Get right logrus package name

entry.go

@@ -185,7 +185,7 @@ func getCaller() *runtime.Frame {
 	callerInitOnce.Do(func() {
 		pcs := make([]uintptr, 2)
 		_ = runtime.Callers(0, pcs)
-		logrusPackage = getPackageName(runtime.FuncForPC(pcs[1]).Name())
+		logrusPackage = getPackageName(funcName(pcs))
 
 		// now that we have the cache, we can skip a minimum count of known-logrus functions
 		// XXX this is dubious, the number of frames may vary

versions_go1_14.go

@@ -0,0 +1,10 @@
+// +build go1.14
+
+package logrus
+
+import "runtime"
+
+// funcName returns the function name that logrus calls
+func funcName(pcs []uintptr) string {
+	return runtime.FuncForPC(pcs[0]).Name()
+}

versions_others.go

@@ -0,0 +1,10 @@
+// +build !go1.14
+
+package logrus
+
+import "runtime"
+
+// funcName returns the function name that logrus calls
+func funcName(pcs []uintptr) string {
+	return runtime.FuncForPC(pcs[1]).Name()
+}