Re: [kvm-unit-tests PATCH] libfdt: use logical "or" instead of bitwise "or" with boolean operands

[Thomas Huth <thuth@redhat.com>]

On 16/03/2022 08.43, Andrew Jones wrote:
> On Tue, Mar 15, 2022 at 11:02:14PM -0700, Bill Wendling wrote:
>> Clang warns about using a bitwise '|' with boolean operands. This seems
>> to be due to a small typo.
>>
>>    lib/libfdt/fdt_rw.c:438:6: warning: use of bitwise '|' with boolean operands [-Werror,-Wbitwise-instead-of-logical]
>>            if (can_assume(LIBFDT_ORDER) |
>>
>> Using '||' removes this warnings.
>>
>> Signed-off-by: Bill Wendling <morbo@google.com>
>> ---
>>   lib/libfdt/fdt_rw.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/lib/libfdt/fdt_rw.c b/lib/libfdt/fdt_rw.c
>> index 13854253ff86..3320e5559cac 100644
>> --- a/lib/libfdt/fdt_rw.c
>> +++ b/lib/libfdt/fdt_rw.c
>> @@ -435,7 +435,7 @@ int fdt_open_into(const void *fdt, void *buf, int bufsize)
>>   			return struct_size;
>>   	}
>>   
>> -	if (can_assume(LIBFDT_ORDER) |
>> +	if (can_assume(LIBFDT_ORDER) ||
>>   	    !fdt_blocks_misordered_(fdt, mem_rsv_size, struct_size)) {
>>   		/* no further work necessary */
>>   		err = fdt_move(fdt, buf, bufsize);
>> -- 
>> 2.35.1.723.g4982287a31-goog
>>
> 
> This is fixed in libfdt upstream with commit 7be250b4 ("libfdt:
> Correct condition for reordering blocks"), which is in v1.6.1.
> We can either take this patch as a backport of 7be250b4 or we
> can rebase all of our libfdt to v1.6.1. Based on the number of
> fixes in v1.6.1, which appear to be mostly for compiling with
> later compilers, I'm in favor of rebasing.

+1 for updating to v1.6.1 completely.

> Actually, we can also use this opportunity to [re]visit the
> idea of changing libfdt to a git submodule. I'd like to hear
> opinions on that.

I'm always a little bit torn when it comes to this question. Sure, git 
submodules maybe make the update easier ... but they are a real pita when 
you're working with remote machines that might not have direct connection to 
the internet. For example, I'm used to rsync my sources to the non-x86 
machines, and if you forget to update the submodule to the right state 
before the sync, you've just lost. So from my side, it's a preference for 
continuing without submodules (but I won't insist if everybody else wants to 
have them instead).

  Thomas