[llvm] [GitHub][CI] Add clang-tidy premerge workflow (PR #154829)

[Aiden Grossman via llvm-commits]

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@@ -0,0 +1,345 @@
+#!/usr/bin/env python3
+#
+# ====- clang-tidy-helper, runs clang-tidy from the ci --*- 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
+#
+# ==-------------------------------------------------------------------------==#
+
+import argparse
+import os
+import subprocess
+import sys
+from typing import List, Optional
+
+"""
+This script is run by GitHub actions to ensure that the code in PR's conform to
+the coding style of LLVM. The canonical source of this script is in the LLVM
+source tree under llvm/utils/git.
+
+You can learn more about the LLVM coding style on llvm.org:
+https://llvm.org/docs/CodingStandards.html
+"""
+
+
+class LintArgs:
+    start_rev: str = None
+    end_rev: str = None
+    repo: str = None
+    changed_files: List[str] = []
+    token: str = None
+    verbose: bool = True
+    issue_number: int = 0
+    build_path: str = "build"
+    clang_tidy_binary: str = "clang-tidy"
+
+    def __init__(self, args: argparse.Namespace = None) -> None:
+        if not args is None:
+            self.start_rev = args.start_rev
+            self.end_rev = args.end_rev
+            self.repo = args.repo
+            self.token = args.token
+            self.changed_files = args.changed_files
+            self.issue_number = args.issue_number
+            self.verbose = args.verbose
+            self.build_path = args.build_path
+            self.clang_tidy_binary = args.clang_tidy_binary
+
+
+COMMENT_TAG = "<!--LLVM CODE LINT COMMENT: clang-tidy-->"
+
+
+def get_instructions(cpp_files: List[str]) -> str:
+    files_str = " ".join(cpp_files)
+    return f"""
+git diff -U0 origin/main..HEAD -- {files_str} |
+python3 clang-tools-extra/clang-tidy/tool/clang-tidy-diff.py \\
+  -path build -p1 -quiet"""
+
+
+def clean_clang_tidy_output(output: str) -> Optional[str]:
+    """
+    - Remove 'Running clang-tidy in X threads...' line
+    - Remove 'N warnings generated.' line
+    - Strip leading workspace path from file paths
+    """
+    if not output or output == "No relevant changes found.":
+        return None
+
+    lines = output.split("\n")
+    cleaned_lines = []
+
+    for line in lines:
+        if line.startswith("Running clang-tidy in") or line.endswith("generated."):
+            continue
+
+        # Remove everything up to rightmost "llvm-project/" for correct files names
+        idx = line.rfind("llvm-project/")
+        if idx != -1:
+            line = line[idx + len("llvm-project/") :]
+
+        cleaned_lines.append(line)
+
+    if cleaned_lines:
+        return "\n".join(cleaned_lines)
+    return None
+
+
+def should_lint_file(filepath: str) -> bool:
----------------
boomanaiden154 wrote:

Maybe a TODO that this needs to be extended in the future?

https://github.com/llvm/llvm-project/pull/154829