main: refactor BuildInfo code

Simplify and move it into a new file version.go.

3 files changed, 103 insertions, 84 deletions

diff --git a/init_dir.go b/init_dir.go
index e895f00..5ade692 100644
--- a/init_dir.go
+++ b/init_dir.go
@@ -55,8 +55,6 @@ func isDir(dir string) error {
 // In reverse mode, we create .gocryptfs.reverse.conf and the directory does
 // not need to be empty.
 func initDir(args *argContainer) {
-	initGIT()
-
 	var err error
 	if args.reverse {
 		_, err = os.Stat(args.config)
diff --git a/main.go b/main.go
index dad2c73..7facf78 100644
--- a/main.go
+++ b/main.go
@@ -4,12 +4,10 @@
 package main
 
 import (
-	"fmt"
 	"log"
 	"os"
 	"path/filepath"
 	"runtime"
-	"runtime/debug"
 	"strconv"
 	"strings"
 
@@ -21,67 +19,9 @@ import (
 	"github.com/rfjakob/gocryptfs/v2/internal/fido2"
 	"github.com/rfjakob/gocryptfs/v2/internal/readpassword"
 	"github.com/rfjakob/gocryptfs/v2/internal/speed"
-	"github.com/rfjakob/gocryptfs/v2/internal/stupidgcm"
 	"github.com/rfjakob/gocryptfs/v2/internal/tlog"
 )
 
-// GitVersion is the gocryptfs version according to git, set by build.bash
-var GitVersion = "[GitVersion not set - please compile using ./build.bash]"
-
-// GitVersionFuse is the go-fuse library version, set by build.bash
-var GitVersionFuse = "[GitVersionFuse not set - please compile using ./build.bash]"
-
-// BuildDate is a date string like "2017-09-06", set by build.bash
-var BuildDate = "0000-00-00"
-
-// raceDetector is set to true by race.go if we are compiled with "go build -race"
-var raceDetector bool
-
-func initGIT() {
-	bi, ok := debug.ReadBuildInfo()
-	if !ok {
-		return
-	}
-	if strings.HasPrefix(GitVersion, `[`) {
-		GitVersion = bi.Main.Version
-		var gitDate string
-		var gitDirty bool
-		for _, item := range bi.Settings {
-			switch item.Key {
-			case "vcs.revision":
-				GitVersion = item.Value
-			case "vcs.time":
-				gitDate = item.Value
-				gitDate = strings.Map(func(r rune) rune {
-					switch {
-					case r >= '0' && r <= '9':
-						return r
-					default:
-						return -1
-					}
-				}, gitDate)
-			case "vcs.modified":
-				gitDirty, _ = strconv.ParseBool(item.Value)
-			}
-		}
-		if len(gitDate) > 0 {
-			GitVersion = gitDate + "-" + GitVersion
-		}
-		if gitDirty {
-			GitVersion = GitVersion + " (dirty)"
-		}
-	}
-	const fuseModule = `github.com/hanwen/go-fuse/v2`
-
-	if strings.HasPrefix(GitVersionFuse, `[`) {
-		for _, item := range bi.Deps {
-			if item.Path == fuseModule {
-				GitVersionFuse = item.Version
-			}
-		}
-	}
-}
-
 // loadConfig loads the config file `args.config` and decrypts the masterkey,
 // or gets via the `-masterkey` or `-zerokey` command line options, if specified.
 func loadConfig(args *argContainer) (masterkey []byte, cf *configfile.ConfFile, err error) {
@@ -183,28 +123,6 @@ func changePassword(args *argContainer) {
 	tlog.Info.Printf(tlog.ColorGreen + "Password changed." + tlog.ColorReset)
 }
 
-// printVersion prints a version string like this:
-// gocryptfs v1.7-32-gcf99cfd; go-fuse v1.0.0-174-g22a9cb9; 2019-05-12 go1.12 linux/amd64
-func printVersion() {
-	initGIT()
-
-	var tagsSlice []string
-	if stupidgcm.BuiltWithoutOpenssl {
-		tagsSlice = append(tagsSlice, "without_openssl")
-	}
-	tags := ""
-	if tagsSlice != nil {
-		tags = " " + strings.Join(tagsSlice, " ")
-	}
-	built := fmt.Sprintf("%s %s", BuildDate, runtime.Version())
-	if raceDetector {
-		built += " -race"
-	}
-	fmt.Printf("%s %s%s; go-fuse %s; %s %s/%s\n",
-		tlog.ProgramName, GitVersion, tags, GitVersionFuse, built,
-		runtime.GOOS, runtime.GOARCH)
-}
-
 func main() {
 	mxp := runtime.GOMAXPROCS(0)
 	if mxp < 4 && os.Getenv("GOMAXPROCS") == "" {
diff --git a/version.go b/version.go
new file mode 100644
index 0000000..97bf83a
--- /dev/null
+++ b/version.go
@@ -0,0 +1,103 @@
+package main
+
+import (
+	"fmt"
+	"runtime"
+	"runtime/debug"
+	"strconv"
+	"strings"
+
+	"github.com/rfjakob/gocryptfs/v2/internal/stupidgcm"
+	"github.com/rfjakob/gocryptfs/v2/internal/tlog"
+)
+
+const (
+	gitVersionNotSet     = "[GitVersion not set - please compile using ./build.bash]"
+	gitVersionFuseNotSet = "[GitVersionFuse not set - please compile using ./build.bash]"
+	buildDateNotSet      = "0000-00-00"
+)
+
+var (
+	// GitVersion is the gocryptfs version according to git, set by build.bash
+	GitVersion = gitVersionNotSet
+	// GitVersionFuse is the go-fuse library version, set by build.bash
+	GitVersionFuse = gitVersionFuseNotSet
+	// BuildDate is a date string like "2017-09-06", set by build.bash
+	BuildDate = buildDateNotSet
+)
+
+func init() {
+	versionFromBuildInfo()
+}
+
+// raceDetector is set to true by race.go if we are compiled with "go build -race"
+var raceDetector bool
+
+// printVersion prints a version string like this:
+// gocryptfs v1.7-32-gcf99cfd; go-fuse v1.0.0-174-g22a9cb9; 2019-05-12 go1.12 linux/amd64
+func printVersion() {
+	var tagsSlice []string
+	if stupidgcm.BuiltWithoutOpenssl {
+		tagsSlice = append(tagsSlice, "without_openssl")
+	}
+	tags := ""
+	if tagsSlice != nil {
+		tags = " " + strings.Join(tagsSlice, " ")
+	}
+	built := fmt.Sprintf("%s %s", BuildDate, runtime.Version())
+	if raceDetector {
+		built += " -race"
+	}
+	fmt.Printf("%s %s%s; go-fuse %s; %s %s/%s\n",
+		tlog.ProgramName, GitVersion, tags, GitVersionFuse, built,
+		runtime.GOOS, runtime.GOARCH)
+}
+
+// versionFromBuildInfo tries to get some information out of the information baked in
+// by the Go compiler. Does nothing when build.bash was used to build.
+func versionFromBuildInfo() {
+	info, ok := debug.ReadBuildInfo()
+	if !ok {
+		tlog.Debug.Println("versionFromBuildInfo: ReadBuildInfo() failed")
+		return
+	}
+	// Parse BuildSettings
+	var vcsRevision, vcsTime string
+	var vcsModified bool
+	for _, s := range info.Settings {
+		switch s.Key {
+		case "vcs.revision":
+			vcsRevision = s.Value
+		case "vcs.time":
+			vcsTime = s.Value
+		case "vcs.modified":
+			vcsModified, _ = strconv.ParseBool(s.Value)
+		}
+	}
+	// Fill our version strings
+	if GitVersion == gitVersionNotSet {
+		GitVersion = info.Main.Version
+		if GitVersion == "(devel)" && vcsRevision != "" {
+			GitVersion = fmt.Sprintf("vcs.revision=%s", vcsRevision)
+		}
+		if vcsModified {
+			GitVersion += "-dirty"
+		}
+	}
+	if GitVersionFuse == gitVersionFuseNotSet {
+		for _, m := range info.Deps {
+			if m.Path == "github.com/hanwen/go-fuse/v2" {
+				GitVersionFuse = m.Version
+				if m.Replace != nil {
+					GitVersionFuse = m.Replace.Version
+				}
+				break
+			}
+		}
+	}
+	if BuildDate == buildDateNotSet {
+		if vcsTime != "" {
+			BuildDate = fmt.Sprintf("vcs.time=%s", vcsTime)
+		}
+	}
+}