possible snprintf() regression in 3.3.2

Tony Cook tony@develop-help.com
Sun Nov 21 00:16:13 GMT 2021

On Thu, Nov 18, 2021 at 09:08:40PM +0000, Sam Edge via Cygwin wrote:
> I use newlib on embedded with threading libs that have predetermined
> fixed thread stack sizes. While we tend to have more RAM than in former
> times we also have multiple thread stacks. Use of alloca() or variable
> length automatic arrays makes me wince especially in code I might not be
> able to avoid calling which is often the case with XXXprintf() in
> third-party libraries' debug output. I'd usually rather take the
> performance hit from using heap instead of having to make all my stacks
> bigger.

A simple option would be to use an small auto fixed buffer for most
conversions, but use malloc() for %f formats for numbers greater in
magnitude than some limit, though it would also need to be adjusted
for the precision (ndigits here), since they take extra space.

This would avoid using the optional-to-implement VLA feature too.


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