include/qemu/compiler.h

   1 /* compiler.h: macros to abstract away compiler specifics
   2  *
   3  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   4  * See the COPYING file in the top-level directory.
   5  */
   6
   7 #ifndef COMPILER_H
   8 #define COMPILER_H
   9
  10 #if defined __clang_analyzer__ || defined __COVERITY__
  11 #define QEMU_STATIC_ANALYSIS 1
  12 #endif
  13
  14 /*----------------------------------------------------------------------------
  15 | The macro QEMU_GNUC_PREREQ tests for minimum version of the GNU C compiler.
  16 | The code is a copy of SOFTFLOAT_GNUC_PREREQ, see softfloat-macros.h.
  17 *----------------------------------------------------------------------------*/
  18 #if defined(__GNUC__) && defined(__GNUC_MINOR__)
  19 # define QEMU_GNUC_PREREQ(maj, min) \
  20          ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
  21 #else
  22 # define QEMU_GNUC_PREREQ(maj, min) 0
  23 #endif
  24
  25 #define QEMU_NORETURN __attribute__ ((__noreturn__))
  26
  27 #define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
  28
  29 #define QEMU_SENTINEL __attribute__((sentinel))
  30
  31 #if QEMU_GNUC_PREREQ(4, 3)
  32 #define QEMU_ARTIFICIAL __attribute__((always_inline, artificial))
  33 #else
  34 #define QEMU_ARTIFICIAL
  35 #endif
  36
  37 #if defined(_WIN32)
  38 # define QEMU_PACKED __attribute__((gcc_struct, packed))
  39 #else
  40 # define QEMU_PACKED __attribute__((packed))
  41 #endif
  42
  43 #define QEMU_ALIGNED(X) __attribute__((aligned(X)))
  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 #define QEMU_BUILD_BUG_ON_STRUCT(x) \
  81     struct { \
  82         int:(x) ? -1 : 1; \
  83     }
  84
  85 #if defined(CONFIG_STATIC_ASSERT)
  86 #define QEMU_BUILD_BUG_ON(x) _Static_assert(!(x), "not expecting: " #x)
  87 #elif defined(__COUNTER__)
  88 #define QEMU_BUILD_BUG_ON(x) typedef QEMU_BUILD_BUG_ON_STRUCT(x) \
  89     glue(qemu_build_bug_on__, __COUNTER__) __attribute__((unused))
  90 #else
  91 #define QEMU_BUILD_BUG_ON(x)
  92 #endif
  93
  94 #define QEMU_BUILD_BUG_ON_ZERO(x) (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - \
  95                                    sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)))
  96
  97 #if defined __GNUC__
  98 # if !QEMU_GNUC_PREREQ(4, 4)
  99    /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
 100 #  define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m)))
 101 # else
 102    /* Use gnu_printf when supported (qemu uses standard format strings). */
 103 #  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
 104 #  if defined(_WIN32)
 105     /* Map __printf__ to __gnu_printf__ because we want standard format strings
 106      * even when MinGW or GLib include files use __printf__. */
 107 #   define __printf__ __gnu_printf__
 108 #  endif
 109 # endif
 110 #else
 111 #define GCC_FMT_ATTR(n, m)
 112 #endif
 113
 114 #endif /* COMPILER_H */