Passing the argument to CMAKE via command prompt
MakefileCmakeMakefile Problem Overview
I have a makefile for my project and also I am passing some argument and based on that argument i am seting some flag. I am able to do this . but now I want to do the same using cmake. I have created cmakelist.txt
but I don't know how to pass the argument and check for the argument value in cmakelist.txt
.
Sample of my makefile:
ifeq "$(FAB)" "po"
//setting some flags
else
//setting some iother flag
endif
What is the way to take the argument from command prompt and set flags based on that?
Makefile Solutions
Solution 1 - Makefile
In the CMakeLists.txt file, create a cache variable, as documented here:
SET(FAB "po" CACHE STRING "Some user-specified option")
Source: http://cmake.org/cmake/help/v2.8.8/cmake.html#command:set
Then, either use the GUI (ccmake or cmake-gui) to set the cache variable, or specify the value of the variable on the cmake command line:
cmake -DFAB:STRING=po
Source: http://cmake.org/cmake/help/v2.8.8/cmake.html#opt:-Dvar:typevalue
Modify your cache variable to a boolean if, in fact, your option is boolean.
Solution 2 - Makefile
CMake 3.13 on Ubuntu 16.04
This approach is more flexible because it doesn't constraint MY_VARIABLE to a type:
$ cat CMakeLists.txt
message("MY_VARIABLE=${MY_VARIABLE}")
if( MY_VARIABLE )
message("MY_VARIABLE evaluates to True")
endif()
$ mkdir build && cd build
$ cmake ..
MY_VARIABLE=
-- Configuring done
-- Generating done
-- Build files have been written to: /path/to/build
$ cmake .. -DMY_VARIABLE=True
MY_VARIABLE=True
MY_VARIABLE evaluates to True
-- Configuring done
-- Generating done
-- Build files have been written to: /path/to/build
$ cmake .. -DMY_VARIABLE=False
MY_VARIABLE=False
-- Configuring done
-- Generating done
-- Build files have been written to: /path/to/build
$ cmake .. -DMY_VARIABLE=1
MY_VARIABLE=1
MY_VARIABLE evaluates to True
-- Configuring done
-- Generating done
-- Build files have been written to: /path/to/build
$ cmake .. -DMY_VARIABLE=0
MY_VARIABLE=0
-- Configuring done
-- Generating done
-- Build files have been written to: /path/to/build