llvm-6502/include/llvm/Support/FormattedStream.h
Daniel Dunbar b759865495 Revert "Don't allow formatted_ostream to be unbuffered, even if its underlying
buffer", while we work out a solution.

Dan convinced me that making debugging annoying for him is worse than 10x being
slower for me. :)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82553 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-22 16:33:42 +00:00

151 lines
4.8 KiB
C++

//===-- llvm/CodeGen/FormattedStream.h - Formatted streams ------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains raw_ostream implementations for streams to do
// things like pretty-print comments.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_FORMATTEDSTREAM_H
#define LLVM_SUPPORT_FORMATTEDSTREAM_H
#include "llvm/Support/raw_ostream.h"
namespace llvm
{
/// formatted_raw_ostream - Formatted raw_fd_ostream to handle
/// asm-specific constructs.
///
class formatted_raw_ostream : public raw_ostream {
public:
/// DELETE_STREAM - Tell the destructor to delete the held stream.
///
static const bool DELETE_STREAM = true;
/// PRESERVE_STREAM - Tell the destructor to not delete the held
/// stream.
///
static const bool PRESERVE_STREAM = false;
private:
/// TheStream - The real stream we output to. We set it to be
/// unbuffered, since we're already doing our own buffering.
///
raw_ostream *TheStream;
/// DeleteStream - Do we need to delete TheStream in the
/// destructor?
///
bool DeleteStream;
/// ColumnScanned - The current output column of the data that's
/// been flushed and the portion of the buffer that's been
/// scanned. The column scheme is zero-based.
///
unsigned ColumnScanned;
/// Scanned - This points to one past the last character in the
/// buffer we've scanned.
///
const char *Scanned;
virtual void write_impl(const char *Ptr, size_t Size);
/// current_pos - Return the current position within the stream,
/// not counting the bytes currently in the buffer.
virtual uint64_t current_pos() {
// This has the same effect as calling TheStream.current_pos(),
// but that interface is private.
return TheStream->tell() - TheStream->GetNumBytesInBuffer();
}
/// ComputeColumn - Examine the given output buffer and figure out which
/// column we end up in after output.
///
void ComputeColumn(const char *Ptr, size_t size);
public:
/// formatted_raw_ostream - Open the specified file for
/// writing. If an error occurs, information about the error is
/// put into ErrorInfo, and the stream should be immediately
/// destroyed; the string will be empty if no error occurred.
///
/// As a side effect, the given Stream is set to be Unbuffered.
/// This is because formatted_raw_ostream does its own buffering,
/// so it doesn't want another layer of buffering to be happening
/// underneath it.
///
formatted_raw_ostream(raw_ostream &Stream, bool Delete = false)
: raw_ostream(), TheStream(0), DeleteStream(false), ColumnScanned(0) {
setStream(Stream, Delete);
}
explicit formatted_raw_ostream()
: raw_ostream(), TheStream(0), DeleteStream(false), ColumnScanned(0) {
Scanned = 0;
}
~formatted_raw_ostream() {
flush();
releaseStream();
}
void setStream(raw_ostream &Stream, bool Delete = false) {
releaseStream();
TheStream = &Stream;
DeleteStream = Delete;
// This formatted_raw_ostream inherits from raw_ostream, so it'll do its
// own buffering, and it doesn't need or want TheStream to do another
// layer of buffering underneath. Resize the buffer to what TheStream
// had been using, and tell TheStream not to do its own buffering.
if (size_t BufferSize = TheStream->GetBufferSize())
SetBufferSize(BufferSize);
else
SetUnbuffered();
TheStream->SetUnbuffered();
Scanned = 0;
}
/// PadToColumn - Align the output to some column number. If the current
/// column is already equal to or more than NewCol, PadToColumn inserts one
/// space.
///
/// \param NewCol - The column to move to.
void PadToColumn(unsigned NewCol);
private:
void releaseStream() {
// Delete the stream if needed. Otherwise, transfer the buffer
// settings from this raw_ostream back to the underlying stream.
if (!TheStream)
return;
if (DeleteStream)
delete TheStream;
else if (size_t BufferSize = GetBufferSize())
TheStream->SetBufferSize(BufferSize);
else
TheStream->SetUnbuffered();
}
};
/// fouts() - This returns a reference to a formatted_raw_ostream for
/// standard output. Use it like: fouts() << "foo" << "bar";
formatted_raw_ostream &fouts();
/// ferrs() - This returns a reference to a formatted_raw_ostream for
/// standard error. Use it like: ferrs() << "foo" << "bar";
formatted_raw_ostream &ferrs();
} // end llvm namespace
#endif