1 | package Devel::FindRef; |
1 | package Devel::FindRef; |
2 | |
2 | |
3 | use strict; |
3 | use strict; |
4 | |
4 | |
5 | use XSLoader; |
5 | use XSLoader; |
6 | |
6 | use Scalar::Util; |
7 | |
7 | |
8 | BEGIN { |
8 | BEGIN { |
9 | our $VERSION = '0.2'; |
9 | our $VERSION = '1.3'; |
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 scalar 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; |
20 | |
20 | |
… | |
… | |
45 | testsub; |
45 | testsub; |
46 | |
46 | |
47 | The output is as follows (or similar to this, in case I forget to update |
47 | The output is as follows (or similar to this, in case I forget to update |
48 | the manpage after some changes): |
48 | the manpage after some changes): |
49 | |
49 | |
50 | SCALAR(0x676fa0) is |
50 | SCALAR(0x814ece8) is |
|
|
51 | +- in the global $Test::var. |
51 | referenced by REF(0x676fb0), which is |
52 | +- referenced by REF(0x814f9e4), which is |
52 | in the lexical '$x' in CODE(0x676370), which is |
53 | | in the lexical '$x' in CODE(0x814ed78), which is |
53 | not found anywhere I looked :( |
54 | | the containing scope for CODE(0x820c4b0), which is |
|
|
55 | | in the global &Test::testsub. |
54 | referenced by REF(0x676360), which is |
56 | +- referenced by REF(0x814ed6c), which is |
55 | in the member 'ukukey' of HASH(0x756660), which is |
57 | | in the member 'ukukey' of HASH(0x81da20c), which is |
56 | in the global %Test::hash. |
58 | | in the global %Test::hash. |
57 | in the global $Test::var. |
|
|
58 | referenced by REF(0x6760e0), which is |
59 | +- referenced by REF(0x814ec28), which is |
|
|
60 | | not found anywhere I looked :( |
|
|
61 | +- referenced by REF(0x814eb44), which is |
59 | in the member 'ukukey2' of HASH(0x676f30), which is |
62 | in the member 'ukukey2' of HASH(0x814f99c), which is |
60 | referenced by REF(0x77bcf0), which is |
63 | +- referenced by REF(0x820c450), which is |
61 | in the lexical '$local' in CODE(0x77bcb0), which is |
64 | | in the lexical '$local' in CODE(0x820c4b0), which was seen before. |
62 | in the global &Test::testsub. |
|
|
63 | referenced by REF(0x77bc80), which is |
65 | +- referenced by REF(0x820c204), which is |
64 | in the global $Test::hash2. |
66 | in the global $Test::hash2. |
65 | |
|
|
66 | |
67 | |
67 | It is a bit convoluted to read, but basically it says that the value |
68 | It is a bit convoluted to read, but basically it says that the value |
68 | stored in C<$var> can be found: |
69 | stored in C<$var> can be found: |
69 | |
70 | |
70 | =over 4 |
71 | =over 4 |
… | |
… | |
101 | =cut |
102 | =cut |
102 | |
103 | |
103 | sub find($); |
104 | sub find($); |
104 | |
105 | |
105 | sub track { |
106 | sub track { |
|
|
107 | my ($ref, $depth) = @_; |
|
|
108 | @_ = (); |
|
|
109 | |
106 | my $buf = ""; |
110 | my $buf = ""; |
107 | my %ignore; |
111 | my %seen; |
|
|
112 | |
|
|
113 | Scalar::Util::weaken $ref; |
108 | |
114 | |
109 | my $track; $track = sub { |
115 | my $track; $track = sub { |
110 | my ($target, $depth, $indent) = @_; |
116 | my ($refref, $depth, $indent) = @_; |
111 | @_ = (); |
|
|
112 | local $ignore{$target+0} = undef; |
|
|
113 | |
117 | |
114 | if ($depth) { |
118 | if ($depth) { |
115 | my (@about) = grep !exists $ignore{$_->[1]}, find $target; |
119 | my (@about) = find $$refref; |
116 | if (@about) { |
120 | if (@about) { |
117 | local @ignore{map $_->[1]+0, @about} = (); |
|
|
118 | for my $about (@about) { |
121 | for my $about (@about) { |
119 | local $ignore{$about+0} = undef; |
122 | $buf .= "$indent" . (@about > 1 ? "+- " : " ") . $about->[0]; |
120 | $buf .= (" ") x $indent; |
|
|
121 | $buf .= $about->[0]; |
|
|
122 | if (@$about > 1) { |
123 | if (@$about > 1) { |
|
|
124 | if ($seen{ref2ptr $about->[1]}++) { |
|
|
125 | $buf .= " $about->[1], which was seen before.\n"; |
|
|
126 | } else { |
123 | $buf .= " $about->[1], which is\n"; |
127 | $buf .= " $about->[1], which is\n"; |
124 | $track->($about->[1], $depth - 1, $indent + 1); |
128 | $track->(\$about->[1], $depth - 1, $about == $about[-1] ? "$indent " : "$indent| "); |
|
|
129 | } |
125 | } else { |
130 | } else { |
126 | $buf .= ".\n"; |
131 | $buf .= ".\n"; |
127 | } |
132 | } |
128 | } |
133 | } |
129 | } else { |
134 | } else { |
130 | $buf .= (" ") x $indent; |
|
|
131 | $buf .= "not found anywhere I looked :(\n"; |
135 | $buf .= "$indent not found anywhere I looked :(\n"; |
132 | } |
136 | } |
133 | } else { |
137 | } else { |
134 | $buf .= (" ") x $indent; |
|
|
135 | $buf .= "not referenced within the search depth.\n"; |
138 | $buf .= "$indent not referenced within the search depth.\n"; |
136 | } |
139 | } |
137 | }; |
140 | }; |
138 | |
141 | |
139 | $buf .= "$_[0] is\n"; |
142 | $buf .= "$ref is\n"; |
140 | $track->($_[0], $_[1] || 10, 1); |
143 | $track->(\$ref, $depth || $ENV{PERL_DEVEL_FINDREF_DEPTH} || 10, ""); |
141 | $buf |
144 | $buf |
142 | } |
145 | } |
143 | |
146 | |
144 | =item @references = Devel::FindRef::find $ref |
147 | =item @references = Devel::FindRef::find $ref |
145 | |
148 | |
146 | Return arrayrefs that contain [$message, $ref] pairs. The message |
149 | Return arrayrefs that contain [$message, $ref] pairs. The message |
147 | describes what kind of reference was found and the C<$ref> is the |
150 | describes what kind of reference was found and the C<$ref> is the |
148 | reference itself, which cna be omitted if C<find> decided to end the |
151 | reference itself, which can be omitted if C<find> decided to end the |
149 | search. |
152 | search. The returned references are all weak references. |
150 | |
153 | |
151 | The C<track> function uses this to find references to the value you are |
154 | The C<track> function uses this to find references to the value you are |
152 | interested in and recurses on the returned references. |
155 | interested in and recurses on the returned references. |
153 | |
156 | |
154 | =cut |
157 | =cut |
155 | |
158 | |
156 | sub find($) { |
159 | sub find($) { |
157 | my ($about, $excl) = &find_; |
160 | my ($about, $excl) = &find_; |
158 | my %excl = map +($_ => undef), @$excl; |
161 | my %excl = map +($_ => undef), @$excl; |
159 | grep !exists $excl{$_->[1] + 0}, @$about |
162 | grep !exists $excl{ref2ptr $_->[1]}, @$about |
160 | } |
163 | } |
161 | |
164 | |
162 | =item $ref = Devel::FindRef::ref2ptr $ptr |
165 | =item $ref = Devel::FindRef::ptr2ref $integer |
163 | |
166 | |
164 | Sometimes you know (from debugging output) the address of a perl scalar |
167 | Sometimes you know (from debugging output) the address of a perl scalar |
165 | you are interested in. This function can be used to turn the address into |
168 | you are interested in (e.g. C<HASH(0x176ff70)>). This function can be used |
166 | a reference to that scalar. It is quite safe to call on valid addresses, |
169 | to turn the address into a reference to that scalar. It is quite safe to |
167 | but extremely dangerous to call on invalid ones. |
170 | call on valid addresses, but extremely dangerous to call on invalid ones. |
|
|
171 | |
|
|
172 | # we know that HASH(0x176ff70) exists, so turn it into a hashref: |
|
|
173 | my $ref_to_hash = Devel::FindRef::ptr2ref 0x176ff70; |
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|
174 | |
|
|
175 | =item $ref = Devel::FindRef::ref2ptr $reference |
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176 | |
|
|
177 | 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 |
|
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179 | done>, so don't use this. |
168 | |
180 | |
169 | =back |
181 | =back |
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182 | |
|
|
183 | =head1 ENVIRONMENT VARIABLES |
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184 | |
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185 | You can set the environment variable C<PERL_DEVEL_FINDREF_DEPTH> to an |
|
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186 | integer to override the default depth in C<track>. If a call explicitly |
|
|
187 | specified a depth it is not overridden. |
170 | |
188 | |
171 | =head1 AUTHOR |
189 | =head1 AUTHOR |
172 | |
190 | |
173 | Marc Lehmann <pcg@goof.com>. |
191 | Marc Lehmann <pcg@goof.com>. |
174 | |
192 | |