report wire build version

cmd/wire/main.go

@@ -27,6 +27,7 @@ import (
 	"log"
 	"os"
 	"reflect"
+	"runtime"
 	"sort"
 	"strconv"
 	"strings"
@@ -37,6 +38,8 @@ import (
 	"golang.org/x/tools/go/types/typeutil"
 )
 
+const buildVersion = "0.5.0"
+
 func main() {
 	subcommands.Register(subcommands.CommandsCommand(), "")
 	subcommands.Register(subcommands.FlagsCommand(), "")
@@ -45,6 +48,7 @@ func main() {
 	subcommands.Register(&diffCmd{}, "")
 	subcommands.Register(&genCmd{}, "")
 	subcommands.Register(&showCmd{}, "")
+	subcommands.Register(&versionCmd{}, "")
 	flag.Parse()
 
 	// Initialize the default logger to log to stderr.
@@ -64,6 +68,7 @@ func main() {
 		"diff":     true,
 		"gen":      true,
 		"show":     true,
+		"version":  true,
 	}
 	// Default to running the "gen" command.
 	if args := flag.Args(); len(args) == 0 || !allCmds[args[0]] {
@@ -607,3 +612,22 @@ func logErrors(errs []error) {
 		log.Println(strings.Replace(err.Error(), "\n", "\n\t", -1))
 	}
 }
+
+type versionCmd struct{}
+
+func (*versionCmd) Name() string { return "version" }
+func (*versionCmd) Synopsis() string {
+	return "print Wire version"
+}
+func (*versionCmd) Usage() string {
+	return `version 
+
+Version prints the build information for Go executables.
+
+`
+}
+func (cmd *versionCmd) SetFlags(f *flag.FlagSet) {}
+func (cmd *versionCmd) Execute(ctx context.Context, f *flag.FlagSet, args ...interface{}) subcommands.ExitStatus {
+	fmt.Printf("wire version %s %s/%s", buildVersion, runtime.GOOS, runtime.GOARCH)
+	return subcommands.ExitSuccess
+}