include/qemu/compiler.h

   1 /* public domain */
   2
   3 #ifndef COMPILER_H
   4 #define COMPILER_H
   5
   6 #include "config-host.h"
   7
   8 /*----------------------------------------------------------------------------
   9 | The macro QEMU_GNUC_PREREQ tests for minimum version of the GNU C compiler.
  10 | The code is a copy of SOFTFLOAT_GNUC_PREREQ, see softfloat-macros.h.
  11 *----------------------------------------------------------------------------*/
  12 #if defined(__GNUC__) && defined(__GNUC_MINOR__)
  13 # define QEMU_GNUC_PREREQ(maj, min) \
  14          ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  15 #else
  16 # define QEMU_GNUC_PREREQ(maj, min) 0
  17 #endif
  18
  19 #define QEMU_NORETURN __attribute__ ((__noreturn__))
  20
  21 #if QEMU_GNUC_PREREQ(3, 4)
  22 #define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
  23 #else
  24 #define QEMU_WARN_UNUSED_RESULT
  25 #endif
  26
  27 #if QEMU_GNUC_PREREQ(4, 0)
  28 #define QEMU_SENTINEL __attribute__((sentinel))
  29 #else
  30 #define QEMU_SENTINEL
  31 #endif
  32
  33 #if QEMU_GNUC_PREREQ(4, 3)
  34 #define QEMU_ARTIFICIAL __attribute__((always_inline, artificial))
  35 #else
  36 #define QEMU_ARTIFICIAL
  37 #endif
  38
  39 #if defined(_WIN32)
  40 # define QEMU_PACKED __attribute__((gcc_struct, packed))
  41 #else
  42 # define QEMU_PACKED __attribute__((packed))
  43 #endif
  44
  45 #ifndef glue
  46 #define xglue(x, y) x ## y
  47 #define glue(x, y) xglue(x, y)
  48 #define stringify(s)    tostring(s)
  49 #define tostring(s)     #s
  50 #endif
  51
  52 #ifndef likely
  53 #if __GNUC__ < 3
  54 #define __builtin_expect(x, n) (x)
  55 #endif
  56
  57 #define likely(x)   __builtin_expect(!!(x), 1)
  58 #define unlikely(x)   __builtin_expect(!!(x), 0)
  59 #endif
  60
  61 #ifndef container_of
  62 #define container_of(ptr, type, member) ({                      \
  63         const typeof(((type *) 0)->member) *__mptr = (ptr);     \
  64         (type *) ((char *) __mptr - offsetof(type, member));})
  65 #endif
  66
  67 /* Convert from a base type to a parent type, with compile time checking.  */
  68 #ifdef __GNUC__
  69 #define DO_UPCAST(type, field, dev) ( __extension__ ( { \
  70     char __attribute__((unused)) offset_must_be_zero[ \
  71         -offsetof(type, field)]; \
  72     container_of(dev, type, field);}))
  73 #else
  74 #define DO_UPCAST(type, field, dev) container_of(dev, type, field)
  75 #endif
  76
  77 #define typeof_field(type, field) typeof(((type *)0)->field)
  78 #define type_check(t1,t2) ((t1*)0 - (t2*)0)
  79
  80 #ifndef always_inline
  81 #if !((__GNUC__ < 3) || defined(__APPLE__))
  82 #ifdef __OPTIMIZE__
  83 #undef inline
  84 #define inline __attribute__ (( always_inline )) __inline__
  85 #endif
  86 #endif
  87 #else
  88 #undef inline
  89 #define inline always_inline
  90 #endif
  91
  92 #define QEMU_BUILD_BUG_ON(x) \
  93     typedef char glue(qemu_build_bug_on__,__LINE__)[(x)?-1:1] __attribute__((unused));
  94
  95 #if defined __GNUC__
  96 # if !QEMU_GNUC_PREREQ(4, 4)
  97    /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
  98 #  define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m)))
  99 # else
 100    /* Use gnu_printf when supported (qemu uses standard format strings). */
 101 #  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
 102 #  if defined(_WIN32)
 103     /* Map __printf__ to __gnu_printf__ because we want standard format strings
 104      * even when MinGW or GLib include files use __printf__. */
 105 #   define __printf__ __gnu_printf__
 106 #  endif
 107 # endif
 108 #else
 109 #define GCC_FMT_ATTR(n, m)
 110 #endif
 111
 112 #endif /* COMPILER_H */