Added parameter to CBPRINTF_STATIC_PACKAGE which indicates buffer
alignment offset compared to CBPRINTF_PACKAGE_ALIGNMENT. When offset
is set to 0, macro assumes that input buffer is aligned to
CBPRINTF_PACKAGE_ALIGNMENT. When offset is positive, macro assumes
that buffer address is shifted by given number of bytes to
CBPRINTF_PACKAGE_ALIGNMENT alignment.
Extended cbprintf_package to use len argument as alignment offset
indicator when calculating length only (package pointer is null).
Features are not available for xtensa platform which seems to
require 16 byte alignment from the package. It is only an assumption
due to lack of the documentation and may be fixed in the future.
Feature allows to avoid unnecessary padding when package is part of
a message and preceeded by a header of a known size. For example,
message header on 32 bit architecture has 12 bytes, long doubles are
not used so cbprintf requires 8 byte alignment. Without alignment
offset indicator, package containing just a string with one argument
would need 4 byte padding after the header and 4 byte padding after
the package. Message would be 32 bytes long. With alignment offset
indication both paddings are not needed and message is only 24 bytes
long.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
Due to the fact that define was created after including
cbprintf_internal.h, it was not used there. Change the order and fix
the issue that was revealed.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
Added validation of alignment to cbprintf_package. Error is returned if
input buffer is not aligned to the largest argument.
Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
In applications like logging the call site where arguments to
formatting are available may not be suitable for performing the
formatting, e.g. when the output operation can sleep. Add API that
supports capturing data that may be transient into a buffer that can
be saved, and API that then produces the output later using the
packaged arguments.
[ Documentation and commit log from Peter Bigot. ]
Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
Use the @option directive to ensure the generated documentation links
to the specified Kconfig option.
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
This allows applications that may not use minimal libc avoid the cost
of a second printf-like formatting infrastructure by using printfcb()
instead of printf() for output. It also helps make sure that the
formatting support (e.g. floats) is consistent between user-directed
output and the logging infrastructure.
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
A prototype missed the condition for its availability; another
documented arguments that are not present.
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
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>
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>
