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