3 # Copyright (c) 1996 Malcolm Beattie
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;
10 use B qw(cstring cast_I32);
11 @ISA = qw(FileHandle);
15 read($fh, $data, $len);
16 croak "reached EOF while reading $len bytes" unless length($data) == $len;
23 croak "reached EOF while reading U8" unless defined($c);
29 my $str = $fh->readn(2);
30 croak "reached EOF while reading U16" unless length($str) == 2;
31 return unpack("n", $str);
36 my $str = $fh->readn(4);
37 croak "reached EOF while reading U32" unless length($str) == 4;
38 return unpack("N", $str);
43 my $str = $fh->readn(4);
44 croak "reached EOF while reading I32" unless length($str) == 4;
45 return cast_I32(unpack("N", $str));
50 my $str = $fh->readn(4);
51 croak "reached EOF while reading objindex" unless length($str) == 4;
52 return unpack("N", $str);
57 my $str = $fh->readn(4);
58 croak "reached EOF while reading opindex" unless length($str) == 4;
59 return unpack("N", $str);
64 my $str = $fh->readn(4);
65 croak "reached EOF while reading svindex" unless length($str) == 4;
66 return unpack("N", $str);
72 while (defined($c = $fh->getc) && $c ne "\0") {
75 croak "reached EOF while reading strconst" unless defined($c);
84 my $len = $fh->GET_U32;
86 read($fh, $str, $len);
87 croak "reached EOF while reading PV" unless length($str) == $len;
97 while (defined($c = $fh->getc) && $c ne "\n") {
100 croak "reached EOF while reading comment" unless defined($c);
101 return cstring($str);
107 while (defined($c = $fh->getc) && $c ne "\0") {
110 croak "reached EOF while reading double" unless defined($c);
116 sub GET_op_tr_array {
118 my @ary = unpack("n256", $fh->readn(256 * 2));
119 return join(",", @ary);
124 my ($hi, $lo) = unpack("NN", $fh->readn(8));
125 return sprintf("0x%4x%04x", $hi, $lo); # cheat
128 package B::Disassembler;
131 @EXPORT_OK = qw(disassemble_fh);
135 use B::Asmdata qw(%insn_data @insn_name);
139 my ($c, $getmeth, $insn, $arg);
140 bless $fh, "B::Disassembler::BytecodeStream";
141 while (defined($c = $fh->getc)) {
143 $insn = $insn_name[$c];
144 if (!defined($insn) || $insn eq "unused") {
145 my $pos = $fh->tell - 1;
146 die "Illegal instruction code $c at stream offset $pos\n";
148 $getmeth = $insn_data{$insn}->[2];
149 $arg = $fh->$getmeth();
164 B::Disassembler - Disassemble Perl bytecode
172 See F<ext/B/B/Disassembler.pm>.
176 Malcolm Beattie, C<mbeattie@sable.ox.ac.uk>