RFR: 8292275: javac does not emit SYNTHETIC and MANDATED flags for parameters by default

[Hannes Greule]

On Fri, 12 Aug 2022 22:35:38 GMT, Joe Darcy <darcy at openjdk.org> wrote:

>> With this change, javac emits the MethodParameters attribute in cases where the JLS requires the information about synthetic and mandated parameters to be stored (see issue).
>> Parameter names are *not* emitted unless the `-parameter` flag is set.
>> 
>> The relevant changes are in `ClassWriter`, where we go through the params to see if we need the attribute if the `-parameter` flag is not set (if it is set, both names and flags will be emitted).
>> For records, the mandated flag wasn't set at all, this is solved by the one line fix in `JavacParser`.
>> 
>> The changes to `CreateSymbols` and `ClassReader` are needed as they weren't able to deal with missing names in the attribute.
>> I also had to update some tests as they got a new constant pool entry.
>> 
>> Only the mandated flag is covered by tests at the moment, as the occurrences are well-specified in the JLS.
>> Please let me know if you want tests for specific appearances of synthetic parameters.
>
> test/langtools/tools/javac/RequiredParameterFlags/ImplicitParameters.java line 52:
> 
>> 50: import toolbox.ToolBox;
>> 51: 
>> 52: public class ImplicitParameters extends TestRunner {
> 
> In addition to this test, an annotation processing-based test could also be attempted here.

Could you elaborate on that? Should I add a processor to the JavacTask in this test or write a separate one? (Maybe there is a similar test I can use as reference?)
Thank you.

-------------

PR: https://git.openjdk.org/jdk/pull/9862