dvander@212: /* vim: set ts=4 sw=4 tw=99 et:
dvander@212:  *
dvander@212:  * Copyright (C) 2012 David Anderson
dvander@212:  *
dvander@212:  * This file is part of SourcePawn.
dvander@212:  *
dvander@212:  * SourcePawn is free software: you can redistribute it and/or modify it under
dvander@212:  * the terms of the GNU General Public License as published by the Free
dvander@212:  * Software Foundation, either version 3 of the License, or (at your option)
dvander@212:  * any later version.
dvander@212:  * 
dvander@212:  * SourcePawn is distributed in the hope that it will be useful, but WITHOUT ANY
dvander@212:  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
dvander@212:  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
dvander@212:  *
dvander@212:  * You should have received a copy of the GNU General Public License along with
dvander@212:  * SourcePawn. If not, see http://www.gnu.org/licenses/.
dvander@212:  */
dvander@212: #include "AST.h"
dvander@212: #include "ConstantEvaluator.h"
dvander@213: #include "../Heap-inl.h"
dvander@213: #include "../Handles-inl.h"
dvander@212: 
dvander@212: using namespace ke;
dvander@212: 
dvander@212: static inline bool
dvander@212: EvaluateBinaryOperation(TokenKind kind, const BoxedPrimitive &left, const BoxedPrimitive &right,
dvander@212:                         BoxedPrimitive *out)
dvander@212: {
dvander@212:     switch (kind) {
dvander@212:       case TOK_PLUS:
dvander@212:         *out = BoxedPrimitive::Int(left.toInt() + right.toInt());
dvander@212:         return true;
dvander@212: 
dvander@212:       case TOK_SHL:
dvander@212:         *out = BoxedPrimitive::Int(left.toInt() << right.toInt());
dvander@212:         return true;
dvander@212: 
dvander@212:       default:
dvander@212:         return false;
dvander@212:     }
dvander@212: }
dvander@212: 
dvander@212: static inline bool
dvander@212: EvaluateUnaryOperation(TokenKind kind, const BoxedPrimitive &inner, BoxedPrimitive *out)
dvander@212: {
dvander@212:   switch (kind) {
dvander@212:     case TOK_MINUS:
dvander@212:       *out = BoxedPrimitive::Int(-inner.toInt());
dvander@212:       return true;
dvander@212: 
dvander@212:     default:
dvander@212:       return false;
dvander@212:   }
dvander@212: }
dvander@212: 
dvander@212: bool
dvander@212: ke::EvaluateForConstant(Expression *expr, BoxedPrimitive *out)
dvander@212: {
dvander@212:     switch (expr->kind()) {
dvander@212:       case AstNode::kBinaryExpression:
dvander@212:       {
dvander@212:         BoxedPrimitive left;
dvander@212:         BoxedPrimitive right;
dvander@212:         BinaryExpression *b = expr->toBinaryExpression();
dvander@212:         if (!EvaluateForConstant(b->left(), &left) ||
dvander@212:             !EvaluateForConstant(b->right(), &right))
dvander@212:         {
dvander@212:             return false;
dvander@212:         }
dvander@212:         return EvaluateBinaryOperation(b->token(), left, right, out);
dvander@212:       }
dvander@212: 
dvander@212:       case AstNode::kUnaryExpression:
dvander@212:       {
dvander@212:         BoxedPrimitive inner;
dvander@212:         UnaryExpression *u = expr->toUnaryExpression();
dvander@212:         if (!EvaluateForConstant(u->expression(), &inner))
dvander@212:             return false;
dvander@212:         return EvaluateUnaryOperation(u->token(), inner, out);
dvander@212:       }
dvander@212: 
dvander@212:       case AstNode::kBooleanLiteral:
dvander@212:         *out = BoxedPrimitive::Int(expr->toBooleanLiteral()->token() == TOK_TRUE ? 1 : 0);
dvander@212:         return true;
dvander@212: 
dvander@212:       case AstNode::kIntegerLiteral:
dvander@212:         *out = BoxedPrimitive::Int(expr->toIntegerLiteral()->value());
dvander@212:         return true;
dvander@212: 
dvander@212:       default:
dvander@212:         return false;
dvander@212:     }
dvander@212: }