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Revision 481 - (hide annotations) (download)
Sun Jan 3 17:45:53 2010 UTC (5 years, 3 months ago) by ph10
File size: 179096 byte(s)
Forbid 08 and 09 as minor version numbers.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 471 Version 8.01 11-Dec-09
5     ----------------------
7     1. If a pattern contained a conditional subpattern with only one branch (in
8 ph10 473 particular, this includes all (DEFINE) patterns), a call to pcre_study()
9     computed the wrong minimum data length (which is of course zero for such
10 ph10 471 subpatterns).
11 ph10 473
12     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
13 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
14     "internal error: code overflow at offset...". This happened only when
15 ph10 473 the reset was to the original external option setting. (An optimization
16     abstracts leading options settings into an external setting, which was the
17 ph10 472 cause of this.)
18 ph10 471
19 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
20     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
21     assertion pattern did not match (meaning that the assertion was true), it
22     was incorrectly treated as false if the SKIP had been reached during the
23     matching. This also applied to assertions used as conditions.
24 ph10 471
25 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
26     assertion subpattern, including such a pattern used as a condition,
27     unpredictable results occurred, instead of the error return
29 ph10 478
30 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
31     situation when an empty string is matched. It now does the fancy magic
32 ph10 478 stuff that is necessary.
34     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
35 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
36 ph10 478
37 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
38     as part of something else:
39 ph10 478
40     (a) Change DEBUG to PCRE_DEBUG.
42     (b) In pcre_compile(), rename the member of the "branch_chain" structure
43     called "current" as "current_branch", to prevent a collision with the
44 ph10 475 Linux macro when compiled as a kernel module.
45 ph10 478
46     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
47     prevent a collision with the Linux macro when compiled as a kernel
48 ph10 475 module.
49 ph10 478
50 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
51     cast potentially large values to (double). This has been changed to that
52 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
53     instead, thus avoiding the use of floating point arithmetic. (There is no
54     other use of FP in PCRE.) If int64_t is not found, the fallback is to
55     double.
57     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
58 ph10 476 2005 (difference between two addresses compared to an unsigned value).
59 ph10 473
60 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
61     custom one, because of the following reported problem in Windows:
62 ph10 473
63 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
64     under Win32.
65     - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
66     therefore missing the function definition.
67     - The compiler thus generates a "C" signature for the test function.
68     - The linker fails to find the "C" function.
69     - PCRE fails to configure if asked to do so against libbz2.
70 ph10 479
71     11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
72     messages were output:
73 ph10 478
74 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
75     rerunning libtoolize, to keep the correct libtool macros in-tree.
76     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
78     I have done both of these things.
79 ph10 480
80     12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
81     most of the time, it *can* run out if it is given a pattern that contains a
82     runaway infinite recursion. I updated the discussion in the pcrestack man
83     page.
84 ph10 481
85     13. Now that we have gone to the x.xx style of version numbers, the minor
86     version may start with zero. Using 08 or 09 is a bad idea because users
87     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
88     interpreted as invalid octal numbers. I've updated the previous comment in
89     configure.ac, and also added a check that gives an error if 08 or 09 are
90     used.
91 ph10 479
92 ph10 478
93 ph10 479
94 ph10 469 Version 8.00 19-Oct-09
95 ph10 418 ----------------------
97     1. The table for translating pcre_compile() error codes into POSIX error codes
98 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
99     being within the table. This could lead to an OK return being given in
100 ph10 418 error.
101 ph10 461
102     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
103     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
104     in a Windows environment.
106 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
107     zero, as does GNU grep. However, pcregrep was also printing all files when
108     --files-with-matches was added. Now, when both options are given, it prints
109     counts only for those files that have at least one match. (GNU grep just
110 ph10 461 prints the file name in this circumstance, but including the count seems
111     more useful - otherwise, why use --count?) Also ensured that the
112 ph10 420 combination -clh just lists non-zero counts, with no names.
113 ph10 461
114     4. The long form of the pcregrep -F option was incorrectly implemented as
115     --fixed_strings instead of --fixed-strings. This is an incompatible change,
116     but it seems right to fix it, and I didn't think it was worth preserving
117     the old behaviour.
119     5. The command line items --regex=pattern and --regexp=pattern were not
120 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
121 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
122 ph10 422 which are compatible with GNU grep; these now work.
123 ph10 461
124     6. No libpcreposix.pc file was created for pkg-config; there was just
125 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
126 ph10 461
127 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
128 ph10 461 when UCP support is not needed, by modifying the Python script that
129 ph10 425 generates it from Unicode data files. This should not matter if the module
130     is correctly used as a library, but I received one complaint about 50K of
131     unwanted data. My guess is that the person linked everything into his
132     program rather than using a library. Anyway, it does no harm.
133 ph10 461
134 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
135 ph10 461 was a minimum greater than 1 for a wide character in a possessive
136 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
137     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
138     character. Chaos in the form of incorrect output or a compiling loop could
139     result.
140 ph10 461
141 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
142 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
143 ph10 426 partially matched by this function. In addition, if there are at least two
144 ph10 435 slots in the offset vector, the offset of the earliest inspected character
145     for the match and the offset of the end of the subject are set in them when
146 ph10 461 PCRE_ERROR_PARTIAL is returned.
148 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
149     synonymous with PCRE_PARTIAL, for backwards compatibility, and
150     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
151 ph10 462 and may be more useful for multi-segment matching.
152 ph10 461
153     11. Partial matching with pcre_exec() is now more intuitive. A partial match
154     used to be given if ever the end of the subject was reached; now it is
155     given only if matching could not proceed because another character was
156     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
157     string "Z", which now yields "no match" instead of "partial match". In the
158     case of pcre_dfa_exec(), "no match" is given if every matching path for the
159     final character ended with (*FAIL).
161 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
162 ph10 461 if the pattern had a "must contain" character that was already found in the
163 ph10 428 earlier partial match, unless partial matching was again requested. For
164     example, with the pattern /dog.(body)?/, the "must contain" character is
165     "g". If the first part-match was for the string "dog", restarting with
166 ph10 435 "sbody" failed. This bug has been fixed.
167 ph10 461
168     13. The string returned by pcre_dfa_exec() after a partial match has been
169     changed so that it starts at the first inspected character rather than the
170     first character of the match. This makes a difference only if the pattern
171     starts with a lookbehind assertion or \b or \B (\K is not supported by
172     pcre_dfa_exec()). It's an incompatible change, but it makes the two
173 ph10 435 matching functions compatible, and I think it's the right thing to do.
174 ph10 461
175 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
176 ph10 461 so that the demonstration program is easily available in environments where
177     PCRE has not been installed from source.
179 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
180 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
181     library.
182 ph10 461
183 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
184 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
185 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
186 ph10 433 these options useful.
187 ph10 461
188     17. If a caller to the POSIX matching function regexec() passes a non-zero
189 ph10 438 value for nmatch with a NULL value for pmatch, the value of
190 ph10 461 nmatch is forced to zero.
192 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
193 ph10 461 the diff command, as RunTest does. It now checks in the same way as
194 ph10 437 RunTest, and also checks for the -b option.
195 ph10 461
196 ph10 438 19. If an odd number of negated classes containing just a single character
197     interposed, within parentheses, between a forward reference to a named
198 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
199     an internal error, complaining that it could not find the referenced
200 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
201 ph10 461 [The bug was that it was starting one character too far in when skipping
202     over the character class, thus treating the ] as data rather than
203     terminating the class. This meant it could skip too much.]
205 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
206 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
207 ph10 442 to have an empty string match not at the start, even when the pattern is
208 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
210 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
211 ph10 461 than the maximum at the outer level, the higher number was returned, but
212     with unset values at the outer level. The correct (outer level) value is
213 ph10 446 now given.
214 ph10 461
215 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
216     PCRE did not set those parentheses (unlike Perl). I have now found a way to
217     make it do so. The string so far is captured, making this feature
218     compatible with Perl.
219 ph10 461
220     23. The tests have been re-organized, adding tests 11 and 12, to make it
221 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
222 ph10 461
223 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
224 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
225     does. Neither allows recursion.
227     25. I finally figured out how to implement a request to provide the minimum
228     length of subject string that was needed in order to match a given pattern.
229     (It was back references and recursion that I had previously got hung up
230     on.) This code has now been added to pcre_study(); it finds a lower bound
231 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
232     bound, but using it to avoid searching strings that are too short does give
233     some useful speed-ups. The value is available to calling programs via
234     pcre_fullinfo().
235 ph10 461
236 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
237     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
238     study optimizations had never been tested with that matching function.
239     Oops. What is worse, even when it was passed study data, there was a bug in
240     pcre_dfa_exec() that meant it never actually used it. Double oops. There
241     were also very few tests of studied patterns with pcre_dfa_exec().
242 ph10 461
243 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
244     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
245     on the other side of the coin, they are no longer allowed to have different
246     names, because these cannot be distinguished in PCRE, and this has caused
247     confusion. (This is a difference from Perl.)
248 ph10 461
249     28. When duplicate subpattern names are present (necessarily with different
250     numbers, as required by 27 above), and a test is made by name in a
251     conditional pattern, either for a subpattern having been matched, or for
252     recursion in such a pattern, all the associated numbered subpatterns are
253 ph10 459 tested, and the overall condition is true if the condition is true for any
254     one of them. This is the way Perl works, and is also more like the way
255     testing by number works.
256 ph10 418
257 ph10 461
258 ph10 412 Version 7.9 11-Apr-09
259 ph10 376 ---------------------
261 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
262 ph10 376 (pcretest), all targets were linked against these libraries. This included
263     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
264     libraries. This caused unwanted dependencies to be created. This problem
265 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
266 ph10 376 pcretest is linked with readline.
267 ph10 392
268 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
269     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
270     moved outside it again, because FALSE and TRUE are already defined in AIX,
271     but BOOL is not.
272 ph10 392
273     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
274 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
275 ph10 392
276 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
277     hyphens) following file names and line numbers when outputting matching
278 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
279 ph10 376 wording for the --colour (or --color) option.
280 ph10 392
281 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
282     was not coloured; this is different to GNU grep, so I have changed it to be
283     the same.
284 ph10 392
285 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
286 ph10 392 each matching line was coloured. Now it goes on to look for further matches
287     of any of the test patterns, which is the same behaviour as GNU grep.
289     7. A pattern that could match an empty string could cause pcregrep to loop; it
290     doesn't make sense to accept an empty string match in pcregrep, so I have
291 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
292     seems to be how GNU grep behaves.
293 ph10 392
294 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
295 ph10 392 start or after a newline", because the conditional assertion was not being
296     correctly handled. The rule now is that both the assertion and what follows
297     in the first alternative must satisfy the test.
299 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
300 ph10 399 condition was an assertion, PCRE could crash during matching, both with
301     pcre_exec() and pcre_dfa_exec().
302 ph10 392
303     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
304     used for matching.
306     11. Unicode property support in character classes was not working for
307 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
308 ph10 388
309 ph10 392 12. Added the -M command line option to pcretest.
311 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
312 ph10 389
313     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
314 ph10 390
315 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
316 ph10 390 wrapper.
317 ph10 392
318 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
319 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
320 ph10 391 string constants.
321 ph10 405
322 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
323     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
324 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
325     these, but not everybody uses configure.
327     19. A conditional group that had only one branch was not being correctly
328     recognized as an item that could match an empty string. This meant that an
329     enclosing group might also not be so recognized, causing infinite looping
330     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
331     with the subject "ab", where knowledge that the repeated group can match
332 ph10 396 nothing is needed in order to break the loop.
333 ph10 405
334 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
335 ph10 405 exec(), but without supplying a callout function, matching went wrong.
337     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
338     leak if the size of the offset vector was greater than 30. When the vector
339     is smaller, the saved offsets during recursion go onto a local stack
340     vector, but for larger vectors malloc() is used. It was failing to free
341     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
342 ph10 400 error, in fact).
343 ph10 405
344 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
345 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
346     problem, but was untidy.
347 ph10 376
348 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
349     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
350     included within another project.
351 ph10 411
352 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
353     slightly modified by me:
354 ph10 411
355     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
356     not building pcregrep.
358 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
359 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
361 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
362     duplicate group numbers, could behave incorrectly or give incorrect errors,
363     because when scanning forward to find the reference group, PCRE was not
364     taking into account the duplicate group numbers. A pattern such as
365     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
366 ph10 411
367     26. Changed a few more instances of "const unsigned char *" to USPTR, making
368     the feature of a custom pointer more persuasive (as requested by a user).
369 ph10 416
370 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
371 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
372     pre-defined.
373 ph10 392
374 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
376 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
377     in the configuration summary.
378 ph10 405
379 ph10 411
380 ph10 374 Version 7.8 05-Sep-08
381 ph10 349 ---------------------
383     1. Replaced UCP searching code with optimized version as implemented for Ad
384     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
385 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
386     to 5 times on some simple patterns that I tested. Permission was given to
387     distribute the MultiStage2.py script that generates the tables (it's not in
388     the tarball, but is in the Subversion repository).
389 ph10 349
390 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
391     scripts.
392 ph10 358
393 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
394     a group with a zero qualifier. The result of the study could be incorrect,
395 ph10 358 or the function might crash, depending on the pattern.
397     4. Caseless matching was not working for non-ASCII characters in back
398 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
399 ph10 358 It now works when Unicode Property Support is available.
401 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
402     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
403     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
404 ph10 358 truncation.
405 ph10 349
406 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
408 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
409     pointers, in case they are 64-bit values.
410 ph10 371
411     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
412     test 2 if it fails.
414 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
415 ph10 371 and a #define of that name to empty if it is not externally set. This is to
416     allow users of MSVC to set it if necessary.
418     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
419 ph10 359 the convenience functions in the pcre_get.c source file.
420 ph10 371
421 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
422     could cause overwriting and/or a crash. This command provoked a crash in
423 ph10 371 some environments:
425     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
427 ph10 360 This potential security problem was recorded as CVE-2008-2371.
428 ph10 371
429 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
430     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
431 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
432 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
433     pcretest so that it places the subject at the end of its malloc-ed buffer.
434 ph10 371
435 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
436 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
438 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
439 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
440     first line. This applied both to normal and DFA matching.
442 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
443 ph10 371 /^[^d]*?$/8 failed to match "abc".
444 ph10 351
445 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
447     17. Make it more clear in the documentation that values returned from
448 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
449 ph10 357
450 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
451 ph10 368
452 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
453     supplied by Stefan Weber. I made a further small update for 7.8 because
454 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
455     replaced by pcre_ucd.c.
456 ph10 371
457 ph10 373
458 ph10 347 Version 7.7 07-May-08
459 ph10 321 ---------------------
461     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
462 ph10 345 a string to a long long, pretend we don't even have a long long." This is
463 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
464 ph10 345
465 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
466     pre-7.6 versions, which defined a global no_arg variable instead of putting
467 ph10 332 it in the RE class. (See also #8 below.)
468 ph10 345
469     3. Remove a line of dead code, identified by coverity and reported by Nuno
470     Lopes.
472 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
473 ph10 321
474 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
475 ph10 345 of files, instead of just to the final components.
477 ph10 324 (2) If there was more than one level of directory, the subdirectories were
478     skipped unless they satisfied the include/exclude conditions. This is
479     inconsistent with GNU grep (and could even be seen as contrary to the
480     pcregrep specification - which I improved to make it absolutely clear).
481     The action now is always to scan all levels of directory, and just
482     apply the include/exclude patterns to regular files.
483 ph10 345
484 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
485 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
487 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
488 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
489 ph10 326 doesn't support NULs in patterns.
490 ph10 345
491     7. Added some missing "const"s to declarations of static tables in
492     pcre_compile.c and pcre_dfa_exec.c.
494 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
495 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
496 ph10 345 first patch. And a third patch - this was a messy problem.)
497 ph10 321
498 ph10 345 9. Applied Craig's patch to remove the use of push_back().
500 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
501     matching function regexec().
502 ph10 345
503     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
504     which, however, unlike Perl's \g{...}, are subroutine calls, not back
505 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
506     Oniguruma does).
507 ph10 345
508     12. Previously, a group with a zero repeat such as (...){0} was completely
509 ph10 335 omitted from the compiled regex. However, this means that if the group
510     was called as a subroutine from elsewhere in the pattern, things went wrong
511 ph10 345 (an internal error was given). Such groups are now left in the compiled
512     pattern, with a new opcode that causes them to be skipped at execution
513 ph10 335 time.
514 ph10 345
515 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
516     to the way PCRE behaves:
517 ph10 345
518 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
519 ph10 345
520     (b) A back reference to an unmatched subpattern matches an empty string
521 ph10 336 (Perl fails the current match path).
522 ph10 345
523 ph10 341 (c) A data ] in a character class must be notated as \] because if the
524 ph10 345 first data character in a class is ], it defines an empty class. (In
525 ph10 341 Perl it is not possible to have an empty class.) The empty class []
526     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
527     The negative empty class [^] matches any one character, independently
528     of the DOTALL setting.
529 ph10 345
530     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
531 ph10 340 non-existent subpattern following a character class starting with ']' and
532     containing () gave an internal compiling error instead of "reference to
533     non-existent subpattern". Fortunately, when the pattern did exist, the
534 ph10 345 compiled code was correct. (When scanning forwards to check for the
535 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
536 ph10 345 the class, so got the count wrong. When actually compiling, the reference
537 ph10 340 was subsequently set up correctly.)
538 ph10 345
539 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
540 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
541     other assertions are supported. I have made pcre_dfa_exec() support
542     (*FAIL).
544 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
545 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
546     cannot be changed at match time, I realized I could make a small
547     improvement to matching performance by compiling OP_ALLANY instead of
548     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
549     on the OP_ANY path.
551     17. Compiling pcretest on Windows with readline support failed without the
552 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
553 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
555 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
556 ph10 345 ncurses library to be included for pcretest when ReadLine support is
557     requested, but also to allow for it to be overridden. This patch came from
558     Daniel Bergström.
559 ph10 347
560 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
561 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
562     any errors with the current Unicode tables. Thanks to Peter Kankowski for
563     spotting this.
564 ph10 324
565 ph10 332
566 ph10 319 Version 7.6 28-Jan-08
567 ph10 300 ---------------------
569 ph10 302 1. A character class containing a very large number of characters with
570     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
571     overflow.
572 ph10 309
573     2. Patch to cut out the "long long" test in pcrecpp_unittest when
574     HAVE_LONG_LONG is not defined.
576 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
577 ph10 304 bring them up to date and include new features. This patch includes:
578 ph10 309
579 ph10 304 - Fixed PH's badly added libz and libbz2 support.
580     - Fixed a problem with static linking.
581 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
582 ph10 304 - Fixed dftables problem and added an option.
583     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
585     - Added readline support for pcretest.
586 ph10 309 - Added an listing of the option settings after cmake has run.
588 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
589     "pcre.dll" under mingw when using Configure/Make. I added stuff to
590     Makefile.am that cause it to include this special target, without
591     affecting anything else. Note that the same mingw target plus all
592     the other distribution libraries and programs are now supported
593     when configuring with CMake (see 6 below) instead of with
594     Configure/Make.
595 ph10 309
596 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
597     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
598 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
599     solves the problem, but it does no harm.
600 ph10 313
601 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
602 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
603 ph10 314 with CMake, and also correct the comment about stack recursion.
604 ph10 313
605 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
606 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
607     of a program that users should build themselves after PCRE is installed, so
608     building it automatically is not really right. What is more, it gave
609 ph10 312 trouble in some build environments.
610 ph10 300
611 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
612 ph10 308
613 ph10 319
614 ph10 298 Version 7.5 10-Jan-08
615 ph10 263 ---------------------
617     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
618     values in parens when parsing an RE using the C++ wrapper."
619 ph10 286
620 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
621     Characters greater than 255 were excluded from the class instead of being
622     included.
623 ph10 286
624     3. The same bug as (2) above applied to negated POSIX classes such as
625 ph10 265 [:^space:].
626 ph10 286
627 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
628     defined or documented. It seems to have been a typo for PCRE_STATIC, so
629 ph10 286 I have changed it.
631 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
632 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
633     first named subpattern whose name started with "a" (in other words, the
634 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
635     expected" is now given for (?&) (a zero-length name), and this patch also
636     makes it give the same error for \k'' (previously it complained that that
637     was a reference to a non-existent subpattern).
638 ph10 286
639 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
640 ph10 286 this is right because (?- can be followed by option settings as well as by
641 ph10 269 digits. I have, however, made the messages clearer.
642 ph10 286
643 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
644     than the number used in the conditional) now cause a compile-time error.
645     This is actually not compatible with Perl, which accepts such patterns, but
646     treats the conditional as always being FALSE (as PCRE used to), but it
647     seems to me that giving a diagnostic is better.
648 ph10 286
649 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
650 ph10 275 and messages.
651 ph10 286
652     9. Fix two occurrences of "backslash" in comments that should have been
653     "backspace".
655     10. Remove two redundant lines of code that can never be obeyed (their function
656     was moved elsewhere).
658     11. The program that makes PCRE's Unicode character property table had a bug
659     which caused it to generate incorrect table entries for sequences of
660 ph10 277 characters that have the same character type, but are in different scripts.
661 ph10 286 It amalgamated them into a single range, with the script of the first of
662 ph10 277 them. In other words, some characters were in the wrong script. There were
663     thirteen such cases, affecting characters in the following ranges:
664 ph10 286
665 ph10 277 U+002b0 - U+002c1
666     U+0060c - U+0060d
667 ph10 286 U+0061e - U+00612
668 ph10 277 U+0064b - U+0065e
669     U+0074d - U+0076d
670     U+01800 - U+01805
671     U+01d00 - U+01d77
672     U+01d9b - U+01dbf
673     U+0200b - U+0200f
674     U+030fc - U+030fe
675     U+03260 - U+0327f
676     U+0fb46 - U+0fbb1
677     U+10450 - U+1049d
678 ph10 286
679 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
680     compatible with GNU grep in that, if there was more than one match in a
681     line, it showed only the first of them. It now behaves in the same way as
682     GNU grep.
683 ph10 286
684     13. If the -o and -v options were combined for pcregrep, it printed a blank
685     line for every non-matching line. GNU grep prints nothing, and pcregrep now
686     does the same. The return code can be used to tell if there were any
687     non-matching lines.
689 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
691     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
692 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
693 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
694     and both kinds of lookbehind were skipped).
696 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
697 ph10 284 inclusion of <windows.h> to before rather than after the definition of
698     INVALID_FILE_ATTRIBUTES (patch from David Byron).
699 ph10 263
700 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
701 ph10 286 character property caused pcre_compile() to compile bad code, which led at
702     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
703     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
704     caused the error; without that there was no problem.
705 ph10 263
706 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
707 ph10 286
708 ph10 289 19. Added --enable-pcretest-libreadline.
709 ph10 286
710 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
711 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
712 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
713     later patch that removed the other one (the right fix) and added unit tests
714     that check the return values (which was not done before).
715 ph10 292
716 ph10 291 21. Several CMake things:
717 ph10 287
718 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
719 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
720 ph10 288
721 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
722     linked with the newly-built libraries, not previously installed ones.
723 ph10 291
725 ph10 298
726     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
727     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
728     UTF-8 newline character). The key issue is that the pattern starts .*;
729     this means that the match must be either at the beginning, or after a
730     newline. The bug was in the code for advancing after a failed match and
731     checking that the new position followed a newline. It was not taking
732 ph10 294 account of UTF-8 characters correctly.
733 ph10 298
734     23. PCRE was behaving differently from Perl in the way it recognized POSIX
735     character classes. PCRE was not treating the sequence [:...:] as a
736     character class unless the ... were all letters. Perl, however, seems to
737     allow any characters between [: and :], though of course it rejects as
738     unknown any "names" that contain non-letters, because all the known class
739     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
740     for example, whereas PCRE did not - it did not recognize a POSIX character
741     class. This seemed a bit dangerous, so the code has been changed to be
742     closer to Perl. The behaviour is not identical to Perl, because PCRE will
743     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
744     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
745     Perl does, and where it didn't before.
747 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
748     Windows environments %n is disabled by default.
749 ph10 292
751 ph10 260 Version 7.4 21-Sep-07
752 ph10 230 ---------------------
754     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
755 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
756     LF". That isn't really right - the whole point of the change was to try to
757     help when there was an actual mention of one of the two characters. So now
758     the change happens only if \r or \n (or a literal CR or LF) character is
759 ph10 230 encountered.
760 ph10 231
761     2. The 32-bit options word was also used for 6 internal flags, but the numbers
762     of both had grown to the point where there were only 3 bits left.
763     Fortunately, there was spare space in the data structure, and so I have
764     moved the internal flags into a new 16-bit field to free up more option
765 ph10 230 bits.
766 ph10 231
767     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
768     but did not set the internal JCHANGED flag - either of these is enough to
769     control the way the "get" function works - but the PCRE_INFO_JCHANGED
770     facility is supposed to tell if (?J) was ever used, so now (?J) at the
771 ph10 230 start sets both bits.
773 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
774     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
775 ph10 230
776 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
778     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
779 ph10 233 compatibility, even though it is no longer used.
780 ph10 243
781     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
782 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
783 ph10 259 windows.h file is present (where different names are used). [This was
784 ph10 257 reversed later after testing - see 16 below.]
785 ph10 243
786     8. Changed all #include <config.h> to #include "config.h". There were also
787 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
788 ph10 243
789 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
790 ph10 243 sequence off the lines that it output.
792     10. It was pointed out to me that arrays of string pointers cause lots of
793     relocations when a shared library is dynamically loaded. A technique of
794     using a single long string with a table of offsets can drastically reduce
795     these. I have refactored PCRE in four places to do this. The result is
796 ph10 240 dramatic:
797 ph10 243
798 ph10 240 Originally: 290
799     After changing UCP table: 187
800 ph10 243 After changing error message table: 43
801 ph10 240 After changing table of "verbs" 36
802     After changing table of Posix names 22
803 ph10 243
804 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
805 ph10 247
806 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
807 ph10 247 unicode-properties was also set.
809 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
810 ph10 231
811 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
812     checked only for CRLF.
813 ph10 233
814 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
816 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
817 ph10 253
818 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
819 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
820     entirely. This removes changes made in 7 above.
821 ph10 256
822 ph10 261 17. The CMake files have been updated, and there is now more information about
823     building with CMake in the NON-UNIX-USE document.
824 ph10 257
825 ph10 261
826 ph10 228 Version 7.3 28-Aug-07
827 ph10 157 ---------------------
829 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
830     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
831     brackets there is not right, since it causes compilers to look for an
832     installed pcre.h, not the version that is in the source that is being
833     compiled (which of course may be different). I have changed it back to:
834 ph10 197
835 ph10 189 #include "pcre.h"
836 ph10 197
837     I have a vague recollection that the change was concerned with compiling in
838     different directories, but in the new build system, that is taken care of
839     by the VPATH setting the Makefile.
841 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
842     when the subject happened to end in the byte 0x85 (e.g. if the last
843     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
844     characters but of course it shouldn't be taken as a newline when it is part
845     of another character. The bug was that, for an unlimited repeat of . in
846     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
847     characters when looking for a newline.
848 ph10 197
849     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
851     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
852     in debug output.
854 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
855     long printing in the pcrecpp unittest when running under MinGW.
856 ph10 189
857 ph10 197 6. ESC_K was left out of the EBCDIC table.
858 ph10 189
859 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
860     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
861     limit also applies to "virtual nesting" when a pattern is recursive, and in
862     this case 1000 isn't so big. I have been able to remove this limit at the
863     expense of backing off one optimization in certain circumstances. Normally,
864     when pcre_exec() would call its internal match() function recursively and
865     immediately return the result unconditionally, it uses a "tail recursion"
866     feature to save stack. However, when a subpattern that can match an empty
867     string has an unlimited repetition quantifier, it no longer makes this
868     optimization. That gives it a stack frame in which to save the data for
869     checking that an empty string has been matched. Previously this was taken
870     from the 1000-entry workspace that had been reserved. So now there is no
871     explicit limit, but more stack is used.
872 ph10 189
873 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
874     syntax that is required for Windows, and which was going wrong for the
875     pcreposix and pcrecpp parts of the library. These were overlooked when this
876     problem was solved for the main library.
877 ph10 197
878 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
879     the size of patterns that contain repeated groups with explicit upper
880     limits. As the maximum quantifier is 65535, the maximum group length was
881     set at 30,000 so that the product of these two numbers did not overflow a
882     32-bit integer. However, it turns out that people want to use groups that
883     are longer than 30,000 bytes (though not repeat them that many times).
884     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
885     made it possible to implement the integer overflow checks in a much more
886     dynamic way, which I have now done. The artificial limitation on group
887     length has been removed - we now have only the limit on the total length of
888     the compiled pattern, which depends on the LINK_SIZE setting.
889 ph10 208
890     10. Fixed a bug in the documentation for get/copy named substring when
891     duplicate names are permitted. If none of the named substrings are set, the
892     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
893     empty string.
895     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
896     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
897     because the ] is interpreted as the first data character and the
898     terminating ] is not found. PCRE has been made compatible with Perl in this
899     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
900     cause memory overwriting.
902 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
903     string has been matched (to stop an infinite loop). It was not recognizing
904 ph10 208 a conditional subpattern that could match an empty string if that
905 ph10 206 subpattern was within another subpattern. For example, it looped when
906 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
907 ph10 206 condition was not nested. This bug has been fixed.
908 ph10 208
909 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
910     past the start of the subject in the presence of bytes with the top bit
911     set, for example "\x8aBCD".
912 ph10 211
913 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
914     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
915 ph10 200
916 ph10 211 14. Optimized (?!) to (*FAIL).
917 ph10 202
918 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
919     This restricts code points to be within the range 0 to 0x10FFFF, excluding
920     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
921     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
922     does: it's just the validity check that is more restrictive.
923 ph10 220
924     16. Inserted checks for integer overflows during escape sequence (backslash)
925     processing, and also fixed erroneous offset values for syntax errors during
926     backslash processing.
928 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
929 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
931 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
932     caused an overrun.
933 ph10 220
934     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
935     something other than just ASCII characters) inside a group that had an
936     unlimited repeat caused a loop at compile time (while checking to see
937     whether the group could match an empty string).
939 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
940     [\P{Any}] did so. (Error in the code for printing property names.)
941 ph10 210
942 ph10 220 21. An orphan \E inside a character class could cause a crash.
944     22. A repeated capturing bracket such as (A)? could cause a wild memory
945 ph10 218 reference during compilation.
946 ph10 220
947     23. There are several functions in pcre_compile() that scan along a compiled
948     expression for various reasons (e.g. to see if it's fixed length for look
949 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
950 ph10 220 present in the pattern. These operators have additional parameters compared
951     with \d, etc, and these were not being taken into account when moving along
952 ph10 218 the compiled data. Specifically:
953 ph10 220
954     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
955     length.
957     (b) An item such as \pL+ within a repeated group could cause crashes or
958 ph10 218 loops.
959 ph10 220
960 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
961 ph10 220 "reference to non-existent subpattern" error.
963 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
965 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
966 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
967 ph10 211
968 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
969 ph10 218
970 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
971 ph10 223 character were causing crashes (broken optimization).
972 ph10 227
973 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
974 ph10 227 \p or \P) caused a compile-time loop.
976 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
977     break. For example, the unstudied pattern [\r\n]A does not match the string
978     "\r\nA" because change 7.0/46 below moves the current point on by two
979     characters after failing to match at the start. However, the pattern \nA
980 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
981     the same is true. There doesn't seem any very clean way out of this, but
982     what I have chosen to do makes the common cases work: PCRE now takes note
983     of whether there can be an explicit match for \r or \n anywhere in the
984     pattern, and if so, 7.0/46 no longer applies. As part of this change,
985     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
986     pattern has explicit CR or LF references.
987 ph10 222
988 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
989 ph10 223
990 ph10 227
991 ph10 189 Version 7.2 19-Jun-07
992     ---------------------
994 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
995     which is apparently normally available under Windows.
996 ph10 159
997     2. Re-jig the pcregrep tests with different newline settings in an attempt
998     to make them independent of the local environment's newline setting.
999 ph10 157
1000 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1001 ph10 165
1002 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1003     was not 2, because the output contained actual offsets. The recent new
1004 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1005     usable with all link sizes.
1007 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1008     stack recursion. This gives a massive performance boost under BSD, but just
1009 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1010 ph10 164 in all cases.
1011 ph10 172
1012 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1013 ph10 172
1014 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1015     recursion call. It refers to the nth most recently opened parentheses.
1016 ph10 172
1017 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1018 ph10 172 to be opened parentheses.
1020     (c) Conditions that refer to capturing parentheses can be specified
1021 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1022 ph10 172
1023 ph10 168 (d) \K resets the start of the current match so that everything before
1024 ph10 172 is not part of it.
1026 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1027 ph10 172
1028 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1029 ph10 172 reference syntax.
1030 ph10 182
1031 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1032 ph10 182 alternative starts with the same number.
1033 ph10 172
1034 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1036 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1039     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1040     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1041 ph10 170 for detecting groups that can match an empty string.
1042 ph10 159
1043 ph10 172 9. A pattern with a very large number of alternatives (more than several
1044     hundred) was running out of internal workspace during the pre-compile
1045     phase, where pcre_compile() figures out how much memory will be needed. A
1046     bit of new cunning has reduced the workspace needed for groups with
1047     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1048     workspace instead of running out of the 4096 that are available.
1049 ph10 182
1050 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1051 ph10 172
1052 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1053     The report of the bug said:
1054 ph10 182
1055 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1056     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1057 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1058 ph10 185
1059 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1060 ph10 185 it matched the wrong number of bytes.
1061 ph10 172
1062 ph10 179
1063 ph10 155 Version 7.1 24-Apr-07
1064 ph10 98 ---------------------
1066 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1067 ph10 122 that is more "standard", making use of automake and other Autotools. There
1068 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1069     on this.
1070 ph10 111
1071     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1072     for recursive directory scanning broke on some systems because the files
1073     are not scanned in any specific order and on different systems the order
1074     was different. A call to "sort" has been inserted into RunGrepTest for the
1075     approprate test as a short-term fix. In the longer term there may be an
1076 ph10 100 alternative.
1077 ph10 111
1078 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1079 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1080     people do their own conversions for various reasons). The problems
1081     concerned the use of low-level troff macros .br and .in. I have therefore
1082     removed all such uses from the man pages (some were redundant, some could
1083 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1084     HTML has been updated to handle .nf/.fi and to complain if it encounters
1085     .br or .in.
1086 ph10 111
1087 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1088 ph10 123 arranged for config.h to be included in the distribution, with the name
1089 ph10 111 config.h.generic, for the benefit of those who have to compile without
1090     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1092     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1093     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1094 ph10 127 makevp.bat for the current PCRE, using the additional files
1095 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1096 ph10 111
1097     6. A Windows user reported a minor discrepancy with test 2, which turned out
1098     to be caused by a trailing space on an input line that had got lost in his
1099 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1100 ph10 111
1101 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1102 ph10 111 that is needed.
1104 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1105     as "const" (a) because they are and (b) because it helps the PHP
1106     maintainers who have recently made a script to detect big data structures
1107 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1108     to update Builducptable as well, so it won't revert if ucptable.h is ever
1109 ph10 105 re-created.
1110 ph10 111
1111     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1112 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1113 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1114     support is not required. This saves 1.5-2K of code, which is important in
1115 ph10 107 some applications.
1116 ph10 111
1117 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1118 ph10 111 so as not to refer to the tables, even though these functions will never be
1119     called when UTF-8 support is disabled. Otherwise there are problems with a
1120     shared library.
1122 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1124     (a) It was defining its arguments as char * instead of void *.
1126 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1127     a long time ago when I wrote it, but is no longer the case.
1129 ph10 118 The emulated memove() is provided for those environments that have neither
1130 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1131 ph10 118 is clearly not the case, as these two bugs were recently reported.
1132 ph10 123
1133 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1134 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1135     pages, and it removes trailing spaces from listed files. It also creates
1136     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1137     case, it wraps all the #defines with #ifndefs. This script should be run
1138 ph10 111 before "make dist".
1139 ph10 123
1140 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1141     with Unicode property support.
1142 ph10 123
1143     (a) For a maximizing quantifier, if the two different cases of the
1144     character were of different lengths in their UTF-8 codings (there are
1145     some cases like this - I found 11), and the matching function had to
1146 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1147     were both the same length.
1148 ph10 123
1149     (b) When PCRE was configured to use the heap rather than the stack for
1150     recursion during matching, it was not correctly preserving the data for
1151     the other case of a UTF-8 character when checking ahead for a match
1152     while processing a minimizing repeat. If the check also involved
1153 ph10 115 matching a wide character, but failed, corruption could cause an
1154     erroneous result when trying to check for a repeat of the original
1155     character.
1156 ph10 123
1157 ph10 116 13. Some tidying changes to the testing mechanism:
1158 ph10 98
1159 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1160     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1161 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1162     this for UTF-8.) The configure.ac script no longer substitutes the
1163     relevant variables.
1165 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1166     with length and offset values. This means that the output is different
1167     for different internal link sizes. Test 2 is skipped for link sizes
1168     other than 2 because of this, bypassing the problem. Unfortunately,
1169     there was also a test in test 3 (the locale tests) that used /B and
1170 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1171     I have added a new /Z option to pcretest that replaces the length and
1172     offset values with spaces. This is now used to make test 3 independent
1173 ph10 122 of link size. (Test 2 will be tidied up later.)
1174 ph10 123
1175     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1176 ph10 122 segmentation fault instead of returning the appropriate error message.
1177 ph10 134
1178 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1179 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1180     This doesn't seem right; it now treats the CRLF combination as the line
1181     ending, and so does not match in that case. It's only a pattern such as ^$
1182     that would hit this one: something like ^ABC$ would have failed after \r
1183     and then tried again after \r\n.
1185 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1186 ph10 134 in an attempt to make files that differ only in their line terminators
1187     compare equal. This works on Linux.
1188 ph10 142
1189 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1190     as it exited. This is now fixed, thanks to valgrind.
1191 ph10 142
1192 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1193 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1194     was because its rules for how to advance for /g after matching an empty
1195 ph10 143 string at the end of a line did not allow for this case. They now check for
1196     it specially.
1197 ph10 150
1198     20. pcretest is supposed to handle patterns and data of any length, by
1199     extending its buffers when necessary. It was getting this wrong when the
1200 ph10 147 buffer for a data line had to be extended.
1201 ph10 150
1202 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1203 ph10 150 CRLF as a newline sequence.
1204 ph10 152
1205 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1206 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1207     I have nevertheless tidied it up.
1208 ph10 111
1209 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1210 ph10 123
1211 ph10 153 24. Added a man page for pcre-config.
1212 ph10 152
1213 ph10 153
1214 nigel 93 Version 7.0 19-Dec-06
1215     ---------------------
1217     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1218     moving to gcc 4.1.1.
1220     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1221     sys/time.h, which is documented as needed for this function. It doesn't
1222     seem to matter on Linux, but it showed up on some releases of OS X.
1224     3. It seems that there are systems where bytes whose values are greater than
1225     127 match isprint() in the "C" locale. The "C" locale should be the
1226     default when a C program starts up. In most systems, only ASCII printing
1227     characters match isprint(). This difference caused the output from pcretest
1228     to vary, making some of the tests fail. I have changed pcretest so that:
1230     (a) When it is outputting text in the compiled version of a pattern, bytes
1231     other than 32-126 are always shown as hex escapes.
1233     (b) When it is outputting text that is a matched part of a subject string,
1234     it does the same, unless a different locale has been set for the match
1235     (using the /L modifier). In this case, it uses isprint() to decide.
1237     4. Fixed a major bug that caused incorrect computation of the amount of memory
1238     required for a compiled pattern when options that changed within the
1239     pattern affected the logic of the preliminary scan that determines the
1240     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1241     that the computed length was too small. The symptoms of this bug were
1242     either the PCRE error "internal error: code overflow" from pcre_compile(),
1243     or a glibc crash with a message such as "pcretest: free(): invalid next
1244     size (fast)". Examples of patterns that provoked this bug (shown in
1245     pcretest format) are:
1247     /(?-x: )/x
1248     /(?x)(?-x: \s*#\s*)/
1249     /((?i)[\x{c0}])/8
1250     /(?i:[\x{c0}])/8
1252     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1253     is now done differently.
1255     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1256     wrapper classes; (b) implement a new function in the C++ scanner that is
1257     more efficient than the old way of doing things because it avoids levels of
1258     recursion in the regex matching; (c) add a paragraph to the documentation
1259     for the FullMatch() function.
1261     6. The escape sequence \n was being treated as whatever was defined as
1262     "newline". Not only was this contrary to the documentation, which states
1263     that \n is character 10 (hex 0A), but it also went horribly wrong when
1264     "newline" was defined as CRLF. This has been fixed.
1266     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1267     was being set to -1 for the "end of line" case (supposedly a value that no
1268     character can have). Though this value is never used (the check for end of
1269     line is "zero bytes in current character"), it caused compiler complaints.
1270     I've changed it to 0xffffffff.
1272     8. In pcre_version.c, the version string was being built by a sequence of
1273     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1274     string (as it is for production releases) called a macro with an empty
1275     argument. The C standard says the result of this is undefined. The gcc
1276     compiler treats it as an empty string (which was what was wanted) but it is
1277     reported that Visual C gives an error. The source has been hacked around to
1278     avoid this problem.
1280     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1281     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1282     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1283     of them did).
1285     10. Originally, pcretest opened its input and output without "b"; then I was
1286     told that "b" was needed in some environments, so it was added for release
1287     5.0 to both the input and output. (It makes no difference on Unix-like
1288     systems.) Later I was told that it is wrong for the input on Windows. I've
1289     now abstracted the modes into two macros, to make it easier to fiddle with
1290     them, and removed "b" from the input mode under Windows.
1292     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1294     12. Added -help and --help to pcretest as an official way of being reminded
1295     of the options.
1297     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1298     and pcrecpp.cc because they annoy compilers at high warning levels.
1300     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1302     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1303     scripts are not C programs :-) and which was not noticed because it works
1304     on Linux.
1306     16. pcretest is supposed to handle any length of pattern and data line (as one
1307     line or as a continued sequence of lines) by extending its input buffer if
1308     necessary. This feature was broken for very long pattern lines, leading to
1309     a string of junk being passed to pcre_compile() if the pattern was longer
1310     than about 50K.
1312     17. I have done a major re-factoring of the way pcre_compile() computes the
1313     amount of memory needed for a compiled pattern. Previously, there was code
1314     that made a preliminary scan of the pattern in order to do this. That was
1315     OK when PCRE was new, but as the facilities have expanded, it has become
1316     harder and harder to keep it in step with the real compile phase, and there
1317     have been a number of bugs (see for example, 4 above). I have now found a
1318     cunning way of running the real compile function in a "fake" mode that
1319     enables it to compute how much memory it would need, while actually only
1320     ever using a few hundred bytes of working memory and without too many
1321     tests of the mode. This should make future maintenance and development
1322     easier. A side effect of this work is that the limit of 200 on the nesting
1323     depth of parentheses has been removed (though this was never a serious
1324     limitation, I suspect). However, there is a downside: pcre_compile() now
1325     runs more slowly than before (30% or more, depending on the pattern). I
1326     hope this isn't a big issue. There is no effect on runtime performance.
1328     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1329     newline (only possible for the last line of a file) and it was a
1330     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1332     19. Added additional timing features to pcretest. (1) The -tm option now times
1333     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1334     separate command line item, by a number that specifies the number of
1335     repeats to use when timing. The default is 50000; this gives better
1336     precision, but takes uncomfortably long for very large patterns.
1338     20. Extended pcre_study() to be more clever in cases where a branch of a
1339     subpattern has no definite first character. For example, (a*|b*)[cd] would
1340     previously give no result from pcre_study(). Now it recognizes that the
1341     first character must be a, b, c, or d.
1343     21. There was an incorrect error "recursive call could loop indefinitely" if
1344     a subpattern (or the entire pattern) that was being tested for matching an
1345     empty string contained only one non-empty item after a nested subpattern.
1346     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1347     incorrectly, because the \d was being skipped in the check.
1349     22. The pcretest program now has a new pattern option /B and a command line
1350     option -b, which is equivalent to adding /B to every pattern. This causes
1351     it to show the compiled bytecode, without the additional information that
1352     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1353     is the same as /B/I).
1355     23. A new optimization is now able automatically to treat some sequences such
1356     as a*b as a*+b. More specifically, if something simple (such as a character
1357     or a simple class like \d) has an unlimited quantifier, and is followed by
1358     something that cannot possibly match the quantified thing, the quantifier
1359     is automatically "possessified".
1361     24. A recursive reference to a subpattern whose number was greater than 39
1362     went wrong under certain circumstances in UTF-8 mode. This bug could also
1363     have affected the operation of pcre_study().
1365     25. Realized that a little bit of performance could be had by replacing
1366     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1368     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1370     27. Possessive quantifiers such as a++ were previously implemented by turning
1371     them into atomic groups such as ($>a+). Now they have their own opcodes,
1372     which improves performance. This includes the automatically created ones
1373     from 23 above.
1375     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1376     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1377     the first matched character to be a colon. This applied both to named and
1378     numbered groups.
1380     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1382     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1383     building PCRE on Windows easier, so I have included it in the distribution.
1385     31. There is now a check in pcretest against a ridiculously large number being
1386     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1387     loop, the loop is abandoned.
1389     32. Forward references to subpatterns in conditions such as (?(2)...) where
1390     subpattern 2 is defined later cause pcre_compile() to search forwards in
1391     the pattern for the relevant set of parentheses. This search went wrong
1392     when there were unescaped parentheses in a character class, parentheses
1393     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1395     33. "Subroutine" calls and backreferences were previously restricted to
1396     referencing subpatterns earlier in the regex. This restriction has now
1397     been removed.
1399     34. Added a number of extra features that are going to be in Perl 5.10. On the
1400     whole, these are just syntactic alternatives for features that PCRE had
1401     previously implemented using the Python syntax or my own invention. The
1402     other formats are all retained for compatibility.
1404     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1405     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1406     also .NET compatible.
1408     (b) A recursion or subroutine call to a named group can now be defined as
1409     (?&name) as well as (?P>name).
1411     (c) A backreference to a named group can now be defined as \k<name> or
1412     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1413     5.10, are also .NET compatible.
1415     (d) A conditional reference to a named group can now use the syntax
1416     (?(<name>) or (?('name') as well as (?(name).
1418     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1419     groups (named and numbered) that are never evaluated inline, but can be
1420     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1421     is always false. There may be only one alternative in such a group.
1423     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1424     as the simple (?(R). The condition is true only if the most recent
1425     recursion is that of the given number or name. It does not search out
1426     through the entire recursion stack.
1428     (g) The escape \gN or \g{N} has been added, where N is a positive or
1429     negative number, specifying an absolute or relative reference.
1431     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1432     some "unreachable code" warnings.
1434     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1435     things, this adds five new scripts.
1437     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1438     There were also incompatibilities regarding the handling of \Q..\E inside
1439     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1440     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1442     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1443     matches an empty string, and forcibly breaks the loop. There were bugs in
1444     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1445     against aaaa the result was just "a" rather than "aaaa", for example. Two
1446     separate and independent bugs (that affected different cases) have been
1447     fixed.
1449     39. Refactored the code to abolish the use of different opcodes for small
1450     capturing bracket numbers. This is a tidy that I avoided doing when I
1451     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1452     The new approach is not only tidier, it makes it possible to reduce the
1453     memory needed to fix the previous bug (38).
1455     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1456     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1457     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1458     mode.
1460     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1461     report.
1463     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1464     copy construction and assignment in the C++ wrapper.
1466     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1467     couple of bugs that could have given wrong results in the "--newline=crlf"
1468     case.
1470     44. Added a number of casts and did some reorganization of signed/unsigned int
1471     variables following suggestions from Dair Grant. Also renamed the variable
1472     "this" as "item" because it is a C++ keyword.
1474     45. Arranged for dftables to add
1476     #include "pcre_internal.h"
1478     to pcre_chartables.c because without it, gcc 4.x may remove the array
1479     definition from the final binary if PCRE is built into a static library and
1480     dead code stripping is activated.
1482     46. For an unanchored pattern, if a match attempt fails at the start of a
1483     newline sequence, and the newline setting is CRLF or ANY, and the next two
1484     characters are CRLF, advance by two characters instead of one.
1487 nigel 91 Version 6.7 04-Jul-06
1488     ---------------------
1490     1. In order to handle tests when input lines are enormously long, pcretest has
1491     been re-factored so that it automatically extends its buffers when
1492     necessary. The code is crude, but this _is_ just a test program. The
1493     default size has been increased from 32K to 50K.
1495     2. The code in pcre_study() was using the value of the re argument before
1496     testing it for NULL. (Of course, in any sensible call of the function, it
1497     won't be NULL.)
1499     3. The memmove() emulation function in pcre_internal.h, which is used on
1500     systems that lack both memmove() and bcopy() - that is, hardly ever -
1501     was missing a "static" storage class specifier.
1503     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1504     containing an extended class (one that cannot be represented by a bitmap
1505     because it contains high-valued characters or Unicode property items, e.g.
1506     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1507     pattern, but PCRE should not loop if you do not (it no longer does).
1508     [Detail: two cases were found: (a) a repeated subpattern containing an
1509     extended class; (b) a recursive reference to a subpattern that followed a
1510     previous extended class. It wasn't skipping over the extended class
1511     correctly when UTF-8 mode was not set.]
1513     5. A negated single-character class was not being recognized as fixed-length
1514     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1515     compile error "lookbehind assertion is not fixed length".
1517     6. The RunPerlTest auxiliary script was showing an unexpected difference
1518     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1519     write a Perl script that can interpret lines of an input file either as
1520     byte characters or as UTF-8, which is what "perltest" was being required to
1521     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1522     can't do is switch easily at run time between having the "use utf8;" pragma
1523     or not. In the end, I fudged it by using the RunPerlTest script to insert
1524     "use utf8;" explicitly for the UTF-8 tests.
1526     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1527     the end of the subject string, contrary to the documentation and to what
1528     Perl does. This was true of both matching functions. Now it matches only at
1529     the start of the subject and immediately after *internal* newlines.
1531     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1532     a pointer to an int instead of a pointer to an unsigned long int. This
1533     caused problems on 64-bit systems.
1535     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1536     instance of the 'standard' template library not being so standard".
1538     10. There was no check on the number of named subpatterns nor the maximum
1539     length of a subpattern name. The product of these values is used to compute
1540     the size of the memory block for a compiled pattern. By supplying a very
1541     long subpattern name and a large number of named subpatterns, the size
1542     computation could be caused to overflow. This is now prevented by limiting
1543     the length of names to 32 characters, and the number of named subpatterns
1544     to 10,000.
1546     11. Subpatterns that are repeated with specific counts have to be replicated in
1547     the compiled pattern. The size of memory for this was computed from the
1548     length of the subpattern and the repeat count. The latter is limited to
1549     65535, but there was no limit on the former, meaning that integer overflow
1550     could in principle occur. The compiled length of a repeated subpattern is
1551     now limited to 30,000 bytes in order to prevent this.
1553     12. Added the optional facility to have named substrings with the same name.
1555     13. Added the ability to use a named substring as a condition, using the
1556     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1557     are numbers (not recommended). Forward references are permitted.
1559     14. Added forward references in named backreferences (if you see what I mean).
1561     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1562     pattern could run off the end of the subject. For example, the pattern
1563     "(?s)(.{1,5})"8 did this with the subject "ab".
1565     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1566     PCRE_CASELESS was set when matching characters that were quantified with ?
1567     or *.
1569     17. A character class other than a single negated character that had a minimum
1570     but no maximum quantifier - for example [ab]{6,} - was not handled
1571     correctly by pce_dfa_exec(). It would match only one character.
1573     18. A valid (though odd) pattern that looked like a POSIX character
1574     class but used an invalid character after [ (for example [[,abc,]]) caused
1575     pcre_compile() to give the error "Failed: internal error: code overflow" or
1576     in some cases to crash with a glibc free() error. This could even happen if
1577     the pattern terminated after [[ but there just happened to be a sequence of
1578     letters, a binary zero, and a closing ] in the memory that followed.
1580     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1581     over the years. Originally (before any Unicode support), just the bottom 8
1582     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1583     output from "man perlunicode" includes this:
1585     The regular expression compiler produces polymorphic opcodes. That
1586     is, the pattern adapts to the data and automatically switches to
1587     the Unicode character scheme when presented with Unicode data--or
1588     instead uses a traditional byte scheme when presented with byte
1589     data.
1591     Sadly, a wide octal escape does not cause a switch, and in a string with
1592     no other multibyte characters, these octal escapes are treated as before.
1593     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1594     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1595     Unicode string.
1597     I have not perpetrated such confusion in PCRE. Up till now, it took just
1598     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1599     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1600     translate to the appropriate multibyte character.
1602     29. Applied some refactoring to reduce the number of warnings from Microsoft
1603     and Borland compilers. This has included removing the fudge introduced
1604     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1605     a warning about an unused variable.
1607     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1608     characters since release 4.0, because Perl (from release 5.004) does not.
1609     [Or at least, is documented not to: some releases seem to be in conflict
1610     with the documentation.] However, when a pattern was studied with
1611     pcre_study() and all its branches started with \s, PCRE still included VT
1612     as a possible starting character. Of course, this did no harm; it just
1613     caused an unnecessary match attempt.
1615     22. Removed a now-redundant internal flag bit that recorded the fact that case
1616     dependency changed within the pattern. This was once needed for "required
1617     byte" processing, but is no longer used. This recovers a now-scarce options
1618     bit. Also moved the least significant internal flag bit to the most-
1619     significant bit of the word, which was not previously used (hangover from
1620     the days when it was an int rather than a uint) to free up another bit for
1621     the future.
1623     23. Added support for CRLF line endings as well as CR and LF. As well as the
1624     default being selectable at build time, it can now be changed at runtime
1625     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1626     specify that it is scanning data with non-default line endings.
1628     24. Changed the definition of CXXLINK to make it agree with the definition of
1629     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1631     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1632     recursions. This makes a big different to stack usage for some patterns.
1634     26. If a subpattern containing a named recursion or subroutine reference such
1635     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1636     the space required for the compiled pattern went wrong and gave too small a
1637     value. Depending on the environment, this could lead to "Failed: internal
1638     error: code overflow at offset 49" or "glibc detected double free or
1639     corruption" errors.
1641     27. Applied patches from Google (a) to support the new newline modes and (b) to
1642     advance over multibyte UTF-8 characters in GlobalReplace.
1644     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1645     difference for some implementation of PCRE in some Windows version.
1647     29. Added some extra testing facilities to pcretest:
1649     \q<number> in a data line sets the "match limit" value
1650     \Q<number> in a data line sets the "match recursion limt" value
1651     -S <number> sets the stack size, where <number> is in megabytes
1653     The -S option isn't available for Windows.
1656 nigel 89 Version 6.6 06-Feb-06
1657     ---------------------
1659     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1660     in pcreposix.h. I have copied the definition from pcre.h.
1662     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1663     because pcre.h is no longer a built file.
1665     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1666     not normally included in the compiled code.
1669 nigel 87 Version 6.5 01-Feb-06
1670     ---------------------
1672     1. When using the partial match feature with pcre_dfa_exec(), it was not
1673     anchoring the second and subsequent partial matches at the new starting
1674     point. This could lead to incorrect results. For example, with the pattern
1675     /1234/, partially matching against "123" and then "a4" gave a match.
1677     2. Changes to pcregrep:
1679     (a) All non-match returns from pcre_exec() were being treated as failures
1680     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1681     error message is output. Some extra information is given for the
1683     probably the only errors that are likely to be caused by users (by
1684     specifying a regex that has nested indefinite repeats, for instance).
1685     If there are more than 20 of these errors, pcregrep is abandoned.
1687     (b) A binary zero was treated as data while matching, but terminated the
1688     output line if it was written out. This has been fixed: binary zeroes
1689     are now no different to any other data bytes.
1691     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1692     used to set a locale for matching. The --locale=xxxx long option has
1693     been added (no short equivalent) to specify a locale explicitly on the
1694     pcregrep command, overriding the environment variables.
1696     (d) When -B was used with -n, some line numbers in the output were one less
1697     than they should have been.
1699     (e) Added the -o (--only-matching) option.
1701     (f) If -A or -C was used with -c (count only), some lines of context were
1702     accidentally printed for the final match.
1704     (g) Added the -H (--with-filename) option.
1706     (h) The combination of options -rh failed to suppress file names for files
1707     that were found from directory arguments.
1709     (i) Added the -D (--devices) and -d (--directories) options.
1711     (j) Added the -F (--fixed-strings) option.
1713     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1715     (l) Added the --colo(u)r option.
1717     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1718     is not present by default.
1720     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1721     items such as (?R) or (?1), when the recursion could match a number of
1722     alternatives. If it matched one of the alternatives, but subsequently,
1723     outside the recursion, there was a failure, the code tried to back up into
1724     the recursion. However, because of the way PCRE is implemented, this is not
1725     possible, and the result was an incorrect result from the match.
1727     In order to prevent this happening, the specification of recursion has
1728     been changed so that all such subpatterns are automatically treated as
1729     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1731     4. I had overlooked the fact that, in some locales, there are characters for
1732     which isalpha() is true but neither isupper() nor islower() are true. In
1733     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1734     and ordfeminine) are like this. This affected the treatment of \w and \W
1735     when they appeared in character classes, but not when they appeared outside
1736     a character class. The bit map for "word" characters is now created
1737     separately from the results of isalnum() instead of just taking it from the
1738     upper, lower, and digit maps. (Plus the underscore character, of course.)
1740     5. The above bug also affected the handling of POSIX character classes such as
1741     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1742     permanent tables. Instead, the bit maps for such a class were previously
1743     created as the appropriate unions of the upper, lower, and digit bitmaps.
1744     Now they are created by subtraction from the [[:word:]] class, which has
1745     its own bitmap.
1747     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1748     It is created by subtracting the vertical space characters (\x09, \x0a,
1749     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1750     subtraction was done in the overall bitmap for a character class, meaning
1751     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1752     be recognized. This bug has been fixed.
1754     7. Patches from the folks at Google:
1756     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1757     real life, but is still worth protecting against".
1759     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1760     regular expressions".
1762     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1763     have it.
1765     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1766     "configure" and the latter not, in order to fix a problem somebody had
1767     with compiling the Arg class on HP-UX.
1769     (e) Improve the error-handling of the C++ wrapper a little bit.
1771     (f) New tests for checking recursion limiting.
1773     8. The pcre_memmove() function, which is used only if the environment does not
1774     have a standard memmove() function (and is therefore rarely compiled),
1775     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1776     returning a result (though PCRE never actually uses the result).
1778     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1779     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1780     returned instead of calling malloc() with an overflowing number that would
1781     most likely cause subsequent chaos.
1783     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1785     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1786     with this option is matched, the nmatch and pmatch options of regexec() are
1787     ignored.
1789     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1790     provided in case anyone wants to the the POSIX interface with UTF-8
1791     strings.
1793     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1794     C++ linking (needed for some HP-UX environments).
1796     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1797     (unused parameter) and in the pcre_printint() function (omitted "default"
1798     switch label when the default is to do nothing).
1800     15. Added some code to make it possible, when PCRE is compiled as a C++
1801     library, to replace subject pointers for pcre_exec() with a smart pointer
1802     class, thus making it possible to process discontinuous strings.
1804     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1805     much the same function. They were added by different people who were trying
1806     to make PCRE easy to compile on non-Unix systems. It has been suggested
1807     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1808     for compiling on Windows systems. I have therefore replaced it with
1809     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1810     defaults to "extern" for C or "extern C" for C++, which works fine on
1811     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1812     SCOPE with something explicit in config.h. In addition:
1814     (a) pcreposix.h still had just "extern" instead of either of these macros;
1815     I have replaced it with PCRE_DATA_SCOPE.
1817     (b) Functions such as _pcre_xclass(), which are internal to the library,
1818     but external in the C sense, all had PCRE_EXPORT in their definitions.
1819     This is apparently wrong for the Windows case, so I have removed it.
1820     (It makes no difference on Unix-like systems.)
1822     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1823     of recursive calls to match(). This is different to MATCH_LIMIT because
1824     that limits the total number of calls to match(), not all of which increase
1825     the depth of recursion. Limiting the recursion depth limits the amount of
1826     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1827     when PCRE is compiled, and changed at run time. A patch from Google adds
1828     this functionality to the C++ interface.
1830     18. Changes to the handling of Unicode character properties:
1832     (a) Updated the table to Unicode 4.1.0.
1834     (b) Recognize characters that are not in the table as "Cn" (undefined).
1836     (c) I revised the way the table is implemented to a much improved format
1837     which includes recognition of ranges. It now supports the ranges that
1838     are defined in UnicodeData.txt, and it also amalgamates other
1839     characters into ranges. This has reduced the number of entries in the
1840     table from around 16,000 to around 3,000, thus reducing its size
1841     considerably. I realized I did not need to use a tree structure after
1842     all - a binary chop search is just as efficient. Having reduced the
1843     number of entries, I extended their size from 6 bytes to 8 bytes to
1844     allow for more data.
1846     (d) Added support for Unicode script names via properties such as \p{Han}.
1848     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1849     matching that character.
1851     20. When matching a repeated Unicode property with a minimum greater than zero,
1852     (for example \pL{2,}), PCRE could look past the end of the subject if it
1853     reached it while seeking the minimum number of characters. This could
1854     happen only if some of the characters were more than one byte long, because
1855     there is a check for at least the minimum number of bytes.
1857     21. Refactored the implementation of \p and \P so as to be more general, to
1858     allow for more different types of property in future. This has changed the
1859     compiled form incompatibly. Anybody with saved compiled patterns that use
1860     \p or \P will have to recompile them.
1862     22. Added "Any" and "L&" to the supported property types.
1864     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1865     but give a compile time error if the value is greater than 0xff.
1867     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1868     accidentally not being installed or uninstalled.
1870     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1871     made were to insert the current release number. This seemed silly, because
1872     it made things harder for people building PCRE on systems that don't run
1873     "configure". I have turned pcre.h into a distributed file, no longer built
1874     by "configure", with the version identification directly included. There is
1875     no longer a pcre.h.in file.
1877     However, this change necessitated a change to the pcre-config script as
1878     well. It is built from pcre-config.in, and one of the substitutions was the
1879     release number. I have updated configure.ac so that ./configure now finds
1880     the release number by grepping pcre.h.
1882     26. Added the ability to run the tests under valgrind.
1885 nigel 85 Version 6.4 05-Sep-05
1886     ---------------------
1888     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1889     "--" to be printed when multiple files were scanned, even when none of the
1890     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1891     consider it to be a bug, and have restored the previous behaviour.
1893     2. A couple of code tidies to get rid of compiler warnings.
1895     3. The pcretest program used to cheat by referring to symbols in the library
1896     whose names begin with _pcre_. These are internal symbols that are not
1897     really supposed to be visible externally, and in some environments it is
1898     possible to suppress them. The cheating is now confined to including
1899     certain files from the library's source, which is a bit cleaner.
1901     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1902     file's purpose clearer.
1904     5. Reorganized pcre_ucp_findchar().
1907 nigel 83 Version 6.3 15-Aug-05
1908     ---------------------
1910     1. The file libpcre.pc.in did not have general read permission in the tarball.
1912     2. There were some problems when building without C++ support:
1914     (a) If C++ support was not built, "make install" and "make test" still
1915     tried to test it.
1917     (b) There were problems when the value of CXX was explicitly set. Some
1918     changes have been made to try to fix these, and ...
1920     (c) --disable-cpp can now be used to explicitly disable C++ support.
1922     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1923     backslash in a target when C++ was disabled. This confuses some
1924     versions of "make", apparently. Using an intermediate variable solves
1925     this. (Same for CPP_LOBJ.)
1927     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1928     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1929     necessary on certain architectures.
1931     4. Added a setting of -export-symbols-regex to the link command to remove
1932     those symbols that are exported in the C sense, but actually are local
1933     within the library, and not documented. Their names all begin with
1934     "_pcre_". This is not a perfect job, because (a) we have to except some
1935     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1936     available (and never for static libraries). I have made a note to try to
1937     find a way round (a) in the future.
1940 nigel 81 Version 6.2 01-Aug-05
1941     ---------------------
1943     1. There was no test for integer overflow of quantifier values. A construction
1944     such as {1111111111111111} would give undefined results. What is worse, if
1945     a minimum quantifier for a parenthesized subpattern overflowed and became
1946     negative, the calculation of the memory size went wrong. This could have
1947     led to memory overwriting.
1949     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1951     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1952     operating environments where this matters.
1954     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1955     PCRE options from within the C++ wrapper.
1957     5. Named capturing subpatterns were not being correctly counted when a pattern
1958     was compiled. This caused two problems: (a) If there were more than 100
1959     such subpatterns, the calculation of the memory needed for the whole
1960     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1961     back references of the form \12, where the number was greater than 9, were
1962     not recognized as back references, even though there were sufficient
1963     previous subpatterns.
1965     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1966     versions of gcc, e.g. 2.95.4.
1969 nigel 79 Version 6.1 21-Jun-05
1970     ---------------------
1972     1. There was one reference to the variable "posix" in pcretest.c that was not
1973     surrounded by "#if !defined NOPOSIX".
1975     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1976     the cross-check on the old pcre_info() function, for the benefit of the
1977     cut-down version of PCRE that is currently imported into Exim.
1979     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1980     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1981     patterns that start (?i) but I don't think that matters. The use of (?i) is
1982     just an example; this all applies to the other options as well.
1984     4. Since libtool seems to echo the compile commands it is issuing, the output
1985     from "make" can be reduced a bit by putting "@" in front of each libtool
1986     compile command.
1988     5. Patch from the folks at Google for configure.in to be a bit more thorough
1989     in checking for a suitable C++ installation before trying to compile the
1990     C++ stuff. This should fix a reported problem when a compiler was present,
1991     but no suitable headers.
1993     6. The man pages all had just "PCRE" as their title. I have changed them to
1994     be the relevant file name. I have also arranged that these names are
1995     retained in the file doc/pcre.txt, which is a concatenation in text format
1996     of all the man pages except the little individual ones for each function.
1998     7. The NON-UNIX-USE file had not been updated for the different set of source
1999     files that come with release 6. I also added a few comments about the C++
2000     wrapper.
2003 nigel 77 Version 6.0 07-Jun-05
2004     ---------------------
2006     1. Some minor internal re-organization to help with my DFA experiments.
2008     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2009     didn't matter for the library itself when fully configured, but did matter
2010     when compiling without UCP support, or within Exim, where the ucp files are
2011     not imported.
2013     3. Refactoring of the library code to split up the various functions into
2014     different source modules. The addition of the new DFA matching code (see
2015     below) to a single monolithic source would have made it really too
2016     unwieldy, quite apart from causing all the code to be include in a
2017     statically linked application, when only some functions are used. This is
2018     relevant even without the DFA addition now that patterns can be compiled in
2019     one application and matched in another.
2021     The downside of splitting up is that there have to be some external
2022     functions and data tables that are used internally in different modules of
2023     the library but which are not part of the API. These have all had their
2024     names changed to start with "_pcre_" so that they are unlikely to clash
2025     with other external names.
2027     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2028     a different (DFA) algorithm. Although it is slower than the original
2029     function, it does have some advantages for certain types of matching
2030     problem.
2032     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2033     including restarting after a partial match.
2035     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2036     defined when compiling for Windows was sent to me. I have put it into the
2037     code, though I have no means of testing or verifying it.
2039     7. Added the pcre_refcount() auxiliary function.
2041     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2042     match before or at the first newline in the subject string. In pcretest,
2043     the /f option on a pattern can be used to set this.
2045     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2046     would behave wrongly. This has been present in PCRE since release 4.0.
2048     10. A number of changes to the pcregrep command:
2050     (a) Refactored how -x works; insert ^(...)$ instead of setting
2051     PCRE_ANCHORED and checking the length, in preparation for adding
2052     something similar for -w.
2054     (b) Added the -w (match as a word) option.
2056     (c) Refactored the way lines are read and buffered so as to have more
2057     than one at a time available.
2059     (d) Implemented a pcregrep test script.
2061     (e) Added the -M (multiline match) option. This allows patterns to match
2062     over several lines of the subject. The buffering ensures that at least
2063     8K, or the rest of the document (whichever is the shorter) is available
2064     for matching (and similarly the previous 8K for lookbehind assertions).
2066     (f) Changed the --help output so that it now says
2068     -w, --word-regex(p)
2070     instead of two lines, one with "regex" and the other with "regexp"
2071     because that confused at least one person since the short forms are the
2072     same. (This required a bit of code, as the output is generated
2073     automatically from a table. It wasn't just a text change.)
2075     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2076     option but starts with a hyphen. Could be a pattern or a path name
2077     starting with a hyphen, for instance.
2079     (h) "-" can be given as a file name to represent stdin.
2081     (i) When file names are being printed, "(standard input)" is used for
2082     the standard input, for compatibility with GNU grep. Previously
2083     "<stdin>" was used.
2085     (j) The option --label=xxx can be used to supply a name to be used for
2086     stdin when file names are being printed. There is no short form.
2088     (k) Re-factored the options decoding logic because we are going to add
2089     two more options that take data. Such options can now be given in four
2090     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2092     (l) Added the -A, -B, and -C options for requesting that lines of context
2093     around matches be printed.
2095     (m) Added the -L option to print the names of files that do not contain
2096     any matching lines, that is, the complement of -l.
2098     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2099     continue to scan other files.
2101     (o) The -s option was incorrectly implemented. For compatibility with other
2102     greps, it now suppresses the error message for a non-existent or non-
2103     accessible file (but not the return code). There is a new option called
2104     -q that suppresses the output of matching lines, which was what -s was
2105     previously doing.
2107     (p) Added --include and --exclude options to specify files for inclusion
2108     and exclusion when recursing.
2110     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2111     Hopefully, it now does.
2113     12. Missing cast in pcre_study().
2115     13. Added an "uninstall" target to the makefile.
2117     14. Replaced "extern" in the function prototypes in Makefile.in with
2118     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2119     world, but is set differently for Windows.
2121     15. Added a second compiling function called pcre_compile2(). The only
2122     difference is that it has an extra argument, which is a pointer to an
2123     integer error code. When there is a compile-time failure, this is set
2124     non-zero, in addition to the error test pointer being set to point to an
2125     error message. The new argument may be NULL if no error number is required
2126     (but then you may as well call pcre_compile(), which is now just a
2127     wrapper). This facility is provided because some applications need a
2128     numeric error indication, but it has also enabled me to tidy up the way
2129     compile-time errors are handled in the POSIX wrapper.
2131     16. Added VPATH=.libs to the makefile; this should help when building with one
2132     prefix path and installing with another. (Or so I'm told by someone who
2133     knows more about this stuff than I do.)
2135     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2136     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2137     match everything, including newlines. This is not POSIX-compatible, but
2138     somebody wanted the feature. From pcretest it can be activated by using
2139     both the P and the s flags.
2141     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2143     19. libpcre.pc was being incorrectly installed as executable.
2145     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2146     it now also looks for '\r' so that it will work unmodified on Windows.
2148     21. Added Google's contributed C++ wrapper to the distribution.
2150     22. Added some untidy missing memory free() calls in pcretest, to keep
2151     Electric Fence happy when testing.
2155 nigel 75 Version 5.0 13-Sep-04
2156     ---------------------
2158     1. Internal change: literal characters are no longer packed up into items
2159     containing multiple characters in a single byte-string. Each character
2160     is now matched using a separate opcode. However, there may be more than one
2161     byte in the character in UTF-8 mode.
2163     2. The pcre_callout_block structure has two new fields: pattern_position and
2164     next_item_length. These contain the offset in the pattern to the next match
2165     item, and its length, respectively.
2167     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2168     insertion of callouts before each pattern item. Added the /C option to
2169     pcretest to make use of this.
2171     4. On the advice of a Windows user, the lines
2173     #if defined(_WIN32) || defined(WIN32)
2174     _setmode( _fileno( stdout ), 0x8000 );
2175     #endif /* defined(_WIN32) || defined(WIN32) */
2177     have been added to the source of pcretest. This apparently does useful
2178     magic in relation to line terminators.
2180     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2181     for the benefit of those environments where the "b" makes a difference.
2183     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2184     to know about it. I have put a hack into configure.in that adds in code
2185     to set GCC=yes if CC=icc. This seems to end up at a point in the
2186     generated configure script that is early enough to affect the setting of
2187     compiler options, which is what is needed, but I have no means of testing
2188     whether it really works. (The user who reported this had patched the
2189     generated configure script, which of course I cannot do.)
2191     LATER: After change 22 below (new libtool files), the configure script
2192     seems to know about icc (and also ecc). Therefore, I have commented out
2193     this hack in configure.in.
2195     7. Added support for pkg-config (2 patches were sent in).
2197     8. Negated POSIX character classes that used a combination of internal tables
2198     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2199     [[:^ascii]]. Typically, they would match almost any characters. The other
2200     POSIX classes were not broken in this way.
2202     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2203     to find the match, as PCRE was deluded into thinking that the match had to
2204     start at the start point or following a newline. The same bug applied to
2205     patterns with negative forward assertions or any backward assertions
2206     preceding ".*" at the start, unless the pattern required a fixed first
2207     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2209     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2210     starting at the last subject character, bytes beyond the end of the subject
2211     string were read.
2213     11. Renamed the variable "class" as "classbits" to make life easier for C++
2214     users. (Previously there was a macro definition, but it apparently wasn't
2215     enough.)
2217     12. Added the new field "tables" to the extra data so that tables can be passed
2218     in at exec time, or the internal tables can be re-selected. This allows
2219     a compiled regex to be saved and re-used at a later time by a different
2220     program that might have everything at different addresses.
2222     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2223     -R library as well as a -L library.
2225     14. The debugging options of pcretest (-d on the command line or D on a
2226     pattern) showed incorrect output for anything following an extended class
2227     that contained multibyte characters and which was followed by a quantifier.
2229     15. Added optional support for general category Unicode character properties
2230     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2231     support. It adds about 90K to the size of the library. The meanings of the
2232     inbuilt class escapes such as \d and \s have NOT been changed.
2234     16. Updated pcredemo.c to include calls to free() to release the memory for the
2235     compiled pattern.
2237     17. The generated file chartables.c was being created in the source directory
2238     instead of in the building directory. This caused the build to fail if the
2239     source directory was different from the building directory, and was
2240     read-only.
2242     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2243     file. No doubt somebody will tell me if they don't make sense... Also added
2244     Dan Mooney's comments about building on OpenVMS.
2246     19. Added support for partial matching via the PCRE_PARTIAL option for
2247     pcre_exec() and the \P data escape in pcretest.
2249     20. Extended pcretest with 3 new pattern features:
2251     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2252     write the compiled pattern to the file whose name is "rest-of-line".
2253     This is a straight binary dump of the data, with the saved pointer to
2254     the character tables forced to be NULL. The study data, if any, is
2255     written too. After writing, pcretest reads a new pattern.
2257     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2258     compiled pattern from the given file. There must not be any
2259     occurrences of "<" in the file name (pretty unlikely); if there are,
2260     pcretest will instead treat the initial "<" as a pattern delimiter.
2261     After reading in the pattern, pcretest goes on to read data lines as
2262     usual.
2264     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2265     and 16-bit fields in a compiled pattern, to simulate a pattern that
2266     was compiled on a host of opposite endianness.
2268     21. The pcre-exec() function can now cope with patterns that were compiled on
2269     hosts of opposite endianness, with this restriction:
2271     As for any compiled expression that is saved and used later, the tables
2272     pointer field cannot be preserved; the extra_data field in the arguments
2273     to pcre_exec() should be used to pass in a tables address if a value
2274     other than the default internal tables were used at compile time.
2276     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2277     now diagnosed as an error. Previously, most of the time, a negative number
2278     would have been treated as zero, but if in addition "ovector" was passed as
2279     NULL, a crash could occur.
2281     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2282     new versions from the libtool 1.5 distribution (the last one is a copy of
2283     a file called libtool.m4). This seems to have fixed the need to patch
2284     "configure" to support Darwin 1.3 (which I used to do). However, I still
2285     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2286     workstation).
2288     24. Changed the PCRE licence to be the more standard "BSD" licence.
2291 nigel 73 Version 4.5 01-Dec-03
2292     ---------------------
2294     1. There has been some re-arrangement of the code for the match() function so
2295     that it can be compiled in a version that does not call itself recursively.
2296     Instead, it keeps those local variables that need separate instances for
2297     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2298     needs to "recurse". Keeping track of where control must go is done by means
2299     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2300     hide most of the details from the main code, and operates only if
2301     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2302     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2303     operating.
2305     To make it easier for callers to provide specially tailored get/free
2306     functions for this usage, two new functions, pcre_stack_malloc, and
2307     pcre_stack_free, are used. They are always called in strict stacking order,
2308     and the size of block requested is always the same.
2310     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2311     PCRE has been compiled to use the stack or the heap for recursion. The
2312     -C option of pcretest uses this to show which version is compiled.
2314     A new data escape \S, is added to pcretest; it causes the amounts of store
2315     obtained and freed by both kinds of malloc/free at match time to be added
2316     to the output.
2318     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2319     what's available on my current Linux desktop machine.
2321     3. When matching a UTF-8 string, the test for a valid string at the start has
2322     been extended. If start_offset is not zero, PCRE now checks that it points
2323     to a byte that is the start of a UTF-8 character. If not, it returns
2324     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2325     this is necessary because there may be backward assertions in the pattern.
2326     When matching the same subject several times, it may save resources to use
2327     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2329     4. The code for checking the validity of UTF-8 strings has been tightened so
2330     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2331     containing "overlong sequences".
2333     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2334     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2335     should have been "&", but it just so happened that all the cases this let
2336     through by mistake were picked up later in the function.
2338     6. I had used a variable called "isblank" - this is a C99 function, causing
2339     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2341     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2342     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2343     so the version is shown; (c) stop "make test" echoing "./RunTest".
2345     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2347     9. The prototype for memmove() for systems that don't have it was using
2348     size_t, but the inclusion of the header that defines size_t was later. I've
2349     moved the #includes for the C headers earlier to avoid this.
2351     10. Added some adjustments to the code to make it easier to compiler on certain
2352     special systems:
2354     (a) Some "const" qualifiers were missing.
2355     (b) Added the macro EXPORT before all exported functions; by default this
2356     is defined to be empty.
2357     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2358     that it reads its output file name as an argument instead of writing
2359     to the standard output and assuming this can be redirected.
2361     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2362     class containing characters with values greater than 255, PCRE compilation
2363     went into a loop.
2365     12. A recursive reference to a subpattern that was within another subpattern
2366     that had a minimum quantifier of zero caused PCRE to crash. For example,
2367     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2368     recursion. If the recursively-called subpattern itself had a zero repeat,
2369     that was OK.
2371     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2372     buffer into which it was copied (for escape processing) was still set at
2373     1024, so long lines caused crashes.
2375     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2376     "internal error: code overflow...". This applied to any character class
2377     that was followed by a possessive quantifier.
2379     15. Modified the Makefile to add libpcre.la as a prerequisite for
2380     libpcreposix.la because I was told this is needed for a parallel build to
2381     work.
2383     16. If a pattern that contained .* following optional items at the start was
2384     studied, the wrong optimizing data was generated, leading to matching
2385     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2386     matching string must start with a or b or c. The correct conclusion for
2387     this pattern is that a match can start with any character.
2390 nigel 71 Version 4.4 13-Aug-03
2391     ---------------------
2393     1. In UTF-8 mode, a character class containing characters with values between
2394     127 and 255 was not handled correctly if the compiled pattern was studied.
2395     In fixing this, I have also improved the studying algorithm for such
2396     classes (slightly).
2398     2. Three internal functions had redundant arguments passed to them. Removal
2399     might give a very teeny performance improvement.
2401     3. Documentation bug: the value of the capture_top field in a callout is *one
2402     more than* the number of the hightest numbered captured substring.
2404     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2405     in incorrectly linking with a previously installed version. They now link
2406     explicitly with libpcre.la.
2408     5. configure.in no longer needs to recognize Cygwin specially.
2410     6. A problem in pcre.in for Windows platforms is fixed.
2412     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2413     pcretest, it used to include the size of the study block as part of its
2414     output. Unfortunately, the structure contains a field that has a different
2415     size on different hardware architectures. This meant that the tests that
2416     showed this size failed. As the block is currently always of a fixed size,
2417     this information isn't actually particularly useful in pcretest output, so
2418     I have just removed it.
2420     8. Three pre-processor statements accidentally did not start in column 1.
2421     Sadly, there are *still* compilers around that complain, even though
2422     standard C has not required this for well over a decade. Sigh.
2424     9. In pcretest, the code for checking callouts passed small integers in the
2425     callout_data field, which is a void * field. However, some picky compilers
2426     complained about the casts involved for this on 64-bit systems. Now
2427     pcretest passes the address of the small integer instead, which should get
2428     rid of the warnings.
2430     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2431     both compile and run time, and gives an error if an invalid UTF-8 sequence
2432     is found. There is a option for disabling this check in cases where the
2433     string is known to be correct and/or the maximum performance is wanted.
2435     11. In response to a bug report, I changed one line in Makefile.in from
2437     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2438     to
2439     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2441     to look similar to other lines, but I have no way of telling whether this
2442     is the right thing to do, as I do not use Windows. No doubt I'll get told
2443     if it's wrong...
2446 nigel 69 Version 4.3 21-May-03
2447     ---------------------
2449     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2450     Makefile.
2452     2. Some refactoring to improve the quality of the code:
2454     (i) The utf8_table... variables are now declared "const".
2456     (ii) The code for \cx, which used the "case flipping" table to upper case
2457     lower case letters, now just substracts 32. This is ASCII-specific,
2458     but the whole concept of \cx is ASCII-specific, so it seems
2459     reasonable.
2461     (iii) PCRE was using its character types table to recognize decimal and
2462     hexadecimal digits in the pattern. This is silly, because it handles
2463     only 0-9, a-f, and A-F, but the character types table is locale-
2464     specific, which means strange things might happen. A private
2465     table is now used for this - though it costs 256 bytes, a table is
2466     much faster than multiple explicit tests. Of course, the standard
2467     character types table is still used for matching digits in subject
2468     strings against \d.
2470     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2471     ending in _t are). So I've renamed it as ESC_tee.
2473     3. The first argument for regexec() in the POSIX wrapper should have been
2474     defined as "const".
2476     4. Changed pcretest to use malloc() for its buffers so that they can be
2477     Electric Fenced for debugging.
2479     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2480     to read one or more bytes before the start of the subject string. Often this
2481     had no effect on PCRE's behaviour, but in some circumstances it could
2482     provoke a segmentation fault.
2484     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2485     to try to read one or more bytes before the start of the subject string.
2487     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2488     UTF-8 support could misbehave in various ways if the subject string
2489     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2490     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2491     back over UTF-8 characters.)
2494 nigel 67 Version 4.2 14-Apr-03
2495     ---------------------
2497     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2499     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2500     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2501     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2502     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2503     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2504     and BUILD_EXEEXT
2505     Note: automatic setting of the BUILD variables is not yet working
2506     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2507     compile-time but not at link-time
2508     [LINK]: use for linking executables only
2509     make different versions for Windows and non-Windows
2510     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2511     libraries
2512     [LINK_FOR_BUILD]: new variable
2513     [OBJEXT]: use throughout
2514     [EXEEXT]: use throughout
2515     <winshared>: new target
2516     <wininstall>: new target
2517     <dftables.o>: use native compiler
2518     <dftables>: use native linker
2519     <install>: handle Windows platform correctly
2520     <clean>: ditto
2521     <check>: ditto
2522     copy DLL to top builddir before testing
2524     As part of these changes, -no-undefined was removed again. This was reported
2525     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2526     in any case.
2528     3. Some tidies to get rid of compiler warnings:
2530     . In the match_data structure, match_limit was an unsigned long int, whereas
2531     match_call_count was an int. I've made them both unsigned long ints.
2533     . In pcretest the fact that a const uschar * doesn't automatically cast to
2534     a void * provoked a warning.
2536     . Turning on some more compiler warnings threw up some "shadow" variables
2537     and a few more missing casts.
2539     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2540     option, a class that contained a single character with a value between 128
2541     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2543     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2544     option, a class that contained several characters, but with at least one
2545     whose value was between 128 and 255 caused PCRE to crash.
2548 nigel 65 Version 4.1 12-Mar-03
2549     ---------------------
2550 nigel 63
2551 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2552     needed, and a string in dftables.c that was longer than standard compilers are
2553     required to support.
2555     2. Compiling with Sun's compiler found a few more places where the code could
2556     be tidied up in order to avoid warnings.
2558     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2559     first of these names is deprecated in the latest Autoconf in favour of the name
2560     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2561     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2562     analogy I have changed it to CFLAGS_FOR_BUILD.
2564     4. Added -no-undefined to the linking command in the Makefile, because this is
2565     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2566     linking step for the pcreposix library.
2568     5. PCRE was failing to diagnose the case of two named groups with the same
2569     name.
2571     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2572     literal character that is needed in the subject for a match, and scans along to
2573     ensure that it is present before embarking on the full matching process. This
2574     saves time in cases of nested unlimited repeats that are never going to match.
2575     Problem: the scan can take a lot of time if the subject is very long (e.g.
2576     megabytes), thus penalizing straightforward matches. It is now done only if the
2577     amount of subject to be scanned is less than 1000 bytes.
2579     7. A lesser problem with the same optimization is that it was recording the
2580     first character of an anchored pattern as "needed", thus provoking a search
2581     right along the subject, even when the first match of the pattern was going to
2582     fail. The "needed" character is now not set for anchored patterns, unless it
2583     follows something in the pattern that is of non-fixed length. Thus, it still
2584     fulfils its original purpose of finding quick non-matches in cases of nested
2585     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2588     Version 4.0 17-Feb-03
2589     ---------------------
2591 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2592     extended to the end of string, PCRE compiled incorrect data. This could lead to
2593     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2595     2. Moved to autoconf 2.53 and libtool 1.4.2.
2597     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2598     the special perltest8 script is no longer needed - all the tests can be run
2599     from a single perltest script.
2601     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2602     by \s. It has now been removed in PCRE. This means it isn't recognized as
2603     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2604     class [:space:] *does* include VT, thereby creating a mess.
2606     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2607     space and tab.
2609     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2610     its new features into the main test script, reducing the number of scripts.
2612     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2613     were backward compatible, and made the (?i) apply to the whole pattern, as if
2614     /i were given. Now it behaves more logically, and applies the option setting
2615     only to what follows. PCRE has been changed to follow suit. However, if it
2616     finds options settings right at the start of the pattern, it extracts them into
2617     the global options, as before. Thus, they show up in the info data.
2619     8. Added support for the \Q...\E escape sequence. Characters in between are
2620     treated as literals. This is slightly different from Perl in that $ and @ are
2621     also handled as literals inside the quotes. In Perl, they will cause variable
2622     interpolation. Note the following examples:
2624     Pattern PCRE matches Perl matches
2626     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2627     \Qabc\$xyz\E abc\$xyz abc\$xyz
2628     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2630     For compatibility with Perl, \Q...\E sequences are recognized inside character
2631     classes as well as outside them.
2633     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2634     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2635     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2636     signed/unsigned warnings.
2638     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2639     option for pcretest, so I've replaced it by a simple function that does just
2640     that job.
2642     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2643     "pcregrep -".
2645     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2646     Java package. This provides some syntactic sugar for simple cases of what my
2647     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2648     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2649     item, you can use this simplified notation. Note that only makes sense with
2650     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2651     greediness, whatever the setting of the PCRE_UNGREEDY option.
2653     13. A change of greediness default within a pattern was not taking effect at
2654     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2655     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2656     was abstracted outside.
2658     14. PCRE now supports the \G assertion. It is true when the current matching
2659     position is at the start point of the match. This differs from \A when the
2660     starting offset is non-zero. Used with the /g option of pcretest (or similar
2661     code), it works in the same way as it does for Perl's /g option. If all
2662     alternatives of a regex begin with \G, the expression is anchored to the start
2663     match position, and the "anchored" flag is set in the compiled expression.
2665     15. Some bugs concerning the handling of certain option changes within patterns
2666     have been fixed. These applied to options other than (?ims). For example,
2667     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2668     been the other way round. Some of this was related to change 7 above.
2670     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2671     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2672     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2673     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2675     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2676     mode. Unlike ".", it always matches newline, whatever the setting of
2677     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2678     assertions. Perl allows it, but it doesn't (in general) work because it can't
2679     calculate the length of the lookbehind. At least, that's the case for Perl
2680     5.8.0 - I've been told they are going to document that it doesn't work in
2681     future.
2683     18. Added an error diagnosis for escapes that PCRE does not support: these are
2684     \L, \l, \N, \P, \p, \U, \u, and \X.
2686     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2687     reading past the end of the pattern in cases such as /[abcd/.
2689     20. PCRE was getting more memory than necessary for patterns with classes that
2690     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2692     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2693     compiling PCRE for use with Virtual Pascal.
2695     22. Small fix to the Makefile to make it work properly if the build is done
2696     outside the source tree.
2698     23. Added a new extension: a condition to go with recursion. If a conditional
2699     subpattern starts with (?(R) the "true" branch is used if recursion has
2700     happened, whereas the "false" branch is used only at the top level.
2702     24. When there was a very long string of literal characters (over 255 bytes
2703     without UTF support, over 250 bytes with UTF support), the computation of how
2704     much memory was required could be incorrect, leading to segfaults or other
2705     strange effects.
2707     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2708     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2709     there was a subsequent back reference to those brackets. This meant that, for
2710     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2711     possible to check for precisely this case. All we can do is abandon the
2712     optimization if .* occurs inside capturing brackets when there are any back
2713     references whatsoever. (See below for a better fix that came later.)
2715     26. The handling of the optimization for finding the first character of a
2716     non-anchored pattern, and for finding a character that is required later in the
2717     match were failing in some cases. This didn't break the matching; it just
2718     failed to optimize when it could. The way this is done has been re-implemented.
2720     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2722     28. Added a new feature that provides some of the functionality that Perl
2723     provides with (?{...}). The facility is termed a "callout". The way it is done
2724     in PCRE is for the caller to provide an optional function, by setting
2725     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2726     global variable. By default it is unset, which disables all calling out. To get
2727     the function called, the regex must include (?C) at appropriate points. This
2728     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2729     This provides a means of identifying different callout points. When PCRE
2730     reaches such a point in the regex, if pcre_callout has been set, the external
2731     function is called. It is provided with data in a structure called
2732     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2733     matching continues; if it returns a non-zero value, the match at the current
2734     point fails. However, backtracking will occur if possible. [This was changed
2735     later and other features added - see item 49 below.]
2737     29. pcretest is upgraded to test the callout functionality. It provides a
2738     callout function that displays information. By default, it shows the start of
2739     the match and the current position in the text. There are some new data escapes
2740     to vary what happens:
2742     \C+ in addition, show current contents of captured substrings
2743     \C- do not supply a callout function
2744     \C!n return 1 when callout number n is reached
2745     \C!n!m return 1 when callout number n is reached for the mth time
2747     30. If pcregrep was called with the -l option and just a single file name, it
2748     output "<stdin>" if a match was found, instead of the file name.
2750     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2751     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2752     pcre_exec(). This saves a malloc/free per call. The default value of
2753     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2754     when configuring.
2756     32. The default maximum size of a compiled pattern is 64K. There have been a
2757     few cases of people hitting this limit. The code now uses macros to handle the
2758     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2759     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2760     configuring. Tests 2 and 5 work only with 2-byte links because they output
2761     debugging information about compiled patterns.
2763     33. Internal code re-arrangements:
2765     (a) Moved the debugging function for printing out a compiled regex into
2766     its own source file (printint.c) and used #include to pull it into
2767     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2768     separate copies.
2770     (b) Defined the list of op-code names for debugging as a macro in
2771     internal.h so that it is next to the definition of the opcodes.
2773     (c) Defined a table of op-code lengths for simpler skipping along compiled
2774     code. This is again a macro in internal.h so that it is next to the
2775     definition of the opcodes.
2777     34. Added support for recursive calls to individual subpatterns, along the
2778     lines of Robin Houston's patch (but implemented somewhat differently).
2780     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2781     allow it to read and process whole directories in Win32. This code was
2782     contributed by Lionel Fourquaux; it has not been tested by me.
2784     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2785     used to name a group. Names consist of alphanumerics and underscores, and must
2786     be unique. Back references use the syntax (?P=name) and recursive calls use
2787     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2788     numbers. The function pcre_fullinfo() can be used after compilation to extract
2789     a name/number map. There are three relevant calls:
2791     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2792     PCRE_INFO_NAMECOUNT yields the number of entries
2793     PCRE_INFO_NAMETABLE yields a pointer to the map.
2795     The map is a vector of fixed-size entries. The size of each entry depends on
2796     the length of the longest name used. The first two bytes of each entry are the
2797     group number, most significant byte first. There follows the corresponding
2798     name, zero terminated. The names are in alphabetical order.
2800     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2801     case instead of 255. Making it the same both with and without UTF-8 support
2802     means that the same test output works with both.
2804     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2805     calling malloc() with a zero argument.
2807     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2808     optimization. I've improved things by keeping a bitmap of backreferences with
2809     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2810     fact referenced, the optimization can be applied. It is unlikely that a
2811     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2812     the match to follow \n) will appear inside brackets with a number greater than
2813     31, but if it does, any back reference > 31 suppresses the optimization.
2815     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2816     of disabling numbered capturing parentheses. Any opening parenthesis that is
2817     not followed by ? behaves as if it were followed by ?: but named parentheses
2818     can still be used for capturing (and they will acquire numbers in the usual
2819     way).
2821     41. Redesigned the return codes from the match() function into yes/no/error so
2822     that errors can be passed back from deep inside the nested calls. A malloc
2823     failure while inside a recursive subpattern call now causes the
2824     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2826     42. It is now possible to set a limit on the number of times the match()
2827     function is called in a call to pcre_exec(). This facility makes it possible to
2828     limit the amount of recursion and backtracking, though not in a directly
2829     obvious way, because the match() function is used in a number of different
2830     circumstances. The count starts from zero for each position in the subject
2831     string (for non-anchored patterns). The default limit is, for compatibility, a
2832     large number, namely 10 000 000. You can change this in two ways:
2834     (a) When configuring PCRE before making, you can use --with-match-limit=n
2835     to set a default value for the compiled library.
2837     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2838     a different value is set. See 45 below.
2840     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2842     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2843     of things that can be changed at compile time. The first argument specifies
2844     what is wanted and the second points to where the information is to be placed.
2845     The current list of available information is:
2849     The output is an integer that is set to one if UTF-8 support is available;
2850     otherwise it is set to zero.
2854     The output is an integer that it set to the value of the code that is used for
2855     newline. It is either LF (10) or CR (13).
2859     The output is an integer that contains the number of bytes used for internal
2860     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2864     The output is an integer that contains the threshold above which the POSIX
2865     interface uses malloc() for output vectors. See item 31 above.
2869     The output is an unsigned integer that contains the default limit of the number
2870     of match() calls in a pcre_exec() execution. See 42 above.
2872     44. pcretest has been upgraded by the addition of the -C option. This causes it
2873     to extract all the available output from the new pcre_config() function, and to
2874     output it. The program then exits immediately.
2876     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2877     order to support additional features. One way would have been to define
2878     pcre_exec2() (for example) with extra arguments, but this would not have been
2879     extensible, and would also have required all calls to the original function to
2880     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2881     is used for passing in "extra" data from pcre_study().
2883     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2884     contains the following fields:
2886     flags a bitmap indicating which of the following fields are set
2887     study_data opaque data from pcre_study()
2888     match_limit a way of specifying a limit on match() calls for a specific
2889     call to pcre_exec()
2890     callout_data data for callouts (see 49 below)
2892     The flag bits are also defined in pcre.h, and are
2898     The pcre_study() function now returns one of these new pcre_extra blocks, with
2899     the actual study data pointed to by the study_data field, and the
2900     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2901     before. That is, this change is entirely upwards-compatible and requires no
2902     change to existing code.
2904     If you want to pass in additional data to pcre_exec(), you can either place it
2905     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2906     block.
2908     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2909     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2910     times with different match limits, until it finds the minimum value needed for
2911     pcre_exec() to complete. The value is then output. This can be instructive; for
2912     most simple matches the number is quite small, but for pathological cases it
2913     gets very large very quickly.
2915     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2916     returns the size of the data block pointed to by the study_data field in a
2917     pcre_extra block, that is, the value that was passed as the argument to
2918     pcre_malloc() when PCRE was getting memory in which to place the information
2919     created by pcre_study(). The fourth argument should point to a size_t variable.
2920     pcretest has been extended so that this information is shown after a successful
2921     pcre_study() call when information about the compiled regex is being displayed.
2923     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2924     because what follows is always an absolute path. (Later: it turns out that this
2925     is more than cosmetic for MinGW, because it doesn't like empty path
2926     components.)
2928     49. Some changes have been made to the callout feature (see 28 above):
2930     (i) A callout function now has three choices for what it returns:
2932     0 => success, carry on matching
2933     > 0 => failure at this point, but backtrack if possible
2934     < 0 => serious error, return this value from pcre_exec()
2936     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2937     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2938     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2939     use by callout functions. It will never be used by PCRE itself.
2941     (ii) The pcre_extra structure (see 45 above) has a void * field called
2942     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2943     pcre_callout_block structure has a field of the same name. The contents of
2944     the field passed in the pcre_extra structure are passed to the callout
2945     function in the corresponding field in the callout block. This makes it
2946     easier to use the same callout-containing regex from multiple threads. For
2947     testing, the pcretest program has a new data escape
2949     \C*n pass the number n (may be negative) as callout_data
2951     If the callout function in pcretest receives a non-zero value as
2952     callout_data, it returns that value.
2954     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2955     there were some redundant $(CFLAGS) in commands that are now specified as
2956     $(LINK), which already includes $(CFLAGS).
2958     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2959     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2960     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2961     one-byte characters throughout. Note that case-insensitive matching applies
2962     only to characters whose values are less than 256. PCRE doesn't support the
2963     notion of cases for higher-valued characters.
2965     (i) A character class whose characters are all within 0-255 is handled as
2966     a bit map, and the map is inverted for negative classes. Previously, a
2967     character > 255 always failed to match such a class; however it should
2968     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2970     (ii) A negated character class with a single character < 255 is coded as
2971     "not this character" (OP_NOT). This wasn't working properly when the test
2972     character was multibyte, either singly or repeated.
2974     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2975     mode, for example: \x{100}{2,3}.
2977     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2978     singly or repeated) now correctly test multibyte characters. However,
2979     PCRE doesn't recognize any characters with values greater than 255 as
2980     digits, spaces, or word characters. Such characters always match \D, \S,
2981     and \W, and never match \d, \s, or \w.
2983     (v) Classes may now contain characters and character ranges with values
2984     greater than 255. For example: [ab\x{100}-\x{400}].
2986     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2987     PCRE in UTF-8 mode.
2989     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2990     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2991     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2992     value.)
2994     53. The single man page has become too large. I have therefore split it up into
2995     a number of separate man pages. These also give rise to individual HTML pages;
2996     these are now put in a separate directory, and there is an index.html page that
2997     lists them all. Some hyperlinking between the pages has been installed.
2999     54. Added convenience functions for handling named capturing parentheses.
3001     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3002     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3003     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3004     are faulted.
3006     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3007     calling configure. These values are used when compiling the dftables.c program
3008     which is run to generate the source of the default character tables. They
3009     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3010     you will need to set these values.
3012     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3015     Version 3.9 02-Jan-02
3016 nigel 61 ---------------------
3018     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3020     2. If --disable-static was given, the building process failed when trying to
3021     build pcretest and pcregrep. (For some reason it was using libtool to compile
3022     them, which is not right, as they aren't part of the library.)
3025 nigel 59 Version 3.8 18-Dec-01
3026     ---------------------
3028     1. The experimental UTF-8 code was completely screwed up. It was packing the
3029     bytes in the wrong order. How dumb can you get?
3032 nigel 57 Version 3.7 29-Oct-01
3033     ---------------------
3035     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3036     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3037     this didn't happen under Solaris 8, where I normally test things.
3039 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3040     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3041     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3042     this fix an hour or so after the initial 3.7 release.)
3043 nigel 57
3044 nigel 59
3045 nigel 55 Version 3.6 23-Oct-01
3046     ---------------------
3048     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3049     offsets passed as NULL with zero offset count.
3051     2. The config.guess and config.sub files had not been updated when I moved to
3052     the latest autoconf.
3055 nigel 53 Version 3.5 15-Aug-01
3056     ---------------------
3057 nigel 5
3058 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3059     had been forgotten.
3061     2. By using declared but undefined structures, we can avoid using "void"
3062     definitions in pcre.h while keeping the internal definitions of the structures
3063     private.
3065     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3066     user point of view, this means that both static and shared libraries are built
3067     by default, but this can be individually controlled. More of the work of
3068     handling this static/shared cases is now inside libtool instead of PCRE's make
3069     file.
3071     4. The pcretest utility is now installed along with pcregrep because it is
3072     useful for users (to test regexs) and by doing this, it automatically gets
3073     relinked by libtool. The documentation has been turned into a man page, so
3074     there are now .1, .txt, and .html versions in /doc.
3076     5. Upgrades to pcregrep:
3077     (i) Added long-form option names like gnu grep.
3078     (ii) Added --help to list all options with an explanatory phrase.
3079     (iii) Added -r, --recursive to recurse into sub-directories.
3080     (iv) Added -f, --file to read patterns from a file.
3082     6. pcre_exec() was referring to its "code" argument before testing that
3083     argument for NULL (and giving an error if it was NULL).
3085     7. Upgraded Makefile.in to allow for compiling in a different directory from
3086     the source directory.
3088     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3089     options bits, the pointer it was passed was to an int instead of to an unsigned
3090     long int. This mattered only on 64-bit systems.
3092     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3093     generated) instead of pcre.in, which it its source. Also made the same change
3094     in several of the .c files.
3096     10. A new release of gcc defines printf() as a macro, which broke pcretest
3097     because it had an ifdef in the middle of a string argument for printf(). Fixed
3098     by using separate calls to printf().
3100     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3101     script, to force use of CR or LF instead of \n in the source. On non-Unix
3102     systems, the value can be set in config.h.
3104     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3105     absolute limit. Changed the text of the error message to make this clear, and
3106     likewise updated the man page.
3108     13. The limit of 99 on the number of capturing subpatterns has been removed.
3109     The new limit is 65535, which I hope will not be a "real" limit.
3112 nigel 51 Version 3.4 22-Aug-00
3113     ---------------------
3115     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3117     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3120 nigel 49 Version 3.3 01-Aug-00
3121     ---------------------
3123     1. If an octal character was given, but the value was greater than \377, it
3124     was not getting masked to the least significant bits, as documented. This could
3125     lead to crashes in some systems.
3127     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3128     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3130     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3131     These just pass their arguments on to (pcre_free)(), but they are provided
3132     because some uses of PCRE bind it to non-C systems that can call its functions,
3133     but cannot call free() or pcre_free() directly.
3135     4. Add "make test" as a synonym for "make check". Corrected some comments in
3136     the Makefile.
3138     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3139     Makefile.
3141     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3142     command called pgrep for grepping around the active processes.
3144     7. Added the beginnings of support for UTF-8 character strings.
3146     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3147     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3148     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3149     out for the ar command.)
3152 nigel 47 Version 3.2 12-May-00
3153     ---------------------
3155     This is purely a bug fixing release.
3157     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3158     of ZA. This was just one example of several cases that could provoke this bug,
3159     which was introduced by change 9 of version 2.00. The code for breaking
3160     infinite loops after an iteration that matches an empty string was't working
3161     correctly.
3163     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3164     when matched against abbab (for example). After matching an empty string, it
3165     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3166     caused it to match further down the string than it should.
3168     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3169     was there because it doesn't seem to be needed, and it causes trouble on some
3170     systems, as it is not a Standard C header. It has been removed.
3172     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3173     were reported on the Macintosh. The changes were from
3175     while ((c = *(++ptr)) != 0 && c != '\n');
3176     to
3177     while ((c = *(++ptr)) != 0 && c != '\n') ;
3179     Totally extraordinary, but if that's what it takes...
3181     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3182     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3183     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3184     assumes the way PCRE uses memmove() (always moving upwards).
3186     6. PCRE is being used in one environment where strchr() is not available. There
3187     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3188     faster code anyway.
3191 nigel 45 Version 3.1 09-Feb-00
3192     ---------------------
3194     The only change in this release is the fixing of some bugs in Makefile.in for
3195     the "install" target:
3197     (1) It was failing to install pcreposix.h.
3199     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3202 nigel 43 Version 3.0 01-Feb-00
3203     ---------------------
3204 nigel 41
3205     1. Add support for the /+ modifier to perltest (to output $` like it does in
3206     pcretest).
3208     2. Add support for the /g modifier to perltest.
3210     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3211     matches null strings.
3213     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3214     pattern. Perl treats empty patterns specially - it reuses the most recent
3215     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3216     effect.
3218     5. The POSIX interface was broken in that it was just handing over the POSIX
3219     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3220     required a bigger vector, with some working space on the end. This means that
3221     the POSIX wrapper now has to get and free some memory, and copy the results.
3223 nigel 43 6. Added some simple autoconf support, placing the test data and the
3224     documentation in separate directories, re-organizing some of the
3225     information files, and making it build pcre-config (a GNU standard). Also added
3226     libtool support for building PCRE as a shared library, which is now the
3227     default.
3228 nigel 41
3229 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3230     09 are not valid octal constants. Single digits will be used for minor values
3231     less than 10.
3233     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3234     existing programs that set these in the POSIX interface can use PCRE without
3235     modification.
3237     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3238     return all that pcre_info() returns, plus additional data. The pcre_info()
3239     function is retained for compatibility, but is considered to be obsolete.
3241     10. Added experimental recursion feature (?R) to handle one common case that
3242     Perl 5.6 will be able to do with (?p{...}).
3244     11. Added support for POSIX character classes like [:alpha:], which Perl is
3245     adopting.
3248 nigel 39 Version 2.08 31-Aug-99
3249     ----------------------
3251     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3252     trying to match at the startoffset position, but instead was moving forward to
3253     the next newline as if a previous match had failed.
3255     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3256     and could get into a loop if a null string was matched other than at the start
3257     of the subject.
3259     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3260     be distinguished at compile time, and for completeness also added PCRE_DATE.
3262     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3263     in GnuWin32 environments.
3266 nigel 37 Version 2.07 29-Jul-99
3267     ----------------------
3269     1. The documentation is now supplied in plain text form and HTML as well as in
3270     the form of man page sources.
3272     2. C++ compilers don't like assigning (void *) values to other pointer types.
3273     In particular this affects malloc(). Although there is no problem in Standard
3274     C, I've put in casts to keep C++ compilers happy.
3276     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3277     should be (const char *).
3279     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3280     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3281     However, I haven't made this a standard facility. The documentation doesn't
3282     mention it, and the Makefile doesn't support it.
3284     5. The Makefile now contains an "install" target, with editable destinations at
3285     the top of the file. The pcretest program is not installed.
3287     6. pgrep -V now gives the PCRE version number and date.
3289     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3290     causing the entire string to be ignored, instead of just the last character.
3292     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3293     non-matching string, it can take a very, very long time, even for strings of
3294     quite modest length, because of the nested recursion. PCRE now does better in
3295     some of these cases. It does this by remembering the last required literal
3296     character in the pattern, and pre-searching the subject to ensure it is present
3297     before running the real match. In other words, it applies a heuristic to detect
3298     some types of certain failure quickly, and in the above example, if presented
3299     with a string that has no trailing " it gives "no match" very quickly.
3301     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3302     other alternatives are tried instead.
3305 nigel 35 Version 2.06 09-Jun-99
3306     ----------------------
3308     1. Change pcretest's output for amount of store used to show just the code
3309     space, because the remainder (the data block) varies in size between 32-bit and
3310     64-bit systems.
3312     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3313     start matching at. This allows lookbehinds to work when searching for multiple
3314     occurrences in a string.
3316     3. Added additional options to pcretest for testing multiple occurrences:
3318     /+ outputs the rest of the string that follows a match
3319     /g loops for multiple occurrences, using the new startoffset argument
3320     /G loops for multiple occurrences by passing an incremented pointer
3322     4. PCRE wasn't doing the "first character" optimization for patterns starting
3323     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3324     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3325     the letter 'x'. On long subject strings, this gives a significant speed-up.
3328 nigel 33 Version 2.05 21-Apr-99
3329     ----------------------
3331     1. Changed the type of magic_number from int to long int so that it works
3332     properly on 16-bit systems.
3334     2. Fixed a bug which caused patterns starting with .* not to work correctly
3335     when the subject string contained newline characters. PCRE was assuming
3336     anchoring for such patterns in all cases, which is not correct because .* will
3337     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3338     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3339     must be retried after every newline in the subject.
3342 nigel 31 Version 2.04 18-Feb-99
3343     ----------------------
3345     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3346     computation of the store needed to hold the pattern was incorrect (too large).
3347     If such patterns were nested a few deep, this could multiply and become a real
3348     problem.
3350     2. Added /M option to pcretest to show the memory requirement of a specific
3351     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3353     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3354     compiled in such a way that the backtracking after subsequent failure was
3355     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3356     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3359 nigel 29 Version 2.03 02-Feb-99
3360     ----------------------
3362     1. Fixed typo and small mistake in man page.
3364 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3365     LICENCE file containing the conditions.
3366 nigel 29
3367     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3368     Perl, that is the internal \ allows the delimiter to be included in the
3369     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3370     the final delimiter, add \ to the end of the pattern (to test the error).
3372     4. Added the convenience functions for extracting substrings after a successful
3373     match. Updated pcretest to make it able to test these functions.
3376 nigel 27 Version 2.02 14-Jan-99
3377     ----------------------
3379     1. Initialized the working variables associated with each extraction so that
3380     their saving and restoring doesn't refer to uninitialized store.
3382     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3383     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3384     fix the problem.
3386     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3387     calls, and wasn't printing the correct value for compiling calls. Increased the
3388     default value of LOOPREPEAT, and the number of significant figures in the
3389     times.
3391     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3393     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3394     a building problem on Windows NT with a FAT file system.
3397 nigel 25 Version 2.01 21-Oct-98
3398     ----------------------
3400     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3401     to character tables built by pcre_maketables() in the current locale. If NULL
3402     is passed, the default tables are used.
3405 nigel 23 Version 2.00 24-Sep-98
3406 nigel 21 ----------------------
3408 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3409     it any more.
3411     2. Allow quantification of (?>) groups, and make it work correctly.
3413     3. The first character computation wasn't working for (?>) groups.
3415     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3416     end of the subject) and add 5.005's \z, which really does match only at the
3417     very end of the subject.
3419     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3421     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3422     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3423     localized options. All options to pcre_study() were also removed.
3425     7. Add other new features from 5.005:
3427     $(?<= positive lookbehind
3428     $(?<! negative lookbehind
3429     (?imsx-imsx) added the unsetting capability
3430     such a setting is global if at outer level; local otherwise
3431     (?imsx-imsx:) non-capturing groups with option setting
3432     (?(cond)re|re) conditional pattern matching
3434     A backreference to itself in a repeated group matches the previous
3435     captured string.
3437     8. General tidying up of studying (both automatic and via "study")
3438     consequential on the addition of new assertions.
3440     9. As in 5.005, unlimited repeated groups that could match an empty substring
3441     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3442     runtime if any iteration does actually match an empty substring.
3444     10. Include the RunTest script in the distribution.
3446     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3447     discrepancies, some of which were old and were also with respect to 5.004. They
3448     have now been fixed.
3451     Version 1.09 28-Apr-98
3452     ----------------------
3454 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3455     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3456     program crashes, or just wrong answers. This did not apply to negated classes
3457     containing more than one character, or to minima other than one.
3460 nigel 19 Version 1.08 27-Mar-98
3461     ----------------------
3463     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3465     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3466     latter must appear before anything that relies on it in the pattern.
3469 nigel 17 Version 1.07 16-Feb-98
3470     ----------------------
3472     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3473     repeat of a potentially empty string).
3476 nigel 15 Version 1.06 23-Jan-98
3477     ----------------------
3479     1. Added Markus Oberhumer's little patches for C++.
3481     2. Literal strings longer than 255 characters were broken.
3484 nigel 13 Version 1.05 23-Dec-97
3485     ----------------------
3487     1. Negated character classes containing more than one character were failing if
3488     PCRE_CASELESS was set at run time.
3491 nigel 11 Version 1.04 19-Dec-97
3492     ----------------------
3494     1. Corrected the man page, where some "const" qualifiers had been omitted.
3496     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3497     input syntax.
3499     3. Fixed memory leak which occurred when a regex with back references was
3500     matched with an offsets vector that wasn't big enough. The temporary memory
3501     that is used in this case wasn't being freed if the match failed.
3503     4. Tidied pcretest to ensure it frees memory that it gets.
3505     5. Temporary memory was being obtained in the case where the passed offsets
3506     vector was exactly big enough.
3508     6. Corrected definition of offsetof() from change 5 below.
3510     7. I had screwed up change 6 below and broken the rules for the use of
3511     setjmp(). Now fixed.
3514 nigel 9 Version 1.03 18-Dec-97
3515     ----------------------
3517     1. A erroneous regex with a missing opening parenthesis was correctly
3518     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3519     on some systems.
3521     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3522     it was reported that one broken compiler failed on the former because "code" is
3523     also an independent variable.
3525     3. The erroneous regex a[]b caused an array overrun reference.
3527     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3528     fail on data ending with that character. (It was going on too far, and checking
3529     the next character, typically a binary zero.) This was specific to the
3530     optimized code for single-character negative classes.
3532     5. Added a contributed patch from the TIN world which does the following:
3534     + Add an undef for memmove, in case the the system defines a macro for it.
3536     + Add a definition of offsetof(), in case there isn't one. (I don't know
3537     the reason behind this - offsetof() is part of the ANSI standard - but
3538     it does no harm).
3540     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3541     most of the places where whitespace preceded '#'. I have given up and
3542     allowed the remaining 2 cases to be at the margin.
3544     + Rename some variables in pcre to eliminate shadowing. This seems very
3545     pedantic, but does no harm, of course.
3547     6. Moved the call to setjmp() into its own function, to get rid of warnings
3548     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3550     7. Constructs such as \d{8,} were compiling into the equivalent of
3551 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3552 nigel 9 outcome, but in this particular case used more store than had been allocated,
3553     which caused the bug to be discovered because it threw up an internal error.
3555     8. The debugging code in both pcre and pcretest for outputting the compiled
3556     form of a regex was going wrong in the case of back references followed by
3557     curly-bracketed repeats.
3560 nigel 7 Version 1.02 12-Dec-97
3561     ----------------------
3563     1. Typos in pcre.3 and comments in the source fixed.
3565     2. Applied a contributed patch to get rid of places where it used to remove
3566     'const' from variables, and fixed some signed/unsigned and uninitialized
3567     variable warnings.
3569     3. Added the "runtest" target to Makefile.
3571     4. Set default compiler flag to -O2 rather than just -O.
3574 nigel 5 Version 1.01 19-Nov-97
3575     ----------------------
3577     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3578     like /([ab]*)*/, that is, for classes with more than one character in them.
3580     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3581     as /((?>a*))*/ (a PCRE_EXTRA facility).
3584     Version 1.00 18-Nov-97
3585     ----------------------
3587     1. Added compile-time macros to support systems such as SunOS4 which don't have
3588     memmove() or strerror() but have other things that can be used instead.
3590     2. Arranged that "make clean" removes the executables.
3593 nigel 3 Version 0.99 27-Oct-97
3594     ----------------------
3596     1. Fixed bug in code for optimizing classes with only one character. It was
3597     initializing a 32-byte map regardless, which could cause it to run off the end
3598     of the memory it had got.
3600     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3603     Version 0.98 22-Oct-97
3604     ----------------------
3606     1. Fixed bug in code for handling temporary memory usage when there are more
3607     back references than supplied space in the ovector. This could cause segfaults.
3610     Version 0.97 21-Oct-97
3611     ----------------------
3613     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3615     2. Optimized negated single characters not to use a bit map.
3617     3. Brought error texts together as macro definitions; clarified some of them;
3618     fixed one that was wrong - it said "range out of order" when it meant "invalid
3619     escape sequence".
3621     4. Changed some char * arguments to const char *.
3623     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3625     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3626     pcretest.
3629     Version 0.96 16-Oct-97
3630     ----------------------
3632     1. Added a simple "pgrep" utility to the distribution.
3634     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3635     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3636     where "ddd" means "one or more decimal digits".
3638     3. Fixed serious bug. If a pattern had a back reference, but the call to
3639     pcre_exec() didn't supply a large enough ovector to record the related
3640     identifying subpattern, the match always failed. PCRE now remembers the number
3641     of the largest back reference, and gets some temporary memory in which to save
3642     the offsets during matching if necessary, in order to ensure that
3643     backreferences always work.
3645     4. Increased the compatibility with Perl in a number of ways:
3647     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3648     to request this handling. The option can be set at compile or exec time.
3650     (b) $ matches before a terminating newline by default; an option
3651     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3652     mode). The option can be set at compile or exec time.
3654     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3655     the same as Perl's. If the decimal number it represents is less than 10
3656     or there aren't that many previous left capturing parentheses, an octal
3657     escape is read. Inside a character class, it's always an octal escape,
3658     even if it is a single digit.
3660     (d) An escaped but undefined alphabetic character is taken as a literal,
3661     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3662     escapes.
3664     (e) {0} is now permitted. (The previous item is removed from the compiled
3665     pattern).
3667     5. Changed all the names of code files so that the basic parts are no longer
3668     than 10 characters, and abolished the teeny "globals.c" file.
3670     6. Changed the handling of character classes; they are now done with a 32-byte
3671     bit map always.
3673     7. Added the -d and /D options to pcretest to make it possible to look at the
3674     internals of compilation without having to recompile pcre.
3677     Version 0.95 23-Sep-97
3678     ----------------------
3680     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3681     \x20 at the start of a run of normal characters. These were being treated as
3682     real characters, instead of the source characters being re-checked.
3685     Version 0.94 18-Sep-97
3686     ----------------------
3688     1. The functions are now thread-safe, with the caveat that the global variables
3689     containing pointers to malloc() and free() or alternative functions are the
3690     same for all threads.
3692     2. Get pcre_study() to generate a bitmap of initial characters for non-
3693     anchored patterns when this is possible, and use it if passed to pcre_exec().
3696     Version 0.93 15-Sep-97
3697     ----------------------
3699     1. /(b)|(:+)/ was computing an incorrect first character.
3701     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3702     but not actually doing anything yet.
3704     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3705     as Perl does (e.g. [-az] or [az-]).
3707     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3708     all possible positions.
3710     5. Split up into different modules to avoid including unneeded functions in a
3711     compiled binary. However, compile and exec are still in one module. The "study"
3712     function is split off.
3714     6. The character tables are now in a separate module whose source is generated
3715     by an auxiliary program - but can then be edited by hand if required. There are
3716     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3717     toupper() in the code.
3719     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3720     make them global. Abolish the function for setting them, as the caller can now
3721     set them directly.
3724     Version 0.92 11-Sep-97
3725     ----------------------
3727     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3728     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3730     2. Caseless matching was not working in character classes if the characters in
3731     the pattern were in upper case.
3733     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3735     4. Make PCRE_ANCHORED public and accept as a compile option.
3737     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3738     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3739     pass them.
3741     6. Give an error if bad option bits passed at compile or run time.
3743     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3744     pcretest to cause it to pass that flag.
3746     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3747     options, and the first character, if set.
3749     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3752     Version 0.91 10-Sep-97
3753     ----------------------
3755     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3756     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3758     2. PCRE was looping on encountering an indefinitely repeated back reference to
3759     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3760     Perl does - treats the match as successful.
3762     ****


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