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Revision 484 - (hide annotations) (download)
Mon Jan 4 17:11:54 2010 UTC (4 years, 3 months ago) by ph10
File size: 180124 byte(s)
Update autogen.sh to try several names for libtoolize.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 471 Version 8.01 11-Dec-09
5     ----------------------
6    
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
28     PCRE_ERROR_DFA_UITEM.
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.
33    
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.
41    
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.
56    
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.
77    
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 482
92     14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
93 ph10 483 causing partial matching to fail when the end of the subject matched \W
94     in a UTF-8 pattern where \W was quantified with a minimum of 3.
95    
96     15. There were some discrepancies between the declarations in pcre_internal.h
97     of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
98     their definitions. The declarations used "const uschar *" and the
99     definitions used USPTR. Even though USPTR is normally defined as "const
100     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
101     reported that: "This difference in casting confuses some C++ compilers, for
102     example, SunCC recognizes above declarations as different functions and
103     generates broken code for hbpcre." I have changed the declarations to use
104     USPTR.
105 ph10 484
106     16. GNU libtool is named differently on some systems. The autogen.sh script now
107     tries several variants such as glibtoolize (MacOSX) and libtoolize1x
108     (FreeBSD).
109 ph10 479
110 ph10 478
111 ph10 479
112 ph10 469 Version 8.00 19-Oct-09
113 ph10 418 ----------------------
114    
115     1. The table for translating pcre_compile() error codes into POSIX error codes
116 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
117     being within the table. This could lead to an OK return being given in
118 ph10 418 error.
119 ph10 461
120     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
121     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
122     in a Windows environment.
123    
124 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
125     zero, as does GNU grep. However, pcregrep was also printing all files when
126     --files-with-matches was added. Now, when both options are given, it prints
127     counts only for those files that have at least one match. (GNU grep just
128 ph10 461 prints the file name in this circumstance, but including the count seems
129     more useful - otherwise, why use --count?) Also ensured that the
130 ph10 420 combination -clh just lists non-zero counts, with no names.
131 ph10 461
132     4. The long form of the pcregrep -F option was incorrectly implemented as
133     --fixed_strings instead of --fixed-strings. This is an incompatible change,
134     but it seems right to fix it, and I didn't think it was worth preserving
135     the old behaviour.
136    
137     5. The command line items --regex=pattern and --regexp=pattern were not
138 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
139 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
140 ph10 422 which are compatible with GNU grep; these now work.
141 ph10 461
142     6. No libpcreposix.pc file was created for pkg-config; there was just
143 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
144 ph10 461
145 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
146 ph10 461 when UCP support is not needed, by modifying the Python script that
147 ph10 425 generates it from Unicode data files. This should not matter if the module
148     is correctly used as a library, but I received one complaint about 50K of
149     unwanted data. My guess is that the person linked everything into his
150     program rather than using a library. Anyway, it does no harm.
151 ph10 461
152 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
153 ph10 461 was a minimum greater than 1 for a wide character in a possessive
154 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
155     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
156     character. Chaos in the form of incorrect output or a compiling loop could
157     result.
158 ph10 461
159 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
160 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
161 ph10 426 partially matched by this function. In addition, if there are at least two
162 ph10 435 slots in the offset vector, the offset of the earliest inspected character
163     for the match and the offset of the end of the subject are set in them when
164 ph10 461 PCRE_ERROR_PARTIAL is returned.
165    
166 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
167     synonymous with PCRE_PARTIAL, for backwards compatibility, and
168     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
169 ph10 462 and may be more useful for multi-segment matching.
170 ph10 461
171     11. Partial matching with pcre_exec() is now more intuitive. A partial match
172     used to be given if ever the end of the subject was reached; now it is
173     given only if matching could not proceed because another character was
174     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
175     string "Z", which now yields "no match" instead of "partial match". In the
176     case of pcre_dfa_exec(), "no match" is given if every matching path for the
177     final character ended with (*FAIL).
178    
179 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
180 ph10 461 if the pattern had a "must contain" character that was already found in the
181 ph10 428 earlier partial match, unless partial matching was again requested. For
182     example, with the pattern /dog.(body)?/, the "must contain" character is
183     "g". If the first part-match was for the string "dog", restarting with
184 ph10 435 "sbody" failed. This bug has been fixed.
185 ph10 461
186     13. The string returned by pcre_dfa_exec() after a partial match has been
187     changed so that it starts at the first inspected character rather than the
188     first character of the match. This makes a difference only if the pattern
189     starts with a lookbehind assertion or \b or \B (\K is not supported by
190     pcre_dfa_exec()). It's an incompatible change, but it makes the two
191 ph10 435 matching functions compatible, and I think it's the right thing to do.
192 ph10 461
193 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
194 ph10 461 so that the demonstration program is easily available in environments where
195     PCRE has not been installed from source.
196    
197 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
198 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
199     library.
200 ph10 461
201 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
202 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
203 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
204 ph10 433 these options useful.
205 ph10 461
206     17. If a caller to the POSIX matching function regexec() passes a non-zero
207 ph10 438 value for nmatch with a NULL value for pmatch, the value of
208 ph10 461 nmatch is forced to zero.
209    
210 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
211 ph10 461 the diff command, as RunTest does. It now checks in the same way as
212 ph10 437 RunTest, and also checks for the -b option.
213 ph10 461
214 ph10 438 19. If an odd number of negated classes containing just a single character
215     interposed, within parentheses, between a forward reference to a named
216 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
217     an internal error, complaining that it could not find the referenced
218 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
219 ph10 461 [The bug was that it was starting one character too far in when skipping
220     over the character class, thus treating the ] as data rather than
221     terminating the class. This meant it could skip too much.]
222    
223 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
224 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
225 ph10 442 to have an empty string match not at the start, even when the pattern is
226 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
227    
228 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
229 ph10 461 than the maximum at the outer level, the higher number was returned, but
230     with unset values at the outer level. The correct (outer level) value is
231 ph10 446 now given.
232 ph10 461
233 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
234     PCRE did not set those parentheses (unlike Perl). I have now found a way to
235     make it do so. The string so far is captured, making this feature
236     compatible with Perl.
237 ph10 461
238     23. The tests have been re-organized, adding tests 11 and 12, to make it
239 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
240 ph10 461
241 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
242 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
243     does. Neither allows recursion.
244    
245     25. I finally figured out how to implement a request to provide the minimum
246     length of subject string that was needed in order to match a given pattern.
247     (It was back references and recursion that I had previously got hung up
248     on.) This code has now been added to pcre_study(); it finds a lower bound
249 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
250     bound, but using it to avoid searching strings that are too short does give
251     some useful speed-ups. The value is available to calling programs via
252     pcre_fullinfo().
253 ph10 461
254 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
255     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
256     study optimizations had never been tested with that matching function.
257     Oops. What is worse, even when it was passed study data, there was a bug in
258     pcre_dfa_exec() that meant it never actually used it. Double oops. There
259     were also very few tests of studied patterns with pcre_dfa_exec().
260 ph10 461
261 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
262     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
263     on the other side of the coin, they are no longer allowed to have different
264     names, because these cannot be distinguished in PCRE, and this has caused
265     confusion. (This is a difference from Perl.)
266 ph10 461
267     28. When duplicate subpattern names are present (necessarily with different
268     numbers, as required by 27 above), and a test is made by name in a
269     conditional pattern, either for a subpattern having been matched, or for
270     recursion in such a pattern, all the associated numbered subpatterns are
271 ph10 459 tested, and the overall condition is true if the condition is true for any
272     one of them. This is the way Perl works, and is also more like the way
273     testing by number works.
274 ph10 418
275 ph10 461
276 ph10 412 Version 7.9 11-Apr-09
277 ph10 376 ---------------------
278    
279 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
280 ph10 376 (pcretest), all targets were linked against these libraries. This included
281     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
282     libraries. This caused unwanted dependencies to be created. This problem
283 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
284 ph10 376 pcretest is linked with readline.
285 ph10 392
286 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
287     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
288     moved outside it again, because FALSE and TRUE are already defined in AIX,
289     but BOOL is not.
290 ph10 392
291     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
292 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
293 ph10 392
294 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
295     hyphens) following file names and line numbers when outputting matching
296 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
297 ph10 376 wording for the --colour (or --color) option.
298 ph10 392
299 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
300     was not coloured; this is different to GNU grep, so I have changed it to be
301     the same.
302 ph10 392
303 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
304 ph10 392 each matching line was coloured. Now it goes on to look for further matches
305     of any of the test patterns, which is the same behaviour as GNU grep.
306    
307     7. A pattern that could match an empty string could cause pcregrep to loop; it
308     doesn't make sense to accept an empty string match in pcregrep, so I have
309 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
310     seems to be how GNU grep behaves.
311 ph10 392
312 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
313 ph10 392 start or after a newline", because the conditional assertion was not being
314     correctly handled. The rule now is that both the assertion and what follows
315     in the first alternative must satisfy the test.
316    
317 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
318 ph10 399 condition was an assertion, PCRE could crash during matching, both with
319     pcre_exec() and pcre_dfa_exec().
320 ph10 392
321     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
322     used for matching.
323    
324     11. Unicode property support in character classes was not working for
325 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
326 ph10 388
327 ph10 392 12. Added the -M command line option to pcretest.
328    
329 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
330 ph10 389
331     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
332 ph10 390
333 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
334 ph10 390 wrapper.
335 ph10 392
336 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
337 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
338 ph10 391 string constants.
339 ph10 405
340 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
341     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
342 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
343     these, but not everybody uses configure.
344    
345     19. A conditional group that had only one branch was not being correctly
346     recognized as an item that could match an empty string. This meant that an
347     enclosing group might also not be so recognized, causing infinite looping
348     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
349     with the subject "ab", where knowledge that the repeated group can match
350 ph10 396 nothing is needed in order to break the loop.
351 ph10 405
352 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
353 ph10 405 exec(), but without supplying a callout function, matching went wrong.
354    
355     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
356     leak if the size of the offset vector was greater than 30. When the vector
357     is smaller, the saved offsets during recursion go onto a local stack
358     vector, but for larger vectors malloc() is used. It was failing to free
359     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
360 ph10 400 error, in fact).
361 ph10 405
362 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
363 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
364     problem, but was untidy.
365 ph10 376
366 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
367     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
368     included within another project.
369 ph10 411
370 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
371     slightly modified by me:
372 ph10 411
373     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
374     not building pcregrep.
375    
376 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
377 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
378    
379 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
380     duplicate group numbers, could behave incorrectly or give incorrect errors,
381     because when scanning forward to find the reference group, PCRE was not
382     taking into account the duplicate group numbers. A pattern such as
383     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
384 ph10 411
385     26. Changed a few more instances of "const unsigned char *" to USPTR, making
386     the feature of a custom pointer more persuasive (as requested by a user).
387 ph10 416
388 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
389 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
390     pre-defined.
391 ph10 392
392 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
393    
394 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
395     in the configuration summary.
396 ph10 405
397 ph10 411
398 ph10 374 Version 7.8 05-Sep-08
399 ph10 349 ---------------------
400    
401     1. Replaced UCP searching code with optimized version as implemented for Ad
402     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
403 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
404     to 5 times on some simple patterns that I tested. Permission was given to
405     distribute the MultiStage2.py script that generates the tables (it's not in
406     the tarball, but is in the Subversion repository).
407 ph10 349
408 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
409     scripts.
410 ph10 358
411 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
412     a group with a zero qualifier. The result of the study could be incorrect,
413 ph10 358 or the function might crash, depending on the pattern.
414    
415     4. Caseless matching was not working for non-ASCII characters in back
416 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
417 ph10 358 It now works when Unicode Property Support is available.
418    
419 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
420     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
421     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
422 ph10 358 truncation.
423 ph10 349
424 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
425    
426 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
427     pointers, in case they are 64-bit values.
428 ph10 371
429     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
430     test 2 if it fails.
431    
432 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
433 ph10 371 and a #define of that name to empty if it is not externally set. This is to
434     allow users of MSVC to set it if necessary.
435    
436     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
437 ph10 359 the convenience functions in the pcre_get.c source file.
438 ph10 371
439 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
440     could cause overwriting and/or a crash. This command provoked a crash in
441 ph10 371 some environments:
442    
443     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
444    
445 ph10 360 This potential security problem was recorded as CVE-2008-2371.
446 ph10 371
447 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
448     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
449 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
450 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
451     pcretest so that it places the subject at the end of its malloc-ed buffer.
452 ph10 371
453 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
454 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
455    
456 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
457 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
458     first line. This applied both to normal and DFA matching.
459    
460 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
461 ph10 371 /^[^d]*?$/8 failed to match "abc".
462 ph10 351
463 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
464    
465     17. Make it more clear in the documentation that values returned from
466 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
467 ph10 357
468 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
469 ph10 368
470 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
471     supplied by Stefan Weber. I made a further small update for 7.8 because
472 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
473     replaced by pcre_ucd.c.
474 ph10 371
475 ph10 373
476 ph10 347 Version 7.7 07-May-08
477 ph10 321 ---------------------
478    
479     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
480 ph10 345 a string to a long long, pretend we don't even have a long long." This is
481 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
482 ph10 345
483 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
484     pre-7.6 versions, which defined a global no_arg variable instead of putting
485 ph10 332 it in the RE class. (See also #8 below.)
486 ph10 345
487     3. Remove a line of dead code, identified by coverity and reported by Nuno
488     Lopes.
489    
490 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
491 ph10 321
492 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
493 ph10 345 of files, instead of just to the final components.
494    
495 ph10 324 (2) If there was more than one level of directory, the subdirectories were
496     skipped unless they satisfied the include/exclude conditions. This is
497     inconsistent with GNU grep (and could even be seen as contrary to the
498     pcregrep specification - which I improved to make it absolutely clear).
499     The action now is always to scan all levels of directory, and just
500     apply the include/exclude patterns to regular files.
501 ph10 345
502 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
503 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
504    
505 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
506 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
507 ph10 326 doesn't support NULs in patterns.
508 ph10 345
509     7. Added some missing "const"s to declarations of static tables in
510     pcre_compile.c and pcre_dfa_exec.c.
511    
512 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
513 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
514 ph10 345 first patch. And a third patch - this was a messy problem.)
515 ph10 321
516 ph10 345 9. Applied Craig's patch to remove the use of push_back().
517    
518 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
519     matching function regexec().
520 ph10 345
521     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
522     which, however, unlike Perl's \g{...}, are subroutine calls, not back
523 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
524     Oniguruma does).
525 ph10 345
526     12. Previously, a group with a zero repeat such as (...){0} was completely
527 ph10 335 omitted from the compiled regex. However, this means that if the group
528     was called as a subroutine from elsewhere in the pattern, things went wrong
529 ph10 345 (an internal error was given). Such groups are now left in the compiled
530     pattern, with a new opcode that causes them to be skipped at execution
531 ph10 335 time.
532 ph10 345
533 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
534     to the way PCRE behaves:
535 ph10 345
536 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
537 ph10 345
538     (b) A back reference to an unmatched subpattern matches an empty string
539 ph10 336 (Perl fails the current match path).
540 ph10 345
541 ph10 341 (c) A data ] in a character class must be notated as \] because if the
542 ph10 345 first data character in a class is ], it defines an empty class. (In
543 ph10 341 Perl it is not possible to have an empty class.) The empty class []
544     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
545     The negative empty class [^] matches any one character, independently
546     of the DOTALL setting.
547 ph10 345
548     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
549 ph10 340 non-existent subpattern following a character class starting with ']' and
550     containing () gave an internal compiling error instead of "reference to
551     non-existent subpattern". Fortunately, when the pattern did exist, the
552 ph10 345 compiled code was correct. (When scanning forwards to check for the
553 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
554 ph10 345 the class, so got the count wrong. When actually compiling, the reference
555 ph10 340 was subsequently set up correctly.)
556 ph10 345
557 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
558 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
559     other assertions are supported. I have made pcre_dfa_exec() support
560     (*FAIL).
561    
562 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
563 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
564     cannot be changed at match time, I realized I could make a small
565     improvement to matching performance by compiling OP_ALLANY instead of
566     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
567     on the OP_ANY path.
568    
569     17. Compiling pcretest on Windows with readline support failed without the
570 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
571 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
572    
573 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
574 ph10 345 ncurses library to be included for pcretest when ReadLine support is
575     requested, but also to allow for it to be overridden. This patch came from
576     Daniel Bergström.
577 ph10 347
578 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
579 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
580     any errors with the current Unicode tables. Thanks to Peter Kankowski for
581     spotting this.
582 ph10 324
583 ph10 332
584 ph10 319 Version 7.6 28-Jan-08
585 ph10 300 ---------------------
586    
587 ph10 302 1. A character class containing a very large number of characters with
588     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
589     overflow.
590 ph10 309
591     2. Patch to cut out the "long long" test in pcrecpp_unittest when
592     HAVE_LONG_LONG is not defined.
593    
594 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
595 ph10 304 bring them up to date and include new features. This patch includes:
596 ph10 309
597 ph10 304 - Fixed PH's badly added libz and libbz2 support.
598     - Fixed a problem with static linking.
599 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
600 ph10 304 - Fixed dftables problem and added an option.
601     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
602     HAVE_LONG_LONG.
603     - Added readline support for pcretest.
604 ph10 309 - Added an listing of the option settings after cmake has run.
605    
606 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
607     "pcre.dll" under mingw when using Configure/Make. I added stuff to
608     Makefile.am that cause it to include this special target, without
609     affecting anything else. Note that the same mingw target plus all
610     the other distribution libraries and programs are now supported
611     when configuring with CMake (see 6 below) instead of with
612     Configure/Make.
613 ph10 309
614 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
615     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
616 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
617     solves the problem, but it does no harm.
618 ph10 313
619 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
620 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
621 ph10 314 with CMake, and also correct the comment about stack recursion.
622 ph10 313
623 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
624 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
625     of a program that users should build themselves after PCRE is installed, so
626     building it automatically is not really right. What is more, it gave
627 ph10 312 trouble in some build environments.
628 ph10 300
629 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
630 ph10 308
631 ph10 319
632 ph10 298 Version 7.5 10-Jan-08
633 ph10 263 ---------------------
634    
635     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
636     values in parens when parsing an RE using the C++ wrapper."
637 ph10 286
638 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
639     Characters greater than 255 were excluded from the class instead of being
640     included.
641 ph10 286
642     3. The same bug as (2) above applied to negated POSIX classes such as
643 ph10 265 [:^space:].
644 ph10 286
645 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
646     defined or documented. It seems to have been a typo for PCRE_STATIC, so
647 ph10 286 I have changed it.
648    
649 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
650 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
651     first named subpattern whose name started with "a" (in other words, the
652 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
653     expected" is now given for (?&) (a zero-length name), and this patch also
654     makes it give the same error for \k'' (previously it complained that that
655     was a reference to a non-existent subpattern).
656 ph10 286
657 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
658 ph10 286 this is right because (?- can be followed by option settings as well as by
659 ph10 269 digits. I have, however, made the messages clearer.
660 ph10 286
661 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
662     than the number used in the conditional) now cause a compile-time error.
663     This is actually not compatible with Perl, which accepts such patterns, but
664     treats the conditional as always being FALSE (as PCRE used to), but it
665     seems to me that giving a diagnostic is better.
666 ph10 286
667 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
668 ph10 275 and messages.
669 ph10 286
670     9. Fix two occurrences of "backslash" in comments that should have been
671     "backspace".
672    
673     10. Remove two redundant lines of code that can never be obeyed (their function
674     was moved elsewhere).
675    
676     11. The program that makes PCRE's Unicode character property table had a bug
677     which caused it to generate incorrect table entries for sequences of
678 ph10 277 characters that have the same character type, but are in different scripts.
679 ph10 286 It amalgamated them into a single range, with the script of the first of
680 ph10 277 them. In other words, some characters were in the wrong script. There were
681     thirteen such cases, affecting characters in the following ranges:
682 ph10 286
683 ph10 277 U+002b0 - U+002c1
684     U+0060c - U+0060d
685 ph10 286 U+0061e - U+00612
686 ph10 277 U+0064b - U+0065e
687     U+0074d - U+0076d
688     U+01800 - U+01805
689     U+01d00 - U+01d77
690     U+01d9b - U+01dbf
691     U+0200b - U+0200f
692     U+030fc - U+030fe
693     U+03260 - U+0327f
694     U+0fb46 - U+0fbb1
695     U+10450 - U+1049d
696 ph10 286
697 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
698     compatible with GNU grep in that, if there was more than one match in a
699     line, it showed only the first of them. It now behaves in the same way as
700     GNU grep.
701 ph10 286
702     13. If the -o and -v options were combined for pcregrep, it printed a blank
703     line for every non-matching line. GNU grep prints nothing, and pcregrep now
704     does the same. The return code can be used to tell if there were any
705     non-matching lines.
706    
707 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
708    
709     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
710 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
711 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
712     and both kinds of lookbehind were skipped).
713    
714 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
715 ph10 284 inclusion of <windows.h> to before rather than after the definition of
716     INVALID_FILE_ATTRIBUTES (patch from David Byron).
717 ph10 263
718 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
719 ph10 286 character property caused pcre_compile() to compile bad code, which led at
720     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
721     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
722     caused the error; without that there was no problem.
723 ph10 263
724 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
725 ph10 286
726 ph10 289 19. Added --enable-pcretest-libreadline.
727 ph10 286
728 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
729 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
730 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
731     later patch that removed the other one (the right fix) and added unit tests
732     that check the return values (which was not done before).
733 ph10 292
734 ph10 291 21. Several CMake things:
735 ph10 287
736 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
737 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
738 ph10 288
739 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
740     linked with the newly-built libraries, not previously installed ones.
741 ph10 291
742 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
743 ph10 298
744     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
745     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
746     UTF-8 newline character). The key issue is that the pattern starts .*;
747     this means that the match must be either at the beginning, or after a
748     newline. The bug was in the code for advancing after a failed match and
749     checking that the new position followed a newline. It was not taking
750 ph10 294 account of UTF-8 characters correctly.
751 ph10 298
752     23. PCRE was behaving differently from Perl in the way it recognized POSIX
753     character classes. PCRE was not treating the sequence [:...:] as a
754     character class unless the ... were all letters. Perl, however, seems to
755     allow any characters between [: and :], though of course it rejects as
756     unknown any "names" that contain non-letters, because all the known class
757     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
758     for example, whereas PCRE did not - it did not recognize a POSIX character
759     class. This seemed a bit dangerous, so the code has been changed to be
760     closer to Perl. The behaviour is not identical to Perl, because PCRE will
761     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
762     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
763     Perl does, and where it didn't before.
764    
765 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
766     Windows environments %n is disabled by default.
767 ph10 292
768    
769 ph10 260 Version 7.4 21-Sep-07
770 ph10 230 ---------------------
771    
772     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
773 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
774     LF". That isn't really right - the whole point of the change was to try to
775     help when there was an actual mention of one of the two characters. So now
776     the change happens only if \r or \n (or a literal CR or LF) character is
777 ph10 230 encountered.
778 ph10 231
779     2. The 32-bit options word was also used for 6 internal flags, but the numbers
780     of both had grown to the point where there were only 3 bits left.
781     Fortunately, there was spare space in the data structure, and so I have
782     moved the internal flags into a new 16-bit field to free up more option
783 ph10 230 bits.
784 ph10 231
785     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
786     but did not set the internal JCHANGED flag - either of these is enough to
787     control the way the "get" function works - but the PCRE_INFO_JCHANGED
788     facility is supposed to tell if (?J) was ever used, so now (?J) at the
789 ph10 230 start sets both bits.
790    
791 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
792     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
793 ph10 230
794 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
795    
796     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
797 ph10 233 compatibility, even though it is no longer used.
798 ph10 243
799     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
800 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
801 ph10 259 windows.h file is present (where different names are used). [This was
802 ph10 257 reversed later after testing - see 16 below.]
803 ph10 243
804     8. Changed all #include <config.h> to #include "config.h". There were also
805 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
806 ph10 243
807 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
808 ph10 243 sequence off the lines that it output.
809    
810     10. It was pointed out to me that arrays of string pointers cause lots of
811     relocations when a shared library is dynamically loaded. A technique of
812     using a single long string with a table of offsets can drastically reduce
813     these. I have refactored PCRE in four places to do this. The result is
814 ph10 240 dramatic:
815 ph10 243
816 ph10 240 Originally: 290
817     After changing UCP table: 187
818 ph10 243 After changing error message table: 43
819 ph10 240 After changing table of "verbs" 36
820     After changing table of Posix names 22
821 ph10 243
822 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
823 ph10 247
824 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
825 ph10 247 unicode-properties was also set.
826    
827 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
828 ph10 231
829 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
830     checked only for CRLF.
831 ph10 233
832 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
833    
834 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
835 ph10 253
836 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
837 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
838     entirely. This removes changes made in 7 above.
839 ph10 256
840 ph10 261 17. The CMake files have been updated, and there is now more information about
841     building with CMake in the NON-UNIX-USE document.
842 ph10 257
843 ph10 261
844 ph10 228 Version 7.3 28-Aug-07
845 ph10 157 ---------------------
846    
847 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
848     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
849     brackets there is not right, since it causes compilers to look for an
850     installed pcre.h, not the version that is in the source that is being
851     compiled (which of course may be different). I have changed it back to:
852 ph10 197
853 ph10 189 #include "pcre.h"
854 ph10 197
855     I have a vague recollection that the change was concerned with compiling in
856     different directories, but in the new build system, that is taken care of
857     by the VPATH setting the Makefile.
858    
859 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
860     when the subject happened to end in the byte 0x85 (e.g. if the last
861     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
862     characters but of course it shouldn't be taken as a newline when it is part
863     of another character. The bug was that, for an unlimited repeat of . in
864     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
865     characters when looking for a newline.
866 ph10 197
867     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
868    
869     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
870     in debug output.
871    
872 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
873     long printing in the pcrecpp unittest when running under MinGW.
874 ph10 189
875 ph10 197 6. ESC_K was left out of the EBCDIC table.
876 ph10 189
877 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
878     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
879     limit also applies to "virtual nesting" when a pattern is recursive, and in
880     this case 1000 isn't so big. I have been able to remove this limit at the
881     expense of backing off one optimization in certain circumstances. Normally,
882     when pcre_exec() would call its internal match() function recursively and
883     immediately return the result unconditionally, it uses a "tail recursion"
884     feature to save stack. However, when a subpattern that can match an empty
885     string has an unlimited repetition quantifier, it no longer makes this
886     optimization. That gives it a stack frame in which to save the data for
887     checking that an empty string has been matched. Previously this was taken
888     from the 1000-entry workspace that had been reserved. So now there is no
889     explicit limit, but more stack is used.
890 ph10 189
891 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
892     syntax that is required for Windows, and which was going wrong for the
893     pcreposix and pcrecpp parts of the library. These were overlooked when this
894     problem was solved for the main library.
895 ph10 197
896 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
897     the size of patterns that contain repeated groups with explicit upper
898     limits. As the maximum quantifier is 65535, the maximum group length was
899     set at 30,000 so that the product of these two numbers did not overflow a
900     32-bit integer. However, it turns out that people want to use groups that
901     are longer than 30,000 bytes (though not repeat them that many times).
902     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
903     made it possible to implement the integer overflow checks in a much more
904     dynamic way, which I have now done. The artificial limitation on group
905     length has been removed - we now have only the limit on the total length of
906     the compiled pattern, which depends on the LINK_SIZE setting.
907 ph10 208
908     10. Fixed a bug in the documentation for get/copy named substring when
909     duplicate names are permitted. If none of the named substrings are set, the
910     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
911     empty string.
912    
913     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
914     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
915     because the ] is interpreted as the first data character and the
916     terminating ] is not found. PCRE has been made compatible with Perl in this
917     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
918     cause memory overwriting.
919    
920 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
921     string has been matched (to stop an infinite loop). It was not recognizing
922 ph10 208 a conditional subpattern that could match an empty string if that
923 ph10 206 subpattern was within another subpattern. For example, it looped when
924 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
925 ph10 206 condition was not nested. This bug has been fixed.
926 ph10 208
927 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
928     past the start of the subject in the presence of bytes with the top bit
929     set, for example "\x8aBCD".
930 ph10 211
931 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
932     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
933 ph10 200
934 ph10 211 14. Optimized (?!) to (*FAIL).
935 ph10 202
936 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
937     This restricts code points to be within the range 0 to 0x10FFFF, excluding
938     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
939     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
940     does: it's just the validity check that is more restrictive.
941 ph10 220
942     16. Inserted checks for integer overflows during escape sequence (backslash)
943     processing, and also fixed erroneous offset values for syntax errors during
944     backslash processing.
945    
946 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
947 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
948    
949 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
950     caused an overrun.
951 ph10 220
952     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
953     something other than just ASCII characters) inside a group that had an
954     unlimited repeat caused a loop at compile time (while checking to see
955     whether the group could match an empty string).
956    
957 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
958     [\P{Any}] did so. (Error in the code for printing property names.)
959 ph10 210
960 ph10 220 21. An orphan \E inside a character class could cause a crash.
961    
962     22. A repeated capturing bracket such as (A)? could cause a wild memory
963 ph10 218 reference during compilation.
964 ph10 220
965     23. There are several functions in pcre_compile() that scan along a compiled
966     expression for various reasons (e.g. to see if it's fixed length for look
967 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
968 ph10 220 present in the pattern. These operators have additional parameters compared
969     with \d, etc, and these were not being taken into account when moving along
970 ph10 218 the compiled data. Specifically:
971 ph10 220
972     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
973     length.
974    
975     (b) An item such as \pL+ within a repeated group could cause crashes or
976 ph10 218 loops.
977 ph10 220
978 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
979 ph10 220 "reference to non-existent subpattern" error.
980    
981 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
982    
983 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
984 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
985 ph10 211
986 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
987 ph10 218
988 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
989 ph10 223 character were causing crashes (broken optimization).
990 ph10 227
991 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
992 ph10 227 \p or \P) caused a compile-time loop.
993    
994 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
995     break. For example, the unstudied pattern [\r\n]A does not match the string
996     "\r\nA" because change 7.0/46 below moves the current point on by two
997     characters after failing to match at the start. However, the pattern \nA
998 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
999     the same is true. There doesn't seem any very clean way out of this, but
1000     what I have chosen to do makes the common cases work: PCRE now takes note
1001     of whether there can be an explicit match for \r or \n anywhere in the
1002     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1003     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1004     pattern has explicit CR or LF references.
1005 ph10 222
1006 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1007 ph10 223
1008 ph10 227
1009 ph10 189 Version 7.2 19-Jun-07
1010     ---------------------
1011    
1012 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1013     which is apparently normally available under Windows.
1014 ph10 159
1015     2. Re-jig the pcregrep tests with different newline settings in an attempt
1016     to make them independent of the local environment's newline setting.
1017 ph10 157
1018 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1019 ph10 165
1020 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1021     was not 2, because the output contained actual offsets. The recent new
1022 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1023     usable with all link sizes.
1024    
1025 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1026     stack recursion. This gives a massive performance boost under BSD, but just
1027 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1028 ph10 164 in all cases.
1029 ph10 172
1030 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1031 ph10 172
1032 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1033     recursion call. It refers to the nth most recently opened parentheses.
1034 ph10 172
1035 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1036 ph10 172 to be opened parentheses.
1037    
1038     (c) Conditions that refer to capturing parentheses can be specified
1039 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1040 ph10 172
1041 ph10 168 (d) \K resets the start of the current match so that everything before
1042 ph10 172 is not part of it.
1043    
1044 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1045 ph10 172
1046 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1047 ph10 172 reference syntax.
1048 ph10 182
1049 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1050 ph10 182 alternative starts with the same number.
1051 ph10 172
1052 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1053    
1054 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1055     PCRE_INFO_JCHANGED.
1056    
1057     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1058     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1059 ph10 170 for detecting groups that can match an empty string.
1060 ph10 159
1061 ph10 172 9. A pattern with a very large number of alternatives (more than several
1062     hundred) was running out of internal workspace during the pre-compile
1063     phase, where pcre_compile() figures out how much memory will be needed. A
1064     bit of new cunning has reduced the workspace needed for groups with
1065     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1066     workspace instead of running out of the 4096 that are available.
1067 ph10 182
1068 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1069 ph10 172
1070 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1071     The report of the bug said:
1072 ph10 182
1073 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1074     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1075 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1076 ph10 185
1077 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1078 ph10 185 it matched the wrong number of bytes.
1079 ph10 172
1080 ph10 179
1081 ph10 155 Version 7.1 24-Apr-07
1082 ph10 98 ---------------------
1083    
1084 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1085 ph10 122 that is more "standard", making use of automake and other Autotools. There
1086 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1087     on this.
1088 ph10 111
1089     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1090     for recursive directory scanning broke on some systems because the files
1091     are not scanned in any specific order and on different systems the order
1092     was different. A call to "sort" has been inserted into RunGrepTest for the
1093     approprate test as a short-term fix. In the longer term there may be an
1094 ph10 100 alternative.
1095 ph10 111
1096 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1097 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1098     people do their own conversions for various reasons). The problems
1099     concerned the use of low-level troff macros .br and .in. I have therefore
1100     removed all such uses from the man pages (some were redundant, some could
1101 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1102     HTML has been updated to handle .nf/.fi and to complain if it encounters
1103     .br or .in.
1104 ph10 111
1105 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1106 ph10 123 arranged for config.h to be included in the distribution, with the name
1107 ph10 111 config.h.generic, for the benefit of those who have to compile without
1108     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1109    
1110     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1111     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1112 ph10 127 makevp.bat for the current PCRE, using the additional files
1113 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1114 ph10 111
1115     6. A Windows user reported a minor discrepancy with test 2, which turned out
1116     to be caused by a trailing space on an input line that had got lost in his
1117 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1118 ph10 111
1119 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1120 ph10 111 that is needed.
1121    
1122 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1123     as "const" (a) because they are and (b) because it helps the PHP
1124     maintainers who have recently made a script to detect big data structures
1125 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1126     to update Builducptable as well, so it won't revert if ucptable.h is ever
1127 ph10 105 re-created.
1128 ph10 111
1129     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1130 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1131 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1132     support is not required. This saves 1.5-2K of code, which is important in
1133 ph10 107 some applications.
1134 ph10 111
1135 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1136 ph10 111 so as not to refer to the tables, even though these functions will never be
1137     called when UTF-8 support is disabled. Otherwise there are problems with a
1138     shared library.
1139    
1140 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1141    
1142     (a) It was defining its arguments as char * instead of void *.
1143    
1144 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1145     a long time ago when I wrote it, but is no longer the case.
1146    
1147 ph10 118 The emulated memove() is provided for those environments that have neither
1148 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1149 ph10 118 is clearly not the case, as these two bugs were recently reported.
1150 ph10 123
1151 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1152 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1153     pages, and it removes trailing spaces from listed files. It also creates
1154     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1155     case, it wraps all the #defines with #ifndefs. This script should be run
1156 ph10 111 before "make dist".
1157 ph10 123
1158 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1159     with Unicode property support.
1160 ph10 123
1161     (a) For a maximizing quantifier, if the two different cases of the
1162     character were of different lengths in their UTF-8 codings (there are
1163     some cases like this - I found 11), and the matching function had to
1164 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1165     were both the same length.
1166 ph10 123
1167     (b) When PCRE was configured to use the heap rather than the stack for
1168     recursion during matching, it was not correctly preserving the data for
1169     the other case of a UTF-8 character when checking ahead for a match
1170     while processing a minimizing repeat. If the check also involved
1171 ph10 115 matching a wide character, but failed, corruption could cause an
1172     erroneous result when trying to check for a repeat of the original
1173     character.
1174 ph10 123
1175 ph10 116 13. Some tidying changes to the testing mechanism:
1176 ph10 98
1177 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1178     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1179 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1180     this for UTF-8.) The configure.ac script no longer substitutes the
1181     relevant variables.
1182    
1183 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1184     with length and offset values. This means that the output is different
1185     for different internal link sizes. Test 2 is skipped for link sizes
1186     other than 2 because of this, bypassing the problem. Unfortunately,
1187     there was also a test in test 3 (the locale tests) that used /B and
1188 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1189     I have added a new /Z option to pcretest that replaces the length and
1190     offset values with spaces. This is now used to make test 3 independent
1191 ph10 122 of link size. (Test 2 will be tidied up later.)
1192 ph10 123
1193     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1194 ph10 122 segmentation fault instead of returning the appropriate error message.
1195 ph10 134
1196 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1197 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1198     This doesn't seem right; it now treats the CRLF combination as the line
1199     ending, and so does not match in that case. It's only a pattern such as ^$
1200     that would hit this one: something like ^ABC$ would have failed after \r
1201     and then tried again after \r\n.
1202    
1203 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1204 ph10 134 in an attempt to make files that differ only in their line terminators
1205     compare equal. This works on Linux.
1206 ph10 142
1207 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1208     as it exited. This is now fixed, thanks to valgrind.
1209 ph10 142
1210 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1211 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1212     was because its rules for how to advance for /g after matching an empty
1213 ph10 143 string at the end of a line did not allow for this case. They now check for
1214     it specially.
1215 ph10 150
1216     20. pcretest is supposed to handle patterns and data of any length, by
1217     extending its buffers when necessary. It was getting this wrong when the
1218 ph10 147 buffer for a data line had to be extended.
1219 ph10 150
1220 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1221 ph10 150 CRLF as a newline sequence.
1222 ph10 152
1223 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1224 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1225     I have nevertheless tidied it up.
1226 ph10 111
1227 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1228 ph10 123
1229 ph10 153 24. Added a man page for pcre-config.
1230 ph10 152
1231 ph10 153
1232 nigel 93 Version 7.0 19-Dec-06
1233     ---------------------
1234    
1235     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1236     moving to gcc 4.1.1.
1237    
1238     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1239     sys/time.h, which is documented as needed for this function. It doesn't
1240     seem to matter on Linux, but it showed up on some releases of OS X.
1241    
1242     3. It seems that there are systems where bytes whose values are greater than
1243     127 match isprint() in the "C" locale. The "C" locale should be the
1244     default when a C program starts up. In most systems, only ASCII printing
1245     characters match isprint(). This difference caused the output from pcretest
1246     to vary, making some of the tests fail. I have changed pcretest so that:
1247    
1248     (a) When it is outputting text in the compiled version of a pattern, bytes
1249     other than 32-126 are always shown as hex escapes.
1250    
1251     (b) When it is outputting text that is a matched part of a subject string,
1252     it does the same, unless a different locale has been set for the match
1253     (using the /L modifier). In this case, it uses isprint() to decide.
1254    
1255     4. Fixed a major bug that caused incorrect computation of the amount of memory
1256     required for a compiled pattern when options that changed within the
1257     pattern affected the logic of the preliminary scan that determines the
1258     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1259     that the computed length was too small. The symptoms of this bug were
1260     either the PCRE error "internal error: code overflow" from pcre_compile(),
1261     or a glibc crash with a message such as "pcretest: free(): invalid next
1262     size (fast)". Examples of patterns that provoked this bug (shown in
1263     pcretest format) are:
1264    
1265     /(?-x: )/x
1266     /(?x)(?-x: \s*#\s*)/
1267     /((?i)[\x{c0}])/8
1268     /(?i:[\x{c0}])/8
1269    
1270     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1271     is now done differently.
1272    
1273     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1274     wrapper classes; (b) implement a new function in the C++ scanner that is
1275     more efficient than the old way of doing things because it avoids levels of
1276     recursion in the regex matching; (c) add a paragraph to the documentation
1277     for the FullMatch() function.
1278    
1279     6. The escape sequence \n was being treated as whatever was defined as
1280     "newline". Not only was this contrary to the documentation, which states
1281     that \n is character 10 (hex 0A), but it also went horribly wrong when
1282     "newline" was defined as CRLF. This has been fixed.
1283    
1284     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1285     was being set to -1 for the "end of line" case (supposedly a value that no
1286     character can have). Though this value is never used (the check for end of
1287     line is "zero bytes in current character"), it caused compiler complaints.
1288     I've changed it to 0xffffffff.
1289    
1290     8. In pcre_version.c, the version string was being built by a sequence of
1291     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1292     string (as it is for production releases) called a macro with an empty
1293     argument. The C standard says the result of this is undefined. The gcc
1294     compiler treats it as an empty string (which was what was wanted) but it is
1295     reported that Visual C gives an error. The source has been hacked around to
1296     avoid this problem.
1297    
1298     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1299     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1300     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1301     of them did).
1302    
1303     10. Originally, pcretest opened its input and output without "b"; then I was
1304     told that "b" was needed in some environments, so it was added for release
1305     5.0 to both the input and output. (It makes no difference on Unix-like
1306     systems.) Later I was told that it is wrong for the input on Windows. I've
1307     now abstracted the modes into two macros, to make it easier to fiddle with
1308     them, and removed "b" from the input mode under Windows.
1309    
1310     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1311    
1312     12. Added -help and --help to pcretest as an official way of being reminded
1313     of the options.
1314    
1315     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1316     and pcrecpp.cc because they annoy compilers at high warning levels.
1317    
1318     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1319    
1320     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1321     scripts are not C programs :-) and which was not noticed because it works
1322     on Linux.
1323    
1324     16. pcretest is supposed to handle any length of pattern and data line (as one
1325     line or as a continued sequence of lines) by extending its input buffer if
1326     necessary. This feature was broken for very long pattern lines, leading to
1327     a string of junk being passed to pcre_compile() if the pattern was longer
1328     than about 50K.
1329    
1330     17. I have done a major re-factoring of the way pcre_compile() computes the
1331     amount of memory needed for a compiled pattern. Previously, there was code
1332     that made a preliminary scan of the pattern in order to do this. That was
1333     OK when PCRE was new, but as the facilities have expanded, it has become
1334     harder and harder to keep it in step with the real compile phase, and there
1335     have been a number of bugs (see for example, 4 above). I have now found a
1336     cunning way of running the real compile function in a "fake" mode that
1337     enables it to compute how much memory it would need, while actually only
1338     ever using a few hundred bytes of working memory and without too many
1339     tests of the mode. This should make future maintenance and development
1340     easier. A side effect of this work is that the limit of 200 on the nesting
1341     depth of parentheses has been removed (though this was never a serious
1342     limitation, I suspect). However, there is a downside: pcre_compile() now
1343     runs more slowly than before (30% or more, depending on the pattern). I
1344     hope this isn't a big issue. There is no effect on runtime performance.
1345    
1346     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1347     newline (only possible for the last line of a file) and it was a
1348     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1349    
1350     19. Added additional timing features to pcretest. (1) The -tm option now times
1351     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1352     separate command line item, by a number that specifies the number of
1353     repeats to use when timing. The default is 50000; this gives better
1354     precision, but takes uncomfortably long for very large patterns.
1355    
1356     20. Extended pcre_study() to be more clever in cases where a branch of a
1357     subpattern has no definite first character. For example, (a*|b*)[cd] would
1358     previously give no result from pcre_study(). Now it recognizes that the
1359     first character must be a, b, c, or d.
1360    
1361     21. There was an incorrect error "recursive call could loop indefinitely" if
1362     a subpattern (or the entire pattern) that was being tested for matching an
1363     empty string contained only one non-empty item after a nested subpattern.
1364     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1365     incorrectly, because the \d was being skipped in the check.
1366    
1367     22. The pcretest program now has a new pattern option /B and a command line
1368     option -b, which is equivalent to adding /B to every pattern. This causes
1369     it to show the compiled bytecode, without the additional information that
1370     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1371     is the same as /B/I).
1372    
1373     23. A new optimization is now able automatically to treat some sequences such
1374     as a*b as a*+b. More specifically, if something simple (such as a character
1375     or a simple class like \d) has an unlimited quantifier, and is followed by
1376     something that cannot possibly match the quantified thing, the quantifier
1377     is automatically "possessified".
1378    
1379     24. A recursive reference to a subpattern whose number was greater than 39
1380     went wrong under certain circumstances in UTF-8 mode. This bug could also
1381     have affected the operation of pcre_study().
1382    
1383     25. Realized that a little bit of performance could be had by replacing
1384     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1385    
1386     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1387    
1388     27. Possessive quantifiers such as a++ were previously implemented by turning
1389     them into atomic groups such as ($>a+). Now they have their own opcodes,
1390     which improves performance. This includes the automatically created ones
1391     from 23 above.
1392    
1393     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1394     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1395     the first matched character to be a colon. This applied both to named and
1396     numbered groups.
1397    
1398     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1399    
1400     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1401     building PCRE on Windows easier, so I have included it in the distribution.
1402    
1403     31. There is now a check in pcretest against a ridiculously large number being
1404     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1405     loop, the loop is abandoned.
1406    
1407     32. Forward references to subpatterns in conditions such as (?(2)...) where
1408     subpattern 2 is defined later cause pcre_compile() to search forwards in
1409     the pattern for the relevant set of parentheses. This search went wrong
1410     when there were unescaped parentheses in a character class, parentheses
1411     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1412    
1413     33. "Subroutine" calls and backreferences were previously restricted to
1414     referencing subpatterns earlier in the regex. This restriction has now
1415     been removed.
1416    
1417     34. Added a number of extra features that are going to be in Perl 5.10. On the
1418     whole, these are just syntactic alternatives for features that PCRE had
1419     previously implemented using the Python syntax or my own invention. The
1420     other formats are all retained for compatibility.
1421    
1422     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1423     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1424     also .NET compatible.
1425    
1426     (b) A recursion or subroutine call to a named group can now be defined as
1427     (?&name) as well as (?P>name).
1428    
1429     (c) A backreference to a named group can now be defined as \k<name> or
1430     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1431     5.10, are also .NET compatible.
1432    
1433     (d) A conditional reference to a named group can now use the syntax
1434     (?(<name>) or (?('name') as well as (?(name).
1435    
1436     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1437     groups (named and numbered) that are never evaluated inline, but can be
1438     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1439     is always false. There may be only one alternative in such a group.
1440    
1441     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1442     as the simple (?(R). The condition is true only if the most recent
1443     recursion is that of the given number or name. It does not search out
1444     through the entire recursion stack.
1445    
1446     (g) The escape \gN or \g{N} has been added, where N is a positive or
1447     negative number, specifying an absolute or relative reference.
1448    
1449     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1450     some "unreachable code" warnings.
1451    
1452     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1453     things, this adds five new scripts.
1454    
1455     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1456     There were also incompatibilities regarding the handling of \Q..\E inside
1457     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1458     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1459    
1460     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1461     matches an empty string, and forcibly breaks the loop. There were bugs in
1462     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1463     against aaaa the result was just "a" rather than "aaaa", for example. Two
1464     separate and independent bugs (that affected different cases) have been
1465     fixed.
1466    
1467     39. Refactored the code to abolish the use of different opcodes for small
1468     capturing bracket numbers. This is a tidy that I avoided doing when I
1469     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1470     The new approach is not only tidier, it makes it possible to reduce the
1471     memory needed to fix the previous bug (38).
1472    
1473     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1474     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1475     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1476     mode.
1477    
1478     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1479     report.
1480    
1481     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1482     copy construction and assignment in the C++ wrapper.
1483    
1484     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1485     couple of bugs that could have given wrong results in the "--newline=crlf"
1486     case.
1487    
1488     44. Added a number of casts and did some reorganization of signed/unsigned int
1489     variables following suggestions from Dair Grant. Also renamed the variable
1490     "this" as "item" because it is a C++ keyword.
1491    
1492     45. Arranged for dftables to add
1493    
1494     #include "pcre_internal.h"
1495    
1496     to pcre_chartables.c because without it, gcc 4.x may remove the array
1497     definition from the final binary if PCRE is built into a static library and
1498     dead code stripping is activated.
1499    
1500     46. For an unanchored pattern, if a match attempt fails at the start of a
1501     newline sequence, and the newline setting is CRLF or ANY, and the next two
1502     characters are CRLF, advance by two characters instead of one.
1503    
1504    
1505 nigel 91 Version 6.7 04-Jul-06
1506     ---------------------
1507    
1508     1. In order to handle tests when input lines are enormously long, pcretest has
1509     been re-factored so that it automatically extends its buffers when
1510     necessary. The code is crude, but this _is_ just a test program. The
1511     default size has been increased from 32K to 50K.
1512    
1513     2. The code in pcre_study() was using the value of the re argument before
1514     testing it for NULL. (Of course, in any sensible call of the function, it
1515     won't be NULL.)
1516    
1517     3. The memmove() emulation function in pcre_internal.h, which is used on
1518     systems that lack both memmove() and bcopy() - that is, hardly ever -
1519     was missing a "static" storage class specifier.
1520    
1521     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1522     containing an extended class (one that cannot be represented by a bitmap
1523     because it contains high-valued characters or Unicode property items, e.g.
1524     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1525     pattern, but PCRE should not loop if you do not (it no longer does).
1526     [Detail: two cases were found: (a) a repeated subpattern containing an
1527     extended class; (b) a recursive reference to a subpattern that followed a
1528     previous extended class. It wasn't skipping over the extended class
1529     correctly when UTF-8 mode was not set.]
1530    
1531     5. A negated single-character class was not being recognized as fixed-length
1532     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1533     compile error "lookbehind assertion is not fixed length".
1534    
1535     6. The RunPerlTest auxiliary script was showing an unexpected difference
1536     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1537     write a Perl script that can interpret lines of an input file either as
1538     byte characters or as UTF-8, which is what "perltest" was being required to
1539     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1540     can't do is switch easily at run time between having the "use utf8;" pragma
1541     or not. In the end, I fudged it by using the RunPerlTest script to insert
1542     "use utf8;" explicitly for the UTF-8 tests.
1543    
1544     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1545     the end of the subject string, contrary to the documentation and to what
1546     Perl does. This was true of both matching functions. Now it matches only at
1547     the start of the subject and immediately after *internal* newlines.
1548    
1549     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1550     a pointer to an int instead of a pointer to an unsigned long int. This
1551     caused problems on 64-bit systems.
1552    
1553     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1554     instance of the 'standard' template library not being so standard".
1555    
1556     10. There was no check on the number of named subpatterns nor the maximum
1557     length of a subpattern name. The product of these values is used to compute
1558     the size of the memory block for a compiled pattern. By supplying a very
1559     long subpattern name and a large number of named subpatterns, the size
1560     computation could be caused to overflow. This is now prevented by limiting
1561     the length of names to 32 characters, and the number of named subpatterns
1562     to 10,000.
1563    
1564     11. Subpatterns that are repeated with specific counts have to be replicated in
1565     the compiled pattern. The size of memory for this was computed from the
1566     length of the subpattern and the repeat count. The latter is limited to
1567     65535, but there was no limit on the former, meaning that integer overflow
1568     could in principle occur. The compiled length of a repeated subpattern is
1569     now limited to 30,000 bytes in order to prevent this.
1570    
1571     12. Added the optional facility to have named substrings with the same name.
1572    
1573     13. Added the ability to use a named substring as a condition, using the
1574     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1575     are numbers (not recommended). Forward references are permitted.
1576    
1577     14. Added forward references in named backreferences (if you see what I mean).
1578    
1579     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1580     pattern could run off the end of the subject. For example, the pattern
1581     "(?s)(.{1,5})"8 did this with the subject "ab".
1582    
1583     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1584     PCRE_CASELESS was set when matching characters that were quantified with ?
1585     or *.
1586    
1587     17. A character class other than a single negated character that had a minimum
1588     but no maximum quantifier - for example [ab]{6,} - was not handled
1589     correctly by pce_dfa_exec(). It would match only one character.
1590    
1591     18. A valid (though odd) pattern that looked like a POSIX character
1592     class but used an invalid character after [ (for example [[,abc,]]) caused
1593     pcre_compile() to give the error "Failed: internal error: code overflow" or
1594     in some cases to crash with a glibc free() error. This could even happen if
1595     the pattern terminated after [[ but there just happened to be a sequence of
1596     letters, a binary zero, and a closing ] in the memory that followed.
1597    
1598     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1599     over the years. Originally (before any Unicode support), just the bottom 8
1600     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1601     output from "man perlunicode" includes this:
1602    
1603     The regular expression compiler produces polymorphic opcodes. That
1604     is, the pattern adapts to the data and automatically switches to
1605     the Unicode character scheme when presented with Unicode data--or
1606     instead uses a traditional byte scheme when presented with byte
1607     data.
1608    
1609     Sadly, a wide octal escape does not cause a switch, and in a string with
1610     no other multibyte characters, these octal escapes are treated as before.
1611     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1612     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1613     Unicode string.
1614    
1615     I have not perpetrated such confusion in PCRE. Up till now, it took just
1616     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1617     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1618     translate to the appropriate multibyte character.
1619    
1620     29. Applied some refactoring to reduce the number of warnings from Microsoft
1621     and Borland compilers. This has included removing the fudge introduced
1622     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1623     a warning about an unused variable.
1624    
1625     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1626     characters since release 4.0, because Perl (from release 5.004) does not.
1627     [Or at least, is documented not to: some releases seem to be in conflict
1628     with the documentation.] However, when a pattern was studied with
1629     pcre_study() and all its branches started with \s, PCRE still included VT
1630     as a possible starting character. Of course, this did no harm; it just
1631     caused an unnecessary match attempt.
1632    
1633     22. Removed a now-redundant internal flag bit that recorded the fact that case
1634     dependency changed within the pattern. This was once needed for "required
1635     byte" processing, but is no longer used. This recovers a now-scarce options
1636     bit. Also moved the least significant internal flag bit to the most-
1637     significant bit of the word, which was not previously used (hangover from
1638     the days when it was an int rather than a uint) to free up another bit for
1639     the future.
1640    
1641     23. Added support for CRLF line endings as well as CR and LF. As well as the
1642     default being selectable at build time, it can now be changed at runtime
1643     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1644     specify that it is scanning data with non-default line endings.
1645    
1646     24. Changed the definition of CXXLINK to make it agree with the definition of
1647     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1648    
1649     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1650     recursions. This makes a big different to stack usage for some patterns.
1651    
1652     26. If a subpattern containing a named recursion or subroutine reference such
1653     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1654     the space required for the compiled pattern went wrong and gave too small a
1655     value. Depending on the environment, this could lead to "Failed: internal
1656     error: code overflow at offset 49" or "glibc detected double free or
1657     corruption" errors.
1658    
1659     27. Applied patches from Google (a) to support the new newline modes and (b) to
1660     advance over multibyte UTF-8 characters in GlobalReplace.
1661    
1662     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1663     difference for some implementation of PCRE in some Windows version.
1664    
1665     29. Added some extra testing facilities to pcretest:
1666    
1667     \q<number> in a data line sets the "match limit" value
1668     \Q<number> in a data line sets the "match recursion limt" value
1669     -S <number> sets the stack size, where <number> is in megabytes
1670    
1671     The -S option isn't available for Windows.
1672    
1673    
1674 nigel 89 Version 6.6 06-Feb-06
1675     ---------------------
1676    
1677     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1678     in pcreposix.h. I have copied the definition from pcre.h.
1679    
1680     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1681     because pcre.h is no longer a built file.
1682    
1683     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1684     not normally included in the compiled code.
1685    
1686    
1687 nigel 87 Version 6.5 01-Feb-06
1688     ---------------------
1689    
1690     1. When using the partial match feature with pcre_dfa_exec(), it was not
1691     anchoring the second and subsequent partial matches at the new starting
1692     point. This could lead to incorrect results. For example, with the pattern
1693     /1234/, partially matching against "123" and then "a4" gave a match.
1694    
1695     2. Changes to pcregrep:
1696    
1697     (a) All non-match returns from pcre_exec() were being treated as failures
1698     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1699     error message is output. Some extra information is given for the
1700     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1701     probably the only errors that are likely to be caused by users (by
1702     specifying a regex that has nested indefinite repeats, for instance).
1703     If there are more than 20 of these errors, pcregrep is abandoned.
1704    
1705     (b) A binary zero was treated as data while matching, but terminated the
1706     output line if it was written out. This has been fixed: binary zeroes
1707     are now no different to any other data bytes.
1708    
1709     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1710     used to set a locale for matching. The --locale=xxxx long option has
1711     been added (no short equivalent) to specify a locale explicitly on the
1712     pcregrep command, overriding the environment variables.
1713    
1714     (d) When -B was used with -n, some line numbers in the output were one less
1715     than they should have been.
1716    
1717     (e) Added the -o (--only-matching) option.
1718    
1719     (f) If -A or -C was used with -c (count only), some lines of context were
1720     accidentally printed for the final match.
1721    
1722     (g) Added the -H (--with-filename) option.
1723    
1724     (h) The combination of options -rh failed to suppress file names for files
1725     that were found from directory arguments.
1726    
1727     (i) Added the -D (--devices) and -d (--directories) options.
1728    
1729     (j) Added the -F (--fixed-strings) option.
1730    
1731     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1732    
1733     (l) Added the --colo(u)r option.
1734    
1735     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1736     is not present by default.
1737    
1738     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1739     items such as (?R) or (?1), when the recursion could match a number of
1740     alternatives. If it matched one of the alternatives, but subsequently,
1741     outside the recursion, there was a failure, the code tried to back up into
1742     the recursion. However, because of the way PCRE is implemented, this is not
1743     possible, and the result was an incorrect result from the match.
1744    
1745     In order to prevent this happening, the specification of recursion has
1746     been changed so that all such subpatterns are automatically treated as
1747     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1748    
1749     4. I had overlooked the fact that, in some locales, there are characters for
1750     which isalpha() is true but neither isupper() nor islower() are true. In
1751     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1752     and ordfeminine) are like this. This affected the treatment of \w and \W
1753     when they appeared in character classes, but not when they appeared outside
1754     a character class. The bit map for "word" characters is now created
1755     separately from the results of isalnum() instead of just taking it from the
1756     upper, lower, and digit maps. (Plus the underscore character, of course.)
1757    
1758     5. The above bug also affected the handling of POSIX character classes such as
1759     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1760     permanent tables. Instead, the bit maps for such a class were previously
1761     created as the appropriate unions of the upper, lower, and digit bitmaps.
1762     Now they are created by subtraction from the [[:word:]] class, which has
1763     its own bitmap.
1764    
1765     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1766     It is created by subtracting the vertical space characters (\x09, \x0a,
1767     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1768     subtraction was done in the overall bitmap for a character class, meaning
1769     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1770     be recognized. This bug has been fixed.
1771    
1772     7. Patches from the folks at Google:
1773    
1774     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1775     real life, but is still worth protecting against".
1776    
1777     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1778     regular expressions".
1779    
1780     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1781     have it.
1782    
1783     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1784     "configure" and the latter not, in order to fix a problem somebody had
1785     with compiling the Arg class on HP-UX.
1786    
1787     (e) Improve the error-handling of the C++ wrapper a little bit.
1788    
1789     (f) New tests for checking recursion limiting.
1790    
1791     8. The pcre_memmove() function, which is used only if the environment does not
1792     have a standard memmove() function (and is therefore rarely compiled),
1793     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1794     returning a result (though PCRE never actually uses the result).
1795    
1796     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1797     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1798     returned instead of calling malloc() with an overflowing number that would
1799     most likely cause subsequent chaos.
1800    
1801     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1802    
1803     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1804     with this option is matched, the nmatch and pmatch options of regexec() are
1805     ignored.
1806    
1807     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1808     provided in case anyone wants to the the POSIX interface with UTF-8
1809     strings.
1810    
1811     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1812     C++ linking (needed for some HP-UX environments).
1813    
1814     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1815     (unused parameter) and in the pcre_printint() function (omitted "default"
1816     switch label when the default is to do nothing).
1817    
1818     15. Added some code to make it possible, when PCRE is compiled as a C++
1819     library, to replace subject pointers for pcre_exec() with a smart pointer
1820     class, thus making it possible to process discontinuous strings.
1821    
1822     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1823     much the same function. They were added by different people who were trying
1824     to make PCRE easy to compile on non-Unix systems. It has been suggested
1825     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1826     for compiling on Windows systems. I have therefore replaced it with
1827     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1828     defaults to "extern" for C or "extern C" for C++, which works fine on
1829     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1830     SCOPE with something explicit in config.h. In addition:
1831    
1832     (a) pcreposix.h still had just "extern" instead of either of these macros;
1833     I have replaced it with PCRE_DATA_SCOPE.
1834    
1835     (b) Functions such as _pcre_xclass(), which are internal to the library,
1836     but external in the C sense, all had PCRE_EXPORT in their definitions.
1837     This is apparently wrong for the Windows case, so I have removed it.
1838     (It makes no difference on Unix-like systems.)
1839    
1840     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1841     of recursive calls to match(). This is different to MATCH_LIMIT because
1842     that limits the total number of calls to match(), not all of which increase
1843     the depth of recursion. Limiting the recursion depth limits the amount of
1844     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1845     when PCRE is compiled, and changed at run time. A patch from Google adds
1846     this functionality to the C++ interface.
1847    
1848     18. Changes to the handling of Unicode character properties:
1849    
1850     (a) Updated the table to Unicode 4.1.0.
1851    
1852     (b) Recognize characters that are not in the table as "Cn" (undefined).
1853    
1854     (c) I revised the way the table is implemented to a much improved format
1855     which includes recognition of ranges. It now supports the ranges that
1856     are defined in UnicodeData.txt, and it also amalgamates other
1857     characters into ranges. This has reduced the number of entries in the
1858     table from around 16,000 to around 3,000, thus reducing its size
1859     considerably. I realized I did not need to use a tree structure after
1860     all - a binary chop search is just as efficient. Having reduced the
1861     number of entries, I extended their size from 6 bytes to 8 bytes to
1862     allow for more data.
1863    
1864     (d) Added support for Unicode script names via properties such as \p{Han}.
1865    
1866     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1867     matching that character.
1868    
1869     20. When matching a repeated Unicode property with a minimum greater than zero,
1870     (for example \pL{2,}), PCRE could look past the end of the subject if it
1871     reached it while seeking the minimum number of characters. This could
1872     happen only if some of the characters were more than one byte long, because
1873     there is a check for at least the minimum number of bytes.
1874    
1875     21. Refactored the implementation of \p and \P so as to be more general, to
1876     allow for more different types of property in future. This has changed the
1877     compiled form incompatibly. Anybody with saved compiled patterns that use
1878     \p or \P will have to recompile them.
1879    
1880     22. Added "Any" and "L&" to the supported property types.
1881    
1882     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1883     but give a compile time error if the value is greater than 0xff.
1884    
1885     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1886     accidentally not being installed or uninstalled.
1887    
1888     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1889     made were to insert the current release number. This seemed silly, because
1890     it made things harder for people building PCRE on systems that don't run
1891     "configure". I have turned pcre.h into a distributed file, no longer built
1892     by "configure", with the version identification directly included. There is
1893     no longer a pcre.h.in file.
1894    
1895     However, this change necessitated a change to the pcre-config script as
1896     well. It is built from pcre-config.in, and one of the substitutions was the
1897     release number. I have updated configure.ac so that ./configure now finds
1898     the release number by grepping pcre.h.
1899    
1900     26. Added the ability to run the tests under valgrind.
1901    
1902    
1903 nigel 85 Version 6.4 05-Sep-05
1904     ---------------------
1905    
1906     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1907     "--" to be printed when multiple files were scanned, even when none of the
1908     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1909     consider it to be a bug, and have restored the previous behaviour.
1910    
1911     2. A couple of code tidies to get rid of compiler warnings.
1912    
1913     3. The pcretest program used to cheat by referring to symbols in the library
1914     whose names begin with _pcre_. These are internal symbols that are not
1915     really supposed to be visible externally, and in some environments it is
1916     possible to suppress them. The cheating is now confined to including
1917     certain files from the library's source, which is a bit cleaner.
1918    
1919     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1920     file's purpose clearer.
1921    
1922     5. Reorganized pcre_ucp_findchar().
1923    
1924    
1925 nigel 83 Version 6.3 15-Aug-05
1926     ---------------------
1927    
1928     1. The file libpcre.pc.in did not have general read permission in the tarball.
1929    
1930     2. There were some problems when building without C++ support:
1931    
1932     (a) If C++ support was not built, "make install" and "make test" still
1933     tried to test it.
1934    
1935     (b) There were problems when the value of CXX was explicitly set. Some
1936     changes have been made to try to fix these, and ...
1937    
1938     (c) --disable-cpp can now be used to explicitly disable C++ support.
1939    
1940     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1941     backslash in a target when C++ was disabled. This confuses some
1942     versions of "make", apparently. Using an intermediate variable solves
1943     this. (Same for CPP_LOBJ.)
1944    
1945     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1946     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1947     necessary on certain architectures.
1948    
1949     4. Added a setting of -export-symbols-regex to the link command to remove
1950     those symbols that are exported in the C sense, but actually are local
1951     within the library, and not documented. Their names all begin with
1952     "_pcre_". This is not a perfect job, because (a) we have to except some
1953     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1954     available (and never for static libraries). I have made a note to try to
1955     find a way round (a) in the future.
1956    
1957    
1958 nigel 81 Version 6.2 01-Aug-05
1959     ---------------------
1960    
1961     1. There was no test for integer overflow of quantifier values. A construction
1962     such as {1111111111111111} would give undefined results. What is worse, if
1963     a minimum quantifier for a parenthesized subpattern overflowed and became
1964     negative, the calculation of the memory size went wrong. This could have
1965     led to memory overwriting.
1966    
1967     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1968    
1969     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1970     operating environments where this matters.
1971    
1972     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1973     PCRE options from within the C++ wrapper.
1974    
1975     5. Named capturing subpatterns were not being correctly counted when a pattern
1976     was compiled. This caused two problems: (a) If there were more than 100
1977     such subpatterns, the calculation of the memory needed for the whole
1978     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1979     back references of the form \12, where the number was greater than 9, were
1980     not recognized as back references, even though there were sufficient
1981     previous subpatterns.
1982    
1983     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1984     versions of gcc, e.g. 2.95.4.
1985    
1986    
1987 nigel 79 Version 6.1 21-Jun-05
1988     ---------------------
1989    
1990     1. There was one reference to the variable "posix" in pcretest.c that was not
1991     surrounded by "#if !defined NOPOSIX".
1992    
1993     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1994     the cross-check on the old pcre_info() function, for the benefit of the
1995     cut-down version of PCRE that is currently imported into Exim.
1996    
1997     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1998     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1999     patterns that start (?i) but I don't think that matters. The use of (?i) is
2000     just an example; this all applies to the other options as well.
2001    
2002     4. Since libtool seems to echo the compile commands it is issuing, the output
2003     from "make" can be reduced a bit by putting "@" in front of each libtool
2004     compile command.
2005    
2006     5. Patch from the folks at Google for configure.in to be a bit more thorough
2007     in checking for a suitable C++ installation before trying to compile the
2008     C++ stuff. This should fix a reported problem when a compiler was present,
2009     but no suitable headers.
2010    
2011     6. The man pages all had just "PCRE" as their title. I have changed them to
2012     be the relevant file name. I have also arranged that these names are
2013     retained in the file doc/pcre.txt, which is a concatenation in text format
2014     of all the man pages except the little individual ones for each function.
2015    
2016     7. The NON-UNIX-USE file had not been updated for the different set of source
2017     files that come with release 6. I also added a few comments about the C++
2018     wrapper.
2019    
2020    
2021 nigel 77 Version 6.0 07-Jun-05
2022     ---------------------
2023    
2024     1. Some minor internal re-organization to help with my DFA experiments.
2025    
2026     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2027     didn't matter for the library itself when fully configured, but did matter
2028     when compiling without UCP support, or within Exim, where the ucp files are
2029     not imported.
2030    
2031     3. Refactoring of the library code to split up the various functions into
2032     different source modules. The addition of the new DFA matching code (see
2033     below) to a single monolithic source would have made it really too
2034     unwieldy, quite apart from causing all the code to be include in a
2035     statically linked application, when only some functions are used. This is
2036     relevant even without the DFA addition now that patterns can be compiled in
2037     one application and matched in another.
2038    
2039     The downside of splitting up is that there have to be some external
2040     functions and data tables that are used internally in different modules of
2041     the library but which are not part of the API. These have all had their
2042     names changed to start with "_pcre_" so that they are unlikely to clash
2043     with other external names.
2044    
2045     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2046     a different (DFA) algorithm. Although it is slower than the original
2047     function, it does have some advantages for certain types of matching
2048     problem.
2049    
2050     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2051     including restarting after a partial match.
2052    
2053     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2054     defined when compiling for Windows was sent to me. I have put it into the
2055     code, though I have no means of testing or verifying it.
2056    
2057     7. Added the pcre_refcount() auxiliary function.
2058    
2059     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2060     match before or at the first newline in the subject string. In pcretest,
2061     the /f option on a pattern can be used to set this.
2062    
2063     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2064     would behave wrongly. This has been present in PCRE since release 4.0.
2065    
2066     10. A number of changes to the pcregrep command:
2067    
2068     (a) Refactored how -x works; insert ^(...)$ instead of setting
2069     PCRE_ANCHORED and checking the length, in preparation for adding
2070     something similar for -w.
2071    
2072     (b) Added the -w (match as a word) option.
2073    
2074     (c) Refactored the way lines are read and buffered so as to have more
2075     than one at a time available.
2076    
2077     (d) Implemented a pcregrep test script.
2078    
2079     (e) Added the -M (multiline match) option. This allows patterns to match
2080     over several lines of the subject. The buffering ensures that at least
2081     8K, or the rest of the document (whichever is the shorter) is available
2082     for matching (and similarly the previous 8K for lookbehind assertions).
2083    
2084     (f) Changed the --help output so that it now says
2085    
2086     -w, --word-regex(p)
2087    
2088     instead of two lines, one with "regex" and the other with "regexp"
2089     because that confused at least one person since the short forms are the
2090     same. (This required a bit of code, as the output is generated
2091     automatically from a table. It wasn't just a text change.)
2092    
2093     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2094     option but starts with a hyphen. Could be a pattern or a path name
2095     starting with a hyphen, for instance.
2096    
2097     (h) "-" can be given as a file name to represent stdin.
2098    
2099     (i) When file names are being printed, "(standard input)" is used for
2100     the standard input, for compatibility with GNU grep. Previously
2101     "<stdin>" was used.
2102    
2103     (j) The option --label=xxx can be used to supply a name to be used for
2104     stdin when file names are being printed. There is no short form.
2105    
2106     (k) Re-factored the options decoding logic because we are going to add
2107     two more options that take data. Such options can now be given in four
2108     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2109    
2110     (l) Added the -A, -B, and -C options for requesting that lines of context
2111     around matches be printed.
2112    
2113     (m) Added the -L option to print the names of files that do not contain
2114     any matching lines, that is, the complement of -l.
2115    
2116     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2117     continue to scan other files.
2118    
2119     (o) The -s option was incorrectly implemented. For compatibility with other
2120     greps, it now suppresses the error message for a non-existent or non-
2121     accessible file (but not the return code). There is a new option called
2122     -q that suppresses the output of matching lines, which was what -s was
2123     previously doing.
2124    
2125     (p) Added --include and --exclude options to specify files for inclusion
2126     and exclusion when recursing.
2127    
2128     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2129     Hopefully, it now does.
2130    
2131     12. Missing cast in pcre_study().
2132    
2133     13. Added an "uninstall" target to the makefile.
2134    
2135     14. Replaced "extern" in the function prototypes in Makefile.in with
2136     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2137     world, but is set differently for Windows.
2138    
2139     15. Added a second compiling function called pcre_compile2(). The only
2140     difference is that it has an extra argument, which is a pointer to an
2141     integer error code. When there is a compile-time failure, this is set
2142     non-zero, in addition to the error test pointer being set to point to an
2143     error message. The new argument may be NULL if no error number is required
2144     (but then you may as well call pcre_compile(), which is now just a
2145     wrapper). This facility is provided because some applications need a
2146     numeric error indication, but it has also enabled me to tidy up the way
2147     compile-time errors are handled in the POSIX wrapper.
2148    
2149     16. Added VPATH=.libs to the makefile; this should help when building with one
2150     prefix path and installing with another. (Or so I'm told by someone who
2151     knows more about this stuff than I do.)
2152    
2153     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2154     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2155     match everything, including newlines. This is not POSIX-compatible, but
2156     somebody wanted the feature. From pcretest it can be activated by using
2157     both the P and the s flags.
2158    
2159     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2160    
2161     19. libpcre.pc was being incorrectly installed as executable.
2162    
2163     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2164     it now also looks for '\r' so that it will work unmodified on Windows.
2165    
2166     21. Added Google's contributed C++ wrapper to the distribution.
2167    
2168     22. Added some untidy missing memory free() calls in pcretest, to keep
2169     Electric Fence happy when testing.
2170    
2171    
2172    
2173 nigel 75 Version 5.0 13-Sep-04
2174     ---------------------
2175    
2176     1. Internal change: literal characters are no longer packed up into items
2177     containing multiple characters in a single byte-string. Each character
2178     is now matched using a separate opcode. However, there may be more than one
2179     byte in the character in UTF-8 mode.
2180    
2181     2. The pcre_callout_block structure has two new fields: pattern_position and
2182     next_item_length. These contain the offset in the pattern to the next match
2183     item, and its length, respectively.
2184    
2185     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2186     insertion of callouts before each pattern item. Added the /C option to
2187     pcretest to make use of this.
2188    
2189     4. On the advice of a Windows user, the lines
2190    
2191     #if defined(_WIN32) || defined(WIN32)
2192     _setmode( _fileno( stdout ), 0x8000 );
2193     #endif /* defined(_WIN32) || defined(WIN32) */
2194    
2195     have been added to the source of pcretest. This apparently does useful
2196     magic in relation to line terminators.
2197    
2198     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2199     for the benefit of those environments where the "b" makes a difference.
2200    
2201     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2202     to know about it. I have put a hack into configure.in that adds in code
2203     to set GCC=yes if CC=icc. This seems to end up at a point in the
2204     generated configure script that is early enough to affect the setting of
2205     compiler options, which is what is needed, but I have no means of testing
2206     whether it really works. (The user who reported this had patched the
2207     generated configure script, which of course I cannot do.)
2208    
2209     LATER: After change 22 below (new libtool files), the configure script
2210     seems to know about icc (and also ecc). Therefore, I have commented out
2211     this hack in configure.in.
2212    
2213     7. Added support for pkg-config (2 patches were sent in).
2214    
2215     8. Negated POSIX character classes that used a combination of internal tables
2216     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2217     [[:^ascii]]. Typically, they would match almost any characters. The other
2218     POSIX classes were not broken in this way.
2219    
2220     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2221     to find the match, as PCRE was deluded into thinking that the match had to
2222     start at the start point or following a newline. The same bug applied to
2223     patterns with negative forward assertions or any backward assertions
2224     preceding ".*" at the start, unless the pattern required a fixed first
2225     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2226    
2227     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2228     starting at the last subject character, bytes beyond the end of the subject
2229     string were read.
2230    
2231     11. Renamed the variable "class" as "classbits" to make life easier for C++
2232     users. (Previously there was a macro definition, but it apparently wasn't
2233     enough.)
2234    
2235     12. Added the new field "tables" to the extra data so that tables can be passed
2236     in at exec time, or the internal tables can be re-selected. This allows
2237     a compiled regex to be saved and re-used at a later time by a different
2238     program that might have everything at different addresses.
2239    
2240     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2241     -R library as well as a -L library.
2242    
2243     14. The debugging options of pcretest (-d on the command line or D on a
2244     pattern) showed incorrect output for anything following an extended class
2245     that contained multibyte characters and which was followed by a quantifier.
2246    
2247     15. Added optional support for general category Unicode character properties
2248     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2249     support. It adds about 90K to the size of the library. The meanings of the
2250     inbuilt class escapes such as \d and \s have NOT been changed.
2251    
2252     16. Updated pcredemo.c to include calls to free() to release the memory for the
2253     compiled pattern.
2254    
2255     17. The generated file chartables.c was being created in the source directory
2256     instead of in the building directory. This caused the build to fail if the
2257     source directory was different from the building directory, and was
2258     read-only.
2259    
2260     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2261     file. No doubt somebody will tell me if they don't make sense... Also added
2262     Dan Mooney's comments about building on OpenVMS.
2263    
2264     19. Added support for partial matching via the PCRE_PARTIAL option for
2265     pcre_exec() and the \P data escape in pcretest.
2266    
2267     20. Extended pcretest with 3 new pattern features:
2268    
2269     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2270     write the compiled pattern to the file whose name is "rest-of-line".
2271     This is a straight binary dump of the data, with the saved pointer to
2272     the character tables forced to be NULL. The study data, if any, is
2273     written too. After writing, pcretest reads a new pattern.
2274    
2275     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2276     compiled pattern from the given file. There must not be any
2277     occurrences of "<" in the file name (pretty unlikely); if there are,
2278     pcretest will instead treat the initial "<" as a pattern delimiter.
2279     After reading in the pattern, pcretest goes on to read data lines as
2280     usual.
2281    
2282     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2283     and 16-bit fields in a compiled pattern, to simulate a pattern that
2284     was compiled on a host of opposite endianness.
2285    
2286     21. The pcre-exec() function can now cope with patterns that were compiled on
2287     hosts of opposite endianness, with this restriction:
2288    
2289     As for any compiled expression that is saved and used later, the tables
2290     pointer field cannot be preserved; the extra_data field in the arguments
2291     to pcre_exec() should be used to pass in a tables address if a value
2292     other than the default internal tables were used at compile time.
2293    
2294     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2295     now diagnosed as an error. Previously, most of the time, a negative number
2296     would have been treated as zero, but if in addition "ovector" was passed as
2297     NULL, a crash could occur.
2298    
2299     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2300     new versions from the libtool 1.5 distribution (the last one is a copy of
2301     a file called libtool.m4). This seems to have fixed the need to patch
2302     "configure" to support Darwin 1.3 (which I used to do). However, I still
2303     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2304     workstation).
2305    
2306     24. Changed the PCRE licence to be the more standard "BSD" licence.
2307    
2308    
2309 nigel 73 Version 4.5 01-Dec-03
2310     ---------------------
2311    
2312     1. There has been some re-arrangement of the code for the match() function so
2313     that it can be compiled in a version that does not call itself recursively.
2314     Instead, it keeps those local variables that need separate instances for
2315     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2316     needs to "recurse". Keeping track of where control must go is done by means
2317     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2318     hide most of the details from the main code, and operates only if
2319     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2320     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2321     operating.
2322    
2323     To make it easier for callers to provide specially tailored get/free
2324     functions for this usage, two new functions, pcre_stack_malloc, and
2325     pcre_stack_free, are used. They are always called in strict stacking order,
2326     and the size of block requested is always the same.
2327    
2328     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2329     PCRE has been compiled to use the stack or the heap for recursion. The
2330     -C option of pcretest uses this to show which version is compiled.
2331    
2332     A new data escape \S, is added to pcretest; it causes the amounts of store
2333     obtained and freed by both kinds of malloc/free at match time to be added
2334     to the output.
2335    
2336     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2337     what's available on my current Linux desktop machine.
2338    
2339     3. When matching a UTF-8 string, the test for a valid string at the start has
2340     been extended. If start_offset is not zero, PCRE now checks that it points
2341     to a byte that is the start of a UTF-8 character. If not, it returns
2342     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2343     this is necessary because there may be backward assertions in the pattern.
2344     When matching the same subject several times, it may save resources to use
2345     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2346    
2347     4. The code for checking the validity of UTF-8 strings has been tightened so
2348     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2349     containing "overlong sequences".
2350    
2351     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2352     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2353     should have been "&", but it just so happened that all the cases this let
2354     through by mistake were picked up later in the function.
2355    
2356     6. I had used a variable called "isblank" - this is a C99 function, causing
2357     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2358    
2359     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2360     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2361     so the version is shown; (c) stop "make test" echoing "./RunTest".
2362    
2363     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2364    
2365     9. The prototype for memmove() for systems that don't have it was using
2366     size_t, but the inclusion of the header that defines size_t was later. I've
2367     moved the #includes for the C headers earlier to avoid this.
2368    
2369     10. Added some adjustments to the code to make it easier to compiler on certain
2370     special systems:
2371    
2372     (a) Some "const" qualifiers were missing.
2373     (b) Added the macro EXPORT before all exported functions; by default this
2374     is defined to be empty.
2375     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2376     that it reads its output file name as an argument instead of writing
2377     to the standard output and assuming this can be redirected.
2378    
2379     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2380     class containing characters with values greater than 255, PCRE compilation
2381     went into a loop.
2382    
2383     12. A recursive reference to a subpattern that was within another subpattern
2384     that had a minimum quantifier of zero caused PCRE to crash. For example,
2385     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2386     recursion. If the recursively-called subpattern itself had a zero repeat,
2387     that was OK.
2388    
2389     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2390     buffer into which it was copied (for escape processing) was still set at
2391     1024, so long lines caused crashes.
2392    
2393     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2394     "internal error: code overflow...". This applied to any character class
2395     that was followed by a possessive quantifier.
2396    
2397     15. Modified the Makefile to add libpcre.la as a prerequisite for
2398     libpcreposix.la because I was told this is needed for a parallel build to
2399     work.
2400    
2401     16. If a pattern that contained .* following optional items at the start was
2402     studied, the wrong optimizing data was generated, leading to matching
2403     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2404     matching string must start with a or b or c. The correct conclusion for
2405     this pattern is that a match can start with any character.
2406    
2407    
2408 nigel 71 Version 4.4 13-Aug-03
2409     ---------------------
2410    
2411     1. In UTF-8 mode, a character class containing characters with values between
2412     127 and 255 was not handled correctly if the compiled pattern was studied.
2413     In fixing this, I have also improved the studying algorithm for such
2414     classes (slightly).
2415    
2416     2. Three internal functions had redundant arguments passed to them. Removal
2417     might give a very teeny performance improvement.
2418    
2419     3. Documentation bug: the value of the capture_top field in a callout is *one
2420     more than* the number of the hightest numbered captured substring.
2421    
2422     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2423     in incorrectly linking with a previously installed version. They now link
2424     explicitly with libpcre.la.
2425    
2426     5. configure.in no longer needs to recognize Cygwin specially.
2427    
2428     6. A problem in pcre.in for Windows platforms is fixed.
2429    
2430     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2431     pcretest, it used to include the size of the study block as part of its
2432     output. Unfortunately, the structure contains a field that has a different
2433     size on different hardware architectures. This meant that the tests that
2434     showed this size failed. As the block is currently always of a fixed size,
2435     this information isn't actually particularly useful in pcretest output, so
2436     I have just removed it.
2437    
2438     8. Three pre-processor statements accidentally did not start in column 1.
2439     Sadly, there are *still* compilers around that complain, even though
2440     standard C has not required this for well over a decade. Sigh.
2441    
2442     9. In pcretest, the code for checking callouts passed small integers in the
2443     callout_data field, which is a void * field. However, some picky compilers
2444     complained about the casts involved for this on 64-bit systems. Now
2445     pcretest passes the address of the small integer instead, which should get
2446     rid of the warnings.
2447    
2448     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2449     both compile and run time, and gives an error if an invalid UTF-8 sequence
2450     is found. There is a option for disabling this check in cases where the
2451     string is known to be correct and/or the maximum performance is wanted.
2452    
2453     11. In response to a bug report, I changed one line in Makefile.in from
2454    
2455     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2456     to
2457     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2458    
2459     to look similar to other lines, but I have no way of telling whether this
2460     is the right thing to do, as I do not use Windows. No doubt I'll get told
2461     if it's wrong...
2462    
2463    
2464 nigel 69 Version 4.3 21-May-03
2465     ---------------------
2466    
2467     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2468     Makefile.
2469    
2470     2. Some refactoring to improve the quality of the code:
2471    
2472     (i) The utf8_table... variables are now declared "const".
2473    
2474     (ii) The code for \cx, which used the "case flipping" table to upper case
2475     lower case letters, now just substracts 32. This is ASCII-specific,
2476     but the whole concept of \cx is ASCII-specific, so it seems
2477     reasonable.
2478    
2479     (iii) PCRE was using its character types table to recognize decimal and
2480     hexadecimal digits in the pattern. This is silly, because it handles
2481     only 0-9, a-f, and A-F, but the character types table is locale-
2482     specific, which means strange things might happen. A private
2483     table is now used for this - though it costs 256 bytes, a table is
2484     much faster than multiple explicit tests. Of course, the standard
2485     character types table is still used for matching digits in subject
2486     strings against \d.
2487    
2488     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2489     ending in _t are). So I've renamed it as ESC_tee.
2490    
2491     3. The first argument for regexec() in the POSIX wrapper should have been
2492     defined as "const".
2493    
2494     4. Changed pcretest to use malloc() for its buffers so that they can be
2495     Electric Fenced for debugging.
2496    
2497     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2498     to read one or more bytes before the start of the subject string. Often this
2499     had no effect on PCRE's behaviour, but in some circumstances it could
2500     provoke a segmentation fault.
2501    
2502     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2503     to try to read one or more bytes before the start of the subject string.
2504    
2505     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2506     UTF-8 support could misbehave in various ways if the subject string
2507     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2508     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2509     back over UTF-8 characters.)
2510    
2511    
2512 nigel 67 Version 4.2 14-Apr-03
2513     ---------------------
2514    
2515     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2516    
2517     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2518     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2519     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2520     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2521     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2522     and BUILD_EXEEXT
2523     Note: automatic setting of the BUILD variables is not yet working
2524     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2525     compile-time but not at link-time
2526     [LINK]: use for linking executables only
2527     make different versions for Windows and non-Windows
2528     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2529     libraries
2530     [LINK_FOR_BUILD]: new variable
2531     [OBJEXT]: use throughout
2532     [EXEEXT]: use throughout
2533     <winshared>: new target
2534     <wininstall>: new target
2535     <dftables.o>: use native compiler
2536     <dftables>: use native linker
2537     <install>: handle Windows platform correctly
2538     <clean>: ditto
2539     <check>: ditto
2540     copy DLL to top builddir before testing
2541    
2542     As part of these changes, -no-undefined was removed again. This was reported
2543     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2544     in any case.
2545    
2546     3. Some tidies to get rid of compiler warnings:
2547    
2548     . In the match_data structure, match_limit was an unsigned long int, whereas
2549     match_call_count was an int. I've made them both unsigned long ints.
2550    
2551     . In pcretest the fact that a const uschar * doesn't automatically cast to
2552     a void * provoked a warning.
2553    
2554     . Turning on some more compiler warnings threw up some "shadow" variables
2555     and a few more missing casts.
2556    
2557     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2558     option, a class that contained a single character with a value between 128
2559     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2560    
2561     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2562     option, a class that contained several characters, but with at least one
2563     whose value was between 128 and 255 caused PCRE to crash.
2564    
2565    
2566 nigel 65 Version 4.1 12-Mar-03
2567     ---------------------
2568 nigel 63
2569 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2570     needed, and a string in dftables.c that was longer than standard compilers are
2571     required to support.
2572    
2573     2. Compiling with Sun's compiler found a few more places where the code could
2574     be tidied up in order to avoid warnings.
2575    
2576     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2577     first of these names is deprecated in the latest Autoconf in favour of the name
2578     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2579     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2580     analogy I have changed it to CFLAGS_FOR_BUILD.
2581    
2582     4. Added -no-undefined to the linking command in the Makefile, because this is
2583     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2584     linking step for the pcreposix library.
2585    
2586     5. PCRE was failing to diagnose the case of two named groups with the same
2587     name.
2588    
2589     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2590     literal character that is needed in the subject for a match, and scans along to
2591     ensure that it is present before embarking on the full matching process. This
2592     saves time in cases of nested unlimited repeats that are never going to match.
2593     Problem: the scan can take a lot of time if the subject is very long (e.g.
2594     megabytes), thus penalizing straightforward matches. It is now done only if the
2595     amount of subject to be scanned is less than 1000 bytes.
2596    
2597     7. A lesser problem with the same optimization is that it was recording the
2598     first character of an anchored pattern as "needed", thus provoking a search
2599     right along the subject, even when the first match of the pattern was going to
2600     fail. The "needed" character is now not set for anchored patterns, unless it
2601     follows something in the pattern that is of non-fixed length. Thus, it still
2602     fulfils its original purpose of finding quick non-matches in cases of nested
2603     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2604    
2605    
2606     Version 4.0 17-Feb-03
2607     ---------------------
2608    
2609 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2610     extended to the end of string, PCRE compiled incorrect data. This could lead to
2611     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2612    
2613     2. Moved to autoconf 2.53 and libtool 1.4.2.
2614    
2615     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2616     the special perltest8 script is no longer needed - all the tests can be run
2617     from a single perltest script.
2618    
2619     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2620     by \s. It has now been removed in PCRE. This means it isn't recognized as
2621     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2622     class [:space:] *does* include VT, thereby creating a mess.
2623    
2624     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2625     space and tab.
2626    
2627     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2628     its new features into the main test script, reducing the number of scripts.
2629    
2630     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2631     were backward compatible, and made the (?i) apply to the whole pattern, as if
2632     /i were given. Now it behaves more logically, and applies the option setting
2633     only to what follows. PCRE has been changed to follow suit. However, if it
2634     finds options settings right at the start of the pattern, it extracts them into
2635     the global options, as before. Thus, they show up in the info data.
2636    
2637     8. Added support for the \Q...\E escape sequence. Characters in between are
2638     treated as literals. This is slightly different from Perl in that $ and @ are
2639     also handled as literals inside the quotes. In Perl, they will cause variable
2640     interpolation. Note the following examples:
2641    
2642     Pattern PCRE matches Perl matches
2643    
2644     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2645     \Qabc\$xyz\E abc\$xyz abc\$xyz
2646     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2647    
2648     For compatibility with Perl, \Q...\E sequences are recognized inside character
2649     classes as well as outside them.
2650    
2651     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2652     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2653     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2654     signed/unsigned warnings.
2655    
2656     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2657     option for pcretest, so I've replaced it by a simple function that does just
2658     that job.
2659    
2660     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2661     "pcregrep -".
2662    
2663     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2664     Java package. This provides some syntactic sugar for simple cases of what my
2665     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2666     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2667     item, you can use this simplified notation. Note that only makes sense with
2668     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2669     greediness, whatever the setting of the PCRE_UNGREEDY option.
2670    
2671     13. A change of greediness default within a pattern was not taking effect at
2672     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2673     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2674     was abstracted outside.
2675    
2676     14. PCRE now supports the \G assertion. It is true when the current matching
2677     position is at the start point of the match. This differs from \A when the
2678     starting offset is non-zero. Used with the /g option of pcretest (or similar
2679     code), it works in the same way as it does for Perl's /g option. If all
2680     alternatives of a regex begin with \G, the expression is anchored to the start
2681     match position, and the "anchored" flag is set in the compiled expression.
2682    
2683     15. Some bugs concerning the handling of certain option changes within patterns
2684     have been fixed. These applied to options other than (?ims). For example,
2685     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2686     been the other way round. Some of this was related to change 7 above.
2687    
2688     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2689     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2690     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2691     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2692    
2693     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2694     mode. Unlike ".", it always matches newline, whatever the setting of
2695     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2696     assertions. Perl allows it, but it doesn't (in general) work because it can't
2697     calculate the length of the lookbehind. At least, that's the case for Perl
2698     5.8.0 - I've been told they are going to document that it doesn't work in
2699     future.
2700    
2701     18. Added an error diagnosis for escapes that PCRE does not support: these are
2702     \L, \l, \N, \P, \p, \U, \u, and \X.
2703    
2704     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2705     reading past the end of the pattern in cases such as /[abcd/.
2706    
2707     20. PCRE was getting more memory than necessary for patterns with classes that
2708     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2709    
2710     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2711     compiling PCRE for use with Virtual Pascal.
2712    
2713     22. Small fix to the Makefile to make it work properly if the build is done
2714     outside the source tree.
2715    
2716     23. Added a new extension: a condition to go with recursion. If a conditional
2717     subpattern starts with (?(R) the "true" branch is used if recursion has
2718     happened, whereas the "false" branch is used only at the top level.
2719    
2720     24. When there was a very long string of literal characters (over 255 bytes
2721     without UTF support, over 250 bytes with UTF support), the computation of how
2722     much memory was required could be incorrect, leading to segfaults or other
2723     strange effects.
2724    
2725     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2726     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2727     there was a subsequent back reference to those brackets. This meant that, for
2728     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2729     possible to check for precisely this case. All we can do is abandon the
2730     optimization if .* occurs inside capturing brackets when there are any back
2731     references whatsoever. (See below for a better fix that came later.)
2732    
2733     26. The handling of the optimization for finding the first character of a
2734     non-anchored pattern, and for finding a character that is required later in the
2735     match were failing in some cases. This didn't break the matching; it just
2736     failed to optimize when it could. The way this is done has been re-implemented.
2737    
2738     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2739    
2740     28. Added a new feature that provides some of the functionality that Perl
2741     provides with (?{...}). The facility is termed a "callout". The way it is done
2742     in PCRE is for the caller to provide an optional function, by setting
2743     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2744     global variable. By default it is unset, which disables all calling out. To get
2745     the function called, the regex must include (?C) at appropriate points. This
2746     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2747     This provides a means of identifying different callout points. When PCRE
2748     reaches such a point in the regex, if pcre_callout has been set, the external
2749     function is called. It is provided with data in a structure called
2750     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2751     matching continues; if it returns a non-zero value, the match at the current
2752     point fails. However, backtracking will occur if possible. [This was changed
2753     later and other features added - see item 49 below.]
2754    
2755     29. pcretest is upgraded to test the callout functionality. It provides a
2756     callout function that displays information. By default, it shows the start of
2757     the match and the current position in the text. There are some new data escapes
2758     to vary what happens:
2759    
2760     \C+ in addition, show current contents of captured substrings
2761     \C- do not supply a callout function
2762     \C!n return 1 when callout number n is reached
2763     \C!n!m return 1 when callout number n is reached for the mth time
2764    
2765     30. If pcregrep was called with the -l option and just a single file name, it
2766     output "<stdin>" if a match was found, instead of the file name.
2767    
2768     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2769     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2770     pcre_exec(). This saves a malloc/free per call. The default value of
2771     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2772     when configuring.
2773    
2774     32. The default maximum size of a compiled pattern is 64K. There have been a
2775     few cases of people hitting this limit. The code now uses macros to handle the
2776     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2777     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2778     configuring. Tests 2 and 5 work only with 2-byte links because they output
2779     debugging information about compiled patterns.
2780    
2781     33. Internal code re-arrangements:
2782    
2783     (a) Moved the debugging function for printing out a compiled regex into
2784     its own source file (printint.c) and used #include to pull it into
2785     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2786     separate copies.
2787    
2788     (b) Defined the list of op-code names for debugging as a macro in
2789     internal.h so that it is next to the definition of the opcodes.
2790    
2791     (c) Defined a table of op-code lengths for simpler skipping along compiled
2792     code. This is again a macro in internal.h so that it is next to the
2793     definition of the opcodes.
2794    
2795     34. Added support for recursive calls to individual subpatterns, along the
2796     lines of Robin Houston's patch (but implemented somewhat differently).
2797    
2798     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2799     allow it to read and process whole directories in Win32. This code was
2800     contributed by Lionel Fourquaux; it has not been tested by me.
2801    
2802     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2803     used to name a group. Names consist of alphanumerics and underscores, and must
2804     be unique. Back references use the syntax (?P=name) and recursive calls use
2805     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2806     numbers. The function pcre_fullinfo() can be used after compilation to extract
2807     a name/number map. There are three relevant calls:
2808    
2809     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2810     PCRE_INFO_NAMECOUNT yields the number of entries
2811     PCRE_INFO_NAMETABLE yields a pointer to the map.
2812    
2813     The map is a vector of fixed-size entries. The size of each entry depends on
2814     the length of the longest name used. The first two bytes of each entry are the
2815     group number, most significant byte first. There follows the corresponding
2816     name, zero terminated. The names are in alphabetical order.
2817    
2818     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2819     case instead of 255. Making it the same both with and without UTF-8 support
2820     means that the same test output works with both.
2821    
2822     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2823     calling malloc() with a zero argument.
2824    
2825     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2826     optimization. I've improved things by keeping a bitmap of backreferences with
2827     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2828     fact referenced, the optimization can be applied. It is unlikely that a
2829     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2830     the match to follow \n) will appear inside brackets with a number greater than
2831     31, but if it does, any back reference > 31 suppresses the optimization.
2832    
2833     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2834     of disabling numbered capturing parentheses. Any opening parenthesis that is
2835     not followed by ? behaves as if it were followed by ?: but named parentheses
2836     can still be used for capturing (and they will acquire numbers in the usual
2837     way).
2838    
2839     41. Redesigned the return codes from the match() function into yes/no/error so
2840     that errors can be passed back from deep inside the nested calls. A malloc
2841     failure while inside a recursive subpattern call now causes the
2842     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2843    
2844     42. It is now possible to set a limit on the number of times the match()
2845     function is called in a call to pcre_exec(). This facility makes it possible to
2846     limit the amount of recursion and backtracking, though not in a directly
2847     obvious way, because the match() function is used in a number of different
2848     circumstances. The count starts from zero for each position in the subject
2849     string (for non-anchored patterns). The default limit is, for compatibility, a
2850     large number, namely 10 000 000. You can change this in two ways:
2851    
2852     (a) When configuring PCRE before making, you can use --with-match-limit=n
2853     to set a default value for the compiled library.
2854    
2855     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2856     a different value is set. See 45 below.
2857    
2858     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2859    
2860     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2861     of things that can be changed at compile time. The first argument specifies
2862     what is wanted and the second points to where the information is to be placed.
2863     The current list of available information is:
2864    
2865     PCRE_CONFIG_UTF8
2866    
2867     The output is an integer that is set to one if UTF-8 support is available;
2868     otherwise it is set to zero.
2869    
2870     PCRE_CONFIG_NEWLINE
2871    
2872     The output is an integer that it set to the value of the code that is used for
2873     newline. It is either LF (10) or CR (13).
2874    
2875     PCRE_CONFIG_LINK_SIZE
2876    
2877     The output is an integer that contains the number of bytes used for internal
2878     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2879    
2880     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2881    
2882     The output is an integer that contains the threshold above which the POSIX
2883     interface uses malloc() for output vectors. See item 31 above.
2884    
2885     PCRE_CONFIG_MATCH_LIMIT
2886    
2887     The output is an unsigned integer that contains the default limit of the number
2888     of match() calls in a pcre_exec() execution. See 42 above.
2889    
2890     44. pcretest has been upgraded by the addition of the -C option. This causes it
2891     to extract all the available output from the new pcre_config() function, and to
2892     output it. The program then exits immediately.
2893    
2894     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2895     order to support additional features. One way would have been to define
2896     pcre_exec2() (for example) with extra arguments, but this would not have been
2897     extensible, and would also have required all calls to the original function to
2898     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2899     is used for passing in "extra" data from pcre_study().
2900    
2901     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2902     contains the following fields:
2903    
2904     flags a bitmap indicating which of the following fields are set
2905     study_data opaque data from pcre_study()
2906     match_limit a way of specifying a limit on match() calls for a specific
2907     call to pcre_exec()
2908     callout_data data for callouts (see 49 below)
2909    
2910     The flag bits are also defined in pcre.h, and are
2911    
2912     PCRE_EXTRA_STUDY_DATA
2913     PCRE_EXTRA_MATCH_LIMIT
2914     PCRE_EXTRA_CALLOUT_DATA
2915    
2916     The pcre_study() function now returns one of these new pcre_extra blocks, with
2917     the actual study data pointed to by the study_data field, and the
2918     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2919     before. That is, this change is entirely upwards-compatible and requires no
2920     change to existing code.
2921    
2922     If you want to pass in additional data to pcre_exec(), you can either place it
2923     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2924     block.
2925    
2926     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2927     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2928     times with different match limits, until it finds the minimum value needed for
2929     pcre_exec() to complete. The value is then output. This can be instructive; for
2930     most simple matches the number is quite small, but for pathological cases it
2931     gets very large very quickly.
2932    
2933     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2934     returns the size of the data block pointed to by the study_data field in a
2935     pcre_extra block, that is, the value that was passed as the argument to
2936     pcre_malloc() when PCRE was getting memory in which to place the information
2937     created by pcre_study(). The fourth argument should point to a size_t variable.
2938     pcretest has been extended so that this information is shown after a successful
2939     pcre_study() call when information about the compiled regex is being displayed.
2940    
2941     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2942     because what follows is always an absolute path. (Later: it turns out that this
2943     is more than cosmetic for MinGW, because it doesn't like empty path
2944     components.)
2945    
2946     49. Some changes have been made to the callout feature (see 28 above):
2947    
2948     (i) A callout function now has three choices for what it returns:
2949    
2950     0 => success, carry on matching
2951     > 0 => failure at this point, but backtrack if possible
2952     < 0 => serious error, return this value from pcre_exec()
2953    
2954     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2955     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2956     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2957     use by callout functions. It will never be used by PCRE itself.
2958    
2959     (ii) The pcre_extra structure (see 45 above) has a void * field called
2960     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2961     pcre_callout_block structure has a field of the same name. The contents of
2962     the field passed in the pcre_extra structure are passed to the callout
2963     function in the corresponding field in the callout block. This makes it
2964     easier to use the same callout-containing regex from multiple threads. For
2965     testing, the pcretest program has a new data escape
2966    
2967     \C*n pass the number n (may be negative) as callout_data
2968    
2969     If the callout function in pcretest receives a non-zero value as
2970     callout_data, it returns that value.
2971    
2972     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2973     there were some redundant $(CFLAGS) in commands that are now specified as
2974     $(LINK), which already includes $(CFLAGS).
2975    
2976     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2977     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2978     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2979     one-byte characters throughout. Note that case-insensitive matching applies
2980     only to characters whose values are less than 256. PCRE doesn't support the
2981     notion of cases for higher-valued characters.
2982    
2983     (i) A character class whose characters are all within 0-255 is handled as
2984     a bit map, and the map is inverted for negative classes. Previously, a
2985     character > 255 always failed to match such a class; however it should
2986     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2987    
2988     (ii) A negated character class with a single character < 255 is coded as
2989     "not this character" (OP_NOT). This wasn't working properly when the test
2990     character was multibyte, either singly or repeated.
2991    
2992     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2993     mode, for example: \x{100}{2,3}.
2994    
2995     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2996     singly or repeated) now correctly test multibyte characters. However,
2997     PCRE doesn't recognize any characters with values greater than 255 as
2998     digits, spaces, or word characters. Such characters always match \D, \S,
2999     and \W, and never match \d, \s, or \w.
3000    
3001     (v) Classes may now contain characters and character ranges with values
3002     greater than 255. For example: [ab\x{100}-\x{400}].
3003    
3004     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3005     PCRE in UTF-8 mode.
3006    
3007     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3008     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3009     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3010     value.)
3011    
3012     53. The single man page has become too large. I have therefore split it up into
3013     a number of separate man pages. These also give rise to individual HTML pages;
3014     these are now put in a separate directory, and there is an index.html page that
3015     lists them all. Some hyperlinking between the pages has been installed.
3016    
3017     54. Added convenience functions for handling named capturing parentheses.
3018    
3019     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3020     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3021     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3022     are faulted.
3023    
3024     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3025     calling configure. These values are used when compiling the dftables.c program
3026     which is run to generate the source of the default character tables. They
3027     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3028     you will need to set these values.
3029    
3030     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3031    
3032    
3033     Version 3.9 02-Jan-02
3034 nigel 61 ---------------------
3035    
3036     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3037    
3038     2. If --disable-static was given, the building process failed when trying to
3039     build pcretest and pcregrep. (For some reason it was using libtool to compile
3040     them, which is not right, as they aren't part of the library.)
3041    
3042    
3043 nigel 59 Version 3.8 18-Dec-01
3044     ---------------------
3045    
3046     1. The experimental UTF-8 code was completely screwed up. It was packing the
3047     bytes in the wrong order. How dumb can you get?
3048    
3049    
3050 nigel 57 Version 3.7 29-Oct-01
3051     ---------------------
3052    
3053     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3054     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3055     this didn't happen under Solaris 8, where I normally test things.
3056    
3057 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3058     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3059     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3060     this fix an hour or so after the initial 3.7 release.)
3061 nigel 57
3062 nigel 59
3063 nigel 55 Version 3.6 23-Oct-01
3064     ---------------------
3065    
3066     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3067     offsets passed as NULL with zero offset count.
3068    
3069     2. The config.guess and config.sub files had not been updated when I moved to
3070     the latest autoconf.
3071    
3072    
3073 nigel 53 Version 3.5 15-Aug-01
3074     ---------------------
3075 nigel 5
3076 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3077     had been forgotten.
3078    
3079     2. By using declared but undefined structures, we can avoid using "void"
3080     definitions in pcre.h while keeping the internal definitions of the structures
3081     private.
3082    
3083     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3084     user point of view, this means that both static and shared libraries are built
3085     by default, but this can be individually controlled. More of the work of
3086     handling this static/shared cases is now inside libtool instead of PCRE's make
3087     file.
3088    
3089     4. The pcretest utility is now installed along with pcregrep because it is
3090     useful for users (to test regexs) and by doing this, it automatically gets
3091     relinked by libtool. The documentation has been turned into a man page, so
3092     there are now .1, .txt, and .html versions in /doc.
3093    
3094     5. Upgrades to pcregrep:
3095     (i) Added long-form option names like gnu grep.
3096     (ii) Added --help to list all options with an explanatory phrase.
3097     (iii) Added -r, --recursive to recurse into sub-directories.
3098     (iv) Added -f, --file to read patterns from a file.
3099    
3100     6. pcre_exec() was referring to its "code" argument before testing that
3101     argument for NULL (and giving an error if it was NULL).
3102    
3103     7. Upgraded Makefile.in to allow for compiling in a different directory from
3104     the source directory.
3105    
3106     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3107     options bits, the pointer it was passed was to an int instead of to an unsigned
3108     long int. This mattered only on 64-bit systems.
3109    
3110     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3111     generated) instead of pcre.in, which it its source. Also made the same change
3112     in several of the .c files.
3113    
3114     10. A new release of gcc defines printf() as a macro, which broke pcretest
3115     because it had an ifdef in the middle of a string argument for printf(). Fixed
3116     by using separate calls to printf().
3117    
3118     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3119     script, to force use of CR or LF instead of \n in the source. On non-Unix
3120     systems, the value can be set in config.h.
3121    
3122     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3123     absolute limit. Changed the text of the error message to make this clear, and
3124     likewise updated the man page.
3125    
3126     13. The limit of 99 on the number of capturing subpatterns has been removed.
3127     The new limit is 65535, which I hope will not be a "real" limit.
3128    
3129    
3130 nigel 51 Version 3.4 22-Aug-00
3131     ---------------------
3132    
3133     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3134    
3135     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3136    
3137    
3138 nigel 49 Version 3.3 01-Aug-00
3139     ---------------------
3140    
3141     1. If an octal character was given, but the value was greater than \377, it
3142     was not getting masked to the least significant bits, as documented. This could
3143     lead to crashes in some systems.
3144    
3145     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3146     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3147    
3148     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3149     These just pass their arguments on to (pcre_free)(), but they are provided
3150     because some uses of PCRE bind it to non-C systems that can call its functions,
3151     but cannot call free() or pcre_free() directly.
3152    
3153     4. Add "make test" as a synonym for "make check". Corrected some comments in
3154     the Makefile.
3155    
3156     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3157     Makefile.
3158    
3159     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3160     command called pgrep for grepping around the active processes.
3161    
3162     7. Added the beginnings of support for UTF-8 character strings.
3163    
3164     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3165     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3166     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3167     out for the ar command.)
3168    
3169    
3170 nigel 47 Version 3.2 12-May-00
3171     ---------------------
3172    
3173     This is purely a bug fixing release.
3174    
3175     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3176     of ZA. This was just one example of several cases that could provoke this bug,
3177     which was introduced by change 9 of version 2.00. The code for breaking
3178     infinite loops after an iteration that matches an empty string was't working
3179     correctly.
3180    
3181     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3182     when matched against abbab (for example). After matching an empty string, it
3183     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3184     caused it to match further down the string than it should.
3185    
3186     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3187     was there because it doesn't seem to be needed, and it causes trouble on some
3188     systems, as it is not a Standard C header. It has been removed.
3189    
3190     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3191     were reported on the Macintosh. The changes were from
3192    
3193     while ((c = *(++ptr)) != 0 && c != '\n');
3194     to
3195     while ((c = *(++ptr)) != 0 && c != '\n') ;
3196    
3197     Totally extraordinary, but if that's what it takes...
3198    
3199     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3200     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3201     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3202     assumes the way PCRE uses memmove() (always moving upwards).
3203    
3204     6. PCRE is being used in one environment where strchr() is not available. There
3205     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3206     faster code anyway.
3207    
3208    
3209 nigel 45 Version 3.1 09-Feb-00
3210     ---------------------
3211    
3212     The only change in this release is the fixing of some bugs in Makefile.in for
3213     the "install" target:
3214    
3215     (1) It was failing to install pcreposix.h.
3216    
3217     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3218    
3219    
3220 nigel 43 Version 3.0 01-Feb-00
3221     ---------------------
3222 nigel 41
3223     1. Add support for the /+ modifier to perltest (to output $` like it does in
3224     pcretest).
3225    
3226     2. Add support for the /g modifier to perltest.
3227    
3228     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3229     matches null strings.
3230    
3231     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3232     pattern. Perl treats empty patterns specially - it reuses the most recent
3233     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3234     effect.
3235    
3236     5. The POSIX interface was broken in that it was just handing over the POSIX
3237     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3238     required a bigger vector, with some working space on the end. This means that
3239     the POSIX wrapper now has to get and free some memory, and copy the results.
3240    
3241 nigel 43 6. Added some simple autoconf support, placing the test data and the
3242     documentation in separate directories, re-organizing some of the
3243     information files, and making it build pcre-config (a GNU standard). Also added
3244     libtool support for building PCRE as a shared library, which is now the
3245     default.
3246 nigel 41
3247 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3248     09 are not valid octal constants. Single digits will be used for minor values
3249     less than 10.
3250    
3251     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3252     existing programs that set these in the POSIX interface can use PCRE without
3253     modification.
3254    
3255     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3256     return all that pcre_info() returns, plus additional data. The pcre_info()
3257     function is retained for compatibility, but is considered to be obsolete.
3258    
3259     10. Added experimental recursion feature (?R) to handle one common case that
3260     Perl 5.6 will be able to do with (?p{...}).
3261    
3262     11. Added support for POSIX character classes like [:alpha:], which Perl is
3263     adopting.
3264    
3265    
3266 nigel 39 Version 2.08 31-Aug-99
3267     ----------------------
3268    
3269     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3270     trying to match at the startoffset position, but instead was moving forward to
3271     the next newline as if a previous match had failed.
3272    
3273     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3274     and could get into a loop if a null string was matched other than at the start
3275     of the subject.
3276    
3277     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3278     be distinguished at compile time, and for completeness also added PCRE_DATE.
3279    
3280     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3281     in GnuWin32 environments.
3282    
3283    
3284 nigel 37 Version 2.07 29-Jul-99
3285     ----------------------
3286    
3287     1. The documentation is now supplied in plain text form and HTML as well as in
3288     the form of man page sources.
3289    
3290     2. C++ compilers don't like assigning (void *) values to other pointer types.
3291     In particular this affects malloc(). Although there is no problem in Standard
3292     C, I've put in casts to keep C++ compilers happy.
3293    
3294     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3295     should be (const char *).
3296    
3297     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3298     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3299     However, I haven't made this a standard facility. The documentation doesn't
3300     mention it, and the Makefile doesn't support it.
3301    
3302     5. The Makefile now contains an "install" target, with editable destinations at
3303     the top of the file. The pcretest program is not installed.
3304    
3305     6. pgrep -V now gives the PCRE version number and date.
3306    
3307     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3308     causing the entire string to be ignored, instead of just the last character.
3309    
3310     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3311     non-matching string, it can take a very, very long time, even for strings of
3312     quite modest length, because of the nested recursion. PCRE now does better in
3313     some of these cases. It does this by remembering the last required literal
3314     character in the pattern, and pre-searching the subject to ensure it is present
3315     before running the real match. In other words, it applies a heuristic to detect
3316     some types of certain failure quickly, and in the above example, if presented
3317     with a string that has no trailing " it gives "no match" very quickly.
3318    
3319     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3320     other alternatives are tried instead.
3321    
3322    
3323 nigel 35 Version 2.06 09-Jun-99
3324     ----------------------
3325    
3326     1. Change pcretest's output for amount of store used to show just the code
3327     space, because the remainder (the data block) varies in size between 32-bit and
3328     64-bit systems.
3329    
3330     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3331     start matching at. This allows lookbehinds to work when searching for multiple
3332     occurrences in a string.
3333    
3334     3. Added additional options to pcretest for testing multiple occurrences:
3335    
3336     /+ outputs the rest of the string that follows a match
3337     /g loops for multiple occurrences, using the new startoffset argument
3338     /G loops for multiple occurrences by passing an incremented pointer
3339    
3340     4. PCRE wasn't doing the "first character" optimization for patterns starting
3341     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3342     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3343     the letter 'x'. On long subject strings, this gives a significant speed-up.
3344    
3345    
3346 nigel 33 Version 2.05 21-Apr-99
3347     ----------------------
3348    
3349     1. Changed the type of magic_number from int to long int so that it works
3350     properly on 16-bit systems.
3351    
3352     2. Fixed a bug which caused patterns starting with .* not to work correctly
3353     when the subject string contained newline characters. PCRE was assuming
3354     anchoring for such patterns in all cases, which is not correct because .* will
3355     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3356     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3357     must be retried after every newline in the subject.
3358    
3359    
3360 nigel 31 Version 2.04 18-Feb-99
3361     ----------------------
3362    
3363     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3364     computation of the store needed to hold the pattern was incorrect (too large).
3365     If such patterns were nested a few deep, this could multiply and become a real
3366     problem.
3367    
3368     2. Added /M option to pcretest to show the memory requirement of a specific
3369     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3370    
3371     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3372     compiled in such a way that the backtracking after subsequent failure was
3373     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3374     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3375    
3376    
3377 nigel 29 Version 2.03 02-Feb-99
3378     ----------------------
3379    
3380     1. Fixed typo and small mistake in man page.
3381    
3382 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3383     LICENCE file containing the conditions.
3384 nigel 29
3385     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3386     Perl, that is the internal \ allows the delimiter to be included in the
3387     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3388     the final delimiter, add \ to the end of the pattern (to test the error).
3389    
3390     4. Added the convenience functions for extracting substrings after a successful
3391     match. Updated pcretest to make it able to test these functions.
3392    
3393    
3394 nigel 27 Version 2.02 14-Jan-99
3395     ----------------------
3396    
3397     1. Initialized the working variables associated with each extraction so that
3398     their saving and restoring doesn't refer to uninitialized store.
3399    
3400     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3401     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3402     fix the problem.
3403    
3404     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3405     calls, and wasn't printing the correct value for compiling calls. Increased the
3406     default value of LOOPREPEAT, and the number of significant figures in the
3407     times.
3408    
3409     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3410    
3411     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3412     a building problem on Windows NT with a FAT file system.
3413    
3414    
3415 nigel 25 Version 2.01 21-Oct-98
3416     ----------------------
3417    
3418     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3419     to character tables built by pcre_maketables() in the current locale. If NULL
3420     is passed, the default tables are used.
3421    
3422    
3423 nigel 23 Version 2.00 24-Sep-98
3424 nigel 21 ----------------------
3425    
3426 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3427     it any more.
3428    
3429     2. Allow quantification of (?>) groups, and make it work correctly.
3430    
3431     3. The first character computation wasn't working for (?>) groups.
3432    
3433     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3434     end of the subject) and add 5.005's \z, which really does match only at the
3435     very end of the subject.
3436    
3437     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3438    
3439     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3440     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3441     localized options. All options to pcre_study() were also removed.
3442    
3443     7. Add other new features from 5.005:
3444    
3445     $(?<= positive lookbehind
3446     $(?<! negative lookbehind
3447     (?imsx-imsx) added the unsetting capability
3448     such a setting is global if at outer level; local otherwise
3449     (?imsx-imsx:) non-capturing groups with option setting
3450     (?(cond)re|re) conditional pattern matching
3451    
3452     A backreference to itself in a repeated group matches the previous
3453     captured string.
3454    
3455     8. General tidying up of studying (both automatic and via "study")
3456     consequential on the addition of new assertions.
3457    
3458     9. As in 5.005, unlimited repeated groups that could match an empty substring
3459     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3460     runtime if any iteration does actually match an empty substring.
3461    
3462     10. Include the RunTest script in the distribution.
3463    
3464     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3465     discrepancies, some of which were old and were also with respect to 5.004. They
3466     have now been fixed.
3467    
3468    
3469     Version 1.09 28-Apr-98
3470     ----------------------
3471    
3472 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3473     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3474     program crashes, or just wrong answers. This did not apply to negated classes
3475     containing more than one character, or to minima other than one.
3476    
3477    
3478 nigel 19 Version 1.08 27-Mar-98
3479     ----------------------
3480    
3481     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3482    
3483     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3484     latter must appear before anything that relies on it in the pattern.
3485    
3486    
3487 nigel 17 Version 1.07 16-Feb-98
3488     ----------------------
3489    
3490     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3491     repeat of a potentially empty string).
3492    
3493    
3494 nigel 15 Version 1.06 23-Jan-98
3495     ----------------------
3496    
3497     1. Added Markus Oberhumer's little patches for C++.
3498    
3499     2. Literal strings longer than 255 characters were broken.
3500    
3501    
3502 nigel 13 Version 1.05 23-Dec-97
3503     ----------------------
3504    
3505     1. Negated character classes containing more than one character were failing if
3506     PCRE_CASELESS was set at run time.
3507    
3508    
3509 nigel 11 Version 1.04 19-Dec-97
3510     ----------------------
3511    
3512     1. Corrected the man page, where some "const" qualifiers had been omitted.
3513    
3514     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3515     input syntax.
3516    
3517     3. Fixed memory leak which occurred when a regex with back references was
3518     matched with an offsets vector that wasn't big enough. The temporary memory
3519     that is used in this case wasn't being freed if the match failed.
3520    
3521     4. Tidied pcretest to ensure it frees memory that it gets.
3522    
3523     5. Temporary memory was being obtained in the case where the passed offsets
3524     vector was exactly big enough.
3525    
3526     6. Corrected definition of offsetof() from change 5 below.
3527    
3528     7. I had screwed up change 6 below and broken the rules for the use of
3529     setjmp(). Now fixed.
3530    
3531    
3532 nigel 9 Version 1.03 18-Dec-97
3533     ----------------------
3534    
3535     1. A erroneous regex with a missing opening parenthesis was correctly
3536     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3537     on some systems.
3538    
3539     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3540     it was reported that one broken compiler failed on the former because "code" is
3541     also an independent variable.
3542    
3543     3. The erroneous regex a[]b caused an array overrun reference.
3544    
3545     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3546     fail on data ending with that character. (It was going on too far, and checking
3547     the next character, typically a binary zero.) This was specific to the
3548     optimized code for single-character negative classes.
3549    
3550     5. Added a contributed patch from the TIN world which does the following:
3551    
3552     + Add an undef for memmove, in case the the system defines a macro for it.
3553    
3554     + Add a definition of offsetof(), in case there isn't one. (I don't know
3555     the reason behind this - offsetof() is part of the ANSI standard - but
3556     it does no harm).
3557    
3558     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3559     most of the places where whitespace preceded '#'. I have given up and
3560     allowed the remaining 2 cases to be at the margin.
3561    
3562     + Rename some variables in pcre to eliminate shadowing. This seems very
3563     pedantic, but does no harm, of course.
3564    
3565     6. Moved the call to setjmp() into its own function, to get rid of warnings
3566     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3567    
3568     7. Constructs such as \d{8,} were compiling into the equivalent of
3569 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3570 nigel 9 outcome, but in this particular case used more store than had been allocated,
3571     which caused the bug to be discovered because it threw up an internal error.
3572    
3573     8. The debugging code in both pcre and pcretest for outputting the compiled
3574     form of a regex was going wrong in the case of back references followed by
3575     curly-bracketed repeats.
3576    
3577    
3578 nigel 7 Version 1.02 12-Dec-97
3579     ----------------------
3580    
3581     1. Typos in pcre.3 and comments in the source fixed.
3582    
3583     2. Applied a contributed patch to get rid of places where it used to remove
3584     'const' from variables, and fixed some signed/unsigned and uninitialized
3585     variable warnings.
3586    
3587     3. Added the "runtest" target to Makefile.
3588    
3589     4. Set default compiler flag to -O2 rather than just -O.
3590    
3591    
3592 nigel 5 Version 1.01 19-Nov-97
3593     ----------------------
3594    
3595     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3596     like /([ab]*)*/, that is, for classes with more than one character in them.
3597    
3598     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3599     as /((?>a*))*/ (a PCRE_EXTRA facility).
3600    
3601    
3602     Version 1.00 18-Nov-97
3603     ----------------------
3604    
3605     1. Added compile-time macros to support systems such as SunOS4 which don't have
3606     memmove() or strerror() but have other things that can be used instead.
3607    
3608     2. Arranged that "make clean" removes the executables.
3609    
3610    
3611 nigel 3 Version 0.99 27-Oct-97
3612     ----------------------
3613    
3614     1. Fixed bug in code for optimizing classes with only one character. It was
3615     initializing a 32-byte map regardless, which could cause it to run off the end
3616     of the memory it had got.
3617    
3618     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3619    
3620    
3621     Version 0.98 22-Oct-97
3622     ----------------------
3623    
3624     1. Fixed bug in code for handling temporary memory usage when there are more
3625     back references than supplied space in the ovector. This could cause segfaults.
3626    
3627    
3628     Version 0.97 21-Oct-97
3629     ----------------------
3630    
3631     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3632    
3633     2. Optimized negated single characters not to use a bit map.
3634    
3635     3. Brought error texts together as macro definitions; clarified some of them;
3636     fixed one that was wrong - it said "range out of order" when it meant "invalid
3637     escape sequence".
3638    
3639     4. Changed some char * arguments to const char *.
3640    
3641     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3642    
3643     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3644     pcretest.
3645    
3646    
3647     Version 0.96 16-Oct-97
3648     ----------------------
3649    
3650     1. Added a simple "pgrep" utility to the distribution.
3651    
3652     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3653     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3654     where "ddd" means "one or more decimal digits".
3655    
3656     3. Fixed serious bug. If a pattern had a back reference, but the call to
3657     pcre_exec() didn't supply a large enough ovector to record the related
3658     identifying subpattern, the match always failed. PCRE now remembers the number
3659     of the largest back reference, and gets some temporary memory in which to save
3660     the offsets during matching if necessary, in order to ensure that
3661     backreferences always work.
3662    
3663     4. Increased the compatibility with Perl in a number of ways:
3664    
3665     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3666     to request this handling. The option can be set at compile or exec time.
3667    
3668     (b) $ matches before a terminating newline by default; an option
3669     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3670     mode). The option can be set at compile or exec time.
3671    
3672     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3673     the same as Perl's. If the decimal number it represents is less than 10
3674     or there aren't that many previous left capturing parentheses, an octal
3675     escape is read. Inside a character class, it's always an octal escape,
3676     even if it is a single digit.
3677    
3678     (d) An escaped but undefined alphabetic character is taken as a literal,
3679     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3680     escapes.
3681    
3682     (e) {0} is now permitted. (The previous item is removed from the compiled
3683     pattern).
3684    
3685     5. Changed all the names of code files so that the basic parts are no longer
3686     than 10 characters, and abolished the teeny "globals.c" file.
3687    
3688     6. Changed the handling of character classes; they are now done with a 32-byte
3689     bit map always.
3690    
3691     7. Added the -d and /D options to pcretest to make it possible to look at the
3692     internals of compilation without having to recompile pcre.
3693    
3694    
3695     Version 0.95 23-Sep-97
3696     ----------------------
3697    
3698     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3699     \x20 at the start of a run of normal characters. These were being treated as
3700     real characters, instead of the source characters being re-checked.
3701    
3702    
3703     Version 0.94 18-Sep-97
3704     ----------------------
3705    
3706     1. The functions are now thread-safe, with the caveat that the global variables
3707     containing pointers to malloc() and free() or alternative functions are the
3708     same for all threads.
3709    
3710     2. Get pcre_study() to generate a bitmap of initial characters for non-
3711     anchored patterns when this is possible, and use it if passed to pcre_exec().
3712    
3713    
3714     Version 0.93 15-Sep-97
3715     ----------------------
3716    
3717     1. /(b)|(:+)/ was computing an incorrect first character.
3718    
3719     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3720     but not actually doing anything yet.
3721    
3722     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3723     as Perl does (e.g. [-az] or [az-]).
3724    
3725     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3726     all possible positions.
3727    
3728     5. Split up into different modules to avoid including unneeded functions in a
3729     compiled binary. However, compile and exec are still in one module. The "study"
3730     function is split off.
3731    
3732     6. The character tables are now in a separate module whose source is generated
3733     by an auxiliary program - but can then be edited by hand if required. There are
3734     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3735     toupper() in the code.
3736    
3737     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3738     make them global. Abolish the function for setting them, as the caller can now
3739     set them directly.
3740    
3741    
3742     Version 0.92 11-Sep-97
3743     ----------------------
3744    
3745     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3746     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3747    
3748     2. Caseless matching was not working in character classes if the characters in
3749     the pattern were in upper case.
3750    
3751     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3752    
3753     4. Make PCRE_ANCHORED public and accept as a compile option.
3754    
3755     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3756     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3757     pass them.
3758    
3759     6. Give an error if bad option bits passed at compile or run time.
3760    
3761     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3762     pcretest to cause it to pass that flag.
3763    
3764     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3765     options, and the first character, if set.
3766    
3767     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3768    
3769    
3770     Version 0.91 10-Sep-97
3771     ----------------------
3772    
3773     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3774     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3775    
3776     2. PCRE was looping on encountering an indefinitely repeated back reference to
3777     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3778     Perl does - treats the match as successful.
3779    
3780     ****

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