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    e628bebd
    [Buildsystem] Provide macros for explicitly marking symbols as exported or private · e628bebd
    Steffen Müthing authored
    This patch adds a new header visibility.hh with macros DUNE_EXPORT and DUNE_PRIVATE
    to mark symbols as exported or private at the ABI level.
    
    While we do not explicitly mark any symbols as hidden, there are certain situations
    in which the compiler creates symbols with incorrect linkage, especially for singleton
    accessor methods for templated types and their embedded static variables, which involve
    the creation of weak symbols.
    
    The linker is then unable to merge those weak definitions, causing either a link-time
    failure (when building static libraries) or undefined runtime behaviour (dynamic libraries).
    
    This problem can be avoided by explicitly marking the singleton accessor methods as
    DUNE_EXPORT. For symmetry, there is also a DUNE_PRIVATE macro, but while it works, I don't
    see it used very much in the short term.
    e628bebd
    History
    [Buildsystem] Provide macros for explicitly marking symbols as exported or private
    Steffen Müthing authored
    This patch adds a new header visibility.hh with macros DUNE_EXPORT and DUNE_PRIVATE
    to mark symbols as exported or private at the ABI level.
    
    While we do not explicitly mark any symbols as hidden, there are certain situations
    in which the compiler creates symbols with incorrect linkage, especially for singleton
    accessor methods for templated types and their embedded static variables, which involve
    the creation of weak symbols.
    
    The linker is then unable to merge those weak definitions, causing either a link-time
    failure (when building static libraries) or undefined runtime behaviour (dynamic libraries).
    
    This problem can be avoided by explicitly marking the singleton accessor methods as
    DUNE_EXPORT. For symmetry, there is also a DUNE_PRIVATE macro, but while it works, I don't
    see it used very much in the short term.