Re: [xml] MSYS and MINGW: undefined reference to _imp__xmlFree

["Martin Schlemmer" <Martin Schlemmer nwu ac za>]

> > > On 2009/11/09 at 10:53 PM, Roumen Petrov <bugtrack roumenpetrov info> wrote:
> Martin Schlemmer wrote:
> > > > > On 11/8/2009 at 8:08 PM, Roumen Petrov <bugtrack roumenpetrov info> wrote:
> > > Roumen Petrov wrote:
> > > > Martin Schlemmer wrote:
> > > > > Hi,
> > > > [SNIP]
> > > > It seems to me Martin is right but proposed patch is not correct to me. 
> > > > I think that code has to set LIBXML_STATIC internally when is compiled 
> > > > for static library. As libxml build is libtool based we may use PIC 
> > > > definition. libtool when compile source for shared always set -DPIC .
> >
> > Idea was sort of to remove the need for that.  I will respond to Igor's mail 
> about that.
> > > Now with reverted commit
> > > http://git.gnome.org/cgit/libxml2/commit/?id=a194ccb8d19ddde94c2c04ddf197e6a 
>
> > > 629f7cc9b
> > > , i.e. restored "...defined(IN_LIBXML)..." plus following patch
> > > ==========================================
> > > diff --git a/libxml.h b/libxml.h
> > > index 3c44c83..1656ac2 100644
> > > --- a/libxml.h
> > > +++ b/libxml.h
> > > @@ -90,4 +90,7 @@ void __xmlGlobalInitMutexDestroy(void);
> > >   #endif
> > >   #endif
> > >   #endif
> > > +#ifndef PIC
> > > +#  define LIBXML_STATIC
> > > +#endif
> > >   #endif /* ! __XML_LIBXML_H__ */
> > > ==========================================
> >
> > This probably will break MSVC and Borland.  Also non-libtool-enabled builds 
> might also break,
> > as "-fPIC -DPIC" is added by libtool, but ignored by gcc on win32 as all code 
> on x86-win32 is already
> > position independent.
>
> No ! -fPIC is not set for gcc mingw target by libtool !
>
> For mingw target it is another definition that you already use in the
> patch proposed by you : #if defined(DLL_EXPORT) .... i.e. libtool for
> mingw target set -DDLL_EXPORT -DPIC. For gcc on linux it is -fPIC -DPIC
> . For other compilers as example -kPIC -DPIC.
> In brief one is compiler flag and another is common for all platforms -
> it is C preprocessor flag -DPIC.

Never mind here - I missed that it was in an internal header, and thus would not
have effected external projects linking against libxml.

> > Not sure what to suggest with this, but to check that with reverted commit 
> that xmlsec is indeed
> > built with -DLIBXML_STATIC if linking to the static version of the library.
>
> Don't mix preprocessor flags set by other projects when static linking
> with libxml is required.

Like Igor pointed out, LIBXML_STATIC needs to be defined if you link against the
static version for the current setup.  If using pkg-config for a static only build of
libxml, this is not an issue, but ...


Regards,
Martin


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