text: //===--- raw_ostream.h - Raw output stream ----------------------*- C++ -*-===//
  //
  //                     The LLVM Compiler Infrastructure
  //
  // This file is distributed under the University of Illinois Open Source
  // License. See LICENSE.TXT for details.
  //
  //===----------------------------------------------------------------------===//
  //
  //  This file defines the raw_ostream class.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_SUPPORT_RAW_OSTREAM_H
  #define LLVM_SUPPORT_RAW_OSTREAM_H
  
  #include "llvm/ADT/StringRef.h"
  #include "llvm/Support/Compiler.h"
  #include "llvm/Support/DataTypes.h"
  #include <system_error>
  //---OPENCOR--- BEGIN
  #include "llvmglobal.h"
  //---OPENCOR--- END
  
  namespace llvm {
    class format_object_base;
    class FormattedString;
    class FormattedNumber;
    template <typename T>
    class SmallVectorImpl;
  
    namespace sys {
      namespace fs {
        enum OpenFlags : unsigned;
      }
    }
  
  /// raw_ostream - This class implements an extremely fast bulk output stream
  /// that can *only* output to a stream.  It does not support seeking, reopening,
  /// rewinding, line buffered disciplines etc. It is a simple buffer that outputs
  /// a chunk at a time.
  class raw_ostream {
  private:
    void operator=(const raw_ostream &) LLVM_DELETED_FUNCTION;
    raw_ostream(const raw_ostream &) LLVM_DELETED_FUNCTION;
  
    /// The buffer is handled in such a way that the buffer is
    /// uninitialized, unbuffered, or out of space when OutBufCur >=
    /// OutBufEnd. Thus a single comparison suffices to determine if we
    /// need to take the slow path to write a single character.
    ///
    /// The buffer is in one of three states:
    ///  1. Unbuffered (BufferMode == Unbuffered)
    ///  1. Uninitialized (BufferMode != Unbuffered && OutBufStart == 0).
    ///  2. Buffered (BufferMode != Unbuffered && OutBufStart != 0 &&
    ///               OutBufEnd - OutBufStart >= 1).
    ///
    /// If buffered, then the raw_ostream owns the buffer if (BufferMode ==
    /// InternalBuffer); otherwise the buffer has been set via SetBuffer and is
    /// managed by the subclass.
    ///
    /// If a subclass installs an external buffer using SetBuffer then it can wait
    /// for a \see write_impl() call to handle the data which has been put into
    /// this buffer.
    char *OutBufStart, *OutBufEnd, *OutBufCur;
  
    enum BufferKind {
      Unbuffered = 0,
      InternalBuffer,
      ExternalBuffer
    } BufferMode;
  
  public:
    // color order matches ANSI escape sequence, don't change
    enum Colors {
      BLACK=0,
      RED,
      GREEN,
      YELLOW,
      BLUE,
      MAGENTA,
      CYAN,
      WHITE,
      SAVEDCOLOR
    };
  
    explicit raw_ostream(bool unbuffered=false)
      : BufferMode(unbuffered ? Unbuffered : InternalBuffer) {
      // Start out ready to flush.
      OutBufStart = OutBufEnd = OutBufCur = nullptr;
    }
  
    virtual ~raw_ostream();
  
    /// tell - Return the current offset with the file.
    uint64_t tell() const { return current_pos() + GetNumBytesInBuffer(); }
  
    //===--------------------------------------------------------------------===//
    // Configuration Interface
    //===--------------------------------------------------------------------===//
  
    /// SetBuffered - Set the stream to be buffered, with an automatically
    /// determined buffer size.
    void SetBuffered();
  
    /// SetBufferSize - Set the stream to be buffered, using the
    /// specified buffer size.
    void SetBufferSize(size_t Size) {
      flush();
      SetBufferAndMode(new char[Size], Size, InternalBuffer);
    }
  
    size_t GetBufferSize() const {
      // If we're supposed to be buffered but haven't actually gotten around
      // to allocating the buffer yet, return the value that would be used.
      if (BufferMode != Unbuffered && OutBufStart == nullptr)
        return preferred_buffer_size();
  
      // Otherwise just return the size of the allocated buffer.
      return OutBufEnd - OutBufStart;
    }
  
    /// SetUnbuffered - Set the stream to be unbuffered. When
    /// unbuffered, the stream will flush after every write. This routine
    /// will also flush the buffer immediately when the stream is being
    /// set to unbuffered.
    void SetUnbuffered() {
      flush();
      SetBufferAndMode(nullptr, 0, Unbuffered);
    }
  
    size_t GetNumBytesInBuffer() const {
      return OutBufCur - OutBufStart;
    }
  
    //===--------------------------------------------------------------------===//
    // Data Output Interface
    //===--------------------------------------------------------------------===//
  
    void flush() {
      if (OutBufCur != OutBufStart)
        flush_nonempty();
    }
  
    raw_ostream &operator<<(char C) {
      if (OutBufCur >= OutBufEnd)
        return write(C);
      *OutBufCur++ = C;
      return *this;
    }
  
    raw_ostream &operator<<(unsigned char C) {
      if (OutBufCur >= OutBufEnd)
        return write(C);
      *OutBufCur++ = C;
      return *this;
    }
  
    raw_ostream &operator<<(signed char C) {
      if (OutBufCur >= OutBufEnd)
        return write(C);
      *OutBufCur++ = C;
      return *this;
    }
  
    raw_ostream &operator<<(StringRef Str) {
      // Inline fast path, particularly for strings with a known length.
      size_t Size = Str.size();
  
      // Make sure we can use the fast path.
      if (Size > (size_t)(OutBufEnd - OutBufCur))
        return write(Str.data(), Size);
  
      memcpy(OutBufCur, Str.data(), Size);
      OutBufCur += Size;
      return *this;
    }
  
    raw_ostream &operator<<(const char *Str) {
      // Inline fast path, particularly for constant strings where a sufficiently
      // smart compiler will simplify strlen.
  
      return this->operator<<(StringRef(Str));
    }
  
    raw_ostream &operator<<(const std::string &Str) {
      // Avoid the fast path, it would only increase code size for a marginal win.
      return write(Str.data(), Str.length());
    }
  
    raw_ostream &operator<<(unsigned long N);
    raw_ostream &operator<<(long N);
    raw_ostream &operator<<(unsigned long long N);
    raw_ostream &operator<<(long long N);
    raw_ostream &operator<<(const void *P);
    raw_ostream &operator<<(unsigned int N) {
      return this->operator<<(static_cast<unsigned long>(N));
    }
  
    raw_ostream &operator<<(int N) {
      return this->operator<<(static_cast<long>(N));
    }
  
    raw_ostream &operator<<(double N);
  
    /// write_hex - Output \p N in hexadecimal, without any prefix or padding.
    raw_ostream &write_hex(unsigned long long N);
  
    /// write_escaped - Output \p Str, turning '\\', '\t', '\n', '"', and
    /// anything that doesn't satisfy std::isprint into an escape sequence.
    raw_ostream &write_escaped(StringRef Str, bool UseHexEscapes = false);
  
    raw_ostream &write(unsigned char C);
    raw_ostream &write(const char *Ptr, size_t Size);
  
    // Formatted output, see the format() function in Support/Format.h.
    raw_ostream &operator<<(const format_object_base &Fmt);
  
    // Formatted output, see the leftJustify() function in Support/Format.h.
    raw_ostream &operator<<(const FormattedString &);
  
    // Formatted output, see the formatHex() function in Support/Format.h.
    raw_ostream &operator<<(const FormattedNumber &);
  
    /// indent - Insert 'NumSpaces' spaces.
    raw_ostream &indent(unsigned NumSpaces);
  
  
    /// Changes the foreground color of text that will be output from this point
    /// forward.
    /// @param Color ANSI color to use, the special SAVEDCOLOR can be used to
    /// change only the bold attribute, and keep colors untouched
    /// @param Bold bold/brighter text, default false
    /// @param BG if true change the background, default: change foreground
    /// @returns itself so it can be used within << invocations
    virtual raw_ostream &changeColor(enum Colors Color,
                                     bool Bold = false,
                                     bool BG = false) {
      (void)Color;
      (void)Bold;
      (void)BG;
      return *this;
    }
  
    /// Resets the colors to terminal defaults. Call this when you are done
    /// outputting colored text, or before program exit.
    virtual raw_ostream &resetColor() { return *this; }
  
    /// Reverses the forground and background colors.
    virtual raw_ostream &reverseColor() { return *this; }
  
    /// This function determines if this stream is connected to a "tty" or
    /// "console" window. That is, the output would be displayed to the user
    /// rather than being put on a pipe or stored in a file.
    virtual bool is_displayed() const { return false; }
  
    /// This function determines if this stream is displayed and supports colors.
    virtual bool has_colors() const { return is_displayed(); }
  
    //===--------------------------------------------------------------------===//
    // Subclass Interface
    //===--------------------------------------------------------------------===//
  
  private:
    /// write_impl - The is the piece of the class that is implemented
    /// by subclasses.  This writes the \p Size bytes starting at
    /// \p Ptr to the underlying stream.
    ///
    /// This function is guaranteed to only be called at a point at which it is
    /// safe for the subclass to install a new buffer via SetBuffer.
    ///
    /// \param Ptr The start of the data to be written. For buffered streams this
    /// is guaranteed to be the start of the buffer.
    ///
    /// \param Size The number of bytes to be written.
    ///
    /// \invariant { Size > 0 }
    virtual void write_impl(const char *Ptr, size_t Size) = 0;
  
    // An out of line virtual method to provide a home for the class vtable.
    virtual void handle();
  
    /// current_pos - Return the current position within the stream, not
    /// counting the bytes currently in the buffer.
    virtual uint64_t current_pos() const = 0;
  
  protected:
    /// SetBuffer - Use the provided buffer as the raw_ostream buffer. This is
    /// intended for use only by subclasses which can arrange for the output to go
    /// directly into the desired output buffer, instead of being copied on each
    /// flush.
    void SetBuffer(char *BufferStart, size_t Size) {
      SetBufferAndMode(BufferStart, Size, ExternalBuffer);
    }
  
    /// preferred_buffer_size - Return an efficient buffer size for the
    /// underlying output mechanism.
    virtual size_t preferred_buffer_size() const;
  
    /// getBufferStart - Return the beginning of the current stream buffer, or 0
    /// if the stream is unbuffered.
    const char *getBufferStart() const { return OutBufStart; }
  
    //===--------------------------------------------------------------------===//
    // Private Interface
    //===--------------------------------------------------------------------===//
  private:
    /// SetBufferAndMode - Install the given buffer and mode.
    void SetBufferAndMode(char *BufferStart, size_t Size, BufferKind Mode);
  
    /// flush_nonempty - Flush the current buffer, which is known to be
    /// non-empty. This outputs the currently buffered data and resets
    /// the buffer to empty.
    void flush_nonempty();
  
    /// copy_to_buffer - Copy data into the buffer. Size must not be
    /// greater than the number of unused bytes in the buffer.
    void copy_to_buffer(const char *Ptr, size_t Size);
  };
  
  //===----------------------------------------------------------------------===//
  // File Output Streams
  //===----------------------------------------------------------------------===//
  
  /// raw_fd_ostream - A raw_ostream that writes to a file descriptor.
  ///
  class raw_fd_ostream : public raw_ostream {
    int FD;
    bool ShouldClose;
  
    /// Error This flag is true if an error of any kind has been detected.
    ///
    bool Error;
  
    /// Controls whether the stream should attempt to use atomic writes, when
    /// possible.
    bool UseAtomicWrites;
  
    uint64_t pos;
  
    /// write_impl - See raw_ostream::write_impl.
    void write_impl(const char *Ptr, size_t Size) override;
  
    /// current_pos - Return the current position within the stream, not
    /// counting the bytes currently in the buffer.
    uint64_t current_pos() const override { return pos; }
  
    /// preferred_buffer_size - Determine an efficient buffer size.
    size_t preferred_buffer_size() const override;
  
    /// error_detected - Set the flag indicating that an output error has
    /// been encountered.
    void error_detected() { Error = true; }
  
  public:
    /// Open the specified file for writing. If an error occurs, information
    /// about the error is put into EC, and the stream should be immediately
    /// destroyed;
    /// \p Flags allows optional flags to control how the file will be opened.
    ///
    /// As a special case, if Filename is "-", then the stream will use
    /// STDOUT_FILENO instead of opening a file. Note that it will still consider
    /// itself to own the file descriptor. In particular, it will close the
    /// file descriptor when it is done (this is necessary to detect
    /// output errors).
    raw_fd_ostream(StringRef Filename, std::error_code &EC,
                   sys::fs::OpenFlags Flags);
  
    /// raw_fd_ostream ctor - FD is the file descriptor that this writes to.  If
    /// ShouldClose is true, this closes the file when the stream is destroyed.
    raw_fd_ostream(int fd, bool shouldClose, bool unbuffered=false);
  
    ~raw_fd_ostream();
  
    /// close - Manually flush the stream and close the file.
    /// Note that this does not call fsync.
    void close();
  
    /// seek - Flushes the stream and repositions the underlying file descriptor
    /// position to the offset specified from the beginning of the file.
    uint64_t seek(uint64_t off);
  
    /// SetUseAtomicWrite - Set the stream to attempt to use atomic writes for
    /// individual output routines where possible.
    ///
    /// Note that because raw_ostream's are typically buffered, this flag is only
    /// sensible when used on unbuffered streams which will flush their output
    /// immediately.
    void SetUseAtomicWrites(bool Value) {
      UseAtomicWrites = Value;
    }
  
    raw_ostream &changeColor(enum Colors colors, bool bold=false,
                             bool bg=false) override;
    raw_ostream &resetColor() override;
  
    raw_ostream &reverseColor() override;
  
    bool is_displayed() const override;
  
    bool has_colors() const override;
  
    /// has_error - Return the value of the flag in this raw_fd_ostream indicating
    /// whether an output error has been encountered.
    /// This doesn't implicitly flush any pending output.  Also, it doesn't
    /// guarantee to detect all errors unless the stream has been closed.
    bool has_error() const {
      return Error;
    }
  
    /// clear_error - Set the flag read by has_error() to false. If the error
    /// flag is set at the time when this raw_ostream's destructor is called,
    /// report_fatal_error is called to report the error. Use clear_error()
    /// after handling the error to avoid this behavior.
    ///
    ///   "Errors should never pass silently.
    ///    Unless explicitly silenced."
    ///      - from The Zen of Python, by Tim Peters
    ///
    void clear_error() {
      Error = false;
    }
  };
  
  /// outs() - This returns a reference to a raw_ostream for standard output.
  /// Use it like: outs() << "foo" << "bar";
  /*---OPENCOR---
  raw_ostream &outs();
  */
  //---OPENCOR--- BEGIN
  raw_ostream LLVM_EXPORT &outs();
  //---OPENCOR--- END
  
  /// errs() - This returns a reference to a raw_ostream for standard error.
  /// Use it like: errs() << "foo" << "bar";
  raw_ostream &errs();
  
  /// nulls() - This returns a reference to a raw_ostream which simply discards
  /// output.
  /*---OPENCOR---
  raw_ostream &nulls();
  */
  //---OPENCOR--- BEGIN
  raw_ostream LLVM_EXPORT &nulls();
  //---OPENCOR--- END
  
  //===----------------------------------------------------------------------===//
  // Output Stream Adaptors
  //===----------------------------------------------------------------------===//
  
  /// raw_string_ostream - A raw_ostream that writes to an std::string.  This is a
  /// simple adaptor class. This class does not encounter output errors.
  class raw_string_ostream : public raw_ostream {
    std::string &OS;
  
    /// write_impl - See raw_ostream::write_impl.
    void write_impl(const char *Ptr, size_t Size) override;
  
    /// current_pos - Return the current position within the stream, not
    /// counting the bytes currently in the buffer.
    uint64_t current_pos() const override { return OS.size(); }
  public:
    explicit raw_string_ostream(std::string &O) : OS(O) {}
    ~raw_string_ostream();
  
    /// str - Flushes the stream contents to the target string and returns
    ///  the string's reference.
    std::string& str() {
      flush();
      return OS;
    }
  };
  
  /// raw_svector_ostream - A raw_ostream that writes to an SmallVector or
  /// SmallString.  This is a simple adaptor class. This class does not
  /// encounter output errors.
  class raw_svector_ostream : public raw_ostream {
    SmallVectorImpl<char> &OS;
  
    /// write_impl - See raw_ostream::write_impl.
    void write_impl(const char *Ptr, size_t Size) override;
  
    /// current_pos - Return the current position within the stream, not
    /// counting the bytes currently in the buffer.
    uint64_t current_pos() const override;
  public:
    /// Construct a new raw_svector_ostream.
    ///
    /// \param O The vector to write to; this should generally have at least 128
    /// bytes free to avoid any extraneous memory overhead.
    explicit raw_svector_ostream(SmallVectorImpl<char> &O);
    ~raw_svector_ostream();
  
    /// resync - This is called when the SmallVector we're appending to is changed
    /// outside of the raw_svector_ostream's control.  It is only safe to do this
    /// if the raw_svector_ostream has previously been flushed.
    void resync();
  
    /// str - Flushes the stream contents to the target vector and return a
    /// StringRef for the vector contents.
    StringRef str();
  };
  
  /// raw_null_ostream - A raw_ostream that discards all output.
  class raw_null_ostream : public raw_ostream {
    /// write_impl - See raw_ostream::write_impl.
    void write_impl(const char *Ptr, size_t size) override;
  
    /// current_pos - Return the current position within the stream, not
    /// counting the bytes currently in the buffer.
    uint64_t current_pos() const override;
  
  public:
    explicit raw_null_ostream() {}
    ~raw_null_ostream();
  };
  
  } // end llvm namespace
  
  #endif
  