1package Exporter::Heavy; 2 3use strict; 4no strict 'refs'; 5 6# On one line so MakeMaker will see it. 7require Exporter; our $VERSION = $Exporter::VERSION; 8$Carp::Internal{"Exporter::Heavy"} = 1; 9 10=head1 NAME 11 12Exporter::Heavy - Exporter guts 13 14=head1 SYNOPSIS 15 16(internal use only) 17 18=head1 DESCRIPTION 19 20No user-serviceable parts inside. 21 22=cut 23 24# 25# We go to a lot of trouble not to 'require Carp' at file scope, 26# because Carp requires Exporter, and something has to give. 27# 28 29sub _rebuild_cache { 30 my ($pkg, $exports, $cache) = @_; 31 s/^&// foreach @$exports; 32 @{$cache}{@$exports} = (1) x @$exports; 33 my $ok = \@{"${pkg}::EXPORT_OK"}; 34 if (@$ok) { 35 s/^&// foreach @$ok; 36 @{$cache}{@$ok} = (1) x @$ok; 37 } 38} 39 40sub heavy_export { 41 42 # First make import warnings look like they're coming from the "use". 43 local $SIG{__WARN__} = sub { 44 my $text = shift; 45 if ($text =~ s/ at \S*Exporter\S*.pm line \d+.*\n//) { 46 require Carp; 47 local $Carp::CarpLevel = 1; # ignore package calling us too. 48 Carp::carp($text); 49 } 50 else { 51 warn $text; 52 } 53 }; 54 local $SIG{__DIE__} = sub { 55 require Carp; 56 local $Carp::CarpLevel = 1; # ignore package calling us too. 57 Carp::croak("$_[0]Illegal null symbol in \@${1}::EXPORT") 58 if $_[0] =~ /^Unable to create sub named "(.*?)::"/; 59 }; 60 61 my($pkg, $callpkg, @imports) = @_; 62 my($type, $sym, $cache_is_current, $oops); 63 my($exports, $export_cache) = (\@{"${pkg}::EXPORT"}, 64 $Exporter::Cache{$pkg} ||= {}); 65 66 if (@imports) { 67 if (!%$export_cache) { 68 _rebuild_cache ($pkg, $exports, $export_cache); 69 $cache_is_current = 1; 70 } 71 72 if (grep m{^[/!:]}, @imports) { 73 my $tagsref = \%{"${pkg}::EXPORT_TAGS"}; 74 my $tagdata; 75 my %imports; 76 my($remove, $spec, @names, @allexports); 77 # negated first item implies starting with default set: 78 unshift @imports, ':DEFAULT' if $imports[0] =~ m/^!/; 79 foreach $spec (@imports){ 80 $remove = $spec =~ s/^!//; 81 82 if ($spec =~ s/^://){ 83 if ($spec eq 'DEFAULT'){ 84 @names = @$exports; 85 } 86 elsif ($tagdata = $tagsref->{$spec}) { 87 @names = @$tagdata; 88 } 89 else { 90 warn qq["$spec" is not defined in %${pkg}::EXPORT_TAGS]; 91 ++$oops; 92 next; 93 } 94 } 95 elsif ($spec =~ m:^/(.*)/$:){ 96 my $patn = $1; 97 @allexports = keys %$export_cache unless @allexports; # only do keys once 98 @names = grep(/$patn/, @allexports); # not anchored by default 99 } 100 else { 101 @names = ($spec); # is a normal symbol name 102 } 103 104 warn "Import ".($remove ? "del":"add").": @names " 105 if $Exporter::Verbose; 106 107 if ($remove) { 108 foreach $sym (@names) { delete $imports{$sym} } 109 } 110 else { 111 @imports{@names} = (1) x @names; 112 } 113 } 114 @imports = keys %imports; 115 } 116 117 my @carp; 118 foreach $sym (@imports) { 119 if (!$export_cache->{$sym}) { 120 if ($sym =~ m/^\d/) { 121 $pkg->VERSION($sym); # inherit from UNIVERSAL 122 # If the version number was the only thing specified 123 # then we should act as if nothing was specified: 124 if (@imports == 1) { 125 @imports = @$exports; 126 last; 127 } 128 # We need a way to emulate 'use Foo ()' but still 129 # allow an easy version check: "use Foo 1.23, ''"; 130 if (@imports == 2 and !$imports[1]) { 131 @imports = (); 132 last; 133 } 134 } elsif ($sym !~ s/^&// || !$export_cache->{$sym}) { 135 # Last chance - see if they've updated EXPORT_OK since we 136 # cached it. 137 138 unless ($cache_is_current) { 139 %$export_cache = (); 140 _rebuild_cache ($pkg, $exports, $export_cache); 141 $cache_is_current = 1; 142 } 143 144 if (!$export_cache->{$sym}) { 145 # accumulate the non-exports 146 push @carp, 147 qq["$sym" is not exported by the $pkg module\n]; 148 $oops++; 149 } 150 } 151 } 152 } 153 if ($oops) { 154 require Carp; 155 Carp::croak("@{carp}Can't continue after import errors"); 156 } 157 } 158 else { 159 @imports = @$exports; 160 } 161 162 my($fail, $fail_cache) = (\@{"${pkg}::EXPORT_FAIL"}, 163 $Exporter::FailCache{$pkg} ||= {}); 164 165 if (@$fail) { 166 if (!%$fail_cache) { 167 # Build cache of symbols. Optimise the lookup by adding 168 # barewords twice... both with and without a leading &. 169 # (Technique could be applied to $export_cache at cost of memory) 170 my @expanded = map { /^\w/ ? ($_, '&'.$_) : $_ } @$fail; 171 warn "${pkg}::EXPORT_FAIL cached: @expanded" if $Exporter::Verbose; 172 @{$fail_cache}{@expanded} = (1) x @expanded; 173 } 174 my @failed; 175 foreach $sym (@imports) { push(@failed, $sym) if $fail_cache->{$sym} } 176 if (@failed) { 177 @failed = $pkg->export_fail(@failed); 178 foreach $sym (@failed) { 179 require Carp; 180 Carp::carp(qq["$sym" is not implemented by the $pkg module ], 181 "on this architecture"); 182 } 183 if (@failed) { 184 require Carp; 185 Carp::croak("Can't continue after import errors"); 186 } 187 } 188 } 189 190 warn "Importing into $callpkg from $pkg: ", 191 join(", ",sort @imports) if $Exporter::Verbose; 192 193 foreach $sym (@imports) { 194 # shortcut for the common case of no type character 195 (*{"${callpkg}::$sym"} = \&{"${pkg}::$sym"}, next) 196 unless $sym =~ s/^(\W)//; 197 $type = $1; 198 *{"${callpkg}::$sym"} = 199 $type eq '&' ? \&{"${pkg}::$sym"} : 200 $type eq '$' ? \${"${pkg}::$sym"} : 201 $type eq '@' ? \@{"${pkg}::$sym"} : 202 $type eq '%' ? \%{"${pkg}::$sym"} : 203 $type eq '*' ? *{"${pkg}::$sym"} : 204 do { require Carp; Carp::croak("Can't export symbol: $type$sym") }; 205 } 206} 207 208sub heavy_export_to_level 209{ 210 my $pkg = shift; 211 my $level = shift; 212 (undef) = shift; # XXX redundant arg 213 my $callpkg = caller($level); 214 $pkg->export($callpkg, @_); 215} 216 217# Utility functions 218 219sub _push_tags { 220 my($pkg, $var, $syms) = @_; 221 my @nontag = (); 222 my $export_tags = \%{"${pkg}::EXPORT_TAGS"}; 223 push(@{"${pkg}::$var"}, 224 map { $export_tags->{$_} ? @{$export_tags->{$_}} 225 : scalar(push(@nontag,$_),$_) } 226 (@$syms) ? @$syms : keys %$export_tags); 227 if (@nontag and $^W) { 228 # This may change to a die one day 229 require Carp; 230 Carp::carp(join(", ", @nontag)." are not tags of $pkg"); 231 } 232} 233 234sub heavy_require_version { 235 my($self, $wanted) = @_; 236 my $pkg = ref $self || $self; 237 return ${pkg}->VERSION($wanted); 238} 239 240sub heavy_export_tags { 241 _push_tags((caller)[0], "EXPORT", \@_); 242} 243 244sub heavy_export_ok_tags { 245 _push_tags((caller)[0], "EXPORT_OK", \@_); 246} 247 2481; 249