xref: /openbsd-src/gnu/usr.bin/perl/t/mro/recursion_dfs.t (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1#!./perl
2
3use strict;
4use warnings;
5BEGIN {
6    unless (-d 'blib') {
7        chdir 't' if -d 't';
8        @INC = '../lib';
9    }
10}
11
12require './test.pl';
13
14plan(skip_all => "Your system has no SIGALRM") if !exists $SIG{ALRM};
15plan(tests => 8);
16
17=pod
18
19These are like the 010_complex_merge_classless test,
20but an infinite loop has been made in the heirarchy,
21to test that we can fail cleanly instead of going
22into an infinite loop
23
24=cut
25
26# initial setup, everything sane
27{
28    package K;
29    our @ISA = qw/J I/;
30    package J;
31    our @ISA = qw/F/;
32    package I;
33    our @ISA = qw/H F/;
34    package H;
35    our @ISA = qw/G/;
36    package G;
37    our @ISA = qw/D/;
38    package F;
39    our @ISA = qw/E/;
40    package E;
41    our @ISA = qw/D/;
42    package D;
43    our @ISA = qw/A B C/;
44    package C;
45    our @ISA = qw//;
46    package B;
47    our @ISA = qw//;
48    package A;
49    our @ISA = qw//;
50}
51
52# A series of 8 aberations that would cause infinite loops,
53#  each one undoing the work of the previous
54my @loopies = (
55    sub { @E::ISA = qw/F/ },
56    sub { @E::ISA = qw/D/; @C::ISA = qw/F/ },
57    sub { @C::ISA = qw//; @A::ISA = qw/K/ },
58    sub { @A::ISA = qw//; @J::ISA = qw/F K/ },
59    sub { @J::ISA = qw/F/; @H::ISA = qw/K G/ },
60    sub { @H::ISA = qw/G/; @B::ISA = qw/B/ },
61    sub { @B::ISA = qw//; @K::ISA = qw/K J I/ },
62    sub { @K::ISA = qw/J I/; @D::ISA = qw/A H B C/ },
63);
64
65foreach my $loopy (@loopies) {
66    eval {
67        local $SIG{ALRM} = sub { die "ALRMTimeout" };
68        alarm(3);
69        $loopy->();
70        mro::get_linear_isa('K', 'dfs');
71    };
72
73    if(my $err = $@) {
74        if($err =~ /ALRMTimeout/) {
75            ok(0, "Loop terminated by SIGALRM");
76        }
77        elsif($err =~ /Recursive inheritance detected/) {
78            ok(1, "Graceful exception thrown");
79        }
80        else {
81            ok(0, "Unrecognized exception: $err");
82        }
83    }
84    else {
85        ok(0, "Infinite loop apparently succeeded???");
86    }
87}
88