Re: [RFC] Unset tcl variable addr to avoid clashing

[Doug Evans <dje at google dot com>]

On Fri, Apr 10, 2015 at 4:51 AM, Yao Qi <qiyaoltc@gmail.com> wrote:
> From: Yao Qi <yao.qi@linaro.org>
>
> Hi,
> I see some tcl ERRORs in gdb.sum recently:
>
> ERROR: tcl error sourcing ../../../../../binutils-gdb/gdb/testsuite/gdb.base/dmsym.exp.
> ERROR: can't set "addr": variable is array
>     while executing
> "set addr "0x\[0-9a-zA-Z\]+""
>     (file "../../../../../binutils-gdb/gdb/testsuite/gdb.base/dmsym.exp" line 45)
>     invoked from within
> "source ../../../../../binutils-gdb/gdb/testsuite/gdb.base/dmsym.exp"
>     ("uplevel" body line 1)
>     invoked from within
> "uplevel #0 source ../../../../../binutils-gdb/gdb/testsuite/gdb.base/dmsym.exp"
>     invoked from within
> "catch "uplevel #0 source $test_file_name""
>
> It is OK to run single dmsym.exp.  This error is caused by the name
> clashing with coredump-filter.exp, and it can be reproduced,
>
>  $ make check RUNTESTFLAGS='coredump-filter.exp dmsym.exp exception.exp stepi-random-signal.exp'
>
> as variable addr is used in all of them.  This patch is to unset array
> addr, but manually unset variables isn't good to me.  Is there any
> approaches we can do to avoid name clashing?

Bleah. :-)
The first thing that comes to mind is of course a convention that
array globals must be prefixed with the name of the test.
OTOH gdb_base_coredump_filter_addr is painful.

>
> gdb/testsuite:
>
> 2015-04-10  Yao Qi  <yao.qi@linaro.org>
>
>         * gdb.base/coredump-filter.exp: Unset addr.
> ---
>  gdb/testsuite/gdb.base/coredump-filter.exp | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/gdb/testsuite/gdb.base/coredump-filter.exp b/gdb/testsuite/gdb.base/coredump-filter.exp
> index f3203be..2deb7b3 100644
> --- a/gdb/testsuite/gdb.base/coredump-filter.exp
> +++ b/gdb/testsuite/gdb.base/coredump-filter.exp
> @@ -196,3 +196,5 @@ foreach item $all_anon_corefiles {
>  with_test_prefix "loading and testing corefile for non-Private-Shared-Anon-File" {
>      test_disasm $non_private_shared_anon_file_core $main_addr 1
>  }
> +
> +unset addr

I'd prefer a comment explaining why that is there appear in the code
rather than having to go find it in commit logs or emails.