node-pointer-compression-builds

Custom builds of Node.js with V8 pointer compression enabled. Pointer compression shrinks V8 heap pointers from 8 bytes to 4 bytes, reducing heap memory usage significantly for applications with many heap-allocated objects.

Prebuilt binaries for all platforms are published as GitHub Releases. Each release is triggered manually via the "Build Node.js from Source" Actions workflow.

Build flags

All builds are configured with:

Flag	Effect
--experimental-enable-pointer-compression	Compress V8 heap pointers from 8 → 4 bytes
--experimental-pointer-compression-shared-cage	Share the compression cage across Isolates in the same process
--without-siphash	Use a simpler alternative to SipHash for V8 hash seeds

Platforms

Platform	Architecture	Runner
Linux	x64	ubuntu-22.04
Linux	arm64	ubuntu-22.04-arm
macOS	x64	macos-15-intel
macOS	arm64	macos-15 (Apple Silicon)
Windows	x64	windows-2025
Windows	arm64	windows-11-arm

Patches

The builds apply a small set of patches, sourced from the Electron project, on top of the Node.js source tree, stored in patches/. These are necessary to make the pointer-compression build work:

• support_v8_sandboxed_pointers — refactors several allocators to allocate within the V8 memory cage, required when V8_SANDBOXED_POINTERS is active.
• random_build_flag_changes — enables the V8 sandbox (v8_enable_sandbox) when pointer compression is on, matching V8's expectations.
• api_remove_deprecated_getisolate — replaces a deprecated context->GetIsolate() call with Isolate::GetCurrent(), required by newer V8.

Adding a new patch

cd node-src
vim some/code/file.cc
git commit
../script/git-export-patches -o ../patches

Note

git-export-patches ignores uncommitted files — create a commit first. The commit subject line becomes the patch file name; the body should explain why the patch exists.

Re-exporting patches may cause shasums in unrelated patches to change. This is harmless — include those changes in your PR anyway to keep things consistent for others.

Building locally

./build.sh

This clones Node.js at the pinned tag, applies all patches, configures with the pointer-compression flags, and installs the result into ./release/.