[cfe-commits] New files for libcxxabi

[Marshall Clow]

On Jun 8, 2011, at 9:17 AM, Howard Hinnant wrote:

> On Jun 7, 2011, at 1:15 PM, Marshall Clow wrote:
> 
>> Implements the new [] and delete [] functionality.
>> With tests.
>> 
>> Comments please.
>> I'm not 100% sure that the exception handling is correct - so that's a good place to look ;-)
> 
> This is looking pretty good to me.  I have one trivial comment (1), and one non-trivial comment (2) that I'd like as many eyes as possible on.
> 
> Thanks Marshall!
> 
> 
> 1.  test_vector.cpp needs a standard LLVM/banner header.
> 
> 2.  In the catch clause of __cxa_vec_dtor:
> 
>        catch(...) {
>        //  if we've caught an exception while doing stack unwinding, then
>        //  there's really nothing we can do.
>            if ( std::uncaught_exception ())
>                std::terminate ();
>        //  otherwise, attempt to destruct the rest of the array and rethrow
>            __cxa_vec_cleanup ( array_address, idx, element_size, destructor );
>            throw ;         
>        }
> 
> I'm thinking that even if we're in an unwind, we should still attempt __cxa_vec_cleanup:
> 
>        catch(...) {
>        //  attempt to destruct the rest of the array and rethrow
>            __cxa_vec_cleanup ( array_address, idx, element_size, destructor );
>            throw ;         
>        }

I think that this code is better - the call to uncaught_exception inside the catch block is wrong, I think.

>     if ( NULL != destructor ) {
>         char *ptr = static_cast <char *> (array_address);
>         size_t idx = element_count;
>         const bool is_unwinding = std::uncaught_exception ();
>         
>         ptr +=  element_count * element_size;   // one past the last element
>         try {
>             while ( idx-- > 0 ) {
>                 ptr -= element_size;
>                 destructor ( ptr );
>             }
>         }
>         
>         catch(...) {
>         //  [15.2.3] If a destructor called during stack unwinding exits with
>         //  an exception, then std::terminate is called
>             if ( is_unwinding )
>                 std::terminate ();
>         //  otherwise, attempt to destruct the rest of the array and rethrow
>             __cxa_vec_cleanup ( array_address, idx, element_size, destructor );
>             throw ;         
>         }
>     }


-- Marshall