On 28 February 2018 at 18:10, Randall S. Becker <[email protected]> wrote:
> On February 28, 2018 11:46 AM, demerphq wrote:
>> On 28 February 2018 at 08:49, Jeff King <[email protected]> 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;
>> > };
>>
>> FWIW, this doesn't need to use CORE::die like that unless you have code that
>> overrides die() or CORE::GLOBAL::die, which would be pretty unusual.
>>
>> die() within $SIG{__DIE__} is special cased not to trigger $SIG{__DIE__}
>> again.
>>
>> Of course it doesn't hurt, but it might make a perl hacker do a double take
>> why you are doing it. Maybe add a comment like
>>
>> # using CORE::die to armor against overridden die()
>
> The problem is actually in git code in its test suite that uses perl inline,
> not in my test code itself. The difficulty I'm having is placing this
> appropriate so that the signal handler gets used throughout the test suite
> including in the perl -e invocations. This is more a lack of my own
> understanding of plumbing of git test framework rather than of using or
> coding perl.
Did you reply to the wrong mail?
Create a file like:
.../Git/DieTrap.pm
which would look like this:
package Git::DieTrap;
use strict;
use warnings;
SIG{__DIE__} = sub {
CORE::die @_ if $^S || !defined($^S);
print STDERR "fatal: @_";
exit 128;
};
1;
__END__
and then you would do:
export PERL5OPT=-MGit::DieTrap
before executing any tests. ANY use of perl from that point on will
behave as though it has:
use Git::DieTrap;
at the top of the script, be it a -e, or any other way that Perl code
is executed.
cheers,
Yves
--
perl -Mre=debug -e "/just|another|perl|hacker/"
