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Revision 447 - (hide annotations) (download)
Tue Sep 15 18:17:54 2009 UTC (5 years, 1 month ago) by ph10
File size: 172757 byte(s)
Capture data when (*ACCEPT) is inside capturing parentheses.

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8     was out-of-date, and there was no check on the pcre_compile() error code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 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
47     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
48     character. Chaos in the form of incorrect output or a compiling loop could
49     result.
50 ph10 426
51     9. The restrictions on what a pattern can contain when partial matching is
52     requested for pcre_exec() have been removed. All patterns can now be
53     partially matched by this function. In addition, if there are at least two
54 ph10 435 slots in the offset vector, the offset of the earliest inspected character
55     for the match and the offset of the end of the subject are set in them when
56     PCRE_ERROR_PARTIAL is returned.
57 ph10 426
58 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
59     synonymous with PCRE_PARTIAL, for backwards compatibility, and
60     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
61     and may be more useful for multi-segment matching, especially with
62     pcre_exec().
63 ph10 427
64 ph10 428 11. Partial matching with pcre_exec() is now more intuitive. A partial match
65     used to be given if ever the end of the subject was reached; now it is
66     given only if matching could not proceed because another character was
67     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
68     string "Z", which now yields "no match" instead of "partial match". In the
69     case of pcre_dfa_exec(), "no match" is given if every matching path for the
70     final character ended with (*FAIL).
71    
72     12. Restarting a match using pcre_dfa_exec() after a partial match did not work
73     if the pattern had a "must contain" character that was already found in the
74     earlier partial match, unless partial matching was again requested. For
75     example, with the pattern /dog.(body)?/, the "must contain" character is
76     "g". If the first part-match was for the string "dog", restarting with
77 ph10 435 "sbody" failed. This bug has been fixed.
78 ph10 428
79 ph10 435 13. The string returned by pcre_dfa_exec() after a partial match has been
80     changed so that it starts at the first inspected character rather than the
81     first character of the match. This makes a difference only if the pattern
82     starts with a lookbehind assertion or \b or \B (\K is not supported by
83     pcre_dfa_exec()). It's an incompatible change, but it makes the two
84     matching functions compatible, and I think it's the right thing to do.
85    
86     14. Added a pcredemo man page, created automatically from the pcredemo.c file,
87 ph10 429 so that the demonstration program is easily available in environments where
88     PCRE has not been installed from source.
89    
90 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
91 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
92     library.
93    
94 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
95 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
96     is not the first non-POSIX option to be added. Clearly some people find
97 ph10 433 these options useful.
98 ph10 432
99 ph10 435 17. If a caller to the POSIX matching function regexec() passes a non-zero
100 ph10 438 value for nmatch with a NULL value for pmatch, the value of
101     nmatch is forced to zero.
102 ph10 433
103 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
104     the diff command, as RunTest does. It now checks in the same way as
105     RunTest, and also checks for the -b option.
106    
107 ph10 438 19. If an odd number of negated classes containing just a single character
108     interposed, within parentheses, between a forward reference to a named
109     subpattern and the definition of the subpattern, compilation crashed with
110     an internal error, complaining that it could not find the referenced
111     subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
112     [The bug was that it was starting one character too far in when skipping
113     over the character class, thus treating the ] as data rather than
114     terminating the class. This meant it could skip too much.]
115    
116 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
117     /g option in pcretest when the pattern contains \K, which makes it possible
118     to have an empty string match not at the start, even when the pattern is
119     anchored. Updated pcretest and pcredemo to use this option.
120    
121 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
122     than the maximum at the outer level, the higher number was returned, but
123     with unset values at the outer level. The correct (outer level) value is
124     now given.
125    
126 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
127     PCRE did not set those parentheses (unlike Perl). I have now found a way to
128     make it do so. The string so far is captured, making this feature
129     compatible with Perl.
130    
131 ph10 418
132 ph10 412 Version 7.9 11-Apr-09
133 ph10 376 ---------------------
134    
135 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
136 ph10 376 (pcretest), all targets were linked against these libraries. This included
137     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
138     libraries. This caused unwanted dependencies to be created. This problem
139 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
140 ph10 376 pcretest is linked with readline.
141 ph10 392
142 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
143     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
144     moved outside it again, because FALSE and TRUE are already defined in AIX,
145     but BOOL is not.
146 ph10 392
147     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
148 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
149 ph10 392
150 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
151     hyphens) following file names and line numbers when outputting matching
152 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
153 ph10 376 wording for the --colour (or --color) option.
154 ph10 392
155 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
156     was not coloured; this is different to GNU grep, so I have changed it to be
157     the same.
158 ph10 392
159 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
160 ph10 392 each matching line was coloured. Now it goes on to look for further matches
161     of any of the test patterns, which is the same behaviour as GNU grep.
162    
163     7. A pattern that could match an empty string could cause pcregrep to loop; it
164     doesn't make sense to accept an empty string match in pcregrep, so I have
165 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
166     seems to be how GNU grep behaves.
167 ph10 392
168 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
169 ph10 392 start or after a newline", because the conditional assertion was not being
170     correctly handled. The rule now is that both the assertion and what follows
171     in the first alternative must satisfy the test.
172    
173 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
174 ph10 399 condition was an assertion, PCRE could crash during matching, both with
175     pcre_exec() and pcre_dfa_exec().
176 ph10 392
177     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
178     used for matching.
179    
180     11. Unicode property support in character classes was not working for
181 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
182 ph10 388
183 ph10 392 12. Added the -M command line option to pcretest.
184    
185 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
186 ph10 389
187     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
188 ph10 390
189 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
190 ph10 390 wrapper.
191 ph10 392
192 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
193 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
194 ph10 391 string constants.
195 ph10 405
196 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
197     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
198 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
199     these, but not everybody uses configure.
200    
201     19. A conditional group that had only one branch was not being correctly
202     recognized as an item that could match an empty string. This meant that an
203     enclosing group might also not be so recognized, causing infinite looping
204     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
205     with the subject "ab", where knowledge that the repeated group can match
206 ph10 396 nothing is needed in order to break the loop.
207 ph10 405
208 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
209 ph10 405 exec(), but without supplying a callout function, matching went wrong.
210    
211     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
212     leak if the size of the offset vector was greater than 30. When the vector
213     is smaller, the saved offsets during recursion go onto a local stack
214     vector, but for larger vectors malloc() is used. It was failing to free
215     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
216 ph10 400 error, in fact).
217 ph10 405
218 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
219 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
220     problem, but was untidy.
221 ph10 376
222 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
223     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
224     included within another project.
225 ph10 411
226 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
227     slightly modified by me:
228 ph10 411
229     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
230     not building pcregrep.
231    
232 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
233 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
234    
235 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
236     duplicate group numbers, could behave incorrectly or give incorrect errors,
237     because when scanning forward to find the reference group, PCRE was not
238     taking into account the duplicate group numbers. A pattern such as
239     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
240 ph10 411
241     26. Changed a few more instances of "const unsigned char *" to USPTR, making
242     the feature of a custom pointer more persuasive (as requested by a user).
243 ph10 416
244 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
245 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
246     pre-defined.
247 ph10 392
248 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
249    
250 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
251     in the configuration summary.
252 ph10 405
253 ph10 411
254 ph10 374 Version 7.8 05-Sep-08
255 ph10 349 ---------------------
256    
257     1. Replaced UCP searching code with optimized version as implemented for Ad
258     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
259 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
260     to 5 times on some simple patterns that I tested. Permission was given to
261     distribute the MultiStage2.py script that generates the tables (it's not in
262     the tarball, but is in the Subversion repository).
263 ph10 349
264 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
265     scripts.
266 ph10 358
267 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
268     a group with a zero qualifier. The result of the study could be incorrect,
269 ph10 358 or the function might crash, depending on the pattern.
270    
271     4. Caseless matching was not working for non-ASCII characters in back
272 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
273 ph10 358 It now works when Unicode Property Support is available.
274    
275 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
276     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
277     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
278 ph10 358 truncation.
279 ph10 349
280 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
281    
282 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
283     pointers, in case they are 64-bit values.
284 ph10 371
285     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
286     test 2 if it fails.
287    
288 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
289 ph10 371 and a #define of that name to empty if it is not externally set. This is to
290     allow users of MSVC to set it if necessary.
291    
292     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
293 ph10 359 the convenience functions in the pcre_get.c source file.
294 ph10 371
295 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
296     could cause overwriting and/or a crash. This command provoked a crash in
297 ph10 371 some environments:
298    
299     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
300    
301 ph10 360 This potential security problem was recorded as CVE-2008-2371.
302 ph10 371
303 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
304     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
305 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
306 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
307     pcretest so that it places the subject at the end of its malloc-ed buffer.
308 ph10 371
309 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
310 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
311    
312 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
313 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
314     first line. This applied both to normal and DFA matching.
315    
316 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
317 ph10 371 /^[^d]*?$/8 failed to match "abc".
318 ph10 351
319 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
320    
321     17. Make it more clear in the documentation that values returned from
322 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
323 ph10 357
324 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
325 ph10 368
326 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
327     supplied by Stefan Weber. I made a further small update for 7.8 because
328 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
329     replaced by pcre_ucd.c.
330 ph10 371
331 ph10 373
332 ph10 347 Version 7.7 07-May-08
333 ph10 321 ---------------------
334    
335     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
336 ph10 345 a string to a long long, pretend we don't even have a long long." This is
337 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
338 ph10 345
339 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
340     pre-7.6 versions, which defined a global no_arg variable instead of putting
341 ph10 332 it in the RE class. (See also #8 below.)
342 ph10 345
343     3. Remove a line of dead code, identified by coverity and reported by Nuno
344     Lopes.
345    
346 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
347 ph10 321
348 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
349 ph10 345 of files, instead of just to the final components.
350    
351 ph10 324 (2) If there was more than one level of directory, the subdirectories were
352     skipped unless they satisfied the include/exclude conditions. This is
353     inconsistent with GNU grep (and could even be seen as contrary to the
354     pcregrep specification - which I improved to make it absolutely clear).
355     The action now is always to scan all levels of directory, and just
356     apply the include/exclude patterns to regular files.
357 ph10 345
358 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
359 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
360    
361 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
362 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
363 ph10 326 doesn't support NULs in patterns.
364 ph10 345
365     7. Added some missing "const"s to declarations of static tables in
366     pcre_compile.c and pcre_dfa_exec.c.
367    
368 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
369 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
370 ph10 345 first patch. And a third patch - this was a messy problem.)
371 ph10 321
372 ph10 345 9. Applied Craig's patch to remove the use of push_back().
373    
374 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
375     matching function regexec().
376 ph10 345
377     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
378     which, however, unlike Perl's \g{...}, are subroutine calls, not back
379 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
380     Oniguruma does).
381 ph10 345
382     12. Previously, a group with a zero repeat such as (...){0} was completely
383 ph10 335 omitted from the compiled regex. However, this means that if the group
384     was called as a subroutine from elsewhere in the pattern, things went wrong
385 ph10 345 (an internal error was given). Such groups are now left in the compiled
386     pattern, with a new opcode that causes them to be skipped at execution
387 ph10 335 time.
388 ph10 345
389 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
390     to the way PCRE behaves:
391 ph10 345
392 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
393 ph10 345
394     (b) A back reference to an unmatched subpattern matches an empty string
395 ph10 336 (Perl fails the current match path).
396 ph10 345
397 ph10 341 (c) A data ] in a character class must be notated as \] because if the
398 ph10 345 first data character in a class is ], it defines an empty class. (In
399 ph10 341 Perl it is not possible to have an empty class.) The empty class []
400     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
401     The negative empty class [^] matches any one character, independently
402     of the DOTALL setting.
403 ph10 345
404     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
405 ph10 340 non-existent subpattern following a character class starting with ']' and
406     containing () gave an internal compiling error instead of "reference to
407     non-existent subpattern". Fortunately, when the pattern did exist, the
408 ph10 345 compiled code was correct. (When scanning forwards to check for the
409 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
410 ph10 345 the class, so got the count wrong. When actually compiling, the reference
411 ph10 340 was subsequently set up correctly.)
412 ph10 345
413 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
414 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
415     other assertions are supported. I have made pcre_dfa_exec() support
416     (*FAIL).
417    
418 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
419 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
420     cannot be changed at match time, I realized I could make a small
421     improvement to matching performance by compiling OP_ALLANY instead of
422     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
423     on the OP_ANY path.
424    
425     17. Compiling pcretest on Windows with readline support failed without the
426 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
427 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
428    
429 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
430 ph10 345 ncurses library to be included for pcretest when ReadLine support is
431     requested, but also to allow for it to be overridden. This patch came from
432     Daniel Bergström.
433 ph10 347
434 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
435 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
436     any errors with the current Unicode tables. Thanks to Peter Kankowski for
437     spotting this.
438 ph10 324
439 ph10 332
440 ph10 319 Version 7.6 28-Jan-08
441 ph10 300 ---------------------
442    
443 ph10 302 1. A character class containing a very large number of characters with
444     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
445     overflow.
446 ph10 309
447     2. Patch to cut out the "long long" test in pcrecpp_unittest when
448     HAVE_LONG_LONG is not defined.
449    
450 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
451 ph10 304 bring them up to date and include new features. This patch includes:
452 ph10 309
453 ph10 304 - Fixed PH's badly added libz and libbz2 support.
454     - Fixed a problem with static linking.
455 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
456 ph10 304 - Fixed dftables problem and added an option.
457     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
458     HAVE_LONG_LONG.
459     - Added readline support for pcretest.
460 ph10 309 - Added an listing of the option settings after cmake has run.
461    
462 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
463     "pcre.dll" under mingw when using Configure/Make. I added stuff to
464     Makefile.am that cause it to include this special target, without
465     affecting anything else. Note that the same mingw target plus all
466     the other distribution libraries and programs are now supported
467     when configuring with CMake (see 6 below) instead of with
468     Configure/Make.
469 ph10 309
470 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
471     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
472 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
473     solves the problem, but it does no harm.
474 ph10 313
475 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
476 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
477 ph10 314 with CMake, and also correct the comment about stack recursion.
478 ph10 313
479 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
480 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
481     of a program that users should build themselves after PCRE is installed, so
482     building it automatically is not really right. What is more, it gave
483 ph10 312 trouble in some build environments.
484 ph10 300
485 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
486 ph10 308
487 ph10 319
488 ph10 298 Version 7.5 10-Jan-08
489 ph10 263 ---------------------
490    
491     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
492     values in parens when parsing an RE using the C++ wrapper."
493 ph10 286
494 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
495     Characters greater than 255 were excluded from the class instead of being
496     included.
497 ph10 286
498     3. The same bug as (2) above applied to negated POSIX classes such as
499 ph10 265 [:^space:].
500 ph10 286
501 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
502     defined or documented. It seems to have been a typo for PCRE_STATIC, so
503 ph10 286 I have changed it.
504    
505 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
506 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
507     first named subpattern whose name started with "a" (in other words, the
508 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
509     expected" is now given for (?&) (a zero-length name), and this patch also
510     makes it give the same error for \k'' (previously it complained that that
511     was a reference to a non-existent subpattern).
512 ph10 286
513 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
514 ph10 286 this is right because (?- can be followed by option settings as well as by
515 ph10 269 digits. I have, however, made the messages clearer.
516 ph10 286
517 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
518     than the number used in the conditional) now cause a compile-time error.
519     This is actually not compatible with Perl, which accepts such patterns, but
520     treats the conditional as always being FALSE (as PCRE used to), but it
521     seems to me that giving a diagnostic is better.
522 ph10 286
523 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
524 ph10 275 and messages.
525 ph10 286
526     9. Fix two occurrences of "backslash" in comments that should have been
527     "backspace".
528    
529     10. Remove two redundant lines of code that can never be obeyed (their function
530     was moved elsewhere).
531    
532     11. The program that makes PCRE's Unicode character property table had a bug
533     which caused it to generate incorrect table entries for sequences of
534 ph10 277 characters that have the same character type, but are in different scripts.
535 ph10 286 It amalgamated them into a single range, with the script of the first of
536 ph10 277 them. In other words, some characters were in the wrong script. There were
537     thirteen such cases, affecting characters in the following ranges:
538 ph10 286
539 ph10 277 U+002b0 - U+002c1
540     U+0060c - U+0060d
541 ph10 286 U+0061e - U+00612
542 ph10 277 U+0064b - U+0065e
543     U+0074d - U+0076d
544     U+01800 - U+01805
545     U+01d00 - U+01d77
546     U+01d9b - U+01dbf
547     U+0200b - U+0200f
548     U+030fc - U+030fe
549     U+03260 - U+0327f
550     U+0fb46 - U+0fbb1
551     U+10450 - U+1049d
552 ph10 286
553 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
554     compatible with GNU grep in that, if there was more than one match in a
555     line, it showed only the first of them. It now behaves in the same way as
556     GNU grep.
557 ph10 286
558     13. If the -o and -v options were combined for pcregrep, it printed a blank
559     line for every non-matching line. GNU grep prints nothing, and pcregrep now
560     does the same. The return code can be used to tell if there were any
561     non-matching lines.
562    
563 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
564    
565     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
566 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
567 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
568     and both kinds of lookbehind were skipped).
569    
570 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
571 ph10 284 inclusion of <windows.h> to before rather than after the definition of
572     INVALID_FILE_ATTRIBUTES (patch from David Byron).
573 ph10 263
574 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
575 ph10 286 character property caused pcre_compile() to compile bad code, which led at
576     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
577     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
578     caused the error; without that there was no problem.
579 ph10 263
580 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
581 ph10 286
582 ph10 289 19. Added --enable-pcretest-libreadline.
583 ph10 286
584 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
585 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
586 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
587     later patch that removed the other one (the right fix) and added unit tests
588     that check the return values (which was not done before).
589 ph10 292
590 ph10 291 21. Several CMake things:
591 ph10 287
592 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
593 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
594 ph10 288
595 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
596     linked with the newly-built libraries, not previously installed ones.
597 ph10 291
598 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
599 ph10 298
600     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
601     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
602     UTF-8 newline character). The key issue is that the pattern starts .*;
603     this means that the match must be either at the beginning, or after a
604     newline. The bug was in the code for advancing after a failed match and
605     checking that the new position followed a newline. It was not taking
606 ph10 294 account of UTF-8 characters correctly.
607 ph10 298
608     23. PCRE was behaving differently from Perl in the way it recognized POSIX
609     character classes. PCRE was not treating the sequence [:...:] as a
610     character class unless the ... were all letters. Perl, however, seems to
611     allow any characters between [: and :], though of course it rejects as
612     unknown any "names" that contain non-letters, because all the known class
613     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
614     for example, whereas PCRE did not - it did not recognize a POSIX character
615     class. This seemed a bit dangerous, so the code has been changed to be
616     closer to Perl. The behaviour is not identical to Perl, because PCRE will
617     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
618     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
619     Perl does, and where it didn't before.
620    
621 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
622     Windows environments %n is disabled by default.
623 ph10 292
624    
625 ph10 260 Version 7.4 21-Sep-07
626 ph10 230 ---------------------
627    
628     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
629 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
630     LF". That isn't really right - the whole point of the change was to try to
631     help when there was an actual mention of one of the two characters. So now
632     the change happens only if \r or \n (or a literal CR or LF) character is
633 ph10 230 encountered.
634 ph10 231
635     2. The 32-bit options word was also used for 6 internal flags, but the numbers
636     of both had grown to the point where there were only 3 bits left.
637     Fortunately, there was spare space in the data structure, and so I have
638     moved the internal flags into a new 16-bit field to free up more option
639 ph10 230 bits.
640 ph10 231
641     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
642     but did not set the internal JCHANGED flag - either of these is enough to
643     control the way the "get" function works - but the PCRE_INFO_JCHANGED
644     facility is supposed to tell if (?J) was ever used, so now (?J) at the
645 ph10 230 start sets both bits.
646    
647 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
648     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
649 ph10 230
650 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
651    
652     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
653 ph10 233 compatibility, even though it is no longer used.
654 ph10 243
655     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
656 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
657 ph10 259 windows.h file is present (where different names are used). [This was
658 ph10 257 reversed later after testing - see 16 below.]
659 ph10 243
660     8. Changed all #include <config.h> to #include "config.h". There were also
661 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
662 ph10 243
663 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
664 ph10 243 sequence off the lines that it output.
665    
666     10. It was pointed out to me that arrays of string pointers cause lots of
667     relocations when a shared library is dynamically loaded. A technique of
668     using a single long string with a table of offsets can drastically reduce
669     these. I have refactored PCRE in four places to do this. The result is
670 ph10 240 dramatic:
671 ph10 243
672 ph10 240 Originally: 290
673     After changing UCP table: 187
674 ph10 243 After changing error message table: 43
675 ph10 240 After changing table of "verbs" 36
676     After changing table of Posix names 22
677 ph10 243
678 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
679 ph10 247
680 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
681 ph10 247 unicode-properties was also set.
682    
683 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
684 ph10 231
685 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
686     checked only for CRLF.
687 ph10 233
688 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
689    
690 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
691 ph10 253
692 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
693 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
694     entirely. This removes changes made in 7 above.
695 ph10 256
696 ph10 261 17. The CMake files have been updated, and there is now more information about
697     building with CMake in the NON-UNIX-USE document.
698 ph10 257
699 ph10 261
700 ph10 228 Version 7.3 28-Aug-07
701 ph10 157 ---------------------
702    
703 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
704     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
705     brackets there is not right, since it causes compilers to look for an
706     installed pcre.h, not the version that is in the source that is being
707     compiled (which of course may be different). I have changed it back to:
708 ph10 197
709 ph10 189 #include "pcre.h"
710 ph10 197
711     I have a vague recollection that the change was concerned with compiling in
712     different directories, but in the new build system, that is taken care of
713     by the VPATH setting the Makefile.
714    
715 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
716     when the subject happened to end in the byte 0x85 (e.g. if the last
717     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
718     characters but of course it shouldn't be taken as a newline when it is part
719     of another character. The bug was that, for an unlimited repeat of . in
720     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
721     characters when looking for a newline.
722 ph10 197
723     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
724    
725     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
726     in debug output.
727    
728 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
729     long printing in the pcrecpp unittest when running under MinGW.
730 ph10 189
731 ph10 197 6. ESC_K was left out of the EBCDIC table.
732 ph10 189
733 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
734     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
735     limit also applies to "virtual nesting" when a pattern is recursive, and in
736     this case 1000 isn't so big. I have been able to remove this limit at the
737     expense of backing off one optimization in certain circumstances. Normally,
738     when pcre_exec() would call its internal match() function recursively and
739     immediately return the result unconditionally, it uses a "tail recursion"
740     feature to save stack. However, when a subpattern that can match an empty
741     string has an unlimited repetition quantifier, it no longer makes this
742     optimization. That gives it a stack frame in which to save the data for
743     checking that an empty string has been matched. Previously this was taken
744     from the 1000-entry workspace that had been reserved. So now there is no
745     explicit limit, but more stack is used.
746 ph10 189
747 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
748     syntax that is required for Windows, and which was going wrong for the
749     pcreposix and pcrecpp parts of the library. These were overlooked when this
750     problem was solved for the main library.
751 ph10 197
752 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
753     the size of patterns that contain repeated groups with explicit upper
754     limits. As the maximum quantifier is 65535, the maximum group length was
755     set at 30,000 so that the product of these two numbers did not overflow a
756     32-bit integer. However, it turns out that people want to use groups that
757     are longer than 30,000 bytes (though not repeat them that many times).
758     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
759     made it possible to implement the integer overflow checks in a much more
760     dynamic way, which I have now done. The artificial limitation on group
761     length has been removed - we now have only the limit on the total length of
762     the compiled pattern, which depends on the LINK_SIZE setting.
763 ph10 208
764     10. Fixed a bug in the documentation for get/copy named substring when
765     duplicate names are permitted. If none of the named substrings are set, the
766     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
767     empty string.
768    
769     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
770     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
771     because the ] is interpreted as the first data character and the
772     terminating ] is not found. PCRE has been made compatible with Perl in this
773     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
774     cause memory overwriting.
775    
776 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
777     string has been matched (to stop an infinite loop). It was not recognizing
778 ph10 208 a conditional subpattern that could match an empty string if that
779 ph10 206 subpattern was within another subpattern. For example, it looped when
780 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
781 ph10 206 condition was not nested. This bug has been fixed.
782 ph10 208
783 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
784     past the start of the subject in the presence of bytes with the top bit
785     set, for example "\x8aBCD".
786 ph10 211
787 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
788     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
789 ph10 200
790 ph10 211 14. Optimized (?!) to (*FAIL).
791 ph10 202
792 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
793     This restricts code points to be within the range 0 to 0x10FFFF, excluding
794     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
795     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
796     does: it's just the validity check that is more restrictive.
797 ph10 220
798     16. Inserted checks for integer overflows during escape sequence (backslash)
799     processing, and also fixed erroneous offset values for syntax errors during
800     backslash processing.
801    
802 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
803 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
804    
805 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
806     caused an overrun.
807 ph10 220
808     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
809     something other than just ASCII characters) inside a group that had an
810     unlimited repeat caused a loop at compile time (while checking to see
811     whether the group could match an empty string).
812    
813 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
814     [\P{Any}] did so. (Error in the code for printing property names.)
815 ph10 210
816 ph10 220 21. An orphan \E inside a character class could cause a crash.
817    
818     22. A repeated capturing bracket such as (A)? could cause a wild memory
819 ph10 218 reference during compilation.
820 ph10 220
821     23. There are several functions in pcre_compile() that scan along a compiled
822     expression for various reasons (e.g. to see if it's fixed length for look
823 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
824 ph10 220 present in the pattern. These operators have additional parameters compared
825     with \d, etc, and these were not being taken into account when moving along
826 ph10 218 the compiled data. Specifically:
827 ph10 220
828     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
829     length.
830    
831     (b) An item such as \pL+ within a repeated group could cause crashes or
832 ph10 218 loops.
833 ph10 220
834 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
835 ph10 220 "reference to non-existent subpattern" error.
836    
837 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
838    
839 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
840 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
841 ph10 211
842 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
843 ph10 218
844 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
845 ph10 223 character were causing crashes (broken optimization).
846 ph10 227
847 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
848 ph10 227 \p or \P) caused a compile-time loop.
849    
850 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
851     break. For example, the unstudied pattern [\r\n]A does not match the string
852     "\r\nA" because change 7.0/46 below moves the current point on by two
853     characters after failing to match at the start. However, the pattern \nA
854 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
855     the same is true. There doesn't seem any very clean way out of this, but
856     what I have chosen to do makes the common cases work: PCRE now takes note
857     of whether there can be an explicit match for \r or \n anywhere in the
858     pattern, and if so, 7.0/46 no longer applies. As part of this change,
859     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
860     pattern has explicit CR or LF references.
861 ph10 222
862 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
863 ph10 223
864 ph10 227
865 ph10 189 Version 7.2 19-Jun-07
866     ---------------------
867    
868 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
869     which is apparently normally available under Windows.
870 ph10 159
871     2. Re-jig the pcregrep tests with different newline settings in an attempt
872     to make them independent of the local environment's newline setting.
873 ph10 157
874 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
875 ph10 165
876 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
877     was not 2, because the output contained actual offsets. The recent new
878 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
879     usable with all link sizes.
880    
881 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
882     stack recursion. This gives a massive performance boost under BSD, but just
883 ph10 165 a small improvement under Linux. However, it saves one field in the frame
884 ph10 164 in all cases.
885 ph10 172
886 ph10 166 6. Added more features from the forthcoming Perl 5.10:
887 ph10 172
888 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
889     recursion call. It refers to the nth most recently opened parentheses.
890 ph10 172
891 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
892 ph10 172 to be opened parentheses.
893    
894     (c) Conditions that refer to capturing parentheses can be specified
895 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
896 ph10 172
897 ph10 168 (d) \K resets the start of the current match so that everything before
898 ph10 172 is not part of it.
899    
900 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
901 ph10 172
902 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
903 ph10 172 reference syntax.
904 ph10 182
905 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
906 ph10 182 alternative starts with the same number.
907 ph10 172
908 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
909    
910 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
911     PCRE_INFO_JCHANGED.
912    
913     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
914     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
915 ph10 170 for detecting groups that can match an empty string.
916 ph10 159
917 ph10 172 9. A pattern with a very large number of alternatives (more than several
918     hundred) was running out of internal workspace during the pre-compile
919     phase, where pcre_compile() figures out how much memory will be needed. A
920     bit of new cunning has reduced the workspace needed for groups with
921     alternatives. The 1000-alternative test pattern now uses 12 bytes of
922     workspace instead of running out of the 4096 that are available.
923 ph10 182
924 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
925 ph10 172
926 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
927     The report of the bug said:
928 ph10 182
929 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
930     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
931 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
932 ph10 185
933 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
934 ph10 185 it matched the wrong number of bytes.
935 ph10 172
936 ph10 179
937 ph10 155 Version 7.1 24-Apr-07
938 ph10 98 ---------------------
939    
940 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
941 ph10 122 that is more "standard", making use of automake and other Autotools. There
942 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
943     on this.
944 ph10 111
945     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
946     for recursive directory scanning broke on some systems because the files
947     are not scanned in any specific order and on different systems the order
948     was different. A call to "sort" has been inserted into RunGrepTest for the
949     approprate test as a short-term fix. In the longer term there may be an
950 ph10 100 alternative.
951 ph10 111
952 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
953 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
954     people do their own conversions for various reasons). The problems
955     concerned the use of low-level troff macros .br and .in. I have therefore
956     removed all such uses from the man pages (some were redundant, some could
957 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
958     HTML has been updated to handle .nf/.fi and to complain if it encounters
959     .br or .in.
960 ph10 111
961 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
962 ph10 123 arranged for config.h to be included in the distribution, with the name
963 ph10 111 config.h.generic, for the benefit of those who have to compile without
964     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
965    
966     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
967     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
968 ph10 127 makevp.bat for the current PCRE, using the additional files
969 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
970 ph10 111
971     6. A Windows user reported a minor discrepancy with test 2, which turned out
972     to be caused by a trailing space on an input line that had got lost in his
973 ph10 102 copy. The trailing space was an accident, so I've just removed it.
974 ph10 111
975 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
976 ph10 111 that is needed.
977    
978 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
979     as "const" (a) because they are and (b) because it helps the PHP
980     maintainers who have recently made a script to detect big data structures
981 ph10 111 in the php code that should be moved to the .rodata section. I remembered
982     to update Builducptable as well, so it won't revert if ucptable.h is ever
983 ph10 105 re-created.
984 ph10 111
985     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
986 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
987 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
988     support is not required. This saves 1.5-2K of code, which is important in
989 ph10 107 some applications.
990 ph10 111
991 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
992 ph10 111 so as not to refer to the tables, even though these functions will never be
993     called when UTF-8 support is disabled. Otherwise there are problems with a
994     shared library.
995    
996 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
997    
998     (a) It was defining its arguments as char * instead of void *.
999    
1000 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1001     a long time ago when I wrote it, but is no longer the case.
1002    
1003 ph10 118 The emulated memove() is provided for those environments that have neither
1004 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1005 ph10 118 is clearly not the case, as these two bugs were recently reported.
1006 ph10 123
1007 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1008 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1009     pages, and it removes trailing spaces from listed files. It also creates
1010     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1011     case, it wraps all the #defines with #ifndefs. This script should be run
1012 ph10 111 before "make dist".
1013 ph10 123
1014 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1015     with Unicode property support.
1016 ph10 123
1017     (a) For a maximizing quantifier, if the two different cases of the
1018     character were of different lengths in their UTF-8 codings (there are
1019     some cases like this - I found 11), and the matching function had to
1020 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1021     were both the same length.
1022 ph10 123
1023     (b) When PCRE was configured to use the heap rather than the stack for
1024     recursion during matching, it was not correctly preserving the data for
1025     the other case of a UTF-8 character when checking ahead for a match
1026     while processing a minimizing repeat. If the check also involved
1027 ph10 115 matching a wide character, but failed, corruption could cause an
1028     erroneous result when trying to check for a repeat of the original
1029     character.
1030 ph10 123
1031 ph10 116 13. Some tidying changes to the testing mechanism:
1032 ph10 98
1033 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1034     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1035 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1036     this for UTF-8.) The configure.ac script no longer substitutes the
1037     relevant variables.
1038    
1039 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1040     with length and offset values. This means that the output is different
1041     for different internal link sizes. Test 2 is skipped for link sizes
1042     other than 2 because of this, bypassing the problem. Unfortunately,
1043     there was also a test in test 3 (the locale tests) that used /B and
1044 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1045     I have added a new /Z option to pcretest that replaces the length and
1046     offset values with spaces. This is now used to make test 3 independent
1047 ph10 122 of link size. (Test 2 will be tidied up later.)
1048 ph10 123
1049     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1050 ph10 122 segmentation fault instead of returning the appropriate error message.
1051 ph10 134
1052 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1053 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1054     This doesn't seem right; it now treats the CRLF combination as the line
1055     ending, and so does not match in that case. It's only a pattern such as ^$
1056     that would hit this one: something like ^ABC$ would have failed after \r
1057     and then tried again after \r\n.
1058    
1059 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1060 ph10 134 in an attempt to make files that differ only in their line terminators
1061     compare equal. This works on Linux.
1062 ph10 142
1063 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1064     as it exited. This is now fixed, thanks to valgrind.
1065 ph10 142
1066 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1067 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1068     was because its rules for how to advance for /g after matching an empty
1069 ph10 143 string at the end of a line did not allow for this case. They now check for
1070     it specially.
1071 ph10 150
1072     20. pcretest is supposed to handle patterns and data of any length, by
1073     extending its buffers when necessary. It was getting this wrong when the
1074 ph10 147 buffer for a data line had to be extended.
1075 ph10 150
1076 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1077 ph10 150 CRLF as a newline sequence.
1078 ph10 152
1079 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1080 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1081     I have nevertheless tidied it up.
1082 ph10 111
1083 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1084 ph10 123
1085 ph10 153 24. Added a man page for pcre-config.
1086 ph10 152
1087 ph10 153
1088 nigel 93 Version 7.0 19-Dec-06
1089     ---------------------
1090    
1091     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1092     moving to gcc 4.1.1.
1093    
1094     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1095     sys/time.h, which is documented as needed for this function. It doesn't
1096     seem to matter on Linux, but it showed up on some releases of OS X.
1097    
1098     3. It seems that there are systems where bytes whose values are greater than
1099     127 match isprint() in the "C" locale. The "C" locale should be the
1100     default when a C program starts up. In most systems, only ASCII printing
1101     characters match isprint(). This difference caused the output from pcretest
1102     to vary, making some of the tests fail. I have changed pcretest so that:
1103    
1104     (a) When it is outputting text in the compiled version of a pattern, bytes
1105     other than 32-126 are always shown as hex escapes.
1106    
1107     (b) When it is outputting text that is a matched part of a subject string,
1108     it does the same, unless a different locale has been set for the match
1109     (using the /L modifier). In this case, it uses isprint() to decide.
1110    
1111     4. Fixed a major bug that caused incorrect computation of the amount of memory
1112     required for a compiled pattern when options that changed within the
1113     pattern affected the logic of the preliminary scan that determines the
1114     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1115     that the computed length was too small. The symptoms of this bug were
1116     either the PCRE error "internal error: code overflow" from pcre_compile(),
1117     or a glibc crash with a message such as "pcretest: free(): invalid next
1118     size (fast)". Examples of patterns that provoked this bug (shown in
1119     pcretest format) are:
1120    
1121     /(?-x: )/x
1122     /(?x)(?-x: \s*#\s*)/
1123     /((?i)[\x{c0}])/8
1124     /(?i:[\x{c0}])/8
1125    
1126     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1127     is now done differently.
1128    
1129     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1130     wrapper classes; (b) implement a new function in the C++ scanner that is
1131     more efficient than the old way of doing things because it avoids levels of
1132     recursion in the regex matching; (c) add a paragraph to the documentation
1133     for the FullMatch() function.
1134    
1135     6. The escape sequence \n was being treated as whatever was defined as
1136     "newline". Not only was this contrary to the documentation, which states
1137     that \n is character 10 (hex 0A), but it also went horribly wrong when
1138     "newline" was defined as CRLF. This has been fixed.
1139    
1140     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1141     was being set to -1 for the "end of line" case (supposedly a value that no
1142     character can have). Though this value is never used (the check for end of
1143     line is "zero bytes in current character"), it caused compiler complaints.
1144     I've changed it to 0xffffffff.
1145    
1146     8. In pcre_version.c, the version string was being built by a sequence of
1147     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1148     string (as it is for production releases) called a macro with an empty
1149     argument. The C standard says the result of this is undefined. The gcc
1150     compiler treats it as an empty string (which was what was wanted) but it is
1151     reported that Visual C gives an error. The source has been hacked around to
1152     avoid this problem.
1153    
1154     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1155     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1156     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1157     of them did).
1158    
1159     10. Originally, pcretest opened its input and output without "b"; then I was
1160     told that "b" was needed in some environments, so it was added for release
1161     5.0 to both the input and output. (It makes no difference on Unix-like
1162     systems.) Later I was told that it is wrong for the input on Windows. I've
1163     now abstracted the modes into two macros, to make it easier to fiddle with
1164     them, and removed "b" from the input mode under Windows.
1165    
1166     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1167    
1168     12. Added -help and --help to pcretest as an official way of being reminded
1169     of the options.
1170    
1171     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1172     and pcrecpp.cc because they annoy compilers at high warning levels.
1173    
1174     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1175    
1176     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1177     scripts are not C programs :-) and which was not noticed because it works
1178     on Linux.
1179    
1180     16. pcretest is supposed to handle any length of pattern and data line (as one
1181     line or as a continued sequence of lines) by extending its input buffer if
1182     necessary. This feature was broken for very long pattern lines, leading to
1183     a string of junk being passed to pcre_compile() if the pattern was longer
1184     than about 50K.
1185    
1186     17. I have done a major re-factoring of the way pcre_compile() computes the
1187     amount of memory needed for a compiled pattern. Previously, there was code
1188     that made a preliminary scan of the pattern in order to do this. That was
1189     OK when PCRE was new, but as the facilities have expanded, it has become
1190     harder and harder to keep it in step with the real compile phase, and there
1191     have been a number of bugs (see for example, 4 above). I have now found a
1192     cunning way of running the real compile function in a "fake" mode that
1193     enables it to compute how much memory it would need, while actually only
1194     ever using a few hundred bytes of working memory and without too many
1195     tests of the mode. This should make future maintenance and development
1196     easier. A side effect of this work is that the limit of 200 on the nesting
1197     depth of parentheses has been removed (though this was never a serious
1198     limitation, I suspect). However, there is a downside: pcre_compile() now
1199     runs more slowly than before (30% or more, depending on the pattern). I
1200     hope this isn't a big issue. There is no effect on runtime performance.
1201    
1202     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1203     newline (only possible for the last line of a file) and it was a
1204     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1205    
1206     19. Added additional timing features to pcretest. (1) The -tm option now times
1207     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1208     separate command line item, by a number that specifies the number of
1209     repeats to use when timing. The default is 50000; this gives better
1210     precision, but takes uncomfortably long for very large patterns.
1211    
1212     20. Extended pcre_study() to be more clever in cases where a branch of a
1213     subpattern has no definite first character. For example, (a*|b*)[cd] would
1214     previously give no result from pcre_study(). Now it recognizes that the
1215     first character must be a, b, c, or d.
1216    
1217     21. There was an incorrect error "recursive call could loop indefinitely" if
1218     a subpattern (or the entire pattern) that was being tested for matching an
1219     empty string contained only one non-empty item after a nested subpattern.
1220     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1221     incorrectly, because the \d was being skipped in the check.
1222    
1223     22. The pcretest program now has a new pattern option /B and a command line
1224     option -b, which is equivalent to adding /B to every pattern. This causes
1225     it to show the compiled bytecode, without the additional information that
1226     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1227     is the same as /B/I).
1228    
1229     23. A new optimization is now able automatically to treat some sequences such
1230     as a*b as a*+b. More specifically, if something simple (such as a character
1231     or a simple class like \d) has an unlimited quantifier, and is followed by
1232     something that cannot possibly match the quantified thing, the quantifier
1233     is automatically "possessified".
1234    
1235     24. A recursive reference to a subpattern whose number was greater than 39
1236     went wrong under certain circumstances in UTF-8 mode. This bug could also
1237     have affected the operation of pcre_study().
1238    
1239     25. Realized that a little bit of performance could be had by replacing
1240     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1241    
1242     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1243    
1244     27. Possessive quantifiers such as a++ were previously implemented by turning
1245     them into atomic groups such as ($>a+). Now they have their own opcodes,
1246     which improves performance. This includes the automatically created ones
1247     from 23 above.
1248    
1249     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1250     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1251     the first matched character to be a colon. This applied both to named and
1252     numbered groups.
1253    
1254     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1255    
1256     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1257     building PCRE on Windows easier, so I have included it in the distribution.
1258    
1259     31. There is now a check in pcretest against a ridiculously large number being
1260     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1261     loop, the loop is abandoned.
1262    
1263     32. Forward references to subpatterns in conditions such as (?(2)...) where
1264     subpattern 2 is defined later cause pcre_compile() to search forwards in
1265     the pattern for the relevant set of parentheses. This search went wrong
1266     when there were unescaped parentheses in a character class, parentheses
1267     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1268    
1269     33. "Subroutine" calls and backreferences were previously restricted to
1270     referencing subpatterns earlier in the regex. This restriction has now
1271     been removed.
1272    
1273     34. Added a number of extra features that are going to be in Perl 5.10. On the
1274     whole, these are just syntactic alternatives for features that PCRE had
1275     previously implemented using the Python syntax or my own invention. The
1276     other formats are all retained for compatibility.
1277    
1278     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1279     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1280     also .NET compatible.
1281    
1282     (b) A recursion or subroutine call to a named group can now be defined as
1283     (?&name) as well as (?P>name).
1284    
1285     (c) A backreference to a named group can now be defined as \k<name> or
1286     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1287     5.10, are also .NET compatible.
1288    
1289     (d) A conditional reference to a named group can now use the syntax
1290     (?(<name>) or (?('name') as well as (?(name).
1291    
1292     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1293     groups (named and numbered) that are never evaluated inline, but can be
1294     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1295     is always false. There may be only one alternative in such a group.
1296    
1297     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1298     as the simple (?(R). The condition is true only if the most recent
1299     recursion is that of the given number or name. It does not search out
1300     through the entire recursion stack.
1301    
1302     (g) The escape \gN or \g{N} has been added, where N is a positive or
1303     negative number, specifying an absolute or relative reference.
1304    
1305     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1306     some "unreachable code" warnings.
1307    
1308     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1309     things, this adds five new scripts.
1310    
1311     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1312     There were also incompatibilities regarding the handling of \Q..\E inside
1313     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1314     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1315    
1316     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1317     matches an empty string, and forcibly breaks the loop. There were bugs in
1318     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1319     against aaaa the result was just "a" rather than "aaaa", for example. Two
1320     separate and independent bugs (that affected different cases) have been
1321     fixed.
1322    
1323     39. Refactored the code to abolish the use of different opcodes for small
1324     capturing bracket numbers. This is a tidy that I avoided doing when I
1325     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1326     The new approach is not only tidier, it makes it possible to reduce the
1327     memory needed to fix the previous bug (38).
1328    
1329     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1330     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1331     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1332     mode.
1333    
1334     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1335     report.
1336    
1337     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1338     copy construction and assignment in the C++ wrapper.
1339    
1340     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1341     couple of bugs that could have given wrong results in the "--newline=crlf"
1342     case.
1343    
1344     44. Added a number of casts and did some reorganization of signed/unsigned int
1345     variables following suggestions from Dair Grant. Also renamed the variable
1346     "this" as "item" because it is a C++ keyword.
1347    
1348     45. Arranged for dftables to add
1349    
1350     #include "pcre_internal.h"
1351    
1352     to pcre_chartables.c because without it, gcc 4.x may remove the array
1353     definition from the final binary if PCRE is built into a static library and
1354     dead code stripping is activated.
1355    
1356     46. For an unanchored pattern, if a match attempt fails at the start of a
1357     newline sequence, and the newline setting is CRLF or ANY, and the next two
1358     characters are CRLF, advance by two characters instead of one.
1359    
1360    
1361 nigel 91 Version 6.7 04-Jul-06
1362     ---------------------
1363    
1364     1. In order to handle tests when input lines are enormously long, pcretest has
1365     been re-factored so that it automatically extends its buffers when
1366     necessary. The code is crude, but this _is_ just a test program. The
1367     default size has been increased from 32K to 50K.
1368    
1369     2. The code in pcre_study() was using the value of the re argument before
1370     testing it for NULL. (Of course, in any sensible call of the function, it
1371     won't be NULL.)
1372    
1373     3. The memmove() emulation function in pcre_internal.h, which is used on
1374     systems that lack both memmove() and bcopy() - that is, hardly ever -
1375     was missing a "static" storage class specifier.
1376    
1377     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1378     containing an extended class (one that cannot be represented by a bitmap
1379     because it contains high-valued characters or Unicode property items, e.g.
1380     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1381     pattern, but PCRE should not loop if you do not (it no longer does).
1382     [Detail: two cases were found: (a) a repeated subpattern containing an
1383     extended class; (b) a recursive reference to a subpattern that followed a
1384     previous extended class. It wasn't skipping over the extended class
1385     correctly when UTF-8 mode was not set.]
1386    
1387     5. A negated single-character class was not being recognized as fixed-length
1388     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1389     compile error "lookbehind assertion is not fixed length".
1390    
1391     6. The RunPerlTest auxiliary script was showing an unexpected difference
1392     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1393     write a Perl script that can interpret lines of an input file either as
1394     byte characters or as UTF-8, which is what "perltest" was being required to
1395     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1396     can't do is switch easily at run time between having the "use utf8;" pragma
1397     or not. In the end, I fudged it by using the RunPerlTest script to insert
1398     "use utf8;" explicitly for the UTF-8 tests.
1399    
1400     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1401     the end of the subject string, contrary to the documentation and to what
1402     Perl does. This was true of both matching functions. Now it matches only at
1403     the start of the subject and immediately after *internal* newlines.
1404    
1405     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1406     a pointer to an int instead of a pointer to an unsigned long int. This
1407     caused problems on 64-bit systems.
1408    
1409     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1410     instance of the 'standard' template library not being so standard".
1411    
1412     10. There was no check on the number of named subpatterns nor the maximum
1413     length of a subpattern name. The product of these values is used to compute
1414     the size of the memory block for a compiled pattern. By supplying a very
1415     long subpattern name and a large number of named subpatterns, the size
1416     computation could be caused to overflow. This is now prevented by limiting
1417     the length of names to 32 characters, and the number of named subpatterns
1418     to 10,000.
1419    
1420     11. Subpatterns that are repeated with specific counts have to be replicated in
1421     the compiled pattern. The size of memory for this was computed from the
1422     length of the subpattern and the repeat count. The latter is limited to
1423     65535, but there was no limit on the former, meaning that integer overflow
1424     could in principle occur. The compiled length of a repeated subpattern is
1425     now limited to 30,000 bytes in order to prevent this.
1426    
1427     12. Added the optional facility to have named substrings with the same name.
1428    
1429     13. Added the ability to use a named substring as a condition, using the
1430     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1431     are numbers (not recommended). Forward references are permitted.
1432    
1433     14. Added forward references in named backreferences (if you see what I mean).
1434    
1435     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1436     pattern could run off the end of the subject. For example, the pattern
1437     "(?s)(.{1,5})"8 did this with the subject "ab".
1438    
1439     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1440     PCRE_CASELESS was set when matching characters that were quantified with ?
1441     or *.
1442    
1443     17. A character class other than a single negated character that had a minimum
1444     but no maximum quantifier - for example [ab]{6,} - was not handled
1445     correctly by pce_dfa_exec(). It would match only one character.
1446    
1447     18. A valid (though odd) pattern that looked like a POSIX character
1448     class but used an invalid character after [ (for example [[,abc,]]) caused
1449     pcre_compile() to give the error "Failed: internal error: code overflow" or
1450     in some cases to crash with a glibc free() error. This could even happen if
1451     the pattern terminated after [[ but there just happened to be a sequence of
1452     letters, a binary zero, and a closing ] in the memory that followed.
1453    
1454     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1455     over the years. Originally (before any Unicode support), just the bottom 8
1456     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1457     output from "man perlunicode" includes this:
1458    
1459     The regular expression compiler produces polymorphic opcodes. That
1460     is, the pattern adapts to the data and automatically switches to
1461     the Unicode character scheme when presented with Unicode data--or
1462     instead uses a traditional byte scheme when presented with byte
1463     data.
1464    
1465     Sadly, a wide octal escape does not cause a switch, and in a string with
1466     no other multibyte characters, these octal escapes are treated as before.
1467     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1468     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1469     Unicode string.
1470    
1471     I have not perpetrated such confusion in PCRE. Up till now, it took just
1472     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1473     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1474     translate to the appropriate multibyte character.
1475    
1476     29. Applied some refactoring to reduce the number of warnings from Microsoft
1477     and Borland compilers. This has included removing the fudge introduced
1478     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1479     a warning about an unused variable.
1480    
1481     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1482     characters since release 4.0, because Perl (from release 5.004) does not.
1483     [Or at least, is documented not to: some releases seem to be in conflict
1484     with the documentation.] However, when a pattern was studied with
1485     pcre_study() and all its branches started with \s, PCRE still included VT
1486     as a possible starting character. Of course, this did no harm; it just
1487     caused an unnecessary match attempt.
1488    
1489     22. Removed a now-redundant internal flag bit that recorded the fact that case
1490     dependency changed within the pattern. This was once needed for "required
1491     byte" processing, but is no longer used. This recovers a now-scarce options
1492     bit. Also moved the least significant internal flag bit to the most-
1493     significant bit of the word, which was not previously used (hangover from
1494     the days when it was an int rather than a uint) to free up another bit for
1495     the future.
1496    
1497     23. Added support for CRLF line endings as well as CR and LF. As well as the
1498     default being selectable at build time, it can now be changed at runtime
1499     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1500     specify that it is scanning data with non-default line endings.
1501    
1502     24. Changed the definition of CXXLINK to make it agree with the definition of
1503     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1504    
1505     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1506     recursions. This makes a big different to stack usage for some patterns.
1507    
1508     26. If a subpattern containing a named recursion or subroutine reference such
1509     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1510     the space required for the compiled pattern went wrong and gave too small a
1511     value. Depending on the environment, this could lead to "Failed: internal
1512     error: code overflow at offset 49" or "glibc detected double free or
1513     corruption" errors.
1514    
1515     27. Applied patches from Google (a) to support the new newline modes and (b) to
1516     advance over multibyte UTF-8 characters in GlobalReplace.
1517    
1518     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1519     difference for some implementation of PCRE in some Windows version.
1520    
1521     29. Added some extra testing facilities to pcretest:
1522    
1523     \q<number> in a data line sets the "match limit" value
1524     \Q<number> in a data line sets the "match recursion limt" value
1525     -S <number> sets the stack size, where <number> is in megabytes
1526    
1527     The -S option isn't available for Windows.
1528    
1529    
1530 nigel 89 Version 6.6 06-Feb-06
1531     ---------------------
1532    
1533     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1534     in pcreposix.h. I have copied the definition from pcre.h.
1535    
1536     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1537     because pcre.h is no longer a built file.
1538    
1539     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1540     not normally included in the compiled code.
1541    
1542    
1543 nigel 87 Version 6.5 01-Feb-06
1544     ---------------------
1545    
1546     1. When using the partial match feature with pcre_dfa_exec(), it was not
1547     anchoring the second and subsequent partial matches at the new starting
1548     point. This could lead to incorrect results. For example, with the pattern
1549     /1234/, partially matching against "123" and then "a4" gave a match.
1550    
1551     2. Changes to pcregrep:
1552    
1553     (a) All non-match returns from pcre_exec() were being treated as failures
1554     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1555     error message is output. Some extra information is given for the
1556     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1557     probably the only errors that are likely to be caused by users (by
1558     specifying a regex that has nested indefinite repeats, for instance).
1559     If there are more than 20 of these errors, pcregrep is abandoned.
1560    
1561     (b) A binary zero was treated as data while matching, but terminated the
1562     output line if it was written out. This has been fixed: binary zeroes
1563     are now no different to any other data bytes.
1564    
1565     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1566     used to set a locale for matching. The --locale=xxxx long option has
1567     been added (no short equivalent) to specify a locale explicitly on the
1568     pcregrep command, overriding the environment variables.
1569    
1570     (d) When -B was used with -n, some line numbers in the output were one less
1571     than they should have been.
1572    
1573     (e) Added the -o (--only-matching) option.
1574    
1575     (f) If -A or -C was used with -c (count only), some lines of context were
1576     accidentally printed for the final match.
1577    
1578     (g) Added the -H (--with-filename) option.
1579    
1580     (h) The combination of options -rh failed to suppress file names for files
1581     that were found from directory arguments.
1582    
1583     (i) Added the -D (--devices) and -d (--directories) options.
1584    
1585     (j) Added the -F (--fixed-strings) option.
1586    
1587     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1588    
1589     (l) Added the --colo(u)r option.
1590    
1591     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1592     is not present by default.
1593    
1594     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1595     items such as (?R) or (?1), when the recursion could match a number of
1596     alternatives. If it matched one of the alternatives, but subsequently,
1597     outside the recursion, there was a failure, the code tried to back up into
1598     the recursion. However, because of the way PCRE is implemented, this is not
1599     possible, and the result was an incorrect result from the match.
1600    
1601     In order to prevent this happening, the specification of recursion has
1602     been changed so that all such subpatterns are automatically treated as
1603     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1604    
1605     4. I had overlooked the fact that, in some locales, there are characters for
1606     which isalpha() is true but neither isupper() nor islower() are true. In
1607     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1608     and ordfeminine) are like this. This affected the treatment of \w and \W
1609     when they appeared in character classes, but not when they appeared outside
1610     a character class. The bit map for "word" characters is now created
1611     separately from the results of isalnum() instead of just taking it from the
1612     upper, lower, and digit maps. (Plus the underscore character, of course.)
1613    
1614     5. The above bug also affected the handling of POSIX character classes such as
1615     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1616     permanent tables. Instead, the bit maps for such a class were previously
1617     created as the appropriate unions of the upper, lower, and digit bitmaps.
1618     Now they are created by subtraction from the [[:word:]] class, which has
1619     its own bitmap.
1620    
1621     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1622     It is created by subtracting the vertical space characters (\x09, \x0a,
1623     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1624     subtraction was done in the overall bitmap for a character class, meaning
1625     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1626     be recognized. This bug has been fixed.
1627    
1628     7. Patches from the folks at Google:
1629    
1630     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1631     real life, but is still worth protecting against".
1632    
1633     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1634     regular expressions".
1635    
1636     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1637     have it.
1638    
1639     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1640     "configure" and the latter not, in order to fix a problem somebody had
1641     with compiling the Arg class on HP-UX.
1642    
1643     (e) Improve the error-handling of the C++ wrapper a little bit.
1644    
1645     (f) New tests for checking recursion limiting.
1646    
1647     8. The pcre_memmove() function, which is used only if the environment does not
1648     have a standard memmove() function (and is therefore rarely compiled),
1649     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1650     returning a result (though PCRE never actually uses the result).
1651    
1652     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1653     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1654     returned instead of calling malloc() with an overflowing number that would
1655     most likely cause subsequent chaos.
1656    
1657     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1658    
1659     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1660     with this option is matched, the nmatch and pmatch options of regexec() are
1661     ignored.
1662    
1663     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1664     provided in case anyone wants to the the POSIX interface with UTF-8
1665     strings.
1666    
1667     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1668     C++ linking (needed for some HP-UX environments).
1669    
1670     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1671     (unused parameter) and in the pcre_printint() function (omitted "default"
1672     switch label when the default is to do nothing).
1673    
1674     15. Added some code to make it possible, when PCRE is compiled as a C++
1675     library, to replace subject pointers for pcre_exec() with a smart pointer
1676     class, thus making it possible to process discontinuous strings.
1677    
1678     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1679     much the same function. They were added by different people who were trying
1680     to make PCRE easy to compile on non-Unix systems. It has been suggested
1681     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1682     for compiling on Windows systems. I have therefore replaced it with
1683     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1684     defaults to "extern" for C or "extern C" for C++, which works fine on
1685     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1686     SCOPE with something explicit in config.h. In addition:
1687    
1688     (a) pcreposix.h still had just "extern" instead of either of these macros;
1689     I have replaced it with PCRE_DATA_SCOPE.
1690    
1691     (b) Functions such as _pcre_xclass(), which are internal to the library,
1692     but external in the C sense, all had PCRE_EXPORT in their definitions.
1693     This is apparently wrong for the Windows case, so I have removed it.
1694     (It makes no difference on Unix-like systems.)
1695    
1696     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1697     of recursive calls to match(). This is different to MATCH_LIMIT because
1698     that limits the total number of calls to match(), not all of which increase
1699     the depth of recursion. Limiting the recursion depth limits the amount of
1700     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1701     when PCRE is compiled, and changed at run time. A patch from Google adds
1702     this functionality to the C++ interface.
1703    
1704     18. Changes to the handling of Unicode character properties:
1705    
1706     (a) Updated the table to Unicode 4.1.0.
1707    
1708     (b) Recognize characters that are not in the table as "Cn" (undefined).
1709    
1710     (c) I revised the way the table is implemented to a much improved format
1711     which includes recognition of ranges. It now supports the ranges that
1712     are defined in UnicodeData.txt, and it also amalgamates other
1713     characters into ranges. This has reduced the number of entries in the
1714     table from around 16,000 to around 3,000, thus reducing its size
1715     considerably. I realized I did not need to use a tree structure after
1716     all - a binary chop search is just as efficient. Having reduced the
1717     number of entries, I extended their size from 6 bytes to 8 bytes to
1718     allow for more data.
1719    
1720     (d) Added support for Unicode script names via properties such as \p{Han}.
1721    
1722     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1723     matching that character.
1724    
1725     20. When matching a repeated Unicode property with a minimum greater than zero,
1726     (for example \pL{2,}), PCRE could look past the end of the subject if it
1727     reached it while seeking the minimum number of characters. This could
1728     happen only if some of the characters were more than one byte long, because
1729     there is a check for at least the minimum number of bytes.
1730    
1731     21. Refactored the implementation of \p and \P so as to be more general, to
1732     allow for more different types of property in future. This has changed the
1733     compiled form incompatibly. Anybody with saved compiled patterns that use
1734     \p or \P will have to recompile them.
1735    
1736     22. Added "Any" and "L&" to the supported property types.
1737    
1738     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1739     but give a compile time error if the value is greater than 0xff.
1740    
1741     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1742     accidentally not being installed or uninstalled.
1743    
1744     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1745     made were to insert the current release number. This seemed silly, because
1746     it made things harder for people building PCRE on systems that don't run
1747     "configure". I have turned pcre.h into a distributed file, no longer built
1748     by "configure", with the version identification directly included. There is
1749     no longer a pcre.h.in file.
1750    
1751     However, this change necessitated a change to the pcre-config script as
1752     well. It is built from pcre-config.in, and one of the substitutions was the
1753     release number. I have updated configure.ac so that ./configure now finds
1754     the release number by grepping pcre.h.
1755    
1756     26. Added the ability to run the tests under valgrind.
1757    
1758    
1759 nigel 85 Version 6.4 05-Sep-05
1760     ---------------------
1761    
1762     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1763     "--" to be printed when multiple files were scanned, even when none of the
1764     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1765     consider it to be a bug, and have restored the previous behaviour.
1766    
1767     2. A couple of code tidies to get rid of compiler warnings.
1768    
1769     3. The pcretest program used to cheat by referring to symbols in the library
1770     whose names begin with _pcre_. These are internal symbols that are not
1771     really supposed to be visible externally, and in some environments it is
1772     possible to suppress them. The cheating is now confined to including
1773     certain files from the library's source, which is a bit cleaner.
1774    
1775     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1776     file's purpose clearer.
1777    
1778     5. Reorganized pcre_ucp_findchar().
1779    
1780    
1781 nigel 83 Version 6.3 15-Aug-05
1782     ---------------------
1783    
1784     1. The file libpcre.pc.in did not have general read permission in the tarball.
1785    
1786     2. There were some problems when building without C++ support:
1787    
1788     (a) If C++ support was not built, "make install" and "make test" still
1789     tried to test it.
1790    
1791     (b) There were problems when the value of CXX was explicitly set. Some
1792     changes have been made to try to fix these, and ...
1793    
1794     (c) --disable-cpp can now be used to explicitly disable C++ support.
1795    
1796     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1797     backslash in a target when C++ was disabled. This confuses some
1798     versions of "make", apparently. Using an intermediate variable solves
1799     this. (Same for CPP_LOBJ.)
1800    
1801     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1802     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1803     necessary on certain architectures.
1804    
1805     4. Added a setting of -export-symbols-regex to the link command to remove
1806     those symbols that are exported in the C sense, but actually are local
1807     within the library, and not documented. Their names all begin with
1808     "_pcre_". This is not a perfect job, because (a) we have to except some
1809     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1810     available (and never for static libraries). I have made a note to try to
1811     find a way round (a) in the future.
1812    
1813    
1814 nigel 81 Version 6.2 01-Aug-05
1815     ---------------------
1816    
1817     1. There was no test for integer overflow of quantifier values. A construction
1818     such as {1111111111111111} would give undefined results. What is worse, if
1819     a minimum quantifier for a parenthesized subpattern overflowed and became
1820     negative, the calculation of the memory size went wrong. This could have
1821     led to memory overwriting.
1822    
1823     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1824    
1825     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1826     operating environments where this matters.
1827    
1828     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1829     PCRE options from within the C++ wrapper.
1830    
1831     5. Named capturing subpatterns were not being correctly counted when a pattern
1832     was compiled. This caused two problems: (a) If there were more than 100
1833     such subpatterns, the calculation of the memory needed for the whole
1834     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1835     back references of the form \12, where the number was greater than 9, were
1836     not recognized as back references, even though there were sufficient
1837     previous subpatterns.
1838    
1839     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1840     versions of gcc, e.g. 2.95.4.
1841    
1842    
1843 nigel 79 Version 6.1 21-Jun-05
1844     ---------------------
1845    
1846     1. There was one reference to the variable "posix" in pcretest.c that was not
1847     surrounded by "#if !defined NOPOSIX".
1848    
1849     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1850     the cross-check on the old pcre_info() function, for the benefit of the
1851     cut-down version of PCRE that is currently imported into Exim.
1852    
1853     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1854     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1855     patterns that start (?i) but I don't think that matters. The use of (?i) is
1856     just an example; this all applies to the other options as well.
1857    
1858     4. Since libtool seems to echo the compile commands it is issuing, the output
1859     from "make" can be reduced a bit by putting "@" in front of each libtool
1860     compile command.
1861    
1862     5. Patch from the folks at Google for configure.in to be a bit more thorough
1863     in checking for a suitable C++ installation before trying to compile the
1864     C++ stuff. This should fix a reported problem when a compiler was present,
1865     but no suitable headers.
1866    
1867     6. The man pages all had just "PCRE" as their title. I have changed them to
1868     be the relevant file name. I have also arranged that these names are
1869     retained in the file doc/pcre.txt, which is a concatenation in text format
1870     of all the man pages except the little individual ones for each function.
1871    
1872     7. The NON-UNIX-USE file had not been updated for the different set of source
1873     files that come with release 6. I also added a few comments about the C++
1874     wrapper.
1875    
1876    
1877 nigel 77 Version 6.0 07-Jun-05
1878     ---------------------
1879    
1880     1. Some minor internal re-organization to help with my DFA experiments.
1881    
1882     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1883     didn't matter for the library itself when fully configured, but did matter
1884     when compiling without UCP support, or within Exim, where the ucp files are
1885     not imported.
1886    
1887     3. Refactoring of the library code to split up the various functions into
1888     different source modules. The addition of the new DFA matching code (see
1889     below) to a single monolithic source would have made it really too
1890     unwieldy, quite apart from causing all the code to be include in a
1891     statically linked application, when only some functions are used. This is
1892     relevant even without the DFA addition now that patterns can be compiled in
1893     one application and matched in another.
1894    
1895     The downside of splitting up is that there have to be some external
1896     functions and data tables that are used internally in different modules of
1897     the library but which are not part of the API. These have all had their
1898     names changed to start with "_pcre_" so that they are unlikely to clash
1899     with other external names.
1900    
1901     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1902     a different (DFA) algorithm. Although it is slower than the original
1903     function, it does have some advantages for certain types of matching
1904     problem.
1905    
1906     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1907     including restarting after a partial match.
1908    
1909     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1910     defined when compiling for Windows was sent to me. I have put it into the
1911     code, though I have no means of testing or verifying it.
1912    
1913     7. Added the pcre_refcount() auxiliary function.
1914    
1915     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1916     match before or at the first newline in the subject string. In pcretest,
1917     the /f option on a pattern can be used to set this.
1918    
1919     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1920     would behave wrongly. This has been present in PCRE since release 4.0.
1921    
1922     10. A number of changes to the pcregrep command:
1923    
1924     (a) Refactored how -x works; insert ^(...)$ instead of setting
1925     PCRE_ANCHORED and checking the length, in preparation for adding
1926     something similar for -w.
1927    
1928     (b) Added the -w (match as a word) option.
1929    
1930     (c) Refactored the way lines are read and buffered so as to have more
1931     than one at a time available.
1932    
1933     (d) Implemented a pcregrep test script.
1934    
1935     (e) Added the -M (multiline match) option. This allows patterns to match
1936     over several lines of the subject. The buffering ensures that at least
1937     8K, or the rest of the document (whichever is the shorter) is available
1938     for matching (and similarly the previous 8K for lookbehind assertions).
1939    
1940     (f) Changed the --help output so that it now says
1941    
1942     -w, --word-regex(p)
1943    
1944     instead of two lines, one with "regex" and the other with "regexp"
1945     because that confused at least one person since the short forms are the
1946     same. (This required a bit of code, as the output is generated
1947     automatically from a table. It wasn't just a text change.)
1948    
1949     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1950     option but starts with a hyphen. Could be a pattern or a path name
1951     starting with a hyphen, for instance.
1952    
1953     (h) "-" can be given as a file name to represent stdin.
1954    
1955     (i) When file names are being printed, "(standard input)" is used for
1956     the standard input, for compatibility with GNU grep. Previously
1957     "<stdin>" was used.
1958    
1959     (j) The option --label=xxx can be used to supply a name to be used for
1960     stdin when file names are being printed. There is no short form.
1961    
1962     (k) Re-factored the options decoding logic because we are going to add
1963     two more options that take data. Such options can now be given in four
1964     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1965    
1966     (l) Added the -A, -B, and -C options for requesting that lines of context
1967     around matches be printed.
1968    
1969     (m) Added the -L option to print the names of files that do not contain
1970     any matching lines, that is, the complement of -l.
1971    
1972     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1973     continue to scan other files.
1974    
1975     (o) The -s option was incorrectly implemented. For compatibility with other
1976     greps, it now suppresses the error message for a non-existent or non-
1977     accessible file (but not the return code). There is a new option called
1978     -q that suppresses the output of matching lines, which was what -s was
1979     previously doing.
1980    
1981     (p) Added --include and --exclude options to specify files for inclusion
1982     and exclusion when recursing.
1983    
1984     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1985     Hopefully, it now does.
1986    
1987     12. Missing cast in pcre_study().
1988    
1989     13. Added an "uninstall" target to the makefile.
1990    
1991     14. Replaced "extern" in the function prototypes in Makefile.in with
1992     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1993     world, but is set differently for Windows.
1994    
1995     15. Added a second compiling function called pcre_compile2(). The only
1996     difference is that it has an extra argument, which is a pointer to an
1997     integer error code. When there is a compile-time failure, this is set
1998     non-zero, in addition to the error test pointer being set to point to an
1999     error message. The new argument may be NULL if no error number is required
2000     (but then you may as well call pcre_compile(), which is now just a
2001     wrapper). This facility is provided because some applications need a
2002     numeric error indication, but it has also enabled me to tidy up the way
2003     compile-time errors are handled in the POSIX wrapper.
2004    
2005     16. Added VPATH=.libs to the makefile; this should help when building with one
2006     prefix path and installing with another. (Or so I'm told by someone who
2007     knows more about this stuff than I do.)
2008    
2009     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2010     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2011     match everything, including newlines. This is not POSIX-compatible, but
2012     somebody wanted the feature. From pcretest it can be activated by using
2013     both the P and the s flags.
2014    
2015     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2016    
2017     19. libpcre.pc was being incorrectly installed as executable.
2018    
2019     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2020     it now also looks for '\r' so that it will work unmodified on Windows.
2021    
2022     21. Added Google's contributed C++ wrapper to the distribution.
2023    
2024     22. Added some untidy missing memory free() calls in pcretest, to keep
2025     Electric Fence happy when testing.
2026    
2027    
2028    
2029 nigel 75 Version 5.0 13-Sep-04
2030     ---------------------
2031    
2032     1. Internal change: literal characters are no longer packed up into items
2033     containing multiple characters in a single byte-string. Each character
2034     is now matched using a separate opcode. However, there may be more than one
2035     byte in the character in UTF-8 mode.
2036    
2037     2. The pcre_callout_block structure has two new fields: pattern_position and
2038     next_item_length. These contain the offset in the pattern to the next match
2039     item, and its length, respectively.
2040    
2041     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2042     insertion of callouts before each pattern item. Added the /C option to
2043     pcretest to make use of this.
2044    
2045     4. On the advice of a Windows user, the lines
2046    
2047     #if defined(_WIN32) || defined(WIN32)
2048     _setmode( _fileno( stdout ), 0x8000 );
2049     #endif /* defined(_WIN32) || defined(WIN32) */
2050    
2051     have been added to the source of pcretest. This apparently does useful
2052     magic in relation to line terminators.
2053    
2054     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2055     for the benefit of those environments where the "b" makes a difference.
2056    
2057     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2058     to know about it. I have put a hack into configure.in that adds in code
2059     to set GCC=yes if CC=icc. This seems to end up at a point in the
2060     generated configure script that is early enough to affect the setting of
2061     compiler options, which is what is needed, but I have no means of testing
2062     whether it really works. (The user who reported this had patched the
2063     generated configure script, which of course I cannot do.)
2064    
2065     LATER: After change 22 below (new libtool files), the configure script
2066     seems to know about icc (and also ecc). Therefore, I have commented out
2067     this hack in configure.in.
2068    
2069     7. Added support for pkg-config (2 patches were sent in).
2070    
2071     8. Negated POSIX character classes that used a combination of internal tables
2072     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2073     [[:^ascii]]. Typically, they would match almost any characters. The other
2074     POSIX classes were not broken in this way.
2075    
2076     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2077     to find the match, as PCRE was deluded into thinking that the match had to
2078     start at the start point or following a newline. The same bug applied to
2079     patterns with negative forward assertions or any backward assertions
2080     preceding ".*" at the start, unless the pattern required a fixed first
2081     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2082    
2083     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2084     starting at the last subject character, bytes beyond the end of the subject
2085     string were read.
2086    
2087     11. Renamed the variable "class" as "classbits" to make life easier for C++
2088     users. (Previously there was a macro definition, but it apparently wasn't
2089     enough.)
2090    
2091     12. Added the new field "tables" to the extra data so that tables can be passed
2092     in at exec time, or the internal tables can be re-selected. This allows
2093     a compiled regex to be saved and re-used at a later time by a different
2094     program that might have everything at different addresses.
2095    
2096     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2097     -R library as well as a -L library.
2098    
2099     14. The debugging options of pcretest (-d on the command line or D on a
2100     pattern) showed incorrect output for anything following an extended class
2101     that contained multibyte characters and which was followed by a quantifier.
2102    
2103     15. Added optional support for general category Unicode character properties
2104     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2105     support. It adds about 90K to the size of the library. The meanings of the
2106     inbuilt class escapes such as \d and \s have NOT been changed.
2107    
2108     16. Updated pcredemo.c to include calls to free() to release the memory for the
2109     compiled pattern.
2110    
2111     17. The generated file chartables.c was being created in the source directory
2112     instead of in the building directory. This caused the build to fail if the
2113     source directory was different from the building directory, and was
2114     read-only.
2115    
2116     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2117     file. No doubt somebody will tell me if they don't make sense... Also added
2118     Dan Mooney's comments about building on OpenVMS.
2119    
2120     19. Added support for partial matching via the PCRE_PARTIAL option for
2121     pcre_exec() and the \P data escape in pcretest.
2122    
2123     20. Extended pcretest with 3 new pattern features:
2124    
2125     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2126     write the compiled pattern to the file whose name is "rest-of-line".
2127     This is a straight binary dump of the data, with the saved pointer to
2128     the character tables forced to be NULL. The study data, if any, is
2129     written too. After writing, pcretest reads a new pattern.
2130    
2131     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2132     compiled pattern from the given file. There must not be any
2133     occurrences of "<" in the file name (pretty unlikely); if there are,
2134     pcretest will instead treat the initial "<" as a pattern delimiter.
2135     After reading in the pattern, pcretest goes on to read data lines as
2136     usual.
2137    
2138     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2139     and 16-bit fields in a compiled pattern, to simulate a pattern that
2140     was compiled on a host of opposite endianness.
2141    
2142     21. The pcre-exec() function can now cope with patterns that were compiled on
2143     hosts of opposite endianness, with this restriction:
2144    
2145     As for any compiled expression that is saved and used later, the tables
2146     pointer field cannot be preserved; the extra_data field in the arguments
2147     to pcre_exec() should be used to pass in a tables address if a value
2148     other than the default internal tables were used at compile time.
2149    
2150     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2151     now diagnosed as an error. Previously, most of the time, a negative number
2152     would have been treated as zero, but if in addition "ovector" was passed as
2153     NULL, a crash could occur.
2154    
2155     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2156     new versions from the libtool 1.5 distribution (the last one is a copy of
2157     a file called libtool.m4). This seems to have fixed the need to patch
2158     "configure" to support Darwin 1.3 (which I used to do). However, I still
2159     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2160     workstation).
2161    
2162     24. Changed the PCRE licence to be the more standard "BSD" licence.
2163    
2164    
2165 nigel 73 Version 4.5 01-Dec-03
2166     ---------------------
2167    
2168     1. There has been some re-arrangement of the code for the match() function so
2169     that it can be compiled in a version that does not call itself recursively.
2170     Instead, it keeps those local variables that need separate instances for
2171     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2172     needs to "recurse". Keeping track of where control must go is done by means
2173     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2174     hide most of the details from the main code, and operates only if
2175     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2176     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2177     operating.
2178    
2179     To make it easier for callers to provide specially tailored get/free
2180     functions for this usage, two new functions, pcre_stack_malloc, and
2181     pcre_stack_free, are used. They are always called in strict stacking order,
2182     and the size of block requested is always the same.
2183    
2184     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2185     PCRE has been compiled to use the stack or the heap for recursion. The
2186     -C option of pcretest uses this to show which version is compiled.
2187    
2188     A new data escape \S, is added to pcretest; it causes the amounts of store
2189     obtained and freed by both kinds of malloc/free at match time to be added
2190     to the output.
2191    
2192     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2193     what's available on my current Linux desktop machine.
2194    
2195     3. When matching a UTF-8 string, the test for a valid string at the start has
2196     been extended. If start_offset is not zero, PCRE now checks that it points
2197     to a byte that is the start of a UTF-8 character. If not, it returns
2198     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2199     this is necessary because there may be backward assertions in the pattern.
2200     When matching the same subject several times, it may save resources to use
2201     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2202    
2203     4. The code for checking the validity of UTF-8 strings has been tightened so
2204     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2205     containing "overlong sequences".
2206    
2207     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2208     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2209     should have been "&", but it just so happened that all the cases this let
2210     through by mistake were picked up later in the function.
2211    
2212     6. I had used a variable called "isblank" - this is a C99 function, causing
2213     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2214    
2215     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2216     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2217     so the version is shown; (c) stop "make test" echoing "./RunTest".
2218    
2219     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2220    
2221     9. The prototype for memmove() for systems that don't have it was using
2222     size_t, but the inclusion of the header that defines size_t was later. I've
2223     moved the #includes for the C headers earlier to avoid this.
2224    
2225     10. Added some adjustments to the code to make it easier to compiler on certain
2226     special systems:
2227    
2228     (a) Some "const" qualifiers were missing.
2229     (b) Added the macro EXPORT before all exported functions; by default this
2230     is defined to be empty.
2231     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2232     that it reads its output file name as an argument instead of writing
2233     to the standard output and assuming this can be redirected.
2234    
2235     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2236     class containing characters with values greater than 255, PCRE compilation
2237     went into a loop.
2238    
2239     12. A recursive reference to a subpattern that was within another subpattern
2240     that had a minimum quantifier of zero caused PCRE to crash. For example,
2241     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2242     recursion. If the recursively-called subpattern itself had a zero repeat,
2243     that was OK.
2244    
2245     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2246     buffer into which it was copied (for escape processing) was still set at
2247     1024, so long lines caused crashes.
2248    
2249     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2250     "internal error: code overflow...". This applied to any character class
2251     that was followed by a possessive quantifier.
2252    
2253     15. Modified the Makefile to add libpcre.la as a prerequisite for
2254     libpcreposix.la because I was told this is needed for a parallel build to
2255     work.
2256    
2257     16. If a pattern that contained .* following optional items at the start was
2258     studied, the wrong optimizing data was generated, leading to matching
2259     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2260     matching string must start with a or b or c. The correct conclusion for
2261     this pattern is that a match can start with any character.
2262    
2263    
2264 nigel 71 Version 4.4 13-Aug-03
2265     ---------------------
2266    
2267     1. In UTF-8 mode, a character class containing characters with values between
2268     127 and 255 was not handled correctly if the compiled pattern was studied.
2269     In fixing this, I have also improved the studying algorithm for such
2270     classes (slightly).
2271    
2272     2. Three internal functions had redundant arguments passed to them. Removal
2273     might give a very teeny performance improvement.
2274    
2275     3. Documentation bug: the value of the capture_top field in a callout is *one
2276     more than* the number of the hightest numbered captured substring.
2277    
2278     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2279     in incorrectly linking with a previously installed version. They now link
2280     explicitly with libpcre.la.
2281    
2282     5. configure.in no longer needs to recognize Cygwin specially.
2283    
2284     6. A problem in pcre.in for Windows platforms is fixed.
2285    
2286     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2287     pcretest, it used to include the size of the study block as part of its
2288     output. Unfortunately, the structure contains a field that has a different
2289     size on different hardware architectures. This meant that the tests that
2290     showed this size failed. As the block is currently always of a fixed size,
2291     this information isn't actually particularly useful in pcretest output, so
2292     I have just removed it.
2293    
2294     8. Three pre-processor statements accidentally did not start in column 1.
2295     Sadly, there are *still* compilers around that complain, even though
2296     standard C has not required this for well over a decade. Sigh.
2297    
2298     9. In pcretest, the code for checking callouts passed small integers in the
2299     callout_data field, which is a void * field. However, some picky compilers
2300     complained about the casts involved for this on 64-bit systems. Now
2301     pcretest passes the address of the small integer instead, which should get
2302     rid of the warnings.
2303    
2304     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2305     both compile and run time, and gives an error if an invalid UTF-8 sequence
2306     is found. There is a option for disabling this check in cases where the
2307     string is known to be correct and/or the maximum performance is wanted.
2308    
2309     11. In response to a bug report, I changed one line in Makefile.in from
2310    
2311     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2312     to
2313     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2314    
2315     to look similar to other lines, but I have no way of telling whether this
2316     is the right thing to do, as I do not use Windows. No doubt I'll get told
2317     if it's wrong...
2318    
2319    
2320 nigel 69 Version 4.3 21-May-03
2321     ---------------------
2322    
2323     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2324     Makefile.
2325    
2326     2. Some refactoring to improve the quality of the code:
2327    
2328     (i) The utf8_table... variables are now declared "const".
2329    
2330     (ii) The code for \cx, which used the "case flipping" table to upper case
2331     lower case letters, now just substracts 32. This is ASCII-specific,
2332     but the whole concept of \cx is ASCII-specific, so it seems
2333     reasonable.
2334    
2335     (iii) PCRE was using its character types table to recognize decimal and
2336     hexadecimal digits in the pattern. This is silly, because it handles
2337     only 0-9, a-f, and A-F, but the character types table is locale-
2338     specific, which means strange things might happen. A private
2339     table is now used for this - though it costs 256 bytes, a table is
2340     much faster than multiple explicit tests. Of course, the standard
2341     character types table is still used for matching digits in subject
2342     strings against \d.
2343    
2344     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2345     ending in _t are). So I've renamed it as ESC_tee.
2346    
2347     3. The first argument for regexec() in the POSIX wrapper should have been
2348     defined as "const".
2349    
2350     4. Changed pcretest to use malloc() for its buffers so that they can be
2351     Electric Fenced for debugging.
2352    
2353     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2354     to read one or more bytes before the start of the subject string. Often this
2355     had no effect on PCRE's behaviour, but in some circumstances it could
2356     provoke a segmentation fault.
2357    
2358     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2359     to try to read one or more bytes before the start of the subject string.
2360    
2361     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2362     UTF-8 support could misbehave in various ways if the subject string
2363     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2364     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2365     back over UTF-8 characters.)
2366    
2367    
2368 nigel 67 Version 4.2 14-Apr-03
2369     ---------------------
2370    
2371     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2372    
2373     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2374     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2375     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2376     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2377     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2378     and BUILD_EXEEXT
2379     Note: automatic setting of the BUILD variables is not yet working
2380     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2381     compile-time but not at link-time
2382     [LINK]: use for linking executables only
2383     make different versions for Windows and non-Windows
2384     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2385     libraries
2386     [LINK_FOR_BUILD]: new variable
2387     [OBJEXT]: use throughout
2388     [EXEEXT]: use throughout
2389     <winshared>: new target
2390     <wininstall>: new target
2391     <dftables.o>: use native compiler
2392     <dftables>: use native linker
2393     <install>: handle Windows platform correctly
2394     <clean>: ditto
2395     <check>: ditto
2396     copy DLL to top builddir before testing
2397    
2398     As part of these changes, -no-undefined was removed again. This was reported
2399     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2400     in any case.
2401    
2402     3. Some tidies to get rid of compiler warnings:
2403    
2404     . In the match_data structure, match_limit was an unsigned long int, whereas
2405     match_call_count was an int. I've made them both unsigned long ints.
2406    
2407     . In pcretest the fact that a const uschar * doesn't automatically cast to
2408     a void * provoked a warning.
2409    
2410     . Turning on some more compiler warnings threw up some "shadow" variables
2411     and a few more missing casts.
2412    
2413     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2414     option, a class that contained a single character with a value between 128
2415     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2416    
2417     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2418     option, a class that contained several characters, but with at least one
2419     whose value was between 128 and 255 caused PCRE to crash.
2420    
2421    
2422 nigel 65 Version 4.1 12-Mar-03
2423     ---------------------
2424 nigel 63
2425 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2426     needed, and a string in dftables.c that was longer than standard compilers are
2427     required to support.
2428    
2429     2. Compiling with Sun's compiler found a few more places where the code could
2430     be tidied up in order to avoid warnings.
2431    
2432     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2433     first of these names is deprecated in the latest Autoconf in favour of the name
2434     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2435     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2436     analogy I have changed it to CFLAGS_FOR_BUILD.
2437    
2438     4. Added -no-undefined to the linking command in the Makefile, because this is
2439     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2440     linking step for the pcreposix library.
2441    
2442     5. PCRE was failing to diagnose the case of two named groups with the same
2443     name.
2444    
2445     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2446     literal character that is needed in the subject for a match, and scans along to
2447     ensure that it is present before embarking on the full matching process. This
2448     saves time in cases of nested unlimited repeats that are never going to match.
2449     Problem: the scan can take a lot of time if the subject is very long (e.g.
2450     megabytes), thus penalizing straightforward matches. It is now done only if the
2451     amount of subject to be scanned is less than 1000 bytes.
2452    
2453     7. A lesser problem with the same optimization is that it was recording the
2454     first character of an anchored pattern as "needed", thus provoking a search
2455     right along the subject, even when the first match of the pattern was going to
2456     fail. The "needed" character is now not set for anchored patterns, unless it
2457     follows something in the pattern that is of non-fixed length. Thus, it still
2458     fulfils its original purpose of finding quick non-matches in cases of nested
2459     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2460    
2461    
2462     Version 4.0 17-Feb-03
2463     ---------------------
2464    
2465 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2466     extended to the end of string, PCRE compiled incorrect data. This could lead to
2467     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2468    
2469     2. Moved to autoconf 2.53 and libtool 1.4.2.
2470    
2471     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2472     the special perltest8 script is no longer needed - all the tests can be run
2473     from a single perltest script.
2474    
2475     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2476     by \s. It has now been removed in PCRE. This means it isn't recognized as
2477     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2478     class [:space:] *does* include VT, thereby creating a mess.
2479    
2480     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2481     space and tab.
2482    
2483     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2484     its new features into the main test script, reducing the number of scripts.
2485    
2486     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2487     were backward compatible, and made the (?i) apply to the whole pattern, as if
2488     /i were given. Now it behaves more logically, and applies the option setting
2489     only to what follows. PCRE has been changed to follow suit. However, if it
2490     finds options settings right at the start of the pattern, it extracts them into
2491     the global options, as before. Thus, they show up in the info data.
2492    
2493     8. Added support for the \Q...\E escape sequence. Characters in between are
2494     treated as literals. This is slightly different from Perl in that $ and @ are
2495     also handled as literals inside the quotes. In Perl, they will cause variable
2496     interpolation. Note the following examples:
2497    
2498     Pattern PCRE matches Perl matches
2499    
2500     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2501     \Qabc\$xyz\E abc\$xyz abc\$xyz
2502     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2503    
2504     For compatibility with Perl, \Q...\E sequences are recognized inside character
2505     classes as well as outside them.
2506    
2507     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2508     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2509     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2510     signed/unsigned warnings.
2511    
2512     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2513     option for pcretest, so I've replaced it by a simple function that does just
2514     that job.
2515    
2516     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2517     "pcregrep -".
2518    
2519     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2520     Java package. This provides some syntactic sugar for simple cases of what my
2521     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2522     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2523     item, you can use this simplified notation. Note that only makes sense with
2524     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2525     greediness, whatever the setting of the PCRE_UNGREEDY option.
2526    
2527     13. A change of greediness default within a pattern was not taking effect at
2528     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2529     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2530     was abstracted outside.
2531    
2532     14. PCRE now supports the \G assertion. It is true when the current matching
2533     position is at the start point of the match. This differs from \A when the
2534     starting offset is non-zero. Used with the /g option of pcretest (or similar
2535     code), it works in the same way as it does for Perl's /g option. If all
2536     alternatives of a regex begin with \G, the expression is anchored to the start
2537     match position, and the "anchored" flag is set in the compiled expression.
2538    
2539     15. Some bugs concerning the handling of certain option changes within patterns
2540     have been fixed. These applied to options other than (?ims). For example,
2541     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2542     been the other way round. Some of this was related to change 7 above.
2543    
2544     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2545     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2546     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2547     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2548    
2549     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2550     mode. Unlike ".", it always matches newline, whatever the setting of
2551     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2552     assertions. Perl allows it, but it doesn't (in general) work because it can't
2553     calculate the length of the lookbehind. At least, that's the case for Perl
2554     5.8.0 - I've been told they are going to document that it doesn't work in
2555     future.
2556    
2557     18. Added an error diagnosis for escapes that PCRE does not support: these are
2558     \L, \l, \N, \P, \p, \U, \u, and \X.
2559    
2560     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2561     reading past the end of the pattern in cases such as /[abcd/.
2562    
2563     20. PCRE was getting more memory than necessary for patterns with classes that
2564     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2565    
2566     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2567     compiling PCRE for use with Virtual Pascal.
2568    
2569     22. Small fix to the Makefile to make it work properly if the build is done
2570     outside the source tree.
2571    
2572     23. Added a new extension: a condition to go with recursion. If a conditional
2573     subpattern starts with (?(R) the "true" branch is used if recursion has
2574     happened, whereas the "false" branch is used only at the top level.
2575    
2576     24. When there was a very long string of literal characters (over 255 bytes
2577     without UTF support, over 250 bytes with UTF support), the computation of how
2578     much memory was required could be incorrect, leading to segfaults or other
2579     strange effects.
2580    
2581     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2582     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2583     there was a subsequent back reference to those brackets. This meant that, for
2584     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2585     possible to check for precisely this case. All we can do is abandon the
2586     optimization if .* occurs inside capturing brackets when there are any back
2587     references whatsoever. (See below for a better fix that came later.)
2588    
2589     26. The handling of the optimization for finding the first character of a
2590     non-anchored pattern, and for finding a character that is required later in the
2591     match were failing in some cases. This didn't break the matching; it just
2592     failed to optimize when it could. The way this is done has been re-implemented.
2593    
2594     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2595    
2596     28. Added a new feature that provides some of the functionality that Perl
2597     provides with (?{...}). The facility is termed a "callout". The way it is done
2598     in PCRE is for the caller to provide an optional function, by setting
2599     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2600     global variable. By default it is unset, which disables all calling out. To get
2601     the function called, the regex must include (?C) at appropriate points. This
2602     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2603     This provides a means of identifying different callout points. When PCRE
2604     reaches such a point in the regex, if pcre_callout has been set, the external
2605     function is called. It is provided with data in a structure called
2606     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2607     matching continues; if it returns a non-zero value, the match at the current
2608     point fails. However, backtracking will occur if possible. [This was changed
2609     later and other features added - see item 49 below.]
2610    
2611     29. pcretest is upgraded to test the callout functionality. It provides a
2612     callout function that displays information. By default, it shows the start of
2613     the match and the current position in the text. There are some new data escapes
2614     to vary what happens:
2615    
2616     \C+ in addition, show current contents of captured substrings
2617     \C- do not supply a callout function
2618     \C!n return 1 when callout number n is reached
2619     \C!n!m return 1 when callout number n is reached for the mth time
2620    
2621     30. If pcregrep was called with the -l option and just a single file name, it
2622     output "<stdin>" if a match was found, instead of the file name.
2623    
2624     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2625     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2626     pcre_exec(). This saves a malloc/free per call. The default value of
2627     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2628     when configuring.
2629    
2630     32. The default maximum size of a compiled pattern is 64K. There have been a
2631     few cases of people hitting this limit. The code now uses macros to handle the
2632     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2633     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2634     configuring. Tests 2 and 5 work only with 2-byte links because they output
2635     debugging information about compiled patterns.
2636    
2637     33. Internal code re-arrangements:
2638    
2639     (a) Moved the debugging function for printing out a compiled regex into
2640     its own source file (printint.c) and used #include to pull it into
2641     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2642     separate copies.
2643    
2644     (b) Defined the list of op-code names for debugging as a macro in
2645     internal.h so that it is next to the definition of the opcodes.
2646    
2647     (c) Defined a table of op-code lengths for simpler skipping along compiled
2648     code. This is again a macro in internal.h so that it is next to the
2649     definition of the opcodes.
2650    
2651     34. Added support for recursive calls to individual subpatterns, along the
2652     lines of Robin Houston's patch (but implemented somewhat differently).
2653    
2654     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2655     allow it to read and process whole directories in Win32. This code was
2656     contributed by Lionel Fourquaux; it has not been tested by me.
2657    
2658     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2659     used to name a group. Names consist of alphanumerics and underscores, and must
2660     be unique. Back references use the syntax (?P=name) and recursive calls use
2661     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2662     numbers. The function pcre_fullinfo() can be used after compilation to extract
2663     a name/number map. There are three relevant calls:
2664    
2665     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2666     PCRE_INFO_NAMECOUNT yields the number of entries
2667     PCRE_INFO_NAMETABLE yields a pointer to the map.
2668    
2669     The map is a vector of fixed-size entries. The size of each entry depends on
2670     the length of the longest name used. The first two bytes of each entry are the
2671     group number, most significant byte first. There follows the corresponding
2672     name, zero terminated. The names are in alphabetical order.
2673    
2674     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2675     case instead of 255. Making it the same both with and without UTF-8 support
2676     means that the same test output works with both.
2677    
2678     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2679     calling malloc() with a zero argument.
2680    
2681     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2682     optimization. I've improved things by keeping a bitmap of backreferences with
2683     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2684     fact referenced, the optimization can be applied. It is unlikely that a
2685     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2686     the match to follow \n) will appear inside brackets with a number greater than
2687     31, but if it does, any back reference > 31 suppresses the optimization.
2688    
2689     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2690     of disabling numbered capturing parentheses. Any opening parenthesis that is
2691     not followed by ? behaves as if it were followed by ?: but named parentheses
2692     can still be used for capturing (and they will acquire numbers in the usual
2693     way).
2694    
2695     41. Redesigned the return codes from the match() function into yes/no/error so
2696     that errors can be passed back from deep inside the nested calls. A malloc
2697     failure while inside a recursive subpattern call now causes the
2698     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2699    
2700     42. It is now possible to set a limit on the number of times the match()
2701     function is called in a call to pcre_exec(). This facility makes it possible to
2702     limit the amount of recursion and backtracking, though not in a directly
2703     obvious way, because the match() function is used in a number of different
2704     circumstances. The count starts from zero for each position in the subject
2705     string (for non-anchored patterns). The default limit is, for compatibility, a
2706     large number, namely 10 000 000. You can change this in two ways:
2707    
2708     (a) When configuring PCRE before making, you can use --with-match-limit=n
2709     to set a default value for the compiled library.
2710    
2711     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2712     a different value is set. See 45 below.
2713    
2714     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2715    
2716     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2717     of things that can be changed at compile time. The first argument specifies
2718     what is wanted and the second points to where the information is to be placed.
2719     The current list of available information is:
2720    
2721     PCRE_CONFIG_UTF8
2722    
2723     The output is an integer that is set to one if UTF-8 support is available;
2724     otherwise it is set to zero.
2725    
2726     PCRE_CONFIG_NEWLINE
2727    
2728     The output is an integer that it set to the value of the code that is used for
2729     newline. It is either LF (10) or CR (13).
2730    
2731     PCRE_CONFIG_LINK_SIZE
2732    
2733     The output is an integer that contains the number of bytes used for internal
2734     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2735    
2736     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2737    
2738     The output is an integer that contains the threshold above which the POSIX
2739     interface uses malloc() for output vectors. See item 31 above.
2740    
2741     PCRE_CONFIG_MATCH_LIMIT
2742    
2743     The output is an unsigned integer that contains the default limit of the number
2744     of match() calls in a pcre_exec() execution. See 42 above.
2745    
2746     44. pcretest has been upgraded by the addition of the -C option. This causes it
2747     to extract all the available output from the new pcre_config() function, and to
2748     output it. The program then exits immediately.
2749    
2750     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2751     order to support additional features. One way would have been to define
2752     pcre_exec2() (for example) with extra arguments, but this would not have been
2753     extensible, and would also have required all calls to the original function to
2754     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2755     is used for passing in "extra" data from pcre_study().
2756    
2757     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2758     contains the following fields:
2759    
2760     flags a bitmap indicating which of the following fields are set
2761     study_data opaque data from pcre_study()
2762     match_limit a way of specifying a limit on match() calls for a specific
2763     call to pcre_exec()
2764     callout_data data for callouts (see 49 below)
2765    
2766     The flag bits are also defined in pcre.h, and are
2767    
2768     PCRE_EXTRA_STUDY_DATA
2769     PCRE_EXTRA_MATCH_LIMIT
2770     PCRE_EXTRA_CALLOUT_DATA
2771    
2772     The pcre_study() function now returns one of these new pcre_extra blocks, with
2773     the actual study data pointed to by the study_data field, and the
2774     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2775     before. That is, this change is entirely upwards-compatible and requires no
2776     change to existing code.
2777    
2778     If you want to pass in additional data to pcre_exec(), you can either place it
2779     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2780     block.
2781    
2782     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2783     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2784     times with different match limits, until it finds the minimum value needed for
2785     pcre_exec() to complete. The value is then output. This can be instructive; for
2786     most simple matches the number is quite small, but for pathological cases it
2787     gets very large very quickly.
2788    
2789     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2790     returns the size of the data block pointed to by the study_data field in a
2791     pcre_extra block, that is, the value that was passed as the argument to
2792     pcre_malloc() when PCRE was getting memory in which to place the information
2793     created by pcre_study(). The fourth argument should point to a size_t variable.
2794     pcretest has been extended so that this information is shown after a successful
2795     pcre_study() call when information about the compiled regex is being displayed.
2796    
2797     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2798     because what follows is always an absolute path. (Later: it turns out that this
2799     is more than cosmetic for MinGW, because it doesn't like empty path
2800     components.)
2801    
2802     49. Some changes have been made to the callout feature (see 28 above):
2803    
2804     (i) A callout function now has three choices for what it returns:
2805    
2806     0 => success, carry on matching
2807     > 0 => failure at this point, but backtrack if possible
2808     < 0 => serious error, return this value from pcre_exec()
2809    
2810     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2811     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2812     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2813     use by callout functions. It will never be used by PCRE itself.
2814    
2815     (ii) The pcre_extra structure (see 45 above) has a void * field called
2816     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2817     pcre_callout_block structure has a field of the same name. The contents of
2818     the field passed in the pcre_extra structure are passed to the callout
2819     function in the corresponding field in the callout block. This makes it
2820     easier to use the same callout-containing regex from multiple threads. For
2821     testing, the pcretest program has a new data escape
2822    
2823     \C*n pass the number n (may be negative) as callout_data
2824    
2825     If the callout function in pcretest receives a non-zero value as
2826     callout_data, it returns that value.
2827    
2828     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2829     there were some redundant $(CFLAGS) in commands that are now specified as
2830     $(LINK), which already includes $(CFLAGS).
2831    
2832     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2833     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2834     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2835     one-byte characters throughout. Note that case-insensitive matching applies
2836     only to characters whose values are less than 256. PCRE doesn't support the
2837     notion of cases for higher-valued characters.
2838    
2839     (i) A character class whose characters are all within 0-255 is handled as
2840     a bit map, and the map is inverted for negative classes. Previously, a
2841     character > 255 always failed to match such a class; however it should
2842     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2843    
2844     (ii) A negated character class with a single character < 255 is coded as
2845     "not this character" (OP_NOT). This wasn't working properly when the test
2846     character was multibyte, either singly or repeated.
2847    
2848     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2849     mode, for example: \x{100}{2,3}.
2850    
2851     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2852     singly or repeated) now correctly test multibyte characters. However,
2853     PCRE doesn't recognize any characters with values greater than 255 as
2854     digits, spaces, or word characters. Such characters always match \D, \S,
2855     and \W, and never match \d, \s, or \w.
2856    
2857     (v) Classes may now contain characters and character ranges with values
2858     greater than 255. For example: [ab\x{100}-\x{400}].
2859    
2860     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2861     PCRE in UTF-8 mode.
2862    
2863     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2864     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2865     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2866     value.)
2867    
2868     53. The single man page has become too large. I have therefore split it up into
2869     a number of separate man pages. These also give rise to individual HTML pages;
2870     these are now put in a separate directory, and there is an index.html page that
2871     lists them all. Some hyperlinking between the pages has been installed.
2872    
2873     54. Added convenience functions for handling named capturing parentheses.
2874    
2875     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2876     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2877     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2878     are faulted.
2879    
2880     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2881     calling configure. These values are used when compiling the dftables.c program
2882     which is run to generate the source of the default character tables. They
2883     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2884     you will need to set these values.
2885    
2886     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2887    
2888    
2889     Version 3.9 02-Jan-02
2890 nigel 61 ---------------------
2891    
2892     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2893    
2894     2. If --disable-static was given, the building process failed when trying to
2895     build pcretest and pcregrep. (For some reason it was using libtool to compile
2896     them, which is not right, as they aren't part of the library.)
2897    
2898    
2899 nigel 59 Version 3.8 18-Dec-01
2900     ---------------------
2901    
2902     1. The experimental UTF-8 code was completely screwed up. It was packing the
2903     bytes in the wrong order. How dumb can you get?
2904    
2905    
2906 nigel 57 Version 3.7 29-Oct-01
2907     ---------------------
2908    
2909     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2910     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2911     this didn't happen under Solaris 8, where I normally test things.
2912    
2913 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2914     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2915     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2916     this fix an hour or so after the initial 3.7 release.)
2917 nigel 57
2918 nigel 59
2919 nigel 55 Version 3.6 23-Oct-01
2920     ---------------------
2921    
2922     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2923     offsets passed as NULL with zero offset count.
2924    
2925     2. The config.guess and config.sub files had not been updated when I moved to
2926     the latest autoconf.
2927    
2928    
2929 nigel 53 Version 3.5 15-Aug-01
2930     ---------------------
2931 nigel 5
2932 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2933     had been forgotten.
2934    
2935     2. By using declared but undefined structures, we can avoid using "void"
2936     definitions in pcre.h while keeping the internal definitions of the structures
2937     private.
2938    
2939     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2940     user point of view, this means that both static and shared libraries are built
2941     by default, but this can be individually controlled. More of the work of
2942     handling this static/shared cases is now inside libtool instead of PCRE's make
2943     file.
2944    
2945     4. The pcretest utility is now installed along with pcregrep because it is
2946     useful for users (to test regexs) and by doing this, it automatically gets
2947     relinked by libtool. The documentation has been turned into a man page, so
2948     there are now .1, .txt, and .html versions in /doc.
2949    
2950     5. Upgrades to pcregrep:
2951     (i) Added long-form option names like gnu grep.
2952     (ii) Added --help to list all options with an explanatory phrase.
2953     (iii) Added -r, --recursive to recurse into sub-directories.
2954     (iv) Added -f, --file to read patterns from a file.
2955    
2956     6. pcre_exec() was referring to its "code" argument before testing that
2957     argument for NULL (and giving an error if it was NULL).
2958    
2959     7. Upgraded Makefile.in to allow for compiling in a different directory from
2960     the source directory.
2961    
2962     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2963     options bits, the pointer it was passed was to an int instead of to an unsigned
2964     long int. This mattered only on 64-bit systems.
2965    
2966     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2967     generated) instead of pcre.in, which it its source. Also made the same change
2968     in several of the .c files.
2969    
2970     10. A new release of gcc defines printf() as a macro, which broke pcretest
2971     because it had an ifdef in the middle of a string argument for printf(). Fixed
2972     by using separate calls to printf().
2973    
2974     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2975     script, to force use of CR or LF instead of \n in the source. On non-Unix
2976     systems, the value can be set in config.h.
2977    
2978     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2979     absolute limit. Changed the text of the error message to make this clear, and
2980     likewise updated the man page.
2981    
2982     13. The limit of 99 on the number of capturing subpatterns has been removed.
2983     The new limit is 65535, which I hope will not be a "real" limit.
2984    
2985    
2986 nigel 51 Version 3.4 22-Aug-00
2987     ---------------------
2988    
2989     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2990    
2991     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2992    
2993    
2994 nigel 49 Version 3.3 01-Aug-00
2995     ---------------------
2996    
2997     1. If an octal character was given, but the value was greater than \377, it
2998     was not getting masked to the least significant bits, as documented. This could
2999     lead to crashes in some systems.
3000    
3001     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3002     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3003    
3004     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3005     These just pass their arguments on to (pcre_free)(), but they are provided
3006     because some uses of PCRE bind it to non-C systems that can call its functions,
3007     but cannot call free() or pcre_free() directly.
3008    
3009     4. Add "make test" as a synonym for "make check". Corrected some comments in
3010     the Makefile.
3011    
3012     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3013     Makefile.
3014    
3015     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3016     command called pgrep for grepping around the active processes.
3017    
3018     7. Added the beginnings of support for UTF-8 character strings.
3019    
3020     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3021     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3022     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3023     out for the ar command.)
3024    
3025    
3026 nigel 47 Version 3.2 12-May-00
3027     ---------------------
3028    
3029     This is purely a bug fixing release.
3030    
3031     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3032     of ZA. This was just one example of several cases that could provoke this bug,
3033     which was introduced by change 9 of version 2.00. The code for breaking
3034     infinite loops after an iteration that matches an empty string was't working
3035     correctly.
3036    
3037     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3038     when matched against abbab (for example). After matching an empty string, it
3039     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3040     caused it to match further down the string than it should.
3041    
3042     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3043     was there because it doesn't seem to be needed, and it causes trouble on some
3044     systems, as it is not a Standard C header. It has been removed.
3045    
3046     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3047     were reported on the Macintosh. The changes were from
3048    
3049     while ((c = *(++ptr)) != 0 && c != '\n');
3050     to
3051     while ((c = *(++ptr)) != 0 && c != '\n') ;
3052    
3053     Totally extraordinary, but if that's what it takes...
3054    
3055     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3056     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3057     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3058     assumes the way PCRE uses memmove() (always moving upwards).
3059    
3060     6. PCRE is being used in one environment where strchr() is not available. There
3061     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3062     faster code anyway.
3063    
3064    
3065 nigel 45 Version 3.1 09-Feb-00
3066     ---------------------
3067    
3068     The only change in this release is the fixing of some bugs in Makefile.in for
3069     the "install" target:
3070    
3071     (1) It was failing to install pcreposix.h.
3072    
3073     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3074    
3075    
3076 nigel 43 Version 3.0 01-Feb-00
3077     ---------------------
3078 nigel 41
3079     1. Add support for the /+ modifier to perltest (to output $` like it does in
3080     pcretest).
3081    
3082     2. Add support for the /g modifier to perltest.
3083    
3084     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3085     matches null strings.
3086    
3087     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3088     pattern. Perl treats empty patterns specially - it reuses the most recent
3089     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3090     effect.
3091    
3092     5. The POSIX interface was broken in that it was just handing over the POSIX
3093     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3094     required a bigger vector, with some working space on the end. This means that
3095     the POSIX wrapper now has to get and free some memory, and copy the results.
3096    
3097 nigel 43 6. Added some simple autoconf support, placing the test data and the
3098     documentation in separate directories, re-organizing some of the
3099     information files, and making it build pcre-config (a GNU standard). Also added
3100     libtool support for building PCRE as a shared library, which is now the
3101     default.
3102 nigel 41
3103 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3104     09 are not valid octal constants. Single digits will be used for minor values
3105     less than 10.
3106    
3107     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3108     existing programs that set these in the POSIX interface can use PCRE without
3109     modification.
3110    
3111     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3112     return all that pcre_info() returns, plus additional data. The pcre_info()
3113     function is retained for compatibility, but is considered to be obsolete.
3114    
3115     10. Added experimental recursion feature (?R) to handle one common case that
3116     Perl 5.6 will be able to do with (?p{...}).
3117    
3118     11. Added support for POSIX character classes like [:alpha:], which Perl is
3119     adopting.
3120    
3121    
3122 nigel 39 Version 2.08 31-Aug-99
3123     ----------------------
3124    
3125     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3126     trying to match at the startoffset position, but instead was moving forward to
3127     the next newline as if a previous match had failed.
3128    
3129     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3130     and could get into a loop if a null string was matched other than at the start
3131     of the subject.
3132    
3133     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3134     be distinguished at compile time, and for completeness also added PCRE_DATE.
3135    
3136     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3137     in GnuWin32 environments.
3138    
3139    
3140 nigel 37 Version 2.07 29-Jul-99
3141     ----------------------
3142    
3143     1. The documentation is now supplied in plain text form and HTML as well as in
3144     the form of man page sources.
3145    
3146     2. C++ compilers don't like assigning (void *) values to other pointer types.
3147     In particular this affects malloc(). Although there is no problem in Standard
3148     C, I've put in casts to keep C++ compilers happy.
3149    
3150     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3151     should be (const char *).
3152    
3153     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3154     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3155     However, I haven't made this a standard facility. The documentation doesn't
3156     mention it, and the Makefile doesn't support it.
3157    
3158     5. The Makefile now contains an "install" target, with editable destinations at
3159     the top of the file. The pcretest program is not installed.
3160    
3161     6. pgrep -V now gives the PCRE version number and date.
3162    
3163     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3164     causing the entire string to be ignored, instead of just the last character.
3165    
3166     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3167     non-matching string, it can take a very, very long time, even for strings of
3168     quite modest length, because of the nested recursion. PCRE now does better in
3169     some of these cases. It does this by remembering the last required literal
3170     character in the pattern, and pre-searching the subject to ensure it is present
3171     before running the real match. In other words, it applies a heuristic to detect
3172     some types of certain failure quickly, and in the above example, if presented
3173     with a string that has no trailing " it gives "no match" very quickly.
3174    
3175     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3176     other alternatives are tried instead.
3177    
3178    
3179 nigel 35 Version 2.06 09-Jun-99
3180     ----------------------
3181    
3182     1. Change pcretest's output for amount of store used to show just the code
3183     space, because the remainder (the data block) varies in size between 32-bit and
3184     64-bit systems.
3185    
3186     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3187     start matching at. This allows lookbehinds to work when searching for multiple
3188     occurrences in a string.
3189    
3190     3. Added additional options to pcretest for testing multiple occurrences:
3191    
3192     /+ outputs the rest of the string that follows a match
3193     /g loops for multiple occurrences, using the new startoffset argument
3194     /G loops for multiple occurrences by passing an incremented pointer
3195    
3196     4. PCRE wasn't doing the "first character" optimization for patterns starting
3197     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3198     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3199     the letter 'x'. On long subject strings, this gives a significant speed-up.
3200    
3201    
3202 nigel 33 Version 2.05 21-Apr-99
3203     ----------------------
3204    
3205     1. Changed the type of magic_number from int to long int so that it works
3206     properly on 16-bit systems.
3207    
3208     2. Fixed a bug which caused patterns starting with .* not to work correctly
3209     when the subject string contained newline characters. PCRE was assuming
3210     anchoring for such patterns in all cases, which is not correct because .* will
3211     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3212     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3213     must be retried after every newline in the subject.
3214    
3215    
3216 nigel 31 Version 2.04 18-Feb-99
3217     ----------------------
3218    
3219     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3220     computation of the store needed to hold the pattern was incorrect (too large).
3221     If such patterns were nested a few deep, this could multiply and become a real
3222     problem.
3223    
3224     2. Added /M option to pcretest to show the memory requirement of a specific
3225     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3226    
3227     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3228     compiled in such a way that the backtracking after subsequent failure was
3229     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3230     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3231    
3232    
3233 nigel 29 Version 2.03 02-Feb-99
3234     ----------------------
3235    
3236     1. Fixed typo and small mistake in man page.
3237    
3238 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3239     LICENCE file containing the conditions.
3240 nigel 29
3241     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3242     Perl, that is the internal \ allows the delimiter to be included in the
3243     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3244     the final delimiter, add \ to the end of the pattern (to test the error).
3245    
3246     4. Added the convenience functions for extracting substrings after a successful
3247     match. Updated pcretest to make it able to test these functions.
3248    
3249    
3250 nigel 27 Version 2.02 14-Jan-99
3251     ----------------------
3252    
3253     1. Initialized the working variables associated with each extraction so that
3254     their saving and restoring doesn't refer to uninitialized store.
3255    
3256     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3257     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3258     fix the problem.
3259    
3260     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3261     calls, and wasn't printing the correct value for compiling calls. Increased the
3262     default value of LOOPREPEAT, and the number of significant figures in the
3263     times.
3264    
3265     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3266    
3267     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3268     a building problem on Windows NT with a FAT file system.
3269    
3270    
3271 nigel 25 Version 2.01 21-Oct-98
3272     ----------------------
3273    
3274     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3275     to character tables built by pcre_maketables() in the current locale. If NULL
3276     is passed, the default tables are used.
3277    
3278    
3279 nigel 23 Version 2.00 24-Sep-98
3280 nigel 21 ----------------------
3281    
3282 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3283     it any more.
3284    
3285     2. Allow quantification of (?>) groups, and make it work correctly.
3286    
3287     3. The first character computation wasn't working for (?>) groups.
3288    
3289     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3290     end of the subject) and add 5.005's \z, which really does match only at the
3291     very end of the subject.
3292    
3293     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3294    
3295     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3296     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3297     localized options. All options to pcre_study() were also removed.
3298    
3299     7. Add other new features from 5.005:
3300    
3301     $(?<= positive lookbehind
3302     $(?<! negative lookbehind
3303     (?imsx-imsx) added the unsetting capability
3304     such a setting is global if at outer level; local otherwise
3305     (?imsx-imsx:) non-capturing groups with option setting
3306     (?(cond)re|re) conditional pattern matching
3307    
3308     A backreference to itself in a repeated group matches the previous
3309     captured string.
3310    
3311     8. General tidying up of studying (both automatic and via "study")
3312     consequential on the addition of new assertions.
3313    
3314     9. As in 5.005, unlimited repeated groups that could match an empty substring
3315     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3316     runtime if any iteration does actually match an empty substring.
3317    
3318     10. Include the RunTest script in the distribution.
3319    
3320     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3321     discrepancies, some of which were old and were also with respect to 5.004. They
3322     have now been fixed.
3323    
3324    
3325     Version 1.09 28-Apr-98
3326     ----------------------
3327    
3328 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3329     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3330     program crashes, or just wrong answers. This did not apply to negated classes
3331     containing more than one character, or to minima other than one.
3332    
3333    
3334 nigel 19 Version 1.08 27-Mar-98
3335     ----------------------
3336    
3337     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3338    
3339     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3340     latter must appear before anything that relies on it in the pattern.
3341    
3342    
3343 nigel 17 Version 1.07 16-Feb-98
3344     ----------------------
3345    
3346     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3347     repeat of a potentially empty string).
3348    
3349    
3350 nigel 15 Version 1.06 23-Jan-98
3351     ----------------------
3352    
3353     1. Added Markus Oberhumer's little patches for C++.
3354    
3355     2. Literal strings longer than 255 characters were broken.
3356    
3357    
3358 nigel 13 Version 1.05 23-Dec-97
3359     ----------------------
3360    
3361     1. Negated character classes containing more than one character were failing if
3362     PCRE_CASELESS was set at run time.
3363    
3364    
3365 nigel 11 Version 1.04 19-Dec-97
3366     ----------------------
3367    
3368     1. Corrected the man page, where some "const" qualifiers had been omitted.
3369    
3370     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3371     input syntax.
3372    
3373     3. Fixed memory leak which occurred when a regex with back references was
3374     matched with an offsets vector that wasn't big enough. The temporary memory
3375     that is used in this case wasn't being freed if the match failed.
3376    
3377     4. Tidied pcretest to ensure it frees memory that it gets.
3378    
3379     5. Temporary memory was being obtained in the case where the passed offsets
3380     vector was exactly big enough.
3381    
3382     6. Corrected definition of offsetof() from change 5 below.
3383    
3384     7. I had screwed up change 6 below and broken the rules for the use of
3385     setjmp(). Now fixed.
3386    
3387    
3388 nigel 9 Version 1.03 18-Dec-97
3389     ----------------------
3390    
3391     1. A erroneous regex with a missing opening parenthesis was correctly
3392     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3393     on some systems.
3394    
3395     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3396     it was reported that one broken compiler failed on the former because "code" is
3397     also an independent variable.
3398    
3399     3. The erroneous regex a[]b caused an array overrun reference.
3400    
3401     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3402     fail on data ending with that character. (It was going on too far, and checking
3403     the next character, typically a binary zero.) This was specific to the
3404     optimized code for single-character negative classes.
3405    
3406     5. Added a contributed patch from the TIN world which does the following:
3407    
3408     + Add an undef for memmove, in case the the system defines a macro for it.
3409    
3410     + Add a definition of offsetof(), in case there isn't one. (I don't know
3411     the reason behind this - offsetof() is part of the ANSI standard - but
3412     it does no harm).
3413    
3414     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3415     most of the places where whitespace preceded '#'. I have given up and
3416     allowed the remaining 2 cases to be at the margin.
3417    
3418     + Rename some variables in pcre to eliminate shadowing. This seems very
3419     pedantic, but does no harm, of course.
3420    
3421     6. Moved the call to setjmp() into its own function, to get rid of warnings
3422     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3423    
3424     7. Constructs such as \d{8,} were compiling into the equivalent of
3425 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3426 nigel 9 outcome, but in this particular case used more store than had been allocated,
3427     which caused the bug to be discovered because it threw up an internal error.
3428    
3429     8. The debugging code in both pcre and pcretest for outputting the compiled
3430     form of a regex was going wrong in the case of back references followed by
3431     curly-bracketed repeats.
3432    
3433    
3434 nigel 7 Version 1.02 12-Dec-97
3435     ----------------------
3436    
3437     1. Typos in pcre.3 and comments in the source fixed.
3438    
3439     2. Applied a contributed patch to get rid of places where it used to remove
3440     'const' from variables, and fixed some signed/unsigned and uninitialized
3441     variable warnings.
3442    
3443     3. Added the "runtest" target to Makefile.
3444    
3445     4. Set default compiler flag to -O2 rather than just -O.
3446    
3447    
3448 nigel 5 Version 1.01 19-Nov-97
3449     ----------------------
3450    
3451     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3452     like /([ab]*)*/, that is, for classes with more than one character in them.
3453    
3454     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3455     as /((?>a*))*/ (a PCRE_EXTRA facility).
3456    
3457    
3458     Version 1.00 18-Nov-97
3459     ----------------------
3460    
3461     1. Added compile-time macros to support systems such as SunOS4 which don't have
3462     memmove() or strerror() but have other things that can be used instead.
3463    
3464     2. Arranged that "make clean" removes the executables.
3465    
3466    
3467 nigel 3 Version 0.99 27-Oct-97
3468     ----------------------
3469    
3470     1. Fixed bug in code for optimizing classes with only one character. It was
3471     initializing a 32-byte map regardless, which could cause it to run off the end
3472     of the memory it had got.
3473    
3474     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3475    
3476    
3477     Version 0.98 22-Oct-97
3478     ----------------------
3479    
3480     1. Fixed bug in code for handling temporary memory usage when there are more
3481     back references than supplied space in the ovector. This could cause segfaults.
3482    
3483    
3484     Version 0.97 21-Oct-97
3485     ----------------------
3486    
3487     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3488    
3489     2. Optimized negated single characters not to use a bit map.
3490    
3491     3. Brought error texts together as macro definitions; clarified some of them;
3492     fixed one that was wrong - it said "range out of order" when it meant "invalid
3493     escape sequence".
3494    
3495     4. Changed some char * arguments to const char *.
3496    
3497     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3498    
3499     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3500     pcretest.
3501    
3502    
3503     Version 0.96 16-Oct-97
3504     ----------------------
3505    
3506     1. Added a simple "pgrep" utility to the distribution.
3507    
3508     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3509     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3510     where "ddd" means "one or more decimal digits".
3511    
3512     3. Fixed serious bug. If a pattern had a back reference, but the call to
3513     pcre_exec() didn't supply a large enough ovector to record the related
3514     identifying subpattern, the match always failed. PCRE now remembers the number
3515     of the largest back reference, and gets some temporary memory in which to save
3516     the offsets during matching if necessary, in order to ensure that
3517     backreferences always work.
3518    
3519     4. Increased the compatibility with Perl in a number of ways:
3520    
3521     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3522     to request this handling. The option can be set at compile or exec time.
3523    
3524     (b) $ matches before a terminating newline by default; an option
3525     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3526     mode). The option can be set at compile or exec time.
3527    
3528     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3529     the same as Perl's. If the decimal number it represents is less than 10
3530     or there aren't that many previous left capturing parentheses, an octal
3531     escape is read. Inside a character class, it's always an octal escape,
3532     even if it is a single digit.
3533    
3534     (d) An escaped but undefined alphabetic character is taken as a literal,
3535     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3536     escapes.
3537    
3538     (e) {0} is now permitted. (The previous item is removed from the compiled
3539     pattern).
3540    
3541     5. Changed all the names of code files so that the basic parts are no longer
3542     than 10 characters, and abolished the teeny "globals.c" file.
3543    
3544     6. Changed the handling of character classes; they are now done with a 32-byte
3545     bit map always.
3546    
3547     7. Added the -d and /D options to pcretest to make it possible to look at the
3548     internals of compilation without having to recompile pcre.
3549    
3550    
3551     Version 0.95 23-Sep-97
3552     ----------------------
3553    
3554     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3555     \x20 at the start of a run of normal characters. These were being treated as
3556     real characters, instead of the source characters being re-checked.
3557    
3558    
3559     Version 0.94 18-Sep-97
3560     ----------------------
3561    
3562     1. The functions are now thread-safe, with the caveat that the global variables
3563     containing pointers to malloc() and free() or alternative functions are the
3564     same for all threads.
3565    
3566     2. Get pcre_study() to generate a bitmap of initial characters for non-
3567     anchored patterns when this is possible, and use it if passed to pcre_exec().
3568    
3569    
3570     Version 0.93 15-Sep-97
3571     ----------------------
3572    
3573     1. /(b)|(:+)/ was computing an incorrect first character.
3574    
3575     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3576     but not actually doing anything yet.
3577    
3578     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3579     as Perl does (e.g. [-az] or [az-]).
3580    
3581     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3582     all possible positions.
3583    
3584     5. Split up into different modules to avoid including unneeded functions in a
3585     compiled binary. However, compile and exec are still in one module. The "study"
3586     function is split off.
3587    
3588     6. The character tables are now in a separate module whose source is generated
3589     by an auxiliary program - but can then be edited by hand if required. There are
3590     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3591     toupper() in the code.
3592    
3593     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3594     make them global. Abolish the function for setting them, as the caller can now
3595     set them directly.
3596    
3597    
3598     Version 0.92 11-Sep-97
3599     ----------------------
3600    
3601     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3602     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3603    
3604     2. Caseless matching was not working in character classes if the characters in
3605     the pattern were in upper case.
3606    
3607     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3608    
3609     4. Make PCRE_ANCHORED public and accept as a compile option.
3610    
3611     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3612     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3613     pass them.
3614    
3615     6. Give an error if bad option bits passed at compile or run time.
3616    
3617     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3618     pcretest to cause it to pass that flag.
3619    
3620     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3621     options, and the first character, if set.
3622    
3623     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3624    
3625    
3626     Version 0.91 10-Sep-97
3627     ----------------------
3628    
3629     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3630     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3631    
3632     2. PCRE was looping on encountering an indefinitely repeated back reference to
3633     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3634     Perl does - treats the match as successful.
3635    
3636     ****

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