Re: big endian i86

[Nathan Sidwell <nathan at codesourcery dot com>]

H.J. Lu wrote:
> On Thu, May 08, 2008 at 01:57:26PM +0100, Nathan Sidwell wrote:
> > Hi,
> > I have a bug report about i86-ld allowing you to create big endian i86 modules with:
> >   ld -EB ....
> >
> > The linker produces no errors, but the resultant file is marked with 
> > unknown architecture, and is pretty useless :)  Is there a rationale for 
> > not issuing an error at link time?  I notice elf32-i386.c lacks a 
>
> You may want to take a look at closest_target_match in ldlang.c.
> It matches -EB any with big endian ELF target like elf64-big
> or elf32-big.  I think closest_target_match is too simple for ELF
> target. We should at least check one or more of arch,
> elf_machine_code, elf_size_info.

How about having closest_target_match ignore elf{32,64}-{big,little} ? Those 
vectors are only added so you can do _something_ with the wrong endianness (as 
bfd/config.bfd tells us):

# If we support any ELF target, then automatically add support for the
# generic ELF targets.  This permits an objdump with some ELF support
# to be used on an arbitrary ELF file for anything other than
# relocation information.

but without relocation processing, there's not much linking you can do.

ok?

nathan

--
Nathan Sidwell    ::   http://www.codesourcery.com   ::         CodeSourcery

2008-05-13  Nathan Sidwell  <nathan@codesourcery.com>

	* ldlang.c (closest_target_match): Ignore generic elf vectors.

Index: ldlang.c
===================================================================
RCS file: /cvs/src/src/ld/ldlang.c,v
retrieving revision 1.284
diff -c -3 -p -r1.284 ldlang.c
*** ldlang.c	28 Apr 2008 12:45:33 -0000	1.284
--- ldlang.c	13 May 2008 14:53:56 -0000
*************** name_compare (char *first, char *second)
*** 2653,2659 ****
    stricpy (copy1, first);
    stricpy (copy2, second);
  
!   /* Remove size and endian strings from the name.  */
    strcut (copy1, "big");
    strcut (copy1, "little");
    strcut (copy2, "big");
--- 2653,2659 ----
    stricpy (copy1, first);
    stricpy (copy2, second);
  
!   /* Remove endian strings from the name.  */
    strcut (copy1, "big");
    strcut (copy1, "little");
    strcut (copy2, "big");
*************** closest_target_match (const bfd_target *
*** 2699,2704 ****
--- 2699,2711 ----
    if (target->flavour != original->flavour)
      return 0;
  
+   /* Ignore generic big and little endian elf vectors.  */
+   if ((!memcmp (target->name, "elf32", 5)
+        || !memcmp (target->name, "elf64", 5))
+       && (!strcmp (target->name + 5, "-big")
+ 	  || !strcmp (target->name + 5, "-little")))
+     return 0;
+ 
    /* If we have not found a potential winner yet, then record this one.  */
    if (winner == NULL)
      {