Add atexit support for dlls.

	* crt1.c (atexit): Force thunk to _imp__atexit.
	(_onexit): Force thunk to _imp___onexit.
	* dllcrt1.c (DllMainCRTStartup): Initialise private atexit
	table on DLL_PROCESS_ATTACH, clean it up on DLL_PROCESS_DETACH.
	(__dll_exit): New function to run atexit-registered functions
	 and flush output buffers on DLL_PROCESS_DETACH or failed
	DLL_PROCESS_ATTACH.
	(atexit): Force use of private atexit table via _dllonexit,
	(_onexit): New function. Force use of private atexit table via
	_dllonexit,
	* mscvrt.def (atexit, _onexit): Add DATA keyword so that only
	_imp_<_symbol> is visible in import lib.
	* mscvrt20.def: Likewise.
	* mscvrt40.def: Likewise.
	* crtdll.def: Likewise.

7 files changed, 240 insertions, 8 deletions

diff --git a/winsup/mingw/ChangeLog b/winsup/mingw/ChangeLog
index 19768b45b8b..f82b2b01526 100644
--- a/winsup/mingw/ChangeLog
+++ b/winsup/mingw/ChangeLog
@@ -1,5 +1,24 @@
 2002-04-26  Danny Smith  <dannysmith@users.sourceforge.net>
 
+	Add atexit support for dlls.
+	* crt1.c (atexit): Force thunk to _imp__atexit.
+	(_onexit): Force thunk to _imp___onexit.
+	* dllcrt1.c (DllMainCRTStartup): Initialise private atexit
+	table on DLL_PROCESS_ATTACH, clean it up on DLL_PROCESS_DETACH.
+	(__dll_exit): New function to run atexit-registered functions
+	 and flush output buffers on DLL_PROCESS_DETACH or failed
+	DLL_PROCESS_ATTACH. 
+	(atexit): Force use of private atexit table via _dllonexit,
+	(_onexit): New function. Force use of private atexit table via
+	_dllonexit,
+	* mscvrt.def (atexit, _onexit): Add DATA keyword so that only 
+	_imp_<_symbol> is visible in import lib.
+	* mscvrt20.def: Likewise.
+	* mscvrt40.def: Likewise.
+	* crtdll.def: Likewise.
+
+2002-04-26  Danny Smith  <dannysmith@users.sourceforge.net>
+
 	* include/fenv.h: Change header guard macro to _FENV_H_.
 	(fenv_t, fexcept_t): Move into block protected by
 	#ifndef RC_INVOKED.
diff --git a/winsup/mingw/crt1.c b/winsup/mingw/crt1.c
index f91f1da28f1..a11c2fb039f 100644
--- a/winsup/mingw/crt1.c
+++ b/winsup/mingw/crt1.c
@@ -232,3 +232,20 @@ WinMainCRTStartup ()
   __mingw_CRTStartup ();
 }
 
+/*
+ *  We force use of library version of atexit, which is only
+ *  visible in import lib as _imp__atexit
+ */
+extern int (*_imp__atexit)(void (*)(void));
+int atexit (void (* pfn )(void) )
+{
+  return ( (*_imp__atexit)(pfn));
+}
+
+/* Likewise for non-ANSI _onexit */
+extern _onexit_t (*_imp___onexit)(_onexit_t);
+_onexit_t
+_onexit (_onexit_t pfn )
+{
+  return (*_imp___onexit)(pfn);
+}
diff --git a/winsup/mingw/crtdll.def b/winsup/mingw/crtdll.def
index 694547471e6..6f924fb7b34 100644
--- a/winsup/mingw/crtdll.def
+++ b/winsup/mingw/crtdll.def
@@ -414,7 +414,7 @@ _mkdir
 _mktemp
 _msize
 _nextafter
-_onexit
+_onexit DATA
 _open
 _open_osfhandle
 _osmajor_dll DATA
@@ -520,7 +520,7 @@ asctime
 asin
 atan
 atan2
-atexit
+atexit DATA
 atof
 atoi
 atol
diff --git a/winsup/mingw/dllcrt1.c b/winsup/mingw/dllcrt1.c
new file mode 100644
index 00000000000..fe351eb1090
--- /dev/null
+++ b/winsup/mingw/dllcrt1.c
@@ -0,0 +1,196 @@
+/*
+ * dllcrt1.c
+ *
+ * Initialization code for DLLs.
+ *
+ * This file is part of the Mingw32 package.
+ *
+ * Contributors:
+ *  Created by Colin Peters <colin@bird.fu.is.saga-u.ac.jp>
+ *  DLL support adapted from Gunther Ebert <gunther.ebert@ixos-leipzig.de>
+ *  Maintained by Mumit Khan <khan@xraylith.wisc.EDU>
+ *
+ *  THIS SOFTWARE IS NOT COPYRIGHTED
+ *
+ *  This source code is offered for use in the public domain. You may
+ *  use, modify or distribute it freely.
+ *
+ *  This code is distributed in the hope that it will be useful but
+ *  WITHOUT ANY WARRANTY. ALL WARRENTIES, EXPRESS OR IMPLIED ARE HEREBY
+ *  DISCLAMED. This includes but is not limited to warrenties of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * $Revision$
+ * $Author$
+ * $Date$
+ * 
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <io.h>
+#include <process.h>
+#include <errno.h>
+#include <windows.h>
+
+/* Unlike normal crt1, I don't initialize the FPU, because the process
+ * should have done that already. I also don't set the file handle modes,
+ * because that would be rude. */
+
+#ifdef	__GNUC__
+extern void __main ();
+extern void __do_global_dtors ();
+#endif
+
+typedef void (* p_atexit_fn )(void);
+static p_atexit_fn* first_atexit;
+static p_atexit_fn* next_atexit;
+
+static void
+__dll_exit (void);
+
+/* This  is based on the function in the Wine project's exit.c */
+p_atexit_fn __dllonexit (p_atexit_fn, p_atexit_fn**, p_atexit_fn**);
+
+
+extern BOOL WINAPI DllMain (HANDLE, DWORD, LPVOID);
+
+
+BOOL WINAPI
+DllMainCRTStartup (HANDLE hDll, DWORD dwReason, LPVOID lpReserved)
+{
+  BOOL bRet;
+
+  if (dwReason == DLL_PROCESS_ATTACH)
+    {
+      /* Initialize private atexit table for this dll.
+	 32 is min size required by ANSI */
+
+      first_atexit = (p_atexit_fn*) malloc (32 * sizeof (p_atexit_fn));
+      if (first_atexit == NULL ) /* can't allocate memory */
+	{
+	  errno=ENOMEM;
+	  return FALSE;
+	}
+      *first_atexit =  NULL;
+      next_atexit = first_atexit;
+
+#ifdef DEBUG
+        printf ("%s: DLL_PROCESS_ATTACH (%d)\n", __FUNCTION__);
+#endif
+
+                
+#ifdef	__GNUC__
+      /* From libgcc.a, __main calls global class constructors,
+	 __do_global_ctors, which registers __do_global_dtors
+	 as the first entry of the private atexit table we
+	 have just initialised  */
+      __main ();
+      	
+#endif
+   }
+
+  /*
+   * Call the user-supplied DllMain subroutine.
+   * This has to come after initialization of atexit table and
+   * registration of global constructors.
+   * NOTE: DllMain is optional, so libmingw32.a includes a stub
+   *       which will be used if the user does not supply one.
+   */
+
+  bRet = DllMain (hDll, dwReason, lpReserved);
+  /* Handle case where DllMain returns FALSE on attachment attempt.  */ 
+
+  if ( (dwReason == DLL_PROCESS_ATTACH) && !bRet)
+    {
+#ifdef DEBUG
+      printf ("%s: DLL_PROCESS_ATTACH failed, cleaning up\n", __FUNCTION__);
+#endif
+
+      __dll_exit ();     /* Cleanup now. This will set first_atexit to NULL so we
+			    know we've cleaned up	*/
+    }
+
+  if (dwReason == DLL_PROCESS_DETACH)
+    {
+#ifdef DEBUG
+      printf ("%s: DLL_PROCESS_DETACH (%d)\n", __FUNCTION__);
+#endif
+      /* If not attached, return FALSE. Cleanup already done above
+	 if failed attachment attempt. */
+      if  (! first_atexit )
+        bRet = FALSE;
+      else
+	/*
+	 * We used to call __do_global_dtors () here. This is
+	 * no longer necessary since  __do_global_dtors is now
+	 * registered at start (last out) of private atexit table.
+	 */
+	__dll_exit ();
+    }
+  return bRet;
+}
+
+static
+void
+__dll_exit(void)
+/* Run LIFO terminators registered in private atexit table */
+{
+  if ( first_atexit )
+    {
+      p_atexit_fn* __last = next_atexit - 1;
+      while ( __last >= first_atexit )
+	{	
+          if ( *__last != NULL )
+	    {
+#ifdef DEBUG
+	      printf ("%s: Calling exit function  0x%x from 0x%x\n",
+		      __FUNCTION__, (unsigned)(*__last),(unsigned)__last);
+#endif
+              (**__last) ();
+	    }
+	  __last--;
+	}
+      free ( first_atexit ) ;
+      first_atexit = NULL ;
+    }
+    /*
+       Make sure output buffers opened by DllMain or 
+       atexit-registered functions are flushed before detaching,
+       otherwise we can have problems with redirected output.
+     */
+    fflush (NULL);
+}
+
+/*
+ * The atexit exported from msvcrt.dll causes problems in DLLs.
+ * Here, we override the exported version of atexit with one that passes the
+ * private table initialised in DllMainCRTStartup to __dllonexit.
+ * That means we have to hide the mscvrt.dll atexit because the
+ * atexit defined here gets __dllonexit from the same lib. 
+ */
+
+int
+atexit (p_atexit_fn pfn )
+{
+#ifdef DEBUG
+  printf ("%s: registering exit function  0x%x at 0x%x\n",
+	  __FUNCTION__, (unsigned)pfn, (unsigned)next_atexit);
+#endif
+  return (__dllonexit (pfn,  &first_atexit, &next_atexit)
+	  == NULL ? -1  : 0 );
+}
+
+/*
+ * Likewise for non-ANSI function _onexit that may be called by
+ * code in the dll. 
+ */
+
+_onexit_t
+_onexit (_onexit_t pfn )
+{
+#ifdef DEBUG
+  printf ("%s: registering exit function  0x%x at 0x%x\n",
+	  __FUNCTION__, (unsigned)pfn, (unsigned)next_atexit);
+#endif
+  return ((_onexit_t) __dllonexit ((p_atexit_fn)pfn,  &first_atexit, &next_atexit));
+}
diff --git a/winsup/mingw/msvcrt.def b/winsup/mingw/msvcrt.def
index 8d3e1a8cc21..0b85e9e1cb1 100644
--- a/winsup/mingw/msvcrt.def
+++ b/winsup/mingw/msvcrt.def
@@ -365,7 +365,7 @@ _mkdir
 _mktemp
 _msize
 _nextafter
-_onexit
+_onexit DATA
 _open
 _open_osfhandle
 _osver DATA
@@ -546,7 +546,7 @@ asctime
 asin
 atan
 atan2
-atexit
+atexit DATA
 atof
 atoi
 atol
diff --git a/winsup/mingw/msvcrt20.def b/winsup/mingw/msvcrt20.def
index 77ff49510cc..9ceb0750e7b 100644
--- a/winsup/mingw/msvcrt20.def
+++ b/winsup/mingw/msvcrt20.def
@@ -329,7 +329,7 @@ _msize
 _mtlock
 _mtunlock
 _nextafter
-_onexit
+_onexit DATA
 _open
 _open_osfhandle
 _osver
@@ -528,7 +528,7 @@ asctime
 asin
 atan
 atan2
-atexit
+atexit DATA
 atof
 atoi
 atol
diff --git a/winsup/mingw/msvcrt40.def b/winsup/mingw/msvcrt40.def
index 936aff962ee..e4b09f999eb 100644
--- a/winsup/mingw/msvcrt40.def
+++ b/winsup/mingw/msvcrt40.def
@@ -312,7 +312,7 @@ _msize
 _mtlock
 _mtunlock
 _nextafter
-_onexit
+_onexit DATA
 _open
 _open_osfhandle
 _osver
@@ -485,7 +485,7 @@ asctime
 asin
 atan
 atan2
-atexit
+atexit DATA
 atof
 atoi
 atol