static and shared internal dependencies

[bruchar1]

My project uses a lot of internal libraries, and I use declare_dependency to express the transitive dependencies between those libraries. Normally, all the dependencies are shared libraries. However, my project have plugin libraries, that depend on the same common libraries, but I want to link statically, because I may update a plugin in an installation without updating the executable and all its shared libraries.

How can I express the fact that a dependency can be either a static library depending on other static libraries, or a shared library, depending on shared libraries?

What I'd like could be, for example, to have a dependency on a both_libraries target, and to select the right version (static or shared) or the lib and of all its dependencies. Should we have a declare_both_dependency or something like that to achieve this? Or is there a simpler way? Because, actually, I need to duplicate a lot of code in my meson.build files...

[xclaesse]

This is a common issue that I think we need to find a solution. Typically a library project does:

l = library()
dep = declare_dependency(link_with: l)

Now if building with --default-library=both, or if using both_libraries() directly, using dep will always use the shared library. It would be nice to add dep.as_static() that recursively crawl all link_with and if it finds any BothLibraries, replace it with its StaticLibrary part. This would be similar to as_link_whole() we already have: https://mesonbuild.com/Reference-manual_returned_dep.html#depas_link_whole.

[xclaesse]

I've been wanting something like this to allow building GStreamer shared plugins and gst-full (a shared library that static link all libs and plugins) at the same time.

[bruchar1]

#12632 should provide a solution for this.