From 0332e98cb8f5310bd29bb63991d025301a232eb2 Mon Sep 17 00:00:00 2001
From: Nico Weber <thakis@chromium.org>
Date: Fri, 30 Oct 2020 13:48:44 -0400
Subject: [PATCH] [gn build] port e58660750e76

Made necessary by c479e0c99459e4, which requires std::timespec
to exist, which it only does in c++17 and later.
---
 llvm/utils/gn/secondary/libcxx/src/BUILD.gn | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/llvm/utils/gn/secondary/libcxx/src/BUILD.gn b/llvm/utils/gn/secondary/libcxx/src/BUILD.gn
index 71668b6..150ab64 100644
--- a/llvm/utils/gn/secondary/libcxx/src/BUILD.gn
+++ b/llvm/utils/gn/secondary/libcxx/src/BUILD.gn
@@ -53,7 +53,10 @@ config("cxx_config") {
     "-Wno-user-defined-literals",
     "-Wno-covered-switch-default",
   ]
-  cflags_cc = [ "-nostdinc++" ]
+  cflags_cc = [
+    "-std=c++17",
+    "-nostdinc++",
+  ]
   defines = [ "_LIBCPP_BUILDING_LIBRARY" ]
   if (target_os == "win") {
     cflags += [ "/Zl" ]
-- 
2.7.4