How to tell cmake to generate different default targets for out-of-source-builds?

Question

How can I write a CMakeLists.txt file that accepts different out-of-source builds? I'm not talking about Debug and Release, but more about something like one build for remote testing one for local testing, etc.

For example: If I go into the build_local build directory and run make I want to have the sources compiled for local configration. If I run make in the build_production build directory I want to compile the sources using a different configuration. I understand that out of source builds are what I need. I just don't quite understand how to:

tell cmake what kind of configuration to generate (e.g., cd build_local; cmake -D local?)
how to write a CMakeLists.txt file in a way that it generates different default target (i.e. make all or make) depending on the configuration

Has someone an example or a link to appropriate documentation?

Thanks!

You can have a build directory for each configuration. But you have to do it manually. — usr1234567, Jul 10 '15 at 11:14

score 2 · Accepted Answer · answered Jul 10 '15 at 11:32

2

Using if command you can fill default target(and others) with different meanings, dependent of configuration.

CMakeLists.txt:

...
option(LOCAL "Build local-testing project" OFF)
if(LOCAL)
    add_executable(program_local local.c)
else()
    add_executable(program_remote remote.c)
endif()

local build:

cd build_local
cmake -DLOCAL=ON ..
make
...

remote build:

cd build_remote
cmake ..
make

In if branches you can use even different add_subdirectory() commands, so your configured project may completely differ for different configurations.

answered Jul 10 '15 at 11:32

Tsyvarev

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Thank you, that was what I was looking for One question remains though, how do I set the default target? Assuming I have a few custom targets (i.e. via `add_custom_target` or `add_custom_command`) and I want to make one of them the default for `make all` depending on the configuration? Thanks. – Bastian Venthur Jul 10 '15 at 11:45
1

`add_custom_target(local_target ${LOCAL_TARGET_TYPE} ...)`. `LOCAL_TARGET_TYPE` should be set to `ALL` if you want it to be executed with `make all`. Otherwise it may be leaved undefined. – Tsyvarev Jul 10 '15 at 12:03

How to tell cmake to generate different default targets for out-of-source-builds?

1 Answers1