RFR: JDK-8167479: arm 32/64 slowdebug fails to build on unpack200

[Magnus Ihse Bursie]

On 2016-10-12 04:38, David Holmes wrote:
> On 11/10/2016 7:41 PM, Erik Joelsson wrote:
>> Hello,
>>
>> After the cleanup of C++ linking with the GCC toolchain. We missed
>> updating one instance with the correct TOOLCHAIN configuration. This
>> leads to build failures for arm ports with slowdebug. I have no idea why
>> it only happens there, but correcting the TOOLCHAIN configuration (so
>> that g++ is used to link instead of gcc) makes it build again.
>
> Unexplained errors raise alarm bells for me. This particular reference 
> relates to C++ exception handling which raises questions:
>
> - why only on this platform?
> - why only in slowdebug?
> - why only in this code? (which seems unrelated to exceptions)
>
> I agree the fix is to use g++ instead of gcc for linking, assuming the 
> exception related code should actually be there.
The alarm bells ringed for me too. :-) I actually started debugging this 
one, but Erik beat me to it. :) I did however conclude that this error 
occured due to static linking (without it, everything went fine) and if 
I explicitely specified -lstdc++ as well, I got a more informative 
error, telling me that the static version of libgcc was not found. I 
didn't go further, since Erik found the (correct) solution, but I assume 
that the devkit we use to build for the arm platforms are missing some 
bits, which was only needed for slowdebug builds.

/Magnus

>
> Thanks,
> David
>
>> The build error looks like this:
>>
>> /localhome/hg/jdk9-dev-CDR/build/linux-arm64-slowdebug/support/native/jdk.pack200/unpackexe/bands.o:(.data.DW.ref.__gxx_personality_v0[DW.ref.__gxx_personality_v0]+0x0): 
>>
>> undefined reference to `__gxx_personality_v0'
>> collect2: error: ld returned 1 exit status
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8167479
>>
>> Webrev: http://cr.openjdk.java.net/~erikj/8167479/webrev.01/
>>
>> /Erik
>>