[LLVMdev] [PATCH] Circular Buffered Debug Stream

[Chris Lattner]

On Dec 21, 2009, at 12:20 PM, David Greene wrote:
>>> +    /// flushBuffer - Dump the contents of the buffer to Stream.
>>> +    ///
>>> +    void flushBuffer(void) {
>>> +      // Write the older portion of the buffer.
>>> +      TheStream->write(Cur, BufferArray + BufferSize - Cur);
>>> +      // Write the newer portion of the buffer.
>>> +      TheStream->write(BufferArray, Cur - BufferArray);
>>> +      Cur = BufferArray;
>>> +    }
>>
>> Is this correct in the case when the circular buffer hasn't  
>> completely
>> filled yet?
>
> Hmm...Depends on what's "correct."  :)  You'll get a bunch of garbage
> output but I don't think it should fault or anything.  I don't think
> there's a way of knowing whether the buffer got filled all the way to
> the end unless we add another member variable.  In practice, it will
> almost always be filled.

Correct is not emitting garbage.  Adding another member is worth it.   
Saving 4 bytes per circular_raw_ostream doesn't matter when you have a  
multi kilobyte buffer it is managing.

Aside from that, your patch looks fine.  Please fix this and commit it,

-Chris