Open modules export all packages just like unnamed modules

[DanHeidinga]

Update the isPackageExportedToModuleHelper function to treat open
modules exactly like unnamed ones. All packages in such modules
should be treated as exported.

fixes #1789

Signed-off-by: Dan Heidinga daniel_heidinga@ca.ibm.com

[DanHeidinga]

Marking as "WIP" as I'm having trouble re-building the petclinic modularity demo to validate this change.

[DanHeidinga]

I haven't been able to confirm if this fixes petclinic yet but have confirmation that other open module tests are passing. This is at least a positive step forward

[JasonFengJ9]

The change looks good.

Just noticed that visible.c:checkModuleAccess() can check unnamed | open modules which export all packages, hence skip the call to isPackageExportedToModuleWithName(). I think this can be done in a separated PR though.

[DanHeidinga]

I'd prefer to keep that logic in isPackageExportedToModuleWithName() so that there's only once place to modify it.

[gacholio]

jenkins test sanity plinux jdk9

[JasonFengJ9]

isPackageExportedToModuleWithName invokes isPackageExportedToModuleHelper(currentThread, fromModule, getPackageDefinitionWithName(currentThread, fromModule, packageName, len, errCode), toModule, toUnnamed) in which getPackageDefinitionWithName might not be a cheap call for j9mem_allocate_memory, hashPackageTableAtWithUTF8Name, etc.

Agreed that more thinking is needed to avoid spreading out access checking code.