path: root/lib/Format/TokenAnnotator.cpp

//===--- TokenAnnotator.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 implements a token annotator, i.e. creates
/// \c AnnotatedTokens out of \c FormatTokens with required extra information.
///
//===----------------------------------------------------------------------===//

#include "TokenAnnotator.h"
#include "clang/Basic/SourceManager.h"
#include "clang/Lex/Lexer.h"

namespace clang {
namespace format {

static bool isUnaryOperator(const AnnotatedToken &Tok) {
  switch (Tok.FormatTok.Tok.getKind()) {
  case tok::plus:
  case tok::plusplus:
  case tok::minus:
  case tok::minusminus:
  case tok::exclaim:
  case tok::tilde:
  case tok::kw_sizeof:
  case tok::kw_alignof:
    return true;
  default:
    return false;
  }
}

static bool isBinaryOperator(const AnnotatedToken &Tok) {
  // Comma is a binary operator, but does not behave as such wrt. formatting.
  return getPrecedence(Tok) > prec::Comma;
}

// Returns the previous token ignoring comments.
static AnnotatedToken *getPreviousToken(AnnotatedToken &Tok) {
  AnnotatedToken *PrevToken = Tok.Parent;
  while (PrevToken != NULL && PrevToken->is(tok::comment))
    PrevToken = PrevToken->Parent;
  return PrevToken;
}
static const AnnotatedToken *getPreviousToken(const AnnotatedToken &Tok) {
  return getPreviousToken(const_cast<AnnotatedToken &>(Tok));
}

static bool isTrailingComment(AnnotatedToken *Tok) {
  return Tok != NULL && Tok->is(tok::comment) &&
         (Tok->Children.empty() ||
          Tok->Children[0].FormatTok.NewlinesBefore > 0);
}

// Returns the next token ignoring comments.
static const AnnotatedToken *getNextToken(const AnnotatedToken &Tok) {
  if (Tok.Children.empty())
    return NULL;
  const AnnotatedToken *NextToken = &Tok.Children[0];
  while (NextToken->is(tok::comment)) {
    if (NextToken->Children.empty())
      return NULL;
    NextToken = &NextToken->Children[0];
  }
  return NextToken;
}

/// \brief A parser that gathers additional information about tokens.
///
/// The \c TokenAnnotator tries to matches parenthesis and square brakets and
/// store a parenthesis levels. It also tries to resolve matching "<" and ">"
/// into template parameter lists.
class AnnotatingParser {
public:
  AnnotatingParser(SourceManager &SourceMgr, Lexer &Lex, AnnotatedLine &Line,
                   IdentifierInfo &Ident_in)
      : SourceMgr(SourceMgr), Lex(Lex), Line(Line), CurrentToken(&Line.First),
        KeywordVirtualFound(false), Ident_in(Ident_in) {
    Contexts.push_back(Context(1, /*IsExpression=*/ false));
    Contexts.back().LookForFunctionName = Line.MustBeDeclaration;
  }

private:
  bool parseAngle() {
    if (CurrentToken == NULL)
      return false;
    ScopedContextCreator ContextCreator(*this, 10);
    AnnotatedToken *Left = CurrentToken->Parent;
    Contexts.back().IsExpression = false;
    while (CurrentToken != NULL) {
      if (CurrentToken->is(tok::greater)) {
        Left->MatchingParen = CurrentToken;
        CurrentToken->MatchingParen = Left;
        CurrentToken->Type = TT_TemplateCloser;
        next();
        return true;
      }
      if (CurrentToken->is(tok::r_paren) || CurrentToken