Revert "Allow #[cppgc] &mut T in sync ops (#791)"

This reverts commit 3cc4464.

core/cppgc.rs

@@ -43,17 +43,10 @@ pub fn make_cppgc_object<'a, T: GcResource + 'static>(
   obj
 }
 
-// TODO(littledivy): https://github.com/denoland/rusty_v8/pull/1505
-#[repr(C)]
-struct InnerMember {
-  inner: [usize; 2],
-  ptr: *mut (),
-}
-
 #[allow(clippy::needless_lifetimes)]
 pub fn try_unwrap_cppgc_object<'sc, T: GcResource + 'static>(
   val: v8::Local<'sc, v8::Value>,
-) -> Option<&'sc mut T> {
+) -> Option<&'sc T> {
   let Ok(obj): Result<v8::Local<v8::Object>, _> = val.try_into() else {
     return None;
   };
@@ -69,13 +62,13 @@ pub fn try_unwrap_cppgc_object<'sc, T: GcResource + 'static>(
   // The object can only be created by `make_cppgc_object`.
   let member = unsafe {
     let ptr = obj.get_aligned_pointer_from_internal_field(SLOT_OFFSET);
-    let obj = &*(ptr as *mut InnerMember);
-    obj.ptr.cast::<CppGcObject<T>>().as_mut().unwrap()
+    let obj = &*(ptr as *const v8::cppgc::InnerMember);
+    obj.get::<CppGcObject<T>>()
   };
 
   if member.tag != TypeId::of::<T>() {
     return None;
   }
 
-  Some(&mut member.member)
+  Some(&member.member)
 }

core/runtime/ops.rs

@@ -610,7 +610,6 @@ mod tests {
       op_test_get_cppgc_resource,
       op_test_get_cppgc_resource_option,
       op_test_make_cppgc_resource,
-      op_test_set_cppgc_resource,
       op_test_make_cppgc_resource_option,
       op_external_make,
       op_external_process,
@@ -1928,14 +1927,6 @@ mod tests {
     resource.value
   }
 
-  #[op2(fast)]
-  pub fn op_test_set_cppgc_resource(
-    #[cppgc] resource: &mut TestResource,
-    value: u32,
-  ) {
-    resource.value = value;
-  }
-
   #[op2(fast)]
   #[smi]
   pub fn op_test_get_cppgc_resource_option(
@@ -1953,7 +1944,7 @@ mod tests {
   {
     run_async_test(
       10,
-      "op_test_make_cppgc_resource, op_test_get_cppgc_resource, op_test_get_cppgc_resource_option, op_test_make_cppgc_resource_option, op_test_set_cppgc_resource",
+      "op_test_make_cppgc_resource, op_test_get_cppgc_resource, op_test_get_cppgc_resource_option, op_test_make_cppgc_resource_option",
       r"
       const resource = op_test_make_cppgc_resource();
       assert((await op_test_get_cppgc_resource(resource)) === 42);
@@ -1962,9 +1953,7 @@ mod tests {
       const resource2 = op_test_make_cppgc_resource_option(false);
       assert(resource2 === null);
       const resource3 = op_test_make_cppgc_resource_option(true);
-      assert((await op_test_get_cppgc_resource(resource3)) === 42);
-      op_test_set_cppgc_resource(resource, 43);
-      assert((await op_test_get_cppgc_resource(resource)) == 43);"
+      assert((await op_test_get_cppgc_resource(resource3)) === 42);",
     ).await?;
     Ok(())
   }

ops/op2/dispatch_async.rs

@@ -47,7 +47,7 @@ pub(crate) fn generate_dispatch_async(
   let mut output = TokenStream::new();
 
   let with_self = if generator_state.needs_self {
-    with_self(generator_state, true, &signature.ret_val)
+    with_self(generator_state, &signature.ret_val)
       .map_err(V8SignatureMappingError::NoSelfMapping)?
   } else {
     quote!()

ops/op2/dispatch_fast.rs

@@ -757,7 +757,7 @@ fn map_v8_fastcall_arg_to_arg(
         let #arg_ident = if #arg_ident.is_null_or_undefined() {
           None
         } else if let Some(#arg_ident) = deno_core::_ops::try_unwrap_cppgc_object::<#ty>(#arg_ident) {
-          Some(#arg_ident as _)
+          Some(#arg_ident)
         } else {
           #fast_api_callback_options.fallback = true;
           // SAFETY: All fast return types have zero as a valid value

ops/op2/dispatch_slow.rs

@@ -92,7 +92,7 @@ pub(crate) fn generate_dispatch_slow(
   )?);
 
   let with_self = if generator_state.needs_self {
-    with_self(generator_state, false, &signature.ret_val)
+    with_self(generator_state, &signature.ret_val)
       .map_err(V8SignatureMappingError::NoSelfMapping)?
   } else {
     quote!()
@@ -246,7 +246,6 @@ pub(crate) fn with_js_runtime_state(
 
 pub(crate) fn with_self(
   generator_state: &mut GeneratorState,
-  is_async: bool,
   ret_val: &RetVal,
 ) -> Result<TokenStream, V8MappingError> {
   generator_state.needs_opctx = true;
@@ -255,7 +254,6 @@ pub(crate) fn with_self(
     format!("expected {}", &generator_state.self_ty),
   )?;
   let tokens = if matches!(ret_val, RetVal::Future(_) | RetVal::FutureResult(_))
-    || is_async
   {
     let tokens = gs_quote!(generator_state(self_ty, fn_args, scope) => {
       let Some(self_) = deno_core::_ops::CppGcObjectGuard::<#self_ty>::try_new_from_cppgc_object(&mut *#scope, #fn_args.this().into()) else {
@@ -619,7 +617,7 @@ pub fn from_arg(
           let #arg_ident = if #arg_ident.is_null_or_undefined() {
             None
           } else if let Some(#arg_ident) = deno_core::_ops::try_unwrap_cppgc_object::<#ty>(#arg_ident) {
-            Some(#arg_ident as _)
+            Some(#arg_ident)
           } else {
             #throw_exception;
           };

ops/op2/signature.rs

@@ -1473,17 +1473,19 @@ fn parse_type_state(ty: &Type) -> Result<Arg, ArgError> {
 
 fn parse_cppgc(position: Position, ty: &Type) -> Result<Arg, ArgError> {
   match (position, ty) {
-    (Position::Arg, Type::Reference(of)) => match &*of.elem {
-      Type::Path(of) => Ok(Arg::CppGcResource(stringify_token(&of.path))),
-      _ => Err(ArgError::InvalidCppGcType(stringify_token(ty))),
-    },
+    (Position::Arg, Type::Reference(of)) if of.mutability.is_none() => {
+      match &*of.elem {
+        Type::Path(of) => Ok(Arg::CppGcResource(stringify_token(&of.path))),
+        _ => Err(ArgError::InvalidCppGcType(stringify_token(&of.elem))),
+      }
+    }
     (Position::Arg, Type::Path(of)) => {
       rules!(of.to_token_stream() => {
         ( Option < $ty:ty $(,)? > ) => {
           match ty {
-            Type::Reference(of) => {
+            Type::Reference(of) if of.mutability.is_none() => {
               match &*of.elem {
-                Type::Path(f) => Ok(Arg::OptionCppGcResource(stringify_token(&f.path))),
+                Type::Path(of) => Ok(Arg::OptionCppGcResource(stringify_token(&of.path))),
                 _ => Err(ArgError::InvalidCppGcType(stringify_token(&of.elem))),
               }
             }
@@ -2048,7 +2050,7 @@ mod tests {
   );
   expect_fail!(
     op_cppgc_resource_invalid_type,
-    ArgError("resource", InvalidCppGcType("&[std :: fs :: File]")),
+    ArgError("resource", InvalidCppGcType("[std :: fs :: File]")),
     fn f(#[cppgc] resource: &[std::fs::File]) {}
   );
   expect_fail!(

ops/op2/test_cases/sync/cppgc_resource.rs

@@ -22,9 +22,6 @@ fn op_make_cppgc_object() -> Wrap {
 #[op2(fast)]
 fn op_use_cppgc_object(#[cppgc] _wrap: &Wrap) {}
 
-#[op2(fast)]
-fn op_use_cppgc_object_mut(#[cppgc] _wrap: &mut Wrap) {}
-
 #[op2]
 #[cppgc]
 fn op_make_cppgc_object_option() -> Option<Wrap> {

ops/op2/test_cases_fail/lifetimes.rs

@@ -14,6 +14,3 @@ fn op_use_cppgc_object(#[cppgc] _wrap: &'static Wrap) {}
 
 #[op2(fast)]
 fn op_use_buffer(#[buffer] _buffer: &'static [u8]) {}
-
-#[op2(async)]
-async fn op_use_cppgc_object_mut_async(#[cppgc] _wrap: &mut Wrap) {}