Re: [PATCH 4/5] gdb/testsuite: change newline patterns used in gdb_test

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

On 5/2/23 13:13, Andrew Burgess wrote:
> Tom de Vries <tdevries@suse.de> writes:
> 
>> On 5/1/23 16:33, Andrew Burgess wrote:
>>> Tom de Vries <tdevries@suse.de> writes:
>>>
>>>> On 3/31/23 22:20, Andrew Burgess via Gdb-patches wrote:
>>>>> This commit makes two changes to how we match newline characters in
>>>>> the gdb_test proc.
>>>>
>>>> Hi,
>>>>
>>>> the -wrap used in gdb_test_multiple is defined in terms of gdb_test
>>>> semantics, but it doesn't seem to have been updated to match the new
>>>> behaviour in gdb_test.
>>>>
>>>> I've filed a PR about this regression (
>>>> https://sourceware.org/bugzilla/show_bug.cgi?id=30403 ).
>>>
>>> Sorry for any problems caused.  I'm not working today, but if this has
>>> not been addressed, I'll look at this on Tuesday.
>>
>> AFAIU it's a silent regression, so there are no problems in term of
>> FAILs, it's just that more work is required.
>>
>> FWIW, I think the root cause for introducing this regression silently is
>> that we try to implement the same thing in two different locations, and
>> it's just easy for things to get out of sync.  I recently fixed
>> something similar in commit 4fa173cfd79 ("[gdb/testsuite] Fix -wrap in
>> presence of -prompt in gdb_test_multiple"), that's why I noticed it.
> 
> So I believe the patch below brings gdb_test_multiple with '-wrap' back
> into line with gdb_test.  I also updated a couple of other places that
> used the same (old) gdb_test pattern.
> 
> There were nowhere near as many regressions with this change as with
> gdb_test.  Let me know what you think.
> 

I've applied the patch and tested it, and saw no regression.  I've also 
reviewed the patch and LGTM.

However, I've now also realized that the ^ bit is missing, which was 
also added in this patch series.

In other words, say we have:
...
gdb_test "print 1" "^.$decimal = 1"
...
which passes fine.

But then we want to annotate the PASS message with the captured 
$decimal, and rewrite into:
...
gdb_test_multiple "print 1" "" {
     -re -wrap "^.($decimal) = 1" {
         set var_nr $expect_output(1,string)
         pass "$gdb_test_name (var_nr: $var_nr)"
     }
}
...
This FAILs because ^ at the start of the pattern is not handled the same 
way by -wrap as by gdb_test.

Thanks,
- Tom