From b03e99ab40e9f5189266e3fbe7312039ec193137 Mon Sep 17 00:00:00 2001
From: Arvid Norberg <arvid@libtorrent.org>
Date: Sun, 15 Apr 2012 04:00:58 +0000
Subject: [PATCH] fix DLL export issue on windows

---
 ChangeLog                     | 1 +
 Jamfile                       | 7 +++++++
 include/libtorrent/config.hpp | 2 +-
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index ef7e15b1b..f1cd33cc2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,5 @@
 
+	* fixed DLL export issue on windows (when building a shared library linking statically against boost)
 	* fixed FreeBSD build
 	* fixed web seed performance issue whith pieces > 1 MiB
 	* fixed unchoke logic when using web seeds
diff --git a/Jamfile b/Jamfile
index abdd682da..054cd730c 100755
--- a/Jamfile
+++ b/Jamfile
@@ -587,6 +587,13 @@ lib torrent
 	<define>BOOST_THREAD_USE_LIB
 	<threading>multi
 	<link>shared:<define>TORRENT_BUILDING_SHARED
+
+	# on windows, when linking statically against asio
+	# but producing a DLL, everything inside the DLL needs
+	# to declare the symbol as being exported
+	<link>shared,<boost-link>static:<define>BOOST_ASIO_SOURCE
+	<link>shared,<boost-link>static:<define>BOOST_SYSTEM_SOURCE
+
 	<dht-support>on:<source>src/kademlia/$(KADEMLIA_SOURCES).cpp
 	<dht-support>logging:<source>src/kademlia/$(KADEMLIA_SOURCES).cpp
 	<conditional>@building
diff --git a/include/libtorrent/config.hpp b/include/libtorrent/config.hpp
index c75e2ff3c..f9de4457e 100644
--- a/include/libtorrent/config.hpp
+++ b/include/libtorrent/config.hpp
@@ -69,7 +69,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 // backwards compatibility with older versions of boost
 #if !defined BOOST_SYMBOL_EXPORT && !defined BOOST_SYMBOL_IMPORT
-# ifdef _MSC_VER
+# if defined _MSC_VER || defined __MINGW32__
 #  define BOOST_SYMBOL_EXPORT __declspec(dllexport)
 #  define BOOST_SYMBOL_IMPORT __declspec(dllimport)
 # elif __GNU__ >= 4