Commit | Line | Data |
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4af1b167 IZ |
1 | package Exporter; |
2 | ||
3 | # | |
4 | # We go to a lot of trouble not to 'require Carp' at file scope, | |
5 | # because Carp requires Exporter, and something has to give. | |
6 | # | |
7 | ||
8 | sub heavy_export { | |
9 | ||
10 | # First make import warnings look like they're coming from the "use". | |
11 | local $SIG{__WARN__} = sub { | |
12 | my $text = shift; | |
13 | if ($text =~ s/ at \S*Exporter\S*.pm line \d+.*\n//) { | |
14 | require Carp; | |
15 | local $Carp::CarpLevel = 1; # ignore package calling us too. | |
16 | Carp::carp($text); | |
17 | } | |
18 | else { | |
19 | warn $text; | |
20 | } | |
21 | }; | |
22 | local $SIG{__DIE__} = sub { | |
23 | require Carp; | |
24 | local $Carp::CarpLevel = 1; # ignore package calling us too. | |
25 | Carp::croak("$_[0]Illegal null symbol in \@${1}::EXPORT") | |
26 | if $_[0] =~ /^Unable to create sub named "(.*?)::"/; | |
27 | }; | |
28 | ||
29 | my($pkg, $callpkg, @imports) = @_; | |
30 | my($type, $sym, $oops); | |
31 | *exports = *{"${pkg}::EXPORT"}; | |
32 | ||
33 | if (@imports) { | |
34 | if (!%exports) { | |
35 | grep(s/^&//, @exports); | |
36 | @exports{@exports} = (1) x @exports; | |
37 | my $ok = \@{"${pkg}::EXPORT_OK"}; | |
38 | if (@$ok) { | |
39 | grep(s/^&//, @$ok); | |
40 | @exports{@$ok} = (1) x @$ok; | |
41 | } | |
42 | } | |
43 | ||
44 | if ($imports[0] =~ m#^[/!:]#){ | |
45 | my $tagsref = \%{"${pkg}::EXPORT_TAGS"}; | |
46 | my $tagdata; | |
47 | my %imports; | |
48 | my($remove, $spec, @names, @allexports); | |
49 | # negated first item implies starting with default set: | |
50 | unshift @imports, ':DEFAULT' if $imports[0] =~ m/^!/; | |
51 | foreach $spec (@imports){ | |
52 | $remove = $spec =~ s/^!//; | |
53 | ||
54 | if ($spec =~ s/^://){ | |
55 | if ($spec eq 'DEFAULT'){ | |
56 | @names = @exports; | |
57 | } | |
58 | elsif ($tagdata = $tagsref->{$spec}) { | |
59 | @names = @$tagdata; | |
60 | } | |
61 | else { | |
62 | warn qq["$spec" is not defined in %${pkg}::EXPORT_TAGS]; | |
63 | ++$oops; | |
64 | next; | |
65 | } | |
66 | } | |
67 | elsif ($spec =~ m:^/(.*)/$:){ | |
68 | my $patn = $1; | |
69 | @allexports = keys %exports unless @allexports; # only do keys once | |
70 | @names = grep(/$patn/, @allexports); # not anchored by default | |
71 | } | |
72 | else { | |
73 | @names = ($spec); # is a normal symbol name | |
74 | } | |
75 | ||
76 | warn "Import ".($remove ? "del":"add").": @names " | |
77 | if $Verbose; | |
78 | ||
79 | if ($remove) { | |
80 | foreach $sym (@names) { delete $imports{$sym} } | |
81 | } | |
82 | else { | |
83 | @imports{@names} = (1) x @names; | |
84 | } | |
85 | } | |
86 | @imports = keys %imports; | |
87 | } | |
88 | ||
89 | foreach $sym (@imports) { | |
90 | if (!$exports{$sym}) { | |
91 | if ($sym =~ m/^\d/) { | |
92 | $pkg->require_version($sym); | |
93 | # If the version number was the only thing specified | |
94 | # then we should act as if nothing was specified: | |
95 | if (@imports == 1) { | |
96 | @imports = @exports; | |
97 | last; | |
98 | } | |
99 | # We need a way to emulate 'use Foo ()' but still | |
100 | # allow an easy version check: "use Foo 1.23, ''"; | |
101 | if (@imports == 2 and !$imports[1]) { | |
102 | @imports = (); | |
103 | last; | |
104 | } | |
105 | } elsif ($sym !~ s/^&// || !$exports{$sym}) { | |
106 | require Carp; | |
107 | Carp::carp(qq["$sym" is not exported by the $pkg module]); | |
108 | $oops++; | |
109 | } | |
110 | } | |
111 | } | |
112 | if ($oops) { | |
113 | require Carp; | |
114 | Carp::croak("Can't continue after import errors"); | |
115 | } | |
116 | } | |
117 | else { | |
118 | @imports = @exports; | |
119 | } | |
120 | ||
121 | *fail = *{"${pkg}::EXPORT_FAIL"}; | |
122 | if (@fail) { | |
123 | if (!%fail) { | |
124 | # Build cache of symbols. Optimise the lookup by adding | |
125 | # barewords twice... both with and without a leading &. | |
126 | # (Technique could be applied to %exports cache at cost of memory) | |
127 | my @expanded = map { /^\w/ ? ($_, '&'.$_) : $_ } @fail; | |
128 | warn "${pkg}::EXPORT_FAIL cached: @expanded" if $Verbose; | |
129 | @fail{@expanded} = (1) x @expanded; | |
130 | } | |
131 | my @failed; | |
132 | foreach $sym (@imports) { push(@failed, $sym) if $fail{$sym} } | |
133 | if (@failed) { | |
134 | @failed = $pkg->export_fail(@failed); | |
135 | foreach $sym (@failed) { | |
136 | require Carp; | |
137 | Carp::carp(qq["$sym" is not implemented by the $pkg module ], | |
138 | "on this architecture"); | |
139 | } | |
140 | if (@failed) { | |
141 | require Carp; | |
142 | Carp::croak("Can't continue after import errors"); | |
143 | } | |
144 | } | |
145 | } | |
146 | ||
147 | warn "Importing into $callpkg from $pkg: ", | |
148 | join(", ",sort @imports) if $Verbose; | |
149 | ||
150 | foreach $sym (@imports) { | |
151 | # shortcut for the common case of no type character | |
152 | (*{"${callpkg}::$sym"} = \&{"${pkg}::$sym"}, next) | |
153 | unless $sym =~ s/^(\W)//; | |
154 | $type = $1; | |
155 | *{"${callpkg}::$sym"} = | |
156 | $type eq '&' ? \&{"${pkg}::$sym"} : | |
157 | $type eq '$' ? \${"${pkg}::$sym"} : | |
158 | $type eq '@' ? \@{"${pkg}::$sym"} : | |
159 | $type eq '%' ? \%{"${pkg}::$sym"} : | |
160 | $type eq '*' ? *{"${pkg}::$sym"} : | |
161 | do { require Carp; Carp::croak("Can't export symbol: $type$sym") }; | |
162 | } | |
163 | } | |
164 | ||
165 | sub heavy_export_to_level | |
166 | { | |
167 | my $pkg = shift; | |
168 | my $level = shift; | |
169 | my $callpkg = caller($level); | |
170 | $pkg->export($callpkg, @_); | |
171 | } | |
172 | ||
173 | # Utility functions | |
174 | ||
175 | sub _push_tags { | |
176 | my($pkg, $var, $syms) = @_; | |
177 | my $nontag; | |
178 | *export_tags = \%{"${pkg}::EXPORT_TAGS"}; | |
179 | push(@{"${pkg}::$var"}, | |
180 | map { $export_tags{$_} ? @{$export_tags{$_}} : scalar(++$nontag,$_) } | |
181 | (@$syms) ? @$syms : keys %export_tags); | |
182 | if ($nontag and $^W) { | |
183 | # This may change to a die one day | |
184 | require Carp; | |
185 | Carp::carp("Some names are not tags"); | |
186 | } | |
187 | } | |
188 | ||
189 | # Default methods | |
190 | ||
191 | sub export_fail { | |
192 | my $self = shift; | |
193 | @_; | |
194 | } | |
195 | ||
196 | sub require_version { | |
197 | my($self, $wanted) = @_; | |
198 | my $pkg = ref $self || $self; | |
199 | my $version = ${"${pkg}::VERSION"}; | |
200 | if (!$version or $version < $wanted) { | |
201 | $version ||= "(undef)"; | |
202 | my $file = $INC{"$pkg.pm"}; | |
203 | $file &&= " ($file)"; | |
204 | require Carp; | |
205 | Carp::croak("$pkg $wanted required--this is only version $version$file") | |
206 | } | |
207 | $version; | |
208 | } | |
209 | ||
210 | 1; |