On Thu, May 6, 2021 at 10:09 PM David Gow <davidgow@xxxxxxxxxx> wrote:
>
> Currently, the KUNIT_EXPECT_STREQ() and related macros assign both
> string arguments to variables of their own type (via typeof()). This
> seems to be to prevent the macro argument from being evaluated multiple
> times.
>
> However, yhis doesn't work if one of these is a fixed-length character
nit: if you ever send a v2 of this patch, s/yhis/this
> array, rather than a character pointer, as (for example) char[16] will
> always allocate a new string.
>
> By always using 'const char*' (the type strcmp expects), we're always
> just taking a pointer to the string, which works even with character
> arrays.
>
> Signed-off-by: David Gow <davidgow@xxxxxxxxxx>
Reviewed-by: Daniel Latypov <dlatypov@xxxxxxxxxx>
I'm very happy to see this patch.
This makes code that looks obviously correct actually work.
Somewhat tangential: there are several casts that are no longer needed
after this in the docs.
I think the following gets rid of all of them. Should it perhaps go in
a chain with this patch?
I.e. if the first one is too controversial and we want to go ahead
split this patch off from it.
diff --git a/Documentation/dev-tools/kunit/usage.rst
b/Documentation/dev-tools/kunit/usage.rst
index 650f99590df5..756747417a19 100644
--- a/Documentation/dev-tools/kunit/usage.rst
+++ b/Documentation/dev-tools/kunit/usage.rst
@@ -465,10 +465,9 @@ fictitious example for ``sha1sum(1)``
.. code-block:: c
- /* Note: the cast is to satisfy overly strict type-checking. */
#define TEST_SHA1(in, want) \
sha1sum(in, out); \
- KUNIT_EXPECT_STREQ_MSG(test, (char *)out, want,
"sha1sum(%s)", in);
+ KUNIT_EXPECT_STREQ_MSG(test, out, want, "sha1sum(%s)", in);
char out[40];
TEST_SHA1("hello world", "2aae6c35c94fcfb415dbe95f408b9ce91ee846ed");
@@ -507,7 +506,7 @@ In some cases, it can be helpful to write a
*table-driven test* instead, e.g.
};
for (i = 0; i < ARRAY_SIZE(cases); ++i) {
sha1sum(cases[i].str, out);
- KUNIT_EXPECT_STREQ_MSG(test, (char *)out, cases[i].sha1,
+ KUNIT_EXPECT_STREQ_MSG(test, out, cases[i].sha1,
"sha1sum(%s)", cases[i].str);
}
@@ -568,7 +567,7 @@ Reusing the same ``cases`` array from above, we
can write the test as a
struct sha1_test_case *test_param = (struct
sha1_test_case *)(test->param_value);
sha1sum(test_param->str, out);
- KUNIT_EXPECT_STREQ_MSG(test, (char *)out, test_param->sha1,
+ KUNIT_EXPECT_STREQ_MSG(test, out, test_param->sha1,
"sha1sum(%s)", test_param->str);
}
> ---
> include/kunit/test.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/kunit/test.h b/include/kunit/test.h
> index 4c56ffcb7403..b68c61348121 100644
> --- a/include/kunit/test.h
> +++ b/include/kunit/test.h
> @@ -1128,8 +1128,8 @@ do { \
> fmt, \
> ...) \
> do { \
> - typeof(left) __left = (left); \
> - typeof(right) __right = (right); \
> + const char *__left = (left); \
> + const char *__right = (right); \
> \
> KUNIT_ASSERTION(test, \
> strcmp(__left, __right) op 0, \
> --
> 2.31.1.607.g51e8a6a459-goog
>
