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Comparing Devel-FindRef/FindRef.pm (file contents):
Revision 1.8 by root, Wed Nov 28 12:20:33 2007 UTC vs.
Revision 1.16 by root, Fri Sep 19 05:07:56 2008 UTC

1package Devel::FindRef; 1package Devel::FindRef;
2 2
3no warnings; # I hate warning nazis
3use strict; 4use strict;
4 5
5use XSLoader; 6use XSLoader;
7use Scalar::Util;
6 8
7BEGIN { 9BEGIN {
8 our $VERSION = '1.0'; 10 our $VERSION = '1.31';
9 XSLoader::load __PACKAGE__, $VERSION; 11 XSLoader::load __PACKAGE__, $VERSION;
10} 12}
11 13
12=head1 NAME 14=head1 NAME
13 15
14Devel::FindRef - where is that reference to my scalar hiding? 16Devel::FindRef - where is that reference to my variable hiding?
15 17
16=head1 SYNOPSIS 18=head1 SYNOPSIS
17 19
18 use Devel::FindRef; 20 use Devel::FindRef;
21
22 print Devel::FindRef::track \$some_variable;
19 23
20=head1 DESCRIPTION 24=head1 DESCRIPTION
21 25
22Tracking down reference problems (e.g. you expect some object to be 26Tracking down reference problems (e.g. you expect some object to be
23destroyed, but there are still references to it that keep it alive) can be 27destroyed, but there are still references to it that keep it alive) can be
… …
44 testsub; 48 testsub;
45 49
46The output is as follows (or similar to this, in case I forget to update 50The output is as follows (or similar to this, in case I forget to update
47the manpage after some changes): 51the manpage after some changes):
48 52
49 SCALAR(0x676fa0) is 53 SCALAR(0x814ece8) is
54 +- in the global $Test::var.
50 referenced by REF(0x676fb0), which is 55 +- referenced by REF(0x814f9e4), which is
51 in the lexical '$x' in CODE(0x676370), which is 56 | in the lexical '$x' in CODE(0x814ed78), which is
52 not found anywhere I looked :( 57 | the containing scope for CODE(0x820c4b0), which is
58 | in the global &Test::testsub.
53 referenced by REF(0x676360), which is 59 +- referenced by REF(0x814ed6c), which is
54 in the member 'ukukey' of HASH(0x756660), which is 60 | in the member 'ukukey' of HASH(0x81da20c), which is
55 in the global %Test::hash. 61 | in the global %Test::hash.
56 in the global $Test::var.
57 referenced by REF(0x6760e0), which is 62 +- referenced by REF(0x814ec28), which is
63 | not found anywhere I looked :(
64 +- referenced by REF(0x814eb44), which is
58 in the member 'ukukey2' of HASH(0x676f30), which is 65 in the member 'ukukey2' of HASH(0x814f99c), which is
59 referenced by REF(0x77bcf0), which is 66 +- referenced by REF(0x820c450), which is
60 in the lexical '$local' in CODE(0x77bcb0), which is 67 | in the lexical '$local' in CODE(0x820c4b0), which was seen before.
61 in the global &Test::testsub.
62 referenced by REF(0x77bc80), which is 68 +- referenced by REF(0x820c204), which is
63 in the global $Test::hash2. 69 in the global $Test::hash2.
64
65 70
66It is a bit convoluted to read, but basically it says that the value 71It is a bit convoluted to read, but basically it says that the value
67stored in C<$var> can be found: 72stored in C<$var> can be found:
68 73
69=over 4 74=over 4
… …
100=cut 105=cut
101 106
102sub find($); 107sub find($);
103 108
104sub track { 109sub track {
110 my ($ref, $depth) = @_;
111 @_ = ();
112
105 my $buf = ""; 113 my $buf = "";
106 my %ignore; 114 my %seen;
115
116 Scalar::Util::weaken $ref;
107 117
108 my $track; $track = sub { 118 my $track; $track = sub {
109 my ($target, $depth, $indent) = @_; 119 my ($refref, $depth, $indent) = @_;
110 @_ = ();
111 local $ignore{$target+0} = undef;
112 120
113 if ($depth) { 121 if ($depth) {
114 my (@about) = grep !exists $ignore{$_->[1]}, find $target; 122 my (@about) = find $$refref;
115 if (@about) { 123 if (@about) {
116 local @ignore{map $_->[1]+0, @about} = ();
117 for my $about (@about) { 124 for my $about (@about) {
118 local $ignore{$about+0} = undef; 125 $buf .= "$indent" . (@about > 1 ? "+- " : " ") . $about->[0];
119 $buf .= (" ") x $indent;
120 $buf .= $about->[0];
121 if (@$about > 1) { 126 if (@$about > 1) {
127 if ($seen{ref2ptr $about->[1]}++) {
128 $buf .= " $about->[1], which was seen before.\n";
129 } else {
122 $buf .= " $about->[1], which is\n"; 130 $buf .= " $about->[1], which is\n";
123 $track->($about->[1], $depth - 1, $indent + 1); 131 $track->(\$about->[1], $depth - 1, $about == $about[-1] ? "$indent " : "$indent| ");
132 }
124 } else { 133 } else {
125 $buf .= ".\n"; 134 $buf .= ".\n";
126 } 135 }
127 } 136 }
128 } else { 137 } else {
129 $buf .= (" ") x $indent;
130 $buf .= "not found anywhere I looked :(\n"; 138 $buf .= "$indent not found anywhere I looked :(\n";
131 } 139 }
132 } else { 140 } else {
133 $buf .= (" ") x $indent;
134 $buf .= "not referenced within the search depth.\n"; 141 $buf .= "$indent not referenced within the search depth.\n";
135 } 142 }
136 }; 143 };
137 144
138 $buf .= "$_[0] is\n"; 145 $buf .= "$ref is\n";
139 $track->($_[0], $_[1] || 10, 1); 146 $track->(\$ref, $depth || $ENV{PERL_DEVEL_FINDREF_DEPTH} || 10, "");
140 $buf 147 $buf
141} 148}
142 149
143=item @references = Devel::FindRef::find $ref 150=item @references = Devel::FindRef::find $ref
144 151
145Return arrayrefs that contain [$message, $ref] pairs. The message 152Return arrayrefs that contain [$message, $ref] pairs. The message
146describes what kind of reference was found and the C<$ref> is the 153describes what kind of reference was found and the C<$ref> is the
147reference itself, which cna be omitted if C<find> decided to end the 154reference itself, which can be omitted if C<find> decided to end the
148search. 155search. The returned references are all weak references.
149 156
150The C<track> function uses this to find references to the value you are 157The C<track> function uses this to find references to the value you are
151interested in and recurses on the returned references. 158interested in and recurses on the returned references.
152 159
153=cut 160=cut
154 161
155sub find($) { 162sub find($) {
156 my ($about, $excl) = &find_; 163 my ($about, $excl) = &find_;
157 my %excl = map +($_ => undef), @$excl; 164 my %excl = map +($_ => undef), @$excl;
158 grep !exists $excl{$_->[1] + 0}, @$about 165 grep !exists $excl{ref2ptr $_->[1]}, @$about
159} 166}
160 167
161=item $ref = Devel::FindRef::ptr2ref $integer 168=item $ref = Devel::FindRef::ptr2ref $integer
162 169
163Sometimes you know (from debugging output) the address of a perl scalar 170Sometimes you know (from debugging output) the address of a perl scalar
… …
166call on valid addresses, but extremely dangerous to call on invalid ones. 173call on valid addresses, but extremely dangerous to call on invalid ones.
167 174
168 # we know that HASH(0x176ff70) exists, so turn it into a hashref: 175 # we know that HASH(0x176ff70) exists, so turn it into a hashref:
169 my $ref_to_hash = Devel::FindRef::ptr2ref 0x176ff70; 176 my $ref_to_hash = Devel::FindRef::ptr2ref 0x176ff70;
170 177
178=item $ref = Devel::FindRef::ref2ptr $reference
179
180The opposite of C<ptr2ref>, above: returns the internal address of the
181value pointed to by the passed reference. I<No checks whatsoever will be
182done>, so don't use this.
183
171=back 184=back
185
186=head1 ENVIRONMENT VARIABLES
187
188You can set the environment variable C<PERL_DEVEL_FINDREF_DEPTH> to an
189integer to override the default depth in C<track>. If a call explicitly
190specified a depth it is not overridden.
172 191
173=head1 AUTHOR 192=head1 AUTHOR
174 193
175Marc Lehmann <pcg@goof.com>. 194Marc Lehmann <pcg@goof.com>.
176 195

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