[PATCH] [gdb/testsuite] Fix timeout in gdb.mi/mi-multi-commands.exp

[Tom de Vries]

On 9/3/24 13:43, Tom de Vries wrote:
> On aarch64-linux, with test-case gdb.mi/mi-multi-commands.exp once in a while
> I run into (edited for readability):
> ...
> (gdb) ^M
> <LOTS-OF-SPACES>-data-evaluate-expression $a^M
> -data-evaluate-^done,value="\"FIRST COMMAND\""^M
> expression $b(gdb) ^M
> ^M
> ^done,value="\"TEST COMPLETE\""^M
> (gdb) ^M
> PASS: $exp: args=: look for first command output, command length 236
> FAIL: $exp: args=: look for second command output, command length 236 (timeout)
> ...
> 
> This is more likely to trigger when running the test-case using
> taskset -c <cpu> (where in a big.little setup we pick a little cpu).
> 
> The setup here is that the test-case issues these two commands at once:
> ...
> -data-evaluate-expression $a
> -data-evaluate-expression $b
> ...
> where the length of the first command is artificially increased by prefixing
> it with spaces, show as <LOTS-OF-SPACES> above.
> 
> What happens is that gdb, after parsing the first command, executes it.
> Then the output of the first command intermixes with the echoing of the second
> command, which produces this line containing the first prompt:
> ...
> expression $b(gdb) ^M
> ...
> which doesn't match the \r\n prefix of the regexp supposed to consume the
> first prompt:
> ...
>             -re "\r\n$mi_gdb_prompt" {
> ...
> 
> Fix this by dropping the \r\n prefix.
> 

Pushed.

Thanks,
- Tom

> Tested on aarch64-linux.
> 
> PR testsuite/29781
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29781
> ---
>   gdb/testsuite/gdb.mi/mi-multi-commands.exp | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/gdb/testsuite/gdb.mi/mi-multi-commands.exp b/gdb/testsuite/gdb.mi/mi-multi-commands.exp
> index 3a2e774bddc..028e187366a 100644
> --- a/gdb/testsuite/gdb.mi/mi-multi-commands.exp
> +++ b/gdb/testsuite/gdb.mi/mi-multi-commands.exp
> @@ -103,7 +103,7 @@ proc run_test { args } {
>   		set seen_first_message true
>   		exp_continue
>   	    }
> -	    -re "\r\n$mi_gdb_prompt" {
> +	    -re "$mi_gdb_prompt" {
>   		gdb_assert $seen_first_message $gdb_test_name
>   	    }
>   	}
> 
> base-commit: a6ecb18b796b2a7342ab72d14c6bd440b718030f