# Cross-Compilation and zig cc — Zig

Source: https://www.geekswithgeeks.com/en/zig/s-cross

> Build for other platforms and use Zig as a C/C++ compiler.

## Every target from one machine

Zig makes **cross-compilation** routine: pass a **target triple** such as `-target aarch64-linux-musl`, `x86_64-windows-gnu` or `aarch64-macos`, or `-Dtarget=` in `zig build`, and the compiler produces a binary for that platform from any host. Zig bundles the libc headers and source (musl, glibc versions, MinGW-w64 for Windows, and others), building the needed libc on demand, so you do not need a separate sysroot or cross toolchain for common targets; macOS targets have limits around system frameworks. Choose `-musl` for fully **static Linux binaries** that run on any distribution. Because of this, **`zig cc`** and **`zig c++`** are widely used as drop-in C/C++ compilers, including by other ecosystems: Go programs with cgo can cross-compile with `CC="zig cc -target ..."`, Rust projects use `cargo-zigbuild`, and some build systems use Zig as a hermetic toolchain. Zig also targets **WebAssembly** (`wasm32-wasi`, `wasm32-freestanding`) and **freestanding** embedded targets such as ARM Cortex-M and RISC-V, where it can run without an operating system. Use `-mcpu` to target specific CPU features.

## Cross-compiling Zig, C and Go

Target triples, static musl binaries and zig cc.

```bash
# Zig program for several targets from one machine
zig build-exe src/main.zig -target x86_64-linux-musl -O ReleaseSafe     # static Linux binary
zig build-exe src/main.zig -target aarch64-linux-gnu.2.31 -O ReleaseSafe   # specific glibc version
zig build-exe src/main.zig -target x86_64-windows-gnu -O ReleaseSmall
zig build -Dtarget=aarch64-macos -Doptimize=ReleaseFast

# WebAssembly
zig build-exe src/main.zig -target wasm32-wasi -O ReleaseSmall

# Zig as a drop-in C compiler
zig cc -target x86_64-windows-gnu hello.c -o hello.exe
zig c++ -target aarch64-linux-musl -O2 server.cpp -o server

# Cross-compiling a Go program that uses cgo
CGO_ENABLED=1 GOOS=linux GOARCH=arm64 CC="zig cc -target aarch64-linux-musl" go build ./cmd/agent

# list supported targets
zig targets | head
```

## musl for portable Linux binaries

A `-musl` target produces a statically linked binary with no dependency on the system's glibc version, which avoids "GLIBC_2.xx not found" errors when deploying to older servers or minimal containers.

**Quiz:** Why can Zig cross-compile C code without installing a separate cross toolchain for common targets?

- [x] It bundles libc headers and sources and builds what the target needs
- [ ] It emulates the target
- [ ] It only supports Linux
- [ ] It downloads Docker images

*Answer:* It bundles libc headers and sources and builds what the target needs. Zig ships libc implementations and headers for many targets.