[llvm-branch-commits] [clang-tools-extra] release/20.x: [clang-tidy] Do not pass any file when listing checks in run_clang_ti… (#137286) (PR #137775)

[Carlos Galvez via llvm-branch-commits]

https://github.com/carlosgalvezp updated https://github.com/llvm/llvm-project/pull/137775

>From 387c2886b68b1eaf888868916e4b08e8d92966a1 Mon Sep 17 00:00:00 2001
From: Carlos Galvez <carlosgalvezp at gmail.com>
Date: Tue, 29 Apr 2025 11:13:30 +0200
Subject: [PATCH] =?UTF-8?q?[clang-tidy]=20Do=20not=20pass=20any=20file=20w?=
 =?UTF-8?q?hen=20listing=20checks=20in=20run=5Fclang=5Fti=E2=80=A6=20(#137?=
 =?UTF-8?q?286)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

…dy.py

Currently, run_clang_tidy.py does not correctly display the list of
checks picked up from the top-level .clang-tidy file. The reason for
that is that we are passing an empty string as input file.

However, that's not how we are supposed to use clang-tidy to list
checks. Per
https://github.com/llvm/llvm-project/commit/65eccb463df7fe511c813ee6a1794c80d7489ff2,
we simply should not pass any file at all - the internal code of
clang-tidy will pass a "dummy" file if that's the case and get the
.clang-tidy file from the current working directory.

Fixes #136659

Co-authored-by: Carlos Gálvez <carlos.galvez at zenseact.com>
(cherry picked from commit 014ab736dc741f24c007f9861e24b31faba0e1e7)
---
 clang-tools-extra/clang-tidy/tool/run-clang-tidy.py | 7 ++++---
 clang-tools-extra/docs/ReleaseNotes.rst             | 3 +++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py b/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
index f1b934f7139e9..8741147a4f8a3 100755
--- a/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
+++ b/clang-tools-extra/clang-tidy/tool/run-clang-tidy.py
@@ -87,7 +87,7 @@ def find_compilation_database(path: str) -> str:
 
 
 def get_tidy_invocation(
-    f: str,
+    f: Optional[str],
     clang_tidy_binary: str,
     checks: str,
     tmpdir: Optional[str],
@@ -147,7 +147,8 @@ def get_tidy_invocation(
         start.append(f"--warnings-as-errors={warnings_as_errors}")
     if allow_no_checks:
         start.append("--allow-no-checks")
-    start.append(f)
+    if f:
+        start.append(f)
     return start
 
 
@@ -490,7 +491,7 @@ async def main() -> None:
 
     try:
         invocation = get_tidy_invocation(
-            "",
+            None,
             clang_tidy_binary,
             args.checks,
             None,
diff --git a/clang-tools-extra/docs/ReleaseNotes.rst b/clang-tools-extra/docs/ReleaseNotes.rst
index 2ab597eb37048..0b2e9c5fabc36 100644
--- a/clang-tools-extra/docs/ReleaseNotes.rst
+++ b/clang-tools-extra/docs/ReleaseNotes.rst
@@ -190,6 +190,9 @@ Improvements to clang-tidy
 - Fixed bug in :program:`clang-tidy` by which `HeaderFilterRegex` did not take
   effect when passed via the `.clang-tidy` file.
 
+- Fixed bug in :program:`run_clang_tidy.py` where the program would not
+  correctly display the checks enabled by the top-level `.clang-tidy` file.
+
 New checks
 ^^^^^^^^^^