[CMake] Customize dependencies scanned by CMake

[Dieter Oberkofler]

Thanks' a lot!

 

 

From: David Cole [mailto:david.cole at kitware.com] 
Sent: Monday, January 17, 2011 16:40
To: Dieter Oberkofler
Cc: CMake at cmake.org
Subject: Re: [CMake] Customize dependencies scanned by CMake

 

See this command:
http://cmake.org/cmake/help/cmake-2-8-docs.html#command:include_regular_expr
ession

If you can match many of the "header files that rarely, if ever, change"
with a regular expression based on directory and file name patterns, then
you can reduce the number of entries in the generated makefiles
significantly.


HTH,
David



On Sat, Jan 15, 2011 at 7:57 AM, Dieter Oberkofler
<doberkofler.lists at gmail.com> wrote:

I'm using CMake 2.8.3 using makefiles for the OSX and Windows platform.

I very much like CMake but unfortunately the build performance consistently
causes some problems.

And the main performance problem is the absolutely correct but painfully
slow dependency checking.
In a large (Qt/C++) project a single source file has over 1500 include
dependencies summing up to a "depend.make" file with several million lines.
Almost all (typically 99%) of the include dependencies are not needed in
real life because they come from Qt or other static frameworks but
dramatically slow down the build process.

I do know that CMake offers the /fast option but this removes all
dependencies and although it is 3-5 times faster, manually "optimizing" the
content of "depend.make" makes the build up to 20 times faster.
Why is the /fast option not (at least) as fast as a manually "optimized"
"depend.make"?

Is there a way to:
- customize what includes should be parsed?
- exclude dependency trees?
- limit the recursion level?

or any other option to solve this problem?

Thank you!


_______________________________________________
Powered by www.kitware.com

Visit other Kitware open-source projects at
http://www.kitware.com/opensource/opensource.html

Please keep messages on-topic and check the CMake FAQ at:
http://www.cmake.org/Wiki/CMake_FAQ

Follow this link to subscribe/unsubscribe:
http://www.cmake.org/mailman/listinfo/cmake

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.cmake.org/pipermail/cmake/attachments/20110117/721a33fb/attachment.htm>