[llvm] r212203 - Don't try to construct debug LexicalScopes hierarchy for functions that do not have top level debug information.

[Duncan P. N. Exon Smith]

> On 2014 Jul 7, at 20:22, David Blaikie <dblaikie at gmail.com> wrote:
> 
> On Thu, Jul 3, 2014 at 6:01 PM, Aditya Nandakumar
> <aditya_nandakumar at apple.com> wrote:
>> Thanks Duncan
>> Bug point reduced it from 27MB to about 3.7. I ran it through opt and
>> brought it down to 2.4MB and am unable to reduce further. Hopefully this is
>> not too big.
> 
> I'll have to take a look, though I'm a bit concerned that a reduced IR
> is going to be tricky to actually pinpoint the original source of the
> problem as the IR may already contain the bad debug info metadata at
> this point... and I won't be able to discover where that was
> introduced (by which optimization, etc).
> 
> But I'll take a look, see if I can create something by hand, etc...
> and see how I go.
> 
> Thanks,
> - David

Heh... doesn't sound fun.  FWIW, the source file (27MB) is from pre-LTO
optimizations -- i.e., it's the merged bitcode at the beginning of LTO.
If you think that would be more helpful than the bugpoint-reduced
version, Aditya might still have it around.