Re: [PATCH DejaGNU/GCC 0/1] Support per-test execution timeout factor

[Maciej W. Rozycki]

On Wed, 3 Jan 2024, Hans-Peter Nilsson wrote:

> >  The test execution timeout is different from the tool execution timeout 
> > where it is GCC execution that is being guarded against taking excessive 
> > amount of time on the test host rather than the resulting test case 
> > executable run on the target afterwards, as concerned here.  GCC already 
> > has a `dg-timeout-factor' setting for the tool execution timeout, but has 
> > no means to increase the test execution timeout.  The GCC side of these 
> > changes adds a corresponding `dg-test-timeout-factor' setting.
> 
> Hmm.  I think it would be more correct to emphasize that the 
> existing dg-timeout-factor affects both the tool execution *and* 
> the test execution, whereas your new dg-test-timeout-factor only 
> affects the test execution.  (And still measured on the host.)

 Not really, `dg-timeout-factor' is only applied to tool execution and it 
doesn't affect test execution.  Timeout value reporting used to be limited 
in DejaGNU, but you can enable it easily now by adding the DejaGNU patch 
series referred in the cover letter and see that `dg-timeout-factor' is 
ignored for test execution.

> Usually the compilation time is close to 0, so is this based on 
> an actual need more than an itchy "wart"?
> 
> Or did I miss something?

 Compilation is usually quite fast, but this is not always the case.  If 
you look at the tests that do use `dg-timeout-factor' in GCC, and some 
commits that added the setting, then you ought to find actual use cases.  
I saw at least one such a test that takes an awful lot of time here on a 
reasonably fast host machine and still passes where GCC has been built 
with optimisation enabled, but does time out in the compilation phase if 
the compiler has been built at -O0 for debugging purposes.  I'd have to 
chase it though if you couldn't find it as I haven't written the name 
down.

 So yes, `dg-timeout-factor' does have its use, but it is different from 
that of `dg-test-timeout-factor', hence the need for a separate setting.

  Maciej