[llvm] [Code Coverage] Add a tool to check test coverage of a patch (PR #71841)

[Shivam Gupta via llvm-commits]

================
@@ -0,0 +1,722 @@
+#!/usr/bin/env python3
+#
+# ===- git-check-coverage - CheckCoverage Git Integration ---------*- python -*--===#
+#
+# Part of the LLVM Project, 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
+#
+# ===------------------------------------------------------------------------===#
+
+r"""
+code-coverage git integration
+============================
+This file provides a code-coverage integration for git. Put it in your
+llvm-project root directory and ensure that it is executable. Code
+coverage information will be provided for the last commit/HEAD by
+runing below command.
+Example uses -
+          git check-coverage -b build bin/opt llvm/test
+Here b is build directory (optional, default is build)
+next we have binray
+and then test suite path
+"""
+
+import argparse
+import logging
+import os
+import subprocess
+import re
+import sys
+from unidiff import PatchSet
----------------
xgupta wrote:

If we are using requirements.txt then we need to create a folder. Can we comment in the script header for users to install dependency with `pip install unidiff`? WDYT? 

I do not remember, I have tried this without using unidiff, and then I discussed it with Henrik, and he suggested using the library, I think for clean formatting and easy use. We can re-evaluate that in next revisions.

https://github.com/llvm/llvm-project/pull/71841