[cfe-commits] r143399 - in /cfe/trunk: lib/CodeGen/CGBlocks.cpp lib/CodeGen/CGExpr.cpp test/CodeGenCXX/block-rvalue-reference-capture.cpp

[jahanian]

On Nov 2, 2011, at 7:59 AM, Douglas Gregor wrote:

> 
> On Nov 2, 2011, at 1:33 AM, John McCall wrote:
> 
>> On Oct 31, 2011, at 4:44 PM, Fariborz Jahanian wrote:
>>> Author: fjahanian
>>> Date: Mon Oct 31 18:44:33 2011
>>> New Revision: 143399
>>> 
>>> URL: http://llvm.org/viewvc/llvm-project?rev=143399&view=rev
>>> Log:
>>> Adds IRGen support for captured rvalue references in blocks.
>>> In this case, temporary value is copied into block descriptor
>>> as their own copy to work on. // rdar://9971124
>> 
>> Sorry for missing this earlier, but I really don't think is the right
>> thing to do.  Block captures of l-value references capture a
>> reference;  making block captures of r-value references capture
>> a copy is bizarrely inconsistent.
> 
> 
> What do you propose? Capture the reference, even though it's almost surely going to refer to a temporary?

In the absence of any precedence of how to treat rvalue reference in code gen. A compromise may be to make the
copy as is currently done, but establish a reference to it on entry to the block. In essence, temporary is moved to the
block descriptor. But I am not sure if this will make any difference in terms of semantics of such references.

- Fariborz

> 
> 	- Doug