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1 | package B::Showlex; |
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2 | |
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3 | our $VERSION = '1.02'; |
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4 | |
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5 | use strict; |
6 | use B qw(svref_2object comppadlist class); |
7 | use B::Terse (); |
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8 | use B::Concise (); |
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9 | |
10 | # |
11 | # Invoke as |
12 | # perl -MO=Showlex,foo bar.pl |
13 | # to see the names of lexical variables used by &foo |
14 | # or as |
15 | # perl -MO=Showlex bar.pl |
16 | # to see the names of file scope lexicals used by bar.pl |
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17 | # |
18 | |
19 | |
20 | # borrowed from B::Concise |
21 | our $walkHandle = \*STDOUT; |
22 | |
23 | sub walk_output { # updates $walkHandle |
24 | $walkHandle = B::Concise::walk_output(@_); |
25 | #print "got $walkHandle"; |
26 | #print $walkHandle "using it"; |
27 | $walkHandle; |
28 | } |
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29 | |
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30 | sub shownamearray { |
31 | my ($name, $av) = @_; |
32 | my @els = $av->ARRAY; |
33 | my $count = @els; |
34 | my $i; |
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35 | print $walkHandle "$name has $count entries\n"; |
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36 | for ($i = 0; $i < $count; $i++) { |
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37 | my $sv = $els[$i]; |
38 | if (class($sv) ne "SPECIAL") { |
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39 | printf $walkHandle "$i: %s (0x%lx) %s\n", class($sv), $$sv, $sv->PVX; |
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40 | } else { |
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41 | printf $walkHandle "$i: %s\n", $sv->terse; |
42 | #printf $walkHandle "$i: %s\n", B::Concise::concise_sv($sv); |
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43 | } |
44 | } |
45 | } |
46 | |
47 | sub showvaluearray { |
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48 | my ($name, $av) = @_; |
49 | my @els = $av->ARRAY; |
50 | my $count = @els; |
51 | my $i; |
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52 | print $walkHandle "$name has $count entries\n"; |
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53 | for ($i = 0; $i < $count; $i++) { |
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54 | printf $walkHandle "$i: %s\n", $els[$i]->terse; |
55 | #print $walkHandle "$i: %s\n", B::Concise::concise_sv($els[$i]); |
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56 | } |
57 | } |
58 | |
59 | sub showlex { |
60 | my ($objname, $namesav, $valsav) = @_; |
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61 | shownamearray("Pad of lexical names for $objname", $namesav); |
62 | showvaluearray("Pad of lexical values for $objname", $valsav); |
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63 | } |
64 | |
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65 | my ($newlex, $nosp1); # rendering state vars |
66 | |
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67 | sub newlex { # drop-in for showlex |
68 | my ($objname, $names, $vals) = @_; |
69 | my @names = $names->ARRAY; |
70 | my @vals = $vals->ARRAY; |
71 | my $count = @names; |
72 | print $walkHandle "$objname Pad has $count entries\n"; |
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73 | printf $walkHandle "0: %s\n", $names[0]->terse unless $nosp1; |
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74 | for (my $i = 1; $i < $count; $i++) { |
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75 | printf $walkHandle "$i: %s = %s\n", $names[$i]->terse, $vals[$i]->terse |
76 | unless $nosp1 and $names[$i]->terse =~ /SPECIAL/; |
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77 | } |
78 | } |
79 | |
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80 | sub showlex_obj { |
81 | my ($objname, $obj) = @_; |
82 | $objname =~ s/^&main::/&/; |
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83 | showlex($objname, svref_2object($obj)->PADLIST->ARRAY) if !$newlex; |
84 | newlex ($objname, svref_2object($obj)->PADLIST->ARRAY) if $newlex; |
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85 | } |
86 | |
87 | sub showlex_main { |
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88 | showlex("comppadlist", comppadlist->ARRAY) if !$newlex; |
89 | newlex ("main", comppadlist->ARRAY) if $newlex; |
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90 | } |
91 | |
92 | sub compile { |
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93 | my @options = grep(/^-/, @_); |
94 | my @args = grep(!/^-/, @_); |
95 | for my $o (@options) { |
96 | $newlex = 1 if $o eq "-newlex"; |
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97 | $nosp1 = 1 if $o eq "-nosp"; |
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98 | } |
99 | |
100 | return \&showlex_main unless @args; |
101 | return sub { |
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102 | my $objref; |
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103 | foreach my $objname (@args) { |
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104 | next unless $objname; # skip nulls w/o carping |
105 | |
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106 | if (ref $objname) { |
107 | print $walkHandle "B::Showlex::compile($objname)\n"; |
108 | $objref = $objname; |
109 | } else { |
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110 | $objname = "main::$objname" unless $objname =~ /::/; |
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111 | print $walkHandle "$objname:\n"; |
112 | no strict 'refs'; |
113 | die "err: unknown function ($objname)\n" |
114 | unless *{$objname}{CODE}; |
115 | $objref = \&$objname; |
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116 | } |
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117 | showlex_obj($objname, $objref); |
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118 | } |
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119 | } |
120 | } |
121 | |
122 | 1; |
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123 | |
124 | __END__ |
125 | |
126 | =head1 NAME |
127 | |
128 | B::Showlex - Show lexical variables used in functions or files |
129 | |
130 | =head1 SYNOPSIS |
131 | |
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132 | perl -MO=Showlex[,-OPTIONS][,SUBROUTINE] foo.pl |
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133 | |
134 | =head1 DESCRIPTION |
135 | |
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136 | When a comma-separated list of subroutine names is given as options, Showlex |
137 | prints the lexical variables used in those subroutines. Otherwise, it prints |
138 | the file-scope lexicals in the file. |
139 | |
140 | =head1 EXAMPLES |
141 | |
142 | Traditional form: |
143 | |
144 | $ perl -MO=Showlex -e 'my ($i,$j,$k)=(1,"foo")' |
145 | Pad of lexical names for comppadlist has 4 entries |
146 | 0: SPECIAL #1 &PL_sv_undef |
147 | 1: PVNV (0x9db0fb0) $i |
148 | 2: PVNV (0x9db0f38) $j |
149 | 3: PVNV (0x9db0f50) $k |
150 | Pad of lexical values for comppadlist has 5 entries |
151 | 0: SPECIAL #1 &PL_sv_undef |
152 | 1: NULL (0x9da4234) |
153 | 2: NULL (0x9db0f2c) |
154 | 3: NULL (0x9db0f44) |
155 | 4: NULL (0x9da4264) |
156 | -e syntax OK |
157 | |
158 | New-style form: |
159 | |
160 | $ perl -MO=Showlex,-newlex -e 'my ($i,$j,$k)=(1,"foo")' |
161 | main Pad has 4 entries |
162 | 0: SPECIAL #1 &PL_sv_undef |
163 | 1: PVNV (0xa0c4fb8) "$i" = NULL (0xa0b8234) |
164 | 2: PVNV (0xa0c4f40) "$j" = NULL (0xa0c4f34) |
165 | 3: PVNV (0xa0c4f58) "$k" = NULL (0xa0c4f4c) |
166 | -e syntax OK |
167 | |
168 | New form, no specials, outside O framework: |
169 | |
170 | $ perl -MB::Showlex -e \ |
171 | 'my ($i,$j,$k)=(1,"foo"); B::Showlex::compile(-newlex,-nosp)->()' |
172 | main Pad has 4 entries |
173 | 1: PVNV (0x998ffb0) "$i" = IV (0x9983234) 1 |
174 | 2: PVNV (0x998ff68) "$j" = PV (0x998ff5c) "foo" |
175 | 3: PVNV (0x998ff80) "$k" = NULL (0x998ff74) |
176 | |
177 | Note that this example shows the values of the lexicals, whereas the other |
178 | examples did not (as they're compile-time only). |
179 | |
180 | =head2 OPTIONS |
181 | |
182 | The C<-newlex> option produces a more readable C<< name => value >> format, |
183 | and is shown in the second example above. |
184 | |
185 | The C<-nosp> option eliminates reporting of SPECIALs, such as C<0: SPECIAL |
186 | #1 &PL_sv_undef> above. Reporting of SPECIALs can sometimes overwhelm |
187 | your declared lexicals. |
188 | |
189 | =head1 SEE ALSO |
190 | |
191 | C<B::Showlex> can also be used outside of the O framework, as in the third |
192 | example. See C<B::Concise> for a fuller explanation of reasons. |
193 | |
194 | =head1 TODO |
195 | |
196 | Some of the reported info, such as hex addresses, is not particularly |
197 | valuable. Other information would be more useful for the typical |
198 | programmer, such as line-numbers, pad-slot reuses, etc.. Given this, |
199 | -newlex isnt a particularly good flag-name. |
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200 | |
201 | =head1 AUTHOR |
202 | |
203 | Malcolm Beattie, C<mbeattie@sable.ox.ac.uk> |
204 | |
205 | =cut |