Re: [boost] [Boost.DLL] Formal Review request

Subject: Re: [boost] [Boost.DLL] Formal Review request
From: Antony Polukhin (antoshkka_at_[hidden])
Date: 2014-10-05 02:12:25

2014-10-05 2:34 GMT+04:00 Niall Douglas <s_sourceforge_at_[hidden]>:

> On 4 Oct 2014 at 14:42, Mathias Gaunard wrote:
>
> > On 04/10/2014 13:24, Niall Douglas wrote:
> >
> > > Andrey, please list here three C++ compilers which had at least one
> > > version release in the past five years which doesn't provide a magic
> > > macro expanding out to the mangling of the enclosing function.
> >
> > What about MinGW?
>
> I just ran the following program on MinGW:
>
> #include <iostream>
> #include <typeinfo>
>
> template<class T> void doprint(T a)
> {
>   std::cout << __func__ << std::endl;
>   std::cout << __FUNCTION__ << std::endl;
>   std::cout << __PRETTY_FUNCTION__ << std::endl;
>   struct $$$ { };
>   std::cout << typeid($$$).name() << std::endl;
> }
> template<class T> struct doprint$$$___$$$ { };
>
> int main(void)
> {
>   doprint(1);
>   std::cout << typeid(doprint$$$___$$$<int>).name() << std::endl;
>   return 0;
> }
>
> It prints:
>
> doprint
> doprint
> void doprint(T) [with T = int]
> Z7doprintIiEvT_E3$$$
> 16doprint$$$___$$$IiE
>

I've enchanted the previous example and the results are not very good:

#include <typeinfo>
#include <iostream>
#include <boost/variant.hpp>

namespace foo {
namespace adl_barrier {
    BOOST_SYMBOL_EXPORT boost::variant<int, short>
export_me_function(boost::variant<int, short>, boost::variant<int, short>) {
        return 0;
    }

    BOOST_SYMBOL_EXPORT boost::variant<int, short> export_me_variable;
} // namespace adl_barrier

using adl_barrier::export_me_function;
using adl_barrier::export_me_variable;

}

template <boost::variant<int, short>& var>
struct printer {};

template <boost::variant<int, short>(&var)(boost::variant<int, short>,
boost::variant<int, short>)>
struct printer2 {};

int main() {
    std:: cout << typeid(printer2<foo::export_me_function>).name() <<
std::endl;
    std:: cout << typeid(printer<foo::export_me_variable>).name() <<
std::endl;
}

Code from above will output:
Linux:
8printer2ILZN3foo11adl_barrier18export_me_functionEN5boost7variantIisNS2_6detail7variant5void_ES6_S6_S6_S6_S6_S6_S6_S6_S6_S6_S6_S6_S6_S6_S6_S6_S6_EES7_EE
7printerILZN3foo11adl_barrier18export_me_variableEEE

Windows:
.?AU?$printer2@$1?export_me_function_at_adl_barrier_at_foo@
@YA?AV?$variant_at_HFUvoid__at_0detail@boost@@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023
@U1023_at_U1023@U1023_at_U1023@U10
23_at_U1023@U1023_at_U1023@U1023_at_U1023@U1023@@boost@@V45_at_0@Z@@
.?AU?$printer@$E?export_me_variable_at_adl_barrier_at_foo@@3V?$variant_at_HFUvoid_
@0detail_at_boost@@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023
@U1023_at_U
1023_at_U1023@U1023_at_U1023@U1023_at_U1023@@boost@@A@@

While we still need the following:
Linux:
_ZN3foo11adl_barrier18export_me_functionEN5boost7variantIisNS1_6detail7variant5void_ES5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_EES6_
_ZN3foo11adl_barrier18export_me_variableE

Windows:
?export_me_function_at_adl_barrier_at_foo@@YA?AV?$variant_at_HFUvoid__at_0detail@boost
@@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023
@U1023_at_U1
023_at_U1023@U1023_at_U1023@@boost@@V34_at_0@Z
?export_me_variable_at_adl_barrier_at_foo@@3V?$variant_at_HFUvoid__at_0detail@boost
@@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023@U1023_at_U1023
@U1023_at_U1023
@U1023_at_U1023@U1023@@boost@@A

Looks like such method is not very good, function definition has changed
(Linux:5 was transformed into 6, 1 was tranformed into 2; Windows: V34
changed into V45)... I'm afraid that there'll be more surprises

-- 
Best regards,
Antony Polukhin