Hi!
The following code terminates on g++ 5.2.1, 4.9.3 and 4.8.4:

namespace {
struct IFoo { virtual void foo() = 0; };
struct IBar { virtual void bar() = 0; };

struct FooBar : private IBar, private IFoo
{
    void call_foo()
    {
        try
        {
            static_cast<IFoo*>(this)->foo();
        }
        catch( ... ) {}
    }
    void foo() { throw 1; }
    void bar()  {}
};

void test()
{
    FooBar foobar;
    foobar.call_foo();
}
}
int main()
{
    test();
    return 0;
}

when compiled with O3 optimization
  g++ -O3 -Wall -Wextra -pedantic main.cpp && ./a.out
with following error:
  terminate called after throwing an instance of 'int'

For the example see:
  http://coliru.stacked-crooked.com/a/2bab7c03ff7c870b

It seems that __cxa_begin_catch, __cxa_end_catch calls do not get generated:

(anonymous namespace)::FooBar::bar():
	rep ret
(anonymous namespace)::FooBar::foo():
	movl	$4, %edi
	subq	$8, %rsp
	call	__cxa_allocate_exception
	xorl	%edx, %edx
	movl	$1, (%rax)
	movl	typeinfo for int, %esi
	movq	%rax, %rdi
	call	__cxa_throw
non-virtual thunk to (anonymous namespace)::FooBar::foo():
	subq	$8, %rdi
	jmp	.LTHUNK0
main:
	subq	$24, %rsp
	leaq	8(%rsp), %rdi
	movq	vtable for (anonymous namespace)::FooBar+16, (%rsp)
	movq	vtable for (anonymous namespace)::FooBar+48, 8(%rsp)
	call	non-virtual thunk to (anonymous namespace)::FooBar::foo()
	xorl	%eax, %eax
	addq	$24, %rsp
	ret

When I comment-out the IBar::bar() interface method, call the foo() method without static cast, use an older compiler (<= 4.6.4), or do some other code experiments then everything works as expected: 

  - terminate:               http://goo.gl/jcgPn6
  - single virtual function: http://goo.gl/cayyoO
  - no static cast:          http://goo.gl/i9N4pD
  - O1 + noinline:           http://goo.gl/PYazij
  - g++ 4.6.4:               http://goo.gl/uWQ6aU

Thanks in advance.