Index: lib/Sema/SemaType.cpp
===================================================================
--- lib/Sema/SemaType.cpp
+++ lib/Sema/SemaType.cpp
@@ -2228,6 +2228,8 @@
             << ConstVal.toString(10) << ArraySize->getSourceRange();
         return QualType();
       }
+
+      CheckForIntOverflow(ArraySize);
     }
 
     T = Context.getConstantArrayType(T, ConstVal, ASM, Quals);
Index: test/Sema/integer-overflow.c
===================================================================
--- test/Sema/integer-overflow.c
+++ test/Sema/integer-overflow.c
@@ -172,6 +172,9 @@
 // expected-warning@+1 {{overflow in expression; result is 536870912 with type 'int'}}
   (void)f2(0, f0(4608 * 1024 * 1024));
 }
+void check_integer_overflows_in_array_size() {
+  int arr[4608 * 1024 * 1024]; // expected-warning {{overflow in expression; result is 536870912 with type 'int'}}
+}
 
 struct s {
   unsigned x;