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Revision 455 - (hide annotations) (download)
Sat Sep 26 19:12:32 2009 UTC (4 years, 6 months ago) by ph10
File size: 174131 byte(s)
Added lower bound length-finding to pcre_study() and use it when matching; make 
the value available via pcre_fullinfo(); also fixed bugs connected with
pcre_study() in pcre_dfa_exec(). 

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8     was out-of-date, and there was no check on the pcre_compile() error code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

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