Introduce API compatibility macros

[lttng-ust.git] / include / lttng / ust-api-compat.h

diff --git a/include/lttng/ust-api-compat.h b/include/lttng/ust-api-compat.h
new file mode 100644 (file)
index 0000000..af9c272
--- /dev/null
+++ b/include/lttng/ust-api-compat.h
@@ -0,0 +1,31 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2021 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * LTTng-UST API compatibility header
+ */
+
+#ifndef _LTTNG_UST_API_COMPAT_H
+#define _LTTNG_UST_API_COMPAT_H
+
+/*
+ * In order to disable compatibility API for a range of soname major
+ * versions, define LTTNG_UST_COMPAT_API_VERSION to the oldest major
+ * version API for which to provide compatibility.
+ *
+ * If LTTNG_UST_COMPAT_API_VERSION is undefined, API compatibility for
+ * all API versions is provided.
+ * If LTTNG_UST_COMPAT_API_VERSION is defined to N, API compatibility
+ * for soname N or higher is provided, leaving out (not compiling)
+ * compatibility for soname lower than N.
+ */
+
+#ifndef LTTNG_UST_COMPAT_API_VERSION
+#define LTTNG_UST_COMPAT_API_VERSION 0
+#endif
+
+#define LTTNG_UST_COMPAT_API(major)    \
+       (LTTNG_UST_COMPAT_API_VERSION <= (major))
+
+#endif /* _LTTNG_UST_API_COMPAT_H */