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

[Nick Clifton]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=d544a1dca23469d212e7e9edc754487352c5f042

commit d544a1dca23469d212e7e9edc754487352c5f042
Author: Oleg Tolmatcev <oleg.tolmatcev@gmail.com>
Date:   Fri Jan 19 15:02:45 2024 +0000

    ld: fix 32-bit mingw DLL symbol export bug
    
    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 cannot
    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.

Diff:
---
 ld/deffilep.y | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/ld/deffilep.y b/ld/deffilep.y
index 4967ff116c5..fb12e6dc7b8 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);
 }