[llvm] r229352 - IR: Properly return nullptr when getAggregateElement is out-of-bounds

[Tom Stellard]

On Sat, Mar 14, 2015 at 02:52:25PM +0100, Björn Steinbrink wrote:
> Hi Tom, Hi David,
> 
> On 2015.02.16 04:02:10 -0000, David Majnemer wrote:
> > Author: majnemer
> > Date: Sun Feb 15 22:02:09 2015
> > New Revision: 229352
> > 
> > URL: http://llvm.org/viewvc/llvm-project?rev=229352&view=rev
> > Log:
> > IR: Properly return nullptr when getAggregateElement is out-of-bounds
> > 
> > We didn't properly handle the out-of-bounds case for
> > ConstantAggregateZero and UndefValue.  This would manifest as a crash
> > when the constant folder was asked to fold a load of a constant global
> > whose struct type has no operands.
> > 
> > This fixes PR22595.
> 
> Could this be added to 3.5.2?
> 

This adds a new function to two difference classes, which can
break the ABI in some cases.  According to abi-compliance-checker:


"You can add virtual functions at end of leaf classes with exported
 constructors."

I have a buildbot setup to check abi compliance, so if you move these
functions to the end of the classes, I will approve merging it, but if
this is not enough to ensure ABI compliance, I will revert it before the release.

-Tom

> Cheers
> Björn