[llvm] [Github][Bazel] Add Workflow to Run Bazel Build (PR #165071)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/165071

This patch adds a job to the bazel checks workflow to run the bazel build/test. This patch only tests a couple projects just to get things going. The plan is to expand to more projects eventually and setup a GCS bucket for caching so jobs complete quickly by using cached artifacts.

This should add minimal load to the CI given the low frequency of bazel PRs, and especially when we enable GCS based caching due to bazel's effective use of caching. Google is also sponsoring the Linux Premerge CI and is interested in having premerge bazel builds which is why it makes sense to do premerge testing of this alternative build system.

>From 9697dab0ff62851305569b1489d81045334b74b2 Mon Sep 17 00:00:00 2001
From: Aiden Grossman <aidengrossman at google.com>
Date: Sat, 25 Oct 2025 04:15:05 +0000
Subject: [PATCH] [Github][Bazel] Add Workflow to Run Bazel Build

This patch adds a job to the bazel checks workflow to run the bazel
build/test. This patch only tests a couple projects just to get things
going. The plan is to expand to more projects eventually and setup a GCS
bucket for caching so jobs complete quickly by using cached artifacts.

This should add minimal load to the CI given the low frequency of bazel
PRs, and especially when we enable GCS based caching due to bazel's
effective use of caching. Google is also sponsoring the Linux Premerge
CI and is interested in having premerge bazel builds which is why it
makes sense to do premerge testing of this alternative build system.
---
 .github/workflows/bazel-checks.yml | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/.github/workflows/bazel-checks.yml b/.github/workflows/bazel-checks.yml
index 65d51649dd9e7..7890789aa03c5 100644
--- a/.github/workflows/bazel-checks.yml
+++ b/.github/workflows/bazel-checks.yml
@@ -30,3 +30,26 @@ jobs:
       - name: Run Buildifier
         run: |
           buildifier --mode=check $(find ./utils/bazel -name *BUILD*)
+  
+  bazel-build:
+    name: "Bazel Build/Test"
+    runs-on: llvm-premerge-linux-runners
+    if: github.repository == 'llvm/llvm-project'
+    steps:
+      - name: Fetch LLVM sources
+        uses: actions/checkout at 08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        # TODO(boomanaiden154): We should use a purpose built container for this. Move
+        # over when we have fixed the issues with using custom containers with Github
+        # ARC in GKE.
+      - name: Setup System Dependencies
+        run: |
+          sudo apt-get install -y libmpfr-dev pfm
+          sudo curl -L https://github.com/bazelbuild/bazelisk/releases/download/v1.27.0/bazelisk-amd64.deb > /tmp/bazelisk.deb
+          sudo apt-get install -y /tmp/bazelisk.deb
+          rm /tmp/bazelisk.deb
+      - name: Build/Test
+        working-directory: utils/bazel
+        run: |
+          bazel test --config=ci @llvm-project//llvm/... \
+            @llvm-project/clang/... \
+            @llvm-project/mlir/...