Implement correct name lookup inside an initializer of a C++ class static data member.

Fixes "test/CXX/basic/basic.lookup/basic.lookup.unqual/p13.cpp" test case.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@73652 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Parse/Action.h b/include/clang/Parse/Action.h
index f1207e4..ba480c5 100644
--- a/include/clang/Parse/Action.h
+++ b/include/clang/Parse/Action.h
@@ -248,6 +248,19 @@
   virtual void ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS) {
   }
 
+  /// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse an
+  /// initializer for the declaration 'Dcl'.
+  /// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
+  /// static data member of class X, names should be looked up in the scope of
+  /// class X.
+  virtual void ActOnCXXEnterDeclInitializer(Scope *S, DeclPtrTy Dcl) {
+  }
+
+  /// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
+  /// initializer for the declaration 'Dcl'.
+  virtual void ActOnCXXExitDeclInitializer(Scope *S, DeclPtrTy Dcl) {
+  }
+
   /// ActOnDeclarator - This callback is invoked when a declarator is parsed and
   /// 'Init' specifies the initializer if any.  This is for things like:
   /// "int X = 4" or "typedef int foo".
diff --git a/lib/Parse/ParseDecl.cpp b/lib/Parse/ParseDecl.cpp
index 9073c6d..efabf3a 100644
--- a/lib/Parse/ParseDecl.cpp
+++ b/lib/Parse/ParseDecl.cpp
@@ -402,7 +402,14 @@
       SourceLocation DelLoc = ConsumeToken();
       Actions.SetDeclDeleted(ThisDecl, DelLoc);
     } else {
+      if (getLang().CPlusPlus)
+        Actions.ActOnCXXEnterDeclInitializer(CurScope, ThisDecl);
+
       OwningExprResult Init(ParseInitializer());
+
+      if (getLang().CPlusPlus)
+        Actions.ActOnCXXExitDeclInitializer(CurScope, ThisDecl);
+
       if (Init.isInvalid()) {
         SkipUntil(tok::semi, true, true);
         return DeclPtrTy();
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index bbfab88..579fe37 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -1721,6 +1721,17 @@
   /// defining scope.
   virtual void ActOnCXXExitDeclaratorScope(Scope *S, const CXXScopeSpec &SS);
 
+  /// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse an
+  /// initializer for the declaration 'Dcl'.
+  /// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
+  /// static data member of class X, names should be looked up in the scope of
+  /// class X.
+  virtual void ActOnCXXEnterDeclInitializer(Scope *S, DeclPtrTy Dcl);
+
+  /// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
+  /// initializer for the declaration 'Dcl'.
+  virtual void ActOnCXXExitDeclInitializer(Scope *S, DeclPtrTy Dcl);
+
   // ParseObjCStringLiteral - Parse Objective-C string literals.
   virtual ExprResult ParseObjCStringLiteral(SourceLocation *AtLocs, 
                                             ExprTy **Strings,
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index dcf11c5..bb1f50f 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -2828,3 +2828,58 @@
   
   return false;
 }
+
+/// ActOnCXXEnterDeclInitializer - Invoked when we are about to parse an
+/// initializer for the declaration 'Dcl'.
+/// After this method is called, according to [C++ 3.4.1p13], if 'Dcl' is a
+/// static data member of class X, names should be looked up in the scope of
+/// class X.
+void Sema::ActOnCXXEnterDeclInitializer(Scope *S, DeclPtrTy Dcl) {
+  Decl *D = Dcl.getAs<Decl>();
+  // If there is no declaration, there was an error parsing it.
+  if (D == 0)
+    return;
+
+  // Check whether it is a declaration with a nested name specifier like
+  // int foo::bar;
+  if (!D->isOutOfLine())
+    return;
+  
+  // C++ [basic.lookup.unqual]p13
+  //
+  // A name used in the definition of a static data member of class X
+  // (after the qualified-id of the static member) is looked up as if the name
+  // was used in a member function of X.
+  
+  // Change current context into the context of the initializing declaration.
+  
+  assert(PreDeclaratorDC == 0 && "Previous declarator context not popped?");
+  PreDeclaratorDC = static_cast<DeclContext*>(S->getEntity());
+  CurContext = D->getDeclContext();
+  assert(CurContext && "No context?");
+  S->setEntity(CurContext);
+}
+
+/// ActOnCXXExitDeclInitializer - Invoked after we are finished parsing an
+/// initializer for the declaration 'Dcl'.
+void Sema::ActOnCXXExitDeclInitializer(Scope *S, DeclPtrTy Dcl) {
+  Decl *D = Dcl.getAs<Decl>();
+  // If there is no declaration, there was an error parsing it.
+  if (D == 0)
+    return;
+
+  // Check whether it is a declaration with a nested name specifier like
+  // int foo::bar;
+  if (!D->isOutOfLine())
+    return;
+
+  assert(S->getEntity() == D->getDeclContext() && "Context imbalance!");
+  S->setEntity(PreDeclaratorDC);
+  PreDeclaratorDC = 0;
+
+  // Reset CurContext to the nearest enclosing context.
+  while (!S->getEntity() && S->getParent())
+    S = S->getParent();
+  CurContext = static_cast<DeclContext*>(S->getEntity());
+  assert(CurContext && "No context?");
+}
diff --git a/test/CXX/basic/basic.lookup/basic.lookup.unqual/p13.cpp b/test/CXX/basic/basic.lookup/basic.lookup.unqual/p13.cpp
index 037d590..afd6623 100644
--- a/test/CXX/basic/basic.lookup/basic.lookup.unqual/p13.cpp
+++ b/test/CXX/basic/basic.lookup/basic.lookup.unqual/p13.cpp
@@ -1,5 +1,4 @@
 // RUN: clang-cc -fsyntax-only -verify %s
-// XFAIL
 
 struct S {
   static const int f0 = 0;