1 /*
   2  * Copyright (c) 2015, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 package org.graalvm.compiler.test;
  24 
  25 import java.io.File;
  26 import java.io.IOException;
  27 import java.nio.file.Files;
  28 import java.util.Arrays;
  29 import java.util.List;
  30 
  31 /**
  32  * Utility methods for spawning a VM in a subprocess during unit tests.
  33  */
  34 public final class SubprocessUtil {
  35 
  36     private SubprocessUtil() {
  37     }
  38 
  39     /**
  40      * Gets the command line for the current process.
  41      *
  42      * @return the command line arguments for the current process or {@code null} if they are not
  43      *         available
  44      */
  45     public static List<String> getProcessCommandLine() {
  46         String processArgsFile = System.getenv().get("MX_SUBPROCESS_COMMAND_FILE");
  47         if (processArgsFile != null) {
  48             try {
  49                 return Files.readAllLines(new File(processArgsFile).toPath());
  50             } catch (IOException e) {
  51             }
  52         }
  53         return null;
  54     }
  55 
  56     /**
  57      * Gets the command line used to start the current Java VM, including all VM arguments, but not
  58      * including the main class or any Java arguments. This can be used to spawn an identical VM,
  59      * but running different Java code.
  60      */
  61     public static List<String> getVMCommandLine() {
  62         List<String> args = getProcessCommandLine();
  63         if (args == null) {
  64             return null;
  65         } else {
  66             int index = findMainClassIndex(args);
  67             return args.subList(0, index);
  68         }
  69     }
  70 
  71     public static final List<String> JVM_OPTIONS_WITH_ONE_ARG = System.getProperty("java.specification.version").compareTo("1.9") < 0 ? //
  72                     Arrays.asList("-cp", "-classpath") : //
  73                     Arrays.asList("-cp", "-classpath", "-mp", "-modulepath", "-upgrademodulepath", "-addmods", "-m", "-limitmods");
  74 
  75     private static int findMainClassIndex(List<String> commandLine) {
  76         int i = 1; // Skip the java executable
  77 
  78         while (i < commandLine.size()) {
  79             String s = commandLine.get(i);
  80             if (s.charAt(0) != '-') {
  81                 return i;
  82             } else if (JVM_OPTIONS_WITH_ONE_ARG.contains(s)) {
  83                 i += 2;
  84             } else {
  85                 i++;
  86             }
  87         }
  88         throw new InternalError();
  89     }
  90 
  91 }