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1 | package B::Concise; |
2 | # Copyright (C) 2000-2003 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 | ||
6 | # Note: we need to keep track of how many use declarations/BEGIN | |
7 | # blocks this module uses, so we can avoid printing them when user | |
8 | # asks for the BEGIN blocks in her program. Update the comments and | |
9 | # the count in concise_specials if you add or delete one. The | |
10 | # -MO=Concise counts as use #1. | |
11 | ||
12 | use strict; # use #2 | |
13 | use warnings; # uses #3 and #4, since warnings uses Carp | |
14 | ||
15 | use Exporter (); # use #5 | |
16 | ||
17 | our $VERSION = "0.66"; | |
18 | our @ISA = qw(Exporter); | |
19 | our @EXPORT_OK = qw( set_style set_style_standard add_callback | |
20 | concise_subref concise_cv concise_main | |
21 | add_style walk_output compile reset_sequence ); | |
22 | our %EXPORT_TAGS = | |
23 | ( io => [qw( walk_output compile reset_sequence )], | |
24 | style => [qw( add_style set_style_standard )], | |
25 | cb => [qw( add_callback )], | |
26 | mech => [qw( concise_subref concise_cv concise_main )], ); | |
27 | ||
28 | # use #6 | |
29 | use B qw(class ppname main_start main_root main_cv cstring svref_2object | |
30 | SVf_IOK SVf_NOK SVf_POK SVf_IVisUV SVf_FAKE OPf_KIDS OPf_SPECIAL | |
31 | CVf_ANON); | |
32 | ||
33 | my %style = | |
34 | ("terse" => | |
35 | ["(?(#label =>\n)?)(*( )*)#class (#addr) #name (?([#targ])?) " | |
36 | . "#svclass~(?((#svaddr))?)~#svval~(?(label \"#coplabel\")?)\n", | |
37 | "(*( )*)goto #class (#addr)\n", | |
38 | "#class pp_#name"], | |
39 | "concise" => | |
40 | ["#hyphseq2 (*( (x( ;)x))*)<#classsym> " | |
41 | . "#exname#arg(?([#targarglife])?)~#flags(?(/#private)?)(x(;~->#next)x)\n" | |
42 | , " (*( )*) goto #seq\n", | |
43 | "(?(<#seq>)?)#exname#arg(?([#targarglife])?)"], | |
44 | "linenoise" => | |
45 | ["(x(;(*( )*))x)#noise#arg(?([#targarg])?)(x( ;\n)x)", | |
46 | "gt_#seq ", | |
47 | "(?(#seq)?)#noise#arg(?([#targarg])?)"], | |
48 | "debug" => | |
49 | ["#class (#addr)\n\top_next\t\t#nextaddr\n\top_sibling\t#sibaddr\n\t" | |
50 | . "op_ppaddr\tPL_ppaddr[OP_#NAME]\n\top_type\t\t#typenum\n" . | |
51 | ($] > 5.009 ? '' : "\top_seq\t\t#seqnum\n") | |
52 | . "\top_flags\t#flagval\n\top_private\t#privval\n" | |
53 | . "(?(\top_first\t#firstaddr\n)?)(?(\top_last\t\t#lastaddr\n)?)" | |
54 | . "(?(\top_sv\t\t#svaddr\n)?)", | |
55 | " GOTO #addr\n", | |
56 | "#addr"], | |
57 | "env" => [$ENV{B_CONCISE_FORMAT}, $ENV{B_CONCISE_GOTO_FORMAT}, | |
58 | $ENV{B_CONCISE_TREE_FORMAT}], | |
59 | ); | |
60 | ||
61 | # Renderings, ie how Concise prints, is controlled by these vars | |
62 | # primary: | |
63 | our $stylename; # selects current style from %style | |
64 | my $order = "basic"; # how optree is walked & printed: basic, exec, tree | |
65 | ||
66 | # rendering mechanics: | |
67 | # these 'formats' are the line-rendering templates | |
68 | # they're updated from %style when $stylename changes | |
69 | my ($format, $gotofmt, $treefmt); | |
70 | ||
71 | # lesser players: | |
72 | my $base = 36; # how <sequence#> is displayed | |
73 | my $big_endian = 1; # more <sequence#> display | |
74 | my $tree_style = 0; # tree-order details | |
75 | my $banner = 1; # print banner before optree is traversed | |
76 | my $do_main = 0; # force printing of main routine | |
77 | ||
78 | # another factor: can affect all styles! | |
79 | our @callbacks; # allow external management | |
80 | ||
81 | set_style_standard("concise"); | |
82 | ||
83 | my $curcv; | |
84 | my $cop_seq_base; | |
85 | ||
86 | sub set_style { | |
87 | ($format, $gotofmt, $treefmt) = @_; | |
88 | #warn "set_style: deprecated, use set_style_standard instead\n"; # someday | |
89 | die "expecting 3 style-format args\n" unless @_ == 3; | |
90 | } | |
91 | ||
92 | sub add_style { | |
93 | my ($newstyle,@args) = @_; | |
94 | die "style '$newstyle' already exists, choose a new name\n" | |
95 | if exists $style{$newstyle}; | |
96 | die "expecting 3 style-format args\n" unless @args == 3; | |
97 | $style{$newstyle} = [@args]; | |
98 | $stylename = $newstyle; # update rendering state | |
99 | } | |
100 | ||
101 | sub set_style_standard { | |
102 | ($stylename) = @_; # update rendering state | |
103 | die "err: style '$stylename' unknown\n" unless exists $style{$stylename}; | |
104 | set_style(@{$style{$stylename}}); | |
105 | } | |
106 | ||
107 | sub add_callback { | |
108 | push @callbacks, @_; | |
109 | } | |
110 | ||
111 | # output handle, used with all Concise-output printing | |
112 | our $walkHandle; # public for your convenience | |
113 | BEGIN { $walkHandle = \*STDOUT } | |
114 | ||
115 | sub walk_output { # updates $walkHandle | |
116 | my $handle = shift; | |
117 | return $walkHandle unless $handle; # allow use as accessor | |
118 | ||
119 | if (ref $handle eq 'SCALAR') { | |
120 | require Config; | |
121 | die "no perlio in this build, can't call walk_output (\\\$scalar)\n" | |
122 | unless $Config::Config{useperlio}; | |
123 | # in 5.8+, open(FILEHANDLE,MODE,REFERENCE) writes to string | |
124 | open my $tmp, '>', $handle; # but cant re-set existing STDOUT | |
125 | $walkHandle = $tmp; # so use my $tmp as intermediate var | |
126 | return $walkHandle; | |
127 | } | |
128 | my $iotype = ref $handle; | |
129 | die "expecting argument/object that can print\n" | |
130 | unless $iotype eq 'GLOB' or $iotype and $handle->can('print'); | |
131 | $walkHandle = $handle; | |
132 | } | |
133 | ||
134 | sub concise_subref { | |
135 | my($order, $coderef, $name) = @_; | |
136 | my $codeobj = svref_2object($coderef); | |
137 | ||
138 | return concise_stashref(@_) | |
139 | unless ref $codeobj eq 'B::CV'; | |
140 | concise_cv_obj($order, $codeobj, $name); | |
141 | } | |
142 | ||
143 | sub concise_stashref { | |
144 | my($order, $h) = @_; | |
145 | foreach my $k (sort keys %$h) { | |
146 | local *s = $h->{$k}; | |
147 | my $coderef = *s{CODE} or next; | |
148 | reset_sequence(); | |
149 | print "FUNC: ", *s, "\n"; | |
150 | my $codeobj = svref_2object($coderef); | |
151 | next unless ref $codeobj eq 'B::CV'; | |
152 | eval { concise_cv_obj($order, $codeobj) } | |
153 | or warn "err $@ on $codeobj"; | |
154 | } | |
155 | } | |
156 | ||
157 | # This should have been called concise_subref, but it was exported | |
158 | # under this name in versions before 0.56 | |
159 | *concise_cv = \&concise_subref; | |
160 | ||
161 | sub concise_cv_obj { | |
162 | my ($order, $cv, $name) = @_; | |
163 | # name is either a string, or a CODE ref (copy of $cv arg??) | |
164 | ||
165 | $curcv = $cv; | |
166 | if ($cv->XSUB) { | |
167 | print $walkHandle "$name is XS code\n"; | |
168 | return; | |
169 | } | |
170 | if (class($cv->START) eq "NULL") { | |
171 | no strict 'refs'; | |
172 | if (ref $name eq 'CODE') { | |
173 | print $walkHandle "coderef $name has no START\n"; | |
174 | } | |
175 | elsif (exists &$name) { | |
176 | print $walkHandle "$name exists in stash, but has no START\n"; | |
177 | } | |
178 | else { | |
179 | print $walkHandle "$name not in symbol table\n"; | |
180 | } | |
181 | return; | |
182 | } | |
183 | sequence($cv->START); | |
184 | if ($order eq "exec") { | |
185 | walk_exec($cv->START); | |
186 | } | |
187 | elsif ($order eq "basic") { | |
188 | # walk_topdown($cv->ROOT, sub { $_[0]->concise($_[1]) }, 0); | |
189 | my $root = $cv->ROOT; | |
190 | unless (ref $root eq 'B::NULL') { | |
191 | walk_topdown($root, sub { $_[0]->concise($_[1]) }, 0); | |
192 | } else { | |
193 | print $walkHandle "B::NULL encountered doing ROOT on $cv. avoiding disaster\n"; | |
194 | } | |
195 | } else { | |
196 | print $walkHandle tree($cv->ROOT, 0); | |
197 | } | |
198 | } | |
199 | ||
200 | sub concise_main { | |
201 | my($order) = @_; | |
202 | sequence(main_start); | |
203 | $curcv = main_cv; | |
204 | if ($order eq "exec") { | |
205 | return if class(main_start) eq "NULL"; | |
206 | walk_exec(main_start); | |
207 | } elsif ($order eq "tree") { | |
208 | return if class(main_root) eq "NULL"; | |
209 | print $walkHandle tree(main_root, 0); | |
210 | } elsif ($order eq "basic") { | |
211 | return if class(main_root) eq "NULL"; | |
212 | walk_topdown(main_root, | |
213 | sub { $_[0]->concise($_[1]) }, 0); | |
214 | } | |
215 | } | |
216 | ||
217 | sub concise_specials { | |
218 | my($name, $order, @cv_s) = @_; | |
219 | my $i = 1; | |
220 | if ($name eq "BEGIN") { | |
221 | splice(@cv_s, 0, 8); # skip 7 BEGIN blocks in this file. NOW 8 ?? | |
222 | } elsif ($name eq "CHECK") { | |
223 | pop @cv_s; # skip the CHECK block that calls us | |
224 | } | |
225 | for my $cv (@cv_s) { | |
226 | print $walkHandle "$name $i:\n"; | |
227 | $i++; | |
228 | concise_cv_obj($order, $cv, $name); | |
229 | } | |
230 | } | |
231 | ||
232 | my $start_sym = "\e(0"; # "\cN" sometimes also works | |
233 | my $end_sym = "\e(B"; # "\cO" respectively | |
234 | ||
235 | my @tree_decorations = | |
236 | ([" ", "--", "+-", "|-", "| ", "`-", "-", 1], | |
237 | [" ", "-", "+", "+", "|", "`", "", 0], | |
238 | [" ", map("$start_sym$_$end_sym", "qq", "wq", "tq", "x ", "mq", "q"), 1], | |
239 | [" ", map("$start_sym$_$end_sym", "q", "w", "t", "x", "m"), "", 0], | |
240 | ); | |
241 | ||
242 | ||
243 | sub compileOpts { | |
244 | # set rendering state from options and args | |
245 | my (@options,@args); | |
246 | if (@_) { | |
247 | @options = grep(/^-/, @_); | |
248 | @args = grep(!/^-/, @_); | |
249 | } | |
250 | for my $o (@options) { | |
251 | # mode/order | |
252 | if ($o eq "-basic") { | |
253 | $order = "basic"; | |
254 | } elsif ($o eq "-exec") { | |
255 | $order = "exec"; | |
256 | } elsif ($o eq "-tree") { | |
257 | $order = "tree"; | |
258 | } | |
259 | # tree-specific | |
260 | elsif ($o eq "-compact") { | |
261 | $tree_style |= 1; | |
262 | } elsif ($o eq "-loose") { | |
263 | $tree_style &= ~1; | |
264 | } elsif ($o eq "-vt") { | |
265 | $tree_style |= 2; | |
266 | } elsif ($o eq "-ascii") { | |
267 | $tree_style &= ~2; | |
268 | } | |
269 | # sequence numbering | |
270 | elsif ($o =~ /^-base(\d+)$/) { | |
271 | $base = $1; | |
272 | } elsif ($o eq "-bigendian") { | |
273 | $big_endian = 1; | |
274 | } elsif ($o eq "-littleendian") { | |
275 | $big_endian = 0; | |
276 | } | |
277 | elsif ($o eq "-nobanner") { | |
278 | $banner = 0; | |
279 | } elsif ($o eq "-banner") { | |
280 | $banner = 1; | |
281 | } | |
282 | elsif ($o eq "-main") { | |
283 | $do_main = 1; | |
284 | } elsif ($o eq "-nomain") { | |
285 | $do_main = 0; | |
286 | } | |
287 | # line-style options | |
288 | elsif (exists $style{substr($o, 1)}) { | |
289 | $stylename = substr($o, 1); | |
290 | set_style_standard($stylename); | |
291 | } else { | |
292 | warn "Option $o unrecognized"; | |
293 | } | |
294 | } | |
295 | return (@args); | |
296 | } | |
297 | ||
298 | sub compile { | |
299 | my (@args) = compileOpts(@_); | |
300 | return sub { | |
301 | my @newargs = compileOpts(@_); # accept new rendering options | |
302 | warn "disregarding non-options: @newargs\n" if @newargs; | |
303 | ||
304 | for my $objname (@args) { | |
305 | next unless $objname; # skip null args to avoid noisy responses | |
306 | ||
307 | if ($objname eq "BEGIN") { | |
308 | concise_specials("BEGIN", $order, | |
309 | B::begin_av->isa("B::AV") ? | |
310 | B::begin_av->ARRAY : ()); | |
311 | } elsif ($objname eq "INIT") { | |
312 | concise_specials("INIT", $order, | |
313 | B::init_av->isa("B::AV") ? | |
314 | B::init_av->ARRAY : ()); | |
315 | } elsif ($objname eq "CHECK") { | |
316 | concise_specials("CHECK", $order, | |
317 | B::check_av->isa("B::AV") ? | |
318 | B::check_av->ARRAY : ()); | |
319 | } elsif ($objname eq "END") { | |
320 | concise_specials("END", $order, | |
321 | B::end_av->isa("B::AV") ? | |
322 | B::end_av->ARRAY : ()); | |
323 | } | |
324 | else { | |
325 | # convert function names to subrefs | |
326 | my $objref; | |
327 | if (ref $objname) { | |
328 | print $walkHandle "B::Concise::compile($objname)\n" | |
329 | if $banner; | |
330 | $objref = $objname; | |
331 | } else { | |
332 | $objname = "main::" . $objname unless $objname =~ /::/; | |
333 | print $walkHandle "$objname:\n"; | |
334 | no strict 'refs'; | |
335 | unless (exists &$objname) { | |
336 | print $walkHandle "err: unknown function ($objname)\n"; | |
337 | return; | |
338 | } | |
339 | $objref = \&$objname; | |
340 | } | |
341 | concise_subref($order, $objref, $objname); | |
342 | } | |
343 | } | |
344 | if (!@args or $do_main) { | |
345 | print $walkHandle "main program:\n" if $do_main; | |
346 | concise_main($order); | |
347 | } | |
348 | return @args; # something | |
349 | } | |
350 | } | |
351 | ||
352 | my %labels; | |
353 | my $lastnext; # remembers op-chain, used to insert gotos | |
354 | ||
355 | my %opclass = ('OP' => "0", 'UNOP' => "1", 'BINOP' => "2", 'LOGOP' => "|", | |
356 | 'LISTOP' => "@", 'PMOP' => "/", 'SVOP' => "\$", 'GVOP' => "*", | |
357 | 'PVOP' => '"', 'LOOP' => "{", 'COP' => ";", 'PADOP' => "#"); | |
358 | ||
359 | no warnings 'qw'; # "Possible attempt to put comments..."; use #7 | |
360 | my @linenoise = | |
361 | qw'# () sc ( @? 1 $* gv *{ m$ m@ m% m? p/ *$ $ $# & a& pt \\ s\\ rf bl | |
362 | ` *? <> ?? ?/ r/ c/ // qr s/ /c y/ = @= C sC Cp sp df un BM po +1 +I | |
363 | -1 -I 1+ I+ 1- I- ** * i* / i/ %$ i% x + i+ - i- . " << >> < i< | |
364 | > i> <= i, >= i. == i= != i! <? i? s< s> s, s. s= s! s? b& b^ b| -0 -i | |
365 | ! ~ a2 si cs rd sr e^ lg sq in %x %o ab le ss ve ix ri sf FL od ch cy | |
366 | uf lf uc lc qm @ [f [ @[ eh vl ky dl ex % ${ @{ uk pk st jn ) )[ a@ | |
367 | a% sl +] -] [- [+ so rv GS GW MS MW .. f. .f && || ^^ ?: &= |= -> s{ s} | |
368 | v} ca wa di rs ;; ; ;d }{ { } {} f{ it {l l} rt }l }n }r dm }g }e ^o | |
369 | ^c ^| ^# um bm t~ u~ ~d DB db ^s se ^g ^r {w }w pf pr ^O ^K ^R ^W ^d ^v | |
370 | ^e ^t ^k t. fc ic fl .s .p .b .c .l .a .h g1 s1 g2 s2 ?. l? -R -W -X -r | |
371 | -w -x -e -o -O -z -s -M -A -C -S -c -b -f -d -p -l -u -g -k -t -T -B cd | |
372 | co cr u. cm ut r. l@ s@ r@ mD uD oD rD tD sD wD cD f$ w$ p$ sh e$ k$ g3 | |
373 | g4 s4 g5 s5 T@ C@ L@ G@ A@ S@ Hg Hc Hr Hw Mg Mc Ms Mr Sg Sc So rq do {e | |
374 | e} {t t} g6 G6 6e g7 G7 7e g8 G8 8e g9 G9 9e 6s 7s 8s 9s 6E 7E 8E 9E Pn | |
375 | Pu GP SP EP Gn Gg GG SG EG g0 c$ lk t$ ;s n> // /= CO'; | |
376 | ||
377 | my $chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"; | |
378 | ||
379 | sub op_flags { # common flags (see BASOP.op_flags in op.h) | |
380 | my($x) = @_; | |
381 | my(@v); | |
382 | push @v, "v" if ($x & 3) == 1; | |
383 | push @v, "s" if ($x & 3) == 2; | |
384 | push @v, "l" if ($x & 3) == 3; | |
385 | push @v, "K" if $x & 4; | |
386 | push @v, "P" if $x & 8; | |
387 | push @v, "R" if $x & 16; | |
388 | push @v, "M" if $x & 32; | |
389 | push @v, "S" if $x & 64; | |
390 | push @v, "*" if $x & 128; | |
391 | return join("", @v); | |
392 | } | |
393 | ||
394 | sub base_n { | |
395 | my $x = shift; | |
396 | return "-" . base_n(-$x) if $x < 0; | |
397 | my $str = ""; | |
398 | do { $str .= substr($chars, $x % $base, 1) } while $x = int($x / $base); | |
399 | $str = reverse $str if $big_endian; | |
400 | return $str; | |
401 | } | |
402 | ||
403 | my %sequence_num; | |
404 | my $seq_max = 1; | |
405 | ||
406 | sub reset_sequence { | |
407 | # reset the sequence | |
408 | %sequence_num = (); | |
409 | $seq_max = 1; | |
410 | $lastnext = 0; | |
411 | } | |
412 | ||
413 | sub seq { | |
414 | my($op) = @_; | |
415 | return "-" if not exists $sequence_num{$$op}; | |
416 | return base_n($sequence_num{$$op}); | |
417 | } | |
418 | ||
419 | sub walk_topdown { | |
420 | my($op, $sub, $level) = @_; | |
421 | $sub->($op, $level); | |
422 | if ($op->flags & OPf_KIDS) { | |
423 | for (my $kid = $op->first; $$kid; $kid = $kid->sibling) { | |
424 | walk_topdown($kid, $sub, $level + 1); | |
425 | } | |
426 | } | |
427 | elsif (class($op) eq "PMOP") { | |
428 | my $maybe_root = $op->pmreplroot; | |
429 | if (ref($maybe_root) and $maybe_root->isa("B::OP")) { | |
430 | # It really is the root of the replacement, not something | |
431 | # else stored here for lack of space elsewhere | |
432 | walk_topdown($maybe_root, $sub, $level + 1); | |
433 | } | |
434 | } | |
435 | } | |
436 | ||
437 | sub walklines { | |
438 | my($ar, $level) = @_; | |
439 | for my $l (@$ar) { | |
440 | if (ref($l) eq "ARRAY") { | |
441 | walklines($l, $level + 1); | |
442 | } else { | |
443 | $l->concise($level); | |
444 | } | |
445 | } | |
446 | } | |
447 | ||
448 | sub walk_exec { | |
449 | my($top, $level) = @_; | |
450 | my %opsseen; | |
451 | my @lines; | |
452 | my @todo = ([$top, \@lines]); | |
453 | while (@todo and my($op, $targ) = @{shift @todo}) { | |
454 | for (; $$op; $op = $op->next) { | |
455 | last if $opsseen{$$op}++; | |
456 | push @$targ, $op; | |
457 | my $name = $op->name; | |
458 | if (class($op) eq "LOGOP") { | |
459 | my $ar = []; | |
460 | push @$targ, $ar; | |
461 | push @todo, [$op->other, $ar]; | |
462 | } elsif ($name eq "subst" and $ {$op->pmreplstart}) { | |
463 | my $ar = []; | |
464 | push @$targ, $ar; | |
465 | push @todo, [$op->pmreplstart, $ar]; | |
466 | } elsif ($name =~ /^enter(loop|iter)$/) { | |
467 | if ($] > 5.009) { | |
468 | $labels{${$op->nextop}} = "NEXT"; | |
469 | $labels{${$op->lastop}} = "LAST"; | |
470 | $labels{${$op->redoop}} = "REDO"; | |
471 | } else { | |
472 | $labels{$op->nextop->seq} = "NEXT"; | |
473 | $labels{$op->lastop->seq} = "LAST"; | |
474 | $labels{$op->redoop->seq} = "REDO"; | |
475 | } | |
476 | } | |
477 | } | |
478 | } | |
479 | walklines(\@lines, 0); | |
480 | } | |
481 | ||
482 | # The structure of this routine is purposely modeled after op.c's peep() | |
483 | sub sequence { | |
484 | my($op) = @_; | |
485 | my $oldop = 0; | |
486 | return if class($op) eq "NULL" or exists $sequence_num{$$op}; | |
487 | for (; $$op; $op = $op->next) { | |
488 | last if exists $sequence_num{$$op}; | |
489 | my $name = $op->name; | |
490 | if ($name =~ /^(null|scalar|lineseq|scope)$/) { | |
491 | next if $oldop and $ {$op->next}; | |
492 | } else { | |
493 | $sequence_num{$$op} = $seq_max++; | |
494 | if (class($op) eq "LOGOP") { | |
495 | my $other = $op->other; | |
496 | $other = $other->next while $other->name eq "null"; | |
497 | sequence($other); | |
498 | } elsif (class($op) eq "LOOP") { | |
499 | my $redoop = $op->redoop; | |
500 | $redoop = $redoop->next while $redoop->name eq "null"; | |
501 | sequence($redoop); | |
502 | my $nextop = $op->nextop; | |
503 | $nextop = $nextop->next while $nextop->name eq "null"; | |
504 | sequence($nextop); | |
505 | my $lastop = $op->lastop; | |
506 | $lastop = $lastop->next while $lastop->name eq "null"; | |
507 | sequence($lastop); | |
508 | } elsif ($name eq "subst" and $ {$op->pmreplstart}) { | |
509 | my $replstart = $op->pmreplstart; | |
510 | $replstart = $replstart->next while $replstart->name eq "null"; | |
511 | sequence($replstart); | |
512 | } | |
513 | } | |
514 | $oldop = $op; | |
515 | } | |
516 | } | |
517 | ||
518 | sub fmt_line { # generate text-line for op. | |
519 | my($hr, $op, $text, $level) = @_; | |
520 | ||
521 | $_->($hr, $op, \$text, \$level, $stylename) for @callbacks; | |
522 | ||
523 | return '' if $hr->{SKIP}; # suppress line if a callback said so | |
524 | return '' if $hr->{goto} and $hr->{goto} eq '-'; # no goto nowhere | |
525 | ||
526 | # spec: (?(text1#varText2)?) | |
527 | $text =~ s/\(\?\(([^\#]*?)\#(\w+)([^\#]*?)\)\?\)/ | |
528 | $hr->{$2} ? $1.$hr->{$2}.$3 : ""/eg; | |
529 | ||
530 | # spec: (x(exec_text;basic_text)x) | |
531 | $text =~ s/\(x\((.*?);(.*?)\)x\)/$order eq "exec" ? $1 : $2/egs; | |
532 | ||
533 | # spec: (*(text)*) | |
534 | $text =~ s/\(\*\(([^;]*?)\)\*\)/$1 x $level/egs; | |
535 | ||
536 | # spec: (*(text1;text2)*) | |
537 | $text =~ s/\(\*\((.*?);(.*?)\)\*\)/$1 x ($level - 1) . $2 x ($level>0)/egs; | |
538 | ||
539 | # convert #Var to tag=>val form: Var\t#var | |
540 | $text =~ s/\#([A-Z][a-z]+)(\d+)?/\t\u$1\t\L#$1$2/gs; | |
541 | ||
542 | # spec: #varN | |
543 | $text =~ s/\#([a-zA-Z]+)(\d+)/sprintf("%-$2s", $hr->{$1})/eg; | |
544 | ||
545 | $text =~ s/\#([a-zA-Z]+)/$hr->{$1}/eg; # populate #var's | |
546 | $text =~ s/[ \t]*~+[ \t]*/ /g; # squeeze tildes | |
547 | chomp $text; | |
548 | return "$text\n" if $text ne ""; | |
549 | return $text; # suppress empty lines | |
550 | } | |
551 | ||
552 | our %priv; # used to display each opcode's BASEOP.op_private values | |
553 | ||
554 | $priv{$_}{128} = "LVINTRO" | |
555 | for ("pos", "substr", "vec", "threadsv", "gvsv", "rv2sv", "rv2hv", "rv2gv", | |
556 | "rv2av", "rv2arylen", "aelem", "helem", "aslice", "hslice", "padsv", | |
557 | "padav", "padhv", "enteriter"); | |
558 | $priv{$_}{64} = "REFC" for ("leave", "leavesub", "leavesublv", "leavewrite"); | |
559 | $priv{"aassign"}{64} = "COMMON"; | |
560 | $priv{"aassign"}{32} = "PHASH" if $] < 5.009; | |
561 | $priv{"sassign"}{64} = "BKWARD"; | |
562 | $priv{$_}{64} = "RTIME" for ("match", "subst", "substcont", "qr"); | |
563 | @{$priv{"trans"}}{1,2,4,8,16,64} = ("<UTF", ">UTF", "IDENT", "SQUASH", "DEL", | |
564 | "COMPL", "GROWS"); | |
565 | $priv{"repeat"}{64} = "DOLIST"; | |
566 | $priv{"leaveloop"}{64} = "CONT"; | |
567 | @{$priv{$_}}{32,64,96} = ("DREFAV", "DREFHV", "DREFSV") | |
568 | for (qw(rv2gv rv2sv padsv aelem helem)); | |
569 | @{$priv{"entersub"}}{16,32,64} = ("DBG","TARG","NOMOD"); | |
570 | @{$priv{$_}}{4,8,128} = ("INARGS","AMPER","NO()") for ("entersub", "rv2cv"); | |
571 | $priv{"gv"}{32} = "EARLYCV"; | |
572 | $priv{"aelem"}{16} = $priv{"helem"}{16} = "LVDEFER"; | |
573 | $priv{$_}{16} = "OURINTR" for ("gvsv", "rv2sv", "rv2av", "rv2hv", "r2gv", | |
574 | "enteriter"); | |
575 | $priv{$_}{16} = "TARGMY" | |
576 | for (map(($_,"s$_"),"chop", "chomp"), | |
577 | map(($_,"i_$_"), "postinc", "postdec", "multiply", "divide", "modulo", | |
578 | "add", "subtract", "negate"), "pow", "concat", "stringify", | |
579 | "left_shift", "right_shift", "bit_and", "bit_xor", "bit_or", | |
580 | "complement", "atan2", "sin", "cos", "rand", "exp", "log", "sqrt", | |
581 | "int", "hex", "oct", "abs", "length", "index", "rindex", "sprintf", | |
582 | "ord", "chr", "crypt", "quotemeta", "join", "push", "unshift", "flock", | |
583 | "chdir", "chown", "chroot", "unlink", "chmod", "utime", "rename", | |
584 | "link", "symlink", "mkdir", "rmdir", "wait", "waitpid", "system", | |
585 | "exec", "kill", "getppid", "getpgrp", "setpgrp", "getpriority", | |
586 | "setpriority", "time", "sleep"); | |
587 | $priv{$_}{4} = "REVERSED" for ("enteriter", "iter"); | |
588 | @{$priv{"const"}}{4,8,16,32,64,128} = ("SHORT","STRICT","ENTERED",'$[',"BARE","WARN"); | |
589 | $priv{"flip"}{64} = $priv{"flop"}{64} = "LINENUM"; | |
590 | $priv{"list"}{64} = "GUESSED"; | |
591 | $priv{"delete"}{64} = "SLICE"; | |
592 | $priv{"exists"}{64} = "SUB"; | |
593 | $priv{$_}{64} = "LOCALE" | |
594 | for ("sort", "prtf", "sprintf", "slt", "sle", "seq", "sne", "sgt", "sge", | |
595 | "scmp", "lc", "uc", "lcfirst", "ucfirst"); | |
596 | @{$priv{"sort"}}{1,2,4,8,16} = ("NUM", "INT", "REV", "INPLACE","DESC"); | |
597 | $priv{"threadsv"}{64} = "SVREFd"; | |
598 | @{$priv{$_}}{16,32,64,128} = ("INBIN","INCR","OUTBIN","OUTCR") | |
599 | for ("open", "backtick"); | |
600 | $priv{"exit"}{128} = "VMS"; | |
601 | $priv{$_}{2} = "FTACCESS" | |
602 | for ("ftrread", "ftrwrite", "ftrexec", "fteread", "ftewrite", "fteexec"); | |
603 | if ($] >= 5.009) { | |
604 | # Stacked filetests are post 5.8.x | |
605 | $priv{$_}{4} = "FTSTACKED" | |
606 | for ("ftrread", "ftrwrite", "ftrexec", "fteread", "ftewrite", "fteexec", | |
607 | "ftis", "fteowned", "ftrowned", "ftzero", "ftsize", "ftmtime", | |
608 | "ftatime", "ftctime", "ftsock", "ftchr", "ftblk", "ftfile", "ftdir", | |
609 | "ftpipe", "ftlink", "ftsuid", "ftsgid", "ftsvtx", "fttty", "fttext", | |
610 | "ftbinary"); | |
611 | # Lexical $_ is post 5.8.x | |
612 | $priv{$_}{2} = "GREPLEX" | |
613 | for ("mapwhile", "mapstart", "grepwhile", "grepstart"); | |
614 | } | |
615 | ||
616 | sub private_flags { | |
617 | my($name, $x) = @_; | |
618 | my @s; | |
619 | for my $flag (128, 96, 64, 32, 16, 8, 4, 2, 1) { | |
620 | if ($priv{$name}{$flag} and $x & $flag and $x >= $flag) { | |
621 | $x -= $flag; | |
622 | push @s, $priv{$name}{$flag}; | |
623 | } | |
624 | } | |
625 | push @s, $x if $x; | |
626 | return join(",", @s); | |
627 | } | |
628 | ||
629 | sub concise_sv { | |
630 | my($sv, $hr, $preferpv) = @_; | |
631 | $hr->{svclass} = class($sv); | |
632 | $hr->{svclass} = "UV" | |
633 | if $hr->{svclass} eq "IV" and $sv->FLAGS & SVf_IVisUV; | |
634 | Carp::cluck("bad concise_sv: $sv") unless $sv and $$sv; | |
635 | $hr->{svaddr} = sprintf("%#x", $$sv); | |
636 | if ($hr->{svclass} eq "GV") { | |
637 | my $gv = $sv; | |
638 | my $stash = $gv->STASH->NAME; | |
639 | if ($stash eq "main") { | |
640 | $stash = ""; | |
641 | } else { | |
642 | $stash = $stash . "::"; | |
643 | } | |
644 | $hr->{svval} = "*$stash" . $gv->SAFENAME; | |
645 | return "*$stash" . $gv->SAFENAME; | |
646 | } else { | |
647 | while (class($sv) eq "RV") { | |
648 | $hr->{svval} .= "\\"; | |
649 | $sv = $sv->RV; | |
650 | } | |
651 | if (class($sv) eq "SPECIAL") { | |
652 | $hr->{svval} .= ["Null", "sv_undef", "sv_yes", "sv_no"]->[$$sv]; | |
653 | } elsif ($preferpv && $sv->FLAGS & SVf_POK) { | |
654 | $hr->{svval} .= cstring($sv->PV); | |
655 | } elsif ($sv->FLAGS & SVf_NOK) { | |
656 | $hr->{svval} .= $sv->NV; | |
657 | } elsif ($sv->FLAGS & SVf_IOK) { | |
658 | $hr->{svval} .= $sv->int_value; | |
659 | } elsif ($sv->FLAGS & SVf_POK) { | |
660 | $hr->{svval} .= cstring($sv->PV); | |
661 | } elsif (class($sv) eq "HV") { | |
662 | $hr->{svval} .= 'HASH'; | |
663 | } | |
664 | ||
665 | $hr->{svval} = 'undef' unless defined $hr->{svval}; | |
666 | my $out = $hr->{svclass}; | |
667 | return $out .= " $hr->{svval}" ; | |
668 | } | |
669 | } | |
670 | ||
671 | sub concise_op { | |
672 | my ($op, $level, $format) = @_; | |
673 | my %h; | |
674 | $h{exname} = $h{name} = $op->name; | |
675 | $h{NAME} = uc $h{name}; | |
676 | $h{class} = class($op); | |
677 | $h{extarg} = $h{targ} = $op->targ; | |
678 | $h{extarg} = "" unless $h{extarg}; | |
679 | if ($h{name} eq "null" and $h{targ}) { | |
680 | # targ holds the old type | |
681 | $h{exname} = "ex-" . substr(ppname($h{targ}), 3); | |
682 | $h{extarg} = ""; | |
683 | } elsif ($op->name =~ /^leave(sub(lv)?|write)?$/) { | |
684 | # targ potentially holds a reference count | |
685 | if ($op->private & 64) { | |
686 | my $refs = "ref" . ($h{targ} != 1 ? "s" : ""); | |
687 | $h{targarglife} = $h{targarg} = "$h{targ} $refs"; | |
688 | } | |
689 | } elsif ($h{targ}) { | |
690 | my $padname = (($curcv->PADLIST->ARRAY)[0]->ARRAY)[$h{targ}]; | |
691 | if (defined $padname and class($padname) ne "SPECIAL") { | |
692 | $h{targarg} = $padname->PVX; | |
693 | if ($padname->FLAGS & SVf_FAKE) { | |
694 | if ($] < 5.009) { | |
695 | $h{targarglife} = "$h{targarg}:FAKE"; | |
696 | } else { | |
697 | # These changes relate to the jumbo closure fix. | |
698 | # See changes 19939 and 20005 | |
699 | my $fake = ''; | |
700 | $fake .= 'a' if $padname->IVX & 1; # PAD_FAKELEX_ANON | |
701 | $fake .= 'm' if $padname->IVX & 2; # PAD_FAKELEX_MULTI | |
702 | $fake .= ':' . $padname->NVX if $curcv->CvFLAGS & CVf_ANON; | |
703 | $h{targarglife} = "$h{targarg}:FAKE:$fake"; | |
704 | } | |
705 | } | |
706 | else { | |
707 | my $intro = $padname->NVX - $cop_seq_base; | |
708 | my $finish = int($padname->IVX) - $cop_seq_base; | |
709 | $finish = "end" if $finish == 999999999 - $cop_seq_base; | |
710 | $h{targarglife} = "$h{targarg}:$intro,$finish"; | |
711 | } | |
712 | } else { | |
713 | $h{targarglife} = $h{targarg} = "t" . $h{targ}; | |
714 | } | |
715 | } | |
716 | $h{arg} = ""; | |
717 | $h{svclass} = $h{svaddr} = $h{svval} = ""; | |
718 | if ($h{class} eq "PMOP") { | |
719 | my $precomp = $op->precomp; | |
720 | if (defined $precomp) { | |
721 | $precomp = cstring($precomp); # Escape literal control sequences | |
722 | $precomp = "/$precomp/"; | |
723 | } else { | |
724 | $precomp = ""; | |
725 | } | |
726 | my $pmreplroot = $op->pmreplroot; | |
727 | my $pmreplstart; | |
728 | if (ref($pmreplroot) eq "B::GV") { | |
729 | # with C<@stash_array = split(/pat/, str);>, | |
730 | # *stash_array is stored in /pat/'s pmreplroot. | |
731 | $h{arg} = "($precomp => \@" . $pmreplroot->NAME . ")"; | |
732 | } elsif (!ref($pmreplroot) and $pmreplroot) { | |
733 | # same as the last case, except the value is actually a | |
734 | # pad offset for where the GV is kept (this happens under | |
735 | # ithreads) | |
736 | my $gv = (($curcv->PADLIST->ARRAY)[1]->ARRAY)[$pmreplroot]; | |
737 | $h{arg} = "($precomp => \@" . $gv->NAME . ")"; | |
738 | } elsif ($ {$op->pmreplstart}) { | |
739 | undef $lastnext; | |
740 | $pmreplstart = "replstart->" . seq($op->pmreplstart); | |
741 | $h{arg} = "(" . join(" ", $precomp, $pmreplstart) . ")"; | |
742 | } else { | |
743 | $h{arg} = "($precomp)"; | |
744 | } | |
745 | } elsif ($h{class} eq "PVOP" and $h{name} ne "trans") { | |
746 | $h{arg} = '("' . $op->pv . '")'; | |
747 | $h{svval} = '"' . $op->pv . '"'; | |
748 | } elsif ($h{class} eq "COP") { | |
749 | my $label = $op->label; | |
750 | $h{coplabel} = $label; | |
751 | $label = $label ? "$label: " : ""; | |
752 | my $loc = $op->file; | |
753 | $loc =~ s[.*/][]; | |
754 | $loc .= ":" . $op->line; | |
755 | my($stash, $cseq) = ($op->stash->NAME, $op->cop_seq - $cop_seq_base); | |
756 | my $arybase = $op->arybase; | |
757 | $arybase = $arybase ? ' $[=' . $arybase : ""; | |
758 | $h{arg} = "($label$stash $cseq $loc$arybase)"; | |
759 | } elsif ($h{class} eq "LOOP") { | |
760 | $h{arg} = "(next->" . seq($op->nextop) . " last->" . seq($op->lastop) | |
761 | . " redo->" . seq($op->redoop) . ")"; | |
762 | } elsif ($h{class} eq "LOGOP") { | |
763 | undef $lastnext; | |
764 | $h{arg} = "(other->" . seq($op->other) . ")"; | |
765 | } | |
766 | elsif ($h{class} eq "SVOP" or $h{class} eq "PADOP") { | |
767 | unless ($h{name} eq 'aelemfast' and $op->flags & OPf_SPECIAL) { | |
768 | my $idx = ($h{class} eq "SVOP") ? $op->targ : $op->padix; | |
769 | my $preferpv = $h{name} eq "method_named"; | |
770 | if ($h{class} eq "PADOP" or !${$op->sv}) { | |
771 | my $sv = (($curcv->PADLIST->ARRAY)[1]->ARRAY)[$idx]; | |
772 | $h{arg} = "[" . concise_sv($sv, \%h, $preferpv) . "]"; | |
773 | $h{targarglife} = $h{targarg} = ""; | |
774 | } else { | |
775 | $h{arg} = "(" . concise_sv($op->sv, \%h, $preferpv) . ")"; | |
776 | } | |
777 | } | |
778 | } | |
779 | $h{seq} = $h{hyphseq} = seq($op); | |
780 | $h{seq} = "" if $h{seq} eq "-"; | |
781 | if ($] > 5.009) { | |
782 | $h{opt} = $op->opt; | |
783 | $h{static} = $op->static; | |
784 | $h{label} = $labels{$$op}; | |
785 | } else { | |
786 | $h{seqnum} = $op->seq; | |
787 | $h{label} = $labels{$op->seq}; | |
788 | } | |
789 | $h{next} = $op->next; | |
790 | $h{next} = (class($h{next}) eq "NULL") ? "(end)" : seq($h{next}); | |
791 | $h{nextaddr} = sprintf("%#x", $ {$op->next}); | |
792 | $h{sibaddr} = sprintf("%#x", $ {$op->sibling}); | |
793 | $h{firstaddr} = sprintf("%#x", $ {$op->first}) if $op->can("first"); | |
794 | $h{lastaddr} = sprintf("%#x", $ {$op->last}) if $op->can("last"); | |
795 | ||
796 | $h{classsym} = $opclass{$h{class}}; | |
797 | $h{flagval} = $op->flags; | |
798 | $h{flags} = op_flags($op->flags); | |
799 | $h{privval} = $op->private; | |
800 | $h{private} = private_flags($h{name}, $op->private); | |
801 | $h{addr} = sprintf("%#x", $$op); | |
802 | $h{typenum} = $op->type; | |
803 | $h{noise} = $linenoise[$op->type]; | |
804 | ||
805 | return fmt_line(\%h, $op, $format, $level); | |
806 | } | |
807 | ||
808 | sub B::OP::concise { | |
809 | my($op, $level) = @_; | |
810 | if ($order eq "exec" and $lastnext and $$lastnext != $$op) { | |
811 | # insert a 'goto' line | |
812 | my $synth = {"seq" => seq($lastnext), "class" => class($lastnext), | |
813 | "addr" => sprintf("%#x", $$lastnext), | |
814 | "goto" => seq($lastnext), # simplify goto '-' removal | |
815 | }; | |
816 | print $walkHandle fmt_line($synth, $op, $gotofmt, $level+1); | |
817 | } | |
818 | $lastnext = $op->next; | |
819 | print $walkHandle concise_op($op, $level, $format); | |
820 | } | |
821 | ||
822 | # B::OP::terse (see Terse.pm) now just calls this | |
823 | sub b_terse { | |
824 | my($op, $level) = @_; | |
825 | ||
826 | # This isn't necessarily right, but there's no easy way to get | |
827 | # from an OP to the right CV. This is a limitation of the | |
828 | # ->terse() interface style, and there isn't much to do about | |
829 | # it. In particular, we can die in concise_op if the main pad | |
830 | # isn't long enough, or has the wrong kind of entries, compared to | |
831 | # the pad a sub was compiled with. The fix for that would be to | |
832 | # make a backwards compatible "terse" format that never even | |
833 | # looked at the pad, just like the old B::Terse. I don't think | |
834 | # that's worth the effort, though. | |
835 | $curcv = main_cv unless $curcv; | |
836 | ||
837 | if ($order eq "exec" and $lastnext and $$lastnext != $$op) { | |
838 | # insert a 'goto' | |
839 | my $h = {"seq" => seq($lastnext), "class" => class($lastnext), | |
840 | "addr" => sprintf("%#x", $$lastnext)}; | |
841 | print # $walkHandle | |
842 | fmt_line($h, $op, $style{"terse"}[1], $level+1); | |
843 | } | |
844 | $lastnext = $op->next; | |
845 | print # $walkHandle | |
846 | concise_op($op, $level, $style{"terse"}[0]); | |
847 | } | |
848 | ||
849 | sub tree { | |
850 | my $op = shift; | |
851 | my $level = shift; | |
852 | my $style = $tree_decorations[$tree_style]; | |
853 | my($space, $single, $kids, $kid, $nokid, $last, $lead, $size) = @$style; | |
854 | my $name = concise_op($op, $level, $treefmt); | |
855 | if (not $op->flags & OPf_KIDS) { | |
856 | return $name . "\n"; | |
857 | } | |
858 | my @lines; | |
859 | for (my $kid = $op->first; $$kid; $kid = $kid->sibling) { | |
860 | push @lines, tree($kid, $level+1); | |
861 | } | |
862 | my $i; | |
863 | for ($i = $#lines; substr($lines[$i], 0, 1) eq " "; $i--) { | |
864 | $lines[$i] = $space . $lines[$i]; | |
865 | } | |
866 | if ($i > 0) { | |
867 | $lines[$i] = $last . $lines[$i]; | |
868 | while ($i-- > 1) { | |
869 | if (substr($lines[$i], 0, 1) eq " ") { | |
870 | $lines[$i] = $nokid . $lines[$i]; | |
871 | } else { | |
872 | $lines[$i] = $kid . $lines[$i]; | |
873 | } | |
874 | } | |
875 | $lines[$i] = $kids . $lines[$i]; | |
876 | } else { | |
877 | $lines[0] = $single . $lines[0]; | |
878 | } | |
879 | return("$name$lead" . shift @lines, | |
880 | map(" " x (length($name)+$size) . $_, @lines)); | |
881 | } | |
882 | ||
883 | # *** Warning: fragile kludge ahead *** | |
884 | # Because the B::* modules run in the same interpreter as the code | |
885 | # they're compiling, their presence tends to distort the view we have of | |
886 | # the code we're looking at. In particular, perl gives sequence numbers | |
887 | # to COPs. If the program we're looking at were run on its own, this | |
888 | # would start at 1. Because all of B::Concise and all the modules it | |
889 | # uses are compiled first, though, by the time we get to the user's | |
890 | # program the sequence number is already pretty high, which could be | |
891 | # distracting if you're trying to tell OPs apart. Therefore we'd like to | |
892 | # subtract an offset from all the sequence numbers we display, to | |
893 | # restore the simpler view of the world. The trick is to know what that | |
894 | # offset will be, when we're still compiling B::Concise! If we | |
895 | # hardcoded a value, it would have to change every time B::Concise or | |
896 | # other modules we use do. To help a little, what we do here is compile | |
897 | # a little code at the end of the module, and compute the base sequence | |
898 | # number for the user's program as being a small offset later, so all we | |
899 | # have to worry about are changes in the offset. | |
900 | ||
901 | # [For 5.8.x and earlier perl is generating sequence numbers for all ops, | |
902 | # and using them to reference labels] | |
903 | ||
904 | ||
905 | # When you say "perl -MO=Concise -e '$a'", the output should look like: | |
906 | ||
907 | # 4 <@> leave[t1] vKP/REFC ->(end) | |
908 | # 1 <0> enter ->2 | |
909 | #^ smallest OP sequence number should be 1 | |
910 | # 2 <;> nextstate(main 1 -e:1) v ->3 | |
911 | # ^ smallest COP sequence number should be 1 | |
912 | # - <1> ex-rv2sv vK/1 ->4 | |
913 | # 3 <$> gvsv(*a) s ->4 | |
914 | ||
915 | # If the second of the marked numbers there isn't 1, it means you need | |
916 | # to update the corresponding magic number in the next line. | |
917 | # Remember, this needs to stay the last things in the module. | |
918 | ||
919 | # Why is this different for MacOS? Does it matter? | |
920 | my $cop_seq_mnum = $^O eq 'MacOS' ? 12 : 11; | |
921 | $cop_seq_base = svref_2object(eval 'sub{0;}')->START->cop_seq + $cop_seq_mnum; | |
922 | ||
923 | 1; | |
924 | ||
925 | __END__ | |
926 | ||
927 | =head1 NAME | |
928 | ||
929 | B::Concise - Walk Perl syntax tree, printing concise info about ops | |
930 | ||
931 | =head1 SYNOPSIS | |
932 | ||
933 | perl -MO=Concise[,OPTIONS] foo.pl | |
934 | ||
935 | use B::Concise qw(set_style add_callback); | |
936 | ||
937 | =head1 DESCRIPTION | |
938 | ||
939 | This compiler backend prints the internal OPs of a Perl program's syntax | |
940 | tree in one of several space-efficient text formats suitable for debugging | |
941 | the inner workings of perl or other compiler backends. It can print OPs in | |
942 | the order they appear in the OP tree, in the order they will execute, or | |
943 | in a text approximation to their tree structure, and the format of the | |
944 | information displayed is customizable. Its function is similar to that of | |
945 | perl's B<-Dx> debugging flag or the B<B::Terse> module, but it is more | |
946 | sophisticated and flexible. | |
947 | ||
948 | =head1 EXAMPLE | |
949 | ||
950 | Here's an example of 2 outputs (aka 'renderings'), using the | |
951 | -exec and -basic (i.e. default) formatting conventions on the same code | |
952 | snippet. | |
953 | ||
954 | % perl -MO=Concise,-exec -e '$a = $b + 42' | |
955 | 1 <0> enter | |
956 | 2 <;> nextstate(main 1 -e:1) v | |
957 | 3 <#> gvsv[*b] s | |
958 | 4 <$> const[IV 42] s | |
959 | * 5 <2> add[t3] sK/2 | |
960 | 6 <#> gvsv[*a] s | |
961 | 7 <2> sassign vKS/2 | |
962 | 8 <@> leave[1 ref] vKP/REFC | |
963 | ||
964 | Each line corresponds to an opcode. The opcode marked with '*' is used | |
965 | in a few examples below. | |
966 | ||
967 | The 1st column is the op's sequence number, starting at 1, and is | |
968 | displayed in base 36 by default. This rendering is in -exec (i.e. | |
969 | execution) order. | |
970 | ||
971 | The symbol between angle brackets indicates the op's type, for | |
972 | example; <2> is a BINOP, <@> a LISTOP, and <#> is a PADOP, which is | |
973 | used in threaded perls. (see L</"OP class abbreviations">). | |
974 | ||
975 | The opname, as in B<'add[t1]'>, which may be followed by op-specific | |
976 | information in parentheses or brackets (ex B<'[t1]'>). | |
977 | ||
978 | The op-flags (ex B<'sK/2'>) follow, and are described in (L</"OP flags | |
979 | abbreviations">). | |
980 | ||
981 | % perl -MO=Concise -e '$a = $b + 42' | |
982 | 8 <@> leave[1 ref] vKP/REFC ->(end) | |
983 | 1 <0> enter ->2 | |
984 | 2 <;> nextstate(main 1 -e:1) v ->3 | |
985 | 7 <2> sassign vKS/2 ->8 | |
986 | * 5 <2> add[t1] sK/2 ->6 | |
987 | - <1> ex-rv2sv sK/1 ->4 | |
988 | 3 <$> gvsv(*b) s ->4 | |
989 | 4 <$> const(IV 42) s ->5 | |
990 | - <1> ex-rv2sv sKRM*/1 ->7 | |
991 | 6 <$> gvsv(*a) s ->7 | |
992 | ||
993 | The default rendering is top-down, so they're not in execution order. | |
994 | This form reflects the way the stack is used to parse and evaluate | |
995 | expressions; the add operates on the two terms below it in the tree. | |
996 | ||
997 | Nullops appear as C<ex-opname>, where I<opname> is an op that has been | |
998 | optimized away by perl. They're displayed with a sequence-number of | |
999 | '-', because they are not executed (they don't appear in previous | |
1000 | example), they're printed here because they reflect the parse. | |
1001 | ||
1002 | The arrow points to the sequence number of the next op; they're not | |
1003 | displayed in -exec mode, for obvious reasons. | |
1004 | ||
1005 | Note that because this rendering was done on a non-threaded perl, the | |
1006 | PADOPs in the previous examples are now SVOPs, and some (but not all) | |
1007 | of the square brackets have been replaced by round ones. This is a | |
1008 | subtle feature to provide some visual distinction between renderings | |
1009 | on threaded and un-threaded perls. | |
1010 | ||
1011 | ||
1012 | =head1 OPTIONS | |
1013 | ||
1014 | Arguments that don't start with a hyphen are taken to be the names of | |
1015 | subroutines to print the OPs of; if no such functions are specified, | |
1016 | the main body of the program (outside any subroutines, and not | |
1017 | including use'd or require'd files) is rendered. Passing C<BEGIN>, | |
1018 | C<CHECK>, C<INIT>, or C<END> will cause all of the corresponding | |
1019 | special blocks to be printed. | |
1020 | ||
1021 | Options affect how things are rendered (ie printed). They're presented | |
1022 | here by their visual effect, 1st being strongest. They're grouped | |
1023 | according to how they interrelate; within each group the options are | |
1024 | mutually exclusive (unless otherwise stated). | |
1025 | ||
1026 | =head2 Options for Opcode Ordering | |
1027 | ||
1028 | These options control the 'vertical display' of opcodes. The display | |
1029 | 'order' is also called 'mode' elsewhere in this document. | |
1030 | ||
1031 | =over 4 | |
1032 | ||
1033 | =item B<-basic> | |
1034 | ||
1035 | Print OPs in the order they appear in the OP tree (a preorder | |
1036 | traversal, starting at the root). The indentation of each OP shows its | |
1037 | level in the tree, and the '->' at the end of the line indicates the | |
1038 | next opcode in execution order. This mode is the default, so the flag | |
1039 | is included simply for completeness. | |
1040 | ||
1041 | =item B<-exec> | |
1042 | ||
1043 | Print OPs in the order they would normally execute (for the majority | |
1044 | of constructs this is a postorder traversal of the tree, ending at the | |
1045 | root). In most cases the OP that usually follows a given OP will | |
1046 | appear directly below it; alternate paths are shown by indentation. In | |
1047 | cases like loops when control jumps out of a linear path, a 'goto' | |
1048 | line is generated. | |
1049 | ||
1050 | =item B<-tree> | |
1051 | ||
1052 | Print OPs in a text approximation of a tree, with the root of the tree | |
1053 | at the left and 'left-to-right' order of children transformed into | |
1054 | 'top-to-bottom'. Because this mode grows both to the right and down, | |
1055 | it isn't suitable for large programs (unless you have a very wide | |
1056 | terminal). | |
1057 | ||
1058 | =back | |
1059 | ||
1060 | =head2 Options for Line-Style | |
1061 | ||
1062 | These options select the line-style (or just style) used to render | |
1063 | each opcode, and dictates what info is actually printed into each line. | |
1064 | ||
1065 | =over 4 | |
1066 | ||
1067 | =item B<-concise> | |
1068 | ||
1069 | Use the author's favorite set of formatting conventions. This is the | |
1070 | default, of course. | |
1071 | ||
1072 | =item B<-terse> | |
1073 | ||
1074 | Use formatting conventions that emulate the output of B<B::Terse>. The | |
1075 | basic mode is almost indistinguishable from the real B<B::Terse>, and the | |
1076 | exec mode looks very similar, but is in a more logical order and lacks | |
1077 | curly brackets. B<B::Terse> doesn't have a tree mode, so the tree mode | |
1078 | is only vaguely reminiscent of B<B::Terse>. | |
1079 | ||
1080 | =item B<-linenoise> | |
1081 | ||
1082 | Use formatting conventions in which the name of each OP, rather than being | |
1083 | written out in full, is represented by a one- or two-character abbreviation. | |
1084 | This is mainly a joke. | |
1085 | ||
1086 | =item B<-debug> | |
1087 | ||
1088 | Use formatting conventions reminiscent of B<B::Debug>; these aren't | |
1089 | very concise at all. | |
1090 | ||
1091 | =item B<-env> | |
1092 | ||
1093 | Use formatting conventions read from the environment variables | |
1094 | C<B_CONCISE_FORMAT>, C<B_CONCISE_GOTO_FORMAT>, and C<B_CONCISE_TREE_FORMAT>. | |
1095 | ||
1096 | =back | |
1097 | ||
1098 | =head2 Options for tree-specific formatting | |
1099 | ||
1100 | =over 4 | |
1101 | ||
1102 | =item B<-compact> | |
1103 | ||
1104 | Use a tree format in which the minimum amount of space is used for the | |
1105 | lines connecting nodes (one character in most cases). This squeezes out | |
1106 | a few precious columns of screen real estate. | |
1107 | ||
1108 | =item B<-loose> | |
1109 | ||
1110 | Use a tree format that uses longer edges to separate OP nodes. This format | |
1111 | tends to look better than the compact one, especially in ASCII, and is | |
1112 | the default. | |
1113 | ||
1114 | =item B<-vt> | |
1115 | ||
1116 | Use tree connecting characters drawn from the VT100 line-drawing set. | |
1117 | This looks better if your terminal supports it. | |
1118 | ||
1119 | =item B<-ascii> | |
1120 | ||
1121 | Draw the tree with standard ASCII characters like C<+> and C<|>. These don't | |
1122 | look as clean as the VT100 characters, but they'll work with almost any | |
1123 | terminal (or the horizontal scrolling mode of less(1)) and are suitable | |
1124 | for text documentation or email. This is the default. | |
1125 | ||
1126 | =back | |
1127 | ||
1128 | These are pairwise exclusive, i.e. compact or loose, vt or ascii. | |
1129 | ||
1130 | =head2 Options controlling sequence numbering | |
1131 | ||
1132 | =over 4 | |
1133 | ||
1134 | =item B<-base>I<n> | |
1135 | ||
1136 | Print OP sequence numbers in base I<n>. If I<n> is greater than 10, the | |
1137 | digit for 11 will be 'a', and so on. If I<n> is greater than 36, the digit | |
1138 | for 37 will be 'A', and so on until 62. Values greater than 62 are not | |
1139 | currently supported. The default is 36. | |
1140 | ||
1141 | =item B<-bigendian> | |
1142 | ||
1143 | Print sequence numbers with the most significant digit first. This is the | |
1144 | usual convention for Arabic numerals, and the default. | |
1145 | ||
1146 | =item B<-littleendian> | |
1147 | ||
1148 | Print seqence numbers with the least significant digit first. This is | |
1149 | obviously mutually exclusive with bigendian. | |
1150 | ||
1151 | =back | |
1152 | ||
1153 | =head2 Other options | |
1154 | ||
1155 | These are pairwise exclusive. | |
1156 | ||
1157 | =over 4 | |
1158 | ||
1159 | =item B<-main> | |
1160 | ||
1161 | Include the main program in the output, even if subroutines were also | |
1162 | specified. This rendering is normally suppressed when a subroutine | |
1163 | name or reference is given. | |
1164 | ||
1165 | =item B<-nomain> | |
1166 | ||
1167 | This restores the default behavior after you've changed it with '-main' | |
1168 | (it's not normally needed). If no subroutine name/ref is given, main is | |
1169 | rendered, regardless of this flag. | |
1170 | ||
1171 | =item B<-nobanner> | |
1172 | ||
1173 | Renderings usually include a banner line identifying the function name | |
1174 | or stringified subref. This suppresses the printing of the banner. | |
1175 | ||
1176 | TBC: Remove the stringified coderef; while it provides a 'cookie' for | |
1177 | each function rendered, the cookies used should be 1,2,3.. not a | |
1178 | random hex-address. It also complicates string comparison of two | |
1179 | different trees. | |
1180 | ||
1181 | =item B<-banner> | |
1182 | ||
1183 | restores default banner behavior. | |
1184 | ||
1185 | =item B<-banneris> => subref | |
1186 | ||
1187 | TBC: a hookpoint (and an option to set it) for a user-supplied | |
1188 | function to produce a banner appropriate for users needs. It's not | |
1189 | ideal, because the rendering-state variables, which are a natural | |
1190 | candidate for use in concise.t, are unavailable to the user. | |
1191 | ||
1192 | =back | |
1193 | ||
1194 | =head2 Option Stickiness | |
1195 | ||
1196 | If you invoke Concise more than once in a program, you should know that | |
1197 | the options are 'sticky'. This means that the options you provide in | |
1198 | the first call will be remembered for the 2nd call, unless you | |
1199 | re-specify or change them. | |
1200 | ||
1201 | =head1 ABBREVIATIONS | |
1202 | ||
1203 | The concise style uses symbols to convey maximum info with minimal | |
1204 | clutter (like hex addresses). With just a little practice, you can | |
1205 | start to see the flowers, not just the branches, in the trees. | |
1206 | ||
1207 | =head2 OP class abbreviations | |
1208 | ||
1209 | These symbols appear before the op-name, and indicate the | |
1210 | B:: namespace that represents the ops in your Perl code. | |
1211 | ||
1212 | 0 OP (aka BASEOP) An OP with no children | |
1213 | 1 UNOP An OP with one child | |
1214 | 2 BINOP An OP with two children | |
1215 | | LOGOP A control branch OP | |
1216 | @ LISTOP An OP that could have lots of children | |
1217 | / PMOP An OP with a regular expression | |
1218 | $ SVOP An OP with an SV | |
1219 | " PVOP An OP with a string | |
1220 | { LOOP An OP that holds pointers for a loop | |
1221 | ; COP An OP that marks the start of a statement | |
1222 | # PADOP An OP with a GV on the pad | |
1223 | ||
1224 | =head2 OP flags abbreviations | |
1225 | ||
1226 | OP flags are either public or private. The public flags alter the | |
1227 | behavior of each opcode in consistent ways, and are represented by 0 | |
1228 | or more single characters. | |
1229 | ||
1230 | v OPf_WANT_VOID Want nothing (void context) | |
1231 | s OPf_WANT_SCALAR Want single value (scalar context) | |
1232 | l OPf_WANT_LIST Want list of any length (list context) | |
1233 | Want is unknown | |
1234 | K OPf_KIDS There is a firstborn child. | |
1235 | P OPf_PARENS This operator was parenthesized. | |
1236 | (Or block needs explicit scope entry.) | |
1237 | R OPf_REF Certified reference. | |
1238 | (Return container, not containee). | |
1239 | M OPf_MOD Will modify (lvalue). | |
1240 | S OPf_STACKED Some arg is arriving on the stack. | |
1241 | * OPf_SPECIAL Do something weird for this op (see op.h) | |
1242 | ||
1243 | Private flags, if any are set for an opcode, are displayed after a '/' | |
1244 | ||
1245 | 8 <@> leave[1 ref] vKP/REFC ->(end) | |
1246 | 7 <2> sassign vKS/2 ->8 | |
1247 | ||
1248 | They're opcode specific, and occur less often than the public ones, so | |
1249 | they're represented by short mnemonics instead of single-chars; see | |
1250 | F<op.h> for gory details, or try this quick 2-liner: | |
1251 | ||
1252 | $> perl -MB::Concise -de 1 | |
1253 | DB<1> |x \%B::Concise::priv | |
1254 | ||
1255 | =head1 FORMATTING SPECIFICATIONS | |
1256 | ||
1257 | For each line-style ('concise', 'terse', 'linenoise', etc.) there are | |
1258 | 3 format-specs which control how OPs are rendered. | |
1259 | ||
1260 | The first is the 'default' format, which is used in both basic and exec | |
1261 | modes to print all opcodes. The 2nd, goto-format, is used in exec | |
1262 | mode when branches are encountered. They're not real opcodes, and are | |
1263 | inserted to look like a closing curly brace. The tree-format is tree | |
1264 | specific. | |
1265 | ||
1266 | When a line is rendered, the correct format-spec is copied and scanned | |
1267 | for the following items; data is substituted in, and other | |
1268 | manipulations like basic indenting are done, for each opcode rendered. | |
1269 | ||
1270 | There are 3 kinds of items that may be populated; special patterns, | |
1271 | #vars, and literal text, which is copied verbatim. (Yes, it's a set | |
1272 | of s///g steps.) | |
1273 | ||
1274 | =head2 Special Patterns | |
1275 | ||
1276 | These items are the primitives used to perform indenting, and to | |
1277 | select text from amongst alternatives. | |
1278 | ||
1279 | =over 4 | |
1280 | ||
1281 | =item B<(x(>I<exec_text>B<;>I<basic_text>B<)x)> | |
1282 | ||
1283 | Generates I<exec_text> in exec mode, or I<basic_text> in basic mode. | |
1284 | ||
1285 | =item B<(*(>I<text>B<)*)> | |
1286 | ||
1287 | Generates one copy of I<text> for each indentation level. | |
1288 | ||
1289 | =item B<(*(>I<text1>B<;>I<text2>B<)*)> | |
1290 | ||
1291 | Generates one fewer copies of I<text1> than the indentation level, followed | |
1292 | by one copy of I<text2> if the indentation level is more than 0. | |
1293 | ||
1294 | =item B<(?(>I<text1>B<#>I<var>I<Text2>B<)?)> | |
1295 | ||
1296 | If the value of I<var> is true (not empty or zero), generates the | |
1297 | value of I<var> surrounded by I<text1> and I<Text2>, otherwise | |
1298 | nothing. | |
1299 | ||
1300 | =item B<~> | |
1301 | ||
1302 | Any number of tildes and surrounding whitespace will be collapsed to | |
1303 | a single space. | |
1304 | ||
1305 | =back | |
1306 | ||
1307 | =head2 # Variables | |
1308 | ||
1309 | These #vars represent opcode properties that you may want as part of | |
1310 | your rendering. The '#' is intended as a private sigil; a #var's | |
1311 | value is interpolated into the style-line, much like "read $this". | |
1312 | ||
1313 | These vars take 3 forms: | |
1314 | ||
1315 | =over 4 | |
1316 | ||
1317 | =item B<#>I<var> | |
1318 | ||
1319 | A property named 'var' is assumed to exist for the opcodes, and is | |
1320 | interpolated into the rendering. | |
1321 | ||
1322 | =item B<#>I<var>I<N> | |
1323 | ||
1324 | Generates the value of I<var>, left justified to fill I<N> spaces. | |
1325 | Note that this means while you can have properties 'foo' and 'foo2', | |
1326 | you cannot render 'foo2', but you could with 'foo2a'. You would be | |
1327 | wise not to rely on this behavior going forward ;-) | |
1328 | ||
1329 | =item B<#>I<Var> | |
1330 | ||
1331 | This ucfirst form of #var generates a tag-value form of itself for | |
1332 | display; it converts '#Var' into a 'Var => #var' style, which is then | |
1333 | handled as described above. (Imp-note: #Vars cannot be used for | |
1334 | conditional-fills, because the => #var transform is done after the check | |
1335 | for #Var's value). | |
1336 | ||
1337 | =back | |
1338 | ||
1339 | The following variables are 'defined' by B::Concise; when they are | |
1340 | used in a style, their respective values are plugged into the | |
1341 | rendering of each opcode. | |
1342 | ||
1343 | Only some of these are used by the standard styles, the others are | |
1344 | provided for you to delve into optree mechanics, should you wish to | |
1345 | add a new style (see L</add_style> below) that uses them. You can | |
1346 | also add new ones using L</add_callback>. | |
1347 | ||
1348 | =over 4 | |
1349 | ||
1350 | =item B<#addr> | |
1351 | ||
1352 | The address of the OP, in hexadecimal. | |
1353 | ||
1354 | =item B<#arg> | |
1355 | ||
1356 | The OP-specific information of the OP (such as the SV for an SVOP, the | |
1357 | non-local exit pointers for a LOOP, etc.) enclosed in parentheses. | |
1358 | ||
1359 | =item B<#class> | |
1360 | ||
1361 | The B-determined class of the OP, in all caps. | |
1362 | ||
1363 | =item B<#classsym> | |
1364 | ||
1365 | A single symbol abbreviating the class of the OP. | |
1366 | ||
1367 | =item B<#coplabel> | |
1368 | ||
1369 | The label of the statement or block the OP is the start of, if any. | |
1370 | ||
1371 | =item B<#exname> | |
1372 | ||
1373 | The name of the OP, or 'ex-foo' if the OP is a null that used to be a foo. | |
1374 | ||
1375 | =item B<#extarg> | |
1376 | ||
1377 | The target of the OP, or nothing for a nulled OP. | |
1378 | ||
1379 | =item B<#firstaddr> | |
1380 | ||
1381 | The address of the OP's first child, in hexadecimal. | |
1382 | ||
1383 | =item B<#flags> | |
1384 | ||
1385 | The OP's flags, abbreviated as a series of symbols. | |
1386 | ||
1387 | =item B<#flagval> | |
1388 | ||
1389 | The numeric value of the OP's flags. | |
1390 | ||
1391 | =item B<#hyphseq> | |
1392 | ||
1393 | The sequence number of the OP, or a hyphen if it doesn't have one. | |
1394 | ||
1395 | =item B<#label> | |
1396 | ||
1397 | 'NEXT', 'LAST', or 'REDO' if the OP is a target of one of those in exec | |
1398 | mode, or empty otherwise. | |
1399 | ||
1400 | =item B<#lastaddr> | |
1401 | ||
1402 | The address of the OP's last child, in hexadecimal. | |
1403 | ||
1404 | =item B<#name> | |
1405 | ||
1406 | The OP's name. | |
1407 | ||
1408 | =item B<#NAME> | |
1409 | ||
1410 | The OP's name, in all caps. | |
1411 | ||
1412 | =item B<#next> | |
1413 | ||
1414 | The sequence number of the OP's next OP. | |
1415 | ||
1416 | =item B<#nextaddr> | |
1417 | ||
1418 | The address of the OP's next OP, in hexadecimal. | |
1419 | ||
1420 | =item B<#noise> | |
1421 | ||
1422 | A one- or two-character abbreviation for the OP's name. | |
1423 | ||
1424 | =item B<#private> | |
1425 | ||
1426 | The OP's private flags, rendered with abbreviated names if possible. | |
1427 | ||
1428 | =item B<#privval> | |
1429 | ||
1430 | The numeric value of the OP's private flags. | |
1431 | ||
1432 | =item B<#seq> | |
1433 | ||
1434 | The sequence number of the OP. Note that this is a sequence number | |
1435 | generated by B::Concise. | |
1436 | ||
1437 | =item B<#seqnum> | |
1438 | ||
1439 | 5.8.x and earlier only. 5.9 and later do not provide this. | |
1440 | ||
1441 | The real sequence number of the OP, as a regular number and not adjusted | |
1442 | to be relative to the start of the real program. (This will generally be | |
1443 | a fairly large number because all of B<B::Concise> is compiled before | |
1444 | your program is). | |
1445 | ||
1446 | =item B<#opt> | |
1447 | ||
1448 | Whether or not the op has been optimised by the peephole optimiser. | |
1449 | ||
1450 | Only available in 5.9 and later. | |
1451 | ||
1452 | =item B<#static> | |
1453 | ||
1454 | Whether or not the op is statically defined. This flag is used by the | |
1455 | B::C compiler backend and indicates that the op should not be freed. | |
1456 | ||
1457 | Only available in 5.9 and later. | |
1458 | ||
1459 | =item B<#sibaddr> | |
1460 | ||
1461 | The address of the OP's next youngest sibling, in hexadecimal. | |
1462 | ||
1463 | =item B<#svaddr> | |
1464 | ||
1465 | The address of the OP's SV, if it has an SV, in hexadecimal. | |
1466 | ||
1467 | =item B<#svclass> | |
1468 | ||
1469 | The class of the OP's SV, if it has one, in all caps (e.g., 'IV'). | |
1470 | ||
1471 | =item B<#svval> | |
1472 | ||
1473 | The value of the OP's SV, if it has one, in a short human-readable format. | |
1474 | ||
1475 | =item B<#targ> | |
1476 | ||
1477 | The numeric value of the OP's targ. | |
1478 | ||
1479 | =item B<#targarg> | |
1480 | ||
1481 | The name of the variable the OP's targ refers to, if any, otherwise the | |
1482 | letter t followed by the OP's targ in decimal. | |
1483 | ||
1484 | =item B<#targarglife> | |
1485 | ||
1486 | Same as B<#targarg>, but followed by the COP sequence numbers that delimit | |
1487 | the variable's lifetime (or 'end' for a variable in an open scope) for a | |
1488 | variable. | |
1489 | ||
1490 | =item B<#typenum> | |
1491 | ||
1492 | The numeric value of the OP's type, in decimal. | |
1493 | ||
1494 | =back | |
1495 | ||
1496 | =head1 Using B::Concise outside of the O framework | |
1497 | ||
1498 | The common (and original) usage of B::Concise was for command-line | |
1499 | renderings of simple code, as given in EXAMPLE. But you can also use | |
1500 | B<B::Concise> from your code, and call compile() directly, and | |
1501 | repeatedly. By doing so, you can avoid the compile-time only | |
1502 | operation of O.pm, and even use the debugger to step through | |
1503 | B::Concise::compile() itself. | |
1504 | ||
1505 | Once you're doing this, you may alter Concise output by adding new | |
1506 | rendering styles, and by optionally adding callback routines which | |
1507 | populate new variables, if such were referenced from those (just | |
1508 | added) styles. | |
1509 | ||
1510 | =head2 Example: Altering Concise Renderings | |
1511 | ||
1512 | use B::Concise qw(set_style add_callback); | |
1513 | add_style($yourStyleName => $defaultfmt, $gotofmt, $treefmt); | |
1514 | add_callback | |
1515 | ( sub { | |
1516 | my ($h, $op, $format, $level, $stylename) = @_; | |
1517 | $h->{variable} = some_func($op); | |
1518 | }); | |
1519 | $walker = B::Concise::compile(@options,@subnames,@subrefs); | |
1520 | $walker->(); | |
1521 | ||
1522 | =head2 set_style() | |
1523 | ||
1524 | B<set_style> accepts 3 arguments, and updates the three format-specs | |
1525 | comprising a line-style (basic-exec, goto, tree). It has one minor | |
1526 | drawback though; it doesn't register the style under a new name. This | |
1527 | can become an issue if you render more than once and switch styles. | |
1528 | Thus you may prefer to use add_style() and/or set_style_standard() | |
1529 | instead. | |
1530 | ||
1531 | =head2 set_style_standard($name) | |
1532 | ||
1533 | This restores one of the standard line-styles: C<terse>, C<concise>, | |
1534 | C<linenoise>, C<debug>, C<env>, into effect. It also accepts style | |
1535 | names previously defined with add_style(). | |
1536 | ||
1537 | =head2 add_style() | |
1538 | ||
1539 | This subroutine accepts a new style name and three style arguments as | |
1540 | above, and creates, registers, and selects the newly named style. It is | |
1541 | an error to re-add a style; call set_style_standard() to switch between | |
1542 | several styles. | |
1543 | ||
1544 | =head2 add_callback() | |
1545 | ||
1546 | If your newly minted styles refer to any new #variables, you'll need | |
1547 | to define a callback subroutine that will populate (or modify) those | |
1548 | variables. They are then available for use in the style you've | |
1549 | chosen. | |
1550 | ||
1551 | The callbacks are called for each opcode visited by Concise, in the | |
1552 | same order as they are added. Each subroutine is passed five | |
1553 | parameters. | |
1554 | ||
1555 | 1. A hashref, containing the variable names and values which are | |
1556 | populated into the report-line for the op | |
1557 | 2. the op, as a B<B::OP> object | |
1558 | 3. a reference to the format string | |
1559 | 4. the formatting (indent) level | |
1560 | 5. the selected stylename | |
1561 | ||
1562 | To define your own variables, simply add them to the hash, or change | |
1563 | existing values if you need to. The level and format are passed in as | |
1564 | references to scalars, but it is unlikely that they will need to be | |
1565 | changed or even used. | |
1566 | ||
1567 | =head2 Running B::Concise::compile() | |
1568 | ||
1569 | B<compile> accepts options as described above in L</OPTIONS>, and | |
1570 | arguments, which are either coderefs, or subroutine names. | |
1571 | ||
1572 | It constructs and returns a $treewalker coderef, which when invoked, | |
1573 | traverses, or walks, and renders the optrees of the given arguments to | |
1574 | STDOUT. You can reuse this, and can change the rendering style used | |
1575 | each time; thereafter the coderef renders in the new style. | |
1576 | ||
1577 | B<walk_output> lets you change the print destination from STDOUT to | |
1578 | another open filehandle, or into a string passed as a ref (unless | |
1579 | you've built perl with -Uuseperlio). | |
1580 | ||
1581 | my $walker = B::Concise::compile('-terse','aFuncName', \&aSubRef); # 1 | |
1582 | walk_output(\my $buf); | |
1583 | $walker->(); # 1 renders -terse | |
1584 | set_style_standard('concise'); # 2 | |
1585 | $walker->(); # 2 renders -concise | |
1586 | $walker->(@new); # 3 renders whatever | |
1587 | print "3 different renderings: terse, concise, and @new: $buf\n"; | |
1588 | ||
1589 | When $walker is called, it traverses the subroutines supplied when it | |
1590 | was created, and renders them using the current style. You can change | |
1591 | the style afterwards in several different ways: | |
1592 | ||
1593 | 1. call C<compile>, altering style or mode/order | |
1594 | 2. call C<set_style_standard> | |
1595 | 3. call $walker, passing @new options | |
1596 | ||
1597 | Passing new options to the $walker is the easiest way to change | |
1598 | amongst any pre-defined styles (the ones you add are automatically | |
1599 | recognized as options), and is the only way to alter rendering order | |
1600 | without calling compile again. Note however that rendering state is | |
1601 | still shared amongst multiple $walker objects, so they must still be | |
1602 | used in a coordinated manner. | |
1603 | ||
1604 | =head2 B::Concise::reset_sequence() | |
1605 | ||
1606 | This function (not exported) lets you reset the sequence numbers (note | |
1607 | that they're numbered arbitrarily, their goal being to be human | |
1608 | readable). Its purpose is mostly to support testing, i.e. to compare | |
1609 | the concise output from two identical anonymous subroutines (but | |
1610 | different instances). Without the reset, B::Concise, seeing that | |
1611 | they're separate optrees, generates different sequence numbers in | |
1612 | the output. | |
1613 | ||
1614 | =head2 Errors | |
1615 | ||
1616 | Errors in rendering (non-existent function-name, non-existent coderef) | |
1617 | are written to the STDOUT, or wherever you've set it via | |
1618 | walk_output(). | |
1619 | ||
1620 | Errors using the various *style* calls, and bad args to walk_output(), | |
1621 | result in die(). Use an eval if you wish to catch these errors and | |
1622 | continue processing. | |
1623 | ||
1624 | =head1 AUTHOR | |
1625 | ||
1626 | Stephen McCamant, E<lt>smcc@CSUA.Berkeley.EDUE<gt>. | |
1627 | ||
1628 | =cut |