clang/Parse/ParseExprCXX.cpp

//===--- ParseExprCXX.cpp - C++ Expression Parsing ------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file was developed by Bill Wendling and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Expression parsing implementation for C++.
//
//===----------------------------------------------------------------------===//

#include "clang/AST/ExprCXX.h"
#include "clang/Basic/Diagnostic.h"
#include "clang/Parse/Parser.h"
using namespace llvm;
using namespace clang;

/// ParseCXXCasts - This handles the various ways to cast expressions to another
/// type.
///
///       postfix-expression: [C++ 5.2p1]
///         'dynamic_cast' '<' type-name '>' '(' expression ')'
///         'static_cast' '<' type-name '>' '(' expression ')'
///         'reinterpret_cast' '<' type-name '>' '(' expression ')'
///         'const_cast' '<' type-name '>' '(' expression ')'
///
Parser::ExprResult Parser::ParseCXXCasts() {
  tok::TokenKind Kind = Tok.getKind();
  const char *CastName = 0;     // For error messages

  switch (Kind) {
  default: assert(0 && "Unknown C++ cast!"); abort();
  case tok::kw_const_cast:       CastName = "const_cast";       break;
  case tok::kw_dynamic_cast:     CastName = "dynamic_cast";     break;
  case tok::kw_reinterpret_cast: CastName = "reinterpret_cast"; break;
  case tok::kw_static_cast:      CastName = "static_cast";      break;
  }

  SourceLocation OpLoc = ConsumeToken();
  SourceLocation LAngleBracketLoc = Tok.getLocation();

  if (ExpectAndConsume(tok::less, diag::err_expected_less_after, CastName))
    return ExprResult(true);

  TypeTy *CastTy = ParseTypeName();
  SourceLocation RAngleBracketLoc = Tok.getLocation();

  if (ExpectAndConsume(tok::greater, diag::err_expected_greater)) {
    Diag(LAngleBracketLoc, diag::err_matching, "<");
    return ExprResult(true);
  }

  SourceLocation LParenLoc = Tok.getLocation(), RParenLoc;

  if (Tok.getKind() != tok::l_paren) {
    Diag(Tok, diag::err_expected_lparen_after, CastName);
    return ExprResult(true);
  }

  ExprResult Result = ParseSimpleParenExpression(RParenLoc);

  if (!Result.isInvalid)
    Result = Actions.ParseCXXCasts(OpLoc, Kind,
                                   LAngleBracketLoc, CastTy, RAngleBracketLoc,
                                   LParenLoc, Result.Val, RParenLoc);

  return Result;
}