[PATCH 01/12] kernel.h: Add for_each_if()

From: Daniel Vetter
Date: Mon Jul 09 2018 - 04:37:04 EST


To avoid compilers complainig about ambigious else blocks when putting
an if condition into a for_each macro one needs to invert the
condition and add a dummy else. We have a nice little convenience
macro for that in drm headers, let's move it out. Subsequent patches
will roll it out to other places.

Motivated by a discussion with Andy and Yisheng, who want to add
another for_each_macro which would benefit from for_each_if() instead
of hand-rolling it.

Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Cc: Gustavo Padovan <gustavo@xxxxxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Sean Paul <seanpaul@xxxxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: NeilBrown <neilb@xxxxxxxx>
Cc: Wei Wang <wvw@xxxxxxxxxx>
Cc: Stefan Agner <stefan@xxxxxxxx>
Cc: Andrei Vagin <avagin@xxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Yisheng Xie <ysxie@xxxxxxxxxxx>
---
include/drm/drmP.h | 3 ---
include/linux/kernel.h | 3 +++
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index f7a19c2a7a80..05350424a4d3 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -110,7 +110,4 @@ static inline bool drm_can_sleep(void)
return true;
}

-/* helper for handling conditionals in various for_each macros */
-#define for_each_if(condition) if (!(condition)) {} else
-
#endif
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 941dc0a5a877..4cb95ab9a5bc 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -71,6 +71,9 @@
*/
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))

+/* helper for handling conditionals in various for_each macros */
+#define for_each_if(condition) if (!(condition)) {} else
+
#define u64_to_user_ptr(x) ( \
{ \
typecheck(u64, x); \
--
2.18.0