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  3. [PATCH next 00/14] bits: De-bloat expansion of GENMASK()
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[PATCH next 13/14] test_bits: Change all the tests to be compile-time tests

david.laight.linux@gmail.com posted 14 patches 2 weeks, 3 days ago
[PATCH next 13/14] test_bits: Change all the tests to be compile-time tests
Posted by david.laight.linux@gmail.com 2 weeks, 3 days ago 
From: David Laight <david.laight.linux@gmail.com>

Since all the GENMASK() values are compile-time constants they can
be tested with BUILD_BUG_ON() rather than KUNIT_EXPECT_EQ().

Signed-off-by: David Laight <david.laight.linux@gmail.com>
---
 lib/tests/test_bits.c | 90 +++++++++++++++++++++----------------------
 1 file changed, 45 insertions(+), 45 deletions(-)

diff --git a/lib/tests/test_bits.c b/lib/tests/test_bits.c
index 36eb4661e78b..4d3a895f490c 100644
--- a/lib/tests/test_bits.c
+++ b/lib/tests/test_bits.c
@@ -32,30 +32,30 @@ static_assert(assert_type(u64, GENMASK_U64(63, 0)) == U64_MAX);
 
 static void __genmask_test(struct kunit *test)
 {
-	KUNIT_EXPECT_EQ(test, 1ul, __GENMASK(0, 0));
-	KUNIT_EXPECT_EQ(test, 3ul, __GENMASK(1, 0));
-	KUNIT_EXPECT_EQ(test, 6ul, __GENMASK(2, 1));
-	KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, __GENMASK(31, 0));
+	BUILD_BUG_ON(__GENMASK(0, 0) != 1ul);
+	BUILD_BUG_ON(__GENMASK(1, 0) != 3ul);
+	BUILD_BUG_ON(__GENMASK(2, 1) != 6ul);
+	BUILD_BUG_ON(__GENMASK(31, 0) != 0xFFFFFFFFul);
 }
 
 static void __genmask_ull_test(struct kunit *test)
 {
-	KUNIT_EXPECT_EQ(test, 1ull, __GENMASK_ULL(0, 0));
-	KUNIT_EXPECT_EQ(test, 3ull, __GENMASK_ULL(1, 0));
-	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, __GENMASK_ULL(39, 21));
-	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, __GENMASK_ULL(63, 0));
+	BUILD_BUG_ON(__GENMASK_ULL(0, 0) != 1ull);
+	BUILD_BUG_ON(__GENMASK_ULL(1, 0) != 3ull);
+	BUILD_BUG_ON(__GENMASK_ULL(39, 21) != 0x000000ffffe00000ull);
+	BUILD_BUG_ON(__GENMASK_ULL(63, 0) != 0xffffffffffffffffull);
 }
 
 static void genmask_test(struct kunit *test)
 {
-	KUNIT_EXPECT_EQ(test, 1ul, GENMASK(0, 0));
-	KUNIT_EXPECT_EQ(test, 3ul, GENMASK(1, 0));
-	KUNIT_EXPECT_EQ(test, 6ul, GENMASK(2, 1));
-	KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, GENMASK(31, 0));
+	BUILD_BUG_ON(GENMASK(0, 0) != 1ul);
+	BUILD_BUG_ON(GENMASK(1, 0) != 3ul);
+	BUILD_BUG_ON(GENMASK(2, 1) != 6ul);
+	BUILD_BUG_ON(GENMASK(31, 0) != 0xFFFFFFFFul);
 
-	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));
+	BUILD_BUG_ON(GENMASK_U8(0, 0) != 1u);
+	BUILD_BUG_ON(GENMASK_U16(1, 0) != 3u);
+	BUILD_BUG_ON(GENMASK_U32(16, 16) != 0x10000);
 
 #ifdef TEST_GENMASK_FAILURES
 	/* these should fail compilation */
@@ -75,10 +75,10 @@ static void genmask_test(struct kunit *test)
 
 static void genmask_ull_test(struct kunit *test)
 {
-	KUNIT_EXPECT_EQ(test, 1ull, GENMASK_ULL(0, 0));
-	KUNIT_EXPECT_EQ(test, 3ull, GENMASK_ULL(1, 0));
-	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, GENMASK_ULL(39, 21));
-	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_ULL(63, 0));
+	BUILD_BUG_ON(GENMASK_ULL(0, 0) != 1ull);
+	BUILD_BUG_ON(GENMASK_ULL(1, 0) != 3ull);
+	BUILD_BUG_ON(GENMASK_ULL(39, 21) != 0x000000ffffe00000ull);
+	BUILD_BUG_ON(GENMASK_ULL(63, 0) != 0xffffffffffffffffull);
 
 #ifdef TEST_GENMASK_FAILURES
 	/* these should fail compilation */
@@ -92,23 +92,23 @@ static void genmask_u128_test(struct kunit *test)
 {
 #ifdef CONFIG_ARCH_SUPPORTS_INT128
 	/* Below 64 bit masks */
-	KUNIT_EXPECT_EQ(test, 0x0000000000000001ull, GENMASK_U128(0, 0));
-	KUNIT_EXPECT_EQ(test, 0x0000000000000003ull, GENMASK_U128(1, 0));
-	KUNIT_EXPECT_EQ(test, 0x0000000000000006ull, GENMASK_U128(2, 1));
-	KUNIT_EXPECT_EQ(test, 0x00000000ffffffffull, GENMASK_U128(31, 0));
-	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, GENMASK_U128(39, 21));
-	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(63, 0));
+	BUILD_BUG_ON(GENMASK_U128(0, 0) != 0x0000000000000001ull);
+	BUILD_BUG_ON(GENMASK_U128(1, 0) != 0x0000000000000003ull);
+	BUILD_BUG_ON(GENMASK_U128(2, 1) != 0x0000000000000006ull);
+	BUILD_BUG_ON(GENMASK_U128(31, 0) != 0x00000000ffffffffull);
+	BUILD_BUG_ON(GENMASK_U128(39, 21) != 0x000000ffffe00000ull);
+	BUILD_BUG_ON(GENMASK_U128(63, 0) != 0xffffffffffffffffull);
 
 	/* Above 64 bit masks - only 64 bit portion can be validated once */
-	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(64, 0) >> 1);
-	KUNIT_EXPECT_EQ(test, 0x00000000ffffffffull, GENMASK_U128(81, 50) >> 50);
-	KUNIT_EXPECT_EQ(test, 0x0000000000ffffffull, GENMASK_U128(87, 64) >> 64);
-	KUNIT_EXPECT_EQ(test, 0x0000000000ff0000ull, GENMASK_U128(87, 80) >> 64);
-
-	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(127, 0) >> 64);
-	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, (u64)GENMASK_U128(127, 0));
-	KUNIT_EXPECT_EQ(test, 0x0000000000000003ull, GENMASK_U128(127, 126) >> 126);
-	KUNIT_EXPECT_EQ(test, 0x0000000000000001ull, GENMASK_U128(127, 127) >> 127);
+	BUILD_BUG_ON(GENMASK_U128(64, 0) >> 1 != 0xffffffffffffffffull);
+	BUILD_BUG_ON(GENMASK_U128(81, 50) >> 50 != 0x00000000ffffffffull);
+	BUILD_BUG_ON(GENMASK_U128(87, 64) >> 64 != 0x0000000000ffffffull);
+	BUILD_BUG_ON(GENMASK_U128(87, 80) >> 64 != 0x0000000000ff0000ull);
+
+	BUILD_BUG_ON(GENMASK_U128(127, 0) >> 64 != 0xffffffffffffffffull);
+	BUILD_BUG_ON((u64)GENMASK_U128(127, 0) != 0xffffffffffffffffull);
+	BUILD_BUG_ON(GENMASK_U128(127, 126) >> 126 != 0x0000000000000003ull);
+	BUILD_BUG_ON(GENMASK_U128(127, 127) >> 127 != 0x0000000000000001ull);
 #ifdef TEST_GENMASK_FAILURES
 	/* these should fail compilation */
 	GENMASK_U128(0, 1);
@@ -129,21 +129,21 @@ static void genmask_input_check_test(struct kunit *test)
 	OPTIMIZER_HIDE_VAR(w);
 
 	/* Unknown input */
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(x, 0, 32));
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(0, x, 32));
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(x, y, 32));
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(x, 0, 32) != 0);
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(0, x, 32) != 0);
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(x, y, 32) != 0);
 
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(z, 0, 32));
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(0, z, 32));
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(z, w, 32));
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(z, 0, 32) != 0);
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(0, z, 32) != 0);
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(z, w, 32) != 0);
 
 	/* Valid input */
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(1, 1, 32));
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(39, 21, 64));
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(1, 1, 32) != 0);
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(39, 21, 64) != 0);
 
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(100, 80, 128));
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(110, 65, 128));
-	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(127, 0, 128));
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(100, 80, 128) != 0);
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(110, 65, 128) != 0);
+	BUILD_BUG_ON(GENMASK_INPUT_CHECK(127, 0, 128) != 0);
 }
 
 
-- 
2.39.5
Re: [PATCH next 13/14] test_bits: Change all the tests to be compile-time tests
Posted by Yury Norov an hour ago 
On Wed, Jan 21, 2026 at 02:57:30PM +0000, david.laight.linux@gmail.com wrote:
> From: David Laight <david.laight.linux@gmail.com>
> 
> Since all the GENMASK() values are compile-time constants they can
> be tested with BUILD_BUG_ON() rather than KUNIT_EXPECT_EQ().
> 
> Signed-off-by: David Laight <david.laight.linux@gmail.com>

I thought, KUNIT invented this EXPECT_EQ macro for a nice printing
and some accounting. If you want to make sure that __GENMASK() is a
compile-time expression, it's OK. But I'd rather keep the existing
KUNIT_EXPECT_EQ() and add

        BUILD_BUG_ON(!__builtin_constant_p(GENMASK()))

next to that. This is actually how test_bitmap_const_eval() works.

Thanks,
Yury

> ---
>  lib/tests/test_bits.c | 90 +++++++++++++++++++++----------------------
>  1 file changed, 45 insertions(+), 45 deletions(-)
> 
> diff --git a/lib/tests/test_bits.c b/lib/tests/test_bits.c
> index 36eb4661e78b..4d3a895f490c 100644
> --- a/lib/tests/test_bits.c
> +++ b/lib/tests/test_bits.c
> @@ -32,30 +32,30 @@ static_assert(assert_type(u64, GENMASK_U64(63, 0)) == U64_MAX);
>  
>  static void __genmask_test(struct kunit *test)
>  {
> -	KUNIT_EXPECT_EQ(test, 1ul, __GENMASK(0, 0));
> -	KUNIT_EXPECT_EQ(test, 3ul, __GENMASK(1, 0));
> -	KUNIT_EXPECT_EQ(test, 6ul, __GENMASK(2, 1));
> -	KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, __GENMASK(31, 0));
> +	BUILD_BUG_ON(__GENMASK(0, 0) != 1ul);
> +	BUILD_BUG_ON(__GENMASK(1, 0) != 3ul);
> +	BUILD_BUG_ON(__GENMASK(2, 1) != 6ul);
> +	BUILD_BUG_ON(__GENMASK(31, 0) != 0xFFFFFFFFul);
>  }
>  
>  static void __genmask_ull_test(struct kunit *test)
>  {
> -	KUNIT_EXPECT_EQ(test, 1ull, __GENMASK_ULL(0, 0));
> -	KUNIT_EXPECT_EQ(test, 3ull, __GENMASK_ULL(1, 0));
> -	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, __GENMASK_ULL(39, 21));
> -	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, __GENMASK_ULL(63, 0));
> +	BUILD_BUG_ON(__GENMASK_ULL(0, 0) != 1ull);
> +	BUILD_BUG_ON(__GENMASK_ULL(1, 0) != 3ull);
> +	BUILD_BUG_ON(__GENMASK_ULL(39, 21) != 0x000000ffffe00000ull);
> +	BUILD_BUG_ON(__GENMASK_ULL(63, 0) != 0xffffffffffffffffull);
>  }
>  
>  static void genmask_test(struct kunit *test)
>  {
> -	KUNIT_EXPECT_EQ(test, 1ul, GENMASK(0, 0));
> -	KUNIT_EXPECT_EQ(test, 3ul, GENMASK(1, 0));
> -	KUNIT_EXPECT_EQ(test, 6ul, GENMASK(2, 1));
> -	KUNIT_EXPECT_EQ(test, 0xFFFFFFFFul, GENMASK(31, 0));
> +	BUILD_BUG_ON(GENMASK(0, 0) != 1ul);
> +	BUILD_BUG_ON(GENMASK(1, 0) != 3ul);
> +	BUILD_BUG_ON(GENMASK(2, 1) != 6ul);
> +	BUILD_BUG_ON(GENMASK(31, 0) != 0xFFFFFFFFul);
>  
> -	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));
> +	BUILD_BUG_ON(GENMASK_U8(0, 0) != 1u);
> +	BUILD_BUG_ON(GENMASK_U16(1, 0) != 3u);
> +	BUILD_BUG_ON(GENMASK_U32(16, 16) != 0x10000);
>  
>  #ifdef TEST_GENMASK_FAILURES
>  	/* these should fail compilation */
> @@ -75,10 +75,10 @@ static void genmask_test(struct kunit *test)
>  
>  static void genmask_ull_test(struct kunit *test)
>  {
> -	KUNIT_EXPECT_EQ(test, 1ull, GENMASK_ULL(0, 0));
> -	KUNIT_EXPECT_EQ(test, 3ull, GENMASK_ULL(1, 0));
> -	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, GENMASK_ULL(39, 21));
> -	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_ULL(63, 0));
> +	BUILD_BUG_ON(GENMASK_ULL(0, 0) != 1ull);
> +	BUILD_BUG_ON(GENMASK_ULL(1, 0) != 3ull);
> +	BUILD_BUG_ON(GENMASK_ULL(39, 21) != 0x000000ffffe00000ull);
> +	BUILD_BUG_ON(GENMASK_ULL(63, 0) != 0xffffffffffffffffull);
>  
>  #ifdef TEST_GENMASK_FAILURES
>  	/* these should fail compilation */
> @@ -92,23 +92,23 @@ static void genmask_u128_test(struct kunit *test)
>  {
>  #ifdef CONFIG_ARCH_SUPPORTS_INT128
>  	/* Below 64 bit masks */
> -	KUNIT_EXPECT_EQ(test, 0x0000000000000001ull, GENMASK_U128(0, 0));
> -	KUNIT_EXPECT_EQ(test, 0x0000000000000003ull, GENMASK_U128(1, 0));
> -	KUNIT_EXPECT_EQ(test, 0x0000000000000006ull, GENMASK_U128(2, 1));
> -	KUNIT_EXPECT_EQ(test, 0x00000000ffffffffull, GENMASK_U128(31, 0));
> -	KUNIT_EXPECT_EQ(test, 0x000000ffffe00000ull, GENMASK_U128(39, 21));
> -	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(63, 0));
> +	BUILD_BUG_ON(GENMASK_U128(0, 0) != 0x0000000000000001ull);
> +	BUILD_BUG_ON(GENMASK_U128(1, 0) != 0x0000000000000003ull);
> +	BUILD_BUG_ON(GENMASK_U128(2, 1) != 0x0000000000000006ull);
> +	BUILD_BUG_ON(GENMASK_U128(31, 0) != 0x00000000ffffffffull);
> +	BUILD_BUG_ON(GENMASK_U128(39, 21) != 0x000000ffffe00000ull);
> +	BUILD_BUG_ON(GENMASK_U128(63, 0) != 0xffffffffffffffffull);
>  
>  	/* Above 64 bit masks - only 64 bit portion can be validated once */
> -	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(64, 0) >> 1);
> -	KUNIT_EXPECT_EQ(test, 0x00000000ffffffffull, GENMASK_U128(81, 50) >> 50);
> -	KUNIT_EXPECT_EQ(test, 0x0000000000ffffffull, GENMASK_U128(87, 64) >> 64);
> -	KUNIT_EXPECT_EQ(test, 0x0000000000ff0000ull, GENMASK_U128(87, 80) >> 64);
> -
> -	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, GENMASK_U128(127, 0) >> 64);
> -	KUNIT_EXPECT_EQ(test, 0xffffffffffffffffull, (u64)GENMASK_U128(127, 0));
> -	KUNIT_EXPECT_EQ(test, 0x0000000000000003ull, GENMASK_U128(127, 126) >> 126);
> -	KUNIT_EXPECT_EQ(test, 0x0000000000000001ull, GENMASK_U128(127, 127) >> 127);
> +	BUILD_BUG_ON(GENMASK_U128(64, 0) >> 1 != 0xffffffffffffffffull);
> +	BUILD_BUG_ON(GENMASK_U128(81, 50) >> 50 != 0x00000000ffffffffull);
> +	BUILD_BUG_ON(GENMASK_U128(87, 64) >> 64 != 0x0000000000ffffffull);
> +	BUILD_BUG_ON(GENMASK_U128(87, 80) >> 64 != 0x0000000000ff0000ull);
> +
> +	BUILD_BUG_ON(GENMASK_U128(127, 0) >> 64 != 0xffffffffffffffffull);
> +	BUILD_BUG_ON((u64)GENMASK_U128(127, 0) != 0xffffffffffffffffull);
> +	BUILD_BUG_ON(GENMASK_U128(127, 126) >> 126 != 0x0000000000000003ull);
> +	BUILD_BUG_ON(GENMASK_U128(127, 127) >> 127 != 0x0000000000000001ull);
>  #ifdef TEST_GENMASK_FAILURES
>  	/* these should fail compilation */
>  	GENMASK_U128(0, 1);
> @@ -129,21 +129,21 @@ static void genmask_input_check_test(struct kunit *test)
>  	OPTIMIZER_HIDE_VAR(w);
>  
>  	/* Unknown input */
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(x, 0, 32));
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(0, x, 32));
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(x, y, 32));
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(x, 0, 32) != 0);
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(0, x, 32) != 0);
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(x, y, 32) != 0);
>  
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(z, 0, 32));
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(0, z, 32));
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(z, w, 32));
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(z, 0, 32) != 0);
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(0, z, 32) != 0);
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(z, w, 32) != 0);
>  
>  	/* Valid input */
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(1, 1, 32));
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(39, 21, 64));
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(1, 1, 32) != 0);
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(39, 21, 64) != 0);
>  
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(100, 80, 128));
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(110, 65, 128));
> -	KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(127, 0, 128));
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(100, 80, 128) != 0);
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(110, 65, 128) != 0);
> +	BUILD_BUG_ON(GENMASK_INPUT_CHECK(127, 0, 128) != 0);
>  }
>  
>  
> -- 
> 2.39.5

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