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Revision 478 - (hide annotations) (download)
Sun Jan 3 16:05:13 2010 UTC (4 years, 7 months ago) by ph10
File size: 178075 byte(s)
Update configure.ac to solve libbz2 problem under Win32.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 471 Version 8.01 11-Dec-09
5     ----------------------
6    
7     1. If a pattern contained a conditional subpattern with only one branch (in
8 ph10 473 particular, this includes all (DEFINE) patterns), a call to pcre_study()
9     computed the wrong minimum data length (which is of course zero for such
10 ph10 471 subpatterns).
11 ph10 473
12     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
13 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
14     "internal error: code overflow at offset...". This happened only when
15 ph10 473 the reset was to the original external option setting. (An optimization
16     abstracts leading options settings into an external setting, which was the
17 ph10 472 cause of this.)
18 ph10 471
19 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
20     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
21     assertion pattern did not match (meaning that the assertion was true), it
22     was incorrectly treated as false if the SKIP had been reached during the
23     matching. This also applied to assertions used as conditions.
24 ph10 471
25 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
26     assertion subpattern, including such a pattern used as a condition,
27     unpredictable results occurred, instead of the error return
28     PCRE_ERROR_DFA_UITEM.
29 ph10 478
30 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
31     situation when an empty string is matched. It now does the fancy magic
32 ph10 478 stuff that is necessary.
33    
34     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
35 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
36 ph10 478
37 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
38     as part of something else:
39 ph10 478
40     (a) Change DEBUG to PCRE_DEBUG.
41    
42     (b) In pcre_compile(), rename the member of the "branch_chain" structure
43     called "current" as "current_branch", to prevent a collision with the
44 ph10 475 Linux macro when compiled as a kernel module.
45 ph10 478
46     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
47     prevent a collision with the Linux macro when compiled as a kernel
48 ph10 475 module.
49 ph10 478
50 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
51     cast potentially large values to (double). This has been changed to that
52 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
53     instead, thus avoiding the use of floating point arithmetic. (There is no
54     other use of FP in PCRE.) If int64_t is not found, the fallback is to
55     double.
56    
57     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
58 ph10 476 2005 (difference between two addresses compared to an unsigned value).
59 ph10 473
60 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
61     custom one, because of the following reported problem in Windows:
62 ph10 473
63 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
64     under Win32.
65     - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
66     therefore missing the function definition.
67     - The compiler thus generates a "C" signature for the test function.
68     - The linker fails to find the "C" function.
69     - PCRE fails to configure if asked to do so against libbz2.
70    
71    
72 ph10 469 Version 8.00 19-Oct-09
73 ph10 418 ----------------------
74    
75     1. The table for translating pcre_compile() error codes into POSIX error codes
76 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
77     being within the table. This could lead to an OK return being given in
78 ph10 418 error.
79 ph10 461
80     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
81     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
82     in a Windows environment.
83    
84 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
85     zero, as does GNU grep. However, pcregrep was also printing all files when
86     --files-with-matches was added. Now, when both options are given, it prints
87     counts only for those files that have at least one match. (GNU grep just
88 ph10 461 prints the file name in this circumstance, but including the count seems
89     more useful - otherwise, why use --count?) Also ensured that the
90 ph10 420 combination -clh just lists non-zero counts, with no names.
91 ph10 461
92     4. The long form of the pcregrep -F option was incorrectly implemented as
93     --fixed_strings instead of --fixed-strings. This is an incompatible change,
94     but it seems right to fix it, and I didn't think it was worth preserving
95     the old behaviour.
96    
97     5. The command line items --regex=pattern and --regexp=pattern were not
98 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
99 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
100 ph10 422 which are compatible with GNU grep; these now work.
101 ph10 461
102     6. No libpcreposix.pc file was created for pkg-config; there was just
103 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
104 ph10 461
105 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
106 ph10 461 when UCP support is not needed, by modifying the Python script that
107 ph10 425 generates it from Unicode data files. This should not matter if the module
108     is correctly used as a library, but I received one complaint about 50K of
109     unwanted data. My guess is that the person linked everything into his
110     program rather than using a library. Anyway, it does no harm.
111 ph10 461
112 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
113 ph10 461 was a minimum greater than 1 for a wide character in a possessive
114 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
115     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
116     character. Chaos in the form of incorrect output or a compiling loop could
117     result.
118 ph10 461
119 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
120 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
121 ph10 426 partially matched by this function. In addition, if there are at least two
122 ph10 435 slots in the offset vector, the offset of the earliest inspected character
123     for the match and the offset of the end of the subject are set in them when
124 ph10 461 PCRE_ERROR_PARTIAL is returned.
125    
126 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
127     synonymous with PCRE_PARTIAL, for backwards compatibility, and
128     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
129 ph10 462 and may be more useful for multi-segment matching.
130 ph10 461
131     11. Partial matching with pcre_exec() is now more intuitive. A partial match
132     used to be given if ever the end of the subject was reached; now it is
133     given only if matching could not proceed because another character was
134     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
135     string "Z", which now yields "no match" instead of "partial match". In the
136     case of pcre_dfa_exec(), "no match" is given if every matching path for the
137     final character ended with (*FAIL).
138    
139 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
140 ph10 461 if the pattern had a "must contain" character that was already found in the
141 ph10 428 earlier partial match, unless partial matching was again requested. For
142     example, with the pattern /dog.(body)?/, the "must contain" character is
143     "g". If the first part-match was for the string "dog", restarting with
144 ph10 435 "sbody" failed. This bug has been fixed.
145 ph10 461
146     13. The string returned by pcre_dfa_exec() after a partial match has been
147     changed so that it starts at the first inspected character rather than the
148     first character of the match. This makes a difference only if the pattern
149     starts with a lookbehind assertion or \b or \B (\K is not supported by
150     pcre_dfa_exec()). It's an incompatible change, but it makes the two
151 ph10 435 matching functions compatible, and I think it's the right thing to do.
152 ph10 461
153 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
154 ph10 461 so that the demonstration program is easily available in environments where
155     PCRE has not been installed from source.
156    
157 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
158 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
159     library.
160 ph10 461
161 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
162 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
163 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
164 ph10 433 these options useful.
165 ph10 461
166     17. If a caller to the POSIX matching function regexec() passes a non-zero
167 ph10 438 value for nmatch with a NULL value for pmatch, the value of
168 ph10 461 nmatch is forced to zero.
169    
170 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
171 ph10 461 the diff command, as RunTest does. It now checks in the same way as
172 ph10 437 RunTest, and also checks for the -b option.
173 ph10 461
174 ph10 438 19. If an odd number of negated classes containing just a single character
175     interposed, within parentheses, between a forward reference to a named
176 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
177     an internal error, complaining that it could not find the referenced
178 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
179 ph10 461 [The bug was that it was starting one character too far in when skipping
180     over the character class, thus treating the ] as data rather than
181     terminating the class. This meant it could skip too much.]
182    
183 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
184 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
185 ph10 442 to have an empty string match not at the start, even when the pattern is
186 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
187    
188 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
189 ph10 461 than the maximum at the outer level, the higher number was returned, but
190     with unset values at the outer level. The correct (outer level) value is
191 ph10 446 now given.
192 ph10 461
193 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
194     PCRE did not set those parentheses (unlike Perl). I have now found a way to
195     make it do so. The string so far is captured, making this feature
196     compatible with Perl.
197 ph10 461
198     23. The tests have been re-organized, adding tests 11 and 12, to make it
199 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
200 ph10 461
201 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
202 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
203     does. Neither allows recursion.
204    
205     25. I finally figured out how to implement a request to provide the minimum
206     length of subject string that was needed in order to match a given pattern.
207     (It was back references and recursion that I had previously got hung up
208     on.) This code has now been added to pcre_study(); it finds a lower bound
209 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
210     bound, but using it to avoid searching strings that are too short does give
211     some useful speed-ups. The value is available to calling programs via
212     pcre_fullinfo().
213 ph10 461
214 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
215     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
216     study optimizations had never been tested with that matching function.
217     Oops. What is worse, even when it was passed study data, there was a bug in
218     pcre_dfa_exec() that meant it never actually used it. Double oops. There
219     were also very few tests of studied patterns with pcre_dfa_exec().
220 ph10 461
221 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
222     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
223     on the other side of the coin, they are no longer allowed to have different
224     names, because these cannot be distinguished in PCRE, and this has caused
225     confusion. (This is a difference from Perl.)
226 ph10 461
227     28. When duplicate subpattern names are present (necessarily with different
228     numbers, as required by 27 above), and a test is made by name in a
229     conditional pattern, either for a subpattern having been matched, or for
230     recursion in such a pattern, all the associated numbered subpatterns are
231 ph10 459 tested, and the overall condition is true if the condition is true for any
232     one of them. This is the way Perl works, and is also more like the way
233     testing by number works.
234 ph10 418
235 ph10 461
236 ph10 412 Version 7.9 11-Apr-09
237 ph10 376 ---------------------
238    
239 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
240 ph10 376 (pcretest), all targets were linked against these libraries. This included
241     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
242     libraries. This caused unwanted dependencies to be created. This problem
243 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
244 ph10 376 pcretest is linked with readline.
245 ph10 392
246 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
247     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
248     moved outside it again, because FALSE and TRUE are already defined in AIX,
249     but BOOL is not.
250 ph10 392
251     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
252 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
253 ph10 392
254 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
255     hyphens) following file names and line numbers when outputting matching
256 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
257 ph10 376 wording for the --colour (or --color) option.
258 ph10 392
259 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
260     was not coloured; this is different to GNU grep, so I have changed it to be
261     the same.
262 ph10 392
263 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
264 ph10 392 each matching line was coloured. Now it goes on to look for further matches
265     of any of the test patterns, which is the same behaviour as GNU grep.
266    
267     7. A pattern that could match an empty string could cause pcregrep to loop; it
268     doesn't make sense to accept an empty string match in pcregrep, so I have
269 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
270     seems to be how GNU grep behaves.
271 ph10 392
272 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
273 ph10 392 start or after a newline", because the conditional assertion was not being
274     correctly handled. The rule now is that both the assertion and what follows
275     in the first alternative must satisfy the test.
276    
277 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
278 ph10 399 condition was an assertion, PCRE could crash during matching, both with
279     pcre_exec() and pcre_dfa_exec().
280 ph10 392
281     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
282     used for matching.
283    
284     11. Unicode property support in character classes was not working for
285 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
286 ph10 388
287 ph10 392 12. Added the -M command line option to pcretest.
288    
289 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
290 ph10 389
291     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
292 ph10 390
293 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
294 ph10 390 wrapper.
295 ph10 392
296 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
297 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
298 ph10 391 string constants.
299 ph10 405
300 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
301     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
302 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
303     these, but not everybody uses configure.
304    
305     19. A conditional group that had only one branch was not being correctly
306     recognized as an item that could match an empty string. This meant that an
307     enclosing group might also not be so recognized, causing infinite looping
308     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
309     with the subject "ab", where knowledge that the repeated group can match
310 ph10 396 nothing is needed in order to break the loop.
311 ph10 405
312 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
313 ph10 405 exec(), but without supplying a callout function, matching went wrong.
314    
315     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
316     leak if the size of the offset vector was greater than 30. When the vector
317     is smaller, the saved offsets during recursion go onto a local stack
318     vector, but for larger vectors malloc() is used. It was failing to free
319     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
320 ph10 400 error, in fact).
321 ph10 405
322 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
323 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
324     problem, but was untidy.
325 ph10 376
326 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
327     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
328     included within another project.
329 ph10 411
330 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
331     slightly modified by me:
332 ph10 411
333     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
334     not building pcregrep.
335    
336 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
337 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
338    
339 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
340     duplicate group numbers, could behave incorrectly or give incorrect errors,
341     because when scanning forward to find the reference group, PCRE was not
342     taking into account the duplicate group numbers. A pattern such as
343     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
344 ph10 411
345     26. Changed a few more instances of "const unsigned char *" to USPTR, making
346     the feature of a custom pointer more persuasive (as requested by a user).
347 ph10 416
348 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
349 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
350     pre-defined.
351 ph10 392
352 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
353    
354 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
355     in the configuration summary.
356 ph10 405
357 ph10 411
358 ph10 374 Version 7.8 05-Sep-08
359 ph10 349 ---------------------
360    
361     1. Replaced UCP searching code with optimized version as implemented for Ad
362     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
363 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
364     to 5 times on some simple patterns that I tested. Permission was given to
365     distribute the MultiStage2.py script that generates the tables (it's not in
366     the tarball, but is in the Subversion repository).
367 ph10 349
368 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
369     scripts.
370 ph10 358
371 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
372     a group with a zero qualifier. The result of the study could be incorrect,
373 ph10 358 or the function might crash, depending on the pattern.
374    
375     4. Caseless matching was not working for non-ASCII characters in back
376 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
377 ph10 358 It now works when Unicode Property Support is available.
378    
379 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
380     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
381     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
382 ph10 358 truncation.
383 ph10 349
384 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
385    
386 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
387     pointers, in case they are 64-bit values.
388 ph10 371
389     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
390     test 2 if it fails.
391    
392 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
393 ph10 371 and a #define of that name to empty if it is not externally set. This is to
394     allow users of MSVC to set it if necessary.
395    
396     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
397 ph10 359 the convenience functions in the pcre_get.c source file.
398 ph10 371
399 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
400     could cause overwriting and/or a crash. This command provoked a crash in
401 ph10 371 some environments:
402    
403     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
404    
405 ph10 360 This potential security problem was recorded as CVE-2008-2371.
406 ph10 371
407 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
408     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
409 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
410 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
411     pcretest so that it places the subject at the end of its malloc-ed buffer.
412 ph10 371
413 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
414 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
415    
416 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
417 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
418     first line. This applied both to normal and DFA matching.
419    
420 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
421 ph10 371 /^[^d]*?$/8 failed to match "abc".
422 ph10 351
423 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
424    
425     17. Make it more clear in the documentation that values returned from
426 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
427 ph10 357
428 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
429 ph10 368
430 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
431     supplied by Stefan Weber. I made a further small update for 7.8 because
432 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
433     replaced by pcre_ucd.c.
434 ph10 371
435 ph10 373
436 ph10 347 Version 7.7 07-May-08
437 ph10 321 ---------------------
438    
439     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
440 ph10 345 a string to a long long, pretend we don't even have a long long." This is
441 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
442 ph10 345
443 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
444     pre-7.6 versions, which defined a global no_arg variable instead of putting
445 ph10 332 it in the RE class. (See also #8 below.)
446 ph10 345
447     3. Remove a line of dead code, identified by coverity and reported by Nuno
448     Lopes.
449    
450 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
451 ph10 321
452 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
453 ph10 345 of files, instead of just to the final components.
454    
455 ph10 324 (2) If there was more than one level of directory, the subdirectories were
456     skipped unless they satisfied the include/exclude conditions. This is
457     inconsistent with GNU grep (and could even be seen as contrary to the
458     pcregrep specification - which I improved to make it absolutely clear).
459     The action now is always to scan all levels of directory, and just
460     apply the include/exclude patterns to regular files.
461 ph10 345
462 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
463 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
464    
465 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
466 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
467 ph10 326 doesn't support NULs in patterns.
468 ph10 345
469     7. Added some missing "const"s to declarations of static tables in
470     pcre_compile.c and pcre_dfa_exec.c.
471    
472 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
473 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
474 ph10 345 first patch. And a third patch - this was a messy problem.)
475 ph10 321
476 ph10 345 9. Applied Craig's patch to remove the use of push_back().
477    
478 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
479     matching function regexec().
480 ph10 345
481     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
482     which, however, unlike Perl's \g{...}, are subroutine calls, not back
483 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
484     Oniguruma does).
485 ph10 345
486     12. Previously, a group with a zero repeat such as (...){0} was completely
487 ph10 335 omitted from the compiled regex. However, this means that if the group
488     was called as a subroutine from elsewhere in the pattern, things went wrong
489 ph10 345 (an internal error was given). Such groups are now left in the compiled
490     pattern, with a new opcode that causes them to be skipped at execution
491 ph10 335 time.
492 ph10 345
493 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
494     to the way PCRE behaves:
495 ph10 345
496 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
497 ph10 345
498     (b) A back reference to an unmatched subpattern matches an empty string
499 ph10 336 (Perl fails the current match path).
500 ph10 345
501 ph10 341 (c) A data ] in a character class must be notated as \] because if the
502 ph10 345 first data character in a class is ], it defines an empty class. (In
503 ph10 341 Perl it is not possible to have an empty class.) The empty class []
504     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
505     The negative empty class [^] matches any one character, independently
506     of the DOTALL setting.
507 ph10 345
508     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
509 ph10 340 non-existent subpattern following a character class starting with ']' and
510     containing () gave an internal compiling error instead of "reference to
511     non-existent subpattern". Fortunately, when the pattern did exist, the
512 ph10 345 compiled code was correct. (When scanning forwards to check for the
513 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
514 ph10 345 the class, so got the count wrong. When actually compiling, the reference
515 ph10 340 was subsequently set up correctly.)
516 ph10 345
517 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
518 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
519     other assertions are supported. I have made pcre_dfa_exec() support
520     (*FAIL).
521    
522 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
523 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
524     cannot be changed at match time, I realized I could make a small
525     improvement to matching performance by compiling OP_ALLANY instead of
526     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
527     on the OP_ANY path.
528    
529     17. Compiling pcretest on Windows with readline support failed without the
530 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
531 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
532    
533 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
534 ph10 345 ncurses library to be included for pcretest when ReadLine support is
535     requested, but also to allow for it to be overridden. This patch came from
536     Daniel Bergström.
537 ph10 347
538 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
539 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
540     any errors with the current Unicode tables. Thanks to Peter Kankowski for
541     spotting this.
542 ph10 324
543 ph10 332
544 ph10 319 Version 7.6 28-Jan-08
545 ph10 300 ---------------------
546    
547 ph10 302 1. A character class containing a very large number of characters with
548     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
549     overflow.
550 ph10 309
551     2. Patch to cut out the "long long" test in pcrecpp_unittest when
552     HAVE_LONG_LONG is not defined.
553    
554 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
555 ph10 304 bring them up to date and include new features. This patch includes:
556 ph10 309
557 ph10 304 - Fixed PH's badly added libz and libbz2 support.
558     - Fixed a problem with static linking.
559 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
560 ph10 304 - Fixed dftables problem and added an option.
561     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
562     HAVE_LONG_LONG.
563     - Added readline support for pcretest.
564 ph10 309 - Added an listing of the option settings after cmake has run.
565    
566 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
567     "pcre.dll" under mingw when using Configure/Make. I added stuff to
568     Makefile.am that cause it to include this special target, without
569     affecting anything else. Note that the same mingw target plus all
570     the other distribution libraries and programs are now supported
571     when configuring with CMake (see 6 below) instead of with
572     Configure/Make.
573 ph10 309
574 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
575     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
576 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
577     solves the problem, but it does no harm.
578 ph10 313
579 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
580 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
581 ph10 314 with CMake, and also correct the comment about stack recursion.
582 ph10 313
583 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
584 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
585     of a program that users should build themselves after PCRE is installed, so
586     building it automatically is not really right. What is more, it gave
587 ph10 312 trouble in some build environments.
588 ph10 300
589 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
590 ph10 308
591 ph10 319
592 ph10 298 Version 7.5 10-Jan-08
593 ph10 263 ---------------------
594    
595     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
596     values in parens when parsing an RE using the C++ wrapper."
597 ph10 286
598 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
599     Characters greater than 255 were excluded from the class instead of being
600     included.
601 ph10 286
602     3. The same bug as (2) above applied to negated POSIX classes such as
603 ph10 265 [:^space:].
604 ph10 286
605 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
606     defined or documented. It seems to have been a typo for PCRE_STATIC, so
607 ph10 286 I have changed it.
608    
609 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
610 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
611     first named subpattern whose name started with "a" (in other words, the
612 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
613     expected" is now given for (?&) (a zero-length name), and this patch also
614     makes it give the same error for \k'' (previously it complained that that
615     was a reference to a non-existent subpattern).
616 ph10 286
617 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
618 ph10 286 this is right because (?- can be followed by option settings as well as by
619 ph10 269 digits. I have, however, made the messages clearer.
620 ph10 286
621 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
622     than the number used in the conditional) now cause a compile-time error.
623     This is actually not compatible with Perl, which accepts such patterns, but
624     treats the conditional as always being FALSE (as PCRE used to), but it
625     seems to me that giving a diagnostic is better.
626 ph10 286
627 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
628 ph10 275 and messages.
629 ph10 286
630     9. Fix two occurrences of "backslash" in comments that should have been
631     "backspace".
632    
633     10. Remove two redundant lines of code that can never be obeyed (their function
634     was moved elsewhere).
635    
636     11. The program that makes PCRE's Unicode character property table had a bug
637     which caused it to generate incorrect table entries for sequences of
638 ph10 277 characters that have the same character type, but are in different scripts.
639 ph10 286 It amalgamated them into a single range, with the script of the first of
640 ph10 277 them. In other words, some characters were in the wrong script. There were
641     thirteen such cases, affecting characters in the following ranges:
642 ph10 286
643 ph10 277 U+002b0 - U+002c1
644     U+0060c - U+0060d
645 ph10 286 U+0061e - U+00612
646 ph10 277 U+0064b - U+0065e
647     U+0074d - U+0076d
648     U+01800 - U+01805
649     U+01d00 - U+01d77
650     U+01d9b - U+01dbf
651     U+0200b - U+0200f
652     U+030fc - U+030fe
653     U+03260 - U+0327f
654     U+0fb46 - U+0fbb1
655     U+10450 - U+1049d
656 ph10 286
657 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
658     compatible with GNU grep in that, if there was more than one match in a
659     line, it showed only the first of them. It now behaves in the same way as
660     GNU grep.
661 ph10 286
662     13. If the -o and -v options were combined for pcregrep, it printed a blank
663     line for every non-matching line. GNU grep prints nothing, and pcregrep now
664     does the same. The return code can be used to tell if there were any
665     non-matching lines.
666    
667 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
668    
669     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
670 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
671 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
672     and both kinds of lookbehind were skipped).
673    
674 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
675 ph10 284 inclusion of <windows.h> to before rather than after the definition of
676     INVALID_FILE_ATTRIBUTES (patch from David Byron).
677 ph10 263
678 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
679 ph10 286 character property caused pcre_compile() to compile bad code, which led at
680     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
681     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
682     caused the error; without that there was no problem.
683 ph10 263
684 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
685 ph10 286
686 ph10 289 19. Added --enable-pcretest-libreadline.
687 ph10 286
688 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
689 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
690 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
691     later patch that removed the other one (the right fix) and added unit tests
692     that check the return values (which was not done before).
693 ph10 292
694 ph10 291 21. Several CMake things:
695 ph10 287
696 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
697 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
698 ph10 288
699 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
700     linked with the newly-built libraries, not previously installed ones.
701 ph10 291
702 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
703 ph10 298
704     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
705     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
706     UTF-8 newline character). The key issue is that the pattern starts .*;
707     this means that the match must be either at the beginning, or after a
708     newline. The bug was in the code for advancing after a failed match and
709     checking that the new position followed a newline. It was not taking
710 ph10 294 account of UTF-8 characters correctly.
711 ph10 298
712     23. PCRE was behaving differently from Perl in the way it recognized POSIX
713     character classes. PCRE was not treating the sequence [:...:] as a
714     character class unless the ... were all letters. Perl, however, seems to
715     allow any characters between [: and :], though of course it rejects as
716     unknown any "names" that contain non-letters, because all the known class
717     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
718     for example, whereas PCRE did not - it did not recognize a POSIX character
719     class. This seemed a bit dangerous, so the code has been changed to be
720     closer to Perl. The behaviour is not identical to Perl, because PCRE will
721     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
722     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
723     Perl does, and where it didn't before.
724    
725 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
726     Windows environments %n is disabled by default.
727 ph10 292
728    
729 ph10 260 Version 7.4 21-Sep-07
730 ph10 230 ---------------------
731    
732     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
733 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
734     LF". That isn't really right - the whole point of the change was to try to
735     help when there was an actual mention of one of the two characters. So now
736     the change happens only if \r or \n (or a literal CR or LF) character is
737 ph10 230 encountered.
738 ph10 231
739     2. The 32-bit options word was also used for 6 internal flags, but the numbers
740     of both had grown to the point where there were only 3 bits left.
741     Fortunately, there was spare space in the data structure, and so I have
742     moved the internal flags into a new 16-bit field to free up more option
743 ph10 230 bits.
744 ph10 231
745     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
746     but did not set the internal JCHANGED flag - either of these is enough to
747     control the way the "get" function works - but the PCRE_INFO_JCHANGED
748     facility is supposed to tell if (?J) was ever used, so now (?J) at the
749 ph10 230 start sets both bits.
750    
751 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
752     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
753 ph10 230
754 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
755    
756     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
757 ph10 233 compatibility, even though it is no longer used.
758 ph10 243
759     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
760 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
761 ph10 259 windows.h file is present (where different names are used). [This was
762 ph10 257 reversed later after testing - see 16 below.]
763 ph10 243
764     8. Changed all #include <config.h> to #include "config.h". There were also
765 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
766 ph10 243
767 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
768 ph10 243 sequence off the lines that it output.
769    
770     10. It was pointed out to me that arrays of string pointers cause lots of
771     relocations when a shared library is dynamically loaded. A technique of
772     using a single long string with a table of offsets can drastically reduce
773     these. I have refactored PCRE in four places to do this. The result is
774 ph10 240 dramatic:
775 ph10 243
776 ph10 240 Originally: 290
777     After changing UCP table: 187
778 ph10 243 After changing error message table: 43
779 ph10 240 After changing table of "verbs" 36
780     After changing table of Posix names 22
781 ph10 243
782 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
783 ph10 247
784 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
785 ph10 247 unicode-properties was also set.
786    
787 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
788 ph10 231
789 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
790     checked only for CRLF.
791 ph10 233
792 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
793    
794 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
795 ph10 253
796 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
797 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
798     entirely. This removes changes made in 7 above.
799 ph10 256
800 ph10 261 17. The CMake files have been updated, and there is now more information about
801     building with CMake in the NON-UNIX-USE document.
802 ph10 257
803 ph10 261
804 ph10 228 Version 7.3 28-Aug-07
805 ph10 157 ---------------------
806    
807 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
808     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
809     brackets there is not right, since it causes compilers to look for an
810     installed pcre.h, not the version that is in the source that is being
811     compiled (which of course may be different). I have changed it back to:
812 ph10 197
813 ph10 189 #include "pcre.h"
814 ph10 197
815     I have a vague recollection that the change was concerned with compiling in
816     different directories, but in the new build system, that is taken care of
817     by the VPATH setting the Makefile.
818    
819 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
820     when the subject happened to end in the byte 0x85 (e.g. if the last
821     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
822     characters but of course it shouldn't be taken as a newline when it is part
823     of another character. The bug was that, for an unlimited repeat of . in
824     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
825     characters when looking for a newline.
826 ph10 197
827     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
828    
829     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
830     in debug output.
831    
832 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
833     long printing in the pcrecpp unittest when running under MinGW.
834 ph10 189
835 ph10 197 6. ESC_K was left out of the EBCDIC table.
836 ph10 189
837 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
838     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
839     limit also applies to "virtual nesting" when a pattern is recursive, and in
840     this case 1000 isn't so big. I have been able to remove this limit at the
841     expense of backing off one optimization in certain circumstances. Normally,
842     when pcre_exec() would call its internal match() function recursively and
843     immediately return the result unconditionally, it uses a "tail recursion"
844     feature to save stack. However, when a subpattern that can match an empty
845     string has an unlimited repetition quantifier, it no longer makes this
846     optimization. That gives it a stack frame in which to save the data for
847     checking that an empty string has been matched. Previously this was taken
848     from the 1000-entry workspace that had been reserved. So now there is no
849     explicit limit, but more stack is used.
850 ph10 189
851 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
852     syntax that is required for Windows, and which was going wrong for the
853     pcreposix and pcrecpp parts of the library. These were overlooked when this
854     problem was solved for the main library.
855 ph10 197
856 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
857     the size of patterns that contain repeated groups with explicit upper
858     limits. As the maximum quantifier is 65535, the maximum group length was
859     set at 30,000 so that the product of these two numbers did not overflow a
860     32-bit integer. However, it turns out that people want to use groups that
861     are longer than 30,000 bytes (though not repeat them that many times).
862     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
863     made it possible to implement the integer overflow checks in a much more
864     dynamic way, which I have now done. The artificial limitation on group
865     length has been removed - we now have only the limit on the total length of
866     the compiled pattern, which depends on the LINK_SIZE setting.
867 ph10 208
868     10. Fixed a bug in the documentation for get/copy named substring when
869     duplicate names are permitted. If none of the named substrings are set, the
870     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
871     empty string.
872    
873     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
874     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
875     because the ] is interpreted as the first data character and the
876     terminating ] is not found. PCRE has been made compatible with Perl in this
877     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
878     cause memory overwriting.
879    
880 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
881     string has been matched (to stop an infinite loop). It was not recognizing
882 ph10 208 a conditional subpattern that could match an empty string if that
883 ph10 206 subpattern was within another subpattern. For example, it looped when
884 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
885 ph10 206 condition was not nested. This bug has been fixed.
886 ph10 208
887 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
888     past the start of the subject in the presence of bytes with the top bit
889     set, for example "\x8aBCD".
890 ph10 211
891 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
892     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
893 ph10 200
894 ph10 211 14. Optimized (?!) to (*FAIL).
895 ph10 202
896 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
897     This restricts code points to be within the range 0 to 0x10FFFF, excluding
898     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
899     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
900     does: it's just the validity check that is more restrictive.
901 ph10 220
902     16. Inserted checks for integer overflows during escape sequence (backslash)
903     processing, and also fixed erroneous offset values for syntax errors during
904     backslash processing.
905    
906 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
907 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
908    
909 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
910     caused an overrun.
911 ph10 220
912     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
913     something other than just ASCII characters) inside a group that had an
914     unlimited repeat caused a loop at compile time (while checking to see
915     whether the group could match an empty string).
916    
917 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
918     [\P{Any}] did so. (Error in the code for printing property names.)
919 ph10 210
920 ph10 220 21. An orphan \E inside a character class could cause a crash.
921    
922     22. A repeated capturing bracket such as (A)? could cause a wild memory
923 ph10 218 reference during compilation.
924 ph10 220
925     23. There are several functions in pcre_compile() that scan along a compiled
926     expression for various reasons (e.g. to see if it's fixed length for look
927 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
928 ph10 220 present in the pattern. These operators have additional parameters compared
929     with \d, etc, and these were not being taken into account when moving along
930 ph10 218 the compiled data. Specifically:
931 ph10 220
932     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
933     length.
934    
935     (b) An item such as \pL+ within a repeated group could cause crashes or
936 ph10 218 loops.
937 ph10 220
938 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
939 ph10 220 "reference to non-existent subpattern" error.
940    
941 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
942    
943 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
944 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
945 ph10 211
946 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
947 ph10 218
948 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
949 ph10 223 character were causing crashes (broken optimization).
950 ph10 227
951 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
952 ph10 227 \p or \P) caused a compile-time loop.
953    
954 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
955     break. For example, the unstudied pattern [\r\n]A does not match the string
956     "\r\nA" because change 7.0/46 below moves the current point on by two
957     characters after failing to match at the start. However, the pattern \nA
958 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
959     the same is true. There doesn't seem any very clean way out of this, but
960     what I have chosen to do makes the common cases work: PCRE now takes note
961     of whether there can be an explicit match for \r or \n anywhere in the
962     pattern, and if so, 7.0/46 no longer applies. As part of this change,
963     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
964     pattern has explicit CR or LF references.
965 ph10 222
966 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
967 ph10 223
968 ph10 227
969 ph10 189 Version 7.2 19-Jun-07
970     ---------------------
971    
972 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
973     which is apparently normally available under Windows.
974 ph10 159
975     2. Re-jig the pcregrep tests with different newline settings in an attempt
976     to make them independent of the local environment's newline setting.
977 ph10 157
978 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
979 ph10 165
980 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
981     was not 2, because the output contained actual offsets. The recent new
982 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
983     usable with all link sizes.
984    
985 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
986     stack recursion. This gives a massive performance boost under BSD, but just
987 ph10 165 a small improvement under Linux. However, it saves one field in the frame
988 ph10 164 in all cases.
989 ph10 172
990 ph10 166 6. Added more features from the forthcoming Perl 5.10:
991 ph10 172
992 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
993     recursion call. It refers to the nth most recently opened parentheses.
994 ph10 172
995 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
996 ph10 172 to be opened parentheses.
997    
998     (c) Conditions that refer to capturing parentheses can be specified
999 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1000 ph10 172
1001 ph10 168 (d) \K resets the start of the current match so that everything before
1002 ph10 172 is not part of it.
1003    
1004 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1005 ph10 172
1006 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1007 ph10 172 reference syntax.
1008 ph10 182
1009 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1010 ph10 182 alternative starts with the same number.
1011 ph10 172
1012 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1013    
1014 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1015     PCRE_INFO_JCHANGED.
1016    
1017     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1018     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1019 ph10 170 for detecting groups that can match an empty string.
1020 ph10 159
1021 ph10 172 9. A pattern with a very large number of alternatives (more than several
1022     hundred) was running out of internal workspace during the pre-compile
1023     phase, where pcre_compile() figures out how much memory will be needed. A
1024     bit of new cunning has reduced the workspace needed for groups with
1025     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1026     workspace instead of running out of the 4096 that are available.
1027 ph10 182
1028 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1029 ph10 172
1030 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1031     The report of the bug said:
1032 ph10 182
1033 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1034     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1035 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1036 ph10 185
1037 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1038 ph10 185 it matched the wrong number of bytes.
1039 ph10 172
1040 ph10 179
1041 ph10 155 Version 7.1 24-Apr-07
1042 ph10 98 ---------------------
1043    
1044 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1045 ph10 122 that is more "standard", making use of automake and other Autotools. There
1046 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1047     on this.
1048 ph10 111
1049     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1050     for recursive directory scanning broke on some systems because the files
1051     are not scanned in any specific order and on different systems the order
1052     was different. A call to "sort" has been inserted into RunGrepTest for the
1053     approprate test as a short-term fix. In the longer term there may be an
1054 ph10 100 alternative.
1055 ph10 111
1056 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1057 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1058     people do their own conversions for various reasons). The problems
1059     concerned the use of low-level troff macros .br and .in. I have therefore
1060     removed all such uses from the man pages (some were redundant, some could
1061 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1062     HTML has been updated to handle .nf/.fi and to complain if it encounters
1063     .br or .in.
1064 ph10 111
1065 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1066 ph10 123 arranged for config.h to be included in the distribution, with the name
1067 ph10 111 config.h.generic, for the benefit of those who have to compile without
1068     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1069    
1070     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1071     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1072 ph10 127 makevp.bat for the current PCRE, using the additional files
1073 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1074 ph10 111
1075     6. A Windows user reported a minor discrepancy with test 2, which turned out
1076     to be caused by a trailing space on an input line that had got lost in his
1077 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1078 ph10 111
1079 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1080 ph10 111 that is needed.
1081    
1082 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1083     as "const" (a) because they are and (b) because it helps the PHP
1084     maintainers who have recently made a script to detect big data structures
1085 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1086     to update Builducptable as well, so it won't revert if ucptable.h is ever
1087 ph10 105 re-created.
1088 ph10 111
1089     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1090 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1091 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1092     support is not required. This saves 1.5-2K of code, which is important in
1093 ph10 107 some applications.
1094 ph10 111
1095 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1096 ph10 111 so as not to refer to the tables, even though these functions will never be
1097     called when UTF-8 support is disabled. Otherwise there are problems with a
1098     shared library.
1099    
1100 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1101    
1102     (a) It was defining its arguments as char * instead of void *.
1103    
1104 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1105     a long time ago when I wrote it, but is no longer the case.
1106    
1107 ph10 118 The emulated memove() is provided for those environments that have neither
1108 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1109 ph10 118 is clearly not the case, as these two bugs were recently reported.
1110 ph10 123
1111 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1112 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1113     pages, and it removes trailing spaces from listed files. It also creates
1114     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1115     case, it wraps all the #defines with #ifndefs. This script should be run
1116 ph10 111 before "make dist".
1117 ph10 123
1118 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1119     with Unicode property support.
1120 ph10 123
1121     (a) For a maximizing quantifier, if the two different cases of the
1122     character were of different lengths in their UTF-8 codings (there are
1123     some cases like this - I found 11), and the matching function had to
1124 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1125     were both the same length.
1126 ph10 123
1127     (b) When PCRE was configured to use the heap rather than the stack for
1128     recursion during matching, it was not correctly preserving the data for
1129     the other case of a UTF-8 character when checking ahead for a match
1130     while processing a minimizing repeat. If the check also involved
1131 ph10 115 matching a wide character, but failed, corruption could cause an
1132     erroneous result when trying to check for a repeat of the original
1133     character.
1134 ph10 123
1135 ph10 116 13. Some tidying changes to the testing mechanism:
1136 ph10 98
1137 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1138     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1139 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1140     this for UTF-8.) The configure.ac script no longer substitutes the
1141     relevant variables.
1142    
1143 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1144     with length and offset values. This means that the output is different
1145     for different internal link sizes. Test 2 is skipped for link sizes
1146     other than 2 because of this, bypassing the problem. Unfortunately,
1147     there was also a test in test 3 (the locale tests) that used /B and
1148 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1149     I have added a new /Z option to pcretest that replaces the length and
1150     offset values with spaces. This is now used to make test 3 independent
1151 ph10 122 of link size. (Test 2 will be tidied up later.)
1152 ph10 123
1153     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1154 ph10 122 segmentation fault instead of returning the appropriate error message.
1155 ph10 134
1156 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1157 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1158     This doesn't seem right; it now treats the CRLF combination as the line
1159     ending, and so does not match in that case. It's only a pattern such as ^$
1160     that would hit this one: something like ^ABC$ would have failed after \r
1161     and then tried again after \r\n.
1162    
1163 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1164 ph10 134 in an attempt to make files that differ only in their line terminators
1165     compare equal. This works on Linux.
1166 ph10 142
1167 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1168     as it exited. This is now fixed, thanks to valgrind.
1169 ph10 142
1170 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1171 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1172     was because its rules for how to advance for /g after matching an empty
1173 ph10 143 string at the end of a line did not allow for this case. They now check for
1174     it specially.
1175 ph10 150
1176     20. pcretest is supposed to handle patterns and data of any length, by
1177     extending its buffers when necessary. It was getting this wrong when the
1178 ph10 147 buffer for a data line had to be extended.
1179 ph10 150
1180 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1181 ph10 150 CRLF as a newline sequence.
1182 ph10 152
1183 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1184 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1185     I have nevertheless tidied it up.
1186 ph10 111
1187 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1188 ph10 123
1189 ph10 153 24. Added a man page for pcre-config.
1190 ph10 152
1191 ph10 153
1192 nigel 93 Version 7.0 19-Dec-06
1193     ---------------------
1194    
1195     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1196     moving to gcc 4.1.1.
1197    
1198     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1199     sys/time.h, which is documented as needed for this function. It doesn't
1200     seem to matter on Linux, but it showed up on some releases of OS X.
1201    
1202     3. It seems that there are systems where bytes whose values are greater than
1203     127 match isprint() in the "C" locale. The "C" locale should be the
1204     default when a C program starts up. In most systems, only ASCII printing
1205     characters match isprint(). This difference caused the output from pcretest
1206     to vary, making some of the tests fail. I have changed pcretest so that:
1207    
1208     (a) When it is outputting text in the compiled version of a pattern, bytes
1209     other than 32-126 are always shown as hex escapes.
1210    
1211     (b) When it is outputting text that is a matched part of a subject string,
1212     it does the same, unless a different locale has been set for the match
1213     (using the /L modifier). In this case, it uses isprint() to decide.
1214    
1215     4. Fixed a major bug that caused incorrect computation of the amount of memory
1216     required for a compiled pattern when options that changed within the
1217     pattern affected the logic of the preliminary scan that determines the
1218     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1219     that the computed length was too small. The symptoms of this bug were
1220     either the PCRE error "internal error: code overflow" from pcre_compile(),
1221     or a glibc crash with a message such as "pcretest: free(): invalid next
1222     size (fast)". Examples of patterns that provoked this bug (shown in
1223     pcretest format) are:
1224    
1225     /(?-x: )/x
1226     /(?x)(?-x: \s*#\s*)/
1227     /((?i)[\x{c0}])/8
1228     /(?i:[\x{c0}])/8
1229    
1230     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1231     is now done differently.
1232    
1233     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1234     wrapper classes; (b) implement a new function in the C++ scanner that is
1235     more efficient than the old way of doing things because it avoids levels of
1236     recursion in the regex matching; (c) add a paragraph to the documentation
1237     for the FullMatch() function.
1238    
1239     6. The escape sequence \n was being treated as whatever was defined as
1240     "newline". Not only was this contrary to the documentation, which states
1241     that \n is character 10 (hex 0A), but it also went horribly wrong when
1242     "newline" was defined as CRLF. This has been fixed.
1243    
1244     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1245     was being set to -1 for the "end of line" case (supposedly a value that no
1246     character can have). Though this value is never used (the check for end of
1247     line is "zero bytes in current character"), it caused compiler complaints.
1248     I've changed it to 0xffffffff.
1249    
1250     8. In pcre_version.c, the version string was being built by a sequence of
1251     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1252     string (as it is for production releases) called a macro with an empty
1253     argument. The C standard says the result of this is undefined. The gcc
1254     compiler treats it as an empty string (which was what was wanted) but it is
1255     reported that Visual C gives an error. The source has been hacked around to
1256     avoid this problem.
1257    
1258     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1259     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1260     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1261     of them did).
1262    
1263     10. Originally, pcretest opened its input and output without "b"; then I was
1264     told that "b" was needed in some environments, so it was added for release
1265     5.0 to both the input and output. (It makes no difference on Unix-like
1266     systems.) Later I was told that it is wrong for the input on Windows. I've
1267     now abstracted the modes into two macros, to make it easier to fiddle with
1268     them, and removed "b" from the input mode under Windows.
1269    
1270     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1271    
1272     12. Added -help and --help to pcretest as an official way of being reminded
1273     of the options.
1274    
1275     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1276     and pcrecpp.cc because they annoy compilers at high warning levels.
1277    
1278     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1279    
1280     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1281     scripts are not C programs :-) and which was not noticed because it works
1282     on Linux.
1283    
1284     16. pcretest is supposed to handle any length of pattern and data line (as one
1285     line or as a continued sequence of lines) by extending its input buffer if
1286     necessary. This feature was broken for very long pattern lines, leading to
1287     a string of junk being passed to pcre_compile() if the pattern was longer
1288     than about 50K.
1289    
1290     17. I have done a major re-factoring of the way pcre_compile() computes the
1291     amount of memory needed for a compiled pattern. Previously, there was code
1292     that made a preliminary scan of the pattern in order to do this. That was
1293     OK when PCRE was new, but as the facilities have expanded, it has become
1294     harder and harder to keep it in step with the real compile phase, and there
1295     have been a number of bugs (see for example, 4 above). I have now found a
1296     cunning way of running the real compile function in a "fake" mode that
1297     enables it to compute how much memory it would need, while actually only
1298     ever using a few hundred bytes of working memory and without too many
1299     tests of the mode. This should make future maintenance and development
1300     easier. A side effect of this work is that the limit of 200 on the nesting
1301     depth of parentheses has been removed (though this was never a serious
1302     limitation, I suspect). However, there is a downside: pcre_compile() now
1303     runs more slowly than before (30% or more, depending on the pattern). I
1304     hope this isn't a big issue. There is no effect on runtime performance.
1305    
1306     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1307     newline (only possible for the last line of a file) and it was a
1308     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1309    
1310     19. Added additional timing features to pcretest. (1) The -tm option now times
1311     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1312     separate command line item, by a number that specifies the number of
1313     repeats to use when timing. The default is 50000; this gives better
1314     precision, but takes uncomfortably long for very large patterns.
1315    
1316     20. Extended pcre_study() to be more clever in cases where a branch of a
1317     subpattern has no definite first character. For example, (a*|b*)[cd] would
1318     previously give no result from pcre_study(). Now it recognizes that the
1319     first character must be a, b, c, or d.
1320    
1321     21. There was an incorrect error "recursive call could loop indefinitely" if
1322     a subpattern (or the entire pattern) that was being tested for matching an
1323     empty string contained only one non-empty item after a nested subpattern.
1324     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1325     incorrectly, because the \d was being skipped in the check.
1326    
1327     22. The pcretest program now has a new pattern option /B and a command line
1328     option -b, which is equivalent to adding /B to every pattern. This causes
1329     it to show the compiled bytecode, without the additional information that
1330     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1331     is the same as /B/I).
1332    
1333     23. A new optimization is now able automatically to treat some sequences such
1334     as a*b as a*+b. More specifically, if something simple (such as a character
1335     or a simple class like \d) has an unlimited quantifier, and is followed by
1336     something that cannot possibly match the quantified thing, the quantifier
1337     is automatically "possessified".
1338    
1339     24. A recursive reference to a subpattern whose number was greater than 39
1340     went wrong under certain circumstances in UTF-8 mode. This bug could also
1341     have affected the operation of pcre_study().
1342    
1343     25. Realized that a little bit of performance could be had by replacing
1344     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1345    
1346     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1347    
1348     27. Possessive quantifiers such as a++ were previously implemented by turning
1349     them into atomic groups such as ($>a+). Now they have their own opcodes,
1350     which improves performance. This includes the automatically created ones
1351     from 23 above.
1352    
1353     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1354     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1355     the first matched character to be a colon. This applied both to named and
1356     numbered groups.
1357    
1358     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1359    
1360     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1361     building PCRE on Windows easier, so I have included it in the distribution.
1362    
1363     31. There is now a check in pcretest against a ridiculously large number being
1364     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1365     loop, the loop is abandoned.
1366    
1367     32. Forward references to subpatterns in conditions such as (?(2)...) where
1368     subpattern 2 is defined later cause pcre_compile() to search forwards in
1369     the pattern for the relevant set of parentheses. This search went wrong
1370     when there were unescaped parentheses in a character class, parentheses
1371     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1372    
1373     33. "Subroutine" calls and backreferences were previously restricted to
1374     referencing subpatterns earlier in the regex. This restriction has now
1375     been removed.
1376    
1377     34. Added a number of extra features that are going to be in Perl 5.10. On the
1378     whole, these are just syntactic alternatives for features that PCRE had
1379     previously implemented using the Python syntax or my own invention. The
1380     other formats are all retained for compatibility.
1381    
1382     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1383     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1384     also .NET compatible.
1385    
1386     (b) A recursion or subroutine call to a named group can now be defined as
1387     (?&name) as well as (?P>name).
1388    
1389     (c) A backreference to a named group can now be defined as \k<name> or
1390     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1391     5.10, are also .NET compatible.
1392    
1393     (d) A conditional reference to a named group can now use the syntax
1394     (?(<name>) or (?('name') as well as (?(name).
1395    
1396     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1397     groups (named and numbered) that are never evaluated inline, but can be
1398     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1399     is always false. There may be only one alternative in such a group.
1400    
1401     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1402     as the simple (?(R). The condition is true only if the most recent
1403     recursion is that of the given number or name. It does not search out
1404     through the entire recursion stack.
1405    
1406     (g) The escape \gN or \g{N} has been added, where N is a positive or
1407     negative number, specifying an absolute or relative reference.
1408    
1409     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1410     some "unreachable code" warnings.
1411    
1412     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1413     things, this adds five new scripts.
1414    
1415     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1416     There were also incompatibilities regarding the handling of \Q..\E inside
1417     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1418     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1419    
1420     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1421     matches an empty string, and forcibly breaks the loop. There were bugs in
1422     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1423     against aaaa the result was just "a" rather than "aaaa", for example. Two
1424     separate and independent bugs (that affected different cases) have been
1425     fixed.
1426    
1427     39. Refactored the code to abolish the use of different opcodes for small
1428     capturing bracket numbers. This is a tidy that I avoided doing when I
1429     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1430     The new approach is not only tidier, it makes it possible to reduce the
1431     memory needed to fix the previous bug (38).
1432    
1433     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1434     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1435     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1436     mode.
1437    
1438     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1439     report.
1440    
1441     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1442     copy construction and assignment in the C++ wrapper.
1443    
1444     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1445     couple of bugs that could have given wrong results in the "--newline=crlf"
1446     case.
1447    
1448     44. Added a number of casts and did some reorganization of signed/unsigned int
1449     variables following suggestions from Dair Grant. Also renamed the variable
1450     "this" as "item" because it is a C++ keyword.
1451    
1452     45. Arranged for dftables to add
1453    
1454     #include "pcre_internal.h"
1455    
1456     to pcre_chartables.c because without it, gcc 4.x may remove the array
1457     definition from the final binary if PCRE is built into a static library and
1458     dead code stripping is activated.
1459    
1460     46. For an unanchored pattern, if a match attempt fails at the start of a
1461     newline sequence, and the newline setting is CRLF or ANY, and the next two
1462     characters are CRLF, advance by two characters instead of one.
1463    
1464    
1465 nigel 91 Version 6.7 04-Jul-06
1466     ---------------------
1467    
1468     1. In order to handle tests when input lines are enormously long, pcretest has
1469     been re-factored so that it automatically extends its buffers when
1470     necessary. The code is crude, but this _is_ just a test program. The
1471     default size has been increased from 32K to 50K.
1472    
1473     2. The code in pcre_study() was using the value of the re argument before
1474     testing it for NULL. (Of course, in any sensible call of the function, it
1475     won't be NULL.)
1476    
1477     3. The memmove() emulation function in pcre_internal.h, which is used on
1478     systems that lack both memmove() and bcopy() - that is, hardly ever -
1479     was missing a "static" storage class specifier.
1480    
1481     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1482     containing an extended class (one that cannot be represented by a bitmap
1483     because it contains high-valued characters or Unicode property items, e.g.
1484     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1485     pattern, but PCRE should not loop if you do not (it no longer does).
1486     [Detail: two cases were found: (a) a repeated subpattern containing an
1487     extended class; (b) a recursive reference to a subpattern that followed a
1488     previous extended class. It wasn't skipping over the extended class
1489     correctly when UTF-8 mode was not set.]
1490    
1491     5. A negated single-character class was not being recognized as fixed-length
1492     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1493     compile error "lookbehind assertion is not fixed length".
1494    
1495     6. The RunPerlTest auxiliary script was showing an unexpected difference
1496     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1497     write a Perl script that can interpret lines of an input file either as
1498     byte characters or as UTF-8, which is what "perltest" was being required to
1499     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1500     can't do is switch easily at run time between having the "use utf8;" pragma
1501     or not. In the end, I fudged it by using the RunPerlTest script to insert
1502     "use utf8;" explicitly for the UTF-8 tests.
1503    
1504     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1505     the end of the subject string, contrary to the documentation and to what
1506     Perl does. This was true of both matching functions. Now it matches only at
1507     the start of the subject and immediately after *internal* newlines.
1508    
1509     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1510     a pointer to an int instead of a pointer to an unsigned long int. This
1511     caused problems on 64-bit systems.
1512    
1513     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1514     instance of the 'standard' template library not being so standard".
1515    
1516     10. There was no check on the number of named subpatterns nor the maximum
1517     length of a subpattern name. The product of these values is used to compute
1518     the size of the memory block for a compiled pattern. By supplying a very
1519     long subpattern name and a large number of named subpatterns, the size
1520     computation could be caused to overflow. This is now prevented by limiting
1521     the length of names to 32 characters, and the number of named subpatterns
1522     to 10,000.
1523    
1524     11. Subpatterns that are repeated with specific counts have to be replicated in
1525     the compiled pattern. The size of memory for this was computed from the
1526     length of the subpattern and the repeat count. The latter is limited to
1527     65535, but there was no limit on the former, meaning that integer overflow
1528     could in principle occur. The compiled length of a repeated subpattern is
1529     now limited to 30,000 bytes in order to prevent this.
1530    
1531     12. Added the optional facility to have named substrings with the same name.
1532    
1533     13. Added the ability to use a named substring as a condition, using the
1534     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1535     are numbers (not recommended). Forward references are permitted.
1536    
1537     14. Added forward references in named backreferences (if you see what I mean).
1538    
1539     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1540     pattern could run off the end of the subject. For example, the pattern
1541     "(?s)(.{1,5})"8 did this with the subject "ab".
1542    
1543     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1544     PCRE_CASELESS was set when matching characters that were quantified with ?
1545     or *.
1546    
1547     17. A character class other than a single negated character that had a minimum
1548     but no maximum quantifier - for example [ab]{6,} - was not handled
1549     correctly by pce_dfa_exec(). It would match only one character.
1550    
1551     18. A valid (though odd) pattern that looked like a POSIX character
1552     class but used an invalid character after [ (for example [[,abc,]]) caused
1553     pcre_compile() to give the error "Failed: internal error: code overflow" or
1554     in some cases to crash with a glibc free() error. This could even happen if
1555     the pattern terminated after [[ but there just happened to be a sequence of
1556     letters, a binary zero, and a closing ] in the memory that followed.
1557    
1558     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1559     over the years. Originally (before any Unicode support), just the bottom 8
1560     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1561     output from "man perlunicode" includes this:
1562    
1563     The regular expression compiler produces polymorphic opcodes. That
1564     is, the pattern adapts to the data and automatically switches to
1565     the Unicode character scheme when presented with Unicode data--or
1566     instead uses a traditional byte scheme when presented with byte
1567     data.
1568    
1569     Sadly, a wide octal escape does not cause a switch, and in a string with
1570     no other multibyte characters, these octal escapes are treated as before.
1571     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1572     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1573     Unicode string.
1574    
1575     I have not perpetrated such confusion in PCRE. Up till now, it took just
1576     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1577     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1578     translate to the appropriate multibyte character.
1579    
1580     29. Applied some refactoring to reduce the number of warnings from Microsoft
1581     and Borland compilers. This has included removing the fudge introduced
1582     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1583     a warning about an unused variable.
1584    
1585     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1586     characters since release 4.0, because Perl (from release 5.004) does not.
1587     [Or at least, is documented not to: some releases seem to be in conflict
1588     with the documentation.] However, when a pattern was studied with
1589     pcre_study() and all its branches started with \s, PCRE still included VT
1590     as a possible starting character. Of course, this did no harm; it just
1591     caused an unnecessary match attempt.
1592    
1593     22. Removed a now-redundant internal flag bit that recorded the fact that case
1594     dependency changed within the pattern. This was once needed for "required
1595     byte" processing, but is no longer used. This recovers a now-scarce options
1596     bit. Also moved the least significant internal flag bit to the most-
1597     significant bit of the word, which was not previously used (hangover from
1598     the days when it was an int rather than a uint) to free up another bit for
1599     the future.
1600    
1601     23. Added support for CRLF line endings as well as CR and LF. As well as the
1602     default being selectable at build time, it can now be changed at runtime
1603     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1604     specify that it is scanning data with non-default line endings.
1605    
1606     24. Changed the definition of CXXLINK to make it agree with the definition of
1607     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1608    
1609     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1610     recursions. This makes a big different to stack usage for some patterns.
1611    
1612     26. If a subpattern containing a named recursion or subroutine reference such
1613     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1614     the space required for the compiled pattern went wrong and gave too small a
1615     value. Depending on the environment, this could lead to "Failed: internal
1616     error: code overflow at offset 49" or "glibc detected double free or
1617     corruption" errors.
1618    
1619     27. Applied patches from Google (a) to support the new newline modes and (b) to
1620     advance over multibyte UTF-8 characters in GlobalReplace.
1621    
1622     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1623     difference for some implementation of PCRE in some Windows version.
1624    
1625     29. Added some extra testing facilities to pcretest:
1626    
1627     \q<number> in a data line sets the "match limit" value
1628     \Q<number> in a data line sets the "match recursion limt" value
1629     -S <number> sets the stack size, where <number> is in megabytes
1630    
1631     The -S option isn't available for Windows.
1632    
1633    
1634 nigel 89 Version 6.6 06-Feb-06
1635     ---------------------
1636    
1637     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1638     in pcreposix.h. I have copied the definition from pcre.h.
1639    
1640     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1641     because pcre.h is no longer a built file.
1642    
1643     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1644     not normally included in the compiled code.
1645    
1646    
1647 nigel 87 Version 6.5 01-Feb-06
1648     ---------------------
1649    
1650     1. When using the partial match feature with pcre_dfa_exec(), it was not
1651     anchoring the second and subsequent partial matches at the new starting
1652     point. This could lead to incorrect results. For example, with the pattern
1653     /1234/, partially matching against "123" and then "a4" gave a match.
1654    
1655     2. Changes to pcregrep:
1656    
1657     (a) All non-match returns from pcre_exec() were being treated as failures
1658     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1659     error message is output. Some extra information is given for the
1660     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1661     probably the only errors that are likely to be caused by users (by
1662     specifying a regex that has nested indefinite repeats, for instance).
1663     If there are more than 20 of these errors, pcregrep is abandoned.
1664    
1665     (b) A binary zero was treated as data while matching, but terminated the
1666     output line if it was written out. This has been fixed: binary zeroes
1667     are now no different to any other data bytes.
1668    
1669     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1670     used to set a locale for matching. The --locale=xxxx long option has
1671     been added (no short equivalent) to specify a locale explicitly on the
1672     pcregrep command, overriding the environment variables.
1673    
1674     (d) When -B was used with -n, some line numbers in the output were one less
1675     than they should have been.
1676    
1677     (e) Added the -o (--only-matching) option.
1678    
1679     (f) If -A or -C was used with -c (count only), some lines of context were
1680     accidentally printed for the final match.
1681    
1682     (g) Added the -H (--with-filename) option.
1683    
1684     (h) The combination of options -rh failed to suppress file names for files
1685     that were found from directory arguments.
1686    
1687     (i) Added the -D (--devices) and -d (--directories) options.
1688    
1689     (j) Added the -F (--fixed-strings) option.
1690    
1691     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1692    
1693     (l) Added the --colo(u)r option.
1694    
1695     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1696     is not present by default.
1697    
1698     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1699     items such as (?R) or (?1), when the recursion could match a number of
1700     alternatives. If it matched one of the alternatives, but subsequently,
1701     outside the recursion, there was a failure, the code tried to back up into
1702     the recursion. However, because of the way PCRE is implemented, this is not
1703     possible, and the result was an incorrect result from the match.
1704    
1705     In order to prevent this happening, the specification of recursion has
1706     been changed so that all such subpatterns are automatically treated as
1707     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1708    
1709     4. I had overlooked the fact that, in some locales, there are characters for
1710     which isalpha() is true but neither isupper() nor islower() are true. In
1711     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1712     and ordfeminine) are like this. This affected the treatment of \w and \W
1713     when they appeared in character classes, but not when they appeared outside
1714     a character class. The bit map for "word" characters is now created
1715     separately from the results of isalnum() instead of just taking it from the
1716     upper, lower, and digit maps. (Plus the underscore character, of course.)
1717    
1718     5. The above bug also affected the handling of POSIX character classes such as
1719     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1720     permanent tables. Instead, the bit maps for such a class were previously
1721     created as the appropriate unions of the upper, lower, and digit bitmaps.
1722     Now they are created by subtraction from the [[:word:]] class, which has
1723     its own bitmap.
1724    
1725     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1726     It is created by subtracting the vertical space characters (\x09, \x0a,
1727     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1728     subtraction was done in the overall bitmap for a character class, meaning
1729     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1730     be recognized. This bug has been fixed.
1731    
1732     7. Patches from the folks at Google:
1733    
1734     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1735     real life, but is still worth protecting against".
1736    
1737     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1738     regular expressions".
1739    
1740     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1741     have it.
1742    
1743     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1744     "configure" and the latter not, in order to fix a problem somebody had
1745     with compiling the Arg class on HP-UX.
1746    
1747     (e) Improve the error-handling of the C++ wrapper a little bit.
1748    
1749     (f) New tests for checking recursion limiting.
1750    
1751     8. The pcre_memmove() function, which is used only if the environment does not
1752     have a standard memmove() function (and is therefore rarely compiled),
1753     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1754     returning a result (though PCRE never actually uses the result).
1755    
1756     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1757     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1758     returned instead of calling malloc() with an overflowing number that would
1759     most likely cause subsequent chaos.
1760    
1761     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1762    
1763     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1764     with this option is matched, the nmatch and pmatch options of regexec() are
1765     ignored.
1766    
1767     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1768     provided in case anyone wants to the the POSIX interface with UTF-8
1769     strings.
1770    
1771     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1772     C++ linking (needed for some HP-UX environments).
1773    
1774     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1775     (unused parameter) and in the pcre_printint() function (omitted "default"
1776     switch label when the default is to do nothing).
1777    
1778     15. Added some code to make it possible, when PCRE is compiled as a C++
1779     library, to replace subject pointers for pcre_exec() with a smart pointer
1780     class, thus making it possible to process discontinuous strings.
1781    
1782     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1783     much the same function. They were added by different people who were trying
1784     to make PCRE easy to compile on non-Unix systems. It has been suggested
1785     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1786     for compiling on Windows systems. I have therefore replaced it with
1787     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1788     defaults to "extern" for C or "extern C" for C++, which works fine on
1789     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1790     SCOPE with something explicit in config.h. In addition:
1791    
1792     (a) pcreposix.h still had just "extern" instead of either of these macros;
1793     I have replaced it with PCRE_DATA_SCOPE.
1794    
1795     (b) Functions such as _pcre_xclass(), which are internal to the library,
1796     but external in the C sense, all had PCRE_EXPORT in their definitions.
1797     This is apparently wrong for the Windows case, so I have removed it.
1798     (It makes no difference on Unix-like systems.)
1799    
1800     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1801     of recursive calls to match(). This is different to MATCH_LIMIT because
1802     that limits the total number of calls to match(), not all of which increase
1803     the depth of recursion. Limiting the recursion depth limits the amount of
1804     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1805     when PCRE is compiled, and changed at run time. A patch from Google adds
1806     this functionality to the C++ interface.
1807    
1808     18. Changes to the handling of Unicode character properties:
1809    
1810     (a) Updated the table to Unicode 4.1.0.
1811    
1812     (b) Recognize characters that are not in the table as "Cn" (undefined).
1813    
1814     (c) I revised the way the table is implemented to a much improved format
1815     which includes recognition of ranges. It now supports the ranges that
1816     are defined in UnicodeData.txt, and it also amalgamates other
1817     characters into ranges. This has reduced the number of entries in the
1818     table from around 16,000 to around 3,000, thus reducing its size
1819     considerably. I realized I did not need to use a tree structure after
1820     all - a binary chop search is just as efficient. Having reduced the
1821     number of entries, I extended their size from 6 bytes to 8 bytes to
1822     allow for more data.
1823    
1824     (d) Added support for Unicode script names via properties such as \p{Han}.
1825    
1826     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1827     matching that character.
1828    
1829     20. When matching a repeated Unicode property with a minimum greater than zero,
1830     (for example \pL{2,}), PCRE could look past the end of the subject if it
1831     reached it while seeking the minimum number of characters. This could
1832     happen only if some of the characters were more than one byte long, because
1833     there is a check for at least the minimum number of bytes.
1834    
1835     21. Refactored the implementation of \p and \P so as to be more general, to
1836     allow for more different types of property in future. This has changed the
1837     compiled form incompatibly. Anybody with saved compiled patterns that use
1838     \p or \P will have to recompile them.
1839    
1840     22. Added "Any" and "L&" to the supported property types.
1841    
1842     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1843     but give a compile time error if the value is greater than 0xff.
1844    
1845     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1846     accidentally not being installed or uninstalled.
1847    
1848     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1849     made were to insert the current release number. This seemed silly, because
1850     it made things harder for people building PCRE on systems that don't run
1851     "configure". I have turned pcre.h into a distributed file, no longer built
1852     by "configure", with the version identification directly included. There is
1853     no longer a pcre.h.in file.
1854    
1855     However, this change necessitated a change to the pcre-config script as
1856     well. It is built from pcre-config.in, and one of the substitutions was the
1857     release number. I have updated configure.ac so that ./configure now finds
1858     the release number by grepping pcre.h.
1859    
1860     26. Added the ability to run the tests under valgrind.
1861    
1862    
1863 nigel 85 Version 6.4 05-Sep-05
1864     ---------------------
1865    
1866     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1867     "--" to be printed when multiple files were scanned, even when none of the
1868     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1869     consider it to be a bug, and have restored the previous behaviour.
1870    
1871     2. A couple of code tidies to get rid of compiler warnings.
1872    
1873     3. The pcretest program used to cheat by referring to symbols in the library
1874     whose names begin with _pcre_. These are internal symbols that are not
1875     really supposed to be visible externally, and in some environments it is
1876     possible to suppress them. The cheating is now confined to including
1877     certain files from the library's source, which is a bit cleaner.
1878    
1879     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1880     file's purpose clearer.
1881    
1882     5. Reorganized pcre_ucp_findchar().
1883    
1884    
1885 nigel 83 Version 6.3 15-Aug-05
1886     ---------------------
1887    
1888     1. The file libpcre.pc.in did not have general read permission in the tarball.
1889    
1890     2. There were some problems when building without C++ support:
1891    
1892     (a) If C++ support was not built, "make install" and "make test" still
1893     tried to test it.
1894    
1895     (b) There were problems when the value of CXX was explicitly set. Some
1896     changes have been made to try to fix these, and ...
1897    
1898     (c) --disable-cpp can now be used to explicitly disable C++ support.
1899    
1900     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1901     backslash in a target when C++ was disabled. This confuses some
1902     versions of "make", apparently. Using an intermediate variable solves
1903     this. (Same for CPP_LOBJ.)
1904    
1905     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1906     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1907     necessary on certain architectures.
1908    
1909     4. Added a setting of -export-symbols-regex to the link command to remove
1910     those symbols that are exported in the C sense, but actually are local
1911     within the library, and not documented. Their names all begin with
1912     "_pcre_". This is not a perfect job, because (a) we have to except some
1913     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1914     available (and never for static libraries). I have made a note to try to
1915     find a way round (a) in the future.
1916    
1917    
1918 nigel 81 Version 6.2 01-Aug-05
1919     ---------------------
1920    
1921     1. There was no test for integer overflow of quantifier values. A construction
1922     such as {1111111111111111} would give undefined results. What is worse, if
1923     a minimum quantifier for a parenthesized subpattern overflowed and became
1924     negative, the calculation of the memory size went wrong. This could have
1925     led to memory overwriting.
1926    
1927     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1928    
1929     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1930     operating environments where this matters.
1931    
1932     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1933     PCRE options from within the C++ wrapper.
1934    
1935     5. Named capturing subpatterns were not being correctly counted when a pattern
1936     was compiled. This caused two problems: (a) If there were more than 100
1937     such subpatterns, the calculation of the memory needed for the whole
1938     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1939     back references of the form \12, where the number was greater than 9, were
1940     not recognized as back references, even though there were sufficient
1941     previous subpatterns.
1942    
1943     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1944     versions of gcc, e.g. 2.95.4.
1945    
1946    
1947 nigel 79 Version 6.1 21-Jun-05
1948     ---------------------
1949    
1950     1. There was one reference to the variable "posix" in pcretest.c that was not
1951     surrounded by "#if !defined NOPOSIX".
1952    
1953     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1954     the cross-check on the old pcre_info() function, for the benefit of the
1955     cut-down version of PCRE that is currently imported into Exim.
1956    
1957     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1958     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1959     patterns that start (?i) but I don't think that matters. The use of (?i) is
1960     just an example; this all applies to the other options as well.
1961    
1962     4. Since libtool seems to echo the compile commands it is issuing, the output
1963     from "make" can be reduced a bit by putting "@" in front of each libtool
1964     compile command.
1965    
1966     5. Patch from the folks at Google for configure.in to be a bit more thorough
1967     in checking for a suitable C++ installation before trying to compile the
1968     C++ stuff. This should fix a reported problem when a compiler was present,
1969     but no suitable headers.
1970    
1971     6. The man pages all had just "PCRE" as their title. I have changed them to
1972     be the relevant file name. I have also arranged that these names are
1973     retained in the file doc/pcre.txt, which is a concatenation in text format
1974     of all the man pages except the little individual ones for each function.
1975    
1976     7. The NON-UNIX-USE file had not been updated for the different set of source
1977     files that come with release 6. I also added a few comments about the C++
1978     wrapper.
1979    
1980    
1981 nigel 77 Version 6.0 07-Jun-05
1982     ---------------------
1983    
1984     1. Some minor internal re-organization to help with my DFA experiments.
1985    
1986     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1987     didn't matter for the library itself when fully configured, but did matter
1988     when compiling without UCP support, or within Exim, where the ucp files are
1989     not imported.
1990    
1991     3. Refactoring of the library code to split up the various functions into
1992     different source modules. The addition of the new DFA matching code (see
1993     below) to a single monolithic source would have made it really too
1994     unwieldy, quite apart from causing all the code to be include in a
1995     statically linked application, when only some functions are used. This is
1996     relevant even without the DFA addition now that patterns can be compiled in
1997     one application and matched in another.
1998    
1999     The downside of splitting up is that there have to be some external
2000     functions and data tables that are used internally in different modules of
2001     the library but which are not part of the API. These have all had their
2002     names changed to start with "_pcre_" so that they are unlikely to clash
2003     with other external names.
2004    
2005     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2006     a different (DFA) algorithm. Although it is slower than the original
2007     function, it does have some advantages for certain types of matching
2008     problem.
2009    
2010     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2011     including restarting after a partial match.
2012    
2013     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2014     defined when compiling for Windows was sent to me. I have put it into the
2015     code, though I have no means of testing or verifying it.
2016    
2017     7. Added the pcre_refcount() auxiliary function.
2018    
2019     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2020     match before or at the first newline in the subject string. In pcretest,
2021     the /f option on a pattern can be used to set this.
2022    
2023     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2024     would behave wrongly. This has been present in PCRE since release 4.0.
2025    
2026     10. A number of changes to the pcregrep command:
2027    
2028     (a) Refactored how -x works; insert ^(...)$ instead of setting
2029     PCRE_ANCHORED and checking the length, in preparation for adding
2030     something similar for -w.
2031    
2032     (b) Added the -w (match as a word) option.
2033    
2034     (c) Refactored the way lines are read and buffered so as to have more
2035     than one at a time available.
2036    
2037     (d) Implemented a pcregrep test script.
2038    
2039     (e) Added the -M (multiline match) option. This allows patterns to match
2040     over several lines of the subject. The buffering ensures that at least
2041     8K, or the rest of the document (whichever is the shorter) is available
2042     for matching (and similarly the previous 8K for lookbehind assertions).
2043    
2044     (f) Changed the --help output so that it now says
2045    
2046     -w, --word-regex(p)
2047    
2048     instead of two lines, one with "regex" and the other with "regexp"
2049     because that confused at least one person since the short forms are the
2050     same. (This required a bit of code, as the output is generated
2051     automatically from a table. It wasn't just a text change.)
2052    
2053     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2054     option but starts with a hyphen. Could be a pattern or a path name
2055     starting with a hyphen, for instance.
2056    
2057     (h) "-" can be given as a file name to represent stdin.
2058    
2059     (i) When file names are being printed, "(standard input)" is used for
2060     the standard input, for compatibility with GNU grep. Previously
2061     "<stdin>" was used.
2062    
2063     (j) The option --label=xxx can be used to supply a name to be used for
2064     stdin when file names are being printed. There is no short form.
2065    
2066     (k) Re-factored the options decoding logic because we are going to add
2067     two more options that take data. Such options can now be given in four
2068     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2069    
2070     (l) Added the -A, -B, and -C options for requesting that lines of context
2071     around matches be printed.
2072    
2073     (m) Added the -L option to print the names of files that do not contain
2074     any matching lines, that is, the complement of -l.
2075    
2076     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2077     continue to scan other files.
2078    
2079     (o) The -s option was incorrectly implemented. For compatibility with other
2080     greps, it now suppresses the error message for a non-existent or non-
2081     accessible file (but not the return code). There is a new option called
2082     -q that suppresses the output of matching lines, which was what -s was
2083     previously doing.
2084    
2085     (p) Added --include and --exclude options to specify files for inclusion
2086     and exclusion when recursing.
2087    
2088     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2089     Hopefully, it now does.
2090    
2091     12. Missing cast in pcre_study().
2092    
2093     13. Added an "uninstall" target to the makefile.
2094    
2095     14. Replaced "extern" in the function prototypes in Makefile.in with
2096     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2097     world, but is set differently for Windows.
2098    
2099     15. Added a second compiling function called pcre_compile2(). The only
2100     difference is that it has an extra argument, which is a pointer to an
2101     integer error code. When there is a compile-time failure, this is set
2102     non-zero, in addition to the error test pointer being set to point to an
2103     error message. The new argument may be NULL if no error number is required
2104     (but then you may as well call pcre_compile(), which is now just a
2105     wrapper). This facility is provided because some applications need a
2106     numeric error indication, but it has also enabled me to tidy up the way
2107     compile-time errors are handled in the POSIX wrapper.
2108    
2109     16. Added VPATH=.libs to the makefile; this should help when building with one
2110     prefix path and installing with another. (Or so I'm told by someone who
2111     knows more about this stuff than I do.)
2112    
2113     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2114     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2115     match everything, including newlines. This is not POSIX-compatible, but
2116     somebody wanted the feature. From pcretest it can be activated by using
2117     both the P and the s flags.
2118    
2119     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2120    
2121     19. libpcre.pc was being incorrectly installed as executable.
2122    
2123     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2124     it now also looks for '\r' so that it will work unmodified on Windows.
2125    
2126     21. Added Google's contributed C++ wrapper to the distribution.
2127    
2128     22. Added some untidy missing memory free() calls in pcretest, to keep
2129     Electric Fence happy when testing.
2130    
2131    
2132    
2133 nigel 75 Version 5.0 13-Sep-04
2134     ---------------------
2135    
2136     1. Internal change: literal characters are no longer packed up into items
2137     containing multiple characters in a single byte-string. Each character
2138     is now matched using a separate opcode. However, there may be more than one
2139     byte in the character in UTF-8 mode.
2140    
2141     2. The pcre_callout_block structure has two new fields: pattern_position and
2142     next_item_length. These contain the offset in the pattern to the next match
2143     item, and its length, respectively.
2144    
2145     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2146     insertion of callouts before each pattern item. Added the /C option to
2147     pcretest to make use of this.
2148    
2149     4. On the advice of a Windows user, the lines
2150    
2151     #if defined(_WIN32) || defined(WIN32)
2152     _setmode( _fileno( stdout ), 0x8000 );
2153     #endif /* defined(_WIN32) || defined(WIN32) */
2154    
2155     have been added to the source of pcretest. This apparently does useful
2156     magic in relation to line terminators.
2157    
2158     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2159     for the benefit of those environments where the "b" makes a difference.
2160    
2161     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2162     to know about it. I have put a hack into configure.in that adds in code
2163     to set GCC=yes if CC=icc. This seems to end up at a point in the
2164     generated configure script that is early enough to affect the setting of
2165     compiler options, which is what is needed, but I have no means of testing
2166     whether it really works. (The user who reported this had patched the
2167     generated configure script, which of course I cannot do.)
2168    
2169     LATER: After change 22 below (new libtool files), the configure script
2170     seems to know about icc (and also ecc). Therefore, I have commented out
2171     this hack in configure.in.
2172    
2173     7. Added support for pkg-config (2 patches were sent in).
2174    
2175     8. Negated POSIX character classes that used a combination of internal tables
2176     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2177     [[:^ascii]]. Typically, they would match almost any characters. The other
2178     POSIX classes were not broken in this way.
2179    
2180     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2181     to find the match, as PCRE was deluded into thinking that the match had to
2182     start at the start point or following a newline. The same bug applied to
2183     patterns with negative forward assertions or any backward assertions
2184     preceding ".*" at the start, unless the pattern required a fixed first
2185     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2186    
2187     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2188     starting at the last subject character, bytes beyond the end of the subject
2189     string were read.
2190    
2191     11. Renamed the variable "class" as "classbits" to make life easier for C++
2192     users. (Previously there was a macro definition, but it apparently wasn't
2193     enough.)
2194    
2195     12. Added the new field "tables" to the extra data so that tables can be passed
2196     in at exec time, or the internal tables can be re-selected. This allows
2197     a compiled regex to be saved and re-used at a later time by a different
2198     program that might have everything at different addresses.
2199    
2200     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2201     -R library as well as a -L library.
2202    
2203     14. The debugging options of pcretest (-d on the command line or D on a
2204     pattern) showed incorrect output for anything following an extended class
2205     that contained multibyte characters and which was followed by a quantifier.
2206    
2207     15. Added optional support for general category Unicode character properties
2208     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2209     support. It adds about 90K to the size of the library. The meanings of the
2210     inbuilt class escapes such as \d and \s have NOT been changed.
2211    
2212     16. Updated pcredemo.c to include calls to free() to release the memory for the
2213     compiled pattern.
2214    
2215     17. The generated file chartables.c was being created in the source directory
2216     instead of in the building directory. This caused the build to fail if the
2217     source directory was different from the building directory, and was
2218     read-only.
2219    
2220     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2221     file. No doubt somebody will tell me if they don't make sense... Also added
2222     Dan Mooney's comments about building on OpenVMS.
2223    
2224     19. Added support for partial matching via the PCRE_PARTIAL option for
2225     pcre_exec() and the \P data escape in pcretest.
2226    
2227     20. Extended pcretest with 3 new pattern features:
2228    
2229     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2230     write the compiled pattern to the file whose name is "rest-of-line".
2231     This is a straight binary dump of the data, with the saved pointer to
2232     the character tables forced to be NULL. The study data, if any, is
2233     written too. After writing, pcretest reads a new pattern.
2234    
2235     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2236     compiled pattern from the given file. There must not be any
2237     occurrences of "<" in the file name (pretty unlikely); if there are,
2238     pcretest will instead treat the initial "<" as a pattern delimiter.
2239     After reading in the pattern, pcretest goes on to read data lines as
2240     usual.
2241    
2242     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2243     and 16-bit fields in a compiled pattern, to simulate a pattern that
2244     was compiled on a host of opposite endianness.
2245    
2246     21. The pcre-exec() function can now cope with patterns that were compiled on
2247     hosts of opposite endianness, with this restriction:
2248    
2249     As for any compiled expression that is saved and used later, the tables
2250     pointer field cannot be preserved; the extra_data field in the arguments
2251     to pcre_exec() should be used to pass in a tables address if a value
2252     other than the default internal tables were used at compile time.
2253    
2254     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2255     now diagnosed as an error. Previously, most of the time, a negative number
2256     would have been treated as zero, but if in addition "ovector" was passed as
2257     NULL, a crash could occur.
2258    
2259     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2260     new versions from the libtool 1.5 distribution (the last one is a copy of
2261     a file called libtool.m4). This seems to have fixed the need to patch
2262     "configure" to support Darwin 1.3 (which I used to do). However, I still
2263     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2264     workstation).
2265    
2266     24. Changed the PCRE licence to be the more standard "BSD" licence.
2267    
2268    
2269 nigel 73 Version 4.5 01-Dec-03
2270     ---------------------
2271    
2272     1. There has been some re-arrangement of the code for the match() function so
2273     that it can be compiled in a version that does not call itself recursively.
2274     Instead, it keeps those local variables that need separate instances for
2275     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2276     needs to "recurse". Keeping track of where control must go is done by means
2277     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2278     hide most of the details from the main code, and operates only if
2279     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2280     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2281     operating.
2282    
2283     To make it easier for callers to provide specially tailored get/free
2284     functions for this usage, two new functions, pcre_stack_malloc, and
2285     pcre_stack_free, are used. They are always called in strict stacking order,
2286     and the size of block requested is always the same.
2287    
2288     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2289     PCRE has been compiled to use the stack or the heap for recursion. The
2290     -C option of pcretest uses this to show which version is compiled.
2291    
2292     A new data escape \S, is added to pcretest; it causes the amounts of store
2293     obtained and freed by both kinds of malloc/free at match time to be added
2294     to the output.
2295    
2296     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2297     what's available on my current Linux desktop machine.
2298    
2299     3. When matching a UTF-8 string, the test for a valid string at the start has
2300     been extended. If start_offset is not zero, PCRE now checks that it points
2301     to a byte that is the start of a UTF-8 character. If not, it returns
2302     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2303     this is necessary because there may be backward assertions in the pattern.
2304     When matching the same subject several times, it may save resources to use
2305     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2306    
2307     4. The code for checking the validity of UTF-8 strings has been tightened so
2308     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2309     containing "overlong sequences".
2310    
2311     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2312     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2313     should have been "&", but it just so happened that all the cases this let
2314     through by mistake were picked up later in the function.
2315    
2316     6. I had used a variable called "isblank" - this is a C99 function, causing
2317     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2318    
2319     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2320     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2321     so the version is shown; (c) stop "make test" echoing "./RunTest".
2322    
2323     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2324    
2325     9. The prototype for memmove() for systems that don't have it was using
2326     size_t, but the inclusion of the header that defines size_t was later. I've
2327     moved the #includes for the C headers earlier to avoid this.
2328    
2329     10. Added some adjustments to the code to make it easier to compiler on certain
2330     special systems:
2331    
2332     (a) Some "const" qualifiers were missing.
2333     (b) Added the macro EXPORT before all exported functions; by default this
2334     is defined to be empty.
2335     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2336     that it reads its output file name as an argument instead of writing
2337     to the standard output and assuming this can be redirected.
2338    
2339     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2340     class containing characters with values greater than 255, PCRE compilation
2341     went into a loop.
2342    
2343     12. A recursive reference to a subpattern that was within another subpattern
2344     that had a minimum quantifier of zero caused PCRE to crash. For example,
2345     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2346     recursion. If the recursively-called subpattern itself had a zero repeat,
2347     that was OK.
2348    
2349     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2350     buffer into which it was copied (for escape processing) was still set at
2351     1024, so long lines caused crashes.
2352    
2353     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2354     "internal error: code overflow...". This applied to any character class
2355     that was followed by a possessive quantifier.
2356    
2357     15. Modified the Makefile to add libpcre.la as a prerequisite for
2358     libpcreposix.la because I was told this is needed for a parallel build to
2359     work.
2360    
2361     16. If a pattern that contained .* following optional items at the start was
2362     studied, the wrong optimizing data was generated, leading to matching
2363     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2364     matching string must start with a or b or c. The correct conclusion for
2365     this pattern is that a match can start with any character.
2366    
2367    
2368 nigel 71 Version 4.4 13-Aug-03
2369     ---------------------
2370    
2371     1. In UTF-8 mode, a character class containing characters with values between
2372     127 and 255 was not handled correctly if the compiled pattern was studied.
2373     In fixing this, I have also improved the studying algorithm for such
2374     classes (slightly).
2375    
2376     2. Three internal functions had redundant arguments passed to them. Removal
2377     might give a very teeny performance improvement.
2378    
2379     3. Documentation bug: the value of the capture_top field in a callout is *one
2380     more than* the number of the hightest numbered captured substring.
2381    
2382     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2383     in incorrectly linking with a previously installed version. They now link
2384     explicitly with libpcre.la.
2385    
2386     5. configure.in no longer needs to recognize Cygwin specially.
2387    
2388     6. A problem in pcre.in for Windows platforms is fixed.
2389    
2390     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2391     pcretest, it used to include the size of the study block as part of its
2392     output. Unfortunately, the structure contains a field that has a different
2393     size on different hardware architectures. This meant that the tests that
2394     showed this size failed. As the block is currently always of a fixed size,
2395     this information isn't actually particularly useful in pcretest output, so
2396     I have just removed it.
2397    
2398     8. Three pre-processor statements accidentally did not start in column 1.
2399     Sadly, there are *still* compilers around that complain, even though
2400     standard C has not required this for well over a decade. Sigh.
2401    
2402     9. In pcretest, the code for checking callouts passed small integers in the
2403     callout_data field, which is a void * field. However, some picky compilers
2404     complained about the casts involved for this on 64-bit systems. Now
2405     pcretest passes the address of the small integer instead, which should get
2406     rid of the warnings.
2407    
2408     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2409     both compile and run time, and gives an error if an invalid UTF-8 sequence
2410     is found. There is a option for disabling this check in cases where the
2411     string is known to be correct and/or the maximum performance is wanted.
2412    
2413     11. In response to a bug report, I changed one line in Makefile.in from
2414    
2415     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2416     to
2417     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2418    
2419     to look similar to other lines, but I have no way of telling whether this
2420     is the right thing to do, as I do not use Windows. No doubt I'll get told
2421     if it's wrong...
2422    
2423    
2424 nigel 69 Version 4.3 21-May-03
2425     ---------------------
2426    
2427     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2428     Makefile.
2429    
2430     2. Some refactoring to improve the quality of the code:
2431    
2432     (i) The utf8_table... variables are now declared "const".
2433    
2434     (ii) The code for \cx, which used the "case flipping" table to upper case
2435     lower case letters, now just substracts 32. This is ASCII-specific,
2436     but the whole concept of \cx is ASCII-specific, so it seems
2437     reasonable.
2438    
2439     (iii) PCRE was using its character types table to recognize decimal and
2440     hexadecimal digits in the pattern. This is silly, because it handles
2441     only 0-9, a-f, and A-F, but the character types table is locale-
2442     specific, which means strange things might happen. A private
2443     table is now used for this - though it costs 256 bytes, a table is
2444     much faster than multiple explicit tests. Of course, the standard
2445     character types table is still used for matching digits in subject
2446     strings against \d.
2447    
2448     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2449     ending in _t are). So I've renamed it as ESC_tee.
2450    
2451     3. The first argument for regexec() in the POSIX wrapper should have been
2452     defined as "const".
2453    
2454     4. Changed pcretest to use malloc() for its buffers so that they can be
2455     Electric Fenced for debugging.
2456    
2457     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2458     to read one or more bytes before the start of the subject string. Often this
2459     had no effect on PCRE's behaviour, but in some circumstances it could
2460     provoke a segmentation fault.
2461    
2462     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2463     to try to read one or more bytes before the start of the subject string.
2464    
2465     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2466     UTF-8 support could misbehave in various ways if the subject string
2467     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2468     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2469     back over UTF-8 characters.)
2470    
2471    
2472 nigel 67 Version 4.2 14-Apr-03
2473     ---------------------
2474    
2475     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2476    
2477     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2478     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2479     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2480     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2481     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2482     and BUILD_EXEEXT
2483     Note: automatic setting of the BUILD variables is not yet working
2484     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2485     compile-time but not at link-time
2486     [LINK]: use for linking executables only
2487     make different versions for Windows and non-Windows
2488     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2489     libraries
2490     [LINK_FOR_BUILD]: new variable
2491     [OBJEXT]: use throughout
2492     [EXEEXT]: use throughout
2493     <winshared>: new target
2494     <wininstall>: new target
2495     <dftables.o>: use native compiler
2496     <dftables>: use native linker
2497     <install>: handle Windows platform correctly
2498     <clean>: ditto
2499     <check>: ditto
2500     copy DLL to top builddir before testing
2501    
2502     As part of these changes, -no-undefined was removed again. This was reported
2503     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2504     in any case.
2505    
2506     3. Some tidies to get rid of compiler warnings:
2507    
2508     . In the match_data structure, match_limit was an unsigned long int, whereas
2509     match_call_count was an int. I've made them both unsigned long ints.
2510    
2511     . In pcretest the fact that a const uschar * doesn't automatically cast to
2512     a void * provoked a warning.
2513    
2514     . Turning on some more compiler warnings threw up some "shadow" variables
2515     and a few more missing casts.
2516    
2517     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2518     option, a class that contained a single character with a value between 128
2519     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2520    
2521     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2522     option, a class that contained several characters, but with at least one
2523     whose value was between 128 and 255 caused PCRE to crash.
2524    
2525    
2526 nigel 65 Version 4.1 12-Mar-03
2527     ---------------------
2528 nigel 63
2529 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2530     needed, and a string in dftables.c that was longer than standard compilers are
2531     required to support.
2532    
2533     2. Compiling with Sun's compiler found a few more places where the code could
2534     be tidied up in order to avoid warnings.
2535    
2536     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2537     first of these names is deprecated in the latest Autoconf in favour of the name
2538     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2539     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2540     analogy I have changed it to CFLAGS_FOR_BUILD.
2541    
2542     4. Added -no-undefined to the linking command in the Makefile, because this is
2543     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2544     linking step for the pcreposix library.
2545    
2546     5. PCRE was failing to diagnose the case of two named groups with the same
2547     name.
2548    
2549     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2550     literal character that is needed in the subject for a match, and scans along to
2551     ensure that it is present before embarking on the full matching process. This
2552     saves time in cases of nested unlimited repeats that are never going to match.
2553     Problem: the scan can take a lot of time if the subject is very long (e.g.
2554     megabytes), thus penalizing straightforward matches. It is now done only if the
2555     amount of subject to be scanned is less than 1000 bytes.
2556    
2557     7. A lesser problem with the same optimization is that it was recording the
2558     first character of an anchored pattern as "needed", thus provoking a search
2559     right along the subject, even when the first match of the pattern was going to
2560     fail. The "needed" character is now not set for anchored patterns, unless it
2561     follows something in the pattern that is of non-fixed length. Thus, it still
2562     fulfils its original purpose of finding quick non-matches in cases of nested
2563     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2564    
2565    
2566     Version 4.0 17-Feb-03
2567     ---------------------
2568    
2569 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2570     extended to the end of string, PCRE compiled incorrect data. This could lead to
2571     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2572    
2573     2. Moved to autoconf 2.53 and libtool 1.4.2.
2574    
2575     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2576     the special perltest8 script is no longer needed - all the tests can be run
2577     from a single perltest script.
2578    
2579     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2580     by \s. It has now been removed in PCRE. This means it isn't recognized as
2581     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2582     class [:space:] *does* include VT, thereby creating a mess.
2583    
2584     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2585     space and tab.
2586    
2587     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2588     its new features into the main test script, reducing the number of scripts.
2589    
2590     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2591     were backward compatible, and made the (?i) apply to the whole pattern, as if
2592     /i were given. Now it behaves more logically, and applies the option setting
2593     only to what follows. PCRE has been changed to follow suit. However, if it
2594     finds options settings right at the start of the pattern, it extracts them into
2595     the global options, as before. Thus, they show up in the info data.
2596    
2597     8. Added support for the \Q...\E escape sequence. Characters in between are
2598     treated as literals. This is slightly different from Perl in that $ and @ are
2599     also handled as literals inside the quotes. In Perl, they will cause variable
2600     interpolation. Note the following examples:
2601    
2602     Pattern PCRE matches Perl matches
2603    
2604     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2605     \Qabc\$xyz\E abc\$xyz abc\$xyz
2606     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2607    
2608     For compatibility with Perl, \Q...\E sequences are recognized inside character
2609     classes as well as outside them.
2610    
2611     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2612     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2613     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2614     signed/unsigned warnings.
2615    
2616     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2617     option for pcretest, so I've replaced it by a simple function that does just
2618     that job.
2619    
2620     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2621     "pcregrep -".
2622    
2623     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2624     Java package. This provides some syntactic sugar for simple cases of what my
2625     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2626     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2627     item, you can use this simplified notation. Note that only makes sense with
2628     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2629     greediness, whatever the setting of the PCRE_UNGREEDY option.
2630    
2631     13. A change of greediness default within a pattern was not taking effect at
2632     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2633     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2634     was abstracted outside.
2635    
2636     14. PCRE now supports the \G assertion. It is true when the current matching
2637     position is at the start point of the match. This differs from \A when the
2638     starting offset is non-zero. Used with the /g option of pcretest (or similar
2639     code), it works in the same way as it does for Perl's /g option. If all
2640     alternatives of a regex begin with \G, the expression is anchored to the start
2641     match position, and the "anchored" flag is set in the compiled expression.
2642    
2643     15. Some bugs concerning the handling of certain option changes within patterns
2644     have been fixed. These applied to options other than (?ims). For example,
2645     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2646     been the other way round. Some of this was related to change 7 above.
2647    
2648     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2649     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2650     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2651     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2652    
2653     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2654     mode. Unlike ".", it always matches newline, whatever the setting of
2655     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2656     assertions. Perl allows it, but it doesn't (in general) work because it can't
2657     calculate the length of the lookbehind. At least, that's the case for Perl
2658     5.8.0 - I've been told they are going to document that it doesn't work in
2659     future.
2660    
2661     18. Added an error diagnosis for escapes that PCRE does not support: these are
2662     \L, \l, \N, \P, \p, \U, \u, and \X.
2663    
2664     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2665     reading past the end of the pattern in cases such as /[abcd/.
2666    
2667     20. PCRE was getting more memory than necessary for patterns with classes that
2668     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2669    
2670     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2671     compiling PCRE for use with Virtual Pascal.
2672    
2673     22. Small fix to the Makefile to make it work properly if the build is done
2674     outside the source tree.
2675    
2676     23. Added a new extension: a condition to go with recursion. If a conditional
2677     subpattern starts with (?(R) the "true" branch is used if recursion has
2678     happened, whereas the "false" branch is used only at the top level.
2679    
2680     24. When there was a very long string of literal characters (over 255 bytes
2681     without UTF support, over 250 bytes with UTF support), the computation of how
2682     much memory was required could be incorrect, leading to segfaults or other
2683     strange effects.
2684    
2685     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2686     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2687     there was a subsequent back reference to those brackets. This meant that, for
2688     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2689     possible to check for precisely this case. All we can do is abandon the
2690     optimization if .* occurs inside capturing brackets when there are any back
2691     references whatsoever. (See below for a better fix that came later.)
2692    
2693     26. The handling of the optimization for finding the first character of a
2694     non-anchored pattern, and for finding a character that is required later in the
2695     match were failing in some cases. This didn't break the matching; it just
2696     failed to optimize when it could. The way this is done has been re-implemented.
2697    
2698     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2699    
2700     28. Added a new feature that provides some of the functionality that Perl
2701     provides with (?{...}). The facility is termed a "callout". The way it is done
2702     in PCRE is for the caller to provide an optional function, by setting
2703     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2704     global variable. By default it is unset, which disables all calling out. To get
2705     the function called, the regex must include (?C) at appropriate points. This
2706     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2707     This provides a means of identifying different callout points. When PCRE
2708     reaches such a point in the regex, if pcre_callout has been set, the external
2709     function is called. It is provided with data in a structure called
2710     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2711     matching continues; if it returns a non-zero value, the match at the current
2712     point fails. However, backtracking will occur if possible. [This was changed
2713     later and other features added - see item 49 below.]
2714    
2715     29. pcretest is upgraded to test the callout functionality. It provides a
2716     callout function that displays information. By default, it shows the start of
2717     the match and the current position in the text. There are some new data escapes
2718     to vary what happens:
2719    
2720     \C+ in addition, show current contents of captured substrings
2721     \C- do not supply a callout function
2722     \C!n return 1 when callout number n is reached
2723     \C!n!m return 1 when callout number n is reached for the mth time
2724    
2725     30. If pcregrep was called with the -l option and just a single file name, it
2726     output "<stdin>" if a match was found, instead of the file name.
2727    
2728     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2729     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2730     pcre_exec(). This saves a malloc/free per call. The default value of
2731     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2732     when configuring.
2733    
2734     32. The default maximum size of a compiled pattern is 64K. There have been a
2735     few cases of people hitting this limit. The code now uses macros to handle the
2736     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2737     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2738     configuring. Tests 2 and 5 work only with 2-byte links because they output
2739     debugging information about compiled patterns.
2740    
2741     33. Internal code re-arrangements:
2742    
2743     (a) Moved the debugging function for printing out a compiled regex into
2744     its own source file (printint.c) and used #include to pull it into
2745     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2746     separate copies.
2747    
2748     (b) Defined the list of op-code names for debugging as a macro in
2749     internal.h so that it is next to the definition of the opcodes.
2750    
2751     (c) Defined a table of op-code lengths for simpler skipping along compiled
2752     code. This is again a macro in internal.h so that it is next to the
2753     definition of the opcodes.
2754    
2755     34. Added support for recursive calls to individual subpatterns, along the
2756     lines of Robin Houston's patch (but implemented somewhat differently).
2757    
2758     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2759     allow it to read and process whole directories in Win32. This code was
2760     contributed by Lionel Fourquaux; it has not been tested by me.
2761    
2762     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2763     used to name a group. Names consist of alphanumerics and underscores, and must
2764     be unique. Back references use the syntax (?P=name) and recursive calls use
2765     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2766     numbers. The function pcre_fullinfo() can be used after compilation to extract
2767     a name/number map. There are three relevant calls:
2768    
2769     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2770     PCRE_INFO_NAMECOUNT yields the number of entries
2771     PCRE_INFO_NAMETABLE yields a pointer to the map.
2772    
2773     The map is a vector of fixed-size entries. The size of each entry depends on
2774     the length of the longest name used. The first two bytes of each entry are the
2775     group number, most significant byte first. There follows the corresponding
2776     name, zero terminated. The names are in alphabetical order.
2777    
2778     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2779     case instead of 255. Making it the same both with and without UTF-8 support
2780     means that the same test output works with both.
2781    
2782     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2783     calling malloc() with a zero argument.
2784    
2785     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2786     optimization. I've improved things by keeping a bitmap of backreferences with
2787     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2788     fact referenced, the optimization can be applied. It is unlikely that a
2789     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2790     the match to follow \n) will appear inside brackets with a number greater than
2791     31, but if it does, any back reference > 31 suppresses the optimization.
2792    
2793     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2794     of disabling numbered capturing parentheses. Any opening parenthesis that is
2795     not followed by ? behaves as if it were followed by ?: but named parentheses
2796     can still be used for capturing (and they will acquire numbers in the usual
2797     way).
2798    
2799     41. Redesigned the return codes from the match() function into yes/no/error so
2800     that errors can be passed back from deep inside the nested calls. A malloc
2801     failure while inside a recursive subpattern call now causes the
2802     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2803    
2804     42. It is now possible to set a limit on the number of times the match()
2805     function is called in a call to pcre_exec(). This facility makes it possible to
2806     limit the amount of recursion and backtracking, though not in a directly
2807     obvious way, because the match() function is used in a number of different
2808     circumstances. The count starts from zero for each position in the subject
2809     string (for non-anchored patterns). The default limit is, for compatibility, a
2810     large number, namely 10 000 000. You can change this in two ways:
2811    
2812     (a) When configuring PCRE before making, you can use --with-match-limit=n
2813     to set a default value for the compiled library.
2814    
2815     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2816     a different value is set. See 45 below.
2817    
2818     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2819    
2820     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2821     of things that can be changed at compile time. The first argument specifies
2822     what is wanted and the second points to where the information is to be placed.
2823     The current list of available information is:
2824    
2825     PCRE_CONFIG_UTF8
2826    
2827     The output is an integer that is set to one if UTF-8 support is available;
2828     otherwise it is set to zero.
2829    
2830     PCRE_CONFIG_NEWLINE
2831    
2832     The output is an integer that it set to the value of the code that is used for
2833     newline. It is either LF (10) or CR (13).
2834    
2835     PCRE_CONFIG_LINK_SIZE
2836    
2837     The output is an integer that contains the number of bytes used for internal
2838     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2839    
2840     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2841    
2842     The output is an integer that contains the threshold above which the POSIX
2843     interface uses malloc() for output vectors. See item 31 above.
2844    
2845     PCRE_CONFIG_MATCH_LIMIT
2846    
2847     The output is an unsigned integer that contains the default limit of the number
2848     of match() calls in a pcre_exec() execution. See 42 above.
2849    
2850     44. pcretest has been upgraded by the addition of the -C option. This causes it
2851     to extract all the available output from the new pcre_config() function, and to
2852     output it. The program then exits immediately.
2853    
2854     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2855     order to support additional features. One way would have been to define
2856     pcre_exec2() (for example) with extra arguments, but this would not have been
2857     extensible, and would also have required all calls to the original function to
2858     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2859     is used for passing in "extra" data from pcre_study().
2860    
2861     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2862     contains the following fields:
2863    
2864     flags a bitmap indicating which of the following fields are set
2865     study_data opaque data from pcre_study()
2866     match_limit a way of specifying a limit on match() calls for a specific
2867     call to pcre_exec()
2868     callout_data data for callouts (see 49 below)
2869    
2870     The flag bits are also defined in pcre.h, and are
2871    
2872     PCRE_EXTRA_STUDY_DATA
2873     PCRE_EXTRA_MATCH_LIMIT
2874     PCRE_EXTRA_CALLOUT_DATA
2875    
2876     The pcre_study() function now returns one of these new pcre_extra blocks, with
2877     the actual study data pointed to by the study_data field, and the
2878     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2879     before. That is, this change is entirely upwards-compatible and requires no
2880     change to existing code.
2881    
2882     If you want to pass in additional data to pcre_exec(), you can either place it
2883     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2884     block.
2885    
2886     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2887     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2888     times with different match limits, until it finds the minimum value needed for
2889     pcre_exec() to complete. The value is then output. This can be instructive; for
2890     most simple matches the number is quite small, but for pathological cases it
2891     gets very large very quickly.
2892    
2893     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2894     returns the size of the data block pointed to by the study_data field in a
2895     pcre_extra block, that is, the value that was passed as the argument to
2896     pcre_malloc() when PCRE was getting memory in which to place the information
2897     created by pcre_study(). The fourth argument should point to a size_t variable.
2898     pcretest has been extended so that this information is shown after a successful
2899     pcre_study() call when information about the compiled regex is being displayed.
2900    
2901     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2902     because what follows is always an absolute path. (Later: it turns out that this
2903     is more than cosmetic for MinGW, because it doesn't like empty path
2904     components.)
2905    
2906     49. Some changes have been made to the callout feature (see 28 above):
2907    
2908     (i) A callout function now has three choices for what it returns:
2909    
2910     0 => success, carry on matching
2911     > 0 => failure at this point, but backtrack if possible
2912     < 0 => serious error, return this value from pcre_exec()
2913    
2914     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2915     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2916     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2917     use by callout functions. It will never be used by PCRE itself.
2918    
2919     (ii) The pcre_extra structure (see 45 above) has a void * field called
2920     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2921     pcre_callout_block structure has a field of the same name. The contents of
2922     the field passed in the pcre_extra structure are passed to the callout
2923     function in the corresponding field in the callout block. This makes it
2924     easier to use the same callout-containing regex from multiple threads. For
2925     testing, the pcretest program has a new data escape
2926    
2927     \C*n pass the number n (may be negative) as callout_data
2928    
2929     If the callout function in pcretest receives a non-zero value as
2930     callout_data, it returns that value.
2931    
2932     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2933     there were some redundant $(CFLAGS) in commands that are now specified as
2934     $(LINK), which already includes $(CFLAGS).
2935    
2936     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2937     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2938     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2939     one-byte characters throughout. Note that case-insensitive matching applies
2940     only to characters whose values are less than 256. PCRE doesn't support the
2941     notion of cases for higher-valued characters.
2942    
2943     (i) A character class whose characters are all within 0-255 is handled as
2944     a bit map, and the map is inverted for negative classes. Previously, a
2945     character > 255 always failed to match such a class; however it should
2946     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2947    
2948     (ii) A negated character class with a single character < 255 is coded as
2949     "not this character" (OP_NOT). This wasn't working properly when the test
2950     character was multibyte, either singly or repeated.
2951    
2952     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2953     mode, for example: \x{100}{2,3}.
2954    
2955     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2956     singly or repeated) now correctly test multibyte characters. However,
2957     PCRE doesn't recognize any characters with values greater than 255 as
2958     digits, spaces, or word characters. Such characters always match \D, \S,
2959     and \W, and never match \d, \s, or \w.
2960    
2961     (v) Classes may now contain characters and character ranges with values
2962     greater than 255. For example: [ab\x{100}-\x{400}].
2963    
2964     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2965     PCRE in UTF-8 mode.
2966    
2967     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2968     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2969     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2970     value.)
2971    
2972     53. The single man page has become too large. I have therefore split it up into
2973     a number of separate man pages. These also give rise to individual HTML pages;
2974     these are now put in a separate directory, and there is an index.html page that
2975     lists them all. Some hyperlinking between the pages has been installed.
2976    
2977     54. Added convenience functions for handling named capturing parentheses.
2978    
2979     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2980     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2981     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2982     are faulted.
2983    
2984     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2985     calling configure. These values are used when compiling the dftables.c program
2986     which is run to generate the source of the default character tables. They
2987     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2988     you will need to set these values.
2989    
2990     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2991    
2992    
2993     Version 3.9 02-Jan-02
2994 nigel 61 ---------------------
2995    
2996     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2997    
2998     2. If --disable-static was given, the building process failed when trying to
2999     build pcretest and pcregrep. (For some reason it was using libtool to compile
3000     them, which is not right, as they aren't part of the library.)
3001    
3002    
3003 nigel 59 Version 3.8 18-Dec-01
3004     ---------------------
3005    
3006     1. The experimental UTF-8 code was completely screwed up. It was packing the
3007     bytes in the wrong order. How dumb can you get?
3008    
3009    
3010 nigel 57 Version 3.7 29-Oct-01
3011     ---------------------
3012    
3013     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3014     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3015     this didn't happen under Solaris 8, where I normally test things.
3016    
3017 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3018     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3019     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3020     this fix an hour or so after the initial 3.7 release.)
3021 nigel 57
3022 nigel 59
3023 nigel 55 Version 3.6 23-Oct-01
3024     ---------------------
3025    
3026     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3027     offsets passed as NULL with zero offset count.
3028    
3029     2. The config.guess and config.sub files had not been updated when I moved to
3030     the latest autoconf.
3031    
3032    
3033 nigel 53 Version 3.5 15-Aug-01
3034     ---------------------
3035 nigel 5
3036 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3037     had been forgotten.
3038    
3039     2. By using declared but undefined structures, we can avoid using "void"
3040     definitions in pcre.h while keeping the internal definitions of the structures
3041     private.
3042    
3043     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3044     user point of view, this means that both static and shared libraries are built
3045     by default, but this can be individually controlled. More of the work of
3046     handling this static/shared cases is now inside libtool instead of PCRE's make
3047     file.
3048    
3049     4. The pcretest utility is now installed along with pcregrep because it is
3050     useful for users (to test regexs) and by doing this, it automatically gets
3051     relinked by libtool. The documentation has been turned into a man page, so
3052     there are now .1, .txt, and .html versions in /doc.
3053    
3054     5. Upgrades to pcregrep:
3055     (i) Added long-form option names like gnu grep.
3056     (ii) Added --help to list all options with an explanatory phrase.
3057     (iii) Added -r, --recursive to recurse into sub-directories.
3058     (iv) Added -f, --file to read patterns from a file.
3059    
3060     6. pcre_exec() was referring to its "code" argument before testing that
3061     argument for NULL (and giving an error if it was NULL).
3062    
3063     7. Upgraded Makefile.in to allow for compiling in a different directory from
3064     the source directory.
3065    
3066     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3067     options bits, the pointer it was passed was to an int instead of to an unsigned
3068     long int. This mattered only on 64-bit systems.
3069    
3070     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3071     generated) instead of pcre.in, which it its source. Also made the same change
3072     in several of the .c files.
3073    
3074     10. A new release of gcc defines printf() as a macro, which broke pcretest
3075     because it had an ifdef in the middle of a string argument for printf(). Fixed
3076     by using separate calls to printf().
3077    
3078     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3079     script, to force use of CR or LF instead of \n in the source. On non-Unix
3080     systems, the value can be set in config.h.
3081    
3082     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3083     absolute limit. Changed the text of the error message to make this clear, and
3084     likewise updated the man page.
3085    
3086     13. The limit of 99 on the number of capturing subpatterns has been removed.
3087     The new limit is 65535, which I hope will not be a "real" limit.
3088    
3089    
3090 nigel 51 Version 3.4 22-Aug-00
3091     ---------------------
3092    
3093     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3094    
3095     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3096    
3097    
3098 nigel 49 Version 3.3 01-Aug-00
3099     ---------------------
3100    
3101     1. If an octal character was given, but the value was greater than \377, it
3102     was not getting masked to the least significant bits, as documented. This could
3103     lead to crashes in some systems.
3104    
3105     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3106     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3107    
3108     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3109     These just pass their arguments on to (pcre_free)(), but they are provided
3110     because some uses of PCRE bind it to non-C systems that can call its functions,
3111     but cannot call free() or pcre_free() directly.
3112    
3113     4. Add "make test" as a synonym for "make check". Corrected some comments in
3114     the Makefile.
3115    
3116     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3117     Makefile.
3118    
3119     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3120     command called pgrep for grepping around the active processes.
3121    
3122     7. Added the beginnings of support for UTF-8 character strings.
3123    
3124     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3125     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3126     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3127     out for the ar command.)
3128    
3129    
3130 nigel 47 Version 3.2 12-May-00
3131     ---------------------
3132    
3133     This is purely a bug fixing release.
3134    
3135     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3136     of ZA. This was just one example of several cases that could provoke this bug,
3137     which was introduced by change 9 of version 2.00. The code for breaking
3138     infinite loops after an iteration that matches an empty string was't working
3139     correctly.
3140    
3141     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3142     when matched against abbab (for example). After matching an empty string, it
3143     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3144     caused it to match further down the string than it should.
3145    
3146     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3147     was there because it doesn't seem to be needed, and it causes trouble on some
3148     systems, as it is not a Standard C header. It has been removed.
3149    
3150     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3151     were reported on the Macintosh. The changes were from
3152    
3153     while ((c = *(++ptr)) != 0 && c != '\n');
3154     to
3155     while ((c = *(++ptr)) != 0 && c != '\n') ;
3156    
3157     Totally extraordinary, but if that's what it takes...
3158    
3159     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3160     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3161     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3162     assumes the way PCRE uses memmove() (always moving upwards).
3163    
3164     6. PCRE is being used in one environment where strchr() is not available. There
3165     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3166     faster code anyway.
3167    
3168    
3169 nigel 45 Version 3.1 09-Feb-00
3170     ---------------------
3171    
3172     The only change in this release is the fixing of some bugs in Makefile.in for
3173     the "install" target:
3174    
3175     (1) It was failing to install pcreposix.h.
3176    
3177     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3178    
3179    
3180 nigel 43 Version 3.0 01-Feb-00
3181     ---------------------
3182 nigel 41
3183     1. Add support for the /+ modifier to perltest (to output $` like it does in
3184     pcretest).
3185    
3186     2. Add support for the /g modifier to perltest.
3187    
3188     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3189     matches null strings.
3190    
3191     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3192     pattern. Perl treats empty patterns specially - it reuses the most recent
3193     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3194     effect.
3195    
3196     5. The POSIX interface was broken in that it was just handing over the POSIX
3197     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3198     required a bigger vector, with some working space on the end. This means that
3199     the POSIX wrapper now has to get and free some memory, and copy the results.
3200    
3201 nigel 43 6. Added some simple autoconf support, placing the test data and the
3202     documentation in separate directories, re-organizing some of the
3203     information files, and making it build pcre-config (a GNU standard). Also added
3204     libtool support for building PCRE as a shared library, which is now the
3205     default.
3206 nigel 41
3207 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3208     09 are not valid octal constants. Single digits will be used for minor values
3209     less than 10.
3210    
3211     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3212     existing programs that set these in the POSIX interface can use PCRE without
3213     modification.
3214    
3215     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3216     return all that pcre_info() returns, plus additional data. The pcre_info()
3217     function is retained for compatibility, but is considered to be obsolete.
3218    
3219     10. Added experimental recursion feature (?R) to handle one common case that
3220     Perl 5.6 will be able to do with (?p{...}).
3221    
3222     11. Added support for POSIX character classes like [:alpha:], which Perl is
3223     adopting.
3224    
3225    
3226 nigel 39 Version 2.08 31-Aug-99
3227     ----------------------
3228    
3229     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3230     trying to match at the startoffset position, but instead was moving forward to
3231     the next newline as if a previous match had failed.
3232    
3233     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3234     and could get into a loop if a null string was matched other than at the start
3235     of the subject.
3236    
3237     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3238     be distinguished at compile time, and for completeness also added PCRE_DATE.
3239    
3240     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3241     in GnuWin32 environments.
3242    
3243    
3244 nigel 37 Version 2.07 29-Jul-99
3245     ----------------------
3246    
3247     1. The documentation is now supplied in plain text form and HTML as well as in
3248     the form of man page sources.
3249    
3250     2. C++ compilers don't like assigning (void *) values to other pointer types.
3251     In particular this affects malloc(). Although there is no problem in Standard
3252     C, I've put in casts to keep C++ compilers happy.
3253    
3254     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3255     should be (const char *).
3256    
3257     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3258     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3259     However, I haven't made this a standard facility. The documentation doesn't
3260     mention it, and the Makefile doesn't support it.
3261    
3262     5. The Makefile now contains an "install" target, with editable destinations at
3263     the top of the file. The pcretest program is not installed.
3264    
3265     6. pgrep -V now gives the PCRE version number and date.
3266    
3267     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3268     causing the entire string to be ignored, instead of just the last character.
3269    
3270     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3271     non-matching string, it can take a very, very long time, even for strings of
3272     quite modest length, because of the nested recursion. PCRE now does better in
3273     some of these cases. It does this by remembering the last required literal
3274     character in the pattern, and pre-searching the subject to ensure it is present
3275     before running the real match. In other words, it applies a heuristic to detect
3276     some types of certain failure quickly, and in the above example, if presented
3277     with a string that has no trailing " it gives "no match" very quickly.
3278    
3279     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3280     other alternatives are tried instead.
3281    
3282    
3283 nigel 35 Version 2.06 09-Jun-99
3284     ----------------------
3285    
3286     1. Change pcretest's output for amount of store used to show just the code
3287     space, because the remainder (the data block) varies in size between 32-bit and
3288     64-bit systems.
3289    
3290     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3291     start matching at. This allows lookbehinds to work when searching for multiple
3292     occurrences in a string.
3293    
3294     3. Added additional options to pcretest for testing multiple occurrences:
3295    
3296     /+ outputs the rest of the string that follows a match
3297     /g loops for multiple occurrences, using the new startoffset argument
3298     /G loops for multiple occurrences by passing an incremented pointer
3299    
3300     4. PCRE wasn't doing the "first character" optimization for patterns starting
3301     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3302     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3303     the letter 'x'. On long subject strings, this gives a significant speed-up.
3304    
3305    
3306 nigel 33 Version 2.05 21-Apr-99
3307     ----------------------
3308    
3309     1. Changed the type of magic_number from int to long int so that it works
3310     properly on 16-bit systems.
3311    
3312     2. Fixed a bug which caused patterns starting with .* not to work correctly
3313     when the subject string contained newline characters. PCRE was assuming
3314     anchoring for such patterns in all cases, which is not correct because .* will
3315     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3316     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3317     must be retried after every newline in the subject.
3318    
3319    
3320 nigel 31 Version 2.04 18-Feb-99
3321     ----------------------
3322    
3323     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3324     computation of the store needed to hold the pattern was incorrect (too large).
3325     If such patterns were nested a few deep, this could multiply and become a real
3326     problem.
3327    
3328     2. Added /M option to pcretest to show the memory requirement of a specific
3329     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3330    
3331     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3332     compiled in such a way that the backtracking after subsequent failure was
3333     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3334     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3335    
3336    
3337 nigel 29 Version 2.03 02-Feb-99
3338     ----------------------
3339    
3340     1. Fixed typo and small mistake in man page.
3341    
3342 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3343     LICENCE file containing the conditions.
3344 nigel 29
3345     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3346     Perl, that is the internal \ allows the delimiter to be included in the
3347     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3348     the final delimiter, add \ to the end of the pattern (to test the error).
3349    
3350     4. Added the convenience functions for extracting substrings after a successful
3351     match. Updated pcretest to make it able to test these functions.
3352    
3353    
3354 nigel 27 Version 2.02 14-Jan-99
3355     ----------------------
3356    
3357     1. Initialized the working variables associated with each extraction so that
3358     their saving and restoring doesn't refer to uninitialized store.
3359    
3360     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3361     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3362     fix the problem.
3363    
3364     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3365     calls, and wasn't printing the correct value for compiling calls. Increased the
3366     default value of LOOPREPEAT, and the number of significant figures in the
3367     times.
3368    
3369     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3370    
3371     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3372     a building problem on Windows NT with a FAT file system.
3373    
3374    
3375 nigel 25 Version 2.01 21-Oct-98
3376     ----------------------
3377    
3378     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3379     to character tables built by pcre_maketables() in the current locale. If NULL
3380     is passed, the default tables are used.
3381    
3382    
3383 nigel 23 Version 2.00 24-Sep-98
3384 nigel 21 ----------------------
3385    
3386 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3387     it any more.
3388    
3389     2. Allow quantification of (?>) groups, and make it work correctly.
3390    
3391     3. The first character computation wasn't working for (?>) groups.
3392    
3393     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3394     end of the subject) and add 5.005's \z, which really does match only at the
3395     very end of the subject.
3396    
3397     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3398    
3399     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3400     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3401     localized options. All options to pcre_study() were also removed.
3402    
3403     7. Add other new features from 5.005:
3404    
3405     $(?<= positive lookbehind
3406     $(?<! negative lookbehind
3407     (?imsx-imsx) added the unsetting capability
3408     such a setting is global if at outer level; local otherwise
3409     (?imsx-imsx:) non-capturing groups with option setting
3410     (?(cond)re|re) conditional pattern matching
3411    
3412     A backreference to itself in a repeated group matches the previous
3413     captured string.
3414    
3415     8. General tidying up of studying (both automatic and via "study")
3416     consequential on the addition of new assertions.
3417    
3418     9. As in 5.005, unlimited repeated groups that could match an empty substring
3419     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3420     runtime if any iteration does actually match an empty substring.
3421    
3422     10. Include the RunTest script in the distribution.
3423    
3424     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3425     discrepancies, some of which were old and were also with respect to 5.004. They
3426     have now been fixed.
3427    
3428    
3429     Version 1.09 28-Apr-98
3430     ----------------------
3431    
3432 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3433     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3434     program crashes, or just wrong answers. This did not apply to negated classes
3435     containing more than one character, or to minima other than one.
3436    
3437    
3438 nigel 19 Version 1.08 27-Mar-98
3439     ----------------------
3440    
3441     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3442    
3443     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3444     latter must appear before anything that relies on it in the pattern.
3445    
3446    
3447 nigel 17 Version 1.07 16-Feb-98
3448     ----------------------
3449    
3450     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3451     repeat of a potentially empty string).
3452    
3453    
3454 nigel 15 Version 1.06 23-Jan-98
3455     ----------------------
3456    
3457     1. Added Markus Oberhumer's little patches for C++.
3458    
3459     2. Literal strings longer than 255 characters were broken.
3460    
3461    
3462 nigel 13 Version 1.05 23-Dec-97
3463     ----------------------
3464    
3465     1. Negated character classes containing more than one character were failing if
3466     PCRE_CASELESS was set at run time.
3467    
3468    
3469 nigel 11 Version 1.04 19-Dec-97
3470     ----------------------
3471    
3472     1. Corrected the man page, where some "const" qualifiers had been omitted.
3473    
3474     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3475     input syntax.
3476    
3477     3. Fixed memory leak which occurred when a regex with back references was
3478     matched with an offsets vector that wasn't big enough. The temporary memory
3479     that is used in this case wasn't being freed if the match failed.
3480    
3481     4. Tidied pcretest to ensure it frees memory that it gets.
3482    
3483     5. Temporary memory was being obtained in the case where the passed offsets
3484     vector was exactly big enough.
3485    
3486     6. Corrected definition of offsetof() from change 5 below.
3487    
3488     7. I had screwed up change 6 below and broken the rules for the use of
3489     setjmp(). Now fixed.
3490    
3491    
3492 nigel 9 Version 1.03 18-Dec-97
3493     ----------------------
3494    
3495     1. A erroneous regex with a missing opening parenthesis was correctly
3496     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3497     on some systems.
3498    
3499     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3500     it was reported that one broken compiler failed on the former because "code" is
3501     also an independent variable.
3502    
3503     3. The erroneous regex a[]b caused an array overrun reference.
3504    
3505     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3506     fail on data ending with that character. (It was going on too far, and checking
3507     the next character, typically a binary zero.) This was specific to the
3508     optimized code for single-character negative classes.
3509    
3510     5. Added a contributed patch from the TIN world which does the following:
3511    
3512     + Add an undef for memmove, in case the the system defines a macro for it.
3513    
3514     + Add a definition of offsetof(), in case there isn't one. (I don't know
3515     the reason behind this - offsetof() is part of the ANSI standard - but
3516     it does no harm).
3517    
3518     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3519     most of the places where whitespace preceded '#'. I have given up and
3520     allowed the remaining 2 cases to be at the margin.
3521    
3522     + Rename some variables in pcre to eliminate shadowing. This seems very
3523     pedantic, but does no harm, of course.
3524    
3525     6. Moved the call to setjmp() into its own function, to get rid of warnings
3526     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3527    
3528     7. Constructs such as \d{8,} were compiling into the equivalent of
3529 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3530 nigel 9 outcome, but in this particular case used more store than had been allocated,
3531     which caused the bug to be discovered because it threw up an internal error.
3532    
3533     8. The debugging code in both pcre and pcretest for outputting the compiled
3534     form of a regex was going wrong in the case of back references followed by
3535     curly-bracketed repeats.
3536    
3537    
3538 nigel 7 Version 1.02 12-Dec-97
3539     ----------------------
3540    
3541     1. Typos in pcre.3 and comments in the source fixed.
3542    
3543     2. Applied a contributed patch to get rid of places where it used to remove
3544     'const' from variables, and fixed some signed/unsigned and uninitialized
3545     variable warnings.
3546    
3547     3. Added the "runtest" target to Makefile.
3548    
3549     4. Set default compiler flag to -O2 rather than just -O.
3550    
3551    
3552 nigel 5 Version 1.01 19-Nov-97
3553     ----------------------
3554    
3555     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3556     like /([ab]*)*/, that is, for classes with more than one character in them.
3557    
3558     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3559     as /((?>a*))*/ (a PCRE_EXTRA facility).
3560    
3561    
3562     Version 1.00 18-Nov-97
3563     ----------------------
3564    
3565     1. Added compile-time macros to support systems such as SunOS4 which don't have
3566     memmove() or strerror() but have other things that can be used instead.
3567    
3568     2. Arranged that "make clean" removes the executables.
3569    
3570    
3571 nigel 3 Version 0.99 27-Oct-97
3572     ----------------------
3573    
3574     1. Fixed bug in code for optimizing classes with only one character. It was
3575     initializing a 32-byte map regardless, which could cause it to run off the end
3576     of the memory it had got.
3577    
3578     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3579    
3580    
3581     Version 0.98 22-Oct-97
3582     ----------------------
3583    
3584     1. Fixed bug in code for handling temporary memory usage when there are more
3585     back references than supplied space in the ovector. This could cause segfaults.
3586    
3587    
3588     Version 0.97 21-Oct-97
3589     ----------------------
3590    
3591     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3592    
3593     2. Optimized negated single characters not to use a bit map.
3594    
3595     3. Brought error texts together as macro definitions; clarified some of them;
3596     fixed one that was wrong - it said "range out of order" when it meant "invalid
3597     escape sequence".
3598    
3599     4. Changed some char * arguments to const char *.
3600    
3601     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3602    
3603     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3604     pcretest.
3605    
3606    
3607     Version 0.96 16-Oct-97
3608     ----------------------
3609    
3610     1. Added a simple "pgrep" utility to the distribution.
3611    
3612     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3613     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3614     where "ddd" means "one or more decimal digits".
3615    
3616     3. Fixed serious bug. If a pattern had a back reference, but the call to
3617     pcre_exec() didn't supply a large enough ovector to record the related
3618     identifying subpattern, the match always failed. PCRE now remembers the number
3619     of the largest back reference, and gets some temporary memory in which to save
3620     the offsets during matching if necessary, in order to ensure that
3621     backreferences always work.
3622    
3623     4. Increased the compatibility with Perl in a number of ways:
3624    
3625     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3626     to request this handling. The option can be set at compile or exec time.
3627    
3628     (b) $ matches before a terminating newline by default; an option
3629     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3630     mode). The option can be set at compile or exec time.
3631    
3632     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3633     the same as Perl's. If the decimal number it represents is less than 10
3634     or there aren't that many previous left capturing parentheses, an octal
3635     escape is read. Inside a character class, it's always an octal escape,
3636     even if it is a single digit.
3637    
3638     (d) An escaped but undefined alphabetic character is taken as a literal,
3639     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3640     escapes.
3641    
3642     (e) {0} is now permitted. (The previous item is removed from the compiled
3643     pattern).
3644    
3645     5. Changed all the names of code files so that the basic parts are no longer
3646     than 10 characters, and abolished the teeny "globals.c" file.
3647    
3648     6. Changed the handling of character classes; they are now done with a 32-byte
3649     bit map always.
3650    
3651     7. Added the -d and /D options to pcretest to make it possible to look at the
3652     internals of compilation without having to recompile pcre.
3653    
3654    
3655     Version 0.95 23-Sep-97
3656     ----------------------
3657    
3658     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3659     \x20 at the start of a run of normal characters. These were being treated as
3660     real characters, instead of the source characters being re-checked.
3661    
3662    
3663     Version 0.94 18-Sep-97
3664     ----------------------
3665    
3666     1. The functions are now thread-safe, with the caveat that the global variables
3667     containing pointers to malloc() and free() or alternative functions are the
3668     same for all threads.
3669    
3670     2. Get pcre_study() to generate a bitmap of initial characters for non-
3671     anchored patterns when this is possible, and use it if passed to pcre_exec().
3672    
3673    
3674     Version 0.93 15-Sep-97
3675     ----------------------
3676    
3677     1. /(b)|(:+)/ was computing an incorrect first character.
3678    
3679     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3680     but not actually doing anything yet.
3681    
3682     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3683     as Perl does (e.g. [-az] or [az-]).
3684    
3685     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3686     all possible positions.
3687    
3688     5. Split up into different modules to avoid including unneeded functions in a
3689     compiled binary. However, compile and exec are still in one module. The "study"
3690     function is split off.
3691    
3692     6. The character tables are now in a separate module whose source is generated
3693     by an auxiliary program - but can then be edited by hand if required. There are
3694     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3695     toupper() in the code.
3696    
3697     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3698     make them global. Abolish the function for setting them, as the caller can now
3699     set them directly.
3700    
3701    
3702     Version 0.92 11-Sep-97
3703     ----------------------
3704    
3705     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3706     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3707    
3708     2. Caseless matching was not working in character classes if the characters in
3709     the pattern were in upper case.
3710    
3711     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3712    
3713     4. Make PCRE_ANCHORED public and accept as a compile option.
3714    
3715     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3716     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3717     pass them.
3718    
3719     6. Give an error if bad option bits passed at compile or run time.
3720    
3721     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3722     pcretest to cause it to pass that flag.
3723    
3724     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3725     options, and the first character, if set.
3726    
3727     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3728    
3729    
3730     Version 0.91 10-Sep-97
3731     ----------------------
3732    
3733     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3734     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3735    
3736     2. PCRE was looping on encountering an indefinitely repeated back reference to
3737     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3738     Perl does - treats the match as successful.
3739    
3740     ****

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