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Stop truncate(word) from falling back to file name
[perl5.git] / t / comp / fold.t
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1#!./perl -w
2
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3# Uncomment this for testing, but don't leave it in for "production", as
4# we've not yet verified that use works.
5# use strict;
a5871da3 6
9a0c9949 7print "1..25\n";
76c3cfbe 8my $test = 0;
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9
10# Historically constant folding was performed by evaluating the ops, and if
11# they threw an exception compilation failed. This was seen as buggy, because
12# even illegal constants in unreachable code would cause failure. So now
13# illegal expressions are reported at runtime, if the expression is reached,
14# making constant folding consistent with many other languages, and purely an
15# optimisation rather than a behaviour change.
16
5f2d9966 17
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18sub failed {
19 my ($got, $expected, $name) = @_;
20
21 print "not ok $test - $name\n";
22 my @caller = caller(1);
23 print "# Failed test at $caller[1] line $caller[2]\n";
24 if (defined $got) {
25 print "# Got '$got'\n";
26 } else {
27 print "# Got undef\n";
28 }
29 print "# Expected $expected\n";
30 return;
31}
32
33sub like {
34 my ($got, $pattern, $name) = @_;
35 $test = $test + 1;
36 if (defined $got && $got =~ $pattern) {
37 print "ok $test - $name\n";
38 # Principle of least surprise - maintain the expected interface, even
39 # though we aren't using it here (yet).
40 return 1;
41 }
42 failed($got, $pattern, $name);
43}
44
45sub is {
46 my ($got, $expect, $name) = @_;
47 $test = $test + 1;
48 if (defined $got && $got eq $expect) {
49 print "ok $test - $name\n";
50 return 1;
51 }
52 failed($got, "'$expect'", $name);
53}
54
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55sub ok {
56 my ($got, $name) = @_;
57 $test = $test + 1;
58 if ($got) {
59 print "ok $test - $name\n";
60 return 1;
61 }
62 failed($got, "a true value", $name);
63}
64
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65my $a;
66$a = eval '$b = 0/0 if 0; 3';
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67is ($a, 3, 'constants in conditionals don\'t affect constant folding');
68is ($@, '', 'no error');
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69
70my $b = 0;
71$a = eval 'if ($b) {return sqrt -3} 3';
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72is ($a, 3, 'variables in conditionals don\'t affect constant folding');
73is ($@, '', 'no error');
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74
75$a = eval q{
76 $b = eval q{if ($b) {return log 0} 4};
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77 is ($b, 4, 'inner eval folds constant');
78 is ($@, '', 'no error');
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79 5;
80};
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81is ($a, 5, 'outer eval folds constant');
82is ($@, '', 'no error');
a5871da3 83
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84# warn and die hooks should be disabled during constant folding
85
86{
87 my $c = 0;
88 local $SIG{__WARN__} = sub { $c++ };
89 local $SIG{__DIE__} = sub { $c+= 2 };
90 eval q{
91 is($c, 0, "premature warn/die: $c");
92 my $x = "a"+5;
93 is($c, 1, "missing warn hook");
94 is($x, 5, "a+5");
95 $c = 0;
96 $x = 1/0;
97 };
98 like ($@, qr/division/, "eval caught division");
99 is($c, 2, "missing die hook");
100}
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101
102# [perl #20444] Constant folding should not change the meaning of match
103# operators.
104{
105 local *_;
106 $_="foo"; my $jing = 1;
107 ok scalar $jing =~ (1 ? /foo/ : /bar/),
108 'lone m// is not bound via =~ after ? : folding';
109 ok scalar $jing =~ (0 || /foo/),
110 'lone m// is not bound via =~ after || folding';
111 ok scalar $jing =~ (1 ? s/foo/foo/ : /bar/),
112 'lone s/// is not bound via =~ after ? : folding';
113 ok scalar $jing =~ (0 || s/foo/foo/),
114 'lone s/// is not bound via =~ after || folding';
115 $jing = 3;
116 ok scalar $jing =~ (1 ? y/fo// : /bar/),
117 'lone y/// is not bound via =~ after ? : folding';
118 ok scalar $jing =~ (0 || y/fo//),
119 'lone y/// is not bound via =~ after || folding';
120}
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121
122# [perl #78064] or print
123package other { # hide the "ok" sub
124 BEGIN { $^W = 0 }
125 print 0 ? not_ok : ok;
126 print " ", ++$test, " - print followed by const ? BEAR : BEAR\n";
127 print 1 ? ok : not_ok;
128 print " ", ++$test, " - print followed by const ? BEAR : BEAR (again)\n";
129 print 1 && ok;
130 print " ", ++$test, " - print followed by const && BEAR\n";
131 print 0 || ok;
132 print " ", ++$test, " - print followed by const || URSINE\n";
133 BEGIN { $^W = 1 }
134}
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135
136# or stat
137print "not " unless stat(1 ? INSTALL : 0) eq stat("INSTALL");
138print "ok ", ++$test, " - stat(const ? word : ....)\n";
139# in case we are in t/
140print "not " unless stat(1 ? TEST : 0) eq stat("TEST");
141print "ok ", ++$test, " - stat(const ? word : ....)\n";