1 //===-- llvm/Support/FormattedStream.cpp - 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 the implementation of formatted_raw_ostream. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "llvm/Support/Debug.h" 15 #include "llvm/Support/FormattedStream.h" 16 #include <algorithm> 17 18 using namespace llvm; 19 20 /// UpdatePosition - Examine the given char sequence and figure out which 21 /// column we end up in after output, and how many line breaks are contained. 22 /// 23 static void UpdatePosition(std::pair<unsigned, unsigned> &Position, const char *Ptr, size_t Size) { 24 unsigned &Column = Position.first; 25 unsigned &Line = Position.second; 26 27 // Keep track of the current column and line by scanning the string for 28 // special characters 29 for (const char *End = Ptr + Size; Ptr != End; ++Ptr) { 30 ++Column; 31 switch (*Ptr) { 32 case '\n': 33 Line += 1; 34 case '\r': 35 Column = 0; 36 break; 37 case '\t': 38 // Assumes tab stop = 8 characters. 39 Column += (8 - (Column & 0x7)) & 0x7; 40 break; 41 } 42 } 43 } 44 45 /// ComputePosition - Examine the current output and update line and column 46 /// counts. 47 void formatted_raw_ostream::ComputePosition(const char *Ptr, size_t Size) { 48 // If our previous scan pointer is inside the buffer, assume we already 49 // scanned those bytes. This depends on raw_ostream to not change our buffer 50 // in unexpected ways. 51 if (Ptr <= Scanned && Scanned <= Ptr + Size) 52 // Scan all characters added since our last scan to determine the new 53 // column. 54 UpdatePosition(Position, Scanned, Size - (Scanned - Ptr)); 55 else 56 UpdatePosition(Position, Ptr, Size); 57 58 // Update the scanning pointer. 59 Scanned = Ptr + Size; 60 } 61 62 /// PadToColumn - Align the output to some column number. 63 /// 64 /// \param NewCol - The column to move to. 65 /// 66 formatted_raw_ostream &formatted_raw_ostream::PadToColumn(unsigned NewCol) { 67 // Figure out what's in the buffer and add it to the column count. 68 ComputePosition(getBufferStart(), GetNumBytesInBuffer()); 69 70 // Output spaces until we reach the desired column. 71 indent(std::max(int(NewCol - getColumn()), 1)); 72 return *this; 73 } 74 75 void formatted_raw_ostream::write_impl(const char *Ptr, size_t Size) { 76 // Figure out what's in the buffer and add it to the column count. 77 ComputePosition(Ptr, Size); 78 79 // Write the data to the underlying stream (which is unbuffered, so 80 // the data will be immediately written out). 81 TheStream->write(Ptr, Size); 82 83 // Reset the scanning pointer. 84 Scanned = nullptr; 85 } 86 87 /// fouts() - This returns a reference to a formatted_raw_ostream for 88 /// standard output. Use it like: fouts() << "foo" << "bar"; 89 formatted_raw_ostream &llvm::fouts() { 90 static formatted_raw_ostream S(outs()); 91 return S; 92 } 93 94 /// ferrs() - This returns a reference to a formatted_raw_ostream for 95 /// standard error. Use it like: ferrs() << "foo" << "bar"; 96 formatted_raw_ostream &llvm::ferrs() { 97 static formatted_raw_ostream S(errs()); 98 return S; 99 } 100 101 /// fdbgs() - This returns a reference to a formatted_raw_ostream for 102 /// the debug stream. Use it like: fdbgs() << "foo" << "bar"; 103 formatted_raw_ostream &llvm::fdbgs() { 104 static formatted_raw_ostream S(dbgs()); 105 return S; 106 } 107
