On 25/09/2020 05:12, David Gibson wrote:
> On Mon, Sep 21, 2020 at 05:53:03PM +0100, Andre Przywara wrote:
>> With -Wsign-compare, compilers warn about a mismatching signedness
>> in a comparison in fdt_strerror().
>>
>> At this point we are sure that errval is negative, and since
>> FDT_ERRTABSIZE is surely positive, we can do some casting to make the
>> compiler happy.
>>
>> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
>
> Since error values are typically conveyed as negative numbers (which
> is kind of the whole reason we have all these signed values in the
> first place), I think it would be slightly nicer to actually fold the
> case to signed into the definition of FDT_ERRTABSIZE.
Right, makes more sense. I changed the comparison to:
if (-errval < FDT_ERRTABSIZE)
which is more in line with what we actually do below.
Cheers,
Andre
>> ---
>> libfdt/fdt_strerror.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/libfdt/fdt_strerror.c b/libfdt/fdt_strerror.c
>> index 768db66..efce51d 100644
>> --- a/libfdt/fdt_strerror.c
>> +++ b/libfdt/fdt_strerror.c
>> @@ -48,7 +48,7 @@ const char *fdt_strerror(int errval)
>> return "<valid offset/length>";
>> else if (errval == 0)
>> return "<no error>";
>> - else if (errval > -FDT_ERRTABSIZE) {
>> + else if (errval > -(int)FDT_ERRTABSIZE) {
>> const char *s = fdt_errtable[-errval].str;
>>
>> if (s)
>
