Why can't gcc-4.2.1 build usable libreoffice?

[Mikhail T.]

Hello!

I just finished building editors/libreoffice with gcc-4.2.1 -- had to
edit the port's Makefile to prevent it from picking a different
compiler. Everything built and installed, but libreoffice dies on
start-up (right after flashing the splash-window):

    (gdb) where
    #0  0x000000080596c1aa in cppu::__getTypeEntries ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #1  0x000000080596c333 in cppu::__queryDeepNoXInterface ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #2  0x000000080596d4a2 in cppu::WeakImplHelper_query ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #3  0x00000008116f2b03 in
    cppu::WeakImplHelper1<com::sun::star::lang::XEventListener>::queryInterface
    ()
       from /opt/lib/libreoffice/ure/lib/bootstrap.uno.so
    #4  0x0000000805970347 in
    cppu::OInterfaceContainerHelper::disposeAndClear ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #5  0x00000008059705b2 in
    cppu::OMultiTypeInterfaceContainerHelper::disposeAndClear ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #6  0x000000080593309f in cppu::OComponentHelper::dispose ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #7  0x0000000805963d00 in cppu::OFactoryComponentHelper::dispose ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #8  0x00000008116ec296 in stoc_smgr::OServiceManager::disposing ()
    from /opt/lib/libreoffice/ure/lib/bootstrap.uno.so
    #9  0x000000080596af05 in cppu::WeakComponentImplHelperBase::dispose ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #10 0x00000008116e6244 in stoc_smgr::ORegistryServiceManager::dispose ()
       from /opt/lib/libreoffice/ure/lib/bootstrap.uno.so
    #11 0x000000080596a573 in cppu::WeakComponentImplHelperBase::release ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #12 0x00000008059482f6 in (anonymous namespace)::createTypeRegistry ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #13 0x00000008059487bf in
    cppu::defaultBootstrap_InitialComponentContext ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #14 0x0000000805948918 in
    cppu::defaultBootstrap_InitialComponentContext ()
       from
    /opt/lib/libreoffice/program/../ure-link/lib/libuno_cppuhelpergcc3.so.3
    #15 0x000000080212f883 in
    desktop::Desktop::InitApplicationServiceManager ()
       from /opt/lib/libreoffice/program/libmergedlo.so
    #16 0x000000080211f362 in desktop::Desktop::Init () from
    /opt/lib/libreoffice/program/libmergedlo.so
    #17 0x0000000807622113 in InitVCL () from
    /opt/lib/libreoffice/program/libvcllo.so
    #18 0x0000000807623151 in ImplSVMain () from
    /opt/lib/libreoffice/program/libvcllo.so
    #19 0x00000008076232d5 in SVMain () from
    /opt/lib/libreoffice/program/libvcllo.so
    #20 0x000000080214942e in soffice_main () from
    /opt/lib/libreoffice/program/libmergedlo.so
    #21 0x0000000000400773 in main ()

I do not blame the office@ team -- the port did not want to use
gcc-4.2.1, I forced it to. But I'd like to know, what is wrong with the
compiler shipped by FreeBSD-9.1 (and the only one, if WITHOUT_CLANG is
defined), that prevents building a healthy libreoffice?

Is there a bug fixed in gcc-4.6? Or is it some (incorrect) assumption
made by libreoffice code? Thank you,

    -mi