1 | package Devel::FindRef; |
1 | package Devel::FindRef; |
2 | |
2 | |
3 | use strict; |
3 | use common::sense; |
4 | |
4 | |
5 | use XSLoader; |
5 | use XSLoader; |
6 | use Scalar::Util; |
6 | use Scalar::Util; |
7 | |
7 | |
8 | BEGIN { |
8 | BEGIN { |
9 | our $VERSION = '1.3'; |
9 | our $VERSION = '1.422'; |
10 | XSLoader::load __PACKAGE__, $VERSION; |
10 | XSLoader::load __PACKAGE__, $VERSION; |
11 | } |
11 | } |
12 | |
12 | |
13 | =head1 NAME |
13 | =head1 NAME |
14 | |
14 | |
15 | Devel::FindRef - where is that reference to my variable hiding? |
15 | Devel::FindRef - where is that reference to my variable hiding? |
16 | |
16 | |
17 | =head1 SYNOPSIS |
17 | =head1 SYNOPSIS |
18 | |
18 | |
19 | use Devel::FindRef; |
19 | use Devel::FindRef; |
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20 | |
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21 | print Devel::FindRef::track \$some_variable; |
20 | |
22 | |
21 | =head1 DESCRIPTION |
23 | =head1 DESCRIPTION |
22 | |
24 | |
23 | Tracking down reference problems (e.g. you expect some object to be |
25 | Tracking down reference problems (e.g. you expect some object to be |
24 | destroyed, but there are still references to it that keep it alive) can be |
26 | destroyed, but there are still references to it that keep it alive) can be |
… | |
… | |
29 | the variables containing them. |
31 | the variables containing them. |
30 | |
32 | |
31 | For example, for this fragment: |
33 | For example, for this fragment: |
32 | |
34 | |
33 | package Test; |
35 | package Test; |
|
|
36 | |
|
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37 | use Devel::FindRef; |
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38 | use Scalar::Util; |
34 | |
39 | |
35 | our $var = "hi\n"; |
40 | our $var = "hi\n"; |
36 | my $x = \$var; |
41 | my $global_my = \$var; |
37 | our %hash = (ukukey => \$var); |
42 | our %global_hash = (ukukey => \$var); |
38 | our $hash2 = {ukukey2 => \$var}; |
43 | our $global_hashref = { ukukey2 => \$var }; |
39 | |
44 | |
40 | sub testsub { |
45 | sub testsub { |
41 | my $local = $hash2; |
46 | my $testsub_local = $global_hashref; |
42 | print Devel::FindRef::track \$var; |
47 | print Devel::FindRef::track \$var; |
43 | } |
48 | } |
44 | |
49 | |
45 | testsub; |
50 | |
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51 | my $closure = sub { |
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52 | my $closure_var = \$_[0]; |
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53 | Scalar::Util::weaken (my $weak_ref = \$var); |
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54 | testsub; |
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55 | }; |
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56 | |
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57 | $closure->($var); |
46 | |
58 | |
47 | The output is as follows (or similar to this, in case I forget to update |
59 | The output is as follows (or similar to this, in case I forget to update |
48 | the manpage after some changes): |
60 | the manpage after some changes): |
49 | |
61 | |
50 | SCALAR(0x814ece8) is |
62 | SCALAR(0x7cc888) [refcount 6] is |
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63 | +- referenced by REF(0x8abcc8) [refcount 1], which is |
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64 | | the lexical '$closure_var' in CODE(0x8abc50) [refcount 4], which is |
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65 | | +- the closure created at tst:18. |
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66 | | +- referenced by REF(0x7d3c58) [refcount 1], which is |
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67 | | | the lexical '$closure' in CODE(0x7ae530) [refcount 2], which is |
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68 | | | +- the containing scope for CODE(0x8ab430) [refcount 3], which is |
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69 | | | | the global &Test::testsub. |
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70 | | | +- the main body of the program. |
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71 | | +- the lexical '&' in CODE(0x7ae530) [refcount 2], which was seen before. |
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72 | +- referenced by REF(0x7cc7c8) [refcount 1], which is |
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73 | | the lexical '$global_my' in CODE(0x7ae530) [refcount 2], which was seen before. |
51 | +- in the global $Test::var. |
74 | +- the global $Test::var. |
52 | +- referenced by REF(0x814f9e4), which is |
75 | +- referenced by REF(0x7cc558) [refcount 1], which is |
53 | | in the lexical '$x' in CODE(0x814ed78), which is |
76 | | the member 'ukukey2' of HASH(0x7ae140) [refcount 2], which is |
54 | | the containing scope for CODE(0x820c4b0), which is |
77 | | +- referenced by REF(0x8abad0) [refcount 1], which is |
55 | | in the global &Test::testsub. |
78 | | | the lexical '$testsub_local' in CODE(0x8ab430) [refcount 3], which was seen before. |
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79 | | +- referenced by REF(0x8ab4f0) [refcount 1], which is |
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80 | | the global $Test::global_hashref. |
56 | +- referenced by REF(0x814ed6c), which is |
81 | +- referenced by REF(0x7ae518) [refcount 1], which is |
57 | | in the member 'ukukey' of HASH(0x81da20c), which is |
82 | | the member 'ukukey' of HASH(0x7d3bb0) [refcount 1], which is |
58 | | in the global %Test::hash. |
83 | | the global %Test::global_hash. |
59 | +- referenced by REF(0x814ec28), which is |
84 | +- referenced by REF(0x7ae2f0) [refcount 1], which is |
60 | | not found anywhere I looked :( |
85 | a temporary on the stack. |
61 | +- referenced by REF(0x814eb44), which is |
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62 | in the member 'ukukey2' of HASH(0x814f99c), which is |
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63 | +- referenced by REF(0x820c450), which is |
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64 | | in the lexical '$local' in CODE(0x820c4b0), which was seen before. |
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65 | +- referenced by REF(0x820c204), which is |
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66 | in the global $Test::hash2. |
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67 | |
86 | |
68 | It is a bit convoluted to read, but basically it says that the value |
87 | It is a bit convoluted to read, but basically it says that the value |
69 | stored in C<$var> can be found: |
88 | stored in C<$var> is referenced by: |
70 | |
89 | |
71 | =over 4 |
90 | =over 4 |
72 | |
91 | |
73 | =item - in some variable C<$x> whose origin is not known (I frankly have no |
92 | =item - the lexical C<$closure_var> (0x8abcc8), which is inside an instantiated |
74 | idea why, hints accepted). |
93 | closure, which in turn is used quite a bit. |
75 | |
94 | |
76 | =item - in the hash element with key C<ukukey> in the hash stored in C<%Test::hash>. |
95 | =item - the package-level lexical C<$global_my>. |
77 | |
96 | |
78 | =item - in the global variable named C<$Test::var>. |
97 | =item - the global package variable named C<$Test::var>. |
79 | |
98 | |
80 | =item - in the hash element C<ukukey2>, in the hash in the my variable |
99 | =item - the hash element C<ukukey2>, in the hash in the my variable |
81 | C<$local> in the sub C<Test::testsub> and also in the hash referenced by |
100 | C<$testsub_local> in the sub C<Test::testsub> and also in the hash |
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101 | C<$referenced by Test::hash2>. |
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102 | |
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103 | =item - the hash element with key C<ukukey> in the hash stored in |
82 | C<$Test::hash2>. |
104 | C<%Test::hash>. |
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105 | |
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106 | =item - some anonymous mortalised reference on the stack (which is caused |
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107 | by calling C<track> with the expression C<\$var>, which creates the |
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108 | reference). |
83 | |
109 | |
84 | =back |
110 | =back |
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111 | |
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112 | And all these account for six reference counts. |
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113 | |
85 | |
114 | |
86 | =head1 EXPORTS |
115 | =head1 EXPORTS |
87 | |
116 | |
88 | None. |
117 | None. |
89 | |
118 | |
… | |
… | |
100 | This is the function you most often use. |
129 | This is the function you most often use. |
101 | |
130 | |
102 | =cut |
131 | =cut |
103 | |
132 | |
104 | sub find($); |
133 | sub find($); |
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134 | |
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135 | sub _f($) { |
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136 | "$_[0] [refcount " . (_refcnt $_[0]) . "]" |
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137 | } |
105 | |
138 | |
106 | sub track { |
139 | sub track { |
107 | my ($ref, $depth) = @_; |
140 | my ($ref, $depth) = @_; |
108 | @_ = (); |
141 | @_ = (); |
109 | |
142 | |
… | |
… | |
117 | |
150 | |
118 | if ($depth) { |
151 | if ($depth) { |
119 | my (@about) = find $$refref; |
152 | my (@about) = find $$refref; |
120 | if (@about) { |
153 | if (@about) { |
121 | for my $about (@about) { |
154 | for my $about (@about) { |
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155 | $about->[0] =~ s/([^\x20-\x7e])/sprintf "\\{%02x}", ord $1/ge; |
122 | $buf .= "$indent" . (@about > 1 ? "+- " : " ") . $about->[0]; |
156 | $buf .= "$indent" . (@about > 1 ? "+- " : "") . $about->[0]; |
123 | if (@$about > 1) { |
157 | if (@$about > 1) { |
124 | if ($seen{ref2ptr $about->[1]}++) { |
158 | if ($seen{ref2ptr $about->[1]}++) { |
125 | $buf .= " $about->[1], which was seen before.\n"; |
159 | $buf .= " " . (_f $about->[1]) . ", which was seen before.\n"; |
126 | } else { |
160 | } else { |
127 | $buf .= " $about->[1], which is\n"; |
161 | $buf .= " " . (_f $about->[1]) . ", which is\n"; |
128 | $track->(\$about->[1], $depth - 1, $about == $about[-1] ? "$indent " : "$indent| "); |
162 | $track->(\$about->[1], $depth - 1, $about == $about[-1] ? "$indent " : "$indent| "); |
129 | } |
163 | } |
130 | } else { |
164 | } else { |
131 | $buf .= ".\n"; |
165 | $buf .= ".\n"; |
132 | } |
166 | } |
… | |
… | |
137 | } else { |
171 | } else { |
138 | $buf .= "$indent not referenced within the search depth.\n"; |
172 | $buf .= "$indent not referenced within the search depth.\n"; |
139 | } |
173 | } |
140 | }; |
174 | }; |
141 | |
175 | |
142 | $buf .= "$ref is\n"; |
176 | $buf .= (_f $ref) . " is\n"; |
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177 | |
143 | $track->(\$ref, $depth || $ENV{PERL_DEVEL_FINDREF_DEPTH} || 10, ""); |
178 | $track->(\$ref, $depth || $ENV{PERL_DEVEL_FINDREF_DEPTH} || 10, ""); |
144 | $buf |
179 | $buf |
145 | } |
180 | } |
146 | |
181 | |
147 | =item @references = Devel::FindRef::find $ref |
182 | =item @references = Devel::FindRef::find $ref |
… | |
… | |
157 | =cut |
192 | =cut |
158 | |
193 | |
159 | sub find($) { |
194 | sub find($) { |
160 | my ($about, $excl) = &find_; |
195 | my ($about, $excl) = &find_; |
161 | my %excl = map +($_ => undef), @$excl; |
196 | my %excl = map +($_ => undef), @$excl; |
162 | grep !exists $excl{ref2ptr $_->[1]}, @$about |
197 | grep !($#$_ && exists $excl{ref2ptr $_->[1]}), @$about |
163 | } |
198 | } |
164 | |
199 | |
165 | =item $ref = Devel::FindRef::ptr2ref $integer |
200 | =item $ref = Devel::FindRef::ptr2ref $integer |
166 | |
201 | |
167 | Sometimes you know (from debugging output) the address of a perl scalar |
202 | Sometimes you know (from debugging output) the address of a perl scalar |
… | |
… | |
170 | call on valid addresses, but extremely dangerous to call on invalid ones. |
205 | call on valid addresses, but extremely dangerous to call on invalid ones. |
171 | |
206 | |
172 | # we know that HASH(0x176ff70) exists, so turn it into a hashref: |
207 | # we know that HASH(0x176ff70) exists, so turn it into a hashref: |
173 | my $ref_to_hash = Devel::FindRef::ptr2ref 0x176ff70; |
208 | my $ref_to_hash = Devel::FindRef::ptr2ref 0x176ff70; |
174 | |
209 | |
175 | =item $ref = Devel::FindRef::ref2ptr $reference |
210 | =item $ptr = Devel::FindRef::ref2ptr $reference |
176 | |
211 | |
177 | The opposite of C<ptr2ref>, above: returns the internal address of the |
212 | The opposite of C<ptr2ref>, above: returns the internal address of the |
178 | value pointed to by the passed reference. I<No checks whatsoever will be |
213 | value pointed to by the passed reference. I<No checks whatsoever will be |
179 | done>, so don't use this. |
214 | done>, so don't use this. |
180 | |
215 | |
… | |
… | |
188 | |
223 | |
189 | =head1 AUTHOR |
224 | =head1 AUTHOR |
190 | |
225 | |
191 | Marc Lehmann <pcg@goof.com>. |
226 | Marc Lehmann <pcg@goof.com>. |
192 | |
227 | |
193 | =head1 BUGS |
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194 | |
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195 | Only code values, arrays, hashes, scalars and magic are being looked at. |
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196 | |
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197 | This is a quick hack only. |
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198 | |
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199 | =head1 COPYRIGHT AND LICENSE |
228 | =head1 COPYRIGHT AND LICENSE |
200 | |
229 | |
201 | Copyright (C) 2007 by Marc Lehmann. |
230 | Copyright (C) 2007, 2008 by Marc Lehmann. |
202 | |
231 | |
203 | This library is free software; you can redistribute it and/or modify |
232 | This library is free software; you can redistribute it and/or modify |
204 | it under the same terms as Perl itself, either Perl version 5.8.8 or, |
233 | it under the same terms as Perl itself, either Perl version 5.8.8 or, |
205 | at your option, any later version of Perl 5 you may have available. |
234 | at your option, any later version of Perl 5 you may have available. |
206 | |
235 | |