[PATCH, GDB] Re: Should rename ELFOSABI_LINUX into ELFOSABI_GNU, and drop ELFOSABI_HURD

[Thomas Schwinge <thomas at schwinge dot name>]

Hallo!

On Mon, 04 Jul 2011 12:55:55 +0200, I wrote:
> On Mon, 4 Jul 2011 09:15:26 +0200, Samuel Thibault <samuel.thibault@ens-lyon.org> wrote:
> > Matt Rice, le Sun 03 Jul 2011 23:42:10 -0700, a Ãcrit :
> > > On Sun, Jul 3, 2011 at 6:40 AM, Thomas Schwinge <thomas@schwinge.name> wrote:
> > > > On Thu, 30 Jun 2011 10:48:02 +0100, Nick Clifton <nickc@redhat.com> wrote:
> > > >> Â> [ELFOSABI_GNU]
> > > >>
> > > >> Approved - please apply.
> > > >
> > > > Applied, with the following additional changed:
> > > 
> > > Hi, It isn't immediately obvious to me how to fix it but this patch
> > > broke gdb compilation,
> > > 
> > > ELFOSABI_HURD and ELFOSABI_LINUX caused the respective i386gnu-tdep.c
> > > and i386-linux-tdep.c implementations to be used.  Not sure what to
> > > replace that with, with these being the same and/or missing.
> > 
> > I believe it should be turned into just one case (ELFOSABI_GNU), and
> > then use generic_elf_osabi_sniff_abi_tag_sections, as is done for
> > ELFOSABI_NONE, to distinguish between LINUX and HURD.
> 
> That's what I'm thinking too, and here is the simple patch -- completely
> untested.  Matt, are you interested in testing this?  The must be no
> regressions for GNU/Linux [...]

No regressions in the testsuite for i686-pc-linux-gnu.

Additional manual testing:

GNU/Hurd box:

    $ cp /bin/true true-h-0
    $ cp /bin/true true-h-3
    $ elfedit --output-osabi none true-h-0
    $ elfedit --output-osabi linux true-h-3

(Need to use ``--output-osabi linux'' until ``--output-osabi GNU'' is
supported by the installed binutils version.)

GNU/Linux box:

    $ cp /bin/true true-l-0
    $ cp /bin/true true-l-3
    $ elfedit --output-osabi none true-l-0
    $ elfedit --output-osabi linux true-l-3

Without the patch, on i686-pc-linux-gnu:

    $ for f in ~/tmp/true-*; do echo "* $(basename "$f"):" && gdb/gdb --batch -q -ex 'show osabi' "$f"; done
    * true-h-0:
    
    warning: A handler for the OS ABI "GNU/Hurd" is not built into this configuration
    of GDB.  Attempting to continue with the default i386 settings.
    
    The current OS ABI is "auto" (currently "GNU/Hurd").
    The default OS ABI is "GNU/Linux".
    * true-h-3:
    The current OS ABI is "auto" (currently "GNU/Linux").
    The default OS ABI is "GNU/Linux".
    * true-l-0:
    The current OS ABI is "auto" (currently "GNU/Linux").
    The default OS ABI is "GNU/Linux".
    * true-l-3:
    The current OS ABI is "auto" (currently "GNU/Linux").
    The default OS ABI is "GNU/Linux".

(true-h-3 should fail in the same way as true-h-0.)

With the patch, on i686-pc-linux-gnu:

    $ for f in ~/tmp/true-*; do echo "* $(basename "$f"):" && gdb/gdb --batch -q -ex 'show osabi' "$f"; done
    * true-h-0:
    
    warning: A handler for the OS ABI "GNU/Hurd" is not built into this configuration
    of GDB.  Attempting to continue with the default i386 settings.
    
    The current OS ABI is "auto" (currently "GNU/Hurd").
    The default OS ABI is "GNU/Linux".
    * true-h-3:
    
    warning: A handler for the OS ABI "GNU/Hurd" is not built into this configuration
    of GDB.  Attempting to continue with the default i386 settings.
    
    The current OS ABI is "auto" (currently "GNU/Hurd").
    The default OS ABI is "GNU/Linux".
    * true-l-0:
    The current OS ABI is "auto" (currently "GNU/Linux").
    The default OS ABI is "GNU/Linux".
    * true-l-3:
    The current OS ABI is "auto" (currently "GNU/Linux").
    The default OS ABI is "GNU/Linux".

All OK.

With the patch, on i686-unknown-gnu0.3:

    $ for f in ~/tmp/true-*; do echo "* $(basename "$f"):" && gdb/gdb --batch -q -ex 'show osabi' "$f"; done
    * true-h-0:
    The current OS ABI is "auto" (currently "GNU/Hurd").
    The default OS ABI is "GNU/Hurd".
    * true-h-3:
    The current OS ABI is "auto" (currently "GNU/Hurd").
    The default OS ABI is "GNU/Hurd".
    * true-l-0:
    
    warning: A handler for the OS ABI "GNU/Linux" is not built into this configuration
    of GDB.  Attempting to continue with the default i386 settings.
    
    The current OS ABI is "auto" (currently "GNU/Linux").
    The default OS ABI is "GNU/Hurd".
    * true-l-3:
    
    warning: A handler for the OS ABI "GNU/Linux" is not built into this configuration
    of GDB.  Attempting to continue with the default i386 settings.
    
    The current OS ABI is "auto" (currently "GNU/Linux").
    The default OS ABI is "GNU/Hurd".

All OK.

> 2011-07-04  Thomas Schwinge  <thomas@schwinge.name>
> 
> 	gdb/
> 	* osabi.c (generic_elf_osabi_sniffer) <ELFOSABI_GNU>: Handle in the
> 	same way as ELFOSABI_NONE.
> 	<ELFOSABI_LINUX, ELFOSABI_HURD>: Remove cases.
> 
> diff --git a/gdb/osabi.c b/gdb/osabi.c
> index a264924..7820ecb 100644
> --- a/gdb/osabi.c
> +++ b/gdb/osabi.c
> @@ -519,6 +519,11 @@ generic_elf_osabi_sniffer (bfd *abfd)
>           the base specification for that machine (there are no
>           OS-specific extensions).  In order to determine the real OS
>           in use we must look for OS-specific notes.  */
> +      /* Fall through.  */
> +
> +    case ELFOSABI_GNU:
> +      /* The same applies for ELFOSABI_GNU: this can mean GNU/Hurd, GNU/Linux,
> +         and possibly more.  */
>        bfd_map_over_sections (abfd,
>  			     generic_elf_osabi_sniff_abi_tag_sections,
>  			     &osabi);
> @@ -532,14 +537,6 @@ generic_elf_osabi_sniffer (bfd *abfd)
>        osabi = GDB_OSABI_NETBSD_ELF;
>        break;
>  
> -    case ELFOSABI_LINUX:
> -      osabi = GDB_OSABI_LINUX;
> -      break;
> -
> -    case ELFOSABI_HURD:
> -      osabi = GDB_OSABI_HURD;
> -      break;
> -
>      case ELFOSABI_SOLARIS:
>        osabi = GDB_OSABI_SOLARIS;
>        break;

OK for HEAD?


I now had a look at the complete ``Cygnus src tree'', and there is no
further use of ELFOSABI_HURD.  There is an additional definition of it in
winsup/cygwin/include/sys/elf_common.h (and ELFOSABI_GNU missing).  Is
that file still in active use?


GrÃÃe,
 Thomas

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