path: root/lib/Parse/Parser.cpp

//===--- Parser.cpp - C Language Family Parser ----------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file implements the Parser interfaces.
//
//===----------------------------------------------------------------------===//

#include "clang/Parse/Parser.h"
#include "clang/Parse/ParseDiagnostic.h"
#include "clang/Parse/DeclSpec.h"
#include "clang/Parse/Scope.h"
#include "llvm/Support/raw_ostream.h"
#include "ExtensionRAIIObject.h"
#include "ParsePragma.h"
using namespace clang;

/// \brief A comment handler that passes comments found by the preprocessor
/// to the parser action.
class ActionCommentHandler : public CommentHandler {
  Action &Actions;
  
public:
  explicit ActionCommentHandler(Action &Actions) : Actions(Actions) { }
  
  virtual void HandleComment(Preprocessor &PP, SourceRange Comment) {
    Actions.ActOnComment(Comment);
  }
};

Parser::Parser(Preprocessor &pp, Action &actions)
  : CrashInfo(*this), PP(pp), Actions(actions), Diags(PP.getDiagnostics()), 
    GreaterThanIsOperator(true), TemplateParameterDepth(0) {
  Tok.setKind(tok::eof);
  CurScope = 0;
  NumCachedScopes = 0;
  ParenCount = BracketCount = BraceCount = 0;
  ObjCImpDecl = DeclPtrTy();

  // Add #pragma handlers. These are removed and destroyed in the
  // destructor.
  PackHandler.reset(new
          PragmaPackHandler(&PP.getIdentifierTable().get("pack"), actions));
  PP.AddPragmaHandler(0, PackHandler.get());
      
  UnusedHandler.reset(new
          PragmaUnusedHandler(&PP.getIdentifierTable().get("unused"), actions,
                              *this));
  PP.AddPragmaHandler(0, UnusedHandler.get());

  WeakHandler.reset(new
          PragmaWeakHandler(&PP.getIdentifierTable().get("weak"), actions));
  PP.AddPragmaHandler(0, WeakHandler.get());
      
  CommentHandler.reset(new ActionCommentHandler(actions));
  PP.AddCommentHandler(CommentHandler.get());    
}

/// If a crash happens while the parser is active, print out a line indicating
/// what the current token is.
void PrettyStackTraceParserEntry::print(llvm::raw_ostream &OS) const {
  const Token &Tok = P.getCurToken();
  if (Tok.is(tok::eof)) {
    OS << "<eof> parser at end of file\n";
    return;
  }
  
  if (Tok.getLocation().isInvalid()) {
    OS << "<unknown> parser at unknown location\n";
    return;
  }
  
  const Preprocessor &PP = P.getPreprocessor();
  Tok.getLocation().print(OS, PP.getSourceManager());
  OS << ": current parser token '" << PP.getSpelling(Tok) << "'\n";
}


DiagnosticBuilder Parser::Diag(SourceLocation Loc, unsigned DiagID) {
  return Diags.Report(FullSourceLoc(Loc, PP.getSourceManager()), DiagID);
}

DiagnosticBuilder Parser::Diag(const Token &Tok, unsigned DiagID) {
  return Diag(Tok.getLocation(), DiagID);
}

/// \brief Emits a diagnostic suggesting parentheses surrounding a
/// given range.
///
/// \param Loc The location where we'll emit the diagnostic.
/// \param Loc The kind of diagnostic to emit.
/// \param ParenRange Source range enclosing code that should be parenthesized.
void Parser::SuggestParentheses(SourceLocation Loc, unsigned DK,
                                SourceRange ParenRange) {
  SourceLocation EndLoc = PP.getLocForEndOfToken(ParenRange.getEnd());
  if (!ParenRange.getEnd().isFileID() || EndLoc.isInvalid()) {
    // We can't display the parentheses, so just dig the
    // warning/error and return.
    Diag(Loc, DK);
    return;
  }
    
  Diag(Loc, DK) 
    << CodeModificationHint::CreateInsertion(ParenRange.getBegin(), "(")
    << CodeModificationHint::CreateInsertion(EndLoc, ")");
}

/// MatchRHSPunctuation - For punctuation with a LHS and RHS (e.g. '['/']'),
/// this helper function matches and consumes the specified RHS token if
/// present.  If not present, it emits the specified diagnostic indicating
/// that the parser failed to match the RHS of the token at LHSLoc.  LHSName
/// should be the name of the unmatched LHS token.
SourceLocation Parser::MatchRHSPunctuation(tok::TokenKind RHSTok,
                                           SourceLocation LHSLoc) {

  if (Tok.is(RHSTok))
    return ConsumeAnyToken();

  SourceLocation R = Tok.getLocation();
  const char *LHSName = "unknown";
  diag::kind