[fpc-pascal] ppc64le ABI problem

[Pierre Muller]

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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