path: root/lib/Format/UnwrappedLineParser.cpp

//===--- UnwrappedLineParser.cpp - Format C++ code ------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
///
/// \file
/// \brief This file contains the implementation of the UnwrappedLineParser,
/// which turns a stream of tokens into UnwrappedLines.
///
//===----------------------------------------------------------------------===//

#define DEBUG_TYPE "format-parser"

#include "UnwrappedLineParser.h"
#include "clang/Basic/Diagnostic.h"
#include "llvm/Support/Debug.h"

namespace clang {
namespace format {

class ScopedDeclarationState {
public:
  ScopedDeclarationState(UnwrappedLine &Line, std::vector<bool> &Stack,
                         bool MustBeDeclaration)
      : Line(Line), Stack(Stack) {
    Line.MustBeDeclaration = MustBeDeclaration;
    Stack.push_back(MustBeDeclaration);
  }
  ~ScopedDeclarationState() {
    Stack.pop_back();
    if (!Stack.empty())
      Line.MustBeDeclaration = Stack.back();
    else
      Line.MustBeDeclaration = true;
  }
private:
  UnwrappedLine &Line;
  std::vector<bool> &Stack;
};

class ScopedMacroState : public FormatTokenSource {
public:
  ScopedMacroState(UnwrappedLine &Line, FormatTokenSource *&TokenSource,
                   FormatToken &ResetToken, bool &StructuralError)
      : Line(Line), TokenSource(TokenSource), ResetToken(ResetToken),
        PreviousLineLevel(Line.Level), PreviousTokenSource(TokenSource),
        StructuralError(StructuralError),
        PreviousStructuralError(StructuralError) {
    TokenSource = this;
    Line.Level = 0;
    Line.InPPDirective = true;
  }

  ~ScopedMacroState() {
    TokenSource = PreviousTokenSource;
    ResetToken = Token;
    Line.InPPDirective = false;
    Line.Level = PreviousLineLevel;
    StructuralError = PreviousStructuralError;
  }

  virtual FormatToken getNextToken() {
    // The \c UnwrappedLineParser guards against this by never calling
    // \c getNextToken() after it has encountered the first eof token.
    assert(!eof());
    Token = PreviousTokenSource->getNextToken();
    if (eof())
      return createEOF();
    return Token;
  }

private:
  bool eof() { return Token.HasUnescapedNewline; }

  FormatToken createEOF() {
    FormatToken FormatTok;
    FormatTok.Tok.startToken();
    FormatTok.Tok.setKind(tok::eof);
    return FormatTok;
  }

  UnwrappedLine &Line;
  FormatTokenSource *&TokenSource;
  FormatToken &ResetToken;
  unsigned PreviousLineLevel;
  FormatTokenSource *PreviousTokenSource;
  bool &StructuralError;
  bool PreviousStructuralError;

  FormatToken Token;
};

class ScopedLineState {
public:
  ScopedLineState(UnwrappedLineParser &Parser,
                  bool SwitchToPreprocessorLines = false)
      : Parser(Parser), SwitchToPreprocessorLines(SwitchToPreprocessorLines) {
    if (SwitchToPreprocessorLines)
      Parser.CurrentLines = &Parser.PreprocessorDirectives;
    PreBlockLine = Parser.Line.take();
    Parser.Line.reset(new UnwrappedLine());
    Parser.Line->Level = PreBlockLine->Level;
    Parser.Line->InPPDirective = PreBlockLine->InPPDirective;
  }

  ~ScopedLineState() {
    if (!Parser.Line->Tokens.empty()) {
      Parser.addUnwrappedLine();
    }
    assert(Parser.Line->Tokens.empty());
    Parser.Line.reset(PreBlockLine);
    Parser.MustBreakBeforeNextToken = true;
    if (SwitchToPreprocessorLines)
      Parser.CurrentLines = &Parser.Lines;
  }

private:
  UnwrappedLineParser &Parser;
  const bool SwitchToPreprocessorLines;

  UnwrappedLine *PreBlockLine;
};

UnwrappedLineParser::UnwrappedLineParser(
    clang::DiagnosticsEngine &Diag, const FormatStyle &Style,
    FormatTokenSource &Tokens, UnwrappedLineConsumer &Callback)
    : Line(new UnwrappedLine), MustBreakBeforeNextToken(false),
      CurrentLines(&Lines), StructuralError(false), Diag(Diag), Style(Style),
      Tokens(&Tokens), Callback(Callback) {}

bool UnwrappedLineParser::parse() {
  DEBUG(llvm::dbgs() << "----\n");
  readToken();
  parseFile();
  for (std::vector<UnwrappedLine>::iterator I = Lines.begin(), E = Lines.end();
       I != E; ++I) {
    Callback.consumeUnwrappedLine(*I);
  }

  // Create line with eof token.
  pushToken(FormatTok);
  Callback.consumeUnwrappedLine(*Line);
  return StructuralError;
}

void UnwrappedLineParser::parseFile() {
  ScopedDeclarationState DeclarationState(
      *Line, DeclarationScopeStack,
      /*MustBeDeclaration=*/ !Line->InPPDirective);
  parseLevel(/*HasOpeningBrace=*/ false);
  // Make sure to format the remaining tokens.
  flushComments(true);
  addUnwrappedLine();
}

void UnwrappedLineParser::parseLevel(bool HasOpeningBrace) {
  do </