address review feedback

- add `type RawRep<T> = Option<T>` alias
- rename `Resource::take` to `Resource::into_inner`
- add `Resource::lift_borrow` and use it in code generator

Signed-off-by: Joel Dice <[email protected]>

crates/guest-rust/src/lib.rs

@@ -172,6 +172,8 @@ pub mod rt {
     }
 }
 
+type RawRep<T> = Option<T>;
+
 /// A type which represents a component model resource, either imported or
 /// exported into this component.
 ///
@@ -250,19 +252,27 @@ impl<T: WasmResource> Resource<T> {
     where
         T: RustResource,
     {
-        let _ = Box::from_raw(rep as *mut Option<T>);
+        let _ = Box::from_raw(rep as *mut RawRep<T>);
     }
 
     /// Takes back ownership of the object, dropping the resource handle.
-    pub fn take(resource: Self) -> T
+    pub fn into_inner(resource: Self) -> T
     where
         T: RustResource,
     {
         unsafe {
             let rep = T::rep(resource.handle);
-            Option::take(&mut *(rep as *mut Option<T>)).unwrap()
+            RawRep::take(&mut *(rep as *mut RawRep<T>)).unwrap()
         }
     }
+
+    #[doc(hidden)]
+    pub unsafe fn lift_borrow<'a>(rep: usize) -> &'a T
+    where
+        T: RustResource,
+    {
+        RawRep::as_ref(&*(rep as *const RawRep<T>)).unwrap()
+    }
 }
 
 impl<T: RustResource> Deref for Resource<T> {
@@ -271,7 +281,7 @@ impl<T: RustResource> Deref for Resource<T> {
     fn deref(&self) -> &T {
         unsafe {
             let rep = T::rep(self.handle);
-            Option::as_ref(&*(rep as *const Option<T>)).unwrap()
+            RawRep::as_ref(&*(rep as *const RawRep<T>)).unwrap()
         }
     }
 }
@@ -280,7 +290,7 @@ impl<T: RustResource> DerefMut for Resource<T> {
     fn deref_mut(&mut self) -> &mut T {
         unsafe {
             let rep = T::rep(self.handle);
-            Option::as_mut(&mut *(rep as *mut Option<T>)).unwrap()
+            RawRep::as_mut(&mut *(rep as *mut RawRep<T>)).unwrap()
         }
     }
 }

crates/rust/src/bindgen.rs

@@ -443,7 +443,10 @@ impl Bindgen for FunctionBindgen<'_, '_> {
                                     .as_deref()
                                     .unwrap()
                                     .to_upper_camel_case();
-                                format!("Option::as_ref(&*({op} as u32 as usize as *const Option<{name}>)).unwrap()")
+                                let rt = self.gen.gen.runtime_path();
+                                format!(
+                                    "{rt}::Resource::<{name}>::lift_borrow({op} as u32 as usize)"
+                                )
                             }
                             Handle::Own(_) => {
                                 let name = self.gen.type_path(resource, true);

crates/test-rust-wasm/src/bin/resource_into_inner.rs

@@ -0,0 +1,3 @@
+include!("../../../../tests/runtime/resource_into_inner/wasm.rs");
+
+fn main() {}

tests/runtime/main.rs

@@ -27,7 +27,7 @@ mod resource_borrow_import;
 mod resource_borrow_in_record;
 mod resource_floats;
 mod resource_import_and_export;
-mod resource_take;
+mod resource_into_inner;
 mod resource_with_lists;
 mod resources;
 mod smoke;

tests/runtime/resource_take.rs → tests/runtime/resource_into_inner.rs

@@ -1,16 +1,16 @@
 use wasmtime::Store;
 
-wasmtime::component::bindgen!(in "tests/runtime/resource_take");
+wasmtime::component::bindgen!(in "tests/runtime/resource_into_inner");
 
-use exports::test::resource_take::test::Test;
+use exports::test::resource_into_inner::test::Test;
 
 #[test]
 fn run() -> anyhow::Result<()> {
     crate::run_test(
-        "resource_take",
+        "resource_into_inner",
         |_| Ok(()),
         |store, component, linker| {
-            let (u, e) = ResourceTake::instantiate(store, component, linker)?;
+            let (u, e) = ResourceIntoInner::instantiate(store, component, linker)?;
             Ok((u.interface0, e))
         },
         run_test,

tests/runtime/resource_take/wasm.rs → tests/runtime/resource_into_inner/wasm.rs

@@ -1,13 +1,13 @@
 wit_bindgen::generate!({
-    path: "../../tests/runtime/resource_take",
+    path: "../../tests/runtime/resource_into_inner",
     exports: {
         world: Test,
-        "test:resource-take/test": Test,
-        "test:resource-take/test/thing": MyThing,
+        "test:resource-into-inner/test": Test,
+        "test:resource-into-inner/test/thing": MyThing,
     },
 });
 
-use exports::test::resource_take::test::{Guest, GuestThing};
+use exports::test::resource_into_inner::test::{Guest, GuestThing};
 use wit_bindgen::rt::Resource;
 
 pub struct Test;
@@ -17,7 +17,7 @@ impl Guest for Test {
         let text = "Jabberwocky";
         assert_eq!(
             text,
-            &Resource::take(Resource::new(MyThing(text.to_string()))).0
+            &Resource::into_inner(Resource::new(MyThing(text.to_string()))).0
         );
     }
 }

tests/runtime/resource_take/world.wit → tests/runtime/resource_into_inner/world.wit

@@ -1,4 +1,4 @@
-package test:resource-take;
+package test:resource-into-inner;
 
 interface test {
   resource thing {
@@ -8,6 +8,6 @@ interface test {
   test: func();
 }
 
-world resource-take {
+world resource-into-inner {
   export test;
 }