omni/extras/ForceLink.h

File members: omni/extras/ForceLink.h

// Copyright (c) 2021-2023, NVIDIA CORPORATION. All rights reserved.
//
// NVIDIA CORPORATION and its licensors retain all intellectual property
// and proprietary rights in and to this software, related documentation
// and any modifications thereto. Any use, reproduction, disclosure or
// distribution of this software and related documentation without an express
// license agreement from NVIDIA CORPORATION is strictly prohibited.
//
#pragma once

#include "../core/Platform.h"

#if OMNI_PLATFORM_WINDOWS
// see below for why we unfortunately either need this or to forward declare SetLastError()
// directly here instead of using something like strerror_s() on Windows.
#    include "../../carb/CarbWindows.h"
#endif

namespace omni
{
namespace extras
{

class ForceSymbolLink
{
public:
    ForceSymbolLink(void* ptr)
    {
#if OMNI_PLATFORM_WINDOWS
        // On Windows, we unfortunately can't call into something like strerror_s() to
        // accomplish this task because the CRT is statically linked to the module that
        // will be using this.  That would make the function we're passing the symbol
        // to local and therefore the symbol will still be discardable.  Instead, we'll
        // pass the address to SetLastError() which will always be available from 'kernel32'.
        SetLastError(static_cast<DWORD>(reinterpret_cast<uintptr_t>(ptr)));
#else
        char* str;
        CARB_UNUSED(str);
        str = strerror(static_cast<int>(reinterpret_cast<uintptr_t>(ptr)));
#endif
    }
};

} // namespace extras
} // namespace omni

#define OMNI_FORCE_SYMBOL_LINK(symbol_, tag_)                                                                          \
    static omni::extras::ForceSymbolLink CARB_JOIN(                                                                    \
        g_forceLink##tag_##_, CARB_JOIN(CARB_JOIN(__COUNTER__, _), __LINE__))(&(symbol_))