Forcing variable expansion

Code
1

Is there a way to force variable expansion on a string that contains a variable reference?

In my case I have a variable SOME_VAR that is set by the user on the command line and contains a reference to a variable that is defined in the CMake script – something like this:

cmake ... -DSOME_VAR="${SOME_OTHER_VAR}_bar"

And my script defines SOME_OTHER_VAR to be “foo”. But if I then print out SOME_VAR, I still see “${SOME_OTHER_VAR}_bar”, rather than “foo_bar”.

Is there something I can do to trigger variable expansion in SOME_VAR?

2

On the command line, that expansion is going to be controlled by the shell, not CMake. If you want replacement like that, you’ll need a CMake file to do it (maybe via the -C command line flag). But there’s no way to say “defer evaluation of this value until it is needed” in CMake.

3

Not sure what my shell has to do with any of that? I neither expect nor want to perform any expansion “on the command line”.

Anyway, it seems that string(CONFIGURE) does exactly what I wanted.