Work on macro binding generation, some cleanup needed, rename runner to plugin

crates/plugin_macros/src/lib.rs

@@ -0,0 +1,45 @@
+use core::panic;
+
+use proc_macro::TokenStream;
+use quote::{format_ident, quote};
+use syn::{parse_macro_input, ItemFn, VisPublic, Visibility};
+
+#[proc_macro_attribute]
+pub fn bind(args: TokenStream, function: TokenStream) -> TokenStream {
+    if !args.is_empty() {
+        panic!("The bind attribute does not take any arguments");
+    }
+
+    let inner_fn = parse_macro_input!(function as ItemFn);
+    if let Visibility::Public(_) = inner_fn.vis {
+    } else {
+        panic!("The bind attribute only works for public functions");
+    }
+
+    let inner_fn_name = format_ident!("{}", inner_fn.sig.ident);
+    let outer_fn_name = format_ident!("__{}", inner_fn_name);
+
+    TokenStream::from(quote! {
+        use serde;
+
+        #[no_mangle]
+        #inner_fn
+
+        #[no_mangle]
+        pub extern "C" fn #outer_fn_name(ptr: *const u8, len: usize) -> *const Buffer {
+            // setup
+            let buffer = Buffer { ptr, len };
+            let data = unsafe { buffer.to_vec() };
+
+            // operation
+            let argument = bincode::deserialize(&data).unwrap();
+            let result = #inner_fn_name(argument);
+            let new_data: Result<Vec<u8>, _> = bincode::serialize(&result);
+            let new_data = new_data.unwrap();
+
+            // teardown
+            let new_buffer = unsafe { Buffer::from_vec(new_data) };
+            return new_buffer.leak_to_heap();
+        }
+    })
+}