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Revision 475 - (hide annotations) (download)
Sat Jan 2 18:21:30 2010 UTC (4 years, 3 months ago) by ph10
File size: 177419 byte(s)
Tidies to allow easier embedded compilation; avoid (double) where possible.

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

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