      break;
+    }
+  }
+
+  unsigned getRepresentationLength() const {
+    return Kind == IsNoExist ? 0 : 4 + 4 + 2 + 8 + 8;
+  }
+};
+
+class FileEntryPTHEntryInfo {
+public:
+  typedef PTHEntryKeyVariant key_type;
+  typedef key_type key_type_ref;
+
+  typedef PTHEntry data_type;
+  typedef const PTHEntry& data_type_ref;
+
+  static unsigned ComputeHash(PTHEntryKeyVariant V) {
+    return llvm::HashString(V.getString());
+  }
+
+  static std::pair<unsigned,unsigned>
+  EmitKeyDataLength(raw_ostream& Out, PTHEntryKeyVariant V,
+                    const PTHEntry& E) {
+
+    unsigned n = V.getString().size() + 1 + 1;
+    ::Emit16(Out, n);
+
+    unsigned m = V.getRepresentationLength() + (V.isFile() ? 4 + 4 : 0);
+    ::Emit8(Out, m);
+
+    return std::make_pair(n, m);
+  }
+
+  static void EmitKey(raw_ostream& Out, PTHEntryKeyVariant V, unsigned n){
+    // Emit the entry kind.
+    ::Emit8(Out, (unsigned) V.getKind());
+    // Emit the string.
+    Out.write(V.getString().data(), n - 1);
+  }
+
+  static void EmitData(raw_ostream& Out, PTHEntryKeyVariant V,
+                       const PTHEntry& E, unsigned) {
+
+
+    // For file entries emit the offsets into the PTH file for token data
+    // and the preprocessor blocks table.
+    if (V.isFile()) {
+      ::Emit32(Out, E.getTokenOffset());
+      ::Emit32(Out, E.getPPCondTableOffset());
+    }
+
+    // Emit any other data associated with the key (i.e., stat information).
+    V.EmitData(Out);
+  }
+};
+
+class OffsetOpt {
+  bool valid;
+  Offset off;
+public:
+  OffsetOpt() : valid(false) {}
+  bool hasOffset() const { return valid; }
+  Offset getOffset() const { assert(valid); return off; }
+  void setOffset(Offset o) { off = o; valid = true; }
+};
+} // end anonymous namespace
+
+typedef OnDiskChainedHashTableGenerator<FileEntryPTHEntryInfo> PTHMap;
+
+namespace {
+class PTHWriter {
+  typedef llvm::DenseMap<const IdentifierInfo*,uint32_t> IDMap;
+  typedef llvm::StringMap<OffsetOpt, llvm::BumpPtrAllocator> CachedStrsTy;
+
+  IDMap IM;
+  llvm::raw_fd_ostream& Out;
+  Preprocessor& PP;
+  uint32_t idcount;
+  PTHMap PM;
+  CachedStrsTy CachedStrs;
+  Offset CurStrOffset;
+  std::vector<llvm::StringMapEntry<OffsetOpt>*> StrEntries;
+
+  //// Get the persistent id for the given IdentifierInfo*.
+  uint32_t ResolveID(const IdentifierInfo* II);
+
+  /// Emit a token to the PTH file.
+  void EmitToken(const Token& T);
+
+  void Emit8(uint32_t V) { ::Emit8(Out, V); }
+
+  void Emit16(uint32_t V) { ::Emit16(Out, V); }
+
+  void Emit32(uint32_t V) { ::Emit32(Out, V); }
+
+  void EmitBuf(const char *Ptr, unsigned NumBytes) {
+    Out.write(Ptr, NumBytes);
+  }
+
+  void EmitString(StringRef V) {
+    ::Emit16(Out, V.size());
+    EmitBuf(V.data(), V.size());
+  }
+
+  /// EmitIdentifierTable - Emits two tables to the PTH file.  The first is
+  ///  a hashtable mapping from identifier strings to persistent IDs.
+  ///  The second is a straight table mapping from persistent IDs to string data
+  ///  (the keys of the first table).
+  std::pair<Offset, Offset> EmitIdentifierTable();
+
+  /// EmitFileTable - Emit a table mapping from file name strings to PTH
+  /// token data.
+  Offset EmitFileTable() { return PM.Emit(Out); }
+
+  PTHEntry LexTokens(Lexer& L);
+  Offset EmitCachedSpellings();
+
+public:
+  PTHWriter(llvm::raw_fd_ostream& out, Preprocessor& pp)
+    : Out(out), PP(pp), idcount(0), CurStrOffset(0) {}
+
+  PTHMap &getPM() { return PM; }
+  void GeneratePTH(const std::string &MainFile);
+};
+} // end anonymous namespace
+
+uint32_t PTHWriter::ResolveID(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())
+    return I->second; // We've already added 1.
+
+  IM[II] = ++idcount; // Pre-increment since '0' is reserved for NULL.
+  return idcount;
+}
+
+void PTHWriter::EmitToken(const Token& T) {
+  // Emit the token kind, flags, and length.
+  Emit32(((uint32_t) T.getKind()) | ((((uint32_t) T.getFlags())) << 8)|
+         (((uint32_t) T.getLength()) << 16));
+
+  if (!T.isLiteral()) {
+    Emit32(ResolveID(T.getIdentifierInfo()));
+  } else {
+    // We cache *un-cleaned* spellings. This gives us 100% fidelity with the
+    // source code.
+    StringRef s(T.getLiteralData(), T.getLength());
+
+    // Get the string entry.
+    llvm::StringMapEntry<OffsetOpt> *E = &CachedStrs.GetOrCreateValue(s);
+
+    // If this is a new string entry, bump the PTH offset.
+    if (!E->getValue().hasOffset()) {
+      E->getValue().setOffset(CurStrOffset);
+      StrEntries.push_back(E);
+      CurStrOffset += s.size() + 1;
+    }
+
+    // Emit the relative offset into the PTH file for the spelling string.
+    Emit32(E->getValue().getOffset());
+  }
+
+  // Emit the offset into the original source file of this token so that we
+  // can reconstruct its SourceLocation.
+  Emit32(PP.getSourceManager().getFileOffset(T.getLocation()));
+}
+
+PTHEntry PTHWriter::LexTokens(Lexer& L) {
+  // Pad 0's so that we emit tokens to a 4-byte alignment.
+  // This speed up reading them back in.
+  Pad(Out, 4);
+  Offset TokenOff = (Offset) Out.tell();
+
+  // 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);
+  NextToken:
+
+    if ((Tok.isAtStartOfLine() || Tok.is(tok::eof)) &&
+        ParsingPreprocessorDirective) {
+      // Insert an eod 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::eod);
+      Tmp.clearFlag(Token::StartOfLine);
+      Tmp.setIdentifierInfo(0);
+      EmitToken(Tmp);
+      ParsingPreprocessorDirective = false;
+    }
+
+    if (Tok.is(tok::raw_identifier)) {
+      PP.LookUpIdentifierInfo(Tok);
+      EmitToken(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();
+
+      // Get the next token.
+      Token NextTok;
+      L.LexFromRawLexer(NextTok);
+
+      // If we see the start of line, then we had a null directive "#".  In
+      // this case, discard both tokens.
+      if (NextTok.isAtStartOfLine())
+        goto NextToken;
+
+      // The token is the start of a directive.  Emit it.
+      EmitToken(Tok);
+      Tok = NextTok;
+
+      // Did we see 'include'/'import'/'include_next'?
+      if (Tok.isNot(tok::raw_identifier)) {
+        EmitToken(Tok);
+        continue;
+      }
+
+      IdentifierInfo* II = PP.LookUpIdentifierInfo(Tok);
+      tok::PPKeywordKind K = II->getPPKeywordID();
+
+      ParsingPreprocessorDirective = true;
+
+      switch (K) {
+      case tok::pp_not_keyword:
+        // Invalid directives "#foo" can occur in #if 0 blocks etc, just pass
+        // them through.
+      default:
+        break;
+
+      case tok::pp_include:
+      case tok::pp_import:
+      case tok::pp_include_next: {
+        // Save the 'include' token.
+        EmitToken(Tok);
+        // Lex the next token as an include string.
+        L.setParsingPreprocessorDirective(true);
+        L.LexIncludeFilename(Tok);
+        L.setParsingPreprocessorDirective(false);
+        assert(!Tok.isAtStartOfLine());
+        if (Tok.is(tok::raw_identifier))
+          PP.LookUpIdentifierInfo(Tok);
+
+        break;
+      }
+      case tok::pp_if:
+      case tok::pp_ifdef:
+      case tok::pp_ifndef: {
+        // Add 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));
+        EmitToken(Tok);
+
+        // Some files have gibberish on the same line as '#endif'.
+        // Discard these tokens.
+        do
+          L.LexFromRawLexer(Tok);
+        while (Tok.isNot(tok::eof) && !Tok.isAtStartOfLine());
+        // We have the next token in hand.
+        // Don't immediately lex the next one.
+        goto NextToken;
+      }
+      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;
+      }
+      }
+    }
+
+    EmitToken(Tok);
+  }
+  while (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(PPCond.size());
+
+  for (unsigned i = 0, e = PPCond.size(); i!=e; ++i) {
+    Emit32(PPCond[i].first - TokenOff);
+    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(x == i ? 0 : x);
+  }
+
+  return PTHEntry(TokenOff, PPCondOff);
+}
+
+Offset PTHWriter::EmitCachedSpellings() {
+  // Write each cached strings to the PTH file.
+  Offset SpellingsOff = Out.tell();
+
+  for (std::vector<llvm::StringMapEntry<OffsetOpt>*>::iterator
+       I = StrEntries.begin(), E = StrEntries.end(); I!=E; ++I)
+    EmitBuf((*I)->getKeyData(), (*I)->getKeyLength()+1 /*nul included*/);
+
+  return SpellingsOff;
+}
+
+void PTHWriter::GeneratePTH(const std::string &MainFile) {
+  // Generate the prologue.
+  Out << "cfe-pth";
+  Emit32(PTHManager::Version);
+
+  // Leave 4 words for the prologue.
+  Offset PrologueOffset = Out.tell();
+  for (unsigned i = 0; i < 4; ++i)
+    Emit32(0);
+
+  // Write the name of the MainFile.
+  if (!MainFile.empty()) {
+    EmitString(MainFile);
+  } else {
+    // String with 0 bytes.
+    Emit16(0);
+  }
+  Emit8(0);
+
+  // 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.getLangOpts();
+
+  for (SourceManager::fileinfo_iterator I = SM.fileinfo_begin(),
+       E = SM.fileinfo_end(); I != E; ++I) {
+    const SrcMgr::ContentCache &C = *I->second;
+    const FileEntry *FE = C.OrigEntry;
+
+    // FIXME: Handle files with non-absolute paths.
+    if (llvm::sys::path::is_relative(FE->getName()))
+      continue;
+
+    const llvm::MemoryBuffer *B = C.getBuffer(PP.getDiagnostics(), SM);
+    if (!B) continue;
+
+    FileID FID = SM.createFileID(FE, SourceLocation(), SrcMgr::C_User);
+    const llvm::MemoryBuffer *FromFile = SM.getBuffer(FID);
+    Lexer L(FID, FromFile, SM, LOpts);
+    PM.insert(FE, LexTokens(L));
+  }
+
+  // Write out the identifier table.
+  const std::pair<Offset,Offset> &IdTableOff = EmitIdentifierTable();
+
+  // Write out the cached strings table.
+  Offset SpellingOff = EmitCachedSpellings();
+
+  // Write out the file table.
+  Offset FileTableOff = EmitFileTable();
+
+  // Finally, write the prologue.
+  Out.seek(PrologueOffset);
+  Emit32(IdTableOff.first);
+  Emit32(IdTableOff.second);
+  Emit32(FileTableOff);
+  Emit32(SpellingOff);
+}
+
+namespace {
+/// StatListener - A simple "interpose" object used to monitor stat calls
+/// invoked by FileManager while processing the original sources used
+/// as input to PTH generation.  StatListener populates the PTHWriter's
+/// file map with stat information for directories as well as negative stats.
+/// Stat information for files are populated elsewhere.
+class StatListener : public FileSystemStatCache {
+  PTHMap &PM;
+public:
+  StatListener(PTHMap &pm) : PM(pm) {}
+  ~StatListener() {}
+
+  LookupResult getStat(const char *Path, struct stat &StatBuf,
+                       int *FileDescriptor) {
+    LookupResult Result = statChained(Path, StatBuf, FileDescriptor);
+
+    if (Result == CacheMissing) // Failed 'stat'.
+      PM.insert(PTHEntryKeyVariant(Path), PTHEntry());
+    else if (S_ISDIR(StatBuf.st_mode)) {
+      // Only cache directories with absolute paths.
+      if (llvm::sys::path::is_relative(Path))
+        return Result;
+
+      PM.insert(PTHEntryKeyVariant(&StatBuf, Path), PTHEntry());
+    }
+
+    return Result;
+  }
+};
+} // end anonymous namespace
+
+
+void clang::CacheTokens(Preprocessor &PP, llvm::raw_fd_ostream* OS) {
+  // Get the name of the main file.
+  const SourceManager &SrcMgr = PP.getSourceManager();
+  const FileEntry *MainFile = SrcMgr.getFileEntryForID(SrcMgr.getMainFileID());
+  SmallString<128> MainFilePath(MainFile->getName());
+
+  llvm::sys::fs::make_absolute(MainFilePath);
+
+  // Create the PTHWriter.
+  PTHWriter PW(*OS, PP);
+
+  // Install the 'stat' system call listener in the FileManager.
+  StatListener *StatCache = new StatListener(PW.getPM());
+  PP.getFileManager().addStatCache(StatCache, /*AtBeginning=*/true);
+
+  // 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));
+
+  // Generate the PTH file.
+  PP.getFileManager().removeStatCache(StatCache);
+  PW.GeneratePTH(MainFilePath.str());
+}
+
+//===----------------------------------------------------------------------===//
+
+namespace {
+class PTHIdKey {
+public:
+  const IdentifierInfo* II;
+  uint32_t FileOffset;
+};
+
+class PTHIdentifierTableTrait {
+public:
+  typedef PTHIdKey* key_type;
+  typedef key_type  key_type_ref;
+
+  typedef uint32_t  data_type;
+  typedef data_type data_type_ref;
+
+  static unsigned ComputeHash(PTHIdKey* key) {
+    return llvm::HashString(key->II->getName());
+  }
+
+  static std::pair<unsigned,unsigned>
+  EmitKeyDataLength(raw_ostream& Out, const PTHIdKey* key, uint32_t) {
+    unsigned n = key->II->getLength() + 1;
+    ::Emit16(Out, n);
+    return std::make_pair(n, sizeof(uint32_t));
+  }
+
+  static void EmitKey(raw_ostream& Out, PTHIdKey* key, unsigned n) {
+    // Record the location of the key data.  This is used when generating
+    // the mapping from persistent IDs to strings.
+    key->FileOffset = Out.tell();
+    Out.write(key->II->getNameStart(), n);
+  }
+
+  static void EmitData(raw_ostream& Out, PTHIdKey*, uint32_t pID,
+                       unsigned) {
+    ::Emit32(Out, pID);
+  }
+};
+} // end anonymous namespace
+
+/// EmitIdentifierTable - Emits two tables to the PTH file.  The first is
+///  a hashtable mapping from identifier strings to persistent IDs.  The second
+///  is a straight table mapping from persistent IDs to string data (the
+///  keys of the first table).
+///
+std::pair<Offset,Offset> PTHWriter::EmitIdentifierTable() {
+  // Build two maps:
+  //  (1) an inverse map from persistent IDs -> (IdentifierInfo*,Offset)
+  //  (2) a map from (IdentifierInfo*, Offset)* -> persistent IDs
+
+  // Note that we use 'calloc', so all the bytes are 0.
+  PTHIdKey *IIDMap = (PTHIdKey*)calloc(idcount, sizeof(PTHIdKey));
+
+  // Create the hashtable.
+  OnDiskChainedHashTableGenerator<PTHIdentifierTableTrait> IIOffMap;
+
+  // Generate mapping from persistent IDs -> IdentifierInfo*.
+  for (IDMap::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 < idcount);
+    unsigned idx = I->second-1;
+
+    // Store the mapping from persistent ID to IdentifierInfo*
+    IIDMap[idx].II = I->first;
+
+    // Store the reverse mapping in a hashtable.
+    IIOffMap.insert(&IIDMap[idx], I->second);
+  }
+
+  // Write out the inverse map first.  This causes the PCIDKey entries to
+  // record PTH file offsets for the string data.  This is used to write
+  // the second table.
+  Offset StringTableOffset = IIOffMap.Emit(Out);
+
+  // Now emit the table mapping from persistent IDs to PTH file offsets.
+  Offset IDOff = Out.tell();
+  Emit32(idcount);  // Emit the number of identifiers.
+  for (unsigned i = 0 ; i < idcount; ++i)
+    Emit32(IIDMap[i].FileOffset);
+
+  // Finally, release the inverse map.
+  free(IIDMap);
+
+  return std::make_pair(IDOff, StringTableOffset);
+}