Create script for checking lint locally (iree-org#7733)

Add a simple local bash script for locally checking all the lint we
check on presubmit. This is far from perfect, but I think better than
nothing. Problems it has:

1. It edits the working directory and index
2. I have no idea how cross-platform it is
3. It assumes that script shebang lines will be enough to find the
   appropriate executable, which may frequently not be true (especially
   for python)

.github/workflows/lint.yml

@@ -4,6 +4,8 @@
 # See https://llvm.org/LICENSE.txt for license information.
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
+# Keep this in sync with scripts/lint.sh
+
 name: Lint
 
 on: [pull_request]

scripts/lint.sh

@@ -0,0 +1,122 @@
+#!/bin/bash
+
+# Copyright 2021 The IREE Authors
+#
+# Licensed under the Apache License v2.0 with LLVM Exceptions.
+# See https://llvm.org/LICENSE.txt for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+# Runs all the lint checks that we run on GitHub locally. Skips checks if the
+# relevant tool doesn't exist.
+
+# Keep this in sync with .github/workflows/lint.yml
+
+# WARNING: this script *makes changes* to the working directory and the index.
+
+set -uo pipefail
+
+FINAL_RET=0
+LATEST_RET=0
+
+function update_ret() {
+  LATEST_RET="$?"
+  if [[ "${LATEST_RET}" -gt "${FINAL_RET}" ]]; then
+    FINAL_RET="${LATEST_RET}"
+  fi
+}
+
+# Update the exit code after every command
+function enable_update_ret() {
+  trap update_ret DEBUG
+}
+
+function disable_update_ret() {
+  trap - DEBUG
+}
+
+function exists() {
+  command -v "${1}" > /dev/null
+}
+
+
+echo "***** Uncommitted changes *****"
+git add -A
+git diff HEAD --exit-code
+
+if [[ $? -ne 0 ]]; then
+  echo "Found uncomitted changes in working directory. This script requires" \
+        "all changes to be committed. All changes have been added to the" \
+        "index. Please commit or clean all changes and try again."
+  exit 1
+fi
+
+enable_update_ret
+
+echo "***** Bazel -> CMake *****"
+./build_tools/bazel_to_cmake/bazel_to_cmake.py
+./build_tools/bazel_to_cmake/bazel_to_cmake.py --root_dir=integrations/tensorflow/e2e
+git add -A
+git diff HEAD --exit-code
+trap - DEBUG
+
+echo "***** buildifier *****"
+# Don't fail script if condition is false
+disable_update_ret
+if exists buildifier; then
+  enable_update_ret
+  ./scripts/run_buildifier.sh
+  git diff --exit-code
+else
+  enable_update_ret
+  echo "'buildifier' not found. Skipping check"
+fi
+
+echo "***** yapf *****"
+# Don't fail script if condition is false
+disable_update_ret
+if exists yapf > /dev/null; then
+  enable_update_ret
+  git diff -U0 main | ./third_party/format_diff/format_diff.py yapf -i
+else
+  enable_update_ret
+  echo "'yapf' not found. Skipping check"
+fi
+
+echo "***** pytype *****"
+# Don't fail script if condition is false
+disable_update_ret
+if exists pytype; then
+  enable_update_ret
+  ./build_tools/pytype/check_diff.sh
+else
+  enable_update_ret
+  echo "'pytype' not found. Skipping check"
+fi
+
+echo "***** clang-format *****"
+# Don't fail script if condition is false
+disable_update_ret
+if exists git-clang-format; then
+  enable_update_ret
+  git-clang-format --style=file
+  git diff --exit-code
+else
+  enable_update_ret
+  echo "'git-clang-format' not found. Skipping check"
+fi
+
+echo "***** submodules *****"
+./scripts/git/submodule_versions.py check
+
+echo "***** tabs *****"
+./scripts/check_tabs.sh
+
+echo "***** yamllint *****"
+echo "'yamllint' check not yet implemented. Skipping check"
+
+if [[ "${FINAL_RET}" -ne 0 ]]; then
+  echo "Encountered failures. Check error messages and changes to the working" \
+       "directory and git index (which may contain fixes) and try again."
+fi
+
+exit "${FINAL_RET}"