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

From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: LKML <linux-kernel@vger.kernel.org>
Cc: DRI Development <dri-devel@lists.freedesktop.org>,
	Intel Graphics Development <intel-gfx@lists.freedesktop.org>,
	Daniel Vetter <daniel.vetter@ffwll.ch>,
	Daniel Vetter <daniel.vetter@intel.com>,
	Gustavo Padovan <gustavo@padovan.org>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Sean Paul <seanpaul@chromium.org>,
	David Airlie <airlied@linux.ie>,
	Andrew Morton <akpm@linux-foundation.org>,
	Kees Cook <keescook@chromium.org>, Ingo Molnar <mingo@kernel.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	NeilBrown <neilb@suse.com>, Wei Wang <wvw@google.com>,
	Stefan Agner <stefan@agner.ch>, Andrei Vagin <avagin@openvz.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Yisheng Xie <ysxie@foxmail.com>
Subject: [PATCH 01/12] kernel.h: Add for_each_if()
Date: Mon,  9 Jul 2018 10:36:39 +0200	[thread overview]
Message-ID: <20180709083650.23549-1-daniel.vetter@ffwll.ch> (raw)

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@intel.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: NeilBrown <neilb@suse.com>
Cc: Wei Wang <wvw@google.com>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Andrei Vagin <avagin@openvz.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Yisheng Xie <ysxie@foxmail.com>
---
 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

