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
2010/11/16 Richard Guenther <richard.guenther@gmail.com>:
> 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?
The difference is that a dllexport implies an additional decoration.
An external visible function (for pe-coff in static libraries for
example) needs not necessarily be a dllexport symbol. But it is true
that a dllexport symbol is always externally visible.
> @@ -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?)
Well, I put it next to the dllimport_flag, which is btw also not just
exclusively to VAR_DECLs. I can move both flags down after the
comment.
> That said, why not simply add externally_visible when seeing dllexport?
> Why not make externally_visible use a flag (or intergrate that with
> visibility support)?
See above for reason.
> Richard.
>
Regards,
Kai
--
|? (\_/) This is Bunny. Copy and paste
| (='.'=) Bunny into your signature to help
| (")_(") him gain world domination