Add pathref attribute to <arg>.

PR: 13137


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@273404 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -49,6 +49,9 @@ Other changes:
 
 * OS/400 now gets detected by the os condition.
 
+* <arg> has a new attribute pathref that can be used to reference
+  previously defined paths.
+
 Changes from Ant 1.5.1Beta1 to 1.5.1
 ====================================
 

docs/manual/using.html

@@ -429,7 +429,7 @@ that contain space characters, nested <code>arg</code> elements can be used.</p>
     <td valign="top">value</td>
     <td valign="top">a single command-line argument; can contain space
       characters.</td>
-    <td align="center" rowspan="4">Exactly one of these.</td>
+    <td align="center" rowspan="5">Exactly one of these.</td>
   </tr>
   <tr>
     <td valign="top">file</td>
@@ -444,6 +444,12 @@ that contain space characters, nested <code>arg</code> elements can be used.</p>
       path separators and Ant will convert it to the platform's local
       conventions.</td>
   </tr>
+  <tr>
+    <td valign="top">pathref</td>
+    <td valign="top"><a href="#references">Reference</a> to a path
+      defined elsewhere.  Ant will convert it to the platform's local
+      conventions.</td>
+  </tr>
   <tr>
     <td valign="top">line</td>
     <td valign="top">a space-delimited list of command-line arguments.</td>

src/main/org/apache/tools/ant/types/Commandline.java

@@ -58,6 +58,7 @@ import java.io.File;
 import java.util.StringTokenizer;
 import java.util.Vector;
 import org.apache.tools.ant.BuildException;
+import org.apache.tools.ant.ProjectComponent;
 import org.apache.tools.ant.util.StringUtils;
 
 
@@ -113,7 +114,7 @@ public class Commandline implements Cloneable {
     /**
      * Used for nested xml command line definitions.
      */
-    public static class Argument {
+    public static class Argument extends ProjectComponent {
 
         private String[] parts;
 
@@ -149,6 +150,19 @@ public class Commandline implements Cloneable {
             parts = new String[] {value.toString()};
         }
 
+        /**
+         * Sets a single commandline argument from a reference to a
+         * path - ensures the right separator for the local platform
+         * is used.
+         *
+         * @param value a single commandline argument.
+         */
+        public void setPathref(Reference value) {
+            Path p = new Path(getProject());
+            p.setRefid(value);
+            parts = new String[] {p.toString()};
+        }
+
         /**
          * Sets a single commandline argument to the absolute filename
          * of the given file.