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Subject: Re: [boost] [Boost.DLL] Formal Review request
From: Antony Polukhin (antoshkka_at_[hidden])
Date: 2014-10-07 08:58:18


2014-10-07 3:51 GMT+04:00 Niall Douglas <s_sourceforge_at_[hidden]>:

> <...>
> Prints:
>
> 18$$magic$$_fprinterILZN21$$magic$$_adl_barrier18export_me_functionE7v
> ariantIis5void_S2_S2_ES3_EE
> 18$$magic$$_vprinterILZN21$$magic$$_adl_barrier18export_me_variableEEE
>
> Exported:
>
> __ZN3foo11adl_barrier18export_me_functionE7variantIis5void_S2_S2_ES3_
> __ZN3foo11adl_barrier18export_me_variableE
>
> ... which looks bang on. Simply replace the 8fprinter with 3foo and
> remove the $$magic$$_.
>

Still looks like something error-prone.

Actually, user could always get the list of mangled symbols using the
boost::dll::library_info class methods on a compiled binary. So instead of
using mangling voodoo macro and explicitly declaring exports in import
module, user can find all the export_me_* mangled names and import them
using any of the interfaces. Something close can be found in this example:
http://apolukhin.github.io/Boost.DLL/boost_dll/tutorial.html#boost_dll.tutorial.querying_libraries_for_symbols

... some dream of a nicest solution:
Add attribute [[abi_name "new_abi_name"]], remove all the *_alias methods
and member function, remove _ALIAS macro. Now user is free to do following
things:

// in plugin:
namespace foo {
namespace adl_barrier {

[[abi_name "export_me_function_1"]]
BOOST_SYMBOL_EXPORT boost::variant<int, short> export_me_function(
    boost::variant<int, short>, boost::variant<int, short>)
{
    return 0;
}

[[abi_name "export_me_variable_1"]]
BOOST_SYMBOL_EXPORT boost::variant<int, short> export_me_variable;
} // namespace adl_barrier
}

// in importer:
dll::shared_library lib(lib_path);
typedef boost::variant<int, short> vis_t;
auto f = lib.get<vis_t(vis_t, vis_t)>("export_me_function_1");
auto v = lib.get<vis_t>("export_me_variable_1");

Code from above looks nice, but requires abi_name attribute that was not
even proposed to C++ standardization and until now existed only in my head.

-- 
Best regards,
Antony Polukhin

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