signal.h and swig on MinGW

[Chaffra Affouda]

On MinGW,

The swig wrapping fails with the following. It looks like swig does not know what sigaction is. It builds fine on Linux but something is missing to build on MinGW. I think I have to include signal.h somewhere for swig to get it but I don't know where.

FEniCS/src/dolfin/dorsal_build_dir/dolfin/swig/modules/common/modulePYTHON
_wrap.cxx:4674:24: error: aggregate 'dolfin::dolfin_terminate()::sigaction act' has incomplete type
and cannot be defined
       struct sigaction act;
                        ^
FEniCS/src/dolfin/dorsal_build_dir/dolfin/swig/modules/common/modulePYTHON
_wrap.cxx:4677:36: error: invalid use of incomplete type 'struct dolfin::dolfin_terminate()::sigaction'
       sigaction(SIGABRT, &act, NULL);
                                    ^
FEniCS/src/dolfin/dorsal_build_dir/dolfin/swig/modules/common/modulePYTHON
_wrap.cxx:4674:14: note: forward declaration of 'struct dolfin::dolfin_terminate()::sigaction'
       struct sigaction act;

[Jan Blechta]

According to this SO thread, configuring with

cmake -DCMAKE_CXX_FLAGS:STRING="-D_XOPEN_SOURCE" <other_args> <src_dir>

could help. Can you try it?

[Chaffra Affouda]

Thanks Jan,

I tried that but that did not help. Looks like sigaction does not exist on MinGW. It's not present in my signal.h file. Does this hack seem sensible to you:

#include <signal.h>

  namespace dolfin {
    void dolfin_terminate() noexcept
    {
      #ifdef __MINGW32__
      raise(SIGABRT);
      #else
      // Uninstall signal handlers of OpenMPI cluttering stderr
      struct sigaction act;
      memset(&act, 0, sizeof(act));
      act.sa_handler = SIG_IGN;
      sigaction(SIGABRT, &act, NULL);
      #endif

      // We don't bother with MPI_Abort. This would require taking care of
      // MPI state. We just assume mpirun catches SIGABRT and sends SIGTERM
      // to other ranks.
      std::abort();
    }

[Jan Blechta]

What about being consistent and use std::abort() while just omitting uninstallation of OpenMPI signal handler

#include <signal.h>

  namespace dolfin {
    void dolfin_terminate() noexcept
    {
      // Uninstall signal handlers of OpenMPI cluttering stderr (does not work on MinGW)
      #ifndef __MINGW32__
      struct sigaction act;
      memset(&act, 0, sizeof(act));
      act.sa_handler = SIG_IGN;
      sigaction(SIGABRT, &act, NULL);
      #endif

      // We don't bother with MPI_Abort. This would require taking care of
      // MPI state. We just assume mpirun catches SIGABRT and sends SIGTERM
      // to other ranks.
      std::abort();
    }

[Chaffra Affouda]

Sure that works. Thanks.

[Jan Blechta]

Fixed by 7cdb3c4.

[Anders Logg (Chalmers)]

Removing milestone: 1.7 (automated comment)