Lazily load the "next" namespace in the chain of NamespaceDecls, to

eliminate some excessive recursion and deserialization.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@117476 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 17 insertions, 11 deletions

diff --git a/include/clang/AST/Decl.h b/include/clang/AST/Decl.h
index 46cc973a86..b045fef496 100644
--- a/include/clang/AST/Decl.h
+++ b/include/clang/AST/Decl.h
@@ -238,7 +238,7 @@ class NamespaceDecl : public NamedDecl, public DeclContext {
   // NextNamespace points to the next extended declaration.
   // OrigNamespace points to the original namespace declaration.
   // OrigNamespace of the first namespace decl points to its anonymous namespace
-  NamespaceDecl *NextNamespace;
+  LazyDeclPtr NextNamespace;
 
   /// \brief A pointer to either the original namespace definition for
   /// this namespace (if the boolean value is false) or the anonymous
@@ -256,7 +256,7 @@ class NamespaceDecl : public NamedDecl, public DeclContext {
 
   NamespaceDecl(DeclContext *DC, SourceLocation L, IdentifierInfo *Id)
     : NamedDecl(Namespace, DC, L, Id), DeclContext(Namespace),
-      IsInline(false), NextNamespace(0), OrigOrAnonNamespace(0, true) { }
+      IsInline(false), NextNamespace(), OrigOrAnonNamespace(0, true) { }
 
 public:
   static NamespaceDecl *Create(ASTContext &C, DeclContext *DC,
@@ -287,8 +287,10 @@ public:
 
   /// \brief Return the next extended namespace declaration or null if there
   /// is none.
-  NamespaceDecl *getNextNamespace() { return NextNamespace; }
-  const NamespaceDecl *getNextNamespace() const { return NextNamespace; }
+  NamespaceDecl *getNextNamespace();
+  const NamespaceDecl *getNextNamespace() const { 
+    return const_cast<NamespaceDecl *>(this)->getNextNamespace();
+  }
 
   /// \brief Set the next extended namespace declaration.
   void setNextNamespace(NamespaceDecl *ND) { NextNamespace = ND; }
@@ -337,9 +339,9 @@ public:
 
   SourceLocation getLBracLoc() const { return LBracLoc; }
   SourceLocation getRBracLoc() const { return RBracLoc; }
-  void setLBracLoc(SourceLocation LBrace) { LBracLoc = LBrace; }
-  void setRBracLoc(SourceLocation RBrace) { RBracLoc = RBrace; }
-
+  void setLBracLoc(SourceLocation L) { LBracLoc = L; }
+  void setRBracLoc(SourceLocation R) { RBracLoc = R; }
+  
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classof(const NamespaceDecl *D) { return true; }
diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 5cc745d40d..9c7654b9cb 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -1911,6 +1911,11 @@ NamespaceDecl *NamespaceDecl::Create(ASTContext &C, DeclContext *DC,
   return new (C) NamespaceDecl(DC, L, Id);
 }
 
+NamespaceDecl *NamespaceDecl::getNextNamespace() {
+  return dyn_cast_or_null<NamespaceDecl>(
+                       NextNamespace.get(getASTContext().getExternalSource()));
+}
+
 ImplicitParamDecl *ImplicitParamDecl::Create(ASTContext &C, DeclContext *DC,
     SourceLocation L, IdentifierInfo *Id, QualType T) {
   return new (C) ImplicitParamDecl(ImplicitParam, DC, L, Id, T);
diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 7192195501..4b1d48162e 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -692,10 +692,9 @@ void ASTDeclReader::VisitLinkageSpecDecl(LinkageSpecDecl *D) {
 void ASTDeclReader::VisitNamespaceDecl(NamespaceDecl *D) {
   VisitNamedDecl(D);
   D->IsInline = Record[Idx++];
-  D->setLBracLoc(ReadSourceLocation(Record, Idx));
-  D->setRBracLoc(ReadSourceLocation(Record, Idx));
-  D->setNextNamespace(
-                    cast_or_null<NamespaceDecl>(Reader.GetDecl(Record[Idx++])));
+  D->LBracLoc = ReadSourceLocation(Record, Idx);
+  D->RBracLoc = ReadSourceLocation(Record, Idx);
+  D->NextNamespace = Record[Idx++];
 
   bool IsOriginal = Record[Idx++];
   D->OrigOrAnonNamespace.setInt(IsOriginal);