Zephyr API Documentation
3.7.0
A Scalable Open Source RTOS
|
Macros | |
#define | POINTER_TO_UINT(x) ((uintptr_t) (x)) |
Cast x , a pointer, to an unsigned integer. | |
#define | UINT_TO_POINTER(x) ((void *) (uintptr_t) (x)) |
Cast x , an unsigned integer, to a void* . | |
#define | POINTER_TO_INT(x) ((intptr_t) (x)) |
Cast x , a pointer, to a signed integer. | |
#define | INT_TO_POINTER(x) ((void *) (intptr_t) (x)) |
Cast x , a signed integer, to a void* . | |
#define | BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__) |
Number of bits in a long int. | |
#define | BITS_PER_LONG_LONG (__CHAR_BIT__ * __SIZEOF_LONG_LONG__) |
Number of bits in a long long int. | |
#define | GENMASK(h, l) (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h)))) |
Create a contiguous bitmask starting at bit position l and ending at position h . | |
#define | GENMASK64(h, l) (((~0ULL) - (1ULL << (l)) + 1) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h)))) |
Create a contiguous 64-bit bitmask starting at bit position l and ending at position h . | |
#define | LSB_GET(value) ((value) & -(value)) |
Extract the Least Significant Bit from value . | |
#define | FIELD_GET(mask, value) (((value) & (mask)) / LSB_GET(mask)) |
Extract a bitfield element from value corresponding to the field mask mask . | |
#define | FIELD_PREP(mask, value) (((value) * LSB_GET(mask)) & (mask)) |
Prepare a bitfield element using value with mask representing its field position and width. | |
#define | ZERO_OR_COMPILE_ERROR(cond) ((int) sizeof(char[1 - 2 * !(cond)]) - 1) |
0 if cond is true-ish; causes a compile error otherwise. | |
#define | IS_ARRAY(array) |
Zero if array has an array type, a compile error otherwise. | |
#define | ARRAY_SIZE(array) ((size_t) (IS_ARRAY(array) + (sizeof(array) / sizeof((array)[0])))) |
Number of elements in the given array . | |
#define | IS_ARRAY_ELEMENT(array, ptr) |
Whether ptr is an element of array . | |
#define | ARRAY_INDEX(array, ptr) |
Index of ptr within array . | |
#define | PART_OF_ARRAY(array, ptr) |
Check if a pointer ptr lies within array . | |
#define | ARRAY_INDEX_FLOOR(array, ptr) |
Array-index of ptr within array , rounded down. | |
#define | ARRAY_FOR_EACH(array, idx) for (size_t idx = 0; (idx) < ARRAY_SIZE(array); ++(idx)) |
Iterate over members of an array using an index variable. | |
#define | ARRAY_FOR_EACH_PTR(array, ptr) |
Iterate over members of an array using a pointer. | |
#define | SAME_TYPE(a, b) __builtin_types_compatible_p(__typeof__(a), __typeof__(b)) |
Validate if two entities have a compatible type. | |
#define | CONTAINER_OF_VALIDATE(ptr, type, field) |
Validate CONTAINER_OF parameters, only applies to C mode. | |
#define | CONTAINER_OF(ptr, type, field) |
Get a pointer to a structure containing the element. | |
#define | SIZEOF_FIELD(type, member) sizeof((((type *)0)->member)) |
Report the size of a struct field in bytes. | |
#define | CONCAT(...) UTIL_CAT(_CONCAT_, NUM_VA_ARGS_LESS_1(__VA_ARGS__))(__VA_ARGS__) |
Concatenate input arguments. | |
#define | IS_ALIGNED(ptr, align) (((uintptr_t)(ptr)) % (align) == 0) |
Check if ptr is aligned to align alignment. | |
#define | ROUND_UP(x, align) |
Value of x rounded up to the next multiple of align . | |
#define | ROUND_DOWN(x, align) (((unsigned long)(x) / (unsigned long)(align)) * (unsigned long)(align)) |
Value of x rounded down to the previous multiple of align . | |
#define | WB_UP(x) ROUND_UP(x, sizeof(void *)) |
Value of x rounded up to the next word boundary. | |
#define | WB_DN(x) ROUND_DOWN(x, sizeof(void *)) |
Value of x rounded down to the previous word boundary. | |
#define | DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) |
Divide and round up. | |
#define | DIV_ROUND_CLOSEST(n, d) |
Divide and round to the nearest integer. | |
#define | ceiling_fraction(numerator, divider) |
Ceiling function applied to numerator / divider as a fraction. | |
#define | MAX(a, b) (((a) > (b)) ? (a) : (b)) |
Obtain the maximum of two values. | |
#define | MIN(a, b) (((a) < (b)) ? (a) : (b)) |
Obtain the minimum of two values. | |
#define | CLAMP(val, low, high) (((val) <= (low)) ? (low) : MIN(val, high)) |
Clamp a value to a given range. | |
#define | IN_RANGE(val, min, max) ((val) >= (min) && (val) <= (max)) |
Checks if a value is within range. | |
#define | LOG2(x) ((x) < 1 ? -1 : __z_log2(x)) |
Compute log2(x) | |
#define | LOG2CEIL(x) ((x) < 1 ? 0 : __z_log2((x)-1) + 1) |
Compute ceil(log2(x)) | |
#define | NHPOT(x) ((x) < 1 ? 1 : ((x) > (1ULL<<63) ? 0 : 1ULL << LOG2CEIL(x))) |
Compute next highest power of two. | |
#define | KB(x) ((x) << 10) |
Number of bytes in x kibibytes. | |
#define | MB(x) (KB(x) << 10) |
Number of bytes in x mebibytes. | |
#define | GB(x) (MB(x) << 10) |
Number of bytes in x gibibytes. | |
#define | KHZ(x) ((x) * 1000) |
Number of Hz in x kHz. | |
#define | MHZ(x) (KHZ(x) * 1000) |
Number of Hz in x MHz. | |
#define | WAIT_FOR(expr, timeout, delay_stmt) |
Wait for an expression to return true with a timeout. | |
#define | BIT(n) (1UL << (n)) |
Unsigned integer with bit position n set (signed in assembly language). | |
#define | BIT64(_n) (1ULL << (_n)) |
64-bit unsigned integer with bit position _n set. | |
#define | WRITE_BIT(var, bit, set) ((var) = (set) ? ((var) | BIT(bit)) : ((var) & ~BIT(bit))) |
Set or clear a bit depending on a boolean value. | |
#define | BIT_MASK(n) (BIT(n) - 1UL) |
Bit mask with bits 0 through n-1 (inclusive) set, or 0 if n is 0. | |
#define | BIT64_MASK(n) (BIT64(n) - 1ULL) |
64-bit bit mask with bits 0 through n-1 (inclusive) set, or 0 if n is 0. | |
#define | IS_POWER_OF_TWO(x) (((x) != 0U) && (((x) & ((x) - 1U)) == 0U)) |
Check if a x is a power of two. | |
#define | IS_SHIFTED_BIT_MASK(m, s) (!(((m) >> (s)) & (((m) >> (s)) + 1U))) |
Check if bits are set continuously from the specified bit. | |
#define | IS_BIT_MASK(m) IS_SHIFTED_BIT_MASK(m, 0) |
Check if bits are set continuously from the LSB. | |
#define | IS_ENABLED(config_macro) Z_IS_ENABLED1(config_macro) |
Check for macro definition in compiler-visible expressions. | |
#define | COND_CODE_1(_flag, _if_1_code, _else_code) Z_COND_CODE_1(_flag, _if_1_code, _else_code) |
Insert code depending on whether _flag expands to 1 or not. | |
#define | COND_CODE_0(_flag, _if_0_code, _else_code) Z_COND_CODE_0(_flag, _if_0_code, _else_code) |
Like COND_CODE_1() except tests if _flag is 0. | |
#define | IF_ENABLED(_flag, _code) COND_CODE_1(_flag, _code, ()) |
Insert code if _flag is defined and equals 1. | |
#define | IF_DISABLED(_flag, _code) COND_CODE_1(_flag, (), _code) |
Insert code if _flag is not defined as 1. | |
#define | IS_EMPTY(...) Z_IS_EMPTY_(__VA_ARGS__) |
Check if a macro has a replacement expression. | |
#define | IS_EQ(a, b) Z_IS_EQ(a, b) |
Like a == b , but does evaluation and short-circuiting at C preprocessor time. | |
#define | LIST_DROP_EMPTY(...) Z_LIST_DROP_FIRST(FOR_EACH(Z_LIST_NO_EMPTIES, (), __VA_ARGS__)) |
Remove empty arguments from list. | |
#define | EMPTY |
Macro with an empty expansion. | |
#define | IDENTITY(V) V |
Macro that expands to its argument. | |
#define | GET_ARG_N(N, ...) Z_GET_ARG_##N(__VA_ARGS__) |
Get nth argument from argument list. | |
#define | GET_ARGS_LESS_N(N, ...) Z_GET_ARGS_LESS_##N(__VA_ARGS__) |
Strips n first arguments from the argument list. | |
#define | UTIL_OR(a, b) COND_CODE_1(UTIL_BOOL(a), (a), (b)) |
Like a || b , but does evaluation and short-circuiting at C preprocessor time. | |
#define | UTIL_AND(a, b) COND_CODE_1(UTIL_BOOL(a), (b), (0)) |
Like a && b , but does evaluation and short-circuiting at C preprocessor time. | |
#define | UTIL_INC(x) UTIL_PRIMITIVE_CAT(Z_UTIL_INC_, x) |
UTIL_INC(x) for an integer literal x from 0 to 4095 expands to an integer literal whose value is x+1. | |
#define | UTIL_DEC(x) UTIL_PRIMITIVE_CAT(Z_UTIL_DEC_, x) |
UTIL_DEC(x) for an integer literal x from 0 to 4095 expands to an integer literal whose value is x-1. | |
#define | UTIL_X2(y) UTIL_PRIMITIVE_CAT(Z_UTIL_X2_, y) |
UTIL_X2(y) for an integer literal y from 0 to 4095 expands to an integer literal whose value is 2y. | |
#define | LISTIFY(LEN, F, sep, ...) UTIL_CAT(Z_UTIL_LISTIFY_, LEN)(F, sep, __VA_ARGS__) |
Generates a sequence of code with configurable separator. | |
#define | FOR_EACH(F, sep, ...) Z_FOR_EACH(F, sep, REVERSE_ARGS(__VA_ARGS__)) |
Call a macro F on each provided argument with a given separator between each call. | |
#define | FOR_EACH_NONEMPTY_TERM(F, term, ...) |
Like FOR_EACH(), but with a terminator instead of a separator, and drops empty elements from the argument list. | |
#define | FOR_EACH_IDX(F, sep, ...) Z_FOR_EACH_IDX(F, sep, REVERSE_ARGS(__VA_ARGS__)) |
Call macro F on each provided argument, with the argument's index as an additional parameter. | |
#define | FOR_EACH_FIXED_ARG(F, sep, fixed_arg, ...) Z_FOR_EACH_FIXED_ARG(F, sep, fixed_arg, REVERSE_ARGS(__VA_ARGS__)) |
Call macro F on each provided argument, with an additional fixed argument as a parameter. | |
#define | FOR_EACH_IDX_FIXED_ARG(F, sep, fixed_arg, ...) Z_FOR_EACH_IDX_FIXED_ARG(F, sep, fixed_arg, REVERSE_ARGS(__VA_ARGS__)) |
Calls macro F for each variable argument with an index and fixed argument. | |
#define | REVERSE_ARGS(...) Z_FOR_EACH_ENGINE(Z_FOR_EACH_EXEC, (,), Z_BYPASS, _, __VA_ARGS__) |
Reverse arguments order. | |
#define | NUM_VA_ARGS_LESS_1(...) |
Number of arguments in the variable arguments list minus one. | |
#define | NUM_VA_ARGS(...) COND_CODE_1(IS_EMPTY(__VA_ARGS__), (0), (UTIL_INC(NUM_VA_ARGS_LESS_1(__VA_ARGS__)))) |
Number of arguments in the variable arguments list. | |
#define | MACRO_MAP_CAT(...) MACRO_MAP_CAT_(__VA_ARGS__) |
Mapping macro that pastes results together. | |
#define | MACRO_MAP_CAT_N(N, ...) MACRO_MAP_CAT_N_(N, __VA_ARGS__) |
Mapping macro that pastes a fixed number of results together. | |
Functions | |
static bool | is_power_of_two (unsigned int x) |
Is x a power of two? | |
static ALWAYS_INLINE bool | is_null_no_warn (void *p) |
Is p equal to NULL ? | |
static int64_t | arithmetic_shift_right (int64_t value, uint8_t shift) |
Arithmetic shift right. | |
static void | bytecpy (void *dst, const void *src, size_t size) |
byte by byte memcpy. | |
static void | byteswp (void *a, void *b, size_t size) |
byte by byte swap. | |
int | char2hex (char c, uint8_t *x) |
Convert a single character into a hexadecimal nibble. | |
int | hex2char (uint8_t x, char *c) |
Convert a single hexadecimal nibble into a character. | |
size_t | bin2hex (const uint8_t *buf, size_t buflen, char *hex, size_t hexlen) |
Convert a binary array into string representation. | |
size_t | hex2bin (const char *hex, size_t hexlen, uint8_t *buf, size_t buflen) |
Convert a hexadecimal string into a binary array. | |
static uint8_t | bcd2bin (uint8_t bcd) |
Convert a binary coded decimal (BCD 8421) value to binary. | |
static uint8_t | bin2bcd (uint8_t bin) |
Convert a binary value to binary coded decimal (BCD 8421). | |
uint8_t | u8_to_dec (char *buf, uint8_t buflen, uint8_t value) |
Convert a uint8_t into a decimal string representation. | |
static int32_t | sign_extend (uint32_t value, uint8_t index) |
Sign extend an 8, 16 or 32 bit value using the index bit as sign bit. | |
static int64_t | sign_extend_64 (uint64_t value, uint8_t index) |
Sign extend a 64 bit value using the index bit as sign bit. | |
char * | utf8_trunc (char *utf8_str) |
Properly truncate a NULL-terminated UTF-8 string. | |
char * | utf8_lcpy (char *dst, const char *src, size_t n) |
Copies a UTF-8 encoded string from src to dst . | |
static void | mem_xor_n (uint8_t *dst, const uint8_t *src1, const uint8_t *src2, size_t len) |
XOR n bytes. | |
static void | mem_xor_32 (uint8_t dst[4], const uint8_t src1[4], const uint8_t src2[4]) |
XOR 32 bits. | |
static void | mem_xor_128 (uint8_t dst[16], const uint8_t src1[16], const uint8_t src2[16]) |
XOR 128 bits. | |
#define ARRAY_FOR_EACH | ( | array, | |
idx | |||
) | for (size_t idx = 0; (idx) < ARRAY_SIZE(array); ++(idx)) |
#include <zephyr/sys/util.h>
Iterate over members of an array using an index variable.
array | the array in question |
idx | name of array index variable |
#define ARRAY_FOR_EACH_PTR | ( | array, | |
ptr | |||
) |
#include <zephyr/sys/util.h>
Iterate over members of an array using a pointer.
array | the array in question |
ptr | pointer to an element of array |
#define ARRAY_INDEX | ( | array, | |
ptr | |||
) |
#include <zephyr/sys/util.h>
Index of ptr
within array
.
With CONFIG_ASSERT=y
, this macro will trigger a runtime assertion when ptr
does not fall into the range of array
or when ptr
is not aligned to an array-element boundary of array
.
In C, passing a pointer as array
causes a compile error.
array | the array in question |
ptr | pointer to an element of array |
ptr
within array
, on success #define ARRAY_INDEX_FLOOR | ( | array, | |
ptr | |||
) |
#include <zephyr/sys/util.h>
Array-index of ptr
within array
, rounded down.
This macro behaves much like ARRAY_INDEX with the notable difference that it accepts any ptr
in the range of array
rather than exclusively a ptr
aligned to an array-element boundary of array
.
With CONFIG_ASSERT=y
, this macro will trigger a runtime assertion when ptr
does not fall into the range of array
.
In C, passing a pointer as array
causes a compile error.
array | the array in question |
ptr | pointer to an element of array |
ptr
within array
, on success #include <zephyr/sys/util.h>
Number of elements in the given array
.
In C++, due to language limitations, this will accept as array
any type that implements operator[]
. The results may not be particularly meaningful in this case.
In C, passing a pointer as array
causes a compile error.
#define BIT | ( | n | ) | (1UL << (n)) |
#include <zephyr/sys/util_macro.h>
Unsigned integer with bit position n
set (signed in assembly language).
#define BIT64 | ( | _n | ) | (1ULL << (_n)) |
#include <zephyr/sys/util_macro.h>
64-bit unsigned integer with bit position _n
set.
#define BIT64_MASK | ( | n | ) | (BIT64(n) - 1ULL) |
#include <zephyr/sys/util_macro.h>
64-bit bit mask with bits 0 through n-1
(inclusive) set, or 0 if n
is 0.
#define BIT_MASK | ( | n | ) | (BIT(n) - 1UL) |
#include <zephyr/sys/util_macro.h>
Bit mask with bits 0 through n-1
(inclusive) set, or 0 if n
is 0.
#define BITS_PER_LONG (__CHAR_BIT__ * __SIZEOF_LONG__) |
#include <zephyr/sys/util.h>
Number of bits in a long int.
#define BITS_PER_LONG_LONG (__CHAR_BIT__ * __SIZEOF_LONG_LONG__) |
#include <zephyr/sys/util.h>
Number of bits in a long long int.
#define ceiling_fraction | ( | numerator, | |
divider | |||
) |
#include <zephyr/sys/util.h>
Ceiling function applied to numerator
/ divider
as a fraction.
#define CLAMP | ( | val, | |
low, | |||
high | |||
) | (((val) <= (low)) ? (low) : MIN(val, high)) |
#include <zephyr/sys/util.h>
Clamp a value to a given range.
val | Value to be clamped. |
low | Lowest allowed value (inclusive). |
high | Highest allowed value (inclusive). |
#define CONCAT | ( | ... | ) | UTIL_CAT(_CONCAT_, NUM_VA_ARGS_LESS_1(__VA_ARGS__))(__VA_ARGS__) |
#include <zephyr/sys/util.h>
Concatenate input arguments.
Concatenate provided tokens into a combined token during the preprocessor pass. This can be used to, for ex., build an identifier out of multiple parts, where one of those parts may be, for ex, a number, another macro, or a macro argument.
... | Tokens to concatencate |
#define COND_CODE_0 | ( | _flag, | |
_if_0_code, | |||
_else_code | |||
) | Z_COND_CODE_0(_flag, _if_0_code, _else_code) |
#include <zephyr/sys/util_macro.h>
Like COND_CODE_1() except tests if _flag
is 0.
This is like COND_CODE_1(), except that it tests whether _flag
expands to the integer literal 0. It expands to _if_0_code
if so, and _else_code
otherwise; both of these must be enclosed in parentheses.
_flag | evaluated flag |
_if_0_code | result if _flag expands to 0; must be in parentheses |
_else_code | result otherwise; must be in parentheses |
#define COND_CODE_1 | ( | _flag, | |
_if_1_code, | |||
_else_code | |||
) | Z_COND_CODE_1(_flag, _if_1_code, _else_code) |
#include <zephyr/sys/util_macro.h>
Insert code depending on whether _flag
expands to 1 or not.
This relies on similar tricks as IS_ENABLED(), but as the result of _flag
expansion, results in either _if_1_code
or _else_code
is expanded.
To prevent the preprocessor from treating commas as argument separators, the _if_1_code
and _else_code
expressions must be inside brackets/parentheses: ()
. These are stripped away during macro expansion.
Example:
COND_CODE_1(CONFIG_FLAG, (uint32_t x;), (there_is_no_flag();))
If CONFIG_FLAG
is defined to 1, this expands to:
uint32_t x;
It expands to there_is_no_flag();
otherwise.
This could be used as an alternative to:
#if defined(CONFIG_FLAG) && (CONFIG_FLAG == 1) #define MAYBE_DECLARE(x) uint32_t x #else #define MAYBE_DECLARE(x) there_is_no_flag() #endif MAYBE_DECLARE(x);
However, the advantage of COND_CODE_1() is that code is resolved in place where it is used, while the #if
method defines MAYBE_DECLARE
on two lines and requires it to be invoked again on a separate line. This makes COND_CODE_1() more concise and also sometimes more useful when used within another macro's expansion.
_flag
can be the result of preprocessor expansion, e.g. an expression involving NUM_VA_ARGS_LESS_1(...)
. However, _if_1_code
is only expanded if _flag
expands to the integer literal 1. Integer expressions that evaluate to 1, e.g. after doing some arithmetic, will not work._flag | evaluated flag |
_if_1_code | result if _flag expands to 1; must be in parentheses |
_else_code | result otherwise; must be in parentheses |
#define CONTAINER_OF | ( | ptr, | |
type, | |||
field | |||
) |
#include <zephyr/sys/util.h>
Get a pointer to a structure containing the element.
Example:
struct foo { int bar; }; struct foo my_foo; int *ptr = &my_foo.bar; struct foo *container = CONTAINER_OF(ptr, struct foo, bar);
Above, container
points at my_foo
.
ptr | pointer to a structure element |
type | name of the type that ptr is an element of |
field | the name of the field within the struct ptr points to |
ptr
#define CONTAINER_OF_VALIDATE | ( | ptr, | |
type, | |||
field | |||
) |
#include <zephyr/sys/util.h>
Validate CONTAINER_OF parameters, only applies to C mode.
#define DIV_ROUND_CLOSEST | ( | n, | |
d | |||
) |
#include <zephyr/sys/util.h>
Divide and round to the nearest integer.
Example:
n | Numerator. |
d | Denominator. |
n
/ d
, rounded to the nearest integer. #include <zephyr/sys/util.h>
Divide and round up.
Example:
n | Numerator. |
d | Denominator. |
n
/ d
, rounded up. #define EMPTY |
#include <zephyr/sys/util_macro.h>
Macro with an empty expansion.
This trivial definition is provided for readability when a macro should expand to an empty result, which e.g. is sometimes needed to silence checkpatch.
Example:
#define LIST_ITEM(n) , item##n
The above would cause checkpatch to complain, but:
#define LIST_ITEM(n) EMPTY, item##n
would not.
#define FIELD_GET | ( | mask, | |
value | |||
) | (((value) & (mask)) / LSB_GET(mask)) |
#include <zephyr/sys/util.h>
Extract a bitfield element from value
corresponding to the field mask mask
.
#define FIELD_PREP | ( | mask, | |
value | |||
) | (((value) * LSB_GET(mask)) & (mask)) |
#include <zephyr/sys/util.h>
Prepare a bitfield element using value
with mask
representing its field position and width.
The result should be combined with other fields using a logical OR.
#define FOR_EACH | ( | F, | |
sep, | |||
... | |||
) | Z_FOR_EACH(F, sep, REVERSE_ARGS(__VA_ARGS__)) |
#include <zephyr/sys/util_macro.h>
Call a macro F
on each provided argument with a given separator between each call.
Example:
#define F(x) int a##x FOR_EACH(F, (;), 4, 5, 6);
This expands to:
int a4; int a5; int a6;
F | Macro to invoke |
sep | Separator (e.g. comma or semicolon). Must be in parentheses; this is required to enable providing a comma as separator. |
... | Variable argument list. The macro F is invoked as F(element) for each element in the list. |
#define FOR_EACH_FIXED_ARG | ( | F, | |
sep, | |||
fixed_arg, | |||
... | |||
) | Z_FOR_EACH_FIXED_ARG(F, sep, fixed_arg, REVERSE_ARGS(__VA_ARGS__)) |
#include <zephyr/sys/util_macro.h>
Call macro F
on each provided argument, with an additional fixed argument as a parameter.
This is like FOR_EACH(), except F
should be a macro which takes two arguments: F(variable_arg, fixed_arg)
.
Example:
static void func(int val, void *dev); FOR_EACH_FIXED_ARG(func, (;), dev, 4, 5, 6);
This expands to:
func(4, dev); func(5, dev); func(6, dev);
F | Macro to invoke |
sep | Separator (e.g. comma or semicolon). Must be in parentheses; this is required to enable providing a comma as separator. |
fixed_arg | Fixed argument passed to F as the second macro parameter. |
... | Variable argument list. The macro F is invoked as F(element, fixed_arg) for each element in the list. |
#define FOR_EACH_IDX | ( | F, | |
sep, | |||
... | |||
) | Z_FOR_EACH_IDX(F, sep, REVERSE_ARGS(__VA_ARGS__)) |
#include <zephyr/sys/util_macro.h>
Call macro F
on each provided argument, with the argument's index as an additional parameter.
This is like FOR_EACH(), except F
should be a macro which takes two arguments: F(index, variable_arg)
.
Example:
#define F(idx, x) int a##idx = x FOR_EACH_IDX(F, (;), 4, 5, 6);
This expands to:
int a0 = 4; int a1 = 5; int a2 = 6;
F | Macro to invoke |
sep | Separator (e.g. comma or semicolon). Must be in parentheses; this is required to enable providing a comma as separator. |
... | Variable argument list. The macro F is invoked as F(index, element) for each element in the list. |
#define FOR_EACH_IDX_FIXED_ARG | ( | F, | |
sep, | |||
fixed_arg, | |||
... | |||
) | Z_FOR_EACH_IDX_FIXED_ARG(F, sep, fixed_arg, REVERSE_ARGS(__VA_ARGS__)) |
#include <zephyr/sys/util_macro.h>
Calls macro F
for each variable argument with an index and fixed argument.
This is like the combination of FOR_EACH_IDX() with FOR_EACH_FIXED_ARG().
Example:
#define F(idx, x, fixed_arg) int fixed_arg##idx = x FOR_EACH_IDX_FIXED_ARG(F, (;), a, 4, 5, 6);
This expands to:
int a0 = 4; int a1 = 5; int a2 = 6;
F | Macro to invoke |
sep | Separator (e.g. comma or semicolon). Must be in parentheses; This is required to enable providing a comma as separator. |
fixed_arg | Fixed argument passed to F as the third macro parameter. |
... | Variable list of arguments. The macro F is invoked as F(index, element, fixed_arg) for each element in the list. |
#define FOR_EACH_NONEMPTY_TERM | ( | F, | |
term, | |||
... | |||
) |
#include <zephyr/sys/util_macro.h>
Like FOR_EACH(), but with a terminator instead of a separator, and drops empty elements from the argument list.
The sep
argument to FOR_EACH(F, (sep), a, b)
is a separator which is placed between calls to F
, like this:
FOR_EACH(F, (sep), a, b) // F(a) sep F(b) // ^^^ no sep here!
By contrast, the term
argument to FOR_EACH_NONEMPTY_TERM(F, (term),
a, b)
is added after each time F
appears in the expansion:
FOR_EACH_NONEMPTY_TERM(F, (term), a, b) // F(a) term F(b) term // ^^^^
Further, any empty elements are dropped:
FOR_EACH_NONEMPTY_TERM(F, (term), a, EMPTY, b) // F(a) term F(b) term
This is more convenient in some cases, because FOR_EACH_NONEMPTY_TERM() expands to nothing when given an empty argument list, and it's often cumbersome to write a macro F
that does the right thing even when given an empty argument.
One example is when __VA_ARGS__
may or may not be empty, and the results are embedded in a larger initializer:
#define SQUARE(x) ((x)*(x)) int my_array[] = { FOR_EACH_NONEMPTY_TERM(SQUARE, (,), FOO(...)) FOR_EACH_NONEMPTY_TERM(SQUARE, (,), BAR(...)) FOR_EACH_NONEMPTY_TERM(SQUARE, (,), BAZ(...)) };
This is more convenient than:
FOO
, BAR
, and BAZ
expansions are empty and adding a comma manually (or not) between FOR_EACH() callsFOO
expands to nothing)F | Macro to invoke on each nonempty element of the variable arguments |
term | Terminator (e.g. comma or semicolon) placed after each invocation of F. Must be in parentheses; this is required to enable providing a comma as separator. |
... | Variable argument list. The macro F is invoked as F(element) for each nonempty element in the list. |
#define GB | ( | x | ) | (MB(x) << 10) |
#include <zephyr/sys/util.h>
Number of bytes in x
gibibytes.
#define GENMASK | ( | h, | |
l | |||
) | (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h)))) |
#include <zephyr/sys/util.h>
Create a contiguous bitmask starting at bit position l
and ending at position h
.
#define GENMASK64 | ( | h, | |
l | |||
) | (((~0ULL) - (1ULL << (l)) + 1) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h)))) |
#include <zephyr/sys/util.h>
Create a contiguous 64-bit bitmask starting at bit position l
and ending at position h
.
#define GET_ARG_N | ( | N, | |
... | |||
) | Z_GET_ARG_##N(__VA_ARGS__) |
#include <zephyr/sys/util_macro.h>
Get nth argument from argument list.
N | Argument index to fetch. Counter from 1. |
... | Variable list of arguments from which one argument is returned. |
#define GET_ARGS_LESS_N | ( | N, | |
... | |||
) | Z_GET_ARGS_LESS_##N(__VA_ARGS__) |
#include <zephyr/sys/util_macro.h>
Strips n first arguments from the argument list.
N | Number of arguments to discard. |
... | Variable list of arguments. |
#define IDENTITY | ( | V | ) | V |
#include <zephyr/sys/util_macro.h>
Macro that expands to its argument.
This is useful in macros like FOR_EACH()
when there is no transformation required on the list elements.
V | any value |
#define IF_DISABLED | ( | _flag, | |
_code | |||
) | COND_CODE_1(_flag, (), _code) |
#include <zephyr/sys/util_macro.h>
Insert code if _flag
is not defined as 1.
This expands to nothing if _flag
is defined and equal to 1; it expands to _code
otherwise.
Example:
IF_DISABLED(CONFIG_FLAG, (uint32_t foo;))
If CONFIG_FLAG
isn't defined or different than 1, this expands to:
uint32_t foo;
and to nothing otherwise.
IF_DISABLED does the opposite of IF_ENABLED.
_flag | evaluated flag |
_code | result if _flag does not expand to 1; must be in parentheses |
#define IF_ENABLED | ( | _flag, | |
_code | |||
) | COND_CODE_1(_flag, _code, ()) |
#include <zephyr/sys/util_macro.h>
Insert code if _flag
is defined and equals 1.
Like COND_CODE_1(), this expands to _code
if _flag
is defined to 1; it expands to nothing otherwise.
Example:
IF_ENABLED(CONFIG_FLAG, (uint32_t foo;))
If CONFIG_FLAG
is defined to 1, this expands to:
uint32_t foo;
and to nothing otherwise.
It can be considered as a more compact alternative to:
#if defined(CONFIG_FLAG) && (CONFIG_FLAG == 1) uint32_t foo; #endif
_flag | evaluated flag |
_code | result if _flag expands to 1; must be in parentheses |
#define IN_RANGE | ( | val, | |
min, | |||
max | |||
) | ((val) >= (min) && (val) <= (max)) |
#include <zephyr/sys/util.h>
Checks if a value is within range.
val
is evaluated twice.val | Value to be checked. |
min | Lower bound (inclusive). |
max | Upper bound (inclusive). |
true | If value is within range |
false | If the value is not within range |
#define INT_TO_POINTER | ( | x | ) | ((void *) (intptr_t) (x)) |
#include <zephyr/sys/util.h>
Cast x
, a signed integer, to a void*
.
#define IS_ALIGNED | ( | ptr, | |
align | |||
) | (((uintptr_t)(ptr)) % (align) == 0) |
#include <zephyr/sys/util.h>
Check if ptr
is aligned to align
alignment.
#define IS_ARRAY | ( | array | ) |
#include <zephyr/sys/util.h>
Zero if array
has an array type, a compile error otherwise.
This macro is available only from C, not C++.
#define IS_ARRAY_ELEMENT | ( | array, | |
ptr | |||
) |
#include <zephyr/sys/util.h>
Whether ptr
is an element of array
.
This macro can be seen as a slightly stricter version of PART_OF_ARRAY in that it also ensures that ptr
is aligned to an array-element boundary of array
.
In C, passing a pointer as array
causes a compile error.
array | the array in question |
ptr | the pointer to check |
ptr
is part of array
, 0 otherwise #define IS_BIT_MASK | ( | m | ) | IS_SHIFTED_BIT_MASK(m, 0) |
#include <zephyr/sys/util_macro.h>
Check if bits are set continuously from the LSB.
m | Check whether the bits are set continuously from LSB. |
#define IS_EMPTY | ( | ... | ) | Z_IS_EMPTY_(__VA_ARGS__) |
#include <zephyr/sys/util_macro.h>
Check if a macro has a replacement expression.
If a
is a macro defined to a nonempty value, this will return true, otherwise it will return false. It only works with defined macros, so an additional #ifdef
test may be needed in some cases.
This macro may be used with COND_CODE_1() and COND_CODE_0() while processing __VA_ARGS__
to avoid processing empty arguments.
Example:
#define EMPTY #define NON_EMPTY 1 #undef UNDEFINED IS_EMPTY(EMPTY) IS_EMPTY(NON_EMPTY) IS_EMPTY(UNDEFINED) #if defined(EMPTY) && IS_EMPTY(EMPTY) == true some_conditional_code #endif
In above examples, the invocations of IS_EMPTY(...) return true
, false
, and true
; some_conditional_code
is included.
... | macro to check for emptiness (may be __VA_ARGS__ ) |
#define IS_ENABLED | ( | config_macro | ) | Z_IS_ENABLED1(config_macro) |
#include <zephyr/sys/util_macro.h>
Check for macro definition in compiler-visible expressions.
This trick was pioneered in Linux as the config_enabled() macro. It has the effect of taking a macro value that may be defined to "1" or may not be defined at all and turning it into a literal expression that can be handled by the C compiler instead of just the preprocessor. It is often used with a CONFIG_FOO
macro which may be defined to 1 via Kconfig, or left undefined.
That is, it works similarly to #if defined(CONFIG_FOO)
except that its expansion is a C expression. Thus, much #ifdef
usage can be replaced with equivalents like:
if (IS_ENABLED(CONFIG_FOO)) { do_something_with_foo }
This is cleaner since the compiler can generate errors and warnings for do_something_with_foo
even when CONFIG_FOO
is undefined.
Note: Use of IS_ENABLED in a #if
statement is discouraged as it doesn't provide any benefit vs plain #if defined()
config_macro | Macro to check |
config_macro
is defined to 1, 0 otherwise (including if config_macro
is not defined) #define IS_EQ | ( | a, | |
b | |||
) | Z_IS_EQ(a, b) |
#include <zephyr/sys/util_macro.h>
Like a == b
, but does evaluation and short-circuiting at C preprocessor time.
This however only works for integer literal from 0 to 4095.
#define IS_POWER_OF_TWO | ( | x | ) | (((x) != 0U) && (((x) & ((x) - 1U)) == 0U)) |
#include <zephyr/sys/util_macro.h>
Check if a x
is a power of two.
#include <zephyr/sys/util_macro.h>
Check if bits are set continuously from the specified bit.
The macro is not dependent on the bit-width.
m | Check whether the bits are set continuously or not. |
s | Specify the lowest bit for that is continuously set bits. |
#define KB | ( | x | ) | ((x) << 10) |
#include <zephyr/sys/util.h>
Number of bytes in x
kibibytes.
#define KHZ | ( | x | ) | ((x) * 1000) |
#include <zephyr/sys/util.h>
Number of Hz in x
kHz.
#define LIST_DROP_EMPTY | ( | ... | ) | Z_LIST_DROP_FIRST(FOR_EACH(Z_LIST_NO_EMPTIES, (), __VA_ARGS__)) |
#include <zephyr/sys/util_macro.h>
Remove empty arguments from list.
During macro expansion, __VA_ARGS__
and other preprocessor generated lists may contain empty elements, e.g.:
#define LIST ,a,b,,d,
Using EMPTY to show each empty element, LIST contains:
EMPTY, a, b, EMPTY, d
When processing such lists, e.g. using FOR_EACH(), all empty elements will be processed, and may require filtering out. To make that process easier, it is enough to invoke LIST_DROP_EMPTY which will remove all empty elements.
Example:
LIST_DROP_EMPTY(LIST)
expands to:
a, b, d
... | list to be processed |
#define LISTIFY | ( | LEN, | |
F, | |||
sep, | |||
... | |||
) | UTIL_CAT(Z_UTIL_LISTIFY_, LEN)(F, sep, __VA_ARGS__) |
#include <zephyr/sys/util_macro.h>
Generates a sequence of code with configurable separator.
Example:
#define FOO(i, _) MY_PWM ## i { LISTIFY(PWM_COUNT, FOO, (,)) }
The above two lines expand to:
{ MY_PWM0 , MY_PWM1 }
LEN | The length of the sequence. Must be an integer literal less than 4095. |
F | A macro function that accepts at least two arguments: F(i, ...) . F is called repeatedly in the expansion. Its first argument i is the index in the sequence, and the variable list of arguments passed to LISTIFY are passed through to F . |
sep | Separator (e.g. comma or semicolon). Must be in parentheses; this is required to enable providing a comma as separator. |
#define LOG2 | ( | x | ) | ((x) < 1 ? -1 : __z_log2(x)) |
#include <zephyr/sys/util.h>
Compute log2(x)
x | An unsigned integral value to compute logarithm of (positive only) |
#define LOG2CEIL | ( | x | ) | ((x) < 1 ? 0 : __z_log2((x)-1) + 1) |
#include <zephyr/sys/util.h>
Compute ceil(log2(x))
x | An unsigned integral value |
#define LSB_GET | ( | value | ) | ((value) & -(value)) |
#include <zephyr/sys/util.h>
Extract the Least Significant Bit from value
.
#define MACRO_MAP_CAT | ( | ... | ) | MACRO_MAP_CAT_(__VA_ARGS__) |
#include <zephyr/sys/util_macro.h>
Mapping macro that pastes results together.
This is similar to FOR_EACH() in that it invokes a macro repeatedly on each element of __VA_ARGS__
. However, unlike FOR_EACH(), MACRO_MAP_CAT() pastes the results together into a single token.
For example, with this macro FOO:
#define FOO(x) item_##x##_
MACRO_MAP_CAT(FOO, a, b, c),
expands to the token:
item_a_item_b_item_c_
... | Macro to expand on each argument, followed by its arguments. (The macro should take exactly one argument.) |
#define MACRO_MAP_CAT_N | ( | N, | |
... | |||
) | MACRO_MAP_CAT_N_(N, __VA_ARGS__) |
#include <zephyr/sys/util_macro.h>
Mapping macro that pastes a fixed number of results together.
Similar to MACRO_MAP_CAT(), but expects a fixed number of arguments. If more arguments are given than are expected, the rest are ignored.
N | Number of arguments to map |
... | Macro to expand on each argument, followed by its arguments. (The macro should take exactly one argument.) |
#define MAX | ( | a, | |
b | |||
) | (((a) > (b)) ? (a) : (b)) |
#include <zephyr/sys/util.h>
Obtain the maximum of two values.
a | First value. |
b | Second value. |
a
and b
. #define MB | ( | x | ) | (KB(x) << 10) |
#include <zephyr/sys/util.h>
Number of bytes in x
mebibytes.
#define MHZ | ( | x | ) | (KHZ(x) * 1000) |
#include <zephyr/sys/util.h>
Number of Hz in x
MHz.
#define MIN | ( | a, | |
b | |||
) | (((a) < (b)) ? (a) : (b)) |
#include <zephyr/sys/util.h>
Obtain the minimum of two values.
a | First value. |
b | Second value. |
a
and b
. #define NHPOT | ( | x | ) | ((x) < 1 ? 1 : ((x) > (1ULL<<63) ? 0 : 1ULL << LOG2CEIL(x))) |
#include <zephyr/sys/util.h>
Compute next highest power of two.
Equivalent to 2^ceil(log2(x))
x | An unsigned integral value |
#define NUM_VA_ARGS | ( | ... | ) | COND_CODE_1(IS_EMPTY(__VA_ARGS__), (0), (UTIL_INC(NUM_VA_ARGS_LESS_1(__VA_ARGS__)))) |
#include <zephyr/sys/util_macro.h>
Number of arguments in the variable arguments list.
... | List of arguments |
#define NUM_VA_ARGS_LESS_1 | ( | ... | ) |
#include <zephyr/sys/util_macro.h>
Number of arguments in the variable arguments list minus one.
... | List of arguments |
#define PART_OF_ARRAY | ( | array, | |
ptr | |||
) |
#include <zephyr/sys/util.h>
Check if a pointer ptr
lies within array
.
In C but not C++, this causes a compile error if array
is not an array (e.g. if ptr
and array
are mixed up).
array | an array |
ptr | a pointer |
ptr
is part of array
, 0 otherwise #define POINTER_TO_INT | ( | x | ) | ((intptr_t) (x)) |
#include <zephyr/sys/util.h>
Cast x
, a pointer, to a signed integer.
#define POINTER_TO_UINT | ( | x | ) | ((uintptr_t) (x)) |
#include <zephyr/sys/util.h>
Cast x
, a pointer, to an unsigned integer.
#define REVERSE_ARGS | ( | ... | ) | Z_FOR_EACH_ENGINE(Z_FOR_EACH_EXEC, (,), Z_BYPASS, _, __VA_ARGS__) |
#define ROUND_DOWN | ( | x, | |
align | |||
) | (((unsigned long)(x) / (unsigned long)(align)) * (unsigned long)(align)) |
#include <zephyr/sys/util.h>
Value of x
rounded down to the previous multiple of align
.
#define ROUND_UP | ( | x, | |
align | |||
) |
#include <zephyr/sys/util.h>
Value of x
rounded up to the next multiple of align
.
#define SAME_TYPE | ( | a, | |
b | |||
) | __builtin_types_compatible_p(__typeof__(a), __typeof__(b)) |
#include <zephyr/sys/util.h>
Validate if two entities have a compatible type.
a | the first entity to be compared |
b | the second entity to be compared |
#define SIZEOF_FIELD | ( | type, | |
member | |||
) | sizeof((((type *)0)->member)) |
#include <zephyr/sys/util.h>
Report the size of a struct field in bytes.
type | The structure containing the field of interest. |
member | The field to return the size of. |
#define UINT_TO_POINTER | ( | x | ) | ((void *) (uintptr_t) (x)) |
#include <zephyr/sys/util.h>
Cast x
, an unsigned integer, to a void*
.
#define UTIL_AND | ( | a, | |
b | |||
) | COND_CODE_1(UTIL_BOOL(a), (b), (0)) |
#include <zephyr/sys/util_macro.h>
Like a && b
, but does evaluation and short-circuiting at C preprocessor time.
This is not the same as the binary &&
, however; in particular, a
should expand to an integer literal 0 or 1. However, b
can be any value.
This can be useful when b
is an expression that would cause a build error when a
is 0.
#define UTIL_DEC | ( | x | ) | UTIL_PRIMITIVE_CAT(Z_UTIL_DEC_, x) |
#include <zephyr/sys/util_macro.h>
UTIL_DEC(x) for an integer literal x from 0 to 4095 expands to an integer literal whose value is x-1.
#define UTIL_INC | ( | x | ) | UTIL_PRIMITIVE_CAT(Z_UTIL_INC_, x) |
#include <zephyr/sys/util_macro.h>
UTIL_INC(x) for an integer literal x from 0 to 4095 expands to an integer literal whose value is x+1.
#define UTIL_OR | ( | a, | |
b | |||
) | COND_CODE_1(UTIL_BOOL(a), (a), (b)) |
#include <zephyr/sys/util_macro.h>
Like a || b
, but does evaluation and short-circuiting at C preprocessor time.
This is not the same as the binary ||
operator; in particular, a
should expand to an integer literal 0 or 1. However, b
can be any value.
This can be useful when b
is an expression that would cause a build error when a
is 1.
#define UTIL_X2 | ( | y | ) | UTIL_PRIMITIVE_CAT(Z_UTIL_X2_, y) |
#include <zephyr/sys/util_macro.h>
UTIL_X2(y) for an integer literal y from 0 to 4095 expands to an integer literal whose value is 2y.
#define WAIT_FOR | ( | expr, | |
timeout, | |||
delay_stmt | |||
) |
#include <zephyr/sys/util.h>
Wait for an expression to return true with a timeout.
Spin on an expression with a timeout and optional delay between iterations
Commonly needed when waiting on hardware to complete an asynchronous request to read/write/initialize/reset, but useful for any expression.
expr | Truth expression upon which to poll, e.g.: XYZREG & XYZREG_EN |
timeout | Timeout to wait for in microseconds, e.g.: 1000 (1ms) |
delay_stmt | Delay statement to perform each poll iteration e.g.: NULL, k_yield(), k_msleep(1) or k_busy_wait(1) |
expr | As a boolean return, if false then it has timed out. |
#define WB_DN | ( | x | ) | ROUND_DOWN(x, sizeof(void *)) |
#include <zephyr/sys/util.h>
Value of x
rounded down to the previous word boundary.
#include <zephyr/sys/util.h>
Value of x
rounded up to the next word boundary.
#include <zephyr/sys/util_macro.h>
Set or clear a bit depending on a boolean value.
The argument var
is a variable whose value is written to as a side effect.
var | Variable to be altered |
bit | Bit number |
set | if 0, clears bit in var ; any other value sets bit |
#define ZERO_OR_COMPILE_ERROR | ( | cond | ) | ((int) sizeof(char[1 - 2 * !(cond)]) - 1) |
#include <zephyr/sys/util.h>
0 if cond
is true-ish; causes a compile error otherwise.
#include <zephyr/sys/util.h>
Arithmetic shift right.
value | value to shift |
shift | number of bits to shift |
value
shifted right by shift
; opened bit positions are filled with the sign bit #include <zephyr/sys/util.h>
Convert a binary coded decimal (BCD 8421) value to binary.
bcd | BCD 8421 value to convert. |
#include <zephyr/sys/util.h>
Convert a binary value to binary coded decimal (BCD 8421).
bin | Binary value to convert. |
#include <zephyr/sys/util.h>
Convert a binary array into string representation.
buf | The binary array to convert |
buflen | The length of the binary array to convert |
hex | Address of where to store the string representation. |
hexlen | Size of the storage area for string representation. |
|
inlinestatic |
#include <zephyr/sys/util.h>
byte by byte memcpy.
Copy size
bytes of src
into dest
. This is guaranteed to be done byte by byte.
dst | Pointer to the destination memory. |
src | Pointer to the source of the data. |
size | The number of bytes to copy. |
|
inlinestatic |
#include <zephyr/sys/util.h>
byte by byte swap.
Swap size bytes between memory regions a and b. This is guaranteed to be done byte by byte.
a | Pointer to the first memory region. |
b | Pointer to the second memory region. |
size | The number of bytes to swap. |
int char2hex | ( | char | c, |
uint8_t * | x | ||
) |
#include <zephyr/sys/util.h>
Convert a single character into a hexadecimal nibble.
c | The character to convert |
x | The address of storage for the converted number. |
#include <zephyr/sys/util.h>
Convert a hexadecimal string into a binary array.
hex | The hexadecimal string to convert |
hexlen | The length of the hexadecimal string to convert. |
buf | Address of where to store the binary data |
buflen | Size of the storage area for binary data |
int hex2char | ( | uint8_t | x, |
char * | c | ||
) |
#include <zephyr/sys/util.h>
Convert a single hexadecimal nibble into a character.
c | The number to convert |
x | The address of storage for the converted character. |
|
static |
#include <zephyr/sys/util.h>
Is p
equal to NULL
?
Some macros may need to check their arguments against NULL to support multiple use-cases, but NULL checks can generate warnings if such a macro is used in contexts where that particular argument can never be NULL.
The warnings can be triggered if: a) all macros are expanded (e.g. when using CONFIG_COMPILER_SAVE_TEMPS=y) or b) tracking of macro expansions are turned off (-ftrack-macro-expansion=0)
The warnings can be circumvented by using this inline function for doing the NULL check within the macro. The compiler is still able to optimize the NULL check out at a later stage.
p | Pointer to check |
p
is equal to NULL
, false otherwise #include <zephyr/sys/util.h>
Is x
a power of two?
x | value to check |
x
is a power of two, false otherwise
|
inlinestatic |
#include <zephyr/sys/util.h>
XOR 128 bits.
dst | Destination of where to store result. Shall be 128 bits. |
src1 | First source. Shall be 128 bits. |
src2 | Second source. Shall be 128 bits. |
|
inlinestatic |
#include <zephyr/sys/util.h>
XOR 32 bits.
dst | Destination of where to store result. Shall be 32 bits. |
src1 | First source. Shall be 32 bits. |
src2 | Second source. Shall be 32 bits. |
|
inlinestatic |
#include <zephyr/sys/util.h>
XOR n bytes.
dst | Destination of where to store result. Shall be len bytes. |
src1 | First source. Shall be len bytes. |
src2 | Second source. Shall be len bytes. |
len | Number of bytes to XOR. |
#include <zephyr/sys/util.h>
Sign extend an 8, 16 or 32 bit value using the index bit as sign bit.
value | The value to sign expand. |
index | 0 based bit index to sign bit (0 to 31) |
#include <zephyr/sys/util.h>
Sign extend a 64 bit value using the index bit as sign bit.
value | The value to sign expand. |
index | 0 based bit index to sign bit (0 to 63) |
#include <zephyr/sys/util.h>
Convert a uint8_t into a decimal string representation.
Convert a uint8_t value into its ASCII decimal string representation. The string is terminated if there is enough space in buf.
buf | Address of where to store the string representation. |
buflen | Size of the storage area for string representation. |
value | The value to convert to decimal string |
char * utf8_lcpy | ( | char * | dst, |
const char * | src, | ||
size_t | n | ||
) |
#include <zephyr/sys/util.h>
Copies a UTF-8 encoded string from src
to dst
.
The resulting dst
will always be NULL terminated if n
is larger than 0, and the dst
string will always be properly UTF-8 truncated.
dst | The destination of the UTF-8 string. |
src | The source string |
n | The size of the dst buffer. Maximum number of characters copied is n - 1. If 0 nothing will be done, and the dst will not be NULL terminated. |
dst
char * utf8_trunc | ( | char * | utf8_str | ) |
#include <zephyr/sys/util.h>
Properly truncate a NULL-terminated UTF-8 string.
Take a NULL-terminated UTF-8 string and ensure that if the string has been truncated (by setting the NULL terminator) earlier by other means, that the string ends with a properly formatted UTF-8 character (1-4 bytes).
Example: char test_str[] = "€€€"; char trunc_utf8[8]; printf("Original : %s\n", test_str); // €€€ strncpy(trunc_utf8, test_str, sizeof(trunc_utf8)); trunc_utf8[sizeof(trunc_utf8) - 1] = '\0'; printf("Bad : %s\n", trunc_utf8); // €€� utf8_trunc(trunc_utf8); printf("Truncated: %s\n", trunc_utf8); // €€
utf8_str | NULL-terminated string |
utf8_str