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Revision 497 - (hide annotations) (download)
Wed Mar 3 12:01:00 2010 UTC (4 years, 4 months ago) by ph10
File size: 182594 byte(s)
Use local function indirection for pcre_malloc etc. for Visual Studio and 
Symbian.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 491 Version 8.02 01-Mar-2010
5     ------------------------
6    
7     1. The Unicode data tables have been updated to Unicode 5.2.0.
8    
9 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
10     configured.
11 ph10 493
12     3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
13     original author of that file, following a query about its status.
14 ph10 494
15     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
16     inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
17 ph10 496
18     5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
19     quantifier applied to a forward-referencing subroutine call, could compile
20     incorrect code or give the error "internal error: previously-checked
21     referenced subpattern not found".
22 ph10 497
23     6. Both MS Visual Studio and Symbian OS have problems with initializing
24     variables to point to external functions. For these systems, therefore,
25     pcre_malloc etc. are now initialized to local functions that call the
26     relevant global functions.
27 ph10 491
28 ph10 492
29 ph10 489 Version 8.01 19-Jan-2010
30     ------------------------
31 ph10 471
32     1. If a pattern contained a conditional subpattern with only one branch (in
33 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
34 ph10 473 computed the wrong minimum data length (which is of course zero for such
35 ph10 489 subpatterns). This could cause incorrect "no match" results.
36 ph10 473
37     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
38 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
39     "internal error: code overflow at offset...". This happened only when
40 ph10 473 the reset was to the original external option setting. (An optimization
41     abstracts leading options settings into an external setting, which was the
42 ph10 472 cause of this.)
43 ph10 471
44 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
45     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
46     assertion pattern did not match (meaning that the assertion was true), it
47     was incorrectly treated as false if the SKIP had been reached during the
48     matching. This also applied to assertions used as conditions.
49 ph10 471
50 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
51     assertion subpattern, including such a pattern used as a condition,
52     unpredictable results occurred, instead of the error return
53     PCRE_ERROR_DFA_UITEM.
54 ph10 478
55 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
56     situation when an empty string is matched. It now does the fancy magic
57 ph10 478 stuff that is necessary.
58    
59     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
60 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
61 ph10 478
62 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
63     as part of something else:
64 ph10 478
65     (a) Change DEBUG to PCRE_DEBUG.
66    
67     (b) In pcre_compile(), rename the member of the "branch_chain" structure
68     called "current" as "current_branch", to prevent a collision with the
69 ph10 475 Linux macro when compiled as a kernel module.
70 ph10 478
71     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
72     prevent a collision with the Linux macro when compiled as a kernel
73 ph10 475 module.
74 ph10 478
75 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
76     cast potentially large values to (double). This has been changed to that
77 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
78     instead, thus avoiding the use of floating point arithmetic. (There is no
79     other use of FP in PCRE.) If int64_t is not found, the fallback is to
80     double.
81    
82     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
83 ph10 476 2005 (difference between two addresses compared to an unsigned value).
84 ph10 473
85 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
86     custom one, because of the following reported problem in Windows:
87 ph10 473
88 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
89 ph10 489 under Win32.
90 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
91 ph10 489 therefore missing the function definition.
92 ph10 478 - The compiler thus generates a "C" signature for the test function.
93     - The linker fails to find the "C" function.
94     - PCRE fails to configure if asked to do so against libbz2.
95 ph10 486
96 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
97     messages were output:
98 ph10 478
99 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
100     rerunning libtoolize, to keep the correct libtool macros in-tree.
101     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
102 ph10 486
103 ph10 479 I have done both of these things.
104 ph10 486
105 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
106 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
107     runaway infinite recursion. I updated the discussion in the pcrestack man
108     page.
109    
110     13. Now that we have gone to the x.xx style of version numbers, the minor
111     version may start with zero. Using 08 or 09 is a bad idea because users
112     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
113     interpreted as invalid octal numbers. I've updated the previous comment in
114     configure.ac, and also added a check that gives an error if 08 or 09 are
115 ph10 481 used.
116 ph10 486
117 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
118 ph10 483 causing partial matching to fail when the end of the subject matched \W
119     in a UTF-8 pattern where \W was quantified with a minimum of 3.
120 ph10 486
121 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
122 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
123 ph10 483 their definitions. The declarations used "const uschar *" and the
124     definitions used USPTR. Even though USPTR is normally defined as "const
125     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
126     reported that: "This difference in casting confuses some C++ compilers, for
127     example, SunCC recognizes above declarations as different functions and
128 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
129 ph10 483 USPTR.
130 ph10 486
131     16. GNU libtool is named differently on some systems. The autogen.sh script now
132 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
133     (FreeBSD).
134 ph10 478
135 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
136     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
137     comment: "Figure out how to create a longlong from a string: strtoll and
138     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
139     instance, but it only takes 2 args instead of 3!"
140 ph10 479
141 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
142     specification, with a corresponding code fix. A pattern such as
143     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
144     refers, was giving matches when it shouldn't. For example, xa=xaaa would
145     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
146     same bug. Such groups have to be quantified to be useful, or contained
147     inside another quantified group. (If there's no repetition, the reference
148     can never match.) The problem arises because, having left the group and
149     moved on to the rest of the pattern, a later failure that backtracks into
150     the group uses the captured value from the final iteration of the group
151     rather than the correct earlier one. I have fixed this in PCRE by forcing
152     any group that contains a reference to itself to be an atomic group; that
153     is, there cannot be any backtracking into it once it has completed. This is
154     similar to recursive and subroutine calls.
155 ph10 486
156 ph10 488
157 ph10 469 Version 8.00 19-Oct-09
158 ph10 418 ----------------------
159    
160     1. The table for translating pcre_compile() error codes into POSIX error codes
161 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
162     being within the table. This could lead to an OK return being given in
163 ph10 418 error.
164 ph10 461
165     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
166     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
167     in a Windows environment.
168    
169 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
170     zero, as does GNU grep. However, pcregrep was also printing all files when
171     --files-with-matches was added. Now, when both options are given, it prints
172     counts only for those files that have at least one match. (GNU grep just
173 ph10 461 prints the file name in this circumstance, but including the count seems
174     more useful - otherwise, why use --count?) Also ensured that the
175 ph10 420 combination -clh just lists non-zero counts, with no names.
176 ph10 461
177     4. The long form of the pcregrep -F option was incorrectly implemented as
178     --fixed_strings instead of --fixed-strings. This is an incompatible change,
179     but it seems right to fix it, and I didn't think it was worth preserving
180     the old behaviour.
181    
182     5. The command line items --regex=pattern and --regexp=pattern were not
183 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
184 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
185 ph10 422 which are compatible with GNU grep; these now work.
186 ph10 461
187     6. No libpcreposix.pc file was created for pkg-config; there was just
188 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
189 ph10 461
190 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
191 ph10 461 when UCP support is not needed, by modifying the Python script that
192 ph10 425 generates it from Unicode data files. This should not matter if the module
193     is correctly used as a library, but I received one complaint about 50K of
194     unwanted data. My guess is that the person linked everything into his
195     program rather than using a library. Anyway, it does no harm.
196 ph10 461
197 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
198 ph10 461 was a minimum greater than 1 for a wide character in a possessive
199 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
200     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
201     character. Chaos in the form of incorrect output or a compiling loop could
202     result.
203 ph10 461
204 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
205 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
206 ph10 426 partially matched by this function. In addition, if there are at least two
207 ph10 435 slots in the offset vector, the offset of the earliest inspected character
208     for the match and the offset of the end of the subject are set in them when
209 ph10 461 PCRE_ERROR_PARTIAL is returned.
210    
211 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
212     synonymous with PCRE_PARTIAL, for backwards compatibility, and
213     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
214 ph10 462 and may be more useful for multi-segment matching.
215 ph10 461
216     11. Partial matching with pcre_exec() is now more intuitive. A partial match
217     used to be given if ever the end of the subject was reached; now it is
218     given only if matching could not proceed because another character was
219     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
220     string "Z", which now yields "no match" instead of "partial match". In the
221     case of pcre_dfa_exec(), "no match" is given if every matching path for the
222     final character ended with (*FAIL).
223    
224 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
225 ph10 461 if the pattern had a "must contain" character that was already found in the
226 ph10 428 earlier partial match, unless partial matching was again requested. For
227     example, with the pattern /dog.(body)?/, the "must contain" character is
228     "g". If the first part-match was for the string "dog", restarting with
229 ph10 435 "sbody" failed. This bug has been fixed.
230 ph10 461
231     13. The string returned by pcre_dfa_exec() after a partial match has been
232     changed so that it starts at the first inspected character rather than the
233     first character of the match. This makes a difference only if the pattern
234     starts with a lookbehind assertion or \b or \B (\K is not supported by
235     pcre_dfa_exec()). It's an incompatible change, but it makes the two
236 ph10 435 matching functions compatible, and I think it's the right thing to do.
237 ph10 461
238 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
239 ph10 461 so that the demonstration program is easily available in environments where
240     PCRE has not been installed from source.
241    
242 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
243 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
244     library.
245 ph10 461
246 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
247 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
248 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
249 ph10 433 these options useful.
250 ph10 461
251     17. If a caller to the POSIX matching function regexec() passes a non-zero
252 ph10 438 value for nmatch with a NULL value for pmatch, the value of
253 ph10 461 nmatch is forced to zero.
254    
255 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
256 ph10 461 the diff command, as RunTest does. It now checks in the same way as
257 ph10 437 RunTest, and also checks for the -b option.
258 ph10 461
259 ph10 438 19. If an odd number of negated classes containing just a single character
260     interposed, within parentheses, between a forward reference to a named
261 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
262     an internal error, complaining that it could not find the referenced
263 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
264 ph10 461 [The bug was that it was starting one character too far in when skipping
265     over the character class, thus treating the ] as data rather than
266     terminating the class. This meant it could skip too much.]
267    
268 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
269 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
270 ph10 442 to have an empty string match not at the start, even when the pattern is
271 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
272    
273 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
274 ph10 461 than the maximum at the outer level, the higher number was returned, but
275     with unset values at the outer level. The correct (outer level) value is
276 ph10 446 now given.
277 ph10 461
278 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
279     PCRE did not set those parentheses (unlike Perl). I have now found a way to
280     make it do so. The string so far is captured, making this feature
281     compatible with Perl.
282 ph10 461
283     23. The tests have been re-organized, adding tests 11 and 12, to make it
284 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
285 ph10 461
286 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
287 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
288     does. Neither allows recursion.
289    
290     25. I finally figured out how to implement a request to provide the minimum
291     length of subject string that was needed in order to match a given pattern.
292     (It was back references and recursion that I had previously got hung up
293     on.) This code has now been added to pcre_study(); it finds a lower bound
294 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
295     bound, but using it to avoid searching strings that are too short does give
296     some useful speed-ups. The value is available to calling programs via
297     pcre_fullinfo().
298 ph10 461
299 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
300     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
301     study optimizations had never been tested with that matching function.
302     Oops. What is worse, even when it was passed study data, there was a bug in
303     pcre_dfa_exec() that meant it never actually used it. Double oops. There
304     were also very few tests of studied patterns with pcre_dfa_exec().
305 ph10 461
306 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
307     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
308     on the other side of the coin, they are no longer allowed to have different
309     names, because these cannot be distinguished in PCRE, and this has caused
310     confusion. (This is a difference from Perl.)
311 ph10 461
312     28. When duplicate subpattern names are present (necessarily with different
313     numbers, as required by 27 above), and a test is made by name in a
314     conditional pattern, either for a subpattern having been matched, or for
315     recursion in such a pattern, all the associated numbered subpatterns are
316 ph10 459 tested, and the overall condition is true if the condition is true for any
317     one of them. This is the way Perl works, and is also more like the way
318     testing by number works.
319 ph10 418
320 ph10 461
321 ph10 412 Version 7.9 11-Apr-09
322 ph10 376 ---------------------
323    
324 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
325 ph10 376 (pcretest), all targets were linked against these libraries. This included
326     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
327     libraries. This caused unwanted dependencies to be created. This problem
328 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
329 ph10 376 pcretest is linked with readline.
330 ph10 392
331 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
332     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
333     moved outside it again, because FALSE and TRUE are already defined in AIX,
334     but BOOL is not.
335 ph10 392
336     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
337 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
338 ph10 392
339 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
340     hyphens) following file names and line numbers when outputting matching
341 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
342 ph10 376 wording for the --colour (or --color) option.
343 ph10 392
344 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
345     was not coloured; this is different to GNU grep, so I have changed it to be
346     the same.
347 ph10 392
348 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
349 ph10 392 each matching line was coloured. Now it goes on to look for further matches
350     of any of the test patterns, which is the same behaviour as GNU grep.
351    
352     7. A pattern that could match an empty string could cause pcregrep to loop; it
353     doesn't make sense to accept an empty string match in pcregrep, so I have
354 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
355     seems to be how GNU grep behaves.
356 ph10 392
357 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
358 ph10 392 start or after a newline", because the conditional assertion was not being
359     correctly handled. The rule now is that both the assertion and what follows
360     in the first alternative must satisfy the test.
361    
362 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
363 ph10 399 condition was an assertion, PCRE could crash during matching, both with
364     pcre_exec() and pcre_dfa_exec().
365 ph10 392
366     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
367     used for matching.
368    
369     11. Unicode property support in character classes was not working for
370 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
371 ph10 388
372 ph10 392 12. Added the -M command line option to pcretest.
373    
374 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
375 ph10 389
376     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
377 ph10 390
378 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
379 ph10 390 wrapper.
380 ph10 392
381 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
382 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
383 ph10 391 string constants.
384 ph10 405
385 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
386     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
387 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
388     these, but not everybody uses configure.
389    
390     19. A conditional group that had only one branch was not being correctly
391     recognized as an item that could match an empty string. This meant that an
392     enclosing group might also not be so recognized, causing infinite looping
393     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
394     with the subject "ab", where knowledge that the repeated group can match
395 ph10 396 nothing is needed in order to break the loop.
396 ph10 405
397 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
398 ph10 405 exec(), but without supplying a callout function, matching went wrong.
399    
400     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
401     leak if the size of the offset vector was greater than 30. When the vector
402     is smaller, the saved offsets during recursion go onto a local stack
403     vector, but for larger vectors malloc() is used. It was failing to free
404     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
405 ph10 400 error, in fact).
406 ph10 405
407 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
408 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
409     problem, but was untidy.
410 ph10 376
411 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
412     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
413     included within another project.
414 ph10 411
415 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
416     slightly modified by me:
417 ph10 411
418     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
419     not building pcregrep.
420    
421 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
422 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
423    
424 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
425     duplicate group numbers, could behave incorrectly or give incorrect errors,
426     because when scanning forward to find the reference group, PCRE was not
427     taking into account the duplicate group numbers. A pattern such as
428     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
429 ph10 411
430     26. Changed a few more instances of "const unsigned char *" to USPTR, making
431     the feature of a custom pointer more persuasive (as requested by a user).
432 ph10 416
433 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
434 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
435     pre-defined.
436 ph10 392
437 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
438    
439 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
440     in the configuration summary.
441 ph10 405
442 ph10 411
443 ph10 374 Version 7.8 05-Sep-08
444 ph10 349 ---------------------
445    
446     1. Replaced UCP searching code with optimized version as implemented for Ad
447     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
448 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
449     to 5 times on some simple patterns that I tested. Permission was given to
450     distribute the MultiStage2.py script that generates the tables (it's not in
451     the tarball, but is in the Subversion repository).
452 ph10 349
453 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
454     scripts.
455 ph10 358
456 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
457     a group with a zero qualifier. The result of the study could be incorrect,
458 ph10 358 or the function might crash, depending on the pattern.
459    
460     4. Caseless matching was not working for non-ASCII characters in back
461 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
462 ph10 358 It now works when Unicode Property Support is available.
463    
464 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
465     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
466     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
467 ph10 358 truncation.
468 ph10 349
469 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
470    
471 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
472     pointers, in case they are 64-bit values.
473 ph10 371
474     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
475     test 2 if it fails.
476    
477 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
478 ph10 371 and a #define of that name to empty if it is not externally set. This is to
479     allow users of MSVC to set it if necessary.
480    
481     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
482 ph10 359 the convenience functions in the pcre_get.c source file.
483 ph10 371
484 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
485     could cause overwriting and/or a crash. This command provoked a crash in
486 ph10 371 some environments:
487    
488     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
489    
490 ph10 360 This potential security problem was recorded as CVE-2008-2371.
491 ph10 371
492 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
493     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
494 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
495 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
496     pcretest so that it places the subject at the end of its malloc-ed buffer.
497 ph10 371
498 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
499 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
500    
501 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
502 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
503     first line. This applied both to normal and DFA matching.
504    
505 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
506 ph10 371 /^[^d]*?$/8 failed to match "abc".
507 ph10 351
508 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
509    
510     17. Make it more clear in the documentation that values returned from
511 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
512 ph10 357
513 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
514 ph10 368
515 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
516     supplied by Stefan Weber. I made a further small update for 7.8 because
517 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
518     replaced by pcre_ucd.c.
519 ph10 371
520 ph10 373
521 ph10 347 Version 7.7 07-May-08
522 ph10 321 ---------------------
523    
524     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
525 ph10 345 a string to a long long, pretend we don't even have a long long." This is
526 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
527 ph10 345
528 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
529     pre-7.6 versions, which defined a global no_arg variable instead of putting
530 ph10 332 it in the RE class. (See also #8 below.)
531 ph10 345
532     3. Remove a line of dead code, identified by coverity and reported by Nuno
533     Lopes.
534    
535 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
536 ph10 321
537 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
538 ph10 345 of files, instead of just to the final components.
539    
540 ph10 324 (2) If there was more than one level of directory, the subdirectories were
541     skipped unless they satisfied the include/exclude conditions. This is
542     inconsistent with GNU grep (and could even be seen as contrary to the
543     pcregrep specification - which I improved to make it absolutely clear).
544     The action now is always to scan all levels of directory, and just
545     apply the include/exclude patterns to regular files.
546 ph10 345
547 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
548 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
549    
550 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
551 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
552 ph10 326 doesn't support NULs in patterns.
553 ph10 345
554     7. Added some missing "const"s to declarations of static tables in
555     pcre_compile.c and pcre_dfa_exec.c.
556    
557 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
558 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
559 ph10 345 first patch. And a third patch - this was a messy problem.)
560 ph10 321
561 ph10 345 9. Applied Craig's patch to remove the use of push_back().
562    
563 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
564     matching function regexec().
565 ph10 345
566     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
567     which, however, unlike Perl's \g{...}, are subroutine calls, not back
568 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
569     Oniguruma does).
570 ph10 345
571     12. Previously, a group with a zero repeat such as (...){0} was completely
572 ph10 335 omitted from the compiled regex. However, this means that if the group
573     was called as a subroutine from elsewhere in the pattern, things went wrong
574 ph10 345 (an internal error was given). Such groups are now left in the compiled
575     pattern, with a new opcode that causes them to be skipped at execution
576 ph10 335 time.
577 ph10 345
578 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
579     to the way PCRE behaves:
580 ph10 345
581 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
582 ph10 345
583     (b) A back reference to an unmatched subpattern matches an empty string
584 ph10 336 (Perl fails the current match path).
585 ph10 345
586 ph10 341 (c) A data ] in a character class must be notated as \] because if the
587 ph10 345 first data character in a class is ], it defines an empty class. (In
588 ph10 341 Perl it is not possible to have an empty class.) The empty class []
589     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
590     The negative empty class [^] matches any one character, independently
591     of the DOTALL setting.
592 ph10 345
593     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
594 ph10 340 non-existent subpattern following a character class starting with ']' and
595     containing () gave an internal compiling error instead of "reference to
596     non-existent subpattern". Fortunately, when the pattern did exist, the
597 ph10 345 compiled code was correct. (When scanning forwards to check for the
598 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
599 ph10 345 the class, so got the count wrong. When actually compiling, the reference
600 ph10 340 was subsequently set up correctly.)
601 ph10 345
602 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
603 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
604     other assertions are supported. I have made pcre_dfa_exec() support
605     (*FAIL).
606    
607 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
608 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
609     cannot be changed at match time, I realized I could make a small
610     improvement to matching performance by compiling OP_ALLANY instead of
611     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
612     on the OP_ANY path.
613    
614     17. Compiling pcretest on Windows with readline support failed without the
615 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
616 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
617    
618 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
619 ph10 345 ncurses library to be included for pcretest when ReadLine support is
620     requested, but also to allow for it to be overridden. This patch came from
621     Daniel Bergström.
622 ph10 347
623 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
624 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
625     any errors with the current Unicode tables. Thanks to Peter Kankowski for
626     spotting this.
627 ph10 324
628 ph10 332
629 ph10 319 Version 7.6 28-Jan-08
630 ph10 300 ---------------------
631    
632 ph10 302 1. A character class containing a very large number of characters with
633     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
634     overflow.
635 ph10 309
636     2. Patch to cut out the "long long" test in pcrecpp_unittest when
637     HAVE_LONG_LONG is not defined.
638    
639 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
640 ph10 304 bring them up to date and include new features. This patch includes:
641 ph10 309
642 ph10 304 - Fixed PH's badly added libz and libbz2 support.
643     - Fixed a problem with static linking.
644 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
645 ph10 304 - Fixed dftables problem and added an option.
646     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
647     HAVE_LONG_LONG.
648     - Added readline support for pcretest.
649 ph10 309 - Added an listing of the option settings after cmake has run.
650    
651 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
652     "pcre.dll" under mingw when using Configure/Make. I added stuff to
653     Makefile.am that cause it to include this special target, without
654     affecting anything else. Note that the same mingw target plus all
655     the other distribution libraries and programs are now supported
656     when configuring with CMake (see 6 below) instead of with
657     Configure/Make.
658 ph10 309
659 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
660     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
661 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
662     solves the problem, but it does no harm.
663 ph10 313
664 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
665 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
666 ph10 314 with CMake, and also correct the comment about stack recursion.
667 ph10 313
668 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
669 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
670     of a program that users should build themselves after PCRE is installed, so
671     building it automatically is not really right. What is more, it gave
672 ph10 312 trouble in some build environments.
673 ph10 300
674 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
675 ph10 308
676 ph10 319
677 ph10 298 Version 7.5 10-Jan-08
678 ph10 263 ---------------------
679    
680     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
681     values in parens when parsing an RE using the C++ wrapper."
682 ph10 286
683 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
684     Characters greater than 255 were excluded from the class instead of being
685     included.
686 ph10 286
687     3. The same bug as (2) above applied to negated POSIX classes such as
688 ph10 265 [:^space:].
689 ph10 286
690 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
691     defined or documented. It seems to have been a typo for PCRE_STATIC, so
692 ph10 286 I have changed it.
693    
694 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
695 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
696     first named subpattern whose name started with "a" (in other words, the
697 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
698     expected" is now given for (?&) (a zero-length name), and this patch also
699     makes it give the same error for \k'' (previously it complained that that
700     was a reference to a non-existent subpattern).
701 ph10 286
702 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
703 ph10 286 this is right because (?- can be followed by option settings as well as by
704 ph10 269 digits. I have, however, made the messages clearer.
705 ph10 286
706 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
707     than the number used in the conditional) now cause a compile-time error.
708     This is actually not compatible with Perl, which accepts such patterns, but
709     treats the conditional as always being FALSE (as PCRE used to), but it
710     seems to me that giving a diagnostic is better.
711 ph10 286
712 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
713 ph10 275 and messages.
714 ph10 286
715     9. Fix two occurrences of "backslash" in comments that should have been
716     "backspace".
717    
718     10. Remove two redundant lines of code that can never be obeyed (their function
719     was moved elsewhere).
720    
721     11. The program that makes PCRE's Unicode character property table had a bug
722     which caused it to generate incorrect table entries for sequences of
723 ph10 277 characters that have the same character type, but are in different scripts.
724 ph10 286 It amalgamated them into a single range, with the script of the first of
725 ph10 277 them. In other words, some characters were in the wrong script. There were
726     thirteen such cases, affecting characters in the following ranges:
727 ph10 286
728 ph10 277 U+002b0 - U+002c1
729     U+0060c - U+0060d
730 ph10 286 U+0061e - U+00612
731 ph10 277 U+0064b - U+0065e
732     U+0074d - U+0076d
733     U+01800 - U+01805
734     U+01d00 - U+01d77
735     U+01d9b - U+01dbf
736     U+0200b - U+0200f
737     U+030fc - U+030fe
738     U+03260 - U+0327f
739     U+0fb46 - U+0fbb1
740     U+10450 - U+1049d
741 ph10 286
742 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
743     compatible with GNU grep in that, if there was more than one match in a
744     line, it showed only the first of them. It now behaves in the same way as
745     GNU grep.
746 ph10 286
747     13. If the -o and -v options were combined for pcregrep, it printed a blank
748     line for every non-matching line. GNU grep prints nothing, and pcregrep now
749     does the same. The return code can be used to tell if there were any
750     non-matching lines.
751    
752 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
753    
754     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
755 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
756 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
757     and both kinds of lookbehind were skipped).
758    
759 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
760 ph10 284 inclusion of <windows.h> to before rather than after the definition of
761     INVALID_FILE_ATTRIBUTES (patch from David Byron).
762 ph10 263
763 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
764 ph10 286 character property caused pcre_compile() to compile bad code, which led at
765     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
766     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
767     caused the error; without that there was no problem.
768 ph10 263
769 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
770 ph10 286
771 ph10 289 19. Added --enable-pcretest-libreadline.
772 ph10 286
773 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
774 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
775 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
776     later patch that removed the other one (the right fix) and added unit tests
777     that check the return values (which was not done before).
778 ph10 292
779 ph10 291 21. Several CMake things:
780 ph10 287
781 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
782 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
783 ph10 288
784 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
785     linked with the newly-built libraries, not previously installed ones.
786 ph10 291
787 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
788 ph10 298
789     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
790     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
791     UTF-8 newline character). The key issue is that the pattern starts .*;
792     this means that the match must be either at the beginning, or after a
793     newline. The bug was in the code for advancing after a failed match and
794     checking that the new position followed a newline. It was not taking
795 ph10 294 account of UTF-8 characters correctly.
796 ph10 298
797     23. PCRE was behaving differently from Perl in the way it recognized POSIX
798     character classes. PCRE was not treating the sequence [:...:] as a
799     character class unless the ... were all letters. Perl, however, seems to
800     allow any characters between [: and :], though of course it rejects as
801     unknown any "names" that contain non-letters, because all the known class
802     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
803     for example, whereas PCRE did not - it did not recognize a POSIX character
804     class. This seemed a bit dangerous, so the code has been changed to be
805     closer to Perl. The behaviour is not identical to Perl, because PCRE will
806     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
807     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
808     Perl does, and where it didn't before.
809    
810 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
811     Windows environments %n is disabled by default.
812 ph10 292
813    
814 ph10 260 Version 7.4 21-Sep-07
815 ph10 230 ---------------------
816    
817     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
818 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
819     LF". That isn't really right - the whole point of the change was to try to
820     help when there was an actual mention of one of the two characters. So now
821     the change happens only if \r or \n (or a literal CR or LF) character is
822 ph10 230 encountered.
823 ph10 231
824     2. The 32-bit options word was also used for 6 internal flags, but the numbers
825     of both had grown to the point where there were only 3 bits left.
826     Fortunately, there was spare space in the data structure, and so I have
827     moved the internal flags into a new 16-bit field to free up more option
828 ph10 230 bits.
829 ph10 231
830     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
831     but did not set the internal JCHANGED flag - either of these is enough to
832     control the way the "get" function works - but the PCRE_INFO_JCHANGED
833     facility is supposed to tell if (?J) was ever used, so now (?J) at the
834 ph10 230 start sets both bits.
835    
836 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
837     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
838 ph10 230
839 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
840    
841     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
842 ph10 233 compatibility, even though it is no longer used.
843 ph10 243
844     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
845 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
846 ph10 259 windows.h file is present (where different names are used). [This was
847 ph10 257 reversed later after testing - see 16 below.]
848 ph10 243
849     8. Changed all #include <config.h> to #include "config.h". There were also
850 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
851 ph10 243
852 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
853 ph10 243 sequence off the lines that it output.
854    
855     10. It was pointed out to me that arrays of string pointers cause lots of
856     relocations when a shared library is dynamically loaded. A technique of
857     using a single long string with a table of offsets can drastically reduce
858     these. I have refactored PCRE in four places to do this. The result is
859 ph10 240 dramatic:
860 ph10 243
861 ph10 240 Originally: 290
862     After changing UCP table: 187
863 ph10 243 After changing error message table: 43
864 ph10 240 After changing table of "verbs" 36
865     After changing table of Posix names 22
866 ph10 243
867 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
868 ph10 247
869 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
870 ph10 247 unicode-properties was also set.
871    
872 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
873 ph10 231
874 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
875     checked only for CRLF.
876 ph10 233
877 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
878    
879 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
880 ph10 253
881 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
882 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
883     entirely. This removes changes made in 7 above.
884 ph10 256
885 ph10 261 17. The CMake files have been updated, and there is now more information about
886     building with CMake in the NON-UNIX-USE document.
887 ph10 257
888 ph10 261
889 ph10 228 Version 7.3 28-Aug-07
890 ph10 157 ---------------------
891    
892 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
893     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
894     brackets there is not right, since it causes compilers to look for an
895     installed pcre.h, not the version that is in the source that is being
896     compiled (which of course may be different). I have changed it back to:
897 ph10 197
898 ph10 189 #include "pcre.h"
899 ph10 197
900     I have a vague recollection that the change was concerned with compiling in
901     different directories, but in the new build system, that is taken care of
902     by the VPATH setting the Makefile.
903    
904 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
905     when the subject happened to end in the byte 0x85 (e.g. if the last
906     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
907     characters but of course it shouldn't be taken as a newline when it is part
908     of another character. The bug was that, for an unlimited repeat of . in
909     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
910     characters when looking for a newline.
911 ph10 197
912     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
913    
914     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
915     in debug output.
916    
917 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
918     long printing in the pcrecpp unittest when running under MinGW.
919 ph10 189
920 ph10 197 6. ESC_K was left out of the EBCDIC table.
921 ph10 189
922 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
923     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
924     limit also applies to "virtual nesting" when a pattern is recursive, and in
925     this case 1000 isn't so big. I have been able to remove this limit at the
926     expense of backing off one optimization in certain circumstances. Normally,
927     when pcre_exec() would call its internal match() function recursively and
928     immediately return the result unconditionally, it uses a "tail recursion"
929     feature to save stack. However, when a subpattern that can match an empty
930     string has an unlimited repetition quantifier, it no longer makes this
931     optimization. That gives it a stack frame in which to save the data for
932     checking that an empty string has been matched. Previously this was taken
933     from the 1000-entry workspace that had been reserved. So now there is no
934     explicit limit, but more stack is used.
935 ph10 189
936 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
937     syntax that is required for Windows, and which was going wrong for the
938     pcreposix and pcrecpp parts of the library. These were overlooked when this
939     problem was solved for the main library.
940 ph10 197
941 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
942     the size of patterns that contain repeated groups with explicit upper
943     limits. As the maximum quantifier is 65535, the maximum group length was
944     set at 30,000 so that the product of these two numbers did not overflow a
945     32-bit integer. However, it turns out that people want to use groups that
946     are longer than 30,000 bytes (though not repeat them that many times).
947     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
948     made it possible to implement the integer overflow checks in a much more
949     dynamic way, which I have now done. The artificial limitation on group
950     length has been removed - we now have only the limit on the total length of
951     the compiled pattern, which depends on the LINK_SIZE setting.
952 ph10 208
953     10. Fixed a bug in the documentation for get/copy named substring when
954     duplicate names are permitted. If none of the named substrings are set, the
955     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
956     empty string.
957    
958     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
959     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
960     because the ] is interpreted as the first data character and the
961     terminating ] is not found. PCRE has been made compatible with Perl in this
962     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
963     cause memory overwriting.
964    
965 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
966     string has been matched (to stop an infinite loop). It was not recognizing
967 ph10 208 a conditional subpattern that could match an empty string if that
968 ph10 206 subpattern was within another subpattern. For example, it looped when
969 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
970 ph10 206 condition was not nested. This bug has been fixed.
971 ph10 208
972 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
973     past the start of the subject in the presence of bytes with the top bit
974     set, for example "\x8aBCD".
975 ph10 211
976 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
977     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
978 ph10 200
979 ph10 211 14. Optimized (?!) to (*FAIL).
980 ph10 202
981 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
982     This restricts code points to be within the range 0 to 0x10FFFF, excluding
983     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
984     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
985     does: it's just the validity check that is more restrictive.
986 ph10 220
987     16. Inserted checks for integer overflows during escape sequence (backslash)
988     processing, and also fixed erroneous offset values for syntax errors during
989     backslash processing.
990    
991 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
992 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
993    
994 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
995     caused an overrun.
996 ph10 220
997     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
998     something other than just ASCII characters) inside a group that had an
999     unlimited repeat caused a loop at compile time (while checking to see
1000     whether the group could match an empty string).
1001    
1002 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1003     [\P{Any}] did so. (Error in the code for printing property names.)
1004 ph10 210
1005 ph10 220 21. An orphan \E inside a character class could cause a crash.
1006    
1007     22. A repeated capturing bracket such as (A)? could cause a wild memory
1008 ph10 218 reference during compilation.
1009 ph10 220
1010     23. There are several functions in pcre_compile() that scan along a compiled
1011     expression for various reasons (e.g. to see if it's fixed length for look
1012 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1013 ph10 220 present in the pattern. These operators have additional parameters compared
1014     with \d, etc, and these were not being taken into account when moving along
1015 ph10 218 the compiled data. Specifically:
1016 ph10 220
1017     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1018     length.
1019    
1020     (b) An item such as \pL+ within a repeated group could cause crashes or
1021 ph10 218 loops.
1022 ph10 220
1023 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1024 ph10 220 "reference to non-existent subpattern" error.
1025    
1026 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1027    
1028 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1029 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1030 ph10 211
1031 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1032 ph10 218
1033 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1034 ph10 223 character were causing crashes (broken optimization).
1035 ph10 227
1036 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1037 ph10 227 \p or \P) caused a compile-time loop.
1038    
1039 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1040     break. For example, the unstudied pattern [\r\n]A does not match the string
1041     "\r\nA" because change 7.0/46 below moves the current point on by two
1042     characters after failing to match at the start. However, the pattern \nA
1043 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1044     the same is true. There doesn't seem any very clean way out of this, but
1045     what I have chosen to do makes the common cases work: PCRE now takes note
1046     of whether there can be an explicit match for \r or \n anywhere in the
1047     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1048     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1049     pattern has explicit CR or LF references.
1050 ph10 222
1051 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1052 ph10 223
1053 ph10 227
1054 ph10 189 Version 7.2 19-Jun-07
1055     ---------------------
1056    
1057 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1058     which is apparently normally available under Windows.
1059 ph10 159
1060     2. Re-jig the pcregrep tests with different newline settings in an attempt
1061     to make them independent of the local environment's newline setting.
1062 ph10 157
1063 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1064 ph10 165
1065 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1066     was not 2, because the output contained actual offsets. The recent new
1067 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1068     usable with all link sizes.
1069    
1070 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1071     stack recursion. This gives a massive performance boost under BSD, but just
1072 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1073 ph10 164 in all cases.
1074 ph10 172
1075 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1076 ph10 172
1077 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1078     recursion call. It refers to the nth most recently opened parentheses.
1079 ph10 172
1080 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1081 ph10 172 to be opened parentheses.
1082    
1083     (c) Conditions that refer to capturing parentheses can be specified
1084 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1085 ph10 172
1086 ph10 168 (d) \K resets the start of the current match so that everything before
1087 ph10 172 is not part of it.
1088    
1089 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1090 ph10 172
1091 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1092 ph10 172 reference syntax.
1093 ph10 182
1094 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1095 ph10 182 alternative starts with the same number.
1096 ph10 172
1097 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1098    
1099 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1100     PCRE_INFO_JCHANGED.
1101    
1102     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1103     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1104 ph10 170 for detecting groups that can match an empty string.
1105 ph10 159
1106 ph10 172 9. A pattern with a very large number of alternatives (more than several
1107     hundred) was running out of internal workspace during the pre-compile
1108     phase, where pcre_compile() figures out how much memory will be needed. A
1109     bit of new cunning has reduced the workspace needed for groups with
1110     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1111     workspace instead of running out of the 4096 that are available.
1112 ph10 182
1113 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1114 ph10 172
1115 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1116     The report of the bug said:
1117 ph10 182
1118 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1119     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1120 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1121 ph10 185
1122 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1123 ph10 185 it matched the wrong number of bytes.
1124 ph10 172
1125 ph10 179
1126 ph10 155 Version 7.1 24-Apr-07
1127 ph10 98 ---------------------
1128    
1129 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1130 ph10 122 that is more "standard", making use of automake and other Autotools. There
1131 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1132     on this.
1133 ph10 111
1134     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1135     for recursive directory scanning broke on some systems because the files
1136     are not scanned in any specific order and on different systems the order
1137     was different. A call to "sort" has been inserted into RunGrepTest for the
1138     approprate test as a short-term fix. In the longer term there may be an
1139 ph10 100 alternative.
1140 ph10 111
1141 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1142 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1143     people do their own conversions for various reasons). The problems
1144     concerned the use of low-level troff macros .br and .in. I have therefore
1145     removed all such uses from the man pages (some were redundant, some could
1146 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1147     HTML has been updated to handle .nf/.fi and to complain if it encounters
1148     .br or .in.
1149 ph10 111
1150 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1151 ph10 123 arranged for config.h to be included in the distribution, with the name
1152 ph10 111 config.h.generic, for the benefit of those who have to compile without
1153     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1154    
1155     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1156     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1157 ph10 127 makevp.bat for the current PCRE, using the additional files
1158 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1159 ph10 111
1160     6. A Windows user reported a minor discrepancy with test 2, which turned out
1161     to be caused by a trailing space on an input line that had got lost in his
1162 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1163 ph10 111
1164 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1165 ph10 111 that is needed.
1166    
1167 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1168     as "const" (a) because they are and (b) because it helps the PHP
1169     maintainers who have recently made a script to detect big data structures
1170 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1171     to update Builducptable as well, so it won't revert if ucptable.h is ever
1172 ph10 105 re-created.
1173 ph10 111
1174     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1175 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1176 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1177     support is not required. This saves 1.5-2K of code, which is important in
1178 ph10 107 some applications.
1179 ph10 111
1180 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1181 ph10 111 so as not to refer to the tables, even though these functions will never be
1182     called when UTF-8 support is disabled. Otherwise there are problems with a
1183     shared library.
1184    
1185 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1186    
1187     (a) It was defining its arguments as char * instead of void *.
1188    
1189 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1190     a long time ago when I wrote it, but is no longer the case.
1191    
1192 ph10 118 The emulated memove() is provided for those environments that have neither
1193 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1194 ph10 118 is clearly not the case, as these two bugs were recently reported.
1195 ph10 123
1196 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1197 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1198     pages, and it removes trailing spaces from listed files. It also creates
1199     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1200     case, it wraps all the #defines with #ifndefs. This script should be run
1201 ph10 111 before "make dist".
1202 ph10 123
1203 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1204     with Unicode property support.
1205 ph10 123
1206     (a) For a maximizing quantifier, if the two different cases of the
1207     character were of different lengths in their UTF-8 codings (there are
1208     some cases like this - I found 11), and the matching function had to
1209 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1210     were both the same length.
1211 ph10 123
1212     (b) When PCRE was configured to use the heap rather than the stack for
1213     recursion during matching, it was not correctly preserving the data for
1214     the other case of a UTF-8 character when checking ahead for a match
1215     while processing a minimizing repeat. If the check also involved
1216 ph10 115 matching a wide character, but failed, corruption could cause an
1217     erroneous result when trying to check for a repeat of the original
1218     character.
1219 ph10 123
1220 ph10 116 13. Some tidying changes to the testing mechanism:
1221 ph10 98
1222 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1223     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1224 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1225     this for UTF-8.) The configure.ac script no longer substitutes the
1226     relevant variables.
1227    
1228 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1229     with length and offset values. This means that the output is different
1230     for different internal link sizes. Test 2 is skipped for link sizes
1231     other than 2 because of this, bypassing the problem. Unfortunately,
1232     there was also a test in test 3 (the locale tests) that used /B and
1233 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1234     I have added a new /Z option to pcretest that replaces the length and
1235     offset values with spaces. This is now used to make test 3 independent
1236 ph10 122 of link size. (Test 2 will be tidied up later.)
1237 ph10 123
1238     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1239 ph10 122 segmentation fault instead of returning the appropriate error message.
1240 ph10 134
1241 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1242 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1243     This doesn't seem right; it now treats the CRLF combination as the line
1244     ending, and so does not match in that case. It's only a pattern such as ^$
1245     that would hit this one: something like ^ABC$ would have failed after \r
1246     and then tried again after \r\n.
1247    
1248 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1249 ph10 134 in an attempt to make files that differ only in their line terminators
1250     compare equal. This works on Linux.
1251 ph10 142
1252 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1253     as it exited. This is now fixed, thanks to valgrind.
1254 ph10 142
1255 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1256 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1257     was because its rules for how to advance for /g after matching an empty
1258 ph10 143 string at the end of a line did not allow for this case. They now check for
1259     it specially.
1260 ph10 150
1261     20. pcretest is supposed to handle patterns and data of any length, by
1262     extending its buffers when necessary. It was getting this wrong when the
1263 ph10 147 buffer for a data line had to be extended.
1264 ph10 150
1265 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1266 ph10 150 CRLF as a newline sequence.
1267 ph10 152
1268 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1269 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1270     I have nevertheless tidied it up.
1271 ph10 111
1272 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1273 ph10 123
1274 ph10 153 24. Added a man page for pcre-config.
1275 ph10 152
1276 ph10 153
1277 nigel 93 Version 7.0 19-Dec-06
1278     ---------------------
1279    
1280     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1281     moving to gcc 4.1.1.
1282    
1283     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1284     sys/time.h, which is documented as needed for this function. It doesn't
1285     seem to matter on Linux, but it showed up on some releases of OS X.
1286    
1287     3. It seems that there are systems where bytes whose values are greater than
1288     127 match isprint() in the "C" locale. The "C" locale should be the
1289     default when a C program starts up. In most systems, only ASCII printing
1290     characters match isprint(). This difference caused the output from pcretest
1291     to vary, making some of the tests fail. I have changed pcretest so that:
1292    
1293     (a) When it is outputting text in the compiled version of a pattern, bytes
1294     other than 32-126 are always shown as hex escapes.
1295    
1296     (b) When it is outputting text that is a matched part of a subject string,
1297     it does the same, unless a different locale has been set for the match
1298     (using the /L modifier). In this case, it uses isprint() to decide.
1299    
1300     4. Fixed a major bug that caused incorrect computation of the amount of memory
1301     required for a compiled pattern when options that changed within the
1302     pattern affected the logic of the preliminary scan that determines the
1303     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1304     that the computed length was too small. The symptoms of this bug were
1305     either the PCRE error "internal error: code overflow" from pcre_compile(),
1306     or a glibc crash with a message such as "pcretest: free(): invalid next
1307     size (fast)". Examples of patterns that provoked this bug (shown in
1308     pcretest format) are:
1309    
1310     /(?-x: )/x
1311     /(?x)(?-x: \s*#\s*)/
1312     /((?i)[\x{c0}])/8
1313     /(?i:[\x{c0}])/8
1314    
1315     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1316     is now done differently.
1317    
1318     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1319     wrapper classes; (b) implement a new function in the C++ scanner that is
1320     more efficient than the old way of doing things because it avoids levels of
1321     recursion in the regex matching; (c) add a paragraph to the documentation
1322     for the FullMatch() function.
1323    
1324     6. The escape sequence \n was being treated as whatever was defined as
1325     "newline". Not only was this contrary to the documentation, which states
1326     that \n is character 10 (hex 0A), but it also went horribly wrong when
1327     "newline" was defined as CRLF. This has been fixed.
1328    
1329     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1330     was being set to -1 for the "end of line" case (supposedly a value that no
1331     character can have). Though this value is never used (the check for end of
1332     line is "zero bytes in current character"), it caused compiler complaints.
1333     I've changed it to 0xffffffff.
1334    
1335     8. In pcre_version.c, the version string was being built by a sequence of
1336     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1337     string (as it is for production releases) called a macro with an empty
1338     argument. The C standard says the result of this is undefined. The gcc
1339     compiler treats it as an empty string (which was what was wanted) but it is
1340     reported that Visual C gives an error. The source has been hacked around to
1341     avoid this problem.
1342    
1343     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1344     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1345     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1346     of them did).
1347    
1348     10. Originally, pcretest opened its input and output without "b"; then I was
1349     told that "b" was needed in some environments, so it was added for release
1350     5.0 to both the input and output. (It makes no difference on Unix-like
1351     systems.) Later I was told that it is wrong for the input on Windows. I've
1352     now abstracted the modes into two macros, to make it easier to fiddle with
1353     them, and removed "b" from the input mode under Windows.
1354    
1355     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1356    
1357     12. Added -help and --help to pcretest as an official way of being reminded
1358     of the options.
1359    
1360     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1361     and pcrecpp.cc because they annoy compilers at high warning levels.
1362    
1363     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1364    
1365     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1366     scripts are not C programs :-) and which was not noticed because it works
1367     on Linux.
1368    
1369     16. pcretest is supposed to handle any length of pattern and data line (as one
1370     line or as a continued sequence of lines) by extending its input buffer if
1371     necessary. This feature was broken for very long pattern lines, leading to
1372     a string of junk being passed to pcre_compile() if the pattern was longer
1373     than about 50K.
1374    
1375     17. I have done a major re-factoring of the way pcre_compile() computes the
1376     amount of memory needed for a compiled pattern. Previously, there was code
1377     that made a preliminary scan of the pattern in order to do this. That was
1378     OK when PCRE was new, but as the facilities have expanded, it has become
1379     harder and harder to keep it in step with the real compile phase, and there
1380     have been a number of bugs (see for example, 4 above). I have now found a
1381     cunning way of running the real compile function in a "fake" mode that
1382     enables it to compute how much memory it would need, while actually only
1383     ever using a few hundred bytes of working memory and without too many
1384     tests of the mode. This should make future maintenance and development
1385     easier. A side effect of this work is that the limit of 200 on the nesting
1386     depth of parentheses has been removed (though this was never a serious
1387     limitation, I suspect). However, there is a downside: pcre_compile() now
1388     runs more slowly than before (30% or more, depending on the pattern). I
1389     hope this isn't a big issue. There is no effect on runtime performance.
1390    
1391     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1392     newline (only possible for the last line of a file) and it was a
1393     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1394    
1395     19. Added additional timing features to pcretest. (1) The -tm option now times
1396     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1397     separate command line item, by a number that specifies the number of
1398     repeats to use when timing. The default is 50000; this gives better
1399     precision, but takes uncomfortably long for very large patterns.
1400    
1401     20. Extended pcre_study() to be more clever in cases where a branch of a
1402     subpattern has no definite first character. For example, (a*|b*)[cd] would
1403     previously give no result from pcre_study(). Now it recognizes that the
1404     first character must be a, b, c, or d.
1405    
1406     21. There was an incorrect error "recursive call could loop indefinitely" if
1407     a subpattern (or the entire pattern) that was being tested for matching an
1408     empty string contained only one non-empty item after a nested subpattern.
1409     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1410     incorrectly, because the \d was being skipped in the check.
1411    
1412     22. The pcretest program now has a new pattern option /B and a command line
1413     option -b, which is equivalent to adding /B to every pattern. This causes
1414     it to show the compiled bytecode, without the additional information that
1415     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1416     is the same as /B/I).
1417    
1418     23. A new optimization is now able automatically to treat some sequences such
1419     as a*b as a*+b. More specifically, if something simple (such as a character
1420     or a simple class like \d) has an unlimited quantifier, and is followed by
1421     something that cannot possibly match the quantified thing, the quantifier
1422     is automatically "possessified".
1423    
1424     24. A recursive reference to a subpattern whose number was greater than 39
1425     went wrong under certain circumstances in UTF-8 mode. This bug could also
1426     have affected the operation of pcre_study().
1427    
1428     25. Realized that a little bit of performance could be had by replacing
1429     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1430    
1431     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1432    
1433     27. Possessive quantifiers such as a++ were previously implemented by turning
1434     them into atomic groups such as ($>a+). Now they have their own opcodes,
1435     which improves performance. This includes the automatically created ones
1436     from 23 above.
1437    
1438     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1439     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1440     the first matched character to be a colon. This applied both to named and
1441     numbered groups.
1442    
1443     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1444    
1445     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1446     building PCRE on Windows easier, so I have included it in the distribution.
1447    
1448     31. There is now a check in pcretest against a ridiculously large number being
1449     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1450     loop, the loop is abandoned.
1451    
1452     32. Forward references to subpatterns in conditions such as (?(2)...) where
1453     subpattern 2 is defined later cause pcre_compile() to search forwards in
1454     the pattern for the relevant set of parentheses. This search went wrong
1455     when there were unescaped parentheses in a character class, parentheses
1456     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1457    
1458     33. "Subroutine" calls and backreferences were previously restricted to
1459     referencing subpatterns earlier in the regex. This restriction has now
1460     been removed.
1461    
1462     34. Added a number of extra features that are going to be in Perl 5.10. On the
1463     whole, these are just syntactic alternatives for features that PCRE had
1464     previously implemented using the Python syntax or my own invention. The
1465     other formats are all retained for compatibility.
1466    
1467     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1468     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1469     also .NET compatible.
1470    
1471     (b) A recursion or subroutine call to a named group can now be defined as
1472     (?&name) as well as (?P>name).
1473    
1474     (c) A backreference to a named group can now be defined as \k<name> or
1475     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1476     5.10, are also .NET compatible.
1477    
1478     (d) A conditional reference to a named group can now use the syntax
1479     (?(<name>) or (?('name') as well as (?(name).
1480    
1481     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1482     groups (named and numbered) that are never evaluated inline, but can be
1483     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1484     is always false. There may be only one alternative in such a group.
1485    
1486     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1487     as the simple (?(R). The condition is true only if the most recent
1488     recursion is that of the given number or name. It does not search out
1489     through the entire recursion stack.
1490    
1491     (g) The escape \gN or \g{N} has been added, where N is a positive or
1492     negative number, specifying an absolute or relative reference.
1493    
1494     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1495     some "unreachable code" warnings.
1496    
1497     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1498     things, this adds five new scripts.
1499    
1500     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1501     There were also incompatibilities regarding the handling of \Q..\E inside
1502     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1503     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1504    
1505     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1506     matches an empty string, and forcibly breaks the loop. There were bugs in
1507     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1508     against aaaa the result was just "a" rather than "aaaa", for example. Two
1509     separate and independent bugs (that affected different cases) have been
1510     fixed.
1511    
1512     39. Refactored the code to abolish the use of different opcodes for small
1513     capturing bracket numbers. This is a tidy that I avoided doing when I
1514     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1515     The new approach is not only tidier, it makes it possible to reduce the
1516     memory needed to fix the previous bug (38).
1517    
1518     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1519     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1520     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1521     mode.
1522    
1523     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1524     report.
1525    
1526     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1527     copy construction and assignment in the C++ wrapper.
1528    
1529     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1530     couple of bugs that could have given wrong results in the "--newline=crlf"
1531     case.
1532    
1533     44. Added a number of casts and did some reorganization of signed/unsigned int
1534     variables following suggestions from Dair Grant. Also renamed the variable
1535     "this" as "item" because it is a C++ keyword.
1536    
1537     45. Arranged for dftables to add
1538    
1539     #include "pcre_internal.h"
1540    
1541     to pcre_chartables.c because without it, gcc 4.x may remove the array
1542     definition from the final binary if PCRE is built into a static library and
1543     dead code stripping is activated.
1544    
1545     46. For an unanchored pattern, if a match attempt fails at the start of a
1546     newline sequence, and the newline setting is CRLF or ANY, and the next two
1547     characters are CRLF, advance by two characters instead of one.
1548    
1549    
1550 nigel 91 Version 6.7 04-Jul-06
1551     ---------------------
1552    
1553     1. In order to handle tests when input lines are enormously long, pcretest has
1554     been re-factored so that it automatically extends its buffers when
1555     necessary. The code is crude, but this _is_ just a test program. The
1556     default size has been increased from 32K to 50K.
1557    
1558     2. The code in pcre_study() was using the value of the re argument before
1559     testing it for NULL. (Of course, in any sensible call of the function, it
1560     won't be NULL.)
1561    
1562     3. The memmove() emulation function in pcre_internal.h, which is used on
1563     systems that lack both memmove() and bcopy() - that is, hardly ever -
1564     was missing a "static" storage class specifier.
1565    
1566     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1567     containing an extended class (one that cannot be represented by a bitmap
1568     because it contains high-valued characters or Unicode property items, e.g.
1569     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1570     pattern, but PCRE should not loop if you do not (it no longer does).
1571     [Detail: two cases were found: (a) a repeated subpattern containing an
1572     extended class; (b) a recursive reference to a subpattern that followed a
1573     previous extended class. It wasn't skipping over the extended class
1574     correctly when UTF-8 mode was not set.]
1575    
1576     5. A negated single-character class was not being recognized as fixed-length
1577     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1578     compile error "lookbehind assertion is not fixed length".
1579    
1580     6. The RunPerlTest auxiliary script was showing an unexpected difference
1581     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1582     write a Perl script that can interpret lines of an input file either as
1583     byte characters or as UTF-8, which is what "perltest" was being required to
1584     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1585     can't do is switch easily at run time between having the "use utf8;" pragma
1586     or not. In the end, I fudged it by using the RunPerlTest script to insert
1587     "use utf8;" explicitly for the UTF-8 tests.
1588    
1589     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1590     the end of the subject string, contrary to the documentation and to what
1591     Perl does. This was true of both matching functions. Now it matches only at
1592     the start of the subject and immediately after *internal* newlines.
1593    
1594     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1595     a pointer to an int instead of a pointer to an unsigned long int. This
1596     caused problems on 64-bit systems.
1597    
1598     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1599     instance of the 'standard' template library not being so standard".
1600    
1601     10. There was no check on the number of named subpatterns nor the maximum
1602     length of a subpattern name. The product of these values is used to compute
1603     the size of the memory block for a compiled pattern. By supplying a very
1604     long subpattern name and a large number of named subpatterns, the size
1605     computation could be caused to overflow. This is now prevented by limiting
1606     the length of names to 32 characters, and the number of named subpatterns
1607     to 10,000.
1608    
1609     11. Subpatterns that are repeated with specific counts have to be replicated in
1610     the compiled pattern. The size of memory for this was computed from the
1611     length of the subpattern and the repeat count. The latter is limited to
1612     65535, but there was no limit on the former, meaning that integer overflow
1613     could in principle occur. The compiled length of a repeated subpattern is
1614     now limited to 30,000 bytes in order to prevent this.
1615    
1616     12. Added the optional facility to have named substrings with the same name.
1617    
1618     13. Added the ability to use a named substring as a condition, using the
1619     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1620     are numbers (not recommended). Forward references are permitted.
1621    
1622     14. Added forward references in named backreferences (if you see what I mean).
1623    
1624     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1625     pattern could run off the end of the subject. For example, the pattern
1626     "(?s)(.{1,5})"8 did this with the subject "ab".
1627    
1628     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1629     PCRE_CASELESS was set when matching characters that were quantified with ?
1630     or *.
1631    
1632     17. A character class other than a single negated character that had a minimum
1633     but no maximum quantifier - for example [ab]{6,} - was not handled
1634     correctly by pce_dfa_exec(). It would match only one character.
1635    
1636     18. A valid (though odd) pattern that looked like a POSIX character
1637     class but used an invalid character after [ (for example [[,abc,]]) caused
1638     pcre_compile() to give the error "Failed: internal error: code overflow" or
1639     in some cases to crash with a glibc free() error. This could even happen if
1640     the pattern terminated after [[ but there just happened to be a sequence of
1641     letters, a binary zero, and a closing ] in the memory that followed.
1642    
1643     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1644     over the years. Originally (before any Unicode support), just the bottom 8
1645     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1646     output from "man perlunicode" includes this:
1647    
1648     The regular expression compiler produces polymorphic opcodes. That
1649     is, the pattern adapts to the data and automatically switches to
1650     the Unicode character scheme when presented with Unicode data--or
1651     instead uses a traditional byte scheme when presented with byte
1652     data.
1653    
1654     Sadly, a wide octal escape does not cause a switch, and in a string with
1655     no other multibyte characters, these octal escapes are treated as before.
1656     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1657     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1658     Unicode string.
1659    
1660     I have not perpetrated such confusion in PCRE. Up till now, it took just
1661     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1662     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1663     translate to the appropriate multibyte character.
1664    
1665     29. Applied some refactoring to reduce the number of warnings from Microsoft
1666     and Borland compilers. This has included removing the fudge introduced
1667     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1668     a warning about an unused variable.
1669    
1670     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1671     characters since release 4.0, because Perl (from release 5.004) does not.
1672     [Or at least, is documented not to: some releases seem to be in conflict
1673     with the documentation.] However, when a pattern was studied with
1674     pcre_study() and all its branches started with \s, PCRE still included VT
1675     as a possible starting character. Of course, this did no harm; it just
1676     caused an unnecessary match attempt.
1677    
1678     22. Removed a now-redundant internal flag bit that recorded the fact that case
1679     dependency changed within the pattern. This was once needed for "required
1680     byte" processing, but is no longer used. This recovers a now-scarce options
1681     bit. Also moved the least significant internal flag bit to the most-
1682     significant bit of the word, which was not previously used (hangover from
1683     the days when it was an int rather than a uint) to free up another bit for
1684     the future.
1685    
1686     23. Added support for CRLF line endings as well as CR and LF. As well as the
1687     default being selectable at build time, it can now be changed at runtime
1688     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1689     specify that it is scanning data with non-default line endings.
1690    
1691     24. Changed the definition of CXXLINK to make it agree with the definition of
1692     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1693    
1694     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1695     recursions. This makes a big different to stack usage for some patterns.
1696    
1697     26. If a subpattern containing a named recursion or subroutine reference such
1698     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1699     the space required for the compiled pattern went wrong and gave too small a
1700     value. Depending on the environment, this could lead to "Failed: internal
1701     error: code overflow at offset 49" or "glibc detected double free or
1702     corruption" errors.
1703    
1704     27. Applied patches from Google (a) to support the new newline modes and (b) to
1705     advance over multibyte UTF-8 characters in GlobalReplace.
1706    
1707     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1708     difference for some implementation of PCRE in some Windows version.
1709    
1710     29. Added some extra testing facilities to pcretest:
1711    
1712     \q<number> in a data line sets the "match limit" value
1713     \Q<number> in a data line sets the "match recursion limt" value
1714     -S <number> sets the stack size, where <number> is in megabytes
1715    
1716     The -S option isn't available for Windows.
1717    
1718    
1719 nigel 89 Version 6.6 06-Feb-06
1720     ---------------------
1721    
1722     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1723     in pcreposix.h. I have copied the definition from pcre.h.
1724    
1725     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1726     because pcre.h is no longer a built file.
1727    
1728     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1729     not normally included in the compiled code.
1730    
1731    
1732 nigel 87 Version 6.5 01-Feb-06
1733     ---------------------
1734    
1735     1. When using the partial match feature with pcre_dfa_exec(), it was not
1736     anchoring the second and subsequent partial matches at the new starting
1737     point. This could lead to incorrect results. For example, with the pattern
1738     /1234/, partially matching against "123" and then "a4" gave a match.
1739    
1740     2. Changes to pcregrep:
1741    
1742     (a) All non-match returns from pcre_exec() were being treated as failures
1743     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1744     error message is output. Some extra information is given for the
1745     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1746     probably the only errors that are likely to be caused by users (by
1747     specifying a regex that has nested indefinite repeats, for instance).
1748     If there are more than 20 of these errors, pcregrep is abandoned.
1749    
1750     (b) A binary zero was treated as data while matching, but terminated the
1751     output line if it was written out. This has been fixed: binary zeroes
1752     are now no different to any other data bytes.
1753    
1754     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1755     used to set a locale for matching. The --locale=xxxx long option has
1756     been added (no short equivalent) to specify a locale explicitly on the
1757     pcregrep command, overriding the environment variables.
1758    
1759     (d) When -B was used with -n, some line numbers in the output were one less
1760     than they should have been.
1761    
1762     (e) Added the -o (--only-matching) option.
1763    
1764     (f) If -A or -C was used with -c (count only), some lines of context were
1765     accidentally printed for the final match.
1766    
1767     (g) Added the -H (--with-filename) option.
1768    
1769     (h) The combination of options -rh failed to suppress file names for files
1770     that were found from directory arguments.
1771    
1772     (i) Added the -D (--devices) and -d (--directories) options.
1773    
1774     (j) Added the -F (--fixed-strings) option.
1775    
1776     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1777    
1778     (l) Added the --colo(u)r option.
1779    
1780     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1781     is not present by default.
1782    
1783     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1784     items such as (?R) or (?1), when the recursion could match a number of
1785     alternatives. If it matched one of the alternatives, but subsequently,
1786     outside the recursion, there was a failure, the code tried to back up into
1787     the recursion. However, because of the way PCRE is implemented, this is not
1788     possible, and the result was an incorrect result from the match.
1789    
1790     In order to prevent this happening, the specification of recursion has
1791     been changed so that all such subpatterns are automatically treated as
1792     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1793    
1794     4. I had overlooked the fact that, in some locales, there are characters for
1795     which isalpha() is true but neither isupper() nor islower() are true. In
1796     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1797     and ordfeminine) are like this. This affected the treatment of \w and \W
1798     when they appeared in character classes, but not when they appeared outside
1799     a character class. The bit map for "word" characters is now created
1800     separately from the results of isalnum() instead of just taking it from the
1801     upper, lower, and digit maps. (Plus the underscore character, of course.)
1802    
1803     5. The above bug also affected the handling of POSIX character classes such as
1804     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1805     permanent tables. Instead, the bit maps for such a class were previously
1806     created as the appropriate unions of the upper, lower, and digit bitmaps.
1807     Now they are created by subtraction from the [[:word:]] class, which has
1808     its own bitmap.
1809    
1810     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1811     It is created by subtracting the vertical space characters (\x09, \x0a,
1812     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1813     subtraction was done in the overall bitmap for a character class, meaning
1814     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1815     be recognized. This bug has been fixed.
1816    
1817     7. Patches from the folks at Google:
1818    
1819     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1820     real life, but is still worth protecting against".
1821    
1822     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1823     regular expressions".
1824    
1825     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1826     have it.
1827    
1828     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1829     "configure" and the latter not, in order to fix a problem somebody had
1830     with compiling the Arg class on HP-UX.
1831    
1832     (e) Improve the error-handling of the C++ wrapper a little bit.
1833    
1834     (f) New tests for checking recursion limiting.
1835    
1836     8. The pcre_memmove() function, which is used only if the environment does not
1837     have a standard memmove() function (and is therefore rarely compiled),
1838     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1839     returning a result (though PCRE never actually uses the result).
1840    
1841     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1842     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1843     returned instead of calling malloc() with an overflowing number that would
1844     most likely cause subsequent chaos.
1845    
1846     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1847    
1848     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1849     with this option is matched, the nmatch and pmatch options of regexec() are
1850     ignored.
1851    
1852     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1853     provided in case anyone wants to the the POSIX interface with UTF-8
1854     strings.
1855    
1856     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1857     C++ linking (needed for some HP-UX environments).
1858    
1859     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1860     (unused parameter) and in the pcre_printint() function (omitted "default"
1861     switch label when the default is to do nothing).
1862    
1863     15. Added some code to make it possible, when PCRE is compiled as a C++
1864     library, to replace subject pointers for pcre_exec() with a smart pointer
1865     class, thus making it possible to process discontinuous strings.
1866    
1867     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1868     much the same function. They were added by different people who were trying
1869     to make PCRE easy to compile on non-Unix systems. It has been suggested
1870     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1871     for compiling on Windows systems. I have therefore replaced it with
1872     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1873     defaults to "extern" for C or "extern C" for C++, which works fine on
1874     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1875     SCOPE with something explicit in config.h. In addition:
1876    
1877     (a) pcreposix.h still had just "extern" instead of either of these macros;
1878     I have replaced it with PCRE_DATA_SCOPE.
1879    
1880     (b) Functions such as _pcre_xclass(), which are internal to the library,
1881     but external in the C sense, all had PCRE_EXPORT in their definitions.
1882     This is apparently wrong for the Windows case, so I have removed it.
1883     (It makes no difference on Unix-like systems.)
1884    
1885     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1886     of recursive calls to match(). This is different to MATCH_LIMIT because
1887     that limits the total number of calls to match(), not all of which increase
1888     the depth of recursion. Limiting the recursion depth limits the amount of
1889     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1890     when PCRE is compiled, and changed at run time. A patch from Google adds
1891     this functionality to the C++ interface.
1892    
1893     18. Changes to the handling of Unicode character properties:
1894    
1895     (a) Updated the table to Unicode 4.1.0.
1896    
1897     (b) Recognize characters that are not in the table as "Cn" (undefined).
1898    
1899     (c) I revised the way the table is implemented to a much improved format
1900     which includes recognition of ranges. It now supports the ranges that
1901     are defined in UnicodeData.txt, and it also amalgamates other
1902     characters into ranges. This has reduced the number of entries in the
1903     table from around 16,000 to around 3,000, thus reducing its size
1904     considerably. I realized I did not need to use a tree structure after
1905     all - a binary chop search is just as efficient. Having reduced the
1906     number of entries, I extended their size from 6 bytes to 8 bytes to
1907     allow for more data.
1908    
1909     (d) Added support for Unicode script names via properties such as \p{Han}.
1910    
1911     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1912     matching that character.
1913    
1914     20. When matching a repeated Unicode property with a minimum greater than zero,
1915     (for example \pL{2,}), PCRE could look past the end of the subject if it
1916     reached it while seeking the minimum number of characters. This could
1917     happen only if some of the characters were more than one byte long, because
1918     there is a check for at least the minimum number of bytes.
1919    
1920     21. Refactored the implementation of \p and \P so as to be more general, to
1921     allow for more different types of property in future. This has changed the
1922     compiled form incompatibly. Anybody with saved compiled patterns that use
1923     \p or \P will have to recompile them.
1924    
1925     22. Added "Any" and "L&" to the supported property types.
1926    
1927     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1928     but give a compile time error if the value is greater than 0xff.
1929    
1930     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1931     accidentally not being installed or uninstalled.
1932    
1933     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1934     made were to insert the current release number. This seemed silly, because
1935     it made things harder for people building PCRE on systems that don't run
1936     "configure". I have turned pcre.h into a distributed file, no longer built
1937     by "configure", with the version identification directly included. There is
1938     no longer a pcre.h.in file.
1939    
1940     However, this change necessitated a change to the pcre-config script as
1941     well. It is built from pcre-config.in, and one of the substitutions was the
1942     release number. I have updated configure.ac so that ./configure now finds
1943     the release number by grepping pcre.h.
1944    
1945     26. Added the ability to run the tests under valgrind.
1946    
1947    
1948 nigel 85 Version 6.4 05-Sep-05
1949     ---------------------
1950    
1951     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1952     "--" to be printed when multiple files were scanned, even when none of the
1953     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1954     consider it to be a bug, and have restored the previous behaviour.
1955    
1956     2. A couple of code tidies to get rid of compiler warnings.
1957    
1958     3. The pcretest program used to cheat by referring to symbols in the library
1959     whose names begin with _pcre_. These are internal symbols that are not
1960     really supposed to be visible externally, and in some environments it is
1961     possible to suppress them. The cheating is now confined to including
1962     certain files from the library's source, which is a bit cleaner.
1963    
1964     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1965     file's purpose clearer.
1966    
1967     5. Reorganized pcre_ucp_findchar().
1968    
1969    
1970 nigel 83 Version 6.3 15-Aug-05
1971     ---------------------
1972    
1973     1. The file libpcre.pc.in did not have general read permission in the tarball.
1974    
1975     2. There were some problems when building without C++ support:
1976    
1977     (a) If C++ support was not built, "make install" and "make test" still
1978     tried to test it.
1979    
1980     (b) There were problems when the value of CXX was explicitly set. Some
1981     changes have been made to try to fix these, and ...
1982    
1983     (c) --disable-cpp can now be used to explicitly disable C++ support.
1984    
1985     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1986     backslash in a target when C++ was disabled. This confuses some
1987     versions of "make", apparently. Using an intermediate variable solves
1988     this. (Same for CPP_LOBJ.)
1989    
1990     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1991     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1992     necessary on certain architectures.
1993    
1994     4. Added a setting of -export-symbols-regex to the link command to remove
1995     those symbols that are exported in the C sense, but actually are local
1996     within the library, and not documented. Their names all begin with
1997     "_pcre_". This is not a perfect job, because (a) we have to except some
1998     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1999     available (and never for static libraries). I have made a note to try to
2000     find a way round (a) in the future.
2001    
2002    
2003 nigel 81 Version 6.2 01-Aug-05
2004     ---------------------
2005    
2006     1. There was no test for integer overflow of quantifier values. A construction
2007     such as {1111111111111111} would give undefined results. What is worse, if
2008     a minimum quantifier for a parenthesized subpattern overflowed and became
2009     negative, the calculation of the memory size went wrong. This could have
2010     led to memory overwriting.
2011    
2012     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2013    
2014     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2015     operating environments where this matters.
2016    
2017     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2018     PCRE options from within the C++ wrapper.
2019    
2020     5. Named capturing subpatterns were not being correctly counted when a pattern
2021     was compiled. This caused two problems: (a) If there were more than 100
2022     such subpatterns, the calculation of the memory needed for the whole
2023     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2024     back references of the form \12, where the number was greater than 9, were
2025     not recognized as back references, even though there were sufficient
2026     previous subpatterns.
2027    
2028     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2029     versions of gcc, e.g. 2.95.4.
2030    
2031    
2032 nigel 79 Version 6.1 21-Jun-05
2033     ---------------------
2034    
2035     1. There was one reference to the variable "posix" in pcretest.c that was not
2036     surrounded by "#if !defined NOPOSIX".
2037    
2038     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2039     the cross-check on the old pcre_info() function, for the benefit of the
2040     cut-down version of PCRE that is currently imported into Exim.
2041    
2042     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2043     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2044     patterns that start (?i) but I don't think that matters. The use of (?i) is
2045     just an example; this all applies to the other options as well.
2046    
2047     4. Since libtool seems to echo the compile commands it is issuing, the output
2048     from "make" can be reduced a bit by putting "@" in front of each libtool
2049     compile command.
2050    
2051     5. Patch from the folks at Google for configure.in to be a bit more thorough
2052     in checking for a suitable C++ installation before trying to compile the
2053     C++ stuff. This should fix a reported problem when a compiler was present,
2054     but no suitable headers.
2055    
2056     6. The man pages all had just "PCRE" as their title. I have changed them to
2057     be the relevant file name. I have also arranged that these names are
2058     retained in the file doc/pcre.txt, which is a concatenation in text format
2059     of all the man pages except the little individual ones for each function.
2060    
2061     7. The NON-UNIX-USE file had not been updated for the different set of source
2062     files that come with release 6. I also added a few comments about the C++
2063     wrapper.
2064    
2065    
2066 nigel 77 Version 6.0 07-Jun-05
2067     ---------------------
2068    
2069     1. Some minor internal re-organization to help with my DFA experiments.
2070    
2071     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2072     didn't matter for the library itself when fully configured, but did matter
2073     when compiling without UCP support, or within Exim, where the ucp files are
2074     not imported.
2075    
2076     3. Refactoring of the library code to split up the various functions into
2077     different source modules. The addition of the new DFA matching code (see
2078     below) to a single monolithic source would have made it really too
2079     unwieldy, quite apart from causing all the code to be include in a
2080     statically linked application, when only some functions are used. This is
2081     relevant even without the DFA addition now that patterns can be compiled in
2082     one application and matched in another.
2083    
2084     The downside of splitting up is that there have to be some external
2085     functions and data tables that are used internally in different modules of
2086     the library but which are not part of the API. These have all had their
2087     names changed to start with "_pcre_" so that they are unlikely to clash
2088     with other external names.
2089    
2090     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2091     a different (DFA) algorithm. Although it is slower than the original
2092     function, it does have some advantages for certain types of matching
2093     problem.
2094    
2095     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2096     including restarting after a partial match.
2097    
2098     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2099     defined when compiling for Windows was sent to me. I have put it into the
2100     code, though I have no means of testing or verifying it.
2101    
2102     7. Added the pcre_refcount() auxiliary function.
2103    
2104     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2105     match before or at the first newline in the subject string. In pcretest,
2106     the /f option on a pattern can be used to set this.
2107    
2108     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2109     would behave wrongly. This has been present in PCRE since release 4.0.
2110    
2111     10. A number of changes to the pcregrep command:
2112    
2113     (a) Refactored how -x works; insert ^(...)$ instead of setting
2114     PCRE_ANCHORED and checking the length, in preparation for adding
2115     something similar for -w.
2116    
2117     (b) Added the -w (match as a word) option.
2118    
2119     (c) Refactored the way lines are read and buffered so as to have more
2120     than one at a time available.
2121    
2122     (d) Implemented a pcregrep test script.
2123    
2124     (e) Added the -M (multiline match) option. This allows patterns to match
2125     over several lines of the subject. The buffering ensures that at least
2126     8K, or the rest of the document (whichever is the shorter) is available
2127     for matching (and similarly the previous 8K for lookbehind assertions).
2128    
2129     (f) Changed the --help output so that it now says
2130    
2131     -w, --word-regex(p)
2132    
2133     instead of two lines, one with "regex" and the other with "regexp"
2134     because that confused at least one person since the short forms are the
2135     same. (This required a bit of code, as the output is generated
2136     automatically from a table. It wasn't just a text change.)
2137    
2138     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2139     option but starts with a hyphen. Could be a pattern or a path name
2140     starting with a hyphen, for instance.
2141    
2142     (h) "-" can be given as a file name to represent stdin.
2143    
2144     (i) When file names are being printed, "(standard input)" is used for
2145     the standard input, for compatibility with GNU grep. Previously
2146     "<stdin>" was used.
2147    
2148     (j) The option --label=xxx can be used to supply a name to be used for
2149     stdin when file names are being printed. There is no short form.
2150    
2151     (k) Re-factored the options decoding logic because we are going to add
2152     two more options that take data. Such options can now be given in four
2153     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2154    
2155     (l) Added the -A, -B, and -C options for requesting that lines of context
2156     around matches be printed.
2157    
2158     (m) Added the -L option to print the names of files that do not contain
2159     any matching lines, that is, the complement of -l.
2160    
2161     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2162     continue to scan other files.
2163    
2164     (o) The -s option was incorrectly implemented. For compatibility with other
2165     greps, it now suppresses the error message for a non-existent or non-
2166     accessible file (but not the return code). There is a new option called
2167     -q that suppresses the output of matching lines, which was what -s was
2168     previously doing.
2169    
2170     (p) Added --include and --exclude options to specify files for inclusion
2171     and exclusion when recursing.
2172    
2173     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2174     Hopefully, it now does.
2175    
2176     12. Missing cast in pcre_study().
2177    
2178     13. Added an "uninstall" target to the makefile.
2179    
2180     14. Replaced "extern" in the function prototypes in Makefile.in with
2181     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2182     world, but is set differently for Windows.
2183    
2184     15. Added a second compiling function called pcre_compile2(). The only
2185     difference is that it has an extra argument, which is a pointer to an
2186     integer error code. When there is a compile-time failure, this is set
2187     non-zero, in addition to the error test pointer being set to point to an
2188     error message. The new argument may be NULL if no error number is required
2189     (but then you may as well call pcre_compile(), which is now just a
2190     wrapper). This facility is provided because some applications need a
2191     numeric error indication, but it has also enabled me to tidy up the way
2192     compile-time errors are handled in the POSIX wrapper.
2193    
2194     16. Added VPATH=.libs to the makefile; this should help when building with one
2195     prefix path and installing with another. (Or so I'm told by someone who
2196     knows more about this stuff than I do.)
2197    
2198     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2199     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2200     match everything, including newlines. This is not POSIX-compatible, but
2201     somebody wanted the feature. From pcretest it can be activated by using
2202     both the P and the s flags.
2203    
2204     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2205    
2206     19. libpcre.pc was being incorrectly installed as executable.
2207    
2208     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2209     it now also looks for '\r' so that it will work unmodified on Windows.
2210    
2211     21. Added Google's contributed C++ wrapper to the distribution.
2212    
2213     22. Added some untidy missing memory free() calls in pcretest, to keep
2214     Electric Fence happy when testing.
2215    
2216    
2217    
2218 nigel 75 Version 5.0 13-Sep-04
2219     ---------------------
2220    
2221     1. Internal change: literal characters are no longer packed up into items
2222     containing multiple characters in a single byte-string. Each character
2223     is now matched using a separate opcode. However, there may be more than one
2224     byte in the character in UTF-8 mode.
2225    
2226     2. The pcre_callout_block structure has two new fields: pattern_position and
2227     next_item_length. These contain the offset in the pattern to the next match
2228     item, and its length, respectively.
2229    
2230     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2231     insertion of callouts before each pattern item. Added the /C option to
2232     pcretest to make use of this.
2233    
2234     4. On the advice of a Windows user, the lines
2235    
2236     #if defined(_WIN32) || defined(WIN32)
2237     _setmode( _fileno( stdout ), 0x8000 );
2238     #endif /* defined(_WIN32) || defined(WIN32) */
2239    
2240     have been added to the source of pcretest. This apparently does useful
2241     magic in relation to line terminators.
2242    
2243     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2244     for the benefit of those environments where the "b" makes a difference.
2245    
2246     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2247     to know about it. I have put a hack into configure.in that adds in code
2248     to set GCC=yes if CC=icc. This seems to end up at a point in the
2249     generated configure script that is early enough to affect the setting of
2250     compiler options, which is what is needed, but I have no means of testing
2251     whether it really works. (The user who reported this had patched the
2252     generated configure script, which of course I cannot do.)
2253    
2254     LATER: After change 22 below (new libtool files), the configure script
2255     seems to know about icc (and also ecc). Therefore, I have commented out
2256     this hack in configure.in.
2257    
2258     7. Added support for pkg-config (2 patches were sent in).
2259    
2260     8. Negated POSIX character classes that used a combination of internal tables
2261     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2262     [[:^ascii]]. Typically, they would match almost any characters. The other
2263     POSIX classes were not broken in this way.
2264    
2265     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2266     to find the match, as PCRE was deluded into thinking that the match had to
2267     start at the start point or following a newline. The same bug applied to
2268     patterns with negative forward assertions or any backward assertions
2269     preceding ".*" at the start, unless the pattern required a fixed first
2270     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2271    
2272     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2273     starting at the last subject character, bytes beyond the end of the subject
2274     string were read.
2275    
2276     11. Renamed the variable "class" as "classbits" to make life easier for C++
2277     users. (Previously there was a macro definition, but it apparently wasn't
2278     enough.)
2279    
2280     12. Added the new field "tables" to the extra data so that tables can be passed
2281     in at exec time, or the internal tables can be re-selected. This allows
2282     a compiled regex to be saved and re-used at a later time by a different
2283     program that might have everything at different addresses.
2284    
2285     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2286     -R library as well as a -L library.
2287    
2288     14. The debugging options of pcretest (-d on the command line or D on a
2289     pattern) showed incorrect output for anything following an extended class
2290     that contained multibyte characters and which was followed by a quantifier.
2291    
2292     15. Added optional support for general category Unicode character properties
2293     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2294     support. It adds about 90K to the size of the library. The meanings of the
2295     inbuilt class escapes such as \d and \s have NOT been changed.
2296    
2297     16. Updated pcredemo.c to include calls to free() to release the memory for the
2298     compiled pattern.
2299    
2300     17. The generated file chartables.c was being created in the source directory
2301     instead of in the building directory. This caused the build to fail if the
2302     source directory was different from the building directory, and was
2303     read-only.
2304    
2305     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2306     file. No doubt somebody will tell me if they don't make sense... Also added
2307     Dan Mooney's comments about building on OpenVMS.
2308    
2309     19. Added support for partial matching via the PCRE_PARTIAL option for
2310     pcre_exec() and the \P data escape in pcretest.
2311    
2312     20. Extended pcretest with 3 new pattern features:
2313    
2314     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2315     write the compiled pattern to the file whose name is "rest-of-line".
2316     This is a straight binary dump of the data, with the saved pointer to
2317     the character tables forced to be NULL. The study data, if any, is
2318     written too. After writing, pcretest reads a new pattern.
2319    
2320     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2321     compiled pattern from the given file. There must not be any
2322     occurrences of "<" in the file name (pretty unlikely); if there are,
2323     pcretest will instead treat the initial "<" as a pattern delimiter.
2324     After reading in the pattern, pcretest goes on to read data lines as
2325     usual.
2326    
2327     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2328     and 16-bit fields in a compiled pattern, to simulate a pattern that
2329     was compiled on a host of opposite endianness.
2330    
2331     21. The pcre-exec() function can now cope with patterns that were compiled on
2332     hosts of opposite endianness, with this restriction:
2333    
2334     As for any compiled expression that is saved and used later, the tables
2335     pointer field cannot be preserved; the extra_data field in the arguments
2336     to pcre_exec() should be used to pass in a tables address if a value
2337     other than the default internal tables were used at compile time.
2338    
2339     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2340     now diagnosed as an error. Previously, most of the time, a negative number
2341     would have been treated as zero, but if in addition "ovector" was passed as
2342     NULL, a crash could occur.
2343    
2344     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2345     new versions from the libtool 1.5 distribution (the last one is a copy of
2346     a file called libtool.m4). This seems to have fixed the need to patch
2347     "configure" to support Darwin 1.3 (which I used to do). However, I still
2348     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2349     workstation).
2350    
2351     24. Changed the PCRE licence to be the more standard "BSD" licence.
2352    
2353    
2354 nigel 73 Version 4.5 01-Dec-03
2355     ---------------------
2356    
2357     1. There has been some re-arrangement of the code for the match() function so
2358     that it can be compiled in a version that does not call itself recursively.
2359     Instead, it keeps those local variables that need separate instances for
2360     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2361     needs to "recurse". Keeping track of where control must go is done by means
2362     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2363     hide most of the details from the main code, and operates only if
2364     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2365     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2366     operating.
2367    
2368     To make it easier for callers to provide specially tailored get/free
2369     functions for this usage, two new functions, pcre_stack_malloc, and
2370     pcre_stack_free, are used. They are always called in strict stacking order,
2371     and the size of block requested is always the same.
2372    
2373     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2374     PCRE has been compiled to use the stack or the heap for recursion. The
2375     -C option of pcretest uses this to show which version is compiled.
2376    
2377     A new data escape \S, is added to pcretest; it causes the amounts of store
2378     obtained and freed by both kinds of malloc/free at match time to be added
2379     to the output.
2380    
2381     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2382     what's available on my current Linux desktop machine.
2383    
2384     3. When matching a UTF-8 string, the test for a valid string at the start has
2385     been extended. If start_offset is not zero, PCRE now checks that it points
2386     to a byte that is the start of a UTF-8 character. If not, it returns
2387     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2388     this is necessary because there may be backward assertions in the pattern.
2389     When matching the same subject several times, it may save resources to use
2390     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2391    
2392     4. The code for checking the validity of UTF-8 strings has been tightened so
2393     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2394     containing "overlong sequences".
2395    
2396     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2397     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2398     should have been "&", but it just so happened that all the cases this let
2399     through by mistake were picked up later in the function.
2400    
2401     6. I had used a variable called "isblank" - this is a C99 function, causing
2402     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2403    
2404     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2405     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2406     so the version is shown; (c) stop "make test" echoing "./RunTest".
2407    
2408     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2409    
2410     9. The prototype for memmove() for systems that don't have it was using
2411     size_t, but the inclusion of the header that defines size_t was later. I've
2412     moved the #includes for the C headers earlier to avoid this.
2413    
2414     10. Added some adjustments to the code to make it easier to compiler on certain
2415     special systems:
2416    
2417     (a) Some "const" qualifiers were missing.
2418     (b) Added the macro EXPORT before all exported functions; by default this
2419     is defined to be empty.
2420     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2421     that it reads its output file name as an argument instead of writing
2422     to the standard output and assuming this can be redirected.
2423    
2424     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2425     class containing characters with values greater than 255, PCRE compilation
2426     went into a loop.
2427    
2428     12. A recursive reference to a subpattern that was within another subpattern
2429     that had a minimum quantifier of zero caused PCRE to crash. For example,
2430     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2431     recursion. If the recursively-called subpattern itself had a zero repeat,
2432     that was OK.
2433    
2434     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2435     buffer into which it was copied (for escape processing) was still set at
2436     1024, so long lines caused crashes.
2437    
2438     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2439     "internal error: code overflow...". This applied to any character class
2440     that was followed by a possessive quantifier.
2441    
2442     15. Modified the Makefile to add libpcre.la as a prerequisite for
2443     libpcreposix.la because I was told this is needed for a parallel build to
2444     work.
2445    
2446     16. If a pattern that contained .* following optional items at the start was
2447     studied, the wrong optimizing data was generated, leading to matching
2448     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2449     matching string must start with a or b or c. The correct conclusion for
2450     this pattern is that a match can start with any character.
2451    
2452    
2453 nigel 71 Version 4.4 13-Aug-03
2454     ---------------------
2455    
2456     1. In UTF-8 mode, a character class containing characters with values between
2457     127 and 255 was not handled correctly if the compiled pattern was studied.
2458     In fixing this, I have also improved the studying algorithm for such
2459     classes (slightly).
2460    
2461     2. Three internal functions had redundant arguments passed to them. Removal
2462     might give a very teeny performance improvement.
2463    
2464     3. Documentation bug: the value of the capture_top field in a callout is *one
2465     more than* the number of the hightest numbered captured substring.
2466    
2467     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2468     in incorrectly linking with a previously installed version. They now link
2469     explicitly with libpcre.la.
2470    
2471     5. configure.in no longer needs to recognize Cygwin specially.
2472    
2473     6. A problem in pcre.in for Windows platforms is fixed.
2474    
2475     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2476     pcretest, it used to include the size of the study block as part of its
2477     output. Unfortunately, the structure contains a field that has a different
2478     size on different hardware architectures. This meant that the tests that
2479     showed this size failed. As the block is currently always of a fixed size,
2480     this information isn't actually particularly useful in pcretest output, so
2481     I have just removed it.
2482    
2483     8. Three pre-processor statements accidentally did not start in column 1.
2484     Sadly, there are *still* compilers around that complain, even though
2485     standard C has not required this for well over a decade. Sigh.
2486    
2487     9. In pcretest, the code for checking callouts passed small integers in the
2488     callout_data field, which is a void * field. However, some picky compilers
2489     complained about the casts involved for this on 64-bit systems. Now
2490     pcretest passes the address of the small integer instead, which should get
2491     rid of the warnings.
2492    
2493     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2494     both compile and run time, and gives an error if an invalid UTF-8 sequence
2495     is found. There is a option for disabling this check in cases where the
2496     string is known to be correct and/or the maximum performance is wanted.
2497    
2498     11. In response to a bug report, I changed one line in Makefile.in from
2499    
2500     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2501     to
2502     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2503    
2504     to look similar to other lines, but I have no way of telling whether this
2505     is the right thing to do, as I do not use Windows. No doubt I'll get told
2506     if it's wrong...
2507    
2508    
2509 nigel 69 Version 4.3 21-May-03
2510     ---------------------
2511    
2512     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2513     Makefile.
2514    
2515     2. Some refactoring to improve the quality of the code:
2516    
2517     (i) The utf8_table... variables are now declared "const".
2518    
2519     (ii) The code for \cx, which used the "case flipping" table to upper case
2520     lower case letters, now just substracts 32. This is ASCII-specific,
2521     but the whole concept of \cx is ASCII-specific, so it seems
2522     reasonable.
2523    
2524     (iii) PCRE was using its character types table to recognize decimal and
2525     hexadecimal digits in the pattern. This is silly, because it handles
2526     only 0-9, a-f, and A-F, but the character types table is locale-
2527     specific, which means strange things might happen. A private
2528     table is now used for this - though it costs 256 bytes, a table is
2529     much faster than multiple explicit tests. Of course, the standard
2530     character types table is still used for matching digits in subject
2531     strings against \d.
2532    
2533     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2534     ending in _t are). So I've renamed it as ESC_tee.
2535    
2536     3. The first argument for regexec() in the POSIX wrapper should have been
2537     defined as "const".
2538    
2539     4. Changed pcretest to use malloc() for its buffers so that they can be
2540     Electric Fenced for debugging.
2541    
2542     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2543     to read one or more bytes before the start of the subject string. Often this
2544     had no effect on PCRE's behaviour, but in some circumstances it could
2545     provoke a segmentation fault.
2546    
2547     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2548     to try to read one or more bytes before the start of the subject string.
2549    
2550     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2551     UTF-8 support could misbehave in various ways if the subject string
2552     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2553     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2554     back over UTF-8 characters.)
2555    
2556    
2557 nigel 67 Version 4.2 14-Apr-03
2558     ---------------------
2559    
2560     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2561    
2562     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2563     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2564     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2565     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2566     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2567     and BUILD_EXEEXT
2568     Note: automatic setting of the BUILD variables is not yet working
2569     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2570     compile-time but not at link-time
2571     [LINK]: use for linking executables only
2572     make different versions for Windows and non-Windows
2573     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2574     libraries
2575     [LINK_FOR_BUILD]: new variable
2576     [OBJEXT]: use throughout
2577     [EXEEXT]: use throughout
2578     <winshared>: new target
2579     <wininstall>: new target
2580     <dftables.o>: use native compiler
2581     <dftables>: use native linker
2582     <install>: handle Windows platform correctly
2583     <clean>: ditto
2584     <check>: ditto
2585     copy DLL to top builddir before testing
2586    
2587     As part of these changes, -no-undefined was removed again. This was reported
2588     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2589     in any case.
2590    
2591     3. Some tidies to get rid of compiler warnings:
2592    
2593     . In the match_data structure, match_limit was an unsigned long int, whereas
2594     match_call_count was an int. I've made them both unsigned long ints.
2595    
2596     . In pcretest the fact that a const uschar * doesn't automatically cast to
2597     a void * provoked a warning.
2598    
2599     . Turning on some more compiler warnings threw up some "shadow" variables
2600     and a few more missing casts.
2601    
2602     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2603     option, a class that contained a single character with a value between 128
2604     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2605    
2606     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2607     option, a class that contained several characters, but with at least one
2608     whose value was between 128 and 255 caused PCRE to crash.
2609    
2610    
2611 nigel 65 Version 4.1 12-Mar-03
2612     ---------------------
2613 nigel 63
2614 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2615     needed, and a string in dftables.c that was longer than standard compilers are
2616     required to support.
2617    
2618     2. Compiling with Sun's compiler found a few more places where the code could
2619     be tidied up in order to avoid warnings.
2620    
2621     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2622     first of these names is deprecated in the latest Autoconf in favour of the name
2623     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2624     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2625     analogy I have changed it to CFLAGS_FOR_BUILD.
2626    
2627     4. Added -no-undefined to the linking command in the Makefile, because this is
2628     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2629     linking step for the pcreposix library.
2630    
2631     5. PCRE was failing to diagnose the case of two named groups with the same
2632     name.
2633    
2634     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2635     literal character that is needed in the subject for a match, and scans along to
2636     ensure that it is present before embarking on the full matching process. This
2637     saves time in cases of nested unlimited repeats that are never going to match.
2638     Problem: the scan can take a lot of time if the subject is very long (e.g.
2639     megabytes), thus penalizing straightforward matches. It is now done only if the
2640     amount of subject to be scanned is less than 1000 bytes.
2641    
2642     7. A lesser problem with the same optimization is that it was recording the
2643     first character of an anchored pattern as "needed", thus provoking a search
2644     right along the subject, even when the first match of the pattern was going to
2645     fail. The "needed" character is now not set for anchored patterns, unless it
2646     follows something in the pattern that is of non-fixed length. Thus, it still
2647     fulfils its original purpose of finding quick non-matches in cases of nested
2648     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2649    
2650    
2651     Version 4.0 17-Feb-03
2652     ---------------------
2653    
2654 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2655     extended to the end of string, PCRE compiled incorrect data. This could lead to
2656     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2657    
2658     2. Moved to autoconf 2.53 and libtool 1.4.2.
2659    
2660     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2661     the special perltest8 script is no longer needed - all the tests can be run
2662     from a single perltest script.
2663    
2664     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2665     by \s. It has now been removed in PCRE. This means it isn't recognized as
2666     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2667     class [:space:] *does* include VT, thereby creating a mess.
2668    
2669     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2670     space and tab.
2671    
2672     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2673     its new features into the main test script, reducing the number of scripts.
2674    
2675     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2676     were backward compatible, and made the (?i) apply to the whole pattern, as if
2677     /i were given. Now it behaves more logically, and applies the option setting
2678     only to what follows. PCRE has been changed to follow suit. However, if it
2679     finds options settings right at the start of the pattern, it extracts them into
2680     the global options, as before. Thus, they show up in the info data.
2681    
2682     8. Added support for the \Q...\E escape sequence. Characters in between are
2683     treated as literals. This is slightly different from Perl in that $ and @ are
2684     also handled as literals inside the quotes. In Perl, they will cause variable
2685     interpolation. Note the following examples:
2686    
2687     Pattern PCRE matches Perl matches
2688    
2689     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2690     \Qabc\$xyz\E abc\$xyz abc\$xyz
2691     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2692    
2693     For compatibility with Perl, \Q...\E sequences are recognized inside character
2694     classes as well as outside them.
2695    
2696     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2697     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2698     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2699     signed/unsigned warnings.
2700    
2701     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2702     option for pcretest, so I've replaced it by a simple function that does just
2703     that job.
2704    
2705     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2706     "pcregrep -".
2707    
2708     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2709     Java package. This provides some syntactic sugar for simple cases of what my
2710     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2711     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2712     item, you can use this simplified notation. Note that only makes sense with
2713     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2714     greediness, whatever the setting of the PCRE_UNGREEDY option.
2715    
2716     13. A change of greediness default within a pattern was not taking effect at
2717     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2718     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2719     was abstracted outside.
2720    
2721     14. PCRE now supports the \G assertion. It is true when the current matching
2722     position is at the start point of the match. This differs from \A when the
2723     starting offset is non-zero. Used with the /g option of pcretest (or similar
2724     code), it works in the same way as it does for Perl's /g option. If all
2725     alternatives of a regex begin with \G, the expression is anchored to the start
2726     match position, and the "anchored" flag is set in the compiled expression.
2727    
2728     15. Some bugs concerning the handling of certain option changes within patterns
2729     have been fixed. These applied to options other than (?ims). For example,
2730     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2731     been the other way round. Some of this was related to change 7 above.
2732    
2733     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2734     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2735     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2736     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2737    
2738     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2739     mode. Unlike ".", it always matches newline, whatever the setting of
2740     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2741     assertions. Perl allows it, but it doesn't (in general) work because it can't
2742     calculate the length of the lookbehind. At least, that's the case for Perl
2743     5.8.0 - I've been told they are going to document that it doesn't work in
2744     future.
2745    
2746     18. Added an error diagnosis for escapes that PCRE does not support: these are
2747     \L, \l, \N, \P, \p, \U, \u, and \X.
2748    
2749     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2750     reading past the end of the pattern in cases such as /[abcd/.
2751    
2752     20. PCRE was getting more memory than necessary for patterns with classes that
2753     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2754    
2755     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2756     compiling PCRE for use with Virtual Pascal.
2757    
2758     22. Small fix to the Makefile to make it work properly if the build is done
2759     outside the source tree.
2760    
2761     23. Added a new extension: a condition to go with recursion. If a conditional
2762     subpattern starts with (?(R) the "true" branch is used if recursion has
2763     happened, whereas the "false" branch is used only at the top level.
2764    
2765     24. When there was a very long string of literal characters (over 255 bytes
2766     without UTF support, over 250 bytes with UTF support), the computation of how
2767     much memory was required could be incorrect, leading to segfaults or other
2768     strange effects.
2769    
2770     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2771     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2772     there was a subsequent back reference to those brackets. This meant that, for
2773     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2774     possible to check for precisely this case. All we can do is abandon the
2775     optimization if .* occurs inside capturing brackets when there are any back
2776     references whatsoever. (See below for a better fix that came later.)
2777    
2778     26. The handling of the optimization for finding the first character of a
2779     non-anchored pattern, and for finding a character that is required later in the
2780     match were failing in some cases. This didn't break the matching; it just
2781     failed to optimize when it could. The way this is done has been re-implemented.
2782    
2783     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2784    
2785     28. Added a new feature that provides some of the functionality that Perl
2786     provides with (?{...}). The facility is termed a "callout". The way it is done
2787     in PCRE is for the caller to provide an optional function, by setting
2788     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2789     global variable. By default it is unset, which disables all calling out. To get
2790     the function called, the regex must include (?C) at appropriate points. This
2791     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2792     This provides a means of identifying different callout points. When PCRE
2793     reaches such a point in the regex, if pcre_callout has been set, the external
2794     function is called. It is provided with data in a structure called
2795     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2796     matching continues; if it returns a non-zero value, the match at the current
2797     point fails. However, backtracking will occur if possible. [This was changed
2798     later and other features added - see item 49 below.]
2799    
2800     29. pcretest is upgraded to test the callout functionality. It provides a
2801     callout function that displays information. By default, it shows the start of
2802     the match and the current position in the text. There are some new data escapes
2803     to vary what happens:
2804    
2805     \C+ in addition, show current contents of captured substrings
2806     \C- do not supply a callout function
2807     \C!n return 1 when callout number n is reached
2808     \C!n!m return 1 when callout number n is reached for the mth time
2809    
2810     30. If pcregrep was called with the -l option and just a single file name, it
2811     output "<stdin>" if a match was found, instead of the file name.
2812    
2813     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2814     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2815     pcre_exec(). This saves a malloc/free per call. The default value of
2816     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2817     when configuring.
2818    
2819     32. The default maximum size of a compiled pattern is 64K. There have been a
2820     few cases of people hitting this limit. The code now uses macros to handle the
2821     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2822     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2823     configuring. Tests 2 and 5 work only with 2-byte links because they output
2824     debugging information about compiled patterns.
2825    
2826     33. Internal code re-arrangements:
2827    
2828     (a) Moved the debugging function for printing out a compiled regex into
2829     its own source file (printint.c) and used #include to pull it into
2830     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2831     separate copies.
2832    
2833     (b) Defined the list of op-code names for debugging as a macro in
2834     internal.h so that it is next to the definition of the opcodes.
2835    
2836     (c) Defined a table of op-code lengths for simpler skipping along compiled
2837     code. This is again a macro in internal.h so that it is next to the
2838     definition of the opcodes.
2839    
2840     34. Added support for recursive calls to individual subpatterns, along the
2841     lines of Robin Houston's patch (but implemented somewhat differently).
2842    
2843     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2844     allow it to read and process whole directories in Win32. This code was
2845     contributed by Lionel Fourquaux; it has not been tested by me.
2846    
2847     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2848     used to name a group. Names consist of alphanumerics and underscores, and must
2849     be unique. Back references use the syntax (?P=name) and recursive calls use
2850     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2851     numbers. The function pcre_fullinfo() can be used after compilation to extract
2852     a name/number map. There are three relevant calls:
2853    
2854     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2855     PCRE_INFO_NAMECOUNT yields the number of entries
2856     PCRE_INFO_NAMETABLE yields a pointer to the map.
2857    
2858     The map is a vector of fixed-size entries. The size of each entry depends on
2859     the length of the longest name used. The first two bytes of each entry are the
2860     group number, most significant byte first. There follows the corresponding
2861     name, zero terminated. The names are in alphabetical order.
2862    
2863     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2864     case instead of 255. Making it the same both with and without UTF-8 support
2865     means that the same test output works with both.
2866    
2867     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2868     calling malloc() with a zero argument.
2869    
2870     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2871     optimization. I've improved things by keeping a bitmap of backreferences with
2872     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2873     fact referenced, the optimization can be applied. It is unlikely that a
2874     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2875     the match to follow \n) will appear inside brackets with a number greater than
2876     31, but if it does, any back reference > 31 suppresses the optimization.
2877    
2878     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2879     of disabling numbered capturing parentheses. Any opening parenthesis that is
2880     not followed by ? behaves as if it were followed by ?: but named parentheses
2881     can still be used for capturing (and they will acquire numbers in the usual
2882     way).
2883    
2884     41. Redesigned the return codes from the match() function into yes/no/error so
2885     that errors can be passed back from deep inside the nested calls. A malloc
2886     failure while inside a recursive subpattern call now causes the
2887     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2888    
2889     42. It is now possible to set a limit on the number of times the match()
2890     function is called in a call to pcre_exec(). This facility makes it possible to
2891     limit the amount of recursion and backtracking, though not in a directly
2892     obvious way, because the match() function is used in a number of different
2893     circumstances. The count starts from zero for each position in the subject
2894     string (for non-anchored patterns). The default limit is, for compatibility, a
2895     large number, namely 10 000 000. You can change this in two ways:
2896    
2897     (a) When configuring PCRE before making, you can use --with-match-limit=n
2898     to set a default value for the compiled library.
2899    
2900     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2901     a different value is set. See 45 below.
2902    
2903     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2904    
2905     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2906     of things that can be changed at compile time. The first argument specifies
2907     what is wanted and the second points to where the information is to be placed.
2908     The current list of available information is:
2909    
2910     PCRE_CONFIG_UTF8
2911    
2912     The output is an integer that is set to one if UTF-8 support is available;
2913     otherwise it is set to zero.
2914    
2915     PCRE_CONFIG_NEWLINE
2916    
2917     The output is an integer that it set to the value of the code that is used for
2918     newline. It is either LF (10) or CR (13).
2919    
2920     PCRE_CONFIG_LINK_SIZE
2921    
2922     The output is an integer that contains the number of bytes used for internal
2923     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2924    
2925     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2926    
2927     The output is an integer that contains the threshold above which the POSIX
2928     interface uses malloc() for output vectors. See item 31 above.
2929    
2930     PCRE_CONFIG_MATCH_LIMIT
2931    
2932     The output is an unsigned integer that contains the default limit of the number
2933     of match() calls in a pcre_exec() execution. See 42 above.
2934    
2935     44. pcretest has been upgraded by the addition of the -C option. This causes it
2936     to extract all the available output from the new pcre_config() function, and to
2937     output it. The program then exits immediately.
2938    
2939     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2940     order to support additional features. One way would have been to define
2941     pcre_exec2() (for example) with extra arguments, but this would not have been
2942     extensible, and would also have required all calls to the original function to
2943     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2944     is used for passing in "extra" data from pcre_study().
2945    
2946     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2947     contains the following fields:
2948    
2949     flags a bitmap indicating which of the following fields are set
2950     study_data opaque data from pcre_study()
2951     match_limit a way of specifying a limit on match() calls for a specific
2952     call to pcre_exec()
2953     callout_data data for callouts (see 49 below)
2954    
2955     The flag bits are also defined in pcre.h, and are
2956    
2957     PCRE_EXTRA_STUDY_DATA
2958     PCRE_EXTRA_MATCH_LIMIT
2959     PCRE_EXTRA_CALLOUT_DATA
2960    
2961     The pcre_study() function now returns one of these new pcre_extra blocks, with
2962     the actual study data pointed to by the study_data field, and the
2963     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2964     before. That is, this change is entirely upwards-compatible and requires no
2965     change to existing code.
2966    
2967     If you want to pass in additional data to pcre_exec(), you can either place it
2968     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2969     block.
2970    
2971     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2972     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2973     times with different match limits, until it finds the minimum value needed for
2974     pcre_exec() to complete. The value is then output. This can be instructive; for
2975     most simple matches the number is quite small, but for pathological cases it
2976     gets very large very quickly.
2977    
2978     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2979     returns the size of the data block pointed to by the study_data field in a
2980     pcre_extra block, that is, the value that was passed as the argument to
2981     pcre_malloc() when PCRE was getting memory in which to place the information
2982     created by pcre_study(). The fourth argument should point to a size_t variable.
2983     pcretest has been extended so that this information is shown after a successful
2984     pcre_study() call when information about the compiled regex is being displayed.
2985    
2986     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2987     because what follows is always an absolute path. (Later: it turns out that this
2988     is more than cosmetic for MinGW, because it doesn't like empty path
2989     components.)
2990    
2991     49. Some changes have been made to the callout feature (see 28 above):
2992    
2993     (i) A callout function now has three choices for what it returns:
2994    
2995     0 => success, carry on matching
2996     > 0 => failure at this point, but backtrack if possible
2997     < 0 => serious error, return this value from pcre_exec()
2998    
2999     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3000     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3001     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3002     use by callout functions. It will never be used by PCRE itself.
3003    
3004     (ii) The pcre_extra structure (see 45 above) has a void * field called
3005     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3006     pcre_callout_block structure has a field of the same name. The contents of
3007     the field passed in the pcre_extra structure are passed to the callout
3008     function in the corresponding field in the callout block. This makes it
3009     easier to use the same callout-containing regex from multiple threads. For
3010     testing, the pcretest program has a new data escape
3011    
3012     \C*n pass the number n (may be negative) as callout_data
3013    
3014     If the callout function in pcretest receives a non-zero value as
3015     callout_data, it returns that value.
3016    
3017     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3018     there were some redundant $(CFLAGS) in commands that are now specified as
3019     $(LINK), which already includes $(CFLAGS).
3020    
3021     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3022     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3023     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3024     one-byte characters throughout. Note that case-insensitive matching applies
3025     only to characters whose values are less than 256. PCRE doesn't support the
3026     notion of cases for higher-valued characters.
3027    
3028     (i) A character class whose characters are all within 0-255 is handled as
3029     a bit map, and the map is inverted for negative classes. Previously, a
3030     character > 255 always failed to match such a class; however it should
3031     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3032    
3033     (ii) A negated character class with a single character < 255 is coded as
3034     "not this character" (OP_NOT). This wasn't working properly when the test
3035     character was multibyte, either singly or repeated.
3036    
3037     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3038     mode, for example: \x{100}{2,3}.
3039    
3040     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3041     singly or repeated) now correctly test multibyte characters. However,
3042     PCRE doesn't recognize any characters with values greater than 255 as
3043     digits, spaces, or word characters. Such characters always match \D, \S,
3044     and \W, and never match \d, \s, or \w.
3045    
3046     (v) Classes may now contain characters and character ranges with values
3047     greater than 255. For example: [ab\x{100}-\x{400}].
3048    
3049     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3050     PCRE in UTF-8 mode.
3051    
3052     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3053     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3054     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3055     value.)
3056    
3057     53. The single man page has become too large. I have therefore split it up into
3058     a number of separate man pages. These also give rise to individual HTML pages;
3059     these are now put in a separate directory, and there is an index.html page that
3060     lists them all. Some hyperlinking between the pages has been installed.
3061    
3062     54. Added convenience functions for handling named capturing parentheses.
3063    
3064     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3065     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3066     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3067     are faulted.
3068    
3069     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3070     calling configure. These values are used when compiling the dftables.c program
3071     which is run to generate the source of the default character tables. They
3072     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3073     you will need to set these values.
3074    
3075     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3076    
3077    
3078     Version 3.9 02-Jan-02
3079 nigel 61 ---------------------
3080    
3081     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3082    
3083     2. If --disable-static was given, the building process failed when trying to
3084     build pcretest and pcregrep. (For some reason it was using libtool to compile
3085     them, which is not right, as they aren't part of the library.)
3086    
3087    
3088 nigel 59 Version 3.8 18-Dec-01
3089     ---------------------
3090    
3091     1. The experimental UTF-8 code was completely screwed up. It was packing the
3092     bytes in the wrong order. How dumb can you get?
3093    
3094    
3095 nigel 57 Version 3.7 29-Oct-01
3096     ---------------------
3097    
3098     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3099     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3100     this didn't happen under Solaris 8, where I normally test things.
3101    
3102 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3103     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3104     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3105     this fix an hour or so after the initial 3.7 release.)
3106 nigel 57
3107 nigel 59
3108 nigel 55 Version 3.6 23-Oct-01
3109     ---------------------
3110    
3111     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3112     offsets passed as NULL with zero offset count.
3113    
3114     2. The config.guess and config.sub files had not been updated when I moved to
3115     the latest autoconf.
3116    
3117    
3118 nigel 53 Version 3.5 15-Aug-01
3119     ---------------------
3120 nigel 5
3121 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3122     had been forgotten.
3123    
3124     2. By using declared but undefined structures, we can avoid using "void"
3125     definitions in pcre.h while keeping the internal definitions of the structures
3126     private.
3127    
3128     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3129     user point of view, this means that both static and shared libraries are built
3130     by default, but this can be individually controlled. More of the work of
3131     handling this static/shared cases is now inside libtool instead of PCRE's make
3132     file.
3133    
3134     4. The pcretest utility is now installed along with pcregrep because it is
3135     useful for users (to test regexs) and by doing this, it automatically gets
3136     relinked by libtool. The documentation has been turned into a man page, so
3137     there are now .1, .txt, and .html versions in /doc.
3138    
3139     5. Upgrades to pcregrep:
3140     (i) Added long-form option names like gnu grep.
3141     (ii) Added --help to list all options with an explanatory phrase.
3142     (iii) Added -r, --recursive to recurse into sub-directories.
3143     (iv) Added -f, --file to read patterns from a file.
3144    
3145     6. pcre_exec() was referring to its "code" argument before testing that
3146     argument for NULL (and giving an error if it was NULL).
3147    
3148     7. Upgraded Makefile.in to allow for compiling in a different directory from
3149     the source directory.
3150    
3151     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3152     options bits, the pointer it was passed was to an int instead of to an unsigned
3153     long int. This mattered only on 64-bit systems.
3154    
3155     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3156     generated) instead of pcre.in, which it its source. Also made the same change
3157     in several of the .c files.
3158    
3159     10. A new release of gcc defines printf() as a macro, which broke pcretest
3160     because it had an ifdef in the middle of a string argument for printf(). Fixed
3161     by using separate calls to printf().
3162    
3163     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3164     script, to force use of CR or LF instead of \n in the source. On non-Unix
3165     systems, the value can be set in config.h.
3166    
3167     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3168     absolute limit. Changed the text of the error message to make this clear, and
3169     likewise updated the man page.
3170    
3171     13. The limit of 99 on the number of capturing subpatterns has been removed.
3172     The new limit is 65535, which I hope will not be a "real" limit.
3173    
3174    
3175 nigel 51 Version 3.4 22-Aug-00
3176     ---------------------
3177    
3178     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3179    
3180     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3181    
3182    
3183 nigel 49 Version 3.3 01-Aug-00
3184     ---------------------
3185    
3186     1. If an octal character was given, but the value was greater than \377, it
3187     was not getting masked to the least significant bits, as documented. This could
3188     lead to crashes in some systems.
3189    
3190     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3191     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3192    
3193     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3194     These just pass their arguments on to (pcre_free)(), but they are provided
3195     because some uses of PCRE bind it to non-C systems that can call its functions,
3196     but cannot call free() or pcre_free() directly.
3197    
3198     4. Add "make test" as a synonym for "make check". Corrected some comments in
3199     the Makefile.
3200    
3201     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3202     Makefile.
3203    
3204     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3205     command called pgrep for grepping around the active processes.
3206    
3207     7. Added the beginnings of support for UTF-8 character strings.
3208    
3209     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3210     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3211     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3212     out for the ar command.)
3213    
3214    
3215 nigel 47 Version 3.2 12-May-00
3216     ---------------------
3217    
3218     This is purely a bug fixing release.
3219    
3220     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3221     of ZA. This was just one example of several cases that could provoke this bug,
3222     which was introduced by change 9 of version 2.00. The code for breaking
3223     infinite loops after an iteration that matches an empty string was't working
3224     correctly.
3225    
3226     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3227     when matched against abbab (for example). After matching an empty string, it
3228     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3229     caused it to match further down the string than it should.
3230    
3231     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3232     was there because it doesn't seem to be needed, and it causes trouble on some
3233     systems, as it is not a Standard C header. It has been removed.
3234    
3235     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3236     were reported on the Macintosh. The changes were from
3237    
3238     while ((c = *(++ptr)) != 0 && c != '\n');
3239     to
3240     while ((c = *(++ptr)) != 0 && c != '\n') ;
3241    
3242     Totally extraordinary, but if that's what it takes...
3243    
3244     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3245     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3246     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3247     assumes the way PCRE uses memmove() (always moving upwards).
3248    
3249     6. PCRE is being used in one environment where strchr() is not available. There
3250     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3251     faster code anyway.
3252    
3253    
3254 nigel 45 Version 3.1 09-Feb-00
3255     ---------------------
3256    
3257     The only change in this release is the fixing of some bugs in Makefile.in for
3258     the "install" target:
3259    
3260     (1) It was failing to install pcreposix.h.
3261    
3262     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3263    
3264    
3265 nigel 43 Version 3.0 01-Feb-00
3266     ---------------------
3267 nigel 41
3268     1. Add support for the /+ modifier to perltest (to output $` like it does in
3269     pcretest).
3270    
3271     2. Add support for the /g modifier to perltest.
3272    
3273     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3274     matches null strings.
3275    
3276     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3277     pattern. Perl treats empty patterns specially - it reuses the most recent
3278     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3279     effect.
3280    
3281     5. The POSIX interface was broken in that it was just handing over the POSIX
3282     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3283     required a bigger vector, with some working space on the end. This means that
3284     the POSIX wrapper now has to get and free some memory, and copy the results.
3285    
3286 nigel 43 6. Added some simple autoconf support, placing the test data and the
3287     documentation in separate directories, re-organizing some of the
3288     information files, and making it build pcre-config (a GNU standard). Also added
3289     libtool support for building PCRE as a shared library, which is now the
3290     default.
3291 nigel 41
3292 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3293     09 are not valid octal constants. Single digits will be used for minor values
3294     less than 10.
3295    
3296     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3297     existing programs that set these in the POSIX interface can use PCRE without
3298     modification.
3299    
3300     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3301     return all that pcre_info() returns, plus additional data. The pcre_info()
3302     function is retained for compatibility, but is considered to be obsolete.
3303    
3304     10. Added experimental recursion feature (?R) to handle one common case that
3305     Perl 5.6 will be able to do with (?p{...}).
3306    
3307     11. Added support for POSIX character classes like [:alpha:], which Perl is
3308     adopting.
3309    
3310    
3311 nigel 39 Version 2.08 31-Aug-99
3312     ----------------------
3313    
3314     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3315     trying to match at the startoffset position, but instead was moving forward to
3316     the next newline as if a previous match had failed.
3317    
3318     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3319     and could get into a loop if a null string was matched other than at the start
3320     of the subject.
3321    
3322     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3323     be distinguished at compile time, and for completeness also added PCRE_DATE.
3324    
3325     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3326     in GnuWin32 environments.
3327    
3328    
3329 nigel 37 Version 2.07 29-Jul-99
3330     ----------------------
3331    
3332     1. The documentation is now supplied in plain text form and HTML as well as in
3333     the form of man page sources.
3334    
3335     2. C++ compilers don't like assigning (void *) values to other pointer types.
3336     In particular this affects malloc(). Although there is no problem in Standard
3337     C, I've put in casts to keep C++ compilers happy.
3338    
3339     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3340     should be (const char *).
3341    
3342     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3343     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3344     However, I haven't made this a standard facility. The documentation doesn't
3345     mention it, and the Makefile doesn't support it.
3346    
3347     5. The Makefile now contains an "install" target, with editable destinations at
3348     the top of the file. The pcretest program is not installed.
3349    
3350     6. pgrep -V now gives the PCRE version number and date.
3351    
3352     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3353     causing the entire string to be ignored, instead of just the last character.
3354    
3355     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3356     non-matching string, it can take a very, very long time, even for strings of
3357     quite modest length, because of the nested recursion. PCRE now does better in
3358     some of these cases. It does this by remembering the last required literal
3359     character in the pattern, and pre-searching the subject to ensure it is present
3360     before running the real match. In other words, it applies a heuristic to detect
3361     some types of certain failure quickly, and in the above example, if presented
3362     with a string that has no trailing " it gives "no match" very quickly.
3363    
3364     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3365     other alternatives are tried instead.
3366    
3367    
3368 nigel 35 Version 2.06 09-Jun-99
3369     ----------------------
3370    
3371     1. Change pcretest's output for amount of store used to show just the code
3372     space, because the remainder (the data block) varies in size between 32-bit and
3373     64-bit systems.
3374    
3375     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3376     start matching at. This allows lookbehinds to work when searching for multiple
3377     occurrences in a string.
3378    
3379     3. Added additional options to pcretest for testing multiple occurrences:
3380    
3381     /+ outputs the rest of the string that follows a match
3382     /g loops for multiple occurrences, using the new startoffset argument
3383     /G loops for multiple occurrences by passing an incremented pointer
3384    
3385     4. PCRE wasn't doing the "first character" optimization for patterns starting
3386     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3387     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3388     the letter 'x'. On long subject strings, this gives a significant speed-up.
3389    
3390    
3391 nigel 33 Version 2.05 21-Apr-99
3392     ----------------------
3393    
3394     1. Changed the type of magic_number from int to long int so that it works
3395     properly on 16-bit systems.
3396    
3397     2. Fixed a bug which caused patterns starting with .* not to work correctly
3398     when the subject string contained newline characters. PCRE was assuming
3399     anchoring for such patterns in all cases, which is not correct because .* will
3400     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3401     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3402     must be retried after every newline in the subject.
3403    
3404    
3405 nigel 31 Version 2.04 18-Feb-99
3406     ----------------------
3407    
3408     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3409     computation of the store needed to hold the pattern was incorrect (too large).
3410     If such patterns were nested a few deep, this could multiply and become a real
3411     problem.
3412    
3413     2. Added /M option to pcretest to show the memory requirement of a specific
3414     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3415    
3416     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3417     compiled in such a way that the backtracking after subsequent failure was
3418     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3419     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3420    
3421    
3422 nigel 29 Version 2.03 02-Feb-99
3423     ----------------------
3424    
3425     1. Fixed typo and small mistake in man page.
3426    
3427 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3428     LICENCE file containing the conditions.
3429 nigel 29
3430     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3431     Perl, that is the internal \ allows the delimiter to be included in the
3432     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3433     the final delimiter, add \ to the end of the pattern (to test the error).
3434    
3435     4. Added the convenience functions for extracting substrings after a successful
3436     match. Updated pcretest to make it able to test these functions.
3437    
3438    
3439 nigel 27 Version 2.02 14-Jan-99
3440     ----------------------
3441    
3442     1. Initialized the working variables associated with each extraction so that
3443     their saving and restoring doesn't refer to uninitialized store.
3444    
3445     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3446     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3447     fix the problem.
3448    
3449     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3450     calls, and wasn't printing the correct value for compiling calls. Increased the
3451     default value of LOOPREPEAT, and the number of significant figures in the
3452     times.
3453    
3454     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3455    
3456     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3457     a building problem on Windows NT with a FAT file system.
3458    
3459    
3460 nigel 25 Version 2.01 21-Oct-98
3461     ----------------------
3462    
3463     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3464     to character tables built by pcre_maketables() in the current locale. If NULL
3465     is passed, the default tables are used.
3466    
3467    
3468 nigel 23 Version 2.00 24-Sep-98
3469 nigel 21 ----------------------
3470    
3471 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3472     it any more.
3473    
3474     2. Allow quantification of (?>) groups, and make it work correctly.
3475    
3476     3. The first character computation wasn't working for (?>) groups.
3477    
3478     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3479     end of the subject) and add 5.005's \z, which really does match only at the
3480     very end of the subject.
3481    
3482     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3483    
3484     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3485     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3486     localized options. All options to pcre_study() were also removed.
3487    
3488     7. Add other new features from 5.005:
3489    
3490     $(?<= positive lookbehind
3491     $(?<! negative lookbehind
3492     (?imsx-imsx) added the unsetting capability
3493     such a setting is global if at outer level; local otherwise
3494     (?imsx-imsx:) non-capturing groups with option setting
3495     (?(cond)re|re) conditional pattern matching
3496    
3497     A backreference to itself in a repeated group matches the previous
3498     captured string.
3499    
3500     8. General tidying up of studying (both automatic and via "study")
3501     consequential on the addition of new assertions.
3502    
3503     9. As in 5.005, unlimited repeated groups that could match an empty substring
3504     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3505     runtime if any iteration does actually match an empty substring.
3506    
3507     10. Include the RunTest script in the distribution.
3508    
3509     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3510     discrepancies, some of which were old and were also with respect to 5.004. They
3511     have now been fixed.
3512    
3513    
3514     Version 1.09 28-Apr-98
3515     ----------------------
3516    
3517 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3518     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3519     program crashes, or just wrong answers. This did not apply to negated classes
3520     containing more than one character, or to minima other than one.
3521    
3522    
3523 nigel 19 Version 1.08 27-Mar-98
3524     ----------------------
3525    
3526     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3527    
3528     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3529     latter must appear before anything that relies on it in the pattern.
3530    
3531    
3532 nigel 17 Version 1.07 16-Feb-98
3533     ----------------------
3534    
3535     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3536     repeat of a potentially empty string).
3537    
3538    
3539 nigel 15 Version 1.06 23-Jan-98
3540     ----------------------
3541    
3542     1. Added Markus Oberhumer's little patches for C++.
3543    
3544     2. Literal strings longer than 255 characters were broken.
3545    
3546    
3547 nigel 13 Version 1.05 23-Dec-97
3548     ----------------------
3549    
3550     1. Negated character classes containing more than one character were failing if
3551     PCRE_CASELESS was set at run time.
3552    
3553    
3554 nigel 11 Version 1.04 19-Dec-97
3555     ----------------------
3556    
3557     1. Corrected the man page, where some "const" qualifiers had been omitted.
3558    
3559     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3560     input syntax.
3561    
3562     3. Fixed memory leak which occurred when a regex with back references was
3563     matched with an offsets vector that wasn't big enough. The temporary memory
3564     that is used in this case wasn't being freed if the match failed.
3565    
3566     4. Tidied pcretest to ensure it frees memory that it gets.
3567    
3568     5. Temporary memory was being obtained in the case where the passed offsets
3569     vector was exactly big enough.
3570    
3571     6. Corrected definition of offsetof() from change 5 below.
3572    
3573     7. I had screwed up change 6 below and broken the rules for the use of
3574     setjmp(). Now fixed.
3575    
3576    
3577 nigel 9 Version 1.03 18-Dec-97
3578     ----------------------
3579    
3580     1. A erroneous regex with a missing opening parenthesis was correctly
3581     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3582     on some systems.
3583    
3584     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3585     it was reported that one broken compiler failed on the former because "code" is
3586     also an independent variable.
3587    
3588     3. The erroneous regex a[]b caused an array overrun reference.
3589    
3590     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3591     fail on data ending with that character. (It was going on too far, and checking
3592     the next character, typically a binary zero.) This was specific to the
3593     optimized code for single-character negative classes.
3594    
3595     5. Added a contributed patch from the TIN world which does the following:
3596    
3597     + Add an undef for memmove, in case the the system defines a macro for it.
3598    
3599     + Add a definition of offsetof(), in case there isn't one. (I don't know
3600     the reason behind this - offsetof() is part of the ANSI standard - but
3601     it does no harm).
3602    
3603     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3604     most of the places where whitespace preceded '#'. I have given up and
3605     allowed the remaining 2 cases to be at the margin.
3606    
3607     + Rename some variables in pcre to eliminate shadowing. This seems very
3608     pedantic, but does no harm, of course.
3609    
3610     6. Moved the call to setjmp() into its own function, to get rid of warnings
3611     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3612    
3613     7. Constructs such as \d{8,} were compiling into the equivalent of
3614 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3615 nigel 9 outcome, but in this particular case used more store than had been allocated,
3616     which caused the bug to be discovered because it threw up an internal error.
3617    
3618     8. The debugging code in both pcre and pcretest for outputting the compiled
3619     form of a regex was going wrong in the case of back references followed by
3620     curly-bracketed repeats.
3621    
3622    
3623 nigel 7 Version 1.02 12-Dec-97
3624     ----------------------
3625    
3626     1. Typos in pcre.3 and comments in the source fixed.
3627    
3628     2. Applied a contributed patch to get rid of places where it used to remove
3629     'const' from variables, and fixed some signed/unsigned and uninitialized
3630     variable warnings.
3631    
3632     3. Added the "runtest" target to Makefile.
3633    
3634     4. Set default compiler flag to -O2 rather than just -O.
3635    
3636    
3637 nigel 5 Version 1.01 19-Nov-97
3638     ----------------------
3639    
3640     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3641     like /([ab]*)*/, that is, for classes with more than one character in them.
3642    
3643     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3644     as /((?>a*))*/ (a PCRE_EXTRA facility).
3645    
3646    
3647     Version 1.00 18-Nov-97
3648     ----------------------
3649    
3650     1. Added compile-time macros to support systems such as SunOS4 which don't have
3651     memmove() or strerror() but have other things that can be used instead.
3652    
3653     2. Arranged that "make clean" removes the executables.
3654    
3655    
3656 nigel 3 Version 0.99 27-Oct-97
3657     ----------------------
3658    
3659     1. Fixed bug in code for optimizing classes with only one character. It was
3660     initializing a 32-byte map regardless, which could cause it to run off the end
3661     of the memory it had got.
3662    
3663     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3664    
3665    
3666     Version 0.98 22-Oct-97
3667     ----------------------
3668    
3669     1. Fixed bug in code for handling temporary memory usage when there are more
3670     back references than supplied space in the ovector. This could cause segfaults.
3671    
3672    
3673     Version 0.97 21-Oct-97
3674     ----------------------
3675    
3676     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3677    
3678     2. Optimized negated single characters not to use a bit map.
3679    
3680     3. Brought error texts together as macro definitions; clarified some of them;
3681     fixed one that was wrong - it said "range out of order" when it meant "invalid
3682     escape sequence".
3683    
3684     4. Changed some char * arguments to const char *.
3685    
3686     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3687    
3688     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3689     pcretest.
3690    
3691    
3692     Version 0.96 16-Oct-97
3693     ----------------------
3694    
3695     1. Added a simple "pgrep" utility to the distribution.
3696    
3697     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3698     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3699     where "ddd" means "one or more decimal digits".
3700    
3701     3. Fixed serious bug. If a pattern had a back reference, but the call to
3702     pcre_exec() didn't supply a large enough ovector to record the related
3703     identifying subpattern, the match always failed. PCRE now remembers the number
3704     of the largest back reference, and gets some temporary memory in which to save
3705     the offsets during matching if necessary, in order to ensure that
3706     backreferences always work.
3707    
3708     4. Increased the compatibility with Perl in a number of ways:
3709    
3710     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3711     to request this handling. The option can be set at compile or exec time.
3712    
3713     (b) $ matches before a terminating newline by default; an option
3714     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3715     mode). The option can be set at compile or exec time.
3716    
3717     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3718     the same as Perl's. If the decimal number it represents is less than 10
3719     or there aren't that many previous left capturing parentheses, an octal
3720     escape is read. Inside a character class, it's always an octal escape,
3721     even if it is a single digit.
3722    
3723     (d) An escaped but undefined alphabetic character is taken as a literal,
3724     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3725     escapes.
3726    
3727     (e) {0} is now permitted. (The previous item is removed from the compiled
3728     pattern).
3729    
3730     5. Changed all the names of code files so that the basic parts are no longer
3731     than 10 characters, and abolished the teeny "globals.c" file.
3732    
3733     6. Changed the handling of character classes; they are now done with a 32-byte
3734     bit map always.
3735    
3736     7. Added the -d and /D options to pcretest to make it possible to look at the
3737     internals of compilation without having to recompile pcre.
3738    
3739    
3740     Version 0.95 23-Sep-97
3741     ----------------------
3742    
3743     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3744     \x20 at the start of a run of normal characters. These were being treated as
3745     real characters, instead of the source characters being re-checked.
3746    
3747    
3748     Version 0.94 18-Sep-97
3749     ----------------------
3750    
3751     1. The functions are now thread-safe, with the caveat that the global variables
3752     containing pointers to malloc() and free() or alternative functions are the
3753     same for all threads.
3754    
3755     2. Get pcre_study() to generate a bitmap of initial characters for non-
3756     anchored patterns when this is possible, and use it if passed to pcre_exec().
3757    
3758    
3759     Version 0.93 15-Sep-97
3760     ----------------------
3761    
3762     1. /(b)|(:+)/ was computing an incorrect first character.
3763    
3764     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3765     but not actually doing anything yet.
3766    
3767     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3768     as Perl does (e.g. [-az] or [az-]).
3769    
3770     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3771     all possible positions.
3772    
3773     5. Split up into different modules to avoid including unneeded functions in a
3774     compiled binary. However, compile and exec are still in one module. The "study"
3775     function is split off.
3776    
3777     6. The character tables are now in a separate module whose source is generated
3778     by an auxiliary program - but can then be edited by hand if required. There are
3779     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3780     toupper() in the code.
3781    
3782     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3783     make them global. Abolish the function for setting them, as the caller can now
3784     set them directly.
3785    
3786    
3787     Version 0.92 11-Sep-97
3788     ----------------------
3789    
3790     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character