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 #include <utility> 20 21 namespace llvm { 22 23 /// formatted_raw_ostream - A raw_ostream that wraps another one and keeps track 24 /// of line and column position, allowing padding out to specific column 25 /// boundaries and querying the number of lines written to the stream. 26 /// 27 class formatted_raw_ostream : public raw_ostream { 28 /// TheStream - The real stream we output to. We set it to be 29 /// unbuffered, since we're already doing our own buffering. 30 /// 31 raw_ostream *TheStream; 32 33 /// Position - The current output column and line of the data that's 34 /// been flushed and the portion of the buffer that's been 35 /// scanned. The line and column scheme is zero-based. 36 /// 37 std::pair<unsigned, unsigned> Position; 38 39 /// Scanned - This points to one past the last character in the 40 /// buffer we've scanned. 41 /// 42 const char *Scanned; 43 44 void write_impl(const char *Ptr, size_t Size) override; 45 46 /// current_pos - Return the current position within the stream, 47 /// not counting the bytes currently in the buffer. 48 uint64_t current_pos() const override { 49 // Our current position in the stream is all the contents which have been 50 // written to the underlying stream (*not* the current position of the 51 // underlying stream). 52 return TheStream->tell(); 53 } 54 55 /// ComputePosition - Examine the given output buffer and figure out the new 56 /// position after output. 57 /// 58 void ComputePosition(const char *Ptr, size_t size); 59 60 void setStream(raw_ostream &Stream) { 61 releaseStream(); 62 63 TheStream = &Stream; 64 65 // This formatted_raw_ostream inherits from raw_ostream, so it'll do its 66 // own buffering, and it doesn't need or want TheStream to do another 67 // layer of buffering underneath. Resize the buffer to what TheStream 68 // had been using, and tell TheStream not to do its own buffering. 69 if (size_t BufferSize = TheStream->GetBufferSize()) 70 SetBufferSize(BufferSize); 71 else 72 SetUnbuffered(); 73 TheStream->SetUnbuffered(); 74 75 Scanned = nullptr; 76 } 77 78 public: 79 /// formatted_raw_ostream - Open the specified file for 80 /// writing. If an error occurs, information about the error is 81 /// put into ErrorInfo, and the stream should be immediately 82 /// destroyed; the string will be empty if no error occurred. 83 /// 84 /// As a side effect, the given Stream is set to be Unbuffered. 85 /// This is because formatted_raw_ostream does its own buffering, 86 /// so it doesn't want another layer of buffering to be happening 87 /// underneath it. 88 /// 89 formatted_raw_ostream(raw_ostream &Stream) 90 : TheStream(nullptr), Position(0, 0) { 91 setStream(Stream); 92 } 93 explicit formatted_raw_ostream() : TheStream(nullptr), Position(0, 0) { 94 Scanned = nullptr; 95 } 96 97 ~formatted_raw_ostream() override { 98 flush(); 99 releaseStream(); 100 } 101 102 /// PadToColumn - Align the output to some column number. If the current 103 /// column is already equal to or more than NewCol, PadToColumn inserts one 104 /// space. 105 /// 106 /// \param NewCol - The column to move to. 107 formatted_raw_ostream &PadToColumn(unsigned NewCol); 108 109 /// getColumn - Return the column number 110 unsigned getColumn() { return Position.first; } 111 112 /// getLine - Return the line number 113 unsigned getLine() { return Position.second; } 114 115 raw_ostream &resetColor() override { 116 TheStream->resetColor(); 117 return *this; 118 } 119 120 raw_ostream &reverseColor() override { 121 TheStream->reverseColor(); 122 return *this; 123 } 124 125 raw_ostream &changeColor(enum Colors Color, bool Bold, bool BG) override { 126 TheStream->changeColor(Color, Bold, BG); 127 return *this; 128 } 129 130 bool is_displayed() const override { 131 return TheStream->is_displayed(); 132 } 133 134 private: 135 void releaseStream() { 136 // Transfer the buffer settings from this raw_ostream back to the underlying 137 // stream. 138 if (!TheStream) 139 return; 140 if (size_t BufferSize = GetBufferSize()) 141 TheStream->SetBufferSize(BufferSize); 142 else 143 TheStream->SetUnbuffered(); 144 } 145 }; 146 147 /// fouts() - This returns a reference to a formatted_raw_ostream for 148 /// standard output. Use it like: fouts() << "foo" << "bar"; 149 formatted_raw_ostream &fouts(); 150 151 /// ferrs() - This returns a reference to a formatted_raw_ostream for 152 /// standard error. Use it like: ferrs() << "foo" << "bar"; 153 formatted_raw_ostream &ferrs(); 154 155 /// fdbgs() - This returns a reference to a formatted_raw_ostream for 156 /// debug output. Use it like: fdbgs() << "foo" << "bar"; 157 formatted_raw_ostream &fdbgs(); 158 159 } // end llvm namespace 160 161 162 #endif 163
