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Revision 480 - (hide annotations) (download)
Sun Jan 3 17:29:59 2010 UTC (4 years, 9 months ago) by ph10
File size: 178695 byte(s)
Update stack documentation to be clearer about pcre_dfa_exec().

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 471 Version 8.01 11-Dec-09
5     ----------------------
6    
7     1. If a pattern contained a conditional subpattern with only one branch (in
8 ph10 473 particular, this includes all (DEFINE) patterns), a call to pcre_study()
9     computed the wrong minimum data length (which is of course zero for such
10 ph10 471 subpatterns).
11 ph10 473
12     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
13 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
14     "internal error: code overflow at offset...". This happened only when
15 ph10 473 the reset was to the original external option setting. (An optimization
16     abstracts leading options settings into an external setting, which was the
17 ph10 472 cause of this.)
18 ph10 471
19 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
20     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
21     assertion pattern did not match (meaning that the assertion was true), it
22     was incorrectly treated as false if the SKIP had been reached during the
23     matching. This also applied to assertions used as conditions.
24 ph10 471
25 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
26     assertion subpattern, including such a pattern used as a condition,
27     unpredictable results occurred, instead of the error return
28     PCRE_ERROR_DFA_UITEM.
29 ph10 478
30 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
31     situation when an empty string is matched. It now does the fancy magic
32 ph10 478 stuff that is necessary.
33    
34     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
35 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
36 ph10 478
37 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
38     as part of something else:
39 ph10 478
40     (a) Change DEBUG to PCRE_DEBUG.
41    
42     (b) In pcre_compile(), rename the member of the "branch_chain" structure
43     called "current" as "current_branch", to prevent a collision with the
44 ph10 475 Linux macro when compiled as a kernel module.
45 ph10 478
46     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
47     prevent a collision with the Linux macro when compiled as a kernel
48 ph10 475 module.
49 ph10 478
50 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
51     cast potentially large values to (double). This has been changed to that
52 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
53     instead, thus avoiding the use of floating point arithmetic. (There is no
54     other use of FP in PCRE.) If int64_t is not found, the fallback is to
55     double.
56    
57     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
58 ph10 476 2005 (difference between two addresses compared to an unsigned value).
59 ph10 473
60 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
61     custom one, because of the following reported problem in Windows:
62 ph10 473
63 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
64     under Win32.
65     - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
66     therefore missing the function definition.
67     - The compiler thus generates a "C" signature for the test function.
68     - The linker fails to find the "C" function.
69     - PCRE fails to configure if asked to do so against libbz2.
70 ph10 479
71     11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
72     messages were output:
73 ph10 478
74 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
75     rerunning libtoolize, to keep the correct libtool macros in-tree.
76     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
77    
78     I have done both of these things.
79 ph10 480
80     12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
81     most of the time, it *can* run out if it is given a pattern that contains a
82     runaway infinite recursion. I updated the discussion in the pcrestack man
83     page.
84 ph10 479
85 ph10 478
86 ph10 479
87 ph10 469 Version 8.00 19-Oct-09
88 ph10 418 ----------------------
89    
90     1. The table for translating pcre_compile() error codes into POSIX error codes
91 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
92     being within the table. This could lead to an OK return being given in
93 ph10 418 error.
94 ph10 461
95     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
96     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
97     in a Windows environment.
98    
99 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
100     zero, as does GNU grep. However, pcregrep was also printing all files when
101     --files-with-matches was added. Now, when both options are given, it prints
102     counts only for those files that have at least one match. (GNU grep just
103 ph10 461 prints the file name in this circumstance, but including the count seems
104     more useful - otherwise, why use --count?) Also ensured that the
105 ph10 420 combination -clh just lists non-zero counts, with no names.
106 ph10 461
107     4. The long form of the pcregrep -F option was incorrectly implemented as
108     --fixed_strings instead of --fixed-strings. This is an incompatible change,
109     but it seems right to fix it, and I didn't think it was worth preserving
110     the old behaviour.
111    
112     5. The command line items --regex=pattern and --regexp=pattern were not
113 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
114 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
115 ph10 422 which are compatible with GNU grep; these now work.
116 ph10 461
117     6. No libpcreposix.pc file was created for pkg-config; there was just
118 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
119 ph10 461
120 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
121 ph10 461 when UCP support is not needed, by modifying the Python script that
122 ph10 425 generates it from Unicode data files. This should not matter if the module
123     is correctly used as a library, but I received one complaint about 50K of
124     unwanted data. My guess is that the person linked everything into his
125     program rather than using a library. Anyway, it does no harm.
126 ph10 461
127 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
128 ph10 461 was a minimum greater than 1 for a wide character in a possessive
129 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
130     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
131     character. Chaos in the form of incorrect output or a compiling loop could
132     result.
133 ph10 461
134 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
135 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
136 ph10 426 partially matched by this function. In addition, if there are at least two
137 ph10 435 slots in the offset vector, the offset of the earliest inspected character
138     for the match and the offset of the end of the subject are set in them when
139 ph10 461 PCRE_ERROR_PARTIAL is returned.
140    
141 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
142     synonymous with PCRE_PARTIAL, for backwards compatibility, and
143     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
144 ph10 462 and may be more useful for multi-segment matching.
145 ph10 461
146     11. Partial matching with pcre_exec() is now more intuitive. A partial match
147     used to be given if ever the end of the subject was reached; now it is
148     given only if matching could not proceed because another character was
149     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
150     string "Z", which now yields "no match" instead of "partial match". In the
151     case of pcre_dfa_exec(), "no match" is given if every matching path for the
152     final character ended with (*FAIL).
153    
154 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
155 ph10 461 if the pattern had a "must contain" character that was already found in the
156 ph10 428 earlier partial match, unless partial matching was again requested. For
157     example, with the pattern /dog.(body)?/, the "must contain" character is
158     "g". If the first part-match was for the string "dog", restarting with
159 ph10 435 "sbody" failed. This bug has been fixed.
160 ph10 461
161     13. The string returned by pcre_dfa_exec() after a partial match has been
162     changed so that it starts at the first inspected character rather than the
163     first character of the match. This makes a difference only if the pattern
164     starts with a lookbehind assertion or \b or \B (\K is not supported by
165     pcre_dfa_exec()). It's an incompatible change, but it makes the two
166 ph10 435 matching functions compatible, and I think it's the right thing to do.
167 ph10 461
168 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
169 ph10 461 so that the demonstration program is easily available in environments where
170     PCRE has not been installed from source.
171    
172 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
173 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
174     library.
175 ph10 461
176 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
177 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
178 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
179 ph10 433 these options useful.
180 ph10 461
181     17. If a caller to the POSIX matching function regexec() passes a non-zero
182 ph10 438 value for nmatch with a NULL value for pmatch, the value of
183 ph10 461 nmatch is forced to zero.
184    
185 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
186 ph10 461 the diff command, as RunTest does. It now checks in the same way as
187 ph10 437 RunTest, and also checks for the -b option.
188 ph10 461
189 ph10 438 19. If an odd number of negated classes containing just a single character
190     interposed, within parentheses, between a forward reference to a named
191 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
192     an internal error, complaining that it could not find the referenced
193 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
194 ph10 461 [The bug was that it was starting one character too far in when skipping
195     over the character class, thus treating the ] as data rather than
196     terminating the class. This meant it could skip too much.]
197    
198 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
199 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
200 ph10 442 to have an empty string match not at the start, even when the pattern is
201 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
202    
203 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
204 ph10 461 than the maximum at the outer level, the higher number was returned, but
205     with unset values at the outer level. The correct (outer level) value is
206 ph10 446 now given.
207 ph10 461
208 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
209     PCRE did not set those parentheses (unlike Perl). I have now found a way to
210     make it do so. The string so far is captured, making this feature
211     compatible with Perl.
212 ph10 461
213     23. The tests have been re-organized, adding tests 11 and 12, to make it
214 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
215 ph10 461
216 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
217 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
218     does. Neither allows recursion.
219    
220     25. I finally figured out how to implement a request to provide the minimum
221     length of subject string that was needed in order to match a given pattern.
222     (It was back references and recursion that I had previously got hung up
223     on.) This code has now been added to pcre_study(); it finds a lower bound
224 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
225     bound, but using it to avoid searching strings that are too short does give
226     some useful speed-ups. The value is available to calling programs via
227     pcre_fullinfo().
228 ph10 461
229 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
230     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
231     study optimizations had never been tested with that matching function.
232     Oops. What is worse, even when it was passed study data, there was a bug in
233     pcre_dfa_exec() that meant it never actually used it. Double oops. There
234     were also very few tests of studied patterns with pcre_dfa_exec().
235 ph10 461
236 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
237     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
238     on the other side of the coin, they are no longer allowed to have different
239     names, because these cannot be distinguished in PCRE, and this has caused
240     confusion. (This is a difference from Perl.)
241 ph10 461
242     28. When duplicate subpattern names are present (necessarily with different
243     numbers, as required by 27 above), and a test is made by name in a
244     conditional pattern, either for a subpattern having been matched, or for
245     recursion in such a pattern, all the associated numbered subpatterns are
246 ph10 459 tested, and the overall condition is true if the condition is true for any
247     one of them. This is the way Perl works, and is also more like the way
248     testing by number works.
249 ph10 418
250 ph10 461
251 ph10 412 Version 7.9 11-Apr-09
252 ph10 376 ---------------------
253    
254 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
255 ph10 376 (pcretest), all targets were linked against these libraries. This included
256     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
257     libraries. This caused unwanted dependencies to be created. This problem
258 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
259 ph10 376 pcretest is linked with readline.
260 ph10 392
261 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
262     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
263     moved outside it again, because FALSE and TRUE are already defined in AIX,
264     but BOOL is not.
265 ph10 392
266     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
267 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
268 ph10 392
269 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
270     hyphens) following file names and line numbers when outputting matching
271 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
272 ph10 376 wording for the --colour (or --color) option.
273 ph10 392
274 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
275     was not coloured; this is different to GNU grep, so I have changed it to be
276     the same.
277 ph10 392
278 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
279 ph10 392 each matching line was coloured. Now it goes on to look for further matches
280     of any of the test patterns, which is the same behaviour as GNU grep.
281    
282     7. A pattern that could match an empty string could cause pcregrep to loop; it
283     doesn't make sense to accept an empty string match in pcregrep, so I have
284 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
285     seems to be how GNU grep behaves.
286 ph10 392
287 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
288 ph10 392 start or after a newline", because the conditional assertion was not being
289     correctly handled. The rule now is that both the assertion and what follows
290     in the first alternative must satisfy the test.
291    
292 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
293 ph10 399 condition was an assertion, PCRE could crash during matching, both with
294     pcre_exec() and pcre_dfa_exec().
295 ph10 392
296     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
297     used for matching.
298    
299     11. Unicode property support in character classes was not working for
300 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
301 ph10 388
302 ph10 392 12. Added the -M command line option to pcretest.
303    
304 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
305 ph10 389
306     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
307 ph10 390
308 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
309 ph10 390 wrapper.
310 ph10 392
311 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
312 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
313 ph10 391 string constants.
314 ph10 405
315 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
316     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
317 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
318     these, but not everybody uses configure.
319    
320     19. A conditional group that had only one branch was not being correctly
321     recognized as an item that could match an empty string. This meant that an
322     enclosing group might also not be so recognized, causing infinite looping
323     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
324     with the subject "ab", where knowledge that the repeated group can match
325 ph10 396 nothing is needed in order to break the loop.
326 ph10 405
327 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
328 ph10 405 exec(), but without supplying a callout function, matching went wrong.
329    
330     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
331     leak if the size of the offset vector was greater than 30. When the vector
332     is smaller, the saved offsets during recursion go onto a local stack
333     vector, but for larger vectors malloc() is used. It was failing to free
334     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
335 ph10 400 error, in fact).
336 ph10 405
337 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
338 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
339     problem, but was untidy.
340 ph10 376
341 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
342     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
343     included within another project.
344 ph10 411
345 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
346     slightly modified by me:
347 ph10 411
348     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
349     not building pcregrep.
350    
351 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
352 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
353    
354 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
355     duplicate group numbers, could behave incorrectly or give incorrect errors,
356     because when scanning forward to find the reference group, PCRE was not
357     taking into account the duplicate group numbers. A pattern such as
358     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
359 ph10 411
360     26. Changed a few more instances of "const unsigned char *" to USPTR, making
361     the feature of a custom pointer more persuasive (as requested by a user).
362 ph10 416
363 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
364 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
365     pre-defined.
366 ph10 392
367 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
368    
369 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
370     in the configuration summary.
371 ph10 405
372 ph10 411
373 ph10 374 Version 7.8 05-Sep-08
374 ph10 349 ---------------------
375    
376     1. Replaced UCP searching code with optimized version as implemented for Ad
377     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
378 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
379     to 5 times on some simple patterns that I tested. Permission was given to
380     distribute the MultiStage2.py script that generates the tables (it's not in
381     the tarball, but is in the Subversion repository).
382 ph10 349
383 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
384     scripts.
385 ph10 358
386 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
387     a group with a zero qualifier. The result of the study could be incorrect,
388 ph10 358 or the function might crash, depending on the pattern.
389    
390     4. Caseless matching was not working for non-ASCII characters in back
391 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
392 ph10 358 It now works when Unicode Property Support is available.
393    
394 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
395     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
396     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
397 ph10 358 truncation.
398 ph10 349
399 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
400    
401 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
402     pointers, in case they are 64-bit values.
403 ph10 371
404     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
405     test 2 if it fails.
406    
407 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
408 ph10 371 and a #define of that name to empty if it is not externally set. This is to
409     allow users of MSVC to set it if necessary.
410    
411     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
412 ph10 359 the convenience functions in the pcre_get.c source file.
413 ph10 371
414 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
415     could cause overwriting and/or a crash. This command provoked a crash in
416 ph10 371 some environments:
417    
418     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
419    
420 ph10 360 This potential security problem was recorded as CVE-2008-2371.
421 ph10 371
422 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
423     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
424 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
425 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
426     pcretest so that it places the subject at the end of its malloc-ed buffer.
427 ph10 371
428 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
429 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
430    
431 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
432 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
433     first line. This applied both to normal and DFA matching.
434    
435 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
436 ph10 371 /^[^d]*?$/8 failed to match "abc".
437 ph10 351
438 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
439    
440     17. Make it more clear in the documentation that values returned from
441 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
442 ph10 357
443 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
444 ph10 368
445 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
446     supplied by Stefan Weber. I made a further small update for 7.8 because
447 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
448     replaced by pcre_ucd.c.
449 ph10 371
450 ph10 373
451 ph10 347 Version 7.7 07-May-08
452 ph10 321 ---------------------
453    
454     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
455 ph10 345 a string to a long long, pretend we don't even have a long long." This is
456 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
457 ph10 345
458 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
459     pre-7.6 versions, which defined a global no_arg variable instead of putting
460 ph10 332 it in the RE class. (See also #8 below.)
461 ph10 345
462     3. Remove a line of dead code, identified by coverity and reported by Nuno
463     Lopes.
464    
465 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
466 ph10 321
467 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
468 ph10 345 of files, instead of just to the final components.
469    
470 ph10 324 (2) If there was more than one level of directory, the subdirectories were
471     skipped unless they satisfied the include/exclude conditions. This is
472     inconsistent with GNU grep (and could even be seen as contrary to the
473     pcregrep specification - which I improved to make it absolutely clear).
474     The action now is always to scan all levels of directory, and just
475     apply the include/exclude patterns to regular files.
476 ph10 345
477 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
478 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
479    
480 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
481 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
482 ph10 326 doesn't support NULs in patterns.
483 ph10 345
484     7. Added some missing "const"s to declarations of static tables in
485     pcre_compile.c and pcre_dfa_exec.c.
486    
487 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
488 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
489 ph10 345 first patch. And a third patch - this was a messy problem.)
490 ph10 321
491 ph10 345 9. Applied Craig's patch to remove the use of push_back().
492    
493 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
494     matching function regexec().
495 ph10 345
496     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
497     which, however, unlike Perl's \g{...}, are subroutine calls, not back
498 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
499     Oniguruma does).
500 ph10 345
501     12. Previously, a group with a zero repeat such as (...){0} was completely
502 ph10 335 omitted from the compiled regex. However, this means that if the group
503     was called as a subroutine from elsewhere in the pattern, things went wrong
504 ph10 345 (an internal error was given). Such groups are now left in the compiled
505     pattern, with a new opcode that causes them to be skipped at execution
506 ph10 335 time.
507 ph10 345
508 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
509     to the way PCRE behaves:
510 ph10 345
511 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
512 ph10 345
513     (b) A back reference to an unmatched subpattern matches an empty string
514 ph10 336 (Perl fails the current match path).
515 ph10 345
516 ph10 341 (c) A data ] in a character class must be notated as \] because if the
517 ph10 345 first data character in a class is ], it defines an empty class. (In
518 ph10 341 Perl it is not possible to have an empty class.) The empty class []
519     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
520     The negative empty class [^] matches any one character, independently
521     of the DOTALL setting.
522 ph10 345
523     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
524 ph10 340 non-existent subpattern following a character class starting with ']' and
525     containing () gave an internal compiling error instead of "reference to
526     non-existent subpattern". Fortunately, when the pattern did exist, the
527 ph10 345 compiled code was correct. (When scanning forwards to check for the
528 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
529 ph10 345 the class, so got the count wrong. When actually compiling, the reference
530 ph10 340 was subsequently set up correctly.)
531 ph10 345
532 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
533 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
534     other assertions are supported. I have made pcre_dfa_exec() support
535     (*FAIL).
536    
537 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
538 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
539     cannot be changed at match time, I realized I could make a small
540     improvement to matching performance by compiling OP_ALLANY instead of
541     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
542     on the OP_ANY path.
543    
544     17. Compiling pcretest on Windows with readline support failed without the
545 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
546 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
547    
548 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
549 ph10 345 ncurses library to be included for pcretest when ReadLine support is
550     requested, but also to allow for it to be overridden. This patch came from
551     Daniel Bergström.
552 ph10 347
553 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
554 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
555     any errors with the current Unicode tables. Thanks to Peter Kankowski for
556     spotting this.
557 ph10 324
558 ph10 332
559 ph10 319 Version 7.6 28-Jan-08
560 ph10 300 ---------------------
561    
562 ph10 302 1. A character class containing a very large number of characters with
563     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
564     overflow.
565 ph10 309
566     2. Patch to cut out the "long long" test in pcrecpp_unittest when
567     HAVE_LONG_LONG is not defined.
568    
569 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
570 ph10 304 bring them up to date and include new features. This patch includes:
571 ph10 309
572 ph10 304 - Fixed PH's badly added libz and libbz2 support.
573     - Fixed a problem with static linking.
574 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
575 ph10 304 - Fixed dftables problem and added an option.
576     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
577     HAVE_LONG_LONG.
578     - Added readline support for pcretest.
579 ph10 309 - Added an listing of the option settings after cmake has run.
580    
581 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
582     "pcre.dll" under mingw when using Configure/Make. I added stuff to
583     Makefile.am that cause it to include this special target, without
584     affecting anything else. Note that the same mingw target plus all
585     the other distribution libraries and programs are now supported
586     when configuring with CMake (see 6 below) instead of with
587     Configure/Make.
588 ph10 309
589 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
590     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
591 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
592     solves the problem, but it does no harm.
593 ph10 313
594 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
595 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
596 ph10 314 with CMake, and also correct the comment about stack recursion.
597 ph10 313
598 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
599 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
600     of a program that users should build themselves after PCRE is installed, so
601     building it automatically is not really right. What is more, it gave
602 ph10 312 trouble in some build environments.
603 ph10 300
604 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
605 ph10 308
606 ph10 319
607 ph10 298 Version 7.5 10-Jan-08
608 ph10 263 ---------------------
609    
610     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
611     values in parens when parsing an RE using the C++ wrapper."
612 ph10 286
613 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
614     Characters greater than 255 were excluded from the class instead of being
615     included.
616 ph10 286
617     3. The same bug as (2) above applied to negated POSIX classes such as
618 ph10 265 [:^space:].
619 ph10 286
620 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
621     defined or documented. It seems to have been a typo for PCRE_STATIC, so
622 ph10 286 I have changed it.
623    
624 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
625 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
626     first named subpattern whose name started with "a" (in other words, the
627 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
628     expected" is now given for (?&) (a zero-length name), and this patch also
629     makes it give the same error for \k'' (previously it complained that that
630     was a reference to a non-existent subpattern).
631 ph10 286
632 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
633 ph10 286 this is right because (?- can be followed by option settings as well as by
634 ph10 269 digits. I have, however, made the messages clearer.
635 ph10 286
636 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
637     than the number used in the conditional) now cause a compile-time error.
638     This is actually not compatible with Perl, which accepts such patterns, but
639     treats the conditional as always being FALSE (as PCRE used to), but it
640     seems to me that giving a diagnostic is better.
641 ph10 286
642 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
643 ph10 275 and messages.
644 ph10 286
645     9. Fix two occurrences of "backslash" in comments that should have been
646     "backspace".
647    
648     10. Remove two redundant lines of code that can never be obeyed (their function
649     was moved elsewhere).
650    
651     11. The program that makes PCRE's Unicode character property table had a bug
652     which caused it to generate incorrect table entries for sequences of
653 ph10 277 characters that have the same character type, but are in different scripts.
654 ph10 286 It amalgamated them into a single range, with the script of the first of
655 ph10 277 them. In other words, some characters were in the wrong script. There were
656     thirteen such cases, affecting characters in the following ranges:
657 ph10 286
658 ph10 277 U+002b0 - U+002c1
659     U+0060c - U+0060d
660 ph10 286 U+0061e - U+00612
661 ph10 277 U+0064b - U+0065e
662     U+0074d - U+0076d
663     U+01800 - U+01805
664     U+01d00 - U+01d77
665     U+01d9b - U+01dbf
666     U+0200b - U+0200f
667     U+030fc - U+030fe
668     U+03260 - U+0327f
669     U+0fb46 - U+0fbb1
670     U+10450 - U+1049d
671 ph10 286
672 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
673     compatible with GNU grep in that, if there was more than one match in a
674     line, it showed only the first of them. It now behaves in the same way as
675     GNU grep.
676 ph10 286
677     13. If the -o and -v options were combined for pcregrep, it printed a blank
678     line for every non-matching line. GNU grep prints nothing, and pcregrep now
679     does the same. The return code can be used to tell if there were any
680     non-matching lines.
681    
682 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
683    
684     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
685 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
686 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
687     and both kinds of lookbehind were skipped).
688    
689 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
690 ph10 284 inclusion of <windows.h> to before rather than after the definition of
691     INVALID_FILE_ATTRIBUTES (patch from David Byron).
692 ph10 263
693 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
694 ph10 286 character property caused pcre_compile() to compile bad code, which led at
695     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
696     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
697     caused the error; without that there was no problem.
698 ph10 263
699 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
700 ph10 286
701 ph10 289 19. Added --enable-pcretest-libreadline.
702 ph10 286
703 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
704 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
705 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
706     later patch that removed the other one (the right fix) and added unit tests
707     that check the return values (which was not done before).
708 ph10 292
709 ph10 291 21. Several CMake things:
710 ph10 287
711 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
712 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
713 ph10 288
714 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
715     linked with the newly-built libraries, not previously installed ones.
716 ph10 291
717 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
718 ph10 298
719     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
720     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
721     UTF-8 newline character). The key issue is that the pattern starts .*;
722     this means that the match must be either at the beginning, or after a
723     newline. The bug was in the code for advancing after a failed match and
724     checking that the new position followed a newline. It was not taking
725 ph10 294 account of UTF-8 characters correctly.
726 ph10 298
727     23. PCRE was behaving differently from Perl in the way it recognized POSIX
728     character classes. PCRE was not treating the sequence [:...:] as a
729     character class unless the ... were all letters. Perl, however, seems to
730     allow any characters between [: and :], though of course it rejects as
731     unknown any "names" that contain non-letters, because all the known class
732     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
733     for example, whereas PCRE did not - it did not recognize a POSIX character
734     class. This seemed a bit dangerous, so the code has been changed to be
735     closer to Perl. The behaviour is not identical to Perl, because PCRE will
736     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
737     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
738     Perl does, and where it didn't before.
739    
740 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
741     Windows environments %n is disabled by default.
742 ph10 292
743    
744 ph10 260 Version 7.4 21-Sep-07
745 ph10 230 ---------------------
746    
747     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
748 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
749     LF". That isn't really right - the whole point of the change was to try to
750     help when there was an actual mention of one of the two characters. So now
751     the change happens only if \r or \n (or a literal CR or LF) character is
752 ph10 230 encountered.
753 ph10 231
754     2. The 32-bit options word was also used for 6 internal flags, but the numbers
755     of both had grown to the point where there were only 3 bits left.
756     Fortunately, there was spare space in the data structure, and so I have
757     moved the internal flags into a new 16-bit field to free up more option
758 ph10 230 bits.
759 ph10 231
760     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
761     but did not set the internal JCHANGED flag - either of these is enough to
762     control the way the "get" function works - but the PCRE_INFO_JCHANGED
763     facility is supposed to tell if (?J) was ever used, so now (?J) at the
764 ph10 230 start sets both bits.
765    
766 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
767     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
768 ph10 230
769 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
770    
771     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
772 ph10 233 compatibility, even though it is no longer used.
773 ph10 243
774     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
775 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
776 ph10 259 windows.h file is present (where different names are used). [This was
777 ph10 257 reversed later after testing - see 16 below.]
778 ph10 243
779     8. Changed all #include <config.h> to #include "config.h". There were also
780 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
781 ph10 243
782 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
783 ph10 243 sequence off the lines that it output.
784    
785     10. It was pointed out to me that arrays of string pointers cause lots of
786     relocations when a shared library is dynamically loaded. A technique of
787     using a single long string with a table of offsets can drastically reduce
788     these. I have refactored PCRE in four places to do this. The result is
789 ph10 240 dramatic:
790 ph10 243
791 ph10 240 Originally: 290
792     After changing UCP table: 187
793 ph10 243 After changing error message table: 43
794 ph10 240 After changing table of "verbs" 36
795     After changing table of Posix names 22
796 ph10 243
797 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
798 ph10 247
799 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
800 ph10 247 unicode-properties was also set.
801    
802 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
803 ph10 231
804 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
805     checked only for CRLF.
806 ph10 233
807 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
808    
809 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
810 ph10 253
811 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
812 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
813     entirely. This removes changes made in 7 above.
814 ph10 256
815 ph10 261 17. The CMake files have been updated, and there is now more information about
816     building with CMake in the NON-UNIX-USE document.
817 ph10 257
818 ph10 261
819 ph10 228 Version 7.3 28-Aug-07
820 ph10 157 ---------------------
821    
822 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
823     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
824     brackets there is not right, since it causes compilers to look for an
825     installed pcre.h, not the version that is in the source that is being
826     compiled (which of course may be different). I have changed it back to:
827 ph10 197
828 ph10 189 #include "pcre.h"
829 ph10 197
830     I have a vague recollection that the change was concerned with compiling in
831     different directories, but in the new build system, that is taken care of
832     by the VPATH setting the Makefile.
833    
834 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
835     when the subject happened to end in the byte 0x85 (e.g. if the last
836     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
837     characters but of course it shouldn't be taken as a newline when it is part
838     of another character. The bug was that, for an unlimited repeat of . in
839     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
840     characters when looking for a newline.
841 ph10 197
842     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
843    
844     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
845     in debug output.
846    
847 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
848     long printing in the pcrecpp unittest when running under MinGW.
849 ph10 189
850 ph10 197 6. ESC_K was left out of the EBCDIC table.
851 ph10 189
852 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
853     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
854     limit also applies to "virtual nesting" when a pattern is recursive, and in
855     this case 1000 isn't so big. I have been able to remove this limit at the
856     expense of backing off one optimization in certain circumstances. Normally,
857     when pcre_exec() would call its internal match() function recursively and
858     immediately return the result unconditionally, it uses a "tail recursion"
859     feature to save stack. However, when a subpattern that can match an empty
860     string has an unlimited repetition quantifier, it no longer makes this
861     optimization. That gives it a stack frame in which to save the data for
862     checking that an empty string has been matched. Previously this was taken
863     from the 1000-entry workspace that had been reserved. So now there is no
864     explicit limit, but more stack is used.
865 ph10 189
866 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
867     syntax that is required for Windows, and which was going wrong for the
868     pcreposix and pcrecpp parts of the library. These were overlooked when this
869     problem was solved for the main library.
870 ph10 197
871 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
872     the size of patterns that contain repeated groups with explicit upper
873     limits. As the maximum quantifier is 65535, the maximum group length was
874     set at 30,000 so that the product of these two numbers did not overflow a
875     32-bit integer. However, it turns out that people want to use groups that
876     are longer than 30,000 bytes (though not repeat them that many times).
877     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
878     made it possible to implement the integer overflow checks in a much more
879     dynamic way, which I have now done. The artificial limitation on group
880     length has been removed - we now have only the limit on the total length of
881     the compiled pattern, which depends on the LINK_SIZE setting.
882 ph10 208
883     10. Fixed a bug in the documentation for get/copy named substring when
884     duplicate names are permitted. If none of the named substrings are set, the
885     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
886     empty string.
887    
888     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
889     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
890     because the ] is interpreted as the first data character and the
891     terminating ] is not found. PCRE has been made compatible with Perl in this
892     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
893     cause memory overwriting.
894    
895 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
896     string has been matched (to stop an infinite loop). It was not recognizing
897 ph10 208 a conditional subpattern that could match an empty string if that
898 ph10 206 subpattern was within another subpattern. For example, it looped when
899 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
900 ph10 206 condition was not nested. This bug has been fixed.
901 ph10 208
902 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
903     past the start of the subject in the presence of bytes with the top bit
904     set, for example "\x8aBCD".
905 ph10 211
906 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
907     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
908 ph10 200
909 ph10 211 14. Optimized (?!) to (*FAIL).
910 ph10 202
911 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
912     This restricts code points to be within the range 0 to 0x10FFFF, excluding
913     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
914     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
915     does: it's just the validity check that is more restrictive.
916 ph10 220
917     16. Inserted checks for integer overflows during escape sequence (backslash)
918     processing, and also fixed erroneous offset values for syntax errors during
919     backslash processing.
920    
921 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
922 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
923    
924 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
925     caused an overrun.
926 ph10 220
927     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
928     something other than just ASCII characters) inside a group that had an
929     unlimited repeat caused a loop at compile time (while checking to see
930     whether the group could match an empty string).
931    
932 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
933     [\P{Any}] did so. (Error in the code for printing property names.)
934 ph10 210
935 ph10 220 21. An orphan \E inside a character class could cause a crash.
936    
937     22. A repeated capturing bracket such as (A)? could cause a wild memory
938 ph10 218 reference during compilation.
939 ph10 220
940     23. There are several functions in pcre_compile() that scan along a compiled
941     expression for various reasons (e.g. to see if it's fixed length for look
942 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
943 ph10 220 present in the pattern. These operators have additional parameters compared
944     with \d, etc, and these were not being taken into account when moving along
945 ph10 218 the compiled data. Specifically:
946 ph10 220
947     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
948     length.
949    
950     (b) An item such as \pL+ within a repeated group could cause crashes or
951 ph10 218 loops.
952 ph10 220
953 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
954 ph10 220 "reference to non-existent subpattern" error.
955    
956 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
957    
958 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
959 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
960 ph10 211
961 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
962 ph10 218
963 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
964 ph10 223 character were causing crashes (broken optimization).
965 ph10 227
966 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
967 ph10 227 \p or \P) caused a compile-time loop.
968    
969 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
970     break. For example, the unstudied pattern [\r\n]A does not match the string
971     "\r\nA" because change 7.0/46 below moves the current point on by two
972     characters after failing to match at the start. However, the pattern \nA
973 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
974     the same is true. There doesn't seem any very clean way out of this, but
975     what I have chosen to do makes the common cases work: PCRE now takes note
976     of whether there can be an explicit match for \r or \n anywhere in the
977     pattern, and if so, 7.0/46 no longer applies. As part of this change,
978     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
979     pattern has explicit CR or LF references.
980 ph10 222
981 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
982 ph10 223
983 ph10 227
984 ph10 189 Version 7.2 19-Jun-07
985     ---------------------
986    
987 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
988     which is apparently normally available under Windows.
989 ph10 159
990     2. Re-jig the pcregrep tests with different newline settings in an attempt
991     to make them independent of the local environment's newline setting.
992 ph10 157
993 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
994 ph10 165
995 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
996     was not 2, because the output contained actual offsets. The recent new
997 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
998     usable with all link sizes.
999    
1000 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1001     stack recursion. This gives a massive performance boost under BSD, but just
1002 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1003 ph10 164 in all cases.
1004 ph10 172
1005 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1006 ph10 172
1007 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1008     recursion call. It refers to the nth most recently opened parentheses.
1009 ph10 172
1010 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1011 ph10 172 to be opened parentheses.
1012    
1013     (c) Conditions that refer to capturing parentheses can be specified
1014 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1015 ph10 172
1016 ph10 168 (d) \K resets the start of the current match so that everything before
1017 ph10 172 is not part of it.
1018    
1019 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1020 ph10 172
1021 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1022 ph10 172 reference syntax.
1023 ph10 182
1024 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1025 ph10 182 alternative starts with the same number.
1026 ph10 172
1027 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1028    
1029 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1030     PCRE_INFO_JCHANGED.
1031    
1032     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1033     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1034 ph10 170 for detecting groups that can match an empty string.
1035 ph10 159
1036 ph10 172 9. A pattern with a very large number of alternatives (more than several
1037     hundred) was running out of internal workspace during the pre-compile
1038     phase, where pcre_compile() figures out how much memory will be needed. A
1039     bit of new cunning has reduced the workspace needed for groups with
1040     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1041     workspace instead of running out of the 4096 that are available.
1042 ph10 182
1043 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1044 ph10 172
1045 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1046     The report of the bug said:
1047 ph10 182
1048 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1049     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1050 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1051 ph10 185
1052 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1053 ph10 185 it matched the wrong number of bytes.
1054 ph10 172
1055 ph10 179
1056 ph10 155 Version 7.1 24-Apr-07
1057 ph10 98 ---------------------
1058    
1059 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1060 ph10 122 that is more "standard", making use of automake and other Autotools. There
1061 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1062     on this.
1063 ph10 111
1064     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1065     for recursive directory scanning broke on some systems because the files
1066     are not scanned in any specific order and on different systems the order
1067     was different. A call to "sort" has been inserted into RunGrepTest for the
1068     approprate test as a short-term fix. In the longer term there may be an
1069 ph10 100 alternative.
1070 ph10 111
1071 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1072 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1073     people do their own conversions for various reasons). The problems
1074     concerned the use of low-level troff macros .br and .in. I have therefore
1075     removed all such uses from the man pages (some were redundant, some could
1076 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1077     HTML has been updated to handle .nf/.fi and to complain if it encounters
1078     .br or .in.
1079 ph10 111
1080 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1081 ph10 123 arranged for config.h to be included in the distribution, with the name
1082 ph10 111 config.h.generic, for the benefit of those who have to compile without
1083     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1084    
1085     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1086     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1087 ph10 127 makevp.bat for the current PCRE, using the additional files
1088 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1089 ph10 111
1090     6. A Windows user reported a minor discrepancy with test 2, which turned out
1091     to be caused by a trailing space on an input line that had got lost in his
1092 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1093 ph10 111
1094 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1095 ph10 111 that is needed.
1096    
1097 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1098     as "const" (a) because they are and (b) because it helps the PHP
1099     maintainers who have recently made a script to detect big data structures
1100 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1101     to update Builducptable as well, so it won't revert if ucptable.h is ever
1102 ph10 105 re-created.
1103 ph10 111
1104     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1105 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1106 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1107     support is not required. This saves 1.5-2K of code, which is important in
1108 ph10 107 some applications.
1109 ph10 111
1110 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1111 ph10 111 so as not to refer to the tables, even though these functions will never be
1112     called when UTF-8 support is disabled. Otherwise there are problems with a
1113     shared library.
1114    
1115 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1116    
1117     (a) It was defining its arguments as char * instead of void *.
1118    
1119 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1120     a long time ago when I wrote it, but is no longer the case.
1121    
1122 ph10 118 The emulated memove() is provided for those environments that have neither
1123 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1124 ph10 118 is clearly not the case, as these two bugs were recently reported.
1125 ph10 123
1126 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1127 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1128     pages, and it removes trailing spaces from listed files. It also creates
1129     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1130     case, it wraps all the #defines with #ifndefs. This script should be run
1131 ph10 111 before "make dist".
1132 ph10 123
1133 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1134     with Unicode property support.
1135 ph10 123
1136     (a) For a maximizing quantifier, if the two different cases of the
1137     character were of different lengths in their UTF-8 codings (there are
1138     some cases like this - I found 11), and the matching function had to
1139 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1140     were both the same length.
1141 ph10 123
1142     (b) When PCRE was configured to use the heap rather than the stack for
1143     recursion during matching, it was not correctly preserving the data for
1144     the other case of a UTF-8 character when checking ahead for a match
1145     while processing a minimizing repeat. If the check also involved
1146 ph10 115 matching a wide character, but failed, corruption could cause an
1147     erroneous result when trying to check for a repeat of the original
1148     character.
1149 ph10 123
1150 ph10 116 13. Some tidying changes to the testing mechanism:
1151 ph10 98
1152 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1153     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1154 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1155     this for UTF-8.) The configure.ac script no longer substitutes the
1156     relevant variables.
1157    
1158 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1159     with length and offset values. This means that the output is different
1160     for different internal link sizes. Test 2 is skipped for link sizes
1161     other than 2 because of this, bypassing the problem. Unfortunately,
1162     there was also a test in test 3 (the locale tests) that used /B and
1163 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1164     I have added a new /Z option to pcretest that replaces the length and
1165     offset values with spaces. This is now used to make test 3 independent
1166 ph10 122 of link size. (Test 2 will be tidied up later.)
1167 ph10 123
1168     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1169 ph10 122 segmentation fault instead of returning the appropriate error message.
1170 ph10 134
1171 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1172 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1173     This doesn't seem right; it now treats the CRLF combination as the line
1174     ending, and so does not match in that case. It's only a pattern such as ^$
1175     that would hit this one: something like ^ABC$ would have failed after \r
1176     and then tried again after \r\n.
1177    
1178 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1179 ph10 134 in an attempt to make files that differ only in their line terminators
1180     compare equal. This works on Linux.
1181 ph10 142
1182 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1183     as it exited. This is now fixed, thanks to valgrind.
1184 ph10 142
1185 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1186 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1187     was because its rules for how to advance for /g after matching an empty
1188 ph10 143 string at the end of a line did not allow for this case. They now check for
1189     it specially.
1190 ph10 150
1191     20. pcretest is supposed to handle patterns and data of any length, by
1192     extending its buffers when necessary. It was getting this wrong when the
1193 ph10 147 buffer for a data line had to be extended.
1194 ph10 150
1195 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1196 ph10 150 CRLF as a newline sequence.
1197 ph10 152
1198 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1199 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1200     I have nevertheless tidied it up.
1201 ph10 111
1202 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1203 ph10 123
1204 ph10 153 24. Added a man page for pcre-config.
1205 ph10 152
1206 ph10 153
1207 nigel 93 Version 7.0 19-Dec-06
1208     ---------------------
1209    
1210     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1211     moving to gcc 4.1.1.
1212    
1213     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1214     sys/time.h, which is documented as needed for this function. It doesn't
1215     seem to matter on Linux, but it showed up on some releases of OS X.
1216    
1217     3. It seems that there are systems where bytes whose values are greater than
1218     127 match isprint() in the "C" locale. The "C" locale should be the
1219     default when a C program starts up. In most systems, only ASCII printing
1220     characters match isprint(). This difference caused the output from pcretest
1221     to vary, making some of the tests fail. I have changed pcretest so that:
1222    
1223     (a) When it is outputting text in the compiled version of a pattern, bytes
1224     other than 32-126 are always shown as hex escapes.
1225    
1226     (b) When it is outputting text that is a matched part of a subject string,
1227     it does the same, unless a different locale has been set for the match
1228     (using the /L modifier). In this case, it uses isprint() to decide.
1229    
1230     4. Fixed a major bug that caused incorrect computation of the amount of memory
1231     required for a compiled pattern when options that changed within the
1232     pattern affected the logic of the preliminary scan that determines the
1233     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1234     that the computed length was too small. The symptoms of this bug were
1235     either the PCRE error "internal error: code overflow" from pcre_compile(),
1236     or a glibc crash with a message such as "pcretest: free(): invalid next
1237     size (fast)". Examples of patterns that provoked this bug (shown in
1238     pcretest format) are:
1239    
1240     /(?-x: )/x
1241     /(?x)(?-x: \s*#\s*)/
1242     /((?i)[\x{c0}])/8
1243     /(?i:[\x{c0}])/8
1244    
1245     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1246     is now done differently.
1247    
1248     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1249     wrapper classes; (b) implement a new function in the C++ scanner that is
1250     more efficient than the old way of doing things because it avoids levels of
1251     recursion in the regex matching; (c) add a paragraph to the documentation
1252     for the FullMatch() function.
1253    
1254     6. The escape sequence \n was being treated as whatever was defined as
1255     "newline". Not only was this contrary to the documentation, which states
1256     that \n is character 10 (hex 0A), but it also went horribly wrong when
1257     "newline" was defined as CRLF. This has been fixed.
1258    
1259     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1260     was being set to -1 for the "end of line" case (supposedly a value that no
1261     character can have). Though this value is never used (the check for end of
1262     line is "zero bytes in current character"), it caused compiler complaints.
1263     I've changed it to 0xffffffff.
1264    
1265     8. In pcre_version.c, the version string was being built by a sequence of
1266     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1267     string (as it is for production releases) called a macro with an empty
1268     argument. The C standard says the result of this is undefined. The gcc
1269     compiler treats it as an empty string (which was what was wanted) but it is
1270     reported that Visual C gives an error. The source has been hacked around to
1271     avoid this problem.
1272    
1273     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1274     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1275     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1276     of them did).
1277    
1278     10. Originally, pcretest opened its input and output without "b"; then I was
1279     told that "b" was needed in some environments, so it was added for release
1280     5.0 to both the input and output. (It makes no difference on Unix-like
1281     systems.) Later I was told that it is wrong for the input on Windows. I've
1282     now abstracted the modes into two macros, to make it easier to fiddle with
1283     them, and removed "b" from the input mode under Windows.
1284    
1285     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1286    
1287     12. Added -help and --help to pcretest as an official way of being reminded
1288     of the options.
1289    
1290     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1291     and pcrecpp.cc because they annoy compilers at high warning levels.
1292    
1293     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1294    
1295     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1296     scripts are not C programs :-) and which was not noticed because it works
1297     on Linux.
1298    
1299     16. pcretest is supposed to handle any length of pattern and data line (as one
1300     line or as a continued sequence of lines) by extending its input buffer if
1301     necessary. This feature was broken for very long pattern lines, leading to
1302     a string of junk being passed to pcre_compile() if the pattern was longer
1303     than about 50K.
1304    
1305     17. I have done a major re-factoring of the way pcre_compile() computes the
1306     amount of memory needed for a compiled pattern. Previously, there was code
1307     that made a preliminary scan of the pattern in order to do this. That was
1308     OK when PCRE was new, but as the facilities have expanded, it has become
1309     harder and harder to keep it in step with the real compile phase, and there
1310     have been a number of bugs (see for example, 4 above). I have now found a
1311     cunning way of running the real compile function in a "fake" mode that
1312     enables it to compute how much memory it would need, while actually only
1313     ever using a few hundred bytes of working memory and without too many
1314     tests of the mode. This should make future maintenance and development
1315     easier. A side effect of this work is that the limit of 200 on the nesting
1316     depth of parentheses has been removed (though this was never a serious
1317     limitation, I suspect). However, there is a downside: pcre_compile() now
1318     runs more slowly than before (30% or more, depending on the pattern). I
1319     hope this isn't a big issue. There is no effect on runtime performance.
1320    
1321     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1322     newline (only possible for the last line of a file) and it was a
1323     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1324    
1325     19. Added additional timing features to pcretest. (1) The -tm option now times
1326     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1327     separate command line item, by a number that specifies the number of
1328     repeats to use when timing. The default is 50000; this gives better
1329     precision, but takes uncomfortably long for very large patterns.
1330    
1331     20. Extended pcre_study() to be more clever in cases where a branch of a
1332     subpattern has no definite first character. For example, (a*|b*)[cd] would
1333     previously give no result from pcre_study(). Now it recognizes that the
1334     first character must be a, b, c, or d.
1335    
1336     21. There was an incorrect error "recursive call could loop indefinitely" if
1337     a subpattern (or the entire pattern) that was being tested for matching an
1338     empty string contained only one non-empty item after a nested subpattern.
1339     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1340     incorrectly, because the \d was being skipped in the check.
1341    
1342     22. The pcretest program now has a new pattern option /B and a command line
1343     option -b, which is equivalent to adding /B to every pattern. This causes
1344     it to show the compiled bytecode, without the additional information that
1345     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1346     is the same as /B/I).
1347    
1348     23. A new optimization is now able automatically to treat some sequences such
1349     as a*b as a*+b. More specifically, if something simple (such as a character
1350     or a simple class like \d) has an unlimited quantifier, and is followed by
1351     something that cannot possibly match the quantified thing, the quantifier
1352     is automatically "possessified".
1353    
1354     24. A recursive reference to a subpattern whose number was greater than 39
1355     went wrong under certain circumstances in UTF-8 mode. This bug could also
1356     have affected the operation of pcre_study().
1357    
1358     25. Realized that a little bit of performance could be had by replacing
1359     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1360    
1361     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1362    
1363     27. Possessive quantifiers such as a++ were previously implemented by turning
1364     them into atomic groups such as ($>a+). Now they have their own opcodes,
1365     which improves performance. This includes the automatically created ones
1366     from 23 above.
1367    
1368     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1369     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1370     the first matched character to be a colon. This applied both to named and
1371     numbered groups.
1372    
1373     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1374    
1375     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1376     building PCRE on Windows easier, so I have included it in the distribution.
1377    
1378     31. There is now a check in pcretest against a ridiculously large number being
1379     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1380     loop, the loop is abandoned.
1381    
1382     32. Forward references to subpatterns in conditions such as (?(2)...) where
1383     subpattern 2 is defined later cause pcre_compile() to search forwards in
1384     the pattern for the relevant set of parentheses. This search went wrong
1385     when there were unescaped parentheses in a character class, parentheses
1386     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1387    
1388     33. "Subroutine" calls and backreferences were previously restricted to
1389     referencing subpatterns earlier in the regex. This restriction has now
1390     been removed.
1391    
1392     34. Added a number of extra features that are going to be in Perl 5.10. On the
1393     whole, these are just syntactic alternatives for features that PCRE had
1394     previously implemented using the Python syntax or my own invention. The
1395     other formats are all retained for compatibility.
1396    
1397     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1398     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1399     also .NET compatible.
1400    
1401     (b) A recursion or subroutine call to a named group can now be defined as
1402     (?&name) as well as (?P>name).
1403    
1404     (c) A backreference to a named group can now be defined as \k<name> or
1405     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1406     5.10, are also .NET compatible.
1407    
1408     (d) A conditional reference to a named group can now use the syntax
1409     (?(<name>) or (?('name') as well as (?(name).
1410    
1411     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1412     groups (named and numbered) that are never evaluated inline, but can be
1413     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1414     is always false. There may be only one alternative in such a group.
1415    
1416     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1417     as the simple (?(R). The condition is true only if the most recent
1418     recursion is that of the given number or name. It does not search out
1419     through the entire recursion stack.
1420    
1421     (g) The escape \gN or \g{N} has been added, where N is a positive or
1422     negative number, specifying an absolute or relative reference.
1423    
1424     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1425     some "unreachable code" warnings.
1426    
1427     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1428     things, this adds five new scripts.
1429    
1430     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1431     There were also incompatibilities regarding the handling of \Q..\E inside
1432     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1433     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1434    
1435     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1436     matches an empty string, and forcibly breaks the loop. There were bugs in
1437     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1438     against aaaa the result was just "a" rather than "aaaa", for example. Two
1439     separate and independent bugs (that affected different cases) have been
1440     fixed.
1441    
1442     39. Refactored the code to abolish the use of different opcodes for small
1443     capturing bracket numbers. This is a tidy that I avoided doing when I
1444     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1445     The new approach is not only tidier, it makes it possible to reduce the
1446     memory needed to fix the previous bug (38).
1447    
1448     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1449     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1450     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1451     mode.
1452    
1453     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1454     report.
1455    
1456     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1457     copy construction and assignment in the C++ wrapper.
1458    
1459     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1460     couple of bugs that could have given wrong results in the "--newline=crlf"
1461     case.
1462    
1463     44. Added a number of casts and did some reorganization of signed/unsigned int
1464     variables following suggestions from Dair Grant. Also renamed the variable
1465     "this" as "item" because it is a C++ keyword.
1466    
1467     45. Arranged for dftables to add
1468    
1469     #include "pcre_internal.h"
1470    
1471     to pcre_chartables.c because without it, gcc 4.x may remove the array
1472     definition from the final binary if PCRE is built into a static library and
1473     dead code stripping is activated.
1474    
1475     46. For an unanchored pattern, if a match attempt fails at the start of a
1476     newline sequence, and the newline setting is CRLF or ANY, and the next two
1477     characters are CRLF, advance by two characters instead of one.
1478    
1479    
1480 nigel 91 Version 6.7 04-Jul-06
1481     ---------------------
1482    
1483     1. In order to handle tests when input lines are enormously long, pcretest has
1484     been re-factored so that it automatically extends its buffers when
1485     necessary. The code is crude, but this _is_ just a test program. The
1486     default size has been increased from 32K to 50K.
1487    
1488     2. The code in pcre_study() was using the value of the re argument before
1489     testing it for NULL. (Of course, in any sensible call of the function, it
1490     won't be NULL.)
1491    
1492     3. The memmove() emulation function in pcre_internal.h, which is used on
1493     systems that lack both memmove() and bcopy() - that is, hardly ever -
1494     was missing a "static" storage class specifier.
1495    
1496     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1497     containing an extended class (one that cannot be represented by a bitmap
1498     because it contains high-valued characters or Unicode property items, e.g.
1499     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1500     pattern, but PCRE should not loop if you do not (it no longer does).
1501     [Detail: two cases were found: (a) a repeated subpattern containing an
1502     extended class; (b) a recursive reference to a subpattern that followed a
1503     previous extended class. It wasn't skipping over the extended class
1504     correctly when UTF-8 mode was not set.]
1505    
1506     5. A negated single-character class was not being recognized as fixed-length
1507     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1508     compile error "lookbehind assertion is not fixed length".
1509    
1510     6. The RunPerlTest auxiliary script was showing an unexpected difference
1511     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1512     write a Perl script that can interpret lines of an input file either as
1513     byte characters or as UTF-8, which is what "perltest" was being required to
1514     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1515     can't do is switch easily at run time between having the "use utf8;" pragma
1516     or not. In the end, I fudged it by using the RunPerlTest script to insert
1517     "use utf8;" explicitly for the UTF-8 tests.
1518    
1519     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1520     the end of the subject string, contrary to the documentation and to what
1521     Perl does. This was true of both matching functions. Now it matches only at
1522     the start of the subject and immediately after *internal* newlines.
1523    
1524     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1525     a pointer to an int instead of a pointer to an unsigned long int. This
1526     caused problems on 64-bit systems.
1527    
1528     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1529     instance of the 'standard' template library not being so standard".
1530    
1531     10. There was no check on the number of named subpatterns nor the maximum
1532     length of a subpattern name. The product of these values is used to compute
1533     the size of the memory block for a compiled pattern. By supplying a very
1534     long subpattern name and a large number of named subpatterns, the size
1535     computation could be caused to overflow. This is now prevented by limiting
1536     the length of names to 32 characters, and the number of named subpatterns
1537     to 10,000.
1538    
1539     11. Subpatterns that are repeated with specific counts have to be replicated in
1540     the compiled pattern. The size of memory for this was computed from the
1541     length of the subpattern and the repeat count. The latter is limited to
1542     65535, but there was no limit on the former, meaning that integer overflow
1543     could in principle occur. The compiled length of a repeated subpattern is
1544     now limited to 30,000 bytes in order to prevent this.
1545    
1546     12. Added the optional facility to have named substrings with the same name.
1547    
1548     13. Added the ability to use a named substring as a condition, using the
1549     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1550     are numbers (not recommended). Forward references are permitted.
1551    
1552     14. Added forward references in named backreferences (if you see what I mean).
1553    
1554     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1555     pattern could run off the end of the subject. For example, the pattern
1556     "(?s)(.{1,5})"8 did this with the subject "ab".
1557    
1558     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1559     PCRE_CASELESS was set when matching characters that were quantified with ?
1560     or *.
1561    
1562     17. A character class other than a single negated character that had a minimum
1563     but no maximum quantifier - for example [ab]{6,} - was not handled
1564     correctly by pce_dfa_exec(). It would match only one character.
1565    
1566     18. A valid (though odd) pattern that looked like a POSIX character
1567     class but used an invalid character after [ (for example [[,abc,]]) caused
1568     pcre_compile() to give the error "Failed: internal error: code overflow" or
1569     in some cases to crash with a glibc free() error. This could even happen if
1570     the pattern terminated after [[ but there just happened to be a sequence of
1571     letters, a binary zero, and a closing ] in the memory that followed.
1572    
1573     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1574     over the years. Originally (before any Unicode support), just the bottom 8
1575     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1576     output from "man perlunicode" includes this:
1577    
1578     The regular expression compiler produces polymorphic opcodes. That
1579     is, the pattern adapts to the data and automatically switches to
1580     the Unicode character scheme when presented with Unicode data--or
1581     instead uses a traditional byte scheme when presented with byte
1582     data.
1583    
1584     Sadly, a wide octal escape does not cause a switch, and in a string with
1585     no other multibyte characters, these octal escapes are treated as before.
1586     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1587     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1588     Unicode string.
1589    
1590     I have not perpetrated such confusion in PCRE. Up till now, it took just
1591     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1592     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1593     translate to the appropriate multibyte character.
1594    
1595     29. Applied some refactoring to reduce the number of warnings from Microsoft
1596     and Borland compilers. This has included removing the fudge introduced
1597     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1598     a warning about an unused variable.
1599    
1600     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1601     characters since release 4.0, because Perl (from release 5.004) does not.
1602     [Or at least, is documented not to: some releases seem to be in conflict
1603     with the documentation.] However, when a pattern was studied with
1604     pcre_study() and all its branches started with \s, PCRE still included VT
1605     as a possible starting character. Of course, this did no harm; it just
1606     caused an unnecessary match attempt.
1607    
1608     22. Removed a now-redundant internal flag bit that recorded the fact that case
1609     dependency changed within the pattern. This was once needed for "required
1610     byte" processing, but is no longer used. This recovers a now-scarce options
1611     bit. Also moved the least significant internal flag bit to the most-
1612     significant bit of the word, which was not previously used (hangover from
1613     the days when it was an int rather than a uint) to free up another bit for
1614     the future.
1615    
1616     23. Added support for CRLF line endings as well as CR and LF. As well as the
1617     default being selectable at build time, it can now be changed at runtime
1618     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1619     specify that it is scanning data with non-default line endings.
1620    
1621     24. Changed the definition of CXXLINK to make it agree with the definition of
1622     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1623    
1624     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1625     recursions. This makes a big different to stack usage for some patterns.
1626    
1627     26. If a subpattern containing a named recursion or subroutine reference such
1628     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1629     the space required for the compiled pattern went wrong and gave too small a
1630     value. Depending on the environment, this could lead to "Failed: internal
1631     error: code overflow at offset 49" or "glibc detected double free or
1632     corruption" errors.
1633    
1634     27. Applied patches from Google (a) to support the new newline modes and (b) to
1635     advance over multibyte UTF-8 characters in GlobalReplace.
1636    
1637     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1638     difference for some implementation of PCRE in some Windows version.
1639    
1640     29. Added some extra testing facilities to pcretest:
1641    
1642     \q<number> in a data line sets the "match limit" value
1643     \Q<number> in a data line sets the "match recursion limt" value
1644     -S <number> sets the stack size, where <number> is in megabytes
1645    
1646     The -S option isn't available for Windows.
1647    
1648    
1649 nigel 89 Version 6.6 06-Feb-06
1650     ---------------------
1651    
1652     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1653     in pcreposix.h. I have copied the definition from pcre.h.
1654    
1655     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1656     because pcre.h is no longer a built file.
1657    
1658     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1659     not normally included in the compiled code.
1660    
1661    
1662 nigel 87 Version 6.5 01-Feb-06
1663     ---------------------
1664    
1665     1. When using the partial match feature with pcre_dfa_exec(), it was not
1666     anchoring the second and subsequent partial matches at the new starting
1667     point. This could lead to incorrect results. For example, with the pattern
1668     /1234/, partially matching against "123" and then "a4" gave a match.
1669    
1670     2. Changes to pcregrep:
1671    
1672     (a) All non-match returns from pcre_exec() were being treated as failures
1673     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1674     error message is output. Some extra information is given for the
1675     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1676     probably the only errors that are likely to be caused by users (by
1677     specifying a regex that has nested indefinite repeats, for instance).
1678     If there are more than 20 of these errors, pcregrep is abandoned.
1679    
1680     (b) A binary zero was treated as data while matching, but terminated the
1681     output line if it was written out. This has been fixed: binary zeroes
1682     are now no different to any other data bytes.
1683    
1684     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1685     used to set a locale for matching. The --locale=xxxx long option has
1686     been added (no short equivalent) to specify a locale explicitly on the
1687     pcregrep command, overriding the environment variables.
1688    
1689     (d) When -B was used with -n, some line numbers in the output were one less
1690     than they should have been.
1691    
1692     (e) Added the -o (--only-matching) option.
1693    
1694     (f) If -A or -C was used with -c (count only), some lines of context were
1695     accidentally printed for the final match.
1696    
1697     (g) Added the -H (--with-filename) option.
1698    
1699     (h) The combination of options -rh failed to suppress file names for files
1700     that were found from directory arguments.
1701    
1702     (i) Added the -D (--devices) and -d (--directories) options.
1703    
1704     (j) Added the -F (--fixed-strings) option.
1705    
1706     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1707    
1708     (l) Added the --colo(u)r option.
1709    
1710     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1711     is not present by default.
1712    
1713     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1714     items such as (?R) or (?1), when the recursion could match a number of
1715     alternatives. If it matched one of the alternatives, but subsequently,
1716     outside the recursion, there was a failure, the code tried to back up into
1717     the recursion. However, because of the way PCRE is implemented, this is not
1718     possible, and the result was an incorrect result from the match.
1719    
1720     In order to prevent this happening, the specification of recursion has
1721     been changed so that all such subpatterns are automatically treated as
1722     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1723    
1724     4. I had overlooked the fact that, in some locales, there are characters for
1725     which isalpha() is true but neither isupper() nor islower() are true. In
1726     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1727     and ordfeminine) are like this. This affected the treatment of \w and \W
1728     when they appeared in character classes, but not when they appeared outside
1729     a character class. The bit map for "word" characters is now created
1730     separately from the results of isalnum() instead of just taking it from the
1731     upper, lower, and digit maps. (Plus the underscore character, of course.)
1732    
1733     5. The above bug also affected the handling of POSIX character classes such as
1734     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1735     permanent tables. Instead, the bit maps for such a class were previously
1736     created as the appropriate unions of the upper, lower, and digit bitmaps.
1737     Now they are created by subtraction from the [[:word:]] class, which has
1738     its own bitmap.
1739    
1740     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1741     It is created by subtracting the vertical space characters (\x09, \x0a,
1742     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1743     subtraction was done in the overall bitmap for a character class, meaning
1744     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1745     be recognized. This bug has been fixed.
1746    
1747     7. Patches from the folks at Google:
1748    
1749     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1750     real life, but is still worth protecting against".
1751    
1752     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1753     regular expressions".
1754    
1755     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1756     have it.
1757    
1758     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1759     "configure" and the latter not, in order to fix a problem somebody had
1760     with compiling the Arg class on HP-UX.
1761    
1762     (e) Improve the error-handling of the C++ wrapper a little bit.
1763    
1764     (f) New tests for checking recursion limiting.
1765    
1766     8. The pcre_memmove() function, which is used only if the environment does not
1767     have a standard memmove() function (and is therefore rarely compiled),
1768     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1769     returning a result (though PCRE never actually uses the result).
1770    
1771     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1772     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1773     returned instead of calling malloc() with an overflowing number that would
1774     most likely cause subsequent chaos.
1775    
1776     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1777    
1778     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1779     with this option is matched, the nmatch and pmatch options of regexec() are
1780     ignored.
1781    
1782     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1783     provided in case anyone wants to the the POSIX interface with UTF-8
1784     strings.
1785    
1786     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1787     C++ linking (needed for some HP-UX environments).
1788    
1789     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1790     (unused parameter) and in the pcre_printint() function (omitted "default"
1791     switch label when the default is to do nothing).
1792    
1793     15. Added some code to make it possible, when PCRE is compiled as a C++
1794     library, to replace subject pointers for pcre_exec() with a smart pointer
1795     class, thus making it possible to process discontinuous strings.
1796    
1797     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1798     much the same function. They were added by different people who were trying
1799     to make PCRE easy to compile on non-Unix systems. It has been suggested
1800     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1801     for compiling on Windows systems. I have therefore replaced it with
1802     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1803     defaults to "extern" for C or "extern C" for C++, which works fine on
1804     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1805     SCOPE with something explicit in config.h. In addition:
1806    
1807     (a) pcreposix.h still had just "extern" instead of either of these macros;
1808     I have replaced it with PCRE_DATA_SCOPE.
1809    
1810     (b) Functions such as _pcre_xclass(), which are internal to the library,
1811     but external in the C sense, all had PCRE_EXPORT in their definitions.
1812     This is apparently wrong for the Windows case, so I have removed it.
1813     (It makes no difference on Unix-like systems.)
1814    
1815     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1816     of recursive calls to match(). This is different to MATCH_LIMIT because
1817     that limits the total number of calls to match(), not all of which increase
1818     the depth of recursion. Limiting the recursion depth limits the amount of
1819     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1820     when PCRE is compiled, and changed at run time. A patch from Google adds
1821     this functionality to the C++ interface.
1822    
1823     18. Changes to the handling of Unicode character properties:
1824    
1825     (a) Updated the table to Unicode 4.1.0.
1826    
1827     (b) Recognize characters that are not in the table as "Cn" (undefined).
1828    
1829     (c) I revised the way the table is implemented to a much improved format
1830     which includes recognition of ranges. It now supports the ranges that
1831     are defined in UnicodeData.txt, and it also amalgamates other
1832     characters into ranges. This has reduced the number of entries in the
1833     table from around 16,000 to around 3,000, thus reducing its size
1834     considerably. I realized I did not need to use a tree structure after
1835     all - a binary chop search is just as efficient. Having reduced the
1836     number of entries, I extended their size from 6 bytes to 8 bytes to
1837     allow for more data.
1838    
1839     (d) Added support for Unicode script names via properties such as \p{Han}.
1840    
1841     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1842     matching that character.
1843    
1844     20. When matching a repeated Unicode property with a minimum greater than zero,
1845     (for example \pL{2,}), PCRE could look past the end of the subject if it
1846     reached it while seeking the minimum number of characters. This could
1847     happen only if some of the characters were more than one byte long, because
1848     there is a check for at least the minimum number of bytes.
1849    
1850     21. Refactored the implementation of \p and \P so as to be more general, to
1851     allow for more different types of property in future. This has changed the
1852     compiled form incompatibly. Anybody with saved compiled patterns that use
1853     \p or \P will have to recompile them.
1854    
1855     22. Added "Any" and "L&" to the supported property types.
1856    
1857     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1858     but give a compile time error if the value is greater than 0xff.
1859    
1860     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1861     accidentally not being installed or uninstalled.
1862    
1863     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1864     made were to insert the current release number. This seemed silly, because
1865     it made things harder for people building PCRE on systems that don't run
1866     "configure". I have turned pcre.h into a distributed file, no longer built
1867     by "configure", with the version identification directly included. There is
1868     no longer a pcre.h.in file.
1869    
1870     However, this change necessitated a change to the pcre-config script as
1871     well. It is built from pcre-config.in, and one of the substitutions was the
1872     release number. I have updated configure.ac so that ./configure now finds
1873     the release number by grepping pcre.h.
1874    
1875     26. Added the ability to run the tests under valgrind.
1876    
1877    
1878 nigel 85 Version 6.4 05-Sep-05
1879     ---------------------
1880    
1881     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1882     "--" to be printed when multiple files were scanned, even when none of the
1883     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1884     consider it to be a bug, and have restored the previous behaviour.
1885    
1886     2. A couple of code tidies to get rid of compiler warnings.
1887    
1888     3. The pcretest program used to cheat by referring to symbols in the library
1889     whose names begin with _pcre_. These are internal symbols that are not
1890     really supposed to be visible externally, and in some environments it is
1891     possible to suppress them. The cheating is now confined to including
1892     certain files from the library's source, which is a bit cleaner.
1893    
1894     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1895     file's purpose clearer.
1896    
1897     5. Reorganized pcre_ucp_findchar().
1898    
1899    
1900 nigel 83 Version 6.3 15-Aug-05
1901     ---------------------
1902    
1903     1. The file libpcre.pc.in did not have general read permission in the tarball.
1904    
1905     2. There were some problems when building without C++ support:
1906    
1907     (a) If C++ support was not built, "make install" and "make test" still
1908     tried to test it.
1909    
1910     (b) There were problems when the value of CXX was explicitly set. Some
1911     changes have been made to try to fix these, and ...
1912    
1913     (c) --disable-cpp can now be used to explicitly disable C++ support.
1914    
1915     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1916     backslash in a target when C++ was disabled. This confuses some
1917     versions of "make", apparently. Using an intermediate variable solves
1918     this. (Same for CPP_LOBJ.)
1919    
1920     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1921     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1922     necessary on certain architectures.
1923    
1924     4. Added a setting of -export-symbols-regex to the link command to remove
1925     those symbols that are exported in the C sense, but actually are local
1926     within the library, and not documented. Their names all begin with
1927     "_pcre_". This is not a perfect job, because (a) we have to except some
1928     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1929     available (and never for static libraries). I have made a note to try to
1930     find a way round (a) in the future.
1931    
1932    
1933 nigel 81 Version 6.2 01-Aug-05
1934     ---------------------
1935    
1936     1. There was no test for integer overflow of quantifier values. A construction
1937     such as {1111111111111111} would give undefined results. What is worse, if
1938     a minimum quantifier for a parenthesized subpattern overflowed and became
1939     negative, the calculation of the memory size went wrong. This could have
1940     led to memory overwriting.
1941    
1942     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1943    
1944     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1945     operating environments where this matters.
1946    
1947     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1948     PCRE options from within the C++ wrapper.
1949    
1950     5. Named capturing subpatterns were not being correctly counted when a pattern
1951     was compiled. This caused two problems: (a) If there were more than 100
1952     such subpatterns, the calculation of the memory needed for the whole
1953     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1954     back references of the form \12, where the number was greater than 9, were
1955     not recognized as back references, even though there were sufficient
1956     previous subpatterns.
1957    
1958     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1959     versions of gcc, e.g. 2.95.4.
1960    
1961    
1962 nigel 79 Version 6.1 21-Jun-05
1963     ---------------------
1964    
1965     1. There was one reference to the variable "posix" in pcretest.c that was not
1966     surrounded by "#if !defined NOPOSIX".
1967    
1968     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1969     the cross-check on the old pcre_info() function, for the benefit of the
1970     cut-down version of PCRE that is currently imported into Exim.
1971    
1972     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1973     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1974     patterns that start (?i) but I don't think that matters. The use of (?i) is
1975     just an example; this all applies to the other options as well.
1976    
1977     4. Since libtool seems to echo the compile commands it is issuing, the output
1978     from "make" can be reduced a bit by putting "@" in front of each libtool
1979     compile command.
1980    
1981     5. Patch from the folks at Google for configure.in to be a bit more thorough
1982     in checking for a suitable C++ installation before trying to compile the
1983     C++ stuff. This should fix a reported problem when a compiler was present,
1984     but no suitable headers.
1985    
1986     6. The man pages all had just "PCRE" as their title. I have changed them to
1987     be the relevant file name. I have also arranged that these names are
1988     retained in the file doc/pcre.txt, which is a concatenation in text format
1989     of all the man pages except the little individual ones for each function.
1990    
1991     7. The NON-UNIX-USE file had not been updated for the different set of source
1992     files that come with release 6. I also added a few comments about the C++
1993     wrapper.
1994    
1995    
1996 nigel 77 Version 6.0 07-Jun-05
1997     ---------------------
1998    
1999     1. Some minor internal re-organization to help with my DFA experiments.
2000    
2001     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2002     didn't matter for the library itself when fully configured, but did matter
2003     when compiling without UCP support, or within Exim, where the ucp files are
2004     not imported.
2005    
2006     3. Refactoring of the library code to split up the various functions into
2007     different source modules. The addition of the new DFA matching code (see
2008     below) to a single monolithic source would have made it really too
2009     unwieldy, quite apart from causing all the code to be include in a
2010     statically linked application, when only some functions are used. This is
2011     relevant even without the DFA addition now that patterns can be compiled in
2012     one application and matched in another.
2013    
2014     The downside of splitting up is that there have to be some external
2015     functions and data tables that are used internally in different modules of
2016     the library but which are not part of the API. These have all had their
2017     names changed to start with "_pcre_" so that they are unlikely to clash
2018     with other external names.
2019    
2020     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2021     a different (DFA) algorithm. Although it is slower than the original
2022     function, it does have some advantages for certain types of matching
2023     problem.
2024    
2025     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2026     including restarting after a partial match.
2027    
2028     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2029     defined when compiling for Windows was sent to me. I have put it into the
2030     code, though I have no means of testing or verifying it.
2031    
2032     7. Added the pcre_refcount() auxiliary function.
2033    
2034     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2035     match before or at the first newline in the subject string. In pcretest,
2036     the /f option on a pattern can be used to set this.
2037    
2038     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2039     would behave wrongly. This has been present in PCRE since release 4.0.
2040    
2041     10. A number of changes to the pcregrep command:
2042    
2043     (a) Refactored how -x works; insert ^(...)$ instead of setting
2044     PCRE_ANCHORED and checking the length, in preparation for adding
2045     something similar for -w.
2046    
2047     (b) Added the -w (match as a word) option.
2048    
2049     (c) Refactored the way lines are read and buffered so as to have more
2050     than one at a time available.
2051    
2052     (d) Implemented a pcregrep test script.
2053    
2054     (e) Added the -M (multiline match) option. This allows patterns to match
2055     over several lines of the subject. The buffering ensures that at least
2056     8K, or the rest of the document (whichever is the shorter) is available
2057     for matching (and similarly the previous 8K for lookbehind assertions).
2058    
2059     (f) Changed the --help output so that it now says
2060    
2061     -w, --word-regex(p)
2062    
2063     instead of two lines, one with "regex" and the other with "regexp"
2064     because that confused at least one person since the short forms are the
2065     same. (This required a bit of code, as the output is generated
2066     automatically from a table. It wasn't just a text change.)
2067    
2068     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2069     option but starts with a hyphen. Could be a pattern or a path name
2070     starting with a hyphen, for instance.
2071    
2072     (h) "-" can be given as a file name to represent stdin.
2073    
2074     (i) When file names are being printed, "(standard input)" is used for
2075     the standard input, for compatibility with GNU grep. Previously
2076     "<stdin>" was used.
2077    
2078     (j) The option --label=xxx can be used to supply a name to be used for
2079     stdin when file names are being printed. There is no short form.
2080    
2081     (k) Re-factored the options decoding logic because we are going to add
2082     two more options that take data. Such options can now be given in four
2083     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2084    
2085     (l) Added the -A, -B, and -C options for requesting that lines of context
2086     around matches be printed.
2087    
2088     (m) Added the -L option to print the names of files that do not contain
2089     any matching lines, that is, the complement of -l.
2090    
2091     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2092     continue to scan other files.
2093    
2094     (o) The -s option was incorrectly implemented. For compatibility with other
2095     greps, it now suppresses the error message for a non-existent or non-
2096     accessible file (but not the return code). There is a new option called
2097     -q that suppresses the output of matching lines, which was what -s was
2098     previously doing.
2099    
2100     (p) Added --include and --exclude options to specify files for inclusion
2101     and exclusion when recursing.
2102    
2103     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2104     Hopefully, it now does.
2105    
2106     12. Missing cast in pcre_study().
2107    
2108     13. Added an "uninstall" target to the makefile.
2109    
2110     14. Replaced "extern" in the function prototypes in Makefile.in with
2111     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2112     world, but is set differently for Windows.
2113    
2114     15. Added a second compiling function called pcre_compile2(). The only
2115     difference is that it has an extra argument, which is a pointer to an
2116     integer error code. When there is a compile-time failure, this is set
2117     non-zero, in addition to the error test pointer being set to point to an
2118     error message. The new argument may be NULL if no error number is required
2119     (but then you may as well call pcre_compile(), which is now just a
2120     wrapper). This facility is provided because some applications need a
2121     numeric error indication, but it has also enabled me to tidy up the way
2122     compile-time errors are handled in the POSIX wrapper.
2123    
2124     16. Added VPATH=.libs to the makefile; this should help when building with one
2125     prefix path and installing with another. (Or so I'm told by someone who
2126     knows more about this stuff than I do.)
2127    
2128     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2129     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2130     match everything, including newlines. This is not POSIX-compatible, but
2131     somebody wanted the feature. From pcretest it can be activated by using
2132     both the P and the s flags.
2133    
2134     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2135    
2136     19. libpcre.pc was being incorrectly installed as executable.
2137    
2138     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2139     it now also looks for '\r' so that it will work unmodified on Windows.
2140    
2141     21. Added Google's contributed C++ wrapper to the distribution.
2142    
2143     22. Added some untidy missing memory free() calls in pcretest, to keep
2144     Electric Fence happy when testing.
2145    
2146    
2147    
2148 nigel 75 Version 5.0 13-Sep-04
2149     ---------------------
2150    
2151     1. Internal change: literal characters are no longer packed up into items
2152     containing multiple characters in a single byte-string. Each character
2153     is now matched using a separate opcode. However, there may be more than one
2154     byte in the character in UTF-8 mode.
2155    
2156     2. The pcre_callout_block structure has two new fields: pattern_position and
2157     next_item_length. These contain the offset in the pattern to the next match
2158     item, and its length, respectively.
2159    
2160     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2161     insertion of callouts before each pattern item. Added the /C option to
2162     pcretest to make use of this.
2163    
2164     4. On the advice of a Windows user, the lines
2165    
2166     #if defined(_WIN32) || defined(WIN32)
2167     _setmode( _fileno( stdout ), 0x8000 );
2168     #endif /* defined(_WIN32) || defined(WIN32) */
2169    
2170     have been added to the source of pcretest. This apparently does useful
2171     magic in relation to line terminators.
2172    
2173     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2174     for the benefit of those environments where the "b" makes a difference.
2175    
2176     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2177     to know about it. I have put a hack into configure.in that adds in code
2178     to set GCC=yes if CC=icc. This seems to end up at a point in the
2179     generated configure script that is early enough to affect the setting of
2180     compiler options, which is what is needed, but I have no means of testing
2181     whether it really works. (The user who reported this had patched the
2182     generated configure script, which of course I cannot do.)
2183    
2184     LATER: After change 22 below (new libtool files), the configure script
2185     seems to know about icc (and also ecc). Therefore, I have commented out
2186     this hack in configure.in.
2187    
2188     7. Added support for pkg-config (2 patches were sent in).
2189    
2190     8. Negated POSIX character classes that used a combination of internal tables
2191     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2192     [[:^ascii]]. Typically, they would match almost any characters. The other
2193     POSIX classes were not broken in this way.
2194    
2195     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2196     to find the match, as PCRE was deluded into thinking that the match had to
2197     start at the start point or following a newline. The same bug applied to
2198     patterns with negative forward assertions or any backward assertions
2199     preceding ".*" at the start, unless the pattern required a fixed first
2200     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2201    
2202     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2203     starting at the last subject character, bytes beyond the end of the subject
2204     string were read.
2205    
2206     11. Renamed the variable "class" as "classbits" to make life easier for C++
2207     users. (Previously there was a macro definition, but it apparently wasn't
2208     enough.)
2209    
2210     12. Added the new field "tables" to the extra data so that tables can be passed
2211     in at exec time, or the internal tables can be re-selected. This allows
2212     a compiled regex to be saved and re-used at a later time by a different
2213     program that might have everything at different addresses.
2214    
2215     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2216     -R library as well as a -L library.
2217    
2218     14. The debugging options of pcretest (-d on the command line or D on a
2219     pattern) showed incorrect output for anything following an extended class
2220     that contained multibyte characters and which was followed by a quantifier.
2221    
2222     15. Added optional support for general category Unicode character properties
2223     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2224     support. It adds about 90K to the size of the library. The meanings of the
2225     inbuilt class escapes such as \d and \s have NOT been changed.
2226    
2227     16. Updated pcredemo.c to include calls to free() to release the memory for the
2228     compiled pattern.
2229    
2230     17. The generated file chartables.c was being created in the source directory
2231     instead of in the building directory. This caused the build to fail if the
2232     source directory was different from the building directory, and was
2233     read-only.
2234    
2235     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2236     file. No doubt somebody will tell me if they don't make sense... Also added
2237     Dan Mooney's comments about building on OpenVMS.
2238    
2239     19. Added support for partial matching via the PCRE_PARTIAL option for
2240     pcre_exec() and the \P data escape in pcretest.
2241    
2242     20. Extended pcretest with 3 new pattern features:
2243    
2244     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2245     write the compiled pattern to the file whose name is "rest-of-line".
2246     This is a straight binary dump of the data, with the saved pointer to
2247     the character tables forced to be NULL. The study data, if any, is
2248     written too. After writing, pcretest reads a new pattern.
2249    
2250     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2251     compiled pattern from the given file. There must not be any
2252     occurrences of "<" in the file name (pretty unlikely); if there are,
2253     pcretest will instead treat the initial "<" as a pattern delimiter.
2254     After reading in the pattern, pcretest goes on to read data lines as
2255     usual.
2256    
2257     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2258     and 16-bit fields in a compiled pattern, to simulate a pattern that
2259     was compiled on a host of opposite endianness.
2260    
2261     21. The pcre-exec() function can now cope with patterns that were compiled on
2262     hosts of opposite endianness, with this restriction:
2263    
2264     As for any compiled expression that is saved and used later, the tables
2265     pointer field cannot be preserved; the extra_data field in the arguments
2266     to pcre_exec() should be used to pass in a tables address if a value
2267     other than the default internal tables were used at compile time.
2268    
2269     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2270     now diagnosed as an error. Previously, most of the time, a negative number
2271     would have been treated as zero, but if in addition "ovector" was passed as
2272     NULL, a crash could occur.
2273    
2274     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2275     new versions from the libtool 1.5 distribution (the last one is a copy of
2276     a file called libtool.m4). This seems to have fixed the need to patch
2277     "configure" to support Darwin 1.3 (which I used to do). However, I still
2278     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2279     workstation).
2280    
2281     24. Changed the PCRE licence to be the more standard "BSD" licence.
2282    
2283    
2284 nigel 73 Version 4.5 01-Dec-03
2285     ---------------------
2286    
2287     1. There has been some re-arrangement of the code for the match() function so
2288     that it can be compiled in a version that does not call itself recursively.
2289     Instead, it keeps those local variables that need separate instances for
2290     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2291     needs to "recurse". Keeping track of where control must go is done by means
2292     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2293     hide most of the details from the main code, and operates only if
2294     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2295     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2296     operating.
2297    
2298     To make it easier for callers to provide specially tailored get/free
2299     functions for this usage, two new functions, pcre_stack_malloc, and
2300     pcre_stack_free, are used. They are always called in strict stacking order,
2301     and the size of block requested is always the same.
2302    
2303     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2304     PCRE has been compiled to use the stack or the heap for recursion. The
2305     -C option of pcretest uses this to show which version is compiled.
2306    
2307     A new data escape \S, is added to pcretest; it causes the amounts of store
2308     obtained and freed by both kinds of malloc/free at match time to be added
2309     to the output.
2310    
2311     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2312     what's available on my current Linux desktop machine.
2313    
2314     3. When matching a UTF-8 string, the test for a valid string at the start has
2315     been extended. If start_offset is not zero, PCRE now checks that it points
2316     to a byte that is the start of a UTF-8 character. If not, it returns
2317     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2318     this is necessary because there may be backward assertions in the pattern.
2319     When matching the same subject several times, it may save resources to use
2320     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2321    
2322     4. The code for checking the validity of UTF-8 strings has been tightened so
2323     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2324     containing "overlong sequences".
2325    
2326     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2327     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2328     should have been "&", but it just so happened that all the cases this let
2329     through by mistake were picked up later in the function.
2330    
2331     6. I had used a variable called "isblank" - this is a C99 function, causing
2332     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2333    
2334     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2335     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2336     so the version is shown; (c) stop "make test" echoing "./RunTest".
2337    
2338     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2339    
2340     9. The prototype for memmove() for systems that don't have it was using
2341     size_t, but the inclusion of the header that defines size_t was later. I've
2342     moved the #includes for the C headers earlier to avoid this.
2343    
2344     10. Added some adjustments to the code to make it easier to compiler on certain
2345     special systems:
2346    
2347     (a) Some "const" qualifiers were missing.
2348     (b) Added the macro EXPORT before all exported functions; by default this
2349     is defined to be empty.
2350     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2351     that it reads its output file name as an argument instead of writing
2352     to the standard output and assuming this can be redirected.
2353    
2354     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2355     class containing characters with values greater than 255, PCRE compilation
2356     went into a loop.
2357    
2358     12. A recursive reference to a subpattern that was within another subpattern
2359     that had a minimum quantifier of zero caused PCRE to crash. For example,
2360     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2361     recursion. If the recursively-called subpattern itself had a zero repeat,
2362     that was OK.
2363    
2364     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2365     buffer into which it was copied (for escape processing) was still set at
2366     1024, so long lines caused crashes.
2367    
2368     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2369     "internal error: code overflow...". This applied to any character class
2370     that was followed by a possessive quantifier.
2371    
2372     15. Modified the Makefile to add libpcre.la as a prerequisite for
2373     libpcreposix.la because I was told this is needed for a parallel build to
2374     work.
2375    
2376     16. If a pattern that contained .* following optional items at the start was
2377     studied, the wrong optimizing data was generated, leading to matching
2378     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2379     matching string must start with a or b or c. The correct conclusion for
2380     this pattern is that a match can start with any character.
2381    
2382    
2383 nigel 71 Version 4.4 13-Aug-03
2384     ---------------------
2385    
2386     1. In UTF-8 mode, a character class containing characters with values between
2387     127 and 255 was not handled correctly if the compiled pattern was studied.
2388     In fixing this, I have also improved the studying algorithm for such
2389     classes (slightly).
2390    
2391     2. Three internal functions had redundant arguments passed to them. Removal
2392     might give a very teeny performance improvement.
2393    
2394     3. Documentation bug: the value of the capture_top field in a callout is *one
2395     more than* the number of the hightest numbered captured substring.
2396    
2397     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2398     in incorrectly linking with a previously installed version. They now link
2399     explicitly with libpcre.la.
2400    
2401     5. configure.in no longer needs to recognize Cygwin specially.
2402    
2403     6. A problem in pcre.in for Windows platforms is fixed.
2404    
2405     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2406     pcretest, it used to include the size of the study block as part of its
2407     output. Unfortunately, the structure contains a field that has a different
2408     size on different hardware architectures. This meant that the tests that
2409     showed this size failed. As the block is currently always of a fixed size,
2410     this information isn't actually particularly useful in pcretest output, so
2411     I have just removed it.
2412    
2413     8. Three pre-processor statements accidentally did not start in column 1.
2414     Sadly, there are *still* compilers around that complain, even though
2415     standard C has not required this for well over a decade. Sigh.
2416    
2417     9. In pcretest, the code for checking callouts passed small integers in the
2418     callout_data field, which is a void * field. However, some picky compilers
2419     complained about the casts involved for this on 64-bit systems. Now
2420     pcretest passes the address of the small integer instead, which should get
2421     rid of the warnings.
2422    
2423     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2424     both compile and run time, and gives an error if an invalid UTF-8 sequence
2425     is found. There is a option for disabling this check in cases where the
2426     string is known to be correct and/or the maximum performance is wanted.
2427    
2428     11. In response to a bug report, I changed one line in Makefile.in from
2429    
2430     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2431     to
2432     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2433    
2434     to look similar to other lines, but I have no way of telling whether this
2435     is the right thing to do, as I do not use Windows. No doubt I'll get told
2436     if it's wrong...
2437    
2438    
2439 nigel 69 Version 4.3 21-May-03
2440     ---------------------
2441    
2442     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2443     Makefile.
2444    
2445     2. Some refactoring to improve the quality of the code:
2446    
2447     (i) The utf8_table... variables are now declared "const".
2448    
2449     (ii) The code for \cx, which used the "case flipping" table to upper case
2450     lower case letters, now just substracts 32. This is ASCII-specific,
2451     but the whole concept of \cx is ASCII-specific, so it seems
2452     reasonable.
2453    
2454     (iii) PCRE was using its character types table to recognize decimal and
2455     hexadecimal digits in the pattern. This is silly, because it handles
2456     only 0-9, a-f, and A-F, but the character types table is locale-
2457     specific, which means strange things might happen. A private
2458     table is now used for this - though it costs 256 bytes, a table is
2459     much faster than multiple explicit tests. Of course, the standard
2460     character types table is still used for matching digits in subject
2461     strings against \d.
2462    
2463     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2464     ending in _t are). So I've renamed it as ESC_tee.
2465    
2466     3. The first argument for regexec() in the POSIX wrapper should have been
2467     defined as "const".
2468    
2469     4. Changed pcretest to use malloc() for its buffers so that they can be
2470     Electric Fenced for debugging.
2471    
2472     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2473     to read one or more bytes before the start of the subject string. Often this
2474     had no effect on PCRE's behaviour, but in some circumstances it could
2475     provoke a segmentation fault.
2476    
2477     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2478     to try to read one or more bytes before the start of the subject string.
2479    
2480     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2481     UTF-8 support could misbehave in various ways if the subject string
2482     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2483     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2484     back over UTF-8 characters.)
2485    
2486    
2487 nigel 67 Version 4.2 14-Apr-03
2488     ---------------------
2489    
2490     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2491    
2492     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2493     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2494     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2495     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2496     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2497     and BUILD_EXEEXT
2498     Note: automatic setting of the BUILD variables is not yet working
2499     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2500     compile-time but not at link-time
2501     [LINK]: use for linking executables only
2502     make different versions for Windows and non-Windows
2503     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2504     libraries
2505     [LINK_FOR_BUILD]: new variable
2506     [OBJEXT]: use throughout
2507     [EXEEXT]: use throughout
2508     <winshared>: new target
2509     <wininstall>: new target
2510     <dftables.o>: use native compiler
2511     <dftables>: use native linker
2512     <install>: handle Windows platform correctly
2513     <clean>: ditto
2514     <check>: ditto
2515     copy DLL to top builddir before testing
2516    
2517     As part of these changes, -no-undefined was removed again. This was reported
2518     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2519     in any case.
2520    
2521     3. Some tidies to get rid of compiler warnings:
2522    
2523     . In the match_data structure, match_limit was an unsigned long int, whereas
2524     match_call_count was an int. I've made them both unsigned long ints.
2525    
2526     . In pcretest the fact that a const uschar * doesn't automatically cast to
2527     a void * provoked a warning.
2528    
2529     . Turning on some more compiler warnings threw up some "shadow" variables
2530     and a few more missing casts.
2531    
2532     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2533     option, a class that contained a single character with a value between 128
2534     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2535    
2536     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2537     option, a class that contained several characters, but with at least one
2538     whose value was between 128 and 255 caused PCRE to crash.
2539    
2540    
2541 nigel 65 Version 4.1 12-Mar-03
2542     ---------------------
2543 nigel 63
2544 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2545     needed, and a string in dftables.c that was longer than standard compilers are
2546     required to support.
2547    
2548     2. Compiling with Sun's compiler found a few more places where the code could
2549     be tidied up in order to avoid warnings.
2550    
2551     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2552     first of these names is deprecated in the latest Autoconf in favour of the name
2553     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2554     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2555     analogy I have changed it to CFLAGS_FOR_BUILD.
2556    
2557     4. Added -no-undefined to the linking command in the Makefile, because this is
2558     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2559     linking step for the pcreposix library.
2560    
2561     5. PCRE was failing to diagnose the case of two named groups with the same
2562     name.
2563    
2564     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2565     literal character that is needed in the subject for a match, and scans along to
2566     ensure that it is present before embarking on the full matching process. This
2567     saves time in cases of nested unlimited repeats that are never going to match.
2568     Problem: the scan can take a lot of time if the subject is very long (e.g.
2569     megabytes), thus penalizing straightforward matches. It is now done only if the
2570     amount of subject to be scanned is less than 1000 bytes.
2571    
2572     7. A lesser problem with the same optimization is that it was recording the
2573     first character of an anchored pattern as "needed", thus provoking a search
2574     right along the subject, even when the first match of the pattern was going to
2575     fail. The "needed" character is now not set for anchored patterns, unless it
2576     follows something in the pattern that is of non-fixed length. Thus, it still
2577     fulfils its original purpose of finding quick non-matches in cases of nested
2578     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2579    
2580    
2581     Version 4.0 17-Feb-03
2582     ---------------------
2583    
2584 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2585     extended to the end of string, PCRE compiled incorrect data. This could lead to
2586     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2587    
2588     2. Moved to autoconf 2.53 and libtool 1.4.2.
2589    
2590     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2591     the special perltest8 script is no longer needed - all the tests can be run
2592     from a single perltest script.
2593    
2594     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2595     by \s. It has now been removed in PCRE. This means it isn't recognized as
2596     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2597     class [:space:] *does* include VT, thereby creating a mess.
2598    
2599     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2600     space and tab.
2601    
2602     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2603     its new features into the main test script, reducing the number of scripts.
2604    
2605     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2606     were backward compatible, and made the (?i) apply to the whole pattern, as if
2607     /i were given. Now it behaves more logically, and applies the option setting
2608     only to what follows. PCRE has been changed to follow suit. However, if it
2609     finds options settings right at the start of the pattern, it extracts them into
2610     the global options, as before. Thus, they show up in the info data.
2611    
2612     8. Added support for the \Q...\E escape sequence. Characters in between are
2613     treated as literals. This is slightly different from Perl in that $ and @ are
2614     also handled as literals inside the quotes. In Perl, they will cause variable
2615     interpolation. Note the following examples:
2616    
2617     Pattern PCRE matches Perl matches
2618    
2619     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2620     \Qabc\$xyz\E abc\$xyz abc\$xyz
2621     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2622    
2623     For compatibility with Perl, \Q...\E sequences are recognized inside character
2624     classes as well as outside them.
2625    
2626     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2627     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2628     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2629     signed/unsigned warnings.
2630    
2631     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2632     option for pcretest, so I've replaced it by a simple function that does just
2633     that job.
2634    
2635     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2636     "pcregrep -".
2637    
2638     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2639     Java package. This provides some syntactic sugar for simple cases of what my
2640     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2641     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2642     item, you can use this simplified notation. Note that only makes sense with
2643     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2644     greediness, whatever the setting of the PCRE_UNGREEDY option.
2645    
2646     13. A change of greediness default within a pattern was not taking effect at
2647     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2648     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2649     was abstracted outside.
2650    
2651     14. PCRE now supports the \G assertion. It is true when the current matching
2652     position is at the start point of the match. This differs from \A when the
2653     starting offset is non-zero. Used with the /g option of pcretest (or similar
2654     code), it works in the same way as it does for Perl's /g option. If all
2655     alternatives of a regex begin with \G, the expression is anchored to the start
2656     match position, and the "anchored" flag is set in the compiled expression.
2657    
2658     15. Some bugs concerning the handling of certain option changes within patterns
2659     have been fixed. These applied to options other than (?ims). For example,
2660     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2661     been the other way round. Some of this was related to change 7 above.
2662    
2663     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2664     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2665     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2666     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2667    
2668     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2669     mode. Unlike ".", it always matches newline, whatever the setting of
2670     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2671     assertions. Perl allows it, but it doesn't (in general) work because it can't
2672     calculate the length of the lookbehind. At least, that's the case for Perl
2673     5.8.0 - I've been told they are going to document that it doesn't work in
2674     future.
2675    
2676     18. Added an error diagnosis for escapes that PCRE does not support: these are
2677     \L, \l, \N, \P, \p, \U, \u, and \X.
2678    
2679     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2680     reading past the end of the pattern in cases such as /[abcd/.
2681    
2682     20. PCRE was getting more memory than necessary for patterns with classes that
2683     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2684    
2685     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2686     compiling PCRE for use with Virtual Pascal.
2687    
2688     22. Small fix to the Makefile to make it work properly if the build is done
2689     outside the source tree.
2690    
2691     23. Added a new extension: a condition to go with recursion. If a conditional
2692     subpattern starts with (?(R) the "true" branch is used if recursion has
2693     happened, whereas the "false" branch is used only at the top level.
2694    
2695     24. When there was a very long string of literal characters (over 255 bytes
2696     without UTF support, over 250 bytes with UTF support), the computation of how
2697     much memory was required could be incorrect, leading to segfaults or other
2698     strange effects.
2699    
2700     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2701     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2702     there was a subsequent back reference to those brackets. This meant that, for
2703     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2704     possible to check for precisely this case. All we can do is abandon the
2705     optimization if .* occurs inside capturing brackets when there are any back
2706     references whatsoever. (See below for a better fix that came later.)
2707    
2708     26. The handling of the optimization for finding the first character of a
2709     non-anchored pattern, and for finding a character that is required later in the
2710     match were failing in some cases. This didn't break the matching; it just
2711     failed to optimize when it could. The way this is done has been re-implemented.
2712    
2713     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2714    
2715     28. Added a new feature that provides some of the functionality that Perl
2716     provides with (?{...}). The facility is termed a "callout". The way it is done
2717     in PCRE is for the caller to provide an optional function, by setting
2718     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2719     global variable. By default it is unset, which disables all calling out. To get
2720     the function called, the regex must include (?C) at appropriate points. This
2721     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2722     This provides a means of identifying different callout points. When PCRE
2723     reaches such a point in the regex, if pcre_callout has been set, the external
2724     function is called. It is provided with data in a structure called
2725     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2726     matching continues; if it returns a non-zero value, the match at the current
2727     point fails. However, backtracking will occur if possible. [This was changed
2728     later and other features added - see item 49 below.]
2729    
2730     29. pcretest is upgraded to test the callout functionality. It provides a
2731     callout function that displays information. By default, it shows the start of
2732     the match and the current position in the text. There are some new data escapes
2733     to vary what happens:
2734    
2735     \C+ in addition, show current contents of captured substrings
2736     \C- do not supply a callout function
2737     \C!n return 1 when callout number n is reached
2738     \C!n!m return 1 when callout number n is reached for the mth time
2739    
2740     30. If pcregrep was called with the -l option and just a single file name, it
2741     output "<stdin>" if a match was found, instead of the file name.
2742    
2743     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2744     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2745     pcre_exec(). This saves a malloc/free per call. The default value of
2746     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2747     when configuring.
2748    
2749     32. The default maximum size of a compiled pattern is 64K. There have been a
2750     few cases of people hitting this limit. The code now uses macros to handle the
2751     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2752     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2753     configuring. Tests 2 and 5 work only with 2-byte links because they output
2754     debugging information about compiled patterns.
2755    
2756     33. Internal code re-arrangements:
2757    
2758     (a) Moved the debugging function for printing out a compiled regex into
2759     its own source file (printint.c) and used #include to pull it into
2760     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2761     separate copies.
2762    
2763     (b) Defined the list of op-code names for debugging as a macro in
2764     internal.h so that it is next to the definition of the opcodes.
2765    
2766     (c) Defined a table of op-code lengths for simpler skipping along compiled
2767     code. This is again a macro in internal.h so that it is next to the
2768     definition of the opcodes.
2769    
2770     34. Added support for recursive calls to individual subpatterns, along the
2771     lines of Robin Houston's patch (but implemented somewhat differently).
2772    
2773     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2774     allow it to read and process whole directories in Win32. This code was
2775     contributed by Lionel Fourquaux; it has not been tested by me.
2776    
2777     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2778     used to name a group. Names consist of alphanumerics and underscores, and must
2779     be unique. Back references use the syntax (?P=name) and recursive calls use
2780     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2781     numbers. The function pcre_fullinfo() can be used after compilation to extract
2782     a name/number map. There are three relevant calls:
2783    
2784     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2785     PCRE_INFO_NAMECOUNT yields the number of entries
2786     PCRE_INFO_NAMETABLE yields a pointer to the map.
2787    
2788     The map is a vector of fixed-size entries. The size of each entry depends on
2789     the length of the longest name used. The first two bytes of each entry are the
2790     group number, most significant byte first. There follows the corresponding
2791     name, zero terminated. The names are in alphabetical order.
2792    
2793     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2794     case instead of 255. Making it the same both with and without UTF-8 support
2795     means that the same test output works with both.
2796    
2797     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2798     calling malloc() with a zero argument.
2799    
2800     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2801     optimization. I've improved things by keeping a bitmap of backreferences with
2802     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2803     fact referenced, the optimization can be applied. It is unlikely that a
2804     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2805     the match to follow \n) will appear inside brackets with a number greater than
2806     31, but if it does, any back reference > 31 suppresses the optimization.
2807    
2808     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2809     of disabling numbered capturing parentheses. Any opening parenthesis that is
2810     not followed by ? behaves as if it were followed by ?: but named parentheses
2811     can still be used for capturing (and they will acquire numbers in the usual
2812     way).
2813    
2814     41. Redesigned the return codes from the match() function into yes/no/error so
2815     that errors can be passed back from deep inside the nested calls. A malloc
2816     failure while inside a recursive subpattern call now causes the
2817     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2818    
2819     42. It is now possible to set a limit on the number of times the match()
2820     function is called in a call to pcre_exec(). This facility makes it possible to
2821     limit the amount of recursion and backtracking, though not in a directly
2822     obvious way, because the match() function is used in a number of different
2823     circumstances. The count starts from zero for each position in the subject
2824     string (for non-anchored patterns). The default limit is, for compatibility, a
2825     large number, namely 10 000 000. You can change this in two ways:
2826    
2827     (a) When configuring PCRE before making, you can use --with-match-limit=n
2828     to set a default value for the compiled library.
2829    
2830     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2831     a different value is set. See 45 below.
2832    
2833     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2834    
2835     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2836     of things that can be changed at compile time. The first argument specifies
2837     what is wanted and the second points to where the information is to be placed.
2838     The current list of available information is:
2839    
2840     PCRE_CONFIG_UTF8
2841    
2842     The output is an integer that is set to one if UTF-8 support is available;
2843     otherwise it is set to zero.
2844    
2845     PCRE_CONFIG_NEWLINE
2846    
2847     The output is an integer that it set to the value of the code that is used for
2848     newline. It is either LF (10) or CR (13).
2849    
2850     PCRE_CONFIG_LINK_SIZE
2851    
2852     The output is an integer that contains the number of bytes used for internal
2853     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2854    
2855     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2856    
2857     The output is an integer that contains the threshold above which the POSIX
2858     interface uses malloc() for output vectors. See item 31 above.
2859    
2860     PCRE_CONFIG_MATCH_LIMIT
2861    
2862     The output is an unsigned integer that contains the default limit of the number
2863     of match() calls in a pcre_exec() execution. See 42 above.
2864    
2865     44. pcretest has been upgraded by the addition of the -C option. This causes it
2866     to extract all the available output from the new pcre_config() function, and to
2867     output it. The program then exits immediately.
2868    
2869     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2870     order to support additional features. One way would have been to define
2871     pcre_exec2() (for example) with extra arguments, but this would not have been
2872     extensible, and would also have required all calls to the original function to
2873     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2874     is used for passing in "extra" data from pcre_study().
2875    
2876     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2877     contains the following fields:
2878    
2879     flags a bitmap indicating which of the following fields are set
2880     study_data opaque data from pcre_study()
2881     match_limit a way of specifying a limit on match() calls for a specific
2882     call to pcre_exec()
2883     callout_data data for callouts (see 49 below)
2884    
2885     The flag bits are also defined in pcre.h, and are
2886    
2887     PCRE_EXTRA_STUDY_DATA
2888     PCRE_EXTRA_MATCH_LIMIT
2889     PCRE_EXTRA_CALLOUT_DATA
2890    
2891     The pcre_study() function now returns one of these new pcre_extra blocks, with
2892     the actual study data pointed to by the study_data field, and the
2893     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2894     before. That is, this change is entirely upwards-compatible and requires no
2895     change to existing code.
2896    
2897     If you want to pass in additional data to pcre_exec(), you can either place it
2898     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2899     block.
2900    
2901     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2902     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2903     times with different match limits, until it finds the minimum value needed for
2904     pcre_exec() to complete. The value is then output. This can be instructive; for
2905     most simple matches the number is quite small, but for pathological cases it
2906     gets very large very quickly.
2907    
2908     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2909     returns the size of the data block pointed to by the study_data field in a
2910     pcre_extra block, that is, the value that was passed as the argument to
2911     pcre_malloc() when PCRE was getting memory in which to place the information
2912     created by pcre_study(). The fourth argument should point to a size_t variable.
2913     pcretest has been extended so that this information is shown after a successful
2914     pcre_study() call when information about the compiled regex is being displayed.
2915    
2916     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2917     because what follows is always an absolute path. (Later: it turns out that this
2918     is more than cosmetic for MinGW, because it doesn't like empty path
2919     components.)
2920    
2921     49. Some changes have been made to the callout feature (see 28 above):
2922    
2923     (i) A callout function now has three choices for what it returns:
2924    
2925     0 => success, carry on matching
2926     > 0 => failure at this point, but backtrack if possible
2927     < 0 => serious error, return this value from pcre_exec()
2928    
2929     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2930     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2931     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2932     use by callout functions. It will never be used by PCRE itself.
2933    
2934     (ii) The pcre_extra structure (see 45 above) has a void * field called
2935     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2936     pcre_callout_block structure has a field of the same name. The contents of
2937     the field passed in the pcre_extra structure are passed to the callout
2938     function in the corresponding field in the callout block. This makes it
2939     easier to use the same callout-containing regex from multiple threads. For
2940     testing, the pcretest program has a new data escape
2941    
2942     \C*n pass the number n (may be negative) as callout_data
2943    
2944     If the callout function in pcretest receives a non-zero value as
2945     callout_data, it returns that value.
2946    
2947     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2948     there were some redundant $(CFLAGS) in commands that are now specified as
2949     $(LINK), which already includes $(CFLAGS).
2950    
2951     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2952     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2953     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2954     one-byte characters throughout. Note that case-insensitive matching applies
2955     only to characters whose values are less than 256. PCRE doesn't support the
2956     notion of cases for higher-valued characters.
2957    
2958     (i) A character class whose characters are all within 0-255 is handled as
2959     a bit map, and the map is inverted for negative classes. Previously, a
2960     character > 255 always failed to match such a class; however it should
2961     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2962    
2963     (ii) A negated character class with a single character < 255 is coded as
2964     "not this character" (OP_NOT). This wasn't working properly when the test
2965     character was multibyte, either singly or repeated.
2966    
2967     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2968     mode, for example: \x{100}{2,3}.
2969    
2970     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2971     singly or repeated) now correctly test multibyte characters. However,
2972     PCRE doesn't recognize any characters with values greater than 255 as
2973     digits, spaces, or word characters. Such characters always match \D, \S,
2974     and \W, and never match \d, \s, or \w.
2975    
2976     (v) Classes may now contain characters and character ranges with values
2977     greater than 255. For example: [ab\x{100}-\x{400}].
2978    
2979     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2980     PCRE in UTF-8 mode.
2981    
2982     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2983     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2984     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2985     value.)
2986    
2987     53. The single man page has become too large. I have therefore split it up into
2988     a number of separate man pages. These also give rise to individual HTML pages;
2989     these are now put in a separate directory, and there is an index.html page that
2990     lists them all. Some hyperlinking between the pages has been installed.
2991    
2992     54. Added convenience functions for handling named capturing parentheses.
2993    
2994     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2995     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2996     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2997     are faulted.
2998    
2999     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3000     calling configure. These values are used when compiling the dftables.c program
3001     which is run to generate the source of the default character tables. They
3002     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3003     you will need to set these values.
3004    
3005     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3006    
3007    
3008     Version 3.9 02-Jan-02
3009 nigel 61 ---------------------
3010    
3011     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3012    
3013     2. If --disable-static was given, the building process failed when trying to
3014     build pcretest and pcregrep. (For some reason it was using libtool to compile
3015     them, which is not right, as they aren't part of the library.)
3016    
3017    
3018 nigel 59 Version 3.8 18-Dec-01
3019     ---------------------
3020    
3021     1. The experimental UTF-8 code was completely screwed up. It was packing the
3022     bytes in the wrong order. How dumb can you get?
3023    
3024    
3025 nigel 57 Version 3.7 29-Oct-01
3026     ---------------------
3027    
3028     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3029     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3030     this didn't happen under Solaris 8, where I normally test things.
3031    
3032 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3033     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3034     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3035     this fix an hour or so after the initial 3.7 release.)
3036 nigel 57
3037 nigel 59
3038 nigel 55 Version 3.6 23-Oct-01
3039     ---------------------
3040    
3041     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3042     offsets passed as NULL with zero offset count.
3043    
3044     2. The config.guess and config.sub files had not been updated when I moved to
3045     the latest autoconf.
3046    
3047    
3048 nigel 53 Version 3.5 15-Aug-01
3049     ---------------------
3050 nigel 5
3051 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3052     had been forgotten.
3053    
3054     2. By using declared but undefined structures, we can avoid using "void"
3055     definitions in pcre.h while keeping the internal definitions of the structures
3056     private.
3057    
3058     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3059     user point of view, this means that both static and shared libraries are built
3060     by default, but this can be individually controlled. More of the work of
3061     handling this static/shared cases is now inside libtool instead of PCRE's make
3062     file.
3063    
3064     4. The pcretest utility is now installed along with pcregrep because it is
3065     useful for users (to test regexs) and by doing this, it automatically gets
3066     relinked by libtool. The documentation has been turned into a man page, so
3067     there are now .1, .txt, and .html versions in /doc.
3068    
3069     5. Upgrades to pcregrep:
3070     (i) Added long-form option names like gnu grep.
3071     (ii) Added --help to list all options with an explanatory phrase.
3072     (iii) Added -r, --recursive to recurse into sub-directories.
3073     (iv) Added -f, --file to read patterns from a file.
3074    
3075     6. pcre_exec() was referring to its "code" argument before testing that
3076     argument for NULL (and giving an error if it was NULL).
3077    
3078     7. Upgraded Makefile.in to allow for compiling in a different directory from
3079     the source directory.
3080    
3081     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3082     options bits, the pointer it was passed was to an int instead of to an unsigned
3083     long int. This mattered only on 64-bit systems.
3084    
3085     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3086     generated) instead of pcre.in, which it its source. Also made the same change
3087     in several of the .c files.
3088    
3089     10. A new release of gcc defines printf() as a macro, which broke pcretest
3090     because it had an ifdef in the middle of a string argument for printf(). Fixed
3091     by using separate calls to printf().
3092    
3093     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3094     script, to force use of CR or LF instead of \n in the source. On non-Unix
3095     systems, the value can be set in config.h.
3096    
3097     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3098     absolute limit. Changed the text of the error message to make this clear, and
3099     likewise updated the man page.
3100    
3101     13. The limit of 99 on the number of capturing subpatterns has been removed.
3102     The new limit is 65535, which I hope will not be a "real" limit.
3103    
3104    
3105 nigel 51 Version 3.4 22-Aug-00
3106     ---------------------
3107    
3108     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3109    
3110     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3111    
3112    
3113 nigel 49 Version 3.3 01-Aug-00
3114     ---------------------
3115    
3116     1. If an octal character was given, but the value was greater than \377, it
3117     was not getting masked to the least significant bits, as documented. This could
3118     lead to crashes in some systems.
3119    
3120     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3121     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3122    
3123     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3124     These just pass their arguments on to (pcre_free)(), but they are provided
3125     because some uses of PCRE bind it to non-C systems that can call its functions,
3126     but cannot call free() or pcre_free() directly.
3127    
3128     4. Add "make test" as a synonym for "make check". Corrected some comments in
3129     the Makefile.
3130    
3131     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3132     Makefile.
3133    
3134     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3135     command called pgrep for grepping around the active processes.
3136    
3137     7. Added the beginnings of support for UTF-8 character strings.
3138    
3139     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3140     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3141     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3142     out for the ar command.)
3143    
3144    
3145 nigel 47 Version 3.2 12-May-00
3146     ---------------------
3147    
3148     This is purely a bug fixing release.
3149    
3150     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3151     of ZA. This was just one example of several cases that could provoke this bug,
3152     which was introduced by change 9 of version 2.00. The code for breaking
3153     infinite loops after an iteration that matches an empty string was't working
3154     correctly.
3155    
3156     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3157     when matched against abbab (for example). After matching an empty string, it
3158     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3159     caused it to match further down the string than it should.
3160    
3161     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3162     was there because it doesn't seem to be needed, and it causes trouble on some
3163     systems, as it is not a Standard C header. It has been removed.
3164    
3165     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3166     were reported on the Macintosh. The changes were from
3167    
3168     while ((c = *(++ptr)) != 0 && c != '\n');
3169     to
3170     while ((c = *(++ptr)) != 0 && c != '\n') ;
3171    
3172     Totally extraordinary, but if that's what it takes...
3173    
3174     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3175     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3176     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3177     assumes the way PCRE uses memmove() (always moving upwards).
3178    
3179     6. PCRE is being used in one environment where strchr() is not available. There
3180     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3181     faster code anyway.
3182    
3183    
3184 nigel 45 Version 3.1 09-Feb-00
3185     ---------------------
3186    
3187     The only change in this release is the fixing of some bugs in Makefile.in for
3188     the "install" target:
3189    
3190     (1) It was failing to install pcreposix.h.
3191    
3192     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3193    
3194    
3195 nigel 43 Version 3.0 01-Feb-00
3196     ---------------------
3197 nigel 41
3198     1. Add support for the /+ modifier to perltest (to output $` like it does in
3199     pcretest).
3200    
3201     2. Add support for the /g modifier to perltest.
3202    
3203     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3204     matches null strings.
3205    
3206     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3207     pattern. Perl treats empty patterns specially - it reuses the most recent
3208     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3209     effect.
3210    
3211     5. The POSIX interface was broken in that it was just handing over the POSIX
3212     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3213     required a bigger vector, with some working space on the end. This means that
3214     the POSIX wrapper now has to get and free some memory, and copy the results.
3215    
3216 nigel 43 6. Added some simple autoconf support, placing the test data and the
3217     documentation in separate directories, re-organizing some of the
3218     information files, and making it build pcre-config (a GNU standard). Also added
3219     libtool support for building PCRE as a shared library, which is now the
3220     default.
3221 nigel 41
3222 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3223     09 are not valid octal constants. Single digits will be used for minor values
3224     less than 10.
3225    
3226     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3227     existing programs that set these in the POSIX interface can use PCRE without
3228     modification.
3229    
3230     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3231     return all that pcre_info() returns, plus additional data. The pcre_info()
3232     function is retained for compatibility, but is considered to be obsolete.
3233    
3234     10. Added experimental recursion feature (?R) to handle one common case that
3235     Perl 5.6 will be able to do with (?p{...}).
3236    
3237     11. Added support for POSIX character classes like [:alpha:], which Perl is
3238     adopting.
3239    
3240    
3241 nigel 39 Version 2.08 31-Aug-99
3242     ----------------------
3243    
3244     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3245     trying to match at the startoffset position, but instead was moving forward to
3246     the next newline as if a previous match had failed.
3247    
3248     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3249     and could get into a loop if a null string was matched other than at the start
3250     of the subject.
3251    
3252     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3253     be distinguished at compile time, and for completeness also added PCRE_DATE.
3254    
3255     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3256     in GnuWin32 environments.
3257    
3258    
3259 nigel 37 Version 2.07 29-Jul-99
3260     ----------------------
3261    
3262     1. The documentation is now supplied in plain text form and HTML as well as in
3263     the form of man page sources.
3264    
3265     2. C++ compilers don't like assigning (void *) values to other pointer types.
3266     In particular this affects malloc(). Although there is no problem in Standard
3267     C, I've put in casts to keep C++ compilers happy.
3268    
3269     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3270     should be (const char *).
3271    
3272     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3273     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3274     However, I haven't made this a standard facility. The documentation doesn't
3275     mention it, and the Makefile doesn't support it.
3276    
3277     5. The Makefile now contains an "install" target, with editable destinations at
3278     the top of the file. The pcretest program is not installed.
3279    
3280     6. pgrep -V now gives the PCRE version number and date.
3281    
3282     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3283     causing the entire string to be ignored, instead of just the last character.
3284    
3285     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3286     non-matching string, it can take a very, very long time, even for strings of
3287     quite modest length, because of the nested recursion. PCRE now does better in
3288     some of these cases. It does this by remembering the last required literal
3289     character in the pattern, and pre-searching the subject to ensure it is present
3290     before running the real match. In other words, it applies a heuristic to detect
3291     some types of certain failure quickly, and in the above example, if presented
3292     with a string that has no trailing " it gives "no match" very quickly.
3293    
3294     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3295     other alternatives are tried instead.
3296    
3297    
3298 nigel 35 Version 2.06 09-Jun-99
3299     ----------------------
3300    
3301     1. Change pcretest's output for amount of store used to show just the code
3302     space, because the remainder (the data block) varies in size between 32-bit and
3303     64-bit systems.
3304    
3305     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3306     start matching at. This allows lookbehinds to work when searching for multiple
3307     occurrences in a string.
3308    
3309     3. Added additional options to pcretest for testing multiple occurrences:
3310    
3311     /+ outputs the rest of the string that follows a match
3312     /g loops for multiple occurrences, using the new startoffset argument
3313     /G loops for multiple occurrences by passing an incremented pointer
3314    
3315     4. PCRE wasn't doing the "first character" optimization for patterns starting
3316     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3317     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3318     the letter 'x'. On long subject strings, this gives a significant speed-up.
3319    
3320    
3321 nigel 33 Version 2.05 21-Apr-99
3322     ----------------------
3323    
3324     1. Changed the type of magic_number from int to long int so that it works
3325     properly on 16-bit systems.
3326    
3327     2. Fixed a bug which caused patterns starting with .* not to work correctly
3328     when the subject string contained newline characters. PCRE was assuming
3329     anchoring for such patterns in all cases, which is not correct because .* will
3330     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3331     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3332     must be retried after every newline in the subject.
3333    
3334    
3335 nigel 31 Version 2.04 18-Feb-99
3336     ----------------------
3337    
3338     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3339     computation of the store needed to hold the pattern was incorrect (too large).
3340     If such patterns were nested a few deep, this could multiply and become a real
3341     problem.
3342    
3343     2. Added /M option to pcretest to show the memory requirement of a specific
3344     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3345    
3346     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3347     compiled in such a way that the backtracking after subsequent failure was
3348     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3349     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3350    
3351    
3352 nigel 29 Version 2.03 02-Feb-99
3353     ----------------------
3354    
3355     1. Fixed typo and small mistake in man page.
3356    
3357 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3358     LICENCE file containing the conditions.
3359 nigel 29
3360     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3361     Perl, that is the internal \ allows the delimiter to be included in the
3362     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3363     the final delimiter, add \ to the end of the pattern (to test the error).
3364    
3365     4. Added the convenience functions for extracting substrings after a successful
3366     match. Updated pcretest to make it able to test these functions.
3367    
3368    
3369 nigel 27 Version 2.02 14-Jan-99
3370     ----------------------
3371    
3372     1. Initialized the working variables associated with each extraction so that
3373     their saving and restoring doesn't refer to uninitialized store.
3374    
3375     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3376     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3377     fix the problem.
3378    
3379     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3380     calls, and wasn't printing the correct value for compiling calls. Increased the
3381     default value of LOOPREPEAT, and the number of significant figures in the
3382     times.
3383    
3384     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3385    
3386     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3387     a building problem on Windows NT with a FAT file system.
3388    
3389    
3390 nigel 25 Version 2.01 21-Oct-98
3391     ----------------------
3392    
3393     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3394     to character tables built by pcre_maketables() in the current locale. If NULL
3395     is passed, the default tables are used.
3396    
3397    
3398 nigel 23 Version 2.00 24-Sep-98
3399 nigel 21 ----------------------
3400    
3401 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3402     it any more.
3403    
3404     2. Allow quantification of (?>) groups, and make it work correctly.
3405    
3406     3. The first character computation wasn't working for (?>) groups.
3407    
3408     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3409     end of the subject) and add 5.005's \z, which really does match only at the
3410     very end of the subject.
3411    
3412     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3413    
3414     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3415     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3416     localized options. All options to pcre_study() were also removed.
3417    
3418     7. Add other new features from 5.005:
3419    
3420     $(?<= positive lookbehind
3421     $(?<! negative lookbehind
3422     (?imsx-imsx) added the unsetting capability
3423     such a setting is global if at outer level; local otherwise
3424     (?imsx-imsx:) non-capturing groups with option setting
3425     (?(cond)re|re) conditional pattern matching
3426    
3427     A backreference to itself in a repeated group matches the previous
3428     captured string.
3429    
3430     8. General tidying up of studying (both automatic and via "study")
3431     consequential on the addition of new assertions.
3432    
3433     9. As in 5.005, unlimited repeated groups that could match an empty substring
3434     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3435     runtime if any iteration does actually match an empty substring.
3436    
3437     10. Include the RunTest script in the distribution.
3438    
3439     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3440     discrepancies, some of which were old and were also with respect to 5.004. They
3441     have now been fixed.
3442    
3443    
3444     Version 1.09 28-Apr-98
3445     ----------------------
3446    
3447 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3448     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3449     program crashes, or just wrong answers. This did not apply to negated classes
3450     containing more than one character, or to minima other than one.
3451    
3452    
3453 nigel 19 Version 1.08 27-Mar-98
3454     ----------------------
3455    
3456     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3457    
3458     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3459     latter must appear before anything that relies on it in the pattern.
3460    
3461    
3462 nigel 17 Version 1.07 16-Feb-98
3463     ----------------------
3464    
3465     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3466     repeat of a potentially empty string).
3467    
3468    
3469 nigel 15 Version 1.06 23-Jan-98
3470     ----------------------
3471    
3472     1. Added Markus Oberhumer's little patches for C++.
3473    
3474     2. Literal strings longer than 255 characters were broken.
3475    
3476    
3477 nigel 13 Version 1.05 23-Dec-97
3478     ----------------------
3479    
3480     1. Negated character classes containing more than one character were failing if
3481     PCRE_CASELESS was set at run time.
3482    
3483    
3484 nigel 11 Version 1.04 19-Dec-97
3485     ----------------------
3486    
3487     1. Corrected the man page, where some "const" qualifiers had been omitted.
3488    
3489     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3490     input syntax.
3491    
3492     3. Fixed memory leak which occurred when a regex with back references was
3493     matched with an offsets vector that wasn't big enough. The temporary memory
3494     that is used in this case wasn't being freed if the match failed.
3495    
3496     4. Tidied pcretest to ensure it frees memory that it gets.
3497    
3498     5. Temporary memory was being obtained in the case where the passed offsets
3499     vector was exactly big enough.
3500    
3501     6. Corrected definition of offsetof() from change 5 below.
3502    
3503     7. I had screwed up change 6 below and broken the rules for the use of
3504     setjmp(). Now fixed.
3505    
3506    
3507 nigel 9 Version 1.03 18-Dec-97
3508     ----------------------
3509    
3510     1. A erroneous regex with a missing opening parenthesis was correctly
3511     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3512     on some systems.
3513    
3514     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3515     it was reported that one broken compiler failed on the former because "code" is
3516     also an independent variable.
3517    
3518     3. The erroneous regex a[]b caused an array overrun reference.
3519    
3520     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3521     fail on data ending with that character. (It was going on too far, and checking
3522     the next character, typically a binary zero.) This was specific to the
3523     optimized code for single-character negative classes.
3524    
3525     5. Added a contributed patch from the TIN world which does the following:
3526    
3527     + Add an undef for memmove, in case the the system defines a macro for it.
3528    
3529     + Add a definition of offsetof(), in case there isn't one. (I don't know
3530     the reason behind this - offsetof() is part of the ANSI standard - but
3531     it does no harm).
3532    
3533     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3534     most of the places where whitespace preceded '#'. I have given up and
3535     allowed the remaining 2 cases to be at the margin.
3536    
3537     + Rename some variables in pcre to eliminate shadowing. This seems very
3538     pedantic, but does no harm, of course.
3539    
3540     6. Moved the call to setjmp() into its own function, to get rid of warnings
3541     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3542    
3543     7. Constructs such as \d{8,} were compiling into the equivalent of
3544 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3545 nigel 9 outcome, but in this particular case used more store than had been allocated,
3546     which caused the bug to be discovered because it threw up an internal error.
3547    
3548     8. The debugging code in both pcre and pcretest for outputting the compiled
3549     form of a regex was going wrong in the case of back references followed by
3550     curly-bracketed repeats.
3551    
3552    
3553 nigel 7 Version 1.02 12-Dec-97
3554     ----------------------
3555    
3556     1. Typos in pcre.3 and comments in the source fixed.
3557    
3558     2. Applied a contributed patch to get rid of places where it used to remove
3559     'const' from variables, and fixed some signed/unsigned and uninitialized
3560     variable warnings.
3561    
3562     3. Added the "runtest" target to Makefile.
3563    
3564     4. Set default compiler flag to -O2 rather than just -O.
3565    
3566    
3567 nigel 5 Version 1.01 19-Nov-97
3568     ----------------------
3569    
3570     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3571     like /([ab]*)*/, that is, for classes with more than one character in them.
3572    
3573     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3574     as /((?>a*))*/ (a PCRE_EXTRA facility).
3575    
3576    
3577     Version 1.00 18-Nov-97
3578     ----------------------
3579    
3580     1. Added compile-time macros to support systems such as SunOS4 which don't have
3581     memmove() or strerror() but have other things that can be used instead.
3582    
3583     2. Arranged that "make clean" removes the executables.
3584    
3585    
3586 nigel 3 Version 0.99 27-Oct-97
3587     ----------------------
3588    
3589     1. Fixed bug in code for optimizing classes with only one character. It was
3590     initializing a 32-byte map regardless, which could cause it to run off the end
3591     of the memory it had got.
3592    
3593     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3594    
3595    
3596     Version 0.98 22-Oct-97
3597     ----------------------
3598    
3599     1. Fixed bug in code for handling temporary memory usage when there are more
3600     back references than supplied space in the ovector. This could cause segfaults.
3601    
3602    
3603     Version 0.97 21-Oct-97
3604     ----------------------
3605    
3606     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3607    
3608     2. Optimized negated single characters not to use a bit map.
3609    
3610     3. Brought error texts together as macro definitions; clarified some of them;
3611     fixed one that was wrong - it said "range out of order" when it meant "invalid
3612     escape sequence".
3613    
3614     4. Changed some char * arguments to const char *.
3615    
3616     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3617    
3618     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3619     pcretest.
3620    
3621    
3622     Version 0.96 16-Oct-97
3623     ----------------------
3624    
3625     1. Added a simple "pgrep" utility to the distribution.
3626    
3627     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3628     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3629     where "ddd" means "one or more decimal digits".
3630    
3631     3. Fixed serious bug. If a pattern had a back reference, but the call to
3632     pcre_exec() didn't supply a large enough ovector to record the related
3633     identifying subpattern, the match always failed. PCRE now remembers the number
3634     of the largest back reference, and gets some temporary memory in which to save
3635     the offsets during matching if necessary, in order to ensure that
3636     backreferences always work.
3637    
3638     4. Increased the compatibility with Perl in a number of ways:
3639    
3640     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3641     to request this handling. The option can be set at compile or exec time.
3642    
3643     (b) $ matches before a terminating newline by default; an option
3644     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3645     mode). The option can be set at compile or exec time.
3646    
3647     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3648     the same as Perl's. If the decimal number it represents is less than 10
3649     or there aren't that many previous left capturing parentheses, an octal
3650     escape is read. Inside a character class, it's always an octal escape,
3651     even if it is a single digit.
3652    
3653     (d) An escaped but undefined alphabetic character is taken as a literal,
3654     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3655     escapes.
3656    
3657     (e) {0} is now permitted. (The previous item is removed from the compiled
3658     pattern).
3659    
3660     5. Changed all the names of code files so that the basic parts are no longer
3661     than 10 characters, and abolished the teeny "globals.c" file.
3662    
3663     6. Changed the handling of character classes; they are now done with a 32-byte
3664     bit map always.
3665    
3666     7. Added the -d and /D options to pcretest to make it possible to look at the
3667     internals of compilation without having to recompile pcre.
3668    
3669    
3670     Version 0.95 23-Sep-97
3671     ----------------------
3672    
3673     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3674     \x20 at the start of a run of normal characters. These were being treated as
3675     real characters, instead of the source characters being re-checked.
3676    
3677    
3678     Version 0.94 18-Sep-97
3679     ----------------------
3680    
3681     1. The functions are now thread-safe, with the caveat that the global variables
3682     containing pointers to malloc() and free() or alternative functions are the
3683     same for all threads.
3684    
3685     2. Get pcre_study() to generate a bitmap of initial characters for non-
3686     anchored patterns when this is possible, and use it if passed to pcre_exec().
3687    
3688    
3689     Version 0.93 15-Sep-97
3690     ----------------------
3691    
3692     1. /(b)|(:+)/ was computing an incorrect first character.
3693    
3694     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3695     but not actually doing anything yet.
3696    
3697     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3698     as Perl does (e.g. [-az] or [az-]).
3699    
3700     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3701     all possible positions.
3702    
3703     5. Split up into different modules to avoid including unneeded functions in a
3704     compiled binary. However, compile and exec are still in one module. The "study"
3705     function is split off.
3706    
3707     6. The character tables are now in a separate module whose source is generated
3708     by an auxiliary program - but can then be edited by hand if required. There are
3709     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3710     toupper() in the code.
3711    
3712     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3713     make them global. Abolish the function for setting them, as the caller can now
3714     set them directly.
3715    
3716    
3717     Version 0.92 11-Sep-97
3718     ----------------------
3719    
3720     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3721     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3722    
3723     2. Caseless matching was not working in character classes if the characters in
3724     the pattern were in upper case.
3725    
3726     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3727    
3728     4. Make PCRE_ANCHORED public and accept as a compile option.
3729    
3730     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3731     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3732     pass them.
3733    
3734     6. Give an error if bad option bits passed at compile or run time.
3735    
3736     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3737     pcretest to cause it to pass that flag.
3738    
3739     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3740     options, and the first character, if set.
3741    
3742     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3743    
3744    
3745     Version 0.91 10-Sep-97
3746     ----------------------
3747    
3748     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3749     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3750    
3751     2. PCRE was looping on encountering an indefinitely repeated back reference to
3752