To build rsync with mgear:
1. Apply this patch to the rsync source tree.
2. Copy or symlink mgear.mk into the rsync source tree.
3. "make" as usual.

diff --git a/.cvsignore b/.cvsignore
index aa946de..dd2de12 100644
--- a/.cvsignore
+++ b/.cvsignore
@@ -1,3 +1,4 @@
+*.g
 ID
 Makefile
 autom4te*.cache
diff --git a/Makefile.in b/Makefile.in
index 499de47..8a75160 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -1,3 +1,11 @@
+# This is Makefile.in from rsync modified by Matt for use with mgear.
+# (Of course, config.status copies the above message to Makefile.)
+#
+# It works for compiling the C files, and I demonstrated that warnings no longer
+# disappear from Eclipse, which is pretty cool.  However, not everything is
+# converted to use mgear yet.
+include mgear.mk
+
 # Makefile for rsync. This is processed by configure to produce the final
 # Makefile
 
@@ -23,8 +31,8 @@ SHELL=/bin/sh
 
 VERSION=@VERSION@
 
-.SUFFIXES:
-.SUFFIXES: .c .o
+#.SUFFIXES:
+#.SUFFIXES: .c .o
 
 HEADERS=byteorder.h config.h errcode.h proto.h rsync.h ifuncs.h lib/pool_alloc.h
 LIBOBJ=lib/wildmatch.o lib/compat.o lib/snprintf.o lib/mdfour.o lib/md5.o \
@@ -53,10 +61,14 @@ CHECK_SYMLINKS = testsuite/chown-fake.test testsuite/devices-fake.test
 CHECK_OBJS=getgroups.o getfsdev.o t_stub.o t_unsafe.o trimslash.o wildtest.o
 
 # note that the -I. is needed to handle config.h when using VPATH
-.c.o:
-@OBJ_SAVE@
-	$(CC) -I. -I$(srcdir) $(CFLAGS) $(CPPFLAGS) -c $< @CC_SHOBJ_FLAG@
-@OBJ_RESTORE@
+## Matt removed @OBJ_SAVE@ and @OBJ_RESTORE@ because they got in the way.
+cmd-cc=$(CC) -I. -I$(srcdir) $(CFLAGS) $(CPPFLAGS) -c $< @CC_SHOBJ_FLAG@
+$(call mg-define-rule,%.o,%.c,cmd-cc)
+
+## Turn off the built-in implicit rule because it sometimes beats the mgear rule
+## because the mgear rule depends on a genfile that might not exist yet.
+## TODO: Find a better way to handle this.
+%.o: %.c
 
 all: rsync$(EXEEXT)
 
@@ -71,37 +83,35 @@ install: all
 install-strip:
 	$(MAKE) INSTALL_STRIP='-s' install
 
-rsync$(EXEEXT): $(OBJS)
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(OBJS) $(LIBS)
+cmd-exe=$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^ $(LIBS)
+
+$(call mg-define-rule,rsync$(EXEEXT),$(OBJS),cmd-exe)
 
 $(OBJS): $(HEADERS)
 
 flist.o: rounding.h
 
-rounding.h: mkrounding$(EXEEXT)
-	./mkrounding$(EXEEXT) >rounding.h
+cmd-rounding.h=./mkrounding$(EXEEXT) >$@
+$(call mg-define-rule,rounding.h,mkrounding$(EXEEXT),cmd-rounding.h)
 
-mkrounding$(EXEEXT): mkrounding.c rsync.h
-	@sed '1,/^struct file_struct/d; /^}/,$$d' <$(srcdir)/rsync.h >mkrounding.h
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ -I. $(srcdir)/mkrounding.c
-	@rm mkrounding.h
+define cmd-mkrounding-exe
+sed '1,/^struct file_struct/d; /^}/,$$d' <$(srcdir)/rsync.h >mkrounding.h &&\
+$(CC) $(CFLAGS) $(LDFLAGS) -o $@ -I. $(srcdir)/mkrounding.c &&\
+rm mkrounding.h
+endef
+$(call mg-define-rule,mkrounding$(EXEEXT),mkrounding.c rsync.h,cmd-mkrounding-exe)
 
-tls$(EXEEXT): $(TLS_OBJ)
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(TLS_OBJ) $(LIBS)
+$(call mg-define-rule,tls$(EXEEXT),$(TLS_OBJ),cmd-exe)
 
-getgroups$(EXEEXT): getgroups.o
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ getgroups.o $(LIBS)
+$(call mg-define-rule,getgroups$(EXEEXT),getgroups.o,cmd-exe)
 
-getfsdev$(EXEEXT): getfsdev.o
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ getfsdev.o $(LIBS)
+$(call mg-define-rule,getfsdev$(EXEEXT),getfsdev.o,cmd-exe)
 
 TRIMSLASH_OBJ = trimslash.o syscall.o lib/compat.o lib/snprintf.o
-trimslash$(EXEEXT): $(TRIMSLASH_OBJ)
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(TRIMSLASH_OBJ) $(LIBS)
+$(call mg-define-rule,trimslash$(EXEEXT),$(TRIMSLASH_OBJ),cmd-exe)
 
 T_UNSAFE_OBJ = t_unsafe.o syscall.o util.o t_stub.o lib/compat.o lib/snprintf.o
-t_unsafe$(EXEEXT): $(T_UNSAFE_OBJ)
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(T_UNSAFE_OBJ) $(LIBS)
+$(call mg-define-rule,t_unsafe$(EXEEXT),$(T_UNSAFE_OBJ),cmd-exe)
 
 gen:
 	cd $(srcdir) && $(MAKE) -f prepare-source.mak gen
@@ -112,9 +122,11 @@ man:
 proto:
 	cd $(srcdir) && $(MAKE) -f prepare-source.mak proto.h
 
+## Let mgear do the cleaning.
 clean: cleantests
-	rm -f *~ $(OBJS) $(TLS_OBJ) $(CHECK_PROGS) $(CHECK_OBJS) $(CHECK_SYMLINKS) \
-		mkrounding mkrounding.h rounding.h
+#	rm -f *~ $(OBJS) $(TLS_OBJ) $(CHECK_PROGS) $(CHECK_OBJS) $(CHECK_SYMLINKS) \
+#		mkrounding mkrounding.h rounding.h
+	$(call mg-clean-cmd,.)
 
 cleantests:
 	rm -rf ./testtmp*
@@ -160,9 +172,11 @@ check: all $(CHECK_PROGS) $(CHECK_SYMLINKS)
 check29: all $(CHECK_PROGS) $(CHECK_SYMLINKS)
 	rsync_bin=`pwd`/rsync$(EXEEXT) $(srcdir)/runtests.sh --protocol=29
 
+
 wildtest.o: wildtest.c lib/wildmatch.c rsync.h
-wildtest$(EXEEXT): wildtest.o lib/compat.o lib/snprintf.o @BUILD_POPT@
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ wildtest.o lib/compat.o lib/snprintf.o @BUILD_POPT@ $(LIBS)
+$(call mg-define-rule,wildtest$(EXEEXT),wildtest.o lib/compat.o lib/snprintf.o @BUILD_POPT@,cmd-exe)
+
+### Matt stopped here.
 
 testsuite/chown-fake.test:
 	ln -s chown.test $(srcdir)/testsuite/chown-fake.test
diff --git a/doc/.cvsignore b/doc/.cvsignore
index 82b2f29..40fcb95 100644
--- a/doc/.cvsignore
+++ b/doc/.cvsignore
@@ -1,2 +1,3 @@
+*.g
 rsync.pdf
 rsync.ps
diff --git a/lib/.cvsignore b/lib/.cvsignore
index 421376d..5f68c87 100644
--- a/lib/.cvsignore
+++ b/lib/.cvsignore
@@ -1 +1,2 @@
+*.g
 dummy
diff --git a/popt/.cvsignore b/popt/.cvsignore
index 337b0d0..391f286 100644
--- a/popt/.cvsignore
+++ b/popt/.cvsignore
@@ -1,3 +1,4 @@
+*.g
 ID
 Makefile
 config.cache
diff --git a/zlib/.cvsignore b/zlib/.cvsignore
index 421376d..5f68c87 100644
--- a/zlib/.cvsignore
+++ b/zlib/.cvsignore
@@ -1 +1,2 @@
+*.g
 dummy