From: Michael Froman <mfroman@mozilla.com>
Date: Wed, 8 Oct 2025 17:49:00 +0000
Subject: Bug 1980501 - enable c++20 builds in libwebrtc. r?ng!

Differential Revision: https://phabricator.services.mozilla.com/D267994
Mercurial Revision: https://hg.mozilla.org/mozilla-central/rev/43de54a6e52daf0a06956ae01951ef1e29d46e82
---
 BUILD.gn | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/BUILD.gn b/BUILD.gn
index 8240fc84d6..a3b738a7e1 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -315,6 +315,16 @@ config("common_config") {
   cflags_objc = []
   defines = []
 
+  # We should be able to remove this after c++20 is enabled
+  # across the Mozilla tree.
+  if (build_with_mozilla) {
+    if (is_win) {
+      cflags_cc += [ "-std:c++20" ]
+    } else {
+      cflags_cc += [ "-std=gnu++20" ]
+    }
+  }
+
   if (rtc_enable_protobuf) {
     defines += [ "WEBRTC_ENABLE_PROTOBUF=1" ]
   } else {
@@ -420,7 +430,7 @@ config("common_config") {
         # "-Wnested-externs",  (C/Obj-C only)
       ]
       cflags_objc += [ "-Wstrict-prototypes" ]
-      cflags_cc = [
+      cflags_cc += [
         "-Wnon-virtual-dtor",
 
         # This is enabled for clang; enable for gcc as well.