 798b858130
			
		
	
	
		798b858130
		
	
	
	
	
		
			
			Clang version 3.4.2 does not know the -Wpragmas option yet and bails out with an error when we try to disable it in linux-user/qemu.h. Fortunately, clang has a __has_warning() macro which allows us to add an explicit check for the option that we want to ignore. With that we can check for the availability of "-Waddress-of-packed-member" properly and do not need the "-Wpragmas" at all here. Fixes: 850d5e330a9c68cc998cecc02caf8a3c8d1ee8a3 Reviewed-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Thomas Huth <thuth@redhat.com>
		
			
				
	
	
		
			214 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			214 lines
		
	
	
		
			7.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* compiler.h: macros to abstract away compiler specifics
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|  *
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|  * This work is licensed under the terms of the GNU GPL, version 2 or later.
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|  * See the COPYING file in the top-level directory.
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|  */
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| 
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| #ifndef COMPILER_H
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| #define COMPILER_H
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| 
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| #if defined __clang_analyzer__ || defined __COVERITY__
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| #define QEMU_STATIC_ANALYSIS 1
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| #endif
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| 
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| /*----------------------------------------------------------------------------
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| | The macro QEMU_GNUC_PREREQ tests for minimum version of the GNU C compiler.
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| | The code is a copy of SOFTFLOAT_GNUC_PREREQ, see softfloat-macros.h.
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| *----------------------------------------------------------------------------*/
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| #if defined(__GNUC__) && defined(__GNUC_MINOR__)
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| # define QEMU_GNUC_PREREQ(maj, min) \
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|          ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
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| #else
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| # define QEMU_GNUC_PREREQ(maj, min) 0
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| #endif
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| 
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| #define QEMU_NORETURN __attribute__ ((__noreturn__))
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| 
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| #define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
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| 
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| #define QEMU_SENTINEL __attribute__((sentinel))
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| 
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| #if defined(_WIN32)
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| # define QEMU_PACKED __attribute__((gcc_struct, packed))
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| #else
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| # define QEMU_PACKED __attribute__((packed))
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| #endif
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| 
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| #define QEMU_ALIGNED(X) __attribute__((aligned(X)))
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| 
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| #ifndef glue
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| #define xglue(x, y) x ## y
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| #define glue(x, y) xglue(x, y)
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| #define stringify(s)	tostring(s)
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| #define tostring(s)	#s
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| #endif
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| 
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| #ifndef likely
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| #if __GNUC__ < 3
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| #define __builtin_expect(x, n) (x)
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| #endif
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| 
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| #define likely(x)   __builtin_expect(!!(x), 1)
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| #define unlikely(x)   __builtin_expect(!!(x), 0)
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| #endif
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| 
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| #ifndef container_of
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| #define container_of(ptr, type, member) ({                      \
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|         const typeof(((type *) 0)->member) *__mptr = (ptr);     \
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|         (type *) ((char *) __mptr - offsetof(type, member));})
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| #endif
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| 
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| #define sizeof_field(type, field) sizeof(((type *)0)->field)
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| 
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| /* Convert from a base type to a parent type, with compile time checking.  */
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| #ifdef __GNUC__
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| #define DO_UPCAST(type, field, dev) ( __extension__ ( { \
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|     char __attribute__((unused)) offset_must_be_zero[ \
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|         -offsetof(type, field)]; \
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|     container_of(dev, type, field);}))
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| #else
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| #define DO_UPCAST(type, field, dev) container_of(dev, type, field)
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| #endif
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| 
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| #define typeof_field(type, field) typeof(((type *)0)->field)
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| #define type_check(t1,t2) ((t1*)0 - (t2*)0)
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| 
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| #define QEMU_BUILD_BUG_ON_STRUCT(x) \
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|     struct { \
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|         int:(x) ? -1 : 1; \
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|     }
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| 
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| /* QEMU_BUILD_BUG_MSG() emits the message given if _Static_assert is
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|  * supported; otherwise, it will be omitted from the compiler error
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|  * message (but as it remains present in the source code, it can still
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|  * be useful when debugging). */
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| #if defined(CONFIG_STATIC_ASSERT)
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| #define QEMU_BUILD_BUG_MSG(x, msg) _Static_assert(!(x), msg)
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| #elif defined(__COUNTER__)
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| #define QEMU_BUILD_BUG_MSG(x, msg) typedef QEMU_BUILD_BUG_ON_STRUCT(x) \
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|     glue(qemu_build_bug_on__, __COUNTER__) __attribute__((unused))
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| #else
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| #define QEMU_BUILD_BUG_MSG(x, msg)
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| #endif
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| 
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| #define QEMU_BUILD_BUG_ON(x) QEMU_BUILD_BUG_MSG(x, "not expecting: " #x)
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| 
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| #define QEMU_BUILD_BUG_ON_ZERO(x) (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \
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|                                    sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)))
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| 
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| #if defined __GNUC__
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| # if !QEMU_GNUC_PREREQ(4, 4)
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|    /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
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| #  define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m)))
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| # else
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|    /* Use gnu_printf when supported (qemu uses standard format strings). */
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| #  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
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| #  if defined(_WIN32)
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|     /* Map __printf__ to __gnu_printf__ because we want standard format strings
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|      * even when MinGW or GLib include files use __printf__. */
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| #   define __printf__ __gnu_printf__
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| #  endif
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| # endif
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| #else
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| #define GCC_FMT_ATTR(n, m)
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| #endif
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| 
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| #ifndef __has_warning
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| #define __has_warning(x) 0 /* compatibility with non-clang compilers */
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| #endif
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| 
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| #ifndef __has_feature
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| #define __has_feature(x) 0 /* compatibility with non-clang compilers */
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| #endif
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| 
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| #ifndef __has_builtin
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| #define __has_builtin(x) 0 /* compatibility with non-clang compilers */
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| #endif
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| 
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| #if __has_builtin(__builtin_assume_aligned) || !defined(__clang__)
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| #define HAS_ASSUME_ALIGNED
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| #endif
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| 
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| #ifndef __has_attribute
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| #define __has_attribute(x) 0 /* compatibility with older GCC */
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| #endif
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| 
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| /*
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|  * GCC doesn't provide __has_attribute() until GCC 5, but we know all the GCC
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|  * versions we support have the "flatten" attribute. Clang may not have the
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|  * "flatten" attribute but always has __has_attribute() to check for it.
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|  */
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| #if __has_attribute(flatten) || !defined(__clang__)
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| # define QEMU_FLATTEN __attribute__((flatten))
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| #else
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| # define QEMU_FLATTEN
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| #endif
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| 
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| /*
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|  * If __attribute__((error)) is present, use it to produce an error at
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|  * compile time.  Otherwise, one must wait for the linker to diagnose
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|  * the missing symbol.
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|  */
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| #if __has_attribute(error)
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| # define QEMU_ERROR(X) __attribute__((error(X)))
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| #else
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| # define QEMU_ERROR(X)
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| #endif
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| 
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| /*
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|  * The nonstring variable attribute specifies that an object or member
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|  * declaration with type array of char or pointer to char is intended
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|  * to store character arrays that do not necessarily contain a terminating
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|  * NUL character. This is useful in detecting uses of such arrays or pointers
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|  * with functions that expect NUL-terminated strings, and to avoid warnings
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|  * when such an array or pointer is used as an argument to a bounded string
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|  * manipulation function such as strncpy.
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|  */
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| #if __has_attribute(nonstring)
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| # define QEMU_NONSTRING __attribute__((nonstring))
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| #else
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| # define QEMU_NONSTRING
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| #endif
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| 
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| /* Implement C11 _Generic via GCC builtins.  Example:
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|  *
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|  *    QEMU_GENERIC(x, (float, sinf), (long double, sinl), sin) (x)
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|  *
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|  * The first argument is the discriminator.  The last is the default value.
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|  * The middle ones are tuples in "(type, expansion)" format.
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|  */
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| 
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| /* First, find out the number of generic cases.  */
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| #define QEMU_GENERIC(x, ...) \
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|     QEMU_GENERIC_(typeof(x), __VA_ARGS__, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
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| 
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| /* There will be extra arguments, but they are not used.  */
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| #define QEMU_GENERIC_(x, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, count, ...) \
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|     QEMU_GENERIC##count(x, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9)
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| 
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| /* Two more helper macros, this time to extract items from a parenthesized
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|  * list.
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|  */
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| #define QEMU_FIRST_(a, b) a
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| #define QEMU_SECOND_(a, b) b
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| 
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| /* ... and a final one for the common part of the "recursion".  */
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| #define QEMU_GENERIC_IF(x, type_then, else_)                                   \
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|     __builtin_choose_expr(__builtin_types_compatible_p(x,                      \
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|                                                        QEMU_FIRST_ type_then), \
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|                           QEMU_SECOND_ type_then, else_)
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| 
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| /* CPP poor man's "recursion".  */
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| #define QEMU_GENERIC1(x, a0, ...) (a0)
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| #define QEMU_GENERIC2(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC1(x, __VA_ARGS__))
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| #define QEMU_GENERIC3(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC2(x, __VA_ARGS__))
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| #define QEMU_GENERIC4(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC3(x, __VA_ARGS__))
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| #define QEMU_GENERIC5(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC4(x, __VA_ARGS__))
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| #define QEMU_GENERIC6(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC5(x, __VA_ARGS__))
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| #define QEMU_GENERIC7(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC6(x, __VA_ARGS__))
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| #define QEMU_GENERIC8(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC7(x, __VA_ARGS__))
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| #define QEMU_GENERIC9(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC8(x, __VA_ARGS__))
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| #define QEMU_GENERIC10(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC9(x, __VA_ARGS__))
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| 
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| #endif /* COMPILER_H */
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