WindowsでV8を静的ライブラリとしてビルドする完全ガイド【2025年8月版】

cd c:\
mkdir v8
cd v8
git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git

:: depot_tools を PATH に追加（fetch, gclient, gn, ninja などを使うために必須）
set PATH=C:\v8\depot_tools;%PATH%

:: Google製ツールチェーンを無効化（ローカルのVisual Studioを使う）
set DEPOT_TOOLS_WIN_TOOLCHAIN=0

fetch v8

Updating depot_tools...
WARNING:root:depot_tools recommends setting the following for
optimal Chromium development:

$ git config --global core.autocrlf false
$ git config --global core.filemode false
$ git config --global core.fscache true
$ git config --global core.preloadindex true

You can silence this message by setting these recommended values.

You can allow depot_tools to automatically update your global
Git config to recommended settings by running:
$ git config --global depot-tools.allowGlobalGitConfig true

To suppress this warning and silence future recommendations, run:
$ git config --global depot-tools.allowGlobalGitConfig false
Running: 'C:\Users\yofukashi\AppData\Local\vpython-root.0\store\python_venv-k8oefljjki133rd42po4ai8fe8\contents\Scripts\python3.exe' 'C:\v8\depot_tools\gclient.py' root
Running: 'C:\Users\yofukashi\AppData\Local\vpython-root.0\store\python_venv-k8oefljjki133rd42po4ai8fe8\contents\Scripts\python3.exe' 'C:\v8\depot_tools\gclient.py' config --spec 'solutions = [
  {
    "name": "v8",
    "url": "https://chromium.googlesource.com/v8/v8.git",
    "deps_file": "DEPS",
    "managed": False,
    "custom_deps": {},
  },
]
'
Running: 'C:\Users\yofukashi\AppData\Local\vpython-root.0\store\python_venv-k8oefljjki133rd42po4ai8fe8\contents\Scripts\python3.exe' 'C:\v8\depot_tools\gclient.py' sync --with_branch_heads

________ running 'git -c core.deltaBaseCacheLimit=2g clone --no-checkout --progress https://chromium.googlesource.com/v8/v8.git c:\v8\_gclient_v8_865848xv' in 'c:\v8'
Cloning into 'c:\v8\_gclient_v8_865848xv'...
remote: Sending approximately 1.44 GiB ...
remote: Counting objects: 7469, done
remote: Finding sources: 100% (7/7)
remote: Total 1208282 (delta 958662), reused 1208280 (delta 958662)
Receiving objects: 100% (1208282/1208282), 1.44 GiB | 38.94 MiB/s, done.
Resolving deltas: 100% (958662/958662), done.
1>Syncing projects:   0% ( 0/ 2)
[0:05:16] Still working on:
[0:05:16]   v8

[0:05:16] Still working on:
[0:05:16]   v8
Syncing projects: 100% (44/44), done.

________ running 'python3 third_party/depot_tools/download_from_google_storage.py --no_resume -u --bucket v8-wasm-spec-tests -s test/wasm-spec-tests/tests.tar.gz.sha1' in 'c:\v8\v8'
0> Downloading test/wasm-spec-tests/tests.tar.gz@e8f855c3f80301e3f127eaf18ba426dd6208c4bb...
0> Extracting 483 entries from test/wasm-spec-tests/tests.tar.gz to test/wasm-spec-tests/tests
Downloading 1 files took 8.155261 second(s)
Running hooks:  43% (10/23) wasm_js
________ running 'python3 third_party/depot_tools/download_from_google_storage.py --no_resume -u --bucket v8-wasm-spec-tests -s test/wasm-js/tests.tar.gz.sha1' in 'c:\v8\v8'
0> Downloading test/wasm-js/tests.tar.gz@8a69e14a26326662093099426eff78db6d409761...
0> Extracting 252 entries from test/wasm-js/tests.tar.gz to test/wasm-js/tests
Downloading 1 files took 4.370902 second(s)
Running hooks:  95% (22/23) configure_reclient_cfgs
________ running 'python3 buildtools/reclient_cfgs/configure_reclient_cfgs.py --rbe_instance projects/rbe-chrome-untrusted/instances/default_instance --reproxy_cfg_template reproxy.cfg.template --rewrapper_cfg_project  --skip_remoteexec_cfg_fetch' in 'c:\v8\v8'
generate reproxy.cfg using c:\v8\v8\buildtools\reclient_cfgs\reproxy_cfg_templates\reproxy.cfg.template
Running hooks: 100% (23/23), done.
Running: git config --add remote.origin.fetch '+refs/tags/*:refs/tags/*'
Running: git config diff.ignoreSubmodules dirty

cd v8
gclient sync

cd C:\v8\depot_tools\python-bin
python3 --version

python --version

:: depot_tools を PATH に追加（fetch, gclient, gn, ninja などを使うために必須）
set PATH=C:\v8\depot_tools;%PATH%

:: Google製ツールチェーンを無効化（ローカルのVSを使う）
set DEPOT_TOOLS_WIN_TOOLCHAIN=0

:: GYP に VS2022 を使わせる（任意）
:: set GYP_MSVS_VERSION=2022

:: VS2022 のインストールパス（任意）
:: set GYP_MSVS_OVERRIDE_PATH=C:\Program Files\Microsoft Visual Studio\2022\Community

:: Windows SDK のパス（任意）
:: set WINDOWSSDKDIR=C:\Program Files (x86)\Windows Kits\10

:: V8 のルートディレクトリに移動
cd C:\v8\v8

:: GN 設定を生成（args.gn と build.ninja を作成）
python tools\dev\v8gen.py x64.release

:: args.gn を手動で編集する
gn args out.gn\x64.release

dcheck_always_on = false                # DCHECK（デバッグ用チェック）を無効化してパフォーマンス向上
is_debug = false                        # リリースビルド（最適化あり、デバッグ情報なし）
target_cpu = "x64"                      # 64bit アーキテクチャ向けにビルド
is_component_build = false             # コンポーネント分割なし（単一バイナリ化）
use_custom_libcxx = false              # Google製の libc++ を使わず、標準ライブラリを使用
v8_static_library = true               # 静的ライブラリとして V8 を出力（.lib）
v8_monolithic = true                   # 依存関係をすべて1つのバイナリに統合
v8_enable_pointer_compression = true   # ポインタ圧縮を有効化（メモリ使用量削減）
v8_use_external_startup_data = false   # 起動時の外部データ（snapshot）を使わない
v8_postmortem_support = false          # クラッシュ後のヒープ解析機能を無効化
v8_enable_i18n_support = false         # ICUベースの国際化機能（文字列処理など）を無効化
v8_enable_temporal_support = false     # Temporal API（高精度な日付/時間処理）を無効化
v8_enable_webassembly = false          # WebAssembly 機能を無効化（不要なら除外）

Waiting for editor on "C:\v8\v8\out.gn\x64.release\args.gn"...
Generating files...
Done. Made 563 targets from 141 files in 6647ms

:: フルビルドする場合は、ninja -C out.gn\x64.release、とする
ninja -C out.gn\x64.release v8_monolith

ninja: Entering directory `out.gn\x64.release'
[1565/1565] LIB obj/v8_monolith.lib