Re: [PATCH v4] Resurrect gdb-add-index as a contrib script

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

On Sun, 03 Nov 2013 22:57:59 +0100, Samuel Bronson wrote:
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -32,6 +32,9 @@
>    Before, the former would print "<optimized out>", and the latter
>    "*value not available*".
>  
> +* New script contrib/gdb-add-index.sh for adding .gdb_index sections
> +  to binaries.
> +
>  * Python scripting
>  
>    ** Frame filters and frame decorators have been added.

Eli usually reviews the NEWS part.


> diff --git a/gdb/contrib/gdb-add-index.sh b/gdb/contrib/gdb-add-index.sh
> new file mode 100755
> index 0000000..145073a
> --- /dev/null
> +++ b/gdb/contrib/gdb-add-index.sh
> @@ -0,0 +1,68 @@
> +#! /bin/sh
> +
> +# Add a .gdb_index section to a file.
> +
> +# Copyright (C) 2010, 2012-2013 Free Software Foundation, Inc.
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 3 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>.
> +
> +# This program assumes gdb and objcopy are in $PATH.
> +# If not, or you want others, pass the following in the environment
> +GDB=${GDB:=gdb}
> +OBJCOPY=${OBJCOPY:=objcopy}
> +
> +myname="${0##*/}"
> +
> +if test $# != 1; then
> +    echo "usage: $myname FILE" 1>&2
> +    exit 1
> +fi
> +
> +file="$1"
> +
> +if test ! -r "$file"; then
> +    echo "$myname: unable to access: $file" 1>&2
> +    exit 1
> +fi
> +
> +dir="${file%/*}"
> +test "$dir" = "$file" && dir="."
> +index="${file}.gdb-index"

You should test here $index does not exist; or just rm -f it.
Such existing file may confuse this script.

> +
> +# Ensure intermediate index file is removed when we exit.
> +trap "rm -f $index" 0
> +
> +$GDB --batch -nx -iex 'set auto-load no' \
> +    -ex "file $file" -ex "save gdb-index $dir" || {
> +    # Just in case.
> +    status=$?
> +    echo "$myname: gdb error generating index" 1>&2

You could say also $file here.
For example during rpmbuild gdb-add-index is run but the script does not have
'set -x' so gdb-add-index's errors appear between other messages.


> +    exit $status
> +}
> +
> +# In some situations gdb can exit without creating an index.  This is
> +# not an error.
> +# E.g., if $file is stripped.  This behaviour is akin to stripping an
> +# already stripped binary, it's a no-op.
> +status=0
> +
> +if test -f "$index"; then
> +    $OBJCOPY --add-section .gdb_index="$index" \
> +	--set-section-flags .gdb_index=readonly "$file" "$file"
> +    status=$?
> +else
> +    echo "$myname: No index was created." 1>&2

You could say also $file here.

> +    echo "[Was there anything to index? Was there already an index?]" 1>&2

       echo "$myname: [Was there anything to index? Was there already an index?]" 1>&2

> +fi
> +
> +exit $status
> -- 
> 1.8.4.rc3


OK with these changes from me.


Thanks,
Jan