feature: add Exception Handler support for unix

REF: https://github.com/o3de/o3de/issues/5886

Signed-off-by: Michael Pollind <mpollind@gmail.com>

Code/Framework/AzCore/Platform/Common/UnixLike/AzCore/Debug/Trace_UnixLike.cpp

@@ -6,15 +6,26 @@
  *
  */
 
+#include <AzCore/Debug/TraceMessageBus.h>
 #include <AzCore/IO/SystemFile.h>
 #include <AzCore/std/string/string_view.h>
 
 #include <ctype.h>
+#include <execinfo.h>
 #include <signal.h>
 #include <unistd.h>
 
-namespace AZ::Debug::Platform
+namespace AZ::Debug
 {
+#if defined(AZ_ENABLE_DEBUG_TOOLS)
+    void ExceptionHandler(int signal);
+#endif
+
+    constexpr int MaxMessageLength = 4096;
+    constexpr int MaxStackLines = 100;
+
+    namespace Platform
+    {
 #if defined(AZ_ENABLE_DEBUG_TOOLS)
         bool performDebuggerDetection()
         {
@@ -63,8 +74,25 @@ namespace AZ::Debug::Platform
             return false;
         }
 
-    void HandleExceptions(bool)
-    {}
+        void SignalHandler(int handler)
+        {
+        }
+
+        void HandleExceptions(bool isEnabled)
+        {
+            if (isEnabled)
+            {
+                signal(SIGSEGV, ExceptionHandler);
+                signal(SIGTRAP, ExceptionHandler);
+                signal(SIGILL, ExceptionHandler);
+            }
+            else
+            {
+                signal(SIGSEGV, SIG_DFL);
+                signal(SIGTRAP, SIG_DFL);
+                signal(SIGILL, SIG_DFL);
+            }
+        }
 
         void DebugBreak()
         {
@@ -76,4 +104,31 @@ namespace AZ::Debug::Platform
         {
             _exit(exitCode);
         }
-} // namespace AZ::Debug::Platform
+    } // namespace Platform
+
+#if defined(AZ_ENABLE_DEBUG_TOOLS)
+    void ExceptionHandler(int signal)
+    {
+        char message[MaxMessageLength];
+        Debug::Trace::Instance().Output(nullptr, "==================================================================\n");
+        azsnprintf(message, MaxMessageLength, "Error: signal %s: \n", strsignal(signal));
+        Debug::Trace::Instance().Output(nullptr, message);
+
+        void* buffers[MaxStackLines];
+        int numberBacktraceStrings = backtrace(buffers, MaxStackLines);
+        char** backtraceResults = backtrace_symbols(buffers, numberBacktraceStrings);
+        if (backtraceResults == nullptr)
+        {
+            Debug::Trace::Instance().Output(nullptr, "==================================================================\n");
+            return;
+        }
+        for (int j = 0; j < numberBacktraceStrings; j++)
+        {
+            Debug::Trace::Instance().Output(nullptr, backtraceResults[j]);
+        }
+
+        Debug::Trace::Instance().Output(nullptr, "==================================================================\n");
+    }
+#endif
+
+} // namespace AZ::Debug

Code/Legacy/CrySystem/SystemInit.cpp

@@ -115,43 +115,6 @@ extern LONG WINAPI CryEngineExceptionFilterWER(struct _EXCEPTION_POINTERS* pExce
 #include AZ_RESTRICTED_FILE(SystemInit_cpp)
 #endif
 
-#if AZ_TRAIT_USE_CRY_SIGNAL_HANDLER
-
-#include <execinfo.h>
-#include <signal.h>
-void CryEngineSignalHandler(int signal)
-{
-    char resolvedPath[_MAX_PATH];
-
-    // it is assumed that @log@ points at the appropriate place (so for apple, to the user profile dir)
-    if (AZ::IO::FileIOBase::GetDirectInstance()->ResolvePath("@log@/crash.log", resolvedPath, _MAX_PATH))
-    {
-        fprintf(stderr, "Crash Signal Handler - logged to %s\n", resolvedPath);
-        FILE* file = fopen(resolvedPath, "a");
-        if (file)
-        {
-            char sTime[128];
-            time_t ltime;
-            time(&ltime);
-            struct tm* today = localtime(&ltime);
-            strftime(sTime, 40, "<%Y-%m-%d %H:%M:%S> ", today);
-            fprintf(file, "%s: Error: signal %s:\n", sTime, strsignal(signal));
-            fflush(file);
-            void* array[100];
-            int s = backtrace(array, 100);
-            backtrace_symbols_fd(array, s, fileno(file));
-            fclose(file);
-            CryLogAlways("Successfully recorded crash file:  '%s'", resolvedPath);
-            abort();
-        }
-    }
-
-    CryLogAlways("Could not record crash file...");
-    abort();
-}
-
-#endif // AZ_TRAIT_USE_CRY_SIGNAL_HANDLER
-
 //////////////////////////////////////////////////////////////////////////
 #define DEFAULT_LOG_FILENAME "@log@/Log.txt"
 
@@ -697,11 +660,6 @@ public:
 /////////////////////////////////////////////////////////////////////////////////
 bool CSystem::Init(const SSystemInitParams& startupParams)
 {
-#if AZ_TRAIT_USE_CRY_SIGNAL_HANDLER
-    signal(SIGSEGV, CryEngineSignalHandler);
-    signal(SIGTRAP, CryEngineSignalHandler);
-    signal(SIGILL, CryEngineSignalHandler);
-#endif // AZ_TRAIT_USE_CRY_SIGNAL_HANDLER
 
     // Temporary Fix for an issue accessing gEnv from this object instance. The gEnv is not resolving to the
     // global gEnv, instead its resolving an some uninitialized gEnv elsewhere (NULL). Since gEnv is