[Cake] [PATCH 1/2] cake: print_uint format fixes

Kevin Darbyshire-Bryant kevin at darbyshire-bryant.me.uk
Mon Mar 12 05:28:43 EDT 2018

> On 11 Mar 2018, at 23:34, Stephen Hemminger <stephen at networkplumber.org> wrote:
> On Sun, 11 Mar 2018 22:10:51 +0000
> Kevin Darbyshire-Bryant <kevin at darbyshire-bryant.me.uk> wrote:
>> negative?
>> Tried it, and you’d sort of guess wrong.  I’ll write it up tomorrow ‘properly’ but ‘int’ is int length whereas uint is uint64 length.  On big endian it goes wrong.
>> Anyway, glad you’ve tested on something little endian.  I’ll try to submit a patch upstream as requested…very busy over next 3 days doing $dayjob so may take a little while.  Thanks for boosting confidence that I’ve not broken it on architectures it used to work on :-)
> print_uint should be unsigned only.
> When printing json your version won't work with negative values.

Yes, it should be:  print_int(PRINT_ANY, "overhead", "overhead %d ", overhead);   - certainly that works on my 32 bit big endian box.

Using the ‘PRId64’ macro won’t work because print_int is using ‘int’ type internally whereas print_uint uses ‘uint64_t’ internally.  So the format string has to have knowledge of the internal format, *but* there’s no clue of the difference in internal format offered by the function name i.e.  print_int vs print_uint.

I’d argue it makes more sense to have: print_int/print_uint as the native int length, that hopefully match up with %u & %d  and then have print_int64/print_uint64 where use of formats PRId64 & PRIu64 is advised.

But I’m definitely arguing from a position of lack of knowledge/experience.


Kevin D-B

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