On Oct 12, 2007, Alexandre Oliva <aoliva@redhat.com> wrote:

> On Oct 11, 2007, "Richard Guenther" <richard.guenther@gmail.com> wrote:
>> The extra checking triggers PR33735.

> Thanks.  This is an interesting testcase.  It is a variant of the
> problem H-P had reported, but I hadn't realized there was a lingering
> bug then.

So the patch below reverts the work around for H-P's testcase, and
fixes the problem explained below.

> The problem is that an exception thrown during stack unwinding is
> supposed to call terminate(), but AFAICT, when we inline the dtor of
> temporaries (other than the exception object) in the throw expression
> itself, calls that are brought in as part of the destructor get EH
> edges as if they were before the throw expression, escaping the
> requirement to call terminate in case they throw.

> Now, since there aren't edges from the original dtor call to enclosing
> catch or clean-up points, when we look for such edges at the time of
> adjusting the PHI nodes, we don't find them.  Oops.

The patch below recognizes an ERT_ALLOWED_EXCEPTIONS EH region with an
empty type list and prevents the enclosing try block from being
regarded as reachable from within.  With it, both testcases compile
correctly.

libstdc++ builds with it; starting bootstrap and regtesting on
x86_64-linux-gnu right now.  Ok to install?