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Revision 428 - (hide annotations) (download)
Mon Aug 31 17:10:26 2009 UTC (5 years, 1 month ago) by ph10
File size: 169567 byte(s)
Further partial match change: add PCRE_PARTIAL_HARD and make more intuitive.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 418 Version 8.00 ??-???-??
5     ----------------------
6    
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8     was out-of-date, and there was no check on the pcre_compile() error code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.
11 ph10 419
12     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
13     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
14     in a Windows environment.
15 ph10 420
16     3. The pcregrep --count option prints the count for each file even when it is
17     zero, as does GNU grep. However, pcregrep was also printing all files when
18     --files-with-matches was added. Now, when both options are given, it prints
19     counts only for those files that have at least one match. (GNU grep just
20     prints the file name in this circumstance, but including the count seems
21     more useful - otherwise, why use --count?) Also ensured that the
22     combination -clh just lists non-zero counts, with no names.
23    
24 ph10 421 4. The long form of the pcregrep -F option was incorrectly implemented as
25     --fixed_strings instead of --fixed-strings. This is an incompatible change,
26     but it seems right to fix it, and I didn't think it was worth preserving
27     the old behaviour.
28    
29 ph10 422 5. The command line items --regex=pattern and --regexp=pattern were not
30     recognized by pcregrep, which required --regex pattern or --regexp pattern
31     (with a space rather than an '='). The man page documented the '=' forms,
32     which are compatible with GNU grep; these now work.
33    
34 ph10 423 6. No libpcreposix.pc file was created for pkg-config; there was just
35     libpcre.pc and libpcrecpp.pc. The omission has been rectified.
36    
37 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
38     when UCP support is not needed, by modifying the Python script that
39     generates it from Unicode data files. This should not matter if the module
40     is correctly used as a library, but I received one complaint about 50K of
41     unwanted data. My guess is that the person linked everything into his
42     program rather than using a library. Anyway, it does no harm.
43    
44 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
45     was a minimum greater than 1 for a wide character in a possessive
46     repetition. Chaos could result.
47    
48     9. The restrictions on what a pattern can contain when partial matching is
49     requested for pcre_exec() have been removed. All patterns can now be
50     partially matched by this function. In addition, if there are at least two
51     slots in the offset vector, the offsets of the first-encountered partial
52     match are set in them when PCRE_ERROR_PARTIAL is returned.
53    
54 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
55     synonymous with PCRE_PARTIAL, for backwards compatibility, and
56     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
57     and may be more useful for multi-segment matching, especially with
58     pcre_exec().
59 ph10 427
60 ph10 428 11. Partial matching with pcre_exec() is now more intuitive. A partial match
61     used to be given if ever the end of the subject was reached; now it is
62     given only if matching could not proceed because another character was
63     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
64     string "Z", which now yields "no match" instead of "partial match". In the
65     case of pcre_dfa_exec(), "no match" is given if every matching path for the
66     final character ended with (*FAIL).
67    
68     12. Restarting a match using pcre_dfa_exec() after a partial match did not work
69     if the pattern had a "must contain" character that was already found in the
70     earlier partial match, unless partial matching was again requested. For
71     example, with the pattern /dog.(body)?/, the "must contain" character is
72     "g". If the first part-match was for the string "dog", restarting with
73     "sbody" failed.
74    
75 ph10 418
76 ph10 412 Version 7.9 11-Apr-09
77 ph10 376 ---------------------
78    
79 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
80 ph10 376 (pcretest), all targets were linked against these libraries. This included
81     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
82     libraries. This caused unwanted dependencies to be created. This problem
83 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
84 ph10 376 pcretest is linked with readline.
85 ph10 392
86 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
87     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
88     moved outside it again, because FALSE and TRUE are already defined in AIX,
89     but BOOL is not.
90 ph10 392
91     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
92 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
93 ph10 392
94 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
95     hyphens) following file names and line numbers when outputting matching
96 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
97 ph10 376 wording for the --colour (or --color) option.
98 ph10 392
99 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
100     was not coloured; this is different to GNU grep, so I have changed it to be
101     the same.
102 ph10 392
103 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
104 ph10 392 each matching line was coloured. Now it goes on to look for further matches
105     of any of the test patterns, which is the same behaviour as GNU grep.
106    
107     7. A pattern that could match an empty string could cause pcregrep to loop; it
108     doesn't make sense to accept an empty string match in pcregrep, so I have
109 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
110     seems to be how GNU grep behaves.
111 ph10 392
112 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
113 ph10 392 start or after a newline", because the conditional assertion was not being
114     correctly handled. The rule now is that both the assertion and what follows
115     in the first alternative must satisfy the test.
116    
117 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
118 ph10 399 condition was an assertion, PCRE could crash during matching, both with
119     pcre_exec() and pcre_dfa_exec().
120 ph10 392
121     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
122     used for matching.
123    
124     11. Unicode property support in character classes was not working for
125 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
126 ph10 388
127 ph10 392 12. Added the -M command line option to pcretest.
128    
129 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
130 ph10 389
131     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
132 ph10 390
133 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
134 ph10 390 wrapper.
135 ph10 392
136 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
137 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
138 ph10 391 string constants.
139 ph10 405
140 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
141     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
142 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
143     these, but not everybody uses configure.
144    
145     19. A conditional group that had only one branch was not being correctly
146     recognized as an item that could match an empty string. This meant that an
147     enclosing group might also not be so recognized, causing infinite looping
148     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
149     with the subject "ab", where knowledge that the repeated group can match
150 ph10 396 nothing is needed in order to break the loop.
151 ph10 405
152 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
153 ph10 405 exec(), but without supplying a callout function, matching went wrong.
154    
155     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
156     leak if the size of the offset vector was greater than 30. When the vector
157     is smaller, the saved offsets during recursion go onto a local stack
158     vector, but for larger vectors malloc() is used. It was failing to free
159     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
160 ph10 400 error, in fact).
161 ph10 405
162 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
163 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
164     problem, but was untidy.
165 ph10 376
166 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
167     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
168     included within another project.
169 ph10 411
170 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
171     slightly modified by me:
172 ph10 411
173     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
174     not building pcregrep.
175    
176 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
177 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
178    
179 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
180     duplicate group numbers, could behave incorrectly or give incorrect errors,
181     because when scanning forward to find the reference group, PCRE was not
182     taking into account the duplicate group numbers. A pattern such as
183     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
184 ph10 411
185     26. Changed a few more instances of "const unsigned char *" to USPTR, making
186     the feature of a custom pointer more persuasive (as requested by a user).
187 ph10 416
188 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
189 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
190     pre-defined.
191 ph10 392
192 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
193    
194 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
195     in the configuration summary.
196 ph10 405
197 ph10 411
198 ph10 374 Version 7.8 05-Sep-08
199 ph10 349 ---------------------
200    
201     1. Replaced UCP searching code with optimized version as implemented for Ad
202     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
203 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
204     to 5 times on some simple patterns that I tested. Permission was given to
205     distribute the MultiStage2.py script that generates the tables (it's not in
206     the tarball, but is in the Subversion repository).
207 ph10 349
208 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
209     scripts.
210 ph10 358
211 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
212     a group with a zero qualifier. The result of the study could be incorrect,
213 ph10 358 or the function might crash, depending on the pattern.
214    
215     4. Caseless matching was not working for non-ASCII characters in back
216 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
217 ph10 358 It now works when Unicode Property Support is available.
218    
219 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
220     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
221     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
222 ph10 358 truncation.
223 ph10 349
224 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
225    
226 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
227     pointers, in case they are 64-bit values.
228 ph10 371
229     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
230     test 2 if it fails.
231    
232 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
233 ph10 371 and a #define of that name to empty if it is not externally set. This is to
234     allow users of MSVC to set it if necessary.
235    
236     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
237 ph10 359 the convenience functions in the pcre_get.c source file.
238 ph10 371
239 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
240     could cause overwriting and/or a crash. This command provoked a crash in
241 ph10 371 some environments:
242    
243     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
244    
245 ph10 360 This potential security problem was recorded as CVE-2008-2371.
246 ph10 371
247 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
248     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
249 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
250 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
251     pcretest so that it places the subject at the end of its malloc-ed buffer.
252 ph10 371
253 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
254 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
255    
256 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
257 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
258     first line. This applied both to normal and DFA matching.
259    
260 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
261 ph10 371 /^[^d]*?$/8 failed to match "abc".
262 ph10 351
263 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
264    
265     17. Make it more clear in the documentation that values returned from
266 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
267 ph10 357
268 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
269 ph10 368
270 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
271     supplied by Stefan Weber. I made a further small update for 7.8 because
272 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
273     replaced by pcre_ucd.c.
274 ph10 371
275 ph10 373
276 ph10 347 Version 7.7 07-May-08
277 ph10 321 ---------------------
278    
279     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
280 ph10 345 a string to a long long, pretend we don't even have a long long." This is
281 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
282 ph10 345
283 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
284     pre-7.6 versions, which defined a global no_arg variable instead of putting
285 ph10 332 it in the RE class. (See also #8 below.)
286 ph10 345
287     3. Remove a line of dead code, identified by coverity and reported by Nuno
288     Lopes.
289    
290 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
291 ph10 321
292 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
293 ph10 345 of files, instead of just to the final components.
294    
295 ph10 324 (2) If there was more than one level of directory, the subdirectories were
296     skipped unless they satisfied the include/exclude conditions. This is
297     inconsistent with GNU grep (and could even be seen as contrary to the
298     pcregrep specification - which I improved to make it absolutely clear).
299     The action now is always to scan all levels of directory, and just
300     apply the include/exclude patterns to regular files.
301 ph10 345
302 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
303 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
304    
305 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
306 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
307 ph10 326 doesn't support NULs in patterns.
308 ph10 345
309     7. Added some missing "const"s to declarations of static tables in
310     pcre_compile.c and pcre_dfa_exec.c.
311    
312 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
313 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
314 ph10 345 first patch. And a third patch - this was a messy problem.)
315 ph10 321
316 ph10 345 9. Applied Craig's patch to remove the use of push_back().
317    
318 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
319     matching function regexec().
320 ph10 345
321     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
322     which, however, unlike Perl's \g{...}, are subroutine calls, not back
323 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
324     Oniguruma does).
325 ph10 345
326     12. Previously, a group with a zero repeat such as (...){0} was completely
327 ph10 335 omitted from the compiled regex. However, this means that if the group
328     was called as a subroutine from elsewhere in the pattern, things went wrong
329 ph10 345 (an internal error was given). Such groups are now left in the compiled
330     pattern, with a new opcode that causes them to be skipped at execution
331 ph10 335 time.
332 ph10 345
333 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
334     to the way PCRE behaves:
335 ph10 345
336 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
337 ph10 345
338     (b) A back reference to an unmatched subpattern matches an empty string
339 ph10 336 (Perl fails the current match path).
340 ph10 345
341 ph10 341 (c) A data ] in a character class must be notated as \] because if the
342 ph10 345 first data character in a class is ], it defines an empty class. (In
343 ph10 341 Perl it is not possible to have an empty class.) The empty class []
344     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
345     The negative empty class [^] matches any one character, independently
346     of the DOTALL setting.
347 ph10 345
348     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
349 ph10 340 non-existent subpattern following a character class starting with ']' and
350     containing () gave an internal compiling error instead of "reference to
351     non-existent subpattern". Fortunately, when the pattern did exist, the
352 ph10 345 compiled code was correct. (When scanning forwards to check for the
353 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
354 ph10 345 the class, so got the count wrong. When actually compiling, the reference
355 ph10 340 was subsequently set up correctly.)
356 ph10 345
357 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
358 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
359     other assertions are supported. I have made pcre_dfa_exec() support
360     (*FAIL).
361    
362 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
363 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
364     cannot be changed at match time, I realized I could make a small
365     improvement to matching performance by compiling OP_ALLANY instead of
366     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
367     on the OP_ANY path.
368    
369     17. Compiling pcretest on Windows with readline support failed without the
370 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
371 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
372    
373 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
374 ph10 345 ncurses library to be included for pcretest when ReadLine support is
375     requested, but also to allow for it to be overridden. This patch came from
376     Daniel Bergström.
377 ph10 347
378 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
379 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
380     any errors with the current Unicode tables. Thanks to Peter Kankowski for
381     spotting this.
382 ph10 324
383 ph10 332
384 ph10 319 Version 7.6 28-Jan-08
385 ph10 300 ---------------------
386    
387 ph10 302 1. A character class containing a very large number of characters with
388     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
389     overflow.
390 ph10 309
391     2. Patch to cut out the "long long" test in pcrecpp_unittest when
392     HAVE_LONG_LONG is not defined.
393    
394 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
395 ph10 304 bring them up to date and include new features. This patch includes:
396 ph10 309
397 ph10 304 - Fixed PH's badly added libz and libbz2 support.
398     - Fixed a problem with static linking.
399 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
400 ph10 304 - Fixed dftables problem and added an option.
401     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
402     HAVE_LONG_LONG.
403     - Added readline support for pcretest.
404 ph10 309 - Added an listing of the option settings after cmake has run.
405    
406 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
407     "pcre.dll" under mingw when using Configure/Make. I added stuff to
408     Makefile.am that cause it to include this special target, without
409     affecting anything else. Note that the same mingw target plus all
410     the other distribution libraries and programs are now supported
411     when configuring with CMake (see 6 below) instead of with
412     Configure/Make.
413 ph10 309
414 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
415     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
416 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
417     solves the problem, but it does no harm.
418 ph10 313
419 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
420 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
421 ph10 314 with CMake, and also correct the comment about stack recursion.
422 ph10 313
423 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
424 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
425     of a program that users should build themselves after PCRE is installed, so
426     building it automatically is not really right. What is more, it gave
427 ph10 312 trouble in some build environments.
428 ph10 300
429 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
430 ph10 308
431 ph10 319
432 ph10 298 Version 7.5 10-Jan-08
433 ph10 263 ---------------------
434    
435     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
436     values in parens when parsing an RE using the C++ wrapper."
437 ph10 286
438 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
439     Characters greater than 255 were excluded from the class instead of being
440     included.
441 ph10 286
442     3. The same bug as (2) above applied to negated POSIX classes such as
443 ph10 265 [:^space:].
444 ph10 286
445 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
446     defined or documented. It seems to have been a typo for PCRE_STATIC, so
447 ph10 286 I have changed it.
448    
449 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
450 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
451     first named subpattern whose name started with "a" (in other words, the
452 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
453     expected" is now given for (?&) (a zero-length name), and this patch also
454     makes it give the same error for \k'' (previously it complained that that
455     was a reference to a non-existent subpattern).
456 ph10 286
457 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
458 ph10 286 this is right because (?- can be followed by option settings as well as by
459 ph10 269 digits. I have, however, made the messages clearer.
460 ph10 286
461 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
462     than the number used in the conditional) now cause a compile-time error.
463     This is actually not compatible with Perl, which accepts such patterns, but
464     treats the conditional as always being FALSE (as PCRE used to), but it
465     seems to me that giving a diagnostic is better.
466 ph10 286
467 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
468 ph10 275 and messages.
469 ph10 286
470     9. Fix two occurrences of "backslash" in comments that should have been
471     "backspace".
472    
473     10. Remove two redundant lines of code that can never be obeyed (their function
474     was moved elsewhere).
475    
476     11. The program that makes PCRE's Unicode character property table had a bug
477     which caused it to generate incorrect table entries for sequences of
478 ph10 277 characters that have the same character type, but are in different scripts.
479 ph10 286 It amalgamated them into a single range, with the script of the first of
480 ph10 277 them. In other words, some characters were in the wrong script. There were
481     thirteen such cases, affecting characters in the following ranges:
482 ph10 286
483 ph10 277 U+002b0 - U+002c1
484     U+0060c - U+0060d
485 ph10 286 U+0061e - U+00612
486 ph10 277 U+0064b - U+0065e
487     U+0074d - U+0076d
488     U+01800 - U+01805
489     U+01d00 - U+01d77
490     U+01d9b - U+01dbf
491     U+0200b - U+0200f
492     U+030fc - U+030fe
493     U+03260 - U+0327f
494     U+0fb46 - U+0fbb1
495     U+10450 - U+1049d
496 ph10 286
497 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
498     compatible with GNU grep in that, if there was more than one match in a
499     line, it showed only the first of them. It now behaves in the same way as
500     GNU grep.
501 ph10 286
502     13. If the -o and -v options were combined for pcregrep, it printed a blank
503     line for every non-matching line. GNU grep prints nothing, and pcregrep now
504     does the same. The return code can be used to tell if there were any
505     non-matching lines.
506    
507 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
508    
509     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
510 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
511 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
512     and both kinds of lookbehind were skipped).
513    
514 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
515 ph10 284 inclusion of <windows.h> to before rather than after the definition of
516     INVALID_FILE_ATTRIBUTES (patch from David Byron).
517 ph10 263
518 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
519 ph10 286 character property caused pcre_compile() to compile bad code, which led at
520     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
521     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
522     caused the error; without that there was no problem.
523 ph10 263
524 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
525 ph10 286
526 ph10 289 19. Added --enable-pcretest-libreadline.
527 ph10 286
528 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
529 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
530 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
531     later patch that removed the other one (the right fix) and added unit tests
532     that check the return values (which was not done before).
533 ph10 292
534 ph10 291 21. Several CMake things:
535 ph10 287
536 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
537 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
538 ph10 288
539 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
540     linked with the newly-built libraries, not previously installed ones.
541 ph10 291
542 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
543 ph10 298
544     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
545     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
546     UTF-8 newline character). The key issue is that the pattern starts .*;
547     this means that the match must be either at the beginning, or after a
548     newline. The bug was in the code for advancing after a failed match and
549     checking that the new position followed a newline. It was not taking
550 ph10 294 account of UTF-8 characters correctly.
551 ph10 298
552     23. PCRE was behaving differently from Perl in the way it recognized POSIX
553     character classes. PCRE was not treating the sequence [:...:] as a
554     character class unless the ... were all letters. Perl, however, seems to
555     allow any characters between [: and :], though of course it rejects as
556     unknown any "names" that contain non-letters, because all the known class
557     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
558     for example, whereas PCRE did not - it did not recognize a POSIX character
559     class. This seemed a bit dangerous, so the code has been changed to be
560     closer to Perl. The behaviour is not identical to Perl, because PCRE will
561     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
562     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
563     Perl does, and where it didn't before.
564    
565 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
566     Windows environments %n is disabled by default.
567 ph10 292
568    
569 ph10 260 Version 7.4 21-Sep-07
570 ph10 230 ---------------------
571    
572     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
573 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
574     LF". That isn't really right - the whole point of the change was to try to
575     help when there was an actual mention of one of the two characters. So now
576     the change happens only if \r or \n (or a literal CR or LF) character is
577 ph10 230 encountered.
578 ph10 231
579     2. The 32-bit options word was also used for 6 internal flags, but the numbers
580     of both had grown to the point where there were only 3 bits left.
581     Fortunately, there was spare space in the data structure, and so I have
582     moved the internal flags into a new 16-bit field to free up more option
583 ph10 230 bits.
584 ph10 231
585     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
586     but did not set the internal JCHANGED flag - either of these is enough to
587     control the way the "get" function works - but the PCRE_INFO_JCHANGED
588     facility is supposed to tell if (?J) was ever used, so now (?J) at the
589 ph10 230 start sets both bits.
590    
591 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
592     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
593 ph10 230
594 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
595    
596     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
597 ph10 233 compatibility, even though it is no longer used.
598 ph10 243
599     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
600 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
601 ph10 259 windows.h file is present (where different names are used). [This was
602 ph10 257 reversed later after testing - see 16 below.]
603 ph10 243
604     8. Changed all #include <config.h> to #include "config.h". There were also
605 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
606 ph10 243
607 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
608 ph10 243 sequence off the lines that it output.
609    
610     10. It was pointed out to me that arrays of string pointers cause lots of
611     relocations when a shared library is dynamically loaded. A technique of
612     using a single long string with a table of offsets can drastically reduce
613     these. I have refactored PCRE in four places to do this. The result is
614 ph10 240 dramatic:
615 ph10 243
616 ph10 240 Originally: 290
617     After changing UCP table: 187
618 ph10 243 After changing error message table: 43
619 ph10 240 After changing table of "verbs" 36
620     After changing table of Posix names 22
621 ph10 243
622 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
623 ph10 247
624 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
625 ph10 247 unicode-properties was also set.
626    
627 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
628 ph10 231
629 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
630     checked only for CRLF.
631 ph10 233
632 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
633    
634 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
635 ph10 253
636 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
637 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
638     entirely. This removes changes made in 7 above.
639 ph10 256
640 ph10 261 17. The CMake files have been updated, and there is now more information about
641     building with CMake in the NON-UNIX-USE document.
642 ph10 257
643 ph10 261
644 ph10 228 Version 7.3 28-Aug-07
645 ph10 157 ---------------------
646    
647 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
648     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
649     brackets there is not right, since it causes compilers to look for an
650     installed pcre.h, not the version that is in the source that is being
651     compiled (which of course may be different). I have changed it back to:
652 ph10 197
653 ph10 189 #include "pcre.h"
654 ph10 197
655     I have a vague recollection that the change was concerned with compiling in
656     different directories, but in the new build system, that is taken care of
657     by the VPATH setting the Makefile.
658    
659 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
660     when the subject happened to end in the byte 0x85 (e.g. if the last
661     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
662     characters but of course it shouldn't be taken as a newline when it is part
663     of another character. The bug was that, for an unlimited repeat of . in
664     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
665     characters when looking for a newline.
666 ph10 197
667     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
668    
669     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
670     in debug output.
671    
672 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
673     long printing in the pcrecpp unittest when running under MinGW.
674 ph10 189
675 ph10 197 6. ESC_K was left out of the EBCDIC table.
676 ph10 189
677 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
678     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
679     limit also applies to "virtual nesting" when a pattern is recursive, and in
680     this case 1000 isn't so big. I have been able to remove this limit at the
681     expense of backing off one optimization in certain circumstances. Normally,
682     when pcre_exec() would call its internal match() function recursively and
683     immediately return the result unconditionally, it uses a "tail recursion"
684     feature to save stack. However, when a subpattern that can match an empty
685     string has an unlimited repetition quantifier, it no longer makes this
686     optimization. That gives it a stack frame in which to save the data for
687     checking that an empty string has been matched. Previously this was taken
688     from the 1000-entry workspace that had been reserved. So now there is no
689     explicit limit, but more stack is used.
690 ph10 189
691 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
692     syntax that is required for Windows, and which was going wrong for the
693     pcreposix and pcrecpp parts of the library. These were overlooked when this
694     problem was solved for the main library.
695 ph10 197
696 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
697     the size of patterns that contain repeated groups with explicit upper
698     limits. As the maximum quantifier is 65535, the maximum group length was
699     set at 30,000 so that the product of these two numbers did not overflow a
700     32-bit integer. However, it turns out that people want to use groups that
701     are longer than 30,000 bytes (though not repeat them that many times).
702     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
703     made it possible to implement the integer overflow checks in a much more
704     dynamic way, which I have now done. The artificial limitation on group
705     length has been removed - we now have only the limit on the total length of
706     the compiled pattern, which depends on the LINK_SIZE setting.
707 ph10 208
708     10. Fixed a bug in the documentation for get/copy named substring when
709     duplicate names are permitted. If none of the named substrings are set, the
710     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
711     empty string.
712    
713     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
714     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
715     because the ] is interpreted as the first data character and the
716     terminating ] is not found. PCRE has been made compatible with Perl in this
717     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
718     cause memory overwriting.
719    
720 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
721     string has been matched (to stop an infinite loop). It was not recognizing
722 ph10 208 a conditional subpattern that could match an empty string if that
723 ph10 206 subpattern was within another subpattern. For example, it looped when
724 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
725 ph10 206 condition was not nested. This bug has been fixed.
726 ph10 208
727 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
728     past the start of the subject in the presence of bytes with the top bit
729     set, for example "\x8aBCD".
730 ph10 211
731 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
732     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
733 ph10 200
734 ph10 211 14. Optimized (?!) to (*FAIL).
735 ph10 202
736 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
737     This restricts code points to be within the range 0 to 0x10FFFF, excluding
738     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
739     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
740     does: it's just the validity check that is more restrictive.
741 ph10 220
742     16. Inserted checks for integer overflows during escape sequence (backslash)
743     processing, and also fixed erroneous offset values for syntax errors during
744     backslash processing.
745    
746 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
747 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
748    
749 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
750     caused an overrun.
751 ph10 220
752     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
753     something other than just ASCII characters) inside a group that had an
754     unlimited repeat caused a loop at compile time (while checking to see
755     whether the group could match an empty string).
756    
757 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
758     [\P{Any}] did so. (Error in the code for printing property names.)
759 ph10 210
760 ph10 220 21. An orphan \E inside a character class could cause a crash.
761    
762     22. A repeated capturing bracket such as (A)? could cause a wild memory
763 ph10 218 reference during compilation.
764 ph10 220
765     23. There are several functions in pcre_compile() that scan along a compiled
766     expression for various reasons (e.g. to see if it's fixed length for look
767 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
768 ph10 220 present in the pattern. These operators have additional parameters compared
769     with \d, etc, and these were not being taken into account when moving along
770 ph10 218 the compiled data. Specifically:
771 ph10 220
772     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
773     length.
774    
775     (b) An item such as \pL+ within a repeated group could cause crashes or
776 ph10 218 loops.
777 ph10 220
778 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
779 ph10 220 "reference to non-existent subpattern" error.
780    
781 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
782    
783 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
784 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
785 ph10 211
786 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
787 ph10 218
788 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
789 ph10 223 character were causing crashes (broken optimization).
790 ph10 227
791 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
792 ph10 227 \p or \P) caused a compile-time loop.
793    
794 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
795     break. For example, the unstudied pattern [\r\n]A does not match the string
796     "\r\nA" because change 7.0/46 below moves the current point on by two
797     characters after failing to match at the start. However, the pattern \nA
798 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
799     the same is true. There doesn't seem any very clean way out of this, but
800     what I have chosen to do makes the common cases work: PCRE now takes note
801     of whether there can be an explicit match for \r or \n anywhere in the
802     pattern, and if so, 7.0/46 no longer applies. As part of this change,
803     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
804     pattern has explicit CR or LF references.
805 ph10 222
806 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
807 ph10 223
808 ph10 227
809 ph10 189 Version 7.2 19-Jun-07
810     ---------------------
811    
812 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
813     which is apparently normally available under Windows.
814 ph10 159
815     2. Re-jig the pcregrep tests with different newline settings in an attempt
816     to make them independent of the local environment's newline setting.
817 ph10 157
818 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
819 ph10 165
820 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
821     was not 2, because the output contained actual offsets. The recent new
822 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
823     usable with all link sizes.
824    
825 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
826     stack recursion. This gives a massive performance boost under BSD, but just
827 ph10 165 a small improvement under Linux. However, it saves one field in the frame
828 ph10 164 in all cases.
829 ph10 172
830 ph10 166 6. Added more features from the forthcoming Perl 5.10:
831 ph10 172
832 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
833     recursion call. It refers to the nth most recently opened parentheses.
834 ph10 172
835 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
836 ph10 172 to be opened parentheses.
837    
838     (c) Conditions that refer to capturing parentheses can be specified
839 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
840 ph10 172
841 ph10 168 (d) \K resets the start of the current match so that everything before
842 ph10 172 is not part of it.
843    
844 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
845 ph10 172
846 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
847 ph10 172 reference syntax.
848 ph10 182
849 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
850 ph10 182 alternative starts with the same number.
851 ph10 172
852 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
853    
854 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
855     PCRE_INFO_JCHANGED.
856    
857     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
858     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
859 ph10 170 for detecting groups that can match an empty string.
860 ph10 159
861 ph10 172 9. A pattern with a very large number of alternatives (more than several
862     hundred) was running out of internal workspace during the pre-compile
863     phase, where pcre_compile() figures out how much memory will be needed. A
864     bit of new cunning has reduced the workspace needed for groups with
865     alternatives. The 1000-alternative test pattern now uses 12 bytes of
866     workspace instead of running out of the 4096 that are available.
867 ph10 182
868 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
869 ph10 172
870 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
871     The report of the bug said:
872 ph10 182
873 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
874     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
875 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
876 ph10 185
877 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
878 ph10 185 it matched the wrong number of bytes.
879 ph10 172
880 ph10 179
881 ph10 155 Version 7.1 24-Apr-07
882 ph10 98 ---------------------
883    
884 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
885 ph10 122 that is more "standard", making use of automake and other Autotools. There
886 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
887     on this.
888 ph10 111
889     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
890     for recursive directory scanning broke on some systems because the files
891     are not scanned in any specific order and on different systems the order
892     was different. A call to "sort" has been inserted into RunGrepTest for the
893     approprate test as a short-term fix. In the longer term there may be an
894 ph10 100 alternative.
895 ph10 111
896 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
897 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
898     people do their own conversions for various reasons). The problems
899     concerned the use of low-level troff macros .br and .in. I have therefore
900     removed all such uses from the man pages (some were redundant, some could
901 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
902     HTML has been updated to handle .nf/.fi and to complain if it encounters
903     .br or .in.
904 ph10 111
905 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
906 ph10 123 arranged for config.h to be included in the distribution, with the name
907 ph10 111 config.h.generic, for the benefit of those who have to compile without
908     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
909    
910     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
911     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
912 ph10 127 makevp.bat for the current PCRE, using the additional files
913 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
914 ph10 111
915     6. A Windows user reported a minor discrepancy with test 2, which turned out
916     to be caused by a trailing space on an input line that had got lost in his
917 ph10 102 copy. The trailing space was an accident, so I've just removed it.
918 ph10 111
919 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
920 ph10 111 that is needed.
921    
922 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
923     as "const" (a) because they are and (b) because it helps the PHP
924     maintainers who have recently made a script to detect big data structures
925 ph10 111 in the php code that should be moved to the .rodata section. I remembered
926     to update Builducptable as well, so it won't revert if ucptable.h is ever
927 ph10 105 re-created.
928 ph10 111
929     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
930 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
931 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
932     support is not required. This saves 1.5-2K of code, which is important in
933 ph10 107 some applications.
934 ph10 111
935 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
936 ph10 111 so as not to refer to the tables, even though these functions will never be
937     called when UTF-8 support is disabled. Otherwise there are problems with a
938     shared library.
939    
940 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
941    
942     (a) It was defining its arguments as char * instead of void *.
943    
944 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
945     a long time ago when I wrote it, but is no longer the case.
946    
947 ph10 118 The emulated memove() is provided for those environments that have neither
948 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
949 ph10 118 is clearly not the case, as these two bugs were recently reported.
950 ph10 123
951 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
952 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
953     pages, and it removes trailing spaces from listed files. It also creates
954     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
955     case, it wraps all the #defines with #ifndefs. This script should be run
956 ph10 111 before "make dist".
957 ph10 123
958 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
959     with Unicode property support.
960 ph10 123
961     (a) For a maximizing quantifier, if the two different cases of the
962     character were of different lengths in their UTF-8 codings (there are
963     some cases like this - I found 11), and the matching function had to
964 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
965     were both the same length.
966 ph10 123
967     (b) When PCRE was configured to use the heap rather than the stack for
968     recursion during matching, it was not correctly preserving the data for
969     the other case of a UTF-8 character when checking ahead for a match
970     while processing a minimizing repeat. If the check also involved
971 ph10 115 matching a wide character, but failed, corruption could cause an
972     erroneous result when trying to check for a repeat of the original
973     character.
974 ph10 123
975 ph10 116 13. Some tidying changes to the testing mechanism:
976 ph10 98
977 ph10 116 (a) The RunTest script now detects the internal link size and whether there
978     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
979 ph10 123 values substituted by "configure". (The RunGrepTest script already did
980     this for UTF-8.) The configure.ac script no longer substitutes the
981     relevant variables.
982    
983 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
984     with length and offset values. This means that the output is different
985     for different internal link sizes. Test 2 is skipped for link sizes
986     other than 2 because of this, bypassing the problem. Unfortunately,
987     there was also a test in test 3 (the locale tests) that used /B and
988 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
989     I have added a new /Z option to pcretest that replaces the length and
990     offset values with spaces. This is now used to make test 3 independent
991 ph10 122 of link size. (Test 2 will be tidied up later.)
992 ph10 123
993     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
994 ph10 122 segmentation fault instead of returning the appropriate error message.
995 ph10 134
996 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
997 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
998     This doesn't seem right; it now treats the CRLF combination as the line
999     ending, and so does not match in that case. It's only a pattern such as ^$
1000     that would hit this one: something like ^ABC$ would have failed after \r
1001     and then tried again after \r\n.
1002    
1003 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1004 ph10 134 in an attempt to make files that differ only in their line terminators
1005     compare equal. This works on Linux.
1006 ph10 142
1007 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1008     as it exited. This is now fixed, thanks to valgrind.
1009 ph10 142
1010 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1011 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1012     was because its rules for how to advance for /g after matching an empty
1013 ph10 143 string at the end of a line did not allow for this case. They now check for
1014     it specially.
1015 ph10 150
1016     20. pcretest is supposed to handle patterns and data of any length, by
1017     extending its buffers when necessary. It was getting this wrong when the
1018 ph10 147 buffer for a data line had to be extended.
1019 ph10 150
1020 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1021 ph10 150 CRLF as a newline sequence.
1022 ph10 152
1023 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1024 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1025     I have nevertheless tidied it up.
1026 ph10 111
1027 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1028 ph10 123
1029 ph10 153 24. Added a man page for pcre-config.
1030 ph10 152
1031 ph10 153
1032 nigel 93 Version 7.0 19-Dec-06
1033     ---------------------
1034    
1035     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1036     moving to gcc 4.1.1.
1037    
1038     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1039     sys/time.h, which is documented as needed for this function. It doesn't
1040     seem to matter on Linux, but it showed up on some releases of OS X.
1041    
1042     3. It seems that there are systems where bytes whose values are greater than
1043     127 match isprint() in the "C" locale. The "C" locale should be the
1044     default when a C program starts up. In most systems, only ASCII printing
1045     characters match isprint(). This difference caused the output from pcretest
1046     to vary, making some of the tests fail. I have changed pcretest so that:
1047    
1048     (a) When it is outputting text in the compiled version of a pattern, bytes
1049     other than 32-126 are always shown as hex escapes.
1050    
1051     (b) When it is outputting text that is a matched part of a subject string,
1052     it does the same, unless a different locale has been set for the match
1053     (using the /L modifier). In this case, it uses isprint() to decide.
1054    
1055     4. Fixed a major bug that caused incorrect computation of the amount of memory
1056     required for a compiled pattern when options that changed within the
1057     pattern affected the logic of the preliminary scan that determines the
1058     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1059     that the computed length was too small. The symptoms of this bug were
1060     either the PCRE error "internal error: code overflow" from pcre_compile(),
1061     or a glibc crash with a message such as "pcretest: free(): invalid next
1062     size (fast)". Examples of patterns that provoked this bug (shown in
1063     pcretest format) are:
1064    
1065     /(?-x: )/x
1066     /(?x)(?-x: \s*#\s*)/
1067     /((?i)[\x{c0}])/8
1068     /(?i:[\x{c0}])/8
1069    
1070     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1071     is now done differently.
1072    
1073     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1074     wrapper classes; (b) implement a new function in the C++ scanner that is
1075     more efficient than the old way of doing things because it avoids levels of
1076     recursion in the regex matching; (c) add a paragraph to the documentation
1077     for the FullMatch() function.
1078    
1079     6. The escape sequence \n was being treated as whatever was defined as
1080     "newline". Not only was this contrary to the documentation, which states
1081     that \n is character 10 (hex 0A), but it also went horribly wrong when
1082     "newline" was defined as CRLF. This has been fixed.
1083    
1084     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1085     was being set to -1 for the "end of line" case (supposedly a value that no
1086     character can have). Though this value is never used (the check for end of
1087     line is "zero bytes in current character"), it caused compiler complaints.
1088     I've changed it to 0xffffffff.
1089    
1090     8. In pcre_version.c, the version string was being built by a sequence of
1091     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1092     string (as it is for production releases) called a macro with an empty
1093     argument. The C standard says the result of this is undefined. The gcc
1094     compiler treats it as an empty string (which was what was wanted) but it is
1095     reported that Visual C gives an error. The source has been hacked around to
1096     avoid this problem.
1097    
1098     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1099     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1100     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1101     of them did).
1102    
1103     10. Originally, pcretest opened its input and output without "b"; then I was
1104     told that "b" was needed in some environments, so it was added for release
1105     5.0 to both the input and output. (It makes no difference on Unix-like
1106     systems.) Later I was told that it is wrong for the input on Windows. I've
1107     now abstracted the modes into two macros, to make it easier to fiddle with
1108     them, and removed "b" from the input mode under Windows.
1109    
1110     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1111    
1112     12. Added -help and --help to pcretest as an official way of being reminded
1113     of the options.
1114    
1115     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1116     and pcrecpp.cc because they annoy compilers at high warning levels.
1117    
1118     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1119    
1120     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1121     scripts are not C programs :-) and which was not noticed because it works
1122     on Linux.
1123    
1124     16. pcretest is supposed to handle any length of pattern and data line (as one
1125     line or as a continued sequence of lines) by extending its input buffer if
1126     necessary. This feature was broken for very long pattern lines, leading to
1127     a string of junk being passed to pcre_compile() if the pattern was longer
1128     than about 50K.
1129    
1130     17. I have done a major re-factoring of the way pcre_compile() computes the
1131     amount of memory needed for a compiled pattern. Previously, there was code
1132     that made a preliminary scan of the pattern in order to do this. That was
1133     OK when PCRE was new, but as the facilities have expanded, it has become
1134     harder and harder to keep it in step with the real compile phase, and there
1135     have been a number of bugs (see for example, 4 above). I have now found a
1136     cunning way of running the real compile function in a "fake" mode that
1137     enables it to compute how much memory it would need, while actually only
1138     ever using a few hundred bytes of working memory and without too many
1139     tests of the mode. This should make future maintenance and development
1140     easier. A side effect of this work is that the limit of 200 on the nesting
1141     depth of parentheses has been removed (though this was never a serious
1142     limitation, I suspect). However, there is a downside: pcre_compile() now
1143     runs more slowly than before (30% or more, depending on the pattern). I
1144     hope this isn't a big issue. There is no effect on runtime performance.
1145    
1146     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1147     newline (only possible for the last line of a file) and it was a
1148     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1149    
1150     19. Added additional timing features to pcretest. (1) The -tm option now times
1151     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1152     separate command line item, by a number that specifies the number of
1153     repeats to use when timing. The default is 50000; this gives better
1154     precision, but takes uncomfortably long for very large patterns.
1155    
1156     20. Extended pcre_study() to be more clever in cases where a branch of a
1157     subpattern has no definite first character. For example, (a*|b*)[cd] would
1158     previously give no result from pcre_study(). Now it recognizes that the
1159     first character must be a, b, c, or d.
1160    
1161     21. There was an incorrect error "recursive call could loop indefinitely" if
1162     a subpattern (or the entire pattern) that was being tested for matching an
1163     empty string contained only one non-empty item after a nested subpattern.
1164     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1165     incorrectly, because the \d was being skipped in the check.
1166    
1167     22. The pcretest program now has a new pattern option /B and a command line
1168     option -b, which is equivalent to adding /B to every pattern. This causes
1169     it to show the compiled bytecode, without the additional information that
1170     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1171     is the same as /B/I).
1172    
1173     23. A new optimization is now able automatically to treat some sequences such
1174     as a*b as a*+b. More specifically, if something simple (such as a character
1175     or a simple class like \d) has an unlimited quantifier, and is followed by
1176     something that cannot possibly match the quantified thing, the quantifier
1177     is automatically "possessified".
1178    
1179     24. A recursive reference to a subpattern whose number was greater than 39
1180     went wrong under certain circumstances in UTF-8 mode. This bug could also
1181     have affected the operation of pcre_study().
1182    
1183     25. Realized that a little bit of performance could be had by replacing
1184     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1185    
1186     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1187    
1188     27. Possessive quantifiers such as a++ were previously implemented by turning
1189     them into atomic groups such as ($>a+). Now they have their own opcodes,
1190     which improves performance. This includes the automatically created ones
1191     from 23 above.
1192    
1193     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1194     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1195     the first matched character to be a colon. This applied both to named and
1196     numbered groups.
1197    
1198     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1199    
1200     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1201     building PCRE on Windows easier, so I have included it in the distribution.
1202    
1203     31. There is now a check in pcretest against a ridiculously large number being
1204     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1205     loop, the loop is abandoned.
1206    
1207     32. Forward references to subpatterns in conditions such as (?(2)...) where
1208     subpattern 2 is defined later cause pcre_compile() to search forwards in
1209     the pattern for the relevant set of parentheses. This search went wrong
1210     when there were unescaped parentheses in a character class, parentheses
1211     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1212    
1213     33. "Subroutine" calls and backreferences were previously restricted to
1214     referencing subpatterns earlier in the regex. This restriction has now
1215     been removed.
1216    
1217     34. Added a number of extra features that are going to be in Perl 5.10. On the
1218     whole, these are just syntactic alternatives for features that PCRE had
1219     previously implemented using the Python syntax or my own invention. The
1220     other formats are all retained for compatibility.
1221    
1222     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1223     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1224     also .NET compatible.
1225    
1226     (b) A recursion or subroutine call to a named group can now be defined as
1227     (?&name) as well as (?P>name).
1228    
1229     (c) A backreference to a named group can now be defined as \k<name> or
1230     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1231     5.10, are also .NET compatible.
1232    
1233     (d) A conditional reference to a named group can now use the syntax
1234     (?(<name>) or (?('name') as well as (?(name).
1235    
1236     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1237     groups (named and numbered) that are never evaluated inline, but can be
1238     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1239     is always false. There may be only one alternative in such a group.
1240    
1241     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1242     as the simple (?(R). The condition is true only if the most recent
1243     recursion is that of the given number or name. It does not search out
1244     through the entire recursion stack.
1245    
1246     (g) The escape \gN or \g{N} has been added, where N is a positive or
1247     negative number, specifying an absolute or relative reference.
1248    
1249     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1250     some "unreachable code" warnings.
1251    
1252     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1253     things, this adds five new scripts.
1254    
1255     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1256     There were also incompatibilities regarding the handling of \Q..\E inside
1257     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1258     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1259    
1260     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1261     matches an empty string, and forcibly breaks the loop. There were bugs in
1262     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1263     against aaaa the result was just "a" rather than "aaaa", for example. Two
1264     separate and independent bugs (that affected different cases) have been
1265     fixed.
1266    
1267     39. Refactored the code to abolish the use of different opcodes for small
1268     capturing bracket numbers. This is a tidy that I avoided doing when I
1269     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1270     The new approach is not only tidier, it makes it possible to reduce the
1271     memory needed to fix the previous bug (38).
1272    
1273     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1274     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1275     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1276     mode.
1277    
1278     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1279     report.
1280    
1281     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1282     copy construction and assignment in the C++ wrapper.
1283    
1284     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1285     couple of bugs that could have given wrong results in the "--newline=crlf"
1286     case.
1287    
1288     44. Added a number of casts and did some reorganization of signed/unsigned int
1289     variables following suggestions from Dair Grant. Also renamed the variable
1290     "this" as "item" because it is a C++ keyword.
1291    
1292     45. Arranged for dftables to add
1293    
1294     #include "pcre_internal.h"
1295    
1296     to pcre_chartables.c because without it, gcc 4.x may remove the array
1297     definition from the final binary if PCRE is built into a static library and
1298     dead code stripping is activated.
1299    
1300     46. For an unanchored pattern, if a match attempt fails at the start of a
1301     newline sequence, and the newline setting is CRLF or ANY, and the next two
1302     characters are CRLF, advance by two characters instead of one.
1303    
1304    
1305 nigel 91 Version 6.7 04-Jul-06
1306     ---------------------
1307    
1308     1. In order to handle tests when input lines are enormously long, pcretest has
1309     been re-factored so that it automatically extends its buffers when
1310     necessary. The code is crude, but this _is_ just a test program. The
1311     default size has been increased from 32K to 50K.
1312    
1313     2. The code in pcre_study() was using the value of the re argument before
1314     testing it for NULL. (Of course, in any sensible call of the function, it
1315     won't be NULL.)
1316    
1317     3. The memmove() emulation function in pcre_internal.h, which is used on
1318     systems that lack both memmove() and bcopy() - that is, hardly ever -
1319     was missing a "static" storage class specifier.
1320    
1321     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1322     containing an extended class (one that cannot be represented by a bitmap
1323     because it contains high-valued characters or Unicode property items, e.g.
1324     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1325     pattern, but PCRE should not loop if you do not (it no longer does).
1326     [Detail: two cases were found: (a) a repeated subpattern containing an
1327     extended class; (b) a recursive reference to a subpattern that followed a
1328     previous extended class. It wasn't skipping over the extended class
1329     correctly when UTF-8 mode was not set.]
1330    
1331     5. A negated single-character class was not being recognized as fixed-length
1332     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1333     compile error "lookbehind assertion is not fixed length".
1334    
1335     6. The RunPerlTest auxiliary script was showing an unexpected difference
1336     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1337     write a Perl script that can interpret lines of an input file either as
1338     byte characters or as UTF-8, which is what "perltest" was being required to
1339     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1340     can't do is switch easily at run time between having the "use utf8;" pragma
1341     or not. In the end, I fudged it by using the RunPerlTest script to insert
1342     "use utf8;" explicitly for the UTF-8 tests.
1343    
1344     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1345     the end of the subject string, contrary to the documentation and to what
1346     Perl does. This was true of both matching functions. Now it matches only at
1347     the start of the subject and immediately after *internal* newlines.
1348    
1349     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1350     a pointer to an int instead of a pointer to an unsigned long int. This
1351     caused problems on 64-bit systems.
1352    
1353     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1354     instance of the 'standard' template library not being so standard".
1355    
1356     10. There was no check on the number of named subpatterns nor the maximum
1357     length of a subpattern name. The product of these values is used to compute
1358     the size of the memory block for a compiled pattern. By supplying a very
1359     long subpattern name and a large number of named subpatterns, the size
1360     computation could be caused to overflow. This is now prevented by limiting
1361     the length of names to 32 characters, and the number of named subpatterns
1362     to 10,000.
1363    
1364     11. Subpatterns that are repeated with specific counts have to be replicated in
1365     the compiled pattern. The size of memory for this was computed from the
1366     length of the subpattern and the repeat count. The latter is limited to
1367     65535, but there was no limit on the former, meaning that integer overflow
1368     could in principle occur. The compiled length of a repeated subpattern is
1369     now limited to 30,000 bytes in order to prevent this.
1370    
1371     12. Added the optional facility to have named substrings with the same name.
1372    
1373     13. Added the ability to use a named substring as a condition, using the
1374     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1375     are numbers (not recommended). Forward references are permitted.
1376    
1377     14. Added forward references in named backreferences (if you see what I mean).
1378    
1379     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1380     pattern could run off the end of the subject. For example, the pattern
1381     "(?s)(.{1,5})"8 did this with the subject "ab".
1382    
1383     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1384     PCRE_CASELESS was set when matching characters that were quantified with ?
1385     or *.
1386    
1387     17. A character class other than a single negated character that had a minimum
1388     but no maximum quantifier - for example [ab]{6,} - was not handled
1389     correctly by pce_dfa_exec(). It would match only one character.
1390    
1391     18. A valid (though odd) pattern that looked like a POSIX character
1392     class but used an invalid character after [ (for example [[,abc,]]) caused
1393     pcre_compile() to give the error "Failed: internal error: code overflow" or
1394     in some cases to crash with a glibc free() error. This could even happen if
1395     the pattern terminated after [[ but there just happened to be a sequence of
1396     letters, a binary zero, and a closing ] in the memory that followed.
1397    
1398     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1399     over the years. Originally (before any Unicode support), just the bottom 8
1400     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1401     output from "man perlunicode" includes this:
1402    
1403     The regular expression compiler produces polymorphic opcodes. That
1404     is, the pattern adapts to the data and automatically switches to
1405     the Unicode character scheme when presented with Unicode data--or
1406     instead uses a traditional byte scheme when presented with byte
1407     data.
1408    
1409     Sadly, a wide octal escape does not cause a switch, and in a string with
1410     no other multibyte characters, these octal escapes are treated as before.
1411     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1412     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1413     Unicode string.
1414    
1415     I have not perpetrated such confusion in PCRE. Up till now, it took just
1416     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1417     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1418     translate to the appropriate multibyte character.
1419    
1420     29. Applied some refactoring to reduce the number of warnings from Microsoft
1421     and Borland compilers. This has included removing the fudge introduced
1422     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1423     a warning about an unused variable.
1424    
1425     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1426     characters since release 4.0, because Perl (from release 5.004) does not.
1427     [Or at least, is documented not to: some releases seem to be in conflict
1428     with the documentation.] However, when a pattern was studied with
1429     pcre_study() and all its branches started with \s, PCRE still included VT
1430     as a possible starting character. Of course, this did no harm; it just
1431     caused an unnecessary match attempt.
1432    
1433     22. Removed a now-redundant internal flag bit that recorded the fact that case
1434     dependency changed within the pattern. This was once needed for "required
1435     byte" processing, but is no longer used. This recovers a now-scarce options
1436     bit. Also moved the least significant internal flag bit to the most-
1437     significant bit of the word, which was not previously used (hangover from
1438     the days when it was an int rather than a uint) to free up another bit for
1439     the future.
1440    
1441     23. Added support for CRLF line endings as well as CR and LF. As well as the
1442     default being selectable at build time, it can now be changed at runtime
1443     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1444     specify that it is scanning data with non-default line endings.
1445    
1446     24. Changed the definition of CXXLINK to make it agree with the definition of
1447     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1448    
1449     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1450     recursions. This makes a big different to stack usage for some patterns.
1451    
1452     26. If a subpattern containing a named recursion or subroutine reference such
1453     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1454     the space required for the compiled pattern went wrong and gave too small a
1455     value. Depending on the environment, this could lead to "Failed: internal
1456     error: code overflow at offset 49" or "glibc detected double free or
1457     corruption" errors.
1458    
1459     27. Applied patches from Google (a) to support the new newline modes and (b) to
1460     advance over multibyte UTF-8 characters in GlobalReplace.
1461    
1462     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1463     difference for some implementation of PCRE in some Windows version.
1464    
1465     29. Added some extra testing facilities to pcretest:
1466    
1467     \q<number> in a data line sets the "match limit" value
1468     \Q<number> in a data line sets the "match recursion limt" value
1469     -S <number> sets the stack size, where <number> is in megabytes
1470    
1471     The -S option isn't available for Windows.
1472    
1473    
1474 nigel 89 Version 6.6 06-Feb-06
1475     ---------------------
1476    
1477     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1478     in pcreposix.h. I have copied the definition from pcre.h.
1479    
1480     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1481     because pcre.h is no longer a built file.
1482    
1483     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1484     not normally included in the compiled code.
1485    
1486    
1487 nigel 87 Version 6.5 01-Feb-06
1488     ---------------------
1489    
1490     1. When using the partial match feature with pcre_dfa_exec(), it was not
1491     anchoring the second and subsequent partial matches at the new starting
1492     point. This could lead to incorrect results. For example, with the pattern
1493     /1234/, partially matching against "123" and then "a4" gave a match.
1494    
1495     2. Changes to pcregrep:
1496    
1497     (a) All non-match returns from pcre_exec() were being treated as failures
1498     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1499     error message is output. Some extra information is given for the
1500     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1501     probably the only errors that are likely to be caused by users (by
1502     specifying a regex that has nested indefinite repeats, for instance).
1503     If there are more than 20 of these errors, pcregrep is abandoned.
1504    
1505     (b) A binary zero was treated as data while matching, but terminated the
1506     output line if it was written out. This has been fixed: binary zeroes
1507     are now no different to any other data bytes.
1508    
1509     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1510     used to set a locale for matching. The --locale=xxxx long option has
1511     been added (no short equivalent) to specify a locale explicitly on the
1512     pcregrep command, overriding the environment variables.
1513    
1514     (d) When -B was used with -n, some line numbers in the output were one less
1515     than they should have been.
1516    
1517     (e) Added the -o (--only-matching) option.
1518    
1519     (f) If -A or -C was used with -c (count only), some lines of context were
1520     accidentally printed for the final match.
1521    
1522     (g) Added the -H (--with-filename) option.
1523    
1524     (h) The combination of options -rh failed to suppress file names for files
1525     that were found from directory arguments.
1526    
1527     (i) Added the -D (--devices) and -d (--directories) options.
1528    
1529     (j) Added the -F (--fixed-strings) option.
1530    
1531     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1532    
1533     (l) Added the --colo(u)r option.
1534    
1535     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1536     is not present by default.
1537    
1538     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1539     items such as (?R) or (?1), when the recursion could match a number of
1540     alternatives. If it matched one of the alternatives, but subsequently,
1541     outside the recursion, there was a failure, the code tried to back up into
1542     the recursion. However, because of the way PCRE is implemented, this is not
1543     possible, and the result was an incorrect result from the match.
1544    
1545     In order to prevent this happening, the specification of recursion has
1546     been changed so that all such subpatterns are automatically treated as
1547     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1548    
1549     4. I had overlooked the fact that, in some locales, there are characters for
1550     which isalpha() is true but neither isupper() nor islower() are true. In
1551     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1552     and ordfeminine) are like this. This affected the treatment of \w and \W
1553     when they appeared in character classes, but not when they appeared outside
1554     a character class. The bit map for "word" characters is now created
1555     separately from the results of isalnum() instead of just taking it from the
1556     upper, lower, and digit maps. (Plus the underscore character, of course.)
1557    
1558     5. The above bug also affected the handling of POSIX character classes such as
1559     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1560     permanent tables. Instead, the bit maps for such a class were previously
1561     created as the appropriate unions of the upper, lower, and digit bitmaps.
1562     Now they are created by subtraction from the [[:word:]] class, which has
1563     its own bitmap.
1564    
1565     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1566     It is created by subtracting the vertical space characters (\x09, \x0a,
1567     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1568     subtraction was done in the overall bitmap for a character class, meaning
1569     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1570     be recognized. This bug has been fixed.
1571    
1572     7. Patches from the folks at Google:
1573    
1574     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1575     real life, but is still worth protecting against".
1576    
1577     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1578     regular expressions".
1579    
1580     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1581     have it.
1582    
1583     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1584     "configure" and the latter not, in order to fix a problem somebody had
1585     with compiling the Arg class on HP-UX.
1586    
1587     (e) Improve the error-handling of the C++ wrapper a little bit.
1588    
1589     (f) New tests for checking recursion limiting.
1590    
1591     8. The pcre_memmove() function, which is used only if the environment does not
1592     have a standard memmove() function (and is therefore rarely compiled),
1593     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1594     returning a result (though PCRE never actually uses the result).
1595    
1596     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1597     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1598     returned instead of calling malloc() with an overflowing number that would
1599     most likely cause subsequent chaos.
1600    
1601     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1602    
1603     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1604     with this option is matched, the nmatch and pmatch options of regexec() are
1605     ignored.
1606    
1607     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1608     provided in case anyone wants to the the POSIX interface with UTF-8
1609     strings.
1610    
1611     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1612     C++ linking (needed for some HP-UX environments).
1613    
1614     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1615     (unused parameter) and in the pcre_printint() function (omitted "default"
1616     switch label when the default is to do nothing).
1617    
1618     15. Added some code to make it possible, when PCRE is compiled as a C++
1619     library, to replace subject pointers for pcre_exec() with a smart pointer
1620     class, thus making it possible to process discontinuous strings.
1621    
1622     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1623     much the same function. They were added by different people who were trying
1624     to make PCRE easy to compile on non-Unix systems. It has been suggested
1625     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1626     for compiling on Windows systems. I have therefore replaced it with
1627     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1628     defaults to "extern" for C or "extern C" for C++, which works fine on
1629     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1630     SCOPE with something explicit in config.h. In addition:
1631    
1632     (a) pcreposix.h still had just "extern" instead of either of these macros;
1633     I have replaced it with PCRE_DATA_SCOPE.
1634    
1635     (b) Functions such as _pcre_xclass(), which are internal to the library,
1636     but external in the C sense, all had PCRE_EXPORT in their definitions.
1637     This is apparently wrong for the Windows case, so I have removed it.
1638     (It makes no difference on Unix-like systems.)
1639    
1640     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1641     of recursive calls to match(). This is different to MATCH_LIMIT because
1642     that limits the total number of calls to match(), not all of which increase
1643     the depth of recursion. Limiting the recursion depth limits the amount of
1644     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1645     when PCRE is compiled, and changed at run time. A patch from Google adds
1646     this functionality to the C++ interface.
1647    
1648     18. Changes to the handling of Unicode character properties:
1649    
1650     (a) Updated the table to Unicode 4.1.0.
1651    
1652     (b) Recognize characters that are not in the table as "Cn" (undefined).
1653    
1654     (c) I revised the way the table is implemented to a much improved format
1655     which includes recognition of ranges. It now supports the ranges that
1656     are defined in UnicodeData.txt, and it also amalgamates other
1657     characters into ranges. This has reduced the number of entries in the
1658     table from around 16,000 to around 3,000, thus reducing its size
1659     considerably. I realized I did not need to use a tree structure after
1660     all - a binary chop search is just as efficient. Having reduced the
1661     number of entries, I extended their size from 6 bytes to 8 bytes to
1662     allow for more data.
1663    
1664     (d) Added support for Unicode script names via properties such as \p{Han}.
1665    
1666     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1667     matching that character.
1668    
1669     20. When matching a repeated Unicode property with a minimum greater than zero,
1670     (for example \pL{2,}), PCRE could look past the end of the subject if it
1671     reached it while seeking the minimum number of characters. This could
1672     happen only if some of the characters were more than one byte long, because
1673     there is a check for at least the minimum number of bytes.
1674    
1675     21. Refactored the implementation of \p and \P so as to be more general, to
1676     allow for more different types of property in future. This has changed the
1677     compiled form incompatibly. Anybody with saved compiled patterns that use
1678     \p or \P will have to recompile them.
1679    
1680     22. Added "Any" and "L&" to the supported property types.
1681    
1682     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1683     but give a compile time error if the value is greater than 0xff.
1684    
1685     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1686     accidentally not being installed or uninstalled.
1687    
1688     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1689     made were to insert the current release number. This seemed silly, because
1690     it made things harder for people building PCRE on systems that don't run
1691     "configure". I have turned pcre.h into a distributed file, no longer built
1692     by "configure", with the version identification directly included. There is
1693     no longer a pcre.h.in file.
1694    
1695     However, this change necessitated a change to the pcre-config script as
1696     well. It is built from pcre-config.in, and one of the substitutions was the
1697     release number. I have updated configure.ac so that ./configure now finds
1698     the release number by grepping pcre.h.
1699    
1700     26. Added the ability to run the tests under valgrind.
1701    
1702    
1703 nigel 85 Version 6.4 05-Sep-05
1704     ---------------------
1705    
1706     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1707     "--" to be printed when multiple files were scanned, even when none of the
1708     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1709     consider it to be a bug, and have restored the previous behaviour.
1710    
1711     2. A couple of code tidies to get rid of compiler warnings.
1712    
1713     3. The pcretest program used to cheat by referring to symbols in the library
1714     whose names begin with _pcre_. These are internal symbols that are not
1715     really supposed to be visible externally, and in some environments it is
1716     possible to suppress them. The cheating is now confined to including
1717     certain files from the library's source, which is a bit cleaner.
1718    
1719     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1720     file's purpose clearer.
1721    
1722     5. Reorganized pcre_ucp_findchar().
1723    
1724    
1725 nigel 83 Version 6.3 15-Aug-05
1726     ---------------------
1727    
1728     1. The file libpcre.pc.in did not have general read permission in the tarball.
1729    
1730     2. There were some problems when building without C++ support:
1731    
1732     (a) If C++ support was not built, "make install" and "make test" still
1733     tried to test it.
1734    
1735     (b) There were problems when the value of CXX was explicitly set. Some
1736     changes have been made to try to fix these, and ...
1737    
1738     (c) --disable-cpp can now be used to explicitly disable C++ support.
1739    
1740     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1741     backslash in a target when C++ was disabled. This confuses some
1742     versions of "make", apparently. Using an intermediate variable solves
1743     this. (Same for CPP_LOBJ.)
1744    
1745     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1746     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1747     necessary on certain architectures.
1748    
1749     4. Added a setting of -export-symbols-regex to the link command to remove
1750     those symbols that are exported in the C sense, but actually are local
1751     within the library, and not documented. Their names all begin with
1752     "_pcre_". This is not a perfect job, because (a) we have to except some
1753     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1754     available (and never for static libraries). I have made a note to try to
1755     find a way round (a) in the future.
1756    
1757    
1758 nigel 81 Version 6.2 01-Aug-05
1759     ---------------------
1760    
1761     1. There was no test for integer overflow of quantifier values. A construction
1762     such as {1111111111111111} would give undefined results. What is worse, if
1763     a minimum quantifier for a parenthesized subpattern overflowed and became
1764     negative, the calculation of the memory size went wrong. This could have
1765     led to memory overwriting.
1766    
1767     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1768    
1769     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1770     operating environments where this matters.
1771    
1772     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1773     PCRE options from within the C++ wrapper.
1774    
1775     5. Named capturing subpatterns were not being correctly counted when a pattern
1776     was compiled. This caused two problems: (a) If there were more than 100
1777     such subpatterns, the calculation of the memory needed for the whole
1778     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1779     back references of the form \12, where the number was greater than 9, were
1780     not recognized as back references, even though there were sufficient
1781     previous subpatterns.
1782    
1783     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1784     versions of gcc, e.g. 2.95.4.
1785    
1786    
1787 nigel 79 Version 6.1 21-Jun-05
1788     ---------------------
1789    
1790     1. There was one reference to the variable "posix" in pcretest.c that was not
1791     surrounded by "#if !defined NOPOSIX".
1792    
1793     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1794     the cross-check on the old pcre_info() function, for the benefit of the
1795     cut-down version of PCRE that is currently imported into Exim.
1796    
1797     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1798     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1799     patterns that start (?i) but I don't think that matters. The use of (?i) is
1800     just an example; this all applies to the other options as well.
1801    
1802     4. Since libtool seems to echo the compile commands it is issuing, the output
1803     from "make" can be reduced a bit by putting "@" in front of each libtool
1804     compile command.
1805    
1806     5. Patch from the folks at Google for configure.in to be a bit more thorough
1807     in checking for a suitable C++ installation before trying to compile the
1808     C++ stuff. This should fix a reported problem when a compiler was present,
1809     but no suitable headers.
1810    
1811     6. The man pages all had just "PCRE" as their title. I have changed them to
1812     be the relevant file name. I have also arranged that these names are
1813     retained in the file doc/pcre.txt, which is a concatenation in text format
1814     of all the man pages except the little individual ones for each function.
1815    
1816     7. The NON-UNIX-USE file had not been updated for the different set of source
1817     files that come with release 6. I also added a few comments about the C++
1818     wrapper.
1819    
1820    
1821 nigel 77 Version 6.0 07-Jun-05
1822     ---------------------
1823    
1824     1. Some minor internal re-organization to help with my DFA experiments.
1825    
1826     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1827     didn't matter for the library itself when fully configured, but did matter
1828     when compiling without UCP support, or within Exim, where the ucp files are
1829     not imported.
1830    
1831     3. Refactoring of the library code to split up the various functions into
1832     different source modules. The addition of the new DFA matching code (see
1833     below) to a single monolithic source would have made it really too
1834     unwieldy, quite apart from causing all the code to be include in a
1835     statically linked application, when only some functions are used. This is
1836     relevant even without the DFA addition now that patterns can be compiled in
1837     one application and matched in another.
1838    
1839     The downside of splitting up is that there have to be some external
1840     functions and data tables that are used internally in different modules of
1841     the library but which are not part of the API. These have all had their
1842     names changed to start with "_pcre_" so that they are unlikely to clash
1843     with other external names.
1844    
1845     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1846     a different (DFA) algorithm. Although it is slower than the original
1847     function, it does have some advantages for certain types of matching
1848     problem.
1849    
1850     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1851     including restarting after a partial match.
1852    
1853     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1854     defined when compiling for Windows was sent to me. I have put it into the
1855     code, though I have no means of testing or verifying it.
1856    
1857     7. Added the pcre_refcount() auxiliary function.
1858    
1859     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1860     match before or at the first newline in the subject string. In pcretest,
1861     the /f option on a pattern can be used to set this.
1862    
1863     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1864     would behave wrongly. This has been present in PCRE since release 4.0.
1865    
1866     10. A number of changes to the pcregrep command:
1867    
1868     (a) Refactored how -x works; insert ^(...)$ instead of setting
1869     PCRE_ANCHORED and checking the length, in preparation for adding
1870     something similar for -w.
1871    
1872     (b) Added the -w (match as a word) option.
1873    
1874     (c) Refactored the way lines are read and buffered so as to have more
1875     than one at a time available.
1876    
1877     (d) Implemented a pcregrep test script.
1878    
1879     (e) Added the -M (multiline match) option. This allows patterns to match
1880     over several lines of the subject. The buffering ensures that at least
1881     8K, or the rest of the document (whichever is the shorter) is available
1882     for matching (and similarly the previous 8K for lookbehind assertions).
1883    
1884     (f) Changed the --help output so that it now says
1885    
1886     -w, --word-regex(p)
1887    
1888     instead of two lines, one with "regex" and the other with "regexp"
1889     because that confused at least one person since the short forms are the
1890     same. (This required a bit of code, as the output is generated
1891     automatically from a table. It wasn't just a text change.)
1892    
1893     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1894     option but starts with a hyphen. Could be a pattern or a path name
1895     starting with a hyphen, for instance.
1896    
1897     (h) "-" can be given as a file name to represent stdin.
1898    
1899     (i) When file names are being printed, "(standard input)" is used for
1900     the standard input, for compatibility with GNU grep. Previously
1901     "<stdin>" was used.
1902    
1903     (j) The option --label=xxx can be used to supply a name to be used for
1904     stdin when file names are being printed. There is no short form.
1905    
1906     (k) Re-factored the options decoding logic because we are going to add
1907     two more options that take data. Such options can now be given in four
1908     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1909    
1910     (l) Added the -A, -B, and -C options for requesting that lines of context
1911     around matches be printed.
1912    
1913     (m) Added the -L option to print the names of files that do not contain
1914     any matching lines, that is, the complement of -l.
1915    
1916     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1917     continue to scan other files.
1918    
1919     (o) The -s option was incorrectly implemented. For compatibility with other
1920     greps, it now suppresses the error message for a non-existent or non-
1921     accessible file (but not the return code). There is a new option called
1922     -q that suppresses the output of matching lines, which was what -s was
1923     previously doing.
1924    
1925     (p) Added --include and --exclude options to specify files for inclusion
1926     and exclusion when recursing.
1927    
1928     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1929     Hopefully, it now does.
1930    
1931     12. Missing cast in pcre_study().
1932    
1933     13. Added an "uninstall" target to the makefile.
1934    
1935     14. Replaced "extern" in the function prototypes in Makefile.in with
1936     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1937     world, but is set differently for Windows.
1938    
1939     15. Added a second compiling function called pcre_compile2(). The only
1940     difference is that it has an extra argument, which is a pointer to an
1941     integer error code. When there is a compile-time failure, this is set
1942     non-zero, in addition to the error test pointer being set to point to an
1943     error message. The new argument may be NULL if no error number is required
1944     (but then you may as well call pcre_compile(), which is now just a
1945     wrapper). This facility is provided because some applications need a
1946     numeric error indication, but it has also enabled me to tidy up the way
1947     compile-time errors are handled in the POSIX wrapper.
1948    
1949     16. Added VPATH=.libs to the makefile; this should help when building with one
1950     prefix path and installing with another. (Or so I'm told by someone who
1951     knows more about this stuff than I do.)
1952    
1953     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1954     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1955     match everything, including newlines. This is not POSIX-compatible, but
1956     somebody wanted the feature. From pcretest it can be activated by using
1957     both the P and the s flags.
1958    
1959     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1960    
1961     19. libpcre.pc was being incorrectly installed as executable.
1962    
1963     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1964     it now also looks for '\r' so that it will work unmodified on Windows.
1965    
1966     21. Added Google's contributed C++ wrapper to the distribution.
1967    
1968     22. Added some untidy missing memory free() calls in pcretest, to keep
1969     Electric Fence happy when testing.
1970    
1971    
1972    
1973 nigel 75 Version 5.0 13-Sep-04
1974     ---------------------
1975    
1976     1. Internal change: literal characters are no longer packed up into items
1977     containing multiple characters in a single byte-string. Each character
1978     is now matched using a separate opcode. However, there may be more than one
1979     byte in the character in UTF-8 mode.
1980    
1981     2. The pcre_callout_block structure has two new fields: pattern_position and
1982     next_item_length. These contain the offset in the pattern to the next match
1983     item, and its length, respectively.
1984    
1985     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1986     insertion of callouts before each pattern item. Added the /C option to
1987     pcretest to make use of this.
1988    
1989     4. On the advice of a Windows user, the lines
1990    
1991     #if defined(_WIN32) || defined(WIN32)
1992     _setmode( _fileno( stdout ), 0x8000 );
1993     #endif /* defined(_WIN32) || defined(WIN32) */
1994    
1995     have been added to the source of pcretest. This apparently does useful
1996     magic in relation to line terminators.
1997    
1998     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1999     for the benefit of those environments where the "b" makes a difference.
2000    
2001     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2002     to know about it. I have put a hack into configure.in that adds in code
2003     to set GCC=yes if CC=icc. This seems to end up at a point in the
2004     generated configure script that is early enough to affect the setting of
2005     compiler options, which is what is needed, but I have no means of testing
2006     whether it really works. (The user who reported this had patched the
2007     generated configure script, which of course I cannot do.)
2008    
2009     LATER: After change 22 below (new libtool files), the configure script
2010     seems to know about icc (and also ecc). Therefore, I have commented out
2011     this hack in configure.in.
2012    
2013     7. Added support for pkg-config (2 patches were sent in).
2014    
2015     8. Negated POSIX character classes that used a combination of internal tables
2016     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2017     [[:^ascii]]. Typically, they would match almost any characters. The other
2018     POSIX classes were not broken in this way.
2019    
2020     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2021     to find the match, as PCRE was deluded into thinking that the match had to
2022     start at the start point or following a newline. The same bug applied to
2023     patterns with negative forward assertions or any backward assertions
2024     preceding ".*" at the start, unless the pattern required a fixed first
2025     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2026    
2027     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2028     starting at the last subject character, bytes beyond the end of the subject
2029     string were read.
2030    
2031     11. Renamed the variable "class" as "classbits" to make life easier for C++
2032     users. (Previously there was a macro definition, but it apparently wasn't
2033     enough.)
2034    
2035     12. Added the new field "tables" to the extra data so that tables can be passed
2036     in at exec time, or the internal tables can be re-selected. This allows
2037     a compiled regex to be saved and re-used at a later time by a different
2038     program that might have everything at different addresses.
2039    
2040     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2041     -R library as well as a -L library.
2042    
2043     14. The debugging options of pcretest (-d on the command line or D on a
2044     pattern) showed incorrect output for anything following an extended class
2045     that contained multibyte characters and which was followed by a quantifier.
2046    
2047     15. Added optional support for general category Unicode character properties
2048     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2049     support. It adds about 90K to the size of the library. The meanings of the
2050     inbuilt class escapes such as \d and \s have NOT been changed.
2051    
2052     16. Updated pcredemo.c to include calls to free() to release the memory for the
2053     compiled pattern.
2054    
2055     17. The generated file chartables.c was being created in the source directory
2056     instead of in the building directory. This caused the build to fail if the
2057     source directory was different from the building directory, and was
2058     read-only.
2059    
2060     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2061     file. No doubt somebody will tell me if they don't make sense... Also added
2062     Dan Mooney's comments about building on OpenVMS.
2063    
2064     19. Added support for partial matching via the PCRE_PARTIAL option for
2065     pcre_exec() and the \P data escape in pcretest.
2066    
2067     20. Extended pcretest with 3 new pattern features:
2068    
2069     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2070     write the compiled pattern to the file whose name is "rest-of-line".
2071     This is a straight binary dump of the data, with the saved pointer to
2072     the character tables forced to be NULL. The study data, if any, is
2073     written too. After writing, pcretest reads a new pattern.
2074    
2075     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2076     compiled pattern from the given file. There must not be any
2077     occurrences of "<" in the file name (pretty unlikely); if there are,
2078     pcretest will instead treat the initial "<" as a pattern delimiter.
2079     After reading in the pattern, pcretest goes on to read data lines as
2080     usual.
2081    
2082     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2083     and 16-bit fields in a compiled pattern, to simulate a pattern that
2084     was compiled on a host of opposite endianness.
2085    
2086     21. The pcre-exec() function can now cope with patterns that were compiled on
2087     hosts of opposite endianness, with this restriction:
2088    
2089     As for any compiled expression that is saved and used later, the tables
2090     pointer field cannot be preserved; the extra_data field in the arguments
2091     to pcre_exec() should be used to pass in a tables address if a value
2092     other than the default internal tables were used at compile time.
2093    
2094     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2095     now diagnosed as an error. Previously, most of the time, a negative number
2096     would have been treated as zero, but if in addition "ovector" was passed as
2097     NULL, a crash could occur.
2098    
2099     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2100     new versions from the libtool 1.5 distribution (the last one is a copy of
2101     a file called libtool.m4). This seems to have fixed the need to patch
2102     "configure" to support Darwin 1.3 (which I used to do). However, I still
2103     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2104     workstation).
2105    
2106     24. Changed the PCRE licence to be the more standard "BSD" licence.
2107    
2108    
2109 nigel 73 Version 4.5 01-Dec-03
2110     ---------------------
2111    
2112     1. There has been some re-arrangement of the code for the match() function so
2113     that it can be compiled in a version that does not call itself recursively.
2114     Instead, it keeps those local variables that need separate instances for
2115     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2116     needs to "recurse". Keeping track of where control must go is done by means
2117     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2118     hide most of the details from the main code, and operates only if
2119     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2120     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2121     operating.
2122    
2123     To make it easier for callers to provide specially tailored get/free
2124     functions for this usage, two new functions, pcre_stack_malloc, and
2125     pcre_stack_free, are used. They are always called in strict stacking order,
2126     and the size of block requested is always the same.
2127    
2128     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2129     PCRE has been compiled to use the stack or the heap for recursion. The
2130     -C option of pcretest uses this to show which version is compiled.
2131    
2132     A new data escape \S, is added to pcretest; it causes the amounts of store
2133     obtained and freed by both kinds of malloc/free at match time to be added
2134     to the output.
2135    
2136     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2137     what's available on my current Linux desktop machine.
2138    
2139     3. When matching a UTF-8 string, the test for a valid string at the start has
2140     been extended. If start_offset is not zero, PCRE now checks that it points
2141     to a byte that is the start of a UTF-8 character. If not, it returns
2142     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2143     this is necessary because there may be backward assertions in the pattern.
2144     When matching the same subject several times, it may save resources to use
2145     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2146    
2147     4. The code for checking the validity of UTF-8 strings has been tightened so
2148     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2149     containing "overlong sequences".
2150    
2151     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2152     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2153     should have been "&", but it just so happened that all the cases this let
2154     through by mistake were picked up later in the function.
2155    
2156     6. I had used a variable called "isblank" - this is a C99 function, causing
2157     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2158    
2159     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2160     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2161     so the version is shown; (c) stop "make test" echoing "./RunTest".
2162    
2163     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2164    
2165     9. The prototype for memmove() for systems that don't have it was using
2166     size_t, but the inclusion of the header that defines size_t was later. I've
2167     moved the #includes for the C headers earlier to avoid this.
2168    
2169     10. Added some adjustments to the code to make it easier to compiler on certain
2170     special systems:
2171    
2172     (a) Some "const" qualifiers were missing.
2173     (b) Added the macro EXPORT before all exported functions; by default this
2174     is defined to be empty.
2175     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2176     that it reads its output file name as an argument instead of writing
2177     to the standard output and assuming this can be redirected.
2178    
2179     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2180     class containing characters with values greater than 255, PCRE compilation
2181     went into a loop.
2182    
2183     12. A recursive reference to a subpattern that was within another subpattern
2184     that had a minimum quantifier of zero caused PCRE to crash. For example,
2185     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2186     recursion. If the recursively-called subpattern itself had a zero repeat,
2187     that was OK.
2188    
2189     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2190     buffer into which it was copied (for escape processing) was still set at
2191     1024, so long lines caused crashes.
2192    
2193     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2194     "internal error: code overflow...". This applied to any character class
2195     that was followed by a possessive quantifier.
2196    
2197     15. Modified the Makefile to add libpcre.la as a prerequisite for
2198     libpcreposix.la because I was told this is needed for a parallel build to
2199     work.
2200    
2201     16. If a pattern that contained .* following optional items at the start was
2202     studied, the wrong optimizing data was generated, leading to matching
2203     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2204     matching string must start with a or b or c. The correct conclusion for
2205     this pattern is that a match can start with any character.
2206    
2207    
2208 nigel 71 Version 4.4 13-Aug-03
2209     ---------------------
2210    
2211     1. In UTF-8 mode, a character class containing characters with values between
2212     127 and 255 was not handled correctly if the compiled pattern was studied.
2213     In fixing this, I have also improved the studying algorithm for such
2214     classes (slightly).
2215    
2216     2. Three internal functions had redundant arguments passed to them. Removal
2217     might give a very teeny performance improvement.
2218    
2219     3. Documentation bug: the value of the capture_top field in a callout is *one
2220     more than* the number of the hightest numbered captured substring.
2221    
2222     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2223     in incorrectly linking with a previously installed version. They now link
2224     explicitly with libpcre.la.
2225    
2226     5. configure.in no longer needs to recognize Cygwin specially.
2227    
2228     6. A problem in pcre.in for Windows platforms is fixed.
2229    
2230     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2231     pcretest, it used to include the size of the study block as part of its
2232     output. Unfortunately, the structure contains a field that has a different
2233     size on different hardware architectures. This meant that the tests that
2234     showed this size failed. As the block is currently always of a fixed size,
2235     this information isn't actually particularly useful in pcretest output, so
2236     I have just removed it.
2237    
2238     8. Three pre-processor statements accidentally did not start in column 1.
2239     Sadly, there are *still* compilers around that complain, even though
2240     standard C has not required this for well over a decade. Sigh.
2241    
2242     9. In pcretest, the code for checking callouts passed small integers in the
2243     callout_data field, which is a void * field. However, some picky compilers
2244     complained about the casts involved for this on 64-bit systems. Now
2245     pcretest passes the address of the small integer instead, which should get
2246     rid of the warnings.
2247    
2248     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2249     both compile and run time, and gives an error if an invalid UTF-8 sequence
2250     is found. There is a option for disabling this check in cases where the
2251     string is known to be correct and/or the maximum performance is wanted.
2252    
2253     11. In response to a bug report, I changed one line in Makefile.in from
2254    
2255     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2256     to
2257     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2258    
2259     to look similar to other lines, but I have no way of telling whether this
2260     is the right thing to do, as I do not use Windows. No doubt I'll get told
2261     if it's wrong...
2262    
2263    
2264 nigel 69 Version 4.3 21-May-03
2265     ---------------------
2266    
2267     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2268     Makefile.
2269    
2270     2. Some refactoring to improve the quality of the code:
2271    
2272     (i) The utf8_table... variables are now declared "const".
2273    
2274     (ii) The code for \cx, which used the "case flipping" table to upper case
2275     lower case letters, now just substracts 32. This is ASCII-specific,
2276     but the whole concept of \cx is ASCII-specific, so it seems
2277     reasonable.
2278    
2279     (iii) PCRE was using its character types table to recognize decimal and
2280     hexadecimal digits in the pattern. This is silly, because it handles
2281     only 0-9, a-f, and A-F, but the character types table is locale-
2282     specific, which means strange things might happen. A private
2283     table is now used for this - though it costs 256 bytes, a table is
2284     much faster than multiple explicit tests. Of course, the standard
2285     character types table is still used for matching digits in subject
2286     strings against \d.
2287    
2288     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2289     ending in _t are). So I've renamed it as ESC_tee.
2290    
2291     3. The first argument for regexec() in the POSIX wrapper should have been
2292     defined as "const".
2293    
2294     4. Changed pcretest to use malloc() for its buffers so that they can be
2295     Electric Fenced for debugging.
2296    
2297     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2298     to read one or more bytes before the start of the subject string. Often this
2299     had no effect on PCRE's behaviour, but in some circumstances it could
2300     provoke a segmentation fault.
2301    
2302     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2303     to try to read one or more bytes before the start of the subject string.
2304    
2305     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2306     UTF-8 support could misbehave in various ways if the subject string
2307     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2308     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2309     back over UTF-8 characters.)
2310    
2311    
2312 nigel 67 Version 4.2 14-Apr-03
2313     ---------------------
2314    
2315     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2316    
2317     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2318     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2319     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2320     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2321     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2322     and BUILD_EXEEXT
2323     Note: automatic setting of the BUILD variables is not yet working
2324     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2325     compile-time but not at link-time
2326     [LINK]: use for linking executables only
2327     make different versions for Windows and non-Windows
2328     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2329     libraries
2330     [LINK_FOR_BUILD]: new variable
2331     [OBJEXT]: use throughout
2332     [EXEEXT]: use throughout
2333     <winshared>: new target
2334     <wininstall>: new target
2335     <dftables.o>: use native compiler
2336     <dftables>: use native linker
2337     <install>: handle Windows platform correctly
2338     <clean>: ditto
2339     <check>: ditto
2340     copy DLL to top builddir before testing
2341    
2342     As part of these changes, -no-undefined was removed again. This was reported
2343     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2344     in any case.
2345    
2346     3. Some tidies to get rid of compiler warnings:
2347    
2348     . In the match_data structure, match_limit was an unsigned long int, whereas
2349     match_call_count was an int. I've made them both unsigned long ints.
2350    
2351     . In pcretest the fact that a const uschar * doesn't automatically cast to
2352     a void * provoked a warning.
2353    
2354     . Turning on some more compiler warnings threw up some "shadow" variables
2355     and a few more missing casts.
2356    
2357     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2358     option, a class that contained a single character with a value between 128
2359     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2360    
2361     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2362     option, a class that contained several characters, but with at least one
2363     whose value was between 128 and 255 caused PCRE to crash.
2364    
2365    
2366 nigel 65 Version 4.1 12-Mar-03
2367     ---------------------
2368 nigel 63
2369 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2370     needed, and a string in dftables.c that was longer than standard compilers are
2371     required to support.
2372    
2373     2. Compiling with Sun's compiler found a few more places where the code could
2374     be tidied up in order to avoid warnings.
2375    
2376     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2377     first of these names is deprecated in the latest Autoconf in favour of the name
2378     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2379     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2380     analogy I have changed it to CFLAGS_FOR_BUILD.
2381    
2382     4. Added -no-undefined to the linking command in the Makefile, because this is
2383     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2384     linking step for the pcreposix library.
2385    
2386     5. PCRE was failing to diagnose the case of two named groups with the same
2387     name.
2388    
2389     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2390     literal character that is needed in the subject for a match, and scans along to
2391     ensure that it is present before embarking on the full matching process. This
2392     saves time in cases of nested unlimited repeats that are never going to match.
2393     Problem: the scan can take a lot of time if the subject is very long (e.g.
2394     megabytes), thus penalizing straightforward matches. It is now done only if the
2395     amount of subject to be scanned is less than 1000 bytes.
2396    
2397     7. A lesser problem with the same optimization is that it was recording the
2398     first character of an anchored pattern as "needed", thus provoking a search
2399     right along the subject, even when the first match of the pattern was going to
2400     fail. The "needed" character is now not set for anchored patterns, unless it
2401     follows something in the pattern that is of non-fixed length. Thus, it still
2402     fulfils its original purpose of finding quick non-matches in cases of nested
2403     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2404    
2405    
2406     Version 4.0 17-Feb-03
2407     ---------------------
2408    
2409 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2410     extended to the end of string, PCRE compiled incorrect data. This could lead to
2411     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2412    
2413     2. Moved to autoconf 2.53 and libtool 1.4.2.
2414    
2415     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2416     the special perltest8 script is no longer needed - all the tests can be run
2417     from a single perltest script.
2418    
2419     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2420     by \s. It has now been removed in PCRE. This means it isn't recognized as
2421     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2422     class [:space:] *does* include VT, thereby creating a mess.
2423    
2424     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2425     space and tab.
2426    
2427     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2428     its new features into the main test script, reducing the number of scripts.
2429    
2430     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2431     were backward compatible, and made the (?i) apply to the whole pattern, as if
2432     /i were given. Now it behaves more logically, and applies the option setting
2433     only to what follows. PCRE has been changed to follow suit. However, if it
2434     finds options settings right at the start of the pattern, it extracts them into
2435     the global options, as before. Thus, they show up in the info data.
2436    
2437     8. Added support for the \Q...\E escape sequence. Characters in between are
2438     treated as literals. This is slightly different from Perl in that $ and @ are
2439     also handled as literals inside the quotes. In Perl, they will cause variable
2440     interpolation. Note the following examples:
2441    
2442     Pattern PCRE matches Perl matches
2443    
2444     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2445     \Qabc\$xyz\E abc\$xyz abc\$xyz
2446     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2447    
2448     For compatibility with Perl, \Q...\E sequences are recognized inside character
2449     classes as well as outside them.
2450    
2451     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2452     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2453     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2454     signed/unsigned warnings.
2455    
2456     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2457     option for pcretest, so I've replaced it by a simple function that does just
2458     that job.
2459    
2460     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2461     "pcregrep -".
2462    
2463     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2464     Java package. This provides some syntactic sugar for simple cases of what my
2465     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2466     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2467     item, you can use this simplified notation. Note that only makes sense with
2468     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2469     greediness, whatever the setting of the PCRE_UNGREEDY option.
2470    
2471     13. A change of greediness default within a pattern was not taking effect at
2472     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2473     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2474     was abstracted outside.
2475    
2476     14. PCRE now supports the \G assertion. It is true when the current matching
2477     position is at the start point of the match. This differs from \A when the
2478     starting offset is non-zero. Used with the /g option of pcretest (or similar
2479     code), it works in the same way as it does for Perl's /g option. If all
2480     alternatives of a regex begin with \G, the expression is anchored to the start
2481     match position, and the "anchored" flag is set in the compiled expression.
2482    
2483     15. Some bugs concerning the handling of certain option changes within patterns
2484     have been fixed. These applied to options other than (?ims). For example,
2485     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2486     been the other way round. Some of this was related to change 7 above.
2487    
2488     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2489     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2490     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2491     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2492    
2493     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2494     mode. Unlike ".", it always matches newline, whatever the setting of
2495     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2496     assertions. Perl allows it, but it doesn't (in general) work because it can't
2497     calculate the length of the lookbehind. At least, that's the case for Perl
2498     5.8.0 - I've been told they are going to document that it doesn't work in
2499     future.
2500    
2501     18. Added an error diagnosis for escapes that PCRE does not support: these are
2502     \L, \l, \N, \P, \p, \U, \u, and \X.
2503    
2504     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2505     reading past the end of the pattern in cases such as /[abcd/.
2506    
2507     20. PCRE was getting more memory than necessary for patterns with classes that
2508     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2509    
2510     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2511     compiling PCRE for use with Virtual Pascal.
2512    
2513     22. Small fix to the Makefile to make it work properly if the build is done
2514     outside the source tree.
2515    
2516     23. Added a new extension: a condition to go with recursion. If a conditional
2517     subpattern starts with (?(R) the "true" branch is used if recursion has
2518     happened, whereas the "false" branch is used only at the top level.
2519    
2520     24. When there was a very long string of literal characters (over 255 bytes
2521     without UTF support, over 250 bytes with UTF support), the computation of how
2522     much memory was required could be incorrect, leading to segfaults or other
2523     strange effects.
2524    
2525     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2526     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2527     there was a subsequent back reference to those brackets. This meant that, for
2528     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2529     possible to check for precisely this case. All we can do is abandon the
2530     optimization if .* occurs inside capturing brackets when there are any back
2531     references whatsoever. (See below for a better fix that came later.)
2532    
2533     26. The handling of the optimization for finding the first character of a
2534     non-anchored pattern, and for finding a character that is required later in the
2535     match were failing in some cases. This didn't break the matching; it just
2536     failed to optimize when it could. The way this is done has been re-implemented.
2537    
2538     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2539    
2540     28. Added a new feature that provides some of the functionality that Perl
2541     provides with (?{...}). The facility is termed a "callout". The way it is done
2542     in PCRE is for the caller to provide an optional function, by setting
2543     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2544     global variable. By default it is unset, which disables all calling out. To get
2545     the function called, the regex must include (?C) at appropriate points. This
2546     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2547     This provides a means of identifying different callout points. When PCRE
2548     reaches such a point in the regex, if pcre_callout has been set, the external
2549     function is called. It is provided with data in a structure called
2550     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2551     matching continues; if it returns a non-zero value, the match at the current
2552     point fails. However, backtracking will occur if possible. [This was changed
2553     later and other features added - see item 49 below.]
2554    
2555     29. pcretest is upgraded to test the callout functionality. It provides a
2556     callout function that displays information. By default, it shows the start of
2557     the match and the current position in the text. There are some new data escapes
2558     to vary what happens:
2559    
2560     \C+ in addition, show current contents of captured substrings
2561     \C- do not supply a callout function
2562     \C!n return 1 when callout number n is reached
2563     \C!n!m return 1 when callout number n is reached for the mth time
2564    
2565     30. If pcregrep was called with the -l option and just a single file name, it
2566     output "<stdin>" if a match was found, instead of the file name.
2567    
2568     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2569     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2570     pcre_exec(). This saves a malloc/free per call. The default value of
2571     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2572     when configuring.
2573    
2574     32. The default maximum size of a compiled pattern is 64K. There have been a
2575     few cases of people hitting this limit. The code now uses macros to handle the
2576     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2577     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2578     configuring. Tests 2 and 5 work only with 2-byte links because they output
2579     debugging information about compiled patterns.
2580    
2581     33. Internal code re-arrangements:
2582    
2583     (a) Moved the debugging function for printing out a compiled regex into
2584     its own source file (printint.c) and used #include to pull it into
2585     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2586     separate copies.
2587    
2588     (b) Defined the list of op-code names for debugging as a macro in
2589     internal.h so that it is next to the definition of the opcodes.
2590    
2591     (c) Defined a table of op-code lengths for simpler skipping along compiled
2592     code. This is again a macro in internal.h so that it is next to the
2593     definition of the opcodes.
2594    
2595     34. Added support for recursive calls to individual subpatterns, along the
2596     lines of Robin Houston's patch (but implemented somewhat differently).
2597    
2598     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2599     allow it to read and process whole directories in Win32. This code was
2600     contributed by Lionel Fourquaux; it has not been tested by me.
2601    
2602     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2603     used to name a group. Names consist of alphanumerics and underscores, and must
2604     be unique. Back references use the syntax (?P=name) and recursive calls use
2605     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2606     numbers. The function pcre_fullinfo() can be used after compilation to extract
2607     a name/number map. There are three relevant calls:
2608    
2609     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2610     PCRE_INFO_NAMECOUNT yields the number of entries
2611     PCRE_INFO_NAMETABLE yields a pointer to the map.
2612    
2613     The map is a vector of fixed-size entries. The size of each entry depends on
2614     the length of the longest name used. The first two bytes of each entry are the
2615     group number, most significant byte first. There follows the corresponding
2616     name, zero terminated. The names are in alphabetical order.
2617    
2618     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2619     case instead of 255. Making it the same both with and without UTF-8 support
2620     means that the same test output works with both.
2621    
2622     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2623     calling malloc() with a zero argument.
2624    
2625     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2626     optimization. I've improved things by keeping a bitmap of backreferences with
2627     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2628     fact referenced, the optimization can be applied. It is unlikely that a
2629     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2630     the match to follow \n) will appear inside brackets with a number greater than
2631     31, but if it does, any back reference > 31 suppresses the optimization.
2632    
2633     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2634     of disabling numbered capturing parentheses. Any opening parenthesis that is
2635     not followed by ? behaves as if it were followed by ?: but named parentheses
2636     can still be used for capturing (and they will acquire numbers in the usual
2637     way).
2638    
2639     41. Redesigned the return codes from the match() function into yes/no/error so
2640     that errors can be passed back from deep inside the nested calls. A malloc
2641     failure while inside a recursive subpattern call now causes the
2642     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2643    
2644     42. It is now possible to set a limit on the number of times the match()
2645     function is called in a call to pcre_exec(). This facility makes it possible to
2646     limit the amount of recursion and backtracking, though not in a directly
2647     obvious way, because the match() function is used in a number of different
2648     circumstances. The count starts from zero for each position in the subject
2649     string (for non-anchored patterns). The default limit is, for compatibility, a
2650     large number, namely 10 000 000. You can change this in two ways:
2651    
2652     (a) When configuring PCRE before making, you can use --with-match-limit=n
2653     to set a default value for the compiled library.
2654    
2655     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2656     a different value is set. See 45 below.
2657    
2658     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2659    
2660     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2661     of things that can be changed at compile time. The first argument specifies
2662     what is wanted and the second points to where the information is to be placed.
2663     The current list of available information is:
2664    
2665     PCRE_CONFIG_UTF8
2666    
2667     The output is an integer that is set to one if UTF-8 support is available;
2668     otherwise it is set to zero.
2669    
2670     PCRE_CONFIG_NEWLINE
2671    
2672     The output is an integer that it set to the value of the code that is used for
2673     newline. It is either LF (10) or CR (13).
2674    
2675     PCRE_CONFIG_LINK_SIZE
2676    
2677     The output is an integer that contains the number of bytes used for internal
2678     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2679    
2680     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2681    
2682     The output is an integer that contains the threshold above which the POSIX
2683     interface uses malloc() for output vectors. See item 31 above.
2684    
2685     PCRE_CONFIG_MATCH_LIMIT
2686    
2687     The output is an unsigned integer that contains the default limit of the number
2688     of match() calls in a pcre_exec() execution. See 42 above.
2689    
2690     44. pcretest has been upgraded by the addition of the -C option. This causes it
2691     to extract all the available output from the new pcre_config() function, and to
2692     output it. The program then exits immediately.
2693    
2694     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2695     order to support additional features. One way would have been to define
2696     pcre_exec2() (for example) with extra arguments, but this would not have been
2697     extensible, and would also have required all calls to the original function to
2698     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2699     is used for passing in "extra" data from pcre_study().
2700    
2701     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2702     contains the following fields:
2703    
2704     flags a bitmap indicating which of the following fields are set
2705     study_data opaque data from pcre_study()
2706     match_limit a way of specifying a limit on match() calls for a specific
2707     call to pcre_exec()
2708     callout_data data for callouts (see 49 below)
2709    
2710     The flag bits are also defined in pcre.h, and are
2711    
2712     PCRE_EXTRA_STUDY_DATA
2713     PCRE_EXTRA_MATCH_LIMIT
2714     PCRE_EXTRA_CALLOUT_DATA
2715    
2716     The pcre_study() function now returns one of these new pcre_extra blocks, with
2717     the actual study data pointed to by the study_data field, and the
2718     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2719     before. That is, this change is entirely upwards-compatible and requires no
2720     change to existing code.
2721    
2722     If you want to pass in additional data to pcre_exec(), you can either place it
2723     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2724     block.
2725    
2726     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2727     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2728     times with different match limits, until it finds the minimum value needed for
2729     pcre_exec() to complete. The value is then output. This can be instructive; for
2730     most simple matches the number is quite small, but for pathological cases it
2731     gets very large very quickly.
2732    
2733     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2734     returns the size of the data block pointed to by the study_data field in a
2735     pcre_extra block, that is, the value that was passed as the argument to
2736     pcre_malloc() when PCRE was getting memory in which to place the information
2737     created by pcre_study(). The fourth argument should point to a size_t variable.
2738     pcretest has been extended so that this information is shown after a successful
2739     pcre_study() call when information about the compiled regex is being displayed.
2740    
2741     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2742     because what follows is always an absolute path. (Later: it turns out that this
2743     is more than cosmetic for MinGW, because it doesn't like empty path
2744     components.)
2745    
2746     49. Some changes have been made to the callout feature (see 28 above):
2747    
2748     (i) A callout function now has three choices for what it returns:
2749    
2750     0 => success, carry on matching
2751     > 0 => failure at this point, but backtrack if possible
2752     < 0 => serious error, return this value from pcre_exec()
2753    
2754     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2755     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2756     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2757     use by callout functions. It will never be used by PCRE itself.
2758    
2759     (ii) The pcre_extra structure (see 45 above) has a void * field called
2760     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2761     pcre_callout_block structure has a field of the same name. The contents of
2762     the field passed in the pcre_extra structure are passed to the callout
2763     function in the corresponding field in the callout block. This makes it
2764     easier to use the same callout-containing regex from multiple threads. For
2765     testing, the pcretest program has a new data escape
2766    
2767     \C*n pass the number n (may be negative) as callout_data
2768    
2769     If the callout function in pcretest receives a non-zero value as
2770     callout_data, it returns that value.
2771    
2772     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2773     there were some redundant $(CFLAGS) in commands that are now specified as
2774     $(LINK), which already includes $(CFLAGS).
2775    
2776     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2777     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2778     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2779     one-byte characters throughout. Note that case-insensitive matching applies
2780     only to characters whose values are less than 256. PCRE doesn't support the
2781     notion of cases for higher-valued characters.
2782    
2783     (i) A character class whose characters are all within 0-255 is handled as
2784     a bit map, and the map is inverted for negative classes. Previously, a
2785     character > 255 always failed to match such a class; however it should
2786     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2787    
2788     (ii) A negated character class with a single character < 255 is coded as
2789     "not this character" (OP_NOT). This wasn't working properly when the test
2790     character was multibyte, either singly or repeated.
2791    
2792     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2793     mode, for example: \x{100}{2,3}.
2794    
2795     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2796     singly or repeated) now correctly test multibyte characters. However,
2797     PCRE doesn't recognize any characters with values greater than 255 as
2798     digits, spaces, or word characters. Such characters always match \D, \S,
2799     and \W, and never match \d, \s, or \w.
2800    
2801     (v) Classes may now contain characters and character ranges with values
2802     greater than 255. For example: [ab\x{100}-\x{400}].
2803    
2804     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2805     PCRE in UTF-8 mode.
2806    
2807     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2808     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2809     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2810     value.)
2811    
2812     53. The single man page has become too large. I have therefore split it up into
2813     a number of separate man pages. These also give rise to individual HTML pages;
2814     these are now put in a separate directory, and there is an index.html page that
2815     lists them all. Some hyperlinking between the pages has been installed.
2816    
2817     54. Added convenience functions for handling named capturing parentheses.
2818    
2819     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2820     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2821     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2822     are faulted.
2823    
2824     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2825     calling configure. These values are used when compiling the dftables.c program
2826     which is run to generate the source of the default character tables. They
2827     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2828     you will need to set these values.
2829    
2830     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2831    
2832    
2833     Version 3.9 02-Jan-02
2834 nigel 61 ---------------------
2835    
2836     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2837    
2838     2. If --disable-static was given, the building process failed when trying to
2839     build pcretest and pcregrep. (For some reason it was using libtool to compile
2840     them, which is not right, as they aren't part of the library.)
2841    
2842    
2843 nigel 59 Version 3.8 18-Dec-01
2844     ---------------------
2845    
2846     1. The experimental UTF-8 code was completely screwed up. It was packing the
2847     bytes in the wrong order. How dumb can you get?
2848    
2849    
2850 nigel 57 Version 3.7 29-Oct-01
2851     ---------------------
2852    
2853     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2854     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2855     this didn't happen under Solaris 8, where I normally test things.
2856    
2857 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2858     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2859     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2860     this fix an hour or so after the initial 3.7 release.)
2861 nigel 57
2862 nigel 59
2863 nigel 55 Version 3.6 23-Oct-01
2864     ---------------------
2865    
2866     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2867     offsets passed as NULL with zero offset count.
2868    
2869     2. The config.guess and config.sub files had not been updated when I moved to
2870     the latest autoconf.
2871    
2872    
2873 nigel 53 Version 3.5 15-Aug-01
2874     ---------------------
2875 nigel 5
2876 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2877     had been forgotten.
2878    
2879     2. By using declared but undefined structures, we can avoid using "void"
2880     definitions in pcre.h while keeping the internal definitions of the structures
2881     private.
2882    
2883     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2884     user point of view, this means that both static and shared libraries are built
2885     by default, but this can be individually controlled. More of the work of
2886     handling this static/shared cases is now inside libtool instead of PCRE's make
2887     file.
2888    
2889     4. The pcretest utility is now installed along with pcregrep because it is
2890     useful for users (to test regexs) and by doing this, it automatically gets
2891     relinked by libtool. The documentation has been turned into a man page, so
2892     there are now .1, .txt, and .html versions in /doc.
2893    
2894     5. Upgrades to pcregrep:
2895     (i) Added long-form option names like gnu grep.
2896     (ii) Added --help to list all options with an explanatory phrase.
2897     (iii) Added -r, --recursive to recurse into sub-directories.
2898     (iv) Added -f, --file to read patterns from a file.
2899    
2900     6. pcre_exec() was referring to its "code" argument before testing that
2901     argument for NULL (and giving an error if it was NULL).
2902    
2903     7. Upgraded Makefile.in to allow for compiling in a different directory from
2904     the source directory.
2905    
2906     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2907     options bits, the pointer it was passed was to an int instead of to an unsigned
2908     long int. This mattered only on 64-bit systems.
2909    
2910     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2911     generated) instead of pcre.in, which it its source. Also made the same change
2912     in several of the .c files.
2913    
2914     10. A new release of gcc defines printf() as a macro, which broke pcretest
2915     because it had an ifdef in the middle of a string argument for printf(). Fixed
2916     by using separate calls to printf().
2917    
2918     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2919     script, to force use of CR or LF instead of \n in the source. On non-Unix
2920     systems, the value can be set in config.h.
2921    
2922     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2923     absolute limit. Changed the text of the error message to make this clear, and
2924     likewise updated the man page.
2925    
2926     13. The limit of 99 on the number of capturing subpatterns has been removed.
2927     The new limit is 65535, which I hope will not be a "real" limit.
2928    
2929    
2930 nigel 51 Version 3.4 22-Aug-00
2931     ---------------------
2932    
2933     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2934    
2935     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2936    
2937    
2938 nigel 49 Version 3.3 01-Aug-00
2939     ---------------------
2940    
2941     1. If an octal character was given, but the value was greater than \377, it
2942     was not getting masked to the least significant bits, as documented. This could
2943     lead to crashes in some systems.
2944    
2945     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2946     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2947    
2948     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2949     These just pass their arguments on to (pcre_free)(), but they are provided
2950     because some uses of PCRE bind it to non-C systems that can call its functions,
2951     but cannot call free() or pcre_free() directly.
2952    
2953     4. Add "make test" as a synonym for "make check". Corrected some comments in
2954     the Makefile.
2955    
2956     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2957     Makefile.
2958    
2959     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2960     command called pgrep for grepping around the active processes.
2961    
2962     7. Added the beginnings of support for UTF-8 character strings.
2963    
2964     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2965     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2966     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2967     out for the ar command.)
2968    
2969    
2970 nigel 47 Version 3.2 12-May-00
2971     ---------------------
2972    
2973     This is purely a bug fixing release.
2974    
2975     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2976     of ZA. This was just one example of several cases that could provoke this bug,
2977     which was introduced by change 9 of version 2.00. The code for breaking
2978     infinite loops after an iteration that matches an empty string was't working
2979     correctly.
2980    
2981     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2982     when matched against abbab (for example). After matching an empty string, it
2983     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2984     caused it to match further down the string than it should.
2985    
2986     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2987     was there because it doesn't seem to be needed, and it causes trouble on some
2988     systems, as it is not a Standard C header. It has been removed.
2989    
2990     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2991     were reported on the Macintosh. The changes were from
2992    
2993     while ((c = *(++ptr)) != 0 && c != '\n');
2994     to
2995     while ((c = *(++ptr)) != 0 && c != '\n') ;
2996    
2997     Totally extraordinary, but if that's what it takes...
2998    
2999     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3000     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3001     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3002     assumes the way PCRE uses memmove() (always moving upwards).
3003    
3004     6. PCRE is being used in one environment where strchr() is not available. There
3005     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3006     faster code anyway.
3007    
3008    
3009 nigel 45 Version 3.1 09-Feb-00
3010     ---------------------
3011    
3012     The only change in this release is the fixing of some bugs in Makefile.in for
3013     the "install" target:
3014    
3015     (1) It was failing to install pcreposix.h.
3016    
3017     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3018    
3019    
3020 nigel 43 Version 3.0 01-Feb-00
3021     ---------------------
3022 nigel 41
3023     1. Add support for the /+ modifier to perltest (to output $` like it does in
3024     pcretest).
3025    
3026     2. Add support for the /g modifier to perltest.
3027    
3028     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3029     matches null strings.
3030    
3031     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3032     pattern. Perl treats empty patterns specially - it reuses the most recent
3033     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3034     effect.
3035    
3036     5. The POSIX interface was broken in that it was just handing over the POSIX
3037     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3038     required a bigger vector, with some working space on the end. This means that
3039     the POSIX wrapper now has to get and free some memory, and copy the results.
3040    
3041 nigel 43 6. Added some simple autoconf support, placing the test data and the
3042     documentation in separate directories, re-organizing some of the
3043     information files, and making it build pcre-config (a GNU standard). Also added
3044     libtool support for building PCRE as a shared library, which is now the
3045     default.
3046 nigel 41
3047 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3048     09 are not valid octal constants. Single digits will be used for minor values
3049     less than 10.
3050    
3051     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3052     existing programs that set these in the POSIX interface can use PCRE without
3053     modification.
3054    
3055     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3056     return all that pcre_info() returns, plus additional data. The pcre_info()
3057     function is retained for compatibility, but is considered to be obsolete.
3058    
3059     10. Added experimental recursion feature (?R) to handle one common case that
3060     Perl 5.6 will be able to do with (?p{...}).
3061    
3062     11. Added support for POSIX character classes like [:alpha:], which Perl is
3063     adopting.
3064    
3065    
3066 nigel 39 Version 2.08 31-Aug-99
3067     ----------------------
3068    
3069     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3070     trying to match at the startoffset position, but instead was moving forward to
3071     the next newline as if a previous match had failed.
3072    
3073     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3074     and could get into a loop if a null string was matched other than at the start
3075     of the subject.
3076    
3077     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3078     be distinguished at compile time, and for completeness also added PCRE_DATE.
3079    
3080     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3081     in GnuWin32 environments.
3082    
3083    
3084 nigel 37 Version 2.07 29-Jul-99
3085     ----------------------
3086    
3087     1. The documentation is now supplied in plain text form and HTML as well as in
3088     the form of man page sources.
3089    
3090     2. C++ compilers don't like assigning (void *) values to other pointer types.
3091     In particular this affects malloc(). Although there is no problem in Standard
3092     C, I've put in casts to keep C++ compilers happy.
3093    
3094     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3095     should be (const char *).
3096    
3097     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3098     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3099     However, I haven't made this a standard facility. The documentation doesn't
3100     mention it, and the Makefile doesn't support it.
3101    
3102     5. The Makefile now contains an "install" target, with editable destinations at
3103     the top of the file. The pcretest program is not installed.
3104    
3105     6. pgrep -V now gives the PCRE version number and date.
3106    
3107     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3108     causing the entire string to be ignored, instead of just the last character.
3109    
3110     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3111     non-matching string, it can take a very, very long time, even for strings of
3112     quite modest length, because of the nested recursion. PCRE now does better in
3113     some of these cases. It does this by remembering the last required literal
3114     character in the pattern, and pre-searching the subject to ensure it is present
3115     before running the real match. In other words, it applies a heuristic to detect
3116     some types of certain failure quickly, and in the above example, if presented
3117     with a string that has no trailing " it gives "no match" very quickly.
3118    
3119     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3120     other alternatives are tried instead.
3121    
3122    
3123 nigel 35 Version 2.06 09-Jun-99
3124     ----------------------
3125    
3126     1. Change pcretest's output for amount of store used to show just the code
3127     space, because the remainder (the data block) varies in size between 32-bit and
3128     64-bit systems.
3129    
3130     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3131     start matching at. This allows lookbehinds to work when searching for multiple
3132     occurrences in a string.
3133    
3134     3. Added additional options to pcretest for testing multiple occurrences:
3135    
3136     /+ outputs the rest of the string that follows a match
3137     /g loops for multiple occurrences, using the new startoffset argument
3138     /G loops for multiple occurrences by passing an incremented pointer
3139    
3140     4. PCRE wasn't doing the "first character" optimization for patterns starting
3141     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3142     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3143     the letter 'x'. On long subject strings, this gives a significant speed-up.
3144    
3145    
3146 nigel 33 Version 2.05 21-Apr-99
3147     ----------------------
3148    
3149     1. Changed the type of magic_number from int to long int so that it works
3150     properly on 16-bit systems.
3151    
3152     2. Fixed a bug which caused patterns starting with .* not to work correctly
3153     when the subject string contained newline characters. PCRE was assuming
3154     anchoring for such patterns in all cases, which is not correct because .* will
3155     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3156     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3157     must be retried after every newline in the subject.
3158    
3159    
3160 nigel 31 Version 2.04 18-Feb-99
3161     ----------------------
3162    
3163     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3164     computation of the store needed to hold the pattern was incorrect (too large).
3165     If such patterns were nested a few deep, this could multiply and become a real
3166     problem.
3167    
3168     2. Added /M option to pcretest to show the memory requirement of a specific
3169     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3170    
3171     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3172     compiled in such a way that the backtracking after subsequent failure was
3173     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3174     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3175    
3176    
3177 nigel 29 Version 2.03 02-Feb-99
3178     ----------------------
3179    
3180     1. Fixed typo and small mistake in man page.
3181    
3182 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3183     LICENCE file containing the conditions.
3184 nigel 29
3185     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3186     Perl, that is the internal \ allows the delimiter to be included in the
3187     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3188     the final delimiter, add \ to the end of the pattern (to test the error).
3189    
3190     4. Added the convenience functions for extracting substrings after a successful
3191     match. Updated pcretest to make it able to test these functions.
3192    
3193    
3194 nigel 27 Version 2.02 14-Jan-99
3195     ----------------------
3196    
3197     1. Initialized the working variables associated with each extraction so that
3198     their saving and restoring doesn't refer to uninitialized store.
3199    
3200     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3201     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3202     fix the problem.
3203    
3204     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3205     calls, and wasn't printing the correct value for compiling calls. Increased the
3206     default value of LOOPREPEAT, and the number of significant figures in the
3207     times.
3208    
3209     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3210    
3211     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3212     a building problem on Windows NT with a FAT file system.
3213    
3214    
3215 nigel 25 Version 2.01 21-Oct-98
3216     ----------------------
3217    
3218     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3219     to character tables built by pcre_maketables() in the current locale. If NULL
3220     is passed, the default tables are used.
3221    
3222    
3223 nigel 23 Version 2.00 24-Sep-98
3224 nigel 21 ----------------------
3225    
3226 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3227     it any more.
3228    
3229     2. Allow quantification of (?>) groups, and make it work correctly.
3230    
3231     3. The first character computation wasn't working for (?>) groups.
3232    
3233     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3234     end of the subject) and add 5.005's \z, which really does match only at the
3235     very end of the subject.
3236    
3237     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3238    
3239     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3240     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3241     localized options. All options to pcre_study() were also removed.
3242    
3243     7. Add other new features from 5.005:
3244    
3245     $(?<= positive lookbehind
3246     $(?<! negative lookbehind
3247     (?imsx-imsx) added the unsetting capability
3248     such a setting is global if at outer level; local otherwise
3249     (?imsx-imsx:) non-capturing groups with option setting
3250     (?(cond)re|re) conditional pattern matching
3251    
3252     A backreference to itself in a repeated group matches the previous
3253     captured string.
3254    
3255     8. General tidying up of studying (both automatic and via "study")
3256     consequential on the addition of new assertions.
3257    
3258     9. As in 5.005, unlimited repeated groups that could match an empty substring
3259     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3260     runtime if any iteration does actually match an empty substring.
3261    
3262     10. Include the RunTest script in the distribution.
3263    
3264     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3265     discrepancies, some of which were old and were also with respect to 5.004. They
3266     have now been fixed.
3267    
3268    
3269     Version 1.09 28-Apr-98
3270     ----------------------
3271    
3272 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3273     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3274     program crashes, or just wrong answers. This did not apply to negated classes
3275     containing more than one character, or to minima other than one.
3276    
3277    
3278 nigel 19 Version 1.08 27-Mar-98
3279     ----------------------
3280    
3281     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3282    
3283     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3284     latter must appear before anything that relies on it in the pattern.
3285    
3286    
3287 nigel 17 Version 1.07 16-Feb-98
3288     ----------------------
3289    
3290     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3291     repeat of a potentially empty string).
3292    
3293    
3294 nigel 15 Version 1.06 23-Jan-98
3295     ----------------------
3296    
3297     1. Added Markus Oberhumer's little patches for C++.
3298    
3299     2. Literal strings longer than 255 characters were broken.
3300    
3301    
3302 nigel 13 Version 1.05 23-Dec-97
3303     ----------------------
3304    
3305     1. Negated character classes containing more than one character were failing if
3306     PCRE_CASELESS was set at run time.
3307    
3308    
3309 nigel 11 Version 1.04 19-Dec-97
3310     ----------------------
3311    
3312     1. Corrected the man page, where some "const" qualifiers had been omitted.
3313    
3314     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3315     input syntax.
3316    
3317     3. Fixed memory leak which occurred when a regex with back references was
3318     matched with an offsets vector that wasn't big enough. The temporary memory
3319     that is used in this case wasn't being freed if the match failed.
3320    
3321     4. Tidied pcretest to ensure it frees memory that it gets.
3322    
3323     5. Temporary memory was being obtained in the case where the passed offsets
3324     vector was exactly big enough.
3325    
3326     6. Corrected definition of offsetof() from change 5 below.
3327    
3328     7. I had screwed up change 6 below and broken the rules for the use of
3329     setjmp(). Now fixed.
3330    
3331    
3332 nigel 9 Version 1.03 18-Dec-97
3333     ----------------------
3334    
3335     1. A erroneous regex with a missing opening parenthesis was correctly
3336     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3337     on some systems.
3338    
3339     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3340     it was reported that one broken compiler failed on the former because "code" is
3341     also an independent variable.
3342    
3343     3. The erroneous regex a[]b caused an array overrun reference.
3344    
3345     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3346     fail on data ending with that character. (It was going on too far, and checking
3347     the next character, typically a binary zero.) This was specific to the
3348     optimized code for single-character negative classes.
3349    
3350     5. Added a contributed patch from the TIN world which does the following:
3351    
3352     + Add an undef for memmove, in case the the system defines a macro for it.
3353    
3354     + Add a definition of offsetof(), in case there isn't one. (I don't know
3355     the reason behind this - offsetof() is part of the ANSI standard - but
3356     it does no harm).
3357    
3358     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3359     most of the places where whitespace preceded '#'. I have given up and
3360     allowed the remaining 2 cases to be at the margin.
3361    
3362     + Rename some variables in pcre to eliminate shadowing. This seems very
3363     pedantic, but does no harm, of course.
3364    
3365     6. Moved the call to setjmp() into its own function, to get rid of warnings
3366     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3367    
3368     7. Constructs such as \d{8,} were compiling into the equivalent of
3369 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3370 nigel 9 outcome, but in this particular case used more store than had been allocated,
3371     which caused the bug to be discovered because it threw up an internal error.
3372    
3373     8. The debugging code in both pcre and pcretest for outputting the compiled
3374     form of a regex was going wrong in the case of back references followed by
3375     curly-bracketed repeats.
3376    
3377    
3378 nigel 7 Version 1.02 12-Dec-97
3379     ----------------------
3380    
3381     1. Typos in pcre.3 and comments in the source fixed.
3382    
3383     2. Applied a contributed patch to get rid of places where it used to remove
3384     'const' from variables, and fixed some signed/unsigned and uninitialized
3385     variable warnings.
3386    
3387     3. Added the "runtest" target to Makefile.
3388    
3389     4. Set default compiler flag to -O2 rather than just -O.
3390    
3391    
3392 nigel 5 Version 1.01 19-Nov-97
3393     ----------------------
3394    
3395     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3396     like /([ab]*)*/, that is, for classes with more than one character in them.
3397    
3398     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3399     as /((?>a*))*/ (a PCRE_EXTRA facility).
3400    
3401    
3402     Version 1.00 18-Nov-97
3403     ----------------------
3404    
3405     1. Added compile-time macros to support systems such as SunOS4 which don't have
3406     memmove() or strerror() but have other things that can be used instead.
3407    
3408     2. Arranged that "make clean" removes the executables.
3409    
3410    
3411 nigel 3 Version 0.99 27-Oct-97
3412     ----------------------
3413    
3414     1. Fixed bug in code for optimizing classes with only one character. It was
3415     initializing a 32-byte map regardless, which could cause it to run off the end
3416     of the memory it had got.
3417    
3418     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3419    
3420    
3421     Version 0.98 22-Oct-97
3422     ----------------------
3423    
3424     1. Fixed bug in code for handling temporary memory usage when there are more
3425     back references than supplied space in the ovector. This could cause segfaults.
3426    
3427    
3428     Version 0.97 21-Oct-97
3429     ----------------------
3430    
3431     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3432    
3433     2. Optimized negated single characters not to use a bit map.
3434    
3435     3. Brought error texts together as macro definitions; clarified some of them;
3436     fixed one that was wrong - it said "range out of order" when it meant "invalid
3437     escape sequence".
3438    
3439     4. Changed some char * arguments to const char *.
3440    
3441     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3442    
3443     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3444     pcretest.
3445    
3446    
3447     Version 0.96 16-Oct-97
3448     ----------------------
3449    
3450     1. Added a simple "pgrep" utility to the distribution.
3451    
3452     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3453     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3454     where "ddd" means "one or more decimal digits".
3455    
3456     3. Fixed serious bug. If a pattern had a back reference, but the call to
3457     pcre_exec() didn't supply a large enough ovector to record the related
3458     identifying subpattern, the match always failed. PCRE now remembers the number
3459     of the largest back reference, and gets some temporary memory in which to save
3460     the offsets during matching if necessary, in order to ensure that
3461     backreferences always work.
3462    
3463     4. Increased the compatibility with Perl in a number of ways:
3464    
3465     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3466     to request this handling. The option can be set at compile or exec time.
3467    
3468     (b) $ matches before a terminating newline by default; an option
3469     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3470     mode). The option can be set at compile or exec time.
3471    
3472     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3473     the same as Perl's. If the decimal number it represents is less than 10
3474     or there aren't that many previous left capturing parentheses, an octal
3475     escape is read. Inside a character class, it's always an octal escape,
3476     even if it is a single digit.
3477    
3478     (d) An escaped but undefined alphabetic character is taken as a literal,
3479     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3480     escapes.
3481    
3482     (e) {0} is now permitted. (The previous item is removed from the compiled
3483     pattern).
3484    
3485     5. Changed all the names of code files so that the basic parts are no longer
3486     than 10 characters, and abolished the teeny "globals.c" file.
3487    
3488     6. Changed the handling of character classes; they are now done with a 32-byte
3489     bit map always.
3490    
3491     7. Added the -d and /D options to pcretest to make it possible to look at the
3492     internals of compilation without having to recompile pcre.
3493    
3494    
3495     Version 0.95 23-Sep-97
3496     ----------------------
3497    
3498     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3499     \x20 at the start of a run of normal characters. These were being treated as
3500     real characters, instead of the source characters being re-checked.
3501    
3502    
3503     Version 0.94 18-Sep-97
3504     ----------------------
3505    
3506     1. The functions are now thread-safe, with the caveat that the global variables
3507     containing pointers to malloc() and free() or alternative functions are the
3508     same for all threads.
3509    
3510     2. Get pcre_study() to generate a bitmap of initial characters for non-
3511     anchored patterns when this is possible, and use it if passed to pcre_exec().
3512    
3513    
3514     Version 0.93 15-Sep-97
3515     ----------------------
3516    
3517     1. /(b)|(:+)/ was computing an incorrect first character.
3518    
3519     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3520     but not actually doing anything yet.
3521    
3522     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3523     as Perl does (e.g. [-az] or [az-]).
3524    
3525     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3526     all possible positions.
3527    
3528     5. Split up into different modules to avoid including unneeded functions in a
3529     compiled binary. However, compile and exec are still in one module. The "study"
3530     function is split off.
3531    
3532     6. The character tables are now in a separate module whose source is generated
3533     by an auxiliary program - but can then be edited by hand if required. There are
3534     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3535     toupper() in the code.
3536    
3537     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3538     make them global. Abolish the function for setting them, as the caller can now
3539     set them directly.
3540    
3541    
3542     Version 0.92 11-Sep-97
3543     ----------------------
3544    
3545     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3546     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3547    
3548     2. Caseless matching was not working in character classes if the characters in
3549     the pattern were in upper case.
3550    
3551     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3552    
3553     4. Make PCRE_ANCHORED public and accept as a compile option.
3554    
3555     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3556     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3557     pass them.
3558    
3559     6. Give an error if bad option bits passed at compile or run time.
3560    
3561     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3562     pcretest to cause it to pass that flag.
3563    
3564     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3565     options, and the first character, if set.
3566    
3567     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3568    
3569    
3570     Version 0.91 10-Sep-97
3571     ----------------------
3572    
3573     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3574     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3575    
3576     2. PCRE was looping on encountering an indefinitely repeated back reference to
3577     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3578     Perl does - treats the match as successful.
3579    
3580     ****

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