Java example source code file (CatchStatement.java)

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Java - Java tags/keywords

catchstatement, classdefinition, classnotfound, codecontext, context, deprecated, expression, identifier, identifiertoken, localmember, localvariable, statement, type, util, vset

The CatchStatement.java Java example source code

/*
 * 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>");
        }
    }
}