Add a security manager that trap System.exit() calls.

Note that this is added in Main only for JDK1.2+
since it looks like the SM is not that friendly
for previous versions.


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@270147 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/ExitException.java

@@ -56,6 +56,8 @@ package org.apache.tools.ant;
 /**
  * Used to report exit status of classes which call System.exit()
  *
+ * @see NoExitSecurityManager
+ *
  * @author Conor MacNeill
  */
 public class ExitException extends SecurityException {
@@ -64,12 +66,16 @@ public class ExitException extends SecurityException {
     
     /**
      * Constructs an exit exception.
+     * @param status the status code returned via System.exit()
      */
     public ExitException(int status) {
         super("ExitException: status " + status);
         this.status = status;
     }
 
+    /**
+     * @return the status code return via System.exit()
+     */
     public int getStatus() {
         return status;
     }

src/main/org/apache/tools/ant/Main.java

@@ -417,8 +417,15 @@ public class Main {
 
             PrintStream err = System.err;
             PrintStream out = System.out;
-            SecurityManager oldsm = System.getSecurityManager();
 
+            // use a system manager that prevents from System.exit()
+            // only in JDK > 1.1
+            SecurityManager oldsm = null;
+            if ( !Project.JAVA_1_0.equals(Project.getJavaVersion()) &&
+                !Project.JAVA_1_1.equals(Project.getJavaVersion()) ){
+                oldsm = System.getSecurityManager();
+                System.setSecurityManager(new NoExitSecurityManager());
+            }
             try {
                 System.setOut(new PrintStream(new DemuxOutputStream(project, false)));
                 System.setErr(new PrintStream(new DemuxOutputStream(project, true)));
@@ -468,6 +475,10 @@ public class Main {
                 project.executeTargets(targets);
             }
             finally {
+                // put back the original security manager
+                if (oldsm != null){
+                    System.setSecurityManager(oldsm);
+                }
                 System.setOut(out);
                 System.setErr(err);
             }

src/main/org/apache/tools/ant/NoExitSecurityManager.java

@@ -0,0 +1,76 @@
+/*
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2001 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Ant", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Group.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+package org.apache.tools.ant;
+
+import java.security.Permission;
+
+/**
+ * This is intended as a replacement for the default system manager.
+ * The goal is to intercept System.exit calls and make it throw an
+ * exception instead so that a System.exit in a task does not
+ * fully terminate Ant.
+ *
+ * @see ExitException
+ * @author <a href="mailto:sbailliez@apache.org">Stephane Bailliez</a>
+ */
+public class NoExitSecurityManager extends SecurityManager {
+
+    public void checkExit(int status) {
+        throw new ExitException(status);
+    }
+
+    public void checkPermission(Permission perm) {
+        // no permission here
+    }
+}