From 52c18363a5ba82ef18d00b643e17e0cb40de29fb Mon Sep 17 00:00:00 2001
From: Flatcar Buildbot <buildbot@flatcar-linux.org>
Date: Mon, 14 Nov 2022 07:16:30 +0000
Subject: [PATCH] eclass/toolchain: Sync with Gentoo

It's from Gentoo commit 803ac64d367c4c865a2c30f1196dfec95dc7fee1.
---
 .../portage-stable/eclass/toolchain.eclass    | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 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 2bed15110e..4b96a08735 100644
--- a/sdk_container/src/third_party/portage-stable/eclass/toolchain.eclass
+++ b/sdk_container/src/third_party/portage-stable/eclass/toolchain.eclass
@@ -100,6 +100,12 @@ tc_version_is_between() {
 # @DESCRIPTION:
 # Indicate the developer who hosts the patchset for an ebuild.
 
+# @ECLASS_VARIABLE: TOOLCHAIN_SPHINX_BUILD
+# @DEFAULT_UNSET
+# @DESCRIPTION:
+# Indicate if Sphinx is needed for this build. Enabled by default for
+# >= 13.*.9999 (this is when upstream changed their docs from texinfo->sphinx).
+
 # @ECLASS_VARIABLE: GCC_PV
 # @INTERNAL
 # @DESCRIPTION:
@@ -289,7 +295,8 @@ fi
 
 #---->> DEPEND <<----
 
-RDEPEND="sys-libs/zlib
+RDEPEND="
+	sys-libs/zlib
 	virtual/libiconv
 	nls? ( virtual/libintl )
 "
@@ -320,10 +327,18 @@ BDEPEND="
 	test? (
 		>=dev-util/dejagnu-1.4.4
 		>=sys-devel/autogen-5.5.4
-	)"
+	)
+"
 DEPEND="${RDEPEND}"
 
+# Snapshots don't contain info or man pages.
 if [[ ${PN} == gcc && ${PV} == *_p* ]] ; then
+	# >= GCC 13 needs sphinx to generate the info and man pages.
+	# It still uses texinfo as well.
+	if [[ -n ${TOOLCHAIN_SPHINX_BUILD} ]] ; then
+		BDEPEND+=" dev-python/sphinx"
+	fi
+
 	# Snapshots don't contain info pages.
 	# If they start to, adjust gcc_cv_prog_makeinfo_modern logic in toolchain_src_configure.
 	# Needed unless/until https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106899 is fixed