clang-1/lib/Parse/ParseExprCXX.cpp

106 строки
3.6 KiB
C++

//===--- ParseExprCXX.cpp - C++ Expression Parsing ------------------------===//
//
// 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 Expression parsing implementation for C++.
//
//===----------------------------------------------------------------------===//
#include "clang/Basic/Diagnostic.h"
#include "clang/Parse/Parser.h"
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.isNot(tok::l_paren)) {
Diag(Tok, diag::err_expected_lparen_after, CastName);
return ExprResult(true);
}
ExprResult Result = ParseSimpleParenExpression(RParenLoc);
if (!Result.isInvalid)
Result = Actions.ActOnCXXCasts(OpLoc, Kind,
LAngleBracketLoc, CastTy, RAngleBracketLoc,
LParenLoc, Result.Val, RParenLoc);
return Result;
}
/// ParseCXXBoolLiteral - This handles the C++ Boolean literals.
///
/// boolean-literal: [C++ 2.13.5]
/// 'true'
/// 'false'
Parser::ExprResult Parser::ParseCXXBoolLiteral() {
tok::TokenKind Kind = Tok.getKind();
return Actions.ActOnCXXBoolLiteral(ConsumeToken(), Kind);
}
/// ParseThrowExpression - This handles the C++ throw expression.
///
/// throw-expression: [C++ 15]
/// 'throw' assignment-expression[opt]
Parser::ExprResult Parser::ParseThrowExpression() {
assert(Tok.is(tok::kw_throw) && "Not throw!");
SourceLocation ThrowLoc = ConsumeToken(); // Eat the throw token.
// If the current token isn't the start of an assignment-expression,
// then the expression is not present. This handles things like:
// "C ? throw : (void)42", which is crazy but legal.
switch (Tok.getKind()) { // FIXME: move this predicate somewhere common.
case tok::semi:
case tok::r_paren:
case tok::r_square:
case tok::r_brace:
case tok::colon:
case tok::comma:
return Actions.ActOnCXXThrow(ThrowLoc);
default:
ExprResult Expr = ParseAssignmentExpression();
if (Expr.isInvalid) return Expr;
return Actions.ActOnCXXThrow(ThrowLoc, Expr.Val);
}
}