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 #define QEMU_ALIGNED(X) __attribute__((aligned(X)))
  45
  46 #ifndef glue
  47 #define xglue(x, y) x ## y
  48 #define glue(x, y) xglue(x, y)
  49 #define stringify(s)    tostring(s)
  50 #define tostring(s)     #s
  51 #endif
  52
  53 #ifndef likely
  54 #if __GNUC__ < 3
  55 #define __builtin_expect(x, n) (x)
  56 #endif
  57
  58 #define likely(x)   __builtin_expect(!!(x), 1)
  59 #define unlikely(x)   __builtin_expect(!!(x), 0)
  60 #endif
  61
  62 #ifndef container_of
  63 #define container_of(ptr, type, member) ({                      \
  64         const typeof(((type *) 0)->member) *__mptr = (ptr);     \
  65         (type *) ((char *) __mptr - offsetof(type, member));})
  66 #endif
  67
  68 /* Convert from a base type to a parent type, with compile time checking.  */
  69 #ifdef __GNUC__
  70 #define DO_UPCAST(type, field, dev) ( __extension__ ( { \
  71     char __attribute__((unused)) offset_must_be_zero[ \
  72         -offsetof(type, field)]; \
  73     container_of(dev, type, field);}))
  74 #else
  75 #define DO_UPCAST(type, field, dev) container_of(dev, type, field)
  76 #endif
  77
  78 #define typeof_field(type, field) typeof(((type *)0)->field)
  79 #define type_check(t1,t2) ((t1*)0 - (t2*)0)
  80
  81 #define QEMU_BUILD_BUG_ON(x) \
  82     typedef char glue(qemu_build_bug_on__,__LINE__)[(x)?-1:1] __attribute__((unused));
  83
  84 #if defined __GNUC__
  85 # if !QEMU_GNUC_PREREQ(4, 4)
  86    /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
  87 #  define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m)))
  88 # else
  89    /* Use gnu_printf when supported (qemu uses standard format strings). */
  90 #  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
  91 #  if defined(_WIN32)
  92     /* Map __printf__ to __gnu_printf__ because we want standard format strings
  93      * even when MinGW or GLib include files use __printf__. */
  94 #   define __printf__ __gnu_printf__
  95 #  endif
  96 # endif
  97 #else
  98 #define GCC_FMT_ATTR(n, m)
  99 #endif
 100
 101 #endif /* COMPILER_H */