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.
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.
13 use warnings; # uses #3 and #4, since warnings uses Carp
15 use Exporter (); # use #5
17 our $VERSION = "0.64";
18 our @ISA = qw(Exporter);
19 our @EXPORT_OK = qw( set_style set_style_standard add_callback
20 concise_subref concise_cv concise_main
21 add_style walk_output compile reset_sequence );
23 ( io => [qw( walk_output compile reset_sequence )],
24 style => [qw( add_style set_style_standard )],
25 cb => [qw( add_callback )],
26 mech => [qw( concise_subref concise_cv concise_main )], );
29 use B qw(class ppname main_start main_root main_cv cstring svref_2object
30 SVf_IOK SVf_NOK SVf_POK SVf_IVisUV SVf_FAKE OPf_KIDS OPf_SPECIAL
35 ["(?(#label =>\n)?)(*( )*)#class (#addr) #name (?([#targ])?) "
36 . "#svclass~(?((#svaddr))?)~#svval~(?(label \"#coplabel\")?)\n",
37 "(*( )*)goto #class (#addr)\n",
40 ["#hyphseq2 (*( (x( ;)x))*)<#classsym> "
41 . "#exname#arg(?([#targarglife])?)~#flags(?(/#private)?)(x(;~->#next)x)\n"
42 , " (*( )*) goto #seq\n",
43 "(?(<#seq>)?)#exname#arg(?([#targarglife])?)"],
45 ["(x(;(*( )*))x)#noise#arg(?([#targarg])?)(x( ;\n)x)",
47 "(?(#seq)?)#noise#arg(?([#targarg])?)"],
49 ["#class (#addr)\n\top_next\t\t#nextaddr\n\top_sibling\t#sibaddr\n\t"
50 . "op_ppaddr\tPL_ppaddr[OP_#NAME]\n\top_type\t\t#typenum\n" .
51 ($] > 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)?)",
57 "env" => [$ENV{B_CONCISE_FORMAT}, $ENV{B_CONCISE_GOTO_FORMAT},
58 $ENV{B_CONCISE_TREE_FORMAT}],
61 # Renderings, ie how Concise prints, is controlled by these vars
63 our $stylename; # selects current style from %style
64 my $order = "basic"; # how optree is walked & printed: basic, exec, tree
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);
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 $do_main = 0; # force printing of main routine
78 # another factor: can affect all styles!
79 our @callbacks; # allow external management
81 set_style_standard("concise");
87 ($format, $gotofmt, $treefmt) = @_;
88 #warn "set_style: deprecated, use set_style_standard instead\n"; # someday
89 die "expecting 3 style-format args\n" unless @_ == 3;
93 my ($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 = $newstyle; # update rendering state
101 sub set_style_standard {
102 ($stylename) = @_; # update rendering state
103 die "err: style '$stylename' unknown\n" unless exists $style{$stylename};
104 set_style(@{$style{$stylename}});
111 # output handle, used with all Concise-output printing
112 our $walkHandle; # public for your convenience
113 BEGIN { $walkHandle = \*STDOUT }
115 sub walk_output { # updates $walkHandle
117 return $walkHandle unless $handle; # allow use as accessor
119 if (ref $handle eq 'SCALAR') {
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
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 = $handle;
135 my($order, $coderef) = @_;
136 my $codeobj = svref_2object($coderef);
138 return concise_stashref(@_)
139 unless ref $codeobj eq 'B::CV';
140 concise_cv_obj($order, $codeobj);
143 sub concise_stashref {
145 foreach my $k (sort keys %$h) {
147 my $coderef = *s{CODE} or next;
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 $codeobj";
157 # This should have been called concise_subref, but it was exported
158 # under this name in versions before 0.56
159 sub concise_cv { concise_subref(@_); }
162 my ($order, $cv) = @_;
164 die "err: coderef has no START\n" if class($cv->START) eq "NULL";
165 sequence($cv->START);
166 if ($order eq "exec") {
167 walk_exec($cv->START);
168 } elsif ($order eq "basic") {
169 walk_topdown($cv->ROOT, sub { $_[0]->concise($_[1]) }, 0);
171 print $walkHandle tree($cv->ROOT, 0);
177 sequence(main_start);
179 if ($order eq "exec") {
180 return if class(main_start) eq "NULL";
181 walk_exec(main_start);
182 } elsif ($order eq "tree") {
183 return if class(main_root) eq "NULL";
184 print $walkHandle tree(main_root, 0);
185 } elsif ($order eq "basic") {
186 return if class(main_root) eq "NULL";
187 walk_topdown(main_root,
188 sub { $_[0]->concise($_[1]) }, 0);
192 sub concise_specials {
193 my($name, $order, @cv_s) = @_;
195 if ($name eq "BEGIN") {
196 splice(@cv_s, 0, 7); # skip 7 BEGIN blocks in this file
197 } elsif ($name eq "CHECK") {
198 pop @cv_s; # skip the CHECK block that calls us
201 print $walkHandle "$name $i:\n";
203 concise_cv_obj($order, $cv);
207 my $start_sym = "\e(0"; # "\cN" sometimes also works
208 my $end_sym = "\e(B"; # "\cO" respectively
210 my @tree_decorations =
211 ([" ", "--", "+-", "|-", "| ", "`-", "-", 1],
212 [" ", "-", "+", "+", "|", "`", "", 0],
213 [" ", map("$start_sym$_$end_sym", "qq", "wq", "tq", "x ", "mq", "q"), 1],
214 [" ", map("$start_sym$_$end_sym", "q", "w", "t", "x", "m"), "", 0],
219 # set rendering state from options and args
220 my @options = grep(/^-/, @_);
221 my @args = grep(!/^-/, @_);
222 for my $o (@options) {
224 if ($o eq "-basic") {
226 } elsif ($o eq "-exec") {
228 } elsif ($o eq "-tree") {
232 elsif ($o eq "-compact") {
234 } elsif ($o eq "-loose") {
236 } elsif ($o eq "-vt") {
238 } elsif ($o eq "-ascii") {
242 elsif ($o =~ /^-base(\d+)$/) {
244 } elsif ($o eq "-bigendian") {
246 } elsif ($o eq "-littleendian") {
249 elsif ($o eq "-nobanner") {
251 } elsif ($o eq "-banner") {
254 elsif ($o eq "-main") {
256 } elsif ($o eq "-nomain") {
260 elsif (exists $style{substr($o, 1)}) {
261 $stylename = substr($o, 1);
262 set_style_standard($stylename);
264 warn "Option $o unrecognized";
271 my (@args) = compileOpts(@_);
273 my @newargs = compileOpts(@_); # accept new rendering options
274 warn "disregarding non-options: @newargs\n" if @newargs;
276 for my $objname (@args) {
277 next unless $objname; # skip null args to avoid noisy responses
279 if ($objname eq "BEGIN") {
280 concise_specials("BEGIN", $order,
281 B::begin_av->isa("B::AV") ?
282 B::begin_av->ARRAY : ());
283 } elsif ($objname eq "INIT") {
284 concise_specials("INIT", $order,
285 B::init_av->isa("B::AV") ?
286 B::init_av->ARRAY : ());
287 } elsif ($objname eq "CHECK") {
288 concise_specials("CHECK", $order,
289 B::check_av->isa("B::AV") ?
290 B::check_av->ARRAY : ());
291 } elsif ($objname eq "END") {
292 concise_specials("END", $order,
293 B::end_av->isa("B::AV") ?
294 B::end_av->ARRAY : ());
297 # convert function names to subrefs
300 print $walkHandle "B::Concise::compile($objname)\n"
304 $objname = "main::" . $objname unless $objname =~ /::/;
305 print $walkHandle "$objname:\n";
307 die "err: unknown function ($objname)\n"
308 unless *{$objname}{CODE};
309 $objref = \&$objname;
311 concise_subref($order, $objref);
314 if (!@args or $do_main) {
315 print $walkHandle "main program:\n" if $do_main;
316 concise_main($order);
318 return @args; # something
323 my $lastnext; # remembers op-chain, used to insert gotos
325 my %opclass = ('OP' => "0", 'UNOP' => "1", 'BINOP' => "2", 'LOGOP' => "|",
326 'LISTOP' => "@", 'PMOP' => "/", 'SVOP' => "\$", 'GVOP' => "*",
327 'PVOP' => '"', 'LOOP' => "{", 'COP' => ";", 'PADOP' => "#");
329 no warnings 'qw'; # "Possible attempt to put comments..."; use #7
331 qw'# () sc ( @? 1 $* gv *{ m$ m@ m% m? p/ *$ $ $# & a& pt \\ s\\ rf bl
332 ` *? <> ?? ?/ r/ c/ // qr s/ /c y/ = @= C sC Cp sp df un BM po +1 +I
333 -1 -I 1+ I+ 1- I- ** * i* / i/ %$ i% x + i+ - i- . " << >> < i<
334 > i> <= i, >= i. == i= != i! <? i? s< s> s, s. s= s! s? b& b^ b| -0 -i
335 ! ~ a2 si cs rd sr e^ lg sq in %x %o ab le ss ve ix ri sf FL od ch cy
336 uf lf uc lc qm @ [f [ @[ eh vl ky dl ex % ${ @{ uk pk st jn ) )[ a@
337 a% sl +] -] [- [+ so rv GS GW MS MW .. f. .f && || ^^ ?: &= |= -> s{ s}
338 v} ca wa di rs ;; ; ;d }{ { } {} f{ it {l l} rt }l }n }r dm }g }e ^o
339 ^c ^| ^# um bm t~ u~ ~d DB db ^s se ^g ^r {w }w pf pr ^O ^K ^R ^W ^d ^v
340 ^e ^t ^k t. fc ic fl .s .p .b .c .l .a .h g1 s1 g2 s2 ?. l? -R -W -X -r
341 -w -x -e -o -O -z -s -M -A -C -S -c -b -f -d -p -l -u -g -k -t -T -B cd
342 co cr u. cm ut r. l@ s@ r@ mD uD oD rD tD sD wD cD f$ w$ p$ sh e$ k$ g3
343 g4 s4 g5 s5 T@ C@ L@ G@ A@ S@ Hg Hc Hr Hw Mg Mc Ms Mr Sg Sc So rq do {e
344 e} {t t} g6 G6 6e g7 G7 7e g8 G8 8e g9 G9 9e 6s 7s 8s 9s 6E 7E 8E 9E Pn
345 Pu GP SP EP Gn Gg GG SG EG g0 c$ lk t$ ;s n> // /= CO';
347 my $chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
352 push @v, "v" if ($x & 3) == 1;
353 push @v, "s" if ($x & 3) == 2;
354 push @v, "l" if ($x & 3) == 3;
355 push @v, "K" if $x & 4;
356 push @v, "P" if $x & 8;
357 push @v, "R" if $x & 16;
358 push @v, "M" if $x & 32;
359 push @v, "S" if $x & 64;
360 push @v, "*" if $x & 128;
366 return "-" . base_n(-$x) if $x < 0;
368 do { $str .= substr($chars, $x % $base, 1) } while $x = int($x / $base);
369 $str = reverse $str if $big_endian;
385 return "-" if not exists $sequence_num{$$op};
386 return base_n($sequence_num{$$op});
390 my($op, $sub, $level) = @_;
392 if ($op->flags & OPf_KIDS) {
393 for (my $kid = $op->first; $$kid; $kid = $kid->sibling) {
394 walk_topdown($kid, $sub, $level + 1);
397 if (class($op) eq "PMOP") {
398 my $maybe_root = $op->pmreplroot;
399 if (ref($maybe_root) and $maybe_root->isa("B::OP")) {
400 # It really is the root of the replacement, not something
401 # else stored here for lack of space elsewhere
402 walk_topdown($maybe_root, $sub, $level + 1);
408 my($ar, $level) = @_;
410 if (ref($l) eq "ARRAY") {
411 walklines($l, $level + 1);
419 my($top, $level) = @_;
422 my @todo = ([$top, \@lines]);
423 while (@todo and my($op, $targ) = @{shift @todo}) {
424 for (; $$op; $op = $op->next) {
425 last if $opsseen{$$op}++;
427 my $name = $op->name;
428 if (class($op) eq "LOGOP") {
431 push @todo, [$op->other, $ar];
432 } elsif ($name eq "subst" and $ {$op->pmreplstart}) {
435 push @todo, [$op->pmreplstart, $ar];
436 } elsif ($name =~ /^enter(loop|iter)$/) {
438 $labels{${$op->nextop}} = "NEXT";
439 $labels{${$op->lastop}} = "LAST";
440 $labels{${$op->redoop}} = "REDO";
442 $labels{$op->nextop->seq} = "NEXT";
443 $labels{$op->lastop->seq} = "LAST";
444 $labels{$op->redoop->seq} = "REDO";
449 walklines(\@lines, 0);
452 # The structure of this routine is purposely modeled after op.c's peep()
456 return if class($op) eq "NULL" or exists $sequence_num{$$op};
457 for (; $$op; $op = $op->next) {
458 last if exists $sequence_num{$$op};
459 my $name = $op->name;
460 if ($name =~ /^(null|scalar|lineseq|scope)$/) {
461 next if $oldop and $ {$op->next};
463 $sequence_num{$$op} = $seq_max++;
464 if (class($op) eq "LOGOP") {
465 my $other = $op->other;
466 $other = $other->next while $other->name eq "null";
468 } elsif (class($op) eq "LOOP") {
469 my $redoop = $op->redoop;
470 $redoop = $redoop->next while $redoop->name eq "null";
472 my $nextop = $op->nextop;
473 $nextop = $nextop->next while $nextop->name eq "null";
475 my $lastop = $op->lastop;
476 $lastop = $lastop->next while $lastop->name eq "null";
478 } elsif ($name eq "subst" and $ {$op->pmreplstart}) {
479 my $replstart = $op->pmreplstart;
480 $replstart = $replstart->next while $replstart->name eq "null";
481 sequence($replstart);
488 sub fmt_line { # generate text-line for op.
489 my($hr, $op, $text, $level) = @_;
491 $_->($hr, $op, \$text, \$level, $stylename) for @callbacks;
493 return '' if $hr->{SKIP}; # suppress line if a callback said so
494 return '' if $hr->{goto} and $hr->{goto} eq '-'; # no goto nowhere
496 # spec: (?(text1#varText2)?)
497 $text =~ s/\(\?\(([^\#]*?)\#(\w+)([^\#]*?)\)\?\)/
498 $hr->{$2} ? $1.$hr->{$2}.$3 : ""/eg;
500 # spec: (x(exec_text;basic_text)x)
501 $text =~ s/\(x\((.*?);(.*?)\)x\)/$order eq "exec" ? $1 : $2/egs;
504 $text =~ s/\(\*\(([^;]*?)\)\*\)/$1 x $level/egs;
506 # spec: (*(text1;text2)*)
507 $text =~ s/\(\*\((.*?);(.*?)\)\*\)/$1 x ($level - 1) . $2 x ($level>0)/egs;
509 # convert #Var to tag=>val form: Var\t#var
510 $text =~ s/\#([A-Z][a-z]+)(\d+)?/\t\u$1\t\L#$1$2/gs;
513 $text =~ s/\#([a-zA-Z]+)(\d+)/sprintf("%-$2s", $hr->{$1})/eg;
515 $text =~ s/\#([a-zA-Z]+)/$hr->{$1}/eg; # populate #var's
516 $text =~ s/[ \t]*~+[ \t]*/ /g; # squeeze tildes
518 return "$text\n" if $text ne "";
519 return $text; # suppress empty lines
523 $priv{$_}{128} = "LVINTRO"
524 for ("pos", "substr", "vec", "threadsv", "gvsv", "rv2sv", "rv2hv", "rv2gv",
525 "rv2av", "rv2arylen", "aelem", "helem", "aslice", "hslice", "padsv",
526 "padav", "padhv", "enteriter");
527 $priv{$_}{64} = "REFC" for ("leave", "leavesub", "leavesublv", "leavewrite");
528 $priv{"aassign"}{64} = "COMMON";
529 $priv{"aassign"}{32} = "PHASH" if $] < 5.009;
530 $priv{"sassign"}{64} = "BKWARD";
531 $priv{$_}{64} = "RTIME" for ("match", "subst", "substcont");
532 @{$priv{"trans"}}{1,2,4,8,16,64} = ("<UTF", ">UTF", "IDENT", "SQUASH", "DEL",
534 $priv{"repeat"}{64} = "DOLIST";
535 $priv{"leaveloop"}{64} = "CONT";
536 @{$priv{$_}}{32,64,96} = ("DREFAV", "DREFHV", "DREFSV")
537 for (qw(rv2gv rv2sv padsv aelem helem));
538 @{$priv{"entersub"}}{16,32,64} = ("DBG","TARG","NOMOD");
539 @{$priv{$_}}{4,8,128} = ("INARGS","AMPER","NO()") for ("entersub", "rv2cv");
540 $priv{"gv"}{32} = "EARLYCV";
541 $priv{"aelem"}{16} = $priv{"helem"}{16} = "LVDEFER";
542 $priv{$_}{16} = "OURINTR" for ("gvsv", "rv2sv", "rv2av", "rv2hv", "r2gv",
544 $priv{$_}{16} = "TARGMY"
545 for (map(($_,"s$_"),"chop", "chomp"),
546 map(($_,"i_$_"), "postinc", "postdec", "multiply", "divide", "modulo",
547 "add", "subtract", "negate"), "pow", "concat", "stringify",
548 "left_shift", "right_shift", "bit_and", "bit_xor", "bit_or",
549 "complement", "atan2", "sin", "cos", "rand", "exp", "log", "sqrt",
550 "int", "hex", "oct", "abs", "length", "index", "rindex", "sprintf",
551 "ord", "chr", "crypt", "quotemeta", "join", "push", "unshift", "flock",
552 "chdir", "chown", "chroot", "unlink", "chmod", "utime", "rename",
553 "link", "symlink", "mkdir", "rmdir", "wait", "waitpid", "system",
554 "exec", "kill", "getppid", "getpgrp", "setpgrp", "getpriority",
555 "setpriority", "time", "sleep");
556 $priv{$_}{4} = "REVERSED" for ("enteriter", "iter");
557 @{$priv{"const"}}{4,8,16,32,64,128} = ("SHORT","STRICT","ENTERED",'$[',"BARE","WARN");
558 $priv{"flip"}{64} = $priv{"flop"}{64} = "LINENUM";
559 $priv{"list"}{64} = "GUESSED";
560 $priv{"delete"}{64} = "SLICE";
561 $priv{"exists"}{64} = "SUB";
562 $priv{$_}{64} = "LOCALE"
563 for ("sort", "prtf", "sprintf", "slt", "sle", "seq", "sne", "sgt", "sge",
564 "scmp", "lc", "uc", "lcfirst", "ucfirst");
565 @{$priv{"sort"}}{1,2,4,8,16} = ("NUM", "INT", "REV", "INPLACE","DESC");
566 $priv{"threadsv"}{64} = "SVREFd";
567 @{$priv{$_}}{16,32,64,128} = ("INBIN","INCR","OUTBIN","OUTCR")
568 for ("open", "backtick");
569 $priv{"exit"}{128} = "VMS";
570 $priv{$_}{2} = "FTACCESS"
571 for ("ftrread", "ftrwrite", "ftrexec", "fteread", "ftewrite", "fteexec");
573 # Stacked filetests are post 5.8.x
574 $priv{$_}{4} = "FTSTACKED"
575 for ("ftrread", "ftrwrite", "ftrexec", "fteread", "ftewrite", "fteexec",
576 "ftis", "fteowned", "ftrowned", "ftzero", "ftsize", "ftmtime",
577 "ftatime", "ftctime", "ftsock", "ftchr", "ftblk", "ftfile", "ftdir",
578 "ftpipe", "ftlink", "ftsuid", "ftsgid", "ftsvtx", "fttty", "fttext",
580 # Lexical $_ is post 5.8.x
581 $priv{$_}{2} = "GREPLEX"
582 for ("mapwhile", "mapstart", "grepwhile", "grepstart");
588 for my $flag (128, 96, 64, 32, 16, 8, 4, 2, 1) {
589 if ($priv{$name}{$flag} and $x & $flag and $x >= $flag) {
591 push @s, $priv{$name}{$flag};
595 return join(",", @s);
600 $hr->{svclass} = class($sv);
601 $hr->{svclass} = "UV"
602 if $hr->{svclass} eq "IV" and $sv->FLAGS & SVf_IVisUV;
603 $hr->{svaddr} = sprintf("%#x", $$sv);
604 if ($hr->{svclass} eq "GV") {
606 my $stash = $gv->STASH->NAME;
607 if ($stash eq "main") {
610 $stash = $stash . "::";
612 $hr->{svval} = "*$stash" . $gv->SAFENAME;
613 return "*$stash" . $gv->SAFENAME;
615 while (class($sv) eq "RV") {
616 $hr->{svval} .= "\\";
619 if (class($sv) eq "SPECIAL") {
620 $hr->{svval} .= ["Null", "sv_undef", "sv_yes", "sv_no"]->[$$sv];
621 } elsif ($sv->FLAGS & SVf_NOK) {
622 $hr->{svval} .= $sv->NV;
623 } elsif ($sv->FLAGS & SVf_IOK) {
624 $hr->{svval} .= $sv->int_value;
625 } elsif ($sv->FLAGS & SVf_POK) {
626 $hr->{svval} .= cstring($sv->PV);
627 } elsif (class($sv) eq "HV") {
628 $hr->{svval} .= 'HASH';
631 $hr->{svval} = 'undef' unless defined $hr->{svval};
632 my $out = $hr->{svclass};
633 return $out .= " $hr->{svval}" ;
638 my ($op, $level, $format) = @_;
640 $h{exname} = $h{name} = $op->name;
641 $h{NAME} = uc $h{name};
642 $h{class} = class($op);
643 $h{extarg} = $h{targ} = $op->targ;
644 $h{extarg} = "" unless $h{extarg};
645 if ($h{name} eq "null" and $h{targ}) {
646 # targ holds the old type
647 $h{exname} = "ex-" . substr(ppname($h{targ}), 3);
649 } elsif ($op->name =~ /^leave(sub(lv)?|write)?$/) {
650 # targ potentially holds a reference count
651 if ($op->private & 64) {
652 my $refs = "ref" . ($h{targ} != 1 ? "s" : "");
653 $h{targarglife} = $h{targarg} = "$h{targ} $refs";
656 my $padname = (($curcv->PADLIST->ARRAY)[0]->ARRAY)[$h{targ}];
657 if (defined $padname and class($padname) ne "SPECIAL") {
658 $h{targarg} = $padname->PVX;
659 if ($padname->FLAGS & SVf_FAKE) {
661 $h{targarglife} = "$h{targarg}:FAKE";
663 # These changes relate to the jumbo closure fix.
664 # See changes 19939 and 20005
666 $fake .= 'a' if $padname->IVX & 1; # PAD_FAKELEX_ANON
667 $fake .= 'm' if $padname->IVX & 2; # PAD_FAKELEX_MULTI
668 $fake .= ':' . $padname->NVX if $curcv->CvFLAGS & CVf_ANON;
669 $h{targarglife} = "$h{targarg}:FAKE:$fake";
673 my $intro = $padname->NVX - $cop_seq_base;
674 my $finish = int($padname->IVX) - $cop_seq_base;
675 $finish = "end" if $finish == 999999999 - $cop_seq_base;
676 $h{targarglife} = "$h{targarg}:$intro,$finish";
679 $h{targarglife} = $h{targarg} = "t" . $h{targ};
683 $h{svclass} = $h{svaddr} = $h{svval} = "";
684 if ($h{class} eq "PMOP") {
685 my $precomp = $op->precomp;
686 if (defined $precomp) {
687 $precomp = cstring($precomp); # Escape literal control sequences
688 $precomp = "/$precomp/";
692 my $pmreplroot = $op->pmreplroot;
694 if (ref($pmreplroot) eq "B::GV") {
695 # with C<@stash_array = split(/pat/, str);>,
696 # *stash_array is stored in /pat/'s pmreplroot.
697 $h{arg} = "($precomp => \@" . $pmreplroot->NAME . ")";
698 } elsif (!ref($pmreplroot) and $pmreplroot) {
699 # same as the last case, except the value is actually a
700 # pad offset for where the GV is kept (this happens under
702 my $gv = (($curcv->PADLIST->ARRAY)[1]->ARRAY)[$pmreplroot];
703 $h{arg} = "($precomp => \@" . $gv->NAME . ")";
704 } elsif ($ {$op->pmreplstart}) {
706 $pmreplstart = "replstart->" . seq($op->pmreplstart);
707 $h{arg} = "(" . join(" ", $precomp, $pmreplstart) . ")";
709 $h{arg} = "($precomp)";
711 } elsif ($h{class} eq "PVOP" and $h{name} ne "trans") {
712 $h{arg} = '("' . $op->pv . '")';
713 $h{svval} = '"' . $op->pv . '"';
714 } elsif ($h{class} eq "COP") {
715 my $label = $op->label;
716 $h{coplabel} = $label;
717 $label = $label ? "$label: " : "";
720 $loc .= ":" . $op->line;
721 my($stash, $cseq) = ($op->stash->NAME, $op->cop_seq - $cop_seq_base);
722 my $arybase = $op->arybase;
723 $arybase = $arybase ? ' $[=' . $arybase : "";
724 $h{arg} = "($label$stash $cseq $loc$arybase)";
725 } elsif ($h{class} eq "LOOP") {
726 $h{arg} = "(next->" . seq($op->nextop) . " last->" . seq($op->lastop)
727 . " redo->" . seq($op->redoop) . ")";
728 } elsif ($h{class} eq "LOGOP") {
730 $h{arg} = "(other->" . seq($op->other) . ")";
731 } elsif ($h{class} eq "SVOP") {
732 unless ($h{name} eq 'aelemfast' and $op->flags & OPf_SPECIAL) {
734 my $sv = (($curcv->PADLIST->ARRAY)[1]->ARRAY)[$op->targ];
735 $h{arg} = "[" . concise_sv($sv, \%h) . "]";
736 $h{targarglife} = $h{targarg} = "";
738 $h{arg} = "(" . concise_sv($op->sv, \%h) . ")";
741 } elsif ($h{class} eq "PADOP") {
742 my $sv = (($curcv->PADLIST->ARRAY)[1]->ARRAY)[$op->padix];
743 $h{arg} = "[" . concise_sv($sv, \%h) . "]";
745 $h{seq} = $h{hyphseq} = seq($op);
746 $h{seq} = "" if $h{seq} eq "-";
749 $h{static} = $op->static;
750 $h{label} = $labels{$$op};
752 $h{seqnum} = $op->seq;
753 $h{label} = $labels{$op->seq};
755 $h{next} = $op->next;
756 $h{next} = (class($h{next}) eq "NULL") ? "(end)" : seq($h{next});
757 $h{nextaddr} = sprintf("%#x", $ {$op->next});
758 $h{sibaddr} = sprintf("%#x", $ {$op->sibling});
759 $h{firstaddr} = sprintf("%#x", $ {$op->first}) if $op->can("first");
760 $h{lastaddr} = sprintf("%#x", $ {$op->last}) if $op->can("last");
762 $h{classsym} = $opclass{$h{class}};
763 $h{flagval} = $op->flags;
764 $h{flags} = op_flags($op->flags);
765 $h{privval} = $op->private;
766 $h{private} = private_flags($h{name}, $op->private);
767 $h{addr} = sprintf("%#x", $$op);
768 $h{typenum} = $op->type;
769 $h{noise} = $linenoise[$op->type];
771 return fmt_line(\%h, $op, $format, $level);
775 my($op, $level) = @_;
776 if ($order eq "exec" and $lastnext and $$lastnext != $$op) {
777 # insert a 'goto' line
778 my $synth = {"seq" => seq($lastnext), "class" => class($lastnext),
779 "addr" => sprintf("%#x", $$lastnext),
780 "goto" => seq($lastnext), # simplify goto '-' removal
782 print $walkHandle fmt_line($synth, $op, $gotofmt, $level+1);
784 $lastnext = $op->next;
785 print $walkHandle concise_op($op, $level, $format);
788 # B::OP::terse (see Terse.pm) now just calls this
790 my($op, $level) = @_;
792 # This isn't necessarily right, but there's no easy way to get
793 # from an OP to the right CV. This is a limitation of the
794 # ->terse() interface style, and there isn't much to do about
795 # it. In particular, we can die in concise_op if the main pad
796 # isn't long enough, or has the wrong kind of entries, compared to
797 # the pad a sub was compiled with. The fix for that would be to
798 # make a backwards compatible "terse" format that never even
799 # looked at the pad, just like the old B::Terse. I don't think
800 # that's worth the effort, though.
801 $curcv = main_cv unless $curcv;
803 if ($order eq "exec" and $lastnext and $$lastnext != $$op) {
805 my $h = {"seq" => seq($lastnext), "class" => class($lastnext),
806 "addr" => sprintf("%#x", $$lastnext)};
808 fmt_line($h, $op, $style{"terse"}[1], $level+1);
810 $lastnext = $op->next;
812 concise_op($op, $level, $style{"terse"}[0]);
818 my $style = $tree_decorations[$tree_style];
819 my($space, $single, $kids, $kid, $nokid, $last, $lead, $size) = @$style;
820 my $name = concise_op($op, $level, $treefmt);
821 if (not $op->flags & OPf_KIDS) {
825 for (my $kid = $op->first; $$kid; $kid = $kid->sibling) {
826 push @lines, tree($kid, $level+1);
829 for ($i = $#lines; substr($lines[$i], 0, 1) eq " "; $i--) {
830 $lines[$i] = $space . $lines[$i];
833 $lines[$i] = $last . $lines[$i];
835 if (substr($lines[$i], 0, 1) eq " ") {
836 $lines[$i] = $nokid . $lines[$i];
838 $lines[$i] = $kid . $lines[$i];
841 $lines[$i] = $kids . $lines[$i];
843 $lines[0] = $single . $lines[0];
845 return("$name$lead" . shift @lines,
846 map(" " x (length($name)+$size) . $_, @lines));
849 # *** Warning: fragile kludge ahead ***
850 # Because the B::* modules run in the same interpreter as the code
851 # they're compiling, their presence tends to distort the view we have of
852 # the code we're looking at. In particular, perl gives sequence numbers
853 # to COPs. If the program we're looking at were run on its own, this
854 # would start at 1. Because all of B::Concise and all the modules it
855 # uses are compiled first, though, by the time we get to the user's
856 # program the sequence number is already pretty high, which could be
857 # distracting if you're trying to tell OPs apart. Therefore we'd like to
858 # subtract an offset from all the sequence numbers we display, to
859 # restore the simpler view of the world. The trick is to know what that
860 # offset will be, when we're still compiling B::Concise! If we
861 # hardcoded a value, it would have to change every time B::Concise or
862 # other modules we use do. To help a little, what we do here is compile
863 # a little code at the end of the module, and compute the base sequence
864 # number for the user's program as being a small offset later, so all we
865 # have to worry about are changes in the offset.
867 # [For 5.8.x and earlier perl is generating sequence numbers for all ops,
868 # and using them to reference labels]
871 # When you say "perl -MO=Concise -e '$a'", the output should look like:
873 # 4 <@> leave[t1] vKP/REFC ->(end)
875 #^ smallest OP sequence number should be 1
876 # 2 <;> nextstate(main 1 -e:1) v ->3
877 # ^ smallest COP sequence number should be 1
878 # - <1> ex-rv2sv vK/1 ->4
879 # 3 <$> gvsv(*a) s ->4
881 # If the second of the marked numbers there isn't 1, it means you need
882 # to update the corresponding magic number in the next line.
883 # Remember, this needs to stay the last things in the module.
885 # Why is this different for MacOS? Does it matter?
886 my $cop_seq_mnum = $^O eq 'MacOS' ? 12 : 11;
887 $cop_seq_base = svref_2object(eval 'sub{0;}')->START->cop_seq + $cop_seq_mnum;
895 B::Concise - Walk Perl syntax tree, printing concise info about ops
899 perl -MO=Concise[,OPTIONS] foo.pl
901 use B::Concise qw(set_style add_callback);
905 This compiler backend prints the internal OPs of a Perl program's syntax
906 tree in one of several space-efficient text formats suitable for debugging
907 the inner workings of perl or other compiler backends. It can print OPs in
908 the order they appear in the OP tree, in the order they will execute, or
909 in a text approximation to their tree structure, and the format of the
910 information displyed is customizable. Its function is similar to that of
911 perl's B<-Dx> debugging flag or the B<B::Terse> module, but it is more
912 sophisticated and flexible.
916 Here's is a short example of output (aka 'rendering'), using the
917 default formatting conventions :
919 % perl -MO=Concise -e '$a = $b + 42'
920 8 <@> leave[1 ref] vKP/REFC ->(end)
922 2 <;> nextstate(main 1 -e:1) v ->3
923 7 <2> sassign vKS/2 ->8
924 5 <2> add[t1] sK/2 ->6
925 - <1> ex-rv2sv sK/1 ->4
927 4 <$> const(IV 42) s ->5
928 - <1> ex-rv2sv sKRM*/1 ->7
931 Each line corresponds to an opcode. Null ops appear as C<ex-opname>,
932 where I<opname> is the op that has been optimized away by perl.
934 The number on the first row indicates the op's sequence number. It's
935 given in base 36 by default.
937 The symbol between angle brackets indicates the op's type : for example,
938 <2> is a BINOP, <@> a LISTOP, etc. (see L</"OP class abbreviations">).
940 The opname may be followed by op-specific information in parentheses
941 (e.g. C<gvsv(*b)>), and by targ information in brackets (e.g.
944 Next come the op flags. The common flags are listed below
945 (L</"OP flags abbreviations">). The private flags follow, separated
946 by a slash. For example, C<vKP/REFC> means that the leave op has
947 public flags OPf_WANT_VOID, OPf_KIDS, and OPf_PARENS, and the private
950 Finally an arrow points to the sequence number of the next op.
954 Arguments that don't start with a hyphen are taken to be the names of
955 subroutines to print the OPs of; if no such functions are specified,
956 the main body of the program (outside any subroutines, and not
957 including use'd or require'd files) is printed. Passing C<BEGIN>,
958 C<CHECK>, C<INIT>, or C<END> will cause all of the corresponding
959 special blocks to be printed.
961 Options affect how things are rendered (ie printed). They're presented
962 here by their visual effect, 1st being strongest. They're grouped
963 according to how they interrelate; within each group the options are
964 mutually exclusive (unless otherwise stated).
966 =head2 Options for Opcode Ordering
968 These options control the 'vertical display' of opcodes. The display
969 'order' is also called 'mode' elsewhere in this document.
975 Print OPs in the order they appear in the OP tree (a preorder
976 traversal, starting at the root). The indentation of each OP shows its
977 level in the tree. This mode is the default, so the flag is included
978 simply for completeness.
982 Print OPs in the order they would normally execute (for the majority
983 of constructs this is a postorder traversal of the tree, ending at the
984 root). In most cases the OP that usually follows a given OP will
985 appear directly below it; alternate paths are shown by indentation. In
986 cases like loops when control jumps out of a linear path, a 'goto'
991 Print OPs in a text approximation of a tree, with the root of the tree
992 at the left and 'left-to-right' order of children transformed into
993 'top-to-bottom'. Because this mode grows both to the right and down,
994 it isn't suitable for large programs (unless you have a very wide
999 =head2 Options for Line-Style
1001 These options select the line-style (or just style) used to render
1002 each opcode, and dictates what info is actually printed into each line.
1008 Use the author's favorite set of formatting conventions. This is the
1013 Use formatting conventions that emulate the output of B<B::Terse>. The
1014 basic mode is almost indistinguishable from the real B<B::Terse>, and the
1015 exec mode looks very similar, but is in a more logical order and lacks
1016 curly brackets. B<B::Terse> doesn't have a tree mode, so the tree mode
1017 is only vaguely reminiscent of B<B::Terse>.
1021 Use formatting conventions in which the name of each OP, rather than being
1022 written out in full, is represented by a one- or two-character abbreviation.
1023 This is mainly a joke.
1027 Use formatting conventions reminiscent of B<B::Debug>; these aren't
1028 very concise at all.
1032 Use formatting conventions read from the environment variables
1033 C<B_CONCISE_FORMAT>, C<B_CONCISE_GOTO_FORMAT>, and C<B_CONCISE_TREE_FORMAT>.
1037 =head2 Options for tree-specific formatting
1043 Use a tree format in which the minimum amount of space is used for the
1044 lines connecting nodes (one character in most cases). This squeezes out
1045 a few precious columns of screen real estate.
1049 Use a tree format that uses longer edges to separate OP nodes. This format
1050 tends to look better than the compact one, especially in ASCII, and is
1055 Use tree connecting characters drawn from the VT100 line-drawing set.
1056 This looks better if your terminal supports it.
1060 Draw the tree with standard ASCII characters like C<+> and C<|>. These don't
1061 look as clean as the VT100 characters, but they'll work with almost any
1062 terminal (or the horizontal scrolling mode of less(1)) and are suitable
1063 for text documentation or email. This is the default.
1067 These are pairwise exclusive, i.e. compact or loose, vt or ascii.
1069 =head2 Options controlling sequence numbering
1075 Print OP sequence numbers in base I<n>. If I<n> is greater than 10, the
1076 digit for 11 will be 'a', and so on. If I<n> is greater than 36, the digit
1077 for 37 will be 'A', and so on until 62. Values greater than 62 are not
1078 currently supported. The default is 36.
1082 Print sequence numbers with the most significant digit first. This is the
1083 usual convention for Arabic numerals, and the default.
1085 =item B<-littleendian>
1087 Print seqence numbers with the least significant digit first. This is
1088 obviously mutually exclusive with bigendian.
1092 =head2 Other options
1094 These are pairwise exclusive.
1100 Include the main program in the output, even if subroutines were also
1101 specified. This rendering is normally suppressed when a subroutine
1102 name or reference is given.
1106 This restores the default behavior after you've changed it with '-main'
1107 (it's not normally needed). If no subroutine name/ref is given, main is
1108 rendered, regardless of this flag.
1112 Renderings usually include a banner line identifying the function name
1113 or stringified subref. This suppresses the printing of the banner.
1115 TBC: Remove the stringified coderef; while it provides a 'cookie' for
1116 each function rendered, the cookies used should be 1,2,3.. not a
1117 random hex-address. It also complicates string comparison of two
1122 restores default banner behavior.
1124 =item B<-banneris> => subref
1126 TBC: a hookpoint (and an option to set it) for a user-supplied
1127 function to produce a banner appropriate for users needs. It's not
1128 ideal, because the rendering-state variables, which are a natural
1129 candidate for use in concise.t, are unavailable to the user.
1133 =head2 Option Stickiness
1135 If you invoke Concise more than once in a program, you should know that
1136 the options are 'sticky'. This means that the options you provide in
1137 the first call will be remembered for the 2nd call, unless you
1138 re-specify or change them.
1140 =head1 ABBREVIATIONS
1142 The concise style uses symbols to convey maximum info with minimal
1143 clutter (like hex addresses). With just a little practice, you can
1144 start to see the flowers, not just the branches, in the trees.
1146 =head2 OP class abbreviations
1148 These symbols appear before the op-name, and indicate the
1149 B:: namespace that represents the ops in your Perl code.
1151 0 OP (aka BASEOP) An OP with no children
1152 1 UNOP An OP with one child
1153 2 BINOP An OP with two children
1154 | LOGOP A control branch OP
1155 @ LISTOP An OP that could have lots of children
1156 / PMOP An OP with a regular expression
1157 $ SVOP An OP with an SV
1158 " PVOP An OP with a string
1159 { LOOP An OP that holds pointers for a loop
1160 ; COP An OP that marks the start of a statement
1161 # PADOP An OP with a GV on the pad
1163 =head2 OP flags abbreviations
1165 These symbols represent various flags which alter behavior of the
1166 opcode, sometimes in opcode-specific ways.
1168 v OPf_WANT_VOID Want nothing (void context)
1169 s OPf_WANT_SCALAR Want single value (scalar context)
1170 l OPf_WANT_LIST Want list of any length (list context)
1171 K OPf_KIDS There is a firstborn child.
1172 P OPf_PARENS This operator was parenthesized.
1173 (Or block needs explicit scope entry.)
1174 R OPf_REF Certified reference.
1175 (Return container, not containee).
1176 M OPf_MOD Will modify (lvalue).
1177 S OPf_STACKED Some arg is arriving on the stack.
1178 * OPf_SPECIAL Do something weird for this op (see op.h)
1180 =head1 FORMATTING SPECIFICATIONS
1182 For each line-style ('concise', 'terse', 'linenoise', etc.) there are
1183 3 format-specs which control how OPs are rendered.
1185 The first is the 'default' format, which is used in both basic and exec
1186 modes to print all opcodes. The 2nd, goto-format, is used in exec
1187 mode when branches are encountered. They're not real opcodes, and are
1188 inserted to look like a closing curly brace. The tree-format is tree
1191 When a line is rendered, the correct format-spec is copied and scanned
1192 for the following items; data is substituted in, and other
1193 manipulations like basic indenting are done, for each opcode rendered.
1195 There are 3 kinds of items that may be populated; special patterns,
1196 #vars, and literal text, which is copied verbatim. (Yes, it's a set
1199 =head2 Special Patterns
1201 These items are the primitives used to perform indenting, and to
1202 select text from amongst alternatives.
1206 =item B<(x(>I<exec_text>B<;>I<basic_text>B<)x)>
1208 Generates I<exec_text> in exec mode, or I<basic_text> in basic mode.
1210 =item B<(*(>I<text>B<)*)>
1212 Generates one copy of I<text> for each indentation level.
1214 =item B<(*(>I<text1>B<;>I<text2>B<)*)>
1216 Generates one fewer copies of I<text1> than the indentation level, followed
1217 by one copy of I<text2> if the indentation level is more than 0.
1219 =item B<(?(>I<text1>B<#>I<var>I<Text2>B<)?)>
1221 If the value of I<var> is true (not empty or zero), generates the
1222 value of I<var> surrounded by I<text1> and I<Text2>, otherwise
1227 Any number of tildes and surrounding whitespace will be collapsed to
1234 These #vars represent opcode properties that you may want as part of
1235 your rendering. The '#' is intended as a private sigil; a #var's
1236 value is interpolated into the style-line, much like "read $this".
1238 These vars take 3 forms:
1244 A property named 'var' is assumed to exist for the opcodes, and is
1245 interpolated into the rendering.
1247 =item B<#>I<var>I<N>
1249 Generates the value of I<var>, left justified to fill I<N> spaces.
1250 Note that this means while you can have properties 'foo' and 'foo2',
1251 you cannot render 'foo2', but you could with 'foo2a'. You would be
1252 wise not to rely on this behavior going forward ;-)
1256 This ucfirst form of #var generates a tag-value form of itself for
1257 display; it converts '#Var' into a 'Var => #var' style, which is then
1258 handled as described above. (Imp-note: #Vars cannot be used for
1259 conditional-fills, because the => #var transform is done after the check
1264 The following variables are 'defined' by B::Concise; when they are
1265 used in a style, their respective values are plugged into the
1266 rendering of each opcode.
1268 Only some of these are used by the standard styles, the others are
1269 provided for you to delve into optree mechanics, should you wish to
1270 add a new style (see L</add_style> below) that uses them. You can
1271 also add new ones using L<add_callback>.
1277 The address of the OP, in hexadecimal.
1281 The OP-specific information of the OP (such as the SV for an SVOP, the
1282 non-local exit pointers for a LOOP, etc.) enclosed in parentheses.
1286 The B-determined class of the OP, in all caps.
1290 A single symbol abbreviating the class of the OP.
1294 The label of the statement or block the OP is the start of, if any.
1298 The name of the OP, or 'ex-foo' if the OP is a null that used to be a foo.
1302 The target of the OP, or nothing for a nulled OP.
1306 The address of the OP's first child, in hexidecimal.
1310 The OP's flags, abbreviated as a series of symbols.
1314 The numeric value of the OP's flags.
1318 The sequence number of the OP, or a hyphen if it doesn't have one.
1322 'NEXT', 'LAST', or 'REDO' if the OP is a target of one of those in exec
1323 mode, or empty otherwise.
1327 The address of the OP's last child, in hexidecimal.
1335 The OP's name, in all caps.
1339 The sequence number of the OP's next OP.
1343 The address of the OP's next OP, in hexidecimal.
1347 A one- or two-character abbreviation for the OP's name.
1351 The OP's private flags, rendered with abbreviated names if possible.
1355 The numeric value of the OP's private flags.
1359 The sequence number of the OP. Note that this is a sequence number
1360 generated by B::Concise.
1364 5.8.x and earlier only. 5.9 and later do not provide this.
1366 The real sequence number of the OP, as a regular number and not adjusted
1367 to be relative to the start of the real program. (This will generally be
1368 a fairly large number because all of B<B::Concise> is compiled before
1373 Whether or not the op has been optimised by the peephole optimiser.
1375 Only available in 5.9 and later.
1379 Whether or not the op is statically defined. This flag is used by the
1380 B::C compiler backend and indicates that the op should not be freed.
1382 Only available in 5.9 and later.
1386 The address of the OP's next youngest sibling, in hexidecimal.
1390 The address of the OP's SV, if it has an SV, in hexidecimal.
1394 The class of the OP's SV, if it has one, in all caps (e.g., 'IV').
1398 The value of the OP's SV, if it has one, in a short human-readable format.
1402 The numeric value of the OP's targ.
1406 The name of the variable the OP's targ refers to, if any, otherwise the
1407 letter t followed by the OP's targ in decimal.
1409 =item B<#targarglife>
1411 Same as B<#targarg>, but followed by the COP sequence numbers that delimit
1412 the variable's lifetime (or 'end' for a variable in an open scope) for a
1417 The numeric value of the OP's type, in decimal.
1421 =head1 Using B::Concise outside of the O framework
1423 The common (and original) usage of B::Concise was for command-line
1424 renderings of simple code, as given in EXAMPLE. But you can also use
1425 B<B::Concise> from your code, and call compile() directly, and
1426 repeatedly. By doing so, you can avoid the compile-time only
1427 operation of O.pm, and even use the debugger to step through
1428 B::Concise::compile() itself.
1430 Once you're doing this, you may alter Concise output by adding new
1431 rendering styles, and by optionally adding callback routines which
1432 populate new variables, if such were referenced from those (just
1435 =head2 Example: Altering Concise Renderings
1437 use B::Concise qw(set_style add_callback);
1438 add_style($yourStyleName => $defaultfmt, $gotofmt, $treefmt);
1441 my ($h, $op, $format, $level, $stylename) = @_;
1442 $h->{variable} = some_func($op);
1444 $walker = B::Concise::compile(@options,@subnames,@subrefs);
1449 B<set_style> accepts 3 arguments, and updates the three format-specs
1450 comprising a line-style (basic-exec, goto, tree). It has one minor
1451 drawback though; it doesn't register the style under a new name. This
1452 can become an issue if you render more than once and switch styles.
1453 Thus you may prefer to use add_style() and/or set_style_standard()
1456 =head2 set_style_standard($name)
1458 This restores one of the standard line-styles: C<terse>, C<concise>,
1459 C<linenoise>, C<debug>, C<env>, into effect. It also accepts style
1460 names previously defined with add_style().
1464 This subroutine accepts a new style name and three style arguments as
1465 above, and creates, registers, and selects the newly named style. It is
1466 an error to re-add a style; call set_style_standard() to switch between
1469 =head2 add_callback()
1471 If your newly minted styles refer to any #variables, you'll need to
1472 define a callback subroutine that will populate (or modify) those
1473 variables. They are then available for use in the style you've chosen.
1475 The callbacks are called for each opcode visited by Concise, in the
1476 same order as they are added. Each subroutine is passed five
1479 1. A hashref, containing the variable names and values which are
1480 populated into the report-line for the op
1481 2. the op, as a B<B::OP> object
1482 3. a reference to the format string
1483 4. the formatting (indent) level
1484 5. the selected stylename
1486 To define your own variables, simply add them to the hash, or change
1487 existing values if you need to. The level and format are passed in as
1488 references to scalars, but it is unlikely that they will need to be
1489 changed or even used.
1491 =head2 Running B::Concise::compile()
1493 B<compile> accepts options as described above in L</OPTIONS>, and
1494 arguments, which are either coderefs, or subroutine names.
1496 It constructs and returns a $treewalker coderef, which when invoked,
1497 traverses, or walks, and renders the optrees of the given arguments to
1498 STDOUT. You can reuse this, and can change the rendering style used
1499 each time; thereafter the coderef renders in the new style.
1501 B<walk_output> lets you change the print destination from STDOUT to
1502 another open filehandle, or (unless you've built with -Uuseperlio)
1503 into a string passed as a ref.
1505 my $walker = B::Concise::compile('-terse','aFuncName', \&aSubRef); # 1
1506 walk_output(\my $buf);
1507 $walker->(); # 1 renders -terse
1508 set_style_standard('concise'); # 2
1509 $walker->(); # 2 renders -concise
1510 $walker->(@new); # 3 renders whatever
1511 print "3 different renderings: terse, concise, and @new: $buf\n";
1513 When $walker is called, it traverses the subroutines supplied when it
1514 was created, and renders them using the current style. You can change
1515 the style afterwards in several different ways:
1517 1. call C<compile>, altering style or mode/order
1518 2. call C<set_style_standard>
1519 3. call $walker, passing @new options
1521 Passing new options to the $walker is the easiest way to change
1522 amongst any pre-defined styles (the ones you add are automatically
1523 recognized as options), and is the only way to alter rendering order
1524 without calling compile again. Note however that rendering state is
1525 still shared amongst multiple $walker objects, so they must still be
1526 used in a coordinated manner.
1528 =head2 B::Concise::reset_sequence()
1530 This function (not exported) lets you reset the sequence numbers (note
1531 that they're numbered arbitrarily, their goal being to be human
1532 readable). Its purpose is mostly to support testing, i.e. to compare
1533 the concise output from two identical anonymous subroutines (but
1534 different instances). Without the reset, B::Concise, seeing that
1535 they're separate optrees, generates different sequence numbers in
1540 All detected errors, (invalid arguments, internal errors, etc.) are
1541 resolved with a die($message). Use an eval if you wish to catch these
1542 errors and continue processing.
1544 In particular, B<compile> will die if you've asked for a non-existent
1545 function-name, a non-existent coderef, or a non-CODE reference.
1549 Stephen McCamant, E<lt>smcc@CSUA.Berkeley.EDUE<gt>.