external/bsd/llvm/dist/clang/lib/Format/UnwrappedLineParser.h

   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
  25 namespace clang {
  26 namespace format {
  27
  28 struct 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.
  36 struct 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
  52 class UnwrappedLineConsumer {
  53 public:
  54   virtual ~UnwrappedLineConsumer() {}
  55   virtual void consumeUnwrappedLine(const UnwrappedLine &Line) = 0;
  56   virtual void finishRun() = 0;
  57 };
  58
  59 class FormatTokenSource;
  60
  61 class UnwrappedLineParser {
  62 public:
  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
  71 private:
  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 parseAccessSpecifier();
  99   void parseEnum();
 100   void parseJavaEnumBody();
 101   void parseRecord();
 102   void parseObjCProtocolList();
 103   void parseObjCUntilAtEnd();
 104   void parseObjCInterfaceOrImplementation();
 105   void parseObjCProtocol();
 106   bool tryToParseLambda();
 107   bool tryToParseLambdaIntroducer();
 108   void tryToParseJSFunction();
 109   void addUnwrappedLine();
 110   bool eof() const;
 111   void nextToken();
 112   void readToken();
 113   void flushComments(bool NewlineBeforeNext);
 114   void pushToken(FormatToken *Tok);
 115   void calculateBraceTypes();
 116
 117   // Marks a conditional compilation edge (for example, an '#if', '#ifdef',
 118   // '#else' or merge conflict marker). If 'Unreachable' is true, assumes
 119   // this branch either cannot be taken (for example '#if false'), or should
 120   // not be taken in this round.
 121   void conditionalCompilationCondition(bool Unreachable);
 122   void conditionalCompilationStart(bool Unreachable);
 123   void conditionalCompilationAlternative();
 124   void conditionalCompilationEnd();
 125
 126   bool isOnNewLine(const FormatToken &FormatTok);
 127
 128   // FIXME: We are constantly running into bugs where Line.Level is incorrectly
 129   // subtracted from beyond 0. Introduce a method to subtract from Line.Level
 130   // and use that everywhere in the Parser.
 131   std::unique_ptr<UnwrappedLine> Line;
 132
 133   // Comments are sorted into unwrapped lines by whether they are in the same
 134   // line as the previous token, or not. If not, they belong to the next token.
 135   // Since the next token might already be in a new unwrapped line, we need to
 136   // store the comments belonging to that token.
 137   SmallVector<FormatToken *, 1> CommentsBeforeNextToken;
 138   FormatToken *FormatTok;
 139   bool MustBreakBeforeNextToken;
 140
 141   // The parsed lines. Only added to through \c CurrentLines.
 142   SmallVector<UnwrappedLine, 8> Lines;
 143
 144   // Preprocessor directives are parsed out-of-order from other unwrapped lines.
 145   // Thus, we need to keep a list of preprocessor directives to be reported
 146   // after an unwarpped line that has been started was finished.
 147   SmallVector<UnwrappedLine, 4> PreprocessorDirectives;
 148
 149   // New unwrapped lines are added via CurrentLines.
 150   // Usually points to \c &Lines. While parsing a preprocessor directive when
 151   // there is an unfinished previous unwrapped line, will point to
 152   // \c &PreprocessorDirectives.
 153   SmallVectorImpl<UnwrappedLine> *CurrentLines;
 154
 155   // We store for each line whether it must be a declaration depending on
 156   // whether we are in a compound statement or not.
 157   std::vector<bool> DeclarationScopeStack;
 158
 159   // Will be true if we encounter an error that leads to possibily incorrect
 160   // indentation levels.
 161   bool StructuralError;
 162
 163   const FormatStyle &Style;
 164   const AdditionalKeywords &Keywords;
 165
 166   FormatTokenSource *Tokens;
 167   UnwrappedLineConsumer &Callback;
 168
 169   // FIXME: This is a temporary measure until we have reworked the ownership
 170   // of the format tokens. The goal is to have the actual tokens created and
 171   // owned outside of and handed into the UnwrappedLineParser.
 172   ArrayRef<FormatToken *> AllTokens;
 173
 174   // Represents preprocessor branch type, so we can find matching
 175   // #if/#else/#endif directives.
 176   enum PPBranchKind {
 177     PP_Conditional, // Any #if, #ifdef, #ifndef, #elif, block outside #if 0
 178     PP_Unreachable  // #if 0 or a conditional preprocessor block inside #if 0
 179   };
 180
 181   // Keeps a stack of currently active preprocessor branching directives.
 182   SmallVector<PPBranchKind, 16> PPStack;
 183
 184   // The \c UnwrappedLineParser re-parses the code for each combination
 185   // of preprocessor branches that can be taken.
 186   // To that end, we take the same branch (#if, #else, or one of the #elif
 187   // branches) for each nesting level of preprocessor branches.
 188   // \c PPBranchLevel stores the current nesting level of preprocessor
 189   // branches during one pass over the code.
 190   int PPBranchLevel;
 191
 192   // Contains the current branch (#if, #else or one of the #elif branches)
 193   // for each nesting level.
 194   SmallVector<int, 8> PPLevelBranchIndex;
 195
 196   // Contains the maximum number of branches at each nesting level.
 197   SmallVector<int, 8> PPLevelBranchCount;
 198
 199   // Contains the number of branches per nesting level we are currently
 200   // in while parsing a preprocessor branch sequence.
 201   // This is used to update PPLevelBranchCount at the end of a branch
 202   // sequence.
 203   std::stack<int> PPChainBranchIndex;
 204
 205   friend class ScopedLineState;
 206   friend class CompoundStatementIndenter;
 207 };
 208
 209 struct UnwrappedLineNode {
 210   UnwrappedLineNode() : Tok(nullptr) {}
 211   UnwrappedLineNode(FormatToken *Tok) : Tok(Tok) {}
 212
 213   FormatToken *Tok;
 214   SmallVector<UnwrappedLine, 0> Children;
 215 };
 216
 217 inline UnwrappedLine::UnwrappedLine()
 218     : Level(0), InPPDirective(false), MustBeDeclaration(false) {}
 219
 220 } // end namespace format
 221 } // end namespace clang
 222
 223 #endif