codegen: Avoid generating wrong type for enums with unknown representation

src/codegen/mod.rs

@@ -2426,7 +2426,10 @@ impl CodeGenerator for Enum {
         let repr =
             self.repr()
                 .and_then(|repr| repr.try_to_rust_ty_or_opaque(ctx, &()).ok())
-                .unwrap_or_else(|| helpers::ast_ty::raw_type(ctx, repr_name));
+                .unwrap_or_else(|| {
+                    let repr_name = ctx.rust_ident_raw(repr_name);
+                    quote! { #repr_name }
+                });
 
         let mut builder = EnumBuilder::new(
             &name,

tests/expectations/tests/issue-1025-unknown-enum-repr.rs

@@ -0,0 +1,12 @@
+/* automatically generated by rust-bindgen */
+
+
+#![allow(dead_code, non_snake_case, non_camel_case_types, non_upper_case_globals)]
+
+
+#[repr(C)]
+#[derive(Debug, Default, Copy, Clone)]
+pub struct a {
+    pub _address: u8,
+}
+pub type a__bindgen_ty_1 = i32;

tests/headers/issue-1025-unknown-enum-repr.hpp

@@ -0,0 +1,4 @@
+
+template <typename> class a {
+  enum {};
+};