Java example source code file (ThrowStatement.java)

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Java - Java tags/keywords

assembler, checkcontext, classdeclaration, classdefinition, classnotfound, context, dead_end, environment, expression, hashtable, statement, throwstatement, util, vset

The ThrowStatement.java Java example source code

/*
 * 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 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 ThrowStatement extends Statement {
    Expression expr;

    /**
     * Constructor
     */
    public ThrowStatement(long where, Expression expr) {
        super(THROW, where);
        this.expr = expr;
    }

    /**
     * Check statement
     */
    Vset check(Environment env, Context ctx, Vset vset, Hashtable exp) {
        checkLabel(env, ctx);
        try {
            vset = reach(env, vset);
            expr.checkValue(env, ctx, vset, exp);
            if (expr.type.isType(TC_CLASS)) {
                ClassDeclaration c = env.getClassDeclaration(expr.type);
                if (exp.get(c) == null) {
                    exp.put(c, this);
                }
                ClassDefinition def = c.getClassDefinition(env);
                ClassDeclaration throwable =
                    env.getClassDeclaration(idJavaLangThrowable);
                if (!def.subClassOf(env, throwable)) {
                    env.error(where, "throw.not.throwable", def);
                }
                expr = convert(env, ctx, Type.tObject, expr);
            } else if (!expr.type.isType(TC_ERROR)) {
                env.error(expr.where, "throw.not.throwable", expr.type);
            }
        } catch (ClassNotFound e) {
            env.error(where, "class.not.found", e.name, opNames[op]);
        }
        CheckContext exitctx = ctx.getTryExitContext();
        if (exitctx != null) {
            exitctx.vsTryExit = exitctx.vsTryExit.join(vset);
        }
        return DEAD_END;
    }

    /**
     * Inline
     */
    public Statement inline(Environment env, Context ctx) {
        expr = expr.inlineValue(env, ctx);
        return this;
    }

    /**
     * Create a copy of the statement for method inlining
     */
    public Statement copyInline(Context ctx, boolean valNeeded) {
        ThrowStatement s = (ThrowStatement)clone();
        s.expr = expr.copyInline(ctx);
        return s;
    }

    /**
     * The cost of inlining this statement
     */
    public int costInline(int thresh, Environment env, Context ctx) {
        return 1 + expr.costInline(thresh, env, ctx);
    }

    /**
     * Code
     */
    public void code(Environment env, Context ctx, Assembler asm) {
        expr.codeValue(env, ctx, asm);
        asm.add(where, opc_athrow);
    }

    /**
     * Print
     */
    public void print(PrintStream out, int indent) {
        super.print(out, indent);
        out.print("throw ");
        expr.print(out);
        out.print(":");
    }
}