From 553d8e3b9073ff3e0a9d2fac9b1823fb17ad247c Mon Sep 17 00:00:00 2001
From: Khem Raj <raj.khem@gmail.com>
Date: Tue, 2 Feb 2016 21:00:18 -0800
Subject: [PATCH 49/51] Disable the weak reference logic in gthr.h for
 os/generic

It does not work unless work arounds are there in gthr-posix.h

origin of patch
http://port70.net/~nsz/musl/gcc-5.3.0/0004-gthr.patch

Signed-off-by: Khem Raj <raj.khem@gmail.com>
---
Upstream-Status: Pending

 libgfortran/acinclude.m4                    | 2 +-
 libgfortran/configure                       | 2 +-
 libstdc++-v3/config/os/generic/os_defines.h | 5 +++++
 libstdc++-v3/configure.host                 | 3 +++
 4 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/libgfortran/acinclude.m4 b/libgfortran/acinclude.m4
index ba890f9..30b8b1a6 100644
--- a/libgfortran/acinclude.m4
+++ b/libgfortran/acinclude.m4
@@ -100,7 +100,7 @@ void foo (void);
 	      [Define to 1 if the target supports #pragma weak])
   fi
   case "$host" in
-    *-*-darwin* | *-*-hpux* | *-*-cygwin* | *-*-mingw* )
+    *-*-darwin* | *-*-hpux* | *-*-cygwin* | *-*-mingw* | *-*-musl* )
       AC_DEFINE(GTHREAD_USE_WEAK, 0,
 		[Define to 0 if the target shouldn't use #pragma weak])
       ;;
diff --git a/libgfortran/configure b/libgfortran/configure
index 5d47e65..cdf9695 100755
--- a/libgfortran/configure
+++ b/libgfortran/configure
@@ -26456,7 +26456,7 @@ $as_echo "#define SUPPORTS_WEAK 1" >>confdefs.h
 
   fi
   case "$host" in
-    *-*-darwin* | *-*-hpux* | *-*-cygwin* | *-*-mingw* )
+    *-*-darwin* | *-*-hpux* | *-*-cygwin* | *-*-mingw* | *-*-musl* )
 
 $as_echo "#define GTHREAD_USE_WEAK 0" >>confdefs.h
 
diff --git a/libstdc++-v3/config/os/generic/os_defines.h b/libstdc++-v3/config/os/generic/os_defines.h
index 45bf52a..103ec0e 100644
--- a/libstdc++-v3/config/os/generic/os_defines.h
+++ b/libstdc++-v3/config/os/generic/os_defines.h
@@ -33,4 +33,9 @@
 // System-specific #define, typedefs, corrections, etc, go here.  This
 // file will come before all others.
 
+// Disable the weak reference logic in gthr.h for os/generic because it
+// is broken on every platform unless there is implementation specific
+// workaround in gthr-posix.h and at link-time for static linking.
+#define _GLIBCXX_GTHREAD_USE_WEAK 0
+
 #endif
diff --git a/libstdc++-v3/configure.host b/libstdc++-v3/configure.host
index 1756444..2a87bb8 100644
--- a/libstdc++-v3/configure.host
+++ b/libstdc++-v3/configure.host
@@ -273,6 +273,9 @@ case "${host_os}" in
   freebsd*)
     os_include_dir="os/bsd/freebsd"
     ;;
+  linux-musl*)
+    os_include_dir="os/generic"
+    ;;
   gnu* | linux* | kfreebsd*-gnu | knetbsd*-gnu)
     # check for musl by target
     case "${host_os}" in
-- 
2.7.0