[gdb/testsuite] Handle unreachable network in server-connect.exp

  Hi,

When running gdb.server/server-connect.exp I run into:
...
FAIL: gdb.server/server-connect.exp: tcp6: connect to gdbserver using tcp6:::1
FAIL: gdb.server/server-connect.exp: tcp6-with-brackets: connect to gdbserver \
  using tcp6:[::1]
FAIL: gdb.server/server-connect.exp: udp6: connect to gdbserver using udp6:::1
FAIL: gdb.server/server-connect.exp: udp6-with-brackets: connect to gdbserver \
  using udp6:[::1]
...

The FAIL is caused by the fact that the ipv6 loopback address is not available:
...
PASS: gdb.server/server-connect.exp: tcp6: start gdbserver
target remote tcp6:::1:2347^M
A program is being debugged already.  Kill it? (y or n) y^M
tcp6:::1:2347: Network is unreachable.^M
(gdb) FAIL: gdb.server/server-connect.exp: tcp6: connect to gdbserver using tcp6:::1
...
This should be marked UNSUPPORTED rather than FAIL.

Furthermore, the test-case takes about 4 minutes, because the 'Network is
unreachable' response is not explicitly handled in gdb_target_cmd, so instead
it runs into the timeout case.

Fix this by handling the 'Network is unreachable' response as UNSUPPORTED.
This reduces testing time from 4 minutes to about 2 seconds.

Tested on x86_64-linux.

OK for trunk?

Thanks,
- Tom

[gdb/testsuite] Handle unreachable network in server-connect.exp

gdb/testsuite/ChangeLog:

2019-09-14  Tom de Vries  <tdevries@suse.de>

	* lib/gdbserver-support.exp (gdb_target_cmd): Return 2 (meaning
	UNSUPPORTED) for 'Network is unreachable' message.
	* gdb.server/server-connect.exp: Handle gdb_target_cmd returning 2.

---
 gdb/testsuite/gdb.server/server-connect.exp | 7 +++++--
 gdb/testsuite/lib/gdbserver-support.exp     | 6 +++++-
 2 files changed, 10 insertions(+), 3 deletions(-)
  

On Saturday, September 14 2019, Tom de Vries wrote:

> Hi,
>
> When running gdb.server/server-connect.exp I run into:
> ...
> FAIL: gdb.server/server-connect.exp: tcp6: connect to gdbserver using tcp6:::1
> FAIL: gdb.server/server-connect.exp: tcp6-with-brackets: connect to gdbserver \
>   using tcp6:[::1]
> FAIL: gdb.server/server-connect.exp: udp6: connect to gdbserver using udp6:::1
> FAIL: gdb.server/server-connect.exp: udp6-with-brackets: connect to gdbserver \
>   using udp6:[::1]
> ...
>
> The FAIL is caused by the fact that the ipv6 loopback address is not available:
> ...
> PASS: gdb.server/server-connect.exp: tcp6: start gdbserver
> target remote tcp6:::1:2347^M
> A program is being debugged already.  Kill it? (y or n) y^M
> tcp6:::1:2347: Network is unreachable.^M
> (gdb) FAIL: gdb.server/server-connect.exp: tcp6: connect to gdbserver using tcp6:::1
> ...
> This should be marked UNSUPPORTED rather than FAIL.
>
> Furthermore, the test-case takes about 4 minutes, because the 'Network is
> unreachable' response is not explicitly handled in gdb_target_cmd, so instead
> it runs into the timeout case.
>
> Fix this by handling the 'Network is unreachable' response as UNSUPPORTED.
> This reduces testing time from 4 minutes to about 2 seconds.
>
> Tested on x86_64-linux.
>
> OK for trunk?

Thanks for the patch.  It LGTM (I can't approve it though).


> Thanks,
> - Tom
>
> [gdb/testsuite] Handle unreachable network in server-connect.exp
>
> gdb/testsuite/ChangeLog:
>
> 2019-09-14  Tom de Vries  <tdevries@suse.de>
>
> 	* lib/gdbserver-support.exp (gdb_target_cmd): Return 2 (meaning
> 	UNSUPPORTED) for 'Network is unreachable' message.
> 	* gdb.server/server-connect.exp: Handle gdb_target_cmd returning 2.
>
> ---
>  gdb/testsuite/gdb.server/server-connect.exp | 7 +++++--
>  gdb/testsuite/lib/gdbserver-support.exp     | 6 +++++-
>  2 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/gdb/testsuite/gdb.server/server-connect.exp b/gdb/testsuite/gdb.server/server-connect.exp
> index 682fdaaeeb..96d3c4215a 100644
> --- a/gdb/testsuite/gdb.server/server-connect.exp
> +++ b/gdb/testsuite/gdb.server/server-connect.exp
> @@ -101,10 +101,13 @@ save_vars { GDB_TEST_SOCKETHOST } {
>  	    set gdbserver_gdbport [lindex $res 1]
>  	    set test "connect to gdbserver using $sockhost"
>  
> -	    if { [gdb_target_cmd $gdbserver_protocol $gdbserver_gdbport] == 0 } {
> +	    set res [gdb_target_cmd $gdbserver_protocol $gdbserver_gdbport]
> +	    if { $res == 0 } {
>  		pass $test
> -	    } else {
> +	    } elseif { $res == 1 }  {
>  		fail $test
> +	    } else {
> +		unsupported $test
>  	    }
>  	}
>      }
> diff --git a/gdb/testsuite/lib/gdbserver-support.exp b/gdb/testsuite/lib/gdbserver-support.exp
> index ade99c0ea1..5b5140b86c 100644
> --- a/gdb/testsuite/lib/gdbserver-support.exp
> +++ b/gdb/testsuite/lib/gdbserver-support.exp
> @@ -42,7 +42,8 @@
>  
>  #
>  # gdb_target_cmd
> -# Send gdb the "target" command.  Returns 0 on success, 1 on failure.
> +# Send gdb the "target" command.  Returns 0 on success, 1 on failure, 2 on
> +# unsupported.
>  # If specified, then ADDITIONAL_TEXT must match the text that comes after
>  # the connection message in order for the procedure to succeed.
>  #
> @@ -97,6 +98,9 @@ proc gdb_target_cmd { targetname serialport {additional_text ""} } {
>  		# Leave it there for the test to diagnose.
>  		return 1
>  	    }
> +	    -re ": Network is unreachable.\r\n.*$gdb_prompt $" {
> +		return 2
> +	    }
>  	    timeout {
>  		send_gdb ""
>  		break
  

>>>>> "Tom" == Tom de Vries <tdevries@suse.de> writes:

Tom> +	    set res [gdb_target_cmd $gdbserver_protocol $gdbserver_gdbport]
Tom> +	    if { $res == 0 } {
Tom>  		pass $test
Tom> -	    } else {
Tom> +	    } elseif { $res == 1 }  {
Tom>  		fail $test
Tom> +	    } else {
Tom> +		unsupported $test

Should this treatment be applied to the other callers of gdb_target_cmd?

I agree with Sergio that the patch is fine, but I wonder if a bigger
cleanup is warranted here.

thanks,
Tom