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 /// UpdatePosition - Examine the given char sequence and figure out which
21 /// column we end up in after output, and how many line breaks are contained.
22 ///
UpdatePosition(std::pair<unsigned,unsigned> & Position,const char * Ptr,size_t Size)23 static void UpdatePosition(std::pair<unsigned, unsigned> &Position, const char *Ptr, size_t Size) {
24 unsigned &Column = Position.first;
25 unsigned &Line = Position.second;
26
27 // Keep track of the current column and line by scanning the string for
28 // special characters
29 for (const char *End = Ptr + Size; Ptr != End; ++Ptr) {
30 ++Column;
31 switch (*Ptr) {
32 case '\n':
33 Line += 1;
34 case '\r':
35 Column = 0;
36 break;
37 case '\t':
38 // Assumes tab stop = 8 characters.
39 Column += (8 - (Column & 0x7)) & 0x7;
40 break;
41 }
42 }
43 }
44
45 /// ComputePosition - Examine the current output and update line and column
46 /// counts.
ComputePosition(const char * Ptr,size_t Size)47 void formatted_raw_ostream::ComputePosition(const char *Ptr, size_t Size) {
48 // If our previous scan pointer is inside the buffer, assume we already
49 // scanned those bytes. This depends on raw_ostream to not change our buffer
50 // in unexpected ways.
51 if (Ptr <= Scanned && Scanned <= Ptr + Size)
52 // Scan all characters added since our last scan to determine the new
53 // column.
54 UpdatePosition(Position, Scanned, Size - (Scanned - Ptr));
55 else
56 UpdatePosition(Position, Ptr, Size);
57
58 // Update the scanning pointer.
59 Scanned = Ptr + Size;
60 }
61
62 /// PadToColumn - Align the output to some column number.
63 ///
64 /// \param NewCol - The column to move to.
65 ///
PadToColumn(unsigned NewCol)66 formatted_raw_ostream &formatted_raw_ostream::PadToColumn(unsigned NewCol) {
67 // Figure out what's in the buffer and add it to the column count.
68 ComputePosition(getBufferStart(), GetNumBytesInBuffer());
69
70 // Output spaces until we reach the desired column.
71 indent(std::max(int(NewCol - getColumn()), 1));
72 return *this;
73 }
74
write_impl(const char * Ptr,size_t Size)75 void formatted_raw_ostream::write_impl(const char *Ptr, size_t Size) {
76 // Figure out what's in the buffer and add it to the column count.
77 ComputePosition(Ptr, Size);
78
79 // Write the data to the underlying stream (which is unbuffered, so
80 // the data will be immediately written out).
81 TheStream->write(Ptr, Size);
82
83 // Reset the scanning pointer.
84 Scanned = nullptr;
85 }
86
87 /// fouts() - This returns a reference to a formatted_raw_ostream for
88 /// standard output. Use it like: fouts() << "foo" << "bar";
fouts()89 formatted_raw_ostream &llvm::fouts() {
90 static formatted_raw_ostream S(outs());
91 return S;
92 }
93
94 /// ferrs() - This returns a reference to a formatted_raw_ostream for
95 /// standard error. Use it like: ferrs() << "foo" << "bar";
ferrs()96 formatted_raw_ostream &llvm::ferrs() {
97 static formatted_raw_ostream S(errs());
98 return S;
99 }
100
101 /// fdbgs() - This returns a reference to a formatted_raw_ostream for
102 /// the debug stream. Use it like: fdbgs() << "foo" << "bar";
fdbgs()103 formatted_raw_ostream &llvm::fdbgs() {
104 static formatted_raw_ostream S(dbgs());
105 return S;
106 }
107