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V8

v8 is used as the default JavaScript runtime.

Build V8 from Source (Optional)

NOTE: See Setup V8 in GodotJS if a prebuilt version of v8 from GodotJS-Dependencies is used.

Building V8 from source is needed if you do not want to use the prebuilt version from GodotJS-Dependencies. Follow the steps below:

STEP 1
Download depot_tools from https://storage.googleapis.com/chrome-infra/depot_tools.zip if using Windows, and extract it to a path you want.

Otherwise, get depot_tools from the git repository:

git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git

STEP 2

Add the depot_tools path into the environment variable PATH.

On windows:

set PATH=Your\Path\To\depot_tools;%PATH%
set DEPOT_TOOLS_WIN_TOOLCHAIN=0

NOTE: If DEPOT_TOOLS_WIN_TOOLCHAIN is not set, depot_tools will fail to build because it will try to use the google internal toolchain instead of the locally installed Visual Studio.

On linux, macos: 

export PATH=Your/Path/To/depot_tools:$PATH

STEP 3

Sync and fetch v8:

cd Your/Path/To/depot_tools
gclient 

mkdir -p Your/Path/To/v8 
cd Your/Path/To/v8
fetch v8
cd v8
git checkout refs/tags/12.4.254.20
gclient sync

STEP 4

Generate build configurations:

gn gen ./out.gn/x64.release

Modify the options in out.gn/x64.release/args.gn. See Options

STEP 5

Build:

ninja -C ./out.gn/x64.release v8_monolith

Options Currently Used for Building V8

Windows x64 

is_component_build = false
is_debug = false
target_cpu = "x64"
target_os = "win"
v8_enable_i18n_support = false
v8_monolithic = true
v8_use_external_startup_data = false
v8_enable_pointer_compression = true
v8_jitless = false                  # jit enabled

use_custom_libcxx = false            # false will produce warnings
treat_warnings_as_errors = false    # 
v8_symbol_level = 0                 # smaller lib 
v8_enable_sandbox = false

Macos arm64 

# v8_enable_backtrace = true
# v8_enable_disassembler = true
# v8_enable_object_print = true
# v8_enable_verify_heap = true

dcheck_always_on = false

is_component_build = false
is_debug = false
target_cpu = "arm64"
v8_target_cpu = "arm64"
target_os = "mac"
v8_enable_i18n_support = false
v8_monolithic = true
v8_use_external_startup_data = false
v8_enable_pointer_compression = true
v8_jitless = false                  # jit enabled
v8_enable_webassembly = false

use_custom_libcxx = false            # false will produce warnings
treat_warnings_as_errors = false    # 
v8_symbol_level = 0                 # smaller lib 
v8_enable_sandbox = false 
use_rtti = true

Setup V8 in GodotJS

Follow the instructions below to set it up:

STEP 1: Download or clone the repo into the modules directory of your Godot engine source:

cd YourGodotEngineSource/modules
git clone https://github.com/ialex32x/GodotJS.git

STEP 2: Put v8 headers and libraries into GodotJS, or directly download the prebuilt v8 from GodotJS-Dependencies:

# download the archive of prebuilt v8 
curl https://github.com/ialex32x/GodotJS-Dependencies/releases/download/v8_12.4.254.21_r13/v8_12.4.254.21_r13.zip --output your/download/path/v8.zip

# extract the zip file into your `GodotJS` directory, 
# NOTE: no white space after the switch `-o`
7z x -o"YourGodotEngineSource/modules/GodotJS" your/download/path/v8.zip

NOTE: Don't forget to put the headers/libraries of v8 into the same directory structure used in prebuilt v8 if you decide to compile it by yourself.

The module directroy structure looks like this: 

┗━ godot
    ┗━ modules
        ┣━ ...
        ┣━ gltf
        ┣━ GodotJS
        ┃    ┣━ bridge-quickjs
        ┃    ┣━ bridge-v8
        ┃    ┣━ ...
        ┃    ┣━ lws
        ┃    ┗━ v8
        ┃        ┣━ include
        ┃        ┣━ linux.x86_64.release
        ┃        ┣━ macos.arm64.release
        ┃        ┣━ windows_x86_64_release
        ┃        ┗━ ...
        ┣━ gridmap
        ┣━ ...

The currently used version of v8 is 12.4.254.21.

STEP 3: Compile and launch Godot Editor. Then, you can create a Godot project in TypeScript/JavaScript: * Create-a-TypeScript-Project-from-Scratch * Create-a-JavaScript-Project-from-Scratch

NOTE: Since the prebuilt v8 library is built with the windows-latest github runner which uses VS2022, encountering Unresolved external symbol errors during linkage with v8_monolith.lib or libucrt.lib may be addressed by updating to the latest version of the MSVC v143 toolchain, Windows Universal CRT SDK and Visual Studio 2022 itself. See GodotJS-Dependencies README for the version of MSVC C++ Compiler used in different prebuilt library packages.

A prebuilt version of Godot Editor can be downloaded from GodotJS-Build.
Because the GodotJS-Build workflow is currently run manually, it may not be built from the latest commit of GodotJS.