ci: Adds MacOS Bazel Builder

.github/workflows/github-actions-macos-bazel.yml

@@ -0,0 +1,48 @@
+name: Build on macOS
+on:
+  push:
+    branches:
+      - master # Updated to strictly track master
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  Mac-Build:
+    runs-on: macos-latest
+    steps:
+      - name: Setup xcode
+        uses: maxim-lobanov/setup-xcode@v1
+        with:
+          xcode-version: latest-stable
+
+      - name: Check out repository code
+        uses: actions/checkout@v4
+        with:
+          submodules: 'recursive'
+
+      # 1. RESTORE: All jobs (PRs, manual runs, master) get to read the cache
+      - name: Restore Bazel Disk Cache
+        uses: actions/cache/restore@v4
+        with:
+          path: ~/.cache/bazel-disk-cache
+          key: ${{ runner.os }}-bazel-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-bazel-
+
+      - name: Install Bazelisk
+        run: brew install bazelisk
+
+      - name: Build OpenROAD
+        run: |
+          bazelisk build \
+            --disk_cache=~/.cache/bazel-disk-cache \
+            --experimental_disk_cache_gc_max_size=5G \
+            --//:platform=gui //:openroad
+
+      # 2. SAVE: Only executes if this is a push/merge directly to the master branch
+      - name: Save Bazel Disk Cache
+        if: github.ref == 'refs/heads/master' && github.event_name == 'push'
+        uses: actions/cache/save@v4
+        with:
+          path: ~/.cache/bazel-disk-cache
+          key: ${{ runner.os }}-bazel-${{ github.sha }}