Modification of a patch from Debian: eliminate the endless rebuilds

of basically unchanged binaries due to the compulsory rebuild of
version.o. version.o now depends normally on version2.def, which is
constructed using much the same if statements that version.o used to
use, except that it's not overwritten at all if its contents don't
need to change.

[originally from svn r8931]

diff --git a/Recipe b/Recipe
index 3925447711b53e1dac8081f95a778944af4c6e17..e57e7cd226415958f38c2dadc136ccb09077140b 100644 (file)
--- a/Recipe
+++ b/Recipe
@@ -110,52 +110,65 @@ FORCE:
 # For Unix, we also need the gross MD5 hack that causes automatic
 # version number selection in release source archives.
 !begin gtk
-version.o: FORCE;
-FORCE:
+version.o: version.c version2.def
+       $(CC) $(COMPAT) $(XFLAGS) $(CFLAGS) `cat version2.def` -c version.c
+version2.def: FORCE
        if test -z "$(VER)" && test -f manifest && md5sum -c manifest; then \
-               $(CC) $(COMPAT) $(XFLAGS) $(CFLAGS) `cat version.def` -c version.c; \
+               cat version.def > version2.def.new; \
        elif test -z "$(VER)" && test -d .svn && svnversion . >/dev/null 2>&1; then \
-               $(CC) $(COMPAT) $(XFLAGS) $(CFLAGS) "-DREVISION=`svnversion .`" -c version.c; \
+               echo "-DREVISION=`svnversion .`" >version2.def.new; \
+       else \
+               echo "$(VER)" >version2.def.new; \
+       fi && \
+       if diff -q version2.def.new version2.def; then \
+               rm version2.def.new; \
        else \
-               $(CC) $(COMPAT) $(XFLAGS) $(CFLAGS) $(VER) -c version.c; \
+               mv version2.def.new version2.def; \
        fi
+.PHONY: FORCE
 !end
 !specialobj gtk version
 !begin nestedvm
-version.o: FORCE;
-FORCE:
+version.o: version.c version2.def
+       $(CC) $(COMPAT) $(XFLAGS) $(CFLAGS) `cat version2.def` -c version.c
+version2.def: FORCE
        if test -z "$(VER)" && test -f manifest && md5sum -c manifest; then \
-               $(CC) $(COMPAT) $(XFLAGS) $(CFLAGS) `cat version.def` -c version.c; \
+               cat version.def > version2.def.new; \
        elif test -z "$(VER)" && test -d .svn && svnversion . >/dev/null 2>&1; then \
-               $(CC) $(COMPAT) $(XFLAGS) $(CFLAGS) "-DREVISION=`svnversion .`" -c version.c; \
+               echo "-DREVISION=`svnversion .`" >version2.def.new; \
+       else \
+               echo "$(VER)" >version2.def.new; \
+       fi && \
+       if diff -q version2.def.new version2.def; then \
+               rm version2.def.new; \
        else \
-               $(CC) $(COMPAT) $(XFLAGS) $(CFLAGS) $(VER) -c version.c; \
+               mv version2.def.new version2.def; \
        fi
+.PHONY: FORCE
 !end
 !specialobj nestedvm version
 # For OS X, this is made more fiddly by the fact that we don't have
 # md5sum readily available. We do, however, have `md5 -r' which
 # generates _nearly_ the same output, but it has no check function.
 !begin osx
-version.ppc.o: FORCE;
-FORCE:
+version.ppc.o: version.c version2.def
+       $(CC) -arch ppc $(COMPAT) $(XFLAGS) $(CFLAGS) `cat version2.def` -c version.c
+version.i386.o: version.c version2.def
+       $(CC) -arch i386 $(COMPAT) $(XFLAGS) $(CFLAGS) `cat version2.def` -c version.c
+version2.def: FORCE
        if test -z "$(VER)" && test -f manifest && (md5 -r `awk '{print $$2}' manifest` | diff -w manifest -); then \
-               $(CC) -arch ppc $(COMPAT) $(XFLAGS) $(CFLAGS) `cat version.def` -c version.c -o version.ppc.o; \
+               cat version.def > version2.def.new; \
        elif test -z "$(VER)" && test -d .svn && svnversion . >/dev/null 2>&1; then \
-               $(CC) -arch ppc $(COMPAT) $(XFLAGS) $(CFLAGS) "-DREVISION=`svnversion .`" -c version.c -o version.ppc.o; \
+               echo "-DREVISION=`svnversion .`" >version2.def.new; \
        else \
-               $(CC) -arch ppc $(COMPAT) $(XFLAGS) $(CFLAGS) $(VER) -c version.c -o version.ppc.o; \
-       fi
-version.i386.o: FORCE2;
-FORCE2:
-       if test -z "$(VER)" && test -f manifest && (md5 -r `awk '{print $$2}' manifest` | diff -w manifest -); then \
-               $(CC) -arch i386 $(COMPAT) $(XFLAGS) $(CFLAGS) `cat version.def` -c version.c -o version.i386.o; \
-       elif test -z "$(VER)" && test -d .svn && svnversion . >/dev/null 2>&1; then \
-               $(CC) -arch i386 $(COMPAT) $(XFLAGS) $(CFLAGS) "-DREVISION=`svnversion .`" -c version.c -o version.i386.o; \
+               echo "$(VER)" >version2.def.new; \
+       fi && \
+       if diff -q version2.def.new version2.def; then \
+               rm version2.def.new; \
        else \
-               $(CC) -arch i386 $(COMPAT) $(XFLAGS) $(CFLAGS) $(VER) -c version.c -o version.i386.o; \
+               mv version2.def.new version2.def; \
        fi
-!end
+.PHONY: FORCE
 !specialobj osx version
 
 # make install for Unix.