gocompiler

The Go compiler as a package

# go1.22.0
go get github.com/bir3/gocompiler@v0.9.2202

Example

package main

import (
	"fmt"
	"log"
	"os"

	"github.com/bir3/gocompiler"
)

var goCodeStr string = `
package main

import "fmt"

func main() {
	fmt.Println("This code was compiled standalone")
}
`

func main() {

	// the go toolchain is built into the executable and must be given a chance to run
	// => avoid side effects in init() and global variable initialization
	//    as they will occur multiple times during compilation
	if gocompiler.IsRunToolchainRequest() {
		gocompiler.RunToolchain()
		return
	}

	err := os.WriteFile("temp.go", []byte(goCodeStr), 0644)
	if err != nil {
		log.Fatal(err)
	}

	result, err := gocompiler.Run("go", "run", "temp.go")
	fmt.Fprintf(os.Stdout, "%s", result.Stdout)
	fmt.Fprintf(os.Stderr, "%s", result.Stderr)
	if err != nil {
		log.Fatal(err)
	}
	os.Remove("temp.go")
}

Standard library

The standard library is embedded and is extracted on first run to standard config location;

• $HOME/.config/bir3-gocompiler (linux)
• $HOME/Library/Application Support/bir3-gocompiler (mac)

Private Go build cache

To avoid interfering with the standard Go toolchain build cache, the package has a private Go build cache;

• $HOME/.cache/bir3-gocompiler (linux)
• $HOME/Library/Caches/bir3-gocompiler (mac)

Limitations

• avoid side effects in init() and global variable initializations

Reason: Your executable will serve two purposes:

• run your application
• run the Go compiler toolchain via gocompiler.RunToolchain()

Side effects in init() and global variable initializations occur every time the executable is started.
The embedded Go toolchain will repeatedly start the executable during compilation to compile Go source code.
This means that global side effects like opening a http port, writing to a file or connecting to a database is likely to cause problems.

gocompiler as a package vs. the official Go toolchain

	"github.com/bir3/gocompiler"	official go toolchain
Download size	26 MB (gzip of executable)	62 MB (gzip tarfile)
Size on disk	91 MB	237 MB
Compile speed	12.9 sec	12.4 sec	macbook M1, go build -a

Note that this package is only focused on compiling Go source code into an executable, while the official Go toolchain provides many more tools.

Acknowledgments

• The Go Authors. https://github.com/golang/go
• Klaus Post, zstd decompression: https://github.com/klauspost/compress