With cmake, how would you disable in-source builds?

Question

I want to disallow people from cluttering our source tree with generated CMake files... and, more importantly, disallow them from stepping on existing Makefiles

Answer 1

For those on Linux:

add to top-level CMakeLists.txt:

set(CMAKE_DISABLE_IN_SOURCE_BUILD ON)

create a file 'dotme' in your top-level or add to your .bashrc (globally):

#!/bin/bash
cmk() { if [ ! -e $1/CMakeLists.txt ] || ! grep -q "set(CMAKE_DISABLE_IN_SOURCE_BUILD ON)" $1/CMakeLists.txt;then /usr/bin/cmake $*;else echo "CMAKE_DISABLE_IN_SOURCE_BUILD ON";fi }

alias cmake=cmk

now run:

. ./dotme

when you try to run cmake in the top-level source tree:

$ cmake .
CMAKE_DISABLE_IN_SOURCE_BUILD ON

No CMakeFiles/ or CMakeCache.txt gets generated.

When doing out-of-source build and you need to run cmake first time just call the actual executable:

$ cd build
$ /usr/bin/cmake ..