[llvm-core] bring package up to date. Support for Conan 2.

[planetmarshall]

Specify library name and version: llvm-core/*

Attempt to bring the llvm-core recipe up to date. Includes contributions from @jusito and #17509. Fixes #20339

Note that I have opted not to add the latest version (18.1.3) as part of this PR, as the existing recipe needed updating and is already quite complex. I (or someone else) will add the latest version as a followup.

---

• I've read the contributing guidelines.
• I've used a recent Conan client version close to the currently deployed.
• I've tried at least one configuration locally with the conan-center hook activated.

[github-actions]

🤖 Beep Boop! This pull request is making changes to 'recipes/llvm-core//'.

👋 @Hopobcn @paulharris you might be interested. 😉

[jwillikers]

Woot!

[AbrilRBS]

@planetmarshall sorry about that - llvm takes quite a long time to compile - I see that the compilation is now done and the results posted and they are passing, yay!! I'll get a review going for monday, thanks a lot for your patience and for the contribution in the first place, we really aprpeciate it :)

[planetmarshall]

@planetmarshall sorry about that - llvm takes quite a long time to compile - I see that the compilation is now done and the results posted and they are passing, yay!! I'll get a review going for monday, thanks a lot for your patience and for the contribution in the first place, we really aprpeciate it :)

Thanks, I also appreciate the efforts of the CCI team.

[jacobfriedman]

@jusito possible to review this week? I opted not to use llvm-core and your PR instead (llvm-16) but am eagerly waiting on this PR and can help update/test/review the later PRs.

@jcar87 It would be a big plus to be able to simply pull down transparent/conan-compiled compilers in Dockerfiles e.g. https://github.com/conan-io/conan-docker-tools/blob/master/modern/clang/Dockerfile

[Croydon]

Why is it not required anymore?

[planetmarshall]

Because graphviz is not used to model component dependencies, as noted in the comment.

[planetmarshall]

To clarify further - the original recipe used graphviz output which was then parsed and sanitized to generate component dependencies. Instead of doing this I opted to just use the information that LLVM already outputs in its CMake files, I thought this was more robust since the best source of cmake dependencies is cmake itself rather than going via graphviz and back again.

[conan-center-bot]

Conan v1 pipeline ✔️

All green in build 29 (4c50124dc6d0d84b364e22fbf286363e12cf66e4):

• llvm-core/13.0.0:
  All packages built successfully! (All logs)

• llvm-core/12.0.0:
  All packages built successfully! (All logs)

• llvm-core/11.1.0:
  All packages built successfully! (All logs)

---

Conan v2 pipeline ✔️

Note: Conan v2 builds are now mandatory. Please read our discussion about it.

All green in build 30 (4c50124dc6d0d84b364e22fbf286363e12cf66e4):

• llvm-core/13.0.0:
  All packages built successfully! (All logs)

• llvm-core/12.0.0:
  All packages built successfully! (All logs)

• llvm-core/11.1.0:
  All packages built successfully! (All logs)