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[perl5.git] / ext / B / B / Concise.pm
CommitLineData
c99ca59a
SM
1package B::Concise;
2# Copyright (C) 2000, 2001 Stephen McCamant. All rights reserved.
3# This program is free software; you can redistribute and/or modify it
4# under the same terms as Perl itself.
5
c99ca59a 6use strict;
78ad9108
PJ
7use warnings;
8
9use Exporter ();
10
11our $VERSION = "0.52";
12our @ISA = qw(Exporter);
13our @EXPORT_OK = qw(set_style add_callback);
14
c99ca59a
SM
15use B qw(class ppname main_start main_root main_cv cstring svref_2object
16 SVf_IOK SVf_NOK SVf_POK OPf_KIDS);
17
18my %style =
19 ("terse" =>
c3caa09d
SM
20 ["(?(#label =>\n)?)(*( )*)#class (#addr) #name (?([#targ])?) "
21 . "#svclass~(?((#svaddr))?)~#svval~(?(label \"#coplabel\")?)\n",
c99ca59a
SM
22 "(*( )*)goto #class (#addr)\n",
23 "#class pp_#name"],
24 "concise" =>
25 ["#hyphseq2 (*( (x( ;)x))*)<#classsym> "
26 . "#exname#arg(?([#targarglife])?)~#flags(?(/#private)?)(x(;~->#next)x)\n",
27 " (*( )*) goto #seq\n",
28 "(?(<#seq>)?)#exname#arg(?([#targarglife])?)"],
29 "linenoise" =>
30 ["(x(;(*( )*))x)#noise#arg(?([#targarg])?)(x( ;\n)x)",
31 "gt_#seq ",
32 "(?(#seq)?)#noise#arg(?([#targarg])?)"],
33 "debug" =>
34 ["#class (#addr)\n\top_next\t\t#nextaddr\n\top_sibling\t#sibaddr\n\t"
35 . "op_ppaddr\tPL_ppaddr[OP_#NAME]\n\top_type\t\t#typenum\n\top_seq\t\t"
36 . "#seqnum\n\top_flags\t#flagval\n\top_private\t#privval\n"
37 . "(?(\top_first\t#firstaddr\n)?)(?(\top_last\t\t#lastaddr\n)?)"
38 . "(?(\top_sv\t\t#svaddr\n)?)",
39 " GOTO #addr\n",
40 "#addr"],
41 "env" => [$ENV{B_CONCISE_FORMAT}, $ENV{B_CONCISE_GOTO_FORMAT},
42 $ENV{B_CONCISE_TREE_FORMAT}],
43 );
44
45my($format, $gotofmt, $treefmt);
46my $curcv;
47my($seq_base, $cop_seq_base);
78ad9108
PJ
48my @callbacks;
49
50sub set_style {
51 ($format, $gotofmt, $treefmt) = @_;
52}
53
54sub add_callback {
55 push @callbacks, @_;
56}
c99ca59a
SM
57
58sub concise_cv {
59 my ($order, $cvref) = @_;
60 my $cv = svref_2object($cvref);
61 $curcv = $cv;
62 if ($order eq "exec") {
63 walk_exec($cv->START);
64 } elsif ($order eq "basic") {
65 walk_topdown($cv->ROOT, sub { $_[0]->concise($_[1]) }, 0);
66 } else {
67 print tree($cv->ROOT, 0)
68 }
69}
70
71my $start_sym = "\e(0"; # "\cN" sometimes also works
72my $end_sym = "\e(B"; # "\cO" respectively
73
74my @tree_decorations =
75 ([" ", "--", "+-", "|-", "| ", "`-", "-", 1],
76 [" ", "-", "+", "+", "|", "`", "", 0],
77 [" ", map("$start_sym$_$end_sym", "qq", "wq", "tq", "x ", "mq", "q"), 1],
78 [" ", map("$start_sym$_$end_sym", "q", "w", "t", "x", "m"), "", 0],
79 );
80my $tree_style = 0;
81
82my $base = 36;
83my $big_endian = 1;
84
85my $order = "basic";
86
78ad9108
PJ
87set_style(@{$style{concise}});
88
c99ca59a
SM
89sub compile {
90 my @options = grep(/^-/, @_);
91 my @args = grep(!/^-/, @_);
92 my $do_main = 0;
c99ca59a
SM
93 for my $o (@options) {
94 if ($o eq "-basic") {
95 $order = "basic";
96 } elsif ($o eq "-exec") {
97 $order = "exec";
98 } elsif ($o eq "-tree") {
99 $order = "tree";
100 } elsif ($o eq "-compact") {
101 $tree_style |= 1;
102 } elsif ($o eq "-loose") {
103 $tree_style &= ~1;
104 } elsif ($o eq "-vt") {
105 $tree_style |= 2;
106 } elsif ($o eq "-ascii") {
107 $tree_style &= ~2;
108 } elsif ($o eq "-main") {
109 $do_main = 1;
110 } elsif ($o =~ /^-base(\d+)$/) {
111 $base = $1;
112 } elsif ($o eq "-bigendian") {
113 $big_endian = 1;
114 } elsif ($o eq "-littleendian") {
115 $big_endian = 0;
116 } elsif (exists $style{substr($o, 1)}) {
78ad9108 117 set_style(@{$style{substr($o, 1)}});
c99ca59a
SM
118 } else {
119 warn "Option $o unrecognized";
120 }
121 }
122 if (@args) {
123 return sub {
124 for my $objname (@args) {
125 $objname = "main::" . $objname unless $objname =~ /::/;
126 eval "concise_cv(\$order, \\&$objname)";
127 die "concise_cv($order, \\&$objname) failed: $@" if $@;
128 }
129 }
130 }
131 if (!@args or $do_main) {
132 if ($order eq "exec") {
133 return sub { return if class(main_start) eq "NULL";
134 $curcv = main_cv;
135 walk_exec(main_start) }
136 } elsif ($order eq "tree") {
137 return sub { return if class(main_root) eq "NULL";
138 $curcv = main_cv;
139 print tree(main_root, 0) }
140 } elsif ($order eq "basic") {
141 return sub { return if class(main_root) eq "NULL";
142 $curcv = main_cv;
143 walk_topdown(main_root,
144 sub { $_[0]->concise($_[1]) }, 0); }
145 }
146 }
147}
148
149my %labels;
150my $lastnext;
151
152my %opclass = ('OP' => "0", 'UNOP' => "1", 'BINOP' => "2", 'LOGOP' => "|",
153 'LISTOP' => "@", 'PMOP' => "/", 'SVOP' => "\$", 'GVOP' => "*",
051f02e9 154 'PVOP' => '"', 'LOOP' => "{", 'COP' => ";", 'PADOP' => "#");
c99ca59a 155
35fc55f1
RH
156no warnings 'qw'; # "Possible attempt to put comments..."
157my @linenoise =
158 qw'# () sc ( @? 1 $* gv *{ m$ m@ m% m? p/ *$ $ $# & a& pt \\ s\\ rf bl
c99ca59a
SM
159 ` *? <> ?? ?/ r/ c/ // qr s/ /c y/ = @= C sC Cp sp df un BM po +1 +I
160 -1 -I 1+ I+ 1- I- ** * i* / i/ %$ i% x + i+ - i- . " << >> < i<
161 > i> <= i, >= i. == i= != i! <? i? s< s> s, s. s= s! s? b& b^ b| -0 -i
162 ! ~ a2 si cs rd sr e^ lg sq in %x %o ab le ss ve ix ri sf FL od ch cy
163 uf lf uc lc qm @ [f [ @[ eh vl ky dl ex % ${ @{ uk pk st jn ) )[ a@
164 a% sl +] -] [- [+ so rv GS GW MS MW .. f. .f && || ^^ ?: &= |= -> s{ s}
165 v} ca wa di rs ;; ; ;d }{ { } {} f{ it {l l} rt }l }n }r dm }g }e ^o
166 ^c ^| ^# um bm t~ u~ ~d DB db ^s se ^g ^r {w }w pf pr ^O ^K ^R ^W ^d ^v
167 ^e ^t ^k t. fc ic fl .s .p .b .c .l .a .h g1 s1 g2 s2 ?. l? -R -W -X -r
168 -w -x -e -o -O -z -s -M -A -C -S -c -b -f -d -p -l -u -g -k -t -T -B cd
169 co cr u. cm ut r. l@ s@ r@ mD uD oD rD tD sD wD cD f$ w$ p$ sh e$ k$ g3
170 g4 s4 g5 s5 T@ C@ L@ G@ A@ S@ Hg Hc Hr Hw Mg Mc Ms Mr Sg Sc So rq do {e
171 e} {t t} g6 G6 6e g7 G7 7e g8 G8 8e g9 G9 9e 6s 7s 8s 9s 6E 7E 8E 9E Pn
35fc55f1 172 Pu GP SP EP Gn Gg GG SG EG g0 c$ lk t$ ;s n>';
c99ca59a
SM
173
174my $chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
175
176sub op_flags {
177 my($x) = @_;
178 my(@v);
179 push @v, "v" if ($x & 3) == 1;
180 push @v, "s" if ($x & 3) == 2;
181 push @v, "l" if ($x & 3) == 3;
182 push @v, "K" if $x & 4;
183 push @v, "P" if $x & 8;
184 push @v, "R" if $x & 16;
185 push @v, "M" if $x & 32;
186 push @v, "S" if $x & 64;
187 push @v, "*" if $x & 128;
188 return join("", @v);
189}
190
191sub base_n {
192 my $x = shift;
193 return "-" . base_n(-$x) if $x < 0;
194 my $str = "";
195 do { $str .= substr($chars, $x % $base, 1) } while $x = int($x / $base);
196 $str = reverse $str if $big_endian;
197 return $str;
198}
199
200sub seq { return $_[0]->seq ? base_n($_[0]->seq - $seq_base) : "-" }
201
202sub walk_topdown {
203 my($op, $sub, $level) = @_;
204 $sub->($op, $level);
205 if ($op->flags & OPf_KIDS) {
206 for (my $kid = $op->first; $$kid; $kid = $kid->sibling) {
207 walk_topdown($kid, $sub, $level + 1);
208 }
209 }
b2a3cfdd
RH
210 if (class($op) eq "PMOP" and $ {$op->pmreplroot}
211 and $op->pmreplroot->isa("B::OP")) {
c99ca59a
SM
212 walk_topdown($op->pmreplroot, $sub, $level + 1);
213 }
214}
215
216sub walklines {
217 my($ar, $level) = @_;
218 for my $l (@$ar) {
219 if (ref($l) eq "ARRAY") {
220 walklines($l, $level + 1);
221 } else {
222 $l->concise($level);
223 }
224 }
225}
226
227sub walk_exec {
228 my($top, $level) = @_;
229 my %opsseen;
230 my @lines;
231 my @todo = ([$top, \@lines]);
232 while (@todo and my($op, $targ) = @{shift @todo}) {
233 for (; $$op; $op = $op->next) {
234 last if $opsseen{$$op}++;
235 push @$targ, $op;
236 my $name = $op->name;
237 if ($name
238 =~ /^(or|and|(map|grep)while|entertry|range|cond_expr)$/) {
239 my $ar = [];
240 push @$targ, $ar;
241 push @todo, [$op->other, $ar];
242 } elsif ($name eq "subst" and $ {$op->pmreplstart}) {
243 my $ar = [];
244 push @$targ, $ar;
245 push @todo, [$op->pmreplstart, $ar];
246 } elsif ($name =~ /^enter(loop|iter)$/) {
247 $labels{$op->nextop->seq} = "NEXT";
248 $labels{$op->lastop->seq} = "LAST";
249 $labels{$op->redoop->seq} = "REDO";
250 }
251 }
252 }
253 walklines(\@lines, 0);
254}
255
256sub fmt_line {
257 my($hr, $fmt, $level) = @_;
258 my $text = $fmt;
259 $text =~ s/\(\?\(([^\#]*?)\#(\w+)([^\#]*?)\)\?\)/
260 $hr->{$2} ? $1.$hr->{$2}.$3 : ""/eg;
261 $text =~ s/\(x\((.*?);(.*?)\)x\)/$order eq "exec" ? $1 : $2/egs;
262 $text =~ s/\(\*\(([^;]*?)\)\*\)/$1 x $level/egs;
263 $text =~ s/\(\*\((.*?);(.*?)\)\*\)/$1 x ($level - 1) . $2 x ($level>0)/egs;
264 $text =~ s/#([a-zA-Z]+)(\d+)/sprintf("%-$2s", $hr->{$1})/eg;
265 $text =~ s/#([a-zA-Z]+)/$hr->{$1}/eg;
266 $text =~ s/[ \t]*~+[ \t]*/ /g;
267 return $text;
268}
269
270my %priv;
271$priv{$_}{128} = "LVINTRO"
272 for ("pos", "substr", "vec", "threadsv", "gvsv", "rv2sv", "rv2hv", "rv2gv",
273 "rv2av", "rv2arylen", "aelem", "helem", "aslice", "hslice", "padsv",
274 "padav", "padhv");
275$priv{$_}{64} = "REFC" for ("leave", "leavesub", "leavesublv", "leavewrite");
276$priv{"aassign"}{64} = "COMMON";
277$priv{"aassign"}{32} = "PHASH";
278$priv{"sassign"}{64} = "BKWARD";
279$priv{$_}{64} = "RTIME" for ("match", "subst", "substcont");
280@{$priv{"trans"}}{1,2,4,8,16,64} = ("<UTF", ">UTF", "IDENT", "SQUASH", "DEL",
281 "COMPL", "GROWS");
282$priv{"repeat"}{64} = "DOLIST";
283$priv{"leaveloop"}{64} = "CONT";
284@{$priv{$_}}{32,64,96} = ("DREFAV", "DREFHV", "DREFSV")
285 for ("entersub", map("rv2${_}v", "a", "s", "h", "g"), "aelem", "helem");
286$priv{"entersub"}{16} = "DBG";
287$priv{"entersub"}{32} = "TARG";
288@{$priv{$_}}{4,8,128} = ("INARGS","AMPER","NO()") for ("entersub", "rv2cv");
289$priv{"gv"}{32} = "EARLYCV";
290$priv{"aelem"}{16} = $priv{"helem"}{16} = "LVDEFER";
291$priv{$_}{16} = "OURINTR" for ("gvsv", "rv2sv", "rv2av", "rv2hv", "r2gv");
292$priv{$_}{16} = "TARGMY"
293 for (map(($_,"s$_"),"chop", "chomp"),
294 map(($_,"i_$_"), "postinc", "postdec", "multiply", "divide", "modulo",
295 "add", "subtract", "negate"), "pow", "concat", "stringify",
296 "left_shift", "right_shift", "bit_and", "bit_xor", "bit_or",
297 "complement", "atan2", "sin", "cos", "rand", "exp", "log", "sqrt",
298 "int", "hex", "oct", "abs", "length", "index", "rindex", "sprintf",
299 "ord", "chr", "crypt", "quotemeta", "join", "push", "unshift", "flock",
300 "chdir", "chown", "chroot", "unlink", "chmod", "utime", "rename",
301 "link", "symlink", "mkdir", "rmdir", "wait", "waitpid", "system",
302 "exec", "kill", "getppid", "getpgrp", "setpgrp", "getpriority",
303 "setpriority", "time", "sleep");
7a9b44b9 304@{$priv{"const"}}{8,16,32,64,128} = ("STRICT","ENTERED", '$[', "BARE", "WARN");
c99ca59a
SM
305$priv{"flip"}{64} = $priv{"flop"}{64} = "LINENUM";
306$priv{"list"}{64} = "GUESSED";
307$priv{"delete"}{64} = "SLICE";
308$priv{"exists"}{64} = "SUB";
309$priv{$_}{64} = "LOCALE"
310 for ("sort", "prtf", "sprintf", "slt", "sle", "seq", "sne", "sgt", "sge",
311 "scmp", "lc", "uc", "lcfirst", "ucfirst");
312@{$priv{"sort"}}{1,2,4} = ("NUM", "INT", "REV");
313$priv{"threadsv"}{64} = "SVREFd";
314$priv{$_}{16} = "INBIN" for ("open", "backtick");
315$priv{$_}{32} = "INCR" for ("open", "backtick");
316$priv{$_}{64} = "OUTBIN" for ("open", "backtick");
317$priv{$_}{128} = "OUTCR" for ("open", "backtick");
318$priv{"exit"}{128} = "VMS";
319
320sub private_flags {
321 my($name, $x) = @_;
322 my @s;
323 for my $flag (128, 96, 64, 32, 16, 8, 4, 2, 1) {
324 if ($priv{$name}{$flag} and $x & $flag and $x >= $flag) {
325 $x -= $flag;
326 push @s, $priv{$name}{$flag};
327 }
328 }
329 push @s, $x if $x;
330 return join(",", @s);
331}
332
333sub concise_op {
334 my ($op, $level, $format) = @_;
335 my %h;
336 $h{exname} = $h{name} = $op->name;
337 $h{NAME} = uc $h{name};
338 $h{class} = class($op);
339 $h{extarg} = $h{targ} = $op->targ;
340 $h{extarg} = "" unless $h{extarg};
341 if ($h{name} eq "null" and $h{targ}) {
342 $h{exname} = "ex-" . substr(ppname($h{targ}), 3);
343 $h{extarg} = "";
344 } elsif ($h{targ}) {
345 my $padname = (($curcv->PADLIST->ARRAY)[0]->ARRAY)[$h{targ}];
346 if (defined $padname and class($padname) ne "SPECIAL") {
0b40bd6d 347 $h{targarg} = $padname->PVX;
c99ca59a
SM
348 my $intro = $padname->NVX - $cop_seq_base;
349 my $finish = int($padname->IVX) - $cop_seq_base;
350 $finish = "end" if $finish == 999999999 - $cop_seq_base;
351 $h{targarglife} = "$h{targarg}:$intro,$finish";
352 } else {
353 $h{targarglife} = $h{targarg} = "t" . $h{targ};
354 }
355 }
356 $h{arg} = "";
357 $h{svclass} = $h{svaddr} = $h{svval} = "";
358 if ($h{class} eq "PMOP") {
359 my $precomp = $op->precomp;
7a9b44b9
RH
360 if (defined $precomp) {
361 # Escape literal control sequences
362 for ($precomp) {
363 s/\t/\\t/g; s/\n/\\n/g; s/\r/\\r/g;
364 # How can we do the below portably?
365 #s/([\0-\037\177-\377])/"\\".sprintf("%03o", ord($1))/eg;
366 }
367 $precomp = "/$precomp/";
368 }
369 else { $precomp = ""; }
b2a3cfdd 370 my $pmreplroot = $op->pmreplroot;
34a48b4b
RH
371 my $pmreplstart;
372 if ($$pmreplroot && $pmreplroot->isa("B::GV")) {
b2a3cfdd
RH
373 # with C<@stash_array = split(/pat/, str);>,
374 # *stash_array is stored in pmreplroot.
375 $h{arg} = "($precomp => \@" . $pmreplroot->NAME . ")";
376 } elsif ($ {$op->pmreplstart}) {
c99ca59a
SM
377 undef $lastnext;
378 $pmreplstart = "replstart->" . seq($op->pmreplstart);
379 $h{arg} = "(" . join(" ", $precomp, $pmreplstart) . ")";
380 } else {
381 $h{arg} = "($precomp)";
382 }
383 } elsif ($h{class} eq "PVOP" and $h{name} ne "trans") {
384 $h{arg} = '("' . $op->pv . '")';
385 $h{svval} = '"' . $op->pv . '"';
386 } elsif ($h{class} eq "COP") {
387 my $label = $op->label;
c3caa09d 388 $h{coplabel} = $label;
c99ca59a
SM
389 $label = $label ? "$label: " : "";
390 my $loc = $op->file;
391 $loc =~ s[.*/][];
392 $loc .= ":" . $op->line;
393 my($stash, $cseq) = ($op->stash->NAME, $op->cop_seq - $cop_seq_base);
394 my $arybase = $op->arybase;
395 $arybase = $arybase ? ' $[=' . $arybase : "";
396 $h{arg} = "($label$stash $cseq $loc$arybase)";
397 } elsif ($h{class} eq "LOOP") {
398 $h{arg} = "(next->" . seq($op->nextop) . " last->" . seq($op->lastop)
399 . " redo->" . seq($op->redoop) . ")";
400 } elsif ($h{class} eq "LOGOP") {
401 undef $lastnext;
402 $h{arg} = "(other->" . seq($op->other) . ")";
403 } elsif ($h{class} eq "SVOP") {
404 my $sv = $op->sv;
405 $h{svclass} = class($sv);
406 $h{svaddr} = sprintf("%#x", $$sv);
407 if ($h{svclass} eq "GV") {
408 my $gv = $sv;
409 my $stash = $gv->STASH->NAME;
410 if ($stash eq "main") {
411 $stash = "";
412 } else {
413 $stash = $stash . "::";
414 }
002b978b
RH
415 $h{arg} = "(*$stash" . $gv->SAFENAME . ")";
416 $h{svval} = "*$stash" . $gv->SAFENAME;
c99ca59a
SM
417 } else {
418 while (class($sv) eq "RV") {
419 $h{svval} .= "\\";
420 $sv = $sv->RV;
421 }
422 if (class($sv) eq "SPECIAL") {
423 $h{svval} = ["Null", "sv_undef", "sv_yes", "sv_no"]->[$$sv];
424 } elsif ($sv->FLAGS & SVf_NOK) {
425 $h{svval} = $sv->NV;
426 } elsif ($sv->FLAGS & SVf_IOK) {
427 $h{svval} = $sv->IV;
428 } elsif ($sv->FLAGS & SVf_POK) {
429 $h{svval} = cstring($sv->PV);
430 }
431 $h{arg} = "($h{svclass} $h{svval})";
432 }
433 }
434 $h{seq} = $h{hyphseq} = seq($op);
435 $h{seq} = "" if $h{seq} eq "-";
436 $h{seqnum} = $op->seq;
437 $h{next} = $op->next;
438 $h{next} = (class($h{next}) eq "NULL") ? "(end)" : seq($h{next});
439 $h{nextaddr} = sprintf("%#x", $ {$op->next});
440 $h{sibaddr} = sprintf("%#x", $ {$op->sibling});
441 $h{firstaddr} = sprintf("%#x", $ {$op->first}) if $op->can("first");
442 $h{lastaddr} = sprintf("%#x", $ {$op->last}) if $op->can("last");
443
444 $h{classsym} = $opclass{$h{class}};
445 $h{flagval} = $op->flags;
446 $h{flags} = op_flags($op->flags);
447 $h{privval} = $op->private;
448 $h{private} = private_flags($h{name}, $op->private);
449 $h{addr} = sprintf("%#x", $$op);
450 $h{label} = $labels{$op->seq};
451 $h{typenum} = $op->type;
452 $h{noise} = $linenoise[$op->type];
78ad9108 453 $_->(\%h, $op, \$format, \$level) for @callbacks;
c99ca59a
SM
454 return fmt_line(\%h, $format, $level);
455}
456
457sub B::OP::concise {
458 my($op, $level) = @_;
459 if ($order eq "exec" and $lastnext and $$lastnext != $$op) {
460 my $h = {"seq" => seq($lastnext), "class" => class($lastnext),
461 "addr" => sprintf("%#x", $$lastnext)};
462 print fmt_line($h, $gotofmt, $level+1);
463 }
464 $lastnext = $op->next;
465 print concise_op($op, $level, $format);
466}
467
468sub tree {
469 my $op = shift;
470 my $level = shift;
471 my $style = $tree_decorations[$tree_style];
472 my($space, $single, $kids, $kid, $nokid, $last, $lead, $size) = @$style;
473 my $name = concise_op($op, $level, $treefmt);
474 if (not $op->flags & OPf_KIDS) {
475 return $name . "\n";
476 }
477 my @lines;
478 for (my $kid = $op->first; $$kid; $kid = $kid->sibling) {
479 push @lines, tree($kid, $level+1);
480 }
481 my $i;
482 for ($i = $#lines; substr($lines[$i], 0, 1) eq " "; $i--) {
483 $lines[$i] = $space . $lines[$i];
484 }
485 if ($i > 0) {
486 $lines[$i] = $last . $lines[$i];
487 while ($i-- > 1) {
488 if (substr($lines[$i], 0, 1) eq " ") {
489 $lines[$i] = $nokid . $lines[$i];
490 } else {
491 $lines[$i] = $kid . $lines[$i];
492 }
493 }
494 $lines[$i] = $kids . $lines[$i];
495 } else {
496 $lines[0] = $single . $lines[0];
497 }
498 return("$name$lead" . shift @lines,
499 map(" " x (length($name)+$size) . $_, @lines));
500}
501
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502# *** Warning: fragile kludge ahead ***
503# Because the B::* modules run in the same interpreter as the code
504# they're compiling, their presence tends to distort the view we have
505# of the code we're looking at. In particular, perl gives sequence
506# numbers to both OPs in general and COPs in particular. If the
507# program we're looking at were run on its own, these numbers would
508# start at 1. Because all of B::Concise and all the modules it uses
509# are compiled first, though, by the time we get to the user's program
510# the sequence numbers are alreay at pretty high numbers, which would
511# be distracting if you're trying to tell OPs apart. Therefore we'd
512# like to subtract an offset from all the sequence numbers we display,
513# to restore the simpler view of the world. The trick is to know what
514# that offset will be, when we're still compiling B::Concise! If we
515# hardcoded a value, it would have to change every time B::Concise or
516# other modules we use do. To help a little, what we do here is
517# compile a little code at the end of the module, and compute the base
518# sequence number for the user's program as being a small offset
519# later, so all we have to worry about are changes in the offset.
520
521# When you say "perl -MO=Concise -e '$a'", the output should look like:
522
523# 4 <@> leave[t1] vKP/REFC ->(end)
524# 1 <0> enter ->2
525 #^ smallest OP sequence number should be 1
526# 2 <;> nextstate(main 1 -e:1) v ->3
527 # ^ smallest COP sequence number should be 1
528# - <1> ex-rv2sv vK/1 ->4
529# 3 <$> gvsv(*a) s ->4
530
531# If either of the marked numbers there aren't 1, it means you need to
532# update the corresponding magic number in the next two lines.
533# Reember, these need to stay the last things in the module.
534$cop_seq_base = svref_2object(eval 'sub{0;}')->START->cop_seq + 11;
535$seq_base = svref_2object(eval 'sub{}')->START->seq + 84;
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536
5371;
538
539__END__
540
541=head1 NAME
542
543B::Concise - Walk Perl syntax tree, printing concise info about ops
544
545=head1 SYNOPSIS
546
547 perl -MO=Concise[,OPTIONS] foo.pl
548
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549 use B::Concise qw(set_style add_callback);
550
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551=head1 DESCRIPTION
552
553This compiler backend prints the internal OPs of a Perl program's syntax
554tree in one of several space-efficient text formats suitable for debugging
555the inner workings of perl or other compiler backends. It can print OPs in
556the order they appear in the OP tree, in the order they will execute, or
557in a text approximation to their tree structure, and the format of the
558information displyed is customizable. Its function is similar to that of
559perl's B<-Dx> debugging flag or the B<B::Terse> module, but it is more
560sophisticated and flexible.
561
562=head1 OPTIONS
563
564Arguments that don't start with a hyphen are taken to be the names of
565subroutines to print the OPs of; if no such functions are specified, the
566main body of the program (outside any subroutines, and not including use'd
567or require'd files) is printed.
568
569=over 4
570
571=item B<-basic>
572
573Print OPs in the order they appear in the OP tree (a preorder
574traversal, starting at the root). The indentation of each OP shows its
575level in the tree. This mode is the default, so the flag is included
576simply for completeness.
577
578=item B<-exec>
579
580Print OPs in the order they would normally execute (for the majority
581of constructs this is a postorder traversal of the tree, ending at the
582root). In most cases the OP that usually follows a given OP will
583appear directly below it; alternate paths are shown by indentation. In
584cases like loops when control jumps out of a linear path, a 'goto'
585line is generated.
586
587=item B<-tree>
588
589Print OPs in a text approximation of a tree, with the root of the tree
590at the left and 'left-to-right' order of children transformed into
591'top-to-bottom'. Because this mode grows both to the right and down,
592it isn't suitable for large programs (unless you have a very wide
593terminal).
594
595=item B<-compact>
596
597Use a tree format in which the minimum amount of space is used for the
598lines connecting nodes (one character in most cases). This squeezes out
599a few precious columns of screen real estate.
600
601=item B<-loose>
602
603Use a tree format that uses longer edges to separate OP nodes. This format
604tends to look better than the compact one, especially in ASCII, and is
605the default.
606
607=item B<-vt>
608
609Use tree connecting characters drawn from the VT100 line-drawing set.
610This looks better if your terminal supports it.
611
612=item B<-ascii>
613
614Draw the tree with standard ASCII characters like C<+> and C<|>. These don't
615look as clean as the VT100 characters, but they'll work with almost any
616terminal (or the horizontal scrolling mode of less(1)) and are suitable
617for text documentation or email. This is the default.
618
619=item B<-main>
620
621Include the main program in the output, even if subroutines were also
622specified.
623
624=item B<-base>I<n>
625
626Print OP sequence numbers in base I<n>. If I<n> is greater than 10, the
627digit for 11 will be 'a', and so on. If I<n> is greater than 36, the digit
628for 37 will be 'A', and so on until 62. Values greater than 62 are not
629currently supported. The default is 36.
630
631=item B<-bigendian>
632
633Print sequence numbers with the most significant digit first. This is the
634usual convention for Arabic numerals, and the default.
635
636=item B<-littleendian>
637
638Print seqence numbers with the least significant digit first.
639
640=item B<-concise>
641
642Use the author's favorite set of formatting conventions. This is the
643default, of course.
644
645=item B<-terse>
646
647Use formatting conventions that emulate the ouput of B<B::Terse>. The
648basic mode is almost indistinguishable from the real B<B::Terse>, and the
649exec mode looks very similar, but is in a more logical order and lacks
650curly brackets. B<B::Terse> doesn't have a tree mode, so the tree mode
651is only vaguely reminiscient of B<B::Terse>.
652
653=item B<-linenoise>
654
655Use formatting conventions in which the name of each OP, rather than being
656written out in full, is represented by a one- or two-character abbreviation.
657This is mainly a joke.
658
659=item B<-debug>
660
661Use formatting conventions reminiscient of B<B::Debug>; these aren't
662very concise at all.
663
664=item B<-env>
665
666Use formatting conventions read from the environment variables
667C<B_CONCISE_FORMAT>, C<B_CONCISE_GOTO_FORMAT>, and C<B_CONCISE_TREE_FORMAT>.
668
669=back
670
671=head1 FORMATTING SPECIFICATIONS
672
673For each general style ('concise', 'terse', 'linenoise', etc.) there are
674three specifications: one of how OPs should appear in the basic or exec
675modes, one of how 'goto' lines should appear (these occur in the exec
676mode only), and one of how nodes should appear in tree mode. Each has the
677same format, described below. Any text that doesn't match a special
678pattern is copied verbatim.
679
680=over 4
681
682=item B<(x(>I<exec_text>B<;>I<basic_text>B<)x)>
683
684Generates I<exec_text> in exec mode, or I<basic_text> in basic mode.
685
686=item B<(*(>I<text>B<)*)>
687
688Generates one copy of I<text> for each indentation level.
689
690=item B<(*(>I<text1>B<;>I<text2>B<)*)>
691
692Generates one fewer copies of I<text1> than the indentation level, followed
693by one copy of I<text2> if the indentation level is more than 0.
694
695=item B<(?(>I<text1>B<#>I<var>I<Text2>B<)?)>
696
697If the value of I<var> is true (not empty or zero), generates the
698value of I<var> surrounded by I<text1> and I<Text2>, otherwise
699nothing.
700
701=item B<#>I<var>
702
703Generates the value of the variable I<var>.
704
705=item B<#>I<var>I<N>
706
707Generates the value of I<var>, left jutified to fill I<N> spaces.
708
709=item B<~>
710
711Any number of tildes and surrounding whitespace will be collapsed to
712a single space.
713
714=back
715
716The following variables are recognized:
717
718=over 4
719
720=item B<#addr>
721
722The address of the OP, in hexidecimal.
723
724=item B<#arg>
725
726The OP-specific information of the OP (such as the SV for an SVOP, the
727non-local exit pointers for a LOOP, etc.) enclosed in paretheses.
728
729=item B<#class>
730
731The B-determined class of the OP, in all caps.
732
733=item B<#classym>
734
735A single symbol abbreviating the class of the OP.
736
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737=item B<#coplabel>
738
739The label of the statement or block the OP is the start of, if any.
740
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741=item B<#exname>
742
743The name of the OP, or 'ex-foo' if the OP is a null that used to be a foo.
744
745=item B<#extarg>
746
747The target of the OP, or nothing for a nulled OP.
748
749=item B<#firstaddr>
750
751The address of the OP's first child, in hexidecimal.
752
753=item B<#flags>
754
755The OP's flags, abbreviated as a series of symbols.
756
757=item B<#flagval>
758
759The numeric value of the OP's flags.
760
761=item B<#hyphenseq>
762
763The sequence number of the OP, or a hyphen if it doesn't have one.
764
765=item B<#label>
766
767'NEXT', 'LAST', or 'REDO' if the OP is a target of one of those in exec
768mode, or empty otherwise.
769
770=item B<#lastaddr>
771
772The address of the OP's last child, in hexidecimal.
773
774=item B<#name>
775
776The OP's name.
777
778=item B<#NAME>
779
780The OP's name, in all caps.
781
782=item B<#next>
783
784The sequence number of the OP's next OP.
785
786=item B<#nextaddr>
787
788The address of the OP's next OP, in hexidecimal.
789
790=item B<#noise>
791
792The two-character abbreviation for the OP's name.
793
794=item B<#private>
795
796The OP's private flags, rendered with abbreviated names if possible.
797
798=item B<#privval>
799
800The numeric value of the OP's private flags.
801
802=item B<#seq>
803
804The sequence number of the OP.
805
806=item B<#seqnum>
807
808The real sequence number of the OP, as a regular number and not adjusted
809to be relative to the start of the real program. (This will generally be
810a fairly large number because all of B<B::Concise> is compiled before
811your program is).
812
813=item B<#sibaddr>
814
815The address of the OP's next youngest sibling, in hexidecimal.
816
817=item B<#svaddr>
818
819The address of the OP's SV, if it has an SV, in hexidecimal.
820
821=item B<#svclass>
822
823The class of the OP's SV, if it has one, in all caps (e.g., 'IV').
824
825=item B<#svval>
826
827The value of the OP's SV, if it has one, in a short human-readable format.
828
829=item B<#targ>
830
831The numeric value of the OP's targ.
832
833=item B<#targarg>
834
835The name of the variable the OP's targ refers to, if any, otherwise the
836letter t followed by the OP's targ in decimal.
837
838=item B<#targarglife>
839
840Same as B<#targarg>, but followed by the COP sequence numbers that delimit
841the variable's lifetime (or 'end' for a variable in an open scope) for a
842variable.
843
844=item B<#typenum>
845
846The numeric value of the OP's type, in decimal.
847
848=back
849
850=head1 ABBREVIATIONS
851
852=head2 OP flags abbreviations
853
854 v OPf_WANT_VOID Want nothing (void context)
855 s OPf_WANT_SCALAR Want single value (scalar context)
856 l OPf_WANT_LIST Want list of any length (list context)
857 K OPf_KIDS There is a firstborn child.
858 P OPf_PARENS This operator was parenthesized.
859 (Or block needs explicit scope entry.)
860 R OPf_REF Certified reference.
861 (Return container, not containee).
862 M OPf_MOD Will modify (lvalue).
863 S OPf_STACKED Some arg is arriving on the stack.
864 * OPf_SPECIAL Do something weird for this op (see op.h)
865
866=head2 OP class abbreviations
867
868 0 OP (aka BASEOP) An OP with no children
869 1 UNOP An OP with one child
870 2 BINOP An OP with two children
871 | LOGOP A control branch OP
872 @ LISTOP An OP that could have lots of children
873 / PMOP An OP with a regular expression
874 $ SVOP An OP with an SV
875 " PVOP An OP with a string
876 { LOOP An OP that holds pointers for a loop
877 ; COP An OP that marks the start of a statement
051f02e9 878 # PADOP An OP with a GV on the pad
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880=head1 Using B::Concise outside of the O framework
881
882It is possible to extend B<B::Concise> by using it outside of the B<O>
883framework and providing new styles and new variables.
884
885 use B::Concise qw(set_style add_callback);
886 set_style($format, $gotofmt, $treefmt);
887 add_callback
888 (
889 sub
890 {
891 my ($h, $op, $level, $format) = @_;
892 $h->{variable} = some_func($op);
893 }
894 );
895 B::Concise::compile(@options)->();
896
897You can specify a style by calling the B<set_style> subroutine. If you
898have a new variable in your style, or you want to change the value of an
899existing variable, you will need to add a callback to specify the value
900for that variable.
901
902This is done by calling B<add_callback> passing references to any
903callback subroutines. The subroutines are called in the same order as
904they are added. Each subroutine is passed four parameters. These are a
905reference to a hash, the keys of which are the names of the variables
906and the values of which are their values, the op, the level and the
907format.
908
909To define your own variables, simply add them to the hash, or change
910existing values if you need to. The level and format are passed in as
911references to scalars, but it is unlikely that they will need to be
912changed or even used.
913
914To see the output, call the subroutine returned by B<compile> in the
915same way that B<O> does.
916
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917=head1 AUTHOR
918
919Stephen McCamant, C<smcc@CSUA.Berkeley.EDU>
920
921=cut