1 //===-- llvm/CodeGen/FormattedStream.h - Formatted streams ------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains raw_ostream implementations for streams to do
11 // things like pretty-print comments.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_SUPPORT_FORMATTEDSTREAM_H
16 #define LLVM_SUPPORT_FORMATTEDSTREAM_H
18 #include "llvm/Support/raw_ostream.h"
22 /// formatted_raw_ostream - Formatted raw_fd_ostream to handle
23 /// asm-specific constructs.
25 class formatted_raw_ostream : public raw_ostream {
27 /// DELETE_STREAM - Tell the destructor to delete the held stream.
29 static const bool DELETE_STREAM = true;
31 /// PRESERVE_STREAM - Tell the destructor to not delete the held
34 static const bool PRESERVE_STREAM = false;
37 /// TheStream - The real stream we output to. We set it to be
38 /// unbuffered, since we're already doing our own buffering.
40 raw_ostream *TheStream;
42 /// DeleteStream - Do we need to delete TheStream in the
47 /// ColumnScanned - The current output column of the data that's
48 /// been flushed and the portion of the buffer that's been
49 /// scanned. The column scheme is zero-based.
51 unsigned ColumnScanned;
53 /// Scanned - This points to one past the last character in the
54 /// buffer we've scanned.
58 virtual void write_impl(const char *Ptr, size_t Size);
60 /// current_pos - Return the current position within the stream,
61 /// not counting the bytes currently in the buffer.
62 virtual uint64_t current_pos() {
63 // This has the same effect as calling TheStream.current_pos(),
64 // but that interface is private.
65 return TheStream->tell() - TheStream->GetNumBytesInBuffer();
68 /// ComputeColumn - Examine the given output buffer and figure out which
69 /// column we end up in after output.
71 void ComputeColumn(const char *Ptr, size_t size);
74 /// formatted_raw_ostream - Open the specified file for
75 /// writing. If an error occurs, information about the error is
76 /// put into ErrorInfo, and the stream should be immediately
77 /// destroyed; the string will be empty if no error occurred.
79 /// As a side effect, the given Stream is set to be Unbuffered.
80 /// This is because formatted_raw_ostream does its own buffering,
81 /// so it doesn't want another layer of buffering to be happening
84 formatted_raw_ostream(raw_ostream &Stream, bool Delete = false)
85 : raw_ostream(), TheStream(0), DeleteStream(false), ColumnScanned(0) {
86 setStream(Stream, Delete);
88 explicit formatted_raw_ostream()
89 : raw_ostream(), TheStream(0), DeleteStream(false), ColumnScanned(0) {
93 ~formatted_raw_ostream() {
98 void setStream(raw_ostream &Stream, bool Delete = false) {
102 DeleteStream = Delete;
104 // This formatted_raw_ostream inherits from raw_ostream, so it'll do its
105 // own buffering, and it doesn't need or want TheStream to do another
106 // layer of buffering underneath. Resize the buffer to what TheStream
107 // had been using, and tell TheStream not to do its own buffering.
108 if (size_t BufferSize = TheStream->GetBufferSize())
109 SetBufferSize(BufferSize);
112 TheStream->SetUnbuffered();
117 /// PadToColumn - Align the output to some column number. If the current
118 /// column is already equal to or more than NewCol, PadToColumn inserts one
121 /// \param NewCol - The column to move to.
122 void PadToColumn(unsigned NewCol);
125 void releaseStream() {
126 // Delete the stream if needed. Otherwise, transfer the buffer
127 // settings from this raw_ostream back to the underlying stream.
132 else if (size_t BufferSize = GetBufferSize())
133 TheStream->SetBufferSize(BufferSize);
135 TheStream->SetUnbuffered();
139 /// fouts() - This returns a reference to a formatted_raw_ostream for
140 /// standard output. Use it like: fouts() << "foo" << "bar";
141 formatted_raw_ostream &fouts();
143 /// ferrs() - This returns a reference to a formatted_raw_ostream for
144 /// standard error. Use it like: ferrs() << "foo" << "bar";
145 formatted_raw_ostream &ferrs();
147 } // end llvm namespace