2011-05-23  Nathan Sidwell  <nathan@codesourcery.com>

	gcc/
	* config/arm/unwind-arm.c (enum __cxa_type_match_result): New.
	(cxa_type_match): Correct declaration.
	(__gnu_unwind_pr_common): Reconstruct
	additional indirection when __cxa_type_match returns
	succeeded_with_ptr_to_base.

	libstdc++/
	* libsupc++/eh_arm.c (__cxa_type_match): Construct address of
	thrown object here.  Return succeded_with_ptr_to_base for all
	pointer cases.

Index: libstdc++-v3/libsupc++/eh_arm.cc
===================================================================
--- libstdc++-v3/libsupc++/eh_arm.cc	(revision 173851)
+++ libstdc++-v3/libsupc++/eh_arm.cc	(working copy)
@@ -30,10 +30,11 @@
 using namespace __cxxabiv1;
 
 
-// Given the thrown type THROW_TYPE, pointer to a variable containing a
-// pointer to the exception object THROWN_PTR_P and a type CATCH_TYPE to
-// compare against, return whether or not there is a match and if so,
-// update *THROWN_PTR_P.
+// Given the thrown type THROW_TYPE, exception object UE_HEADER and a
+// type CATCH_TYPE to compare against, return whether or not there is
+// a match and if so, update *THROWN_PTR_P to point to either the
+// type-matched object, or in the case of a pointer type, the object
+// pointed to by the pointer.
 
 extern "C" __cxa_type_match_result
 __cxa_type_match(_Unwind_Exception* ue_header,
@@ -41,51 +42,51 @@ __cxa_type_match(_Unwind_Exception* ue_h
 		 bool is_reference __attribute__((__unused__)),
 		 void** thrown_ptr_p)
 {
-  bool forced_unwind = __is_gxx_forced_unwind_class(ue_header->exception_class);
-  bool foreign_exception = !forced_unwind && !__is_gxx_exception_class(ue_header->exception_class);
-  bool dependent_exception =
-    __is_dependent_exception(ue_header->exception_class);
+  bool forced_unwind
+    = __is_gxx_forced_unwind_class(ue_header->exception_class);
+  bool foreign_exception
+    = !forced_unwind && !__is_gxx_exception_class(ue_header->exception_class);
+  bool dependent_exception
+    = __is_dependent_exception(ue_header->exception_class);
   __cxa_exception* xh = __get_exception_header_from_ue(ue_header);
   __cxa_dependent_exception *dx = __get_dependent_exception_from_ue(ue_header);
   const std::type_info* throw_type;
+  void *thrown_ptr = 0;
 
   if (forced_unwind)
     throw_type = &typeid(abi::__forced_unwind);
   else if (foreign_exception)
     throw_type = &typeid(abi::__foreign_exception);
-  else if (dependent_exception)
-    throw_type = __get_exception_header_from_obj
-      (dx->primaryException)->exceptionType;
   else
-    throw_type = xh->exceptionType;
-
-  void* thrown_ptr = *thrown_ptr_p;
+    {
+      if (dependent_exception)
+	xh = __get_exception_header_from_obj (dx->primaryException);
+      throw_type = xh->exceptionType;
+      // We used to require the caller set the target of thrown_ptr_p,
+      // but that's incorrect -- the EHABI makes no such requirement
+      // -- and not all callers will set it.  Fortunately callers that
+      // do initialize will always pass us the value we calculate
+      // here, so there's no backwards compatibility problem.
+      thrown_ptr = __get_object_from_ue (ue_header);
+    }
+  
+  __cxa_type_match_result result = ctm_succeeded;
 
   // Pointer types need to adjust the actual pointer, not
   // the pointer to pointer that is the exception object.
   // This also has the effect of passing pointer types
   // "by value" through the __cxa_begin_catch return value.
   if (throw_type->__is_pointer_p())
-    thrown_ptr = *(void**) thrown_ptr;
+    {
+      thrown_ptr = *(void**) thrown_ptr;
+      // We need to indicate the indirection to our caller.
+      result = ctm_succeeded_with_ptr_to_base;
+    }
 
   if (catch_type->__do_catch(throw_type, &thrown_ptr, 1))
     {
       *thrown_ptr_p = thrown_ptr;
-
-      if (typeid(*catch_type) == typeid (typeid(void*)))
-	{
-	  const __pointer_type_info *catch_pointer_type =
-	    static_cast<const __pointer_type_info *> (catch_type);
-	  const __pointer_type_info *throw_pointer_type =
-	    static_cast<const __pointer_type_info *> (throw_type);
-
-	  if (typeid (*catch_pointer_type->__pointee) != typeid (void)
-	      && (*catch_pointer_type->__pointee != 
-		  *throw_pointer_type->__pointee))
-	    return ctm_succeeded_with_ptr_to_base;
-	}
-
-      return ctm_succeeded;
+      return result;
     }
 
   return ctm_failed;
Index: gcc/config/arm/unwind-arm.c
===================================================================
--- gcc/config/arm/unwind-arm.c	(revision 173851)
+++ gcc/config/arm/unwind-arm.c	(working copy)
@@ -32,13 +32,18 @@ extern void abort (void);
 typedef unsigned char bool;
 
 typedef struct _ZSt9type_info type_info; /* This names C++ type_info type */
+enum __cxa_type_match_result
+  {
+    ctm_failed = 0,
+    ctm_succeeded = 1,
+    ctm_succeeded_with_ptr_to_base = 2
+  };
 
 void __attribute__((weak)) __cxa_call_unexpected(_Unwind_Control_Block *ucbp);
 bool __attribute__((weak)) __cxa_begin_cleanup(_Unwind_Control_Block *ucbp);
-bool __attribute__((weak)) __cxa_type_match(_Unwind_Control_Block *ucbp,
-					    const type_info *rttip,
-					    bool is_reference,
-					    void **matched_object);
+enum __cxa_type_match_result __attribute__((weak)) __cxa_type_match
+  (_Unwind_Control_Block *ucbp, const type_info *rttip,
+   bool is_reference, void **matched_object);
 
 _Unwind_Ptr __attribute__((weak))
 __gnu_Unwind_Find_exidx (_Unwind_Ptr, int *);
@@ -1107,6 +1112,7 @@ __gnu_unwind_pr_common (_Unwind_State st
 		      _uw rtti;
 		      bool is_reference = (data[0] & uint32_highbit) != 0;
 		      void *matched;
+		      enum __cxa_type_match_result match_type;
 
 		      /* Check for no-throw areas.  */
 		      if (data[1] == (_uw) -2)
@@ -1118,17 +1124,31 @@ __gnu_unwind_pr_common (_Unwind_State st
 			{
 			  /* Match a catch specification.  */
 			  rtti = _Unwind_decode_target2 ((_uw) &data[1]);
-			  if (!__cxa_type_match (ucbp, (type_info *) rtti,
-						 is_reference,
-						 &matched))
-			    matched = (void *)0;
+			  match_type = __cxa_type_match (ucbp,
+							 (type_info *) rtti,
+							 is_reference,
+							 &matched);
 			}
+		      else
+			match_type = ctm_succeeded;
 
-		      if (matched)
+		      if (match_type)
 			{
 			  ucbp->barrier_cache.sp =
 			    _Unwind_GetGR (context, R_SP);
-			  ucbp->barrier_cache.bitpattern[0] = (_uw) matched;
+			  // ctm_succeeded_with_ptr_to_base really
+			  // means _c_t_m indirected the pointer
+			  // object.  We have to reconstruct the
+			  // additional pointer layer by using a temporary.
+			  if (match_type == ctm_succeeded_with_ptr_to_base)
+			    {
+			      ucbp->barrier_cache.bitpattern[2]
+				= (_uw) matched;
+			      ucbp->barrier_cache.bitpattern[0]
+				= (_uw) &ucbp->barrier_cache.bitpattern[2];
+			    }
+			  else
+			    ucbp->barrier_cache.bitpattern[0] = (_uw) matched;
 			  ucbp->barrier_cache.bitpattern[1] = (_uw) data;
 			  return _URC_HANDLER_FOUND;
 			}
