This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [patch lto/c++/middle-end/windows]: Fix handling of dllexport for LTO as externally_visible
> On Tue, Nov 16, 2010 at 11:46 AM, Kai Tietz <Kai.Tietz@onevision.com> wrote:
> > Hello,
> >
> > this patch introduces an new flag for dllexport (likewise to the already
> > existing DLLIMPORT flag) to structure tree_decl_with_vis in tree.h header..
> > As some places still dependent on checking explicit for
> > dllimport/dllexport attribute, I didn't omitted here the the attribute
> > node copy. This is maybe something for 4.7 gcc.
> >
> > ChangeLog
> >
> > ? ? ? ?* config/i386/winnt-cxx.c (maybe_add_dllexport): Set
> > DECL_DLLEXPORT_P.
> > ? ? ? ?* config/i386/winnt.c (i386_pe_determine_dllexport_p): Use
> > DECL_DLLEXPORT_P
> > ? ? ? ?instead of doing attribute lookup.
> > ? ? ? ?* tree.c (merge_dllimport_decl_attributes): Likewise.
> > ? ? ? ?(handle_dll_attribute): Set DECL_DLLEXPORT_P flag.
> > ? ? ? ?* lto-streamer-in.c (unpack_ts_decl_with_vis_value_fields):
> > Restore dllexport flag.
> > ? ? ? ?* lto-streamer-out.c (pack_ts_decl_with_vis_value_fields): Save
> > dllexport flag.
> > ? ? ? ?* tree-emutls.c (new_emutls_decl): Copy DECL_DLLEXPORT_P flag.
> > ? ? ? ?* tree.h (tree_decl_with_vis):Add new member dllexport_flag.
> > ? ? ? ?(DECL_DLLEXPORT_P): New macro.
> > ? ? ? ?* ipa.c (cgraph_externally_visible_p): Check for DECL_DLLEXPORT_P.
> > ? ? ? ?(varpool_externally_visible_p): Likewise.
> > ? ? ? ?*cp/optimize.c (maybe_clone_body): Copy DECL_DLLEXPORT_P, too.
> >
> > Tested for x86_64-w64-mingw32, i686-w64-mingw32, and i686-pc-cygwin. Ok
> > for apply?
>
> What's the difference between externally_visible and dllexport?
>
> @@ -3121,6 +3125,7 @@ struct GTY(()) tree_decl_with_vis {
> unsigned in_text_section : 1;
> unsigned in_constant_pool : 1;
> unsigned dllimport_flag : 1;
> + unsigned dllexport_flag : 1;
> /* Don't belong to VAR_DECL exclusively. */
> unsigned weak_flag : 1;
>
> please keep 1) flags in 8 bit groups, 2) add it below the right comment
> (it doesn't belong to VAR_DECLs exclusively, right?)
>
> That said, why not simply add externally_visible when seeing dllexport?
I would not be too offended by doing that.
> Why not make externally_visible use a flag (or intergrate that with
> visibility support)?
We already have flag in cgraph node, so we search for it in declaration
constant number of times (I think twice, once for visibility pass and once for
whole_program_visibility), so adding flag seems bit redundant.
We can also just search for dllexport attribute at the same place, it would
not be terribly expensive either.
Honza
>
> Richard.
>
> > Regards,
> > ?i.A. Kai Tietz
> >
> > | ?(\_/) ?This is Bunny. Copy and paste Bunny
> > | (='.'=) into your signature to help him gain
> > | (")_(") world domination.
> >
> >