[Core] Add methods to get argument count of Callables

godotengine · Jan 28, 2024 · 5b48574 · 5b48574
1 parent 17e7f85
commit 5b48574
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diff --git a/core/extension/gdextension_interface.cpp b/core/extension/gdextension_interface.cpp
@@ -141,6 +141,11 @@ class CallableCustomExtension : public CallableCustom {
 		return object;
 	}
 
+	int get_argument_count() const override {
+		// TODO
+		return 0;
+	}
+
 	void *get_userdata(void *p_token) const {
 		return (p_token == token) ? userdata : nullptr;
 	}

diff --git a/core/object/callable_method_pointer.h b/core/object/callable_method_pointer.h
@@ -93,6 +93,10 @@ class CallableCustomMethodPointer : public CallableCustomMethodPointerBase {
 		return data.instance->get_instance_id();
 	}
 
+	virtual int get_argument_count() const {
+		return sizeof...(P);
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const {
 		ERR_FAIL_NULL_MSG(ObjectDB::get_instance(ObjectID(data.object_id)), "Invalid Object id '" + uitos(data.object_id) + "', can't call method.");
 		call_with_variant_args(data.instance, data.method, p_arguments, p_argcount, r_call_error);
@@ -140,6 +144,10 @@ class CallableCustomMethodPointerRet : public CallableCustomMethodPointerBase {
 		return data.instance->get_instance_id();
 	}
 
+	virtual int get_argument_count() const {
+		return sizeof...(P);
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const {
 		ERR_FAIL_NULL_MSG(ObjectDB::get_instance(ObjectID(data.object_id)), "Invalid Object id '" + uitos(data.object_id) + "', can't call method.");
 		call_with_variant_args_ret(data.instance, data.method, p_arguments, p_argcount, r_return_value, r_call_error);
@@ -187,6 +195,10 @@ class CallableCustomMethodPointerRetC : public CallableCustomMethodPointerBase {
 		return data.instance->get_instance_id();
 	}
 
+	virtual int get_argument_count() const override {
+		return sizeof...(P);
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const override {
 		ERR_FAIL_NULL_MSG(ObjectDB::get_instance(ObjectID(data.object_id)), "Invalid Object id '" + uitos(data.object_id) + "', can't call method.");
 		call_with_variant_args_retc(data.instance, data.method, p_arguments, p_argcount, r_return_value, r_call_error);
@@ -238,6 +250,10 @@ class CallableCustomStaticMethodPointer : public CallableCustomMethodPointerBase
 		return ObjectID();
 	}
 
+	virtual int get_argument_count() const override {
+		return sizeof...(P);
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &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();
@@ -280,6 +296,10 @@ class CallableCustomStaticMethodPointerRet : public CallableCustomMethodPointerB
 		return ObjectID();
 	}
 
+	virtual int get_argument_count() const override {
+		return sizeof...(P);
+	}
+
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const override {
 		call_with_variant_args_static_ret(data.method, p_arguments, p_argcount, r_return_value, r_call_error);
 	}

diff --git a/core/object/object.cpp b/core/object/object.cpp
@@ -679,6 +679,28 @@ bool Object::has_method(const StringName &p_method) const {
 	return false;
 }
 
+int Object::get_method_argument_count(const StringName &p_method) const {
+	if (p_method == CoreStringNames::get_singleton()->_free) {
+		return 0;
+	}
+
+	if (script_instance && script_instance->has_method(p_method)) {
+		return script_instance->get_method_argument_count(p_method);
+	}
+
+	MethodBind *method = ClassDB::get_method(get_class_name(), p_method);
+	if (method != nullptr) {
+		return method->get_argument_count();
+	}
+
+	const Script *scr = Object::cast_to<Script>(this);
+	if (scr != nullptr && scr->has_static_method(p_method)) {
+		return scr->get_method_argument_count(p_method);
+	}
+
+	return 0;
+}
+
 Variant Object::getvar(const Variant &p_key, bool *r_valid) const {
 	if (r_valid) {
 		*r_valid = false;
@@ -1624,6 +1646,8 @@ void Object::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("has_method", "method"), &Object::has_method);
 
+	ClassDB::bind_method(D_METHOD("get_method_argument_count", "method"), &Object::get_method_argument_count);
+
 	ClassDB::bind_method(D_METHOD("has_signal", "signal"), &Object::has_signal);
 	ClassDB::bind_method(D_METHOD("get_signal_list"), &Object::_get_signal_list);
 	ClassDB::bind_method(D_METHOD("get_signal_connection_list", "signal"), &Object::_get_signal_connection_list);

diff --git a/core/object/object.h b/core/object/object.h
@@ -856,6 +856,7 @@ class Object {
 	Variant property_get_revert(const StringName &p_name) const;
 
 	bool has_method(const StringName &p_method) const;
+	int get_method_argument_count(const StringName &p_method) const;
 	void get_method_list(List<MethodInfo> *p_list) const;
 	Variant callv(const StringName &p_method, const Array &p_args);
 	virtual Variant callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error);

diff --git a/core/object/script_instance.h b/core/object/script_instance.h
@@ -53,6 +53,8 @@ class ScriptInstance {
 	virtual void get_method_list(List<MethodInfo> *p_list) const = 0;
 	virtual bool has_method(const StringName &p_method) const = 0;
 
+	virtual int get_method_argument_count(const StringName &p_method) const = 0;
+
 	virtual Variant callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) = 0;
 
 	template <typename... VarArgs>

diff --git a/core/object/script_language.h b/core/object/script_language.h
@@ -150,6 +150,8 @@ class Script : public Resource {
 	virtual bool has_method(const StringName &p_method) const = 0;
 	virtual bool has_static_method(const StringName &p_method) const { return false; }
 
+	virtual int get_method_argument_count(const StringName &p_method) const = 0;
+
 	virtual MethodInfo get_method_info(const StringName &p_method) const = 0;
 
 	virtual bool is_tool() const = 0;
@@ -426,6 +428,8 @@ class PlaceHolderScriptInstance : public ScriptInstance {
 	virtual void get_method_list(List<MethodInfo> *p_list) const override;
 	virtual bool has_method(const StringName &p_method) const override;
 
+	virtual int get_method_argument_count(const StringName &p_method) const override { return 0; }
+
 	virtual Variant callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) override {
 		r_error.error = Callable::CallError::CALL_ERROR_INVALID_METHOD;
 		return Variant();

diff --git a/core/object/script_language_extension.cpp b/core/object/script_language_extension.cpp
@@ -56,6 +56,9 @@ void ScriptExtension::_bind_methods() {
 
 	GDVIRTUAL_BIND(_has_method, "method");
 	GDVIRTUAL_BIND(_has_static_method, "method");
+
+	GDVIRTUAL_BIND(_get_method_argument_count, "method");
+
 	GDVIRTUAL_BIND(_get_method_info, "method");
 
 	GDVIRTUAL_BIND(_is_tool);

diff --git a/core/object/script_language_extension.h b/core/object/script_language_extension.h
@@ -101,6 +101,8 @@ class ScriptExtension : public Script {
 	EXBIND1RC(bool, has_method, const StringName &)
 	EXBIND1RC(bool, has_static_method, const StringName &)
 
+	EXBIND1RC(int, get_method_argument_count, const StringName &)
+
 	GDVIRTUAL1RC(Dictionary, _get_method_info, const StringName &)
 	virtual MethodInfo get_method_info(const StringName &p_method) const override {
 		Dictionary mi;
@@ -791,6 +793,11 @@ class ScriptInstanceExtension : public ScriptInstance {
 		return false;
 	}
 
+	virtual int get_method_argument_count(const StringName &p_method) const override {
+		// TODO
+		return 0;
+	}
+
 	virtual Variant callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) override {
 		Variant ret;
 		if (native_info->call_func) {

diff --git a/core/variant/callable.cpp b/core/variant/callable.cpp
@@ -162,6 +162,16 @@ StringName Callable::get_method() const {
 	return method;
 }
 
+int Callable::get_argument_count() const {
+	if (is_null()) {
+		return 0;
+	} else if (is_custom()) {
+		return custom->get_argument_count();
+	} else {
+		return get_object()->get_method_argument_count(method);
+	}
+}
+
 int Callable::get_bound_arguments_count() const {
 	if (!is_null() && is_custom()) {
 		return custom->get_bound_arguments_count();

diff --git a/core/variant/callable.h b/core/variant/callable.h
@@ -109,6 +109,7 @@ class Callable {
 	ObjectID get_object_id() const;
 	StringName get_method() const;
 	CallableCustom *get_custom() const;
+	int get_argument_count() const;
 	int get_bound_arguments_count() const;
 	void get_bound_arguments_ref(Vector<Variant> &r_arguments, int &r_argcount) const; // Internal engine use, the exposed one is below.
 	Array get_bound_arguments() const;
@@ -153,6 +154,7 @@ class CallableCustom {
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const = 0;
 	virtual Error rpc(int p_peer_id, const Variant **p_arguments, int p_argcount, Callable::CallError &r_call_error) const;
 	virtual const Callable *get_base_comparator() const;
+	virtual int get_argument_count() const = 0;
 	virtual int get_bound_arguments_count() const;
 	virtual void get_bound_arguments(Vector<Variant> &r_arguments, int &r_argcount) const;
 

diff --git a/core/variant/callable_bind.cpp b/core/variant/callable_bind.cpp
@@ -91,6 +91,10 @@ const Callable *CallableCustomBind::get_base_comparator() const {
 	return callable.get_base_comparator();
 }
 
+int CallableCustomBind::get_argument_count() const {
+	return callable.get_argument_count() - binds.size();
+}
+
 int CallableCustomBind::get_bound_arguments_count() const {
 	return callable.get_bound_arguments_count() + binds.size();
 }
@@ -225,6 +229,10 @@ const Callable *CallableCustomUnbind::get_base_comparator() const {
 	return callable.get_base_comparator();
 }
 
+int CallableCustomUnbind::get_argument_count() const {
+	return callable.get_argument_count() + argcount;
+}
+
 int CallableCustomUnbind::get_bound_arguments_count() const {
 	return callable.get_bound_arguments_count() - argcount;
 }

diff --git a/core/variant/callable_bind.h b/core/variant/callable_bind.h
@@ -53,6 +53,7 @@ class CallableCustomBind : public CallableCustom {
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const override;
 	virtual Error rpc(int p_peer_id, const Variant **p_arguments, int p_argcount, Callable::CallError &r_call_error) const override;
 	virtual const Callable *get_base_comparator() const override;
+	virtual int get_argument_count() const override;
 	virtual int get_bound_arguments_count() const override;
 	virtual void get_bound_arguments(Vector<Variant> &r_arguments, int &r_argcount) const override;
 	Callable get_callable() { return callable; }
@@ -81,6 +82,7 @@ class CallableCustomUnbind : public CallableCustom {
 	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const override;
 	virtual Error rpc(int p_peer_id, const Variant **p_arguments, int p_argcount, Callable::CallError &r_call_error) const override;
 	virtual const Callable *get_base_comparator() const override;
+	virtual int get_argument_count() const override;
 	virtual int get_bound_arguments_count() const override;
 	virtual void get_bound_arguments(Vector<Variant> &r_arguments, int &r_argcount) const override;
 

diff --git a/core/variant/variant_call.cpp b/core/variant/variant_call.cpp
@@ -2046,6 +2046,7 @@ static void _register_variant_builtin_methods() {
 	bind_method(Callable, get_object, sarray(), varray());
 	bind_method(Callable, get_object_id, sarray(), varray());
 	bind_method(Callable, get_method, sarray(), varray());
+	bind_method(Callable, get_argument_count, sarray(), varray());
 	bind_method(Callable, get_bound_arguments_count, sarray(), varray());
 	bind_method(Callable, get_bound_arguments, sarray(), varray());
 	bind_method(Callable, hash, sarray(), varray());

diff --git a/core/variant/variant_callable.cpp b/core/variant/variant_callable.cpp
@@ -68,6 +68,10 @@ ObjectID VariantCallable::get_object() const {
 	return ObjectID();
 }
 
+int VariantCallable::get_argument_count() const {
+	return Variant::get_builtin_method_argument_count(variant.get_type(), method);
+}
+
 void VariantCallable::call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const {
 	Variant v = variant;
 	v.callp(method, p_arguments, p_argcount, r_return_value, r_call_error);

diff --git a/core/variant/variant_callable.h b/core/variant/variant_callable.h
@@ -50,6 +50,7 @@ class VariantCallable : public CallableCustom {
 	bool is_valid() const override;
 	StringName get_method() const override;
 	ObjectID get_object() const override;
+	int get_argument_count() const override;
 	void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, Callable::CallError &r_call_error) const override;
 
 	VariantCallable(const Variant &p_variant, const StringName &p_method);

diff --git a/doc/classes/Callable.xml b/doc/classes/Callable.xml
@@ -112,6 +112,12 @@
 				Calls the method represented by this [Callable]. Unlike [method call], this method expects all arguments to be contained inside the [param arguments] [Array].
 			</description>
 		</method>
+		<method name="get_argument_count" qualifiers="const">
+			<return type="int" />
+			<description>
+				Returns the total number of arguments of this [Callable], accounting for any bound (or unbound) arguments. The number of bound arguments is subtracted from the total, and the number of unbound arguments are added.
+			</description>
+		</method>
 		<method name="get_bound_arguments" qualifiers="const">
 			<return type="Array" />
 			<description>

diff --git a/doc/classes/Object.xml b/doc/classes/Object.xml
@@ -682,6 +682,14 @@
 				Returns the object's metadata entry names as a [PackedStringArray].
 			</description>
 		</method>
+		<method name="get_method_argument_count" qualifiers="const">
+			<return type="int" />
+			<param index="0" name="method" type="StringName" />
+			<description>
+				Returns the number of arguments of the given [param method].
+				[b]Note:[/b] In C#, [param method] must be in snake_case when referring to built-in Godot methods. Prefer using the names exposed in the [code]MethodName[/code] class to avoid allocating a new [StringName] on each call.
+			</description>
+		</method>
 		<method name="get_method_list" qualifiers="const">
 			<return type="Dictionary[]" />
 			<description>

diff --git a/doc/classes/ScriptExtension.xml b/doc/classes/ScriptExtension.xml
@@ -63,6 +63,12 @@
 			<description>
 			</description>
 		</method>
+		<method name="_get_method_argument_count" qualifiers="virtual const">
+			<return type="int" />
+			<param index="0" name="method" type="StringName" />
+			<description>
+			</description>
+		</method>
 		<method name="_get_method_info" qualifiers="virtual const">
 			<return type="Dictionary" />
 			<param index="0" name="method" type="StringName" />

diff --git a/modules/gdscript/gdscript.cpp b/modules/gdscript/gdscript.cpp
@@ -352,6 +352,15 @@ bool GDScript::has_static_method(const StringName &p_method) const {
 	return member_functions.has(p_method) && member_functions[p_method]->is_static();
 }
 
+int GDScript::get_method_argument_count(const StringName &p_method) const {
+	HashMap<StringName, GDScriptFunction *>::ConstIterator E = member_functions.find(p_method);
+	if (!E) {
+		return 0;
+	}
+
+	return E->value->get_argument_count();
+}
+
 MethodInfo GDScript::get_method_info(const StringName &p_method) const {
 	HashMap<StringName, GDScriptFunction *>::ConstIterator E = member_functions.find(p_method);
 	if (!E) {
@@ -1916,6 +1925,19 @@ bool GDScriptInstance::has_method(const StringName &p_method) const {
 	return false;
 }
 
+int GDScriptInstance::get_method_argument_count(const StringName &p_method) const {
+	const GDScript *sptr = script.ptr();
+	while (sptr) {
+		HashMap<StringName, GDScriptFunction *>::ConstIterator E = sptr->member_functions.find(p_method);
+		if (E) {
+			return E->value->get_argument_count();
+		}
+		sptr = sptr->_base;
+	}
+
+	return 0;
+}
+
 Variant GDScriptInstance::callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) {
 	GDScript *sptr = script.ptr();
 	if (unlikely(p_method == SNAME("_ready"))) {

diff --git a/modules/gdscript/gdscript.h b/modules/gdscript/gdscript.h
@@ -305,6 +305,9 @@ class GDScript : public Script {
 	virtual void get_script_method_list(List<MethodInfo> *p_list) const override;
 	virtual bool has_method(const StringName &p_method) const override;
 	virtual bool has_static_method(const StringName &p_method) const override;
+
+	virtual int get_method_argument_count(const StringName &p_method) const override;
+
 	virtual MethodInfo get_method_info(const StringName &p_method) const override;
 
 	virtual void get_script_property_list(List<PropertyInfo> *p_list) const override;
@@ -369,6 +372,9 @@ class GDScriptInstance : public ScriptInstance {
 
 	virtual void get_method_list(List<MethodInfo> *p_list) const;
 	virtual bool has_method(const StringName &p_method) const;
+
+	virtual int get_method_argument_count(const StringName &p_method) const;
+
 	virtual Variant callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error);
 
 	Variant debug_get_member_by_index(int p_idx) const { return members[p_idx]; }

diff --git a/modules/gdscript/gdscript_function.h b/modules/gdscript/gdscript_function.h
@@ -511,6 +511,7 @@ class GDScriptFunction {
 	_FORCE_INLINE_ GDScript *get_script() const { return _script; }
 	_FORCE_INLINE_ bool is_static() const { return _static; }
 	_FORCE_INLINE_ MethodInfo get_method_info() const { return method_info; }
+	_FORCE_INLINE_ int get_argument_count() const { return _argument_count; }
 	_FORCE_INLINE_ Variant get_rpc_config() const { return rpc_config; }
 	_FORCE_INLINE_ int get_max_stack_size() const { return _stack_size; }