Re: [patch/rfc] Generate makefile dependencies

[Michael Snyder <msnyder@redhat.com>]

Andrew Cagney wrote:
>>>> 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?
>>
>>
>>
>> Because it doesn't need to rely on assumptions about the GDB coding
>> style, and it doesn't require parsing all the source files when we
>> configure?
> 
> 
> Er, that's a postive - the dependency list is guarenteed to always match 
> the shipped source.

Might be too big a step, depending on how expensive it is.
I think this has been experimented with before, and was abandoned
because there are a lot of header files on which -everything- depends.
If the makefile dependencies are -too- correct, then touching any
of those files causes everything to rebuild.  Sometimes you want
that -- but sometimes you don't.

Can I suggest maybe having a separate make target for
generating the dependencies?  And maybe a second one for
reverting them?  Then you could choose when to do it.


>> It's like regenerating configure; we try not to run
>> autoconf during the build process, and not just because autoconf is so
>> finicky.
> 
> 
> Andrew
> 
> 
>