FormattedStream.h revision af0636f4d63e6ff2fd066d4594d8666459d1930d
1//===-- llvm/Support/FormattedStream.h - Formatted streams ------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file contains raw_ostream implementations for streams to do 11// things like pretty-print comments. 12// 13//===----------------------------------------------------------------------===// 14 15#ifndef LLVM_SUPPORT_FORMATTEDSTREAM_H 16#define LLVM_SUPPORT_FORMATTEDSTREAM_H 17 18#include "llvm/Support/raw_ostream.h" 19 20namespace llvm 21{ 22 class formatted_tool_output_file; 23 24 /// formatted_raw_ostream - Formatted raw_fd_ostream to handle 25 /// asm-specific constructs. 26 /// 27 class formatted_raw_ostream : public raw_ostream { 28 friend class formatted_tool_output_file; 29 30 public: 31 /// DELETE_STREAM - Tell the destructor to delete the held stream. 32 /// 33 static const bool DELETE_STREAM = true; 34 35 /// PRESERVE_STREAM - Tell the destructor to not delete the held 36 /// stream. 37 /// 38 static const bool PRESERVE_STREAM = false; 39 40 private: 41 /// TheStream - The real stream we output to. We set it to be 42 /// unbuffered, since we're already doing our own buffering. 43 /// 44 raw_ostream *TheStream; 45 46 /// DeleteStream - Do we need to delete TheStream in the 47 /// destructor? 48 /// 49 bool DeleteStream; 50 51 /// ColumnScanned - The current output column of the data that's 52 /// been flushed and the portion of the buffer that's been 53 /// scanned. The column scheme is zero-based. 54 /// 55 unsigned ColumnScanned; 56 57 /// Scanned - This points to one past the last character in the 58 /// buffer we've scanned. 59 /// 60 const char *Scanned; 61 62 virtual void write_impl(const char *Ptr, size_t Size); 63 64 /// current_pos - Return the current position within the stream, 65 /// not counting the bytes currently in the buffer. 66 virtual uint64_t current_pos() const { 67 // This has the same effect as calling TheStream.current_pos(), 68 // but that interface is private. 69 return TheStream->tell() - TheStream->GetNumBytesInBuffer(); 70 } 71 72 /// ComputeColumn - Examine the given output buffer and figure out which 73 /// column we end up in after output. 74 /// 75 void ComputeColumn(const char *Ptr, size_t size); 76 77 public: 78 /// formatted_raw_ostream - Open the specified file for 79 /// writing. If an error occurs, information about the error is 80 /// put into ErrorInfo, and the stream should be immediately 81 /// destroyed; the string will be empty if no error occurred. 82 /// 83 /// As a side effect, the given Stream is set to be Unbuffered. 84 /// This is because formatted_raw_ostream does its own buffering, 85 /// so it doesn't want another layer of buffering to be happening 86 /// underneath it. 87 /// 88 formatted_raw_ostream(raw_ostream &Stream, bool Delete = false) 89 : raw_ostream(), TheStream(0), DeleteStream(false), ColumnScanned(0) { 90 setStream(Stream, Delete); 91 } 92 explicit formatted_raw_ostream() 93 : raw_ostream(), TheStream(0), DeleteStream(false), ColumnScanned(0) { 94 Scanned = 0; 95 } 96 97 ~formatted_raw_ostream() { 98 flush(); 99 releaseStream(); 100 } 101 102 void setStream(raw_ostream &Stream, bool Delete = false) { 103 releaseStream(); 104 105 TheStream = &Stream; 106 DeleteStream = Delete; 107 108 // This formatted_raw_ostream inherits from raw_ostream, so it'll do its 109 // own buffering, and it doesn't need or want TheStream to do another 110 // layer of buffering underneath. Resize the buffer to what TheStream 111 // had been using, and tell TheStream not to do its own buffering. 112 if (size_t BufferSize = TheStream->GetBufferSize()) 113 SetBufferSize(BufferSize); 114 else 115 SetUnbuffered(); 116 TheStream->SetUnbuffered(); 117 118 Scanned = 0; 119 } 120 121 /// PadToColumn - Align the output to some column number. If the current 122 /// column is already equal to or more than NewCol, PadToColumn inserts one 123 /// space. 124 /// 125 /// \param NewCol - The column to move to. 126 formatted_raw_ostream &PadToColumn(unsigned NewCol); 127 128 private: 129 void releaseStream() { 130 // Delete the stream if needed. Otherwise, transfer the buffer 131 // settings from this raw_ostream back to the underlying stream. 132 if (!TheStream) 133 return; 134 if (DeleteStream) 135 delete TheStream; 136 else if (size_t BufferSize = GetBufferSize()) 137 TheStream->SetBufferSize(BufferSize); 138 else 139 TheStream->SetUnbuffered(); 140 } 141 }; 142 143 /// formatted_tool_output_file - This is a subclass of formatted_raw_ostream 144 /// for use when the underlying stream is a tool_output_file. It exposes 145 /// the keep() member function. 146 class formatted_tool_output_file : public formatted_raw_ostream { 147 public: 148 formatted_tool_output_file(tool_output_file &Stream, bool Delete = false) 149 : formatted_raw_ostream(Stream, Delete) {} 150 151 formatted_tool_output_file() {} 152 153 ~formatted_tool_output_file(); 154 155 void setStream(tool_output_file &Stream, bool Delete = false) { 156 return formatted_raw_ostream::setStream(Stream, Delete); 157 } 158 159 void keep() { return static_cast<tool_output_file *>(TheStream)->keep(); } 160 }; 161 162/// fouts() - This returns a reference to a formatted_raw_ostream for 163/// standard output. Use it like: fouts() << "foo" << "bar"; 164formatted_raw_ostream &fouts(); 165 166/// ferrs() - This returns a reference to a formatted_raw_ostream for 167/// standard error. Use it like: ferrs() << "foo" << "bar"; 168formatted_raw_ostream &ferrs(); 169 170/// fdbgs() - This returns a reference to a formatted_raw_ostream for 171/// debug output. Use it like: fdbgs() << "foo" << "bar"; 172formatted_raw_ostream &fdbgs(); 173 174} // end llvm namespace 175 176 177#endif 178