Index: clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.cpp
===================================================================
--- clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.cpp
+++ clang-tools-extra/trunk/clang-tidy/modernize/LoopConvertCheck.cpp
@@ -112,8 +112,9 @@
 ///   - If the end iterator variable 'g' is defined, it is the same as 'f'.
 StatementMatcher makeIteratorLoopMatcher() {
   StatementMatcher BeginCallMatcher =
-      cxxMemberCallExpr(argumentCountIs(0),
-                        callee(cxxMethodDecl(hasName("begin"))))
+      cxxMemberCallExpr(
+          argumentCountIs(0),
+          callee(cxxMethodDecl(anyOf(hasName("begin"), hasName("cbegin")))))
           .bind(BeginCallName);
 
   DeclarationMatcher InitDeclMatcher =
@@ -127,7 +128,8 @@
       varDecl(hasInitializer(anything())).bind(EndVarName);
 
   StatementMatcher EndCallMatcher = cxxMemberCallExpr(
-      argumentCountIs(0), callee(cxxMethodDecl(hasName("end"))));
+      argumentCountIs(0),
+      callee(cxxMethodDecl(anyOf(hasName("end"), hasName("cend")))));
 
   StatementMatcher IteratorBoundMatcher =
       expr(anyOf(ignoringParenImpCasts(
@@ -296,7 +298,8 @@
     return nullptr;
   StringRef Name = Member->getMemberDecl()->getName();
   StringRef TargetName = IsBegin ? "begin" : "end";
-  if (Name != TargetName)
+  StringRef ConstTargetName = IsBegin ? "cbegin" : "cend";
+  if (Name != TargetName && Name != ConstTargetName)
     return nullptr;
 
   const Expr *SourceExpr = Member->getBase();
@@ -423,7 +426,7 @@
   Options.store(Opts, "MinConfidence", Confs[static_cast<int>(MinConfidence)]);
 
   SmallVector<std::string, 4> Styles{"camelBack", "CamelCase", "lower_case",
-                                    "UPPER_CASE"};
+                                     "UPPER_CASE"};
   Options.store(Opts, "NamingStyle", Styles[static_cast<int>(NamingStyle)]);
 }
 
Index: clang-tools-extra/trunk/test/clang-tidy/Inputs/modernize-loop-convert/structures.h
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/Inputs/modernize-loop-convert/structures.h
+++ clang-tools-extra/trunk/test/clang-tidy/Inputs/modernize-loop-convert/structures.h
@@ -16,11 +16,20 @@
   int X;
 };
 
+struct NonTriviallyCopyable {
+  NonTriviallyCopyable() = default;
+  // Define this constructor to make this class non-trivially copyable.
+  NonTriviallyCopyable(const NonTriviallyCopyable& Ntc);
+  int X;
+};
+
 struct S {
   typedef MutableVal *iterator;
   typedef const MutableVal *const_iterator;
   const_iterator begin() const;
   const_iterator end() const;
+  const_iterator cbegin() const;
+  const_iterator cend() const;
   iterator begin();
   iterator end();
 };
Index: clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-basic.cpp
===================================================================
--- clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-basic.cpp
+++ clang-tools-extra/trunk/test/clang-tidy/modernize-loop-convert-basic.cpp
@@ -104,6 +104,14 @@
   // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
   // CHECK-FIXES: for (auto Elem : ConstArr)
   // CHECK-FIXES-NEXT: printf("2 * %d = %d\n", Elem, Elem + Elem);
+
+  const NonTriviallyCopyable NonCopy[N]{};
+  for (int I = 0; I < N; ++I) {
+    printf("2 * %d = %d\n", NonCopy[I].X, NonCopy[I].X + NonCopy[I].X);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (const auto & Elem : NonCopy)
+  // CHECK-FIXES-NEXT: printf("2 * %d = %d\n", Elem.X, Elem.X + Elem.X);
 }
 
 struct HasArr {
@@ -209,6 +217,13 @@
   // CHECK-FIXES: for (auto & P : *Ps)
   // CHECK-FIXES-NEXT: printf("s has value %d\n", P.X);
 
+  for (S::const_iterator It = Ss.cbegin(), E = Ss.cend(); It != E; ++It) {
+    printf("s has value %d\n", (*It).X);
+  }
+  // CHECK-MESSAGES: :[[@LINE-3]]:3: warning: use range-based for loop instead
+  // CHECK-FIXES: for (auto Elem : Ss)
+  // CHECK-FIXES-NEXT: printf("s has value %d\n", Elem.X);
+
   for (S::iterator It = Ss.begin(), E = Ss.end(); It != E; ++It) {
     printf("s has value %d\n", It->X);
   }
@@ -459,8 +474,8 @@
 const int N = 6;
 dependent<int> V;
 dependent<int> *Pv;
-const dependent<int> Constv;
-const dependent<int> *Pconstv;
+const dependent<NonTriviallyCopyable> Constv;
+const dependent<NonTriviallyCopyable> *Pconstv;
 
 transparent<dependent<int>> Cv;
 
@@ -516,50 +531,51 @@
   // CHECK-FIXES-NEXT: Sum += Elem + 2;
 }
 
+// Ensure that 'const auto &' is used with containers of non-trivial types.
 void constness() {
   int Sum = 0;
   for (int I = 0, E = Constv.size(); I < E; ++I) {
-    printf("Fibonacci number is %d\n", Constv[I]);
-    Sum += Constv[I] + 2;
+    printf("Fibonacci number is %d\n", Constv[I].X);
+    Sum += Constv[I].X + 2;
   }
   // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
-  // CHECK-FIXES: for (auto Elem : Constv)
-  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", Elem);
-  // CHECK-FIXES-NEXT: Sum += Elem + 2;
+  // CHECK-FIXES: for (const auto & Elem : Constv)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", Elem.X);
+  // CHECK-FIXES-NEXT: Sum += Elem.X + 2;
 
   for (int I = 0, E = Constv.size(); I < E; ++I) {
-    printf("Fibonacci number is %d\n", Constv.at(I));
-    Sum += Constv.at(I) + 2;
+    printf("Fibonacci number is %d\n", Constv.at(I).X);
+    Sum += Constv.at(I).X + 2;
   }
   // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
-  // CHECK-FIXES: for (auto Elem : Constv)
-  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", Elem);
-  // CHECK-FIXES-NEXT: Sum += Elem + 2;
+  // CHECK-FIXES: for (const auto & Elem : Constv)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", Elem.X);
+  // CHECK-FIXES-NEXT: Sum += Elem.X + 2;
 
   for (int I = 0, E = Pconstv->size(); I < E; ++I) {
-    printf("Fibonacci number is %d\n", Pconstv->at(I));
-    Sum += Pconstv->at(I) + 2;
+    printf("Fibonacci number is %d\n", Pconstv->at(I).X);
+    Sum += Pconstv->at(I).X + 2;
   }
   // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
-  // CHECK-FIXES: for (auto Elem : *Pconstv)
-  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", Elem);
-  // CHECK-FIXES-NEXT: Sum += Elem + 2;
+  // CHECK-FIXES: for (const auto & Elem : *Pconstv)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", Elem.X);
+  // CHECK-FIXES-NEXT: Sum += Elem.X + 2;
 
   // This test will fail if size() isn't called repeatedly, since it
   // returns unsigned int, and 0 is deduced to be signed int.
   // FIXME: Insert the necessary explicit conversion, or write out the types
   // explicitly.
   for (int I = 0; I < Pconstv->size(); ++I) {
-    printf("Fibonacci number is %d\n", (*Pconstv).at(I));
-    Sum += (*Pconstv)[I] + 2;
+    printf("Fibonacci number is %d\n", (*Pconstv).at(I).X);
+    Sum += (*Pconstv)[I].X + 2;
   }
   // CHECK-MESSAGES: :[[@LINE-4]]:3: warning: use range-based for loop instead
-  // CHECK-FIXES: for (auto Elem : *Pconstv)
-  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", Elem);
-  // CHECK-FIXES-NEXT: Sum += Elem + 2;
+  // CHECK-FIXES: for (const auto & Elem : *Pconstv)
+  // CHECK-FIXES-NEXT: printf("Fibonacci number is %d\n", Elem.X);
+  // CHECK-FIXES-NEXT: Sum += Elem.X + 2;
 }
 
-void ConstRef(const dependent<int>& ConstVRef) {
+void constRef(const dependent<int>& ConstVRef) {
   int sum = 0;
   // FIXME: This does not work with size_t (probably due to the implementation
   // of dependent); make dependent work exactly like a std container type.