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zephyr/include/misc/util.h
Shawn Mosley 573f32b6d2 userspace: compartmentalized app memory organization 
Summary: revised attempt at addressing issue 6290.  The
following provides an alternative to using
CONFIG_APPLICATION_MEMORY by compartmentalizing data into
Memory Domains.  Dependent on MPU limitations, supports
compartmentalized Memory Domains for 1...N logical
applications.  This is considered an initial attempt at
designing flexible compartmentalized Memory Domains for
multiple logical applications and, with the provided python
script and edited CMakeLists.txt, provides support for power
of 2 aligned MPU architectures.

Overview: The current patch uses qualifiers to group data into
subsections.  The qualifier usage allows for dynamic subsection
creation and affords the developer a large amount of flexibility
in the grouping, naming, and size of the resulting partitions and
domains that are built on these subsections. By additional macro
calls, functions are created that help calculate the size,
address, and permissions for the subsections and enable the
developer to control application data in specified partitions and
memory domains.

Background: Initial attempts focused on creating a single
section in the linker script that then contained internally
grouped variables/data to allow MPU/MMU alignment and protection.
This did not provide additional functionality beyond
CONFIG_APPLICATION_MEMORY as we were unable to reliably group
data or determine their grouping via exported linker symbols.
Thus, the resulting decision was made to dynamically create
subsections using the current qualifier method. An attempt to
group the data by object file was tested, but found that this
broke applications such as ztest where two object files are
created: ztest and main.  This also creates an issue of grouping
the two object files together in the same memory domain while
also allowing for compartmenting other data among threads.

Because it is not possible to know a) the name of the partition
and thus the symbol in the linker, b) the size of all the data
in the subsection, nor c) the overall number of partitions
created by the developer, it was not feasible to align the
subsections at compile time without using dynamically generated
linker script for MPU architectures requiring power of 2
alignment.

In order to provide support for MPU architectures that require a
power of 2 alignment, a python script is run at build prior to
when linker_priv_stacks.cmd is generated.  This script scans the
built object files for all possible partitions and the names given
to them. It then generates a linker file (app_smem.ld) that is
included in the main linker.ld file.  This app_smem.ld allows the
compiler and linker to then create each subsection and align to
the next power of 2.

Usage:
 - Requires: app_memory/app_memdomain.h .
 - _app_dmem(id) marks a variable to be placed into a data
section for memory partition id.
 - _app_bmem(id) marks a variable to be placed into a bss
section for memory partition id.
 - These are seen in the linker.map as "data_smem_id" and
"data_smem_idb".
 - To create a k_mem_partition, call the macro
app_mem_partition(part0) where "part0" is the name then used to
refer to that partition. This macro only creates a function and
necessary data structures for the later "initialization".
 - To create a memory domain for the partition, the macro
app_mem_domain(dom0) is called where "dom0" is the name then
used for the memory domain.
 - To initialize the partition (effectively adding the partition
to a linked list), init_part_part0() is called. This is followed
by init_app_memory(), which walks all partitions in the linked
list and calculates the sizes for each partition.
 - Once the partition is initialized, the domain can be
initialized with init_domain_dom0(part0) which initializes the
domain with partition part0.
 - After the domain has been initialized, the current thread
can be added using add_thread_dom0(k_current_get()).
 - The code used in ztests ans kernel/init has been added under
a conditional #ifdef to isolate the code from other tests.
The userspace test CMakeLists.txt file has commands to insert
the CONFIG_APP_SHARED_MEM definition into the required build
targets.
  Example:
        /* create partition at top of file outside functions */
        app_mem_partition(part0);
        /* create domain */
        app_mem_domain(dom0);
        _app_dmem(dom0) int var1;
        _app_bmem(dom0) static volatile int var2;

        int main()
        {
                init_part_part0();
                init_app_memory();
                init_domain_dom0(part0);
                add_thread_dom0(k_current_get());
                ...
        }

 - If multiple partitions are being created, a variadic
preprocessor macro can be used as provided in
app_macro_support.h:

        FOR_EACH(app_mem_partition, part0, part1, part2);

or, for multiple domains, similarly:

        FOR_EACH(app_mem_domain, dom0, dom1);

Similarly, the init_part_* can also be used in the macro:

        FOR_EACH(init_part, part0, part1, part2);

Testing:
 - This has been successfully tested on qemu_x86 and the
ARM frdm_k64f board.  It compiles and builds power of 2
aligned subsections for the linker script on the 96b_carbon
boards.  These power of 2 alignments have been checked by
hand and are viewable in the zephyr.map file that is
produced during build. However, due to a shortage of
available MPU regions on the 96b_carbon board, we are unable
to test this.
 - When run on the 96b_carbon board, the test suite will
enter execution, but each individaul test will fail due to
an MPU FAULT.  This is expected as the required number of
MPU regions exceeds the number allowed due to the static
allocation. As the MPU driver does not detect this issue,
the fault occurs because the data being accessed has been
placed outside the active MPU region.
 - This now compiles successfully for the ARC boards
em_starterkit_em7d and em_starterkit_em7d_v22. However,
as we lack ARC hardware to run this build on, we are unable
to test this build.

Current known issues:
1) While the script and edited CMakeLists.txt creates the
ability to align to the next power of 2, this does not
address the shortage of available MPU regions on certain
devices (e.g. 96b_carbon).  In testing the APB and PPB
regions were commented out.
2) checkpatch.pl lists several issues regarding the
following:
a) Complex macros. The FOR_EACH macros as defined in
app_macro_support.h are listed as complex macros needing
parentheses.  Adding parentheses breaks their
functionality, and we have otherwise been unable to
resolve the reported error.
b) __aligned() preferred. The _app_dmem_pad() and
_app_bmem_pad() macros give warnings that __aligned()
is preferred. Prior iterations had this implementation,
which resulted in errors due to "complex macros".
c) Trailing semicolon. The macro init_part(name) has
a trailing semicolon as the semicolon is needed for the
inlined macro call that is generated when this macro
expands.

Update: updated to alternative CONFIG_APPLCATION_MEMORY.
Added config option CONFIG_APP_SHARED_MEM to enable a new section
app_smem to contain the shared memory component.  This commit
seperates the Kconfig definition from the definition used for the
conditional code.  The change is in response to changes in the
way the build system treats definitions.  The python script used
to generate a linker script for app_smem was also midified to
simplify the alignment directives.  A default linker script
app_smem.ld was added to remove the conditional includes dependency
on CONFIG_APP_SHARED_MEM.  By addining the default linker script
the prebuild stages link properly prior to the python script running

Signed-off-by: Joshua Domagalski <jedomag@tycho.nsa.gov>
Signed-off-by: Shawn Mosley <smmosle@tycho.nsa.gov>
2018-07-25 12:02:01 -07:00

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/*
* 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_
#ifndef _ASMLANGUAGE
#include <zephyr/types.h>
/* 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])))
#if defined(__cplusplus)
template < class T, size_t N >
constexpr size_t ARRAY_SIZE(T(&)[N]) { return N; }
#else
/* 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]))))
#endif
/* 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_DEC_20 19
#define UTIL_DEC_21 20
#define UTIL_DEC_22 21
#define UTIL_DEC_23 22
#define UTIL_DEC_24 23
#define UTIL_DEC_25 24
#define UTIL_DEC_26 25
#define UTIL_DEC_27 26
#define UTIL_DEC_28 27
#define UTIL_DEC_29 28
#define UTIL_DEC_30 29
#define UTIL_DEC_31 30
#define UTIL_DEC_32 31
#define UTIL_DEC_33 32
#define UTIL_DEC_34 33
#define UTIL_DEC_35 34
#define UTIL_DEC_36 35
#define UTIL_DEC_37 36
#define UTIL_DEC_38 37
#define UTIL_DEC_39 38
#define UTIL_DEC_40 39
#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
* behavior.
*/
#define UTIL_LISTIFY(LEN, F, F_ARG) UTIL_EVAL(UTIL_REPEAT(LEN, F, F_ARG))
/**@brief Implementation details for NUM_VAR_ARGS */
#define NUM_VA_ARGS_LESS_1_IMPL( \
_ignored, \
_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, \
_11, _12, _13, _14, _15, _16, _17, _18, _19, _20, \
_21, _22, _23, _24, _25, _26, _27, _28, _29, _30, \
_31, _32, _33, _34, _35, _36, _37, _38, _39, _40, \
_41, _42, _43, _44, _45, _46, _47, _48, _49, _50, \
_51, _52, _53, _54, _55, _56, _57, _58, _59, _60, \
_61, _62, N, ...) N
/**@brief Macro to get the number of arguments in a call variadic macro call.
* First argument is not counted.
*
* param[in] ... List of arguments
*
* @retval Number of variadic arguments in the argument list
*/
#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
*
* Macro that process all arguments using given macro
*
* @param ... Macro name to be used for argument processing followed by
* arguments to process. Macro should have following
* form: MACRO(argument).
*
* @return All arguments processed by given macro
*/
#define MACRO_MAP(...) MACRO_MAP_(__VA_ARGS__)
#define MACRO_MAP_(...) \
/* To make sure it works also for 2 arguments in total */ \
MACRO_MAP_N(NUM_VA_ARGS_LESS_1(__VA_ARGS__), __VA_ARGS__)
/**
* @brief Mapping N arguments macro
*
* Macro similar to @ref MACRO_MAP but maps exact number of arguments.
* If there is more arguments given, the rest would be ignored.
*
* @param N Number of arguments to map
* @param ... Macro name to be used for argument processing followed by
* arguments to process. Macro should have following
* form: MACRO(argument).
*
* @return Selected number of arguments processed by given macro
*/
#define MACRO_MAP_N(N, ...) MACRO_MAP_N_(N, __VA_ARGS__)
#define MACRO_MAP_N_(N, ...) UTIL_CAT(MACRO_MAP_, N)(__VA_ARGS__,)
#define MACRO_MAP_0(...)
#define MACRO_MAP_1(macro, a, ...) macro(a)
#define MACRO_MAP_2(macro, a, ...) macro(a)MACRO_MAP_1(macro, __VA_ARGS__,)
#define MACRO_MAP_3(macro, a, ...) macro(a)MACRO_MAP_2(macro, __VA_ARGS__,)
#define MACRO_MAP_4(macro, a, ...) macro(a)MACRO_MAP_3(macro, __VA_ARGS__,)
#define MACRO_MAP_5(macro, a, ...) macro(a)MACRO_MAP_4(macro, __VA_ARGS__,)
#define MACRO_MAP_6(macro, a, ...) macro(a)MACRO_MAP_5(macro, __VA_ARGS__,)
#define MACRO_MAP_7(macro, a, ...) macro(a)MACRO_MAP_6(macro, __VA_ARGS__,)
#define MACRO_MAP_8(macro, a, ...) macro(a)MACRO_MAP_7(macro, __VA_ARGS__,)
#define MACRO_MAP_9(macro, a, ...) macro(a)MACRO_MAP_8(macro, __VA_ARGS__,)
#define MACRO_MAP_10(macro, a, ...) macro(a)MACRO_MAP_9(macro, __VA_ARGS__,)
#define MACRO_MAP_11(macro, a, ...) macro(a)MACRO_MAP_10(macro, __VA_ARGS__,)
#define MACRO_MAP_12(macro, a, ...) macro(a)MACRO_MAP_11(macro, __VA_ARGS__,)
#define MACRO_MAP_13(macro, a, ...) macro(a)MACRO_MAP_12(macro, __VA_ARGS__,)
#define MACRO_MAP_14(macro, a, ...) macro(a)MACRO_MAP_13(macro, __VA_ARGS__,)
#define MACRO_MAP_15(macro, a, ...) macro(a)MACRO_MAP_14(macro, __VA_ARGS__,)
/*
* The following provides variadic preprocessor macro support to
* help eliminate multiple, repetitive function/macro calls. This
* allows up to 10 "arguments" in addition to _call .
* Note - derived from work on:
* https://codecraft.co/2014/11/25/variadic-macros-tricks/
*/
#define _GET_ARG(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, N, ...) N
#define _for_0(_call, ...)
#define _for_1(_call, x) _call(x)
#define _for_2(_call, x, ...) _call(x) _for_1(_call, ##__VA_ARGS__)
#define _for_3(_call, x, ...) _call(x) _for_2(_call, ##__VA_ARGS__)
#define _for_4(_call, x, ...) _call(x) _for_3(_call, ##__VA_ARGS__)
#define _for_5(_call, x, ...) _call(x) _for_4(_call, ##__VA_ARGS__)
#define _for_6(_call, x, ...) _call(x) _for_5(_call, ##__VA_ARGS__)
#define _for_7(_call, x, ...) _call(x) _for_6(_call, ##__VA_ARGS__)
#define _for_8(_call, x, ...) _call(x) _for_7(_call, ##__VA_ARGS__)
#define _for_9(_call, x, ...) _call(x) _for_8(_call, ##__VA_ARGS__)
#define _for_10(_call, x, ...) _call(x) _for_9(_call, ##__VA_ARGS__)
#define FOR_EACH(x, ...) \
_GET_ARG(__VA_ARGS__, \
_for_10, _for_9, _for_8, _for_7, _for_6, _for_5, \
_for_4, _for_3, _for_2, _for_1, _for_0)(x, ##__VA_ARGS__)
#endif /* _UTIL__H_ */
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