diff --git a/lib/decoding/osmocom/core/defs.h b/lib/decoding/osmocom/core/defs.h
new file mode 100644
index 0000000..5e5aa90
--- /dev/null
+++ b/lib/decoding/osmocom/core/defs.h
@@ -0,0 +1,53 @@
+/*! \file defs.h
+ *  General definitions that are meant to be included from header files.
+ */
+
+#pragma once
+
+/*! \defgroup utils General-purpose utility functions
+ *  @{
+ * \file defs.h */
+
+/*! Check for gcc and version.
+ *
+ * \note Albeit glibc provides a features.h file that contains a similar
+ *       definition (__GNUC_PREREQ), this definition has been copied from there
+ *       to have it available with other libraries, too.
+ *
+ * \return != 0 iff gcc is used and it's version is at least maj.min.
+ */
+#if defined __GNUC__ && defined __GNUC_MINOR__
+# define OSMO_GNUC_PREREQ(maj, min) \
+	((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
+#else
+# define OSMO_GNUC_PREREQ(maj, min) 0
+#endif
+
+/*! Set the deprecated attribute with a message.
+ */
+#if defined(__clang__)
+# define _OSMO_HAS_ATTRIBUTE_DEPRECATED __has_attribute(deprecated)
+# define _OSMO_HAS_ATTRIBUTE_DEPRECATED_WITH_MESSAGE __has_extension(attribute_deprecated_with_message)
+#elif defined(__GNUC__)
+# define _OSMO_HAS_ATTRIBUTE_DEPRECATED 1
+# define _OSMO_HAS_ATTRIBUTE_DEPRECATED_WITH_MESSAGE OSMO_GNUC_PREREQ(4,5)
+#endif
+
+#if _OSMO_HAS_ATTRIBUTE_DEPRECATED_WITH_MESSAGE
+# define OSMO_DEPRECATED(text)  __attribute__((__deprecated__(text)))
+#elif _OSMO_HAS_ATTRIBUTE_DEPRECATED
+# define OSMO_DEPRECATED(text)  __attribute__((__deprecated__))
+#else
+# define OSMO_DEPRECATED(text)
+#endif
+
+#if BUILDING_LIBOSMOCORE
+# define OSMO_DEPRECATED_OUTSIDE_LIBOSMOCORE
+#else
+# define OSMO_DEPRECATED_OUTSIDE_LIBOSMOCORE OSMO_DEPRECATED("For internal use inside libosmocore only.")
+#endif
+
+#undef _OSMO_HAS_ATTRIBUTE_DEPRECATED_WITH_MESSAGE
+#undef _OSMO_HAS_ATTRIBUTE_DEPRECATED
+
+/*! @} */