Re: Automatically keeping "last modified" up to date

[Daniel J S. <dan...@ie...>]

On 08/06/2013 03:48 PM, Allin Cottrell wrote:
> On Tue, 6 Aug 2013, Daniel J Sebald wrote:
>
>> On 08/06/2013 03:01 PM, Allin Cottrell wrote:
>>> On Tue, 6 Aug 2013, Ethan A Merritt wrote:
>>>
>>>> On Tuesday, August 06, 2013 12:26:04 pm Allin Cottrell wrote:
>>>>> There's one other fishy thing in that neighborhood. When I do
>>>>> a cvs update it seems I quite often get the cvs 'M' flag
>>>>> indicating that src/version.c is modified, when I certainly
>>>>> haven't edited that file.
>>>>> Allin Cottrell
>>>>
>>>> Exactly. That's as expected.
>>>> When you run "make" it changes gnuplot_date[] in version.c file to
>>>> reflect
>>>> the most recently modified date. So if you later update from CVS it
>>>> sees
>>>> that your local copy of version.c is different from the base copy in
>>>> CVS.
>>>
>>> OK, I see. And I don't think this is a big deal. But isn't it
>>> sort of a principle of version control to operate a strict
>>> separation between files that are supplied from the repository
>>> (and hence are, in a sense, "read-only") and files that are
>>> automatically generated in the course of a build? Gnuplot's
>>> version.c seems to cross that line.
>>
>> This is sort of the assumption I made and hence the confusion. Maybe
>> it would be better to not do the "mv" step of:
>>
>> sed -e '/^const char gnuplot_date/ s/"[^"]*"/"2013-08-06 "/' \
>> version.c > version.ct;
>> mv version.ct version.c
>>
>> and just compile the derivative file. If that were the case, then my
>> build outside the source tree would have failed because version.ct
>> would not appear. I suppose the intent here is to allow building to
>> proceed if the user doesn't have "sed" on their system, for example.
>>
>> Are you building outside of the source tree? Perhaps we are running
>> into the same issue.
>
> I build gnuplot in its own source tree, so that's not the issue for me.
>
> I just tried a CVS update and build, and this time it worked fine,
> showing the current date. Maybe something extraneous caused a problem
> before, but it seems to me there's a certain brittleness here.
>
> Allin Cottrell

OK.

I still am definitely seeing that if I build outside the source tree the 
version isn't working properly.

The ./configure process will create a Makefile inside the build 
directory.  Say I have:

gnuplot/gnuplot/src
gnuplot/build1/src

(gnuplot/build1 is where I run ./configure) then I see

gnuplot/build1/src/Makefile

after ./configure.  If I look at that Makefile, I see:

EXTRA_DIST = GNUmakefile Makefile.maint NeXT OpenStep README \
genopt.com gnuplot.opt x11.opt linkopt.vms \
makefile.all makefile.awc os2 win \

Could it be that make is expecting to find

gnuplot/build1/src/Makefile.maint

when actually that file is located in the src tree

gnuplot/gnuplot/src/Makefile.maint

?  The make process would have to reorient itself to the source tree src 
directory somehow to run that sed script inside Makefile.maint.

Dan