How to Explicitly specify cmake to process a different .txt file

Usage
#1

Hi,
Is it possible to have two List.txt files , i,e, CMakeLists1.txt and CMakeLists2.txt in a single directory and while compiling is it possible to inform cmake to consider CMakeLists2.txt for further process ? If yes what is flag should be used ?

Regards
Madhu

#2

No, it is not possible. Only files named CMakeLists.txt are considered when command add_subdirectory() is evaluated.

But you can manage similar behavior with include() command and CMake command line argument:

# file CMakeLists.txt
...
#if (INCLUDE_EXTRA_CMAKELISTS)
  include (${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists2.txt)
#endif()

If you want to process extra file:

cmake -DINCLUDE_EXTRA_CMAKELISTS=ON ...
#3

@marc.chevrier Thanks for that.

Suppose i have only one directory with CMakeLists.txt and CMakeLists1.txt

So in the command line can i do something like cmake --CMakeList1.txt … instead of the default CMakeLists.txt ?

#4

Not at all. Option -C is to populate the cache (file CMakeCache.txt).

Again, there is no way to use alternate names to CMakeLists.txt.

#5

OK , i should be thinking alternate way to deal the requirement.

Thanks Marc.

#6

In situations where I want to automatically choose the Generator (say Ninja vs. Make) or other things that I can or cannot do within CMakeLists.txt, I use ctest -S script.cmake scripts. An example .cmake script I use across many projects is https://github.com/geospace-code/h5fortran/blob/master/setup.cmake.

  • looks for new-enough Ninja first, with Make fallback
  • allows user to type single command to build and test
  • control compiler preference order
  • run tests in parallel

These are all doable by other means, but this is a single command that new users don’t have to be concerned with the details if it works.