plugin.h

/*******************************************************************************
 * Copyright (C) 2015-2019 Commissariat a l'energie atomique et aux energies alternatives (CEA)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
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 *   notice, this list of conditions and the following disclaimer.
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 *   documentation and/or other materials provided with the distribution.
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 *   endorse or promote products derived from this software without specific
 *   prior written permission.
 *
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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#ifndef PDI_PLUGIN_H_
#define PDI_PLUGIN_H_

#include <memory>
#include <string>
#include <type_traits>
#include <unordered_set>
#include <utility>

#include <pdi/pdi_fwd.h>
#include <pdi/logger.h>

namespace PDI {


class PDI_EXPORT Plugin
{
    Context& m_context;
    
public:
    Plugin(const Plugin&) = delete;
    
    Plugin(Plugin&&) = delete;
    
    Plugin(Context& ctx);
    
    virtual ~Plugin() noexcept(false);
    
    Context& context();
    
}; // class Plugin


#define PLUGIN_API_VERSION_MAJOR (0ul)

#define PLUGIN_API_VERSION_MINOR (0ul)

#define PLUGIN_API_VERSION_PATCH (1ul)

#define PLUGIN_API_VERSION ((PLUGIN_API_VERSION_MAJOR<<24) + (PLUGIN_API_VERSION_MINOR<<16) + (PLUGIN_API_VERSION_PATCH<<8))

unsigned long PDI_EXPORT plugin_api_version(unsigned long expected_version=0);

} // namespace PDI

namespace {

template <class T>
struct has_dependencies {
    template <typename C>
    static constexpr decltype(C::dependencies(), bool()) test(int)
    {
        return true;
    }
    template <typename C>
    static constexpr bool test(...)
    {
        return false;
    }
    static constexpr bool value = test<T>(int());
};

template <class T>
typename std::enable_if<has_dependencies<T>::value, std::pair<std::unordered_set<std::string>, std::unordered_set<std::string>>>::type plugin_dependencies()
{
    return T::dependencies();
}

template <class T>
typename std::enable_if<!has_dependencies<T>::value, std::pair<std::unordered_set<std::string>, std::unordered_set<std::string>>>::type plugin_dependencies()
{
    return {};
}

} // namespace <anonymous>

#define PDI_PLUGIN(name)\
    _Pragma("clang diagnostic push")\
    _Pragma("clang diagnostic ignored \"-Wmissing-prototypes\"")\
    _Pragma("clang diagnostic ignored \"-Wreturn-type-c-linkage\"")\
    extern "C" ::std::unique_ptr<::PDI::Plugin> PDI_EXPORT PDI_plugin_##name##_loader(::PDI::Context& ctx, PC_tree_t conf) \
    {\
        auto plugin = ::std::unique_ptr<name##_plugin>{new name##_plugin{ctx, conf}};\
        ::PDI::plugin_api_version(PLUGIN_API_VERSION);\
        return plugin;\
    }\
    extern "C" ::std::pair<::std::unordered_set<::std::string>, ::std::unordered_set<::std::string>> PDI_EXPORT PDI_plugin_##name##_dependencies() \
    {\
        return ::plugin_dependencies<name##_plugin>();\
    }\
    _Pragma("clang diagnostic pop")

#endif // PDI_PLUGIN_H_