remove dependency on aligned_storage and aligned_union to support older versions of GCC

include/libtorrent/Makefile.am

@@ -158,6 +158,8 @@ nobase_include_HEADERS = \
   span.hpp                     \
   \
   aux_/allocating_handler.hpp       \
+  aux_/aligned_storage.hpp          \
+  aux_/aligned_union.hpp            \
   aux_/bind_to_device.hpp           \
   aux_/block_cache_reference.hpp    \
   aux_/cpuid.hpp                    \

include/libtorrent/aux_/aligned_storage.hpp

@@ -0,0 +1,61 @@
+/*
+
+Copyright (c) 2017, Arvid Norberg
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#ifndef TORRENT_ALIGNED_STORAGE_HPP_INCLUDE
+#define TORRENT_ALIGNED_STORAGE_HPP_INCLUDE
+
+#include <type_traits>
+
+namespace libtorrent { namespace aux {
+
+#if defined __GNUC__ && __GNUC__ < 5
+
+// this is for backwards compatibility with not-quite C++11 compilers
+template <size_t Len, size_t Align = alignof(void*)>
+struct aligned_storage
+{
+	struct type
+	{
+		alignas(Align) char buffer[Len];
+	};
+};
+
+#else
+
+using std::aligned_storage;
+
+#endif
+
+}}
+
+#endif
+

include/libtorrent/aux_/aligned_union.hpp

@@ -0,0 +1,72 @@
+/*
+
+Copyright (c) 2017, Arvid Norberg
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#ifndef TORRENT_ALIGNED_UNION_HPP_INCLUDE
+#define TORRENT_ALIGNED_UNION_HPP_INCLUDE
+
+#include <type_traits>
+
+namespace libtorrent { namespace aux {
+
+#if defined __GNUC__ && __GNUC__ < 5
+
+constexpr std::size_t max(size_t a)
+{ return a; }
+
+constexpr std::size_t max(size_t a, size_t b)
+{ return a > b ? a : b; }
+
+template <typename... Vals>
+constexpr std::size_t max(size_t a, size_t b, Vals... v)
+{ return max(a, max(b, v...)); }
+
+// this is for backwards compatibility with not-quite C++11 compilers
+template <size_t Len, typename... Types>
+struct aligned_union
+{
+	struct type
+	{
+		alignas(max(alignof(Types)...))
+			char buffer[max(Len, max(sizeof(Types)...))];
+	};
+};
+
+#else
+
+using std::aligned_union;
+
+#endif
+
+}}
+
+#endif
+

include/libtorrent/aux_/allocating_handler.hpp

@@ -35,6 +35,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include "libtorrent/config.hpp"
 #include "libtorrent/error_code.hpp"
+#include "libtorrent/aux_/aligned_storage.hpp"
 
 #include <type_traits>
 
@@ -54,10 +55,8 @@ namespace libtorrent { namespace aux
 		{}
 
 		bool used;
-#else
-		handler_storage() {}
 #endif
-		typename std::aligned_storage<Size>::type bytes;
+		typename aux::aligned_storage<Size>::type bytes;
 	private:
 		handler_storage(handler_storage const&);
 	};

include/libtorrent/chained_buffer.hpp

@@ -35,6 +35,7 @@ POSSIBILITY OF SUCH DAMAGE.
 
 #include "libtorrent/config.hpp"
 #include "libtorrent/aux_/block_cache_reference.hpp"
+#include "libtorrent/aux_/aligned_storage.hpp"
 #include "libtorrent/debug.hpp"
 #include "libtorrent/buffer.hpp"
 
@@ -111,7 +112,7 @@ namespace libtorrent
 #if TORRENT_CPP98_DEQUE
 			move_construct_holder_fun move_holder;
 #endif
-			std::aligned_storage<24>::type holder;
+			aux::aligned_storage<24>::type holder;
 			char* buf; // the first byte of the buffer
 			int size; // the total size of the buffer
 			int used_size; // this is the number of bytes to send/receive

include/libtorrent/entry.hpp

@@ -73,6 +73,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/error_code.hpp"
 #include "libtorrent/span.hpp"
 #include "libtorrent/string_view.hpp"
+#include "libtorrent/aux_/aligned_union.hpp"
 
 namespace libtorrent
 {
@@ -311,7 +312,7 @@ namespace libtorrent
 
 		void to_string_impl(std::string& out, int indent) const;
 
-		std::aligned_union<1
+		aux::aligned_union<1
 #if TORRENT_COMPLETE_TYPES_REQUIRED
 			// for implementations that require complete types, use char and hope
 			// for the best

include/libtorrent/socket_type.hpp

@@ -33,9 +33,8 @@ POSSIBILITY OF SUCH DAMAGE.
 #ifndef TORRENT_SOCKET_TYPE
 #define TORRENT_SOCKET_TYPE
 
-#include <type_traits> // for aligned_union
-
 #include "libtorrent/config.hpp"
+#include "libtorrent/aux_/aligned_union.hpp"
 #include "libtorrent/socket.hpp"
 #include "libtorrent/socks5_stream.hpp"
 #include "libtorrent/http_stream.hpp"
@@ -300,7 +299,7 @@ namespace libtorrent
 		io_service& m_io_service;
 		int m_type;
 
-		std::aligned_union<1
+		aux::aligned_union<1
 			, tcp::socket
 			, socks5_stream
 			, http_stream

src/cpuid.cpp

@@ -46,7 +46,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <cstring> // for std::memset
 #endif
 
-#if TORRENT_HAS_ARM
+#if TORRENT_HAS_ARM && TORRENT_HAS_ARM_NEON
 #include <sys/auxv.h>
 #endif
 

src/kademlia/rpc_manager.cpp

@@ -48,6 +48,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include <libtorrent/hasher.hpp>
 #include <libtorrent/session_settings.hpp> // for dht_settings
 #include <libtorrent/aux_/time.hpp> // for aux::time_now
+#include <libtorrent/aux_/aligned_union.hpp>
 
 #include <type_traits>
 #include <functional>
@@ -135,7 +136,7 @@ void observer::set_id(node_id const& id)
 	if (m_algorithm) m_algorithm->resort_results();
 }
 
-using observer_storage = std::aligned_union<1
+using observer_storage = aux::aligned_union<1
 	, find_data_observer
 	, announce_observer
 	, put_data_observer