2 files changed, 129 insertions, 1 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index deeb7631917..7da1bf080c4 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -16,6 +16,7 @@
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/AST/Expr.h"
+#include "clang/AST/ExternalASTSource.h"
 #include "clang/AST/RecordLayout.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/TargetInfo.h"
@@ -36,7 +37,8 @@ ASTContext::ASTContext(const LangOptions& LOpts, SourceManager &SM,
                        bool FreeMem, unsigned size_reserve) : 
   GlobalNestedNameSpecifier(0), CFConstantStringTypeDecl(0), 
   ObjCFastEnumerationStateTypeDecl(0), SourceMgr(SM), LangOpts(LOpts), 
-  FreeMemory(FreeMem), Target(t), Idents(idents), Selectors(sels) {  
+  FreeMemory(FreeMem), Target(t), Idents(idents), Selectors(sels),
+  ExternalSource(0) {  
   if (size_reserve > 0) Types.reserve(size_reserve);    
   InitBuiltinTypes();
   BuiltinInfo.InitializeBuiltins(idents, Target, LangOpts.NoBuiltin);
@@ -91,6 +93,11 @@ ASTContext::~ASTContext() {
   TUDecl->Destroy(*this);
 }
 
+void 
+ASTContext::setExternalSource(llvm::OwningPtr<ExternalASTSource> &Source) {
+  ExternalSource.reset(Source.take());
+}
+
 void ASTContext::PrintStats() const {
   fprintf(stderr, "*** AST Context Stats:\n");
   fprintf(stderr, "  %d types total.\n", (int)Types.size());
@@ -195,6 +202,11 @@ void ASTContext::PrintStats() const {
     NumTypeName*sizeof(TypedefType)+NumTagged*sizeof(TagType)+
     NumTypeOfTypes*sizeof(TypeOfType)+NumTypeOfExprTypes*sizeof(TypeOfExprType)+
     NumExtQual*sizeof(ExtQualType)));
+
+  if (ExternalSource.get()) {
+    fprintf(stderr, "\n");
+    ExternalSource->PrintStats();
+  }
 }
 
 
@@ -3359,3 +3371,7 @@ ASTContext* ASTContext::Create(llvm::Deserializer& D) {
   
   return A;
 }
+
+ExternalASTSource::~ExternalASTSource() { }
+
+void ExternalASTSource::PrintStats() { }
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 763998e852e..be349428ecf 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -17,6 +17,7 @@
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/DeclTemplate.h"
+#include "clang/AST/ExternalASTSource.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/Type.h"
 #include "llvm/ADT/DenseMap.h"
@@ -439,11 +440,82 @@ DeclContext *DeclContext::getNextContext() {
   }
 }
 
+/// \brief Load the declarations within this lexical storage from an
+/// external source.
+void 
+DeclContext::LoadLexicalDeclsFromExternalStorage(ASTContext &Context) const {
+  ExternalASTSource *Source = Context.getExternalSource();
+  assert(hasExternalLexicalStorage() && Source && "No external storage?");
+
+  llvm::SmallVector<unsigned, 64> Decls;
+  if (Source->ReadDeclsLexicallyInContext(const_cast<DeclContext *>(this), 
+                                          Decls))
+    return;
+
+  // There is no longer any lexical storage in this context
+  ExternalLexicalStorage = false;
+
+  if (Decls.empty())
+    return;
+
+  // Resolve all of the declaration IDs into declarations, building up
+  // a chain of declarations via the Decl::NextDeclInContext field.
+  Decl *FirstNewDecl = 0;
+  Decl *PrevDecl = 0;
+  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
+    Decl *D = Source->GetDecl(Decls[I]);
+    if (PrevDecl)
+      PrevDecl->NextDeclInContext = D;
+    else
+      FirstNewDecl = D;
+
+    PrevDecl = D;
+  }
+
+  // Splice the newly-read declarations into the beginning of the list
+  // of declarations.
+  PrevDecl->NextDeclInContext = FirstDecl;
+  FirstDecl = FirstNewDecl;
+  if (!LastDecl)
+    LastDecl = PrevDecl;
+}
+
+void 
+DeclContext::LoadVisibleDeclsFromExternalStorage(ASTContext &Context) const {
+  DeclContext *This = const_cast<DeclContext *>(this);
+  ExternalASTSource *Source = Context.getExternalSource();
+  assert(hasExternalVisibleStorage() && Source && "No external storage?");
+
+  llvm::SmallVector<VisibleDeclaration, 64> Decls;
+  if (Source->ReadDeclsVisibleInContext(This, Decls))
+    return;
+
+  // There is no longer any visible storage in this context
+  ExternalVisibleStorage = false;
+
+  // Load the declaration IDs for all of the names visible in this
+  // context.
+  assert(!LookupPtr && "Have a lookup map before de-serialization?");
+  StoredDeclsMap *Map = new StoredDeclsMap;
+  LookupPtr = Map;
+  for (unsigned I = 0, N = Decls.size(); I != N; ++I) {
+    (*Map)[Decls[I].Name].setFromDeclIDs(Decls[I].Declarations);
+  }
+}
+
 DeclContext::decl_iterator DeclContext::decls_begin(ASTContext &Context) const {
+  if (hasExternalLexicalStorage())
+    LoadLexicalDeclsFromExternalStorage(Context);
+
+  // FIXME: Check whether we need to load some declarations from
+  // external storage.
   return decl_iterator(FirstDecl); 
 }
 
 DeclContext::decl_iterator DeclContext::decls_end(ASTContext &Context) const {
+  if (hasExternalLexicalStorage())
+    LoadLexicalDeclsFromExternalStorage(Context);
+
   return decl_iterator(); 
 }
 
@@ -491,6 +563,9 @@ DeclContext::lookup(ASTContext &Context, DeclarationName Name) {
   if (PrimaryContext != this)
     return PrimaryContext->lookup(Context, Name);
 
+  if (hasExternalVisibleStorage())
+    LoadVisibleDeclsFromExternalStorage(Context);
+
   /// If there is no lookup data structure, build one now by walking
   /// all of the linked DeclContexts (in declaration order!) and
   /// inserting their values.
@@ -595,3 +670,40 @@ DeclContext::getUsingDirectives(ASTContext &Context) const {
   return udir_iterator_range(reinterpret_cast<udir_iterator>(Result.first),
                              reinterpret_cast<udir_iterator>(Result.second));
 }
+
+void StoredDeclsList::materializeDecls(ASTContext &Context) {
+  if (isNull())
+    return;
+
+  switch ((DataKind)(Data & 0x03)) {
+  case DK_Decl:
+  case DK_Decl_Vector:
+    break;
+
+  case DK_DeclID: {
+    // Resolve this declaration ID to an actual declaration by
+    // querying the external AST source.
+    unsigned DeclID = Data >> 2;
+
+    ExternalASTSource *Source = Context.getExternalSource();
+    assert(Source && "No external AST source available!");
+
+    Data = reinterpret_cast<uintptr_t>(Source->GetDecl(DeclID));
+    break;
+  }
+
+  case DK_ID_Vector: {
+    // We have a vector of declaration IDs. Resolve all of them to
+    // actual declarations.
+    VectorTy &Vector = *getAsVector();
+    ExternalASTSource *Source = Context.getExternalSource();
+    assert(Source && "No external AST source available!");
+
+    for (unsigned I = 0, N = Vector.size(); I != N; ++I)
+      Vector[I] = reinterpret_cast<uintptr_t>(Source->GetDecl(Vector[I]));
+
+    Data = (Data & ~0x03) | DK_Decl_Vector;
+    break;
+  }
+  }
+}