[cfe-commits] New files for libcxxabi

[Howard Hinnant]

On Jun 8, 2011, at 10:32 AM, Marshall Clow wrote:

> 
> 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 ;         
>>       }
>> 
>> However this is admittedly confusing territory.  I ran test_vector.cpp both ways, and it passed.  Comments?
> 
> The sample code at <http://www.codesourcery.com/public/cxx-abi/gcc-vec.cc> has code to check for this case - and I just noticed that I implemented it "incorrectly" (i.e, differently than that). I think that code is clearer about what is going on.

Hmm.. I notice that sample code also does a recursive call to itself, which may be why it is checking for unwinding.

Howard