[clang] [clang-cl] Parse (but don't support) /BE (PR #228381)

[Hans Wennborg via cfe-commits]

https://github.com/zmodem created https://github.com/llvm/llvm-project/pull/228381

It's an undocumented CL option mentioned at
https://old.reddit.com/r/cpp/comments/1wudtq0/edg_c_fronted_now_released_as_open_source/pd3m2au/

>From 61f8c444f8e0de899a76b54d7841d7a51f705c24 Mon Sep 17 00:00:00 2001
From: Hans Wennborg <hans at chromium.org>
Date: Fri, 2 Oct 2026 12:10:20 +0200
Subject: [PATCH] [clang-cl] Parse (but don't support) /BE

It's an undocumented CL option mentioned at
https://old.reddit.com/r/cpp/comments/1wudtq0/edg_c_fronted_now_released_as_open_source/pd3m2au/
---
 clang/include/clang/Options/Options.td | 1 +
 clang/test/Driver/cl-options.c         | 1 +
 2 files changed, 2 insertions(+)

diff --git a/clang/include/clang/Options/Options.td b/clang/include/clang/Options/Options.td
index 60ae84cb0af5c..5fb5b75e15a19 100644
--- a/clang/include/clang/Options/Options.td
+++ b/clang/include/clang/Options/Options.td
@@ -9855,6 +9855,7 @@ def _SLASH_await : CLFlag<"await">;
 def _SLASH_await_COLON : CLJoined<"await:">;
 def _SLASH_constexpr : CLJoined<"constexpr:">;
 def _SLASH_AI : CLJoinedOrSeparate<"AI">;
+def _SLASH_BE : CLFlag<"BE">;
 def _SLASH_Bt : CLFlag<"Bt">;
 def _SLASH_Bt_plus : CLFlag<"Bt+">;
 def _SLASH_clr : CLJoined<"clr">;
diff --git a/clang/test/Driver/cl-options.c b/clang/test/Driver/cl-options.c
index 57d82622ef4de..2b4d887b027a9 100644
--- a/clang/test/Driver/cl-options.c
+++ b/clang/test/Driver/cl-options.c
@@ -444,6 +444,7 @@
 // RUN:     /constexpr:depth1000 /constexpr:backtrace1000 /constexpr:steps1000 \
 // RUN:     /AIfoo \
 // RUN:     /AI foo_does_not_exist \
+// RUN:     /BE \
 // RUN:     /Bt \
 // RUN:     /Bt+ \
 // RUN:     /clr:pure \