Make unshell-lib, and module system with components.

unshell-lib/src/module/mod.rs

@@ -0,0 +1,68 @@
+mod logger;
+mod manager;
+mod module;
+
+// use std::any::Any;
+
+pub use logger::setup_logger;
+pub use manager::Manager;
+pub use module::Module;
+
+pub trait Interface {
+    fn as_any(self: Box<Self>) -> Box<dyn std::any::Any>;
+}
+
+/// "Module Interface" helper macro that creates a struct with function pointers
+/// Useful for defining and requiring modules' functions accross FFI boundry.
+#[macro_export]
+macro_rules! module_interface {
+    ($(#[$struct_meta:meta])* $interface_name:ident { $($(#[$fn_meta:meta])* fn $fn_name:ident $(<$($gen:ident),+ $(,)?>)?($($arg:ident : $ty:ty),* $(,)?) $(-> $ret:ty)? $(where $($where_clause:tt)*)?);* $(;)? }) => {
+
+        #[repr(C)]
+        #[allow(non_camel_case_types)]
+        #[derive(Clone, Copy)]
+        #[allow(improper_ctypes_definitions)]
+        $(#[$struct_meta])*
+        pub struct $interface_name {
+            $(
+                // This line will FAIL TO COMPILE if you use generics in the macro input.
+                // You MUST use concrete types like *mut c_void for "generic" data.
+                $fn_name: extern "C" fn($($ty),*) $(-> $ret)?,
+            )*
+        }
+
+        impl $interface_name {
+            $(
+                #[inline(always)]
+                $(#[$fn_meta])* // Propagate function attributes
+                // This is the fix for the `impl` block.
+                // It adds the captured generics and where-clause to the wrapper function.
+                pub fn $fn_name $(<$($gen),+>)? (&self, $($arg: $ty),*) $(-> $ret)?
+                $(where $($where_clause)*)?
+                {
+                    (self.$fn_name)($($arg),*)
+                }
+            )*
+
+            /// Create from raw function pointers
+            ///
+            /// # Safety
+            ///
+            /// The caller must ensure all function pointers are valid and have
+            /// the correct signatures
+            pub fn from_raw(
+                $($fn_name: extern "C" fn($($ty),*) $(-> $ret)?),*
+            ) -> Self {
+                Self {
+                    $($fn_name),*
+                }
+            }
+        }
+
+        impl crate::module::Interface for $interface_name {
+            fn as_any(self: Box<Self>) -> Box<dyn std::any::Any> {
+                self
+            }
+        }
+    };
+}