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