From 44b4ba37c33d89067146da3c1046550680bbe64d Mon Sep 17 00:00:00 2001
From: Flatcar Buildbot <buildbot@flatcar-linux.org>
Date: Mon, 30 Oct 2023 07:13:17 +0000
Subject: [PATCH] eclass/toolchain: Sync with Gentoo

It's from Gentoo commit 52f4e8653f56ce713659dfe7880b5c272cc5a817.
---
 .../portage-stable/eclass/toolchain.eclass           | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/sdk_container/src/third_party/portage-stable/eclass/toolchain.eclass b/sdk_container/src/third_party/portage-stable/eclass/toolchain.eclass
index 8df8b506b0..bf5e512703 100644
--- a/sdk_container/src/third_party/portage-stable/eclass/toolchain.eclass
+++ b/sdk_container/src/third_party/portage-stable/eclass/toolchain.eclass
@@ -1535,6 +1535,18 @@ gcc_do_filter_flags() {
 		fi
 	fi
 
+
+	if ver_test -lt 13.6 ; then
+		# These aren't supported by the just-built compiler either.
+		filter-flags -fharden-compares -fharden-conditional-branches \
+			-fharden-control-flow-redundancy -fno-harden-control-flow-redundancy \
+			-fhardcfr-skip-leaf -fhardcfr-check-exceptions \
+			-fhardcfr-check-returning-calls '-fhardcfr-check-noreturn-calls=*'
+	else
+		# Makes things painfully slow and no real benefit for the compiler.
+		append-flags $(test-flags-CC -fno-harden-control-flow-redundancy)
+	fi
+
 	# Please use USE=lto instead (bug #906007).
 	filter-lto