file based profile activation - best practice ?

[nicolas de loof]

Hello,

I'm using a code generator, and I'd like to avoid regeneration of code on
each build.

I've set a profile to launch the generation using the antrun plugin
The profile is active based on a generated file missing :

<profile>
      <id>sql2java</id>
      <activation>
        <file>
          <missing>target/generated-sources/sql2java.tstamp</missing>
        </file>
      </activation>
      <build>
...

As explained in http://docs.codehaus.org/display/MAVENUSER/Profiles, I
cannot reference ${project.build.directory} in this path.
When I run "mvn install" from my parent POM, generator runs even if code
allready exist, as the project basedir is not the same as running from the
module.

Is there any way to solve this ? Is there any plan for properties support in
profiles activation ?

Nico.