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 20 namespace llvm 21 { 22 /// formatted_raw_ostream - Formatted raw_fd_ostream to handle 23 /// asm-specific constructs. 24 /// 25 class formatted_raw_ostream : public raw_ostream { 26 public: 27 /// DELETE_STREAM - Tell the destructor to delete the held stream. 28 /// 29 static const bool DELETE_STREAM = true; 30 31 /// PRESERVE_STREAM - Tell the destructor to not delete the held 32 /// stream. 33 /// 34 static const bool PRESERVE_STREAM = false; 35 36 private: 37 /// TheStream - The real stream we output to. We set it to be 38 /// unbuffered, since we're already doing our own buffering. 39 /// 40 raw_ostream *TheStream; 41 42 /// DeleteStream - Do we need to delete TheStream in the 43 /// destructor? 44 /// 45 bool DeleteStream; 46 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. 50 /// 51 unsigned ColumnScanned; 52 53 /// Scanned - This points to one past the last character in the 54 /// buffer we've scanned. 55 /// 56 const char *Scanned; 57 58 virtual void write_impl(const char *Ptr, size_t Size); 59 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() const { 63 // This has the same effect as calling TheStream.current_pos(), 64 // but that interface is private. 65 return TheStream->tell() - TheStream->GetNumBytesInBuffer(); 66 } 67 68 /// ComputeColumn - Examine the given output buffer and figure out which 69 /// column we end up in after output. 70 /// 71 void ComputeColumn(const char *Ptr, size_t size); 72 73 public: 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. 78 /// 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 82 /// underneath it. 83 /// 84 formatted_raw_ostream(raw_ostream &Stream, bool Delete = false) 85 : raw_ostream(), TheStream(0), DeleteStream(false), ColumnScanned(0) { 86 setStream(Stream, Delete); 87 } 88 explicit formatted_raw_ostream() 89 : raw_ostream(), TheStream(0), DeleteStream(false), ColumnScanned(0) { 90 Scanned = 0; 91 } 92 93 ~formatted_raw_ostream() { 94 flush(); 95 releaseStream(); 96 } 97 98 void setStream(raw_ostream &Stream, bool Delete = false) { 99 releaseStream(); 100 101 TheStream = &Stream; 102 DeleteStream = Delete; 103 104 // 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); 110 else 111 SetUnbuffered(); 112 TheStream->SetUnbuffered(); 113 114 Scanned = 0; 115 } 116 117 /// PadToColumn - Align the output to some column number. If the current 118 /// column is already equal to or more than NewCol, PadToColumn inserts one 119 /// space. 120 /// 121 /// \param NewCol - The column to move to. 122 formatted_raw_ostream &PadToColumn(unsigned NewCol); 123 124 private: 125 void releaseStream() { 126 // Delete the stream if needed. Otherwise, transfer the buffer 127 // settings from this raw_ostream back to the underlying stream. 128 if (!TheStream) 129 return; 130 if (DeleteStream) 131 delete TheStream; 132 else if (size_t BufferSize = GetBufferSize()) 133 TheStream->SetBufferSize(BufferSize); 134 else 135 TheStream->SetUnbuffered(); 136 } 137 }; 138 139 /// 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(); 142 143 /// 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(); 146 147 /// fdbgs() - This returns a reference to a formatted_raw_ostream for 148 /// debug output. Use it like: fdbgs() << "foo" << "bar"; 149 formatted_raw_ostream &fdbgs(); 150 151 } // end llvm namespace 152 153 154 #endif 155
