Make use of new KVO implementation configurable

Source/GNUmakefile

@@ -360,7 +360,7 @@ objc-load.m
 # We have two implementations for Key Value Observing.
 # One highly-optimised one that depends on libobjc2
 # and the original implementation.
-ifeq ($(OBJC_RUNTIME_LIB), ng)
+ifeq ($(GNUSTEP_BASE_HAVE_NEWKVO), 1)
   BASE_MFILES += \
   NSKVOSupport.m \
   NSKVOSwizzling.m

base.make.in

@@ -72,6 +72,9 @@ ifeq ($(BASE_MAKE_LOADED),)
   # Has ICU been found (for NSCalendar, NSLocale, and other locale related)?
   GNUSTEP_BASE_HAVE_ICU=@HAVE_ICU@
 
+  # Has the new KVO implementation been selected.
+  GNUSTEP_BASE_HAVE_NEWKVO=@HAVE_NEWKVO@
+
 
   # The next two are a special case ... we should have either one defined
   # for netservices.  FIXME ... shouldn't these be combined?

configure

@@ -663,6 +663,7 @@ DOT
 USE_GMP
 GS_HAVE_NSURLSESSION
 HAVE_LIBCURL
+HAVE_NEWKVO
 HAVE_LIBDISPATCH_RUNLOOP
 HAVE_LIBDISPATCH
 HAVE_ICU
@@ -862,6 +863,7 @@ enable_icu
 enable_libdispatch
 with_dispatch_include
 with_dispatch_library
+enable_newkvo
 with_curl
 enable_nsurlsession
 with_gmp_include
@@ -1556,6 +1558,7 @@ Optional Features:
   --disable-zeroconf		Disable NSNetServices support
   --disable-icu			Disable International Components for Unicode
   --disable-libdispatch		Disable dispatching blocks via libdispatch
+  --disable-newkvo		Disable new KVO implementation
   --disable-nsurlsession  		Disable support for NSURLSession
 
   --enable-setuid-gdomap        Enable installing gdomap as a setuid
@@ -14521,6 +14524,34 @@ fi
 
 
 
+#--------------------------------------------------------------------
+# Check for whether the new KVO implementation is enabled (only with
+# the NG runtime)
+#--------------------------------------------------------------------
+HAVE_NEWKVO=0
+# Check whether --enable-newkvo was given.
+if test ${enable_newkvo+y}
+then :
+  enableval=$enable_newkvo;
+else $as_nop
+
+if test "$OBJC_RUNTIME_LIB" = "ng"; then
+  enable_newkvo=yes
+else
+  enable_newkvo=no
+fi
+fi
+
+if test "x$enable_newkvo" = "xyes"
+then
+  if test "$OBJC_RUNTIME_LIB" = "ng"; then
+    HAVE_NEWKVO=1
+  else
+    echo "You are not using the new runtime ... newkvo not available"
+  fi
+fi
+
+
 #--------------------------------------------------------------------
 # Check for libcurl
 # See DEPENDENCIES POLICY at the start of this file.

configure.ac

@@ -3686,6 +3686,28 @@ fi
 AC_SUBST(HAVE_LIBDISPATCH_RUNLOOP)
 
 
+#--------------------------------------------------------------------
+# Check for whether the new KVO implementation is enabled (only with
+# the NG runtime)
+#--------------------------------------------------------------------
+HAVE_NEWKVO=0
+AC_ARG_ENABLE(newkvo,
+  [  --disable-newkvo		Disable new KVO implementation],,[
+if test "$OBJC_RUNTIME_LIB" = "ng"; then
+  enable_newkvo=yes
+else
+  enable_newkvo=no
+fi])
+if test "x$enable_newkvo" = "xyes"
+then
+  if test "$OBJC_RUNTIME_LIB" = "ng"; then
+    HAVE_NEWKVO=1
+  else
+    echo "You are not using the new runtime ... newkvo not available"
+  fi
+fi
+AC_SUBST(HAVE_NEWKVO)
+
 #--------------------------------------------------------------------
 # Check for libcurl
 # See DEPENDENCIES POLICY at the start of this file.