diff --git a/llvm/include/llvm/ADT/ArrayRef.h b/llvm/include/llvm/ADT/ArrayRef.h
--- a/llvm/include/llvm/ADT/ArrayRef.h
+++ b/llvm/include/llvm/ADT/ArrayRef.h
@@ -97,9 +97,19 @@
     /*implicit*/ constexpr ArrayRef(const T (&Arr)[N]) : Data(Arr), Length(N) {}
 
     /// Construct an ArrayRef from a std::initializer_list.
+#if __GNUC__ >= 9
+// Disable gcc's warning in this constructor as it generates an enormous amount
+// of messages. Anyone using ArrayRef should already be aware of the fact that
+// it does not do lifetime extension.
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winit-list-lifetime"
+#endif
     /*implicit*/ ArrayRef(const std::initializer_list<T> &Vec)
     : Data(Vec.begin() == Vec.end() ? (T*)nullptr : Vec.begin()),
       Length(Vec.size()) {}
+#if __GNUC__ >= 9
+#pragma GCC diagnostic pop
+#endif
 
     /// Construct an ArrayRef<const T*> from ArrayRef<T*>. This uses SFINAE to
     /// ensure that only ArrayRefs of pointers can be converted.