Eric Botcazou <ebotca...@adacore.com> writes:
>> gcc/ada/init.c (__gnat_install_handler) explicitly does not include
>> SA_SIGINFO in sa_flags, which means the handler only gets one arg, sig.
>> Still the installed handler (__gnat_error_handler) accesses args beyond
>> the first.
>
> Why would it get only one arg? The comment explicitly says that it gets
> three.
> Or is the prototype bogus in this case?
It gets three *if SA_SIGINFO is set in act.sa_flags*, which is is not.
>> There are two possible solutions:
>>
>> * Actually set SA_SIGINFO.
>>
>> * Punt and cast the second __gnat_error_handler `arg' to an int.
>> Running under gdb, it seems that three args are really passed.
>
> Why does it not work to just change act.sa_handler to act.sa_sigaction?
That's what I did in my last patch, but without SA_SIGINFO set. This
doesn't work since the additional args passed in the sa_handler case are
not in any prototype, to g++ rightly complains (and this is an
implementation detail I'd not rely upon if it can be avoided).
>> I prefer the first, since that's the clean solution. Unfortunately, my
>> question why the current code doesn't set SA_SIGINFO, yet cites a
>> considerable part of the man page about its effects, remained unanswered
>> when I submitted the patch.
>
> I'd go for the minimal change that works, including an ugly cast somewhere.
I'm just testing the SA_SIGINFO path, which seems the correct way if it
works.
Rainer
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Rainer Orth, Center for Biotechnology, Bielefeld University
