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1 | # Assembler.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. |
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7 | |
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8 | package B::Assembler; |
9 | use Exporter; |
10 | use B qw(ppname); |
11 | use B::Asmdata qw(%insn_data @insn_name); |
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12 | use Config qw(%Config); |
13 | require ByteLoader; # we just need its $VERSIOM |
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14 | |
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15 | no warnings; # XXX |
16 | |
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17 | @ISA = qw(Exporter); |
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18 | @EXPORT_OK = qw(assemble_fh newasm endasm assemble asm); |
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19 | $VERSION = 0.05; |
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20 | |
21 | use strict; |
22 | my %opnumber; |
23 | my ($i, $opname); |
24 | for ($i = 0; defined($opname = ppname($i)); $i++) { |
25 | $opnumber{$opname} = $i; |
26 | } |
27 | |
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28 | my($linenum, $errors, $out); # global state, set up by newasm |
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29 | |
30 | sub error { |
31 | my $str = shift; |
32 | warn "$linenum: $str\n"; |
33 | $errors++; |
34 | } |
35 | |
36 | my $debug = 0; |
37 | sub debug { $debug = shift } |
38 | |
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39 | sub limcheck($$$$){ |
40 | my( $val, $lo, $hi, $loc ) = @_; |
41 | if( $val < $lo || $hi < $val ){ |
42 | error "argument for $loc outside [$lo, $hi]: $val"; |
43 | $val = $hi; |
44 | } |
45 | return $val; |
46 | } |
47 | |
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48 | # |
49 | # First define all the data conversion subs to which Asmdata will refer |
50 | # |
51 | |
52 | sub B::Asmdata::PUT_U8 { |
53 | my $arg = shift; |
54 | my $c = uncstring($arg); |
55 | if (defined($c)) { |
56 | if (length($c) != 1) { |
57 | error "argument for U8 is too long: $c"; |
58 | $c = substr($c, 0, 1); |
59 | } |
60 | } else { |
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61 | $arg = limcheck( $arg, 0, 0xff, 'U8' ); |
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62 | $c = chr($arg); |
63 | } |
64 | return $c; |
65 | } |
66 | |
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67 | sub B::Asmdata::PUT_U16 { |
68 | my $arg = limcheck( $_[0], 0, 0xffff, 'U16' ); |
69 | pack("S", $arg); |
70 | } |
71 | sub B::Asmdata::PUT_U32 { |
72 | my $arg = limcheck( $_[0], 0, 0xffffffff, 'U32' ); |
73 | pack("L", $arg); |
74 | } |
75 | sub B::Asmdata::PUT_I32 { |
76 | my $arg = limcheck( $_[0], -0x80000000, 0x7fffffff, 'I32' ); |
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77 | pack("l", $arg); |
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78 | } |
79 | sub B::Asmdata::PUT_NV { sprintf("%s\0", $_[0]) } # "%lf" looses precision and pack('d',...) |
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80 | # may not even be portable between compilers |
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81 | sub B::Asmdata::PUT_objindex { # could allow names here |
82 | my $arg = limcheck( $_[0], 0, 0xffffffff, '*index' ); |
83 | pack("L", $arg); |
84 | } |
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85 | sub B::Asmdata::PUT_svindex { &B::Asmdata::PUT_objindex } |
86 | sub B::Asmdata::PUT_opindex { &B::Asmdata::PUT_objindex } |
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87 | sub B::Asmdata::PUT_pvindex { &B::Asmdata::PUT_objindex } |
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88 | |
89 | sub B::Asmdata::PUT_strconst { |
90 | my $arg = shift; |
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91 | my $str = uncstring($arg); |
92 | if (!defined($str)) { |
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93 | error "bad string constant: $arg"; |
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94 | $str = ''; |
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95 | } |
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96 | if ($str =~ s/\0//g) { |
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97 | error "string constant argument contains NUL: $arg"; |
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98 | $str = ''; |
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99 | } |
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100 | return $str . "\0"; |
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101 | } |
102 | |
103 | sub B::Asmdata::PUT_pvcontents { |
104 | my $arg = shift; |
105 | error "extraneous argument: $arg" if defined $arg; |
106 | return ""; |
107 | } |
108 | sub B::Asmdata::PUT_PV { |
109 | my $arg = shift; |
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110 | my $str = uncstring($arg); |
111 | if( ! defined($str) ){ |
112 | error "bad string argument: $arg"; |
113 | $str = ''; |
114 | } |
115 | return pack("L", length($str)) . $str; |
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116 | } |
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117 | sub B::Asmdata::PUT_comment_t { |
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118 | my $arg = shift; |
119 | $arg = uncstring($arg); |
120 | error "bad string argument: $arg" unless defined($arg); |
121 | if ($arg =~ s/\n//g) { |
122 | error "comment argument contains linefeed: $arg"; |
123 | } |
124 | return $arg . "\n"; |
125 | } |
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126 | sub B::Asmdata::PUT_double { sprintf("%s\0", $_[0]) } # see PUT_NV above |
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127 | sub B::Asmdata::PUT_none { |
128 | my $arg = shift; |
129 | error "extraneous argument: $arg" if defined $arg; |
130 | return ""; |
131 | } |
132 | sub B::Asmdata::PUT_op_tr_array { |
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133 | my @ary = split /\s*,\s*/, shift; |
134 | return pack "S*", @ary; |
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135 | } |
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136 | |
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137 | sub B::Asmdata::PUT_IV64 { |
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138 | return pack "Q", shift; |
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139 | } |
140 | |
141 | sub B::Asmdata::PUT_IV { |
142 | $Config{ivsize} == 4 ? &B::Asmdata::PUT_I32 : &B::Asmdata::PUT_IV64; |
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143 | } |
144 | |
145 | my %unesc = (n => "\n", r => "\r", t => "\t", a => "\a", |
146 | b => "\b", f => "\f", v => "\013"); |
147 | |
148 | sub uncstring { |
149 | my $s = shift; |
150 | $s =~ s/^"// and $s =~ s/"$// or return undef; |
151 | $s =~ s/\\(\d\d\d|.)/length($1) == 3 ? chr(oct($1)) : ($unesc{$1}||$1)/eg; |
152 | return $s; |
153 | } |
154 | |
155 | sub strip_comments { |
156 | my $stmt = shift; |
157 | # Comments only allowed in instructions which don't take string arguments |
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158 | # Treat string as a single line so .* eats \n characters. |
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159 | $stmt =~ s{ |
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160 | ^\s* # Ignore leading whitespace |
161 | ( |
162 | [^"]* # A double quote '"' indicates a string argument. If we |
163 | # find a double quote, the match fails and we strip nothing. |
164 | ) |
165 | \s*\# # Any amount of whitespace plus the comment marker... |
166 | .*$ # ...which carries on to end-of-string. |
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167 | }{$1}sx; # Keep only the instruction and optional argument. |
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168 | return $stmt; |
169 | } |
170 | |
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171 | # create the ByteCode header: magic, archname, ByteLoader $VERSION, ivsize, |
172 | # ptrsize, byteorder |
173 | # nvtype is irrelevant (floats are stored as strings) |
174 | # byteorder is strconst not U32 because of varying size issues |
175 | |
176 | sub gen_header { |
177 | my $header = ""; |
178 | |
179 | $header .= B::Asmdata::PUT_U32(0x43424c50); # 'PLBC' |
180 | $header .= B::Asmdata::PUT_strconst('"' . $Config{archname}. '"'); |
181 | $header .= B::Asmdata::PUT_strconst(qq["$ByteLoader::VERSION"]); |
182 | $header .= B::Asmdata::PUT_U32($Config{ivsize}); |
183 | $header .= B::Asmdata::PUT_U32($Config{ptrsize}); |
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184 | $header; |
185 | } |
186 | |
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187 | sub parse_statement { |
188 | my $stmt = shift; |
189 | my ($insn, $arg) = $stmt =~ m{ |
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190 | ^\s* # allow (but ignore) leading whitespace |
191 | (.*?) # Instruction continues up until... |
192 | (?: # ...an optional whitespace+argument group |
193 | \s+ # first whitespace. |
194 | (.*) # The argument is all the rest (newlines included). |
195 | )?$ # anchor at end-of-line |
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196 | }sx; |
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197 | if (defined($arg)) { |
198 | if ($arg =~ s/^0x(?=[0-9a-fA-F]+$)//) { |
199 | $arg = hex($arg); |
200 | } elsif ($arg =~ s/^0(?=[0-7]+$)//) { |
201 | $arg = oct($arg); |
202 | } elsif ($arg =~ /^pp_/) { |
203 | $arg =~ s/\s*$//; # strip trailing whitespace |
204 | my $opnum = $opnumber{$arg}; |
205 | if (defined($opnum)) { |
206 | $arg = $opnum; |
207 | } else { |
208 | error qq(No such op type "$arg"); |
209 | $arg = 0; |
210 | } |
211 | } |
212 | } |
213 | return ($insn, $arg); |
214 | } |
215 | |
216 | sub assemble_insn { |
217 | my ($insn, $arg) = @_; |
218 | my $data = $insn_data{$insn}; |
219 | if (defined($data)) { |
220 | my ($bytecode, $putsub) = @{$data}[0, 1]; |
221 | my $argcode = &$putsub($arg); |
222 | return chr($bytecode).$argcode; |
223 | } else { |
224 | error qq(no such instruction "$insn"); |
225 | return ""; |
226 | } |
227 | } |
228 | |
229 | sub assemble_fh { |
230 | my ($fh, $out) = @_; |
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231 | my $line; |
232 | my $asm = newasm($out); |
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233 | while ($line = <$fh>) { |
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234 | assemble($line); |
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235 | } |
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236 | endasm(); |
237 | } |
238 | |
239 | sub newasm { |
240 | my($outsub) = @_; |
241 | |
242 | die "Invalid printing routine for B::Assembler\n" unless ref $outsub eq 'CODE'; |
243 | die <<EOD if ref $out; |
244 | Can't have multiple byteassembly sessions at once! |
245 | (perhaps you forgot an endasm()?) |
246 | EOD |
247 | |
248 | $linenum = $errors = 0; |
249 | $out = $outsub; |
250 | |
251 | $out->(gen_header()); |
252 | } |
253 | |
254 | sub endasm { |
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255 | if ($errors) { |
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256 | die "There were $errors assembly errors\n"; |
257 | } |
258 | $linenum = $errors = $out = 0; |
259 | } |
260 | |
261 | sub assemble { |
262 | my($line) = @_; |
263 | my ($insn, $arg); |
264 | $linenum++; |
265 | chomp $line; |
266 | if ($debug) { |
267 | my $quotedline = $line; |
268 | $quotedline =~ s/\\/\\\\/g; |
269 | $quotedline =~ s/"/\\"/g; |
270 | $out->(assemble_insn("comment", qq("$quotedline"))); |
271 | } |
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272 | if( $line = strip_comments($line) ){ |
273 | ($insn, $arg) = parse_statement($line); |
274 | $out->(assemble_insn($insn, $arg)); |
275 | if ($debug) { |
276 | $out->(assemble_insn("nop", undef)); |
277 | } |
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278 | } |
279 | } |
280 | |
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281 | ### temporary workaround |
282 | |
283 | sub asm { |
284 | return if $_[0] =~ /\s*\W/; |
285 | if (defined $_[1]) { |
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286 | return if $_[1] eq "0" and $_[0] !~ /^(?:newsvx?|av_pushx?|xav_flags)$/; |
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287 | return if $_[1] eq "1" and $_[0] =~ /^(?:sv_refcnt)$/; |
288 | } |
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289 | assemble "@_"; |
290 | } |
291 | |
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292 | 1; |
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293 | |
294 | __END__ |
295 | |
296 | =head1 NAME |
297 | |
298 | B::Assembler - Assemble Perl bytecode |
299 | |
300 | =head1 SYNOPSIS |
301 | |
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302 | use B::Assembler qw(newasm endasm assemble); |
303 | newasm(\&printsub); # sets up for assembly |
304 | assemble($buf); # assembles one line |
305 | endasm(); # closes down |
306 | |
307 | use B::Assembler qw(assemble_fh); |
308 | assemble_fh($fh, \&printsub); # assemble everything in $fh |
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309 | |
310 | =head1 DESCRIPTION |
311 | |
312 | See F<ext/B/B/Assembler.pm>. |
313 | |
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314 | =head1 AUTHORS |
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315 | |
316 | Malcolm Beattie, C<mbeattie@sable.ox.ac.uk> |
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317 | Per-statement interface by Benjamin Stuhl, C<sho_pi@hotmail.com> |
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318 | |
319 | =cut |