Index: include/clang/AST/Expr.h
===================================================================
--- include/clang/AST/Expr.h
+++ include/clang/AST/Expr.h
@@ -908,6 +908,10 @@
     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
@@ -1168,6 +1172,10 @@
     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;
@@ -1223,6 +1231,9 @@
 
   // 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;
 };
@@ -1316,6 +1327,9 @@
   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 {
@@ -1366,6 +1380,9 @@
   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 {
@@ -1430,6 +1447,9 @@
   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,
@@ -1462,6 +1482,9 @@
 
   // 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"
@@ -1629,6 +1652,9 @@
   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
@@ -1670,6 +1696,9 @@
 
   // 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
@@ -1779,6 +1808,9 @@
 
   // 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.
@@ -1982,6 +2014,11 @@
     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;
 };
 
@@ -2070,6 +2107,7 @@
 
   // Iterators
   child_range children();
+  const_child_range children() const;
 };
 
 //===----------------------------------------------------------------------===//
@@ -2154,6 +2192,9 @@
   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]).
@@ -2314,6 +2355,11 @@
     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.
@@ -2568,6 +2614,9 @@
 
   // 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;
@@ -2640,6 +2689,9 @@
 
   // 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
@@ -2726,6 +2778,7 @@
 
   // 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
@@ -3069,6 +3122,9 @@
   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.
@@ -3249,6 +3305,9 @@
   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
@@ -3334,6 +3393,9 @@
   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 {
@@ -3388,6 +3450,9 @@
   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;}).
@@ -3430,6 +3495,9 @@
 
   // 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
@@ -3498,6 +3566,9 @@
   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
@@ -3552,6 +3623,9 @@
 
   // 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.
@@ -3632,6 +3706,9 @@
   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
@@ -3668,6 +3745,9 @@
   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.
@@ -3715,6 +3795,9 @@
 
   // 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.
@@ -3939,10 +4022,16 @@
 
   // Iterators
   child_range children() {
+    const_child_range CCR = const_cast<const InitListExpr *>(this)->children();
+    return child_range(cast_away_const(CCR.begin()),
+                       cast_away_const(CCR.end()));
+  }
+
+  const_child_range children() const {
     // FIXME: This does not include the array filler expression.
     if (InitExprs.empty())
-      return child_range(child_iterator(), child_iterator());
-    return child_range(&InitExprs[0], &InitExprs[0] + InitExprs.size());
+      return const_child_range(const_child_iterator(), const_child_iterator());
+    return const_child_range(&InitExprs[0], &InitExprs[0] + InitExprs.size());
   }
 
   typedef InitExprsTy::iterator iterator;
@@ -4257,6 +4346,10 @@
     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;
 };
@@ -4290,6 +4383,9 @@
   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:
@@ -4335,6 +4431,10 @@
   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.
@@ -4396,6 +4496,9 @@
   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;
@@ -4424,6 +4527,9 @@
   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;
@@ -4458,6 +4564,9 @@
   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 {
@@ -4504,6 +4613,9 @@
   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;
@@ -4624,7 +4736,9 @@
   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;
 };
 
@@ -4693,6 +4807,9 @@
 
   // 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.
@@ -4734,6 +4851,9 @@
   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]
@@ -4779,6 +4899,9 @@
 
   // 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
@@ -4917,9 +5040,16 @@
   }
 
   child_range children() {
-    Stmt **cs = reinterpret_cast<Stmt**>(getSubExprsBuffer());
-    return child_range(cs, cs + getNumSubExprs());
+    const_child_range CCR =
+        const_cast<const PseudoObjectExpr *>(this)->children();
+    return child_range(cast_away_const(CCR.begin()),
+                       cast_away_const(CCR.end()));
   }
+  const_child_range children() const {
+    Stmt *const *cs = const_cast<Stmt *const *>(
+        reinterpret_cast<const Stmt *const *>(getSubExprsBuffer()));
+    return const_child_range(cs, cs + getNumSubExprs());
+  }
 
   static bool classof(const Stmt *T) {
     return T->getStmtClass() == PseudoObjectExprClass;
@@ -5024,6 +5154,9 @@
   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
@@ -5042,6 +5175,10 @@
   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
@@ -128,6 +128,13 @@
 
   StmtIterator(const VariableArrayType *t)
     : StmtIteratorImpl<StmtIterator,Stmt*&>(t) {}
+
+private:
+  StmtIterator(const StmtIteratorBase &RHS)
+      : StmtIteratorImpl<StmtIterator, Stmt *&>(RHS) {}
+
+  inline friend StmtIterator
+  cast_away_const(const struct ConstStmtIterator &RHS);
 };
 
 struct ConstStmtIterator : public StmtIteratorImpl<ConstStmtIterator,
@@ -137,8 +144,15 @@
 
   ConstStmtIterator(const StmtIterator& RHS) :
     StmtIteratorImpl<ConstStmtIterator,const Stmt*>(RHS) {}
+
+  ConstStmtIterator(Stmt * const *S)
+      : StmtIteratorImpl<ConstStmtIterator, const Stmt *>(
+            const_cast<Stmt **>(S)) {}
 };
 
+inline StmtIterator cast_away_const(const ConstStmtIterator &RHS) {
+  return RHS;
+}
 } // end namespace clang
 
 #endif
Index: lib/AST/Expr.cpp
===================================================================
--- lib/AST/Expr.cpp
+++ lib/AST/Expr.cpp
@@ -2730,7 +2730,11 @@
   }
   case InitListExprClass: {
     const InitListExpr *ILE = cast<InitListExpr>(this);
-    if (ILE->getType()->isArrayType()) {
+    QualType UnderlyingType = ILE->getType();
+    if (UnderlyingType->isAtomicType())
+      UnderlyingType = UnderlyingType->castAs<AtomicType>()->getValueType();
+
+    if (UnderlyingType->isArrayType()) {
       unsigned numInits = ILE->getNumInits();
       for (unsigned i = 0; i < numInits; i++) {
         if (!ILE->getInit(i)->isConstantInitializer(Ctx, false, Culprit))
@@ -2739,9 +2743,9 @@
       return true;
     }
 
-    if (ILE->getType()->isRecordType()) {
+    if (UnderlyingType->isRecordType()) {
       unsigned ElementNo = 0;
-      RecordDecl *RD = ILE->getType()->getAs<RecordType>()->getDecl();
+      RecordDecl *RD = UnderlyingType->getAs<RecordType>()->getDecl();
       for (const auto *Field : RD->fields()) {
         // If this is a union, skip all the fields that aren't being initialized.
         if (RD->isUnion() && ILE->getInitializedFieldInUnion() != Field)
@@ -3887,16 +3891,22 @@
 
 // UnaryExprOrTypeTraitExpr
 Stmt::child_range UnaryExprOrTypeTraitExpr::children() {
+  const_child_range CCR =
+      const_cast<const UnaryExprOrTypeTraitExpr *>(this)->children();
+  return child_range(cast_away_const(CCR.begin()), cast_away_const(CCR.end()));
+}
+
+Stmt::const_child_range UnaryExprOrTypeTraitExpr::children() const {
   // If this is of a type and the type is a VLA type (and not a typedef), the
   // size expression of the VLA needs to be treated as an executable expression.
   // Why isn't this weirdness documented better in StmtIterator?
   if (isArgumentType()) {
-    if (const VariableArrayType* T = dyn_cast<VariableArrayType>(
-                                   getArgumentType().getTypePtr()))
-      return child_range(child_iterator(T), child_iterator());
-    return child_range(child_iterator(), child_iterator());
+    if (const VariableArrayType *T =
+            dyn_cast<VariableArrayType>(getArgumentType().getTypePtr()))
+      return const_child_range(const_child_iterator(T), const_child_iterator());
+    return const_child_range(const_child_iterator(), const_child_iterator());
   }
-  return child_range(&Argument.Ex, &Argument.Ex + 1);
+  return const_child_range(&Argument.Ex, &Argument.Ex + 1);
 }
 
 AtomicExpr::AtomicExpr(SourceLocation BLoc, ArrayRef<Expr*> args,