--- old/makefiles/GensrcX11Wrappers.gmk	2012-12-05 14:15:07.326745029 +0100
+++ new/makefiles/GensrcX11Wrappers.gmk	2012-12-05 14:15:07.150745021 +0100
@@ -23,47 +23,71 @@
 # questions.
 #
 
-
 # This file is responsible for extracting the x11 native struct offsets to
-# the xawt Java library. This is done by compiling and running a native
-# binary, which dumps output to a text file. The offsets differ on 32 and 64
-# bit systems, so care must be taken here.
+# the xawt Java library. The tool needs to be run on the os/arch that
+# will host the final jvm, thus the tool cannot be used when cross compiling.
+
+# To enable cross compiling, the two versions of the generated offset file,
+# sizes.32 and sizes.64 are committed into the source code repository.
+# These are the once used.
 
-# Note: Some of the more complex logic here is most likely not needed anymore.
+# However when not cross compiling, the offset generator tool is built and
+# run, to verify that it still generates the same sizes.32 and sizes.64.
 
 GENSRC_X11WRAPPERS :=
+# Put temporary c-code and executable to calculate offsets here.
+# Also put verification offset file here as well.
 GENSRC_X11WRAPPERS_TMP := $(JDK_OUTPUTDIR)/gensrc_x11wrappers
-GENSRC_X11WRAPPERS_DST := $(JDK_OUTPUTDIR)/gensrc
+# Put the generated Java classes used to interface X11 from awt here.
+GENSRC_X11WRAPPERS_DST := $(JDK_OUTPUTDIR)/gensrc/sun/awt/X11
 
-GENSRC_SIZER_SRC := $(JDK_TOPDIR)/src/solaris/classes/sun/awt/X11/generator
-
-# Normal case is to generate version according to target bits
-GENSRC_SIZES := sizes.$(OPENJDK_TARGET_CPU_BITS)
+# The pre-calculated offset file are stored here:
+GENSRC_SIZER_DIR := $(JDK_TOPDIR)/src/solaris/classes/sun/awt/X11/generator
 
+# Normal case is to generate only according to target bits
+GENSRC_X11_VERSION := $(OPENJDK_TARGET_CPU_BITS)
 ifeq ($(OPENJDK_TARGET_CPU_BITS), 64)
-ifneq ($(OPENJDK_TARGET_OS), linux)
-# On all 64-bit systems except Linux, generate both 32 and 64 bit versions
-GENSRC_SIZES := sizes.32 sizes.64
-endif
+  ifneq ($(OPENJDK_TARGET_OS), linux)
+  # On all 64-bit systems except Linux, generate both 32 and 64 bit versions
+  GENSRC_X11_VERSION := 32 64
+  endif
 else
-ifeq ($(OPENJDK_TARGET_OS), solaris)
-# As a special case, solaris 32-bit also generates the 64-bit version
-GENSRC_SIZES := sizes.32 sizes.64
-endif
+  ifeq ($(OPENJDK_TARGET_OS), solaris)
+  # As a special case, solaris 32-bit also generates the 64-bit version
+  GENSRC_X11_VERSION := 32 64
+  endif
 endif
 
-##########################################################################################
+GENSRC_X11_SIZES_USED := $(addprefix $(GENSRC_X11WRAPPERS_TMP)/sizes.,$(GENSRC_X11_VERSION))
+
+# Copy only the sizes.* files that are actually needed. WrapperGenerator picks up any it finds from the 
+# file prefix it is given so those not needed need to be hidden.
+$(GENSRC_X11WRAPPERS_TMP)/sizes.%: $(GENSRC_SIZER_DIR)/sizes.%
+	$(install-file)
+
+# Run the tool on the offset files copied from the source repository to generate several Java classes 
+# used in awt.
+$(JDK_OUTPUTDIR)/gensrc/_the.generated.x11 : $(GENSRC_X11_SIZES_USED)
+	$(MKDIR) -p $(GENSRC_X11WRAPPERS_DST)
+	$(TOOL_WRAPPERGENERATOR) $(GENSRC_X11WRAPPERS_DST) $(GENSRC_SIZER_DIR)/xlibtypes.txt "gen" $(GENSRC_X11WRAPPERS_TMP)/sizes
+	$(TOUCH) $@
 
-$(GENSRC_X11WRAPPERS_TMP)/sizer/sizer.%.c : $(GENSRC_SIZER_SRC)/xlibtypes.txt
+GENSRC_X11WRAPPERS += $(JDK_OUTPUTDIR)/gensrc/_the.generated.x11
+
+ifneq ($(COMPILE_TYPE),cross)
+    # This is not a cross compile, regenerate the offset file, so that we
+    # can compare it with the version in the source code repository.
+
+    # Generate the C code for the program that will output the offset file.
+    $(GENSRC_X11WRAPPERS_TMP)/sizer.%.c : $(GENSRC_SIZER_DIR)/xlibtypes.txt
 	$(ECHO) "Generating X11 wrapper ($*-bit version)"
 	$(MKDIR) -p $(@D)
-	$(RM) $@
-	$(TOOL_WRAPPERGENERATOR) $(@D) $< "sizer" $*
+	$(TOOL_WRAPPERGENERATOR) $(@D) $(GENSRC_SIZER_DIR)/xlibtypes.txt "sizer" $*
 
-$(GENSRC_X11WRAPPERS_TMP)/sizer/sizer.%.exe : $(GENSRC_X11WRAPPERS_TMP)/sizer/sizer.%.c
+    # Compile the C code into an executable.
+    $(GENSRC_X11WRAPPERS_TMP)/sizer.%.exe : $(GENSRC_X11WRAPPERS_TMP)/sizer.%.c
 	$(MKDIR) -p $(@D)
-	$(RM) $@ $@.tmp
-	(cd $(@D) && $(BUILD_CC) -m$* -o $@.tmp $< \
+	(cd $(@D) && $(CC) -m$* -o $@ $< \
               $(X_CFLAGS) \
               $(X_LIBS) \
               -I$(JDK_OUTPUTDIR)/include \
@@ -74,33 +98,18 @@
               -I$(JDK_TOPDIR)/src/solaris/native/sun/awt \
 	      -I$(JDK_TOPDIR)/src/share/native/sun/awt/debug \
 	      -I$(JDK_TOPDIR)/src/share/native/sun/awt/image/cvutils -lc)
-	$(MV) $@.tmp $@
 
-# Run the generated sizer binary to create the sizes text file
-$(GENSRC_X11WRAPPERS_TMP)/sizer/sizes.% : $(GENSRC_X11WRAPPERS_TMP)/sizer/sizer.%.exe
-	$(MKDIR) -p $(@D)
-	$(RM) $@ $@.tmp
-	$< > $@.tmp
-	$(MV) $@.tmp $@
-
-ifeq ($(OPENJDK_TARGET_OS)-$(OPENJDK_TARGET_CPU), solaris-x86)
-  # On solaris-x86 we also need to create the 64-bit version, but we can't run a 64-bit binary
-  # As a workaround, copy this from a pre-generated file.
-$(GENSRC_X11WRAPPERS_TMP)/sizer/sizes.64 : $(JDK_TOPDIR)/src/solaris/classes/sun/awt/X11/generator/sizes.64-solaris-i386
+    .PRECIOUS: $(GENSRC_X11WRAPPERS_TMP)/sizer.%.exe $(GENSRC_X11WRAPPERS_TMP)/sizer.%.c
+
+    # Run the executable create the offset file and check that it is identical
+    # to the offset file in the source code repository.
+    $(GENSRC_X11WRAPPERS_TMP)/sizes.%.verification : $(GENSRC_X11WRAPPERS_TMP)/sizer.%.exe
 	$(MKDIR) -p $(@D)
-	$(RM) $@
-	$(CP) $< $@
-endif
+	$(GENSRC_X11WRAPPERS_TMP)/sizer.$*.exe > $@.tmp
+	$(ECHO) Verifying $(GENSRC_X11WRAPPERS_TMP)/sizes.$*.verification.tmp to $(GENSRC_SIZER_DIR)/sizes.$*
+	$(DIFF) $(GENSRC_X11WRAPPERS_TMP)/sizes.$*.verification.tmp $(GENSRC_SIZER_DIR)/sizes.$*
+	mv $@.tmp $@
 
-$(GENSRC_X11WRAPPERS_DST)/_the.generated.x11 : $(foreach S,$(GENSRC_SIZES),$(GENSRC_X11WRAPPERS_TMP)/sizer/$(S))
-	$(RM) $@
-	$(MKDIR) -p $(@D)/sun/awt/X11
-	$(TOOL_WRAPPERGENERATOR) $(@D)/sun/awt/X11 $(GENSRC_SIZER_SRC)/xlibtypes.txt "gen" $(GENSRC_X11WRAPPERS_TMP)/sizer/sizes
-ifeq ($(OPENJDK_TARGET_OS)-$(OPENJDK_TARGET_CPU), solaris-x86_64)
-  # On solaris-x86_64, as a safety measure, compare the generated file with the checked-in version 
-	$(ECHO) COMPARING $(GENSRC_X11WRAPPERS_TMP)/sizer/sizes.64 and $(GENSRC_SIZER_SRC)/sizes.64-solaris-i386
-	$(DIFF) $(GENSRC_X11WRAPPERS_TMP)/sizer/sizes.64 $(GENSRC_SIZER_SRC)/sizes.64-solaris-i386
+    GENSRC_X11WRAPPERS += $(GENSRC_X11WRAPPERS_TMP)/sizes.$(OPENJDK_TARGET_CPU_BITS).verification
 endif
-	$(TOUCH) $@
 
-GENSRC_X11WRAPPERS += $(GENSRC_X11WRAPPERS_DST)/_the.generated.x11