RFR [XXS] : JDK-8081616: build fixes for --disable-warnings-as-errors

[Bertrand Delsart]

On 02/06/2015 12:45, Magnus Ihse Bursie wrote:
> On 2015-06-02 12:35, Magnus Ihse Bursie wrote:
>> On 2015-06-02 12:27, David Holmes wrote:
>>> These should be removed instead.
>>>
>>> Okay but I don't think it reasonable to expect Bertrand to make such
>>> changes. In the interest of moving forward can we use his current
>>> patch and file a follow up bug to get this done properly by the build
>>> team?
>> It's not worth the trouble to put in bad code just to rip it out. I'll
>> have the patch done in five minutes, brb. :)
>
> Here's the webrev:
> http://cr.openjdk.java.net/~ihse/JDK-8081616-respect-disable-warnings-as-errors/webrev.01
>
>
> No top level changes are needed. I kept the disabling of
> unused-parameter in libsctp for pragmatic reasons. On my computer it
> compiled fine without it, but it requires more work to determine if it
> can be removed.

I was shooting for a simple fix, with no cleanup, to reduce regression 
risks (particularly since I'm not an expert on the new build system).

Your fix looks like a good cleanup and should be sufficient to solve my 
issue... but may have a small side effect.

In particular, If I understand correctly, the Werror in Lib-jdk.sctp.gmk 
was redundant. Hence, on ppc, we were by default compiling with Werror 
but without -Wno-unused-parameter. With your fix we will now be less 
strict on PPC, allowing unused parameters.

This may not be a big deal since AIX is filtered-out. This would apply 
only to open linux-ppc ports, if any. Hence, this is probably OK but 
I'll let you grab the CR and decide whether to push it as is or not.

Thanks,

Bertrand.

>
> /Magnus
>
>>
>> /Magnus
>>
>>>
>>> Thanks,
>>> David
>>> -----
>>>
>>>> I also checked for -Werror in the code, but could only find the already
>>>> discovered location in Lib-jdk.sctp.gmk. For that, I believe the proper
>>>> solution is:
>>>> diff --git a/make/lib/Lib-jdk.sctp.gmk b/make/lib/Lib-jdk.sctp.gmk
>>>> --- a/make/lib/Lib-jdk.sctp.gmk
>>>> +++ b/make/lib/Lib-jdk.sctp.gmk
>>>> @@ -30,12 +30,8 @@
>>>>   ifeq ($(OPENJDK_TARGET_OS_TYPE), unix)
>>>>
>>>>     ifeq (, $(filter $(OPENJDK_TARGET_OS), macosx aix))
>>>> -
>>>> -    # Suppress unused parameters required by exported JNI functions.
>>>> -    SCTP_WERROR := -Werror -Wno-error=unused-parameter
>>>> -    ifeq ($(OPENJDK_TARGET_CPU_ARCH), ppc)
>>>> -      SCTP_WERROR :=
>>>> -    endif
>>>> +    # DISABLED_WARNINGS_gcc := unusused-parameter needed to
>>>> +    # suppress unused parameters required by exported JNI functions.
>>>>
>>>>       $(eval $(call SetupNativeCompilation,BUILD_LIBSCTP, \
>>>>           LIBRARY := sctp, \
>>>> @@ -49,7 +45,7 @@
>>>>               $(LIBJAVA_HEADER_FLAGS) \
>>>>               -I$(SUPPORT_OUTPUTDIR)/headers/jdk.sctp \
>>>>               -I$(SUPPORT_OUTPUTDIR)/headers/java.base, \
>>>> -        CFLAGS_linux := $(SCTP_WERROR), \
>>>> +        DISABLED_WARNINGS_gcc := unusused-parameter, \
>>>>           MAPFILE :=
>>>> $(JDK_TOPDIR)/make/mapfiles/libsctp/mapfile-vers, \
>>>>           LDFLAGS := $(LDFLAGS_JDKLIB) \
>>>>               $(call SET_SHARED_LIBRARY_ORIGIN), \
>>>>
>>>>
>>>> However, as I said, it should probably be verified that it is correct
>>>> that the unused-parameter warning is still triggered.
>>>>
>>>> /Magnus
>>>>
>>>>
>>>>
>>>>>
>>>>> David
>>>>> -----
>>>>>
>>>>>
>>>>>
>>>>>> I can see that libsctp is a special case that hard-codes -Werror.
>>>>>> But in
>>>>>> this case we should remove the hard-coding and relying on the system
>>>>>> setting. This is probably a remnant from before the overall -Werror
>>>>>> usage, where the authors of a specific lib wanted to enforce a higher
>>>>>> standard. Also, it might be worth revisiting if
>>>>>> -Wno-error=unused-parameter is really needed. These things tend to
>>>>>> bit-rot.
>>>>>>
>>>>>> /Magnus
>>>>>>
>>>>>>>
>>>>>>> Best regards,
>>>>>>>
>>>>>>> Bertrand.
>>>>>>>
>>>>>>
>>>>
>>
>


-- 
Bertrand Delsart,                     Grenoble Engineering Center
Oracle,         180 av. de l'Europe,          ZIRST de Montbonnot
38330 Montbonnot Saint Martin,                             FRANCE
bertrand.delsart at oracle.com             Phone : +33 4 76 18 81 23

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