minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()

Use BUILD_BUG_ON_MSG(statically_true(ulo > uhi), ...) for the sanity check
of the bounds in clamp().  Gives better error coverage and one less
expansion of the arguments.

Link: https://lkml.kernel.org/r/34d53778977747f19cce2abb287bb3e6@AcuMS.aculab.com
Signed-off-by: David Laight <david.laight@aculab.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/minmax.h b/include/linux/minmax.h
index 6f7ea669d305cb73762de280da9761052baedfc4..91aa1b90c1bb65aa8886b565f23d28620a9e98b1 100644 (file)
--- a/include/linux/minmax.h
+++ b/include/linux/minmax.h
@@ -106,8 +106,7 @@
        __auto_type uval = (val);                                               \
        __auto_type ulo = (lo);                                                 \
        __auto_type uhi = (hi);                                                 \
-       static_assert(__builtin_choose_expr(__is_constexpr((lo) > (hi)),        \
-                       (lo) <= (hi), true),                                    \
+       BUILD_BUG_ON_MSG(statically_true(ulo > uhi),                            \
                "clamp() low limit " #lo " greater than high limit " #hi);      \
        BUILD_BUG_ON_MSG(!__types_ok3(uval, ulo, uhi),                          \
                "clamp("#val", "#lo", "#hi") signedness error");                \