--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/compiler/ImmutableOopMapSet.java	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/compiler/ImmutableOopMapSet.java	Wed Oct 21 16:38:48 2015 -0400
@@ -67,9 +67,6 @@
       }
     }
 
-    public void visitValueLocation(Address valueAddr) {
-    }
-
     public void visitNarrowOopLocation(Address narrowOopAddr) {
       addressVisitor.visitCompOopAddress(narrowOopAddr);
     }
@@ -216,9 +213,9 @@
       }
     }
 
-    // We want narow oop, value and oop oop_types
-    OopMapValue.OopTypes[] values = new OopMapValue.OopTypes[]{
-        OopMapValue.OopTypes.OOP_VALUE, OopMapValue.OopTypes.VALUE_VALUE, OopMapValue.OopTypes.NARROWOOP_VALUE
+    // We want narow oop and oop oop_types
+    OopMapValue.OopTypes[] values = new OopMapValue.OopTypes[] {
+        OopMapValue.OopTypes.OOP_VALUE, OopMapValue.OopTypes.NARROWOOP_VALUE
     };
 
     {
@@ -231,8 +228,6 @@
             // to detect in the debugging system
             // assert(Universe::is_heap_or_null(*loc), "found non oop pointer");
             visitor.visitOopLocation(loc);
-          } else if (omv.getType() == OopMapValue.OopTypes.VALUE_VALUE) {
-            visitor.visitValueLocation(loc);
           } else if (omv.getType() == OopMapValue.OopTypes.NARROWOOP_VALUE) {
             visitor.visitNarrowOopLocation(loc);
           }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/compiler/OopMapValue.java	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/compiler/OopMapValue.java	Wed Oct 21 16:38:48 2015 -0400
@@ -49,7 +49,6 @@
   // Types of OopValues
   static int UNUSED_VALUE;
   static int OOP_VALUE;
-  static int VALUE_VALUE;
   static int NARROWOOP_VALUE;
   static int CALLEE_SAVED_VALUE;
   static int DERIVED_OOP_VALUE;
@@ -73,7 +72,6 @@
     REGISTER_MASK_IN_PLACE = db.lookupIntConstant("OopMapValue::register_mask_in_place").intValue();
     UNUSED_VALUE           = db.lookupIntConstant("OopMapValue::unused_value").intValue();
     OOP_VALUE              = db.lookupIntConstant("OopMapValue::oop_value").intValue();
-    VALUE_VALUE            = db.lookupIntConstant("OopMapValue::value_value").intValue();
     NARROWOOP_VALUE        = db.lookupIntConstant("OopMapValue::narrowoop_value").intValue();
     CALLEE_SAVED_VALUE     = db.lookupIntConstant("OopMapValue::callee_saved_value").intValue();
     DERIVED_OOP_VALUE      = db.lookupIntConstant("OopMapValue::derived_oop_value").intValue();
@@ -82,7 +80,6 @@
   public static abstract class OopTypes {
     public static final OopTypes UNUSED_VALUE       = new OopTypes() { int getValue() { return OopMapValue.UNUSED_VALUE;       }};
     public static final OopTypes OOP_VALUE          = new OopTypes() { int getValue() { return OopMapValue.OOP_VALUE;          }};
-    public static final OopTypes VALUE_VALUE        = new OopTypes() { int getValue() { return OopMapValue.VALUE_VALUE;        }};
     public static final OopTypes NARROWOOP_VALUE    = new OopTypes() { int getValue() { return OopMapValue.NARROWOOP_VALUE;         }};
     public static final OopTypes CALLEE_SAVED_VALUE = new OopTypes() { int getValue() { return OopMapValue.CALLEE_SAVED_VALUE; }};
     public static final OopTypes DERIVED_OOP_VALUE  = new OopTypes() { int getValue() { return OopMapValue.DERIVED_OOP_VALUE;  }};
@@ -105,7 +102,6 @@
 
   // Querying
   public boolean isOop()         { return (getValue() & TYPE_MASK_IN_PLACE) == OOP_VALUE;          }
-  public boolean isValue()       { return (getValue() & TYPE_MASK_IN_PLACE) == VALUE_VALUE;        }
   public boolean isNarrowOop()   { return (getValue() & TYPE_MASK_IN_PLACE) == NARROWOOP_VALUE;    }
   public boolean isCalleeSaved() { return (getValue() & TYPE_MASK_IN_PLACE) == CALLEE_SAVED_VALUE; }
   public boolean isDerivedOop()  { return (getValue() & TYPE_MASK_IN_PLACE) == DERIVED_OOP_VALUE;  }
@@ -117,7 +113,6 @@
     int which = (getValue() & TYPE_MASK_IN_PLACE);
          if (which == UNUSED_VALUE) return OopTypes.UNUSED_VALUE;
     else if (which == OOP_VALUE)    return OopTypes.OOP_VALUE;
-    else if (which == VALUE_VALUE)  return OopTypes.VALUE_VALUE;
     else if (which == NARROWOOP_VALUE)   return OopTypes.NARROWOOP_VALUE;
     else if (which == CALLEE_SAVED_VALUE) return OopTypes.CALLEE_SAVED_VALUE;
     else if (which == DERIVED_OOP_VALUE)  return OopTypes.DERIVED_OOP_VALUE;

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/compiler/OopMapVisitor.java	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/compiler/OopMapVisitor.java	Wed Oct 21 16:38:48 2015 -0400
@@ -31,6 +31,5 @@
 public interface OopMapVisitor {
   public void visitOopLocation(Address oopAddr);
   public void visitDerivedOopLocation(Address baseOopAddr, Address derivedOopAddr);
-  public void visitValueLocation(Address valueAddr);
   public void visitNarrowOopLocation(Address narrowOopAddr);
 }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/oops/Method.java	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/oops/Method.java	Wed Oct 21 16:38:48 2015 -0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -52,21 +52,19 @@
   }
 
   private static synchronized void initialize(TypeDataBase db) throws WrongTypeException {
-    Type type                  = db.lookupType("Method");
+    type                       = db.lookupType("Method");
     constMethod                = type.getAddressField("_constMethod");
     methodData                 = type.getAddressField("_method_data");
     methodCounters             = type.getAddressField("_method_counters");
-    methodSize                 = new CIntField(type.getCIntegerField("_method_size"), 0);
     accessFlags                = new CIntField(type.getCIntegerField("_access_flags"), 0);
     code                       = type.getAddressField("_code");
     vtableIndex                = new CIntField(type.getCIntegerField("_vtable_index"), 0);
-    bytecodeOffset = type.getSize();
 
     /*
-    interpreterEntry           = type.getAddressField("_interpreter_entry");
     fromCompiledCodeEntryPoint = type.getAddressField("_from_compiled_code_entry_point");
+    interpreterEntry           = type.getAddressField("_from_interpreted_entry");
+    */
 
-    */
     objectInitializerName = null;
     classInitializerName = null;
   }
@@ -77,16 +75,22 @@
 
   public boolean isMethod()            { return true; }
 
+  // Not a Method field, used to keep type.
+  private static Type type;
+
   // Fields
   private static AddressField  constMethod;
   private static AddressField  methodData;
   private static AddressField  methodCounters;
-  private static CIntField methodSize;
   private static CIntField accessFlags;
   private static CIntField vtableIndex;
-  private static long      bytecodeOffset;
 
   private static AddressField       code;
+  /*
+  private static AddressCField      fromCompiledCodeEntryPoint;
+  private static AddressField       interpreterEntry;
+  */
+
 
   // constant method names - <init>, <clinit>
   // Initialized lazily to avoid initialization ordering dependencies between Method and SymbolTable
@@ -106,11 +110,6 @@
   }
 
 
-  /*
-  private static AddressCField       interpreterEntry;
-  private static AddressCField       fromCompiledCodeEntryPoint;
-  */
-
   // Accessors for declared fields
   public ConstMethod  getConstMethod()                {
     Address addr = constMethod.getValue(getAddress());
@@ -128,7 +127,6 @@
     return (MethodCounters) VMObjectFactory.newObject(MethodCounters.class, addr);
   }
   /** WARNING: this is in words, not useful in this system; use getObjectSize() instead */
-  public long         getMethodSize()                 { return                methodSize.getValue(this);        }
   public long         getMaxStack()                   { return                getConstMethod().getMaxStack();   }
   public long         getMaxLocals()                  { return                getConstMethod().getMaxLocals();         }
   public long         getSizeOfParameters()           { return                getConstMethod().getSizeOfParameters();  }
@@ -265,7 +263,7 @@
   }
 
   public long getSize() {
-    return getMethodSize();
+    return type.getSize() + (isNative() ? 2: 0);
   }
 
   public void printValueOn(PrintStream tty) {
@@ -273,7 +271,6 @@
   }
 
   public void iterateFields(MetadataVisitor visitor) {
-      visitor.doCInt(methodSize, true);
       visitor.doCInt(accessFlags, true);
     }
 

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/runtime/Frame.java	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/runtime/Frame.java	Wed Oct 21 16:38:48 2015 -0400
@@ -536,9 +536,6 @@
       }
     }
 
-    public void visitValueLocation(Address valueAddr) {
-    }
-
     public void visitNarrowOopLocation(Address compOopAddr) {
       addressVisitor.visitCompOopAddress(compOopAddr);
     }

--- a/hotspot/agent/src/share/classes/sun/jvm/hotspot/ui/classbrowser/HTMLGenerator.java	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/agent/src/share/classes/sun/jvm/hotspot/ui/classbrowser/HTMLGenerator.java	Wed Oct 21 16:38:48 2015 -0400
@@ -1220,9 +1220,6 @@
       oms = new OopMapStream(map, OopMapValue.OopTypes.NARROWOOP_VALUE);
       buf.append(omvIterator.iterate(oms, "NarrowOops:", false));
 
-      oms = new OopMapStream(map, OopMapValue.OopTypes.VALUE_VALUE);
-      buf.append(omvIterator.iterate(oms, "Values:", false));
-
       oms = new OopMapStream(map, OopMapValue.OopTypes.CALLEE_SAVED_VALUE);
       buf.append(omvIterator.iterate(oms, "Callee saved:",  true));
 

--- a/hotspot/make/bsd/makefiles/compiler1.make	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/make/bsd/makefiles/compiler1.make	Wed Oct 21 16:38:48 2015 -0400
@@ -28,4 +28,7 @@
 
 VM_SUBDIR = client
 
+# We don't support the JVMCI in a client VM.
+INCLUDE_JVMCI := false
+
 CFLAGS += -DCOMPILER1

--- a/hotspot/make/bsd/makefiles/gcc.make	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/make/bsd/makefiles/gcc.make	Wed Oct 21 16:38:48 2015 -0400
@@ -149,6 +149,7 @@
     PCH_FLAG/sharedRuntimeTrig.o = $(PCH_FLAG/NO_PCH)
     PCH_FLAG/sharedRuntimeTrans.o = $(PCH_FLAG/NO_PCH)
     PCH_FLAG/unsafe.o = $(PCH_FLAG/NO_PCH)
+    PCH_FLAG/jvmciCompilerToVM.o = $(PCH_FLAG/NO_PCH)
 
   endif
 else # ($(USE_CLANG), true)
@@ -320,10 +321,11 @@
 
 # Work around some compiler bugs.
 ifeq ($(USE_CLANG), true)
-  # Clang <= 6.1
+  # Clang < 6 | <= 6.1 | <= 7.0
   ifeq ($(shell expr \
       $(CC_VER_MAJOR) \< 6 \| \
-      \( $(CC_VER_MAJOR) = 6 \& $(CC_VER_MINOR) \<= 1 \) \
+      \( $(CC_VER_MAJOR) = 6 \& $(CC_VER_MINOR) \<= 1 \) \| \
+      \( $(CC_VER_MAJOR) = 7 \& $(CC_VER_MINOR) \<= 0 \) \
     ), 1)
     OPT_CFLAGS/loopTransform.o += $(OPT_CFLAGS/NOOPT)
     OPT_CFLAGS/unsafe.o += -O1

--- a/hotspot/make/bsd/makefiles/jsig.make	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/make/bsd/makefiles/jsig.make	Wed Oct 21 16:38:48 2015 -0400
@@ -63,11 +63,11 @@
 	@echo $(LOG_INFO) Making signal interposition lib...
 ifeq ($(STATIC_BUILD),true)
 	$(QUIETLY) $(CC) -c $(SYMFLAG) $(EXTRA_CFLAGS) $(ARCHFLAG) $(PICFLAG) \
-            $(LFLAGS_JSIG) $(JSIG_DEBUG_CFLAGS) -o $(JSIG).o $<
+                          $(LFLAGS_JSIG) $(JSIG_DEBUG_CFLAGS) -o $(JSIG).o $<
 	$(QUIETLY) $(AR) $(ARFLAGS) $@ $(JSIG).o
 else
 	$(QUIETLY) $(CC) $(SYMFLAG) $(ARCHFLAG) $(SHARED_FLAG) $(PICFLAG) \
-                         $(LFLAGS_JSIG) $(JSIG_DEBUG_CFLAGS) -o $@ $<
+                          $(LFLAGS_JSIG) $(JSIG_DEBUG_CFLAGS) $(EXTRA_CFLAGS) -o $@ $<
 endif
 ifeq ($(ENABLE_FULL_DEBUG_SYMBOLS),1)
   ifeq ($(OS_VENDOR), Darwin)

--- a/hotspot/make/bsd/makefiles/minimal1.make	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/make/bsd/makefiles/minimal1.make	Wed Oct 21 16:38:48 2015 -0400
@@ -38,6 +38,7 @@
 INCLUDE_NMT := false
 INCLUDE_TRACE := false
 INCLUDE_CDS := false
+INCLUDE_JVMCI := false
 
 CXXFLAGS += -DMINIMAL_JVM -DCOMPILER1 -DVMTYPE=\"Minimal\"
 CFLAGS += -DMINIMAL_JVM -DCOMPILER1 -DVMTYPE=\"Minimal\"

--- a/hotspot/make/excludeSrc.make	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/make/excludeSrc.make	Wed Oct 21 16:38:48 2015 -0400
@@ -106,6 +106,25 @@
 	 memTracker.cpp nmtDCmd.cpp mallocSiteTable.cpp
 endif
 
+ifneq (,$(findstring $(Platform_arch_model), x86_64, sparc))
+      # JVMCI is supported only on x86_64 and SPARC.
+else
+      INCLUDE_JVMCI := false
+endif
+
+ifeq ($(INCLUDE_JVMCI), false)
+      CXXFLAGS += -DINCLUDE_JVMCI=0
+      CFLAGS += -DINCLUDE_JVMCI=0
+
+      jvmci_dir := $(HS_COMMON_SRC)/share/vm/jvmci
+      jvmci_dir_alt := $(HS_ALT_SRC)/share/vm/jvmci
+      jvmci_exclude := $(notdir $(wildcard $(jvmci_dir)/*.cpp))	\
+			$(notdir $(wildcard $(jvmci_dir_alt)/*.cpp))
+      Src_Files_EXCLUDE += $(jvmci_exclude) \
+	jvmciCodeInstaller_aarch64.cpp jvmciCodeInstaller_ppc.cpp jvmciCodeInstaller_sparc.cpp \
+	jvmciCodeInstaller_x86.cpp
+endif
+
 -include $(HS_ALT_MAKE)/excludeSrc.make
 
 .PHONY: $(HS_ALT_MAKE)/excludeSrc.make

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/make/gensrc/Gensrc-jdk.vm.ci.gmk	Wed Oct 21 16:38:48 2015 -0400
@@ -0,0 +1,121 @@
+#
+# Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+# DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+#
+# This code is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License version 2 only, as
+# published by the Free Software Foundation.  Oracle designates this
+# particular file as subject to the "Classpath" exception as provided
+# by Oracle in the LICENSE file that accompanied this code.
+#
+# This code is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# version 2 for more details (a copy is included in the LICENSE file that
+# accompanied this code).
+#
+# You should have received a copy of the GNU General Public License version
+# 2 along with this work; if not, write to the Free Software Foundation,
+# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+#
+# Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+# or visit www.oracle.com if you need additional information or have any
+# questions.
+#
+
+default: all
+
+include $(SPEC)
+include MakeBase.gmk
+include JavaCompilation.gmk
+include SetupJavaCompilers.gmk
+
+GENSRC_DIR := $(SUPPORT_OUTPUTDIR)/gensrc/jdk.vm.ci
+SRC_DIR := $(HOTSPOT_TOPDIR)/src/jdk.vm.ci/share/classes
+
+################################################################################
+# Compile the annotation processor
+
+$(eval $(call SetupJavaCompilation, BUILD_JVMCI_OPTIONS, \
+    SETUP := GENERATE_OLDBYTECODE, \
+    SRC := $(SRC_DIR)/jdk.vm.ci.options/src \
+        $(SRC_DIR)/jdk.vm.ci.options.processor/src \
+        $(SRC_DIR)/jdk.vm.ci.inittimer/src, \
+    BIN := $(BUILDTOOLS_OUTPUTDIR)/jvmci_options, \
+    JAR := $(BUILDTOOLS_OUTPUTDIR)/jdk.vm.ci.options.jar, \
+))
+
+$(eval $(call SetupJavaCompilation, BUILD_JVMCI_SERVICE, \
+    SETUP := GENERATE_OLDBYTECODE, \
+    SRC := $(SRC_DIR)/jdk.vm.ci.service/src \
+        $(SRC_DIR)/jdk.vm.ci.service.processor/src, \
+    BIN := $(BUILDTOOLS_OUTPUTDIR)/jvmci_service, \
+    JAR := $(BUILDTOOLS_OUTPUTDIR)/jdk.vm.ci.service.jar, \
+))
+
+################################################################################
+
+PROC_SRC_SUBDIRS := \
+    jdk.vm.ci.compiler \
+    jdk.vm.ci.hotspot \
+    jdk.vm.ci.hotspot.amd64 \
+    jdk.vm.ci.hotspot.sparc \
+    #
+
+PROC_SRC_DIRS := $(patsubst %, $(SRC_DIR)/%/src, $(PROC_SRC_SUBDIRS))
+
+PROC_SRCS := $(filter %.java, $(call CacheFind, $(PROC_SRC_DIRS)))
+
+ALL_SRC_DIRS := $(wildcard $(SRC_DIR)/*/src)
+SOURCEPATH := $(call PathList, $(ALL_SRC_DIRS))
+PROCESSOR_PATH := $(call PathList, \
+    $(BUILDTOOLS_OUTPUTDIR)/jdk.vm.ci.options.jar \
+    $(BUILDTOOLS_OUTPUTDIR)/jdk.vm.ci.service.jar)
+
+$(GENSRC_DIR)/_gensrc_proc_done: $(PROC_SRCS) \
+    $(BUILD_JVMCI_OPTIONS) $(BUILD_JVMCI_SERVICE)
+	$(MKDIR) -p $(@D)
+	$(eval $(call ListPathsSafely,PROC_SRCS,$(@D)/_gensrc_proc_files))
+	$(JAVA_SMALL) $(NEW_JAVAC) \
+	    -sourcepath $(SOURCEPATH) \
+	    -implicit:none \
+	    -proc:only \
+	    -processorpath $(PROCESSOR_PATH) \
+	    -d $(GENSRC_DIR) \
+	    -s $(GENSRC_DIR) \
+	    @$(@D)/_gensrc_proc_files
+	$(TOUCH) $@
+
+TARGETS += $(GENSRC_DIR)/_gensrc_proc_done
+
+################################################################################
+
+$(GENSRC_DIR)/META-INF/services/jdk.vm.ci.options.OptionDescriptors: \
+    $(GENSRC_DIR)/_gensrc_proc_done
+	$(MKDIR) -p $(@D)
+	($(CD) $(GENSRC_DIR)/META-INF/jvmci.options && \
+	    $(RM) -f $@; \
+	    for i in $$(ls); do \
+	      echo $${i}_OptionDescriptors >> $@; \
+	    done)
+
+TARGETS += $(GENSRC_DIR)/META-INF/services/jdk.vm.ci.options.OptionDescriptors
+
+################################################################################
+
+$(GENSRC_DIR)/_providers_converted: $(GENSRC_DIR)/_gensrc_proc_done
+	$(MKDIR) -p $(GENSRC_DIR)/META-INF/services
+	($(CD) $(GENSRC_DIR)/META-INF/jvmci.providers && \
+	    for i in $$($(LS)); do \
+	      c=$$($(CAT) $$i | $(TR) -d '\n\r'); \
+	      $(ECHO) $$i >> $(GENSRC_DIR)/META-INF/services/$$c; \
+	    done)
+	$(TOUCH) $@
+
+TARGETS += $(GENSRC_DIR)/_providers_converted
+
+################################################################################
+
+all: $(TARGETS)
+
+.PHONY: default all

--- a/hotspot/make/linux/makefiles/compiler1.make	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/make/linux/makefiles/compiler1.make	Wed Oct 21 16:38:48 2015 -0400
@@ -28,4 +28,7 @@
 
 VM_SUBDIR = client
 
+# We don't support the JVMCI in a client VM.
+INCLUDE_JVMCI := false
+
 CFLAGS += -DCOMPILER1

--- a/hotspot/make/linux/makefiles/gcc.make	Mon Oct 19 15:48:13 2015 -0400
+++ b/hotspot/make/linux/makefiles/gcc.make	Wed Oct 21 16:38:48 2015 -0400
@@ -213,12 +213,16 @@
   # Since GCC 4.3, -Wconversion has changed its meanings to warn these implicit
   # conversions which might affect the values. Only enable it in earlier versions.
   ifeq "$(shell expr \( $(CC_VER_MAJOR) \> 4 \) \| \( \( $(CC_VER_MAJOR) = 4 \) \& \( $(CC_VER_MINOR) \>= 3 \) \))" "0"
+    # GCC < 4.3
     WARNING_FLAGS += -Wconversion
   endif  
   ifeq "$(shell expr \( $(CC_VER_MAJOR) \> 4 \) \| \( \( $(CC_VER_MAJOR) = 4 \) \& \( $(CC_VER_MINOR) \>= 8 \) \))" "1"
+    # GCC >= 4.8
     # This flag is only known since GCC 4.3. Gcc 4.8 contains a fix so that with templates no
     # warnings are issued: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=11856
     WARNING_FLAGS += -Wtype-limits
+    # GCC < 4.8 don't accept this flag for C++.
+    WARNING_FLAGS += -Wno-format-zero-length
   endif
 endif