Re: [PATCH 1/3] add testcases for function definitions

[David Smith <dsmith at redhat dot com>]

On 11/09/2015 12:07 PM, Josh Stone wrote:
> On 11/09/2015 12:57 AM, Zhou Wenjian wrote:
>> +foreach runtime [get_runtime_list] {
>> +    if {$runtime != ""} {
>> +	stap_run $srcdir/$subdir/$test.stp no_load ${all_pass_string}${all_pass_string}${all_pass_string}${all_pass_string}${all_pass_string} \
>> +	    --runtime=$runtime
>> +    } else {
>> +	stap_run $srcdir/$subdir/$test.stp no_load ${all_pass_string}${all_pass_string}${all_pass_string}${all_pass_string}${all_pass_string}
>> +    }
>> +}
> 
> I disagree with using repetition like this for "exact" results.  The
> string already has regex repetition built in:
> 
>   set all_pass_string "(systemtap test success\r\n)+"

Ah, I didn't know it did that.

> '+' means match one or more, greedily.  Repeating this expression on top
> of itself creates a bad case for the regex engine to backtrack.
> (It will work, but slowly.)

Hmm, having repetitions of the all_pass_string *should* work, but
doesn't. My guess would be that this used to work on older versions of
tcl/expect, but doesn't work now. The end-of-line handling has always
been iffy in tcl/expect.

> IMO we ought to make stap_run ensure nothing comes *after* the expected
> output string.  If there are tests that are legitimately printing more
> output, those are the ones we should be fixing.

That's a good idea. I'll try to look into it in the near future.

> Maybe we could also add the string without repetition, something like:
> 
>   set pass_string "systemtap test success\r\n"
>   set all_pass_string "($pass_string)+"
> 
> Then you can use "($pass_string){5}" if you really want exactly 5
> matches.  But stap_run should still make sure nothing comes after that.
> 
> 


-- 
David Smith
dsmith@redhat.com
Red Hat
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