IfNode.java

package nl.bartpelle.adder.ast;

import nl.bartpelle.adder.AdderCtx;
import nl.bartpelle.adder.Instruction;
import nl.bartpelle.adder.Label;
import nl.bartpelle.adder.enums.Type;

import java.util.List;

/**
 * Created by Bart Pelle on 8/21/2014.
 */
public class IfNode implements AstNode {

	public AstNode condition;
	public AstNode trueArm;
	public AstNode falseArm;

	public IfNode(AstNode condition, AstNode trueArm, AstNode falseArm) {
		this.condition = condition;
		this.trueArm = trueArm;
		this.falseArm = falseArm;
	}

	@Override
	public void dasm() {
		condition.dasm();
		System.out.println("iftrue");
		trueArm.dasm();
		if (falseArm != null) {
			System.out.println("else");
			falseArm.dasm();
		}
	}

	@Override public Type type() {
		return Type.VOID;
	}

	@Override public void encode(List<Instruction> out, AdderCtx ctx) {
		Label ifFalse = Label.unique();
		Label endOfFalse = Label.unique();

		if (condition.type() != Type.BOOL)
			throw new RuntimeException("condition cannot be casted to boolean (type: " + condition.type() + ", condition: " + condition + ")");

		//encodeBranching(condition, ifFalse, endOfFalse, out, ctx);
		condition.encode(out, ctx);

		/* Jump if zero to false */
		Instruction jz = new Instruction(Instruction.Opcode.JZ, 0);
		out.add(jz);
		ifFalse.promises.add((pos) -> jz.i = ctx.cpoolInt(pos));

		trueArm.encode(out, ctx);
		Instruction j = new Instruction(Instruction.Opcode.JMP, 0);
		out.add(j);
		endOfFalse.promises.add((pos) -> j.i = ctx.cpoolInt(pos));

		out.add(ifFalse);
		if (falseArm != null)
			falseArm.encode(out, ctx);
		out.add(endOfFalse);
	}

	private void encodeBranching(AstNode expr, Label ifFalse, Label endOfFalse, List<Instruction> out, AdderCtx ctx) {
		System.out.println("Shit we have " + expr.getClass().getSimpleName());
	}

}