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include: sys: util: Move macros from util to util_macro

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The <sys/util.h>, in current form, can not be used with DTS as it
contains non-C pre-processor definitions which breake DTS interpreter.
This commit fixes the problem by moving most of preprocessor macros
from util.h to util_macro.h.  Since util_mcaro.h contains only
preprocessor macros, without include dependencies, it can be safely
included in DTS. It is similar way the
<dts/arm/<manufacturer>/pinctrl_<manufacturer>_<soc>.h files are
included.

This fix and align the extern "C" closing brack inside non assembly
block.

The issue was raised when try create a macro for pincrtl with a
variable length flag list.

Signed-off-by: Gerson Fernando Budke <nandojve@gmail.com>
This commit is contained in:
Gerson Fernando Budke 2020-09-24 12:02:46 -03:00 • committed by Kumar Gala
commit 6b05121e65
2 changed files with 590 additions and 556 deletions
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562
include/sys/util.h
View file

@ -14,18 +14,13 @@
#ifndef ZEPHYR_INCLUDE_SYS_UTIL_H_ #ifndef ZEPHYR_INCLUDE_SYS_UTIL_H_
#define ZEPHYR_INCLUDE_SYS_UTIL_H_ #define ZEPHYR_INCLUDE_SYS_UTIL_H_
#include <sys/util_macro.h>
/* needs to be outside _ASMLANGUAGE so 'true' and 'false' can turn /* needs to be outside _ASMLANGUAGE so 'true' and 'false' can turn
* into '1' and '0' for asm or linker scripts * into '1' and '0' for asm or linker scripts
*/ */
#include <stdbool.h> #include <stdbool.h>
/*
* Most of the eldritch implementation details for all the macrobatics
* below (APIs like IS_ENABLED(), COND_CODE_1(), etc.) are hidden away
* in this file.
*/
#include "util_internal.h"
#ifndef _ASMLANGUAGE #ifndef _ASMLANGUAGE
#include <zephyr/types.h> #include <zephyr/types.h>
@ -277,6 +272,10 @@ size_t hex2bin(const char *hex, size_t hexlen, uint8_t *buf, size_t buflen);
*/ */
uint8_t u8_to_dec(char *buf, uint8_t buflen, uint8_t value); uint8_t u8_to_dec(char *buf, uint8_t buflen, uint8_t value);
#ifdef __cplusplus
}
#endif
#endif /* !_ASMLANGUAGE */ #endif /* !_ASMLANGUAGE */
/** @brief Number of bytes in @p x kibibytes */ /** @brief Number of bytes in @p x kibibytes */
@ -330,557 +329,8 @@ uint8_t u8_to_dec(char *buf, uint8_t buflen, uint8_t value);
*/ */
#define BIT_MASK(n) (BIT(n) - 1) #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. 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 @p CONFIG_FOO macro which
* may be defined to 1 via Kconfig, or left undefined.
*
* That is, it works similarly to <tt>\#if defined(CONFIG_FOO)</tt>
* except that its expansion is a C expression. Thus, much <tt>\#ifdef</tt>
* 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 @p do_something_with_foo even when @p CONFIG_FOO is undefined.
*
* @param config_macro Macro to check
* @return 1 if @p config_macro is defined to 1, 0 otherwise (including
* if @p config_macro is not defined)
*/
#define IS_ENABLED(config_macro) Z_IS_ENABLED1(config_macro)
/* INTERNAL: the first pass above is 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.
*/
/**
* @brief Insert code depending on whether @p _flag expands to 1 or not.
*
* This relies on similar tricks as IS_ENABLED(), but as the result of
* @p _flag expansion, results in either @p _if_1_code or @p
* _else_code is expanded.
*
* To prevent the preprocessor from treating commas as argument
* separators, the @p _if_1_code and @p _else_code expressions must be
* inside brackets/parentheses: <tt>()</tt>. These are stripped away
* during macro expansion.
*
* Example:
*
* COND_CODE_1(CONFIG_FLAG, (uint32_t x;), (there_is_no_flag();))
*
* If @p CONFIG_FLAG is defined to 1, this expands to:
*
* uint32_t x;
*
* It expands to <tt>there_is_no_flag();</tt> 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 @p \#if method defines @p
* 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.
*
* @note @p _flag can be the result of preprocessor expansion, e.g.
* an expression involving <tt>NUM_VA_ARGS_LESS_1(...)</tt>.
* However, @p _if_1_code is only expanded if @p _flag expands
* to the integer literal 1. Integer expressions that evaluate
* to 1, e.g. after doing some arithmetic, will not work.
*
* @param _flag evaluated flag
* @param _if_1_code result if @p _flag expands to 1; must be in parentheses
* @param _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)
/**
* @brief Like COND_CODE_1() except tests if @p _flag is 0.
*
* This is like COND_CODE_1(), except that it tests whether @p _flag
* expands to the integer literal 0. It expands to @p _if_0_code if
* so, and @p _else_code otherwise; both of these must be enclosed in
* parentheses.
*
* @param _flag evaluated flag
* @param _if_0_code result if @p _flag expands to 0; must be in parentheses
* @param _else_code result otherwise; must be in parentheses
* @see COND_CODE_1()
*/
#define COND_CODE_0(_flag, _if_0_code, _else_code) \
Z_COND_CODE_0(_flag, _if_0_code, _else_code)
/**
* @brief Insert code if @p _flag is defined and equals 1.
*
* Like COND_CODE_1(), this expands to @p _code if @p _flag is defined to 1;
* it expands to nothing otherwise.
*
* Example:
*
* IF_ENABLED(CONFIG_FLAG, (uint32_t foo;))
*
* If @p 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
*
* @param _flag evaluated flag
* @param _code result if @p _flag expands to 1; must be in parentheses
*/
#define IF_ENABLED(_flag, _code) \
COND_CODE_1(_flag, _code, ())
/**
* @brief Check if a macro has a replacement expression
*
* If @p 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 @p \#ifdef test may be needed in some cases.
*
* This macro may be used with COND_CODE_1() and COND_CODE_0() while
* processing <tt>__VA_ARGS__</tt> to avoid processing empty arguments.
*
* Note that this macro is intended to check macro names that evaluate
* to replacement lists being empty or containing numbers or macro name
* like tokens.
*
* @note Not all arguments are accepted by this macro and compilation will fail
* if argument cannot be concatenated with literal constant. That will
* happen if argument does not start with letter or number. Example
* arguments that will fail during compilation: .arg, (arg), "arg", {arg}.
*
* 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 @p true,
* @p false, and @p true; @p some_conditional_code is included.
*
* @param a macro to check for emptiness
*/
#define IS_EMPTY(a) Z_IS_EMPTY_(a, 1, 0,)
/**
* @brief Remove empty arguments from list.
*
* During macro expansion, <tt>__VA_ARGS__</tt> 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
*
* @param ... list to be processed
*/
#define LIST_DROP_EMPTY(...) \
Z_LIST_DROP_FIRST(FOR_EACH(Z_LIST_NO_EMPTIES, (), __VA_ARGS__))
/**
* @brief 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 EMPTY
/**
* @brief Macro that expands to its argument
*
* This is useful in macros like @c FOR_EACH() when there is no
* transformation required on the list elements.
*
* @param V any value
*/
#define IDENTITY(V) V
/**
* @brief Get nth argument from argument list.
*
* @param N Argument index to fetch. Counter from 1.
* @param ... Variable list of argments from which one argument is returned.
*
* @return Nth argument.
*/
#define GET_ARG_N(N, ...) _Z_GET_ARG_N(N, 1, __VA_ARGS__)
/**
* @brief Strips n first arguments from the argument list.
*
* @param N Number of arguments to discard.
* @param ... Variable list of argments.
*
* @return argument list without N first arguments.
*/
#define GET_ARGS_LESS_N(N, ...) _Z_GET_ARG_N(UTIL_INC(N), 0, __VA_ARGS__)
/** Expands to the first argument.
*
* @deprecated Use GET_ARG_N instead.
*/
#define GET_ARG1(...) GET_ARG_N(1, __VA_ARGS__)
/** Expands to the second argument.
*
* @deprecated Use GET_ARG_N instead.
*/
#define GET_ARG2(...) __DEPRECATED GET_ARG_N(2, __VA_ARGS__)
/** Expands to all arguments except the first one.
*
* @deprecated Use GET_ARGS_LESS_N instead.
*/
#define GET_ARGS_LESS_1(...) __DEPRECATED GET_ARGS_LESS_N(1, __VA_ARGS__)
/**
* @brief Like <tt>a || b</tt>, but does evaluation and
* short-circuiting at C preprocessor time.
*
* This is not the same as the binary @p || operator; in particular,
* @p a should expand to an integer literal 0 or 1. However, @p b
* can be any value.
*
* This can be useful when @p b is an expression that would cause a
* build error when @p a is 1.
*/
#define UTIL_OR(a, b) COND_CODE_1(UTIL_BOOL(a), (a), (b))
/**
* @brief Like <tt>a && b</tt>, but does evaluation and
* short-circuiting at C preprocessor time.
*
* This is not the same as the binary @p &&, however; in particular,
* @p a should expand to an integer literal 0 or 1. However, @p b
* can be any value.
*
* This can be useful when @p b is an expression that would cause a
* build error when @p a is 0.
*/
#define UTIL_AND(a, b) COND_CODE_1(UTIL_BOOL(a), (b), (0))
/**
* @brief Generates a sequence of code.
*
* Example:
*
* #define FOO(i, _) MY_PWM ## i ,
* { UTIL_LISTIFY(PWM_COUNT, FOO) }
*
* The above two lines expand to:
*
* { MY_PWM0 , MY_PWM1 , }
*
* @param LEN The length of the sequence. Must be an integer literal less
* than 255.
* @param F A macro function that accepts at least two arguments:
* <tt>F(i, ...)</tt>. @p F is called repeatedly in the expansion.
* Its first argument @p i is the index in the sequence, and
* the variable list of arguments passed to UTIL_LISTIFY are passed
* through to @p F.
*
* @note Calling UTIL_LISTIFY with undefined arguments has undefined
* behavior.
*/
#define UTIL_LISTIFY(LEN, F, ...) UTIL_EVAL(UTIL_REPEAT(LEN, F, __VA_ARGS__))
/**
* @brief Call a macro @p 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;
*
* @param F Macro to invoke
* @param sep Separator (e.g. comma or semicolon). Must be in parentheses;
* this is required to enable providing a comma as separator.
* @param ... Variable argument list. The macro @p F is invoked as
* <tt>F(element)</tt> for each element in the list.
*/
#define FOR_EACH(F, sep, ...) \
Z_FOR_EACH_IDX2(NUM_VA_ARGS_LESS_1(__VA_ARGS__, _), \
0, Z_FOR_EACH_SWALLOW_INDEX_FIXED_ARG, sep, \
F, 0, __VA_ARGS__)
/**
* @brief Like FOR_EACH(), but with a terminator instead of a separator,
* and drops empty elements from the argument list
*
* The @p sep argument to <tt>FOR_EACH(F, (sep), a, b)</tt> is a
* separator which is placed between calls to @p F, like this:
*
* FOR_EACH(F, (sep), a, b) // F(a) sep F(b)
* // ^^^ no sep here!
*
* By contrast, the @p term argument to <tt>FOR_EACH_NONEMPTY_TERM(F, (term),
* a, b)</tt> is added after each time @p 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 @p F that does the right thing
* even when given an empty argument.
*
* One example is when <tt>__VA_ARGS__</tt> 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:
*
* 1. figuring out whether the @p FOO, @p BAR, and @p BAZ expansions
* are empty and adding a comma manually (or not) between FOR_EACH()
* calls
* 2. rewriting SQUARE so it reacts appropriately when "x" is empty
* (which would be necessary if e.g. @p FOO expands to nothing)
*
* @param F Macro to invoke on each nonempty element of the variable
* arguments
* @param 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.
* @param ... Variable argument list. The macro @p F is invoked as
* <tt>F(element)</tt> for each nonempty element in the list.
*/
#define FOR_EACH_NONEMPTY_TERM(F, term, ...) \
COND_CODE_0( \
/* are there zero non-empty arguments ? */ \
NUM_VA_ARGS_LESS_1(LIST_DROP_EMPTY(__VA_ARGS__, _)), \
/* if so, expand to nothing */ \
(), \
/* otherwise, expand to: */ \
(/* FOR_EACH() on nonempty elements, */ \
FOR_EACH(F, term, LIST_DROP_EMPTY(__VA_ARGS__)) \
/* plus a final terminator */ \
__DEBRACKET term \
))
/**
* @brief Call macro @p F on each provided argument, with the argument's index
* as an additional parameter.
*
* This is like FOR_EACH(), except @p F should be a macro which takes two
* arguments: <tt>F(index, variable_arg)</tt>.
*
* 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;
*
* @param F Macro to invoke
* @param sep Separator (e.g. comma or semicolon). Must be in parentheses;
* this is required to enable providing a comma as separator.
* @param ... Variable argument list. The macro @p F is invoked as
* <tt>F(index, element)</tt> for each element in the list.
*/
#define FOR_EACH_IDX(F, sep, ...) \
Z_FOR_EACH_IDX2(NUM_VA_ARGS_LESS_1(__VA_ARGS__, _), \
0, Z_FOR_EACH_SWALLOW_FIXED_ARG, sep, \
F, 0, __VA_ARGS__)
/**
* @brief Call macro @p F on each provided argument, with an additional fixed
* argument as a parameter.
*
* This is like FOR_EACH(), except @p F should be a macro which takes two
* arguments: <tt>F(variable_arg, fixed_arg)</tt>.
*
* 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);
*
* @param F Macro to invoke
* @param sep Separator (e.g. comma or semicolon). Must be in parentheses;
* this is required to enable providing a comma as separator.
* @param fixed_arg Fixed argument passed to @p F as the second macro parameter.
* @param ... Variable argument list. The macro @p F is invoked as
* <tt>F(element, fixed_arg)</tt> for each element in the list.
*/
#define FOR_EACH_FIXED_ARG(F, sep, fixed_arg, ...) \
Z_FOR_EACH_IDX2(NUM_VA_ARGS_LESS_1(__VA_ARGS__, _), \
0, Z_FOR_EACH_SWALLOW_INDEX, sep, \
F, fixed_arg, __VA_ARGS__)
/**
* @brief Calls macro @p 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;
*
* @param F Macro to invoke
* @param sep Separator (e.g. comma or semicolon). Must be in parentheses;
* This is required to enable providing a comma as separator.
* @param fixed_arg Fixed argument passed to @p F as the third macro parameter.
* @param ... Variable list of arguments. The macro @p F is invoked as
* <tt>F(index, element, fixed_arg)</tt> for each element in
* the list.
*/
#define FOR_EACH_IDX_FIXED_ARG(F, sep, fixed_arg, ...) \
Z_FOR_EACH_IDX2(NUM_VA_ARGS_LESS_1(__VA_ARGS__, _), \
0, Z_FOR_EACH_SWALLOW_NOTHING, sep, \
F, fixed_arg, __VA_ARGS__)
/**
* @brief Number of arguments in the variable arguments list minus one.
*
* @param ... List of arguments
* @return Number of variadic arguments in the argument list, minus one
*/
#define NUM_VA_ARGS_LESS_1(...) \
NUM_VA_ARGS_LESS_1_IMPL(__VA_ARGS__, 63, 62, 61, \
60, 59, 58, 57, 56, 55, 54, 53, 52, 51, \
50, 49, 48, 47, 46, 45, 44, 43, 42, 41, \
40, 39, 38, 37, 36, 35, 34, 33, 32, 31, \
30, 29, 28, 27, 26, 25, 24, 23, 22, 21, \
20, 19, 18, 17, 16, 15, 14, 13, 12, 11, \
10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, ~)
/**
* @brief Mapping macro that pastes results together
*
* This is similar to FOR_EACH() in that it invokes a macro repeatedly
* on each element of <tt>__VA_ARGS__</tt>. 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##_
*
* <tt>MACRO_MAP_CAT(FOO, a, b, c),</tt> expands to the token:
*
* item_a_item_b_item_c_
*
* @param ... Macro to expand on each argument, followed by its
* arguments. (The macro should take exactly one argument.)
* @return The results of expanding the macro on each argument, all pasted
* together
*/
#define MACRO_MAP_CAT(...) MACRO_MAP_CAT_(__VA_ARGS__)
/**
* @brief Mapping macro that pastes a fixed number of results together
*
* Similar to @ref MACRO_MAP_CAT(), but expects a fixed number of
* arguments. If more arguments are given than are expected, the rest
* are ignored.
*
* @param N Number of arguments to map
* @param ... Macro to expand on each argument, followed by its
* arguments. (The macro should take exactly one argument.)
* @return The results of expanding the macro on each argument, all pasted
* together
*/
#define MACRO_MAP_CAT_N(N, ...) MACRO_MAP_CAT_N_(N, __VA_ARGS__)
/** /**
* @} * @}
*/ */
#ifdef __cplusplus
}
#endif
#endif /* ZEPHYR_INCLUDE_SYS_UTIL_H_ */ #endif /* ZEPHYR_INCLUDE_SYS_UTIL_H_ */

584
include/sys/util_macro.h Normal file
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@ -0,0 +1,584 @@
/*
* Copyright (c) 2011-2014, Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Macro utilities
*
* Macro utilities are the public interface for C/C++ code and device tree
* related implementation. In general, C/C++ will include <sys/util.h>
* instead this file directly. For device tree implementation, this file
* should be include instead <sys/util_internal.h>
*/
#ifndef ZEPHYR_INCLUDE_SYS_UTIL_MACROS_H_
#define ZEPHYR_INCLUDE_SYS_UTIL_MACROS_H_
#ifdef __cplusplus
extern "C" {
#endif
/*
* Most of the eldritch implementation details for all the macrobatics
* below (APIs like IS_ENABLED(), COND_CODE_1(), etc.) are hidden away
* in this file.
*/
#include <sys/util_internal.h>
/**
* @brief 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 @p CONFIG_FOO macro which
* may be defined to 1 via Kconfig, or left undefined.
*
* That is, it works similarly to <tt>\#if defined(CONFIG_FOO)</tt>
* except that its expansion is a C expression. Thus, much <tt>\#ifdef</tt>
* 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 @p do_something_with_foo even when @p CONFIG_FOO is undefined.
*
* @param config_macro Macro to check
* @return 1 if @p config_macro is defined to 1, 0 otherwise (including
* if @p config_macro is not defined)
*/
#define IS_ENABLED(config_macro) Z_IS_ENABLED1(config_macro)
/* INTERNAL: the first pass above is 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.
*/
/**
* @brief Insert code depending on whether @p _flag expands to 1 or not.
*
* This relies on similar tricks as IS_ENABLED(), but as the result of
* @p _flag expansion, results in either @p _if_1_code or @p
* _else_code is expanded.
*
* To prevent the preprocessor from treating commas as argument
* separators, the @p _if_1_code and @p _else_code expressions must be
* inside brackets/parentheses: <tt>()</tt>. These are stripped away
* during macro expansion.
*
* Example:
*
* COND_CODE_1(CONFIG_FLAG, (uint32_t x;), (there_is_no_flag();))
*
* If @p CONFIG_FLAG is defined to 1, this expands to:
*
* uint32_t x;
*
* It expands to <tt>there_is_no_flag();</tt> 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 @p \#if method defines @p
* 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.
*
* @note @p _flag can be the result of preprocessor expansion, e.g.
* an expression involving <tt>NUM_VA_ARGS_LESS_1(...)</tt>.
* However, @p _if_1_code is only expanded if @p _flag expands
* to the integer literal 1. Integer expressions that evaluate
* to 1, e.g. after doing some arithmetic, will not work.
*
* @param _flag evaluated flag
* @param _if_1_code result if @p _flag expands to 1; must be in parentheses
* @param _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)
/**
* @brief Like COND_CODE_1() except tests if @p _flag is 0.
*
* This is like COND_CODE_1(), except that it tests whether @p _flag
* expands to the integer literal 0. It expands to @p _if_0_code if
* so, and @p _else_code otherwise; both of these must be enclosed in
* parentheses.
*
* @param _flag evaluated flag
* @param _if_0_code result if @p _flag expands to 0; must be in parentheses
* @param _else_code result otherwise; must be in parentheses
* @see COND_CODE_1()
*/
#define COND_CODE_0(_flag, _if_0_code, _else_code) \
Z_COND_CODE_0(_flag, _if_0_code, _else_code)
/**
* @brief Insert code if @p _flag is defined and equals 1.
*
* Like COND_CODE_1(), this expands to @p _code if @p _flag is defined to 1;
* it expands to nothing otherwise.
*
* Example:
*
* IF_ENABLED(CONFIG_FLAG, (uint32_t foo;))
*
* If @p 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
*
* @param _flag evaluated flag
* @param _code result if @p _flag expands to 1; must be in parentheses
*/
#define IF_ENABLED(_flag, _code) \
COND_CODE_1(_flag, _code, ())
/**
* @brief Check if a macro has a replacement expression
*
* If @p 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 @p \#ifdef test may be needed in some cases.
*
* This macro may be used with COND_CODE_1() and COND_CODE_0() while
* processing <tt>__VA_ARGS__</tt> to avoid processing empty arguments.
*
* Note that this macro is intended to check macro names that evaluate
* to replacement lists being empty or containing numbers or macro name
* like tokens.
*
* @note Not all arguments are accepted by this macro and compilation will fail
* if argument cannot be concatenated with literal constant. That will
* happen if argument does not start with letter or number. Example
* arguments that will fail during compilation: .arg, (arg), "arg", {arg}.
*
* 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 @p true,
* @p false, and @p true; @p some_conditional_code is included.
*
* @param a macro to check for emptiness
*/
#define IS_EMPTY(a) Z_IS_EMPTY_(a, 1, 0,)
/**
* @brief Remove empty arguments from list.
*
* During macro expansion, <tt>__VA_ARGS__</tt> 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
*
* @param ... list to be processed
*/
#define LIST_DROP_EMPTY(...) \
Z_LIST_DROP_FIRST(FOR_EACH(Z_LIST_NO_EMPTIES, (), __VA_ARGS__))
/**
* @brief 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 EMPTY
/**
* @brief Macro that expands to its argument
*
* This is useful in macros like @c FOR_EACH() when there is no
* transformation required on the list elements.
*
* @param V any value
*/
#define IDENTITY(V) V
/**
* @brief Get nth argument from argument list.
*
* @param N Argument index to fetch. Counter from 1.
* @param ... Variable list of argments from which one argument is returned.
*
* @return Nth argument.
*/
#define GET_ARG_N(N, ...) _Z_GET_ARG_N(N, 1, __VA_ARGS__)
/**
* @brief Strips n first arguments from the argument list.
*
* @param N Number of arguments to discard.
* @param ... Variable list of argments.
*
* @return argument list without N first arguments.
*/
#define GET_ARGS_LESS_N(N, ...) _Z_GET_ARG_N(UTIL_INC(N), 0, __VA_ARGS__)
/** Expands to the first argument.
*
* @deprecated Use GET_ARG_N instead.
*/
#define GET_ARG1(...) GET_ARG_N(1, __VA_ARGS__)
/** Expands to the second argument.
*
* @deprecated Use GET_ARG_N instead.
*/
#define GET_ARG2(...) __DEPRECATED GET_ARG_N(2, __VA_ARGS__)
/** Expands to all arguments except the first one.
*
* @deprecated Use GET_ARGS_LESS_N instead.
*/
#define GET_ARGS_LESS_1(...) __DEPRECATED GET_ARGS_LESS_N(1, __VA_ARGS__)
/**
* @brief Like <tt>a || b</tt>, but does evaluation and
* short-circuiting at C preprocessor time.
*
* This is not the same as the binary @p || operator; in particular,
* @p a should expand to an integer literal 0 or 1. However, @p b
* can be any value.
*
* This can be useful when @p b is an expression that would cause a
* build error when @p a is 1.
*/
#define UTIL_OR(a, b) COND_CODE_1(UTIL_BOOL(a), (a), (b))
/**
* @brief Like <tt>a && b</tt>, but does evaluation and
* short-circuiting at C preprocessor time.
*
* This is not the same as the binary @p &&, however; in particular,
* @p a should expand to an integer literal 0 or 1. However, @p b
* can be any value.
*
* This can be useful when @p b is an expression that would cause a
* build error when @p a is 0.
*/
#define UTIL_AND(a, b) COND_CODE_1(UTIL_BOOL(a), (b), (0))
/**
* @brief Generates a sequence of code.
*
* Example:
*
* #define FOO(i, _) MY_PWM ## i ,
* { UTIL_LISTIFY(PWM_COUNT, FOO) }
*
* The above two lines expand to:
*
* { MY_PWM0 , MY_PWM1 , }
*
* @param LEN The length of the sequence. Must be an integer literal less
* than 255.
* @param F A macro function that accepts at least two arguments:
* <tt>F(i, ...)</tt>. @p F is called repeatedly in the expansion.
* Its first argument @p i is the index in the sequence, and
* the variable list of arguments passed to UTIL_LISTIFY are passed
* through to @p F.
*
* @note Calling UTIL_LISTIFY with undefined arguments has undefined
* behavior.
*/
#define UTIL_LISTIFY(LEN, F, ...) UTIL_EVAL(UTIL_REPEAT(LEN, F, __VA_ARGS__))
/**
* @brief Call a macro @p 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;
*
* @param F Macro to invoke
* @param sep Separator (e.g. comma or semicolon). Must be in parentheses;
* this is required to enable providing a comma as separator.
* @param ... Variable argument list. The macro @p F is invoked as
* <tt>F(element)</tt> for each element in the list.
*/
#define FOR_EACH(F, sep, ...) \
Z_FOR_EACH_IDX2(NUM_VA_ARGS_LESS_1(__VA_ARGS__, _), \
0, Z_FOR_EACH_SWALLOW_INDEX_FIXED_ARG, sep, \
F, 0, __VA_ARGS__)
/**
* @brief Like FOR_EACH(), but with a terminator instead of a separator,
* and drops empty elements from the argument list
*
* The @p sep argument to <tt>FOR_EACH(F, (sep), a, b)</tt> is a
* separator which is placed between calls to @p F, like this:
*
* FOR_EACH(F, (sep), a, b) // F(a) sep F(b)
* // ^^^ no sep here!
*
* By contrast, the @p term argument to <tt>FOR_EACH_NONEMPTY_TERM(F, (term),
* a, b)</tt> is added after each time @p 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 @p F that does the right thing
* even when given an empty argument.
*
* One example is when <tt>__VA_ARGS__</tt> 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:
*
* 1. figuring out whether the @p FOO, @p BAR, and @p BAZ expansions
* are empty and adding a comma manually (or not) between FOR_EACH()
* calls
* 2. rewriting SQUARE so it reacts appropriately when "x" is empty
* (which would be necessary if e.g. @p FOO expands to nothing)
*
* @param F Macro to invoke on each nonempty element of the variable
* arguments
* @param 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.
* @param ... Variable argument list. The macro @p F is invoked as
* <tt>F(element)</tt> for each nonempty element in the list.
*/
#define FOR_EACH_NONEMPTY_TERM(F, term, ...) \
COND_CODE_0( \
/* are there zero non-empty arguments ? */ \
NUM_VA_ARGS_LESS_1(LIST_DROP_EMPTY(__VA_ARGS__, _)), \
/* if so, expand to nothing */ \
(), \
/* otherwise, expand to: */ \
(/* FOR_EACH() on nonempty elements, */ \
FOR_EACH(F, term, LIST_DROP_EMPTY(__VA_ARGS__)) \
/* plus a final terminator */ \
__DEBRACKET term \
))
/**
* @brief Call macro @p F on each provided argument, with the argument's index
* as an additional parameter.
*
* This is like FOR_EACH(), except @p F should be a macro which takes two
* arguments: <tt>F(index, variable_arg)</tt>.
*
* 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;
*
* @param F Macro to invoke
* @param sep Separator (e.g. comma or semicolon). Must be in parentheses;
* this is required to enable providing a comma as separator.
* @param ... Variable argument list. The macro @p F is invoked as
* <tt>F(index, element)</tt> for each element in the list.
*/
#define FOR_EACH_IDX(F, sep, ...) \
Z_FOR_EACH_IDX2(NUM_VA_ARGS_LESS_1(__VA_ARGS__, _), \
0, Z_FOR_EACH_SWALLOW_FIXED_ARG, sep, \
F, 0, __VA_ARGS__)
/**
* @brief Call macro @p F on each provided argument, with an additional fixed
* argument as a parameter.
*
* This is like FOR_EACH(), except @p F should be a macro which takes two
* arguments: <tt>F(variable_arg, fixed_arg)</tt>.
*
* 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);
*
* @param F Macro to invoke
* @param sep Separator (e.g. comma or semicolon). Must be in parentheses;
* this is required to enable providing a comma as separator.
* @param fixed_arg Fixed argument passed to @p F as the second macro parameter.
* @param ... Variable argument list. The macro @p F is invoked as
* <tt>F(element, fixed_arg)</tt> for each element in the list.
*/
#define FOR_EACH_FIXED_ARG(F, sep, fixed_arg, ...) \
Z_FOR_EACH_IDX2(NUM_VA_ARGS_LESS_1(__VA_ARGS__, _), \
0, Z_FOR_EACH_SWALLOW_INDEX, sep, \
F, fixed_arg, __VA_ARGS__)
/**
* @brief Calls macro @p 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;
*
* @param F Macro to invoke
* @param sep Separator (e.g. comma or semicolon). Must be in parentheses;
* This is required to enable providing a comma as separator.
* @param fixed_arg Fixed argument passed to @p F as the third macro parameter.
* @param ... Variable list of arguments. The macro @p F is invoked as
* <tt>F(index, element, fixed_arg)</tt> for each element in
* the list.
*/
#define FOR_EACH_IDX_FIXED_ARG(F, sep, fixed_arg, ...) \
Z_FOR_EACH_IDX2(NUM_VA_ARGS_LESS_1(__VA_ARGS__, _), \
0, Z_FOR_EACH_SWALLOW_NOTHING, sep, \
F, fixed_arg, __VA_ARGS__)
/**
* @brief Number of arguments in the variable arguments list minus one.
*
* @param ... List of arguments
* @return Number of variadic arguments in the argument list, minus one
*/
#define NUM_VA_ARGS_LESS_1(...) \
NUM_VA_ARGS_LESS_1_IMPL(__VA_ARGS__, 63, 62, 61, \
60, 59, 58, 57, 56, 55, 54, 53, 52, 51, \
50, 49, 48, 47, 46, 45, 44, 43, 42, 41, \
40, 39, 38, 37, 36, 35, 34, 33, 32, 31, \
30, 29, 28, 27, 26, 25, 24, 23, 22, 21, \
20, 19, 18, 17, 16, 15, 14, 13, 12, 11, \
10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, ~)
/**
* @brief Mapping macro that pastes results together
*
* This is similar to FOR_EACH() in that it invokes a macro repeatedly
* on each element of <tt>__VA_ARGS__</tt>. 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##_
*
* <tt>MACRO_MAP_CAT(FOO, a, b, c),</tt> expands to the token:
*
* item_a_item_b_item_c_
*
* @param ... Macro to expand on each argument, followed by its
* arguments. (The macro should take exactly one argument.)
* @return The results of expanding the macro on each argument, all pasted
* together
*/
#define MACRO_MAP_CAT(...) MACRO_MAP_CAT_(__VA_ARGS__)
/**
* @brief Mapping macro that pastes a fixed number of results together
*
* Similar to @ref MACRO_MAP_CAT(), but expects a fixed number of
* arguments. If more arguments are given than are expected, the rest
* are ignored.
*
* @param N Number of arguments to map
* @param ... Macro to expand on each argument, followed by its
* arguments. (The macro should take exactly one argument.)
* @return The results of expanding the macro on each argument, all pasted
* together
*/
#define MACRO_MAP_CAT_N(N, ...) MACRO_MAP_CAT_N_(N, __VA_ARGS__)
/**
* @}
*/
#ifdef __cplusplus
}
#endif
#endif /* ZEPHYR_INCLUDE_SYS_UTIL_MACROS_H_ */