[fpc-pascal] ppc64le ABI problem

[tobiasgiesen at gmail.com]

Hello,

yes I will send you a minimal program to call XGetWindowProperty.

Cheers,
Tobias

----

On Tue, 27 Aug 2019 11:35:01 +0200
Pierre Muller <pierre at freepascal.org> wrote:

> Hi,
> 
>   the testsuite results show no difference,
> this probably means that we have no test that checks
> GCC compatibility for more than 8 parameters...
> 
>   Tobias, could you send us a small source that allows to check this?
> 
> Thanks in advance,
> 
> Pierre
> 
> 
> Le 26/08/2019 à 00:59, tobiasgiesen at gmail.com a écrit :
> > Hello,
> > 
> > while examining a crash when running Lazarus on ppc64le, I found the
> > following issue in function calls.
> > 
> > Calls to functions with more than eight parameters seem to be
> > implemented differently from how gcc does it in a C program.
> > 
> > gcc uses the memory location 96(r1) for the ninth parameter, but FPC
> > uses 112(r1).
> > 
> > Therefore, calls to XGetWindowProperty crash. This function has 12
> > parameters. gcc puts the four last ones into  96(r1), 104(r1), 112(r1), 120(r1),
> > and FPC into 112(r1), 120(r1), 128(r1), 136(r1).
> > 
> > What can be done about this?
> > 
> > I also noticed that the "file" command in Linux mentioned an additional
> > property of the linked C program I wrote for testing:
> > "for GNU/Linux 3.10.0"
> > 
> > The FPC program did not have this tag.
> > 
> > The complete "file" outputs are:
> > 
> > a.out: ELF 64-bit LSB shared object, 64-bit PowerPC or cisco 7500, version
> > 1 (SYSV), dynamically linked, interpreter /lib64/ld64.so.2,
> > BuildID[sha1]=6c5d2b5c7408e74eeda95fbf8d120fe8de0f2f30, for GNU/Linux
> > 3.10.0, with debug_info, not stripped
> > 
> > minimalxcrash: ELF 64-bit LSB executable, 64-bit PowerPC or cisco 7500,
> > version 1 (SYSV), dynamically linked, interpreter /lib64/ld64.so.2, with
> > debug_info, not stripped
> > 
> > Hoping my find will be useful,
> > Best wishes,
> > Tobias Giesen
> > 
> > _______________________________________________
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> > 
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Kind Regards,
Tobias Giesen

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