Commit | Line | Data |
4633a7c4 |
1 | #!/usr/local/bin/perl |
2 | eval 'exec perl -S $0 ${1+"$@"}' |
37120919 |
3 | if 0; |
4633a7c4 |
4 | |
5 | use Config; |
c6538b72 |
6 | if ($^O eq 'VMS') { |
1446e948 |
7 | $diagnostics::PODFILE = VMS::Filespec::unixify($Config{'privlibexp'}) . |
c07a80fd |
8 | '/pod/perldiag.pod'; |
9 | } |
1446e948 |
10 | else { $diagnostics::PODFILE= $Config{privlibexp} . "/pod/perldiag.pod"; } |
4633a7c4 |
11 | |
12 | package diagnostics; |
13 | require 5.001; |
14 | use English; |
15 | use Carp; |
16 | |
17 | =head1 NAME |
18 | |
19 | diagnostics - Perl compiler pragma to force verbose warning diagnostics |
20 | |
21 | splain - standalone program to do the same thing |
22 | |
23 | =head1 SYNOPSIS |
24 | |
25 | As a pragma: |
26 | |
27 | use diagnostics; |
28 | use diagnostics -verbose; |
29 | |
30 | enable diagnostics; |
31 | disable diagnostics; |
32 | |
33 | Aa a program: |
34 | |
35 | perl program 2>diag.out |
36 | splain [-v] [-p] diag.out |
37 | |
38 | |
39 | =head1 DESCRIPTION |
40 | |
41 | =head2 The C<diagnostics> Pragma |
42 | |
43 | This module extends the terse diagnostics normally emitted by both the |
1fef88e7 |
44 | perl compiler and the perl interpeter, augmenting them with the more |
4633a7c4 |
45 | explicative and endearing descriptions found in L<perldiag>. Like the |
1fef88e7 |
46 | other pragmata, it affects the compilation phase of your program rather |
4633a7c4 |
47 | than merely the execution phase. |
48 | |
49 | To use in your program as a pragma, merely invoke |
50 | |
51 | use diagnostics; |
52 | |
53 | at the start (or near the start) of your program. (Note |
54 | that this I<does> enable perl's B<-w> flag.) Your whole |
55 | compilation will then be subject(ed :-) to the enhanced diagnostics. |
56 | These still go out B<STDERR>. |
57 | |
58 | Due to the interaction between runtime and compiletime issues, |
59 | and because it's probably not a very good idea anyway, |
60 | you may not use C<no diagnostics> to turn them off at compiletime. |
61 | However, you may control there behaviour at runtime using the |
62 | disable() and enable() methods to turn them off and on respectively. |
63 | |
64 | The B<-verbose> flag first prints out the L<perldiag> introduction before |
1fef88e7 |
65 | any other diagnostics. The $diagnostics::PRETTY variable can generate nicer |
66 | escape sequences for pagers. |
4633a7c4 |
67 | |
68 | =head2 The I<splain> Program |
69 | |
70 | While apparently a whole nuther program, I<splain> is actually nothing |
71 | more than a link to the (executable) F<diagnostics.pm> module, as well as |
72 | a link to the F<diagnostics.pod> documentation. The B<-v> flag is like |
73 | the C<use diagnostics -verbose> directive. |
74 | The B<-p> flag is like the |
75 | $diagnostics::PRETTY variable. Since you're post-processing with |
76 | I<splain>, there's no sense in being able to enable() or disable() processing. |
77 | |
78 | Output from I<splain> is directed to B<STDOUT>, unlike the pragma. |
79 | |
80 | =head1 EXAMPLES |
81 | |
82 | The following file is certain to trigger a few errors at both |
83 | runtime and compiletime: |
84 | |
85 | use diagnostics; |
86 | print NOWHERE "nothing\n"; |
87 | print STDERR "\n\tThis message should be unadorned.\n"; |
88 | warn "\tThis is a user warning"; |
89 | print "\nDIAGNOSTIC TESTER: Please enter a <CR> here: "; |
90 | my $a, $b = scalar <STDIN>; |
91 | print "\n"; |
92 | print $x/$y; |
93 | |
94 | If you prefer to run your program first and look at its problem |
95 | afterwards, do this: |
96 | |
97 | perl -w test.pl 2>test.out |
98 | ./splain < test.out |
99 | |
100 | Note that this is not in general possible in shells of more dubious heritage, |
1fef88e7 |
101 | as the theoretical |
4633a7c4 |
102 | |
103 | (perl -w test.pl >/dev/tty) >& test.out |
104 | ./splain < test.out |
105 | |
106 | Because you just moved the existing B<stdout> to somewhere else. |
107 | |
108 | If you don't want to modify your source code, but still have on-the-fly |
109 | warnings, do this: |
110 | |
111 | exec 3>&1; perl -w test.pl 2>&1 1>&3 3>&- | splain 1>&2 3>&- |
112 | |
113 | Nifty, eh? |
114 | |
115 | If you want to control warnings on the fly, do something like this. |
116 | Make sure you do the C<use> first, or you won't be able to get |
117 | at the enable() or disable() methods. |
118 | |
119 | use diagnostics; # checks entire compilation phase |
120 | print "\ntime for 1st bogus diags: SQUAWKINGS\n"; |
121 | print BOGUS1 'nada'; |
122 | print "done with 1st bogus\n"; |
123 | |
124 | disable diagnostics; # only turns off runtime warnings |
125 | print "\ntime for 2nd bogus: (squelched)\n"; |
126 | print BOGUS2 'nada'; |
127 | print "done with 2nd bogus\n"; |
128 | |
129 | enable diagnostics; # turns back on runtime warnings |
130 | print "\ntime for 3rd bogus: SQUAWKINGS\n"; |
131 | print BOGUS3 'nada'; |
132 | print "done with 3rd bogus\n"; |
133 | |
134 | disable diagnostics; |
135 | print "\ntime for 4th bogus: (squelched)\n"; |
136 | print BOGUS4 'nada'; |
137 | print "done with 4th bogus\n"; |
138 | |
139 | =head1 INTERNALS |
140 | |
141 | Diagnostic messages derive from the F<perldiag.pod> file when available at |
142 | runtime. Otherwise, they may be embedded in the file itself when the |
143 | splain package is built. See the F<Makefile> for details. |
144 | |
145 | If an extant $SIG{__WARN__} handler is discovered, it will continue |
1fef88e7 |
146 | to be honored, but only after the diagnostics::splainthis() function |
4633a7c4 |
147 | (the module's $SIG{__WARN__} interceptor) has had its way with your |
148 | warnings. |
149 | |
150 | There is a $diagnostics::DEBUG variable you may set if you're desperately |
151 | curious what sorts of things are being intercepted. |
152 | |
153 | BEGIN { $diagnostics::DEBUG = 1 } |
154 | |
155 | |
156 | =head1 BUGS |
157 | |
158 | Not being able to say "no diagnostics" is annoying, but may not be |
159 | insurmountable. |
160 | |
161 | The C<-pretty> directive is called too late to affect matters. |
162 | You have to to this instead, and I<before> you load the module. |
163 | |
164 | BEGIN { $diagnostics::PRETTY = 1 } |
165 | |
166 | I could start up faster by delaying compilation until it should be |
167 | needed, but this gets a "panic: top_level" |
168 | when using the pragma form in 5.001e. |
169 | |
170 | While it's true that this documentation is somewhat subserious, if you use |
171 | a program named I<splain>, you should expect a bit of whimsy. |
172 | |
173 | =head1 AUTHOR |
174 | |
175 | Tom Christiansen F<E<lt>tchrist@mox.perl.comE<gt>>, 25 June 1995. |
176 | |
177 | =cut |
178 | |
179 | $DEBUG ||= 0; |
180 | my $WHOAMI = ref bless []; # nobody's business, prolly not even mine |
181 | |
182 | $OUTPUT_AUTOFLUSH = 1; |
183 | |
184 | local $_; |
185 | |
186 | CONFIG: { |
187 | $opt_p = $opt_d = $opt_v = $opt_f = ''; |
188 | %HTML_2_Troff = %HTML_2_Latin_1 = %HTML_2_ASCII_7 = (); |
189 | %exact_duplicate = (); |
190 | |
191 | unless (caller) { |
192 | $standalone++; |
193 | require Getopt::Std; |
194 | Getopt::Std::getopts('pdvf:') || die "Usage: $0 [-v] [-p] [-f splainpod]"; |
195 | $PODFILE = $opt_f if $opt_f; |
196 | $DEBUG = 2 if $opt_d; |
197 | $VERBOSE = $opt_v; |
198 | $PRETTY = $opt_p; |
199 | } |
200 | |
201 | if (open(POD_DIAG, $PODFILE)) { |
202 | warn "Happy happy podfile from real $PODFILE\n" if $DEBUG; |
203 | last CONFIG; |
204 | } |
205 | |
206 | if (caller) { |
207 | INCPATH: { |
208 | for $file ( (map { "$_/$WHOAMI.pm" } @INC), $0) { |
209 | warn "Checking $file\n" if $DEBUG; |
210 | if (open(POD_DIAG, $file)) { |
211 | while (<POD_DIAG>) { |
212 | next unless /^__END__\s*# wish diag dbase were more accessible/; |
213 | print STDERR "podfile is $file\n" if $DEBUG; |
214 | last INCPATH; |
215 | } |
216 | } |
217 | } |
218 | } |
219 | } else { |
220 | print STDERR "podfile is <DATA>\n" if $DEBUG; |
221 | *POD_DIAG = *main::DATA; |
222 | } |
223 | } |
224 | if (eof(POD_DIAG)) { |
225 | die "couldn't find diagnostic data in $PODFILE @INC $0"; |
226 | } |
227 | |
228 | |
229 | %HTML_2_Troff = ( |
230 | 'amp' => '&', # ampersand |
231 | 'lt' => '<', # left chevron, less-than |
232 | 'gt' => '>', # right chevron, greater-than |
233 | 'quot' => '"', # double quote |
234 | |
235 | "Aacute" => "A\\*'", # capital A, acute accent |
236 | # etc |
237 | |
238 | ); |
239 | |
240 | %HTML_2_Latin_1 = ( |
241 | 'amp' => '&', # ampersand |
242 | 'lt' => '<', # left chevron, less-than |
243 | 'gt' => '>', # right chevron, greater-than |
244 | 'quot' => '"', # double quote |
245 | |
246 | "Aacute" => "\xC1" # capital A, acute accent |
247 | |
248 | # etc |
249 | ); |
250 | |
251 | %HTML_2_ASCII_7 = ( |
252 | 'amp' => '&', # ampersand |
253 | 'lt' => '<', # left chevron, less-than |
254 | 'gt' => '>', # right chevron, greater-than |
255 | 'quot' => '"', # double quote |
256 | |
257 | "Aacute" => "A" # capital A, acute accent |
258 | # etc |
259 | ); |
260 | |
261 | *HTML_Escapes = do { |
262 | if ($standalone) { |
263 | $PRETTY ? \%HTML_2_Latin_1 : \%HTML_2_ASCII_7; |
264 | } else { |
265 | \%HTML_2_Latin_1; |
266 | } |
267 | }; |
268 | |
269 | *THITHER = $standalone ? *STDOUT : *STDERR; |
270 | |
271 | $transmo = <<EOFUNC; |
272 | sub transmo { |
273 | local \$^W = 0; # recursive warnings we do NOT need! |
274 | study; |
275 | EOFUNC |
276 | |
277 | ### sub finish_compilation { # 5.001e panic: top_level for embedded version |
278 | print STDERR "FINISHING COMPILATION for $_\n" if $DEBUG; |
279 | ### local |
280 | $RS = ''; |
281 | local $_; |
282 | while (<POD_DIAG>) { |
283 | #s/(.*)\n//; |
284 | #$header = $1; |
285 | |
286 | unescape(); |
287 | if ($PRETTY) { |
288 | sub noop { return $_[0] } # spensive for a noop |
289 | sub bold { my $str =$_[0]; $str =~ s/(.)/$1\b$1/g; return $str; } |
290 | sub italic { my $str = $_[0]; $str =~ s/(.)/_\b$1/g; return $str; } |
291 | s/[BC]<(.*?)>/bold($1)/ges; |
292 | s/[LIF]<(.*?)>/italic($1)/ges; |
293 | } else { |
294 | s/[BC]<(.*?)>/$1/gs; |
295 | s/[LIF]<(.*?)>/$1/gs; |
296 | } |
297 | unless (/^=/) { |
298 | if (defined $header) { |
299 | if ( $header eq 'DESCRIPTION' && |
300 | ( /Optional warnings are enabled/ |
301 | || /Some of these messages are generic./ |
302 | ) ) |
303 | { |
304 | next; |
305 | } |
306 | s/^/ /gm; |
307 | $msg{$header} .= $_; |
308 | } |
309 | next; |
310 | } |
311 | unless ( s/=item (.*)\s*\Z//) { |
312 | |
313 | if ( s/=head1\sDESCRIPTION//) { |
314 | $msg{$header = 'DESCRIPTION'} = ''; |
315 | } |
316 | next; |
317 | } |
318 | $header = $1; |
319 | |
320 | if ($header =~ /%[sd]/) { |
321 | $rhs = $lhs = $header; |
322 | #if ($lhs =~ s/(.*?)%d(?!%d)(.*)/\Q$1\E\\d+\Q$2\E\$/g) { |
323 | if ($lhs =~ s/(.*?)%d(?!%d)(.*)/\Q$1\E\\d+\Q$2\E/g) { |
324 | $lhs =~ s/\\%s/.*?/g; |
325 | } else { |
326 | # if i had lookbehind negations, i wouldn't have to do this \377 noise |
327 | $lhs =~ s/(.*?)%s/\Q$1\E.*?\377/g; |
328 | #$lhs =~ s/\377([^\377]*)$/\Q$1\E\$/; |
329 | $lhs =~ s/\377([^\377]*)$/\Q$1\E/; |
330 | $lhs =~ s/\377//g; |
331 | } |
332 | $transmo .= " s{^$lhs}\n {\Q$rhs\E}\n\t&& return 1;\n"; |
333 | } else { |
334 | $transmo .= " m{^\Q$header\E} && return 1;\n"; |
335 | } |
336 | |
337 | print STDERR "Already saw $header" if $msg{$header}; |
338 | |
339 | $msg{$header} = ''; |
340 | } |
341 | |
342 | |
343 | close POD_DIAG unless *main::DATA eq *POD_DIAG; |
344 | |
345 | die "No diagnostics?" unless %msg; |
346 | |
347 | $transmo .= " return 0;\n}\n"; |
348 | print STDERR $transmo if $DEBUG; |
349 | eval $transmo; |
350 | die $@ if $@; |
351 | $RS = "\n"; |
352 | ### } |
353 | |
354 | if ($standalone) { |
355 | if (!@ARGV and -t STDIN) { print STDERR "$0: Reading from STDIN\n" } |
356 | while ($error = <>) { |
357 | splainthis($error) || print THITHER $error; |
358 | } |
359 | exit; |
360 | } else { |
361 | $old_w = 0; $oldwarn = ''; $olddie = ''; |
362 | } |
363 | |
364 | sub import { |
365 | shift; |
366 | $old_w = $^W; |
367 | $^W = 1; # yup, clobbered the global variable; tough, if you |
368 | # want diags, you want diags. |
369 | return if $SIG{__WARN__} eq \&warn_trap; |
370 | |
371 | for (@_) { |
372 | |
373 | /^-d(ebug)?$/ && do { |
374 | $DEBUG++; |
375 | next; |
376 | }; |
377 | |
378 | /^-v(erbose)?$/ && do { |
379 | $VERBOSE++; |
380 | next; |
381 | }; |
382 | |
383 | /^-p(retty)?$/ && do { |
384 | print STDERR "$0: I'm afraid it's too late for prettiness.\n"; |
385 | $PRETTY++; |
386 | next; |
387 | }; |
388 | |
389 | warn "Unknown flag: $_"; |
390 | } |
391 | |
392 | $oldwarn = $SIG{__WARN__}; |
393 | $olddie = $SIG{__DIE__}; |
394 | $SIG{__WARN__} = \&warn_trap; |
395 | $SIG{__DIE__} = \&death_trap; |
396 | } |
397 | |
398 | sub enable { &import } |
399 | |
400 | sub disable { |
401 | shift; |
402 | $^W = $old_w; |
403 | return unless $SIG{__WARN__} eq \&warn_trap; |
404 | $SIG{__WARN__} = $oldwarn; |
405 | $SIG{__DIE__} = $olddie; |
406 | } |
407 | |
408 | sub warn_trap { |
409 | my $warning = $_[0]; |
410 | if (caller eq $WHOAMI or !splainthis($warning)) { |
411 | print STDERR $warning; |
412 | } |
37120919 |
413 | &$oldwarn if defined $oldwarn and $oldwarn and $oldwarn ne \&warn_trap; |
4633a7c4 |
414 | }; |
415 | |
416 | sub death_trap { |
417 | my $exception = $_[0]; |
418 | splainthis($exception); |
419 | if (caller eq $WHOAMI) { print STDERR "INTERNAL EXCEPTION: $exception"; } |
37120919 |
420 | &$olddie if defined $olddie and $olddie and $olddie ne \&death_trap; |
4633a7c4 |
421 | $SIG{__DIE__} = $SIG{__WARN__} = ''; |
6f48387a |
422 | local($Carp::CarpLevel) = 1; |
423 | confess "Uncaught exception from user code:\n\t$exception"; |
4633a7c4 |
424 | # up we go; where we stop, nobody knows, but i think we die now |
425 | # but i'm deeply afraid of the &$olddie guy reraising and us getting |
426 | # into an indirect recursion loop |
427 | }; |
428 | |
429 | sub splainthis { |
430 | local $_ = shift; |
431 | ### &finish_compilation unless %msg; |
432 | s/\.?\n+$//; |
433 | my $orig = $_; |
434 | # return unless defined; |
435 | if ($exact_duplicate{$_}++) { |
436 | return 1; |
437 | } |
438 | s/, <.*?> (?:line|chunk).*$//; |
439 | $real = s/(.*?) at .*? (?:line|chunk) \d+.*/$1/; |
440 | s/^\((.*)\)$/$1/; |
441 | return 0 unless &transmo; |
442 | $orig = shorten($orig); |
443 | if ($old_diag{$_}) { |
444 | autodescribe(); |
445 | print THITHER "$orig (#$old_diag{$_})\n"; |
446 | $wantspace = 1; |
447 | } else { |
448 | autodescribe(); |
449 | $old_diag{$_} = ++$count; |
450 | print THITHER "\n" if $wantspace; |
451 | $wantspace = 0; |
452 | print THITHER "$orig (#$old_diag{$_})\n"; |
453 | if ($msg{$_}) { |
454 | print THITHER $msg{$_}; |
455 | } else { |
456 | if (0 and $standalone) { |
457 | print THITHER " **** Error #$old_diag{$_} ", |
458 | ($real ? "is" : "appears to be"), |
459 | " an unknown diagnostic message.\n\n"; |
460 | } |
461 | return 0; |
462 | } |
463 | } |
464 | return 1; |
465 | } |
466 | |
467 | sub autodescribe { |
468 | if ($VERBOSE and not $count) { |
469 | print THITHER &{$PRETTY ? \&bold : \&noop}("DESCRIPTION OF DIAGNOSTICS"), |
470 | "\n$msg{DESCRIPTION}\n"; |
471 | } |
472 | } |
473 | |
474 | sub unescape { |
475 | s { |
476 | E< |
477 | ( [A-Za-z]+ ) |
478 | > |
479 | } { |
480 | do { |
481 | exists $HTML_Escapes{$1} |
482 | ? do { $HTML_Escapes{$1} } |
483 | : do { |
484 | warn "Unknown escape: $& in $_"; |
485 | "E<$1>"; |
486 | } |
487 | } |
488 | }egx; |
489 | } |
490 | |
491 | sub shorten { |
492 | my $line = $_[0]; |
493 | if (length $line > 79) { |
494 | my $space_place = rindex($line, ' ', 79); |
495 | if ($space_place != -1) { |
496 | substr($line, $space_place, 1) = "\n\t"; |
497 | } |
498 | } |
499 | return $line; |
500 | } |
501 | |
502 | |
503 | # have to do this: RS isn't set until run time, but we're executing at compile time |
504 | $RS = "\n"; |
505 | |
506 | 1 unless $standalone; # or it'll complain about itself |
507 | __END__ # wish diag dbase were more accessible |