get_cs_flags = $(foreach target,$(subst .,_,$(subst -,_,$($(2)))),$($(target)_$(1)FLAGS))
get_cs_all_flags = $(foreach type,$(2),$(call get_cs_flags,$(1),$(type)))
get_cs_compile = $(if $(subst C,,$(1)),$($(1)COMPILE),$(COMPILE))
get_cs_cmdline = $(call get_cs_compile,$(1)) $(call get_cs_all_flags,$(1),check_PROGRAMS bin_PROGRAMS lib_LTLIBRARIES) -fsyntax-only

check-syntax:
	s=$(suffix $(CHK_SOURCES));\
	if   [ "$$s" = ".c"   ]; then \
	    $(call get_cs_cmdline,C) $(call get_cs_cmdline,CPP) $(CHK_SOURCES);\
	else exit 1; fi

.PHONY: check-syntax
