Revert^2 "[binder] Expose public Rust API at crate top level"

Previously the public API for the binder Rust crate was nested in a
`public_api` module and re-exported by AIDL interface crates. This
caused confusion, when using multiple AIDL interfaces in the same file,
as there were multiple options to import the binder API.

Moves the public API to the top level of the binder crate and nests the
AIDL implementation API into a submodule.

Original change: I811426fa715a324ebb09f5ce04ee539a1c3b9dfd

Test: atest -p --include-subdirs frameworks/native/binder
Bug: 196056781

Change-Id: I7aa0aa41e4162bb25720974065ae3ac8069e6598
diff --git a/libs/binder/rust/src/binder.rs b/libs/binder/rust/src/binder.rs
index 4d6b294..7895a72 100644
--- a/libs/binder/rust/src/binder.rs
+++ b/libs/binder/rust/src/binder.rs
@@ -536,13 +536,13 @@
 /// ```
 macro_rules! binder_fn_get_class {
     ($class:ty) => {
-        binder_fn_get_class!($crate::InterfaceClass::new::<$class>());
+        binder_fn_get_class!($crate::binder_impl::InterfaceClass::new::<$class>());
     };
 
     ($constructor:expr) => {
-        fn get_class() -> $crate::InterfaceClass {
+        fn get_class() -> $crate::binder_impl::InterfaceClass {
             static CLASS_INIT: std::sync::Once = std::sync::Once::new();
-            static mut CLASS: Option<$crate::InterfaceClass> = None;
+            static mut CLASS: Option<$crate::binder_impl::InterfaceClass> = None;
 
             CLASS_INIT.call_once(|| unsafe {
                 // Safety: This assignment is guarded by the `CLASS_INIT` `Once`
@@ -772,7 +772,7 @@
                 native: $native($on_transact),
                 proxy: $proxy {},
                 $(async: $async_interface,)?
-                stability: $crate::Stability::default(),
+                stability: $crate::binder_impl::Stability::default(),
             }
         }
     };
@@ -811,7 +811,7 @@
                     $($fname: $fty = $finit),*
                 },
                 $(async: $async_interface,)?
-                stability: $crate::Stability::default(),
+                stability: $crate::binder_impl::Stability::default(),
             }
         }
     };
@@ -828,9 +828,9 @@
     } => {
         $crate::declare_binder_interface! {
             $interface[$descriptor] {
-                @doc[concat!("A binder [`Remotable`]($crate::Remotable) that holds an [`", stringify!($interface), "`] object.")]
+                @doc[concat!("A binder [`Remotable`]($crate::binder_impl::Remotable) that holds an [`", stringify!($interface), "`] object.")]
                 native: $native($on_transact),
-                @doc[concat!("A binder [`Proxy`]($crate::Proxy) that holds an [`", stringify!($interface), "`] remote interface.")]
+                @doc[concat!("A binder [`Proxy`]($crate::binder_impl::Proxy) that holds an [`", stringify!($interface), "`] remote interface.")]
                 proxy: $proxy {
                     $($fname: $fty = $finit),*
                 },
@@ -867,7 +867,7 @@
             }
         }
 
-        impl $crate::Proxy for $proxy
+        impl $crate::binder_impl::Proxy for $proxy
         where
             $proxy: $interface,
         {
@@ -875,7 +875,7 @@
                 $descriptor
             }
 
-            fn from_binder(mut binder: $crate::SpIBinder) -> $crate::Result<Self> {
+            fn from_binder(mut binder: $crate::SpIBinder) -> std::result::Result<Self, $crate::StatusCode> {
                 Ok(Self { binder, $($fname: $finit),* })
             }
         }
@@ -887,19 +887,19 @@
         impl $native {
             /// Create a new binder service.
             pub fn new_binder<T: $interface + Sync + Send + 'static>(inner: T, features: $crate::BinderFeatures) -> $crate::Strong<dyn $interface> {
-                let mut binder = $crate::Binder::new_with_stability($native(Box::new(inner)), $stability);
+                let mut binder = $crate::binder_impl::Binder::new_with_stability($native(Box::new(inner)), $stability);
                 #[cfg(not(android_vndk))]
-                $crate::IBinderInternal::set_requesting_sid(&mut binder, features.set_requesting_sid);
+                $crate::binder_impl::IBinderInternal::set_requesting_sid(&mut binder, features.set_requesting_sid);
                 $crate::Strong::new(Box::new(binder))
             }
         }
 
-        impl $crate::Remotable for $native {
+        impl $crate::binder_impl::Remotable for $native {
             fn get_descriptor() -> &'static str {
                 $descriptor
             }
 
-            fn on_transact(&self, code: $crate::TransactionCode, data: &$crate::BorrowedParcel<'_>, reply: &mut $crate::BorrowedParcel<'_>) -> $crate::Result<()> {
+            fn on_transact(&self, code: $crate::binder_impl::TransactionCode, data: &$crate::binder_impl::BorrowedParcel<'_>, reply: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
                 match $on_transact(&*self.0, code, data, reply) {
                     // The C++ backend converts UNEXPECTED_NULL into an exception
                     Err($crate::StatusCode::UNEXPECTED_NULL) => {
@@ -913,19 +913,19 @@
                 }
             }
 
-            fn on_dump(&self, file: &std::fs::File, args: &[&std::ffi::CStr]) -> $crate::Result<()> {
+            fn on_dump(&self, file: &std::fs::File, args: &[&std::ffi::CStr]) -> std::result::Result<(), $crate::StatusCode> {
                 self.0.dump(file, args)
             }
 
-            fn get_class() -> $crate::InterfaceClass {
+            fn get_class() -> $crate::binder_impl::InterfaceClass {
                 static CLASS_INIT: std::sync::Once = std::sync::Once::new();
-                static mut CLASS: Option<$crate::InterfaceClass> = None;
+                static mut CLASS: Option<$crate::binder_impl::InterfaceClass> = None;
 
                 CLASS_INIT.call_once(|| unsafe {
                     // Safety: This assignment is guarded by the `CLASS_INIT` `Once`
                     // variable, and therefore is thread-safe, as it can only occur
                     // once.
-                    CLASS = Some($crate::InterfaceClass::new::<$crate::Binder<$native>>());
+                    CLASS = Some($crate::binder_impl::InterfaceClass::new::<$crate::binder_impl::Binder<$native>>());
                 });
                 unsafe {
                     // Safety: The `CLASS` variable can only be mutated once, above,
@@ -936,25 +936,25 @@
         }
 
         impl $crate::FromIBinder for dyn $interface {
-            fn try_from(mut ibinder: $crate::SpIBinder) -> $crate::Result<$crate::Strong<dyn $interface>> {
-                use $crate::AssociateClass;
+            fn try_from(mut ibinder: $crate::SpIBinder) -> std::result::Result<$crate::Strong<dyn $interface>, $crate::StatusCode> {
+                use $crate::binder_impl::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 $crate::Remotable>::get_descriptor()
+                    if class != <$native as $crate::binder_impl::Remotable>::get_class() &&
+                        class.get_descriptor() == <$native as $crate::binder_impl::Remotable>::get_descriptor()
                     {
                         // The binder object's descriptor string matches what we
                         // expect. We still need to treat this local or already
                         // associated object as remote, because we can't cast it
                         // into a Rust service object without a matching class
                         // pointer.
-                        return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
+                        return Ok($crate::Strong::new(Box::new(<$proxy as $crate::binder_impl::Proxy>::from_binder(ibinder)?)));
                     }
                 }
 
-                if ibinder.associate_class(<$native as $crate::Remotable>::get_class()) {
-                    let service: $crate::Result<$crate::Binder<$native>> =
+                if ibinder.associate_class(<$native as $crate::binder_impl::Remotable>::get_class()) {
+                    let service: std::result::Result<$crate::binder_impl::Binder<$native>, $crate::StatusCode> =
                         std::convert::TryFrom::try_from(ibinder.clone());
                     if let Ok(service) = service {
                         // We were able to associate with our expected class and
@@ -962,7 +962,7 @@
                         return Ok($crate::Strong::new(Box::new(service)));
                     } else {
                         // Service is remote
-                        return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
+                        return Ok($crate::Strong::new(Box::new(<$proxy as $crate::binder_impl::Proxy>::from_binder(ibinder)?)));
                     }
                 }
 
@@ -970,18 +970,18 @@
             }
         }
 
-        impl $crate::parcel::Serialize for dyn $interface + '_
+        impl $crate::binder_impl::Serialize for dyn $interface + '_
         where
             dyn $interface: $crate::Interface
         {
-            fn serialize(&self, parcel: &mut $crate::parcel::BorrowedParcel<'_>) -> $crate::Result<()> {
+            fn serialize(&self, parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
                 let binder = $crate::Interface::as_binder(self);
                 parcel.write(&binder)
             }
         }
 
-        impl $crate::parcel::SerializeOption for dyn $interface + '_ {
-            fn serialize_option(this: Option<&Self>, parcel: &mut $crate::parcel::BorrowedParcel<'_>) -> $crate::Result<()> {
+        impl $crate::binder_impl::SerializeOption for dyn $interface + '_ {
+            fn serialize_option(this: Option<&Self>, parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
                 parcel.write(&this.map($crate::Interface::as_binder))
             }
         }
@@ -1004,25 +1004,25 @@
         $(
         // 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;
+            fn try_from(mut ibinder: $crate::SpIBinder) -> std::result::Result<$crate::Strong<dyn $async_interface<P>>, $crate::StatusCode> {
+                use $crate::binder_impl::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 $crate::Remotable>::get_descriptor()
+                    if class != <$native as $crate::binder_impl::Remotable>::get_class() &&
+                        class.get_descriptor() == <$native as $crate::binder_impl::Remotable>::get_descriptor()
                     {
                         // The binder object's descriptor string matches what we
                         // expect. We still need to treat this local or already
                         // associated object as remote, because we can't cast it
                         // into a Rust service object without a matching class
                         // pointer.
-                        return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
+                        return Ok($crate::Strong::new(Box::new(<$proxy as $crate::binder_impl::Proxy>::from_binder(ibinder)?)));
                     }
                 }
 
-                if ibinder.associate_class(<$native as $crate::Remotable>::get_class()) {
-                    let service: $crate::Result<$crate::Binder<$native>> =
+                if ibinder.associate_class(<$native as $crate::binder_impl::Remotable>::get_class()) {
+                    let service: std::result::Result<$crate::binder_impl::Binder<$native>, $crate::StatusCode> =
                         std::convert::TryFrom::try_from(ibinder.clone());
                     if let Ok(service) = service {
                         // We were able to associate with our expected class and
@@ -1031,7 +1031,7 @@
                         //return Ok($crate::Strong::new(Box::new(service)));
                     } else {
                         // Service is remote
-                        return Ok($crate::Strong::new(Box::new(<$proxy as $crate::Proxy>::from_binder(ibinder)?)));
+                        return Ok($crate::Strong::new(Box::new(<$proxy as $crate::binder_impl::Proxy>::from_binder(ibinder)?)));
                     }
                 }
 
@@ -1039,15 +1039,15 @@
             }
         }
 
-        impl<P: $crate::BinderAsyncPool> $crate::parcel::Serialize for dyn $async_interface<P> + '_ {
-            fn serialize(&self, parcel: &mut $crate::parcel::BorrowedParcel<'_>) -> $crate::Result<()> {
+        impl<P: $crate::BinderAsyncPool> $crate::binder_impl::Serialize for dyn $async_interface<P> + '_ {
+            fn serialize(&self, parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
                 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::BorrowedParcel<'_>) -> $crate::Result<()> {
+        impl<P: $crate::BinderAsyncPool> $crate::binder_impl::SerializeOption for dyn $async_interface<P> + '_ {
+            fn serialize_option(this: Option<&Self>, parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
                 parcel.write(&this.map($crate::Interface::as_binder))
             }
         }
@@ -1067,11 +1067,11 @@
             }
         }
 
-        impl<P: $crate::BinderAsyncPool> $crate::ToAsyncInterface<P> for dyn $interface {
+        impl<P: $crate::BinderAsyncPool> $crate::binder_impl::ToAsyncInterface<P> for dyn $interface {
             type Target = dyn $async_interface<P>;
         }
 
-        impl<P: $crate::BinderAsyncPool> $crate::ToSyncInterface for dyn $async_interface<P> {
+        impl<P: $crate::BinderAsyncPool> $crate::binder_impl::ToSyncInterface for dyn $async_interface<P> {
             type Target = dyn $interface;
         }
         )?
@@ -1103,29 +1103,29 @@
             }
         }
 
-        impl $crate::parcel::Serialize for $enum {
-            fn serialize(&self, parcel: &mut $crate::parcel::BorrowedParcel<'_>) -> $crate::Result<()> {
+        impl $crate::binder_impl::Serialize for $enum {
+            fn serialize(&self, parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
                 parcel.write(&self.0)
             }
         }
 
-        impl $crate::parcel::SerializeArray for $enum {
-            fn serialize_array(slice: &[Self], parcel: &mut $crate::parcel::BorrowedParcel<'_>) -> $crate::Result<()> {
+        impl $crate::binder_impl::SerializeArray for $enum {
+            fn serialize_array(slice: &[Self], parcel: &mut $crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<(), $crate::StatusCode> {
                 let v: Vec<$backing> = slice.iter().map(|x| x.0).collect();
-                <$backing as binder::parcel::SerializeArray>::serialize_array(&v[..], parcel)
+                <$backing as $crate::binder_impl::SerializeArray>::serialize_array(&v[..], parcel)
             }
         }
 
-        impl $crate::parcel::Deserialize for $enum {
-            fn deserialize(parcel: &$crate::parcel::BorrowedParcel<'_>) -> $crate::Result<Self> {
+        impl $crate::binder_impl::Deserialize for $enum {
+            fn deserialize(parcel: &$crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<Self, $crate::StatusCode> {
                 parcel.read().map(Self)
             }
         }
 
-        impl $crate::parcel::DeserializeArray for $enum {
-            fn deserialize_array(parcel: &$crate::parcel::BorrowedParcel<'_>) -> $crate::Result<Option<Vec<Self>>> {
+        impl $crate::binder_impl::DeserializeArray for $enum {
+            fn deserialize_array(parcel: &$crate::binder_impl::BorrowedParcel<'_>) -> std::result::Result<Option<Vec<Self>>, $crate::StatusCode> {
                 let v: Option<Vec<$backing>> =
-                    <$backing as binder::parcel::DeserializeArray>::deserialize_array(parcel)?;
+                    <$backing as $crate::binder_impl::DeserializeArray>::deserialize_array(parcel)?;
                 Ok(v.map(|v| v.into_iter().map(Self).collect()))
             }
         }