can I have toolchain config per sub-project?

[stsp]

Hi!

Currently my project consists of
separate subprojects. But the options
like --native-file and --cross-file seem
to be global. This leads to confusion,
for example meson forces me to
specify cpp compiler in cross-file,
even though the particular subproject
that needs cross-file, doesn't use c++.

Can I specify toolchain configs per
subproject?

[klokik]

No, you cannot. As you mentioned these are global. As I see it, meson tries to decouple environment configuration from subproject build definitions as much as possible.

Consider splitting C++ compiler definitions into a separate cross file an layer it on top of your primary one if you know that you will be building a subproject that requires it. https://mesonbuild.com/Machine-files.html#loading-multiple-machine-files

[stsp]

My primary one already has cpp = 'clang++',
but its native, not cross file.
Meson requires cpp also in cross
file, likely because cross file does not
inherit from native. Given that cross
compilation in my case only needs
nasm (and no C or C++), having to write
C and C++ compilers into a cross file is
more than strange. I split the cross-compilation
into a sub-project which doesn't list c++,
but it is still mixed with the main project
so meson forces me to put C and C++
compilers into a cross file, when neither
is needed.

[stsp]

Maybe meson should support more
descriptive project declarations? Like:
project('my_project', native: ['c', 'c++'], cross: ['nasm'])?