Method with_lower_context

crates/wasmtime/src/runtime/component/func.rs:668–686

Creates a `LowerContext` using the configuration values of this lifted function. The `lower` closure provided should perform the actual lowering and return the result of the lowering operation which is then returned from this function as well.

(
        self,
        mut store: StoreContextMut<T>,
        lower: impl FnOnce(&mut LowerContext<T>, InterfaceType) -> Result<()>,
    )

    /// return the result of the lowering operation which is then returned from
    /// this function as well.
    pub(crate) fn with_lower_context<T>(
        self,
        mut store: StoreContextMut<T>,
        lower: impl FnOnce(&mut LowerContext<T>, InterfaceType) -> Result<()>,
    ) -> Result<()> {
        let (options_idx, mut flags, ty, _) = self.abi_info(store.0);

        // Perform the actual lowering, where while this is running the
        // component is forbidden from calling imports.
        unsafe {
            debug_assert!(flags.may_leave());
            flags.set_may_leave(false);
        }
        let mut cx = LowerContext::new(store.as_context_mut(), options_idx, self.instance);
        let param_ty = InterfaceType::Tuple(cx.types[ty].params);
        let result = lower(&mut cx, param_ty);
        unsafe { flags.set_may_leave(true) };
        result
    }

    /// Creates a `LiftContext` using the configuration values with this lifted
    /// function.