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Comparing Devel-FindRef/FindRef.pm (file contents):
Revision 1.17 by root, Wed Nov 19 07:36:40 2008 UTC vs.
Revision 1.32 by root, Tue Jun 3 18:40:50 2014 UTC

1package Devel::FindRef; 1package Devel::FindRef;
2 2
3no warnings; # I hate warning nazis 3use common::sense;
4use strict;
5 4
6use XSLoader; 5use XSLoader;
7use Scalar::Util; 6use Scalar::Util;
8 7
9BEGIN { 8BEGIN {
10 our $VERSION = '1.31'; 9 our $VERSION = 1.44;
11 XSLoader::load __PACKAGE__, $VERSION; 10 XSLoader::load __PACKAGE__, $VERSION;
12} 11}
13 12
14=head1 NAME 13=head1 NAME
15 14
… …
31The C<track> function can help track down some of those references back to 30The C<track> function can help track down some of those references back to
32the variables containing them. 31the variables containing them.
33 32
34For example, for this fragment: 33For example, for this fragment:
35 34
36 package Test; 35 package Test;
36
37 use Devel::FindRef;
38 use Scalar::Util;
37 39
38 our $var = "hi\n"; 40 our $var = "hi\n";
39 my $x = \$var; 41 my $global_my = \$var;
40 our %hash = (ukukey => \$var); 42 our %global_hash = (ukukey => \$var);
41 our $hash2 = {ukukey2 => \$var}; 43 our $global_hashref = { ukukey2 => \$var };
42 44
43 sub testsub { 45 sub testsub {
44 my $local = $hash2; 46 my $testsub_local = $global_hashref;
45 print Devel::FindRef::track \$var; 47 print Devel::FindRef::track \$var;
46 } 48 }
47 49
48 testsub; 50 my $closure = sub {
51 my $closure_var = \$_[0];
52 Scalar::Util::weaken (my $weak_ref = \$var);
53 testsub;
54 };
55
56 $closure->($var);
49 57
50The output is as follows (or similar to this, in case I forget to update 58The output is as follows (or similar to this, in case I forget to update
51the manpage after some changes): 59the manpage after some changes):
52 60
53 SCALAR(0x814ece8) is 61 SCALAR(0x7cc888) [refcount 6] is
62 +- referenced by REF(0x8abcc8) [refcount 1], which is
63 | the lexical '$closure_var' in CODE(0x8abc50) [refcount 4], which is
64 | +- the closure created at tst:18.
65 | +- referenced by REF(0x7d3c58) [refcount 1], which is
66 | | the lexical '$closure' in CODE(0x7ae530) [refcount 2], which is
67 | | +- the containing scope for CODE(0x8ab430) [refcount 3], which is
68 | | | the global &Test::testsub.
69 | | +- the main body of the program.
70 | +- the lexical '&' in CODE(0x7ae530) [refcount 2], which was seen before.
71 +- referenced by REF(0x7cc7c8) [refcount 1], which is
72 | the lexical '$global_my' in CODE(0x7ae530) [refcount 2], which was seen before.
54 +- in the global $Test::var. 73 +- the global $Test::var.
55 +- referenced by REF(0x814f9e4), which is 74 +- referenced by REF(0x7cc558) [refcount 1], which is
56 | in the lexical '$x' in CODE(0x814ed78), which is 75 | the member 'ukukey2' of HASH(0x7ae140) [refcount 2], which is
57 | the containing scope for CODE(0x820c4b0), which is 76 | +- referenced by REF(0x8abad0) [refcount 1], which is
58 | in the global &Test::testsub. 77 | | the lexical '$testsub_local' in CODE(0x8ab430) [refcount 3], which was seen before.
78 | +- referenced by REF(0x8ab4f0) [refcount 1], which is
79 | the global $Test::global_hashref.
59 +- referenced by REF(0x814ed6c), which is 80 +- referenced by REF(0x7ae518) [refcount 1], which is
60 | in the member 'ukukey' of HASH(0x81da20c), which is 81 | the member 'ukukey' of HASH(0x7d3bb0) [refcount 1], which is
61 | in the global %Test::hash. 82 | the global %Test::global_hash.
62 +- referenced by REF(0x814ec28), which is 83 +- referenced by REF(0x7ae2f0) [refcount 1], which is
63 | not found anywhere I looked :( 84 a temporary on the stack.
64 +- referenced by REF(0x814eb44), which is
65 in the member 'ukukey2' of HASH(0x814f99c), which is
66 +- referenced by REF(0x820c450), which is
67 | in the lexical '$local' in CODE(0x820c4b0), which was seen before.
68 +- referenced by REF(0x820c204), which is
69 in the global $Test::hash2.
70 85
71It is a bit convoluted to read, but basically it says that the value 86It is a bit convoluted to read, but basically it says that the value
72stored in C<$var> can be found: 87stored in C<$var> is referenced by:
73 88
74=over 4 89=over 4
75 90
76=item - in some variable C<$x> whose origin is not known (I frankly have no 91=item - the lexical C<$closure_var> (0x8abcc8), which is inside an instantiated
77idea why, hints accepted). 92closure, which in turn is used quite a bit.
78 93
79=item - in the hash element with key C<ukukey> in the hash stored in C<%Test::hash>. 94=item - the package-level lexical C<$global_my>.
80 95
81=item - in the global variable named C<$Test::var>. 96=item - the global package variable named C<$Test::var>.
82 97
83=item - in the hash element C<ukukey2>, in the hash in the my variable 98=item - the hash element C<ukukey2>, in the hash in the my variable
84C<$local> in the sub C<Test::testsub> and also in the hash referenced by 99C<$testsub_local> in the sub C<Test::testsub> and also in the hash
100C<$referenced by Test::hash2>.
101
102=item - the hash element with key C<ukukey> in the hash stored in
85C<$Test::hash2>. 103C<%Test::hash>.
104
105=item - some anonymous mortalised reference on the stack (which is caused
106by calling C<track> with the expression C<\$var>, which creates the
107reference).
86 108
87=back 109=back
110
111And all these account for six reference counts.
88 112
89=head1 EXPORTS 113=head1 EXPORTS
90 114
91None. 115None.
92 116
… …
98 122
99Track the perl value pointed to by C<$ref> up to a depth of C<$depth> and 123Track the perl value pointed to by C<$ref> up to a depth of C<$depth> and
100return a descriptive string. C<$ref> can point at any perl value, be it 124return a descriptive string. C<$ref> can point at any perl value, be it
101anonymous sub, hash, array, scalar etc. 125anonymous sub, hash, array, scalar etc.
102 126
103This is the function you most often use. 127This is the function you most likely want to use when tracking down
128references.
104 129
105=cut 130=cut
106 131
107sub find($); 132sub find($);
133
134sub _f($) {
135 "$_[0] [refcount " . (_refcnt $_[0]) . "]"
136}
108 137
109sub track { 138sub track {
110 my ($ref, $depth) = @_; 139 my ($ref, $depth) = @_;
111 @_ = (); 140 @_ = ();
112 141
… …
120 149
121 if ($depth) { 150 if ($depth) {
122 my (@about) = find $$refref; 151 my (@about) = find $$refref;
123 if (@about) { 152 if (@about) {
124 for my $about (@about) { 153 for my $about (@about) {
154 $about->[0] =~ s/([^\x20-\x7e])/sprintf "\\{%02x}", ord $1/ge;
125 $buf .= "$indent" . (@about > 1 ? "+- " : " ") . $about->[0]; 155 $buf .= "$indent" . (@about > 1 ? "+- " : "") . $about->[0];
126 if (@$about > 1) { 156 if (@$about > 1) {
127 if ($seen{ref2ptr $about->[1]}++) { 157 if ($seen{ref2ptr $about->[1]}++) {
128 $buf .= " $about->[1], which was seen before.\n"; 158 $buf .= " " . (_f $about->[1]) . ", which was seen before.\n";
129 } else { 159 } else {
130 $buf .= " $about->[1], which is\n"; 160 $buf .= " " . (_f $about->[1]) . ", which is\n";
131 $track->(\$about->[1], $depth - 1, $about == $about[-1] ? "$indent " : "$indent| "); 161 $track->(\$about->[1], $depth - 1, $about == $about[-1] ? "$indent " : "$indent| ");
132 } 162 }
133 } else { 163 } else {
134 $buf .= ".\n"; 164 $buf .= ".\n";
135 } 165 }
… …
140 } else { 170 } else {
141 $buf .= "$indent not referenced within the search depth.\n"; 171 $buf .= "$indent not referenced within the search depth.\n";
142 } 172 }
143 }; 173 };
144 174
145 $buf .= "$ref is\n"; 175 $buf .= (_f $ref) . " is\n";
176
146 $track->(\$ref, $depth || $ENV{PERL_DEVEL_FINDREF_DEPTH} || 10, ""); 177 $track->(\$ref, $depth || $ENV{PERL_DEVEL_FINDREF_DEPTH} || 10, "");
147 $buf 178 $buf
148} 179}
149 180
150=item @references = Devel::FindRef::find $ref 181=item @references = Devel::FindRef::find $ref
… …
160=cut 191=cut
161 192
162sub find($) { 193sub find($) {
163 my ($about, $excl) = &find_; 194 my ($about, $excl) = &find_;
164 my %excl = map +($_ => undef), @$excl; 195 my %excl = map +($_ => undef), @$excl;
165 grep !exists $excl{ref2ptr $_->[1]}, @$about 196 grep !($#$_ && exists $excl{ref2ptr $_->[1]}), @$about
166} 197}
167 198
168=item $ref = Devel::FindRef::ptr2ref $integer 199=item $ref = Devel::FindRef::ptr2ref $integer
169 200
170Sometimes you know (from debugging output) the address of a perl scalar 201Sometimes you know (from debugging output) the address of a perl value you
171you are interested in (e.g. C<HASH(0x176ff70)>). This function can be used 202are interested in (e.g. C<HASH(0x176ff70)>). This function can be used to
172to turn the address into a reference to that scalar. It is quite safe to 203turn the address into a reference to that value. It is quite safe to call
173call on valid addresses, but extremely dangerous to call on invalid ones. 204on valid addresses, but extremely dangerous to call on invalid ones. I<No
205checks whatsoever will be done>, so don't use this unless you really know
206the value is the address of a valid perl value.
174 207
175 # we know that HASH(0x176ff70) exists, so turn it into a hashref: 208 # we know that HASH(0x176ff70) exists, so turn it into a hashref:
176 my $ref_to_hash = Devel::FindRef::ptr2ref 0x176ff70; 209 my $ref_to_hash = Devel::FindRef::ptr2ref 0x176ff70;
177 210
178=item $ref = Devel::FindRef::ref2ptr $reference 211=item $ptr = Devel::FindRef::ref2ptr $reference
179 212
180The opposite of C<ptr2ref>, above: returns the internal address of the 213The opposite of C<ptr2ref>, above: returns the internal address of the
181value pointed to by the passed reference. I<No checks whatsoever will be 214value pointed to by the passed reference. This function is safe to call on
182done>, so don't use this. 215anything, and returns the same value that a normal reference would if used
216in a numeric context.
183 217
184=back 218=back
185 219
186=head1 ENVIRONMENT VARIABLES 220=head1 ENVIRONMENT VARIABLES
187 221
188You can set the environment variable C<PERL_DEVEL_FINDREF_DEPTH> to an 222You 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 223integer to override the default depth in C<track>. If a call explicitly
190specified a depth it is not overridden. 224specifies a depth, it is not overridden.
191 225
192=head1 AUTHOR 226=head1 AUTHOR
193 227
194Marc Lehmann <pcg@goof.com>. 228Marc Lehmann <pcg@goof.com>.
195 229
196=head1 COPYRIGHT AND LICENSE 230=head1 COPYRIGHT AND LICENSE
197 231
198Copyright (C) 2007, 2008 by Marc Lehmann. 232Copyright (C) 2007, 2008, 2009, 2013 by Marc Lehmann.
199 233
200This library is free software; you can redistribute it and/or modify 234This library is free software; you can redistribute it and/or modify
201it under the same terms as Perl itself, either Perl version 5.8.8 or, 235it under the same terms as Perl itself, either Perl version 5.8.8 or,
202at your option, any later version of Perl 5 you may have available. 236at your option, any later version of Perl 5 you may have available.
203 237

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