regression: `upcxx::copy(T*,global_ptr<T>,size_t)` fails to compile

[Dan Bonachea]

The upcxx::copy(T*,global_ptr<T>,size_t) overload is broken and does not compile as of 2020.3.0.

Test program:

#include <upcxx/upcxx.hpp>
#include <iostream>
#include <assert.h>

using namespace upcxx;

int main() {
  upcxx::init();

  global_ptr<int> gp = new_<int>();
  if (!rank_me()) *gp.local() = 42;
  auto gp0 = broadcast(gp,0).wait();
  global_ptr<int> gp2 = new_<int>(0);
  int *lp = gp2.local();
  copy(gp0, lp, 1).wait();
  assert(*lp == 42);
  copy(gp0, gp, 1).wait();
  assert(*gp.local() == 42);
  barrier();
  *gp.local() = 0;
  copy(lp, gp, 1).wait();
  assert(*gp.local() == 42);

  barrier();
  delete_(gp);
  delete_(gp2);
  if (!rank_me()) std::cout << "SUCCESS" << std::endl;
  upcxx::finalize();
  return 0;
}

Compile error:

In file included from /redacted/bld/upcxx.assert1.optlev0.dbgsym1.gasnet_seq.smp/include/upcxx/upcxx.hpp:10,
                 from copy-bug.cpp:1:
/redacted/bld/upcxx.assert1.optlev0.dbgsym1.gasnet_seq.smp/include/upcxx/copy.hpp: In instantiation of 'typename upcxx::detail::completions_returner<upcxx::detail::event_is_here, upcxx::detail::rput_event_values, Cxs>::return_t upcxx::copy(const T*, upcxx::global_ptr<T, KindSet>, std::size_t, Cxs) [with T = int; upcxx::memory_kind Kd = upcxx::memory_kind::host; Cxs = upcxx::completions<upcxx::future_cx<upcxx::operation_cx_event, upcxx::progress_level::user> >; typename upcxx::detail::completions_returner<upcxx::detail::event_is_here, upcxx::detail::rput_event_values, Cxs>::return_t = upcxx::future1<upcxx::detail::future_kind_shref<upcxx::detail::future_header_ops_general> >; std::size_t = long unsigned int]':
copy-bug.cpp:21:17:   required from here
/redacted/bld/upcxx.assert1.optlev0.dbgsym1.gasnet_seq.smp/include/upcxx/copy.hpp:66:65: error: invalid 'const_cast' from type 'const int*' to type 'void*'
   66 |     return detail::copy( detail::host_device, upcxx::rank_me(), const_cast<void*>(src),

This regression was introduced in ede7acbb prior to release 2020.3.0 and persists in develop. Until now we've had no tests invoking this overload, which is why it went undetected.

[Dan Bonachea]

Proposed fix in pull request #266.

Here is the minimal patch to fix the problem:

--- a/src/copy.hpp
+++ b/src/copy.hpp
@@ -63,7 +63,7 @@ namespace upcxx {
     UPCXX_ASSERT_INIT();
     UPCXX_GPTR_CHK(dest);
     UPCXX_ASSERT(src && dest, "pointer arguments to copy may not be null");
-    return detail::copy( detail::host_device, upcxx::rank_me(), const_cast<void*>(src),
+    return detail::copy( detail::host_device, upcxx::rank_me(), const_cast<T*>(src),
                          dest.device_, dest.rank_, dest.raw_ptr_,
                          n * sizeof(T), std::move(cxs) );
   }

[Dan Bonachea]

fix issue #405: regression: upcxx::copy(T*,global_ptr<T>,size_t) fails to compile

Broken since 2020.3.0

→ <<cset d141d5dfaf1b>>

[Dan Bonachea]

Merge pull request #266 into develop

• issue405: Update ChangeLog add issue405 fix issue #405: regression: upcxx::copy(T*,global_ptr<T>,size_t) fails to compile

→ <<cset 32fe4863b7e3>>