Incorporate Eugene's feedback.

.github/actions/setup-build/action.yml

@@ -1,45 +1,42 @@
 # Copyright 2022 The StableHLO Authors.
 
 # The setup-build action gets everything needed by buildAndTest into the workspace.
-# This checks out the proper revision of the LLVM repository, installs ninja, and sets
-# up the ccache for faster re-compilation.
 name: "Setup build environment (ninja, ccache, llvm, lld)"
 
 inputs:
-  llvm-ref:
+  llvm-version:
     description: |
-      LLVM Commit Ref for checkout and build. Used for ccache value and checkout.
+      LLVM version for checkout and build. Used for ccache value and checkout.
     required: true
 
-
 runs:
-  # Based on https://github.com/llvm/torch-mlir/blob/main/.github/actions/setup-build/action.yml
+  # This is a composite action - has a list of steps to execute.
   using: "composite"
 
   steps:
-  # Checkout llvm at revision specified in input argument.
+  # Checkout llvm at version specified in input argument.
   - uses: actions/checkout@v2
     with:
       repository: llvm/llvm-project
-      ref: ${{ inputs.llvm-ref }}
+      ref: ${{ inputs.llvm-version }}
       path: llvm-project
       fetch-depth: 1
 
   # Get ninja for cmake build.
   - name: Install Ninja
     uses: llvm/actions/install-ninja@55d844821959226fab4911f96f37071c1d4c3268
 
-  # Get LLD
+  # Get LLD - Improves build speed on Linux
   - name: Install LLD
     if: "runner.os == 'Linux'"
     shell: bash
     run: |
       sudo apt-get install -y lld
 
   # Setup C++ caching using ccache.
-  # Cache key is a combination of OS arch and LLVM ref.
+  # Cache key is a combination of OS arch and LLVM version.
   - name: Ccache for C++ compilation
     uses: hendrikmuhs/[email protected]
     with:
-      key: ${{ runner.os }}-stablehlo_build_assets-${{ inputs.llvm-ref }}
+      key: ${{ runner.os }}-stablehlo_build_assets-${{ inputs.llvm-version }}
       max-size: 4G

.github/workflows/buildAndTest.yml

@@ -6,9 +6,9 @@ on:
   pull_request:
     branches: [ main ]
   push:
-    branches: [ main ]
+    branches: [ main, actions ]
   schedule:
-    # Always regenerate once every day
+    # Run buildAndTest workflow once a day
     - cron:  '* 12 * * *'
   workflow_dispatch:
 
@@ -22,7 +22,6 @@ concurrency:
 
 # Build using CMake and run tests.
 # Use Cached LLVM to improve build times.
-# Current setup only builds on linux.
 jobs:
   build-test:
     strategy:
@@ -32,40 +31,35 @@ jobs:
         include:
           - os-arch: ubuntu-x86_64
             os: ubuntu-22.04
-            llvm-build-dir: "$GITHUB_WORKSPACE/llvm-build"
-            stablehlo-build-dir: "$GITHUB_WORKSPACE/build"
           - os-arch: maci-x86_64 
             os: macos-latest
-            llvm-build-dir: "$GITHUB_WORKSPACE/llvm-build-maci"
-            stablehlo-build-dir: "$GITHUB_WORKSPACE/build-maci"
     runs-on: ${{ matrix.os }}
 
     steps:
-
-    # Check out stablehlo repo
-    - name: Checkout stablehlo
+    # Check out StableHLO repo
+    - name: Checkout StableHLO
       uses: actions/checkout@v2
 
-    # Read llvm revision from `build_tools/llvm_version.txt`
-    - name: Get LLVM Revision
-      id: llvm-revision
+    # Read LLVM version from `build_tools/llvm_version.txt`
+    - name: Get LLVM Version
+      id: llvm-version
       shell: bash
       run: |
-        echo "::set-output name=revision::$(cat ${{ github.workspace }}/build_tools/llvm_version.txt)"
+        echo "::set-output name=version::$(cat ${{ github.workspace }}/build_tools/llvm_version.txt)"
 
-    # Check out LLVM, download Ninja, setup ccache
+    # Check out LLVM, and install tools for compilation 
     - name: Setup workspace
       uses: ./.github/actions/setup-build
       with:
-        llvm-ref: ${{ steps.llvm-revision.outputs.revision }}
+        llvm-version: ${{ steps.llvm-version.outputs.version }}
 
     # Configuration for linux
     - name: Configure and Build LLVM os-arch='${{ matrix.os-arch }}'
       shell: bash
       run: |
-        ./build_tools/github_actions/ci_build_llvm.sh "$GITHUB_WORKSPACE/llvm-project/" ${{ matrix.llvm-build-dir }}
+        ./build_tools/github_actions/ci_build_llvm.sh "$GITHUB_WORKSPACE/llvm-project/" "$GITHUB_WORKSPACE/llvm-build"
 
     # Configure for linux
     - name: Build and Test StableHLO os-arch='${{ matrix.os-arch }}'
       run: |
-        ./build_tools/github_actions/ci_build_stablehlo.sh ${{ matrix.llvm-build-dir }} ${{ matrix.stablehlo-build-dir }}
+        ./build_tools/github_actions/ci_build_stablehlo.sh "$GITHUB_WORKSPACE/llvm-build" "$GITHUB_WORKSPACE/stablehlo-build"

.github/workflows/lint.yml

@@ -2,10 +2,9 @@
 
 name: Lint
 
-on: [pull_request]
+on: [pull_request, push]
 
 jobs:
-  # Based on https://github.com/iree-org/iree/blob/main/.github/workflows/lint.yml
   clang-format:
     if: "github.event_name == 'pull_request'"
     runs-on: ubuntu-latest

build_tools/github_actions/ci_build_llvm.sh

@@ -14,7 +14,7 @@
 # limitations under the License.
 
 # This file is similar to build_mlir.sh, but passes different flags for
-# cacheing in GitHub Actions to improve build speeds.
+# caching in GitHub Actions to improve build speeds.
 
 if [[ $# -ne 2 ]] ; then
   echo "Usage: $0 <path/to/llvm> <build_dir>"
@@ -26,36 +26,32 @@ LLVM_SRC_DIR="$1"
 LLVM_BUILD_DIR="$2"
 
 # Check for LLD
-FLAGS=""
-LLD_FLAG="-DLLVM_ENABLE_LLD=ON"
+LLVM_ENABLE_LLD=""
 if command -v lld &> /dev/null
 then
-  echo "lld found, appending flag '$LLD_FLAG'"
-  FLAGS="$LLD_FLAG"
+  LLVM_ENABLE_LLD="-DLLVM_ENABLE_LLD=ON"
+  echo "lld found, compiling with '$LLVM_ENABLE_LLD'"
 else
   echo "lld not found, using default linker"
 fi
 
-# Call cmake
-echo "Using additional flags: '$FLAGS'"
-
 cmake -GNinja \
-  "$FLAGS" \
-  "-B$LLVM_BUILD_DIR" \
   "-H$LLVM_SRC_DIR/llvm" \
+  "-B$LLVM_BUILD_DIR" \
+  -DLLVM_INSTALL_UTILS=ON \
+  "$LLVM_ENABLE_LLD" \
+  -DLLVM_ENABLE_PROJECTS=mlir \
+  -DLLVM_TARGETS_TO_BUILD="X86;NVPTX;AMDGPU" \
+  -DLLVM_INCLUDE_TOOLS=ON \
+  -DLLVM_ENABLE_BINDINGS=OFF \
+  -DLLVM_BUILD_TOOLS=OFF \
+  -DLLVM_INCLUDE_TESTS=OFF \
   -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+  -DLLVM_ENABLE_ASSERTIONS=On \
   -DCMAKE_CXX_COMPILER=clang++ \
   -DCMAKE_CXX_COMPILER_LAUNCHER=ccache \
   -DCMAKE_C_COMPILER=clang \
-  -DCMAKE_C_COMPILER_LAUNCHER=ccache \
-  -DLLVM_BUILD_TOOLS=OFF \
-  -DLLVM_ENABLE_ASSERTIONS=On \
-  -DLLVM_ENABLE_BINDINGS=OFF \
-  -DLLVM_ENABLE_PROJECTS=mlir \
-  -DLLVM_INCLUDE_TESTS=OFF \
-  -DLLVM_INCLUDE_TOOLS=ON \
-  -DLLVM_INSTALL_UTILS=ON \
-  -DLLVM_TARGETS_TO_BUILD="X86;NVPTX;AMDGPU"
+  -DCMAKE_C_COMPILER_LAUNCHER=ccache
 
 # Build LLVM/MLIR
 cmake --build "$LLVM_BUILD_DIR" --target all --target mlir-cpu-runner

build_tools/github_actions/ci_build_stablehlo.sh

@@ -14,7 +14,7 @@
 # limitations under the License.
 
 # This file is similar to build_mlir.sh, but passes different flags for
-# cacheing in GitHub Actions.
+# caching in GitHub Actions.
 
 # This file gets called on build directory where resources are placed
 # during `ci_configure`, and builds stablehlo in the directory specified