MantisBT - CMake

View Issue Details

Project

Category

View Status

Date Submitted

Last Update

0014650

CMake

public

2013-12-16 03:22

2016-06-10 14:31

Reporter

Lars

Assigned To

Kitware Robot

Priority

normal

Severity

minor

Reproducibility

always

Status

closed

Resolution

moved

Platform

OS Version

Product Version

CMake 2.8.12

Target Version

Fixed in Version

Summary

0014650: Depend.make content

Description

Building our software is very slow using CMake 2.8.12.1 and VS2005. Debugging this issue I discovered the several of the depend.make files are huge. One example is a depend.make file that is roughly 10 MB. It appears the dependency scanner in cmake does not take into account preprocessor directive, so including one boost header in a translation unit can cause this translation unit to depend on several 100s of boost files. In our case, each translation unit dependent on 1000 or more boost header files.

Adding the following code solved the issue for boost;
include_regular_expression("^([^b]|b[^o]|bo[^o]|boo[^s]|boos[^t]|boost[^/]).*$")
(this line reduced the build time by more than 50%)

This is is a limited solution because it only works on part of the header path.
We have other third party tools that we would like to filter out of the depend.make file, for instance Qt. How do we accomplish that?

A suggestion from Nils Gladitz;
"Maybe CMake could filter out includes in system directories (like gcc -MM does). System directories in this case could be directories added with e.g. include_directories(SYSTEM)."

Steps To Reproduce

Additional Information