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

3 files changed, 99 insertions, 1 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
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index b24b35309a..6e5638b3c8 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -790,6 +790,44 @@ public:
     return Key;
   }
 
+  external_key_type GetExternalKey(const internal_key_type& Key) const {
+    ASTContext *Context = Reader.getContext();
+    switch (Key.Kind) {
+    case DeclarationName::Identifier:
+      return DeclarationName((IdentifierInfo*)Key.Data);
+
+    case DeclarationName::ObjCZeroArgSelector:
+    case DeclarationName::ObjCOneArgSelector:
+    case DeclarationName::ObjCMultiArgSelector:
+      return DeclarationName(Selector(Key.Data));
+
+    case DeclarationName::CXXConstructorName:
+      return Context->DeclarationNames.getCXXConstructorName(
+                           Context->getCanonicalType(Reader.GetType(Key.Data)));
+
+    case DeclarationName::CXXDestructorName:
+      return Context->DeclarationNames.getCXXDestructorName(
+                           Context->getCanonicalType(Reader.GetType(Key.Data)));
+
+    case DeclarationName::CXXConversionFunctionName:
+      return Context->DeclarationNames.getCXXConversionFunctionName(
+                           Context->getCanonicalType(Reader.GetType(Key.Data)));
+
+    case DeclarationName::CXXOperatorName:
+      return Context->DeclarationNames.getCXXOperatorName(
+                                         (OverloadedOperatorKind)Key.Data);
+
+    case DeclarationName::CXXLiteralOperatorName:
+      return Context->DeclarationNames.getCXXLiteralOperatorName(
+                                                     (IdentifierInfo*)Key.Data);
+
+    case DeclarationName::CXXUsingDirective:
+      return DeclarationName::getUsingDirectiveName();
+    }
+
+    llvm_unreachable("Invalid Name Kind ?");
+  }
+
   static std::pair<unsigned, unsigned>
   ReadKeyDataLength(const unsigned char*& d) {
     using namespace clang::io;
@@ -3197,6 +3235,35 @@ ASTReader::FindExternalVisibleDeclsByName(const DeclContext *DC,
   return const_cast<DeclContext*>(DC)->lookup(Name);
 }
 
+void ASTReader::MaterializeVisibleDecls(const DeclContext *DC) {
+  assert(DC->hasExternalVisibleStorage() &&
+         "DeclContext has no visible decls in storage");
+
+  llvm::SmallVector<NamedDecl *, 64> Decls;
+  // There might be visible decls in multiple parts of the chain, for the TU
+  // and namespaces.
+  DeclContextInfos &Infos = DeclContextOffsets[DC];
+  for (DeclContextInfos::iterator I = Infos.begin(), E = Infos.end();
+       I != E; ++I) {
+    if (!I->NameLookupTableData)
+      continue;
+
+    ASTDeclContextNameLookupTable *LookupTable =
+        (ASTDeclContextNameLookupTable*)I->NameLookupTableData;
+    for (ASTDeclContextNameLookupTable::item_iterator
+           ItemI = LookupTable->item_begin(),
+           ItemEnd = LookupTable->item_end() ; ItemI != ItemEnd; ++ItemI) {
+      ASTDeclContextNameLookupTable::item_iterator::value_type Val
+          = *ItemI;
+      ASTDeclContextNameLookupTrait::data_type Data = Val.second;
+      Decls.clear();
+      for (; Data.first != Data.second; ++Data.first)
+        Decls.push_back(cast<NamedDecl>(GetDecl(*Data.first)));
+      MaterializeVisibleDeclsForName(DC, Val.first, Decls);
+    }
+  }
+}
+
 void ASTReader::PassInterestingDeclsToConsumer() {
   assert(Consumer);
   while (!InterestingDecls.empty()) {
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 5deaf3d475..f47ad3c4d7 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -2032,7 +2032,10 @@ uint64_t ASTWriter::WriteDeclContextVisibleBlock(ASTContext &Context,
     return 0;
 
   // Force the DeclContext to build a its name-lookup table.
-  DC->lookup(DeclarationName());
+  if (DC->hasExternalVisibleStorage())
+    DC->MaterializeVisibleDeclsFromExternalStorage();
+  else
+    DC->lookup(DeclarationName());
 
   // Serialize the contents of the mapping used for lookup. Note that,
   // although we have two very different code paths, the serialized