Routine.java

/*
  Routine.java

  (c) 2008-2013 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package v9t9.common.asm;

import java.util.Collection;
import java.util.Collections;
import java.util.Set;
import java.util.TreeSet;



/**
 * A routine, i.e. an entry point which is branched to with a return
 * address.
 * @author ejs
 */
public abstract class Routine implements Comparable<Routine> {
	
	private Label mainLabel;
    private TreeSet<Label> labels;
    
    /** Routine goes not exit in an expected way */
    public static final int fUnknownExit = 1;
    /** Routine is part of another routine */
    public static final int fSubroutine = 2;
    public int flags;
    
    protected int dataWords;
    
    public Routine() {
        labels = new TreeSet<Label>();
    }
    
    @Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + ((mainLabel == null) ? 0 : mainLabel.hashCode());
		return result;
	}

	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		final Routine other = (Routine) obj;
		if (mainLabel == null) {
			if (other.mainLabel != null)
				return false;
		} else if (!mainLabel.equals(other.mainLabel))
			return false;
		return true;
	}

	public int compareTo(Routine o) {
    	return mainLabel.compareTo(o.mainLabel);
    }
    
    @Override
    public String toString() {
        return "Routine " + mainLabel;
    }
    abstract public boolean isReturn(IHighLevelInstruction inst);
    
    @Deprecated
    public Block getBlock(Label lab) {
    	return lab.getBlock();
    }

    /**
     * Examine code appearing at the entry of a routine
     */
    abstract public void examineEntryCode();

    /** Get the blocks spanned by the routine.  Requires that the flowgraph info is complete. */
	public Collection<Block> getSpannedBlocks() {
		Collection<Block> spannedBlocks = new TreeSet<Block>();
		if (labels.size() == 1) {
			spannedBlocks = mainLabel.getBlock().getSpannedBlockSet();
		} else {
			for (Label label : labels) {
				spannedBlocks.addAll(label.getBlock().getSpannedBlockSet());
			}
		}
		return Collections.unmodifiableCollection(spannedBlocks);
	}

	/** Get the entry point(s) */
	public Collection<Block> getEntries() {
		Set<Block> blocks = new TreeSet<Block>();
		for (Label label : labels) {
			blocks.add(label.getBlock());
		}
		return blocks;
	}

	public void addEntry(Label label) {
		labels.add(label);
		mainLabel = labels.iterator().next();
	}

	public Label getMainLabel() {
		return mainLabel;
	}
	
	public int getDataWords() {
		return dataWords;
	}

	public Set<Integer> getSpannedPcs() {
		Set<Integer> pcSet = new TreeSet<Integer>();
		for (Block block : getSpannedBlocks()) {
			Set<Integer> blockPcSet = block.getSpannedPcs();
			pcSet.addAll(blockPcSet);
		}
		return pcSet;
	}

}