Messages in this thread | | | Date | Fri, 4 Aug 2023 07:48:59 -0700 | From | Nathan Chancellor <> | Subject | Re: [PATCH] lib: test_scanf: Add explicit type cast to result initialization in test_number_prefix() |
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On Fri, Aug 04, 2023 at 07:25:00AM +0300, Andy Shevchenko wrote: > 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] }; \
Sure. I can send a v2 on Monday to give folks a chance to chime in with other comments.
> > _test(fn, &expect, str, scan_fmt, n_args, &result[0], &result[1]); \ > > } while (0) > > -- > With Best Regards, > Andy Shevchenko > >
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