r272247 - [Sema] Don't crash when a field w/ a mem-initializer clashes with a record name

[Kim Gräsman via cfe-commits]

On Thu, Jun 9, 2016 at 7:26 AM, David Majnemer via cfe-commits
<cfe-commits at lists.llvm.org> wrote:
> Author: majnemer
> Date: Thu Jun  9 00:26:56 2016
> New Revision: 272247
>
> URL: http://llvm.org/viewvc/llvm-project?rev=272247&view=rev
> Log:
> [Sema] Don't crash when a field w/ a mem-initializer clashes with a record name
>
> It is possible for a field and a class to have the same name.  In such
> cases, performing lookup for the field might return a result set with
> more than one entry.  An overzealous assertion fired, causing us to
> crash instead of using the non-class lookup result.
>
> This fixes PR28060.
>
> Modified:
>     cfe/trunk/lib/Sema/SemaTemplateInstantiate.cpp
>     cfe/trunk/test/SemaCXX/member-init.cpp
>
> Modified: cfe/trunk/lib/Sema/SemaTemplateInstantiate.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaTemplateInstantiate.cpp?rev=272247&r1=272246&r2=272247&view=diff
> ==============================================================================
> --- cfe/trunk/lib/Sema/SemaTemplateInstantiate.cpp (original)
> +++ cfe/trunk/lib/Sema/SemaTemplateInstantiate.cpp Thu Jun  9 00:26:56 2016
> @@ -2637,8 +2637,7 @@ Sema::InstantiateClassMembers(SourceLoca
>              Instantiation->getTemplateInstantiationPattern();
>          DeclContext::lookup_result Lookup =
>              ClassPattern->lookup(Field->getDeclName());
> -        assert(Lookup.size() == 1);
> -        FieldDecl *Pattern = cast<FieldDecl>(Lookup[0]);
> +        FieldDecl *Pattern = cast<FieldDecl>(Lookup.front());
>          InstantiateInClassInitializer(PointOfInstantiation, Field, Pattern,
>                                        TemplateArgs);
>        }

Now what if there is no match? Or is that guaranteed (given the prior assert)?

- Kim