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  /// Returns true in case of a structural error.
69  bool parse();
70
71private:
72  void reset();
73  void parseFile();
74  void parseLevel(bool HasOpeningBrace);
75  void parseBlock(bool MustBeDeclaration, bool AddLevel = true,
76                  bool MunchSemi = true);
77  void parseChildBlock();
78  void parsePPDirective();
79  void parsePPDefine();
80  void parsePPIf(bool IfDef);
81  void parsePPElIf();
82  void parsePPElse();
83  void parsePPEndIf();
84  void parsePPUnknown();
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  void 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  void readToken();
115  void flushComments(bool NewlineBeforeNext);
116  void pushToken(FormatToken *Tok);
117  void calculateBraceTypes();
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  // Will be true if we encounter an error that leads to possibily incorrect
162  // indentation levels.
163  bool StructuralError;
164
165  const FormatStyle &Style;
166  const AdditionalKeywords &Keywords;
167
168  FormatTokenSource *Tokens;
169  UnwrappedLineConsumer &Callback;
170
171  // FIXME: This is a temporary measure until we have reworked the ownership
172  // of the format tokens. The goal is to have the actual tokens created and
173  // owned outside of and handed into the UnwrappedLineParser.
174  ArrayRef<FormatToken *> AllTokens;
175
176  // Represents preprocessor branch type, so we can find matching
177  // #if/#else/#endif directives.
178  enum PPBranchKind {
179    PP_Conditional, // Any #if, #ifdef, #ifndef, #elif, block outside #if 0
180    PP_Unreachable  // #if 0 or a conditional preprocessor block inside #if 0
181  };
182
183  // Keeps a stack of currently active preprocessor branching directives.
184  SmallVector<PPBranchKind, 16> PPStack;
185
186  // The \c UnwrappedLineParser re-parses the code for each combination
187  // of preprocessor branches that can be taken.
188  // To that end, we take the same branch (#if, #else, or one of the #elif
189  // branches) for each nesting level of preprocessor branches.
190  // \c PPBranchLevel stores the current nesting level of preprocessor
191  // branches during one pass over the code.
192  int PPBranchLevel;
193
194  // Contains the current branch (#if, #else or one of the #elif branches)
195  // for each nesting level.
196  SmallVector<int, 8> PPLevelBranchIndex;
197
198  // Contains the maximum number of branches at each nesting level.
199  SmallVector<int, 8> PPLevelBranchCount;
200
201  // Contains the number of branches per nesting level we are currently
202  // in while parsing a preprocessor branch sequence.
203  // This is used to update PPLevelBranchCount at the end of a branch
204  // sequence.
205  std::stack<int> PPChainBranchIndex;
206
207  friend class ScopedLineState;
208  friend class CompoundStatementIndenter;
209};
210
211struct UnwrappedLineNode {
212  UnwrappedLineNode() : Tok(nullptr) {}
213  UnwrappedLineNode(FormatToken *Tok) : Tok(Tok) {}
214
215  FormatToken *Tok;
216  SmallVector<UnwrappedLine, 0> Children;
217};
218
219inline UnwrappedLine::UnwrappedLine()
220    : Level(0), InPPDirective(false), MustBeDeclaration(false) {}
221
222} // end namespace format
223} // end namespace clang
224
225#endif
226