Hi,
On 23 November 2016 at 20:19, Siarhei Siamashka siarhei.siamashka@gmail.com wrote:
On Sun, 20 Nov 2016 14:56:59 +0000 Andre Przywara andre.przywara@arm.com wrote:
tiny-printf does not know about the "l" modifier so far, which breaks the crash dump on AArch64, because it uses %lx to print the registers. Add an easy way of handling longs correctly.
I can't help but notice that the changes of this kind are in a way defeating the original purpose of tiny-printf. And it is surely not the first patch adding features to tiny-printf. I guess, in the end we may end up with a large and bloated printf implementation again :-)
A possible solution might be just a strict check when parsing format modifiers and abort with an error message (yeah, this will introduce some size increase, but hopefully the last one). This way we acknowledge the fact that tiny-printf is a reduced incomplete implementation, and that the callers need to take this into account.
As for the "l" modifier. How much does it add to the code size? IMHO this information should be mentioned in the commit message. Can the AArch64 crash dump code be modified to avoid using it? Or can we have the "l" modifier supported on 64-bit platforms only?
Signed-off-by: Andre Przywara andre.przywara@arm.com
lib/tiny-printf.c | 43 +++++++++++++++++++++++++++++++++---------- 1 file changed, 33 insertions(+), 10 deletions(-)
I think I tested this patch as adding 36 bytes on Thumb2 so not too terrible. But I do agree with the sentiment.
Why is aarch64 using tiny-printf? Surely all though chips have heaps of space?!
Regards, Simon