Generate version during compilation

cmd/internal/build_shared/tag.go

@@ -0,0 +1,18 @@
+package build_shared
+
+import (
+	"github.com/sagernet/sing/common"
+)
+
+func ReadTag() (string, error) {
+	currentTag, err := common.Exec("git", "describe", "--tags").ReadOutput()
+	if err != nil {
+		return currentTag, err
+	}
+	currentTagRev, _ := common.Exec("git", "describe", "--tags", "--abbrev=0").ReadOutput()
+	if currentTagRev == currentTag {
+		return currentTag[1:], nil
+	}
+	shortCommit, _ := common.Exec("git", "rev-parse", "--short", "HEAD").ReadOutput()
+	return currentTagRev[1:] + "-" + shortCommit, nil
+}