lucee.transformer.bytecode.visitor.ForVisitor.java Source code

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Here is the source code for lucee.transformer.bytecode.visitor.ForVisitor.java

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/**
 *
 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either 
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public 
 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 * 
 **/
package lucee.transformer.bytecode.visitor;

import lucee.transformer.bytecode.BytecodeContext;
import lucee.transformer.bytecode.Position;
import lucee.transformer.bytecode.util.ExpressionUtil;
import lucee.transformer.bytecode.util.Types;

import org.objectweb.asm.Label;
import org.objectweb.asm.Opcodes;
import org.objectweb.asm.commons.GeneratorAdapter;

public final class ForVisitor implements Opcodes, LoopVisitor {

    private Label l0 = new Label();
    private Label l1 = new Label();
    private Label l2 = new Label();
    private Label l3 = new Label();
    private int i;
    private Label lend = new Label();
    private Label lbegin = new Label();

    public int visitBegin(GeneratorAdapter adapter, int start, boolean isLocal) {
        adapter.visitLabel(l0);

        forInit(adapter, start, isLocal);

        adapter.visitLabel(l1);
        adapter.visitJumpInsn(GOTO, l2);
        adapter.visitLabel(l3);

        return i;
    }

    public void visitEnd(BytecodeContext bc, int end, boolean isLocal, Position startline) {
        GeneratorAdapter adapter = bc.getAdapter();

        adapter.visitLabel(lbegin);
        forUpdate(adapter);

        ExpressionUtil.visitLine(bc, startline);
        adapter.visitLabel(l2);
        adapter.visitVarInsn(ILOAD, i);

        if (isLocal)
            adapter.loadLocal(end);
        else
            adapter.push(end);
        adapter.visitJumpInsn(IF_ICMPLE, l3);

        adapter.visitLabel(lend);

        //adapter.visitLocalVariable("i", "I", null, l1, lend, i);

    }

    private void forUpdate(GeneratorAdapter adapter) {
        adapter.visitIincInsn(i, 1);
    }

    private void forInit(GeneratorAdapter adapter, int start, boolean isLocal) {
        i = adapter.newLocal(Types.INT_VALUE);
        if (isLocal)
            adapter.loadLocal(start);
        else
            adapter.push(start);
        adapter.visitVarInsn(ISTORE, i);
    }

    /**
     *
     * @see lucee.transformer.bytecode.visitor.LoopVisitor#visitContinue(org.objectweb.asm.commons.GeneratorAdapter)
     */
    public void visitContinue(BytecodeContext bc) {
        bc.getAdapter().visitJumpInsn(Opcodes.GOTO, lbegin);
    }

    /**
     *
     * @see lucee.transformer.bytecode.visitor.LoopVisitor#visitBreak(org.objectweb.asm.commons.GeneratorAdapter)
     */
    public void visitBreak(BytecodeContext bc) {
        bc.getAdapter().visitJumpInsn(Opcodes.GOTO, lend);
    }

    /**
     *
     * @see lucee.transformer.bytecode.visitor.LoopVisitor#getContinueLabel()
     */
    public Label getContinueLabel() {
        return lbegin;
    }

    /**
     *
     * @see lucee.transformer.bytecode.visitor.LoopVisitor#getBreakLabel()
     */
    public Label getBreakLabel() {
        return lend;
    }
}