jedi.sh#> ZGo (part 1), Calling Zig from Go

package main

import "fmt"

// #cgo CFLAGS: -I.
// #cgo LDFLAGS: -L. -lzgo
// #include ❬zgo.h❭
import "C"

func main() {
   fmt.Printf("Invoking zig library!\n")
   fmt.Println("Done ", C.x(10))
}

const std = @import("std");

pub export fn x(y: c_int) c_int {
    return y+2;
}

const std = @import("std");
const Builder = std.build.Builder;
const builtin = std.builtin;

pub fn build(b: *Builder) void {
    const mode = b.standardReleaseOptions();
    const lib = b.addStaticLibrary("zgo", "zgo.zig");
    lib.bundle_compiler_rt = true;
    lib.use_stage1 = false;
    lib.emit_h = true;
    lib.emit_bin = .{ .emit_to = "libzgo.a"};
    lib.setBuildMode(mode);
    lib.install();

    const go = build_go(b);
    const make_step = b.step("go", "Make go executable");
    make_step.dependOn(&go.step);
}

fn build_go(b: *std.build.Builder) *std.build.RunStep {

    const go = b.addSystemCommand(
        &[_][]const u8{
            "go",
            "build",
            "-ldflags", "-linkmode external -extldflags -static",
            "bridge.go",
        },
    );
    return go;
}

Running zig build && zig build go will compile the executable.

static:
       zig build-lib -fno-stage1 -femit-h zgo.zig
       go build -ldflags "-linkmode external -extldflags -static" bridge.go

dynamic:
       zig build-lib -dynamic -fno-stage1 -femit-h zgo.zig
       go build -ldflags "-linkmode external -extldflags -dynamic" bridge.go

Calling Zig!

linux@solar ~/P/zgo> ./bridge
   Invoking zig library!
   Done  12

Thoughts:

*************

Zig makes a good companion to Go in a number of regards. The integrated build system has been one of my favorite parts of the Zig experience. I rarely opt for writing Makefiles when I can write a build.zig. The portability of the Zig compiler and cross-target capabilities make for an ideal part of any build pipeline. Zig is a useful tool to interop with existing libraries, squeezing a bit more performance out of a hot path, or maintaining builds of exisiting projects.