/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * This file is part of SimpleC.                                   *
 * See the file "SimpleC-LICENSE" for Copyright information and    *
 * the terms and conditions for copying, distribution and          *
 * modification of SimpleC.                                        *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

package org.sablecc.simplec;


import java.util.*;
import org.sablecc.simplec.node.*;
import java.util.*;
import java.util.Map.Entry;

class PointsTo 
{
    Start ast;
    Declarations declarations;

    Hashtable variables = new Hashtable(1);

    PointsTo(Start ast, Declarations declarations)
    {
        this.ast = ast;
        this.declarations = declarations;

        initialize();
        new PointsToAnalysis(this);
    }

    private void initialize()
    {
        // for all function declarations
        for(Iterator i = declarations.function_declarations.iterator(); i.hasNext();)
        {
            TIdentifier id = (TIdentifier) i.next();

            // if there is no function definition
            if(declarations.find_fct_def.get(id.getText()) == null)
            {
                Ref ref = new Ref();
                ref.lam = new Variable(new Lam());

                // f = Ref(bottom, lam)
                variables.put(id, new Variable(ref));
            }
        }

        // for all global variables
        for(Iterator i = declarations.global_variables.iterator(); i.hasNext();)
        {
            TIdentifier id = (TIdentifier) i.next();

            // v = Ref(bottom, bottom)
            variables.put(id, new Variable(new Ref()));
        }

        // for all function definitions
        for(Iterator i = declarations.function_definitions.iterator(); i.hasNext();)
        {
            TIdentifier fdef = (TIdentifier) i.next();

            // for all local variables
            for(Iterator j = ((LinkedList) declarations.local_variables.get(fdef)).iterator(); j.hasNext();)
            {
                TIdentifier id = (TIdentifier) j.next();

                // v = Ref(bottom, bottom)
                variables.put(id, new Variable(new Ref()));
            }

            Lam lam = new Lam();

            // for all parameters
            for(Iterator j = ((LinkedList) declarations.parameters.get(fdef)).iterator(); j.hasNext();)
            {
                TIdentifier id = (TIdentifier) j.next();

                Variable var = new Variable(new Ref());

                // p = Ref(bottom, bottom)
                variables.put(id, var);

                // Lam(..., Type(param(i)), ...)
                lam.args.add(var);
            }

            Ref ref = new Ref();
            ref.lam = new Variable(lam);

            variables.put(fdef, new Variable(ref));
        }
    }

    public String toString()
    {
        TreeMap tbl = new TreeMap(IntegerComparator.instance);

        for(Enumeration e = variables.keys(); e.hasMoreElements();)
        {
            Object node = e.nextElement();
            Integer var = new Integer(((Variable) variables.get(node)).ecr().number);

            if(tbl.get(var) == null)
            {
                tbl.put(var, new LinkedList());
            }

            ((LinkedList) tbl.get(var)).add(node);
        }

        StringBuffer s = new StringBuffer();

        for(Iterator e = tbl.entrySet().iterator(); e.hasNext(); )
        {
            Map.Entry entry = (Map.Entry) e.next();

            Integer var = (Integer) entry.getKey();
            LinkedList list = (LinkedList) entry.getValue();

            boolean comma = false;
            for(Iterator i = list.iterator(); i.hasNext();)
            {
                TIdentifier id = (TIdentifier) i.next();

                if(comma)
                {
                    s.append(",");
                }
                else
                {
                    comma = true;
                }

                s.append(id.getText());
            }

            s.append(" : T" + var);
            s.append(System.getProperty("line.separator"));
        }

        for(Iterator i = Variable.variables.iterator(); i.hasNext();)
        {
            Variable var = (Variable) i.next();

            if((var == var.ecr()) &&
                (var.type != Bottom.instance))
            {
                s.append(var);
                s.append(System.getProperty("line.separator"));
            }
        }

        return s.toString();
    }
}