Java example source code file (NASHORN-653.js)

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Java - Java tags/keywords

asm, bytearrayoutputstream, javaimporter, nashornscriptenginefactory, nop, nop*/athrow, printstream

The NASHORN-653.js Java example source code

/*
 * Copyright (c) 2010, 2013, 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.
 * 
 * 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.
 */

/**
 * NASHORN-653 : Various problems with isTerminal and dead code generation from ASM
 *
 * @test
 * @run
 */

var script = "   \
function a() {   \
    return true; \
}                \
                 \
function b() {   \
    while (x) {      \
	return true; \
    }                \
}                    \
                     \
function c() {       \
    while (true) {   \
	return true; \
    }                \
 }                   \
                     \
function d() {       \
    do {             \
	return true; \
    } while (x);     \
} \
\
function f() {       \
    for (;;) {       \
	return true; \
    } \
} \
\
function e() { \
    for (;;) { \
	return true; \
    } \
} \
\
function g() { \
    for(;;) { \
	print('goes on and on and on ... '); \
    } \
    print('x'); \
} \
";

function runScriptEngine(opts, code) {
    var imports = new JavaImporter(
        Packages.jdk.nashorn.api.scripting,
        java.io, java.lang, java.util);

    with(imports) {
        var fac = new NashornScriptEngineFactory();
        // get current System.err
        var oldErr = System.err;
        var baos = new ByteArrayOutputStream();
        var newErr = new PrintStream(baos);
        try {
            // set new standard err
            System.setErr(newErr);
            var engine = fac.getScriptEngine(Java.to(opts, "java.lang.String[]"));
            engine.eval(code);
            newErr.flush();
            return new java.lang.String(baos.toByteArray());
        } finally {
            // restore System.err to old value
            System.setErr(oldErr);
        }
    }
}

var result = runScriptEngine([ "--print-code" ], script);

if (result.indexOf("NOP") != -1) {
    fail("ASM genenerates NOP*/ATHROW sequences - dead code is still in the script");
}