[question] How to generate merged CppInfo data (libs, libdirs etc.) for a given package component? (Conan 2.0)

[db4]

What is your question?

Say, I require "opencv/4.5.3" and need to fully resolve includedirs, libs, and libdirs for opencv::opencv_imgproc component. For the entire dependency, it's quite easy: cpp_info = self.dependencies["opencv"].cpp_info.aggregated_components() Edit: not exactly, see the corrected code below.

Have you read the CONTRIBUTING guide?

• [ ] I've read the CONTRIBUTING guide

[memsharded]

I think using self.dependencies["opencv"].cpp_info.components["opencv_imgproc"] you get access to that information, is that what you are looking for?

[db4]

@memsharded I need to walk all dependencies recursively and create the merged CppInfo. For a package, it can be done with

        res = CppInfo(root)
        deps = root.dependencies.host.topological_sort
        deps = [dep for dep in reversed(deps.values())]
        for dep in deps:
            dep_cppinfo = dep.cpp_info.aggregated_components()
            res.merge(dep_cppinfo)

but how to do the same for a package component? (in the example above for opencv::opencv_imgproc)

[memsharded]

Hi @db4

Sorry this was not followed up back then.

it is not very clear what would be the question. If you want all the components aggregated, you can use .aggregated_components, if you want an individual component, then accessing that component .components["opencv_imgproc"] would get access to the data.

[db4]

Hi @memsharded

I needed aggregated dependencies (e.g. all libs and headers including transitive ones) for a given component. Since then I've done without them, but they could be useful.

[memsharded]

Maybe you need the merge() method in https://docs.conan.io/2/reference/tools/cpp_info.html#aggregating-information-in-custom-generators?

You can iterate self.dependencies and merging all the cpp_info from those dependencies. If you want to limit to a subset of all dependencies for that given component, that subset can be computed from the .requires of that component.

Doesn't sound trivial, but it looks possible. Have you tried that?

[db4]

Not yet. The question is old enough, I managed to get by with PkgConfigDeps generator. I close the issue right now and may follow your advice in the future. Thanks!