[Bug c++/47877] -fvisibility-inlines-hidden does not hide member template functions

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47877

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |documentation
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2016-11-21
                 CC|rguenther at suse dot de           |jason at gcc dot gnu.org,
                   |                            |rguenth at gcc dot gnu.org
     Ever confirmed|0                           |1

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  It looks like template instantiation somehow ends up using the
explicitely specified visibility from the class.  When
determine_visibility_from_class is called for the template
determine_hidden_inline () is false because of the processing_template_decl
check.  So the behavior is clearly on purpose and thus a documentation
issue(?):

/* Returns true iff DECL is an inline that should get hidden visibility
   because of -fvisibility-inlines-hidden.  */

static bool
determine_hidden_inline (tree decl)
{
  return (visibility_options.inlines_hidden
          /* Don't do this for inline templates; specializations might not be
             inline, and we don't want them to inherit the hidden
             visibility.  We'll set it here for all inline instantiations.  */
          && !processing_template_decl
          && TREE_CODE (decl) == FUNCTION_DECL
          && DECL_DECLARED_INLINE_P (decl)
          && (! DECL_LANG_SPECIFIC (decl)
              || ! DECL_EXPLICIT_INSTANTIATION (decl)));
}

so the reason is along non-inline specializations (not sure why we'd want to
avoid mixed visibility here).