Switch to pre-commit for lint checks. (#3200)

Users can run via `pre-commit run` or set up a hook as described in the
instructions: https://pre-commit.com/

The CI is set to only run pre-commit on files changed in the patch. We
will run with `--all-files` in a separate patch.

.github/workflows/lint.yml

@@ -1,26 +0,0 @@
-# yamllint disable rule:line-length
-name: Lint Checks
-
-on:
-  push:
-    branches: [main]
-  pull_request:
-    branches: [main]
-
-jobs:
-  static_lint_checks:
-    name: Static Lint Checks
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-        with:
-          # `git-clang-format` needs access to the commit before the
-          # current merge commit to know what changes to format.
-          fetch-depth: 2
-      - name: Validate GitHub Actions yaml files
-        run: |
-          yamllint ./.github/workflows/ ./.github/actions/
-      - name: Check clang-format
-        run: |
-          wget -q https://raw.githubusercontent.com/llvm/llvm-project/main/clang/tools/clang-format/git-clang-format
-          python3 git-clang-format --diff HEAD~1

.github/workflows/pre-commit.yml

@@ -0,0 +1,19 @@
+name: pre-commit
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+      with:
+        # requites to grab the history of the PR
+        fetch-depth: 0
+    - uses: actions/setup-python@v3
+    - uses: pre-commit/action@v3.0.1
+      with:
+        extra_args: --color=always --from-ref ${{ github.event.pull_request.base.sha }} --to-ref ${{ github.event.pull_request.head.sha }}

.pre-commit-config.yaml

@@ -0,0 +1,21 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+exclude: "GeneratedTorchOps\\.td|abstract_interp_lib_gen\\.py|\\.excalidraw"
+repos:
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v3.2.0
+    hooks:
+    -   id: trailing-whitespace
+    -   id: end-of-file-fixer
+    -   id: check-ast
+    -   id: check-yaml
+    -   id: check-added-large-files
+-   repo: https://github.com/psf/black
+    rev: 22.10.0
+    hooks:
+    -   id: black
+
+-   repo: https://github.com/pre-commit/mirrors-clang-format
+    rev: 'v18.1.4'
+    hooks:
+    -   id: clang-format

.style.yapf

@@ -1,2 +0,0 @@
-[style]
-  based_on_style = pep8

README.md

@@ -16,7 +16,7 @@ The MLIR project offers a novel approach for building extensible and reusable co
 [Torch-MLIR](https://github.com/llvm/torch-mlir)
 Several vendors have adopted MLIR as the middle layer in their systems, enabling them to map frameworks such as PyTorch, JAX, and TensorFlow into MLIR and subsequently lower them to their target hardware. We have observed half a dozen custom lowerings from PyTorch to MLIR, making it easier for hardware vendors to focus on their unique value, rather than needing to implement yet another PyTorch frontend for MLIR. The ultimate aim is to be similar to the current hardware vendors adding LLVM target support, rather than each one implementing Clang or a C++ frontend.
 
-[![Release Build](https://github.com/llvm/torch-mlir/actions/workflows/buildRelease.yml/badge.svg)](https://github.com/llvm/torch-mlir/actions/workflows/buildRelease.yml)
+[![pre-commit](https://img.shields.io/badge/pre--commit-enabled-brightgreen?logo=pre-commit)](https://github.com/pre-commit/pre-commit)
 
 ## All the roads from PyTorch to Torch MLIR Dialect
 

docs/development.md

@@ -26,6 +26,19 @@ python -m pip install -r requirements.txt
 python -m pip install -r torchvision-requirements.txt
 ```
 
+## (Optional) Set up pre-commit
+
+This project uses [pre-commit](https://pre-commit.com/) in its CI. You can
+install it locally too in order to lint and fix your code prior to the CI
+complaining about it.
+
+```shell
+pip install pre-commit
+# You can run interactively with `pre-commit run`
+# or install hooks so it runs automatically:
+pre-commit install
+```
+
 ## CMake Build
 
 Two setups are possible to build: in-tree and out-of-tree. The in-tree setup is the most straightforward, as it will build LLVM dependencies as well.

pyproject.toml

@@ -0,0 +1,7 @@
+[build-system]
+requires = ["setuptools", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[tool.black]
+line-length = 88
+target-version = ['py38']