Improve panic messages in init/terminate callbacks

Co-authored-by: nyanpasu64 <[email protected]>

Author: Bromeon

gdnative-core/src/init/macros.rs

@@ -56,13 +56,9 @@ macro_rules! godot_nativescript_init {
                 }
             }
 
-            let __result = ::std::panic::catch_unwind(|| {
+            $crate::private::report_panics("nativescript_init", || {
                 $callback($crate::init::InitHandle::new(handle));
             });
-
-            if __result.is_err() {
-                $crate::godot_error!("gdnative-core: nativescript_init callback panicked");
-            }
         }
     };
 }
@@ -104,13 +100,10 @@ macro_rules! godot_gdnative_init {
                 return;
             }
 
-            let __result = ::std::panic::catch_unwind(|| {
-                let callback_options = $crate::init::InitializeInfo::new(options);
-                $callback(&callback_options)
+            $crate::private::report_panics("gdnative_init", || {
+                let init_info = $crate::init::InitializeInfo::new(options);
+                $callback(&init_info)
             });
-            if __result.is_err() {
-                $crate::godot_error!("gdnative-core: gdnative_init callback panicked");
-            }
         }
     };
 }
@@ -152,13 +145,10 @@ macro_rules! godot_gdnative_terminate {
                 return;
             }
 
-            let __result = ::std::panic::catch_unwind(|| {
+            $crate::private::report_panics("gdnative_terminate", || {
                 let term_info = $crate::init::TerminateInfo::new(options);
                 $callback(&term_info)
             });
-            if __result.is_err() {
-                $crate::godot_error!("gdnative-core: nativescript_init callback panicked");
-            }
 
             $crate::private::cleanup_internal_state();
         }

gdnative-core/src/private.rs

@@ -1,4 +1,5 @@
 use std::ffi::CString;
+use std::panic::{catch_unwind, UnwindSafe};
 
 use crate::sys;
 
@@ -181,6 +182,26 @@ unsafe fn report_init_error(
     }
 }
 
+#[inline]
+pub fn report_panics(context: &str, callback: impl FnOnce() + UnwindSafe) {
+    let __result = catch_unwind(callback);
+
+    if let Err(e) = __result {
+        godot_error!("gdnative-core: {} callback panicked", context);
+        print_error(e);
+    }
+}
+
+fn print_error(err: Box<dyn std::any::Any + Send>) {
+    if let Some(s) = err.downcast_ref::<String>() {
+        godot_error!("Panic message: {}", s);
+    } else if let Some(s) = err.downcast_ref::<&'static str>() {
+        godot_error!("Panic message: {}", s);
+    } else {
+        godot_error!("Panic message unknown, type {:?}", err.type_id());
+    }
+}
+
 pub mod godot_object {
     pub trait Sealed {}
 }