binder: add async Rust support

Test: add and run integration tests
Change-Id: I7671eeb7dfe4cc45efd57756753b361440529a3c
diff --git a/libs/binder/rust/src/binder.rs b/libs/binder/rust/src/binder.rs
index cc5dd06..4e048d7 100644
--- a/libs/binder/rust/src/binder.rs
+++ b/libs/binder/rust/src/binder.rs
@@ -713,12 +713,14 @@
         $interface:path[$descriptor:expr] {
             native: $native:ident($on_transact:path),
             proxy: $proxy:ident,
+            $(async: $async_interface:ident,)?
         }
     } => {
         $crate::declare_binder_interface! {
             $interface[$descriptor] {
                 native: $native($on_transact),
                 proxy: $proxy {},
+                $(async: $async_interface,)?
                 stability: $crate::Stability::default(),
             }
         }
@@ -728,6 +730,7 @@
         $interface:path[$descriptor:expr] {
             native: $native:ident($on_transact:path),
             proxy: $proxy:ident,
+            $(async: $async_interface:ident,)?
             stability: $stability:expr,
         }
     } => {
@@ -735,6 +738,7 @@
             $interface[$descriptor] {
                 native: $native($on_transact),
                 proxy: $proxy {},
+                $(async: $async_interface,)?
                 stability: $stability,
             }
         }
@@ -746,6 +750,7 @@
             proxy: $proxy:ident {
                 $($fname:ident: $fty:ty = $finit:expr),*
             },
+            $(async: $async_interface:ident,)?
         }
     } => {
         $crate::declare_binder_interface! {
@@ -754,6 +759,7 @@
                 proxy: $proxy {
                     $($fname: $fty = $finit),*
                 },
+                $(async: $async_interface,)?
                 stability: $crate::Stability::default(),
             }
         }
@@ -765,6 +771,7 @@
             proxy: $proxy:ident {
                 $($fname:ident: $fty:ty = $finit:expr),*
             },
+            $(async: $async_interface:ident,)?
             stability: $stability:expr,
         }
     } => {
@@ -776,6 +783,7 @@
                 proxy: $proxy {
                     $($fname: $fty = $finit),*
                 },
+                $(async: $async_interface,)?
                 stability: $stability,
             }
         }
@@ -791,6 +799,8 @@
                 $($fname:ident: $fty:ty = $finit:expr),*
             },
 
+            $( async: $async_interface:ident, )?
+
             stability: $stability:expr,
         }
     } => {
@@ -924,7 +934,7 @@
             }
         }
 
-        impl std::fmt::Debug for dyn $interface {
+        impl std::fmt::Debug for dyn $interface + '_ {
             fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
                 f.pad(stringify!($interface))
             }
@@ -938,6 +948,73 @@
                     .expect(concat!("Error cloning interface ", stringify!($interface)))
             }
         }
+
+        $(
+        // Async interface trait implementations.
+        impl<P: $crate::BinderAsyncPool> $crate::FromIBinder for dyn $async_interface<P> {
+            fn try_from(mut ibinder: $crate::SpIBinder) -> $crate::Result<$crate::Strong<dyn $async_interface<P>>> {
+                use $crate::AssociateClass;
+
+                let existing_class = ibinder.get_class();
+                if let Some(class) = existing_class {
+                    if class != <$native as $crate::Remotable>::get_class() &&
+                        class.get_descriptor() == <$native as $crate::Remotable>::get_descriptor()
+                    {
+                        // The binder object's descriptor string matches what we
+                        // expect. We still need to treat this local or already
+                        // associated object as remote, because we can't cast it
+                        // into a Rust service object without a matching class
+                        // pointer.
+                        return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
+                    }
+                }
+
+                if ibinder.associate_class(<$native as $crate::Remotable>::get_class()) {
+                    let service: $crate::Result<$crate::Binder<$native>> =
+                        std::convert::TryFrom::try_from(ibinder.clone());
+                    if let Ok(service) = service {
+                        // We were able to associate with our expected class and
+                        // the service is local.
+                        todo!()
+                        //return Ok($crate::Strong::new(Box::new(service)));
+                    } else {
+                        // Service is remote
+                        return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
+                    }
+                }
+
+                Err($crate::StatusCode::BAD_TYPE.into())
+            }
+        }
+
+        impl<P: $crate::BinderAsyncPool> $crate::parcel::Serialize for dyn $async_interface<P> + '_ {
+            fn serialize(&self, parcel: &mut $crate::parcel::Parcel) -> $crate::Result<()> {
+                let binder = $crate::Interface::as_binder(self);
+                parcel.write(&binder)
+            }
+        }
+
+        impl<P: $crate::BinderAsyncPool> $crate::parcel::SerializeOption for dyn $async_interface<P> + '_ {
+            fn serialize_option(this: Option<&Self>, parcel: &mut $crate::parcel::Parcel) -> $crate::Result<()> {
+                parcel.write(&this.map($crate::Interface::as_binder))
+            }
+        }
+
+        impl<P: $crate::BinderAsyncPool> std::fmt::Debug for dyn $async_interface<P> + '_ {
+            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                f.pad(stringify!($async_interface))
+            }
+        }
+
+        /// Convert a &dyn $async_interface to Strong<dyn $async_interface>
+        impl<P: $crate::BinderAsyncPool> std::borrow::ToOwned for dyn $async_interface<P> {
+            type Owned = $crate::Strong<dyn $async_interface<P>>;
+            fn to_owned(&self) -> Self::Owned {
+                self.as_binder().into_interface()
+                    .expect(concat!("Error cloning interface ", stringify!($async_interface)))
+            }
+        }
+        )?
     };
 }