Catch when the debug callback panicks

vulkano/src/instance/debug.rs

@@ -33,6 +33,7 @@ use std::ffi::CStr;
 use std::fmt;
 use std::mem;
 use std::os::raw::{c_void, c_char};
+use std::panic;
 use std::ptr;
 use std::sync::Arc;
 
@@ -55,9 +56,11 @@ pub struct DebugCallback {
 
 impl DebugCallback {
     /// Initializes a debug callback.
+    ///
+    /// Panicks generated by calling `user_callback` are ignored.
     pub fn new<F>(instance: &Arc<Instance>, messages: MessageTypes, user_callback: F)
                   -> Result<DebugCallback, DebugCallbackCreationError>
-        where F: Fn(&Message) + 'static
+        where F: Fn(&Message) + 'static + panic::RefUnwindSafe
     {
         if !instance.loaded_extensions().ext_debug_report {
             return Err(DebugCallbackCreationError::MissingExtension);
@@ -72,8 +75,6 @@ impl DebugCallback {
                                     _: i32, layer_prefix: *const c_char,
                                     description: *const c_char, user_data: *mut c_void) -> u32
         {
-            // FIXME: use panic::recover
-
             unsafe {
                 let user_callback = user_data as *mut Box<Fn()> as *const _;
                 let user_callback: &Box<Fn(&Message)> = &*user_callback;
@@ -97,7 +98,11 @@ impl DebugCallback {
                     description: description,
                 };
 
-                user_callback(&message);
+                // Since we box the closure, the type system doesn't detect that the `UnwindSafe`
+                // bound is enforced. Therefore we enforce it manually.
+                let _ = panic::catch_unwind(panic::AssertUnwindSafe(move || {
+                    user_callback(&message);
+                }));
 
                 vk::FALSE
             }
@@ -143,7 +148,7 @@ impl DebugCallback {
     #[inline]
     pub fn errors_and_warnings<F>(instance: &Arc<Instance>, user_callback: F)
                                   -> Result<DebugCallback, DebugCallbackCreationError>
-        where F: Fn(&Message) + 'static
+        where F: Fn(&Message) + 'static + panic::RefUnwindSafe
     {
         DebugCallback::new(instance, MessageTypes::errors_and_warnings(), user_callback)
     }