[wpilibc] Add C++ Notifier error handling, update java notifier error message (#4795)

wpilibc/src/main/native/cpp/Notifier.cpp

@@ -7,6 +7,7 @@
 #include <utility>
 
 #include <fmt/format.h>
+#include <hal/DriverStation.h>
 #include <hal/FRCUsageReporting.h>
 #include <hal/Notifier.h>
 #include <hal/Threads.h>
@@ -95,7 +96,21 @@ Notifier::Notifier(int priority, std::function<void()> handler) {
 
       // call callback
       if (handler) {
-        handler();
+        try {
+          handler();
+        } catch (const frc::RuntimeError& e) {
+          e.Report();
+          FRC_ReportError(
+              err::Error,
+              "Error in Notifier thread."
+              "  The above stacktrace can help determine where the error "
+              "occurred.\n"
+              "  See https://wpilib.org/stacktrace for more information.\n");
+          throw;
+        } catch (const std::exception& e) {
+          HAL_SendError(1, err::Error, 0, e.what(), "", "", 1);
+          throw;
+        }
       }
     }
   });

wpilibj/src/main/java/edu/wpi/first/wpilibj/Notifier.java

@@ -128,10 +128,12 @@ public class Notifier implements AutoCloseable {
             error = cause;
           }
           DriverStation.reportError(
-              "Unhandled exception: " + error.toString(), error.getStackTrace());
+              "Unhandled exception in Notifier thread: " + error.toString(), error.getStackTrace());
           DriverStation.reportError(
-              "The loopFunc() method (or methods called by it) should have handled "
-                  + "the exception above.",
+              "The Runnable for this Notifier (or methods called by it) should have handled "
+                  + "the exception above.\n"
+                  + "  The above stacktrace can help determine where the error occurred.\n"
+                  + "  See https://wpilib.org/stacktrace for more information.",
               false);
         });
     m_thread.start();