Let modules decide their own name via #[cdef] macro

crates/luaffi_impl/src/cdef.rs

@@ -5,18 +5,26 @@ use quote::{format_ident, quote, quote_spanned};
 use syn::{ext::IdentExt, spanned::Spanned, *};
 
 #[derive(Debug, FromMeta)]
-pub struct Args {}
+pub struct Args {
+    module: Option<String>,
+}
 
-pub fn transform(_args: Args, mut item: Item) -> Result<TokenStream> {
-    let (name, impl_type, impl_cdef) = match item {
+pub fn transform(args: Args, mut item: Item) -> Result<TokenStream> {
+    let (name, impl_type, impl_module, impl_cdef) = match item {
         Item::Struct(ref mut str) => (
             str.ident.clone(),
             generate_type(&str.ident)?,
+            args.module
+                .map(|name| generate_module(&name, &str.ident))
+                .transpose()?,
             generate_cdef_structure(str)?,
         ),
         Item::Enum(ref mut enu) => (
             enu.ident.clone(),
             generate_type(&enu.ident)?,
+            args.module
+                .map(|name| generate_module(&name, &enu.ident))
+                .transpose()?,
             generate_cdef_enum(enu)?,
         ),
         _ => syn_error!(item, "expected struct or enum"),
@@ -35,6 +43,7 @@ pub fn transform(_args: Args, mut item: Item) -> Result<TokenStream> {
         mod #mod_name {
             use super::*;
             #impl_type
+            #impl_module
             #impl_cdef
         }
     ))
@@ -47,9 +56,7 @@ fn generate_type(ty: &Ident) -> Result<TokenStream> {
 
     Ok(quote_spanned!(span =>
         unsafe impl #ffi::Type for #ty {
-            fn name() -> impl ::std::fmt::Display {
-                #name
-            }
+            fn name() -> impl ::std::fmt::Display { #name }
 
             fn ty() -> #ffi::TypeType {
                 #ffi::TypeType::Aggregate
@@ -72,6 +79,16 @@ fn generate_type(ty: &Ident) -> Result<TokenStream> {
     ))
 }
 
+fn generate_module(name: &str, ty: &Ident) -> Result<TokenStream> {
+    let ffi = ffi_crate();
+
+    Ok(quote_spanned!(ty.span() =>
+        impl #ffi::Module for #ty {
+            fn name() -> impl ::std::fmt::Display { #name }
+        }
+    ))
+}
+
 fn generate_cdef_structure(str: &mut ItemStruct) -> Result<TokenStream> {
     syn_assert!(
         str.generics.params.is_empty(),
@@ -155,12 +172,11 @@ fn parse_cfield_attrs(attrs: &mut Vec<Attribute>) -> Result<CFieldAttrs> {
     let mut parsed = CFieldAttrs::default();
     let mut i = 0;
     while let Some(attr) = attrs.get(i) {
-        if let Some(name) = attr.path().get_ident() {
-            if name == "opaque" {
-                parsed.opaque = true;
-                attrs.remove(i);
-                continue;
-            }
+        let path = attr.path();
+        if path.is_ident("opaque") {
+            parsed.opaque = true;
+            attrs.remove(i);
+            continue;
         }
         i += 1;
     }