[modules] If we reach a definition of a class for which we already have a

non-visible definition, skip the new definition and make the old one visible
instead of trying to parse it again and failing horribly. C++'s ODR allows
us to assume that the two definitions are identical.

llvm-svn: 233250

1 files changed, 14 insertions, 0 deletions

diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 10de9f754de..184e6d7772a 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -3793,10 +3793,24 @@ void ASTDeclReader::UpdateDecl(Decl *D, ModuleFile &ModuleFile,
     case UPD_STATIC_LOCAL_NUMBER:
       Reader.Context.setStaticLocalNumber(cast<VarDecl>(D), Record[Idx++]);
       break;
+
     case UPD_DECL_MARKED_OPENMP_THREADPRIVATE:
       D->addAttr(OMPThreadPrivateDeclAttr::CreateImplicit(
           Reader.Context, ReadSourceRange(Record, Idx)));
       break;
+
+    case UPD_DECL_EXPORTED:
+      unsigned SubmoduleID = readSubmoduleID(Record, Idx);
+      Module *Owner = SubmoduleID ? Reader.getSubmodule(SubmoduleID) : nullptr;
+      if (Owner && Owner->NameVisibility != Module::AllVisible) {
+        // If Owner is made visible at some later point, make this declaration
+        // visible too.
+        Reader.HiddenNamesMap[Owner].HiddenDecls.push_back(D);
+      } else {
+        // The declaration is now visible.
+        D->Hidden = false;
+      }
+      break;
     }
   }
 }