[Bug c++/43601] Enormous increase in DLL object files size in 4.5

[a14331990 at hotmail dot com]

--- Comment #16 from a14331990 at hotmail dot com  2010-05-15 06:01 ---
(In reply to comment #8)
> I think this is a bug the MingW maintainers should handle.
> 
> While I understand Andrew's position, it seems to me that this is nevertheless
> a definite regression from the user's perspective.
> 
> W.
> 

Yes, I think this is mostly a mingw bug, but I think developers of cygwin, a
very similar project had already resolved this issue, they had enabled
auto-import by default in ld, please follow this post
[PATCH] Silence ld auto-import warnings for pe-i386.
http://sourceware.org/ml/binutils/2009-02/msg00341.html
for details.
   With auto-import enabled by default in ld, there is no need to emit exported
inline functions in gcc code.
   See my workaround here:
FYI: GCC 4.5.0 on Mingw.org
http://forums.codeblocks.org/index.php/topic,12183.msg85066.html#msg85066


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43601

[Bug c++/43601] Enormous increase in DLL object files size in 4.5

[a14331990 at hotmail dot com]

--- Comment #17 from a14331990 at hotmail dot com  2010-05-15 09:29 ---
Created an attachment (id=20662)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20662&action=view)
enable auto-import in ld

This patch comes from a post by Dave Korn and is slightly modified by me
[PATCH] Silence ld auto-import warnings for pe-i386.
http://sourceware.org/ml/binutils/2009-02/msg00341.html


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43601

[Bug c++/43601] Enormous increase in DLL object files size in 4.5

[a14331990 at hotmail dot com]

--- Comment #18 from a14331990 at hotmail dot com  2010-05-15 09:31 ---
Created an attachment (id=20663)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20663&action=view)
don't emit dllexport'd inline functions

This patch is just a removal of nathan's code.
See
r147799 | nathan | 2009-05-22 22:57:15 +0800 (Fri, 22 May 2009) | 16 lines
in gcc svn log


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43601

[Bug c++/43601] Enormous increase in DLL object files size in 4.5

[a14331990 at hotmail dot com]

--- Comment #20 from a14331990 at hotmail dot com  2010-05-15 13:24 ---
(In reply to comment #19)
> Should not the options -fvisibility-inlines-hidden or -fvisibility=hidden fix
> this problem? Option found on http://gcc.gnu.org/wiki/Visibility.
> Note: The MinGW GCC 4.5.0-1 does not make smaller DLLs using above options.
> 
> 
> 
> 

I don't think these option can undo the change by nathan at 2009-05-22

r147799 | nathan | 2009-05-22 22:57:15 +0800 (Fri, 22 May 2009) | 16 lines

   gcc/
   * tree.c (handle_dll_attribute): Mark dllexport'd inlines as
   non-external.

   gcc/cp
   * decl2.c (decl_needed_p): Consider dllexport'd functions needed.
   * semantics.c (expand_or_defer_fn): Similarly.

   gcc/testsuite/
   * gcc.dg/dll-6.c: New test.
   * gcc.dg/dll-6a.c: Likewise.
   * gcc.dg/dll-7.c: Likewise.
   * gcc.dg/dll-7a.c: Likewise.
   * g++.dg/ext/dllexport2.C: Likewise.
   * g++.dg/ext/dllexport2a.cc: Likewise.



   BTW, say SORRY to nathan, your change is indeed useful for building
libstdc++ dll, but I have found an alternative approach. 

Indeed, the explanation page
http://gcc.gnu.org/wiki/Visibility
says "How to use the new C++ visibility support
In your header files, wherever you want an interface or API made public outside
the current DSO, place __attribute__((visibility("default"))) in struct, class
and function declarations you wish to make public (it's easier if you define a
macro as this). You don't need to specify it in the definition. Then, alter
your make system to pass -fvisibility=hidden to each call of GCC compiling a
source file.", 
this means to use these options, you should alter your header files first, but
wxwidgets source code apparently don't contain anything like
"__attribute__((visibility("default")))".
Correct me if I'm wrong.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43601