Re: [Boost-users] [Exception] Duplicate symbol error when using errinfo_api_function in static library

Subject: Re: [Boost-users] [Exception] Duplicate symbol error when using errinfo_api_function in static library
From: Emil Dotchevski (emildotchevski_at_[hidden])
Date: 2013-10-02 19:33:15

On Wed, Oct 2, 2013 at 4:20 PM, Niall Douglas <s_sourceforge_at_[hidden]>wrote:

> On 2 Oct 2013 at 14:48, Emil Dotchevski wrote:
>
> > > Then I have a main.cpp which creates an instance of ClassA and ClassB
> and
> > > links to the library which contains ClassA.o and ClassB.o. When I
> compile
> > > the main.cpp I get the linker error duplicate symbol for the
> > > errinfo_api_function object in ClassA.o and ClassB.o. If I remove the
> > > visibility=hidden flag, it links without problems. I am not an expert
> on
> > > the compiler flags, but I saw that many libraries use the
> visibility=hidden
> > > flag so I think it would be good, if my lib could also use it.
> >
> > Honestly I have no idea why this would happen. Anyone?
>
> Throwable types must *always* be marked with attribute visibility
> default. I assume this has been done correctly, but if it hasn't that
> might help explain the problem. See my doc on the issue at
> http://gcc.gnu.org/wiki/Visibility.
>

These are not throwable types. For example, errinfo_api_function is not a
throwable type.

-- 
Emil Dotchevski
Reverge Studios, Inc.
http://www.revergestudios.com/reblog/index.php?n=ReCode