SharedLibrary.hpp

// SPDX-FileCopyrightText: 2026 Vincent Leroy
// SPDX-License-Identifier: MIT
//
// This file is part of dfx.
//
// Licensed under the MIT License. See the LICENSE file in the project root
// for full license information.
 
#pragma once
 
// Standard includes
#include <expected>
#include <memory>
 
// Project includes
#include <dfx-utilities/CompilerSupport.hpp>
#include <dfx-utilities/CopyMoveControl.hpp>
#include <dfx-utilities/EnumString.hpp>
#include <dfx-utilities/FileSystem.hpp>
#include <dfx-utilities/Flags.hpp>
 
namespace dfx::Plugins
{
class SharedLibrary
{
public:
    enum class LoadFlag
    {
        Lazy     = 0x01, 
        Now      = 0x02, 
        Global   = 0x04, 
        Local    = 0x08, 
        NoDelete = 0x10, 
    };
    DFX_DECLARE_FLAGS(LoadFlags, LoadFlag);

    static constexpr LoadFlags defaultLoadFlags = LoadFlags(LoadFlag::Now) | LoadFlag::Local;
 
public:
    explicit SharedLibrary(fs::path libPath, LoadFlags loadFlags = defaultLoadFlags);

    SharedLibrary(SharedLibrary && other) noexcept;

    ~SharedLibrary();
 
    DFX_DISABLE_COPY(SharedLibrary);

    SharedLibrary & operator=(SharedLibrary && other) noexcept;
 
public:
    fs::path const & libPath() const noexcept { return _libPath; }

    bool isLoaded() const noexcept { return _handle != nullptr; }
 
public:
    template<typename T>
    std::expected<T, std::string> resolveSymbol(std::string const & name) const noexcept
    {
        auto const result = _resolveSymbolImpl(name.c_str());
        if (!result.has_value())
            return std::unexpected(result.error());
 
        DFX_DIAGNOSTIC_PUSH
        DFX_DIAGNOSTIC_IGNORE("-Wconditionally-supported")
        return reinterpret_cast<T>(result.value());
        DFX_DIAGNOSTIC_POP
    }
 
private:
    void _close() noexcept;
    std::expected<void *, std::string> _resolveSymbolImpl(char const * name) const noexcept;
 
private:
    fs::path _libPath;
    void * _handle = nullptr;
};

using SharedLibraryPtr = std::unique_ptr<SharedLibrary>;
} // !namespace dfx::Plugins
 
DFX_DECLARE_ENUM_STRING_FUNCTIONS(::dfx::Plugins::SharedLibrary::LoadFlag);
DFX_DECLARE_OPERATOR_FOR_FLAGS(::dfx::Plugins::SharedLibrary::LoadFlags)
DFX_DECLARE_STD_FORMATTER_FOR_FLAGS(::dfx::Plugins::SharedLibrary::LoadFlags);