Implement derive macros (#1258)

commit-id:38af599e

---

**Stack**:
- #1264
- #1258 ⬅


⚠️ *Part of a stack created by [spr](https://github.com/ejoffe/spr). Do
not merge manually using the UI - doing so may have unexpected results.*

plugins/cairo-lang-macro-attributes/src/lib.rs

@@ -24,6 +24,16 @@ pub fn inline_macro(_args: TokenStream, input: TokenStream) -> TokenStream {
     macro_helper(input, quote!(::cairo_lang_macro::ExpansionKind::Inline))
 }
 
+/// Constructs the derive macro implementation.
+///
+/// This macro hides the conversion to stable ABI structs from the user.
+///
+/// Note, that this macro can be used multiple times, to define multiple independent attribute macros.
+#[proc_macro_attribute]
+pub fn derive_macro(_args: TokenStream, input: TokenStream) -> TokenStream {
+    macro_helper(input, quote!(::cairo_lang_macro::ExpansionKind::Derive))
+}
+
 fn macro_helper(input: TokenStream, kind: impl ToTokens) -> TokenStream {
     let item: ItemFn = parse_macro_input!(input as ItemFn);
     let original_item_name = item.sig.ident.to_string();