Re: Trying to build GNUstep from git repo and clang-9 on Raspbian Buster (10.4)

[David Chisnall]

On 18 Jun 2020, at 11:05, Johannes Brakensiek <johannes@brakensiek.info> wrote:
> 
> Thank you for your reply, David.
> 
> On 18 Jun 2020, at 10:46, David Chisnall wrote:
> 
>>> If you want to build libobjc2 on armhf you will have to use the older 
>>> version 1.9 of libobjc (which does not require clang >= 8, but works with 
>>> older versions of clang as well).
> 
>> The v2 and v1 ABIs do not use different assembly fast paths.
> 
> This is always a little bit confusing to me. Version 2.0 of libobjc2 supports 
> v2 and v1 ABI, ok. But compiling only worked using the version 1.9 of 
> libobjc2 (meaning the git tag/version, not the ABI version). Does that sound 
> correct to you?

No, that’s very confusing.  Please file bug reports.  The trunk version should 
build on ARM and I have not seen any bug reports about it other than a brief 
report when we fixed some EH things and didn’t update the ARM versions.

>>> Also, it would be very nice if anybody would like to do the missing 
>>> libobjc2 assembler implementation for armhf. I think this is a common use 
>>> case as long as the default arch for Raspbian is 32 bit. Even though this 
>>> arch will be running out of support at some time in the future, of course.
>> 
>> 
>> I did.  Five years ago.  Note that there was a bug until 15 months ago where 
>> the unwind info was not correctly set, so throwing an exception out of 
>> +initialize would potentially corrupt some floating point state.
> 
> That’s very good to read, thank you! Probably I read some outdated 
> documentation or was just using the 1.9 tag because Raspbian only had clang 7 
> available then. I will try again with 2.0 and clang 8 and report if I ran 
> into the same issue as Patrick.

Thanks,

David