1/*
2 If G_HAS_CONSTRUCTORS is true then the compiler support *both* constructors and
3 destructors, in a usable 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#include <stdlib.h>
32
33#define G_HAS_CONSTRUCTORS 1
34
35/* We do some weird things to avoid the constructors being optimized
36 * away on VS2015 if WholeProgramOptimization is enabled. First we
37 * make a reference to the array from the wrapper to make sure its
38 * references. Then we use a pragma to make sure the wrapper function
39 * symbol is always included at the link stage. Also, the symbols
40 * need to be extern (but not dllexport), even though they are not
41 * really used from another object file.
42 */
43
44/* We need to account for differences between the mangling of symbols
45 * for x86 and x64/ARM/ARM64 programs, as symbols on x86 are prefixed
46 * with an underscore but symbols on x64/ARM/ARM64 are not.
47 */
48#ifdef _M_IX86
49#define G_MSVC_SYMBOL_PREFIX "_"
50#else
51#define G_MSVC_SYMBOL_PREFIX ""
52#endif
53
54#define G_DEFINE_CONSTRUCTOR(_func) G_MSVC_CTOR (_func, G_MSVC_SYMBOL_PREFIX)
55#define G_DEFINE_DESTRUCTOR(_func) G_MSVC_DTOR (_func, G_MSVC_SYMBOL_PREFIX)
56
57#define G_MSVC_CTOR(_func,_sym_prefix) \
58 static void _func(void); \
59 extern int (* _array ## _func)(void); \
60 int _func ## _wrapper(void) { _func(); g_slist_find (NULL, _array ## _func); return 0; } \
61 __pragma(comment(linker,"/include:" _sym_prefix # _func "_wrapper")) \
62 __pragma(section(".CRT$XCU",read)) \
63 __declspec(allocate(".CRT$XCU")) int (* _array ## _func)(void) = _func ## _wrapper;
64
65#define G_MSVC_DTOR(_func,_sym_prefix) \
66 static void _func(void); \
67 extern int (* _array ## _func)(void); \
68 int _func ## _constructor(void) { atexit (_func); g_slist_find (NULL, _array ## _func); return 0; } \
69 __pragma(comment(linker,"/include:" _sym_prefix # _func "_constructor")) \
70 __pragma(section(".CRT$XCU",read)) \
71 __declspec(allocate(".CRT$XCU")) int (* _array ## _func)(void) = _func ## _constructor;
72
73#elif defined (_MSC_VER)
74
75#define G_HAS_CONSTRUCTORS 1
76
77/* Pre Visual studio 2008 must use #pragma section */
78#define G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA 1
79#define G_DEFINE_DESTRUCTOR_NEEDS_PRAGMA 1
80
81#define G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(_func) \
82 section(".CRT$XCU",read)
83#define G_DEFINE_CONSTRUCTOR(_func) \
84 static void _func(void); \
85 static int _func ## _wrapper(void) { _func(); return 0; } \
86 __declspec(allocate(".CRT$XCU")) static int (*p)(void) = _func ## _wrapper;
87
88#define G_DEFINE_DESTRUCTOR_PRAGMA_ARGS(_func) \
89 section(".CRT$XCU",read)
90#define G_DEFINE_DESTRUCTOR(_func) \
91 static void _func(void); \
92 static int _func ## _constructor(void) { atexit (_func); return 0; } \
93 __declspec(allocate(".CRT$XCU")) static int (* _array ## _func)(void) = _func ## _constructor;
94
95#elif defined(__SUNPRO_C)
96
97/* This is not tested, but i believe it should work, based on:
98 * http://opensource.apple.com/source/OpenSSL098/OpenSSL098-35/src/fips/fips_premain.c
99 */
100
101#define G_HAS_CONSTRUCTORS 1
102
103#define G_DEFINE_CONSTRUCTOR_NEEDS_PRAGMA 1
104#define G_DEFINE_DESTRUCTOR_NEEDS_PRAGMA 1
105
106#define G_DEFINE_CONSTRUCTOR_PRAGMA_ARGS(_func) \
107 init(_func)
108#define G_DEFINE_CONSTRUCTOR(_func) \
109 static void _func(void);
110
111#define G_DEFINE_DESTRUCTOR_PRAGMA_ARGS(_func) \
112 fini(_func)
113#define G_DEFINE_DESTRUCTOR(_func) \
114 static void _func(void);
115
116#else
117
118/* constructors not supported for this compiler */
119
120#endif
121
122#endif /* __GTK_DOC_IGNORE__ */
123

source code of gtk/subprojects/glib/glib/gconstructor.h