[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.

llvm-svn: 272247

2 files changed, 11 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 554d1abbed1..24a47d19421 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -2637,8 +2637,7 @@ Sema::InstantiateClassMembers(SourceLocation PointOfInstantiation,
             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);
       }
diff --git a/clang/test/SemaCXX/member-init.cpp b/clang/test/SemaCXX/member-init.cpp
index b3ee30b456e..65c8873117a 100644
--- a/clang/test/SemaCXX/member-init.cpp
+++ b/clang/test/SemaCXX/member-init.cpp
@@ -192,3 +192,13 @@ struct S {
   int x[3] = {[N] = 3};
 };
 }
+
+namespace PR28060 {
+template <class T>
+void foo(T v) {
+  struct s {
+    T *s = 0;
+  };
+}
+template void foo(int);
+}