--- old/make/linux/makefiles/zeroshark.make	2019-08-21 19:00:41.028260322 +0100
+++ new/make/linux/makefiles/zeroshark.make	2019-08-21 19:00:40.872262714 +0100
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2003, 2005, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2003, 2015, Oracle and/or its affiliates. All rights reserved.
 # Copyright 2007, 2008 Red Hat, Inc.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
@@ -25,8 +25,16 @@
 
 # Setup common to Zero (non-Shark) and Shark versions of VM
 
-# override this from the main file because some version of llvm do not like -Wundef
-WARNING_FLAGS = -Wpointer-arith -Wsign-compare -Wunused-function -Wunused-value
+# Some versions of llvm do not like -Wundef
+ifeq ($(JVM_VARIANT_ZEROSHARK), true)
+  WARNING_FLAGS += -Wno-undef
+endif
+# Suppress some warning flags that are normally turned on for hotspot,
+# because some of the zero code has not been updated accordingly.
+WARNING_FLAGS += -Wno-return-type \
+  -Wno-format-nonliteral -Wno-format-security \
+  -Wno-maybe-uninitialized
+ 
 
 # If FDLIBM_CFLAGS is non-empty it holds CFLAGS needed to be passed to
 # the compiler so as to be able to produce optimized objects
@@ -48,5 +56,3 @@
 ifeq ($(ARCH_DATA_MODEL), 64)
   CFLAGS += -D_LP64=1
 endif
-
-OPT_CFLAGS/compactingPermGenGen.o = -O1