Print Go's SSA form, much like ssadump but with concrete types

ssadump.go

package main

import (
	"flag"
	"fmt"
	"go/build"
	"go/types"
	"os"

	"golang.org/x/tools/go/loader"
	"golang.org/x/tools/go/ssa"
	"golang.org/x/tools/go/ssa/ssautil"
)

func main() {
	if err := doMain(); err != nil {
		fmt.Fprintf(os.Stderr, "ssadump: %s\n", err)
		os.Exit(1)
	}
}

func doMain() error {
	flag.Parse()

	args := flag.Args()
	if len(args) == 0 {
		fmt.Fprintln(os.Stderr, "need packages")
		os.Exit(1)
	}

	conf := loader.Config{Build: &build.Default}

	if _, err := conf.FromArgs(args, false); err != nil {
		return err
	}

	goprog, err := conf.Load()
	if err != nil {
		return err
	}

	ssaprog := ssautil.CreateProgram(goprog, 0)
	ssaprog.Build()

	initial := goprog.InitialPackages()
	initialMap := make(map[*types.Package]struct{}, len(initial))
	for _, pi := range initial {
		initialMap[pi.Pkg] = struct{}{}
	}

	for fn, _ := range ssautil.AllFunctions(ssaprog) {
		if fn.Pkg == nil {
			continue
		}
		if _, ok := initialMap[fn.Pkg.Pkg]; !ok {
			continue
		}

		fmt.Println(fn.String())
		for _, b := range fn.Blocks {
			fmt.Printf("%s:\n", b.String())
			for _, i := range b.Instrs {
				if v, ok := i.(ssa.Value); ok {
					fmt.Printf("\t[%-20T] %s = %s\n", i, v.Name(), i)
				} else {
					fmt.Printf("\t[%-20T] %s\n", i, i)
				}
			}
		}
	}

	return nil
}