Cross-compiler for CGO-based Golang projects using zig cc

xcgo-zig is, at the moment, a very basic proof-of-concept of a wrapper to make cross-compiling CGO binaries using zig cc easier.

It mainly eases this by inspecting GOOS and GOARCH and setting the appropriate zig cc targets.

So instead of running:

CGO_ENABLED=1 GOOS=linux GOARCH=amd64 CC="zig cc -target x86_64-linux" CXX="zig c++ -target x86_64-linux" go build main.go

One can use xcgo-zig as a wrapper for go and simply run:

GOOS=linux GOARCH=amd64 xcgo-zig build main.go

Behind the scenes, xcgo-zig will build and inject the correct CC and CXX environment variables:

$ GOOS=linux GOARCH=amd64 xcgo-zig build main.go
xcgo-zig: Running `go build main.go` with:
xcgo-zig: GOOS=linux
xcgo-zig: GOARCH=amd64
xcgo-zig: CC=/opt/homebrew/bin/zig cc -target x86_64-linux-musl
xcgo-zig: CXX=/opt/homebrew/bin/zig c++ -target x86_64-linux-musl

By default, xcgo-zig will find and use the first go available in your $PATH. However, this behavior can be changed with GO= environment variable:

$ GO=gotip xcgo-zig version
xcgo-zig: Running `gotip version` with:
xcgo-zig: GOOS=
xcgo-zig: GOARCH=
xcgo-zig: CC=/opt/homebrew/bin/zig cc
xcgo-zig: CXX=/opt/homebrew/bin/zig c++
go version devel go1.21-26f2569 Tue May 23 21:46:00 2023 +0000 darwin/arm64

So far this has only been tested cross-compiling from an M1 macOS machine to linux, which required:

• Golang 1.20.3 or higher (due to golang/go#58935)
• Zig 0.11 or higher (I used 0.11.0-dev.3220+447a30299)
  • zig must be found in your $PATH
  • In the future, I'd like to support downloading and extracting a known-good version of zig to use instead.