Re: [PATCH] gdb/testsuite: fix race in gdb.server/multi-ui-errors.exp

[Tom de Vries <tdevries@suse.de>]

On 5/24/23 18:29, Andrew Burgess wrote:
> After this commit:
> 
>    commit ed32754a8c7919feffc6ddb66ff1c532e4a4d1cd
>    Date:   Thu Mar 9 10:45:03 2023 +0100
> 
>        [gdb/testsuite] Fix gdb.server/multi-ui-errors.exp for remote target
> 
> I noticed the occasional failure in gdb.server/multi-ui-errors.exp,
> which looked like this:
> 
>    (gdb) PASS: gdb.server/multi-ui-errors.exp: interact with GDB's main UI
>    interrupt
>    (gdb)
>    Program received signal SIGINT, Interrupt.
>    0x00007ffff7d501e7 in nanosleep () from /lib64/libc.so.6
>    FAIL: gdb.server/multi-ui-errors.exp: interrupt (timeout)
>    PASS: gdb.server/multi-ui-errors.exp: interrupt arrived
>    p server_pid
>    $1 = 718174
>    (gdb) PASS: gdb.server/multi-ui-errors.exp: p server_pid
> 
> This is triggered by this code in gdb.server/multi-ui-errors.exp:
> 
>      gdb_test "interrupt"
> 
>      gdb_test_multiple "" "interrupt arrived" {
> 	-re "Program received signal SIGINT, Interrupt\\.\r\n" {
> 	    pass $gdb_test_name
> 	}
>      }
> 
> The problem here is that the first interrupt will trigger the prompt
> to be printed, and then, after some time the inferior will be
> interrupted.
> 
> However the default pattern for gdb_test includes a '$' end anchor.
> If expect see the prompt with nothing following it then everything is

Hi Andrew,

see -> sees

> fine, and the test passes.
> 
> However, if the interrupt is quick and so what expect sees is this:
> 
>    (gdb)
>    Program received signal SIGINT, Interrupt.
>    0x00007ffff7d501e7 in nanosleep () from /lib64/libc.so.6
> 
> In this case the end anchor means that the gdb_test fails to match,
> and eventually times out.
> 
> Fix this by passing -no-prompt-anchor to gdb_test.

thanks for fixing this.

LGTM.

Reviewed-by: Tom de Vries <tdevries@suse.de>

Thanks,
- Tom


> ---
>   gdb/testsuite/gdb.server/multi-ui-errors.exp | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gdb/testsuite/gdb.server/multi-ui-errors.exp b/gdb/testsuite/gdb.server/multi-ui-errors.exp
> index af83614fe55..47ded35bc86 100644
> --- a/gdb/testsuite/gdb.server/multi-ui-errors.exp
> +++ b/gdb/testsuite/gdb.server/multi-ui-errors.exp
> @@ -106,7 +106,7 @@ with_spawn_id $gdb_main_spawn_id {
>   # Get the gdbserver PID.
>   set gdbserver_pid 0
>   with_spawn_id $gdb_main_spawn_id {
> -    gdb_test "interrupt"
> +    gdb_test -no-prompt-anchor "interrupt"
>   
>       gdb_test_multiple "" "interrupt arrived" {
>   	-re "Program received signal SIGINT, Interrupt\\.\r\n" {
> 
> base-commit: 389971df23ca74092314dbde1303310a33766ba7