[PATCH 00/12] Re: Makefile: add missing header dependency rules

From: Jonathan Nieder <jrnieder@gmail.com>
Date: Jan 26, 2010, 15:43 UTC
Message-ID: <20100126154357.GA4895@progeny.tock>
In-Reply-To: <7v3a1u6bfz.fsf@alter.siamese.dyndns.org>

Junio C Hamano wrote:

> Jonathan Nieder <jrnieder@gmail.com> writes:

Show 6 quoted lines

>> These patches are independent of the jn/makefile topic.  I sent them
>> before, but I screwed up the sender so nobody received them.  Anyway,
>> perhaps they could be useful.
>
> I found all of them sensible but it seems to be based on version that is a
> bit behind...

Thanks. Patches 1-5 below are those I sent before, rebased against maint. Since last time, remote-curl.o gained a few more dependencies, which are included.

The remainder of this series is based on a merge of master and patches 1-5:

 Patch 6 adds another missing header dependency rule.  It is not
 included with the others because it applies to master, not maint.

 Patches 7-12 revisit the topic of generating header dependency
 rules on the fly.  I updated them to produce patches 1-6, so I
 thought, why not get some feedback on their present state?

Patch 7 clumps the header dependency rules together. I think this makes them more readable; more importantly, later this will allow ifdef'ing them out later in one fell swoop.

Patches 8-9 and 11 list all targets that can depend on headers in a new OBJECTS variable, for use in patches 10 and 12.

Patch 10 generates header dependency rules on the fly. The resulting dependency rules contain no useless dependencies (unlike the hard-coded ones where almost everything depends on $(LIB_H)), so this might be interesting to people wishing to speed up the edit-compile-run cycle.

This only works with gcc. It should be possible to teach the relevant options to clink.pl if there is demand, but not SCO cc.

Patch 12 is what I am most interested in: it uses the computed dependencies to check that the hard-coded dependency rules are correct. In the long term, maybe we will be able to get rid of the hard-coded header dep rules altogether; in the short term, I am hoping this checker can be useful for avoiding problems with the hard-coded rules without spending too much human time on it.

Enjoy,
Jonathan Nieder (12):
  Makefile: add missing header file dependencies
  Makefile: make sure test helpers are rebuilt when headers change
  Makefile: remove wt-status.h from LIB_H
  Makefile: clean up http-walker.o dependency rules
  Makefile: drop dependency on $(wildcard */*.h)
  Makefile: transport.o depends on branch.h now
  Makefile: rearrange dependency rules
  Makefile: disable default implicit rules
  Makefile: list generated object files in OBJECTS macro
  Makefile: lazily compute header dependencies
  Makefile: list standalone program object files in PROGRAM_OBJS
  Teach Makefile to check header dependencies