Origin for each line in Makefile from check-in b8cca3a6b4:

88f96696b7 2019-05-03        rkeene: CPPFLAGS := -I. -DUSE_TCL_STUBS=1 -DXVFS_MODE_FLEXIBLE
e5b6962adf 2019-05-02        rkeene: CFLAGS   := -fPIC -g3 -ggdb3 -Wall
e5b6962adf 2019-05-02        rkeene: LDFLAGS  :=
9bcf758fef 2019-05-08        rkeene: LIBS     := -ltclstub8.6
e5b6962adf 2019-05-02        rkeene: 
0a9369ff13 2019-05-02        rkeene: all: example.so
0a9369ff13 2019-05-02        rkeene: 
e90770a5a7 2019-05-02        rkeene: example.c: $(shell find example -type f) $(shell find lib -type f) xvfs.c.rvt xvfs-create Makefile
0a9369ff13 2019-05-02        rkeene: 	./xvfs-create --directory example --name example > example.c.new
0a9369ff13 2019-05-02        rkeene: 	mv example.c.new example.c
0a9369ff13 2019-05-02        rkeene: 
b8cca3a6b4 2019-05-08        rkeene: example.o: example.c xvfs-core.h xvfs-core.c Makefile
e5b6962adf 2019-05-02        rkeene: 	$(CC) $(CPPFLAGS) $(CFLAGS) -o example.o -c example.c
e5b6962adf 2019-05-02        rkeene: 
b8cca3a6b4 2019-05-08        rkeene: example.so: example.o Makefile
b8cca3a6b4 2019-05-08        rkeene: 	$(CC) $(CFLAGS) $(LDFLAGS) -shared -o example.so example.o $(LIBS)
e90770a5a7 2019-05-02        rkeene: 
f74a2e47ab 2019-05-02        rkeene: test: example.so
d121970301 2019-05-02        rkeene: 	echo 'if {[catch { load ./example.so Xvfs_example; source //xvfs:/example/main.tcl }]} { puts stderr $$::errorInfo; exit 1 }; exit 0' | tclsh
0a9369ff13 2019-05-02        rkeene: 
0a9369ff13 2019-05-02        rkeene: clean:
0a9369ff13 2019-05-02        rkeene: 	rm -f example.so example.o example.c
0a9369ff13 2019-05-02        rkeene: 
0a9369ff13 2019-05-02        rkeene: distclean: clean
0a9369ff13 2019-05-02        rkeene: 
0a9369ff13 2019-05-02        rkeene: .PHONY: all clean distclean test