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) LLVM_OVERRIDE; 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 LLVM_OVERRIDE { 63 // Our current position in the stream is all the contents which have been 64 // written to the underlying stream (*not* the current position of the 65 // underlying stream). 66 return TheStream->tell(); 67 } 68 69 /// ComputeColumn - Examine the given output buffer and figure out which 70 /// column we end up in after output. 71 /// 72 void ComputeColumn(const char *Ptr, size_t size); 73 74 public: 75 /// formatted_raw_ostream - Open the specified file for 76 /// writing. If an error occurs, information about the error is 77 /// put into ErrorInfo, and the stream should be immediately 78 /// destroyed; the string will be empty if no error occurred. 79 /// 80 /// As a side effect, the given Stream is set to be Unbuffered. 81 /// This is because formatted_raw_ostream does its own buffering, 82 /// so it doesn't want another layer of buffering to be happening 83 /// underneath it. 84 /// 85 formatted_raw_ostream(raw_ostream &Stream, bool Delete = false) 86 : raw_ostream(), TheStream(0), DeleteStream(false), ColumnScanned(0) { 87 setStream(Stream, Delete); 88 } 89 explicit formatted_raw_ostream() 90 : raw_ostream(), TheStream(0), DeleteStream(false), ColumnScanned(0) { 91 Scanned = 0; 92 } 93 94 ~formatted_raw_ostream() { 95 flush(); 96 releaseStream(); 97 } 98 99 void setStream(raw_ostream &Stream, bool Delete = false) { 100 releaseStream(); 101 102 TheStream = &Stream; 103 DeleteStream = Delete; 104 105 // This formatted_raw_ostream inherits from raw_ostream, so it'll do its 106 // own buffering, and it doesn't need or want TheStream to do another 107 // layer of buffering underneath. Resize the buffer to what TheStream 108 // had been using, and tell TheStream not to do its own buffering. 109 if (size_t BufferSize = TheStream->GetBufferSize()) 110 SetBufferSize(BufferSize); 111 else 112 SetUnbuffered(); 113 TheStream->SetUnbuffered(); 114 115 Scanned = 0; 116 } 117 118 /// PadToColumn - Align the output to some column number. If the current 119 /// column is already equal to or more than NewCol, PadToColumn inserts one 120 /// space. 121 /// 122 /// \param NewCol - The column to move to. 123 formatted_raw_ostream &PadToColumn(unsigned NewCol); 124 125 private: 126 void releaseStream() { 127 // Delete the stream if needed. Otherwise, transfer the buffer 128 // settings from this raw_ostream back to the underlying stream. 129 if (!TheStream) 130 return; 131 if (DeleteStream) 132 delete TheStream; 133 else if (size_t BufferSize = GetBufferSize()) 134 TheStream->SetBufferSize(BufferSize); 135 else 136 TheStream->SetUnbuffered(); 137 } 138 }; 139 140 /// fouts() - This returns a reference to a formatted_raw_ostream for 141 /// standard output. Use it like: fouts() << "foo" << "bar"; 142 formatted_raw_ostream &fouts(); 143 144 /// ferrs() - This returns a reference to a formatted_raw_ostream for 145 /// standard error. Use it like: ferrs() << "foo" << "bar"; 146 formatted_raw_ostream &ferrs(); 147 148 /// fdbgs() - This returns a reference to a formatted_raw_ostream for 149 /// debug output. Use it like: fdbgs() << "foo" << "bar"; 150 formatted_raw_ostream &fdbgs(); 151 152 } // end llvm namespace 153 154 155 #endif 156
