Add clang-tidy external examples

[MichelleCDjunaidi]

Motivation: Clang has a page where they list out external examples: https://clang.llvm.org/docs/ExternalClangExamples.html. While I was writing an out-of-tree clang-tidy plugin, I wanted such a page to exist also as it would have helped development. The example repo listed in the proposed page has been useful for me.

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[llvmbot]

@llvm/pr-subscribers-clang-tidy

@llvm/pr-subscribers-clang-tools-extra

Author: None (MichelleCDjunaidi)

Changes

Motivation: Clang has a page where they list out external examples: https://clang.llvm.org/docs/ExternalClangExamples.html. While I was writing an out-of-tree clang-tidy plugin, I wanted such a page to exist also as it would have helped development. The example repo listed in the proposed page has been useful for me.

---

Full diff: https://github.com/llvm/llvm-project/pull/106675.diff

1 Files Affected:

• (added) clang-tools-extra/docs/clang-tidy/ExternalClang-TidyExamples.rst (+31)

diff --git a/clang-tools-extra/docs/clang-tidy/ExternalClang-TidyExamples.rst b/clang-tools-extra/docs/clang-tidy/ExternalClang-TidyExamples.rst
new file mode 100644
index 00000000000000..735f99b30c7b7d
--- /dev/null
+++ b/clang-tools-extra/docs/clang-tidy/ExternalClang-TidyExamples.rst
@@ -0,0 +1,31 @@
+=======================
+External Clang-Tidy Examples
+=======================
+
+Introduction
+============
+
+This page provides examples of what people have done with clang-tidy that 
+might serve as useful guides (or starting points) to develop your own checks. 
+They may be helpful even for necessary things such as how to write CMakeLists.txt 
+for an out-of-tree plugin of clang-tidy checks.
+
+If you know of (or wrote!) a tool or project using clang-tidy, please post on
+`the Discourse forums (Clang Frontend category)
+<https://discourse.llvm.org/c/clang/6>`_ to have it added.
+(or if you are already a clang-tidy contributor, feel free to directly commit
+additions). Since the primary purpose of this page is to provide examples
+that can help developers, generally they must have code available.
+
+As clang-tidy shares C++ AST Matchers with Clang diagnostics, `External Clang Examples`_ 
+may also be useful to look at.
+
+.. _External Clang Examples: https://clang.llvm.org/docs/ExternalClangExamples.html
+
+https://clang.llvm.org/docs/ExternalClangExamples.html
+
+List of projects and tools
+==========================
+
+`<https://github.com/coveooss/clang-tidy-plugin-examples/tree/main>`_
+    "This folder contains clang-tidy plugins."
\ No newline at end of file

[5chmidti]

Great idea to add this. Although, we should be careful to not end up with abandoned projects. I sampled three from the page in Clang, and they had their last activity at around ~10 years. At that point, API's have changed. Either way, adding external examples is a good idea IMO
(I should clean up my external clang-tidy template that's still private :) )

[MichelleCDjunaidi]

Side note, but I don't have write permissions, so once the PR looks great feel free to land it on my behalf.

[MichelleCDjunaidi]

@EugeneZelenko @5chmidti Thoughts on the fixed formatting? I followed index.rst convention.

[SimplyDanny]

One more nit. Otherwise looks good to me.

[MichelleCDjunaidi]

I will need help to merge this once approved. Thank you so much!

[MichelleCDjunaidi]

@5chmidti @SimplyDanny can anyone help merge this into main?

[SimplyDanny]

There is an error in doc generation. Is it caused by the new file being added? Is there a configuration that needs adaption?

[MichelleCDjunaidi]

I asked in the forums. https://discourse.llvm.org/t/fix-error-in-upstream-doc-generation-due-to-addition-of-new-section/81368. Hopefully someone knows what to add...

[HerrCai0907]

You can add toctree in clang-tools-extra/docs/clang-tidy/index.rst
example commit: https://reviews.llvm.org/D54945

[MichelleCDjunaidi]

Well, the documentation builds now thanks to @HerrCai0907. Does it look fine @SimplyDanny @5chmidti ?

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