On Fri, Jun 07, 2019 at 12:00:47PM -0700, Stephen Boyd wrote:
Quoting Iurii Zaikin (2019-06-05 18:29:42)
On Fri, May 17, 2019 at 11:22 AM Stephen Boyd sboyd@kernel.org wrote:
Quoting Brendan Higgins (2019-05-14 15:17:10)
diff --git a/kernel/sysctl-test.c b/kernel/sysctl-test.c new file mode 100644 index 0000000000000..fe0f2bae66085 --- /dev/null +++ b/kernel/sysctl-test.c
+static void sysctl_test_dointvec_happy_single_negative(struct kunit *test) +{
struct ctl_table table = {.procname = "foo",.data = &test_data.int_0001,.maxlen = sizeof(int),.mode = 0644,.proc_handler = proc_dointvec,.extra1 = &i_zero,.extra2 = &i_one_hundred,};char input[] = "-9";size_t len = sizeof(input) - 1;loff_t pos = 0;table.data = kunit_kzalloc(test, sizeof(int), GFP_USER);KUNIT_EXPECT_EQ(test, 0, proc_dointvec(&table, 1, input, &len, &pos));KUNIT_EXPECT_EQ(test, sizeof(input) - 1, len);KUNIT_EXPECT_EQ(test, sizeof(input) - 1, pos);KUNIT_EXPECT_EQ(test, -9, *(int *)table.data);Is the casting necessary? Or can the macro do a type coercion of the second parameter based on the first type?
Data field is defined as void* so I believe casting is necessary to dereference it as a pointer to an array of ints. I don't think the macro should do any type coercion that == operator wouldn't do. I did change the cast to make it more clear that it's a pointer to an array of ints being dereferenced.
Ok, I still wonder if we should make KUNIT_EXPECT_EQ check the types on both sides and cause a build warning/error if the types aren't the same. This would be similar to our min/max macros that complain about mismatched types in the comparisons. Then if a test developer needs to convert one type or the other they could do so with a KUNIT_EXPECT_EQ_T() macro that lists the types to coerce both sides to explicitly.
Do you think it would be better to do a phony compare similar to how min/max used to work prior to 4.17, or to use the new __typecheck(...) macro? This might seem like a dumb question (and maybe it is), but Iurii and I thought the former created an error message that was a bit easier to understand, whereas __typecheck is obviously superior in terms of code reuse.
This is what we are thinking right now; if you don't have any complaints I will squash it into the relevant commits on the next revision: --- From: Iurii Zaikin yzaikin@google.com
Adds a warning message when comparing values of different types similar to what min() / max() macros do.
Signed-off-by: Iurii Zaikin yzaikin@google.com --- include/kunit/test.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/include/kunit/test.h b/include/kunit/test.h index 511c9e85401a6..791e22fba5620 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -335,6 +335,13 @@ void __printf(3, 4) kunit_printk(const char *level, #define kunit_err(test, fmt, ...) \ kunit_printk(KERN_ERR, test, fmt, ##__VA_ARGS__)
+/* + * 'Unnecessary' cast serves to generate a compile-time warning in case + * of comparing incompatible types. Inspired by include/linux/kernel.h + */ +#define __kunit_typecheck(lhs, rhs) \ + ((void) (&(lhs) == &(rhs))) + static inline struct kunit_stream *kunit_expect_start(struct kunit *test, const char *file, const char *line) @@ -514,6 +521,7 @@ static inline void kunit_expect_ptr_binary(struct kunit *test, #define KUNIT_EXPECT_BINARY(test, left, condition, right) do { \ typeof(left) __left = (left); \ typeof(right) __right = (right); \ + __kunit_typecheck(__left, __right); \ kunit_expect_binary(test, \ (long long) __left, #left, \ (long long) __right, #right, \ @@ -524,6 +532,7 @@ static inline void kunit_expect_ptr_binary(struct kunit *test, #define KUNIT_EXPECT_BINARY_MSG(test, left, condition, right, fmt, ...) do { \ typeof(left) __left = (left); \ typeof(right) __right = (right); \ + __kunit_typecheck(__left, __right); \ kunit_expect_binary_msg(test, \ (long long) __left, #left, \ (long long) __right, #right, \ @@ -538,6 +547,7 @@ static inline void kunit_expect_ptr_binary(struct kunit *test, #define KUNIT_EXPECT_PTR_BINARY(test, left, condition, right) do { \ typeof(left) __left = (left); \ typeof(right) __right = (right); \ + __kunit_typecheck(__left, __right); \ kunit_expect_ptr_binary(test, \ (void *) __left, #left, \ (void *) __right, #right, \ @@ -553,6 +563,7 @@ static inline void kunit_expect_ptr_binary(struct kunit *test, ...) do { \ typeof(left) __left = (left); \ typeof(right) __right = (right); \ + __kunit_typecheck(__left, __right); \ kunit_expect_ptr_binary_msg(test, \ (void *) __left, #left, \ (void *) __right, #right, \ @@ -1013,6 +1024,7 @@ static inline void kunit_assert_ptr_binary(struct kunit *test, #define KUNIT_ASSERT_BINARY(test, left, condition, right) do { \ typeof(left) __left = (left); \ typeof(right) __right = (right); \ + __kunit_typecheck(__left, __right); \ kunit_assert_binary(test, \ (long long) __left, #left, \ (long long) __right, #right, \ @@ -1023,6 +1035,7 @@ static inline void kunit_assert_ptr_binary(struct kunit *test, #define KUNIT_ASSERT_BINARY_MSG(test, left, condition, right, fmt, ...) do { \ typeof(left) __left = (left); \ typeof(right) __right = (right); \ + __kunit_typecheck(__left, __right); \ kunit_assert_binary_msg(test, \ (long long) __left, #left, \ (long long) __right, #right, \ @@ -1037,6 +1050,7 @@ static inline void kunit_assert_ptr_binary(struct kunit *test, #define KUNIT_ASSERT_PTR_BINARY(test, left, condition, right) do { \ typeof(left) __left = (left); \ typeof(right) __right = (right); \ + __kunit_typecheck(__left, __right); \ kunit_assert_ptr_binary(test, \ (void *) __left, #left, \ (void *) __right, #right, \ @@ -1051,6 +1065,7 @@ static inline void kunit_assert_ptr_binary(struct kunit *test, fmt, ...) do { \ typeof(left) __left = (left); \ typeof(right) __right = (right); \ + __kunit_typecheck(__left, __right); \ kunit_assert_ptr_binary_msg(test, \ (void *) __left, #left, \ (void *) __right, #right, \