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Date:	Thu, 03 Mar 2016 22:00:32 +0100
From:	"Juan Manuel Guerrero (juan DOT guerrero AT gmx DOT de) [via djgpp-workers AT delorie DOT com]" <djgpp-workers AT delorie DOT com>
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To:	djgpp-workers AT delorie DOT com
Subject:	Re: [winter-gcc AT bfw-online DOT de: DJGPP COFF relocation in absolute
	sections]
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Reply-To:	djgpp-workers AT delorie DOT com

Am 02.03.2016 14:47, schrieb Leon Winter:
> Hi,
>
>>> In the end the question is does the DJGPP port also need that symbols in absolute
>>> sections shall not be relocated or not?
>
>> I couldn't think of a good reason why we'd use absolute symbols
>> anyway, as they're usually used for hardware or OS hooks, and that
>> won't work for DJGPP as we relocate address "0" anyway.  ABS sections
>> would only be useful for constants but we don't use them for that I
>> think.
>
>>> Is DJGPP/COFF in this sense different to
>>> SCO/COFF?
>
> The outcome of the changes in binutils suggest that.
>
> Looking at the code at hand in binutils and my debugging session it appears to
> be that in my SCO scenario an absolute section also has
>     sec->output_section->vma == 0
> which might not be true in DJGPP.
>
> Attached patch works for me on SCO. Does it work for you, too?
>
> Best regards,
> Leon


After a little bit of testing during the last couple of days I thing that the
patch proposed by you seems to work for the DJGPP port too.  At a first glance
I thought you were trying to reintroduce the change objected by me in:

diff -aprNU5 binutils-2.25.orig/bfd/cofflink.c binutils-2.25/bfd/cofflink.c
--- binutils-2.25.orig/bfd/cofflink.c	2015-06-04 12:57:58 +0000
+++ binutils-2.25/bfd/cofflink.c	2015-06-04 13:22:24 +0000
@@ -2977,13 +2977,18 @@ _bfd_coff_generic_relocate_section (bfd
  	    }
  	  else
  	    {
  	      sec = sections[symndx];

+	      /* This does not work for the DJGPP port of binutils-2.25.
+	         This issue has already fixed in the master branch and
+	         will be removed in the next DJGPP port.  */
+#ifndef __DJGPP__
  	      /* If the output section has been discarded then ignore this reloc.  */
  	      if (sec->output_section->vma == 0)
  		continue;
+#endif

                val = (sec->output_section->vma
  		     + sec->output_offset
  		     + sym->n_value);
  	      if (! obj_pe (input_bfd))

But your patch seems to be a little bit different so it is ok for me.
It seems neither to break the binary nor to corrupt the debug sections
as the changes introduced with binutils-2.25 have done.
Please note that I have applied your patch to binutils 2.26 and not to
the current master branch or whatever.  I do not have a git system
available and I do nort want to check out the repository, so I hape that
there will be no surprises when your patch get applied to the next version.
I hope that we do not fix the SCO port at the cost of breaking the DJGPP
port again.

Regards,
Juan M.Guerrero

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