glib/gconstructor.h

   1 /*
   2   If G_HAS_CONSTRUCTORS is true then the compiler support *both* constructors and
   3   destructors, in a sane way, including e.g. on library unload. If not you're on
   4   your own.
   5
   6   Some compilers need #pragma to handle this, which does not work with macros,
   7   so the way you need to use this is (for constructors):
   8
   9   #ifdef G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA
  10   #pragma G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(my_constructor)
  11   #endif
  12   G_DEFINE_CONSTRUCTOR(my_constructor)
  13   static void my_constructor(void) {
  14    ...
  15   }
  16
  17 */
  18
  19 #ifndef __GTK_DOC_IGNORE__
  20
  21 #if  __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
  22
  23 #define G_HAS_CONSTRUCTORS 1
  24
  25 #define G_DEFINE_CONSTRUCTOR(_func) static void __attribute__((constructor)) _func (void);
  26 #define G_DEFINE_DESTRUCTOR(_func) static void __attribute__((destructor)) _func (void);
  27
  28 #elif defined (_MSC_VER) && (_MSC_VER >= 1500)
  29 /* Visual studio 2008 and later has _Pragma */
  30
  31 #define G_HAS_CONSTRUCTORS 1
  32
  33 /* We do some weird things to avoid the constructors being optimized
  34  * away on VS2015 if WholeProgramOptimization is enabled. First we
  35  * make a reference to the array from the wrapper to make sure its
  36  * references. Then we use a pragma to make sure the wrapper function
  37  * symbol is always included at the link stage. Also, the symbols
  38  * need to be extern (but not dllexport), even though they are not
  39  * really used from another object file.
  40  */
  41
  42 /* We need to account for differences between the mangling of symbols
  43  * for Win32 (x86) and x64 programs, as symbols on Win32 are prefixed
  44  * with an underscore but symbols on x64 are not.
  45  */
  46 #ifdef _WIN64
  47 #define G_MSVC_SYMBOL_PREFIX ""
  48 #else
  49 #define G_MSVC_SYMBOL_PREFIX "_"
  50 #endif
  51
  52 #define G_DEFINE_CONSTRUCTOR(_func) G_MSVC_CTOR (_func, G_MSVC_SYMBOL_PREFIX)
  53 #define G_DEFINE_DESTRUCTOR(_func) G_MSVC_DTOR (_func, G_MSVC_SYMBOL_PREFIX)
  54
  55 #define G_MSVC_CTOR(_func,_sym_prefix) \
  56   static void _func(void); \
  57   extern int (* _array ## _func)(void);              \
  58   int _func ## _wrapper(void) { _func(); g_slist_find (NULL,  _array ## _func); return 0; } \
  59   __pragma(comment(linker,"/include:" _sym_prefix # _func "_wrapper")) \
  60   __pragma(section(".CRT$XCU",read)) \
  61   __declspec(allocate(".CRT$XCU")) int (* _array ## _func)(void) = _func ## _wrapper;
  62
  63 #define G_MSVC_DTOR(_func,_sym_prefix) \
  64   static void _func(void); \
  65   extern int (* _array ## _func)(void);              \
  66   int _func ## _constructor(void) { atexit (_func); g_slist_find (NULL,  _array ## _func); return 0; } \
  67    __pragma(comment(linker,"/include:" _sym_prefix # _func "_constructor")) \
  68   __pragma(section(".CRT$XCU",read)) \
  69   __declspec(allocate(".CRT$XCU")) int (* _array ## _func)(void) = _func ## _constructor;
  70
  71 #elif defined (_MSC_VER)
  72
  73 #define G_HAS_CONSTRUCTORS 1
  74
  75 /* Pre Visual studio 2008 must use #pragma section */
  76 #define G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA 1
  77 #define G_DEFINE_DESTRUCTOR_NEEDS_PRAGMA 1
  78
  79 #define G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(_func) \
  80   section(".CRT$XCU",read)
  81 #define G_DEFINE_CONSTRUCTOR(_func) \
  82   static void _func(void); \
  83   static int _func ## _wrapper(void) { _func(); return 0; } \
  84   __declspec(allocate(".CRT$XCU")) static int (*p)(void) = _func ## _wrapper;
  85
  86 #define G_DEFINE_DESTRUCTOR_PRAGMA_ARGS(_func) \
  87   section(".CRT$XCU",read)
  88 #define G_DEFINE_DESTRUCTOR(_func) \
  89   static void _func(void); \
  90   static int _func ## _constructor(void) { atexit (_func); return 0; } \
  91   __declspec(allocate(".CRT$XCU")) static int (* _array ## _func)(void) = _func ## _constructor;
  92
  93 #elif defined(__SUNPRO_C)
  94
  95 /* This is not tested, but i believe it should work, based on:
  96  * http://opensource.apple.com/source/OpenSSL098/OpenSSL098-35/src/fips/fips_premain.c
  97  */
  98
  99 #define G_HAS_CONSTRUCTORS 1
 100
 101 #define G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA 1
 102 #define G_DEFINE_DESTRUCTOR_NEEDS_PRAGMA 1
 103
 104 #define G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(_func) \
 105   init(_func)
 106 #define G_DEFINE_CONSTRUCTOR(_func) \
 107   static void _func(void);
 108
 109 #define G_DEFINE_DESTRUCTOR_PRAGMA_ARGS(_func) \
 110   fini(_func)
 111 #define G_DEFINE_DESTRUCTOR(_func) \
 112   static void _func(void);
 113
 114 #else
 115
 116 /* constructors not supported for this compiler */
 117
 118 #endif
 119
 120 #endif /* __GTK_DOC_IGNORE__ */