(Net|Open)BSD Make: implicit C header dependencies

[taylor_venable]

Using BSD Make (specifically, I'm doing this on OpenBSD) I can use the wonderful incantation:

.SUFFIXES:	.o .cc

.cc.o:
	g++ -g -Wall -c ${.IMPSRC}

To compile C or C++ source to object files from corresponding source. But there's no dependency on the header files, which can obviously be somewhat important. Is there a quick and easy way to put the corresponding header file into this equation too?

I realize that normally alpha.h depends on beta.h and so forth, and that these special dependencies can be done the "normal" way with Make, so I am curious about the generic case that every .cc (C++ source) file depends on the .hh (C++ header) file of the same name.

Thanks for any tips.

[Oko]

I am not 100% sure what are you trying to accomplish but you should start by reading bsd.ports.mk. Normally compiler optimization for software which one tries to port to OpenBSD is done by careful reading of the output of

make build

and then properly adjusting /usr/obj/portname/Makefile (or config.mk) file and generating patches.

I am not coding on regular basis so I would have hard time to help you further with compiler optimization. If you are trying to code new application using gcc on OpenBSD you should probably read man pages for gcc. There are quite a few knobs that you can turn of and on. (I also do not use C++ as it is against my religion).
If you are trying just to port software to OpenBSD start by reading documentation from OpenBSD web-site. In particular you can find magic point presentation how to create an elementary port but your question is little bit deeper than that.

[taylor_venable]

Originally Posted by Oko

I am not 100% sure what are you trying to accomplish

Thanks for the reply. Here's an example:

*.cc:	*.hh

This ensures that every .cc file depends on every .hh file so when a header gets touched, it forces everything depending on a .cc file to get rebuilt. The downside of course is that I can touch and make a header out of nothing and every object gets rebuilt for no reason. I'm looking for a way to say that a specific .cc file depends on the .hh file with the same name (i.e. foo.cc depends on foo.hh, bar.cc depends on bar.hh, and so on) to the effect that when I modify foo.hh then foo.o gets rebuilt. I know about mkdep, which basically does this plus more, but I was looking for a way to do it in make. Half out of curiosity, half because it may be useful for other things that mkdep doesn't understand.

Also, I should note this isn't for anything in Ports or the rest of the system, but I'll check out the system make files for ideas.

[ephemera]

Originally Posted by taylor_venable

... so I am curious about the generic case that every .cc (C++ source) file depends on the .hh (C++ header) file of the same name.

you could use:

.SUFFIXES:	.o .cc

.cc.o:
	g++ -g -Wall -c ${.IMPSRC}

*.o: $*.hh