LLVM  6.0.0svn
FormattedStream.h
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1 //===-- llvm/Support/FormattedStream.h - 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 raw_ostream implementations for streams to do
11 // things like pretty-print comments.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_SUPPORT_FORMATTEDSTREAM_H
16 #define LLVM_SUPPORT_FORMATTEDSTREAM_H
17 
19 #include <utility>
20 
21 namespace llvm {
22 
23 /// formatted_raw_ostream - A raw_ostream that wraps another one and keeps track
24 /// of line and column position, allowing padding out to specific column
25 /// boundaries and querying the number of lines written to the stream.
26 ///
28  /// TheStream - The real stream we output to. We set it to be
29  /// unbuffered, since we're already doing our own buffering.
30  ///
31  raw_ostream *TheStream;
32 
33  /// Position - The current output column and line of the data that's
34  /// been flushed and the portion of the buffer that's been
35  /// scanned. The line and column scheme is zero-based.
36  ///
37  std::pair<unsigned, unsigned> Position;
38 
39  /// Scanned - This points to one past the last character in the
40  /// buffer we've scanned.
41  ///
42  const char *Scanned;
43 
44  void write_impl(const char *Ptr, size_t Size) override;
45 
46  /// current_pos - Return the current position within the stream,
47  /// not counting the bytes currently in the buffer.
48  uint64_t current_pos() const override {
49  // Our current position in the stream is all the contents which have been
50  // written to the underlying stream (*not* the current position of the
51  // underlying stream).
52  return TheStream->tell();
53  }
54 
55  /// ComputePosition - Examine the given output buffer and figure out the new
56  /// position after output.
57  ///
58  void ComputePosition(const char *Ptr, size_t size);
59 
60  void setStream(raw_ostream &Stream) {
61  releaseStream();
62 
63  TheStream = &Stream;
64 
65  // This formatted_raw_ostream inherits from raw_ostream, so it'll do its
66  // own buffering, and it doesn't need or want TheStream to do another
67  // layer of buffering underneath. Resize the buffer to what TheStream
68  // had been using, and tell TheStream not to do its own buffering.
69  if (size_t BufferSize = TheStream->GetBufferSize())
70  SetBufferSize(BufferSize);
71  else
72  SetUnbuffered();
73  TheStream->SetUnbuffered();
74 
75  Scanned = nullptr;
76  }
77 
78 public:
79  /// formatted_raw_ostream - Open the specified file for
80  /// writing. If an error occurs, information about the error is
81  /// put into ErrorInfo, and the stream should be immediately
82  /// destroyed; the string will be empty if no error occurred.
83  ///
84  /// As a side effect, the given Stream is set to be Unbuffered.
85  /// This is because formatted_raw_ostream does its own buffering,
86  /// so it doesn't want another layer of buffering to be happening
87  /// underneath it.
88  ///
90  : TheStream(nullptr), Position(0, 0) {
91  setStream(Stream);
92  }
93  explicit formatted_raw_ostream() : TheStream(nullptr), Position(0, 0) {
94  Scanned = nullptr;
95  }
96 
98  flush();
99  releaseStream();
100  }
101 
102  /// PadToColumn - Align the output to some column number. If the current
103  /// column is already equal to or more than NewCol, PadToColumn inserts one
104  /// space.
105  ///
106  /// \param NewCol - The column to move to.
107  formatted_raw_ostream &PadToColumn(unsigned NewCol);
108 
109  /// getColumn - Return the column number
110  unsigned getColumn() { return Position.first; }
111 
112  /// getLine - Return the line number
113  unsigned getLine() { return Position.second; }
114 
115  raw_ostream &resetColor() override {
116  TheStream->resetColor();
117  return *this;
118  }
119 
120  raw_ostream &reverseColor() override {
121  TheStream->reverseColor();
122  return *this;
123  }
124 
125  raw_ostream &changeColor(enum Colors Color, bool Bold, bool BG) override {
126  TheStream->changeColor(Color, Bold, BG);
127  return *this;
128  }
129 
130  bool is_displayed() const override {
131  return TheStream->is_displayed();
132  }
133 
134 private:
135  void releaseStream() {
136  // Transfer the buffer settings from this raw_ostream back to the underlying
137  // stream.
138  if (!TheStream)
139  return;
140  if (size_t BufferSize = GetBufferSize())
141  TheStream->SetBufferSize(BufferSize);
142  else
143  TheStream->SetUnbuffered();
144  }
145 };
146 
147 /// fouts() - This returns a reference to a formatted_raw_ostream for
148 /// standard output. Use it like: fouts() << "foo" << "bar";
150 
151 /// ferrs() - This returns a reference to a formatted_raw_ostream for
152 /// standard error. Use it like: ferrs() << "foo" << "bar";
154 
155 /// fdbgs() - This returns a reference to a formatted_raw_ostream for
156 /// debug output. Use it like: fdbgs() << "foo" << "bar";
158 
159 } // end llvm namespace
160 
161 
162 #endif
Compute iterated dominance frontiers using a linear time algorithm.
Definition: AllocatorList.h:24
formatted_raw_ostream(raw_ostream &Stream)
formatted_raw_ostream - Open the specified file for writing.
formatted_raw_ostream - A raw_ostream that wraps another one and keeps track of line and column posit...
size_t GetBufferSize() const
Definition: raw_ostream.h:114
virtual raw_ostream & changeColor(enum Colors Color, bool Bold=false, bool BG=false)
Changes the foreground color of text that will be output from this point forward. ...
Definition: raw_ostream.h:252
bool is_displayed() const override
This function determines if this stream is connected to a "tty" or "console" window.
raw_ostream & resetColor() override
Resets the colors to terminal defaults.
formatted_raw_ostream & PadToColumn(unsigned NewCol)
PadToColumn - Align the output to some column number.
unsigned getLine()
getLine - Return the line number
raw_ostream & changeColor(enum Colors Color, bool Bold, bool BG) override
Changes the foreground color of text that will be output from this point forward. ...
unsigned getColumn()
getColumn - Return the column number
void SetUnbuffered()
Set the stream to be unbuffered.
Definition: raw_ostream.h:127
virtual raw_ostream & reverseColor()
Reverses the foreground and background colors.
Definition: raw_ostream.h:266
void SetBufferSize(size_t Size)
Set the stream to be buffered, using the specified buffer size.
Definition: raw_ostream.h:109
Color
A "color", which is either even or odd.
virtual bool is_displayed() const
This function determines if this stream is connected to a "tty" or "console" window.
Definition: raw_ostream.h:271
formatted_raw_ostream & fdbgs()
fdbgs() - This returns a reference to a formatted_raw_ostream for debug output.
formatted_raw_ostream & ferrs()
ferrs() - This returns a reference to a formatted_raw_ostream for standard error. ...
virtual raw_ostream & resetColor()
Resets the colors to terminal defaults.
Definition: raw_ostream.h:263
constexpr char Size[]
Key for Kernel::Arg::Metadata::mSize.
uint64_t tell() const
tell - Return the current offset with the file.
Definition: raw_ostream.h:98
This class implements an extremely fast bulk output stream that can only output to a stream...
Definition: raw_ostream.h:44
formatted_raw_ostream & fouts()
fouts() - This returns a reference to a formatted_raw_ostream for standard output.
raw_ostream & reverseColor() override
Reverses the foreground and background colors.