CatchStatement.java

/*
 * 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.LocalVariable;
import sun.tools.asm.Label;
import java.io.PrintStream;
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 CatchStatement extends Statement {
    int mod;
    Expression texpr;
    Identifier id;
    Statement body;
    LocalMember field;

    /**
     * Constructor
     */
    public CatchStatement(long where, Expression texpr, IdentifierToken id, Statement body) {
	super(CATCH, where);
	this.mod = id.getModifiers();
	this.texpr = texpr;
	this.id = id.getName();
	this.body = body;
    }
    /** @deprecated */
    @Deprecated
    public CatchStatement(long where, Expression texpr, Identifier id, Statement body) {
	super(CATCH, where);
	this.texpr = texpr;
	this.id = id;
	this.body = body;
    }

    /**
     * Check statement
     */
    Vset check(Environment env, Context ctx, Vset vset, Hashtable exp) {
	vset = reach(env, vset);
	ctx = new Context(ctx, this);
	Type type = texpr.toType(env, ctx);

	try {
	    if (ctx.getLocalField(id) != null) {
		env.error(where, "local.redefined", id);
	    }

	    if (type.isType(TC_ERROR)) { 
		// error message printed out elsewhere
	    } else if (!type.isType(TC_CLASS)) {
		env.error(where, "catch.not.throwable", type);
	    } else { 
		ClassDefinition def = env.getClassDefinition(type);
		if (!def.subClassOf(env, 
			       env.getClassDeclaration(idJavaLangThrowable))) {
		    env.error(where, "catch.not.throwable", def);
		}
	    }

	    field = new LocalMember(where, ctx.field.getClassDefinition(), mod, type, id);
	    ctx.declare(env, field);
	    vset.addVar(field.number);

	    return body.check(env, ctx, vset, exp);
	} catch (ClassNotFound e) {
	    env.error(where, "class.not.found", e.name, opNames[op]);
	    return vset;
	}
    }

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

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

    /**
     * Compute cost of inlining this statement
     */
    public int costInline(int thresh, Environment env, Context ctx){
	int cost = 1;
        if (body != null) {
            cost += body.costInline(thresh, env,ctx);
        }
        return cost;
    }
    
    /**
     * Code
     */
    public void code(Environment env, Context ctx, Assembler asm) {
	CodeContext newctx = new CodeContext(ctx, this);
	if (field.isUsed()) {
	    newctx.declare(env, field);
	    asm.add(where, opc_astore, new LocalVariable(field, field.number));
	} else {
	    asm.add(where, opc_pop);
	}
	if (body != null) {
	    body.code(env, newctx, asm);
	}
	//asm.add(newctx.breakLabel);
    }

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