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	/*
	* Copyright (c) 1994, 2004, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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 General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package sun.tools.tree;

	import sun.tools.java.*;
	import sun.tools.asm.Assembler;
	import sun.tools.asm.Label;
	import sun.tools.asm.TryData;
	import sun.tools.asm.CatchData;
	import java.io.PrintStream;
	import java.util.Hashtable;
	import java.util.Enumeration;

	/**
	* WARNING: The contents of this source file are not part of any
	* supported API. Code that depends on them does so at its own risk:
	* they are subject to change or removal without notice.
	*/
	public
	class FinallyStatement extends Statement {
	Statement body;
	Statement finalbody;
	boolean finallyCanFinish; // does finalBody never return?
	boolean needReturnSlot; // set by inner return statement
	Statement init; // try object expression or declaration from parser
	LocalMember tryTemp; // temp holding the try object, if any

	/**
	* Constructor
	*/
	public FinallyStatement(long where, Statement body, Statement finalbody) {
	super(FINALLY, where);
	this.body = body;
	this.finalbody = finalbody;
	}

	// /**
	// * Constructor for try (init) {body}
	// */
	// public FinallyStatement(long where, Statement init, Statement body, int junk) {
	// this(where, body, null);
	// this.init = init;
	// }

	/**
	* Check statement
	*/
	Vset check(Environment env, Context ctx, Vset vset, Hashtable exp) {
	vset = reach(env, vset);
	Hashtable newexp = new Hashtable();

	// Handle the proposed 'try (init) { stmts } finally { stmts }' syntax.
	// This feature has not been adopted, and support is presently disabled.
	/-----------------------------------------------------------
	if (init != null) {
	ClassDefinition sourceClass = ctx.field.getClassDefinition();
	Expression tryExpr = null;
	DeclarationStatement tryDecl = null;
	long where = init.getWhere();
	// find out whether init is a simple expression or a declaration
	if (init.getOp() == EXPRESSION) {
	tryExpr = ((ExpressionStatement)init).expr;
	init = null; // restore it below
	vset = tryExpr.checkValue(env, ctx, vset, exp);
	} else if (init.getOp() == DECLARATION) {
	tryDecl = (DeclarationStatement) init;
	init = null; // restore it below
	vset = tryDecl.checkBlockStatement(env, ctx, vset, exp);
	if (tryDecl.args.length != 1) {
	env.error(where, "invalid.decl");
	} else {
	LocalMember field =
	((VarDeclarationStatement) tryDecl.args[0]).field;
	tryExpr = new IdentifierExpression(where, field);
	tryExpr.type = field.getType();
	}
	} else {
	env.error(where, "invalid.expr");
	vset = init.check(env, ctx, vset, exp);
	}
	Type type = (tryExpr == null) ? Type.tError : tryExpr.getType();

	MemberDefinition tryEnter = null;
	MemberDefinition tryExit = null;
	if (!type.isType(TC_CLASS)) {
	if (!type.isType(TC_ERROR)) {
	env.error(where, "invalid.method.invoke", type);
	}
	} else {
	Identifier idTryEnter = Identifier.lookup("tryEnter");
	Identifier idTryExit = Identifier.lookup("tryExit");
	Type tTryMethod = Type.tMethod(Type.tVoid);
	try {
	ClassDefinition tryClass = env.getClassDefinition(type);
	tryEnter = tryClass.matchMethod(env, sourceClass, idTryEnter);
	tryExit = tryClass.matchMethod(env, sourceClass, idTryExit);
	if (tryEnter != null && !tryEnter.getType().equals(tTryMethod)) {
	tryEnter = null;
	}
	if (tryExit != null && !tryExit.getType().equals(tTryMethod)) {
	tryExit = null;
	}
	} catch (ClassNotFound ee) {
	env.error(where, "class.not.found", ee.name, ctx.field);
	} catch (AmbiguousMember ee) {
	Identifier id = ee.field1.getName();
	env.error(where, "ambig.field", id, ee.field1, ee.field2);
	}
	}
	if (tryEnter == null \|\| tryExit == null) {
	// Make a better (more didactic) error here!
	env.error(where, "invalid.method.invoke", type);
	} else {
	tryTemp = new LocalMember(where, sourceClass, 0,
	type, Identifier.lookup("<try_object>"));
	ctx = new Context(ctx, this);
	ctx.declare(env, tryTemp);

	Expression e;
	e = new IdentifierExpression(where, tryTemp);
	e = new AssignExpression(where, e, tryExpr);
	e = new MethodExpression(where, e, tryEnter, new Expression[0]);
	e.type = Type.tVoid;
	Statement enterCall = new ExpressionStatement(where, e);
	// store it on the init, for code generation
	if (tryDecl != null) {
	Statement args2[] = { tryDecl.args[0], enterCall };
	tryDecl.args = args2;
	init = tryDecl;
	} else {
	init = enterCall;
	}
	e = new IdentifierExpression(where, tryTemp);
	e = new MethodExpression(where, e, tryExit, new Expression[0]);
	e.type = Type.tVoid;
	Statement exitCall = new ExpressionStatement(where, e);
	finalbody = exitCall;
	}
	}
	-----------------------------------------------------------/

	// Check the try part. We reach the end of the try part either by
	// finishing normally, or doing a break to the label of the try/finally.
	// NOTE: I don't think newctx1.vsBreak is ever used -- see TryStatement.
	CheckContext newctx1 = new CheckContext(ctx, this);
	Vset vset1 = body.check(env, newctx1, vset.copy(), newexp)
	.join(newctx1.vsBreak);
	// Check the finally part.
	CheckContext newctx2 = new CheckContext(ctx, this);
	// Should never access this field. The null indicates the finally part.
	newctx2.vsContinue = null;
	Vset vset2 = finalbody.check(env, newctx2, vset, exp);
	finallyCanFinish = !vset2.isDeadEnd();
	vset2 = vset2.join(newctx2.vsBreak);
	// If !finallyCanFinish, then the only possible exceptions that can
	// occur at this point are the ones preceding the try/finally, or
	// the ones generated by the finally. Anything in the try is
	// irrelevant. Otherwise, we have to merge in all the exceptions
	// generated by the body into exp.
	if (finallyCanFinish) {
	// Add newexp's back into exp; cf. ThrowStatement.check().
	for (Enumeration e = newexp.keys() ; e.hasMoreElements() ; ) {
	Object def = e.nextElement();
	exp.put(def, newexp.get(def));
	}
	}
	return ctx.removeAdditionalVars(vset1.addDAandJoinDU(vset2));
	}

	/**
	* Inline
	*/
	public Statement inline(Environment env, Context ctx) {
	if (tryTemp != null) {
	ctx = new Context(ctx, this);
	ctx.declare(env, tryTemp);
	}
	if (init != null) {
	init = init.inline(env, ctx);
	}
	if (body != null) {
	body = body.inline(env, ctx);
	}
	if (finalbody != null) {
	finalbody = finalbody.inline(env, ctx);
	}
	if (body == null) {
	return eliminate(env, finalbody);
	}
	if (finalbody == null) {
	return eliminate(env, body);
	}
	return this;
	}

	/**
	* Create a copy of the statement for method inlining
	*/
	public Statement copyInline(Context ctx, boolean valNeeded) {
	FinallyStatement s = (FinallyStatement)clone();
	if (tryTemp != null) {
	s.tryTemp = tryTemp.copyInline(ctx);
	}
	if (init != null) {
	s.init = init.copyInline(ctx, valNeeded);
	}
	if (body != null) {
	s.body = body.copyInline(ctx, valNeeded);
	}
	if (finalbody != null) {
	s.finalbody = finalbody.copyInline(ctx, valNeeded);
	}
	return s;
	}

	/**
	* Compute cost of inlining this statement
	*/
	public int costInline(int thresh, Environment env, Context ctx){
	int cost = 4;
	if (init != null) {
	cost += init.costInline(thresh, env,ctx);
	if (cost >= thresh) return cost;
	}
	if (body != null) {
	cost += body.costInline(thresh, env,ctx);
	if (cost >= thresh) return cost;
	}
	if (finalbody != null) {
	cost += finalbody.costInline(thresh, env,ctx);
	}
	return cost;
	}

	/**
	* Code
	*/
	public void code(Environment env, Context ctx, Assembler asm) {
	ctx = new Context(ctx);
	Integer num1 = null, num2 = null;
	Label endLabel = new Label();

	if (tryTemp != null) {
	ctx.declare(env, tryTemp);
	}
	if (init != null) {
	CodeContext exprctx = new CodeContext(ctx, this);
	init.code(env, exprctx, asm);
	}

	if (finallyCanFinish) {
	LocalMember f1, f2;
	ClassDefinition thisClass = ctx.field.getClassDefinition();

	if (needReturnSlot) {
	Type returnType = ctx.field.getType().getReturnType();
	LocalMember localfield = new LocalMember(0, thisClass, 0,
	returnType,
	idFinallyReturnValue);
	ctx.declare(env, localfield);
	env.debugOutput("Assigning return slot to " + localfield.number);
	}

	// allocate space for the exception and return address
	f1 = new LocalMember(where, thisClass, 0, Type.tObject, null);
	f2 = new LocalMember(where, thisClass, 0, Type.tInt, null);
	num1 = new Integer(ctx.declare(env, f1));
	num2 = new Integer(ctx.declare(env, f2));
	}

	TryData td = new TryData();
	td.add(null);

	// Main body
	CodeContext bodyctx = new CodeContext(ctx, this);
	asm.add(where, opc_try, td); // start of protected code
	body.code(env, bodyctx, asm);
	asm.add(bodyctx.breakLabel);
	asm.add(td.getEndLabel()); // end of protected code

	// Cleanup afer body
	if (finallyCanFinish) {
	asm.add(where, opc_jsr, bodyctx.contLabel);
	asm.add(where, opc_goto, endLabel);
	} else {
	// just goto the cleanup code. It will never return.
	asm.add(where, opc_goto, bodyctx.contLabel);
	}

	// Catch code
	CatchData cd = td.getCatch(0);
	asm.add(cd.getLabel());
	if (finallyCanFinish) {
	asm.add(where, opc_astore, num1); // store exception
	asm.add(where, opc_jsr, bodyctx.contLabel);
	asm.add(where, opc_aload, num1); // rethrow exception
	asm.add(where, opc_athrow);
	} else {
	// pop exception off stack. Fall through to finally code
	asm.add(where, opc_pop);
	}

	// The finally part, which is marked by the contLabel. Update
	// breakLabel: since break's in the finally are different
	// contLabel: to null to indicate no longer in the protected code.
	asm.add(bodyctx.contLabel);
	bodyctx.contLabel = null;
	bodyctx.breakLabel = endLabel;
	if (finallyCanFinish) {
	asm.add(where, opc_astore, num2); // save the return address
	finalbody.code(env, bodyctx, asm); // execute the cleanup code
	asm.add(where, opc_ret, num2); // return
	} else {
	finalbody.code(env, bodyctx, asm); // execute the cleanup code
	}
	asm.add(endLabel); // breaks come here
	}

	/**
	* Print
	*/
	public void print(PrintStream out, int indent) {
	super.print(out, indent);
	out.print("try ");
	if (body != null) {
	body.print(out, indent);
	} else {
	out.print("<empty>");
	}
	out.print(" finally ");
	if (finalbody != null) {
	finalbody.print(out, indent);
	} else {
	out.print("<empty>");
	}
	}
	}

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