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1 | package B::Xref; |
2 | ||
28b605d8 JH |
3 | our $VERSION = '1.00'; |
4 | ||
a798dbf2 MB |
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 | |
24 | object1 C<line numbers> | |
25 | object2 C<line numbers> | |
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 | ||
67 | =item C<-D[tO]> | |
68 | ||
69 | (Internal) debug options, probably only useful if C<-r> included. | |
70 | The C<t> option prints the object on the top of the stack as it's | |
71 | being tracked. The C<O> option prints each operator as it's being | |
72 | processed in the execution order of the program. | |
73 | ||
74 | =back | |
75 | ||
76 | =head1 BUGS | |
77 | ||
78 | Non-lexical variables are quite difficult to track through a program. | |
79 | Sometimes the type of a non-lexical variable's use is impossible to | |
80 | determine. Introductions of non-lexical non-scalars don't seem to be | |
81 | reported properly. | |
82 | ||
83 | =head1 AUTHOR | |
84 | ||
85 | Malcolm Beattie, mbeattie@sable.ox.ac.uk. | |
86 | ||
87 | =cut | |
88 | ||
89 | use strict; | |
18228111 | 90 | use Config; |
4c1f658f NIS |
91 | use B qw(peekop class comppadlist main_start svref_2object walksymtable |
92 | OPpLVAL_INTRO SVf_POK | |
93 | ); | |
a798dbf2 MB |
94 | |
95 | sub UNKNOWN { ["?", "?", "?"] } | |
96 | ||
97 | my @pad; # lexicals in current pad | |
98 | # as ["(lexical)", type, name] | |
99 | my %done; # keyed by $$op: set when each $op is done | |
100 | my $top = UNKNOWN; # shadows top element of stack as | |
101 | # [pack, type, name] (pack can be "(lexical)") | |
102 | my $file; # shadows current filename | |
103 | my $line; # shadows current line number | |
104 | my $subname; # shadows current sub name | |
105 | my %table; # Multi-level hash to record all uses etc. | |
106 | my @todo = (); # List of CVs that need processing | |
107 | ||
108 | my %code = (intro => "i", used => "", | |
109 | subdef => "s", subused => "&", | |
110 | formdef => "f", meth => "->"); | |
111 | ||
112 | ||
113 | # Options | |
114 | my ($debug_op, $debug_top, $nodefs, $raw); | |
115 | ||
116 | sub process { | |
117 | my ($var, $event) = @_; | |
118 | my ($pack, $type, $name) = @$var; | |
119 | if ($type eq "*") { | |
120 | if ($event eq "used") { | |
121 | return; | |
122 | } elsif ($event eq "subused") { | |
123 | $type = "&"; | |
124 | } | |
125 | } | |
126 | $type =~ s/(.)\*$/$1/g; | |
127 | if ($raw) { | |
128 | printf "%-16s %-12s %5d %-12s %4s %-16s %s\n", | |
129 | $file, $subname, $line, $pack, $type, $name, $event; | |
130 | } else { | |
131 | # Wheee | |
132 | push(@{$table{$file}->{$subname}->{$pack}->{$type.$name}->{$event}}, | |
133 | $line); | |
134 | } | |
135 | } | |
136 | ||
137 | sub load_pad { | |
138 | my $padlist = shift; | |
18228111 | 139 | my ($namelistav, $vallistav, @namelist, $ix); |
a798dbf2 MB |
140 | @pad = (); |
141 | return if class($padlist) eq "SPECIAL"; | |
18228111 | 142 | ($namelistav,$vallistav) = $padlist->ARRAY; |
a798dbf2 MB |
143 | @namelist = $namelistav->ARRAY; |
144 | for ($ix = 1; $ix < @namelist; $ix++) { | |
145 | my $namesv = $namelist[$ix]; | |
146 | next if class($namesv) eq "SPECIAL"; | |
51e5a3db | 147 | my ($type, $name) = $namesv->PV =~ /^(.)([^\0]*)(\0.*)?$/; |
a798dbf2 MB |
148 | $pad[$ix] = ["(lexical)", $type, $name]; |
149 | } | |
18228111 GS |
150 | if ($Config{useithreads}) { |
151 | my (@vallist); | |
152 | @vallist = $vallistav->ARRAY; | |
153 | for ($ix = 1; $ix < @vallist; $ix++) { | |
154 | my $valsv = $vallist[$ix]; | |
155 | next unless class($valsv) eq "GV"; | |
156 | # these pad GVs don't have corresponding names, so same @pad | |
157 | # array can be used without collisions | |
158 | $pad[$ix] = [$valsv->STASH->NAME, "*", $valsv->NAME]; | |
159 | } | |
160 | } | |
a798dbf2 MB |
161 | } |
162 | ||
163 | sub xref { | |
164 | my $start = shift; | |
165 | my $op; | |
166 | for ($op = $start; $$op; $op = $op->next) { | |
167 | last if $done{$$op}++; | |
168 | warn sprintf("top = [%s, %s, %s]\n", @$top) if $debug_top; | |
169 | warn peekop($op), "\n" if $debug_op; | |
3f872cb9 GS |
170 | my $opname = $op->name; |
171 | if ($opname =~ /^(or|and|mapwhile|grepwhile|range|cond_expr)$/) { | |
a798dbf2 | 172 | xref($op->other); |
3f872cb9 | 173 | } elsif ($opname eq "match" || $opname eq "subst") { |
a798dbf2 | 174 | xref($op->pmreplstart); |
3f872cb9 | 175 | } elsif ($opname eq "substcont") { |
a798dbf2 MB |
176 | xref($op->other->pmreplstart); |
177 | $op = $op->other; | |
178 | redo; | |
3f872cb9 | 179 | } elsif ($opname eq "enterloop") { |
a798dbf2 MB |
180 | xref($op->redoop); |
181 | xref($op->nextop); | |
182 | xref($op->lastop); | |
3f872cb9 | 183 | } elsif ($opname eq "subst") { |
a798dbf2 MB |
184 | xref($op->pmreplstart); |
185 | } else { | |
186 | no strict 'refs'; | |
3f872cb9 | 187 | my $ppname = "pp_$opname"; |
a798dbf2 MB |
188 | &$ppname($op) if defined(&$ppname); |
189 | } | |
190 | } | |
191 | } | |
192 | ||
193 | sub xref_cv { | |
194 | my $cv = shift; | |
195 | my $pack = $cv->GV->STASH->NAME; | |
196 | $subname = ($pack eq "main" ? "" : "$pack\::") . $cv->GV->NAME; | |
197 | load_pad($cv->PADLIST); | |
198 | xref($cv->START); | |
199 | $subname = "(main)"; | |
200 | } | |
201 | ||
202 | sub xref_object { | |
203 | my $cvref = shift; | |
204 | xref_cv(svref_2object($cvref)); | |
205 | } | |
206 | ||
207 | sub xref_main { | |
208 | $subname = "(main)"; | |
209 | load_pad(comppadlist); | |
210 | xref(main_start); | |
211 | while (@todo) { | |
212 | xref_cv(shift @todo); | |
213 | } | |
214 | } | |
215 | ||
216 | sub pp_nextstate { | |
217 | my $op = shift; | |
57843af0 | 218 | $file = $op->file; |
a798dbf2 MB |
219 | $line = $op->line; |
220 | $top = UNKNOWN; | |
221 | } | |
222 | ||
223 | sub pp_padsv { | |
224 | my $op = shift; | |
225 | $top = $pad[$op->targ]; | |
226 | process($top, $op->private & OPpLVAL_INTRO ? "intro" : "used"); | |
227 | } | |
228 | ||
229 | sub pp_padav { pp_padsv(@_) } | |
230 | sub pp_padhv { pp_padsv(@_) } | |
231 | ||
232 | sub deref { | |
233 | my ($var, $as) = @_; | |
234 | $var->[1] = $as . $var->[1]; | |
235 | process($var, "used"); | |
236 | } | |
237 | ||
238 | sub pp_rv2cv { deref($top, "&"); } | |
239 | sub pp_rv2hv { deref($top, "%"); } | |
240 | sub pp_rv2sv { deref($top, "\$"); } | |
241 | sub pp_rv2av { deref($top, "\@"); } | |
242 | sub pp_rv2gv { deref($top, "*"); } | |
243 | ||
244 | sub pp_gvsv { | |
245 | my $op = shift; | |
18228111 GS |
246 | my $gv; |
247 | if ($Config{useithreads}) { | |
248 | $top = $pad[$op->padix]; | |
249 | $top = UNKNOWN unless $top; | |
250 | $top->[1] = '$'; | |
251 | } | |
252 | else { | |
253 | $gv = $op->gv; | |
254 | $top = [$gv->STASH->NAME, '$', $gv->NAME]; | |
255 | } | |
a798dbf2 MB |
256 | process($top, $op->private & OPpLVAL_INTRO ? "intro" : "used"); |
257 | } | |
258 | ||
259 | sub pp_gv { | |
260 | my $op = shift; | |
18228111 GS |
261 | my $gv; |
262 | if ($Config{useithreads}) { | |
263 | $top = $pad[$op->padix]; | |
264 | $top = UNKNOWN unless $top; | |
265 | $top->[1] = '*'; | |
266 | } | |
267 | else { | |
268 | $gv = $op->gv; | |
269 | $top = [$gv->STASH->NAME, "*", $gv->NAME]; | |
270 | } | |
a798dbf2 MB |
271 | process($top, $op->private & OPpLVAL_INTRO ? "intro" : "used"); |
272 | } | |
273 | ||
274 | sub pp_const { | |
275 | my $op = shift; | |
276 | my $sv = $op->sv; | |
18228111 GS |
277 | # constant could be in the pad (under useithreads) |
278 | if ($$sv) { | |
279 | $top = ["?", "", | |
280 | (class($sv) ne "SPECIAL" && $sv->FLAGS & SVf_POK) ? $sv->PV : "?"]; | |
281 | } | |
282 | else { | |
283 | $top = $pad[$op->targ]; | |
284 | } | |
a798dbf2 MB |
285 | } |
286 | ||
287 | sub pp_method { | |
288 | my $op = shift; | |
289 | $top = ["(method)", "->".$top->[1], $top->[2]]; | |
290 | } | |
291 | ||
292 | sub pp_entersub { | |
293 | my $op = shift; | |
294 | if ($top->[1] eq "m") { | |
295 | process($top, "meth"); | |
296 | } else { | |
297 | process($top, "subused"); | |
298 | } | |
299 | $top = UNKNOWN; | |
300 | } | |
301 | ||
302 | # | |
303 | # Stuff for cross referencing definitions of variables and subs | |
304 | # | |
305 | ||
306 | sub B::GV::xref { | |
307 | my $gv = shift; | |
308 | my $cv = $gv->CV; | |
309 | if ($$cv) { | |
310 | #return if $done{$$cv}++; | |
b195d487 | 311 | $file = $gv->FILE; |
a798dbf2 MB |
312 | $line = $gv->LINE; |
313 | process([$gv->STASH->NAME, "&", $gv->NAME], "subdef"); | |
314 | push(@todo, $cv); | |
315 | } | |
316 | my $form = $gv->FORM; | |
317 | if ($$form) { | |
318 | return if $done{$$form}++; | |
b195d487 | 319 | $file = $gv->FILE; |
a798dbf2 MB |
320 | $line = $gv->LINE; |
321 | process([$gv->STASH->NAME, "", $gv->NAME], "formdef"); | |
322 | } | |
323 | } | |
324 | ||
325 | sub xref_definitions { | |
326 | my ($pack, %exclude); | |
327 | return if $nodefs; | |
328 | $subname = "(definitions)"; | |
595f3c5f | 329 | foreach $pack (qw(B O AutoLoader DynaLoader XSLoader Config DB VMS |
a798dbf2 MB |
330 | strict vars FileHandle Exporter Carp)) { |
331 | $exclude{$pack."::"} = 1; | |
332 | } | |
333 | no strict qw(vars refs); | |
334 | walksymtable(\%{"main::"}, "xref", sub { !defined($exclude{$_[0]}) }); | |
335 | } | |
336 | ||
337 | sub output { | |
338 | return if $raw; | |
339 | my ($file, $subname, $pack, $name, $ev, $perfile, $persubname, | |
340 | $perpack, $pername, $perev); | |
341 | foreach $file (sort(keys(%table))) { | |
342 | $perfile = $table{$file}; | |
343 | print "File $file\n"; | |
344 | foreach $subname (sort(keys(%$perfile))) { | |
345 | $persubname = $perfile->{$subname}; | |
346 | print " Subroutine $subname\n"; | |
347 | foreach $pack (sort(keys(%$persubname))) { | |
348 | $perpack = $persubname->{$pack}; | |
349 | print " Package $pack\n"; | |
350 | foreach $name (sort(keys(%$perpack))) { | |
351 | $pername = $perpack->{$name}; | |
352 | my @lines; | |
353 | foreach $ev (qw(intro formdef subdef meth subused used)) { | |
354 | $perev = $pername->{$ev}; | |
355 | if (defined($perev) && @$perev) { | |
356 | my $code = $code{$ev}; | |
357 | push(@lines, map("$code$_", @$perev)); | |
358 | } | |
359 | } | |
360 | printf " %-16s %s\n", $name, join(", ", @lines); | |
361 | } | |
362 | } | |
363 | } | |
364 | } | |
365 | } | |
366 | ||
367 | sub compile { | |
368 | my @options = @_; | |
369 | my ($option, $opt, $arg); | |
370 | OPTION: | |
371 | while ($option = shift @options) { | |
372 | if ($option =~ /^-(.)(.*)/) { | |
373 | $opt = $1; | |
374 | $arg = $2; | |
375 | } else { | |
376 | unshift @options, $option; | |
377 | last OPTION; | |
378 | } | |
379 | if ($opt eq "-" && $arg eq "-") { | |
380 | shift @options; | |
381 | last OPTION; | |
382 | } elsif ($opt eq "o") { | |
383 | $arg ||= shift @options; | |
384 | open(STDOUT, ">$arg") or return "$arg: $!\n"; | |
385 | } elsif ($opt eq "d") { | |
386 | $nodefs = 1; | |
387 | } elsif ($opt eq "r") { | |
388 | $raw = 1; | |
389 | } elsif ($opt eq "D") { | |
390 | $arg ||= shift @options; | |
391 | foreach $arg (split(//, $arg)) { | |
392 | if ($arg eq "o") { | |
393 | B->debug(1); | |
394 | } elsif ($arg eq "O") { | |
395 | $debug_op = 1; | |
396 | } elsif ($arg eq "t") { | |
397 | $debug_top = 1; | |
398 | } | |
399 | } | |
400 | } | |
401 | } | |
402 | if (@options) { | |
403 | return sub { | |
404 | my $objname; | |
405 | xref_definitions(); | |
406 | foreach $objname (@options) { | |
407 | $objname = "main::$objname" unless $objname =~ /::/; | |
408 | eval "xref_object(\\&$objname)"; | |
409 | die "xref_object(\\&$objname) failed: $@" if $@; | |
410 | } | |
411 | output(); | |
412 | } | |
413 | } else { | |
414 | return sub { | |
415 | xref_definitions(); | |
416 | xref_main(); | |
417 | output(); | |
418 | } | |
419 | } | |
420 | } | |
421 | ||
422 | 1; |