/*
 * Copyright (c) 2017, 2019, 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
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package com.oracle.svm.core.posix;

import org.graalvm.nativeimage.c.type.CCharPointer;
import org.graalvm.nativeimage.c.type.CTypeConversion;
import org.graalvm.word.WordFactory;

import com.oracle.svm.core.graal.stackvalue.UnsafeStackValue;
import com.oracle.svm.core.jdk.SystemPropertiesSupport;
import com.oracle.svm.core.posix.headers.Limits;
import com.oracle.svm.core.posix.headers.Unistd;

public abstract class PosixSystemPropertiesSupport extends SystemPropertiesSupport {

    /*
     * Initialization code is adapted from the JDK native code that initializes the system
     * properties, as found in src/solaris/native/java/lang/java_props_md.c
     */

    @Override
    protected String userNameValue() {
        String name = PosixUtils.getUserName(Unistd.getuid());
        return name == null ? "?" : name;
    }

    @Override
    protected String userHomeValue() {
        String dir = PosixUtils.getUserDir(Unistd.getuid());
        return dir == null ? "?" : dir;
    }

    @Override
    protected String userDirValue() {
        int bufSize = Limits.MAXPATHLEN();
        CCharPointer buf = UnsafeStackValue.get(bufSize);
        if (Unistd.getcwd(buf, WordFactory.unsigned(bufSize)).isNonNull()) {
            return CTypeConversion.toJavaString(buf);
        } else {
            throw new java.lang.Error("Properties init: Could not determine current working directory.");
        }
    }
}
