build: update compiler*.h to newest versions
This adds the support for gcc 5.x and clang. Signed-off-by: Alexey Galakhov <agalakhov@gmail.com> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Alexey Galakhov
Holger Hans Peter Freyther
parent
79f12bc8b4
commit
d87c27d7ab
|
|
@ -0,0 +1,12 @@
|
|||
#ifndef __LINUX_COMPILER_H
|
||||
#error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."
|
||||
#endif
|
||||
|
||||
/* Some compiler specific definitions are overwritten here
|
||||
* for Clang compiler
|
||||
*/
|
||||
|
||||
#ifdef uninitialized_var
|
||||
#undef uninitialized_var
|
||||
#define uninitialized_var(x) x = *(&(x))
|
||||
#endif
|
||||
|
|
@ -5,11 +5,28 @@
|
|||
/*
|
||||
* Common definitions for all gcc versions go here.
|
||||
*/
|
||||
|
||||
#define GCC_VERSION (__GNUC__ * 10000 \
|
||||
+ __GNUC_MINOR__ * 100 \
|
||||
+ __GNUC_PATCHLEVEL__)
|
||||
|
||||
/* Optimization barrier */
|
||||
|
||||
/* The "volatile" is due to gcc bugs */
|
||||
#define barrier() __asm__ __volatile__("": : :"memory")
|
||||
/*
|
||||
* This version is i.e. to prevent dead stores elimination on @ptr
|
||||
* where gcc and llvm may behave differently when otherwise using
|
||||
* normal barrier(): while gcc behavior gets along with a normal
|
||||
* barrier(), llvm needs an explicit input variable to be assumed
|
||||
* clobbered. The issue is as follows: while the inline asm might
|
||||
* access any memory it wants, the compiler could have fit all of
|
||||
* @ptr into memory registers instead, and since @ptr never escaped
|
||||
* from that, it proofed that the inline asm wasn't touching any of
|
||||
* it. This version works well with both compilers, i.e. we're telling
|
||||
* the compiler that the inline asm absolutely may see the contents
|
||||
* of @ptr. See also: https://llvm.org/bugs/show_bug.cgi?id=15495
|
||||
*/
|
||||
#define barrier_data(ptr) __asm__ __volatile__("": :"r"(ptr) :"memory")
|
||||
|
||||
/*
|
||||
* This macro obfuscates arithmetic on a variable address so that gcc
|
||||
|
|
@ -29,39 +46,63 @@
|
|||
* the inline assembly constraint from =g to =r, in this particular
|
||||
* case either is valid.
|
||||
*/
|
||||
#define RELOC_HIDE(ptr, off) \
|
||||
({ unsigned long __ptr; \
|
||||
__asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
|
||||
(typeof(ptr)) (__ptr + (off)); })
|
||||
#define RELOC_HIDE(ptr, off) \
|
||||
({ \
|
||||
unsigned long __ptr; \
|
||||
__asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
|
||||
(typeof(ptr)) (__ptr + (off)); \
|
||||
})
|
||||
|
||||
/* Make the optimizer believe the variable can be manipulated arbitrarily. */
|
||||
#define OPTIMIZER_HIDE_VAR(var) \
|
||||
__asm__ ("" : "=r" (var) : "0" (var))
|
||||
|
||||
#ifdef __CHECKER__
|
||||
#define __must_be_array(a) 0
|
||||
#else
|
||||
/* &a[0] degrades to a pointer: a different type from an array */
|
||||
#define __must_be_array(a) \
|
||||
BUILD_BUG_ON_ZERO(__builtin_types_compatible_p(typeof(a), typeof(&a[0])))
|
||||
#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Force always-inline if the user requests it so via the .config,
|
||||
* or if gcc is too old:
|
||||
*/
|
||||
#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
|
||||
#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
|
||||
!defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
|
||||
# define inline inline __attribute__((always_inline))
|
||||
# define __inline__ __inline__ __attribute__((always_inline))
|
||||
# define __inline __inline __attribute__((always_inline))
|
||||
#define inline inline __attribute__((always_inline)) notrace
|
||||
#define __inline__ __inline__ __attribute__((always_inline)) notrace
|
||||
#define __inline __inline __attribute__((always_inline)) notrace
|
||||
#else
|
||||
/* A lot of inline functions can cause havoc with function tracing */
|
||||
#define inline inline notrace
|
||||
#define __inline__ __inline__ notrace
|
||||
#define __inline __inline notrace
|
||||
#endif
|
||||
|
||||
#define __deprecated __attribute__((deprecated))
|
||||
#define __packed __attribute__((packed))
|
||||
#define __weak __attribute__((weak))
|
||||
#define __always_inline inline __attribute__((always_inline))
|
||||
#define noinline __attribute__((noinline))
|
||||
|
||||
#define __deprecated __attribute__((deprecated))
|
||||
#define __packed __attribute__((packed))
|
||||
#define __weak __attribute__((weak))
|
||||
#define __alias(symbol) __attribute__((alias(#symbol)))
|
||||
|
||||
/*
|
||||
* it doesn't make sense on ARM (currently the only user of __naked) to trace
|
||||
* naked functions because then mcount is called without stack and frame pointer
|
||||
* being set up and there is no chance to restore the lr register to the value
|
||||
* before mcount was called.
|
||||
* it doesn't make sense on ARM (currently the only user of __naked)
|
||||
* to trace naked functions because then mcount is called without
|
||||
* stack and frame pointer being set up and there is no chance to
|
||||
* restore the lr register to the value before mcount was called.
|
||||
*
|
||||
* The asm() bodies of naked functions often depend on standard calling
|
||||
* conventions, therefore they must be noinline and noclone.
|
||||
*
|
||||
* GCC 4.[56] currently fail to enforce this, so we must do so ourselves.
|
||||
* See GCC PR44290.
|
||||
*/
|
||||
#define __naked __attribute__((naked)) notrace
|
||||
#define __naked __attribute__((naked)) noinline __noclone notrace
|
||||
|
||||
#define __noreturn __attribute__((noreturn))
|
||||
#define __noreturn __attribute__((noreturn))
|
||||
|
||||
/*
|
||||
* From the GCC manual:
|
||||
|
|
@ -73,15 +114,137 @@
|
|||
* would be.
|
||||
* [...]
|
||||
*/
|
||||
#define __pure __attribute__((pure))
|
||||
#define __aligned(x) __attribute__((aligned(x)))
|
||||
#define __printf(a,b) __attribute__((format(printf,a,b)))
|
||||
#define noinline __attribute__((noinline))
|
||||
#define __attribute_const__ __attribute__((__const__))
|
||||
#define __maybe_unused __attribute__((unused))
|
||||
#define __always_unused __attribute__((unused))
|
||||
#define __pure __attribute__((pure))
|
||||
#define __aligned(x) __attribute__((aligned(x)))
|
||||
#define __printf(a, b) __attribute__((format(printf, a, b)))
|
||||
#define __scanf(a, b) __attribute__((format(scanf, a, b)))
|
||||
#define __attribute_const__ __attribute__((__const__))
|
||||
#define __maybe_unused __attribute__((unused))
|
||||
#define __always_unused __attribute__((unused))
|
||||
|
||||
#define __gcc_header(x) #x
|
||||
#define _gcc_header(x) __gcc_header(linux/compiler-gcc##x.h)
|
||||
#define gcc_header(x) _gcc_header(x)
|
||||
#include gcc_header(__GNUC__)
|
||||
/* gcc version specific checks */
|
||||
|
||||
#if GCC_VERSION < 30200
|
||||
# error Sorry, your compiler is too old - please upgrade it.
|
||||
#endif
|
||||
|
||||
#if GCC_VERSION < 30300
|
||||
# define __used __attribute__((__unused__))
|
||||
#else
|
||||
# define __used __attribute__((__used__))
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_GCOV_KERNEL
|
||||
# if GCC_VERSION < 30400
|
||||
# error "GCOV profiling support for gcc versions below 3.4 not included"
|
||||
# endif /* __GNUC_MINOR__ */
|
||||
#endif /* CONFIG_GCOV_KERNEL */
|
||||
|
||||
#if GCC_VERSION >= 30400
|
||||
#define __must_check __attribute__((warn_unused_result))
|
||||
#endif
|
||||
|
||||
#if GCC_VERSION >= 40000
|
||||
|
||||
/* GCC 4.1.[01] miscompiles __weak */
|
||||
#ifdef __KERNEL__
|
||||
# if GCC_VERSION >= 40100 && GCC_VERSION <= 40101
|
||||
# error Your version of gcc miscompiles the __weak directive
|
||||
# endif
|
||||
#endif
|
||||
|
||||
#define __used __attribute__((__used__))
|
||||
#define __compiler_offsetof(a, b) \
|
||||
__builtin_offsetof(a, b)
|
||||
|
||||
#if GCC_VERSION >= 40100 && GCC_VERSION < 40600
|
||||
# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
|
||||
#endif
|
||||
|
||||
#if GCC_VERSION >= 40300
|
||||
/* Mark functions as cold. gcc will assume any path leading to a call
|
||||
* to them will be unlikely. This means a lot of manual unlikely()s
|
||||
* are unnecessary now for any paths leading to the usual suspects
|
||||
* like BUG(), printk(), panic() etc. [but let's keep them for now for
|
||||
* older compilers]
|
||||
*
|
||||
* Early snapshots of gcc 4.3 don't support this and we can't detect this
|
||||
* in the preprocessor, but we can live with this because they're unreleased.
|
||||
* Maketime probing would be overkill here.
|
||||
*
|
||||
* gcc also has a __attribute__((__hot__)) to move hot functions into
|
||||
* a special section, but I don't see any sense in this right now in
|
||||
* the kernel context
|
||||
*/
|
||||
#define __cold __attribute__((__cold__))
|
||||
|
||||
#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
|
||||
|
||||
#ifndef __CHECKER__
|
||||
# define __compiletime_warning(message) __attribute__((warning(message)))
|
||||
# define __compiletime_error(message) __attribute__((error(message)))
|
||||
#endif /* __CHECKER__ */
|
||||
#endif /* GCC_VERSION >= 40300 */
|
||||
|
||||
#if GCC_VERSION >= 40500
|
||||
/*
|
||||
* Mark a position in code as unreachable. This can be used to
|
||||
* suppress control flow warnings after asm blocks that transfer
|
||||
* control elsewhere.
|
||||
*
|
||||
* Early snapshots of gcc 4.5 don't support this and we can't detect
|
||||
* this in the preprocessor, but we can live with this because they're
|
||||
* unreleased. Really, we need to have autoconf for the kernel.
|
||||
*/
|
||||
#define unreachable() __builtin_unreachable()
|
||||
|
||||
/* Mark a function definition as prohibited from being cloned. */
|
||||
#define __noclone __attribute__((__noclone__))
|
||||
|
||||
#endif /* GCC_VERSION >= 40500 */
|
||||
|
||||
#if GCC_VERSION >= 40600
|
||||
/*
|
||||
* Tell the optimizer that something else uses this function or variable.
|
||||
*/
|
||||
#define __visible __attribute__((externally_visible))
|
||||
#endif
|
||||
|
||||
/*
|
||||
* GCC 'asm goto' miscompiles certain code sequences:
|
||||
*
|
||||
* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
|
||||
*
|
||||
* Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
|
||||
*
|
||||
* (asm goto is automatically volatile - the naming reflects this.)
|
||||
*/
|
||||
#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
|
||||
|
||||
#ifdef CONFIG_ARCH_USE_BUILTIN_BSWAP
|
||||
#if GCC_VERSION >= 40400
|
||||
#define __HAVE_BUILTIN_BSWAP32__
|
||||
#define __HAVE_BUILTIN_BSWAP64__
|
||||
#endif
|
||||
#if GCC_VERSION >= 40800 || (defined(__powerpc__) && GCC_VERSION >= 40600)
|
||||
#define __HAVE_BUILTIN_BSWAP16__
|
||||
#endif
|
||||
#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
|
||||
|
||||
#if GCC_VERSION >= 50000
|
||||
#define KASAN_ABI_VERSION 4
|
||||
#elif GCC_VERSION >= 40902
|
||||
#define KASAN_ABI_VERSION 3
|
||||
#endif
|
||||
|
||||
#endif /* gcc version >= 40000 specific checks */
|
||||
|
||||
#if !defined(__noclone)
|
||||
#define __noclone /* not needed */
|
||||
#endif
|
||||
|
||||
/*
|
||||
* A trick to suppress uninitialized variable warning without generating any
|
||||
* code
|
||||
*/
|
||||
#define uninitialized_var(x) x = x
|
||||
|
|
|
|||
|
|
@ -1,31 +0,0 @@
|
|||
#ifndef __LINUX_COMPILER_H
|
||||
#error "Please don't include <linux/compiler-gcc3.h> directly, include <linux/compiler.h> instead."
|
||||
#endif
|
||||
|
||||
#if __GNUC_MINOR__ < 2
|
||||
# error Sorry, your compiler is too old - please upgrade it.
|
||||
#endif
|
||||
|
||||
#if __GNUC_MINOR__ >= 3
|
||||
# define __used __attribute__((__used__))
|
||||
#else
|
||||
# define __used __attribute__((__unused__))
|
||||
#endif
|
||||
|
||||
#if __GNUC_MINOR__ >= 4
|
||||
#define __must_check __attribute__((warn_unused_result))
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_GCOV_KERNEL
|
||||
# if __GNUC_MINOR__ < 4
|
||||
# error "GCOV profiling support for gcc versions below 3.4 not included"
|
||||
# endif /* __GNUC_MINOR__ */
|
||||
#endif /* CONFIG_GCOV_KERNEL */
|
||||
|
||||
/*
|
||||
* A trick to suppress uninitialized variable warning without generating any
|
||||
* code
|
||||
*/
|
||||
#define uninitialized_var(x) x = x
|
||||
|
||||
#define __always_inline inline __attribute__((always_inline))
|
||||
|
|
@ -1,61 +0,0 @@
|
|||
#ifndef __LINUX_COMPILER_H
|
||||
#error "Please don't include <linux/compiler-gcc4.h> directly, include <linux/compiler.h> instead."
|
||||
#endif
|
||||
|
||||
/* GCC 4.1.[01] miscompiles __weak */
|
||||
#ifdef __KERNEL__
|
||||
# if __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ <= 1
|
||||
# error Your version of gcc miscompiles the __weak directive
|
||||
# endif
|
||||
#endif
|
||||
|
||||
#define __used __attribute__((__used__))
|
||||
#define __must_check __attribute__((warn_unused_result))
|
||||
#define __compiler_offsetof(a,b) __builtin_offsetof(a,b)
|
||||
#define __always_inline inline __attribute__((always_inline))
|
||||
|
||||
/*
|
||||
* A trick to suppress uninitialized variable warning without generating any
|
||||
* code
|
||||
*/
|
||||
#define uninitialized_var(x) x = x
|
||||
|
||||
#if __GNUC_MINOR__ >= 3
|
||||
/* Mark functions as cold. gcc will assume any path leading to a call
|
||||
to them will be unlikely. This means a lot of manual unlikely()s
|
||||
are unnecessary now for any paths leading to the usual suspects
|
||||
like BUG(), printk(), panic() etc. [but let's keep them for now for
|
||||
older compilers]
|
||||
|
||||
Early snapshots of gcc 4.3 don't support this and we can't detect this
|
||||
in the preprocessor, but we can live with this because they're unreleased.
|
||||
Maketime probing would be overkill here.
|
||||
|
||||
gcc also has a __attribute__((__hot__)) to move hot functions into
|
||||
a special section, but I don't see any sense in this right now in
|
||||
the kernel context */
|
||||
#define __cold __attribute__((__cold__))
|
||||
|
||||
|
||||
#if __GNUC_MINOR__ >= 5
|
||||
/*
|
||||
* Mark a position in code as unreachable. This can be used to
|
||||
* suppress control flow warnings after asm blocks that transfer
|
||||
* control elsewhere.
|
||||
*
|
||||
* Early snapshots of gcc 4.5 don't support this and we can't detect
|
||||
* this in the preprocessor, but we can live with this because they're
|
||||
* unreleased. Really, we need to have autoconf for the kernel.
|
||||
*/
|
||||
#define unreachable() __builtin_unreachable()
|
||||
#endif
|
||||
|
||||
#endif
|
||||
|
||||
#if __GNUC_MINOR__ > 0
|
||||
#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
|
||||
#endif
|
||||
#if __GNUC_MINOR__ >= 4
|
||||
#define __compiletime_warning(message) __attribute__((warning(message)))
|
||||
#define __compiletime_error(message) __attribute__((error(message)))
|
||||
#endif
|
||||
|
|
@ -14,18 +14,31 @@
|
|||
* It uses intrinsics to do the equivalent things.
|
||||
*/
|
||||
#undef barrier
|
||||
#undef barrier_data
|
||||
#undef RELOC_HIDE
|
||||
#undef OPTIMIZER_HIDE_VAR
|
||||
|
||||
#define barrier() __memory_barrier()
|
||||
#define barrier_data(ptr) barrier()
|
||||
|
||||
#define RELOC_HIDE(ptr, off) \
|
||||
({ unsigned long __ptr; \
|
||||
__ptr = (unsigned long) (ptr); \
|
||||
(typeof(ptr)) (__ptr + (off)); })
|
||||
|
||||
/* This should act as an optimization barrier on var.
|
||||
* Given that this compiler does not have inline assembly, a compiler barrier
|
||||
* is the best we can do.
|
||||
*/
|
||||
#define OPTIMIZER_HIDE_VAR(var) barrier()
|
||||
|
||||
/* Intel ECC compiler doesn't support __builtin_types_compatible_p() */
|
||||
#define __must_be_array(a) 0
|
||||
|
||||
#endif
|
||||
|
||||
#define uninitialized_var(x) x
|
||||
#ifndef __HAVE_BUILTIN_BSWAP16__
|
||||
/* icc has this, but it's called _bswap16 */
|
||||
#define __HAVE_BUILTIN_BSWAP16__
|
||||
#define __builtin_bswap16 _bswap16
|
||||
#endif
|
||||
|
|
|
|||
|
|
@ -10,6 +10,7 @@
|
|||
# define __force __attribute__((force))
|
||||
# define __nocast __attribute__((nocast))
|
||||
# define __iomem __attribute__((noderef, address_space(2)))
|
||||
# define __must_hold(x) __attribute__((context(x,1,1)))
|
||||
# define __acquires(x) __attribute__((context(x,0,1)))
|
||||
# define __releases(x) __attribute__((context(x,1,0)))
|
||||
# define __acquire(x) __context__(x,1)
|
||||
|
|
@ -27,6 +28,7 @@ extern void __chk_io_ptr(const volatile void __iomem *);
|
|||
# define __chk_user_ptr(x) (void)0
|
||||
# define __chk_io_ptr(x) (void)0
|
||||
# define __builtin_warning(x, y...) (1)
|
||||
# define __must_hold(x)
|
||||
# define __acquires(x)
|
||||
# define __releases(x)
|
||||
# define __acquire(x) (void)0
|
||||
|
|
@ -34,6 +36,10 @@ extern void __chk_io_ptr(const volatile void __iomem *);
|
|||
# define __cond_lock(x,c) (c)
|
||||
#endif
|
||||
|
||||
/* Indirect macros required for expanded argument pasting, eg. __LINE__. */
|
||||
#define ___PASTE(a,b) a##b
|
||||
#define __PASTE(a,b) ___PASTE(a,b)
|
||||
|
||||
#ifdef __KERNEL__
|
||||
|
||||
#ifdef __GNUC__
|
||||
|
|
@ -49,6 +55,13 @@ extern void __chk_io_ptr(const volatile void __iomem *);
|
|||
# include <linux/compiler-intel.h>
|
||||
#endif
|
||||
|
||||
/* Clang compiler defines __GNUC__. So we will overwrite implementations
|
||||
* coming from above header files here
|
||||
*/
|
||||
#ifdef __clang__
|
||||
#include <linux/compiler-clang.h>
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Generic compiler-dependent macros required for kernel
|
||||
* build go below this comment. Actual compiler/compiler version
|
||||
|
|
@ -144,6 +157,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
|
|||
# define barrier() __memory_barrier()
|
||||
#endif
|
||||
|
||||
#ifndef barrier_data
|
||||
# define barrier_data(ptr) barrier()
|
||||
#endif
|
||||
|
||||
/* Unreachable code */
|
||||
#ifndef unreachable
|
||||
# define unreachable() do { } while (1)
|
||||
|
|
@ -156,6 +173,15 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
|
|||
(typeof(ptr)) (__ptr + (off)); })
|
||||
#endif
|
||||
|
||||
#ifndef OPTIMIZER_HIDE_VAR
|
||||
#define OPTIMIZER_HIDE_VAR(var) barrier()
|
||||
#endif
|
||||
|
||||
/* Not-quite-unique ID. */
|
||||
#ifndef __UNIQUE_ID
|
||||
# define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __LINE__)
|
||||
#endif
|
||||
|
||||
#endif /* __KERNEL__ */
|
||||
|
||||
#endif /* __ASSEMBLY__ */
|
||||
|
|
@ -228,7 +254,7 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
|
|||
|
||||
/*
|
||||
* Rather then using noinline to prevent stack consumption, use
|
||||
* noinline_for_stack instead. For documentaiton reasons.
|
||||
* noinline_for_stack instead. For documentation reasons.
|
||||
*/
|
||||
#define noinline_for_stack noinline
|
||||
|
||||
|
|
@ -270,11 +296,20 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
|
|||
# define __section(S) __attribute__ ((__section__(#S)))
|
||||
#endif
|
||||
|
||||
#ifndef __visible
|
||||
#define __visible
|
||||
#endif
|
||||
|
||||
/* Are two types/vars the same type (ignoring qualifiers)? */
|
||||
#ifndef __same_type
|
||||
# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
|
||||
#endif
|
||||
|
||||
/* Is this type a native word size -- useful for atomic operations */
|
||||
#ifndef __native_word
|
||||
# define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long))
|
||||
#endif
|
||||
|
||||
/* Compile time object size, -1 for unknown */
|
||||
#ifndef __compiletime_object_size
|
||||
# define __compiletime_object_size(obj) -1
|
||||
|
|
@ -284,7 +319,48 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
|
|||
#endif
|
||||
#ifndef __compiletime_error
|
||||
# define __compiletime_error(message)
|
||||
/*
|
||||
* Sparse complains of variable sized arrays due to the temporary variable in
|
||||
* __compiletime_assert. Unfortunately we can't just expand it out to make
|
||||
* sparse see a constant array size without breaking compiletime_assert on old
|
||||
* versions of GCC (e.g. 4.2.4), so hide the array from sparse altogether.
|
||||
*/
|
||||
# ifndef __CHECKER__
|
||||
# define __compiletime_error_fallback(condition) \
|
||||
do { ((void)sizeof(char[1 - 2 * condition])); } while (0)
|
||||
# endif
|
||||
#endif
|
||||
#ifndef __compiletime_error_fallback
|
||||
# define __compiletime_error_fallback(condition) do { } while (0)
|
||||
#endif
|
||||
|
||||
#define __compiletime_assert(condition, msg, prefix, suffix) \
|
||||
do { \
|
||||
bool __cond = !(condition); \
|
||||
extern void prefix ## suffix(void) __compiletime_error(msg); \
|
||||
if (__cond) \
|
||||
prefix ## suffix(); \
|
||||
__compiletime_error_fallback(__cond); \
|
||||
} while (0)
|
||||
|
||||
#define _compiletime_assert(condition, msg, prefix, suffix) \
|
||||
__compiletime_assert(condition, msg, prefix, suffix)
|
||||
|
||||
/**
|
||||
* compiletime_assert - break build and emit msg if condition is false
|
||||
* @condition: a compile-time constant condition to check
|
||||
* @msg: a message to emit if condition is false
|
||||
*
|
||||
* In tradition of POSIX assert, this macro will break the build if the
|
||||
* supplied condition is *false*, emitting the supplied error message if the
|
||||
* compiler has support to do so.
|
||||
*/
|
||||
#define compiletime_assert(condition, msg) \
|
||||
_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
|
||||
|
||||
#define compiletime_assert_atomic_type(t) \
|
||||
compiletime_assert(__native_word(t), \
|
||||
"Need native word sized stores/loads for atomicity.")
|
||||
|
||||
/*
|
||||
* Prevent the compiler from merging or refetching accesses. The compiler
|
||||
|
|
@ -293,11 +369,22 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
|
|||
* to make the compiler aware of ordering is to put the two invocations of
|
||||
* ACCESS_ONCE() in different C statements.
|
||||
*
|
||||
* This macro does absolutely -nothing- to prevent the CPU from reordering,
|
||||
* merging, or refetching absolutely anything at any time. Its main intended
|
||||
* use is to mediate communication between process-level code and irq/NMI
|
||||
* handlers, all running on the same CPU.
|
||||
* ACCESS_ONCE will only work on scalar types. For union types, ACCESS_ONCE
|
||||
* on a union member will work as long as the size of the member matches the
|
||||
* size of the union and the size is smaller than word size.
|
||||
*
|
||||
* The major use cases of ACCESS_ONCE used to be (1) Mediating communication
|
||||
* between process-level code and irq/NMI handlers, all running on the same CPU,
|
||||
* and (2) Ensuring that the compiler does not fold, spindle, or otherwise
|
||||
* mutilate accesses that either do not require ordering or that interact
|
||||
* with an explicit memory barrier or atomic instruction that provides the
|
||||
* required ordering.
|
||||
*
|
||||
* If possible use READ_ONCE()/WRITE_ONCE() instead.
|
||||
*/
|
||||
#define ACCESS_ONCE(x) (*(volatile typeof(x) *)&(x))
|
||||
#define __ACCESS_ONCE(x) ({ \
|
||||
__maybe_unused typeof(x) __var = (__force typeof(x)) 0; \
|
||||
(volatile typeof(x) *)&(x); })
|
||||
#define ACCESS_ONCE(x) (*__ACCESS_ONCE(x))
|
||||
|
||||
#endif /* __LINUX_COMPILER_H */
|
||||
|
|
|
|||
Loading…
Reference in New Issue