C++ raw_ostream::write方法代码示例

void writeSymbol(const Symbol &Sym, const StringTableOut &Strings,
                 llvm::raw_ostream &OS) {
  OS << Sym.ID.raw(); // TODO: once we start writing xrefs and posting lists,
                      // symbol IDs should probably be in a string table.
  OS.write(static_cast<uint8_t>(Sym.SymInfo.Kind));
  OS.write(static_cast<uint8_t>(Sym.SymInfo.Lang));
  writeVar(Strings.index(Sym.Name), OS);
  writeVar(Strings.index(Sym.Scope), OS);
  writeVar(Strings.index(Sym.TemplateSpecializationArgs), OS);
  writeLocation(Sym.Definition, Strings, OS);
  writeLocation(Sym.CanonicalDeclaration, Strings, OS);
  writeVar(Sym.References, OS);
  OS.write(static_cast<uint8_t>(Sym.Flags));
  OS.write(static_cast<uint8_t>(Sym.Origin));
  writeVar(Strings.index(Sym.Signature), OS);
  writeVar(Strings.index(Sym.CompletionSnippetSuffix), OS);
  writeVar(Strings.index(Sym.Documentation), OS);
  writeVar(Strings.index(Sym.ReturnType), OS);
  writeVar(Strings.index(Sym.Type), OS);

  auto WriteInclude = [&](const Symbol::IncludeHeaderWithReferences &Include) {
    writeVar(Strings.index(Include.IncludeHeader), OS);
    writeVar(Include.References, OS);
  };
  writeVar(Sym.IncludeHeaders.size(), OS);
  for (const auto &Include : Sym.IncludeHeaders)
    WriteInclude(Include);
}

/// \brief Format the given diagnostic text and place the result in the given
/// buffer.
static void formatDiagnosticText(StringRef InText, 
                                 ArrayRef<DiagnosticArgument> Args,
                                 llvm::raw_ostream &Out) {
  while (!InText.empty()) {
    size_t Percent = InText.find('%');
    if (Percent == StringRef::npos) {
      // Write the rest of the string; we're done.
      Out.write(InText.data(), InText.size());
      break;
    }
    
    // Write the string up to (but not including) the %, then drop that text
    // (including the %).
    Out.write(InText.data(), Percent);
    InText = InText.substr(Percent + 1);
    
    // '%%' -> '%'.
    if (InText[0] == '%') {
      Out.write('%');
      InText = InText.substr(1);
      continue;
    }

    // Parse an optional modifier.
    StringRef Modifier;
    {
      unsigned Length = 0;
      while (isalpha(InText[Length]))
        ++Length;
      Modifier = InText.substr(0, Length);
      InText = InText.substr(Length);
    }
    
    // Parse the optional argument list for a modifier, which is brace-enclosed.
    StringRef ModifierArguments;
    if (InText[0] == '{') {
      InText = InText.substr(1);
      ModifierArguments = skipToDelimiter(InText, '}');
    }
    
    // Find the digit sequence.
    unsigned Length = 0;
    for (size_t N = InText.size(); Length != N; ++Length) {
      if (!isdigit(InText[Length]))
        break;
    }
      
    // Parse the digit sequence into an argument index.
    unsigned ArgIndex;      
    bool Result = InText.substr(0, Length).getAsInteger(10, ArgIndex);
    assert(!Result && "Unparseable argument index value?");
    (void)Result;
    assert(ArgIndex < Args.size() && "Out-of-range argument index");
    InText = InText.substr(Length);

    // Convert the argument to a string.
    formatDiagnosticArgument(Modifier, ModifierArguments, Args, ArgIndex, Out);
  }
}

void writeRefs(const SymbolID &ID, llvm::ArrayRef<Ref> Refs,
               const StringTableOut &Strings, llvm::raw_ostream &OS) {
  OS << ID.raw();
  writeVar(Refs.size(), OS);
  for (const auto &Ref : Refs) {
    OS.write(static_cast<unsigned char>(Ref.Kind));
    writeLocation(Ref.Location, Strings, OS);
  }
}

void writeIncludeGraphNode(const IncludeGraphNode &IGN,
                           const StringTableOut &Strings,
                           llvm::raw_ostream &OS) {
  OS.write(IGN.IsTU);
  writeVar(Strings.index(IGN.URI), OS);
  llvm::StringRef Hash(reinterpret_cast<const char *>(IGN.Digest.data()),
                       IGN.Digest.size());
  OS << Hash;
  writeVar(IGN.DirectIncludes.size(), OS);
  for (llvm::StringRef Include : IGN.DirectIncludes)
    writeVar(Strings.index(Include), OS);
}

bool ASTUnit::serialize(llvm::raw_ostream &OS) {
  if (getDiagnostics().hasErrorOccurred())
    return true;

  SmallString<128> Buffer;
  llvm::BitstreamWriter Stream(Buffer);
  ASTWriter Writer(Stream);
  Writer.WriteAST(getSema(), 0, std::string(), 0);

  // Write the generated bitstream to "Out".
  if (!Buffer.empty())
    OS.write((char *)&Buffer.front(), Buffer.size());

  return false;
}

/// Writes the code completion results from the sink for \p V to \p out.
///
/// The high-level format is:
///
///   HEADER
///     * version, which **must be bumped** if we change the format!
///     * mtime for the module file
///
///   KEY
///     * the original CodeCompletionCache::Key, used for debugging the cache.
///
///   RESULTS
///     * A length-prefixed array of fixed size CodeCompletionResults.
///     * Contains offsets into CHUNKS and STRINGS.
///
///   CHUNKS
///     * A length-prefixed array of CodeCompletionStrings.
///     * Each CodeCompletionString is a length-prefixed array of fixed size
///       CodeCompletionString::Chunks.
///
///   STRINGS
///     * A blob of length-prefixed strings referred to in CHUNKS or RESULTS.
static void writeCachedModule(llvm::raw_ostream &out,
                              const CodeCompletionCache::Key &K,
                              CodeCompletionCache::Value &V) {
  using namespace llvm::support;
  endian::Writer LE(out, little);

  // HEADER
  // Metadata required for reading the completions.
  LE.write(onDiskCompletionCacheVersion);           // Version
  auto mtime = V.ModuleModificationTime.time_since_epoch().count();
  LE.write(mtime);                                  // Mtime for module file

  // KEY
  // We don't need the stored key to load the results, but it is useful if we
  // want to debug the cache itself.
  {
    SmallString<256> scratch;
    llvm::raw_svector_ostream OSS(scratch);
    OSS << K.ModuleFilename << "\0";
    OSS << K.ModuleName << "\0";
    endian::Writer OSSLE(OSS, little);
    OSSLE.write(K.AccessPath.size());
    for (StringRef p : K.AccessPath)
      OSS << p << "\0";
    OSSLE.write(K.ResultsHaveLeadingDot);
    OSSLE.write(K.ForTestableLookup);
    OSSLE.write(K.ForPrivateImportLookup);
    OSSLE.write(K.CodeCompleteInitsInPostfixExpr);
    LE.write(static_cast<uint32_t>(OSS.tell()));   // Size of debug info
    out.write(OSS.str().data(), OSS.str().size()); // Debug info blob
  }

  // String streams for writing to the CHUNKS and STRINGS sections.
  std::string results_;
  llvm::raw_string_ostream results(results_);
  std::string chunks_;
  llvm::raw_string_ostream chunks(chunks_);
  endian::Writer chunksLE(chunks, little);
  std::string strings_;
  llvm::raw_string_ostream strings(strings_);

  auto addString = [&strings](StringRef str) {
    if (str.empty())
      return ~0u;
    auto size = strings.tell();
    endian::Writer LE(strings, little);
    LE.write(static_cast<uint32_t>(str.size()));
    strings << str;
    return static_cast<uint32_t>(size);
  };

  auto addCompletionString = [&](const CodeCompletionString *str) {
    auto size = chunks.tell();
    chunksLE.write(static_cast<uint32_t>(str->getChunks().size()));
    for (auto chunk : str->getChunks()) {
      chunksLE.write(static_cast<uint8_t>(chunk.getKind()));
      chunksLE.write(static_cast<uint8_t>(chunk.getNestingLevel()));
      chunksLE.write(static_cast<uint8_t>(chunk.isAnnotation()));
      if (chunk.hasText()) {
        chunksLE.write(addString(chunk.getText()));
      } else {
        chunksLE.write(static_cast<uint32_t>(~0u));
      }
    }
    return static_cast<uint32_t>(size);
  };

  // RESULTS
  {
    endian::Writer LE(results, little);
    for (CodeCompletionResult *R : V.Sink.Results) {
      // FIXME: compress bitfield
      LE.write(static_cast<uint8_t>(R->getKind()));
      if (R->getKind() == CodeCompletionResult::Declaration)
        LE.write(static_cast<uint8_t>(R->getAssociatedDeclKind()));
      else
        LE.write(~static_cast<uint8_t>(0u));
      if (R->isOperator())
//.........这里部分代码省略.........

/// \brief Print the given string to a stream, word-wrapping it to
/// some number of columns in the process.
///
/// \brief OS the stream to which the word-wrapping string will be
/// emitted.
///
/// \brief Str the string to word-wrap and output.
///
/// \brief Columns the number of columns to word-wrap to.
///
/// \brief Column the column number at which the first character of \p
/// Str will be printed. This will be non-zero when part of the first
/// line has already been printed.
///
/// \brief Indentation the number of spaces to indent any lines beyond
/// the first line.
///
/// \returns true if word-wrapping was required, or false if the
/// string fit on the first line.
static bool PrintWordWrapped(llvm::raw_ostream &OS,
                             const llvm::SmallVectorImpl<char> &Str,
                             unsigned Columns,
                             unsigned Column = 0,
                             unsigned Indentation = WordWrapIndentation) {
  unsigned Length = Str.size();

  // If there is a newline in this message somewhere, find that
  // newline and split the message into the part before the newline
  // (which will be word-wrapped) and the part from the newline one
  // (which will be emitted unchanged).
  for (unsigned I = 0; I != Length; ++I)
    if (Str[I] == '\n') {
      Length = I;
      break;
    }

  // The string used to indent each line.
  llvm::SmallString<16> IndentStr;
  IndentStr.assign(Indentation, ' ');
  bool Wrapped = false;
  for (unsigned WordStart = 0, WordEnd; WordStart < Length;
       WordStart = WordEnd) {
    // Find the beginning of the next word.
    WordStart = skipWhitespace(WordStart, Str, Length);
    if (WordStart == Length)
      break;

    // Find the end of this word.
    WordEnd = findEndOfWord(WordStart, Str, Length, Column, Columns);

    // Does this word fit on the current line?
    unsigned WordLength = WordEnd - WordStart;
    if (Column + WordLength < Columns) {
      // This word fits on the current line; print it there.
      if (WordStart) {
        OS << ' ';
        Column += 1;
      }
      OS.write(&Str[WordStart], WordLength);
      Column += WordLength;
      continue;
    }

    // This word does not fit on the current line, so wrap to the next
    // line.
    OS << '\n';
    OS.write(&IndentStr[0], Indentation);
    OS.write(&Str[WordStart], WordLength);
    Column = Indentation + WordLength;
    Wrapped = true;
  }

  if (Length == Str.size())
    return Wrapped; // We're done.

  // There is a newline in the message, followed by something that
  // will not be word-wrapped. Print that.
  OS.write(&Str[Length], Str.size() - Length);
  return true;
}

static void WriteString(llvm::raw_ostream &OS, llvm::StringRef String) {
  WriteUnsigned(OS, String.size());
  OS.write(String.data(), String.size());
}

static void WriteUnsigned(llvm::raw_ostream &OS, unsigned Value) {
  OS.write((const char *)&Value, sizeof(unsigned));
}

/// Finish the mangling of the symbol and write the mangled name into
/// \p stream.
void Mangler::finalize(llvm::raw_ostream &stream) {
  std::string result = finalize();
  stream.write(result.data(), result.size());
}