### conservative precompilation
PCH_UNIQ=uniq -d
### aggressive precompilation
# PCH_UNIQ=uniq -u

all.h.gch: all.h
	$(CXX) $(PCH_CPPFLAGS) $(CXXFLAGS) $(CPPFLAGS) $(INCLUDES) -o $@ $<

all.h:
	grep --no-filename "^#include" $(srcdir)/*.{c,cpp,h} \
	$(PCH_FILTER) | sort | $(PCH_UNIQ) > $@

#all.h:
#	grep --no-filename "^#include" $(srcdir)/*.{c,cpp,h} | \
#	if [ -f pch-blacklist.sed ] ; then sed -f pch-blacklist.sed; fi | sort | $(PCH_UNIQ) > $@