// Copyright 2016 Klemens Morgenstern
//
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt
// or copy at http://www.boost.org/LICENSE_1_0.txt)
#ifndef BOOST_DLL_SMART_LIBRARY_HPP_
#define BOOST_DLL_SMART_LIBRARY_HPP_
/// \file boost/dll/smart_library.hpp
/// \warning Extremely experimental! Requires C++14! Will change in next version of Boost! boost/dll/smart_library.hpp is not included in boost/dll.hpp
/// \brief Contains the boost::dll::experimental::smart_library class for loading mangled symbols.
#if BOOST_COMP_GNUC || BOOST_COMP_CLANG || BOOST_COMP_HPACC || BOOST_COMP_IBM
#include <boost/dll/detail/demangling/itanium.hpp>
#elif BOOST_COMP_MSVC
#include <boost/dll/detail/demangling/msvc.hpp>
#else
#error "Compiler not supported"
#endif
#include <boost/dll/shared_library.hpp>
#include <boost/dll/detail/get_mem_fn_type.hpp>
#include <boost/dll/detail/ctor_dtor.hpp>
#include <boost/dll/detail/type_info.hpp>
#include <boost/type_traits/is_object.hpp>
#include <boost/type_traits/is_void.hpp>
#include <boost/type_traits/is_function.hpp>
#include <boost/predef/compiler.h>
namespace boost {
namespace dll {
namespace experimental {
using boost::dll::detail::constructor;
using boost::dll::detail::destructor;
/*!
* \brief This class is an extension of \ref shared_library, which allows to load C++ symbols.
*
* This class allows type safe loading of overloaded functions, member-functions, constructors and variables.
* It also allows to overwrite classes so they can be loaded, while being declared with different names.
*
* \warning Is still very experimental.
*
* Currently known limitations:
*
* Member functions must be defined outside of the class to be exported. That is:
* \code
* //not exported:
* struct BOOST_SYMBOL_EXPORT my_class { void func() {}};
* //exported
* struct BOOST_SYMBOL_EXPORT my_class { void func();};
* void my_class::func() {};
* \endcode
*
* With the current analysis, the first version does get exported in MSVC.
* MinGW also does export it, BOOST_SYMBOL_EXPORT is written before it. To allow this on windows one can use
* BOOST_DLL_MEMBER_EXPORT for this, so that MinGW and MSVC can provide those functions. This does however not work with gcc on linux.
*
* Direct initialization of members.
* On linux the following member variable i will not be initialized when using the allocating contructor:
* \code
* struct BOOST_SYMBOL_EXPORT my_class { int i; my_class() : i(42) {} };
* \endcode
*
* This does however not happen when the value is set inside the constructor function.
*/
class smart_library {
shared_library _lib;
detail::mangled_storage_impl _storage;
public:
/*!
* Get the underlying shared_library
*/
const shared_library &shared_lib() const {return _lib;}
using mangled_storage = detail::mangled_storage_impl;
/*!
* Acces to the mangled storage, which is created on construction.
*
* \throw Nothing.
*/
const mangled_storage &symbol_storage() const {return _storage;}
///Overload, for current development.
mangled_storage &symbol_storage() {return _storage;}
//! \copydoc shared_library::shared_library()
smart_library() BOOST_NOEXCEPT {};
//! \copydoc shared_library::shared_library(const boost::filesystem::path& lib_path, load_mode::type mode = load_mode::default_mode)
smart_library(const boost::filesystem::path& lib_path, load_mode::type mode = load_mode::default_mode) {
_lib.load(lib_path, mode);
_storage.load(lib_path);
}
//! \copydoc shared_library::shared_library(const boost::filesystem::path& lib_path, boost::system::error_code& ec, load_mode::type mode = load_mode::default_mode)
smart_library(const boost::filesystem::path& lib_path, boost::system::error_code& ec, load_mode::type mode = load_mode::default_mode) {
load(lib_path, mode, ec);
}
//! \copydoc shared_library::shared_library(const boost::filesystem::path& lib_path, load_mode::type mode, boost::system::error_code& ec)
smart_library(const boost::filesystem::path& lib_path, load_mode::type mode, boost::system::error_code& ec) {
load(lib_path, mode, ec);
}
/*!
* copy a smart_library object.
*
* \param lib A smart_library to move from.
*
* \throw Nothing.
*/
smart_library(const smart_library & lib) BOOST_NOEXCEPT
: _lib(lib._lib), _storage(lib._storage)
{}
/*!
* Move a smart_library object.
*
* \param lib A smart_library to move from.
*
* \throw Nothing.
*/
smart_library(BOOST_RV_REF(smart_library) lib) BOOST_NOEXCEPT
: _lib(boost::move(lib._lib)), _storage(boost::move(lib._storage))
{}
/*!
* Construct from a shared_library object.
*
* \param lib A shared_library to move from.
*
* \throw Nothing.
*/
explicit smart_library(const shared_library & lib) BOOST_NOEXCEPT
: _lib(lib)
{
_storage.load(lib.location());
}
/*!
* Construct from a shared_library object.
*
* \param lib A shared_library to move from.
*
* \throw Nothing.
*/
explicit smart_library(BOOST_RV_REF(shared_library) lib) BOOST_NOEXCEPT
: _lib(boost::move(static_cast<shared_library&>(lib)))
{
_storage.load(lib.location());
}
/*!
* Destroys the smart_library.
* `unload()` is called if the DLL/DSO was loaded. If library was loaded multiple times
* by different instances of shared_library, the actual DLL/DSO won't be unloaded until
* there is at least one instance of shared_library.
*
* \throw Nothing.
*/
~smart_library() BOOST_NOEXCEPT {};
//! \copydoc shared_library::load(const boost::filesystem::path& lib_path, load_mode::type mode = load_mode::default_mode)
void load(const boost::filesystem::path& lib_path, load_mode::type mode = load_mode::default_mode) {
boost::system::error_code ec;
_storage.load(lib_path);
_lib.load(lib_path, mode, ec);
if (ec) {
boost::dll::detail::report_error(ec, "load() failed");
}
}
//! \copydoc shared_library::load(const boost::filesystem::path& lib_path, boost::system::error_code& ec, load_mode::type mode = load_mode::default_mode)
void load(const boost::filesystem::path& lib_path, boost::system::error_code& ec, load_mode::type mode = load_mode::default_mode) {
ec.clear();
_storage.load(lib_path);
_lib.load(lib_path, mode, ec);
}
//! \copydoc shared_library::load(const boost::filesystem::path& lib_path, load_mode::type mode, boost::system::error_code& ec)
void load(const boost::filesystem::path& lib_path, load_mode::type mode, boost::system::error_code& ec) {
ec.clear();
_storage.load(lib_path);
_lib.load(lib_path, mode, ec);
}
/*!
* Load a variable from the referenced library.
*
* Unlinke shared_library::get this function will also load scoped variables, which also includes static class members.
*
* \note When mangled, MSVC will also check the type.
*
* \param name Name of the variable
* \tparam T Type of the variable
* \return A reference to the variable of type T.
*
* \throw boost::system::system_error if symbol does not exist or if the DLL/DSO was not loaded.
*/
template<typename T>
T& get_variable(const std::string &name) const {
return _lib.get<T>(_storage.get_variable<T>(name));
}
/*!
* Load a function from the referenced library.
*
* \b Example:
*
* \code
* smart_library lib("test_lib.so");
* typedef int (&add_ints)(int, int);
* typedef double (&add_doubles)(double, double);
* add_ints f1 = lib.get_function<int(int, int)> ("func_name");
* add_doubles f2 = lib.get_function<double(double, double)>("func_name");
* \endcode
*
* \note When mangled, MSVC will also check the return type.
*
* \param name Name of the function.
* \tparam Func Type of the function, required for determining the overload
* \return A reference to the function of type F.
*
* \throw boost::system::system_error if symbol does not exist or if the DLL/DSO was not loaded.
*/
template<typename Func>
Func& get_function(const std::string &name) const {
return _lib.get<Func>(_storage.get_function<Func>(name));
}
/*!
* Load a member-function from the referenced library.
*
* \b Example (import class is MyClass, which is available inside the library and the host):
*
* \code
* smart_library lib("test_lib.so");
*
* typedef int MyClass(*func)(int);
* typedef int MyClass(*func_const)(int) const;
*
* add_ints f1 = lib.get_mem_fn<MyClass, int(int)> ("MyClass::function");
* add_doubles f2 = lib.get_mem_fn<const MyClass, double(double)>("MyClass::function");
* \endcode
*
* \note When mangled, MSVC will also check the return type.
*
* \param name Name of the function.
* \tparam Class The class the function is a member of. If Class is const, the function will be assumed as taking a const this-pointer. The same applies for volatile.
* \tparam Func Signature of the function, required for determining the overload
* \return A pointer to the member-function with the signature provided
*
* \throw boost::system::system_error if symbol does not exist or if the DLL/DSO was not loaded.
*/
template<typename Class, typename Func>
typename boost::dll::detail::get_mem_fn_type<Class, Func>::mem_fn get_mem_fn(const std::string& name) const {
return _lib.get<typename boost::dll::detail::get_mem_fn_type<Class, Func>::mem_fn>(
_storage.get_mem_fn<Class, Func>(name)
);
}
/*!
* Load a constructor from the referenced library.
*
* \b Example (import class is MyClass, which is available inside the library and the host):
*
* \code
* smart_library lib("test_lib.so");
*
* constructor<MyClass(int) f1 = lib.get_mem_fn<MyClass(int)>();
* \endcode
*
* \tparam Signature Signature of the function, required for determining the overload. The return type is the class which this is the constructor of.
* \return A constructor object.
*
* \throw boost::system::system_error if symbol does not exist or if the DLL/DSO was not loaded.
*/
template<typename Signature>
constructor<Signature> get_constructor() const {
return boost::dll::detail::load_ctor<Signature>(_lib, _storage.get_constructor<Signature>());
}
/*!
* Load a destructor from the referenced library.
*
* \b Example (import class is MyClass, which is available inside the library and the host):
*
* \code
* smart_library lib("test_lib.so");
*
* destructor<MyClass> f1 = lib.get_mem_fn<MyClass>();
* \endcode
*
* \tparam Class The class whichs destructor shall be loaded
* \return A destructor object.
*
* \throw boost::system::system_error if symbol does not exist or if the DLL/DSO was not loaded.
*
*/
template<typename Class>
destructor<Class> get_destructor() const {
return boost::dll::detail::load_dtor<Class>(_lib, _storage.get_destructor<Class>());
}
/*!
* Load the typeinfo of the given type.
*
* \b Example (import class is MyClass, which is available inside the library and the host):
*
* \code
* smart_library lib("test_lib.so");
*
* std::type_info &ti = lib.get_Type_info<MyClass>();
* \endcode
*
* \tparam Class The class whichs typeinfo shall be loaded
* \return A reference to a type_info object.
*
* \throw boost::system::system_error if symbol does not exist or if the DLL/DSO was not loaded.
*
*/
template<typename Class>
const std::type_info& get_type_info() const
{
return boost::dll::detail::load_type_info<Class>(_lib, _storage);
}
/**
* This function can be used to add a type alias.
*
* This is to be used, when a class shall be imported, which is not declared on the host side.
*
* Example:
* \code
* smart_library lib("test_lib.so");
*
* lib.add_type_alias<MyAlias>("MyClass"); //when using MyAlias, the library will look for MyClass
*
* //get the destructor of MyClass
* destructor<MyAlias> dtor = lib.get_destructor<MyAlias>();
* \endcode
*
*
* \param name Name of the class the alias is for.
*
* \attention If the alias-type is not large enough for the imported class, it will result in undefined behaviour.
* \warning The alias will only be applied for the type signature, it will not replace the token in the scoped name.
*/
template<typename Alias> void add_type_alias(const std::string& name) {
this->_storage.add_alias<Alias>(name);
}
//! \copydoc shared_library::unload()
void unload() BOOST_NOEXCEPT {
_storage.clear();
_lib.unload();
}
//! \copydoc shared_library::is_loaded() const
bool is_loaded() const BOOST_NOEXCEPT {
return _lib.is_loaded();
}
//! \copydoc shared_library::operator!() const
bool operator!() const BOOST_NOEXCEPT {
return !is_loaded();
}
//! \copydoc shared_library::operator bool() const
BOOST_EXPLICIT_OPERATOR_BOOL()
//! \copydoc shared_library::has(const char* symbol_name) const
bool has(const char* symbol_name) const BOOST_NOEXCEPT {
return _lib.has(symbol_name);
}
//! \copydoc shared_library::has(const std::string& symbol_name) const
bool has(const std::string& symbol_name) const BOOST_NOEXCEPT {
return _lib.has(symbol_name);
}
//! \copydoc shared_library::assign(const shared_library& lib)
smart_library& assign(const smart_library& lib) {
_lib.assign(lib._lib);
_storage.assign(lib._storage);
return *this;
}
//! \copydoc shared_library::swap(shared_library& rhs)
void swap(smart_library& rhs) BOOST_NOEXCEPT {
_lib.swap(rhs._lib);
_storage.swap(rhs._storage);
}
};
/// Very fast equality check that compares the actual DLL/DSO objects. Throws nothing.
inline bool operator==(const smart_library& lhs, const smart_library& rhs) BOOST_NOEXCEPT {
return lhs.shared_lib().native() == rhs.shared_lib().native();
}
/// Very fast inequality check that compares the actual DLL/DSO objects. Throws nothing.
inline bool operator!=(const smart_library& lhs, const smart_library& rhs) BOOST_NOEXCEPT {
return lhs.shared_lib().native() != rhs.shared_lib().native();
}
/// Compare the actual DLL/DSO objects without any guarantee to be stable between runs. Throws nothing.
inline bool operator<(const smart_library& lhs, const smart_library& rhs) BOOST_NOEXCEPT {
return lhs.shared_lib().native() < rhs.shared_lib().native();
}
/// Swaps two shared libraries. Does not invalidate symbols and functions loaded from libraries. Throws nothing.
inline void swap(smart_library& lhs, smart_library& rhs) BOOST_NOEXCEPT {
lhs.swap(rhs);
}
#ifdef BOOST_DLL_DOXYGEN
/** Helper functions for overloads.
*
* Gets either a variable, function or member-function, depending on the signature.
*
* @code
* smart_library sm("lib.so");
* get<int>(sm, "space::value"); //import a variable
* get<void(int)>(sm, "space::func"); //import a function
* get<some_class, void(int)>(sm, "space::class_::mem_fn"); //import a member function
* @endcode
*
* @param sm A reference to the @ref smart_library
* @param name The name of the entity to import
*/
template<class T, class T2>
void get(const smart_library& sm, const std::string &name);
#endif
template<class T>
T& get(const smart_library& sm, const std::string &name, typename boost::enable_if<boost::is_object<T>,T>::type* = nullptr)
{
return sm.get_variable<T>(name);
}
template<class T>
auto get(const smart_library& sm, const std::string &name, typename boost::enable_if<boost::is_function<T>>::type* = nullptr)
{
return sm.get_function<T>(name);
}
template<class Class, class Signature>
auto get(const smart_library& sm, const std::string &name) -> typename detail::get_mem_fn_type<Class, Signature>::mem_fn
{
return sm.get_mem_fn<Class, Signature>(name);
}
} /* namespace experimental */
} /* namespace dll */
} /* namespace boost */
#endif /* BOOST_DLL_SMART_LIBRARY_HPP_ */