aboutsummaryrefslogtreecommitdiffstats
path: root/lib/Format/TokenAnnotator.h
blob: 702ac6c0d76e7312aee90435285fc01b7222653e (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
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
//===--- TokenAnnotator.h - Format C++ code ---------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file implements a token annotator, i.e. creates
/// \c AnnotatedTokens out of \c FormatTokens with required extra information.
///
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_LIB_FORMAT_TOKENANNOTATOR_H
#define LLVM_CLANG_LIB_FORMAT_TOKENANNOTATOR_H

#include "UnwrappedLineParser.h"
#include "clang/Format/Format.h"

namespace clang {
class SourceManager;

namespace format {

enum LineType {
  LT_Invalid,
  LT_ImportStatement,
  LT_ObjCDecl, // An @interface, @implementation, or @protocol line.
  LT_ObjCMethodDecl,
  LT_ObjCProperty, // An @property line.
  LT_Other,
  LT_PreprocessorDirective,
  LT_VirtualFunctionDecl
};

class AnnotatedLine {
public:
  AnnotatedLine(const UnwrappedLine &Line)
      : First(Line.Tokens.front().Tok), Level(Line.Level),
        MatchingOpeningBlockLineIndex(Line.MatchingOpeningBlockLineIndex),
        MatchingClosingBlockLineIndex(Line.MatchingClosingBlockLineIndex),
        InPPDirective(Line.InPPDirective),
        MustBeDeclaration(Line.MustBeDeclaration), MightBeFunctionDecl(false),
        IsMultiVariableDeclStmt(false), Affected(false),
        LeadingEmptyLinesAffected(false), ChildrenAffected(false),
        FirstStartColumn(Line.FirstStartColumn) {
    assert(!Line.Tokens.empty());

    // Calculate Next and Previous for all tokens. Note that we must overwrite
    // Next and Previous for every token, as previous formatting runs might have
    // left them in a different state.
    First->Previous = nullptr;
    FormatToken *Current = First;
    for (std::list<UnwrappedLineNode>::const_iterator I = ++Line.Tokens.begin(),
                                                      E = Line.Tokens.end();
         I != E; ++I) {
      const UnwrappedLineNode &Node = *I;
      Current->Next = I->Tok;
      I->Tok->Previous = Current;
      Current = Current->Next;
      Current->Children.clear();
      for (const auto &Child : Node.Children) {
        Children.push_back(new AnnotatedLine(Child));
        Current->Children.push_back(Children.back());
      }
    }
    Last = Current;
    Last->Next = nullptr;
  }

  ~AnnotatedLine() {
    for (unsigned i = 0, e = Children.size(); i != e; ++i) {
      delete Children[i];
    }
    FormatToken *Current = First;
    while (Current) {
      Current->Children.clear();
      Current->Role.reset();
      Current = Current->Next;
    }
  }

  /// \c true if this line starts with the given tokens in order, ignoring
  /// comments.
  template <typename... Ts> bool startsWith(Ts... Tokens) const {
    return First && First->startsSequence(Tokens...);
  }

  /// \c true if this line ends with the given tokens in reversed order,
  /// ignoring comments.
  /// For example, given tokens [T1, T2, T3, ...], the function returns true if
  /// this line is like "... T3 T2 T1".
  template <typename... Ts> bool endsWith(Ts... Tokens) const {
    return Last && Last->endsSequence(Tokens...);
  }

  /// \c true if this line looks like a function definition instead of a
  /// function declaration. Asserts MightBeFunctionDecl.
  bool mightBeFunctionDefinition() const {
    assert(MightBeFunctionDecl);
    // Try to determine if the end of a stream of tokens is either the
    // Definition or the Declaration for a function. It does this by looking for
    // the ';' in foo(); and using that it ends with a ; to know this is the
    // Definition, however the line could end with
    //    foo(); /* comment */
    // or
    //    foo(); // comment
    // or
    //    foo() // comment
    // endsWith() ignores the comment.
    return !endsWith(tok::semi);
  }

  /// \c true if this line starts a namespace definition.
  bool startsWithNamespace() const {
    return startsWith(tok::kw_namespace) ||
           startsWith(TT_NamespaceMacro) ||
           startsWith(tok::kw_inline, tok::kw_namespace) ||
           startsWith(tok::kw_export, tok::kw_namespace);
  }

  FormatToken *First;
  FormatToken *Last;

  SmallVector<AnnotatedLine *, 0> Children;

  LineType Type;
  unsigned Level;
  size_t MatchingOpeningBlockLineIndex;
  size_t MatchingClosingBlockLineIndex;
  bool InPPDirective;
  bool MustBeDeclaration;
  bool MightBeFunctionDecl;
  bool IsMultiVariableDeclStmt;

  /// \c True if this line should be formatted, i.e. intersects directly or
  /// indirectly with one of the input ranges.
  bool Affected;

  /// \c True if the leading empty lines of this line intersect with one of the
  /// input ranges.
  bool LeadingEmptyLinesAffected;

  /// \c True if one of this line's children intersects with an input range.
  bool ChildrenAffected;

  unsigned FirstStartColumn;

private:
  // Disallow copying.
  AnnotatedLine(const AnnotatedLine &) = delete;
  void operator=(const AnnotatedLine &) = delete;
};

/// Determines extra information about the tokens comprising an
/// \c UnwrappedLine.
class TokenAnnotator {
public:
  TokenAnnotator(const FormatStyle &Style, const AdditionalKeywords &Keywords)
      : Style(Style), Keywords(Keywords) {}

  /// Adapts the indent levels of comment lines to the indent of the
  /// subsequent line.
  // FIXME: Can/should this be done in the UnwrappedLineParser?
  void setCommentLineLevels(SmallVectorImpl<AnnotatedLine *> &Lines);

  void annotate(AnnotatedLine &Line);
  void calculateFormattingInformation(AnnotatedLine &Line);

private:
  /// Calculate the penalty for splitting before \c Tok.
  unsigned splitPenalty(const AnnotatedLine &Line, const FormatToken &Tok,
                        bool InFunctionDecl);

  bool spaceRequiredBeforeParens(const FormatToken &Right) const;

  bool spaceRequiredBetween(const AnnotatedLine &Line, const FormatToken &Left,
                            const FormatToken &Right);

  bool spaceRequiredBefore(const AnnotatedLine &Line, const FormatToken &Right);

  bool mustBreakBefore(const AnnotatedLine &Line, const FormatToken &Right);

  bool canBreakBefore(const AnnotatedLine &Line, const FormatToken &Right);

  bool mustBreakForReturnType(const AnnotatedLine &Line) const;

  void printDebugInfo(const AnnotatedLine &Line);

  void calculateUnbreakableTailLengths(AnnotatedLine &Line);

  const FormatStyle &Style;

  const AdditionalKeywords &Keywords;
};

} // end namespace format
} // end namespace clang

#endif