[Debug Info PATCH] patches to generate unique identifier for external C++ types

[David Blaikie]

Please include test case changes along with whichever patch requires
them, generally that's a bit easier to keep track of rather than
having to pair a given change with a given patch.

The Clang change could use the code review feedback I gave earlier
today - have the unique string function return a SmallString & rely on
NRVO, rather than passing by reference. (also, you have a FIXME in
there about objective C++ - is there any reason you aren't just
checking both language values now? Or checking the language setting in
LangOpts (in there, CPlusPlus is true for any C++ variant, including
Objective C++) - but I'm happy to leave it out if you've got concerns
about Objective-C types when used in Objective C++, I know nothing
about such things)

The comment in DIBuilder::finalize might use some more detail. Two
different nodes will be added to the retained types list, but the
client (Clang in this instance) deduplicates those after the fact,
thus leaving the retained types list with duplicate nodes. Perhaps:

// Declarations and definitions of the same type may be retained. Some
clients RAUW these pairs, leaving duplicates in the retained types
list. Use a set to remove the duplicates while we transform the
TrackingVHs back into Values.

With those changes, please go ahead & commit these patches.

On Thu, Aug 29, 2013 at 2:33 PM, Manman Ren <manman.ren at gmail.com> wrote:
> Hi,
>
> I think it is a good idea to start a new thread :)
> Attached please find 3 patches: one for llvm (update DIBuilder to retain
> types with unique
> identifier), one for clang (to generate the unique identifier), the last for
> updating testing cases.
>
> Thanks,
> Manman