Builds fail due to use of preview features & removed arguments

[Ty Young]

On 12/19/19 5:30 PM, David Holmes wrote:
> Hi Ty,
>
> On 20/12/2019 9:23 am, Ty Young wrote:
>> Hi,
>>
>>
>> As of the merging of Records into JDK proper, source code compiling 
>> fails using a standard command line of:
>>
>>
>> bash configure --disable-warnings-as-errors
>
> I would have expected that to ensure the warnings were NOT treated as 
> an error. Is there some build system bug here? Or is there some 
> double-negative at play ??


spec.gmk has this:


# A global flag (true or false) determining if native warnings are 
considered errors.
WARNINGS_AS_ERRORS := false


...implying that it only affects native warnings. The argument naming 
itself doesn't really suggest that though...


>
>>
>> which fails with:
>>
>>
>> /home/ty/Downloads/jdk-master/src/java.compiler/share/classes/javax/lang/model/util/AbstractElementVisitor14.java:30: 
>> warning: [preview] RecordComponentElement is an API that is part of a 
>> preview feature
>> import javax.lang.model.element.RecordComponentElement;
>>                                 ^
>> /home/ty/Downloads/jdk-master/src/java.compiler/share/classes/javax/lang/model/util/SimpleElementVisitor14.java:30: 
>> warning: [preview] RecordComponentElement is an API that is part of a 
>> preview feature
>> import javax.lang.model.element.RecordComponentElement;
>>                                 ^
>> error: warnings found and -Werror specified
>
> I think this is more an issue for the language and compiler folk on 
> compiler-dev. I'm not clear on all the rules around use of preview 
> features but it seems to me that if we are using them internally and 
> that generates warnings then we should be suppressing those warnings 
> (@supressedWarning) at those call sites. Though I don't know whether 
> you can suppress a warning for an import statement??
>
> David
> -----


Sending this to them.


>
>>
>> ...which was not the case in 13. I'm assuming this is happening now 
>> because JDK source code actually utilizes the feature preview where 
>> as with other preview features before simply existed but weren't used 
>> in source.
>>
>>
>> I've been told by a JDK developer from the Project Panama mailing 
>> list that it *does* compile for them, but I'm not aware of the 
>> command line arguments that JDK developers use. Is this documented 
>> somewhere? Should it be failing by default like this?
>>
>>
>> Additionally, the argument --with-libclang-include-aux seems to have 
>> been deprecated in 14. This, as was told to me by a Panama JDK 
>> developer, is needed to specify clang headers for custom source 
>> builds. What is the correct way to specify those now in 14?
>>