[index] Add a message for the assertion, NFC.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@262991 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Index/IndexingContext.cpp b/lib/Index/IndexingContext.cpp
index fe814ff25a643abb53f51b647a99434c14f1c614..238de57ccd49e1021bf89f3a86d3c237c71dcbfa 100644 (file)
--- a/lib/Index/IndexingContext.cpp
+++ b/lib/Index/IndexingContext.cpp
@@ -299,7 +299,8 @@ bool IndexingContext::handleDeclOccurrence(const Decl *D, SourceLocation Loc,
     Parent = getCanonicalDecl(Parent);
   assert(!Parent || !Parent->isImplicit() ||
          isa<FunctionDecl>(Parent) ||
-         isa<ObjCInterfaceDecl>(Parent) || isa<ObjCMethodDecl>(Parent));
+         isa<ObjCInterfaceDecl>(Parent) || isa<ObjCMethodDecl>(Parent) &&
+         "unexpected implicit parent!");
 
   SmallVector<SymbolRelation, 6> FinalRelations;
   FinalRelations.reserve(Relations.size()+1);