[PATCH v6 6/7] test_bits: add tests for GENMASK_U*()

[Vincent Mailhol via B4 Relay]

From: Lucas De Marchi <lucas.demarchi at intel.com>

Add some additional tests in lib/test_bits.c to cover the
expected/non-expected values of the fixed-type GENMASK_U*() macros.

Also check that the result value matches the expected type. Since
those are known at build time, use static_assert() instead of normal
kunit tests.

Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent at wanadoo.fr>
---
Changelog:

  v5 -> v6:

    - No changes.

  v4 -> v5:

    - Revert v4 change. GENMASK_U8()/GENMASK_U16() are now back to
      u8/u16.

  v3 -> v4:

    - Adjust the type of GENMASK_U8()/GENMASK_U16() from u8/u16 to
      unsigned int.

    - Reorder the tests to match the order in which the macros are
      declared in bits.h.
---
 lib/test_bits.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/lib/test_bits.c b/lib/test_bits.c
index b0c29b01fb30cbcc759ac1e7106457b18bcd73a0..87112d1895194da33c0ffdf0a6fe6df43ce6b1e7 100644
--- a/lib/test_bits.c
+++ b/lib/test_bits.c
@@ -5,6 +5,16 @@
 
 #include <kunit/test.h>
 #include <linux/bits.h>
+#include <linux/types.h>
+
+#define assert_type(t, x) _Generic(x, t: x, default: 0)
+
+static_assert(assert_type(unsigned long, GENMASK(31, 0)) == U32_MAX);
+static_assert(assert_type(unsigned long long, GENMASK_ULL(63, 0)) == U64_MAX);
+static_assert(assert_type(u8, GENMASK_U8(7, 0)) == U8_MAX);
+static_assert(assert_type(u16, GENMASK_U16(15, 0)) == U16_MAX);
+static_assert(assert_type(u32, GENMASK_U32(31, 0)) == U32_MAX);
+static_assert(assert_type(u64, GENMASK_U64(63, 0)) == U64_MAX);
 
 /* FIXME: add a test case written in asm for GENMASK() and GENMASK_ULL() */
 
@@ -31,11 +41,21 @@ static void genmask_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, 6ul, GENMASK(2, 1));
 	KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, GENMASK(31, 0));
 
+	KUNIT_EXPECT_EQ(test, 1u, GENMASK_U8(0, 0));
+	KUNIT_EXPECT_EQ(test, 3u, GENMASK_U16(1, 0));
+	KUNIT_EXPECT_EQ(test, 0x10000, GENMASK_U32(16, 16));
+
 #ifdef TEST_GENMASK_FAILURES
 	/* these should fail compilation */
 	GENMASK(0, 1);
 	GENMASK(0, 10);
 	GENMASK(9, 10);
+
+	GENMASK_U32(0, 31);
+	GENMASK_U64(64, 0);
+	GENMASK_U32(32, 0);
+	GENMASK_U16(16, 0);
+	GENMASK_U8(8, 0);
 #endif
 
 

-- 
2.45.3