GNU libmicrohttpd  1.0.1
autoinit_funcs.h
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1 /*
2  * AutoinitFuncs: Automatic Initialization and Deinitialization Functions
3  * Copyright(C) 2014-2023 Karlson2k (Evgeny Grin)
4  *
5  * This header is free software; you can redistribute it and / or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * This header is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this header; if not, see
17  * <http://www.gnu.org/licenses/>.
18  */
19 
20 /*
21  General usage is simple: include this header, declare or define two
22  functions with zero parameters (void) and any return type: one for
23  initialisation and one for deinitialisation, add
24  _SET_INIT_AND_DEINIT_FUNCS(FuncInitName, FuncDeInitName) to the code
25  and functions will be automatically called during application startup
26  and shutdown.
27  This is useful for libraries as libraries don't have direct access
28  to main() functions.
29  Example:
30  -------------------------------------------------
31  #include <stdlib.h>
32  #include "autoinit_funcs.h"
33 
34  int someVar;
35  void* somePtr;
36 
37  void libInit(void)
38  {
39  someVar = 3;
40  somePtr = malloc(100);
41  }
42 
43  void libDeinit(void)
44  {
45  free(somePtr);
46  }
47 
48  _SET_INIT_AND_DEINIT_FUNCS(libInit,libDeinit);
49  -------------------------------------------------
50 
51  If initialiser or deinitialiser function is not needed, just define
52  it as empty function.
53 
54  This header should work with GCC, clang, MSVC (2010 or later) and
55  SunPro / Sun Studio / Oracle Solaris Studio / Oracle Developer Studio
56  compiler.
57  Supported C and C++ languages; application, static and dynamic (DLL)
58  libraries; non-optimized (Debug) and optimised (Release) compilation
59  and linking.
60 
61  For more information see header code and comments in code.
62  */
63 #ifndef AUTOINIT_FUNCS_INCLUDED
64 #define AUTOINIT_FUNCS_INCLUDED 1
65 
70 #define AUTOINIT_FUNCS_VERSION 0x01001000
71 
72 #if defined(__GNUC__) || defined(__clang__)
73 /* if possible - check for supported attribute */
74 #ifdef __has_attribute
75 #if ! __has_attribute (constructor) || ! __has_attribute (destructor)
76 #define _GNUC_ATTR_CONSTR_NOT_SUPPORTED 1
77 #endif /* !__has_attribute(constructor) || !__has_attribute(destructor) */
78 #endif /* __has_attribute */
79 #endif /* __GNUC__ */
80 
81 /* "__has_attribute__ ((constructor))" is supported by GCC, clang and
82  Sun/Oracle compiler starting from version 12.1. */
83 #if ((defined(__GNUC__) || defined(__clang__)) && \
84  ! defined(_GNUC_ATTR_CONSTR_NOT_SUPPORTED)) || \
85  (defined(__SUNPRO_C) && __SUNPRO_C + 0 >= 0x5100)
86 
87 #define GNUC_SET_INIT_AND_DEINIT(FI,FD) \
88  void __attribute__ ((constructor)) _GNUC_init_helper_ ## FI (void); \
89  void __attribute__ ((destructor)) _GNUC_deinit_helper_ ## FD (void); \
90  void __attribute__ ((constructor)) _GNUC_init_helper_ ## FI (void) \
91  { (void) (FI) (); } \
92  void __attribute__ ((destructor)) _GNUC_deinit_helper_ ## FD (void) \
93  { (void) (FD) (); } \
94  struct _GNUC_dummy_str_ ## FI {int i;}
95 
96 #define _SET_INIT_AND_DEINIT_FUNCS(FI,FD) GNUC_SET_INIT_AND_DEINIT (FI,FD)
97 #define _AUTOINIT_FUNCS_ARE_SUPPORTED 1
98 
99 #elif defined(_MSC_FULL_VER) && _MSC_VER + 0 >= 1600
100 
101 /* Make sure that your project/sources define:
102  _LIB if building a static library (_LIB is ignored if _CONSOLE is defined);
103  _USRDLL if building DLL-library;
104  not defined both _LIB and _USRDLL if building an application */
105 
106 /* Define AUTOINIT_FUNCS_DECLARE_STATIC_REG if you need macro declaration
107  for registering static initialisation functions even if you building DLL */
108 /* Define AUTOINIT_FUNCS_FORCE_STATIC_REG if you want to set main macro
109  _SET_INIT_AND_DEINIT_FUNCS to static version even if building a DLL */
110 
111 /* Stringify macros */
112 #define _INSTRMACRO(a) #a
113 #define _STRMACRO(a) _INSTRMACRO (a)
114 
115 #if ! defined(_USRDLL) || defined(AUTOINIT_FUNCS_DECLARE_STATIC_REG) \
116  || defined(AUTOINIT_FUNCS_FORCE_STATIC_REG)
117 
118 /* Use "C" linkage for variable to simplify variable decoration */
119 #ifdef __cplusplus
120 #define W32_INITVARDECL extern "C"
121 #else
122 #define W32_INITVARDECL extern
123 #endif
124 
125 /* How variable is decorated by compiler */
126 #if (defined(_WIN32) || defined(_WIN64)) \
127  && ! defined(_M_IX86) && ! defined(_X86_)
128 #if ! defined(_M_X64) && ! defined(_M_AMD64) && ! defined(_x86_64_) \
129  && ! defined(_M_ARM) && ! defined(_M_ARM64)
130 #pragma message(__FILE__ "(" _STRMACRO(__LINE__) ") : warning AIFW001 : " \
131  "Untested architecture, linker may fail with unresolved symbol")
132 #endif /* ! _M_X64 && ! _M_AMD64 && ! _x86_64_ && ! _M_ARM && ! _M_ARM64 */
133 #define W32_VARDECORPREFIX
134 #define W32_DECORVARNAME(v) v
135 #define W32_VARDECORPREFIXSTR ""
136 #elif defined(_WIN32) && (defined(_M_IX86) || defined(_X86_))
137 #define W32_VARDECORPREFIX _
138 #define W32_DECORVARNAME(v) _ ## v
139 #define W32_VARDECORPREFIXSTR "_"
140 #else
141 #error Do not know how to decorate symbols for this architecture
142 #endif
143 
144 /* Internal variable prefix (can be any) */
145 #define W32_INITHELPERVARNAME(f) _initHelperDummy_ ## f
146 #define W32_INITHELPERVARNAMEDECORSTR(f) \
147  W32_VARDECORPREFIXSTR _STRMACRO (W32_INITHELPERVARNAME (f))
148 
149 /* Declare section (segment), put variable pointing to init function to chosen segment,
150  force linker to always include variable to avoid omitting by optimiser */
151 /* Initialisation function must be declared as
152  void __cdecl FuncName(void) */
153 /* "extern" with initialisation value means that variable is declared AND defined. */
154 #define W32_VFPTR_IN_SEG(S,F) \
155  __pragma (section (S,long,read)) \
156  __pragma (comment (linker, "/INCLUDE:" W32_INITHELPERVARNAMEDECORSTR (F))) \
157  W32_INITVARDECL __declspec(allocate (S))void \
158  (__cdecl * W32_INITHELPERVARNAME (F))(void) = &F
159 
160 /* Sections (segments) for pointers to initialisers/deinitialisers */
161 
162 /* Semi-officially suggested section for early initialisers (called before
163  C++ objects initialisers), "void" return type */
164 #define W32_SEG_INIT_EARLY ".CRT$XCT"
165 /* Semi-officially suggested section for late initialisers (called after
166  C++ objects initialisers), "void" return type */
167 #define W32_SEG_INIT_LATE ".CRT$XCV"
168 
169 /* Unsafe sections (segments) for pointers to initialisers/deinitialisers */
170 
171 /* C++ lib initialisers, "void" return type (reserved by the system!) */
172 #define W32_SEG_INIT_CXX_LIB ".CRT$XCL"
173 /* C++ user initialisers, "void" return type (reserved by the system!) */
174 #define W32_SEG_INIT_CXX_USER ".CRT$XCU"
175 
176 
177 /* Declare section (segment), put variable pointing to init function to chosen segment,
178  force linker to always include variable to avoid omitting by optimiser */
179 /* Initialisation function must be declared as
180  int __cdecl FuncName(void) */
181 /* Startup process is aborted if initialiser returns non-zero */
182 /* "extern" with initialisation value means that variable is declared AND defined. */
183 #define W32_IFPTR_IN_SEG(S,F) \
184  __pragma (section (S,long,read)) \
185  __pragma (comment (linker, "/INCLUDE:" W32_INITHELPERVARNAMEDECORSTR (F))) \
186  W32_INITVARDECL __declspec(allocate (S))int \
187  (__cdecl * W32_INITHELPERVARNAME (F))(void) = &F
188 
189 /* Unsafe sections (segments) for pointers to initialisers with
190  "int" return type */
191 
192 /* C lib initialisers, "int" return type (reserved by the system!).
193  These initialisers are called before others. */
194 #define W32_SEG_INIT_C_LIB ".CRT$XIL"
195 /* C user initialisers, "int" return type (reserved by the system!).
196  These initialisers are called before others. */
197 #define W32_SEG_INIT_C_USER ".CRT$XIU"
198 
199 
200 /* Declare macro for different initialisers sections */
201 /* Macro can be used several times to register several initialisers */
202 /* Once function is registered as initialiser, it will be called automatically
203  during application startup */
204 #define W32_REG_INIT_EARLY(F) W32_VFPTR_IN_SEG (W32_SEG_INIT_EARLY,F)
205 #define W32_REG_INIT_LATE(F) W32_VFPTR_IN_SEG (W32_SEG_INIT_LATE,F)
206 
207 
208 /* Not recommended / unsafe */
209 /* "lib" initialisers are called before "user" initialisers */
210 /* "C" initialisers are called before "C++" initialisers */
211 #define W32_REG_INIT_C_USER(F) W32_FPTR_IN_SEG (W32_SEG_INIT_C_USER,F)
212 #define W32_REG_INIT_C_LIB(F) W32_FPTR_IN_SEG (W32_SEG_INIT_C_LIB,F)
213 #define W32_REG_INIT_CXX_USER(F) W32_FPTR_IN_SEG (W32_SEG_INIT_CXX_USER,F)
214 #define W32_REG_INIT_CXX_LIB(F) W32_FPTR_IN_SEG (W32_SEG_INIT_CXX_LIB,F)
215 
216 /* Choose main register macro based on language and program type */
217 /* Assuming that _LIB or _USRDLL is defined for static or DLL-library */
218 /* Macro can be used several times to register several initialisers */
219 /* Once function is registered as initialiser, it will be called automatically
220  during application startup */
221 /* Define AUTOINIT_FUNCS_FORCE_EARLY_INIT to force register as early
222  initialiser */
223 /* Define AUTOINIT_FUNCS_FORCE_LATE_INIT to force register as late
224  initialiser */
225 /* By default C++ static or DLL-library code and any C code and will be
226  registered as early initialiser, while C++ non-library code will be
227  registered as late initialiser */
228 #if (! defined(__cplusplus) || \
229  ((defined(_LIB) && ! defined(_CONSOLE)) || defined(_USRDLL)) || \
230  defined(AUTOINIT_FUNCS_FORCE_EARLY_INIT)) && \
231  ! defined(AUTOINIT_FUNCS_FORCE_LATE_INIT)
232 #define W32_REGISTER_INIT(F) W32_REG_INIT_EARLY(F)
233 #else
234 #define W32_REGISTER_INIT(F) W32_REG_INIT_LATE(F)
235 #endif
236 
237 #endif /* ! _USRDLL || ! AUTOINIT_FUNCS_DECLARE_STATIC_REG
238  || AUTOINIT_FUNCS_FORCE_STATIC_REG */
239 
240 
241 #if ! defined(_USRDLL) || defined(AUTOINIT_FUNCS_FORCE_STATIC_REG)
242 
243 #include <stdlib.h> /* required for atexit() */
244 
245 #define W32_SET_INIT_AND_DEINIT(FI,FD) \
246  void __cdecl _W32_init_helper_ ## FI (void); \
247  void __cdecl _W32_deinit_helper_ ## FD (void); \
248  void __cdecl _W32_init_helper_ ## FI (void) \
249  { (void) (FI) (); atexit (_W32_deinit_helper_ ## FD); } \
250  void __cdecl _W32_deinit_helper_ ## FD (void) \
251  { (void) (FD) (); } \
252  W32_REGISTER_INIT (_W32_init_helper_ ## FI)
253 #else /* _USRDLL */
254 
255 #ifndef WIN32_LEAN_AND_MEAN
256 #define WIN32_LEAN_AND_MEAN 1
257 #endif /* WIN32_LEAN_AND_MEAN */
258 
259 #include <Windows.h> /* Required for DllMain */
260 
261 /* If DllMain is already present in code, define AUTOINIT_FUNCS_CALL_USR_DLLMAIN
262  and rename DllMain to usr_DllMain */
263 #ifndef AUTOINIT_FUNCS_CALL_USR_DLLMAIN
264 #define W32_SET_INIT_AND_DEINIT(FI,FD) \
265  BOOL WINAPI DllMain (HINSTANCE hinst,DWORD reason,LPVOID unused); \
266  BOOL WINAPI DllMain (HINSTANCE hinst,DWORD reason,LPVOID unused) \
267  { (void) hinst; (void) unused; \
268  if (DLL_PROCESS_ATTACH==reason) {(void) (FI) ();} \
269  else if (DLL_PROCESS_DETACH==reason) {(void) (FD) ();} \
270  return TRUE; \
271  } struct _W32_dummy_strc_ ## FI {int i;}
272 #else /* AUTOINIT_FUNCS_CALL_USR_DLLMAIN */
273 #define W32_SET_INIT_AND_DEINIT(FI,FD) \
274  BOOL WINAPI usr_DllMain (HINSTANCE hinst,DWORD reason,LPVOID unused); \
275  BOOL WINAPI DllMain (HINSTANCE hinst,DWORD reason,LPVOID unused); \
276  BOOL WINAPI DllMain (HINSTANCE hinst,DWORD reason,LPVOID unused) \
277  { if (DLL_PROCESS_ATTACH==reason) {(void) (FI) ();} \
278  else if (DLL_PROCESS_DETACH==reason) {(void) (FD) ();} \
279  return usr_DllMain (hinst,reason,unused); \
280  } struct _W32_dummy_strc_ ## FI {int i;}
281 #endif /* AUTOINIT_FUNCS_CALL_USR_DLLMAIN */
282 #endif /* _USRDLL */
283 
284 #define _SET_INIT_AND_DEINIT_FUNCS(FI,FD) W32_SET_INIT_AND_DEINIT (FI,FD)
285 /* Indicate that automatic initialisers/deinitialisers are supported */
286 #define _AUTOINIT_FUNCS_ARE_SUPPORTED 1
287 
288 #else /* !__GNUC__ && !_MSC_FULL_VER */
289 
290 /* Define EMIT_ERROR_IF_AUTOINIT_FUNCS_ARE_NOT_SUPPORTED before inclusion of header to
291  abort compilation if automatic initialisers/deinitialisers are not supported */
292 #ifdef EMIT_ERROR_IF_AUTOINIT_FUNCS_ARE_NOT_SUPPORTED
293 #error \
294  Compiler/platform does not support automatic calls of user-defined initializer and deinitializer
295 #endif /* EMIT_ERROR_IF_AUTOINIT_FUNCS_ARE_NOT_SUPPORTED */
296 
297 /* Do nothing */
298 #define _SET_INIT_AND_DEINIT_FUNCS(FI,FD)
299 /* Indicate that automatic initialisers/deinitialisers are not supported */
300 #define _AUTOINIT_FUNCS_ARE_NOT_SUPPORTED 1
301 
302 #endif /* !__GNUC__ && !_MSC_FULL_VER */
303 #endif /* !AUTOINIT_FUNCS_INCLUDED */