[Patch] Make libstdc++'s abi_check more robust against readelf output format

[Ollie Wild]

Ok, for google/integration.  Please integrate to google/main and
google/gcc-4_6 as well.

Ollie

On Fri, May 20, 2011 at 10:05 AM, Simon Baldwin <simonb@google.com> wrote:
>
> Make libstdc++'s abi_check more robust against readelf output format.
>
> libstdc++-abi/abi_check in the libstdc++-v3 testsuite relies on a fixed
> number of space separated fields in readelf output.  However, the field
> count for readelf output can vary where the library contains OS or processor
> specific bindings, or other unknown bindings.
>
> This patch replaces the strings that readelf outputs for such bindings
> with alternative strings that use underscores in place of space.  It
> preserves the count of fields for such cases, and allows the awk statement
> that follows to find the desired field correctly with $n.
>
> OK for trunk?
>
> libstdc++-v3/ChangeLog:
> 2011-05-20  Simon Baldwin  <simonb@google.com>
>
>        * scripts/extract_symvers.in: Handle processor/OS specific or
>        unknown symbol binding strings from readelf.
>
>
> Index: libstdc++-v3/scripts/extract_symvers.in
> ===================================================================
> --- libstdc++-v3/scripts/extract_symvers.in     (revision 173951)
> +++ libstdc++-v3/scripts/extract_symvers.in     (working copy)
> @@ -52,6 +52,9 @@ SunOS)
>   ${readelf} ${lib} |\
>   sed -e 's/ \[<other>: [A-Fa-f0-9]*\] //' -e '/\.dynsym/,/^$/p;d' |\
>   egrep -v ' (LOCAL|UND) ' |\
> +  sed -e 's/ <processor specific>: / <processor_specific>:_/g' |\
> +  sed -e 's/ <OS specific>: / <OS_specific>:_/g' |\
> +  sed -e 's/ <unknown>: / <unknown>:_/g' |\
>   awk '{ if ($4 == "FUNC" || $4 == "NOTYPE")
>            printf "%s:%s\n", $4, $8;
>          else if ($4 == "OBJECT" || $4 == "TLS")