Merge llvmorg-22.1.0 into sycl_rel-7_0

Author: sarnex

.ci/buildbot/README.md

@@ -0,0 +1,49 @@
+# ScriptedBuilder Buildbot Workers
+
+This directory contains code shared by LLVM Buildbot workers. The typical
+pipeline of a ScriptedBuilder-based builder is as follows.
+
+1. A commit is pushed to [main](https://github.com/llvm/llvm-project/tree/main)
+
+2. The [Buildbot master](https://lab.llvm.org/) polls the repository and finds
+   new commits. It schedules build requests on every relevant worker.
+   Alternatively, a build request of a specific llvm-project commit can be
+   created using the "Force Build" or "Rebuild" buttons.
+
+3. When a worker is ready, the master sends the build steps determined by
+   [ScriptedBuilder](https://github.com/llvm/llvm-zorg/blob/main/zorg/buildbot/builders/ScriptedBuilder.py)
+   to the worker.
+
+4. The checkout step checks out llvm-project commit into a directory named
+   `llvm.src` on the worker.
+
+5. The annotate step executes a predefined Python script from the llvm-project
+   source tree on the worker. Its working directory is an initially empty
+   sibling directory named `build`. The argument `--workdir=.` is passed to
+   override the default build directory (which is different to avoid
+   accidentally spilling clutter into the cwd)
+
+6. The script is expected to use the utilities from
+   [`worker.py`](https://github.com/llvm/llvm-project/blob/main/.ci/buildbot/worker.py)
+   to build LLVM. The `with w.step("stepname"):` pattern is used to visually
+   separate additional steps in the [Buildbot GUI](https://lab.llvm.org/).
+
+
+## Reproducing Builds
+
+Users can execute the worker script directly to reproduce a build problem with
+a worker using the llvm-project source tree in which it is located. By default
+it will use a new directory with `.workdir` suffix (so it can be
+`.gitignore`-ignored) next to the script as build directory.
+
+The ScriptedBuilder system tries to keep all worker/build settings within the
+script, but some parameters can be overridden using command line parameters.
+For instance, `--jobs` overrides the Ninja and llvm-lit `-j` argument that the
+worker would use. Script should be written to honor these overrides where they
+apply, and may also add additional ones.
+
+See
+[`worker.py`](https://github.com/llvm/llvm-project/blob/main/.ci/buildbot/worker.py)
+or a
+[reference script](https://github.com/llvm/llvm-project/blob/main/polly/polly-x86_64-linux-test-suite)
+for further details.