4 files changed, 29 insertions, 8 deletions

diff --git a/clang/include/clang/AST/Expr.h b/clang/include/clang/AST/Expr.h
index 0490aab2001..812b5ca642e 100644
--- a/clang/include/clang/AST/Expr.h
+++ b/clang/include/clang/AST/Expr.h
@@ -49,15 +49,21 @@ class Expr : public Stmt {
   /// (C++ [temp.dep.constexpr]).
   bool ValueDependent : 1;
 
+  /// Implicit - Whether this expression was implicitly created by the
+  /// implementation, rather than written explicitly by the user.
+  bool Implicit : 1;
+
 protected:
   // FIXME: Eventually, this constructor should go away and we should
   // require every subclass to provide type/value-dependence
   // information.
   Expr(StmtClass SC, QualType T) 
-    : Stmt(SC), TypeDependent(false), ValueDependent(false) { setType(T); }
+    : Stmt(SC), TypeDependent(false), ValueDependent(false), Implicit(false) {
+    setType(T); 
+  }
 
   Expr(StmtClass SC, QualType T, bool TD, bool VD)
-    : Stmt(SC), TypeDependent(TD), ValueDependent(VD) {
+    : Stmt(SC), TypeDependent(TD), ValueDependent(VD), Implicit(false) {
     setType(T);
   }
 
@@ -99,6 +105,14 @@ public:
   /// @endcode
   bool isTypeDependent() const { return TypeDependent; }
 
+  /// isImplicit - Determines whether this expression was implicitly
+  /// created by the implementation to express the semantics of an
+  /// implicit operation, such as an implicit conversion or implicit
+  /// reference to "this". When false, this expression was written
+  /// directly in the source code.
+  bool isImplicit() const { return Implicit; }
+  void setImplicit(bool I = true) { Implicit = I; }
+
   /// SourceLocation tokens are not useful in isolation - they are low level
   /// value objects created/interpreted by SourceManager. We assume AST
   /// clients will have a pointer to the respective SourceManager.
@@ -982,7 +996,9 @@ class ImplicitCastExpr : public CastExpr {
 
 public:
   ImplicitCastExpr(QualType ty, Expr *op, bool Lvalue) : 
-    CastExpr(ImplicitCastExprClass, ty, op), LvalueCast(Lvalue) {}
+    CastExpr(ImplicitCastExprClass, ty, op), LvalueCast(Lvalue) {
+    setImplicit(true);
+  }
 
   virtual SourceRange getSourceRange() const {
     return getSubExpr()->getSourceRange();
@@ -1671,9 +1687,7 @@ public:
 
   // Explicit InitListExpr's originate from source code (and have valid source
   // locations). Implicit InitListExpr's are created by the semantic analyzer.
-  bool isExplicit() {
-    return LBraceLoc.isValid() && RBraceLoc.isValid();
-  }
+  bool isExplicit() { return !isImplicit(); }
   
   virtual SourceRange getSourceRange() const {
     return SourceRange(LBraceLoc, RBraceLoc);
diff --git a/clang/lib/AST/StmtPrinter.cpp b/clang/lib/AST/StmtPrinter.cpp
index 679c8974975..7456e8cca9e 100644
--- a/clang/lib/AST/StmtPrinter.cpp
+++ b/clang/lib/AST/StmtPrinter.cpp
@@ -757,8 +757,10 @@ void StmtPrinter::VisitCallExpr(CallExpr *Call) {
   OS << ")";
 }
 void StmtPrinter::VisitMemberExpr(MemberExpr *Node) {
-  PrintExpr(Node->getBase());
-  OS << (Node->isArrow() ? "->" : ".");
+  if (!Node->getBase()->isImplicit()) {
+    PrintExpr(Node->getBase());
+    OS << (Node->isArrow() ? "->" : ".");
+  }
   OS << Node->getMemberDecl()->getNameAsString();
 }
 void StmtPrinter::VisitExtVectorElementExpr(ExtVectorElementExpr *Node) {
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index bf04042ef8a..6db6ea19afd 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -444,6 +444,7 @@ Sema::BuildAnonymousStructUnionMemberReference(SourceLocation Loc,
 
     BaseObjectExpr = new DeclRefExpr(BaseObject, BaseObject->getType(),
                                      SourceLocation());
+    BaseObjectExpr->setImplicit();
     ExtraQuals 
       = Context.getCanonicalType(BaseObject->getType()).getCVRQualifiers();
   } else if (BaseObjectExpr) {
@@ -473,6 +474,7 @@ Sema::BuildAnonymousStructUnionMemberReference(SourceLocation Loc,
           BaseObjectExpr = new CXXThisExpr(SourceLocation(),
                                            MD->getThisType(Context));
           BaseObjectIsPointer = true;
+          BaseObjectExpr->setImplicit();
         }
       } else {
         return Diag(Loc, diag::err_invalid_member_use_in_static_method)
@@ -500,6 +502,7 @@ Sema::BuildAnonymousStructUnionMemberReference(SourceLocation Loc,
     }
     Result = new MemberExpr(Result, BaseObjectIsPointer, *FI,
                             OpLoc, MemberType);
+    Result->setImplicit();
     BaseObjectIsPointer = false;
     ExtraQuals = Context.getCanonicalType(MemberType).getCVRQualifiers();
     OpLoc = SourceLocation();
@@ -661,6 +664,7 @@ Sema::ExprResult Sema::ActOnDeclarationNameExpr(Scope *S, SourceLocation Loc,
           // Build the implicit member access expression.
           Expr *This = new CXXThisExpr(SourceLocation(),
                                        MD->getThisType(Context));
+          This->setImplicit();
           return new MemberExpr(This, true, cast<NamedDecl>(D), 
                                 SourceLocation(), MemberType);
         }
diff --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 031fe27ddf7..6a9275fbe8a 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -90,6 +90,7 @@ void InitListChecker::CheckImplicitInitList(InitListExpr *ParentIList,
                                        &InitExprs[0], InitExprs.size(), 
                                        SourceLocation(),
                                        ParentIList->hadDesignators());
+  ILE->setImplicit();
   ILE->setType(T);
 
   // Modify the parent InitListExpr to point to the implicit InitListExpr.