Added a gnumake 'target-specfic variable' to add the C preprocessor define necessary for clean DLL linkage.

platform/win32/Makefile.win32

@@ -30,7 +30,7 @@
 #
 # Author: Oliver Schmidt <ol.sc@web.de>
 #
-# $Id: Makefile.win32,v 1.18 2010/01/28 12:46:16 oliverschmidt Exp $
+# $Id: Makefile.win32,v 1.19 2010/01/30 11:52:01 oliverschmidt Exp $
 #
 
 TARGET_LIBFILES = /lib/w32api/libws2_32.a /lib/w32api/libiphlpapi.a
@@ -55,6 +55,10 @@ ifdef PLATFORM_BUILD
              -u _cfs_open -u _cfs_opendir -u _uiplib_ipaddrconv
 endif
 
+### Set a target-specific variable value
+${foreach PRG,$(PRGS),${addprefix $(OBJECTDIR)/, \
+                      $(${call appname,$(PRG)_src:.c=.o})}}: CFLAGS += -D_USRDLL
+
 ### Generate the module-link prerequisites
 define prg_template
 $(1).prg: $${addprefix $$(OBJECTDIR)/,$$($(2)_src:.c=.o)}