Messages in this thread | | | Date | Fri, 4 Aug 2023 07:25:00 +0300 | From | Andy Shevchenko <> | Subject | Re: [PATCH] lib: test_scanf: Add explicit type cast to result initialization in test_number_prefix() |
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On Thu, Aug 03, 2023 at 11:14:42AM -0700, Nathan Chancellor wrote: > A recent change in clang allows it to consider more expressions as > compile time constants, which causes it to point out an implicit > conversion in the scanf tests: > > lib/test_scanf.c:661:2: warning: implicit conversion from 'int' to 'unsigned char' changes value from -168 to 88 [-Wconstant-conversion] > 661 | test_number_prefix(unsigned char, "0xA7", "%2hhx%hhx", 0, 0xa7, 2, check_uchar); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > lib/test_scanf.c:609:29: note: expanded from macro 'test_number_prefix' > 609 | T result[2] = {~expect[0], ~expect[1]}; \ > | ~ ^~~~~~~~~~ > 1 warning generated. > > The result of the bitwise negation is the type of the operand after > going through the integer promotion rules, so this truncation is > expected but harmless, as the initial values in the result array get > overwritten by _test() anyways. Add an explicit cast to the expected > type in test_number_prefix() to silence the warning. There is no > functional change, as all the tests still pass with GCC 13.1.0 and clang > 18.0.0.
> do { \ > const T expect[2] = { expect0, expect1 }; \ > - T result[2] = {~expect[0], ~expect[1]}; \ > + T result[2] = {(T)~expect[0], (T)~expect[1]}; \
Can we add spaces as above, while at it?
T result[2] = { (T)~expect[0], (T)~expect[1] }; \
> _test(fn, &expect, str, scan_fmt, n_args, &result[0], &result[1]); \ > } while (0)
-- With Best Regards, Andy Shevchenko
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