Eric Botcazou <ebotca...@adacore.com> writes:
>> 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).
>
> OK, I see, so there is a single prototype for the 2 variants with 3 args.
Right. Even if I can cope with that, I haven't been able to extract all
the required info (pc, gregs, fpregs) from ucontext_t/mcontext_t with
SA_SIGINFO set. Besides, it doesn't seem possible to distinguish
between the two cases (sa_handler/sa_sigaction). Therefore I went back
for the following hack, adding comments to explain why it is necessary.
Bootstrapped without regressions on mips-sgi-irix6.5, all signal
handling failures introduced by my previous patch are gone again.
Ok for mainline?
Rainer
2011-07-26 Rainer Orth <r...@cebitec.uni-bielefeld.de>
* init.c (__gnat_error_handler): Cast reason to int.
(__gnat_install_handler): Explain sa_sigaction use.
diff --git a/gcc/ada/init.c b/gcc/ada/init.c
--- a/gcc/ada/init.c
+++ b/gcc/ada/init.c
@@ -787,7 +787,11 @@ extern struct Exception_Data _abort_sign
static void
__gnat_error_handler (int sig, siginfo_t *reason, void *uc ATTRIBUTE_UNUSED)
{
- int code = reason == NULL ? 0 : reason->si_code;
+ /* This handler is installed with SA_SIGINFO cleared, but there's no
+ prototype for the resulting alternative three-argument form, so we
+ have to hack around this by casting reason to the int actually
+ passed. */
+ int code = (int) reason;
struct Exception_Data *exception;
const char *msg;
@@ -872,7 +876,11 @@ __gnat_install_handler (void)
/* Setup signal handler to map synchronous signals to appropriate
exceptions. Make sure that the handler isn't interrupted by another
- signal that might cause a scheduling event! */
+ signal that might cause a scheduling event!
+
+ The handler is installed with SA_SIGINFO cleared, but there's no
+ C++ prototype for the three-argument form, so fake it by using
+ sa_sigaction and casting the arguments instead. */
act.sa_sigaction = __gnat_error_handler;
act.sa_flags = SA_NODEFER + SA_RESTART;
--
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University
