[wxWidgets.git] / include / wx / html / forcelink.h

/////////////////////////////////////////////////////////////////////////////
// Name:        forcelink.h
// Purpose:     see bellow
// Author:      Vaclav Slavik
// Copyright:   (c) 1999 Vaclav Slavik
// Licence:     wxWindows Licence
/////////////////////////////////////////////////////////////////////////////

/*

DESCRPITON:

mod_*.cpp files contain handlers for tags. These files are modules - they contain
one wxTagModule class and it's OnInit() method is called from wxApp's init method.
The module is called even if you only link it into the executable, so everything
seems wonderful.

The problem is that we have these modules in LIBRARY and mod_*.cpp files contain
no method nor class which is known out of the module. So the linker won't
link these .o/.obj files into executable because it detected that it is not used
by the program.

To workaround this I introduced set of macros FORCE_LINK_ME and FORCE_LINK. These
macros are generic and are not limited to mod_*.cpp files. You may find them quite
useful somewhere else...

How to use them:
let's suppose you want to always link file foo.cpp and that you have module
always.cpp that is certainly always linked (e.g. the one with main() function
or htmlwin.cpp in wxHtml library).

Place FORCE_LINK_ME(foo) somewhere in foo.cpp and FORCE_LINK(foo) somewhere
in always.cpp
See mod_*.cpp and htmlwin.cpp for example :-)

*/


#ifndef __FORCELINK_H__
#define __FORCELINK_H__


// This must be part of the module you want to force:
#define FORCE_LINK_ME(module_name)                                    \
                int _link_dummy_func_##module_name ()                 \
                {                                                     \
                    return 1;                                         \
                }


// And this must be somewhere where it certainly will be linked:
#define FORCE_LINK(module_name)                                       \
                extern int _link_dummy_func_##module_name ();         \
                static int _link_dummy_var_##module_name =            \
                               _link_dummy_func_##module_name ();


#endif // __FORCELINK_H__
Commit	Line	Data
5526e819 VS	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__