Annotation processors and the --processor-module-path

[Jan Lahoda]

On 21.11.2016 11:03, Alan Bateman wrote:
> On 21/11/2016 09:46, Eirik Bjørsnøs wrote:
>
>> Alan,
>>
>> | $ javac --help
>> | -processor <class1>[,<class2>,<class3>...]
>> |        Names of the annotation processors to run; bypasses default
>> discovery process
>>
>> Why does the "default discovery process" work  with --classpath, but not
>> with --processor-module-path?
>>
>> Is it simply an omission, or is this by design?
>>
> If you have `provides javax.annotation.processing.Processor with ...` in
> your module declaration then it should find it. I just checked this
> locally and it works as expected. One of your mails said this wasn't
> working for you, not immediately obvious why from the mails. So if you
> aren't using `provides` then my understanding is that the processor
> needs to be specified via -processor but I don't think there is support
> there for allowing -processor to specify the processor module, hence not
> clear how it could be resolved.

Currently, AFAIK, the processors on module path need to be registered in 
the ServiceLoader. For --processor-module-path, "-processor" can be used 
to select processors out of those registered in the ServiceLoader. If 
--processor-module-path is used and there is no "-processor", all 
processors registered in ServiceLoader are considered, AFAIK. Please 
note that (as before) the processors are only run if their 
SupportedAnnotationTypes match, etc.

I tried a simple example as well, and with the proper "provides" the 
annotation processor was run. Is there a testcase we could try?

Jan

>
> -Alan