Hi Petr,
On Wed, Aug 16, 2023 at 01:01:46PM +0200, Petr Mladek wrote:
On Mon 2023-08-07 08:36:28, 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.
Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/1899
"Closes:" is not a valid tag. It was proposed and rejected in the end. I replaced it with "Link:" as suggested by ./scripts/checkpatch.pl/
I don't really care about "Closes:" vs. "Link:", either is fine with me, but checkpatch.pl did not warn me about it and I still see commit 44c31888098a ("checkpatch: allow Closes tags with links") in mainline and -next that explicitly allows this (and even requires Closes: instead of Link: when following Reported-by:).
Link: https://github.com/llvm/llvm-project/commit/610ec954e1f81c0e8fcadedcd25afe64... Suggested-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Nathan Chancellor nathan@kernel.org
Reviewed-by: Petr Mladek pmladek@suse.com
The patch has been pushed into printk/linux.git, branch for-6.6.
Thanks a lot for the review and acceptance!
Cheers, Nathan