[clang] [clang] Improve CI output when trailing whitespace is found (PR #66649)

[Louis Dionne via cfe-commits]

https://github.com/ldionne created https://github.com/llvm/llvm-project/pull/66649

Fixes #66468

>From df20b6321bf9332571fc4e45ae370793876f7773 Mon Sep 17 00:00:00 2001
From: Louis Dionne <ldionne.2 at gmail.com>
Date: Mon, 18 Sep 2023 09:58:29 -0400
Subject: [PATCH] [clang] Improve CI output when trailing whitespace is found

Fixes #66468
---
 clang/utils/ci/run-buildbot | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/clang/utils/ci/run-buildbot b/clang/utils/ci/run-buildbot
index d117fccc7e3fbd8..f47ffb5cbd38dcd 100755
--- a/clang/utils/ci/run-buildbot
+++ b/clang/utils/ci/run-buildbot
@@ -70,7 +70,11 @@ ninja --version
 
 case "${BUILDER}" in
 check-format)
-    ! grep -rnI '[[:blank:]]$' clang/lib clang/include clang/docs
+    echo "*** Checking for trailing whitespace left in Clang source files ***"
+    if grep -rnI '[[:blank:]]$' clang/lib clang/include clang/docs; then
+        echo "*** Trailing whitespace has been found in Clang source files as described above ***"
+        exit 1
+    fi
 ;;
 build-clang)
     mkdir install