gdb_test_no_output

[Michael Snyder]

Joel Brobecker wrote:
>> An oft-used feature of gdb_test is that, if the message string is
>> supplied but empty (""), no PASS/FAIL output is produced.  This is
>> used when you want to give a command to gdb without actually testing
>> anything.
> 
> It's very easy to implement the exact same behavior as gdb_test, but
> are we certain that this is a valuable capability?  Looking at the
> documentation for that function, one can find:
> 
>     # 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.)
> 
> The current implementation seems inconsistent; but also I don't think
> that is really makes that much difference whether the test generates
> a result or not.
> 
> But if that's what people want...

It used to be a frequently used "idiom" -- if you wanted to do a
"next", for instance, just to set up for the next thing that you
needed to test, you would say

     gdb_test "next" "" ""

and it wouldn't add anything superfluous to the test output.

I'm currently looking at replacing the regexp part of those
usages with ".*", but the behavior in general is still useful,
I think.

Michael