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Revision 418 - (hide annotations) (download)
Fri Apr 24 09:17:18 2009 UTC (5 years, 11 months ago) by ph10
File size: 165868 byte(s)
Fix POSIX error code bug.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 418 Version 8.00 ??-???-??
5     ----------------------
7     1. The table for translating pcre_compile() error codes into POSIX error codes
8     was out-of-date, and there was no check on the pcre_compile() error code
9     being within the table. This could lead to an OK return being given in
10     error.
13 ph10 412 Version 7.9 11-Apr-09
14 ph10 376 ---------------------
16 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
17 ph10 376 (pcretest), all targets were linked against these libraries. This included
18     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
19     libraries. This caused unwanted dependencies to be created. This problem
20 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
21 ph10 376 pcretest is linked with readline.
22 ph10 392
23 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
24     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
25     moved outside it again, because FALSE and TRUE are already defined in AIX,
26     but BOOL is not.
27 ph10 392
28     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
29 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
30 ph10 392
31 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
32     hyphens) following file names and line numbers when outputting matching
33 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
34 ph10 376 wording for the --colour (or --color) option.
35 ph10 392
36 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
37     was not coloured; this is different to GNU grep, so I have changed it to be
38     the same.
39 ph10 392
40 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
41 ph10 392 each matching line was coloured. Now it goes on to look for further matches
42     of any of the test patterns, which is the same behaviour as GNU grep.
44     7. A pattern that could match an empty string could cause pcregrep to loop; it
45     doesn't make sense to accept an empty string match in pcregrep, so I have
46 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
47     seems to be how GNU grep behaves.
48 ph10 392
49 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
50 ph10 392 start or after a newline", because the conditional assertion was not being
51     correctly handled. The rule now is that both the assertion and what follows
52     in the first alternative must satisfy the test.
54 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
55 ph10 399 condition was an assertion, PCRE could crash during matching, both with
56     pcre_exec() and pcre_dfa_exec().
57 ph10 392
58     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
59     used for matching.
61     11. Unicode property support in character classes was not working for
62 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
63 ph10 388
64 ph10 392 12. Added the -M command line option to pcretest.
66 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
67 ph10 389
68     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
69 ph10 390
70 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
71 ph10 390 wrapper.
72 ph10 392
73 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
74 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
75 ph10 391 string constants.
76 ph10 405
77 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
78     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
79 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
80     these, but not everybody uses configure.
82     19. A conditional group that had only one branch was not being correctly
83     recognized as an item that could match an empty string. This meant that an
84     enclosing group might also not be so recognized, causing infinite looping
85     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
86     with the subject "ab", where knowledge that the repeated group can match
87 ph10 396 nothing is needed in order to break the loop.
88 ph10 405
89 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
90 ph10 405 exec(), but without supplying a callout function, matching went wrong.
92     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
93     leak if the size of the offset vector was greater than 30. When the vector
94     is smaller, the saved offsets during recursion go onto a local stack
95     vector, but for larger vectors malloc() is used. It was failing to free
96     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
97 ph10 400 error, in fact).
98 ph10 405
99 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
100 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
101     problem, but was untidy.
102 ph10 376
103 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
104     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
105     included within another project.
106 ph10 411
107 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
108     slightly modified by me:
109 ph10 411
110     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
111     not building pcregrep.
113 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
114 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
116 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
117     duplicate group numbers, could behave incorrectly or give incorrect errors,
118     because when scanning forward to find the reference group, PCRE was not
119     taking into account the duplicate group numbers. A pattern such as
120     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
121 ph10 411
122     26. Changed a few more instances of "const unsigned char *" to USPTR, making
123     the feature of a custom pointer more persuasive (as requested by a user).
124 ph10 416
125 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
126 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
127     pre-defined.
128 ph10 392
129 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
131 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
132     in the configuration summary.
133 ph10 405
134 ph10 411
135 ph10 374 Version 7.8 05-Sep-08
136 ph10 349 ---------------------
138     1. Replaced UCP searching code with optimized version as implemented for Ad
139     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
140 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
141     to 5 times on some simple patterns that I tested. Permission was given to
142     distribute the MultiStage2.py script that generates the tables (it's not in
143     the tarball, but is in the Subversion repository).
144 ph10 349
145 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
146     scripts.
147 ph10 358
148 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
149     a group with a zero qualifier. The result of the study could be incorrect,
150 ph10 358 or the function might crash, depending on the pattern.
152     4. Caseless matching was not working for non-ASCII characters in back
153 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
154 ph10 358 It now works when Unicode Property Support is available.
156 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
157     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
158     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
159 ph10 358 truncation.
160 ph10 349
161 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
163 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
164     pointers, in case they are 64-bit values.
165 ph10 371
166     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
167     test 2 if it fails.
169 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
170 ph10 371 and a #define of that name to empty if it is not externally set. This is to
171     allow users of MSVC to set it if necessary.
173     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
174 ph10 359 the convenience functions in the pcre_get.c source file.
175 ph10 371
176 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
177     could cause overwriting and/or a crash. This command provoked a crash in
178 ph10 371 some environments:
180     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
182 ph10 360 This potential security problem was recorded as CVE-2008-2371.
183 ph10 371
184 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
185     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
186 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
187 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
188     pcretest so that it places the subject at the end of its malloc-ed buffer.
189 ph10 371
190 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
191 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
193 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
194 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
195     first line. This applied both to normal and DFA matching.
197 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
198 ph10 371 /^[^d]*?$/8 failed to match "abc".
199 ph10 351
200 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
202     17. Make it more clear in the documentation that values returned from
203 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
204 ph10 357
205 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
206 ph10 368
207 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
208     supplied by Stefan Weber. I made a further small update for 7.8 because
209 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
210     replaced by pcre_ucd.c.
211 ph10 371
212 ph10 373
213 ph10 347 Version 7.7 07-May-08
214 ph10 321 ---------------------
216     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
217 ph10 345 a string to a long long, pretend we don't even have a long long." This is
218 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
219 ph10 345
220 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
221     pre-7.6 versions, which defined a global no_arg variable instead of putting
222 ph10 332 it in the RE class. (See also #8 below.)
223 ph10 345
224     3. Remove a line of dead code, identified by coverity and reported by Nuno
225     Lopes.
227 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
228 ph10 321
229 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
230 ph10 345 of files, instead of just to the final components.
232 ph10 324 (2) If there was more than one level of directory, the subdirectories were
233     skipped unless they satisfied the include/exclude conditions. This is
234     inconsistent with GNU grep (and could even be seen as contrary to the
235     pcregrep specification - which I improved to make it absolutely clear).
236     The action now is always to scan all levels of directory, and just
237     apply the include/exclude patterns to regular files.
238 ph10 345
239 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
240 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
242 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
243 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
244 ph10 326 doesn't support NULs in patterns.
245 ph10 345
246     7. Added some missing "const"s to declarations of static tables in
247     pcre_compile.c and pcre_dfa_exec.c.
249 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
250 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
251 ph10 345 first patch. And a third patch - this was a messy problem.)
252 ph10 321
253 ph10 345 9. Applied Craig's patch to remove the use of push_back().
255 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
256     matching function regexec().
257 ph10 345
258     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
259     which, however, unlike Perl's \g{...}, are subroutine calls, not back
260 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
261     Oniguruma does).
262 ph10 345
263     12. Previously, a group with a zero repeat such as (...){0} was completely
264 ph10 335 omitted from the compiled regex. However, this means that if the group
265     was called as a subroutine from elsewhere in the pattern, things went wrong
266 ph10 345 (an internal error was given). Such groups are now left in the compiled
267     pattern, with a new opcode that causes them to be skipped at execution
268 ph10 335 time.
269 ph10 345
270 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
271     to the way PCRE behaves:
272 ph10 345
273 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
274 ph10 345
275     (b) A back reference to an unmatched subpattern matches an empty string
276 ph10 336 (Perl fails the current match path).
277 ph10 345
278 ph10 341 (c) A data ] in a character class must be notated as \] because if the
279 ph10 345 first data character in a class is ], it defines an empty class. (In
280 ph10 341 Perl it is not possible to have an empty class.) The empty class []
281     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
282     The negative empty class [^] matches any one character, independently
283     of the DOTALL setting.
284 ph10 345
285     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
286 ph10 340 non-existent subpattern following a character class starting with ']' and
287     containing () gave an internal compiling error instead of "reference to
288     non-existent subpattern". Fortunately, when the pattern did exist, the
289 ph10 345 compiled code was correct. (When scanning forwards to check for the
290 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
291 ph10 345 the class, so got the count wrong. When actually compiling, the reference
292 ph10 340 was subsequently set up correctly.)
293 ph10 345
294 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
295 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
296     other assertions are supported. I have made pcre_dfa_exec() support
297     (*FAIL).
299 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
300 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
301     cannot be changed at match time, I realized I could make a small
302     improvement to matching performance by compiling OP_ALLANY instead of
303     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
304     on the OP_ANY path.
306     17. Compiling pcretest on Windows with readline support failed without the
307 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
308 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
310 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
311 ph10 345 ncurses library to be included for pcretest when ReadLine support is
312     requested, but also to allow for it to be overridden. This patch came from
313     Daniel Bergström.
314 ph10 347
315 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
316 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
317     any errors with the current Unicode tables. Thanks to Peter Kankowski for
318     spotting this.
319 ph10 324
320 ph10 332
321 ph10 319 Version 7.6 28-Jan-08
322 ph10 300 ---------------------
324 ph10 302 1. A character class containing a very large number of characters with
325     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
326     overflow.
327 ph10 309
328     2. Patch to cut out the "long long" test in pcrecpp_unittest when
329     HAVE_LONG_LONG is not defined.
331 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
332 ph10 304 bring them up to date and include new features. This patch includes:
333 ph10 309
334 ph10 304 - Fixed PH's badly added libz and libbz2 support.
335     - Fixed a problem with static linking.
336 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
337 ph10 304 - Fixed dftables problem and added an option.
338     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
340     - Added readline support for pcretest.
341 ph10 309 - Added an listing of the option settings after cmake has run.
343 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
344     "pcre.dll" under mingw when using Configure/Make. I added stuff to
345     Makefile.am that cause it to include this special target, without
346     affecting anything else. Note that the same mingw target plus all
347     the other distribution libraries and programs are now supported
348     when configuring with CMake (see 6 below) instead of with
349     Configure/Make.
350 ph10 309
351 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
352     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
353 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
354     solves the problem, but it does no harm.
355 ph10 313
356 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
357 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
358 ph10 314 with CMake, and also correct the comment about stack recursion.
359 ph10 313
360 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
361 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
362     of a program that users should build themselves after PCRE is installed, so
363     building it automatically is not really right. What is more, it gave
364 ph10 312 trouble in some build environments.
365 ph10 300
366 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
367 ph10 308
368 ph10 319
369 ph10 298 Version 7.5 10-Jan-08
370 ph10 263 ---------------------
372     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
373     values in parens when parsing an RE using the C++ wrapper."
374 ph10 286
375 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
376     Characters greater than 255 were excluded from the class instead of being
377     included.
378 ph10 286
379     3. The same bug as (2) above applied to negated POSIX classes such as
380 ph10 265 [:^space:].
381 ph10 286
382 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
383     defined or documented. It seems to have been a typo for PCRE_STATIC, so
384 ph10 286 I have changed it.
386 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
387 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
388     first named subpattern whose name started with "a" (in other words, the
389 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
390     expected" is now given for (?&) (a zero-length name), and this patch also
391     makes it give the same error for \k'' (previously it complained that that
392     was a reference to a non-existent subpattern).
393 ph10 286
394 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
395 ph10 286 this is right because (?- can be followed by option settings as well as by
396 ph10 269 digits. I have, however, made the messages clearer.
397 ph10 286
398 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
399     than the number used in the conditional) now cause a compile-time error.
400     This is actually not compatible with Perl, which accepts such patterns, but
401     treats the conditional as always being FALSE (as PCRE used to), but it
402     seems to me that giving a diagnostic is better.
403 ph10 286
404 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
405 ph10 275 and messages.
406 ph10 286
407     9. Fix two occurrences of "backslash" in comments that should have been
408     "backspace".
410     10. Remove two redundant lines of code that can never be obeyed (their function
411     was moved elsewhere).
413     11. The program that makes PCRE's Unicode character property table had a bug
414     which caused it to generate incorrect table entries for sequences of
415 ph10 277 characters that have the same character type, but are in different scripts.
416 ph10 286 It amalgamated them into a single range, with the script of the first of
417 ph10 277 them. In other words, some characters were in the wrong script. There were
418     thirteen such cases, affecting characters in the following ranges:
419 ph10 286
420 ph10 277 U+002b0 - U+002c1
421     U+0060c - U+0060d
422 ph10 286 U+0061e - U+00612
423 ph10 277 U+0064b - U+0065e
424     U+0074d - U+0076d
425     U+01800 - U+01805
426     U+01d00 - U+01d77
427     U+01d9b - U+01dbf
428     U+0200b - U+0200f
429     U+030fc - U+030fe
430     U+03260 - U+0327f
431     U+0fb46 - U+0fbb1
432     U+10450 - U+1049d
433 ph10 286
434 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
435     compatible with GNU grep in that, if there was more than one match in a
436     line, it showed only the first of them. It now behaves in the same way as
437     GNU grep.
438 ph10 286
439     13. If the -o and -v options were combined for pcregrep, it printed a blank
440     line for every non-matching line. GNU grep prints nothing, and pcregrep now
441     does the same. The return code can be used to tell if there were any
442     non-matching lines.
444 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
446     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
447 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
448 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
449     and both kinds of lookbehind were skipped).
451 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
452 ph10 284 inclusion of <windows.h> to before rather than after the definition of
453     INVALID_FILE_ATTRIBUTES (patch from David Byron).
454 ph10 263
455 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
456 ph10 286 character property caused pcre_compile() to compile bad code, which led at
457     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
458     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
459     caused the error; without that there was no problem.
460 ph10 263
461 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
462 ph10 286
463 ph10 289 19. Added --enable-pcretest-libreadline.
464 ph10 286
465 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
466 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
467 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
468     later patch that removed the other one (the right fix) and added unit tests
469     that check the return values (which was not done before).
470 ph10 292
471 ph10 291 21. Several CMake things:
472 ph10 287
473 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
474 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
475 ph10 288
476 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
477     linked with the newly-built libraries, not previously installed ones.
478 ph10 291
480 ph10 298
481     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
482     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
483     UTF-8 newline character). The key issue is that the pattern starts .*;
484     this means that the match must be either at the beginning, or after a
485     newline. The bug was in the code for advancing after a failed match and
486     checking that the new position followed a newline. It was not taking
487 ph10 294 account of UTF-8 characters correctly.
488 ph10 298
489     23. PCRE was behaving differently from Perl in the way it recognized POSIX
490     character classes. PCRE was not treating the sequence [:...:] as a
491     character class unless the ... were all letters. Perl, however, seems to
492     allow any characters between [: and :], though of course it rejects as
493     unknown any "names" that contain non-letters, because all the known class
494     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
495     for example, whereas PCRE did not - it did not recognize a POSIX character
496     class. This seemed a bit dangerous, so the code has been changed to be
497     closer to Perl. The behaviour is not identical to Perl, because PCRE will
498     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
499     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
500     Perl does, and where it didn't before.
502 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
503     Windows environments %n is disabled by default.
504 ph10 292
506 ph10 260 Version 7.4 21-Sep-07
507 ph10 230 ---------------------
509     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
510 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
511     LF". That isn't really right - the whole point of the change was to try to
512     help when there was an actual mention of one of the two characters. So now
513     the change happens only if \r or \n (or a literal CR or LF) character is
514 ph10 230 encountered.
515 ph10 231
516     2. The 32-bit options word was also used for 6 internal flags, but the numbers
517     of both had grown to the point where there were only 3 bits left.
518     Fortunately, there was spare space in the data structure, and so I have
519     moved the internal flags into a new 16-bit field to free up more option
520 ph10 230 bits.
521 ph10 231
522     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
523     but did not set the internal JCHANGED flag - either of these is enough to
524     control the way the "get" function works - but the PCRE_INFO_JCHANGED
525     facility is supposed to tell if (?J) was ever used, so now (?J) at the
526 ph10 230 start sets both bits.
528 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
529     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
530 ph10 230
531 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
533     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
534 ph10 233 compatibility, even though it is no longer used.
535 ph10 243
536     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
537 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
538 ph10 259 windows.h file is present (where different names are used). [This was
539 ph10 257 reversed later after testing - see 16 below.]
540 ph10 243
541     8. Changed all #include <config.h> to #include "config.h". There were also
542 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
543 ph10 243
544 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
545 ph10 243 sequence off the lines that it output.
547     10. It was pointed out to me that arrays of string pointers cause lots of
548     relocations when a shared library is dynamically loaded. A technique of
549     using a single long string with a table of offsets can drastically reduce
550     these. I have refactored PCRE in four places to do this. The result is
551 ph10 240 dramatic:
552 ph10 243
553 ph10 240 Originally: 290
554     After changing UCP table: 187
555 ph10 243 After changing error message table: 43
556 ph10 240 After changing table of "verbs" 36
557     After changing table of Posix names 22
558 ph10 243
559 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
560 ph10 247
561 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
562 ph10 247 unicode-properties was also set.
564 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
565 ph10 231
566 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
567     checked only for CRLF.
568 ph10 233
569 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
571 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
572 ph10 253
573 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
574 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
575     entirely. This removes changes made in 7 above.
576 ph10 256
577 ph10 261 17. The CMake files have been updated, and there is now more information about
578     building with CMake in the NON-UNIX-USE document.
579 ph10 257
580 ph10 261
581 ph10 228 Version 7.3 28-Aug-07
582 ph10 157 ---------------------
584 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
585     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
586     brackets there is not right, since it causes compilers to look for an
587     installed pcre.h, not the version that is in the source that is being
588     compiled (which of course may be different). I have changed it back to:
589 ph10 197
590 ph10 189 #include "pcre.h"
591 ph10 197
592     I have a vague recollection that the change was concerned with compiling in
593     different directories, but in the new build system, that is taken care of
594     by the VPATH setting the Makefile.
596 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
597     when the subject happened to end in the byte 0x85 (e.g. if the last
598     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
599     characters but of course it shouldn't be taken as a newline when it is part
600     of another character. The bug was that, for an unlimited repeat of . in
601     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
602     characters when looking for a newline.
603 ph10 197
604     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
606     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
607     in debug output.
609 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
610     long printing in the pcrecpp unittest when running under MinGW.
611 ph10 189
612 ph10 197 6. ESC_K was left out of the EBCDIC table.
613 ph10 189
614 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
615     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
616     limit also applies to "virtual nesting" when a pattern is recursive, and in
617     this case 1000 isn't so big. I have been able to remove this limit at the
618     expense of backing off one optimization in certain circumstances. Normally,
619     when pcre_exec() would call its internal match() function recursively and
620     immediately return the result unconditionally, it uses a "tail recursion"
621     feature to save stack. However, when a subpattern that can match an empty
622     string has an unlimited repetition quantifier, it no longer makes this
623     optimization. That gives it a stack frame in which to save the data for
624     checking that an empty string has been matched. Previously this was taken
625     from the 1000-entry workspace that had been reserved. So now there is no
626     explicit limit, but more stack is used.
627 ph10 189
628 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
629     syntax that is required for Windows, and which was going wrong for the
630     pcreposix and pcrecpp parts of the library. These were overlooked when this
631     problem was solved for the main library.
632 ph10 197
633 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
634     the size of patterns that contain repeated groups with explicit upper
635     limits. As the maximum quantifier is 65535, the maximum group length was
636     set at 30,000 so that the product of these two numbers did not overflow a
637     32-bit integer. However, it turns out that people want to use groups that
638     are longer than 30,000 bytes (though not repeat them that many times).
639     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
640     made it possible to implement the integer overflow checks in a much more
641     dynamic way, which I have now done. The artificial limitation on group
642     length has been removed - we now have only the limit on the total length of
643     the compiled pattern, which depends on the LINK_SIZE setting.
644 ph10 208
645     10. Fixed a bug in the documentation for get/copy named substring when
646     duplicate names are permitted. If none of the named substrings are set, the
647     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
648     empty string.
650     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
651     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
652     because the ] is interpreted as the first data character and the
653     terminating ] is not found. PCRE has been made compatible with Perl in this
654     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
655     cause memory overwriting.
657 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
658     string has been matched (to stop an infinite loop). It was not recognizing
659 ph10 208 a conditional subpattern that could match an empty string if that
660 ph10 206 subpattern was within another subpattern. For example, it looped when
661 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
662 ph10 206 condition was not nested. This bug has been fixed.
663 ph10 208
664 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
665     past the start of the subject in the presence of bytes with the top bit
666     set, for example "\x8aBCD".
667 ph10 211
668 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
669     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
670 ph10 200
671 ph10 211 14. Optimized (?!) to (*FAIL).
672 ph10 202
673 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
674     This restricts code points to be within the range 0 to 0x10FFFF, excluding
675     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
676     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
677     does: it's just the validity check that is more restrictive.
678 ph10 220
679     16. Inserted checks for integer overflows during escape sequence (backslash)
680     processing, and also fixed erroneous offset values for syntax errors during
681     backslash processing.
683 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
684 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
686 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
687     caused an overrun.
688 ph10 220
689     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
690     something other than just ASCII characters) inside a group that had an
691     unlimited repeat caused a loop at compile time (while checking to see
692     whether the group could match an empty string).
694 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
695     [\P{Any}] did so. (Error in the code for printing property names.)
696 ph10 210
697 ph10 220 21. An orphan \E inside a character class could cause a crash.
699     22. A repeated capturing bracket such as (A)? could cause a wild memory
700 ph10 218 reference during compilation.
701 ph10 220
702     23. There are several functions in pcre_compile() that scan along a compiled
703     expression for various reasons (e.g. to see if it's fixed length for look
704 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
705 ph10 220 present in the pattern. These operators have additional parameters compared
706     with \d, etc, and these were not being taken into account when moving along
707 ph10 218 the compiled data. Specifically:
708 ph10 220
709     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
710     length.
712     (b) An item such as \pL+ within a repeated group could cause crashes or
713 ph10 218 loops.
714 ph10 220
715 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
716 ph10 220 "reference to non-existent subpattern" error.
718 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
720 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
721 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
722 ph10 211
723 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
724 ph10 218
725 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
726 ph10 223 character were causing crashes (broken optimization).
727 ph10 227
728 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
729 ph10 227 \p or \P) caused a compile-time loop.
731 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
732     break. For example, the unstudied pattern [\r\n]A does not match the string
733     "\r\nA" because change 7.0/46 below moves the current point on by two
734     characters after failing to match at the start. However, the pattern \nA
735 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
736     the same is true. There doesn't seem any very clean way out of this, but
737     what I have chosen to do makes the common cases work: PCRE now takes note
738     of whether there can be an explicit match for \r or \n anywhere in the
739     pattern, and if so, 7.0/46 no longer applies. As part of this change,
740     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
741     pattern has explicit CR or LF references.
742 ph10 222
743 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
744 ph10 223
745 ph10 227
746 ph10 189 Version 7.2 19-Jun-07
747     ---------------------
749 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
750     which is apparently normally available under Windows.
751 ph10 159
752     2. Re-jig the pcregrep tests with different newline settings in an attempt
753     to make them independent of the local environment's newline setting.
754 ph10 157
755 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
756 ph10 165
757 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
758     was not 2, because the output contained actual offsets. The recent new
759 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
760     usable with all link sizes.
762 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
763     stack recursion. This gives a massive performance boost under BSD, but just
764 ph10 165 a small improvement under Linux. However, it saves one field in the frame
765 ph10 164 in all cases.
766 ph10 172
767 ph10 166 6. Added more features from the forthcoming Perl 5.10:
768 ph10 172
769 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
770     recursion call. It refers to the nth most recently opened parentheses.
771 ph10 172
772 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
773 ph10 172 to be opened parentheses.
775     (c) Conditions that refer to capturing parentheses can be specified
776 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
777 ph10 172
778 ph10 168 (d) \K resets the start of the current match so that everything before
779 ph10 172 is not part of it.
781 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
782 ph10 172
783 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
784 ph10 172 reference syntax.
785 ph10 182
786 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
787 ph10 182 alternative starts with the same number.
788 ph10 172
789 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
791 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
794     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
795     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
796 ph10 170 for detecting groups that can match an empty string.
797 ph10 159
798 ph10 172 9. A pattern with a very large number of alternatives (more than several
799     hundred) was running out of internal workspace during the pre-compile
800     phase, where pcre_compile() figures out how much memory will be needed. A
801     bit of new cunning has reduced the workspace needed for groups with
802     alternatives. The 1000-alternative test pattern now uses 12 bytes of
803     workspace instead of running out of the 4096 that are available.
804 ph10 182
805 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
806 ph10 172
807 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
808     The report of the bug said:
809 ph10 182
810 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
811     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
812 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
813 ph10 185
814 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
815 ph10 185 it matched the wrong number of bytes.
816 ph10 172
817 ph10 179
818 ph10 155 Version 7.1 24-Apr-07
819 ph10 98 ---------------------
821 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
822 ph10 122 that is more "standard", making use of automake and other Autotools. There
823 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
824     on this.
825 ph10 111
826     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
827     for recursive directory scanning broke on some systems because the files
828     are not scanned in any specific order and on different systems the order
829     was different. A call to "sort" has been inserted into RunGrepTest for the
830     approprate test as a short-term fix. In the longer term there may be an
831 ph10 100 alternative.
832 ph10 111
833 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
834 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
835     people do their own conversions for various reasons). The problems
836     concerned the use of low-level troff macros .br and .in. I have therefore
837     removed all such uses from the man pages (some were redundant, some could
838 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
839     HTML has been updated to handle .nf/.fi and to complain if it encounters
840     .br or .in.
841 ph10 111
842 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
843 ph10 123 arranged for config.h to be included in the distribution, with the name
844 ph10 111 config.h.generic, for the benefit of those who have to compile without
845     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
847     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
848     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
849 ph10 127 makevp.bat for the current PCRE, using the additional files
850 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
851 ph10 111
852     6. A Windows user reported a minor discrepancy with test 2, which turned out
853     to be caused by a trailing space on an input line that had got lost in his
854 ph10 102 copy. The trailing space was an accident, so I've just removed it.
855 ph10 111
856 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
857 ph10 111 that is needed.
859 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
860     as "const" (a) because they are and (b) because it helps the PHP
861     maintainers who have recently made a script to detect big data structures
862 ph10 111 in the php code that should be moved to the .rodata section. I remembered
863     to update Builducptable as well, so it won't revert if ucptable.h is ever
864 ph10 105 re-created.
865 ph10 111
866     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
867 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
868 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
869     support is not required. This saves 1.5-2K of code, which is important in
870 ph10 107 some applications.
871 ph10 111
872 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
873 ph10 111 so as not to refer to the tables, even though these functions will never be
874     called when UTF-8 support is disabled. Otherwise there are problems with a
875     shared library.
877 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
879     (a) It was defining its arguments as char * instead of void *.
881 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
882     a long time ago when I wrote it, but is no longer the case.
884 ph10 118 The emulated memove() is provided for those environments that have neither
885 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
886 ph10 118 is clearly not the case, as these two bugs were recently reported.
887 ph10 123
888 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
889 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
890     pages, and it removes trailing spaces from listed files. It also creates
891     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
892     case, it wraps all the #defines with #ifndefs. This script should be run
893 ph10 111 before "make dist".
894 ph10 123
895 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
896     with Unicode property support.
897 ph10 123
898     (a) For a maximizing quantifier, if the two different cases of the
899     character were of different lengths in their UTF-8 codings (there are
900     some cases like this - I found 11), and the matching function had to
901 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
902     were both the same length.
903 ph10 123
904     (b) When PCRE was configured to use the heap rather than the stack for
905     recursion during matching, it was not correctly preserving the data for
906     the other case of a UTF-8 character when checking ahead for a match
907     while processing a minimizing repeat. If the check also involved
908 ph10 115 matching a wide character, but failed, corruption could cause an
909     erroneous result when trying to check for a repeat of the original
910     character.
911 ph10 123
912 ph10 116 13. Some tidying changes to the testing mechanism:
913 ph10 98
914 ph10 116 (a) The RunTest script now detects the internal link size and whether there
915     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
916 ph10 123 values substituted by "configure". (The RunGrepTest script already did
917     this for UTF-8.) The configure.ac script no longer substitutes the
918     relevant variables.
920 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
921     with length and offset values. This means that the output is different
922     for different internal link sizes. Test 2 is skipped for link sizes
923     other than 2 because of this, bypassing the problem. Unfortunately,
924     there was also a test in test 3 (the locale tests) that used /B and
925 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
926     I have added a new /Z option to pcretest that replaces the length and
927     offset values with spaces. This is now used to make test 3 independent
928 ph10 122 of link size. (Test 2 will be tidied up later.)
929 ph10 123
930     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
931 ph10 122 segmentation fault instead of returning the appropriate error message.
932 ph10 134
933 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
934 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
935     This doesn't seem right; it now treats the CRLF combination as the line
936     ending, and so does not match in that case. It's only a pattern such as ^$
937     that would hit this one: something like ^ABC$ would have failed after \r
938     and then tried again after \r\n.
940 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
941 ph10 134 in an attempt to make files that differ only in their line terminators
942     compare equal. This works on Linux.
943 ph10 142
944 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
945     as it exited. This is now fixed, thanks to valgrind.
946 ph10 142
947 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
948 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
949     was because its rules for how to advance for /g after matching an empty
950 ph10 143 string at the end of a line did not allow for this case. They now check for
951     it specially.
952 ph10 150
953     20. pcretest is supposed to handle patterns and data of any length, by
954     extending its buffers when necessary. It was getting this wrong when the
955 ph10 147 buffer for a data line had to be extended.
956 ph10 150
957 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
958 ph10 150 CRLF as a newline sequence.
959 ph10 152
960 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
961 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
962     I have nevertheless tidied it up.
963 ph10 111
964 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
965 ph10 123
966 ph10 153 24. Added a man page for pcre-config.
967 ph10 152
968 ph10 153
969 nigel 93 Version 7.0 19-Dec-06
970     ---------------------
972     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
973     moving to gcc 4.1.1.
975     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
976     sys/time.h, which is documented as needed for this function. It doesn't
977     seem to matter on Linux, but it showed up on some releases of OS X.
979     3. It seems that there are systems where bytes whose values are greater than
980     127 match isprint() in the "C" locale. The "C" locale should be the
981     default when a C program starts up. In most systems, only ASCII printing
982     characters match isprint(). This difference caused the output from pcretest
983     to vary, making some of the tests fail. I have changed pcretest so that:
985     (a) When it is outputting text in the compiled version of a pattern, bytes
986     other than 32-126 are always shown as hex escapes.
988     (b) When it is outputting text that is a matched part of a subject string,
989     it does the same, unless a different locale has been set for the match
990     (using the /L modifier). In this case, it uses isprint() to decide.
992     4. Fixed a major bug that caused incorrect computation of the amount of memory
993     required for a compiled pattern when options that changed within the
994     pattern affected the logic of the preliminary scan that determines the
995     length. The relevant options are -x, and -i in UTF-8 mode. The result was
996     that the computed length was too small. The symptoms of this bug were
997     either the PCRE error "internal error: code overflow" from pcre_compile(),
998     or a glibc crash with a message such as "pcretest: free(): invalid next
999     size (fast)". Examples of patterns that provoked this bug (shown in
1000     pcretest format) are:
1002     /(?-x: )/x
1003     /(?x)(?-x: \s*#\s*)/
1004     /((?i)[\x{c0}])/8
1005     /(?i:[\x{c0}])/8
1007     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1008     is now done differently.
1010     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1011     wrapper classes; (b) implement a new function in the C++ scanner that is
1012     more efficient than the old way of doing things because it avoids levels of
1013     recursion in the regex matching; (c) add a paragraph to the documentation
1014     for the FullMatch() function.
1016     6. The escape sequence \n was being treated as whatever was defined as
1017     "newline". Not only was this contrary to the documentation, which states
1018     that \n is character 10 (hex 0A), but it also went horribly wrong when
1019     "newline" was defined as CRLF. This has been fixed.
1021     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1022     was being set to -1 for the "end of line" case (supposedly a value that no
1023     character can have). Though this value is never used (the check for end of
1024     line is "zero bytes in current character"), it caused compiler complaints.
1025     I've changed it to 0xffffffff.
1027     8. In pcre_version.c, the version string was being built by a sequence of
1028     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1029     string (as it is for production releases) called a macro with an empty
1030     argument. The C standard says the result of this is undefined. The gcc
1031     compiler treats it as an empty string (which was what was wanted) but it is
1032     reported that Visual C gives an error. The source has been hacked around to
1033     avoid this problem.
1035     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1036     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1037     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1038     of them did).
1040     10. Originally, pcretest opened its input and output without "b"; then I was
1041     told that "b" was needed in some environments, so it was added for release
1042     5.0 to both the input and output. (It makes no difference on Unix-like
1043     systems.) Later I was told that it is wrong for the input on Windows. I've
1044     now abstracted the modes into two macros, to make it easier to fiddle with
1045     them, and removed "b" from the input mode under Windows.
1047     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1049     12. Added -help and --help to pcretest as an official way of being reminded
1050     of the options.
1052     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1053     and pcrecpp.cc because they annoy compilers at high warning levels.
1055     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1057     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1058     scripts are not C programs :-) and which was not noticed because it works
1059     on Linux.
1061     16. pcretest is supposed to handle any length of pattern and data line (as one
1062     line or as a continued sequence of lines) by extending its input buffer if
1063     necessary. This feature was broken for very long pattern lines, leading to
1064     a string of junk being passed to pcre_compile() if the pattern was longer
1065     than about 50K.
1067     17. I have done a major re-factoring of the way pcre_compile() computes the
1068     amount of memory needed for a compiled pattern. Previously, there was code
1069     that made a preliminary scan of the pattern in order to do this. That was
1070     OK when PCRE was new, but as the facilities have expanded, it has become
1071     harder and harder to keep it in step with the real compile phase, and there
1072     have been a number of bugs (see for example, 4 above). I have now found a
1073     cunning way of running the real compile function in a "fake" mode that
1074     enables it to compute how much memory it would need, while actually only
1075     ever using a few hundred bytes of working memory and without too many
1076     tests of the mode. This should make future maintenance and development
1077     easier. A side effect of this work is that the limit of 200 on the nesting
1078     depth of parentheses has been removed (though this was never a serious
1079     limitation, I suspect). However, there is a downside: pcre_compile() now
1080     runs more slowly than before (30% or more, depending on the pattern). I
1081     hope this isn't a big issue. There is no effect on runtime performance.
1083     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1084     newline (only possible for the last line of a file) and it was a
1085     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1087     19. Added additional timing features to pcretest. (1) The -tm option now times
1088     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1089     separate command line item, by a number that specifies the number of
1090     repeats to use when timing. The default is 50000; this gives better
1091     precision, but takes uncomfortably long for very large patterns.
1093     20. Extended pcre_study() to be more clever in cases where a branch of a
1094     subpattern has no definite first character. For example, (a*|b*)[cd] would
1095     previously give no result from pcre_study(). Now it recognizes that the
1096     first character must be a, b, c, or d.
1098     21. There was an incorrect error "recursive call could loop indefinitely" if
1099     a subpattern (or the entire pattern) that was being tested for matching an
1100     empty string contained only one non-empty item after a nested subpattern.
1101     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1102     incorrectly, because the \d was being skipped in the check.
1104     22. The pcretest program now has a new pattern option /B and a command line
1105     option -b, which is equivalent to adding /B to every pattern. This causes
1106     it to show the compiled bytecode, without the additional information that
1107     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1108     is the same as /B/I).
1110     23. A new optimization is now able automatically to treat some sequences such
1111     as a*b as a*+b. More specifically, if something simple (such as a character
1112     or a simple class like \d) has an unlimited quantifier, and is followed by
1113     something that cannot possibly match the quantified thing, the quantifier
1114     is automatically "possessified".
1116     24. A recursive reference to a subpattern whose number was greater than 39
1117     went wrong under certain circumstances in UTF-8 mode. This bug could also
1118     have affected the operation of pcre_study().
1120     25. Realized that a little bit of performance could be had by replacing
1121     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1123     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1125     27. Possessive quantifiers such as a++ were previously implemented by turning
1126     them into atomic groups such as ($>a+). Now they have their own opcodes,
1127     which improves performance. This includes the automatically created ones
1128     from 23 above.
1130     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1131     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1132     the first matched character to be a colon. This applied both to named and
1133     numbered groups.
1135     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1137     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1138     building PCRE on Windows easier, so I have included it in the distribution.
1140     31. There is now a check in pcretest against a ridiculously large number being
1141     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1142     loop, the loop is abandoned.
1144     32. Forward references to subpatterns in conditions such as (?(2)...) where
1145     subpattern 2 is defined later cause pcre_compile() to search forwards in
1146     the pattern for the relevant set of parentheses. This search went wrong
1147     when there were unescaped parentheses in a character class, parentheses
1148     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1150     33. "Subroutine" calls and backreferences were previously restricted to
1151     referencing subpatterns earlier in the regex. This restriction has now
1152     been removed.
1154     34. Added a number of extra features that are going to be in Perl 5.10. On the
1155     whole, these are just syntactic alternatives for features that PCRE had
1156     previously implemented using the Python syntax or my own invention. The
1157     other formats are all retained for compatibility.
1159     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1160     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1161     also .NET compatible.
1163     (b) A recursion or subroutine call to a named group can now be defined as
1164     (?&name) as well as (?P>name).
1166     (c) A backreference to a named group can now be defined as \k<name> or
1167     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1168     5.10, are also .NET compatible.
1170     (d) A conditional reference to a named group can now use the syntax
1171     (?(<name>) or (?('name') as well as (?(name).
1173     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1174     groups (named and numbered) that are never evaluated inline, but can be
1175     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1176     is always false. There may be only one alternative in such a group.
1178     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1179     as the simple (?(R). The condition is true only if the most recent
1180     recursion is that of the given number or name. It does not search out
1181     through the entire recursion stack.
1183     (g) The escape \gN or \g{N} has been added, where N is a positive or
1184     negative number, specifying an absolute or relative reference.
1186     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1187     some "unreachable code" warnings.
1189     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1190     things, this adds five new scripts.
1192     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1193     There were also incompatibilities regarding the handling of \Q..\E inside
1194     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1195     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1197     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1198     matches an empty string, and forcibly breaks the loop. There were bugs in
1199     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1200     against aaaa the result was just "a" rather than "aaaa", for example. Two
1201     separate and independent bugs (that affected different cases) have been
1202     fixed.
1204     39. Refactored the code to abolish the use of different opcodes for small
1205     capturing bracket numbers. This is a tidy that I avoided doing when I
1206     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1207     The new approach is not only tidier, it makes it possible to reduce the
1208     memory needed to fix the previous bug (38).
1210     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1211     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1212     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1213     mode.
1215     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1216     report.
1218     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1219     copy construction and assignment in the C++ wrapper.
1221     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1222     couple of bugs that could have given wrong results in the "--newline=crlf"
1223     case.
1225     44. Added a number of casts and did some reorganization of signed/unsigned int
1226     variables following suggestions from Dair Grant. Also renamed the variable
1227     "this" as "item" because it is a C++ keyword.
1229     45. Arranged for dftables to add
1231     #include "pcre_internal.h"
1233     to pcre_chartables.c because without it, gcc 4.x may remove the array
1234     definition from the final binary if PCRE is built into a static library and
1235     dead code stripping is activated.
1237     46. For an unanchored pattern, if a match attempt fails at the start of a
1238     newline sequence, and the newline setting is CRLF or ANY, and the next two
1239     characters are CRLF, advance by two characters instead of one.
1242 nigel 91 Version 6.7 04-Jul-06
1243     ---------------------
1245     1. In order to handle tests when input lines are enormously long, pcretest has
1246     been re-factored so that it automatically extends its buffers when
1247     necessary. The code is crude, but this _is_ just a test program. The
1248     default size has been increased from 32K to 50K.
1250     2. The code in pcre_study() was using the value of the re argument before
1251     testing it for NULL. (Of course, in any sensible call of the function, it
1252     won't be NULL.)
1254     3. The memmove() emulation function in pcre_internal.h, which is used on
1255     systems that lack both memmove() and bcopy() - that is, hardly ever -
1256     was missing a "static" storage class specifier.
1258     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1259     containing an extended class (one that cannot be represented by a bitmap
1260     because it contains high-valued characters or Unicode property items, e.g.
1261     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1262     pattern, but PCRE should not loop if you do not (it no longer does).
1263     [Detail: two cases were found: (a) a repeated subpattern containing an
1264     extended class; (b) a recursive reference to a subpattern that followed a
1265     previous extended class. It wasn't skipping over the extended class
1266     correctly when UTF-8 mode was not set.]
1268     5. A negated single-character class was not being recognized as fixed-length
1269     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1270     compile error "lookbehind assertion is not fixed length".
1272     6. The RunPerlTest auxiliary script was showing an unexpected difference
1273     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1274     write a Perl script that can interpret lines of an input file either as
1275     byte characters or as UTF-8, which is what "perltest" was being required to
1276     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1277     can't do is switch easily at run time between having the "use utf8;" pragma
1278     or not. In the end, I fudged it by using the RunPerlTest script to insert
1279     "use utf8;" explicitly for the UTF-8 tests.
1281     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1282     the end of the subject string, contrary to the documentation and to what
1283     Perl does. This was true of both matching functions. Now it matches only at
1284     the start of the subject and immediately after *internal* newlines.
1286     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1287     a pointer to an int instead of a pointer to an unsigned long int. This
1288     caused problems on 64-bit systems.
1290     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1291     instance of the 'standard' template library not being so standard".
1293     10. There was no check on the number of named subpatterns nor the maximum
1294     length of a subpattern name. The product of these values is used to compute
1295     the size of the memory block for a compiled pattern. By supplying a very
1296     long subpattern name and a large number of named subpatterns, the size
1297     computation could be caused to overflow. This is now prevented by limiting
1298     the length of names to 32 characters, and the number of named subpatterns
1299     to 10,000.
1301     11. Subpatterns that are repeated with specific counts have to be replicated in
1302     the compiled pattern. The size of memory for this was computed from the
1303     length of the subpattern and the repeat count. The latter is limited to
1304     65535, but there was no limit on the former, meaning that integer overflow
1305     could in principle occur. The compiled length of a repeated subpattern is
1306     now limited to 30,000 bytes in order to prevent this.
1308     12. Added the optional facility to have named substrings with the same name.
1310     13. Added the ability to use a named substring as a condition, using the
1311     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1312     are numbers (not recommended). Forward references are permitted.
1314     14. Added forward references in named backreferences (if you see what I mean).
1316     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1317     pattern could run off the end of the subject. For example, the pattern
1318     "(?s)(.{1,5})"8 did this with the subject "ab".
1320     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1321     PCRE_CASELESS was set when matching characters that were quantified with ?
1322     or *.
1324     17. A character class other than a single negated character that had a minimum
1325     but no maximum quantifier - for example [ab]{6,} - was not handled
1326     correctly by pce_dfa_exec(). It would match only one character.
1328     18. A valid (though odd) pattern that looked like a POSIX character
1329     class but used an invalid character after [ (for example [[,abc,]]) caused
1330     pcre_compile() to give the error "Failed: internal error: code overflow" or
1331     in some cases to crash with a glibc free() error. This could even happen if
1332     the pattern terminated after [[ but there just happened to be a sequence of
1333     letters, a binary zero, and a closing ] in the memory that followed.
1335     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1336     over the years. Originally (before any Unicode support), just the bottom 8
1337     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1338     output from "man perlunicode" includes this:
1340     The regular expression compiler produces polymorphic opcodes. That
1341     is, the pattern adapts to the data and automatically switches to
1342     the Unicode character scheme when presented with Unicode data--or
1343     instead uses a traditional byte scheme when presented with byte
1344     data.
1346     Sadly, a wide octal escape does not cause a switch, and in a string with
1347     no other multibyte characters, these octal escapes are treated as before.
1348     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1349     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1350     Unicode string.
1352     I have not perpetrated such confusion in PCRE. Up till now, it took just
1353     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1354     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1355     translate to the appropriate multibyte character.
1357     29. Applied some refactoring to reduce the number of warnings from Microsoft
1358     and Borland compilers. This has included removing the fudge introduced
1359     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1360     a warning about an unused variable.
1362     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1363     characters since release 4.0, because Perl (from release 5.004) does not.
1364     [Or at least, is documented not to: some releases seem to be in conflict
1365     with the documentation.] However, when a pattern was studied with
1366     pcre_study() and all its branches started with \s, PCRE still included VT
1367     as a possible starting character. Of course, this did no harm; it just
1368     caused an unnecessary match attempt.
1370     22. Removed a now-redundant internal flag bit that recorded the fact that case
1371     dependency changed within the pattern. This was once needed for "required
1372     byte" processing, but is no longer used. This recovers a now-scarce options
1373     bit. Also moved the least significant internal flag bit to the most-
1374     significant bit of the word, which was not previously used (hangover from
1375     the days when it was an int rather than a uint) to free up another bit for
1376     the future.
1378     23. Added support for CRLF line endings as well as CR and LF. As well as the
1379     default being selectable at build time, it can now be changed at runtime
1380     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1381     specify that it is scanning data with non-default line endings.
1383     24. Changed the definition of CXXLINK to make it agree with the definition of
1384     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1386     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1387     recursions. This makes a big different to stack usage for some patterns.
1389     26. If a subpattern containing a named recursion or subroutine reference such
1390     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1391     the space required for the compiled pattern went wrong and gave too small a
1392     value. Depending on the environment, this could lead to "Failed: internal
1393     error: code overflow at offset 49" or "glibc detected double free or
1394     corruption" errors.
1396     27. Applied patches from Google (a) to support the new newline modes and (b) to
1397     advance over multibyte UTF-8 characters in GlobalReplace.
1399     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1400     difference for some implementation of PCRE in some Windows version.
1402     29. Added some extra testing facilities to pcretest:
1404     \q<number> in a data line sets the "match limit" value
1405     \Q<number> in a data line sets the "match recursion limt" value
1406     -S <number> sets the stack size, where <number> is in megabytes
1408     The -S option isn't available for Windows.
1411 nigel 89 Version 6.6 06-Feb-06
1412     ---------------------
1414     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1415     in pcreposix.h. I have copied the definition from pcre.h.
1417     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1418     because pcre.h is no longer a built file.
1420     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1421     not normally included in the compiled code.
1424 nigel 87 Version 6.5 01-Feb-06
1425     ---------------------
1427     1. When using the partial match feature with pcre_dfa_exec(), it was not
1428     anchoring the second and subsequent partial matches at the new starting
1429     point. This could lead to incorrect results. For example, with the pattern
1430     /1234/, partially matching against "123" and then "a4" gave a match.
1432     2. Changes to pcregrep:
1434     (a) All non-match returns from pcre_exec() were being treated as failures
1435     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1436     error message is output. Some extra information is given for the
1438     probably the only errors that are likely to be caused by users (by
1439     specifying a regex that has nested indefinite repeats, for instance).
1440     If there are more than 20 of these errors, pcregrep is abandoned.
1442     (b) A binary zero was treated as data while matching, but terminated the
1443     output line if it was written out. This has been fixed: binary zeroes
1444     are now no different to any other data bytes.
1446     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1447     used to set a locale for matching. The --locale=xxxx long option has
1448     been added (no short equivalent) to specify a locale explicitly on the
1449     pcregrep command, overriding the environment variables.
1451     (d) When -B was used with -n, some line numbers in the output were one less
1452     than they should have been.
1454     (e) Added the -o (--only-matching) option.
1456     (f) If -A or -C was used with -c (count only), some lines of context were
1457     accidentally printed for the final match.
1459     (g) Added the -H (--with-filename) option.
1461     (h) The combination of options -rh failed to suppress file names for files
1462     that were found from directory arguments.
1464     (i) Added the -D (--devices) and -d (--directories) options.
1466     (j) Added the -F (--fixed-strings) option.
1468     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1470     (l) Added the --colo(u)r option.
1472     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1473     is not present by default.
1475     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1476     items such as (?R) or (?1), when the recursion could match a number of
1477     alternatives. If it matched one of the alternatives, but subsequently,
1478     outside the recursion, there was a failure, the code tried to back up into
1479     the recursion. However, because of the way PCRE is implemented, this is not
1480     possible, and the result was an incorrect result from the match.
1482     In order to prevent this happening, the specification of recursion has
1483     been changed so that all such subpatterns are automatically treated as
1484     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1486     4. I had overlooked the fact that, in some locales, there are characters for
1487     which isalpha() is true but neither isupper() nor islower() are true. In
1488     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1489     and ordfeminine) are like this. This affected the treatment of \w and \W
1490     when they appeared in character classes, but not when they appeared outside
1491     a character class. The bit map for "word" characters is now created
1492     separately from the results of isalnum() instead of just taking it from the
1493     upper, lower, and digit maps. (Plus the underscore character, of course.)
1495     5. The above bug also affected the handling of POSIX character classes such as
1496     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1497     permanent tables. Instead, the bit maps for such a class were previously
1498     created as the appropriate unions of the upper, lower, and digit bitmaps.
1499     Now they are created by subtraction from the [[:word:]] class, which has
1500     its own bitmap.
1502     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1503     It is created by subtracting the vertical space characters (\x09, \x0a,
1504     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1505     subtraction was done in the overall bitmap for a character class, meaning
1506     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1507     be recognized. This bug has been fixed.
1509     7. Patches from the folks at Google:
1511     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1512     real life, but is still worth protecting against".
1514     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1515     regular expressions".
1517     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1518     have it.
1520     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1521     "configure" and the latter not, in order to fix a problem somebody had
1522     with compiling the Arg class on HP-UX.
1524     (e) Improve the error-handling of the C++ wrapper a little bit.
1526     (f) New tests for checking recursion limiting.
1528     8. The pcre_memmove() function, which is used only if the environment does not
1529     have a standard memmove() function (and is therefore rarely compiled),
1530     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1531     returning a result (though PCRE never actually uses the result).
1533     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1534     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1535     returned instead of calling malloc() with an overflowing number that would
1536     most likely cause subsequent chaos.
1538     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1540     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1541     with this option is matched, the nmatch and pmatch options of regexec() are
1542     ignored.
1544     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1545     provided in case anyone wants to the the POSIX interface with UTF-8
1546     strings.
1548     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1549     C++ linking (needed for some HP-UX environments).
1551     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1552     (unused parameter) and in the pcre_printint() function (omitted "default"
1553     switch label when the default is to do nothing).
1555     15. Added some code to make it possible, when PCRE is compiled as a C++
1556     library, to replace subject pointers for pcre_exec() with a smart pointer
1557     class, thus making it possible to process discontinuous strings.
1559     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1560     much the same function. They were added by different people who were trying
1561     to make PCRE easy to compile on non-Unix systems. It has been suggested
1562     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1563     for compiling on Windows systems. I have therefore replaced it with
1564     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1565     defaults to "extern" for C or "extern C" for C++, which works fine on
1566     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1567     SCOPE with something explicit in config.h. In addition:
1569     (a) pcreposix.h still had just "extern" instead of either of these macros;
1570     I have replaced it with PCRE_DATA_SCOPE.
1572     (b) Functions such as _pcre_xclass(), which are internal to the library,
1573     but external in the C sense, all had PCRE_EXPORT in their definitions.
1574     This is apparently wrong for the Windows case, so I have removed it.
1575     (It makes no difference on Unix-like systems.)
1577     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1578     of recursive calls to match(). This is different to MATCH_LIMIT because
1579     that limits the total number of calls to match(), not all of which increase
1580     the depth of recursion. Limiting the recursion depth limits the amount of
1581     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1582     when PCRE is compiled, and changed at run time. A patch from Google adds
1583     this functionality to the C++ interface.
1585     18. Changes to the handling of Unicode character properties:
1587     (a) Updated the table to Unicode 4.1.0.
1589     (b) Recognize characters that are not in the table as "Cn" (undefined).
1591     (c) I revised the way the table is implemented to a much improved format
1592     which includes recognition of ranges. It now supports the ranges that
1593     are defined in UnicodeData.txt, and it also amalgamates other
1594     characters into ranges. This has reduced the number of entries in the
1595     table from around 16,000 to around 3,000, thus reducing its size
1596     considerably. I realized I did not need to use a tree structure after
1597     all - a binary chop search is just as efficient. Having reduced the
1598     number of entries, I extended their size from 6 bytes to 8 bytes to
1599     allow for more data.
1601     (d) Added support for Unicode script names via properties such as \p{Han}.
1603     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1604     matching that character.
1606     20. When matching a repeated Unicode property with a minimum greater than zero,
1607     (for example \pL{2,}), PCRE could look past the end of the subject if it
1608     reached it while seeking the minimum number of characters. This could
1609     happen only if some of the characters were more than one byte long, because
1610     there is a check for at least the minimum number of bytes.
1612     21. Refactored the implementation of \p and \P so as to be more general, to
1613     allow for more different types of property in future. This has changed the
1614     compiled form incompatibly. Anybody with saved compiled patterns that use
1615     \p or \P will have to recompile them.
1617     22. Added "Any" and "L&" to the supported property types.
1619     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1620     but give a compile time error if the value is greater than 0xff.
1622     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1623     accidentally not being installed or uninstalled.
1625     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1626     made were to insert the current release number. This seemed silly, because
1627     it made things harder for people building PCRE on systems that don't run
1628     "configure". I have turned pcre.h into a distributed file, no longer built
1629     by "configure", with the version identification directly included. There is
1630     no longer a pcre.h.in file.
1632     However, this change necessitated a change to the pcre-config script as
1633     well. It is built from pcre-config.in, and one of the substitutions was the
1634     release number. I have updated configure.ac so that ./configure now finds
1635     the release number by grepping pcre.h.
1637     26. Added the ability to run the tests under valgrind.
1640 nigel 85 Version 6.4 05-Sep-05
1641     ---------------------
1643     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1644     "--" to be printed when multiple files were scanned, even when none of the
1645     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1646     consider it to be a bug, and have restored the previous behaviour.
1648     2. A couple of code tidies to get rid of compiler warnings.
1650     3. The pcretest program used to cheat by referring to symbols in the library
1651     whose names begin with _pcre_. These are internal symbols that are not
1652     really supposed to be visible externally, and in some environments it is
1653     possible to suppress them. The cheating is now confined to including
1654     certain files from the library's source, which is a bit cleaner.
1656     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1657     file's purpose clearer.
1659     5. Reorganized pcre_ucp_findchar().
1662 nigel 83 Version 6.3 15-Aug-05
1663     ---------------------
1665     1. The file libpcre.pc.in did not have general read permission in the tarball.
1667     2. There were some problems when building without C++ support:
1669     (a) If C++ support was not built, "make install" and "make test" still
1670     tried to test it.
1672     (b) There were problems when the value of CXX was explicitly set. Some
1673     changes have been made to try to fix these, and ...
1675     (c) --disable-cpp can now be used to explicitly disable C++ support.
1677     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1678     backslash in a target when C++ was disabled. This confuses some
1679     versions of "make", apparently. Using an intermediate variable solves
1680     this. (Same for CPP_LOBJ.)
1682     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1683     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1684     necessary on certain architectures.
1686     4. Added a setting of -export-symbols-regex to the link command to remove
1687     those symbols that are exported in the C sense, but actually are local
1688     within the library, and not documented. Their names all begin with
1689     "_pcre_". This is not a perfect job, because (a) we have to except some
1690     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1691     available (and never for static libraries). I have made a note to try to
1692     find a way round (a) in the future.
1695 nigel 81 Version 6.2 01-Aug-05
1696     ---------------------
1698     1. There was no test for integer overflow of quantifier values. A construction
1699     such as {1111111111111111} would give undefined results. What is worse, if
1700     a minimum quantifier for a parenthesized subpattern overflowed and became
1701     negative, the calculation of the memory size went wrong. This could have
1702     led to memory overwriting.
1704     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1706     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1707     operating environments where this matters.
1709     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1710     PCRE options from within the C++ wrapper.
1712     5. Named capturing subpatterns were not being correctly counted when a pattern
1713     was compiled. This caused two problems: (a) If there were more than 100
1714     such subpatterns, the calculation of the memory needed for the whole
1715     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1716     back references of the form \12, where the number was greater than 9, were
1717     not recognized as back references, even though there were sufficient
1718     previous subpatterns.
1720     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1721     versions of gcc, e.g. 2.95.4.
1724 nigel 79 Version 6.1 21-Jun-05
1725     ---------------------
1727     1. There was one reference to the variable "posix" in pcretest.c that was not
1728     surrounded by "#if !defined NOPOSIX".
1730     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1731     the cross-check on the old pcre_info() function, for the benefit of the
1732     cut-down version of PCRE that is currently imported into Exim.
1734     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1735     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1736     patterns that start (?i) but I don't think that matters. The use of (?i) is
1737     just an example; this all applies to the other options as well.
1739     4. Since libtool seems to echo the compile commands it is issuing, the output
1740     from "make" can be reduced a bit by putting "@" in front of each libtool
1741     compile command.
1743     5. Patch from the folks at Google for configure.in to be a bit more thorough
1744     in checking for a suitable C++ installation before trying to compile the
1745     C++ stuff. This should fix a reported problem when a compiler was present,
1746     but no suitable headers.
1748     6. The man pages all had just "PCRE" as their title. I have changed them to
1749     be the relevant file name. I have also arranged that these names are
1750     retained in the file doc/pcre.txt, which is a concatenation in text format
1751     of all the man pages except the little individual ones for each function.
1753     7. The NON-UNIX-USE file had not been updated for the different set of source
1754     files that come with release 6. I also added a few comments about the C++
1755     wrapper.
1758 nigel 77 Version 6.0 07-Jun-05
1759     ---------------------
1761     1. Some minor internal re-organization to help with my DFA experiments.
1763     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1764     didn't matter for the library itself when fully configured, but did matter
1765     when compiling without UCP support, or within Exim, where the ucp files are
1766     not imported.
1768     3. Refactoring of the library code to split up the various functions into
1769     different source modules. The addition of the new DFA matching code (see
1770     below) to a single monolithic source would have made it really too
1771     unwieldy, quite apart from causing all the code to be include in a
1772     statically linked application, when only some functions are used. This is
1773     relevant even without the DFA addition now that patterns can be compiled in
1774     one application and matched in another.
1776     The downside of splitting up is that there have to be some external
1777     functions and data tables that are used internally in different modules of
1778     the library but which are not part of the API. These have all had their
1779     names changed to start with "_pcre_" so that they are unlikely to clash
1780     with other external names.
1782     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1783     a different (DFA) algorithm. Although it is slower than the original
1784     function, it does have some advantages for certain types of matching
1785     problem.
1787     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1788     including restarting after a partial match.
1790     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1791     defined when compiling for Windows was sent to me. I have put it into the
1792     code, though I have no means of testing or verifying it.
1794     7. Added the pcre_refcount() auxiliary function.
1796     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1797     match before or at the first newline in the subject string. In pcretest,
1798     the /f option on a pattern can be used to set this.
1800     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1801     would behave wrongly. This has been present in PCRE since release 4.0.
1803     10. A number of changes to the pcregrep command:
1805     (a) Refactored how -x works; insert ^(...)$ instead of setting
1806     PCRE_ANCHORED and checking the length, in preparation for adding
1807     something similar for -w.
1809     (b) Added the -w (match as a word) option.
1811     (c) Refactored the way lines are read and buffered so as to have more
1812     than one at a time available.
1814     (d) Implemented a pcregrep test script.
1816     (e) Added the -M (multiline match) option. This allows patterns to match
1817     over several lines of the subject. The buffering ensures that at least
1818     8K, or the rest of the document (whichever is the shorter) is available
1819     for matching (and similarly the previous 8K for lookbehind assertions).
1821     (f) Changed the --help output so that it now says
1823     -w, --word-regex(p)
1825     instead of two lines, one with "regex" and the other with "regexp"
1826     because that confused at least one person since the short forms are the
1827     same. (This required a bit of code, as the output is generated
1828     automatically from a table. It wasn't just a text change.)
1830     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1831     option but starts with a hyphen. Could be a pattern or a path name
1832     starting with a hyphen, for instance.
1834     (h) "-" can be given as a file name to represent stdin.
1836     (i) When file names are being printed, "(standard input)" is used for
1837     the standard input, for compatibility with GNU grep. Previously
1838     "<stdin>" was used.
1840     (j) The option --label=xxx can be used to supply a name to be used for
1841     stdin when file names are being printed. There is no short form.
1843     (k) Re-factored the options decoding logic because we are going to add
1844     two more options that take data. Such options can now be given in four
1845     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1847     (l) Added the -A, -B, and -C options for requesting that lines of context
1848     around matches be printed.
1850     (m) Added the -L option to print the names of files that do not contain
1851     any matching lines, that is, the complement of -l.
1853     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1854     continue to scan other files.
1856     (o) The -s option was incorrectly implemented. For compatibility with other
1857     greps, it now suppresses the error message for a non-existent or non-
1858     accessible file (but not the return code). There is a new option called
1859     -q that suppresses the output of matching lines, which was what -s was
1860     previously doing.
1862     (p) Added --include and --exclude options to specify files for inclusion
1863     and exclusion when recursing.
1865     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1866     Hopefully, it now does.
1868     12. Missing cast in pcre_study().
1870     13. Added an "uninstall" target to the makefile.
1872     14. Replaced "extern" in the function prototypes in Makefile.in with
1873     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1874     world, but is set differently for Windows.
1876     15. Added a second compiling function called pcre_compile2(). The only
1877     difference is that it has an extra argument, which is a pointer to an
1878     integer error code. When there is a compile-time failure, this is set
1879     non-zero, in addition to the error test pointer being set to point to an
1880     error message. The new argument may be NULL if no error number is required
1881     (but then you may as well call pcre_compile(), which is now just a
1882     wrapper). This facility is provided because some applications need a
1883     numeric error indication, but it has also enabled me to tidy up the way
1884     compile-time errors are handled in the POSIX wrapper.
1886     16. Added VPATH=.libs to the makefile; this should help when building with one
1887     prefix path and installing with another. (Or so I'm told by someone who
1888     knows more about this stuff than I do.)
1890     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1891     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1892     match everything, including newlines. This is not POSIX-compatible, but
1893     somebody wanted the feature. From pcretest it can be activated by using
1894     both the P and the s flags.
1896     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1898     19. libpcre.pc was being incorrectly installed as executable.
1900     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1901     it now also looks for '\r' so that it will work unmodified on Windows.
1903     21. Added Google's contributed C++ wrapper to the distribution.
1905     22. Added some untidy missing memory free() calls in pcretest, to keep
1906     Electric Fence happy when testing.
1910 nigel 75 Version 5.0 13-Sep-04
1911     ---------------------
1913     1. Internal change: literal characters are no longer packed up into items
1914     containing multiple characters in a single byte-string. Each character
1915     is now matched using a separate opcode. However, there may be more than one
1916     byte in the character in UTF-8 mode.
1918     2. The pcre_callout_block structure has two new fields: pattern_position and
1919     next_item_length. These contain the offset in the pattern to the next match
1920     item, and its length, respectively.
1922     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1923     insertion of callouts before each pattern item. Added the /C option to
1924     pcretest to make use of this.
1926     4. On the advice of a Windows user, the lines
1928     #if defined(_WIN32) || defined(WIN32)
1929     _setmode( _fileno( stdout ), 0x8000 );
1930     #endif /* defined(_WIN32) || defined(WIN32) */
1932     have been added to the source of pcretest. This apparently does useful
1933     magic in relation to line terminators.
1935     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1936     for the benefit of those environments where the "b" makes a difference.
1938     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1939     to know about it. I have put a hack into configure.in that adds in code
1940     to set GCC=yes if CC=icc. This seems to end up at a point in the
1941     generated configure script that is early enough to affect the setting of
1942     compiler options, which is what is needed, but I have no means of testing
1943     whether it really works. (The user who reported this had patched the
1944     generated configure script, which of course I cannot do.)
1946     LATER: After change 22 below (new libtool files), the configure script
1947     seems to know about icc (and also ecc). Therefore, I have commented out
1948     this hack in configure.in.
1950     7. Added support for pkg-config (2 patches were sent in).
1952     8. Negated POSIX character classes that used a combination of internal tables
1953     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1954     [[:^ascii]]. Typically, they would match almost any characters. The other
1955     POSIX classes were not broken in this way.
1957     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1958     to find the match, as PCRE was deluded into thinking that the match had to
1959     start at the start point or following a newline. The same bug applied to
1960     patterns with negative forward assertions or any backward assertions
1961     preceding ".*" at the start, unless the pattern required a fixed first
1962     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1964     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1965     starting at the last subject character, bytes beyond the end of the subject
1966     string were read.
1968     11. Renamed the variable "class" as "classbits" to make life easier for C++
1969     users. (Previously there was a macro definition, but it apparently wasn't
1970     enough.)
1972     12. Added the new field "tables" to the extra data so that tables can be passed
1973     in at exec time, or the internal tables can be re-selected. This allows
1974     a compiled regex to be saved and re-used at a later time by a different
1975     program that might have everything at different addresses.
1977     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1978     -R library as well as a -L library.
1980     14. The debugging options of pcretest (-d on the command line or D on a
1981     pattern) showed incorrect output for anything following an extended class
1982     that contained multibyte characters and which was followed by a quantifier.
1984     15. Added optional support for general category Unicode character properties
1985     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1986     support. It adds about 90K to the size of the library. The meanings of the
1987     inbuilt class escapes such as \d and \s have NOT been changed.
1989     16. Updated pcredemo.c to include calls to free() to release the memory for the
1990     compiled pattern.
1992     17. The generated file chartables.c was being created in the source directory
1993     instead of in the building directory. This caused the build to fail if the
1994     source directory was different from the building directory, and was
1995     read-only.
1997     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1998     file. No doubt somebody will tell me if they don't make sense... Also added
1999     Dan Mooney's comments about building on OpenVMS.
2001     19. Added support for partial matching via the PCRE_PARTIAL option for
2002     pcre_exec() and the \P data escape in pcretest.
2004     20. Extended pcretest with 3 new pattern features:
2006     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2007     write the compiled pattern to the file whose name is "rest-of-line".
2008     This is a straight binary dump of the data, with the saved pointer to
2009     the character tables forced to be NULL. The study data, if any, is
2010     written too. After writing, pcretest reads a new pattern.
2012     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2013     compiled pattern from the given file. There must not be any
2014     occurrences of "<" in the file name (pretty unlikely); if there are,
2015     pcretest will instead treat the initial "<" as a pattern delimiter.
2016     After reading in the pattern, pcretest goes on to read data lines as
2017     usual.
2019     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2020     and 16-bit fields in a compiled pattern, to simulate a pattern that
2021     was compiled on a host of opposite endianness.
2023     21. The pcre-exec() function can now cope with patterns that were compiled on
2024     hosts of opposite endianness, with this restriction:
2026     As for any compiled expression that is saved and used later, the tables
2027     pointer field cannot be preserved; the extra_data field in the arguments
2028     to pcre_exec() should be used to pass in a tables address if a value
2029     other than the default internal tables were used at compile time.
2031     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2032     now diagnosed as an error. Previously, most of the time, a negative number
2033     would have been treated as zero, but if in addition "ovector" was passed as
2034     NULL, a crash could occur.
2036     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2037     new versions from the libtool 1.5 distribution (the last one is a copy of
2038     a file called libtool.m4). This seems to have fixed the need to patch
2039     "configure" to support Darwin 1.3 (which I used to do). However, I still
2040     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2041     workstation).
2043     24. Changed the PCRE licence to be the more standard "BSD" licence.
2046 nigel 73 Version 4.5 01-Dec-03
2047     ---------------------
2049     1. There has been some re-arrangement of the code for the match() function so
2050     that it can be compiled in a version that does not call itself recursively.
2051     Instead, it keeps those local variables that need separate instances for
2052     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2053     needs to "recurse". Keeping track of where control must go is done by means
2054     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2055     hide most of the details from the main code, and operates only if
2056     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2057     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2058     operating.
2060     To make it easier for callers to provide specially tailored get/free
2061     functions for this usage, two new functions, pcre_stack_malloc, and
2062     pcre_stack_free, are used. They are always called in strict stacking order,
2063     and the size of block requested is always the same.
2065     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2066     PCRE has been compiled to use the stack or the heap for recursion. The
2067     -C option of pcretest uses this to show which version is compiled.
2069     A new data escape \S, is added to pcretest; it causes the amounts of store
2070     obtained and freed by both kinds of malloc/free at match time to be added
2071     to the output.
2073     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2074     what's available on my current Linux desktop machine.
2076     3. When matching a UTF-8 string, the test for a valid string at the start has
2077     been extended. If start_offset is not zero, PCRE now checks that it points
2078     to a byte that is the start of a UTF-8 character. If not, it returns
2079     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2080     this is necessary because there may be backward assertions in the pattern.
2081     When matching the same subject several times, it may save resources to use
2082     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2084     4. The code for checking the validity of UTF-8 strings has been tightened so
2085     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2086     containing "overlong sequences".
2088     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2089     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2090     should have been "&", but it just so happened that all the cases this let
2091     through by mistake were picked up later in the function.
2093     6. I had used a variable called "isblank" - this is a C99 function, causing
2094     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2096     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2097     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2098     so the version is shown; (c) stop "make test" echoing "./RunTest".
2100     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2102     9. The prototype for memmove() for systems that don't have it was using
2103     size_t, but the inclusion of the header that defines size_t was later. I've
2104     moved the #includes for the C headers earlier to avoid this.
2106     10. Added some adjustments to the code to make it easier to compiler on certain
2107     special systems:
2109     (a) Some "const" qualifiers were missing.
2110     (b) Added the macro EXPORT before all exported functions; by default this
2111     is defined to be empty.
2112     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2113     that it reads its output file name as an argument instead of writing
2114     to the standard output and assuming this can be redirected.
2116     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2117     class containing characters with values greater than 255, PCRE compilation
2118     went into a loop.
2120     12. A recursive reference to a subpattern that was within another subpattern
2121     that had a minimum quantifier of zero caused PCRE to crash. For example,
2122     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2123     recursion. If the recursively-called subpattern itself had a zero repeat,
2124     that was OK.
2126     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2127     buffer into which it was copied (for escape processing) was still set at
2128     1024, so long lines caused crashes.
2130     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2131     "internal error: code overflow...". This applied to any character class
2132     that was followed by a possessive quantifier.
2134     15. Modified the Makefile to add libpcre.la as a prerequisite for
2135     libpcreposix.la because I was told this is needed for a parallel build to
2136     work.
2138     16. If a pattern that contained .* following optional items at the start was
2139     studied, the wrong optimizing data was generated, leading to matching
2140     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2141     matching string must start with a or b or c. The correct conclusion for
2142     this pattern is that a match can start with any character.
2145 nigel 71 Version 4.4 13-Aug-03
2146     ---------------------
2148     1. In UTF-8 mode, a character class containing characters with values between
2149     127 and 255 was not handled correctly if the compiled pattern was studied.
2150     In fixing this, I have also improved the studying algorithm for such
2151     classes (slightly).
2153     2. Three internal functions had redundant arguments passed to them. Removal
2154     might give a very teeny performance improvement.
2156     3. Documentation bug: the value of the capture_top field in a callout is *one
2157     more than* the number of the hightest numbered captured substring.
2159     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2160     in incorrectly linking with a previously installed version. They now link
2161     explicitly with libpcre.la.
2163     5. configure.in no longer needs to recognize Cygwin specially.
2165     6. A problem in pcre.in for Windows platforms is fixed.
2167     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2168     pcretest, it used to include the size of the study block as part of its
2169     output. Unfortunately, the structure contains a field that has a different
2170     size on different hardware architectures. This meant that the tests that
2171     showed this size failed. As the block is currently always of a fixed size,
2172     this information isn't actually particularly useful in pcretest output, so
2173     I have just removed it.
2175     8. Three pre-processor statements accidentally did not start in column 1.
2176     Sadly, there are *still* compilers around that complain, even though
2177     standard C has not required this for well over a decade. Sigh.
2179     9. In pcretest, the code for checking callouts passed small integers in the
2180     callout_data field, which is a void * field. However, some picky compilers
2181     complained about the casts involved for this on 64-bit systems. Now
2182     pcretest passes the address of the small integer instead, which should get
2183     rid of the warnings.
2185     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2186     both compile and run time, and gives an error if an invalid UTF-8 sequence
2187     is found. There is a option for disabling this check in cases where the
2188     string is known to be correct and/or the maximum performance is wanted.
2190     11. In response to a bug report, I changed one line in Makefile.in from
2192     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2193     to
2194     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2196     to look similar to other lines, but I have no way of telling whether this
2197     is the right thing to do, as I do not use Windows. No doubt I'll get told
2198     if it's wrong...
2201 nigel 69 Version 4.3 21-May-03
2202     ---------------------
2204     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2205     Makefile.
2207     2. Some refactoring to improve the quality of the code:
2209     (i) The utf8_table... variables are now declared "const".
2211     (ii) The code for \cx, which used the "case flipping" table to upper case
2212     lower case letters, now just substracts 32. This is ASCII-specific,
2213     but the whole concept of \cx is ASCII-specific, so it seems
2214     reasonable.
2216     (iii) PCRE was using its character types table to recognize decimal and
2217     hexadecimal digits in the pattern. This is silly, because it handles
2218     only 0-9, a-f, and A-F, but the character types table is locale-
2219     specific, which means strange things might happen. A private
2220     table is now used for this - though it costs 256 bytes, a table is
2221     much faster than multiple explicit tests. Of course, the standard
2222     character types table is still used for matching digits in subject
2223     strings against \d.
2225     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2226     ending in _t are). So I've renamed it as ESC_tee.
2228     3. The first argument for regexec() in the POSIX wrapper should have been
2229     defined as "const".
2231     4. Changed pcretest to use malloc() for its buffers so that they can be
2232     Electric Fenced for debugging.
2234     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2235     to read one or more bytes before the start of the subject string. Often this
2236     had no effect on PCRE's behaviour, but in some circumstances it could
2237     provoke a segmentation fault.
2239     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2240     to try to read one or more bytes before the start of the subject string.
2242     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2243     UTF-8 support could misbehave in various ways if the subject string
2244     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2245     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2246     back over UTF-8 characters.)
2249 nigel 67 Version 4.2 14-Apr-03
2250     ---------------------
2252     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2254     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2255     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2256     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2257     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2258     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2259     and BUILD_EXEEXT
2260     Note: automatic setting of the BUILD variables is not yet working
2261     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2262     compile-time but not at link-time
2263     [LINK]: use for linking executables only
2264     make different versions for Windows and non-Windows
2265     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2266     libraries
2267     [LINK_FOR_BUILD]: new variable
2268     [OBJEXT]: use throughout
2269     [EXEEXT]: use throughout
2270     <winshared>: new target
2271     <wininstall>: new target
2272     <dftables.o>: use native compiler
2273     <dftables>: use native linker
2274     <install>: handle Windows platform correctly
2275     <clean>: ditto
2276     <check>: ditto
2277     copy DLL to top builddir before testing
2279     As part of these changes, -no-undefined was removed again. This was reported
2280     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2281     in any case.
2283     3. Some tidies to get rid of compiler warnings:
2285     . In the match_data structure, match_limit was an unsigned long int, whereas
2286     match_call_count was an int. I've made them both unsigned long ints.
2288     . In pcretest the fact that a const uschar * doesn't automatically cast to
2289     a void * provoked a warning.
2291     . Turning on some more compiler warnings threw up some "shadow" variables
2292     and a few more missing casts.
2294     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2295     option, a class that contained a single character with a value between 128
2296     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2298     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2299     option, a class that contained several characters, but with at least one
2300     whose value was between 128 and 255 caused PCRE to crash.
2303 nigel 65 Version 4.1 12-Mar-03
2304     ---------------------
2305 nigel 63
2306 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2307     needed, and a string in dftables.c that was longer than standard compilers are
2308     required to support.
2310     2. Compiling with Sun's compiler found a few more places where the code could
2311     be tidied up in order to avoid warnings.
2313     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2314     first of these names is deprecated in the latest Autoconf in favour of the name
2315     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2316     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2317     analogy I have changed it to CFLAGS_FOR_BUILD.
2319     4. Added -no-undefined to the linking command in the Makefile, because this is
2320     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2321     linking step for the pcreposix library.
2323     5. PCRE was failing to diagnose the case of two named groups with the same
2324     name.
2326     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2327     literal character that is needed in the subject for a match, and scans along to
2328     ensure that it is present before embarking on the full matching process. This
2329     saves time in cases of nested unlimited repeats that are never going to match.
2330     Problem: the scan can take a lot of time if the subject is very long (e.g.
2331     megabytes), thus penalizing straightforward matches. It is now done only if the
2332     amount of subject to be scanned is less than 1000 bytes.
2334     7. A lesser problem with the same optimization is that it was recording the
2335     first character of an anchored pattern as "needed", thus provoking a search
2336     right along the subject, even when the first match of the pattern was going to
2337     fail. The "needed" character is now not set for anchored patterns, unless it
2338     follows something in the pattern that is of non-fixed length. Thus, it still
2339     fulfils its original purpose of finding quick non-matches in cases of nested
2340     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2343     Version 4.0 17-Feb-03
2344     ---------------------
2346 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2347     extended to the end of string, PCRE compiled incorrect data. This could lead to
2348     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2350     2. Moved to autoconf 2.53 and libtool 1.4.2.
2352     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2353     the special perltest8 script is no longer needed - all the tests can be run
2354     from a single perltest script.
2356     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2357     by \s. It has now been removed in PCRE. This means it isn't recognized as
2358     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2359     class [:space:] *does* include VT, thereby creating a mess.
2361     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2362     space and tab.
2364     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2365     its new features into the main test script, reducing the number of scripts.
2367     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2368     were backward compatible, and made the (?i) apply to the whole pattern, as if
2369     /i were given. Now it behaves more logically, and applies the option setting
2370     only to what follows. PCRE has been changed to follow suit. However, if it
2371     finds options settings right at the start of the pattern, it extracts them into
2372     the global options, as before. Thus, they show up in the info data.
2374     8. Added support for the \Q...\E escape sequence. Characters in between are
2375     treated as literals. This is slightly different from Perl in that $ and @ are
2376     also handled as literals inside the quotes. In Perl, they will cause variable
2377     interpolation. Note the following examples:
2379     Pattern PCRE matches Perl matches
2381     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2382     \Qabc\$xyz\E abc\$xyz abc\$xyz
2383     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2385     For compatibility with Perl, \Q...\E sequences are recognized inside character
2386     classes as well as outside them.
2388     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2389     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2390     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2391     signed/unsigned warnings.
2393     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2394     option for pcretest, so I've replaced it by a simple function that does just
2395     that job.
2397     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2398     "pcregrep -".
2400     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2401     Java package. This provides some syntactic sugar for simple cases of what my
2402     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2403     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2404     item, you can use this simplified notation. Note that only makes sense with
2405     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2406     greediness, whatever the setting of the PCRE_UNGREEDY option.
2408     13. A change of greediness default within a pattern was not taking effect at
2409     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2410     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2411     was abstracted outside.
2413     14. PCRE now supports the \G assertion. It is true when the current matching
2414     position is at the start point of the match. This differs from \A when the
2415     starting offset is non-zero. Used with the /g option of pcretest (or similar
2416     code), it works in the same way as it does for Perl's /g option. If all
2417     alternatives of a regex begin with \G, the expression is anchored to the start
2418     match position, and the "anchored" flag is set in the compiled expression.
2420     15. Some bugs concerning the handling of certain option changes within patterns
2421     have been fixed. These applied to options other than (?ims). For example,
2422     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2423     been the other way round. Some of this was related to change 7 above.
2425     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2426     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2427     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2428     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2430     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2431     mode. Unlike ".", it always matches newline, whatever the setting of
2432     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2433     assertions. Perl allows it, but it doesn't (in general) work because it can't
2434     calculate the length of the lookbehind. At least, that's the case for Perl
2435     5.8.0 - I've been told they are going to document that it doesn't work in
2436     future.
2438     18. Added an error diagnosis for escapes that PCRE does not support: these are
2439     \L, \l, \N, \P, \p, \U, \u, and \X.
2441     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2442     reading past the end of the pattern in cases such as /[abcd/.
2444     20. PCRE was getting more memory than necessary for patterns with classes that
2445     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2447     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2448     compiling PCRE for use with Virtual Pascal.
2450     22. Small fix to the Makefile to make it work properly if the build is done
2451     outside the source tree.
2453     23. Added a new extension: a condition to go with recursion. If a conditional
2454     subpattern starts with (?(R) the "true" branch is used if recursion has
2455     happened, whereas the "false" branch is used only at the top level.
2457     24. When there was a very long string of literal characters (over 255 bytes
2458     without UTF support, over 250 bytes with UTF support), the computation of how
2459     much memory was required could be incorrect, leading to segfaults or other
2460     strange effects.
2462     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2463     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2464     there was a subsequent back reference to those brackets. This meant that, for
2465     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2466     possible to check for precisely this case. All we can do is abandon the
2467     optimization if .* occurs inside capturing brackets when there are any back
2468     references whatsoever. (See below for a better fix that came later.)
2470     26. The handling of the optimization for finding the first character of a
2471     non-anchored pattern, and for finding a character that is required later in the
2472     match were failing in some cases. This didn't break the matching; it just
2473     failed to optimize when it could. The way this is done has been re-implemented.
2475     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2477     28. Added a new feature that provides some of the functionality that Perl
2478     provides with (?{...}). The facility is termed a "callout". The way it is done
2479     in PCRE is for the caller to provide an optional function, by setting
2480     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2481     global variable. By default it is unset, which disables all calling out. To get
2482     the function called, the regex must include (?C) at appropriate points. This
2483     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2484     This provides a means of identifying different callout points. When PCRE
2485     reaches such a point in the regex, if pcre_callout has been set, the external
2486     function is called. It is provided with data in a structure called
2487     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2488     matching continues; if it returns a non-zero value, the match at the current
2489     point fails. However, backtracking will occur if possible. [This was changed
2490     later and other features added - see item 49 below.]
2492     29. pcretest is upgraded to test the callout functionality. It provides a
2493     callout function that displays information. By default, it shows the start of
2494     the match and the current position in the text. There are some new data escapes
2495     to vary what happens:
2497     \C+ in addition, show current contents of captured substrings
2498     \C- do not supply a callout function
2499     \C!n return 1 when callout number n is reached
2500     \C!n!m return 1 when callout number n is reached for the mth time
2502     30. If pcregrep was called with the -l option and just a single file name, it
2503     output "<stdin>" if a match was found, instead of the file name.
2505     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2506     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2507     pcre_exec(). This saves a malloc/free per call. The default value of
2508     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2509     when configuring.
2511     32. The default maximum size of a compiled pattern is 64K. There have been a
2512     few cases of people hitting this limit. The code now uses macros to handle the
2513     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2514     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2515     configuring. Tests 2 and 5 work only with 2-byte links because they output
2516     debugging information about compiled patterns.
2518     33. Internal code re-arrangements:
2520     (a) Moved the debugging function for printing out a compiled regex into
2521     its own source file (printint.c) and used #include to pull it into
2522     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2523     separate copies.
2525     (b) Defined the list of op-code names for debugging as a macro in
2526     internal.h so that it is next to the definition of the opcodes.
2528     (c) Defined a table of op-code lengths for simpler skipping along compiled
2529     code. This is again a macro in internal.h so that it is next to the
2530     definition of the opcodes.
2532     34. Added support for recursive calls to individual subpatterns, along the
2533     lines of Robin Houston's patch (but implemented somewhat differently).
2535     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2536     allow it to read and process whole directories in Win32. This code was
2537     contributed by Lionel Fourquaux; it has not been tested by me.
2539     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2540     used to name a group. Names consist of alphanumerics and underscores, and must
2541     be unique. Back references use the syntax (?P=name) and recursive calls use
2542     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2543     numbers. The function pcre_fullinfo() can be used after compilation to extract
2544     a name/number map. There are three relevant calls:
2546     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2547     PCRE_INFO_NAMECOUNT yields the number of entries
2548     PCRE_INFO_NAMETABLE yields a pointer to the map.
2550     The map is a vector of fixed-size entries. The size of each entry depends on
2551     the length of the longest name used. The first two bytes of each entry are the
2552     group number, most significant byte first. There follows the corresponding
2553     name, zero terminated. The names are in alphabetical order.
2555     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2556     case instead of 255. Making it the same both with and without UTF-8 support
2557     means that the same test output works with both.
2559     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2560     calling malloc() with a zero argument.
2562     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2563     optimization. I've improved things by keeping a bitmap of backreferences with
2564     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2565     fact referenced, the optimization can be applied. It is unlikely that a
2566     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2567     the match to follow \n) will appear inside brackets with a number greater than
2568     31, but if it does, any back reference > 31 suppresses the optimization.
2570     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2571     of disabling numbered capturing parentheses. Any opening parenthesis that is
2572     not followed by ? behaves as if it were followed by ?: but named parentheses
2573     can still be used for capturing (and they will acquire numbers in the usual
2574     way).
2576     41. Redesigned the return codes from the match() function into yes/no/error so
2577     that errors can be passed back from deep inside the nested calls. A malloc
2578     failure while inside a recursive subpattern call now causes the
2579     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2581     42. It is now possible to set a limit on the number of times the match()
2582     function is called in a call to pcre_exec(). This facility makes it possible to
2583     limit the amount of recursion and backtracking, though not in a directly
2584     obvious way, because the match() function is used in a number of different
2585     circumstances. The count starts from zero for each position in the subject
2586     string (for non-anchored patterns). The default limit is, for compatibility, a
2587     large number, namely 10 000 000. You can change this in two ways:
2589     (a) When configuring PCRE before making, you can use --with-match-limit=n
2590     to set a default value for the compiled library.
2592     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2593     a different value is set. See 45 below.
2595     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2597     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2598     of things that can be changed at compile time. The first argument specifies
2599     what is wanted and the second points to where the information is to be placed.
2600     The current list of available information is:
2604     The output is an integer that is set to one if UTF-8 support is available;
2605     otherwise it is set to zero.
2609     The output is an integer that it set to the value of the code that is used for
2610     newline. It is either LF (10) or CR (13).
2614     The output is an integer that contains the number of bytes used for internal
2615     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2619     The output is an integer that contains the threshold above which the POSIX
2620     interface uses malloc() for output vectors. See item 31 above.
2624     The output is an unsigned integer that contains the default limit of the number
2625     of match() calls in a pcre_exec() execution. See 42 above.
2627     44. pcretest has been upgraded by the addition of the -C option. This causes it
2628     to extract all the available output from the new pcre_config() function, and to
2629     output it. The program then exits immediately.
2631     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2632     order to support additional features. One way would have been to define
2633     pcre_exec2() (for example) with extra arguments, but this would not have been
2634     extensible, and would also have required all calls to the original function to
2635     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2636     is used for passing in "extra" data from pcre_study().
2638     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2639     contains the following fields:
2641     flags a bitmap indicating which of the following fields are set
2642     study_data opaque data from pcre_study()
2643     match_limit a way of specifying a limit on match() calls for a specific
2644     call to pcre_exec()
2645     callout_data data for callouts (see 49 below)
2647     The flag bits are also defined in pcre.h, and are
2653     The pcre_study() function now returns one of these new pcre_extra blocks, with
2654     the actual study data pointed to by the study_data field, and the
2655     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2656     before. That is, this change is entirely upwards-compatible and requires no
2657     change to existing code.
2659     If you want to pass in additional data to pcre_exec(), you can either place it
2660     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2661     block.
2663     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2664     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2665     times with different match limits, until it finds the minimum value needed for
2666     pcre_exec() to complete. The value is then output. This can be instructive; for
2667     most simple matches the number is quite small, but for pathological cases it
2668     gets very large very quickly.
2670     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2671     returns the size of the data block pointed to by the study_data field in a
2672     pcre_extra block, that is, the value that was passed as the argument to
2673     pcre_malloc() when PCRE was getting memory in which to place the information
2674     created by pcre_study(). The fourth argument should point to a size_t variable.
2675     pcretest has been extended so that this information is shown after a successful
2676     pcre_study() call when information about the compiled regex is being displayed.
2678     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2679     because what follows is always an absolute path. (Later: it turns out that this
2680     is more than cosmetic for MinGW, because it doesn't like empty path
2681     components.)
2683     49. Some changes have been made to the callout feature (see 28 above):
2685     (i) A callout function now has three choices for what it returns:
2687     0 => success, carry on matching
2688     > 0 => failure at this point, but backtrack if possible
2689     < 0 => serious error, return this value from pcre_exec()
2691     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2692     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2693     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2694     use by callout functions. It will never be used by PCRE itself.
2696     (ii) The pcre_extra structure (see 45 above) has a void * field called
2697     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2698     pcre_callout_block structure has a field of the same name. The contents of
2699     the field passed in the pcre_extra structure are passed to the callout
2700     function in the corresponding field in the callout block. This makes it
2701     easier to use the same callout-containing regex from multiple threads. For
2702     testing, the pcretest program has a new data escape
2704     \C*n pass the number n (may be negative) as callout_data
2706     If the callout function in pcretest receives a non-zero value as
2707     callout_data, it returns that value.
2709     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2710     there were some redundant $(CFLAGS) in commands that are now specified as
2711     $(LINK), which already includes $(CFLAGS).
2713     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2714     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2715     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2716     one-byte characters throughout. Note that case-insensitive matching applies
2717     only to characters whose values are less than 256. PCRE doesn't support the
2718     notion of cases for higher-valued characters.
2720     (i) A character class whose characters are all within 0-255 is handled as
2721     a bit map, and the map is inverted for negative classes. Previously, a
2722     character > 255 always failed to match such a class; however it should
2723     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2725     (ii) A negated character class with a single character < 255 is coded as
2726     "not this character" (OP_NOT). This wasn't working properly when the test
2727     character was multibyte, either singly or repeated.
2729     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2730     mode, for example: \x{100}{2,3}.
2732     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2733     singly or repeated) now correctly test multibyte characters. However,
2734     PCRE doesn't recognize any characters with values greater than 255 as
2735     digits, spaces, or word characters. Such characters always match \D, \S,
2736     and \W, and never match \d, \s, or \w.
2738     (v) Classes may now contain characters and character ranges with values
2739     greater than 255. For example: [ab\x{100}-\x{400}].
2741     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2742     PCRE in UTF-8 mode.
2744     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2745     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2746     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2747     value.)
2749     53. The single man page has become too large. I have therefore split it up into
2750     a number of separate man pages. These also give rise to individual HTML pages;
2751     these are now put in a separate directory, and there is an index.html page that
2752     lists them all. Some hyperlinking between the pages has been installed.
2754     54. Added convenience functions for handling named capturing parentheses.
2756     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2757     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2758     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2759     are faulted.
2761     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2762     calling configure. These values are used when compiling the dftables.c program
2763     which is run to generate the source of the default character tables. They
2764     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2765     you will need to set these values.
2767     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2770     Version 3.9 02-Jan-02
2771 nigel 61 ---------------------
2773     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2775     2. If --disable-static was given, the building process failed when trying to
2776     build pcretest and pcregrep. (For some reason it was using libtool to compile
2777     them, which is not right, as they aren't part of the library.)
2780 nigel 59 Version 3.8 18-Dec-01
2781     ---------------------
2783     1. The experimental UTF-8 code was completely screwed up. It was packing the
2784     bytes in the wrong order. How dumb can you get?
2787 nigel 57 Version 3.7 29-Oct-01
2788     ---------------------
2790     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2791     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2792     this didn't happen under Solaris 8, where I normally test things.
2794 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2795     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2796     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2797     this fix an hour or so after the initial 3.7 release.)
2798 nigel 57
2799 nigel 59
2800 nigel 55 Version 3.6 23-Oct-01
2801     ---------------------
2803     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2804     offsets passed as NULL with zero offset count.
2806     2. The config.guess and config.sub files had not been updated when I moved to
2807     the latest autoconf.
2810 nigel 53 Version 3.5 15-Aug-01
2811     ---------------------
2812 nigel 5
2813 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2814     had been forgotten.
2816     2. By using declared but undefined structures, we can avoid using "void"
2817     definitions in pcre.h while keeping the internal definitions of the structures
2818     private.
2820     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2821     user point of view, this means that both static and shared libraries are built
2822     by default, but this can be individually controlled. More of the work of
2823     handling this static/shared cases is now inside libtool instead of PCRE's make
2824     file.
2826     4. The pcretest utility is now installed along with pcregrep because it is
2827     useful for users (to test regexs) and by doing this, it automatically gets
2828     relinked by libtool. The documentation has been turned into a man page, so
2829     there are now .1, .txt, and .html versions in /doc.
2831     5. Upgrades to pcregrep:
2832     (i) Added long-form option names like gnu grep.
2833     (ii) Added --help to list all options with an explanatory phrase.
2834     (iii) Added -r, --recursive to recurse into sub-directories.
2835     (iv) Added -f, --file to read patterns from a file.
2837     6. pcre_exec() was referring to its "code" argument before testing that
2838     argument for NULL (and giving an error if it was NULL).
2840     7. Upgraded Makefile.in to allow for compiling in a different directory from
2841     the source directory.
2843     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2844     options bits, the pointer it was passed was to an int instead of to an unsigned
2845     long int. This mattered only on 64-bit systems.
2847     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2848     generated) instead of pcre.in, which it its source. Also made the same change
2849     in several of the .c files.
2851     10. A new release of gcc defines printf() as a macro, which broke pcretest
2852     because it had an ifdef in the middle of a string argument for printf(). Fixed
2853     by using separate calls to printf().
2855     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2856     script, to force use of CR or LF instead of \n in the source. On non-Unix
2857     systems, the value can be set in config.h.
2859     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2860     absolute limit. Changed the text of the error message to make this clear, and
2861     likewise updated the man page.
2863     13. The limit of 99 on the number of capturing subpatterns has been removed.
2864     The new limit is 65535, which I hope will not be a "real" limit.
2867 nigel 51 Version 3.4 22-Aug-00
2868     ---------------------
2870     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2872     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2875 nigel 49 Version 3.3 01-Aug-00
2876     ---------------------
2878     1. If an octal character was given, but the value was greater than \377, it
2879     was not getting masked to the least significant bits, as documented. This could
2880     lead to crashes in some systems.
2882     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2883     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2885     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2886     These just pass their arguments on to (pcre_free)(), but they are provided
2887     because some uses of PCRE bind it to non-C systems that can call its functions,
2888     but cannot call free() or pcre_free() directly.
2890     4. Add "make test" as a synonym for "make check". Corrected some comments in
2891     the Makefile.
2893     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2894     Makefile.
2896     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2897     command called pgrep for grepping around the active processes.
2899     7. Added the beginnings of support for UTF-8 character strings.
2901     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2902     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2903     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2904     out for the ar command.)
2907 nigel 47 Version 3.2 12-May-00
2908     ---------------------
2910     This is purely a bug fixing release.
2912     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2913     of ZA. This was just one example of several cases that could provoke this bug,
2914     which was introduced by change 9 of version 2.00. The code for breaking
2915     infinite loops after an iteration that matches an empty string was't working
2916     correctly.
2918     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2919     when matched against abbab (for example). After matching an empty string, it
2920     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2921     caused it to match further down the string than it should.
2923     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2924     was there because it doesn't seem to be needed, and it causes trouble on some
2925     systems, as it is not a Standard C header. It has been removed.
2927     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2928     were reported on the Macintosh. The changes were from
2930     while ((c = *(++ptr)) != 0 && c != '\n');
2931     to
2932     while ((c = *(++ptr)) != 0 && c != '\n') ;
2934     Totally extraordinary, but if that's what it takes...
2936     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2937     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2938     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2939     assumes the way PCRE uses memmove() (always moving upwards).
2941     6. PCRE is being used in one environment where strchr() is not available. There
2942     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2943     faster code anyway.
2946 nigel 45 Version 3.1 09-Feb-00
2947     ---------------------
2949     The only change in this release is the fixing of some bugs in Makefile.in for
2950     the "install" target:
2952     (1) It was failing to install pcreposix.h.
2954     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2957 nigel 43 Version 3.0 01-Feb-00
2958     ---------------------
2959 nigel 41
2960     1. Add support for the /+ modifier to perltest (to output $` like it does in
2961     pcretest).
2963     2. Add support for the /g modifier to perltest.
2965     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2966     matches null strings.
2968     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2969     pattern. Perl treats empty patterns specially - it reuses the most recent
2970     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2971     effect.
2973     5. The POSIX interface was broken in that it was just handing over the POSIX
2974     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2975     required a bigger vector, with some working space on the end. This means that
2976     the POSIX wrapper now has to get and free some memory, and copy the results.
2978 nigel 43 6. Added some simple autoconf support, placing the test data and the
2979     documentation in separate directories, re-organizing some of the
2980     information files, and making it build pcre-config (a GNU standard). Also added
2981     libtool support for building PCRE as a shared library, which is now the
2982     default.
2983 nigel 41
2984 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2985     09 are not valid octal constants. Single digits will be used for minor values
2986     less than 10.
2988     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2989     existing programs that set these in the POSIX interface can use PCRE without
2990     modification.
2992     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2993     return all that pcre_info() returns, plus additional data. The pcre_info()
2994     function is retained for compatibility, but is considered to be obsolete.
2996     10. Added experimental recursion feature (?R) to handle one common case that
2997     Perl 5.6 will be able to do with (?p{...}).
2999     11. Added support for POSIX character classes like [:alpha:], which Perl is
3000     adopting.
3003 nigel 39 Version 2.08 31-Aug-99
3004     ----------------------
3006     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3007     trying to match at the startoffset position, but instead was moving forward to
3008     the next newline as if a previous match had failed.
3010     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3011     and could get into a loop if a null string was matched other than at the start
3012     of the subject.
3014     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3015     be distinguished at compile time, and for completeness also added PCRE_DATE.
3017     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3018     in GnuWin32 environments.
3021 nigel 37 Version 2.07 29-Jul-99
3022     ----------------------
3024     1. The documentation is now supplied in plain text form and HTML as well as in
3025     the form of man page sources.
3027     2. C++ compilers don't like assigning (void *) values to other pointer types.
3028     In particular this affects malloc(). Although there is no problem in Standard
3029     C, I've put in casts to keep C++ compilers happy.
3031     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3032     should be (const char *).
3034     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3035     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3036     However, I haven't made this a standard facility. The documentation doesn't
3037     mention it, and the Makefile doesn't support it.
3039     5. The Makefile now contains an "install" target, with editable destinations at
3040     the top of the file. The pcretest program is not installed.
3042     6. pgrep -V now gives the PCRE version number and date.
3044     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3045     causing the entire string to be ignored, instead of just the last character.
3047     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3048     non-matching string, it can take a very, very long time, even for strings of
3049     quite modest length, because of the nested recursion. PCRE now does better in
3050     some of these cases. It does this by remembering the last required literal
3051     character in the pattern, and pre-searching the subject to ensure it is present
3052     before running the real match. In other words, it applies a heuristic to detect
3053     some types of certain failure quickly, and in the above example, if presented
3054     with a string that has no trailing " it gives "no match" very quickly.
3056     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3057     other alternatives are tried instead.
3060 nigel 35 Version 2.06 09-Jun-99
3061     ----------------------
3063     1. Change pcretest's output for amount of store used to show just the code
3064     space, because the remainder (the data block) varies in size between 32-bit and
3065     64-bit systems.
3067     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3068     start matching at. This allows lookbehinds to work when searching for multiple
3069     occurrences in a string.
3071     3. Added additional options to pcretest for testing multiple occurrences:
3073     /+ outputs the rest of the string that follows a match
3074     /g loops for multiple occurrences, using the new startoffset argument
3075     /G loops for multiple occurrences by passing an incremented pointer
3077     4. PCRE wasn't doing the "first character" optimization for patterns starting
3078     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3079     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3080     the letter 'x'. On long subject strings, this gives a significant speed-up.
3083 nigel 33 Version 2.05 21-Apr-99
3084     ----------------------
3086     1. Changed the type of magic_number from int to long int so that it works
3087     properly on 16-bit systems.
3089     2. Fixed a bug which caused patterns starting with .* not to work correctly
3090     when the subject string contained newline characters. PCRE was assuming
3091     anchoring for such patterns in all cases, which is not correct because .* will
3092     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3093     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3094     must be retried after every newline in the subject.
3097 nigel 31 Version 2.04 18-Feb-99
3098     ----------------------
3100     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3101     computation of the store needed to hold the pattern was incorrect (too large).
3102     If such patterns were nested a few deep, this could multiply and become a real
3103     problem.
3105     2. Added /M option to pcretest to show the memory requirement of a specific
3106     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3108     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3109     compiled in such a way that the backtracking after subsequent failure was
3110     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3111     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3114 nigel 29 Version 2.03 02-Feb-99
3115     ----------------------
3117     1. Fixed typo and small mistake in man page.
3119 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3120     LICENCE file containing the conditions.
3121 nigel 29
3122     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3123     Perl, that is the internal \ allows the delimiter to be included in the
3124     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3125     the final delimiter, add \ to the end of the pattern (to test the error).
3127     4. Added the convenience functions for extracting substrings after a successful
3128     match. Updated pcretest to make it able to test these functions.
3131 nigel 27 Version 2.02 14-Jan-99
3132     ----------------------
3134     1. Initialized the working variables associated with each extraction so that
3135     their saving and restoring doesn't refer to uninitialized store.
3137     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3138     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3139     fix the problem.
3141     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3142     calls, and wasn't printing the correct value for compiling calls. Increased the
3143     default value of LOOPREPEAT, and the number of significant figures in the
3144     times.
3146     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3148     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3149     a building problem on Windows NT with a FAT file system.
3152 nigel 25 Version 2.01 21-Oct-98
3153     ----------------------
3155     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3156     to character tables built by pcre_maketables() in the current locale. If NULL
3157     is passed, the default tables are used.
3160 nigel 23 Version 2.00 24-Sep-98
3161 nigel 21 ----------------------
3163 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3164     it any more.
3166     2. Allow quantification of (?>) groups, and make it work correctly.
3168     3. The first character computation wasn't working for (?>) groups.
3170     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3171     end of the subject) and add 5.005's \z, which really does match only at the
3172     very end of the subject.
3174     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3176     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3177     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3178     localized options. All options to pcre_study() were also removed.
3180     7. Add other new features from 5.005:
3182     $(?<= positive lookbehind
3183     $(?<! negative lookbehind
3184     (?imsx-imsx) added the unsetting capability
3185     such a setting is global if at outer level; local otherwise
3186     (?imsx-imsx:) non-capturing groups with option setting
3187     (?(cond)re|re) conditional pattern matching
3189     A backreference to itself in a repeated group matches the previous
3190     captured string.
3192     8. General tidying up of studying (both automatic and via "study")
3193     consequential on the addition of new assertions.
3195     9. As in 5.005, unlimited repeated groups that could match an empty substring
3196     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3197     runtime if any iteration does actually match an empty substring.
3199     10. Include the RunTest script in the distribution.
3201     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3202     discrepancies, some of which were old and were also with respect to 5.004. They
3203     have now been fixed.
3206     Version 1.09 28-Apr-98
3207     ----------------------
3209 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3210     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3211     program crashes, or just wrong answers. This did not apply to negated classes
3212     containing more than one character, or to minima other than one.
3215 nigel 19 Version 1.08 27-Mar-98
3216     ----------------------
3218     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3220     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3221     latter must appear before anything that relies on it in the pattern.
3224 nigel 17 Version 1.07 16-Feb-98
3225     ----------------------
3227     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3228     repeat of a potentially empty string).
3231 nigel 15 Version 1.06 23-Jan-98
3232     ----------------------
3234     1. Added Markus Oberhumer's little patches for C++.
3236     2. Literal strings longer than 255 characters were broken.
3239 nigel 13 Version 1.05 23-Dec-97
3240     ----------------------
3242     1. Negated character classes containing more than one character were failing if
3243     PCRE_CASELESS was set at run time.
3246 nigel 11 Version 1.04 19-Dec-97
3247     ----------------------
3249     1. Corrected the man page, where some "const" qualifiers had been omitted.
3251     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3252     input syntax.
3254     3. Fixed memory leak which occurred when a regex with back references was
3255     matched with an offsets vector that wasn't big enough. The temporary memory
3256     that is used in this case wasn't being freed if the match failed.
3258     4. Tidied pcretest to ensure it frees memory that it gets.
3260     5. Temporary memory was being obtained in the case where the passed offsets
3261     vector was exactly big enough.
3263     6. Corrected definition of offsetof() from change 5 below.
3265     7. I had screwed up change 6 below and broken the rules for the use of
3266     setjmp(). Now fixed.
3269 nigel 9 Version 1.03 18-Dec-97
3270     ----------------------
3272     1. A erroneous regex with a missing opening parenthesis was correctly
3273     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3274     on some systems.
3276     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3277     it was reported that one broken compiler failed on the former because "code" is
3278     also an independent variable.
3280     3. The erroneous regex a[]b caused an array overrun reference.
3282     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3283     fail on data ending with that character. (It was going on too far, and checking
3284     the next character, typically a binary zero.) This was specific to the
3285     optimized code for single-character negative classes.
3287     5. Added a contributed patch from the TIN world which does the following:
3289     + Add an undef for memmove, in case the the system defines a macro for it.
3291     + Add a definition of offsetof(), in case there isn't one. (I don't know
3292     the reason behind this - offsetof() is part of the ANSI standard - but
3293     it does no harm).
3295     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3296     most of the places where whitespace preceded '#'. I have given up and
3297     allowed the remaining 2 cases to be at the margin.
3299     + Rename some variables in pcre to eliminate shadowing. This seems very
3300     pedantic, but does no harm, of course.
3302     6. Moved the call to setjmp() into its own function, to get rid of warnings
3303     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3305     7. Constructs such as \d{8,} were compiling into the equivalent of
3306 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3307 nigel 9 outcome, but in this particular case used more store than had been allocated,
3308     which caused the bug to be discovered because it threw up an internal error.
3310     8. The debugging code in both pcre and pcretest for outputting the compiled
3311     form of a regex was going wrong in the case of back references followed by
3312     curly-bracketed repeats.
3315 nigel 7 Version 1.02 12-Dec-97
3316     ----------------------
3318     1. Typos in pcre.3 and comments in the source fixed.
3320     2. Applied a contributed patch to get rid of places where it used to remove
3321     'const' from variables, and fixed some signed/unsigned and uninitialized
3322     variable warnings.
3324     3. Added the "runtest" target to Makefile.
3326     4. Set default compiler flag to -O2 rather than just -O.
3329 nigel 5 Version 1.01 19-Nov-97
3330     ----------------------
3332     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3333     like /([ab]*)*/, that is, for classes with more than one character in them.
3335     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3336     as /((?>a*))*/ (a PCRE_EXTRA facility).
3339     Version 1.00 18-Nov-97
3340     ----------------------
3342     1. Added compile-time macros to support systems such as SunOS4 which don't have
3343     memmove() or strerror() but have other things that can be used instead.
3345     2. Arranged that "make clean" removes the executables.
3348 nigel 3 Version 0.99 27-Oct-97
3349     ----------------------
3351     1. Fixed bug in code for optimizing classes with only one character. It was
3352     initializing a 32-byte map regardless, which could cause it to run off the end
3353     of the memory it had got.
3355     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3358     Version 0.98 22-Oct-97
3359     ----------------------
3361     1. Fixed bug in code for handling temporary memory usage when there are more
3362     back references than supplied space in the ovector. This could cause segfaults.
3365     Version 0.97 21-Oct-97
3366     ----------------------
3368     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3370     2. Optimized negated single characters not to use a bit map.
3372     3. Brought error texts together as macro definitions; clarified some of them;
3373     fixed one that was wrong - it said "range out of order" when it meant "invalid
3374     escape sequence".
3376     4. Changed some char * arguments to const char *.
3378     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3380     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3381     pcretest.
3384     Version 0.96 16-Oct-97
3385     ----------------------
3387     1. Added a simple "pgrep" utility to the distribution.
3389     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3390     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3391     where "ddd" means "one or more decimal digits".
3393     3. Fixed serious bug. If a pattern had a back reference, but the call to
3394     pcre_exec() didn't supply a large enough ovector to record the related
3395     identifying subpattern, the match always failed. PCRE now remembers the number
3396     of the largest back reference, and gets some temporary memory in which to save
3397     the offsets during matching if necessary, in order to ensure that
3398     backreferences always work.
3400     4. Increased the compatibility with Perl in a number of ways:
3402     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3403     to request this handling. The option can be set at compile or exec time.
3405     (b) $ matches before a terminating newline by default; an option
3406     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3407     mode). The option can be set at compile or exec time.
3409     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3410     the same as Perl's. If the decimal number it represents is less than 10
3411     or there aren't that many previous left capturing parentheses, an octal
3412     escape is read. Inside a character class, it's always an octal escape,
3413     even if it is a single digit.
3415     (d) An escaped but undefined alphabetic character is taken as a literal,
3416     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3417     escapes.
3419     (e) {0} is now permitted. (The previous item is removed from the compiled
3420     pattern).
3422     5. Changed all the names of code files so that the basic parts are no longer
3423     than 10 characters, and abolished the teeny "globals.c" file.
3425     6. Changed the handling of character classes; they are now done with a 32-byte
3426     bit map always.
3428     7. Added the -d and /D options to pcretest to make it possible to look at the
3429     internals of compilation without having to recompile pcre.
3432     Version 0.95 23-Sep-97
3433     ----------------------
3435     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3436     \x20 at the start of a run of normal characters. These were being treated as
3437     real characters, instead of the source characters being re-checked.
3440     Version 0.94 18-Sep-97
3441     ----------------------
3443     1. The functions are now thread-safe, with the caveat that the global variables
3444     containing pointers to malloc() and free() or alternative functions are the
3445     same for all threads.
3447     2. Get pcre_study() to generate a bitmap of initial characters for non-
3448     anchored patterns when this is possible, and use it if passed to pcre_exec().
3451     Version 0.93 15-Sep-97
3452     ----------------------
3454     1. /(b)|(:+)/ was computing an incorrect first character.
3456     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3457     but not actually doing anything yet.
3459     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3460     as Perl does (e.g. [-az] or [az-]).
3462     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3463     all possible positions.
3465     5. Split up into different modules to avoid including unneeded functions in a
3466     compiled binary. However, compile and exec are still in one module. The "study"
3467     function is split off.
3469     6. The character tables are now in a separate module whose source is generated
3470     by an auxiliary program - but can then be edited by hand if required. There are
3471     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3472     toupper() in the code.
3474     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3475     make them global. Abolish the function for setting them, as the caller can now
3476     set them directly.
3479     Version 0.92 11-Sep-97
3480     ----------------------
3482     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3483     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3485     2. Caseless matching was not working in character classes if the characters in
3486     the pattern were in upper case.
3488     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3490     4. Make PCRE_ANCHORED public and accept as a compile option.
3492     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3493     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3494     pass them.
3496     6. Give an error if bad option bits passed at compile or run time.
3498     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3499     pcretest to cause it to pass that flag.
3501     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3502     options, and the first character, if set.
3504     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3507     Version 0.91 10-Sep-97
3508     ----------------------
3510     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3511     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3513     2. PCRE was looping on encountering an indefinitely repeated back reference to
3514     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3515     Perl does - treats the match as successful.
3517     ****


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