vtk-m/vtkm/internal/ExportMacros.h
David C. Lonie 4807b3c472 Silence warnings about unavoidable weak vtables.
- Exception classes cannot be exported due to MSVC's design decisions.
  See http://stackoverflow.com/questions/24511376. We must leave these
  classes as header only and silence the warnings.
- TransferResource in BufferState.h must remain a header-only class since
  there is no vtkm_interop library to compile the class into.
- The VTKDataSetReader hierarchy must similarly remain header-only since
  there is no vtkm_io library.
- The OptionParser Action classes are part of a header-only utility and
  cannot be easily compiled into a library.
-
2017-04-13 14:06:33 -04:00

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C

//============================================================================
// Copyright (c) Kitware, Inc.
// All rights reserved.
// See LICENSE.txt for details.
// This software is distributed WITHOUT ANY WARRANTY; without even
// the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
// PURPOSE. See the above copyright notice for more information.
//
// Copyright 2014 Sandia Corporation.
// Copyright 2014 UT-Battelle, LLC.
// Copyright 2014 Los Alamos National Security.
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
//
// Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
// Laboratory (LANL), the U.S. Government retains certain rights in
// this software.
//============================================================================
#ifndef vtk_m_internal__ExportMacros_h
#define vtk_m_internal__ExportMacros_h
#include <vtkm/internal/Configure.h>
/*!
* Export macros for various parts of the VTKm library.
*/
#ifdef VTKM_CUDA
#define VTKM_EXEC __device__ __host__
#define VTKM_EXEC_CONT __device__ __host__
#if __CUDAVER__ >= 75000
# define VTKM_SUPPRESS_EXEC_WARNINGS #pragma nv_exec_check_disable
#else
# define VTKM_SUPPRESS_EXEC_WARNINGS #pragma hd_warning_disable
#endif
#define VTKM_EXEC_CONSTANT __device__ __constant__
#else
#define VTKM_EXEC
#define VTKM_EXEC_CONT
#define VTKM_SUPPRESS_EXEC_WARNINGS
#define VTKM_EXEC_CONSTANT
#endif
#define VTKM_CONT
// Background:
// VTK-m libraries are built with the hidden symbol visibility by default.
// This means that all template classes that are defined in VTK-m headers are
// defined with hidden visibility when we are building VTK-m. But when those
// headers are included by a third-party which has differing visibility controls
// causing link time warnings ( external vs private ).
//
// Issue:
// Dynamic cast is not just based on the name of the class, but also the
// combined visibility of the class on OSX. When building the hash_code of
// an object the symbol visibility controls of the type are taken into
// consideration ( including symbol vis of template parameters ).
// Therefore if a class has a component with private/hidden vis than it
// can't be passed across library boundaries.
//
// Example is PolymorphicArrayHandleContainer<T,S> whose visibility affected
// by the visibility of both T and S.
//
// Solution:
// The solution is fairly simple, but annoying. You need to mark
//
// TL;DR:
// This markup is used when we want to make sure:
// - The class can be compiled into multiple libraries and at runtime will
// resolve to a single type instance
// - Be a type ( or component of a types signature ) that can be passed between
// dynamic libraries and requires RTTI support ( dynamic_cast ).
#if defined(VTKM_MSVC)
# define VTKM_ALWAYS_EXPORT
# define VTKM_NEVER_EXPORT
#else
# define VTKM_ALWAYS_EXPORT __attribute__((visibility("default")))
# define VTKM_NEVER_EXPORT __attribute__((visibility("hidden")))
#endif
// constexpr support was added to VisualStudio 2015 and above. So this makes
// sure when that we gracefully fall back to just const when using 2013
#if defined(VTKM_MSVC) && _MSC_VER < 1900
#define VTKM_CONSTEXPR const
#define VTKM_NOEXCEPT
#else
#define VTKM_CONSTEXPR constexpr
#define VTKM_NOEXCEPT noexcept
#endif
#define VTKM_OVERRIDE override
// Clang will warn about weak vtables (-Wweak-vtables) on exception classes,
// but there's no good way to eliminate them in this case because MSVC (See
// http://stackoverflow.com/questions/24511376). These macros will silence the
// warning for classes defined within them.
#ifdef VTKM_CLANG
#define VTKM_SILENCE_WEAK_VTABLE_WARNING_START \
_Pragma("clang diagnostic push") \
_Pragma("clang diagnostic ignored \"-Wweak-vtables\"")
#define VTKM_SILENCE_WEAK_VTABLE_WARNING_END \
_Pragma("clang diagnostic pop")
#else // VTKM_CLANG
#define VTKM_SILENCE_WEAK_VTABLE_WARNING_START
#define VTKM_SILENCE_WEAK_VTABLE_WARNING_END
#endif // VTKM_CLANG
/// Simple macro to identify a parameter as unused. This allows you to name a
/// parameter that is not used. There are several instances where you might
/// want to do this. For example, when using a parameter to overload or
/// template a function but do not actually use the parameter. Another example
/// is providing a specialization that does not need that parameter.
#define vtkmNotUsed(parameter_name)
#endif //vtk_m_internal__ExportMacros_h