I want to create a second file, for example Instructions.txt, and be able to include it’s CMake instructions to the main CMakeLists.txt, for example:
// Instructions.txt
set(MY_VARIABLE, value)
set(MY_SECOND_VARIABLE, 1234)
// CMakeLists.txt
<HERE INCLUDE INSTRUCTIONS.TXT>
// And be able to use those variables, for example
project(MY_VARIABLE)
>Solution :
You usually do that simply by using another cmake.
Contrary to what you might believe, the file extension is different for other file than build files.
Let’s call this file instructions.cmake:
set(MY_VARIABLE, value)
set(MY_SECOND_VARIABLE, 1234)
Then you can include it like this inside your CMakeLists.txt:
include(instructions)
There are some other filename that are important for CMake though.
For example, any file that start with Find then ends with .cmake like FindXYZ.cmake, the XYZ part is assumed to be a package name and in that case you should use find_package(XYZ REQUIRED).