Re: [Emacs-diffs] /srv/bzr/emacs/trunk r99848: (compilation-save-buffers-predicate):

[Sam Steingold]

Stefan Monnier wrote:
> > > > > > - I like where this is going, but I'm not sure this is enough.
> > > > > > Could you explain how you see it being used?
> > > > > > if you edit a huge file which is expensive to save, you do not want it
> > > > > > to be saved whenever you start a compilation elsewhere.
> > > > > ;-) that part I understand of course.
> > > > > But I mean what value do you expect users to use it with?
> > > > > Would they globally set it to save one particular directory of theirs?
> > > > > What if they have more than one project?
> > > > this is problematic because compile does not announce what it's working
> > > > directory is.
> > > Any reason why we can't fix that?
> > no, and here is a solution:
>
> I don't understand.  You're saying there's no reason why we can't fix it
> and then you go ahead and point me to a workaround.  Maye we're not
> talking about the same thing.  By "announce what it's working dir is"
> I mean "make sure default-directory has the proper value".
>
> Introducing `compile-default-directory' is not the end of the world, but
> to my naive eyes, if `default-directory' doesn't point to the right
> place, it's a bug to be fixed.

default-directory "Automatically becomes buffer-local when set in any fashion"
this means that it is useless in compilation-save-buffers-predicate because 
that is called inside the buffer to be saved and thus for it default-directory 
should be the directory where the buffer is located.

> > > How 'bout this:
> > > - we provide some way for the user to explain to compile.el how to find
> > > her projects's root directories (e.g. a list of tell-tale file names).
> > this is tricky: some files might be ordinary for some projects and the
> > tell-tale for others.
>
> I know, that's a significant problem, but I can't think of a really good
> solution other than push it onto the user by providing a customizable
> variable.  My main goal here is to make sure that we can support the
> case where the user has several projects, which seems like a common
> enough case, especially for Free Software hackers.

I think this variable should be buffer-local (with an eye on being set in 
dir_locals).

> > > - and we can also provide an option to "cd to project's root before
> > > running the command".
> > I doubt the value of this.
>
> I've used several build systems where this is necessary (e.g. a single
> Makefile at the root, or something equivalent).  I usually work around
> it with something like M-x compile RET cd ..; make RET, but if `compile'
> could insert the "cd .." for me when needed it would be even better.

this sounds like a case for yet another buffer-local variable - build-directory

>
>>> How does that sound?
>> fine.
>> gonna do it?
>
> ;-)
>
>
>         Stefan
>
>
> PS: We're talking here mostly about designing a good default value for
> your new variable, right?  Or if not default, at least a value that can
> be listed in the possible options so the end user doesn't have to write
> her own predicate function.
>
>
>