Fix an issue with writing to PCH another included PCH, introduced by the "using an AST on-disk hash table for name lookup" commit.

When including a PCH and later re-emitting to another PCH, the name lookup tables of DeclContexts
may be incomplete, since we now lazily deserialize the visible decls of a particular name.
Fix the issue by iterating over the un-deserialized visible decls and completing the lookup tables
of DeclContexts before writing them out.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@111698 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 28 insertions, 0 deletions

diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index 30d540a00a..3dd7abab0c 100644
--- a/lib/AST/DeclBase.cpp
+++ b/lib/AST/DeclBase.cpp
@@ -667,6 +667,25 @@ ExternalASTSource::SetExternalVisibleDeclsForName(const DeclContext *DC,
   return List.getLookupResult();
 }
 
+void ExternalASTSource::MaterializeVisibleDeclsForName(const DeclContext *DC,
+                                                       DeclarationName Name,
+                                     llvm::SmallVectorImpl<NamedDecl*> &Decls) {
+  assert(DC->LookupPtr);
+  StoredDeclsMap &Map = *DC->LookupPtr;
+
+  // If there's an entry in the table the visible decls for this name have
+  // already been deserialized.
+  if (Map.find(Name) == Map.end()) {
+    StoredDeclsList &List = Map[Name];
+    for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
+      if (List.isNull())
+        List.setOnlyValue(Decls[I]);
+      else
+        List.AddSubsequentDecl(Decls[I]);
+    }
+  }
+}
+
 DeclContext::decl_iterator DeclContext::noload_decls_begin() const {
   return decl_iterator(FirstDecl);
 }
@@ -916,6 +935,15 @@ void DeclContext::makeDeclVisibleInContextImpl(NamedDecl *D) {
   DeclNameEntries.AddSubsequentDecl(D);
 }
 
+void DeclContext::MaterializeVisibleDeclsFromExternalStorage() {
+  ExternalASTSource *Source = getParentASTContext().getExternalSource();
+  assert(hasExternalVisibleStorage() && Source && "No external storage?");
+
+  if (!LookupPtr)
+    CreateStoredDeclsMap(getParentASTContext());
+  Source->MaterializeVisibleDecls(this);
+}
+
 /// Returns iterator range [First, Last) of UsingDirectiveDecls stored within
 /// this context.
 DeclContext::udir_iterator_range