Index: include/clang/AST/Expr.h
===================================================================
--- include/clang/AST/Expr.h
+++ include/clang/AST/Expr.h
@@ -907,6 +907,10 @@
     return child_range(child_iterator(), child_iterator());
   }
 
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
+
   /// The source expression of an opaque value expression is the
   /// expression which originally generated the value.  This is
   /// provided as a convenience for analyses that don't wish to
@@ -1167,6 +1171,10 @@
     return child_range(child_iterator(), child_iterator());
   }
 
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
+
   friend TrailingObjects;
   friend class ASTStmtReader;
   friend class ASTStmtWriter;
@@ -1222,6 +1230,9 @@
 
   // Iterators
   child_range children() { return child_range(&FnName, &FnName + 1); }
+  const_child_range children() const {
+    return const_child_range(&FnName, &FnName + 1);
+  }
 
   friend class ASTStmtReader;
 };
@@ -1315,6 +1326,9 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 };
 
 class CharacterLiteral : public Expr {
@@ -1365,6 +1379,9 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 };
 
 class FloatingLiteral : public Expr, private APFloatStorage {
@@ -1429,6 +1446,9 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 };
 
 /// ImaginaryLiteral - We support imaginary integer and floating point literals,
@@ -1461,6 +1481,9 @@
 
   // Iterators
   child_range children() { return child_range(&Val, &Val+1); }
+  const_child_range children() const {
+    return const_child_range(&Val, &Val + 1);
+  }
 };
 
 /// StringLiteral - This represents a string literal expression, e.g. "foo"
@@ -1628,6 +1651,9 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 };
 
 /// ParenExpr - This represents a parethesized expression, e.g. "(1)".  This
@@ -1669,6 +1695,9 @@
 
   // Iterators
   child_range children() { return child_range(&Val, &Val+1); }
+  const_child_range children() const {
+    return const_child_range(&Val, &Val + 1);
+  }
 };
 
 /// UnaryOperator - This represents the unary-expression's (except sizeof and
@@ -1778,6 +1807,9 @@
 
   // Iterators
   child_range children() { return child_range(&Val, &Val+1); }
+  const_child_range children() const {
+    return const_child_range(&Val, &Val + 1);
+  }
 };
 
 /// Helper class for OffsetOfExpr.
@@ -1981,6 +2013,11 @@
     Stmt **begin = reinterpret_cast<Stmt **>(getTrailingObjects<Expr *>());
     return child_range(begin, begin + NumExprs);
   }
+  const_child_range children() const {
+    Stmt *const *begin =
+        reinterpret_cast<Stmt *const *>(getTrailingObjects<Expr *>());
+    return const_child_range(begin, begin + NumExprs);
+  }
   friend TrailingObjects;
 };
 
@@ -2069,6 +2106,7 @@
 
   // Iterators
   child_range children();
+  const_child_range children() const;
 };
 
 //===----------------------------------------------------------------------===//
@@ -2153,6 +2191,9 @@
   child_range children() {
     return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
   }
+  const_child_range children() const {
+    return const_child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
+  }
 };
 
 /// CallExpr - Represents a function call (C99 6.5.2.2, C++ [expr.call]).
@@ -2313,6 +2354,11 @@
     return child_range(&SubExprs[0],
                        &SubExprs[0]+NumArgs+getNumPreArgs()+PREARGS_START);
   }
+
+  const_child_range children() const {
+    return const_child_range(&SubExprs[0], &SubExprs[0] + NumArgs +
+                                               getNumPreArgs() + PREARGS_START);
+  }
 };
 
 /// Extra data stored in some MemberExpr objects.
@@ -2567,6 +2613,9 @@
 
   // Iterators
   child_range children() { return child_range(&Base, &Base+1); }
+  const_child_range children() const {
+    return const_child_range(&Base, &Base + 1);
+  }
 
   friend TrailingObjects;
   friend class ASTReader;
@@ -2639,6 +2688,9 @@
 
   // Iterators
   child_range children() { return child_range(&Init, &Init+1); }
+  const_child_range children() const {
+    return const_child_range(&Init, &Init + 1);
+  }
 };
 
 /// CastExpr - Base class for type casts, including both implicit
@@ -2725,6 +2777,7 @@
 
   // Iterators
   child_range children() { return child_range(&Op, &Op+1); }
+  const_child_range children() const { return const_child_range(&Op, &Op + 1); }
 };
 
 /// ImplicitCastExpr - Allows us to explicitly represent implicit type
@@ -3070,6 +3123,9 @@
   child_range children() {
     return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
   }
+  const_child_range children() const {
+    return const_child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
+  }
 
   // Set the FP contractability status of this operator. Only meaningful for
   // operations on floating point types.
@@ -3246,6 +3302,9 @@
   child_range children() {
     return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
   }
+  const_child_range children() const {
+    return const_child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
+  }
 };
 
 /// BinaryConditionalOperator - The GNU extension to the conditional
@@ -3331,6 +3390,9 @@
   child_range children() {
     return child_range(SubExprs, SubExprs + NUM_SUBEXPRS);
   }
+  const_child_range children() const {
+    return const_child_range(SubExprs, SubExprs + NUM_SUBEXPRS);
+  }
 };
 
 inline Expr *AbstractConditionalOperator::getCond() const {
@@ -3385,6 +3447,9 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 };
 
 /// StmtExpr - This is the GNU Statement Expression extension: ({int X=4; X;}).
@@ -3427,6 +3492,9 @@
 
   // Iterators
   child_range children() { return child_range(&SubStmt, &SubStmt+1); }
+  const_child_range children() const {
+    return const_child_range(&SubStmt, &SubStmt + 1);
+  }
 };
 
 /// ShuffleVectorExpr - clang-specific builtin-in function
@@ -3495,6 +3563,9 @@
   child_range children() {
     return child_range(&SubExprs[0], &SubExprs[0]+NumExprs);
   }
+  const_child_range children() const {
+    return const_child_range(&SubExprs[0], &SubExprs[0] + NumExprs);
+  }
 };
 
 /// ConvertVectorExpr - Clang builtin function __builtin_convertvector
@@ -3549,6 +3620,9 @@
 
   // Iterators
   child_range children() { return child_range(&SrcExpr, &SrcExpr+1); }
+  const_child_range children() const {
+    return const_child_range(&SrcExpr, &SrcExpr + 1);
+  }
 };
 
 /// ChooseExpr - GNU builtin-in function __builtin_choose_expr.
@@ -3629,6 +3703,9 @@
   child_range children() {
     return child_range(&SubExprs[0], &SubExprs[0]+END_EXPR);
   }
+  const_child_range children() const {
+    return const_child_range(&SubExprs[0], &SubExprs[0] + END_EXPR);
+  }
 };
 
 /// GNUNullExpr - Implements the GNU __null extension, which is a name
@@ -3665,6 +3742,9 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 };
 
 /// Represents a call to the builtin function \c __builtin_va_arg.
@@ -3712,6 +3792,9 @@
 
   // Iterators
   child_range children() { return child_range(&Val, &Val+1); }
+  const_child_range children() const {
+    return const_child_range(&Val, &Val + 1);
+  }
 };
 
 /// @brief Describes an C or C++ initializer list.
@@ -3942,6 +4025,11 @@
     return child_range(&InitExprs[0], &InitExprs[0] + InitExprs.size());
   }
 
+  const_child_range children() const {
+    auto Children = const_cast<InitListExpr *>(this)->children();
+    return const_child_range(Children.begin(), Children.end());
+  }
+
   typedef InitExprsTy::iterator iterator;
   typedef InitExprsTy::const_iterator const_iterator;
   typedef InitExprsTy::reverse_iterator reverse_iterator;
@@ -4254,6 +4342,10 @@
     Stmt **begin = getTrailingObjects<Stmt *>();
     return child_range(begin, begin + NumSubExprs);
   }
+  const_child_range children() const {
+    Stmt * const *begin = getTrailingObjects<Stmt *>();
+    return const_child_range(begin, begin + NumSubExprs);
+  }
 
   friend TrailingObjects;
 };
@@ -4287,6 +4379,9 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 };
 
 // In cases like:
@@ -4332,6 +4427,10 @@
   child_range children() {
     return child_range(&BaseAndUpdaterExprs[0], &BaseAndUpdaterExprs[0] + 2);
   }
+  const_child_range children() const {
+    return const_child_range(&BaseAndUpdaterExprs[0],
+                             &BaseAndUpdaterExprs[0] + 2);
+  }
 };
 
 /// \brief Represents a loop initializing the elements of an array.
@@ -4393,6 +4492,9 @@
   child_range children() {
     return child_range(SubExprs, SubExprs + 2);
   }
+  const_child_range children() const {
+    return const_child_range(SubExprs, SubExprs + 2);
+  }
 
   friend class ASTReader;
   friend class ASTStmtReader;
@@ -4421,6 +4523,9 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 
   friend class ASTReader;
   friend class ASTStmtReader;
@@ -4455,6 +4560,9 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 };
 
 class ParenListExpr : public Expr {
@@ -4501,6 +4609,9 @@
   child_range children() {
     return child_range(&Exprs[0], &Exprs[0]+NumExprs);
   }
+  const_child_range children() const {
+    return const_child_range(&Exprs[0], &Exprs[0] + NumExprs);
+  }
 
   friend class ASTStmtReader;
   friend class ASTStmtWriter;
@@ -4621,7 +4732,9 @@
   child_range children() {
     return child_range(SubExprs, SubExprs+END_EXPR+NumAssocs);
   }
-
+  const_child_range children() const {
+    return const_child_range(SubExprs, SubExprs + END_EXPR + NumAssocs);
+  }
   friend class ASTStmtReader;
 };
 
@@ -4690,6 +4803,9 @@
 
   // Iterators
   child_range children() { return child_range(&Base, &Base+1); }
+  const_child_range children() const {
+    return const_child_range(&Base, &Base + 1);
+  }
 };
 
 /// BlockExpr - Adaptor class for mixing a BlockDecl with expressions.
@@ -4731,6 +4847,9 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
 };
 
 /// AsTypeExpr - Clang builtin function __builtin_astype [OpenCL 6.2.4.2]
@@ -4776,6 +4895,9 @@
 
   // Iterators
   child_range children() { return child_range(&SrcExpr, &SrcExpr+1); }
+  const_child_range children() const {
+    return const_child_range(&SrcExpr, &SrcExpr + 1);
+  }
 };
 
 /// PseudoObjectExpr - An expression which accesses a pseudo-object
@@ -4917,6 +5039,10 @@
     Stmt **cs = reinterpret_cast<Stmt**>(getSubExprsBuffer());
     return child_range(cs, cs + getNumSubExprs());
   }
+  const_child_range children() const {
+    child_range R = const_cast<PseudoObjectExpr *>(this)->children();
+    return const_child_range(R.begin(), R.end());
+  }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == PseudoObjectExprClass;
@@ -5021,6 +5147,9 @@
   child_range children() {
     return child_range(SubExprs, SubExprs+NumSubExprs);
   }
+  const_child_range children() const {
+    return const_child_range(SubExprs, SubExprs + NumSubExprs);
+  }
 };
 
 /// TypoExpr - Internal placeholder for expressions where typo correction
@@ -5039,6 +5168,10 @@
   child_range children() {
     return child_range(child_iterator(), child_iterator());
   }
+  const_child_range children() const {
+    return const_child_range(const_child_iterator(), const_child_iterator());
+  }
+
   SourceLocation getLocStart() const LLVM_READONLY { return SourceLocation(); }
   SourceLocation getLocEnd() const LLVM_READONLY { return SourceLocation(); }
   
Index: include/clang/AST/StmtIterator.h
===================================================================
--- include/clang/AST/StmtIterator.h
+++ include/clang/AST/StmtIterator.h
@@ -137,6 +137,10 @@
 
   ConstStmtIterator(const StmtIterator& RHS) :
     StmtIteratorImpl<ConstStmtIterator,const Stmt*>(RHS) {}
+
+  ConstStmtIterator(Stmt * const *S)
+      : StmtIteratorImpl<ConstStmtIterator, const Stmt *>(
+            const_cast<Stmt **>(S)) {}
 };
 
 } // end namespace clang
Index: lib/AST/Expr.cpp
===================================================================
--- lib/AST/Expr.cpp
+++ lib/AST/Expr.cpp
@@ -3899,6 +3899,11 @@
   return child_range(&Argument.Ex, &Argument.Ex + 1);
 }
 
+Stmt::const_child_range UnaryExprOrTypeTraitExpr::children() const {
+  auto Children = const_cast<UnaryExprOrTypeTraitExpr *>(this)->children();
+  return const_child_range(Children.begin(), Children.end());
+}
+
 AtomicExpr::AtomicExpr(SourceLocation BLoc, ArrayRef<Expr*> args,
                        QualType t, AtomicOp op, SourceLocation RP)
   : Expr(AtomicExprClass, t, VK_RValue, OK_Ordinary,