--- a/hotspot/make/bsd/makefiles/gcc.make	Mon Feb 08 18:54:09 2016 +0300
+++ b/hotspot/make/bsd/makefiles/gcc.make	Thu Dec 17 16:12:58 2015 +0300
@@ -256,7 +256,7 @@
 
 # Compiler warnings are treated as errors
 ifneq ($(COMPILER_WARNINGS_FATAL),false)
-  WARNINGS_ARE_ERRORS = -Werror
+  WARNINGS_ARE_ERRORS ?= -Werror
 endif
 
 ifeq ($(USE_CLANG), true)

--- a/hotspot/make/linux/makefiles/gcc.make	Mon Feb 08 18:54:09 2016 +0300
+++ b/hotspot/make/linux/makefiles/gcc.make	Thu Dec 17 16:12:58 2015 +0300
@@ -203,7 +203,7 @@
 endif
 
 # Compiler warnings are treated as errors
-WARNINGS_ARE_ERRORS = -Werror
+WARNINGS_ARE_ERRORS ?= -Werror
 
 ifeq ($(USE_CLANG), true)
   # However we need to clean the code up before we can unrestrictedly enable this option with Clang

--- a/hotspot/make/solaris/makefiles/adlc.make	Mon Feb 08 18:54:09 2016 +0300
+++ b/hotspot/make/solaris/makefiles/adlc.make	Thu Dec 17 16:12:58 2015 +0300
@@ -66,17 +66,21 @@
 CXXFLAGS += -DASSERT
 
 ifndef USE_GCC
-  # We need libCstd.so for adlc 
+  # We need libCstd.so for adlc
   CFLAGS += -library=Cstd -g
   LFLAGS += -library=Cstd -g
 endif
 
 # CFLAGS_WARN holds compiler options to suppress/enable warnings.
+CFLAGS_WARN = +w
 # Compiler warnings are treated as errors
 ifeq ($(shell expr $(COMPILER_REV_NUMERIC) \>= 509), 1)
-  CFLAGS_WARN = +w -errwarn
+  WARNINGS_ARE_ERRORS ?= -xwe
 endif
-# When using compiler version 5.13 (Solaris Studio 12.4), calls to explicitly 
+
+CFLAGS_WARN += $(WARNINGS_ARE_ERRORS)
+
+# When using compiler version 5.13 (Solaris Studio 12.4), calls to explicitly
 # instantiated template functions trigger this warning when +w is active.
 ifeq ($(shell expr $(COMPILER_REV_NUMERIC) \>= 513), 1)
   CFLAGS_WARN += -erroff=notemsource

--- a/hotspot/make/solaris/makefiles/gcc.make	Mon Feb 08 18:54:09 2016 +0300
+++ b/hotspot/make/solaris/makefiles/gcc.make	Thu Dec 17 16:12:58 2015 +0300
@@ -117,7 +117,7 @@
 
 
 # Compiler warnings are treated as errors
-WARNINGS_ARE_ERRORS = -Werror
+WARNINGS_ARE_ERRORS ?= -Werror
 
 # Enable these warnings. See 'info gcc' about details on these options
 WARNING_FLAGS = -Wpointer-arith -Wconversion -Wsign-compare -Wundef -Wformat=2

--- a/hotspot/make/solaris/makefiles/sparcWorks.make	Mon Feb 08 18:54:09 2016 +0300
+++ b/hotspot/make/solaris/makefiles/sparcWorks.make	Thu Dec 17 16:12:58 2015 +0300
@@ -145,7 +145,8 @@
 CFLAGS += -DDONT_USE_PRECOMPILED_HEADER
 
 # Compiler warnings are treated as errors
-CFLAGS_WARN = -xwe
+WARNINGS_ARE_ERRORS ?= -xwe
+CFLAGS_WARN = $(WARNINGS_ARE_ERRORS)
 
 ################################################
 # Begin current (>=5.9) Forte compiler options #