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a0ed51b3
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1/* utf8.c
2 *
1129b882 3 * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
b94e2f88 4 * by Larry Wall and others
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5 *
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
8 *
9 */
10
11/*
4ac71550
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12 * 'What a fix!' said Sam. 'That's the one place in all the lands we've ever
13 * heard of that we don't want to see any closer; and that's the one place
14 * we're trying to get to! And that's just where we can't get, nohow.'
15 *
cdad3b53 16 * [p.603 of _The Lord of the Rings_, IV/I: "The Taming of Sméagol"]
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17 *
18 * 'Well do I understand your speech,' he answered in the same language;
19 * 'yet few strangers do so. Why then do you not speak in the Common Tongue,
4ac71550 20 * as is the custom in the West, if you wish to be answered?'
cdad3b53 21 * --Gandalf, addressing Théoden's door wardens
4ac71550
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22 *
23 * [p.508 of _The Lord of the Rings_, III/vi: "The King of the Golden Hall"]
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24 *
25 * ...the travellers perceived that the floor was paved with stones of many
26 * hues; branching runes and strange devices intertwined beneath their feet.
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27 *
28 * [p.512 of _The Lord of the Rings_, III/vi: "The King of the Golden Hall"]
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29 */
30
31#include "EXTERN.h"
864dbfa3 32#define PERL_IN_UTF8_C
a0ed51b3 33#include "perl.h"
b992490d 34#include "invlist_inline.h"
a0ed51b3 35
806547a7 36static const char malformed_text[] = "Malformed UTF-8 character";
27da23d5 37static const char unees[] =
806547a7 38 "Malformed UTF-8 character (unexpected end of string)";
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39
40/* Be sure to synchronize this message with the similar one in regcomp.c */
760c7c2f 41static const char cp_above_legal_max[] =
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42 "Use of code point 0x%" UVXf " is not allowed; the"
43 " permissible max is 0x%" UVXf;
760c7c2f 44
48ef279e 45/*
ccfc67b7 46=head1 Unicode Support
7fefc6c1 47These are various utility functions for manipulating UTF8-encoded
72d33970 48strings. For the uninitiated, this is a method of representing arbitrary
61296642 49Unicode characters as a variable number of bytes, in such a way that
56da48f7
DM
50characters in the ASCII range are unmodified, and a zero byte never appears
51within non-zero characters.
166f8a29 52
eaf7a4d2
CS
53=cut
54*/
55
dd051059
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56/* helper for Perl__force_out_malformed_utf8_message(). Like
57 * SAVECOMPILEWARNINGS(), but works with PL_curcop rather than
58 * PL_compiling */
59
60static void
61S_restore_cop_warnings(pTHX_ void *p)
62{
63 if (!specialWARN(PL_curcop->cop_warnings))
64 PerlMemShared_free(PL_curcop->cop_warnings);
65 PL_curcop->cop_warnings = (STRLEN*)p;
66}
67
68
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69void
70Perl__force_out_malformed_utf8_message(pTHX_
71 const U8 *const p, /* First byte in UTF-8 sequence */
72 const U8 * const e, /* Final byte in sequence (may include
73 multiple chars */
74 const U32 flags, /* Flags to pass to utf8n_to_uvchr(),
75 usually 0, or some DISALLOW flags */
76 const bool die_here) /* If TRUE, this function does not return */
77{
78 /* This core-only function is to be called when a malformed UTF-8 character
79 * is found, in order to output the detailed information about the
80 * malformation before dieing. The reason it exists is for the occasions
81 * when such a malformation is fatal, but warnings might be turned off, so
82 * that normally they would not be actually output. This ensures that they
83 * do get output. Because a sequence may be malformed in more than one
84 * way, multiple messages may be generated, so we can't make them fatal, as
85 * that would cause the first one to die.
86 *
87 * Instead we pretend -W was passed to perl, then die afterwards. The
88 * flexibility is here to return to the caller so they can finish up and
89 * die themselves */
90 U32 errors;
91
92 PERL_ARGS_ASSERT__FORCE_OUT_MALFORMED_UTF8_MESSAGE;
93
94 ENTER;
c15a80f3 95 SAVEI8(PL_dowarn);
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96 SAVESPTR(PL_curcop);
97
98 PL_dowarn = G_WARN_ALL_ON|G_WARN_ON;
99 if (PL_curcop) {
dd051059
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100 /* this is like SAVECOMPILEWARNINGS() except with PL_curcop rather
101 * than PL_compiling */
102 SAVEDESTRUCTOR_X(S_restore_cop_warnings,
103 (void*)PL_curcop->cop_warnings);
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104 PL_curcop->cop_warnings = pWARN_ALL;
105 }
106
107 (void) utf8n_to_uvchr_error(p, e - p, NULL, flags & ~UTF8_CHECK_ONLY, &errors);
108
109 LEAVE;
110
111 if (! errors) {
112 Perl_croak(aTHX_ "panic: _force_out_malformed_utf8_message should"
113 " be called only when there are errors found");
114 }
115
116 if (die_here) {
117 Perl_croak(aTHX_ "Malformed UTF-8 character (fatal)");
118 }
119}
120
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121STATIC HV *
122S_new_msg_hv(pTHX_ const char * const message, /* The message text */
123 U32 categories, /* Packed warning categories */
124 U32 flag) /* Flag associated with this message */
125{
126 /* Creates, populates, and returns an HV* that describes an error message
127 * for the translators between UTF8 and code point */
128
129 SV* msg_sv = newSVpv(message, 0);
130 SV* category_sv = newSVuv(categories);
131 SV* flag_bit_sv = newSVuv(flag);
132
133 HV* msg_hv = newHV();
134
135 PERL_ARGS_ASSERT_NEW_MSG_HV;
136
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137 (void) hv_stores(msg_hv, "text", msg_sv);
138 (void) hv_stores(msg_hv, "warn_categories", category_sv);
139 (void) hv_stores(msg_hv, "flag_bit", flag_bit_sv);
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140
141 return msg_hv;
142}
143
eaf7a4d2 144/*
378516de 145=for apidoc uvoffuni_to_utf8_flags
eebe1485 146
a27992cc 147THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES.
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148Instead, B<Almost all code should use L<perlapi/uvchr_to_utf8> or
149L<perlapi/uvchr_to_utf8_flags>>.
a27992cc 150
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151This function is like them, but the input is a strict Unicode
152(as opposed to native) code point. Only in very rare circumstances should code
153not be using the native code point.
949cf498 154
09232555 155For details, see the description for L<perlapi/uvchr_to_utf8_flags>.
949cf498 156
eebe1485
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157=cut
158*/
159
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160U8 *
161Perl_uvoffuni_to_utf8_flags(pTHX_ U8 *d, UV uv, const UV flags)
162{
163 PERL_ARGS_ASSERT_UVOFFUNI_TO_UTF8_FLAGS;
164
165 return uvoffuni_to_utf8_flags_msgs(d, uv, flags, NULL);
166}
167
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168/* All these formats take a single UV code point argument */
169const char surrogate_cp_format[] = "UTF-16 surrogate U+%04" UVXf;
170const char nonchar_cp_format[] = "Unicode non-character U+%04" UVXf
171 " is not recommended for open interchange";
172const char super_cp_format[] = "Code point 0x%" UVXf " is not Unicode,"
173 " may not be portable";
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174const char perl_extended_cp_format[] = "Code point 0x%" UVXf " is not" \
175 " Unicode, requires a Perl extension," \
176 " and so is not portable";
c94c2f39 177
33f38593 178#define HANDLE_UNICODE_SURROGATE(uv, flags, msgs) \
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179 STMT_START { \
180 if (flags & UNICODE_WARN_SURROGATE) { \
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181 U32 category = packWARN(WARN_SURROGATE); \
182 const char * format = surrogate_cp_format; \
183 if (msgs) { \
184 *msgs = new_msg_hv(Perl_form(aTHX_ format, uv), \
185 category, \
186 UNICODE_GOT_SURROGATE); \
187 } \
188 else { \
189 Perl_ck_warner_d(aTHX_ category, format, uv); \
190 } \
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191 } \
192 if (flags & UNICODE_DISALLOW_SURROGATE) { \
193 return NULL; \
194 } \
195 } STMT_END;
196
33f38593 197#define HANDLE_UNICODE_NONCHAR(uv, flags, msgs) \
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198 STMT_START { \
199 if (flags & UNICODE_WARN_NONCHAR) { \
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200 U32 category = packWARN(WARN_NONCHAR); \
201 const char * format = nonchar_cp_format; \
202 if (msgs) { \
203 *msgs = new_msg_hv(Perl_form(aTHX_ format, uv), \
204 category, \
205 UNICODE_GOT_NONCHAR); \
206 } \
207 else { \
208 Perl_ck_warner_d(aTHX_ category, format, uv); \
209 } \
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210 } \
211 if (flags & UNICODE_DISALLOW_NONCHAR) { \
212 return NULL; \
213 } \
214 } STMT_END;
215
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216/* Use shorter names internally in this file */
217#define SHIFT UTF_ACCUMULATION_SHIFT
218#undef MARK
219#define MARK UTF_CONTINUATION_MARK
220#define MASK UTF_CONTINUATION_MASK
221
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222/*
223=for apidoc uvchr_to_utf8_flags_msgs
224
225THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES.
226
227Most code should use C<L</uvchr_to_utf8_flags>()> rather than call this directly.
228
229This function is for code that wants any warning and/or error messages to be
230returned to the caller rather than be displayed. All messages that would have
884a31ee 231been displayed if all lexical warnings are enabled will be returned.
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232
233It is just like C<L</uvchr_to_utf8_flags>> but it takes an extra parameter
234placed after all the others, C<msgs>. If this parameter is 0, this function
235behaves identically to C<L</uvchr_to_utf8_flags>>. Otherwise, C<msgs> should
236be a pointer to an C<HV *> variable, in which this function creates a new HV to
237contain any appropriate messages. The hash has three key-value pairs, as
238follows:
239
240=over 4
241
242=item C<text>
243
244The text of the message as a C<SVpv>.
245
246=item C<warn_categories>
247
248The warning category (or categories) packed into a C<SVuv>.
249
250=item C<flag>
251
252A single flag bit associated with this message, in a C<SVuv>.
253The bit corresponds to some bit in the C<*errors> return value,
254such as C<UNICODE_GOT_SURROGATE>.
255
256=back
257
258It's important to note that specifying this parameter as non-null will cause
259any warnings this function would otherwise generate to be suppressed, and
260instead be placed in C<*msgs>. The caller can check the lexical warnings state
261(or not) when choosing what to do with the returned messages.
262
263The caller, of course, is responsible for freeing any returned HV.
264
265=cut
266*/
267
268/* Undocumented; we don't want people using this. Instead they should use
269 * uvchr_to_utf8_flags_msgs() */
dfe13c55 270U8 *
33f38593 271Perl_uvoffuni_to_utf8_flags_msgs(pTHX_ U8 *d, UV uv, const UV flags, HV** msgs)
a0ed51b3 272{
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273 PERL_ARGS_ASSERT_UVOFFUNI_TO_UTF8_FLAGS_MSGS;
274
275 if (msgs) {
276 *msgs = NULL;
277 }
7918f24d 278
2d1545e5 279 if (OFFUNI_IS_INVARIANT(uv)) {
4c8cd605 280 *d++ = LATIN1_TO_NATIVE(uv);
d9432125
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281 return d;
282 }
facc1dc2 283
3ea68d71 284 if (uv <= MAX_UTF8_TWO_BYTE) {
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285 *d++ = I8_TO_NATIVE_UTF8(( uv >> SHIFT) | UTF_START_MARK(2));
286 *d++ = I8_TO_NATIVE_UTF8(( uv & MASK) | MARK);
3ea68d71
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287 return d;
288 }
d9432125 289
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290 /* Not 2-byte; test for and handle 3-byte result. In the test immediately
291 * below, the 16 is for start bytes E0-EF (which are all the possible ones
292 * for 3 byte characters). The 2 is for 2 continuation bytes; these each
293 * contribute SHIFT bits. This yields 0x4000 on EBCDIC platforms, 0x1_0000
294 * on ASCII; so 3 bytes covers the range 0x400-0x3FFF on EBCDIC;
295 * 0x800-0xFFFF on ASCII */
296 if (uv < (16 * (1U << (2 * SHIFT)))) {
297 *d++ = I8_TO_NATIVE_UTF8(( uv >> ((3 - 1) * SHIFT)) | UTF_START_MARK(3));
298 *d++ = I8_TO_NATIVE_UTF8(((uv >> ((2 - 1) * SHIFT)) & MASK) | MARK);
299 *d++ = I8_TO_NATIVE_UTF8(( uv /* (1 - 1) */ & MASK) | MARK);
300
301#ifndef EBCDIC /* These problematic code points are 4 bytes on EBCDIC, so
302 aren't tested here */
303 /* The most likely code points in this range are below the surrogates.
304 * Do an extra test to quickly exclude those. */
305 if (UNLIKELY(uv >= UNICODE_SURROGATE_FIRST)) {
306 if (UNLIKELY( UNICODE_IS_32_CONTIGUOUS_NONCHARS(uv)
307 || UNICODE_IS_END_PLANE_NONCHAR_GIVEN_NOT_SUPER(uv)))
308 {
33f38593 309 HANDLE_UNICODE_NONCHAR(uv, flags, msgs);
8ee1cdcb
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310 }
311 else if (UNLIKELY(UNICODE_IS_SURROGATE(uv))) {
33f38593 312 HANDLE_UNICODE_SURROGATE(uv, flags, msgs);
760c7c2f 313 }
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314 }
315#endif
316 return d;
317 }
318
319 /* Not 3-byte; that means the code point is at least 0x1_0000 on ASCII
320 * platforms, and 0x4000 on EBCDIC. There are problematic cases that can
321 * happen starting with 4-byte characters on ASCII platforms. We unify the
322 * code for these with EBCDIC, even though some of them require 5-bytes on
323 * those, because khw believes the code saving is worth the very slight
324 * performance hit on these high EBCDIC code points. */
325
326 if (UNLIKELY(UNICODE_IS_SUPER(uv))) {
24b4c303
KW
327 if (UNLIKELY( uv > MAX_LEGAL_CP
328 && ! (flags & UNICODE_ALLOW_ABOVE_IV_MAX)))
329 {
40606899 330 Perl_croak(aTHX_ cp_above_legal_max, uv, MAX_LEGAL_CP);
a5bf80e0 331 }
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332 if ( (flags & UNICODE_WARN_SUPER)
333 || ( (flags & UNICODE_WARN_PERL_EXTENDED)
0a8a1a5b 334 && UNICODE_IS_PERL_EXTENDED(uv)))
a5bf80e0 335 {
33f38593
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336 const char * format = super_cp_format;
337 U32 category = packWARN(WARN_NON_UNICODE);
338 U32 flag = UNICODE_GOT_SUPER;
339
340 /* Choose the more dire applicable warning */
341 if (UNICODE_IS_PERL_EXTENDED(uv)) {
342 format = perl_extended_cp_format;
343 if (flags & (UNICODE_WARN_PERL_EXTENDED
344 |UNICODE_DISALLOW_PERL_EXTENDED))
345 {
346 flag = UNICODE_GOT_PERL_EXTENDED;
347 }
348 }
a5bf80e0 349
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350 if (msgs) {
351 *msgs = new_msg_hv(Perl_form(aTHX_ format, uv),
352 category, flag);
353 }
354 else {
355 Perl_ck_warner_d(aTHX_ packWARN(WARN_NON_UNICODE), format, uv);
356 }
a5bf80e0 357 }
56576a04 358 if ( (flags & UNICODE_DISALLOW_SUPER)
0a8a1a5b
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359 || ( (flags & UNICODE_DISALLOW_PERL_EXTENDED)
360 && UNICODE_IS_PERL_EXTENDED(uv)))
a5bf80e0
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361 {
362 return NULL;
363 }
364 }
ba6ed43c 365 else if (UNLIKELY(UNICODE_IS_END_PLANE_NONCHAR_GIVEN_NOT_SUPER(uv))) {
33f38593 366 HANDLE_UNICODE_NONCHAR(uv, flags, msgs);
507b9800 367 }
d9432125 368
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369 /* Test for and handle 4-byte result. In the test immediately below, the
370 * 8 is for start bytes F0-F7 (which are all the possible ones for 4 byte
371 * characters). The 3 is for 3 continuation bytes; these each contribute
372 * SHIFT bits. This yields 0x4_0000 on EBCDIC platforms, 0x20_0000 on
373 * ASCII, so 4 bytes covers the range 0x4000-0x3_FFFF on EBCDIC;
374 * 0x1_0000-0x1F_FFFF on ASCII */
375 if (uv < (8 * (1U << (3 * SHIFT)))) {
376 *d++ = I8_TO_NATIVE_UTF8(( uv >> ((4 - 1) * SHIFT)) | UTF_START_MARK(4));
377 *d++ = I8_TO_NATIVE_UTF8(((uv >> ((3 - 1) * SHIFT)) & MASK) | MARK);
378 *d++ = I8_TO_NATIVE_UTF8(((uv >> ((2 - 1) * SHIFT)) & MASK) | MARK);
379 *d++ = I8_TO_NATIVE_UTF8(( uv /* (1 - 1) */ & MASK) | MARK);
380
381#ifdef EBCDIC /* These were handled on ASCII platforms in the code for 3-byte
382 characters. The end-plane non-characters for EBCDIC were
383 handled just above */
384 if (UNLIKELY(UNICODE_IS_32_CONTIGUOUS_NONCHARS(uv))) {
33f38593 385 HANDLE_UNICODE_NONCHAR(uv, flags, msgs);
d528804a 386 }
ba6ed43c 387 else if (UNLIKELY(UNICODE_IS_SURROGATE(uv))) {
33f38593 388 HANDLE_UNICODE_SURROGATE(uv, flags, msgs);
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389 }
390#endif
391
392 return d;
393 }
394
395 /* Not 4-byte; that means the code point is at least 0x20_0000 on ASCII
396 * platforms, and 0x4000 on EBCDIC. At this point we switch to a loop
397 * format. The unrolled version above turns out to not save all that much
398 * time, and at these high code points (well above the legal Unicode range
399 * on ASCII platforms, and well above anything in common use in EBCDIC),
400 * khw believes that less code outweighs slight performance gains. */
401
d9432125 402 {
5aaebcb3 403 STRLEN len = OFFUNISKIP(uv);
1d72bdf6
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404 U8 *p = d+len-1;
405 while (p > d) {
957a9e81
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406 *p-- = I8_TO_NATIVE_UTF8((uv & MASK) | MARK);
407 uv >>= SHIFT;
1d72bdf6 408 }
4c8cd605 409 *p = I8_TO_NATIVE_UTF8((uv & UTF_START_MASK(len)) | UTF_START_MARK(len));
1d72bdf6
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410 return d+len;
411 }
a0ed51b3 412}
a5bf80e0 413
646ca15d 414/*
07693fe6
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415=for apidoc uvchr_to_utf8
416
bcb1a2d4 417Adds the UTF-8 representation of the native code point C<uv> to the end
f2fc1b45 418of the string C<d>; C<d> should have at least C<UVCHR_SKIP(uv)+1> (up to
c749c9fd
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419C<UTF8_MAXBYTES+1>) free bytes available. The return value is the pointer to
420the byte after the end of the new character. In other words,
07693fe6
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421
422 d = uvchr_to_utf8(d, uv);
423
424is the recommended wide native character-aware way of saying
425
426 *(d++) = uv;
427
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428This function accepts any code point from 0..C<IV_MAX> as input.
429C<IV_MAX> is typically 0x7FFF_FFFF in a 32-bit word.
760c7c2f
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430
431It is possible to forbid or warn on non-Unicode code points, or those that may
432be problematic by using L</uvchr_to_utf8_flags>.
de69f3af 433
07693fe6
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434=cut
435*/
436
de69f3af
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437/* This is also a macro */
438PERL_CALLCONV U8* Perl_uvchr_to_utf8(pTHX_ U8 *d, UV uv);
439
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440U8 *
441Perl_uvchr_to_utf8(pTHX_ U8 *d, UV uv)
442{
de69f3af 443 return uvchr_to_utf8(d, uv);
07693fe6
KW
444}
445
de69f3af
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446/*
447=for apidoc uvchr_to_utf8_flags
448
449Adds the UTF-8 representation of the native code point C<uv> to the end
f2fc1b45 450of the string C<d>; C<d> should have at least C<UVCHR_SKIP(uv)+1> (up to
c749c9fd
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451C<UTF8_MAXBYTES+1>) free bytes available. The return value is the pointer to
452the byte after the end of the new character. In other words,
de69f3af
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453
454 d = uvchr_to_utf8_flags(d, uv, flags);
455
456or, in most cases,
457
458 d = uvchr_to_utf8_flags(d, uv, 0);
459
460This is the Unicode-aware way of saying
461
462 *(d++) = uv;
463
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464If C<flags> is 0, this function accepts any code point from 0..C<IV_MAX> as
465input. C<IV_MAX> is typically 0x7FFF_FFFF in a 32-bit word.
760c7c2f
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466
467Specifying C<flags> can further restrict what is allowed and not warned on, as
468follows:
de69f3af 469
796b6530 470If C<uv> is a Unicode surrogate code point and C<UNICODE_WARN_SURROGATE> is set,
7ee537e6
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471the function will raise a warning, provided UTF8 warnings are enabled. If
472instead C<UNICODE_DISALLOW_SURROGATE> is set, the function will fail and return
473NULL. If both flags are set, the function will both warn and return NULL.
de69f3af 474
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475Similarly, the C<UNICODE_WARN_NONCHAR> and C<UNICODE_DISALLOW_NONCHAR> flags
476affect how the function handles a Unicode non-character.
93e6dbd6 477
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478And likewise, the C<UNICODE_WARN_SUPER> and C<UNICODE_DISALLOW_SUPER> flags
479affect the handling of code points that are above the Unicode maximum of
4800x10FFFF. Languages other than Perl may not be able to accept files that
481contain these.
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482
483The flag C<UNICODE_WARN_ILLEGAL_INTERCHANGE> selects all three of
484the above WARN flags; and C<UNICODE_DISALLOW_ILLEGAL_INTERCHANGE> selects all
ecc1615f
KW
485three DISALLOW flags. C<UNICODE_DISALLOW_ILLEGAL_INTERCHANGE> restricts the
486allowed inputs to the strict UTF-8 traditionally defined by Unicode.
487Similarly, C<UNICODE_WARN_ILLEGAL_C9_INTERCHANGE> and
488C<UNICODE_DISALLOW_ILLEGAL_C9_INTERCHANGE> are shortcuts to select the
489above-Unicode and surrogate flags, but not the non-character ones, as
490defined in
e2176993 491L<Unicode Corrigendum #9|https://www.unicode.org/versions/corrigendum9.html>.
ecc1615f 492See L<perlunicode/Noncharacter code points>.
93e6dbd6 493
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494Extremely high code points were never specified in any standard, and require an
495extension to UTF-8 to express, which Perl does. It is likely that programs
496written in something other than Perl would not be able to read files that
497contain these; nor would Perl understand files written by something that uses a
498different extension. For these reasons, there is a separate set of flags that
499can warn and/or disallow these extremely high code points, even if other
500above-Unicode ones are accepted. They are the C<UNICODE_WARN_PERL_EXTENDED>
501and C<UNICODE_DISALLOW_PERL_EXTENDED> flags. For more information see
502L</C<UTF8_GOT_PERL_EXTENDED>>. Of course C<UNICODE_DISALLOW_SUPER> will
503treat all above-Unicode code points, including these, as malformations. (Note
504that the Unicode standard considers anything above 0x10FFFF to be illegal, but
505there are standards predating it that allow up to 0x7FFF_FFFF (2**31 -1))
506
507A somewhat misleadingly named synonym for C<UNICODE_WARN_PERL_EXTENDED> is
508retained for backward compatibility: C<UNICODE_WARN_ABOVE_31_BIT>. Similarly,
509C<UNICODE_DISALLOW_ABOVE_31_BIT> is usable instead of the more accurately named
7c4a22ed
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510C<UNICODE_DISALLOW_PERL_EXTENDED>. The names are misleading because on EBCDIC
511platforms,these flags can apply to code points that actually do fit in 31 bits.
512The new names accurately describe the situation in all cases.
de69f3af 513
de69f3af
KW
514=cut
515*/
516
517/* This is also a macro */
518PERL_CALLCONV U8* Perl_uvchr_to_utf8_flags(pTHX_ U8 *d, UV uv, UV flags);
519
07693fe6
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520U8 *
521Perl_uvchr_to_utf8_flags(pTHX_ U8 *d, UV uv, UV flags)
522{
de69f3af 523 return uvchr_to_utf8_flags(d, uv, flags);
07693fe6
KW
524}
525
57ff5f59
KW
526#ifndef UV_IS_QUAD
527
e050c007
KW
528STATIC int
529S_is_utf8_cp_above_31_bits(const U8 * const s,
530 const U8 * const e,
531 const bool consider_overlongs)
83dc0f42
KW
532{
533 /* Returns TRUE if the first code point represented by the Perl-extended-
534 * UTF-8-encoded string starting at 's', and looking no further than 'e -
535 * 1' doesn't fit into 31 bytes. That is, that if it is >= 2**31.
536 *
537 * The function handles the case where the input bytes do not include all
538 * the ones necessary to represent a full character. That is, they may be
539 * the intial bytes of the representation of a code point, but possibly
540 * the final ones necessary for the complete representation may be beyond
541 * 'e - 1'.
542 *
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543 * The function also can handle the case where the input is an overlong
544 * sequence. If 'consider_overlongs' is 0, the function assumes the
545 * input is not overlong, without checking, and will return based on that
546 * assumption. If this parameter is 1, the function will go to the trouble
547 * of figuring out if it actually evaluates to above or below 31 bits.
83dc0f42 548 *
e050c007 549 * The sequence is otherwise assumed to be well-formed, without checking.
83dc0f42
KW
550 */
551
e050c007
KW
552 const STRLEN len = e - s;
553 int is_overlong;
554
555 PERL_ARGS_ASSERT_IS_UTF8_CP_ABOVE_31_BITS;
556
557 assert(! UTF8_IS_INVARIANT(*s) && e > s);
558
83dc0f42
KW
559#ifdef EBCDIC
560
e050c007 561 PERL_UNUSED_ARG(consider_overlongs);
83dc0f42 562
e050c007
KW
563 /* On the EBCDIC code pages we handle, only the native start byte 0xFE can
564 * mean a 32-bit or larger code point (0xFF is an invariant). 0xFE can
565 * also be the start byte for a 31-bit code point; we need at least 2
566 * bytes, and maybe up through 8 bytes, to determine that. (It can also be
567 * the start byte for an overlong sequence, but for 30-bit or smaller code
568 * points, so we don't have to worry about overlongs on EBCDIC.) */
569 if (*s != 0xFE) {
570 return 0;
571 }
83dc0f42 572
e050c007
KW
573 if (len == 1) {
574 return -1;
575 }
83dc0f42 576
e050c007 577#else
83dc0f42 578
e050c007
KW
579 /* On ASCII, FE and FF are the only start bytes that can evaluate to
580 * needing more than 31 bits. */
581 if (LIKELY(*s < 0xFE)) {
582 return 0;
583 }
83dc0f42 584
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KW
585 /* What we have left are FE and FF. Both of these require more than 31
586 * bits unless they are for overlongs. */
587 if (! consider_overlongs) {
588 return 1;
589 }
83dc0f42 590
e050c007
KW
591 /* Here, we have FE or FF. If the input isn't overlong, it evaluates to
592 * above 31 bits. But we need more than one byte to discern this, so if
593 * passed just the start byte, it could be an overlong evaluating to
594 * smaller */
595 if (len == 1) {
596 return -1;
597 }
83dc0f42 598
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KW
599 /* Having excluded len==1, and knowing that FE and FF are both valid start
600 * bytes, we can call the function below to see if the sequence is
601 * overlong. (We don't need the full generality of the called function,
602 * but for these huge code points, speed shouldn't be a consideration, and
603 * the compiler does have enough information, since it's static to this
604 * file, to optimize to just the needed parts.) */
605 is_overlong = is_utf8_overlong_given_start_byte_ok(s, len);
83dc0f42 606
e050c007
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607 /* If it isn't overlong, more than 31 bits are required. */
608 if (is_overlong == 0) {
609 return 1;
610 }
83dc0f42 611
e050c007
KW
612 /* If it is indeterminate if it is overlong, return that */
613 if (is_overlong < 0) {
614 return -1;
615 }
616
617 /* Here is overlong. Such a sequence starting with FE is below 31 bits, as
618 * the max it can be is 2**31 - 1 */
619 if (*s == 0xFE) {
620 return 0;
83dc0f42
KW
621 }
622
e050c007
KW
623#endif
624
625 /* Here, ASCII and EBCDIC rejoin:
626 * On ASCII: We have an overlong sequence starting with FF
627 * On EBCDIC: We have a sequence starting with FE. */
628
629 { /* For C89, use a block so the declaration can be close to its use */
630
631#ifdef EBCDIC
632
5f995336
KW
633 /* U+7FFFFFFF (2 ** 31 - 1)
634 * [0] [1] [2] [3] [4] [5] [6] [7] [8] [9] 10 11 12 13
635 * IBM-1047: \xFE\x41\x41\x41\x41\x41\x41\x42\x73\x73\x73\x73\x73\x73
636 * IBM-037: \xFE\x41\x41\x41\x41\x41\x41\x42\x72\x72\x72\x72\x72\x72
637 * POSIX-BC: \xFE\x41\x41\x41\x41\x41\x41\x42\x75\x75\x75\x75\x75\x75
638 * I8: \xFF\xA0\xA0\xA0\xA0\xA0\xA0\xA1\xBF\xBF\xBF\xBF\xBF\xBF
639 * U+80000000 (2 ** 31):
640 * IBM-1047: \xFE\x41\x41\x41\x41\x41\x41\x43\x41\x41\x41\x41\x41\x41
641 * IBM-037: \xFE\x41\x41\x41\x41\x41\x41\x43\x41\x41\x41\x41\x41\x41
642 * POSIX-BC: \xFE\x41\x41\x41\x41\x41\x41\x43\x41\x41\x41\x41\x41\x41
643 * I8: \xFF\xA0\xA0\xA0\xA0\xA0\xA0\xA2\xA0\xA0\xA0\xA0\xA0\xA0
e050c007
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644 *
645 * and since we know that *s = \xfe, any continuation sequcence
646 * following it that is gt the below is above 31 bits
647 [0] [1] [2] [3] [4] [5] [6] */
648 const U8 conts_for_highest_30_bit[] = "\x41\x41\x41\x41\x41\x41\x42";
649
650#else
651
652 /* FF overlong for U+7FFFFFFF (2 ** 31 - 1)
653 * ASCII: \xFF\x80\x80\x80\x80\x80\x80\x81\xBF\xBF\xBF\xBF\xBF
654 * FF overlong for U+80000000 (2 ** 31):
655 * ASCII: \xFF\x80\x80\x80\x80\x80\x80\x82\x80\x80\x80\x80\x80
656 * and since we know that *s = \xff, any continuation sequcence
657 * following it that is gt the below is above 30 bits
658 [0] [1] [2] [3] [4] [5] [6] */
659 const U8 conts_for_highest_30_bit[] = "\x80\x80\x80\x80\x80\x80\x81";
5f995336 660
83dc0f42
KW
661
662#endif
e050c007
KW
663 const STRLEN conts_len = sizeof(conts_for_highest_30_bit) - 1;
664 const STRLEN cmp_len = MIN(conts_len, len - 1);
665
666 /* Now compare the continuation bytes in s with the ones we have
667 * compiled in that are for the largest 30 bit code point. If we have
668 * enough bytes available to determine the answer, or the bytes we do
669 * have differ from them, we can compare the two to get a definitive
670 * answer (Note that in UTF-EBCDIC, the two lowest possible
671 * continuation bytes are \x41 and \x42.) */
672 if (cmp_len >= conts_len || memNE(s + 1,
673 conts_for_highest_30_bit,
674 cmp_len))
675 {
676 return cBOOL(memGT(s + 1, conts_for_highest_30_bit, cmp_len));
677 }
83dc0f42 678
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679 /* Here, all the bytes we have are the same as the highest 30-bit code
680 * point, but we are missing so many bytes that we can't make the
681 * determination */
682 return -1;
683 }
83dc0f42
KW
684}
685
57ff5f59
KW
686#endif
687
d6be65ae 688PERL_STATIC_INLINE int
12a4bed3
KW
689S_is_utf8_overlong_given_start_byte_ok(const U8 * const s, const STRLEN len)
690{
d6be65ae
KW
691 /* Returns an int indicating whether or not the UTF-8 sequence from 's' to
692 * 's' + 'len' - 1 is an overlong. It returns 1 if it is an overlong; 0 if
693 * it isn't, and -1 if there isn't enough information to tell. This last
694 * return value can happen if the sequence is incomplete, missing some
695 * trailing bytes that would form a complete character. If there are
696 * enough bytes to make a definitive decision, this function does so.
697 * Usually 2 bytes sufficient.
698 *
699 * Overlongs can occur whenever the number of continuation bytes changes.
700 * That means whenever the number of leading 1 bits in a start byte
701 * increases from the next lower start byte. That happens for start bytes
702 * C0, E0, F0, F8, FC, FE, and FF. On modern perls, the following illegal
703 * start bytes have already been excluded, so don't need to be tested here;
12a4bed3
KW
704 * ASCII platforms: C0, C1
705 * EBCDIC platforms C0, C1, C2, C3, C4, E0
d6be65ae 706 */
12a4bed3
KW
707
708 const U8 s0 = NATIVE_UTF8_TO_I8(s[0]);
709 const U8 s1 = NATIVE_UTF8_TO_I8(s[1]);
710
711 PERL_ARGS_ASSERT_IS_UTF8_OVERLONG_GIVEN_START_BYTE_OK;
712 assert(len > 1 && UTF8_IS_START(*s));
713
714 /* Each platform has overlongs after the start bytes given above (expressed
715 * in I8 for EBCDIC). What constitutes an overlong varies by platform, but
716 * the logic is the same, except the E0 overlong has already been excluded
717 * on EBCDIC platforms. The values below were found by manually
718 * inspecting the UTF-8 patterns. See the tables in utf8.h and
719 * utfebcdic.h. */
720
721# ifdef EBCDIC
722# define F0_ABOVE_OVERLONG 0xB0
723# define F8_ABOVE_OVERLONG 0xA8
724# define FC_ABOVE_OVERLONG 0xA4
725# define FE_ABOVE_OVERLONG 0xA2
726# define FF_OVERLONG_PREFIX "\xfe\x41\x41\x41\x41\x41\x41\x41"
727 /* I8(0xfe) is FF */
728# else
729
730 if (s0 == 0xE0 && UNLIKELY(s1 < 0xA0)) {
d6be65ae 731 return 1;
12a4bed3
KW
732 }
733
734# define F0_ABOVE_OVERLONG 0x90
735# define F8_ABOVE_OVERLONG 0x88
736# define FC_ABOVE_OVERLONG 0x84
737# define FE_ABOVE_OVERLONG 0x82
738# define FF_OVERLONG_PREFIX "\xff\x80\x80\x80\x80\x80\x80"
739# endif
740
741
742 if ( (s0 == 0xF0 && UNLIKELY(s1 < F0_ABOVE_OVERLONG))
743 || (s0 == 0xF8 && UNLIKELY(s1 < F8_ABOVE_OVERLONG))
744 || (s0 == 0xFC && UNLIKELY(s1 < FC_ABOVE_OVERLONG))
745 || (s0 == 0xFE && UNLIKELY(s1 < FE_ABOVE_OVERLONG)))
746 {
d6be65ae 747 return 1;
12a4bed3
KW
748 }
749
b0b342d4 750 /* Check for the FF overlong */
d6be65ae 751 return isFF_OVERLONG(s, len);
b0b342d4
KW
752}
753
8d6204cc 754PERL_STATIC_INLINE int
b0b342d4
KW
755S_isFF_OVERLONG(const U8 * const s, const STRLEN len)
756{
8d6204cc
KW
757 /* Returns an int indicating whether or not the UTF-8 sequence from 's' to
758 * 'e' - 1 is an overlong beginning with \xFF. It returns 1 if it is; 0 if
759 * it isn't, and -1 if there isn't enough information to tell. This last
760 * return value can happen if the sequence is incomplete, missing some
761 * trailing bytes that would form a complete character. If there are
762 * enough bytes to make a definitive decision, this function does so. */
763
b0b342d4 764 PERL_ARGS_ASSERT_ISFF_OVERLONG;
12a4bed3 765
8d6204cc
KW
766 /* To be an FF overlong, all the available bytes must match */
767 if (LIKELY(memNE(s, FF_OVERLONG_PREFIX,
768 MIN(len, sizeof(FF_OVERLONG_PREFIX) - 1))))
769 {
770 return 0;
771 }
772
773 /* To be an FF overlong sequence, all the bytes in FF_OVERLONG_PREFIX must
774 * be there; what comes after them doesn't matter. See tables in utf8.h,
b0b342d4 775 * utfebcdic.h. */
8d6204cc
KW
776 if (len >= sizeof(FF_OVERLONG_PREFIX) - 1) {
777 return 1;
778 }
12a4bed3 779
8d6204cc
KW
780 /* The missing bytes could cause the result to go one way or the other, so
781 * the result is indeterminate */
782 return -1;
12a4bed3
KW
783}
784
d22ec717 785#if defined(UV_IS_QUAD) /* These assume IV_MAX is 2**63-1 */
a77c906e
KW
786# ifdef EBCDIC /* Actually is I8 */
787# define HIGHEST_REPRESENTABLE_UTF8 \
d22ec717 788 "\xFF\xA7\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF"
a77c906e
KW
789# else
790# define HIGHEST_REPRESENTABLE_UTF8 \
d22ec717 791 "\xFF\x80\x87\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF"
a77c906e
KW
792# endif
793#endif
794
c285bbc4 795PERL_STATIC_INLINE int
e050c007
KW
796S_does_utf8_overflow(const U8 * const s,
797 const U8 * e,
798 const bool consider_overlongs)
a77c906e 799{
c285bbc4 800 /* Returns an int indicating whether or not the UTF-8 sequence from 's' to
d22ec717
KW
801 * 'e' - 1 would overflow an IV on this platform; that is if it represents
802 * a code point larger than the highest representable code point. It
803 * returns 1 if it does overflow; 0 if it doesn't, and -1 if there isn't
804 * enough information to tell. This last return value can happen if the
805 * sequence is incomplete, missing some trailing bytes that would form a
806 * complete character. If there are enough bytes to make a definitive
807 * decision, this function does so.
c285bbc4 808 *
e050c007
KW
809 * If 'consider_overlongs' is TRUE, the function checks for the possibility
810 * that the sequence is an overlong that doesn't overflow. Otherwise, it
811 * assumes the sequence is not an overlong. This can give different
812 * results only on ASCII 32-bit platforms.
813 *
c285bbc4
KW
814 * (For ASCII platforms, we could use memcmp() because we don't have to
815 * convert each byte to I8, but it's very rare input indeed that would
816 * approach overflow, so the loop below will likely only get executed once.)
817 *
818 * 'e' - 1 must not be beyond a full character. */
a77c906e 819
a77c906e
KW
820
821 PERL_ARGS_ASSERT_DOES_UTF8_OVERFLOW;
822 assert(s <= e && s + UTF8SKIP(s) >= e);
823
d22ec717
KW
824#if ! defined(UV_IS_QUAD)
825
826 return is_utf8_cp_above_31_bits(s, e, consider_overlongs);
827
828#else
829
830 PERL_UNUSED_ARG(consider_overlongs);
831
832 {
833 const STRLEN len = e - s;
834 const U8 *x;
835 const U8 * y = (const U8 *) HIGHEST_REPRESENTABLE_UTF8;
836
837 for (x = s; x < e; x++, y++) {
838
839 if (UNLIKELY(NATIVE_UTF8_TO_I8(*x) == *y)) {
840 continue;
841 }
842
843 /* If this byte is larger than the corresponding highest UTF-8
844 * byte, the sequence overflow; otherwise the byte is less than,
845 * and so the sequence doesn't overflow */
846 return NATIVE_UTF8_TO_I8(*x) > *y;
847
848 }
849
850 /* Got to the end and all bytes are the same. If the input is a whole
851 * character, it doesn't overflow. And if it is a partial character,
852 * there's not enough information to tell */
853 if (len < sizeof(HIGHEST_REPRESENTABLE_UTF8) - 1) {
854 return -1;
855 }
856
857 return 0;
858 }
859
860#endif
861
862}
863
864#if 0
865
866/* This is the portions of the above function that deal with UV_MAX instead of
867 * IV_MAX. They are left here in case we want to combine them so that internal
868 * uses can have larger code points. The only logic difference is that the
869 * 32-bit EBCDIC platform is treate like the 64-bit, and the 32-bit ASCII has
870 * different logic.
871 */
872
873/* Anything larger than this will overflow the word if it were converted into a UV */
874#if defined(UV_IS_QUAD)
875# ifdef EBCDIC /* Actually is I8 */
876# define HIGHEST_REPRESENTABLE_UTF8 \
877 "\xFF\xAF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF"
878# else
879# define HIGHEST_REPRESENTABLE_UTF8 \
880 "\xFF\x80\x8F\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF\xBF"
881# endif
882#else /* 32-bit */
883# ifdef EBCDIC
884# define HIGHEST_REPRESENTABLE_UTF8 \
885 "\xFF\xA0\xA0\xA0\xA0\xA0\xA0\xA3\xBF\xBF\xBF\xBF\xBF\xBF"
886# else
887# define HIGHEST_REPRESENTABLE_UTF8 "\xFE\x83\xBF\xBF\xBF\xBF\xBF"
888# endif
889#endif
890
a77c906e
KW
891#if ! defined(UV_IS_QUAD) && ! defined(EBCDIC)
892
893 /* On 32 bit ASCII machines, many overlongs that start with FF don't
894 * overflow */
e050c007 895 if (consider_overlongs && isFF_OVERLONG(s, len) > 0) {
c285bbc4
KW
896
897 /* To be such an overlong, the first bytes of 's' must match
898 * FF_OVERLONG_PREFIX, which is "\xff\x80\x80\x80\x80\x80\x80". If we
899 * don't have any additional bytes available, the sequence, when
900 * completed might or might not fit in 32 bits. But if we have that
901 * next byte, we can tell for sure. If it is <= 0x83, then it does
902 * fit. */
903 if (len <= sizeof(FF_OVERLONG_PREFIX) - 1) {
904 return -1;
905 }
906
907 return s[sizeof(FF_OVERLONG_PREFIX) - 1] > 0x83;
a77c906e
KW
908 }
909
d22ec717
KW
910/* Starting with the #else, the rest of the function is identical except
911 * 1. we need to move the 'len' declaration to be global to the function
912 * 2. the endif move to just after the UNUSED_ARG.
913 * An empty endif is given just below to satisfy the preprocessor
914 */
a77c906e
KW
915#endif
916
d22ec717 917#endif
a77c906e 918
12a4bed3
KW
919#undef F0_ABOVE_OVERLONG
920#undef F8_ABOVE_OVERLONG
921#undef FC_ABOVE_OVERLONG
922#undef FE_ABOVE_OVERLONG
923#undef FF_OVERLONG_PREFIX
924
35f8c9bd 925STRLEN
1376b35c 926Perl_is_utf8_char_helper(const U8 * const s, const U8 * e, const U32 flags)
35f8c9bd 927{
2b479609 928 STRLEN len;
12a4bed3 929 const U8 *x;
35f8c9bd 930
2b479609
KW
931 /* A helper function that should not be called directly.
932 *
933 * This function returns non-zero if the string beginning at 's' and
934 * looking no further than 'e - 1' is well-formed Perl-extended-UTF-8 for a
935 * code point; otherwise it returns 0. The examination stops after the
936 * first code point in 's' is validated, not looking at the rest of the
937 * input. If 'e' is such that there are not enough bytes to represent a
938 * complete code point, this function will return non-zero anyway, if the
939 * bytes it does have are well-formed UTF-8 as far as they go, and aren't
940 * excluded by 'flags'.
941 *
942 * A non-zero return gives the number of bytes required to represent the
943 * code point. Be aware that if the input is for a partial character, the
944 * return will be larger than 'e - s'.
945 *
946 * This function assumes that the code point represented is UTF-8 variant.
56576a04
KW
947 * The caller should have excluded the possibility of it being invariant
948 * before calling this function.
2b479609
KW
949 *
950 * 'flags' can be 0, or any combination of the UTF8_DISALLOW_foo flags
951 * accepted by L</utf8n_to_uvchr>. If non-zero, this function will return
952 * 0 if the code point represented is well-formed Perl-extended-UTF-8, but
953 * disallowed by the flags. If the input is only for a partial character,
954 * the function will return non-zero if there is any sequence of
955 * well-formed UTF-8 that, when appended to the input sequence, could
956 * result in an allowed code point; otherwise it returns 0. Non characters
957 * cannot be determined based on partial character input. But many of the
958 * other excluded types can be determined with just the first one or two
959 * bytes.
960 *
961 */
962
1376b35c 963 PERL_ARGS_ASSERT_IS_UTF8_CHAR_HELPER;
2b479609
KW
964
965 assert(0 == (flags & ~(UTF8_DISALLOW_ILLEGAL_INTERCHANGE
d044b7a7 966 |UTF8_DISALLOW_PERL_EXTENDED)));
2b479609 967 assert(! UTF8_IS_INVARIANT(*s));
35f8c9bd 968
2b479609 969 /* A variant char must begin with a start byte */
35f8c9bd
KW
970 if (UNLIKELY(! UTF8_IS_START(*s))) {
971 return 0;
972 }
973
edc2c47a
KW
974 /* Examine a maximum of a single whole code point */
975 if (e - s > UTF8SKIP(s)) {
976 e = s + UTF8SKIP(s);
977 }
978
2b479609
KW
979 len = e - s;
980
981 if (flags && isUTF8_POSSIBLY_PROBLEMATIC(*s)) {
982 const U8 s0 = NATIVE_UTF8_TO_I8(s[0]);
35f8c9bd 983
56576a04
KW
984 /* Here, we are disallowing some set of largish code points, and the
985 * first byte indicates the sequence is for a code point that could be
986 * in the excluded set. We generally don't have to look beyond this or
987 * the second byte to see if the sequence is actually for one of the
988 * excluded classes. The code below is derived from this table:
989 *
2b479609
KW
990 * UTF-8 UTF-EBCDIC I8
991 * U+D800: \xED\xA0\x80 \xF1\xB6\xA0\xA0 First surrogate
992 * U+DFFF: \xED\xBF\xBF \xF1\xB7\xBF\xBF Final surrogate
993 * U+110000: \xF4\x90\x80\x80 \xF9\xA2\xA0\xA0\xA0 First above Unicode
994 *
56576a04
KW
995 * Keep in mind that legal continuation bytes range between \x80..\xBF
996 * for UTF-8, and \xA0..\xBF for I8. Anything above those aren't
997 * continuation bytes. Hence, we don't have to test the upper edge
998 * because if any of those is encountered, the sequence is malformed,
999 * and would fail elsewhere in this function.
1000 *
1001 * The code here likewise assumes that there aren't other
1002 * malformations; again the function should fail elsewhere because of
1003 * these. For example, an overlong beginning with FC doesn't actually
1004 * have to be a super; it could actually represent a small code point,
1005 * even U+0000. But, since overlongs (and other malformations) are
1006 * illegal, the function should return FALSE in either case.
2b479609
KW
1007 */
1008
1009#ifdef EBCDIC /* On EBCDIC, these are actually I8 bytes */
1010# define FIRST_START_BYTE_THAT_IS_DEFINITELY_SUPER 0xFA
19794540 1011# define IS_UTF8_2_BYTE_SUPER(s0, s1) ((s0) == 0xF9 && (s1) >= 0xA2)
2b479609 1012
19794540
KW
1013# define IS_UTF8_2_BYTE_SURROGATE(s0, s1) ((s0) == 0xF1 \
1014 /* B6 and B7 */ \
1015 && ((s1) & 0xFE ) == 0xB6)
57ff5f59 1016# define isUTF8_PERL_EXTENDED(s) (*s == I8_TO_NATIVE_UTF8(0xFF))
2b479609
KW
1017#else
1018# define FIRST_START_BYTE_THAT_IS_DEFINITELY_SUPER 0xF5
19794540
KW
1019# define IS_UTF8_2_BYTE_SUPER(s0, s1) ((s0) == 0xF4 && (s1) >= 0x90)
1020# define IS_UTF8_2_BYTE_SURROGATE(s0, s1) ((s0) == 0xED && (s1) >= 0xA0)
57ff5f59 1021# define isUTF8_PERL_EXTENDED(s) (*s >= 0xFE)
2b479609
KW
1022#endif
1023
1024 if ( (flags & UTF8_DISALLOW_SUPER)
ddb65933
KW
1025 && UNLIKELY(s0 >= FIRST_START_BYTE_THAT_IS_DEFINITELY_SUPER))
1026 {
2b479609
KW
1027 return 0; /* Above Unicode */
1028 }
1029
d044b7a7 1030 if ( (flags & UTF8_DISALLOW_PERL_EXTENDED)
57ff5f59 1031 && UNLIKELY(isUTF8_PERL_EXTENDED(s)))
2b479609 1032 {
57ff5f59 1033 return 0;
2b479609
KW
1034 }
1035
1036 if (len > 1) {
1037 const U8 s1 = NATIVE_UTF8_TO_I8(s[1]);
1038
1039 if ( (flags & UTF8_DISALLOW_SUPER)
19794540 1040 && UNLIKELY(IS_UTF8_2_BYTE_SUPER(s0, s1)))
2b479609
KW
1041 {
1042 return 0; /* Above Unicode */
1043 }
1044
1045 if ( (flags & UTF8_DISALLOW_SURROGATE)
19794540 1046 && UNLIKELY(IS_UTF8_2_BYTE_SURROGATE(s0, s1)))
2b479609
KW
1047 {
1048 return 0; /* Surrogate */
1049 }
1050
1051 if ( (flags & UTF8_DISALLOW_NONCHAR)
1052 && UNLIKELY(UTF8_IS_NONCHAR(s, e)))
1053 {
1054 return 0; /* Noncharacter code point */
1055 }
1056 }
1057 }
1058
1059 /* Make sure that all that follows are continuation bytes */
35f8c9bd
KW
1060 for (x = s + 1; x < e; x++) {
1061 if (UNLIKELY(! UTF8_IS_CONTINUATION(*x))) {
1062 return 0;
1063 }
1064 }
1065
af13dd8a 1066 /* Here is syntactically valid. Next, make sure this isn't the start of an
12a4bed3 1067 * overlong. */
d6be65ae 1068 if (len > 1 && is_utf8_overlong_given_start_byte_ok(s, len) > 0) {
12a4bed3 1069 return 0;
af13dd8a
KW
1070 }
1071
12a4bed3
KW
1072 /* And finally, that the code point represented fits in a word on this
1073 * platform */
e050c007
KW
1074 if (0 < does_utf8_overflow(s, e,
1075 0 /* Don't consider overlongs */
1076 ))
1077 {
12a4bed3 1078 return 0;
35f8c9bd
KW
1079 }
1080
2b479609 1081 return UTF8SKIP(s);
35f8c9bd
KW
1082}
1083
7e2f38b2 1084char *
63ab03b3 1085Perl__byte_dump_string(pTHX_ const U8 * const start, const STRLEN len, const bool format)
7cf8d05d
KW
1086{
1087 /* Returns a mortalized C string that is a displayable copy of the 'len'
63ab03b3 1088 * bytes starting at 'start'. 'format' gives how to display each byte.
7e2f38b2
KW
1089 * Currently, there are only two formats, so it is currently a bool:
1090 * 0 \xab
1091 * 1 ab (that is a space between two hex digit bytes)
1092 */
7cf8d05d
KW
1093
1094 const STRLEN output_len = 4 * len + 1; /* 4 bytes per each input, plus a
1095 trailing NUL */
63ab03b3
KW
1096 const U8 * s = start;
1097 const U8 * const e = start + len;
7cf8d05d
KW
1098 char * output;
1099 char * d;
1100
1101 PERL_ARGS_ASSERT__BYTE_DUMP_STRING;
1102
1103 Newx(output, output_len, char);
1104 SAVEFREEPV(output);
1105
1106 d = output;
63ab03b3 1107 for (s = start; s < e; s++) {
7cf8d05d
KW
1108 const unsigned high_nibble = (*s & 0xF0) >> 4;
1109 const unsigned low_nibble = (*s & 0x0F);
1110
7e2f38b2 1111 if (format) {
63ab03b3
KW
1112 if (s > start) {
1113 *d++ = ' ';
1114 }
7e2f38b2
KW
1115 }
1116 else {
1117 *d++ = '\\';
1118 *d++ = 'x';
1119 }
7cf8d05d
KW
1120
1121 if (high_nibble < 10) {
1122 *d++ = high_nibble + '0';
1123 }
1124 else {
1125 *d++ = high_nibble - 10 + 'a';
1126 }
1127
1128 if (low_nibble < 10) {
1129 *d++ = low_nibble + '0';
1130 }
1131 else {
1132 *d++ = low_nibble - 10 + 'a';
1133 }
1134 }
1135
1136 *d = '\0';
1137 return output;
1138}
1139
806547a7 1140PERL_STATIC_INLINE char *
7cf8d05d
KW
1141S_unexpected_non_continuation_text(pTHX_ const U8 * const s,
1142
421da25c 1143 /* Max number of bytes to print */
3cc6a05e 1144 STRLEN print_len,
7cf8d05d
KW
1145
1146 /* Which one is the non-continuation */
1147 const STRLEN non_cont_byte_pos,
1148
1149 /* How many bytes should there be? */
1150 const STRLEN expect_len)
806547a7
KW
1151{
1152 /* Return the malformation warning text for an unexpected continuation
1153 * byte. */
1154
7cf8d05d 1155 const char * const where = (non_cont_byte_pos == 1)
806547a7 1156 ? "immediately"
7cf8d05d
KW
1157 : Perl_form(aTHX_ "%d bytes",
1158 (int) non_cont_byte_pos);
421da25c
KW
1159 const U8 * x = s + non_cont_byte_pos;
1160 const U8 * e = s + print_len;
806547a7
KW
1161
1162 PERL_ARGS_ASSERT_UNEXPECTED_NON_CONTINUATION_TEXT;
1163
7cf8d05d
KW
1164 /* We don't need to pass this parameter, but since it has already been
1165 * calculated, it's likely faster to pass it; verify under DEBUGGING */
1166 assert(expect_len == UTF8SKIP(s));
1167
421da25c
KW
1168 /* As a defensive coding measure, don't output anything past a NUL. Such
1169 * bytes shouldn't be in the middle of a malformation, and could mark the
1170 * end of the allocated string, and what comes after is undefined */
1171 for (; x < e; x++) {
1172 if (*x == '\0') {
1173 x++; /* Output this particular NUL */
1174 break;
1175 }
1176 }
1177
7cf8d05d
KW
1178 return Perl_form(aTHX_ "%s: %s (unexpected non-continuation byte 0x%02x,"
1179 " %s after start byte 0x%02x; need %d bytes, got %d)",
1180 malformed_text,
421da25c 1181 _byte_dump_string(s, x - s, 0),
7cf8d05d
KW
1182 *(s + non_cont_byte_pos),
1183 where,
1184 *s,
1185 (int) expect_len,
1186 (int) non_cont_byte_pos);
806547a7
KW
1187}
1188
35f8c9bd
KW
1189/*
1190
de69f3af 1191=for apidoc utf8n_to_uvchr
378516de
KW
1192
1193THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES.
09232555
KW
1194Most code should use L</utf8_to_uvchr_buf>() rather than call this
1195directly.
67e989fb 1196
9041c2e3 1197Bottom level UTF-8 decode routine.
de69f3af 1198Returns the native code point value of the first character in the string C<s>,
746afd53
KW
1199which is assumed to be in UTF-8 (or UTF-EBCDIC) encoding, and no longer than
1200C<curlen> bytes; C<*retlen> (if C<retlen> isn't NULL) will be set to
1201the length, in bytes, of that character.
949cf498
KW
1202
1203The value of C<flags> determines the behavior when C<s> does not point to a
2b5e7bc2
KW
1204well-formed UTF-8 character. If C<flags> is 0, encountering a malformation
1205causes zero to be returned and C<*retlen> is set so that (S<C<s> + C<*retlen>>)
1206is the next possible position in C<s> that could begin a non-malformed
1207character. Also, if UTF-8 warnings haven't been lexically disabled, a warning
1208is raised. Some UTF-8 input sequences may contain multiple malformations.
1209This function tries to find every possible one in each call, so multiple
56576a04 1210warnings can be raised for the same sequence.
949cf498
KW
1211
1212Various ALLOW flags can be set in C<flags> to allow (and not warn on)
1213individual types of malformations, such as the sequence being overlong (that
1214is, when there is a shorter sequence that can express the same code point;
1215overlong sequences are expressly forbidden in the UTF-8 standard due to
1216potential security issues). Another malformation example is the first byte of
1217a character not being a legal first byte. See F<utf8.h> for the list of such
94953955
KW
1218flags. Even if allowed, this function generally returns the Unicode
1219REPLACEMENT CHARACTER when it encounters a malformation. There are flags in
1220F<utf8.h> to override this behavior for the overlong malformations, but don't
1221do that except for very specialized purposes.
949cf498 1222
796b6530 1223The C<UTF8_CHECK_ONLY> flag overrides the behavior when a non-allowed (by other
949cf498
KW
1224flags) malformation is found. If this flag is set, the routine assumes that
1225the caller will raise a warning, and this function will silently just set
d088425d
KW
1226C<retlen> to C<-1> (cast to C<STRLEN>) and return zero.
1227
75200dff 1228Note that this API requires disambiguation between successful decoding a C<NUL>
796b6530 1229character, and an error return (unless the C<UTF8_CHECK_ONLY> flag is set), as
111fa700
KW
1230in both cases, 0 is returned, and, depending on the malformation, C<retlen> may
1231be set to 1. To disambiguate, upon a zero return, see if the first byte of
1232C<s> is 0 as well. If so, the input was a C<NUL>; if not, the input had an
f9380377 1233error. Or you can use C<L</utf8n_to_uvchr_error>>.
949cf498
KW
1234
1235Certain code points are considered problematic. These are Unicode surrogates,
746afd53 1236Unicode non-characters, and code points above the Unicode maximum of 0x10FFFF.
949cf498 1237By default these are considered regular code points, but certain situations
ecc1615f
KW
1238warrant special handling for them, which can be specified using the C<flags>
1239parameter. If C<flags> contains C<UTF8_DISALLOW_ILLEGAL_INTERCHANGE>, all
1240three classes are treated as malformations and handled as such. The flags
1241C<UTF8_DISALLOW_SURROGATE>, C<UTF8_DISALLOW_NONCHAR>, and
1242C<UTF8_DISALLOW_SUPER> (meaning above the legal Unicode maximum) can be set to
1243disallow these categories individually. C<UTF8_DISALLOW_ILLEGAL_INTERCHANGE>
1244restricts the allowed inputs to the strict UTF-8 traditionally defined by
1245Unicode. Use C<UTF8_DISALLOW_ILLEGAL_C9_INTERCHANGE> to use the strictness
1246definition given by
e2176993 1247L<Unicode Corrigendum #9|https://www.unicode.org/versions/corrigendum9.html>.
ecc1615f
KW
1248The difference between traditional strictness and C9 strictness is that the
1249latter does not forbid non-character code points. (They are still discouraged,
1250however.) For more discussion see L<perlunicode/Noncharacter code points>.
1251
1252The flags C<UTF8_WARN_ILLEGAL_INTERCHANGE>,
1253C<UTF8_WARN_ILLEGAL_C9_INTERCHANGE>, C<UTF8_WARN_SURROGATE>,
796b6530
KW
1254C<UTF8_WARN_NONCHAR>, and C<UTF8_WARN_SUPER> will cause warning messages to be
1255raised for their respective categories, but otherwise the code points are
1256considered valid (not malformations). To get a category to both be treated as
1257a malformation and raise a warning, specify both the WARN and DISALLOW flags.
949cf498 1258(But note that warnings are not raised if lexically disabled nor if
796b6530 1259C<UTF8_CHECK_ONLY> is also specified.)
949cf498 1260
57ff5f59
KW
1261Extremely high code points were never specified in any standard, and require an
1262extension to UTF-8 to express, which Perl does. It is likely that programs
1263written in something other than Perl would not be able to read files that
1264contain these; nor would Perl understand files written by something that uses a
1265different extension. For these reasons, there is a separate set of flags that
1266can warn and/or disallow these extremely high code points, even if other
1267above-Unicode ones are accepted. They are the C<UTF8_WARN_PERL_EXTENDED> and
1268C<UTF8_DISALLOW_PERL_EXTENDED> flags. For more information see
1269L</C<UTF8_GOT_PERL_EXTENDED>>. Of course C<UTF8_DISALLOW_SUPER> will treat all
1270above-Unicode code points, including these, as malformations.
1271(Note that the Unicode standard considers anything above 0x10FFFF to be
1272illegal, but there are standards predating it that allow up to 0x7FFF_FFFF
1273(2**31 -1))
1274
1275A somewhat misleadingly named synonym for C<UTF8_WARN_PERL_EXTENDED> is
1276retained for backward compatibility: C<UTF8_WARN_ABOVE_31_BIT>. Similarly,
1277C<UTF8_DISALLOW_ABOVE_31_BIT> is usable instead of the more accurately named
1278C<UTF8_DISALLOW_PERL_EXTENDED>. The names are misleading because these flags
1279can apply to code points that actually do fit in 31 bits. This happens on
1280EBCDIC platforms, and sometimes when the L<overlong
1281malformation|/C<UTF8_GOT_LONG>> is also present. The new names accurately
1282describe the situation in all cases.
1283
ab8e6d41 1284
949cf498
KW
1285All other code points corresponding to Unicode characters, including private
1286use and those yet to be assigned, are never considered malformed and never
1287warn.
67e989fb 1288
37607a96 1289=cut
f9380377
KW
1290
1291Also implemented as a macro in utf8.h
1292*/
1293
1294UV
e6a4ffc3
KW
1295Perl_utf8n_to_uvchr(const U8 *s,
1296 STRLEN curlen,
1297 STRLEN *retlen,
1298 const U32 flags)
f9380377
KW
1299{
1300 PERL_ARGS_ASSERT_UTF8N_TO_UVCHR;
1301
1302 return utf8n_to_uvchr_error(s, curlen, retlen, flags, NULL);
1303}
1304
1305/*
1306
1307=for apidoc utf8n_to_uvchr_error
1308
1309THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES.
09232555
KW
1310Most code should use L</utf8_to_uvchr_buf>() rather than call this
1311directly.
f9380377
KW
1312
1313This function is for code that needs to know what the precise malformation(s)
37657a5b
KW
1314are when an error is found. If you also need to know the generated warning
1315messages, use L</utf8n_to_uvchr_msgs>() instead.
f9380377
KW
1316
1317It is like C<L</utf8n_to_uvchr>> but it takes an extra parameter placed after
1318all the others, C<errors>. If this parameter is 0, this function behaves
1319identically to C<L</utf8n_to_uvchr>>. Otherwise, C<errors> should be a pointer
1320to a C<U32> variable, which this function sets to indicate any errors found.
1321Upon return, if C<*errors> is 0, there were no errors found. Otherwise,
1322C<*errors> is the bit-wise C<OR> of the bits described in the list below. Some
1323of these bits will be set if a malformation is found, even if the input
7a65503b 1324C<flags> parameter indicates that the given malformation is allowed; those
f9380377
KW
1325exceptions are noted:
1326
1327=over 4
1328
57ff5f59 1329=item C<UTF8_GOT_PERL_EXTENDED>
f9380377 1330
57ff5f59
KW
1331The input sequence is not standard UTF-8, but a Perl extension. This bit is
1332set only if the input C<flags> parameter contains either the
1333C<UTF8_DISALLOW_PERL_EXTENDED> or the C<UTF8_WARN_PERL_EXTENDED> flags.
1334
1335Code points above 0x7FFF_FFFF (2**31 - 1) were never specified in any standard,
1336and so some extension must be used to express them. Perl uses a natural
1337extension to UTF-8 to represent the ones up to 2**36-1, and invented a further
1338extension to represent even higher ones, so that any code point that fits in a
133964-bit word can be represented. Text using these extensions is not likely to
1340be portable to non-Perl code. We lump both of these extensions together and
1341refer to them as Perl extended UTF-8. There exist other extensions that people
1342have invented, incompatible with Perl's.
1343
1344On EBCDIC platforms starting in Perl v5.24, the Perl extension for representing
1345extremely high code points kicks in at 0x3FFF_FFFF (2**30 -1), which is lower
1346than on ASCII. Prior to that, code points 2**31 and higher were simply
1347unrepresentable, and a different, incompatible method was used to represent
1348code points between 2**30 and 2**31 - 1.
1349
1350On both platforms, ASCII and EBCDIC, C<UTF8_GOT_PERL_EXTENDED> is set if
1351Perl extended UTF-8 is used.
1352
1353In earlier Perls, this bit was named C<UTF8_GOT_ABOVE_31_BIT>, which you still
1354may use for backward compatibility. That name is misleading, as this flag may
1355be set when the code point actually does fit in 31 bits. This happens on
1356EBCDIC platforms, and sometimes when the L<overlong
1357malformation|/C<UTF8_GOT_LONG>> is also present. The new name accurately
1358describes the situation in all cases.
f9380377
KW
1359
1360=item C<UTF8_GOT_CONTINUATION>
1361
1362The input sequence was malformed in that the first byte was a a UTF-8
1363continuation byte.
1364
1365=item C<UTF8_GOT_EMPTY>
1366
1367The input C<curlen> parameter was 0.
1368
1369=item C<UTF8_GOT_LONG>
1370
1371The input sequence was malformed in that there is some other sequence that
1372evaluates to the same code point, but that sequence is shorter than this one.
1373
fecaf136
KW
1374Until Unicode 3.1, it was legal for programs to accept this malformation, but
1375it was discovered that this created security issues.
1376
f9380377
KW
1377=item C<UTF8_GOT_NONCHAR>
1378
1379The code point represented by the input UTF-8 sequence is for a Unicode
1380non-character code point.
1381This bit is set only if the input C<flags> parameter contains either the
1382C<UTF8_DISALLOW_NONCHAR> or the C<UTF8_WARN_NONCHAR> flags.
1383
1384=item C<UTF8_GOT_NON_CONTINUATION>
1385
1386The input sequence was malformed in that a non-continuation type byte was found
00d976bb
KW
1387in a position where only a continuation type one should be. See also
1388L</C<UTF8_GOT_SHORT>>.
f9380377
KW
1389
1390=item C<UTF8_GOT_OVERFLOW>
1391
1392The input sequence was malformed in that it is for a code point that is not
d22ec717 1393representable in the number of bits available in an IV on the current platform.
f9380377
KW
1394
1395=item C<UTF8_GOT_SHORT>
1396
1397The input sequence was malformed in that C<curlen> is smaller than required for
1398a complete sequence. In other words, the input is for a partial character
1399sequence.
1400
00d976bb
KW
1401
1402C<UTF8_GOT_SHORT> and C<UTF8_GOT_NON_CONTINUATION> both indicate a too short
1403sequence. The difference is that C<UTF8_GOT_NON_CONTINUATION> indicates always
1404that there is an error, while C<UTF8_GOT_SHORT> means that an incomplete
1405sequence was looked at. If no other flags are present, it means that the
1406sequence was valid as far as it went. Depending on the application, this could
1407mean one of three things:
1408
1409=over
1410
1411=item *
1412
1413The C<curlen> length parameter passed in was too small, and the function was
1414prevented from examining all the necessary bytes.
1415
1416=item *
1417
1418The buffer being looked at is based on reading data, and the data received so
1419far stopped in the middle of a character, so that the next read will
1420read the remainder of this character. (It is up to the caller to deal with the
1421split bytes somehow.)
1422
1423=item *
1424
1425This is a real error, and the partial sequence is all we're going to get.
1426
1427=back
1428
f9380377
KW
1429=item C<UTF8_GOT_SUPER>
1430
1431The input sequence was malformed in that it is for a non-Unicode code point;
1432that is, one above the legal Unicode maximum.
1433This bit is set only if the input C<flags> parameter contains either the
1434C<UTF8_DISALLOW_SUPER> or the C<UTF8_WARN_SUPER> flags.
1435
1436=item C<UTF8_GOT_SURROGATE>
1437
1438The input sequence was malformed in that it is for a -Unicode UTF-16 surrogate
1439code point.
1440This bit is set only if the input C<flags> parameter contains either the
1441C<UTF8_DISALLOW_SURROGATE> or the C<UTF8_WARN_SURROGATE> flags.
1442
1443=back
1444
133551d8
KW
1445To do your own error handling, call this function with the C<UTF8_CHECK_ONLY>
1446flag to suppress any warnings, and then examine the C<*errors> return.
1447
f9380377 1448=cut
37657a5b
KW
1449
1450Also implemented as a macro in utf8.h
37607a96 1451*/
67e989fb 1452
a0ed51b3 1453UV
e6a4ffc3 1454Perl_utf8n_to_uvchr_error(const U8 *s,
37657a5b
KW
1455 STRLEN curlen,
1456 STRLEN *retlen,
1457 const U32 flags,
1458 U32 * errors)
1459{
1460 PERL_ARGS_ASSERT_UTF8N_TO_UVCHR_ERROR;
1461
1462 return utf8n_to_uvchr_msgs(s, curlen, retlen, flags, errors, NULL);
1463}
1464
1465/*
1466
1467=for apidoc utf8n_to_uvchr_msgs
1468
1469THIS FUNCTION SHOULD BE USED IN ONLY VERY SPECIALIZED CIRCUMSTANCES.
09232555
KW
1470Most code should use L</utf8_to_uvchr_buf>() rather than call this
1471directly.
37657a5b
KW
1472
1473This function is for code that needs to know what the precise malformation(s)
1474are when an error is found, and wants the corresponding warning and/or error
1475messages to be returned to the caller rather than be displayed. All messages
1476that would have been displayed if all lexcial warnings are enabled will be
1477returned.
1478
1479It is just like C<L</utf8n_to_uvchr_error>> but it takes an extra parameter
1480placed after all the others, C<msgs>. If this parameter is 0, this function
1481behaves identically to C<L</utf8n_to_uvchr_error>>. Otherwise, C<msgs> should
1482be a pointer to an C<AV *> variable, in which this function creates a new AV to
1483contain any appropriate messages. The elements of the array are ordered so
1484that the first message that would have been displayed is in the 0th element,
1485and so on. Each element is a hash with three key-value pairs, as follows:
1486
1487=over 4
1488
1489=item C<text>
1490
1491The text of the message as a C<SVpv>.
1492
1493=item C<warn_categories>
1494
1495The warning category (or categories) packed into a C<SVuv>.
1496
1497=item C<flag>
1498
1499A single flag bit associated with this message, in a C<SVuv>.
1500The bit corresponds to some bit in the C<*errors> return value,
1501such as C<UTF8_GOT_LONG>.
1502
1503=back
1504
1505It's important to note that specifying this parameter as non-null will cause
1506any warnings this function would otherwise generate to be suppressed, and
1507instead be placed in C<*msgs>. The caller can check the lexical warnings state
1508(or not) when choosing what to do with the returned messages.
1509
1510If the flag C<UTF8_CHECK_ONLY> is passed, no warnings are generated, and hence
1511no AV is created.
1512
1513The caller, of course, is responsible for freeing any returned AV.
1514
1515=cut
1516*/
1517
1518UV
e6a4ffc3 1519Perl__utf8n_to_uvchr_msgs_helper(const U8 *s,
37657a5b
KW
1520 STRLEN curlen,
1521 STRLEN *retlen,
1522 const U32 flags,
1523 U32 * errors,
1524 AV ** msgs)
a0ed51b3 1525{
d4c19fe8 1526 const U8 * const s0 = s;
2b9519f0 1527 const U8 * send = s0 + curlen;
5af9f822
KW
1528 U32 possible_problems; /* A bit is set here for each potential problem
1529 found as we go along */
1530 UV uv;
1531 STRLEN expectlen; /* How long should this sequence be? */
1532 STRLEN avail_len; /* When input is too short, gives what that is */
1533 U32 discard_errors; /* Used to save branches when 'errors' is NULL; this
1534 gets set and discarded */
a0dbb045 1535
2b5e7bc2
KW
1536 /* The below are used only if there is both an overlong malformation and a
1537 * too short one. Otherwise the first two are set to 's0' and 'send', and
1538 * the third not used at all */
5af9f822 1539 U8 * adjusted_s0;
e9f2c446
KW
1540 U8 temp_char_buf[UTF8_MAXBYTES + 1]; /* Used to avoid a Newx in this
1541 routine; see [perl #130921] */
5af9f822 1542 UV uv_so_far;
e6a4ffc3 1543 dTHX;
5af9f822 1544
e6a4ffc3 1545 PERL_ARGS_ASSERT__UTF8N_TO_UVCHR_MSGS_HELPER;
5af9f822
KW
1546
1547 /* Here, is one of: a) malformed; b) a problematic code point (surrogate,
1548 * non-unicode, or nonchar); or c) on ASCII platforms, one of the Hangul
1549 * syllables that the dfa doesn't properly handle. Quickly dispose of the
1550 * final case. */
1551
1552#ifndef EBCDIC
1553
1554 /* Each of the affected Hanguls starts with \xED */
1555
1556 if (is_HANGUL_ED_utf8_safe(s0, send)) {
1557 if (retlen) {
1558 *retlen = 3;
1559 }
1560 if (errors) {
1561 *errors = 0;
1562 }
1563 if (msgs) {
1564 *msgs = NULL;
1565 }
1566
1567 return ((0xED & UTF_START_MASK(3)) << (2 * UTF_ACCUMULATION_SHIFT))
1568 | ((s0[1] & UTF_CONTINUATION_MASK) << UTF_ACCUMULATION_SHIFT)
1569 | (s0[2] & UTF_CONTINUATION_MASK);
1570 }
1571
1572#endif
1573
1574 /* In conjunction with the exhaustive tests that can be enabled in
1575 * APItest/t/utf8_warn_base.pl, this can make sure the dfa does precisely
1576 * what it is intended to do, and that no flaws in it are masked by
1577 * dropping down and executing the code below
1578 assert(! isUTF8_CHAR(s0, send)
1579 || UTF8_IS_SURROGATE(s0, send)
1580 || UTF8_IS_SUPER(s0, send)
1581 || UTF8_IS_NONCHAR(s0,send));
1582 */
1583
1584 s = s0;
1585 uv = *s0;
1586 possible_problems = 0;
1587 expectlen = 0;
1588 avail_len = 0;
1589 discard_errors = 0;
1590 adjusted_s0 = (U8 *) s0;
1591 uv_so_far = 0;
1592
f9380377
KW
1593 if (errors) {
1594 *errors = 0;
1595 }
1596 else {
1597 errors = &discard_errors;
1598 }
a0dbb045 1599
eb83ed87
KW
1600 /* The order of malformation tests here is important. We should consume as
1601 * few bytes as possible in order to not skip any valid character. This is
1602 * required by the Unicode Standard (section 3.9 of Unicode 6.0); see also
e2176993 1603 * https://unicode.org/reports/tr36 for more discussion as to why. For
eb83ed87
KW
1604 * example, once we've done a UTF8SKIP, we can tell the expected number of
1605 * bytes, and could fail right off the bat if the input parameters indicate
1606 * that there are too few available. But it could be that just that first
1607 * byte is garbled, and the intended character occupies fewer bytes. If we
1608 * blindly assumed that the first byte is correct, and skipped based on
1609 * that number, we could skip over a valid input character. So instead, we
1610 * always examine the sequence byte-by-byte.
1611 *
1612 * We also should not consume too few bytes, otherwise someone could inject
1613 * things. For example, an input could be deliberately designed to
1614 * overflow, and if this code bailed out immediately upon discovering that,
e2660c54 1615 * returning to the caller C<*retlen> pointing to the very next byte (one
eb83ed87
KW
1616 * which is actually part of of the overflowing sequence), that could look
1617 * legitimate to the caller, which could discard the initial partial
2b5e7bc2
KW
1618 * sequence and process the rest, inappropriately.
1619 *
1620 * Some possible input sequences are malformed in more than one way. This
1621 * function goes to lengths to try to find all of them. This is necessary
1622 * for correctness, as the inputs may allow one malformation but not
1623 * another, and if we abandon searching for others after finding the
1624 * allowed one, we could allow in something that shouldn't have been.
1625 */
eb83ed87 1626
b5b9af04 1627 if (UNLIKELY(curlen == 0)) {
2b5e7bc2
KW
1628 possible_problems |= UTF8_GOT_EMPTY;
1629 curlen = 0;
5a48568d 1630 uv = UNICODE_REPLACEMENT;
2b5e7bc2 1631 goto ready_to_handle_errors;
0c443dc2
JH
1632 }
1633
eb83ed87
KW
1634 expectlen = UTF8SKIP(s);
1635
1636 /* A well-formed UTF-8 character, as the vast majority of calls to this
1637 * function will be for, has this expected length. For efficiency, set
1638 * things up here to return it. It will be overriden only in those rare
1639 * cases where a malformation is found */
1640 if (retlen) {
1641 *retlen = expectlen;
1642 }
1643
eb83ed87 1644 /* A continuation character can't start a valid sequence */
b5b9af04 1645 if (UNLIKELY(UTF8_IS_CONTINUATION(uv))) {
2b5e7bc2
KW
1646 possible_problems |= UTF8_GOT_CONTINUATION;
1647 curlen = 1;
1648 uv = UNICODE_REPLACEMENT;
1649 goto ready_to_handle_errors;
ba210ebe 1650 }
9041c2e3 1651
dcd27b3c 1652 /* Here is not a continuation byte, nor an invariant. The only thing left
ddb65933
KW
1653 * is a start byte (possibly for an overlong). (We can't use UTF8_IS_START
1654 * because it excludes start bytes like \xC0 that always lead to
1655 * overlongs.) */
dcd27b3c 1656
534752c1
KW
1657 /* Convert to I8 on EBCDIC (no-op on ASCII), then remove the leading bits
1658 * that indicate the number of bytes in the character's whole UTF-8
1659 * sequence, leaving just the bits that are part of the value. */
1660 uv = NATIVE_UTF8_TO_I8(uv) & UTF_START_MASK(expectlen);
ba210ebe 1661
e308b348
KW
1662 /* Setup the loop end point, making sure to not look past the end of the
1663 * input string, and flag it as too short if the size isn't big enough. */
e308b348
KW
1664 if (UNLIKELY(curlen < expectlen)) {
1665 possible_problems |= UTF8_GOT_SHORT;
1666 avail_len = curlen;
e308b348
KW
1667 }
1668 else {
2b9519f0 1669 send = (U8*) s0 + expectlen;
e308b348 1670 }
e308b348 1671
eb83ed87 1672 /* Now, loop through the remaining bytes in the character's sequence,
e308b348 1673 * accumulating each into the working value as we go. */
eb83ed87 1674 for (s = s0 + 1; s < send; s++) {
b5b9af04 1675 if (LIKELY(UTF8_IS_CONTINUATION(*s))) {
8850bf83 1676 uv = UTF8_ACCUMULATE(uv, *s);
2b5e7bc2
KW
1677 continue;
1678 }
1679
1680 /* Here, found a non-continuation before processing all expected bytes.
1681 * This byte indicates the beginning of a new character, so quit, even
1682 * if allowing this malformation. */
2b5e7bc2 1683 possible_problems |= UTF8_GOT_NON_CONTINUATION;
e308b348 1684 break;
eb83ed87
KW
1685 } /* End of loop through the character's bytes */
1686
1687 /* Save how many bytes were actually in the character */
1688 curlen = s - s0;
1689
2b5e7bc2
KW
1690 /* Note that there are two types of too-short malformation. One is when
1691 * there is actual wrong data before the normal termination of the
1692 * sequence. The other is that the sequence wasn't complete before the end
1693 * of the data we are allowed to look at, based on the input 'curlen'.
1694 * This means that we were passed data for a partial character, but it is
1695 * valid as far as we saw. The other is definitely invalid. This
1696 * distinction could be important to a caller, so the two types are kept
15b010f0
KW
1697 * separate.
1698 *
1699 * A convenience macro that matches either of the too-short conditions. */
1700# define UTF8_GOT_TOO_SHORT (UTF8_GOT_SHORT|UTF8_GOT_NON_CONTINUATION)
1701
1702 if (UNLIKELY(possible_problems & UTF8_GOT_TOO_SHORT)) {
1703 uv_so_far = uv;
1704 uv = UNICODE_REPLACEMENT;
1705 }
2b5e7bc2 1706
08e73697
KW
1707 /* Check for overflow. The algorithm requires us to not look past the end
1708 * of the current character, even if partial, so the upper limit is 's' */
e050c007
KW
1709 if (UNLIKELY(0 < does_utf8_overflow(s0, s,
1710 1 /* Do consider overlongs */
1711 )))
1712 {
2b5e7bc2
KW
1713 possible_problems |= UTF8_GOT_OVERFLOW;
1714 uv = UNICODE_REPLACEMENT;
eb83ed87 1715 }
eb83ed87 1716
2b5e7bc2
KW
1717 /* Check for overlong. If no problems so far, 'uv' is the correct code
1718 * point value. Simply see if it is expressible in fewer bytes. Otherwise
1719 * we must look at the UTF-8 byte sequence itself to see if it is for an
1720 * overlong */
1721 if ( ( LIKELY(! possible_problems)
1722 && UNLIKELY(expectlen > (STRLEN) OFFUNISKIP(uv)))
56576a04 1723 || ( UNLIKELY(possible_problems)
2b5e7bc2
KW
1724 && ( UNLIKELY(! UTF8_IS_START(*s0))
1725 || ( curlen > 1
d6be65ae 1726 && UNLIKELY(0 < is_utf8_overlong_given_start_byte_ok(s0,
08e73697 1727 s - s0))))))
2f8f112e 1728 {
2b5e7bc2
KW
1729 possible_problems |= UTF8_GOT_LONG;
1730
abc28b54 1731 if ( UNLIKELY( possible_problems & UTF8_GOT_TOO_SHORT)
56576a04 1732
abc28b54
KW
1733 /* The calculation in the 'true' branch of this 'if'
1734 * below won't work if overflows, and isn't needed
1735 * anyway. Further below we handle all overflow
1736 * cases */
1737 && LIKELY(! (possible_problems & UTF8_GOT_OVERFLOW)))
1738 {
2b5e7bc2
KW
1739 UV min_uv = uv_so_far;
1740 STRLEN i;
1741
1742 /* Here, the input is both overlong and is missing some trailing
1743 * bytes. There is no single code point it could be for, but there
1744 * may be enough information present to determine if what we have
1745 * so far is for an unallowed code point, such as for a surrogate.
56576a04
KW
1746 * The code further below has the intelligence to determine this,
1747 * but just for non-overlong UTF-8 sequences. What we do here is
1748 * calculate the smallest code point the input could represent if
1749 * there were no too short malformation. Then we compute and save
1750 * the UTF-8 for that, which is what the code below looks at
1751 * instead of the raw input. It turns out that the smallest such
1752 * code point is all we need. */
2b5e7bc2
KW
1753 for (i = curlen; i < expectlen; i++) {
1754 min_uv = UTF8_ACCUMULATE(min_uv,
1755 I8_TO_NATIVE_UTF8(UTF_CONTINUATION_MARK));
1756 }
1757
e9f2c446 1758 adjusted_s0 = temp_char_buf;
57ff5f59 1759 (void) uvoffuni_to_utf8_flags(adjusted_s0, min_uv, 0);
2b5e7bc2 1760 }
eb83ed87
KW
1761 }
1762
56576a04
KW
1763 /* Here, we have found all the possible problems, except for when the input
1764 * is for a problematic code point not allowed by the input parameters. */
1765
06188866
KW
1766 /* uv is valid for overlongs */
1767 if ( ( ( LIKELY(! (possible_problems & ~UTF8_GOT_LONG))
1768
1769 /* isn't problematic if < this */
1770 && uv >= UNICODE_SURROGATE_FIRST)
2b5e7bc2 1771 || ( UNLIKELY(possible_problems)
d60baaa7
KW
1772
1773 /* if overflow, we know without looking further
1774 * precisely which of the problematic types it is,
1775 * and we deal with those in the overflow handling
1776 * code */
1777 && LIKELY(! (possible_problems & UTF8_GOT_OVERFLOW))
57ff5f59
KW
1778 && ( isUTF8_POSSIBLY_PROBLEMATIC(*adjusted_s0)
1779 || UNLIKELY(isUTF8_PERL_EXTENDED(s0)))))
760c7c2f
KW
1780 && ((flags & ( UTF8_DISALLOW_NONCHAR
1781 |UTF8_DISALLOW_SURROGATE
1782 |UTF8_DISALLOW_SUPER
d044b7a7 1783 |UTF8_DISALLOW_PERL_EXTENDED
760c7c2f
KW
1784 |UTF8_WARN_NONCHAR
1785 |UTF8_WARN_SURROGATE
1786 |UTF8_WARN_SUPER
d22ec717 1787 |UTF8_WARN_PERL_EXTENDED))))
eb83ed87 1788 {
2b5e7bc2
KW
1789 /* If there were no malformations, or the only malformation is an
1790 * overlong, 'uv' is valid */
1791 if (LIKELY(! (possible_problems & ~UTF8_GOT_LONG))) {
1792 if (UNLIKELY(UNICODE_IS_SURROGATE(uv))) {
1793 possible_problems |= UTF8_GOT_SURROGATE;
1794 }
1795 else if (UNLIKELY(uv > PERL_UNICODE_MAX)) {
1796 possible_problems |= UTF8_GOT_SUPER;
1797 }
1798 else if (UNLIKELY(UNICODE_IS_NONCHAR(uv))) {
1799 possible_problems |= UTF8_GOT_NONCHAR;
1800 }
1801 }
1802 else { /* Otherwise, need to look at the source UTF-8, possibly
1803 adjusted to be non-overlong */
1804
1805 if (UNLIKELY(NATIVE_UTF8_TO_I8(*adjusted_s0)
1806 >= FIRST_START_BYTE_THAT_IS_DEFINITELY_SUPER))
ea5ced44 1807 {
2b5e7bc2
KW
1808 possible_problems |= UTF8_GOT_SUPER;
1809 }
1810 else if (curlen > 1) {
1811 if (UNLIKELY(IS_UTF8_2_BYTE_SUPER(
1812 NATIVE_UTF8_TO_I8(*adjusted_s0),
1813 NATIVE_UTF8_TO_I8(*(adjusted_s0 + 1)))))
ea5ced44 1814 {
2b5e7bc2 1815 possible_problems |= UTF8_GOT_SUPER;
ea5ced44 1816 }
2b5e7bc2
KW
1817 else if (UNLIKELY(IS_UTF8_2_BYTE_SURROGATE(
1818 NATIVE_UTF8_TO_I8(*adjusted_s0),
1819 NATIVE_UTF8_TO_I8(*(adjusted_s0 + 1)))))
1820 {
1821 possible_problems |= UTF8_GOT_SURROGATE;
ea5ced44
KW
1822 }
1823 }
c0236afe 1824
2b5e7bc2
KW
1825 /* We need a complete well-formed UTF-8 character to discern
1826 * non-characters, so can't look for them here */
1827 }
1828 }
949cf498 1829
2b5e7bc2
KW
1830 ready_to_handle_errors:
1831
1832 /* At this point:
1833 * curlen contains the number of bytes in the sequence that
1834 * this call should advance the input by.
e308b348
KW
1835 * avail_len gives the available number of bytes passed in, but
1836 * only if this is less than the expected number of
1837 * bytes, based on the code point's start byte.
2b5e7bc2
KW
1838 * possible_problems' is 0 if there weren't any problems; otherwise a bit
1839 * is set in it for each potential problem found.
1840 * uv contains the code point the input sequence
1841 * represents; or if there is a problem that prevents
1842 * a well-defined value from being computed, it is
1843 * some subsitute value, typically the REPLACEMENT
1844 * CHARACTER.
1845 * s0 points to the first byte of the character
56576a04
KW
1846 * s points to just after were we left off processing
1847 * the character
1848 * send points to just after where that character should
1849 * end, based on how many bytes the start byte tells
1850 * us should be in it, but no further than s0 +
1851 * avail_len
2b5e7bc2 1852 */
eb83ed87 1853
2b5e7bc2
KW
1854 if (UNLIKELY(possible_problems)) {
1855 bool disallowed = FALSE;
1856 const U32 orig_problems = possible_problems;
1857
37657a5b
KW
1858 if (msgs) {
1859 *msgs = NULL;
1860 }
1861
2b5e7bc2
KW
1862 while (possible_problems) { /* Handle each possible problem */
1863 UV pack_warn = 0;
1864 char * message = NULL;
37657a5b 1865 U32 this_flag_bit = 0;
2b5e7bc2
KW
1866
1867 /* Each 'if' clause handles one problem. They are ordered so that
1868 * the first ones' messages will be displayed before the later
6c64cd9d
KW
1869 * ones; this is kinda in decreasing severity order. But the
1870 * overlong must come last, as it changes 'uv' looked at by the
1871 * others */
2b5e7bc2
KW
1872 if (possible_problems & UTF8_GOT_OVERFLOW) {
1873
56576a04
KW
1874 /* Overflow means also got a super and are using Perl's
1875 * extended UTF-8, but we handle all three cases here */
2b5e7bc2 1876 possible_problems
d044b7a7 1877 &= ~(UTF8_GOT_OVERFLOW|UTF8_GOT_SUPER|UTF8_GOT_PERL_EXTENDED);
f9380377
KW
1878 *errors |= UTF8_GOT_OVERFLOW;
1879
1880 /* But the API says we flag all errors found */
1881 if (flags & (UTF8_WARN_SUPER|UTF8_DISALLOW_SUPER)) {
1882 *errors |= UTF8_GOT_SUPER;
1883 }
ddb65933 1884 if (flags
d044b7a7 1885 & (UTF8_WARN_PERL_EXTENDED|UTF8_DISALLOW_PERL_EXTENDED))
ddb65933 1886 {
d044b7a7 1887 *errors |= UTF8_GOT_PERL_EXTENDED;
f9380377 1888 }
2b5e7bc2 1889
d60baaa7 1890 /* Disallow if any of the three categories say to */
56576a04 1891 if ( ! (flags & UTF8_ALLOW_OVERFLOW)
d60baaa7 1892 || (flags & ( UTF8_DISALLOW_SUPER
d044b7a7 1893 |UTF8_DISALLOW_PERL_EXTENDED)))
d60baaa7
KW
1894 {
1895 disallowed = TRUE;
1896 }
1897
d22ec717
KW
1898 /* Likewise, warn if any say to */
1899 if ( ! (flags & UTF8_ALLOW_OVERFLOW)
1900 || (flags & (UTF8_WARN_SUPER|UTF8_WARN_PERL_EXTENDED)))
d60baaa7 1901 {
2b5e7bc2 1902
ddb65933
KW
1903 /* The warnings code explicitly says it doesn't handle the
1904 * case of packWARN2 and two categories which have
1905 * parent-child relationship. Even if it works now to
1906 * raise the warning if either is enabled, it wouldn't
1907 * necessarily do so in the future. We output (only) the
56576a04 1908 * most dire warning */
ddb65933 1909 if (! (flags & UTF8_CHECK_ONLY)) {
37657a5b 1910 if (msgs || ckWARN_d(WARN_UTF8)) {
ddb65933
KW
1911 pack_warn = packWARN(WARN_UTF8);
1912 }
37657a5b 1913 else if (msgs || ckWARN_d(WARN_NON_UNICODE)) {
ddb65933
KW
1914 pack_warn = packWARN(WARN_NON_UNICODE);
1915 }
1916 if (pack_warn) {
1917 message = Perl_form(aTHX_ "%s: %s (overflows)",
1918 malformed_text,
05b9033b 1919 _byte_dump_string(s0, curlen, 0));
37657a5b 1920 this_flag_bit = UTF8_GOT_OVERFLOW;
ddb65933 1921 }
2b5e7bc2
KW
1922 }
1923 }
1924 }
1925 else if (possible_problems & UTF8_GOT_EMPTY) {
1926 possible_problems &= ~UTF8_GOT_EMPTY;
f9380377 1927 *errors |= UTF8_GOT_EMPTY;
2b5e7bc2
KW
1928
1929 if (! (flags & UTF8_ALLOW_EMPTY)) {
d1f8d421
KW
1930
1931 /* This so-called malformation is now treated as a bug in
1932 * the caller. If you have nothing to decode, skip calling
1933 * this function */
1934 assert(0);
1935
2b5e7bc2 1936 disallowed = TRUE;
37657a5b
KW
1937 if ( (msgs
1938 || ckWARN_d(WARN_UTF8)) && ! (flags & UTF8_CHECK_ONLY))
1939 {
2b5e7bc2
KW
1940 pack_warn = packWARN(WARN_UTF8);
1941 message = Perl_form(aTHX_ "%s (empty string)",
1942 malformed_text);
37657a5b 1943 this_flag_bit = UTF8_GOT_EMPTY;
2b5e7bc2
KW
1944 }
1945 }
1946 }
1947 else if (possible_problems & UTF8_GOT_CONTINUATION) {
1948 possible_problems &= ~UTF8_GOT_CONTINUATION;
f9380377 1949 *errors |= UTF8_GOT_CONTINUATION;
2b5e7bc2
KW
1950
1951 if (! (flags & UTF8_ALLOW_CONTINUATION)) {
1952 disallowed = TRUE;
37657a5b
KW
1953 if (( msgs
1954 || ckWARN_d(WARN_UTF8)) && ! (flags & UTF8_CHECK_ONLY))
1955 {
2b5e7bc2
KW
1956 pack_warn = packWARN(WARN_UTF8);
1957 message = Perl_form(aTHX_
1958 "%s: %s (unexpected continuation byte 0x%02x,"
1959 " with no preceding start byte)",
1960 malformed_text,
7e2f38b2 1961 _byte_dump_string(s0, 1, 0), *s0);
37657a5b 1962 this_flag_bit = UTF8_GOT_CONTINUATION;
2b5e7bc2
KW
1963 }
1964 }
1965 }
2b5e7bc2
KW
1966 else if (possible_problems & UTF8_GOT_SHORT) {
1967 possible_problems &= ~UTF8_GOT_SHORT;
f9380377 1968 *errors |= UTF8_GOT_SHORT;
2b5e7bc2
KW
1969
1970 if (! (flags & UTF8_ALLOW_SHORT)) {
1971 disallowed = TRUE;
37657a5b
KW
1972 if (( msgs
1973 || ckWARN_d(WARN_UTF8)) && ! (flags & UTF8_CHECK_ONLY))
1974 {
2b5e7bc2
KW
1975 pack_warn = packWARN(WARN_UTF8);
1976 message = Perl_form(aTHX_
56576a04
KW
1977 "%s: %s (too short; %d byte%s available, need %d)",
1978 malformed_text,
1979 _byte_dump_string(s0, send - s0, 0),
1980 (int)avail_len,
1981 avail_len == 1 ? "" : "s",
1982 (int)expectlen);
37657a5b 1983 this_flag_bit = UTF8_GOT_SHORT;
2b5e7bc2
KW
1984 }
1985 }
ba210ebe 1986
2b5e7bc2 1987 }
e308b348
KW
1988 else if (possible_problems & UTF8_GOT_NON_CONTINUATION) {
1989 possible_problems &= ~UTF8_GOT_NON_CONTINUATION;
1990 *errors |= UTF8_GOT_NON_CONTINUATION;
1991
1992 if (! (flags & UTF8_ALLOW_NON_CONTINUATION)) {
1993 disallowed = TRUE;
37657a5b
KW
1994 if (( msgs
1995 || ckWARN_d(WARN_UTF8)) && ! (flags & UTF8_CHECK_ONLY))
1996 {
99a765e9
KW
1997
1998 /* If we don't know for sure that the input length is
1999 * valid, avoid as much as possible reading past the
2000 * end of the buffer */
2001 int printlen = (flags & _UTF8_NO_CONFIDENCE_IN_CURLEN)
2002 ? s - s0
2003 : send - s0;
e308b348
KW
2004 pack_warn = packWARN(WARN_UTF8);
2005 message = Perl_form(aTHX_ "%s",
2006 unexpected_non_continuation_text(s0,
99a765e9 2007 printlen,
e308b348
KW
2008 s - s0,
2009 (int) expectlen));
37657a5b 2010 this_flag_bit = UTF8_GOT_NON_CONTINUATION;
e308b348
KW
2011 }
2012 }
2013 }
2b5e7bc2
KW
2014 else if (possible_problems & UTF8_GOT_SURROGATE) {
2015 possible_problems &= ~UTF8_GOT_SURROGATE;
2016
f9380377
KW
2017 if (flags & UTF8_WARN_SURROGATE) {
2018 *errors |= UTF8_GOT_SURROGATE;
2019
2020 if ( ! (flags & UTF8_CHECK_ONLY)
37657a5b 2021 && (msgs || ckWARN_d(WARN_SURROGATE)))
f9380377 2022 {
2b5e7bc2
KW
2023 pack_warn = packWARN(WARN_SURROGATE);
2024
2025 /* These are the only errors that can occur with a
2026 * surrogate when the 'uv' isn't valid */
2027 if (orig_problems & UTF8_GOT_TOO_SHORT) {
2028 message = Perl_form(aTHX_
2029 "UTF-16 surrogate (any UTF-8 sequence that"
2030 " starts with \"%s\" is for a surrogate)",
7e2f38b2 2031 _byte_dump_string(s0, curlen, 0));
2b5e7bc2
KW
2032 }
2033 else {
c94c2f39 2034 message = Perl_form(aTHX_ surrogate_cp_format, uv);
2b5e7bc2 2035 }
37657a5b 2036 this_flag_bit = UTF8_GOT_SURROGATE;
f9380377 2037 }
2b5e7bc2 2038 }
ba210ebe 2039
2b5e7bc2
KW
2040 if (flags & UTF8_DISALLOW_SURROGATE) {
2041 disallowed = TRUE;
f9380377 2042 *errors |= UTF8_GOT_SURROGATE;
2b5e7bc2
KW
2043 }
2044 }
2045 else if (possible_problems & UTF8_GOT_SUPER) {
2046 possible_problems &= ~UTF8_GOT_SUPER;
949cf498 2047
f9380377
KW
2048 if (flags & UTF8_WARN_SUPER) {
2049 *errors |= UTF8_GOT_SUPER;
2050
2051 if ( ! (flags & UTF8_CHECK_ONLY)
37657a5b 2052 && (msgs || ckWARN_d(WARN_NON_UNICODE)))
f9380377 2053 {
2b5e7bc2
KW
2054 pack_warn = packWARN(WARN_NON_UNICODE);
2055
2056 if (orig_problems & UTF8_GOT_TOO_SHORT) {
2057 message = Perl_form(aTHX_
2058 "Any UTF-8 sequence that starts with"
2059 " \"%s\" is for a non-Unicode code point,"
2060 " may not be portable",
7e2f38b2 2061 _byte_dump_string(s0, curlen, 0));
2b5e7bc2
KW
2062 }
2063 else {
c94c2f39 2064 message = Perl_form(aTHX_ super_cp_format, uv);
2b5e7bc2 2065 }
37657a5b 2066 this_flag_bit = UTF8_GOT_SUPER;
f9380377 2067 }
2b5e7bc2 2068 }
ba210ebe 2069
57ff5f59
KW
2070 /* Test for Perl's extended UTF-8 after the regular SUPER ones,
2071 * and before possibly bailing out, so that the more dire
2072 * warning will override the regular one. */
2073 if (UNLIKELY(isUTF8_PERL_EXTENDED(s0))) {
2b5e7bc2 2074 if ( ! (flags & UTF8_CHECK_ONLY)
d044b7a7 2075 && (flags & (UTF8_WARN_PERL_EXTENDED|UTF8_WARN_SUPER))
37657a5b 2076 && (msgs || ckWARN_d(WARN_NON_UNICODE)))
2b5e7bc2 2077 {
db0f09e6 2078 pack_warn = packWARN(WARN_NON_UNICODE);
2b5e7bc2 2079
57ff5f59
KW
2080 /* If it is an overlong that evaluates to a code point
2081 * that doesn't have to use the Perl extended UTF-8, it
2082 * still used it, and so we output a message that
2083 * doesn't refer to the code point. The same is true
2084 * if there was a SHORT malformation where the code
2085 * point is not valid. In that case, 'uv' will have
2086 * been set to the REPLACEMENT CHAR, and the message
2087 * below without the code point in it will be selected
2088 * */
2089 if (UNICODE_IS_PERL_EXTENDED(uv)) {
2b5e7bc2 2090 message = Perl_form(aTHX_
57ff5f59 2091 perl_extended_cp_format, uv);
2b5e7bc2
KW
2092 }
2093 else {
2094 message = Perl_form(aTHX_
57ff5f59
KW
2095 "Any UTF-8 sequence that starts with"
2096 " \"%s\" is a Perl extension, and"
2097 " so is not portable",
2098 _byte_dump_string(s0, curlen, 0));
2b5e7bc2 2099 }
37657a5b 2100 this_flag_bit = UTF8_GOT_PERL_EXTENDED;
2b5e7bc2
KW
2101 }
2102
d044b7a7
KW
2103 if (flags & ( UTF8_WARN_PERL_EXTENDED
2104 |UTF8_DISALLOW_PERL_EXTENDED))
ddb65933 2105 {
d044b7a7 2106 *errors |= UTF8_GOT_PERL_EXTENDED;
f9380377 2107
d044b7a7 2108 if (flags & UTF8_DISALLOW_PERL_EXTENDED) {
f9380377
KW
2109 disallowed = TRUE;
2110 }
2b5e7bc2
KW
2111 }
2112 }
eb83ed87 2113
2b5e7bc2 2114 if (flags & UTF8_DISALLOW_SUPER) {
f9380377 2115 *errors |= UTF8_GOT_SUPER;
2b5e7bc2
KW
2116 disallowed = TRUE;
2117 }
2b5e7bc2
KW
2118 }
2119 else if (possible_problems & UTF8_GOT_NONCHAR) {
2120 possible_problems &= ~UTF8_GOT_NONCHAR;
ba210ebe 2121
f9380377
KW
2122 if (flags & UTF8_WARN_NONCHAR) {
2123 *errors |= UTF8_GOT_NONCHAR;
2124
2125 if ( ! (flags & UTF8_CHECK_ONLY)
37657a5b 2126 && (msgs || ckWARN_d(WARN_NONCHAR)))
f9380377 2127 {
2b5e7bc2
KW
2128 /* The code above should have guaranteed that we don't
2129 * get here with errors other than overlong */
2130 assert (! (orig_problems
2131 & ~(UTF8_GOT_LONG|UTF8_GOT_NONCHAR)));
2132
2133 pack_warn = packWARN(WARN_NONCHAR);
c94c2f39 2134 message = Perl_form(aTHX_ nonchar_cp_format, uv);
37657a5b 2135 this_flag_bit = UTF8_GOT_NONCHAR;
f9380377 2136 }
2b5e7bc2 2137 }
5b311467 2138
2b5e7bc2
KW
2139 if (flags & UTF8_DISALLOW_NONCHAR) {
2140 disallowed = TRUE;
f9380377 2141 *errors |= UTF8_GOT_NONCHAR;
2b5e7bc2 2142 }
6c64cd9d
KW
2143 }
2144 else if (possible_problems & UTF8_GOT_LONG) {
2145 possible_problems &= ~UTF8_GOT_LONG;
2146 *errors |= UTF8_GOT_LONG;
2147
2148 if (flags & UTF8_ALLOW_LONG) {
2149
2150 /* We don't allow the actual overlong value, unless the
2151 * special extra bit is also set */
2152 if (! (flags & ( UTF8_ALLOW_LONG_AND_ITS_VALUE
2153 & ~UTF8_ALLOW_LONG)))
2154 {
2155 uv = UNICODE_REPLACEMENT;
2156 }
2157 }
2158 else {
2159 disallowed = TRUE;
2160
37657a5b
KW
2161 if (( msgs
2162 || ckWARN_d(WARN_UTF8)) && ! (flags & UTF8_CHECK_ONLY))
2163 {
6c64cd9d
KW
2164 pack_warn = packWARN(WARN_UTF8);
2165
2166 /* These error types cause 'uv' to be something that
2167 * isn't what was intended, so can't use it in the
2168 * message. The other error types either can't
2169 * generate an overlong, or else the 'uv' is valid */
2170 if (orig_problems &
2171 (UTF8_GOT_TOO_SHORT|UTF8_GOT_OVERFLOW))
2172 {
2173 message = Perl_form(aTHX_
2174 "%s: %s (any UTF-8 sequence that starts"
2175 " with \"%s\" is overlong which can and"
2176 " should be represented with a"
2177 " different, shorter sequence)",
2178 malformed_text,
2179 _byte_dump_string(s0, send - s0, 0),
2180 _byte_dump_string(s0, curlen, 0));
2181 }
2182 else {
2183 U8 tmpbuf[UTF8_MAXBYTES+1];
1be62ab9
KW
2184 const U8 * const e = uvoffuni_to_utf8_flags(tmpbuf,
2185 uv, 0);
d819dc50
KW
2186 /* Don't use U+ for non-Unicode code points, which
2187 * includes those in the Latin1 range */
2188 const char * preface = ( uv > PERL_UNICODE_MAX
2189#ifdef EBCDIC
2190 || uv <= 0xFF
2191#endif
2192 )
2193 ? "0x"
2194 : "U+";
6c64cd9d
KW
2195 message = Perl_form(aTHX_
2196 "%s: %s (overlong; instead use %s to represent"
2197 " %s%0*" UVXf ")",
2198 malformed_text,
2199 _byte_dump_string(s0, send - s0, 0),
2200 _byte_dump_string(tmpbuf, e - tmpbuf, 0),
2201 preface,
2202 ((uv < 256) ? 2 : 4), /* Field width of 2 for
2203 small code points */
1be62ab9 2204 UNI_TO_NATIVE(uv));
6c64cd9d 2205 }
37657a5b 2206 this_flag_bit = UTF8_GOT_LONG;
6c64cd9d
KW
2207 }
2208 }
2b5e7bc2
KW
2209 } /* End of looking through the possible flags */
2210
2211 /* Display the message (if any) for the problem being handled in
2212 * this iteration of the loop */
2213 if (message) {
37657a5b 2214 if (msgs) {
37657a5b
KW
2215 assert(this_flag_bit);
2216
2217 if (*msgs == NULL) {
2218 *msgs = newAV();
2219 }
2220
bb07812e
KW
2221 av_push(*msgs, newRV_noinc((SV*) new_msg_hv(message,
2222 pack_warn,
2223 this_flag_bit)));
37657a5b
KW
2224 }
2225 else if (PL_op)
2b5e7bc2
KW
2226 Perl_warner(aTHX_ pack_warn, "%s in %s", message,
2227 OP_DESC(PL_op));
2228 else
2229 Perl_warner(aTHX_ pack_warn, "%s", message);
2230 }
ddb65933 2231 } /* End of 'while (possible_problems)' */
a0dbb045 2232
2b5e7bc2
KW
2233 /* Since there was a possible problem, the returned length may need to
2234 * be changed from the one stored at the beginning of this function.
2235 * Instead of trying to figure out if that's needed, just do it. */
2236 if (retlen) {
2237 *retlen = curlen;
2238 }
a0dbb045 2239
2b5e7bc2
KW
2240 if (disallowed) {
2241 if (flags & UTF8_CHECK_ONLY && retlen) {
2242 *retlen = ((STRLEN) -1);
2243 }
2244 return 0;
2245 }
eb83ed87 2246 }
ba210ebe 2247
2b5e7bc2 2248 return UNI_TO_NATIVE(uv);
a0ed51b3
LW
2249}
2250
8e84507e 2251/*
ec5f19d0
KW
2252=for apidoc utf8_to_uvchr_buf
2253
2254Returns the native code point of the first character in the string C<s> which
2255is assumed to be in UTF-8 encoding; C<send> points to 1 beyond the end of C<s>.
524080c4 2256C<*retlen> will be set to the length, in bytes, of that character.
ec5f19d0 2257
524080c4
KW
2258If C<s> does not point to a well-formed UTF-8 character and UTF8 warnings are
2259enabled, zero is returned and C<*retlen> is set (if C<retlen> isn't
796b6530 2260C<NULL>) to -1. If those warnings are off, the computed value, if well-defined
173db420 2261(or the Unicode REPLACEMENT CHARACTER if not), is silently returned, and
796b6530 2262C<*retlen> is set (if C<retlen> isn't C<NULL>) so that (S<C<s> + C<*retlen>>) is
173db420 2263the next possible position in C<s> that could begin a non-malformed character.
de69f3af 2264See L</utf8n_to_uvchr> for details on when the REPLACEMENT CHARACTER is
173db420 2265returned.
ec5f19d0
KW
2266
2267=cut
52be2536
KW
2268
2269Also implemented as a macro in utf8.h
2270
ec5f19d0
KW
2271*/
2272
2273
2274UV
2275Perl_utf8_to_uvchr_buf(pTHX_ const U8 *s, const U8 *send, STRLEN *retlen)
2276{
7f974d7e
KW
2277 PERL_ARGS_ASSERT_UTF8_TO_UVCHR_BUF;
2278
9a9a6c98 2279 return utf8_to_uvchr_buf_helper(s, send, retlen);
ec5f19d0
KW
2280}
2281
52be2536
KW
2282/* This is marked as deprecated
2283 *
ec5f19d0
KW
2284=for apidoc utf8_to_uvuni_buf
2285
de69f3af
KW
2286Only in very rare circumstances should code need to be dealing in Unicode
2287(as opposed to native) code points. In those few cases, use
09232555
KW
2288C<L<NATIVE_TO_UNI(utf8_to_uvchr_buf(...))|perlapi/utf8_to_uvchr_buf>> instead.
2289If you are not absolutely sure this is one of those cases, then assume it isn't
2290and use plain C<utf8_to_uvchr_buf> instead.
4f83cdcd
KW
2291
2292Returns the Unicode (not-native) code point of the first character in the
2293string C<s> which
ec5f19d0
KW
2294is assumed to be in UTF-8 encoding; C<send> points to 1 beyond the end of C<s>.
2295C<retlen> will be set to the length, in bytes, of that character.
2296
524080c4
KW
2297If C<s> does not point to a well-formed UTF-8 character and UTF8 warnings are
2298enabled, zero is returned and C<*retlen> is set (if C<retlen> isn't
2299NULL) to -1. If those warnings are off, the computed value if well-defined (or
2300the Unicode REPLACEMENT CHARACTER, if not) is silently returned, and C<*retlen>
2301is set (if C<retlen> isn't NULL) so that (S<C<s> + C<*retlen>>) is the
2302next possible position in C<s> that could begin a non-malformed character.
09232555
KW
2303See L<perlapi/utf8n_to_uvchr> for details on when the REPLACEMENT CHARACTER is
2304returned.
ec5f19d0
KW
2305
2306=cut
2307*/
2308
2309UV
2310Perl_utf8_to_uvuni_buf(pTHX_ const U8 *s, const U8 *send, STRLEN *retlen)
2311{
2312 PERL_ARGS_ASSERT_UTF8_TO_UVUNI_BUF;
2313
2314 assert(send > s);
2315
5962d97e 2316 return NATIVE_TO_UNI(utf8_to_uvchr_buf(s, send, retlen));
ec5f19d0
KW
2317}
2318
b76347f2 2319/*
87cea99e 2320=for apidoc utf8_length
b76347f2 2321
b2e7ed74
KW
2322Returns the number of characters in the sequence of UTF-8-encoded bytes starting
2323at C<s> and ending at the byte just before C<e>. If <s> and <e> point to the
2324same place, it returns 0 with no warning raised.
2325
2326If C<e E<lt> s> or if the scan would end up past C<e>, it raises a UTF8 warning
2327and returns the number of valid characters.
b76347f2
JH
2328
2329=cut
2330*/
2331
2332STRLEN
35a4481c 2333Perl_utf8_length(pTHX_ const U8 *s, const U8 *e)
b76347f2
JH
2334{
2335 STRLEN len = 0;
2336
7918f24d
NC
2337 PERL_ARGS_ASSERT_UTF8_LENGTH;
2338
8850bf83
JH
2339 /* Note: cannot use UTF8_IS_...() too eagerly here since e.g.
2340 * the bitops (especially ~) can create illegal UTF-8.
2341 * In other words: in Perl UTF-8 is not just for Unicode. */
2342
12c43b0a 2343 if (UNLIKELY(e < s))
a3b680e6 2344 goto warn_and_return;
b76347f2 2345 while (s < e) {
4cbf4130 2346 s += UTF8SKIP(s);
8e91ec7f
AV
2347 len++;
2348 }
2349
12c43b0a 2350 if (UNLIKELY(e != s)) {
8e91ec7f
AV
2351 len--;
2352 warn_and_return:
9b387841
NC
2353 if (PL_op)
2354 Perl_ck_warner_d(aTHX_ packWARN(WARN_UTF8),
2355 "%s in %s", unees, OP_DESC(PL_op));
2356 else
61a12c31 2357 Perl_ck_warner_d(aTHX_ packWARN(WARN_UTF8), "%s", unees);
b76347f2
JH
2358 }
2359
2360 return len;
2361}
2362
b06226ff 2363/*
fed3ba5d
NC
2364=for apidoc bytes_cmp_utf8
2365
a1433954 2366Compares the sequence of characters (stored as octets) in C<b>, C<blen> with the
72d33970
FC
2367sequence of characters (stored as UTF-8)
2368in C<u>, C<ulen>. Returns 0 if they are
fed3ba5d
NC
2369equal, -1 or -2 if the first string is less than the second string, +1 or +2
2370if the first string is greater than the second string.
2371
2372-1 or +1 is returned if the shorter string was identical to the start of the
72d33970
FC
2373longer string. -2 or +2 is returned if
2374there was a difference between characters
fed3ba5d
NC
2375within the strings.
2376
2377=cut
2378*/
2379
2380int
2381Perl_bytes_cmp_utf8(pTHX_ const U8 *b, STRLEN blen, const U8 *u, STRLEN ulen)
2382{
2383 const U8 *const bend = b + blen;
2384 const U8 *const uend = u + ulen;
2385
2386 PERL_ARGS_ASSERT_BYTES_CMP_UTF8;
fed3ba5d
NC
2387
2388 while (b < bend && u < uend) {
2389 U8 c = *u++;
2390 if (!UTF8_IS_INVARIANT(c)) {
2391 if (UTF8_IS_DOWNGRADEABLE_START(c)) {
2392 if (u < uend) {
2393 U8 c1 = *u++;
2394 if (UTF8_IS_CONTINUATION(c1)) {
a62b247b 2395 c = EIGHT_BIT_UTF8_TO_NATIVE(c, c1);
fed3ba5d 2396 } else {
2b5e7bc2 2397 /* diag_listed_as: Malformed UTF-8 character%s */
fed3ba5d 2398 Perl_ck_warner_d(aTHX_ packWARN(WARN_UTF8),
56576a04
KW
2399 "%s %s%s",
2400 unexpected_non_continuation_text(u - 2, 2, 1, 2),
2401 PL_op ? " in " : "",
2402 PL_op ? OP_DESC(PL_op) : "");
fed3ba5d
NC
2403 return -2;
2404 }
2405 } else {
2406 if (PL_op)
2407 Perl_ck_warner_d(aTHX_ packWARN(WARN_UTF8),
2408 "%s in %s", unees, OP_DESC(PL_op));
2409 else
61a12c31 2410 Perl_ck_warner_d(aTHX_ packWARN(WARN_UTF8), "%s", unees);
fed3ba5d
NC
2411 return -2; /* Really want to return undef :-) */
2412 }
2413 } else {
2414 return -2;
2415 }
2416 }
2417 if (*b != c) {
2418 return *b < c ? -2 : +2;
2419 }
2420 ++b;
2421 }
2422
2423 if (b == bend && u == uend)
2424 return 0;
2425
2426 return b < bend ? +1 : -1;
2427}
2428
2429/*
87cea99e 2430=for apidoc utf8_to_bytes
6940069f 2431
3bc0c78c 2432Converts a string C<"s"> of length C<*lenp> from UTF-8 into native byte encoding.
a1433954 2433Unlike L</bytes_to_utf8>, this over-writes the original string, and
09af0336 2434updates C<*lenp> to contain the new length.
3bc0c78c
KW
2435Returns zero on failure (leaving C<"s"> unchanged) setting C<*lenp> to -1.
2436
2437Upon successful return, the number of variants in the string can be computed by
23b37b12
KW
2438having saved the value of C<*lenp> before the call, and subtracting the
2439after-call value of C<*lenp> from it.
6940069f 2440
a1433954 2441If you need a copy of the string, see L</bytes_from_utf8>.
95be277c 2442
6940069f
GS
2443=cut
2444*/
2445
2446U8 *
09af0336 2447Perl_utf8_to_bytes(pTHX_ U8 *s, STRLEN *lenp)
6940069f 2448{
9fe0d3c2 2449 U8 * first_variant;
246fae53 2450
7918f24d 2451 PERL_ARGS_ASSERT_UTF8_TO_BYTES;
81611534 2452 PERL_UNUSED_CONTEXT;
7918f24d 2453
9fe0d3c2 2454 /* This is a no-op if no variants at all in the input */
09af0336 2455 if (is_utf8_invariant_string_loc(s, *lenp, (const U8 **) &first_variant)) {
9fe0d3c2
KW
2456 return s;
2457 }
2458
2459 {
3c5aa262 2460 U8 * const save = s;
09af0336 2461 U8 * const send = s + *lenp;
3c5aa262
KW
2462 U8 * d;
2463
2464 /* Nothing before the first variant needs to be changed, so start the real
2465 * work there */
2466 s = first_variant;
2467 while (s < send) {
2468 if (! UTF8_IS_INVARIANT(*s)) {
2469 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(s, send)) {
09af0336 2470 *lenp = ((STRLEN) -1);
3c5aa262
KW
2471 return 0;
2472 }
2473 s++;
d59937ca
KW
2474 }
2475 s++;
dcad2880 2476 }
dcad2880 2477
3c5aa262
KW
2478 /* Is downgradable, so do it */
2479 d = s = first_variant;
2480 while (s < send) {
2481 U8 c = *s++;
2482 if (! UVCHR_IS_INVARIANT(c)) {
2483 /* Then it is two-byte encoded */
2484 c = EIGHT_BIT_UTF8_TO_NATIVE(c, *s);
2485 s++;
2486 }
2487 *d++ = c;
2488 }
2489 *d = '\0';
09af0336 2490 *lenp = d - save;
3c5aa262
KW
2491
2492 return save;
9fe0d3c2 2493 }
6940069f
GS
2494}
2495
2496/*
87cea99e 2497=for apidoc bytes_from_utf8
f9a63242 2498
09af0336 2499Converts a potentially UTF-8 encoded string C<s> of length C<*lenp> into native
41ae6089 2500byte encoding. On input, the boolean C<*is_utf8p> gives whether or not C<s> is
4f3d592d
KW
2501actually encoded in UTF-8.
2502
2503Unlike L</utf8_to_bytes> but like L</bytes_to_utf8>, this is non-destructive of
2504the input string.
2505
41ae6089
KW
2506Do nothing if C<*is_utf8p> is 0, or if there are code points in the string
2507not expressible in native byte encoding. In these cases, C<*is_utf8p> and
09af0336 2508C<*lenp> are unchanged, and the return value is the original C<s>.
4f3d592d 2509
41ae6089 2510Otherwise, C<*is_utf8p> is set to 0, and the return value is a pointer to a
4f3d592d 2511newly created string containing a downgraded copy of C<s>, and whose length is
9ff99fb3
KW
2512returned in C<*lenp>, updated. The new string is C<NUL>-terminated. The
2513caller is responsible for arranging for the memory used by this string to get
2514freed.
f9a63242 2515
3bc0c78c 2516Upon successful return, the number of variants in the string can be computed by
23b37b12
KW
2517having saved the value of C<*lenp> before the call, and subtracting the
2518after-call value of C<*lenp> from it.
3bc0c78c 2519
37607a96 2520=cut
976c1b08
KW
2521
2522There is a macro that avoids this function call, but this is retained for
2523anyone who calls it with the Perl_ prefix */
f9a63242
JH
2524
2525U8 *
41ae6089 2526Perl_bytes_from_utf8(pTHX_ const U8 *s, STRLEN *lenp, bool *is_utf8p)
f9a63242 2527{
7918f24d 2528 PERL_ARGS_ASSERT_BYTES_FROM_UTF8;
96a5add6 2529 PERL_UNUSED_CONTEXT;
f9a63242 2530
976c1b08
KW
2531 return bytes_from_utf8_loc(s, lenp, is_utf8p, NULL);
2532}
2533
2534/*
df6bd76f
KW
2535=for comment
2536skip apidoc
2537This is not currently externally documented because we don't want people to use
2538it for now. XXX Perhaps that is too paranoid, and it should be documented?
2539
2540=for apidoc bytes_from_utf8_loc
976c1b08
KW
2541
2542Like C<L</bytes_from_utf8>()>, but takes an extra parameter, a pointer to where
2543to store the location of the first character in C<"s"> that cannot be
2544converted to non-UTF8.
2545
2546If that parameter is C<NULL>, this function behaves identically to
2547C<bytes_from_utf8>.
2548
2549Otherwise if C<*is_utf8p> is 0 on input, the function behaves identically to
2550C<bytes_from_utf8>, except it also sets C<*first_non_downgradable> to C<NULL>.
2551
2552Otherwise, the function returns a newly created C<NUL>-terminated string
2553containing the non-UTF8 equivalent of the convertible first portion of
2554C<"s">. C<*lenp> is set to its length, not including the terminating C<NUL>.
2555If the entire input string was converted, C<*is_utf8p> is set to a FALSE value,
2556and C<*first_non_downgradable> is set to C<NULL>.
2557
2558Otherwise, C<*first_non_downgradable> set to point to the first byte of the
2559first character in the original string that wasn't converted. C<*is_utf8p> is
2560unchanged. Note that the new string may have length 0.
2561
2562Another way to look at it is, if C<*first_non_downgradable> is non-C<NULL> and
2563C<*is_utf8p> is TRUE, this function starts at the beginning of C<"s"> and
2564converts as many characters in it as possible stopping at the first one it
385b74be 2565finds that can't be converted to non-UTF-8. C<*first_non_downgradable> is
976c1b08
KW
2566set to point to that. The function returns the portion that could be converted
2567in a newly created C<NUL>-terminated string, and C<*lenp> is set to its length,
2568not including the terminating C<NUL>. If the very first character in the
2569original could not be converted, C<*lenp> will be 0, and the new string will
2570contain just a single C<NUL>. If the entire input string was converted,
2571C<*is_utf8p> is set to FALSE and C<*first_non_downgradable> is set to C<NULL>.
2572
2573Upon successful return, the number of variants in the converted portion of the
2574string can be computed by having saved the value of C<*lenp> before the call,
2575and subtracting the after-call value of C<*lenp> from it.
2576
2577=cut
2578
2579
2580*/
2581
2582U8 *
2583Perl_bytes_from_utf8_loc(const U8 *s, STRLEN *lenp, bool *is_utf8p, const U8** first_unconverted)
2584{
2585 U8 *d;
2586 const U8 *original = s;
2587 U8 *converted_start;
2588 const U8 *send = s + *lenp;
f9a63242 2589
976c1b08 2590 PERL_ARGS_ASSERT_BYTES_FROM_UTF8_LOC;
170a1c22 2591
976c1b08
KW
2592 if (! *is_utf8p) {
2593 if (first_unconverted) {
2594 *first_unconverted = NULL;
2595 }
2596
2597 return (U8 *) original;
2598 }
2599
2600 Newx(d, (*lenp) + 1, U8);
2601
2602 converted_start = d;
7299a045
KW
2603 while (s < send) {
2604 U8 c = *s++;
2605 if (! UTF8_IS_INVARIANT(c)) {
976c1b08
KW
2606
2607 /* Then it is multi-byte encoded. If the code point is above 0xFF,
2608 * have to stop now */
2609 if (UNLIKELY (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(s - 1, send))) {
2610 if (first_unconverted) {
2611 *first_unconverted = s - 1;
2612 goto finish_and_return;
2613 }
2614 else {
2615 Safefree(converted_start);
2616 return (U8 *) original;
2617 }
2618 }
2619
7299a045
KW
2620 c = EIGHT_BIT_UTF8_TO_NATIVE(c, *s);
2621 s++;
38af28cf 2622 }
7299a045
KW
2623 *d++ = c;
2624 }
170a1c22 2625
976c1b08
KW
2626 /* Here, converted the whole of the input */
2627 *is_utf8p = FALSE;
2628 if (first_unconverted) {
2629 *first_unconverted = NULL;
170a1c22 2630 }
976c1b08
KW
2631
2632 finish_and_return:
46a08a6f
KW
2633 *d = '\0';
2634 *lenp = d - converted_start;
976c1b08
KW
2635
2636 /* Trim unused space */
2637 Renew(converted_start, *lenp + 1, U8);
2638
2639 return converted_start;
f9a63242
JH
2640}
2641
2642/*
87cea99e 2643=for apidoc bytes_to_utf8
6940069f 2644
09af0336 2645Converts a string C<s> of length C<*lenp> bytes from the native encoding into
ff97e5cf 2646UTF-8.
09af0336 2647Returns a pointer to the newly-created string, and sets C<*lenp> to
9ff99fb3
KW
2648reflect the new length in bytes. The caller is responsible for arranging for
2649the memory used by this string to get freed.
6940069f 2650
3bc0c78c 2651Upon successful return, the number of variants in the string can be computed by
23b37b12 2652having saved the value of C<*lenp> before the call, and subtracting it from the
3bc0c78c
KW
2653after-call value of C<*lenp>.
2654
75200dff 2655A C<NUL> character will be written after the end of the string.
2bbc8d55
SP
2656
2657If you want to convert to UTF-8 from encodings other than
2658the native (Latin1 or EBCDIC),
a1433954 2659see L</sv_recode_to_utf8>().
c9ada85f 2660
497711e7 2661=cut
6940069f
GS
2662*/
2663
2664U8*
09af0336 2665Perl_bytes_to_utf8(pTHX_ const U8 *s, STRLEN *lenp)
6940069f 2666{
09af0336 2667 const U8 * const send = s + (*lenp);
6940069f
GS
2668 U8 *d;
2669 U8 *dst;
7918f24d
NC
2670
2671 PERL_ARGS_ASSERT_BYTES_TO_UTF8;
96a5add6 2672 PERL_UNUSED_CONTEXT;
6940069f 2673
d4662719
KW
2674 /* 1 for each byte + 1 for each byte that expands to two, + trailing NUL */
2675 Newx(d, (*lenp) + variant_under_utf8_count(s, send) + 1, U8);
6940069f
GS
2676 dst = d;
2677
2678 while (s < send) {
55d09dc8
KW
2679 append_utf8_from_native_byte(*s, &d);
2680 s++;
6940069f 2681 }
2e11cf67 2682
6940069f 2683 *d = '\0';
09af0336 2684 *lenp = d-dst;
2e11cf67 2685
6940069f
GS
2686 return dst;
2687}
2688
a0ed51b3 2689/*
624504c5
KW
2690 * Convert native (big-endian) UTF-16 to UTF-8. For reversed (little-endian),
2691 * use utf16_to_utf8_reversed().
a0ed51b3 2692 *
624504c5
KW
2693 * UTF-16 requires 2 bytes for every code point below 0x10000; otherwise 4 bytes.
2694 * UTF-8 requires 1-3 bytes for every code point below 0x1000; otherwise 4 bytes.
2695 * UTF-EBCDIC requires 1-4 bytes for every code point below 0x1000; otherwise 4-5 bytes.
2696 *
2697 * These functions don't check for overflow. The worst case is every code
2698 * point in the input is 2 bytes, and requires 4 bytes on output. (If the code
2699 * is never going to run in EBCDIC, it is 2 bytes requiring 3 on output.) Therefore the
2700 * destination must be pre-extended to 2 times the source length.
2701 *
2702 * Do not use in-place. We optimize for native, for obvious reasons. */
a0ed51b3
LW
2703
2704U8*
dea0fc0b 2705Perl_utf16_to_utf8(pTHX_ U8* p, U8* d, I32 bytelen, I32 *newlen)
a0ed51b3 2706{
dea0fc0b
JH
2707 U8* pend;
2708 U8* dstart = d;
2709
7918f24d
NC
2710 PERL_ARGS_ASSERT_UTF16_TO_UTF8;
2711
dea0fc0b 2712 if (bytelen & 1)
56576a04
KW
2713 Perl_croak(aTHX_ "panic: utf16_to_utf8: odd bytelen %" UVuf,
2714 (UV)bytelen);
dea0fc0b
JH
2715
2716 pend = p + bytelen;
2717
a0ed51b3 2718 while (p < pend) {
dea0fc0b
JH
2719 UV uv = (p[0] << 8) + p[1]; /* UTF-16BE */
2720 p += 2;
2d1545e5 2721 if (OFFUNI_IS_INVARIANT(uv)) {
56d37426 2722 *d++ = LATIN1_TO_NATIVE((U8) uv);
a0ed51b3
LW
2723 continue;
2724 }
56d37426
KW
2725 if (uv <= MAX_UTF8_TWO_BYTE) {
2726 *d++ = UTF8_TWO_BYTE_HI(UNI_TO_NATIVE(uv));
2727 *d++ = UTF8_TWO_BYTE_LO(UNI_TO_NATIVE(uv));
a0ed51b3
LW
2728 continue;
2729 }
ffd0a9d3 2730
46956fad
KW
2731#define FIRST_HIGH_SURROGATE UNICODE_SURROGATE_FIRST
2732#define LAST_HIGH_SURROGATE 0xDBFF
2733#define FIRST_LOW_SURROGATE 0xDC00
2734#define LAST_LOW_SURROGATE UNICODE_SURROGATE_LAST
ffd0a9d3 2735#define FIRST_IN_PLANE1 0x10000
e23c50db
KW
2736
2737 /* This assumes that most uses will be in the first Unicode plane, not
2738 * needing surrogates */
2739 if (UNLIKELY(uv >= UNICODE_SURROGATE_FIRST
2740 && uv <= UNICODE_SURROGATE_LAST))
2741 {
2742 if (UNLIKELY(p >= pend) || UNLIKELY(uv > LAST_HIGH_SURROGATE)) {
2743 Perl_croak(aTHX_ "Malformed UTF-16 surrogate");
2744 }
2745 else {
01ea242b 2746 UV low = (p[0] << 8) + p[1];
e23c50db
KW
2747 if ( UNLIKELY(low < FIRST_LOW_SURROGATE)
2748 || UNLIKELY(low > LAST_LOW_SURROGATE))
2749 {
01ea242b 2750 Perl_croak(aTHX_ "Malformed UTF-16 surrogate");
e23c50db
KW
2751 }
2752 p += 2;
46956fad 2753 uv = ((uv - FIRST_HIGH_SURROGATE) << 10)
ffd0a9d3 2754 + (low - FIRST_LOW_SURROGATE) + FIRST_IN_PLANE1;
01ea242b 2755 }
a0ed51b3 2756 }
56d37426
KW
2757#ifdef EBCDIC
2758 d = uvoffuni_to_utf8_flags(d, uv, 0);
2759#else
ffd0a9d3 2760 if (uv < FIRST_IN_PLANE1) {
eb160463
GS
2761 *d++ = (U8)(( uv >> 12) | 0xe0);
2762 *d++ = (U8)(((uv >> 6) & 0x3f) | 0x80);
2763 *d++ = (U8)(( uv & 0x3f) | 0x80);
a0ed51b3
LW
2764 continue;
2765 }
2766 else {
eb160463
GS
2767 *d++ = (U8)(( uv >> 18) | 0xf0);
2768 *d++ = (U8)(((uv >> 12) & 0x3f) | 0x80);
2769 *d++ = (U8)(((uv >> 6) & 0x3f) | 0x80);
2770 *d++ = (U8)(( uv & 0x3f) | 0x80);
a0ed51b3
LW
2771 continue;
2772 }
56d37426 2773#endif
a0ed51b3 2774 }
dea0fc0b 2775 *newlen = d - dstart;
a0ed51b3
LW
2776 return d;
2777}
2778
2779/* Note: this one is slightly destructive of the source. */
2780
2781U8*
dea0fc0b 2782Perl_utf16_to_utf8_reversed(pTHX_ U8* p, U8* d, I32 bytelen, I32 *newlen)
a0ed51b3
LW
2783{
2784 U8* s = (U8*)p;
d4c19fe8 2785 U8* const send = s + bytelen;
7918f24d
NC
2786
2787 PERL_ARGS_ASSERT_UTF16_TO_UTF8_REVERSED;
2788
e0ea5e2d 2789 if (bytelen & 1)
147e3846 2790 Perl_croak(aTHX_ "panic: utf16_to_utf8_reversed: odd bytelen %" UVuf,
e0ea5e2d
NC
2791 (UV)bytelen);
2792
a0ed51b3 2793 while (s < send) {
d4c19fe8 2794 const U8 tmp = s[0];
a0ed51b3
LW
2795 s[0] = s[1];
2796 s[1] = tmp;
2797 s += 2;
2798 }
dea0fc0b 2799 return utf16_to_utf8(p, d, bytelen, newlen);
a0ed51b3
LW
2800}
2801
922e8cb4
KW
2802bool
2803Perl__is_uni_FOO(pTHX_ const U8 classnum, const UV c)
2804{
1565c085 2805 dVAR;
dc31b55c 2806 return _invlist_contains_cp(PL_XPosix_ptrs[classnum], c);
922e8cb4
KW
2807}
2808
5092f92a 2809bool
eba68aa0
KW
2810Perl__is_uni_perl_idcont(pTHX_ UV c)
2811{
1565c085 2812 dVAR;
c12658c9 2813 return _invlist_contains_cp(PL_utf8_perl_idcont, c);
eba68aa0
KW
2814}
2815
2816bool
f91dcd13
KW
2817Perl__is_uni_perl_idstart(pTHX_ UV c)
2818{
1565c085 2819 dVAR;
c12658c9 2820 return _invlist_contains_cp(PL_utf8_perl_idstart, c);
f91dcd13
KW
2821}
2822
3a4c58c9 2823UV
56576a04
KW
2824Perl__to_upper_title_latin1(pTHX_ const U8 c, U8* p, STRLEN *lenp,
2825 const char S_or_s)
3a4c58c9
KW
2826{
2827 /* We have the latin1-range values compiled into the core, so just use
4a4088c4 2828 * those, converting the result to UTF-8. The only difference between upper
3a4c58c9
KW
2829 * and title case in this range is that LATIN_SMALL_LETTER_SHARP_S is
2830 * either "SS" or "Ss". Which one to use is passed into the routine in
2831 * 'S_or_s' to avoid a test */
2832
2833 UV converted = toUPPER_LATIN1_MOD(c);
2834
2835 PERL_ARGS_ASSERT__TO_UPPER_TITLE_LATIN1;
2836
2837 assert(S_or_s == 'S' || S_or_s == 's');
2838
6f2d5cbc 2839 if (UVCHR_IS_INVARIANT(converted)) { /* No difference between the two for
f4cd282c 2840 characters in this range */
3a4c58c9
KW
2841 *p = (U8) converted;
2842 *lenp = 1;
2843 return converted;
2844 }
2845
2846 /* toUPPER_LATIN1_MOD gives the correct results except for three outliers,
2847 * which it maps to one of them, so as to only have to have one check for
2848 * it in the main case */
2849 if (UNLIKELY(converted == LATIN_SMALL_LETTER_Y_WITH_DIAERESIS)) {
2850 switch (c) {
2851 case LATIN_SMALL_LETTER_Y_WITH_DIAERESIS:
2852 converted = LATIN_CAPITAL_LETTER_Y_WITH_DIAERESIS;
2853 break;
2854 case MICRO_SIGN:
2855 converted = GREEK_CAPITAL_LETTER_MU;
2856 break;
79e064b9
KW
2857#if UNICODE_MAJOR_VERSION > 2 \
2858 || (UNICODE_MAJOR_VERSION == 2 && UNICODE_DOT_VERSION >= 1 \
2859 && UNICODE_DOT_DOT_VERSION >= 8)
3a4c58c9
KW
2860 case LATIN_SMALL_LETTER_SHARP_S:
2861 *(p)++ = 'S';
2862 *p = S_or_s;
2863 *lenp = 2;
2864 return 'S';
79e064b9 2865#endif
3a4c58c9 2866 default:
56576a04
KW
2867 Perl_croak(aTHX_ "panic: to_upper_title_latin1 did not expect"
2868 " '%c' to map to '%c'",
2869 c, LATIN_SMALL_LETTER_Y_WITH_DIAERESIS);
e5964223 2870 NOT_REACHED; /* NOTREACHED */
3a4c58c9
KW
2871 }
2872 }
2873
2874 *(p)++ = UTF8_TWO_BYTE_HI(converted);
2875 *p = UTF8_TWO_BYTE_LO(converted);
2876 *lenp = 2;
2877
2878 return converted;
2879}
2880
fe63c520
KW
2881/* If compiled on an early Unicode version, there may not be auxiliary tables
2882 * */
2883#ifndef HAS_UC_AUX_TABLES
2884# define UC_AUX_TABLE_ptrs NULL
2885# define UC_AUX_TABLE_lengths NULL
2886#endif
2887#ifndef HAS_TC_AUX_TABLES
2888# define TC_AUX_TABLE_ptrs NULL
2889# define TC_AUX_TABLE_lengths NULL
2890#endif
2891#ifndef HAS_LC_AUX_TABLES
2892# define LC_AUX_TABLE_ptrs NULL
2893# define LC_AUX_TABLE_lengths NULL
2894#endif
2895#ifndef HAS_CF_AUX_TABLES
2896# define CF_AUX_TABLE_ptrs NULL
2897# define CF_AUX_TABLE_lengths NULL
2898#endif
2899#ifndef HAS_UC_AUX_TABLES
2900# define UC_AUX_TABLE_ptrs NULL
2901# define UC_AUX_TABLE_lengths NULL
2902#endif
2903
50bda2c3
KW
2904/* Call the function to convert a UTF-8 encoded character to the specified case.
2905 * Note that there may be more than one character in the result.
6fa2f9bc
KW
2906 * 's' is a pointer to the first byte of the input character
2907 * 'd' will be set to the first byte of the string of changed characters. It
50bda2c3 2908 * needs to have space for UTF8_MAXBYTES_CASE+1 bytes
6fa2f9bc 2909 * 'lenp' will be set to the length in bytes of the string of changed characters
50bda2c3 2910 *
56576a04 2911 * The functions return the ordinal of the first character in the string of
6fa2f9bc 2912 * 'd' */
56576a04 2913#define CALL_UPPER_CASE(uv, s, d, lenp) \
8946fcd9
KW
2914 _to_utf8_case(uv, s, d, lenp, PL_utf8_toupper, \
2915 Uppercase_Mapping_invmap, \
2916 UC_AUX_TABLE_ptrs, \
2917 UC_AUX_TABLE_lengths, \
2918 "uppercase")
56576a04 2919#define CALL_TITLE_CASE(uv, s, d, lenp) \
8946fcd9
KW
2920 _to_utf8_case(uv, s, d, lenp, PL_utf8_totitle, \
2921 Titlecase_Mapping_invmap, \
2922 TC_AUX_TABLE_ptrs, \
2923 TC_AUX_TABLE_lengths, \
2924 "titlecase")
56576a04 2925#define CALL_LOWER_CASE(uv, s, d, lenp) \
8946fcd9
KW
2926 _to_utf8_case(uv, s, d, lenp, PL_utf8_tolower, \
2927 Lowercase_Mapping_invmap, \
2928 LC_AUX_TABLE_ptrs, \
2929 LC_AUX_TABLE_lengths, \
2930 "lowercase")
2931
50bda2c3 2932
b9992569
KW
2933/* This additionally has the input parameter 'specials', which if non-zero will
2934 * cause this to use the specials hash for folding (meaning get full case
50bda2c3 2935 * folding); otherwise, when zero, this implies a simple case fold */
56576a04 2936#define CALL_FOLD_CASE(uv, s, d, lenp, specials) \
8946fcd9
KW
2937 (specials) \
2938 ? _to_utf8_case(uv, s, d, lenp, PL_utf8_tofold, \
2939 Case_Folding_invmap, \
2940 CF_AUX_TABLE_ptrs, \
2941 CF_AUX_TABLE_lengths, \
2942 "foldcase") \
2943 : _to_utf8_case(uv, s, d, lenp, PL_utf8_tosimplefold, \
2944 Simple_Case_Folding_invmap, \
2945 NULL, NULL, \
2946 "foldcase")
c3fd2246 2947
84afefe6
JH
2948UV
2949Perl_to_uni_upper(pTHX_ UV c, U8* p, STRLEN *lenp)
a0ed51b3 2950{
a1433954
KW
2951 /* Convert the Unicode character whose ordinal is <c> to its uppercase
2952 * version and store that in UTF-8 in <p> and its length in bytes in <lenp>.
2953 * Note that the <p> needs to be at least UTF8_MAXBYTES_CASE+1 bytes since
c3fd2246
KW
2954 * the changed version may be longer than the original character.
2955 *
2956 * The ordinal of the first character of the changed version is returned
2957 * (but note, as explained above, that there may be more.) */
2958
1565c085 2959 dVAR;
7918f24d
NC
2960 PERL_ARGS_ASSERT_TO_UNI_UPPER;
2961
3a4c58c9
KW
2962 if (c < 256) {
2963 return _to_upper_title_latin1((U8) c, p, lenp, 'S');
2964 }
2965
a13f1de4 2966 return CALL_UPPER_CASE(c, NULL, p, lenp);
a0ed51b3
LW
2967}
2968
84afefe6
JH
2969UV
2970Perl_to_uni_title(pTHX_ UV c, U8* p, STRLEN *lenp)
a0ed51b3 2971{
1565c085 2972 dVAR;
7918f24d
NC
2973 PERL_ARGS_ASSERT_TO_UNI_TITLE;
2974
3a4c58c9
KW
2975 if (c < 256) {
2976 return _to_upper_title_latin1((U8) c, p, lenp, 's');
2977 }
2978
a13f1de4 2979 return CALL_TITLE_CASE(c, NULL, p, lenp);
a0ed51b3
LW
2980}
2981
afc16117 2982STATIC U8
eaf412bf 2983S_to_lower_latin1(const U8 c, U8* p, STRLEN *lenp, const char dummy)
afc16117
KW
2984{
2985 /* We have the latin1-range values compiled into the core, so just use
4a4088c4 2986 * those, converting the result to UTF-8. Since the result is always just
a1433954 2987 * one character, we allow <p> to be NULL */
afc16117
KW
2988
2989 U8 converted = toLOWER_LATIN1(c);
2990
eaf412bf
KW
2991 PERL_UNUSED_ARG(dummy);
2992
afc16117 2993 if (p != NULL) {
6f2d5cbc 2994 if (NATIVE_BYTE_IS_INVARIANT(converted)) {
afc16117
KW
2995 *p = converted;
2996 *lenp = 1;
2997 }
2998 else {
430c9760
KW
2999 /* Result is known to always be < 256, so can use the EIGHT_BIT
3000 * macros */
3001 *p = UTF8_EIGHT_BIT_HI(converted);
3002 *(p+1) = UTF8_EIGHT_BIT_LO(converted);
afc16117
KW
3003 *lenp = 2;
3004 }
3005 }
3006 return converted;
3007}
3008
84afefe6
JH
3009UV
3010Perl_to_uni_lower(pTHX_ UV c, U8* p, STRLEN *lenp)
a0ed51b3 3011{
1565c085 3012 dVAR;
7918f24d
NC
3013 PERL_ARGS_ASSERT_TO_UNI_LOWER;
3014
afc16117 3015 if (c < 256) {
eaf412bf 3016 return to_lower_latin1((U8) c, p, lenp, 0 /* 0 is a dummy arg */ );
bca00c02
KW
3017 }
3018
a13f1de4 3019 return CALL_LOWER_CASE(c, NULL, p, lenp);
a0ed51b3
LW
3020}
3021
84afefe6 3022UV
7c0ab950 3023Perl__to_fold_latin1(const U8 c, U8* p, STRLEN *lenp, const unsigned int flags)
a1dde8de 3024{
51910141 3025 /* Corresponds to to_lower_latin1(); <flags> bits meanings:
1ca267a5 3026 * FOLD_FLAGS_NOMIX_ASCII iff non-ASCII to ASCII folds are prohibited
51910141 3027 * FOLD_FLAGS_FULL iff full folding is to be used;
1ca267a5
KW
3028 *
3029 * Not to be used for locale folds
51910141 3030 */
f673fad4 3031
a1dde8de
KW
3032 UV converted;
3033
3034 PERL_ARGS_ASSERT__TO_FOLD_LATIN1;
3035
1ca267a5
KW
3036 assert (! (flags & FOLD_FLAGS_LOCALE));
3037
659a7c2d 3038 if (UNLIKELY(c == MICRO_SIGN)) {
a1dde8de
KW
3039 converted = GREEK_SMALL_LETTER_MU;
3040 }
9b63e895
KW
3041#if UNICODE_MAJOR_VERSION > 3 /* no multifolds in early Unicode */ \
3042 || (UNICODE_MAJOR_VERSION == 3 && ( UNICODE_DOT_VERSION > 0) \
3043 || UNICODE_DOT_DOT_VERSION > 0)
659a7c2d
KW
3044 else if ( (flags & FOLD_FLAGS_FULL)
3045 && UNLIKELY(c == LATIN_SMALL_LETTER_SHARP_S))
3046 {
1ca267a5
KW
3047 /* If can't cross 127/128 boundary, can't return "ss"; instead return
3048 * two U+017F characters, as fc("\df") should eq fc("\x{17f}\x{17f}")
3049 * under those circumstances. */
3050 if (flags & FOLD_FLAGS_NOMIX_ASCII) {
3051 *lenp = 2 * sizeof(LATIN_SMALL_LETTER_LONG_S_UTF8) - 2;
3052 Copy(LATIN_SMALL_LETTER_LONG_S_UTF8 LATIN_SMALL_LETTER_LONG_S_UTF8,
3053 p, *lenp, U8);
3054 return LATIN_SMALL_LETTER_LONG_S;
3055 }
3056 else {
4f489194
KW
3057 *(p)++ = 's';
3058 *p = 's';
3059 *lenp = 2;
3060 return 's';
1ca267a5 3061 }
a1dde8de 3062 }
9b63e895 3063#endif
a1dde8de
KW
3064 else { /* In this range the fold of all other characters is their lower
3065 case */
3066 converted = toLOWER_LATIN1(c);
3067 }
3068
6f2d5cbc 3069 if (UVCHR_IS_INVARIANT(converted)) {
a1dde8de
KW
3070 *p = (U8) converted;
3071 *lenp = 1;
3072 }
3073 else {
3074 *(p)++ = UTF8_TWO_BYTE_HI(converted);
3075 *p = UTF8_TWO_BYTE_LO(converted);
3076 *lenp = 2;
3077 }
3078
3079 return converted;
3080}
3081
3082UV
31f05a37 3083Perl__to_uni_fold_flags(pTHX_ UV c, U8* p, STRLEN *lenp, U8 flags)
84afefe6 3084{
4b593389 3085
a0270393
KW
3086 /* Not currently externally documented, and subject to change
3087 * <flags> bits meanings:
3088 * FOLD_FLAGS_FULL iff full folding is to be used;
31f05a37
KW
3089 * FOLD_FLAGS_LOCALE is set iff the rules from the current underlying
3090 * locale are to be used.
a0270393
KW
3091 * FOLD_FLAGS_NOMIX_ASCII iff non-ASCII to ASCII folds are prohibited
3092 */
4b593389 3093
1565c085 3094 dVAR;
36bb2ab6 3095 PERL_ARGS_ASSERT__TO_UNI_FOLD_FLAGS;
7918f24d 3096
780fcc9f 3097 if (flags & FOLD_FLAGS_LOCALE) {
b257a28c
KW
3098 /* Treat a non-Turkic UTF-8 locale as not being in locale at all,
3099 * except for potentially warning */
8b7358b9 3100 _CHECK_AND_WARN_PROBLEMATIC_LOCALE;
b257a28c 3101 if (IN_UTF8_CTYPE_LOCALE && ! PL_in_utf8_turkic_locale) {
780fcc9f
KW
3102 flags &= ~FOLD_FLAGS_LOCALE;
3103 }
3104 else {
e7b7ac46 3105 goto needs_full_generality;
780fcc9f 3106 }
31f05a37
KW
3107 }
3108
a1dde8de 3109 if (c < 256) {
e7b7ac46 3110 return _to_fold_latin1((U8) c, p, lenp,
31f05a37 3111 flags & (FOLD_FLAGS_FULL | FOLD_FLAGS_NOMIX_ASCII));
a1dde8de
KW
3112 }
3113
2f306ab9 3114 /* Here, above 255. If no special needs, just use the macro */
a0270393 3115 if ( ! (flags & (FOLD_FLAGS_LOCALE|FOLD_FLAGS_NOMIX_ASCII))) {
a13f1de4 3116 return CALL_FOLD_CASE(c, NULL, p, lenp, flags & FOLD_FLAGS_FULL);
a0270393 3117 }
567b353c 3118 else { /* Otherwise, _toFOLD_utf8_flags has the intelligence to deal with
a0270393
KW
3119 the special flags. */
3120 U8 utf8_c[UTF8_MAXBYTES + 1];
e7b7ac46
KW
3121
3122 needs_full_generality:
a0270393 3123 uvchr_to_utf8(utf8_c, c);
56576a04
KW
3124 return _toFOLD_utf8_flags(utf8_c, utf8_c + sizeof(utf8_c),
3125 p, lenp, flags);
a0270393 3126 }
84afefe6
JH
3127}
3128
26483009 3129PERL_STATIC_INLINE bool
dd1a3ba7
KW
3130S_is_utf8_common(pTHX_ const U8 *const p, const U8 * const e,
3131 SV* const invlist)
da8c1a98
KW
3132{
3133 /* returns a boolean giving whether or not the UTF8-encoded character that
eb1f4bb4
KW
3134 * starts at <p>, and extending no further than <e - 1> is in the inversion
3135 * list <invlist>. */
da8c1a98 3136
b68ffe0c
KW
3137 UV cp = utf8n_to_uvchr(p, e - p, NULL, 0);
3138
dd1a3ba7 3139 PERL_ARGS_ASSERT_IS_UTF8_COMMON;
da8c1a98 3140
b68ffe0c 3141 if (cp == 0 && (p >= e || *p != '\0')) {
da8c1a98
KW
3142 _force_out_malformed_utf8_message(p, e, 0, 1);
3143 NOT_REACHED; /* NOTREACHED */
3144 }
3145
eb1f4bb4 3146 assert(invlist);
b68ffe0c 3147 return _invlist_contains_cp(invlist, cp);
da8c1a98
KW
3148}
3149
059703b0 3150#if 0 /* Not currently used, but may be needed in the future */
dd1a3ba7
KW
3151PERLVAR(I, seen_deprecated_macro, HV *)
3152
34aeb2e9
KW
3153STATIC void
3154S_warn_on_first_deprecated_use(pTHX_ const char * const name,
3155 const char * const alternative,
3156 const bool use_locale,
3157 const char * const file,
3158 const unsigned line)
3159{
3160 const char * key;
3161
3162 PERL_ARGS_ASSERT_WARN_ON_FIRST_DEPRECATED_USE;
3163
3164 if (ckWARN_d(WARN_DEPRECATED)) {
3165
3166 key = Perl_form(aTHX_ "%s;%d;%s;%d", name, use_locale, file, line);
3167 if (! hv_fetch(PL_seen_deprecated_macro, key, strlen(key), 0)) {
3168 if (! PL_seen_deprecated_macro) {
3169 PL_seen_deprecated_macro = newHV();
3170 }
3171 if (! hv_store(PL_seen_deprecated_macro, key,
3172 strlen(key), &PL_sv_undef, 0))
3173 {
3174 Perl_croak(aTHX_ "panic: hv_store() unexpectedly failed");
3175 }
3176
c44e9413 3177 if (instr(file, "mathoms.c")) {
607313a1 3178 Perl_warner(aTHX_ WARN_DEPRECATED,
5203d63d 3179 "In %s, line %d, starting in Perl v5.32, %s()"
607313a1
KW
3180 " will be removed. Avoid this message by"
3181 " converting to use %s().\n",
3182 file, line, name, alternative);
3183 }
3184 else {
34aeb2e9 3185 Perl_warner(aTHX_ WARN_DEPRECATED,
5203d63d 3186 "In %s, line %d, starting in Perl v5.32, %s() will"
34aeb2e9
KW
3187 " require an additional parameter. Avoid this"
3188 " message by converting to use %s().\n",
3189 file, line, name, alternative);
607313a1 3190 }
34aeb2e9
KW
3191 }
3192 }
3193}
059703b0 3194#endif
922e8cb4
KW
3195
3196bool
dd1a3ba7 3197Perl__is_utf8_FOO(pTHX_ const U8 classnum, const U8 *p, const U8 * const e)
da8c1a98 3198{
5fd49982 3199 dVAR;
dd1a3ba7 3200 PERL_ARGS_ASSERT__IS_UTF8_FOO;
da8c1a98 3201
dd1a3ba7 3202 return is_utf8_common(p, e, PL_XPosix_ptrs[classnum]);
da8c1a98
KW
3203}
3204
3205bool
dd1a3ba7 3206Perl__is_utf8_perl_idstart(pTHX_ const U8 *p, const U8 * const e)
da8c1a98 3207{
5fd49982 3208 dVAR;
dd1a3ba7 3209 PERL_ARGS_ASSERT__IS_UTF8_PERL_IDSTART;
da8c1a98 3210
dd1a3ba7 3211 return is_utf8_common(p, e, PL_utf8_perl_idstart);
da8c1a98
KW
3212}
3213
3214bool
dd1a3ba7 3215Perl__is_utf8_perl_idcont(pTHX_ const U8 *p, const U8 * const e)
c11ff943 3216{
5fd49982 3217 dVAR;
dd1a3ba7 3218 PERL_ARGS_ASSERT__IS_UTF8_PERL_IDCONT;
7dbf68d2 3219
dd1a3ba7 3220 return is_utf8_common(p, e, PL_utf8_perl_idcont);
7dbf68d2
KW
3221}
3222
6a4a25f4 3223STATIC UV
30613bdc
KW
3224S__to_utf8_case(pTHX_ const UV uv1, const U8 *p,
3225 U8* ustrp, STRLEN *lenp,
341bb5b7 3226 SV *invlist, const int * const invmap,
e39a4130 3227 const unsigned int * const * const aux_tables,
30613bdc
KW
3228 const U8 * const aux_table_lengths,
3229 const char * const normal)
b9992569 3230{
0134edef 3231 STRLEN len = 0;
7918f24d 3232
30613bdc
KW
3233 /* Change the case of code point 'uv1' whose UTF-8 representation (assumed
3234 * by this routine to be valid) begins at 'p'. 'normal' is a string to use
3235 * to name the new case in any generated messages, as a fallback if the
3236 * operation being used is not available. The new case is given by the
3237 * data structures in the remaining arguments.
3238 *
3239 * On return 'ustrp' points to '*lenp' UTF-8 encoded bytes representing the
3240 * entire changed case string, and the return value is the first code point
3241 * in that string */
3242
b9992569 3243 PERL_ARGS_ASSERT__TO_UTF8_CASE;
7918f24d 3244
36eaa811
KW
3245 /* For code points that don't change case, we already know that the output
3246 * of this function is the unchanged input, so we can skip doing look-ups
3247 * for them. Unfortunately the case-changing code points are scattered
3248 * around. But there are some long consecutive ranges where there are no
3249 * case changing code points. By adding tests, we can eliminate the lookup
3250 * for all the ones in such ranges. This is currently done here only for
3251 * just a few cases where the scripts are in common use in modern commerce
3252 * (and scripts adjacent to those which can be included without additional
3253 * tests). */
3254
3255 if (uv1 >= 0x0590) {
3256 /* This keeps from needing further processing the code points most
3257 * likely to be used in the following non-cased scripts: Hebrew,
3258 * Arabic, Syriac, Thaana, NKo, Samaritan, Mandaic, Devanagari,
3259 * Bengali, Gurmukhi, Gujarati, Oriya, Tamil, Telugu, Kannada,
3260 * Malayalam, Sinhala, Thai, Lao, Tibetan, Myanmar */
3261 if (uv1 < 0x10A0) {
3262 goto cases_to_self;
3263 }
3264
3265 /* The following largish code point ranges also don't have case
3266 * changes, but khw didn't think they warranted extra tests to speed
3267 * them up (which would slightly slow down everything else above them):
3268 * 1100..139F Hangul Jamo, Ethiopic
3269 * 1400..1CFF Unified Canadian Aboriginal Syllabics, Ogham, Runic,
3270 * Tagalog, Hanunoo, Buhid, Tagbanwa, Khmer, Mongolian,
3271 * Limbu, Tai Le, New Tai Lue, Buginese, Tai Tham,
3272 * Combining Diacritical Marks Extended, Balinese,
3273 * Sundanese, Batak, Lepcha, Ol Chiki
3274 * 2000..206F General Punctuation
3275 */
3276
3277 if (uv1 >= 0x2D30) {
3278
3279 /* This keeps the from needing further processing the code points
3280 * most likely to be used in the following non-cased major scripts:
3281 * CJK, Katakana, Hiragana, plus some less-likely scripts.
3282 *
3283 * (0x2D30 above might have to be changed to 2F00 in the unlikely
3284 * event that Unicode eventually allocates the unused block as of
3285 * v8.0 2FE0..2FEF to code points that are cased. khw has verified
3286 * that the test suite will start having failures to alert you
3287 * should that happen) */
3288 if (uv1 < 0xA640) {
3289 goto cases_to_self;
3290 }
3291
3292 if (uv1 >= 0xAC00) {
3293 if (UNLIKELY(UNICODE_IS_SURROGATE(uv1))) {
5af9bc97
KW
3294 if (ckWARN_d(WARN_SURROGATE)) {
3295 const char* desc = (PL_op) ? OP_DESC(PL_op) : normal;
3296 Perl_warner(aTHX_ packWARN(WARN_SURROGATE),
56576a04
KW
3297 "Operation \"%s\" returns its argument for"
3298 " UTF-16 surrogate U+%04" UVXf, desc, uv1);
5af9bc97
KW
3299 }
3300 goto cases_to_self;
3301 }
36eaa811
KW
3302
3303 /* AC00..FAFF Catches Hangul syllables and private use, plus
3304 * some others */
3305 if (uv1 < 0xFB00) {
3306 goto cases_to_self;
36eaa811
KW
3307 }
3308
5af9bc97 3309 if (UNLIKELY(UNICODE_IS_SUPER(uv1))) {
40606899 3310 if (UNLIKELY(uv1 > MAX_LEGAL_CP)) {
d22ec717 3311 Perl_croak(aTHX_ cp_above_legal_max, uv1,
40606899 3312 MAX_LEGAL_CP);
5af9bc97
KW
3313 }
3314 if (ckWARN_d(WARN_NON_UNICODE)) {
3315 const char* desc = (PL_op) ? OP_DESC(PL_op) : normal;
3316 Perl_warner(aTHX_ packWARN(WARN_NON_UNICODE),
56576a04
KW
3317 "Operation \"%s\" returns its argument for"
3318 " non-Unicode code point 0x%04" UVXf, desc, uv1);
5af9bc97
KW
3319 }
3320 goto cases_to_self;
3321 }
3bfc1e70
KW
3322#ifdef HIGHEST_CASE_CHANGING_CP_FOR_USE_ONLY_BY_UTF8_DOT_C
3323 if (UNLIKELY(uv1
3324 > HIGHEST_CASE_CHANGING_CP_FOR_USE_ONLY_BY_UTF8_DOT_C))
3325 {
3326
3bfc1e70
KW
3327 goto cases_to_self;
3328 }
3329#endif
36eaa811
KW
3330 }
3331 }
9ae3ac1a 3332
36eaa811 3333 /* Note that non-characters are perfectly legal, so no warning should
8946fcd9 3334 * be given. */
9ae3ac1a
KW
3335 }
3336
8946fcd9
KW
3337 {
3338 unsigned int i;
e39a4130 3339 const unsigned int * cp_list;
8946fcd9 3340 U8 * d;
69352d88
KW
3341
3342 /* 'index' is guaranteed to be non-negative, as this is an inversion
3343 * map that covers all possible inputs. See [perl #133365] */
8946fcd9
KW
3344 SSize_t index = _invlist_search(invlist, uv1);
3345 IV base = invmap[index];
0134edef 3346
30613bdc
KW
3347 /* The data structures are set up so that if 'base' is non-negative,
3348 * the case change is 1-to-1; and if 0, the change is to itself */
8946fcd9
KW
3349 if (base >= 0) {
3350 IV lc;
b08cf34e 3351
8946fcd9
KW
3352 if (base == 0) {
3353 goto cases_to_self;
4a8240a3 3354 }
4a8240a3 3355
30613bdc 3356 /* This computes, e.g. lc(H) as 'H - A + a', using the lc table */
8946fcd9
KW
3357 lc = base + uv1 - invlist_array(invlist)[index];
3358 *lenp = uvchr_to_utf8(ustrp, lc) - ustrp;
3359 return lc;
3360 }
1feea2c7 3361
30613bdc
KW
3362 /* Here 'base' is negative. That means the mapping is 1-to-many, and
3363 * requires an auxiliary table look up. abs(base) gives the index into
3364 * a list of such tables which points to the proper aux table. And a
3365 * parallel list gives the length of each corresponding aux table. */
8946fcd9 3366 cp_list = aux_tables[-base];
30613bdc
KW
3367
3368 /* Create the string of UTF-8 from the mapped-to code points */
8946fcd9
KW
3369 d = ustrp;
3370 for (i = 0; i < aux_table_lengths[-base]; i++) {
3371 d = uvchr_to_utf8(d, cp_list[i]);
cbe07460 3372 }
8946fcd9
KW
3373 *d = '\0';
3374 *lenp = d - ustrp;
3375
3376 return cp_list[0];
cbe07460
KW
3377 }
3378
3379 /* Here, there was no mapping defined, which means that the code point maps
3380 * to itself. Return the inputs */
e24dfe9c 3381 cases_to_self:
a13f1de4
KW
3382 if (p) {
3383 len = UTF8SKIP(p);
3384 if (p != ustrp) { /* Don't copy onto itself */
3385 Copy(p, ustrp, len, U8);
3386 }
3387 *lenp = len;
3388 }
3389 else {
3390 *lenp = uvchr_to_utf8(ustrp, uv1) - ustrp;
ca9fab46 3391 }
2a37f04d 3392
f4cd282c 3393 return uv1;
cbe07460 3394
a0ed51b3
LW
3395}
3396
b74fe592 3397Size_t
e39a4130
KW
3398Perl__inverse_folds(pTHX_ const UV cp, unsigned int * first_folds_to,
3399 const unsigned int ** remaining_folds_to)
b74fe592
KW
3400{
3401 /* Returns the count of the number of code points that fold to the input
3402 * 'cp' (besides itself).
3403 *
3404 * If the return is 0, there is nothing else that folds to it, and
3405 * '*first_folds_to' is set to 0, and '*remaining_folds_to' is set to NULL.
3406 *
3407 * If the return is 1, '*first_folds_to' is set to the single code point,
3408 * and '*remaining_folds_to' is set to NULL.
3409 *
3410 * Otherwise, '*first_folds_to' is set to a code point, and
3411 * '*remaining_fold_to' is set to an array that contains the others. The
3412 * length of this array is the returned count minus 1.
3413 *
3414 * The reason for this convolution is to avoid having to deal with
3415 * allocating and freeing memory. The lists are already constructed, so
3416 * the return can point to them, but single code points aren't, so would
3417 * need to be constructed if we didn't employ something like this API */
3418
1565c085 3419 dVAR;
69352d88
KW
3420 /* 'index' is guaranteed to be non-negative, as this is an inversion map
3421 * that covers all possible inputs. See [perl #133365] */
b74fe592
KW
3422 SSize_t index = _invlist_search(PL_utf8_foldclosures, cp);
3423 int base = _Perl_IVCF_invmap[index];
3424
3425 PERL_ARGS_ASSERT__INVERSE_FOLDS;
3426
3427 if (base == 0) { /* No fold */
3428 *first_folds_to = 0;
3429 *remaining_folds_to = NULL;
3430 return 0;
3431 }
3432
3433#ifndef HAS_IVCF_AUX_TABLES /* This Unicode version only has 1-1 folds */
3434
3435 assert(base > 0);
3436
3437#else
3438
3439 if (UNLIKELY(base < 0)) { /* Folds to more than one character */
3440
3441 /* The data structure is set up so that the absolute value of 'base' is
3442 * an index into a table of pointers to arrays, with the array
3443 * corresponding to the index being the list of code points that fold
3444 * to 'cp', and the parallel array containing the length of the list
3445 * array */
3446 *first_folds_to = IVCF_AUX_TABLE_ptrs[-base][0];
3447 *remaining_folds_to = IVCF_AUX_TABLE_ptrs[-base] + 1; /* +1 excludes
3448 *first_folds_to
3449 */
3450 return IVCF_AUX_TABLE_lengths[-base];
3451 }
3452
3453#endif
3454
3455 /* Only the single code point. This works like 'fc(G) = G - A + a' */
3456 *first_folds_to = base + cp - invlist_array(PL_utf8_foldclosures)[index];
3457 *remaining_folds_to = NULL;
3458 return 1;
3459}
3460
051a06d4 3461STATIC UV
56576a04
KW
3462S_check_locale_boundary_crossing(pTHX_ const U8* const p, const UV result,
3463 U8* const ustrp, STRLEN *lenp)
051a06d4 3464{
4a4088c4 3465 /* This is called when changing the case of a UTF-8-encoded character above
31f05a37
KW
3466 * the Latin1 range, and the operation is in a non-UTF-8 locale. If the
3467 * result contains a character that crosses the 255/256 boundary, disallow
3468 * the change, and return the original code point. See L<perlfunc/lc> for
3469 * why;
051a06d4 3470 *
a1433954
KW
3471 * p points to the original string whose case was changed; assumed
3472 * by this routine to be well-formed
051a06d4 3473 * result the code point of the first character in the changed-case string
56576a04
KW
3474 * ustrp points to the changed-case string (<result> represents its
3475 * first char)
051a06d4
KW
3476 * lenp points to the length of <ustrp> */
3477
3478 UV original; /* To store the first code point of <p> */
3479
3480 PERL_ARGS_ASSERT_CHECK_LOCALE_BOUNDARY_CROSSING;
3481
a4f12ed7 3482 assert(UTF8_IS_ABOVE_LATIN1(*p));
051a06d4
KW
3483
3484 /* We know immediately if the first character in the string crosses the
5e45c680 3485 * boundary, so can skip testing */
051a06d4
KW
3486 if (result > 255) {
3487
3488 /* Look at every character in the result; if any cross the
3489 * boundary, the whole thing is disallowed */
3490 U8* s = ustrp + UTF8SKIP(ustrp);
3491 U8* e = ustrp + *lenp;
3492 while (s < e) {
a4f12ed7 3493 if (! UTF8_IS_ABOVE_LATIN1(*s)) {
051a06d4
KW
3494 goto bad_crossing;
3495 }
3496 s += UTF8SKIP(s);
3497 }
3498
613abc6d
KW
3499 /* Here, no characters crossed, result is ok as-is, but we warn. */
3500 _CHECK_AND_OUTPUT_WIDE_LOCALE_UTF8_MSG(p, p + UTF8SKIP(p));
051a06d4
KW
3501 return result;
3502 }
3503
7b52d656 3504 bad_crossing:
051a06d4
KW
3505
3506 /* Failed, have to return the original */
4b88fb76 3507 original = valid_utf8_to_uvchr(p, lenp);
ab0b796c
KW
3508
3509 /* diag_listed_as: Can't do %s("%s") on non-UTF-8 locale; resolved to "%s". */
3510 Perl_ck_warner(aTHX_ packWARN(WARN_LOCALE),
56576a04
KW
3511 "Can't do %s(\"\\x{%" UVXf "}\") on non-UTF-8"
3512 " locale; resolved to \"\\x{%" UVXf "}\".",
357aadde 3513 OP_DESC(PL_op),
ab0b796c
KW
3514 original,
3515 original);
051a06d4
KW
3516 Copy(p, ustrp, *lenp, char);
3517 return original;
3518}
3519
b257a28c
KW
3520STATIC UV
3521S_turkic_fc(pTHX_ const U8 * const p, const U8 * const e,
3522 U8 * ustrp, STRLEN *lenp)
3523{
3524 /* Returns 0 if the foldcase of the input UTF-8 encoded sequence from
3525 * p0..e-1 according to Turkic rules is the same as for non-Turkic.
3526 * Otherwise, it returns the first code point of the Turkic foldcased
3527 * sequence, and the entire sequence will be stored in *ustrp. ustrp will
3528 * contain *lenp bytes
3529 *
3530 * Turkic differs only from non-Turkic in that 'i' and LATIN CAPITAL LETTER
3531 * I WITH DOT ABOVE form a case pair, as do 'I' and LATIN SMALL LETTER
3532 * DOTLESS I */
3533
3534 PERL_ARGS_ASSERT_TURKIC_FC;
3535 assert(e > p);
3536
3537 if (UNLIKELY(*p == 'I')) {
3538 *lenp = 2;
3539 ustrp[0] = UTF8_TWO_BYTE_HI(LATIN_SMALL_LETTER_DOTLESS_I);
3540 ustrp[1] = UTF8_TWO_BYTE_LO(LATIN_SMALL_LETTER_DOTLESS_I);
3541 return LATIN_SMALL_LETTER_DOTLESS_I;
3542 }
3543
3544 if (UNLIKELY(memBEGINs(p, e - p,
3545 LATIN_CAPITAL_LETTER_I_WITH_DOT_ABOVE_UTF8)))
3546 {
3547 *lenp = 1;
3548 *ustrp = 'i';
3549 return 'i';
3550 }
3551
3552 return 0;
3553}
3554
3555STATIC UV
3556S_turkic_lc(pTHX_ const U8 * const p0, const U8 * const e,
3557 U8 * ustrp, STRLEN *lenp)
3558{
3559 /* Returns 0 if the lowercase of the input UTF-8 encoded sequence from
3560 * p0..e-1 according to Turkic rules is the same as for non-Turkic.
3561 * Otherwise, it returns the first code point of the Turkic lowercased
3562 * sequence, and the entire sequence will be stored in *ustrp. ustrp will
3563 * contain *lenp bytes */
3564
1565c085 3565 dVAR;
b257a28c
KW
3566 PERL_ARGS_ASSERT_TURKIC_LC;
3567 assert(e > p0);
3568
3569 /* A 'I' requires context as to what to do */
3570 if (UNLIKELY(*p0 == 'I')) {
3571 const U8 * p = p0 + 1;
3572
3573 /* According to the Unicode SpecialCasing.txt file, a capital 'I'
3574 * modified by a dot above lowercases to 'i' even in turkic locales. */
3575 while (p < e) {
3576 UV cp;
3577
3578 if (memBEGINs(p, e - p, COMBINING_DOT_ABOVE_UTF8)) {
3579 ustrp[0] = 'i';
3580 *lenp = 1;
3581 return 'i';
3582 }
3583
3584 /* For the dot above to modify the 'I', it must be part of a
3585 * combining sequence immediately following the 'I', and no other
3586 * modifier with a ccc of 230 may intervene */
3587 cp = utf8_to_uvchr_buf(p, e, NULL);
3588 if (! _invlist_contains_cp(PL_CCC_non0_non230, cp)) {
3589 break;
3590 }
3591
3592 /* Here the combining sequence continues */
3593 p += UTF8SKIP(p);
3594 }
3595 }
3596
3597 /* In all other cases the lc is the same as the fold */
3598 return turkic_fc(p0, e, ustrp, lenp);
3599}
3600
3601STATIC UV
3602S_turkic_uc(pTHX_ const U8 * const p, const U8 * const e,
3603 U8 * ustrp, STRLEN *lenp)
3604{
3605 /* Returns 0 if the upper or title-case of the input UTF-8 encoded sequence
3606 * from p0..e-1 according to Turkic rules is the same as for non-Turkic.
3607 * Otherwise, it returns the first code point of the Turkic upper or
3608 * title-cased sequence, and the entire sequence will be stored in *ustrp.
3609 * ustrp will contain *lenp bytes
3610 *
3611 * Turkic differs only from non-Turkic in that 'i' and LATIN CAPITAL LETTER
3612 * I WITH DOT ABOVE form a case pair, as do 'I' and and LATIN SMALL LETTER
3613 * DOTLESS I */
3614
3615 PERL_ARGS_ASSERT_TURKIC_UC;
3616 assert(e > p);
3617
3618 if (*p == 'i') {
3619 *lenp = 2;
3620 ustrp[0] = UTF8_TWO_BYTE_HI(LATIN_CAPITAL_LETTER_I_WITH_DOT_ABOVE);
3621 ustrp[1] = UTF8_TWO_BYTE_LO(LATIN_CAPITAL_LETTER_I_WITH_DOT_ABOVE);
3622 return LATIN_CAPITAL_LETTER_I_WITH_DOT_ABOVE;
3623 }
3624
3625 if (memBEGINs(p, e - p, LATIN_SMALL_LETTER_DOTLESS_I_UTF8)) {
3626 *lenp = 1;
3627 *ustrp = 'I';
3628 return 'I';
3629 }
3630
3631 return 0;
3632}
3633
eaf412bf
KW
3634/* The process for changing the case is essentially the same for the four case
3635 * change types, except there are complications for folding. Otherwise the
3636 * difference is only which case to change to. To make sure that they all do
3637 * the same thing, the bodies of the functions are extracted out into the
3638 * following two macros. The functions are written with the same variable
3639 * names, and these are known and used inside these macros. It would be
3640 * better, of course, to have inline functions to do it, but since different
3641 * macros are called, depending on which case is being changed to, this is not
3642 * feasible in C (to khw's knowledge). Two macros are created so that the fold
3643 * function can start with the common start macro, then finish with its special
3644 * handling; while the other three cases can just use the common end macro.
3645 *
3646 * The algorithm is to use the proper (passed in) macro or function to change
3647 * the case for code points that are below 256. The macro is used if using
3648 * locale rules for the case change; the function if not. If the code point is
3649 * above 255, it is computed from the input UTF-8, and another macro is called
3650 * to do the conversion. If necessary, the output is converted to UTF-8. If
3651 * using a locale, we have to check that the change did not cross the 255/256
3652 * boundary, see check_locale_boundary_crossing() for further details.
3653 *
3654 * The macros are split with the correct case change for the below-256 case
3655 * stored into 'result', and in the middle of an else clause for the above-255
3656 * case. At that point in the 'else', 'result' is not the final result, but is
3657 * the input code point calculated from the UTF-8. The fold code needs to
3658 * realize all this and take it from there.
3659 *
b257a28c
KW
3660 * To deal with Turkic locales, the function specified by the parameter
3661 * 'turkic' is called when appropriate.
3662 *
eaf412bf
KW
3663 * If you read the two macros as sequential, it's easier to understand what's
3664 * going on. */
3665#define CASE_CHANGE_BODY_START(locale_flags, LC_L1_change_macro, L1_func, \
b257a28c 3666 L1_func_extra_param, turkic) \
a239b1e2 3667 \
eaf412bf 3668 if (flags & (locale_flags)) { \
8b7358b9 3669 _CHECK_AND_WARN_PROBLEMATIC_LOCALE; \
eaf412bf 3670 if (IN_UTF8_CTYPE_LOCALE) { \
b257a28c
KW
3671 if (UNLIKELY(PL_in_utf8_turkic_locale)) { \
3672 UV ret = turkic(p, e, ustrp, lenp); \
3673 if (ret) return ret; \
3674 } \
3675 \
3676 /* Otherwise, treat a UTF-8 locale as not being in locale at \
3677 * all */ \
eaf412bf
KW
3678 flags &= ~(locale_flags); \
3679 } \
eaf412bf
KW
3680 } \
3681 \
3682 if (UTF8_IS_INVARIANT(*p)) { \
3683 if (flags & (locale_flags)) { \
3684 result = LC_L1_change_macro(*p); \
3685 } \
3686 else { \
3687 return L1_func(*p, ustrp, lenp, L1_func_extra_param); \
3688 } \
3689 } \
a239b1e2 3690 else if UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, e) { \
1a751160 3691 U8 c = EIGHT_BIT_UTF8_TO_NATIVE(*p, *(p+1)); \
eaf412bf 3692 if (flags & (locale_flags)) { \
1a751160 3693 result = LC_L1_change_macro(c); \
eaf412bf
KW
3694 } \
3695 else { \
1a751160 3696 return L1_func(c, ustrp, lenp, L1_func_extra_param); \
eaf412bf
KW
3697 } \
3698 } \
fa8ab374
KW
3699 else { /* malformed UTF-8 or ord above 255 */ \
3700 STRLEN len_result; \
fa8ab374
KW
3701 result = utf8n_to_uvchr(p, e - p, &len_result, UTF8_CHECK_ONLY); \
3702 if (len_result == (STRLEN) -1) { \
059703b0 3703 _force_out_malformed_utf8_message(p, e, 0, 1 /* Die */ ); \
fa8ab374 3704 }
eaf412bf
KW
3705
3706#define CASE_CHANGE_BODY_END(locale_flags, change_macro) \
3707 result = change_macro(result, p, ustrp, lenp); \
3708 \
3709 if (flags & (locale_flags)) { \
3710 result = check_locale_boundary_crossing(p, result, ustrp, lenp); \
3711 } \
3712 return result; \
3713 } \
3714 \
3715 /* Here, used locale rules. Convert back to UTF-8 */ \
3716 if (UTF8_IS_INVARIANT(result)) { \
3717 *ustrp = (U8) result; \
3718 *lenp = 1; \