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