init.c (__gnat_error_handler): Cast reason to int.

	* init.c (__gnat_error_handler): Cast reason to int.
	(__gnat_install_handler): Explain sa_sigaction use.

From-SVN: r176870

1 files changed, 10 insertions, 2 deletions

diff --git a/gcc/ada/init.c b/gcc/ada/init.c
index b46cafd..52d7755 100644
--- a/gcc/ada/init.c
+++ b/gcc/ada/init.c
@@ -787,7 +787,11 @@ extern struct Exception_Data _abort_signal;
 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;