From: Dmitry Potapov <dpotapov@gmail.com>
Date: Fri, 17 Apr 2009 17:24:51 GMT
Subject: Re: integrating make and git
Message-ID: <37fcd2780904171024v1b65d621q2725858e76358c36@mail.gmail.com>
In-Reply-To: <8763h5qazf.fsf@krank.kagedal.org>

On Thu, Apr 16, 2009 at 12:05 PM, David Kågedal <davidk@lysator.liu.se> wrote:
> Ben Jackson <ben@ben.com> writes:
>
>> E R <pc88mxer <at> gmail.com> writes:
>>
>>> Now suppose that making 'lib1' only depends on the source code in a
>>> certain directory. The idea is to associate the hash of the source
>>> directory for lib1 with its the derived files. Make can check this to
>>> determine if the component really needs to be rebuilt.
>>
>> ClearCase has "wink-ins" which are very much like this.  It knows that a given
>> object was produced from a certain set of sources with a particular command.
>> When someone wants to recreate that object (not even necessarily the original
>> builder) it can "wink in" the result.  Typically a brand new "view" (a ClearCase
>> working directory) build will consist of winking in a ton of objects rather than
>> building anything.  I'm not sure how much of this is due to cleverness in
>> clearmake and how much is due to the view being implemented as a virtual
>> filesystem (which can see every repository file being read as part of a build).
>
> It very much depends on implementing its own file system, since it
> otherwise would have no idea what the *real* build dependencies are.

Not necessary... You can use LD_PRELOAD to intercept 'open' (and all
needed syscalls), but it works only on those platforms where LD_PRELOAD
is supported.  IIRC, there was some tool that did this, but I have never
used it.  I am pretty happy with ccache :)

Dmitry