xref: /openbsd-src/gnu/usr.bin/perl/dist/constant/t/constant.t (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1#!./perl -T
2
3use warnings;
4use vars qw{ @warnings $fagwoosh $putt $kloong};
5BEGIN {				# ...and save 'em for later
6    $SIG{'__WARN__'} = sub { push @warnings, @_ }
7}
8END { @warnings && print STDERR join "\n- ", "accumulated warnings:", @warnings }
9
10
11use strict;
12use Test::More tests => 105;
13my $TB = Test::More->builder;
14
15BEGIN { use_ok('constant'); }
16
17use constant PI		=> 4 * atan2 1, 1;
18
19ok defined PI,                          'basic scalar constant';
20is substr(PI, 0, 7), '3.14159',         '    in substr()';
21
22sub deg2rad { PI * $_[0] / 180 }
23
24my $ninety = deg2rad 90;
25
26cmp_ok abs($ninety - 1.5707), '<', 0.0001, '    in math expression';
27
28use constant UNDEF1	=> undef;	# the right way
29use constant UNDEF2	=>	;	# the weird way
30use constant 'UNDEF3'		;	# the 'short' way
31use constant EMPTY	=> ( )  ;	# the right way for lists
32
33is UNDEF1, undef,       'right way to declare an undef';
34is UNDEF2, undef,       '    weird way';
35is UNDEF3, undef,       '    short way';
36
37# XXX Why is this way different than the other ones?
38my @undef = UNDEF1;
39is @undef, 1;
40is $undef[0], undef;
41
42@undef = UNDEF2;
43is @undef, 0;
44@undef = UNDEF3;
45is @undef, 0;
46@undef = EMPTY;
47is @undef, 0;
48
49use constant COUNTDOWN	=> scalar reverse 1, 2, 3, 4, 5;
50use constant COUNTLIST	=> reverse 1, 2, 3, 4, 5;
51use constant COUNTLAST	=> (COUNTLIST)[-1];
52
53is COUNTDOWN, '54321';
54my @cl = COUNTLIST;
55is @cl, 5;
56is COUNTDOWN, join '', @cl;
57is COUNTLAST, 1;
58is((COUNTLIST)[1], 4);
59
60use constant ABC	=> 'ABC';
61is "abc${\( ABC )}abc", "abcABCabc";
62
63use constant DEF	=> 'D', 'E', chr ord 'F';
64is "d e f @{[ DEF ]} d e f", "d e f D E F d e f";
65
66use constant SINGLE	=> "'";
67use constant DOUBLE	=> '"';
68use constant BACK	=> '\\';
69my $tt = BACK . SINGLE . DOUBLE ;
70is $tt, q(\\'");
71
72use constant MESS	=> q('"'\\"'"\\);
73is MESS, q('"'\\"'"\\);
74is length(MESS), 8;
75
76use constant LEADING	=> " \t1234";
77cmp_ok LEADING, '==', 1234;
78is LEADING, " \t1234";
79
80use constant ZERO1	=> 0;
81use constant ZERO2	=> 0.0;
82use constant ZERO3	=> '0.0';
83is ZERO1, '0';
84is ZERO2, '0';
85is ZERO3, '0.0';
86
87{
88    package Other;
89    use constant PI	=> 3.141;
90}
91
92cmp_ok(abs(PI - 3.1416), '<', 0.0001);
93is Other::PI, 3.141;
94
95use constant E2BIG => $! = 7;
96cmp_ok E2BIG, '==', 7;
97# This is something like "Arg list too long", but the actual message
98# text may vary, so we can't test much better than this.
99cmp_ok length(E2BIG), '>', 6;
100
101is @warnings, 0 or diag join "\n- ", "unexpected warning:", @warnings;
102@warnings = ();		# just in case
103undef &PI;
104ok @warnings && ($warnings[0] =~ /Constant sub.* undefined/) or
105  diag join "\n", "unexpected warning", @warnings;
106shift @warnings;
107
108is @warnings, 0, "unexpected warning";
109
110my $curr_test = $TB->current_test;
111use constant CSCALAR	=> \"ok 35\n";
112use constant CHASH	=> { foo => "ok 36\n" };
113use constant CARRAY	=> [ undef, "ok 37\n" ];
114use constant CCODE	=> sub { "ok $_[0]\n" };
115
116my $output = $TB->output ;
117print $output ${+CSCALAR};
118print $output CHASH->{foo};
119print $output CARRAY->[1];
120print $output CCODE->($curr_test+4);
121
122$TB->current_test($curr_test+4);
123
124eval q{ CCODE->{foo} };
125ok scalar($@ =~ /^Constant is not a HASH/);
126
127
128# Allow leading underscore
129use constant _PRIVATE => 47;
130is _PRIVATE, 47;
131
132# Disallow doubled leading underscore
133eval q{
134    use constant __DISALLOWED => "Oops";
135};
136like $@, qr/begins with '__'/;
137
138# Check on declared() and %declared. This sub should be EXACTLY the
139# same as the one quoted in the docs!
140sub declared ($) {
141    use constant 1.01;              # don't omit this!
142    my $name = shift;
143    $name =~ s/^::/main::/;
144    my $pkg = caller;
145    my $full_name = $name =~ /::/ ? $name : "${pkg}::$name";
146    $constant::declared{$full_name};
147}
148
149ok declared 'PI';
150ok $constant::declared{'main::PI'};
151
152ok !declared 'PIE';
153ok !$constant::declared{'main::PIE'};
154
155{
156    package Other;
157    use constant IN_OTHER_PACK => 42;
158    ::ok ::declared 'IN_OTHER_PACK';
159    ::ok $constant::declared{'Other::IN_OTHER_PACK'};
160    ::ok ::declared 'main::PI';
161    ::ok $constant::declared{'main::PI'};
162}
163
164ok declared 'Other::IN_OTHER_PACK';
165ok $constant::declared{'Other::IN_OTHER_PACK'};
166
167@warnings = ();
168eval q{
169    no warnings;
170    use warnings 'constant';
171    use constant 'BEGIN' => 1 ;
172    use constant 'INIT' => 1 ;
173    use constant 'CHECK' => 1 ;
174    use constant 'END' => 1 ;
175    use constant 'DESTROY' => 1 ;
176    use constant 'AUTOLOAD' => 1 ;
177    use constant 'STDIN' => 1 ;
178    use constant 'STDOUT' => 1 ;
179    use constant 'STDERR' => 1 ;
180    use constant 'ARGV' => 1 ;
181    use constant 'ARGVOUT' => 1 ;
182    use constant 'ENV' => 1 ;
183    use constant 'INC' => 1 ;
184    use constant 'SIG' => 1 ;
185    use constant 'UNITCHECK' => 1;
186};
187
188my @Expected_Warnings =
189  (
190   qr/^Constant name 'BEGIN' is a Perl keyword at/,
191   qr/^Constant subroutine BEGIN redefined at/,
192   qr/^Constant name 'INIT' is a Perl keyword at/,
193   qr/^Constant name 'CHECK' is a Perl keyword at/,
194   qr/^Constant name 'END' is a Perl keyword at/,
195   qr/^Constant name 'DESTROY' is a Perl keyword at/,
196   qr/^Constant name 'AUTOLOAD' is a Perl keyword at/,
197   qr/^Constant name 'STDIN' is forced into package main:: a/,
198   qr/^Constant name 'STDOUT' is forced into package main:: at/,
199   qr/^Constant name 'STDERR' is forced into package main:: at/,
200   qr/^Constant name 'ARGV' is forced into package main:: at/,
201   qr/^Constant name 'ARGVOUT' is forced into package main:: at/,
202   qr/^Constant name 'ENV' is forced into package main:: at/,
203   qr/^Constant name 'INC' is forced into package main:: at/,
204   qr/^Constant name 'SIG' is forced into package main:: at/,
205   qr/^Constant name 'UNITCHECK' is a Perl keyword at/,
206);
207
208unless ($] > 5.009) {
209    # Remove the UNITCHECK warning
210    pop @Expected_Warnings;
211    # But keep the count the same
212    push @Expected_Warnings, qr/^$/;
213    push @warnings, "";
214}
215
216# when run under "make test"
217if (@warnings == 16) {
218    push @warnings, "";
219    push @Expected_Warnings, qr/^$/;
220}
221# when run directly: perl -wT -Ilib t/constant.t
222elsif (@warnings == 17) {
223    splice @Expected_Warnings, 1, 0,
224        qr/^Prototype mismatch: sub main::BEGIN \(\) vs none at/;
225}
226# when run directly under 5.6.2: perl -wT -Ilib t/constant.t
227elsif (@warnings == 15) {
228    splice @Expected_Warnings, 1, 1;
229    push @warnings, "", "";
230    push @Expected_Warnings, qr/^$/, qr/^$/;
231}
232else {
233    my $rule = " -" x 20;
234    diag "/!\\ unexpected case: ", scalar @warnings, " warnings\n$rule\n";
235    diag map { "  $_" } @warnings;
236    diag $rule, $/;
237}
238
239is @warnings, 17;
240
241for my $idx (0..$#warnings) {
242    like $warnings[$idx], $Expected_Warnings[$idx];
243}
244
245@warnings = ();
246
247
248use constant {
249	THREE  => 3,
250	FAMILY => [ qw( John Jane Sally ) ],
251	AGES   => { John => 33, Jane => 28, Sally => 3 },
252	RFAM   => [ [ qw( John Jane Sally ) ] ],
253	SPIT   => sub { shift },
254};
255
256is @{+FAMILY}, THREE;
257is @{+FAMILY}, @{RFAM->[0]};
258is FAMILY->[2], RFAM->[0]->[2];
259is AGES->{FAMILY->[1]}, 28;
260is THREE**3, SPIT->(@{+FAMILY}**3);
261
262# Allow name of digits/underscores only if it begins with underscore
263{
264    use warnings FATAL => 'constant';
265    eval q{
266        use constant _1_2_3 => 'allowed';
267    };
268    ok( $@ eq '' );
269}
270
271sub slotch ();
272
273{
274    my @warnings;
275    local $SIG{'__WARN__'} = sub { push @warnings, @_ };
276    eval 'use constant slotch => 3; 1' or die $@;
277
278    is ("@warnings", "", "No warnings if a prototype exists");
279
280    my $value = eval 'slotch';
281    is ($@, '');
282    is ($value, 3);
283}
284
285sub zit;
286
287{
288    my @warnings;
289    local $SIG{'__WARN__'} = sub { push @warnings, @_ };
290    eval 'use constant zit => 4; 1' or die $@;
291
292    # empty prototypes are reported differently in different versions
293    my $no_proto = $] < 5.008004 ? "" : ": none";
294
295    is(scalar @warnings, 1, "1 warning");
296    like ($warnings[0], qr/^Prototype mismatch: sub main::zit$no_proto vs \(\)/,
297	  "about the prototype mismatch");
298
299    my $value = eval 'zit';
300    is ($@, '');
301    is ($value, 4);
302}
303
304$fagwoosh = 'geronimo';
305$putt = 'leutwein';
306$kloong = 'schlozhauer';
307
308{
309    my @warnings;
310    local $SIG{'__WARN__'} = sub { push @warnings, @_ };
311    eval 'use constant fagwoosh => 5; 1' or die $@;
312
313    is ("@warnings", "", "No warnings if the typeglob exists already");
314
315    my $value = eval 'fagwoosh';
316    is ($@, '');
317    is ($value, 5);
318
319    my @value = eval 'fagwoosh';
320    is ($@, '');
321    is_deeply (\@value, [5]);
322
323    eval 'use constant putt => 6, 7; 1' or die $@;
324
325    is ("@warnings", "", "No warnings if the typeglob exists already");
326
327    @value = eval 'putt';
328    is ($@, '');
329    is_deeply (\@value, [6, 7]);
330
331    eval 'use constant "klong"; 1' or die $@;
332
333    is ("@warnings", "", "No warnings if the typeglob exists already");
334
335    $value = eval 'klong';
336    is ($@, '');
337    is ($value, undef);
338
339    @value = eval 'klong';
340    is ($@, '');
341    is_deeply (\@value, []);
342}
343
344{
345    local $SIG{'__WARN__'} = sub { die "WARNING: $_[0]" };
346    eval 'use constant undef, 5; 1';
347    like $@, qr/\ACan't use undef as constant name at /;
348}
349
350# Constants created by "use constant" should be read-only
351
352# This test will not test what we are trying to test if this glob entry
353# exists already, so test that, too.
354ok !exists $::{immutable};
355eval q{
356    use constant immutable => 23987423874;
357    for (immutable) { eval { $_ = 22 } }
358    like $@, qr/^Modification of a read-only value attempted at /,
359	'constant created in empty stash slot is immutable';
360    eval { for (immutable) { ${\$_} = 432 } };
361    SKIP: {
362	require Config;
363	if ($Config::Config{useithreads}) {
364	    skip "fails under threads", 1 if $] < 5.019003;
365	}
366	like $@, qr/^Modification of a read-only value attempted at /,
367	    '... and immutable through refgen, too';
368    }
369};
370() = \&{"immutable"}; # reify
371eval 'for (immutable) { $_ = 42 }';
372like $@, qr/^Modification of a read-only value attempted at /,
373    '... and after reification';
374
375# Use an existing stash element this time.
376# This next line is sufficient to trigger a different code path in
377# constant.pm.
378() = \%::existing_stash_entry;
379use constant existing_stash_entry => 23987423874;
380for (existing_stash_entry) { eval { $_ = 22 } }
381like $@, qr/^Modification of a read-only value attempted at /,
382    'constant created in existing stash slot is immutable';
383eval { for (existing_stash_entry) { ${\$_} = 432 } };
384SKIP: {
385    if ($Config::Config{useithreads}) {
386	skip "fails under threads", 1 if $] < 5.019003;
387    }
388    like $@, qr/^Modification of a read-only value attempted at /,
389	'... and immutable through refgen, too';
390}
391
392# Test that list constants are also immutable.  This only works under
393# 5.19.3 and later.
394SKIP: {
395    skip "fails under 5.19.2 and earlier", 3 if $] < 5.019003;
396    local $TODO = "disabled for now; breaks CPAN; see perl #119045";
397    use constant constant_list => 1..2;
398    for (constant_list) {
399	my $num = $_;
400	eval { $_++ };
401	like $@, qr/^Modification of a read-only value attempted at /,
402	    "list constant has constant elements ($num)";
403    }
404    undef $TODO;
405    # Whether values are modifiable or no, modifying them should not affect
406    # future return values.
407    my @values;
408    for(1..2) {
409	for ((constant_list)[0]) {
410	    push @values, $_;
411	    eval {$_++};
412	}
413    }
414    is $values[1], $values[0],
415	'modifying list const elements does not affect future retavls';
416}
417