[llvm] [docs] Strengthen our quality standards and connect AI contribution policy to it (PR #154441)

[Eli Friedman via llvm-commits]

================
@@ -1458,23 +1497,66 @@ permission.
 AI generated contributions
 --------------------------
 
+LLVM's policy on AI-assisted tooling is fundamentally liberal -- We want to
+enable contributors to use the latest and greatest tools available. Our policy
+guided by two major concerns:
+
+1. Ensuring that contributions do not contain copyrighted content.
+2. Ensuring that contributions are not burdensome and exceed our `quality`_ bar.
+
 Artificial intelligence systems raise many questions around copyright that have
 yet to be answered. Our policy on AI tools is guided by our copyright policy:
 Contributors are responsible for ensuring that they have the right to contribute
 code under the terms of our license, typically meaning that either they, their
 employer, or their collaborators hold the copyright. Using AI tools to
 regenerate copyrighted material does not remove the copyright, and contributors
 are responsible for ensuring that such material does not appear in their
-contributions.
-
-As such, the LLVM policy is that contributors are permitted to use artificial
-intelligence tools to produce contributions, provided that they have the right
-to license that code under the project license. Contributions found to violate
-this policy will be removed just like any other offending contribution.
-
-While the LLVM project has a liberal policy on AI tool use, contributors are
-considered responsible for their contributions. We encourage contributors to
-review all generated code before sending it for review to verify its
-correctness and to understand it so that they can answer questions during code
-review. Reviewing and maintaining generated code that the original contributor
-does not understand is not a good use of limited project resources.
+contributions. Contributions found to violate this policy will be removed just
+like any other offending contribution.
+
+Recent improvements in AI-assisted tooling have made it easy to generate large
+volumes of code and text with little effort on the part of the contributor. This
+has increased the asymmetry between the work of producing a contribution, and
+the work of reviewing the contribution. In order to protect the time and
+attentional resources of LLVM project maintainers, the onus is on contributors
+to justify why their contributions are not burdensome and exceed our `quality`_
+bar. Contributors who repeatedly send low-quality contributions to our project
+will be subject to escalating moderation actions and eventually a project ban.
----------------
efriedma-quic wrote:

Maybe we should explicitly state that the CoC committee (or maybe area teams) can place temporary restrictions on a person making pull requests or other contributions.  Like, a limit of one open pull request at a time, or no AI-generated bug reports, or whatever we think is appropriate based on the pattern.  And then violating a temporary restriction is a CoC violation which can lead to a general ban.  (So we wouldn't directly ban people under this policy for low-quality contributions; we would only ban people for violating a temporary restriction.)

The CoC committee did this once before (https://discourse.llvm.org/t/llvm-code-of-conduct-transparency-report-july-15-2023-july-15-2024/82687#p-332791-report-3-a-user-is-submitting-a-very-large-number-of-low-quality-pull-requests-17), although it wasn't backed by any formal policy at the time.

https://github.com/llvm/llvm-project/pull/154441