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

[David Holmes]

On 12/10/2016 7:04 PM, Magnus Ihse Bursie wrote:
> 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.

Still too vague for me. What is special about this code?

Thanks,
David

> /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
>>>
>