Re: [boost] [filesystem][iostreams][program_options] linker issues on msvc

Subject: Re: [boost] [filesystem][iostreams][program_options] linker issues on msvc
From: Vladimir Prus (vladimir_at_[hidden])
Date: 2009-11-30 02:31:12

Vladimir Prus wrote:

> Alexander Arhipenko wrote:

>> The reason is:
>> #include <boost/filesystem.hpp> --> includes <boost/path.hpp> -->
>> includes <boost/system/system_error.hpp> --> includes
>> <boost/system/error_code.hpp>
>> 
>> File boost/system/error_code.hpp has following declarations:
>> 
>> BOOST_SYSTEM_DECL const error_category &  get_system_category();
>> BOOST_SYSTEM_DECL const error_category &  get_generic_category();
>> 
>> So, when the header above is included in main.cpp, BOOST_SYSTEM_DECL unrolls to:
>> __declspec(dllimport).
>> And this causes the linker error.
>> 
>> As a result, library that links boost::filesystem should link boost::system.
> 
> Yes, and this:
> 
>     lib boost_filesystem
>     :
>     $(SOURCES).cpp
>     ../../system/build//boost_system
>     :
> 
> should be enough for that. I'll check why is that not working.

I've looked. Apparently, Boost.Filesystem not only uses Boost.System in its 
sources, but also uses it in inlined and/or template functions. Therefore, a
client of Boost.Filesystem will have direct references to Boost.System function
in it. And on Windows, for this to work, Boost.System library must be directly
linked with.

I've checked in a patch that adds necessary usage requirements to Boost.Filesystem,
see:

        https://svn.boost.org/trac/boost/changeset/58028

Thanks for the report!

- Volodya