Merge 134450c0ed into 5fcc43e54d

Allow GDExtensions to register virtual methods and call them on scripts (godot-cpp support)

.github/workflows/ci.yml

@@ -155,8 +155,8 @@ jobs:
         uses: dsnopek/action-download-artifact@1322f74e2dac9feed2ee76a32d9ae1ca3b4cf4e9
         if: ${{ matrix.run-tests }}
         with:
-          repo: godotengine/godot
+          repo: AThousandShips/godot
-          branch: master
+          branch: the_angry_count
           event: push
           workflow: linux_builds.yml
           workflow_conclusion: success

binding_generator.py

@@ -70,6 +70,136 @@ def generate_wrappers(target):
         f.write(txt)
 
 
+def generate_virtual_version(argcount, const=False, returns=False):
+    s = """#define GDVIRTUAL$VER($RET m_name $ARG)\\
+	StringName _gdvirtual_##m_name##_sn = #m_name;\\
+	template <bool required>\\
+	_FORCE_INLINE_ bool _gdvirtual_##m_name##_call($CALLARGS) $CONST {\\
+		if (::godot::internal::gdextension_interface_object_has_script_method(_owner, &_gdvirtual_##m_name##_sn)) { \\
+			GDExtensionCallError ce;\\
+			$CALLSIARGS\\
+			$CALLSIBEGIN::godot::internal::gdextension_interface_object_call_script_method(_owner, &_gdvirtual_##m_name##_sn, $CALLSIARGPASS, $CALLSIRETPASS, &ce);\\
+			if (ce.error == GDEXTENSION_CALL_OK) {\\
+				$CALLSIRET\\
+				return true;\\
+			}\\
+		}\\
+		if (required) {\\
+			ERR_PRINT_ONCE("Required virtual method " + get_class() + "::" + #m_name + " must be overridden before calling.");\\
+			$RVOID\\
+		}\\
+		return false;\\
+	}\\
+	_FORCE_INLINE_ bool _gdvirtual_##m_name##_overridden() const {\\
+		return godot::internal::gdextension_interface_object_has_script_method(_owner, &_gdvirtual_##m_name##_sn); \\
+	}\\
+	_FORCE_INLINE_ static MethodInfo _gdvirtual_##m_name##_get_method_info() {\\
+		MethodInfo method_info;\\
+		method_info.name = #m_name;\\
+		method_info.flags = $METHOD_FLAGS;\\
+		$FILL_METHOD_INFO\\
+		return method_info;\\
+	}
+
+"""
+
+    sproto = str(argcount)
+    method_info = ""
+    if returns:
+        sproto += "R"
+        s = s.replace("$RET", "m_ret,")
+        s = s.replace("$RVOID", "(void)r_ret;")  # If required, may lead to uninitialized errors
+        method_info += "method_info.return_val = GetTypeInfo<m_ret>::get_class_info();\\\n"
+        method_info += "\t\tmethod_info.return_val_metadata = GetTypeInfo<m_ret>::METADATA;"
+    else:
+        s = s.replace("$RET ", "")
+        s = s.replace("\t\t\t$RVOID\\\n", "")
+
+    if const:
+        sproto += "C"
+        s = s.replace("$CONST", "const")
+        s = s.replace("$METHOD_FLAGS", "METHOD_FLAG_VIRTUAL | METHOD_FLAG_CONST")
+    else:
+        s = s.replace("$CONST ", "")
+        s = s.replace("$METHOD_FLAGS", "METHOD_FLAG_VIRTUAL")
+
+    s = s.replace("$VER", sproto)
+    argtext = ""
+    callargtext = ""
+    callsiargs = ""
+    callsiargptrs = ""
+    if argcount > 0:
+        argtext += ", "
+        callsiargs = f"Variant vargs[{argcount}] = {{ "
+        callsiargptrs = f"\t\t\tconst Variant *vargptrs[{argcount}] = {{ "
+    for i in range(argcount):
+        if i > 0:
+            argtext += ", "
+            callargtext += ", "
+            callsiargs += ", "
+            callsiargptrs += ", "
+        argtext += f"m_type{i + 1}"
+        callargtext += f"m_type{i + 1} arg{i + 1}"
+        callsiargs += f"Variant(arg{i + 1})"
+        callsiargptrs += f"&vargs[{i}]"
+        if method_info:
+            method_info += "\\\n\t\t"
+        method_info += f"method_info.arguments.push_back(GetTypeInfo<m_type{i + 1}>::get_class_info());\\\n"
+        method_info += f"\t\tmethod_info.arguments_metadata.push_back(GetTypeInfo<m_type{i + 1}>::METADATA);"
+
+    if argcount:
+        callsiargs += " };\\\n"
+        callsiargptrs += " };"
+        s = s.replace("$CALLSIARGS", callsiargs + callsiargptrs)
+        s = s.replace("$CALLSIARGPASS", f"(const GDExtensionConstVariantPtr *)vargptrs, {argcount}")
+    else:
+        s = s.replace("\t\t\t$CALLSIARGS\\\n", "")
+        s = s.replace("$CALLSIARGPASS", "nullptr, 0")
+
+    if returns:
+        if argcount > 0:
+            callargtext += ", "
+        callargtext += "m_ret &r_ret"
+        s = s.replace("$CALLSIBEGIN", "Variant ret;\\\n\t\t\t")
+        s = s.replace("$CALLSIRETPASS", "&ret")
+        s = s.replace("$CALLSIRET", "r_ret = VariantCaster<m_ret>::cast(ret);")
+    else:
+        s = s.replace("$CALLSIBEGIN", "")
+        s = s.replace("$CALLSIRETPASS", "nullptr")
+        s = s.replace("\t\t\t\t$CALLSIRET\\\n", "")
+
+    s = s.replace(" $ARG", argtext)
+    s = s.replace("$CALLARGS", callargtext)
+    if method_info:
+        s = s.replace("$FILL_METHOD_INFO", method_info)
+    else:
+        s = s.replace("\t\t$FILL_METHOD_INFO\\\n", method_info)
+
+    return s
+
+
+def generate_virtuals(target):
+    max_versions = 12
+
+    txt = """/* THIS FILE IS GENERATED DO NOT EDIT */
+#ifndef GDEXTENSION_GDVIRTUAL_GEN_H
+#define GDEXTENSION_GDVIRTUAL_GEN_H
+
+"""
+
+    for i in range(max_versions + 1):
+        txt += f"/* {i} Arguments */\n\n"
+        txt += generate_virtual_version(i, False, False)
+        txt += generate_virtual_version(i, False, True)
+        txt += generate_virtual_version(i, True, False)
+        txt += generate_virtual_version(i, True, True)
+
+    txt += "#endif // GDEXTENSION_GDVIRTUAL_GEN_H\n"
+
+    with open(target, "w", encoding="utf-8") as f:
+        f.write(txt)
+
+
 def get_file_list(api_filepath, output_dir, headers=False, sources=False):
     api = {}
     files = []
@@ -81,6 +211,7 @@ def get_file_list(api_filepath, output_dir, headers=False, sources=False):
     source_gen_folder = Path(output_dir) / "gen" / "src"
 
     files.append(str((core_gen_folder / "ext_wrappers.gen.inc").as_posix()))
+    files.append(str((core_gen_folder / "gdvirtual.gen.inc").as_posix()))
 
     for builtin_class in api["builtin_classes"]:
         if is_pod_type(builtin_class["name"]):
@@ -204,6 +335,7 @@ def generate_builtin_bindings(api, output_dir, build_config):
     source_gen_folder.mkdir(parents=True, exist_ok=True)
 
     generate_wrappers(core_gen_folder / "ext_wrappers.gen.inc")
+    generate_virtuals(core_gen_folder / "gdvirtual.gen.inc")
 
     # Store types beforehand.
     for builtin_api in api["builtin_classes"]:
@@ -964,8 +1096,19 @@ def generate_builtin_class_source(builtin_api, size, used_classes, fully_used_cl
             result.append(method_signature + "{")
 
             method_call = "\t"
+            is_ref = False
+
             if "return_type" in method:
-                method_call += f'return internal::_call_builtin_method_ptr_ret<{correct_type(method["return_type"])}>('
+                return_type = method["return_type"]
+                if is_enum(return_type):
+                    method_call += f"return ({get_gdextension_type(correct_type(return_type))})internal::_call_builtin_method_ptr_ret<int64_t>("
+                elif is_pod_type(return_type) or is_variant(return_type):
+                    method_call += f"return internal::_call_builtin_method_ptr_ret<{get_gdextension_type(correct_type(return_type))}>("
+                elif is_refcounted(return_type):
+                    method_call += f"return Ref<{return_type}>::_gde_internal_constructor(internal::_call_builtin_method_ptr_ret_obj<{return_type}>("
+                    is_ref = True
+                else:
+                    method_call += f"return internal::_call_builtin_method_ptr_ret_obj<{return_type}>("
             else:
                 method_call += "internal::_call_builtin_method_ptr_no_ret("
             method_call += f'_method_bindings.method_{method["name"]}, '
@@ -986,6 +1129,9 @@ def generate_builtin_class_source(builtin_api, size, used_classes, fully_used_cl
                     result += encode
                     arguments.append(arg_name)
                 method_call += ", ".join(arguments)
+
+            if is_ref:
+                method_call += ")"  # Close Ref<> constructor.
             method_call += ");"
 
             result.append(method_call)

gdextension/gdextension_interface.h

@@ -364,13 +364,18 @@ typedef struct {
 	GDExtensionClassMethodPtrCall ptrcall_func;
 	uint32_t method_flags; // Bitfield of `GDExtensionClassMethodFlags`.
 
-	/* If `has_return_value` is false, `return_value_info` and `return_value_metadata` are ignored. */
+	/* If `has_return_value` is false, `return_value_info` and `return_value_metadata` are ignored.
+	 *
+	 * @todo Consider dropping `has_return_value` and making the other two properties match `GDExtensionMethodInfo` and `GDExtensionClassVirtualMethod` for consistency in future version of this struct.
+	 */
 	GDExtensionBool has_return_value;
 	GDExtensionPropertyInfo *return_value_info;
 	GDExtensionClassMethodArgumentMetadata return_value_metadata;
 
 	/* Arguments: `arguments_info` and `arguments_metadata` are array of size `argument_count`.
 	 * Name and hint information for the argument can be omitted in release builds. Class name should always be present if it applies.
+	 *
+	 * @todo Consider renaming `arguments_info` to `arguments` for consistency in future version of this struct.
 	 */
 	uint32_t argument_count;
 	GDExtensionPropertyInfo *arguments_info;
@@ -381,6 +386,18 @@ typedef struct {
 	GDExtensionVariantPtr *default_arguments;
 } GDExtensionClassMethodInfo;
 
+typedef struct {
+	GDExtensionStringNamePtr name;
+	uint32_t method_flags; // Bitfield of `GDExtensionClassMethodFlags`.
+
+	GDExtensionPropertyInfo return_value;
+	GDExtensionClassMethodArgumentMetadata return_value_metadata;
+
+	uint32_t argument_count;
+	GDExtensionPropertyInfo *arguments;
+	GDExtensionClassMethodArgumentMetadata *arguments_metadata;
+} GDExtensionClassVirtualMethodInfo;
+
 typedef void (*GDExtensionCallableCustomCall)(void *callable_userdata, const GDExtensionConstVariantPtr *p_args, GDExtensionInt p_argument_count, GDExtensionVariantPtr r_return, GDExtensionCallError *r_error);
 typedef GDExtensionBool (*GDExtensionCallableCustomIsValid)(void *callable_userdata);
 typedef void (*GDExtensionCallableCustomFree)(void *callable_userdata);
@@ -391,6 +408,8 @@ typedef GDExtensionBool (*GDExtensionCallableCustomLessThan)(void *callable_user
 
 typedef void (*GDExtensionCallableCustomToString)(void *callable_userdata, GDExtensionBool *r_is_valid, GDExtensionStringPtr r_out);
 
+typedef GDExtensionInt (*GDExtensionCallableCustomGetArgumentCount)(void *callable_userdata, GDExtensionBool *r_is_valid);
+
 typedef struct {
 	/* Only `call_func` and `token` are strictly required, however, `object_id` should be passed if its not a static method.
 	 *
@@ -420,7 +439,40 @@ typedef struct {
 	GDExtensionCallableCustomLessThan less_than_func;
 
 	GDExtensionCallableCustomToString to_string_func;
-} GDExtensionCallableCustomInfo;
+} GDExtensionCallableCustomInfo; // Deprecated. Use GDExtensionCallableCustomInfo2 instead.
+
+typedef struct {
+	/* Only `call_func` and `token` are strictly required, however, `object_id` should be passed if its not a static method.
+	 *
+	 * `token` should point to an address that uniquely identifies the GDExtension (for example, the
+	 * `GDExtensionClassLibraryPtr` passed to the entry symbol function.
+	 *
+	 * `hash_func`, `equal_func`, and `less_than_func` are optional. If not provided both `call_func` and
+	 * `callable_userdata` together are used as the identity of the callable for hashing and comparison purposes.
+	 *
+	 * The hash returned by `hash_func` is cached, `hash_func` will not be called more than once per callable.
+	 *
+	 * `is_valid_func` is necessary if the validity of the callable can change before destruction.
+	 *
+	 * `free_func` is necessary if `callable_userdata` needs to be cleaned up when the callable is freed.
+	 */
+	void *callable_userdata;
+	void *token;
+
+	GDObjectInstanceID object_id;
+
+	GDExtensionCallableCustomCall call_func;
+	GDExtensionCallableCustomIsValid is_valid_func;
+	GDExtensionCallableCustomFree free_func;
+
+	GDExtensionCallableCustomHash hash_func;
+	GDExtensionCallableCustomEqual equal_func;
+	GDExtensionCallableCustomLessThan less_than_func;
+
+	GDExtensionCallableCustomToString to_string_func;
+
+	GDExtensionCallableCustomGetArgumentCount get_argument_count_func;
+} GDExtensionCallableCustomInfo2;
 
 /* SCRIPT INSTANCE EXTENSION */
 
@@ -447,6 +499,8 @@ typedef void (*GDExtensionScriptInstanceFreeMethodList)(GDExtensionScriptInstanc
 
 typedef GDExtensionBool (*GDExtensionScriptInstanceHasMethod)(GDExtensionScriptInstanceDataPtr p_instance, GDExtensionConstStringNamePtr p_name);
 
+typedef GDExtensionInt (*GDExtensionScriptInstanceGetMethodArgumentCount)(GDExtensionScriptInstanceDataPtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionBool *r_is_valid);
+
 typedef void (*GDExtensionScriptInstanceCall)(GDExtensionScriptInstanceDataPtr p_self, GDExtensionConstStringNamePtr p_method, const GDExtensionConstVariantPtr *p_args, GDExtensionInt p_argument_count, GDExtensionVariantPtr r_return, GDExtensionCallError *r_error);
 typedef void (*GDExtensionScriptInstanceNotification)(GDExtensionScriptInstanceDataPtr p_instance, int32_t p_what); // Deprecated. Use GDExtensionScriptInstanceNotification2 instead.
 typedef void (*GDExtensionScriptInstanceNotification2)(GDExtensionScriptInstanceDataPtr p_instance, int32_t p_what, GDExtensionBool p_reversed);
@@ -503,7 +557,7 @@ typedef struct {
 
 	GDExtensionScriptInstanceFree free_func;
 
-} GDExtensionScriptInstanceInfo; // Deprecated. Use GDExtensionScriptInstanceInfo2 instead.
+} GDExtensionScriptInstanceInfo; // Deprecated. Use GDExtensionScriptInstanceInfo3 instead.
 
 typedef struct {
 	GDExtensionScriptInstanceSet set_func;
@@ -544,7 +598,50 @@ typedef struct {
 
 	GDExtensionScriptInstanceFree free_func;
 
-} GDExtensionScriptInstanceInfo2;
+} GDExtensionScriptInstanceInfo2; // Deprecated. Use GDExtensionScriptInstanceInfo3 instead.
+
+typedef struct {
+	GDExtensionScriptInstanceSet set_func;
+	GDExtensionScriptInstanceGet get_func;
+	GDExtensionScriptInstanceGetPropertyList get_property_list_func;
+	GDExtensionScriptInstanceFreePropertyList free_property_list_func;
+	GDExtensionScriptInstanceGetClassCategory get_class_category_func; // Optional. Set to NULL for the default behavior.
+
+	GDExtensionScriptInstancePropertyCanRevert property_can_revert_func;
+	GDExtensionScriptInstancePropertyGetRevert property_get_revert_func;
+
+	GDExtensionScriptInstanceGetOwner get_owner_func;
+	GDExtensionScriptInstanceGetPropertyState get_property_state_func;
+
+	GDExtensionScriptInstanceGetMethodList get_method_list_func;
+	GDExtensionScriptInstanceFreeMethodList free_method_list_func;
+	GDExtensionScriptInstanceGetPropertyType get_property_type_func;
+	GDExtensionScriptInstanceValidateProperty validate_property_func;
+
+	GDExtensionScriptInstanceHasMethod has_method_func;
+
+	GDExtensionScriptInstanceGetMethodArgumentCount get_method_argument_count_func;
+
+	GDExtensionScriptInstanceCall call_func;
+	GDExtensionScriptInstanceNotification2 notification_func;
+
+	GDExtensionScriptInstanceToString to_string_func;
+
+	GDExtensionScriptInstanceRefCountIncremented refcount_incremented_func;
+	GDExtensionScriptInstanceRefCountDecremented refcount_decremented_func;
+
+	GDExtensionScriptInstanceGetScript get_script_func;
+
+	GDExtensionScriptInstanceIsPlaceholder is_placeholder_func;
+
+	GDExtensionScriptInstanceSet set_fallback_func;
+	GDExtensionScriptInstanceGet get_fallback_func;
+
+	GDExtensionScriptInstanceGetLanguage get_language_func;
+
+	GDExtensionScriptInstanceFree free_func;
+
+} GDExtensionScriptInstanceInfo3;
 
 /* INITIALIZATION */
 
@@ -2268,6 +2365,34 @@ typedef GDExtensionObjectPtr (*GDExtensionInterfaceObjectGetInstanceFromId)(GDOb
  */
 typedef GDObjectInstanceID (*GDExtensionInterfaceObjectGetInstanceId)(GDExtensionConstObjectPtr p_object);
 
+/**
+ * @name object_has_script_method
+ * @since 4.3
+ *
+ * Checks if this object has a script with the given method.
+ *
+ * @param p_object A pointer to the Object.
+ * @param p_method A pointer to a StringName identifying the method.
+ *
+ * @returns true if the object has a script and that script has a method with the given name. Returns false if the object has no script.
+ */
+typedef GDExtensionBool (*GDExtensionInterfaceObjectHasScriptMethod)(GDExtensionConstObjectPtr p_object, GDExtensionConstStringNamePtr p_method);
+
+/**
+ * @name object_call_script_method
+ * @since 4.3
+ *
+ * Call the given script method on this object.
+ *
+ * @param p_object A pointer to the Object.
+ * @param p_method A pointer to a StringName identifying the method.
+ * @param p_args A pointer to a C array of Variant.
+ * @param p_argument_count The number of arguments.
+ * @param r_return A pointer a Variant which will be assigned the return value.
+ * @param r_error A pointer the structure which will hold error information.
+ */
+typedef void (*GDExtensionInterfaceObjectCallScriptMethod)(GDExtensionObjectPtr p_object, GDExtensionConstStringNamePtr p_method, const GDExtensionConstVariantPtr *p_args, GDExtensionInt p_argument_count, GDExtensionUninitializedVariantPtr r_return, GDExtensionCallError *r_error);
+
 /* INTERFACE: Reference */
 
 /**
@@ -2298,7 +2423,7 @@ typedef void (*GDExtensionInterfaceRefSetObject)(GDExtensionRefPtr p_ref, GDExte
 /**
  * @name script_instance_create
  * @since 4.1
- * @deprecated in Godot 4.2. Use `script_instance_create2` instead.
+ * @deprecated in Godot 4.2. Use `script_instance_create3` instead.
  *
  * Creates a script instance that contains the given info and instance data.
  *
@@ -2312,6 +2437,7 @@ typedef GDExtensionScriptInstancePtr (*GDExtensionInterfaceScriptInstanceCreate)
 /**
  * @name script_instance_create2
  * @since 4.2
+ * @deprecated in Godot 4.3. Use `script_instance_create3` instead.
  *
  * Creates a script instance that contains the given info and instance data.
  *
@@ -2322,6 +2448,19 @@ typedef GDExtensionScriptInstancePtr (*GDExtensionInterfaceScriptInstanceCreate)
  */
 typedef GDExtensionScriptInstancePtr (*GDExtensionInterfaceScriptInstanceCreate2)(const GDExtensionScriptInstanceInfo2 *p_info, GDExtensionScriptInstanceDataPtr p_instance_data);
 
+/**
+ * @name script_instance_create3
+ * @since 4.3
+ *
+ * Creates a script instance that contains the given info and instance data.
+ *
+ * @param p_info A pointer to a GDExtensionScriptInstanceInfo3 struct.
+ * @param p_instance_data A pointer to a data representing the script instance in the GDExtension. This will be passed to all the function pointers on p_info.
+ *
+ * @return A pointer to a ScriptInstanceExtension object.
+ */
+typedef GDExtensionScriptInstancePtr (*GDExtensionInterfaceScriptInstanceCreate3)(const GDExtensionScriptInstanceInfo3 *p_info, GDExtensionScriptInstanceDataPtr p_instance_data);
+
 /**
  * @name placeholder_script_instance_create
  * @since 4.2
@@ -2371,6 +2510,7 @@ typedef GDExtensionScriptInstanceDataPtr (*GDExtensionInterfaceObjectGetScriptIn
 /**
  * @name callable_custom_create
  * @since 4.2
+ * @deprecated in Godot 4.3. Use `callable_custom_create2` instead.
  *
  * Creates a custom Callable object from a function pointer.
  *
@@ -2381,6 +2521,19 @@ typedef GDExtensionScriptInstanceDataPtr (*GDExtensionInterfaceObjectGetScriptIn
  */
 typedef void (*GDExtensionInterfaceCallableCustomCreate)(GDExtensionUninitializedTypePtr r_callable, GDExtensionCallableCustomInfo *p_callable_custom_info);
 
+/**
+ * @name callable_custom_create2
+ * @since 4.3
+ *
+ * Creates a custom Callable object from a function pointer.
+ *
+ * Provided struct can be safely freed once the function returns.
+ *
+ * @param r_callable A pointer that will receive the new Callable.
+ * @param p_callable_custom_info The info required to construct a Callable.
+ */
+typedef void (*GDExtensionInterfaceCallableCustomCreate2)(GDExtensionUninitializedTypePtr r_callable, GDExtensionCallableCustomInfo2 *p_callable_custom_info);
+
 /**
  * @name callable_custom_get_userdata
  * @since 4.2
@@ -2483,6 +2636,20 @@ typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClass2)(GDExtensionCl
  */
 typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClassMethod)(GDExtensionClassLibraryPtr p_library, GDExtensionConstStringNamePtr p_class_name, const GDExtensionClassMethodInfo *p_method_info);
 
+/**
+ * @name classdb_register_extension_class_virtual_method
+ * @since 4.3
+ *
+ * Registers a virtual method on an extension class in ClassDB, that can be implemented by scripts or other extensions.
+ *
+ * Provided struct can be safely freed once the function returns.
+ *
+ * @param p_library A pointer the library received by the GDExtension's entry point function.
+ * @param p_class_name A pointer to a StringName with the class name.
+ * @param p_method_info A pointer to a GDExtensionClassMethodInfo struct.
+ */
+typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClassVirtualMethod)(GDExtensionClassLibraryPtr p_library, GDExtensionConstStringNamePtr p_class_name, const GDExtensionClassVirtualMethodInfo *p_method_info);
+
 /**
  * @name classdb_register_extension_class_integer_constant
  * @since 4.1

include/godot_cpp/classes/wrapped.hpp

@@ -36,6 +36,7 @@
 #include <godot_cpp/core/property_info.hpp>
 
 #include <godot_cpp/templates/list.hpp>
+#include <godot_cpp/templates/vector.hpp>
 
 #include <godot_cpp/godot.hpp>
 
@@ -107,6 +108,26 @@ public:
 	GodotObject *_owner = nullptr;
 };
 
+_FORCE_INLINE_ void snarray_add_str(Vector<StringName> &arr) {
+}
+
+_FORCE_INLINE_ void snarray_add_str(Vector<StringName> &arr, const StringName &p_str) {
+	arr.push_back(p_str);
+}
+
+template <class... P>
+_FORCE_INLINE_ void snarray_add_str(Vector<StringName> &arr, const StringName &p_str, P... p_args) {
+	arr.push_back(p_str);
+	snarray_add_str(arr, p_args...);
+}
+
+template <class... P>
+_FORCE_INLINE_ Vector<StringName> snarray(P... p_args) {
+	Vector<StringName> arr;
+	snarray_add_str(arr, p_args...);
+	return arr;
+}
+
 namespace internal {
 
 GDExtensionPropertyInfo *create_c_property_list(const ::godot::List<::godot::PropertyInfo> &plist_cpp, uint32_t *r_size);
@@ -445,4 +466,14 @@ private:
 // Don't use this for your classes, use GDCLASS() instead.
 #define GDEXTENSION_CLASS(m_class, m_inherits) GDEXTENSION_CLASS_ALIAS(m_class, m_class, m_inherits)
 
+#define GDVIRTUAL_CALL(m_name, ...) _gdvirtual_##m_name##_call<false>(__VA_ARGS__)
+#define GDVIRTUAL_CALL_PTR(m_obj, m_name, ...) m_obj->_gdvirtual_##m_name##_call<false>(__VA_ARGS__)
+
+#define GDVIRTUAL_REQUIRED_CALL(m_name, ...) _gdvirtual_##m_name##_call<true>(__VA_ARGS__)
+#define GDVIRTUAL_REQUIRED_CALL_PTR(m_obj, m_name, ...) m_obj->_gdvirtual_##m_name##_call<true>(__VA_ARGS__)
+
+#define GDVIRTUAL_BIND(m_name, ...) ::godot::ClassDB::add_virtual_method(get_class_static(), _gdvirtual_##m_name##_get_method_info(), ::godot::snarray(__VA_ARGS__));
+#define GDVIRTUAL_IS_OVERRIDDEN(m_name) _gdvirtual_##m_name##_overridden()
+#define GDVIRTUAL_IS_OVERRIDDEN_PTR(m_obj, m_name) m_obj->_gdvirtual_##m_name##_overridden()
+
 #endif // GODOT_WRAPPED_HPP

include/godot_cpp/core/builtin_ptrcall.hpp

@@ -32,6 +32,7 @@
 #define GODOT_BUILTIN_PTRCALL_HPP
 
 #include <gdextension_interface.h>
+#include <godot_cpp/core/object.hpp>
 
 #include <array>
 
@@ -39,6 +40,17 @@ namespace godot {
 
 namespace internal {
 
+template <class O, class... Args>
+O *_call_builtin_method_ptr_ret_obj(const GDExtensionPtrBuiltInMethod method, GDExtensionTypePtr base, const Args &...args) {
+	GodotObject *ret = nullptr;
+	std::array<GDExtensionConstTypePtr, sizeof...(Args)> call_args = { { (GDExtensionConstTypePtr)args... } };
+	method(base, call_args.data(), &ret, sizeof...(Args));
+	if (ret == nullptr) {
+		return nullptr;
+	}
+	return reinterpret_cast<O *>(internal::get_object_instance_binding(ret));
+}
+
 template <class... Args>
 void _call_builtin_constructor(const GDExtensionPtrConstructor constructor, GDExtensionTypePtr base, Args... args) {
 	std::array<GDExtensionConstTypePtr, sizeof...(Args)> call_args = { { (GDExtensionConstTypePtr)args... } };

include/godot_cpp/core/class_db.hpp

@@ -165,7 +165,10 @@ public:
 	static void add_property(const StringName &p_class, const PropertyInfo &p_pinfo, const StringName &p_setter, const StringName &p_getter, int p_index = -1);
 	static void add_signal(const StringName &p_class, const MethodInfo &p_signal);
 	static void bind_integer_constant(const StringName &p_class_name, const StringName &p_enum_name, const StringName &p_constant_name, GDExtensionInt p_constant_value, bool p_is_bitfield = false);
+	// Binds an implementation of a virtual method defined in Godot.
 	static void bind_virtual_method(const StringName &p_class, const StringName &p_method, GDExtensionClassCallVirtual p_call);
+	// Add a new virtual method that can be implemented by scripts.
+	static void add_virtual_method(const StringName &p_class, const MethodInfo &p_method, const Vector<StringName> &p_arg_names = Vector<StringName>());
 
 	static MethodBind *get_method(const StringName &p_class, const StringName &p_method);
 

include/godot_cpp/core/object.hpp

@@ -68,6 +68,8 @@ struct MethodInfo {
 	int id = 0;
 	std::vector<PropertyInfo> arguments;
 	std::vector<Variant> default_arguments;
+	GDExtensionClassMethodArgumentMetadata return_val_metadata;
+	std::vector<GDExtensionClassMethodArgumentMetadata> arguments_metadata;
 
 	inline bool operator==(const MethodInfo &p_method) const { return id == p_method.id; }
 	inline bool operator<(const MethodInfo &p_method) const { return id == p_method.id ? (name < p_method.name) : (id < p_method.id); }

include/godot_cpp/core/property_info.hpp

@@ -80,6 +80,17 @@ struct PropertyInfo {
 		p_info->usage = usage;
 		*(reinterpret_cast<StringName *>(p_info->class_name)) = class_name;
 	}
+
+	GDExtensionPropertyInfo _to_gdextension() const {
+		return {
+			(GDExtensionVariantType)type,
+			name._native_ptr(),
+			class_name._native_ptr(),
+			hint,
+			hint_string._native_ptr(),
+			usage,
+		};
+	}
 };
 
 } // namespace godot

include/godot_cpp/core/type_info.hpp

@@ -370,11 +370,14 @@ MAKE_TYPED_ARRAY_INFO(Rect2i, Variant::RECT2I)
 MAKE_TYPED_ARRAY_INFO(Vector3, Variant::VECTOR3)
 MAKE_TYPED_ARRAY_INFO(Vector3i, Variant::VECTOR3I)
 MAKE_TYPED_ARRAY_INFO(Transform2D, Variant::TRANSFORM2D)
+MAKE_TYPED_ARRAY_INFO(Vector4, Variant::VECTOR4)
+MAKE_TYPED_ARRAY_INFO(Vector4i, Variant::VECTOR4I)
 MAKE_TYPED_ARRAY_INFO(Plane, Variant::PLANE)
 MAKE_TYPED_ARRAY_INFO(Quaternion, Variant::QUATERNION)
 MAKE_TYPED_ARRAY_INFO(AABB, Variant::AABB)
 MAKE_TYPED_ARRAY_INFO(Basis, Variant::BASIS)
 MAKE_TYPED_ARRAY_INFO(Transform3D, Variant::TRANSFORM3D)
+MAKE_TYPED_ARRAY_INFO(Projection, Variant::PROJECTION)
 MAKE_TYPED_ARRAY_INFO(Color, Variant::COLOR)
 MAKE_TYPED_ARRAY_INFO(StringName, Variant::STRING_NAME)
 MAKE_TYPED_ARRAY_INFO(NodePath, Variant::NODE_PATH)
@@ -393,8 +396,11 @@ MAKE_TYPED_ARRAY_INFO(Vector<String>, Variant::PACKED_STRING_ARRAY)
 MAKE_TYPED_ARRAY_INFO(Vector<Vector2>, Variant::PACKED_VECTOR2_ARRAY)
 MAKE_TYPED_ARRAY_INFO(Vector<Vector3>, Variant::PACKED_VECTOR3_ARRAY)
 MAKE_TYPED_ARRAY_INFO(Vector<Color>, Variant::PACKED_COLOR_ARRAY)
+MAKE_TYPED_ARRAY_INFO(IPAddress, Variant::STRING)
 */
 
+#undef MAKE_TYPED_ARRAY_INFO
+
 #define CLASS_INFO(m_type) (GetTypeInfo<m_type *>::get_class_info())
 
 } // namespace godot

include/godot_cpp/godot.hpp

@@ -165,11 +165,13 @@ extern "C" GDExtensionInterfaceObjectGetClassName gdextension_interface_object_g
 extern "C" GDExtensionInterfaceObjectCastTo gdextension_interface_object_cast_to;
 extern "C" GDExtensionInterfaceObjectGetInstanceFromId gdextension_interface_object_get_instance_from_id;
 extern "C" GDExtensionInterfaceObjectGetInstanceId gdextension_interface_object_get_instance_id;
-extern "C" GDExtensionInterfaceCallableCustomCreate gdextension_interface_callable_custom_create;
+extern "C" GDExtensionInterfaceObjectHasScriptMethod gdextension_interface_object_has_script_method;
+extern "C" GDExtensionInterfaceObjectCallScriptMethod gdextension_interface_object_call_script_method;
+extern "C" GDExtensionInterfaceCallableCustomCreate2 gdextension_interface_callable_custom_create2;
 extern "C" GDExtensionInterfaceCallableCustomGetUserData gdextension_interface_callable_custom_get_userdata;
 extern "C" GDExtensionInterfaceRefGetObject gdextension_interface_ref_get_object;
 extern "C" GDExtensionInterfaceRefSetObject gdextension_interface_ref_set_object;
-extern "C" GDExtensionInterfaceScriptInstanceCreate2 gdextension_interface_script_instance_create2;
+extern "C" GDExtensionInterfaceScriptInstanceCreate3 gdextension_interface_script_instance_create3;
 extern "C" GDExtensionInterfacePlaceHolderScriptInstanceCreate gdextension_interface_placeholder_script_instance_create;
 extern "C" GDExtensionInterfacePlaceHolderScriptInstanceUpdate gdextension_interface_placeholder_script_instance_update;
 extern "C" GDExtensionInterfaceClassdbConstructObject gdextension_interface_classdb_construct_object;
@@ -177,6 +179,7 @@ extern "C" GDExtensionInterfaceClassdbGetMethodBind gdextension_interface_classd
 extern "C" GDExtensionInterfaceClassdbGetClassTag gdextension_interface_classdb_get_class_tag;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClass2 gdextension_interface_classdb_register_extension_class2;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassMethod gdextension_interface_classdb_register_extension_class_method;
+extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassVirtualMethod gdextension_interface_classdb_register_extension_class_virtual_method;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassIntegerConstant gdextension_interface_classdb_register_extension_class_integer_constant;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassProperty gdextension_interface_classdb_register_extension_class_property;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassPropertyIndexed gdextension_interface_classdb_register_extension_class_property_indexed;

include/godot_cpp/variant/callable_custom.hpp

@@ -41,6 +41,7 @@ class Object;
 class CallableCustomBase {
 public:
 	virtual ObjectID get_object() const = 0;
+	virtual int get_argument_count(bool &r_is_valid) const;
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const = 0;
 	virtual ~CallableCustomBase() {}
 };

include/godot_cpp/variant/callable_method_pointer.hpp

@@ -73,6 +73,11 @@ public:
 		return ObjectID(data.instance->get_instance_id());
 	}
 
+	virtual int get_argument_count(bool &r_is_valid) const override {
+		r_is_valid = true;
+		return sizeof...(P);
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
 		call_with_variant_args(data.instance, data.method, p_arguments, p_argcount, r_call_error);
 	}
@@ -110,6 +115,11 @@ public:
 		return ObjectID(data.instance->get_instance_id());
 	}
 
+	virtual int get_argument_count(bool &r_is_valid) const override {
+		r_is_valid = true;
+		return sizeof...(P);
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
 		call_with_variant_args_ret(data.instance, data.method, p_arguments, p_argcount, r_return_value, r_call_error);
 	}
@@ -147,6 +157,11 @@ public:
 		return ObjectID(data.instance->get_instance_id());
 	}
 
+	virtual int get_argument_count(bool &r_is_valid) const override {
+		r_is_valid = true;
+		return sizeof...(P);
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
 		call_with_variant_args_retc(data.instance, data.method, p_arguments, p_argcount, r_return_value, r_call_error);
 	}
@@ -182,6 +197,11 @@ public:
 		return ObjectID();
 	}
 
+	virtual int get_argument_count(bool &r_is_valid) const override {
+		r_is_valid = true;
+		return sizeof...(P);
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
 		call_with_variant_args_static_ret(data.method, p_arguments, p_argcount, r_return_value, r_call_error);
 		r_return_value = Variant();
@@ -218,6 +238,11 @@ public:
 		return ObjectID();
 	}
 
+	virtual int get_argument_count(bool &r_is_valid) const override {
+		r_is_valid = true;
+		return sizeof...(P);
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const override {
 		call_with_variant_args_static_ret(data.method, p_arguments, p_argcount, r_return_value, r_call_error);
 	}

include/godot_cpp/variant/typed_array.hpp

@@ -75,6 +75,8 @@ public:
 		}                                                                                                        \
 	};
 
+// All Variant::OBJECT types are intentionally omitted from this list because they are handled by
+// the unspecialized TypedArray definition.
 MAKE_TYPED_ARRAY(bool, Variant::BOOL)
 MAKE_TYPED_ARRAY(uint8_t, Variant::INT)
 MAKE_TYPED_ARRAY(int8_t, Variant::INT)
@@ -94,11 +96,14 @@ MAKE_TYPED_ARRAY(Rect2i, Variant::RECT2I)
 MAKE_TYPED_ARRAY(Vector3, Variant::VECTOR3)
 MAKE_TYPED_ARRAY(Vector3i, Variant::VECTOR3I)
 MAKE_TYPED_ARRAY(Transform2D, Variant::TRANSFORM2D)
+MAKE_TYPED_ARRAY(Vector4, Variant::VECTOR4)
+MAKE_TYPED_ARRAY(Vector4i, Variant::VECTOR4I)
 MAKE_TYPED_ARRAY(Plane, Variant::PLANE)
 MAKE_TYPED_ARRAY(Quaternion, Variant::QUATERNION)
 MAKE_TYPED_ARRAY(AABB, Variant::AABB)
 MAKE_TYPED_ARRAY(Basis, Variant::BASIS)
 MAKE_TYPED_ARRAY(Transform3D, Variant::TRANSFORM3D)
+MAKE_TYPED_ARRAY(Projection, Variant::PROJECTION)
 MAKE_TYPED_ARRAY(Color, Variant::COLOR)
 MAKE_TYPED_ARRAY(StringName, Variant::STRING_NAME)
 MAKE_TYPED_ARRAY(NodePath, Variant::NODE_PATH)
@@ -116,6 +121,10 @@ MAKE_TYPED_ARRAY(PackedStringArray, Variant::PACKED_STRING_ARRAY)
 MAKE_TYPED_ARRAY(PackedVector2Array, Variant::PACKED_VECTOR2_ARRAY)
 MAKE_TYPED_ARRAY(PackedVector3Array, Variant::PACKED_VECTOR3_ARRAY)
 MAKE_TYPED_ARRAY(PackedColorArray, Variant::PACKED_COLOR_ARRAY)
+// If the IPAddress struct is added to godot-cpp, the following could also be added:
+//MAKE_TYPED_ARRAY(IPAddress, Variant::STRING)
+
+#undef MAKE_TYPED_ARRAY
 
 } // namespace godot
 

src/core/class_db.cpp

@@ -32,6 +32,7 @@
 
 #include <godot_cpp/core/error_macros.hpp>
 #include <godot_cpp/godot.hpp>
+#include <godot_cpp/templates/vector.hpp>
 
 #include <godot_cpp/core/memory.hpp>
 
@@ -337,6 +338,46 @@ void ClassDB::bind_virtual_method(const StringName &p_class, const StringName &p
 	type.virtual_methods[p_method] = p_call;
 }
 
+void ClassDB::add_virtual_method(const StringName &p_class, const MethodInfo &p_method, const Vector<StringName> &p_arg_names) {
+	std::unordered_map<StringName, ClassInfo>::iterator type_it = classes.find(p_class);
+	ERR_FAIL_COND_MSG(type_it == classes.end(), String("Class '{0}' doesn't exist.").format(Array::make(p_class)));
+
+	GDExtensionClassVirtualMethodInfo mi;
+	mi.name = (GDExtensionStringNamePtr)&p_method.name;
+	mi.method_flags = p_method.flags;
+	mi.return_value = p_method.return_val._to_gdextension();
+	mi.return_value_metadata = p_method.return_val_metadata;
+	mi.argument_count = p_method.arguments.size();
+	if (mi.argument_count > 0) {
+		mi.arguments = (GDExtensionPropertyInfo *)memalloc(sizeof(GDExtensionPropertyInfo) * mi.argument_count);
+		mi.arguments_metadata = (GDExtensionClassMethodArgumentMetadata *)memalloc(sizeof(GDExtensionClassMethodArgumentMetadata) * mi.argument_count);
+		for (int i = 0; i < mi.argument_count; i++) {
+			mi.arguments[i] = p_method.arguments[i]._to_gdextension();
+			mi.arguments_metadata[i] = p_method.arguments_metadata[i];
+		}
+	} else {
+		mi.arguments = nullptr;
+		mi.arguments_metadata = nullptr;
+	}
+
+	if (p_arg_names.size() != mi.argument_count) {
+		WARN_PRINT("Mismatch argument name count for virtual method: " + String(p_class) + "::" + p_method.name);
+	} else {
+		for (int i = 0; i < p_arg_names.size(); i++) {
+			mi.arguments[i].name = (GDExtensionStringNamePtr)&p_arg_names[i];
+		}
+	}
+
+	internal::gdextension_interface_classdb_register_extension_class_virtual_method(internal::library, &p_class, &mi);
+
+	if (mi.arguments) {
+		memfree(mi.arguments);
+	}
+	if (mi.arguments_metadata) {
+		memfree(mi.arguments_metadata);
+	}
+}
+
 void ClassDB::initialize_class(const ClassInfo &p_cl) {
 }
 

src/godot.cpp

@@ -171,11 +171,13 @@ GDExtensionInterfaceObjectGetClassName gdextension_interface_object_get_class_na
 GDExtensionInterfaceObjectCastTo gdextension_interface_object_cast_to = nullptr;
 GDExtensionInterfaceObjectGetInstanceFromId gdextension_interface_object_get_instance_from_id = nullptr;
 GDExtensionInterfaceObjectGetInstanceId gdextension_interface_object_get_instance_id = nullptr;
-GDExtensionInterfaceCallableCustomCreate gdextension_interface_callable_custom_create = nullptr;
+GDExtensionInterfaceObjectHasScriptMethod gdextension_interface_object_has_script_method = nullptr;
+GDExtensionInterfaceObjectCallScriptMethod gdextension_interface_object_call_script_method = nullptr;
+GDExtensionInterfaceCallableCustomCreate2 gdextension_interface_callable_custom_create2 = nullptr;
 GDExtensionInterfaceCallableCustomGetUserData gdextension_interface_callable_custom_get_userdata = nullptr;
 GDExtensionInterfaceRefGetObject gdextension_interface_ref_get_object = nullptr;
 GDExtensionInterfaceRefSetObject gdextension_interface_ref_set_object = nullptr;
-GDExtensionInterfaceScriptInstanceCreate2 gdextension_interface_script_instance_create2 = nullptr;
+GDExtensionInterfaceScriptInstanceCreate3 gdextension_interface_script_instance_create3 = nullptr;
 GDExtensionInterfacePlaceHolderScriptInstanceCreate gdextension_interface_placeholder_script_instance_create = nullptr;
 GDExtensionInterfacePlaceHolderScriptInstanceUpdate gdextension_interface_placeholder_script_instance_update = nullptr;
 GDExtensionInterfaceClassdbConstructObject gdextension_interface_classdb_construct_object = nullptr;
@@ -183,6 +185,7 @@ GDExtensionInterfaceClassdbGetMethodBind gdextension_interface_classdb_get_metho
 GDExtensionInterfaceClassdbGetClassTag gdextension_interface_classdb_get_class_tag = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClass2 gdextension_interface_classdb_register_extension_class2 = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClassMethod gdextension_interface_classdb_register_extension_class_method = nullptr;
+GDExtensionInterfaceClassdbRegisterExtensionClassVirtualMethod gdextension_interface_classdb_register_extension_class_virtual_method = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClassIntegerConstant gdextension_interface_classdb_register_extension_class_integer_constant = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClassProperty gdextension_interface_classdb_register_extension_class_property = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClassPropertyIndexed gdextension_interface_classdb_register_extension_class_property_indexed = nullptr;
@@ -408,11 +411,13 @@ GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_ge
 	LOAD_PROC_ADDRESS(object_cast_to, GDExtensionInterfaceObjectCastTo);
 	LOAD_PROC_ADDRESS(object_get_instance_from_id, GDExtensionInterfaceObjectGetInstanceFromId);
 	LOAD_PROC_ADDRESS(object_get_instance_id, GDExtensionInterfaceObjectGetInstanceId);
-	LOAD_PROC_ADDRESS(callable_custom_create, GDExtensionInterfaceCallableCustomCreate);
+	LOAD_PROC_ADDRESS(object_has_script_method, GDExtensionInterfaceObjectHasScriptMethod);
+	LOAD_PROC_ADDRESS(object_call_script_method, GDExtensionInterfaceObjectCallScriptMethod);
+	LOAD_PROC_ADDRESS(callable_custom_create2, GDExtensionInterfaceCallableCustomCreate2);
 	LOAD_PROC_ADDRESS(callable_custom_get_userdata, GDExtensionInterfaceCallableCustomGetUserData);
 	LOAD_PROC_ADDRESS(ref_get_object, GDExtensionInterfaceRefGetObject);
 	LOAD_PROC_ADDRESS(ref_set_object, GDExtensionInterfaceRefSetObject);
-	LOAD_PROC_ADDRESS(script_instance_create2, GDExtensionInterfaceScriptInstanceCreate2);
+	LOAD_PROC_ADDRESS(script_instance_create3, GDExtensionInterfaceScriptInstanceCreate3);
 	LOAD_PROC_ADDRESS(placeholder_script_instance_create, GDExtensionInterfacePlaceHolderScriptInstanceCreate);
 	LOAD_PROC_ADDRESS(placeholder_script_instance_update, GDExtensionInterfacePlaceHolderScriptInstanceUpdate);
 	LOAD_PROC_ADDRESS(classdb_construct_object, GDExtensionInterfaceClassdbConstructObject);
@@ -420,6 +425,7 @@ GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_ge
 	LOAD_PROC_ADDRESS(classdb_get_class_tag, GDExtensionInterfaceClassdbGetClassTag);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class2, GDExtensionInterfaceClassdbRegisterExtensionClass2);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_method, GDExtensionInterfaceClassdbRegisterExtensionClassMethod);
+	LOAD_PROC_ADDRESS(classdb_register_extension_class_virtual_method, GDExtensionInterfaceClassdbRegisterExtensionClassVirtualMethod);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_integer_constant, GDExtensionInterfaceClassdbRegisterExtensionClassIntegerConstant);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_property, GDExtensionInterfaceClassdbRegisterExtensionClassProperty);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_property_indexed, GDExtensionInterfaceClassdbRegisterExtensionClassPropertyIndexed);

src/variant/callable_custom.cpp

@@ -35,6 +35,11 @@
 
 namespace godot {
 
+int CallableCustomBase::get_argument_count(bool &r_is_valid) const {
+	r_is_valid = false;
+	return 0;
+}
+
 static void callable_custom_call(void *p_userdata, const GDExtensionConstVariantPtr *p_args, GDExtensionInt p_argument_count, GDExtensionVariantPtr r_return, GDExtensionCallError *r_error) {
 	CallableCustom *callable_custom = (CallableCustom *)p_userdata;
 	callable_custom->call((const Variant **)p_args, p_argument_count, *(Variant *)r_return, *r_error);
@@ -84,13 +89,21 @@ static GDExtensionBool callable_custom_less_than_func(void *p_a, void *p_b) {
 	return func_a(a, b);
 }
 
+static GDExtensionInt custom_callable_get_argument_count_func(void *p_userdata, GDExtensionBool *r_is_valid) {
+	CallableCustom *callable_custom = (CallableCustom *)p_userdata;
+	bool valid = false;
+	int ret = callable_custom->get_argument_count(valid);
+	*r_is_valid = valid;
+	return ret;
+}
+
 bool CallableCustom::is_valid() const {
 	// The same default implementation as in Godot.
 	return ObjectDB::get_instance(get_object());
 }
 
 Callable::Callable(CallableCustom *p_callable_custom) {
-	GDExtensionCallableCustomInfo info = {};
+	GDExtensionCallableCustomInfo2 info = {};
 	info.callable_userdata = p_callable_custom;
 	info.token = internal::token;
 	info.object_id = p_callable_custom->get_object();
@@ -101,8 +114,9 @@ Callable::Callable(CallableCustom *p_callable_custom) {
 	info.equal_func = &callable_custom_equal_func;
 	info.less_than_func = &callable_custom_less_than_func;
 	info.to_string_func = &callable_custom_to_string;
+	info.get_argument_count_func = &custom_callable_get_argument_count_func;
 
-	::godot::internal::gdextension_interface_callable_custom_create(_native_ptr(), &info);
+	::godot::internal::gdextension_interface_callable_custom_create2(_native_ptr(), &info);
 }
 
 CallableCustom *Callable::get_custom() const {

src/variant/callable_method_pointer.cpp

@@ -77,6 +77,14 @@ static GDExtensionBool custom_callable_mp_less_than_func(void *p_a, void *p_b) {
 	return memcmp(a->get_comp_ptr(), b->get_comp_ptr(), a->get_comp_size() * 4) < 0;
 }
 
+static GDExtensionInt custom_callable_mp_get_argument_count_func(void *p_userdata, GDExtensionBool *r_is_valid) {
+	CallableCustomMethodPointerBase *callable_method_pointer = (CallableCustomMethodPointerBase *)p_userdata;
+	bool valid = false;
+	int ret = callable_method_pointer->get_argument_count(valid);
+	*r_is_valid = valid;
+	return ret;
+}
+
 void CallableCustomMethodPointerBase::_setup(uint32_t *p_base_ptr, uint32_t p_ptr_size) {
 	comp_ptr = p_base_ptr;
 	comp_size = p_ptr_size / 4;
@@ -93,7 +101,7 @@ void CallableCustomMethodPointerBase::_setup(uint32_t *p_base_ptr, uint32_t p_pt
 namespace internal {
 
 Callable create_callable_from_ccmp(CallableCustomMethodPointerBase *p_callable_method_pointer) {
-	GDExtensionCallableCustomInfo info = {};
+	GDExtensionCallableCustomInfo2 info = {};
 	info.callable_userdata = p_callable_method_pointer;
 	info.token = internal::token;
 	info.object_id = p_callable_method_pointer->get_object();
@@ -103,9 +111,10 @@ Callable create_callable_from_ccmp(CallableCustomMethodPointerBase *p_callable_m
 	info.hash_func = &custom_callable_mp_hash;
 	info.equal_func = &custom_callable_mp_equal_func;
 	info.less_than_func = &custom_callable_mp_less_than_func;
+	info.get_argument_count_func = &custom_callable_mp_get_argument_count_func;
 
 	Callable callable;
-	::godot::internal::gdextension_interface_callable_custom_create(callable._native_ptr(), &info);
+	::godot::internal::gdextension_interface_callable_custom_create2(callable._native_ptr(), &info);
 	return callable;
 }
 

test/project/example.gd

@@ -0,0 +1,5 @@
+extends Example
+
+func _do_something_virtual(p_name, p_value):
+	custom_signal.emit(p_name, p_value)
+	return "Implemented"

test/project/main.gd

@@ -102,6 +102,7 @@ func _ready():
 	# mp_callable() with void method.
 	var mp_callable: Callable = example.test_callable_mp()
 	assert_equal(mp_callable.is_valid(), true)
+	assert_equal(mp_callable.get_argument_count(), 3)
 	mp_callable.call(example, "void", 36)
 	assert_equal(custom_signal_emitted, ["unbound_method1: Example - void", 36])
 
@@ -117,14 +118,17 @@ func _ready():
 
 	# mp_callable() with return value.
 	var mp_callable_ret: Callable = example.test_callable_mp_ret()
+	assert_equal(mp_callable_ret.get_argument_count(), 3)
 	assert_equal(mp_callable_ret.call(example, "test", 77), "unbound_method2: Example - test - 77")
 
 	# mp_callable() with const method and return value.
 	var mp_callable_retc: Callable = example.test_callable_mp_retc()
+	assert_equal(mp_callable_retc.get_argument_count(), 3)
 	assert_equal(mp_callable_retc.call(example, "const", 101), "unbound_method3: Example - const - 101")
 
 	# mp_callable_static() with void method.
 	var mp_callable_static: Callable = example.test_callable_mp_static()
+	assert_equal(mp_callable_static.get_argument_count(), 3)
 	mp_callable_static.call(example, "static", 83)
 	assert_equal(custom_signal_emitted, ["unbound_static_method1: Example - static", 83])
 
@@ -140,6 +144,7 @@ func _ready():
 
 	# mp_callable_static() with return value.
 	var mp_callable_static_ret: Callable = example.test_callable_mp_static_ret()
+	assert_equal(mp_callable_static_ret.get_argument_count(), 3)
 	assert_equal(mp_callable_static_ret.call(example, "static-ret", 84), "unbound_static_method2: Example - static-ret - 84")
 
 	# CallableCustom.
@@ -150,6 +155,7 @@ func _ready():
 	assert_equal(custom_callable.hash(), 27);
 	assert_equal(custom_callable.get_object(), null);
 	assert_equal(custom_callable.get_method(), "");
+	assert_equal(custom_callable.get_argument_count(), 2)
 	assert_equal(str(custom_callable), "<MyCallableCustom>");
 
 	# PackedArray iterators
@@ -241,6 +247,10 @@ func _ready():
 	assert_equal(new_example_ref.was_post_initialized(), true)
 	assert_equal(example.test_post_initialize(), true)
 
+	# Test a virtual method defined in GDExtension and implemented in script.
+	assert_equal(example.test_virtual_implemented_in_script("Virtual", 939), "Implemented")
+	assert_equal(custom_signal_emitted, ["Virtual", 939])
+
 	exit_with_status()
 
 func _on_Example_custom_signal(signal_name, value):

test/project/main.tscn

@@ -1,11 +1,13 @@
-[gd_scene load_steps=2 format=3 uid="uid://dmx2xuigcpvt4"]
+[gd_scene load_steps=3 format=3 uid="uid://dmx2xuigcpvt4"]
 
 [ext_resource type="Script" path="res://main.gd" id="1_qesh5"]
+[ext_resource type="Script" path="res://example.gd" id="2_jju25"]
 
 [node name="Node" type="Node"]
 script = ExtResource("1_qesh5")
 
 [node name="Example" type="Example" parent="."]
+script = ExtResource("2_jju25")
 
 [node name="ExampleMin" type="ExampleMin" parent="Example"]
 layout_mode = 0

test/src/example.cpp

@@ -49,6 +49,11 @@ public:
 		return ObjectID();
 	}
 
+	virtual int get_argument_count(bool &r_is_valid) const {
+		r_is_valid = true;
+		return 2;
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const {
 		r_return_value = "Hi";
 		r_call_error.error = GDEXTENSION_CALL_OK;
@@ -230,6 +235,9 @@ void Example::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("callable_bind"), &Example::callable_bind);
 	ClassDB::bind_method(D_METHOD("test_post_initialize"), &Example::test_post_initialize);
 
+	GDVIRTUAL_BIND(_do_something_virtual, "name", "value");
+	ClassDB::bind_method(D_METHOD("test_virtual_implemented_in_script"), &Example::test_virtual_implemented_in_script);
+
 	ClassDB::bind_static_method("Example", D_METHOD("test_static", "a", "b"), &Example::test_static);
 	ClassDB::bind_static_method("Example", D_METHOD("test_static2"), &Example::test_static2);
 
@@ -626,3 +634,11 @@ void Example::_input(const Ref<InputEvent> &event) {
 		emit_custom_signal(String("_input: ") + key_event->get_key_label(), key_event->get_unicode());
 	}
 }
+
+String Example::test_virtual_implemented_in_script(const String &p_name, int p_value) {
+	String ret;
+	if (GDVIRTUAL_CALL(_do_something_virtual, p_name, p_value, ret)) {
+		return ret;
+	}
+	return "Unimplemented";
+}

test/src/example.h

@@ -24,6 +24,7 @@
 #include <godot_cpp/variant/variant.hpp>
 
 #include <godot_cpp/core/binder_common.hpp>
+#include <godot_cpp/core/gdvirtual.gen.inc>
 
 using namespace godot;
 
@@ -181,6 +182,9 @@ public:
 	// Virtual function override (no need to bind manually).
 	virtual bool _has_point(const Vector2 &point) const override;
 	virtual void _input(const Ref<InputEvent> &event) override;
+
+	GDVIRTUAL2R(String, _do_something_virtual, String, int);
+	String test_virtual_implemented_in_script(const String &p_name, int p_value);
 };
 
 VARIANT_ENUM_CAST(Example::Constants);