[PATCH] ld: fix 32-bit mingw DLL symbol export bug

[PATCH] ld: fix 32-bit mingw DLL symbol export bug

[Oleg Tolmatcev]

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Hello,

I think there's a bug in ld on 32-bit Windows.Here is a tiny project
for reproducing the problem. https://github.com/oltolm/ld-mingw32-bug

A 32-bit DLL exports two stdcall functions "myfunc" and "myfunc64".
The functions would normally get exported as "myfunc@0" and
"myfunc64@0". The "DEF" file exports them as "myfunc" and "myfunc64"
without the decorations. When you run the executable it shows an error
message saying that it can not find "myfunc64". I think it happens
because the sorting in ld is wrong.

I think it should use the exported names "myfunc" and "myfunc64", but
instead it uses the decorated names "myfunc@0" or "myfunc65@0". The
ordering of functions in the DLL is different depending on which names
you use.

My patch changes ld to use undecorated exported names for sorting and
it seems to fix the problem. When I execute ctest in my project, it
runs successfully.

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From c5ffcde3277e3aec48f0f1f2689fd628b3972d2f Mon Sep 17 00:00:00 2001
From: oltolm <oleg.tolmatcev@gmail.com>
Date: Tue, 26 Dec 2023 14:42:39 +0100
Subject: [PATCH] ld: fix 32-bit mingw DLL symbol export bug

Signed-off-by: oltolm <oleg.tolmatcev@gmail.com>
---
 ld/deffilep.y | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/ld/deffilep.y b/ld/deffilep.y
index 33c8cf35c5..45f90306e3 100644
--- a/ld/deffilep.y
+++ b/ld/deffilep.y
@@ -610,12 +610,11 @@ cmp_export_elem (const def_file_export *e, const char *ex_name,
 {
   int r;
 
-  if ((r = are_names_equal (ex_name, e->name)) != 0)
+  if ((r = are_names_equal (its_name ? its_name : ex_name,
+			    e->its_name ? e->its_name : e->name)) != 0)
     return r;
   if ((r = are_names_equal (in_name, e->internal_name)) != 0)
     return r;
-  if ((r = are_names_equal (its_name, e->its_name)) != 0)
-    return r;
   return (ord - e->ordinal);
 }
 
-- 
2.43.0.windows.1

Re: [PATCH] ld: fix 32-bit mingw DLL symbol export bug

[Oleg Tolmatcev]

Hello,

can I ask about my patch, now that the release is near?

Best regards
Oleg Tolmatcev

Re: [PATCH] ld: fix 32-bit mingw DLL symbol export bug

[Nick Clifton]

Hi Oleg,

> can I ask about my patch, now that the release is near?

Yes you can.  Please can you point me at the patch ?
I seem to have lost it from my email queue. :-(

Cheers
   Nick

Re: [PATCH] ld: fix 32-bit mingw DLL symbol export bug

[Oleg Tolmatcev]

Am Fr., 19. Jan. 2024 um 12:40 Uhr schrieb Nick Clifton <nickc@redhat.com>:

> Yes you can.  Please can you point me at the patch ?
> I seem to have lost it from my email queue. :-(

Here it is https://sourceware.org/pipermail/binutils/2023-December/131416.html.

Re: [PATCH] ld: fix 32-bit mingw DLL symbol export bug

[Nick Clifton]

Hi Oleg,

>> Yes you can.  Please can you point me at the patch ?
>> I seem to have lost it from my email queue. :-(
> 
> Here it is https://sourceware.org/pipermail/binutils/2023-December/131416.html.

Thanks.

I have gone ahead and applied the patch.  I am not an expert
on win32 function call APIs, so I am assuming that your patch
is correct.  If people start to complain, then we will have to
take another look. :-)

Cheers
   Nick

Re: [PATCH] ld: fix 32-bit mingw DLL symbol export bug

[Oleg Tolmatcev]

Am Fr., 19. Jan. 2024 um 16:06 Uhr schrieb Nick Clifton <nickc@redhat.com>:


> I have gone ahead and applied the patch.  I am not an expert
> on win32 function call APIs, so I am assuming that your patch
> is correct.  If people start to complain, then we will have to
> take another look. :-)

Thanks. Can you close this ticket
https://sourceware.org/bugzilla/show_bug.cgi?id=21033? I fixed it in
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=6aadf8a04d162feb2afe3c41f5b36534d661d447.

Best regards
Oleg Tolmatcev