Add a comment to Sema::ActOnTranslationUnitScope().

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@73450 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index a5f243816abd35d9821ac2e9ad9b779e4881b458..254080a81a860c74e6110186a30825c50592164d 100644 (file)
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -125,6 +125,7 @@ void Sema::ActOnTranslationUnitScope(SourceLocation Loc, Scope *S) {
   
   if (!PP.getLangOptions().ObjC1) return;
   
+  // Built-in ObjC types may already be set by PCHReader (hence isNull checks).
   if (Context.getObjCSelType().isNull()) {
     // Synthesize "typedef struct objc_selector *SEL;"
     RecordDecl *SelTag = CreateStructDecl(Context, "objc_selector");