Commit | Line | Data |
---|---|---|
599cee73 | 1 | #!/usr/bin/perl |
c4a853d1 | 2 | # |
6294c161 DM |
3 | # Regenerate (overwriting only if changed): |
4 | # | |
5 | # lib/warnings.pm | |
6 | # warnings.h | |
7 | # | |
8 | # from information hardcoded into this script (the $tree hash), plus the | |
d2ec25a5 | 9 | # template for warnings.pm in the DATA section. |
6294c161 | 10 | # |
91efc02c KW |
11 | # When changing the number of warnings, t/op/caller.t should change to |
12 | # correspond with the value of $BYTES in lib/warnings.pm | |
8457b38f | 13 | # |
6294c161 DM |
14 | # With an argument of 'tree', just dump the contents of $tree and exits. |
15 | # Also accepts the standard regen_lib -q and -v args. | |
16 | # | |
17 | # This script is normally invoked from regen.pl. | |
599cee73 | 18 | |
0febf6c1 | 19 | $VERSION = '1.03'; |
b75c8c73 | 20 | |
73f0cc2d | 21 | BEGIN { |
af001346 | 22 | require 'regen/regen_lib.pl'; |
b6b9a099 | 23 | push @INC, './lib'; |
73f0cc2d | 24 | } |
599cee73 PM |
25 | use strict ; |
26 | ||
27 | sub DEFAULT_ON () { 1 } | |
28 | sub DEFAULT_OFF () { 2 } | |
29 | ||
30 | my $tree = { | |
3c3f8cd6 AB |
31 | 'all' => [ 5.008, { |
32 | 'io' => [ 5.008, { | |
33 | 'pipe' => [ 5.008, DEFAULT_OFF], | |
34 | 'unopened' => [ 5.008, DEFAULT_OFF], | |
35 | 'closed' => [ 5.008, DEFAULT_OFF], | |
36 | 'newline' => [ 5.008, DEFAULT_OFF], | |
37 | 'exec' => [ 5.008, DEFAULT_OFF], | |
38 | 'layer' => [ 5.008, DEFAULT_OFF], | |
39 | 'syscalls' => [ 5.019, DEFAULT_OFF], | |
40 | }], | |
41 | 'syntax' => [ 5.008, { | |
42 | 'ambiguous' => [ 5.008, DEFAULT_OFF], | |
43 | 'semicolon' => [ 5.008, DEFAULT_OFF], | |
44 | 'precedence' => [ 5.008, DEFAULT_OFF], | |
45 | 'bareword' => [ 5.008, DEFAULT_OFF], | |
46 | 'reserved' => [ 5.008, DEFAULT_OFF], | |
47 | 'digit' => [ 5.008, DEFAULT_OFF], | |
48 | 'parenthesis' => [ 5.008, DEFAULT_OFF], | |
49 | 'printf' => [ 5.008, DEFAULT_OFF], | |
50 | 'prototype' => [ 5.008, DEFAULT_OFF], | |
51 | 'qw' => [ 5.008, DEFAULT_OFF], | |
52 | 'illegalproto' => [ 5.011, DEFAULT_OFF], | |
53 | }], | |
54 | 'severe' => [ 5.008, { | |
55 | 'inplace' => [ 5.008, DEFAULT_ON], | |
56 | 'internal' => [ 5.008, DEFAULT_OFF], | |
57 | 'debugging' => [ 5.008, DEFAULT_ON], | |
58 | 'malloc' => [ 5.008, DEFAULT_ON], | |
59 | }], | |
60 | 'deprecated' => [ 5.008, DEFAULT_ON], | |
61 | 'void' => [ 5.008, DEFAULT_OFF], | |
62 | 'recursion' => [ 5.008, DEFAULT_OFF], | |
63 | 'redefine' => [ 5.008, DEFAULT_OFF], | |
64 | 'numeric' => [ 5.008, DEFAULT_OFF], | |
65 | 'uninitialized' => [ 5.008, DEFAULT_OFF], | |
66 | 'once' => [ 5.008, DEFAULT_OFF], | |
67 | 'misc' => [ 5.008, DEFAULT_OFF], | |
68 | 'regexp' => [ 5.008, DEFAULT_OFF], | |
69 | 'glob' => [ 5.008, DEFAULT_ON], | |
70 | 'untie' => [ 5.008, DEFAULT_OFF], | |
71 | 'substr' => [ 5.008, DEFAULT_OFF], | |
72 | 'taint' => [ 5.008, DEFAULT_OFF], | |
73 | 'signal' => [ 5.008, DEFAULT_OFF], | |
74 | 'closure' => [ 5.008, DEFAULT_OFF], | |
75 | 'overflow' => [ 5.008, DEFAULT_OFF], | |
76 | 'portable' => [ 5.008, DEFAULT_OFF], | |
77 | 'utf8' => [ 5.008, { | |
78 | 'surrogate' => [ 5.013, DEFAULT_OFF], | |
79 | 'nonchar' => [ 5.013, DEFAULT_OFF], | |
80 | 'non_unicode' => [ 5.013, DEFAULT_OFF], | |
81 | }], | |
82 | 'exiting' => [ 5.008, DEFAULT_OFF], | |
83 | 'pack' => [ 5.008, DEFAULT_OFF], | |
84 | 'unpack' => [ 5.008, DEFAULT_OFF], | |
85 | 'threads' => [ 5.008, DEFAULT_OFF], | |
86 | 'imprecision' => [ 5.011, DEFAULT_OFF], | |
87 | 'experimental' => [ 5.017, { | |
88 | 'experimental::lexical_subs' => | |
89 | [ 5.017, DEFAULT_ON ], | |
90 | 'experimental::regex_sets' => | |
91 | [ 5.017, DEFAULT_ON ], | |
92 | 'experimental::lexical_topic' => | |
93 | [ 5.017, DEFAULT_ON ], | |
94 | 'experimental::smartmatch' => | |
95 | [ 5.017, DEFAULT_ON ], | |
96 | 'experimental::postderef' => | |
97 | [ 5.019, DEFAULT_ON ], | |
98 | 'experimental::autoderef' => | |
99 | [ 5.019, DEFAULT_ON ], | |
100 | 'experimental::signatures' => | |
101 | [ 5.019, DEFAULT_ON ], | |
102 | 'experimental::win32_perlio' => | |
103 | [ 5.021, DEFAULT_ON ], | |
104 | 'experimental::refaliasing' => | |
105 | [ 5.021, DEFAULT_ON ], | |
106 | 'experimental::re_strict' => | |
107 | [ 5.021, DEFAULT_ON ], | |
108 | 'experimental::const_attr' => | |
109 | [ 5.021, DEFAULT_ON ], | |
9f88e537 FC |
110 | 'experimental::bitwise' => |
111 | [ 5.021, DEFAULT_ON ], | |
3c3f8cd6 AB |
112 | }], |
113 | ||
114 | 'missing' => [ 5.021, DEFAULT_OFF], | |
115 | 'redundant' => [ 5.021, DEFAULT_OFF], | |
116 | 'locale' => [ 5.021, DEFAULT_ON], | |
117 | ||
118 | #'default' => [ 5.008, DEFAULT_ON ], | |
ea5519d6 | 119 | }]}; |
599cee73 | 120 | |
7fc874e8 | 121 | my @def ; |
599cee73 PM |
122 | my %list ; |
123 | my %Value ; | |
0d658bf5 PM |
124 | my %ValueToName ; |
125 | my %NameToValue ; | |
599cee73 | 126 | |
0d658bf5 PM |
127 | my %v_list = () ; |
128 | ||
129 | sub valueWalk | |
130 | { | |
131 | my $tre = shift ; | |
132 | my @list = () ; | |
133 | my ($k, $v) ; | |
134 | ||
135 | foreach $k (sort keys %$tre) { | |
136 | $v = $tre->{$k}; | |
137 | die "duplicate key $k\n" if defined $list{$k} ; | |
138 | die "Value associated with key '$k' is not an ARRAY reference" | |
139 | if !ref $v || ref $v ne 'ARRAY' ; | |
140 | ||
141 | my ($ver, $rest) = @{ $v } ; | |
142 | push @{ $v_list{$ver} }, $k; | |
c4a853d1 | 143 | |
0d658bf5 PM |
144 | if (ref $rest) |
145 | { valueWalk ($rest) } | |
146 | ||
147 | } | |
148 | ||
149 | } | |
150 | ||
151 | sub orderValues | |
152 | { | |
153 | my $index = 0; | |
154 | foreach my $ver ( sort { $a <=> $b } keys %v_list ) { | |
155 | foreach my $name (@{ $v_list{$ver} } ) { | |
156 | $ValueToName{ $index } = [ uc $name, $ver ] ; | |
157 | $NameToValue{ uc $name } = $index ++ ; | |
158 | } | |
159 | } | |
160 | ||
161 | return $index ; | |
162 | } | |
163 | ||
164 | ########################################################################### | |
165 | ||
599cee73 PM |
166 | sub walk |
167 | { | |
168 | my $tre = shift ; | |
169 | my @list = () ; | |
170 | my ($k, $v) ; | |
171 | ||
95dfd3ab GS |
172 | foreach $k (sort keys %$tre) { |
173 | $v = $tre->{$k}; | |
599cee73 | 174 | die "duplicate key $k\n" if defined $list{$k} ; |
0d658bf5 PM |
175 | die "Can't find key '$k'" |
176 | if ! defined $NameToValue{uc $k} ; | |
177 | push @{ $list{$k} }, $NameToValue{uc $k} ; | |
178 | die "Value associated with key '$k' is not an ARRAY reference" | |
179 | if !ref $v || ref $v ne 'ARRAY' ; | |
c4a853d1 | 180 | |
0d658bf5 PM |
181 | my ($ver, $rest) = @{ $v } ; |
182 | if (ref $rest) | |
183 | { push (@{ $list{$k} }, walk ($rest)) } | |
7fc874e8 FC |
184 | elsif ($rest == DEFAULT_ON) |
185 | { push @def, $NameToValue{uc $k} } | |
0d658bf5 | 186 | |
599cee73 PM |
187 | push @list, @{ $list{$k} } ; |
188 | } | |
189 | ||
190 | return @list ; | |
599cee73 PM |
191 | } |
192 | ||
193 | ########################################################################### | |
194 | ||
195 | sub mkRange | |
196 | { | |
197 | my @a = @_ ; | |
198 | my @out = @a ; | |
599cee73 | 199 | |
e95a9fc2 | 200 | for my $i (1 .. @a - 1) { |
0ca4541c | 201 | $out[$i] = ".." |
e95a9fc2 KW |
202 | if $a[$i] == $a[$i - 1] + 1 |
203 | && ($i >= @a - 1 || $a[$i] + 1 == $a[$i + 1] ); | |
599cee73 | 204 | } |
e95a9fc2 | 205 | $out[-1] = $a[-1] if $out[-1] eq ".."; |
599cee73 PM |
206 | |
207 | my $out = join(",",@out); | |
208 | ||
209 | $out =~ s/,(\.\.,)+/../g ; | |
210 | return $out; | |
211 | } | |
212 | ||
213 | ########################################################################### | |
e15f14b8 | 214 | sub warningsTree |
e476b1b5 GS |
215 | { |
216 | my $tre = shift ; | |
217 | my $prefix = shift ; | |
e476b1b5 GS |
218 | my ($k, $v) ; |
219 | ||
220 | my $max = (sort {$a <=> $b} map { length $_ } keys %$tre)[-1] ; | |
0d658bf5 | 221 | my @keys = sort keys %$tre ; |
e476b1b5 | 222 | |
e15f14b8 RS |
223 | my $rv = ''; |
224 | ||
0d658bf5 | 225 | while ($k = shift @keys) { |
e476b1b5 | 226 | $v = $tre->{$k}; |
0d658bf5 PM |
227 | die "Value associated with key '$k' is not an ARRAY reference" |
228 | if !ref $v || ref $v ne 'ARRAY' ; | |
c4a853d1 | 229 | |
0d658bf5 PM |
230 | my $offset ; |
231 | if ($tre ne $tree) { | |
e15f14b8 RS |
232 | $rv .= $prefix . "|\n" ; |
233 | $rv .= $prefix . "+- $k" ; | |
0d658bf5 PM |
234 | $offset = ' ' x ($max + 4) ; |
235 | } | |
236 | else { | |
e15f14b8 | 237 | $rv .= $prefix . "$k" ; |
0d658bf5 PM |
238 | $offset = ' ' x ($max + 1) ; |
239 | } | |
240 | ||
241 | my ($ver, $rest) = @{ $v } ; | |
f1d34ca8 | 242 | if (ref $rest) |
0ca4541c | 243 | { |
0d658bf5 | 244 | my $bar = @keys ? "|" : " "; |
e15f14b8 RS |
245 | $rv .= " -" . "-" x ($max - length $k ) . "+\n" ; |
246 | $rv .= warningsTree ($rest, $prefix . $bar . $offset ) | |
e476b1b5 GS |
247 | } |
248 | else | |
e15f14b8 | 249 | { $rv .= "\n" } |
e476b1b5 GS |
250 | } |
251 | ||
e15f14b8 | 252 | return $rv; |
e476b1b5 GS |
253 | } |
254 | ||
255 | ########################################################################### | |
599cee73 | 256 | |
317ea90d | 257 | sub mkHexOct |
599cee73 | 258 | { |
317ea90d | 259 | my ($f, $max, @a) = @_ ; |
599cee73 PM |
260 | my $mask = "\x00" x $max ; |
261 | my $string = "" ; | |
262 | ||
263 | foreach (@a) { | |
264 | vec($mask, $_, 1) = 1 ; | |
265 | } | |
266 | ||
599cee73 | 267 | foreach (unpack("C*", $mask)) { |
317ea90d MS |
268 | if ($f eq 'x') { |
269 | $string .= '\x' . sprintf("%2.2x", $_) | |
270 | } | |
271 | else { | |
272 | $string .= '\\' . sprintf("%o", $_) | |
273 | } | |
599cee73 PM |
274 | } |
275 | return $string ; | |
276 | } | |
277 | ||
317ea90d MS |
278 | sub mkHex |
279 | { | |
280 | my($max, @a) = @_; | |
281 | return mkHexOct("x", $max, @a); | |
282 | } | |
283 | ||
284 | sub mkOct | |
285 | { | |
286 | my($max, @a) = @_; | |
287 | return mkHexOct("o", $max, @a); | |
288 | } | |
289 | ||
599cee73 PM |
290 | ########################################################################### |
291 | ||
e476b1b5 GS |
292 | if (@ARGV && $ARGV[0] eq "tree") |
293 | { | |
3c3f8cd6 | 294 | print warningsTree($tree, " ") ; |
e476b1b5 GS |
295 | exit ; |
296 | } | |
599cee73 | 297 | |
cc49830d NC |
298 | my ($warn, $pm) = map { |
299 | open_new($_, '>', { by => 'regen/warnings.pl' }); | |
300 | } 'warnings.h', 'lib/warnings.pm'; | |
599cee73 | 301 | |
c4a853d1 RS |
302 | my ($index, $warn_size); |
303 | ||
304 | { | |
305 | # generate warnings.h | |
306 | ||
307 | print $warn <<'EOM'; | |
599cee73 | 308 | |
0453d815 PM |
309 | #define Off(x) ((x) / 8) |
310 | #define Bit(x) (1 << ((x) % 8)) | |
599cee73 PM |
311 | #define IsSet(a, x) ((a)[Off(x)] & Bit(x)) |
312 | ||
0453d815 | 313 | |
599cee73 | 314 | #define G_WARN_OFF 0 /* $^W == 0 */ |
0453d815 | 315 | #define G_WARN_ON 1 /* -w flag and $^W != 0 */ |
599cee73 PM |
316 | #define G_WARN_ALL_ON 2 /* -W flag */ |
317 | #define G_WARN_ALL_OFF 4 /* -X flag */ | |
0453d815 | 318 | #define G_WARN_ONCE 8 /* set if 'once' ever enabled */ |
599cee73 PM |
319 | #define G_WARN_ALL_MASK (G_WARN_ALL_ON|G_WARN_ALL_OFF) |
320 | ||
a0714e2c | 321 | #define pWARN_STD NULL |
72dc9ed5 NC |
322 | #define pWARN_ALL (((STRLEN*)0)+1) /* use warnings 'all' */ |
323 | #define pWARN_NONE (((STRLEN*)0)+2) /* no warnings 'all' */ | |
599cee73 | 324 | |
d3a7d8c7 GS |
325 | #define specialWARN(x) ((x) == pWARN_STD || (x) == pWARN_ALL || \ |
326 | (x) == pWARN_NONE) | |
5f2d9966 DM |
327 | |
328 | /* if PL_warnhook is set to this value, then warnings die */ | |
06dcd5bf | 329 | #define PERL_WARNHOOK_FATAL (&PL_sv_placeholder) |
599cee73 PM |
330 | EOM |
331 | ||
c4a853d1 | 332 | my $offset = 0 ; |
d3a7d8c7 | 333 | |
c4a853d1 RS |
334 | valueWalk ($tree) ; |
335 | $index = orderValues(); | |
599cee73 | 336 | |
c4a853d1 | 337 | die <<EOM if $index > 255 ; |
12bcd1a6 | 338 | Too many warnings categories -- max is 255 |
c4a853d1 | 339 | rewrite packWARN* & unpackWARN* macros |
12bcd1a6 | 340 | EOM |
599cee73 | 341 | |
c4a853d1 | 342 | walk ($tree) ; |
0d658bf5 | 343 | |
c4a853d1 RS |
344 | $index *= 2 ; |
345 | $warn_size = int($index / 8) + ($index % 8 != 0) ; | |
599cee73 | 346 | |
c4a853d1 RS |
347 | my $k ; |
348 | my $last_ver = 0; | |
349 | foreach $k (sort { $a <=> $b } keys %ValueToName) { | |
350 | my ($name, $version) = @{ $ValueToName{$k} }; | |
351 | print $warn "\n/* Warnings Categories added in Perl $version */\n\n" | |
352 | if $last_ver != $version ; | |
353 | $name =~ y/:/_/; | |
3c3f8cd6 | 354 | print $warn tab(6, "#define WARN_$name"), " $k\n" ; |
c4a853d1 RS |
355 | $last_ver = $version ; |
356 | } | |
357 | print $warn "\n" ; | |
599cee73 | 358 | |
3c3f8cd6 AB |
359 | print $warn tab(6, '#define WARNsize'), " $warn_size\n" ; |
360 | print $warn tab(6, '#define WARN_ALLstring'), ' "', ('\125' x $warn_size) , "\"\n" ; | |
361 | print $warn tab(6, '#define WARN_NONEstring'), ' "', ('\0' x $warn_size) , "\"\n" ; | |
599cee73 | 362 | |
c4a853d1 | 363 | print $warn <<'EOM'; |
599cee73 | 364 | |
d5a71f30 GS |
365 | #define isLEXWARN_on (PL_curcop->cop_warnings != pWARN_STD) |
366 | #define isLEXWARN_off (PL_curcop->cop_warnings == pWARN_STD) | |
367 | #define isWARN_ONCE (PL_dowarn & (G_WARN_ON|G_WARN_ONCE)) | |
72dc9ed5 NC |
368 | #define isWARN_on(c,x) (IsSet((U8 *)(c + 1), 2*(x))) |
369 | #define isWARNf_on(c,x) (IsSet((U8 *)(c + 1), 2*(x)+1)) | |
370 | ||
371 | #define DUP_WARNINGS(p) \ | |
594cd643 NC |
372 | (specialWARN(p) ? (STRLEN*)(p) \ |
373 | : (STRLEN*)CopyD(p, PerlMemShared_malloc(sizeof(*p)+*p), sizeof(*p)+*p, \ | |
374 | char)) | |
d5a71f30 | 375 | |
f54ba1c2 | 376 | #define ckWARN(w) Perl_ckwarn(aTHX_ packWARN(w)) |
7c08c4c5 KW |
377 | |
378 | /* The w1, w2 ... should be independent warnings categories; one shouldn't be | |
379 | * a subcategory of any other */ | |
380 | ||
f54ba1c2 DM |
381 | #define ckWARN2(w1,w2) Perl_ckwarn(aTHX_ packWARN2(w1,w2)) |
382 | #define ckWARN3(w1,w2,w3) Perl_ckwarn(aTHX_ packWARN3(w1,w2,w3)) | |
383 | #define ckWARN4(w1,w2,w3,w4) Perl_ckwarn(aTHX_ packWARN4(w1,w2,w3,w4)) | |
384 | ||
385 | #define ckWARN_d(w) Perl_ckwarn_d(aTHX_ packWARN(w)) | |
386 | #define ckWARN2_d(w1,w2) Perl_ckwarn_d(aTHX_ packWARN2(w1,w2)) | |
387 | #define ckWARN3_d(w1,w2,w3) Perl_ckwarn_d(aTHX_ packWARN3(w1,w2,w3)) | |
388 | #define ckWARN4_d(w1,w2,w3,w4) Perl_ckwarn_d(aTHX_ packWARN4(w1,w2,w3,w4)) | |
12bcd1a6 | 389 | |
98fe6610 NC |
390 | #define WARNshift 8 |
391 | ||
3b9e3074 | 392 | #define packWARN(a) (a ) |
7c08c4c5 KW |
393 | |
394 | /* The a, b, ... should be independent warnings categories; one shouldn't be | |
395 | * a subcategory of any other */ | |
396 | ||
3b9e3074 SH |
397 | #define packWARN2(a,b) ((a) | ((b)<<8) ) |
398 | #define packWARN3(a,b,c) ((a) | ((b)<<8) | ((c)<<16) ) | |
399 | #define packWARN4(a,b,c,d) ((a) | ((b)<<8) | ((c)<<16) | ((d) <<24)) | |
12bcd1a6 PM |
400 | |
401 | #define unpackWARN1(x) ((x) & 0xFF) | |
402 | #define unpackWARN2(x) (((x) >>8) & 0xFF) | |
403 | #define unpackWARN3(x) (((x) >>16) & 0xFF) | |
404 | #define unpackWARN4(x) (((x) >>24) & 0xFF) | |
405 | ||
406 | #define ckDEAD(x) \ | |
407 | ( ! specialWARN(PL_curcop->cop_warnings) && \ | |
408 | ( isWARNf_on(PL_curcop->cop_warnings, WARN_ALL) || \ | |
409 | isWARNf_on(PL_curcop->cop_warnings, unpackWARN1(x)) || \ | |
410 | isWARNf_on(PL_curcop->cop_warnings, unpackWARN2(x)) || \ | |
411 | isWARNf_on(PL_curcop->cop_warnings, unpackWARN3(x)) || \ | |
412 | isWARNf_on(PL_curcop->cop_warnings, unpackWARN4(x)))) | |
413 | ||
4438c4b7 | 414 | /* end of file warnings.h */ |
599cee73 PM |
415 | EOM |
416 | ||
c4a853d1 RS |
417 | read_only_bottom_close_and_rename($warn); |
418 | } | |
599cee73 PM |
419 | |
420 | while (<DATA>) { | |
421 | last if /^KEYWORDS$/ ; | |
424a4936 | 422 | print $pm $_ ; |
599cee73 PM |
423 | } |
424 | ||
c4a853d1 | 425 | my $last_ver = 0; |
3c3f8cd6 | 426 | print $pm "our %Offsets = (" ; |
0d658bf5 PM |
427 | foreach my $k (sort { $a <=> $b } keys %ValueToName) { |
428 | my ($name, $version) = @{ $ValueToName{$k} }; | |
429 | $name = lc $name; | |
d3a7d8c7 | 430 | $k *= 2 ; |
0d658bf5 | 431 | if ( $last_ver != $version ) { |
424a4936 | 432 | print $pm "\n"; |
3c3f8cd6 AB |
433 | print $pm tab(6, " # Warnings Categories added in Perl $version"); |
434 | print $pm "\n"; | |
0d658bf5 | 435 | } |
3c3f8cd6 | 436 | print $pm tab(6, " '$name'"), "=> $k,\n" ; |
0d658bf5 | 437 | $last_ver = $version; |
d3a7d8c7 GS |
438 | } |
439 | ||
3c3f8cd6 | 440 | print $pm ");\n\n" ; |
d3a7d8c7 | 441 | |
424a4936 | 442 | print $pm "our %Bits = (\n" ; |
c4a853d1 | 443 | foreach my $k (sort keys %list) { |
599cee73 PM |
444 | |
445 | my $v = $list{$k} ; | |
446 | my @list = sort { $a <=> $b } @$v ; | |
447 | ||
3c3f8cd6 | 448 | print $pm tab(6, " '$k'"), '=> "', |
0ca4541c | 449 | mkHex($warn_size, map $_ * 2 , @list), |
599cee73 PM |
450 | '", # [', mkRange(@list), "]\n" ; |
451 | } | |
452 | ||
3c3f8cd6 | 453 | print $pm ");\n\n" ; |
599cee73 | 454 | |
424a4936 | 455 | print $pm "our %DeadBits = (\n" ; |
c4a853d1 | 456 | foreach my $k (sort keys %list) { |
599cee73 PM |
457 | |
458 | my $v = $list{$k} ; | |
459 | my @list = sort { $a <=> $b } @$v ; | |
460 | ||
3c3f8cd6 | 461 | print $pm tab(6, " '$k'"), '=> "', |
0ca4541c | 462 | mkHex($warn_size, map $_ * 2 + 1 , @list), |
599cee73 PM |
463 | '", # [', mkRange(@list), "]\n" ; |
464 | } | |
465 | ||
3c3f8cd6 AB |
466 | print $pm ");\n\n" ; |
467 | print $pm "# These are used by various things, including our own tests\n"; | |
468 | print $pm tab(6, 'our $NONE'), '= "', ('\0' x $warn_size) , "\";\n" ; | |
469 | print $pm tab(6, 'our $DEFAULT'), '= "', mkHex($warn_size, map $_ * 2, @def), | |
7fc874e8 | 470 | '", # [', mkRange(@def), "]\n" ; |
3c3f8cd6 AB |
471 | print $pm tab(6, 'our $LAST_BIT'), '= ' . "$index ;\n" ; |
472 | print $pm tab(6, 'our $BYTES'), '= ' . "$warn_size ;\n" ; | |
599cee73 | 473 | while (<DATA>) { |
effd17dc | 474 | if ($_ eq "=for warnings.pl tree-goes-here\n") { |
3c3f8cd6 | 475 | print $pm warningsTree($tree, " "); |
effd17dc DD |
476 | next; |
477 | } | |
424a4936 | 478 | print $pm $_ ; |
599cee73 PM |
479 | } |
480 | ||
ce716c52 | 481 | read_only_bottom_close_and_rename($pm); |
599cee73 PM |
482 | |
483 | __END__ | |
4438c4b7 | 484 | package warnings; |
599cee73 | 485 | |
2e4abf26 | 486 | our $VERSION = '1.32'; |
f2c3e829 RGS |
487 | |
488 | # Verify that we're called correctly so that warnings will work. | |
489 | # see also strict.pm. | |
5108dc18 | 490 | unless ( __FILE__ =~ /(^|[\/\\])\Q${\__PACKAGE__}\E\.pmc?$/ ) { |
f2c3e829 | 491 | my (undef, $f, $l) = caller; |
5108dc18 | 492 | die("Incorrect use of pragma '${\__PACKAGE__}' at $f line $l.\n"); |
f2c3e829 | 493 | } |
b75c8c73 | 494 | |
effd17dc DD |
495 | KEYWORDS |
496 | ||
3c3f8cd6 | 497 | our $All = "" ; vec($All, $Offsets{'all'}, 2) = 3 ; |
effd17dc DD |
498 | |
499 | sub Croaker | |
500 | { | |
501 | require Carp; # this initializes %CarpInternal | |
502 | local $Carp::CarpInternal{'warnings'}; | |
503 | delete $Carp::CarpInternal{'warnings'}; | |
504 | Carp::croak(@_); | |
505 | } | |
506 | ||
507 | sub _bits { | |
508 | my $mask = shift ; | |
509 | my $catmask ; | |
510 | my $fatal = 0 ; | |
511 | my $no_fatal = 0 ; | |
512 | ||
513 | foreach my $word ( @_ ) { | |
514 | if ($word eq 'FATAL') { | |
515 | $fatal = 1; | |
516 | $no_fatal = 0; | |
517 | } | |
518 | elsif ($word eq 'NONFATAL') { | |
519 | $fatal = 0; | |
520 | $no_fatal = 1; | |
521 | } | |
522 | elsif ($catmask = $Bits{$word}) { | |
523 | $mask |= $catmask ; | |
524 | $mask |= $DeadBits{$word} if $fatal ; | |
525 | $mask &= ~($DeadBits{$word}|$All) if $no_fatal ; | |
526 | } | |
527 | else | |
56873d42 | 528 | { Croaker("Unknown warnings category '$word'")} |
effd17dc DD |
529 | } |
530 | ||
531 | return $mask ; | |
532 | } | |
533 | ||
534 | sub bits | |
535 | { | |
536 | # called from B::Deparse.pm | |
537 | push @_, 'all' unless @_ ; | |
538 | return _bits(undef, @_) ; | |
539 | } | |
540 | ||
541 | sub import | |
542 | { | |
543 | shift; | |
544 | ||
545 | my $mask = ${^WARNING_BITS} // ($^W ? $Bits{all} : $DEFAULT) ; | |
546 | ||
547 | if (vec($mask, $Offsets{'all'}, 1)) { | |
56873d42 DD |
548 | $mask |= $Bits{'all'} ; |
549 | $mask |= $DeadBits{'all'} if vec($mask, $Offsets{'all'}+1, 1); | |
effd17dc DD |
550 | } |
551 | ||
552 | # append 'all' when implied (after a lone "FATAL" or "NONFATAL") | |
553 | push @_, 'all' if @_==1 && ( $_[0] eq 'FATAL' || $_[0] eq 'NONFATAL' ); | |
554 | ||
555 | # Empty @_ is equivalent to @_ = 'all' ; | |
556 | ${^WARNING_BITS} = @_ ? _bits($mask, @_) : $mask | $Bits{all} ; | |
557 | } | |
558 | ||
559 | sub unimport | |
560 | { | |
561 | shift; | |
562 | ||
563 | my $catmask ; | |
564 | my $mask = ${^WARNING_BITS} // ($^W ? $Bits{all} : $DEFAULT) ; | |
565 | ||
566 | if (vec($mask, $Offsets{'all'}, 1)) { | |
56873d42 DD |
567 | $mask |= $Bits{'all'} ; |
568 | $mask |= $DeadBits{'all'} if vec($mask, $Offsets{'all'}+1, 1); | |
effd17dc DD |
569 | } |
570 | ||
571 | # append 'all' when implied (empty import list or after a lone "FATAL") | |
572 | push @_, 'all' if !@_ || @_==1 && $_[0] eq 'FATAL'; | |
573 | ||
574 | foreach my $word ( @_ ) { | |
575 | if ($word eq 'FATAL') { | |
576 | next; | |
577 | } | |
578 | elsif ($catmask = $Bits{$word}) { | |
579 | $mask &= ~($catmask | $DeadBits{$word} | $All); | |
580 | } | |
581 | else | |
56873d42 | 582 | { Croaker("Unknown warnings category '$word'")} |
effd17dc DD |
583 | } |
584 | ||
585 | ${^WARNING_BITS} = $mask ; | |
586 | } | |
587 | ||
588 | my %builtin_type; @builtin_type{qw(SCALAR ARRAY HASH CODE REF GLOB LVALUE Regexp)} = (); | |
589 | ||
590 | sub MESSAGE () { 4 }; | |
591 | sub FATAL () { 2 }; | |
592 | sub NORMAL () { 1 }; | |
593 | ||
594 | sub __chk | |
595 | { | |
596 | my $category ; | |
597 | my $offset ; | |
598 | my $isobj = 0 ; | |
599 | my $wanted = shift; | |
600 | my $has_message = $wanted & MESSAGE; | |
601 | ||
602 | unless (@_ == 1 || @_ == ($has_message ? 2 : 0)) { | |
603 | my $sub = (caller 1)[3]; | |
604 | my $syntax = $has_message ? "[category,] 'message'" : '[category]'; | |
605 | Croaker("Usage: $sub($syntax)"); | |
606 | } | |
607 | ||
608 | my $message = pop if $has_message; | |
609 | ||
610 | if (@_) { | |
56873d42 DD |
611 | # check the category supplied. |
612 | $category = shift ; | |
613 | if (my $type = ref $category) { | |
614 | Croaker("not an object") | |
615 | if exists $builtin_type{$type}; | |
effd17dc | 616 | $category = $type; |
56873d42 DD |
617 | $isobj = 1 ; |
618 | } | |
619 | $offset = $Offsets{$category}; | |
620 | Croaker("Unknown warnings category '$category'") | |
effd17dc DD |
621 | unless defined $offset; |
622 | } | |
623 | else { | |
56873d42 DD |
624 | $category = (caller(1))[0] ; |
625 | $offset = $Offsets{$category}; | |
626 | Croaker("package '$category' not registered for warnings") | |
effd17dc DD |
627 | unless defined $offset ; |
628 | } | |
629 | ||
630 | my $i; | |
631 | ||
632 | if ($isobj) { | |
56873d42 DD |
633 | my $pkg; |
634 | $i = 2; | |
635 | while (do { { package DB; $pkg = (caller($i++))[0] } } ) { | |
636 | last unless @DB::args && $DB::args[0] =~ /^$category=/ ; | |
637 | } | |
effd17dc DD |
638 | $i -= 2 ; |
639 | } | |
640 | else { | |
56873d42 | 641 | $i = _error_loc(); # see where Carp will allocate the error |
effd17dc DD |
642 | } |
643 | ||
644 | # Default to 0 if caller returns nothing. Default to $DEFAULT if it | |
645 | # explicitly returns undef. | |
646 | my(@callers_bitmask) = (caller($i))[9] ; | |
647 | my $callers_bitmask = | |
648 | @callers_bitmask ? $callers_bitmask[0] // $DEFAULT : 0 ; | |
649 | ||
650 | my @results; | |
651 | foreach my $type (FATAL, NORMAL) { | |
652 | next unless $wanted & $type; | |
653 | ||
654 | push @results, (vec($callers_bitmask, $offset + $type - 1, 1) || | |
655 | vec($callers_bitmask, $Offsets{'all'} + $type - 1, 1)); | |
656 | } | |
657 | ||
658 | # &enabled and &fatal_enabled | |
659 | return $results[0] unless $has_message; | |
660 | ||
661 | # &warnif, and the category is neither enabled as warning nor as fatal | |
662 | return if $wanted == (NORMAL | FATAL | MESSAGE) | |
663 | && !($results[0] || $results[1]); | |
664 | ||
665 | require Carp; | |
666 | Carp::croak($message) if $results[0]; | |
667 | # will always get here for &warn. will only get here for &warnif if the | |
668 | # category is enabled | |
669 | Carp::carp($message); | |
670 | } | |
671 | ||
672 | sub _mkMask | |
673 | { | |
674 | my ($bit) = @_; | |
675 | my $mask = ""; | |
676 | ||
677 | vec($mask, $bit, 1) = 1; | |
678 | return $mask; | |
679 | } | |
680 | ||
681 | sub register_categories | |
682 | { | |
683 | my @names = @_; | |
684 | ||
685 | for my $name (@names) { | |
686 | if (! defined $Bits{$name}) { | |
687 | $Bits{$name} = _mkMask($LAST_BIT); | |
688 | vec($Bits{'all'}, $LAST_BIT, 1) = 1; | |
689 | $Offsets{$name} = $LAST_BIT ++; | |
690 | foreach my $k (keys %Bits) { | |
691 | vec($Bits{$k}, $LAST_BIT, 1) = 0; | |
692 | } | |
693 | $DeadBits{$name} = _mkMask($LAST_BIT); | |
694 | vec($DeadBits{'all'}, $LAST_BIT++, 1) = 1; | |
695 | } | |
696 | } | |
697 | } | |
698 | ||
699 | sub _error_loc { | |
700 | require Carp; | |
701 | goto &Carp::short_error_loc; # don't introduce another stack frame | |
702 | } | |
703 | ||
704 | sub enabled | |
705 | { | |
706 | return __chk(NORMAL, @_); | |
707 | } | |
708 | ||
709 | sub fatal_enabled | |
710 | { | |
711 | return __chk(FATAL, @_); | |
712 | } | |
713 | ||
714 | sub warn | |
715 | { | |
716 | return __chk(FATAL | MESSAGE, @_); | |
717 | } | |
718 | ||
719 | sub warnif | |
720 | { | |
721 | return __chk(NORMAL | FATAL | MESSAGE, @_); | |
722 | } | |
723 | ||
724 | # These are not part of any public interface, so we can delete them to save | |
725 | # space. | |
726 | delete @warnings::{qw(NORMAL FATAL MESSAGE)}; | |
727 | ||
728 | 1; | |
729 | __END__ | |
599cee73 PM |
730 | =head1 NAME |
731 | ||
4438c4b7 | 732 | warnings - Perl pragma to control optional warnings |
599cee73 PM |
733 | |
734 | =head1 SYNOPSIS | |
735 | ||
4438c4b7 JH |
736 | use warnings; |
737 | no warnings; | |
599cee73 | 738 | |
4438c4b7 JH |
739 | use warnings "all"; |
740 | no warnings "all"; | |
599cee73 | 741 | |
d3a7d8c7 GS |
742 | use warnings::register; |
743 | if (warnings::enabled()) { | |
744 | warnings::warn("some warning"); | |
745 | } | |
746 | ||
747 | if (warnings::enabled("void")) { | |
e476b1b5 GS |
748 | warnings::warn("void", "some warning"); |
749 | } | |
750 | ||
7e6d00f8 PM |
751 | if (warnings::enabled($object)) { |
752 | warnings::warn($object, "some warning"); | |
753 | } | |
754 | ||
721f911b PM |
755 | warnings::warnif("some warning"); |
756 | warnings::warnif("void", "some warning"); | |
757 | warnings::warnif($object, "some warning"); | |
7e6d00f8 | 758 | |
599cee73 PM |
759 | =head1 DESCRIPTION |
760 | ||
188c4f6f RS |
761 | The C<warnings> pragma gives control over which warnings are enabled in |
762 | which parts of a Perl program. It's a more flexible alternative for | |
763 | both the command line flag B<-w> and the equivalent Perl variable, | |
764 | C<$^W>. | |
33edcb80 RS |
765 | |
766 | This pragma works just like the C<strict> pragma. | |
767 | This means that the scope of the warning pragma is limited to the | |
768 | enclosing block. It also means that the pragma setting will not | |
769 | leak across files (via C<use>, C<require> or C<do>). This allows | |
770 | authors to independently define the degree of warning checks that will | |
771 | be applied to their module. | |
772 | ||
773 | By default, optional warnings are disabled, so any legacy code that | |
774 | doesn't attempt to control the warnings will work unchanged. | |
775 | ||
3c3f8cd6 | 776 | All warnings are enabled in a block by either of these: |
33edcb80 RS |
777 | |
778 | use warnings; | |
779 | use warnings 'all'; | |
780 | ||
3c3f8cd6 | 781 | Similarly all warnings are disabled in a block by either of these: |
33edcb80 RS |
782 | |
783 | no warnings; | |
784 | no warnings 'all'; | |
785 | ||
786 | For example, consider the code below: | |
787 | ||
788 | use warnings; | |
789 | my @a; | |
790 | { | |
791 | no warnings; | |
792 | my $b = @a[0]; | |
793 | } | |
794 | my $c = @a[0]; | |
795 | ||
796 | The code in the enclosing block has warnings enabled, but the inner | |
797 | block has them disabled. In this case that means the assignment to the | |
798 | scalar C<$c> will trip the C<"Scalar value @a[0] better written as $a[0]"> | |
799 | warning, but the assignment to the scalar C<$b> will not. | |
800 | ||
801 | =head2 Default Warnings and Optional Warnings | |
802 | ||
803 | Before the introduction of lexical warnings, Perl had two classes of | |
56873d42 | 804 | warnings: mandatory and optional. |
33edcb80 RS |
805 | |
806 | As its name suggests, if your code tripped a mandatory warning, you | |
807 | would get a warning whether you wanted it or not. | |
808 | For example, the code below would always produce an C<"isn't numeric"> | |
809 | warning about the "2:". | |
810 | ||
811 | my $a = "2:" + 3; | |
812 | ||
813 | With the introduction of lexical warnings, mandatory warnings now become | |
814 | I<default> warnings. The difference is that although the previously | |
815 | mandatory warnings are still enabled by default, they can then be | |
816 | subsequently enabled or disabled with the lexical warning pragma. For | |
817 | example, in the code below, an C<"isn't numeric"> warning will only | |
818 | be reported for the C<$a> variable. | |
819 | ||
820 | my $a = "2:" + 3; | |
821 | no warnings; | |
822 | my $b = "2:" + 3; | |
823 | ||
824 | Note that neither the B<-w> flag or the C<$^W> can be used to | |
825 | disable/enable default warnings. They are still mandatory in this case. | |
826 | ||
827 | =head2 What's wrong with B<-w> and C<$^W> | |
828 | ||
829 | Although very useful, the big problem with using B<-w> on the command | |
830 | line to enable warnings is that it is all or nothing. Take the typical | |
831 | scenario when you are writing a Perl program. Parts of the code you | |
832 | will write yourself, but it's very likely that you will make use of | |
833 | pre-written Perl modules. If you use the B<-w> flag in this case, you | |
834 | end up enabling warnings in pieces of code that you haven't written. | |
835 | ||
836 | Similarly, using C<$^W> to either disable or enable blocks of code is | |
837 | fundamentally flawed. For a start, say you want to disable warnings in | |
838 | a block of code. You might expect this to be enough to do the trick: | |
839 | ||
840 | { | |
841 | local ($^W) = 0; | |
842 | my $a =+ 2; | |
843 | my $b; chop $b; | |
844 | } | |
845 | ||
846 | When this code is run with the B<-w> flag, a warning will be produced | |
847 | for the C<$a> line: C<"Reversed += operator">. | |
848 | ||
849 | The problem is that Perl has both compile-time and run-time warnings. To | |
850 | disable compile-time warnings you need to rewrite the code like this: | |
851 | ||
852 | { | |
853 | BEGIN { $^W = 0 } | |
854 | my $a =+ 2; | |
855 | my $b; chop $b; | |
856 | } | |
857 | ||
858 | The other big problem with C<$^W> is the way you can inadvertently | |
859 | change the warning setting in unexpected places in your code. For example, | |
860 | when the code below is run (without the B<-w> flag), the second call | |
861 | to C<doit> will trip a C<"Use of uninitialized value"> warning, whereas | |
862 | the first will not. | |
863 | ||
864 | sub doit | |
865 | { | |
866 | my $b; chop $b; | |
867 | } | |
868 | ||
869 | doit(); | |
870 | ||
871 | { | |
872 | local ($^W) = 1; | |
873 | doit() | |
874 | } | |
875 | ||
876 | This is a side-effect of C<$^W> being dynamically scoped. | |
877 | ||
878 | Lexical warnings get around these limitations by allowing finer control | |
879 | over where warnings can or can't be tripped. | |
880 | ||
881 | =head2 Controlling Warnings from the Command Line | |
882 | ||
883 | There are three Command Line flags that can be used to control when | |
884 | warnings are (or aren't) produced: | |
885 | ||
886 | =over 5 | |
887 | ||
888 | =item B<-w> | |
889 | X<-w> | |
890 | ||
891 | This is the existing flag. If the lexical warnings pragma is B<not> | |
892 | used in any of you code, or any of the modules that you use, this flag | |
893 | will enable warnings everywhere. See L<Backward Compatibility> for | |
894 | details of how this flag interacts with lexical warnings. | |
895 | ||
896 | =item B<-W> | |
897 | X<-W> | |
898 | ||
3c3f8cd6 | 899 | If the B<-W> flag is used on the command line, it will enable all warnings |
33edcb80 RS |
900 | throughout the program regardless of whether warnings were disabled |
901 | locally using C<no warnings> or C<$^W =0>. | |
902 | This includes all files that get | |
903 | included via C<use>, C<require> or C<do>. | |
904 | Think of it as the Perl equivalent of the "lint" command. | |
905 | ||
906 | =item B<-X> | |
907 | X<-X> | |
908 | ||
3c3f8cd6 | 909 | Does the exact opposite to the B<-W> flag, i.e. it disables all warnings. |
33edcb80 RS |
910 | |
911 | =back | |
912 | ||
913 | =head2 Backward Compatibility | |
914 | ||
915 | If you are used to working with a version of Perl prior to the | |
916 | introduction of lexically scoped warnings, or have code that uses both | |
917 | lexical warnings and C<$^W>, this section will describe how they interact. | |
918 | ||
919 | How Lexical Warnings interact with B<-w>/C<$^W>: | |
920 | ||
921 | =over 5 | |
922 | ||
923 | =item 1. | |
924 | ||
925 | If none of the three command line flags (B<-w>, B<-W> or B<-X>) that | |
926 | control warnings is used and neither C<$^W> nor the C<warnings> pragma | |
927 | are used, then default warnings will be enabled and optional warnings | |
928 | disabled. | |
929 | This means that legacy code that doesn't attempt to control the warnings | |
930 | will work unchanged. | |
931 | ||
932 | =item 2. | |
933 | ||
934 | The B<-w> flag just sets the global C<$^W> variable as in 5.005. This | |
935 | means that any legacy code that currently relies on manipulating C<$^W> | |
56873d42 | 936 | to control warning behavior will still work as is. |
33edcb80 RS |
937 | |
938 | =item 3. | |
939 | ||
940 | Apart from now being a boolean, the C<$^W> variable operates in exactly | |
941 | the same horrible uncontrolled global way, except that it cannot | |
942 | disable/enable default warnings. | |
943 | ||
944 | =item 4. | |
945 | ||
946 | If a piece of code is under the control of the C<warnings> pragma, | |
947 | both the C<$^W> variable and the B<-w> flag will be ignored for the | |
948 | scope of the lexical warning. | |
949 | ||
950 | =item 5. | |
951 | ||
952 | The only way to override a lexical warnings setting is with the B<-W> | |
953 | or B<-X> command line flags. | |
954 | ||
955 | =back | |
956 | ||
957 | The combined effect of 3 & 4 is that it will allow code which uses | |
958 | the C<warnings> pragma to control the warning behavior of $^W-type | |
959 | code (using a C<local $^W=0>) if it really wants to, but not vice-versa. | |
960 | ||
961 | =head2 Category Hierarchy | |
962 | X<warning, categories> | |
963 | ||
964 | A hierarchy of "categories" have been defined to allow groups of warnings | |
965 | to be enabled/disabled in isolation. | |
966 | ||
967 | The current hierarchy is: | |
968 | ||
969 | =for warnings.pl tree-goes-here | |
970 | ||
971 | Just like the "strict" pragma any of these categories can be combined | |
972 | ||
973 | use warnings qw(void redefine); | |
974 | no warnings qw(io syntax untie); | |
975 | ||
976 | Also like the "strict" pragma, if there is more than one instance of the | |
56873d42 | 977 | C<warnings> pragma in a given scope the cumulative effect is additive. |
33edcb80 RS |
978 | |
979 | use warnings qw(void); # only "void" warnings enabled | |
980 | ... | |
981 | use warnings qw(io); # only "void" & "io" warnings enabled | |
982 | ... | |
983 | no warnings qw(void); # only "io" warnings enabled | |
984 | ||
985 | To determine which category a specific warning has been assigned to see | |
986 | L<perldiag>. | |
987 | ||
988 | Note: Before Perl 5.8.0, the lexical warnings category "deprecated" was a | |
989 | sub-category of the "syntax" category. It is now a top-level category | |
990 | in its own right. | |
991 | ||
3664866e AB |
992 | Note: Before 5.21.0, the "missing" lexical warnings category was |
993 | internally defined to be the same as the "uninitialized" category. It | |
994 | is now a top-level category in its own right. | |
995 | ||
33edcb80 RS |
996 | =head2 Fatal Warnings |
997 | X<warning, fatal> | |
998 | ||
2e4abf26 DG |
999 | The presence of the word "FATAL" in the category list will escalate |
1000 | warnings in those categories into fatal errors in that lexical scope. | |
1001 | ||
1002 | B<NOTE:> FATAL warnings should be used with care, particularly | |
1003 | C<< FATAL => 'all' >>. | |
1004 | ||
1005 | Libraries using L<warnings::warn|/FUNCTIONS> for custom warning categories | |
1006 | generally don't expect L<warnings::warn|/FUNCTIONS> to be fatal and can wind up | |
1007 | in an unexpected state as a result. For XS modules issuing categorized | |
1008 | warnings, such unanticipated exceptions could also expose memory leak bugs. | |
1009 | ||
1010 | Moreover, the Perl interpreter itself has had serious bugs involving | |
1011 | fatalized warnings. For a summary of resolved and unresolved problems as | |
1012 | of January 2015, please see | |
1013 | L<this perl5-porters post|http://www.nntp.perl.org/group/perl.perl5.porters/2015/01/msg225235.html>. | |
1014 | ||
1015 | While some developers find fatalizing some warnings to be a useful | |
1016 | defensive programming technique, using C<< FATAL => 'all' >> to fatalize | |
1017 | all possible warning categories -- including custom ones -- is particularly | |
1018 | risky. Therefore, the use of C<< FATAL => 'all' >> is | |
1019 | L<discouraged|perlpolicy/discouraged>. | |
1020 | ||
1021 | The L<strictures|strictures/VERSION-2> module on CPAN offers one example of | |
1022 | a warnings subset that the module's authors believe is relatively safe to | |
1023 | fatalize. | |
1024 | ||
1025 | B<NOTE:> users of FATAL warnings, especially those using | |
1026 | C<< FATAL => 'all' >>, should be fully aware that they are risking future | |
1027 | portability of their programs by doing so. Perl makes absolutely no | |
1028 | commitments to not introduce new warnings or warnings categories in the | |
1029 | future; indeed, we explicitly reserve the right to do so. Code that may | |
1030 | not warn now may warn in a future release of Perl if the Perl5 development | |
1031 | team deems it in the best interests of the community to do so. Should code | |
1032 | using FATAL warnings break due to the introduction of a new warning we will | |
1033 | NOT consider it an incompatible change. Users of FATAL warnings should | |
1034 | take special caution during upgrades to check to see if their code triggers | |
1035 | any new warnings and should pay particular attention to the fine print of | |
1036 | the documentation of the features they use to ensure they do not exploit | |
1037 | features that are documented as risky, deprecated, or unspecified, or where | |
1038 | the documentation says "so don't do that", or anything with the same sense | |
1039 | and spirit. Use of such features in combination with FATAL warnings is | |
1040 | ENTIRELY AT THE USER'S RISK. | |
1041 | ||
1042 | The following documentation describes how to use FATAL warnings but the | |
1043 | perl5 porters strongly recommend that you understand the risks before doing | |
1044 | so, especially for library code intended for use by others, as there is no | |
1045 | way for downstream users to change the choice of fatal categories. | |
1046 | ||
1047 | In the code below, the use of C<time>, C<length> | |
33edcb80 RS |
1048 | and C<join> can all produce a C<"Useless use of xxx in void context"> |
1049 | warning. | |
1050 | ||
1051 | use warnings; | |
1052 | ||
1053 | time; | |
1054 | ||
1055 | { | |
1056 | use warnings FATAL => qw(void); | |
1057 | length "abc"; | |
1058 | } | |
1059 | ||
1060 | join "", 1,2,3; | |
1061 | ||
1062 | print "done\n"; | |
1063 | ||
1064 | When run it produces this output | |
1065 | ||
1066 | Useless use of time in void context at fatal line 3. | |
56873d42 | 1067 | Useless use of length in void context at fatal line 7. |
33edcb80 RS |
1068 | |
1069 | The scope where C<length> is used has escalated the C<void> warnings | |
1070 | category into a fatal error, so the program terminates immediately when it | |
1071 | encounters the warning. | |
1072 | ||
1073 | To explicitly turn off a "FATAL" warning you just disable the warning | |
1074 | it is associated with. So, for example, to disable the "void" warning | |
1075 | in the example above, either of these will do the trick: | |
1076 | ||
1077 | no warnings qw(void); | |
1078 | no warnings FATAL => qw(void); | |
1079 | ||
1080 | If you want to downgrade a warning that has been escalated into a fatal | |
1081 | error back to a normal warning, you can use the "NONFATAL" keyword. For | |
1082 | example, the code below will promote all warnings into fatal errors, | |
1083 | except for those in the "syntax" category. | |
1084 | ||
1085 | use warnings FATAL => 'all', NONFATAL => 'syntax'; | |
1086 | ||
1087 | As of Perl 5.20, instead of C<< use warnings FATAL => 'all'; >> you can | |
1088 | use: | |
1089 | ||
1090 | use v5.20; # Perl 5.20 or greater is required for the following | |
1091 | use warnings 'FATAL'; # short form of "use warnings FATAL => 'all';" | |
1092 | ||
1093 | If you want your program to be compatible with versions of Perl before | |
1094 | 5.20, you must use C<< use warnings FATAL => 'all'; >> instead. (In | |
1095 | previous versions of Perl, the behavior of the statements | |
1096 | C<< use warnings 'FATAL'; >>, C<< use warnings 'NONFATAL'; >> and | |
1097 | C<< no warnings 'FATAL'; >> was unspecified; they did not behave as if | |
1098 | they included the C<< => 'all' >> portion. As of 5.20, they do.) | |
1099 | ||
33edcb80 RS |
1100 | =head2 Reporting Warnings from a Module |
1101 | X<warning, reporting> X<warning, registering> | |
1102 | ||
1103 | The C<warnings> pragma provides a number of functions that are useful for | |
1104 | module authors. These are used when you want to report a module-specific | |
1105 | warning to a calling module has enabled warnings via the C<warnings> | |
1106 | pragma. | |
1107 | ||
1108 | Consider the module C<MyMod::Abc> below. | |
1109 | ||
1110 | package MyMod::Abc; | |
1111 | ||
1112 | use warnings::register; | |
1113 | ||
1114 | sub open { | |
1115 | my $path = shift; | |
1116 | if ($path !~ m#^/#) { | |
1117 | warnings::warn("changing relative path to /var/abc") | |
1118 | if warnings::enabled(); | |
1119 | $path = "/var/abc/$path"; | |
1120 | } | |
1121 | } | |
1122 | ||
1123 | 1; | |
1124 | ||
1125 | The call to C<warnings::register> will create a new warnings category | |
1126 | called "MyMod::Abc", i.e. the new category name matches the current | |
1127 | package name. The C<open> function in the module will display a warning | |
1128 | message if it gets given a relative path as a parameter. This warnings | |
1129 | will only be displayed if the code that uses C<MyMod::Abc> has actually | |
1130 | enabled them with the C<warnings> pragma like below. | |
1131 | ||
1132 | use MyMod::Abc; | |
1133 | use warnings 'MyMod::Abc'; | |
1134 | ... | |
1135 | abc::open("../fred.txt"); | |
1136 | ||
1137 | It is also possible to test whether the pre-defined warnings categories are | |
1138 | set in the calling module with the C<warnings::enabled> function. Consider | |
1139 | this snippet of code: | |
1140 | ||
1141 | package MyMod::Abc; | |
1142 | ||
1143 | sub open { | |
56873d42 | 1144 | warnings::warnif("deprecated", |
33edcb80 RS |
1145 | "open is deprecated, use new instead"); |
1146 | new(@_); | |
1147 | } | |
1148 | ||
1149 | sub new | |
1150 | ... | |
1151 | 1; | |
1152 | ||
1153 | The function C<open> has been deprecated, so code has been included to | |
1154 | display a warning message whenever the calling module has (at least) the | |
1155 | "deprecated" warnings category enabled. Something like this, say. | |
1156 | ||
1157 | use warnings 'deprecated'; | |
1158 | use MyMod::Abc; | |
1159 | ... | |
1160 | MyMod::Abc::open($filename); | |
1161 | ||
1162 | Either the C<warnings::warn> or C<warnings::warnif> function should be | |
1163 | used to actually display the warnings message. This is because they can | |
1164 | make use of the feature that allows warnings to be escalated into fatal | |
1165 | errors. So in this case | |
1166 | ||
1167 | use MyMod::Abc; | |
1168 | use warnings FATAL => 'MyMod::Abc'; | |
1169 | ... | |
1170 | MyMod::Abc::open('../fred.txt'); | |
1171 | ||
1172 | the C<warnings::warnif> function will detect this and die after | |
1173 | displaying the warning message. | |
1174 | ||
1175 | The three warnings functions, C<warnings::warn>, C<warnings::warnif> | |
1176 | and C<warnings::enabled> can optionally take an object reference in place | |
1177 | of a category name. In this case the functions will use the class name | |
1178 | of the object as the warnings category. | |
1179 | ||
1180 | Consider this example: | |
1181 | ||
1182 | package Original; | |
1183 | ||
1184 | no warnings; | |
1185 | use warnings::register; | |
1186 | ||
1187 | sub new | |
1188 | { | |
1189 | my $class = shift; | |
1190 | bless [], $class; | |
1191 | } | |
1192 | ||
1193 | sub check | |
1194 | { | |
1195 | my $self = shift; | |
1196 | my $value = shift; | |
1197 | ||
1198 | if ($value % 2 && warnings::enabled($self)) | |
1199 | { warnings::warn($self, "Odd numbers are unsafe") } | |
1200 | } | |
1201 | ||
1202 | sub doit | |
1203 | { | |
1204 | my $self = shift; | |
1205 | my $value = shift; | |
1206 | $self->check($value); | |
1207 | # ... | |
1208 | } | |
1209 | ||
1210 | 1; | |
1211 | ||
1212 | package Derived; | |
1213 | ||
1214 | use warnings::register; | |
1215 | use Original; | |
1216 | our @ISA = qw( Original ); | |
1217 | sub new | |
1218 | { | |
1219 | my $class = shift; | |
1220 | bless [], $class; | |
1221 | } | |
1222 | ||
1223 | ||
1224 | 1; | |
1225 | ||
56873d42 | 1226 | The code below makes use of both modules, but it only enables warnings from |
33edcb80 RS |
1227 | C<Derived>. |
1228 | ||
1229 | use Original; | |
1230 | use Derived; | |
1231 | use warnings 'Derived'; | |
1232 | my $a = Original->new(); | |
1233 | $a->doit(1); | |
1234 | my $b = Derived->new(); | |
1235 | $a->doit(1); | |
1236 | ||
1237 | When this code is run only the C<Derived> object, C<$b>, will generate | |
56873d42 | 1238 | a warning. |
33edcb80 RS |
1239 | |
1240 | Odd numbers are unsafe at main.pl line 7 | |
1241 | ||
1242 | Notice also that the warning is reported at the line where the object is first | |
1243 | used. | |
1244 | ||
1245 | When registering new categories of warning, you can supply more names to | |
1246 | warnings::register like this: | |
1247 | ||
1248 | package MyModule; | |
1249 | use warnings::register qw(format precision); | |
1250 | ||
1251 | ... | |
fe2e802c | 1252 | |
33edcb80 | 1253 | warnings::warnif('MyModule::format', '...'); |
599cee73 | 1254 | |
33edcb80 | 1255 | =head1 FUNCTIONS |
e476b1b5 GS |
1256 | |
1257 | =over 4 | |
1258 | ||
d3a7d8c7 GS |
1259 | =item use warnings::register |
1260 | ||
7e6d00f8 PM |
1261 | Creates a new warnings category with the same name as the package where |
1262 | the call to the pragma is used. | |
1263 | ||
1264 | =item warnings::enabled() | |
1265 | ||
1266 | Use the warnings category with the same name as the current package. | |
1267 | ||
1268 | Return TRUE if that warnings category is enabled in the calling module. | |
1269 | Otherwise returns FALSE. | |
1270 | ||
1271 | =item warnings::enabled($category) | |
1272 | ||
1273 | Return TRUE if the warnings category, C<$category>, is enabled in the | |
1274 | calling module. | |
1275 | Otherwise returns FALSE. | |
1276 | ||
1277 | =item warnings::enabled($object) | |
1278 | ||
1279 | Use the name of the class for the object reference, C<$object>, as the | |
1280 | warnings category. | |
1281 | ||
1282 | Return TRUE if that warnings category is enabled in the first scope | |
1283 | where the object is used. | |
1284 | Otherwise returns FALSE. | |
1285 | ||
ec983580 AR |
1286 | =item warnings::fatal_enabled() |
1287 | ||
1288 | Return TRUE if the warnings category with the same name as the current | |
1289 | package has been set to FATAL in the calling module. | |
1290 | Otherwise returns FALSE. | |
1291 | ||
1292 | =item warnings::fatal_enabled($category) | |
1293 | ||
1294 | Return TRUE if the warnings category C<$category> has been set to FATAL in | |
1295 | the calling module. | |
1296 | Otherwise returns FALSE. | |
1297 | ||
1298 | =item warnings::fatal_enabled($object) | |
1299 | ||
1300 | Use the name of the class for the object reference, C<$object>, as the | |
1301 | warnings category. | |
1302 | ||
1303 | Return TRUE if that warnings category has been set to FATAL in the first | |
1304 | scope where the object is used. | |
1305 | Otherwise returns FALSE. | |
1306 | ||
7e6d00f8 PM |
1307 | =item warnings::warn($message) |
1308 | ||
1309 | Print C<$message> to STDERR. | |
1310 | ||
1311 | Use the warnings category with the same name as the current package. | |
1312 | ||
1313 | If that warnings category has been set to "FATAL" in the calling module | |
1314 | then die. Otherwise return. | |
1315 | ||
1316 | =item warnings::warn($category, $message) | |
1317 | ||
1318 | Print C<$message> to STDERR. | |
1319 | ||
1320 | If the warnings category, C<$category>, has been set to "FATAL" in the | |
1321 | calling module then die. Otherwise return. | |
d3a7d8c7 | 1322 | |
7e6d00f8 | 1323 | =item warnings::warn($object, $message) |
e476b1b5 | 1324 | |
7e6d00f8 | 1325 | Print C<$message> to STDERR. |
e476b1b5 | 1326 | |
7e6d00f8 PM |
1327 | Use the name of the class for the object reference, C<$object>, as the |
1328 | warnings category. | |
e476b1b5 | 1329 | |
7e6d00f8 PM |
1330 | If that warnings category has been set to "FATAL" in the scope where C<$object> |
1331 | is first used then die. Otherwise return. | |
599cee73 | 1332 | |
e476b1b5 | 1333 | |
7e6d00f8 PM |
1334 | =item warnings::warnif($message) |
1335 | ||
1336 | Equivalent to: | |
1337 | ||
1338 | if (warnings::enabled()) | |
1339 | { warnings::warn($message) } | |
1340 | ||
1341 | =item warnings::warnif($category, $message) | |
1342 | ||
1343 | Equivalent to: | |
1344 | ||
1345 | if (warnings::enabled($category)) | |
1346 | { warnings::warn($category, $message) } | |
1347 | ||
1348 | =item warnings::warnif($object, $message) | |
1349 | ||
1350 | Equivalent to: | |
1351 | ||
1352 | if (warnings::enabled($object)) | |
1353 | { warnings::warn($object, $message) } | |
d3a7d8c7 | 1354 | |
5e7ad92a | 1355 | =item warnings::register_categories(@names) |
13781810 FR |
1356 | |
1357 | This registers warning categories for the given names and is primarily for | |
d2ec25a5 | 1358 | use by the warnings::register pragma. |
13781810 | 1359 | |
e476b1b5 GS |
1360 | =back |
1361 | ||
d2ec25a5 | 1362 | See also L<perlmodlib/Pragmatic Modules> and L<perldiag>. |
599cee73 PM |
1363 | |
1364 | =cut |