Index: include/clang/Basic/DiagnosticGroups.td
===================================================================
--- include/clang/Basic/DiagnosticGroups.td	(revision 173285)
+++ include/clang/Basic/DiagnosticGroups.td	(working copy)
@@ -317,6 +317,7 @@
 def VectorConversion : DiagGroup<"vector-conversion">;      // clang specific
 def VexingParse : DiagGroup<"vexing-parse">;
 def VLA : DiagGroup<"vla">;
+def VLAExtension : DiagGroup<"vla-extension">;
 def VolatileRegisterVar : DiagGroup<"volatile-register-var">;
 def Visibility : DiagGroup<"visibility">;
 def ZeroLengthArray : DiagGroup<"zero-length-array">;
@@ -473,7 +474,7 @@
 def C99 : DiagGroup<"c99-extensions">;
 
 // A warning group for warnings about GCC extensions.
-def GNU : DiagGroup<"gnu", [GNUDesignator, VLA, ZeroLengthArray]>;
+def GNU : DiagGroup<"gnu", [GNUDesignator, VLAExtension, ZeroLengthArray]>;
 // A warning group for warnings about code that clang accepts but gcc doesn't.
 def GccCompat : DiagGroup<"gcc-compat">;
 
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td	(revision 173285)
+++ include/clang/Basic/DiagnosticSemaKinds.td	(working copy)
@@ -75,7 +75,9 @@
 
 // C99 variable-length arrays
 def ext_vla : Extension<"variable length arrays are a C99 feature">,
-  InGroup<VLA>;
+  InGroup<VLAExtension>;
+def warn_vla_used : Warning<"variable length array used">,
+  InGroup<VLA>, DefaultIgnore;
 def err_vla_non_pod : Error<"variable length array of non-POD element type %0">;
 def err_vla_in_sfinae : Error<
   "variable length array cannot be formed during template argument deduction">;
Index: test/Sema/warn-vla.c
===================================================================
--- test/Sema/warn-vla.c	(revision 0)
+++ test/Sema/warn-vla.c	(working copy)
@@ -0,0 +1,12 @@
+// RUN: %clang_cc1 -std=c99 -fsyntax-only -verify -Wvla %s
+// RUN: %clang_cc1 -std=c89 -fsyntax-only -verify -Wvla %s
+
+void test1(int n) {
+  int v[n]; // expected-warning {{variable length array used}}
+}
+
+void test2(int n, int v[n]) { // expected-warning {{variable length array used}}
+}
+
+void test3(int n, int v[n]); // expected-warning {{variable length array used}}
+
Index: test/SemaCXX/c99-variable-length-array-cxx11.cpp
===================================================================
--- test/SemaCXX/c99-variable-length-array-cxx11.cpp	(revision 173285)
+++ test/SemaCXX/c99-variable-length-array-cxx11.cpp	(working copy)
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -Wvla %s
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++11 -Wvla-extension %s
 struct StillPOD {
   StillPOD() = default;
 };
Index: test/SemaCXX/c99-variable-length-array.cpp
===================================================================
--- test/SemaCXX/c99-variable-length-array.cpp	(revision 173285)
+++ test/SemaCXX/c99-variable-length-array.cpp	(working copy)
@@ -1,4 +1,4 @@
-// RUN: %clang_cc1 -fsyntax-only -verify -Wvla %s
+// RUN: %clang_cc1 -fsyntax-only -verify -Wvla-extension %s
 struct NonPOD {
   NonPOD();
 };
Index: test/SemaCXX/warn-vla.cpp
===================================================================
--- test/SemaCXX/warn-vla.cpp	(revision 0)
+++ test/SemaCXX/warn-vla.cpp	(working copy)
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -Wvla %s
+
+void test1(int n) {
+  int v[n]; // expected-warning {{variable length array used}}
+}
+
+void test2(int n, int v[n]) { // expected-warning {{variable length array used}}
+}
+
+void test3(int n, int v[n]); // expected-warning {{variable length array used}}
+
+template<typename T>
+void test4(int n) {
+  int v[n]; // expected-warning {{variable length array used}}
+}
+
+template<typename T>
+void test5(int n, int v[n]) { // expected-warning {{variable length array used}}
+}
+
+template<typename T>
+void test6(int n, int v[n]); // expected-warning {{variable length array used}}
+
+template<typename T>
+void test7(int n, T v[n]) { // expected-warning {{variable length array used}}
+}
+
Index: lib/Sema/SemaType.cpp
===================================================================
--- lib/Sema/SemaType.cpp	(revision 173285)
+++ lib/Sema/SemaType.cpp	(working copy)
@@ -1496,6 +1496,11 @@
                                      : diag::ext_c99_array_usage) << ASM;
   }
 
+  if (T->isVariableArrayType()) {
+    // Warn about VLAs for -Wvla.
+    Diag(Loc, diag::warn_vla_used);
+  }
+
   return T;
 }