[llvm] t[Github] Add initial version of precommit checks (PR #80951)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/80951

This patch adds an initial version of the LLVM precommit checks. These checks should be reasonably performant (full test cycle in ~30 minutes with a fully warm cache, ~80 minutes with a completely cold cache) and should catch regressions within LLVM.

This is mainly intended to test the scalability of the current design and to start eliminating issues before we begin to scale to other subprojects.

>From 3b3addd0fcd808d15172f55e567ae93581dea882 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <agrossman154 at yahoo.com>
Date: Sat, 20 Jan 2024 10:10:10 +0000
Subject: [PATCH] [Github] Add initial version of precommit checks

This patch adds an initial version of the LLVM precommit checks. These
checks should be reasonably performant (full test cycle in ~30 minutes
with a fully warm cache, ~80 minutes with a completely cold cache) and
should catch regressions within LLVM.

This is mainly intended to test the scalability of the current design
and to start eliminating issues before we begin to scale to other
subprojects.
---
 .github/workflows/precommit.yaml | 47 ++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 .github/workflows/precommit.yaml

diff --git a/.github/workflows/precommit.yaml b/.github/workflows/precommit.yaml
new file mode 100644
index 0000000000000..8285a19b684f3
--- /dev/null
+++ b/.github/workflows/precommit.yaml
@@ -0,0 +1,47 @@
+name: "Precommit tests"
+
+permissions:
+  contents: read
+
+on:
+  pull_request:
+    branches:
+      - main
+    paths:
+      - '.github/workflows/precommit.yaml'
+      - 'llvm/**'
+
+jobs:
+  build-llvm:
+    name: "Build and test LLVM"
+    runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/llvm/ci-ubuntu-22.04:latest
+    steps:
+      - name: Fetch LLVM sources
+        uses: actions/checkout at v4
+        with:
+          fetch-depth: 1
+      - name: Setup ccache
+        uses: hendrikmuhs/ccache-action at v1
+        with:
+          max-size: 500M
+          variant: sccache
+          key: precommit-linux
+      - name: Configure LLVM
+        run: |
+          cmake -B llvm-build -GNinja \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DCMAKE_C_COMPILER_LAUNCHER=sccache \
+            -DCMAKE_CXX_COMPILER_LAUNCHER=sccache \
+            -DLLVM_ENABLE_ASSERTIONS=ON \
+            -DCMAKE_C_COMPILER=clang \
+            -DCMAKE_CXX_COMPILER=clang++ \
+            -DLLVM_LIT_ARGS="-v --no-progress-bar" \
+            ./llvm
+      - name: Build LLVM
+        run: |
+          ninja -C llvm-build llvm-test-depends
+      - name: Check LLVM
+        run: |
+          ninja -C llvm-build check-llvm