From 269acc9a152379c453fed76090a3bc69d680edbe Mon Sep 17 00:00:00 2001
From: Roland Fredenhagen <dev@modprog.de>
Date: Mon, 7 Aug 2023 15:31:24 +0700
Subject: [PATCH] verify supported protocol in parsing step

---
 crates/rune-macros/src/context.rs | 25 ++++++++++++++++---------
 crates/rune-macros/src/lib.rs     |  2 +-
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/crates/rune-macros/src/context.rs b/crates/rune-macros/src/context.rs
index d5503312d..4914b64d4 100644
--- a/crates/rune-macros/src/context.rs
+++ b/crates/rune-macros/src/context.rs
@@ -135,36 +135,43 @@ impl TypeProtocol {
                 module.associated_function(rune::runtime::Protocol::ADD, |this: Self, other: Self| this + other)?;
             },
             "STRING_DISPLAY" => quote_spanned! {self.protocol.span()=>
-                module.associated_function(rune::runtime::Protocol::STRING_DISPLAY, |this: &Self, buf: &mut String| {
+                module.associated_function(rune::runtime::Protocol::STRING_DISPLAY, |this: &Self, buf: &mut ::std::string::String| {
                     use ::core::fmt::Write as _;
                     ::core::write!(buf, "{this}")
                 })?;
             },
             "STRING_DEBUG" => quote_spanned! {self.protocol.span()=>
-                module.associated_function(rune::runtime::Protocol::STRING_DEBUG, |this: &Self, buf: &mut String| {
+                module.associated_function(rune::runtime::Protocol::STRING_DEBUG, |this: &Self, buf: &mut ::std::string::String| {
                     use ::core::fmt::Write as _;
                     ::core::write!(buf, "{this:?}")
                 })?;
             },
-            _ => syn::Error::new_spanned(
-                &self.protocol,
-                format!("Rune protocol `{}` cannot be derived", self.protocol),
-            )
-            .to_compile_error(),
+            _ => unreachable!("`parse()` ensures only supported protocols")
         }
     }
 }
 
 impl Parse for TypeProtocol {
     fn parse(input: ParseStream) -> syn::Result<Self> {
-        Ok(Self {
+        let it = Self {
             protocol: input.parse()?,
             handler: if input.parse::<Token![=]>().is_ok() {
                 Some(input.parse()?)
             } else {
                 None
             },
-        })
+        };
+
+        if it.handler.is_some()
+            || ["ADD", "STRING_DISPLAY", "STRING_DEBUG"].contains(&it.protocol.to_string().as_str())
+        {
+            Ok(it)
+        } else {
+            Err(syn::Error::new_spanned(
+                &it.protocol,
+                format!("Rune protocol `{}` cannot be derived", it.protocol),
+            ))
+        }
     }
 }
 
diff --git a/crates/rune-macros/src/lib.rs b/crates/rune-macros/src/lib.rs
index daf934386..165f7e123 100644
--- a/crates/rune-macros/src/lib.rs
+++ b/crates/rune-macros/src/lib.rs
@@ -155,7 +155,7 @@ pub fn to_value(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
         .into()
 }
 
-#[proc_macro_derive(Any, attributes(rune))]
+#[proc_macro_derive(Any, attributes(rune, rune_derive, rune_functions))]
 pub fn any(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
     let derive = syn::parse_macro_input!(input as any::Derive);
     derive.expand().unwrap_or_else(to_compile_errors).into()