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1 | package B::Xref; |
2 | |
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3 | our $VERSION = '1.01'; |
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4 | |
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5 | =head1 NAME |
6 | |
7 | B::Xref - Generates cross reference reports for Perl programs |
8 | |
9 | =head1 SYNOPSIS |
10 | |
11 | perl -MO=Xref[,OPTIONS] foo.pl |
12 | |
13 | =head1 DESCRIPTION |
14 | |
15 | The B::Xref module is used to generate a cross reference listing of all |
16 | definitions and uses of variables, subroutines and formats in a Perl program. |
17 | It is implemented as a backend for the Perl compiler. |
18 | |
19 | The report generated is in the following format: |
20 | |
21 | File filename1 |
22 | Subroutine subname1 |
23 | Package package1 |
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24 | object1 line numbers |
25 | object2 line numbers |
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26 | ... |
27 | Package package2 |
28 | ... |
29 | |
30 | Each B<File> section reports on a single file. Each B<Subroutine> section |
31 | reports on a single subroutine apart from the special cases |
32 | "(definitions)" and "(main)". These report, respectively, on subroutine |
33 | definitions found by the initial symbol table walk and on the main part of |
34 | the program or module external to all subroutines. |
35 | |
36 | The report is then grouped by the B<Package> of each variable, |
37 | subroutine or format with the special case "(lexicals)" meaning |
38 | lexical variables. Each B<object> name (implicitly qualified by its |
39 | containing B<Package>) includes its type character(s) at the beginning |
40 | where possible. Lexical variables are easier to track and even |
41 | included dereferencing information where possible. |
42 | |
43 | The C<line numbers> are a comma separated list of line numbers (some |
44 | preceded by code letters) where that object is used in some way. |
45 | Simple uses aren't preceded by a code letter. Introductions (such as |
46 | where a lexical is first defined with C<my>) are indicated with the |
47 | letter "i". Subroutine and method calls are indicated by the character |
48 | "&". Subroutine definitions are indicated by "s" and format |
49 | definitions by "f". |
50 | |
51 | =head1 OPTIONS |
52 | |
53 | Option words are separated by commas (not whitespace) and follow the |
54 | usual conventions of compiler backend options. |
55 | |
56 | =over 8 |
57 | |
58 | =item C<-oFILENAME> |
59 | |
60 | Directs output to C<FILENAME> instead of standard output. |
61 | |
62 | =item C<-r> |
63 | |
64 | Raw output. Instead of producing a human-readable report, outputs a line |
65 | in machine-readable form for each definition/use of a variable/sub/format. |
66 | |
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67 | =item C<-d> |
68 | |
69 | Don't output the "(definitions)" sections. |
70 | |
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71 | =item C<-D[tO]> |
72 | |
73 | (Internal) debug options, probably only useful if C<-r> included. |
74 | The C<t> option prints the object on the top of the stack as it's |
75 | being tracked. The C<O> option prints each operator as it's being |
76 | processed in the execution order of the program. |
77 | |
78 | =back |
79 | |
80 | =head1 BUGS |
81 | |
82 | Non-lexical variables are quite difficult to track through a program. |
83 | Sometimes the type of a non-lexical variable's use is impossible to |
84 | determine. Introductions of non-lexical non-scalars don't seem to be |
85 | reported properly. |
86 | |
87 | =head1 AUTHOR |
88 | |
89 | Malcolm Beattie, mbeattie@sable.ox.ac.uk. |
90 | |
91 | =cut |
92 | |
93 | use strict; |
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94 | use Config; |
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95 | use B qw(peekop class comppadlist main_start svref_2object walksymtable |
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96 | OPpLVAL_INTRO SVf_POK OPpOUR_INTRO cstring |
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97 | ); |
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98 | |
99 | sub UNKNOWN { ["?", "?", "?"] } |
100 | |
101 | my @pad; # lexicals in current pad |
102 | # as ["(lexical)", type, name] |
103 | my %done; # keyed by $$op: set when each $op is done |
104 | my $top = UNKNOWN; # shadows top element of stack as |
105 | # [pack, type, name] (pack can be "(lexical)") |
106 | my $file; # shadows current filename |
107 | my $line; # shadows current line number |
108 | my $subname; # shadows current sub name |
109 | my %table; # Multi-level hash to record all uses etc. |
110 | my @todo = (); # List of CVs that need processing |
111 | |
112 | my %code = (intro => "i", used => "", |
113 | subdef => "s", subused => "&", |
114 | formdef => "f", meth => "->"); |
115 | |
116 | |
117 | # Options |
118 | my ($debug_op, $debug_top, $nodefs, $raw); |
119 | |
120 | sub process { |
121 | my ($var, $event) = @_; |
122 | my ($pack, $type, $name) = @$var; |
123 | if ($type eq "*") { |
124 | if ($event eq "used") { |
125 | return; |
126 | } elsif ($event eq "subused") { |
127 | $type = "&"; |
128 | } |
129 | } |
130 | $type =~ s/(.)\*$/$1/g; |
131 | if ($raw) { |
132 | printf "%-16s %-12s %5d %-12s %4s %-16s %s\n", |
133 | $file, $subname, $line, $pack, $type, $name, $event; |
134 | } else { |
135 | # Wheee |
136 | push(@{$table{$file}->{$subname}->{$pack}->{$type.$name}->{$event}}, |
137 | $line); |
138 | } |
139 | } |
140 | |
141 | sub load_pad { |
142 | my $padlist = shift; |
18228111 |
143 | my ($namelistav, $vallistav, @namelist, $ix); |
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144 | @pad = (); |
145 | return if class($padlist) eq "SPECIAL"; |
18228111 |
146 | ($namelistav,$vallistav) = $padlist->ARRAY; |
a798dbf2 |
147 | @namelist = $namelistav->ARRAY; |
148 | for ($ix = 1; $ix < @namelist; $ix++) { |
149 | my $namesv = $namelist[$ix]; |
150 | next if class($namesv) eq "SPECIAL"; |
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151 | my ($type, $name) = $namesv->PV =~ /^(.)([^\0]*)(\0.*)?$/; |
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152 | $pad[$ix] = ["(lexical)", $type || '?', $name || '?']; |
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153 | } |
18228111 |
154 | if ($Config{useithreads}) { |
155 | my (@vallist); |
156 | @vallist = $vallistav->ARRAY; |
157 | for ($ix = 1; $ix < @vallist; $ix++) { |
158 | my $valsv = $vallist[$ix]; |
159 | next unless class($valsv) eq "GV"; |
160 | # these pad GVs don't have corresponding names, so same @pad |
161 | # array can be used without collisions |
162 | $pad[$ix] = [$valsv->STASH->NAME, "*", $valsv->NAME]; |
163 | } |
164 | } |
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165 | } |
166 | |
167 | sub xref { |
168 | my $start = shift; |
169 | my $op; |
170 | for ($op = $start; $$op; $op = $op->next) { |
171 | last if $done{$$op}++; |
172 | warn sprintf("top = [%s, %s, %s]\n", @$top) if $debug_top; |
173 | warn peekop($op), "\n" if $debug_op; |
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174 | my $opname = $op->name; |
175 | if ($opname =~ /^(or|and|mapwhile|grepwhile|range|cond_expr)$/) { |
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176 | xref($op->other); |
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177 | } elsif ($opname eq "match" || $opname eq "subst") { |
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178 | xref($op->pmreplstart); |
3f872cb9 |
179 | } elsif ($opname eq "substcont") { |
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180 | xref($op->other->pmreplstart); |
181 | $op = $op->other; |
182 | redo; |
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183 | } elsif ($opname eq "enterloop") { |
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184 | xref($op->redoop); |
185 | xref($op->nextop); |
186 | xref($op->lastop); |
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187 | } elsif ($opname eq "subst") { |
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188 | xref($op->pmreplstart); |
189 | } else { |
190 | no strict 'refs'; |
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191 | my $ppname = "pp_$opname"; |
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192 | &$ppname($op) if defined(&$ppname); |
193 | } |
194 | } |
195 | } |
196 | |
197 | sub xref_cv { |
198 | my $cv = shift; |
199 | my $pack = $cv->GV->STASH->NAME; |
200 | $subname = ($pack eq "main" ? "" : "$pack\::") . $cv->GV->NAME; |
201 | load_pad($cv->PADLIST); |
202 | xref($cv->START); |
203 | $subname = "(main)"; |
204 | } |
205 | |
206 | sub xref_object { |
207 | my $cvref = shift; |
208 | xref_cv(svref_2object($cvref)); |
209 | } |
210 | |
211 | sub xref_main { |
212 | $subname = "(main)"; |
213 | load_pad(comppadlist); |
214 | xref(main_start); |
215 | while (@todo) { |
216 | xref_cv(shift @todo); |
217 | } |
218 | } |
219 | |
220 | sub pp_nextstate { |
221 | my $op = shift; |
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222 | $file = $op->file; |
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223 | $line = $op->line; |
224 | $top = UNKNOWN; |
225 | } |
226 | |
227 | sub pp_padsv { |
228 | my $op = shift; |
229 | $top = $pad[$op->targ]; |
230 | process($top, $op->private & OPpLVAL_INTRO ? "intro" : "used"); |
231 | } |
232 | |
233 | sub pp_padav { pp_padsv(@_) } |
234 | sub pp_padhv { pp_padsv(@_) } |
235 | |
236 | sub deref { |
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237 | my ($op, $var, $as) = @_; |
a798dbf2 |
238 | $var->[1] = $as . $var->[1]; |
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239 | process($var, $op->private & OPpOUR_INTRO ? "intro" : "used"); |
a798dbf2 |
240 | } |
241 | |
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242 | sub pp_rv2cv { deref(shift, $top, "&"); } |
243 | sub pp_rv2hv { deref(shift, $top, "%"); } |
244 | sub pp_rv2sv { deref(shift, $top, "\$"); } |
245 | sub pp_rv2av { deref(shift, $top, "\@"); } |
246 | sub pp_rv2gv { deref(shift, $top, "*"); } |
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247 | |
248 | sub pp_gvsv { |
249 | my $op = shift; |
18228111 |
250 | my $gv; |
251 | if ($Config{useithreads}) { |
252 | $top = $pad[$op->padix]; |
253 | $top = UNKNOWN unless $top; |
254 | $top->[1] = '$'; |
255 | } |
256 | else { |
257 | $gv = $op->gv; |
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258 | $top = [$gv->STASH->NAME, '$', $gv->SAFENAME]; |
18228111 |
259 | } |
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260 | process($top, $op->private & OPpLVAL_INTRO || |
261 | $op->private & OPpOUR_INTRO ? "intro" : "used"); |
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262 | } |
263 | |
264 | sub pp_gv { |
265 | my $op = shift; |
18228111 |
266 | my $gv; |
267 | if ($Config{useithreads}) { |
268 | $top = $pad[$op->padix]; |
269 | $top = UNKNOWN unless $top; |
270 | $top->[1] = '*'; |
271 | } |
272 | else { |
273 | $gv = $op->gv; |
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274 | $top = [$gv->STASH->NAME, "*", $gv->SAFENAME]; |
18228111 |
275 | } |
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276 | process($top, $op->private & OPpLVAL_INTRO ? "intro" : "used"); |
277 | } |
278 | |
279 | sub pp_const { |
280 | my $op = shift; |
281 | my $sv = $op->sv; |
18228111 |
282 | # constant could be in the pad (under useithreads) |
283 | if ($$sv) { |
284 | $top = ["?", "", |
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285 | (class($sv) ne "SPECIAL" && $sv->FLAGS & SVf_POK) |
286 | ? cstring($sv->PV) : "?"]; |
18228111 |
287 | } |
288 | else { |
289 | $top = $pad[$op->targ]; |
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290 | $top = UNKNOWN unless $top; |
18228111 |
291 | } |
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292 | } |
293 | |
294 | sub pp_method { |
295 | my $op = shift; |
296 | $top = ["(method)", "->".$top->[1], $top->[2]]; |
297 | } |
298 | |
299 | sub pp_entersub { |
300 | my $op = shift; |
301 | if ($top->[1] eq "m") { |
302 | process($top, "meth"); |
303 | } else { |
304 | process($top, "subused"); |
305 | } |
306 | $top = UNKNOWN; |
307 | } |
308 | |
309 | # |
310 | # Stuff for cross referencing definitions of variables and subs |
311 | # |
312 | |
313 | sub B::GV::xref { |
314 | my $gv = shift; |
315 | my $cv = $gv->CV; |
316 | if ($$cv) { |
317 | #return if $done{$$cv}++; |
b195d487 |
318 | $file = $gv->FILE; |
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319 | $line = $gv->LINE; |
320 | process([$gv->STASH->NAME, "&", $gv->NAME], "subdef"); |
321 | push(@todo, $cv); |
322 | } |
323 | my $form = $gv->FORM; |
324 | if ($$form) { |
325 | return if $done{$$form}++; |
b195d487 |
326 | $file = $gv->FILE; |
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327 | $line = $gv->LINE; |
328 | process([$gv->STASH->NAME, "", $gv->NAME], "formdef"); |
329 | } |
330 | } |
331 | |
332 | sub xref_definitions { |
333 | my ($pack, %exclude); |
334 | return if $nodefs; |
335 | $subname = "(definitions)"; |
595f3c5f |
336 | foreach $pack (qw(B O AutoLoader DynaLoader XSLoader Config DB VMS |
586b0d7d |
337 | strict vars FileHandle Exporter Carp PerlIO::Layer |
338 | attributes utf8 warnings)) { |
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339 | $exclude{$pack."::"} = 1; |
340 | } |
341 | no strict qw(vars refs); |
342 | walksymtable(\%{"main::"}, "xref", sub { !defined($exclude{$_[0]}) }); |
343 | } |
344 | |
345 | sub output { |
346 | return if $raw; |
347 | my ($file, $subname, $pack, $name, $ev, $perfile, $persubname, |
348 | $perpack, $pername, $perev); |
349 | foreach $file (sort(keys(%table))) { |
350 | $perfile = $table{$file}; |
351 | print "File $file\n"; |
352 | foreach $subname (sort(keys(%$perfile))) { |
353 | $persubname = $perfile->{$subname}; |
354 | print " Subroutine $subname\n"; |
355 | foreach $pack (sort(keys(%$persubname))) { |
356 | $perpack = $persubname->{$pack}; |
357 | print " Package $pack\n"; |
358 | foreach $name (sort(keys(%$perpack))) { |
359 | $pername = $perpack->{$name}; |
360 | my @lines; |
361 | foreach $ev (qw(intro formdef subdef meth subused used)) { |
362 | $perev = $pername->{$ev}; |
363 | if (defined($perev) && @$perev) { |
364 | my $code = $code{$ev}; |
365 | push(@lines, map("$code$_", @$perev)); |
366 | } |
367 | } |
368 | printf " %-16s %s\n", $name, join(", ", @lines); |
369 | } |
370 | } |
371 | } |
372 | } |
373 | } |
374 | |
375 | sub compile { |
376 | my @options = @_; |
377 | my ($option, $opt, $arg); |
378 | OPTION: |
379 | while ($option = shift @options) { |
380 | if ($option =~ /^-(.)(.*)/) { |
381 | $opt = $1; |
382 | $arg = $2; |
383 | } else { |
384 | unshift @options, $option; |
385 | last OPTION; |
386 | } |
387 | if ($opt eq "-" && $arg eq "-") { |
388 | shift @options; |
389 | last OPTION; |
390 | } elsif ($opt eq "o") { |
391 | $arg ||= shift @options; |
392 | open(STDOUT, ">$arg") or return "$arg: $!\n"; |
393 | } elsif ($opt eq "d") { |
394 | $nodefs = 1; |
395 | } elsif ($opt eq "r") { |
396 | $raw = 1; |
397 | } elsif ($opt eq "D") { |
398 | $arg ||= shift @options; |
399 | foreach $arg (split(//, $arg)) { |
400 | if ($arg eq "o") { |
401 | B->debug(1); |
402 | } elsif ($arg eq "O") { |
403 | $debug_op = 1; |
404 | } elsif ($arg eq "t") { |
405 | $debug_top = 1; |
406 | } |
407 | } |
408 | } |
409 | } |
410 | if (@options) { |
411 | return sub { |
412 | my $objname; |
413 | xref_definitions(); |
414 | foreach $objname (@options) { |
415 | $objname = "main::$objname" unless $objname =~ /::/; |
416 | eval "xref_object(\\&$objname)"; |
417 | die "xref_object(\\&$objname) failed: $@" if $@; |
418 | } |
419 | output(); |
420 | } |
421 | } else { |
422 | return sub { |
423 | xref_definitions(); |
424 | xref_main(); |
425 | output(); |
426 | } |
427 | } |
428 | } |
429 | |
430 | 1; |