V8 CMake Build

CMake build system for the V8 JavaScript engine — no depot_tools or GN required. Supports Windows (MSVC), Linux (GCC/Clang), and FreeBSD (Clang).

Each V8 version lives on its own branch with pinned sources, patches, and tested CMake build files. Pick a branch below and follow the instructions there.

Available Versions

Branch	V8 Version	Platforms
v8-14.3.127.18	14.3.127.18	Windows, Linux, FreeBSD
v8-14.1.146.11	14.1.146.11	Windows, Linux
v8-13.6.233.17	13.6.233.17	Windows, Linux
v8-12.4.254.21	12.4.254.21	Windows, Linux
v8-11.3.244.8	11.3.244.8	Windows, Linux
v8-10.2.154.26	10.2.154.26	Windows
v8-9.4.146.26	9.4.146.26	Windows

See each branch's README for detailed test results and platform-specific notes.

What You Get

• Full V8 static library build (all tiers: Sparkplug, Maglev, TurboFan)
• WebAssembly, ICU/Intl support (data embedded — no runtime files needed)
• d8 developer shell
• CMake targets that work with add_subdirectory() or find_package()

Quick Example

Windows (MSVC)

cmake_minimum_required(VERSION 3.20)
project(myapp LANGUAGES CXX C ASM_MASM)

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# V8 defaults to static CRT (/MT) — your project must match
set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")

add_subdirectory("path/to/v8" "${CMAKE_BINARY_DIR}/v8-build")

add_executable(myapp main.cpp)
target_link_libraries(myapp PRIVATE v8)

# From a VS Developer Command Prompt (or use cmake/msvc-toolchain.cmake)
cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build

Linux / FreeBSD (GCC/Clang)

cmake_minimum_required(VERSION 3.20)
project(myapp LANGUAGES CXX C ASM)

set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

add_subdirectory("path/to/v8" "${CMAKE_BINARY_DIR}/v8-build")

add_executable(myapp main.cpp)
target_link_libraries(myapp PRIVATE v8)

cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build

Cross-Platform

The V8 CMake build auto-detects the platform — just set the appropriate project languages (ASM_MASM on Windows, ASM on Linux/FreeBSD) and V8 handles the rest. The v8 target automatically provides include paths, compile definitions (V8_COMPRESS_POINTERS, etc.), and platform-appropriate flags.

Alternatively, install V8 once and use find_package:

# Install V8 SDK
cmake --install <v8-build-dir> --prefix /opt/v8-sdk

find_package(v8 REQUIRED)
target_link_libraries(myapp PRIVATE v8::v8)

Minimal Embedding Code

#include "v8.h"
#include "libplatform/libplatform.h"
#include <iostream>
#include <memory>

int main(int argc, char* argv[]) {
  v8::V8::InitializeICUDefaultLocation(argv[0]);
  v8::V8::InitializeExternalStartupData(argv[0]);
  std::unique_ptr<v8::Platform> platform = v8::platform::NewDefaultPlatform();
  v8::V8::InitializePlatform(platform.get());
  v8::V8::Initialize();

  v8::Isolate::CreateParams params;
  params.array_buffer_allocator = v8::ArrayBuffer::Allocator::NewDefaultAllocator();
  v8::Isolate* isolate = v8::Isolate::New(params);
  {
    v8::Isolate::Scope isolate_scope(isolate);
    v8::HandleScope handle_scope(isolate);
    v8::Local<v8::Context> ctx = v8::Context::New(isolate);
    v8::Context::Scope context_scope(ctx);

    v8::Local<v8::String> src = v8::String::NewFromUtf8Literal(isolate, "1 + 2");
    v8::Local<v8::Script> script = v8::Script::Compile(ctx, src).ToLocalChecked();
    v8::Local<v8::Value> result = script->Run(ctx).ToLocalChecked();
    v8::String::Utf8Value utf8(isolate, result);
    std::cout << "Result: " << *utf8 << std::endl;  // "Result: 3"
  }

  isolate->Dispose();
  v8::V8::Dispose();
  v8::V8::DisposePlatform();
  delete params.array_buffer_allocator;
  return 0;
}

Prerequisites

Windows

• Visual Studio with C++ workload (MSVC 19.x)
• CMake 3.20+, Ninja, Python 3

Linux

• GCC 13+ or Clang 16+
• CMake 3.20+, Ninja, Python 3

FreeBSD

• Clang 16+ (FreeBSD base clang is sufficient)
• CMake 3.20+, Ninja, Python 3

Getting Started

# Clone and checkout a version branch
git clone https://github.com/polycpp/v8.git
cd v8
git checkout v8-14.3.127.18

# Fetch V8 source and dependencies
python3 fetch_deps.py

# Apply patches (Windows only — no patches needed on Linux/FreeBSD)
# cd v8-src && git apply ../patches/001-msvc-compatibility.patch && cd ..

# Build
cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=Release
cmake --build build

See the version branch README for full build options, test results, and platform-specific details.

License

The build system files in this repo are provided as-is. V8 itself is licensed under the V8 project's BSD-style license.