Don't partially set signal handlers

If some of the signal handlers are already set we can get into situation
where we can not clear our handlers. This can lead to infinite loops.

Author: stefan-il

IGC/AdaptorOCL/ocl_igc_interface/impl/igc_signal_guard.h

@@ -9,28 +9,23 @@ SPDX-License-Identifier: MIT
 #ifndef IGC_SIGNAL_GUARD_H
 #define IGC_SIGNAL_GUARD_H
 
-#include <setjmp.h>
-#include <signal.h>
+#include <csignal>
 
-namespace IGC {
-namespace detail {
+namespace IGC::detail {
 class SignalGuard {
 public:
   SignalGuard(int Signal, void (*Handler)(int, siginfo_t *, void *))
       : Signal(Signal) {
     sigaction(Signal, nullptr, &SAOld);
-    if (SAOld.sa_handler == SIG_DFL) {
-      struct sigaction SA;
-      sigemptyset(&SA.sa_mask);
-      SA.sa_sigaction = Handler;
-      SA.sa_flags = 0;
-      sigaction(Signal, &SA, nullptr);
-    }
+    struct sigaction SA{};
+    sigemptyset(&SA.sa_mask);
+    SA.sa_sigaction = Handler;
+    SA.sa_flags = 0;
+    sigaction(Signal, &SA, nullptr);
   }
 
   ~SignalGuard() {
-    if (SAOld.sa_handler == SIG_DFL)
-      sigaction(Signal, &SAOld, nullptr);
+    sigaction(Signal, &SAOld, nullptr);
   }
 
   SignalGuard(const SignalGuard &) = delete;
@@ -40,8 +35,7 @@ class SignalGuard {
   const int Signal;
   struct sigaction SAOld;
 }; // class SignalGuard
-} // namespace detail
-} // namespace IGC
+} // namespace IGC::detail
 
 #define SET_SIG_HANDLER(SIG)                                                   \
   ::IGC::detail::SignalGuard SG##SIG(SIG, signalHandler);