The patch titled
Subject: compiler.h: move __is_constexpr() to compiler.h
has been added to the -mm mm-nonmm-unstable branch. Its filename is
compilerh-move-__is_constexpr-to-compilerh.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/compilerh-move-__is_constexpr-to-compilerh.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: David Laight <David.Laight@xxxxxxxxxx>
Subject: compiler.h: move __is_constexpr() to compiler.h
Date: Mon, 2 Oct 2023 14:34:05 +0000
Prior to f747e6667ebb2 __is_constexpr() was in its only user minmax.h.
That commit moved it to const.h - but that file just defined ULL(x) and
UL(x) so that constants can be defined for .S and .c files.
So apart from the word 'const' it wasn't really a good location. Instead
move the definition to compiler.h just before the similar
is_signed_type() and is_unsigned_type().
(Which were moved there by dcf8e5633e2e6) This may not be a good long-term
home, but the three definitions belong together.
This makes it possible to use __is_constexpr() inside is_signed_type() so
that the result is constant integer expression for pointer types. In
particular (void *)1 isn't constant enough.
Link: https://lkml.kernel.org/r/6d2b584e26544ee6a0810e494352d432@xxxxxxxxxxxxxxxx
Signed-off-by: David Laight <david.laight@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/compiler.h | 8 ++++++++
include/linux/const.h | 8 --------
tools/include/linux/const.h | 8 --------
3 files changed, 8 insertions(+), 16 deletions(-)
--- a/include/linux/compiler.h~compilerh-move-__is_constexpr-to-compilerh
+++ a/include/linux/compiler.h
@@ -228,6 +228,14 @@ static inline void *offset_to_ptr(const
#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
/*
+ * This returns a constant expression while determining if an argument is
+ * a constant expression, most importantly without evaluating the argument.
+ * Glory to Martin Uecker <Martin.Uecker@xxxxxxxxxxxxxxxxxxxxx>
+ */
+#define __is_constexpr(x) \
+ (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8)))
+
+/*
* Whether 'type' is a signed type or an unsigned type. Supports scalar types,
* bool and also pointer types.
*/
--- a/include/linux/const.h~compilerh-move-__is_constexpr-to-compilerh
+++ a/include/linux/const.h
@@ -3,12 +3,4 @@
#include <vdso/const.h>
-/*
- * This returns a constant expression while determining if an argument is
- * a constant expression, most importantly without evaluating the argument.
- * Glory to Martin Uecker <Martin.Uecker@xxxxxxxxxxxxxxxxxxxxx>
- */
-#define __is_constexpr(x) \
- (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8)))
-
#endif /* _LINUX_CONST_H */
--- a/tools/include/linux/const.h~compilerh-move-__is_constexpr-to-compilerh
+++ a/tools/include/linux/const.h
@@ -3,12 +3,4 @@
#include <vdso/const.h>
-/*
- * This returns a constant expression while determining if an argument is
- * a constant expression, most importantly without evaluating the argument.
- * Glory to Martin Uecker <Martin.Uecker@xxxxxxxxxxxxxxxxxxxxx>
- */
-#define __is_constexpr(x) \
- (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8)))
-
#endif /* _LINUX_CONST_H */
_
Patches currently in -mm which might be from David.Laight@xxxxxxxxxx are
minmax-add-umina-b-and-umaxa-b.patch
minmax-allow-min-max-clamp-if-the-arguments-have-the-same-signedness.patch
minmax-fix-indentation-of-__cmp_once-and-__clamp_once.patch
minmax-allow-comparisons-of-int-against-unsigned-char-short.patch
minmax-relax-check-to-allow-comparison-between-unsigned-arguments-and-signed-constants.patch
compilerh-move-__is_constexpr-to-compilerh.patch
