RFC: glib-macros: port attribute parsing to use deluxe crate

glib-macros/Cargo.toml

@@ -17,13 +17,17 @@ heck = "0.4"
 proc-macro-error = "1.0"
 proc-macro2 = "1.0"
 quote = "1.0"
-syn = { version = "1.0", features = ["full"], default-features = false }
+syn = { version = "1.0", features = ["full", "visit-mut"], default-features = false }
 proc-macro-crate = "1.0"
+deluxe = "0.4.1"
 
 [lib]
 proc-macro = true
 
 [dev-dependencies]
+futures-channel = "0.3"
+futures-executor = "0.3"
+futures-util = "0.3"
 glib = { path = "../glib" }
 trybuild2 = "1.0"
 once_cell = "1.9.0"

glib-macros/src/boxed_derive.rs

@@ -1,10 +1,9 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
 use proc_macro2::{Ident, TokenStream};
-use proc_macro_error::abort_call_site;
 use quote::quote;
 
-use crate::utils::{crate_ident_new, find_attribute_meta, find_nested_meta, parse_name};
+use crate::utils::crate_ident_new;
 
 fn gen_option_to_ptr() -> TokenStream {
     quote! {
@@ -91,21 +90,22 @@ fn gen_impl_to_value_optional(name: &Ident, crate_ident: &TokenStream) -> TokenS
     }
 }
 
-pub fn impl_boxed(input: &syn::DeriveInput) -> TokenStream {
-    let name = &input.ident;
+#[derive(deluxe::ExtractAttributes, Default)]
+#[deluxe(attributes(boxed_type))]
+struct BoxedType {
+    name: String,
+    #[deluxe(default)]
+    nullable: bool,
+}
 
-    let gtype_name = match parse_name(input, "boxed_type") {
-        Ok(name) => name,
-        Err(e) => abort_call_site!(
-            "{}: #[derive(glib::Boxed)] requires #[boxed_type(name = \"BoxedTypeName\")]",
-            e
-        ),
-    };
+pub fn impl_boxed(mut input: syn::DeriveInput) -> TokenStream {
+    let name = &input.ident;
 
-    let meta = find_attribute_meta(&input.attrs, "boxed_type")
-        .unwrap()
-        .unwrap();
-    let nullable = find_nested_meta(&meta, "nullable").is_some();
+    let errors = deluxe::Errors::new();
+    let BoxedType {
+        name: gtype_name,
+        nullable,
+    } = deluxe::extract_attributes_optional(&mut input.attrs, &errors);
 
     let crate_ident = crate_ident_new();
 
@@ -121,6 +121,8 @@ pub fn impl_boxed(input: &syn::DeriveInput) -> TokenStream {
     };
 
     quote! {
+        #errors
+
         impl #crate_ident::subclass::boxed::BoxedType for #name {
             const NAME: &'static str = #gtype_name;
         }