package IR.Tree;
import IR.*;
import java.util.*;


public class BuildIR {
    State state;
    public BuildIR(State state) {
	this.state=state;
    }
    public void buildtree() {
	for(Iterator it=state.parsetrees.iterator();it.hasNext();) {
	    ParseNode pn=(ParseNode)it.next();
	    parseFile(pn);
	}
    }

    /** Parse the classes in this file */
    public void parseFile(ParseNode pn) {
	NameDescriptor packages;
	Vector singleimports=new Vector();
	Vector multiimports=new Vector();

	ParseNode ipn=pn.getChild("imports").getChild("import_decls_list");
	if (ipn!=null) {
	    ParseNodeVector pnv=ipn.getChildren();
	    for(int i=0;i<pnv.size();i++) {
		ParseNode pnimport=pnv.elementAt(i);
		NameDescriptor nd=parseName(pnimport.getChild("name"));
		if (isNode(pnimport,"import_single"))
		    singleimports.add(nd);
		else
		    multiimports.add(nd);
	    }
	}
	ParseNode ppn=pn.getChild("packages").getChild("package");
	if (ppn!=null) {
	    packages=parseName(pn.getChild("name"));
	}
	ParseNode tpn=pn.getChild("type_declaration_list");
	if (tpn!=null) {
	    ParseNodeVector pnv=tpn.getChildren();
	    for(int i=0;i<pnv.size();i++) {
		ParseNode type_pn=pnv.elementAt(i);
		if (isEmpty(type_pn)) /* Skip the semicolon */
		    continue;
		if (isNode(type_pn,"class_declaration")) {
		    ClassDescriptor cn=parseTypeDecl(type_pn);
		    state.addClass(cn);
		} else if (isNode(type_pn,"task_declaration")) {
		    TaskDescriptor td=parseTaskDecl(type_pn);
		    state.addTask(td);
		} else {
		    throw new Error(type_pn.getLabel());
		}
	    }
	}
    }

    public TaskDescriptor parseTaskDecl(ParseNode pn) {
	TaskDescriptor td=new TaskDescriptor(pn.getChild("name").getTerminal());
	ParseNode bodyn=pn.getChild("body");
	BlockNode bn=parseBlock(bodyn);
	parseParameterList(td, pn);
	state.addTreeCode(td,bn);
	if (pn.getChild("flag_effects_list")!=null)
	    td.addFlagEffects(parseFlags(pn.getChild("flag_effects_list")));
	return td;
    }

    public Vector parseFlags(ParseNode pn) {
	Vector vfe=new Vector();
	ParseNodeVector pnv=pn.getChildren();
	for(int i=0;i<pnv.size();i++) {
	    ParseNode fn=pnv.elementAt(i);
	    FlagEffects fe=parseFlagEffects(fn);
	    vfe.add(fe);
	}
	return vfe;
    }

    public FlagEffects parseFlagEffects(ParseNode pn) {
	if (isNode(pn,"flag_effect")) {
	    String flagname=pn.getChild("name").getTerminal();
	    FlagEffects fe=new FlagEffects(flagname);
	    if (pn.getChild("flag_list")!=null)
		parseFlagEffect(fe, pn.getChild("flag_list"));
	    if (pn.getChild("tag_list")!=null)
		parseTagEffect(fe, pn.getChild("tag_list"));
	    return fe;
	} else throw new Error();
    }
    
    public void parseTagEffect(FlagEffects fes, ParseNode pn) {
	ParseNodeVector pnv=pn.getChildren();
	for(int i=0;i<pnv.size();i++) {
	    ParseNode pn2=pnv.elementAt(i);
	    boolean status=true;
	    if (isNode(pn2,"not")) {
		status=false;
		pn2=pn2.getChild("name");
	    }
	    String name=pn2.getTerminal();
	    fes.addTagEffect(new TagEffect(name,status));
	}
    }

    public void parseFlagEffect(FlagEffects fes, ParseNode pn) {
	ParseNodeVector pnv=pn.getChildren();
	for(int i=0;i<pnv.size();i++) {
	    ParseNode pn2=pnv.elementAt(i);
	    boolean status=true;
	    if (isNode(pn2,"not")) {
		status=false;
		pn2=pn2.getChild("name");
	    }
	    String name=pn2.getTerminal();
	    fes.addEffect(new FlagEffect(name,status));
	}
    }

    public FlagExpressionNode parseFlagExpression(ParseNode pn) {
	if (isNode(pn,"or")) {
	    ParseNodeVector pnv=pn.getChildren();
	    ParseNode left=pnv.elementAt(0);
	    ParseNode right=pnv.elementAt(1);
	    return new FlagOpNode(parseFlagExpression(left), parseFlagExpression(right), new Operation(Operation.LOGIC_OR));
	} else if (isNode(pn,"and")) {
	    ParseNodeVector pnv=pn.getChildren();
	    ParseNode left=pnv.elementAt(0);
	    ParseNode right=pnv.elementAt(1);
	    return new FlagOpNode(parseFlagExpression(left), parseFlagExpression(right), new Operation(Operation.LOGIC_AND));
	} else if (isNode(pn, "not")) {
	    ParseNodeVector pnv=pn.getChildren();
	    ParseNode left=pnv.elementAt(0);
	    return new FlagOpNode(parseFlagExpression(left), new Operation(Operation.LOGIC_NOT));	    

	} else if (isNode(pn,"name")) {
	    return new FlagNode(pn.getTerminal());
	} else {
	    throw new Error();
	}
    }

    public Vector parseChecks(ParseNode pn) {
	Vector ccs=new Vector();
	ParseNodeVector pnv=pn.getChildren();
	for(int i=0;i<pnv.size();i++) {
	    ParseNode fn=pnv.elementAt(i);
	    ConstraintCheck cc=parseConstraintCheck(fn);
	    ccs.add(cc);
	}
	return ccs;
    }

    public ConstraintCheck parseConstraintCheck(ParseNode pn) {
	if (isNode(pn,"cons_check")) {
	    String specname=pn.getChild("name").getChild("identifier").getTerminal();
	    Vector[] args=parseConsArgumentList(pn);
	    ConstraintCheck cc=new ConstraintCheck(specname);
	    for(int i=0;i<args[0].size();i++) {
		cc.addVariable((String)args[0].get(i));
		cc.addArgument((ExpressionNode)args[1].get(i));
	    }
	    return cc;
	} else throw new Error();
    }

    public void parseParameterList(TaskDescriptor td, ParseNode pn) {
	
	boolean optional;
	ParseNode paramlist=pn.getChild("task_parameter_list");
	if (paramlist==null)
	    return;
	ParseNodeVector pnv=paramlist.getChildren();
	for(int i=0;i<pnv.size();i++) {
	    ParseNode paramn=pnv.elementAt(i);
	    if(paramn.getChild("optional")!=null){
		optional = true;
		paramn = paramn.getChild("optional").getFirstChild();
		System.out.println("OPTIONAL FOUND!!!!!!!");
	    }
	    else { optional = false;
	    System.out.println("NOT OPTIONAL");
	    }

	    TypeDescriptor type=parseTypeDescriptor(paramn);
	    
	    String paramname=paramn.getChild("single").getTerminal();
	    FlagExpressionNode fen=null;
	    if (paramn.getChild("flag")!=null)
		fen=parseFlagExpression(paramn.getChild("flag").getFirstChild());
	    
	    ParseNode tagnode=paramn.getChild("tag");
	    
	    TagExpressionList tel=null;
	    if (tagnode!=null) {
		tel=parseTagExpressionList(tagnode);
	    }
	    
	    td.addParameter(type,paramname,fen, tel, optional);
	}
    }
    
    public TagExpressionList parseTagExpressionList(ParseNode pn) {
	//BUG FIX: change pn.getChildren() to pn.getChild("tag_expression_list").getChildren()
	//To test, feed in any input program that uses tags
	ParseNodeVector pnv=pn.getChild("tag_expression_list").getChildren();
	TagExpressionList tel=new TagExpressionList();
	for(int i=0;i<pnv.size();i++) {
	    ParseNode tn=pnv.elementAt(i);
	    String type=tn.getChild("type").getTerminal();
	    String name=tn.getChild("single").getTerminal();
	    tel.addTag(type, name);
	}
	return tel;
    }

    public ClassDescriptor parseTypeDecl(ParseNode pn) {
	ClassDescriptor cn=new ClassDescriptor(pn.getChild("name").getTerminal());
	if (!isEmpty(pn.getChild("super").getTerminal())) {
	    /* parse superclass name */
	    ParseNode snn=pn.getChild("super").getChild("type").getChild("class").getChild("name");
	    NameDescriptor nd=parseName(snn);
	    cn.setSuper(nd.toString());
	} else {
	    if (!(cn.getSymbol().equals(TypeUtil.ObjectClass)||
		  cn.getSymbol().equals(TypeUtil.TagClass)))
		cn.setSuper(TypeUtil.ObjectClass);
	}
	cn.setModifiers(parseModifiersList(pn.getChild("modifiers")));
	parseClassBody(cn, pn.getChild("classbody"));
	return cn;
    }

    private void parseClassBody(ClassDescriptor cn, ParseNode pn) {
	ParseNode decls=pn.getChild("class_body_declaration_list");
	if (decls!=null) {
	    ParseNodeVector pnv=decls.getChildren();
	    for(int i=0;i<pnv.size();i++) {
		ParseNode decl=pnv.elementAt(i);
		if (isNode(decl,"member")) {
		    parseClassMember(cn,decl);
		} else if (isNode(decl,"constructor")) {
		    parseConstructorDecl(cn,decl.getChild("constructor_declaration"));
		} else if (isNode(decl,"block")) {
		} else throw new Error();
	    }
	}
    }

    private void parseClassMember(ClassDescriptor cn, ParseNode pn) {
	ParseNode fieldnode=pn.getChild("field");

	if (fieldnode!=null) {
	    parseFieldDecl(cn,fieldnode.getChild("field_declaration"));
	    return;
	}
	ParseNode methodnode=pn.getChild("method");
	if (methodnode!=null) {
	    parseMethodDecl(cn,methodnode.getChild("method_declaration"));
	    return;
	}
	ParseNode flagnode=pn.getChild("flag");
	if (flagnode!=null) {
	    parseFlagDecl(cn, flagnode.getChild("flag_declaration"));
	    return;
	}
	throw new Error();
    }

    private TypeDescriptor parseTypeDescriptor(ParseNode pn) {
	ParseNode tn=pn.getChild("type");

	String type_st=tn.getTerminal();
	if(type_st.equals("byte")) {
	    return state.getTypeDescriptor(TypeDescriptor.BYTE);
	} else if(type_st.equals("short")) {
	    return state.getTypeDescriptor(TypeDescriptor.SHORT);
	} else if(type_st.equals("boolean")) {
	    return state.getTypeDescriptor(TypeDescriptor.BOOLEAN);
	} else if(type_st.equals("int")) {
	    return state.getTypeDescriptor(TypeDescriptor.INT);
	} else if(type_st.equals("long")) {
	    return state.getTypeDescriptor(TypeDescriptor.LONG);
	} else if(type_st.equals("char")) {
	    return state.getTypeDescriptor(TypeDescriptor.CHAR);
	} else if(type_st.equals("float")) {
	    return state.getTypeDescriptor(TypeDescriptor.FLOAT);
	} else if(type_st.equals("double")) {
	    return state.getTypeDescriptor(TypeDescriptor.DOUBLE);
	} else if(type_st.equals("class")) {
	    ParseNode nn=tn.getChild("class");
	    return state.getTypeDescriptor(parseName(nn.getChild("name")));
	} else if(type_st.equals("array")) {
	    ParseNode nn=tn.getChild("array");
	    TypeDescriptor td=parseTypeDescriptor(nn.getChild("basetype"));
	    Integer numdims=(Integer)nn.getChild("dims").getLiteral();
	    for(int i=0;i<numdims.intValue();i++)
		td=td.makeArray(state);
	    return td;
	} else {
	    throw new Error();
	}
    }

    private NameDescriptor parseName(ParseNode nn) {
	ParseNode base=nn.getChild("base");
	ParseNode id=nn.getChild("identifier");
	if (base==null)
	    return new NameDescriptor(id.getTerminal());
	return new NameDescriptor(parseName(base.getChild("name")),id.getTerminal());
	
    }

    private void parseFlagDecl(ClassDescriptor cn,ParseNode pn) {
	String name=pn.getChild("name").getTerminal();
	FlagDescriptor flag=new FlagDescriptor(name);
	if (pn.getChild("external")!=null)
	    flag.makeExternal();
	cn.addFlag(flag);
    }

    private void parseFieldDecl(ClassDescriptor cn,ParseNode pn) {
	ParseNode mn=pn.getChild("modifier");
	Modifiers m=parseModifiersList(mn);

	ParseNode tn=pn.getChild("type");
	TypeDescriptor t=parseTypeDescriptor(tn);
	ParseNode vn=pn.getChild("variables").getChild("variable_declarators_list");
	ParseNodeVector pnv=vn.getChildren();
	boolean isglobal=pn.getChild("global")!=null;

	for(int i=0;i<pnv.size();i++) {
	    ParseNode vardecl=pnv.elementAt(i);
	    ParseNode tmp=vardecl;
	    TypeDescriptor arrayt=t;
	    while (tmp.getChild("single")==null) {
		arrayt=arrayt.makeArray(state);
		tmp=tmp.getChild("array");
	    }
	    String identifier=tmp.getChild("single").getTerminal();
	    ParseNode epn=vardecl.getChild("initializer");

	    ExpressionNode en=null;
	    if (epn!=null)
		en=parseExpression(epn.getFirstChild());
  
	    cn.addField(new FieldDescriptor(m, arrayt, identifier, en, isglobal));
	}
    }

    private ExpressionNode parseExpression(ParseNode pn) {
	if (isNode(pn,"assignment"))
	    return parseAssignmentExpression(pn);
	else if (isNode(pn,"logical_or")||isNode(pn,"logical_and")||
		 isNode(pn,"bitwise_or")||isNode(pn,"bitwise_xor")||
		 isNode(pn,"bitwise_and")||isNode(pn,"equal")||
		 isNode(pn,"not_equal")||isNode(pn,"comp_lt")||
		 isNode(pn,"comp_lte")||isNode(pn,"comp_gt")||
		 isNode(pn,"comp_gte")||isNode(pn,"leftshift")||
		 isNode(pn,"rightshift")||isNode(pn,"sub")||
		 isNode(pn,"urightshift")||isNode(pn,"sub")||
		 isNode(pn,"add")||isNode(pn,"mult")||
		 isNode(pn,"div")||isNode(pn,"mod")) {
	    ParseNodeVector pnv=pn.getChildren();
	    ParseNode left=pnv.elementAt(0);
	    ParseNode right=pnv.elementAt(1);
	    Operation op=new Operation(pn.getLabel());
   	    return new OpNode(parseExpression(left),parseExpression(right),op);
	} else if (isNode(pn,"unaryplus")||
		   isNode(pn,"unaryminus")||
		   isNode(pn,"not")||
		   isNode(pn,"comp")) {
	    ParseNode left=pn.getFirstChild();
	    Operation op=new Operation(pn.getLabel());
   	    return new OpNode(parseExpression(left),op);
	} else if (isNode(pn,"postinc")||
		   isNode(pn,"postdec")) {
	    ParseNode left=pn.getFirstChild();
	    AssignOperation op=new AssignOperation(pn.getLabel());
   	    return new AssignmentNode(parseExpression(left),null,op);

	} else if (isNode(pn,"preinc")||
		   isNode(pn,"predec")) {
	    ParseNode left=pn.getFirstChild();
	    AssignOperation op=isNode(pn,"preinc")?new AssignOperation(AssignOperation.PLUSEQ):new AssignOperation(AssignOperation.MINUSEQ);
   	    return new AssignmentNode(parseExpression(left),
				      new LiteralNode("integer",new Integer(1)),op);
	} else if (isNode(pn,"literal")) {
	    String literaltype=pn.getTerminal();
	    ParseNode literalnode=pn.getChild(literaltype);
	    Object literal_obj=literalnode.getLiteral();
	    return new LiteralNode(literaltype, literal_obj);
	} else if (isNode(pn,"createobject")) {
	    TypeDescriptor td=parseTypeDescriptor(pn);
	    Vector args=parseArgumentList(pn);
	    boolean isglobal=pn.getChild("global")!=null;
	    CreateObjectNode con=new CreateObjectNode(td, isglobal);
	    for(int i=0;i<args.size();i++) {
		con.addArgument((ExpressionNode)args.get(i));
	    }
	    /* Could have flag set or tag added here */
	    if (pn.getChild("flag_list")!=null||pn.getChild("tag_list")!=null) {
		FlagEffects fe=new FlagEffects(null);
		if (pn.getChild("flag_list")!=null)
		    parseFlagEffect(fe, pn.getChild("flag_list"));

		if (pn.getChild("tag_list")!=null)
		    parseTagEffect(fe, pn.getChild("tag_list"));
		con.addFlagEffects(fe);
	    }
	    
	    return con;
	} else if (isNode(pn,"createarray")) {
	    //System.out.println(pn.PPrint(3,true));
	    boolean isglobal=pn.getChild("global")!=null;
	    TypeDescriptor td=parseTypeDescriptor(pn);
	    Vector args=parseDimExprs(pn);
	    int num=0;
	    if (pn.getChild("dims_opt").getLiteral()!=null)
		num=((Integer)pn.getChild("dims_opt").getLiteral()).intValue();
	    for(int i=0;i<(args.size()+num);i++)
		td=td.makeArray(state);
	    CreateObjectNode con=new CreateObjectNode(td, isglobal);
	    for(int i=0;i<args.size();i++) {
		con.addArgument((ExpressionNode)args.get(i));
	    }
	    return con;
	} else if (isNode(pn,"name")) {
	    NameDescriptor nd=parseName(pn);
	    return new NameNode(nd);
	} else if (isNode(pn,"this")) {
	    NameDescriptor nd=new NameDescriptor("this");
	    return new NameNode(nd);
	} else if (isNode(pn,"isavailable")) {
	    NameDescriptor nd=new NameDescriptor(pn.getTerminal());
   	    return new OpNode(new NameNode(nd),null,new Operation(Operation.ISAVAILABLE));
	} else if (isNode(pn,"methodinvoke1")) {
	    NameDescriptor nd=parseName(pn.getChild("name"));
	    Vector args=parseArgumentList(pn);
	    MethodInvokeNode min=new MethodInvokeNode(nd);
	    for(int i=0;i<args.size();i++) {
		min.addArgument((ExpressionNode)args.get(i));
	    }
	    return min;
	} else if (isNode(pn,"methodinvoke2")) {
	    String methodid=pn.getChild("id").getTerminal();
	    ExpressionNode exp=parseExpression(pn.getChild("base").getFirstChild());
	    Vector args=parseArgumentList(pn);
	    MethodInvokeNode min=new MethodInvokeNode(methodid,exp);
	    for(int i=0;i<args.size();i++) {
		min.addArgument((ExpressionNode)args.get(i));
	    }
	    return min;
	} else if (isNode(pn,"fieldaccess")) { 
	    ExpressionNode en=parseExpression(pn.getChild("base").getFirstChild());	    String fieldname=pn.getChild("field").getTerminal();
	    return new FieldAccessNode(en,fieldname);
	} else if (isNode(pn,"arrayaccess")) { 
	    ExpressionNode en=parseExpression(pn.getChild("base").getFirstChild());
	    ExpressionNode index=parseExpression(pn.getChild("index").getFirstChild());
	    return new ArrayAccessNode(en,index);
	} else if (isNode(pn,"cast1")) { 
	    return new CastNode(parseTypeDescriptor(pn.getChild("type")),parseExpression(pn.getChild("exp").getFirstChild()));
	} else if (isNode(pn,"cast2")) { 
	    return new CastNode(parseExpression(pn.getChild("type").getFirstChild()),parseExpression(pn.getChild("exp").getFirstChild()));
	} else {
	    System.out.println("---------------------");
	    System.out.println(pn.PPrint(3,true));
	    throw new Error();
	}
    }

    private Vector parseDimExprs(ParseNode pn) {
	Vector arglist=new Vector();
	ParseNode an=pn.getChild("dim_exprs");
	if (an==null)   /* No argument list */
	    return arglist;
	ParseNodeVector anv=an.getChildren();
	for(int i=0;i<anv.size();i++) {
	    arglist.add(parseExpression(anv.elementAt(i)));
	}
	return arglist;
    }

    private Vector parseArgumentList(ParseNode pn) {
	Vector arglist=new Vector();
	ParseNode an=pn.getChild("argument_list");
	if (an==null)   /* No argument list */
	    return arglist;
	ParseNodeVector anv=an.getChildren();
	for(int i=0;i<anv.size();i++) {
	    arglist.add(parseExpression(anv.elementAt(i)));
	}
	return arglist;
    }

    private Vector[] parseConsArgumentList(ParseNode pn) {
	Vector arglist=new Vector();
	Vector varlist=new Vector();
	ParseNode an=pn.getChild("cons_argument_list");
	if (an==null)   /* No argument list */
	    return new Vector[] {varlist, arglist};
	ParseNodeVector anv=an.getChildren();
	for(int i=0;i<anv.size();i++) {
	    ParseNode cpn=anv.elementAt(i);
	    ParseNode var=cpn.getChild("var");
	    ParseNode exp=cpn.getChild("exp").getFirstChild();
	    varlist.add(var.getTerminal());
	    arglist.add(parseExpression(exp));
	}
	return new Vector[] {varlist, arglist};
    }

    private ExpressionNode parseAssignmentExpression(ParseNode pn) {
	AssignOperation ao=new AssignOperation(pn.getChild("op").getTerminal());
	ParseNodeVector pnv=pn.getChild("args").getChildren();
	
	AssignmentNode an=new AssignmentNode(parseExpression(pnv.elementAt(0)),parseExpression(pnv.elementAt(1)),ao);
	return an;
    }


    private void parseMethodDecl(ClassDescriptor cn, ParseNode pn) {
	ParseNode headern=pn.getChild("method_header");
	ParseNode bodyn=pn.getChild("body");
	MethodDescriptor md=parseMethodHeader(headern);
	BlockNode bn=parseBlock(bodyn);
	cn.addMethod(md);
	state.addTreeCode(md,bn);
    }

    private void parseConstructorDecl(ClassDescriptor cn, ParseNode pn) {
	ParseNode mn=pn.getChild("modifiers");
	Modifiers m=parseModifiersList(mn);
	ParseNode cdecl=pn.getChild("constructor_declarator");
	boolean isglobal=cdecl.getChild("global")!=null;
	String name=cdecl.getChild("name").getChild("identifier").getTerminal();
	MethodDescriptor md=new MethodDescriptor(m, name, isglobal);
	ParseNode paramnode=cdecl.getChild("parameters");
	parseParameterList(md,paramnode);
	ParseNode bodyn0=pn.getChild("body");
	ParseNode bodyn=bodyn0.getChild("constructor_body");
	cn.addMethod(md);
	BlockNode bn=null;
	if (bodyn!=null&&bodyn.getChild("block_statement_list")!=null)
	    bn=parseBlock(bodyn);
	else
	    bn=new BlockNode();
	if (bodyn!=null&&bodyn.getChild("superinvoke")!=null) {
	    ParseNode sin=bodyn.getChild("superinvoke");
	    NameDescriptor nd=new NameDescriptor("super");
	    Vector args=parseArgumentList(sin);
	    MethodInvokeNode min=new MethodInvokeNode(nd);
	    for(int i=0;i<args.size();i++) {
		min.addArgument((ExpressionNode)args.get(i));
	    }
	    BlockExpressionNode ben=new BlockExpressionNode(min);
	    bn.addFirstBlockStatement(ben);
	}
	state.addTreeCode(md,bn);
    }

    public BlockNode parseBlock(ParseNode pn) {
	if (pn==null||isEmpty(pn.getTerminal()))
	    return new BlockNode();
	ParseNode bsn=pn.getChild("block_statement_list");
	return parseBlockHelper(bsn);
    }
    
    private BlockNode parseBlockHelper(ParseNode pn) {
	ParseNodeVector pnv=pn.getChildren();
	BlockNode bn=new BlockNode();
	for(int i=0;i<pnv.size();i++) {
	    Vector bsv=parseBlockStatement(pnv.elementAt(i));
	    for(int j=0;j<bsv.size();j++) {
		bn.addBlockStatement((BlockStatementNode)bsv.get(j));
	    }
	}
	return bn;
    }

    public BlockNode parseSingleBlock(ParseNode pn) {
	BlockNode bn=new BlockNode();
	Vector bsv=parseBlockStatement(pn);
	for(int j=0;j<bsv.size();j++) {
	    bn.addBlockStatement((BlockStatementNode)bsv.get(j));
	}
	bn.setStyle(BlockNode.NOBRACES);
	return bn;
    }

    public Vector parseBlockStatement(ParseNode pn) {
	Vector blockstatements=new Vector();
	if (isNode(pn,"tag_declaration")) {
	    String name=pn.getChild("single").getTerminal();
	    String type=pn.getChild("type").getTerminal();
	    
	    blockstatements.add(new TagDeclarationNode(name, type));
	} else if (isNode(pn,"local_variable_declaration")) {
	    TypeDescriptor t=parseTypeDescriptor(pn);
	    ParseNode vn=pn.getChild("variable_declarators_list");
	    ParseNodeVector pnv=vn.getChildren();
	    for(int i=0;i<pnv.size();i++) {
		ParseNode vardecl=pnv.elementAt(i);

	    
		ParseNode tmp=vardecl;
		TypeDescriptor arrayt=t;
		while (tmp.getChild("single")==null) {
		    arrayt=arrayt.makeArray(state);
		    tmp=tmp.getChild("array");
		}
		String identifier=tmp.getChild("single").getTerminal();
		
		ParseNode epn=vardecl.getChild("initializer");
	    

		ExpressionNode en=null;
		if (epn!=null)
		    en=parseExpression(epn.getFirstChild());
		
		blockstatements.add(new DeclarationNode(new VarDescriptor(arrayt, identifier),en));
	    }
	} else if (isNode(pn,"nop")) {
	    /* Do Nothing */
	} else if (isNode(pn,"expression")) {
	    blockstatements.add(new BlockExpressionNode(parseExpression(pn.getFirstChild())));
	} else if (isNode(pn,"ifstatement")) {
	    blockstatements.add(new IfStatementNode(parseExpression(pn.getChild("condition").getFirstChild()),
				       parseSingleBlock(pn.getChild("statement").getFirstChild()),
				       pn.getChild("else_statement")!=null?parseSingleBlock(pn.getChild("else_statement").getFirstChild()):null));
	} else if (isNode(pn,"taskexit")) {
	    Vector vfe=null;
	    if (pn.getChild("flag_effects_list")!=null)
		vfe=parseFlags(pn.getChild("flag_effects_list"));
	    Vector ccs=null;
	    if (pn.getChild("cons_checks")!=null)
		ccs=parseChecks(pn.getChild("cons_checks"));
	    
	    blockstatements.add(new TaskExitNode(vfe, ccs));
	} else if (isNode(pn,"atomic")) {
	    BlockNode bn=parseBlockHelper(pn);
	    blockstatements.add(new AtomicNode(bn));
	} else if (isNode(pn,"return")) {
	    if (isEmpty(pn.getTerminal()))
		blockstatements.add(new ReturnNode());
	    else {
		ExpressionNode en=parseExpression(pn.getFirstChild());
		blockstatements.add(new ReturnNode(en));
	    }
	} else if (isNode(pn,"block_statement_list")) {
	    BlockNode bn=parseBlockHelper(pn);
	    blockstatements.add(new SubBlockNode(bn));
	} else if (isNode(pn,"empty")) {
	    /* nop */
	} else if (isNode(pn,"statement_expression_list")) {
	    ParseNodeVector pnv=pn.getChildren();
	    BlockNode bn=new BlockNode();
	    for(int i=0;i<pnv.size();i++) {
		ExpressionNode en=parseExpression(pnv.elementAt(i));
		blockstatements.add(new BlockExpressionNode(en));
	    }
	    bn.setStyle(BlockNode.EXPRLIST);
	} else if (isNode(pn,"forstatement")) {
	    BlockNode init=parseSingleBlock(pn.getChild("initializer").getFirstChild());
	    BlockNode update=parseSingleBlock(pn.getChild("update").getFirstChild());
	    ExpressionNode condition=parseExpression(pn.getChild("condition").getFirstChild());
	    BlockNode body=parseSingleBlock(pn.getChild("statement").getFirstChild());
	    blockstatements.add(new LoopNode(init,condition,update,body));
	} else if (isNode(pn,"whilestatement")) {
	    ExpressionNode condition=parseExpression(pn.getChild("condition").getFirstChild());
	    BlockNode body=parseSingleBlock(pn.getChild("statement").getFirstChild());
	    blockstatements.add(new LoopNode(condition,body,LoopNode.WHILELOOP));
	} else if (isNode(pn,"dowhilestatement")) {
	    ExpressionNode condition=parseExpression(pn.getChild("condition").getFirstChild());
	    BlockNode body=parseSingleBlock(pn.getChild("statement").getFirstChild());
	    blockstatements.add(new LoopNode(condition,body,LoopNode.DOWHILELOOP));
	} else {
	    System.out.println("---------------");
	    System.out.println(pn.PPrint(3,true));
	    throw new Error();
	}
	return blockstatements;
    }

    public MethodDescriptor parseMethodHeader(ParseNode pn) {
	ParseNode mn=pn.getChild("modifiers");
	Modifiers m=parseModifiersList(mn);
	
	ParseNode tn=pn.getChild("returntype");
	TypeDescriptor returntype;
	if (tn!=null) 
	    returntype=parseTypeDescriptor(tn);
	else
	    returntype=new TypeDescriptor(TypeDescriptor.VOID);

	ParseNode pmd=pn.getChild("method_declarator");
	String name=pmd.getChild("name").getTerminal();
	MethodDescriptor md=new MethodDescriptor(m, returntype, name);
       
	ParseNode paramnode=pmd.getChild("parameters");
	parseParameterList(md,paramnode);
	return md;
    }

    public void parseParameterList(MethodDescriptor md, ParseNode pn) {
	ParseNode paramlist=pn.getChild("formal_parameter_list");
	if (paramlist==null)
	    return;
	 ParseNodeVector pnv=paramlist.getChildren();
	 for(int i=0;i<pnv.size();i++) {
	     ParseNode paramn=pnv.elementAt(i);

	     if (isNode(paramn, "tag_parameter")) {
		 String paramname=paramn.getChild("single").getTerminal();
		 TypeDescriptor type=new TypeDescriptor(TypeDescriptor.TAG);
		 md.addTagParameter(type, paramname);
	     } else {
		 TypeDescriptor type=parseTypeDescriptor(paramn);
		 
		 ParseNode tmp=paramn;
		 while (tmp.getChild("single")==null) {
		     type=type.makeArray(state);
		     tmp=tmp.getChild("array");
		 }
		 String paramname=tmp.getChild("single").getTerminal();
		 
		 md.addParameter(type, paramname);
	     }
	 }
    }

    public Modifiers parseModifiersList(ParseNode pn) {
	Modifiers m=new Modifiers();
	ParseNode modlist=pn.getChild("modifier_list");
	if (modlist!=null) {
	    ParseNodeVector pnv=modlist.getChildren();
	    for(int i=0;i<pnv.size();i++) {
		ParseNode modn=pnv.elementAt(i);
		if (isNode(modn,"public"))
		    m.addModifier(Modifiers.PUBLIC);
		else if (isNode(modn,"protected"))
		    m.addModifier(Modifiers.PROTECTED);
		else if (isNode(modn,"private"))
		    m.addModifier(Modifiers.PRIVATE);
		else if (isNode(modn,"static"))
		    m.addModifier(Modifiers.STATIC);
		else if (isNode(modn,"final"))
		    m.addModifier(Modifiers.FINAL);
		else if (isNode(modn,"native"))
		    m.addModifier(Modifiers.NATIVE);
		else if (isNode(modn,"synchronized"))
		    m.addModifier(Modifiers.SYNCHRONIZED);
		else if (isNode(modn,"atomic"))
		    m.addModifier(Modifiers.ATOMIC);
		else throw new Error("Unrecognized Modifier");
	    }
	}
	return m;
    }

    private boolean isNode(ParseNode pn, String label) {
	if (pn.getLabel().equals(label))
	    return true;
	else return false;
    }

    private static boolean isEmpty(ParseNode pn) {
	if (pn.getLabel().equals("empty"))
	    return true;
	else
	    return false;
    }

    private static boolean isEmpty(String s) {
	if (s.equals("empty"))
	    return true;
	else
	    return false;
    }

    /** Throw an exception if something is unexpected */
    private void check(ParseNode pn, String label) {
        if (pn == null) {
            throw new Error(pn+ "IE: Expected '" + label + "', got null");
        }
        if (! pn.getLabel().equals(label)) {
            throw new Error(pn+ "IE: Expected '" + label + "', got '"+pn.getLabel()+"'");
        }
    }
}