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 #if QEMU_GNUC_PREREQ(3, 4)
  28 #define QEMU_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
  29 #else
  30 #define QEMU_WARN_UNUSED_RESULT
  31 #endif
  32
  33 #if QEMU_GNUC_PREREQ(4, 0)
  34 #define QEMU_SENTINEL __attribute__((sentinel))
  35 #else
  36 #define QEMU_SENTINEL
  37 #endif
  38
  39 #if QEMU_GNUC_PREREQ(4, 3)
  40 #define QEMU_ARTIFICIAL __attribute__((always_inline, artificial))
  41 #else
  42 #define QEMU_ARTIFICIAL
  43 #endif
  44
  45 #if defined(_WIN32)
  46 # define QEMU_PACKED __attribute__((gcc_struct, packed))
  47 #else
  48 # define QEMU_PACKED __attribute__((packed))
  49 #endif
  50
  51 #define QEMU_ALIGNED(X) __attribute__((aligned(X)))
  52
  53 #ifndef glue
  54 #define xglue(x, y) x ## y
  55 #define glue(x, y) xglue(x, y)
  56 #define stringify(s)    tostring(s)
  57 #define tostring(s)     #s
  58 #endif
  59
  60 #ifndef likely
  61 #if __GNUC__ < 3
  62 #define __builtin_expect(x, n) (x)
  63 #endif
  64
  65 #define likely(x)   __builtin_expect(!!(x), 1)
  66 #define unlikely(x)   __builtin_expect(!!(x), 0)
  67 #endif
  68
  69 #ifndef container_of
  70 #define container_of(ptr, type, member) ({                      \
  71         const typeof(((type *) 0)->member) *__mptr = (ptr);     \
  72         (type *) ((char *) __mptr - offsetof(type, member));})
  73 #endif
  74
  75 /* Convert from a base type to a parent type, with compile time checking.  */
  76 #ifdef __GNUC__
  77 #define DO_UPCAST(type, field, dev) ( __extension__ ( { \
  78     char __attribute__((unused)) offset_must_be_zero[ \
  79         -offsetof(type, field)]; \
  80     container_of(dev, type, field);}))
  81 #else
  82 #define DO_UPCAST(type, field, dev) container_of(dev, type, field)
  83 #endif
  84
  85 #define typeof_field(type, field) typeof(((type *)0)->field)
  86 #define type_check(t1,t2) ((t1*)0 - (t2*)0)
  87
  88 #define QEMU_BUILD_BUG_ON(x) \
  89     typedef char glue(qemu_build_bug_on__,__LINE__)[(x)?-1:1] __attribute__((unused));
  90
  91 #if defined __GNUC__
  92 # if !QEMU_GNUC_PREREQ(4, 4)
  93    /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
  94 #  define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m)))
  95 # else
  96    /* Use gnu_printf when supported (qemu uses standard format strings). */
  97 #  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
  98 #  if defined(_WIN32)
  99     /* Map __printf__ to __gnu_printf__ because we want standard format strings
 100      * even when MinGW or GLib include files use __printf__. */
 101 #   define __printf__ __gnu_printf__
 102 #  endif
 103 # endif
 104 #else
 105 #define GCC_FMT_ATTR(n, m)
 106 #endif
 107
 108 #endif /* COMPILER_H */