lib/Support/FormattedStream.cpp

   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/FormattedStream.h"
  15 using namespace llvm;
  16
  17 /// ComputeColumn - Examine the current output and figure out which
  18 /// column we end up in after output.
  19 ///
  20 void formatted_raw_ostream::ComputeColumn(const char *Ptr, unsigned Size) {
  21   // Keep track of the current column by scanning the string for
  22   // special characters
  23
  24   for (const char *epos = Ptr + Size; Ptr != epos; ++Ptr) {
  25     ++Column;
  26     if (*Ptr == '\n' || *Ptr == '\r')
  27       Column = 0;
  28     else if (*Ptr == '\t')
  29       Column += (8 - (Column & 0x7)) & 0x7;
  30   }
  31 }
  32
  33 /// PadToColumn - Align the output to some column number.
  34 ///
  35 /// \param NewCol - The column to move to.
  36 /// \param MinPad - The minimum space to give after the most recent
  37 /// I/O, even if the current column + minpad > newcol.
  38 ///
  39 void formatted_raw_ostream::PadToColumn(unsigned NewCol, unsigned MinPad) {
  40   flush();
  41
  42   // Output spaces until we reach the desired column.
  43   unsigned num = NewCol - Column;
  44   if (NewCol < Column || num < MinPad)
  45     num = MinPad;
  46
  47   // TODO: Write a whole string at a time.
  48   while (num-- > 0)
  49     write(' ');
  50 }
  51
  52 /// fouts() - This returns a reference to a formatted_raw_ostream for
  53 /// standard output.  Use it like: fouts() << "foo" << "bar";
  54 formatted_raw_ostream &llvm::fouts() {
  55   static formatted_raw_ostream S(outs());
  56   return S;
  57 }
  58
  59 /// ferrs() - This returns a reference to a formatted_raw_ostream for
  60 /// standard error.  Use it like: ferrs() << "foo" << "bar";
  61 formatted_raw_ostream &llvm::ferrs() {
  62   static formatted_raw_ostream S(errs());
  63   return S;
  64 }