Remove vtables from the Stmt hierarchy; this was pretty easy as

there were only three virtual methods of any significance.

The primary way to grab child iterators now is with
  Stmt::child_range children();
  Stmt::const_child_range children() const;
where a child_range is just a std::pair of iterators suitable for
being llvm::tie'd to some locals.  I've left the old child_begin()
and child_end() accessors in place, but it's probably a substantial
penalty to grab the iterators individually now, since the
switch-based dispatch is kindof inherently slower than vtable
dispatch.  Grabbing them together is probably a slight win over the
status quo, although of course we could've achieved that with vtables, too.

I also reclassified SwitchCase (correctly) as an abstract Stmt
class, which (as the first such class that wasn't an Expr subclass)
required some fiddling in a few places.

There are somewhat gross metaprogramming hooks in place to ensure
that new statements/expressions continue to implement
getSourceRange() and children().  I had to work around a recent clang
bug;  dgregor actually fixed it already, but I didn't want to
introduce a selfhosting dependency on ToT.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125183 91177308-0d34-0410-b5e6-96231b3b80d8

20 files changed, 438 insertions, 934 deletions

diff --git a/include/clang/AST/Expr.h b/include/clang/AST/Expr.h
index 8c28d52f49..2977d75f30 100644
--- a/include/clang/AST/Expr.h
+++ b/include/clang/AST/Expr.h
@@ -54,8 +54,6 @@ typedef llvm::SmallVector<CXXBaseSpecifier*, 4> CXXCastPath;
 class Expr : public Stmt {
   QualType TR;
 
-  virtual void ANCHOR(); // key function.
-
 protected:
   Expr(StmtClass SC, QualType T, ExprValueKind VK, ExprObjectKind OK,
        bool TD, bool VD, bool ContainsUnexpandedParameterPack) : Stmt(SC) {
@@ -138,14 +136,9 @@ public:
     ExprBits.ContainsUnexpandedParameterPack = PP;
   }
 
-  /// 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.
-  virtual SourceRange getSourceRange() const = 0;
-
   /// getExprLoc - Return the preferred location for the arrow when diagnosing
   /// a problem with a generic expression.
-  virtual SourceLocation getExprLoc() const { return getLocStart(); }
+  SourceLocation getExprLoc() const;
 
   /// isUnusedResultAWarning - Return true if this immediate expression should
   /// be warned about if the result is unused.  If so, fill in Loc and Ranges
@@ -682,7 +675,7 @@ public:
 
   SourceLocation getLocation() const { return Loc; }
   void setLocation(SourceLocation L) { Loc = L; }
-  virtual SourceRange getSourceRange() const;
+  SourceRange getSourceRange() const;
 
   /// \brief Determine whether this declaration reference was preceded by a
   /// C++ nested-name-specifier, e.g., \c N::foo.
@@ -786,8 +779,7 @@ public:
   static bool classof(const DeclRefExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
   
   friend class ASTStmtReader;
   friend class ASTStmtWriter;
@@ -827,7 +819,7 @@ public:
 
   static std::string ComputeName(IdentType IT, const Decl *CurrentDecl);
 
-  virtual SourceRange getSourceRange() const { return SourceRange(Loc); }
+  SourceRange getSourceRange() const { return SourceRange(Loc); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == PredefinedExprClass;
@@ -835,8 +827,7 @@ public:
   static bool classof(const PredefinedExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 /// \brief Used by IntegerLiteral/FloatingLiteral to store the numeric without
@@ -913,7 +904,7 @@ public:
   static IntegerLiteral *Create(ASTContext &C, EmptyShell Empty);
 
   llvm::APInt getValue() const { return Num.getValue(); }
-  virtual SourceRange getSourceRange() const { return SourceRange(Loc); }
+  SourceRange getSourceRange() const { return SourceRange(Loc); }
 
   /// \brief Retrieve the location of the literal.
   SourceLocation getLocation() const { return Loc; }
@@ -927,8 +918,7 @@ public:
   static bool classof(const IntegerLiteral *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 class CharacterLiteral : public Expr {
@@ -949,7 +939,7 @@ public:
   SourceLocation getLocation() const { return Loc; }
   bool isWide() const { return IsWide; }
 
-  virtual SourceRange getSourceRange() const { return SourceRange(Loc); }
+  SourceRange getSourceRange() const { return SourceRange(Loc); }
 
   unsigned getValue() const { return Value; }
 
@@ -963,8 +953,7 @@ public:
   static bool classof(const CharacterLiteral *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 class FloatingLiteral : public Expr {
@@ -1005,7 +994,7 @@ public:
   SourceLocation getLocation() const { return Loc; }
   void setLocation(SourceLocation L) { Loc = L; }
 
-  virtual SourceRange getSourceRange() const { return SourceRange(Loc); }
+  SourceRange getSourceRange() const { return SourceRange(Loc); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == FloatingLiteralClass;
@@ -1013,8 +1002,7 @@ public:
   static bool classof(const FloatingLiteral *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 /// ImaginaryLiteral - We support imaginary integer and floating point literals,
@@ -1038,15 +1026,14 @@ public:
   Expr *getSubExpr() { return cast<Expr>(Val); }
   void setSubExpr(Expr *E) { Val = E; }
 
-  virtual SourceRange getSourceRange() const { return Val->getSourceRange(); }
+  SourceRange getSourceRange() const { return Val->getSourceRange(); }
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == ImaginaryLiteralClass;
   }
   static bool classof(const ImaginaryLiteral *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&Val, &Val+1); }
 };
 
 /// StringLiteral - This represents a string literal expression, e.g. "foo"
@@ -1139,7 +1126,7 @@ public:
   tokloc_iterator tokloc_begin() const { return TokLocs; }
   tokloc_iterator tokloc_end() const { return TokLocs+NumConcatenated; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(TokLocs[0], TokLocs[NumConcatenated-1]);
   }
   static bool classof(const Stmt *T) {
@@ -1148,8 +1135,7 @@ public:
   static bool classof(const StringLiteral *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 /// ParenExpr - This represents a parethesized expression, e.g. "(1)".  This
@@ -1173,7 +1159,7 @@ public:
   Expr *getSubExpr() { return cast<Expr>(Val); }
   void setSubExpr(Expr *E) { Val = E; }
 
-  virtual SourceRange getSourceRange() const { return SourceRange(L, R); }
+  SourceRange getSourceRange() const { return SourceRange(L, R); }
 
   /// \brief Get the location of the left parentheses '('.
   SourceLocation getLParen() const { return L; }
@@ -1189,8 +1175,7 @@ public:
   static bool classof(const ParenExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&Val, &Val+1); }
 };
 
 
@@ -1271,13 +1256,13 @@ public:
   /// the given unary opcode.
   static OverloadedOperatorKind getOverloadedOperator(Opcode Opc);
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     if (isPostfix())
       return SourceRange(Val->getLocStart(), Loc);
     else
       return SourceRange(Loc, Val->getLocEnd());
   }
-  virtual SourceLocation getExprLoc() const { return Loc; }
+  SourceLocation getExprLoc() const { return Loc; }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == UnaryOperatorClass;
@@ -1285,8 +1270,7 @@ public:
   static bool classof(const UnaryOperator *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&Val, &Val+1); }
 };
 
 /// OffsetOfExpr - [C99 7.17] - This represents an expression of the form
@@ -1473,7 +1457,7 @@ public:
     return NumExprs;
   }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(OperatorLoc, RParenLoc);
   }
 
@@ -1484,8 +1468,12 @@ public:
   static bool classof(const OffsetOfExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    Stmt **begin =
+      reinterpret_cast<Stmt**>(reinterpret_cast<OffsetOfNode*>(this + 1)
+                               + NumComps);
+    return child_range(begin, begin + NumExprs);
+  }
 };
 
 /// SizeOfAlignOfExpr - [C99 6.5.3.4] - This is for sizeof/alignof, both of
@@ -1565,7 +1553,7 @@ public:
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation L) { RParenLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(OpLoc, RParenLoc);
   }
 
@@ -1575,8 +1563,7 @@ public:
   static bool classof(const SizeOfAlignOfExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children();
 };
 
 //===----------------------------------------------------------------------===//
@@ -1639,14 +1626,14 @@ public:
     return cast<Expr>(getRHS()->getType()->isIntegerType() ? getRHS():getLHS());
   }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(getLHS()->getLocStart(), RBracketLoc);
   }
 
   SourceLocation getRBracketLoc() const { return RBracketLoc; }
   void setRBracketLoc(SourceLocation L) { RBracketLoc = L; }
 
-  virtual SourceLocation getExprLoc() const { return getBase()->getExprLoc(); }
+  SourceLocation getExprLoc() const { return getBase()->getExprLoc(); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == ArraySubscriptExprClass;
@@ -1654,8 +1641,9 @@ public:
   static bool classof(const ArraySubscriptExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
+  }
 };
 
 
@@ -1775,7 +1763,7 @@ public:
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation L) { RParenLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(getCallee()->getLocStart(), RParenLoc);
   }
 
@@ -1786,8 +1774,10 @@ public:
   static bool classof(const CallExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&SubExprs[0],
+                       &SubExprs[0]+NumArgs+getNumPreArgs()+PREARGS_START);
+  }
 };
 
 /// MemberExpr - [C99 6.5.2.3] Structure and Union Members.  X->F and X.F.
@@ -2007,7 +1997,7 @@ public:
   SourceLocation getMemberLoc() const { return MemberLoc; }
   void setMemberLoc(SourceLocation L) { MemberLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     // If we have an implicit base (like a C++ implicit this),
     // make sure not to return its location
     SourceLocation EndLoc = (HasExplicitTemplateArgumentList)
@@ -2019,7 +2009,7 @@ public:
     return SourceRange(BaseLoc, EndLoc);
   }
 
-  virtual SourceLocation getExprLoc() const { return MemberLoc; }
+  SourceLocation getExprLoc() const { return MemberLoc; }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == MemberExprClass;
@@ -2027,8 +2017,7 @@ public:
   static bool classof(const MemberExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&Base, &Base+1); }
 
   friend class ASTReader;
   friend class ASTStmtWriter;
@@ -2073,7 +2062,7 @@ public:
   TypeSourceInfo *getTypeSourceInfo() const { return TInfo; }
   void setTypeSourceInfo(TypeSourceInfo* tinfo) { TInfo = tinfo; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     // FIXME: Init should never be null.
     if (!Init)
       return SourceRange();
@@ -2088,8 +2077,7 @@ public:
   static bool classof(const CompoundLiteralExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&Init, &Init+1); }
 };
 
 /// CastExpr - Base class for type casts, including both implicit
@@ -2228,8 +2216,7 @@ public:
   static bool classof(const CastExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&Op, &Op+1); }
 };
 
 /// ImplicitCastExpr - Allows us to explicitly represent implicit type
@@ -2277,7 +2264,7 @@ public:
 
   static ImplicitCastExpr *CreateEmpty(ASTContext &Context, unsigned PathSize);
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return getSubExpr()->getSourceRange();
   }
 
@@ -2367,7 +2354,7 @@ public:
   SourceLocation getRParenLoc() const { return RPLoc; }
   void setRParenLoc(SourceLocation L) { RPLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(LPLoc, getSubExpr()->getSourceRange().getEnd());
   }
   static bool classof(const Stmt *T) {
@@ -2436,7 +2423,7 @@ public:
   Expr *getRHS() const { return cast<Expr>(SubExprs[RHS]); }
   void setRHS(Expr *E) { SubExprs[RHS] = E; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(getLHS()->getLocStart(), getRHS()->getLocEnd());
   }
 
@@ -2503,8 +2490,9 @@ public:
   static bool classof(const BinaryOperator *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
+  }
 
 protected:
   BinaryOperator(Expr *lhs, Expr *rhs, Opcode opc, QualType ResTy,
@@ -2636,7 +2624,7 @@ public:
   SourceLocation getColonLoc() const { return ColonLoc; }
   void setColonLoc(SourceLocation L) { ColonLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(getCond()->getLocStart(), getRHS()->getLocEnd());
   }
   static bool classof(const Stmt *T) {
@@ -2645,8 +2633,9 @@ public:
   static bool classof(const ConditionalOperator *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
+  }
 };
 
 /// AddrLabelExpr - The GNU address of label extension, representing &&label.
@@ -2668,7 +2657,7 @@ public:
   SourceLocation getLabelLoc() const { return LabelLoc; }
   void setLabelLoc(SourceLocation L) { LabelLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(AmpAmpLoc, LabelLoc);
   }
 
@@ -2681,8 +2670,7 @@ public:
   static bool classof(const AddrLabelExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 /// StmtExpr - This is the GNU Statement Expression extension: ({int X=4; X;}).
@@ -2709,7 +2697,7 @@ public:
   const CompoundStmt *getSubStmt() const { return cast<CompoundStmt>(SubStmt); }
   void setSubStmt(CompoundStmt *S) { SubStmt = S; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(LParenLoc, RParenLoc);
   }
 
@@ -2724,8 +2712,7 @@ public:
   static bool classof(const StmtExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&SubStmt, &SubStmt+1); }
 };
 
 
@@ -2760,7 +2747,7 @@ public:
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation L) { RParenLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(BuiltinLoc, RParenLoc);
   }
   static bool classof(const Stmt *T) {
@@ -2794,8 +2781,9 @@ public:
   }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&SubExprs[0], &SubExprs[0]+NumExprs);
+  }
 };
 
 /// ChooseExpr - GNU builtin-in function __builtin_choose_expr.
@@ -2851,7 +2839,7 @@ public:
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation L) { RParenLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(BuiltinLoc, RParenLoc);
   }
   static bool classof(const Stmt *T) {
@@ -2860,8 +2848,9 @@ public:
   static bool classof(const ChooseExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
+  }
 };
 
 /// GNUNullExpr - Implements the GNU __null extension, which is a name
@@ -2886,7 +2875,7 @@ public:
   SourceLocation getTokenLocation() const { return TokenLoc; }
   void setTokenLocation(SourceLocation L) { TokenLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(TokenLoc);
   }
   static bool classof(const Stmt *T) {
@@ -2895,8 +2884,7 @@ public:
   static bool classof(const GNUNullExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 /// VAArgExpr, used for the builtin function __builtin_va_arg.
@@ -2931,7 +2919,7 @@ public:
   SourceLocation getRParenLoc() const { return RParenLoc; }
   void setRParenLoc(SourceLocation L) { RParenLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(BuiltinLoc, RParenLoc);
   }
   static bool classof(const Stmt *T) {
@@ -2940,8 +2928,7 @@ public:
   static bool classof(const VAArgExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&Val, &Val+1); }
 };
 
 /// @brief Describes an C or C++ initializer list.
@@ -3080,7 +3067,7 @@ public:
     HadArrayRangeDesignator = ARD;
   }
 
-  virtual SourceRange getSourceRange() const;
+  SourceRange getSourceRange() const;
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == InitListExprClass;
@@ -3088,8 +3075,10 @@ public:
   static bool classof(const InitListExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    if (InitExprs.empty()) return child_range();
+    return child_range(&InitExprs[0], &InitExprs[0] + InitExprs.size());
+  }
 
   typedef InitExprsTy::iterator iterator;
   typedef InitExprsTy::const_iterator const_iterator;
@@ -3390,7 +3379,7 @@ public:
   void ExpandDesignator(ASTContext &C, unsigned Idx, const Designator *First,
                         const Designator *Last);
 
-  virtual SourceRange getSourceRange() const;
+  SourceRange getSourceRange() const;
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == DesignatedInitExprClass;
@@ -3398,8 +3387,10 @@ public:
   static bool classof(const DesignatedInitExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    Stmt **begin = reinterpret_cast<Stmt**>(this + 1);
+    return child_range(begin, begin + NumSubExprs);
+  }
 };
 
 /// \brief Represents an implicitly-generated value initialization of
@@ -3425,13 +3416,12 @@ public:
   }
   static bool classof(const ImplicitValueInitExpr *) { return true; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange();
   }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 
@@ -3464,7 +3454,7 @@ public:
   SourceLocation getLParenLoc() const { return LParenLoc; }
   SourceLocation getRParenLoc() const { return RParenLoc; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(LParenLoc, RParenLoc);
   }
   static bool classof(const Stmt *T) {
@@ -3473,8 +3463,9 @@ public:
   static bool classof(const ParenListExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&Exprs[0], &Exprs[0]+NumExprs);
+  }
 
   friend class ASTStmtReader;
   friend class ASTStmtWriter;
@@ -3531,7 +3522,7 @@ public:
   /// aggregate Constant of ConstantInt(s).
   void getEncodedElementAccess(llvm::SmallVectorImpl<unsigned> &Elts) const;
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(getBase()->getLocStart(), AccessorLoc);
   }
 
@@ -3545,8 +3536,7 @@ public:
   static bool classof(const ExtVectorElementExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&Base, &Base+1); }
 };
 
 
@@ -3573,7 +3563,7 @@ public:
   const Stmt *getBody() const;
   Stmt *getBody();
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(getCaretLocation(), getBody()->getLocEnd());
   }
 
@@ -3586,8 +3576,7 @@ public:
   static bool classof(const BlockExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 /// BlockDeclRefExpr - A reference to a local variable declared in an
@@ -3613,7 +3602,7 @@ public:
   SourceLocation getLocation() const { return Loc; }
   void setLocation(SourceLocation L) { Loc = L; }
 
-  virtual SourceRange getSourceRange() const { return SourceRange(Loc); }
+  SourceRange getSourceRange() const { return SourceRange(Loc); }
 
   bool isByRef() const { return IsByRef; }
   void setByRef(bool BR) { IsByRef = BR; }
@@ -3627,8 +3616,7 @@ public:
   static bool classof(const BlockDeclRefExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 /// OpaqueValueExpr - An expression referring to an opaque object of a
@@ -3654,9 +3642,8 @@ public:
   /// \brief Retrieve the location of this expression.
   SourceLocation getLocation() const { return Loc; }
   
-  virtual SourceRange getSourceRange() const;
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  SourceRange getSourceRange() const { return Loc; }
+  child_range children() { return child_range(); }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == OpaqueValueExprClass;
diff --git a/include/clang/AST/ExprCXX.h b/include/clang/AST/ExprCXX.h
index c0e35e3c89..719001aec6 100644
--- a/include/clang/AST/ExprCXX.h
+++ b/include/clang/AST/ExprCXX.h
@@ -71,7 +71,7 @@ public:
   /// bracket.
   SourceLocation getOperatorLoc() const { return getRParenLoc(); }
 
-  virtual SourceRange getSourceRange() const;
+  SourceRange getSourceRange() const;
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CXXOperatorCallExprClass;
@@ -108,7 +108,7 @@ public:
   /// FIXME: Returns 0 for member pointer call exprs.
   CXXRecordDecl *getRecordDecl();
 
-  virtual SourceRange getSourceRange() const;
+  SourceRange getSourceRange() const;
   
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == CXXMemberCallExprClass;
@@ -151,7 +151,7 @@ public:
   /// \brief Retrieve the location of the closing parenthesis.
   SourceLocation getRParenLoc() const { return RParenLoc; }
   
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     return SourceRange(Loc, RParenLoc);
   }
   static bool classof(const Stmt *T) {
@@ -306,7 +306,7 @@ public:
   bool getValue() const { return Value; }
   void setValue(bool V) { Value = V; }
 
-  virtual SourceRange getSourceRange() const { return SourceRange(Loc); }
+  SourceRange getSourceRange() const { return SourceRange(Loc); }
 
   SourceLocation getLocation() const { return Loc; }
   void setLocation(SourceLocation L) { Loc = L; }
@@ -317,8 +317,7 @@ public:
   static bool classof(const CXXBoolLiteralExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 /// CXXNullPtrLiteralExpr - [C++0x 2.14.7] C++ Pointer Literal
@@ -333,7 +332,7 @@ public:
   explicit CXXNullPtrLiteralExpr(EmptyShell Empty)
     : Expr(CXXNullPtrLiteralExprClass, Empty) { }
 
-  virtual SourceRange getSourceRange() const { return SourceRange(Loc); }
+  SourceRange getSourceRange() const { return SourceRange(Loc); }
 
   SourceLocation getLocation() const { return Loc; }
   void setLocation(SourceLocation L) { Loc = L; }
@@ -343,8 +342,7 @@ public:
   }
   static bool classof(const CXXNullPtrLiteralExpr *) { return true; }
 
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 /// CXXTypeidExpr - A C++ @c typeid expression (C++ [expr.typeid]), which gets
@@ -411,7 +409,7 @@ public:
     Operand = E;
   }
   
-  virtual SourceRange getSourceRange() const { return Range; }
+  SourceRange getSourceRange() const { return Range; }
   void setSourceRange(SourceRange R) { Range = R; }
   
   static bool classof(const Stmt *T) {
@@ -420,8 +418,11 @@ public:
   static bool classof(const CXXTypeidExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    if (isTypeOperand()) return child_range();
+    Stmt **begin = reinterpret_cast<Stmt**>(&Operand);
+    return child_range(begin, begin + 1);
+  }
 };
 
 /// CXXUuidofExpr - A microsoft C++ @c __uuidof expression, which gets
@@ -481,7 +482,7 @@ public:
     Operand = E;
   }
 
-  virtual SourceRange getSourceRange() const { return Range; }
+  SourceRange getSourceRange() const { return Range; }
   void setSourceRange(SourceRange R) { Range = R; }
   
   static bool classof(const Stmt *T) {
@@ -490,8 +491,11 @@ public:
   static bool classof(const CXXUuidofExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    if (isTypeOperand()) return child_range();
+    Stmt **begin = reinterpret_cast<Stmt**>(&Operand);
+    return child_range(begin, begin + 1);
+  }
 };
 
 /// CXXThisExpr - Represents the "this" expression in C++, which is a
@@ -523,7 +527,7 @@ public:
   SourceLocation getLocation() const { return Loc; }
   void setLocation(SourceLocation L) { Loc = L; }
 
-  virtual SourceRange getSourceRange() const { return SourceRange(Loc); }
+  SourceRange getSourceRange() const { return SourceRange(Loc); }
 
   bool isImplicit() const { return Implicit; }
   void setImplicit(bool I) { Implicit = I; }
@@ -534,8 +538,7 @@ public:
   static bool classof(const CXXThisExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 };
 
 ///  CXXThrowExpr - [C++ 15] C++ Throw Expression.  This handles
@@ -562,7 +565,7 @@ public:
   SourceLocation getThrowLoc() const { return ThrowLoc; }
   void setThrowLoc(SourceLocation L) { ThrowLoc = L; }
 
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     if (getSubExpr() == 0)
       return SourceRange(ThrowLoc, ThrowLoc);
     return SourceRange(ThrowLoc, getSubExpr()->getSourceRange().getEnd());
@@ -574,8 +577,9 @@ public:
   static bool classof(const CXXThrowExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() {
+    return child_range(&Op, Op ? &Op+1 : &Op);
+  }
 };
 
 /// CXXDefaultArgExpr - C++ [dcl.fct.default]. This wraps up a
@@ -649,7 +653,7 @@ public:
   /// used.
   SourceLocation getUsedLocation() const { return Loc; }
   
-  virtual SourceRange getSourceRange() const {
+  SourceRange getSourceRange() const {
     // Default argument expressions have no representation in the
     // source, so they have an empty source range.
     return SourceRange();
@@ -661,8 +665,7 @@ public:
   static bool classof(const CXXDefaultArgExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(); }
 
   friend class ASTStmtReader;
   friend class ASTStmtWriter;
@@ -724,7 +727,7 @@ public:
   Expr *getSubExpr() { return cast<Expr>(SubExpr); }
   void setSubExpr(Expr *E) { SubExpr = E; }
 
-  virtual SourceRange getSourceRange() const { 
+  SourceRange getSourceRange() const { 
     return SubExpr->getSourceRange();
   }
 
@@ -735,8 +738,7 @@ public:
   static bool classof(const CXXBindTemporaryExpr *) { return true; }
 
   // Iterators
-  virtual child_iterator child_begin();
-  virtual child_iterator child_end();
+  child_range children() { return child_range(&SubExpr, &SubExpr + 1); }
 };
 
 /// CXXConstructExpr - Represents a call to a C++ constructor.
@@ -842,7 +844,7 @@ public:
     Args[Arg] = ArgExpr;
   }
 
-  virtual SourceRange getSourceRange() const;
+  SourceRange getSourceRange() const;
   SourceRange getParenRange() const { return ParenRange; }
 
   static bool classof(const Stmt *T) {