From 65aaceb2a022f886a8f735ac962da5a5923f6395 Mon Sep 17 00:00:00 2001
From: David Snopek <dsnopek@gmail.com>
Date: Thu, 6 Jul 2023 21:16:27 -0500
Subject: [PATCH] Add static methods to `ClassDB` for the methods bound to the
 `ClassDB` singleton

---
 binding_generator.py                | 58 +++++++++++++++++++++++++----
 include/godot_cpp/core/class_db.hpp |  4 ++
 2 files changed, 54 insertions(+), 8 deletions(-)

diff --git a/binding_generator.py b/binding_generator.py
index d04c6987b0..c709eda993 100644
--- a/binding_generator.py
+++ b/binding_generator.py
@@ -97,9 +97,9 @@ def get_file_list(api_filepath, output_dir, headers=False, sources=False):
             files.append(str(source_filename.as_posix()))
 
     for engine_class in api["classes"]:
-        # TODO: Properly setup this singleton since it conflicts with ClassDB in the bindings.
+        # Generate code for the ClassDB singleton under a different name.
         if engine_class["name"] == "ClassDB":
-            continue
+            engine_class["name"] = "ClassDBSingleton"
         header_filename = include_gen_folder / "classes" / (camel_to_snake(engine_class["name"]) + ".hpp")
         source_filename = source_gen_folder / "classes" / (camel_to_snake(engine_class["name"]) + ".cpp")
         if headers:
@@ -1036,21 +1036,21 @@ def generate_engine_classes_bindings(api, output_dir, use_template_get_node):
 
     # First create map of classes and singletons.
     for class_api in api["classes"]:
-        # TODO: Properly setup this singleton since it conflicts with ClassDB in the bindings.
+        # Generate code for the ClassDB singleton under a different name.
         if class_api["name"] == "ClassDB":
-            continue
+            class_api["name"] = "ClassDBSingleton"
         engine_classes[class_api["name"]] = class_api["is_refcounted"]
     for native_struct in api["native_structures"]:
         engine_classes[native_struct["name"]] = False
         native_structures.append(native_struct["name"])
 
     for singleton in api["singletons"]:
+        # Generate code for the ClassDB singleton under a different name.
+        if singleton["name"] == "ClassDB":
+            singleton["name"] = "ClassDBSingleton"
         singletons.append(singleton["name"])
 
     for class_api in api["classes"]:
-        # TODO: Properly setup this singleton since it conflicts with ClassDB in the bindings.
-        if class_api["name"] == "ClassDB":
-            continue
         # Check used classes for header include.
         used_classes = set()
         fully_used_classes = set()
@@ -1242,7 +1242,7 @@ def generate_engine_class_header(class_api, used_classes, fully_used_classes, us
     if len(fully_used_classes) > 0:
         result.append("")
 
-    if class_name != "Object":
+    if class_name != "Object" and class_name != "ClassDBSingleton":
         result.append("#include <godot_cpp/core/class_db.hpp>")
         result.append("")
         result.append("#include <type_traits>")
@@ -1421,6 +1421,47 @@ def generate_engine_class_header(class_api, used_classes, fully_used_classes, us
                 result.append(f'VARIANT_ENUM_CAST({class_name}::{enum_api["name"]});')
         result.append("")
 
+    if class_name == "ClassDBSingleton":
+        result.append("#define CLASSDB_SINGLETON_FORWARD_METHODS \\")
+        for method in class_api["methods"]:
+            # ClassDBSingleton shouldn't have any static or vararg methods, but if some appear later, lets skip them.
+            if vararg:
+                continue
+            if "is_static" in method and method["is_static"]:
+                continue
+
+            method_signature = "\tstatic "
+            if "return_type" in method:
+                method_signature += f'{correct_type(method["return_type"])} '
+            else:
+                method_signature += "void "
+
+            method_signature += f'{method["name"]}('
+
+            method_arguments = []
+            if "arguments" in method:
+                method_arguments = method["arguments"]
+
+            method_signature += make_function_parameters(
+                method_arguments, include_default=True, for_builtin=True, is_vararg=False
+            )
+
+            method_signature += ") { \\"
+
+            result.append(method_signature)
+
+            method_body = "\t\t"
+            if "return_type" in method:
+                method_body += "return "
+            method_body += f'ClassDBSingleton::get_singleton()->{method["name"]}('
+            method_body += ", ".join(map(lambda x: escape_identifier(x["name"]), method_arguments))
+            method_body += "); \\"
+
+            result.append(method_body)
+            result.append("\t} \\")
+        result.append("\t;")
+        result.append("")
+
     result.append(f"#endif // ! {header_guard}")
 
     return "\n".join(result)
@@ -2285,6 +2326,7 @@ def escape_identifier(id):
         "operator": "_operator",
         "typeof": "type_of",
         "typename": "type_name",
+        "enum": "_enum",
     }
     if id in cpp_keywords_map:
         return cpp_keywords_map[id]
diff --git a/include/godot_cpp/core/class_db.hpp b/include/godot_cpp/core/class_db.hpp
index b1625bf241..26dfb7eb49 100644
--- a/include/godot_cpp/core/class_db.hpp
+++ b/include/godot_cpp/core/class_db.hpp
@@ -38,6 +38,8 @@
 #include <godot_cpp/core/method_bind.hpp>
 #include <godot_cpp/core/object.hpp>
 
+#include <godot_cpp/classes/class_db_singleton.hpp>
+
 #include <list>
 #include <set>
 #include <string>
@@ -146,6 +148,8 @@ class ClassDB {
 
 	static void initialize(GDExtensionInitializationLevel p_level);
 	static void deinitialize(GDExtensionInitializationLevel p_level);
+
+	CLASSDB_SINGLETON_FORWARD_METHODS;
 };
 
 #define BIND_CONSTANT(m_constant) \