/* * Copyright (c) 2011-2014, Wind River Systems, Inc. * * SPDX-License-Identifier: Apache-2.0 */ /** * @file * @brief Misc utilities * * Misc utilities usable by the kernel and application code. */ #ifndef _UTIL__H_ #define _UTIL__H_ #ifdef __cplusplus extern "C" { #endif #ifndef _ASMLANGUAGE #include /* Helper to pass a int as a pointer or vice-versa. * Those are available for 32 bits architectures: */ #define POINTER_TO_UINT(x) ((u32_t) (x)) #define UINT_TO_POINTER(x) ((void *) (x)) #define POINTER_TO_INT(x) ((s32_t) (x)) #define INT_TO_POINTER(x) ((void *) (x)) /* Evaluates to 0 if cond is true-ish; compile error otherwise */ #define ZERO_OR_COMPILE_ERROR(cond) ((int) sizeof(char[1 - 2 * !(cond)]) - 1) /* Evaluates to 0 if array is an array; compile error if not array (e.g. * pointer) */ #define IS_ARRAY(array) \ ZERO_OR_COMPILE_ERROR( \ !__builtin_types_compatible_p(__typeof__(array), \ __typeof__(&(array)[0]))) /* Evaluates to number of elements in an array; compile error if not * an array (e.g. pointer) */ #define ARRAY_SIZE(array) \ ((unsigned long) (IS_ARRAY(array) + \ (sizeof(array) / sizeof((array)[0])))) /* Evaluates to 1 if ptr is part of array, 0 otherwise; compile error if * "array" argument is not an array (e.g. "ptr" and "array" mixed up) */ #define PART_OF_ARRAY(array, ptr) \ ((ptr) && ((ptr) >= &array[0] && (ptr) < &array[ARRAY_SIZE(array)])) #define CONTAINER_OF(ptr, type, field) \ ((type *)(((char *)(ptr)) - offsetof(type, field))) /* round "x" up/down to next multiple of "align" (which must be a power of 2) */ #define ROUND_UP(x, align) \ (((unsigned long)(x) + ((unsigned long)align - 1)) & \ ~((unsigned long)align - 1)) #define ROUND_DOWN(x, align) ((unsigned long)(x) & ~((unsigned long)align - 1)) #define ceiling_fraction(numerator, divider) \ (((numerator) + ((divider) - 1)) / (divider)) #ifdef INLINED #define INLINE inline #else #define INLINE #endif #ifndef max #define max(a, b) (((a) > (b)) ? (a) : (b)) #endif #ifndef min #define min(a, b) (((a) < (b)) ? (a) : (b)) #endif static inline int is_power_of_two(unsigned int x) { return (x != 0) && !(x & (x - 1)); } static inline s64_t arithmetic_shift_right(s64_t value, u8_t shift) { s64_t sign_ext; if (shift == 0) { return value; } /* extract sign bit */ sign_ext = (value >> 63) & 1; /* make all bits of sign_ext be the same as the value's sign bit */ sign_ext = -sign_ext; /* shift value and fill opened bit positions with sign bit */ return (value >> shift) | (sign_ext << (64 - shift)); } #endif /* !_ASMLANGUAGE */ /* KB, MB, GB */ #define KB(x) ((x) << 10) #define MB(x) (KB(x) << 10) #define GB(x) (MB(x) << 10) /* KHZ, MHZ */ #define KHZ(x) ((x) * 1000) #define MHZ(x) (KHZ(x) * 1000) #ifndef BIT #define BIT(n) (1UL << (n)) #endif #define BIT_MASK(n) (BIT(n) - 1) /** * @brief Check for macro definition in compiler-visible expressions * * This trick was pioneered in Linux as the config_enabled() macro. * The madness has the effect of taking a macro value that may be * defined to "1" (e.g. CONFIG_MYFEATURE), or may not be defined at * all and turning it into a literal expression that can be used at * "runtime". That is, it works similarly to * "defined(CONFIG_MYFEATURE)" does except that it is an expansion * that can exist in a standard expression and be seen by the compiler * and optimizer. Thus much ifdef usage can be replaced with cleaner * expressions like: * * if (IS_ENABLED(CONFIG_MYFEATURE)) * myfeature_enable(); * * INTERNAL * First pass just to expand any existing macros, we need the macro * value to be e.g. a literal "1" at expansion time in the next macro, * not "(1)", etc... Standard recursive expansion does not work. */ #define IS_ENABLED(config_macro) _IS_ENABLED1(config_macro) /* Now stick on a "_XXXX" prefix, it will now be "_XXXX1" if config_macro * is "1", or just "_XXXX" if it's undefined. * ENABLED: _IS_ENABLED2(_XXXX1) * DISABLED _IS_ENABLED2(_XXXX) */ #define _IS_ENABLED1(config_macro) _IS_ENABLED2(_XXXX##config_macro) /* Here's the core trick, we map "_XXXX1" to "_YYYY," (i.e. a string * with a trailing comma), so it has the effect of making this a * two-argument tuple to the preprocessor only in the case where the * value is defined to "1" * ENABLED: _YYYY, <--- note comma! * DISABLED: _XXXX */ #define _XXXX1 _YYYY, /* Then we append an extra argument to fool the gcc preprocessor into * accepting it as a varargs macro. * arg1 arg2 arg3 * ENABLED: _IS_ENABLED3(_YYYY, 1, 0) * DISABLED _IS_ENABLED3(_XXXX 1, 0) */ #define _IS_ENABLED2(one_or_two_args) _IS_ENABLED3(one_or_two_args 1, 0) /* And our second argument is thus now cooked to be 1 in the case * where the value is defined to 1, and 0 if not: */ #define _IS_ENABLED3(ignore_this, val, ...) val /** * Macros for doing code-generation with the preprocessor. * * Generally it is better to generate code with the preprocessor than * to copy-paste code or to generate code with the build system / * python script's etc. * * http://stackoverflow.com/a/12540675 */ #define UTIL_EMPTY(...) #define UTIL_DEFER(...) __VA_ARGS__ UTIL_EMPTY() #define UTIL_OBSTRUCT(...) __VA_ARGS__ UTIL_DEFER(UTIL_EMPTY)() #define UTIL_EXPAND(...) __VA_ARGS__ #define UTIL_EVAL(...) UTIL_EVAL1(UTIL_EVAL1(UTIL_EVAL1(__VA_ARGS__))) #define UTIL_EVAL1(...) UTIL_EVAL2(UTIL_EVAL2(UTIL_EVAL2(__VA_ARGS__))) #define UTIL_EVAL2(...) UTIL_EVAL3(UTIL_EVAL3(UTIL_EVAL3(__VA_ARGS__))) #define UTIL_EVAL3(...) UTIL_EVAL4(UTIL_EVAL4(UTIL_EVAL4(__VA_ARGS__))) #define UTIL_EVAL4(...) UTIL_EVAL5(UTIL_EVAL5(UTIL_EVAL5(__VA_ARGS__))) #define UTIL_EVAL5(...) __VA_ARGS__ #define UTIL_CAT(a, ...) UTIL_PRIMITIVE_CAT(a, __VA_ARGS__) #define UTIL_PRIMITIVE_CAT(a, ...) a##__VA_ARGS__ #define UTIL_INC(x) UTIL_PRIMITIVE_CAT(UTIL_INC_, x) #define UTIL_INC_0 1 #define UTIL_INC_1 2 #define UTIL_INC_2 3 #define UTIL_INC_3 4 #define UTIL_INC_4 5 #define UTIL_INC_5 6 #define UTIL_INC_6 7 #define UTIL_INC_7 8 #define UTIL_INC_8 9 #define UTIL_INC_9 10 #define UTIL_INC_10 11 #define UTIL_INC_11 12 #define UTIL_INC_12 13 #define UTIL_INC_13 14 #define UTIL_INC_14 15 #define UTIL_INC_15 16 #define UTIL_INC_16 17 #define UTIL_INC_17 18 #define UTIL_INC_18 19 #define UTIL_INC_19 19 #define UTIL_DEC(x) UTIL_PRIMITIVE_CAT(UTIL_DEC_, x) #define UTIL_DEC_0 0 #define UTIL_DEC_1 0 #define UTIL_DEC_2 1 #define UTIL_DEC_3 2 #define UTIL_DEC_4 3 #define UTIL_DEC_5 4 #define UTIL_DEC_6 5 #define UTIL_DEC_7 6 #define UTIL_DEC_8 7 #define UTIL_DEC_9 8 #define UTIL_DEC_10 9 #define UTIL_DEC_11 10 #define UTIL_DEC_12 11 #define UTIL_DEC_13 12 #define UTIL_DEC_14 13 #define UTIL_DEC_15 14 #define UTIL_DEC_16 15 #define UTIL_DEC_17 16 #define UTIL_DEC_18 17 #define UTIL_DEC_19 18 #define UTIL_CHECK_N(x, n, ...) n #define UTIL_CHECK(...) UTIL_CHECK_N(__VA_ARGS__, 0,) #define UTIL_NOT(x) UTIL_CHECK(UTIL_PRIMITIVE_CAT(UTIL_NOT_, x)) #define UTIL_NOT_0 ~, 1, #define UTIL_COMPL(b) UTIL_PRIMITIVE_CAT(UTIL_COMPL_, b) #define UTIL_COMPL_0 1 #define UTIL_COMPL_1 0 #define UTIL_BOOL(x) UTIL_COMPL(UTIL_NOT(x)) #define UTIL_IIF(c) UTIL_PRIMITIVE_CAT(UTIL_IIF_, c) #define UTIL_IIF_0(t, ...) __VA_ARGS__ #define UTIL_IIF_1(t, ...) t #define UTIL_IF(c) UTIL_IIF(UTIL_BOOL(c)) #define UTIL_EAT(...) #define UTIL_EXPAND(...) __VA_ARGS__ #define UTIL_WHEN(c) UTIL_IF(c)(UTIL_EXPAND, UTIL_EAT) #define UTIL_REPEAT(count, macro, ...) \ UTIL_WHEN(count) \ ( \ UTIL_OBSTRUCT(UTIL_REPEAT_INDIRECT) () \ ( \ UTIL_DEC(count), macro, __VA_ARGS__ \ ) \ UTIL_OBSTRUCT(macro) \ ( \ UTIL_DEC(count), __VA_ARGS__ \ ) \ ) #define UTIL_REPEAT_INDIRECT() UTIL_REPEAT /** * Generates a sequence of code. * Useful for generating code like; * * NRF_PWM0, NRF_PWM1, NRF_PWM2, * * @arg LEN: The length of the sequence. Must be defined and less than * 20. * * @arg F(i, F_ARG): A macro function that accepts two arguments. * F is called repeatedly, the first argument * is the index in the sequence, and the second argument is the third * argument given to UTIL_LISTIFY. * * Example: * * \#define FOO(i, _) NRF_PWM ## i , * { UTIL_LISTIFY(PWM_COUNT, FOO) } * // The above two lines will generate the below: * { NRF_PWM0 , NRF_PWM1 , } * * @note Calling UTIL_LISTIFY with undefined arguments has undefined * behaviour. */ #define UTIL_LISTIFY(LEN, F, F_ARG) UTIL_EVAL(UTIL_REPEAT(LEN, F, F_ARG)) #ifdef __cplusplus } #endif #endif /* _UTIL__H_ */