Topics
	Package convert flags


	Package flags

Macros
#define	CBPRINTF_PACKAGE_ALIGNMENT
	Required alignment of the buffer used for packaging.

#define	CBPRINTF_MUST_RUNTIME_PACKAGE(flags, ...)
	Determine if string must be packaged in run time.

#define	CBPRINTF_STATIC_PACKAGE(packaged, inlen, outlen, align_offset, flags, ...)
	Statically package string.

Typedefs
typedef int(*	cbprintf_cb) ()
	Signature for a cbprintf callback function.

typedef int(*	cbprintf_cb_local) (int c, void *ctx)

typedef int(*	cbprintf_convert_cb) (const void buf, size_t len, void ctx)
	Signature for a cbprintf multibyte callback function.

typedef int(*	cbvprintf_external_formatter_func) (cbprintf_cb out, void ctx, const char fmt, va_list ap)
	Signature for a external formatter function identical to cbvprintf.

Functions
int	cbprintf_package (void packaged, size_t len, uint32_t flags, const char format,...)
	Capture state required to output formatted data later.

int	cbvprintf_package (void packaged, size_t len, uint32_t flags, const char format, va_list ap)
	Capture state required to output formatted data later.

int	cbprintf_package_convert (void in_packaged, size_t in_len, cbprintf_convert_cb cb, void ctx, uint32_t flags, uint16_t *strl, size_t strl_len)
	Convert a package.

static int	cbprintf_package_copy (void in_packaged, size_t in_len, void packaged, size_t len, uint32_t flags, uint16_t *strl, size_t strl_len)
	Copy package with optional appending of strings.

static int	cbprintf_fsc_package (void in_packaged, size_t in_len, void packaged, size_t len)
	Convert package to fully self-contained (fsc) package.

int	cbpprintf_external (cbprintf_cb out, cbvprintf_external_formatter_func formatter, void ctx, void packaged)
	Generate the output for a previously captured format operation using an external formatter.

int	cbprintf (cbprintf_cb out, void ctx, const char format,...)
	*printf-like output through a callback.

static int	cbvprintf (cbprintf_cb out, void ctx, const char format, va_list ap)
	varargs-aware *printf-like output through a callback.

static int	cbvprintf_tagged_args (cbprintf_cb out, void ctx, const char format, va_list ap)
	varargs-aware *printf-like output through a callback with tagged arguments.

static int	cbpprintf (cbprintf_cb out, void ctx, void packaged)
	Generate the output for a previously captured format operation.

int	fprintfcb (FILE stream, const char format,...)
	fprintf using Zephyrs cbprintf infrastructure.

int	vfprintfcb (FILE stream, const char format, va_list ap)
	vfprintf using Zephyrs cbprintf infrastructure.

int	printfcb (const char *format,...)
	printf using Zephyrs cbprintf infrastructure.

int	vprintfcb (const char *format, va_list ap)
	vprintf using Zephyrs cbprintf infrastructure.

int	snprintfcb (char str, size_t size, const char format,...)
	snprintf using Zephyrs cbprintf infrastructure.

int	vsnprintfcb (char str, size_t size, const char format, va_list ap)
	vsnprintf using Zephyrs cbprintf infrastructure.

Detailed Description

Macro Definition Documentation

◆ CBPRINTF_MUST_RUNTIME_PACKAGE

#define CBPRINTF_MUST_RUNTIME_PACKAGE	(		flags,
			... )

#include <zephyr/sys/cbprintf.h>

Value:

Z_CBPRINTF_MUST_RUNTIME_PACKAGE(flags, __VA_ARGS__)

flags

Definition parser.h:96

Determine if string must be packaged in run time.

Static packaging can be applied if size of the package can be determined at compile time. In general, package size can be determined at compile time if there are no string arguments which might be copied into package body if they are considered transient.

Note: By default any char pointers are considered to be pointing at transient strings. This can be narrowed down to non const pointers by using CBPRINTF_PACKAGE_CONST_CHAR_RO.

Parameters

...	String with arguments.
flags	option flags. See Package flags.

Return values

1	if string must be packaged in run time.
0	string can be statically packaged.

◆ CBPRINTF_PACKAGE_ALIGNMENT

#define CBPRINTF_PACKAGE_ALIGNMENT

#include <zephyr/sys/cbprintf.h>

Value:

Z_POW2_CEIL(COND_CODE_1(CONFIG_CBPRINTF_PACKAGE_LONGDOUBLE, \

(sizeof(long double)), (MAX(sizeof(double), sizeof(long long)))))

COND_CODE_1

#define COND_CODE_1(_flag, _if_1_code, _else_code)

Insert code depending on whether _flag expands to 1 or not.

Definition util_macro.h:179

MAX

#define MAX(a, b)

Obtain the maximum of two values.

Definition util.h:392

Required alignment of the buffer used for packaging.

◆ CBPRINTF_STATIC_PACKAGE

#define CBPRINTF_STATIC_PACKAGE	(	packaged,
		inlen,
		outlen,
		align_offset,
		flags,
		... )

#include <zephyr/sys/cbprintf.h>

Value:

Z_CBPRINTF_STATIC_PACKAGE(packaged, inlen, outlen, \

align_offset, flags, __VA_ARGS__)

Statically package string.

Build string package from formatted string. It assumes that formatted string is in the read only memory.

If _Generic is not supported then runtime packaging is performed.

Parameters

packaged	pointer to where the packaged data can be stored. Pass a null pointer to skip packaging but still calculate the total space required. The data stored here is relocatable, that is it can be moved to another contiguous block of memory. It must be aligned to the size of the longest argument. It is recommended to use CBPRINTF_PACKAGE_ALIGNMENT for alignment.
inlen	set to the number of bytes available at `packaged`. If `packaged` is NULL the value is ignored.
outlen	variable updated to the number of bytes required to completely store the packed information. If input buffer was too small it is set to -ENOSPC.
align_offset	input buffer alignment offset in bytes. Where offset 0 means that buffer is aligned to CBPRINTF_PACKAGE_ALIGNMENT. Xtensa requires that `packaged` is aligned to CBPRINTF_PACKAGE_ALIGNMENT so it must be multiply of CBPRINTF_PACKAGE_ALIGNMENT or 0.
flags	option flags. See Package flags.
...	formatted string with arguments. Format string must be constant.

Typedef Documentation

◆ cbprintf_cb

typedef int(* cbprintf_cb) ()

#include <zephyr/sys/cbprintf.h>

Signature for a cbprintf callback function.

This function expects two parameters:

c a character to output. The output behavior should be as if this was cast to an unsigned char.
ctx a pointer to an object that provides context for the output operation.

The declaration does not specify the parameter types. This allows a function like fputc to be used without requiring all context pointers to be to a FILE object.

Returns: the value of c cast to an unsigned char then back to int, or a negative error code that will be returned from cbprintf().

◆ cbprintf_cb_local

typedef int(* cbprintf_cb_local) (int c, void *ctx)

#include <zephyr/sys/cbprintf.h>

◆ cbprintf_convert_cb

typedef int(* cbprintf_convert_cb) (const void *buf, size_t len, void *ctx)

#include <zephyr/sys/cbprintf.h>

Signature for a cbprintf multibyte callback function.

Parameters

buf	data.
len	data length.
ctx	a pointer to an object that provides context for the operation.

return Amount of copied data or negative error code.

◆ cbvprintf_external_formatter_func

typedef int(* cbvprintf_external_formatter_func) (cbprintf_cb out, void *ctx, const char *fmt, va_list ap)

#include <zephyr/sys/cbprintf.h>

Signature for a external formatter function identical to cbvprintf.

This function expects the following parameters:

Parameters

out	the function used to emit each generated character.
ctx	a pointer to an object that provides context for the external formatter.
fmt	a standard ISO C format string with characters and conversion specifications.
ap	captured stack arguments corresponding to the conversion specifications found within `fmt`.

Returns: vprintf like return values: the number of characters printed, or a negative error value returned from external formatter.

Function Documentation

◆ cbpprintf()

static int cbpprintf	(	cbprintf_cb	out,
		void *	ctx,
		void *	packaged )

inlinestatic

#include <zephyr/sys/cbprintf.h>

Generate the output for a previously captured format operation.

Parameters

out	the function used to emit each generated character.
ctx	context provided when invoking out
packaged	the data required to generate the formatted output, as captured by cbprintf_package() or cbvprintf_package(). The alignment requirement on this data is the same as when it was initially created.

Note: Memory indicated by packaged will be modified in a non-destructive way, meaning that it could still be reused with this function again.

Returns: the number of characters printed, or a negative error value returned from invoking out.

◆ cbpprintf_external()

int cbpprintf_external	(	cbprintf_cb	out,
		cbvprintf_external_formatter_func	formatter,
		void *	ctx,
		void *	packaged )

#include <zephyr/sys/cbprintf.h>

Generate the output for a previously captured format operation using an external formatter.

Parameters

out	the function used to emit each generated character.
formatter	external formatter function.
ctx	a pointer to an object that provides context for the external formatter.
packaged	the data required to generate the formatted output, as captured by cbprintf_package() or cbvprintf_package(). The alignment requirement on this data is the same as when it was initially created.

Note: Memory indicated by packaged will be modified in a non-destructive way, meaning that it could still be reused with this function again.

Returns: printf like return values: the number of characters printed, or a negative error value returned from external formatter.

◆ cbprintf()

int cbprintf	(	cbprintf_cb	out,
		void *	ctx,
		const char *	format,
			... )

#include <zephyr/sys/cbprintf.h>

*printf-like output through a callback.

This is essentially printf() except the output is generated character-by-character using the provided out function. This allows formatting text of unbounded length without incurring the cost of a temporary buffer.

All formatting specifiers of C99 are recognized, and most are supported if the functionality is enabled.

Note

The functionality of this function is significantly reduced when

CONFIG_CBPRINTF_NANO

is selected.

Parameters

out	the function used to emit each generated character.
ctx	context provided when invoking out
format	a standard ISO C format string with characters and conversion specifications.
...	arguments corresponding to the conversion specifications found within `format`.

Returns: the number of characters printed, or a negative error value returned from invoking out.

◆ cbprintf_fsc_package()

static int cbprintf_fsc_package	(	void *	in_packaged,
		size_t	in_len,
		void *	packaged,
		size_t	len )

inlinestatic

#include <zephyr/sys/cbprintf.h>

Convert package to fully self-contained (fsc) package.

Package may not be self contain since strings by default are stored by address. Package may be partially self-contained when transient (not read only) strings are appended to the package. Such package can be decoded only when there is an access to read-only strings.

Fully self-contained has (fsc) contains all strings used in the package. A package can be converted to fsc package if it was create with CBPRINTF_PACKAGE_ADD_RO_STR_POS flag. Such package will contain necessary data to find read only strings in the package and copy them into the package body.

Parameters

in_packaged	pointer to original package created with CBPRINTF_PACKAGE_ADD_RO_STR_POS.
in_len	`in_packaged` length.
packaged	pointer to location where fully self-contained version of the input package will be written. Pass a null pointer to calculate space required.
len	must be set to the number of bytes available at `packaged`. Not used if `packaged` is null.

Return values

nonegative	the number of bytes successfully stored at `packaged`. This will not exceed `len`. If `packaged` is null, calculated length.
-ENOSPC	if `packaged` was not null and the space required to store exceed `len`.
-EINVAL	if `in_packaged` is null.

◆ cbprintf_package()

int cbprintf_package	(	void *	packaged,
		size_t	len,
		uint32_t	flags,
		const char *	format,
			... )

#include <zephyr/sys/cbprintf.h>

Capture state required to output formatted data later.

Like cbprintf() but instead of processing the arguments and emitting the formatted results immediately all arguments are captured so this can be done in a different context, e.g. when the output function can block.

In addition to the values extracted from arguments this will ensure that copies are made of the necessary portions of any string parameters that are not confirmed to be stored in read-only memory (hence assumed to be safe to refer to directly later).

Parameters

packaged	pointer to where the packaged data can be stored. Pass a null pointer to store nothing but still calculate the total space required. The data stored here is relocatable, that is it can be moved to another contiguous block of memory. However, under condition that alignment is maintained. It must be aligned to at least the size of a pointer.
len	this must be set to the number of bytes available at `packaged` if it is not null. If `packaged` is null then it indicates hypothetical buffer alignment offset in bytes compared to CBPRINTF_PACKAGE_ALIGNMENT alignment. Buffer alignment offset impacts returned size of the package. Xtensa requires that buffer is always aligned to CBPRINTF_PACKAGE_ALIGNMENT so it must be multiply of CBPRINTF_PACKAGE_ALIGNMENT or 0 when `packaged` is null.
flags	option flags. See Package flags.
format	a standard ISO C format string with characters and conversion specifications.
...	arguments corresponding to the conversion specifications found within `format`.

Return values

nonegative	the number of bytes successfully stored at `packaged`. This will not exceed `len`.
-EINVAL	if `format` is not acceptable
-EFAULT	if `packaged` alignment is not acceptable
-ENOSPC	if `packaged` was not null and the space required to store exceed `len`.

◆ cbprintf_package_convert()

int cbprintf_package_convert	(	void *	in_packaged,
		size_t	in_len,
		cbprintf_convert_cb	cb,
		void *	ctx,
		uint32_t	flags,
		uint16_t *	strl,
		size_t	strl_len )

#include <zephyr/sys/cbprintf.h>

Convert a package.

Converting may include appending strings used in the package to the package body. If input package was created with CBPRINTF_PACKAGE_ADD_RO_STR_POS or CBPRINTF_PACKAGE_ADD_RW_STR_POS, it contains information where strings are located within the package. This information can be used to copy strings during the conversion.

cb is called with portions of the output package. At the end of the conversion cb is called with null buffer.

Parameters

	in_packaged	Input package.
	in_len	Input package length. If 0 package length will be retrieved from the `in_packaged`
	cb	callback called with portions of the converted package. If null only length of the output package is calculated.
	ctx	Context provided to the `cb`.
	flags	Flags. See Package convert flags.
[in,out]	strl	if `packaged` is null, it is a pointer to the array where `strl_len` first string lengths will is stored. If `packaged` is not null, it contains lengths of first `strl_len` strings. It can be used to optimize copying so that string length is calculated only once (at length calculation phase when `packaged` is null.)
	strl_len	Number of elements in `strl` array.

Return values

Positive	output package size.
-ENOSPC	if `packaged` was not null and the space required to store exceed `len`.

◆ cbprintf_package_copy()

static int cbprintf_package_copy	(	void *	in_packaged,
		size_t	in_len,
		void *	packaged,
		size_t	len,
		uint32_t	flags,
		uint16_t *	strl,
		size_t	strl_len )

inlinestatic

#include <zephyr/sys/cbprintf.h>

Copy package with optional appending of strings.

cbprintf_package_convert is used to convert and store converted package in the new location.

Parameters

	in_packaged	Input package.
	in_len	Input package length. If 0 package length will be retrieved from the `in_packaged`
[out]	packaged	Output package. If null only length of the output package is calculated.
	len	Available space in the location pointed by `packaged`. Not used when `packaged` is null.
	flags	Flags. See Package convert flags.
[in,out]	strl	if `packaged` is null, it is a pointer to the array where `strl_len` first string lengths will is stored. If `packaged` is not null, it contains lengths of first `strl_len` strings. It can be used to optimize copying so that string length is calculated only once (at length calculation phase when `packaged` is null.)
	strl_len	Number of elements in `strl` array.

Return values

Positive	Output package size.
-ENOSPC	if `packaged` was not null and the space required to store exceed `len`.

◆ cbvprintf()

static int cbvprintf	(	cbprintf_cb	out,
		void *	ctx,
		const char *	format,
		va_list	ap )

inlinestatic

#include <zephyr/sys/cbprintf.h>

varargs-aware *printf-like output through a callback.

This is essentially vsprintf() except the output is generated character-by-character using the provided out function. This allows formatting text of unbounded length without incurring the cost of a temporary buffer.

Note

This function is available only when

CONFIG_CBPRINTF_LIBC_SUBSTS

is selected.

The functionality of this function is significantly reduced when

CONFIG_CBPRINTF_NANO

is selected.

Parameters

out	the function used to emit each generated character.
ctx	context provided when invoking out
format	a standard ISO C format string with characters and conversion specifications.
ap	a reference to the values to be converted.

Returns: the number of characters generated, or a negative error value returned from invoking out.

◆ cbvprintf_package()

int cbvprintf_package	(	void *	packaged,
		size_t	len,
		uint32_t	flags,
		const char *	format,
		va_list	ap )

#include <zephyr/sys/cbprintf.h>

Capture state required to output formatted data later.

Like cbprintf() but instead of processing the arguments and emitting the formatted results immediately all arguments are captured so this can be done in a different context, e.g. when the output function can block.

In addition to the values extracted from arguments this will ensure that copies are made of the necessary portions of any string parameters that are not confirmed to be stored in read-only memory (hence assumed to be safe to refer to directly later).

Parameters

packaged	pointer to where the packaged data can be stored. Pass a null pointer to store nothing but still calculate the total space required. The data stored here is relocatable, that is it can be moved to another contiguous block of memory. The pointer must be aligned to a multiple of the largest element in the argument list.
len	this must be set to the number of bytes available at `packaged`. Ignored if `packaged` is NULL.
flags	option flags. See Package flags.
format	a standard ISO C format string with characters and conversion specifications.
ap	captured stack arguments corresponding to the conversion specifications found within `format`.

Return values

nonegative	the number of bytes successfully stored at `packaged`. This will not exceed `len`.
-EINVAL	if `format` is not acceptable
-ENOSPC	if `packaged` was not null and the space required to store exceed `len`.

◆ cbvprintf_tagged_args()

static int cbvprintf_tagged_args	(	cbprintf_cb	out,
		void *	ctx,
		const char *	format,
		va_list	ap )

inlinestatic

#include <zephyr/sys/cbprintf.h>

varargs-aware *printf-like output through a callback with tagged arguments.

This is essentially vsprintf() except the output is generated character-by-character using the provided out function. This allows formatting text of unbounded length without incurring the cost of a temporary buffer.

Note that the argument list ap are tagged.

Note

This function is available only when

CONFIG_CBPRINTF_LIBC_SUBSTS

is selected.

The functionality of this function is significantly reduced when

CONFIG_CBPRINTF_NANO

is selected.

Parameters

out	the function used to emit each generated character.
ctx	context provided when invoking out
format	a standard ISO C format string with characters and conversion specifications.
ap	a reference to the values to be converted.

Returns: the number of characters generated, or a negative error value returned from invoking out.

◆ fprintfcb()

int fprintfcb	(	FILE *	stream,
		const char *	format,
			... )

#include <zephyr/sys/cbprintf.h>

fprintf using Zephyrs cbprintf infrastructure.

Note

This function is available only when

CONFIG_CBPRINTF_LIBC_SUBSTS

is selected.

The functionality of this function is significantly reduced when

CONFIG_CBPRINTF_NANO

is selected.

Parameters

stream	the stream to which the output should be written.
format	a standard ISO C format string with characters and conversion specifications.
...	arguments corresponding to the conversion specifications found within `format`.

return The number of characters printed.

◆ printfcb()

int printfcb	(	const char *	format,
			... )

#include <zephyr/sys/cbprintf.h>

printf using Zephyrs cbprintf infrastructure.

Note

This function is available only when

CONFIG_CBPRINTF_LIBC_SUBSTS

is selected.

The functionality of this function is significantly reduced when

CONFIG_CBPRINTF_NANO

is selected.

Parameters

format	a standard ISO C format string with characters and conversion specifications.
...	arguments corresponding to the conversion specifications found within `format`.

Returns: The number of characters printed.

◆ snprintfcb()

int snprintfcb	(	char *	str,
		size_t	size,
		const char *	format,
			... )

#include <zephyr/sys/cbprintf.h>

snprintf using Zephyrs cbprintf infrastructure.

Note

This function is available only when

CONFIG_CBPRINTF_LIBC_SUBSTS

is selected.

The functionality of this function is significantly reduced when

CONFIG_CBPRINTF_NANO

is selected.

Parameters

str	where the formatted content should be written
size	maximum number of chaacters for the formatted output, including the terminating null byte.
format	a standard ISO C format string with characters and conversion specifications.
...	arguments corresponding to the conversion specifications found within `format`.

Returns: The number of characters that would have been written to str, excluding the terminating null byte. This is greater than the number actually written if size is too small.

◆ vfprintfcb()

int vfprintfcb	(	FILE *	stream,
		const char *	format,
		va_list	ap )

#include <zephyr/sys/cbprintf.h>

vfprintf using Zephyrs cbprintf infrastructure.

Note

This function is available only when

CONFIG_CBPRINTF_LIBC_SUBSTS

is selected.

The functionality of this function is significantly reduced when

CONFIG_CBPRINTF_NANO

is selected.

Parameters

stream	the stream to which the output should be written.
format	a standard ISO C format string with characters and conversion specifications.
ap	a reference to the values to be converted.

Returns: The number of characters printed.

◆ vprintfcb()

int vprintfcb	(	const char *	format,
		va_list	ap )

#include <zephyr/sys/cbprintf.h>

vprintf using Zephyrs cbprintf infrastructure.

Note

This function is available only when

CONFIG_CBPRINTF_LIBC_SUBSTS

is selected.

The functionality of this function is significantly reduced when

CONFIG_CBPRINTF_NANO

is selected.

Parameters

format	a standard ISO C format string with characters and conversion specifications.
ap	a reference to the values to be converted.

Returns: The number of characters printed.

◆ vsnprintfcb()

int vsnprintfcb	(	char *	str,
		size_t	size,
		const char *	format,
		va_list	ap )

#include <zephyr/sys/cbprintf.h>

vsnprintf using Zephyrs cbprintf infrastructure.

Note

This function is available only when

CONFIG_CBPRINTF_LIBC_SUBSTS

is selected.

The functionality of this function is significantly reduced when

CONFIG_CBPRINTF_NANO

is selected.

Parameters

str	where the formatted content should be written
size	maximum number of chaacters for the formatted output, including the terminating null byte.
format	a standard ISO C format string with characters and conversion specifications.
ap	a reference to the values to be converted.

Returns: The number of characters that would have been written to str, excluding the terminating null byte. This is greater than the number actually written if size is too small.

Topics

Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

◆ CBPRINTF_MUST_RUNTIME_PACKAGE

◆ CBPRINTF_PACKAGE_ALIGNMENT

◆ CBPRINTF_STATIC_PACKAGE

Typedef Documentation

◆ cbprintf_cb

◆ cbprintf_cb_local

◆ cbprintf_convert_cb

◆ cbvprintf_external_formatter_func

Function Documentation

◆ cbpprintf()

◆ cbpprintf_external()

◆ cbprintf()

◆ cbprintf_fsc_package()

◆ cbprintf_package()

◆ cbprintf_package_convert()

◆ cbprintf_package_copy()

◆ cbvprintf()

◆ cbvprintf_package()

◆ cbvprintf_tagged_args()

◆ fprintfcb()

◆ printfcb()

◆ snprintfcb()

◆ vfprintfcb()

◆ vprintfcb()

◆ vsnprintfcb()