main: refactor BuildInfo code

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

1 files changed, 103 insertions, 0 deletions

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)
+		}
+	}
+}