Use debug.ReadBuildInfo for retrieving plugin version

protoc-gen-grpc-gateway/main.go

@@ -49,7 +49,7 @@ func main() {
 	defer glog.Flush()
 
 	if *versionFlag {
-		fmt.Printf("Version %v, commit %v, built at %v\n", version, commit, date)
+		fmt.Printf("Version %v, commit %v, built at %v\n", readVersion(), commit, date)
 		os.Exit(0)
 	}
 

protoc-gen-grpc-gateway/main_go1.18.go

@@ -0,0 +1,13 @@
+//go:build go1.18
+
+package main
+
+import "runtime/debug"
+
+func readVersion() string {
+	v, ok := debug.ReadBuildInfo()
+	if !ok {
+		return version
+	}
+	return v.Main.Version
+}

protoc-gen-grpc-gateway/main_go_less1.18.go

@@ -0,0 +1,7 @@
+//go:build !go1.18
+
+package main
+
+func readVersion() string {
+	return version
+}

protoc-gen-openapiv2/main.go

@@ -56,7 +56,7 @@ func main() {
 	defer glog.Flush()
 
 	if *versionFlag {
-		fmt.Printf("Version %v, commit %v, built at %v\n", version, commit, date)
+		fmt.Printf("Version %v, commit %v, built at %v\n", readVersion(), commit, date)
 		os.Exit(0)
 	}
 

protoc-gen-openapiv2/main_go1.18.go

@@ -0,0 +1,13 @@
+//go:build go1.18
+
+package main
+
+import "runtime/debug"
+
+func readVersion() string {
+	v, ok := debug.ReadBuildInfo()
+	if !ok {
+		return version
+	}
+	return v.Main.Version
+}

protoc-gen-openapiv2/main_go_less1.18.go

@@ -0,0 +1,7 @@
+//go:build !go1.18
+
+package main
+
+func readVersion() string {
+	return version
+}