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 #include <algorithm>
16 
17 using namespace llvm;
18 
19 /// ComputeColumn - Examine the current output and figure out which
20 /// column we end up in after output.
21 ///
22 void formatted_raw_ostream::ComputeColumn(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 *epos = Ptr + Size; Ptr != epos; ++Ptr) {
27     ++Column;
28     if (*Ptr == '\n' || *Ptr == '\r')
29       Column = 0;
30     else if (*Ptr == '\t')
31       Column += (8 - (Column & 0x7)) & 0x7;
32   }
33 }
34 
35 /// PadToColumn - Align the output to some column number.
36 ///
37 /// \param NewCol - The column to move to.
38 /// \param MinPad - The minimum space to give after the most recent
39 /// I/O, even if the current column + minpad > newcol.
40 ///
41 void formatted_raw_ostream::PadToColumn(unsigned NewCol, unsigned MinPad) {
42   flush();
43 
44   // Output spaces until we reach the desired column.
45   unsigned num = NewCol - Column;
46   if (NewCol < Column || num < MinPad)
47     num = MinPad;
48 
49   // Keep a buffer of spaces handy to speed up processing.
50   static char Spaces[MAX_COLUMN_PAD];
51   static bool Initialized = false;
52   if (!Initialized) {
53     std::fill_n(Spaces, MAX_COLUMN_PAD, ' '),
54     Initialized = true;
55   }
56 
57   assert(num < MAX_COLUMN_PAD && "Unexpectedly large column padding");
58 
59   write(Spaces, num);
60 }
61 
62 /// fouts() - This returns a reference to a formatted_raw_ostream for
63 /// standard output.  Use it like: fouts() << "foo" << "bar";
64 formatted_raw_ostream &llvm::fouts() {
65   static formatted_raw_ostream S(outs());
66   return S;
67 }
68 
69 /// ferrs() - This returns a reference to a formatted_raw_ostream for
70 /// standard error.  Use it like: ferrs() << "foo" << "bar";
71 formatted_raw_ostream &llvm::ferrs() {
72   static formatted_raw_ostream S(errs());
73   return S;
74 }
75