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"
20#include "clang/Basic/IdentifierTable.h"
21#include "clang/Format/Format.h"
22#include <list>
23#include <stack>
24
25namespace clang {
26namespace format {
27
28struct UnwrappedLineNode;
29
30/// \brief An unwrapped line is a sequence of \c Token, that we would like to
31/// put on a single line if there was no column limit.
32///
33/// This is used as a main interface between the \c UnwrappedLineParser and the
34/// \c UnwrappedLineFormatter. The key property is that changing the formatting
35/// within an unwrapped line does not affect any other unwrapped lines.
36struct UnwrappedLine {
37  UnwrappedLine();
38
39  // FIXME: Don't use std::list here.
40  /// \brief The \c Tokens comprising this \c UnwrappedLine.
41  std::list<UnwrappedLineNode> Tokens;
42
43  /// \brief The indent level of the \c UnwrappedLine.
44  unsigned Level;
45
46  /// \brief Whether this \c UnwrappedLine is part of a preprocessor directive.
47  bool InPPDirective;
48
49  bool MustBeDeclaration;
50};
51
52class UnwrappedLineConsumer {
53public:
54  virtual ~UnwrappedLineConsumer() {}
55  virtual void consumeUnwrappedLine(const UnwrappedLine &Line) = 0;
56  virtual void finishRun() = 0;
57};
58
59class FormatTokenSource;
60
61class UnwrappedLineParser {
62public:
63  UnwrappedLineParser(const FormatStyle &Style,
64                      const AdditionalKeywords &Keywords,
65                      ArrayRef<FormatToken *> Tokens,
66                      UnwrappedLineConsumer &Callback);
67
68  void parse();
69
70private:
71  void reset();
72  void parseFile();
73  void parseLevel(bool HasOpeningBrace);
74  void parseBlock(bool MustBeDeclaration, bool AddLevel = true,
75                  bool MunchSemi = true);
76  void parseChildBlock();
77  void parsePPDirective();
78  void parsePPDefine();
79  void parsePPIf(bool IfDef);
80  void parsePPElIf();
81  void parsePPElse();
82  void parsePPEndIf();
83  void parsePPUnknown();
84  void parseStructuralElement();
85  bool tryToParseBracedList();
86  bool parseBracedList(bool ContinueOnSemicolons = false);
87  void parseParens();
88  void parseSquare();
89  void parseIfThenElse();
90  void parseTryCatch();
91  void parseForOrWhileLoop();
92  void parseDoWhile();
93  void parseLabel();
94  void parseCaseLabel();
95  void parseSwitch();
96  void parseNamespace();
97  void parseNew();
98  void parseAccessSpecifier();
99  bool parseEnum();
100  void parseJavaEnumBody();
101  void parseRecord();
102  void parseObjCProtocolList();
103  void parseObjCUntilAtEnd();
104  void parseObjCInterfaceOrImplementation();
105  void parseObjCProtocol();
106  void parseJavaScriptEs6ImportExport();
107  bool tryToParseLambda();
108  bool tryToParseLambdaIntroducer();
109  void tryToParseJSFunction();
110  void addUnwrappedLine();
111  bool eof() const;
112  void nextToken();
113  const FormatToken *getPreviousToken();
114  void readToken();
115  void flushComments(bool NewlineBeforeNext);
116  void pushToken(FormatToken *Tok);
117  void calculateBraceTypes(bool ExpectClassBody = false);
118
119  // Marks a conditional compilation edge (for example, an '#if', '#ifdef',
120  // '#else' or merge conflict marker). If 'Unreachable' is true, assumes
121  // this branch either cannot be taken (for example '#if false'), or should
122  // not be taken in this round.
123  void conditionalCompilationCondition(bool Unreachable);
124  void conditionalCompilationStart(bool Unreachable);
125  void conditionalCompilationAlternative();
126  void conditionalCompilationEnd();
127
128  bool isOnNewLine(const FormatToken &FormatTok);
129
130  // FIXME: We are constantly running into bugs where Line.Level is incorrectly
131  // subtracted from beyond 0. Introduce a method to subtract from Line.Level
132  // and use that everywhere in the Parser.
133  std::unique_ptr<UnwrappedLine> Line;
134
135  // Comments are sorted into unwrapped lines by whether they are in the same
136  // line as the previous token, or not. If not, they belong to the next token.
137  // Since the next token might already be in a new unwrapped line, we need to
138  // store the comments belonging to that token.
139  SmallVector<FormatToken *, 1> CommentsBeforeNextToken;
140  FormatToken *FormatTok;
141  bool MustBreakBeforeNextToken;
142
143  // The parsed lines. Only added to through \c CurrentLines.
144  SmallVector<UnwrappedLine, 8> Lines;
145
146  // Preprocessor directives are parsed out-of-order from other unwrapped lines.
147  // Thus, we need to keep a list of preprocessor directives to be reported
148  // after an unwarpped line that has been started was finished.
149  SmallVector<UnwrappedLine, 4> PreprocessorDirectives;
150
151  // New unwrapped lines are added via CurrentLines.
152  // Usually points to \c &Lines. While parsing a preprocessor directive when
153  // there is an unfinished previous unwrapped line, will point to
154  // \c &PreprocessorDirectives.
155  SmallVectorImpl<UnwrappedLine> *CurrentLines;
156
157  // We store for each line whether it must be a declaration depending on
158  // whether we are in a compound statement or not.
159  std::vector<bool> DeclarationScopeStack;
160
161  const FormatStyle &Style;
162  const AdditionalKeywords &Keywords;
163
164  FormatTokenSource *Tokens;
165  UnwrappedLineConsumer &Callback;
166
167  // FIXME: This is a temporary measure until we have reworked the ownership
168  // of the format tokens. The goal is to have the actual tokens created and
169  // owned outside of and handed into the UnwrappedLineParser.
170  ArrayRef<FormatToken *> AllTokens;
171
172  // Represents preprocessor branch type, so we can find matching
173  // #if/#else/#endif directives.
174  enum PPBranchKind {
175    PP_Conditional, // Any #if, #ifdef, #ifndef, #elif, block outside #if 0
176    PP_Unreachable  // #if 0 or a conditional preprocessor block inside #if 0
177  };
178
179  // Keeps a stack of currently active preprocessor branching directives.
180  SmallVector<PPBranchKind, 16> PPStack;
181
182  // The \c UnwrappedLineParser re-parses the code for each combination
183  // of preprocessor branches that can be taken.
184  // To that end, we take the same branch (#if, #else, or one of the #elif
185  // branches) for each nesting level of preprocessor branches.
186  // \c PPBranchLevel stores the current nesting level of preprocessor
187  // branches during one pass over the code.
188  int PPBranchLevel;
189
190  // Contains the current branch (#if, #else or one of the #elif branches)
191  // for each nesting level.
192  SmallVector<int, 8> PPLevelBranchIndex;
193
194  // Contains the maximum number of branches at each nesting level.
195  SmallVector<int, 8> PPLevelBranchCount;
196
197  // Contains the number of branches per nesting level we are currently
198  // in while parsing a preprocessor branch sequence.
199  // This is used to update PPLevelBranchCount at the end of a branch
200  // sequence.
201  std::stack<int> PPChainBranchIndex;
202
203  friend class ScopedLineState;
204  friend class CompoundStatementIndenter;
205};
206
207struct UnwrappedLineNode {
208  UnwrappedLineNode() : Tok(nullptr) {}
209  UnwrappedLineNode(FormatToken *Tok) : Tok(Tok) {}
210
211  FormatToken *Tok;
212  SmallVector<UnwrappedLine, 0> Children;
213};
214
215inline UnwrappedLine::UnwrappedLine()
216    : Level(0), InPPDirective(false), MustBeDeclaration(false) {}
217
218} // end namespace format
219} // end namespace clang
220
221#endif
222