From abd765baf576d28b5ac9d451cda56684180617ba Mon Sep 17 00:00:00 2001
From: Flatcar Buildbot <buildbot@flatcar-linux.org>
Date: Mon, 24 Apr 2023 07:14:32 +0000
Subject: [PATCH] eclass/toolchain: Sync with Gentoo

It's from Gentoo commit 70f21b8bd7fd130067ab5d4798371ae0ef7c6ea6.
---
 .../portage-stable/eclass/toolchain.eclass    | 31 +++++++++++++++----
 1 file changed, 25 insertions(+), 6 deletions(-)

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 6a04366bcc..ba83cad72c 100644
--- a/sdk_container/src/third_party/portage-stable/eclass/toolchain.eclass
+++ b/sdk_container/src/third_party/portage-stable/eclass/toolchain.eclass
@@ -280,7 +280,8 @@ if [[ ${PN} != kgcc64 && ${PN} != gcc-* ]] ; then
 	tc_version_is_at_least 12 && IUSE+=" ieee-long-double"
 	tc_version_is_at_least 12.2.1_p20221203 ${PV} && IUSE+=" default-znow"
 	tc_version_is_at_least 12.2.1_p20221203 ${PV} && IUSE+=" default-stack-clash-protection"
-	tc_version_is_at_least 13.0.0_pre20221211 ${PV} && IUSE+=" rust"
+	tc_version_is_at_least 13.0.0_pre20221218 ${PV} && IUSE+=" modula2"
+	tc_version_is_at_least 14.0.0_pre20230423 ${PV} && IUSE+=" rust"
 fi
 
 if tc_version_is_at_least 10; then
@@ -1045,6 +1046,7 @@ toolchain_src_configure() {
 	is_f77 && GCC_LANG+=",f77"
 	is_f95 && GCC_LANG+=",f95"
 	is_ada && GCC_LANG+=",ada"
+	is_modula2 && GCC_LANG+=",m2"
 	is_rust && GCC_LANG+=",rust"
 
 	confgcc+=( --enable-languages=${GCC_LANG} )
@@ -1066,12 +1068,24 @@ toolchain_src_configure() {
 
 	confgcc+=( --disable-libunwind-exceptions )
 
-	# Use the default ("release") checking because upstream usually neglects
-	# to test "disabled" so it has a history of breaking. bug #317217
 	if in_iuse debug ; then
-		# The "release" keyword is new to 4.0. bug #551636
-		local off=$(tc_version_is_at_least 4.0 && echo release || echo no)
-		confgcc+=( --enable-checking="${GCC_CHECKS_LIST:-$(usex debug yes ${off})}" )
+		# Non-released versions get extra checks, follow configure.ac's default to for those
+		# unless USE=debug. Note that snapshots on stable branches don't count as "non-released"
+		# for these purposes.
+		if grep -q "experimental" gcc/DEV-PHASE ; then
+			# - USE=debug for pre-releases: yes,extra,rtl
+			# - USE=-debug for pre-releases: yes,extra (following upstream default)
+			confgcc+=( --enable-checking="${GCC_CHECKS_LIST:-$(usex debug yes,extra,rtl yes,extra)}" )
+		else
+			# - Use the default ("release") checking because upstream usually neglects
+			#   to test "disabled" so it has a history of breaking. bug #317217.
+			# - The "release" keyword is new to 4.0. bug #551636.
+			# - After discussing in #gcc, we concluded that =yes,extra,rtl makes
+			#   more sense when a user explicitly requests USE=debug. If rtl is too slow,
+			#   we can change this to yes,extra.
+			local off=$(tc_version_is_at_least 4.0 && echo release || echo no)
+			confgcc+=( --enable-checking="${GCC_CHECKS_LIST:-$(usex debug yes,extra,rtl ${off})}" )
+		fi
 	fi
 
 	# Branding
@@ -2732,6 +2746,11 @@ is_objcxx() {
 	_tc_use_if_iuse cxx && _tc_use_if_iuse objc++
 }
 
+is_modula2() {
+	gcc-lang-supported m2 || return 1
+	_tc_use_if_iuse cxx && _tc_use_if_iuse modula2
+}
+
 is_rust() {
 	gcc-lang-supported rust || return 1
 	_tc_use_if_iuse rust