[pph] New script to reproduce failures from a .log file (issue4601050)

This small script searches for the spawn line corresponding to a given
grep pattern inside a dejagnu log file.  If it finds the spawn line,
it executes it with any other arguments provided on the command line.

It's generally useful for cutting and pasting failed test cases.  I did
not find anything close to it in gcc/contrib, so I will be adding it
to trunk shortly.

Gab, Lawrence, this ought to simplify reproducing pph failures from
g++.log.  Feel free to add more functionality to it, or use it to
find writer and reader pairs in the log file and execute them separately.


Diego.


	* repro_fail: New.


--
This patch is available for review at http://codereview.appspot.com/4601050

On 6/9/11, Diego Novillo <dnovillo@google.com> wrote:
> This small script searches for the spawn line corresponding to a given
> grep pattern inside a dejagnu log file.  If it finds the spawn line,
> it executes it with any other arguments provided on the command line.
>
> It's generally useful for cutting and pasting failed test cases.  I did
> not find anything close to it in gcc/contrib, so I will be adding it
> to trunk shortly.
>
> Gab, Lawrence, this ought to simplify reproducing pph failures from
> g++.log.  Feel free to add more functionality to it, or use it to
> find writer and reader pairs in the log file and execute them separately.
>
>
> Diego.
>
>
> 	* repro_fail: New.
>
> diff --git a/contrib/repro_fail b/contrib/repro_fail
> new file mode 100755
> index 0000000..d5bce04
> --- /dev/null
> +++ b/contrib/repro_fail
> @@ -0,0 +1,49 @@
> +#!/bin/bash
> +#
> +# Script to reproduce a test failure from a dejagnu .log file
> +#
> +# Contributed by Diego Novillo <dnovillo@google.com>
> +#
> +# Copyright (C) 2011 Free Software Foundation, Inc.
> +#
> +# This file is part of GCC.
> +#
> +# GCC 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, or (at your option)
> +# any later version.
> +#
> +# GCC 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 GCC; see the file COPYING.  If not, write to
> +# the Free Software Foundation, 51 Franklin Street, Fifth Floor,
> +# Boston, MA 02110-1301, USA.
> +
> +if [ $# -lt 2 ] ; then
> +    echo "usage: $0 pattern file.log [additional-args]"
> +    echo
> +    echo "Finds the 'spawn' line matching PATTERN in FILE.LOG and executes"
> +    echo "the command with any arguments in ADDITIONAL-ARGS."
> +    echo
> +    exit 1
> +fi
> +
> +set -e
> +pattern=$1
> +logf=$2
> +shift 2
> +args="$@"
> +line=$(grep "^spawn .*$pattern" $logf | sed -e "s:^spawn ::")

line=$(sed -e "/^spawn .*$pattern/ ! d ; s/^spawn //" $logf)

Has one fewer process and one fewer pipe.  Sed is your friend.

I think this code fails when multiple lines match the pattern.
Pipe through head?

> +
> +if [ "$line" = "" ] ; then
> +    echo "Could not find a spawn command for pattern $1"
> +    exit 1
> +fi
> +
> +set -x +e
> +$line $args
> +exit $?
>
> --
> This patch is available for review at http://codereview.appspot.com/4601050
>

On Thu, Jun 9, 2011 at 13:48, Lawrence Crowl <crowl@google.com> wrote:

>
> line=$(sed -e "/^spawn .*$pattern/ ! d ; s/^spawn //" $logf)
>
> Has one fewer process and one fewer pipe.  Sed is your friend.

sed and I have a complicated relationship.  But, sure :)

> I think this code fails when multiple lines match the pattern.
> Pipe through head?

Yup.  It does.

I'm sure there will be other things, it's in contrib/ now.  I'll wait
until we've used it and expanded it a bit more and move it to trunk.


Diego.

On Jun  9, 2011, Lawrence Crowl <crowl@google.com> wrote:

> On 6/9/11, Diego Novillo <dnovillo@google.com> wrote:
>> +args="$@"

I'd keep args in "$@" and use "$@" instead of $args, so as to avoid
quoting issues.

>> +line=$(grep "^spawn .*$pattern" $logf | sed -e "s:^spawn ::")

> line=$(sed -e "/^spawn .*$pattern/ ! d ; s/^spawn //" $logf)

> Has one fewer process and one fewer pipe.  Sed is your friend.

I'd have written sed -n "s/^spawn \(.*$pattern\)/\1/p", but I'm not sure
it's more efficient.

It would be wise to first quote slashes in the pattern:

pattern=`echo "$pattern" | sed 's:/:\\/:g'`

>> +if [ "$line" = "" ] ; then

[ -z "$line" ]

Thanks, Diego,