Add {ExternalSemaSource,SemaConsumer}::ForgetSema callback, and update PCHReader

to use it so it at least won't try to access Sema once it is gone.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@90261 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 1 deletions

diff --git a/lib/Sema/ParseAST.cpp b/lib/Sema/ParseAST.cpp
index 7c7df4bb61..898b3c230e 100644
--- a/lib/Sema/ParseAST.cpp
+++ b/lib/Sema/ParseAST.cpp
@@ -75,7 +75,7 @@ void clang::ParseAST(Preprocessor &PP, ASTConsumer *Consumer,
   while ((ADecl = P.RetrievePendingObjCImpDecl()))
     Consumer->HandleTopLevelDecl(ADecl.getAsVal<DeclGroupRef>());
 
-  // process any TopLevelDecls generated by #pragma weak
+  // Process any TopLevelDecls generated by #pragma weak.
   for (llvm::SmallVector<Decl*,2>::iterator
         I = S.WeakTopLevelDecls().begin(),
         E = S.WeakTopLevelDecls().end(); I != E; ++I)
@@ -83,6 +83,13 @@ void clang::ParseAST(Preprocessor &PP, ASTConsumer *Consumer,
 
   Consumer->HandleTranslationUnit(Ctx);
 
+  if (ExternalSemaSource *ESS =
+        dyn_cast_or_null<ExternalSemaSource>(Ctx.getExternalSource()))
+    ESS->ForgetSema();
+
+  if (SemaConsumer *SC = dyn_cast<SemaConsumer>(Consumer))
+    SC->ForgetSema();
+
   if (PrintStats) {
     fprintf(stderr, "\nSTATISTICS:\n");
     P.getActions().PrintStats();