[modules] Add an assert for redeclarations that we never added to their redecl

chain and fix the cases where it fires.

 * Handle the __va_list_tag as a predefined decl. Previously we failed to merge
   sometimes it because it's not visible to name lookup. (In passing, remove
   redundant __va_list_tag typedefs that we were creating for some ABIs. These
   didn't affect the mangling or representation of the type.)

 * For Decls derived from Redeclarable that are not in fact redeclarable
   (implicit params, function params, ObjC type parameters), remove them from
   the list of expected redeclarable decls.

llvm-svn: 243259

1 files changed, 5 insertions, 4 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 520c3418b26..0c4dab4065b 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -5762,10 +5762,6 @@ QualType ASTReader::GetType(TypeID ID) {
       T = Context.ARCUnbridgedCastTy;
       break;
 
-    case PREDEF_TYPE_VA_LIST_TAG:
-      T = Context.getVaListTagType();
-      break;
-
     case PREDEF_TYPE_BUILTIN_FN:
       T = Context.BuiltinFnTy;
       break;
@@ -6078,6 +6074,9 @@ static Decl *getPredefinedDecl(ASTContext &Context, PredefinedDeclIDs ID) {
   case PREDEF_DECL_BUILTIN_VA_LIST_ID:
     return Context.getBuiltinVaListDecl();
 
+  case PREDEF_DECL_VA_LIST_TAG:
+    return Context.getVaListTagDecl();
+
   case PREDEF_DECL_EXTERN_C_CONTEXT_ID:
     return Context.getExternCContextDecl();
   }
@@ -8142,6 +8141,8 @@ void ASTReader::finishPendingActions() {
     assert(PendingDeclChainsKnown.empty());
     PendingDeclChains.clear();
 
+    assert(RedeclsDeserialized.empty() && "some redecls not wired up");
+
     // Make the most recent of the top-level declarations visible.
     for (TopLevelDeclsMap::iterator TLD = TopLevelDecls.begin(),
            TLDEnd = TopLevelDecls.end(); TLD != TLDEnd; ++TLD) {