Hello,
As the guys from MS have said, a 700,000 lines of code is actually not very
much at all. I can rebuild a much larger suite of projects from scratch in
about 40 minutes on a reasonable, but not super high-end, machine. Single
processor, hyper-threaded, RAID 1 drive (redundant). So you might simply
consider getting a machine that has a fast drive. I found that with this
RAID 1 setup, things became much, much faster. With RAID 0 (striping) it
may be even faster still. (Perhaps have I have RAID 0 and 1 backwards here,
I can never remenber, I have the redundant drive version).
However, you will get a huge increase in speed from using precompiled
headers correctly, as one of the posters mentioned. I think we probably got
a 50-1 improvement in time building some projects from using precompiled
headers.
We don't have any projects with 2000 source files (50-100 is largest for
us), so your use of precompiled headers may need to be slightly different
than ours, but I can give you a snapshot of how we use it.
In each project that warrents it, we create a file "precomp.h" into which we
place all of the windows and system headers (crt / stdc++ etc.) that are
reasonable for the project. We also place headers in there from our own
suite of libraries that are being used in the project being built. If
appropriate, some project local headers may also be placed there, but only
if they are never (or very very rarely) changing.
Create a file "precomp.cpp" that has one line of text - #include
"precomp.h". Add this file to your project.
In every single one of your files being compiled (i.e. all of your ".cpp"
files), insert #include "precomp.h" as the very first non-comment text line.
Change your project settings so that "Use precompiled headers (/Yu)" is
selected as the default. Indicate that "precomp.h" is the header to use.
Change then the file specific setting for "precomp.cpp" to be "Create
precompiled header (/Yc)". Again specify "precomp.h" as the appropriate
header.
That should be it. It might be painful to inser that #include "precomp.h"
in every one of your source files, but it is a one time process. For a
project with 2000 files it may be appropriate to have a number of different
precompiled headers, but these .pch files are quite large and if the
compiler has to switch from using one to using another between different
translation units, that may slow it down because of disk access. Once the
..pch file is loaded and in the disk cache, it is very fast retrieving it,
which is a big win.
I would also though seriously consider breaking up your project into pieces,
as 2000 source files in one project seems excessive. If you look at large
library suites that people have out there (GDAL comes to mind) you will see
I think that mostly things are broken up into more managable sized
collections of files per project (.dll or .lib).
Anyway bottom line is I would look first to these other solutions than
assuming that the dependency walker of DevStudio is malfunctioning.
Whenever I have thought there was something going wrong with it in the past,
I have come to realize that there was some dependency I wasn't considering.
Good luck.
-Eric Twietmeyer
PS However, I do have a gripe about CSharp projects. They do always rebuild
as far as I can tell, there doesn't seem to be a notion for these projects
that all targets are up to date and don't need to be touched. They simply
always rebuild completely. Don't know why....
"Andy Capon" <acapon@sgi.com> wrote in message
news:f2ab91d8.0409230800.dec5b98@posting.google.co m...[color=blue]
> Hi There,
>
> We have a medium size project about 2000 source files and 700,000
> lines of code, as you can imagine this takes some time to rebuild all.
>
> Now our problem is that we have a code generator we have developed
> that updates some of our classes, as an example lets say I update 50
> files. When we do a build the ide builds nearly all of the source
> files while we swear and then twiddle our thumbs for a couple of
> hours.
>
> Its almost as if it says "well alot of files have changed I will just
> rebuild everything".
>
> Does anyone know why this happens?
>
> We are useing 2003 but 2002 did it as well.
>
> As a side point I have noticed that the upcomeing version can use
> multiple processors to build, will this work within one project as
> then we could at least halve the time. We can build it on uour 24
> processor irix box in about 10 minutes!
>
> Any help would be much apreciated.
>
> Well back to twidling my thumbs.
>
> Cheers
>
> Andy[/color]
