[build/rfc] automatic md file dependencies

[Ian Lance Taylor]

Richard Henderson <rth@redhat.com> writes:

> +# Dependencies for the md file.  The first time through, we just assume
> +# the md file itself and the generated dependency file (in order to get
> +# it built).  The second time through we have the dependency file.
> +-include mddeps.mk
> +MD_DEPS = s-mddeps $(md_file) $(MD_INCLUDES)
> +
> +s-mddeps: $(md_file) $(MD_INCLUDES) build/genmddeps$(build_exeext)
> +	$(RUN_GEN) build/genmddeps$(build_exeext) $(md_file) > tmp-mddeps
> +	mv tmp-mddeps mddeps.mk
> +	$(STAMP) s-mddeps

move-if-change?

Ian