Add 4.2 branch to README

Send NOTIFICATION_POSTINITIALIZE to extension classes

.github/workflows/ci.yml

@@ -65,7 +65,7 @@ jobs:
             platform: android
             artifact-name: godot-cpp-android-arm64-release
             artifact-path: bin/libgodot-cpp.android.template_release.arm64.a
-            flags: ANDROID_NDK_ROOT=$ANDROID_NDK_LATEST_HOME arch=arm64
+            flags: arch=arm64
             run-tests: false
             cache-name: android-arm64
 
@@ -78,12 +78,22 @@ jobs:
             run-tests: false
             cache-name: ios-arm64
 
+          - name: 🌐 Web (wasm32)
+            os: ubuntu-20.04
+            platform: web
+            artifact-name: godot-cpp-web-wasm32-release
+            artifact-path: bin/libgodot-cpp.web.template_release.wasm32.a
+            run-tests: false
+            cache-name: web-wasm32
+
     env:
       SCONS_CACHE: ${{ github.workspace }}/.scons-cache/
+      EM_VERSION: 3.1.39
+      EM_CACHE_FOLDER: "emsdk-cache"
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: recursive
 
@@ -98,19 +108,29 @@ jobs:
         with:
           python-version: '3.x'
 
-      - name: Linux dependencies
-        if: ${{ matrix.platform == 'linux' }}
-        run: |
-          sudo apt-get update -qq
-          sudo apt-get install -qqq build-essential pkg-config
+      - name: Android dependencies
+        if: ${{ matrix.platform == 'android' }}
+        uses: nttld/setup-ndk@v1
+        with:
+          ndk-version: r23c
+          link-to-sdk: true
 
-      - name: Install scons
-        run: |
-          python -m pip install scons==4.0.0
+      - name: Web dependencies
+        if: ${{ matrix.platform == 'web' }}
+        uses: mymindstorm/setup-emsdk@v13
+        with:
+          version: ${{env.EM_VERSION}}
+          actions-cache-folder: ${{env.EM_CACHE_FOLDER}}
 
       - name: Setup MinGW for Windows/MinGW build
         if: ${{ matrix.platform == 'windows' && matrix.flags == 'use_mingw=yes' }}
         uses: egor-tensin/setup-mingw@v2
+        with:
+          version: 12.2.0
+
+      - name: Install scons
+        run: |
+          python -m pip install scons==4.0.0
 
       - name: Generate godot-cpp sources only
         run: |
@@ -153,7 +173,7 @@ jobs:
           ./godot-artifacts/godot.linuxbsd.editor.x86_64.mono --headless --version
           cd test
           # Need to run the editor so .godot is generated... but it crashes! Ignore that :-)
-          (cd project && (../../godot-artifacts/godot.linuxbsd.editor.x86_64.mono --editor --headless --quit >/dev/null 2>&1 || true))
+          (cd project && (timeout 10 ../../godot-artifacts/godot.linuxbsd.editor.x86_64.mono --editor --headless --quit >/dev/null 2>&1 || true))
           GODOT=../godot-artifacts/godot.linuxbsd.editor.x86_64.mono ./run-tests.sh
 
       - name: Upload artifact
@@ -168,7 +188,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: recursive
 
@@ -192,7 +212,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: recursive
 
@@ -216,7 +236,7 @@ jobs:
     runs-on: windows-2019
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           submodules: recursive
 

.github/workflows/static_checks.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       # Azure repositories are not reliable, we need to prevent Azure giving us packages.
       - name: Make apt sources.list use the default Ubuntu repositories

.gitignore

@@ -100,7 +100,7 @@ AppPackages/
 
 # Others
 sql/
-*.Cache
+*.[Cc]ache
 ClientBin/
 [Ss]tyle[Cc]op.*
 ~$*
@@ -191,3 +191,7 @@ godot.creator.*
 
 # compile commands (https://clang.llvm.org/docs/JSONCompilationDatabase.html)
 compile_commands.json
+
+# Python development
+.venv
+venv

CMakeLists.txt

@@ -72,21 +72,22 @@ endif()
 # Input from user for GDExtension interface header and the API JSON file
 set(GODOT_GDEXTENSION_DIR "gdextension" CACHE STRING "")
 set(GODOT_CUSTOM_API_FILE "" CACHE STRING "")
-set(FLOAT_PRECISION "single" CACHE STRING "")
-if ("${FLOAT_PRECISION}" STREQUAL "double")
-	add_definitions(-DREAL_T_IS_DOUBLE)
-endif()
 
 set(GODOT_GDEXTENSION_API_FILE "${GODOT_GDEXTENSION_DIR}/extension_api.json")
 if (NOT "${GODOT_CUSTOM_API_FILE}" STREQUAL "")  # User-defined override.
 	set(GODOT_GDEXTENSION_API_FILE "${GODOT_CUSTOM_API_FILE}")
 endif()
 
+set(FLOAT_PRECISION "single" CACHE STRING "")
+if ("${FLOAT_PRECISION}" STREQUAL "double")
+	add_definitions(-DREAL_T_IS_DOUBLE)
+endif()
+
 set(GODOT_COMPILE_FLAGS )
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
 	# using Visual Studio C++
-	set(GODOT_COMPILE_FLAGS "/EHsc") # /GF /MP
+	set(GODOT_COMPILE_FLAGS "/utf-8") # /GF /MP
 
 	if(CMAKE_BUILD_TYPE MATCHES Debug)
 		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /MDd") # /Od /RTC1 /Zi
@@ -98,15 +99,28 @@ if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
 
 	add_definitions(-DNOMINMAX)
 else()  # GCC/Clang
-	set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -g")
-
 	if(CMAKE_BUILD_TYPE MATCHES Debug)
-		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -fno-omit-frame-pointer -O0")
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -fno-omit-frame-pointer -O0 -g")
 	else()
 		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -O3")
 	endif(CMAKE_BUILD_TYPE MATCHES Debug)
 endif()
 
+# Disable exception handling. Godot doesn't use exceptions anywhere, and this
+# saves around 20% of binary size and very significant build time (GH-80513).
+option(GODOT_DISABLE_EXCEPTIONS ON "Force disabling exception handling code")
+if (GODOT_DISABLE_EXCEPTIONS)
+	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -D_HAS_EXCEPTIONS=0")
+	else()
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -fno-exceptions")
+	endif()
+else()
+	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /EHsc")
+	endif()
+endif()
+
 # Generate source from the bindings file
 find_package(Python3 3.4 REQUIRED) # pathlib should be present
 if(GENERATE_TEMPLATE_GET_NODE)
@@ -118,6 +132,7 @@ endif()
 execute_process(COMMAND "${Python3_EXECUTABLE}" "-c" "import binding_generator; binding_generator.print_file_list(\"${GODOT_GDEXTENSION_API_FILE}\", \"${CMAKE_CURRENT_BINARY_DIR}\", headers=True, sources=True)"
 	WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
 	OUTPUT_VARIABLE GENERATED_FILES_LIST
+	OUTPUT_STRIP_TRAILING_WHITESPACE
 )
 
 add_custom_command(OUTPUT ${GENERATED_FILES_LIST}

README.md

@@ -2,11 +2,16 @@
 
 > **Warning**
 >
-> This repository's `master` branch is only usable with the latest version of
-> Godot's ([GDExtension](https://godotengine.org/article/introducing-gd-extensions))
-> API (Godot 4.1 and later).
+> This repository's `master` branch is only usable with
+> [GDExtension](https://godotengine.org/article/introducing-gd-extensions)
+> from Godot's `master` branch.
 >
-> For users of Godot 4.0.x, switch to the [`4.0`](https://github.com/godotengine/godot-cpp/tree/4.0) branch.
+> For users of stable branches, switch to the branch matching your target Godot version:
+> - [`4.2`](https://github.com/godotengine/godot-cpp/tree/4.2)
+> - [`4.1`](https://github.com/godotengine/godot-cpp/tree/4.1)
+> - [`4.0`](https://github.com/godotengine/godot-cpp/tree/4.0)
+>
+> Or check out the Git tag matching your Godot version (e.g. `godot-4.1.1-stable`).
 >
 > For GDNative users (Godot 3.x), switch to the [`3.x`](https://github.com/godotengine/godot-cpp/tree/3.x)
 > or the [`3.5`](https://github.com/godotengine/godot-cpp/tree/3.5) branch.
@@ -52,9 +57,10 @@ first-party `godot-cpp` extension.
 
 Some compatibility breakage is to be expected as GDExtension and `godot-cpp`
 get more used, documented, and critical issues get resolved. See the
-[issue tracker](https://github.com/godotengine/godot/issues) for a list of known
-issues, and be sure to provide feedback on issues and PRs which affect your use
-of this extension.
+[Godot issue tracker](https://github.com/godotengine/godot/issues?q=is%3Aissue+is%3Aopen+label%3Atopic%3Agdextension)
+and the [godot-cpp issue tracker](https://github.com/godotengine/godot/issues)
+for a list of known issues, and be sure to provide feedback on issues and PRs
+which affect your use of this extension.
 
 ## Contributing
 
@@ -76,22 +82,22 @@ just like before.
 
 To use the shared lib in your Godot project you'll need a `.gdextension`
 file, which replaces what was the `.gdnlib` before.
-Follow [the example](test/demo/example.gdextension):
+See [example.gdextension](test/project/example.gdextension) used in the test project:
 
 ```ini
 [configuration]
 
 entry_symbol = "example_library_init"
-compatibility_minimum = 4.1
+compatibility_minimum = "4.1"
 
 [libraries]
 
-macos.debug = "bin/libgdexample.macos.debug.framework"
-macos.release = "bin/libgdexample.macos.release.framework"
-windows.debug.x86_64 = "bin/libgdexample.windows.debug.x86_64.dll"
-windows.release.x86_64 = "bin/libgdexample.windows.release.x86_64.dll"
-linux.debug.x86_64 = "bin/libgdexample.linux.debug.x86_64.so"
-linux.release.x86_64 = "bin/libgdexample.linux.release.x86_64.so"
+macos.debug = "res://bin/libgdexample.macos.debug.framework"
+macos.release = "res://bin/libgdexample.macos.release.framework"
+windows.debug.x86_64 = "res://bin/libgdexample.windows.debug.x86_64.dll"
+windows.release.x86_64 = "res://bin/libgdexample.windows.release.x86_64.dll"
+linux.debug.x86_64 = "res://bin/libgdexample.linux.debug.x86_64.so"
+linux.release.x86_64 = "res://bin/libgdexample.linux.release.x86_64.so"
 # Repeat for other architectures to support arm64, rv64, etc.
 ```
 
@@ -129,6 +135,10 @@ void initialize_example_module(ModuleInitializationLevel p_level) {
 
 Any node and resource you register will be available in the corresponding `Create...` dialog. Any class will be available to scripting as well.
 
-## Included example
+## Examples and templates
 
-Check the project in the `test` folder for an example on how to use and register different things.
+See the [godot-cpp-template](https://github.com/godotengine/godot-cpp-template) project for a
+generic reusable template.
+
+Or checkout the code for the [Summator example](https://github.com/paddy-exe/GDExtensionSummator)
+as shown in the [official documentation](https://docs.godotengine.org/en/latest/tutorials/scripting/gdextension/gdextension_cpp_example.html).

SConstruct

@@ -5,77 +5,26 @@ import platform
 import sys
 import subprocess
 from binding_generator import scons_generate_bindings, scons_emit_files
-from SCons.Errors import UserError
+
 
 EnsureSConsVersion(4, 0)
 
 
-def add_sources(sources, dir, extension):
-    for f in os.listdir(dir):
-        if f.endswith("." + extension):
-            sources.append(dir + "/" + f)
+try:
+    Import("env")
+except:
+    # Default tools with no platform defaults to gnu toolchain.
+    # We apply platform specific toolchains via our custom tools.
+    env = Environment(tools=["default"], PLATFORM="")
 
-
-def normalize_path(val):
-    return val if os.path.isabs(val) else os.path.join(env.Dir("#").abspath, val)
-
-
-def validate_api_file(key, val, env):
-    if not os.path.isfile(normalize_path(val)):
-        raise UserError("GDExtension API file ('%s') does not exist: %s" % (key, val))
-
-
-def validate_gdextension_dir(key, val, env):
-    if not os.path.isdir(normalize_path(val)):
-        raise UserError("GDExtension directory ('%s') does not exist: %s" % (key, val))
-
-
-def get_gdextension_dir(env):
-    return normalize_path(env.get("gdextension_dir", env.Dir("gdextension").abspath))
-
-
-def get_api_file(env):
-    return normalize_path(env.get("custom_api_file", os.path.join(get_gdextension_dir(env), "extension_api.json")))
-
-
-# Try to detect the host platform automatically.
-# This is used if no `platform` argument is passed
-if sys.platform.startswith("linux"):
-    default_platform = "linux"
-elif sys.platform == "darwin":
-    default_platform = "macos"
-elif sys.platform == "win32" or sys.platform == "msys":
-    default_platform = "windows"
-elif ARGUMENTS.get("platform", ""):
-    default_platform = ARGUMENTS.get("platform")
-else:
-    raise ValueError("Could not detect platform automatically, please specify with platform=<platform>")
-
-# Default tools with no platform defaults to gnu toolchain.
-# We apply platform specific toolchains via our custom tools.
-env = Environment(tools=["default"], PLATFORM="")
 env.PrependENVPath("PATH", os.getenv("PATH"))
 
-# Default num_jobs to local cpu count if not user specified.
-# SCons has a peculiarity where user-specified options won't be overridden
-# by SetOption, so we can rely on this to know if we should use our default.
-initial_num_jobs = env.GetOption("num_jobs")
-altered_num_jobs = initial_num_jobs + 1
-env.SetOption("num_jobs", altered_num_jobs)
-if env.GetOption("num_jobs") == altered_num_jobs:
-    cpu_count = os.cpu_count()
-    if cpu_count is None:
-        print("Couldn't auto-detect CPU count to configure build parallelism. Specify it with the -j argument.")
-    else:
-        safer_cpu_count = cpu_count if cpu_count <= 4 else cpu_count - 1
-        print(
-            "Auto-detected %d CPU cores available for build parallelism. Using %d cores by default. You can override it with the -j argument."
-            % (cpu_count, safer_cpu_count)
-        )
-        env.SetOption("num_jobs", safer_cpu_count)
-
 # Custom options and profile flags.
 customs = ["custom.py"]
+try:
+    customs += Import("customs")
+except:
+    pass
 profile = ARGUMENTS.get("profile", "")
 if profile:
     if os.path.isfile(profile):
@@ -83,113 +32,12 @@ if profile:
     elif os.path.isfile(profile + ".py"):
         customs.append(profile + ".py")
 opts = Variables(customs, ARGUMENTS)
-
-platforms = ("linux", "macos", "windows", "android", "ios", "javascript")
-opts.Add(
-    EnumVariable(
-        "platform",
-        "Target platform",
-        default_platform,
-        allowed_values=platforms,
-        ignorecase=2,
-    )
-)
-
-# Editor and template_debug are compatible (i.e. you can use the same binary for Godot editor builds and Godot debug templates).
-# Godot release templates are only compatible with "template_release" builds.
-# For this reason, we default to template_debug builds, unlike Godot which defaults to editor builds.
-opts.Add(
-    EnumVariable("target", "Compilation target", "template_debug", ("editor", "template_release", "template_debug"))
-)
-opts.Add(
-    PathVariable(
-        "gdextension_dir",
-        "Path to a custom directory containing GDExtension interface header and API JSON file",
-        None,
-        validate_gdextension_dir,
-    )
-)
-opts.Add(
-    PathVariable(
-        "custom_api_file",
-        "Path to a custom GDExtension API JSON file (takes precedence over `gdextension_dir`)",
-        None,
-        validate_api_file,
-    )
-)
-opts.Add(
-    BoolVariable("generate_bindings", "Force GDExtension API bindings generation. Auto-detected by default.", False)
-)
-opts.Add(BoolVariable("generate_template_get_node", "Generate a template version of the Node class's get_node.", True))
-
-opts.Add(BoolVariable("build_library", "Build the godot-cpp library.", True))
-opts.Add(EnumVariable("precision", "Set the floating-point precision level", "single", ("single", "double")))
-
-# Add platform options
-tools = {}
-for pl in platforms:
-    tool = Tool(pl, toolpath=["tools"])
-    if hasattr(tool, "options"):
-        tool.options(opts)
-    tools[pl] = tool
-
-# CPU architecture options.
-architecture_array = ["", "universal", "x86_32", "x86_64", "arm32", "arm64", "rv64", "ppc32", "ppc64", "wasm32"]
-architecture_aliases = {
-    "x64": "x86_64",
-    "amd64": "x86_64",
-    "armv7": "arm32",
-    "armv8": "arm64",
-    "arm64v8": "arm64",
-    "aarch64": "arm64",
-    "rv": "rv64",
-    "riscv": "rv64",
-    "riscv64": "rv64",
-    "ppcle": "ppc32",
-    "ppc": "ppc32",
-    "ppc64le": "ppc64",
-}
-opts.Add(EnumVariable("arch", "CPU architecture", "", architecture_array, architecture_aliases))
-
-# Targets flags tool (optimizations, debug symbols)
-target_tool = Tool("targets", toolpath=["tools"])
-target_tool.options(opts)
-
+cpp_tool = Tool("godotcpp", toolpath=["tools"])
+cpp_tool.options(opts, env)
 opts.Update(env)
+
 Help(opts.GenerateHelpText(env))
 
-# Process CPU architecture argument.
-if env["arch"] == "":
-    # No architecture specified. Default to arm64 if building for Android,
-    # universal if building for macOS or iOS, wasm32 if building for web,
-    # otherwise default to the host architecture.
-    if env["platform"] in ["macos", "ios"]:
-        env["arch"] = "universal"
-    elif env["platform"] == "android":
-        env["arch"] = "arm64"
-    elif env["platform"] == "javascript":
-        env["arch"] = "wasm32"
-    else:
-        host_machine = platform.machine().lower()
-        if host_machine in architecture_array:
-            env["arch"] = host_machine
-        elif host_machine in architecture_aliases.keys():
-            env["arch"] = architecture_aliases[host_machine]
-        elif "86" in host_machine:
-            # Catches x86, i386, i486, i586, i686, etc.
-            env["arch"] = "x86_32"
-        else:
-            print("Unsupported CPU architecture: " + host_machine)
-            Exit()
-
-tool = Tool(env["platform"], toolpath=["tools"])
-
-if tool is None or not tool.exists(env):
-    raise ValueError("Required toolchain not found for platform " + env["platform"])
-
-tool.generate(env)
-target_tool.generate(env)
-
 # Detect and print a warning listing unknown SCons variables to ease troubleshooting.
 unknown = opts.UnknownVariables()
 if unknown:
@@ -197,66 +45,12 @@ if unknown:
     for item in unknown.items():
         print("    " + item[0] + "=" + item[1])
 
-print("Building for architecture " + env["arch"] + " on platform " + env["platform"])
-
-# Require C++17
-if env.get("is_msvc", False):
-    env.Append(CXXFLAGS=["/std:c++17"])
-else:
-    env.Append(CXXFLAGS=["-std=c++17"])
-
-if env["precision"] == "double":
-    env.Append(CPPDEFINES=["REAL_T_IS_DOUBLE"])
-
-# Generate bindings
-env.Append(BUILDERS={"GenerateBindings": Builder(action=scons_generate_bindings, emitter=scons_emit_files)})
-
-bindings = env.GenerateBindings(
-    env.Dir("."),
-    [get_api_file(env), os.path.join(get_gdextension_dir(env), "gdextension_interface.h"), "binding_generator.py"],
-)
-
 scons_cache_path = os.environ.get("SCONS_CACHE")
 if scons_cache_path is not None:
     CacheDir(scons_cache_path)
     Decider("MD5")
 
-# Forces bindings regeneration.
-if env["generate_bindings"]:
-    AlwaysBuild(bindings)
-    NoCache(bindings)
+cpp_tool.generate(env)
+library = env.GodotCPP()
 
-# Includes
-env.Append(CPPPATH=[[env.Dir(d) for d in [get_gdextension_dir(env), "include", os.path.join("gen", "include")]]])
-
-# Sources to compile
-sources = []
-add_sources(sources, "src", "cpp")
-add_sources(sources, "src/classes", "cpp")
-add_sources(sources, "src/core", "cpp")
-add_sources(sources, "src/variant", "cpp")
-sources.extend([f for f in bindings if str(f).endswith(".cpp")])
-
-suffix = ".{}.{}".format(env["platform"], env["target"])
-if env.dev_build:
-    suffix += ".dev"
-if env["precision"] == "double":
-    suffix += ".double"
-suffix += "." + env["arch"]
-if env["ios_simulator"]:
-    suffix += ".simulator"
-
-# Expose it when included from another project
-env["suffix"] = suffix
-
-library = None
-env["OBJSUFFIX"] = suffix + env["OBJSUFFIX"]
-library_name = "libgodot-cpp{}{}".format(suffix, env["LIBSUFFIX"])
-
-if env["build_library"]:
-    library = env.StaticLibrary(target=env.File("bin/%s" % library_name), source=sources)
-    Default(library)
-
-env.Append(LIBPATH=[env.Dir("bin")])
-env.Append(LIBS=library_name)
 Return("env")

binding_generator.py

@@ -97,9 +97,10 @@ 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"
+            engine_class["alias_for"] = "ClassDB"
         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:
@@ -109,6 +110,8 @@ def get_file_list(api_filepath, output_dir, headers=False, sources=False):
 
     for native_struct in api["native_structures"]:
         struct_name = native_struct["name"]
+        if struct_name == "ObjectID":
+            continue
         snake_struct_name = camel_to_snake(struct_name)
 
         header_filename = include_gen_folder / "classes" / (snake_struct_name + ".hpp")
@@ -121,23 +124,21 @@ def get_file_list(api_filepath, output_dir, headers=False, sources=False):
             include_gen_folder / "variant" / "builtin_binds.hpp",
             include_gen_folder / "variant" / "utility_functions.hpp",
             include_gen_folder / "variant" / "variant_size.hpp",
+            include_gen_folder / "variant" / "builtin_vararg_methods.hpp",
             include_gen_folder / "classes" / "global_constants.hpp",
             include_gen_folder / "classes" / "global_constants_binds.hpp",
+            include_gen_folder / "core" / "version.hpp",
         ]:
             files.append(str(path.as_posix()))
     if sources:
         utility_functions_source_path = source_gen_folder / "variant" / "utility_functions.cpp"
         files.append(str(utility_functions_source_path.as_posix()))
-        register_engine_classes_source_path = source_gen_folder / "register_engine_classes.cpp"
-        files.append(str(register_engine_classes_source_path.as_posix()))
 
     return files
 
 
 def print_file_list(api_filepath, output_dir, headers=False, sources=False):
-    end = ";"
-    for f in get_file_list(api_filepath, output_dir, headers, sources):
-        print(f, end=end)
+    print(*get_file_list(api_filepath, output_dir, headers, sources), sep=";", end=None)
 
 
 def scons_emit_files(target, source, env):
@@ -173,6 +174,7 @@ def generate_bindings(api_filepath, use_template_get_node, bits="64", precision=
     print("Built-in type config: " + real_t + "_" + bits)
 
     generate_global_constants(api, target_dir)
+    generate_version_header(api, target_dir)
     generate_global_constant_binds(api, target_dir)
     generate_builtin_bindings(api, target_dir, real_t + "_" + bits)
     generate_engine_classes_bindings(api, target_dir, use_template_get_node)
@@ -344,6 +346,40 @@ def generate_builtin_bindings(api, output_dir, build_config):
 
         builtin_binds_file.write("\n".join(builtin_binds))
 
+    # Create a header to implement all builtin class vararg methods and be included in "variant.hpp".
+    builtin_vararg_methods_header = include_gen_folder / "builtin_vararg_methods.hpp"
+    builtin_vararg_methods_header.open("w+").write(
+        generate_builtin_class_vararg_method_implements_header(api["builtin_classes"])
+    )
+
+
+def generate_builtin_class_vararg_method_implements_header(builtin_classes):
+    result = []
+
+    add_header("builtin_vararg_methods.hpp", result)
+
+    header_guard = "GODOT_CPP_BUILTIN_VARARG_METHODS_HPP"
+    result.append(f"#ifndef {header_guard}")
+    result.append(f"#define {header_guard}")
+    result.append("")
+    for builtin_api in builtin_classes:
+        if not "methods" in builtin_api:
+            continue
+        class_name = builtin_api["name"]
+        for method in builtin_api["methods"]:
+            if not method["is_vararg"]:
+                continue
+
+            result += make_varargs_template(
+                method, "is_static" in method and method["is_static"], class_name, False, False, True
+            )
+            result.append("")
+
+    result.append("")
+    result.append(f"#endif // ! {header_guard}")
+
+    return "\n".join(result)
+
 
 def generate_builtin_class_header(builtin_api, size, used_classes, fully_used_classes):
     result = []
@@ -366,6 +402,7 @@ def generate_builtin_class_header(builtin_api, size, used_classes, fully_used_cl
     if class_name == "String":
         result.append("#include <godot_cpp/variant/char_string.hpp>")
         result.append("#include <godot_cpp/variant/char_utils.hpp>")
+        result.append("#include <godot_cpp/classes/global_constants.hpp>")
 
     if class_name == "PackedStringArray":
         result.append("#include <godot_cpp/variant/string.hpp>")
@@ -379,6 +416,9 @@ def generate_builtin_class_header(builtin_api, size, used_classes, fully_used_cl
     if class_name == "Array":
         result.append("#include <godot_cpp/variant/array_helpers.hpp>")
 
+    if class_name == "Callable":
+        result.append("#include <godot_cpp/variant/callable_custom.hpp>")
+
     for include in fully_used_classes:
         if include == "TypedArray":
             result.append("#include <godot_cpp/variant/typed_array.hpp>")
@@ -481,10 +521,16 @@ def generate_builtin_class_header(builtin_api, size, used_classes, fully_used_cl
 
     # Special cases.
     if class_name == "String" or class_name == "StringName" or class_name == "NodePath":
-        result.append(f"\t{class_name}(const char *from);")
+        if class_name == "StringName":
+            result.append(f"\t{class_name}(const char *from, bool p_static = false);")
+        else:
+            result.append(f"\t{class_name}(const char *from);")
         result.append(f"\t{class_name}(const wchar_t *from);")
         result.append(f"\t{class_name}(const char16_t *from);")
         result.append(f"\t{class_name}(const char32_t *from);")
+    if class_name == "Callable":
+        result.append("\tCallable(CallableCustom *p_custom);")
+        result.append("\tCallableCustom *get_custom() const;")
 
     if "constants" in builtin_api:
         axis_constants_count = 0
@@ -552,6 +598,7 @@ def generate_builtin_class_header(builtin_api, size, used_classes, fully_used_cl
         result.append("\tChar32String utf32() const;")
         result.append("\tCharWideString wide_string() const;")
         result.append("\tstatic String num_real(double p_num, bool p_trailing = true);")
+        result.append("\tError resize(int p_size);")
 
     if "members" in builtin_api:
         for member in builtin_api["members"]:
@@ -1036,21 +1083,25 @@ 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"
+            class_api["alias_for"] = "ClassDB"
         engine_classes[class_api["name"]] = class_api["is_refcounted"]
     for native_struct in api["native_structures"]:
+        if native_struct["name"] == "ObjectID":
+            continue
         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"
+            singleton["alias_for"] = "ClassDB"
         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()
@@ -1140,6 +1191,12 @@ def generate_engine_classes_bindings(api, output_dir, use_template_get_node):
         else:
             fully_used_classes.add("Wrapped")
 
+        # In order to ensure that PtrToArg specializations for native structs are
+        # always used, let's move any of them into 'fully_used_classes'.
+        for type_name in used_classes:
+            if is_struct_type(type_name) and not is_included_struct_type(type_name):
+                fully_used_classes.add(type_name)
+
         for type_name in fully_used_classes:
             if type_name in used_classes:
                 used_classes.remove(type_name)
@@ -1159,12 +1216,10 @@ def generate_engine_classes_bindings(api, output_dir, use_template_get_node):
                 generate_engine_class_source(class_api, used_classes, fully_used_classes, use_template_get_node)
             )
 
-    register_engine_classes_filename = Path(output_dir) / "src" / "register_engine_classes.cpp"
-    with register_engine_classes_filename.open("w+", encoding="utf-8") as source_file:
-        source_file.write(generate_register_engine_classes_source(api))
-
     for native_struct in api["native_structures"]:
         struct_name = native_struct["name"]
+        if struct_name == "ObjectID":
+            continue
         snake_struct_name = camel_to_snake(struct_name)
 
         header_filename = include_gen_folder / (snake_struct_name + ".hpp")
@@ -1237,12 +1292,12 @@ def generate_engine_class_header(class_api, used_classes, fully_used_classes, us
             result.append(f"#include <godot_cpp/{get_include_path(included)}>")
 
     if class_name == "EditorPlugin":
-        result.append("#include <godot_cpp/templates/vector.hpp>")
+        result.append("#include <godot_cpp/classes/editor_plugin_registration.hpp>")
 
     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>")
@@ -1263,7 +1318,10 @@ def generate_engine_class_header(class_api, used_classes, fully_used_classes, us
     inherits = class_api["inherits"] if "inherits" in class_api else "Wrapped"
     result.append(f"class {class_name} : public {inherits} {{")
 
-    result.append(f"\tGDEXTENSION_CLASS({class_name}, {inherits})")
+    if "alias_for" in class_api:
+        result.append(f"\tGDEXTENSION_CLASS_ALIAS({class_name}, {class_api['alias_for']}, {inherits})")
+    else:
+        result.append(f"\tGDEXTENSION_CLASS({class_name}, {inherits})")
     result.append("")
 
     result.append("public:")
@@ -1271,7 +1329,11 @@ def generate_engine_class_header(class_api, used_classes, fully_used_classes, us
 
     if "enums" in class_api:
         for enum_api in class_api["enums"]:
-            result.append(f'\tenum {enum_api["name"]} {{')
+            if enum_api["is_bitfield"]:
+                result.append(f'\tenum {enum_api["name"]} : uint64_t {{')
+            else:
+                result.append(f'\tenum {enum_api["name"]} {{')
+
             for value in enum_api["values"]:
                 result.append(f'\t\t{value["name"]} = {value["value"]},')
             result.append("\t};")
@@ -1386,30 +1448,6 @@ def generate_engine_class_header(class_api, used_classes, fully_used_classes, us
     result.append("};")
     result.append("")
 
-    if class_name == "EditorPlugin":
-        result.append("class EditorPlugins {")
-        result.append("private:")
-        result.append("\tstatic Vector<StringName> plugin_classes;")
-        result.append("")
-        result.append("public:")
-        result.append("\tstatic void add_plugin_class(const StringName &p_class_name);")
-        result.append("\tstatic void remove_plugin_class(const StringName &p_class_name);")
-        result.append("\tstatic void deinitialize(GDExtensionInitializationLevel p_level);")
-        result.append("")
-
-        result.append("\ttemplate <class T>")
-        result.append("\tstatic void add_by_type() {")
-        result.append("\t\tadd_plugin_class(T::get_class_static());")
-        result.append("\t}")
-
-        result.append("\ttemplate <class T>")
-        result.append("\tstatic void remove_by_type() {")
-        result.append("\t\tremove_plugin_class(T::get_class_static());")
-        result.append("\t}")
-
-        result.append("};")
-        result.append("")
-
     result.append("} // namespace godot")
     result.append("")
 
@@ -1421,6 +1459,51 @@ 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"])} '
+            elif "return_value" in method:
+                method_signature += (
+                    correct_type(method["return_value"]["type"], method["return_value"].get("meta", None)) + " "
+                )
+            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 or "return_value" 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)
@@ -1453,16 +1536,22 @@ def generate_engine_class_source(class_api, used_classes, fully_used_classes, us
 
     if is_singleton:
         result.append(f"{class_name} *{class_name}::get_singleton() {{")
-        result.append(f"\tconst StringName _gde_class_name = {class_name}::get_class_static();")
+        # We assume multi-threaded access is OK because each assignment will assign the same value every time
+        result.append(f"\tstatic {class_name} *singleton = nullptr;")
+        result.append("\tif (unlikely(singleton == nullptr)) {")
         result.append(
-            "\tstatic GDExtensionObjectPtr singleton_obj = internal::gdextension_interface_global_get_singleton(_gde_class_name._native_ptr());"
+            f"\t\tGDExtensionObjectPtr singleton_obj = internal::gdextension_interface_global_get_singleton({class_name}::get_class_static()._native_ptr());"
         )
         result.append("#ifdef DEBUG_ENABLED")
-        result.append("\tERR_FAIL_COND_V(singleton_obj == nullptr, nullptr);")
+        result.append("\t\tERR_FAIL_NULL_V(singleton_obj, nullptr);")
         result.append("#endif // DEBUG_ENABLED")
         result.append(
-            f"\tstatic {class_name} *singleton = reinterpret_cast<{class_name} *>(internal::gdextension_interface_object_get_instance_binding(singleton_obj, internal::token, &{class_name}::_gde_binding_callbacks));"
+            f"\t\tsingleton = reinterpret_cast<{class_name} *>(internal::gdextension_interface_object_get_instance_binding(singleton_obj, internal::token, &{class_name}::_gde_binding_callbacks));"
         )
+        result.append("#ifdef DEBUG_ENABLED")
+        result.append("\t\tERR_FAIL_NULL_V(singleton, nullptr);")
+        result.append("#endif // DEBUG_ENABLED")
+        result.append("\t}")
         result.append("\treturn singleton;")
         result.append("}")
         result.append("")
@@ -1480,10 +1569,8 @@ def generate_engine_class_source(class_api, used_classes, fully_used_classes, us
             result.append(method_signature + " {")
 
             # Method body.
-            result.append(f"\tconst StringName _gde_class_name = {class_name}::get_class_static();")
-            result.append(f'\tconst StringName _gde_method_name = "{method["name"]}";')
             result.append(
-                f'\tstatic GDExtensionMethodBindPtr _gde_method_bind = internal::gdextension_interface_classdb_get_method_bind(_gde_class_name._native_ptr(), _gde_method_name._native_ptr(), {method["hash"]});'
+                f'\tstatic GDExtensionMethodBindPtr _gde_method_bind = internal::gdextension_interface_classdb_get_method_bind({class_name}::get_class_static()._native_ptr(), StringName("{method["name"]}")._native_ptr(), {method["hash"]});'
             )
             method_call = "\t"
             has_return = "return_value" in method and method["return_value"]["type"] != "void"
@@ -1585,38 +1672,6 @@ def generate_engine_class_source(class_api, used_classes, fully_used_classes, us
     return "\n".join(result)
 
 
-def generate_register_engine_classes_source(api):
-    includes = []
-    registrations = []
-
-    for class_api in api["classes"]:
-        if class_api["name"] == "ClassDB":
-            continue
-
-        class_name = class_api["name"]
-        snake_class_name = camel_to_snake(class_name)
-
-        includes.append(f"#include <godot_cpp/classes/{snake_class_name}.hpp>")
-        registrations.append(f"\tClassDB::register_engine_class<{class_name}>();")
-
-    result = []
-    add_header(f"register_engine_classes.cpp", result)
-
-    result.append("#include <godot_cpp/godot.hpp>")
-    result.append("")
-    result = result + includes
-    result.append("")
-    result.append("namespace godot {")
-    result.append("")
-    result.append("void GDExtensionBinding::register_engine_classes() {")
-    result = result + registrations
-    result.append("}")
-    result.append("")
-    result.append("} // namespace godot ")
-
-    return "\n".join(result)
-
-
 def generate_global_constants(api, output_dir):
     include_gen_folder = Path(output_dir) / "include" / "godot_cpp" / "classes"
     source_gen_folder = Path(output_dir) / "src" / "classes"
@@ -1635,6 +1690,8 @@ def generate_global_constants(api, output_dir):
     header.append(f"#ifndef {header_guard}")
     header.append(f"#define {header_guard}")
     header.append("")
+    header.append("#include <cstdint>")
+    header.append("")
     header.append("namespace godot {")
     header.append("")
 
@@ -1647,7 +1704,11 @@ def generate_global_constants(api, output_dir):
         if enum_def["name"].startswith("Variant."):
             continue
 
-        header.append(f'\tenum {enum_def["name"]} {{')
+        if enum_def["is_bitfield"]:
+            header.append(f'\tenum {enum_def["name"]} : uint64_t {{')
+        else:
+            header.append(f'\tenum {enum_def["name"]} {{')
+
         for value in enum_def["values"]:
             header.append(f'\t\t{value["name"]} = {value["value"]},')
         header.append("\t};")
@@ -1662,6 +1723,35 @@ def generate_global_constants(api, output_dir):
         header_file.write("\n".join(header))
 
 
+def generate_version_header(api, output_dir):
+    header = []
+    header_filename = "version.hpp"
+    add_header(header_filename, header)
+
+    include_gen_folder = Path(output_dir) / "include" / "godot_cpp" / "core"
+    include_gen_folder.mkdir(parents=True, exist_ok=True)
+
+    header_file_path = include_gen_folder / header_filename
+
+    header_guard = "GODOT_CPP_VERSION_HPP"
+    header.append(f"#ifndef {header_guard}")
+    header.append(f"#define {header_guard}")
+    header.append("")
+
+    header.append(f"#define GODOT_VERSION_MAJOR {api['header']['version_major']}")
+    header.append(f"#define GODOT_VERSION_MINOR {api['header']['version_minor']}")
+    header.append(f"#define GODOT_VERSION_PATCH {api['header']['version_patch']}")
+    header.append(f"#define GODOT_VERSION_STATUS \"{api['header']['version_status']}\"")
+    header.append(f"#define GODOT_VERSION_BUILD \"{api['header']['version_build']}\"")
+
+    header.append("")
+    header.append(f"#endif // {header_guard}")
+    header.append("")
+
+    with header_file_path.open("w+", encoding="utf-8") as header_file:
+        header_file.write("\n".join(header))
+
+
 def generate_global_constant_binds(api, output_dir):
     include_gen_folder = Path(output_dir) / "include" / "godot_cpp" / "classes"
     source_gen_folder = Path(output_dir) / "src" / "classes"
@@ -1773,9 +1863,8 @@ def generate_utility_functions(api, output_dir):
 
         # Function body.
 
-        source.append(f'\tconst StringName _gde_function_name = "{function["name"]}";')
         source.append(
-            f'\tstatic GDExtensionPtrUtilityFunction _gde_function = internal::gdextension_interface_variant_get_ptr_utility_function(_gde_function_name._native_ptr(), {function["hash"]});'
+            f'\tstatic GDExtensionPtrUtilityFunction _gde_function = internal::gdextension_interface_variant_get_ptr_utility_function(StringName("{function["name"]}")._native_ptr(), {function["hash"]});'
         )
         has_return = "return_type" in function and function["return_type"] != "void"
         if has_return:
@@ -1969,10 +2058,22 @@ def make_signature(
     return function_signature
 
 
-def make_varargs_template(function_data, static=False):
+def make_varargs_template(
+    function_data,
+    static=False,
+    class_befor_signature="",
+    with_public_declare=True,
+    with_indent=True,
+    for_builtin_classes=False,
+):
     result = []
 
-    function_signature = "\tpublic: template<class... Args> "
+    function_signature = ""
+
+    if with_public_declare:
+        function_signature = "public: "
+
+    function_signature += "template<class... Args> "
 
     if static:
         function_signature += "static "
@@ -1993,6 +2094,8 @@ def make_varargs_template(function_data, static=False):
     if not function_signature.endswith("*"):
         function_signature += " "
 
+    if len(class_befor_signature) > 0:
+        function_signature += class_befor_signature + "::"
     function_signature += f'{escape_identifier(function_data["name"])}'
 
     method_arguments = []
@@ -2013,7 +2116,7 @@ def make_varargs_template(function_data, static=False):
     function_signature += " {"
     result.append(function_signature)
 
-    args_array = f"\t\tstd::array<Variant, {len(method_arguments)} + sizeof...(Args)> variant_args {{ "
+    args_array = f"\tstd::array<Variant, {len(method_arguments)} + sizeof...(Args)> variant_args {{ "
     for argument in method_arguments:
         if argument["type"] == "Variant":
             args_array += argument["name"]
@@ -2023,20 +2126,43 @@ def make_varargs_template(function_data, static=False):
 
     args_array += "Variant(args)... };"
     result.append(args_array)
-    result.append(f"\t\tstd::array<const Variant *, {len(method_arguments)} + sizeof...(Args)> call_args;")
-    result.append("\t\tfor(size_t i = 0; i < variant_args.size(); i++) {")
-    result.append("\t\t\tcall_args[i] = &variant_args[i];")
-    result.append("\t\t}")
-
-    call_line = "\t\t"
-
-    if return_type != "void":
-        call_line += "return "
-
-    call_line += f'{escape_identifier(function_data["name"])}_internal(call_args.data(), variant_args.size());'
-    result.append(call_line)
+    result.append(f"\tstd::array<const Variant *, {len(method_arguments)} + sizeof...(Args)> call_args;")
+    result.append("\tfor(size_t i = 0; i < variant_args.size(); i++) {")
+    result.append("\t\tcall_args[i] = &variant_args[i];")
     result.append("\t}")
 
+    call_line = "\t"
+
+    if not for_builtin_classes:
+        if return_type != "void":
+            call_line += "return "
+
+        call_line += f'{escape_identifier(function_data["name"])}_internal(call_args.data(), variant_args.size());'
+        result.append(call_line)
+    else:
+        base = "(GDExtensionTypePtr)&opaque"
+        if static:
+            base = "nullptr"
+
+        ret = "nullptr"
+        if return_type != "void":
+            ret = "&ret"
+            result.append(f'\t{correct_type(function_data["return_type"])} ret;')
+
+        function_name = function_data["name"]
+        result.append(
+            f"\t_method_bindings.method_{function_name}({base}, reinterpret_cast<GDExtensionConstTypePtr *>(call_args.data()), {ret}, {len(method_arguments)} + sizeof...(Args));"
+        )
+
+        if return_type != "void":
+            result.append("\treturn ret;")
+
+    result.append("}")
+
+    if with_indent:
+        for i in range(len(result)):
+            result[i] = "\t" + result[i]
+
     return result
 
 
@@ -2285,6 +2411,7 @@ 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]

gdextension/gdextension_interface.h

@@ -258,14 +258,19 @@ typedef const GDExtensionPropertyInfo *(*GDExtensionClassGetPropertyList)(GDExte
 typedef void (*GDExtensionClassFreePropertyList)(GDExtensionClassInstancePtr p_instance, const GDExtensionPropertyInfo *p_list);
 typedef GDExtensionBool (*GDExtensionClassPropertyCanRevert)(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name);
 typedef GDExtensionBool (*GDExtensionClassPropertyGetRevert)(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionVariantPtr r_ret);
-typedef void (*GDExtensionClassNotification)(GDExtensionClassInstancePtr p_instance, int32_t p_what);
+typedef GDExtensionBool (*GDExtensionClassValidateProperty)(GDExtensionClassInstancePtr p_instance, GDExtensionPropertyInfo *p_property);
+typedef void (*GDExtensionClassNotification)(GDExtensionClassInstancePtr p_instance, int32_t p_what); // Deprecated. Use GDExtensionClassNotification2 instead.
+typedef void (*GDExtensionClassNotification2)(GDExtensionClassInstancePtr p_instance, int32_t p_what, GDExtensionBool p_reversed);
 typedef void (*GDExtensionClassToString)(GDExtensionClassInstancePtr p_instance, GDExtensionBool *r_is_valid, GDExtensionStringPtr p_out);
 typedef void (*GDExtensionClassReference)(GDExtensionClassInstancePtr p_instance);
 typedef void (*GDExtensionClassUnreference)(GDExtensionClassInstancePtr p_instance);
 typedef void (*GDExtensionClassCallVirtual)(GDExtensionClassInstancePtr p_instance, const GDExtensionConstTypePtr *p_args, GDExtensionTypePtr r_ret);
-typedef GDExtensionObjectPtr (*GDExtensionClassCreateInstance)(void *p_userdata);
-typedef void (*GDExtensionClassFreeInstance)(void *p_userdata, GDExtensionClassInstancePtr p_instance);
-typedef GDExtensionClassCallVirtual (*GDExtensionClassGetVirtual)(void *p_userdata, GDExtensionConstStringNamePtr p_name);
+typedef GDExtensionObjectPtr (*GDExtensionClassCreateInstance)(void *p_class_userdata);
+typedef void (*GDExtensionClassFreeInstance)(void *p_class_userdata, GDExtensionClassInstancePtr p_instance);
+typedef GDExtensionClassInstancePtr (*GDExtensionClassRecreateInstance)(void *p_class_userdata, GDExtensionObjectPtr p_object);
+typedef GDExtensionClassCallVirtual (*GDExtensionClassGetVirtual)(void *p_class_userdata, GDExtensionConstStringNamePtr p_name);
+typedef void *(*GDExtensionClassGetVirtualCallData)(void *p_class_userdata, GDExtensionConstStringNamePtr p_name);
+typedef void (*GDExtensionClassCallVirtualWithData)(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name, void *p_virtual_call_userdata, const GDExtensionConstTypePtr *p_args, GDExtensionTypePtr r_ret);
 
 typedef struct {
 	GDExtensionBool is_virtual;
@@ -285,7 +290,40 @@ typedef struct {
 	GDExtensionClassGetVirtual get_virtual_func; // Queries a virtual function by name and returns a callback to invoke the requested virtual function.
 	GDExtensionClassGetRID get_rid_func;
 	void *class_userdata; // Per-class user data, later accessible in instance bindings.
-} GDExtensionClassCreationInfo;
+} GDExtensionClassCreationInfo; // Deprecated. Use GDExtensionClassCreationInfo2 instead.
+
+typedef struct {
+	GDExtensionBool is_virtual;
+	GDExtensionBool is_abstract;
+	GDExtensionBool is_exposed;
+	GDExtensionClassSet set_func;
+	GDExtensionClassGet get_func;
+	GDExtensionClassGetPropertyList get_property_list_func;
+	GDExtensionClassFreePropertyList free_property_list_func;
+	GDExtensionClassPropertyCanRevert property_can_revert_func;
+	GDExtensionClassPropertyGetRevert property_get_revert_func;
+	GDExtensionClassValidateProperty validate_property_func;
+	GDExtensionClassNotification2 notification_func;
+	GDExtensionClassToString to_string_func;
+	GDExtensionClassReference reference_func;
+	GDExtensionClassUnreference unreference_func;
+	GDExtensionClassCreateInstance create_instance_func; // (Default) constructor; mandatory. If the class is not instantiable, consider making it virtual or abstract.
+	GDExtensionClassFreeInstance free_instance_func; // Destructor; mandatory.
+	GDExtensionClassRecreateInstance recreate_instance_func;
+	// Queries a virtual function by name and returns a callback to invoke the requested virtual function.
+	GDExtensionClassGetVirtual get_virtual_func;
+	// Paired with `call_virtual_with_data_func`, this is an alternative to `get_virtual_func` for extensions that
+	// need or benefit from extra data when calling virtual functions.
+	// Returns user data that will be passed to `call_virtual_with_data_func`.
+	// Returning `NULL` from this function signals to Godot that the virtual function is not overridden.
+	// Data returned from this function should be managed by the extension and must be valid until the extension is deinitialized.
+	// You should supply either `get_virtual_func`, or `get_virtual_call_data_func` with `call_virtual_with_data_func`.
+	GDExtensionClassGetVirtualCallData get_virtual_call_data_func;
+	// Used to call virtual functions when `get_virtual_call_data_func` is not null.
+	GDExtensionClassCallVirtualWithData call_virtual_with_data_func;
+	GDExtensionClassGetRID get_rid_func;
+	void *class_userdata; // Per-class user data, later accessible in instance bindings.
+} GDExtensionClassCreationInfo2;
 
 typedef void *GDExtensionClassLibraryPtr;
 
@@ -343,6 +381,47 @@ typedef struct {
 	GDExtensionVariantPtr *default_arguments;
 } GDExtensionClassMethodInfo;
 
+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);
+
+typedef uint32_t (*GDExtensionCallableCustomHash)(void *callable_userdata);
+typedef GDExtensionBool (*GDExtensionCallableCustomEqual)(void *callable_userdata_a, void *callable_userdata_b);
+typedef GDExtensionBool (*GDExtensionCallableCustomLessThan)(void *callable_userdata_a, void *callable_userdata_b);
+
+typedef void (*GDExtensionCallableCustomToString)(void *callable_userdata, GDExtensionBool *r_is_valid, GDExtensionStringPtr r_out);
+
+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;
+} GDExtensionCallableCustomInfo;
+
 /* SCRIPT INSTANCE EXTENSION */
 
 typedef void *GDExtensionScriptInstanceDataPtr; // Pointer to custom ScriptInstance native implementation.
@@ -351,7 +430,10 @@ typedef GDExtensionBool (*GDExtensionScriptInstanceSet)(GDExtensionScriptInstanc
 typedef GDExtensionBool (*GDExtensionScriptInstanceGet)(GDExtensionScriptInstanceDataPtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionVariantPtr r_ret);
 typedef const GDExtensionPropertyInfo *(*GDExtensionScriptInstanceGetPropertyList)(GDExtensionScriptInstanceDataPtr p_instance, uint32_t *r_count);
 typedef void (*GDExtensionScriptInstanceFreePropertyList)(GDExtensionScriptInstanceDataPtr p_instance, const GDExtensionPropertyInfo *p_list);
+typedef GDExtensionBool (*GDExtensionScriptInstanceGetClassCategory)(GDExtensionScriptInstanceDataPtr p_instance, GDExtensionPropertyInfo *p_class_category);
+
 typedef GDExtensionVariantType (*GDExtensionScriptInstanceGetPropertyType)(GDExtensionScriptInstanceDataPtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionBool *r_is_valid);
+typedef GDExtensionBool (*GDExtensionScriptInstanceValidateProperty)(GDExtensionScriptInstanceDataPtr p_instance, GDExtensionPropertyInfo *p_property);
 
 typedef GDExtensionBool (*GDExtensionScriptInstancePropertyCanRevert)(GDExtensionScriptInstanceDataPtr p_instance, GDExtensionConstStringNamePtr p_name);
 typedef GDExtensionBool (*GDExtensionScriptInstancePropertyGetRevert)(GDExtensionScriptInstanceDataPtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionVariantPtr r_ret);
@@ -366,7 +448,8 @@ typedef void (*GDExtensionScriptInstanceFreeMethodList)(GDExtensionScriptInstanc
 typedef GDExtensionBool (*GDExtensionScriptInstanceHasMethod)(GDExtensionScriptInstanceDataPtr p_instance, GDExtensionConstStringNamePtr p_name);
 
 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);
+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);
 typedef void (*GDExtensionScriptInstanceToString)(GDExtensionScriptInstanceDataPtr p_instance, GDExtensionBool *r_is_valid, GDExtensionStringPtr r_out);
 
 typedef void (*GDExtensionScriptInstanceRefCountIncremented)(GDExtensionScriptInstanceDataPtr p_instance);
@@ -420,7 +503,48 @@ typedef struct {
 
 	GDExtensionScriptInstanceFree free_func;
 
-} GDExtensionScriptInstanceInfo;
+} GDExtensionScriptInstanceInfo; // Deprecated. Use GDExtensionScriptInstanceInfo2 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;
+
+	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;
+
+} GDExtensionScriptInstanceInfo2;
 
 /* INITIALIZATION */
 
@@ -466,7 +590,10 @@ typedef GDExtensionInterfaceFunctionPtr (*GDExtensionInterfaceGetProcAddress)(co
  *
  * For example:
  *
- *   GDExtensionInterfaceGetGodotVersion *get_godot_version = (GDExtensionInterfaceGetGodotVersion)p_get_proc_address("get_godot_version");
+ *   GDExtensionInterfaceGetGodotVersion get_godot_version = (GDExtensionInterfaceGetGodotVersion)p_get_proc_address("get_godot_version");
+ *
+ * (Note that snippet may cause "cast between incompatible function types" on some compilers, you can
+ * silence this by adding an intermediary `void*` cast.)
  *
  * You can then call it like a normal function:
  *
@@ -1313,7 +1440,7 @@ typedef void (*GDExtensionInterfaceStringNewWithWideChars)(GDExtensionUninitiali
  *
  * @param r_dest A pointer to a Variant to hold the newly created String.
  * @param p_contents A pointer to a Latin-1 encoded C string.
- * @param p_size The number of characters.
+ * @param p_size The number of characters (= number of bytes).
  */
 typedef void (*GDExtensionInterfaceStringNewWithLatin1CharsAndLen)(GDExtensionUninitializedStringPtr r_dest, const char *p_contents, GDExtensionInt p_size);
 
@@ -1325,7 +1452,7 @@ typedef void (*GDExtensionInterfaceStringNewWithLatin1CharsAndLen)(GDExtensionUn
  *
  * @param r_dest A pointer to a Variant to hold the newly created String.
  * @param p_contents A pointer to a UTF-8 encoded C string.
- * @param p_size The number of characters.
+ * @param p_size The number of bytes (not code units).
  */
 typedef void (*GDExtensionInterfaceStringNewWithUtf8CharsAndLen)(GDExtensionUninitializedStringPtr r_dest, const char *p_contents, GDExtensionInt p_size);
 
@@ -1337,9 +1464,9 @@ typedef void (*GDExtensionInterfaceStringNewWithUtf8CharsAndLen)(GDExtensionUnin
  *
  * @param r_dest A pointer to a Variant to hold the newly created String.
  * @param p_contents A pointer to a UTF-16 encoded C string.
- * @param p_size The number of characters.
+ * @param p_size The number of characters (not bytes).
  */
-typedef void (*GDExtensionInterfaceStringNewWithUtf16CharsAndLen)(GDExtensionUninitializedStringPtr r_dest, const char16_t *p_contents, GDExtensionInt p_size);
+typedef void (*GDExtensionInterfaceStringNewWithUtf16CharsAndLen)(GDExtensionUninitializedStringPtr r_dest, const char16_t *p_contents, GDExtensionInt p_char_count);
 
 /**
  * @name string_new_with_utf32_chars_and_len
@@ -1349,9 +1476,9 @@ typedef void (*GDExtensionInterfaceStringNewWithUtf16CharsAndLen)(GDExtensionUni
  *
  * @param r_dest A pointer to a Variant to hold the newly created String.
  * @param p_contents A pointer to a UTF-32 encoded C string.
- * @param p_size The number of characters.
+ * @param p_size The number of characters (not bytes).
  */
-typedef void (*GDExtensionInterfaceStringNewWithUtf32CharsAndLen)(GDExtensionUninitializedStringPtr r_dest, const char32_t *p_contents, GDExtensionInt p_size);
+typedef void (*GDExtensionInterfaceStringNewWithUtf32CharsAndLen)(GDExtensionUninitializedStringPtr r_dest, const char32_t *p_contents, GDExtensionInt p_char_count);
 
 /**
  * @name string_new_with_wide_chars_and_len
@@ -1361,9 +1488,9 @@ typedef void (*GDExtensionInterfaceStringNewWithUtf32CharsAndLen)(GDExtensionUni
  *
  * @param r_dest A pointer to a Variant to hold the newly created String.
  * @param p_contents A pointer to a wide C string.
- * @param p_size The number of characters.
+ * @param p_size The number of characters (not bytes).
  */
-typedef void (*GDExtensionInterfaceStringNewWithWideCharsAndLen)(GDExtensionUninitializedStringPtr r_dest, const wchar_t *p_contents, GDExtensionInt p_size);
+typedef void (*GDExtensionInterfaceStringNewWithWideCharsAndLen)(GDExtensionUninitializedStringPtr r_dest, const wchar_t *p_contents, GDExtensionInt p_char_count);
 
 /**
  * @name string_to_latin1_chars
@@ -1526,6 +1653,69 @@ typedef void (*GDExtensionInterfaceStringOperatorPlusEqWcstr)(GDExtensionStringP
  */
 typedef void (*GDExtensionInterfaceStringOperatorPlusEqC32str)(GDExtensionStringPtr p_self, const char32_t *p_b);
 
+/**
+ * @name string_resize
+ * @since 4.2
+ *
+ * Resizes the underlying string data to the given number of characters.
+ *
+ * Space needs to be allocated for the null terminating character ('\0') which
+ * also must be added manually, in order for all string functions to work correctly.
+ *
+ * Warning: This is an error-prone operation - only use it if there's no other
+ * efficient way to accomplish your goal.
+ *
+ * @param p_self A pointer to the String.
+ * @param p_resize The new length for the String.
+ *
+ * @return Error code signifying if the operation successful.
+ */
+typedef GDExtensionInt (*GDExtensionInterfaceStringResize)(GDExtensionStringPtr p_self, GDExtensionInt p_resize);
+
+/* INTERFACE: StringName Utilities */
+
+/**
+ * @name string_name_new_with_latin1_chars
+ * @since 4.2
+ *
+ * Creates a StringName from a Latin-1 encoded C string.
+ *
+ * If `p_is_static` is true, then:
+ * - The StringName will reuse the `p_contents` buffer instead of copying it.
+ *   You must guarantee that the buffer remains valid for the duration of the application (e.g. string literal).
+ * - You must not call a destructor for this StringName. Incrementing the initial reference once should achieve this.
+ *
+ * `p_is_static` is purely an optimization and can easily introduce undefined behavior if used wrong. In case of doubt, set it to false.
+ *
+ * @param r_dest A pointer to uninitialized storage, into which the newly created StringName is constructed.
+ * @param p_contents A pointer to a C string (null terminated and Latin-1 or ASCII encoded).
+ * @param p_is_static Whether the StringName reuses the buffer directly (see above).
+ */
+typedef void (*GDExtensionInterfaceStringNameNewWithLatin1Chars)(GDExtensionUninitializedStringNamePtr r_dest, const char *p_contents, GDExtensionBool p_is_static);
+
+/**
+ * @name string_name_new_with_utf8_chars
+ * @since 4.2
+ *
+ * Creates a StringName from a UTF-8 encoded C string.
+ *
+ * @param r_dest A pointer to uninitialized storage, into which the newly created StringName is constructed.
+ * @param p_contents A pointer to a C string (null terminated and UTF-8 encoded).
+ */
+typedef void (*GDExtensionInterfaceStringNameNewWithUtf8Chars)(GDExtensionUninitializedStringNamePtr r_dest, const char *p_contents);
+
+/**
+ * @name string_name_new_with_utf8_chars_and_len
+ * @since 4.2
+ *
+ * Creates a StringName from a UTF-8 encoded string with a given number of characters.
+ *
+ * @param r_dest A pointer to uninitialized storage, into which the newly created StringName is constructed.
+ * @param p_contents A pointer to a C string (null terminated and UTF-8 encoded).
+ * @param p_size The number of bytes (not UTF-8 code points).
+ */
+typedef void (*GDExtensionInterfaceStringNameNewWithUtf8CharsAndLen)(GDExtensionUninitializedStringNamePtr r_dest, const char *p_contents, GDExtensionInt p_size);
+
 /* INTERFACE: XMLParser Utilities */
 
 /**
@@ -2004,6 +2194,17 @@ typedef void *(*GDExtensionInterfaceObjectGetInstanceBinding)(GDExtensionObjectP
  */
 typedef void (*GDExtensionInterfaceObjectSetInstanceBinding)(GDExtensionObjectPtr p_o, void *p_token, void *p_binding, const GDExtensionInstanceBindingCallbacks *p_callbacks);
 
+/**
+ * @name object_free_instance_binding
+ * @since 4.2
+ *
+ * Free an Object's instance binding.
+ *
+ * @param p_o A pointer to the Object.
+ * @param p_library A token the library received by the GDExtension's entry point function.
+ */
+typedef void (*GDExtensionInterfaceObjectFreeInstanceBinding)(GDExtensionObjectPtr p_o, void *p_token);
+
 /**
  * @name object_set_instance
  * @since 4.1
@@ -2097,6 +2298,7 @@ typedef void (*GDExtensionInterfaceRefSetObject)(GDExtensionRefPtr p_ref, GDExte
 /**
  * @name script_instance_create
  * @since 4.1
+ * @deprecated in Godot 4.2. Use `script_instance_create2` instead.
  *
  * Creates a script instance that contains the given info and instance data.
  *
@@ -2107,6 +2309,91 @@ typedef void (*GDExtensionInterfaceRefSetObject)(GDExtensionRefPtr p_ref, GDExte
  */
 typedef GDExtensionScriptInstancePtr (*GDExtensionInterfaceScriptInstanceCreate)(const GDExtensionScriptInstanceInfo *p_info, GDExtensionScriptInstanceDataPtr p_instance_data);
 
+/**
+ * @name script_instance_create2
+ * @since 4.2
+ *
+ * Creates a script instance that contains the given info and instance data.
+ *
+ * @param p_info A pointer to a GDExtensionScriptInstanceInfo2 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 (*GDExtensionInterfaceScriptInstanceCreate2)(const GDExtensionScriptInstanceInfo2 *p_info, GDExtensionScriptInstanceDataPtr p_instance_data);
+
+/**
+ * @name placeholder_script_instance_create
+ * @since 4.2
+ *
+ * Creates a placeholder script instance for a given script and instance.
+ *
+ * This interface is optional as a custom placeholder could also be created with script_instance_create().
+ *
+ * @param p_language A pointer to a ScriptLanguage.
+ * @param p_script A pointer to a Script.
+ * @param p_owner A pointer to an Object.
+ *
+ * @return A pointer to a PlaceHolderScriptInstance object.
+ */
+typedef GDExtensionScriptInstancePtr (*GDExtensionInterfacePlaceHolderScriptInstanceCreate)(GDExtensionObjectPtr p_language, GDExtensionObjectPtr p_script, GDExtensionObjectPtr p_owner);
+
+/**
+ * @name placeholder_script_instance_update
+ * @since 4.2
+ *
+ * Updates a placeholder script instance with the given properties and values.
+ *
+ * The passed in placeholder must be an instance of PlaceHolderScriptInstance
+ * such as the one returned by placeholder_script_instance_create().
+ *
+ * @param p_placeholder A pointer to a PlaceHolderScriptInstance.
+ * @param p_properties A pointer to an Array of Dictionary representing PropertyInfo.
+ * @param p_values A pointer to a Dictionary mapping StringName to Variant values.
+ */
+typedef void (*GDExtensionInterfacePlaceHolderScriptInstanceUpdate)(GDExtensionScriptInstancePtr p_placeholder, GDExtensionConstTypePtr p_properties, GDExtensionConstTypePtr p_values);
+
+/**
+ * @name object_get_script_instance
+ * @since 4.2
+ *
+ * Get the script instance data attached to this object.
+ *
+ * @param p_object A pointer to the Object.
+ * @param p_language A pointer to the language expected for this script instance.
+ *
+ * @return A GDExtensionScriptInstanceDataPtr that was attached to this object as part of script_instance_create.
+ */
+typedef GDExtensionScriptInstanceDataPtr (*GDExtensionInterfaceObjectGetScriptInstance)(GDExtensionConstObjectPtr p_object, GDExtensionObjectPtr p_language);
+
+/* INTERFACE: Callable */
+
+/**
+ * @name callable_custom_create
+ * @since 4.2
+ *
+ * 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 (*GDExtensionInterfaceCallableCustomCreate)(GDExtensionUninitializedTypePtr r_callable, GDExtensionCallableCustomInfo *p_callable_custom_info);
+
+/**
+ * @name callable_custom_get_userdata
+ * @since 4.2
+ *
+ * Retrieves the userdata pointer from a custom Callable.
+ *
+ * If the Callable is not a custom Callable or the token does not match the one provided to callable_custom_create() via GDExtensionCallableCustomInfo then NULL will be returned.
+ *
+ * @param p_callable A pointer to a Callable.
+ * @param p_token A pointer to an address that uniquely identifies the GDExtension.
+ */
+typedef void *(*GDExtensionInterfaceCallableCustomGetUserData)(GDExtensionConstTypePtr p_callable, void *p_token);
+
 /* INTERFACE: ClassDB */
 
 /**
@@ -2154,6 +2441,7 @@ typedef void *(*GDExtensionInterfaceClassdbGetClassTag)(GDExtensionConstStringNa
 /**
  * @name classdb_register_extension_class
  * @since 4.1
+ * @deprecated in Godot 4.2. Use `classdb_register_extension_class2` instead.
  *
  * Registers an extension class in the ClassDB.
  *
@@ -2166,6 +2454,21 @@ typedef void *(*GDExtensionInterfaceClassdbGetClassTag)(GDExtensionConstStringNa
  */
 typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClass)(GDExtensionClassLibraryPtr p_library, GDExtensionConstStringNamePtr p_class_name, GDExtensionConstStringNamePtr p_parent_class_name, const GDExtensionClassCreationInfo *p_extension_funcs);
 
+/**
+ * @name classdb_register_extension_class2
+ * @since 4.2
+ *
+ * Registers an extension class in the ClassDB.
+ *
+ * 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_parent_class_name A pointer to a StringName with the parent class name.
+ * @param p_extension_funcs A pointer to a GDExtensionClassCreationInfo2 struct.
+ */
+typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClass2)(GDExtensionClassLibraryPtr p_library, GDExtensionConstStringNamePtr p_class_name, GDExtensionConstStringNamePtr p_parent_class_name, const GDExtensionClassCreationInfo2 *p_extension_funcs);
+
 /**
  * @name classdb_register_extension_class_method
  * @since 4.1
@@ -2211,6 +2514,23 @@ typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClassIntegerConstant)
  */
 typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClassProperty)(GDExtensionClassLibraryPtr p_library, GDExtensionConstStringNamePtr p_class_name, const GDExtensionPropertyInfo *p_info, GDExtensionConstStringNamePtr p_setter, GDExtensionConstStringNamePtr p_getter);
 
+/**
+ * @name classdb_register_extension_class_property_indexed
+ * @since 4.2
+ *
+ * Registers an indexed property on an extension class in the ClassDB.
+ *
+ * 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_info A pointer to a GDExtensionPropertyInfo struct.
+ * @param p_setter A pointer to a StringName with the name of the setter method.
+ * @param p_getter A pointer to a StringName with the name of the getter method.
+ * @param p_index The index to pass as the first argument to the getter and setter methods.
+ */
+typedef void (*GDExtensionInterfaceClassdbRegisterExtensionClassPropertyIndexed)(GDExtensionClassLibraryPtr p_library, GDExtensionConstStringNamePtr p_class_name, const GDExtensionPropertyInfo *p_info, GDExtensionConstStringNamePtr p_setter, GDExtensionConstStringNamePtr p_getter, GDExtensionInt p_index);
+
 /**
  * @name classdb_register_extension_class_property_group
  * @since 4.1

include/godot_cpp/classes/editor_plugin_registration.hpp

@@ -0,0 +1,62 @@
+/**************************************************************************/
+/*  editor_plugin_registration.hpp                                        */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef GODOT_EDITOR_PLUGIN_REGISTRATION_HPP
+#define GODOT_EDITOR_PLUGIN_REGISTRATION_HPP
+
+#include <godot_cpp/templates/vector.hpp>
+
+namespace godot {
+
+class EditorPlugin;
+class StringName;
+
+class EditorPlugins {
+private:
+	static Vector<StringName> plugin_classes;
+
+public:
+	static void add_plugin_class(const StringName &p_class_name);
+	static void remove_plugin_class(const StringName &p_class_name);
+	static void deinitialize(GDExtensionInitializationLevel p_level);
+
+	template <class T>
+	static void add_by_type() {
+		add_plugin_class(T::get_class_static());
+	}
+	template <class T>
+	static void remove_by_type() {
+		remove_plugin_class(T::get_class_static());
+	}
+};
+
+} // namespace godot
+
+#endif // GODOT_EDITOR_PLUGIN_REGISTRATION_HPP

include/godot_cpp/classes/ref.hpp

@@ -63,7 +63,7 @@ class Ref {
 	}
 
 	void ref_pointer(T *p_ref) {
-		ERR_FAIL_COND(!p_ref);
+		ERR_FAIL_NULL(p_ref);
 
 		if (p_ref->init_ref()) {
 			reference = p_ref;

include/godot_cpp/classes/wrapped.hpp

@@ -51,6 +51,15 @@ class Wrapped {
 	friend void postinitialize_handler(Wrapped *);
 
 protected:
+#ifdef HOT_RELOAD_ENABLED
+	struct RecreateInstance {
+		GDExtensionClassInstancePtr wrapper;
+		GDExtensionObjectPtr owner;
+		RecreateInstance *next;
+	};
+	inline static RecreateInstance *recreate_instance = nullptr;
+#endif
+
 	virtual const StringName *_get_extension_class_name() const; // This is needed to retrieve the class name before the godot object has its _extension and _extension_instance members assigned.
 	virtual const GDExtensionInstanceBindingCallbacks *_get_bindings_callbacks() const = 0;
 
@@ -60,20 +69,22 @@ protected:
 	void _get_property_list(List<PropertyInfo> *p_list) const {}
 	bool _property_can_revert(const StringName &p_name) const { return false; }
 	bool _property_get_revert(const StringName &p_name, Variant &r_property) const { return false; }
+	void _validate_property(PropertyInfo &p_property) const {}
 	String _to_string() const { return "[" + String(get_class_static()) + ":" + itos(get_instance_id()) + "]"; }
 
-	static void notification_bind(GDExtensionClassInstancePtr p_instance, int32_t p_what) {}
+	static void notification_bind(GDExtensionClassInstancePtr p_instance, int32_t p_what, GDExtensionBool p_reversed) {}
 	static GDExtensionBool set_bind(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionConstVariantPtr p_value) { return false; }
 	static GDExtensionBool get_bind(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionVariantPtr r_ret) { return false; }
 	static const GDExtensionPropertyInfo *get_property_list_bind(GDExtensionClassInstancePtr p_instance, uint32_t *r_count) { return nullptr; }
 	static void free_property_list_bind(GDExtensionClassInstancePtr p_instance, const GDExtensionPropertyInfo *p_list) {}
 	static GDExtensionBool property_can_revert_bind(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name) { return false; }
 	static GDExtensionBool property_get_revert_bind(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionVariantPtr r_ret) { return false; }
+	static GDExtensionBool validate_property_bind(GDExtensionClassInstancePtr p_instance, GDExtensionPropertyInfo *p_property) { return false; }
 	static void to_string_bind(GDExtensionClassInstancePtr p_instance, GDExtensionBool *r_is_valid, GDExtensionStringPtr r_out) {}
 
+	// The only reason this has to be held here, is when we return results of `_get_property_list` to Godot, we pass
+	// pointers to strings in this list. They have to remain valid to pass the bridge, until the list is freed by Godot...
 	::godot::List<::godot::PropertyInfo> plist_owned;
-	GDExtensionPropertyInfo *plist = nullptr;
-	uint32_t plist_size = 0;
 
 	void _postinitialize();
 
@@ -95,9 +106,46 @@ public:
 	GodotObject *_owner = nullptr;
 };
 
+namespace internal {
+
+GDExtensionPropertyInfo *create_c_property_list(const ::godot::List<::godot::PropertyInfo> &plist_cpp, uint32_t *r_size);
+void free_c_property_list(GDExtensionPropertyInfo *plist);
+
+typedef void (*EngineClassRegistrationCallback)();
+void add_engine_class_registration_callback(EngineClassRegistrationCallback p_callback);
+void register_engine_class(const StringName &p_name, const GDExtensionInstanceBindingCallbacks *p_callbacks);
+void register_engine_classes();
+
+template <class T>
+struct EngineClassRegistration {
+	EngineClassRegistration() {
+		add_engine_class_registration_callback(&EngineClassRegistration<T>::callback);
+	}
+
+	static void callback() {
+		register_engine_class(T::get_class_static(), &T::_gde_binding_callbacks);
+	}
+};
+
+} // namespace internal
+
 } // namespace godot
 
-#define GDCLASS(m_class, m_inherits)                                                                                                                                                   \
+#ifdef HOT_RELOAD_ENABLED
+#define _GDCLASS_RECREATE(m_class, m_inherits)                                                   \
+	m_class *new_instance = (m_class *)memalloc(sizeof(m_class));                                \
+	Wrapped::RecreateInstance recreate_data = { new_instance, obj, Wrapped::recreate_instance }; \
+	Wrapped::recreate_instance = &recreate_data;                                                 \
+	memnew_placement(new_instance, m_class);                                                     \
+	return new_instance;
+#else
+#define _GDCLASS_RECREATE(m_class, m_inherits) return nullptr;
+#endif
+
+// Use this on top of your own classes.
+// Note: the trail of `***` is to keep sane diffs in PRs, because clang-format otherwise moves every `\` which makes
+// every line of the macro different
+#define GDCLASS(m_class, m_inherits) /***********************************************************************************************************************************************/ \
 private:                                                                                                                                                                               \
 	void operator=(const m_class &p_rval) {}                                                                                                                                           \
 	friend class ::godot::ClassDB;                                                                                                                                                     \
@@ -132,16 +180,20 @@ protected:
 		return (void(::godot::Wrapped::*)(::godot::List<::godot::PropertyInfo> * p_list) const) & m_class::_get_property_list;                                                         \
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
-	static bool (::godot::Wrapped::*_get_property_can_revert())(const ::godot::StringName &p_name) {                                                                                   \
-		return (bool(::godot::Wrapped::*)(const ::godot::StringName &p_name)) & m_class::_property_can_revert;                                                                         \
+	static bool (::godot::Wrapped::*_get_property_can_revert())(const ::godot::StringName &p_name) const {                                                                             \
+		return (bool(::godot::Wrapped::*)(const ::godot::StringName &p_name) const) & m_class::_property_can_revert;                                                                   \
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
-	static bool (::godot::Wrapped::*_get_property_get_revert())(const ::godot::StringName &p_name, ::godot::Variant &) {                                                               \
-		return (bool(::godot::Wrapped::*)(const ::godot::StringName &p_name, ::godot::Variant &)) & m_class::_property_get_revert;                                                     \
+	static bool (::godot::Wrapped::*_get_property_get_revert())(const ::godot::StringName &p_name, ::godot::Variant &) const {                                                         \
+		return (bool(::godot::Wrapped::*)(const ::godot::StringName &p_name, ::godot::Variant &) const) & m_class::_property_get_revert;                                               \
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
-	static ::godot::String (::godot::Wrapped::*_get_to_string())() {                                                                                                                   \
-		return (::godot::String(::godot::Wrapped::*)()) & m_class::_to_string;                                                                                                         \
+	static void (::godot::Wrapped::*_get_validate_property())(::godot::PropertyInfo & p_property) const {                                                                              \
+		return (void(::godot::Wrapped::*)(::godot::PropertyInfo & p_property) const) & m_class::_validate_property;                                                                    \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static ::godot::String (::godot::Wrapped::*_get_to_string())() const {                                                                                                             \
+		return (::godot::String(::godot::Wrapped::*)() const) & m_class::_to_string;                                                                                                   \
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
 	template <class T, class B>                                                                                                                                                        \
@@ -150,6 +202,8 @@ protected:
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
 public:                                                                                                                                                                                \
+	typedef m_class self_type;                                                                                                                                                         \
+                                                                                                                                                                                       \
 	static void initialize_class() {                                                                                                                                                   \
 		static bool initialized = false;                                                                                                                                               \
 		if (initialized) {                                                                                                                                                             \
@@ -177,13 +231,17 @@ public:
 		return new_object->_owner;                                                                                                                                                     \
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
-	static void notification_bind(GDExtensionClassInstancePtr p_instance, int32_t p_what) {                                                                                            \
+	static GDExtensionClassInstancePtr recreate(void *data, GDExtensionObjectPtr obj) {                                                                                                \
+		_GDCLASS_RECREATE(m_class, m_inherits);                                                                                                                                        \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static void notification_bind(GDExtensionClassInstancePtr p_instance, int32_t p_what, GDExtensionBool p_reversed) {                                                                \
 		if (p_instance && m_class::_get_notification()) {                                                                                                                              \
 			if (m_class::_get_notification() != m_inherits::_get_notification()) {                                                                                                     \
 				m_class *cls = reinterpret_cast<m_class *>(p_instance);                                                                                                                \
 				return cls->_notification(p_what);                                                                                                                                     \
 			}                                                                                                                                                                          \
-			m_inherits::notification_bind(p_instance, p_what);                                                                                                                         \
+			m_inherits::notification_bind(p_instance, p_what, p_reversed);                                                                                                             \
 		}                                                                                                                                                                              \
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
@@ -209,40 +267,29 @@ public:
 		return false;                                                                                                                                                                  \
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
+	static inline bool has_get_property_list() {                                                                                                                                       \
+		return m_class::_get_get_property_list() && m_class::_get_get_property_list() != m_inherits::_get_get_property_list();                                                         \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
 	static const GDExtensionPropertyInfo *get_property_list_bind(GDExtensionClassInstancePtr p_instance, uint32_t *r_count) {                                                          \
-		if (p_instance && m_class::_get_get_property_list()) {                                                                                                                         \
-			if (m_class::_get_get_property_list() != m_inherits::_get_get_property_list()) {                                                                                           \
-				m_class *cls = reinterpret_cast<m_class *>(p_instance);                                                                                                                \
-				ERR_FAIL_COND_V_MSG(!cls->plist_owned.is_empty() || cls->plist != nullptr || cls->plist_size != 0, nullptr, "Internal error, property list was not freed by engine!"); \
-				cls->_get_property_list(&cls->plist_owned);                                                                                                                            \
-				cls->plist = reinterpret_cast<GDExtensionPropertyInfo *>(memalloc(sizeof(GDExtensionPropertyInfo) * cls->plist_owned.size()));                                         \
-				cls->plist_size = 0;                                                                                                                                                   \
-				for (const ::godot::PropertyInfo &E : cls->plist_owned) {                                                                                                              \
-					cls->plist[cls->plist_size].type = static_cast<GDExtensionVariantType>(E.type);                                                                                    \
-					cls->plist[cls->plist_size].name = E.name._native_ptr();                                                                                                           \
-					cls->plist[cls->plist_size].hint = E.hint;                                                                                                                         \
-					cls->plist[cls->plist_size].hint_string = E.hint_string._native_ptr();                                                                                             \
-					cls->plist[cls->plist_size].class_name = E.class_name._native_ptr();                                                                                               \
-					cls->plist[cls->plist_size].usage = E.usage;                                                                                                                       \
-					cls->plist_size++;                                                                                                                                                 \
-				}                                                                                                                                                                      \
-				if (r_count)                                                                                                                                                           \
-					*r_count = cls->plist_size;                                                                                                                                        \
-				return cls->plist;                                                                                                                                                     \
-			}                                                                                                                                                                          \
-			return m_inherits::get_property_list_bind(p_instance, r_count);                                                                                                            \
+		if (!p_instance) {                                                                                                                                                             \
+			if (r_count)                                                                                                                                                               \
+				*r_count = 0;                                                                                                                                                          \
+			return nullptr;                                                                                                                                                            \
 		}                                                                                                                                                                              \
-		return nullptr;                                                                                                                                                                \
+		m_class *cls = reinterpret_cast<m_class *>(p_instance);                                                                                                                        \
+		::godot::List<::godot::PropertyInfo> &plist_cpp = cls->plist_owned;                                                                                                            \
+		ERR_FAIL_COND_V_MSG(!plist_cpp.is_empty(), nullptr, "Internal error, property list was not freed by engine!");                                                                 \
+		cls->_get_property_list(&plist_cpp);                                                                                                                                           \
+		return ::godot::internal::create_c_property_list(plist_cpp, r_count);                                                                                                          \
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
 	static void free_property_list_bind(GDExtensionClassInstancePtr p_instance, const GDExtensionPropertyInfo *p_list) {                                                               \
 		if (p_instance) {                                                                                                                                                              \
 			m_class *cls = reinterpret_cast<m_class *>(p_instance);                                                                                                                    \
-			ERR_FAIL_COND_MSG(cls->plist == nullptr, "Internal error, property list double free!");                                                                                    \
-			memfree(cls->plist);                                                                                                                                                       \
-			cls->plist = nullptr;                                                                                                                                                      \
-			cls->plist_size = 0;                                                                                                                                                       \
 			cls->plist_owned.clear();                                                                                                                                                  \
+			/* TODO `GDExtensionClassFreePropertyList` is ill-defined, we need a non-const pointer to free this. */                                                                    \
+			::godot::internal::free_c_property_list(const_cast<GDExtensionPropertyInfo *>(p_list));                                                                                    \
 		}                                                                                                                                                                              \
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
@@ -268,6 +315,21 @@ public:
 		return false;                                                                                                                                                                  \
 	}                                                                                                                                                                                  \
                                                                                                                                                                                        \
+	static GDExtensionBool validate_property_bind(GDExtensionClassInstancePtr p_instance, GDExtensionPropertyInfo *p_property) {                                                       \
+		bool ret = false;                                                                                                                                                              \
+		if (p_instance && m_class::_get_validate_property()) {                                                                                                                         \
+			ret = m_inherits::validate_property_bind(p_instance, p_property);                                                                                                          \
+			if (m_class::_get_validate_property() != m_inherits::_get_validate_property()) {                                                                                           \
+				m_class *cls = reinterpret_cast<m_class *>(p_instance);                                                                                                                \
+				::godot::PropertyInfo info(p_property);                                                                                                                                \
+				cls->_validate_property(info);                                                                                                                                         \
+				info._update(p_property);                                                                                                                                              \
+				return true;                                                                                                                                                           \
+			}                                                                                                                                                                          \
+		}                                                                                                                                                                              \
+		return ret;                                                                                                                                                                    \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
 	static void to_string_bind(GDExtensionClassInstancePtr p_instance, GDExtensionBool *r_is_valid, GDExtensionStringPtr r_out) {                                                      \
 		if (p_instance && m_class::_get_to_string()) {                                                                                                                                 \
 			if (m_class::_get_to_string() != m_inherits::_get_to_string()) {                                                                                                           \
@@ -303,82 +365,111 @@ public:
 		_gde_binding_create_callback,                                                                                                                                                  \
 		_gde_binding_free_callback,                                                                                                                                                    \
 		_gde_binding_reference_callback,                                                                                                                                               \
-	};
+	};                                                                                                                                                                                 \
+                                                                                                                                                                                       \
+private:
 
 // Don't use this for your classes, use GDCLASS() instead.
-#define GDEXTENSION_CLASS(m_class, m_inherits)                                                                             \
-private:                                                                                                                   \
-	void operator=(const m_class &p_rval) {}                                                                               \
-                                                                                                                           \
-protected:                                                                                                                 \
-	virtual const GDExtensionInstanceBindingCallbacks *_get_bindings_callbacks() const override {                          \
-		return &_gde_binding_callbacks;                                                                                    \
-	}                                                                                                                      \
-                                                                                                                           \
-	m_class(const char *p_godot_class) : m_inherits(p_godot_class) {}                                                      \
-	m_class(GodotObject *p_godot_object) : m_inherits(p_godot_object) {}                                                   \
-                                                                                                                           \
-	static void (*_get_bind_methods())() {                                                                                 \
-		return nullptr;                                                                                                    \
-	}                                                                                                                      \
-                                                                                                                           \
-	static void (Wrapped::*_get_notification())(int) {                                                                     \
-		return nullptr;                                                                                                    \
-	}                                                                                                                      \
-                                                                                                                           \
-	static bool (Wrapped::*_get_set())(const ::godot::StringName &p_name, const Variant &p_property) {                     \
-		return nullptr;                                                                                                    \
-	}                                                                                                                      \
-                                                                                                                           \
-	static bool (Wrapped::*_get_get())(const ::godot::StringName &p_name, Variant &r_ret) const {                          \
-		return nullptr;                                                                                                    \
-	}                                                                                                                      \
-                                                                                                                           \
-	static void (Wrapped::*_get_get_property_list())(List<PropertyInfo> * p_list) const {                                  \
-		return nullptr;                                                                                                    \
-	}                                                                                                                      \
-                                                                                                                           \
-	static bool (Wrapped::*_get_property_can_revert())(const ::godot::StringName &p_name) {                                \
-		return nullptr;                                                                                                    \
-	}                                                                                                                      \
-                                                                                                                           \
-	static bool (Wrapped::*_get_property_get_revert())(const ::godot::StringName &p_name, Variant &) {                     \
-		return nullptr;                                                                                                    \
-	}                                                                                                                      \
-                                                                                                                           \
-	static String (Wrapped::*_get_to_string())() {                                                                         \
-		return nullptr;                                                                                                    \
-	}                                                                                                                      \
-                                                                                                                           \
-public:                                                                                                                    \
-	static void initialize_class() {}                                                                                      \
-                                                                                                                           \
-	static ::godot::StringName &get_class_static() {                                                                       \
-		static ::godot::StringName string_name = ::godot::StringName(#m_class);                                            \
-		return string_name;                                                                                                \
-	}                                                                                                                      \
-                                                                                                                           \
-	static ::godot::StringName &get_parent_class_static() {                                                                \
-		return m_inherits::get_class_static();                                                                             \
-	}                                                                                                                      \
-                                                                                                                           \
-	static void *_gde_binding_create_callback(void *p_token, void *p_instance) {                                           \
-		/* Do not call memnew here, we don't want the post-initializer to be called */                                     \
-		return new ("") m_class((GodotObject *)p_instance);                                                                \
-	}                                                                                                                      \
-	static void _gde_binding_free_callback(void *p_token, void *p_instance, void *p_binding) {                             \
-		/* Explicitly call the deconstructor to ensure proper lifecycle for non-trivial members */                         \
-		reinterpret_cast<m_class *>(p_binding)->~m_class();                                                                \
-		Memory::free_static(reinterpret_cast<m_class *>(p_binding));                                                       \
-	}                                                                                                                      \
-	static GDExtensionBool _gde_binding_reference_callback(void *p_token, void *p_instance, GDExtensionBool p_reference) { \
-		return true;                                                                                                       \
-	}                                                                                                                      \
-	static constexpr GDExtensionInstanceBindingCallbacks _gde_binding_callbacks = {                                        \
-		_gde_binding_create_callback,                                                                                      \
-		_gde_binding_free_callback,                                                                                        \
-		_gde_binding_reference_callback,                                                                                   \
-	};                                                                                                                     \
-	m_class() : m_class(#m_class) {}
+#define GDEXTENSION_CLASS_ALIAS(m_class, m_alias_for, m_inherits) /******************************************************************************************************************/ \
+private:                                                                                                                                                                               \
+	inline static ::godot::internal::EngineClassRegistration<m_class> _gde_engine_class_registration_helper;                                                                           \
+	void operator=(const m_class &p_rval) {}                                                                                                                                           \
+                                                                                                                                                                                       \
+protected:                                                                                                                                                                             \
+	virtual const GDExtensionInstanceBindingCallbacks *_get_bindings_callbacks() const override {                                                                                      \
+		return &_gde_binding_callbacks;                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	m_class(const char *p_godot_class) : m_inherits(p_godot_class) {}                                                                                                                  \
+	m_class(GodotObject *p_godot_object) : m_inherits(p_godot_object) {}                                                                                                               \
+                                                                                                                                                                                       \
+	static void (*_get_bind_methods())() {                                                                                                                                             \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static void (Wrapped::*_get_notification())(int) {                                                                                                                                 \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static bool (Wrapped::*_get_set())(const ::godot::StringName &p_name, const Variant &p_property) {                                                                                 \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static bool (Wrapped::*_get_get())(const ::godot::StringName &p_name, Variant &r_ret) const {                                                                                      \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static inline bool has_get_property_list() {                                                                                                                                       \
+		return false;                                                                                                                                                                  \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static void (Wrapped::*_get_get_property_list())(List<PropertyInfo> * p_list) const {                                                                                              \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static bool (Wrapped::*_get_property_can_revert())(const ::godot::StringName &p_name) const {                                                                                      \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static bool (Wrapped::*_get_property_get_revert())(const ::godot::StringName &p_name, Variant &) const {                                                                           \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static void (Wrapped::*_get_validate_property())(::godot::PropertyInfo & p_property) const {                                                                                       \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static String (Wrapped::*_get_to_string())() const {                                                                                                                               \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+public:                                                                                                                                                                                \
+	typedef m_class self_type;                                                                                                                                                         \
+                                                                                                                                                                                       \
+	static void initialize_class() {}                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static ::godot::StringName &get_class_static() {                                                                                                                                   \
+		static ::godot::StringName string_name = ::godot::StringName(#m_alias_for);                                                                                                    \
+		return string_name;                                                                                                                                                            \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static ::godot::StringName &get_parent_class_static() {                                                                                                                            \
+		return m_inherits::get_class_static();                                                                                                                                         \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static GDExtensionObjectPtr create(void *data) {                                                                                                                                   \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static GDExtensionClassInstancePtr recreate(void *data, GDExtensionObjectPtr obj) {                                                                                                \
+		return nullptr;                                                                                                                                                                \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static void free(void *data, GDExtensionClassInstancePtr ptr) {                                                                                                                    \
+	}                                                                                                                                                                                  \
+                                                                                                                                                                                       \
+	static void *_gde_binding_create_callback(void *p_token, void *p_instance) {                                                                                                       \
+		/* Do not call memnew here, we don't want the post-initializer to be called */                                                                                                 \
+		return new ("", "") m_class((GodotObject *)p_instance);                                                                                                                        \
+	}                                                                                                                                                                                  \
+	static void _gde_binding_free_callback(void *p_token, void *p_instance, void *p_binding) {                                                                                         \
+		/* Explicitly call the deconstructor to ensure proper lifecycle for non-trivial members */                                                                                     \
+		reinterpret_cast<m_class *>(p_binding)->~m_class();                                                                                                                            \
+		Memory::free_static(reinterpret_cast<m_class *>(p_binding));                                                                                                                   \
+	}                                                                                                                                                                                  \
+	static GDExtensionBool _gde_binding_reference_callback(void *p_token, void *p_instance, GDExtensionBool p_reference) {                                                             \
+		return true;                                                                                                                                                                   \
+	}                                                                                                                                                                                  \
+	static constexpr GDExtensionInstanceBindingCallbacks _gde_binding_callbacks = {                                                                                                    \
+		_gde_binding_create_callback,                                                                                                                                                  \
+		_gde_binding_free_callback,                                                                                                                                                    \
+		_gde_binding_reference_callback,                                                                                                                                               \
+	};                                                                                                                                                                                 \
+	m_class() : m_class(#m_alias_for) {}                                                                                                                                               \
+                                                                                                                                                                                       \
+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)
 
 #endif // GODOT_WRAPPED_HPP

include/godot_cpp/core/binder_common.hpp

@@ -276,6 +276,60 @@ void call_with_variant_args_retc_helper(T *p_instance, R (T::*p_method)(P...) co
 	(void)p_args;
 }
 
+template <class T, class... P>
+void call_with_variant_args(T *p_instance, void (T::*p_method)(P...), const Variant **p_args, int p_argcount, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_helper<T, P...>(p_instance, p_method, p_args, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class T, class R, class... P>
+void call_with_variant_args_ret(T *p_instance, R (T::*p_method)(P...), const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_ret_helper<T, R, P...>(p_instance, p_method, p_args, r_ret, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class T, class R, class... P>
+void call_with_variant_args_retc(T *p_instance, R (T::*p_method)(P...) const, const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_retc_helper<T, R, P...>(p_instance, p_method, p_args, r_ret, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
 template <class T, class... P>
 void call_with_variant_args_dv(T *p_instance, void (T::*p_method)(P...), const GDExtensionConstVariantPtr *p_args, int p_argcount, GDExtensionCallError &r_error, const std::vector<Variant> &default_values) {
 #ifdef DEBUG_ENABLED
@@ -538,6 +592,42 @@ void call_with_ptr_args_static_method(void (*p_method)(P...), const GDExtensionC
 	call_with_ptr_args_static_method_helper<P...>(p_method, p_args, BuildIndexSequence<sizeof...(P)>{});
 }
 
+template <class R, class... P>
+void call_with_variant_args_static_ret(R (*p_method)(P...), const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_static_ret<R, P...>(p_method, p_args, r_ret, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
+template <class... P>
+void call_with_variant_args_static_ret(void (*p_method)(P...), const Variant **p_args, int p_argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+#ifdef DEBUG_ENABLED
+	if ((size_t)p_argcount > sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_MANY_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+
+	if ((size_t)p_argcount < sizeof...(P)) {
+		r_error.error = GDEXTENSION_CALL_ERROR_TOO_FEW_ARGUMENTS;
+		r_error.argument = (int32_t)sizeof...(P);
+		return;
+	}
+#endif
+	call_with_variant_args_static<P...>(p_method, p_args, r_error, BuildIndexSequence<sizeof...(P)>{});
+}
+
 template <class R, class... P, size_t... Is>
 void call_with_variant_args_static_ret(R (*p_method)(P...), const Variant **p_args, Variant &r_ret, GDExtensionCallError &r_error, IndexSequence<Is...>) {
 	r_error.error = GDEXTENSION_CALL_OK;

include/godot_cpp/core/class_db.hpp

@@ -38,6 +38,12 @@
 #include <godot_cpp/core/method_bind.hpp>
 #include <godot_cpp/core/object.hpp>
 
+#include <godot_cpp/classes/class_db_singleton.hpp>
+
+// Makes callable_mp readily available in all classes connecting signals.
+// Needs to come after method_bind and object have been included.
+#include <godot_cpp/variant/callable_method_pointer.hpp>
+
 #include <list>
 #include <set>
 #include <string>
@@ -79,15 +85,6 @@ class ClassDB {
 	friend class godot::GDExtensionBinding;
 
 public:
-	struct PropertySetGet {
-		int index;
-		StringName setter;
-		StringName getter;
-		MethodBind *_setptr;
-		MethodBind *_getptr;
-		Variant::Type type;
-	};
-
 	struct ClassInfo {
 		StringName name;
 		StringName parent_name;
@@ -113,7 +110,7 @@ private:
 	static void bind_method_godot(const StringName &p_class_name, MethodBind *p_method);
 
 	template <class T, bool is_abstract>
-	static void _register_class(bool p_virtual = false);
+	static void _register_class(bool p_virtual = false, bool p_exposed = true);
 
 public:
 	template <class T>
@@ -121,7 +118,11 @@ public:
 	template <class T>
 	static void register_abstract_class();
 	template <class T>
-	static void register_engine_class();
+	static void register_internal_class();
+
+	_FORCE_INLINE_ static void _register_engine_class(const StringName &p_name, const GDExtensionInstanceBindingCallbacks *p_callbacks) {
+		instance_binding_callbacks[p_name] = p_callbacks;
+	}
 
 	template <class N, class M, typename... VarArgs>
 	static MethodBind *bind_method(N p_method_name, M p_method, VarArgs... p_args);
@@ -146,6 +147,8 @@ public:
 
 	static void initialize(GDExtensionInitializationLevel p_level);
 	static void deinitialize(GDExtensionInitializationLevel p_level);
+
+	CLASSDB_SINGLETON_FORWARD_METHODS;
 };
 
 #define BIND_CONSTANT(m_constant) \
@@ -166,7 +169,8 @@ public:
 	}
 
 template <class T, bool is_abstract>
-void ClassDB::_register_class(bool p_virtual) {
+void ClassDB::_register_class(bool p_virtual, bool p_exposed) {
+	static_assert(TypesAreSame<typename T::self_type, T>::value, "Class not declared properly, please use GDCLASS.");
 	instance_binding_callbacks[T::get_class_static()] = &T::_gde_binding_callbacks;
 
 	// Register this class within our plugin
@@ -183,27 +187,32 @@ void ClassDB::_register_class(bool p_virtual) {
 	class_register_order.push_back(cl.name);
 
 	// Register this class with Godot
-	GDExtensionClassCreationInfo class_info = {
+	GDExtensionClassCreationInfo2 class_info = {
 		p_virtual, // GDExtensionBool is_virtual;
 		is_abstract, // GDExtensionBool is_abstract;
+		p_exposed, // GDExtensionBool is_exposed;
 		T::set_bind, // GDExtensionClassSet set_func;
 		T::get_bind, // GDExtensionClassGet get_func;
-		T::get_property_list_bind, // GDExtensionClassGetPropertyList get_property_list_func;
+		T::has_get_property_list() ? T::get_property_list_bind : nullptr, // GDExtensionClassGetPropertyList get_property_list_func;
 		T::free_property_list_bind, // GDExtensionClassFreePropertyList free_property_list_func;
 		T::property_can_revert_bind, // GDExtensionClassPropertyCanRevert property_can_revert_func;
 		T::property_get_revert_bind, // GDExtensionClassPropertyGetRevert property_get_revert_func;
-		T::notification_bind, // GDExtensionClassNotification notification_func;
+		T::validate_property_bind, // GDExtensionClassValidateProperty validate_property_func;
+		T::notification_bind, // GDExtensionClassNotification2 notification_func;
 		T::to_string_bind, // GDExtensionClassToString to_string_func;
 		nullptr, // GDExtensionClassReference reference_func;
 		nullptr, // GDExtensionClassUnreference unreference_func;
 		T::create, // GDExtensionClassCreateInstance create_instance_func; /* this one is mandatory */
 		T::free, // GDExtensionClassFreeInstance free_instance_func; /* this one is mandatory */
+		T::recreate, // GDExtensionClassRecreateInstance recreate_instance_func;
 		&ClassDB::get_virtual_func, // GDExtensionClassGetVirtual get_virtual_func;
+		nullptr, // GDExtensionClassGetVirtualCallData get_virtual_call_data_func;
+		nullptr, // GDExtensionClassCallVirtualWithData call_virtual_func;
 		nullptr, // GDExtensionClassGetRID get_rid;
 		(void *)&T::get_class_static(), // void *class_userdata;
 	};
 
-	internal::gdextension_interface_classdb_register_extension_class(internal::library, cl.name._native_ptr(), cl.parent_name._native_ptr(), &class_info);
+	internal::gdextension_interface_classdb_register_extension_class2(internal::library, cl.name._native_ptr(), cl.parent_name._native_ptr(), &class_info);
 
 	// call bind_methods etc. to register all members of the class
 	T::initialize_class();
@@ -223,8 +232,8 @@ void ClassDB::register_abstract_class() {
 }
 
 template <class T>
-void ClassDB::register_engine_class() {
-	instance_binding_callbacks[T::get_class_static()] = &T::_gde_binding_callbacks;
+void ClassDB::register_internal_class() {
+	ClassDB::_register_class<T, false>(false, false);
 }
 
 template <class N, class M, typename... VarArgs>
@@ -253,7 +262,7 @@ MethodBind *ClassDB::bind_static_method(StringName p_class, N p_method_name, M p
 template <class M>
 MethodBind *ClassDB::bind_vararg_method(uint32_t p_flags, StringName p_name, M p_method, const MethodInfo &p_info, const std::vector<Variant> &p_default_args, bool p_return_nil_is_variant) {
 	MethodBind *bind = create_vararg_method_bind(p_method, p_info, p_return_nil_is_variant);
-	ERR_FAIL_COND_V(!bind, nullptr);
+	ERR_FAIL_NULL_V(bind, nullptr);
 
 	bind->set_name(p_name);
 	bind->set_default_arguments(p_default_args);
@@ -285,6 +294,7 @@ MethodBind *ClassDB::bind_vararg_method(uint32_t p_flags, StringName p_name, M p
 #define GDREGISTER_CLASS(m_class) ClassDB::register_class<m_class>();
 #define GDREGISTER_VIRTUAL_CLASS(m_class) ClassDB::register_class<m_class>(true);
 #define GDREGISTER_ABSTRACT_CLASS(m_class) ClassDB::register_abstract_class<m_class>();
+#define GDREGISTER_INTERNAL_CLASS(m_class) ClassDB::register_internal_class<m_class>();
 
 } // namespace godot
 

include/godot_cpp/core/memory.hpp

@@ -44,20 +44,21 @@
 #define PAD_ALIGN 16 //must always be greater than this at much
 #endif
 
-void *operator new(size_t p_size, const char *p_description); ///< operator new that takes a description and uses MemoryStaticPool
-void *operator new(size_t p_size, void *(*p_allocfunc)(size_t p_size)); ///< operator new that takes a description and uses MemoryStaticPool
-void *operator new(size_t p_size, void *p_pointer, size_t check, const char *p_description); ///< operator new that takes a description and uses a pointer to the preallocated memory
+// p_dummy argument is added to avoid conflicts with the engine functions when both engine and GDExtension are built as a static library on iOS.
+void *operator new(size_t p_size, const char *p_dummy, const char *p_description); ///< operator new that takes a description and uses MemoryStaticPool
+void *operator new(size_t p_size, const char *p_dummy, void *(*p_allocfunc)(size_t p_size)); ///< operator new that takes a description and uses MemoryStaticPool
+void *operator new(size_t p_size, const char *p_dummy, void *p_pointer, size_t check, const char *p_description); ///< operator new that takes a description and uses a pointer to the preallocated memory
 
-_ALWAYS_INLINE_ void *operator new(size_t p_size, void *p_pointer, size_t check, const char *p_description) {
+_ALWAYS_INLINE_ void *operator new(size_t p_size, const char *p_dummy, void *p_pointer, size_t check, const char *p_description) {
 	return p_pointer;
 }
 
 #ifdef _MSC_VER
 // When compiling with VC++ 2017, the above declarations of placement new generate many irrelevant warnings (C4291).
 // The purpose of the following definitions is to muffle these warnings, not to provide a usable implementation of placement delete.
-void operator delete(void *p_mem, const char *p_description);
-void operator delete(void *p_mem, void *(*p_allocfunc)(size_t p_size));
-void operator delete(void *p_mem, void *p_pointer, size_t check, const char *p_description);
+void operator delete(void *p_mem, const char *p_dummy, const char *p_description);
+void operator delete(void *p_mem, const char *p_dummy, void *(*p_allocfunc)(size_t p_size));
+void operator delete(void *p_mem, const char *p_dummy, void *p_pointer, size_t check, const char *p_description);
 #endif
 
 namespace godot {
@@ -85,10 +86,10 @@ _ALWAYS_INLINE_ T *_post_initialize(T *p_obj) {
 #define memrealloc(m_mem, m_size) ::godot::Memory::realloc_static(m_mem, m_size)
 #define memfree(m_mem) ::godot::Memory::free_static(m_mem)
 
-#define memnew(m_class) ::godot::_post_initialize(new ("") m_class)
+#define memnew(m_class) ::godot::_post_initialize(new ("", "") m_class)
 
-#define memnew_allocator(m_class, m_allocator) ::godot::_post_initialize(new (m_allocator::alloc) m_class)
-#define memnew_placement(m_placement, m_class) ::godot::_post_initialize(new (m_placement, sizeof(m_class), "") m_class)
+#define memnew_allocator(m_class, m_allocator) ::godot::_post_initialize(new ("", m_allocator::alloc) m_class)
+#define memnew_placement(m_placement, m_class) ::godot::_post_initialize(new ("", m_placement, sizeof(m_class), "") m_class)
 
 // Generic comparator used in Map, List, etc.
 template <class T>
@@ -146,7 +147,7 @@ T *memnew_arr_template(size_t p_elements, const char *p_descr = "") {
 	size_t len = sizeof(T) * p_elements;
 	uint64_t *mem = (uint64_t *)Memory::alloc_static(len, true);
 	T *failptr = nullptr; // Get rid of a warning.
-	ERR_FAIL_COND_V(!mem, failptr);
+	ERR_FAIL_NULL_V(mem, failptr);
 	*(mem - 1) = p_elements;
 
 	if (!std::is_trivially_destructible<T>::value) {
@@ -154,7 +155,7 @@ T *memnew_arr_template(size_t p_elements, const char *p_descr = "") {
 
 		/* call operator new */
 		for (size_t i = 0; i < p_elements; i++) {
-			new (&elems[i], sizeof(T), p_descr) T;
+			new ("", &elems[i], sizeof(T), p_descr) T;
 		}
 	}
 

include/godot_cpp/core/method_ptrcall.hpp

@@ -168,6 +168,7 @@ MAKE_PTRARG_BY_REFERENCE(Variant);
 
 template <class T>
 struct PtrToArg<T *> {
+	static_assert(std::is_base_of<Object, T>::value, "Cannot encode non-Object value as an Object");
 	_FORCE_INLINE_ static T *convert(const void *p_ptr) {
 		return reinterpret_cast<T *>(godot::internal::get_object_instance_binding(*reinterpret_cast<GDExtensionObjectPtr *>(const_cast<void *>(p_ptr))));
 	}
@@ -179,6 +180,7 @@ struct PtrToArg<T *> {
 
 template <class T>
 struct PtrToArg<const T *> {
+	static_assert(std::is_base_of<Object, T>::value, "Cannot encode non-Object value as an Object");
 	_FORCE_INLINE_ static const T *convert(const void *p_ptr) {
 		return reinterpret_cast<const T *>(godot::internal::get_object_instance_binding(*reinterpret_cast<GDExtensionObjectPtr *>(const_cast<void *>(p_ptr))));
 	}

include/godot_cpp/core/object.hpp

@@ -33,6 +33,8 @@
 
 #include <godot_cpp/core/defs.hpp>
 
+#include <godot_cpp/core/object_id.hpp>
+
 #include <godot_cpp/core/property_info.hpp>
 
 #include <godot_cpp/variant/variant.hpp>
@@ -49,6 +51,7 @@
 #define ADD_GROUP(m_name, m_prefix) godot::ClassDB::add_property_group(get_class_static(), m_name, m_prefix)
 #define ADD_SUBGROUP(m_name, m_prefix) godot::ClassDB::add_property_subgroup(get_class_static(), m_name, m_prefix)
 #define ADD_PROPERTY(m_property, m_setter, m_getter) godot::ClassDB::add_property(get_class_static(), m_property, m_setter, m_getter)
+#define ADD_PROPERTYI(m_property, m_setter, m_getter, m_index) godot::ClassDB::add_property(get_class_static(), m_property, m_setter, m_getter, m_index)
 
 namespace godot {
 
@@ -105,28 +108,6 @@ MethodInfo::MethodInfo(const PropertyInfo &p_ret, StringName p_name, const Args
 	arguments = { args... };
 }
 
-class ObjectID {
-	uint64_t id = 0;
-
-public:
-	_FORCE_INLINE_ bool is_ref_counted() const { return (id & (uint64_t(1) << 63)) != 0; }
-	_FORCE_INLINE_ bool is_valid() const { return id != 0; }
-	_FORCE_INLINE_ bool is_null() const { return id == 0; }
-	_FORCE_INLINE_ operator uint64_t() const { return id; }
-	_FORCE_INLINE_ operator int64_t() const { return id; }
-
-	_FORCE_INLINE_ bool operator==(const ObjectID &p_id) const { return id == p_id.id; }
-	_FORCE_INLINE_ bool operator!=(const ObjectID &p_id) const { return id != p_id.id; }
-	_FORCE_INLINE_ bool operator<(const ObjectID &p_id) const { return id < p_id.id; }
-
-	_FORCE_INLINE_ void operator=(int64_t p_int64) { id = p_int64; }
-	_FORCE_INLINE_ void operator=(uint64_t p_uint64) { id = p_uint64; }
-
-	_FORCE_INLINE_ ObjectID() {}
-	_FORCE_INLINE_ explicit ObjectID(const uint64_t p_id) { id = p_id; }
-	_FORCE_INLINE_ explicit ObjectID(const int64_t p_id) { id = p_id; }
-};
-
 class ObjectDB {
 public:
 	static Object *get_instance(uint64_t p_object_id) {

include/godot_cpp/core/object_id.hpp

@@ -0,0 +1,62 @@
+/**************************************************************************/
+/*  object_id.hpp                                                         */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef GODOT_OBJECT_ID_HPP
+#define GODOT_OBJECT_ID_HPP
+
+#include <godot_cpp/core/defs.hpp>
+
+namespace godot {
+
+class ObjectID {
+	uint64_t id = 0;
+
+public:
+	_FORCE_INLINE_ bool is_ref_counted() const { return (id & (uint64_t(1) << 63)) != 0; }
+	_FORCE_INLINE_ bool is_valid() const { return id != 0; }
+	_FORCE_INLINE_ bool is_null() const { return id == 0; }
+	_FORCE_INLINE_ operator uint64_t() const { return id; }
+	_FORCE_INLINE_ operator int64_t() const { return id; }
+
+	_FORCE_INLINE_ bool operator==(const ObjectID &p_id) const { return id == p_id.id; }
+	_FORCE_INLINE_ bool operator!=(const ObjectID &p_id) const { return id != p_id.id; }
+	_FORCE_INLINE_ bool operator<(const ObjectID &p_id) const { return id < p_id.id; }
+
+	_FORCE_INLINE_ void operator=(int64_t p_int64) { id = p_int64; }
+	_FORCE_INLINE_ void operator=(uint64_t p_uint64) { id = p_uint64; }
+
+	_FORCE_INLINE_ ObjectID() {}
+	_FORCE_INLINE_ explicit ObjectID(const uint64_t p_id) { id = p_id; }
+	_FORCE_INLINE_ explicit ObjectID(const int64_t p_id) { id = p_id; }
+};
+
+} // namespace godot
+
+#endif // GODOT_OBJECT_ID_HPP

include/godot_cpp/core/property_info.hpp

@@ -68,6 +68,18 @@ struct PropertyInfo {
 
 	PropertyInfo(GDExtensionVariantType p_type, const StringName &p_name, PropertyHint p_hint = PROPERTY_HINT_NONE, const String &p_hint_string = "", uint32_t p_usage = PROPERTY_USAGE_DEFAULT, const StringName &p_class_name = "") :
 			PropertyInfo((Variant::Type)p_type, p_name, p_hint, p_hint_string, p_usage, p_class_name) {}
+
+	PropertyInfo(const GDExtensionPropertyInfo *p_info) :
+			PropertyInfo(p_info->type, *reinterpret_cast<StringName *>(p_info->name), (PropertyHint)p_info->hint, *reinterpret_cast<String *>(p_info->hint_string), p_info->usage, *reinterpret_cast<StringName *>(p_info->class_name)) {}
+
+	void _update(GDExtensionPropertyInfo *p_info) {
+		p_info->type = (GDExtensionVariantType)type;
+		*(reinterpret_cast<StringName *>(p_info->name)) = name;
+		p_info->hint = hint;
+		*(reinterpret_cast<String *>(p_info->hint_string)) = hint_string;
+		p_info->usage = usage;
+		*(reinterpret_cast<StringName *>(p_info->class_name)) = class_name;
+	}
 };
 
 } // namespace godot

include/godot_cpp/godot.hpp

@@ -123,6 +123,8 @@ extern "C" GDExtensionInterfaceStringOperatorPlusEqChar gdextension_interface_st
 extern "C" GDExtensionInterfaceStringOperatorPlusEqCstr gdextension_interface_string_operator_plus_eq_cstr;
 extern "C" GDExtensionInterfaceStringOperatorPlusEqWcstr gdextension_interface_string_operator_plus_eq_wcstr;
 extern "C" GDExtensionInterfaceStringOperatorPlusEqC32str gdextension_interface_string_operator_plus_eq_c32str;
+extern "C" GDExtensionInterfaceStringResize gdextension_interface_string_resize;
+extern "C" GDExtensionInterfaceStringNameNewWithLatin1Chars gdextension_interface_string_name_new_with_latin1_chars;
 extern "C" GDExtensionInterfaceXmlParserOpenBuffer gdextension_interface_xml_parser_open_buffer;
 extern "C" GDExtensionInterfaceFileAccessStoreBuffer gdextension_interface_file_access_store_buffer;
 extern "C" GDExtensionInterfaceFileAccessGetBuffer gdextension_interface_file_access_get_buffer;
@@ -163,16 +165,21 @@ 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" 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" GDExtensionInterfaceScriptInstanceCreate gdextension_interface_script_instance_create;
+extern "C" GDExtensionInterfaceScriptInstanceCreate2 gdextension_interface_script_instance_create2;
+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;
 extern "C" GDExtensionInterfaceClassdbGetMethodBind gdextension_interface_classdb_get_method_bind;
 extern "C" GDExtensionInterfaceClassdbGetClassTag gdextension_interface_classdb_get_class_tag;
-extern "C" GDExtensionInterfaceClassdbRegisterExtensionClass gdextension_interface_classdb_register_extension_class;
+extern "C" GDExtensionInterfaceClassdbRegisterExtensionClass2 gdextension_interface_classdb_register_extension_class2;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassMethod gdextension_interface_classdb_register_extension_class_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;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassPropertyGroup gdextension_interface_classdb_register_extension_class_property_group;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassPropertySubgroup gdextension_interface_classdb_register_extension_class_property_subgroup;
 extern "C" GDExtensionInterfaceClassdbRegisterExtensionClassSignal gdextension_interface_classdb_register_extension_class_signal;
@@ -187,29 +194,44 @@ enum ModuleInitializationLevel {
 	MODULE_INITIALIZATION_LEVEL_CORE = GDEXTENSION_INITIALIZATION_CORE,
 	MODULE_INITIALIZATION_LEVEL_SERVERS = GDEXTENSION_INITIALIZATION_SERVERS,
 	MODULE_INITIALIZATION_LEVEL_SCENE = GDEXTENSION_INITIALIZATION_SCENE,
-	MODULE_INITIALIZATION_LEVEL_EDITOR = GDEXTENSION_INITIALIZATION_EDITOR
+	MODULE_INITIALIZATION_LEVEL_EDITOR = GDEXTENSION_INITIALIZATION_EDITOR,
+	MODULE_INITIALIZATION_LEVEL_MAX
 };
 
 class GDExtensionBinding {
-private:
-	static void register_engine_classes();
-
 public:
 	using Callback = void (*)(ModuleInitializationLevel p_level);
 
-	static Callback init_callback;
-	static Callback terminate_callback;
-	static GDExtensionInitializationLevel minimum_initialization_level;
-	static GDExtensionBool init(GDExtensionInterfaceGetProcAddress p_get_proc_address, GDExtensionClassLibraryPtr p_library, GDExtensionInitialization *r_initialization);
+	struct InitData {
+		GDExtensionInitializationLevel minimum_initialization_level = GDEXTENSION_INITIALIZATION_CORE;
+		Callback init_callback = nullptr;
+		Callback terminate_callback = nullptr;
+	};
+
+	class InitDataList {
+		int data_count = 0;
+		int data_capacity = 0;
+		InitData **data = nullptr;
+
+	public:
+		void add(InitData *p_cb);
+		~InitDataList();
+	};
+
+	static bool api_initialized;
+	static int level_initialized[MODULE_INITIALIZATION_LEVEL_MAX];
+	static InitDataList initdata;
+	static GDExtensionBool init(GDExtensionInterfaceGetProcAddress p_get_proc_address, GDExtensionClassLibraryPtr p_library, InitData *p_init_data, GDExtensionInitialization *r_initialization);
 
 public:
-	static void initialize_level(void *userdata, GDExtensionInitializationLevel p_level);
-	static void deinitialize_level(void *userdata, GDExtensionInitializationLevel p_level);
+	static void initialize_level(void *p_userdata, GDExtensionInitializationLevel p_level);
+	static void deinitialize_level(void *p_userdata, GDExtensionInitializationLevel p_level);
 
 	class InitObject {
 		GDExtensionInterfaceGetProcAddress get_proc_address;
 		GDExtensionClassLibraryPtr library;
 		GDExtensionInitialization *initialization;
+		mutable InitData *init_data = nullptr;
 
 	public:
 		InitObject(GDExtensionInterfaceGetProcAddress p_get_proc_address, GDExtensionClassLibraryPtr p_library, GDExtensionInitialization *r_initialization);

include/godot_cpp/templates/cowdata.hpp

@@ -32,13 +32,14 @@
 #define GODOT_COWDATA_HPP
 
 #include <godot_cpp/classes/global_constants.hpp>
-#include <godot_cpp/core/class_db.hpp>
 #include <godot_cpp/core/error_macros.hpp>
 #include <godot_cpp/core/math.hpp>
 #include <godot_cpp/core/memory.hpp>
 #include <godot_cpp/templates/safe_refcount.hpp>
 
 #include <cstring>
+#include <new>
+#include <type_traits>
 
 namespace godot {
 
@@ -48,6 +49,9 @@ class Vector;
 template <class T, class V>
 class VMap;
 
+template <class T>
+class CharStringT;
+
 // Silence a false positive warning (see GH-52119).
 #if defined(__GNUC__) && !defined(__clang__)
 #pragma GCC diagnostic push
@@ -62,6 +66,9 @@ class CowData {
 	template <class TV, class VV>
 	friend class VMap;
 
+	template <class TS>
+	friend class CharStringT;
+
 private:
 	mutable T *_ptr = nullptr;
 
@@ -95,6 +102,10 @@ private:
 	}
 
 	_FORCE_INLINE_ bool _get_alloc_size_checked(size_t p_elements, size_t *out) const {
+		if (unlikely(p_elements == 0)) {
+			*out = 0;
+			return true;
+		}
 #if defined(__GNUC__)
 		size_t o;
 		size_t p;
@@ -106,13 +117,12 @@ private:
 		if (__builtin_add_overflow(o, static_cast<size_t>(32), &p)) {
 			return false; // No longer allocated here.
 		}
-		return true;
 #else
 		// Speed is more important than correctness here, do the operations unchecked
 		// and hope for the best.
 		*out = _get_alloc_size(p_elements);
-		return true;
 #endif
+		return *out;
 	}
 
 	void _unref(void *p_data);
@@ -204,9 +214,9 @@ void CowData<T>::_unref(void *p_data) {
 	if (refc->decrement() > 0) {
 		return; // still in use
 	}
-	// clean up
 
-	if (!__has_trivial_destructor(T)) {
+	// clean up
+	if (!std::is_trivially_destructible<T>::value) {
 		uint32_t *count = _get_size();
 		T *data = (T *)(count + 1);
 
@@ -241,7 +251,7 @@ uint32_t CowData<T>::_copy_on_write() {
 		T *_data = (T *)(mem_new);
 
 		// initialize new elements
-		if (__has_trivial_copy(T)) {
+		if (std::is_trivially_copyable<T>::value) {
 			memcpy(mem_new, _ptr, current_size * sizeof(T));
 
 		} else {
@@ -287,7 +297,7 @@ Error CowData<T>::resize(int p_size) {
 			if (current_size == 0) {
 				// alloc from scratch
 				uint32_t *ptr = (uint32_t *)Memory::alloc_static(alloc_size, true);
-				ERR_FAIL_COND_V(!ptr, ERR_OUT_OF_MEMORY);
+				ERR_FAIL_NULL_V(ptr, ERR_OUT_OF_MEMORY);
 				*(ptr - 1) = 0; // size, currently none
 				new (ptr - 2) SafeNumeric<uint32_t>(1); // refcount
 
@@ -295,7 +305,7 @@ Error CowData<T>::resize(int p_size) {
 
 			} else {
 				uint32_t *_ptrnew = (uint32_t *)Memory::realloc_static(_ptr, alloc_size, true);
-				ERR_FAIL_COND_V(!_ptrnew, ERR_OUT_OF_MEMORY);
+				ERR_FAIL_NULL_V(_ptrnew, ERR_OUT_OF_MEMORY);
 				new (_ptrnew - 2) SafeNumeric<uint32_t>(rc); // refcount
 
 				_ptr = (T *)(_ptrnew);
@@ -304,7 +314,7 @@ Error CowData<T>::resize(int p_size) {
 
 		// construct the newly created elements
 
-		if (!__has_trivial_constructor(T)) {
+		if (!std::is_trivially_constructible<T>::value) {
 			T *elems = _get_data();
 
 			for (int i = *_get_size(); i < p_size; i++) {
@@ -315,7 +325,7 @@ Error CowData<T>::resize(int p_size) {
 		*_get_size() = p_size;
 
 	} else if (p_size < current_size) {
-		if (!__has_trivial_destructor(T)) {
+		if (!std::is_trivially_destructible<T>::value) {
 			// deinitialize no longer needed elements
 			for (uint32_t i = p_size; i < *_get_size(); i++) {
 				T *t = &_get_data()[i];
@@ -325,7 +335,7 @@ Error CowData<T>::resize(int p_size) {
 
 		if (alloc_size != current_alloc_size) {
 			uint32_t *_ptrnew = (uint32_t *)Memory::realloc_static(_ptr, alloc_size, true);
-			ERR_FAIL_COND_V(!_ptrnew, ERR_OUT_OF_MEMORY);
+			ERR_FAIL_NULL_V(_ptrnew, ERR_OUT_OF_MEMORY);
 			new (_ptrnew - 2) SafeNumeric<uint32_t>(rc); // refcount
 
 			_ptr = (T *)(_ptrnew);

include/godot_cpp/templates/list.hpp

@@ -221,7 +221,7 @@ private:
 		int size_cache = 0;
 
 		bool erase(const Element *p_I) {
-			ERR_FAIL_COND_V(!p_I, false);
+			ERR_FAIL_NULL_V(p_I, false);
 			ERR_FAIL_COND_V(p_I->data != this, false);
 
 			if (first == p_I) {

include/godot_cpp/templates/rid_owner.hpp

@@ -186,12 +186,12 @@ public:
 	}
 	void initialize_rid(RID p_rid) {
 		T *mem = get_or_null(p_rid, true);
-		ERR_FAIL_COND(!mem);
+		ERR_FAIL_NULL(mem);
 		memnew_placement(mem, T);
 	}
 	void initialize_rid(RID p_rid, const T &p_value) {
 		T *mem = get_or_null(p_rid, true);
-		ERR_FAIL_COND(!mem);
+		ERR_FAIL_NULL(mem);
 		memnew_placement(mem, T(p_value));
 	}
 
@@ -374,7 +374,7 @@ public:
 
 	_FORCE_INLINE_ void replace(const RID &p_rid, T *p_new_ptr) {
 		T **ptr = alloc.get_or_null(p_rid);
-		ERR_FAIL_COND(!ptr);
+		ERR_FAIL_NULL(ptr);
 		*ptr = p_new_ptr;
 	}
 

include/godot_cpp/templates/thread_work_pool.hpp

@@ -96,7 +96,7 @@ class ThreadWorkPool {
 public:
 	template <class C, class M, class U>
 	void begin_work(uint32_t p_elements, C *p_instance, M p_method, U p_userdata) {
-		ERR_FAIL_COND(!threads); // never initialized
+		ERR_FAIL_NULL(threads); // Never initialized.
 		ERR_FAIL_COND(current_work != nullptr);
 
 		index.store(0, std::memory_order_release);
@@ -123,18 +123,18 @@ public:
 	}
 
 	bool is_done_dispatching() const {
-		ERR_FAIL_COND_V(current_work == nullptr, true);
+		ERR_FAIL_NULL_V(current_work, true);
 		return index.load(std::memory_order_acquire) >= current_work->max_elements;
 	}
 
 	uint32_t get_work_index() const {
-		ERR_FAIL_COND_V(current_work == nullptr, 0);
+		ERR_FAIL_NULL_V(current_work, 0);
 		uint32_t idx = index.load(std::memory_order_acquire);
 		return Math::min(idx, current_work->max_elements);
 	}
 
 	void end_work() {
-		ERR_FAIL_COND(current_work == nullptr);
+		ERR_FAIL_NULL(current_work);
 		for (uint32_t i = 0; i < threads_working; i++) {
 			threads[i].completed.wait();
 			threads[i].work = nullptr;

include/godot_cpp/variant/callable_custom.hpp

@@ -0,0 +1,64 @@
+/**************************************************************************/
+/*  callable_custom.hpp                                                   */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef GODOT_CALLABLE_CUSTOM_HPP
+#define GODOT_CALLABLE_CUSTOM_HPP
+
+#include <godot_cpp/core/object_id.hpp>
+#include <godot_cpp/variant/string_name.hpp>
+
+namespace godot {
+
+class Object;
+
+class CallableCustomBase {
+public:
+	virtual ObjectID get_object() const = 0;
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const = 0;
+	virtual ~CallableCustomBase() {}
+};
+
+class CallableCustom : public CallableCustomBase {
+public:
+	typedef bool (*CompareEqualFunc)(const CallableCustom *p_a, const CallableCustom *p_b);
+	typedef bool (*CompareLessFunc)(const CallableCustom *p_a, const CallableCustom *p_b);
+
+	virtual uint32_t hash() const = 0;
+	virtual String get_as_text() const = 0;
+	virtual CompareEqualFunc get_compare_equal_func() const = 0;
+	virtual CompareLessFunc get_compare_less_func() const = 0;
+	virtual bool is_valid() const;
+	virtual ObjectID get_object() const = 0;
+	virtual void call(const Variant **p_arguments, int p_argcount, Variant &r_return_value, GDExtensionCallError &r_call_error) const = 0;
+};
+
+} // namespace godot
+
+#endif // GODOT_CALLABLE_CUSTOM_HPP

include/godot_cpp/variant/callable_method_pointer.hpp

@@ -0,0 +1,248 @@
+/**************************************************************************/
+/*  callable_method_pointer.hpp                                           */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef GODOT_CALLABLE_METHOD_POINTER_HPP
+#define GODOT_CALLABLE_METHOD_POINTER_HPP
+
+#include <godot_cpp/core/binder_common.hpp>
+#include <godot_cpp/variant/variant.hpp>
+
+namespace godot {
+
+class CallableCustomMethodPointerBase : public CallableCustomBase {
+	uint32_t *comp_ptr = nullptr;
+	uint32_t comp_size;
+	uint32_t h;
+
+protected:
+	void _setup(uint32_t *p_base_ptr, uint32_t p_ptr_size);
+
+public:
+	_FORCE_INLINE_ const uint32_t *get_comp_ptr() const { return comp_ptr; }
+	_FORCE_INLINE_ uint32_t get_comp_size() const { return comp_size; }
+	_FORCE_INLINE_ uint32_t get_hash() const { return h; }
+};
+
+namespace internal {
+
+Callable create_callable_from_ccmp(CallableCustomMethodPointerBase *p_callable_method_pointer);
+
+} // namespace internal
+
+//
+// No return value.
+//
+
+template <class T, class... P>
+class CallableCustomMethodPointer : public CallableCustomMethodPointerBase {
+	struct Data {
+		T *instance;
+		void (T::*method)(P...);
+	} data;
+	static_assert(sizeof(Data) % 4 == 0);
+
+public:
+	virtual ObjectID get_object() const override {
+		return ObjectID(data.instance->get_instance_id());
+	}
+
+	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);
+	}
+
+	CallableCustomMethodPointer(T *p_instance, void (T::*p_method)(P...)) {
+		memset(&data, 0, sizeof(Data));
+		data.instance = p_instance;
+		data.method = p_method;
+		_setup((uint32_t *)&data, sizeof(Data));
+	}
+};
+
+template <class T, class... P>
+Callable create_custom_callable_function_pointer(T *p_instance, void (T::*p_method)(P...)) {
+	typedef CallableCustomMethodPointer<T, P...> CCMP;
+	CCMP *ccmp = memnew(CCMP(p_instance, p_method));
+	return ::godot::internal::create_callable_from_ccmp(ccmp);
+}
+
+//
+// With return value.
+//
+
+template <class T, class R, class... P>
+class CallableCustomMethodPointerRet : public CallableCustomMethodPointerBase {
+	struct Data {
+		T *instance;
+		R(T::*method)
+		(P...);
+	} data;
+	static_assert(sizeof(Data) % 4 == 0);
+
+public:
+	virtual ObjectID get_object() const override {
+		return ObjectID(data.instance->get_instance_id());
+	}
+
+	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);
+	}
+
+	CallableCustomMethodPointerRet(T *p_instance, R (T::*p_method)(P...)) {
+		memset(&data, 0, sizeof(Data));
+		data.instance = p_instance;
+		data.method = p_method;
+		_setup((uint32_t *)&data, sizeof(Data));
+	}
+};
+
+template <class T, class R, class... P>
+Callable create_custom_callable_function_pointer(T *p_instance, R (T::*p_method)(P...)) {
+	typedef CallableCustomMethodPointerRet<T, R, P...> CCMP; // Messes with memnew otherwise.
+	CCMP *ccmp = memnew(CCMP(p_instance, p_method));
+	return ::godot::internal::create_callable_from_ccmp(ccmp);
+}
+
+//
+// Const with return value.
+//
+
+template <class T, class R, class... P>
+class CallableCustomMethodPointerRetC : public CallableCustomMethodPointerBase {
+	struct Data {
+		T *instance;
+		R(T::*method)
+		(P...) const;
+	} data;
+	static_assert(sizeof(Data) % 4 == 0);
+
+public:
+	virtual ObjectID get_object() const override {
+		return ObjectID(data.instance->get_instance_id());
+	}
+
+	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);
+	}
+
+	CallableCustomMethodPointerRetC(const T *p_instance, R (T::*p_method)(P...) const) {
+		memset(&data, 0, sizeof(Data));
+		data.instance = const_cast<T *>(p_instance);
+		data.method = p_method;
+		_setup((uint32_t *)&data, sizeof(Data));
+	}
+};
+
+template <class T, class R, class... P>
+Callable create_custom_callable_function_pointer(const T *p_instance, R (T::*p_method)(P...) const) {
+	typedef CallableCustomMethodPointerRetC<T, R, P...> CCMP; // Messes with memnew otherwise.
+	CCMP *ccmp = memnew(CCMP(p_instance, p_method));
+	return ::godot::internal::create_callable_from_ccmp(ccmp);
+}
+
+//
+// Static method with no return value.
+//
+
+template <class... P>
+class CallableCustomStaticMethodPointer : public CallableCustomMethodPointerBase {
+	struct Data {
+		void (*method)(P...);
+	} data;
+	static_assert(sizeof(Data) % 4 == 0);
+
+public:
+	virtual ObjectID get_object() const override {
+		return ObjectID();
+	}
+
+	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();
+	}
+
+	CallableCustomStaticMethodPointer(void (*p_method)(P...)) {
+		memset(&data, 0, sizeof(Data));
+		data.method = p_method;
+		_setup((uint32_t *)&data, sizeof(Data));
+	}
+};
+
+template <class... P>
+Callable create_custom_callable_static_function_pointer(void (*p_method)(P...)) {
+	typedef CallableCustomStaticMethodPointer<P...> CCMP;
+	CCMP *ccmp = memnew(CCMP(p_method));
+	return ::godot::internal::create_callable_from_ccmp(ccmp);
+}
+
+//
+// Static method with return value.
+//
+
+template <class R, class... P>
+class CallableCustomStaticMethodPointerRet : public CallableCustomMethodPointerBase {
+	struct Data {
+		R(*method)
+		(P...);
+	} data;
+	static_assert(sizeof(Data) % 4 == 0);
+
+public:
+	virtual ObjectID get_object() const override {
+		return ObjectID();
+	}
+
+	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);
+	}
+
+	CallableCustomStaticMethodPointerRet(R (*p_method)(P...)) {
+		memset(&data, 0, sizeof(Data));
+		data.method = p_method;
+		_setup((uint32_t *)&data, sizeof(Data));
+	}
+};
+
+template <class R, class... P>
+Callable create_custom_callable_static_function_pointer(R (*p_method)(P...)) {
+	typedef CallableCustomStaticMethodPointerRet<R, P...> CCMP;
+	CCMP *ccmp = memnew(CCMP(p_method));
+	return ::godot::internal::create_callable_from_ccmp(ccmp);
+}
+
+//
+// The API:
+//
+
+#define callable_mp(I, M) ::godot::create_custom_callable_function_pointer(I, M)
+#define callable_mp_static(M) ::godot::create_custom_callable_static_function_pointer(M)
+
+} // namespace godot
+
+#endif // GODOT_CALLABLE_METHOD_POINTER_HPP

include/godot_cpp/variant/char_string.hpp

@@ -31,82 +31,111 @@
 #ifndef GODOT_CHAR_STRING_HPP
 #define GODOT_CHAR_STRING_HPP
 
+#include <godot_cpp/templates/cowdata.hpp>
+
 #include <cstddef>
 #include <cstdint>
 
 namespace godot {
 
-class CharString {
-	friend class String;
+template <class T>
+class CharStringT;
 
-	const char *_data = nullptr;
-	int _length = 0;
+template <class T>
+class CharProxy {
+	template <class TS>
+	friend class CharStringT;
 
-	CharString(const char *str, int length);
+	const int _index;
+	CowData<T> &_cowdata;
+	static inline const T _null = 0;
+
+	_FORCE_INLINE_ CharProxy(const int &p_index, CowData<T> &p_cowdata) :
+			_index(p_index),
+			_cowdata(p_cowdata) {}
 
 public:
-	int length() const;
-	const char *get_data() const;
+	_FORCE_INLINE_ CharProxy(const CharProxy<T> &p_other) :
+			_index(p_other._index),
+			_cowdata(p_other._cowdata) {}
 
-	CharString(CharString &&p_str);
-	void operator=(CharString &&p_str);
-	CharString() {}
-	~CharString();
+	_FORCE_INLINE_ operator T() const {
+		if (unlikely(_index == _cowdata.size())) {
+			return _null;
+		}
+
+		return _cowdata.get(_index);
+	}
+
+	_FORCE_INLINE_ const T *operator&() const {
+		return _cowdata.ptr() + _index;
+	}
+
+	_FORCE_INLINE_ void operator=(const T &p_other) const {
+		_cowdata.set(_index, p_other);
+	}
+
+	_FORCE_INLINE_ void operator=(const CharProxy<T> &p_other) const {
+		_cowdata.set(_index, p_other.operator T());
+	}
 };
 
-class Char16String {
+template <class T>
+class CharStringT {
 	friend class String;
 
-	const char16_t *_data = nullptr;
-	int _length = 0;
-
-	Char16String(const char16_t *str, int length);
+	CowData<T> _cowdata;
+	static inline const T _null = 0;
 
 public:
-	int length() const;
-	const char16_t *get_data() const;
+	_FORCE_INLINE_ T *ptrw() { return _cowdata.ptrw(); }
+	_FORCE_INLINE_ const T *ptr() const { return _cowdata.ptr(); }
+	_FORCE_INLINE_ int size() const { return _cowdata.size(); }
+	Error resize(int p_size) { return _cowdata.resize(p_size); }
 
-	Char16String(Char16String &&p_str);
-	void operator=(Char16String &&p_str);
-	Char16String() {}
-	~Char16String();
+	_FORCE_INLINE_ T get(int p_index) const { return _cowdata.get(p_index); }
+	_FORCE_INLINE_ void set(int p_index, const T &p_elem) { _cowdata.set(p_index, p_elem); }
+	_FORCE_INLINE_ const T &operator[](int p_index) const {
+		if (unlikely(p_index == _cowdata.size())) {
+			return _null;
+		}
+
+		return _cowdata.get(p_index);
+	}
+	_FORCE_INLINE_ CharProxy<T> operator[](int p_index) { return CharProxy<T>(p_index, _cowdata); }
+
+	_FORCE_INLINE_ CharStringT() {}
+	_FORCE_INLINE_ CharStringT(const CharStringT<T> &p_str) { _cowdata._ref(p_str._cowdata); }
+	_FORCE_INLINE_ void operator=(const CharStringT<T> &p_str) { _cowdata._ref(p_str._cowdata); }
+	_FORCE_INLINE_ CharStringT(const T *p_cstr) { copy_from(p_cstr); }
+
+	void operator=(const T *p_cstr);
+	bool operator<(const CharStringT<T> &p_right) const;
+	CharStringT<T> &operator+=(T p_char);
+	int length() const { return size() ? size() - 1 : 0; }
+	const T *get_data() const;
+	operator const T *() const { return get_data(); };
+
+protected:
+	void copy_from(const T *p_cstr);
 };
 
-class Char32String {
-	friend class String;
+template <>
+const char *CharStringT<char>::get_data() const;
 
-	const char32_t *_data = nullptr;
-	int _length = 0;
+template <>
+const char16_t *CharStringT<char16_t>::get_data() const;
 
-	Char32String(const char32_t *str, int length);
+template <>
+const char32_t *CharStringT<char32_t>::get_data() const;
 
-public:
-	int length() const;
-	const char32_t *get_data() const;
+template <>
+const wchar_t *CharStringT<wchar_t>::get_data() const;
 
-	Char32String(Char32String &&p_str);
-	void operator=(Char32String &&p_str);
-	Char32String() {}
-	~Char32String();
-};
-
-class CharWideString {
-	friend class String;
-
-	const wchar_t *_data = nullptr;
-	int _length = 0;
-
-	CharWideString(const wchar_t *str, int length);
-
-public:
-	int length() const;
-	const wchar_t *get_data() const;
-
-	CharWideString(CharWideString &&p_str);
-	void operator=(CharWideString &&p_str);
-	CharWideString() {}
-	~CharWideString();
-};
+typedef CharStringT<char> CharString;
+typedef CharStringT<char16_t> Char16String;
+typedef CharStringT<char32_t> Char32String;
+typedef CharStringT<wchar_t> CharWideString;
 
 } // namespace godot
 

include/godot_cpp/variant/variant.hpp

@@ -154,10 +154,18 @@ public:
 	Variant(int64_t v);
 	Variant(int32_t v) :
 			Variant(static_cast<int64_t>(v)) {}
-	Variant(uint32_t v) :
+	Variant(int16_t v) :
+			Variant(static_cast<int64_t>(v)) {}
+	Variant(int8_t v) :
 			Variant(static_cast<int64_t>(v)) {}
 	Variant(uint64_t v) :
 			Variant(static_cast<int64_t>(v)) {}
+	Variant(uint32_t v) :
+			Variant(static_cast<int64_t>(v)) {}
+	Variant(uint16_t v) :
+			Variant(static_cast<int64_t>(v)) {}
+	Variant(uint8_t v) :
+			Variant(static_cast<int64_t>(v)) {}
 	Variant(double v);
 	Variant(float v) :
 			Variant((double)v) {}
@@ -209,8 +217,12 @@ public:
 	operator bool() const;
 	operator int64_t() const;
 	operator int32_t() const;
+	operator int16_t() const;
+	operator int8_t() const;
 	operator uint64_t() const;
 	operator uint32_t() const;
+	operator uint16_t() const;
+	operator uint8_t() const;
 	operator double() const;
 	operator float() const;
 	operator String() const;
@@ -255,25 +267,33 @@ public:
 	bool operator!=(const Variant &other) const;
 	bool operator<(const Variant &other) const;
 
-	void call(const StringName &method, const Variant **args, int argcount, Variant &r_ret, GDExtensionCallError &r_error);
+	void callp(const StringName &method, const Variant **args, int argcount, Variant &r_ret, GDExtensionCallError &r_error);
 
 	template <class... Args>
 	Variant call(const StringName &method, Args... args) {
+		std::array<Variant, sizeof...(args)> vargs = { args... };
+		std::array<const Variant *, sizeof...(args)> argptrs;
+		for (size_t i = 0; i < vargs.size(); i++) {
+			argptrs[i] = &vargs[i];
+		}
 		Variant result;
 		GDExtensionCallError error;
-		std::array<GDExtensionConstVariantPtr, sizeof...(Args)> call_args = { Variant(args)... };
-		call(method, call_args.data(), call_args.size(), result, error);
+		callp(method, argptrs.data(), argptrs.size(), result, error);
 		return result;
 	}
 
-	static void call_static(Variant::Type type, const StringName &method, const Variant **args, int argcount, Variant &r_ret, GDExtensionCallError &r_error);
+	static void callp_static(Variant::Type type, const StringName &method, const Variant **args, int argcount, Variant &r_ret, GDExtensionCallError &r_error);
 
 	template <class... Args>
 	static Variant call_static(Variant::Type type, const StringName &method, Args... args) {
+		std::array<Variant, sizeof...(args)> vargs = { args... };
+		std::array<const Variant *, sizeof...(args)> argptrs;
+		for (size_t i = 0; i < vargs.size(); i++) {
+			argptrs[i] = &vargs[i];
+		}
 		Variant result;
 		GDExtensionCallError error;
-		std::array<GDExtensionConstVariantPtr, sizeof...(Args)> call_args = { Variant(args)... };
-		call_static(type, method, call_args.data(), call_args.size(), result, error);
+		callp_static(type, method, argptrs.data(), argptrs.size(), sizeof...(args), result, error);
 		return result;
 	}
 
@@ -334,6 +354,8 @@ String vformat(const String &p_text, const VarArgs... p_args) {
 	return p_text % args_array;
 }
 
+#include <godot_cpp/variant/builtin_vararg_methods.hpp>
+
 } // namespace godot
 
 #endif // GODOT_VARIANT_HPP

include/godot_cpp/variant/vector3.hpp

@@ -78,6 +78,14 @@ struct _NO_DISCARD_ Vector3 {
 		return x < y ? (y < z ? Vector3::AXIS_Z : Vector3::AXIS_Y) : (x < z ? Vector3::AXIS_Z : Vector3::AXIS_X);
 	}
 
+	Vector3 min(const Vector3 &p_vector3) const {
+		return Vector3(MIN(x, p_vector3.x), MIN(y, p_vector3.y), MIN(z, p_vector3.z));
+	}
+
+	Vector3 max(const Vector3 &p_vector3) const {
+		return Vector3(MAX(x, p_vector3.x), MAX(y, p_vector3.y), MAX(z, p_vector3.z));
+	}
+
 	_FORCE_INLINE_ real_t length() const;
 	_FORCE_INLINE_ real_t length_squared() const;
 

include/godot_cpp/variant/vector3i.hpp

@@ -71,6 +71,14 @@ struct _NO_DISCARD_ Vector3i {
 	Vector3i::Axis min_axis_index() const;
 	Vector3i::Axis max_axis_index() const;
 
+	Vector3i min(const Vector3i &p_vector3i) const {
+		return Vector3i(MIN(x, p_vector3i.x), MIN(y, p_vector3i.y), MIN(z, p_vector3i.z));
+	}
+
+	Vector3i max(const Vector3i &p_vector3i) const {
+		return Vector3i(MAX(x, p_vector3i.x), MAX(y, p_vector3i.y), MAX(z, p_vector3i.z));
+	}
+
 	_FORCE_INLINE_ int64_t length_squared() const;
 	_FORCE_INLINE_ double length() const;
 

include/godot_cpp/variant/vector4.hpp

@@ -70,6 +70,14 @@ struct _NO_DISCARD_ Vector4 {
 	Vector4::Axis min_axis_index() const;
 	Vector4::Axis max_axis_index() const;
 
+	Vector4 min(const Vector4 &p_vector4) const {
+		return Vector4(MIN(x, p_vector4.x), MIN(y, p_vector4.y), MIN(z, p_vector4.z), MIN(w, p_vector4.w));
+	}
+
+	Vector4 max(const Vector4 &p_vector4) const {
+		return Vector4(MAX(x, p_vector4.x), MAX(y, p_vector4.y), MAX(z, p_vector4.z), MAX(w, p_vector4.w));
+	}
+
 	_FORCE_INLINE_ real_t length_squared() const;
 	bool is_equal_approx(const Vector4 &p_vec4) const;
 	bool is_zero_approx() const;

include/godot_cpp/variant/vector4i.hpp

@@ -73,6 +73,14 @@ struct _NO_DISCARD_ Vector4i {
 	Vector4i::Axis min_axis_index() const;
 	Vector4i::Axis max_axis_index() const;
 
+	Vector4i min(const Vector4i &p_vector4i) const {
+		return Vector4i(MIN(x, p_vector4i.x), MIN(y, p_vector4i.y), MIN(z, p_vector4i.z), MIN(w, p_vector4i.w));
+	}
+
+	Vector4i max(const Vector4i &p_vector4i) const {
+		return Vector4i(MAX(x, p_vector4i.x), MAX(y, p_vector4i.y), MAX(z, p_vector4i.z), MAX(w, p_vector4i.w));
+	}
+
 	_FORCE_INLINE_ int64_t length_squared() const;
 	_FORCE_INLINE_ double length() const;
 

src/classes/editor_plugin_registration.cpp

@@ -1,5 +1,5 @@
 /**************************************************************************/
-/*  editor_plugin.cpp                                                     */
+/*  editor_plugin_registration.cpp                                        */
 /**************************************************************************/
 /*                         This file is part of:                          */
 /*                             GODOT ENGINE                               */
@@ -28,9 +28,9 @@
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
 /**************************************************************************/
 
-#include <godot_cpp/classes/editor_plugin.hpp>
+#include <godot_cpp/classes/editor_plugin_registration.hpp>
 
-#include <godot_cpp/variant/string_name.hpp>
+#include <godot_cpp/variant/variant.hpp>
 
 namespace godot {
 

src/classes/wrapped.cpp

@@ -28,12 +28,16 @@
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
 /**************************************************************************/
 
+#include <vector>
+
 #include <godot_cpp/classes/wrapped.hpp>
 
 #include <godot_cpp/variant/builtin_types.hpp>
 
 #include <godot_cpp/classes/object.hpp>
 
+#include <godot_cpp/core/class_db.hpp>
+
 namespace godot {
 
 const StringName *Wrapped::_get_extension_class_name() const {
@@ -46,9 +50,34 @@ void Wrapped::_postinitialize() {
 		godot::internal::gdextension_interface_object_set_instance(_owner, reinterpret_cast<GDExtensionConstStringNamePtr>(extension_class), this);
 	}
 	godot::internal::gdextension_interface_object_set_instance_binding(_owner, godot::internal::token, this, _get_bindings_callbacks());
+	if (extension_class) {
+		Object *obj = dynamic_cast<Object *>(this);
+		if (obj) {
+			obj->notification(Object::NOTIFICATION_POSTINITIALIZE);
+		}
+	}
 }
 
 Wrapped::Wrapped(const StringName p_godot_class) {
+#ifdef HOT_RELOAD_ENABLED
+	if (unlikely(Wrapped::recreate_instance)) {
+		RecreateInstance *recreate_data = Wrapped::recreate_instance;
+		RecreateInstance *previous = nullptr;
+		while (recreate_data) {
+			if (recreate_data->wrapper == this) {
+				_owner = recreate_data->owner;
+				if (previous) {
+					previous->next = recreate_data->next;
+				} else {
+					Wrapped::recreate_instance = recreate_data->next;
+				}
+				return;
+			}
+			previous = recreate_data;
+			recreate_data = recreate_data->next;
+		}
+	}
+#endif
 	_owner = godot::internal::gdextension_interface_classdb_construct_object(reinterpret_cast<GDExtensionConstStringNamePtr>(p_godot_class._native_ptr()));
 }
 
@@ -60,4 +89,54 @@ void postinitialize_handler(Wrapped *p_wrapped) {
 	p_wrapped->_postinitialize();
 }
 
+namespace internal {
+
+std::vector<EngineClassRegistrationCallback> &get_engine_class_registration_callbacks() {
+	static std::vector<EngineClassRegistrationCallback> engine_class_registration_callbacks;
+	return engine_class_registration_callbacks;
+}
+
+GDExtensionPropertyInfo *create_c_property_list(const ::godot::List<::godot::PropertyInfo> &plist_cpp, uint32_t *r_size) {
+	GDExtensionPropertyInfo *plist = nullptr;
+	// Linked list size can be expensive to get so we cache it
+	const uint32_t plist_size = plist_cpp.size();
+	if (r_size != nullptr) {
+		*r_size = plist_size;
+	}
+	plist = reinterpret_cast<GDExtensionPropertyInfo *>(memalloc(sizeof(GDExtensionPropertyInfo) * plist_size));
+	unsigned int i = 0;
+	for (const ::godot::PropertyInfo &E : plist_cpp) {
+		plist[i].type = static_cast<GDExtensionVariantType>(E.type);
+		plist[i].name = E.name._native_ptr();
+		plist[i].hint = E.hint;
+		plist[i].hint_string = E.hint_string._native_ptr();
+		plist[i].class_name = E.class_name._native_ptr();
+		plist[i].usage = E.usage;
+		++i;
+	}
+	return plist;
+}
+
+void free_c_property_list(GDExtensionPropertyInfo *plist) {
+	memfree(plist);
+}
+
+void add_engine_class_registration_callback(EngineClassRegistrationCallback p_callback) {
+	get_engine_class_registration_callbacks().push_back(p_callback);
+}
+
+void register_engine_class(const StringName &p_name, const GDExtensionInstanceBindingCallbacks *p_callbacks) {
+	ClassDB::_register_engine_class(p_name, p_callbacks);
+}
+
+void register_engine_classes() {
+	std::vector<EngineClassRegistrationCallback> &engine_class_registration_callbacks = get_engine_class_registration_callbacks();
+	for (EngineClassRegistrationCallback cb : engine_class_registration_callbacks) {
+		cb();
+	}
+	engine_class_registration_callbacks.clear();
+}
+
+} // namespace internal
+
 } // namespace godot

src/core/class_db.cpp

@@ -77,7 +77,7 @@ void ClassDB::add_property(const StringName &p_class, const PropertyInfo &p_pinf
 	if (p_setter != String("")) {
 		setter = get_method(p_class, p_setter);
 
-		ERR_FAIL_COND_MSG(!setter, String("Setter method '{0}::{1}()' not found for property '{2}::{3}'.").format(Array::make(p_class, p_setter, p_class, p_pinfo.name)));
+		ERR_FAIL_NULL_MSG(setter, String("Setter method '{0}::{1}()' not found for property '{2}::{3}'.").format(Array::make(p_class, p_setter, p_class, p_pinfo.name)));
 
 		size_t exp_args = 1 + (p_index >= 0 ? 1 : 0);
 		ERR_FAIL_COND_MSG((int)exp_args != setter->get_argument_count(), String("Setter method '{0}::{1}()' must take a single argument.").format(Array::make(p_class, p_setter)));
@@ -86,7 +86,7 @@ void ClassDB::add_property(const StringName &p_class, const PropertyInfo &p_pinf
 	ERR_FAIL_COND_MSG(p_getter == String(""), String("Getter method must be specified for '{0}::{1}'.").format(Array::make(p_class, p_pinfo.name)));
 
 	MethodBind *getter = get_method(p_class, p_getter);
-	ERR_FAIL_COND_MSG(!getter, String("Getter method '{0}::{1}()' not found for property '{2}::{3}'.").format(Array::make(p_class, p_getter, p_class, p_pinfo.name)));
+	ERR_FAIL_NULL_MSG(getter, String("Getter method '{0}::{1}()' not found for property '{2}::{3}'.").format(Array::make(p_class, p_getter, p_class, p_pinfo.name)));
 	{
 		size_t exp_args = 0 + (p_index >= 0 ? 1 : 0);
 		ERR_FAIL_COND_MSG((int)exp_args != getter->get_argument_count(), String("Getter method '{0}::{1}()' must not take any argument.").format(Array::make(p_class, p_getter)));
@@ -105,15 +105,7 @@ void ClassDB::add_property(const StringName &p_class, const PropertyInfo &p_pinf
 		p_pinfo.usage, // DEFAULT //uint32_t usage;
 	};
 
-	PropertySetGet setget;
-	setget.setter = p_setter;
-	setget.getter = p_getter;
-	setget._setptr = setter;
-	setget._getptr = getter;
-	setget.index = p_index;
-	setget.type = p_pinfo.type;
-
-	internal::gdextension_interface_classdb_register_extension_class_property(internal::library, info.name._native_ptr(), &prop_info, setget.setter._native_ptr(), setget.getter._native_ptr());
+	internal::gdextension_interface_classdb_register_extension_class_property_indexed(internal::library, info.name._native_ptr(), &prop_info, p_setter._native_ptr(), p_getter._native_ptr(), p_index);
 }
 
 MethodBind *ClassDB::get_method(const StringName &p_class, const StringName &p_method) {
@@ -318,7 +310,18 @@ GDExtensionClassCallVirtual ClassDB::get_virtual_func(void *p_userdata, GDExtens
 
 const GDExtensionInstanceBindingCallbacks *ClassDB::get_instance_binding_callbacks(const StringName &p_class) {
 	std::unordered_map<StringName, const GDExtensionInstanceBindingCallbacks *>::iterator callbacks_it = instance_binding_callbacks.find(p_class);
-	ERR_FAIL_COND_V_MSG(callbacks_it == instance_binding_callbacks.end(), nullptr, String("Cannot find instance binding callbacks for class '{0}'.").format(Array::make(p_class)));
+	if (likely(callbacks_it != instance_binding_callbacks.end())) {
+		return callbacks_it->second;
+	}
+
+	// If we don't have an instance binding callback for the given class, find the closest parent where we do.
+	StringName class_name = p_class;
+	do {
+		class_name = get_parent_class(class_name);
+		ERR_FAIL_COND_V_MSG(class_name == StringName(), nullptr, String("Cannot find instance binding callbacks for class '{0}'.").format(Array::make(p_class)));
+		callbacks_it = instance_binding_callbacks.find(class_name);
+	} while (callbacks_it == instance_binding_callbacks.end());
+
 	return callbacks_it->second;
 }
 
@@ -349,6 +352,7 @@ void ClassDB::initialize(GDExtensionInitializationLevel p_level) {
 }
 
 void ClassDB::deinitialize(GDExtensionInitializationLevel p_level) {
+	std::set<StringName> to_erase;
 	for (std::vector<StringName>::reverse_iterator i = class_register_order.rbegin(); i != class_register_order.rend(); ++i) {
 		const StringName &name = *i;
 		const ClassInfo &cl = classes[name];
@@ -359,9 +363,20 @@ void ClassDB::deinitialize(GDExtensionInitializationLevel p_level) {
 
 		internal::gdextension_interface_classdb_unregister_extension_class(internal::library, name._native_ptr());
 
-		for (auto method : cl.method_map) {
+		for (const std::pair<const StringName, MethodBind *> &method : cl.method_map) {
 			memdelete(method.second);
 		}
+
+		classes.erase(name);
+		to_erase.insert(name);
+	}
+
+	{
+		// The following is equivalent to c++20 `std::erase_if(class_register_order, [&](const StringName& name){ return to_erase.contains(name); });`
+		std::vector<StringName>::iterator it = std::remove_if(class_register_order.begin(), class_register_order.end(), [&](const StringName &p_name) {
+			return to_erase.count(p_name) > 0;
+		});
+		class_register_order.erase(it, class_register_order.end());
 	}
 }
 

src/core/memory.cpp

@@ -42,7 +42,7 @@ void *Memory::alloc_static(size_t p_bytes, bool p_pad_align) {
 #endif
 
 	void *mem = internal::gdextension_interface_mem_alloc(p_bytes + (prepad ? PAD_ALIGN : 0));
-	ERR_FAIL_COND_V(!mem, nullptr);
+	ERR_FAIL_NULL_V(mem, nullptr);
 
 	if (prepad) {
 		uint8_t *s8 = (uint8_t *)mem;
@@ -71,7 +71,7 @@ void *Memory::realloc_static(void *p_memory, size_t p_bytes, bool p_pad_align) {
 	if (prepad) {
 		mem -= PAD_ALIGN;
 		mem = (uint8_t *)internal::gdextension_interface_mem_realloc(mem, p_bytes + PAD_ALIGN);
-		ERR_FAIL_COND_V(!mem, nullptr);
+		ERR_FAIL_NULL_V(mem, nullptr);
 		return mem + PAD_ALIGN;
 	} else {
 		return (uint8_t *)internal::gdextension_interface_mem_realloc(mem, p_bytes);
@@ -103,28 +103,29 @@ _GlobalNil _GlobalNilClass::_nil;
 
 } // namespace godot
 
-void *operator new(size_t p_size, const char *p_description) {
+// p_dummy argument is added to avoid conflicts with the engine functions when both engine and GDExtension are built as a static library on iOS.
+void *operator new(size_t p_size, const char *p_dummy, const char *p_description) {
 	return godot::Memory::alloc_static(p_size);
 }
 
-void *operator new(size_t p_size, void *(*p_allocfunc)(size_t p_size)) {
+void *operator new(size_t p_size, const char *p_dummy, void *(*p_allocfunc)(size_t p_size)) {
 	return p_allocfunc(p_size);
 }
 
 using namespace godot;
 
 #ifdef _MSC_VER
-void operator delete(void *p_mem, const char *p_description) {
+void operator delete(void *p_mem, const char *p_dummy, const char *p_description) {
 	ERR_PRINT("Call to placement delete should not happen.");
 	CRASH_NOW();
 }
 
-void operator delete(void *p_mem, void *(*p_allocfunc)(size_t p_size)) {
+void operator delete(void *p_mem, const char *p_dummy, void *(*p_allocfunc)(size_t p_size)) {
 	ERR_PRINT("Call to placement delete should not happen.");
 	CRASH_NOW();
 }
 
-void operator delete(void *p_mem, void *p_pointer, size_t check, const char *p_description) {
+void operator delete(void *p_mem, const char *p_dummy, void *p_pointer, size_t check, const char *p_description) {
 	ERR_PRINT("Call to placement delete should not happen.");
 	CRASH_NOW();
 }

src/godot.cpp

@@ -30,10 +30,11 @@
 
 #include <godot_cpp/godot.hpp>
 
-#include <godot_cpp/classes/editor_plugin.hpp>
+#include <godot_cpp/classes/editor_plugin_registration.hpp>
 #include <godot_cpp/classes/wrapped.hpp>
 #include <godot_cpp/core/class_db.hpp>
 #include <godot_cpp/core/memory.hpp>
+#include <godot_cpp/core/version.hpp>
 #include <godot_cpp/variant/variant.hpp>
 
 #include <godot_cpp/core/error_macros.hpp>
@@ -128,6 +129,8 @@ GDExtensionInterfaceStringOperatorPlusEqChar gdextension_interface_string_operat
 GDExtensionInterfaceStringOperatorPlusEqCstr gdextension_interface_string_operator_plus_eq_cstr = nullptr;
 GDExtensionInterfaceStringOperatorPlusEqWcstr gdextension_interface_string_operator_plus_eq_wcstr = nullptr;
 GDExtensionInterfaceStringOperatorPlusEqC32str gdextension_interface_string_operator_plus_eq_c32str = nullptr;
+GDExtensionInterfaceStringResize gdextension_interface_string_resize = nullptr;
+GDExtensionInterfaceStringNameNewWithLatin1Chars gdextension_interface_string_name_new_with_latin1_chars = nullptr;
 GDExtensionInterfaceXmlParserOpenBuffer gdextension_interface_xml_parser_open_buffer = nullptr;
 GDExtensionInterfaceFileAccessStoreBuffer gdextension_interface_file_access_store_buffer = nullptr;
 GDExtensionInterfaceFileAccessGetBuffer gdextension_interface_file_access_get_buffer = nullptr;
@@ -168,16 +171,21 @@ 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;
+GDExtensionInterfaceCallableCustomGetUserData gdextension_interface_callable_custom_get_userdata = nullptr;
 GDExtensionInterfaceRefGetObject gdextension_interface_ref_get_object = nullptr;
 GDExtensionInterfaceRefSetObject gdextension_interface_ref_set_object = nullptr;
-GDExtensionInterfaceScriptInstanceCreate gdextension_interface_script_instance_create = nullptr;
+GDExtensionInterfaceScriptInstanceCreate2 gdextension_interface_script_instance_create2 = nullptr;
+GDExtensionInterfacePlaceHolderScriptInstanceCreate gdextension_interface_placeholder_script_instance_create = nullptr;
+GDExtensionInterfacePlaceHolderScriptInstanceUpdate gdextension_interface_placeholder_script_instance_update = nullptr;
 GDExtensionInterfaceClassdbConstructObject gdextension_interface_classdb_construct_object = nullptr;
 GDExtensionInterfaceClassdbGetMethodBind gdextension_interface_classdb_get_method_bind = nullptr;
 GDExtensionInterfaceClassdbGetClassTag gdextension_interface_classdb_get_class_tag = nullptr;
-GDExtensionInterfaceClassdbRegisterExtensionClass gdextension_interface_classdb_register_extension_class = nullptr;
+GDExtensionInterfaceClassdbRegisterExtensionClass2 gdextension_interface_classdb_register_extension_class2 = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClassMethod gdextension_interface_classdb_register_extension_class_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;
 GDExtensionInterfaceClassdbRegisterExtensionClassPropertyGroup gdextension_interface_classdb_register_extension_class_property_group = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClassPropertySubgroup gdextension_interface_classdb_register_extension_class_property_subgroup = nullptr;
 GDExtensionInterfaceClassdbRegisterExtensionClassSignal gdextension_interface_classdb_register_extension_class_signal = nullptr;
@@ -188,13 +196,19 @@ GDExtensionInterfaceEditorRemovePlugin gdextension_interface_editor_remove_plugi
 
 } // namespace internal
 
-GDExtensionBinding::Callback GDExtensionBinding::init_callback = nullptr;
-GDExtensionBinding::Callback GDExtensionBinding::terminate_callback = nullptr;
-GDExtensionInitializationLevel GDExtensionBinding::minimum_initialization_level = GDEXTENSION_INITIALIZATION_CORE;
+bool GDExtensionBinding::api_initialized = false;
+int GDExtensionBinding::level_initialized[MODULE_INITIALIZATION_LEVEL_MAX] = { 0 };
+GDExtensionBinding::InitDataList GDExtensionBinding::initdata;
 
-#define LOAD_PROC_ADDRESS(m_name, m_type)                                           \
-	internal::gdextension_interface_##m_name = (m_type)p_get_proc_address(#m_name); \
-	ERR_FAIL_NULL_V_MSG(internal::gdextension_interface_##m_name, false, "Unable to load GDExtension interface function " #m_name "()")
+#define ERR_PRINT_EARLY(m_msg) \
+	internal::gdextension_interface_print_error(m_msg, FUNCTION_STR, __FILE__, __LINE__, false)
+
+#define LOAD_PROC_ADDRESS(m_name, m_type)                                               \
+	internal::gdextension_interface_##m_name = (m_type)p_get_proc_address(#m_name);     \
+	if (!internal::gdextension_interface_##m_name) {                                    \
+		ERR_PRINT_EARLY("Unable to load GDExtension interface function " #m_name "()"); \
+		return false;                                                                   \
+	}
 
 // Partial definition of the legacy interface so we can detect it and show an error.
 typedef struct {
@@ -211,20 +225,34 @@ typedef struct {
 	GDExtensionInterfacePrintErrorWithMessage print_error_with_message;
 } LegacyGDExtensionInterface;
 
-GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_get_proc_address, GDExtensionClassLibraryPtr p_library, GDExtensionInitialization *r_initialization) {
+GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_get_proc_address, GDExtensionClassLibraryPtr p_library, InitData *p_init_data, GDExtensionInitialization *r_initialization) {
+	if (!p_init_data || !p_init_data->init_callback) {
+		ERR_FAIL_V_MSG(false, "Initialization callback must be defined.");
+	}
+
+	if (api_initialized) {
+		r_initialization->initialize = initialize_level;
+		r_initialization->deinitialize = deinitialize_level;
+		r_initialization->userdata = p_init_data;
+		r_initialization->minimum_initialization_level = p_init_data->minimum_initialization_level;
+
+		return true;
+	}
+
 	// Make sure we weren't passed the legacy struct.
 	uint32_t *raw_interface = (uint32_t *)(void *)p_get_proc_address;
 	if (raw_interface[0] == 4 && raw_interface[1] == 0) {
 		// Use the legacy interface only to give a nice error.
 		LegacyGDExtensionInterface *legacy_interface = (LegacyGDExtensionInterface *)p_get_proc_address;
-		internal::gdextension_interface_print_error_with_message = (GDExtensionInterfacePrintErrorWithMessage)legacy_interface->print_error_with_message;
-		ERR_FAIL_V_MSG(false, "Cannot load a GDExtension built for Godot 4.1+ in Godot 4.0.");
+		internal::gdextension_interface_print_error = (GDExtensionInterfacePrintError)legacy_interface->print_error;
+		ERR_PRINT_EARLY("Cannot load a GDExtension built for Godot 4.1+ in Godot 4.0.");
+		return false;
 	}
 
-	// Load the "print_error_with_message" function first (needed by the ERR_FAIL_NULL_V_MSG() macro).
-	internal::gdextension_interface_print_error_with_message = (GDExtensionInterfacePrintErrorWithMessage)p_get_proc_address("print_error_with_message");
-	if (!internal::gdextension_interface_print_error_with_message) {
-		printf("ERROR: Unable to load GDExtension interface function print_error_with_message().\n");
+	// Load the "print_error" function first (needed by the ERR_PRINT_EARLY() macro).
+	internal::gdextension_interface_print_error = (GDExtensionInterfacePrintError)p_get_proc_address("print_error");
+	if (!internal::gdextension_interface_print_error) {
+		printf("ERROR: Unable to load GDExtension interface function print_error().\n");
 		return false;
 	}
 
@@ -233,10 +261,33 @@ GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_ge
 	internal::token = p_library;
 
 	LOAD_PROC_ADDRESS(get_godot_version, GDExtensionInterfaceGetGodotVersion);
+	internal::gdextension_interface_get_godot_version(&internal::godot_version);
+
+	// Check that godot-cpp was compiled using an extension_api.json older or at the
+	// same version as the Godot that is loading it.
+	bool compatible;
+	if (internal::godot_version.major != GODOT_VERSION_MAJOR) {
+		compatible = internal::godot_version.major > GODOT_VERSION_MAJOR;
+	} else if (internal::godot_version.minor != GODOT_VERSION_MINOR) {
+		compatible = internal::godot_version.minor > GODOT_VERSION_MINOR;
+	} else {
+		compatible = internal::godot_version.patch >= GODOT_VERSION_PATCH;
+	}
+	if (!compatible) {
+		// We need to use snprintf() here because vformat() uses Variant, and we haven't loaded
+		// the GDExtension interface far enough to use Variants yet.
+		char msg[128];
+		snprintf(msg, 128, "Cannot load a GDExtension built for Godot %d.%d.%d using an older version of Godot (%d.%d.%d).",
+				GODOT_VERSION_MAJOR, GODOT_VERSION_MINOR, GODOT_VERSION_PATCH,
+				internal::godot_version.major, internal::godot_version.minor, internal::godot_version.patch);
+		ERR_PRINT_EARLY(msg);
+		return false;
+	}
+
 	LOAD_PROC_ADDRESS(mem_alloc, GDExtensionInterfaceMemAlloc);
 	LOAD_PROC_ADDRESS(mem_realloc, GDExtensionInterfaceMemRealloc);
 	LOAD_PROC_ADDRESS(mem_free, GDExtensionInterfaceMemFree);
-	LOAD_PROC_ADDRESS(print_error, GDExtensionInterfacePrintError);
+	LOAD_PROC_ADDRESS(print_error_with_message, GDExtensionInterfacePrintErrorWithMessage);
 	LOAD_PROC_ADDRESS(print_warning, GDExtensionInterfacePrintWarning);
 	LOAD_PROC_ADDRESS(print_warning_with_message, GDExtensionInterfacePrintWarningWithMessage);
 	LOAD_PROC_ADDRESS(print_script_error, GDExtensionInterfacePrintScriptError);
@@ -310,6 +361,8 @@ GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_ge
 	LOAD_PROC_ADDRESS(string_operator_plus_eq_cstr, GDExtensionInterfaceStringOperatorPlusEqCstr);
 	LOAD_PROC_ADDRESS(string_operator_plus_eq_wcstr, GDExtensionInterfaceStringOperatorPlusEqWcstr);
 	LOAD_PROC_ADDRESS(string_operator_plus_eq_c32str, GDExtensionInterfaceStringOperatorPlusEqC32str);
+	LOAD_PROC_ADDRESS(string_resize, GDExtensionInterfaceStringResize);
+	LOAD_PROC_ADDRESS(string_name_new_with_latin1_chars, GDExtensionInterfaceStringNameNewWithLatin1Chars);
 	LOAD_PROC_ADDRESS(xml_parser_open_buffer, GDExtensionInterfaceXmlParserOpenBuffer);
 	LOAD_PROC_ADDRESS(file_access_store_buffer, GDExtensionInterfaceFileAccessStoreBuffer);
 	LOAD_PROC_ADDRESS(file_access_get_buffer, GDExtensionInterfaceFileAccessGetBuffer);
@@ -350,16 +403,21 @@ 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(callable_custom_get_userdata, GDExtensionInterfaceCallableCustomGetUserData);
 	LOAD_PROC_ADDRESS(ref_get_object, GDExtensionInterfaceRefGetObject);
 	LOAD_PROC_ADDRESS(ref_set_object, GDExtensionInterfaceRefSetObject);
-	LOAD_PROC_ADDRESS(script_instance_create, GDExtensionInterfaceScriptInstanceCreate);
+	LOAD_PROC_ADDRESS(script_instance_create2, GDExtensionInterfaceScriptInstanceCreate2);
+	LOAD_PROC_ADDRESS(placeholder_script_instance_create, GDExtensionInterfacePlaceHolderScriptInstanceCreate);
+	LOAD_PROC_ADDRESS(placeholder_script_instance_update, GDExtensionInterfacePlaceHolderScriptInstanceUpdate);
 	LOAD_PROC_ADDRESS(classdb_construct_object, GDExtensionInterfaceClassdbConstructObject);
 	LOAD_PROC_ADDRESS(classdb_get_method_bind, GDExtensionInterfaceClassdbGetMethodBind);
 	LOAD_PROC_ADDRESS(classdb_get_class_tag, GDExtensionInterfaceClassdbGetClassTag);
-	LOAD_PROC_ADDRESS(classdb_register_extension_class, GDExtensionInterfaceClassdbRegisterExtensionClass);
+	LOAD_PROC_ADDRESS(classdb_register_extension_class2, GDExtensionInterfaceClassdbRegisterExtensionClass2);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_method, GDExtensionInterfaceClassdbRegisterExtensionClassMethod);
 	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);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_property_group, GDExtensionInterfaceClassdbRegisterExtensionClassPropertyGroup);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_property_subgroup, GDExtensionInterfaceClassdbRegisterExtensionClassPropertySubgroup);
 	LOAD_PROC_ADDRESS(classdb_register_extension_class_signal, GDExtensionInterfaceClassdbRegisterExtensionClassSignal);
@@ -368,63 +426,98 @@ GDExtensionBool GDExtensionBinding::init(GDExtensionInterfaceGetProcAddress p_ge
 	LOAD_PROC_ADDRESS(editor_add_plugin, GDExtensionInterfaceEditorAddPlugin);
 	LOAD_PROC_ADDRESS(editor_remove_plugin, GDExtensionInterfaceEditorRemovePlugin);
 
-	// Load the Godot version.
-	internal::gdextension_interface_get_godot_version(&internal::godot_version);
-
 	r_initialization->initialize = initialize_level;
 	r_initialization->deinitialize = deinitialize_level;
-	r_initialization->minimum_initialization_level = minimum_initialization_level;
-
-	ERR_FAIL_COND_V_MSG(init_callback == nullptr, false, "Initialization callback must be defined.");
+	r_initialization->userdata = p_init_data;
+	r_initialization->minimum_initialization_level = p_init_data->minimum_initialization_level;
 
 	Variant::init_bindings();
-	register_engine_classes();
+	godot::internal::register_engine_classes();
 
+	api_initialized = true;
 	return true;
 }
 
 #undef LOAD_PROC_ADDRESS
+#undef ERR_PRINT_EARLY
 
-void GDExtensionBinding::initialize_level(void *userdata, GDExtensionInitializationLevel p_level) {
+void GDExtensionBinding::initialize_level(void *p_userdata, GDExtensionInitializationLevel p_level) {
+	ERR_FAIL_COND(static_cast<ModuleInitializationLevel>(p_level) >= MODULE_INITIALIZATION_LEVEL_MAX);
 	ClassDB::current_level = p_level;
 
-	if (init_callback) {
-		init_callback(static_cast<ModuleInitializationLevel>(p_level));
+	InitData *init_data = static_cast<InitData *>(p_userdata);
+	if (init_data && init_data->init_callback) {
+		init_data->init_callback(static_cast<ModuleInitializationLevel>(p_level));
 	}
 
-	ClassDB::initialize(p_level);
+	if (level_initialized[p_level] == 0) {
+		ClassDB::initialize(p_level);
+	}
+	level_initialized[p_level]++;
 }
 
-void GDExtensionBinding::deinitialize_level(void *userdata, GDExtensionInitializationLevel p_level) {
+void GDExtensionBinding::deinitialize_level(void *p_userdata, GDExtensionInitializationLevel p_level) {
+	ERR_FAIL_COND(static_cast<ModuleInitializationLevel>(p_level) >= MODULE_INITIALIZATION_LEVEL_MAX);
 	ClassDB::current_level = p_level;
 
-	if (terminate_callback) {
-		terminate_callback(static_cast<ModuleInitializationLevel>(p_level));
+	InitData *init_data = static_cast<InitData *>(p_userdata);
+	if (init_data && init_data->terminate_callback) {
+		init_data->terminate_callback(static_cast<ModuleInitializationLevel>(p_level));
 	}
 
-	EditorPlugins::deinitialize(p_level);
-	ClassDB::deinitialize(p_level);
+	level_initialized[p_level]--;
+	if (level_initialized[p_level] == 0) {
+		EditorPlugins::deinitialize(p_level);
+		ClassDB::deinitialize(p_level);
+	}
 }
+
+void GDExtensionBinding::InitDataList::add(InitData *p_data) {
+	if (data_count == data_capacity) {
+		void *new_ptr = realloc(data, sizeof(InitData *) * (data_capacity + 32));
+		if (new_ptr) {
+			data = (InitData **)(new_ptr);
+			data_capacity += 32;
+		} else {
+			ERR_FAIL_MSG("Unable to allocate memory for extension callbacks.");
+		}
+	}
+	data[data_count++] = p_data;
+}
+
+GDExtensionBinding::InitDataList::~InitDataList() {
+	for (int i = 0; i < data_count; i++) {
+		if (data[i]) {
+			delete data[i];
+		}
+	}
+	if (data) {
+		free(data);
+	}
+}
+
 GDExtensionBinding::InitObject::InitObject(GDExtensionInterfaceGetProcAddress p_get_proc_address, GDExtensionClassLibraryPtr p_library, GDExtensionInitialization *r_initialization) {
 	get_proc_address = p_get_proc_address;
 	library = p_library;
 	initialization = r_initialization;
+	init_data = new InitData();
+	GDExtensionBinding::initdata.add(init_data);
 }
 
 void GDExtensionBinding::InitObject::register_initializer(Callback p_init) const {
-	GDExtensionBinding::init_callback = p_init;
+	init_data->init_callback = p_init;
 }
 
 void GDExtensionBinding::InitObject::register_terminator(Callback p_terminate) const {
-	GDExtensionBinding::terminate_callback = p_terminate;
+	init_data->terminate_callback = p_terminate;
 }
 
 void GDExtensionBinding::InitObject::set_minimum_library_initialization_level(ModuleInitializationLevel p_level) const {
-	GDExtensionBinding::minimum_initialization_level = static_cast<GDExtensionInitializationLevel>(p_level);
+	init_data->minimum_initialization_level = static_cast<GDExtensionInitializationLevel>(p_level);
 }
 
 GDExtensionBool GDExtensionBinding::InitObject::init() const {
-	return GDExtensionBinding::init(get_proc_address, library, initialization);
+	return GDExtensionBinding::init(get_proc_address, library, init_data, initialization);
 }
 
 } // namespace godot

src/variant/callable_custom.cpp

@@ -0,0 +1,113 @@
+/**************************************************************************/
+/*  callable_custom.cpp                                                   */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#include <godot_cpp/variant/callable_custom.hpp>
+
+#include <godot_cpp/core/object.hpp>
+#include <godot_cpp/variant/callable.hpp>
+
+namespace godot {
+
+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);
+}
+
+static GDExtensionBool callable_custom_is_valid(void *p_userdata) {
+	CallableCustom *callable_custom = (CallableCustom *)p_userdata;
+	return callable_custom->is_valid();
+}
+
+static void callable_custom_free(void *p_userdata) {
+	CallableCustom *callable_custom = (CallableCustom *)p_userdata;
+	memdelete(callable_custom);
+}
+
+static uint32_t callable_custom_hash(void *p_userdata) {
+	CallableCustom *callable_custom = (CallableCustom *)p_userdata;
+	return callable_custom->hash();
+}
+
+static void callable_custom_to_string(void *p_userdata, GDExtensionBool *r_is_valid, GDExtensionStringPtr r_out) {
+	CallableCustom *callable_custom = (CallableCustom *)p_userdata;
+	*((String *)r_out) = callable_custom->get_as_text();
+	*r_is_valid = true;
+}
+
+static GDExtensionBool callable_custom_equal_func(void *p_a, void *p_b) {
+	CallableCustom *a = (CallableCustom *)p_a;
+	CallableCustom *b = (CallableCustom *)p_b;
+	CallableCustom::CompareEqualFunc func_a = a->get_compare_equal_func();
+	CallableCustom::CompareEqualFunc func_b = b->get_compare_equal_func();
+	if (func_a != func_b) {
+		return false;
+	}
+	return func_a(a, b);
+}
+
+static GDExtensionBool callable_custom_less_than_func(void *p_a, void *p_b) {
+	CallableCustom *a = (CallableCustom *)p_a;
+	CallableCustom *b = (CallableCustom *)p_b;
+	CallableCustom::CompareEqualFunc func_a = a->get_compare_less_func();
+	CallableCustom::CompareEqualFunc func_b = b->get_compare_less_func();
+	if (func_a != func_b) {
+		// Just compare the addresses.
+		return p_a < p_b;
+	}
+	return func_a(a, b);
+}
+
+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 = {};
+	info.callable_userdata = p_callable_custom;
+	info.token = internal::token;
+	info.object_id = p_callable_custom->get_object();
+	info.call_func = &callable_custom_call;
+	info.is_valid_func = &callable_custom_is_valid;
+	info.free_func = &callable_custom_free;
+	info.hash_func = &callable_custom_hash;
+	info.equal_func = &callable_custom_equal_func;
+	info.less_than_func = &callable_custom_less_than_func;
+	info.to_string_func = &callable_custom_to_string;
+
+	::godot::internal::gdextension_interface_callable_custom_create(_native_ptr(), &info);
+}
+
+CallableCustom *Callable::get_custom() const {
+	CallableCustomBase *callable_custom = (CallableCustomBase *)::godot::internal::gdextension_interface_callable_custom_get_userdata(_native_ptr(), internal::token);
+	return dynamic_cast<CallableCustom *>(callable_custom);
+}
+
+} // namespace godot

src/variant/callable_method_pointer.cpp

@@ -0,0 +1,114 @@
+/**************************************************************************/
+/*  callable_method_pointer.cpp                                           */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#include <godot_cpp/variant/callable_method_pointer.hpp>
+
+#include <godot_cpp/templates/hashfuncs.hpp>
+
+namespace godot {
+
+static void custom_callable_mp_call(void *p_userdata, const GDExtensionConstVariantPtr *p_args, GDExtensionInt p_argument_count, GDExtensionVariantPtr r_return, GDExtensionCallError *r_error) {
+	CallableCustomMethodPointerBase *callable_method_pointer = (CallableCustomMethodPointerBase *)p_userdata;
+	callable_method_pointer->call((const Variant **)p_args, p_argument_count, *(Variant *)r_return, *r_error);
+}
+
+static GDExtensionBool custom_callable_mp_is_valid(void *p_userdata) {
+	CallableCustomMethodPointerBase *callable_method_pointer = (CallableCustomMethodPointerBase *)p_userdata;
+	ObjectID object = callable_method_pointer->get_object();
+	return object == ObjectID() || ObjectDB::get_instance(object);
+}
+
+static void custom_callable_mp_free(void *p_userdata) {
+	CallableCustomMethodPointerBase *callable_method_pointer = (CallableCustomMethodPointerBase *)p_userdata;
+	memdelete(callable_method_pointer);
+}
+
+static uint32_t custom_callable_mp_hash(void *p_userdata) {
+	CallableCustomMethodPointerBase *callable_method_pointer = (CallableCustomMethodPointerBase *)p_userdata;
+	return callable_method_pointer->get_hash();
+}
+
+static GDExtensionBool custom_callable_mp_equal_func(void *p_a, void *p_b) {
+	CallableCustomMethodPointerBase *a = (CallableCustomMethodPointerBase *)p_a;
+	CallableCustomMethodPointerBase *b = (CallableCustomMethodPointerBase *)p_b;
+
+	if (a->get_comp_size() != b->get_comp_size()) {
+		return false;
+	}
+
+	return memcmp(a->get_comp_ptr(), b->get_comp_ptr(), a->get_comp_size() * 4) == 0;
+}
+
+static GDExtensionBool custom_callable_mp_less_than_func(void *p_a, void *p_b) {
+	CallableCustomMethodPointerBase *a = (CallableCustomMethodPointerBase *)p_a;
+	CallableCustomMethodPointerBase *b = (CallableCustomMethodPointerBase *)p_b;
+
+	if (a->get_comp_size() != b->get_comp_size()) {
+		return a->get_comp_size() < b->get_comp_size();
+	}
+
+	return memcmp(a->get_comp_ptr(), b->get_comp_ptr(), a->get_comp_size() * 4) < 0;
+}
+
+void CallableCustomMethodPointerBase::_setup(uint32_t *p_base_ptr, uint32_t p_ptr_size) {
+	comp_ptr = p_base_ptr;
+	comp_size = p_ptr_size / 4;
+
+	for (uint32_t i = 0; i < comp_size; i++) {
+		if (i == 0) {
+			h = hash_murmur3_one_32(comp_ptr[i]);
+		} else {
+			h = hash_murmur3_one_32(comp_ptr[i], h);
+		}
+	}
+}
+
+namespace internal {
+
+Callable create_callable_from_ccmp(CallableCustomMethodPointerBase *p_callable_method_pointer) {
+	GDExtensionCallableCustomInfo info = {};
+	info.callable_userdata = p_callable_method_pointer;
+	info.token = internal::token;
+	info.object_id = p_callable_method_pointer->get_object();
+	info.call_func = &custom_callable_mp_call;
+	info.is_valid_func = &custom_callable_mp_is_valid;
+	info.free_func = &custom_callable_mp_free;
+	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;
+
+	Callable callable;
+	::godot::internal::gdextension_interface_callable_custom_create(callable._native_ptr(), &info);
+	return callable;
+}
+
+} // namespace internal
+
+} // namespace godot

src/variant/char_string.cpp

@@ -38,117 +38,121 @@
 #include <godot_cpp/godot.hpp>
 
 #include <cmath>
+#include <string>
 
 namespace godot {
 
-int CharString::length() const {
-	return _length;
-}
+template <typename L, typename R>
+_FORCE_INLINE_ bool is_str_less(const L *l_ptr, const R *r_ptr) {
+	while (true) {
+		const char32_t l = *l_ptr;
+		const char32_t r = *r_ptr;
 
-const char *CharString::get_data() const {
-	return _data;
-}
+		if (l == 0 && r == 0) {
+			return false;
+		} else if (l == 0) {
+			return true;
+		} else if (r == 0) {
+			return false;
+		} else if (l < r) {
+			return true;
+		} else if (l > r) {
+			return false;
+		}
 
-CharString::CharString(CharString &&p_str) {
-	SWAP(_length, p_str._length);
-	SWAP(_data, p_str._data);
-}
-
-void CharString::operator=(CharString &&p_str) {
-	SWAP(_length, p_str._length);
-	SWAP(_data, p_str._data);
-}
-
-CharString::CharString(const char *str, int length) :
-		_data(str), _length(length) {}
-
-CharString::~CharString() {
-	if (_data != nullptr) {
-		memdelete_arr(_data);
+		l_ptr++;
+		r_ptr++;
 	}
 }
 
-int Char16String::length() const {
-	return _length;
+template <class T>
+bool CharStringT<T>::operator<(const CharStringT<T> &p_right) const {
+	if (length() == 0) {
+		return p_right.length() != 0;
+	}
+
+	return is_str_less(get_data(), p_right.get_data());
 }
 
-const char16_t *Char16String::get_data() const {
-	return _data;
+template <class T>
+CharStringT<T> &CharStringT<T>::operator+=(T p_char) {
+	const int lhs_len = length();
+	resize(lhs_len + 2);
+
+	T *dst = ptrw();
+	dst[lhs_len] = p_char;
+	dst[lhs_len + 1] = 0;
+
+	return *this;
 }
 
-Char16String::Char16String(Char16String &&p_str) {
-	SWAP(_length, p_str._length);
-	SWAP(_data, p_str._data);
+template <class T>
+void CharStringT<T>::operator=(const T *p_cstr) {
+	copy_from(p_cstr);
 }
 
-void Char16String::operator=(Char16String &&p_str) {
-	SWAP(_length, p_str._length);
-	SWAP(_data, p_str._data);
-}
-
-Char16String::Char16String(const char16_t *str, int length) :
-		_data(str), _length(length) {}
-
-Char16String::~Char16String() {
-	if (_data != nullptr) {
-		memdelete_arr(_data);
+template <>
+const char *CharStringT<char>::get_data() const {
+	if (size()) {
+		return &operator[](0);
+	} else {
+		return "";
 	}
 }
 
-int Char32String::length() const {
-	return _length;
-}
-
-const char32_t *Char32String::get_data() const {
-	return _data;
-}
-
-Char32String::Char32String(Char32String &&p_str) {
-	SWAP(_length, p_str._length);
-	SWAP(_data, p_str._data);
-}
-
-void Char32String::operator=(Char32String &&p_str) {
-	SWAP(_length, p_str._length);
-	SWAP(_data, p_str._data);
-}
-
-Char32String::Char32String(const char32_t *str, int length) :
-		_data(str), _length(length) {}
-
-Char32String::~Char32String() {
-	if (_data != nullptr) {
-		memdelete_arr(_data);
+template <>
+const char16_t *CharStringT<char16_t>::get_data() const {
+	if (size()) {
+		return &operator[](0);
+	} else {
+		return u"";
 	}
 }
 
-int CharWideString::length() const {
-	return _length;
-}
-
-const wchar_t *CharWideString::get_data() const {
-	return _data;
-}
-
-CharWideString::CharWideString(CharWideString &&p_str) {
-	SWAP(_length, p_str._length);
-	SWAP(_data, p_str._data);
-}
-
-void CharWideString::operator=(CharWideString &&p_str) {
-	SWAP(_length, p_str._length);
-	SWAP(_data, p_str._data);
-}
-
-CharWideString::CharWideString(const wchar_t *str, int length) :
-		_data(str), _length(length) {}
-
-CharWideString::~CharWideString() {
-	if (_data != nullptr) {
-		memdelete_arr(_data);
+template <>
+const char32_t *CharStringT<char32_t>::get_data() const {
+	if (size()) {
+		return &operator[](0);
+	} else {
+		return U"";
 	}
 }
 
+template <>
+const wchar_t *CharStringT<wchar_t>::get_data() const {
+	if (size()) {
+		return &operator[](0);
+	} else {
+		return L"";
+	}
+}
+
+template <class T>
+void CharStringT<T>::copy_from(const T *p_cstr) {
+	if (!p_cstr) {
+		resize(0);
+		return;
+	}
+
+	size_t len = std::char_traits<T>::length(p_cstr);
+
+	if (len == 0) {
+		resize(0);
+		return;
+	}
+
+	Error err = resize(++len); // include terminating null char
+
+	ERR_FAIL_COND_MSG(err != OK, "Failed to copy C-string.");
+
+	memcpy(ptrw(), p_cstr, len);
+}
+
+template class CharStringT<char>;
+template class CharStringT<char16_t>;
+template class CharStringT<char32_t>;
+template class CharStringT<wchar_t>;
+
 // Custom String functions that are not part of bound API.
 // It's easier to have them written in C++ directly than in a Python script that generates them.
 
@@ -228,56 +232,65 @@ String rtoss(double p_val) {
 CharString String::utf8() const {
 	int length = internal::gdextension_interface_string_to_utf8_chars(_native_ptr(), nullptr, 0);
 	int size = length + 1;
-	char *cstr = memnew_arr(char, size);
-	internal::gdextension_interface_string_to_utf8_chars(_native_ptr(), cstr, length);
+	CharString str;
+	str.resize(size);
+	internal::gdextension_interface_string_to_utf8_chars(_native_ptr(), str.ptrw(), length);
 
-	cstr[length] = '\0';
+	str[length] = '\0';
 
-	return CharString(cstr, length);
+	return str;
 }
 
 CharString String::ascii() const {
 	int length = internal::gdextension_interface_string_to_latin1_chars(_native_ptr(), nullptr, 0);
 	int size = length + 1;
-	char *cstr = memnew_arr(char, size);
-	internal::gdextension_interface_string_to_latin1_chars(_native_ptr(), cstr, length);
+	CharString str;
+	str.resize(size);
+	internal::gdextension_interface_string_to_latin1_chars(_native_ptr(), str.ptrw(), length);
 
-	cstr[length] = '\0';
+	str[length] = '\0';
 
-	return CharString(cstr, length);
+	return str;
 }
 
 Char16String String::utf16() const {
 	int length = internal::gdextension_interface_string_to_utf16_chars(_native_ptr(), nullptr, 0);
 	int size = length + 1;
-	char16_t *cstr = memnew_arr(char16_t, size);
-	internal::gdextension_interface_string_to_utf16_chars(_native_ptr(), cstr, length);
+	Char16String str;
+	str.resize(size);
+	internal::gdextension_interface_string_to_utf16_chars(_native_ptr(), str.ptrw(), length);
 
-	cstr[length] = '\0';
+	str[length] = '\0';
 
-	return Char16String(cstr, length);
+	return str;
 }
 
 Char32String String::utf32() const {
 	int length = internal::gdextension_interface_string_to_utf32_chars(_native_ptr(), nullptr, 0);
 	int size = length + 1;
-	char32_t *cstr = memnew_arr(char32_t, size);
-	internal::gdextension_interface_string_to_utf32_chars(_native_ptr(), cstr, length);
+	Char32String str;
+	str.resize(size);
+	internal::gdextension_interface_string_to_utf32_chars(_native_ptr(), str.ptrw(), length);
 
-	cstr[length] = '\0';
+	str[length] = '\0';
 
-	return Char32String(cstr, length);
+	return str;
 }
 
 CharWideString String::wide_string() const {
 	int length = internal::gdextension_interface_string_to_wide_chars(_native_ptr(), nullptr, 0);
 	int size = length + 1;
-	wchar_t *cstr = memnew_arr(wchar_t, size);
-	internal::gdextension_interface_string_to_wide_chars(_native_ptr(), cstr, length);
+	CharWideString str;
+	str.resize(size);
+	internal::gdextension_interface_string_to_wide_chars(_native_ptr(), str.ptrw(), length);
 
-	cstr[length] = '\0';
+	str[length] = '\0';
 
-	return CharWideString(cstr, length);
+	return str;
+}
+
+Error String::resize(int p_size) {
+	return (Error)internal::gdextension_interface_string_resize(_native_ptr(), p_size);
 }
 
 String &String::operator=(const char *p_str) {
@@ -445,8 +458,9 @@ String operator+(char32_t p_char, const String &p_str) {
 	return String::chr(p_char) + p_str;
 }
 
-StringName::StringName(const char *from) :
-		StringName(String(from)) {}
+StringName::StringName(const char *from, bool p_static) {
+	internal::gdextension_interface_string_name_new_with_latin1_chars(&opaque, from, p_static);
+}
 
 StringName::StringName(const wchar_t *from) :
 		StringName(String(from)) {}

src/variant/variant.cpp

@@ -268,6 +268,14 @@ Variant::operator int32_t() const {
 	return static_cast<int32_t>(operator int64_t());
 }
 
+Variant::operator int16_t() const {
+	return static_cast<int16_t>(operator int64_t());
+}
+
+Variant::operator int8_t() const {
+	return static_cast<int8_t>(operator int64_t());
+}
+
 Variant::operator uint64_t() const {
 	return static_cast<uint64_t>(operator int64_t());
 }
@@ -276,6 +284,14 @@ Variant::operator uint32_t() const {
 	return static_cast<uint32_t>(operator int64_t());
 }
 
+Variant::operator uint16_t() const {
+	return static_cast<uint16_t>(operator int64_t());
+}
+
+Variant::operator uint8_t() const {
+	return static_cast<uint8_t>(operator int64_t());
+}
+
 Variant::operator double() const {
 	double result;
 	to_type_constructor[FLOAT](&result, _native_ptr());
@@ -549,11 +565,11 @@ bool Variant::operator<(const Variant &other) const {
 	return result.operator bool();
 }
 
-void Variant::call(const StringName &method, const Variant **args, int argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+void Variant::callp(const StringName &method, const Variant **args, int argcount, Variant &r_ret, GDExtensionCallError &r_error) {
 	internal::gdextension_interface_variant_call(_native_ptr(), method._native_ptr(), reinterpret_cast<GDExtensionConstVariantPtr *>(args), argcount, r_ret._native_ptr(), &r_error);
 }
 
-void Variant::call_static(Variant::Type type, const StringName &method, const Variant **args, int argcount, Variant &r_ret, GDExtensionCallError &r_error) {
+void Variant::callp_static(Variant::Type type, const StringName &method, const Variant **args, int argcount, Variant &r_ret, GDExtensionCallError &r_error) {
 	internal::gdextension_interface_variant_call_static(static_cast<GDExtensionVariantType>(type), method._native_ptr(), reinterpret_cast<GDExtensionConstVariantPtr *>(args), argcount, r_ret._native_ptr(), &r_error);
 }
 
@@ -638,14 +654,16 @@ bool Variant::in(const Variant &index, bool *r_valid) const {
 
 bool Variant::iter_init(Variant &r_iter, bool &r_valid) const {
 	GDExtensionBool valid;
-	internal::gdextension_interface_variant_iter_init(_native_ptr(), r_iter._native_ptr(), &valid);
-	return PtrToArg<bool>::convert(&valid);
+	GDExtensionBool result = internal::gdextension_interface_variant_iter_init(_native_ptr(), r_iter._native_ptr(), &valid);
+	r_valid = PtrToArg<bool>::convert(&valid);
+	return PtrToArg<bool>::convert(&result);
 }
 
 bool Variant::iter_next(Variant &r_iter, bool &r_valid) const {
 	GDExtensionBool valid;
-	internal::gdextension_interface_variant_iter_next(_native_ptr(), r_iter._native_ptr(), &valid);
-	return PtrToArg<bool>::convert(&valid);
+	GDExtensionBool result = internal::gdextension_interface_variant_iter_next(_native_ptr(), r_iter._native_ptr(), &valid);
+	r_valid = PtrToArg<bool>::convert(&valid);
+	return PtrToArg<bool>::convert(&result);
 }
 
 Variant Variant::iter_get(const Variant &r_iter, bool &r_valid) const {

test/CMakeLists.txt

@@ -36,7 +36,7 @@ set(GODOT_LINKER_FLAGS )
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
 	# using Visual Studio C++
-	set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /EHsc /WX") # /GF /MP
+	set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /WX") # /GF /MP
 	set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /DTYPED_METHOD_BIND")
 
 	if(CMAKE_BUILD_TYPE MATCHES Debug)
@@ -92,6 +92,21 @@ else()
 	endif(CMAKE_BUILD_TYPE MATCHES Debug)
 endif()
 
+# Disable exception handling. Godot doesn't use exceptions anywhere, and this
+# saves around 20% of binary size and very significant build time (GH-80513).
+option(GODOT_DISABLE_EXCEPTIONS ON "Force disabling exception handling code")
+if (GODOT_DISABLE_EXCEPTIONS)
+	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -D_HAS_EXCEPTIONS=0")
+	else()
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} -fno-exceptions")
+	endif()
+else()
+	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+		set(GODOT_COMPILE_FLAGS "${GODOT_COMPILE_FLAGS} /EHsc")
+	endif()
+endif()
+
 # Get Sources
 file(GLOB_RECURSE SOURCES src/*.c**)
 file(GLOB_RECURSE HEADERS include/*.h**)

test/SConstruct

@@ -23,6 +23,17 @@ if env["platform"] == "macos":
         ),
         source=sources,
     )
+elif env["platform"] == "ios":
+    if env["ios_simulator"]:
+        library = env.StaticLibrary(
+            "project/bin/libgdexample.{}.{}.simulator.a".format(env["platform"], env["target"]),
+            source=sources,
+        )
+    else:
+        library = env.StaticLibrary(
+            "project/bin/libgdexample.{}.{}.a".format(env["platform"], env["target"]),
+            source=sources,
+        )
 else:
     library = env.SharedLibrary(
         "project/bin/libgdexample{}{}".format(env["suffix"], env["SHLIBSUFFIX"]),

test/generate_xcframework.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+scons arch=universal ios_simulator=yes platform=ios target=$1 $2
+scons arch=arm64 ios_simulator=no platform=ios target=$1 $2
+
+xcodebuild -create-xcframework -library ./project/bin/libgdexample.ios.$1.a -library ./project/bin/libgdexample.ios.$1.simulator.a -output ./project/bin/libgdexample.ios.$1.xcframework
+xcodebuild -create-xcframework -library ../bin/libgodot-cpp.ios.$1.arm64.a -library ../bin/libgodot-cpp.ios.$1.universal.simulator.a  -output ./project/bin/libgodot-cpp.ios.$1.xcframework

test/project/example.gdextension

@@ -1,7 +1,7 @@
 [configuration]
 
 entry_symbol = "example_library_init"
-compatibility_minimum = 4.1
+compatibility_minimum = "4.1"
 
 [libraries]
 
@@ -11,8 +11,14 @@ windows.debug.x86_32 = "res://bin/libgdexample.windows.template_debug.x86_32.dll
 windows.release.x86_32 = "res://bin/libgdexample.windows.template_release.x86_32.dll"
 windows.debug.x86_64 = "res://bin/libgdexample.windows.template_debug.x86_64.dll"
 windows.release.x86_64 = "res://bin/libgdexample.windows.template_release.x86_64.dll"
+windows.debug.arm64 = "res://bin/libgdexample.windows.template_debug.arm64.dll"
+windows.release.arm64 = "res://bin/libgdexample.windows.template_release.arm64.dll"
+linux.debug.x86_32 = "res://bin/libgdexample.linux.template_debug.x86_32.so"
+linux.release.x86_32 = "res://bin/libgdexample.linux.template_release.x86_32.so"
 linux.debug.x86_64 = "res://bin/libgdexample.linux.template_debug.x86_64.so"
 linux.release.x86_64 = "res://bin/libgdexample.linux.template_release.x86_64.so"
+linux.debug.arm32 = "res://bin/libgdexample.linux.template_debug.arm32.so"
+linux.release.arm32 = "res://bin/libgdexample.linux.template_release.arm32.so"
 linux.debug.arm64 = "res://bin/libgdexample.linux.template_debug.arm64.so"
 linux.release.arm64 = "res://bin/libgdexample.linux.template_release.arm64.so"
 linux.debug.rv64 = "res://bin/libgdexample.linux.template_debug.rv64.so"
@@ -21,3 +27,15 @@ android.debug.x86_64 = "res://bin/libgdexample.android.template_debug.x86_64.so"
 android.release.x86_64 = "res://bin/libgdexample.android.template_release.x86_64.so"
 android.debug.arm64 = "res://bin/libgdexample.android.template_debug.arm64.so"
 android.release.arm64 = "res://bin/libgdexample.android.template_release.arm64.so"
+ios.debug = "res://bin/libgdexample.ios.template_debug.xcframework"
+ios.release = "res://bin/libgdexample.ios.template_release.xcframework"
+web.debug.wasm32 = "res://bin/libgdexample.web.template_debug.wasm32.wasm"
+web.release.wasm32 = "res://bin/libgdexample.web.template_release.wasm32.wasm"
+
+[dependencies]
+ios.debug = {
+  "res://bin/libgodot-cpp.ios.template_debug.xcframework": ""
+}
+ios.release = {
+  "res://bin/libgodot-cpp.ios.template_release.xcframework": ""
+}

test/project/main.gd

@@ -2,6 +2,9 @@ extends "res://test_base.gd"
 
 var custom_signal_emitted = null
 
+class TestClass:
+	func test(p_msg: String) -> String:
+		return p_msg + " world"
 
 func _ready():
 	var example: Example = $Example
@@ -23,6 +26,10 @@ func _ready():
 	# Property list.
 	example.property_from_list = Vector3(100, 200, 300)
 	assert_equal(example.property_from_list, Vector3(100, 200, 300))
+	var prop_list = example.get_property_list()
+	for prop_info in prop_list:
+		if prop_info['name'] == 'mouse_filter':
+			assert_equal(prop_info['usage'], PROPERTY_USAGE_NO_EDITOR)
 
 	# Call simple methods.
 	example.simple_func()
@@ -76,12 +83,75 @@ func _ready():
 	var array: Array[int] = [1, 2, 3]
 	assert_equal(example.test_tarray_arg(array), 6)
 
+	example.callable_bind()
+	assert_equal(custom_signal_emitted, ["bound", 11])
+
 	# String += operator
 	assert_equal(example.test_string_ops(), "ABCĎE")
 
 	# UtilityFunctions::str()
 	assert_equal(example.test_str_utility(), "Hello, World! The answer is 42")
 
+	# Test converting string to char* and doing comparison.
+	assert_equal(example.test_string_is_fourty_two("blah"), false)
+	assert_equal(example.test_string_is_fourty_two("fourty two"), true)
+
+	# String::resize().
+	assert_equal(example.test_string_resize("What"), "What!?")
+
+	# mp_callable() with void method.
+	var mp_callable: Callable = example.test_callable_mp()
+	assert_equal(mp_callable.is_valid(), true)
+	mp_callable.call(example, "void", 36)
+	assert_equal(custom_signal_emitted, ["unbound_method1: Example - void", 36])
+
+	# Check that it works with is_connected().
+	assert_equal(example.renamed.is_connected(mp_callable), false)
+	example.renamed.connect(mp_callable)
+	assert_equal(example.renamed.is_connected(mp_callable), true)
+	# Make sure a new object is still treated as equivalent.
+	assert_equal(example.renamed.is_connected(example.test_callable_mp()), true)
+	assert_equal(mp_callable.hash(), example.test_callable_mp().hash())
+	example.renamed.disconnect(mp_callable)
+	assert_equal(example.renamed.is_connected(mp_callable), false)
+
+	# mp_callable() with return value.
+	var mp_callable_ret: Callable = example.test_callable_mp_ret()
+	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.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()
+	mp_callable_static.call(example, "static", 83)
+	assert_equal(custom_signal_emitted, ["unbound_static_method1: Example - static", 83])
+
+	# Check that it works with is_connected().
+	assert_equal(example.renamed.is_connected(mp_callable_static), false)
+	example.renamed.connect(mp_callable_static)
+	assert_equal(example.renamed.is_connected(mp_callable_static), true)
+	# Make sure a new object is still treated as equivalent.
+	assert_equal(example.renamed.is_connected(example.test_callable_mp_static()), true)
+	assert_equal(mp_callable_static.hash(), example.test_callable_mp_static().hash())
+	example.renamed.disconnect(mp_callable_static)
+	assert_equal(example.renamed.is_connected(mp_callable_static), false)
+
+	# mp_callable_static() with return value.
+	var mp_callable_static_ret: Callable = example.test_callable_mp_static_ret()
+	assert_equal(mp_callable_static_ret.call(example, "static-ret", 84), "unbound_static_method2: Example - static-ret - 84")
+
+	# CallableCustom.
+	var custom_callable: Callable = example.test_custom_callable();
+	assert_equal(custom_callable.is_custom(), true);
+	assert_equal(custom_callable.is_valid(), true);
+	assert_equal(custom_callable.call(), "Hi")
+	assert_equal(custom_callable.hash(), 27);
+	assert_equal(custom_callable.get_object(), null);
+	assert_equal(custom_callable.get_method(), "");
+	assert_equal(str(custom_callable), "<MyCallableCustom>");
+
 	# PackedArray iterators
 	assert_equal(example.test_vector_ops(), 105)
 
@@ -90,6 +160,53 @@ func _ready():
 	example.group_subgroup_custom_position = Vector2(50, 50)
 	assert_equal(example.group_subgroup_custom_position, Vector2(50, 50))
 
+	# Test Object::cast_to<>() and that correct wrappers are being used.
+	var control = Control.new()
+	var sprite = Sprite2D.new()
+	var example_ref = ExampleRef.new()
+
+	assert_equal(example.test_object_cast_to_node(control), true)
+	assert_equal(example.test_object_cast_to_control(control), true)
+	assert_equal(example.test_object_cast_to_example(control), false)
+
+	assert_equal(example.test_object_cast_to_node(example), true)
+	assert_equal(example.test_object_cast_to_control(example), true)
+	assert_equal(example.test_object_cast_to_example(example), true)
+
+	assert_equal(example.test_object_cast_to_node(sprite), true)
+	assert_equal(example.test_object_cast_to_control(sprite), false)
+	assert_equal(example.test_object_cast_to_example(sprite), false)
+
+	assert_equal(example.test_object_cast_to_node(example_ref), false)
+	assert_equal(example.test_object_cast_to_control(example_ref), false)
+	assert_equal(example.test_object_cast_to_example(example_ref), false)
+
+	control.queue_free()
+	sprite.queue_free()
+
+	# Test conversions to and from Variant.
+	assert_equal(example.test_variant_vector2i_conversion(Vector2i(1, 1)), Vector2i(1, 1))
+	assert_equal(example.test_variant_vector2i_conversion(Vector2(1.0, 1.0)), Vector2i(1, 1))
+	assert_equal(example.test_variant_int_conversion(10), 10)
+	assert_equal(example.test_variant_int_conversion(10.0), 10)
+	assert_equal(example.test_variant_float_conversion(10.0), 10.0)
+	assert_equal(example.test_variant_float_conversion(10), 10.0)
+
+	# Test that ptrcalls from GDExtension to the engine are correctly encoding Object and RefCounted.
+	var new_node = Node.new()
+	example.test_add_child(new_node)
+	assert_equal(new_node.get_parent(), example)
+
+	var new_tileset = TileSet.new()
+	var new_tilemap = TileMap.new()
+	example.test_set_tileset(new_tilemap, new_tileset)
+	assert_equal(new_tilemap.tile_set, new_tileset)
+	new_tilemap.queue_free()
+
+	# Test variant call.
+	var test_obj = TestClass.new()
+	assert_equal(example.test_variant_call(test_obj), "hello world")
+
 	# Constants.
 	assert_equal(Example.FIRST, 0)
 	assert_equal(Example.ANSWER_TO_EVERYTHING, 42)
@@ -101,6 +218,10 @@ func _ready():
 	assert_equal(example.test_bitfield(0), 0)
 	assert_equal(example.test_bitfield(Example.FLAG_ONE | Example.FLAG_TWO), 3)
 
+	# Test variant iterator.
+	assert_equal(example.test_variant_iterator([10, 20, 30]), [15, 25, 35])
+	assert_equal(example.test_variant_iterator(null), "iter_init: not valid")
+
 	# RPCs.
 	assert_equal(example.return_last_rpc_arg(), 0)
 	example.test_rpc(42)
@@ -115,6 +236,11 @@ func _ready():
 	get_viewport().push_input(event)
 	assert_equal(custom_signal_emitted, ["_input: H", 72])
 
+	# Check NOTIFICATION_POST_INITIALIZED, both when created from GDScript and godot-cpp.
+	var new_example_ref = ExampleRef.new()
+	assert_equal(new_example_ref.was_post_initialized(), true)
+	assert_equal(example.test_post_initialize(), true)
+
 	exit_with_status()
 
 func _on_Example_custom_signal(signal_name, value):

test/project/project.godot

@@ -12,7 +12,7 @@ config_version=5
 
 config/name="GDExtension Test Project"
 run/main_scene="res://main.tscn"
-config/features=PackedStringArray("4.1")
+config/features=PackedStringArray("4.2")
 config/icon="res://icon.png"
 
 [native_extensions]
@@ -21,4 +21,5 @@ paths=["res://example.gdextension"]
 
 [rendering]
 
+textures/vram_compression/import_etc2_astc=true
 environment/defaults/default_environment="res://default_env.tres"

test/src/example.cpp

@@ -15,6 +15,46 @@
 
 using namespace godot;
 
+class MyCallableCustom : public CallableCustom {
+public:
+	virtual uint32_t hash() const {
+		return 27;
+	}
+
+	virtual String get_as_text() const {
+		return "<MyCallableCustom>";
+	}
+
+	static bool compare_equal_func(const CallableCustom *p_a, const CallableCustom *p_b) {
+		return p_a == p_b;
+	}
+
+	virtual CompareEqualFunc get_compare_equal_func() const {
+		return &MyCallableCustom::compare_equal_func;
+	}
+
+	static bool compare_less_func(const CallableCustom *p_a, const CallableCustom *p_b) {
+		return (void *)p_a < (void *)p_b;
+	}
+
+	virtual CompareLessFunc get_compare_less_func() const {
+		return &MyCallableCustom::compare_less_func;
+	}
+
+	bool is_valid() const {
+		return true;
+	}
+
+	virtual ObjectID get_object() const {
+		return ObjectID();
+	}
+
+	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;
+	}
+};
+
 void ExampleRef::set_id(int p_id) {
 	id = p_id;
 }
@@ -23,10 +63,18 @@ int ExampleRef::get_id() const {
 	return id;
 }
 
+void ExampleRef::_notification(int p_what) {
+	if (p_what == NOTIFICATION_POSTINITIALIZE) {
+		post_initialized = true;
+	}
+}
+
 void ExampleRef::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_id", "id"), &ExampleRef::set_id);
 	ClassDB::bind_method(D_METHOD("get_id"), &ExampleRef::get_id);
 
+	ClassDB::bind_method(D_METHOD("was_post_initialized"), &ExampleRef::was_post_initialized);
+
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "id"), "set_id", "get_id");
 }
 
@@ -117,6 +165,14 @@ bool Example::_property_get_revert(const StringName &p_name, Variant &r_property
 	}
 };
 
+void Example::_validate_property(PropertyInfo &p_property) const {
+	String name = p_property.name;
+	// Test hiding the "mouse_filter" property from the editor.
+	if (name == "mouse_filter") {
+		p_property.usage = PROPERTY_USAGE_NO_EDITOR;
+	}
+}
+
 void Example::_bind_methods() {
 	// Methods.
 	ClassDB::bind_method(D_METHOD("simple_func"), &Example::simple_func);
@@ -138,15 +194,41 @@ void Example::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("test_node_argument"), &Example::test_node_argument);
 	ClassDB::bind_method(D_METHOD("test_string_ops"), &Example::test_string_ops);
 	ClassDB::bind_method(D_METHOD("test_str_utility"), &Example::test_str_utility);
+	ClassDB::bind_method(D_METHOD("test_string_is_fourty_two"), &Example::test_string_is_fourty_two);
+	ClassDB::bind_method(D_METHOD("test_string_resize"), &Example::test_string_resize);
 	ClassDB::bind_method(D_METHOD("test_vector_ops"), &Example::test_vector_ops);
 
+	ClassDB::bind_method(D_METHOD("test_object_cast_to_node", "object"), &Example::test_object_cast_to_node);
+	ClassDB::bind_method(D_METHOD("test_object_cast_to_control", "object"), &Example::test_object_cast_to_control);
+	ClassDB::bind_method(D_METHOD("test_object_cast_to_example", "object"), &Example::test_object_cast_to_example);
+
+	ClassDB::bind_method(D_METHOD("test_variant_vector2i_conversion", "variant"), &Example::test_variant_vector2i_conversion);
+	ClassDB::bind_method(D_METHOD("test_variant_int_conversion", "variant"), &Example::test_variant_int_conversion);
+	ClassDB::bind_method(D_METHOD("test_variant_float_conversion", "variant"), &Example::test_variant_float_conversion);
+
+	ClassDB::bind_method(D_METHOD("test_add_child", "node"), &Example::test_add_child);
+	ClassDB::bind_method(D_METHOD("test_set_tileset", "tilemap", "tileset"), &Example::test_set_tileset);
+
+	ClassDB::bind_method(D_METHOD("test_variant_call", "variant"), &Example::test_variant_call);
+
+	ClassDB::bind_method(D_METHOD("test_callable_mp"), &Example::test_callable_mp);
+	ClassDB::bind_method(D_METHOD("test_callable_mp_ret"), &Example::test_callable_mp_ret);
+	ClassDB::bind_method(D_METHOD("test_callable_mp_retc"), &Example::test_callable_mp_retc);
+	ClassDB::bind_method(D_METHOD("test_callable_mp_static"), &Example::test_callable_mp_static);
+	ClassDB::bind_method(D_METHOD("test_callable_mp_static_ret"), &Example::test_callable_mp_static_ret);
+	ClassDB::bind_method(D_METHOD("test_custom_callable"), &Example::test_custom_callable);
+
 	ClassDB::bind_method(D_METHOD("test_bitfield", "flags"), &Example::test_bitfield);
 
+	ClassDB::bind_method(D_METHOD("test_variant_iterator", "input"), &Example::test_variant_iterator);
+
 	ClassDB::bind_method(D_METHOD("test_rpc", "value"), &Example::test_rpc);
 	ClassDB::bind_method(D_METHOD("test_send_rpc", "value"), &Example::test_send_rpc);
 	ClassDB::bind_method(D_METHOD("return_last_rpc_arg"), &Example::return_last_rpc_arg);
 
 	ClassDB::bind_method(D_METHOD("def_args", "a", "b"), &Example::def_args, DEFVAL(100), DEFVAL(200));
+	ClassDB::bind_method(D_METHOD("callable_bind"), &Example::callable_bind);
+	ClassDB::bind_method(D_METHOD("test_post_initialize"), &Example::test_post_initialize);
 
 	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);
@@ -299,6 +381,20 @@ String Example::test_str_utility() const {
 	return UtilityFunctions::str("Hello, ", "World", "! The answer is ", 42);
 }
 
+bool Example::test_string_is_fourty_two(const String &p_string) const {
+	return strcmp(p_string.utf8().ptr(), "fourty two") == 0;
+}
+
+String Example::test_string_resize(String p_string) const {
+	int orig_len = p_string.length();
+	p_string.resize(orig_len + 3);
+	char32_t *data = p_string.ptrw();
+	data[orig_len + 0] = '!';
+	data[orig_len + 1] = '?';
+	data[orig_len + 2] = '\0';
+	return p_string;
+}
+
 int Example::test_vector_ops() const {
 	PackedInt32Array arr;
 	arr.push_back(10);
@@ -312,6 +408,68 @@ int Example::test_vector_ops() const {
 	return ret;
 }
 
+Callable Example::test_callable_mp() {
+	return callable_mp(this, &Example::unbound_method1);
+}
+
+Callable Example::test_callable_mp_ret() {
+	return callable_mp(this, &Example::unbound_method2);
+}
+
+Callable Example::test_callable_mp_retc() const {
+	return callable_mp(this, &Example::unbound_method3);
+}
+
+Callable Example::test_callable_mp_static() const {
+	return callable_mp_static(&Example::unbound_static_method1);
+}
+
+Callable Example::test_callable_mp_static_ret() const {
+	return callable_mp_static(&Example::unbound_static_method2);
+}
+
+Callable Example::test_custom_callable() const {
+	return Callable(memnew(MyCallableCustom));
+}
+
+void Example::unbound_method1(Object *p_object, String p_string, int p_int) {
+	String test = "unbound_method1: ";
+	test += p_object->get_class();
+	test += " - " + p_string;
+	emit_custom_signal(test, p_int);
+}
+
+String Example::unbound_method2(Object *p_object, String p_string, int p_int) {
+	String test = "unbound_method2: ";
+	test += p_object->get_class();
+	test += " - " + p_string;
+	test += " - " + itos(p_int);
+	return test;
+}
+
+String Example::unbound_method3(Object *p_object, String p_string, int p_int) const {
+	String test = "unbound_method3: ";
+	test += p_object->get_class();
+	test += " - " + p_string;
+	test += " - " + itos(p_int);
+	return test;
+}
+
+void Example::unbound_static_method1(Example *p_object, String p_string, int p_int) {
+	String test = "unbound_static_method1: ";
+	test += p_object->get_class();
+	test += " - " + p_string;
+	p_object->emit_custom_signal(test, p_int);
+}
+
+String Example::unbound_static_method2(Object *p_object, String p_string, int p_int) {
+	String test = "unbound_static_method2: ";
+	test += p_object->get_class();
+	test += " - " + p_string;
+	test += " - " + itos(p_int);
+	return test;
+}
+
 int Example::test_tarray_arg(const TypedArray<int64_t> &p_array) {
 	int sum = 0;
 	for (int i = 0; i < p_array.size(); i++) {
@@ -343,10 +501,81 @@ Example *Example::test_node_argument(Example *p_node) const {
 	return p_node;
 }
 
+bool Example::test_object_cast_to_node(Object *p_object) const {
+	return Object::cast_to<Node>(p_object) != nullptr;
+}
+
+bool Example::test_object_cast_to_control(Object *p_object) const {
+	return Object::cast_to<Control>(p_object) != nullptr;
+}
+
+bool Example::test_object_cast_to_example(Object *p_object) const {
+	return Object::cast_to<Example>(p_object) != nullptr;
+}
+
+Vector2i Example::test_variant_vector2i_conversion(const Variant &p_variant) const {
+	return p_variant;
+}
+
+int Example::test_variant_int_conversion(const Variant &p_variant) const {
+	return p_variant;
+}
+
+float Example::test_variant_float_conversion(const Variant &p_variant) const {
+	return p_variant;
+}
+
+void Example::test_add_child(Node *p_node) {
+	add_child(p_node);
+}
+
+void Example::test_set_tileset(TileMap *p_tilemap, const Ref<TileSet> &p_tileset) const {
+	p_tilemap->set_tileset(p_tileset);
+}
+
+Variant Example::test_variant_call(Variant p_variant) {
+	return p_variant.call("test", "hello");
+}
+
 BitField<Example::Flags> Example::test_bitfield(BitField<Flags> flags) {
 	return flags;
 }
 
+Variant Example::test_variant_iterator(const Variant &p_input) {
+	Array output;
+
+	Variant iter;
+
+	bool is_init_valid = true;
+	if (!p_input.iter_init(iter, is_init_valid)) {
+		if (!is_init_valid) {
+			return "iter_init: not valid";
+		}
+		return output;
+	}
+
+	bool is_iter_next_valid = true;
+	bool is_iter_get_valid = true;
+	do {
+		if (!is_iter_next_valid) {
+			return "iter_next: not valid";
+		}
+
+		Variant value = p_input.iter_get(iter, is_iter_get_valid);
+		if (!is_iter_get_valid) {
+			return "iter_get: not valid";
+		}
+		output.push_back(((int)value) + 5);
+
+	} while (p_input.iter_next(iter, is_iter_next_valid));
+
+	if (!is_iter_next_valid) {
+		return "iter_next: not valid";
+	}
+
+	return output;
+}
+
 void Example::test_rpc(int p_value) {
 	last_rpc_arg = p_value;
 }
@@ -359,6 +588,11 @@ int Example::return_last_rpc_arg() {
 	return last_rpc_arg;
 }
 
+void Example::callable_bind() {
+	Callable c = Callable(this, "emit_custom_signal").bind("bound", 11);
+	c.call();
+}
+
 // Properties.
 void Example::set_custom_position(const Vector2 &pos) {
 	custom_position = pos;
@@ -372,6 +606,12 @@ Vector4 Example::get_v4() const {
 	return Vector4(1.2, 3.4, 5.6, 7.8);
 }
 
+bool Example::test_post_initialize() const {
+	Ref<ExampleRef> new_example_ref;
+	new_example_ref.instantiate();
+	return new_example_ref->was_post_initialized();
+}
+
 // Virtual function override.
 bool Example::_has_point(const Vector2 &point) const {
 	Label *label = get_node<Label>("Label");

test/src/example.h

@@ -18,7 +18,10 @@
 #include <godot_cpp/classes/global_constants.hpp>
 #include <godot_cpp/classes/image.hpp>
 #include <godot_cpp/classes/input_event_key.hpp>
+#include <godot_cpp/classes/tile_map.hpp>
+#include <godot_cpp/classes/tile_set.hpp>
 #include <godot_cpp/classes/viewport.hpp>
+#include <godot_cpp/variant/variant.hpp>
 
 #include <godot_cpp/core/binder_common.hpp>
 
@@ -32,16 +35,21 @@ private:
 	static int last_id;
 
 	int id;
+	bool post_initialized = false;
 
 protected:
 	static void _bind_methods();
 
+	void _notification(int p_what);
+
 public:
 	ExampleRef();
 	~ExampleRef();
 
 	void set_id(int p_id);
 	int get_id() const;
+
+	bool was_post_initialized() const { return post_initialized; }
 };
 
 class ExampleMin : public Control {
@@ -63,6 +71,7 @@ protected:
 	void _get_property_list(List<PropertyInfo> *p_list) const;
 	bool _property_can_revert(const StringName &p_name) const;
 	bool _property_get_revert(const StringName &p_name, Variant &r_property) const;
+	void _validate_property(PropertyInfo &p_property) const;
 
 	String _to_string() const;
 
@@ -117,20 +126,54 @@ public:
 	Example *test_node_argument(Example *p_node) const;
 	String test_string_ops() const;
 	String test_str_utility() const;
+	bool test_string_is_fourty_two(const String &p_str) const;
+	String test_string_resize(String p_original) const;
 	int test_vector_ops() const;
 
+	bool test_object_cast_to_node(Object *p_object) const;
+	bool test_object_cast_to_control(Object *p_object) const;
+	bool test_object_cast_to_example(Object *p_object) const;
+
+	Vector2i test_variant_vector2i_conversion(const Variant &p_variant) const;
+	int test_variant_int_conversion(const Variant &p_variant) const;
+	float test_variant_float_conversion(const Variant &p_variant) const;
+
+	void test_add_child(Node *p_node);
+	void test_set_tileset(TileMap *p_tilemap, const Ref<TileSet> &p_tileset) const;
+
+	Variant test_variant_call(Variant p_variant);
+
+	Callable test_callable_mp();
+	Callable test_callable_mp_ret();
+	Callable test_callable_mp_retc() const;
+	Callable test_callable_mp_static() const;
+	Callable test_callable_mp_static_ret() const;
+	Callable test_custom_callable() const;
+
+	void unbound_method1(Object *p_object, String p_string, int p_int);
+	String unbound_method2(Object *p_object, String p_string, int p_int);
+	String unbound_method3(Object *p_object, String p_string, int p_int) const;
+	static void unbound_static_method1(Example *p_object, String p_string, int p_int);
+	static String unbound_static_method2(Object *p_object, String p_string, int p_int);
+
 	BitField<Flags> test_bitfield(BitField<Flags> flags);
 
+	Variant test_variant_iterator(const Variant &p_input);
+
 	// RPC
 	void test_rpc(int p_value);
 	void test_send_rpc(int p_value);
 	int return_last_rpc_arg();
 
+	void callable_bind();
+
 	// Property.
 	void set_custom_position(const Vector2 &pos);
 	Vector2 get_custom_position() const;
 	Vector4 get_v4() const;
 
+	bool test_post_initialize() const;
+
 	// Static method.
 	static int test_static(int p_a, int p_b);
 	static void test_static2();

tools/android.py

@@ -8,41 +8,51 @@ def options(opts):
     opts.Add(
         "android_api_level",
         "Target Android API level",
-        "18" if "32" in ARGUMENTS.get("arch", "arm64") else "21",
+        "21",
     )
     opts.Add(
-        "ANDROID_NDK_ROOT",
-        "Path to your Android NDK installation. By default, uses ANDROID_NDK_ROOT from your defined environment variables.",
-        os.environ.get("ANDROID_NDK_ROOT", None),
+        "ANDROID_HOME",
+        "Path to your Android SDK installation. By default, uses ANDROID_HOME from your defined environment variables.",
+        os.environ.get("ANDROID_HOME", os.environ.get("ANDROID_SDK_ROOT")),
     )
 
 
 def exists(env):
-    return "ANDROID_NDK_ROOT" in os.environ or "ANDROID_NDK_ROOT" in ARGUMENTS
+    return get_android_ndk_root(env) is not None
+
+
+# This must be kept in sync with the value in https://github.com/godotengine/godot/blob/master/platform/android/detect.py#L58.
+def get_ndk_version():
+    return "23.2.8568313"
+
+
+def get_android_ndk_root(env):
+    if env["ANDROID_HOME"]:
+        return env["ANDROID_HOME"] + "/ndk/" + get_ndk_version()
+    else:
+        return os.environ.get("ANDROID_NDK_ROOT")
 
 
 def generate(env):
-    if "ANDROID_NDK_ROOT" not in env:
+    if get_android_ndk_root(env) is None:
         raise ValueError(
-            "To build for Android, ANDROID_NDK_ROOT must be defined. Please set ANDROID_NDK_ROOT to the root folder of your Android NDK installation."
+            "To build for Android, the path to the NDK must be defined. Please set ANDROID_HOME to the root folder of your Android SDK installation."
         )
 
     if env["arch"] not in ("arm64", "x86_64", "arm32", "x86_32"):
         print("Only arm64, x86_64, arm32, and x86_32 are supported on Android. Exiting.")
-        Exit()
+        env.Exit(1)
 
     if sys.platform == "win32" or sys.platform == "msys":
         my_spawn.configure(env)
 
     # Validate API level
-    api_level = int(env["android_api_level"])
-    if "64" in env["arch"] and api_level < 21:
-        print("WARN: 64-bit Android architectures require an API level of at least 21; setting android_api_level=21")
+    if int(env["android_api_level"]) < 21:
+        print("WARNING: minimum supported Android target api is 21. Forcing target api 21.")
         env["android_api_level"] = "21"
-        api_level = 21
 
     # Setup toolchain
-    toolchain = env["ANDROID_NDK_ROOT"] + "/toolchains/llvm/prebuilt/"
+    toolchain = get_android_ndk_root(env) + "/toolchains/llvm/prebuilt/"
     if sys.platform == "win32" or sys.platform == "msys":
         toolchain += "windows"
         import platform as pltfm
@@ -100,3 +110,5 @@ def generate(env):
     )
     env.Append(CCFLAGS=arch_info["ccflags"])
     env.Append(LINKFLAGS=["--target=" + arch_info["target"] + env["android_api_level"], "-march=" + arch_info["march"]])
+
+    env.Append(CPPDEFINES=["ANDROID_ENABLED", "UNIX_ENABLED"])

tools/godotcpp.py

@@ -0,0 +1,361 @@
+import os, sys, platform
+
+from SCons.Variables import EnumVariable, PathVariable, BoolVariable
+from SCons.Tool import Tool
+from SCons.Builder import Builder
+from SCons.Errors import UserError
+
+from binding_generator import scons_generate_bindings, scons_emit_files
+
+
+def add_sources(sources, dir, extension):
+    for f in os.listdir(dir):
+        if f.endswith("." + extension):
+            sources.append(dir + "/" + f)
+
+
+def normalize_path(val, env):
+    return val if os.path.isabs(val) else os.path.join(env.Dir("#").abspath, val)
+
+
+def validate_file(key, val, env):
+    if not os.path.isfile(normalize_path(val, env)):
+        raise UserError("'%s' is not a file: %s" % (key, val))
+
+
+def validate_dir(key, val, env):
+    if not os.path.isdir(normalize_path(val, env)):
+        raise UserError("'%s' is not a directory: %s" % (key, val))
+
+
+def validate_parent_dir(key, val, env):
+    if not os.path.isdir(normalize_path(os.path.dirname(val), env)):
+        raise UserError("'%s' is not a directory: %s" % (key, os.path.dirname(val)))
+
+
+platforms = ("linux", "macos", "windows", "android", "ios", "web")
+
+# CPU architecture options.
+architecture_array = [
+    "",
+    "universal",
+    "x86_32",
+    "x86_64",
+    "arm32",
+    "arm64",
+    "rv64",
+    "ppc32",
+    "ppc64",
+    "wasm32",
+]
+architecture_aliases = {
+    "x64": "x86_64",
+    "amd64": "x86_64",
+    "armv7": "arm32",
+    "armv8": "arm64",
+    "arm64v8": "arm64",
+    "aarch64": "arm64",
+    "rv": "rv64",
+    "riscv": "rv64",
+    "riscv64": "rv64",
+    "ppcle": "ppc32",
+    "ppc": "ppc32",
+    "ppc64le": "ppc64",
+}
+
+
+def exists(env):
+    return True
+
+
+def options(opts, env):
+    # Try to detect the host platform automatically.
+    # This is used if no `platform` argument is passed
+    if sys.platform.startswith("linux"):
+        default_platform = "linux"
+    elif sys.platform == "darwin":
+        default_platform = "macos"
+    elif sys.platform == "win32" or sys.platform == "msys":
+        default_platform = "windows"
+    elif ARGUMENTS.get("platform", ""):
+        default_platform = ARGUMENTS.get("platform")
+    else:
+        raise ValueError("Could not detect platform automatically, please specify with platform=<platform>")
+
+    opts.Add(
+        EnumVariable(
+            key="platform",
+            help="Target platform",
+            default=env.get("platform", default_platform),
+            allowed_values=platforms,
+            ignorecase=2,
+        )
+    )
+
+    # Editor and template_debug are compatible (i.e. you can use the same binary for Godot editor builds and Godot debug templates).
+    # Godot release templates are only compatible with "template_release" builds.
+    # For this reason, we default to template_debug builds, unlike Godot which defaults to editor builds.
+    opts.Add(
+        EnumVariable(
+            key="target",
+            help="Compilation target",
+            default=env.get("target", "template_debug"),
+            allowed_values=("editor", "template_release", "template_debug"),
+        )
+    )
+    opts.Add(
+        PathVariable(
+            key="gdextension_dir",
+            help="Path to a custom directory containing GDExtension interface header and API JSON file",
+            default=env.get("gdextension_dir", None),
+            validator=validate_dir,
+        )
+    )
+    opts.Add(
+        PathVariable(
+            key="custom_api_file",
+            help="Path to a custom GDExtension API JSON file (takes precedence over `gdextension_dir`)",
+            default=env.get("custom_api_file", None),
+            validator=validate_file,
+        )
+    )
+    opts.Add(
+        BoolVariable(
+            key="generate_bindings",
+            help="Force GDExtension API bindings generation. Auto-detected by default.",
+            default=env.get("generate_bindings", False),
+        )
+    )
+    opts.Add(
+        BoolVariable(
+            key="generate_template_get_node",
+            help="Generate a template version of the Node class's get_node.",
+            default=env.get("generate_template_get_node", True),
+        )
+    )
+    opts.Add(
+        BoolVariable(
+            key="build_library",
+            help="Build the godot-cpp library.",
+            default=env.get("build_library", True),
+        )
+    )
+    opts.Add(
+        EnumVariable(
+            key="precision",
+            help="Set the floating-point precision level",
+            default=env.get("precision", "single"),
+            allowed_values=("single", "double"),
+        )
+    )
+    opts.Add(
+        EnumVariable(
+            key="arch",
+            help="CPU architecture",
+            default=env.get("arch", ""),
+            allowed_values=architecture_array,
+            map=architecture_aliases,
+        )
+    )
+
+    # compiledb
+    opts.Add(
+        BoolVariable(
+            key="compiledb",
+            help="Generate compilation DB (`compile_commands.json`) for external tools",
+            default=env.get("compiledb", False),
+        )
+    )
+    opts.Add(
+        PathVariable(
+            key="compiledb_file",
+            help="Path to a custom `compile_commands.json` file",
+            default=env.get("compiledb_file", "compile_commands.json"),
+            validator=validate_parent_dir,
+        )
+    )
+
+    opts.Add(
+        BoolVariable(
+            key="use_hot_reload",
+            help="Enable the extra accounting required to support hot reload.",
+            default=env.get("use_hot_reload", None),
+        )
+    )
+
+    opts.Add(
+        BoolVariable(
+            "disable_exceptions", "Force disabling exception handling code", default=env.get("disable_exceptions", True)
+        )
+    )
+
+    opts.Add(
+        EnumVariable(
+            key="symbols_visibility",
+            help="Symbols visibility on GNU platforms. Use 'auto' to apply the default value.",
+            default=env.get("symbols_visibility", "hidden"),
+            allowed_values=["auto", "visible", "hidden"],
+        )
+    )
+
+    # Add platform options
+    for pl in platforms:
+        tool = Tool(pl, toolpath=["tools"])
+        if hasattr(tool, "options"):
+            tool.options(opts)
+
+    # Targets flags tool (optimizations, debug symbols)
+    target_tool = Tool("targets", toolpath=["tools"])
+    target_tool.options(opts)
+
+
+def generate(env):
+    # Default num_jobs to local cpu count if not user specified.
+    # SCons has a peculiarity where user-specified options won't be overridden
+    # by SetOption, so we can rely on this to know if we should use our default.
+    initial_num_jobs = env.GetOption("num_jobs")
+    altered_num_jobs = initial_num_jobs + 1
+    env.SetOption("num_jobs", altered_num_jobs)
+    if env.GetOption("num_jobs") == altered_num_jobs:
+        cpu_count = os.cpu_count()
+        if cpu_count is None:
+            print("Couldn't auto-detect CPU count to configure build parallelism. Specify it with the -j argument.")
+        else:
+            safer_cpu_count = cpu_count if cpu_count <= 4 else cpu_count - 1
+            print(
+                "Auto-detected %d CPU cores available for build parallelism. Using %d cores by default. You can override it with the -j argument."
+                % (cpu_count, safer_cpu_count)
+            )
+            env.SetOption("num_jobs", safer_cpu_count)
+
+    # Process CPU architecture argument.
+    if env["arch"] == "":
+        # No architecture specified. Default to arm64 if building for Android,
+        # universal if building for macOS or iOS, wasm32 if building for web,
+        # otherwise default to the host architecture.
+        if env["platform"] in ["macos", "ios"]:
+            env["arch"] = "universal"
+        elif env["platform"] == "android":
+            env["arch"] = "arm64"
+        elif env["platform"] == "web":
+            env["arch"] = "wasm32"
+        else:
+            host_machine = platform.machine().lower()
+            if host_machine in architecture_array:
+                env["arch"] = host_machine
+            elif host_machine in architecture_aliases.keys():
+                env["arch"] = architecture_aliases[host_machine]
+            elif "86" in host_machine:
+                # Catches x86, i386, i486, i586, i686, etc.
+                env["arch"] = "x86_32"
+            else:
+                print("Unsupported CPU architecture: " + host_machine)
+                env.Exit(1)
+
+    print("Building for architecture " + env["arch"] + " on platform " + env["platform"])
+
+    if env.get("use_hot_reload") is None:
+        env["use_hot_reload"] = env["target"] != "template_release"
+    if env["use_hot_reload"]:
+        env.Append(CPPDEFINES=["HOT_RELOAD_ENABLED"])
+
+    tool = Tool(env["platform"], toolpath=["tools"])
+
+    if tool is None or not tool.exists(env):
+        raise ValueError("Required toolchain not found for platform " + env["platform"])
+
+    tool.generate(env)
+    target_tool = Tool("targets", toolpath=["tools"])
+    target_tool.generate(env)
+
+    # Disable exception handling. Godot doesn't use exceptions anywhere, and this
+    # saves around 20% of binary size and very significant build time.
+    if env["disable_exceptions"]:
+        if env.get("is_msvc", False):
+            env.Append(CPPDEFINES=[("_HAS_EXCEPTIONS", 0)])
+        else:
+            env.Append(CXXFLAGS=["-fno-exceptions"])
+    elif env.get("is_msvc", False):
+        env.Append(CXXFLAGS=["/EHsc"])
+
+    if not env.get("is_msvc", False):
+        if env["symbols_visibility"] == "visible":
+            env.Append(CCFLAGS=["-fvisibility=default"])
+            env.Append(LINKFLAGS=["-fvisibility=default"])
+        elif env["symbols_visibility"] == "hidden":
+            env.Append(CCFLAGS=["-fvisibility=hidden"])
+            env.Append(LINKFLAGS=["-fvisibility=hidden"])
+
+    # Require C++17
+    if env.get("is_msvc", False):
+        env.Append(CXXFLAGS=["/std:c++17"])
+    else:
+        env.Append(CXXFLAGS=["-std=c++17"])
+
+    if env["precision"] == "double":
+        env.Append(CPPDEFINES=["REAL_T_IS_DOUBLE"])
+
+    # Suffix
+    suffix = ".{}.{}".format(env["platform"], env["target"])
+    if env.dev_build:
+        suffix += ".dev"
+    if env["precision"] == "double":
+        suffix += ".double"
+    suffix += "." + env["arch"]
+    if env["ios_simulator"]:
+        suffix += ".simulator"
+
+    env["suffix"] = suffix  # Exposed when included from another project
+    env["OBJSUFFIX"] = suffix + env["OBJSUFFIX"]
+
+    # compile_commands.json
+    env.Tool("compilation_db")
+    env.Alias("compiledb", env.CompilationDatabase(normalize_path(env["compiledb_file"], env)))
+
+    # Builders
+    env.Append(BUILDERS={"GodotCPPBindings": Builder(action=scons_generate_bindings, emitter=scons_emit_files)})
+    env.AddMethod(_godot_cpp, "GodotCPP")
+
+
+def _godot_cpp(env):
+    extension_dir = normalize_path(env.get("gdextension_dir", env.Dir("gdextension").abspath), env)
+    api_file = normalize_path(env.get("custom_api_file", env.File(extension_dir + "/extension_api.json").abspath), env)
+    bindings = env.GodotCPPBindings(
+        env.Dir("."),
+        [
+            api_file,
+            os.path.join(extension_dir, "gdextension_interface.h"),
+            "binding_generator.py",
+        ],
+    )
+    # Forces bindings regeneration.
+    if env["generate_bindings"]:
+        env.AlwaysBuild(bindings)
+        env.NoCache(bindings)
+
+    # Sources to compile
+    sources = []
+    add_sources(sources, "src", "cpp")
+    add_sources(sources, "src/classes", "cpp")
+    add_sources(sources, "src/core", "cpp")
+    add_sources(sources, "src/variant", "cpp")
+    sources.extend([f for f in bindings if str(f).endswith(".cpp")])
+
+    # Includes
+    env.AppendUnique(CPPPATH=[env.Dir(d) for d in [extension_dir, "include", "gen/include"]])
+
+    library = None
+    library_name = "libgodot-cpp" + env["suffix"] + env["LIBSUFFIX"]
+
+    if env["build_library"]:
+        library = env.StaticLibrary(target=env.File("bin/%s" % library_name), source=sources)
+        default_args = [library]
+
+        # Add compiledb if the option is set
+        if env.get("compiledb", False):
+            default_args += ["compiledb"]
+
+        env.Default(*default_args)
+
+    env.AppendUnique(LIBS=[env.File("bin/%s" % library_name)])
+    return library

tools/ios.py

@@ -1,7 +1,6 @@
 import os
 import sys
 import subprocess
-import ios_osxcross
 from SCons.Variables import *
 
 if sys.version_info < (3,):
@@ -16,26 +15,31 @@ else:
         return codecs.utf_8_decode(x)[0]
 
 
+def has_ios_osxcross():
+    return "OSXCROSS_IOS" in os.environ
+
+
 def options(opts):
     opts.Add(BoolVariable("ios_simulator", "Target iOS Simulator", False))
-    opts.Add("ios_min_version", "Target minimum iphoneos/iphonesimulator version", "10.0")
+    opts.Add("ios_min_version", "Target minimum iphoneos/iphonesimulator version", "12.0")
     opts.Add(
         "IOS_TOOLCHAIN_PATH",
         "Path to iOS toolchain",
         "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain",
     )
     opts.Add("IOS_SDK_PATH", "Path to the iOS SDK", "")
-    ios_osxcross.options(opts)
+
+    if has_ios_osxcross():
+        opts.Add("ios_triple", "Triple for ios toolchain", "")
 
 
 def exists(env):
-    return sys.platform == "darwin" or ios_osxcross.exists(env)
+    return sys.platform == "darwin" or has_ios_osxcross()
 
 
 def generate(env):
     if env["arch"] not in ("universal", "arm64", "x86_64"):
-        print("Only universal, arm64, and x86_64 are supported on iOS. Exiting.")
-        Exit()
+        raise ValueError("Only universal, arm64, and x86_64 are supported on iOS. Exiting.")
 
     if env["ios_simulator"]:
         sdk_name = "iphonesimulator"
@@ -64,7 +68,26 @@ def generate(env):
         env["ENV"]["PATH"] = env["IOS_TOOLCHAIN_PATH"] + "/Developer/usr/bin/:" + env["ENV"]["PATH"]
 
     else:
-        ios_osxcross.generate(env)
+        # OSXCross
+        compiler_path = "$IOS_TOOLCHAIN_PATH/usr/bin/${ios_triple}"
+        env["CC"] = compiler_path + "clang"
+        env["CXX"] = compiler_path + "clang++"
+        env["AR"] = compiler_path + "ar"
+        env["RANLIB"] = compiler_path + "ranlib"
+        env["SHLIBSUFFIX"] = ".dylib"
+
+        env.Prepend(
+            CPPPATH=[
+                "$IOS_SDK_PATH/usr/include",
+                "$IOS_SDK_PATH/System/Library/Frameworks/AudioUnit.framework/Headers",
+            ]
+        )
+
+        env.Append(CCFLAGS=["-stdlib=libc++"])
+
+        binpath = os.path.join(env["IOS_TOOLCHAIN_PATH"], "usr", "bin")
+        if binpath not in env["ENV"]["PATH"]:
+            env.PrependENVPath("PATH", binpath)
 
     if env["arch"] == "universal":
         if env["ios_simulator"]:
@@ -79,3 +102,5 @@ def generate(env):
 
     env.Append(CCFLAGS=["-isysroot", env["IOS_SDK_PATH"]])
     env.Append(LINKFLAGS=["-isysroot", env["IOS_SDK_PATH"], "-F" + env["IOS_SDK_PATH"]])
+
+    env.Append(CPPDEFINES=["IOS_ENABLED", "UNIX_ENABLED"])

tools/ios_osxcross.py

@@ -1,26 +0,0 @@
-import os
-
-
-def options(opts):
-    opts.Add("ios_triple", "Triple for ios toolchain", "")
-
-
-def exists(env):
-    return "OSXCROSS_IOS" in os.environ
-
-
-def generate(env):
-    compiler_path = "$IOS_TOOLCHAIN_PATH/usr/bin/${ios_triple}"
-    env["CC"] = compiler_path + "clang"
-    env["CXX"] = compiler_path + "clang++"
-    env["AR"] = compiler_path + "ar"
-    env["RANLIB"] = compiler_path + "ranlib"
-    env["SHLIBSUFFIX"] = ".dylib"
-
-    env.Prepend(
-        CPPPATH=[
-            "$IOS_SDK_PATH/usr/include",
-            "$IOS_SDK_PATH/System/Library/Frameworks/AudioUnit.framework/Headers",
-        ]
-    )
-    env.Append(CCFLAGS=["-stdlib=libc++"])

tools/linux.py

@@ -14,6 +14,9 @@ def generate(env):
     if env["use_llvm"]:
         clang.generate(env)
         clangxx.generate(env)
+    elif env["use_hot_reload"]:
+        # Required for extensions to truly unload.
+        env.Append(CXXFLAGS=["-fno-gnu-unique"])
 
     env.Append(CCFLAGS=["-fPIC", "-Wwrite-strings"])
     env.Append(LINKFLAGS=["-Wl,-R,'$$ORIGIN'"])
@@ -32,3 +35,5 @@ def generate(env):
     elif env["arch"] == "rv64":
         env.Append(CCFLAGS=["-march=rv64gc"])
         env.Append(LINKFLAGS=["-march=rv64gc"])
+
+    env.Append(CPPDEFINES=["LINUX_ENABLED", "UNIX_ENABLED"])

tools/macos.py

@@ -1,31 +1,51 @@
 import os
 import sys
-import macos_osxcross
+
+
+def has_osxcross():
+    return "OSXCROSS_ROOT" in os.environ
 
 
 def options(opts):
     opts.Add("macos_deployment_target", "macOS deployment target", "default")
     opts.Add("macos_sdk_path", "macOS SDK path", "")
-    macos_osxcross.options(opts)
+    if has_osxcross():
+        opts.Add("osxcross_sdk", "OSXCross SDK version", "darwin16")
 
 
 def exists(env):
-    return sys.platform == "darwin" or macos_osxcross.exists(env)
+    return sys.platform == "darwin" or has_osxcross()
 
 
 def generate(env):
     if env["arch"] not in ("universal", "arm64", "x86_64"):
         print("Only universal, arm64, and x86_64 are supported on macOS. Exiting.")
-        Exit()
+        env.Exit(1)
 
     if sys.platform == "darwin":
         # Use clang on macOS by default
         env["CXX"] = "clang++"
         env["CC"] = "clang"
     else:
-        # Use osxcross
-        macos_osxcross.generate(env)
+        # OSXCross
+        root = os.environ.get("OSXCROSS_ROOT", "")
+        if env["arch"] == "arm64":
+            basecmd = root + "/target/bin/arm64-apple-" + env["osxcross_sdk"] + "-"
+        else:
+            basecmd = root + "/target/bin/x86_64-apple-" + env["osxcross_sdk"] + "-"
 
+        env["CC"] = basecmd + "clang"
+        env["CXX"] = basecmd + "clang++"
+        env["AR"] = basecmd + "ar"
+        env["RANLIB"] = basecmd + "ranlib"
+        env["AS"] = basecmd + "as"
+
+        binpath = os.path.join(root, "target", "bin")
+        if binpath not in env["ENV"]["PATH"]:
+            # Add OSXCROSS bin folder to PATH (required for linking).
+            env.PrependENVPath("PATH", binpath)
+
+    # Common flags
     if env["arch"] == "universal":
         env.Append(LINKFLAGS=["-arch", "x86_64", "-arch", "arm64"])
         env.Append(CCFLAGS=["-arch", "x86_64", "-arch", "arm64"])
@@ -48,3 +68,5 @@ def generate(env):
             "-Wl,-undefined,dynamic_lookup",
         ]
     )
+
+    env.Append(CPPDEFINES=["MACOS_ENABLED", "UNIX_ENABLED"])

tools/macos_osxcross.py

@@ -1,28 +0,0 @@
-import os
-
-
-def options(opts):
-    opts.Add("osxcross_sdk", "OSXCross SDK version", "darwin16")
-
-
-def exists(env):
-    return "OSXCROSS_ROOT" in os.environ
-
-
-def generate(env):
-    root = os.environ.get("OSXCROSS_ROOT", "")
-    if env["arch"] == "arm64":
-        basecmd = root + "/target/bin/arm64-apple-" + env["osxcross_sdk"] + "-"
-    else:
-        basecmd = root + "/target/bin/x86_64-apple-" + env["osxcross_sdk"] + "-"
-
-    env["CC"] = basecmd + "clang"
-    env["CXX"] = basecmd + "clang++"
-    env["AR"] = basecmd + "ar"
-    env["RANLIB"] = basecmd + "ranlib"
-    env["AS"] = basecmd + "as"
-
-    binpath = os.path.join(root, "target", "bin")
-    if binpath not in env["ENV"]["PATH"]:
-        # Add OSXCROSS bin folder to PATH (required for linking).
-        env["ENV"]["PATH"] = "%s:%s" % (binpath, env["ENV"]["PATH"])

tools/targets.py

@@ -1,10 +1,14 @@
 import os
+import subprocess
 import sys
 from SCons.Script import ARGUMENTS
 from SCons.Variables import *
 from SCons.Variables.BoolVariable import _text2bool
 
 
+# Helper methods
+
+
 def get_cmdline_bool(option, default):
     """We use `ARGUMENTS.get()` to check if options were manually overridden on the command line,
     and SCons' _text2bool helper to convert them to booleans, otherwise they're handled as strings.
@@ -16,6 +20,24 @@ def get_cmdline_bool(option, default):
         return default
 
 
+def using_clang(env):
+    return "clang" in os.path.basename(env["CC"])
+
+
+def is_vanilla_clang(env):
+    if not using_clang(env):
+        return False
+    try:
+        version = subprocess.check_output([env.subst(env["CXX"]), "--version"]).strip().decode("utf-8")
+    except (subprocess.CalledProcessError, OSError):
+        print("Couldn't parse CXX environment variable to infer compiler version.")
+        return False
+    return not version.startswith("Apple")
+
+
+# Main tool definition
+
+
 def options(opts):
     opts.Add(
         EnumVariable(
@@ -34,19 +56,21 @@ def exists(env):
 
 
 def generate(env):
+    # Configuration of build targets:
+    # - Editor or template
+    # - Debug features (DEBUG_ENABLED code)
+    # - Dev only code (DEV_ENABLED code)
+    # - Optimization level
+    # - Debug symbols for crash traces / debuggers
+
+    # Keep this configuration in sync with SConstruct in upstream Godot.
+
+    env.editor_build = env["target"] == "editor"
     env.dev_build = env["dev_build"]
     env.debug_features = env["target"] in ["editor", "template_debug"]
-    env.editor_build = env["target"] == "editor"
-
-    if env.editor_build:
-        env.AppendUnique(CPPDEFINES=["TOOLS_ENABLED"])
-
-    if env.debug_features:
-        env.AppendUnique(CPPDEFINES=["DEBUG_ENABLED", "DEBUG_METHODS_ENABLED"])
 
     if env.dev_build:
         opt_level = "none"
-        env.AppendUnique(CPPDEFINES=["DEV_ENABLED"])
     elif env.debug_features:
         opt_level = "speed_trace"
     else:  # Release
@@ -55,29 +79,57 @@ def generate(env):
     env["optimize"] = ARGUMENTS.get("optimize", opt_level)
     env["debug_symbols"] = get_cmdline_bool("debug_symbols", env.dev_build)
 
+    if env.editor_build:
+        env.Append(CPPDEFINES=["TOOLS_ENABLED"])
+
+    if env.debug_features:
+        # DEBUG_ENABLED enables debugging *features* and debug-only code, which is intended
+        # to give *users* extra debugging information for their game development.
+        env.Append(CPPDEFINES=["DEBUG_ENABLED"])
+        # In upstream Godot this is added in typedefs.h when DEBUG_ENABLED is set.
+        env.Append(CPPDEFINES=["DEBUG_METHODS_ENABLED"])
+
+    if env.dev_build:
+        # DEV_ENABLED enables *engine developer* code which should only be compiled for those
+        # working on the engine itself.
+        env.Append(CPPDEFINES=["DEV_ENABLED"])
+    else:
+        # Disable assert() for production targets (only used in thirdparty code).
+        env.Append(CPPDEFINES=["NDEBUG"])
+
+    # Set optimize and debug_symbols flags.
+    # "custom" means do nothing and let users set their own optimization flags.
     if env.get("is_msvc", False):
         if env["debug_symbols"]:
             env.Append(CCFLAGS=["/Zi", "/FS"])
             env.Append(LINKFLAGS=["/DEBUG:FULL"])
 
-        if env["optimize"] == "speed" or env["optimize"] == "speed_trace":
+        if env["optimize"] == "speed":
             env.Append(CCFLAGS=["/O2"])
             env.Append(LINKFLAGS=["/OPT:REF"])
+        elif env["optimize"] == "speed_trace":
+            env.Append(CCFLAGS=["/O2"])
+            env.Append(LINKFLAGS=["/OPT:REF", "/OPT:NOICF"])
         elif env["optimize"] == "size":
             env.Append(CCFLAGS=["/O1"])
             env.Append(LINKFLAGS=["/OPT:REF"])
-
-        if env["optimize"] == "debug" or env["optimize"] == "none":
-            env.Append(CCFLAGS=["/MDd", "/Od"])
-        else:
-            env.Append(CCFLAGS=["/MD"])
-
+        elif env["optimize"] == "debug" or env["optimize"] == "none":
+            env.Append(CCFLAGS=["/Od"])
     else:
         if env["debug_symbols"]:
+            # Adding dwarf-4 explicitly makes stacktraces work with clang builds,
+            # otherwise addr2line doesn't understand them.
+            env.Append(CCFLAGS=["-gdwarf-4"])
             if env.dev_build:
                 env.Append(CCFLAGS=["-g3"])
             else:
                 env.Append(CCFLAGS=["-g2"])
+        else:
+            if using_clang(env) and not is_vanilla_clang(env):
+                # Apple Clang, its linker doesn't like -s.
+                env.Append(LINKFLAGS=["-Wl,-S", "-Wl,-x", "-Wl,-dead_strip"])
+            else:
+                env.Append(LINKFLAGS=["-s"])
 
         if env["optimize"] == "speed":
             env.Append(CCFLAGS=["-O3"])

tools/web.py

@@ -1,45 +1,44 @@
 import os
+from SCons.Util import WhereIs
 
 
 def exists(env):
-    return "EM_CONFIG" in os.environ
+    return WhereIs("emcc") is not None
 
 
 def generate(env):
     if env["arch"] not in ("wasm32"):
         print("Only wasm32 supported on web. Exiting.")
-        Exit()
-
-    if "EM_CONFIG" in os.environ:
-        env["ENV"] = os.environ
+        env.Exit(1)
 
+    # Emscripten toolchain
     env["CC"] = "emcc"
     env["CXX"] = "em++"
     env["AR"] = "emar"
     env["RANLIB"] = "emranlib"
-    env.Append(CPPFLAGS=["-s", "SIDE_MODULE=1"])
-    env.Append(LINKFLAGS=["-s", "SIDE_MODULE=1"])
-    env["SHOBJSUFFIX"] = ".bc"
-    env["SHLIBSUFFIX"] = ".wasm"
+
     # Use TempFileMunge since some AR invocations are too long for cmd.exe.
     # Use POSIX-style paths, required with TempFileMunge.
     env["ARCOM_POSIX"] = env["ARCOM"].replace("$TARGET", "$TARGET.posix").replace("$SOURCES", "$SOURCES.posix")
     env["ARCOM"] = "${TEMPFILE(ARCOM_POSIX)}"
 
-    # All intermediate files are just LLVM bitcode.
-    env["OBJPREFIX"] = ""
-    env["OBJSUFFIX"] = ".bc"
-    env["PROGPREFIX"] = ""
-    # Program() output consists of multiple files, so specify suffixes manually at builder.
-    env["PROGSUFFIX"] = ""
+    # All intermediate files are just object files.
+    env["OBJSUFFIX"] = ".o"
+    env["SHOBJSUFFIX"] = ".o"
+
+    # Static libraries clang-style.
     env["LIBPREFIX"] = "lib"
     env["LIBSUFFIX"] = ".a"
-    env["LIBPREFIXES"] = ["$LIBPREFIX"]
-    env["LIBSUFFIXES"] = ["$LIBSUFFIX"]
-    env.Replace(SHLINKFLAGS="$LINKFLAGS")
-    env.Replace(SHLINKFLAGS="$LINKFLAGS")
 
-    if env["target"] == "debug":
-        env.Append(CCFLAGS=["-O0", "-g"])
-    elif env["target"] == "release":
-        env.Append(CCFLAGS=["-O3"])
+    # Shared library as wasm.
+    env["SHLIBSUFFIX"] = ".wasm"
+
+    # Thread support (via SharedArrayBuffer).
+    env.Append(CCFLAGS=["-s", "USE_PTHREADS=1"])
+    env.Append(LINKFLAGS=["-s", "USE_PTHREADS=1"])
+
+    # Build as side module (shared library).
+    env.Append(CPPFLAGS=["-s", "SIDE_MODULE=1"])
+    env.Append(LINKFLAGS=["-s", "SIDE_MODULE=1"])
+
+    env.Append(CPPDEFINES=["WEB_ENABLED", "UNIX_ENABLED"])

tools/windows.py

@@ -9,6 +9,7 @@ from SCons.Variables import *
 def options(opts):
     opts.Add(BoolVariable("use_mingw", "Use the MinGW compiler instead of MSVC - only effective on Windows", False))
     opts.Add(BoolVariable("use_clang_cl", "Use the clang driver instead of MSVC - only effective on Windows", False))
+    opts.Add(BoolVariable("use_static_cpp", "Link MinGW/MSVC C++ runtime libraries statically", True))
 
 
 def exists(env):
@@ -30,13 +31,18 @@ def generate(env):
         env.Tool("mslink")
 
         env.Append(CPPDEFINES=["TYPED_METHOD_BIND", "NOMINMAX"])
-        env.Append(CCFLAGS=["/EHsc"])
+        env.Append(CCFLAGS=["/utf-8"])
         env.Append(LINKFLAGS=["/WX"])
 
         if env["use_clang_cl"]:
             env["CC"] = "clang-cl"
             env["CXX"] = "clang-cl"
 
+        if env["use_static_cpp"]:
+            env.Append(CCFLAGS=["/MT"])
+        else:
+            env.Append(CCFLAGS=["/MD"])
+
     elif sys.platform == "win32" or sys.platform == "msys":
         env["use_mingw"] = True
         mingw.generate(env)
@@ -45,6 +51,18 @@ def generate(env):
         env["SHLIBPREFIX"] = ""
         # Want dll suffix
         env["SHLIBSUFFIX"] = ".dll"
+
+        env.Append(CCFLAGS=["-Wwrite-strings"])
+        env.Append(LINKFLAGS=["-Wl,--no-undefined"])
+        if env["use_static_cpp"]:
+            env.Append(
+                LINKFLAGS=[
+                    "-static",
+                    "-static-libgcc",
+                    "-static-libstdc++",
+                ]
+            )
+
         # Long line hack. Use custom spawn, quick AR append (to avoid files with the same names to override each other).
         my_spawn.configure(env)
 
@@ -60,13 +78,15 @@ def generate(env):
         # Want dll suffix
         env["SHLIBSUFFIX"] = ".dll"
 
-        # These options are for a release build even using target=debug
-        env.Append(CCFLAGS=["-O3", "-Wwrite-strings"])
-        env.Append(
-            LINKFLAGS=[
-                "--static",
-                "-Wl,--no-undefined",
-                "-static-libgcc",
-                "-static-libstdc++",
-            ]
-        )
+        env.Append(CCFLAGS=["-Wwrite-strings"])
+        env.Append(LINKFLAGS=["-Wl,--no-undefined"])
+        if env["use_static_cpp"]:
+            env.Append(
+                LINKFLAGS=[
+                    "-static",
+                    "-static-libgcc",
+                    "-static-libstdc++",
+                ]
+            )
+
+    env.Append(CPPDEFINES=["WINDOWS_ENABLED"])