From 08fca4df1db9b1ec09c846a8b415bd652cc48050 Mon Sep 17 00:00:00 2001
From: Jonathan Yong <10walls@gmail.com>
Date: Tue, 3 Nov 2020 07:47:12 +0000
Subject: [PATCH] libstdc++: use lt_host_flags for libstdc++.la

For platforms like Mingw and Cygwin, cygwin refuses to generate the
shared library without using -no-undefined.

Attached patch makes sure the right flags are used, since libtool is
already used to link libstdc++.

libstdc++-v3/ChangeLog:

	* src/Makefile.am (libstdc___la_LINK): Add lt_host_flags.
	* src/Makefile.in: Regenerate.
---
 libstdc++-v3/src/Makefile.am | 2 +-
 libstdc++-v3/src/Makefile.in | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/src/Makefile.am b/libstdc++-v3/src/Makefile.am
index 9a6807ae8c6b..1eda70edb379 100644
--- a/libstdc++-v3/src/Makefile.am
+++ b/libstdc++-v3/src/Makefile.am
@@ -110,7 +110,7 @@ libstdc___la_DEPENDENCIES = \
 libstdc___la_LDFLAGS = \
 	-version-info $(libtool_VERSION) ${version_arg} -lm
 
-libstdc___la_LINK = $(CXXLINK) $(libstdc___la_LDFLAGS)
+libstdc___la_LINK = $(CXXLINK) $(libstdc___la_LDFLAGS) $(lt_host_flags)
 
 # Use special rules for compatibility-ldbl.cc compilation, as we need to
 # pass -mlong-double-64.
diff --git a/libstdc++-v3/src/Makefile.in b/libstdc++-v3/src/Makefile.in
index e51e61640558..7f5591713550 100644
--- a/libstdc++-v3/src/Makefile.in
+++ b/libstdc++-v3/src/Makefile.in
@@ -519,7 +519,7 @@ libstdc___la_DEPENDENCIES = \
 libstdc___la_LDFLAGS = \
 	-version-info $(libtool_VERSION) ${version_arg} -lm
 
-libstdc___la_LINK = $(CXXLINK) $(libstdc___la_LDFLAGS)
+libstdc___la_LINK = $(CXXLINK) $(libstdc___la_LDFLAGS) $(lt_host_flags)
 
 # A note on compatibility and static libraries.
 #
-- 
2.47.2