On 28 February 2018 at 15:55, Randall S. Becker <rsbecker@xxxxxxxxxxxxx> wrote:
> On February 28, 2018 2:49 AM, Peff wrote:
>> On Wed, Feb 28, 2018 at 07:42:51AM +0000, Eric Wong wrote:
>>
>> > > > > a) We could override the meaning of die() in Git.pm. This feels
>> > > > > ugly but if it works, it would be a very small patch.
>> > > >
>> > > > Unlikely to work since I think we use eval {} to trap exceptions
>> > > > from die.
>> > > >
>> > > > > b) We could forbid use of die() and use some git_die() instead (but
>> > > > > with a better name) for our own error handling.
>> > > >
>> > > > Call sites may be dual-use: "die" can either be caught by an eval
>> > > > or used to show an error message to the user.
>> >
>> > <snip>
>> >
>> > > > > d) We could wrap each command in an eval {...} block to convert the
>> > > > > result from die() to exit 128.
>> > > >
>> > > > I prefer option d)
>> > >
>> > > FWIW, I agree with all of that. You can do (d) without an enclosing
>> > > eval block by just hooking the __DIE__ handler, like:
>> > >
>> > > $SIG{__DIE__} = sub {
>> > > print STDERR "fatal: @_\n";
>> > > exit 128;
>> > > };
>> >
>> > Looks like it has the same problems I pointed out with a) and b).
>>
>> You're right. I cut down my example too much and dropped the necessary
>> eval magic. Try this:
>>
>> -- >8 --
>> SIG{__DIE__} = sub {
>> CORE::die @_ if $^S || !defined($^S);
>> print STDERR "fatal: @_";
>> exit 128;
>> };
>>
>> eval {
>> die "inside eval";
>> };
>> print "eval status: $@" if $@;
>>
>> die "outside eval";
>> -- 8< --
>>
>> Running that should produce:
>>
>> $ perl foo.pl; echo $?
>> eval status: inside eval at foo.pl line 8.
>> fatal: outside eval at foo.pl line 12.
>> 128
>>
>> It may be getting a little too black-magic, though. Embedding in an eval is at
>> least straightforward, if a bit more invasive.
>
> I like this solution. The $64K question for me is how (a.k.a. where) to instrument this broadly instead of in each perl fragment in the test suite. The code:
>
> $SIG{__DIE__} = sub {
> CORE::die @_ if $^S || !defined($^S);
> print STDERR "fatal: @_";
> exit 128;
> };
>
> eval {
> die "inside eval";
> };
>
> print "eval status: $@" if $@;
>
> die "outside eval";
>
> as tested above, in NonStop results in an exit code of 128 whether run from a script or from stdin (a good thing). I'm happy to do the heavy lifting on this, but a bit more direction as to the implementation would help.
I would look into putting it into a module and then using the PERL5OPT
environment var to have it loaded automagically in any of your perl
scripts.
For instance if you put that code into a module called Git/DieTrap.pm
then you could do:
PERL5OPT=-MGit::DieTrap
In your test setup code assuming you have some. Then you don't need to
change any of your scripts just the test runner framework.
Yves
--
perl -Mre=debug -e "/just|another|perl|hacker/"
