Re: [patch/rfc] Generate makefile dependencies

[Andrew Cagney <cagney@gnu.org>]

> On Mon, Mar 08, 2004 at 11:24:20AM -0500, Andrew Cagney wrote:
> 
>>>>> >>Date: Sun, 07 Mar 2004 19:35:34 -0500
>>>>
>>>>>> >>>From: Andrew Cagney <cagney@gnu.org>
>>>>>> >>>
>>>>>> >>>The attached, er, hack, modifies configure.in so that all the Makefile
>>>>>> >>>dependencies are generated during configure time:
>>>>>> >>>
>>>>>> >>>	defs_h = ...
>>>>>> >>>	foo.o: foo.c $(defs_h)
>>>>>> >>>
>>>>>> >>>It exploits the fact that GDB's code base is very consistent in its use
>>>>>> >>>of "foo.h" vs <foo.h> -- the former is assumed to be local, the latter
>>>>>> >>>in a system library.
>>>
>>>> >
>>>> >
>>>> >Won't it be better to use "gcc -MM" when we compile with GCC?
>>
>>> 
>>> It would, except we can't assume GCC :-(.  Better to always use the sed 
>>> script as that way we'll know it always (hopefully :-) works.
>>> 
>>> It needs comments (and a doco update).
> 
> 
> So what about using the output of gcc -MM (or one of the other -M
> options?) to generate dependencies in the source directory, like BFD
> does?

How is embedding this stuff in the source directory better?

> BTW, your comment about running automake to update deps in BFD is
> actually incorrect.  You run 'make dep-am', which IIRC seds Makefile.am
> and maye regenerates Makefile.in; the dependencies aren't managed by
> automake.  Recent versions of automake do have top-notch dependency
> support though.

It appears to eventually run "gcc -MM" ... :-(

Andrew