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 readTokenWithJavaScriptASI();
85  void parseStructuralElement();
86  bool tryToParseBracedList();
87  bool parseBracedList(bool ContinueOnSemicolons = false);
88  void parseParens();
89  void parseSquare();
90  void parseIfThenElse();
91  void parseTryCatch();
92  void parseForOrWhileLoop();
93  void parseDoWhile();
94  void parseLabel();
95  void parseCaseLabel();
96  void parseSwitch();
97  void parseNamespace();
98  void parseNew();
99  void parseAccessSpecifier();
100  bool parseEnum();
101  void parseJavaEnumBody();
102  void parseRecord();
103  void parseObjCProtocolList();
104  void parseObjCUntilAtEnd();
105  void parseObjCInterfaceOrImplementation();
106  void parseObjCProtocol();
107  void parseJavaScriptEs6ImportExport();
108  bool tryToParseLambda();
109  bool tryToParseLambdaIntroducer();
110  void tryToParseJSFunction();
111  void addUnwrappedLine();
112  bool eof() const;
113  void nextToken();
114  const FormatToken *getPreviousToken();
115  void readToken();
116  void flushComments(bool NewlineBeforeNext);
117  void pushToken(FormatToken *Tok);
118  void calculateBraceTypes(bool ExpectClassBody = false);
119
120  // Marks a conditional compilation edge (for example, an '#if', '#ifdef',
121  // '#else' or merge conflict marker). If 'Unreachable' is true, assumes
122  // this branch either cannot be taken (for example '#if false'), or should
123  // not be taken in this round.
124  void conditionalCompilationCondition(bool Unreachable);
125  void conditionalCompilationStart(bool Unreachable);
126  void conditionalCompilationAlternative();
127  void conditionalCompilationEnd();
128
129  bool isOnNewLine(const FormatToken &FormatTok);
130
131  // FIXME: We are constantly running into bugs where Line.Level is incorrectly
132  // subtracted from beyond 0. Introduce a method to subtract from Line.Level
133  // and use that everywhere in the Parser.
134  std::unique_ptr<UnwrappedLine> Line;
135
136  // Comments are sorted into unwrapped lines by whether they are in the same
137  // line as the previous token, or not. If not, they belong to the next token.
138  // Since the next token might already be in a new unwrapped line, we need to
139  // store the comments belonging to that token.
140  SmallVector<FormatToken *, 1> CommentsBeforeNextToken;
141  FormatToken *FormatTok;
142  bool MustBreakBeforeNextToken;
143
144  // The parsed lines. Only added to through \c CurrentLines.
145  SmallVector<UnwrappedLine, 8> Lines;
146
147  // Preprocessor directives are parsed out-of-order from other unwrapped lines.
148  // Thus, we need to keep a list of preprocessor directives to be reported
149  // after an unwarpped line that has been started was finished.
150  SmallVector<UnwrappedLine, 4> PreprocessorDirectives;
151
152  // New unwrapped lines are added via CurrentLines.
153  // Usually points to \c &Lines. While parsing a preprocessor directive when
154  // there is an unfinished previous unwrapped line, will point to
155  // \c &PreprocessorDirectives.
156  SmallVectorImpl<UnwrappedLine> *CurrentLines;
157
158  // We store for each line whether it must be a declaration depending on
159  // whether we are in a compound statement or not.
160  std::vector<bool> DeclarationScopeStack;
161
162  const FormatStyle &Style;
163  const AdditionalKeywords &Keywords;
164
165  FormatTokenSource *Tokens;
166  UnwrappedLineConsumer &Callback;
167
168  // FIXME: This is a temporary measure until we have reworked the ownership
169  // of the format tokens. The goal is to have the actual tokens created and
170  // owned outside of and handed into the UnwrappedLineParser.
171  ArrayRef<FormatToken *> AllTokens;
172
173  // Represents preprocessor branch type, so we can find matching
174  // #if/#else/#endif directives.
175  enum PPBranchKind {
176    PP_Conditional, // Any #if, #ifdef, #ifndef, #elif, block outside #if 0
177    PP_Unreachable  // #if 0 or a conditional preprocessor block inside #if 0
178  };
179
180  // Keeps a stack of currently active preprocessor branching directives.
181  SmallVector<PPBranchKind, 16> PPStack;
182
183  // The \c UnwrappedLineParser re-parses the code for each combination
184  // of preprocessor branches that can be taken.
185  // To that end, we take the same branch (#if, #else, or one of the #elif
186  // branches) for each nesting level of preprocessor branches.
187  // \c PPBranchLevel stores the current nesting level of preprocessor
188  // branches during one pass over the code.
189  int PPBranchLevel;
190
191  // Contains the current branch (#if, #else or one of the #elif branches)
192  // for each nesting level.
193  SmallVector<int, 8> PPLevelBranchIndex;
194
195  // Contains the maximum number of branches at each nesting level.
196  SmallVector<int, 8> PPLevelBranchCount;
197
198  // Contains the number of branches per nesting level we are currently
199  // in while parsing a preprocessor branch sequence.
200  // This is used to update PPLevelBranchCount at the end of a branch
201  // sequence.
202  std::stack<int> PPChainBranchIndex;
203
204  friend class ScopedLineState;
205  friend class CompoundStatementIndenter;
206};
207
208struct UnwrappedLineNode {
209  UnwrappedLineNode() : Tok(nullptr) {}
210  UnwrappedLineNode(FormatToken *Tok) : Tok(Tok) {}
211
212  FormatToken *Tok;
213  SmallVector<UnwrappedLine, 0> Children;
214};
215
216inline UnwrappedLine::UnwrappedLine()
217    : Level(0), InPPDirective(false), MustBeDeclaration(false) {}
218
219} // end namespace format
220} // end namespace clang
221
222#endif
223