Issue trying to use CORBA classes from javac

[Alan Bateman]

On 23/05/2016 13:51, Andrew Dinn wrote:
> Hi All,
>
> Red Hat's Transactions developers are having problems compiling their
> Corba-based code using the latest early access release of JDK9
> (9-ea-b119). When the maven compiler plugin executes javac the compile
> fails because various corba packages are not visible. These are /not/
> classes belonging to concealed packages.
>
> Some of the relevant error messages are shown in the first listing
> following my sig.
>
> Indeed, what is more strange is that we found that we could remedy the
> first of these errors by adding an explicit addExports for the relevant
> package to the javac arguments configured in the maven pom:
>
>    <compilerArgs>
>      <arg>-XaddExports:java.corba/org.omg.CORBA=ALL-UNNAMED</arg>
>    </compilerArgs>
>
> The second listing shows the difference this makes. Note that package
> org.omg.CORBA is now recognised.
>
>
> No doubt the same sort of fix would apply to remove the other errors but
> I don't understand why the use of addExports is necessary. When I run
> jmod describe on the java.corba module it tells me that org.omg.CORBA
> etc are already exported. So, java.corba does not seem to be a special
> sort of package different to all the others in the jmod dir.
>
> Is there some hidden switch which disables exports for this module? If
> so then is there a switch (equally as well hidden :-) which allows me to
> re-instate them? If not then does anyone have any idea why are we seeing
> these missing package errors?
>
> n.b. please keep Mike Musgrove in the cc for any replies as he is not
> subscribed to this list.
>
As Sander said, compiling with `-addmods java.corba` will ensure that 
the java.corba module is resolved.

That said, I'm puzzled as to why -XaddExports makes a difference here, 
also by some of the types mentioned in the compilation messages as they 
aren't types in the JDK java.corba module.

It would help if you or Michael could summarize what org.omg.** classes 
are in the environment. We've had problems off-list with another app 
server in this area too. In that case, it was augmenting the CORBA 
version in the JDK with additional classes as part of adding support for 
OMG APIs that the JDK version doesn't support. I don't know if we've got 
something similar here. If so, then bring a packed lunch as it will be a 
long day :-)

-Alan