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Revision 619 - (show annotations)
Sun Jul 17 13:23:14 2011 UTC (10 years, 3 months ago) by ph10
File size: 205974 byte(s)
Fix capturing not happening in assertion conditions.
1 ChangeLog for PCRE
2 ------------------
4 Version 8.13 30-Apr-2011
5 ------------------------
7 1. The Unicode data tables have been updated to Unicode 6.0.0.
9 2. Two minor typos in pcre_internal.h have been fixed.
11 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
12 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
13 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
15 4. There were a number of related bugs in the code for matching backrefences
16 caselessly in UTF-8 mode when codes for the characters concerned were
17 different numbers of bytes. For example, U+023A and U+2C65 are an upper
18 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
19 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
20 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
21 2-byte code at the end of the subject (it thought there wasn't enough data
22 left).
24 5. Comprehensive information about what went wrong is now returned by
25 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
26 as the output vector has at least 2 elements. The offset of the start of
27 the failing character and a reason code are placed in the vector.
29 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
30 now returned is for the first byte of the failing character, instead of the
31 last byte inspected. This is an incompatible change, but I hope it is small
32 enough not to be a problem. It makes the returned offset consistent with
33 pcre_exec() and pcre_dfa_exec().
35 7. pcretest now gives a text phrase as well as the error number when
36 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
37 failure, the offset and reason code are output.
39 8. When \R was used with a maximizing quantifier it failed to skip backwards
40 over a \r\n pair if the subsequent match failed. Instead, it just skipped
41 back over a single character (\n). This seems wrong (because it treated the
42 two characters as a single entity when going forwards), conflicts with the
43 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
44 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
45 has been changed.
47 9. Some internal refactoring has changed the processing so that the handling
48 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
49 time (the PCRE_DOTALL option was changed this way some time ago: version
50 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
51 which was always a bit of a fudge. It also means that there is one less
52 argument for the match() function, which reduces its stack requirements
53 slightly. This change also fixes an incompatibility with Perl: the pattern
54 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
56 10. More internal refactoring has drastically reduced the number of recursive
57 calls to match() for possessively repeated groups such as (abc)++ when
58 using pcre_exec().
60 11. While implementing 10, a number of bugs in the handling of groups were
61 discovered and fixed:
63 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
64 (a|)*(?1) gave a compile-time internal error.
65 ((a|)+)+ did not notice that the outer group could match an empty string.
66 (^a|^)+ was not marked as anchored.
67 (.*a|.*)+ was not marked as matching at start or after a newline.
69 12. Yet more internal refactoring has removed another argument from the match()
70 function. Special calls to this function are now indicated by setting a
71 value in a variable in the "match data" data block.
73 13. Be more explicit in pcre_study() instead of relying on "default" for
74 opcodes that mean there is no starting character; this means that when new
75 ones are added and accidentally left out of pcre_study(), testing should
76 pick them up.
78 14. The -s option of pcretest has been documented for ages as being an old
79 synonym of -m (show memory usage). I have changed it to mean "force study
80 for every regex", that is, assume /S for every regex. This is similar to -i
81 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
82 using it. It makes it easier to run collections of tests with and without
83 study enabled, and thereby test pcre_study() more easily. All the standard
84 tests are now run with and without -s (but some patterns can be marked as
85 "never study" - see 20 below).
87 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
88 restoration of the capturing data to the outer values was not happening
89 correctly.
91 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
92 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
93 pattern had matched an empty string, and so incorrectly returned a no
94 match.
96 17. There was optimizing code for the last branch of non-capturing parentheses,
97 and also for the obeyed branch of a conditional subexpression, which used
98 tail recursion to cut down on stack usage. Unfortunately, not that there is
99 the possibility of (*THEN) occurring in these branches, tail recursion is
100 no longer possible because the return has to be checked for (*THEN). These
101 two optimizations have therefore been removed.
103 18. If a pattern containing \R was studied, it was assumed that \R always
104 matched two bytes, thus causing the minimum subject length to be
105 incorrectly computed because \R can also match just one byte.
107 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
108 was incorrectly computed.
110 20. If /S is present twice on a test pattern in pcretest input, it *disables*
111 studying, thereby overriding the use of -s on the command line. This is
112 necessary for one or two tests to keep the output identical in both cases.
114 21. When (*ACCEPT) was used in an assertion that matched an empty string and
115 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
117 22. When an atomic group that contained a capturing parenthesis was
118 successfully matched, but the branch in which it appeared failed, the
119 capturing was not being forgotten if a higher numbered group was later
120 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
121 group 1 to "a", when in fact it should be unset. This applied to multi-
122 branched capturing and non-capturing groups, repeated or not, and also to
123 positive assertions (capturing in negative assertions is not well defined
124 in PCRE) and also to nested atomic groups.
126 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
127 subject after a captured substring (to make it easier to tell which of a
128 number of identical substrings has been captured).
130 24. The way atomic groups are processed by pcre_exec() has been changed so that
131 if they are repeated, backtracking one repetition now resets captured
132 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
133 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
134 "aaa". Previously, it would have been "a". As part of this code
135 refactoring, the way recursive calls are handled has also been changed.
137 24. If an assertion condition captured any substrings, they were not passed
138 back unless some other capturing happened later. For example, if
139 (?(?=(a))a) was matched against "a", no capturing was returned.
142 Version 8.12 15-Jan-2011
143 ------------------------
145 1. Fixed some typos in the markup of the man pages, and wrote a script that
146 checks for such things as part of the documentation building process.
148 2. On a big-endian 64-bit system, pcregrep did not correctly process the
149 --match-limit and --recursion-limit options (added for 8.11). In
150 particular, this made one of the standard tests fail. (The integer value
151 went into the wrong half of a long int.)
153 3. If the --colour option was given to pcregrep with -v (invert match), it
154 did strange things, either producing crazy output, or crashing. It should,
155 of course, ignore a request for colour when reporting lines that do not
156 match.
158 4. Another pcregrep bug caused similar problems if --colour was specified with
159 -M (multiline) and the pattern match finished with a line ending.
161 5. In pcregrep, when a pattern that ended with a literal newline sequence was
162 matched in multiline mode, the following line was shown as part of the
163 match. This seems wrong, so I have changed it.
165 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
166 the check for further matches in the same line (so they could be coloured)
167 to overrun the end of the current line. If another match was found, it was
168 incorrectly shown (and then shown again when found in the next line).
170 7. If pcregrep was compiled under Windows, there was a reference to the
171 function pcregrep_exit() before it was defined. I am assuming this was
172 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
173 reported by a user. I've moved the definition above the reference.
176 Version 8.11 10-Dec-2010
177 ------------------------
179 1. (*THEN) was not working properly if there were untried alternatives prior
180 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
181 backtracked to try for "b" instead of moving to the next alternative branch
182 at the same level (in this case, to look for "c"). The Perl documentation
183 is clear that when (*THEN) is backtracked onto, it goes to the "next
184 alternative in the innermost enclosing group".
186 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
187 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
188 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
189 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
190 (*THEN).
192 3. If \s appeared in a character class, it removed the VT character from
193 the class, even if it had been included by some previous item, for example
194 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
195 of \s, but is part of the POSIX "space" class.)
197 4. A partial match never returns an empty string (because you can always
198 match an empty string at the end of the subject); however the checking for
199 an empty string was starting at the "start of match" point. This has been
200 changed to the "earliest inspected character" point, because the returned
201 data for a partial match starts at this character. This means that, for
202 example, /(?<=abc)def/ gives a partial match for the subject "abc"
203 (previously it gave "no match").
205 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
206 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
207 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
208 has an implication that the given string is incomplete (because a partial
209 match is preferred over a full match). For this reason, these items now
210 give a partial match in this situation. [Aside: previously, the one case
211 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
212 match rather than a full match, which was wrong by the old rules, but is
213 now correct.]
215 6. There was a bug in the handling of #-introduced comments, recognized when
216 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
217 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
218 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
219 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
220 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
221 places in pcre_compile().
223 7. Related to (6) above, when pcre_compile() was skipping #-introduced
224 comments when looking ahead for named forward references to subpatterns,
225 the only newline sequence it recognized was NL. It now handles newlines
226 according to the set newline convention.
228 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
229 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
230 cater for a lack of strerror(). These oversights have been fixed.
232 9. Added --match-limit and --recursion-limit to pcregrep.
234 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
236 11. When the -o option was used, pcregrep was setting a return code of 1, even
237 when matches were found, and --line-buffered was not being honoured.
239 12. Added an optional parentheses number to the -o and --only-matching options
240 of pcregrep.
242 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
243 can match an empty string. The code to do it in pcretest and pcredemo
244 needed fixing:
246 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
247 only one byte after an empty string match just before CRLF (this case
248 just got forgotten; "any" and "anycrlf" were OK).
250 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
251 mode when an empty string match preceded an ASCII character followed by
252 a non-ASCII character. (The code for advancing by one character rather
253 than one byte was nonsense.)
255 (c) The pcredemo.c sample program did not have any code at all to handle
256 the cases when CRLF is a valid newline sequence.
258 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
259 as a starting offset was within the subject string. There is now a new
260 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
261 negative or greater than the length of the string. In order to test this,
262 pcretest is extended to allow the setting of negative starting offsets.
264 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
265 starting offset points to the beginning of a UTF-8 character was
266 unnecessarily clumsy. I tidied it up.
268 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
269 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
271 17. Nobody had reported that the --include_dir option, which was added in
272 release 7.7 should have been called --include-dir (hyphen, not underscore)
273 for compatibility with GNU grep. I have changed it to --include-dir, but
274 left --include_dir as an undocumented synonym, and the same for
275 --exclude-dir, though that is not available in GNU grep, at least as of
276 release 2.5.4.
278 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
279 characters from a string of bytes) have been redefined so as not to use
280 loops, in order to improve performance in some environments. At the same
281 time, I abstracted some of the common code into auxiliary macros to save
282 repetition (this should not affect the compiled code).
284 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
285 compile-time error is now given if \c is not followed by an ASCII
286 character, that is, a byte less than 128. (In EBCDIC mode, the code is
287 different, and any byte value is allowed.)
289 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
290 START_OPTIMIZE option, which is now allowed at compile time - but just
291 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
292 to pcregrep and other applications that have no direct access to PCRE
293 options. The new /Y option in pcretest sets this option when calling
294 pcre_compile().
296 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
297 back references. Groups containing recursive back references were forced to
298 be atomic by that change, but in the case of named groups, the amount of
299 memory required was incorrectly computed, leading to "Failed: internal
300 error: code overflow". This has been fixed.
302 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
303 pcretest.c, to avoid build problems in some Borland environments.
306 Version 8.10 25-Jun-2010
307 ------------------------
309 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
310 THEN.
312 2. (*ACCEPT) was not working when inside an atomic group.
314 3. Inside a character class, \B is treated as a literal by default, but
315 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
316 causes the error). The code is unchanged, but I tidied the documentation.
318 4. Inside a character class, PCRE always treated \R and \X as literals,
319 whereas Perl faults them if its -w option is set. I have changed PCRE so
320 that it faults them when PCRE_EXTRA is set.
322 5. Added support for \N, which always matches any character other than
323 newline. (It is the same as "." when PCRE_DOTALL is not set.)
325 6. When compiling pcregrep with newer versions of gcc which may have
326 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
327 declared with attribute warn_unused_result" were given. Just casting the
328 result to (void) does not stop the warnings; a more elaborate fudge is
329 needed. I've used a macro to implement this.
331 7. Minor change to pcretest.c to avoid a compiler warning.
333 8. Added four artifical Unicode properties to help with an option to make
334 \s etc use properties (see next item). The new properties are: Xan
335 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
337 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
338 use Unicode properties. (*UCP) at the start of a pattern can be used to set
339 this option. Modified pcretest to add /W to test this facility. Added
340 REG_UCP to make it available via the POSIX interface.
342 10. Added --line-buffered to pcregrep.
344 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
345 studied, and the match started with a letter with a code point greater than
346 127 whose first byte was different to the first byte of the other case of
347 the letter, the other case of this starting letter was not recognized
348 (#976).
350 12. If a pattern that was studied started with a repeated Unicode property
351 test, for example, \p{Nd}+, there was the theoretical possibility of
352 setting up an incorrect bitmap of starting bytes, but fortunately it could
353 not have actually happened in practice until change 8 above was made (it
354 added property types that matched character-matching opcodes).
356 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
357 possible starting bytes for non-anchored patterns.
359 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
360 \R, and also a number of cases that involve Unicode properties, both
361 explicit and implicit when PCRE_UCP is set.
363 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
364 input, it could crash or give wrong results if characters with values
365 greater than 0xc0 were present in the subject string. (Detail: it assumed
366 UTF-8 input when processing these items.)
368 16. Added a lot of (int) casts to avoid compiler warnings in systems where
369 size_t is 64-bit (#991).
371 17. Added a check for running out of memory when PCRE is compiled with
372 --disable-stack-for-recursion (#990).
374 18. If the last data line in a file for pcretest does not have a newline on
375 the end, a newline was missing in the output.
377 19. The default pcre_chartables.c file recognizes only ASCII characters (values
378 less than 128) in its various bitmaps. However, there is a facility for
379 generating tables according to the current locale when PCRE is compiled. It
380 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
381 characters, are recognized by isspace() and therefore were getting set in
382 these tables, and indeed these tables seem to approximate to ISO 8859. This
383 caused a problem in UTF-8 mode when pcre_study() was used to create a list
384 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
385 which of course cannot start UTF-8 characters. I have changed the code so
386 that only real ASCII characters (less than 128) and the correct starting
387 bytes for UTF-8 encodings are set for characters greater than 127 when in
388 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
389 altogether.)
391 20. Added the /T option to pcretest so as to be able to run tests with non-
392 standard character tables, thus making it possible to include the tests
393 used for 19 above in the standard set of tests.
395 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
396 reference to a subpattern the other side of a comment that contains an
397 opening parenthesis caused either an internal compiling error, or a
398 reference to the wrong subpattern.
401 Version 8.02 19-Mar-2010
402 ------------------------
404 1. The Unicode data tables have been updated to Unicode 5.2.0.
406 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
407 configured.
409 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
410 original author of that file, following a query about its status.
412 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
413 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
415 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
416 quantifier applied to a forward-referencing subroutine call, could compile
417 incorrect code or give the error "internal error: previously-checked
418 referenced subpattern not found".
420 6. Both MS Visual Studio and Symbian OS have problems with initializing
421 variables to point to external functions. For these systems, therefore,
422 pcre_malloc etc. are now initialized to local functions that call the
423 relevant global functions.
425 7. There were two entries missing in the vectors called coptable and poptable
426 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
427 I've fixed the data, and added a kludgy way of testing at compile time that
428 the lengths are correct (equal to the number of opcodes).
430 8. Following on from 7, I added a similar kludge to check the length of the
431 eint vector in pcreposix.c.
433 9. Error texts for pcre_compile() are held as one long string to avoid too
434 much relocation at load time. To find a text, the string is searched,
435 counting zeros. There was no check for running off the end of the string,
436 which could happen if a new error number was added without updating the
437 string.
439 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
441 11. \K was not working if it appeared in an atomic group or in a group that
442 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
443 \K is "not well defined" if used in an assertion. PCRE now accepts it if
444 the assertion is positive, but not if it is negative.
446 12. Change 11 fortuitously reduced the size of the stack frame used in the
447 "match()" function of pcre_exec.c by one pointer. Forthcoming
448 implementation of support for (*MARK) will need an extra pointer on the
449 stack; I have reserved it now, so that the stack frame size does not
450 decrease.
452 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
453 item in branch that calls a recursion is a subroutine call - as in the
454 second branch in the above example - was incorrectly given the compile-
455 time error "recursive call could loop indefinitely" because pcre_compile()
456 was not correctly checking the subroutine for matching a non-empty string.
458 14. The checks for overrunning compiling workspace could trigger after an
459 overrun had occurred. This is a "should never occur" error, but it can be
460 triggered by pathological patterns such as hundreds of nested parentheses.
461 The checks now trigger 100 bytes before the end of the workspace.
463 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
466 Version 8.01 19-Jan-2010
467 ------------------------
469 1. If a pattern contained a conditional subpattern with only one branch (in
470 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
471 computed the wrong minimum data length (which is of course zero for such
472 subpatterns). This could cause incorrect "no match" results.
474 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
475 the pattern is reset in the first branch, pcre_compile() failed with
476 "internal error: code overflow at offset...". This happened only when
477 the reset was to the original external option setting. (An optimization
478 abstracts leading options settings into an external setting, which was the
479 cause of this.)
481 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
482 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
483 assertion pattern did not match (meaning that the assertion was true), it
484 was incorrectly treated as false if the SKIP had been reached during the
485 matching. This also applied to assertions used as conditions.
487 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
488 assertion subpattern, including such a pattern used as a condition,
489 unpredictable results occurred, instead of the error return
492 5. The C++ GlobalReplace function was not working like Perl for the special
493 situation when an empty string is matched. It now does the fancy magic
494 stuff that is necessary.
496 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
497 removed. (These were left over from very, very early versions of PCRE.)
499 7. Some cosmetic changes to the code to make life easier when compiling it
500 as part of something else:
502 (a) Change DEBUG to PCRE_DEBUG.
504 (b) In pcre_compile(), rename the member of the "branch_chain" structure
505 called "current" as "current_branch", to prevent a collision with the
506 Linux macro when compiled as a kernel module.
508 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
509 prevent a collision with the Linux macro when compiled as a kernel
510 module.
512 8. In pcre_compile() there are some checks for integer overflows that used to
513 cast potentially large values to (double). This has been changed to that
514 when building, a check for int64_t is made, and if it is found, it is used
515 instead, thus avoiding the use of floating point arithmetic. (There is no
516 other use of FP in PCRE.) If int64_t is not found, the fallback is to
517 double.
519 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
520 2005 (difference between two addresses compared to an unsigned value).
522 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
523 custom one, because of the following reported problem in Windows:
525 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
526 under Win32.
527 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
528 therefore missing the function definition.
529 - The compiler thus generates a "C" signature for the test function.
530 - The linker fails to find the "C" function.
531 - PCRE fails to configure if asked to do so against libbz2.
533 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
534 messages were output:
536 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
537 rerunning libtoolize, to keep the correct libtool macros in-tree.
538 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
540 I have done both of these things.
542 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
543 most of the time, it *can* run out if it is given a pattern that contains a
544 runaway infinite recursion. I updated the discussion in the pcrestack man
545 page.
547 13. Now that we have gone to the x.xx style of version numbers, the minor
548 version may start with zero. Using 08 or 09 is a bad idea because users
549 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
550 interpreted as invalid octal numbers. I've updated the previous comment in
551 configure.ac, and also added a check that gives an error if 08 or 09 are
552 used.
554 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
555 causing partial matching to fail when the end of the subject matched \W
556 in a UTF-8 pattern where \W was quantified with a minimum of 3.
558 15. There were some discrepancies between the declarations in pcre_internal.h
559 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
560 their definitions. The declarations used "const uschar *" and the
561 definitions used USPTR. Even though USPTR is normally defined as "const
562 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
563 reported that: "This difference in casting confuses some C++ compilers, for
564 example, SunCC recognizes above declarations as different functions and
565 generates broken code for hbpcre." I have changed the declarations to use
566 USPTR.
568 16. GNU libtool is named differently on some systems. The autogen.sh script now
569 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
570 (FreeBSD).
572 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
573 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
574 comment: "Figure out how to create a longlong from a string: strtoll and
575 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
576 instance, but it only takes 2 args instead of 3!"
578 18. A subtle bug concerned with back references has been fixed by a change of
579 specification, with a corresponding code fix. A pattern such as
580 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
581 refers, was giving matches when it shouldn't. For example, xa=xaaa would
582 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
583 same bug. Such groups have to be quantified to be useful, or contained
584 inside another quantified group. (If there's no repetition, the reference
585 can never match.) The problem arises because, having left the group and
586 moved on to the rest of the pattern, a later failure that backtracks into
587 the group uses the captured value from the final iteration of the group
588 rather than the correct earlier one. I have fixed this in PCRE by forcing
589 any group that contains a reference to itself to be an atomic group; that
590 is, there cannot be any backtracking into it once it has completed. This is
591 similar to recursive and subroutine calls.
594 Version 8.00 19-Oct-09
595 ----------------------
597 1. The table for translating pcre_compile() error codes into POSIX error codes
598 was out-of-date, and there was no check on the pcre_compile() error code
599 being within the table. This could lead to an OK return being given in
600 error.
602 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
603 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
604 in a Windows environment.
606 3. The pcregrep --count option prints the count for each file even when it is
607 zero, as does GNU grep. However, pcregrep was also printing all files when
608 --files-with-matches was added. Now, when both options are given, it prints
609 counts only for those files that have at least one match. (GNU grep just
610 prints the file name in this circumstance, but including the count seems
611 more useful - otherwise, why use --count?) Also ensured that the
612 combination -clh just lists non-zero counts, with no names.
614 4. The long form of the pcregrep -F option was incorrectly implemented as
615 --fixed_strings instead of --fixed-strings. This is an incompatible change,
616 but it seems right to fix it, and I didn't think it was worth preserving
617 the old behaviour.
619 5. The command line items --regex=pattern and --regexp=pattern were not
620 recognized by pcregrep, which required --regex pattern or --regexp pattern
621 (with a space rather than an '='). The man page documented the '=' forms,
622 which are compatible with GNU grep; these now work.
624 6. No libpcreposix.pc file was created for pkg-config; there was just
625 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
627 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
628 when UCP support is not needed, by modifying the Python script that
629 generates it from Unicode data files. This should not matter if the module
630 is correctly used as a library, but I received one complaint about 50K of
631 unwanted data. My guess is that the person linked everything into his
632 program rather than using a library. Anyway, it does no harm.
634 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
635 was a minimum greater than 1 for a wide character in a possessive
636 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
637 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
638 character. Chaos in the form of incorrect output or a compiling loop could
639 result.
641 9. The restrictions on what a pattern can contain when partial matching is
642 requested for pcre_exec() have been removed. All patterns can now be
643 partially matched by this function. In addition, if there are at least two
644 slots in the offset vector, the offset of the earliest inspected character
645 for the match and the offset of the end of the subject are set in them when
646 PCRE_ERROR_PARTIAL is returned.
648 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
649 synonymous with PCRE_PARTIAL, for backwards compatibility, and
650 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
651 and may be more useful for multi-segment matching.
653 11. Partial matching with pcre_exec() is now more intuitive. A partial match
654 used to be given if ever the end of the subject was reached; now it is
655 given only if matching could not proceed because another character was
656 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
657 string "Z", which now yields "no match" instead of "partial match". In the
658 case of pcre_dfa_exec(), "no match" is given if every matching path for the
659 final character ended with (*FAIL).
661 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
662 if the pattern had a "must contain" character that was already found in the
663 earlier partial match, unless partial matching was again requested. For
664 example, with the pattern /dog.(body)?/, the "must contain" character is
665 "g". If the first part-match was for the string "dog", restarting with
666 "sbody" failed. This bug has been fixed.
668 13. The string returned by pcre_dfa_exec() after a partial match has been
669 changed so that it starts at the first inspected character rather than the
670 first character of the match. This makes a difference only if the pattern
671 starts with a lookbehind assertion or \b or \B (\K is not supported by
672 pcre_dfa_exec()). It's an incompatible change, but it makes the two
673 matching functions compatible, and I think it's the right thing to do.
675 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
676 so that the demonstration program is easily available in environments where
677 PCRE has not been installed from source.
679 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
680 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
681 library.
683 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
684 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
685 is not the first non-POSIX option to be added. Clearly some people find
686 these options useful.
688 17. If a caller to the POSIX matching function regexec() passes a non-zero
689 value for nmatch with a NULL value for pmatch, the value of
690 nmatch is forced to zero.
692 18. RunGrepTest did not have a test for the availability of the -u option of
693 the diff command, as RunTest does. It now checks in the same way as
694 RunTest, and also checks for the -b option.
696 19. If an odd number of negated classes containing just a single character
697 interposed, within parentheses, between a forward reference to a named
698 subpattern and the definition of the subpattern, compilation crashed with
699 an internal error, complaining that it could not find the referenced
700 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
701 [The bug was that it was starting one character too far in when skipping
702 over the character class, thus treating the ] as data rather than
703 terminating the class. This meant it could skip too much.]
705 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
706 /g option in pcretest when the pattern contains \K, which makes it possible
707 to have an empty string match not at the start, even when the pattern is
708 anchored. Updated pcretest and pcredemo to use this option.
710 21. If the maximum number of capturing subpatterns in a recursion was greater
711 than the maximum at the outer level, the higher number was returned, but
712 with unset values at the outer level. The correct (outer level) value is
713 now given.
715 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
716 PCRE did not set those parentheses (unlike Perl). I have now found a way to
717 make it do so. The string so far is captured, making this feature
718 compatible with Perl.
720 23. The tests have been re-organized, adding tests 11 and 12, to make it
721 possible to check the Perl 5.10 features against Perl 5.10.
723 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
724 pattern matches a fixed length string. PCRE did not allow this; now it
725 does. Neither allows recursion.
727 25. I finally figured out how to implement a request to provide the minimum
728 length of subject string that was needed in order to match a given pattern.
729 (It was back references and recursion that I had previously got hung up
730 on.) This code has now been added to pcre_study(); it finds a lower bound
731 to the length of subject needed. It is not necessarily the greatest lower
732 bound, but using it to avoid searching strings that are too short does give
733 some useful speed-ups. The value is available to calling programs via
734 pcre_fullinfo().
736 26. While implementing 25, I discovered to my embarrassment that pcretest had
737 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
738 study optimizations had never been tested with that matching function.
739 Oops. What is worse, even when it was passed study data, there was a bug in
740 pcre_dfa_exec() that meant it never actually used it. Double oops. There
741 were also very few tests of studied patterns with pcre_dfa_exec().
743 27. If (?| is used to create subpatterns with duplicate numbers, they are now
744 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
745 on the other side of the coin, they are no longer allowed to have different
746 names, because these cannot be distinguished in PCRE, and this has caused
747 confusion. (This is a difference from Perl.)
749 28. When duplicate subpattern names are present (necessarily with different
750 numbers, as required by 27 above), and a test is made by name in a
751 conditional pattern, either for a subpattern having been matched, or for
752 recursion in such a pattern, all the associated numbered subpatterns are
753 tested, and the overall condition is true if the condition is true for any
754 one of them. This is the way Perl works, and is also more like the way
755 testing by number works.
758 Version 7.9 11-Apr-09
759 ---------------------
761 1. When building with support for bzlib/zlib (pcregrep) and/or readline
762 (pcretest), all targets were linked against these libraries. This included
763 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
764 libraries. This caused unwanted dependencies to be created. This problem
765 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
766 pcretest is linked with readline.
768 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
769 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
770 moved outside it again, because FALSE and TRUE are already defined in AIX,
771 but BOOL is not.
773 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
774 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
776 4. The pcregrep documentation said spaces were inserted as well as colons (or
777 hyphens) following file names and line numbers when outputting matching
778 lines. This is not true; no spaces are inserted. I have also clarified the
779 wording for the --colour (or --color) option.
781 5. In pcregrep, when --colour was used with -o, the list of matching strings
782 was not coloured; this is different to GNU grep, so I have changed it to be
783 the same.
785 6. When --colo(u)r was used in pcregrep, only the first matching substring in
786 each matching line was coloured. Now it goes on to look for further matches
787 of any of the test patterns, which is the same behaviour as GNU grep.
789 7. A pattern that could match an empty string could cause pcregrep to loop; it
790 doesn't make sense to accept an empty string match in pcregrep, so I have
791 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
792 seems to be how GNU grep behaves.
794 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
795 start or after a newline", because the conditional assertion was not being
796 correctly handled. The rule now is that both the assertion and what follows
797 in the first alternative must satisfy the test.
799 9. If auto-callout was enabled in a pattern with a conditional group whose
800 condition was an assertion, PCRE could crash during matching, both with
801 pcre_exec() and pcre_dfa_exec().
803 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
804 used for matching.
806 11. Unicode property support in character classes was not working for
807 characters (bytes) greater than 127 when not in UTF-8 mode.
809 12. Added the -M command line option to pcretest.
811 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
813 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
815 16. Added comments and documentation about mis-use of no_arg in the C++
816 wrapper.
818 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
819 from Martin Jerabek that uses macro names for all relevant character and
820 string constants.
822 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
823 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
824 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
825 these, but not everybody uses configure.
827 19. A conditional group that had only one branch was not being correctly
828 recognized as an item that could match an empty string. This meant that an
829 enclosing group might also not be so recognized, causing infinite looping
830 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
831 with the subject "ab", where knowledge that the repeated group can match
832 nothing is needed in order to break the loop.
834 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
835 exec(), but without supplying a callout function, matching went wrong.
837 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
838 leak if the size of the offset vector was greater than 30. When the vector
839 is smaller, the saved offsets during recursion go onto a local stack
840 vector, but for larger vectors malloc() is used. It was failing to free
841 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
842 error, in fact).
844 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
845 heapframe that is used only when UTF-8 support is enabled. This caused no
846 problem, but was untidy.
848 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
849 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
850 included within another project.
852 24. Steven Van Ingelgem's patches to add more options to the CMake support,
853 slightly modified by me:
855 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
856 not building pcregrep.
858 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
859 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
861 25. Forward references, both numeric and by name, in patterns that made use of
862 duplicate group numbers, could behave incorrectly or give incorrect errors,
863 because when scanning forward to find the reference group, PCRE was not
864 taking into account the duplicate group numbers. A pattern such as
865 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
867 26. Changed a few more instances of "const unsigned char *" to USPTR, making
868 the feature of a custom pointer more persuasive (as requested by a user).
870 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
871 pcretest.c, inside #ifndefs, because it seems they are sometimes already
872 pre-defined.
874 28. Added support for (*UTF8) at the start of a pattern.
876 29. Arrange for flags added by the "release type" setting in CMake to be shown
877 in the configuration summary.
880 Version 7.8 05-Sep-08
881 ---------------------
883 1. Replaced UCP searching code with optimized version as implemented for Ad
884 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
885 stage table and inline lookup instead of a function, giving speed ups of 2
886 to 5 times on some simple patterns that I tested. Permission was given to
887 distribute the MultiStage2.py script that generates the tables (it's not in
888 the tarball, but is in the Subversion repository).
890 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
891 scripts.
893 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
894 a group with a zero qualifier. The result of the study could be incorrect,
895 or the function might crash, depending on the pattern.
897 4. Caseless matching was not working for non-ASCII characters in back
898 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
899 It now works when Unicode Property Support is available.
901 5. In pcretest, an escape such as \x{de} in the data was always generating
902 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
903 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
904 truncation.
906 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
908 7. Added two (int) casts to pcregrep when printing the difference of two
909 pointers, in case they are 64-bit values.
911 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
912 test 2 if it fails.
914 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
915 and a #define of that name to empty if it is not externally set. This is to
916 allow users of MSVC to set it if necessary.
918 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
919 the convenience functions in the pcre_get.c source file.
921 11. An option change at the start of a pattern that had top-level alternatives
922 could cause overwriting and/or a crash. This command provoked a crash in
923 some environments:
925 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
927 This potential security problem was recorded as CVE-2008-2371.
929 12. For a pattern where the match had to start at the beginning or immediately
930 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
931 pcre_dfa_exec() could read past the end of the passed subject if there was
932 no match. To help with detecting such bugs (e.g. with valgrind), I modified
933 pcretest so that it places the subject at the end of its malloc-ed buffer.
935 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
936 exec() might read past the end of the data buffer in UTF-8 mode.
938 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
939 the data contained the byte 0x85 as part of a UTF-8 character within its
940 first line. This applied both to normal and DFA matching.
942 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
943 /^[^d]*?$/8 failed to match "abc".
945 16. Added a missing copyright notice to pcrecpp_internal.h.
947 17. Make it more clear in the documentation that values returned from
948 pcre_exec() in ovector are byte offsets, not character counts.
950 18. Tidied a few places to stop certain compilers from issuing warnings.
952 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
953 supplied by Stefan Weber. I made a further small update for 7.8 because
954 there is a change of source arrangements: the pcre_searchfuncs.c module is
955 replaced by pcre_ucd.c.
958 Version 7.7 07-May-08
959 ---------------------
961 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
962 a string to a long long, pretend we don't even have a long long." This is
963 done by checking for the strtoq, strtoll, and _strtoi64 functions.
965 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
966 pre-7.6 versions, which defined a global no_arg variable instead of putting
967 it in the RE class. (See also #8 below.)
969 3. Remove a line of dead code, identified by coverity and reported by Nuno
970 Lopes.
972 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
974 (1) The include/exclude patterns were being applied to the whole pathnames
975 of files, instead of just to the final components.
977 (2) If there was more than one level of directory, the subdirectories were
978 skipped unless they satisfied the include/exclude conditions. This is
979 inconsistent with GNU grep (and could even be seen as contrary to the
980 pcregrep specification - which I improved to make it absolutely clear).
981 The action now is always to scan all levels of directory, and just
982 apply the include/exclude patterns to regular files.
984 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
985 --exclude_dir in the tests to avoid scanning .svn directories.
987 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
988 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
989 doesn't support NULs in patterns.
991 7. Added some missing "const"s to declarations of static tables in
992 pcre_compile.c and pcre_dfa_exec.c.
994 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
995 caused by fix #2 above. (Subsequently also a second patch to fix the
996 first patch. And a third patch - this was a messy problem.)
998 9. Applied Craig's patch to remove the use of push_back().
1000 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1001 matching function regexec().
1003 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1004 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1005 references. PCRE supports relative numbers with this syntax (I don't think
1006 Oniguruma does).
1008 12. Previously, a group with a zero repeat such as (...){0} was completely
1009 omitted from the compiled regex. However, this means that if the group
1010 was called as a subroutine from elsewhere in the pattern, things went wrong
1011 (an internal error was given). Such groups are now left in the compiled
1012 pattern, with a new opcode that causes them to be skipped at execution
1013 time.
1015 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1016 to the way PCRE behaves:
1018 (a) A lone ] character is dis-allowed (Perl treats it as data).
1020 (b) A back reference to an unmatched subpattern matches an empty string
1021 (Perl fails the current match path).
1023 (c) A data ] in a character class must be notated as \] because if the
1024 first data character in a class is ], it defines an empty class. (In
1025 Perl it is not possible to have an empty class.) The empty class []
1026 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1027 The negative empty class [^] matches any one character, independently
1028 of the DOTALL setting.
1030 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1031 non-existent subpattern following a character class starting with ']' and
1032 containing () gave an internal compiling error instead of "reference to
1033 non-existent subpattern". Fortunately, when the pattern did exist, the
1034 compiled code was correct. (When scanning forwards to check for the
1035 existencd of the subpattern, it was treating the data ']' as terminating
1036 the class, so got the count wrong. When actually compiling, the reference
1037 was subsequently set up correctly.)
1039 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1040 it was being rejected as not supported by pcre_dfa_exec(), even though
1041 other assertions are supported. I have made pcre_dfa_exec() support
1042 (*FAIL).
1044 16. The implementation of 13c above involved the invention of a new opcode,
1045 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1046 cannot be changed at match time, I realized I could make a small
1047 improvement to matching performance by compiling OP_ALLANY instead of
1048 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1049 on the OP_ANY path.
1051 17. Compiling pcretest on Windows with readline support failed without the
1052 following two fixes: (1) Make the unistd.h include conditional on
1053 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1055 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1056 ncurses library to be included for pcretest when ReadLine support is
1057 requested, but also to allow for it to be overridden. This patch came from
1058 Daniel Bergström.
1060 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1061 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1062 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1063 spotting this.
1066 Version 7.6 28-Jan-08
1067 ---------------------
1069 1. A character class containing a very large number of characters with
1070 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1071 overflow.
1073 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1074 HAVE_LONG_LONG is not defined.
1076 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1077 bring them up to date and include new features. This patch includes:
1079 - Fixed PH's badly added libz and libbz2 support.
1080 - Fixed a problem with static linking.
1081 - Added pcredemo. [But later removed - see 7 below.]
1082 - Fixed dftables problem and added an option.
1083 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1085 - Added readline support for pcretest.
1086 - Added an listing of the option settings after cmake has run.
1088 4. A user submitted a patch to Makefile that makes it easy to create
1089 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1090 Makefile.am that cause it to include this special target, without
1091 affecting anything else. Note that the same mingw target plus all
1092 the other distribution libraries and programs are now supported
1093 when configuring with CMake (see 6 below) instead of with
1094 Configure/Make.
1096 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1097 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1098 exported in the Windows port". It has not yet been confirmed that the patch
1099 solves the problem, but it does no harm.
1101 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1102 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1103 with CMake, and also correct the comment about stack recursion.
1105 7. Remove the automatic building of pcredemo from the ./configure system and
1106 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1107 of a program that users should build themselves after PCRE is installed, so
1108 building it automatically is not really right. What is more, it gave
1109 trouble in some build environments.
1111 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1114 Version 7.5 10-Jan-08
1115 ---------------------
1117 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1118 values in parens when parsing an RE using the C++ wrapper."
1120 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1121 Characters greater than 255 were excluded from the class instead of being
1122 included.
1124 3. The same bug as (2) above applied to negated POSIX classes such as
1125 [:^space:].
1127 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1128 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1129 I have changed it.
1131 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1132 first named subpattern) and a construct such as (?&a) would reference the
1133 first named subpattern whose name started with "a" (in other words, the
1134 length check was missing). Both these problems are fixed. "Subpattern name
1135 expected" is now given for (?&) (a zero-length name), and this patch also
1136 makes it give the same error for \k'' (previously it complained that that
1137 was a reference to a non-existent subpattern).
1139 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1140 this is right because (?- can be followed by option settings as well as by
1141 digits. I have, however, made the messages clearer.
1143 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1144 than the number used in the conditional) now cause a compile-time error.
1145 This is actually not compatible with Perl, which accepts such patterns, but
1146 treats the conditional as always being FALSE (as PCRE used to), but it
1147 seems to me that giving a diagnostic is better.
1149 8. Change "alphameric" to the more common word "alphanumeric" in comments
1150 and messages.
1152 9. Fix two occurrences of "backslash" in comments that should have been
1153 "backspace".
1155 10. Remove two redundant lines of code that can never be obeyed (their function
1156 was moved elsewhere).
1158 11. The program that makes PCRE's Unicode character property table had a bug
1159 which caused it to generate incorrect table entries for sequences of
1160 characters that have the same character type, but are in different scripts.
1161 It amalgamated them into a single range, with the script of the first of
1162 them. In other words, some characters were in the wrong script. There were
1163 thirteen such cases, affecting characters in the following ranges:
1165 U+002b0 - U+002c1
1166 U+0060c - U+0060d
1167 U+0061e - U+00612
1168 U+0064b - U+0065e
1169 U+0074d - U+0076d
1170 U+01800 - U+01805
1171 U+01d00 - U+01d77
1172 U+01d9b - U+01dbf
1173 U+0200b - U+0200f
1174 U+030fc - U+030fe
1175 U+03260 - U+0327f
1176 U+0fb46 - U+0fbb1
1177 U+10450 - U+1049d
1179 12. The -o option (show only the matching part of a line) for pcregrep was not
1180 compatible with GNU grep in that, if there was more than one match in a
1181 line, it showed only the first of them. It now behaves in the same way as
1182 GNU grep.
1184 13. If the -o and -v options were combined for pcregrep, it printed a blank
1185 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1186 does the same. The return code can be used to tell if there were any
1187 non-matching lines.
1189 14. Added --file-offsets and --line-offsets to pcregrep.
1191 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1192 infinitely looping recursion. The bug was that positive lookaheads were not
1193 being skipped when checking for a possible empty match (negative lookaheads
1194 and both kinds of lookbehind were skipped).
1196 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1197 inclusion of <windows.h> to before rather than after the definition of
1198 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1200 17. Specifying a possessive quantifier with a specific limit for a Unicode
1201 character property caused pcre_compile() to compile bad code, which led at
1202 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1203 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1204 caused the error; without that there was no problem.
1206 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1208 19. Added --enable-pcretest-libreadline.
1210 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1211 RE::GlobalReplace(). As a result, the number of replacements returned was
1212 double what it should be. I removed one of the increments, but Craig sent a
1213 later patch that removed the other one (the right fix) and added unit tests
1214 that check the return values (which was not done before).
1216 21. Several CMake things:
1218 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1219 the names libpcre and libpcreposix, not just pcre and pcreposix.
1221 (2) The above change means that pcretest and pcregrep are now correctly
1222 linked with the newly-built libraries, not previously installed ones.
1226 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1227 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1228 UTF-8 newline character). The key issue is that the pattern starts .*;
1229 this means that the match must be either at the beginning, or after a
1230 newline. The bug was in the code for advancing after a failed match and
1231 checking that the new position followed a newline. It was not taking
1232 account of UTF-8 characters correctly.
1234 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1235 character classes. PCRE was not treating the sequence [:...:] as a
1236 character class unless the ... were all letters. Perl, however, seems to
1237 allow any characters between [: and :], though of course it rejects as
1238 unknown any "names" that contain non-letters, because all the known class
1239 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1240 for example, whereas PCRE did not - it did not recognize a POSIX character
1241 class. This seemed a bit dangerous, so the code has been changed to be
1242 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1243 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1244 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1245 Perl does, and where it didn't before.
1247 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1248 Windows environments %n is disabled by default.
1251 Version 7.4 21-Sep-07
1252 ---------------------
1254 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1255 means that a class such as [\s] counted as "explicit reference to CR or
1256 LF". That isn't really right - the whole point of the change was to try to
1257 help when there was an actual mention of one of the two characters. So now
1258 the change happens only if \r or \n (or a literal CR or LF) character is
1259 encountered.
1261 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1262 of both had grown to the point where there were only 3 bits left.
1263 Fortunately, there was spare space in the data structure, and so I have
1264 moved the internal flags into a new 16-bit field to free up more option
1265 bits.
1267 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1268 but did not set the internal JCHANGED flag - either of these is enough to
1269 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1270 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1271 start sets both bits.
1273 4. Added options (at build time, compile time, exec time) to change \R from
1274 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1276 5. doc/pcresyntax.html was missing from the distribution.
1278 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1279 compatibility, even though it is no longer used.
1281 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1282 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1283 windows.h file is present (where different names are used). [This was
1284 reversed later after testing - see 16 below.]
1286 8. Changed all #include <config.h> to #include "config.h". There were also
1287 some further <pcre.h> cases that I changed to "pcre.h".
1289 9. When pcregrep was used with the --colour option, it missed the line ending
1290 sequence off the lines that it output.
1292 10. It was pointed out to me that arrays of string pointers cause lots of
1293 relocations when a shared library is dynamically loaded. A technique of
1294 using a single long string with a table of offsets can drastically reduce
1295 these. I have refactored PCRE in four places to do this. The result is
1296 dramatic:
1298 Originally: 290
1299 After changing UCP table: 187
1300 After changing error message table: 43
1301 After changing table of "verbs" 36
1302 After changing table of Posix names 22
1304 Thanks to the folks working on Gregex for glib for this insight.
1306 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1307 unicode-properties was also set.
1309 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1311 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1312 checked only for CRLF.
1314 14. Added casts to pcretest.c to avoid compiler warnings.
1316 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1318 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1319 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1320 entirely. This removes changes made in 7 above.
1322 17. The CMake files have been updated, and there is now more information about
1323 building with CMake in the NON-UNIX-USE document.
1326 Version 7.3 28-Aug-07
1327 ---------------------
1329 1. In the rejigging of the build system that eventually resulted in 7.1, the
1330 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1331 brackets there is not right, since it causes compilers to look for an
1332 installed pcre.h, not the version that is in the source that is being
1333 compiled (which of course may be different). I have changed it back to:
1335 #include "pcre.h"
1337 I have a vague recollection that the change was concerned with compiling in
1338 different directories, but in the new build system, that is taken care of
1339 by the VPATH setting the Makefile.
1341 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1342 when the subject happened to end in the byte 0x85 (e.g. if the last
1343 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1344 characters but of course it shouldn't be taken as a newline when it is part
1345 of another character. The bug was that, for an unlimited repeat of . in
1346 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1347 characters when looking for a newline.
1349 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1351 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1352 in debug output.
1354 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1355 long printing in the pcrecpp unittest when running under MinGW.
1357 6. ESC_K was left out of the EBCDIC table.
1359 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1360 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1361 limit also applies to "virtual nesting" when a pattern is recursive, and in
1362 this case 1000 isn't so big. I have been able to remove this limit at the
1363 expense of backing off one optimization in certain circumstances. Normally,
1364 when pcre_exec() would call its internal match() function recursively and
1365 immediately return the result unconditionally, it uses a "tail recursion"
1366 feature to save stack. However, when a subpattern that can match an empty
1367 string has an unlimited repetition quantifier, it no longer makes this
1368 optimization. That gives it a stack frame in which to save the data for
1369 checking that an empty string has been matched. Previously this was taken
1370 from the 1000-entry workspace that had been reserved. So now there is no
1371 explicit limit, but more stack is used.
1373 8. Applied Daniel's patches to solve problems with the import/export magic
1374 syntax that is required for Windows, and which was going wrong for the
1375 pcreposix and pcrecpp parts of the library. These were overlooked when this
1376 problem was solved for the main library.
1378 9. There were some crude static tests to avoid integer overflow when computing
1379 the size of patterns that contain repeated groups with explicit upper
1380 limits. As the maximum quantifier is 65535, the maximum group length was
1381 set at 30,000 so that the product of these two numbers did not overflow a
1382 32-bit integer. However, it turns out that people want to use groups that
1383 are longer than 30,000 bytes (though not repeat them that many times).
1384 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1385 made it possible to implement the integer overflow checks in a much more
1386 dynamic way, which I have now done. The artificial limitation on group
1387 length has been removed - we now have only the limit on the total length of
1388 the compiled pattern, which depends on the LINK_SIZE setting.
1390 10. Fixed a bug in the documentation for get/copy named substring when
1391 duplicate names are permitted. If none of the named substrings are set, the
1392 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1393 empty string.
1395 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1396 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1397 because the ] is interpreted as the first data character and the
1398 terminating ] is not found. PCRE has been made compatible with Perl in this
1399 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1400 cause memory overwriting.
1402 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1403 string has been matched (to stop an infinite loop). It was not recognizing
1404 a conditional subpattern that could match an empty string if that
1405 subpattern was within another subpattern. For example, it looped when
1406 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1407 condition was not nested. This bug has been fixed.
1409 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1410 past the start of the subject in the presence of bytes with the top bit
1411 set, for example "\x8aBCD".
1413 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1414 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1416 14. Optimized (?!) to (*FAIL).
1418 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1419 This restricts code points to be within the range 0 to 0x10FFFF, excluding
1420 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1421 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1422 does: it's just the validity check that is more restrictive.
1424 16. Inserted checks for integer overflows during escape sequence (backslash)
1425 processing, and also fixed erroneous offset values for syntax errors during
1426 backslash processing.
1428 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1429 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1431 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1432 caused an overrun.
1434 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1435 something other than just ASCII characters) inside a group that had an
1436 unlimited repeat caused a loop at compile time (while checking to see
1437 whether the group could match an empty string).
1439 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1440 [\P{Any}] did so. (Error in the code for printing property names.)
1442 21. An orphan \E inside a character class could cause a crash.
1444 22. A repeated capturing bracket such as (A)? could cause a wild memory
1445 reference during compilation.
1447 23. There are several functions in pcre_compile() that scan along a compiled
1448 expression for various reasons (e.g. to see if it's fixed length for look
1449 behind). There were bugs in these functions when a repeated \p or \P was
1450 present in the pattern. These operators have additional parameters compared
1451 with \d, etc, and these were not being taken into account when moving along
1452 the compiled data. Specifically:
1454 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1455 length.
1457 (b) An item such as \pL+ within a repeated group could cause crashes or
1458 loops.
1460 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1461 "reference to non-existent subpattern" error.
1463 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1465 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1466 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1468 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1470 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1471 character were causing crashes (broken optimization).
1473 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1474 \p or \P) caused a compile-time loop.
1476 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1477 break. For example, the unstudied pattern [\r\n]A does not match the string
1478 "\r\nA" because change 7.0/46 below moves the current point on by two
1479 characters after failing to match at the start. However, the pattern \nA
1480 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1481 the same is true. There doesn't seem any very clean way out of this, but
1482 what I have chosen to do makes the common cases work: PCRE now takes note
1483 of whether there can be an explicit match for \r or \n anywhere in the
1484 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1485 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1486 pattern has explicit CR or LF references.
1488 29. Added (*CR) etc for changing newline setting at start of pattern.
1491 Version 7.2 19-Jun-07
1492 ---------------------
1494 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1495 which is apparently normally available under Windows.
1497 2. Re-jig the pcregrep tests with different newline settings in an attempt
1498 to make them independent of the local environment's newline setting.
1500 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1502 4. Some of the "internals" tests were previously cut out when the link size
1503 was not 2, because the output contained actual offsets. The recent new
1504 "Z" feature of pcretest means that these can be cut out, making the tests
1505 usable with all link sizes.
1507 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1508 stack recursion. This gives a massive performance boost under BSD, but just
1509 a small improvement under Linux. However, it saves one field in the frame
1510 in all cases.
1512 6. Added more features from the forthcoming Perl 5.10:
1514 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1515 recursion call. It refers to the nth most recently opened parentheses.
1517 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1518 to be opened parentheses.
1520 (c) Conditions that refer to capturing parentheses can be specified
1521 relatively, for example, (?(-2)... or (?(+3)...
1523 (d) \K resets the start of the current match so that everything before
1524 is not part of it.
1526 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1528 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1529 reference syntax.
1531 (g) (?| introduces a group in which the numbering of parentheses in each
1532 alternative starts with the same number.
1534 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1536 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1539 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1540 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1541 for detecting groups that can match an empty string.
1543 9. A pattern with a very large number of alternatives (more than several
1544 hundred) was running out of internal workspace during the pre-compile
1545 phase, where pcre_compile() figures out how much memory will be needed. A
1546 bit of new cunning has reduced the workspace needed for groups with
1547 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1548 workspace instead of running out of the 4096 that are available.
1550 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1552 11. Applied patch from Google to remove an optimization that didn't quite work.
1553 The report of the bug said:
1555 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1556 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1557 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1559 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1560 it matched the wrong number of bytes.
1563 Version 7.1 24-Apr-07
1564 ---------------------
1566 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1567 that is more "standard", making use of automake and other Autotools. There
1568 is some re-arrangement of the files and adjustment of comments consequent
1569 on this.
1571 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1572 for recursive directory scanning broke on some systems because the files
1573 are not scanned in any specific order and on different systems the order
1574 was different. A call to "sort" has been inserted into RunGrepTest for the
1575 approprate test as a short-term fix. In the longer term there may be an
1576 alternative.
1578 3. I had an email from Eric Raymond about problems translating some of PCRE's
1579 man pages to HTML (despite the fact that I distribute HTML pages, some
1580 people do their own conversions for various reasons). The problems
1581 concerned the use of low-level troff macros .br and .in. I have therefore
1582 removed all such uses from the man pages (some were redundant, some could
1583 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1584 HTML has been updated to handle .nf/.fi and to complain if it encounters
1585 .br or .in.
1587 4. Updated comments in configure.ac that get placed in config.h.in and also
1588 arranged for config.h to be included in the distribution, with the name
1589 config.h.generic, for the benefit of those who have to compile without
1590 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1592 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1593 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1594 makevp.bat for the current PCRE, using the additional files
1595 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1597 6. A Windows user reported a minor discrepancy with test 2, which turned out
1598 to be caused by a trailing space on an input line that had got lost in his
1599 copy. The trailing space was an accident, so I've just removed it.
1601 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1602 that is needed.
1604 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1605 as "const" (a) because they are and (b) because it helps the PHP
1606 maintainers who have recently made a script to detect big data structures
1607 in the php code that should be moved to the .rodata section. I remembered
1608 to update Builducptable as well, so it won't revert if ucptable.h is ever
1609 re-created.
1611 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1612 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1613 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1614 support is not required. This saves 1.5-2K of code, which is important in
1615 some applications.
1617 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1618 so as not to refer to the tables, even though these functions will never be
1619 called when UTF-8 support is disabled. Otherwise there are problems with a
1620 shared library.
1622 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1624 (a) It was defining its arguments as char * instead of void *.
1626 (b) It was assuming that all moves were upwards in memory; this was true
1627 a long time ago when I wrote it, but is no longer the case.
1629 The emulated memove() is provided for those environments that have neither
1630 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1631 is clearly not the case, as these two bugs were recently reported.
1633 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1634 and Detrail to create the HTML documentation, the .txt form of the man
1635 pages, and it removes trailing spaces from listed files. It also creates
1636 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1637 case, it wraps all the #defines with #ifndefs. This script should be run
1638 before "make dist".
1640 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1641 with Unicode property support.
1643 (a) For a maximizing quantifier, if the two different cases of the
1644 character were of different lengths in their UTF-8 codings (there are
1645 some cases like this - I found 11), and the matching function had to
1646 back up over a mixture of the two cases, it incorrectly assumed they
1647 were both the same length.
1649 (b) When PCRE was configured to use the heap rather than the stack for
1650 recursion during matching, it was not correctly preserving the data for
1651 the other case of a UTF-8 character when checking ahead for a match
1652 while processing a minimizing repeat. If the check also involved
1653 matching a wide character, but failed, corruption could cause an
1654 erroneous result when trying to check for a repeat of the original
1655 character.
1657 13. Some tidying changes to the testing mechanism:
1659 (a) The RunTest script now detects the internal link size and whether there
1660 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1661 values substituted by "configure". (The RunGrepTest script already did
1662 this for UTF-8.) The configure.ac script no longer substitutes the
1663 relevant variables.
1665 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1666 with length and offset values. This means that the output is different
1667 for different internal link sizes. Test 2 is skipped for link sizes
1668 other than 2 because of this, bypassing the problem. Unfortunately,
1669 there was also a test in test 3 (the locale tests) that used /B and
1670 failed for link sizes other than 2. Rather than cut the whole test out,
1671 I have added a new /Z option to pcretest that replaces the length and
1672 offset values with spaces. This is now used to make test 3 independent
1673 of link size. (Test 2 will be tidied up later.)
1675 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1676 segmentation fault instead of returning the appropriate error message.
1678 15. In multiline mode when the newline sequence was set to "any", the pattern
1679 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1680 This doesn't seem right; it now treats the CRLF combination as the line
1681 ending, and so does not match in that case. It's only a pattern such as ^$
1682 that would hit this one: something like ^ABC$ would have failed after \r
1683 and then tried again after \r\n.
1685 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1686 in an attempt to make files that differ only in their line terminators
1687 compare equal. This works on Linux.
1689 17. Under certain error circumstances pcregrep might try to free random memory
1690 as it exited. This is now fixed, thanks to valgrind.
1692 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1693 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1694 was because its rules for how to advance for /g after matching an empty
1695 string at the end of a line did not allow for this case. They now check for
1696 it specially.
1698 20. pcretest is supposed to handle patterns and data of any length, by
1699 extending its buffers when necessary. It was getting this wrong when the
1700 buffer for a data line had to be extended.
1702 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1703 CRLF as a newline sequence.
1705 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1706 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1707 I have nevertheless tidied it up.
1709 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1711 24. Added a man page for pcre-config.
1714 Version 7.0 19-Dec-06
1715 ---------------------
1717 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1718 moving to gcc 4.1.1.
1720 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1721 sys/time.h, which is documented as needed for this function. It doesn't
1722 seem to matter on Linux, but it showed up on some releases of OS X.
1724 3. It seems that there are systems where bytes whose values are greater than
1725 127 match isprint() in the "C" locale. The "C" locale should be the
1726 default when a C program starts up. In most systems, only ASCII printing
1727 characters match isprint(). This difference caused the output from pcretest
1728 to vary, making some of the tests fail. I have changed pcretest so that:
1730 (a) When it is outputting text in the compiled version of a pattern, bytes
1731 other than 32-126 are always shown as hex escapes.
1733 (b) When it is outputting text that is a matched part of a subject string,
1734 it does the same, unless a different locale has been set for the match
1735 (using the /L modifier). In this case, it uses isprint() to decide.
1737 4. Fixed a major bug that caused incorrect computation of the amount of memory
1738 required for a compiled pattern when options that changed within the
1739 pattern affected the logic of the preliminary scan that determines the
1740 length. The relevant options are -x, and -i in UTF-8 mode. The result was
1741 that the computed length was too small. The symptoms of this bug were
1742 either the PCRE error "internal error: code overflow" from pcre_compile(),
1743 or a glibc crash with a message such as "pcretest: free(): invalid next
1744 size (fast)". Examples of patterns that provoked this bug (shown in
1745 pcretest format) are:
1747 /(?-x: )/x
1748 /(?x)(?-x: \s*#\s*)/
1749 /((?i)[\x{c0}])/8
1750 /(?i:[\x{c0}])/8
1752 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1753 is now done differently.
1755 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1756 wrapper classes; (b) implement a new function in the C++ scanner that is
1757 more efficient than the old way of doing things because it avoids levels of
1758 recursion in the regex matching; (c) add a paragraph to the documentation
1759 for the FullMatch() function.
1761 6. The escape sequence \n was being treated as whatever was defined as
1762 "newline". Not only was this contrary to the documentation, which states
1763 that \n is character 10 (hex 0A), but it also went horribly wrong when
1764 "newline" was defined as CRLF. This has been fixed.
1766 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1767 was being set to -1 for the "end of line" case (supposedly a value that no
1768 character can have). Though this value is never used (the check for end of
1769 line is "zero bytes in current character"), it caused compiler complaints.
1770 I've changed it to 0xffffffff.
1772 8. In pcre_version.c, the version string was being built by a sequence of
1773 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1774 string (as it is for production releases) called a macro with an empty
1775 argument. The C standard says the result of this is undefined. The gcc
1776 compiler treats it as an empty string (which was what was wanted) but it is
1777 reported that Visual C gives an error. The source has been hacked around to
1778 avoid this problem.
1780 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1781 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1782 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1783 of them did).
1785 10. Originally, pcretest opened its input and output without "b"; then I was
1786 told that "b" was needed in some environments, so it was added for release
1787 5.0 to both the input and output. (It makes no difference on Unix-like
1788 systems.) Later I was told that it is wrong for the input on Windows. I've
1789 now abstracted the modes into two macros, to make it easier to fiddle with
1790 them, and removed "b" from the input mode under Windows.
1792 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1794 12. Added -help and --help to pcretest as an official way of being reminded
1795 of the options.
1797 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1798 and pcrecpp.cc because they annoy compilers at high warning levels.
1800 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1802 15. Fixed an occurrence of == in configure.ac that should have been = (shell
1803 scripts are not C programs :-) and which was not noticed because it works
1804 on Linux.
1806 16. pcretest is supposed to handle any length of pattern and data line (as one
1807 line or as a continued sequence of lines) by extending its input buffer if
1808 necessary. This feature was broken for very long pattern lines, leading to
1809 a string of junk being passed to pcre_compile() if the pattern was longer
1810 than about 50K.
1812 17. I have done a major re-factoring of the way pcre_compile() computes the
1813 amount of memory needed for a compiled pattern. Previously, there was code
1814 that made a preliminary scan of the pattern in order to do this. That was
1815 OK when PCRE was new, but as the facilities have expanded, it has become
1816 harder and harder to keep it in step with the real compile phase, and there
1817 have been a number of bugs (see for example, 4 above). I have now found a
1818 cunning way of running the real compile function in a "fake" mode that
1819 enables it to compute how much memory it would need, while actually only
1820 ever using a few hundred bytes of working memory and without too many
1821 tests of the mode. This should make future maintenance and development
1822 easier. A side effect of this work is that the limit of 200 on the nesting
1823 depth of parentheses has been removed (though this was never a serious
1824 limitation, I suspect). However, there is a downside: pcre_compile() now
1825 runs more slowly than before (30% or more, depending on the pattern). I
1826 hope this isn't a big issue. There is no effect on runtime performance.
1828 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1829 newline (only possible for the last line of a file) and it was a
1830 pattern that set a locale (followed by /Lsomething), pcretest crashed.
1832 19. Added additional timing features to pcretest. (1) The -tm option now times
1833 matching only, not compiling. (2) Both -t and -tm can be followed, as a
1834 separate command line item, by a number that specifies the number of
1835 repeats to use when timing. The default is 50000; this gives better
1836 precision, but takes uncomfortably long for very large patterns.
1838 20. Extended pcre_study() to be more clever in cases where a branch of a
1839 subpattern has no definite first character. For example, (a*|b*)[cd] would
1840 previously give no result from pcre_study(). Now it recognizes that the
1841 first character must be a, b, c, or d.
1843 21. There was an incorrect error "recursive call could loop indefinitely" if
1844 a subpattern (or the entire pattern) that was being tested for matching an
1845 empty string contained only one non-empty item after a nested subpattern.
1846 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1847 incorrectly, because the \d was being skipped in the check.
1849 22. The pcretest program now has a new pattern option /B and a command line
1850 option -b, which is equivalent to adding /B to every pattern. This causes
1851 it to show the compiled bytecode, without the additional information that
1852 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1853 is the same as /B/I).
1855 23. A new optimization is now able automatically to treat some sequences such
1856 as a*b as a*+b. More specifically, if something simple (such as a character
1857 or a simple class like \d) has an unlimited quantifier, and is followed by
1858 something that cannot possibly match the quantified thing, the quantifier
1859 is automatically "possessified".
1861 24. A recursive reference to a subpattern whose number was greater than 39
1862 went wrong under certain circumstances in UTF-8 mode. This bug could also
1863 have affected the operation of pcre_study().
1865 25. Realized that a little bit of performance could be had by replacing
1866 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1868 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1870 27. Possessive quantifiers such as a++ were previously implemented by turning
1871 them into atomic groups such as ($>a+). Now they have their own opcodes,
1872 which improves performance. This includes the automatically created ones
1873 from 23 above.
1875 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1876 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1877 the first matched character to be a colon. This applied both to named and
1878 numbered groups.
1880 29. The ucpinternal.h header file was missing its idempotency #ifdef.
1882 30. I was sent a "project" file called libpcre.a.dev which I understand makes
1883 building PCRE on Windows easier, so I have included it in the distribution.
1885 31. There is now a check in pcretest against a ridiculously large number being
1886 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1887 loop, the loop is abandoned.
1889 32. Forward references to subpatterns in conditions such as (?(2)...) where
1890 subpattern 2 is defined later cause pcre_compile() to search forwards in
1891 the pattern for the relevant set of parentheses. This search went wrong
1892 when there were unescaped parentheses in a character class, parentheses
1893 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1895 33. "Subroutine" calls and backreferences were previously restricted to
1896 referencing subpatterns earlier in the regex. This restriction has now
1897 been removed.
1899 34. Added a number of extra features that are going to be in Perl 5.10. On the
1900 whole, these are just syntactic alternatives for features that PCRE had
1901 previously implemented using the Python syntax or my own invention. The
1902 other formats are all retained for compatibility.
1904 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1905 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1906 also .NET compatible.
1908 (b) A recursion or subroutine call to a named group can now be defined as
1909 (?&name) as well as (?P>name).
1911 (c) A backreference to a named group can now be defined as \k<name> or
1912 \k'name' as well as (?P=name). The new forms, as well as being in Perl
1913 5.10, are also .NET compatible.
1915 (d) A conditional reference to a named group can now use the syntax
1916 (?(<name>) or (?('name') as well as (?(name).
1918 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1919 groups (named and numbered) that are never evaluated inline, but can be
1920 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1921 is always false. There may be only one alternative in such a group.
1923 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1924 as the simple (?(R). The condition is true only if the most recent
1925 recursion is that of the given number or name. It does not search out
1926 through the entire recursion stack.
1928 (g) The escape \gN or \g{N} has been added, where N is a positive or
1929 negative number, specifying an absolute or relative reference.
1931 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1932 some "unreachable code" warnings.
1934 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1935 things, this adds five new scripts.
1937 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1938 There were also incompatibilities regarding the handling of \Q..\E inside
1939 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1940 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1942 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1943 matches an empty string, and forcibly breaks the loop. There were bugs in
1944 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1945 against aaaa the result was just "a" rather than "aaaa", for example. Two
1946 separate and independent bugs (that affected different cases) have been
1947 fixed.
1949 39. Refactored the code to abolish the use of different opcodes for small
1950 capturing bracket numbers. This is a tidy that I avoided doing when I
1951 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1952 The new approach is not only tidier, it makes it possible to reduce the
1953 memory needed to fix the previous bug (38).
1955 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1956 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1957 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1958 mode.
1960 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1961 report.
1963 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1964 copy construction and assignment in the C++ wrapper.
1966 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1967 couple of bugs that could have given wrong results in the "--newline=crlf"
1968 case.
1970 44. Added a number of casts and did some reorganization of signed/unsigned int
1971 variables following suggestions from Dair Grant. Also renamed the variable
1972 "this" as "item" because it is a C++ keyword.
1974 45. Arranged for dftables to add
1976 #include "pcre_internal.h"
1978 to pcre_chartables.c because without it, gcc 4.x may remove the array
1979 definition from the final binary if PCRE is built into a static library and
1980 dead code stripping is activated.
1982 46. For an unanchored pattern, if a match attempt fails at the start of a
1983 newline sequence, and the newline setting is CRLF or ANY, and the next two
1984 characters are CRLF, advance by two characters instead of one.
1987 Version 6.7 04-Jul-06
1988 ---------------------
1990 1. In order to handle tests when input lines are enormously long, pcretest has
1991 been re-factored so that it automatically extends its buffers when
1992 necessary. The code is crude, but this _is_ just a test program. The
1993 default size has been increased from 32K to 50K.
1995 2. The code in pcre_study() was using the value of the re argument before
1996 testing it for NULL. (Of course, in any sensible call of the function, it
1997 won't be NULL.)
1999 3. The memmove() emulation function in pcre_internal.h, which is used on
2000 systems that lack both memmove() and bcopy() - that is, hardly ever -
2001 was missing a "static" storage class specifier.
2003 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2004 containing an extended class (one that cannot be represented by a bitmap
2005 because it contains high-valued characters or Unicode property items, e.g.
2006 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2007 pattern, but PCRE should not loop if you do not (it no longer does).
2008 [Detail: two cases were found: (a) a repeated subpattern containing an
2009 extended class; (b) a recursive reference to a subpattern that followed a
2010 previous extended class. It wasn't skipping over the extended class
2011 correctly when UTF-8 mode was not set.]
2013 5. A negated single-character class was not being recognized as fixed-length
2014 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2015 compile error "lookbehind assertion is not fixed length".
2017 6. The RunPerlTest auxiliary script was showing an unexpected difference
2018 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2019 write a Perl script that can interpret lines of an input file either as
2020 byte characters or as UTF-8, which is what "perltest" was being required to
2021 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2022 can't do is switch easily at run time between having the "use utf8;" pragma
2023 or not. In the end, I fudged it by using the RunPerlTest script to insert
2024 "use utf8;" explicitly for the UTF-8 tests.
2026 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2027 the end of the subject string, contrary to the documentation and to what
2028 Perl does. This was true of both matching functions. Now it matches only at
2029 the start of the subject and immediately after *internal* newlines.
2031 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2032 a pointer to an int instead of a pointer to an unsigned long int. This
2033 caused problems on 64-bit systems.
2035 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2036 instance of the 'standard' template library not being so standard".
2038 10. There was no check on the number of named subpatterns nor the maximum
2039 length of a subpattern name. The product of these values is used to compute
2040 the size of the memory block for a compiled pattern. By supplying a very
2041 long subpattern name and a large number of named subpatterns, the size
2042 computation could be caused to overflow. This is now prevented by limiting
2043 the length of names to 32 characters, and the number of named subpatterns
2044 to 10,000.
2046 11. Subpatterns that are repeated with specific counts have to be replicated in
2047 the compiled pattern. The size of memory for this was computed from the
2048 length of the subpattern and the repeat count. The latter is limited to
2049 65535, but there was no limit on the former, meaning that integer overflow
2050 could in principle occur. The compiled length of a repeated subpattern is
2051 now limited to 30,000 bytes in order to prevent this.
2053 12. Added the optional facility to have named substrings with the same name.
2055 13. Added the ability to use a named substring as a condition, using the
2056 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2057 are numbers (not recommended). Forward references are permitted.
2059 14. Added forward references in named backreferences (if you see what I mean).
2061 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2062 pattern could run off the end of the subject. For example, the pattern
2063 "(?s)(.{1,5})"8 did this with the subject "ab".
2065 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2066 PCRE_CASELESS was set when matching characters that were quantified with ?
2067 or *.
2069 17. A character class other than a single negated character that had a minimum
2070 but no maximum quantifier - for example [ab]{6,} - was not handled
2071 correctly by pce_dfa_exec(). It would match only one character.
2073 18. A valid (though odd) pattern that looked like a POSIX character
2074 class but used an invalid character after [ (for example [[,abc,]]) caused
2075 pcre_compile() to give the error "Failed: internal error: code overflow" or
2076 in some cases to crash with a glibc free() error. This could even happen if
2077 the pattern terminated after [[ but there just happened to be a sequence of
2078 letters, a binary zero, and a closing ] in the memory that followed.
2080 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2081 over the years. Originally (before any Unicode support), just the bottom 8
2082 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2083 output from "man perlunicode" includes this:
2085 The regular expression compiler produces polymorphic opcodes. That
2086 is, the pattern adapts to the data and automatically switches to
2087 the Unicode character scheme when presented with Unicode data--or
2088 instead uses a traditional byte scheme when presented with byte
2089 data.
2091 Sadly, a wide octal escape does not cause a switch, and in a string with
2092 no other multibyte characters, these octal escapes are treated as before.
2093 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2094 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2095 Unicode string.
2097 I have not perpetrated such confusion in PCRE. Up till now, it took just
2098 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2099 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2100 translate to the appropriate multibyte character.
2102 29. Applied some refactoring to reduce the number of warnings from Microsoft
2103 and Borland compilers. This has included removing the fudge introduced
2104 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2105 a warning about an unused variable.
2107 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2108 characters since release 4.0, because Perl (from release 5.004) does not.
2109 [Or at least, is documented not to: some releases seem to be in conflict
2110 with the documentation.] However, when a pattern was studied with
2111 pcre_study() and all its branches started with \s, PCRE still included VT
2112 as a possible starting character. Of course, this did no harm; it just
2113 caused an unnecessary match attempt.
2115 22. Removed a now-redundant internal flag bit that recorded the fact that case
2116 dependency changed within the pattern. This was once needed for "required
2117 byte" processing, but is no longer used. This recovers a now-scarce options
2118 bit. Also moved the least significant internal flag bit to the most-
2119 significant bit of the word, which was not previously used (hangover from
2120 the days when it was an int rather than a uint) to free up another bit for
2121 the future.
2123 23. Added support for CRLF line endings as well as CR and LF. As well as the
2124 default being selectable at build time, it can now be changed at runtime
2125 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2126 specify that it is scanning data with non-default line endings.
2128 24. Changed the definition of CXXLINK to make it agree with the definition of
2129 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2131 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2132 recursions. This makes a big different to stack usage for some patterns.
2134 26. If a subpattern containing a named recursion or subroutine reference such
2135 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2136 the space required for the compiled pattern went wrong and gave too small a
2137 value. Depending on the environment, this could lead to "Failed: internal
2138 error: code overflow at offset 49" or "glibc detected double free or
2139 corruption" errors.
2141 27. Applied patches from Google (a) to support the new newline modes and (b) to
2142 advance over multibyte UTF-8 characters in GlobalReplace.
2144 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2145 difference for some implementation of PCRE in some Windows version.
2147 29. Added some extra testing facilities to pcretest:
2149 \q<number> in a data line sets the "match limit" value
2150 \Q<number> in a data line sets the "match recursion limt" value
2151 -S <number> sets the stack size, where <number> is in megabytes
2153 The -S option isn't available for Windows.
2156 Version 6.6 06-Feb-06
2157 ---------------------
2159 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2160 in pcreposix.h. I have copied the definition from pcre.h.
2162 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2163 because pcre.h is no longer a built file.
2165 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2166 not normally included in the compiled code.
2169 Version 6.5 01-Feb-06
2170 ---------------------
2172 1. When using the partial match feature with pcre_dfa_exec(), it was not
2173 anchoring the second and subsequent partial matches at the new starting
2174 point. This could lead to incorrect results. For example, with the pattern
2175 /1234/, partially matching against "123" and then "a4" gave a match.
2177 2. Changes to pcregrep:
2179 (a) All non-match returns from pcre_exec() were being treated as failures
2180 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2181 error message is output. Some extra information is given for the
2183 probably the only errors that are likely to be caused by users (by
2184 specifying a regex that has nested indefinite repeats, for instance).
2185 If there are more than 20 of these errors, pcregrep is abandoned.
2187 (b) A binary zero was treated as data while matching, but terminated the
2188 output line if it was written out. This has been fixed: binary zeroes
2189 are now no different to any other data bytes.
2191 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2192 used to set a locale for matching. The --locale=xxxx long option has
2193 been added (no short equivalent) to specify a locale explicitly on the
2194 pcregrep command, overriding the environment variables.
2196 (d) When -B was used with -n, some line numbers in the output were one less
2197 than they should have been.
2199 (e) Added the -o (--only-matching) option.
2201 (f) If -A or -C was used with -c (count only), some lines of context were
2202 accidentally printed for the final match.
2204 (g) Added the -H (--with-filename) option.
2206 (h) The combination of options -rh failed to suppress file names for files
2207 that were found from directory arguments.
2209 (i) Added the -D (--devices) and -d (--directories) options.
2211 (j) Added the -F (--fixed-strings) option.
2213 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2215 (l) Added the --colo(u)r option.
2217 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2218 is not present by default.
2220 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2221 items such as (?R) or (?1), when the recursion could match a number of
2222 alternatives. If it matched one of the alternatives, but subsequently,
2223 outside the recursion, there was a failure, the code tried to back up into
2224 the recursion. However, because of the way PCRE is implemented, this is not
2225 possible, and the result was an incorrect result from the match.
2227 In order to prevent this happening, the specification of recursion has
2228 been changed so that all such subpatterns are automatically treated as
2229 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2231 4. I had overlooked the fact that, in some locales, there are characters for
2232 which isalpha() is true but neither isupper() nor islower() are true. In
2233 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2234 and ordfeminine) are like this. This affected the treatment of \w and \W
2235 when they appeared in character classes, but not when they appeared outside
2236 a character class. The bit map for "word" characters is now created
2237 separately from the results of isalnum() instead of just taking it from the
2238 upper, lower, and digit maps. (Plus the underscore character, of course.)
2240 5. The above bug also affected the handling of POSIX character classes such as
2241 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2242 permanent tables. Instead, the bit maps for such a class were previously
2243 created as the appropriate unions of the upper, lower, and digit bitmaps.
2244 Now they are created by subtraction from the [[:word:]] class, which has
2245 its own bitmap.
2247 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2248 It is created by subtracting the vertical space characters (\x09, \x0a,
2249 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2250 subtraction was done in the overall bitmap for a character class, meaning
2251 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2252 be recognized. This bug has been fixed.
2254 7. Patches from the folks at Google:
2256 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2257 real life, but is still worth protecting against".
2259 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2260 regular expressions".
2262 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2263 have it.
2265 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2266 "configure" and the latter not, in order to fix a problem somebody had
2267 with compiling the Arg class on HP-UX.
2269 (e) Improve the error-handling of the C++ wrapper a little bit.
2271 (f) New tests for checking recursion limiting.
2273 8. The pcre_memmove() function, which is used only if the environment does not
2274 have a standard memmove() function (and is therefore rarely compiled),
2275 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2276 returning a result (though PCRE never actually uses the result).
2278 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2279 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2280 returned instead of calling malloc() with an overflowing number that would
2281 most likely cause subsequent chaos.
2283 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2285 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2286 with this option is matched, the nmatch and pmatch options of regexec() are
2287 ignored.
2289 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2290 provided in case anyone wants to the the POSIX interface with UTF-8
2291 strings.
2293 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2294 C++ linking (needed for some HP-UX environments).
2296 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2297 (unused parameter) and in the pcre_printint() function (omitted "default"
2298 switch label when the default is to do nothing).
2300 15. Added some code to make it possible, when PCRE is compiled as a C++
2301 library, to replace subject pointers for pcre_exec() with a smart pointer
2302 class, thus making it possible to process discontinuous strings.
2304 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2305 much the same function. They were added by different people who were trying
2306 to make PCRE easy to compile on non-Unix systems. It has been suggested
2307 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2308 for compiling on Windows systems. I have therefore replaced it with
2309 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2310 defaults to "extern" for C or "extern C" for C++, which works fine on
2311 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2312 SCOPE with something explicit in config.h. In addition:
2314 (a) pcreposix.h still had just "extern" instead of either of these macros;
2315 I have replaced it with PCRE_DATA_SCOPE.
2317 (b) Functions such as _pcre_xclass(), which are internal to the library,
2318 but external in the C sense, all had PCRE_EXPORT in their definitions.
2319 This is apparently wrong for the Windows case, so I have removed it.
2320 (It makes no difference on Unix-like systems.)
2322 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2323 of recursive calls to match(). This is different to MATCH_LIMIT because
2324 that limits the total number of calls to match(), not all of which increase
2325 the depth of recursion. Limiting the recursion depth limits the amount of
2326 stack (or heap if NO_RECURSE is set) that is used. The default can be set
2327 when PCRE is compiled, and changed at run time. A patch from Google adds
2328 this functionality to the C++ interface.
2330 18. Changes to the handling of Unicode character properties:
2332 (a) Updated the table to Unicode 4.1.0.
2334 (b) Recognize characters that are not in the table as "Cn" (undefined).
2336 (c) I revised the way the table is implemented to a much improved format
2337 which includes recognition of ranges. It now supports the ranges that
2338 are defined in UnicodeData.txt, and it also amalgamates other
2339 characters into ranges. This has reduced the number of entries in the
2340 table from around 16,000 to around 3,000, thus reducing its size
2341 considerably. I realized I did not need to use a tree structure after
2342 all - a binary chop search is just as efficient. Having reduced the
2343 number of entries, I extended their size from 6 bytes to 8 bytes to
2344 allow for more data.
2346 (d) Added support for Unicode script names via properties such as \p{Han}.
2348 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2349 matching that character.
2351 20. When matching a repeated Unicode property with a minimum greater than zero,
2352 (for example \pL{2,}), PCRE could look past the end of the subject if it
2353 reached it while seeking the minimum number of characters. This could
2354 happen only if some of the characters were more than one byte long, because
2355 there is a check for at least the minimum number of bytes.
2357 21. Refactored the implementation of \p and \P so as to be more general, to
2358 allow for more different types of property in future. This has changed the
2359 compiled form incompatibly. Anybody with saved compiled patterns that use
2360 \p or \P will have to recompile them.
2362 22. Added "Any" and "L&" to the supported property types.
2364 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2365 but give a compile time error if the value is greater than 0xff.
2367 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2368 accidentally not being installed or uninstalled.
2370 25. The pcre.h file was built from pcre.h.in, but the only changes that were
2371 made were to insert the current release number. This seemed silly, because
2372 it made things harder for people building PCRE on systems that don't run
2373 "configure". I have turned pcre.h into a distributed file, no longer built
2374 by "configure", with the version identification directly included. There is
2375 no longer a pcre.h.in file.
2377 However, this change necessitated a change to the pcre-config script as
2378 well. It is built from pcre-config.in, and one of the substitutions was the
2379 release number. I have updated configure.ac so that ./configure now finds
2380 the release number by grepping pcre.h.
2382 26. Added the ability to run the tests under valgrind.
2385 Version 6.4 05-Sep-05
2386 ---------------------
2388 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2389 "--" to be printed when multiple files were scanned, even when none of the
2390 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2391 consider it to be a bug, and have restored the previous behaviour.
2393 2. A couple of code tidies to get rid of compiler warnings.
2395 3. The pcretest program used to cheat by referring to symbols in the library
2396 whose names begin with _pcre_. These are internal symbols that are not
2397 really supposed to be visible externally, and in some environments it is
2398 possible to suppress them. The cheating is now confined to including
2399 certain files from the library's source, which is a bit cleaner.
2401 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2402 file's purpose clearer.
2404 5. Reorganized pcre_ucp_findchar().
2407 Version 6.3 15-Aug-05
2408 ---------------------
2410 1. The file libpcre.pc.in did not have general read permission in the tarball.
2412 2. There were some problems when building without C++ support:
2414 (a) If C++ support was not built, "make install" and "make test" still
2415 tried to test it.
2417 (b) There were problems when the value of CXX was explicitly set. Some
2418 changes have been made to try to fix these, and ...
2420 (c) --disable-cpp can now be used to explicitly disable C++ support.
2422 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2423 backslash in a target when C++ was disabled. This confuses some
2424 versions of "make", apparently. Using an intermediate variable solves
2425 this. (Same for CPP_LOBJ.)
2427 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2428 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2429 necessary on certain architectures.
2431 4. Added a setting of -export-symbols-regex to the link command to remove
2432 those symbols that are exported in the C sense, but actually are local
2433 within the library, and not documented. Their names all begin with
2434 "_pcre_". This is not a perfect job, because (a) we have to except some
2435 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2436 available (and never for static libraries). I have made a note to try to
2437 find a way round (a) in the future.
2440 Version 6.2 01-Aug-05
2441 ---------------------
2443 1. There was no test for integer overflow of quantifier values. A construction
2444 such as {1111111111111111} would give undefined results. What is worse, if
2445 a minimum quantifier for a parenthesized subpattern overflowed and became
2446 negative, the calculation of the memory size went wrong. This could have
2447 led to memory overwriting.
2449 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2451 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2452 operating environments where this matters.
2454 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2455 PCRE options from within the C++ wrapper.
2457 5. Named capturing subpatterns were not being correctly counted when a pattern
2458 was compiled. This caused two problems: (a) If there were more than 100
2459 such subpatterns, the calculation of the memory needed for the whole
2460 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2461 back references of the form \12, where the number was greater than 9, were
2462 not recognized as back references, even though there were sufficient
2463 previous subpatterns.
2465 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2466 versions of gcc, e.g. 2.95.4.
2469 Version 6.1 21-Jun-05
2470 ---------------------
2472 1. There was one reference to the variable "posix" in pcretest.c that was not
2473 surrounded by "#if !defined NOPOSIX".
2475 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2476 the cross-check on the old pcre_info() function, for the benefit of the
2477 cut-down version of PCRE that is currently imported into Exim.
2479 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2480 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2481 patterns that start (?i) but I don't think that matters. The use of (?i) is
2482 just an example; this all applies to the other options as well.
2484 4. Since libtool seems to echo the compile commands it is issuing, the output
2485 from "make" can be reduced a bit by putting "@" in front of each libtool
2486 compile command.
2488 5. Patch from the folks at Google for configure.in to be a bit more thorough
2489 in checking for a suitable C++ installation before trying to compile the
2490 C++ stuff. This should fix a reported problem when a compiler was present,
2491 but no suitable headers.
2493 6. The man pages all had just "PCRE" as their title. I have changed them to
2494 be the relevant file name. I have also arranged that these names are
2495 retained in the file doc/pcre.txt, which is a concatenation in text format
2496 of all the man pages except the little individual ones for each function.
2498 7. The NON-UNIX-USE file had not been updated for the different set of source
2499 files that come with release 6. I also added a few comments about the C++
2500 wrapper.
2503 Version 6.0 07-Jun-05
2504 ---------------------
2506 1. Some minor internal re-organization to help with my DFA experiments.
2508 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2509 didn't matter for the library itself when fully configured, but did matter
2510 when compiling without UCP support, or within Exim, where the ucp files are
2511 not imported.
2513 3. Refactoring of the library code to split up the various functions into
2514 different source modules. The addition of the new DFA matching code (see
2515 below) to a single monolithic source would have made it really too
2516 unwieldy, quite apart from causing all the code to be include in a
2517 statically linked application, when only some functions are used. This is
2518 relevant even without the DFA addition now that patterns can be compiled in
2519 one application and matched in another.
2521 The downside of splitting up is that there have to be some external
2522 functions and data tables that are used internally in different modules of
2523 the library but which are not part of the API. These have all had their
2524 names changed to start with "_pcre_" so that they are unlikely to clash
2525 with other external names.
2527 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2528 a different (DFA) algorithm. Although it is slower than the original
2529 function, it does have some advantages for certain types of matching
2530 problem.
2532 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2533 including restarting after a partial match.
2535 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2536 defined when compiling for Windows was sent to me. I have put it into the
2537 code, though I have no means of testing or verifying it.
2539 7. Added the pcre_refcount() auxiliary function.
2541 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2542 match before or at the first newline in the subject string. In pcretest,
2543 the /f option on a pattern can be used to set this.
2545 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2546 would behave wrongly. This has been present in PCRE since release 4.0.
2548 10. A number of changes to the pcregrep command:
2550 (a) Refactored how -x works; insert ^(...)$ instead of setting
2551 PCRE_ANCHORED and checking the length, in preparation for adding
2552 something similar for -w.
2554 (b) Added the -w (match as a word) option.
2556 (c) Refactored the way lines are read and buffered so as to have more
2557 than one at a time available.
2559 (d) Implemented a pcregrep test script.
2561 (e) Added the -M (multiline match) option. This allows patterns to match
2562 over several lines of the subject. The buffering ensures that at least
2563 8K, or the rest of the document (whichever is the shorter) is available
2564 for matching (and similarly the previous 8K for lookbehind assertions).
2566 (f) Changed the --help output so that it now says
2568 -w, --word-regex(p)
2570 instead of two lines, one with "regex" and the other with "regexp"
2571 because that confused at least one person since the short forms are the
2572 same. (This required a bit of code, as the output is generated
2573 automatically from a table. It wasn't just a text change.)
2575 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2576 option but starts with a hyphen. Could be a pattern or a path name
2577 starting with a hyphen, for instance.
2579 (h) "-" can be given as a file name to represent stdin.
2581 (i) When file names are being printed, "(standard input)" is used for
2582 the standard input, for compatibility with GNU grep. Previously
2583 "<stdin>" was used.
2585 (j) The option --label=xxx can be used to supply a name to be used for
2586 stdin when file names are being printed. There is no short form.
2588 (k) Re-factored the options decoding logic because we are going to add
2589 two more options that take data. Such options can now be given in four
2590 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2592 (l) Added the -A, -B, and -C options for requesting that lines of context
2593 around matches be printed.
2595 (m) Added the -L option to print the names of files that do not contain
2596 any matching lines, that is, the complement of -l.
2598 (n) The return code is 2 if any file cannot be opened, but pcregrep does
2599 continue to scan other files.
2601 (o) The -s option was incorrectly implemented. For compatibility with other
2602 greps, it now suppresses the error message for a non-existent or non-
2603 accessible file (but not the return code). There is a new option called
2604 -q that suppresses the output of matching lines, which was what -s was
2605 previously doing.
2607 (p) Added --include and --exclude options to specify files for inclusion
2608 and exclusion when recursing.
2610 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2611 Hopefully, it now does.
2613 12. Missing cast in pcre_study().
2615 13. Added an "uninstall" target to the makefile.
2617 14. Replaced "extern" in the function prototypes in Makefile.in with
2618 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2619 world, but is set differently for Windows.
2621 15. Added a second compiling function called pcre_compile2(). The only
2622 difference is that it has an extra argument, which is a pointer to an
2623 integer error code. When there is a compile-time failure, this is set
2624 non-zero, in addition to the error test pointer being set to point to an
2625 error message. The new argument may be NULL if no error number is required
2626 (but then you may as well call pcre_compile(), which is now just a
2627 wrapper). This facility is provided because some applications need a
2628 numeric error indication, but it has also enabled me to tidy up the way
2629 compile-time errors are handled in the POSIX wrapper.
2631 16. Added VPATH=.libs to the makefile; this should help when building with one
2632 prefix path and installing with another. (Or so I'm told by someone who
2633 knows more about this stuff than I do.)
2635 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2636 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2637 match everything, including newlines. This is not POSIX-compatible, but
2638 somebody wanted the feature. From pcretest it can be activated by using
2639 both the P and the s flags.
2641 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2643 19. libpcre.pc was being incorrectly installed as executable.
2645 20. A couple of places in pcretest check for end-of-line by looking for '\n';
2646 it now also looks for '\r' so that it will work unmodified on Windows.
2648 21. Added Google's contributed C++ wrapper to the distribution.
2650 22. Added some untidy missing memory free() calls in pcretest, to keep
2651 Electric Fence happy when testing.
2655 Version 5.0 13-Sep-04
2656 ---------------------
2658 1. Internal change: literal characters are no longer packed up into items
2659 containing multiple characters in a single byte-string. Each character
2660 is now matched using a separate opcode. However, there may be more than one
2661 byte in the character in UTF-8 mode.
2663 2. The pcre_callout_block structure has two new fields: pattern_position and
2664 next_item_length. These contain the offset in the pattern to the next match
2665 item, and its length, respectively.
2667 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2668 insertion of callouts before each pattern item. Added the /C option to
2669 pcretest to make use of this.
2671 4. On the advice of a Windows user, the lines
2673 #if defined(_WIN32) || defined(WIN32)
2674 _setmode( _fileno( stdout ), 0x8000 );
2675 #endif /* defined(_WIN32) || defined(WIN32) */
2677 have been added to the source of pcretest. This apparently does useful
2678 magic in relation to line terminators.
2680 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2681 for the benefit of those environments where the "b" makes a difference.
2683 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2684 to know about it. I have put a hack into configure.in that adds in code
2685 to set GCC=yes if CC=icc. This seems to end up at a point in the
2686 generated configure script that is early enough to affect the setting of
2687 compiler options, which is what is needed, but I have no means of testing
2688 whether it really works. (The user who reported this had patched the
2689 generated configure script, which of course I cannot do.)
2691 LATER: After change 22 below (new libtool files), the configure script
2692 seems to know about icc (and also ecc). Therefore, I have commented out
2693 this hack in configure.in.
2695 7. Added support for pkg-config (2 patches were sent in).
2697 8. Negated POSIX character classes that used a combination of internal tables
2698 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2699 [[:^ascii]]. Typically, they would match almost any characters. The other
2700 POSIX classes were not broken in this way.
2702 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2703 to find the match, as PCRE was deluded into thinking that the match had to
2704 start at the start point or following a newline. The same bug applied to
2705 patterns with negative forward assertions or any backward assertions
2706 preceding ".*" at the start, unless the pattern required a fixed first
2707 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2709 10. In UTF-8 mode, when moving forwards in the subject after a failed match
2710 starting at the last subject character, bytes beyond the end of the subject
2711 string were read.
2713 11. Renamed the variable "class" as "classbits" to make life easier for C++
2714 users. (Previously there was a macro definition, but it apparently wasn't
2715 enough.)
2717 12. Added the new field "tables" to the extra data so that tables can be passed
2718 in at exec time, or the internal tables can be re-selected. This allows
2719 a compiled regex to be saved and re-used at a later time by a different
2720 program that might have everything at different addresses.
2722 13. Modified the pcre-config script so that, when run on Solaris, it shows a
2723 -R library as well as a -L library.
2725 14. The debugging options of pcretest (-d on the command line or D on a
2726 pattern) showed incorrect output for anything following an extended class
2727 that contained multibyte characters and which was followed by a quantifier.
2729 15. Added optional support for general category Unicode character properties
2730 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2731 support. It adds about 90K to the size of the library. The meanings of the
2732 inbuilt class escapes such as \d and \s have NOT been changed.
2734 16. Updated pcredemo.c to include calls to free() to release the memory for the
2735 compiled pattern.
2737 17. The generated file chartables.c was being created in the source directory
2738 instead of in the building directory. This caused the build to fail if the
2739 source directory was different from the building directory, and was
2740 read-only.
2742 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2743 file. No doubt somebody will tell me if they don't make sense... Also added
2744 Dan Mooney's comments about building on OpenVMS.
2746 19. Added support for partial matching via the PCRE_PARTIAL option for
2747 pcre_exec() and the \P data escape in pcretest.
2749 20. Extended pcretest with 3 new pattern features:
2751 (i) A pattern option of the form ">rest-of-line" causes pcretest to
2752 write the compiled pattern to the file whose name is "rest-of-line".
2753 This is a straight binary dump of the data, with the saved pointer to
2754 the character tables forced to be NULL. The study data, if any, is
2755 written too. After writing, pcretest reads a new pattern.
2757 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2758 compiled pattern from the given file. There must not be any
2759 occurrences of "<" in the file name (pretty unlikely); if there are,
2760 pcretest will instead treat the initial "<" as a pattern delimiter.
2761 After reading in the pattern, pcretest goes on to read data lines as
2762 usual.
2764 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2765 and 16-bit fields in a compiled pattern, to simulate a pattern that
2766 was compiled on a host of opposite endianness.
2768 21. The pcre-exec() function can now cope with patterns that were compiled on
2769 hosts of opposite endianness, with this restriction:
2771 As for any compiled expression that is saved and used later, the tables
2772 pointer field cannot be preserved; the extra_data field in the arguments
2773 to pcre_exec() should be used to pass in a tables address if a value
2774 other than the default internal tables were used at compile time.
2776 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2777 now diagnosed as an error. Previously, most of the time, a negative number
2778 would have been treated as zero, but if in addition "ovector" was passed as
2779 NULL, a crash could occur.
2781 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2782 new versions from the libtool 1.5 distribution (the last one is a copy of
2783 a file called libtool.m4). This seems to have fixed the need to patch
2784 "configure" to support Darwin 1.3 (which I used to do). However, I still
2785 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2786 workstation).
2788 24. Changed the PCRE licence to be the more standard "BSD" licence.
2791 Version 4.5 01-Dec-03
2792 ---------------------
2794 1. There has been some re-arrangement of the code for the match() function so
2795 that it can be compiled in a version that does not call itself recursively.
2796 Instead, it keeps those local variables that need separate instances for
2797 each "recursion" in a frame on the heap, and gets/frees frames whenever it
2798 needs to "recurse". Keeping track of where control must go is done by means
2799 of setjmp/longjmp. The whole thing is implemented by a set of macros that
2800 hide most of the details from the main code, and operates only if
2801 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2802 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2803 operating.
2805 To make it easier for callers to provide specially tailored get/free
2806 functions for this usage, two new functions, pcre_stack_malloc, and
2807 pcre_stack_free, are used. They are always called in strict stacking order,
2808 and the size of block requested is always the same.
2810 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2811 PCRE has been compiled to use the stack or the heap for recursion. The
2812 -C option of pcretest uses this to show which version is compiled.
2814 A new data escape \S, is added to pcretest; it causes the amounts of store
2815 obtained and freed by both kinds of malloc/free at match time to be added
2816 to the output.
2818 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2819 what's available on my current Linux desktop machine.
2821 3. When matching a UTF-8 string, the test for a valid string at the start has
2822 been extended. If start_offset is not zero, PCRE now checks that it points
2823 to a byte that is the start of a UTF-8 character. If not, it returns
2824 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2825 this is necessary because there may be backward assertions in the pattern.
2826 When matching the same subject several times, it may save resources to use
2827 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2829 4. The code for checking the validity of UTF-8 strings has been tightened so
2830 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2831 containing "overlong sequences".
2833 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2834 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2835 should have been "&", but it just so happened that all the cases this let
2836 through by mistake were picked up later in the function.
2838 6. I had used a variable called "isblank" - this is a C99 function, causing
2839 some compilers to warn. To avoid this, I renamed it (as "blankclass").
2841 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2842 prompting; (b) run "./pcretest /dev/null" at the start of the test script
2843 so the version is shown; (c) stop "make test" echoing "./RunTest".
2845 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2847 9. The prototype for memmove() for systems that don't have it was using
2848 size_t, but the inclusion of the header that defines size_t was later. I've
2849 moved the #includes for the C headers earlier to avoid this.
2851 10. Added some adjustments to the code to make it easier to compiler on certain
2852 special systems:
2854 (a) Some "const" qualifiers were missing.
2855 (b) Added the macro EXPORT before all exported functions; by default this
2856 is defined to be empty.
2857 (c) Changed the dftables auxiliary program (that builds chartables.c) so
2858 that it reads its output file name as an argument instead of writing
2859 to the standard output and assuming this can be redirected.
2861 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2862 class containing characters with values greater than 255, PCRE compilation
2863 went into a loop.
2865 12. A recursive reference to a subpattern that was within another subpattern
2866 that had a minimum quantifier of zero caused PCRE to crash. For example,
2867 (x(y(?2))z)? provoked this bug with a subject that got as far as the
2868 recursion. If the recursively-called subpattern itself had a zero repeat,
2869 that was OK.
2871 13. In pcretest, the buffer for reading a data line was set at 30K, but the
2872 buffer into which it was copied (for escape processing) was still set at
2873 1024, so long lines caused crashes.
2875 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2876 "internal error: code overflow...". This applied to any character class
2877 that was followed by a possessive quantifier.
2879 15. Modified the Makefile to add libpcre.la as a prerequisite for
2880 libpcreposix.la because I was told this is needed for a parallel build to
2881 work.
2883 16. If a pattern that contained .* following optional items at the start was
2884 studied, the wrong optimizing data was generated, leading to matching
2885 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2886 matching string must start with a or b or c. The correct conclusion for
2887 this pattern is that a match can start with any character.
2890 Version 4.4 13-Aug-03
2891 ---------------------
2893 1. In UTF-8 mode, a character class containing characters with values between
2894 127 and 255 was not handled correctly if the compiled pattern was studied.
2895 In fixing this, I have also improved the studying algorithm for such
2896 classes (slightly).
2898 2. Three internal functions had redundant arguments passed to them. Removal
2899 might give a very teeny performance improvement.
2901 3. Documentation bug: the value of the capture_top field in a callout is *one
2902 more than* the number of the hightest numbered captured substring.
2904 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2905 in incorrectly linking with a previously installed version. They now link
2906 explicitly with libpcre.la.
2908 5. configure.in no longer needs to recognize Cygwin specially.
2910 6. A problem in pcre.in for Windows platforms is fixed.
2912 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2913 pcretest, it used to include the size of the study block as part of its
2914 output. Unfortunately, the structure contains a field that has a different
2915 size on different hardware architectures. This meant that the tests that
2916 showed this size failed. As the block is currently always of a fixed size,
2917 this information isn't actually particularly useful in pcretest output, so
2918 I have just removed it.
2920 8. Three pre-processor statements accidentally did not start in column 1.
2921 Sadly, there are *still* compilers around that complain, even though
2922 standard C has not required this for well over a decade. Sigh.
2924 9. In pcretest, the code for checking callouts passed small integers in the
2925 callout_data field, which is a void * field. However, some picky compilers
2926 complained about the casts involved for this on 64-bit systems. Now
2927 pcretest passes the address of the small integer instead, which should get
2928 rid of the warnings.
2930 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2931 both compile and run time, and gives an error if an invalid UTF-8 sequence
2932 is found. There is a option for disabling this check in cases where the
2933 string is known to be correct and/or the maximum performance is wanted.
2935 11. In response to a bug report, I changed one line in Makefile.in from
2937 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2938 to
2939 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2941 to look similar to other lines, but I have no way of telling whether this
2942 is the right thing to do, as I do not use Windows. No doubt I'll get told
2943 if it's wrong...
2946 Version 4.3 21-May-03
2947 ---------------------
2949 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2950 Makefile.
2952 2. Some refactoring to improve the quality of the code:
2954 (i) The utf8_table... variables are now declared "const".
2956 (ii) The code for \cx, which used the "case flipping" table to upper case
2957 lower case letters, now just substracts 32. This is ASCII-specific,
2958 but the whole concept of \cx is ASCII-specific, so it seems
2959 reasonable.
2961 (iii) PCRE was using its character types table to recognize decimal and
2962 hexadecimal digits in the pattern. This is silly, because it handles
2963 only 0-9, a-f, and A-F, but the character types table is locale-
2964 specific, which means strange things might happen. A private
2965 table is now used for this - though it costs 256 bytes, a table is
2966 much faster than multiple explicit tests. Of course, the standard
2967 character types table is still used for matching digits in subject
2968 strings against \d.
2970 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2971 ending in _t are). So I've renamed it as ESC_tee.
2973 3. The first argument for regexec() in the POSIX wrapper should have been
2974 defined as "const".
2976 4. Changed pcretest to use malloc() for its buffers so that they can be
2977 Electric Fenced for debugging.
2979 5. There were several places in the code where, in UTF-8 mode, PCRE would try
2980 to read one or more bytes before the start of the subject string. Often this
2981 had no effect on PCRE's behaviour, but in some circumstances it could
2982 provoke a segmentation fault.
2984 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2985 to try to read one or more bytes before the start of the subject string.
2987 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2988 UTF-8 support could misbehave in various ways if the subject string
2989 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2990 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2991 back over UTF-8 characters.)
2994 Version 4.2 14-Apr-03
2995 ---------------------
2997 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2999 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3000 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3001 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3002 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3003 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3005 Note: automatic setting of the BUILD variables is not yet working
3006 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3007 compile-time but not at link-time
3008 [LINK]: use for linking executables only
3009 make different versions for Windows and non-Windows
3010 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3011 libraries
3012 [LINK_FOR_BUILD]: new variable
3013 [OBJEXT]: use throughout
3014 [EXEEXT]: use throughout
3015 <winshared>: new target
3016 <wininstall>: new target
3017 <dftables.o>: use native compiler
3018 <dftables>: use native linker
3019 <install>: handle Windows platform correctly
3020 <clean>: ditto
3021 <check>: ditto
3022 copy DLL to top builddir before testing
3024 As part of these changes, -no-undefined was removed again. This was reported
3025 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3026 in any case.
3028 3. Some tidies to get rid of compiler warnings:
3030 . In the match_data structure, match_limit was an unsigned long int, whereas
3031 match_call_count was an int. I've made them both unsigned long ints.
3033 . In pcretest the fact that a const uschar * doesn't automatically cast to
3034 a void * provoked a warning.
3036 . Turning on some more compiler warnings threw up some "shadow" variables
3037 and a few more missing casts.
3039 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3040 option, a class that contained a single character with a value between 128
3041 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3043 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3044 option, a class that contained several characters, but with at least one
3045 whose value was between 128 and 255 caused PCRE to crash.
3048 Version 4.1 12-Mar-03
3049 ---------------------
3051 1. Compiling with gcc -pedantic found a couple of places where casts were
3052 needed, and a string in dftables.c that was longer than standard compilers are
3053 required to support.
3055 2. Compiling with Sun's compiler found a few more places where the code could
3056 be tidied up in order to avoid warnings.
3058 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3059 first of these names is deprecated in the latest Autoconf in favour of the name
3060 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3061 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3062 analogy I have changed it to CFLAGS_FOR_BUILD.
3064 4. Added -no-undefined to the linking command in the Makefile, because this is
3065 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3066 linking step for the pcreposix library.
3068 5. PCRE was failing to diagnose the case of two named groups with the same
3069 name.
3071 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3072 literal character that is needed in the subject for a match, and scans along to
3073 ensure that it is present before embarking on the full matching process. This
3074 saves time in cases of nested unlimited repeats that are never going to match.
3075 Problem: the scan can take a lot of time if the subject is very long (e.g.
3076 megabytes), thus penalizing straightforward matches. It is now done only if the
3077 amount of subject to be scanned is less than 1000 bytes.
3079 7. A lesser problem with the same optimization is that it was recording the
3080 first character of an anchored pattern as "needed", thus provoking a search
3081 right along the subject, even when the first match of the pattern was going to
3082 fail. The "needed" character is now not set for anchored patterns, unless it
3083 follows something in the pattern that is of non-fixed length. Thus, it still
3084 fulfils its original purpose of finding quick non-matches in cases of nested
3085 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3088 Version 4.0 17-Feb-03
3089 ---------------------
3091 1. If a comment in an extended regex that started immediately after a meta-item
3092 extended to the end of string, PCRE compiled incorrect data. This could lead to
3093 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3095 2. Moved to autoconf 2.53 and libtool 1.4.2.
3097 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3098 the special perltest8 script is no longer needed - all the tests can be run
3099 from a single perltest script.
3101 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3102 by \s. It has now been removed in PCRE. This means it isn't recognized as
3103 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3104 class [:space:] *does* include VT, thereby creating a mess.
3106 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3107 space and tab.
3109 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3110 its new features into the main test script, reducing the number of scripts.
3112 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3113 were backward compatible, and made the (?i) apply to the whole pattern, as if
3114 /i were given. Now it behaves more logically, and applies the option setting
3115 only to what follows. PCRE has been changed to follow suit. However, if it
3116 finds options settings right at the start of the pattern, it extracts them into
3117 the global options, as before. Thus, they show up in the info data.
3119 8. Added support for the \Q...\E escape sequence. Characters in between are
3120 treated as literals. This is slightly different from Perl in that $ and @ are
3121 also handled as literals inside the quotes. In Perl, they will cause variable
3122 interpolation. Note the following examples:
3124 Pattern PCRE matches Perl matches
3126 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3127 \Qabc\$xyz\E abc\$xyz abc\$xyz
3128 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3130 For compatibility with Perl, \Q...\E sequences are recognized inside character
3131 classes as well as outside them.
3133 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3134 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3135 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3136 signed/unsigned warnings.
3138 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3139 option for pcretest, so I've replaced it by a simple function that does just
3140 that job.
3142 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3143 "pcregrep -".
3145 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3146 Java package. This provides some syntactic sugar for simple cases of what my
3147 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3148 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3149 item, you can use this simplified notation. Note that only makes sense with
3150 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3151 greediness, whatever the setting of the PCRE_UNGREEDY option.
3153 13. A change of greediness default within a pattern was not taking effect at
3154 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3155 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3156 was abstracted outside.
3158 14. PCRE now supports the \G assertion. It is true when the current matching
3159 position is at the start point of the match. This differs from \A when the
3160 starting offset is non-zero. Used with the /g option of pcretest (or similar
3161 code), it works in the same way as it does for Perl's /g option. If all
3162 alternatives of a regex begin with \G, the expression is anchored to the start
3163 match position, and the "anchored" flag is set in the compiled expression.
3165 15. Some bugs concerning the handling of certain option changes within patterns
3166 have been fixed. These applied to options other than (?ims). For example,
3167 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3168 been the other way round. Some of this was related to change 7 above.
3170 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3171 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3172 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3173 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3175 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3176 mode. Unlike ".", it always matches newline, whatever the setting of
3177 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3178 assertions. Perl allows it, but it doesn't (in general) work because it can't
3179 calculate the length of the lookbehind. At least, that's the case for Perl
3180 5.8.0 - I've been told they are going to document that it doesn't work in
3181 future.
3183 18. Added an error diagnosis for escapes that PCRE does not support: these are
3184 \L, \l, \N, \P, \p, \U, \u, and \X.
3186 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3187 reading past the end of the pattern in cases such as /[abcd/.
3189 20. PCRE was getting more memory than necessary for patterns with classes that
3190 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3192 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3193 compiling PCRE for use with Virtual Pascal.
3195 22. Small fix to the Makefile to make it work properly if the build is done
3196 outside the source tree.
3198 23. Added a new extension: a condition to go with recursion. If a conditional
3199 subpattern starts with (?(R) the "true" branch is used if recursion has
3200 happened, whereas the "false" branch is used only at the top level.
3202 24. When there was a very long string of literal characters (over 255 bytes
3203 without UTF support, over 250 bytes with UTF support), the computation of how
3204 much memory was required could be incorrect, leading to segfaults or other
3205 strange effects.
3207 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3208 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3209 there was a subsequent back reference to those brackets. This meant that, for
3210 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3211 possible to check for precisely this case. All we can do is abandon the
3212 optimization if .* occurs inside capturing brackets when there are any back
3213 references whatsoever. (See below for a better fix that came later.)
3215 26. The handling of the optimization for finding the first character of a
3216 non-anchored pattern, and for finding a character that is required later in the
3217 match were failing in some cases. This didn't break the matching; it just
3218 failed to optimize when it could. The way this is done has been re-implemented.
3220 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3222 28. Added a new feature that provides some of the functionality that Perl
3223 provides with (?{...}). The facility is termed a "callout". The way it is done
3224 in PCRE is for the caller to provide an optional function, by setting
3225 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3226 global variable. By default it is unset, which disables all calling out. To get
3227 the function called, the regex must include (?C) at appropriate points. This
3228 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3229 This provides a means of identifying different callout points. When PCRE
3230 reaches such a point in the regex, if pcre_callout has been set, the external
3231 function is called. It is provided with data in a structure called
3232 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3233 matching continues; if it returns a non-zero value, the match at the current
3234 point fails. However, backtracking will occur if possible. [This was changed
3235 later and other features added - see item 49 below.]
3237 29. pcretest is upgraded to test the callout functionality. It provides a
3238 callout function that displays information. By default, it shows the start of
3239 the match and the current position in the text. There are some new data escapes
3240 to vary what happens:
3242 \C+ in addition, show current contents of captured substrings
3243 \C- do not supply a callout function
3244 \C!n return 1 when callout number n is reached
3245 \C!n!m return 1 when callout number n is reached for the mth time
3247 30. If pcregrep was called with the -l option and just a single file name, it
3248 output "<stdin>" if a match was found, instead of the file name.
3250 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3251 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3252 pcre_exec(). This saves a malloc/free per call. The default value of
3253 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3254 when configuring.
3256 32. The default maximum size of a compiled pattern is 64K. There have been a
3257 few cases of people hitting this limit. The code now uses macros to handle the
3258 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3259 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3260 configuring. Tests 2 and 5 work only with 2-byte links because they output
3261 debugging information about compiled patterns.
3263 33. Internal code re-arrangements:
3265 (a) Moved the debugging function for printing out a compiled regex into
3266 its own source file (printint.c) and used #include to pull it into
3267 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3268 separate copies.
3270 (b) Defined the list of op-code names for debugging as a macro in
3271 internal.h so that it is next to the definition of the opcodes.
3273 (c) Defined a table of op-code lengths for simpler skipping along compiled
3274 code. This is again a macro in internal.h so that it is next to the
3275 definition of the opcodes.
3277 34. Added support for recursive calls to individual subpatterns, along the
3278 lines of Robin Houston's patch (but implemented somewhat differently).
3280 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3281 allow it to read and process whole directories in Win32. This code was
3282 contributed by Lionel Fourquaux; it has not been tested by me.
3284 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3285 used to name a group. Names consist of alphanumerics and underscores, and must
3286 be unique. Back references use the syntax (?P=name) and recursive calls use
3287 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3288 numbers. The function pcre_fullinfo() can be used after compilation to extract
3289 a name/number map. There are three relevant calls:
3291 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3292 PCRE_INFO_NAMECOUNT yields the number of entries
3293 PCRE_INFO_NAMETABLE yields a pointer to the map.
3295 The map is a vector of fixed-size entries. The size of each entry depends on
3296 the length of the longest name used. The first two bytes of each entry are the
3297 group number, most significant byte first. There follows the corresponding
3298 name, zero terminated. The names are in alphabetical order.
3300 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3301 case instead of 255. Making it the same both with and without UTF-8 support
3302 means that the same test output works with both.
3304 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3305 calling malloc() with a zero argument.
3307 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3308 optimization. I've improved things by keeping a bitmap of backreferences with
3309 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3310 fact referenced, the optimization can be applied. It is unlikely that a
3311 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3312 the match to follow \n) will appear inside brackets with a number greater than
3313 31, but if it does, any back reference > 31 suppresses the optimization.
3315 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3316 of disabling numbered capturing parentheses. Any opening parenthesis that is
3317 not followed by ? behaves as if it were followed by ?: but named parentheses
3318 can still be used for capturing (and they will acquire numbers in the usual
3319 way).
3321 41. Redesigned the return codes from the match() function into yes/no/error so
3322 that errors can be passed back from deep inside the nested calls. A malloc
3323 failure while inside a recursive subpattern call now causes the
3324 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3326 42. It is now possible to set a limit on the number of times the match()
3327 function is called in a call to pcre_exec(). This facility makes it possible to
3328 limit the amount of recursion and backtracking, though not in a directly
3329 obvious way, because the match() function is used in a number of different
3330 circumstances. The count starts from zero for each position in the subject
3331 string (for non-anchored patterns). The default limit is, for compatibility, a
3332 large number, namely 10 000 000. You can change this in two ways:
3334 (a) When configuring PCRE before making, you can use --with-match-limit=n
3335 to set a default value for the compiled library.
3337 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3338 a different value is set. See 45 below.
3340 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3342 43. Added a new function pcre_config(int, void *) to enable run-time extraction
3343 of things that can be changed at compile time. The first argument specifies
3344 what is wanted and the second points to where the information is to be placed.
3345 The current list of available information is:
3349 The output is an integer that is set to one if UTF-8 support is available;
3350 otherwise it is set to zero.
3354 The output is an integer that it set to the value of the code that is used for
3355 newline. It is either LF (10) or CR (13).
3359 The output is an integer that contains the number of bytes used for internal
3360 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3364 The output is an integer that contains the threshold above which the POSIX
3365 interface uses malloc() for output vectors. See item 31 above.
3369 The output is an unsigned integer that contains the default limit of the number
3370 of match() calls in a pcre_exec() execution. See 42 above.
3372 44. pcretest has been upgraded by the addition of the -C option. This causes it
3373 to extract all the available output from the new pcre_config() function, and to
3374 output it. The program then exits immediately.
3376 45. A need has arisen to pass over additional data with calls to pcre_exec() in
3377 order to support additional features. One way would have been to define
3378 pcre_exec2() (for example) with extra arguments, but this would not have been
3379 extensible, and would also have required all calls to the original function to
3380 be mapped to the new one. Instead, I have chosen to extend the mechanism that
3381 is used for passing in "extra" data from pcre_study().
3383 The pcre_extra structure is now exposed and defined in pcre.h. It currently
3384 contains the following fields:
3386 flags a bitmap indicating which of the following fields are set
3387 study_data opaque data from pcre_study()
3388 match_limit a way of specifying a limit on match() calls for a specific
3389 call to pcre_exec()
3390 callout_data data for callouts (see 49 below)
3392 The flag bits are also defined in pcre.h, and are
3398 The pcre_study() function now returns one of these new pcre_extra blocks, with
3399 the actual study data pointed to by the study_data field, and the
3400 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3401 before. That is, this change is entirely upwards-compatible and requires no
3402 change to existing code.
3404 If you want to pass in additional data to pcre_exec(), you can either place it
3405 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3406 block.
3408 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3409 data string contains the escape sequence \M, pcretest calls pcre_exec() several
3410 times with different match limits, until it finds the minimum value needed for
3411 pcre_exec() to complete. The value is then output. This can be instructive; for
3412 most simple matches the number is quite small, but for pathological cases it
3413 gets very large very quickly.
3415 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3416 returns the size of the data block pointed to by the study_data field in a
3417 pcre_extra block, that is, the value that was passed as the argument to
3418 pcre_malloc() when PCRE was getting memory in which to place the information
3419 created by pcre_study(). The fourth argument should point to a size_t variable.
3420 pcretest has been extended so that this information is shown after a successful
3421 pcre_study() call when information about the compiled regex is being displayed.
3423 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3424 because what follows is always an absolute path. (Later: it turns out that this
3425 is more than cosmetic for MinGW, because it doesn't like empty path
3426 components.)
3428 49. Some changes have been made to the callout feature (see 28 above):
3430 (i) A callout function now has three choices for what it returns:
3432 0 => success, carry on matching
3433 > 0 => failure at this point, but backtrack if possible
3434 < 0 => serious error, return this value from pcre_exec()
3436 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3437 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3438 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3439 use by callout functions. It will never be used by PCRE itself.
3441 (ii) The pcre_extra structure (see 45 above) has a void * field called
3442 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3443 pcre_callout_block structure has a field of the same name. The contents of
3444 the field passed in the pcre_extra structure are passed to the callout
3445 function in the corresponding field in the callout block. This makes it
3446 easier to use the same callout-containing regex from multiple threads. For
3447 testing, the pcretest program has a new data escape
3449 \C*n pass the number n (may be negative) as callout_data
3451 If the callout function in pcretest receives a non-zero value as
3452 callout_data, it returns that value.
3454 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3455 there were some redundant $(CFLAGS) in commands that are now specified as
3456 $(LINK), which already includes $(CFLAGS).
3458 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3459 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3460 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3461 one-byte characters throughout. Note that case-insensitive matching applies
3462 only to characters whose values are less than 256. PCRE doesn't support the
3463 notion of cases for higher-valued characters.
3465 (i) A character class whose characters are all within 0-255 is handled as
3466 a bit map, and the map is inverted for negative classes. Previously, a
3467 character > 255 always failed to match such a class; however it should
3468 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3470 (ii) A negated character class with a single character < 255 is coded as
3471 "not this character" (OP_NOT). This wasn't working properly when the test
3472 character was multibyte, either singly or repeated.
3474 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3475 mode, for example: \x{100}{2,3}.
3477 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3478 singly or repeated) now correctly test multibyte characters. However,
3479 PCRE doesn't recognize any characters with values greater than 255 as
3480 digits, spaces, or word characters. Such characters always match \D, \S,
3481 and \W, and never match \d, \s, or \w.
3483 (v) Classes may now contain characters and character ranges with values
3484 greater than 255. For example: [ab\x{100}-\x{400}].
3486 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3487 PCRE in UTF-8 mode.
3489 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3490 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3491 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3492 value.)
3494 53. The single man page has become too large. I have therefore split it up into
3495 a number of separate man pages. These also give rise to individual HTML pages;
3496 these are now put in a separate directory, and there is an index.html page that
3497 lists them all. Some hyperlinking between the pages has been installed.
3499 54. Added convenience functions for handling named capturing parentheses.
3501 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3502 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3503 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3504 are faulted.
3506 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3507 calling configure. These values are used when compiling the dftables.c program
3508 which is run to generate the source of the default character tables. They
3509 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3510 you will need to set these values.
3512 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3515 Version 3.9 02-Jan-02
3516 ---------------------
3518 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3520 2. If --disable-static was given, the building process failed when trying to
3521 build pcretest and pcregrep. (For some reason it was using libtool to compile
3522 them, which is not right, as they aren't part of the library.)
3525 Version 3.8 18-Dec-01
3526 ---------------------
3528 1. The experimental UTF-8 code was completely screwed up. It was packing the
3529 bytes in the wrong order. How dumb can you get?
3532 Version 3.7 29-Oct-01
3533 ---------------------
3535 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3536 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3537 this didn't happen under Solaris 8, where I normally test things.
3539 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3540 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3541 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3542 this fix an hour or so after the initial 3.7 release.)
3545 Version 3.6 23-Oct-01
3546 ---------------------
3548 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3549 offsets passed as NULL with zero offset count.
3551 2. The config.guess and config.sub files had not been updated when I moved to
3552 the latest autoconf.
3555 Version 3.5 15-Aug-01
3556 ---------------------
3558 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3559 had been forgotten.
3561 2. By using declared but undefined structures, we can avoid using "void"
3562 definitions in pcre.h while keeping the internal definitions of the structures
3563 private.
3565 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3566 user point of view, this means that both static and shared libraries are built
3567 by default, but this can be individually controlled. More of the work of
3568 handling this static/shared cases is now inside libtool instead of PCRE's make
3569 file.
3571 4. The pcretest utility is now installed along with pcregrep because it is
3572 useful for users (to test regexs) and by doing this, it automatically gets
3573 relinked by libtool. The documentation has been turned into a man page, so
3574 there are now .1, .txt, and .html versions in /doc.
3576 5. Upgrades to pcregrep:
3577 (i) Added long-form option names like gnu grep.
3578 (ii) Added --help to list all options with an explanatory phrase.
3579 (iii) Added -r, --recursive to recurse into sub-directories.
3580 (iv) Added -f, --file to read patterns from a file.
3582 6. pcre_exec() was referring to its "code" argument before testing that
3583 argument for NULL (and giving an error if it was NULL).
3585 7. Upgraded Makefile.in to allow for compiling in a different directory from
3586 the source directory.
3588 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3589 options bits, the pointer it was passed was to an int instead of to an unsigned
3590 long int. This mattered only on 64-bit systems.
3592 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3593 generated) instead of pcre.in, which it its source. Also made the same change
3594 in several of the .c files.
3596 10. A new release of gcc defines printf() as a macro, which broke pcretest
3597 because it had an ifdef in the middle of a string argument for printf(). Fixed
3598 by using separate calls to printf().
3600 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3601 script, to force use of CR or LF instead of \n in the source. On non-Unix
3602 systems, the value can be set in config.h.
3604 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3605 absolute limit. Changed the text of the error message to make this clear, and
3606 likewise updated the man page.
3608 13. The limit of 99 on the number of capturing subpatterns has been removed.
3609 The new limit is 65535, which I hope will not be a "real" limit.
3612 Version 3.4 22-Aug-00
3613 ---------------------
3615 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3617 2. Diagnose condition (?(0) as an error instead of crashing on matching.
3620 Version 3.3 01-Aug-00
3621 ---------------------
3623 1. If an octal character was given, but the value was greater than \377, it
3624 was not getting masked to the least significant bits, as documented. This could
3625 lead to crashes in some systems.
3627 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3628 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3630 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3631 These just pass their arguments on to (pcre_free)(), but they are provided
3632 because some uses of PCRE bind it to non-C systems that can call its functions,
3633 but cannot call free() or pcre_free() directly.
3635 4. Add "make test" as a synonym for "make check". Corrected some comments in
3636 the Makefile.
3638 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3639 Makefile.
3641 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3642 command called pgrep for grepping around the active processes.
3644 7. Added the beginnings of support for UTF-8 character strings.
3646 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3647 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3648 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3649 out for the ar command.)
3652 Version 3.2 12-May-00
3653 ---------------------
3655 This is purely a bug fixing release.
3657 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3658 of ZA. This was just one example of several cases that could provoke this bug,
3659 which was introduced by change 9 of version 2.00. The code for breaking
3660 infinite loops after an iteration that matches an empty string was't working
3661 correctly.
3663 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3664 when matched against abbab (for example). After matching an empty string, it
3665 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3666 caused it to match further down the string than it should.
3668 3. The code contained an inclusion of sys/types.h. It isn't clear why this
3669 was there because it doesn't seem to be needed, and it causes trouble on some
3670 systems, as it is not a Standard C header. It has been removed.
3672 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3673 were reported on the Macintosh. The changes were from
3675 while ((c = *(++ptr)) != 0 && c != '\n');
3676 to
3677 while ((c = *(++ptr)) != 0 && c != '\n') ;
3679 Totally extraordinary, but if that's what it takes...
3681 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3682 available. Added HAVE_BCOPY and an autoconf test for it; if neither
3683 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3684 assumes the way PCRE uses memmove() (always moving upwards).
3686 6. PCRE is being used in one environment where strchr() is not available. There
3687 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3688 faster code anyway.
3691 Version 3.1 09-Feb-00
3692 ---------------------
3694 The only change in this release is the fixing of some bugs in Makefile.in for
3695 the "install" target:
3697 (1) It was failing to install pcreposix.h.
3699 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3702 Version 3.0 01-Feb-00
3703 ---------------------
3705 1. Add support for the /+ modifier to perltest (to output $` like it does in
3706 pcretest).
3708 2. Add support for the /g modifier to perltest.
3710 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3711 matches null strings.
3713 4. Fix perltest so that it doesn't do unwanted things when fed an empty
3714 pattern. Perl treats empty patterns specially - it reuses the most recent
3715 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3716 effect.
3718 5. The POSIX interface was broken in that it was just handing over the POSIX
3719 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3720 required a bigger vector, with some working space on the end. This means that
3721 the POSIX wrapper now has to get and free some memory, and copy the results.
3723 6. Added some simple autoconf support, placing the test data and the
3724 documentation in separate directories, re-organizing some of the
3725 information files, and making it build pcre-config (a GNU standard). Also added
3726 libtool support for building PCRE as a shared library, which is now the
3727 default.
3729 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3730 09 are not valid octal constants. Single digits will be used for minor values
3731 less than 10.
3733 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3734 existing programs that set these in the POSIX interface can use PCRE without
3735 modification.
3737 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3738 return all that pcre_info() returns, plus additional data. The pcre_info()
3739 function is retained for compatibility, but is considered to be obsolete.
3741 10. Added experimental recursion feature (?R) to handle one common case that
3742 Perl 5.6 will be able to do with (?p{...}).
3744 11. Added support for POSIX character classes like [:alpha:], which Perl is
3745 adopting.
3748 Version 2.08 31-Aug-99
3749 ----------------------
3751 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3752 trying to match at the startoffset position, but instead was moving forward to
3753 the next newline as if a previous match had failed.
3755 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3756 and could get into a loop if a null string was matched other than at the start
3757 of the subject.
3759 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3760 be distinguished at compile time, and for completeness also added PCRE_DATE.
3762 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3763 in GnuWin32 environments.
3766 Version 2.07 29-Jul-99
3767 ----------------------
3769 1. The documentation is now supplied in plain text form and HTML as well as in
3770 the form of man page sources.
3772 2. C++ compilers don't like assigning (void *) values to other pointer types.
3773 In particular this affects malloc(). Although there is no problem in Standard
3774 C, I've put in casts to keep C++ compilers happy.
3776 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3777 should be (const char *).
3779 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3780 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3781 However, I haven't made this a standard facility. The documentation doesn't
3782 mention it, and the Makefile doesn't support it.
3784 5. The Makefile now contains an "install" target, with editable destinations at
3785 the top of the file. The pcretest program is not installed.
3787 6. pgrep -V now gives the PCRE version number and date.
3789 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3790 causing the entire string to be ignored, instead of just the last character.
3792 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3793 non-matching string, it can take a very, very long time, even for strings of
3794 quite modest length, because of the nested recursion. PCRE now does better in
3795 some of these cases. It does this by remembering the last required literal
3796 character in the pattern, and pre-searching the subject to ensure it is present
3797 before running the real match. In other words, it applies a heuristic to detect
3798 some types of certain failure quickly, and in the above example, if presented
3799 with a string that has no trailing " it gives "no match" very quickly.
3801 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3802 other alternatives are tried instead.
3805 Version 2.06 09-Jun-99
3806 ----------------------
3808 1. Change pcretest's output for amount of store used to show just the code
3809 space, because the remainder (the data block) varies in size between 32-bit and
3810 64-bit systems.
3812 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3813 start matching at. This allows lookbehinds to work when searching for multiple
3814 occurrences in a string.
3816 3. Added additional options to pcretest for testing multiple occurrences:
3818 /+ outputs the rest of the string that follows a match
3819 /g loops for multiple occurrences, using the new startoffset argument
3820 /G loops for multiple occurrences by passing an incremented pointer
3822 4. PCRE wasn't doing the "first character" optimization for patterns starting
3823 with \b or \B, though it was doing it for other lookbehind assertions. That is,
3824 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3825 the letter 'x'. On long subject strings, this gives a significant speed-up.
3828 Version 2.05 21-Apr-99
3829 ----------------------
3831 1. Changed the type of magic_number from int to long int so that it works
3832 properly on 16-bit systems.
3834 2. Fixed a bug which caused patterns starting with .* not to work correctly
3835 when the subject string contained newline characters. PCRE was assuming
3836 anchoring for such patterns in all cases, which is not correct because .* will
3837 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3838 DOTALL is set at top level; otherwise it knows that patterns starting with .*
3839 must be retried after every newline in the subject.
3842 Version 2.04 18-Feb-99
3843 ----------------------
3845 1. For parenthesized subpatterns with repeats whose minimum was zero, the
3846 computation of the store needed to hold the pattern was incorrect (too large).
3847 If such patterns were nested a few deep, this could multiply and become a real
3848 problem.
3850 2. Added /M option to pcretest to show the memory requirement of a specific
3851 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3853 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3854 compiled in such a way that the backtracking after subsequent failure was
3855 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3856 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3859 Version 2.03 02-Feb-99
3860 ----------------------
3862 1. Fixed typo and small mistake in man page.
3864 2. Added 4th condition (GPL supersedes if conflict) and created separate
3865 LICENCE file containing the conditions.
3867 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3868 Perl, that is the internal \ allows the delimiter to be included in the
3869 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3870 the final delimiter, add \ to the end of the pattern (to test the error).
3872 4. Added the convenience functions for extracting substrings after a successful
3873 match. Updated pcretest to make it able to test these functions.
3876 Version 2.02 14-Jan-99
3877 ----------------------
3879 1. Initialized the working variables associated with each extraction so that
3880 their saving and restoring doesn't refer to uninitialized store.
3882 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3883 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3884 fix the problem.
3886 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3887 calls, and wasn't printing the correct value for compiling calls. Increased the
3888 default value of LOOPREPEAT, and the number of significant figures in the
3889 times.
3891 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3893 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3894 a building problem on Windows NT with a FAT file system.
3897 Version 2.01 21-Oct-98
3898 ----------------------
3900 1. Changed the API for pcre_compile() to allow for the provision of a pointer
3901 to character tables built by pcre_maketables() in the current locale. If NULL
3902 is passed, the default tables are used.
3905 Version 2.00 24-Sep-98
3906 ----------------------
3908 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3909 it any more.
3911 2. Allow quantification of (?>) groups, and make it work correctly.
3913 3. The first character computation wasn't working for (?>) groups.
3915 4. Correct the implementation of \Z (it is permitted to match on the \n at the
3916 end of the subject) and add 5.005's \z, which really does match only at the
3917 very end of the subject.
3919 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3921 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3922 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3923 localized options. All options to pcre_study() were also removed.
3925 7. Add other new features from 5.005:
3927 $(?<= positive lookbehind
3928 $(?<! negative lookbehind
3929 (?imsx-imsx) added the unsetting capability
3930 such a setting is global if at outer level; local otherwise
3931 (?imsx-imsx:) non-capturing groups with option setting
3932 (?(cond)re|re) conditional pattern matching
3934 A backreference to itself in a repeated group matches the previous
3935 captured string.
3937 8. General tidying up of studying (both automatic and via "study")
3938 consequential on the addition of new assertions.
3940 9. As in 5.005, unlimited repeated groups that could match an empty substring
3941 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3942 runtime if any iteration does actually match an empty substring.
3944 10. Include the RunTest script in the distribution.
3946 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3947 discrepancies, some of which were old and were also with respect to 5.004. They
3948 have now been fixed.
3951 Version 1.09 28-Apr-98
3952 ----------------------
3954 1. A negated single character class followed by a quantifier with a minimum
3955 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3956 program crashes, or just wrong answers. This did not apply to negated classes
3957 containing more than one character, or to minima other than one.
3960 Version 1.08 27-Mar-98
3961 ----------------------
3963 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3965 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3966 latter must appear before anything that relies on it in the pattern.
3969 Version 1.07 16-Feb-98
3970 ----------------------
3972 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3973 repeat of a potentially empty string).
3976 Version 1.06 23-Jan-98
3977 ----------------------
3979 1. Added Markus Oberhumer's little patches for C++.
3981 2. Literal strings longer than 255 characters were broken.
3984 Version 1.05 23-Dec-97
3985 ----------------------
3987 1. Negated character classes containing more than one character were failing if
3988 PCRE_CASELESS was set at run time.
3991 Version 1.04 19-Dec-97
3992 ----------------------
3994 1. Corrected the man page, where some "const" qualifiers had been omitted.
3996 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3997 input syntax.
3999 3. Fixed memory leak which occurred when a regex with back references was
4000 matched with an offsets vector that wasn't big enough. The temporary memory
4001 that is used in this case wasn't being freed if the match failed.
4003 4. Tidied pcretest to ensure it frees memory that it gets.
4005 5. Temporary memory was being obtained in the case where the passed offsets
4006 vector was exactly big enough.
4008 6. Corrected definition of offsetof() from change 5 below.
4010 7. I had screwed up change 6 below and broken the rules for the use of
4011 setjmp(). Now fixed.
4014 Version 1.03 18-Dec-97
4015 ----------------------
4017 1. A erroneous regex with a missing opening parenthesis was correctly
4018 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4019 on some systems.
4021 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4022 it was reported that one broken compiler failed on the former because "code" is
4023 also an independent variable.
4025 3. The erroneous regex a[]b caused an array overrun reference.
4027 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4028 fail on data ending with that character. (It was going on too far, and checking
4029 the next character, typically a binary zero.) This was specific to the
4030 optimized code for single-character negative classes.
4032 5. Added a contributed patch from the TIN world which does the following:
4034 + Add an undef for memmove, in case the the system defines a macro for it.
4036 + Add a definition of offsetof(), in case there isn't one. (I don't know
4037 the reason behind this - offsetof() is part of the ANSI standard - but
4038 it does no harm).
4040 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4041 most of the places where whitespace preceded '#'. I have given up and
4042 allowed the remaining 2 cases to be at the margin.
4044 + Rename some variables in pcre to eliminate shadowing. This seems very
4045 pedantic, but does no harm, of course.
4047 6. Moved the call to setjmp() into its own function, to get rid of warnings
4048 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4050 7. Constructs such as \d{8,} were compiling into the equivalent of
4051 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4052 outcome, but in this particular case used more store than had been allocated,
4053 which caused the bug to be discovered because it threw up an internal error.
4055 8. The debugging code in both pcre and pcretest for outputting the compiled
4056 form of a regex was going wrong in the case of back references followed by
4057 curly-bracketed repeats.
4060 Version 1.02 12-Dec-97
4061 ----------------------
4063 1. Typos in pcre.3 and comments in the source fixed.
4065 2. Applied a contributed patch to get rid of places where it used to remove
4066 'const' from variables, and fixed some signed/unsigned and uninitialized
4067 variable warnings.
4069 3. Added the "runtest" target to Makefile.
4071 4. Set default compiler flag to -O2 rather than just -O.
4074 Version 1.01 19-Nov-97
4075 ----------------------
4077 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4078 like /([ab]*)*/, that is, for classes with more than one character in them.
4080 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4081 as /((?>a*))*/ (a PCRE_EXTRA facility).
4084 Version 1.00 18-Nov-97
4085 ----------------------
4087 1. Added compile-time macros to support systems such as SunOS4 which don't have
4088 memmove() or strerror() but have other things that can be used instead.
4090 2. Arranged that "make clean" removes the executables.
4093 Version 0.99 27-Oct-97
4094 ----------------------
4096 1. Fixed bug in code for optimizing classes with only one character. It was
4097 initializing a 32-byte map regardless, which could cause it to run off the end
4098 of the memory it had got.
4100 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4103 Version 0.98 22-Oct-97
4104 ----------------------
4106 1. Fixed bug in code for handling temporary memory usage when there are more
4107 back references than supplied space in the ovector. This could cause segfaults.
4110 Version 0.97 21-Oct-97
4111 ----------------------
4113 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4115 2. Optimized negated single characters not to use a bit map.
4117 3. Brought error texts together as macro definitions; clarified some of them;
4118 fixed one that was wrong - it said "range out of order" when it meant "invalid
4119 escape sequence".
4121 4. Changed some char * arguments to const char *.
4123 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4125 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4126 pcretest.
4129 Version 0.96 16-Oct-97
4130 ----------------------
4132 1. Added a simple "pgrep" utility to the distribution.
4134 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4135 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4136 where "ddd" means "one or more decimal digits".
4138 3. Fixed serious bug. If a pattern had a back reference, but the call to
4139 pcre_exec() didn't supply a large enough ovector to record the related
4140 identifying subpattern, the match always failed. PCRE now remembers the number
4141 of the largest back reference, and gets some temporary memory in which to save
4142 the offsets during matching if necessary, in order to ensure that
4143 backreferences always work.
4145 4. Increased the compatibility with Perl in a number of ways:
4147 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4148 to request this handling. The option can be set at compile or exec time.
4150 (b) $ matches before a terminating newline by default; an option
4151 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4152 mode). The option can be set at compile or exec time.
4154 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4155 the same as Perl's. If the decimal number it represents is less than 10
4156 or there aren't that many previous left capturing parentheses, an octal
4157 escape is read. Inside a character class, it's always an octal escape,
4158 even if it is a single digit.
4160 (d) An escaped but undefined alphabetic character is taken as a literal,
4161 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4162 escapes.
4164 (e) {0} is now permitted. (The previous item is removed from the compiled
4165 pattern).
4167 5. Changed all the names of code files so that the basic parts are no longer
4168 than 10 characters, and abolished the teeny "globals.c" file.
4170 6. Changed the handling of character classes; they are now done with a 32-byte
4171 bit map always.
4173 7. Added the -d and /D options to pcretest to make it possible to look at the
4174 internals of compilation without having to recompile pcre.
4177 Version 0.95 23-Sep-97
4178 ----------------------
4180 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4181 \x20 at the start of a run of normal characters. These were being treated as
4182 real characters, instead of the source characters being re-checked.
4185 Version 0.94 18-Sep-97
4186 ----------------------
4188 1. The functions are now thread-safe, with the caveat that the global variables
4189 containing pointers to malloc() and free() or alternative functions are the
4190 same for all threads.
4192 2. Get pcre_study() to generate a bitmap of initial characters for non-
4193 anchored patterns when this is possible, and use it if passed to pcre_exec().
4196 Version 0.93 15-Sep-97
4197 ----------------------
4199 1. /(b)|(:+)/ was computing an incorrect first character.
4201 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4202 but not actually doing anything yet.
4204 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4205 as Perl does (e.g. [-az] or [az-]).
4207 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4208 all possible positions.
4210 5. Split up into different modules to avoid including unneeded functions in a
4211 compiled binary. However, compile and exec are still in one module. The "study"
4212 function is split off.
4214 6. The character tables are now in a separate module whose source is generated
4215 by an auxiliary program - but can then be edited by hand if required. There are
4216 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4217 toupper() in the code.
4219 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4220 make them global. Abolish the function for setting them, as the caller can now
4221 set them directly.
4224 Version 0.92 11-Sep-97
4225 ----------------------
4227 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4228 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4230 2. Caseless matching was not working in character classes if the characters in
4231 the pattern were in upper case.
4233 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4235 4. Make PCRE_ANCHORED public and accept as a compile option.
4237 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4238 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4239 pass them.
4241 6. Give an error if bad option bits passed at compile or run time.
4243 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4244 pcretest to cause it to pass that flag.
4246 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4247 options, and the first character, if set.
4249 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4252 Version 0.91 10-Sep-97
4253 ----------------------
4255 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4256 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4258 2. PCRE was looping on encountering an indefinitely repeated back reference to
4259 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4260 Perl does - treats the match as successful.
4262 ****


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