Add OpenVMS support to <exec>.

PR: 21877
Submitted by:	Knut Wannheden <knut at paranor dot ch>


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@274949 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -513,6 +513,9 @@ Other changes:
   mappings per source path. This behaviour is enabled by using
   an enablemultiplemapping attribute. Bugzilla Report 21320.
 
+* <exec> will now work on OpenVMS (please read the notes in
+  <exec>'s manual page).  Bugzilla Report 21877.  
+
 Changes from Ant 1.5.2 to Ant 1.5.3
 ===================================
 

docs/manual/CoreTasks/exec.html

@@ -19,6 +19,14 @@ the executable parameter. This is because the Java VM in which Ant is running is
 Windows executable and is not aware of Cygwin conventions.
 </p>
  
+<h4>OpenVMS Users</h4>
+<p>The command specified using <code>executable</code> and <code>&lt;arg&gt;</code>
+elements is executed exactly as specified inside a temporary DCL script.  This means
+that paths have to be written in VMS style.  It is also required that the logical
+<code>JAVA$FORK_SUPPORT_CHDIR</code> is set to <code>TRUE</code> (see the <i>JDK Release
+Notes</i>).
+</p>
+ 
 <h3>Parameters</h3>
 <table border="1" cellpadding="2" cellspacing="0">
   <tr>
@@ -108,7 +116,7 @@ Windows executable and is not aware of Cygwin conventions.
   <tr>
     <td valign="top">resultproperty</td>
     <td valign="top">the name of a property in which the return code of the 
-      command should be stored. Only of interest if failonerror=false</td>
+      command should be stored. Only of interest if failonerror=false.</td>
     <td align="center" valign="top">No</td>
   </tr>
   <tr>
@@ -120,7 +128,7 @@ Windows executable and is not aware of Cygwin conventions.
   <tr>
     <td valign="top">failonerror</td>
     <td valign="top">Stop the buildprocess if the command exits with a
-      returncode other than 0. Defaults to false</td>
+      return code signaling failure. Defaults to false.</td>
     <td align="center" valign="top">No</td>
   </tr>
   <tr>
@@ -204,15 +212,15 @@ system command via nested <code>&lt;env&gt;</code> elements.</p>
 
 <h3>Errors and return codes</h3>
 By default the return code of a &lt;exec&gt; is ignored; when you set 
-<code>failonerror="true"</code> then any non zero response is treated as an
-error. Alternatively, you can set <code>resultproperty</code> to the name
-of a property and have it assigned to the result code (barring immutability,
-of course).
+<code>failonerror="true"</code> then any return code signaling failure
+(OS specific) causes the build to fail. Alternatively, you can set
+<code>resultproperty</code> to the name of a property and have it assigned to
+the result code (barring immutability, of course).
 <p>
 If the attempt to start the program fails with an OS dependent error code,
 then &lt;exec&gt; halts the build unless <code>failifexecutionfails</code>
-is set. You can use that to run a program if it exists, but otherwise 
-do nothing.
+is set to <code>false</code>. You can use that to run a program if it exists, but
+otherwise do nothing.
 <p>
 What do those error codes mean? Well, they are OS dependent. On Windows
 boxes you have to look in include\error.h in your windows compiler or wine files;

src/main/org/apache/tools/ant/taskdefs/ExecTask.java

@@ -413,7 +413,7 @@ public class ExecTask extends Task {
             log("Timeout: killed the sub-process", Project.MSG_WARN);
         }
         maybeSetResultPropertyValue(returnCode);
-        if (returnCode != 0) {
+        if (Execute.isFailure(returnCode)) {
             if (failOnError) {
                 throw new BuildException(getTaskType() + " returned: "
                     + returnCode, getLocation());

src/main/org/apache/tools/ant/taskdefs/Execute.java

@@ -57,7 +57,9 @@ package org.apache.tools.ant.taskdefs;
 import java.io.BufferedReader;
 import java.io.ByteArrayOutputStream;
 import java.io.File;
+import java.io.FileWriter;
 import java.io.IOException;
+import java.io.PrintWriter;
 import java.io.StringReader;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
@@ -109,7 +111,9 @@ public class Execute {
     static {
         // Try using a JDK 1.3 launcher
         try {
-            if (!Os.isFamily("os/2")) {
+            if (Os.isFamily("openvms")) {
+                vmLauncher = new VmsCommandLauncher();
+            } else if (!Os.isFamily("os/2")) {
                 vmLauncher = new Java13CommandLauncher();
             }
         } catch (NoSuchMethodException exc) {
@@ -155,6 +159,9 @@ public class Execute {
 
             shellLauncher
                 = new PerlScriptCommandLauncher("bin/antRun.pl", baseLauncher);
+        } else if (Os.isFamily("openvms")) {
+            // the vmLauncher already uses the shell
+            shellLauncher = vmLauncher;
         } else {
             // Generic
             shellLauncher = new ScriptCommandLauncher("bin/antRun",
@@ -249,6 +256,9 @@ public class Execute {
             // rely on PATH
             String[] cmd = {"env"};
             return cmd;
+        } else if (Os.isFamily("openvms")) {
+            String[] cmd = {"show", "logical"};
+            return cmd;
         } else {
             // MAC OS 9 and previous
             // TODO: I have no idea how to get it, someone must fix it
@@ -490,14 +500,30 @@ public class Execute {
     }
 
     /**
-     * query the exit value of the process.
+     * Query the exit value of the process.
      * @return the exit value, 1 if the process was killed,
-     * or Project.INVALID if no exit value has been received
+     * or Execute.INVALID if no exit value has been received
      */
     public int getExitValue() {
         return exitValue;
     }
 
+    /**
+     * Checks whether <code>exitValue</code> signals a failure on the current
+     * system (OS specific).
+     * @param exitValue the exit value (return code) to be checked
+     * @return <code>true</code> if <code>exitValue</code> signals a failure
+     */
+    public static boolean isFailure(int exitValue) {
+        if (Os.isFamily("openvms")) {
+            // odd exit value signals failure
+            return (exitValue % 2) == 0;
+        } else {
+            // non zero exit value signals failure
+            return exitValue != 0;
+        }
+    }
+
     /**
      * test for an untimely death of the process
      * @return true iff a watchdog had to kill the process
@@ -912,4 +938,61 @@ public class Execute {
 
         private String _script;
     }
+    
+    /**
+     * A command launcher for VMS that writes the command to a temporary DCL
+     * script before launching commands.  This is due to limitations of both
+     * the DCL interpreter and the Java VM implementation.
+     */
+    private static class VmsCommandLauncher extends Java13CommandLauncher {
+
+        public VmsCommandLauncher() throws NoSuchMethodException {
+            super();
+        }
+
+        /**
+         * Launches the given command in a new process.
+         */
+        public Process exec(Project project, String[] cmd, String[] env)
+            throws IOException {
+            String[] vmsCmd = { createCommandFile(cmd).getPath() };
+            return super.exec(project, vmsCmd, env);
+        }
+
+        /**
+         * Launches the given command in a new process, in the given working
+         * directory.  Note that under Java 1.3.1, 1.4.0 and 1.4.1 on VMS this
+         * method only works if <code>workingDir</code> is null or the logical
+         * JAVA$FORK_SUPPORT_CHDIR needs to be set to TRUE.
+         */
+        public Process exec(Project project, String[] cmd, String[] env,
+                            File workingDir) throws IOException {
+            String[] vmsCmd = { createCommandFile(cmd).getPath() };
+            return super.exec(project, vmsCmd, env, workingDir);
+        }
+
+        /*
+         * Writes the command into a temporary DCL script and returns the
+         * corresponding File object.  The script will be deleted on exit.
+         */
+        private File createCommandFile(String[] cmd) throws IOException {
+            File script = File.createTempFile("ANT", ".COM");
+            script.deleteOnExit();
+            PrintWriter out = null;
+            try {
+                out = new PrintWriter(new FileWriter(script));
+                StringBuffer dclCmd = new StringBuffer("$");
+                for (int i = 0; i < cmd.length; i++) {
+                    dclCmd.append(' ').append(cmd[i]);
+                }
+                out.println(dclCmd.toString());
+            } finally {
+                if (out != null) {
+                    out.close();
+                }
+            }                
+            return script;
+        }
+
+    }
 }