Auto-generate rbs_ast_ruby_annotations_t union from config.yml

The union `rbs_ast_ruby_annotations_t` was previously maintained by
hand in ast.h.erb with only 6 members, while 14 annotation structs
existed and were all cast to this union pointer in parser.c. This
drift went unnoticed because downstream code only touches `.base`
and never instantiates the union as a value.

Generate the union members from the annotation entries in config.yml
so future additions stay in sync automatically.

As a side benefit, ruby-rbs-sys/build.rs can now allowlist the union
type alone and rely on bindgen's transitive allowlisting to pull in
every `rbs_ast_ruby_annotations_*_t` member, replacing the
hand-maintained list of 13 individual allowlist entries (which had
itself drifted by missing module_self_annotation_t).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ksss

include/rbs/ast.h

@@ -941,12 +941,20 @@ typedef struct rbs_types_variable {
 
 typedef union rbs_ast_ruby_annotations {
     rbs_node_t base;
+    rbs_ast_ruby_annotations_block_param_type_annotation_t block_param_type_annotation;
+    rbs_ast_ruby_annotations_class_alias_annotation_t class_alias_annotation;
     rbs_ast_ruby_annotations_colon_method_type_annotation_t colon_method_type_annotation;
+    rbs_ast_ruby_annotations_double_splat_param_type_annotation_t double_splat_param_type_annotation;
+    rbs_ast_ruby_annotations_instance_variable_annotation_t instance_variable_annotation;
     rbs_ast_ruby_annotations_method_types_annotation_t method_types_annotation;
+    rbs_ast_ruby_annotations_module_alias_annotation_t module_alias_annotation;
+    rbs_ast_ruby_annotations_module_self_annotation_t module_self_annotation;
     rbs_ast_ruby_annotations_node_type_assertion_t node_type_assertion;
+    rbs_ast_ruby_annotations_param_type_annotation_t param_type_annotation;
     rbs_ast_ruby_annotations_return_type_annotation_t return_type_annotation;
     rbs_ast_ruby_annotations_skip_annotation_t skip_annotation;
-    rbs_ast_ruby_annotations_param_type_annotation_t param_type_annotation;
+    rbs_ast_ruby_annotations_splat_param_type_annotation_t splat_param_type_annotation;
+    rbs_ast_ruby_annotations_type_application_annotation_t type_application_annotation;
 } rbs_ast_ruby_annotations_t;
 
 /// `rbs_ast_symbol_t` models user-defined identifiers like class names, method names, etc.

rust/ruby-rbs-sys/build.rs

@@ -103,19 +103,9 @@ fn generate_bindings(include_path: &Path) -> Result<bindgen::Bindings, Box<dyn E
         .allowlist_type("rbs_ast_members_prepend_t")
         .allowlist_type("rbs_ast_members_private_t")
         .allowlist_type("rbs_ast_members_public_t")
-        .allowlist_type("rbs_ast_ruby_annotations_class_alias_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_colon_method_type_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_instance_variable_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_method_types_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_module_alias_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_node_type_assertion_t")
-        .allowlist_type("rbs_ast_ruby_annotations_return_type_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_skip_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_type_application_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_block_param_type_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_param_type_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_splat_param_type_annotation_t")
-        .allowlist_type("rbs_ast_ruby_annotations_double_splat_param_type_annotation_t")
+        // The union pulls in every `rbs_ast_ruby_annotations_*_t` member transitively,
+        // so individual annotation structs do not need separate allowlist entries.
+        .allowlist_type("rbs_ast_ruby_annotations_t")
         .allowlist_type("rbs_ast_string_t")
         .allowlist_type("rbs_ast_symbol_t")
         .allowlist_type("rbs_ast_type_param_t")

templates/include/rbs/ast.h.erb

@@ -108,12 +108,9 @@ typedef struct <%= node.c_name %> {
 <%- end -%>
 typedef union rbs_ast_ruby_annotations {
     rbs_node_t base;
-    rbs_ast_ruby_annotations_colon_method_type_annotation_t colon_method_type_annotation;
-    rbs_ast_ruby_annotations_method_types_annotation_t method_types_annotation;
-    rbs_ast_ruby_annotations_node_type_assertion_t node_type_assertion;
-    rbs_ast_ruby_annotations_return_type_annotation_t return_type_annotation;
-    rbs_ast_ruby_annotations_skip_annotation_t skip_annotation;
-    rbs_ast_ruby_annotations_param_type_annotation_t param_type_annotation;
+<%- annotation_nodes.each do |node| -%>
+    <%= node.c_type_name %> <%= node.c_name.delete_prefix("rbs_ast_ruby_annotations_") %>;
+<%- end -%>
 } rbs_ast_ruby_annotations_t;
 
 /// `rbs_ast_symbol_t` models user-defined identifiers like class names, method names, etc.

templates/template.rb

@@ -385,9 +385,16 @@ def locals
           Node.new(node, fields, locations, constructor_params)
         end
 
+        sorted_nodes = nodes.sort_by { _1.descr.ruby_full_name }
+
+        annotation_nodes = sorted_nodes
+          .select { _1.descr.ruby_full_name.start_with?("RBS::AST::Ruby::Annotations::") }
+          .sort_by(&:c_name)
+
         {
-          nodes: nodes.sort_by { _1.descr.ruby_full_name },
-          enums: enum_desc
+          nodes: sorted_nodes,
+          enums: enum_desc,
+          annotation_nodes: annotation_nodes,
         }
       end
     end