* dcrt0.cc (cygwin_atexit): Change preceeding comment to reflect

	API version numbers.
	* external.cc (cygwin_internal): disable setting cxx_malloc on 64 bit.
	Add CW_FIXED_ATEXIT case.
	* include/cygwin/version.h (CYGWIN_VERSION_API_MINOR): Bump.
	* include/sys/cygwin.h (cygwin_getinfo_types): Add CW_FIXED_ATEXIT.
	* lib/atexit.c (atexit): Test running Cygwin version by checking
	return value of cygwin_internal (CW_FIXED_ATEXIT).

1 files changed, 18 insertions, 3 deletions

diff --git a/winsup/cygwin/lib/atexit.c b/winsup/cygwin/lib/atexit.c
index af82d1de7..a2dec6267 100644
--- a/winsup/cygwin/lib/atexit.c
+++ b/winsup/cygwin/lib/atexit.c
@@ -9,11 +9,13 @@ Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
 details. */
 
 #include <stddef.h>
+#include <sys/cygwin.h>
 #include <windows.h>
 
 /* Statically linked replacement for the former cygwin_atexit.  We need
    the function here to be able to access the correct __dso_handle of the
    caller's DSO. */
+
 int
 atexit (void (*fn) (void))
 {
@@ -21,6 +23,7 @@ atexit (void (*fn) (void))
   extern void *__dso_handle;
   extern void *__ImageBase;
 
+  void *fixed_dso_handle = &__dso_handle;
   /* Check for being called from inside the executable.  If so, use NULL
      as __dso_handle.  This allows to link executables with GCC versions
      not providing __dso_handle in crtbegin{S}.o.  In this case our own
@@ -28,7 +31,19 @@ atexit (void (*fn) (void))
      __dso_handle always points to &__ImageBase, while the __dso_handle
      for executables provided by crtbegin.o usually points to NULL.
      That's what we remodel here. */
-  return __cxa_atexit ((void (*)(void*))fn, NULL,
-		       &__ImageBase == (void **) GetModuleHandleW (NULL)
-		       ? NULL : &__dso_handle);
+  if (&__ImageBase == (void **) GetModuleHandleW (NULL))
+    fixed_dso_handle = NULL;
+  /* With recent Cygwin versions starting with API version 0.280 we call
+     __cxa_atexit (which is actually the cygwin__cxa_atexit wrapper in
+     dcrt0.cc) with the address of __dso_handle since that's how g++ generates
+     calls to __cxa_atexit as well.  However, when running an application
+     built with this atexit under an older Cygwin version, the __cxa_atexit
+     entry point is the one from newlib, which expects the *value* of
+     __dso_handle.  So, check for the Cygwin version we're running under.
+     Older version prior to 0.280 don't know CW_FIXED_ATEXIT and return -1.
+     0.280 and later return 0. */
+  else if (cygwin_internal (CW_FIXED_ATEXIT) != 0)
+    fixed_dso_handle = __dso_handle;
+
+  return __cxa_atexit ((void (*)(void*))fn, NULL, fixed_dso_handle);
 }