Re: [pushed] Support -prompt and -lbl in gdb_test (Re: [PATCH 5/5] Make gdb_test's question non-optional if specified)

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

On 5/18/22 16:13, Pedro Alves wrote:
> On 2022-05-18 13:36, Pedro Alves wrote:
>> On 2022-05-18 13:15, Tom de Vries wrote:
>>> On 5/18/22 13:01, Pedro Alves wrote:
>>>> -    if [llength $args]>2 then {
>>>> -    set message [lindex $args 2]
>>>> -    } else {
>>>> -    set message [lindex $args 0]
>>>> +    if { $message == "" } {
>>>> +    set message $command
>>>>        }
>>>
>>> This seems to cause:
>>> ...
>>> PATH: gdb.ada/exec_changed.exp: shell mv /home/vries/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.ada/exec_changed/first /home/vries/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.ada/exec_changed/common
>>> PATH: gdb.ada/exec_changed.exp: shell mv /home/vries/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.ada/exec_changed/common /home/vries/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.ada/exec_changed/first
>>> PATH: gdb.ada/exec_changed.exp: shell mv /home/vries/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.ada/exec_changed/second /home/vries/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.ada/exec_changed/common
>>> PATH: gdb.ada/exec_changed.exp: shell touch /home/vries/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.ada/exec_changed/common
>>> PATH: gdb.ada/exec_changed.exp: shell touch /home/vries/gdb_versions/devel/build/gdb/testsuite/outputs/gdb.ada/exec_changed/first
>>> ...
>>> because the interpretation of message "" changed:
>>> ...
>>> gdb_test "shell mv ${binfile} ${common_binfile}" ".*" ""
>>> ...
>>
>> Hmm...  Yeah...  We could revert most of the changes to gdb_test and just keep the parse_args
>> part.  However, IMO the old behavior is a misfeature, though.  I think tests should
>> always have a name.  E.g., if such a test hits an internal error, what message would
>> be used?
>>
>> The documentation of the option even says that if message is omitted, use the command
>> string as message:
>>
>>   # MESSAGE is an optional message to be printed.  If this is
>>   #   omitted, then the pass/fail messages use the command string as the
>>   #   message.  (If this is the empty string, then sometimes we don't
>>   #   call pass or fail at all; I don't understand this at all.)
>>
>> Also, gdb_test_multiple doesn't a distinction between explicit "" message and
>> not specified message, the only way to end up with an empty message is if command
>> is empty as well.  So AFAICS, this change (inadvertently) made gdb_test and
>> gdb_test_multiple behave the same in this respect.
>>
>> So how about we just fix the affected gdb_test invocations?
> 
> So I'm diffing testruns from before the patch vs after, and I think the vast
> majority of cases that weren't issuing a pass should do so.  With the new
> messages, we now get a ton of DUPLICATEs, which I'm fixing.
> 
> However, there are a few spots here and there where we really would prefer to
> not issue a pass, such as when we're testing something in a loop, and we don't
> know how many iterations there will be.
> 

Ack.  We could do something fancy like this, which would mean not having 
to update the msg or rewrite into gdb_test_multiple
...
message_squash {
    foreach var [seq 1 20] {
      gdb_test <cmd> <pat> <msg>
    }
}
...
and get:
...
PASS: <msg> (20x)
...
but perhaps that'll just confusion.

> Instead of going back to how it used to be, I'm thinking of adding a new
> option to gdb_test, "gdb_test -nopass".  The advantage of this approach is
> that we always have a message for the FAIL case this way, and, it's more
> explicit.  We could fix the "no message for the FAIL case" in the old implementation
> by delaying defaulting message to the command until after the pass case is added
> to user_code.  But the explict option still seems better to me, as it let's you
> specify a message different from the command, and only print it on FAIL.  The other
> approach would force the message to be the same as the command.

Makes sense to me.

Thanks,
- Tom