From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 11 Feb 2021 15:02:59 +0000 (+0100)
Subject: sd-common: add new macro for forcing 64bit size for public enums
X-Git-Tag: v248-rc1~63^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9823703ae6ce92c345b6a9bd4a68889bfbc75dd4;p=thirdparty%2Fsystemd.git

sd-common: add new macro for forcing 64bit size for public enums

That's the only way we can retain type-safe enums while being able to
guarantee for stable enum sizes.
---

diff --git a/src/systemd/_sd-common.h b/src/systemd/_sd-common.h
index e3de2ae5629..e121429640b 100644
--- a/src/systemd/_sd-common.h
+++ b/src/systemd/_sd-common.h
@@ -99,4 +99,10 @@ typedef void (*_sd_destroy_t)(void *userdata);
         }                                                       \
         struct _sd_useless_struct_to_allow_trailing_semicolon_
 
+/* The following macro should be used in all public enums, to force 64bit wideness on them, so that we can
+ * freely extend them later on, without breaking compatibility. */
+#define _SD_ENUM_FORCE_S64(id)               \
+        _SD_##id##_INT64_MIN = INT64_MIN,    \
+        _SD_##id##_INT64_MAX = INT64_MAX
+
 #endif