LXR qemu/include/qemu/compiler.h

   1/* public domain */
   2
   3#ifndef COMPILER_H
   4#define COMPILER_H
   5
   6
   7/*----------------------------------------------------------------------------
   8| The macro QEMU_GNUC_PREREQ tests for minimum version of the GNU C compiler.
   9| The code is a copy of SOFTFLOAT_GNUC_PREREQ, see softfloat-macros.h.
  10*----------------------------------------------------------------------------*/
  11#if defined(__GNUC__) && defined(__GNUC_MINOR__)
  12# define QEMU_GNUC_PREREQ(maj, min) \
  13         ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  14#else
  15# define QEMU_GNUC_PREREQ(maj, min) 0
  16#endif
  17
  18#define QEMU_NORETURN __attribute__ ((__noreturn__))
  19
  20#if QEMU_GNUC_PREREQ(3, 4)
  21#define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
  22#else
  23#define QEMU_WARN_UNUSED_RESULT
  24#endif
  25
  26#if QEMU_GNUC_PREREQ(4, 0)
  27#define QEMU_SENTINEL __attribute__((sentinel))
  28#else
  29#define QEMU_SENTINEL
  30#endif
  31
  32#if QEMU_GNUC_PREREQ(4, 3)
  33#define QEMU_ARTIFICIAL __attribute__((always_inline, artificial))
  34#else
  35#define QEMU_ARTIFICIAL
  36#endif
  37
  38#if defined(_WIN32)
  39# define QEMU_PACKED __attribute__((gcc_struct, packed))
  40#else
  41# define QEMU_PACKED __attribute__((packed))
  42#endif
  43
  44#ifndef glue
  45#define xglue(x, y) x ## y
  46#define glue(x, y) xglue(x, y)
  47#define stringify(s)    tostring(s)
  48#define tostring(s)     #s
  49#endif
  50
  51#ifndef likely
  52#if __GNUC__ < 3
  53#define __builtin_expect(x, n) (x)
  54#endif
  55
  56#define likely(x)   __builtin_expect(!!(x), 1)
  57#define unlikely(x)   __builtin_expect(!!(x), 0)
  58#endif
  59
  60#ifndef container_of
  61#define container_of(ptr, type, member) ({                      \
  62        const typeof(((type *) 0)->member) *__mptr = (ptr);     \
  63        (type *) ((char *) __mptr - offsetof(type, member));})
  64#endif
  65
  66/* Convert from a base type to a parent type, with compile time checking.  */
  67#ifdef __GNUC__
  68#define DO_UPCAST(type, field, dev) ( __extension__ ( { \
  69    char __attribute__((unused)) offset_must_be_zero[ \
  70        -offsetof(type, field)]; \
  71    container_of(dev, type, field);}))
  72#else
  73#define DO_UPCAST(type, field, dev) container_of(dev, type, field)
  74#endif
  75
  76#define typeof_field(type, field) typeof(((type *)0)->field)
  77#define type_check(t1,t2) ((t1*)0 - (t2*)0)
  78
  79#define QEMU_BUILD_BUG_ON(x) \
  80    typedef char glue(qemu_build_bug_on__,__LINE__)[(x)?-1:1] __attribute__((unused));
  81
  82#if defined __GNUC__
  83# if !QEMU_GNUC_PREREQ(4, 4)
  84   /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
  85#  define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m)))
  86# else
  87   /* Use gnu_printf when supported (qemu uses standard format strings). */
  88#  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
  89#  if defined(_WIN32)
  90    /* Map __printf__ to __gnu_printf__ because we want standard format strings
  91     * even when MinGW or GLib include files use __printf__. */
  92#   define __printf__ __gnu_printf__
  93#  endif
  94# endif
  95#else
  96#define GCC_FMT_ATTR(n, m)
  97#endif
  98
  99#endif /* COMPILER_H */
 100