From: "H. J. Lu" <hjl@lucon.org>
To: Nick Clifton <nickc@redhat.com>
Cc: Andrew STUBBS <andrew.stubbs@st.com>, binutils@sources.redhat.com
Subject: Re: Problem setting the CONTENTS flag
Date: Wed, 26 Apr 2006 00:39:00 -0000 [thread overview]
Message-ID: <20060425202007.GA31738@lucon.org> (raw)
In-Reply-To: <444E3E55.2080308@redhat.com>
On Tue, Apr 25, 2006 at 04:20:53PM +0100, Nick Clifton wrote:
> HI H.J.
>
> >Here is an updated patch.
>
> There are a couple of minor problems with this version of the patch:
>
> >+ /* When we read a file or section BFD flags have been set, we don't
> >+ need section type and flags unless it is a linker created section.
> >+ They will be overridden in _bfd_elf_make_section_from_shdr
> >+ anyway. */
> >+ if ((!sec->flags && abfd->direction != read_direction)
> > || (sec->flags & SEC_LINKER_CREATED) != 0)
>
> I think that the comment could be reworded to be clearer. For example:
>
> A section without any flags or with the SEC_LINKER_CREATED flag
> must have its type and other flags set. Skip this for sections
> with no flags that have been read in, as this state must have been
> requested by the user, and it will be overridden by
> _bfd_elf_make_section_from_shdr anyway.
> >- /* FIXME: What if the output ELF section type has been set to
> >- something different? */
> >- if (elf_section_type (osec) == SHT_NULL)
> >+ /* Don't copy the output ELF section type from input if it has been
> >+ set to something different. */
> >+ if (osec->flags == isec->flags || !osec->flags)
> > elf_section_type (osec) = elf_section_type (isec);
>
> A section's type is not determined by its flags. Therefore it seems to
It is. See elf_fake_sections.
> be counter-intuitive to be testing the flags when we are concerned about
> the type. Also what happens if the output sections flags have been set
> to something other than the input section's flags, but the output
> section's type is SHT_NULL ? According to the ELF spec this would mean
> that the flags are undefined as well.
>
> I think that for this part of the patch the comment ought to be reworded
> and you ought to test for SHT_NULL and either change it or issue an
> error message. eg:
>
> /* Copy the output ELF section type from the input section type if
> the output section flags were copied from the input, or if the
> output section has no type or flags. */
> if (osec->flags == isec->flags
> || osec->flags == 0
> || elf_section_type (osec) == SHT_NULL)
> elf_section_type (osec) = elf_section_type (isec);
>
>
> Cheers
> Nick
>
I updated the comments.
H.J.
----
2006-04-21 H.J. Lu <hongjiu.lu@intel.com>
PR binutils/2593
* elf.c (_bfd_elf_new_section_hook): Don't set section ELF type
and flags if its BFD flags have been set.
(_bfd_elf_init_private_section_data): Don't copy the output ELF
section type from input if it has been set to something
different.
--- bfd/elf.c.flags 2006-04-24 20:11:58.000000000 -0700
+++ bfd/elf.c 2006-04-25 13:17:24.000000000 -0700
@@ -2487,10 +2487,13 @@ _bfd_elf_new_section_hook (bfd *abfd, as
bed = get_elf_backend_data (abfd);
sec->use_rela_p = bed->default_use_rela_p;
- /* When we read a file, we don't need section type and flags unless
- it is a linker created section. They will be overridden in
- _bfd_elf_make_section_from_shdr anyway. */
- if (abfd->direction != read_direction
+ /* When we read a file, we don't need to set ELF section type and
+ flags. They will be overridden in _bfd_elf_make_section_from_shdr
+ anyway. We will set ELF section type and flags for all linker
+ created sections. If user specifies BFD section flags, we will
+ set ELF section type and flags based on BFD section flags in
+ elf_fake_sections. */
+ if ((!sec->flags && abfd->direction != read_direction)
|| (sec->flags & SEC_LINKER_CREATED) != 0)
{
ssect = (*bed->get_sec_type_attr) (abfd, sec);
@@ -5906,9 +5909,11 @@ _bfd_elf_init_private_section_data (bfd
|| obfd->xvec->flavour != bfd_target_elf_flavour)
return TRUE;
- /* FIXME: What if the output ELF section type has been set to
- something different? */
- if (elf_section_type (osec) == SHT_NULL)
+ /* Don't copy the output ELF section type from input if the
+ output BFD section flags has been set to something different.
+ elf_fake_sections will set ELF section type based on BFD
+ section flags. */
+ if (osec->flags == isec->flags || !osec->flags)
elf_section_type (osec) = elf_section_type (isec);
/* Set things up for objcopy and relocatable link. The output
prev parent reply other threads:[~2006-04-25 21:24 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-04-21 18:08 Andrew STUBBS
2006-04-21 22:26 ` H. J. Lu
2006-04-21 23:32 ` Andreas Schwab
2006-04-23 22:13 ` H. J. Lu
2006-04-24 19:55 ` Andrew STUBBS
2006-04-25 16:37 ` Nick Clifton
2006-04-26 0:21 ` PATCH: binutils/2593: " H. J. Lu
2006-04-26 12:16 ` Nick Clifton
2006-04-26 0:39 ` H. J. Lu [this message]
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