aboutsummaryrefslogtreecommitdiffstats
path: root/lib/Format/BreakableToken.cpp
blob: 3e2e0ce7cf3dff36d970df2d0cd7808a2fcdbbe7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
//===--- BreakableToken.cpp - Format C++ code -----------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief Contains implementation of BreakableToken class and classes derived
/// from it.
///
//===----------------------------------------------------------------------===//

#include "BreakableToken.h"
#include "llvm/ADT/STLExtras.h"
#include <algorithm>

namespace clang {
namespace format {

BreakableToken::Split BreakableComment::getSplit(unsigned LineIndex,
                                                 unsigned TailOffset,
                                                 unsigned ColumnLimit) const {
  StringRef Text = getLine(LineIndex).substr(TailOffset);
  unsigned ContentStartColumn = getContentStartColumn(LineIndex, TailOffset);
  if (ColumnLimit <= ContentStartColumn + 1)
    return Split(StringRef::npos, 0);

  unsigned MaxSplit = ColumnLimit - ContentStartColumn + 1;
  StringRef::size_type SpaceOffset = Text.rfind(' ', MaxSplit);
  if (SpaceOffset == StringRef::npos ||
      Text.find_last_not_of(' ', SpaceOffset) == StringRef::npos) {
    SpaceOffset = Text.find(' ', MaxSplit);
  }
  if (SpaceOffset != StringRef::npos && SpaceOffset != 0) {
    StringRef BeforeCut = Text.substr(0, SpaceOffset).rtrim();
    StringRef AfterCut = Text.substr(SpaceOffset).ltrim();
    return BreakableToken::Split(BeforeCut.size(),
                                 AfterCut.begin() - BeforeCut.end());
  }
  return BreakableToken::Split(StringRef::npos, 0);
}

void BreakableComment::insertBreak(unsigned LineIndex, unsigned TailOffset,
                                   Split Split, bool InPPDirective,
                                   WhitespaceManager &Whitespaces) {
  StringRef Text = getLine(LineIndex).substr(TailOffset);
  StringRef AdditionalPrefix = Decoration;
  if (Text.size() == Split.first + Split.second) {
    // For all but the last line handle trailing space in trimLine.
    if (LineIndex < Lines.size() - 1)
      return;
    // For the last line we need to break before "*/", but not to add "* ".
    AdditionalPrefix = "";
  }

  unsigned WhitespaceStartColumn =
      getContentStartColumn(LineIndex, TailOffset) + Split.first;
  unsigned BreakOffset = Text.data() - TokenText.data() + Split.first;
  unsigned CharsToRemove = Split.second;
  Whitespaces.breakToken(Tok, BreakOffset, CharsToRemove, "", AdditionalPrefix,
                         InPPDirective, IndentAtLineBreak,
                         WhitespaceStartColumn);
}

BreakableBlockComment::BreakableBlockComment(const SourceManager &SourceMgr,
                                             const AnnotatedToken &Token,
                                             unsigned StartColumn)
    : BreakableComment(SourceMgr, Token.FormatTok, StartColumn + 2) {
  assert(TokenText.startswith("/*") && TokenText.endswith("*/"));

  OriginalStartColumn =
      SourceMgr.getSpellingColumnNumber(Tok.getStartOfNonWhitespace()) - 1;

  TokenText.substr(2, TokenText.size() - 4).split(Lines, "\n");

  bool NeedsStar = true;
  CommonPrefixLength = UINT_MAX;
  if (Lines.size() == 1) {
    if (Token.Parent == 0) {
      // Standalone block comments will be aligned and prefixed with *s.
      CommonPrefixLength = OriginalStartColumn + 1;
    } else {
      // Trailing comments can start on arbitrary column, and available
      // horizontal space can be too small to align consecutive lines with
      // the first one. We could, probably, align them to current
      // indentation level, but now we just wrap them without indentation
      // and stars.
      CommonPrefixLength = 0;
      NeedsStar = false;
    }
  } else {
    for (size_t i = 1; i < Lines.size(); ++i) {
      size_t FirstNonWhitespace = Lines[i].find_first_not_of(" ");
      if (FirstNonWhitespace != StringRef::npos) {
        NeedsStar = NeedsStar && (Lines[i][FirstNonWhitespace] == '*');
        CommonPrefixLength =
            std::min<unsigned>(CommonPrefixLength, FirstNonWhitespace);
      }
    }
  }
  if (CommonPrefixLength == UINT_MAX)
    CommonPrefixLength = 0;

  Decoration = NeedsStar ? "* " : "";

  IndentAtLineBreak =
      std::max<int>(StartColumn - OriginalStartColumn + CommonPrefixLength, 0);
}

void BreakableBlockComment::alignLines(WhitespaceManager &Whitespaces) {
  SourceLocation TokenLoc = Tok.getStartOfNonWhitespace();
  int IndentDelta = (StartColumn - 2) - OriginalStartColumn;
  if (IndentDelta > 0) {
    std::string WhiteSpace(IndentDelta, ' ');
    for (size_t i = 1; i < Lines.size(); ++i) {
      Whitespaces.addReplacement(
          TokenLoc.getLocWithOffset(Lines[i].data() - TokenText.data()), 0,
          WhiteSpace);
    }
  } else if (IndentDelta < 0) {
    std::string WhiteSpace(-IndentDelta, ' ');
    // Check that the line is indented enough.
    for (size_t i = 1; i < Lines.size(); ++i) {
      if (!Lines[i].startswith(WhiteSpace))
        return;
    }
    for (size_t i = 1; i < Lines.size(); ++i) {
      Whitespaces.addReplacement(
          TokenLoc.getLocWithOffset(Lines[i].data() - TokenText.data()),
          -IndentDelta, "");
    }
  }

  for (unsigned i = 1; i < Lines.size(); ++i)
    Lines[i] = Lines[i].substr(CommonPrefixLength + Decoration.size());
}

void BreakableBlockComment::trimLine(unsigned LineIndex, unsigned TailOffset,
                                     unsigned InPPDirective,
                                     WhitespaceManager &Whitespaces) {
  if (LineIndex == Lines.size() - 1)
    return;
  StringRef Text = Lines[LineIndex].substr(TailOffset);
  if (!Text.endswith(" ") && !InPPDirective)
    return;

  StringRef TrimmedLine = Text.rtrim();
  unsigned WhitespaceStartColumn =
      getLineLengthAfterSplit(LineIndex, TailOffset);
  unsigned BreakOffset = TrimmedLine.end() - TokenText.data();
  unsigned CharsToRemove = Text.size() - TrimmedLine.size() + 1;
  Whitespaces.breakToken(Tok, BreakOffset, CharsToRemove, "", "", InPPDirective,
                         0, WhitespaceStartColumn);
}

BreakableLineComment::BreakableLineComment(const SourceManager &SourceMgr,
                                           const AnnotatedToken &Token,
                                           unsigned StartColumn)
    : BreakableComment(SourceMgr, Token.FormatTok, StartColumn) {
  assert(TokenText.startswith("//"));
  Decoration = getLineCommentPrefix(TokenText);
  Lines.push_back(TokenText.substr(Decoration.size()));
  IndentAtLineBreak = StartColumn;
  this->StartColumn += Decoration.size(); // Start column of the contents.
}

StringRef BreakableLineComment::getLineCommentPrefix(StringRef Comment) {
  const char *KnownPrefixes[] = { "/// ", "///", "// ", "//" };
  for (size_t i = 0; i < llvm::array_lengthof(KnownPrefixes); ++i)
    if (Comment.startswith(KnownPrefixes[i]))
      return KnownPrefixes[i];
  return "";
}

} // namespace format
} // namespace clang