clang  5.0.0
UnwrappedLineParser.h
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1 //===--- UnwrappedLineParser.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 contains the declaration of the UnwrappedLineParser,
12 /// which turns a stream of tokens into UnwrappedLines.
13 ///
14 //===----------------------------------------------------------------------===//
15 
16 #ifndef LLVM_CLANG_LIB_FORMAT_UNWRAPPEDLINEPARSER_H
17 #define LLVM_CLANG_LIB_FORMAT_UNWRAPPEDLINEPARSER_H
18 
19 #include "FormatToken.h"
21 #include "clang/Format/Format.h"
22 #include "llvm/Support/Regex.h"
23 #include <list>
24 #include <stack>
25 
26 namespace clang {
27 namespace format {
28 
29 struct UnwrappedLineNode;
30 
31 /// \brief An unwrapped line is a sequence of \c Token, that we would like to
32 /// put on a single line if there was no column limit.
33 ///
34 /// This is used as a main interface between the \c UnwrappedLineParser and the
35 /// \c UnwrappedLineFormatter. The key property is that changing the formatting
36 /// within an unwrapped line does not affect any other unwrapped lines.
37 struct UnwrappedLine {
38  UnwrappedLine();
39 
40  // FIXME: Don't use std::list here.
41  /// \brief The \c Tokens comprising this \c UnwrappedLine.
42  std::list<UnwrappedLineNode> Tokens;
43 
44  /// \brief The indent level of the \c UnwrappedLine.
45  unsigned Level;
46 
47  /// \brief Whether this \c UnwrappedLine is part of a preprocessor directive.
49 
51 
52  /// \brief If this \c UnwrappedLine closes a block in a sequence of lines,
53  /// \c MatchingOpeningBlockLineIndex stores the index of the corresponding
54  /// opening line. Otherwise, \c MatchingOpeningBlockLineIndex must be
55  /// \c kInvalidIndex.
57 
58  static const size_t kInvalidIndex = -1;
59 };
60 
62 public:
64  virtual void consumeUnwrappedLine(const UnwrappedLine &Line) = 0;
65  virtual void finishRun() = 0;
66 };
67 
68 class FormatTokenSource;
69 
71 public:
72  UnwrappedLineParser(const FormatStyle &Style,
73  const AdditionalKeywords &Keywords,
75  UnwrappedLineConsumer &Callback);
76 
77  void parse();
78 
79 private:
80  void reset();
81  void parseFile();
82  void parseLevel(bool HasOpeningBrace);
83  void parseBlock(bool MustBeDeclaration, bool AddLevel = true,
84  bool MunchSemi = true);
85  void parseChildBlock();
86  void parsePPDirective();
87  void parsePPDefine();
88  void parsePPIf(bool IfDef);
89  void parsePPElIf();
90  void parsePPElse();
91  void parsePPEndIf();
92  void parsePPUnknown();
93  void readTokenWithJavaScriptASI();
94  void parseStructuralElement();
95  bool tryToParseBracedList();
96  bool parseBracedList(bool ContinueOnSemicolons = false,
97  tok::TokenKind ClosingBraceKind = tok::r_brace);
98  void parseParens();
99  void parseSquare();
100  void parseIfThenElse();
101  void parseTryCatch();
102  void parseForOrWhileLoop();
103  void parseDoWhile();
104  void parseLabel();
105  void parseCaseLabel();
106  void parseSwitch();
107  void parseNamespace();
108  void parseNew();
109  void parseAccessSpecifier();
110  bool parseEnum();
111  void parseJavaEnumBody();
112  // Parses a record (aka class) as a top level element. If ParseAsExpr is true,
113  // parses the record as a child block, i.e. if the class declaration is an
114  // expression.
115  void parseRecord(bool ParseAsExpr = false);
116  void parseObjCProtocolList();
117  void parseObjCUntilAtEnd();
118  void parseObjCInterfaceOrImplementation();
119  void parseObjCProtocol();
120  void parseJavaScriptEs6ImportExport();
121  bool tryToParseLambda();
122  bool tryToParseLambdaIntroducer();
123  void tryToParseJSFunction();
124  void addUnwrappedLine();
125  bool eof() const;
126  void nextToken();
127  const FormatToken *getPreviousToken();
128  void readToken();
129 
130  // Decides which comment tokens should be added to the current line and which
131  // should be added as comments before the next token.
132  //
133  // Comments specifies the sequence of comment tokens to analyze. They get
134  // either pushed to the current line or added to the comments before the next
135  // token.
136  //
137  // NextTok specifies the next token. A null pointer NextTok is supported, and
138  // signifies either the absense of a next token, or that the next token
139  // shouldn't be taken into accunt for the analysis.
140  void distributeComments(const SmallVectorImpl<FormatToken *> &Comments,
141  const FormatToken *NextTok);
142 
143  // Adds the comment preceding the next token to unwrapped lines.
144  void flushComments(bool NewlineBeforeNext);
145  void pushToken(FormatToken *Tok);
146  void calculateBraceTypes(bool ExpectClassBody = false);
147 
148  // Marks a conditional compilation edge (for example, an '#if', '#ifdef',
149  // '#else' or merge conflict marker). If 'Unreachable' is true, assumes
150  // this branch either cannot be taken (for example '#if false'), or should
151  // not be taken in this round.
152  void conditionalCompilationCondition(bool Unreachable);
153  void conditionalCompilationStart(bool Unreachable);
154  void conditionalCompilationAlternative();
155  void conditionalCompilationEnd();
156 
157  bool isOnNewLine(const FormatToken &FormatTok);
158 
159  // FIXME: We are constantly running into bugs where Line.Level is incorrectly
160  // subtracted from beyond 0. Introduce a method to subtract from Line.Level
161  // and use that everywhere in the Parser.
162  std::unique_ptr<UnwrappedLine> Line;
163 
164  // Comments are sorted into unwrapped lines by whether they are in the same
165  // line as the previous token, or not. If not, they belong to the next token.
166  // Since the next token might already be in a new unwrapped line, we need to
167  // store the comments belonging to that token.
168  SmallVector<FormatToken *, 1> CommentsBeforeNextToken;
169  FormatToken *FormatTok;
170  bool MustBreakBeforeNextToken;
171 
172  // The parsed lines. Only added to through \c CurrentLines.
174 
175  // Preprocessor directives are parsed out-of-order from other unwrapped lines.
176  // Thus, we need to keep a list of preprocessor directives to be reported
177  // after an unwarpped line that has been started was finished.
178  SmallVector<UnwrappedLine, 4> PreprocessorDirectives;
179 
180  // New unwrapped lines are added via CurrentLines.
181  // Usually points to \c &Lines. While parsing a preprocessor directive when
182  // there is an unfinished previous unwrapped line, will point to
183  // \c &PreprocessorDirectives.
184  SmallVectorImpl<UnwrappedLine> *CurrentLines;
185 
186  // We store for each line whether it must be a declaration depending on
187  // whether we are in a compound statement or not.
188  std::vector<bool> DeclarationScopeStack;
189 
190  const FormatStyle &Style;
191  const AdditionalKeywords &Keywords;
192 
193  llvm::Regex CommentPragmasRegex;
194 
195  FormatTokenSource *Tokens;
196  UnwrappedLineConsumer &Callback;
197 
198  // FIXME: This is a temporary measure until we have reworked the ownership
199  // of the format tokens. The goal is to have the actual tokens created and
200  // owned outside of and handed into the UnwrappedLineParser.
201  ArrayRef<FormatToken *> AllTokens;
202 
203  // Represents preprocessor branch type, so we can find matching
204  // #if/#else/#endif directives.
205  enum PPBranchKind {
206  PP_Conditional, // Any #if, #ifdef, #ifndef, #elif, block outside #if 0
207  PP_Unreachable // #if 0 or a conditional preprocessor block inside #if 0
208  };
209 
210  // Keeps a stack of currently active preprocessor branching directives.
212 
213  // The \c UnwrappedLineParser re-parses the code for each combination
214  // of preprocessor branches that can be taken.
215  // To that end, we take the same branch (#if, #else, or one of the #elif
216  // branches) for each nesting level of preprocessor branches.
217  // \c PPBranchLevel stores the current nesting level of preprocessor
218  // branches during one pass over the code.
219  int PPBranchLevel;
220 
221  // Contains the current branch (#if, #else or one of the #elif branches)
222  // for each nesting level.
223  SmallVector<int, 8> PPLevelBranchIndex;
224 
225  // Contains the maximum number of branches at each nesting level.
226  SmallVector<int, 8> PPLevelBranchCount;
227 
228  // Contains the number of branches per nesting level we are currently
229  // in while parsing a preprocessor branch sequence.
230  // This is used to update PPLevelBranchCount at the end of a branch
231  // sequence.
232  std::stack<int> PPChainBranchIndex;
233 
234  friend class ScopedLineState;
236 };
237 
239  UnwrappedLineNode() : Tok(nullptr) {}
241 
244 };
245 
246 inline UnwrappedLine::UnwrappedLine() : Level(0), InPPDirective(false),
247  MustBeDeclaration(false), MatchingOpeningBlockLineIndex(kInvalidIndex) {}
248 
249 } // end namespace format
250 } // end namespace clang
251 
252 #endif
SmallVector< UnwrappedLine, 0 > Children
UnwrappedLineParser(const FormatStyle &Style, const AdditionalKeywords &Keywords, ArrayRef< FormatToken * > Tokens, UnwrappedLineConsumer &Callback)
virtual void consumeUnwrappedLine(const UnwrappedLine &Line)=0
unsigned Level
The indent level of the UnwrappedLine.
An unwrapped line is a sequence of Token, that we would like to put on a single line if there was no ...
std::list< UnwrappedLineNode > Tokens
The Tokens comprising this UnwrappedLine.
static const size_t kInvalidIndex
bool InPPDirective
Whether this UnwrappedLine is part of a preprocessor directive.
A wrapper around a Token storing information about the whitespace characters preceding it...
Definition: FormatToken.h:119
Defines the clang::IdentifierInfo, clang::IdentifierTable, and clang::Selector interfaces.
#define false
Definition: stdbool.h:33
AnnotatedLine & Line
Various functions to configurably format source code.
size_t MatchingOpeningBlockLineIndex
If this UnwrappedLine closes a block in a sequence of lines, MatchingOpeningBlockLineIndex stores the...
Encapsulates keywords that are context sensitive or for languages not properly supported by Clang's l...
Definition: FormatToken.h:621
TokenKind
Provides a simple uniform namespace for tokens from all C languages.
Definition: TokenKinds.h:25
The FormatStyle is used to configure the formatting to follow specific guidelines.
Definition: Format.h:46
This file contains the declaration of the FormatToken, a wrapper around Token with additional informa...