Re: [PATCH 1/2][ARM] PR/65956 AAPCS update for alignment attribute

[Alan Lawrence <alan.lawrence@arm.com>]

On 04/11/15 13:13, Jakub Jelinek wrote:
> On Mon, Jul 06, 2015 at 05:38:35PM +0100, Alan Lawrence wrote:
>> Trying to push these now (svn!), patch 2 is going first.
>>
>> I realize my second iteration of patch 1/2, dropped the testcases from the
>> first version. Okay to include those as per
>> https://gcc.gnu.org/ml/gcc-patches/2015-07/msg00215.html ?
>
> FYI, it seems that (most likely) the PR65956 changes on gcc-5-branch
> broke libgnat ABI compatibility on arm - it seems that getsubs.adb
> from macrosub proglet (and others) are during make check compiled/linked
> with system gnatmake/gcc, but the program is run at runtime
> against the new libgnat-5.so.  If I run it manually against
> system libgnat, it works, otherwise it hangs, when Fill_Table from
> getsubs.adb calls Get_Line, and indeed it looks like the argument passing
> for Get_Line changed and on the callee side it thinks Item (which is 400
> chars string) has random (and in the hanging case negative) number of chars
> in it.
>
> 	Jakub
>

Sorry Jakub, can you clarify please, how to reproduce this failure? I've just 
bootstrapped gcc-5-branch with ada and run the Ada testsuite, which has build me 
gcc/ada/rts/libgnat{.a,.so,-5.so}, and I see all tests passing. (Same with 
--disable-bootstrap FWIW.)

It seems plausible that Ada would be the language affected by the ABI change, 
obviously it would be somewhat ironic that we broke intercompatibility with 
gcc's own libgnat but not against libgnat prior to the change...

Thanks,
Alan