1 files changed, 47 insertions, 0 deletions
diff --git a/jsonrpc/jsonrpc_macro/src/lib.rs b/jsonrpc/jsonrpc_macro/src/lib.rs
new file mode 100644
index 0000000..f2015d4
--- /dev/null
+++ b/jsonrpc/jsonrpc_macro/src/lib.rs
@@ -0,0 +1,47 @@
+use proc_macro::TokenStream;
+use proc_macro2::{Ident, TokenStream as TokenStream2};
+use quote::quote;
+use syn::{parse_macro_input, spanned::Spanned, ImplItem, ItemImpl, Type};
+
+macro_rules! err {
+    ($($tt:tt)*) => {
+        return syn::Error::new($($tt)*).to_compile_error().into()
+    };
+}
+
+#[proc_macro_attribute]
+pub fn rpc_impl(_attr: TokenStream, item: TokenStream) -> TokenStream {
+    let mut methods: Vec<Ident> = vec![];
+
+    let item2 = item.clone();
+    let parsed_input = parse_macro_input!(item2 as ItemImpl);
+
+    let self_ty = match *parsed_input.self_ty {
+        Type::Path(p) => p,
+        _ => err!(
+            parsed_input.span(),
+            "implementing the trait `RPCService` on this type is unsupported"
+        ),
+    };
+
+    if parsed_input.items.is_empty() {
+        err!(self_ty.span(), "At least one method should be implemented");
+    }
+
+    for item in parsed_input.items {
+        match item {
+            ImplItem::Method(method) => {
+                methods.push(method.sig.ident);
+            }
+            _ => err!(item.span(), "unexpected item"),
+        }
+    }
+
+    let item2: TokenStream2 = item.into();
+    let quoted = quote! {
+            karyon_jsonrpc_internal::impl_rpc_service!(#self_ty, #(#methods),*);
+            #item2
+    };
+
+    quoted.into()
+}