From: Sergei Trofimovich <slyfox@gentoo.org>
Date: Fri, 19 Apr 2019 07:32:12 +0000 (+0000)
Subject: sys-libs/glibc: disable c++ detection for cross-case, bug #683074
X-Git-Url: http://git.tremily.us/gitweb.cgi?a=commitdiff_plain;h=15fbfc075d699e498d73701b6f2a3f62d7dcabba;p=gentoo.git

sys-libs/glibc: disable c++ detection for cross-case, bug #683074

https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=561b0bec4448f0302cb4915bf67c919bde4a1c57
in unstream glibc repo added optional dependency on CXX compiler.

Unfortunately ./configure tries hard to pass some g++ as CXX:
either ${CTARGET}-g++ (ok) or ${CBUILD}+g++ (bad).

During toolchain bootstrap ${CTARGET}-g++ does not yet exist
as we only have stage1-gcc without c++ (or libc) support.

To restore toolchain bootstrap we force-disable c++ detection
by setting cache variable:
    libc_cv_cxx_link_ok=no

c++ is force disables only for cross-compilation case
(CHOST != CTARGET). Cross-building case (CHOST = CTRAGET)
is unchanged as we should already have c++ capable toolchain
by then.

Reported-by: hanetzer@startmail.com
Reported-by: rhn
Closes: https://bugs.gentoo.org/683074
Package-Manager: Portage-2.3.63, Repoman-2.3.12
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
---

diff --git a/sys-libs/glibc/glibc-2.29-r2.ebuild b/sys-libs/glibc/glibc-2.29-r2.ebuild
index 093ffc207ebd..8f920eb85ac4 100644
--- a/sys-libs/glibc/glibc-2.29-r2.ebuild
+++ b/sys-libs/glibc/glibc-2.29-r2.ebuild
@@ -799,6 +799,17 @@ glibc_do_configure() {
 
 	# Some of the tests are written in C++, so we need to force our multlib abis in, bug 623548
 	export CXX="$(tc-getCXX ${CTARGET}) $(get_abi_CFLAGS) ${CFLAGS}"
+
+	if is_crosscompile; then
+		# Assume worst-case bootstrap: glibc is buil first time
+		# when ${CTARGET}-g++ is not available yet. We avoid
+		# building auxiliary programs that require C++: bug #683074
+		# It should not affect final result.
+		export libc_cv_cxx_link_ok=no
+		# The line above has the same effect. We set CXX explicitly
+		# to make build logs less confusing.
+		export CXX=
+	fi
 	einfo " $(printf '%15s' 'Manual CXX:')   ${CXX}"
 
 	echo
diff --git a/sys-libs/glibc/glibc-9999.ebuild b/sys-libs/glibc/glibc-9999.ebuild
index 142153734f97..b01dc8236359 100644
--- a/sys-libs/glibc/glibc-9999.ebuild
+++ b/sys-libs/glibc/glibc-9999.ebuild
@@ -800,6 +800,17 @@ glibc_do_configure() {
 
 	# Some of the tests are written in C++, so we need to force our multlib abis in, bug 623548
 	export CXX="$(tc-getCXX ${CTARGET}) $(get_abi_CFLAGS) ${CFLAGS}"
+
+	if is_crosscompile; then
+		# Assume worst-case bootstrap: glibc is buil first time
+		# when ${CTARGET}-g++ is not available yet. We avoid
+		# building auxiliary programs that require C++: bug #683074
+		# It should not affect final result.
+		export libc_cv_cxx_link_ok=no
+		# The line above has the same effect. We set CXX explicitly
+		# to make build logs less confusing.
+		export CXX=
+	fi
 	einfo " $(printf '%15s' 'Manual CXX:')   ${CXX}"
 
 	echo