ant: stdout lost over serial console; fork=true NPE; requires public class

[LSantha]

Summary

ant (Apache Ant 1.7.1 wrapper, org.jnode.command.dev.ant.AntCommand) works for compiling Java and running code, but:

1. Ant's stdout does not stream over the serial console. Only Buildfile: build.xml (and occasionally part of the target list) appears; BUILD SUCCESSFUL, <echo> task messages, and program System.out are missing from serial output — even though the build actually succeeds and side effects happen.
2. <java fork="true"> throws a hard JVM-level NullPointerException and the task produces no output/side effect.
3. <java fork="false"> requires an explicit <classpath>, and additionally the target class must be public — a package-private class fails with IllegalAccessException from org.apache.tools.ant.taskdefs.ExecuteJava.
4. <javac srcdir="." destdir="."/> compiles fine, and other tasks such as <touch> work — so the issue is not that ant "does nothing", only that its console output is routed away from the serial console.

Repro (JNode all-plugins boot /full.jgz, serial agent console)

All files under /devices/hdb1/devtest/ant1 (JFAT).

1. Ant compile+run with a public class — output invisible over serial

WH3.java:

public class WH3 { public static void main(String[] a) throws Exception {
  java.io.PrintWriter w = new java.io.PrintWriter(new java.io.FileOutputStream("/devices/hdb1/devtest/ant1/wh3.txt"));
  w.println("WH3 RAN"); w.close(); System.out.println("WH3_SYS_OUT");
} }

build.xml:

<project name="t" default="job">
  <target name="job">
    <javac srcdir="." destdir="."/>
    <java classname="WH3" fork="false" failonerror="true">
      <classpath location="."/>
    </java>
  </target>
</project>

Serial output:

Buildfile: build.xml

Expected: [javac], [java], WH3_SYS_OUT, BUILD SUCCESSFUL, Total time. None appear — but wh3.txt is created (8 bytes WH3 RAN), proving the class ran. So ant output (streams) IS lost over serial; execution works.

2. fork="true" breaks

Same build root with fork="true":
Serial output:

Buildfile: build.xml
java.lang.NullPointerException: NPE at address 3CDFE8D6

No wh3.txt created, no class output — ExecuteJava crashes when forking.

3. package-private class + fork="false"

WriteHello2 (no public on the class), built with:

<java classname="WriteHello2" fork="false" failonerror="true">
  <classpath location="/devices/hdb1/devtest/ant1"/>
</java>

Serial output:

Buildfile: build.xml
java.lang.IllegalAccessException: Class org.apache.tools.ant.taskdefs.ExecuteJava can not access a member of class WriteHello2 with modifiers "public static"

(The same class runs fine with the shell's java WriteHello2 from that directory, which uses JCClassLoader + reflection and accepts non-public classes.)

Observations / Analysis

• Ant output and serial: only Buildfile: goes to the serial buffer. BUILD SUCCESSFUL, [echo], [javac], and program stdout are swallowed (buffered at the ant Project/BuildLogger level, presumably because the task's System.out uses a non-flushing buffered stream that is lost). This is the reason the common "ant does nothing" impression exists for serial usage.
• WORKAROUND (for serial): ant reliably runs/compiles; verify by side effects (a file the code creates, ls -l timestamps, etc.), and keep target classes public. If you need direct stdout over the agent, use javac + java shell commands (see jnode-serial/jnode-java-coding skills) instead of ant.
• This VM used this all-plugins image/JFAT /devices/hdb1/devtest and the automatic serial console (SerialConsolePlugin, UART2 /tmp/jnode.serialpipe).

Suggested fixes

1. Make the ant wrapper (or the AntCommand) brief flush the Project logger / redirect ant log through an output stream that the shell flushes, so [echo], [javac], BUILD SUCCESSFUL reach the serial console.
2. Fix ExecuteJava / forking path to avoid the fork=true NPE (possibly implement forking with a JNode-owned JVM invocation or document that fork is unsupported).
3. After fix Fix typo in Unsafe.java class doc: "directy" → "direct" #1, nothing else required — ant will be usable over serial; non-public classes continue to require the shell java.

[LSantha]

Superseded — this report bundled three independent bugs. Split into:

• ant: console output (BUILD SUCCESSFUL, [echo], [javac], program stdout) is lost over the serial console #597 — ant: console output (BUILD SUCCESSFUL, [echo], [javac], program stdout) is lost over the serial console
• ant: <java fork="true"> throws NullPointerException (NPE at address ...) and never runs the class #598 — ant: throws NullPointerException and never runs the class
• ant: <java fork="false"> cannot run a package-private class (IllegalAccessException); shell java can #599 — ant: cannot run a package-private class (IllegalAccessException)