RE: Make cvs ignore some changes in files

[Frederic Brehm]

> > From: Christian Andersson [mailto:address@hidden
> > the problem I have is that these files often gets generated
> > when there is nothing changed to them (it is part of some compilation
> > sections) what happens is that I get new generated files that
> > has only
> > one difference, a remark in the file telling when it was generated..

From: Riechers, Matthew W
> Again, why does something generated by a build need to be revision
> controlled?


The generated files don't need to be revision controlled, but they need to 
be available to people or tools who cannot run the tool that generates the 
files. The most convenient way to make the files available is to put them 
into the repository alongside the other files that are also needed. The 
side effect of this is that the files become revision controlled.

I have a similar need where a tool from a real-time OS vendor generates a 
makefile that has embedded path information. Compiling and linking don't 
require the tool if the makefile is available, but the path information has 
to be adjusted if the base directory is different. The vendor tool (a 
project builder GUI) does not work well in an automated build script. 
Therefore, the automated build scripts that I use for creating a release 
requires the generated makefile, but appropriately modified.

My solution was to write a simple program (sed did the job well) that 
changed the generated makefile into a canonical form. I store the canonical 
form in the repository under a different name: Makefile.cache.

The build procedure manages the local makefile.

 - If the local makefile does not exist, then the build procedure
   creates it from Makefile.cache and updates the date of the local
   copy of Makefile.cache (with touch).

- If the local makefile has changed (test that it is newer than
  Makefile.cache), then the procedure creates the canonical form
  and compares it to Makefile.cache (with cmp).

--- If the two files are the same then the date of the local copy
    of Makefile.cache is updated (with touch).

--- If these are different, then Makefile.cache is replaced with
    the new version. The next cvs commit will commit the new
    Makefile.cache along with any new or changed source files.

Fred

_____________________________________________________________________
Fred Brehm, Sarnoff Corporation, address@hidden
http://www.sarnoff.com/digital_video_informatics/vision_technology/index.asp