Abort if C++ tries to swallow a Rust panic

4 files changed, 9 insertions, 0 deletions

diff --git a/src/libpanic_unwind/emcc.rs b/src/libpanic_unwind/emcc.rs
index fbadf4ac6a0..268bafd2409 100644
--- a/src/libpanic_unwind/emcc.rs
+++ b/src/libpanic_unwind/emcc.rs
@@ -80,6 +80,7 @@ pub unsafe fn panic(data: Box<dyn Any + Send>) -> u32 {
     extern "C" fn exception_cleanup(ptr: *mut libc::c_void) {
         unsafe {
             ptr::drop_in_place(ptr as *mut Exception);
+            super::__rust_drop_panic();
         }
     }
 }
diff --git a/src/libpanic_unwind/gcc.rs b/src/libpanic_unwind/gcc.rs
index 6bec2686533..6e04317d491 100644
--- a/src/libpanic_unwind/gcc.rs
+++ b/src/libpanic_unwind/gcc.rs
@@ -78,6 +78,7 @@ pub unsafe fn panic(data: Box<dyn Any + Send>) -> u32 {
     ) {
         unsafe {
             let _: Box<Exception> = Box::from_raw(exception as *mut Exception);
+            super::__rust_drop_panic();
         }
     }
 }
diff --git a/src/libpanic_unwind/lib.rs b/src/libpanic_unwind/lib.rs
index 9451eefb9a5..6383ae39fb6 100644
--- a/src/libpanic_unwind/lib.rs
+++ b/src/libpanic_unwind/lib.rs
@@ -61,6 +61,12 @@ cfg_if::cfg_if! {
     }
 }
 
+extern "C" {
+    /// Handler in libstd called when a panic object is dropped outside of
+    /// `catch_unwind`.
+    fn __rust_drop_panic() -> !;
+}
+
 mod dwarf;
 
 // Entry point for catching an exception, implemented using the `try` intrinsic
diff --git a/src/libpanic_unwind/seh.rs b/src/libpanic_unwind/seh.rs
index f1d0080472a..d9dca2c0f4f 100644
--- a/src/libpanic_unwind/seh.rs
+++ b/src/libpanic_unwind/seh.rs
@@ -229,6 +229,7 @@ macro_rules! define_cleanup {
         unsafe extern $abi fn exception_cleanup(e: *mut [u64; 2]) {
             if (*e)[0] != 0 {
                 cleanup(*e);
+                super::__rust_drop_panic();
             }
         }
         #[unwind(allowed)]