1 files changed, 154 insertions, 0 deletions

diff --git a/dns/powerdns-recursor/files/patch-mtasker__fcontext.cc b/dns/powerdns-recursor/files/patch-mtasker__fcontext.cc
new file mode 100644
index 000000000000..41dd007e1309
--- /dev/null
+++ b/dns/powerdns-recursor/files/patch-mtasker__fcontext.cc
@@ -0,0 +1,154 @@
+rec: Add support for boost::context >= 1.61
+
+https://github.com/PowerDNS/pdns/commits/64413f6afd9b/pdns/mtasker_fcontext.cc
+
+--- mtasker_fcontext.cc.orig	2016-09-06 12:50:29 UTC
++++ mtasker_fcontext.cc
+@@ -23,14 +23,15 @@
+ #include <exception>
+ #include <cassert>
+ #include <type_traits>
+-#if BOOST_VERSION > 106100
+-#include <boost/context/detail/fcontext.hpp>
+-#else
+-#include <boost/context/fcontext.hpp>
+-#endif
+ #include <boost/version.hpp>
+-
++#if BOOST_VERSION < 106100
++#include <boost/context/fcontext.hpp>
+ using boost::context::make_fcontext;
++#else
++#include <boost/context/detail/fcontext.hpp>
++using boost::context::detail::make_fcontext;
++#endif /* BOOST_VERSION < 106100 */
++
+ 
+ #if BOOST_VERSION < 105600
+ /* Note: This typedef means functions taking fcontext_t*, like jump_fcontext(),
+@@ -61,8 +62,15 @@ jump_fcontext (fcontext_t* const ofc, fc
+     }
+ }
+ #else
++
++#if BOOST_VERSION < 106100
+ using boost::context::fcontext_t;
+ using boost::context::jump_fcontext;
++#else
++using boost::context::detail::fcontext_t;
++using boost::context::detail::jump_fcontext;
++using boost::context::detail::transfer_t;
++#endif /* BOOST_VERSION < 106100 */
+ 
+ static_assert (std::is_pointer<fcontext_t>::value,
+                "Boost Context has changed the fcontext_t type again :-(");
+@@ -72,7 +80,9 @@ static_assert (std::is_pointer<fcontext_
+  * jump. args_t simply provides a way to pass more by reference.
+  */
+ struct args_t {
++#if BOOST_VERSION < 106100
+     fcontext_t prev_ctx = nullptr;
++#endif
+     pdns_ucontext_t* self = nullptr;
+     boost::function<void(void)>* work = nullptr;
+ };
+@@ -80,7 +90,11 @@ struct args_t {
+ extern "C" {
+ static
+ void
++#if BOOST_VERSION < 106100
+ threadWrapper (intptr_t const xargs) {
++#else
++threadWrapper (transfer_t const t) {
++#endif
+     /* Access the args passed from pdns_makecontext, and copy them directly from
+      * the calling stack on to ours (we're now using the MThreads stack).
+      * This saves heap allocating an args object, at the cost of an extra
+@@ -90,11 +104,28 @@ threadWrapper (intptr_t const xargs) {
+      * the behaviour of the System V implementation, which can inherently only
+      * be passed ints and pointers.
+      */
++#if BOOST_VERSION < 106100
+     auto args = reinterpret_cast<args_t*>(xargs);
++#else
++    auto args = reinterpret_cast<args_t*>(t.data);
++#endif
+     auto ctx = args->self;
+     auto work = args->work;
++    /* we switch back to pdns_makecontext() */
++#if BOOST_VERSION < 106100
+     jump_fcontext (reinterpret_cast<fcontext_t*>(&ctx->uc_mcontext),
+                    static_cast<fcontext_t>(args->prev_ctx), 0);
++#else
++    transfer_t res = jump_fcontext (t.fctx, 0);
++    /* we got switched back from pdns_swapcontext() */
++    if (res.data) {
++      /* if res.data is not a nullptr, it holds a pointer to the context
++         we just switched from, and we need to fill it to be able to
++         switch back to it later. */
++      fcontext_t* ptr = static_cast<fcontext_t*>(res.data);
++      *ptr = res.fctx;
++    }
++#endif
+     args = nullptr;
+ 
+     try {
+@@ -106,9 +137,14 @@ threadWrapper (intptr_t const xargs) {
+ 
+     /* Emulate the System V uc_link feature. */
+     auto const next_ctx = ctx->uc_link->uc_mcontext;
++#if BOOST_VERSION < 106100
+     jump_fcontext (reinterpret_cast<fcontext_t*>(&ctx->uc_mcontext),
+                    static_cast<fcontext_t>(next_ctx),
+                    static_cast<bool>(ctx->exception));
++#else
++    jump_fcontext (static_cast<fcontext_t>(next_ctx), 0);
++#endif
++
+ #ifdef NDEBUG
+     __builtin_unreachable();
+ #endif
+@@ -129,10 +165,27 @@ pdns_ucontext_t::~pdns_ucontext_t
+ void
+ pdns_swapcontext
+ (pdns_ucontext_t& __restrict octx, pdns_ucontext_t const& __restrict ctx) {
++  /* we either switch back to threadwrapper() if it's the first time,
++     or we switch back to pdns_swapcontext(),
++     in both case we will be returning from a call to jump_fcontext(). */
++#if BOOST_VERSION < 106100
+     if (jump_fcontext (reinterpret_cast<fcontext_t*>(&octx.uc_mcontext),
+                        static_cast<fcontext_t>(ctx.uc_mcontext), 0)) {
+         std::rethrow_exception (ctx.exception);
+     }
++#else
++  transfer_t res = jump_fcontext (static_cast<fcontext_t>(ctx.uc_mcontext), &octx.uc_mcontext);
++  if (res.data) {
++    /* if res.data is not a nullptr, it holds a pointer to the context
++       we just switched from, and we need to fill it to be able to
++       switch back to it later. */
++    fcontext_t* ptr = static_cast<fcontext_t*>(res.data);
++    *ptr = res.fctx;
++  }
++  if (ctx.exception) {
++    std::rethrow_exception (ctx.exception);
++  }
++#endif
+ }
+ 
+ void
+@@ -146,7 +199,15 @@ pdns_makecontext
+     args_t args;
+     args.self = &ctx;
+     args.work = &start;
++    /* jumping to threadwrapper */
++#if BOOST_VERSION < 106100
+     jump_fcontext (reinterpret_cast<fcontext_t*>(&args.prev_ctx),
+                    static_cast<fcontext_t>(ctx.uc_mcontext),
+                    reinterpret_cast<intptr_t>(&args));
++#else
++    transfer_t res = jump_fcontext (static_cast<fcontext_t>(ctx.uc_mcontext),
++                                    &args);
++    /* back from threadwrapper, updating the context */
++    ctx.uc_mcontext = res.fctx;
++#endif
+ }