cxa_vec_dtor question

[Kenny Simpson <Kenny dot Simpson at gs dot com>]

Hi,
  While browsing through gcc sources I came across the __cxa_vec_dtor
function in libstdc++-v3/libsupc++/vec.cc.  It appeared to be an
implementation of the underlying delete [] function, however...

  This function uses std::uncaught_exception() to test if a stack unwind
is currently underway.  This is incorrect.
> bool unwinding = std::uncaught_exception ();
(see http://www.peerdirect.com/Resources/gotw047a.html)

  While trying to create a test case to expose the potential bug, I found
that this function is not called from the resulting program.  Is this function
currently being used?  My current snapshot does the right thing for my test
case (2001211), but if cxa_vec_dtor were used, the following test might fail.

  This program should terminate normally, but if __cxa_vec_dtor were used, it
may call std::terminate instead.

-Kenny
(not speaking for my employer)

test.cc
#include <exception>

struct Time_Bomb
{
  Time_Bomb() { ++count;}
  ~Time_Bomb()
  {
    --count;
    if (count == 3) throw false; // kaboom!
  }

  static int count;
};

int Time_Bomb::count = 0;

struct S2
{
  ~S2()
  {
    try {
      Time_Bomb* bptr = new Time_Bomb[20];
      delete [] bptr; // this should throw part-way through the cleanup
    }
    catch (...) { // but no exception should leave this destructor
    }
  }
};

int main()
{
  try {
    S2 s;
    throw false;
  }
  catch (...) {
  }
  return 0;
}