Re: [patch/rfc] Generate makefile dependencies

Michael Snyder
2004-03-08T23:13:44Z

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
>
>
>