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	/*
	* Copyright (c) 1994, 2003, 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.Enumeration;
	import java.util.Hashtable;

	/**
	* 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 TryStatement extends Statement {
	Statement body;
	Statement args[];
	long arrayCloneWhere; // private note posted from MethodExpression

	/**
	* Constructor
	*/
	public TryStatement(long where, Statement body, Statement args[]) {
	super(TRY, where);
	this.body = body;
	this.args = args;
	}

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

	// Check 'try' block. A variable is DA (DU) before the try
	// block if it is DA (DU) before the try statement.
	Vset vs = body.check(env, newctx, vset.copy(), newexp);

	// A variable is DA before a catch block if it is DA before the
	// try statement. A variable is DU before a catch block if it
	// is DU after the try block and before any 'break', 'continue',
	// 'throw', or 'return' contained therein. That is, the variable
	// is DU upon entry to the try-statement and is not assigned to
	// anywhere within the try block.
	Vset cvs = Vset.firstDAandSecondDU(vset, vs.copy().join(newctx.vsTryExit));

	for (int i = 0 ; i < args.length ; i++) {
	// A variable is DA (DU) after a try statement if
	// it is DA (DU) after every catch block.
	vs = vs.join(args[i].check(env, newctx, cvs.copy(), exp));
	}

	// Check that catch statements are actually reached
	for (int i = 1 ; i < args.length ; i++) {
	CatchStatement cs = (CatchStatement)args[i];
	if (cs.field == null) {
	continue;
	}
	Type type = cs.field.getType();
	ClassDefinition def = env.getClassDefinition(type);

	for (int j = 0 ; j < i ; j++) {
	CatchStatement cs2 = (CatchStatement)args[j];
	if (cs2.field == null) {
	continue;
	}
	Type t = cs2.field.getType();
	ClassDeclaration c = env.getClassDeclaration(t);
	if (def.subClassOf(env, c)) {
	env.error(args[i].where, "catch.not.reached");
	break;
	}
	}
	}

	ClassDeclaration ignore1 = env.getClassDeclaration(idJavaLangError);
	ClassDeclaration ignore2 = env.getClassDeclaration(idJavaLangRuntimeException);

	// Make sure the exception is actually throw in that part of the code
	for (int i = 0 ; i < args.length ; i++) {
	CatchStatement cs = (CatchStatement)args[i];
	if (cs.field == null) {
	continue;
	}
	Type type = cs.field.getType();
	if (!type.isType(TC_CLASS)) {
	// CatchStatement.checkValue() will have already printed
	// an error message
	continue;
	}

	ClassDefinition def = env.getClassDefinition(type);

	// Anyone can throw these!
	if (def.subClassOf(env, ignore1) \|\| def.superClassOf(env, ignore1) \|\|
	def.subClassOf(env, ignore2) \|\| def.superClassOf(env, ignore2)) {
	continue;
	}

	// Make sure the exception is actually throw in that part of the code
	boolean ok = false;
	for (Enumeration e = newexp.keys() ; e.hasMoreElements() ; ) {
	ClassDeclaration c = (ClassDeclaration)e.nextElement();
	if (def.superClassOf(env, c) \|\| def.subClassOf(env, c)) {
	ok = true;
	break;
	}
	}
	if (!ok && arrayCloneWhere != 0
	&& def.getName().toString().equals("java.lang.CloneNotSupportedException")) {
	env.error(arrayCloneWhere, "warn.array.clone.supported", def.getName());
	}

	if (!ok) {
	env.error(cs.where, "catch.not.thrown", def.getName());
	}
	}

	// Only carry over exceptions that are not caught
	for (Enumeration e = newexp.keys() ; e.hasMoreElements() ; ) {
	ClassDeclaration c = (ClassDeclaration)e.nextElement();
	ClassDefinition def = c.getClassDefinition(env);
	boolean add = true;
	for (int i = 0 ; i < args.length ; i++) {
	CatchStatement cs = (CatchStatement)args[i];
	if (cs.field == null) {
	continue;
	}
	Type type = cs.field.getType();
	if (type.isType(TC_ERROR))
	continue;
	if (def.subClassOf(env, env.getClassDeclaration(type))) {
	add = false;
	break;
	}
	}
	if (add) {
	exp.put(c, newexp.get(c));
	}
	}
	// A variable is DA (DU) after a try statement if it is DA (DU)
	// after the try block and after every catch block. These variables
	// are represented by 'vs'. If the try statement is labelled, we
	// may also exit from it (including from within a catch block) via
	// a break statement.
	// If there is a finally block, the Vset returned here is further
	// adjusted. Note that this 'TryStatement' node will be a child of
	// a 'FinallyStatement' node in that case.
	return ctx.removeAdditionalVars(vs.join(newctx.vsBreak));
	} catch (ClassNotFound e) {
	env.error(where, "class.not.found", e.name, opNames[op]);
	return vset;
	}
	}

	/**
	* Inline
	*/
	public Statement inline(Environment env, Context ctx) {
	if (body != null) {
	body = body.inline(env, new Context(ctx, this));
	}
	if (body == null) {
	return null;
	}
	for (int i = 0 ; i < args.length ; i++) {
	if (args[i] != null) {
	args[i] = args[i].inline(env, new Context(ctx, this));
	}
	}
	return (args.length == 0) ? eliminate(env, body) : this;
	}

	/**
	* Create a copy of the statement for method inlining
	*/
	public Statement copyInline(Context ctx, boolean valNeeded) {
	TryStatement s = (TryStatement)clone();
	if (body != null) {
	s.body = body.copyInline(ctx, valNeeded);
	}
	s.args = new Statement[args.length];
	for (int i = 0 ; i < args.length ; i++) {
	if (args[i] != null) {
	s.args[i] = args[i].copyInline(ctx, valNeeded);
	}
	}
	return s;
	}

	/**
	* Compute cost of inlining this statement
	*/
	public int costInline(int thresh, Environment env, Context ctx){

	// Don't inline methods containing try statements.
	// If the try statement is being inlined in order to
	// inline a method that returns a value which is
	// a subexpression of an expression involving the
	// operand stack, then the early operands may get lost.
	// This shows up as a verifier error. For example,
	// in the following:
	//
	// public static int test() {
	// try { return 2; } catch (Exception e) { return 0; }
	// }
	//
	// System.out.println(test());
	//
	// an inlined call to test() might look like this:
	//
	// 0 getstatic <Field java.io.PrintStream out>
	// 3 iconst_2
	// 4 goto 9
	// 7 pop
	// 8 iconst_0
	// 9 invokevirtual <Method void println(int)>
	// 12 return
	// Exception table:
	// from to target type
	// 3 7 7 <Class java.lang.Exception>
	//
	// This fails to verify because the operand stored
	// for System.out gets axed at an exception, leading to
	// an inconsistent stack depth at pc=7.
	//
	// Note that although all code must be able to be inlined
	// to implement initializers, this problem doesn't come up,
	// as try statements themselves can never be expressions.
	// It suffices here to make sure they are never inlined as part
	// of optimization.

	return thresh;
	}

	/**
	* Code
	*/
	public void code(Environment env, Context ctx, Assembler asm) {
	CodeContext newctx = new CodeContext(ctx, this);

	TryData td = new TryData();
	for (int i = 0 ; i < args.length ; i++) {
	Type t = ((CatchStatement)args[i]).field.getType();
	if (t.isType(TC_CLASS)) {
	td.add(env.getClassDeclaration(t));
	} else {
	td.add(t);
	}
	}
	asm.add(where, opc_try, td);
	if (body != null) {
	body.code(env, newctx, asm);
	}

	asm.add(td.getEndLabel());
	asm.add(where, opc_goto, newctx.breakLabel);

	for (int i = 0 ; i < args.length ; i++) {
	CatchData cd = td.getCatch(i);
	asm.add(cd.getLabel());
	args[i].code(env, newctx, asm);
	asm.add(where, opc_goto, newctx.breakLabel);
	}

	asm.add(newctx.breakLabel);
	}

	/**
	* 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>");
	}
	for (int i = 0 ; i < args.length ; i++) {
	out.print(" ");
	args[i].print(out, indent);
	}
	}
	}

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