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 ///
CountColumns(unsigned Column,const char * Ptr,size_t Size)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.
ComputeColumn(const char * Ptr,size_t Size)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 ///
PadToColumn(unsigned NewCol)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
write_impl(const char * Ptr,size_t Size)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";
fouts()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";
ferrs()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";
fdbgs()98 formatted_raw_ostream &llvm::fdbgs() {
99 static formatted_raw_ostream S(dbgs());
100 return S;
101 }
102