[Task] : Add ci for windows build.

Author: sahas3

.github/workflows/ci.yml

@@ -79,3 +79,62 @@ jobs:
         if: ${{ matrix.torch-version == 'nightly' }}
         run: |
           bash build_tools/ci/check_generated_sources.sh
+
+  build-test-windows:
+    strategy:
+      fail-fast: true
+      matrix:
+        torch-version: [nightly]
+    name: Build (Windows, torch-${{ matrix.torch-version }})
+    runs-on: windows-latest
+    defaults:
+      run:
+        shell: bash
+    env:
+      CACHE_DIR: ${{ github.workspace }}\.container-cache
+    steps:
+      - name: "Checking out repository"
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          submodules: true
+
+      - name: Setup workspace
+        uses: ./.github/actions/setup-build
+
+      - name: Enable cache
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4.2.0
+        with:
+          path: ${{ env.CACHE_DIR }}
+          key: build-test-cpp-asserts-windows-${{ matrix.torch-version }}-v2-${{ github.sha }}
+          restore-keys: |
+            build-test-cpp-asserts-windows-${{ matrix.torch-version }}-v2-
+
+      - name: "Configuring MSVC"
+        uses: ilammy/msvc-dev-cmd@0b201ec74fa43914dc39ae48a89fd1d8cb592756 # v1.13.0
+
+      - name: Install python deps (torch-${{ matrix.torch-version }})
+        run: |
+          ./build_tools/ci/install_python_deps.sh ${{ matrix.torch-version }}
+
+      - name: ccache
+        uses: hendrikmuhs/ccache-action@53911442209d5c18de8a31615e0923161e435875 # v1.2.16
+        with:
+          key: ${{ github.job }}-${{ matrix.torch-version }}
+          save: ${{ needs.setup.outputs.write-caches == 1 }}
+
+      - name: Build project
+        run: |
+          cache_dir="${{ env.CACHE_DIR }}" \
+          ./build_tools/python_deploy/build_windows_ci.sh
+
+      - name: Save cache
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4.2.0
+        if: ${{ !cancelled() }}
+        with:
+          path: ${{ env.CACHE_DIR }}
+          key: build-test-cpp-asserts-windows-${{ matrix.torch-version }}-v2-${{ github.sha }}
+
+      # todo: enable when use of `signal` for timeout is enhanced to be platform-agnostic
+      # - name: Integration tests (torch-${{ matrix.torch-version }})
+      #   run: |
+      #     ./build_tools/ci/test_posix.sh ${{ matrix.torch-version }}

build_tools/python_deploy/build_windows_ci.sh

@@ -1,8 +1,30 @@
 #!/usr/bin/env bash
-set -eo pipefail
+set -eu -o errtrace
 
 echo "Building torch-mlir"
 
+cache_dir="${cache_dir:-}"
+this_dir="$(cd $(dirname $0) && pwd)"
+repo_root="$(cd ${this_dir}/../.. && pwd)"
+
+# Setup cache dir.
+if [ -z "${cache_dir}" ]; then
+  cache_dir="${repo_root}/.build-cache"
+  mkdir -p "${cache_dir}"
+  cache_dir="$(cd ${cache_dir} && pwd)"
+fi
+
+echo "Caching to ${cache_dir}"
+mkdir -p "${cache_dir}/ccache"
+mkdir -p "${cache_dir}/pip"
+
+export CCACHE_DIR="${cache_dir}/ccache"
+export CCACHE_MAXSIZE="350M"
+
+# Clear ccache stats.
+ccache -z
+
+echo "::group::CMake configure"
 cmake -GNinja -Bbuild \
   -DCMAKE_BUILD_TYPE=Release \
   -DCMAKE_C_COMPILER_LAUNCHER=ccache \
@@ -14,9 +36,23 @@ cmake -GNinja -Bbuild \
   -DLLVM_EXTERNAL_PROJECTS="torch-mlir" \
   -DLLVM_EXTERNAL_TORCH_MLIR_SOURCE_DIR="$PWD" \
   -DPython3_EXECUTABLE="$(which python)" \
+  -DPython_EXECUTABLE="$(which python)" \
   -DTORCH_MLIR_ENABLE_STABLEHLO=OFF \
-  $GITHUB_WORKSPACE/externals/llvm-project/llvm
+  -DTORCH_MLIR_ENABLE_PYTORCH_EXTENSIONS=ON \
+  -DTORCH_MLIR_ENABLE_LTC=OFF \
+  -DTORCH_MLIR_ENABLE_JIT_IR_IMPORTER=ON \
+  $repo_root/externals/llvm-project/llvm
+echo "::endgroup::"
 
-cmake --build build --config Release
+echo "::group::Build"
+cmake --build $repo_root/build  --target tools/torch-mlir/all -- -k 0
+echo "::endgroup::"
 
 echo "Build completed successfully"
+
+echo "::group::Unit tests"
+cmake --build $repo_root/build --target check-torch-mlir
+echo "::endgroup::"
+
+# Show ccache stats.
+ccache --show-stats

test/python/fx_importer/sparsity/lit.local.cfg

@@ -2,7 +2,7 @@ config.unsupported = True
 
 try:
   import torch
-  if "2.5.0" <= str(torch.__version__):
+  if "2.5.0" <= str(torch.__version__) and "Windows" not in config.host_os:
     print("Enabling sparsity propagation tests")
     config.unsupported = False
 

test/python/fx_importer/v2.3/lit.local.cfg

@@ -2,7 +2,7 @@ config.unsupported = True
 
 try:
   import torch
-  if torch.__version__ >= "2.3.0":
+  if torch.__version__ >= "2.3.0" and "Windows" not in config.host_os:
     print("Enabling Torch v2.3+ tests")
     config.unsupported = False
 except ModuleNotFoundError:

test/python/lit.local.cfg

@@ -1,2 +1,2 @@
-if not config.enable_bindings_python:
+if not config.enable_bindings_python or "Windows" in config.host_os:
   config.unsupported = True