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 #include <string>
22 
23 namespace clang {
24 class SourceManager;
25 
26 namespace format {
27 
28 enum LineType {
29   LT_Invalid,
30   LT_ImportStatement,
31   LT_ObjCDecl, // An @interface, @implementation, or @protocol line.
32   LT_ObjCMethodDecl,
33   LT_ObjCProperty, // An @property line.
34   LT_Other,
35   LT_PreprocessorDirective,
36   LT_VirtualFunctionDecl
37 };
38 
39 class AnnotatedLine {
40 public:
AnnotatedLine(const UnwrappedLine & Line)41   AnnotatedLine(const UnwrappedLine &Line)
42       : First(Line.Tokens.front().Tok), Level(Line.Level),
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 
~AnnotatedLine()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.
startsWith(Ts...Tokens)85   template <typename... Ts> bool startsWith(Ts... Tokens) const {
86     return startsWith(First, Tokens...);
87   }
88 
89   /// \c true if this line looks like a function definition instead of a
90   /// function declaration. Asserts MightBeFunctionDecl.
mightBeFunctionDefinition()91   bool mightBeFunctionDefinition() const {
92     assert(MightBeFunctionDecl);
93     // FIXME: Line.Last points to other characters than tok::semi
94     // and tok::lbrace.
95     return !Last->isOneOf(tok::semi, tok::comment);
96   }
97 
98   FormatToken *First;
99   FormatToken *Last;
100 
101   SmallVector<AnnotatedLine *, 0> Children;
102 
103   LineType Type;
104   unsigned Level;
105   bool InPPDirective;
106   bool MustBeDeclaration;
107   bool MightBeFunctionDecl;
108   bool IsMultiVariableDeclStmt;
109 
110   /// \c True if this line should be formatted, i.e. intersects directly or
111   /// indirectly with one of the input ranges.
112   bool Affected;
113 
114   /// \c True if the leading empty lines of this line intersect with one of the
115   /// input ranges.
116   bool LeadingEmptyLinesAffected;
117 
118   /// \c True if a one of this line's children intersects with an input range.
119   bool ChildrenAffected;
120 
121 private:
122   // Disallow copying.
123   AnnotatedLine(const AnnotatedLine &) = delete;
124   void operator=(const AnnotatedLine &) = delete;
125 
126   template <typename A, typename... Ts>
startsWith(FormatToken * Tok,A K1)127   bool startsWith(FormatToken *Tok, A K1) const {
128     while (Tok && Tok->is(tok::comment))
129       Tok = Tok->Next;
130     return Tok && Tok->is(K1);
131   }
132 
133   template <typename A, typename... Ts>
startsWith(FormatToken * Tok,A K1,Ts...Tokens)134   bool startsWith(FormatToken *Tok, A K1, Ts... Tokens) const {
135     return startsWith(Tok, K1) && startsWith(Tok->Next, Tokens...);
136   }
137 };
138 
139 /// \brief Determines extra information about the tokens comprising an
140 /// \c UnwrappedLine.
141 class TokenAnnotator {
142 public:
TokenAnnotator(const FormatStyle & Style,const AdditionalKeywords & Keywords)143   TokenAnnotator(const FormatStyle &Style, const AdditionalKeywords &Keywords)
144       : Style(Style), Keywords(Keywords) {}
145 
146   /// \brief Adapts the indent levels of comment lines to the indent of the
147   /// subsequent line.
148   // FIXME: Can/should this be done in the UnwrappedLineParser?
149   void setCommentLineLevels(SmallVectorImpl<AnnotatedLine *> &Lines);
150 
151   void annotate(AnnotatedLine &Line);
152   void calculateFormattingInformation(AnnotatedLine &Line);
153 
154 private:
155   /// \brief Calculate the penalty for splitting before \c Tok.
156   unsigned splitPenalty(const AnnotatedLine &Line, const FormatToken &Tok,
157                         bool InFunctionDecl);
158 
159   bool spaceRequiredBetween(const AnnotatedLine &Line, const FormatToken &Left,
160                             const FormatToken &Right);
161 
162   bool spaceRequiredBefore(const AnnotatedLine &Line, const FormatToken &Tok);
163 
164   bool mustBreakBefore(const AnnotatedLine &Line, const FormatToken &Right);
165 
166   bool canBreakBefore(const AnnotatedLine &Line, const FormatToken &Right);
167 
168   bool mustBreakForReturnType(const AnnotatedLine &Line) const;
169 
170   void printDebugInfo(const AnnotatedLine &Line);
171 
172   void calculateUnbreakableTailLengths(AnnotatedLine &Line);
173 
174   const FormatStyle &Style;
175 
176   const AdditionalKeywords &Keywords;
177 };
178 
179 } // end namespace format
180 } // end namespace clang
181 
182 #endif
183