[patch PR libstdc++/51135]: Fix [4.7 Regression] SIGSEGV during exception cleanup on win32

[Kai Tietz]

Hi,

this bug was caused by change of default-calling-convention of
__thiscall for class-member-functions on 32-bit IA windows target.
Issue is that that destructor pointer used default __cdecl
calling-convention instead.  This patch fix that.
As currently trunk is still broken for all SjLj targets (this clobber
patch really clobbered things ...) and so for 32-bit Windows native
too, it is necessary to disable - until this bug is fixed in compiler
(PR/51117)- for the unwind-sjlj.c file in libgcc the option
-fexceptions.

ChangeLog

2011-12-08  Kai Tietz  <kti...@redhat.com>

        PR libstdc++/511135
        * libsupc++/cxxabi.h (_GLIBCXX_DESTRUCTOR_CALLCONVENTION): New
        macro.
        (__cxa_throw): Use it for destructor-argument.
        * eh_throw.cc (__cxa_throw): Likewise.
        * unwind-cxx.h (__cxa_exception): Use for member
        exceptionDestructor the _GLIBCXX_DESTRUCTOR_CALLCONVENTION macro.

Patch tested for i686-w64-mingw32, i686-pc-cygwin, x86_64-w64-mingw32,
and x86_64-unknown-linux-gnu.  Ok for apply?

Regards,
Kai

Index: gcc/libstdc++-v3/libsupc++/cxxabi.h
===================================================================
--- gcc.orig/libstdc++-v3/libsupc++/cxxabi.h
+++ gcc/libstdc++-v3/libsupc++/cxxabi.h
@@ -51,6 +51,16 @@
 #include <bits/cxxabi_tweaks.h>
 #include <bits/cxxabi_forced.h>

+// On 32-bit IA native windows target is the used calling-convention
+// for class-member-functions of kind __thiscall.  As destructor is
+// also of kind class-member-function, we need to specify for this
+// target proper calling-convention on destructor-function-pointer.
+#if defined (__MINGW32__) && defined (__i386__)
+#define _GLIBCXX_DESTRUCTOR_CALLCONVENTION __thiscall
+#else
+#define _GLIBCXX_DESTRUCTOR_CALLCONVENTION
+#endif
+
 #ifdef __cplusplus
 namespace __cxxabiv1
 {
@@ -596,7 +606,8 @@ namespace __cxxabiv1

   // Throw the exception.
   void
-  __cxa_throw(void*, std::type_info*, void (*) (void *))
+  __cxa_throw(void*, std::type_info*,
+             void (_GLIBCXX_DESTRUCTOR_CALLCONVENTION *) (void *))
   __attribute__((__noreturn__));

   // Used to implement exception handlers.
Index: gcc/libstdc++-v3/libsupc++/eh_throw.cc
===================================================================
--- gcc.orig/libstdc++-v3/libsupc++/eh_throw.cc
+++ gcc/libstdc++-v3/libsupc++/eh_throw.cc
@@ -59,7 +59,8 @@ __gxx_exception_cleanup (_Unwind_Reason_

 extern "C" void
 __cxxabiv1::__cxa_throw (void *obj, std::type_info *tinfo,
-                        void (*dest) (void *))
+                        void (_GLIBCXX_DESTRUCTOR_CALLCONVENTION *dest)
+                             (void *))
 {
   // Definitely a primary.
   __cxa_refcounted_exception *header
Index: gcc/libstdc++-v3/libsupc++/unwind-cxx.h
===================================================================
--- gcc.orig/libstdc++-v3/libsupc++/unwind-cxx.h
+++ gcc/libstdc++-v3/libsupc++/unwind-cxx.h
@@ -51,7 +51,7 @@ struct __cxa_exception
 {
   // Manage the exception object itself.
   std::type_info *exceptionType;
-  void (*exceptionDestructor)(void *);
+  void (_GLIBCXX_DESTRUCTOR_CALLCONVENTION *exceptionDestructor)(void *);

   // The C++ standard has entertaining rules wrt calling set_terminate
   // and set_unexpected in the middle of the exception cleanup process.