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Revision 476 - (hide annotations) (download)
Sun Jan 3 15:37:24 2010 UTC (4 years, 9 months ago) by ph10
File size: 177577 byte(s)
Add casts to avoid compiler warnings.

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 474
30     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     stuff that is necessary.
33 ph10 475
34     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
35     removed. (These were left over from very, very early versions of PCRE.)
36    
37     7. Some cosmetic changes to the code to make life easier when compiling it
38     as part of something else:
39    
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     Linux macro when compiled as a kernel module.
45    
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     module.
49    
50     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     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 ph10 476
57     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
58     2005 (difference between two addresses compared to an unsigned value).
59 ph10 475
60 ph10 473
61    
62 ph10 469 Version 8.00 19-Oct-09
63 ph10 418 ----------------------
64    
65     1. The table for translating pcre_compile() error codes into POSIX error codes
66 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
67     being within the table. This could lead to an OK return being given in
68 ph10 418 error.
69 ph10 461
70     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
71     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
72     in a Windows environment.
73    
74 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
75     zero, as does GNU grep. However, pcregrep was also printing all files when
76     --files-with-matches was added. Now, when both options are given, it prints
77     counts only for those files that have at least one match. (GNU grep just
78 ph10 461 prints the file name in this circumstance, but including the count seems
79     more useful - otherwise, why use --count?) Also ensured that the
80 ph10 420 combination -clh just lists non-zero counts, with no names.
81 ph10 461
82     4. The long form of the pcregrep -F option was incorrectly implemented as
83     --fixed_strings instead of --fixed-strings. This is an incompatible change,
84     but it seems right to fix it, and I didn't think it was worth preserving
85     the old behaviour.
86    
87     5. The command line items --regex=pattern and --regexp=pattern were not
88 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
89 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
90 ph10 422 which are compatible with GNU grep; these now work.
91 ph10 461
92     6. No libpcreposix.pc file was created for pkg-config; there was just
93 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
94 ph10 461
95 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
96 ph10 461 when UCP support is not needed, by modifying the Python script that
97 ph10 425 generates it from Unicode data files. This should not matter if the module
98     is correctly used as a library, but I received one complaint about 50K of
99     unwanted data. My guess is that the person linked everything into his
100     program rather than using a library. Anyway, it does no harm.
101 ph10 461
102 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
103 ph10 461 was a minimum greater than 1 for a wide character in a possessive
104 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
105     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
106     character. Chaos in the form of incorrect output or a compiling loop could
107     result.
108 ph10 461
109 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
110 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
111 ph10 426 partially matched by this function. In addition, if there are at least two
112 ph10 435 slots in the offset vector, the offset of the earliest inspected character
113     for the match and the offset of the end of the subject are set in them when
114 ph10 461 PCRE_ERROR_PARTIAL is returned.
115    
116 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
117     synonymous with PCRE_PARTIAL, for backwards compatibility, and
118     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
119 ph10 462 and may be more useful for multi-segment matching.
120 ph10 461
121     11. Partial matching with pcre_exec() is now more intuitive. A partial match
122     used to be given if ever the end of the subject was reached; now it is
123     given only if matching could not proceed because another character was
124     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
125     string "Z", which now yields "no match" instead of "partial match". In the
126     case of pcre_dfa_exec(), "no match" is given if every matching path for the
127     final character ended with (*FAIL).
128    
129 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
130 ph10 461 if the pattern had a "must contain" character that was already found in the
131 ph10 428 earlier partial match, unless partial matching was again requested. For
132     example, with the pattern /dog.(body)?/, the "must contain" character is
133     "g". If the first part-match was for the string "dog", restarting with
134 ph10 435 "sbody" failed. This bug has been fixed.
135 ph10 461
136     13. The string returned by pcre_dfa_exec() after a partial match has been
137     changed so that it starts at the first inspected character rather than the
138     first character of the match. This makes a difference only if the pattern
139     starts with a lookbehind assertion or \b or \B (\K is not supported by
140     pcre_dfa_exec()). It's an incompatible change, but it makes the two
141 ph10 435 matching functions compatible, and I think it's the right thing to do.
142 ph10 461
143 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
144 ph10 461 so that the demonstration program is easily available in environments where
145     PCRE has not been installed from source.
146    
147 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
148 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
149     library.
150 ph10 461
151 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
152 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
153 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
154 ph10 433 these options useful.
155 ph10 461
156     17. If a caller to the POSIX matching function regexec() passes a non-zero
157 ph10 438 value for nmatch with a NULL value for pmatch, the value of
158 ph10 461 nmatch is forced to zero.
159    
160 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
161 ph10 461 the diff command, as RunTest does. It now checks in the same way as
162 ph10 437 RunTest, and also checks for the -b option.
163 ph10 461
164 ph10 438 19. If an odd number of negated classes containing just a single character
165     interposed, within parentheses, between a forward reference to a named
166 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
167     an internal error, complaining that it could not find the referenced
168 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
169 ph10 461 [The bug was that it was starting one character too far in when skipping
170     over the character class, thus treating the ] as data rather than
171     terminating the class. This meant it could skip too much.]
172    
173 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
174 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
175 ph10 442 to have an empty string match not at the start, even when the pattern is
176 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
177    
178 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
179 ph10 461 than the maximum at the outer level, the higher number was returned, but
180     with unset values at the outer level. The correct (outer level) value is
181 ph10 446 now given.
182 ph10 461
183 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
184     PCRE did not set those parentheses (unlike Perl). I have now found a way to
185     make it do so. The string so far is captured, making this feature
186     compatible with Perl.
187 ph10 461
188     23. The tests have been re-organized, adding tests 11 and 12, to make it
189 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
190 ph10 461
191 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
192 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
193     does. Neither allows recursion.
194    
195     25. I finally figured out how to implement a request to provide the minimum
196     length of subject string that was needed in order to match a given pattern.
197     (It was back references and recursion that I had previously got hung up
198     on.) This code has now been added to pcre_study(); it finds a lower bound
199 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
200     bound, but using it to avoid searching strings that are too short does give
201     some useful speed-ups. The value is available to calling programs via
202     pcre_fullinfo().
203 ph10 461
204 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
205     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
206     study optimizations had never been tested with that matching function.
207     Oops. What is worse, even when it was passed study data, there was a bug in
208     pcre_dfa_exec() that meant it never actually used it. Double oops. There
209     were also very few tests of studied patterns with pcre_dfa_exec().
210 ph10 461
211 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
212     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
213     on the other side of the coin, they are no longer allowed to have different
214     names, because these cannot be distinguished in PCRE, and this has caused
215     confusion. (This is a difference from Perl.)
216 ph10 461
217     28. When duplicate subpattern names are present (necessarily with different
218     numbers, as required by 27 above), and a test is made by name in a
219     conditional pattern, either for a subpattern having been matched, or for
220     recursion in such a pattern, all the associated numbered subpatterns are
221 ph10 459 tested, and the overall condition is true if the condition is true for any
222     one of them. This is the way Perl works, and is also more like the way
223     testing by number works.
224 ph10 418
225 ph10 461
226 ph10 412 Version 7.9 11-Apr-09
227 ph10 376 ---------------------
228    
229 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
230 ph10 376 (pcretest), all targets were linked against these libraries. This included
231     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
232     libraries. This caused unwanted dependencies to be created. This problem
233 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
234 ph10 376 pcretest is linked with readline.
235 ph10 392
236 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
237     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
238     moved outside it again, because FALSE and TRUE are already defined in AIX,
239     but BOOL is not.
240 ph10 392
241     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
242 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
243 ph10 392
244 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
245     hyphens) following file names and line numbers when outputting matching
246 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
247 ph10 376 wording for the --colour (or --color) option.
248 ph10 392
249 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
250     was not coloured; this is different to GNU grep, so I have changed it to be
251     the same.
252 ph10 392
253 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
254 ph10 392 each matching line was coloured. Now it goes on to look for further matches
255     of any of the test patterns, which is the same behaviour as GNU grep.
256    
257     7. A pattern that could match an empty string could cause pcregrep to loop; it
258     doesn't make sense to accept an empty string match in pcregrep, so I have
259 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
260     seems to be how GNU grep behaves.
261 ph10 392
262 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
263 ph10 392 start or after a newline", because the conditional assertion was not being
264     correctly handled. The rule now is that both the assertion and what follows
265     in the first alternative must satisfy the test.
266    
267 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
268 ph10 399 condition was an assertion, PCRE could crash during matching, both with
269     pcre_exec() and pcre_dfa_exec().
270 ph10 392
271     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
272     used for matching.
273    
274     11. Unicode property support in character classes was not working for
275 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
276 ph10 388
277 ph10 392 12. Added the -M command line option to pcretest.
278    
279 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
280 ph10 389
281     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
282 ph10 390
283 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
284 ph10 390 wrapper.
285 ph10 392
286 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
287 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
288 ph10 391 string constants.
289 ph10 405
290 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
291     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
292 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
293     these, but not everybody uses configure.
294    
295     19. A conditional group that had only one branch was not being correctly
296     recognized as an item that could match an empty string. This meant that an
297     enclosing group might also not be so recognized, causing infinite looping
298     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
299     with the subject "ab", where knowledge that the repeated group can match
300 ph10 396 nothing is needed in order to break the loop.
301 ph10 405
302 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
303 ph10 405 exec(), but without supplying a callout function, matching went wrong.
304    
305     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
306     leak if the size of the offset vector was greater than 30. When the vector
307     is smaller, the saved offsets during recursion go onto a local stack
308     vector, but for larger vectors malloc() is used. It was failing to free
309     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
310 ph10 400 error, in fact).
311 ph10 405
312 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
313 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
314     problem, but was untidy.
315 ph10 376
316 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
317     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
318     included within another project.
319 ph10 411
320 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
321     slightly modified by me:
322 ph10 411
323     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
324     not building pcregrep.
325    
326 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
327 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
328    
329 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
330     duplicate group numbers, could behave incorrectly or give incorrect errors,
331     because when scanning forward to find the reference group, PCRE was not
332     taking into account the duplicate group numbers. A pattern such as
333     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
334 ph10 411
335     26. Changed a few more instances of "const unsigned char *" to USPTR, making
336     the feature of a custom pointer more persuasive (as requested by a user).
337 ph10 416
338 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
339 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
340     pre-defined.
341 ph10 392
342 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
343    
344 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
345     in the configuration summary.
346 ph10 405
347 ph10 411
348 ph10 374 Version 7.8 05-Sep-08
349 ph10 349 ---------------------
350    
351     1. Replaced UCP searching code with optimized version as implemented for Ad
352     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
353 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
354     to 5 times on some simple patterns that I tested. Permission was given to
355     distribute the MultiStage2.py script that generates the tables (it's not in
356     the tarball, but is in the Subversion repository).
357 ph10 349
358 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
359     scripts.
360 ph10 358
361 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
362     a group with a zero qualifier. The result of the study could be incorrect,
363 ph10 358 or the function might crash, depending on the pattern.
364    
365     4. Caseless matching was not working for non-ASCII characters in back
366 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
367 ph10 358 It now works when Unicode Property Support is available.
368    
369 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
370     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
371     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
372 ph10 358 truncation.
373 ph10 349
374 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
375    
376 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
377     pointers, in case they are 64-bit values.
378 ph10 371
379     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
380     test 2 if it fails.
381    
382 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
383 ph10 371 and a #define of that name to empty if it is not externally set. This is to
384     allow users of MSVC to set it if necessary.
385    
386     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
387 ph10 359 the convenience functions in the pcre_get.c source file.
388 ph10 371
389 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
390     could cause overwriting and/or a crash. This command provoked a crash in
391 ph10 371 some environments:
392    
393     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
394    
395 ph10 360 This potential security problem was recorded as CVE-2008-2371.
396 ph10 371
397 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
398     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
399 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
400 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
401     pcretest so that it places the subject at the end of its malloc-ed buffer.
402 ph10 371
403 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
404 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
405    
406 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
407 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
408     first line. This applied both to normal and DFA matching.
409    
410 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
411 ph10 371 /^[^d]*?$/8 failed to match "abc".
412 ph10 351
413 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
414    
415     17. Make it more clear in the documentation that values returned from
416 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
417 ph10 357
418 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
419 ph10 368
420 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
421     supplied by Stefan Weber. I made a further small update for 7.8 because
422 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
423     replaced by pcre_ucd.c.
424 ph10 371
425 ph10 373
426 ph10 347 Version 7.7 07-May-08
427 ph10 321 ---------------------
428    
429     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
430 ph10 345 a string to a long long, pretend we don't even have a long long." This is
431 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
432 ph10 345
433 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
434     pre-7.6 versions, which defined a global no_arg variable instead of putting
435 ph10 332 it in the RE class. (See also #8 below.)
436 ph10 345
437     3. Remove a line of dead code, identified by coverity and reported by Nuno
438     Lopes.
439    
440 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
441 ph10 321
442 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
443 ph10 345 of files, instead of just to the final components.
444    
445 ph10 324 (2) If there was more than one level of directory, the subdirectories were
446     skipped unless they satisfied the include/exclude conditions. This is
447     inconsistent with GNU grep (and could even be seen as contrary to the
448     pcregrep specification - which I improved to make it absolutely clear).
449     The action now is always to scan all levels of directory, and just
450     apply the include/exclude patterns to regular files.
451 ph10 345
452 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
453 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
454    
455 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
456 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
457 ph10 326 doesn't support NULs in patterns.
458 ph10 345
459     7. Added some missing "const"s to declarations of static tables in
460     pcre_compile.c and pcre_dfa_exec.c.
461    
462 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
463 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
464 ph10 345 first patch. And a third patch - this was a messy problem.)
465 ph10 321
466 ph10 345 9. Applied Craig's patch to remove the use of push_back().
467    
468 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
469     matching function regexec().
470 ph10 345
471     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
472     which, however, unlike Perl's \g{...}, are subroutine calls, not back
473 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
474     Oniguruma does).
475 ph10 345
476     12. Previously, a group with a zero repeat such as (...){0} was completely
477 ph10 335 omitted from the compiled regex. However, this means that if the group
478     was called as a subroutine from elsewhere in the pattern, things went wrong
479 ph10 345 (an internal error was given). Such groups are now left in the compiled
480     pattern, with a new opcode that causes them to be skipped at execution
481 ph10 335 time.
482 ph10 345
483 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
484     to the way PCRE behaves:
485 ph10 345
486 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
487 ph10 345
488     (b) A back reference to an unmatched subpattern matches an empty string
489 ph10 336 (Perl fails the current match path).
490 ph10 345
491 ph10 341 (c) A data ] in a character class must be notated as \] because if the
492 ph10 345 first data character in a class is ], it defines an empty class. (In
493 ph10 341 Perl it is not possible to have an empty class.) The empty class []
494     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
495     The negative empty class [^] matches any one character, independently
496     of the DOTALL setting.
497 ph10 345
498     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
499 ph10 340 non-existent subpattern following a character class starting with ']' and
500     containing () gave an internal compiling error instead of "reference to
501     non-existent subpattern". Fortunately, when the pattern did exist, the
502 ph10 345 compiled code was correct. (When scanning forwards to check for the
503 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
504 ph10 345 the class, so got the count wrong. When actually compiling, the reference
505 ph10 340 was subsequently set up correctly.)
506 ph10 345
507 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
508 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
509     other assertions are supported. I have made pcre_dfa_exec() support
510     (*FAIL).
511    
512 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
513 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
514     cannot be changed at match time, I realized I could make a small
515     improvement to matching performance by compiling OP_ALLANY instead of
516     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
517     on the OP_ANY path.
518    
519     17. Compiling pcretest on Windows with readline support failed without the
520 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
521 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
522    
523 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
524 ph10 345 ncurses library to be included for pcretest when ReadLine support is
525     requested, but also to allow for it to be overridden. This patch came from
526     Daniel Bergström.
527 ph10 347
528 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
529 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
530     any errors with the current Unicode tables. Thanks to Peter Kankowski for
531     spotting this.
532 ph10 324
533 ph10 332
534 ph10 319 Version 7.6 28-Jan-08
535 ph10 300 ---------------------
536    
537 ph10 302 1. A character class containing a very large number of characters with
538     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
539     overflow.
540 ph10 309
541     2. Patch to cut out the "long long" test in pcrecpp_unittest when
542     HAVE_LONG_LONG is not defined.
543    
544 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
545 ph10 304 bring them up to date and include new features. This patch includes:
546 ph10 309
547 ph10 304 - Fixed PH's badly added libz and libbz2 support.
548     - Fixed a problem with static linking.
549 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
550 ph10 304 - Fixed dftables problem and added an option.
551     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
552     HAVE_LONG_LONG.
553     - Added readline support for pcretest.
554 ph10 309 - Added an listing of the option settings after cmake has run.
555    
556 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
557     "pcre.dll" under mingw when using Configure/Make. I added stuff to
558     Makefile.am that cause it to include this special target, without
559     affecting anything else. Note that the same mingw target plus all
560     the other distribution libraries and programs are now supported
561     when configuring with CMake (see 6 below) instead of with
562     Configure/Make.
563 ph10 309
564 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
565     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
566 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
567     solves the problem, but it does no harm.
568 ph10 313
569 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
570 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
571 ph10 314 with CMake, and also correct the comment about stack recursion.
572 ph10 313
573 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
574 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
575     of a program that users should build themselves after PCRE is installed, so
576     building it automatically is not really right. What is more, it gave
577 ph10 312 trouble in some build environments.
578 ph10 300
579 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
580 ph10 308
581 ph10 319
582 ph10 298 Version 7.5 10-Jan-08
583 ph10 263 ---------------------
584    
585     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
586     values in parens when parsing an RE using the C++ wrapper."
587 ph10 286
588 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
589     Characters greater than 255 were excluded from the class instead of being
590     included.
591 ph10 286
592     3. The same bug as (2) above applied to negated POSIX classes such as
593 ph10 265 [:^space:].
594 ph10 286
595 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
596     defined or documented. It seems to have been a typo for PCRE_STATIC, so
597 ph10 286 I have changed it.
598    
599 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
600 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
601     first named subpattern whose name started with "a" (in other words, the
602 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
603     expected" is now given for (?&) (a zero-length name), and this patch also
604     makes it give the same error for \k'' (previously it complained that that
605     was a reference to a non-existent subpattern).
606 ph10 286
607 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
608 ph10 286 this is right because (?- can be followed by option settings as well as by
609 ph10 269 digits. I have, however, made the messages clearer.
610 ph10 286
611 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
612     than the number used in the conditional) now cause a compile-time error.
613     This is actually not compatible with Perl, which accepts such patterns, but
614     treats the conditional as always being FALSE (as PCRE used to), but it
615     seems to me that giving a diagnostic is better.
616 ph10 286
617 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
618 ph10 275 and messages.
619 ph10 286
620     9. Fix two occurrences of "backslash" in comments that should have been
621     "backspace".
622    
623     10. Remove two redundant lines of code that can never be obeyed (their function
624     was moved elsewhere).
625    
626     11. The program that makes PCRE's Unicode character property table had a bug
627     which caused it to generate incorrect table entries for sequences of
628 ph10 277 characters that have the same character type, but are in different scripts.
629 ph10 286 It amalgamated them into a single range, with the script of the first of
630 ph10 277 them. In other words, some characters were in the wrong script. There were
631     thirteen such cases, affecting characters in the following ranges:
632 ph10 286
633 ph10 277 U+002b0 - U+002c1
634     U+0060c - U+0060d
635 ph10 286 U+0061e - U+00612
636 ph10 277 U+0064b - U+0065e
637     U+0074d - U+0076d
638     U+01800 - U+01805
639     U+01d00 - U+01d77
640     U+01d9b - U+01dbf
641     U+0200b - U+0200f
642     U+030fc - U+030fe
643     U+03260 - U+0327f
644     U+0fb46 - U+0fbb1
645     U+10450 - U+1049d
646 ph10 286
647 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
648     compatible with GNU grep in that, if there was more than one match in a
649     line, it showed only the first of them. It now behaves in the same way as
650     GNU grep.
651 ph10 286
652     13. If the -o and -v options were combined for pcregrep, it printed a blank
653     line for every non-matching line. GNU grep prints nothing, and pcregrep now
654     does the same. The return code can be used to tell if there were any
655     non-matching lines.
656    
657 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
658    
659     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
660 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
661 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
662     and both kinds of lookbehind were skipped).
663    
664 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
665 ph10 284 inclusion of <windows.h> to before rather than after the definition of
666     INVALID_FILE_ATTRIBUTES (patch from David Byron).
667 ph10 263
668 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
669 ph10 286 character property caused pcre_compile() to compile bad code, which led at
670     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
671     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
672     caused the error; without that there was no problem.
673 ph10 263
674 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
675 ph10 286
676 ph10 289 19. Added --enable-pcretest-libreadline.
677 ph10 286
678 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
679 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
680 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
681     later patch that removed the other one (the right fix) and added unit tests
682     that check the return values (which was not done before).
683 ph10 292
684 ph10 291 21. Several CMake things:
685 ph10 287
686 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
687 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
688 ph10 288
689 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
690     linked with the newly-built libraries, not previously installed ones.
691 ph10 291
692 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
693 ph10 298
694     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
695     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
696     UTF-8 newline character). The key issue is that the pattern starts .*;
697     this means that the match must be either at the beginning, or after a
698     newline. The bug was in the code for advancing after a failed match and
699     checking that the new position followed a newline. It was not taking
700 ph10 294 account of UTF-8 characters correctly.
701 ph10 298
702     23. PCRE was behaving differently from Perl in the way it recognized POSIX
703     character classes. PCRE was not treating the sequence [:...:] as a
704     character class unless the ... were all letters. Perl, however, seems to
705     allow any characters between [: and :], though of course it rejects as
706     unknown any "names" that contain non-letters, because all the known class
707     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
708     for example, whereas PCRE did not - it did not recognize a POSIX character
709     class. This seemed a bit dangerous, so the code has been changed to be
710     closer to Perl. The behaviour is not identical to Perl, because PCRE will
711     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
712     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
713     Perl does, and where it didn't before.
714    
715 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
716     Windows environments %n is disabled by default.
717 ph10 292
718    
719 ph10 260 Version 7.4 21-Sep-07
720 ph10 230 ---------------------
721    
722     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
723 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
724     LF". That isn't really right - the whole point of the change was to try to
725     help when there was an actual mention of one of the two characters. So now
726     the change happens only if \r or \n (or a literal CR or LF) character is
727 ph10 230 encountered.
728 ph10 231
729     2. The 32-bit options word was also used for 6 internal flags, but the numbers
730     of both had grown to the point where there were only 3 bits left.
731     Fortunately, there was spare space in the data structure, and so I have
732     moved the internal flags into a new 16-bit field to free up more option
733 ph10 230 bits.
734 ph10 231
735     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
736     but did not set the internal JCHANGED flag - either of these is enough to
737     control the way the "get" function works - but the PCRE_INFO_JCHANGED
738     facility is supposed to tell if (?J) was ever used, so now (?J) at the
739 ph10 230 start sets both bits.
740    
741 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
742     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
743 ph10 230
744 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
745    
746     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
747 ph10 233 compatibility, even though it is no longer used.
748 ph10 243
749     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
750 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
751 ph10 259 windows.h file is present (where different names are used). [This was
752 ph10 257 reversed later after testing - see 16 below.]
753 ph10 243
754     8. Changed all #include <config.h> to #include "config.h". There were also
755 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
756 ph10 243
757 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
758 ph10 243 sequence off the lines that it output.
759    
760     10. It was pointed out to me that arrays of string pointers cause lots of
761     relocations when a shared library is dynamically loaded. A technique of
762     using a single long string with a table of offsets can drastically reduce
763     these. I have refactored PCRE in four places to do this. The result is
764 ph10 240 dramatic:
765 ph10 243
766 ph10 240 Originally: 290
767     After changing UCP table: 187
768 ph10 243 After changing error message table: 43
769 ph10 240 After changing table of "verbs" 36
770     After changing table of Posix names 22
771 ph10 243
772 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
773 ph10 247
774 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
775 ph10 247 unicode-properties was also set.
776    
777 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
778 ph10 231
779 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
780     checked only for CRLF.
781 ph10 233
782 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
783    
784 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
785 ph10 253
786 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
787 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
788     entirely. This removes changes made in 7 above.
789 ph10 256
790 ph10 261 17. The CMake files have been updated, and there is now more information about
791     building with CMake in the NON-UNIX-USE document.
792 ph10 257
793 ph10 261
794 ph10 228 Version 7.3 28-Aug-07
795 ph10 157 ---------------------
796    
797 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
798     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
799     brackets there is not right, since it causes compilers to look for an
800     installed pcre.h, not the version that is in the source that is being
801     compiled (which of course may be different). I have changed it back to:
802 ph10 197
803 ph10 189 #include "pcre.h"
804 ph10 197
805     I have a vague recollection that the change was concerned with compiling in
806     different directories, but in the new build system, that is taken care of
807     by the VPATH setting the Makefile.
808    
809 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
810     when the subject happened to end in the byte 0x85 (e.g. if the last
811     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
812     characters but of course it shouldn't be taken as a newline when it is part
813     of another character. The bug was that, for an unlimited repeat of . in
814     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
815     characters when looking for a newline.
816 ph10 197
817     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
818    
819     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
820     in debug output.
821    
822 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
823     long printing in the pcrecpp unittest when running under MinGW.
824 ph10 189
825 ph10 197 6. ESC_K was left out of the EBCDIC table.
826 ph10 189
827 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
828     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
829     limit also applies to "virtual nesting" when a pattern is recursive, and in
830     this case 1000 isn't so big. I have been able to remove this limit at the
831     expense of backing off one optimization in certain circumstances. Normally,
832     when pcre_exec() would call its internal match() function recursively and
833     immediately return the result unconditionally, it uses a "tail recursion"
834     feature to save stack. However, when a subpattern that can match an empty
835     string has an unlimited repetition quantifier, it no longer makes this
836     optimization. That gives it a stack frame in which to save the data for
837     checking that an empty string has been matched. Previously this was taken
838     from the 1000-entry workspace that had been reserved. So now there is no
839     explicit limit, but more stack is used.
840 ph10 189
841 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
842     syntax that is required for Windows, and which was going wrong for the
843     pcreposix and pcrecpp parts of the library. These were overlooked when this
844     problem was solved for the main library.
845 ph10 197
846 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
847     the size of patterns that contain repeated groups with explicit upper
848     limits. As the maximum quantifier is 65535, the maximum group length was
849     set at 30,000 so that the product of these two numbers did not overflow a
850     32-bit integer. However, it turns out that people want to use groups that
851     are longer than 30,000 bytes (though not repeat them that many times).
852     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
853     made it possible to implement the integer overflow checks in a much more
854     dynamic way, which I have now done. The artificial limitation on group
855     length has been removed - we now have only the limit on the total length of
856     the compiled pattern, which depends on the LINK_SIZE setting.
857 ph10 208
858     10. Fixed a bug in the documentation for get/copy named substring when
859     duplicate names are permitted. If none of the named substrings are set, the
860     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
861     empty string.
862    
863     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
864     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
865     because the ] is interpreted as the first data character and the
866     terminating ] is not found. PCRE has been made compatible with Perl in this
867     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
868     cause memory overwriting.
869    
870 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
871     string has been matched (to stop an infinite loop). It was not recognizing
872 ph10 208 a conditional subpattern that could match an empty string if that
873 ph10 206 subpattern was within another subpattern. For example, it looped when
874 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
875 ph10 206 condition was not nested. This bug has been fixed.
876 ph10 208
877 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
878     past the start of the subject in the presence of bytes with the top bit
879     set, for example "\x8aBCD".
880 ph10 211
881 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
882     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
883 ph10 200
884 ph10 211 14. Optimized (?!) to (*FAIL).
885 ph10 202
886 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
887     This restricts code points to be within the range 0 to 0x10FFFF, excluding
888     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
889     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
890     does: it's just the validity check that is more restrictive.
891 ph10 220
892     16. Inserted checks for integer overflows during escape sequence (backslash)
893     processing, and also fixed erroneous offset values for syntax errors during
894     backslash processing.
895    
896 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
897 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
898    
899 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
900     caused an overrun.
901 ph10 220
902     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
903     something other than just ASCII characters) inside a group that had an
904     unlimited repeat caused a loop at compile time (while checking to see
905     whether the group could match an empty string).
906    
907 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
908     [\P{Any}] did so. (Error in the code for printing property names.)
909 ph10 210
910 ph10 220 21. An orphan \E inside a character class could cause a crash.
911    
912     22. A repeated capturing bracket such as (A)? could cause a wild memory
913 ph10 218 reference during compilation.
914 ph10 220
915     23. There are several functions in pcre_compile() that scan along a compiled
916     expression for various reasons (e.g. to see if it's fixed length for look
917 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
918 ph10 220 present in the pattern. These operators have additional parameters compared
919     with \d, etc, and these were not being taken into account when moving along
920 ph10 218 the compiled data. Specifically:
921 ph10 220
922     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
923     length.
924    
925     (b) An item such as \pL+ within a repeated group could cause crashes or
926 ph10 218 loops.
927 ph10 220
928 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
929 ph10 220 "reference to non-existent subpattern" error.
930    
931 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
932    
933 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
934 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
935 ph10 211
936 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
937 ph10 218
938 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
939 ph10 223 character were causing crashes (broken optimization).
940 ph10 227
941 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
942 ph10 227 \p or \P) caused a compile-time loop.
943    
944 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
945     break. For example, the unstudied pattern [\r\n]A does not match the string
946     "\r\nA" because change 7.0/46 below moves the current point on by two
947     characters after failing to match at the start. However, the pattern \nA
948 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
949     the same is true. There doesn't seem any very clean way out of this, but
950     what I have chosen to do makes the common cases work: PCRE now takes note
951     of whether there can be an explicit match for \r or \n anywhere in the
952     pattern, and if so, 7.0/46 no longer applies. As part of this change,
953     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
954     pattern has explicit CR or LF references.
955 ph10 222
956 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
957 ph10 223
958 ph10 227
959 ph10 189 Version 7.2 19-Jun-07
960     ---------------------
961    
962 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
963     which is apparently normally available under Windows.
964 ph10 159
965     2. Re-jig the pcregrep tests with different newline settings in an attempt
966     to make them independent of the local environment's newline setting.
967 ph10 157
968 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
969 ph10 165
970 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
971     was not 2, because the output contained actual offsets. The recent new
972 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
973     usable with all link sizes.
974    
975 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
976     stack recursion. This gives a massive performance boost under BSD, but just
977 ph10 165 a small improvement under Linux. However, it saves one field in the frame
978 ph10 164 in all cases.
979 ph10 172
980 ph10 166 6. Added more features from the forthcoming Perl 5.10:
981 ph10 172
982 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
983     recursion call. It refers to the nth most recently opened parentheses.
984 ph10 172
985 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
986 ph10 172 to be opened parentheses.
987    
988     (c) Conditions that refer to capturing parentheses can be specified
989 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
990 ph10 172
991 ph10 168 (d) \K resets the start of the current match so that everything before
992 ph10 172 is not part of it.
993    
994 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
995 ph10 172
996 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
997 ph10 172 reference syntax.
998 ph10 182
999 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1000 ph10 182 alternative starts with the same number.
1001 ph10 172
1002 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1003    
1004 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1005     PCRE_INFO_JCHANGED.
1006    
1007     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1008     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1009 ph10 170 for detecting groups that can match an empty string.
1010 ph10 159
1011 ph10 172 9. A pattern with a very large number of alternatives (more than several
1012     hundred) was running out of internal workspace during the pre-compile
1013     phase, where pcre_compile() figures out how much memory will be needed. A
1014     bit of new cunning has reduced the workspace needed for groups with
1015     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1016     workspace instead of running out of the 4096 that are available.
1017 ph10 182
1018 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1019 ph10 172
1020 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1021     The report of the bug said:
1022 ph10 182
1023 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1024     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1025 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1026 ph10 185
1027 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1028 ph10 185 it matched the wrong number of bytes.
1029 ph10 172
1030 ph10 179
1031 ph10 155 Version 7.1 24-Apr-07
1032 ph10 98 ---------------------
1033    
1034 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1035 ph10 122 that is more "standard", making use of automake and other Autotools. There
1036 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1037     on this.
1038 ph10 111
1039     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1040     for recursive directory scanning broke on some systems because the files
1041     are not scanned in any specific order and on different systems the order
1042     was different. A call to "sort" has been inserted into RunGrepTest for the
1043     approprate test as a short-term fix. In the longer term there may be an
1044 ph10 100 alternative.
1045 ph10 111
1046 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1047 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1048     people do their own conversions for various reasons). The problems
1049     concerned the use of low-level troff macros .br and .in. I have therefore
1050     removed all such uses from the man pages (some were redundant, some could
1051 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1052     HTML has been updated to handle .nf/.fi and to complain if it encounters
1053     .br or .in.
1054 ph10 111
1055 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1056 ph10 123 arranged for config.h to be included in the distribution, with the name
1057 ph10 111 config.h.generic, for the benefit of those who have to compile without
1058     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1059    
1060     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1061     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1062 ph10 127 makevp.bat for the current PCRE, using the additional files
1063 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1064 ph10 111
1065     6. A Windows user reported a minor discrepancy with test 2, which turned out
1066     to be caused by a trailing space on an input line that had got lost in his
1067 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1068 ph10 111
1069 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1070 ph10 111 that is needed.
1071    
1072 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1073     as "const" (a) because they are and (b) because it helps the PHP
1074     maintainers who have recently made a script to detect big data structures
1075 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1076     to update Builducptable as well, so it won't revert if ucptable.h is ever
1077 ph10 105 re-created.
1078 ph10 111
1079     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1080 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1081 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1082     support is not required. This saves 1.5-2K of code, which is important in
1083 ph10 107 some applications.
1084 ph10 111
1085 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1086 ph10 111 so as not to refer to the tables, even though these functions will never be
1087     called when UTF-8 support is disabled. Otherwise there are problems with a
1088     shared library.
1089    
1090 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1091    
1092     (a) It was defining its arguments as char * instead of void *.
1093    
1094 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1095     a long time ago when I wrote it, but is no longer the case.
1096    
1097 ph10 118 The emulated memove() is provided for those environments that have neither
1098 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1099 ph10 118 is clearly not the case, as these two bugs were recently reported.
1100 ph10 123
1101 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1102 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1103     pages, and it removes trailing spaces from listed files. It also creates
1104     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1105     case, it wraps all the #defines with #ifndefs. This script should be run
1106 ph10 111 before "make dist".
1107 ph10 123
1108 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1109     with Unicode property support.
1110 ph10 123
1111     (a) For a maximizing quantifier, if the two different cases of the
1112     character were of different lengths in their UTF-8 codings (there are
1113     some cases like this - I found 11), and the matching function had to
1114 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1115     were both the same length.
1116 ph10 123
1117     (b) When PCRE was configured to use the heap rather than the stack for
1118     recursion during matching, it was not correctly preserving the data for
1119     the other case of a UTF-8 character when checking ahead for a match
1120     while processing a minimizing repeat. If the check also involved
1121 ph10 115 matching a wide character, but failed, corruption could cause an
1122     erroneous result when trying to check for a repeat of the original
1123     character.
1124 ph10 123
1125 ph10 116 13. Some tidying changes to the testing mechanism:
1126 ph10 98
1127 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1128     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1129 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1130     this for UTF-8.) The configure.ac script no longer substitutes the
1131     relevant variables.
1132    
1133 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1134     with length and offset values. This means that the output is different
1135     for different internal link sizes. Test 2 is skipped for link sizes
1136     other than 2 because of this, bypassing the problem. Unfortunately,
1137     there was also a test in test 3 (the locale tests) that used /B and
1138 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1139     I have added a new /Z option to pcretest that replaces the length and
1140     offset values with spaces. This is now used to make test 3 independent
1141 ph10 122 of link size. (Test 2 will be tidied up later.)
1142 ph10 123
1143     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1144 ph10 122 segmentation fault instead of returning the appropriate error message.
1145 ph10 134
1146 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1147 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1148     This doesn't seem right; it now treats the CRLF combination as the line
1149     ending, and so does not match in that case. It's only a pattern such as ^$
1150     that would hit this one: something like ^ABC$ would have failed after \r
1151     and then tried again after \r\n.
1152    
1153 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1154 ph10 134 in an attempt to make files that differ only in their line terminators
1155     compare equal. This works on Linux.
1156 ph10 142
1157 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1158     as it exited. This is now fixed, thanks to valgrind.
1159 ph10 142
1160 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1161 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1162     was because its rules for how to advance for /g after matching an empty
1163 ph10 143 string at the end of a line did not allow for this case. They now check for
1164     it specially.
1165 ph10 150
1166     20. pcretest is supposed to handle patterns and data of any length, by
1167     extending its buffers when necessary. It was getting this wrong when the
1168 ph10 147 buffer for a data line had to be extended.
1169 ph10 150
1170 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1171 ph10 150 CRLF as a newline sequence.
1172 ph10 152
1173 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1174 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1175     I have nevertheless tidied it up.
1176 ph10 111
1177 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1178 ph10 123
1179 ph10 153 24. Added a man page for pcre-config.
1180 ph10 152
1181 ph10 153
1182 nigel 93 Version 7.0 19-Dec-06
1183     ---------------------
1184    
1185     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1186     moving to gcc 4.1.1.
1187    
1188     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1189     sys/time.h, which is documented as needed for this function. It doesn't
1190     seem to matter on Linux, but it showed up on some releases of OS X.
1191    
1192     3. It seems that there are systems where bytes whose values are greater than
1193     127 match isprint() in the "C" locale. The "C" locale should be the
1194     default when a C program starts up. In most systems, only ASCII printing
1195     characters match isprint(). This difference caused the output from pcretest
1196     to vary, making some of the tests fail. I have changed pcretest so that:
1197    
1198     (a) When it is outputting text in the compiled version of a pattern, bytes
1199     other than 32-126 are always shown as hex escapes.
1200    
1201     (b) When it is outputting text that is a matched part of a subject string,
1202     it does the same, unless a different locale has been set for the match
1203     (using the /L modifier). In this case, it uses isprint() to decide.
1204    
1205     4. Fixed a major bug that caused incorrect computation of the amount of memory
1206     required for a compiled pattern when options that changed within the
1207     pattern affected the logic of the preliminary scan that determines the
1208     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1209     that the computed length was too small. The symptoms of this bug were
1210     either the PCRE error "internal error: code overflow" from pcre_compile(),
1211     or a glibc crash with a message such as "pcretest: free(): invalid next
1212     size (fast)". Examples of patterns that provoked this bug (shown in
1213     pcretest format) are:
1214    
1215     /(?-x: )/x
1216     /(?x)(?-x: \s*#\s*)/
1217     /((?i)[\x{c0}])/8
1218     /(?i:[\x{c0}])/8
1219    
1220     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1221     is now done differently.
1222    
1223     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1224     wrapper classes; (b) implement a new function in the C++ scanner that is
1225     more efficient than the old way of doing things because it avoids levels of
1226     recursion in the regex matching; (c) add a paragraph to the documentation
1227     for the FullMatch() function.
1228    
1229     6. The escape sequence \n was being treated as whatever was defined as
1230     "newline". Not only was this contrary to the documentation, which states
1231     that \n is character 10 (hex 0A), but it also went horribly wrong when
1232     "newline" was defined as CRLF. This has been fixed.
1233    
1234     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1235     was being set to -1 for the "end of line" case (supposedly a value that no
1236     character can have). Though this value is never used (the check for end of
1237     line is "zero bytes in current character"), it caused compiler complaints.
1238     I've changed it to 0xffffffff.
1239    
1240     8. In pcre_version.c, the version string was being built by a sequence of
1241     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1242     string (as it is for production releases) called a macro with an empty
1243     argument. The C standard says the result of this is undefined. The gcc
1244     compiler treats it as an empty string (which was what was wanted) but it is
1245     reported that Visual C gives an error. The source has been hacked around to
1246     avoid this problem.
1247    
1248     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1249     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1250     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1251     of them did).
1252    
1253     10. Originally, pcretest opened its input and output without "b"; then I was
1254     told that "b" was needed in some environments, so it was added for release
1255     5.0 to both the input and output. (It makes no difference on Unix-like
1256     systems.) Later I was told that it is wrong for the input on Windows. I've
1257     now abstracted the modes into two macros, to make it easier to fiddle with
1258     them, and removed "b" from the input mode under Windows.
1259    
1260     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1261    
1262     12. Added -help and --help to pcretest as an official way of being reminded
1263     of the options.
1264    
1265     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1266     and pcrecpp.cc because they annoy compilers at high warning levels.
1267    
1268     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1269    
1270     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1271     scripts are not C programs :-) and which was not noticed because it works
1272     on Linux.
1273    
1274     16. pcretest is supposed to handle any length of pattern and data line (as one
1275     line or as a continued sequence of lines) by extending its input buffer if
1276     necessary. This feature was broken for very long pattern lines, leading to
1277     a string of junk being passed to pcre_compile() if the pattern was longer
1278     than about 50K.
1279    
1280     17. I have done a major re-factoring of the way pcre_compile() computes the
1281     amount of memory needed for a compiled pattern. Previously, there was code
1282     that made a preliminary scan of the pattern in order to do this. That was
1283     OK when PCRE was new, but as the facilities have expanded, it has become
1284     harder and harder to keep it in step with the real compile phase, and there
1285     have been a number of bugs (see for example, 4 above). I have now found a
1286     cunning way of running the real compile function in a "fake" mode that
1287     enables it to compute how much memory it would need, while actually only
1288     ever using a few hundred bytes of working memory and without too many
1289     tests of the mode. This should make future maintenance and development
1290     easier. A side effect of this work is that the limit of 200 on the nesting
1291     depth of parentheses has been removed (though this was never a serious
1292     limitation, I suspect). However, there is a downside: pcre_compile() now
1293     runs more slowly than before (30% or more, depending on the pattern). I
1294     hope this isn't a big issue. There is no effect on runtime performance.
1295    
1296     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1297     newline (only possible for the last line of a file) and it was a
1298     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1299    
1300     19. Added additional timing features to pcretest. (1) The -tm option now times
1301     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1302     separate command line item, by a number that specifies the number of
1303     repeats to use when timing. The default is 50000; this gives better
1304     precision, but takes uncomfortably long for very large patterns.
1305    
1306     20. Extended pcre_study() to be more clever in cases where a branch of a
1307     subpattern has no definite first character. For example, (a*|b*)[cd] would
1308     previously give no result from pcre_study(). Now it recognizes that the
1309     first character must be a, b, c, or d.
1310    
1311     21. There was an incorrect error "recursive call could loop indefinitely" if
1312     a subpattern (or the entire pattern) that was being tested for matching an
1313     empty string contained only one non-empty item after a nested subpattern.
1314     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1315     incorrectly, because the \d was being skipped in the check.
1316    
1317     22. The pcretest program now has a new pattern option /B and a command line
1318     option -b, which is equivalent to adding /B to every pattern. This causes
1319     it to show the compiled bytecode, without the additional information that
1320     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1321     is the same as /B/I).
1322    
1323     23. A new optimization is now able automatically to treat some sequences such
1324     as a*b as a*+b. More specifically, if something simple (such as a character
1325     or a simple class like \d) has an unlimited quantifier, and is followed by
1326     something that cannot possibly match the quantified thing, the quantifier
1327     is automatically "possessified".
1328    
1329     24. A recursive reference to a subpattern whose number was greater than 39
1330     went wrong under certain circumstances in UTF-8 mode. This bug could also
1331     have affected the operation of pcre_study().
1332    
1333     25. Realized that a little bit of performance could be had by replacing
1334     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1335    
1336     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1337    
1338     27. Possessive quantifiers such as a++ were previously implemented by turning
1339     them into atomic groups such as ($>a+). Now they have their own opcodes,
1340     which improves performance. This includes the automatically created ones
1341     from 23 above.
1342    
1343     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1344     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1345     the first matched character to be a colon. This applied both to named and
1346     numbered groups.
1347    
1348     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1349    
1350     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1351     building PCRE on Windows easier, so I have included it in the distribution.
1352    
1353     31. There is now a check in pcretest against a ridiculously large number being
1354     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1355     loop, the loop is abandoned.
1356    
1357     32. Forward references to subpatterns in conditions such as (?(2)...) where
1358     subpattern 2 is defined later cause pcre_compile() to search forwards in
1359     the pattern for the relevant set of parentheses. This search went wrong
1360     when there were unescaped parentheses in a character class, parentheses
1361     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1362    
1363     33. "Subroutine" calls and backreferences were previously restricted to
1364     referencing subpatterns earlier in the regex. This restriction has now
1365     been removed.
1366    
1367     34. Added a number of extra features that are going to be in Perl 5.10. On the
1368     whole, these are just syntactic alternatives for features that PCRE had
1369     previously implemented using the Python syntax or my own invention. The
1370     other formats are all retained for compatibility.
1371    
1372     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1373     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1374     also .NET compatible.
1375    
1376     (b) A recursion or subroutine call to a named group can now be defined as
1377     (?&name) as well as (?P>name).
1378    
1379     (c) A backreference to a named group can now be defined as \k<name> or
1380     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1381     5.10, are also .NET compatible.
1382    
1383     (d) A conditional reference to a named group can now use the syntax
1384     (?(<name>) or (?('name') as well as (?(name).
1385    
1386     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1387     groups (named and numbered) that are never evaluated inline, but can be
1388     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1389     is always false. There may be only one alternative in such a group.
1390    
1391     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1392     as the simple (?(R). The condition is true only if the most recent
1393     recursion is that of the given number or name. It does not search out
1394     through the entire recursion stack.
1395    
1396     (g) The escape \gN or \g{N} has been added, where N is a positive or
1397     negative number, specifying an absolute or relative reference.
1398    
1399     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1400     some "unreachable code" warnings.
1401    
1402     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1403     things, this adds five new scripts.
1404    
1405     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1406     There were also incompatibilities regarding the handling of \Q..\E inside
1407     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1408     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1409    
1410     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1411     matches an empty string, and forcibly breaks the loop. There were bugs in
1412     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1413     against aaaa the result was just "a" rather than "aaaa", for example. Two
1414     separate and independent bugs (that affected different cases) have been
1415     fixed.
1416    
1417     39. Refactored the code to abolish the use of different opcodes for small
1418     capturing bracket numbers. This is a tidy that I avoided doing when I
1419     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1420     The new approach is not only tidier, it makes it possible to reduce the
1421     memory needed to fix the previous bug (38).
1422    
1423     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1424     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1425     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1426     mode.
1427    
1428     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1429     report.
1430    
1431     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1432     copy construction and assignment in the C++ wrapper.
1433    
1434     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1435     couple of bugs that could have given wrong results in the "--newline=crlf"
1436     case.
1437    
1438     44. Added a number of casts and did some reorganization of signed/unsigned int
1439     variables following suggestions from Dair Grant. Also renamed the variable
1440     "this" as "item" because it is a C++ keyword.
1441    
1442     45. Arranged for dftables to add
1443    
1444     #include "pcre_internal.h"
1445    
1446     to pcre_chartables.c because without it, gcc 4.x may remove the array
1447     definition from the final binary if PCRE is built into a static library and
1448     dead code stripping is activated.
1449    
1450     46. For an unanchored pattern, if a match attempt fails at the start of a
1451     newline sequence, and the newline setting is CRLF or ANY, and the next two
1452     characters are CRLF, advance by two characters instead of one.
1453    
1454    
1455 nigel 91 Version 6.7 04-Jul-06
1456     ---------------------
1457    
1458     1. In order to handle tests when input lines are enormously long, pcretest has
1459     been re-factored so that it automatically extends its buffers when
1460     necessary. The code is crude, but this _is_ just a test program. The
1461     default size has been increased from 32K to 50K.
1462    
1463     2. The code in pcre_study() was using the value of the re argument before
1464     testing it for NULL. (Of course, in any sensible call of the function, it
1465     won't be NULL.)
1466    
1467     3. The memmove() emulation function in pcre_internal.h, which is used on
1468     systems that lack both memmove() and bcopy() - that is, hardly ever -
1469     was missing a "static" storage class specifier.
1470    
1471     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1472     containing an extended class (one that cannot be represented by a bitmap
1473     because it contains high-valued characters or Unicode property items, e.g.
1474     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1475     pattern, but PCRE should not loop if you do not (it no longer does).
1476     [Detail: two cases were found: (a) a repeated subpattern containing an
1477     extended class; (b) a recursive reference to a subpattern that followed a
1478     previous extended class. It wasn't skipping over the extended class
1479     correctly when UTF-8 mode was not set.]
1480    
1481     5. A negated single-character class was not being recognized as fixed-length
1482     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1483     compile error "lookbehind assertion is not fixed length".
1484    
1485     6. The RunPerlTest auxiliary script was showing an unexpected difference
1486     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1487     write a Perl script that can interpret lines of an input file either as
1488     byte characters or as UTF-8, which is what "perltest" was being required to
1489     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1490     can't do is switch easily at run time between having the "use utf8;" pragma
1491     or not. In the end, I fudged it by using the RunPerlTest script to insert
1492     "use utf8;" explicitly for the UTF-8 tests.
1493    
1494     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1495     the end of the subject string, contrary to the documentation and to what
1496     Perl does. This was true of both matching functions. Now it matches only at
1497     the start of the subject and immediately after *internal* newlines.
1498    
1499     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1500     a pointer to an int instead of a pointer to an unsigned long int. This
1501     caused problems on 64-bit systems.
1502    
1503     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1504     instance of the 'standard' template library not being so standard".
1505    
1506     10. There was no check on the number of named subpatterns nor the maximum
1507     length of a subpattern name. The product of these values is used to compute
1508     the size of the memory block for a compiled pattern. By supplying a very
1509     long subpattern name and a large number of named subpatterns, the size
1510     computation could be caused to overflow. This is now prevented by limiting
1511     the length of names to 32 characters, and the number of named subpatterns
1512     to 10,000.
1513    
1514     11. Subpatterns that are repeated with specific counts have to be replicated in
1515     the compiled pattern. The size of memory for this was computed from the
1516     length of the subpattern and the repeat count. The latter is limited to
1517     65535, but there was no limit on the former, meaning that integer overflow
1518     could in principle occur. The compiled length of a repeated subpattern is
1519     now limited to 30,000 bytes in order to prevent this.
1520    
1521     12. Added the optional facility to have named substrings with the same name.
1522    
1523     13. Added the ability to use a named substring as a condition, using the
1524     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1525     are numbers (not recommended). Forward references are permitted.
1526    
1527     14. Added forward references in named backreferences (if you see what I mean).
1528    
1529     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1530     pattern could run off the end of the subject. For example, the pattern
1531     "(?s)(.{1,5})"8 did this with the subject "ab".
1532    
1533     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1534     PCRE_CASELESS was set when matching characters that were quantified with ?
1535     or *.
1536    
1537     17. A character class other than a single negated character that had a minimum
1538     but no maximum quantifier - for example [ab]{6,} - was not handled
1539     correctly by pce_dfa_exec(). It would match only one character.
1540    
1541     18. A valid (though odd) pattern that looked like a POSIX character
1542     class but used an invalid character after [ (for example [[,abc,]]) caused
1543     pcre_compile() to give the error "Failed: internal error: code overflow" or
1544     in some cases to crash with a glibc free() error. This could even happen if
1545     the pattern terminated after [[ but there just happened to be a sequence of
1546     letters, a binary zero, and a closing ] in the memory that followed.
1547    
1548     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1549     over the years. Originally (before any Unicode support), just the bottom 8
1550     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1551     output from "man perlunicode" includes this:
1552    
1553     The regular expression compiler produces polymorphic opcodes. That
1554     is, the pattern adapts to the data and automatically switches to
1555     the Unicode character scheme when presented with Unicode data--or
1556     instead uses a traditional byte scheme when presented with byte
1557     data.
1558    
1559     Sadly, a wide octal escape does not cause a switch, and in a string with
1560     no other multibyte characters, these octal escapes are treated as before.
1561     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1562     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1563     Unicode string.
1564    
1565     I have not perpetrated such confusion in PCRE. Up till now, it took just
1566     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1567     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1568     translate to the appropriate multibyte character.
1569    
1570     29. Applied some refactoring to reduce the number of warnings from Microsoft
1571     and Borland compilers. This has included removing the fudge introduced
1572     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1573     a warning about an unused variable.
1574    
1575     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1576     characters since release 4.0, because Perl (from release 5.004) does not.
1577     [Or at least, is documented not to: some releases seem to be in conflict
1578     with the documentation.] However, when a pattern was studied with
1579     pcre_study() and all its branches started with \s, PCRE still included VT
1580     as a possible starting character. Of course, this did no harm; it just
1581     caused an unnecessary match attempt.
1582    
1583     22. Removed a now-redundant internal flag bit that recorded the fact that case
1584     dependency changed within the pattern. This was once needed for "required
1585     byte" processing, but is no longer used. This recovers a now-scarce options
1586     bit. Also moved the least significant internal flag bit to the most-
1587     significant bit of the word, which was not previously used (hangover from
1588     the days when it was an int rather than a uint) to free up another bit for
1589     the future.
1590    
1591     23. Added support for CRLF line endings as well as CR and LF. As well as the
1592     default being selectable at build time, it can now be changed at runtime
1593     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1594     specify that it is scanning data with non-default line endings.
1595    
1596     24. Changed the definition of CXXLINK to make it agree with the definition of
1597     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1598    
1599     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1600     recursions. This makes a big different to stack usage for some patterns.
1601    
1602     26. If a subpattern containing a named recursion or subroutine reference such
1603     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1604     the space required for the compiled pattern went wrong and gave too small a
1605     value. Depending on the environment, this could lead to "Failed: internal
1606     error: code overflow at offset 49" or "glibc detected double free or
1607     corruption" errors.
1608    
1609     27. Applied patches from Google (a) to support the new newline modes and (b) to
1610     advance over multibyte UTF-8 characters in GlobalReplace.
1611    
1612     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1613     difference for some implementation of PCRE in some Windows version.
1614    
1615     29. Added some extra testing facilities to pcretest:
1616    
1617     \q<number> in a data line sets the "match limit" value
1618     \Q<number> in a data line sets the "match recursion limt" value
1619     -S <number> sets the stack size, where <number> is in megabytes
1620    
1621     The -S option isn't available for Windows.
1622    
1623    
1624 nigel 89 Version 6.6 06-Feb-06
1625     ---------------------
1626    
1627     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1628     in pcreposix.h. I have copied the definition from pcre.h.
1629    
1630     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1631     because pcre.h is no longer a built file.
1632    
1633     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1634     not normally included in the compiled code.
1635    
1636    
1637 nigel 87 Version 6.5 01-Feb-06
1638     ---------------------
1639    
1640     1. When using the partial match feature with pcre_dfa_exec(), it was not
1641     anchoring the second and subsequent partial matches at the new starting
1642     point. This could lead to incorrect results. For example, with the pattern
1643     /1234/, partially matching against "123" and then "a4" gave a match.
1644    
1645     2. Changes to pcregrep:
1646    
1647     (a) All non-match returns from pcre_exec() were being treated as failures
1648     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1649     error message is output. Some extra information is given for the
1650     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1651     probably the only errors that are likely to be caused by users (by
1652     specifying a regex that has nested indefinite repeats, for instance).
1653     If there are more than 20 of these errors, pcregrep is abandoned.
1654    
1655     (b) A binary zero was treated as data while matching, but terminated the
1656     output line if it was written out. This has been fixed: binary zeroes
1657     are now no different to any other data bytes.
1658    
1659     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1660     used to set a locale for matching. The --locale=xxxx long option has
1661     been added (no short equivalent) to specify a locale explicitly on the
1662     pcregrep command, overriding the environment variables.
1663    
1664     (d) When -B was used with -n, some line numbers in the output were one less
1665     than they should have been.
1666    
1667     (e) Added the -o (--only-matching) option.
1668    
1669     (f) If -A or -C was used with -c (count only), some lines of context were
1670     accidentally printed for the final match.
1671    
1672     (g) Added the -H (--with-filename) option.
1673    
1674     (h) The combination of options -rh failed to suppress file names for files
1675     that were found from directory arguments.
1676    
1677     (i) Added the -D (--devices) and -d (--directories) options.
1678    
1679     (j) Added the -F (--fixed-strings) option.
1680    
1681     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1682    
1683     (l) Added the --colo(u)r option.
1684    
1685     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1686     is not present by default.
1687    
1688     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1689     items such as (?R) or (?1), when the recursion could match a number of
1690     alternatives. If it matched one of the alternatives, but subsequently,
1691     outside the recursion, there was a failure, the code tried to back up into
1692     the recursion. However, because of the way PCRE is implemented, this is not
1693     possible, and the result was an incorrect result from the match.
1694    
1695     In order to prevent this happening, the specification of recursion has
1696     been changed so that all such subpatterns are automatically treated as
1697     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1698    
1699     4. I had overlooked the fact that, in some locales, there are characters for
1700     which isalpha() is true but neither isupper() nor islower() are true. In
1701     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1702     and ordfeminine) are like this. This affected the treatment of \w and \W
1703     when they appeared in character classes, but not when they appeared outside
1704     a character class. The bit map for "word" characters is now created
1705     separately from the results of isalnum() instead of just taking it from the
1706     upper, lower, and digit maps. (Plus the underscore character, of course.)
1707    
1708     5. The above bug also affected the handling of POSIX character classes such as
1709     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1710     permanent tables. Instead, the bit maps for such a class were previously
1711     created as the appropriate unions of the upper, lower, and digit bitmaps.
1712     Now they are created by subtraction from the [[:word:]] class, which has
1713     its own bitmap.
1714    
1715     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1716     It is created by subtracting the vertical space characters (\x09, \x0a,
1717     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1718     subtraction was done in the overall bitmap for a character class, meaning
1719     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1720     be recognized. This bug has been fixed.
1721    
1722     7. Patches from the folks at Google:
1723    
1724     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1725     real life, but is still worth protecting against".
1726    
1727     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1728     regular expressions".
1729    
1730     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1731     have it.
1732    
1733     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1734     "configure" and the latter not, in order to fix a problem somebody had
1735     with compiling the Arg class on HP-UX.
1736    
1737     (e) Improve the error-handling of the C++ wrapper a little bit.
1738    
1739     (f) New tests for checking recursion limiting.
1740    
1741     8. The pcre_memmove() function, which is used only if the environment does not
1742     have a standard memmove() function (and is therefore rarely compiled),
1743     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1744     returning a result (though PCRE never actually uses the result).
1745    
1746     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1747     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1748     returned instead of calling malloc() with an overflowing number that would
1749     most likely cause subsequent chaos.
1750    
1751     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1752    
1753     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1754     with this option is matched, the nmatch and pmatch options of regexec() are
1755     ignored.
1756    
1757     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1758     provided in case anyone wants to the the POSIX interface with UTF-8
1759     strings.
1760    
1761     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1762     C++ linking (needed for some HP-UX environments).
1763    
1764     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1765     (unused parameter) and in the pcre_printint() function (omitted "default"
1766     switch label when the default is to do nothing).
1767    
1768     15. Added some code to make it possible, when PCRE is compiled as a C++
1769     library, to replace subject pointers for pcre_exec() with a smart pointer
1770     class, thus making it possible to process discontinuous strings.
1771    
1772     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1773     much the same function. They were added by different people who were trying
1774     to make PCRE easy to compile on non-Unix systems. It has been suggested
1775     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1776     for compiling on Windows systems. I have therefore replaced it with
1777     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1778     defaults to "extern" for C or "extern C" for C++, which works fine on
1779     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1780     SCOPE with something explicit in config.h. In addition:
1781    
1782     (a) pcreposix.h still had just "extern" instead of either of these macros;
1783     I have replaced it with PCRE_DATA_SCOPE.
1784    
1785     (b) Functions such as _pcre_xclass(), which are internal to the library,
1786     but external in the C sense, all had PCRE_EXPORT in their definitions.
1787     This is apparently wrong for the Windows case, so I have removed it.
1788     (It makes no difference on Unix-like systems.)
1789    
1790     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1791     of recursive calls to match(). This is different to MATCH_LIMIT because
1792     that limits the total number of calls to match(), not all of which increase
1793     the depth of recursion. Limiting the recursion depth limits the amount of
1794     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1795     when PCRE is compiled, and changed at run time. A patch from Google adds
1796     this functionality to the C++ interface.
1797    
1798     18. Changes to the handling of Unicode character properties:
1799    
1800     (a) Updated the table to Unicode 4.1.0.
1801    
1802     (b) Recognize characters that are not in the table as "Cn" (undefined).
1803    
1804     (c) I revised the way the table is implemented to a much improved format
1805     which includes recognition of ranges. It now supports the ranges that
1806     are defined in UnicodeData.txt, and it also amalgamates other
1807     characters into ranges. This has reduced the number of entries in the
1808     table from around 16,000 to around 3,000, thus reducing its size
1809     considerably. I realized I did not need to use a tree structure after
1810     all - a binary chop search is just as efficient. Having reduced the
1811     number of entries, I extended their size from 6 bytes to 8 bytes to
1812     allow for more data.
1813    
1814     (d) Added support for Unicode script names via properties such as \p{Han}.
1815    
1816     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1817     matching that character.
1818    
1819     20. When matching a repeated Unicode property with a minimum greater than zero,
1820     (for example \pL{2,}), PCRE could look past the end of the subject if it
1821     reached it while seeking the minimum number of characters. This could
1822     happen only if some of the characters were more than one byte long, because
1823     there is a check for at least the minimum number of bytes.
1824    
1825     21. Refactored the implementation of \p and \P so as to be more general, to
1826     allow for more different types of property in future. This has changed the
1827     compiled form incompatibly. Anybody with saved compiled patterns that use
1828     \p or \P will have to recompile them.
1829    
1830     22. Added "Any" and "L&" to the supported property types.
1831    
1832     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1833     but give a compile time error if the value is greater than 0xff.
1834    
1835     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1836     accidentally not being installed or uninstalled.
1837    
1838     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1839     made were to insert the current release number. This seemed silly, because
1840     it made things harder for people building PCRE on systems that don't run
1841     "configure". I have turned pcre.h into a distributed file, no longer built
1842     by "configure", with the version identification directly included. There is
1843     no longer a pcre.h.in file.
1844    
1845     However, this change necessitated a change to the pcre-config script as
1846     well. It is built from pcre-config.in, and one of the substitutions was the
1847     release number. I have updated configure.ac so that ./configure now finds
1848     the release number by grepping pcre.h.
1849    
1850     26. Added the ability to run the tests under valgrind.
1851    
1852    
1853 nigel 85 Version 6.4 05-Sep-05
1854     ---------------------
1855    
1856     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1857     "--" to be printed when multiple files were scanned, even when none of the
1858     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1859     consider it to be a bug, and have restored the previous behaviour.
1860    
1861     2. A couple of code tidies to get rid of compiler warnings.
1862    
1863     3. The pcretest program used to cheat by referring to symbols in the library
1864     whose names begin with _pcre_. These are internal symbols that are not
1865     really supposed to be visible externally, and in some environments it is
1866     possible to suppress them. The cheating is now confined to including
1867     certain files from the library's source, which is a bit cleaner.
1868    
1869     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1870     file's purpose clearer.
1871    
1872     5. Reorganized pcre_ucp_findchar().
1873    
1874    
1875 nigel 83 Version 6.3 15-Aug-05
1876     ---------------------
1877    
1878     1. The file libpcre.pc.in did not have general read permission in the tarball.
1879    
1880     2. There were some problems when building without C++ support:
1881    
1882     (a) If C++ support was not built, "make install" and "make test" still
1883     tried to test it.
1884    
1885     (b) There were problems when the value of CXX was explicitly set. Some
1886     changes have been made to try to fix these, and ...
1887    
1888     (c) --disable-cpp can now be used to explicitly disable C++ support.
1889    
1890     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1891     backslash in a target when C++ was disabled. This confuses some
1892     versions of "make", apparently. Using an intermediate variable solves
1893     this. (Same for CPP_LOBJ.)
1894    
1895     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1896     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1897     necessary on certain architectures.
1898    
1899     4. Added a setting of -export-symbols-regex to the link command to remove
1900     those symbols that are exported in the C sense, but actually are local
1901     within the library, and not documented. Their names all begin with
1902     "_pcre_". This is not a perfect job, because (a) we have to except some
1903     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1904     available (and never for static libraries). I have made a note to try to
1905     find a way round (a) in the future.
1906    
1907    
1908 nigel 81 Version 6.2 01-Aug-05
1909     ---------------------
1910    
1911     1. There was no test for integer overflow of quantifier values. A construction
1912     such as {1111111111111111} would give undefined results. What is worse, if
1913     a minimum quantifier for a parenthesized subpattern overflowed and became
1914     negative, the calculation of the memory size went wrong. This could have
1915     led to memory overwriting.
1916    
1917     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1918    
1919     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1920     operating environments where this matters.
1921    
1922     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1923     PCRE options from within the C++ wrapper.
1924    
1925     5. Named capturing subpatterns were not being correctly counted when a pattern
1926     was compiled. This caused two problems: (a) If there were more than 100
1927     such subpatterns, the calculation of the memory needed for the whole
1928     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1929     back references of the form \12, where the number was greater than 9, were
1930     not recognized as back references, even though there were sufficient
1931     previous subpatterns.
1932    
1933     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1934     versions of gcc, e.g. 2.95.4.
1935    
1936    
1937 nigel 79 Version 6.1 21-Jun-05
1938     ---------------------
1939    
1940     1. There was one reference to the variable "posix" in pcretest.c that was not
1941     surrounded by "#if !defined NOPOSIX".
1942    
1943     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1944     the cross-check on the old pcre_info() function, for the benefit of the
1945     cut-down version of PCRE that is currently imported into Exim.
1946    
1947     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1948     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1949     patterns that start (?i) but I don't think that matters. The use of (?i) is
1950     just an example; this all applies to the other options as well.
1951    
1952     4. Since libtool seems to echo the compile commands it is issuing, the output
1953     from "make" can be reduced a bit by putting "@" in front of each libtool
1954     compile command.
1955    
1956     5. Patch from the folks at Google for configure.in to be a bit more thorough
1957     in checking for a suitable C++ installation before trying to compile the
1958     C++ stuff. This should fix a reported problem when a compiler was present,
1959     but no suitable headers.
1960    
1961     6. The man pages all had just "PCRE" as their title. I have changed them to
1962     be the relevant file name. I have also arranged that these names are
1963     retained in the file doc/pcre.txt, which is a concatenation in text format
1964     of all the man pages except the little individual ones for each function.
1965    
1966     7. The NON-UNIX-USE file had not been updated for the different set of source
1967     files that come with release 6. I also added a few comments about the C++
1968     wrapper.
1969    
1970    
1971 nigel 77 Version 6.0 07-Jun-05
1972     ---------------------
1973    
1974     1. Some minor internal re-organization to help with my DFA experiments.
1975    
1976     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1977     didn't matter for the library itself when fully configured, but did matter
1978     when compiling without UCP support, or within Exim, where the ucp files are
1979     not imported.
1980    
1981     3. Refactoring of the library code to split up the various functions into
1982     different source modules. The addition of the new DFA matching code (see
1983     below) to a single monolithic source would have made it really too
1984     unwieldy, quite apart from causing all the code to be include in a
1985     statically linked application, when only some functions are used. This is
1986     relevant even without the DFA addition now that patterns can be compiled in
1987     one application and matched in another.
1988    
1989     The downside of splitting up is that there have to be some external
1990     functions and data tables that are used internally in different modules of
1991     the library but which are not part of the API. These have all had their
1992     names changed to start with "_pcre_" so that they are unlikely to clash
1993     with other external names.
1994    
1995     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1996     a different (DFA) algorithm. Although it is slower than the original
1997     function, it does have some advantages for certain types of matching
1998     problem.
1999    
2000     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2001     including restarting after a partial match.
2002    
2003     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2004     defined when compiling for Windows was sent to me. I have put it into the
2005     code, though I have no means of testing or verifying it.
2006    
2007     7. Added the pcre_refcount() auxiliary function.
2008    
2009     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2010     match before or at the first newline in the subject string. In pcretest,
2011     the /f option on a pattern can be used to set this.
2012    
2013     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2014     would behave wrongly. This has been present in PCRE since release 4.0.
2015    
2016     10. A number of changes to the pcregrep command:
2017    
2018     (a) Refactored how -x works; insert ^(...)$ instead of setting
2019     PCRE_ANCHORED and checking the length, in preparation for adding
2020     something similar for -w.
2021    
2022     (b) Added the -w (match as a word) option.
2023    
2024     (c) Refactored the way lines are read and buffered so as to have more
2025     than one at a time available.
2026    
2027     (d) Implemented a pcregrep test script.
2028    
2029     (e) Added the -M (multiline match) option. This allows patterns to match
2030     over several lines of the subject. The buffering ensures that at least
2031     8K, or the rest of the document (whichever is the shorter) is available
2032     for matching (and similarly the previous 8K for lookbehind assertions).
2033    
2034     (f) Changed the --help output so that it now says
2035    
2036     -w, --word-regex(p)
2037    
2038     instead of two lines, one with "regex" and the other with "regexp"
2039     because that confused at least one person since the short forms are the
2040     same. (This required a bit of code, as the output is generated
2041     automatically from a table. It wasn't just a text change.)
2042    
2043     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2044     option but starts with a hyphen. Could be a pattern or a path name
2045     starting with a hyphen, for instance.
2046    
2047     (h) "-" can be given as a file name to represent stdin.
2048    
2049     (i) When file names are being printed, "(standard input)" is used for
2050     the standard input, for compatibility with GNU grep. Previously
2051     "<stdin>" was used.
2052    
2053     (j) The option --label=xxx can be used to supply a name to be used for
2054     stdin when file names are being printed. There is no short form.
2055    
2056     (k) Re-factored the options decoding logic because we are going to add
2057     two more options that take data. Such options can now be given in four
2058     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2059    
2060     (l) Added the -A, -B, and -C options for requesting that lines of context
2061     around matches be printed.
2062    
2063     (m) Added the -L option to print the names of files that do not contain
2064     any matching lines, that is, the complement of -l.
2065    
2066     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2067     continue to scan other files.
2068    
2069     (o) The -s option was incorrectly implemented. For compatibility with other
2070     greps, it now suppresses the error message for a non-existent or non-
2071     accessible file (but not the return code). There is a new option called
2072     -q that suppresses the output of matching lines, which was what -s was
2073     previously doing.
2074    
2075     (p) Added --include and --exclude options to specify files for inclusion
2076     and exclusion when recursing.
2077    
2078     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2079     Hopefully, it now does.
2080    
2081     12. Missing cast in pcre_study().
2082    
2083     13. Added an "uninstall" target to the makefile.
2084    
2085     14. Replaced "extern" in the function prototypes in Makefile.in with
2086     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2087     world, but is set differently for Windows.
2088    
2089     15. Added a second compiling function called pcre_compile2(). The only
2090     difference is that it has an extra argument, which is a pointer to an
2091     integer error code. When there is a compile-time failure, this is set
2092     non-zero, in addition to the error test pointer being set to point to an
2093     error message. The new argument may be NULL if no error number is required
2094     (but then you may as well call pcre_compile(), which is now just a
2095     wrapper). This facility is provided because some applications need a
2096     numeric error indication, but it has also enabled me to tidy up the way
2097     compile-time errors are handled in the POSIX wrapper.
2098    
2099     16. Added VPATH=.libs to the makefile; this should help when building with one
2100     prefix path and installing with another. (Or so I'm told by someone who
2101     knows more about this stuff than I do.)
2102    
2103     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2104     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2105     match everything, including newlines. This is not POSIX-compatible, but
2106     somebody wanted the feature. From pcretest it can be activated by using
2107     both the P and the s flags.
2108    
2109     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2110    
2111     19. libpcre.pc was being incorrectly installed as executable.
2112    
2113     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2114     it now also looks for '\r' so that it will work unmodified on Windows.
2115    
2116     21. Added Google's contributed C++ wrapper to the distribution.
2117    
2118     22. Added some untidy missing memory free() calls in pcretest, to keep
2119     Electric Fence happy when testing.
2120    
2121    
2122    
2123 nigel 75 Version 5.0 13-Sep-04
2124     ---------------------
2125    
2126     1. Internal change: literal characters are no longer packed up into items
2127     containing multiple characters in a single byte-string. Each character
2128     is now matched using a separate opcode. However, there may be more than one
2129     byte in the character in UTF-8 mode.
2130    
2131     2. The pcre_callout_block structure has two new fields: pattern_position and
2132     next_item_length. These contain the offset in the pattern to the next match
2133     item, and its length, respectively.
2134    
2135     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2136     insertion of callouts before each pattern item. Added the /C option to
2137     pcretest to make use of this.
2138    
2139     4. On the advice of a Windows user, the lines
2140    
2141     #if defined(_WIN32) || defined(WIN32)
2142     _setmode( _fileno( stdout ), 0x8000 );
2143     #endif /* defined(_WIN32) || defined(WIN32) */
2144    
2145     have been added to the source of pcretest. This apparently does useful
2146     magic in relation to line terminators.
2147    
2148     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2149     for the benefit of those environments where the "b" makes a difference.
2150    
2151     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2152     to know about it. I have put a hack into configure.in that adds in code
2153     to set GCC=yes if CC=icc. This seems to end up at a point in the
2154     generated configure script that is early enough to affect the setting of
2155     compiler options, which is what is needed, but I have no means of testing
2156     whether it really works. (The user who reported this had patched the
2157     generated configure script, which of course I cannot do.)
2158    
2159     LATER: After change 22 below (new libtool files), the configure script
2160     seems to know about icc (and also ecc). Therefore, I have commented out
2161     this hack in configure.in.
2162    
2163     7. Added support for pkg-config (2 patches were sent in).
2164    
2165     8. Negated POSIX character classes that used a combination of internal tables
2166     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2167     [[:^ascii]]. Typically, they would match almost any characters. The other
2168     POSIX classes were not broken in this way.
2169    
2170     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2171     to find the match, as PCRE was deluded into thinking that the match had to
2172     start at the start point or following a newline. The same bug applied to
2173     patterns with negative forward assertions or any backward assertions
2174     preceding ".*" at the start, unless the pattern required a fixed first
2175     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2176    
2177     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2178     starting at the last subject character, bytes beyond the end of the subject
2179     string were read.
2180    
2181     11. Renamed the variable "class" as "classbits" to make life easier for C++
2182     users. (Previously there was a macro definition, but it apparently wasn't
2183     enough.)
2184    
2185     12. Added the new field "tables" to the extra data so that tables can be passed
2186     in at exec time, or the internal tables can be re-selected. This allows
2187     a compiled regex to be saved and re-used at a later time by a different
2188     program that might have everything at different addresses.
2189    
2190     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2191     -R library as well as a -L library.
2192    
2193     14. The debugging options of pcretest (-d on the command line or D on a
2194     pattern) showed incorrect output for anything following an extended class
2195     that contained multibyte characters and which was followed by a quantifier.
2196    
2197     15. Added optional support for general category Unicode character properties
2198     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2199     support. It adds about 90K to the size of the library. The meanings of the
2200     inbuilt class escapes such as \d and \s have NOT been changed.
2201    
2202     16. Updated pcredemo.c to include calls to free() to release the memory for the
2203     compiled pattern.
2204    
2205     17. The generated file chartables.c was being created in the source directory
2206     instead of in the building directory. This caused the build to fail if the
2207     source directory was different from the building directory, and was
2208     read-only.
2209    
2210     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2211     file. No doubt somebody will tell me if they don't make sense... Also added
2212     Dan Mooney's comments about building on OpenVMS.
2213    
2214     19. Added support for partial matching via the PCRE_PARTIAL option for
2215     pcre_exec() and the \P data escape in pcretest.
2216    
2217     20. Extended pcretest with 3 new pattern features:
2218    
2219     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2220     write the compiled pattern to the file whose name is "rest-of-line".
2221     This is a straight binary dump of the data, with the saved pointer to
2222     the character tables forced to be NULL. The study data, if any, is
2223     written too. After writing, pcretest reads a new pattern.
2224    
2225     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2226     compiled pattern from the given file. There must not be any
2227     occurrences of "<" in the file name (pretty unlikely); if there are,
2228     pcretest will instead treat the initial "<" as a pattern delimiter.
2229     After reading in the pattern, pcretest goes on to read data lines as
2230     usual.
2231    
2232     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2233     and 16-bit fields in a compiled pattern, to simulate a pattern that
2234     was compiled on a host of opposite endianness.
2235    
2236     21. The pcre-exec() function can now cope with patterns that were compiled on
2237     hosts of opposite endianness, with this restriction:
2238    
2239     As for any compiled expression that is saved and used later, the tables
2240     pointer field cannot be preserved; the extra_data field in the arguments
2241     to pcre_exec() should be used to pass in a tables address if a value
2242     other than the default internal tables were used at compile time.
2243    
2244     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2245     now diagnosed as an error. Previously, most of the time, a negative number
2246     would have been treated as zero, but if in addition "ovector" was passed as
2247     NULL, a crash could occur.
2248    
2249     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2250     new versions from the libtool 1.5 distribution (the last one is a copy of
2251     a file called libtool.m4). This seems to have fixed the need to patch
2252     "configure" to support Darwin 1.3 (which I used to do). However, I still
2253     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2254     workstation).
2255    
2256     24. Changed the PCRE licence to be the more standard "BSD" licence.
2257    
2258    
2259 nigel 73 Version 4.5 01-Dec-03
2260     ---------------------
2261    
2262     1. There has been some re-arrangement of the code for the match() function so
2263     that it can be compiled in a version that does not call itself recursively.
2264     Instead, it keeps those local variables that need separate instances for
2265     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2266     needs to "recurse". Keeping track of where control must go is done by means
2267     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2268     hide most of the details from the main code, and operates only if
2269     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2270     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2271     operating.
2272    
2273     To make it easier for callers to provide specially tailored get/free
2274     functions for this usage, two new functions, pcre_stack_malloc, and
2275     pcre_stack_free, are used. They are always called in strict stacking order,
2276     and the size of block requested is always the same.
2277    
2278     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2279     PCRE has been compiled to use the stack or the heap for recursion. The
2280     -C option of pcretest uses this to show which version is compiled.
2281    
2282     A new data escape \S, is added to pcretest; it causes the amounts of store
2283     obtained and freed by both kinds of malloc/free at match time to be added
2284     to the output.
2285    
2286     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2287     what's available on my current Linux desktop machine.
2288    
2289     3. When matching a UTF-8 string, the test for a valid string at the start has
2290     been extended. If start_offset is not zero, PCRE now checks that it points
2291     to a byte that is the start of a UTF-8 character. If not, it returns
2292     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2293     this is necessary because there may be backward assertions in the pattern.
2294     When matching the same subject several times, it may save resources to use
2295     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2296    
2297     4. The code for checking the validity of UTF-8 strings has been tightened so
2298     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2299     containing "overlong sequences".
2300    
2301     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2302     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2303     should have been "&", but it just so happened that all the cases this let
2304     through by mistake were picked up later in the function.
2305    
2306     6. I had used a variable called "isblank" - this is a C99 function, causing
2307     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2308    
2309     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2310     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2311     so the version is shown; (c) stop "make test" echoing "./RunTest".
2312    
2313     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2314    
2315     9. The prototype for memmove() for systems that don't have it was using
2316     size_t, but the inclusion of the header that defines size_t was later. I've
2317     moved the #includes for the C headers earlier to avoid this.
2318    
2319     10. Added some adjustments to the code to make it easier to compiler on certain
2320     special systems:
2321    
2322     (a) Some "const" qualifiers were missing.
2323     (b) Added the macro EXPORT before all exported functions; by default this
2324     is defined to be empty.
2325     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2326     that it reads its output file name as an argument instead of writing
2327     to the standard output and assuming this can be redirected.
2328    
2329     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2330     class containing characters with values greater than 255, PCRE compilation
2331     went into a loop.
2332    
2333     12. A recursive reference to a subpattern that was within another subpattern
2334     that had a minimum quantifier of zero caused PCRE to crash. For example,
2335     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2336     recursion. If the recursively-called subpattern itself had a zero repeat,
2337     that was OK.
2338    
2339     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2340     buffer into which it was copied (for escape processing) was still set at
2341     1024, so long lines caused crashes.
2342    
2343     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2344     "internal error: code overflow...". This applied to any character class
2345     that was followed by a possessive quantifier.
2346    
2347     15. Modified the Makefile to add libpcre.la as a prerequisite for
2348     libpcreposix.la because I was told this is needed for a parallel build to
2349     work.
2350    
2351     16. If a pattern that contained .* following optional items at the start was
2352     studied, the wrong optimizing data was generated, leading to matching
2353     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2354     matching string must start with a or b or c. The correct conclusion for
2355     this pattern is that a match can start with any character.
2356    
2357    
2358 nigel 71 Version 4.4 13-Aug-03
2359     ---------------------
2360    
2361     1. In UTF-8 mode, a character class containing characters with values between
2362     127 and 255 was not handled correctly if the compiled pattern was studied.
2363     In fixing this, I have also improved the studying algorithm for such
2364     classes (slightly).
2365    
2366     2. Three internal functions had redundant arguments passed to them. Removal
2367     might give a very teeny performance improvement.
2368    
2369     3. Documentation bug: the value of the capture_top field in a callout is *one
2370     more than* the number of the hightest numbered captured substring.
2371    
2372     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2373     in incorrectly linking with a previously installed version. They now link
2374     explicitly with libpcre.la.
2375    
2376     5. configure.in no longer needs to recognize Cygwin specially.
2377    
2378     6. A problem in pcre.in for Windows platforms is fixed.
2379    
2380     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2381     pcretest, it used to include the size of the study block as part of its
2382     output. Unfortunately, the structure contains a field that has a different
2383     size on different hardware architectures. This meant that the tests that
2384     showed this size failed. As the block is currently always of a fixed size,
2385     this information isn't actually particularly useful in pcretest output, so
2386     I have just removed it.
2387    
2388     8. Three pre-processor statements accidentally did not start in column 1.
2389     Sadly, there are *still* compilers around that complain, even though
2390     standard C has not required this for well over a decade. Sigh.
2391    
2392     9. In pcretest, the code for checking callouts passed small integers in the
2393     callout_data field, which is a void * field. However, some picky compilers
2394     complained about the casts involved for this on 64-bit systems. Now
2395     pcretest passes the address of the small integer instead, which should get
2396     rid of the warnings.
2397    
2398     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2399     both compile and run time, and gives an error if an invalid UTF-8 sequence
2400     is found. There is a option for disabling this check in cases where the
2401     string is known to be correct and/or the maximum performance is wanted.
2402    
2403     11. In response to a bug report, I changed one line in Makefile.in from
2404    
2405     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2406     to
2407     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2408    
2409     to look similar to other lines, but I have no way of telling whether this
2410     is the right thing to do, as I do not use Windows. No doubt I'll get told
2411     if it's wrong...
2412    
2413    
2414 nigel 69 Version 4.3 21-May-03
2415     ---------------------
2416    
2417     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2418     Makefile.
2419    
2420     2. Some refactoring to improve the quality of the code:
2421    
2422     (i) The utf8_table... variables are now declared "const".
2423    
2424     (ii) The code for \cx, which used the "case flipping" table to upper case
2425     lower case letters, now just substracts 32. This is ASCII-specific,
2426     but the whole concept of \cx is ASCII-specific, so it seems
2427     reasonable.
2428    
2429     (iii) PCRE was using its character types table to recognize decimal and
2430     hexadecimal digits in the pattern. This is silly, because it handles
2431     only 0-9, a-f, and A-F, but the character types table is locale-
2432     specific, which means strange things might happen. A private
2433     table is now used for this - though it costs 256 bytes, a table is
2434     much faster than multiple explicit tests. Of course, the standard
2435     character types table is still used for matching digits in subject
2436     strings against \d.
2437    
2438     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2439     ending in _t are). So I've renamed it as ESC_tee.
2440    
2441     3. The first argument for regexec() in the POSIX wrapper should have been
2442     defined as "const".
2443    
2444     4. Changed pcretest to use malloc() for its buffers so that they can be
2445     Electric Fenced for debugging.
2446    
2447     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2448     to read one or more bytes before the start of the subject string. Often this
2449     had no effect on PCRE's behaviour, but in some circumstances it could
2450     provoke a segmentation fault.
2451    
2452     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2453     to try to read one or more bytes before the start of the subject string.
2454    
2455     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2456     UTF-8 support could misbehave in various ways if the subject string
2457     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2458     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2459     back over UTF-8 characters.)
2460    
2461    
2462 nigel 67 Version 4.2 14-Apr-03
2463     ---------------------
2464    
2465     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2466    
2467     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2468     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2469     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2470     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2471     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2472     and BUILD_EXEEXT
2473     Note: automatic setting of the BUILD variables is not yet working
2474     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2475     compile-time but not at link-time
2476     [LINK]: use for linking executables only
2477     make different versions for Windows and non-Windows
2478     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2479     libraries
2480     [LINK_FOR_BUILD]: new variable
2481     [OBJEXT]: use throughout
2482     [EXEEXT]: use throughout
2483     <winshared>: new target
2484     <wininstall>: new target
2485     <dftables.o>: use native compiler
2486     <dftables>: use native linker
2487     <install>: handle Windows platform correctly
2488     <clean>: ditto
2489     <check>: ditto
2490     copy DLL to top builddir before testing
2491    
2492     As part of these changes, -no-undefined was removed again. This was reported
2493     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2494     in any case.
2495    
2496     3. Some tidies to get rid of compiler warnings:
2497    
2498     . In the match_data structure, match_limit was an unsigned long int, whereas
2499     match_call_count was an int. I've made them both unsigned long ints.
2500    
2501     . In pcretest the fact that a const uschar * doesn't automatically cast to
2502     a void * provoked a warning.
2503    
2504     . Turning on some more compiler warnings threw up some "shadow" variables
2505     and a few more missing casts.
2506    
2507     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2508     option, a class that contained a single character with a value between 128
2509     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2510    
2511     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2512     option, a class that contained several characters, but with at least one
2513     whose value was between 128 and 255 caused PCRE to crash.
2514    
2515    
2516 nigel 65 Version 4.1 12-Mar-03
2517     ---------------------
2518 nigel 63
2519 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2520     needed, and a string in dftables.c that was longer than standard compilers are
2521     required to support.
2522    
2523     2. Compiling with Sun's compiler found a few more places where the code could
2524     be tidied up in order to avoid warnings.
2525    
2526     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2527     first of these names is deprecated in the latest Autoconf in favour of the name
2528     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2529     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2530     analogy I have changed it to CFLAGS_FOR_BUILD.
2531    
2532     4. Added -no-undefined to the linking command in the Makefile, because this is
2533     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2534     linking step for the pcreposix library.
2535    
2536     5. PCRE was failing to diagnose the case of two named groups with the same
2537     name.
2538    
2539     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2540     literal character that is needed in the subject for a match, and scans along to
2541     ensure that it is present before embarking on the full matching process. This
2542     saves time in cases of nested unlimited repeats that are never going to match.
2543     Problem: the scan can take a lot of time if the subject is very long (e.g.
2544     megabytes), thus penalizing straightforward matches. It is now done only if the
2545     amount of subject to be scanned is less than 1000 bytes.
2546    
2547     7. A lesser problem with the same optimization is that it was recording the
2548     first character of an anchored pattern as "needed", thus provoking a search
2549     right along the subject, even when the first match of the pattern was going to
2550     fail. The "needed" character is now not set for anchored patterns, unless it
2551     follows something in the pattern that is of non-fixed length. Thus, it still
2552     fulfils its original purpose of finding quick non-matches in cases of nested
2553     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2554    
2555    
2556     Version 4.0 17-Feb-03
2557     ---------------------
2558    
2559 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2560     extended to the end of string, PCRE compiled incorrect data. This could lead to
2561     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2562    
2563     2. Moved to autoconf 2.53 and libtool 1.4.2.
2564    
2565     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2566     the special perltest8 script is no longer needed - all the tests can be run
2567     from a single perltest script.
2568    
2569     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2570     by \s. It has now been removed in PCRE. This means it isn't recognized as
2571     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2572     class [:space:] *does* include VT, thereby creating a mess.
2573    
2574     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2575     space and tab.
2576    
2577     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2578     its new features into the main test script, reducing the number of scripts.
2579    
2580     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2581     were backward compatible, and made the (?i) apply to the whole pattern, as if
2582     /i were given. Now it behaves more logically, and applies the option setting
2583     only to what follows. PCRE has been changed to follow suit. However, if it
2584     finds options settings right at the start of the pattern, it extracts them into
2585     the global options, as before. Thus, they show up in the info data.
2586    
2587     8. Added support for the \Q...\E escape sequence. Characters in between are
2588     treated as literals. This is slightly different from Perl in that $ and @ are
2589     also handled as literals inside the quotes. In Perl, they will cause variable
2590     interpolation. Note the following examples:
2591    
2592     Pattern PCRE matches Perl matches
2593    
2594     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2595     \Qabc\$xyz\E abc\$xyz abc\$xyz
2596     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2597    
2598     For compatibility with Perl, \Q...\E sequences are recognized inside character
2599     classes as well as outside them.
2600    
2601     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2602     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2603     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2604     signed/unsigned warnings.
2605    
2606     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2607     option for pcretest, so I've replaced it by a simple function that does just
2608     that job.
2609    
2610     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2611     "pcregrep -".
2612    
2613     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2614     Java package. This provides some syntactic sugar for simple cases of what my
2615     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2616     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2617     item, you can use this simplified notation. Note that only makes sense with
2618     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2619     greediness, whatever the setting of the PCRE_UNGREEDY option.
2620    
2621     13. A change of greediness default within a pattern was not taking effect at
2622     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2623     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2624     was abstracted outside.
2625    
2626     14. PCRE now supports the \G assertion. It is true when the current matching
2627     position is at the start point of the match. This differs from \A when the
2628     starting offset is non-zero. Used with the /g option of pcretest (or similar
2629     code), it works in the same way as it does for Perl's /g option. If all
2630     alternatives of a regex begin with \G, the expression is anchored to the start
2631     match position, and the "anchored" flag is set in the compiled expression.
2632    
2633     15. Some bugs concerning the handling of certain option changes within patterns
2634     have been fixed. These applied to options other than (?ims). For example,
2635     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2636     been the other way round. Some of this was related to change 7 above.
2637    
2638     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2639     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2640     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2641     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2642    
2643     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2644     mode. Unlike ".", it always matches newline, whatever the setting of
2645     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2646     assertions. Perl allows it, but it doesn't (in general) work because it can't
2647     calculate the length of the lookbehind. At least, that's the case for Perl
2648     5.8.0 - I've been told they are going to document that it doesn't work in
2649     future.
2650    
2651     18. Added an error diagnosis for escapes that PCRE does not support: these are
2652     \L, \l, \N, \P, \p, \U, \u, and \X.
2653    
2654     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2655     reading past the end of the pattern in cases such as /[abcd/.
2656    
2657     20. PCRE was getting more memory than necessary for patterns with classes that
2658     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2659    
2660     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2661     compiling PCRE for use with Virtual Pascal.
2662    
2663     22. Small fix to the Makefile to make it work properly if the build is done
2664     outside the source tree.
2665    
2666     23. Added a new extension: a condition to go with recursion. If a conditional
2667     subpattern starts with (?(R) the "true" branch is used if recursion has
2668     happened, whereas the "false" branch is used only at the top level.
2669    
2670     24. When there was a very long string of literal characters (over 255 bytes
2671     without UTF support, over 250 bytes with UTF support), the computation of how
2672     much memory was required could be incorrect, leading to segfaults or other
2673     strange effects.
2674    
2675     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2676     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2677     there was a subsequent back reference to those brackets. This meant that, for
2678     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2679     possible to check for precisely this case. All we can do is abandon the
2680     optimization if .* occurs inside capturing brackets when there are any back
2681     references whatsoever. (See below for a better fix that came later.)
2682    
2683     26. The handling of the optimization for finding the first character of a
2684     non-anchored pattern, and for finding a character that is required later in the
2685     match were failing in some cases. This didn't break the matching; it just
2686     failed to optimize when it could. The way this is done has been re-implemented.
2687    
2688     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2689    
2690     28. Added a new feature that provides some of the functionality that Perl
2691     provides with (?{...}). The facility is termed a "callout". The way it is done
2692     in PCRE is for the caller to provide an optional function, by setting
2693     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2694     global variable. By default it is unset, which disables all calling out. To get
2695     the function called, the regex must include (?C) at appropriate points. This
2696     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2697     This provides a means of identifying different callout points. When PCRE
2698     reaches such a point in the regex, if pcre_callout has been set, the external
2699     function is called. It is provided with data in a structure called
2700     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2701     matching continues; if it returns a non-zero value, the match at the current
2702     point fails. However, backtracking will occur if possible. [This was changed
2703     later and other features added - see item 49 below.]
2704    
2705     29. pcretest is upgraded to test the callout functionality. It provides a
2706     callout function that displays information. By default, it shows the start of
2707     the match and the current position in the text. There are some new data escapes
2708     to vary what happens:
2709    
2710     \C+ in addition, show current contents of captured substrings
2711     \C- do not supply a callout function
2712     \C!n return 1 when callout number n is reached
2713     \C!n!m return 1 when callout number n is reached for the mth time
2714    
2715     30. If pcregrep was called with the -l option and just a single file name, it
2716     output "<stdin>" if a match was found, instead of the file name.
2717    
2718     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2719     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2720     pcre_exec(). This saves a malloc/free per call. The default value of
2721     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2722     when configuring.
2723    
2724     32. The default maximum size of a compiled pattern is 64K. There have been a
2725     few cases of people hitting this limit. The code now uses macros to handle the
2726     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2727     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2728     configuring. Tests 2 and 5 work only with 2-byte links because they output
2729     debugging information about compiled patterns.
2730    
2731     33. Internal code re-arrangements:
2732    
2733     (a) Moved the debugging function for printing out a compiled regex into
2734     its own source file (printint.c) and used #include to pull it into
2735     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2736     separate copies.
2737    
2738     (b) Defined the list of op-code names for debugging as a macro in
2739     internal.h so that it is next to the definition of the opcodes.
2740    
2741     (c) Defined a table of op-code lengths for simpler skipping along compiled
2742     code. This is again a macro in internal.h so that it is next to the
2743     definition of the opcodes.
2744    
2745     34. Added support for recursive calls to individual subpatterns, along the
2746     lines of Robin Houston's patch (but implemented somewhat differently).
2747    
2748     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2749     allow it to read and process whole directories in Win32. This code was
2750     contributed by Lionel Fourquaux; it has not been tested by me.
2751    
2752     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2753     used to name a group. Names consist of alphanumerics and underscores, and must
2754     be unique. Back references use the syntax (?P=name) and recursive calls use
2755     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2756     numbers. The function pcre_fullinfo() can be used after compilation to extract
2757     a name/number map. There are three relevant calls:
2758    
2759     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2760     PCRE_INFO_NAMECOUNT yields the number of entries
2761     PCRE_INFO_NAMETABLE yields a pointer to the map.
2762    
2763     The map is a vector of fixed-size entries. The size of each entry depends on
2764     the length of the longest name used. The first two bytes of each entry are the
2765     group number, most significant byte first. There follows the corresponding
2766     name, zero terminated. The names are in alphabetical order.
2767    
2768     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2769     case instead of 255. Making it the same both with and without UTF-8 support
2770     means that the same test output works with both.
2771    
2772     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2773     calling malloc() with a zero argument.
2774    
2775     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2776     optimization. I've improved things by keeping a bitmap of backreferences with
2777     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2778     fact referenced, the optimization can be applied. It is unlikely that a
2779     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2780     the match to follow \n) will appear inside brackets with a number greater than
2781     31, but if it does, any back reference > 31 suppresses the optimization.
2782    
2783     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2784     of disabling numbered capturing parentheses. Any opening parenthesis that is
2785     not followed by ? behaves as if it were followed by ?: but named parentheses
2786     can still be used for capturing (and they will acquire numbers in the usual
2787     way).
2788    
2789     41. Redesigned the return codes from the match() function into yes/no/error so
2790     that errors can be passed back from deep inside the nested calls. A malloc
2791     failure while inside a recursive subpattern call now causes the
2792     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2793    
2794     42. It is now possible to set a limit on the number of times the match()
2795     function is called in a call to pcre_exec(). This facility makes it possible to
2796     limit the amount of recursion and backtracking, though not in a directly
2797     obvious way, because the match() function is used in a number of different
2798     circumstances. The count starts from zero for each position in the subject
2799     string (for non-anchored patterns). The default limit is, for compatibility, a
2800     large number, namely 10 000 000. You can change this in two ways:
2801    
2802     (a) When configuring PCRE before making, you can use --with-match-limit=n
2803     to set a default value for the compiled library.
2804    
2805     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2806     a different value is set. See 45 below.
2807    
2808     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2809    
2810     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2811     of things that can be changed at compile time. The first argument specifies
2812     what is wanted and the second points to where the information is to be placed.
2813     The current list of available information is:
2814    
2815     PCRE_CONFIG_UTF8
2816    
2817     The output is an integer that is set to one if UTF-8 support is available;
2818     otherwise it is set to zero.
2819    
2820     PCRE_CONFIG_NEWLINE
2821    
2822     The output is an integer that it set to the value of the code that is used for
2823     newline. It is either LF (10) or CR (13).
2824    
2825     PCRE_CONFIG_LINK_SIZE
2826    
2827     The output is an integer that contains the number of bytes used for internal
2828     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2829    
2830     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2831    
2832     The output is an integer that contains the threshold above which the POSIX
2833     interface uses malloc() for output vectors. See item 31 above.
2834    
2835     PCRE_CONFIG_MATCH_LIMIT
2836    
2837     The output is an unsigned integer that contains the default limit of the number
2838     of match() calls in a pcre_exec() execution. See 42 above.
2839    
2840     44. pcretest has been upgraded by the addition of the -C option. This causes it
2841     to extract all the available output from the new pcre_config() function, and to
2842     output it. The program then exits immediately.
2843    
2844     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2845     order to support additional features. One way would have been to define
2846     pcre_exec2() (for example) with extra arguments, but this would not have been
2847     extensible, and would also have required all calls to the original function to
2848     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2849     is used for passing in "extra" data from pcre_study().
2850    
2851     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2852     contains the following fields:
2853    
2854     flags a bitmap indicating which of the following fields are set
2855     study_data opaque data from pcre_study()
2856     match_limit a way of specifying a limit on match() calls for a specific
2857     call to pcre_exec()
2858     callout_data data for callouts (see 49 below)
2859    
2860     The flag bits are also defined in pcre.h, and are
2861    
2862     PCRE_EXTRA_STUDY_DATA
2863     PCRE_EXTRA_MATCH_LIMIT
2864     PCRE_EXTRA_CALLOUT_DATA
2865    
2866     The pcre_study() function now returns one of these new pcre_extra blocks, with
2867     the actual study data pointed to by the study_data field, and the
2868     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2869     before. That is, this change is entirely upwards-compatible and requires no
2870     change to existing code.
2871    
2872     If you want to pass in additional data to pcre_exec(), you can either place it
2873     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2874     block.
2875    
2876     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2877     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2878     times with different match limits, until it finds the minimum value needed for
2879     pcre_exec() to complete. The value is then output. This can be instructive; for
2880     most simple matches the number is quite small, but for pathological cases it
2881     gets very large very quickly.
2882    
2883     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2884     returns the size of the data block pointed to by the study_data field in a
2885     pcre_extra block, that is, the value that was passed as the argument to
2886     pcre_malloc() when PCRE was getting memory in which to place the information
2887     created by pcre_study(). The fourth argument should point to a size_t variable.
2888     pcretest has been extended so that this information is shown after a successful
2889     pcre_study() call when information about the compiled regex is being displayed.
2890    
2891     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2892     because what follows is always an absolute path. (Later: it turns out that this
2893     is more than cosmetic for MinGW, because it doesn't like empty path
2894     components.)
2895    
2896     49. Some changes have been made to the callout feature (see 28 above):
2897    
2898     (i) A callout function now has three choices for what it returns:
2899    
2900     0 => success, carry on matching
2901     > 0 => failure at this point, but backtrack if possible
2902     < 0 => serious error, return this value from pcre_exec()
2903    
2904     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2905     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2906     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2907     use by callout functions. It will never be used by PCRE itself.
2908    
2909     (ii) The pcre_extra structure (see 45 above) has a void * field called
2910     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2911     pcre_callout_block structure has a field of the same name. The contents of
2912     the field passed in the pcre_extra structure are passed to the callout
2913     function in the corresponding field in the callout block. This makes it
2914     easier to use the same callout-containing regex from multiple threads. For
2915     testing, the pcretest program has a new data escape
2916    
2917     \C*n pass the number n (may be negative) as callout_data
2918    
2919     If the callout function in pcretest receives a non-zero value as
2920     callout_data, it returns that value.
2921    
2922     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2923     there were some redundant $(CFLAGS) in commands that are now specified as
2924     $(LINK), which already includes $(CFLAGS).
2925    
2926     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2927     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2928     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2929     one-byte characters throughout. Note that case-insensitive matching applies
2930     only to characters whose values are less than 256. PCRE doesn't support the
2931     notion of cases for higher-valued characters.
2932    
2933     (i) A character class whose characters are all within 0-255 is handled as
2934     a bit map, and the map is inverted for negative classes. Previously, a
2935     character > 255 always failed to match such a class; however it should
2936     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2937    
2938     (ii) A negated character class with a single character < 255 is coded as
2939     "not this character" (OP_NOT). This wasn't working properly when the test
2940     character was multibyte, either singly or repeated.
2941    
2942     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2943     mode, for example: \x{100}{2,3}.
2944    
2945     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2946     singly or repeated) now correctly test multibyte characters. However,
2947     PCRE doesn't recognize any characters with values greater than 255 as
2948     digits, spaces, or word characters. Such characters always match \D, \S,
2949     and \W, and never match \d, \s, or \w.
2950    
2951     (v) Classes may now contain characters and character ranges with values
2952     greater than 255. For example: [ab\x{100}-\x{400}].
2953    
2954     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2955     PCRE in UTF-8 mode.
2956    
2957     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2958     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2959     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2960     value.)
2961    
2962     53. The single man page has become too large. I have therefore split it up into
2963     a number of separate man pages. These also give rise to individual HTML pages;
2964     these are now put in a separate directory, and there is an index.html page that
2965     lists them all. Some hyperlinking between the pages has been installed.
2966    
2967     54. Added convenience functions for handling named capturing parentheses.
2968    
2969     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2970     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2971     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2972     are faulted.
2973    
2974     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2975     calling configure. These values are used when compiling the dftables.c program
2976     which is run to generate the source of the default character tables. They
2977     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2978     you will need to set these values.
2979    
2980     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2981    
2982    
2983     Version 3.9 02-Jan-02
2984 nigel 61 ---------------------
2985    
2986     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2987    
2988     2. If --disable-static was given, the building process failed when trying to
2989     build pcretest and pcregrep. (For some reason it was using libtool to compile
2990     them, which is not right, as they aren't part of the library.)
2991    
2992    
2993 nigel 59 Version 3.8 18-Dec-01
2994     ---------------------
2995    
2996     1. The experimental UTF-8 code was completely screwed up. It was packing the
2997     bytes in the wrong order. How dumb can you get?
2998    
2999    
3000 nigel 57 Version 3.7 29-Oct-01
3001     ---------------------
3002    
3003     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3004     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3005     this didn't happen under Solaris 8, where I normally test things.
3006    
3007 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3008     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3009     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3010     this fix an hour or so after the initial 3.7 release.)
3011 nigel 57
3012 nigel 59
3013 nigel 55 Version 3.6 23-Oct-01
3014     ---------------------
3015    
3016     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3017     offsets passed as NULL with zero offset count.
3018    
3019     2. The config.guess and config.sub files had not been updated when I moved to
3020     the latest autoconf.
3021    
3022    
3023 nigel 53 Version 3.5 15-Aug-01
3024     ---------------------
3025 nigel 5
3026 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3027     had been forgotten.
3028    
3029     2. By using declared but undefined structures, we can avoid using "void"
3030     definitions in pcre.h while keeping the internal definitions of the structures
3031     private.
3032    
3033     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3034     user point of view, this means that both static and shared libraries are built
3035     by default, but this can be individually controlled. More of the work of
3036     handling this static/shared cases is now inside libtool instead of PCRE's make
3037     file.
3038    
3039     4. The pcretest utility is now installed along with pcregrep because it is
3040     useful for users (to test regexs) and by doing this, it automatically gets
3041     relinked by libtool. The documentation has been turned into a man page, so
3042     there are now .1, .txt, and .html versions in /doc.
3043    
3044     5. Upgrades to pcregrep:
3045     (i) Added long-form option names like gnu grep.
3046     (ii) Added --help to list all options with an explanatory phrase.
3047     (iii) Added -r, --recursive to recurse into sub-directories.
3048     (iv) Added -f, --file to read patterns from a file.
3049    
3050     6. pcre_exec() was referring to its "code" argument before testing that
3051     argument for NULL (and giving an error if it was NULL).
3052    
3053     7. Upgraded Makefile.in to allow for compiling in a different directory from
3054     the source directory.
3055    
3056     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3057     options bits, the pointer it was passed was to an int instead of to an unsigned
3058     long int. This mattered only on 64-bit systems.
3059    
3060     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3061     generated) instead of pcre.in, which it its source. Also made the same change
3062     in several of the .c files.
3063    
3064     10. A new release of gcc defines printf() as a macro, which broke pcretest
3065     because it had an ifdef in the middle of a string argument for printf(). Fixed
3066     by using separate calls to printf().
3067    
3068     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3069     script, to force use of CR or LF instead of \n in the source. On non-Unix
3070     systems, the value can be set in config.h.
3071    
3072     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3073     absolute limit. Changed the text of the error message to make this clear, and
3074     likewise updated the man page.
3075    
3076     13. The limit of 99 on the number of capturing subpatterns has been removed.
3077     The new limit is 65535, which I hope will not be a "real" limit.
3078    
3079    
3080 nigel 51 Version 3.4 22-Aug-00
3081     ---------------------
3082    
3083     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3084    
3085     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3086    
3087    
3088 nigel 49 Version 3.3 01-Aug-00
3089     ---------------------
3090    
3091     1. If an octal character was given, but the value was greater than \377, it
3092     was not getting masked to the least significant bits, as documented. This could
3093     lead to crashes in some systems.
3094    
3095     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3096     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3097    
3098     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3099     These just pass their arguments on to (pcre_free)(), but they are provided
3100     because some uses of PCRE bind it to non-C systems that can call its functions,
3101     but cannot call free() or pcre_free() directly.
3102    
3103     4. Add "make test" as a synonym for "make check". Corrected some comments in
3104     the Makefile.
3105    
3106     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3107     Makefile.
3108    
3109     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3110     command called pgrep for grepping around the active processes.
3111    
3112     7. Added the beginnings of support for UTF-8 character strings.
3113    
3114     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3115     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3116     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3117     out for the ar command.)
3118    
3119    
3120 nigel 47 Version 3.2 12-May-00
3121     ---------------------
3122    
3123     This is purely a bug fixing release.
3124    
3125     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3126     of ZA. This was just one example of several cases that could provoke this bug,
3127     which was introduced by change 9 of version 2.00. The code for breaking
3128     infinite loops after an iteration that matches an empty string was't working
3129     correctly.
3130    
3131     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3132     when matched against abbab (for example). After matching an empty string, it
3133     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3134     caused it to match further down the string than it should.
3135    
3136     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3137     was there because it doesn't seem to be needed, and it causes trouble on some
3138     systems, as it is not a Standard C header. It has been removed.
3139    
3140     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3141     were reported on the Macintosh. The changes were from
3142    
3143     while ((c = *(++ptr)) != 0 && c != '\n');
3144     to
3145     while ((c = *(++ptr)) != 0 && c != '\n') ;
3146    
3147     Totally extraordinary, but if that's what it takes...
3148    
3149     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3150     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3151     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3152     assumes the way PCRE uses memmove() (always moving upwards).
3153    
3154     6. PCRE is being used in one environment where strchr() is not available. There
3155     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3156     faster code anyway.
3157    
3158    
3159 nigel 45 Version 3.1 09-Feb-00
3160     ---------------------
3161    
3162     The only change in this release is the fixing of some bugs in Makefile.in for
3163     the "install" target:
3164    
3165     (1) It was failing to install pcreposix.h.
3166    
3167     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3168    
3169    
3170 nigel 43 Version 3.0 01-Feb-00
3171     ---------------------
3172 nigel 41
3173     1. Add support for the /+ modifier to perltest (to output $` like it does in
3174     pcretest).
3175    
3176     2. Add support for the /g modifier to perltest.
3177    
3178     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3179     matches null strings.
3180    
3181     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3182     pattern. Perl treats empty patterns specially - it reuses the most recent
3183     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3184     effect.
3185    
3186     5. The POSIX interface was broken in that it was just handing over the POSIX
3187     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3188     required a bigger vector, with some working space on the end. This means that
3189     the POSIX wrapper now has to get and free some memory, and copy the results.
3190    
3191 nigel 43 6. Added some simple autoconf support, placing the test data and the
3192     documentation in separate directories, re-organizing some of the
3193     information files, and making it build pcre-config (a GNU standard). Also added
3194     libtool support for building PCRE as a shared library, which is now the
3195     default.
3196 nigel 41
3197 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3198     09 are not valid octal constants. Single digits will be used for minor values
3199     less than 10.
3200    
3201     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3202     existing programs that set these in the POSIX interface can use PCRE without
3203     modification.
3204    
3205     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3206     return all that pcre_info() returns, plus additional data. The pcre_info()
3207     function is retained for compatibility, but is considered to be obsolete.
3208    
3209     10. Added experimental recursion feature (?R) to handle one common case that
3210     Perl 5.6 will be able to do with (?p{...}).
3211    
3212     11. Added support for POSIX character classes like [:alpha:], which Perl is
3213     adopting.
3214    
3215    
3216 nigel 39 Version 2.08 31-Aug-99
3217     ----------------------
3218    
3219     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3220     trying to match at the startoffset position, but instead was moving forward to
3221     the next newline as if a previous match had failed.
3222    
3223     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3224     and could get into a loop if a null string was matched other than at the start
3225     of the subject.
3226    
3227     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3228     be distinguished at compile time, and for completeness also added PCRE_DATE.
3229    
3230     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3231     in GnuWin32 environments.
3232    
3233    
3234 nigel 37 Version 2.07 29-Jul-99
3235     ----------------------
3236    
3237     1. The documentation is now supplied in plain text form and HTML as well as in
3238     the form of man page sources.
3239    
3240     2. C++ compilers don't like assigning (void *) values to other pointer types.
3241     In particular this affects malloc(). Although there is no problem in Standard
3242     C, I've put in casts to keep C++ compilers happy.
3243    
3244     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3245     should be (const char *).
3246    
3247     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3248     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3249     However, I haven't made this a standard facility. The documentation doesn't
3250     mention it, and the Makefile doesn't support it.
3251    
3252     5. The Makefile now contains an "install" target, with editable destinations at
3253     the top of the file. The pcretest program is not installed.
3254    
3255     6. pgrep -V now gives the PCRE version number and date.
3256    
3257     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3258     causing the entire string to be ignored, instead of just the last character.
3259    
3260     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3261     non-matching string, it can take a very, very long time, even for strings of
3262     quite modest length, because of the nested recursion. PCRE now does better in
3263     some of these cases. It does this by remembering the last required literal
3264     character in the pattern, and pre-searching the subject to ensure it is present
3265     before running the real match. In other words, it applies a heuristic to detect
3266     some types of certain failure quickly, and in the above example, if presented
3267     with a string that has no trailing " it gives "no match" very quickly.
3268    
3269     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3270     other alternatives are tried instead.
3271    
3272    
3273 nigel 35 Version 2.06 09-Jun-99
3274     ----------------------
3275    
3276     1. Change pcretest's output for amount of store used to show just the code
3277     space, because the remainder (the data block) varies in size between 32-bit and
3278     64-bit systems.
3279    
3280     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3281     start matching at. This allows lookbehinds to work when searching for multiple
3282     occurrences in a string.
3283    
3284     3. Added additional options to pcretest for testing multiple occurrences:
3285    
3286     /+ outputs the rest of the string that follows a match
3287     /g loops for multiple occurrences, using the new startoffset argument
3288     /G loops for multiple occurrences by passing an incremented pointer
3289    
3290     4. PCRE wasn't doing the "first character" optimization for patterns starting
3291     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3292     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3293     the letter 'x'. On long subject strings, this gives a significant speed-up.
3294    
3295    
3296 nigel 33 Version 2.05 21-Apr-99
3297     ----------------------
3298    
3299     1. Changed the type of magic_number from int to long int so that it works
3300     properly on 16-bit systems.
3301    
3302     2. Fixed a bug which caused patterns starting with .* not to work correctly
3303     when the subject string contained newline characters. PCRE was assuming
3304     anchoring for such patterns in all cases, which is not correct because .* will
3305     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3306     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3307     must be retried after every newline in the subject.
3308    
3309    
3310 nigel 31 Version 2.04 18-Feb-99
3311     ----------------------
3312    
3313     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3314     computation of the store needed to hold the pattern was incorrect (too large).
3315     If such patterns were nested a few deep, this could multiply and become a real
3316     problem.
3317    
3318     2. Added /M option to pcretest to show the memory requirement of a specific
3319     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3320    
3321     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3322     compiled in such a way that the backtracking after subsequent failure was
3323     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3324     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3325    
3326    
3327 nigel 29 Version 2.03 02-Feb-99
3328     ----------------------
3329    
3330     1. Fixed typo and small mistake in man page.
3331    
3332 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3333     LICENCE file containing the conditions.
3334 nigel 29
3335     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3336     Perl, that is the internal \ allows the delimiter to be included in the
3337     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3338     the final delimiter, add \ to the end of the pattern (to test the error).
3339    
3340     4. Added the convenience functions for extracting substrings after a successful
3341     match. Updated pcretest to make it able to test these functions.
3342    
3343    
3344 nigel 27 Version 2.02 14-Jan-99
3345     ----------------------
3346    
3347     1. Initialized the working variables associated with each extraction so that
3348     their saving and restoring doesn't refer to uninitialized store.
3349    
3350     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3351     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3352     fix the problem.
3353    
3354     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3355     calls, and wasn't printing the correct value for compiling calls. Increased the
3356     default value of LOOPREPEAT, and the number of significant figures in the
3357     times.
3358    
3359     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3360    
3361     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3362     a building problem on Windows NT with a FAT file system.
3363    
3364    
3365 nigel 25 Version 2.01 21-Oct-98
3366     ----------------------
3367    
3368     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3369     to character tables built by pcre_maketables() in the current locale. If NULL
3370     is passed, the default tables are used.
3371    
3372    
3373 nigel 23 Version 2.00 24-Sep-98
3374 nigel 21 ----------------------
3375    
3376 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3377     it any more.
3378    
3379     2. Allow quantification of (?>) groups, and make it work correctly.
3380    
3381     3. The first character computation wasn't working for (?>) groups.
3382    
3383     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3384     end of the subject) and add 5.005's \z, which really does match only at the
3385     very end of the subject.
3386    
3387     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3388    
3389     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3390     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3391     localized options. All options to pcre_study() were also removed.
3392    
3393     7. Add other new features from 5.005:
3394    
3395     $(?<= positive lookbehind
3396     $(?<! negative lookbehind
3397     (?imsx-imsx) added the unsetting capability
3398     such a setting is global if at outer level; local otherwise
3399     (?imsx-imsx:) non-capturing groups with option setting
3400     (?(cond)re|re) conditional pattern matching
3401    
3402     A backreference to itself in a repeated group matches the previous
3403     captured string.
3404    
3405     8. General tidying up of studying (both automatic and via "study")
3406     consequential on the addition of new assertions.
3407    
3408     9. As in 5.005, unlimited repeated groups that could match an empty substring
3409     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3410     runtime if any iteration does actually match an empty substring.
3411    
3412     10. Include the RunTest script in the distribution.
3413    
3414     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3415     discrepancies, some of which were old and were also with respect to 5.004. They
3416     have now been fixed.
3417    
3418    
3419     Version 1.09 28-Apr-98
3420     ----------------------
3421    
3422 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3423     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3424     program crashes, or just wrong answers. This did not apply to negated classes
3425     containing more than one character, or to minima other than one.
3426    
3427    
3428 nigel 19 Version 1.08 27-Mar-98
3429     ----------------------
3430    
3431     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3432    
3433     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3434     latter must appear before anything that relies on it in the pattern.
3435    
3436    
3437 nigel 17 Version 1.07 16-Feb-98
3438     ----------------------
3439    
3440     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3441     repeat of a potentially empty string).
3442    
3443    
3444 nigel 15 Version 1.06 23-Jan-98
3445     ----------------------
3446    
3447     1. Added Markus Oberhumer's little patches for C++.
3448    
3449     2. Literal strings longer than 255 characters were broken.
3450    
3451    
3452 nigel 13 Version 1.05 23-Dec-97
3453     ----------------------
3454    
3455     1. Negated character classes containing more than one character were failing if
3456     PCRE_CASELESS was set at run time.
3457    
3458    
3459 nigel 11 Version 1.04 19-Dec-97
3460     ----------------------
3461    
3462     1. Corrected the man page, where some "const" qualifiers had been omitted.
3463    
3464     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3465     input syntax.
3466    
3467     3. Fixed memory leak which occurred when a regex with back references was
3468     matched with an offsets vector that wasn't big enough. The temporary memory
3469     that is used in this case wasn't being freed if the match failed.
3470    
3471     4. Tidied pcretest to ensure it frees memory that it gets.
3472    
3473     5. Temporary memory was being obtained in the case where the passed offsets
3474     vector was exactly big enough.
3475    
3476     6. Corrected definition of offsetof() from change 5 below.
3477    
3478     7. I had screwed up change 6 below and broken the rules for the use of
3479     setjmp(). Now fixed.
3480    
3481    
3482 nigel 9 Version 1.03 18-Dec-97
3483     ----------------------
3484    
3485     1. A erroneous regex with a missing opening parenthesis was correctly
3486     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3487     on some systems.
3488    
3489     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3490     it was reported that one broken compiler failed on the former because "code" is
3491     also an independent variable.
3492    
3493     3. The erroneous regex a[]b caused an array overrun reference.
3494    
3495     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3496     fail on data ending with that character. (It was going on too far, and checking
3497     the next character, typically a binary zero.) This was specific to the
3498     optimized code for single-character negative classes.
3499    
3500     5. Added a contributed patch from the TIN world which does the following:
3501    
3502     + Add an undef for memmove, in case the the system defines a macro for it.
3503    
3504     + Add a definition of offsetof(), in case there isn't one. (I don't know
3505     the reason behind this - offsetof() is part of the ANSI standard - but
3506     it does no harm).
3507    
3508     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3509     most of the places where whitespace preceded '#'. I have given up and
3510     allowed the remaining 2 cases to be at the margin.
3511    
3512     + Rename some variables in pcre to eliminate shadowing. This seems very
3513     pedantic, but does no harm, of course.
3514    
3515     6. Moved the call to setjmp() into its own function, to get rid of warnings
3516     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3517    
3518     7. Constructs such as \d{8,} were compiling into the equivalent of
3519 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3520 nigel 9 outcome, but in this particular case used more store than had been allocated,
3521     which caused the bug to be discovered because it threw up an internal error.
3522    
3523     8. The debugging code in both pcre and pcretest for outputting the compiled
3524     form of a regex was going wrong in the case of back references followed by
3525     curly-bracketed repeats.
3526    
3527    
3528 nigel 7 Version 1.02 12-Dec-97
3529     ----------------------
3530    
3531     1. Typos in pcre.3 and comments in the source fixed.
3532    
3533     2. Applied a contributed patch to get rid of places where it used to remove
3534     'const' from variables, and fixed some signed/unsigned and uninitialized
3535     variable warnings.
3536    
3537     3. Added the "runtest" target to Makefile.
3538    
3539     4. Set default compiler flag to -O2 rather than just -O.
3540    
3541    
3542 nigel 5 Version 1.01 19-Nov-97
3543     ----------------------
3544    
3545     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3546     like /([ab]*)*/, that is, for classes with more than one character in them.
3547    
3548     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3549     as /((?>a*))*/ (a PCRE_EXTRA facility).
3550    
3551    
3552     Version 1.00 18-Nov-97
3553     ----------------------
3554    
3555     1. Added compile-time macros to support systems such as SunOS4 which don't have
3556     memmove() or strerror() but have other things that can be used instead.
3557    
3558     2. Arranged that "make clean" removes the executables.
3559    
3560    
3561 nigel 3 Version 0.99 27-Oct-97
3562     ----------------------
3563    
3564     1. Fixed bug in code for optimizing classes with only one character. It was
3565     initializing a 32-byte map regardless, which could cause it to run off the end
3566     of the memory it had got.
3567    
3568     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3569    
3570    
3571     Version 0.98 22-Oct-97
3572     ----------------------
3573    
3574     1. Fixed bug in code for handling temporary memory usage when there are more
3575     back references than supplied space in the ovector. This could cause segfaults.
3576    
3577    
3578     Version 0.97 21-Oct-97
3579     ----------------------
3580    
3581     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3582    
3583     2. Optimized negated single characters not to use a bit map.
3584    
3585     3. Brought error texts together as macro definitions; clarified some of them;
3586     fixed one that was wrong - it said "range out of order" when it meant "invalid
3587     escape sequence".
3588    
3589     4. Changed some char * arguments to const char *.
3590    
3591     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3592    
3593     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3594     pcretest.
3595    
3596    
3597     Version 0.96 16-Oct-97
3598     ----------------------
3599    
3600     1. Added a simple "pgrep" utility to the distribution.
3601    
3602     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3603     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3604     where "ddd" means "one or more decimal digits".
3605    
3606     3. Fixed serious bug. If a pattern had a back reference, but the call to
3607     pcre_exec() didn't supply a large enough ovector to record the related
3608     identifying subpattern, the match always failed. PCRE now remembers the number
3609     of the largest back reference, and gets some temporary memory in which to save
3610     the offsets during matching if necessary, in order to ensure that
3611     backreferences always work.
3612    
3613     4. Increased the compatibility with Perl in a number of ways:
3614    
3615     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3616     to request this handling. The option can be set at compile or exec time.
3617    
3618     (b) $ matches before a terminating newline by default; an option
3619     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3620     mode). The option can be set at compile or exec time.
3621    
3622     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3623     the same as Perl's. If the decimal number it represents is less than 10
3624     or there aren't that many previous left capturing parentheses, an octal
3625     escape is read. Inside a character class, it's always an octal escape,
3626     even if it is a single digit.
3627    
3628     (d) An escaped but undefined alphabetic character is taken as a literal,
3629     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3630     escapes.
3631    
3632     (e) {0} is now permitted. (The previous item is removed from the compiled
3633     pattern).
3634    
3635     5. Changed all the names of code files so that the basic parts are no longer
3636     than 10 characters, and abolished the teeny "globals.c" file.
3637    
3638     6. Changed the handling of character classes; they are now done with a 32-byte
3639     bit map always.
3640    
3641     7. Added the -d and /D options to pcretest to make it possible to look at the
3642     internals of compilation without having to recompile pcre.
3643    
3644    
3645     Version 0.95 23-Sep-97
3646     ----------------------
3647    
3648     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3649     \x20 at the start of a run of normal characters. These were being treated as
3650     real characters, instead of the source characters being re-checked.
3651    
3652    
3653     Version 0.94 18-Sep-97
3654     ----------------------
3655    
3656     1. The functions are now thread-safe, with the caveat that the global variables
3657     containing pointers to malloc() and free() or alternative functions are the
3658     same for all threads.
3659    
3660     2. Get pcre_study() to generate a bitmap of initial characters for non-
3661     anchored patterns when this is possible, and use it if passed to pcre_exec().
3662    
3663    
3664     Version 0.93 15-Sep-97
3665     ----------------------
3666    
3667     1. /(b)|(:+)/ was computing an incorrect first character.
3668    
3669     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3670     but not actually doing anything yet.
3671    
3672     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3673     as Perl does (e.g. [-az] or [az-]).
3674    
3675     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3676     all possible positions.
3677    
3678     5. Split up into different modules to avoid including unneeded functions in a
3679     compiled binary. However, compile and exec are still in one module. The "study"
3680     function is split off.
3681    
3682     6. The character tables are now in a separate module whose source is generated
3683     by an auxiliary program - but can then be edited by hand if required. There are
3684     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3685     toupper() in the code.
3686    
3687     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3688     make them global. Abolish the function for setting them, as the caller can now
3689     set them directly.
3690    
3691    
3692     Version 0.92 11-Sep-97
3693     ----------------------
3694    
3695     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3696     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3697    
3698     2. Caseless matching was not working in character classes if the characters in
3699     the pattern were in upper case.
3700    
3701     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3702    
3703     4. Make PCRE_ANCHORED public and accept as a compile option.
3704    
3705     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3706     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3707     pass them.
3708    
3709     6. Give an error if bad option bits passed at compile or run time.
3710    
3711     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3712     pcretest to cause it to pass that flag.
3713    
3714     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3715     options, and the first character, if set.
3716    
3717     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3718    
3719    
3720     Version 0.91 10-Sep-97
3721     ----------------------
3722    
3723     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3724     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3725    
3726     2. PCRE was looping on encountering an indefinitely repeated back reference to
3727     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3728     Perl does - treats the match as successful.
3729    
3730     ****

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