Index: include/clang/Basic/DiagnosticParseKinds.td
===================================================================
--- include/clang/Basic/DiagnosticParseKinds.td
+++ include/clang/Basic/DiagnosticParseKinds.td
@@ -204,6 +204,9 @@
 def err_expected_semi_after_static_assert : Error<
   "expected ';' after static_assert">;
 def err_expected_semi_for : Error<"expected ';' in 'for' statement specifier">;
+def warn_single_decl_assign_in_for_range : Warning<
+  "range based for statement requires ':' after range declaration">,
+  InGroup<CXX11>;
 def warn_missing_selector_name : Warning<
   "%0 used as the name of the previous parameter rather than as part "
   "of the selector">,
Index: include/clang/Parse/Parser.h
===================================================================
--- include/clang/Parse/Parser.h
+++ include/clang/Parse/Parser.h
@@ -1722,11 +1722,15 @@
                                 bool AllowFunctionDefinitions,
                                 SourceLocation *DeclEnd = 0,
                                 ForRangeInit *FRI = 0);
-  Decl *ParseDeclarationAfterDeclarator(Declarator &D,
-               const ParsedTemplateInfo &TemplateInfo = ParsedTemplateInfo());
+  Decl *ParseDeclarationAfterDeclarator(
+      Declarator &D,
+      const ParsedTemplateInfo &TemplateInfo = ParsedTemplateInfo(),
+      bool IsFirstDeclInGroup = false);
   bool ParseAsmAttributesAfterDeclarator(Declarator &D);
-  Decl *ParseDeclarationAfterDeclaratorAndAttributes(Declarator &D,
-               const ParsedTemplateInfo &TemplateInfo = ParsedTemplateInfo());
+  Decl *ParseDeclarationAfterDeclaratorAndAttributes(
+      Declarator &D,
+      const ParsedTemplateInfo &TemplateInfo = ParsedTemplateInfo(),
+      bool IsFirstDeclInGroup = false);
   Decl *ParseFunctionStatementBody(Decl *Decl, ParseScope &BodyScope);
   Decl *ParseFunctionTryBlock(Decl *Decl, ParseScope &BodyScope);
 
Index: lib/Parse/ParseDecl.cpp
===================================================================
--- lib/Parse/ParseDecl.cpp
+++ lib/Parse/ParseDecl.cpp
@@ -1607,7 +1607,9 @@
   }
 
   SmallVector<Decl *, 8> DeclsInGroup;
-  Decl *FirstDecl = ParseDeclarationAfterDeclaratorAndAttributes(D);
+  Decl *FirstDecl =
+      ParseDeclarationAfterDeclaratorAndAttributes(D, ParsedTemplateInfo(),
+                                                   /*IsFirstDeclInGroup*/ true);
   if (LateParsedAttrs.size() > 0)
     ParseLexedAttributeList(LateParsedAttrs, FirstDecl, true, false);
   D.complete(FirstDecl);
@@ -1645,7 +1647,8 @@
 
     ParseDeclarator(D);
     if (!D.isInvalidType()) {
-      Decl *ThisDecl = ParseDeclarationAfterDeclarator(D);
+      Decl *ThisDecl = ParseDeclarationAfterDeclarator(D, ParsedTemplateInfo(),
+                                                       DeclsInGroup.empty());
       D.complete(ThisDecl);
       if (ThisDecl)
         DeclsInGroup.push_back(ThisDecl);
@@ -1713,16 +1716,20 @@
 /// According to the standard grammar, =default and =delete are function
 /// definitions, but that definitely doesn't fit with the parser here.
 ///
-Decl *Parser::ParseDeclarationAfterDeclarator(Declarator &D,
-                                     const ParsedTemplateInfo &TemplateInfo) {
+Decl *
+Parser::ParseDeclarationAfterDeclarator(Declarator &D,
+                                        const ParsedTemplateInfo &TemplateInfo,
+                                        bool IsFirstDeclInGroup) {
   if (ParseAsmAttributesAfterDeclarator(D))
     return 0;
 
-  return ParseDeclarationAfterDeclaratorAndAttributes(D, TemplateInfo);
+  return ParseDeclarationAfterDeclaratorAndAttributes(D, TemplateInfo,
+                                                      IsFirstDeclInGroup);
 }
 
-Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(Declarator &D,
-                                     const ParsedTemplateInfo &TemplateInfo) {
+Decl *Parser::ParseDeclarationAfterDeclaratorAndAttributes(
+    Declarator &D, const ParsedTemplateInfo &TemplateInfo,
+    bool IsFirstDeclInGroup) {
   // Inform the current actions module that we just parsed this declarator.
   Decl *ThisDecl = 0;
   switch (TemplateInfo.Kind) {
@@ -1787,7 +1794,7 @@
   // Parse declarator '=' initializer.
   // If a '==' or '+=' is found, suggest a fixit to '='.
   if (isTokenEqualOrEqualTypo()) {
-    ConsumeToken();
+    SourceLocation EqualLoc = ConsumeToken();
 
     if (Tok.is(tok::kw_delete)) {
       if (D.isFunctionDeclarator())
@@ -1816,6 +1823,16 @@
 
       ExprResult Init(ParseInitializer());
 
+      // If this is the only decl in (possibly) range based for statement, and
+      // it's initializing a variable with placeholder (auto) type, our best
+      // guess is that the user meant ':' instead of '='.
+      if (Tok.is(tok::r_paren) && getLangOpts().CPlusPlus11 &&
+          D.getContext() == Declarator::ForContext && TypeContainsAuto &&
+          IsFirstDeclInGroup) {
+        Diag(EqualLoc, diag::warn_single_decl_assign_in_for_range)
+            << FixItHint::CreateReplacement(EqualLoc, ":");
+      }
+
       if (getLangOpts().CPlusPlus && D.getCXXScopeSpec().isSet()) {
         Actions.ActOnCXXExitDeclInitializer(getCurScope(), ThisDecl);
         ExitScope();
Index: test/Parser/cxx0x-for-range.cpp
===================================================================
--- test/Parser/cxx0x-for-range.cpp
+++ test/Parser/cxx0x-for-range.cpp
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 %s
+// RUN: not %clang_cc1 -fsyntax-only -fdiagnostics-parseable-fixits -std=c++11 %s 2>&1 | FileCheck %s
 
 template<typename T, typename U>
 struct pair {};
@@ -28,3 +28,33 @@
 
   return n;
 }
+
+namespace PR19176 {
+struct Vector {
+  struct iterator {
+    int &operator*();
+    iterator &operator++();
+    iterator &operator++(int);
+    bool operator==(const iterator &) const;
+  };
+  iterator begin();
+  iterator end();
+};
+
+void f() {
+  Vector v;
+  int a[] = {1, 2, 3, 4};
+  for (auto foo   =     a) // expected-error {{expected ';' in 'for' statement specifier}}
+    // expected-warning@-1 {{range based for statement requires ':' after range declaration}}
+    // expected-error@-2 {{expected ';' in 'for' statement specifier}}
+    // CHECK: fix-it:"{{.*}}":{[[@LINE-3]]:19-[[@LINE-3]]:20}:":"
+    (void)foo;
+  for (auto i
+      =
+      v) // expected-error {{expected ';' in 'for' statement specifier}}
+    // expected-warning@-1 {{range based for statement requires ':' after range declaration}}
+    // expected-error@-2 {{expected ';' in 'for' statement specifier}}
+    // CHECK: fix-it:"{{.*}}":{[[@LINE-4]]:7-[[@LINE-4]]:8}:":"
+    (void)i;
+}
+}