Add wasm extern type trait

lib/runtime-core/src/macros.rs

@@ -17,49 +17,21 @@ macro_rules! func {
     ($func:ident, [ $( $params:ident ),* ] -> [ $( $returns:ident ),* ] ) => {{
         use $crate::{
             export::{Context, Export, FuncPointer},
-            types::{FuncSig, Type},
+            types::{FuncSig, Type, WasmExternType},
             vm,
         };
-
         let func: extern fn( $( $params, )* &mut vm::Ctx) -> ($( $returns )*) = $func;
-
         Export::Function {
             func: unsafe { FuncPointer::new(func as _) },
             ctx: Context::Internal,
             signature: FuncSig::new(
-                &[$($crate::__export_func_convert_type!($params),)*] as &[Type],
+                &[ $( <$params as WasmExternType>::TYPE, )* ] as &[Type],
-                &[$($crate::__export_func_convert_type!($returns),)*] as &[Type],
+                &[ $( <$returns as WasmExternType>::TYPE, )* ] as &[Type],
             ).into(),
         }
     }};
 }
 
-#[macro_export]
-#[doc(hidden)]
-macro_rules! __export_func_convert_type {
-    (i32) => {
-        Type::I32
-    };
-    (u32) => {
-        Type::I32
-    };
-    (i64) => {
-        Type::I64
-    };
-    (u64) => {
-        Type::I64
-    };
-    (f32) => {
-        Type::F32
-    };
-    (f64) => {
-        Type::F64
-    };
-    ($x:ty) => {
-        compile_error!("Only `i32`, `u32`, `i64`, `u64`, `f32`, and `f64` are supported for argument and return types")
-    };
-}
-
 /// Generate an [`ImportObject`] safely.
 ///
 /// [`ImportObject`]: struct.ImportObject.html

lib/runtime-core/src/types.rs

@@ -65,6 +65,31 @@ impl From<f64> for Value {
     }
 }
 
+pub unsafe trait WasmExternType: Copy + Clone
+where
+    Self: Sized,
+{
+    const TYPE: Type;
+}
+unsafe impl WasmExternType for i32 {
+    const TYPE: Type = Type::I32;
+}
+unsafe impl WasmExternType for u32 {
+    const TYPE: Type = Type::I32;
+}
+unsafe impl WasmExternType for i64 {
+    const TYPE: Type = Type::I64;
+}
+unsafe impl WasmExternType for u64 {
+    const TYPE: Type = Type::I64;
+}
+unsafe impl WasmExternType for f32 {
+    const TYPE: Type = Type::F32;
+}
+unsafe impl WasmExternType for f64 {
+    const TYPE: Type = Type::F64;
+}
+
 pub enum ValueError {
     BufferTooSmall,
 }