xref: /openbsd-src/gnu/usr.bin/perl/t/mro/recursion_dfs.t (revision 9f11ffb7133c203312a01e4b986886bc88c7d74b)
1#!./perl
2
3BEGIN {
4    chdir 't' if -d 't';
5    require './test.pl';
6    set_up_inc('../lib');
7}
8
9use strict;
10use warnings;
11
12plan(skip_all => "Your system has no SIGALRM") if !exists $SIG{ALRM};
13plan(tests => 8);
14
15=pod
16
17These are like the 010_complex_merge_classless test,
18but an infinite loop has been made in the heirarchy,
19to test that we can fail cleanly instead of going
20into an infinite loop
21
22=cut
23
24# initial setup, everything sane
25{
26    package K;
27    our @ISA = qw/J I/;
28    package J;
29    our @ISA = qw/F/;
30    package I;
31    our @ISA = qw/H F/;
32    package H;
33    our @ISA = qw/G/;
34    package G;
35    our @ISA = qw/D/;
36    package F;
37    our @ISA = qw/E/;
38    package E;
39    our @ISA = qw/D/;
40    package D;
41    our @ISA = qw/A B C/;
42    package C;
43    our @ISA = qw//;
44    package B;
45    our @ISA = qw//;
46    package A;
47    our @ISA = qw//;
48}
49
50# A series of 8 aberations that would cause infinite loops,
51#  each one undoing the work of the previous
52my @loopies = (
53    sub { @E::ISA = qw/F/ },
54    sub { @E::ISA = qw/D/; @C::ISA = qw/F/ },
55    sub { @C::ISA = qw//; @A::ISA = qw/K/ },
56    sub { @A::ISA = qw//; @J::ISA = qw/F K/ },
57    sub { @J::ISA = qw/F/; @H::ISA = qw/K G/ },
58    sub { @H::ISA = qw/G/; @B::ISA = qw/B/ },
59    sub { @B::ISA = qw//; @K::ISA = qw/K J I/ },
60    sub { @K::ISA = qw/J I/; @D::ISA = qw/A H B C/ },
61);
62
63foreach my $loopy (@loopies) {
64    eval {
65        local $SIG{ALRM} = sub { die "ALRMTimeout" };
66        alarm(3);
67        $loopy->();
68        mro::get_linear_isa('K', 'dfs');
69    };
70
71    if(my $err = $@) {
72        if($err =~ /ALRMTimeout/) {
73            ok(0, "Loop terminated by SIGALRM");
74        }
75        elsif($err =~ /Recursive inheritance detected/) {
76            ok(1, "Graceful exception thrown");
77        }
78        else {
79            ok(0, "Unrecognized exception: $err");
80        }
81    }
82    else {
83        ok(0, "Infinite loop apparently succeeded???");
84    }
85}
86