Why GCJ won't load my plugin when compiling bytecode?

Fri Sep 9 20:57:00 GMT 2011

Hi there,
I have a java source code Welcome.java, and my plugin's name is findvar.so.
To avoid things getting complex, I write a very simple plugin,
printing out Hello
when loaded(printing hello in initial function).
My plugin can be loaded if GCJ compiles source code to native machine code,
that is if I type:
 gcj-4.6 -fplugin=findvar.so Welcome.java --main=Welcome
Hello is then output to screen, and a.out is produced.
But it won't work if GCJ compiles source code to java bytecode
 gcj-4.6 -fplugin=findvar.so -C Welcome.java --main=Welcome
Nothing is promoted, only Welcome.class is produced.
Does that mean that GCJ doesn't support -C and -fplugin at the same time?
I really appreciate your answer.
J. Li