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 * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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
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package org.graalvm.compiler.hotspot;

import static jdk.vm.ci.common.InitTimer.timer;

import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.Map;
import java.util.Properties;

import org.graalvm.collections.EconomicMap;
import org.graalvm.compiler.options.Option;
import org.graalvm.compiler.options.OptionDescriptors;
import org.graalvm.compiler.options.OptionKey;
import org.graalvm.compiler.options.OptionValues;
import org.graalvm.compiler.options.OptionsParser;

import jdk.vm.ci.common.InitTimer;
import jdk.vm.ci.common.NativeImageReinitialize;
import jdk.vm.ci.services.Services;

The defaultOptions() method returns the options values initialized in a HotSpot VM. The values are set via system properties with the "graal." prefix. /**
 * The {@link #defaultOptions()} method returns the options values initialized in a HotSpot VM. The
 * values are set via system properties with the {@value #GRAAL_OPTION_PROPERTY_PREFIX} prefix.
 */
public class HotSpotGraalOptionValues {

    
The name of the system property specifying a file containing extra Graal option settings.
/**
     * The name of the system property specifying a file containing extra Graal option settings.
     */
    private static final String GRAAL_OPTIONS_FILE_PROPERTY_NAME = "graal.options.file";

    
The name of the system property specifying the Graal version.
/**
     * The name of the system property specifying the Graal version.
     */
    private static final String GRAAL_VERSION_PROPERTY_NAME = "graal.version";

    
The prefix for system properties that correspond to Option annotated fields. A field named MyOption will have its value set from a system property with the name GRAAL_OPTION_PROPERTY_PREFIX + "MyOption". /**
     * The prefix for system properties that correspond to {@link Option} annotated fields. A field
     * named {@code MyOption} will have its value set from a system property with the name
     * {@code GRAAL_OPTION_PROPERTY_PREFIX + "MyOption"}.
     */
    public static final String GRAAL_OPTION_PROPERTY_PREFIX = "graal.";

    
Gets the system property assignment that would set the current value for a given option.
/**
     * Gets the system property assignment that would set the current value for a given option.
     */
    public static String asSystemPropertySetting(OptionValues options, OptionKey<?> value) {
        return GRAAL_OPTION_PROPERTY_PREFIX + value.getName() + "=" + value.getValue(options);
    }

    @NativeImageReinitialize private static volatile OptionValues hotspotOptions;

    public static OptionValues defaultOptions() {
        OptionValues res = hotspotOptions;
        if (res == null) {
            synchronized (HotSpotGraalOptionValues.class) {
                res = hotspotOptions;
                if (res == null) {
                    res = initializeOptions();
                    hotspotOptions = res;
                }
            }
        }
        return res;
    }

    
Gets and parses options based on saved system
properties. The values for these options are initialized by parsing the file denoted by the "graal.options.file" property followed by parsing the options encoded in properties whose names start with "graal.". Key/value pairs are parsed from the aforementioned file with Properties.load(Reader). /**
     * Gets and parses options based on {@linkplain Services#getSavedProperties() saved system
     * properties}. The values for these options are initialized by parsing the file denoted by the
     * {@value #GRAAL_OPTIONS_FILE_PROPERTY_NAME} property followed by parsing the options encoded
     * in properties whose names start with {@value #GRAAL_OPTION_PROPERTY_PREFIX}. Key/value pairs
     * are parsed from the aforementioned file with {@link Properties#load(java.io.Reader)}.
     */
    @SuppressWarnings("try")
    public static EconomicMap<OptionKey<?>, Object> parseOptions() {
        EconomicMap<OptionKey<?>, Object> values = OptionValues.newOptionMap();
        try (InitTimer t = timer("InitializeOptions")) {

            Iterable<OptionDescriptors> loader = OptionsParser.getOptionsLoader();
            Map<String, String> savedProps = jdk.vm.ci.services.Services.getSavedProperties();
            String optionsFile = savedProps.get(GRAAL_OPTIONS_FILE_PROPERTY_NAME);

            if (optionsFile != null) {
                File graalOptions = new File(optionsFile);
                if (graalOptions.exists()) {
                    try (FileReader fr = new FileReader(graalOptions)) {
                        Properties props = new Properties();
                        props.load(fr);
                        EconomicMap<String, String> optionSettings = EconomicMap.create();
                        for (Map.Entry<Object, Object> e : props.entrySet()) {
                            optionSettings.put((String) e.getKey(), (String) e.getValue());
                        }
                        try {
                            OptionsParser.parseOptions(optionSettings, values, loader);
                        } catch (Throwable e) {
                            throw new InternalError("Error parsing an option from " + graalOptions, e);
                        }
                    } catch (IOException e) {
                        throw new InternalError("Error reading " + graalOptions, e);
                    }
                }
            }

            EconomicMap<String, String> optionSettings = EconomicMap.create();
            for (Map.Entry<String, String> e : savedProps.entrySet()) {
                String name = e.getKey();
                if (name.startsWith(GRAAL_OPTION_PROPERTY_PREFIX)) {
                    if (name.equals("graal.PrintFlags") || name.equals("graal.ShowFlags")) {
                        System.err.println("The " + name + " option has been removed and will be ignored. Use -XX:+JVMCIPrintProperties instead.");
                    } else if (name.equals(GRAAL_OPTIONS_FILE_PROPERTY_NAME) || name.equals(GRAAL_VERSION_PROPERTY_NAME)) {
                        // Ignore well known properties that do not denote an option
                    } else {
                        String value = e.getValue();
                        optionSettings.put(name.substring(GRAAL_OPTION_PROPERTY_PREFIX.length()), value);
                    }
                }
            }

            OptionsParser.parseOptions(optionSettings, values, loader);
            return values;
        }
    }

    
Substituted by com.oracle.svm.graal.hotspot.libgraal.Target_org_graalvm_compiler_hotspot_HotSpotGraalOptionValues to update com.oracle.svm.core.option.RuntimeOptionValues.singleton() instead of creating a new OptionValues object. /**
     * Substituted by
     * {@code com.oracle.svm.graal.hotspot.libgraal.Target_org_graalvm_compiler_hotspot_HotSpotGraalOptionValues}
     * to update {@code com.oracle.svm.core.option.RuntimeOptionValues.singleton()} instead of
     * creating a new {@link OptionValues} object.
     */
    private static OptionValues initializeOptions() {
        return new OptionValues(parseOptions());
    }
}