[OpenJDK 2D-Dev] [PATCH] Build fails to compile jchuff.c

[Phil Race]

Try again with build-dev cc'd ..

-phil.

On 01/18/2018 11:14 AM, Phil Race wrote:
> I agree with what Erik said on build-dev that being specific about the 
> tool chain
> and the reason are worthwhile and important. We've done that in 
> similar cases.
>
> Also these review threads usually should have a subject like
> RFR: <BUG ID>: <Bug Synopsis>
>
> which means you first need a bug id .. the patch can't be pushed 
> without one anyway.
>
> Then the patch should be an in-line diff or a webrev hosted on 
> cr.openjdk.java.net.
>
> I think in-line would be OK for this small change.
>
> -phil.
>
> On 01/17/2018 09:30 AM, Adam Farley8 wrote:
>> Hi All,
>>
>> Under these circumstances, jchuff.c will not compile:
>>
>> Platform: zLinux (s390x)
>> Release: JDK9 (may affect other JDKs).
>> GCC Version: 4.8.5
>> Notes: --disable-warnings-as-errors suppresses this error.
>>
>> The error is:
>>
>> /home/adamfarl/hotspot/jdk9/jdk/src/java.desktop/share/native/libjavajpeg/jchuff.c:
>> In function 'jGenOptTbl':
>> /home/adamfarl/hotspot/jdk9/jdk/src/java.desktop/share/native/libjavajpeg/jchuff.c:808:18:
>> error: array subscript is below array bounds [-Werror=array-bounds]
>>       while (bits[j] == 0)
>>                  ^
>>
>> This is a continuation of a conversation in the build-dev mailing 
>> list, if anyone wants to
>> check the history.
>>
>> The short version is that, while you *can* suppress the problem by 
>> adding
>> --disable-warnings-as-errors to your configure step, I posit that a 
>> builder shouldn't
>> have to.
>>
>> Various solutions were debated. One involves changing 
>> Awt2dLibraries.gmk.
>>
>> Basically you change line 494 to this:
>>
>>     DISABLED_WARNINGS_gcc := clobbered array-bounds, \
>>
>> I'm running a build now to check that works, but basically we should 
>> end up with a
>> -Wno-array-bounds on the gcc compile command for jchuff.c, thereby 
>> ignoring the warning.
>>
>> A smarter variant involves checking for that specific version of the 
>> gcc, but that seems
>> wordy to me for this problem. Keeping it simple. :)
>>
>> Thoughts?
>>
>> Best Regards
>>
>> Adam Farley
>>
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>