Migrating to jni-rs 0.21 (fix #1)

catch_panic/Cargo.toml

@@ -24,6 +24,6 @@ jni = "0"
 catch_panic_macros = { version = "1.0.0", path = "../catch_panic_macros" }
 
 [dev-dependencies]
-jni = { version = "0", features = ["invocation"] }
+jni = { version = "0.21.1", features = ["invocation"] }
 catch_panic = { path = ".", features = ["internal-doctests"] }
 trybuild = "1.0.63"

catch_panic/src/handler.rs

@@ -26,7 +26,7 @@ where
 /// `#[catch_panic]`'s default panic handler. This
 /// will rethrow all caught panics as java `RuntimeException`s
 /// with the message passed to `panic!`.
-pub fn default_handler(env: JNIEnv, err: Box<dyn Any + Send + 'static>) {
+pub fn default_handler(mut env: JNIEnv, err: Box<dyn Any + Send + 'static>) {
     let msg = match err.downcast_ref::<&'static str>() {
         Some(s) => *s,
         None => match err.downcast_ref::<String>() {

catch_panic/src/lib.rs

@@ -40,8 +40,8 @@
 //! #
 //! #[no_mangle]
 //! #[catch_panic(default = "std::ptr::null_mut()")]
-//! pub extern "C" fn Java_com_example_Example_gimmeAnObject(env: JNIEnv) -> jobject {
-//!     env.alloc_object("java/lang/Object").unwrap().into_inner()
+//! pub extern "C" fn Java_com_example_Example_gimmeAnObject(mut env: JNIEnv) -> jobject {
+//!     env.alloc_object("java/lang/Object").unwrap().into_raw()
 //! }
 //!
 //! # catch_panic::test::check_callback(|env| Java_com_example_Example_gimmeAnObject(env), false);
@@ -59,7 +59,7 @@
 //! # use jni::JNIEnv;
 //! # use catch_panic::catch_panic;
 //! #
-//! pub fn enterprise_certified_handler(env: JNIEnv, err: Box<dyn Any + Send + 'static>) {
+//! pub fn enterprise_certified_handler(mut env: JNIEnv, err: Box<dyn Any + Send + 'static>) {
 //!     let msg = match err.downcast_ref::<&'static str>() {
 //!         Some(s) => *s,
 //!         None => match err.downcast_ref::<String>() {
@@ -88,7 +88,7 @@
 //! #
 //! #         env.define_class(
 //! #             "com/example/ExampleEnterpriseException",
-//! #             object_class_loader.try_into().unwrap(),
+//! #             &object_class_loader.try_into().unwrap(),
 //! #             &src,
 //! #         )
 //! #         .unwrap();
@@ -120,12 +120,17 @@ pub mod test {
 
     pub fn check_callback_with_setup<S, C, R>(setup: S, callback: C, should_throw: bool)
     where
-        S: FnOnce(JNIEnv),
+        S: FnOnce(&mut JNIEnv),
         C: Fn(JNIEnv) -> R,
     {
         let env = util::attach_current_thread();
-        setup(*env);
-        callback(*env);
+        unsafe {
+            // Safety: cloned env will be dropped before guard drop, and do not
+            // create local reference crossing local reference frame. 
+            let mut env = env.unsafe_clone();
+            setup(&mut env);
+            callback(env);
+        }
         assert_eq!(
             env.exception_check().expect("Couldn't check if there was an exception"),
             should_throw,

catch_panic/ui_tests/fail/no_jni_env.stderr

@@ -2,4 +2,4 @@ error: #[catch_panic] requires that this function has at least one argument of t
  --> ui_tests/fail/no_jni_env.rs:4:1
   |
 4 | fn no_jni_env() {
-  | ^^^^^^^^^^^^^^^
+  | ^^

catch_panic/ui_tests/fail/on_struct.stderr

@@ -2,4 +2,4 @@ error: #[catch_panic] can only be applied to functions
  --> ui_tests/fail/on_struct.rs:4:1
   |
 4 | pub struct PanicDonationBox;
-  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  | ^^^

catch_panic/ui_tests/fail/wrong_handler_type.stderr

@@ -1,17 +1,22 @@
 error[E0631]: type mismatch in function arguments
-  --> ui_tests/fail/wrong_handler_type.rs:9:25
-   |
-4  | pub fn trust_me(_env: JNIEnv, err: String) {
-   | ------------------------------------------ found signature of `for<'r> fn(JNIEnv<'r>, String) -> _`
+ --> ui_tests/fail/wrong_handler_type.rs:9:25
+  |
+4 | pub fn trust_me(_env: JNIEnv, err: String) {
+  | ------------------------------------------ found signature defined here
 ...
-9  | #[catch_panic(handler = "trust_me")]
-   | ------------------------^^^^^^^^^^--
-   | |                       |
-   | |                       expected signature of `for<'r> fn(JNIEnv<'r>, Box<(dyn Any + Send + 'static)>) -> _`
-   | required by a bound introduced by this call
-   |
+9 | #[catch_panic(handler = "trust_me")]
+  | ------------------------^^^^^^^^^^--
+  | |                       |
+  | |                       expected due to this
+  | required by a bound introduced by this call
+  |
+  = note: expected function signature `for<'a> fn(JNIEnv<'a>, Box<(dyn Any + Send + 'static)>) -> _`
+             found function signature `for<'a> fn(JNIEnv<'a>, String) -> _`
 note: required by a bound in `__catch_panic`
-  --> src/handler.rs
-   |
-   |     H: FnOnce(JNIEnv, Box<dyn Any + Send + 'static>),
-   |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `__catch_panic`
+ --> src/handler.rs
+  |
+  | pub fn __catch_panic<F, R, H>(env: JNIEnv, default: R, handler: H, f: F) -> R
+  |        ------------- required by a bound in this function
+...
+  |     H: FnOnce(JNIEnv, Box<dyn Any + Send + 'static>),
+  |        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `__catch_panic`

catch_panic_macros/src/lib.rs

@@ -103,7 +103,13 @@ pub fn catch_panic(attr: TokenStream, item: TokenStream) -> TokenStream {
     TokenStream::from(quote! {
         #(#attrs)*
         #vis #sig {
-            ::catch_panic::handler::__catch_panic(#first_arg_name, #default_value, #handler, move || {
+            // Safety: one JNIEnv goes to #handler, the other one goes to
+            // #block closure. __catch_panic() itself do not use JNIEnv so
+            // any local reference created with JNIEnv must be within #hander
+            // and/or #block, and these references are guaranteed to be
+            // discarded when #handler or #block exit.
+            let __handler_env = unsafe { #first_arg_name.unsafe_clone() };
+            ::catch_panic::handler::__catch_panic(__handler_env, #default_value, #handler, move || {
                 #block
             })
         }