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a798dbf2 |
1 | package B::Xref; |
2 | |
3 | =head1 NAME |
4 | |
5 | B::Xref - Generates cross reference reports for Perl programs |
6 | |
7 | =head1 SYNOPSIS |
8 | |
9 | perl -MO=Xref[,OPTIONS] foo.pl |
10 | |
11 | =head1 DESCRIPTION |
12 | |
13 | The B::Xref module is used to generate a cross reference listing of all |
14 | definitions and uses of variables, subroutines and formats in a Perl program. |
15 | It is implemented as a backend for the Perl compiler. |
16 | |
17 | The report generated is in the following format: |
18 | |
19 | File filename1 |
20 | Subroutine subname1 |
21 | Package package1 |
22 | object1 C<line numbers> |
23 | object2 C<line numbers> |
24 | ... |
25 | Package package2 |
26 | ... |
27 | |
28 | Each B<File> section reports on a single file. Each B<Subroutine> section |
29 | reports on a single subroutine apart from the special cases |
30 | "(definitions)" and "(main)". These report, respectively, on subroutine |
31 | definitions found by the initial symbol table walk and on the main part of |
32 | the program or module external to all subroutines. |
33 | |
34 | The report is then grouped by the B<Package> of each variable, |
35 | subroutine or format with the special case "(lexicals)" meaning |
36 | lexical variables. Each B<object> name (implicitly qualified by its |
37 | containing B<Package>) includes its type character(s) at the beginning |
38 | where possible. Lexical variables are easier to track and even |
39 | included dereferencing information where possible. |
40 | |
41 | The C<line numbers> are a comma separated list of line numbers (some |
42 | preceded by code letters) where that object is used in some way. |
43 | Simple uses aren't preceded by a code letter. Introductions (such as |
44 | where a lexical is first defined with C<my>) are indicated with the |
45 | letter "i". Subroutine and method calls are indicated by the character |
46 | "&". Subroutine definitions are indicated by "s" and format |
47 | definitions by "f". |
48 | |
49 | =head1 OPTIONS |
50 | |
51 | Option words are separated by commas (not whitespace) and follow the |
52 | usual conventions of compiler backend options. |
53 | |
54 | =over 8 |
55 | |
56 | =item C<-oFILENAME> |
57 | |
58 | Directs output to C<FILENAME> instead of standard output. |
59 | |
60 | =item C<-r> |
61 | |
62 | Raw output. Instead of producing a human-readable report, outputs a line |
63 | in machine-readable form for each definition/use of a variable/sub/format. |
64 | |
65 | =item C<-D[tO]> |
66 | |
67 | (Internal) debug options, probably only useful if C<-r> included. |
68 | The C<t> option prints the object on the top of the stack as it's |
69 | being tracked. The C<O> option prints each operator as it's being |
70 | processed in the execution order of the program. |
71 | |
72 | =back |
73 | |
74 | =head1 BUGS |
75 | |
76 | Non-lexical variables are quite difficult to track through a program. |
77 | Sometimes the type of a non-lexical variable's use is impossible to |
78 | determine. Introductions of non-lexical non-scalars don't seem to be |
79 | reported properly. |
80 | |
81 | =head1 AUTHOR |
82 | |
83 | Malcolm Beattie, mbeattie@sable.ox.ac.uk. |
84 | |
85 | =cut |
86 | |
87 | use strict; |
18228111 |
88 | use Config; |
4c1f658f |
89 | use B qw(peekop class comppadlist main_start svref_2object walksymtable |
90 | OPpLVAL_INTRO SVf_POK |
91 | ); |
a798dbf2 |
92 | |
93 | sub UNKNOWN { ["?", "?", "?"] } |
94 | |
95 | my @pad; # lexicals in current pad |
96 | # as ["(lexical)", type, name] |
97 | my %done; # keyed by $$op: set when each $op is done |
98 | my $top = UNKNOWN; # shadows top element of stack as |
99 | # [pack, type, name] (pack can be "(lexical)") |
100 | my $file; # shadows current filename |
101 | my $line; # shadows current line number |
102 | my $subname; # shadows current sub name |
103 | my %table; # Multi-level hash to record all uses etc. |
104 | my @todo = (); # List of CVs that need processing |
105 | |
106 | my %code = (intro => "i", used => "", |
107 | subdef => "s", subused => "&", |
108 | formdef => "f", meth => "->"); |
109 | |
110 | |
111 | # Options |
112 | my ($debug_op, $debug_top, $nodefs, $raw); |
113 | |
114 | sub process { |
115 | my ($var, $event) = @_; |
116 | my ($pack, $type, $name) = @$var; |
117 | if ($type eq "*") { |
118 | if ($event eq "used") { |
119 | return; |
120 | } elsif ($event eq "subused") { |
121 | $type = "&"; |
122 | } |
123 | } |
124 | $type =~ s/(.)\*$/$1/g; |
125 | if ($raw) { |
126 | printf "%-16s %-12s %5d %-12s %4s %-16s %s\n", |
127 | $file, $subname, $line, $pack, $type, $name, $event; |
128 | } else { |
129 | # Wheee |
130 | push(@{$table{$file}->{$subname}->{$pack}->{$type.$name}->{$event}}, |
131 | $line); |
132 | } |
133 | } |
134 | |
135 | sub load_pad { |
136 | my $padlist = shift; |
18228111 |
137 | my ($namelistav, $vallistav, @namelist, $ix); |
a798dbf2 |
138 | @pad = (); |
139 | return if class($padlist) eq "SPECIAL"; |
18228111 |
140 | ($namelistav,$vallistav) = $padlist->ARRAY; |
a798dbf2 |
141 | @namelist = $namelistav->ARRAY; |
142 | for ($ix = 1; $ix < @namelist; $ix++) { |
143 | my $namesv = $namelist[$ix]; |
144 | next if class($namesv) eq "SPECIAL"; |
51e5a3db |
145 | my ($type, $name) = $namesv->PV =~ /^(.)([^\0]*)(\0.*)?$/; |
a798dbf2 |
146 | $pad[$ix] = ["(lexical)", $type, $name]; |
147 | } |
18228111 |
148 | if ($Config{useithreads}) { |
149 | my (@vallist); |
150 | @vallist = $vallistav->ARRAY; |
151 | for ($ix = 1; $ix < @vallist; $ix++) { |
152 | my $valsv = $vallist[$ix]; |
153 | next unless class($valsv) eq "GV"; |
154 | # these pad GVs don't have corresponding names, so same @pad |
155 | # array can be used without collisions |
156 | $pad[$ix] = [$valsv->STASH->NAME, "*", $valsv->NAME]; |
157 | } |
158 | } |
a798dbf2 |
159 | } |
160 | |
161 | sub xref { |
162 | my $start = shift; |
163 | my $op; |
164 | for ($op = $start; $$op; $op = $op->next) { |
165 | last if $done{$$op}++; |
166 | warn sprintf("top = [%s, %s, %s]\n", @$top) if $debug_top; |
167 | warn peekop($op), "\n" if $debug_op; |
3f872cb9 |
168 | my $opname = $op->name; |
169 | if ($opname =~ /^(or|and|mapwhile|grepwhile|range|cond_expr)$/) { |
a798dbf2 |
170 | xref($op->other); |
3f872cb9 |
171 | } elsif ($opname eq "match" || $opname eq "subst") { |
a798dbf2 |
172 | xref($op->pmreplstart); |
3f872cb9 |
173 | } elsif ($opname eq "substcont") { |
a798dbf2 |
174 | xref($op->other->pmreplstart); |
175 | $op = $op->other; |
176 | redo; |
3f872cb9 |
177 | } elsif ($opname eq "enterloop") { |
a798dbf2 |
178 | xref($op->redoop); |
179 | xref($op->nextop); |
180 | xref($op->lastop); |
3f872cb9 |
181 | } elsif ($opname eq "subst") { |
a798dbf2 |
182 | xref($op->pmreplstart); |
183 | } else { |
184 | no strict 'refs'; |
3f872cb9 |
185 | my $ppname = "pp_$opname"; |
a798dbf2 |
186 | &$ppname($op) if defined(&$ppname); |
187 | } |
188 | } |
189 | } |
190 | |
191 | sub xref_cv { |
192 | my $cv = shift; |
193 | my $pack = $cv->GV->STASH->NAME; |
194 | $subname = ($pack eq "main" ? "" : "$pack\::") . $cv->GV->NAME; |
195 | load_pad($cv->PADLIST); |
196 | xref($cv->START); |
197 | $subname = "(main)"; |
198 | } |
199 | |
200 | sub xref_object { |
201 | my $cvref = shift; |
202 | xref_cv(svref_2object($cvref)); |
203 | } |
204 | |
205 | sub xref_main { |
206 | $subname = "(main)"; |
207 | load_pad(comppadlist); |
208 | xref(main_start); |
209 | while (@todo) { |
210 | xref_cv(shift @todo); |
211 | } |
212 | } |
213 | |
214 | sub pp_nextstate { |
215 | my $op = shift; |
57843af0 |
216 | $file = $op->file; |
a798dbf2 |
217 | $line = $op->line; |
218 | $top = UNKNOWN; |
219 | } |
220 | |
221 | sub pp_padsv { |
222 | my $op = shift; |
223 | $top = $pad[$op->targ]; |
224 | process($top, $op->private & OPpLVAL_INTRO ? "intro" : "used"); |
225 | } |
226 | |
227 | sub pp_padav { pp_padsv(@_) } |
228 | sub pp_padhv { pp_padsv(@_) } |
229 | |
230 | sub deref { |
231 | my ($var, $as) = @_; |
232 | $var->[1] = $as . $var->[1]; |
233 | process($var, "used"); |
234 | } |
235 | |
236 | sub pp_rv2cv { deref($top, "&"); } |
237 | sub pp_rv2hv { deref($top, "%"); } |
238 | sub pp_rv2sv { deref($top, "\$"); } |
239 | sub pp_rv2av { deref($top, "\@"); } |
240 | sub pp_rv2gv { deref($top, "*"); } |
241 | |
242 | sub pp_gvsv { |
243 | my $op = shift; |
18228111 |
244 | my $gv; |
245 | if ($Config{useithreads}) { |
246 | $top = $pad[$op->padix]; |
247 | $top = UNKNOWN unless $top; |
248 | $top->[1] = '$'; |
249 | } |
250 | else { |
251 | $gv = $op->gv; |
252 | $top = [$gv->STASH->NAME, '$', $gv->NAME]; |
253 | } |
a798dbf2 |
254 | process($top, $op->private & OPpLVAL_INTRO ? "intro" : "used"); |
255 | } |
256 | |
257 | sub pp_gv { |
258 | my $op = shift; |
18228111 |
259 | my $gv; |
260 | if ($Config{useithreads}) { |
261 | $top = $pad[$op->padix]; |
262 | $top = UNKNOWN unless $top; |
263 | $top->[1] = '*'; |
264 | } |
265 | else { |
266 | $gv = $op->gv; |
267 | $top = [$gv->STASH->NAME, "*", $gv->NAME]; |
268 | } |
a798dbf2 |
269 | process($top, $op->private & OPpLVAL_INTRO ? "intro" : "used"); |
270 | } |
271 | |
272 | sub pp_const { |
273 | my $op = shift; |
274 | my $sv = $op->sv; |
18228111 |
275 | # constant could be in the pad (under useithreads) |
276 | if ($$sv) { |
277 | $top = ["?", "", |
278 | (class($sv) ne "SPECIAL" && $sv->FLAGS & SVf_POK) ? $sv->PV : "?"]; |
279 | } |
280 | else { |
281 | $top = $pad[$op->targ]; |
282 | } |
a798dbf2 |
283 | } |
284 | |
285 | sub pp_method { |
286 | my $op = shift; |
287 | $top = ["(method)", "->".$top->[1], $top->[2]]; |
288 | } |
289 | |
290 | sub pp_entersub { |
291 | my $op = shift; |
292 | if ($top->[1] eq "m") { |
293 | process($top, "meth"); |
294 | } else { |
295 | process($top, "subused"); |
296 | } |
297 | $top = UNKNOWN; |
298 | } |
299 | |
300 | # |
301 | # Stuff for cross referencing definitions of variables and subs |
302 | # |
303 | |
304 | sub B::GV::xref { |
305 | my $gv = shift; |
306 | my $cv = $gv->CV; |
307 | if ($$cv) { |
308 | #return if $done{$$cv}++; |
b195d487 |
309 | $file = $gv->FILE; |
a798dbf2 |
310 | $line = $gv->LINE; |
311 | process([$gv->STASH->NAME, "&", $gv->NAME], "subdef"); |
312 | push(@todo, $cv); |
313 | } |
314 | my $form = $gv->FORM; |
315 | if ($$form) { |
316 | return if $done{$$form}++; |
b195d487 |
317 | $file = $gv->FILE; |
a798dbf2 |
318 | $line = $gv->LINE; |
319 | process([$gv->STASH->NAME, "", $gv->NAME], "formdef"); |
320 | } |
321 | } |
322 | |
323 | sub xref_definitions { |
324 | my ($pack, %exclude); |
325 | return if $nodefs; |
326 | $subname = "(definitions)"; |
595f3c5f |
327 | foreach $pack (qw(B O AutoLoader DynaLoader XSLoader Config DB VMS |
a798dbf2 |
328 | strict vars FileHandle Exporter Carp)) { |
329 | $exclude{$pack."::"} = 1; |
330 | } |
331 | no strict qw(vars refs); |
332 | walksymtable(\%{"main::"}, "xref", sub { !defined($exclude{$_[0]}) }); |
333 | } |
334 | |
335 | sub output { |
336 | return if $raw; |
337 | my ($file, $subname, $pack, $name, $ev, $perfile, $persubname, |
338 | $perpack, $pername, $perev); |
339 | foreach $file (sort(keys(%table))) { |
340 | $perfile = $table{$file}; |
341 | print "File $file\n"; |
342 | foreach $subname (sort(keys(%$perfile))) { |
343 | $persubname = $perfile->{$subname}; |
344 | print " Subroutine $subname\n"; |
345 | foreach $pack (sort(keys(%$persubname))) { |
346 | $perpack = $persubname->{$pack}; |
347 | print " Package $pack\n"; |
348 | foreach $name (sort(keys(%$perpack))) { |
349 | $pername = $perpack->{$name}; |
350 | my @lines; |
351 | foreach $ev (qw(intro formdef subdef meth subused used)) { |
352 | $perev = $pername->{$ev}; |
353 | if (defined($perev) && @$perev) { |
354 | my $code = $code{$ev}; |
355 | push(@lines, map("$code$_", @$perev)); |
356 | } |
357 | } |
358 | printf " %-16s %s\n", $name, join(", ", @lines); |
359 | } |
360 | } |
361 | } |
362 | } |
363 | } |
364 | |
365 | sub compile { |
366 | my @options = @_; |
367 | my ($option, $opt, $arg); |
368 | OPTION: |
369 | while ($option = shift @options) { |
370 | if ($option =~ /^-(.)(.*)/) { |
371 | $opt = $1; |
372 | $arg = $2; |
373 | } else { |
374 | unshift @options, $option; |
375 | last OPTION; |
376 | } |
377 | if ($opt eq "-" && $arg eq "-") { |
378 | shift @options; |
379 | last OPTION; |
380 | } elsif ($opt eq "o") { |
381 | $arg ||= shift @options; |
382 | open(STDOUT, ">$arg") or return "$arg: $!\n"; |
383 | } elsif ($opt eq "d") { |
384 | $nodefs = 1; |
385 | } elsif ($opt eq "r") { |
386 | $raw = 1; |
387 | } elsif ($opt eq "D") { |
388 | $arg ||= shift @options; |
389 | foreach $arg (split(//, $arg)) { |
390 | if ($arg eq "o") { |
391 | B->debug(1); |
392 | } elsif ($arg eq "O") { |
393 | $debug_op = 1; |
394 | } elsif ($arg eq "t") { |
395 | $debug_top = 1; |
396 | } |
397 | } |
398 | } |
399 | } |
400 | if (@options) { |
401 | return sub { |
402 | my $objname; |
403 | xref_definitions(); |
404 | foreach $objname (@options) { |
405 | $objname = "main::$objname" unless $objname =~ /::/; |
406 | eval "xref_object(\\&$objname)"; |
407 | die "xref_object(\\&$objname) failed: $@" if $@; |
408 | } |
409 | output(); |
410 | } |
411 | } else { |
412 | return sub { |
413 | xref_definitions(); |
414 | xref_main(); |
415 | output(); |
416 | } |
417 | } |
418 | } |
419 | |
420 | 1; |