48 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			48 lines
		
	
	
		
			1.9 KiB
		
	
	
	
		
			C
		
	
	
	
/* atexit.c: atexit entry point
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This file is part of Cygwin.
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This software is a copyrighted work licensed under the terms of the
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Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
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details. */
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#include <stddef.h>
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#include <sys/cygwin.h>
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#include <windows.h>
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/* Statically linked replacement for the former cygwin_atexit.  We need
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   the function here to be able to access the correct __dso_handle of the
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   caller's DSO. */
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int
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atexit (void (*fn) (void))
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{
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  extern int __cxa_atexit(void (*)(void*), void*, void*);
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  extern void *__dso_handle;
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  extern void *__ImageBase;
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  void *fixed_dso_handle = &__dso_handle;
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  /* Check for being called from inside the executable.  If so, use NULL
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     as __dso_handle.  This allows to link executables with GCC versions
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     not providing __dso_handle in crtbegin{S}.o.  In this case our own
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     __dso_handle defined in lib/dso_handle.c is used.  However, our
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     __dso_handle always points to &__ImageBase, while the __dso_handle
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     for executables provided by crtbegin.o usually points to NULL.
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     That's what we remodel here. */
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  if (&__ImageBase == (void **) GetModuleHandleW (NULL))
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    fixed_dso_handle = NULL;
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  /* With recent Cygwin versions starting with API version 0.280 we call
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     __cxa_atexit (which is actually the cygwin__cxa_atexit wrapper in
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     dcrt0.cc) with the address of __dso_handle since that's how g++ generates
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     calls to __cxa_atexit as well.  However, when running an application
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     built with this atexit under an older Cygwin version, the __cxa_atexit
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     entry point is the one from newlib, which expects the *value* of
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     __dso_handle.  So, check for the Cygwin version we're running under.
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     Older version prior to 0.280 don't know CW_FIXED_ATEXIT and return -1.
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     0.280 and later return 0. */
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  else if (cygwin_internal (CW_FIXED_ATEXIT) != 0)
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    fixed_dso_handle = __dso_handle;
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  return __cxa_atexit ((void (*)(void*))fn, NULL, fixed_dso_handle);
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}
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