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1 | # Disassembler.pm |
2 | # | |
3 | # Copyright (c) 1996 Malcolm Beattie | |
4 | # | |
5 | # You may distribute under the terms of either the GNU General Public | |
6 | # License or the Artistic License, as specified in the README file. | |
7 | package B::Disassembler::BytecodeStream; | |
8 | ||
9 | our $VERSION = '1.01'; | |
10 | ||
11 | use FileHandle; | |
12 | use Carp; | |
13 | use Config qw(%Config); | |
14 | use B qw(cstring cast_I32); | |
15 | @ISA = qw(FileHandle); | |
16 | sub readn { | |
17 | my ($fh, $len) = @_; | |
18 | my $data; | |
19 | read($fh, $data, $len); | |
20 | croak "reached EOF while reading $len bytes" unless length($data) == $len; | |
21 | return $data; | |
22 | } | |
23 | ||
24 | sub GET_U8 { | |
25 | my $fh = shift; | |
26 | my $c = $fh->getc; | |
27 | croak "reached EOF while reading U8" unless defined($c); | |
28 | return ord($c); | |
29 | } | |
30 | ||
31 | sub GET_U16 { | |
32 | my $fh = shift; | |
33 | my $str = $fh->readn(2); | |
34 | croak "reached EOF while reading U16" unless length($str) == 2; | |
35 | return unpack("S", $str); | |
36 | } | |
37 | ||
38 | sub GET_NV { | |
39 | my $fh = shift; | |
40 | my ($str, $c); | |
41 | while (defined($c = $fh->getc) && $c ne "\0") { | |
42 | $str .= $c; | |
43 | } | |
44 | croak "reached EOF while reading double" unless defined($c); | |
45 | return $str; | |
46 | } | |
47 | ||
48 | sub GET_U32 { | |
49 | my $fh = shift; | |
50 | my $str = $fh->readn(4); | |
51 | croak "reached EOF while reading U32" unless length($str) == 4; | |
52 | return unpack("L", $str); | |
53 | } | |
54 | ||
55 | sub GET_I32 { | |
56 | my $fh = shift; | |
57 | my $str = $fh->readn(4); | |
58 | croak "reached EOF while reading I32" unless length($str) == 4; | |
59 | return unpack("l", $str); | |
60 | } | |
61 | ||
62 | sub GET_objindex { | |
63 | my $fh = shift; | |
64 | my $str = $fh->readn(4); | |
65 | croak "reached EOF while reading objindex" unless length($str) == 4; | |
66 | return unpack("L", $str); | |
67 | } | |
68 | ||
69 | sub GET_opindex { | |
70 | my $fh = shift; | |
71 | my $str = $fh->readn(4); | |
72 | croak "reached EOF while reading opindex" unless length($str) == 4; | |
73 | return unpack("L", $str); | |
74 | } | |
75 | ||
76 | sub GET_svindex { | |
77 | my $fh = shift; | |
78 | my $str = $fh->readn(4); | |
79 | croak "reached EOF while reading svindex" unless length($str) == 4; | |
80 | return unpack("L", $str); | |
81 | } | |
82 | ||
83 | sub GET_pvindex { | |
84 | my $fh = shift; | |
85 | my $str = $fh->readn(4); | |
86 | croak "reached EOF while reading pvindex" unless length($str) == 4; | |
87 | return unpack("L", $str); | |
88 | } | |
89 | ||
90 | sub GET_strconst { | |
91 | my $fh = shift; | |
92 | my ($str, $c); | |
93 | $str = ''; | |
94 | while (defined($c = $fh->getc) && $c ne "\0") { | |
95 | $str .= $c; | |
96 | } | |
97 | croak "reached EOF while reading strconst" unless defined($c); | |
98 | return cstring($str); | |
99 | } | |
100 | ||
101 | sub GET_pvcontents {} | |
102 | ||
103 | sub GET_PV { | |
104 | my $fh = shift; | |
105 | my $str; | |
106 | my $len = $fh->GET_U32; | |
107 | if ($len) { | |
108 | read($fh, $str, $len); | |
109 | croak "reached EOF while reading PV" unless length($str) == $len; | |
110 | return cstring($str); | |
111 | } else { | |
112 | return '""'; | |
113 | } | |
114 | } | |
115 | ||
116 | sub GET_comment_t { | |
117 | my $fh = shift; | |
118 | my ($str, $c); | |
119 | while (defined($c = $fh->getc) && $c ne "\n") { | |
120 | $str .= $c; | |
121 | } | |
122 | croak "reached EOF while reading comment" unless defined($c); | |
123 | return cstring($str); | |
124 | } | |
125 | ||
126 | sub GET_double { | |
127 | my $fh = shift; | |
128 | my ($str, $c); | |
129 | while (defined($c = $fh->getc) && $c ne "\0") { | |
130 | $str .= $c; | |
131 | } | |
132 | croak "reached EOF while reading double" unless defined($c); | |
133 | return $str; | |
134 | } | |
135 | ||
136 | sub GET_none {} | |
137 | ||
138 | sub GET_op_tr_array { | |
139 | my $fh = shift; | |
140 | my @ary = unpack("S256", $fh->readn(256 * 2)); | |
141 | return join(",", @ary); | |
142 | } | |
143 | ||
144 | sub GET_IV64 { | |
145 | my $fh = shift; | |
146 | my ($hi, $lo) = unpack("LL", $fh->readn(8)); | |
147 | return sprintf("0x%x%08x", $hi, $lo); # cheat | |
148 | } | |
149 | ||
150 | sub GET_IV { | |
151 | $Config{ivsize} == 4 ? &GET_I32 : &GET_IV64; | |
152 | } | |
153 | ||
154 | package B::Disassembler; | |
155 | use Exporter; | |
156 | @ISA = qw(Exporter); | |
157 | @EXPORT_OK = qw(disassemble_fh get_header); | |
158 | use Carp; | |
159 | use strict; | |
160 | ||
161 | use B::Asmdata qw(%insn_data @insn_name); | |
162 | ||
163 | our( $magic, $archname, $blversion, $ivsize, $ptrsize, $byteorder ); | |
164 | ||
165 | sub dis_header($){ | |
166 | my( $fh ) = @_; | |
167 | $magic = $fh->GET_U32(); | |
168 | warn( "bad magic" ) if $magic != 0x43424c50; | |
169 | $archname = $fh->GET_strconst(); | |
170 | $blversion = $fh->GET_strconst(); | |
171 | $ivsize = $fh->GET_U32(); | |
172 | $ptrsize = $fh->GET_U32(); | |
173 | $byteorder = $fh->GET_strconst(); | |
174 | } | |
175 | ||
176 | sub get_header(){ | |
177 | return( $magic, $archname, $blversion, $ivsize, $ptrsize, $byteorder ); | |
178 | } | |
179 | ||
180 | sub disassemble_fh { | |
181 | my ($fh, $out) = @_; | |
182 | my ($c, $getmeth, $insn, $arg); | |
183 | bless $fh, "B::Disassembler::BytecodeStream"; | |
184 | dis_header( $fh ); | |
185 | while (defined($c = $fh->getc)) { | |
186 | $c = ord($c); | |
187 | $insn = $insn_name[$c]; | |
188 | if (!defined($insn) || $insn eq "unused") { | |
189 | my $pos = $fh->tell - 1; | |
190 | die "Illegal instruction code $c at stream offset $pos\n"; | |
191 | } | |
192 | $getmeth = $insn_data{$insn}->[2]; | |
193 | $arg = $fh->$getmeth(); | |
194 | if (defined($arg)) { | |
195 | &$out($insn, $arg); | |
196 | } else { | |
197 | &$out($insn); | |
198 | } | |
199 | } | |
200 | } | |
201 | ||
202 | 1; | |
203 | ||
204 | __END__ | |
205 | ||
206 | =head1 NAME | |
207 | ||
208 | B::Disassembler - Disassemble Perl bytecode | |
209 | ||
210 | =head1 SYNOPSIS | |
211 | ||
212 | use Disassembler; | |
213 | ||
214 | =head1 DESCRIPTION | |
215 | ||
216 | See F<ext/B/B/Disassembler.pm>. | |
217 | ||
218 | =head1 AUTHOR | |
219 | ||
220 | Malcolm Beattie, C<mbeattie@sable.ox.ac.uk> | |
221 | ||
222 | =cut |