[PATCH v2 1/2] selftests: Provide local define of min() and max()

Mahmoud Maatuq
2023-08-24T20:26:39Z

to avoid manual calculation of min and max values
and fix coccinelle warnings such WARNING opportunity for min()/max()
adding one common definition that could be used in multiple files
under selftests.
there are also some defines for min/max scattered locally inside sources
under selftests.
this also prepares for cleaning up those redundant defines and include
kselftest.h instead.

Signed-off-by: Mahmoud Maatuq <mahmoudmatook.mm@gmail.com>
Suggested-by: David Laight <David.Laight@aculab.com>
---
changes in v2:
redefine min/max in a more strict way to avoid
signedness mismatch and multiple evaluation.
is_signed_type() moved from selftests/kselftest_harness.h
to selftests/kselftest.h.
---
tools/testing/selftests/kselftest.h | 24 +++++++++++++++++++++
tools/testing/selftests/kselftest_harness.h | 2 --
2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/kselftest.h b/tools/testing/selftests/kselftest.h
index 829be379545a..93d029471cc9 100644
--- a/tools/testing/selftests/kselftest.h
+++ b/tools/testing/selftests/kselftest.h
@@ -55,6 +55,30 @@
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
#endif

+#ifndef is_signed_type
+#define is_signed_type(var) (!!(((__typeof__(var))(-1)) < (__typeof__(var))1))
+#endif
+
+#ifndef min
+#define min(x, y) ({ \
+ _Static_assert(is_signed_type(typeof(x)) == is_signed_type(typeof(y)), \
+ "min: signedness mismatch"); \
+ typeof(x) _x = (x); \
+ typeof(y) _y = (y); \
+ _x < _y ? _x : _y; \
+})
+#endif
+
+#ifndef max
+#define max(x, y) ({ \
+ _Static_assert(is_signed_type(typeof(x)) == is_signed_type(typeof(y)), \
+ "max: signedness mismatch"); \
+ typeof(x) _x = (x); \
+ typeof(y) _y = (y); \
+ _x > _y ? _x : _y; \
+})
+#endif
+
/*
* gcc cpuid.h provides __cpuid_count() since v4.4.
* Clang/LLVM cpuid.h provides __cpuid_count() since v3.4.0.
diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h
index 5fd49ad0c696..e4e310815226 100644
--- a/tools/testing/selftests/kselftest_harness.h
+++ b/tools/testing/selftests/kselftest_harness.h
@@ -699,8 +699,6 @@
if (_metadata->passed && _metadata->step < 253) \
_metadata->step++;

-#define is_signed_type(var) (!!(((__typeof__(var))(-1)) < (__typeof__(var))1))
-
#define __EXPECT(_expected, _expected_str, _seen, _seen_str, _t, _assert) do { \
/* Avoid multiple evaluation of the cases */ \
__typeof__(_expected) __exp = (_expected); \
--
2.34.1