Commit Graph

2 Commits

Author SHA1 Message Date
Peter Bigot
d12a99588b lib: cbprintf: remove cbprintf_arglen
This function was designed to support the logging infrastructure's
need to copy values from va_list structures.  It did not meet that
need, since some values need to be changed based on additional data
that is only available when the complete format specification is
examined.  Remove the function as unnecessary.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2021-01-07 14:02:06 +01:00
Peter Bigot
33103828dc lib: add cbprintf capability
This commit adds a C99 stdio value formatter capability where
generated text is emitted through a callback.  This allows generation
of arbitrarily long output without a buffer, functionality that is
core to printk, logging, and other system and application needs.

The formatter supports most C99 specifications, excluding:
* %Lf long double conversion
* wide character output

Kconfig options allow disabling features like floating-point
conversion if they are not necessary.  By default most conversions are
enabled.

The original z_vprintk() implementation is adapted to meet the
interface requirements of cbvprintf, and made available as an opt-in
feature for space-constrained applications that do not need full
formatting support.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2020-11-13 06:38:01 -05:00