From c47de9e8be551705a4d3e4e06289914fb8ed4f75 Mon Sep 17 00:00:00 2001
From: gaaclarke <30870216+gaaclarke@users.noreply.github.com>
Date: Mon, 7 Nov 2022 14:40:53 -0800
Subject: [PATCH] clang-tidy: Added an environment variable that allows fix to
 print the (flutter/engine#37024)

generated diff.
---
 engine/src/flutter/ci/lint.sh | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/engine/src/flutter/ci/lint.sh b/engine/src/flutter/ci/lint.sh
index 00e31b8525..e5096b3518 100755
--- a/engine/src/flutter/ci/lint.sh
+++ b/engine/src/flutter/ci/lint.sh
@@ -36,6 +36,15 @@ DART="${DART_BIN}/dart"
 # to have this as an error.
 MAC_HOST_WARNINGS_AS_ERRORS="performance-move-const-arg,performance-unnecessary-value-param"
 
+# FLUTTER_LINT_PRINT_FIX will make it so that fix is executed and the generated
+# diff is printed to stdout if clang-tidy fails. This is helpful for enabling
+# new lints.
+if [[ -z "${FLUTTER_LINT_PRINT_FIX}" ]]; then
+  fix_flag=""
+else
+  fix_flag="--fix"
+fi
+
 COMPILE_COMMANDS="$SRC_DIR/out/host_debug/compile_commands.json"
 if [ ! -f "$COMPILE_COMMANDS" ]; then
   (cd "$SRC_DIR"; ./flutter/tools/gn)
@@ -49,7 +58,18 @@ cd "$SCRIPT_DIR"
   "$SRC_DIR/flutter/tools/clang_tidy/bin/main.dart" \
   --src-dir="$SRC_DIR" \
   --mac-host-warnings-as-errors="$MAC_HOST_WARNINGS_AS_ERRORS" \
-  "$@"
+  $fix_flag \
+  "$@" && true # errors ignored
+clang_tidy_return=$?
+if [ $clang_tidy_return -ne 0 ]; then
+  if [ -n "$fix_flag" ]; then
+    echo "###################################################"
+    echo "# Attempted to fix issues with the following patch:"
+    echo "###################################################"
+    git --no-pager diff
+  fi
+  exit $clang_tidy_return
+fi
 
 echo "$(date +%T) Running pylint"