linux/macos

• gcc/g++ or clang/clang++
• make
• curl
• gunzip

windows

building

linux

the default build of lo runtime links to system libssl and zlib but we build a custom version of libcurl as the default libcurl links to a ton of support libraries we don't need and this slows down startup time. we will likely remove dependency on libcurl at some point (i.e. when we have a robust implementation of fetch in the runtime) but, for now, you will need to install libcurl as follows.

sudo apt install -y libcurl4-openssl-dev libssl-dev zlib1g-dev

gcc/x64

make lo

arm64

make ARCH=arm64 lo

clang

make CC="clang" CXX="clang++" lo

building from a branch/tag

export LO_HOME=$(pwd)
LO_VERSION=main make lo
CC="ccache gcc" CXX="ccache g++" LO_VERSION=main ./lo build runtime runtime/lo

ccache and mold for fast rebuilds

mold -run make C="ccache gcc" CC="ccache g++" lo

macos

the default build of lo runtime depends on libcurl, which is available out of the box on macos. it also depends on openssl, which does not seem to be available as a static library by default.

as such, you will need to install openssl using homebrew or some other mechanism for the default build to succeed.

brew install openssl@3

this will install libssl libs in /opt/homebrew/lib by default. if you need to override this default in the Makefile you can pass the LIB_DIRS argument to make as follows

make LIB_DIRS=/opt/somewhere_else/lib ARCH=arm64 lo

x64

make cleanall lo

arm64

make ARCH=arm64 cleanall lo

windows

• install chocolatey run in powershell terminal as administrator

Set-ExecutionPolicy Bypass -Scope Process -Force; [System.Net.ServicePointManager]::SecurityProtocol = [System.Net.ServicePointManager]::SecurityProtocol -bor 3072; iex ((New-Object System.Net.WebClient).DownloadString('https://community.chocolatey.org/install.ps1'))

https://visualstudio.microsoft.com/downloads/ download and run this https://aka.ms/vs/17/release/vs_BuildTools.exe

choose "Desktop Development with C++"

https://learn.microsoft.com/en-us/cpp/build/msbuild-visual-cpp?view=msvc-170

• install make

choco install make
choco install git

• install visual studio or msbuild
• open an 'x64 Native Tools' command prompt as described here

make cleanall lo.exe test

bumping v8 version

make cleanall
## change v8 version in makefile
make lo

install v8 source

make v8/src