C++ify, add new get_cxx_exception function to convert from generic llvm_exceptions to llvm_cxx_exception's

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@8156 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 3 deletions

diff --git a/runtime/GCCLibraries/libexception/C++-Exception.h b/runtime/GCCLibraries/libexception/C++-Exception.h
index 9c5447b88a..6ff384e84d 100644
--- a/runtime/GCCLibraries/libexception/C++-Exception.h
+++ b/runtime/GCCLibraries/libexception/C++-Exception.h
@@ -10,8 +10,9 @@
 
 #include "exception.h"
 #include <typeinfo>
+#include <cassert>
 
-typedef struct llvm_cxx_exception {
+struct llvm_cxx_exception {
   /* TypeInfo - A pointer to the C++ std::type_info object for this exception
    * class.  This is required because the class may not be polymorphic.
    */
@@ -42,9 +43,12 @@ typedef struct llvm_cxx_exception {
    * this structure without breaking binary compatibility.
    */
   llvm_exception BaseException;
-} llvm_cxx_exception;
-
+};
 
+inline llvm_cxx_exception *get_cxx_exception(llvm_exception *E) {
+  assert(E->ExceptionType == CXXException && "Not a C++ exception?");
+  return (llvm_cxx_exception*)(E+1)-1;
+}
 
 extern "C" {
   void *__llvm_cxxeh_allocate_exception(unsigned NumBytes);