1 //===--- TokenAnnotator.h - Format C++ code ---------------------*- 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 /// \file
11 /// \brief This file implements a token annotator, i.e. creates
12 /// \c AnnotatedTokens out of \c FormatTokens with required extra information.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_CLANG_LIB_FORMAT_TOKENANNOTATOR_H
17 #define LLVM_CLANG_LIB_FORMAT_TOKENANNOTATOR_H
18 
19 #include "UnwrappedLineParser.h"
20 #include "clang/Format/Format.h"
21 
22 namespace clang {
23 class SourceManager;
24 
25 namespace format {
26 
27 enum LineType {
28   LT_Invalid,
29   LT_ImportStatement,
30   LT_ObjCDecl, // An @interface, @implementation, or @protocol line.
31   LT_ObjCMethodDecl,
32   LT_ObjCProperty, // An @property line.
33   LT_Other,
34   LT_PreprocessorDirective,
35   LT_VirtualFunctionDecl
36 };
37 
38 class AnnotatedLine {
39 public:
40   AnnotatedLine(const UnwrappedLine &Line)
41       : First(Line.Tokens.front().Tok), Level(Line.Level),
42         MatchingOpeningBlockLineIndex(Line.MatchingOpeningBlockLineIndex),
43         InPPDirective(Line.InPPDirective),
44         MustBeDeclaration(Line.MustBeDeclaration), MightBeFunctionDecl(false),
45         IsMultiVariableDeclStmt(false), Affected(false),
46         LeadingEmptyLinesAffected(false), ChildrenAffected(false) {
47     assert(!Line.Tokens.empty());
48 
49     // Calculate Next and Previous for all tokens. Note that we must overwrite
50     // Next and Previous for every token, as previous formatting runs might have
51     // left them in a different state.
52     First->Previous = nullptr;
53     FormatToken *Current = First;
54     for (std::list<UnwrappedLineNode>::const_iterator I = ++Line.Tokens.begin(),
55                                                       E = Line.Tokens.end();
56          I != E; ++I) {
57       const UnwrappedLineNode &Node = *I;
58       Current->Next = I->Tok;
59       I->Tok->Previous = Current;
60       Current = Current->Next;
61       Current->Children.clear();
62       for (const auto &Child : Node.Children) {
63         Children.push_back(new AnnotatedLine(Child));
64         Current->Children.push_back(Children.back());
65       }
66     }
67     Last = Current;
68     Last->Next = nullptr;
69   }
70 
71   ~AnnotatedLine() {
72     for (unsigned i = 0, e = Children.size(); i != e; ++i) {
73       delete Children[i];
74     }
75     FormatToken *Current = First;
76     while (Current) {
77       Current->Children.clear();
78       Current->Role.reset();
79       Current = Current->Next;
80     }
81   }
82 
83   /// \c true if this line starts with the given tokens in order, ignoring
84   /// comments.
85   template <typename... Ts> bool startsWith(Ts... Tokens) const {
86     return First && First->startsSequence(Tokens...);
87   }
88 
89   /// \c true if this line ends with the given tokens in reversed order,
90   /// ignoring comments.
91   /// For example, given tokens [T1, T2, T3, ...], the function returns true if
92   /// this line is like "... T3 T2 T1".
93   template <typename... Ts> bool endsWith(Ts... Tokens) const {
94     return Last && Last->endsSequence(Tokens...);
95   }
96 
97   /// \c true if this line looks like a function definition instead of a
98   /// function declaration. Asserts MightBeFunctionDecl.
99   bool mightBeFunctionDefinition() const {
100     assert(MightBeFunctionDecl);
101     // FIXME: Line.Last points to other characters than tok::semi
102     // and tok::lbrace.
103     return !Last->isOneOf(tok::semi, tok::comment);
104   }
105 
106   FormatToken *First;
107   FormatToken *Last;
108 
109   SmallVector<AnnotatedLine *, 0> Children;
110 
111   LineType Type;
112   unsigned Level;
113   size_t MatchingOpeningBlockLineIndex;
114   bool InPPDirective;
115   bool MustBeDeclaration;
116   bool MightBeFunctionDecl;
117   bool IsMultiVariableDeclStmt;
118 
119   /// \c True if this line should be formatted, i.e. intersects directly or
120   /// indirectly with one of the input ranges.
121   bool Affected;
122 
123   /// \c True if the leading empty lines of this line intersect with one of the
124   /// input ranges.
125   bool LeadingEmptyLinesAffected;
126 
127   /// \c True if one of this line's children intersects with an input range.
128   bool ChildrenAffected;
129 
130 private:
131   // Disallow copying.
132   AnnotatedLine(const AnnotatedLine &) = delete;
133   void operator=(const AnnotatedLine &) = delete;
134 };
135 
136 /// \brief Determines extra information about the tokens comprising an
137 /// \c UnwrappedLine.
138 class TokenAnnotator {
139 public:
140   TokenAnnotator(const FormatStyle &Style, const AdditionalKeywords &Keywords)
141       : Style(Style), Keywords(Keywords) {}
142 
143   /// \brief Adapts the indent levels of comment lines to the indent of the
144   /// subsequent line.
145   // FIXME: Can/should this be done in the UnwrappedLineParser?
146   void setCommentLineLevels(SmallVectorImpl<AnnotatedLine *> &Lines);
147 
148   void annotate(AnnotatedLine &Line);
149   void calculateFormattingInformation(AnnotatedLine &Line);
150 
151 private:
152   /// \brief Calculate the penalty for splitting before \c Tok.
153   unsigned splitPenalty(const AnnotatedLine &Line, const FormatToken &Tok,
154                         bool InFunctionDecl);
155 
156   bool spaceRequiredBetween(const AnnotatedLine &Line, const FormatToken &Left,
157                             const FormatToken &Right);
158 
159   bool spaceRequiredBefore(const AnnotatedLine &Line, const FormatToken &Tok);
160 
161   bool mustBreakBefore(const AnnotatedLine &Line, const FormatToken &Right);
162 
163   bool canBreakBefore(const AnnotatedLine &Line, const FormatToken &Right);
164 
165   bool mustBreakForReturnType(const AnnotatedLine &Line) const;
166 
167   void printDebugInfo(const AnnotatedLine &Line);
168 
169   void calculateUnbreakableTailLengths(AnnotatedLine &Line);
170 
171   const FormatStyle &Style;
172 
173   const AdditionalKeywords &Keywords;
174 };
175 
176 } // end namespace format
177 } // end namespace clang
178 
179 #endif
180