| | 1 | ///////////////////////////////////////////////////////////////////////////// |
| | 2 | // Name: forcelink.h |
| | 3 | // Purpose: see bellow |
| | 4 | // Author: Vaclav Slavik |
| | 5 | // Copyright: (c) 1999 Vaclav Slavik |
| | 6 | // Licence: wxWindows Licence |
| | 7 | ///////////////////////////////////////////////////////////////////////////// |
| | 8 | |
| | 9 | /* |
| | 10 | |
| | 11 | DESCRPITON: |
| | 12 | |
| | 13 | mod_*.cpp files contain handlers for tags. These files are modules - they contain |
| | 14 | one wxTagModule class and it's OnInit() method is called from wxApp's init method. |
| | 15 | The module is called even if you only link it into the executable, so everything |
| | 16 | seems wonderful. |
| | 17 | |
| | 18 | The problem is that we have these modules in LIBRARY and mod_*.cpp files contain |
| | 19 | no method nor class which is known out of the module. So the linker won't |
| | 20 | link these .o/.obj files into executable because it detected that it is not used |
| | 21 | by the program. |
| | 22 | |
| | 23 | To workaround this I introduced set of macros FORCE_LINK_ME and FORCE_LINK. These |
| | 24 | macros are generic and are not limited to mod_*.cpp files. You may find them quite |
| | 25 | useful somewhere else... |
| | 26 | |
| | 27 | How to use them: |
| | 28 | let's suppose you want to always link file foo.cpp and that you have module |
| | 29 | always.cpp that is certainly always linked (e.g. the one with main() function |
| | 30 | or htmlwin.cpp in wxHtml library). |
| | 31 | |
| | 32 | Place FORCE_LINK_ME(foo) somewhere in foo.cpp and FORCE_LINK(foo) somewhere |
| | 33 | in always.cpp |
| | 34 | See mod_*.cpp and htmlwin.cpp for example :-) |
| | 35 | |
| | 36 | */ |
| | 37 | |
| | 38 | |
| | 39 | #ifndef __FORCELINK_H__ |
| | 40 | #define __FORCELINK_H__ |
| | 41 | |
| | 42 | |
| | 43 | |
| | 44 | // This must be part of the module you want to force: |
| | 45 | #define FORCE_LINK_ME(module_name) \ |
| | 46 | int _link_dummy_func_##module_name () \ |
| | 47 | { \ |
| | 48 | return 1; \ |
| | 49 | } |
| | 50 | |
| | 51 | |
| | 52 | // And this must be somewhere where it certainly will be linked: |
| | 53 | #define FORCE_LINK(module_name) \ |
| | 54 | extern int _link_dummy_func_##module_name (); \ |
| | 55 | static int _link_dummy_var_##module_name = \ |
| | 56 | _link_dummy_func_##module_name (); |
| | 57 | |
| | 58 | |
| | 59 | #endif // __FORCELINK_H__ |
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