build: enable -Wunsafe-buffer-usage warnings (#44056)

build/args/all.gn

@@ -77,3 +77,6 @@ enterprise_cloud_content_analysis = false
 # TODO: remove dependency on legacy ipc
 # https://issues.chromium.org/issues/40943039
 content_enable_legacy_ipc = true
+
+# Electron has its own unsafe-buffers enforcement directories.
+clang_unsafe_buffers_paths = "//electron/electron_unsafe_buffers_paths.txt"

electron_unsafe_buffers_paths.txt

@@ -0,0 +1,34 @@
+# Copyright 2024 The Electron Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# The set of path prefixes that should be checked for unsafe buffer usage (see
+# -Wunsafe-buffer-usage in Clang).
+#
+# ***
+# Paths should be written as relative to the root of the source tree with
+# unix-style path separators. Directory prefixes should end with `/`, such
+# as `base/`.
+# ***
+#
+# Files in this set are known to not use pointer arithmetic/subscripting, and
+# make use of constructs like base::span or containers like std::vector instead.
+#
+# See `docs/unsafe_buffers.md`.
+
+# These directories are excluded because they come from outside Electron and
+# we don't have control over their contents.
+-base/
+-chrome/
+-components/
+-device/
+-extensions/
+-google_apis/
+-net/
+-services/
+-skia/
+-third_party/
+-tools/
+-ui/
+-url/
+-v8/